JP2004154909A - Elastic module for article gripping device and article gripping device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a module set capable of accordingly adjusting connection directivity for a gripped object and an article mechanical hand using the above module set. <P>SOLUTION: In the mechanical hand, a flexible and non-elastic bag is provided with a pressure sensor and a viscosity control means for controlling the viscosity of fluid in the bag to compose modules 5a, 5b, and 5c so as to control the liquid content in the bag, while arranging these modules 5a, 5b, and 5c in a line to form the module set 6, and then optionally/separately controlling both feeding/discharging of viscous fluid to each module 5a, 5b, 5c and viscosity of them. The module set 6 is arranged on the contact part with the gripped object 8 to change connection pressure and elasticity for each module 5a, 5b, 5c. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
[Industrial applications]
The present invention relates to an object gripping device for automatically performing operations such as assembling, disassembling, and transporting, and in particular, for gripping a wide variety of objects, a gripper that is well adapted to an object to be gripped and can be gripped softly and firmly. It is related to equipment, and performs grip force measurement and grip hand contact measurement during handling, performs assembly force measurement and disassembly force measurement during work after gripping, and can easily perform grip control, force control, positioning, etc. It is extremely effective when applied to equipment production equipment and production equipment.
[0002]
[Prior art]
Japanese Patent Application Laid-Open No. 7-328979 discloses a conventional technique relating to a gripping device which can hold various kinds of objects softly and firmly by being familiar with the object. This is a holding device that holds an object with a flexible cell in which an electrorheological fluid and an electrode section are placed inside, with the aim of realizing a holding device that holds a complex surface shape and a fragile structure softly and uniformly. A device that contacts an object without applying an electric field to the electrode part, deforms the contact surface of the cell so as to correspond to the surface shape of the object, and then applies an electric field to generate an electrorheological fluid. The viscosity of the whole or a part is increased, and the cell surface shape is substantially solidified in accordance with the surface shape of the object to be maintained to hold the object.
[0003]
This device stabilizes the above functions by incorporating a plurality of subcells (modules) inside a flexible main cell. As a result, the cell in contact with the object to be grasped can grip the object firmly in a state in which the cell is well adapted to the surface shape thereof. On the other hand, when performing work such as assembling, disassembling, and transporting various objects while holding the target object, a large uneven force acts on the holding surface. It is desirable to firmly grip or to adjust the gripping posture appropriately. For that purpose, the position of each contact portion of the cell with the gripping object and the force acting on each portion are grasped. It is necessary. However, the above prior art cannot meet this demand. For this reason, for example, in the above-mentioned subcell, it is not possible to partially control the degree of solidification of a part that is to be solidified after holding the gripped object and a part that is to be kept relatively soft so that compliance can be provided. .
[0004]
Further, there is a "gripping device" described in Japanese Patent Application Laid-Open No. 8-39474. This can grip an object of a different shape and can appropriately control the gripping force of the object. In this device, a pneumatically operated clamp cylinder is mounted on a spring via a support plate, the spring is mounted on a movable finger, and the pneumatically operated clamp cylinder is connected to the movable finger by a spring. The pneumatically operated clamp cylinder is directly fixed to the opposing fixed finger, so that the gripping force can be controlled based on the amount of expansion of the clamp cylinder and the amount of displacement of the spring to grip objects having different shapes. It is. According to the technique disclosed in Japanese Patent Application Laid-Open No. 8-39474, when an object such as assembling, disassembling, or transporting is directly applied with a force, such as assembly, disassembly, or the like, after the object is gripped, the object ( The object to be gripped) is free to move gas inside the cylinder and cannot be stably gripped. Therefore, when a force is applied to the object to be gripped, the object to be gripped is displaced in the direction of the force. (Rotation, translation, etc.). Therefore, it is not suitable for work in which a force is applied to the grasped object.
[0005]
Furthermore, there is also one described in Japanese Patent Application Laid-Open No. 2000-254884, which can lift an object whose weight and coefficient of friction are unknown by a robot hand or a manipulator without causing a shift in a gripping position. The object is gripped by a curved elastic body provided at the tip of a finger (gripping claw) of the robot hand. And this one embeds a plurality of strain gauges inside the curved elastic body, judges the fixed part and the sliding part from the strain change rate, and controls the gripping force according to the size of the fixed area and does not slide down To be lifted.
[0006]
The technique disclosed in Japanese Patent Application Laid-Open No. 2000-248884 detects slippage between an object to be gripped and a contact surface of a finger, and prevents slippage by adjusting a gripping force based on a detection signal of the slippage. However, when an external force is applied to an object during an operation such as assembly, the object cannot respond to the external force, so that the object to be gripped cannot be given optimal compliance for various operations such as assembly and disassembly. Also, in practice, it is difficult to firmly grip an object to be gripped only by sliding friction. If the gripping force is increased by a slip detection signal, as a result, the gripping force is reduced to such an extent that the object to be gripped is broken. May increase. Further, it is impossible to provide compliance with this method.
