CN118832622A - Multi-mode under-actuated environment self-adaptive end effector and robot - Google Patents

Abstract

The present invention discloses a multi-mode under-actuated environment-adaptive end effector and robot, comprising: a housing, an under-actuated connecting rod module, a multi-mode switching module, a linear movement module, and a two-stable energy conversion module arranged between an upper housing and a lower housing; the multi-mode switching module comprises a magnet unit, a moving unit, and a telescopic unit, the magnet unit comprises a first electromagnet and a second electromagnet, and the moving unit is arranged between the first electromagnet and the telescopic unit; the linear movement module is used to constrain the sliding module to move linearly between the first electromagnet and the second electromagnet; the under-actuated connecting rod module comprises a first under-actuated connecting rod unit and a second under-actuated connecting rod unit; the two-stable energy conversion module comprises a fixed unit and an elastic unit, the first end of the elastic unit is fixed to the housing through the fixed unit, and the second end of the elastic unit is fixedly connected to the moving unit. The present invention can convert the grasping mode, realize ultra-fast grasping of dynamic objects, and has strong stability, full functionality, and strong adaptability.

Description

A multi-mode under-actuated environment-adaptive end effector and robot

Technical Field

The present invention relates to the field of robotics technology, and in particular to a multi-mode under-actuated environment-adaptive end effector and a robot.

Background Art

In recent years, with the development of robots and related technologies, gripping devices have been increasingly applied to agriculture, service industry, biomedicine and other industries, and the design and research of gripping devices have also gradually increased. However, today's gripping devices are mainly divided into rigid gripping devices and flexible gripping devices, and are mainly based on active control. There are few studies on end effectors with multi-mode gripping control, and none of them have achieved ultra-fast gripping effects. In addition, existing gripping devices mostly focus on gripping effects.

In China, the team of Northeastern University used a traction mechanism to design an under-actuated gripper for cargo transportation and auxiliary handling. The single-motor under-actuation was achieved by using a slider rocker mechanism and rods. When grasping, each knuckle contracts in turn, which can better and more comprehensively cover the grasped object and has high flexibility. The team of Shanghai University of Engineering Science imitated the physiological morphology of bird arms and claws to design an under-actuated grasping robot arm mechanism, using springs, sliders, and slides as under-actuated auxiliary devices and quick release devices. The team of Nanjing University of Aeronautics and Astronautics designed an adaptive finger of a space end-effector, using tension springs and connecting rods to achieve the adaptive function of the finger to the object in the hand. Abroad, the University of Auckland F.M.Naser et al. used the potential energy of torsion springs and pull ropes to design an under-actuated, bi-stable ultra-fast aerial grasping and adaptive manipulator; Zhang Haijie et al. from Colorado State University used flexible mechanism design and combined with the singularity principle to design a passively triggered bi-stable adaptive grasping device, and applied it to the grasping of drones; these research results use under-actuated mechanisms to achieve adaption of grasped objects, and there are also designs that can achieve bi-stable rapid grasping, but they fail to adapt to the internal and external environments at the same time, fail to have active and passive grasping control at the same time, and fail to achieve both active control and passive triggering in the case of bi-stable rapid grasping.

The following are the structures of three existing grabbing devices in the prior art:

1. Most of the grippers currently used in the market for grasping operations adopt a screw-nut structure. The main components of the screw-nut mechanism include a screw, a screw-nut seat, a balancing system, a connecting rod device, and a control system. The screw is the rotating device of the mechanism, which is used to transmit the rotational motion of the motor; the screw-nut seat and the screw are engaged with each other through threads, converting the rotational motion of the screw into the linear motion of the screw-nut seat itself; the balancing system is a device to maintain the horizontality of the screw-nut seat, which is usually two light rods installed on both sides of the screw-nut seat; the connecting rod device is used to transmit the linear motion of the screw-nut seat to the gripper and control the opening and closing of the gripper. The control system is the core system of the mechanism.

The screw-nut mechanism is usually used for active opening and closing control of the clamping jaws. For example, when it is necessary to clamp an object, the motor of the control system rotates counterclockwise, causing the screw-nut seat to move backward, driving the connecting rod fixed axis to rotate, and closing the clamping jaws. When it is necessary to release the object, the motor of the control system rotates clockwise, causing the screw-nut seat to move forward, driving the connecting rod fixed axis to move in the opposite direction, and opening the clamping jaws. The clamping jaws of this device can only perform active grasping control, and the control is relatively complex.

But this structure has the following disadvantages:

1. Since the structure of the screw nut seat determines that the screw must be fixedly connected to the motor, and the screw nut seat must be stably engaged with the screw through the thread, this type of device can only be actively controlled.

2. The threaded engagement between the screw and the screw nut seat causes a lot of noise when it moves.

3. The control speed of this mechanism is determined by the pitch of the screw rod, which results in a slow opening and closing speed of the clamping jaws.

It is not possible to quickly grasp or grasp moving objects.

Second, the adaptive fingers and adaptive grippers currently available on the market are mostly designed with flexible materials, and by increasing the number of joints of the fingers or grippers, the fingers or grippers can almost completely wrap the grasped object to achieve adaptive grasping. This type of grasping device is widely used in working conditions such as grasping flexible objects and picking in orchards, and can effectively ensure the integrity of the grasped object.

But this structure has the following disadvantages:

1. This design increases the number of joints so that the fingers or grippers use different shapes to grasp objects, resulting in a lower load and inability to grasp heavier objects.

2. This design is only adaptive to the grasped object, and cannot adapt to the external environment with obstacles, that is, it cannot effectively grasp in an obstructed environment.

3. The two-stable fast trigger device mainly utilizes the deformation of flexible and rigid materials. By deforming the material, the deformation energy of the material itself is maintained at a critical point and a stable state. When a force greater than a certain value is provided externally, the critical point will be broken and the current stable state will be destroyed, so that the energy stored in the material itself is fully released and the material suddenly changes to another stable state without deformation. This technology is used in daily life such as mousetraps, tape measures, hairpins, etc., and the use of this device in the gripper can achieve ultra-fast grasping of objects.

But this structure has the following disadvantages:

1. A bi-stable device using a passive trigger design will immediately activate the transition from one steady state to another as long as the external force exceeds the trigger value, and cannot adapt to the external environment.

2. This bi-stable trigger device cannot regulate the trigger force. When it is necessary to grasp a relatively large object, it may be triggered by a small interfering object.

3. For a bi-stable device designed using material deformation, the speed of its steady-state change is closely related to the material itself used, and after the design is completed, it cannot be modified according to actual working conditions.

Therefore, the grasping device in the prior art cannot grasp the target object quickly and with high stability at the same time.

