An adaptive control system for a modular joint of a bionic arm

Abstract

The application relates to an adaptive control system of a bionic arm modular joint, which is installed between a bionic arm and a human shoulder, and the system comprises a collection module, a processing module, an adaptive controller module and a torque calculator module; the collection module obtains an initial control voltage group; after being processed by the processing module, a load torque, an input current and an input rotating speed are obtained; the load torque, the input current, the input rotating speed and a preset rated rotating speed are input into the adaptive controller module to obtain a first voltage group; after being processed by the processing module, a compensation control voltage of the modular joint is obtained; the compensation control voltage is input into the processing module to obtain an encoding value; and the processing module drives the modular joint according to the encoding value. Compared with the prior art, the adaptive control requirement is realized by obtaining an easily controlled current voltage value, and the application has the advantages of strong real-time performance, accurate control and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bionic medical devices, in particular to a self-adaptive control system of a bionic arm modular joint. BACKGROUND

[0002] Upper limb amputees lack normal physical functions, and it is difficult for them to take care of themselves in work and life, thus giving rise to the demand for upper limb prosthesis research. As the power source of intelligent bionic prosthesis, the modular joint has lower weight, higher integration and more accurate control compared with traditional bionic mechanical arms. However, due to the square wave drive of the brushless direct current motor in the modular joint and the nonlinear friction torque in the harmonic reducer, this belongs to the internal uncertain variables of the modular joint, which greatly affects the dynamic performance of the joint module system. The traditional control based on the modular joint ignores the dynamic characteristics of the system, and cannot meet the control requirements of complex nonlinear systems, which leads to large error, easy overshoot and oscillation, and cannot meet the control requirements of bionic arm prosthesis. SUMMARY

[0003] The purpose of the present application is to overcome the defects of the prior art and provide a self-adaptive control system of a bionic arm modular joint.

[0004] The purpose of the present application can be achieved by the following technical solutions:

[0005] A self-adaptive control system of a bionic arm modular joint, the modular joint is installed between a bionic arm and a human shoulder, comprising a collection module, a processing module, a self-adaptive controller module and a torque calculator module;

[0006] The collection module obtains an initial control voltage group of the modular joint, and obtains a to-be-input current group and a to-be-input rotating speed after processing by the processing module;

[0007] After inputting the to-be-input current group and the to-be-input rotating speed into the torque calculator module, a load torque is obtained, and the load torque, the to-be-input current, the to-be-input rotating speed and a preset rated rotating speed are input into the self-adaptive controller module to obtain a first voltage group;

[0008] The first voltage group is processed by the processing module to obtain a compensation control voltage of the modular joint, the compensation control voltage is input into the processing module to obtain an encoding value, and the processing module drives the modular joint according to the encoding value.

[0009] Further, the processing module comprises an SVPWM device, an inverter, a Clarke converter, a Park converter, a rotor position sensor and an inverse Park converter,

[0010] The first current group is converted into three-phase current by the SVPWN and the inverter, and then input into the Clarke converter to obtain;

[0011] The input current group is input into the Park converter by the Clarke converter to obtain;

[0012] The input speed is input into the rotor position sensor by the Clarke converter, and the rotor position sensor is combined with the control voltage to obtain;

[0013] The compensation control voltage is obtained by inputting the first voltage group into the inverse Park converter

[0014] The encoding value is obtained by inputting the compensation control voltage into the SVPWN and the inverter again, and the inverter drives the modular joint according to the encoding value.

[0015] Further, when the modular joint needs to be adaptively adjusted again, the encoding value output by the inverter can be used as the three-phase current of the next adaptive control, and directly input into the Clarke converter to complete the second adaptive control.

[0016] Further, the control board of the adaptive controller module is STM32.

[0017] Further, the inverter drives the modular joint through the MOS tube switch.

[0018] Further, one end of the modular joint is connected to the human shoulder, and the other end is connected to the bionic arm, the modular joint can be detached from the human shoulder, and the adaptive control system is installed on the end of the modular joint close to the human shoulder.