[0007]
[Patent Document 1] Japanese Patent Application Laid-Open No. 7-328979
[Patent Document 2] JP-A-8-39474
[Patent Document 2] JP-A-2000-254888
[0008]
[Problems of the prior art]
In a simple gripping device, an appropriate gripping portion is designed for each operation for each component shape in order to stably hold components and perform operations such as assembly. For example, a configuration is adopted in which the gripping contact portion is designed to have a shape that matches the shape of the component, and an elastic body such as rubber is attached so as not to damage the object to be gripped. However, it is extremely inefficient and inefficient to design gripping parts by the number of types of parts and to design gripping parts according to the work. There's a problem. Therefore, a gripping device that supports various operations of various parts is desired. Japanese Patent Application Laid-Open No. 7-328979 discloses a prior art in which the gripping surface of the object to be grasped is changed so as to conform to the surface shape of the object to be grasped.
[0009]
In the above prior art, it is possible to wrap parts of various shapes and sizes and hold them.However, when performing work such as assembly and disassembly, advanced work is required on the manipulator side. A complicated and subtle operation that can be performed is required. For example, there is a case where it is necessary to fix the component in the insertion direction as in the fitting operation, and it is desired to control the work target component so as to have compliance in the alignment direction of the fitting position. In this case, a technique for controlling the force applied to the manipulator on which the gripping device is mounted to provide compliance is required. Even if various parts are gripped on the gripping device side, the burden on the manipulator increases to cope with various operations, and problems remain in both design and development cost and development period.
[0010]
When complicated operations such as assembly and disassembly of various devices are required, not only can various types of parts fit into the surface to be gripped and are held softly and stably, On the other hand, a gripping device that can effectively control the position, posture, and the like of a gripped component is required. SUMMARY OF THE INVENTION An object of the present invention is to meet this demand, and the problems to be solved are as follows.
[0011]
[Issue 1]
A first object of the present invention is to devise a module that can appropriately change the contact pressure and elasticity of each part of the gripping device that contacts the object.
[0012]
[Assignment 2]
The problem 2 is an assembly of a plurality of modules, in which the contact pressure and elasticity can be made different for each module, and the flexibility of the contact with the object to be gripped for each of the contact portions. Is to be devised, whereby a module assembly capable of appropriately adjusting the direction of contact with the object to be grasped is devised.
[0013]
[Issue 3]
Problem 3 is that, with respect to a gripping device provided with the above-described module group, it is possible to grip by sandwiching an object or grip by enclosing the object, regardless of the shape or material of the gripped object, and stably grip the object. Another object of the present invention is to provide an arbitrary direction and an arbitrary degree of compliance in accordance with the magnitude of a force applied to an object during work and the direction of the force.
[0014]
[Measures taken to solve the problem]
[Solution 1] (corresponding to claim 1)
Solution 1 is a means for solving the above problem 1, in which a pressure sensor is provided in a flexible and non-stretchable bag, and a fluid whose viscosity changes reversibly is filled, and the viscosity of the fluid in the bag is changed. Is provided in the bag, and a module is configured so that the amount of fluid in the bag can be adjusted.
[0015]
[Action]
When the above-mentioned module is mounted on the gripping surface of the finger of the gripping device and is brought into contact with the object to be gripped, the bag that is the outer skin is flexible and non-stretchable, and the fluid inside the bag is appropriately adjusted by the adjusting means. Since the module is injected and discharged, the module is deformed in accordance with the magnitude of the contact pressure with the object to be gripped, and fits tightly to the outer surface thereof. The internal pressure at this time is detected by a pressure sensor in the bag. The magnitude of the contact pressure of each part is identified by the pressure detection signal from the pressure sensor. The viscosity of the internal fluid is controlled by the viscosity control means based on the presence or absence of the contact and the magnitude of the contact pressure. Thus, when the gripping claws are further closed and gripped with the viscosity adjusted appropriately, the contact pressure and the elasticity according to the magnitude of the viscosity of the internal fluid can be obtained.
The “cloth” described above is not necessarily limited to a cloth such as a woven cloth, but means a cloth.
[0016]
Embodiment 1 (corresponding to claim 2)
Embodiment 1 is that the bag of Solution 1 is made of urethane, silicone, Kevlar coated with a flexible material on its surface, or urethane cloth woven with fibers.
[Action]
By using silicone for the bag, it is possible to form a bag that is flexible but less stretchable, and can be flexibly deformed (conformally deformed) following the shape of the article when it comes into contact with the article. Elongation is small when force is applied to the bag. Similarly, since urethane is also flexible, it is deformed in accordance with the shape of the article, and on the other hand, when a force is applied to the bag, the elongation of the bag itself is small. Kevlar whose surface is coated with a flexible material has a similar effect, and a cloth made of urethane into which fibers are woven has a similar effect.
