CN110329471B - A design method of a bionic pectoral fin motion device - Google Patents

Abstract

The invention provides a design method of a bionic pectoral fin motion device, which is used for finishing the swinging and twisting motion of a bionic pectoral fin through the design of a main motor, an auxiliary motor, a main beam, a crankshaft, a fixed support and an assembly method according to the design requirement of the bionic pectoral fin motion device.

Description

A design method of a bionic pectoral fin motion device

technical field

The invention relates to the technical field of underwater bionic technology, in particular to a bionic pectoral fin motion device.

Background technique

Bionic pectoral fin propulsion is a propulsion method that imitates the movement pattern of the pectoral fins of the marine creature manta ray. It has the advantages of high propulsion efficiency, strong low-speed maneuverability, and small water disturbance. In recent years, it has been imitated by most colleges and universities and has become an underwater bionic An important development direction for advancing technology. The analysis of the motion characteristics of the pectoral fins of manta rays found that the motion of the pectoral fins is a coupled motion of two degrees of freedom, that is, when the pectoral fins move, there are both up and down flaps and fluctuations along the length of the body, and the amplitude of the fluctuations ranges from the tip of the pectoral fin to the tip of the pectoral fin. Wing roots gradually decrease. For the motion device design of this bionic motion mode, domestic and foreign colleges and enterprises mainly adopt three implementation schemes: one is to drive the flexible thin-skinned pectoral fin to flap up and down with a single degree of freedom through a main beam, and the fluctuation depends on the flexibility The interaction between the thin wall and the water flow is passively realized. The mechanism of this scheme is simple, but because the passive motion of the thin wall cannot be accurately controlled, the swimming performance of the prototype is greatly affected by the water flow environment and the material of the pectoral fin, and the environmental adaptability is poor; one is to use the pectoral fin. It is divided into several sections along the length of the body, similar to inserting several fin rays inside the pectoral fin. The flapping and wave coupling are realized by designing the single-degree-of-freedom up-and-down flapping of a single fin ray and the time difference between the flapping of the front and rear fin rays. This solution requires Design the drive mechanism and servo system of each fin ray, the mechanism design and the coordinated control system of multiple fin ray movements are complex; one is to design an integral tensioning mechanism + torsion mechanism in the form of a rope, through the reciprocating stretching at both ends of the rope Realize the up and down flapping of the pectoral fins. The motor fixed on the tensioning mechanism drives the tensioning mechanism to twist, and realizes the up and down flapping and torsional coupling motion of the bionic pectoral fins. Under this scheme, it is limited by the overall tensioning mechanism, and the up and down swing amplitude of the pectoral fins, The spanwise deformation of the pectoral fins and the amplitude of the torsion angle are greatly limited, and the overall tensioning mechanism is unavoidable for motion fatigue and response hysteresis.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the deficiencies of the prior art, and to provide a design method for a bionic pectoral fin motion device, which can solve the problem that the bionic pectoral fin flapping angle and torsion angle cannot have both precise control and simple mechanism in the device obtained by the existing design method. technical problem.

The invention provides a method for designing a bionic pectoral fin motion device, the steps are as follows:

According to the design requirements of the bionic pectoral fin motion device, the motion mode of the pectoral fin, the swing angle, the torsion angle, the motion frequency, the maximum torque of the swing drive, the maximum torque of the torsion drive, the size of the motor, the mass constraint, and the requirements for shock absorption and noise reduction, the main motor and the auxiliary motor are determined. type and size;

Ring frame design: According to the three-dimensional model of the bionic pectoral fin, n rings are designed along the spanwise direction of the bionic pectoral fin. The ring frame design includes the design of a fixed ring frame and the design of n-1 torsion ring frames. The shape of the bionic pectoral fins where the ring frame is located is the same, and the inside of the ring frame is a frame structure supported by thin plates;

Main beam design: Design the diameter and length of the main beam according to the design requirements of the bionic pectoral fins and the section characteristics along the span, and design the connection structure between the main beam and the main motor, and the connection structure between the main beam and the ring frame;

Crankshaft design: The crankshaft is a structure in which the center of the straight rod is not on the same straight line, which is composed of a cylindrical straight rod and a fixed frame. According to the design requirements of the bionic pectoral fin, the number of sections of the crankshaft, the diameter of each section and the fixed frame are designed. .

Fixed bearing design: The fixed bearing is designed according to the relative position of the main beam and the crankshaft, the diameter of the main beam and the crankshaft, and the connection method of the main beam and the crankshaft and the fixed bearing.

Assembly of the bionic pectoral fin motion device: connect one end of the main beam to the main motor, the main beam to the fixed ring frame at the root of the bionic pectoral fin, and the torsion ring frame through bearings, one end of the crankshaft is connected to the auxiliary motor, and the auxiliary motor is fixed In the fixed ring frame, the crankshaft and the torsion ring frame are connected by a sliding groove, and the main beam and the crankshaft are connected by a fixed bracket.

Further, the design of the fixing frame: the fixing frame is a flat plate, and holes are punched at suitable positions on the upper and lower sides of the flat plate to fix the crankshafts at the front and rear ends respectively, and the distance between the centers of the holes is determined by the centerline of the crankshaft here. The distance from the center line of the main beam is determined, and the thickness, shape and material selection of the fixing frame are designed to meet the strength requirements of the crankshaft torsion. The lighter the weight, the better.