[0019] Further, the acquisition module in the adaptive control device comprises a voltage sensor.

[0020] Compared with the prior art, the present application has the following advantages:

[0021] 1、The adaptive controller and the torque change calculator are used to control the modular joint by calculating the voltage, current and speed of the modular joint, and the overall control of the system can be completed by compensating the current and voltage values, which eliminates the uncertain variables in the system and improves the accuracy and stability of the control.

[0022] 2、The adaptive controller used in the present application is based on STM32 control board, which is more accurate.

[0023] 3、The adaptive control system of the bionic arm modular joint according to the present application has strong real-time performance and anti-interference capability.

[0024] 4、The present application uses Clarke converter and Park converter in the processing module, and the efficiency is higher when processing the three-phase current output by the modular joint, and the processing is more simplified. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The adaptive control system structure of the present application is shown in the figure. DETAILED DESCRIPTION

[0026] The present application will be described in detail below in combination with the drawings and specific embodiments. The present application is implemented on the premise of the technical solution of the present application, and detailed implementation and specific operation process are given, but the protection scope of the present application is not limited to the following embodiments.

[0027] The present embodiment provides an adaptive control system of a bionic arm modular joint. It should be noted that the modular joint is a component installed between the bionic arm and the human shoulder and used as a power source. The structure diagram of the adaptive control system is shown in Figure 1 The adaptive control system includes a collection module, a processing module, an adaptive controller module and a torque calculator module. The working process is as follows:

[0028] The collection module obtains the initial control voltage group of the modular joint, and obtains the input current group and the input speed after processing by the processing module.

[0029] The input current group and the input speed are input into the torque calculator module to obtain the load torque. The load torque, the input current, the input speed and the rated speed set in advance are input into the adaptive controller module to obtain the first voltage group.

[0030] The first voltage group is processed by the processing module to obtain the compensation control voltage of the modular joint. The compensation control voltage is input into the processing module to obtain the code value, and the processing module drives the modular joint according to the code value.

[0031] The specific expansion of each module is as follows. The collection module is a voltage sensor connected with the modular joint. When the modular joint is running, the collection module detects the voltage u α and u β of the modular joint and transmits them to the processing module.

[0032] The processing module specifically includes: SVPWM device, three-phase inverter, Clarke converter, Park converter, rotor position sensor and inverse Park converter. The specific working process is as follows:

[0033] Firstly, the SVPWM device receives the initial control voltage group u α and u β to obtain three-phase PWM pulses and transmits the three-phase PWM pulses to a three-phase inverter, which converts them into three-phase currents i a , i b , i c , transmits them to a Clarke converter, which Clarke-converts the obtained three-phase currents to obtain a current group i α and i β , and transmits them to a rotor position sensor and a Park converter, respectively.

[0034] After the rotor position sensor receives u α , u β , i α and i β , the input speed ω r of the modular joint is obtained, the Park converter Park-converts the obtained current group to obtain a current group i d and i q .

[0035] Then, i d , i q and ω r are transmitted to a torque calculator module, which is a calculator containing the internal and external influences of the modular joint, and can calculate the load torque of the modular joint after being blocked according to i d , i q and ω r .

[0036] Then, i d , i q , ω r and are transmitted to an adaptive controller module, which contains an adaptive controller based on STM32, wherein a preset rated speed ω rd is set, i d , i q , ω r and and the rated speed ω rd are sent to the adaptive controller, the adaptive controller compares the input speed ω r with the rated speed ω rd , and then feeds back the difference to the circuit information, thereby obtaining a voltage group u d and u q , and the voltage group u d and u qThe transmission voltage group is subjected to inverse Park transformation.

[0037] The inverse Park transformer subjects the first voltage group to inverse Park transformation to obtain the compensation control voltage u α ' of the modular joint. β ' of the modular joint. α ' of the modular joint. β ' of the modular joint are input into the SVPWM device again for modulation to obtain three-phase PWM pulses and input into the three-phase inverter to output the code value, and the MOS switch of the three-phase inverter receives the code value to drive the modular joint to change the operating state, thus completing the adaptive control of the modular joint.

