CN109773770B

CN109773770B - Electric muscle composite driving mechanism for foot type robot joint

Info

Publication number: CN109773770B
Application number: CN201910175660.6A
Authority: CN
Inventors: 汪远林; 窦满峰; 王婷; 秦浩然; 张晨
Original assignee: Northwestern Polytechnical University
Current assignee: Northwestern Polytechnical University
Priority date: 2019-03-08
Filing date: 2019-03-08
Publication date: 2023-06-02
Anticipated expiration: 2039-03-08
Also published as: CN109773770A

Abstract

The invention discloses an electric muscle compound driving mechanism for a foot-type robot joint, which is used for solving the technical problem of poor practicability of the conventional foot-type robot joint driving mechanism. The technical scheme is that the tendon comprises a right tendon, a lower bracket, a left tendon, a connecting shell, a motor component and a controller. When the compound driving mechanism moves obliquely downwards from the lower support to the lower support in the horizontal process, the controller transmits a control signal to the motor assembly, so that the motor rotates anticlockwise, and meanwhile, the terminal voltage of the left tendon and the right tendon is controlled according to requirements, so that the left tendon stretches, the right tendon contracts, anticlockwise torque is given to the connecting shell and the motor assembly, and the lower support is driven to rotate anticlockwise. Similarly, when the compound driving mechanism moves from the lower bracket to the lower bracket obliquely downwards, the motor rotates clockwise, the left tendon contracts, the right tendon stretches, the connecting shell and the motor component are given clockwise torque, and the lower bracket is driven to rotate clockwise, so that the practicability is good.

Description

Electric muscle composite driving mechanism for foot type robot joint

Technical Field

The invention relates to a foot type robot joint driving mechanism, in particular to an electric muscle compound driving mechanism for a foot type robot joint.

Background

The motion characteristics of the robot with feet and the ground in discontinuous contact enable the robot with feet to adapt to complex terrains such as mountain lands, so that the robot with feet has a larger moving range than a wheeled or crawler-type mobile robot, and the joint is one of core components of the robot with feet. The bionic action characteristic of the robot with feet requires the joint driving to have the characteristics of high response speed, high torque density, light weight and the like. The motor is accurately controlled by the motor drive, and the motor drive has the characteristic of quick response, and is widely applied to the aspect of robot joint drive.

The robot joint is affected by gravity (gravitational moment) due to its own weight, and the load increases. Most robotic joints use power, heavy weight motors and reducers to provide sufficient torque for the robotic joint motion. If the gravitational moment and the part-load moment due to the weight of the robot can be compensated in some way, the torque required at the joints is reduced and the weight of the motor is reduced.

Document 1, "Multi-DOF Counterbalance Mechanism for a Service Robot Arm published in journal IEEE/ASME Transactions on Mechatronics, volume 19, 6 th edition 1756-1763," proposes the use of springs in the articulated portion of a robot to compensate for torque, reducing the impact of gravitational torque. However, the mode has poor controllability and low precision, can only perform passive compensation, and is not applicable to occasions with high requirements on moment compensation flexibility. Therefore, an intelligent torque compensation driving mechanism capable of generating enough torque while achieving accurate control, rapid response and light weight is needed.

Electroactive polymers (Electroactive Polymer, EAP) are a new type of soft smart material that can deform to a certain extent when energized to exhibit biological activity, also known as "artificial muscles". Document 2"Musclelike Joint Mechanism Driven by Dielectric Elastomer Actuator for Robotic Applications, journal Smart Materials and Structures, volume 27, 7 of 2018, describes a robotic articulation mechanism driven by EAP material. The driving structure comprises a bracket, an EAP driving assembly and a rotary joint, wherein 4 strip EAP materials are respectively arranged at the left side and the right side of the rotary joint, and 2 EAP materials are respectively arranged at each side. After the power is on, the EAP contracts or stretches to drive the joint to rotate left and right. However, the moment generated by the driving mode is limited, the nonlinear deformation accuracy is low, and the accurate force application is difficult in the occasion with high moment requirement.

Disclosure of Invention

In order to overcome the defect of poor practicability of the conventional foot-type robot joint driving mechanism, the invention provides an electric muscle compound driving mechanism for the foot-type robot joint. The mechanism comprises a right tendon, a lower bracket, a left tendon, a connecting shell, a motor component and a controller. When the compound driving mechanism moves obliquely downwards from the lower support to the lower support in the horizontal process, the controller transmits a control signal to the motor assembly, so that the motor rotates anticlockwise, and meanwhile, the terminal voltage of the left tendon and the right tendon is controlled according to requirements, so that the left tendon stretches, the right tendon contracts, anticlockwise torque is given to the connecting shell and the motor assembly, and the lower support is driven to rotate anticlockwise. Similarly, when the compound driving mechanism moves from the lower bracket to the lower bracket obliquely downwards, the motor rotates clockwise, the left tendon contracts, the right tendon stretches, the connecting shell and the motor component are given clockwise torque, and the lower bracket is driven to rotate clockwise, so that the practicability is good.