Further, the number of segments of the crankshaft is determined according to the number of the torsion ring frame and the maximum torsion angle that the torsion ring frame needs to complete, and the diameter of each straight rod of the crankshaft corresponds to the maximum external force load of the ring frame position during the movement of the pectoral fins, selected The yield strength of the material, the inner space of the ring frame and the distance between the center line of the straight rod and the center line of the main beam are determined. Under the condition that the above requirements are met, the diameter should be as small as possible to reduce the weight of the structure.

Further, the design of the fixing ring frame: the shape of the fixing ring frame is determined by the shape of the bionic pectoral fin, and the connection structure of the auxiliary motor is designed inside the fixing ring frame according to the shape of the auxiliary motor, and the width of the fixing ring frame should meet the fixing of the auxiliary motor. The size of the support is required, and the ring frame should not be bent and deformed under the condition of bearing the maximum external force load during the movement of the pectoral fin.

Further, the design of the torsion ring frame: the number of the torsion ring frame is determined by the size of the bionic pectoral fin and the required motion effect, and the shape of the torsion ring frame is determined by the shape of the bionic pectoral fin where the torsion ring frame is located. It is determined that the width of the torsion ring frame should meet the fixed installation of the rolling bearing and the strength requirements of the ring frame. In the case of satisfying both, the width should be as small as possible. The torsion ring frame has a sliding groove inside, and the sliding groove The width is greater than or equal to the diameter of the crankshaft here, and the length of the sliding slot should be greater than the sum of the diameter of the circumference of the crankshaft rotating around the auxiliary motor and the diameter of the crankshaft.

According to another aspect of the present invention, a bionic pectoral fin motion device is provided, comprising a main motor, an auxiliary motor, a main beam, a crankshaft and a ring frame, the main beam is a cylindrical straight rod, and the crankshaft is made of A structure in which the center of the straight rod formed by the combination of a cylindrical straight rod and a fixing frame is not on the same straight line. The fixing frame fixes the front and rear straight rods. The purpose is to ensure that the ring frame connected to the crankshaft is driven by the crankshaft. To achieve different torsion angles, the main beam and the crankshaft are connected by a fixed support, the ring frame includes a torsion ring frame and a fixed ring frame, and the fixed ring frame is the first ring frame at the root of the bionic pectoral fin, The fixed ring frame is fixedly connected with the main beam, the torsion ring frame is the rest of the ring frame, the torsion ring frame is connected with the main beam through bearings, and is connected with the crankshaft through the sliding groove inside the torsion ring frame, and the main motor is connected with the main beam One end of the crankshaft is connected to drive the active beam and its connected ring frame, the auxiliary motor and the crankshaft to flap up and down. The auxiliary motor is connected to one end of the crankshaft to drive the crankshaft to rotate. The crankshaft slides in the torsion ring frame, and at the same time Drive the torsion ring frame to rotate around the main beam.

Further, the center line of the motor output shaft of the main motor is parallel to the spanwise section of the bionic pectoral fin, and the performance and size parameters of the main motor are designed according to the design requirements of the bionic pectoral fin.

Further, the center line of the motor output shaft of the auxiliary motor is perpendicular to the center line of the output shaft of the main motor, and the performance and size parameters of the auxiliary motor are designed according to the design requirements of the bionic pectoral fin.

Preferably, the auxiliary motor is installed on the fixed ring frame.

Preferably, the main motor and the auxiliary motor are rotary motors.

Further, the length of the main beam is determined by the length of the bionic pectoral fin, and its diameter needs to meet the requirements of the selected main beam material under the condition of the maximum external force load of the pectoral fin swing to ensure that the main beam does not bend and deform, and also needs to meet the main beam. The installation of the beam in the ring frame and the requirements for the distance between the centerline of the main beam and the centerline of the crankshaft.

Preferably, the main beam can be a cylindrical straight rod with equal diameter or a cylindrical straight rod with variable diameter.

Further, the diameter of the crankshaft needs to meet the requirements of the selected straight rod material under the condition of bearing the maximum external force load of the pectoral fin torsion to ensure that the crankshaft does not bend and deform, and also needs to meet the requirements of the installation of the crankshaft in the ring frame and the centerline of the crankshaft and the main shaft. According to the requirements for the distance between the beam center lines, the maximum and minimum distances between the center lines of different straight rods on the crankshaft and the center line of the main beam are determined according to the maximum torsion angle of the correspondingly connected torsion ring frame.

Further, the fixing frame is a flat plate, and holes are punched at suitable positions on the upper and lower sides of the flat plate to fix the crankshafts at the front and rear ends respectively, and the distance between the centers of the holes is determined by the distance between the centerline of the crankshaft and the centerline of the main beam. , The thickness, shape and material selection of the fixing frame are designed to meet the strength requirements of the crankshaft torsion, and the lighter the weight, the better.

Further, the fixed support is formed by combining two symmetrical parts, each part is two connected semi-circular grooves, the diameter of the semi-circular groove is determined by the outer diameter of the bearing at the current position, and the diameter of the two circular grooves is determined by the outer diameter of the bearing at the current position. The distance between them is determined by the distance between the main beam and the crankshaft at the current position.