Summary of the invention

The purpose of the present invention is to solve the problem that a grasping device can grasp a target object quickly and with strong stability at the same time, and to provide a multi-mode under-actuated environment-adaptive end effector and a robot.

To achieve the above object, the present invention adopts the following technical solutions:

A multi-mode under-actuated environment-adaptive end effector, comprising:

A housing, the housing comprising an upper housing and a lower housing, wherein the underactuated link module, the multi-mode switching module, the linear movement module, and the bi-stable energy conversion module are disposed between the upper housing and the lower housing;

The multi-mode switching module includes a magnet unit, a moving unit, and a telescopic unit. The telescopic unit is fixed on the housing and includes a cylinder body and a cylinder plunger. The cylinder plunger can be telescopic relative to the cylinder body. The magnet unit includes a first electromagnet and a second electromagnet. The first electromagnet is fixed on the housing. The moving unit is arranged between the first electromagnet and the telescopic unit. The second electromagnet is fixedly installed at the front end of the cylinder plunger. The moving unit is installed with a first magnetic object on a side relative to the first electromagnet and with a second magnetic object on a side relative to the second electromagnet.

The multi-linear moving module is used to constrain the sliding module to move linearly between the first electromagnet and the second electromagnet, and the linear moving module includes a first sliding connection unit fixed to the housing, and the moving unit is provided with a second sliding connection unit that can be slidably connected to the first sliding connection unit;

The underactuated link module comprises a first underactuated link unit and a second underactuated link unit, and the underactuated link module is used to grasp a target object by bringing the first end of the first underactuated link unit and the first end of the second underactuated link unit closer together, the second end of the first underactuated link unit and the second end of the second underactuated link unit are connected to the moving unit, and the first end of the first underactuated link unit and the first end of the second underactuated link unit are controlled to move away from and approach each other by moving forward and backward of the moving unit;

The bi-stable energy conversion module includes a fixed unit and an elastic unit, wherein the first end of the elastic unit is fixed to the housing through the fixed unit, and the second end of the elastic unit is fixedly connected to the mobile unit. The elastic unit is used to provide energy for bi-stable changes. When the first end of the first under-actuated link unit and the first end of the second under-actuated link unit are far away from each other, the elastic unit can be stretched, and when the first end of the first under-actuated link unit and the first end of the second under-actuated link unit are close to each other, the elastic unit can convert its own elastic potential energy into kinetic energy.

In some embodiments, the second electromagnet includes a first electromagnet block and a second electromagnet block, the telescopic unit includes two cylinder plungers, and the first electromagnet block and the second electromagnet block are installed on the front ends of the two cylinder plungers through studs.

In some embodiments, the first sliding connection unit includes a first linear bearing seat and a second linear bearing seat, both of which are fixedly arranged on the housing, a first linear bearing is installed on the first linear bearing seat, and a second linear bearing is installed on the second linear bearing seat, and a first optical rod and a second optical rod are fixedly arranged on the moving unit, the first optical rod is passed through the first linear bearing, and the second optical rod is passed through the second linear bearing.

In some embodiments, two ball plungers are respectively disposed on the upper surface and the lower surface of the mobile unit. The balls of the four ball plungers are in rolling contact with the housing, so as to limit the freedom of movement of the mobile unit in the up and down directions.

In some embodiments, the first under-actuated link unit and the second under-actuated link unit both include: a fingertip for clamping a target object, first to fifth connecting parts, the first end of the third connecting part is fixedly connected to the fingertip, the second end of the third connecting part is pivotally connected to the first end of the second connecting part and the first end of the fourth connecting part in sequence, the second end of the second connecting part is pivotally connected to the first end of the first connecting part, and a torsion spring is arranged between the second end of the second connecting part and the first end of the first connecting part, the second end of the fourth connecting part is pivotally connected to the first end of the fifth connecting part, a tension spring is arranged between the fourth connecting part and the fifth connecting part, when the opening and closing angles of the fourth connecting part and the fifth connecting part change, the tension spring is deformed accordingly, and the second end of the first connecting part and the second end of the fifth connecting part are pivotally connected to the moving unit from the inside to the outside in sequence.

In some embodiments, the fifth connecting part is two triangular plates arranged in parallel, the first corner of the fifth connecting part is pivotally connected to the second end of the fourth connecting part, the second corner of the fifth connecting part is pivotally connected to the moving unit, the third corner of the fifth connecting part and the first connecting rod are provided with external threaded bearings, at least one of the upper shell and the lower shell is provided with a through groove, and the external threaded bearing is slidably arranged on the through groove.

In some embodiments, a trigger membrane is fixedly connected between the second connection portion of the first under-actuated link unit and the second connection portion of the second under-actuated link unit, and the trigger membrane is used to transmit a trigger force provided by the outside.

In some embodiments, the upper shell and the lower shell are connected with mortise and tenon structures through mortise and tenon parts, and vertical plate connectors are fixedly arranged at the connection between the mortise and tenon parts and the upper shell and the lower shell, and the two connected surfaces of the vertical plate connectors respectively abut the mortise and tenon parts and the upper shell or the lower shell.

In some embodiments, an end connection module is also included, and the end connection module includes a first end connection member, a second end connection member, and a third end connection member. The first end connection member is used to connect the mortise and tenon members of the end, and the end is an end away from the under-actuated connecting rod module. The third end connection member is used to connect the target robot arm. The second end connection member is arranged between the first end connection member and the third end connection member, and is a connecting plate for the first end connection member and the third end connection member. The first end connection member is provided with a boss, and the second end connection member is provided with a through hole. The boss can be matched and connected with the through hole to disperse the shear force on the screw to the boss.

The present invention also provides a robot, comprising the above-mentioned multi-mode under-actuated environment-adaptive end effector.