[0017]
Embodiment 2 (corresponding to claim 3)
Embodiment 2 is that the pressure sensor of Solution 1 is a semiconductor type, a capacitance type, or an optical type.
[Action]
By using a semiconductor type pressure sensor, the pressure can be measured with high response and high accuracy, so that the pressure inside the bag can be detected with high accuracy in real time, and the size can be reduced. Since it is possible, it can be built in the gripping device.
According to the capacitive sensor and the optical sensor, it is possible to measure with high response and high accuracy, so that the pressure inside the bag can be detected with high accuracy in real time.
[0018]
Embodiment 3 (corresponding to claim 4)
Embodiment 3 is that the fluid of Solution 1 is an electrorheological fluid (ER fluid) or a magnetic fluid.
If high responsiveness is not required for the viscosity change, a thermoplastic resin (polymer material) can be used as the fluid whose viscosity changes reversibly.
[Action]
By using an electrorheological fluid, and by using an electric field, the viscosity can be changed in a high response, and the viscosity can be changed according to the amount of the electric field. Can be controlled according to work. In addition, the magnetic fluid can change the viscosity in a high response by using a magnetic field, and it is possible to change the viscosity according to the amount of the magnetic field. Can be controlled.
[0019]
Embodiment 4 (corresponding to claim 5)
Embodiment 4 is based on the premise that the fluid in the solution 1 is an electrorheological fluid (ER fluid) or a magnetic fluid, and the viscosity control means uses an electrode for generating an electric field or a magnetic field for generating a magnetic field. It is a generating means.
[Action]
By using an electrode as a means for generating an electric field, electric charge applied to the electrode can be controlled by an inter-electrode voltage, so that control can be easily performed. Further, by using the magnetic field generating means, the amount of the magnetic field can be controlled by controlling the current flowing through a coil or the like for generating the magnetic field, so that the control can be easily performed.
When a thermoplastic resin (polymer material) is used as the fluid whose viscosity is reversibly changed, an electric heater and a cooling unit using a cooling pipe are used as the viscosity control unit.
[0020]
[Solution 2] (corresponding to claim 6)
The solution 2 is a solution to the problem 2, wherein a large number of modules of the solution 1 are arranged in parallel to form a module assembly, and the supply and discharge of the viscous fluid to each module are selectively controlled individually. The purpose is to selectively and individually control the viscosity of the fluid in the module.
[0021]
[Action]
The object to be gripped is gripped in a state where the module assembly is mounted on the gripping surface of the gripping claw of the gripping device. At this time, the supply and discharge of the fluid to each module are selectively performed individually, so that the surface of the module assembly is deformed so as to wrap the object to be grasped, and is adapted to and closely contacts the surface of the object to be grasped. At this time, the module that does not come into contact with the object to be grasped is identified by the pressure detection signal of the pressure sensor, and the abutting object, the range of the abutting object, and the magnitude of the abutting pressure of each module are identified. be able to. Therefore, the viscosity of the module in the non-contact state is reduced and hardened, and for the contacting module, the viscosity is individually selectively selected according to the position of each individual element in the contact range and the minimum contact pressure. Can be adjusted. Therefore, the degree of flexibility of the contact with the object to be grasped is controlled for each of the contact portions, whereby the contact direction with respect to the object to be grasped is appropriately adjusted.
[0022]
Embodiment 1 (corresponding to claim 7)
Embodiment 1 is that the internal fluid of the module constituting the module assembly of the solution is an electrorheological fluid, and the bag of the module is woven with electric field blocking fibers.
[Action]
In this case, the module is provided with an electrode as a viscosity control means, but since the effect of the electrode in each module on the fluid in the other bag is cut off, the viscosity of the fluid in each module is cut off. Is precisely controlled by the voltage of the individual electrodes without being affected by the electric field by the electrodes in other modules.
[0023]
[Solution 3] (corresponding to claim 8)
Solution 3 is a solution to the problem 3, in which the module assembly of the solution 2 is mounted on the gripping surface of the claw of the gripping device, and a predetermined program is executed based on the pressure detection signals of the pressure sensors of all the modules. Therefore, it is to control the viscosity control means of all the modules collectively.
[0024]
[Action]
The module assembly of Solution 2 performs the above-described operation, and the degree of flexibility of contact with the object to be gripped is controlled for each of the contact portions. Since the contact direction is appropriately adjusted, all the modules are determined based on the pressure detection signals of the pressure sensors of all the modules in accordance with a program created in advance according to the type of the object to be gripped, the type of work, and the like. The viscosity of the internal fluid is controlled, and the degree (hardness) of the viscosity is optimally adjusted. By optimizing the degree of viscosity (hardness) of each module as described above, the object to be gripped can be stably gripped according to the shape and material of the object to be gripped. Compliance according to the magnitude and direction of the force applied to the grasped object can be exhibited.
[0025]
Embodiment 1 (corresponding to claim 9)
In the first embodiment, the viscosity of each module of the module assembly is individually controlled by a CPU so that the program of the solving means 3 can achieve the compliance of the posture of the object to be grasped.