Further, the width of the sliding groove is greater than or equal to the diameter of the crankshaft here, and the length of the sliding groove should be greater than the sum of the diameter of the circumference of the crankshaft rotating around the auxiliary motor and the diameter of the crankshaft.

Further, the shape of the fixed ring frame is determined by the shape of the bionic pectoral fin, and the connecting structure of the auxiliary motor is designed internally. The width of the fixed ring frame should meet the size requirements of the fixed support of the auxiliary motor, and should meet the maximum limit during the movement of the pectoral fin. Under the condition of external force load, the ring frame does not bend and deform.

Further, the number of the torsion ring frames is determined by the size of the bionic pectoral fin and the required motion effect, and the shape of the torsion ring frame is determined by the shape of the bionic pectoral fin where the torsion ring frame is located. The width of the ring frame should meet the requirements of the fixed installation of the rolling bearing and the strength of the ring frame, and the width should be as small as possible when both are met.

Applying the technical scheme of the present invention, the beneficial effects are as follows:

(1) The present invention realizes the flapping and twisting of the bionic pectoral fin by enabling the main motor to drive the main beam to realize the up and down flapping of the bionic pectoral fin, and the rotation of the bionic pectoral fin around the main beam is realized by the auxiliary motor driving the crankshaft. Coupling of two degrees of freedom, by designing the distance between the straight rod of the crankshaft and the main beam, and the sliding of the crankshaft in the torsion ring frame, to achieve the purpose of different torsion ring frames to achieve different torsion angles, and the pectoral fin flapping amplitude and The amplitude of the torsion angle can be freely designed, and the mechanism is simple;

(2) the present invention connects the main beam and the crankshaft through the fixed support, while not hindering the movement of the main beam and the crankshaft, ensuring the stability of the relative position of the main beam and the crankshaft, and helping to ensure the motion accuracy of the bionic pectoral fins;

(3) In the present invention, through the design of the sliding groove on the twisting ring frame, the twisting ring frame can follow the main beam to move up and down, and follow the crankshaft to twist around the main beam. These two movements do not interfere with each other, and can To achieve any angle of fit, and is not affected by the size of the bionic pectoral fin.

Description of drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention, constitute a part of the specification, are used to illustrate the embodiments of the invention, and together with the description, serve to explain the principles of the invention. Obviously, the drawings in the following description are only some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

Figure 1 shows a schematic diagram of a bionic pectoral fin movement device in one embodiment;

Fig. 2 shows the main beam structure diagram in one embodiment;

Fig. 3 shows a crankshaft structure diagram in one embodiment;

Figure 4 shows a block diagram of a fixed ring in one embodiment;

Figure 5 shows a structural diagram of a torsion ring in one embodiment;

Figure 6 shows a structural diagram of a fixed support in an embodiment;

Fig. 7 shows a fixed frame structure diagram;

FIG. 8 shows the flow chart of the design method of the bionic pectoral fin motion device.

Among them: 1-main motor, 2-auxiliary motor, 3-fixed ring frame, 4-torsion ring frame, 5-fixed support, 6-crankshaft, 7-sliding groove, 8-main beam, 9-bearing

Detailed ways

It should be noted that the embodiments in the present application and the features of the embodiments may be combined with each other in the case of no conflict. The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

It should be noted that the terminology used herein is for the purpose of describing specific embodiments only, and is not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly dictates otherwise, the singular is intended to include the plural as well, furthermore, it is to be understood that when the terms "comprising" and/or "including" are used in this specification, it indicates that There are features, steps, operations, devices, components and/or combinations thereof.

The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the invention unless specifically stated otherwise. Meanwhile, it should be understood that, for the convenience of description, the dimensions of various parts shown in the accompanying drawings are not drawn in an actual proportional relationship. Techniques, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the authorized description. In all examples shown and discussed herein, any specific value should be construed as illustrative only and not as limiting. Accordingly, other examples of exemplary embodiments may have different values. It should be noted that like numerals and letters refer to like items in the following figures, so once an item is defined in one figure, it does not require further discussion in subsequent figures.

The invention provides a method for designing a bionic pectoral fin motion device, the steps are as follows:

According to the design requirements of the bionic pectoral fin motion device, including the motion mode of the pectoral fin, the swing angle, the torsion angle, the motion frequency, the maximum torque of the swing drive, the maximum torque of the torsion drive, the size and quality of the motor, and the requirements for shock absorption and noise reduction, determine the main motor 1 and The type and size of the auxiliary motor 2. The design requirements of the main motor 1 mainly include the movement mode of the pectoral fin, the swing angle, the movement frequency, the maximum torque of the swing drive, the motor size and quality constraints, and the requirements for shock absorption and noise reduction. The design requirements of the auxiliary motor 2 mainly include Including pectoral fin movement mode, torsion angle, movement frequency, maximum torque of torsional drive, motor size and mass constraints, and requirements for shock absorption and noise reduction;

Ring frame design: The ring frame design includes the design of the fixed ring frame 3 and the design of the torsion ring frame 4. According to the three-dimensional model of the bionic pectoral fin, n rings are designed along the spanwise direction of the bionic pectoral fin. The equal-spaced design needs to be linearly divided along the length of the pectoral fin according to the maximum twist angle of the pectoral fin to obtain the position where the ring frame is placed and the twist angle of the ring frame at the corresponding extension. The shape of the ring frame is the same as that of the bionic pectoral fin where the ring frame is located. The inside is a frame structure supported by thin plates; the shape of the fixed ring frame 3 is determined by the shape of the bionic pectoral fin, and the connecting structure of the auxiliary motor is designed internally. The width of the fixed ring frame 3 should meet the size requirements of the fixed support of the auxiliary motor 2, and its thickness should meet Under the condition of bearing the maximum external force load during the movement of the pectoral fin, the fixed ring frame 3 does not bend and deform.