The present invention has the following beneficial effects:

The present invention realizes modular connection through the design of a multi-mode switching module, a linear movement module, an under-actuated connecting rod module, and a bi-stable energy conversion module. The simplicity of the connection improves the stability of the structure. The multi-mode switching module can switch between an active control grasping mode and an active bi-stable control mode through the arrangement of a first electromagnet, a second electromagnet, and a moving unit, and replaces motor grasping with pneumatic grasping, and has the characteristics of fast grasping speed and low noise. The present invention can realize ultra-fast grasping of dynamic objects with strong stability, and the overall design has full functionality, wide applicability, and strong adaptability.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a perspective schematic diagram of a multi-mode under-actuated environment-adaptive end effector according to an embodiment of the present invention;

FIG2 is a perspective schematic diagram of a multi-mode under-actuated environmentally adaptive end effector without an upper shell in an embodiment of the present invention;

FIG3 is a schematic structural diagram of an underactuated connecting rod module in an embodiment of the present invention;

FIG4 is a schematic diagram of the structure of a fingertip in an embodiment of the present invention;

5 is a schematic structural diagram of a first connecting rod in an embodiment of the present invention;

6 is a schematic diagram of the structure of a multi-mode switching module according to an embodiment of the present invention;

7 is a schematic diagram of the structure of some units of a multi-mode switching module according to an embodiment of the present invention;

FIG8 is a schematic diagram of an open state of a multi-mode under-actuated environment-adaptive end effector according to an embodiment of the present invention;

9 is a schematic diagram of a closed state of a multi-mode under-actuated environment-adaptive end effector according to an embodiment of the present invention;

10 is a schematic structural diagram of a multi-mode under-actuated environmentally adaptive end effector equipped with a trigger membrane in an embodiment of the present invention;

11 is a schematic structural diagram of a linear motion module in an embodiment of the present invention;

FIG12 is a schematic diagram of the structure of a bi-stable energy conversion module in an embodiment of the present invention;

13 is a schematic diagram of the structure of the housing in an embodiment of the present invention;

14 is a schematic diagram of the structure of the terminal connection module in an embodiment of the present invention;

The following are the descriptions of the reference numerals:

DETAILED DESCRIPTION

The following is a detailed description of the embodiments of the present invention. It should be emphasized that the following description is only exemplary and is not intended to limit the scope and application of the present invention.

It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element. In addition, connection can be used for fixing as well as for coupling or communication.

It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

When grasping moving objects, the use of a two-stable fast-trigger grasping method can greatly improve the grasping success rate of moving objects; when it is necessary to quickly grasp static objects, the use of a two-stable fast-trigger grasping method can also greatly reduce the grasping time, and the use of active control grasping can greatly improve the grasping success rate and stability. With the development of time, robots will fully enter the fields of service, medical care, military, etc., and their working objects and environments will continue to change. Improving the work efficiency of robots will be more valued by people. Therefore, the technology of grasping devices with multiple working modes will have extremely broad development prospects in the future, and even directly promote the progress and development of human society.

Therefore, it is of great research value and practical significance to develop a multifunctional grasping device that has active grasping mode, actively triggered bi-stable grasping, passively triggered bi-stable grasping, and can adapt to both external and internal environments at the same time.

The first purpose of the embodiment of the present invention is to enable the gripper to effectively grasp the target object in an environment with obstacles, and to provide an under-actuated connecting rod gripper design scheme, which can achieve adaptive grasping in an environment with external obstacles and grasping objects.

The second purpose of the embodiment of the present invention is to enable the gripper to adapt to different working conditions. A design scheme is provided that combines three modes: active control grasping, active triggered bi-stable grasping, and passive triggered bi-stable grasping. It can be used to meet work requirements such as the need for stable grasping, the need to quickly grasp static objects, and the need to quickly grasp dynamic objects.

1-2 , the multi-mode under-actuated environment-adaptive end effector of the embodiment of the present invention comprises: a housing 1, the housing 1 comprises an upper housing 11 and a lower housing 12, an under-actuated link module 2, a multi-mode switching module 3, a linear movement module 4, and a bi-stable energy conversion module 5 are arranged between the upper housing 11 and the lower housing 12;

The multi-mode switching module 3 includes a magnet unit, a moving unit 33, and a telescopic unit. The telescopic unit is fixed on the housing 1 and includes a cylinder body 311 and a cylinder plunger 312. The cylinder plunger 312 can be telescopic relative to the cylinder body 311. The magnet unit includes a first electromagnet 321 and a second electromagnet 322. The first electromagnet 321 is fixed on the housing 1. The moving unit 33 is arranged between the first electromagnet 321 and the telescopic unit. The second electromagnet 322 is fixedly installed at the front end of the cylinder plunger 312. The moving unit 33 is installed with a first magnetic object on a side relative to the first electromagnet 321 and with a second magnetic object on a side relative to the second electromagnet 322.

The linear moving module 4 is used to constrain the sliding module to move linearly between the first electromagnet 321 and the second electromagnet 322. The linear moving module 4 includes a first sliding connection unit fixed to the housing 1, and a second sliding connection unit capable of slidingly connecting with the first sliding connection unit is provided on the moving unit;

An underactuated link module 2, the underactuated link module 2 comprises a first underactuated link unit 201 and a second underactuated link unit 202, the underactuated link module 2 is used to grasp a target object by bringing the first end of the first underactuated link unit 201 and the first end of the second underactuated link unit 202 closer together, the second end of the first underactuated link unit 201 and the second end of the second underactuated link unit 202 are connected to a moving unit 33, and the first end of the first underactuated link unit 201 and the first end of the second underactuated link unit 202 are controlled to move away from and approach each other by moving the moving unit 33 forward and backward;

The bistable energy conversion module 5 includes a fixed unit and an elastic unit. The first end of the elastic unit is fixed to the housing 1 through the fixed unit, and the second end of the elastic unit is fixedly connected to the mobile unit. The elastic unit is used to provide energy for bistable changes. When the first end of the first under-actuated link unit 201 and the first end of the second under-actuated link unit 202 are far apart, the elastic unit can be stretched. When the first end of the first under-actuated link unit 201 and the first end of the second under-actuated link unit 202 are close to each other, the elastic unit can convert its own elastic potential energy into kinetic energy.

An embodiment of the present invention further provides a robot, including the above-mentioned multi-mode under-actuated environment-adaptive end effector. An embodiment of the present invention further provides a corresponding grasping method, which is implemented based on the above-mentioned end effector.

This embodiment aims to solve the following problems:

The external environment of the end effector used to grasp the object and the adaptive problem of grasping the target object;

The problem of switching between multiple grasping modes of the end effector used to grasp objects;

The fast grasping problem of the end effector used to grasp objects;

Problems of programmable bi-stable trigger force and adjustable steady-state switching speed for end effectors used to grasp objects;

The problem of miniaturization of the overall structural design of the end effector used to grasp objects;

Specifically, the multi-mode under-actuated environmentally adaptive end effector and robot in this embodiment include a shell 1, an under-actuated connecting rod module 2, a multi-mode switching module 3, a linear motion module 4, a bi-stable energy conversion module 5 and an end connection module 6. Specifically, the under-actuated connecting rod module 2 is arranged on the inner side of the shell 1 in a left-right symmetrical manner, the multi-mode switching module 3 is arranged at the rear end of the under-actuated connecting rod module 2, the linear motion module 4 is arranged on the upper, lower, left and right sides of the multi-mode switching module 3 in a left-right symmetrical arrangement, the bi-stable energy conversion module 5 is arranged on the left and right sides of the linear motion module 4, and the end connection module 6 is arranged on the rear side of the multi-mode switching module 3.

