Control system for assisting lower limb exoskeleton robot

Abstract

The invention discloses a control system of a power-assisted lower limb exoskeleton robot, which comprises an angle sensor, a potentiometer module, a microcontroller, a motor driving module and a joint motor module, and is characterized in that the joint motor module comprises a robot left hip joint motor and a robot right hip joint motor; the potentiometer module comprises a left potentiometer and a right potentiometer. Movement of the left hip joint motor and the right hip joint motor of the robot is controlled through left and right swing angle signals of the waist of the wearer, the joint motors adopt a torque mode to achieve active assistance on the hip joints of the lower limbs of the wearer, and the robot has the advantages of being simple in structure, easy to achieve and wear and high in reliability and is suitable for mountain climbing, load-bearing walking and the like.

Description

Technical Field

[0001] The invention relates to a control system of an exoskeleton robot, and in particular to a control system of an exoskeleton robot for assisting lower limbs. Background Art

[0002] An exoskeleton robot is a typical exoskeleton power-assist device that can provide power, support, protection and other functions for the wearer. It integrates robot technologies such as human motion intention acquisition, multi-motor motion control, and bionic mechanical design. It is a typical human-machine integrated system that can be used in medical, transportation, and military fields. The power-assisted lower limb exoskeleton robot is a type of exoskeleton robot, which is mainly used to provide motion assistance and assist walking for wearers with lower limb weakness.

[0003] The power-assisted lower limb exoskeleton robot is different from the load-bearing power-assisted exoskeleton person, because the wearers of the load-bearing exoskeleton robot are all normal people. The robot moves with the person, only sharing the power of the load-bearing part, and does not provide power for the human body's own movement. Therefore, the commonly used follow-up control algorithm for load-bearing exoskeleton robots is not suitable for the control system of the power-assisted exoskeleton robot. The user of the power-assisted exoskeleton robot is a person with movement disabilities (for example, when climbing a mountain, the legs cannot move normally), and the lower limbs cannot complete the normal movement posture. Standard movement posture data needs to be used for correction. The control method is generally an active control strategy. According to the different input signals, the control system of the power-assisted exoskeleton robot can generally be divided into three types: bioelectric signal control, contact force signal and manual switch control. Biosignal control (such as surface electromyography signal control) collects bioelectric signals from the body surface and then calculates the wearer's lower limb movement intention. It has the advantages of short delay and strong real-time performance, but it also has the disadvantages of cumbersome wearing, unsafe contact between electrodes and human skin, and easy detachment of electrodes. Contact force signal control mainly obtains the wearer's movement intention by collecting the relative pressure signal between the human lower limb and the robot's lower limb. It has the advantages of easy wearing and simple structure, but it has the disadvantages of slow pressure signal response and poor power-assisting effect. Manual switch quantity control mainly uses hand-operated switch on and off to realize the acquisition of movement intention. It has the advantages of simple structure and low cost, but it also has the disadvantages of cumbersome control, difficult movement coordination, and one or both hands being occupied. At present, at home and abroad, the control methods of power-assisted lower limb exoskeleton robots are mostly studied in bioelectric control or contact force control, but EEG, electrical signal sensors and force sensors are expensive, cumbersome to use, and have poor reliability. Therefore, it is urgent to study a highly reliable and easy-to-implement control system to meet people's needs for the design of power-assisted lower limb exoskeleton robots. Summary of the invention

[0004] The present invention aims to address the deficiencies of the above-mentioned prior art and proposes a control system for an assisted lower limb exoskeleton robot, so as to plan the output of the assist torque of the left and right hip joint motors and the smooth switching between gaits without affecting the wearer's normal walking, occupying both hands, and adding extra burden, thereby achieving the purpose of providing active assistance for the wearer's lower limb movement.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme:

[0006] The present invention discloses a control system for a power-assisted lower limb exoskeleton robot, the power-assisted lower limb exoskeleton robot comprises: a robot waist restraint device, a robot left thigh, a robot right thigh, a robot left calf, and a robot right calf; the control system comprises: an angle sensor, a potentiometer module, a microcontroller, a motor driver module, and a joint motor module; wherein the joint motor module comprises: a robot left hip joint motor and a robot right hip joint motor; the potentiometer module comprises: a left potentiometer and a right potentiometer;