The number of torsion rings 4 is determined by the size of the bionic pectoral fin and the required motion effect. In order to ensure a smooth transition of the deformation of the bionic pectoral fin, the more the number of torsion rings 4, the better, but the more the number of torsion rings 4 will lead to structural problems. The heavier the weight of the torsion ring frame 4, usually 4 to 6 are selected. The shape of the torsion ring frame 4 is determined by the shape of the bionic pectoral fin where the torsion ring frame 4 is located. The strength requirements of 4, that is, the torsion ring frame 4 will not bend and deform under the maximum external force load during the movement of the pectoral fin, and the width should be as small as possible under the condition that both are satisfied.

Design of main beam 8: Design the diameter and length of main beam 8 according to the design requirements of the bionic pectoral fin and the cross-sectional characteristics along the span, and design the connection structure of the main beam 8 and the main motor 1, and the connection structure of the main beam 8 and the ring frame The main beam 8 is a cylindrical straight rod, and the length of the main beam 8 is determined by the length of the bionic pectoral fin, and its diameter is based on the selected main beam 8 material under the condition of the maximum external force load of the pectoral fin swing, ensuring that the main beam 8 does not produce bending The deformation is determined, and at the same time, the requirements for the installation of the main beam 8 in the ring frame and the distance between the centerline of the main beam 8 and the centerline of the crankshaft 6 must be met.

Preferably, in one embodiment, the main beam 8 can be a cylindrical straight rod with equal diameter or a cylindrical straight rod with variable diameter, and the variable diameter is suitable for the case where the thickness of each ring frame is inconsistent, in order to reduce the weight of the main beam 8 and Others in order to meet the design requirements.

Design of crankshaft 6: Crankshaft 6 is composed of cylindrical straight rods and a fixed frame. The number of segments of crankshaft 6 is determined according to the number of torsion ring frames 4 and the maximum torsion angle that needs to be completed by torsion ring frames 4. Each straight rod of crankshaft 6 The diameter is determined according to the maximum external force load corresponding to the position of the ring frame when the pectoral fin moves, the yield strength of the selected material, the internal space of the torsional ring frame and the distance between the center line of the straight rod and the center line of the main beam. Under the condition that the above requirements are met, the diameter should be as far as possible. Small, in order to reduce the weight of the structure, the fixing frame fixes the two front and rear crankshafts with 6 straight rods, and the straight rods at the front and rear ends are respectively fixed on the two ends of the fixing frame. The connection between the fixed frame and the straight rod of the crankshaft is a fixed connection, and the connection method can be a threaded connection, a pin connection, or other existing connection methods to achieve the requirements of fixed connection. The distance between the holes is determined by the distance between the crankshaft and the main beam here.

The diameter of each section of the crankshaft 6 must meet the requirements of the selected straight rod material to ensure that the crankshaft 6 does not bend and deform when the bionic pectoral fin is subjected to the maximum external force load of torsion here, and also needs to meet the requirements that the crankshaft 6 is installed in the torsion ring frame 4 and Requirements for the distance between the centerline of the crankshaft 6 and the centerline of the main beam 8. The maximum and minimum distances from the centerline of the different straight rods on the crankshaft 6 to the centerline of the main beam are determined according to the maximum torsion angle of the correspondingly connected torsion ring frame 4 .

Design of the fixed support 5: The fixed support 5 is designed according to the relative positions of the main beam 8 and the crankshaft 6, the diameters of the main beam 8 and the crankshaft 6, and the connection method of the main beam 8 and the crankshaft 6 and the fixed support 5. , the fixed support 5 is a combination of two symmetrical parts, each part is two connected semi-circular grooves, the diameter of the semi-circular groove is determined by the outer diameter of the bearing 9 at the current position, and the distance between the two circular grooves It is determined by the distance between the main beam 8 and the crankshaft 6 at the current position.

Assembly of the bionic pectoral fin motion device: connect one end of the main beam 8 with the main motor 1, the main beam 8 is fixedly connected with the fixed ring frame 3 located at the root of the bionic pectoral fin, and the torsion ring frame 4 is connected through the bearing 9, and one end of the crankshaft 6 is connected with The auxiliary motor 2 is connected, the auxiliary motor 2 is fixed in the fixed ring frame 3 , the crankshaft 6 is connected with the torsion ring frame 4 through the sliding groove 7 , and the main beam 8 and the crankshaft 6 are connected through the fixed bracket 5 .