In some embodiments, the opening and closing angle range of the first underactuated link unit 201 or the second underactuated link unit 202 on one side is 0-45 degrees, and the total opening and closing angle is 0-90 degrees. However, due to the setting of the underactuated link unit, the two fingertips 25 are always kept in a parallel state, and the angle between the two fingertips 25 and the ground is always 90 degrees and will not change unless it encounters external force and needs to be self-adapted. The limitation of the opening and closing range within this range can adapt to most of the current situations of human hand grasping, and has good versatility in the case of small size. In this embodiment, the opening and closing range of the entire end effector fingertip 25 is limited to 0-140mm. The shaft connection between each link in the underactuated link module 2 needs to be provided with a plane bearing 292 and a deep groove ball bearing 294 to ensure the low friction and smoothness of the rotation of each link. The multi-mode switching module 3 is used to switch the three modes of active control grasping, active triggering two-stable grasping, and passive triggering two-stable grasping, and the working stability of each mode must be guaranteed. The linear moving module 4 is used to maintain the balance of the moving block in the multi-mode switching module 3 relative to the upper and lower surfaces and the left and right planes, and to ensure that the moving block can only move in a straight line direction. Therefore, it is necessary to adopt a design scheme that can maintain linear motion and ensure its low-friction lubricity; the two-state energy conversion module 5 needs to ensure that the rates of change of the two steady states can be changed according to needs after the design is completed, and it is convenient to adjust, so a simple replacement design is adopted; the outer shell 1 needs to maintain the stability of the internal objects of the end effector, and needs to guide the movement trajectory of the connecting rod. The outer shell 1 needs to use high-strength materials in the design, and hollow out a track for guiding the under-driven connecting rod module 2; the end connection module 6 is used to connect the robotic arm, and a modular design that is easy to replace is required.

The multi-mode under-actuated environmentally adaptive end effector should be miniaturized and tightly integrated, that is, multiple functions can be realized by the same component. For example, the core maintaining components of the three modes of active control grasping, active triggered bi-stable grasping, and passive triggered bi-stable grasping are set to two electromagnets, so as to minimize the total space used, minimize the number of parts, reduce the overall quality of the mechanism, and improve the degree of integration of the mechanism.

Underactuated connecting rod design:

The underactuated connecting rod design can achieve passive adaptation to the external environment and the grasped object, which reduces the demand for the external environment when grasping objects and improves the success rate of grasping objects in various complex environments. Therefore, in order to solve the problem of easy failure in grasping objects in complex environments, the end effector adopts an underactuated connecting rod design, using tension spring 26 and torsion spring 293 to maintain the underactuated working state of the two connecting rods, greatly improving the passive adaptability to the grasping environment and grasping objects.

In general, the two jaws of a fully-driven connecting rod gripper can only move along a fixed trajectory, and will not be able to grasp objects that are close to a step or placed in a narrow gap. However, the under-driven connecting rod design adopted in the embodiment of the present invention can enable the two jaws to move along different trajectories according to different grasping environments, passively adapting to the grasping environment. It is far superior to the fully-driven connecting rod gripper on the basis of miniaturization, and greatly improves the success rate of grasping.

Multi-mode crawling integrated design solution:

The multi-mode grasping integrated design scheme includes three modes: active control grasping, active triggering bi-stable grasping, and passive triggering bi-stable grasping. If you need to grasp the object stably and the grasping rate is not high, you can use the active control grasping mode; if you need to grasp a static object very quickly, you can use the active triggering bi-stable grasping mode, and use steady-state transition for fast grasping; if you need to grasp a moving object, you can use the passive triggering bi-stable mode. As long as the moving object touches the grasping membrane, the present invention will perform steady-state transformation and close quickly to complete the grasping task. The integration of these three modes makes the present invention suitable for more grasping needs, and its versatility is much higher than that of a gripper with only one mode. In addition, while integrating the three modes, the present invention also maintains the compactness and miniaturization of the device.

In this embodiment, the underactuated connecting rod module 2, the multi-mode switching module 3, the linear movement module 4, and the bi-stable energy conversion module 5 are arranged between the upper housing 11 and the lower housing 12. The structures of the modules corresponding to the various schemes are as follows:

3-5, the underactuated link module 2 includes a first underactuated link unit 201 and a second underactuated link unit 202. The underactuated link module 2 is used to grasp the target object by bringing the first end of the first underactuated link unit 201 and the first end of the second underactuated link unit 202 closer together. The second end of the first underactuated link unit 201 and the second end of the second underactuated link unit 202 are connected to the moving unit 33. The first end of the first underactuated link unit 201 and the first end of the second underactuated link unit 202 are controlled to move away from and approach each other by moving the moving unit 33 forward and backward. The first underactuated link unit 201 and the second underactuated link unit 202 are symmetrically arranged. Each under-actuated connecting rod device includes: first to fifth connecting parts, a tension spring fixed column 28, a triangular plate 27, an external threaded bearing 291, a plane bearing 292, a tension spring 26, a fingertip 25 for clamping a target object, and a silicone mold 251. The first to fifth connecting parts in this embodiment are the first connecting rod 21, the second connecting rod 22, the third connecting rod 23, the fourth connecting rod 24, and two triangular plates 27 arranged in parallel. The first end of the third connecting rod 23 is fixedly connected to the fingertip 25, and the fingertip 25 is fixed to the third connecting rod 23 by threads. The silicone mold 251 is fixed to the front of the fingertip 25 by bonding. The second end of the third connecting rod 23 is pivotally connected to the first end of the second connecting rod 22 and the The first end of the fourth link 24 and the second end of the second link 22 are hingedly connected to the first end of the first link 21, and a torsion spring 293 is arranged between the second end of the second link 22 and the first end of the first link 21, the second end of the fourth link 24 is hingedly connected to the first end of the two triangular plates 27, a tension spring 26 is arranged between the fourth link 24 and the two triangular plates 27, and a tension spring fixing column 28 is connected to the two triangular plates 27 by threads and is arranged in the middle of the two triangular plates 27. When the opening and closing angles of the fourth link 24 and the two triangular plates 27 change, the tension spring 26 is deformed accordingly, and the second end of the first link 21 and the second end of the two triangular plates 27 are deformed from the inside to the outside according to the second end of the first link 21 and the second end of the two triangular plates 27. The first corner of the two triangular plates 27 is pivotally connected to the second end of the fourth connecting part (the fourth connecting rod 24 is connected to the leftmost connecting hole of the two triangular plates 27 through a hinge shaft), the second corner of the fifth connecting part is pivotally connected to the moving unit 33, the third corner of the two triangular plates 27 and the first connecting rod 21 are provided with external threaded bearings 291 (the external threaded bearings 291 are fixed to the bottommost circular holes of the two triangular plates 27 and the front and back centers of the first connecting rod 21 through threads), at least one of the upper shell 11 and the lower shell 12 is provided with a through groove, and the external threaded bearings 291 are slidably arranged on the through groove. In this embodiment, the upper shell 11 and the lower shell 12 are both provided with through grooves. The arrangement form of all connecting rod rotating shafts is plane bearing 292-deep groove ball bearing 294-deep groove ball bearing 294-plane bearing 292, and only the second end of the first connecting rod 21, that is, the lower rotating shaft, has a torsion spring 293 embedded outside the deep groove ball bearing 294.