[0007] The angle sensor is arranged at the middle position of the wearer's waist and connected to the wearer's waist through the robot waist restraint device, and is used to collect left and right swing angle signals of the wearer's waist and output them to the microcontroller;

[0008] The potentiometer module outputs left and right analog voltage signals and sends them to the microcontroller;

[0009] The microcontroller calculates the left and right torque signals according to the received left and right swing angle signals of the waist and the left and right analog voltage signals and transmits them to the motor driver module, so as to control the left and right output torques of the joint motor module within the specified angle range, so that the robot left hip joint motor and the robot right hip joint motor respectively drive the robot left thigh and the robot right thigh to move, thereby driving the wearer's lower limbs to move;

[0010] The microcontroller determines whether the actual output angles of the left hip joint motor and the right hip joint motor of the robot are within the range of 0~90° based on the angle information of the encoders of the left hip joint motor and the right hip joint motor of the robot. If exceeded, the output torque of the corresponding robot hip joint motor is gradually reduced until the angle returns to the range of 0~90°.

[0011] The control system of the power-assisted lower limb exoskeleton robot described in the present invention is also characterized in that the microcontroller includes: an angle signal calculation module, a digital / analog conversion module, and a joint motor control module;

[0012] The angle signal calculation module calculates the received left and right swing angle signals to obtain the angle coefficient K related to the output torque of the joint motor module. a =α / α m , and sent to the joint motor control module, where α represents the current left and right swing angle values, α m Indicates the maximum left and right swing angle values; and K a ∈[-1,1]; when the left and right swing angle signals are 0, it means that the wearer's waist is in the middle position, let K a =0; when the absolute value of the left and right swing angle signals reaches the maximum, let |K a |=1; when the wearer's waist swings to the left, let K a >0, indicating that the wearer's waist swings in the positive direction. When the wearer's waist swings to the right, let K a <0, indicating that the wearer's waist swings in the negative direction;

[0013] The digital / analog conversion module performs digital-to-analog conversion on the received left and right analog voltage signals to obtain left and right digital signals, and converts the left and right digital signals into left potentiometer coefficients K between 0 and 1 according to the rotation range of the potentiometer module. b1 =V in1 / V m and the right potentiometer coefficient K b2 =V in2 / V m , and sent to the joint motor control module, where V in1 is the analog voltage output by the left potentiometer, V in2 is the analog voltage output by the right potentiometer, V m is the maximum voltage value that the potentiometer can output; and K b ∈[0,1], when the potentiometer module rotates counterclockwise to the starting position, let K b =0, when the potentiometer module rotates clockwise to the end position, let K b =1; when the potentiometer module rotates clockwise, the output analog voltage increases; when the potentiometer module rotates counterclockwise, the output analog voltage decreases;

[0014] The joint motor control module is for the angle coefficient K a and the left potentiometer coefficient K b1 and the right potentiometer coefficient K b2 Logical analysis and judgment are performed to obtain the output torque of the robot's left hip joint motor and the robot's right hip joint motor, and corresponding control instructions are generated and sent to the motor driver module.

[0015] Furthermore, the joint motor control module adjusts the angle coefficient K according to the following steps:a and the left potentiometer coefficient K b1 and the right potentiometer coefficient K b2 Conduct logical analysis and judgment:

[0016] Step a: Determine K according to the wearer's waist position a The size and sign of:

[0017] If the wearer's waist is in the middle position, K a =0;

[0018] If the wearer's waist swings to the left, K a >0;

[0019] If K a When <0, it means the wearer's waist swings to the right;

[0020] Step b: According to K a The magnitude and positive / negative of is used to determine the output torque of the robot's left hip joint motor and the robot's right hip joint motor:

[0021] If K a =0, the total coefficient K of the robot's left hip joint motor c1 =K a ×K b1 =0, the total coefficient K of the robot's right hip joint motor c2 =K a ×K b2 =0, then both the left hip joint motor and the right hip joint motor of the robot output zero torque;