[Action]
By controlling the viscosity of each module of the module assembly, it not only grasps (adjusts) according to the shape of the article, but also acts on a predetermined part of the article in a flexible state, and in a solidified state By doing so, it is possible to maintain a gripping state according to the force applied to the article and the work.
[0026]
Embodiment 2 (corresponding to claim 10)
In a second embodiment, the CPU controls the fluid amount of each module of the module assembly individually so that the program of the solving means 3 adjusts the gripping posture of the object to be gripped to a predetermined angle.
[Action]
By individually controlling the amount of fluid in each module, there is an effect that the gripping angle of the article can be changed by changing the contact state of the article when the amount of fluid is increased, the pressure is increased, the copying amount is reduced, and the article is solidified. By reducing the amount of fluid, the gripping angle of the article can be changed in a direction opposite to the increasing direction.
[0027]
Embodiment
Embodiment 1
The bag 1a of the module 1 is a bag made of urethane cloth having a thickness of 0.2 mm, provided with a fluid supply / discharge port 1b, and further connected to a fluid supply / discharge conduit. A pressure sensor 22 and electrodes 20a and 20b are provided in the bag 1a, and the bag 1a is filled with an electrorheological fluid (ER fluid) 4. The bag 1a is deformed in accordance with the shape of the object to be gripped 2 by increasing the internal pressure of the bag 1a in a state where it is brought into contact with the object to be gripped 2 and pressed in the direction of the arrow 3, so that the shape conforms to this. Abut. At this time, since the bag 1a is non-stretchable, by supplying and discharging the fluid 4 from the fluid supply / discharge port 1b, the bag 1a is freely deformed in accordance with the pressure contact force with respect to the grasped body 2, It comes into contact with the object to be grasped 2 while being adjusted. For example, when the object to be grasped 2 moves in the direction of arrow 3 and comes into contact with the module 1 in the state shown in FIG. 1, the amount of the internal fluid 4 of the module 1 is reduced so that the object 1 comes into soft contact with the object. After the contact, the amount of the internal fluid 4 is gradually increased, and the contact is made with a desired strength to stabilize the contact with the object 2 to be grasped. When an electric field is applied between the electrodes 2a and 2b in this state, the viscosity of the internal fluid (electrorheological fluid) changes, and the object 2 can be gripped with a predetermined hardness.
[0028]
Embodiment 2
The module assembly 6 shown in FIG. 2 is a module 5 similar to the module 1 described above, which is densely arranged in a matrix. As shown in FIG. 3, when the object to be gripped 8 comes into contact with the surface of the module assembly 6 and is pressed, the module 5b of the contacted portion is entirely or partially deformed, and the module that does not contact 5a and 5c remain undeformed. The above deformation of the non-stretchable bag 1a is allowed by appropriately increasing or decreasing the amount of the electrorheological fluid of each module 5. Then, the module assembly 6 is softly (softly) abutted on the surface of the object to be gripped by the above deformation in a state where the module assembly 6 is well-adjusted, but in a stable state. Specifically, when the object to be grasped 8 moves in the contact operation direction 7 and is pressed against the matrix-like module assembly 6 as shown in FIG. 3, the contacted module 5b follows the surface shape of the object to be grasped. The modules 5a and 5c which are deformed as described above and are not in contact with the grasped object 8 do not deform. Depending on the shape of the surface of the object 8 to be gripped and the magnitude of the pressing force against the module assembly, the amount of deformation of each module also varies. By adjusting the filling pressure of the fluid, the amount of deformation is controlled to be a predetermined P [mm].
[0029]
The contact of the grasped object 8 with the module assembly 6 is in a state shown in FIG. 4, and the force Fa [N] acts in the direction of the arrow 12 (vertical direction), and the force Fb [in the direction of the arrow 13 (lateral direction). N] acts on the module part 10 so as to abut against the object to be gripped so that the deformation amount becomes P [mm] and increase the viscosity of the internal fluid of the module parts 5a and 5c, The support in the direction of arrow 13 can be firmly supported. In this case, the object to be grasped is stably supported in the direction of arrow 13 (horizontal direction), and is supported in the direction of arrow 12 (vertical direction) with compliance.
The support of the object to be gripped 8 by the module assembly 6 is not limited to the support by the claws of the gripping device. The module assembly 6 is arranged on a horizontal plane, and the object to be gripped 8 is pressed against the lateral force in a state where the object 8 is pressed against this. The same is true for the case of stable holding.
[0030]
Embodiment 3
FIG. 5 shows a gripping device in which the module assembly 6 is mounted on the gripping surface of the gripping claw 15. The gripping claws 15 are made of a relatively hard material such as a metal such as iron or aluminum, or a hardened plastic. The contact surface of the module assembly 6 has an area of 60 mm. ² Matrix of 3 mm thick, 6 mm long and 4 mm wide
They are closely arranged in a box shape. In this example as well, the fluid filled in the module is an electrorheological fluid.