As described above, this under-actuated connecting rod design uses tension spring 26 and torsion spring 293 to maintain the under-actuated working state. The tension spring 26 and torsion spring 293 have the characteristics of being deformed by external force and reset after being free of external force. This corresponds to the deformation of the tension spring 26 and torsion spring 293 to achieve adaptation when encountering an obstructing environment or contacting with the grasping object. After leaving the obstructing environment and completing the grasping, the tension spring 26 and torsion spring 293 are reset to maintain the stability of the gripping of the clamp. In addition, a plane bearing 292 and a deep groove ball bearing 294 are used at the rotating shaft connecting each two connecting rods, which greatly reduces the friction of the connecting rod movement and makes the relative movement of the connecting rod smoother. When the connecting rod is not subjected to external force as a whole, it is set to a quadrilateral state, the first connecting rod 21 and the second connecting rod 22 are parallel and have stability, and when subjected to external force, the first connecting rod 21 and the second connecting rod 22 will rotate relative to each other, forming an angle, which is a pentagonal state, to balance the forces received inside and outside. This design enables the underactuated connecting rod device to passively adapt when receiving vertical and horizontal forces, which is beneficial to the grasping work. The external threaded bearing 291 fixed on the triangular plate 27 is used to contact the through groove 19 (hollow track) on the housing 1 to guide the movement trajectory of the underactuated connecting rod.

Referring to Figures 6 and 7, the multi-mode switching module 3 includes a magnet unit, a moving unit 33, and a telescopic unit. The telescopic unit is fixed on the housing 1 and includes a cylinder body 311 and a cylinder plunger 312. The cylinder plunger 312 can be telescopic relative to the cylinder body 311. The magnet unit includes a first electromagnet 321 and a second electromagnet 322. The first electromagnet 321 is sleeved with a front electromagnet mounting member 36 and is fixed to the housing 1. The moving unit 33 is arranged between the first electromagnet 321 and the telescopic unit. The second electromagnet 322 is fixedly mounted at the front end of the cylinder plunger 312. The moving unit 33 is mounted with a first magnetic object on one side relative to the first electromagnet 321 and a second magnetic object on the other side relative to the second electromagnet. A second magnetic object is installed on one side of 322. In this embodiment, the first magnetic object is the first iron sheet 341, and the second magnetic object is the second iron sheet 342; the second electromagnet 322 includes a first electromagnet block 3221 and a second electromagnet block 3222, and the telescopic unit includes two cylinder plungers 312. The first electromagnet block 3221 and the second electromagnet block 3222, the rear electromagnet mounting component 35, and the special head stud 313 are all rear electromagnet assembly parts. The first electromagnet block 3221 and the second electromagnet block 3222 are installed on the front end of the two cylinder plungers 312 through the special head stud 313, and are covered with the rear electromagnet mounting component 35, wherein the special head stud 313 is an M3-M5 special head stud.

As shown in the figure, the first iron sheet 341 and the second iron sheet 342 are installed on the front and rear sides of the mobile unit 33, the first electromagnet 321 is installed on the front side of the first iron sheet 341, and the rear electromagnet assembly is installed on the two cylinder plungers 312 of the cylinder, wherein the installation method is: the push plate originally installed on the cylinder plunger 312 is disassembled, and the first electromagnet block 3221 and the second electromagnet block 3222 are connected to the cylinder plunger 312 through the different head stud 313 (M3-M5 different head stud). This design transforms and utilizes the cylinder, so that the push rod of the cylinder has adjustable magnetic force, and connects two different threaded holes through the different head stud 313, which greatly saves installation space and assembly parts, and is more in line with the design concept of miniaturization.

The working mode of the multi-mode switching module 3 is as follows:

① When using the active control grasping mode, the first electromagnet block 3221 and the second electromagnet block 3222 of the rear electromagnet assembly are continuously energized, so that the first electromagnet block 3221 and the second electromagnet block 3222 are kept in an adsorption state with the second iron sheet 342 fixed on the mobile unit 33, and then the air flow rate output by the air pump is controlled, and the forward or reverse movement of the cylinder is controlled by the solenoid valve, so as to realize active grasping with controllable speed. The pneumatic method is used to replace the motor control of the traditional gripper to realize active grasping, which has the characteristics of simple and convenient control, and compared with the control method of the screw nut, the pneumatic drive has the advantages of smaller noise and faster movement control speed.

② When the active bistable control mode is used, the power to the rear electromagnet assembly is cut off, making the first electromagnet block 3221 and the second electromagnet block 3222 non-magnetic. Since the bistable energy conversion module 5 continuously provides force for the mobile unit 33 to move toward the rear side, when not subjected to other forces, the mobile unit 33 will remain at the rearmost side and tightly attached to the rear electromagnet assembly, that is, the clamp remains in a closed state. When using this mode, first the cylinder plunger 312 moves forward and pushes forward, pushing the moving block to the front end and fitting with the first electromagnet 321. At this time, the first electromagnet 321 is energized, adsorbing the first iron sheet 341 fixed on the moving block, so that the moving unit 33 is fixed at the front end due to the magnetic force, and the clamping jaws remain in the maximum open state. When the object is to be grasped, the first electromagnet 321 is powered off. Due to the loss of magnetic force, under the action of the force to the rear side continuously provided by the two-stable energy conversion module 5, the steady state of the clamping jaw opening (refer to Figure 8) is quickly transformed into the steady state of the clamping jaw closing (refer to Figure 9), completing the fast grasping task of the two-stable state. This design can actively control the triggering timing of the two-stable state transition, and the two-stable grasping design can complete the grasping task in a very short time, with the characteristics of ultra-high-speed grasping.