In a specific embodiment, the design requirements of the bionic pectoral fin motion device are as follows: the bionic pectoral fin performs periodic up-and-down movement around the root and periodic torsional movement around the spanwise fixed axis at the same time, the movement frequency of the bionic pectoral fin is not greater than 0.6 Hz, The angle range is ±40°, the torsion angle range is ±45°, the torsion angle motor adopts the combination mode of direct drive and reducer, the swing driving torque of the bionic pectoral fin is not less than 40N.m, and the torsional driving torque of the bionic pectoral fin is not less than 7N.m. This requires the design of bionic pectoral fins.

According to another aspect of the present invention, the present invention provides a bionic pectoral fin motion device, comprising a main motor 1, an auxiliary motor 2, a main beam 8, a crankshaft 6 and a ring frame, the main beam 8 is a cylindrical straight rod, and the crankshaft 6 A structure in which the center of the straight rod is not in a straight line, which is composed of a cylindrical straight rod and a fixing frame. The fixing frame fixes the front and rear straight rods. The purpose is to ensure that the ring frame connected to the crankshaft can achieve different The torsion angle, the ring frame includes a torsion ring frame 4 and a fixed ring frame 3, the fixed ring frame 3 is the first ring frame close to the bionic pectoral fin, the fixed ring frame 3 is fixedly connected with the main beam 8, and the torsion ring frame 4 is the remaining ring frame Frame, the torsion ring frame 4 is connected with the main beam 8 through the bearing 9, and is connected with the crankshaft 6 through the sliding groove 7 inside the torsion ring frame 4, the main motor 1 is connected with one end of the main beam 8, and drives the main beam 8 and the connected ring. The frame, the auxiliary motor 2 and the crankshaft 6 flap up and down. The auxiliary motor 2 is connected to one end of the crankshaft 6 and drives the crankshaft 6 to rotate. The crankshaft 6 slides in the ring frame and drives the ring frame to rotate around the main beam 8 at the same time.

The center line of the motor output shaft of the main motor 1 is parallel to the spanwise section of the bionic pectoral fin. The performance of the main motor 1, including the motor type, rated power, speed, efficiency, following mode, and size parameters are based on the drive required for the bionic pectoral fin to move according to the specified oscillating motion Design the torque value range.

The auxiliary motor 2 is installed on the fixed ring frame 3. The center line of the motor output shaft of the auxiliary motor 2 is perpendicular to the center line of the output shaft of the main motor 1. The performance of the auxiliary motor includes the motor type, rated power, speed, efficiency, following mode, and size The parameters are designed according to the range of the driving torque required for the specified torsional motion of the bionic pectoral fin.

Preferably, in an embodiment, the main motor 1 and the auxiliary motor 2 are rotating electric machines.

The length of the main beam 8 is determined by the length of the bionic pectoral fin, and its diameter is determined according to the selected material of the main beam 8 to ensure that the main beam 8 does not bend and deform under the condition of bearing the maximum external force load of the bionic pectoral fin swing. 8 Requirements for installation in the ring frame and the distance between the centerline of the main beam 8 and the centerline of the crankshaft 6.

Preferably, in one embodiment, the main beam 8 can be a cylindrical straight rod with equal diameter or a cylindrical straight rod with variable diameter, and the variable diameter is suitable for the case where the thickness of each ring frame is inconsistent, in order to reduce the weight of the main beam and other conditions In order to meet the design requirements.

The fixing frame is a flat plate, and holes are punched at suitable positions on the upper and lower sides of the flat plate to fix the front and rear crankshaft straight rods respectively. The distance between the centers of the holes is determined by the distance between the centerline of the crankshaft 6 and the centerline of the main beam 8. The thickness, shape and material selection of the frame are based on the design premise of meeting the torsional strength requirements of the crankshaft 6, and the lighter the weight, the better.

The diameter of each section of the crankshaft 6 needs to meet the requirements of the selected straight rod material to ensure that the crankshaft 6 does not bend and deform under the condition of bearing the maximum external force load of the pectoral fin torsion here. Requirements for the distance between the center line and the center line of the main beam 8. The maximum and minimum distances from the centerline of the different straight rods on the crankshaft 6 to the centerline of the main beam 8 are determined according to the maximum torsion angle of the correspondingly connected torsion ring frame.

In one embodiment, the main beam 8 and the crankshaft 6 are connected by a fixed support 5, and the fixed support 5 is formed by combining two symmetrical parts, each part is two connected semicircular grooves, and the diameter of the semicircular groove is determined by The bearing outer diameter at the current position is determined, and the distance between the two circular grooves is determined by the distance between the main beam 8 and the crankshaft 6 at the current position.

In one embodiment, the width of the sliding groove 7 is greater than or equal to the diameter of the crankshaft 6 here, and the length of the sliding groove 7 is greater than the sum of the diameter of the circumference of the crankshaft rotating around the auxiliary motor 2 and the diameter of the crankshaft 6 .

The shape of the fixed ring frame 3 is determined by the shape of the bionic pectoral fin. The connection structure of the auxiliary motor 2 is designed internally. The width of the fixed ring frame 3 should meet the size requirements of the fixed support of the auxiliary motor 2, and its thickness should meet the maximum external force during the movement of the pectoral fin. Under load, the ring frame does not bend and deform.