The gripping claw 15 of this gripping device is driven to be opened and closed by a gripping claw moving mechanism 16, and grips the object to be gripped between the left and right module assemblies 6, 6.
In addition, a single module having the same size as the module assembly 6 may be configured, mounted on the gripping surface of the gripping claw 15, and the object to be gripped may be clamped by this. In this case, the contact state of the single module with the object to be grasped is the same as in the example shown in FIG. 1, and the mode of support (softness of support) for the vertical force and the horizontal force is different. However, by adjusting the viscosity of the internal fluid, the degree of softness of the module with respect to the object to be grasped can be appropriately adjusted in a timely manner.
[0031]
Next, a system for supplying and discharging an electrorheological fluid to and from the module bag will be described with reference to FIG.
A supply mechanism 19 composed of a supply path and a supply valve and a discharge mechanism 20 composed of a discharge path and a discharge valve are connected to the flexible and non-stretchable bag 5a, and the supply path and the discharge path are fluid tanks. 21. The supply and discharge of the fluid are performed by controlling the supply valve and the discharge valve, whereby the amount of fluid in the bag 5a is controlled.
The pressure sensor 22 incorporated at the bottom of the module 5 of the module assembly 6 is connected to a pressure sensor amplifier 24 through a cable 23 (see FIG. 7). Thereby, the internal pressure of each module in the state of being in contact with the object to be gripped is individually detected, and the magnitude of the gripping force on the object to be gripped by the gripping claws and the magnitude of the external force acting on the object to be gripped in this state. It can be detected by the force sensor 25.
[0032]
In addition, the electrodes provided in each module 5 are individually connected to the high voltage driver 26 via a cable, and the energization to the individual electrodes is individually controlled, and the voltage is controlled so that each module 5 The viscosity of the internal fluid is individually adjusted (FIG. 9). When a large number of modules are arranged to form a module assembly as in this embodiment, a conductive material such as copper or aluminum is used for the material of the module bag so that the electric field generated by the individual electrodes does not affect other modules. It has woven fine fibers.
[0033]
When the cylindrical gripping object 27 is gripped by the two gripping claws of the gripping device (FIG. 10), the module of the central contact portion 28 is deformed (FIG. 11), and a part of the gripping object 27 is wrapped. Thus, the object to be grasped is stably held. The state at this time is as shown in the sectional view of FIG.
When grasping the object to be grasped 27, firstly, the module group 32 of the grasping and contacting portion 28 is deformed as shown in FIG. The module 5x in which the end of the object to be grasped 27 and the part thereof are in contact with each other is deformed as illustrated. Of course, at this time, the fluid amount of each module of the module 5x and the module group 32 is discharged so as to allow deformation of each bag. Each module of the module 5x and the module group 32 is deformed as shown in the figure, and while the holding member is being held, the power supply to the electrodes inside each module is controlled, and the viscosity of the electrorheological fluid is adjusted to thereby adjust the viscosity. The grasped object is stably held. By increasing the viscosity of the internal fluid of each module of the module group 30 at the end that is not in contact with the object to be grasped 27 to make it most rigid, the external force acting on the object to be grasped in the lateral direction (the direction of the arrow in FIG. 12). This can be stably held against.
[0034]
Furthermore, when it is desired to stabilize the support in the gripping direction (vertical direction) by the claws, the modules of the module group 32 that are in full contact with the object to be grasped 27 and the ends of the object to be grasped 27 are in contact. The viscosity of the internal fluid of the module 5x is increased and cured. On the other hand, when it is desired to provide the grip portion with a certain degree of compliance, the fluid viscosity in the modules of the module 5x and the module group 32 is reduced. When it is desired that the partially deformed module 5x also have a stable gripping function, the internal viscosity of the module 5x is increased while the module 5x is in contact with the object to be gripped.
Further, for example, the internal fluid of each module of the non-contact module group 30 is set to a high viscosity state, the internal fluid of the module of the plane contact module group 32 is set to a low viscosity state, and the internal fluid of the partial contact module 5x is set to a high viscosity state. By doing so, the grasped object 27 is stably grasped at its root portion and is softly grasped at the distal end portion of the grasping claw, so that the compliance in the conical space, that is, the distal end portion of the grasped object 27 ( The compliance of the free part that is not gripped is realized.
[0035]
On the other hand, as shown in FIG. 13, by lowering the viscosity of the internal fluid of the module 30 which is in contact with the end of the object to be gripped and keeping it soft, the direction of the arrow, that is, When an external force in the axial direction is applied, the object to be grasped 27 can slide while squeezing the module 5a. Of course, in this case, since the internal pressure of the module 5a is controlled to be constant, a part of the internal fluid is discharged to the tank by the discharge mechanism (see the discharge mechanism 20 in FIG. 6) by the external force. Apart from the case where it is not preferable that the gripping position of the object to be gripped is deviated by an external force, the slide state is intentionally created to provide compliance in a plane parallel to the direction perpendicular to the gripping direction. be able to.