③ When using the passive bistable control mode, a trigger membrane 37 needs to be fixedly installed on the second connecting rod 22 of the two side clamps (the first underactuated connecting rod unit 201 and the second underactuated connecting rod unit 202). Referring to FIG10 , in this embodiment, it is arranged in the middle of the inner side of the two second connecting rods. The material used for the trigger membrane 37 is made of 5-degree transparent silicone, which has soft performance to absorb the impact force of the grasped object and is used to transmit the trigger force provided by the outside world. The use of this mode is similar to the active bistable control mode. The moving block is pushed to the front end by the cylinder so that the first electromagnet 321 and the first iron sheet 341 remain in the adsorption state. When the force is transmitted to the trigger membrane 37, the trigger membrane 37 transmits this force to the moving block. As long as this force breaks through the adsorption force of the first electromagnet 321, the moving block will break away from the adsorption effect of the first electromagnet 321, and the clamp will be quickly closed under the action of the bistable energy conversion device to complete the bistable grasping. Furthermore, the user can adjust the magnetic force of the first electromagnet 321 by adjusting the voltage input to the first electromagnet 321, thereby changing the trigger force required to trigger the passive bi-stable grasping, and realizing programmable trigger force and adjustable trigger sensitivity. Compared with the fixed trigger force of the existing bi-stable device, this design can better adapt to various grasping requirements, reduce the interference of some small mass objects that are not what we need to grasp, and effectively reduce the possibility of false triggering.

Referring to Figure 11, the linear moving module 4 is used to constrain the sliding module to move linearly between the first electromagnet 321 and the second electromagnet 322. The linear moving module 4 includes a first sliding connection unit fixed on the housing 1, and the moving unit 33 is provided with a second sliding connection unit that can be slidably connected to the first sliding connection unit. Specifically, in this embodiment, the first sliding connection unit includes a first linear bearing seat 41 and a second linear bearing seat (the same as the first linear bearing seat 41 in this embodiment, respectively arranged on both sides of the moving unit 33), both of which are fixedly arranged on the housing 1, a first linear bearing 42 is installed on the first linear bearing seat 41, and a second linear bearing (the same as the first linear bearing 42 in this embodiment) is installed on the second linear bearing seat, and a first light rod 43 and a second light rod (the same as the first light rod 43 in this embodiment) are fixedly arranged on the moving unit 33, the first light rod 43 is penetrated through the first linear bearing 42, and the second light rod is penetrated through the second linear bearing, and the first light rod 43 and the second light rod are respectively fixed to the moving unit 33 through the light rod flange 44. Each linear bearing seat is provided with a first linear bearing retaining ring 45 and a second linear bearing retaining ring 46 at the front and rear. The first linear bearing seat 41 and the second linear bearing seat are fixedly connected to the housing 1, and the polished rod flange 44 is fixedly connected to the mobile unit 33, and is symmetrically arranged on the left and right. Two ball plungers 47 are respectively arranged on the upper surface and the lower surface of the mobile unit 33, and are symmetrically arranged on the left, right, top and bottom.

The design of this module uses the cooperation of the left-right symmetrical linear bearing and the light rod to limit the freedom of movement of the moving block in the left-right direction, and uses the rolling contact between the balls of the four ball plungers 47 and the housing 1 to limit the freedom of movement of the moving block in the up-down direction, ensuring that when the multi-mode switching device is working, the moving unit 33 can accurately maintain the set position for linear motion. Most of the designs on the market that limit linear movement use linear guides, but the linear guides include a slider and a slide rail, and the overall volume is large, which is not suitable for use in the present invention. The linear moving module 4 in the embodiment of the present invention is equivalent to splitting the freedom of the linear guide, and then combining it with the parts that must be used, which greatly reduces the space required for installation and can ensure the same use effect.

Referring to FIG. 12 , the two-stable energy conversion module 5 includes a fixed unit and an elastic unit. The first end of the elastic unit is fixed to the housing 1 through the fixed unit, and the second end of the elastic unit is fixedly connected to the mobile unit 33. The elastic unit is used to provide energy for two-stable changes. When the first end of the first under-actuated connecting rod unit 201 and the first end of the second under-actuated connecting rod unit 202 are far away, the elastic unit can be stretched. When the first end of the first under-actuated connecting rod unit 201 and the first end of the second under-actuated connecting rod unit 202 are close together, their own elastic potential energy can be converted into kinetic energy. In this embodiment, the fixed unit in this embodiment includes a rear end rubber tube fixing member 53, a stainless steel column 52, a first rubber tube stopper 54, and a second rubber tube stopper 55, and the elastic unit is a rubber tube 51. In this module, the rubber tube 51 is used to provide energy for bi-stable changes, that is, to convert its own elastic potential energy into kinetic energy. The rear end rubber tube fixing piece 53 is fixedly connected to the housing 1 through the stainless steel column 52, so that the rear end position of the rubber tube 51 is fixed. The front end of the rubber tube 51 is connected to the moving unit 33. Under the action of the linear moving module 4, the energy provided by the rubber tube 51 can only make the moving unit 33 move along the linear direction to realize the opening and closing of the clamping jaws. The first rubber tube limit block 54 and the second rubber tube limit block 55 are used to limit the fixed position of the rubber tube 51 to prevent the rubber tube 51 from falling off during operation.

When the user needs to adjust the sensitivity and reaction speed of the jaws in the bi-stable working mode, that is, to adjust the rate required for the jaws to open and close, the length of the rubber tube 51 can be directly replaced, or the number of rubber tubes 51 can be added or reduced, so that the elastic potential energy stored in the jaws when they are in the open state is changed, thereby simply completing the adjustment of the rate required for the two stable state transitions. Compared with the existing bi-stable gripping device that cannot adjust the rate, this design is simpler, more user-friendly and more universal.

Referring to FIG13 , the housing 1 includes an upper housing 11 and a lower housing 12, which are connected by mortise and tenon joints in a mortise and tenon structure, and vertical plate joints 15 are fixedly arranged at the joints between the mortise and tenon joints and the upper housing 11 and the lower housing 12, respectively, and the two connected surfaces of the vertical plate joints 15 respectively abut against the mortise and tenon joints and the upper housing 11 or the lower housing 12. Specifically, in the present embodiment, the housing 1 includes a back connecting plate 13, an upper housing 11, a back mortise and tenon joint 14, a vertical plate joint 15, a side mortise and tenon joint 16, a lower housing 12, an elliptical vertical plate joint 18, and a front mortise and tenon joint 17. The upper shell 11 and the lower shell 12 are made of aluminum alloy and have sufficient strength as the external support of the clamp, and the back mortise and tenon parts 14, the side mortise and tenon parts 16 and the front end mortise and tenon parts 17 are processed by carbon fiber plates. The mortise and tenon parts and the upper shell 11 and the lower shell 12 are connected by the mortise and tenon structure and the vertical plate connection parts 15 and the elliptical vertical plate connection parts 18. The front end mortise and tenon part 17 is connected to the shell 11 and the lower shell 12 through the mortise and tenon structure, and then the elliptical vertical plate connection part 18 is connected to the front end mortise and tenon plate, the upper shell 11 and the lower shell 12 through the back and the upper end surface by screws, completing double fixation, so that the whole has higher strength and reliability, and can withstand greater impact force.