The technical scheme adopted for solving the technical problems is as follows: the electric muscle composite driving mechanism for the foot type robot joint is characterized by comprising an upper bracket 1, a tendon support frame 2, a right tendon 3, a flexible electrode and fixer 4, a lower bracket 5, a left tendon 6, a connecting shell 7, a motor component 8, a connecting frame 9, a controller 10, a connecting table 11 and a controller bracket 12.

The upper part of the upper bracket 1 is a free end, other joints are connected, and the lower part of the upper bracket 1 is fixedly connected with the tendon support frame 2. The connecting frame 9 is of an arc-shaped structure, an installation space is provided for the controller 10, the upper portion of the connecting frame 9 is connected with the tendon support frame 2, the lower portion of the connecting frame is connected with the connecting table 11, and the middle of the connecting frame is connected with the controller support 12. The controller 10 is placed on a controller stand 12.

The motor assembly 8 and the connection housing 7 constitute a motor drive assembly. The front end extension shaft of the motor component 8 is connected with the connecting table 11, one end of the lower bracket 5 is fixedly connected with the connecting shell 7, and the other end of the lower bracket 5 is a free end and is connected with other joints. When the joint moves, the connecting table 11 is fixed, the motor assembly 8 rotates to drive the connecting shell 7 to rotate, and the lower bracket 5 connected with the connecting shell 7 rotates along with the connecting shell.

The left tendon 6, the right tendon 3 and the flexible electrode form an EAP driving assembly with the fixator 4. The four groups of flexible electrodes and the fixator 4 are respectively fixed at two ends of the left tendon 6 and the right tendon 3. Two groups of 4 groups of flexible electrodes are connected with the tendon support frame 2 in the fixer to fix the left tendon 6 and the right tendon 3; the other end of the right tendon 3 is connected to the connection housing 7 via a set of flexible electrodes and the anchor 4, and the other end of the left tendon 6 is connected to the protruding connection point 13 of the anchor 4 and the connection housing 7 via a set of flexible electrodes.

The left tendon 6 and the right tendon 3 are made of EAP materials and are made by a laminating, twisting or winding method.

The beneficial effects of the invention are as follows: the mechanism comprises a right tendon, a lower bracket, a left tendon, a connecting shell, a motor component and a controller. When the compound driving mechanism moves obliquely downwards from the lower support to the lower support in the horizontal process, the controller transmits a control signal to the motor assembly, so that the motor rotates anticlockwise, and meanwhile, the terminal voltage of the left tendon and the right tendon is controlled according to requirements, so that the left tendon stretches, the right tendon contracts, anticlockwise torque is given to the connecting shell and the motor assembly, and the lower support is driven to rotate anticlockwise. Similarly, when the compound driving mechanism moves from the lower bracket to the lower bracket obliquely downwards, the motor rotates clockwise, the left tendon contracts, the right tendon stretches, the connecting shell and the motor component are given clockwise torque, and the lower bracket is driven to rotate clockwise, so that the practicability is good.

Specifically, 1. Under the premise of a certain moment demand, the output torque demand of the motor is reduced due to the moment compensation function of EAP tendons, and the problems of high torque demand, large volume and large mass of the motor and a speed reducer are solved.

And 2, the EAP tendons are placed at different force application points, and structures such as a laminated film, a twisting structure or a winding drum are adopted, so that main torque compensation is provided for the motor in multiple directions, and the flexibility of the torque compensation and the adaptive capacity of the mechanism are improved.

And 3, the electrified length of the EAP tendon is changed, and moment compensation time, direction and force are controllable. The problems of uncontrollable compensation moment and low precision are solved, and the control flexibility and the environmental adaptability of the whole joint mechanism are improved.

The invention is described in detail below with reference to the drawings and the detailed description.

Drawings

Fig. 1 is a schematic view of an electric muscle compound driving mechanism for a foot robot joint according to the present invention.

Fig. 2 is another schematic view of fig. 1.

Fig. 3 is a schematic view showing the tendon and the lower bracket when the lower bracket is inclined downward in the exercise of fig. 1.

Fig. 4 is a schematic view showing the state of tendons and a lower support when the lower support is horizontal in the exercise of fig. 1.

Fig. 5 is a top view of fig. 1.

Fig. 6 is a left side view of fig. 1.

In the figure: 1-upper bracket, 2-tendon support frame, 3-right tendon, 4-flexible electrode and fixer, 5-lower bracket, 6-left tendon, 7-connection shell, 8-motor assembly, 9-link, 10-controller, 11-connection platform, 12-controller extension board, 13-tendon tie point.

Detailed Description

The following examples refer to fig. 1-6.

The invention relates to an electric muscle compound driving mechanism for a foot robot joint, which comprises an upper bracket 1, a tendon support frame 2, a right tendon 3, a flexible electrode and fixer 4, a lower bracket 5, a left tendon 6, a connecting shell 7, a motor component 8, a connecting frame 9, a controller 10, a connecting table 11 and a controller bracket 12.