[0036]
Further, as shown in FIG. 14, the module 5e at the tip end side of the gripping claw of the module group 32 in contact with the gripped member 27 and the other modules have different viscosities of the internal electrorheological fluid. By doing so, the compliance can be changed. For example, by increasing the viscosity of the module 5e and keeping the viscosity of the other modules low, the module 5e at the front end side is centered while the end face abuts against the side face of the cured module 30. Compliance in the tilting direction can be provided.
[0037]
Further, from the state of FIG. 14, the fluid amount of each module of the module 32 is individually increased, one end of the object to be grasped 27 is pushed out, and the module is tilted with the contact point with the module 5e at the front end side as a fulcrum. And can be stably gripped. As described above, by individually adjusting the fluid amount of each module of the module group 32 in contact with the object to be grasped, the orientation of the object to be grasped once is adjusted so as to be suitable for the work at that time. Can be changed (FIG. 15). That is, based on the pressure detection signals from the pressure sensors of the individual modules in the contacting module group 32, the individual internal pressures are recognized, and the internal pressure of each module is controlled while controlling the electro- By controlling the amount of fluid and individually controlling the viscosity of the electrorheological fluid, not only can the object to be gripped stably in an appropriate posture, but also to the object to be gripped during assembly and disassembly operations. The gripping posture of the object to be gripped can be changed arbitrarily and arbitrarily in consideration of the acting external force and the work operation.
[0038]
FIG. 16 shows an example of a robot provided with a holding device using the module assembly of the present invention. This is provided with one robot arm, and is used for assembling or disassembling the product 44. This robot performs work in a predetermined procedure according to the system configuration shown in FIG.
The arm 42 of the robot 62 includes a robot servomotor 52, the gripping device 43 includes a force sensor 55 for detecting a force applied to the gripping claw, and a module (module assembly) 57 on a gripping surface of the gripping claw. The module 57 includes an internal pressure sensor 56 and a module internal electrode 58. The control box 61 further includes a fluid control valve 59 and a high-voltage driver 59.
[0039]
Further, pulse generators 46 and 47 are provided on a bus of a computer 45 of the control panel 63, and AD converters 48 and 49 and digital I / O (reference numeral 50) are further provided.
The computer 45 controls the robot servomotor 52, controls the gripping device servomotor 54 for the moving mechanism of the gripping device 43, captures the detection signals of each sensor, and performs I / O control.
A command pulse is set from the result calculated by the computer, and output from the pulse generators 46 and 47. The pulses generated from the pulse generators 46 and 47 are input to the motor amplifier 51 for the robot servomotor 52 and the motor amplifier 53 for the gripper servomotor 54, and control the robot servomotor 52 and the gripper servomotor 54, respectively. I do. The AD converter 48 provided on each bus of the computer 45 is a converter for inputting a sensor 55 provided inside the holding device mounted on the holding device 43. In addition, the detection signal of the pressure sensor 56 of the module of the gripping device is taken in. The DA converter 49 is used for a command for generating a change in the viscosity of the electrorheological fluid. When an electric field is generated in the electrode 58 in the module, the characteristics (viscosity) of the electrorheological fluid change. A high voltage driver 60 is required for generating an electric field, and a DA converter 47 is used for generating a command value for the high voltage driver 60. The digital I / O (reference numeral 50) controls ON / OFF of a fluid control valve 59 for controlling the supply and discharge of the electrorheological fluid, thereby controlling the amount of the internal fluid of the module 57 attached to the gripper. The fluid control valve and the high voltage driver are attached to the control box 61.
[0040]
Embodiment 4
The fourth embodiment is an example in which a magnetic fluid is used as the internal fluid of the module. An electromagnet is installed inside the module, the current flowing through the electromagnet is controlled, and the magnetic field is controlled. It controls the viscosity of the magnetic fluid.
As in the first to third embodiments, by controlling the supply and discharge of the fluid in the module and the viscosity of the fluid, an active shape change of the gripping contact surface is generated, and compliance of the gripped object is realized. Also, the gripping posture can be actively controlled.
[0041]
Embodiment 5
Embodiment 5 is an example in which a thermoplastic polymer material is used as the internal fluid of the module. In order to control the viscosity of the polymer material, a cooling pipe for circulating a heating wire and a cooling material is installed in the module. ing. Water, oil, liquefied nitrogen, or the like can be used as the cooling material. The polymer material in the module decreases its viscosity when heated and increases its fluidity, and when cooled, its viscosity increases and solidifies. By controlling the current flowing through the heating wire in the module and the circulation of the coolant, the temperature of the polymer material in the module is controlled, and the viscosity thereof is controlled as described above.