The front end of the upper shell 11 and the lower shell 12 are hollowed out to reveal the moving area of the external threaded bearing 291 on the moving block in the multi-mode switching device. According to the calculation that the moving trajectory of the two external threaded bearings 291 on one side when the clamp is working is an elliptical trajectory, the trajectory for guiding the movement of the external threaded bearing 291 is designed using the cam principle and the elliptical trajectory, and the part between the two trajectories is also completely hollowed out to accommodate the irregular movement of the external threaded bearing 291 caused by the external force of the under-actuated connecting rod device. In addition, the upper shell 11 and the lower shell 12 are designed with a lightweight hollow design as a whole, which is convenient for observing the working status of the internal components and the maintenance of the internal components. This design applies the cam principle deformation to the outer shell 1, thereby guiding the movement path of the under-actuated connecting rod device, which is highly innovative and practical.

Referring to Figure 14, the end connection module 6 includes a first end connection member 61, a second end connection member 62, and a third end connection member 63. The first end connection member 61 is used to connect the mortise and tenon parts at the end, and the end is the end away from the under-actuated connecting rod module 2. The third end connection member 63 is used to connect the target robot arm. The second end connection member 62 is arranged between the first end connection member 61 and the third end connection member 63, and is a transfer plate for the first end connection member 61 and the third end connection member 63. There is a boss between the first end connection member 61 and the second end connection member 62 to disperse the shear force on the screw to the boss. Specifically, the first terminal connector 61 is provided with a boss, and the second terminal connector 62 is provided with a through hole, and the boss can be connected with the through hole, and the boss on the first terminal connector 61 is inserted into the large circular hole (i.e., through hole) in the center of the second terminal connector 62, and the boss side of the first terminal connector 61 has four threaded blind holes, and the second terminal connector 62 has a light hole, and the screw is inserted from the side of the second terminal connector 62 and screwed into the threaded blind hole on the side of the boss of the first terminal connector 61 for connection; there is no boss connection between the second terminal connector 62 and the third terminal connector 63, but four M5 screws are used. These four M5 screws are screwed directly from the surface of the second terminal connector 62 and screwed into the threaded holes on the surface of the third terminal connector; if there is no boss connection, all shear forces are borne by the fixed screws, and when there is a boss connection now, the boss of the first terminal connector 61 inserted into the second terminal connector 62 also plays a role in bearing the shear force, which is equivalent to the shear force being borne by the boss and the screws instead of being borne by the screws alone.

In this embodiment, the three end connectors are fixed by threads, wherein the first end connector 61 is connected to the back connecting plate 13 in the housing 1, the third end connector 63 is connected to the mechanical arm, and the second end connector 62 is a transition plate of the two parts. This design simplifies the connection between the end effector and the mechanical arm, and each end connector is matched with a boss, which disperses the shear force on the screw to the boss, reduces the possibility of screw breakage, and improves stability and reliability. In addition, the connection method between the second end connector 62 and the first end connector 61 is set as a side thread. Compared with the thread set on the front, this side thread design is more convenient for users' daily disassembly.

The embodiments of the present invention have the following beneficial effects compared with the prior art:

The end effector of the embodiment of the present invention is designed with a shell 1, an under-actuated connecting rod module 2, a multi-mode switching module 3, a linear movement module 4, a bi-stable energy conversion module 5 and an end connection module 6. It can be combined with a robotic arm to complete the grasping task, and complete active and passive ultra-fast grasping in an environment with obstacles, and can also achieve ultra-fast grasping of dynamic objects. The overall design is fully functional, widely applicable and highly adaptable.

In the end effector of the embodiment of the present invention, a multi-mode switching module 3 composed of an electromagnet, a cylinder, and a rubber tube 51 has the ability to conveniently switch between three working modes, and different rubber tubes 51 can be replaced according to demand to quickly adjust the gripping speed of the gripper. The sensitivity of the two-stable state gripping can also be infinitely adjusted by adjusting the voltage of the electromagnet, and has good quick-change characteristics and programmable characteristics.

In the end effector of the embodiment of the present invention, pneumatic grasping is used instead of motor grasping, which has the characteristics of fast grasping speed and low noise.

In the end effector of the embodiment of the present invention, the characteristics of the linear guide rail are separated, and a linear motion device composed of a linear bearing and a ball plunger 47 is designed, which has good linear motion guiding ability and miniaturization characteristics.

In the end effector of the embodiment of the present invention, a relatively lightweight housing 1 is designed, which utilizes the cam principle in a deformed manner, and guides the movement of the under-actuated connecting rod device with a hollow track, and adopts carbon fiber plates, aluminum alloys and other materials to ensure its strength.

In the end effector of the embodiment of the present invention, a simplified end connection module 6 is designed to connect the robot arm and the end effector, and has quick disassembly capability.

Key technical points of the embodiments of the present invention:

1. The multi-mode under-actuated environmentally adaptive end effector is divided into a shell 1, an under-actuated connecting rod module 2, a multi-mode switching module 3, a linear movement module 4, a bi-stable energy conversion module 5 and an end connection module 6, which can be connected in a modular manner, and the simplicity of the connection improves the stability of the structure.

2. An underactuated link module 2 is designed to enable the gripper to adapt to the external environment and internal grasped objects.

3. A multi-mode switching module 3 is designed which can switch between three modes: active control grasping, active triggered bi-stable grasping, and passive triggered bi-stable grasping.

4. A miniaturized linear motion module 4 is designed to greatly save installation space.

5. A module that can realize programmable bi-stable trigger force by adjusting the output voltage to the electromagnet is designed, and a bi-stable energy conversion module that can realize quick change and autonomous adjustment of bi-stable grasping rate is designed. 5.

6. A relatively lightweight housing 1 is designed, and the cam principle is deformed and applied. The hollow track guides the movement of the under-actuated connecting rod module 2, and carbon fiber plates, aluminum alloys and other materials are used to ensure its strength.

7. A connector is designed to simplify the connection between the robot arm and the end effector, and it has quick-disassembly function.