[0022] If K a >0, the total coefficient K c1 =K a ×K b1 >0, the robot's left hip joint motor outputs a counter torque, driving the robot's left thigh and left calf to complete the upright action, and the robot's right hip joint motor outputs a positive torque, driving the robot's right thigh and right calf to complete the lifting action;

[0023] If K a <0, the total coefficient K c2 =K a ×K b2 <0, the left hip joint motor of the robot outputs a positive torque, driving the left thigh and the left calf of the robot to complete the lifting action, and the right hip joint motor of the robot outputs a reverse torque, driving the right thigh and the right calf of the robot to complete the upright action;

[0024] Step c: Adjust the position of the potentiometer module according to the output torque of the robot hip joint motor:

[0025] When Ka =1, that is, when the wearer's waist swings to the leftmost end, if the robot's right thigh can be lifted to 90°, it means that the output torque of the robot's right hip joint motor is appropriate, and the position of the left potentiometer remains unchanged;

[0026] When K a =-1, that is, when the wearer's waist swings to the rightmost end, if the robot's left thigh can be lifted to 90°, it means that the output torque of the robot's left hip joint motor is appropriate, and the position of the right potentiometer remains unchanged;

[0027] When K a =1, the robot's right thigh lifting angle does not reach 90°, which means that the output torque of the robot's right hip joint motor is too small, and the knob of the left potentiometer is adjusted clockwise to increase the left potentiometer coefficient K. b1 ;

[0028] When K a =-1, the robot's left thigh lift angle does not reach 90°, which means that the output torque of the robot's left hip joint motor is too small, and the knob of the right potentiometer is adjusted clockwise to increase the right potentiometer coefficient K. b2 ;

[0029] When 0 <K a <1, the robot's right thigh lift angle exceeds 90°, which means that the output torque of the robot's right hip joint motor is too large, and the left potentiometer knob should be adjusted counterclockwise to reduce the left potentiometer coefficient K. b1 ;

[0030] When -1 <K a <0, the robot's left thigh lift angle exceeds 90°, which means that the output torque of the robot's left hip joint motor is too large, and the knob of the right potentiometer is adjusted counterclockwise to reduce the right potentiometer coefficient K. b2 .

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1. The present invention is directed to a power-assisted lower limb exoskeleton robot and proposes a power-assisted lower limb exoskeleton robot control system. The control system obtains the motion control signal parameters of the left and right hip joint motors by collecting the waist swing angle of the wearer during walking, and outputs control instructions to drive the joint motors, thereby achieving the power assistance of the joint motors to the wearer's lower limb movements, thereby achieving the purpose of the robot leading the wearer's lower limb movements.

[0033] 2. The potentiometer involved in the present invention is used to adjust the power-assisting effect, and the power-assisting coefficient can be adjusted in real time to meet the power-assisting needs of different people, and is more adaptable to wearers of different age groups;

[0034] 3. The joint motor involved in the present invention adopts a torque mode (also called a current mode), which can well adapt to the change of the external load torque, and can effectively avoid the failure of the motor due to overload protection, making the control system run more stable and reliable;

[0035] 4. The control system involved in the present invention adopts an embedded design, and designs the control board according to the mechanical structure shape of the robot to minimize the space occupied by the control board; a small and easy-to-install magnetic encoder is used as an angle sensor, a precision resistor is used as a potentiometer, and the power-assisting motor adopts a bus-type joint motor, which reduces the volume of the cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a schematic diagram of the overall mechanical structure of the exoskeleton in an embodiment of the present invention;

[0037] Figure 2 Schematic diagram of left-right swinging of the waist in an embodiment of the present invention;

[0038] Figure 3 is a schematic diagram of unilateral movement in an embodiment of the present invention;

[0039] Figure 4 is a schematic diagram of the control system structure in an embodiment of the present invention;

[0040] Figure 5 is a schematic diagram of a control flow in an embodiment of the present invention;