For example, a shape memory polymer is desirable as the polymer material. The elastic modulus changes around the glass transition point (Tg). When the glass transition point is set at 50 ° C., it is in a solidified state at 30 ° C. or lower, and its viscosity starts to largely change around 50 ° C., and changes to a flexible state at 70 ° C. or higher. An article is gripped at a temperature of Tg or more, deformed to follow, and then cooled and solidified in that shape. Since the glass transition point can be set to a low temperature, it is desirable for the polymer material of the present invention. Other suitable materials are polyurethane-based materials.
Also in the case of the fifth embodiment, as in the fourth embodiment, by controlling the supply and discharge of the fluid and the viscosity of the fluid, an active shape change of the gripping contact surface is generated, and the compliance of the gripping object is realized. It is also possible to positively control the gripping posture.
[0042]
【The invention's effect】
The effects of the present invention are summarized as follows for each main claim.
1. Effect of Claim 1
Since the force and the shape of the portion that comes into contact with the object to be grasped change freely, the module according to claim 1 abuts the object to be grasped softly and smoothly regardless of the shape of the surface to be grasped. , Can be stably gripped. Therefore, various operations can be performed while objects to be gripped having various shapes are stably gripped.
[0043]
2. Effect of Claim 2
The module according to the second aspect is made of a flexible and low-elongation cloth, so that the module can be deformed in accordance with the article to be gripped and can be stably gripped. In addition, it is possible to have compliance such as softness according to the work of the article, and it is possible to hold according to the force generated during work such as assembly and disassembly, enabling stable work and complicated Work and fitting operation can be facilitated.
[0044]
3. Effect of Claim 3
The pressure sensor according to claim 3, wherein the contact state with the object does not depend on the shape or the material of the object, and the pressure value of the contact portion of the object is obtained for each module of the contact portion, so that any value corresponding to the pressure value of each module is obtained. It is possible to efficiently grasp and hold an object having a shape of the shape for arbitrary work.
[0045]
4. Effect of Claim 4
By changing the viscosity of the internal fluid arbitrarily for each module according to electrical characteristics, a stable contact state and a contact state with compliance are created for each module, and efficient gripping operation according to any object or work It can be performed. In addition, by changing the viscosity of the internal fluid arbitrarily for each module based on magnetic characteristics, a stable contact state and a contact state with compliance are created for each module, and efficient according to any object or work A gripping operation can be performed.
[0046]
5. Effect of Claim 5
By arbitrarily controlling the viscosity of the electrorheological fluid by an electric field for each module, a contact state according to an arbitrary object or work can be created, and an efficient gripping operation according to an arbitrary object or work can be performed. . By changing the viscosity of the internal fluid arbitrarily for each module by magnetic characteristics, a stable contact state and a contact state with compliance are created for each module, and efficient gripping operation according to any object or work Can be.
[0047]
6. Effect of Claim 6
The module assembly in which a large number of the modules according to claim 1 are configured in parallel can change the force and elasticity of each module, so that the module can be softly (adjusted) according to the surface of the object to be grasped, and The contact can be stably performed, and a contact state having an arbitrary direction with respect to the object to be grasped can be realized. Therefore, the contact surface of the object to be grasped can be grasped separately in a stable portion and a compliance portion according to the work content in units of the contact portion.
[0048]
7. Effect of Claim 7
When an electric field change is generated inside each module, the fluid inside the adjacent module is not affected by the electric field change, so that each module is not affected by the adjacent one, and any contact state Can be produced.
[0049]
8. Effect of Claim 8
According to the gripping device of claim 8, the contact pressure and the elasticity of the module assembly with respect to the gripping surface of each module can be appropriately and appropriately controlled, so that the gripping object can be gripped or wrapped. Since it is possible to grip, regardless of the shape and material of the object to be gripped, it can be stably gripped, and the gripped object can be provided with any compliance according to the work. It can be exerted in any direction and at any degree, and thereby, in various operations, an object to be gripped having various shapes can be effectively gripped.
[0050]
9. Effect of Claim 9
Stable gripping irrespective of the shape and material of the object, and by using electric field control and magnetic field control to perform appropriate work force for the work to be applied to the object and compliance of the object suitable for the work, There is an effect that a contact state corresponding to the working force can be created.
[0051]
10. Effect of Claim 10
Stable gripping irrespective of the shape and material of the object, and controlling the amount of fluid in accordance with the value of the pressure sensor with the appropriate working force for the work applied to the object and the angle of the gripping posture suitable for the work Thereby, a contact state corresponding to the gripping force and the working force can be created.
[0052]
11. Effect of Claim 11
By detecting the value of the force acting on the grasped object, such as the force in the grasping direction applied when grasping the object and the force in the working direction generated during work, the object of any shape Can be efficiently gripped for an arbitrary operation in accordance with the force in the gripping direction or the force at the time of the operation.
[0053]
12. Effect of Claim 12
Stable gripping irrespective of the shape and material of the object, and by applying electric field control to the work force appropriate for the work to be applied to the object and the compliance of the object suitable for the work, the gripping force and work force can be reduced. There is an effect that a corresponding contact state can be created.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a first embodiment.