The number of torsion rings 4 is determined by the size of the bionic pectoral fin and the required motion effect. In order to ensure the smooth transition of the bionic pectoral fin deformation, the more the number of torsion rings 4, the better, but the more the number of torsion rings 4, the higher the weight. The shape of the torsion ring frame 4 is determined by the shape of the bionic pectoral fin where the torsion ring frame 4 is located. The width of the torsion ring frame 4 should satisfy the fixed installation of the bearing 7 and the torsion ring frame. The strength requirements of 4, that is, the torsion ring frame 4 will not bend and deform under the maximum external force load during the movement of the pectoral fin, and the width should be as small as possible under the condition that both are satisfied.

In a specific embodiment, a method for designing a bionic pectoral fin motion device, as shown in Figure 8, the steps are as follows:

1. Determine the main motor 1 and the auxiliary motor 2: According to the design requirements of the bionic pectoral fin motion device, the maximum output torque of the main motor 1 is 50N.m, the size is 90mm in diameter, the length is 120mm, and the weight does not exceed 8kg. The main motor 1 adopts direct drive and Reducer combination mode, the movement of main motor 1 is the position following mode; the maximum output torque of auxiliary motor 2 is 10N.m, the size is 50mm in diameter, 60mm in length, and the weight does not exceed 4kg, the auxiliary motor 2 adopts the combination mode of direct drive and reducer , the movement of the auxiliary motor 2 is the position following mode. According to the design result of the bionic pectoral fin motion, the distance between the outer end face of the output shaft of the main motor 1 and the centerline of the output shaft of the auxiliary motor is 30mm.

2. Ring frame design: 7 ring frames are designed along the spanwise direction of the bionic pectoral fin, one of which is the fixed ring frame 3 at the root, and the rest are torsion ring frames 4, and the rings are arranged at equal intervals. The ring frame is designed as a frame structure supported by thin plates, and the thickness of the thin plate is designed according to the structural strength check. In this embodiment, the thickness of the thin plate is 2.5 mm; The length of the fixed ring frame 3 is the chord length of the corresponding pectoral fin root, which is 40 mm, the width is equal to the width of the auxiliary motor 2, and the width of the mounting support is 10 mm. The length of the torsion ring frame 4 is the chord length of the bionic pectoral fin at the corresponding position. Taking the outer end surface of the fixed ring frame 3 as the starting point, according to the length of the bionic pectoral fins and the number of ring frames, the distance between adjacent ring frames can be obtained as 60 mm, and the distance between the center of each torsion ring frame 4 and the outer end surface of the fixed ring frame 3 is determined respectively. For 105mm, 165mm, 225mm, 285mm, 345mm, 405mm, a sliding groove 7 is designed inside the torsion ring frame 4, the width of the sliding groove 7 is greater than or equal to the diameter of the crankshaft 6 here, and the length of the sliding groove 7 should be larger than the crankshaft 6 winding pair The sum of the diameter of the circumference of the motor 2 and the diameter of the crankshaft 6 .

3. Design of main beam 8: According to the number of bionic pectoral fin rings, the main beam 8 is designed to be a combination of 6 cylindrical sections with variable diameters. The diameters of the cylindrical section from the root to the end are: 16mm, 15mm, 14mm, 12.5mm, 10mm, 6mm. The length of each section is 110mm, 70mm, 70mm, 70mm, 70mm, 70mm respectively.

A flange plate is used for fixed connection between the largest diameter end of the main beam 8 and the output shaft of the main motor. The main beam 8 is rollingly connected with the fixed ring frame 3 and the torsion ring frame 4 through 7 sets of rolling bearings 9. The inner diameter of the rolling bearing 9 is the diameter of the main beam 8 at the corresponding connection position, and a positioning pin is used between the rolling bearing 9 and the ring frame along the length of the main beam. Orientation left and right.

4. Design of crankshaft 6: According to the above designed torsion ring frame 4 position, maximum torsion angle, and crankshaft rotation radius requirements, crankshaft 6 is designed to be a combination of 9-section cylinders with variable diameters and 8 fixed frames. The distance between each column and the main beam requires connection. According to the maximum hydrodynamic external force load of the crankshaft 6, the strength of each cylinder is checked, and the diameter and length of the cylinder along the spanwise direction of the bionic pectoral fin are determined as: diameter 8mm/length 11mm, diameter 10mm/length mm, diameter 8mm/length 11mm, diameter 10mm/length 40mm, 8mm/length 11mm, diameter 10mm/length 40mm, diameter 10mm/length 107mm, diameter 6mm/length 108mm, diameter 4mm/length 14mm. The dimensions of the corresponding brackets are: length 20mm width 16mm height 2mm, length 20mm width 16mm height 4mm, length 20mm width 16mm height 4mm, length 20mm width 16mm height 4mm, length 20mm width 16mm height 4mm, length 20mm width 16mm height 4mm , length 20mm width 16mm height 4mm, length 15mm width 10mm height 3mm, length 10mm width 7mm height 2.5mm.

One end with the largest end face diameter of the crankshaft 6 is inserted into the groove of the output shaft of the auxiliary motor 2 and fixed by a positioning pin. The crankshaft 6 passes through the six torsion ring frames 4 in sequence, and is slidably connected to the torsion ring frame 4 through the sliding groove 7 . The sliding groove 7 is a groove opened at a designated position in the torsion ring frame 4 , and the crankshaft 6 can slide in the sliding groove 7 to drive the torsion ring frame 4 to twist. Taking the twisting angle of the torsion ring frame 4 to 0° as the balance point for the design of the sliding groove 7, at this time the crankshaft 6 is located at the front end of the sliding groove 7, and the length of each sliding groove 7 should not be less than the crankshaft around the center line of the output shaft of the auxiliary motor 2 The sum of the diameter of the circumference during rotation and the diameter of the crankshaft 6 at the corresponding position.