[0041] Figure 6 It is a schematic diagram of the logic analysis and judgment flow of the microcontroller in an embodiment of the present invention;

[0042] Figure 7 1 is a schematic diagram of the joint motor angle protection process in an embodiment of the present invention;

[0043] Numbers in the figure: 1. Robot waist restraint device; 2. Angle sensor; 3. Robot left hip joint motor; 4. Robot right hip joint motor; 5. Robot left thigh; 6. Robot right thigh; 7. Robot left passive knee joint; 8. Robot right passive knee joint; 9. Robot left calf; 10. Robot right calf; 11. Robot left thigh restraint device; 12. Robot right thigh restraint device; 13. Robot left calf restraint device; 14. Robot right calf restraint device; 15. Robot left boot; 16. Robot right boot; 17. Electronic control unit. DETAILED DESCRIPTION

[0044] In this embodiment, a control system for a power-assisted lower limb exoskeleton robot is an important component of the power-assisted exoskeleton robot. Figure 1The control system is an electronic control unit 17 of the power-assisted exoskeleton robot, and is assembled with the robot waist restraint device 1, the angle sensor 2, the robot left hip joint motor 3, the robot right hip joint motor 4, the robot left thigh 5, the robot right thigh 6, the robot left passive knee joint 7, the robot right passive knee joint 8, the robot left calf 9, the robot right calf 10, the robot left thigh restraint device 11, the robot right thigh restraint device 12, the robot left calf restraint device 13, the robot right calf restraint device 14, the robot left boot 15, and the robot right boot 16 to form a complete power-assisted lower limb exoskeleton robot; the internal structure of the control system is shown in FIG. Figure 4 , including: an angle sensor 2, a potentiometer module, a microcontroller, a motor drive module, a joint motor module and a power module; wherein the potentiometer module includes a left potentiometer and a right potentiometer; the joint motor module includes: a robot left hip joint motor 3 and a robot right hip joint motor 4; the power module supplies power to the control system, and internally includes: a lithium battery pack and a step-down circuit;

[0045] The angle sensor 2 is set at the middle position of the wearer's waist and is connected to the wearer's waist through the robot waist restraint device 1. It is used to collect the left and right swing angle signals of the wearer's waist and output them to the microcontroller. Figure 2 ;

[0046] The potentiometer module includes: a left potentiometer and a right potentiometer, which are implemented by precision multi-turn resistors, output left and right analog voltage signals, and send them to the microcontroller;

[0047] The microcontroller uses a high-performance ARM-type single-chip microcomputer as the main control chip. The main frequency of the chip can reach 72MHz. The SPI interface and ADC module are integrated inside. The angle digital signal of the angle sensor can be directly read through the SPI interface, and the analog voltage signal output by the left and right potentiometers can be collected through the internal ADC module; the microcontroller calculates the left and right torque signals based on the received left and right swing angle signals of the waist and the left and right analog voltage signals and transmits them to the motor drive module to control the left and right output torque of the joint motor module within the specified angle range, so that the robot's left hip joint motor 3 and the robot's right hip joint motor 4 respectively drive the robot's left thigh 5 and the robot's right thigh 6 to move, thereby driving the wearer's lower limbs to move. For the work flow, please refer to Figure 5 As shown;

[0048] The microcontroller contains three processing units: angle signal calculation module, digital / analog conversion module, and joint motor control module;

[0049] The angle signal calculation module calculates the received left and right swing angle signals to obtain the angle coefficient K related to the output torque of the joint motor module. a =α / αm , and sent to the joint motor control module, where α represents the current left and right swing angle values, α m Indicates the maximum left and right swing angle values; and K a ∈[-1,1]; when the left and right swing angle signals are 0, it means that the wearer's waist is in the middle position, let K a =0; when the absolute value of the left and right swing angle signals reaches the maximum, let |K a |=1; when the wearer's waist swings to the left, let K a >0, indicating that the wearer's waist swings in the positive direction, and when it swings to the leftmost end, K a =1; when the wearer's waist swings to the right, let K a <0, indicating that the wearer's waist swings in the negative direction. When it swings to the rightmost end, K a =-1;