[0038] It is worth mentioning that the rated rotating speed ω rd set may change according to the debugging needs, and in order to maintain the normal operation of the modular joint, the second adaptive control is needed. At this time, the initial control voltage of the modular joint does not need to be collected again as the input value, and the code value output by the three-phase inverter can be directly used as the three-phase current i a , i b , i c input into the Clarke transformer to complete the second adaptive control.

[0039] In the embodiment, the adaptive controller system can be applied to different types of modular joints because it only reads the voltage, current and rotating speed of the modular joint.

[0040] The modular joint is connected to the human shoulder at one end and to the bionic arm at the other end. Since the connection between the modular joint and the human shoulder is easy to disassemble and install, and the connection between the modular joint and the bionic arm is difficult to disassemble and install, in order to facilitate the adjustment and maintenance of the adaptive control system, the adaptive control system is arranged at the end of the modular joint close to the human shoulder in the embodiment, so that the maintenance of the adaptive control system is more convenient after the modular joint is disassembled from the human shoulder.

[0041] The preferred embodiments of the application are described in detail above. It should be understood that those skilled in the art can make many modifications and changes to the embodiments without creative efforts based on the concept of the application. Therefore, any technical solutions obtained by logical analysis, reasoning or limited experiments based on the prior art according to the concept of the application shall be within the protection scope defined by the claims.

Claims

1. An adaptive control system for a modular joint of a bionic arm, the modular joint being installed between the bionic arm and a human shoulder, characterized in that, The adaptive control device comprises a collecting module, a processing module, an adaptive controller module and a torque calculator module. The collecting module acquires an initial control voltage group of the modular joint, and the initial control voltage group is processed by the processing module to obtain a to-be-input current group and a to-be-input rotating speed. The to-be-input current group and the to-be-input rotating speed are input into the torque calculator module to obtain a load torque, and the load torque, the to-be-input current, the to-be-input rotating speed and a preset rated rotating speed are input into the adaptive controller module to obtain a first voltage group. The first voltage group is processed by the processing module to obtain a compensation control voltage of the modular joint, the compensation control voltage is input into the processing module to obtain an encoding value, and the processing module drives the modular joint according to the encoding value. The processing module comprises an SVPWM device, an inverter, a Clarke converter, a Park converter, a rotor position sensor and an inverse Park converter. The first voltage group is converted into a three-phase current by the SVPWN device and the inverter, and the three-phase current is input into the Clarke converter to obtain the to-be-input current group. The to-be-input current group is input into the Park converter by the Clarke converter. The to-be-input rotating speed is input into the rotor position sensor by the Clarke converter, and the rotor position sensor calculates the to-be-input rotating speed in combination with the control voltage. The compensation control voltage is obtained by inputting the first voltage group into the inverse Park converter. The encoding value is obtained by inputting the compensation control voltage into the SVPWN device and the inverter again, and the inverter drives the modular joint according to the encoding value. When the modular joint needs to be adaptively adjusted again, the encoding value output by the inverter can be used as three-phase current for the next adaptive control, and the three-phase current is directly input into the Clarke converter to complete the second adaptive control. One end of the modular joint is connected to a human shoulder, and the other end is connected to a bionic arm, the modular joint can be detached from the human shoulder, and the adaptive control system is installed at one end of the modular joint close to the human shoulder.

2. The adaptive control system of a modular joint of a bionic arm according to claim 1, wherein, The control board of the adaptive controller module is an STM32.

3. The adaptive control system of a modular joint of a bionic arm according to claim 1, wherein, The inverter drives the modular joint by means of MOS tube switching.

4. The adaptive control system of a modular joint of a bionic arm according to claim 1, wherein, The collecting module in the adaptive control device comprises a voltage sensor.

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