5. Design of fixed support 5: The fixed support 5 is used to lock the phase position of the main beam 8 and the crankshaft 6, and the fixed connection between the main beam 8 and the crankshaft 6 is designed at the middle position of the adjacent torsion ring frame 4 along the span of the pectoral fins Support 5. The fixed support 5 is in the shape of a rectangular parallelepiped block, and is formed by two upper and lower blocks equally divided along the height direction and connected by bolts. The length of the fixed support 5 should be greater than the distance between the main beam and the crankshaft. In this example, the value is 65mm, the width is 15mm, and the thickness of the main body is 8mm. The fixed support 5 is connected with the crankshaft 6 and the main beam 8 through the rolling bearing 9. Semicircular groove, the inner diameter of the semicircular groove is the same as the outer diameter of the rolling bearing 9, and the inner diameter of the rolling bearing 9 is the same as the diameter of the main beam 8 and the straight rod of the crankshaft 6 at the corresponding position.

6. Assembly of the bionic pectoral fin motion device: connect one end of the main beam 8 with the main motor 1, the main beam 8 is fixedly connected with the fixed ring frame 3 located at the root of the bionic pectoral fin, and the torsion ring frame 4 is connected through the bearing 9, and the crankshaft 6 is connected. One end is connected with the auxiliary motor 2 , the auxiliary motor 2 is fixed in the fixed ring frame 3 , the crankshaft 6 is connected with the torsion ring frame 4 through the sliding groove 7 , and the main beam 8 and the crankshaft 6 are connected through the fixed bracket 5 .

In a specific embodiment, a bionic pectoral fin motion device, as shown in FIG. 1 , includes a main motor 1, an auxiliary motor 2, a main beam 8, a crankshaft 6 and a ring frame, there are 7 ring frames in total, including 6 torsion rings Frame 4 and a fixed ring frame 3, the fixed ring frame 3 is fixedly connected with the main beam 8, the torsion ring frame 4 is connected with the main beam 1 through the rolling bearing 9, and is connected with the crankshaft 6 through the sliding groove 7; the selected main motor 1 has a maximum output The torque is 50N.m, the diameter is 90mm, the length is 120mm, and the weight is not more than 8kg. The center line of the output shaft of the main motor 1 is parallel to the spanwise section of the pectoral fin. The auxiliary motor 2 adopts the combination mode of direct drive and reducer, and the auxiliary motor moves 2 In the position following mode, the maximum output torque of the auxiliary motor 2 is 10N.m, the size is 50mm in diameter, 60mm in length, and the weight is not more than 4kg. The auxiliary motor 2 is installed on the fixed ring frame 3, and the center line of the motor output shaft of the auxiliary motor 2 It is perpendicular to the center line of the output shaft of the main motor 1.

As shown in Figure 2, the main beam 8 is a combination of 6 cylindrical sections with variable diameters. The diameters of the cylindrical sections from the root to the end are: 16mm, 15mm, 14mm, 12.5mm, 10mm, and 6mm. The length of each section is 110mm, 70mm, 70mm, 70mm, 70mm, 70mm respectively.

As shown in FIG. 3 , the crankshaft 6 has 9 sections of cylinders with variable diameters and 8 fixing frames. As shown in FIG. 7 , it is an implementation of fixing frames. In other embodiments, other shapes and fixing frames can be used. The diameter and length of the cylinder along the spanwise direction of the pectoral fin are: diameter 8mm/length 11mm, diameter 10mm/length mm, diameter 8mm/length 11mm, diameter 10mm/length 40mm, 8mm/length 11mm, diameter 10mm/length 40mm, Diameter 10mm/length 107mm, diameter 6mm/length 108mm, diameter 4mm/length 14mm, the corresponding dimensions of the fixing frame are: length 20mm width 16mm height 2mm, length 20mm width 16mm height 4mm, length 20mm width 16mm height 4mm, length 20mm Width 16mm, height 4mm, length 20mm, width 16mm, height 4mm, length 20mm, width 16mm, height 4mm, length 20mm, width 16mm, height 4mm, length 15mm, width 10mm, height 3mm, length 10mm, width 7mm, height 2.5mm.

The main beam 8 and the crankshaft 6 are connected by two fixed supports 5 . As shown in FIG. 6 , the fixed support 5 is in the shape of a cuboid, and is formed by two upper and lower blocks equally divided in the height direction and connected by bolts. The length of the 5 blocks of the fixed support should be greater than the distance between the main beam and the crankshaft. In this example, the length of the block is 65mm, the width of the block is 15mm, and the height of the block is 8mm. Partially thickened at the rolling bearing, the height after local thickening should be greater than the corresponding The maximum value of the main beam and crankshaft diameter at the location,

The width of the sliding groove 7 is greater than or equal to the diameter of the crankshaft 6 here, and the length of the sliding groove 7 should be greater than the sum of the diameter of the circumference of the crankshaft 6 rotating around the auxiliary motor 2 and the diameter of the crankshaft 6 .