[0050] The digital / analog conversion module performs digital-to-analog conversion on the received left and right analog voltage signals to obtain left and right digital signals, and converts the left and right digital signals into left potentiometer coefficients K between 0 and 1 according to the rotation range of the potentiometer module. b1 =V in1 / V m and the right potentiometer coefficient K b2 =V in2 / V m , and sent to the joint motor control module, where V in1 is the analog voltage output by the left potentiometer, V in2 is the analog voltage output by the right potentiometer, V m is the maximum voltage value that the potentiometer can output, and K b ∈[0,1], when the potentiometer module rotates counterclockwise to the starting position, let K b =0, when the potentiometer module rotates clockwise to the end position, let K b =1; when the potentiometer module rotates clockwise, the output analog voltage increases, and the potentiometer coefficient K b Increase; when the potentiometer module rotates counterclockwise, the output analog voltage decreases, and the potentiometer coefficient K b reduce;

[0051] Joint motor control module angle coefficient K a and the left potentiometer coefficient K b1 and the right potentiometer coefficient K b2 Logical analysis and judgment are performed to obtain the output torque of the robot's left hip joint motor 3 and the robot's right hip joint motor 4, and corresponding control instructions are generated and sent to the motor driver module.

[0052] See also Figure 6The joint motor control module adjusts the angle coefficient K according to the following specific steps: a and the left potentiometer coefficient K b1 and the right potentiometer coefficient K b2 Conduct logical analysis and judgment:

[0053] Step a: Determine K according to the wearer's waist position a The size and sign of:

[0054] If the wearer's waist is in the middle position, K a =0;

[0055] If the wearer's waist swings to the left, K a >0;

[0056] If K a When <0, it means the wearer's waist swings to the right;

[0057] Step b: According to K a The magnitude and positive / negative of is used to determine the output torque of the robot's left hip joint motor 3 and the robot's right hip joint motor 4:

[0058] If K a =0, the total coefficient K of the robot's left hip joint motor 3 c1 =K a ×K b1 =0, the total coefficient K of the robot's right hip joint motor 4 c2 =K a ×K b2 =0, then the left hip joint motor 3 and the right hip joint motor 4 of the robot both output zero torque;

[0059] If K a >0, the total coefficient K c1 =K a ×K b1 >0, the robot's left hip joint motor 3 outputs a reaction torque to drive the robot's left thigh 5 and the robot's left calf 9 to complete the upright action, and the robot's right hip joint motor 4 outputs a positive torque to drive the robot's right thigh 6 and the robot's right calf 10 to complete the lifting action;

[0060] If K a <0, the total coefficient K c2 =K a ×K b2 <0, the robot's left hip joint motor 3 outputs a positive torque, driving the robot's left thigh 5 and the robot's left calf 9 to complete the lifting action, and the robot's right hip joint motor 4 outputs a counter torque, driving the robot's right thigh 6 and the robot's right calf 10 to complete the upright action;

[0061] Step c: Adjust the position of the potentiometer module according to the output torque of the robot hip joint motor:

[0062] When K a =1, that is, when the wearer's waist swings to the leftmost end, if the robot's right thigh 6 can be lifted to 90°, it means that the output torque of the robot's right hip joint motor 4 is appropriate, and the position of the left potentiometer remains unchanged;

[0063] When K a =-1, that is, when the wearer's waist swings to the rightmost end, if the robot's left thigh 5 can be lifted to 90°, it means that the output torque of the robot's left hip joint motor 3 is appropriate, and the position of the right potentiometer remains unchanged;

[0064] When K a =1, the robot's right thigh 6 does not lift up to 90°, which means the output torque of the robot's right hip joint motor 4 is too small, and the left potentiometer knob is adjusted clockwise to increase the left potentiometer coefficient K b1 ;

[0065] When K a =-1, the robot's left thigh 5 does not lift up to 90°, which means the output torque of the robot's left hip joint motor 3 is too small, and the knob of the right potentiometer is adjusted clockwise to increase the right potentiometer coefficient K. b2 ;