FIG. 2 is a schematic diagram of a second embodiment.
FIG. 3 is a cross-sectional view schematically illustrating a state in which a module assembly according to a second embodiment is in contact with an object to be grasped.
FIG. 4 is a cross-sectional view schematically illustrating a holding state of an object to be gripped by a module assembly according to a second embodiment.
FIG. 5 is a side view of a gripping device provided with a module assembly according to a second embodiment.
FIG. 6 is a diagram schematically showing a means for supplying and discharging an internal fluid to and from the module according to the first embodiment.
FIG. 7 is a side view schematically illustrating a relationship between an internal pressure sensor and a pressure sensor amplifier in a gripping device provided with the module assembly according to the second embodiment.
FIG. 8 is a front view of the gripping device, schematically illustrating a force sensor built in the gripping device.
FIG. 9 is a side view of a gripping device schematically illustrating a relationship between an electrode in a module and a high-voltage driver 26 in the gripping device provided with the module assembly according to the second embodiment.
FIG. 10 is a perspective view schematically illustrating a positional relationship between a gripping device provided with the module assembly according to the second embodiment and an object to be gripped.
11 is a front view schematically showing a contact area with the object to be gripped in the module assembly when the object to be gripped is gripped by the gripping device of FIG. 10;
12 is a cross-sectional view schematically illustrating an example of a contact state when an object to be gripped is gripped by the gripping device of FIG. 10;
13 is a cross-sectional view schematically illustrating another example of the contact state when an object to be gripped is gripped by the gripping device of FIG. 10;
FIG. 14 is a cross-sectional view schematically showing still another example of the contact state when the object to be gripped is gripped by the gripping device of FIG.
15 is a cross-sectional view schematically showing still another example of the contact state when the object to be gripped is gripped by the gripping device of FIG.
FIG. 16 is a perspective view schematically illustrating a working robot including a gripping device provided with a module assembly according to the second embodiment.
FIG. 17 is a block diagram showing a control system of the robot shown in FIG. 16;
[Explanation of symbols]
1,5: Module
1a: bag
1b: Fluid supply / drain
2, 8, 27: object to be grasped
6: Module assembly
15: Gripping claw
16: gripping claw moving mechanism
19: Supply mechanism
20: Discharge mechanism
21: Tank
22: Pressure sensor
23: Cable
24: Pressure sensor amplifier
25: Force sensor
26: High voltage driver
28: gripping contact part
30: Non-contact module group
32: Contact module group

Claims (16)

A pressure sensor is provided in a flexible, non-stretchable bag, a fluid whose viscosity changes reversibly is filled, and viscosity control means for adjusting the viscosity of the fluid in the bag is provided in the bag. An elastic module for an article gripping device, which is capable of adjusting the amount of fluid. The elastic module for an article gripping device according to claim 1, wherein the bag is made of urethane, silicone, Kevlar coated with a flexible material on its surface, or urethane cloth woven with fibers. The elastic module according to claim 1, wherein the pressure sensor is a semiconductor type, a capacitance type, or an optical type. The elastic module according to claim 1, wherein the fluid is an electrorheological fluid (ER fluid) or a magnetic fluid. The elastic module for an article gripping device according to claim 1 or 4, wherein the viscosity control means is an electrode for generating an electric field or a magnetic field generating means for generating a magnetic field. 2. A module assembly in which a large number of the modules according to claim 1 are arranged in parallel, the supply and discharge of a viscous fluid to each module are selectively controlled individually, and the viscosity of fluid in each module is selectively controlled individually. 7. The module assembly according to claim 6, wherein the internal fluid of the module is an electrorheological fluid, and the bag of the module is woven with electric field blocking fibers. The module assembly according to claim 6 is mounted on the gripping surfaces of the gripping claws, and the viscosity control means of all modules are collectively controlled according to a predetermined program based on pressure detection signals of pressure sensors of all modules. As described above. 9. The article gripping device according to claim 8, wherein the program controls the viscosity of each module of the module assembly individually by a CPU so that the posture of the object to be gripped is compliant with the program. 9. The article gripping device according to claim 8, wherein the program controls the fluid amount of each module of the module assembly individually by a CPU so that the program adjusts the gripping posture of the gripped object to a predetermined angle. The article gripping device according to claim 8 or 9, wherein a force detecting means is incorporated in a member attached to the gripping nail moving mechanism. The electric field or the magnetic field is controlled based on the value of the force detecting means attached to the gripping device, the pressure value inside each module by the pressure detecting means arranged in each module, and the working state of the gripping device, The gripping device according to claim 11, wherein the viscosity of each fluid is controlled. A working robot comprising the gripping device according to claim 7. A product assembled by the robot of claim 13. The module according to claim 1, wherein the fluid in the bag is a thermoplastic polymer material, and the bag contains a heating wire and a cooling pipe. The module assembly according to claim 6, wherein the module is the module according to claim 15.

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