In the description of the present invention, it should be understood that the orientations indicated by orientation words such as "front, rear, top, bottom, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" etc. Or the positional relationship is usually based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and these orientation words do not indicate or imply the indicated device or element unless otherwise stated. It must have a specific orientation or be constructed and operated in a specific orientation, so it cannot be construed as a limitation on the protection scope of the present invention; the orientation words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

For ease of description, spatially relative terms, such as "on", "over", "on the surface", "above", etc., may be used herein to describe what is shown in the figures. The spatial positional relationship of one device or feature shown to other devices or features. It should be understood that spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "over" other devices or features would then be oriented "below" or "over" the other devices or features under other devices or constructions". Thus, the exemplary term "above" can encompass both an orientation of "above" and "below." The device may also be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptions used herein interpreted accordingly.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (6)

1. A design method of a bionic pectoral fin motion device is characterized by comprising the following steps: the steps are as follows,

determining the types and sizes of the main motor and the auxiliary motor according to the design requirements of the bionic pectoral fin motion device;

designing a ring frame: designing n ring frames along the spanwise direction of the bionic pectoral fin according to the three-dimensional model of the bionic pectoral fin, wherein the ring frame design comprises the design of a fixed ring frame and the design of n-1 torsion ring frames, the appearance of the ring frames is the same as that of the bionic pectoral fin at the position of the ring frames, and a frame structure supported by a thin plate is arranged inside the ring frames;

designing a main beam: according to the design requirements of the bionic pectoral fin and the section characteristics along the spanwise direction, the diameter and the length of the main beam are designed, and a connecting structure of the main beam and the main motor and a connecting structure of the main beam and the ring frame are designed;

designing a crankshaft: the crankshaft is a structure formed by combining a cylindrical straight rod and a fixing frame, wherein the center of the straight rod is not on the same straight line, and the number of sections, the diameter of each section and the fixing frame of the crankshaft are designed according to the design requirement of the bionic pectoral fin;

designing a fixed support: designing a fixed support according to the relative position of the main beam and the crankshaft which need to be fixed, the diameters of the main beam and the crankshaft and the connection mode of the main beam and the crankshaft with the fixed support;

assembling the bionic pectoral fin motion device: one end of a main beam is connected with a main motor, the main beam is fixedly connected with a fixed ring frame positioned at the root of the bionic pectoral fin and connected with a torsion ring frame through a bearing, one end of a crankshaft is connected with an auxiliary motor, the auxiliary motor is fixed in the fixed ring frame, the crankshaft is connected with the torsion ring frame through a sliding groove, and the main beam is connected with the crankshaft through a fixed support.

2. The method of claim 1, wherein the method comprises: the length of the main beam is determined by the length of the bionic pectoral fin, the diameter of the main beam is required to meet the requirements that the main beam is not bent and deformed when the selected main beam material bears the maximum external force load of pectoral fin swing, and the main beam is arranged in the ring frame and the distance between the central line of the main beam and the central line of the crankshaft is required to be met.

3. The method of claim 1, wherein the method comprises: the number of the sections of the crankshaft is determined according to the number of the torsion ring frames and the maximum torsion angle required to be finished by the torsion ring frames, the diameter of each section of the straight rod of the crankshaft is determined according to the maximum external force load of the position of the corresponding ring frame during motion of the pectoral fins, the yield strength of the selected material, the internal space of the ring frame and the distance between the central line of the straight rod and the central line of the main beam, and the diameter is required to be as small as possible under the condition that the requirements are met so as to reduce the weight.

4. The method of claim 1, wherein the method comprises: the design of mount, the mount be a flat board, punch in the suitable position on dull and stereotyped upper and lower two sides, fixed front and back both ends bent axle respectively, the distance between the hole center is confirmed from this distance that locates the bent axle central line and girder central line, the thickness, the shape and the selected material of mount use the intensity requirement that satisfies the bent axle and twist reverse as the design prerequisite, light is better more light in weight.

5. The method of claim 4, wherein the step of designing the bionic pectoral fin motion device comprises: the shape of the fixed ring frame is determined by the shape of the bionic pectoral fin, a connecting structure of the auxiliary motor is designed in the fixed ring frame according to the shape of the auxiliary motor, the width of the fixed ring frame meets the dimension requirement of the auxiliary motor for fixing and supporting, and the ring frame does not bend and deform under the condition of bearing the maximum external force load in the motion process of the pectoral fin.

6. The method of claim 4, wherein the step of designing the bionic pectoral fin motion device comprises: the number of the torsion ring frames is determined by the size of the bionic pectoral fin and the motion effect obtained by the requirement, the shape of the torsion ring frame is determined by the shape of the bionic pectoral fin where the torsion ring frame is located, the width of the torsion ring frame should meet the requirements of fixed installation of a rolling bearing and the strength of the ring frame, and the width of the torsion ring frame is as small as possible under the condition of meeting the requirements of the torsion ring frame and the bionic pectoral fin, a sliding groove is arranged in the torsion ring frame, the width of the sliding groove is more than or equal to the diameter of a crankshaft at the position, and the length of the sliding groove should be more than the sum of the diameter of the circumference of the crankshaft rotating around the.

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