[0066] When 0 <K a <1, the robot's right thigh 6 lifts up at an angle of more than 90°, indicating that the output torque of the robot's right hip joint motor 4 is too large, and the knob of the left potentiometer is adjusted counterclockwise to reduce the left potentiometer coefficient K. b1 ;

[0067] When -1 <K a <0, the robot's left thigh 5 lifts up at an angle of more than 90°, indicating that the output torque of the robot's left hip joint motor 3 is too large, and the knob of the right potentiometer is adjusted counterclockwise to reduce the right potentiometer coefficient K b2 .

[0068] In order to prevent the robot's hip joint motor from moving too much and causing damage to the wearer's lower limbs, the microcontroller will determine the actual output angle γ of the robot's left hip joint motor 3 based on the angle information of the robot's left hip joint motor 3 and the robot's right hip joint motor 4. L and the actual output angle γ of the robot's right hip joint motor 4 R Is it within the range of 0~90°? Figure 3 If it exceeds, the output torque of the corresponding robot hip joint motor will be gradually reduced until the angle returns to the range of 0~90°. For the specific process, please refer to Figure 7 .

[0069] The above embodiments are only for illustrating the technical concept and features, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A control system for a power-assisted lower limb exoskeleton robot, the power-assisted lower limb exoskeleton robot comprising: A robot waist restraint device (1), a robot left thigh (5), a robot right thigh (6), a robot left calf (9), and a robot right calf (10); characterized in that the control system comprises: an angle sensor (2), a potentiometer module, a microcontroller, a motor driver module, and a joint motor module; wherein the joint motor module comprises: a robot left hip joint motor (3) and a robot right hip joint motor (4); the potentiometer module comprises: a left potentiometer and a right potentiometer; The angle sensor (2) is arranged at the middle position of the wearer's waist and is connected to the wearer's waist through the robot waist restraint device (1), and is used to collect left and right swing angle signals of the wearer's waist and output them to the microcontroller; The potentiometer module outputs left and right analog voltage signals and sends them to the microcontroller; The microcontroller calculates left and right torque signals based on the received left and right swing angle signals of the waist and the left and right analog voltage signals and transmits them to the motor driver module, so as to control the left and right output torques of the joint motor module within a specified angle range, so that the robot left hip joint motor (3) and the robot right hip joint motor (4) respectively drive the robot left thigh (5) and the robot right thigh (6) to move, thereby driving the wearer's lower limbs to move; The microcontroller determines whether the angles actually output by the left hip joint motor (3) and the right hip joint motor (4) of the robot are within the range of 0 to 90 degrees according to the angle information of the encoders of the left hip joint motor (3) and the right hip joint motor (4) of the robot. If the angles are exceeded, the output torque of the corresponding robot hip joint motor is gradually reduced until the angle returns to the range of 0 to 90 degrees.

2. The control system of the power-assisted lower limb exoskeleton robot according to claim 1, characterized in that: The microcontroller comprises: an angle signal calculation module, a digital / analog conversion module, and a joint motor control module; The angle signal calculation module calculates the received left and right swing angle signals to obtain the angle coefficient K related to the output torque of the joint motor module. a =α / α m , and sent to the joint motor control module, where α represents the current left and right swing angle values, α m Indicates the maximum left and right swing angle values; and K a ∈[-1,1]; when the left and right swing angle signals are 0, it means that the wearer's waist is in the middle position, let K a =0; when the absolute value of the left and right swing angle signals reaches the maximum, let |K a |=1; when the wearer's waist swings to the left, let K a >0, indicating that the wearer's waist swings in the positive direction. When the wearer's waist swings to the right, let K a <0, indicating that the wearer's waist swings in the negative direction; The digital / analog conversion module performs digital-to-analog conversion on the received left and right analog voltage signals to obtain left and right digital signals, and converts the left and right digital signals into left potentiometer coefficients K between 0 and 1 according to the rotation range of the potentiometer module. b1 =V in1 / V m and the right potentiometer coefficient K b2 =V in2 / V m , and sent to the joint motor control module, where V in1 is the analog voltage output by the left potentiometer, V in2 is the analog voltage output by the right potentiometer, V m is the maximum voltage value that the potentiometer can output; and K b ∈[0,1], when the potentiometer module rotates counterclockwise to the starting position, let K b =0, when the potentiometer module rotates clockwise to the end position, let K b =1; when the potentiometer module rotates clockwise, the output analog voltage increases; when the potentiometer module rotates counterclockwise, the output analog voltage decreases; The joint motor control module is for the angle coefficient K a and the left potentiometer coefficient K b1 and the right potentiometer coefficient K b2 Logical analysis and judgment are performed to obtain the output torque of the robot's left hip joint motor (3) and the robot's right hip joint motor (4), and corresponding control instructions are generated and sent to the motor driver module.