The upper part of the upper bracket 1 is a free end, other joints are connected, and the lower part of the upper bracket 1 is fixedly connected with the tendon support frame 2. The tendon support frame 2 functions to provide support for contraction exertion of tendons. The connecting frame 9 has an arc-shaped structure, so that space is provided for the internal controller 10, and the appearance is more similar to the appearance of human muscle. The upper part of the connecting frame 9 is connected with the tendon support frame 2, the lower part is connected with the connecting table 11, and the middle part is connected with the controller support frame 12. The controller 10 is placed on the controller support 12, and the controller support 12 may adopt a middle concave structure or an outer surrounding structure to further fix the controller 10.

The left tendon 6, the right tendon 3 and the flexible electrode form an EAP driving assembly with the fixator 4. The four groups of flexible electrodes and the fixator 4 are respectively fixed at two ends of the left tendon 6 and the right tendon 3. Two groups of 4 groups of flexible electrodes are connected with the tendon support frame 2 in the fixer to fix the left tendon 6 and the right tendon 3; the other end of the right tendon 3 is connected to the connection housing 7 via a set of flexible electrodes and the anchor 4, and the other end of the left tendon 6 is connected to the protruding connection point 13 of the anchor 4 and the connection housing 7 via a set of flexible electrodes. The left tendon 6 and the right tendon 3 are made of EAP materials and are made of laminated films, twisted or wound rolls and other structures.

The controller 10 is a cooperative motor and tendon controller and is disposed on a controller support 12. The controller 10 is used for controlling the movement time and the torque in the force application process according to the reference torque signal, changing the input of the controller in the motor assembly 8 and controlling the motor to rotate; and the tendon voltage is changed, the tendon length and the output torque are controlled, and the motor component 8 and the left tendon 6 or the right tendon 3 work cooperatively.

In the process that the compound driving mechanism moves obliquely downwards from the lower bracket to the lower bracket level, the controller 10 transmits a control signal to the motor component 8 to enable the motor to rotate anticlockwise, meanwhile, the terminal voltage of the left tendon 6 and the right tendon 3 is controlled according to requirements, the left tendon 6 stretches, the right tendon 3 contracts, anticlockwise torque is given to the connecting shell 7 and the motor component 8, and the lower bracket 5 is driven to rotate anticlockwise. Similarly, when the composite driving mechanism moves from the lower bracket to the lower bracket obliquely downwards, the motor rotates clockwise, the left tendon 6 contracts, the right tendon 3 stretches, the connecting shell 7 and the motor component 8 are given clockwise torque, and the lower bracket 5 is driven to rotate clockwise.

Claims

1. The utility model provides a foot formula robot joint is with compound actuating mechanism of electricity muscle which characterized in that: the tendon support comprises an upper support (1), a tendon support frame (2), a right tendon (3), a flexible electrode and fixer (4), a lower support (5), a left tendon (6), a connecting shell (7), a motor component (8), a connecting frame (9), a controller (10), a connecting table (11) and a controller support (12);

the upper part of the upper bracket (1) is a free end and is connected with other joints, and the lower part of the upper bracket (1) is fixedly connected with the tendon support frame (2); the connecting frame (9) is of an arc-shaped structure, an installation space is provided for the controller (10), the upper part of the connecting frame (9) is connected with the tendon support frame (2), the lower part of the connecting frame is connected with the connecting table (11), and the middle of the connecting frame is connected with the controller support frame (12); the controller (10) is arranged on the controller bracket (12);

the motor assembly (8) and the connecting shell (7) form a motor driving assembly; the front end extension shaft of the motor assembly (8) is connected with the connecting table (11), one end of the lower bracket (5) is fixedly connected with the connecting shell (7), and the other end of the lower bracket (5) is a free end and is connected with other joints; when the joint moves, the connecting table (11) is fixed, the motor assembly (8) rotates to drive the connecting shell (7) to rotate, and the lower bracket (5) connected with the connecting shell (7) rotates along with the connecting shell;

the left tendon (6), the right tendon (3), the flexible electrode and the fixer (4) form an EAP driving assembly; the four groups of flexible electrodes and the fixator (4) are respectively fixed at the two ends of the left tendon (6) and the right tendon (3); two groups of four groups of flexible electrodes are connected with the tendon support frame (2) in the fixer (4) to fix the left tendon (6) and the right tendon (3); the other end of the right tendon (3) is connected with the connecting shell (7) through a group of flexible electrodes and the fixer (4), the other end of the left tendon (6) is connected with the extending connection point (13) of the fixer (4) and the connecting shell (7) through a group of flexible electrodes, and the controller bracket (12) adopts a middle concave structure or an external surrounding structure.

2. The electro-muscular composite driving mechanism for a foot robot joint according to claim 1, wherein: the left tendon (6) and the right tendon (3) are made of EAP materials and are made by a laminating, twisting or winding method.