The above content is a further detailed description of the present invention in combination with specific/preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, without departing from the concept of the present invention, it can also make several substitutions or modifications to these described embodiments, and these substitutions or modifications should be regarded as belonging to the protection scope of the present invention. In the description of this specification, the description of the reference terms "an embodiment", "some embodiments", "preferred embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily target the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In the absence of mutual contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions and modifications can be made herein without departing from the scope of protection of the patent application.

Claims (10)

1. A multi-mode underactuated environment-adaptive end effector, comprising:

The shell comprises an upper shell and a lower shell, and the under-actuated connecting rod module, the multi-mode switching module, the linear movement module and the two-stable energy conversion module are arranged between the upper shell and the lower shell;

The multi-mode switching module comprises a magnet unit, a moving unit and a telescopic unit, wherein the telescopic unit is fixed on the shell and comprises a cylinder body and a cylinder plunger, the cylinder plunger can stretch and retract relative to the cylinder body, the magnet unit comprises a first electromagnet and a second electromagnet, the first electromagnet is fixed on the shell, the moving unit is arranged between the first electromagnet and the telescopic unit, the second electromagnet is fixedly arranged at the front end of the cylinder plunger, a first magnetic substance is arranged on one side of the moving unit, opposite to the first electromagnet, and a second magnetic substance is arranged on one side, opposite to the second electromagnet, of the moving unit;

The linear movement module is used for restraining the sliding module from moving linearly between the first electromagnet and the second electromagnet, the linear movement module comprises a first sliding connection unit fixed on the shell, and a second sliding connection unit capable of being connected with the first sliding connection unit in a sliding manner is arranged on the movement unit;

The under-actuated connecting rod module comprises a first under-actuated connecting rod unit and a second under-actuated connecting rod unit, the under-actuated connecting rod module is used for grabbing a target object through the approaching of the first end of the first under-actuated connecting rod unit and the first end of the second under-actuated connecting rod unit, the second end of the first under-actuated connecting rod unit and the second end of the second under-actuated connecting rod unit are connected with the moving unit, and the moving unit is used for controlling the first end of the first under-actuated connecting rod unit and the first end of the second under-actuated connecting rod unit to be far away from and approaching;

The two-stable energy conversion module comprises a fixing unit and an elastic unit, wherein the first end of the elastic unit is fixed on the shell through the fixing unit, the second end of the elastic unit is fixedly connected with the moving unit, the elastic unit is used for providing two-stable-state variable energy, when the first end of the first under-actuated connecting rod unit and the first end of the second under-actuated connecting rod unit are far away, the elastic unit can be lengthened, and when the first end of the first under-actuated connecting rod unit and the first end of the second under-actuated connecting rod unit are close, the elastic potential energy of the elastic unit can be converted into kinetic energy.

2. The multi-mode underactuated environment-adaptive end effector as recited in claim 1, wherein the second electromagnet comprises a first electromagnet block and a second electromagnet block, the telescoping unit comprises two cylinder plungers, and the first electromagnet block and the second electromagnet block are mounted at front ends of the two cylinder plungers by studs.

3. The multi-mode underactuated environment adaptive end effector as recited in claim 1, wherein said first sliding connection unit comprises a first linear bearing seat and a second linear bearing seat, both of which are fixedly disposed on said housing, said first linear bearing seat is provided with a first linear bearing, said second linear bearing seat is provided with a second linear bearing, said moving unit is fixedly provided with a first polish rod and a second polish rod, said first polish rod is disposed on said first linear bearing in a penetrating manner, and said second polish rod is disposed on said second linear bearing in a penetrating manner.

4. The multi-mode underactuated environment-adaptive end effector as recited in claim 1, wherein two ball plungers are provided on an upper surface and a lower surface of the moving unit, respectively, and a degree of freedom of movement of the moving unit in an up-down direction can be restricted by rolling contact of balls of the four ball plungers with the housing.

5. The multi-mode under-actuated environment-adaptive end effector of claim 1, wherein the first under-actuated linkage unit and the second under-actuated linkage unit each comprise: the device comprises a fingertip, first to fifth connecting parts used for clamping a target object, wherein the first end of a third connecting part is fixedly connected with the fingertip, the second end of the third connecting part is sequentially and pivotally connected with the first end of a second connecting part and the first end of a fourth connecting part, the second end of the second connecting part is pivotally connected with the first end of the first connecting part, a torsion spring is arranged between the second end of the second connecting part and the first end of the first connecting part, the second end of the fourth connecting part is pivotally connected with the first end of the fifth connecting part, a tension spring is arranged between the fourth connecting part and the fifth connecting part, when the opening and closing angle of the fourth connecting part and the opening and closing angle of the fifth connecting part are changed, the tension spring correspondingly deforms, and the second end of the first connecting part and the second end of the fifth connecting part are sequentially and pivotally connected with the moving unit from inside to outside.

6. The multi-mode underactuated environment adaptive end effector as claimed in claim 5, wherein the fifth connecting portion is two triangular plates arranged in parallel, a first corner of the fifth connecting portion is pivotally connected to a second end of the fourth connecting portion, a second corner of the fifth connecting portion is pivotally connected to the moving unit, external screw bearings are disposed on a third corner of the fifth connecting portion and the first connecting rod, at least one of the upper housing and the lower housing is provided with a through slot, and the external screw bearings are slidably disposed on the through slot.

7. The multi-mode under-actuated environment-adaptive end effector as claimed in claim 1, wherein a trigger membrane is fixedly connected between the second connection portion of the first under-actuated linkage unit and the second connection portion of the second under-actuated linkage unit, and the trigger membrane is used for transmitting an externally provided trigger force.

8. The multi-mode underactuated environment adaptive end effector as claimed in claim 1, wherein said upper and lower housings are connected in a mortise and tenon structure by mortise and tenon joint members, and vertical plate joint members are fixedly provided at the joints of said mortise and tenon joint members with said upper and lower housings, respectively, and two surfaces connected to each other of said vertical plate joint members are abutted to said mortise and tenon joint members and said upper or lower housing, respectively.

9. The multi-mode underactuated environment-adaptive end effector as recited in claim 8, further comprising an end connection module comprising a first end connection for connecting a mortise and tenon of an end, a second end connection for connecting an end remote from the underactuated link module, a third end connection for connecting a target mechanical arm, an adapter plate disposed between the first end connection and the third end connection for the first end connection and the third end connection, and a boss disposed on the first end connection, the second end connection being provided with a through hole capable of being cooperatively connected with the through hole to disperse shear forces borne by a screw onto the boss.

10. A robot comprising a multi-mode underactuated environment-adaptive end effector according to any of claims 1-9.