3. The control system of the lower limb assisting exoskeleton robot according to claim 2, characterized in that: The joint motor control module is to adjust the angle coefficient K according to the following steps a and the left potentiometer coefficient K b1 and the right potentiometer coefficient K b2 Conduct logical analysis and judgment: Step a: Determine K according to the wearer's waist position a The size and sign of: If the wearer's waist is in the middle position, K a =0; If the wearer's waist swings to the left, K a >0; If K a When <0, it means the wearer's waist swings to the right; Step b: According to K a The magnitude and positive / negative value of is used to determine the output torque of the robot's left hip joint motor (3) and the robot's right hip joint motor (4): If K a =0, the total coefficient K of the robot's left hip joint motor (3) c1 =K a ×K b1 =0, the total coefficient K of the robot's right hip joint motor (4) c2 =K a ×K b2 =0, then the left hip joint motor (3) and the right hip joint motor (4) of the robot both output zero torque; If K a >0, the total coefficient K c1 =K a ×K b1 >0, the robot's left hip joint motor (3) outputs a counter torque, driving the robot's left thigh (5) and the robot's left calf (9) to complete an upright motion, and the robot's right hip joint motor (4) outputs a positive torque, driving the robot's right thigh (6) and the robot's right calf (10) to complete a lifting motion; If K a <0, the total coefficient K c2 =K a ×K b2 <0, the robot's left hip joint motor (3) outputs a positive torque, driving the robot's left thigh (5) and the robot's left calf (9) to complete the lifting action, and the robot's right hip joint motor (4) outputs a counter torque, driving the robot's right thigh (6) and the robot's right calf (10) to complete the upright action; Step c: Adjust the position of the potentiometer module according to the output torque of the robot hip joint motor: When K a =1, that is, when the wearer's waist swings to the leftmost end, if the robot's right thigh (6) can be lifted to an angle of 90°, it means that the output torque of the robot's right hip joint motor (4) is appropriate, and the position of the left potentiometer remains unchanged; When K a = -1, that is, when the wearer's waist swings to the rightmost end, if the robot's left thigh (5) can be lifted to an angle of 90°, it means that the output torque of the robot's left hip joint motor (3) is appropriate, and the position of the right potentiometer remains unchanged; When K a =1, the robot's right thigh (6) does not lift up to 90°, which means the output torque of the robot's right hip joint motor (4) is too small, and the left potentiometer knob is adjusted clockwise to increase the left potentiometer coefficient K. b1 ; When K a = -1, the robot's left thigh (5) does not lift up to 90°, which means the output torque of the robot's left hip joint motor (3) is too small, and the knob of the right potentiometer is adjusted clockwise to increase the right potentiometer coefficient K. b2 ; When 0 <K a When the robot's right thigh (6) is lifted at an angle of more than 90°, it means that the output torque of the robot's right hip joint motor (4) is too large, and the knob of the left potentiometer is adjusted counterclockwise to reduce the left potentiometer coefficient K. b1 ; When -1 <K a When the robot's left thigh (5) is lifted at an angle of more than 90°, it means that the output torque of the robot's left hip joint motor (3) is too large, and the knob of the right potentiometer is adjusted counterclockwise to reduce the right potentiometer coefficient K. b2 .

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