Flexibly-driven walking rehabilitation training robot system and motion control method

Abstract

The invention discloses a flexibly-driven walking rehabilitation training robot system and a motion control method. The robot system comprises an outer frame, an active weight reduction unit and an omni-directional moving unit. The control method comprises the steps that an upper computer sends out an expected force track to drive the robot to act, a driving motor is started to drive a person to move, a first angle encoder, a second angle encoder and a force sensor detect angle change information and pulling force information of a pulling rope, and the pulling force information serves as feedback to be input into a PID controller; angle information and tension information are input into a disturbance observer to estimate man-machine interaction disturbance and unmodeled errors of the system, the angle information and the tension information serve as correction of a PID controller to be input into the robot system again, iterative circulation is conducted, and the man-machine interaction force actually output by the robot accurately follows an expected track. According to the method, the requirement of active participation of the patient can be met, a quantitative and targeted walking training strategy is provided, and the purpose of carrying out walking rehabilitation function training on the patient is achieved.

Description

Technical Field

[0001] The invention relates to a rehabilitation training robot, in particular to a flexible-driven walking rehabilitation training robot system and a motion control method, and belongs to the technical field of robots. Background Art

[0002] Scientific sports rehabilitation training has a significant effect on improving the deterioration of patients' motor learning ability and promoting the rehabilitation of patients' limb functions. Among them, walking training is a commonly used rehabilitation training method. Scientific walking training can provide patients with sufficient sports stimulation information, promote the reconstruction of patients' motor learning ability, and improve patients' walking motor disorders.

[0003] In traditional walking training, rehabilitation therapists usually guide patients to walk in a one-on-one or even many-on-one manner, either with bare hands or with the help of certain rehabilitation training equipment. This training method is highly dependent on the professional skills and personal experience of rehabilitation therapists, and it is difficult for rehabilitation therapists to optimize and adjust the training conditions of patients in a timely manner. At the same time, the above-mentioned patients often have unilateral motor dysfunction, and it is difficult for rehabilitation therapists to provide quantitative and targeted rehabilitation assistance based on the different conditions on both sides of the patient's body.

[0004] Weight loss walking training can stimulate the patient's active participation and encourage them to actively control their gait and balance. It can independently provide patients with a large number of repetitive walking training, relieve the pressure of rehabilitation therapists and make up for the shortcomings caused by the current shortage of rehabilitation therapists.

[0005] Existing walking training weight-reduction devices usually allow patients to perform walking training on a treadmill. The weight-reduction devices only provide weight-reduction protection. The single weight-reduction force will significantly change the ground reaction force that people receive when walking, and seriously affect the gait parameters, which can easily lead to the solidification of the patient's gait and cannot meet the patient's actual walking movement learning and rehabilitation needs. At the same time, existing walking training weight-reduction devices usually cannot provide assistance for the different movement characteristics of the left and right sides of the human body, and there is no corresponding device to provide corresponding assistance in the forward direction to improve gait. Summary of the invention

[0006] The present invention overcomes the shortcomings of the prior art and provides a flexible-driven walking rehabilitation training robot system and a motion control method. The robot system can apply different weight-reducing forces to both sides of the patient's body for protection when the patient walks on the actual road surface, and provide forward assistance to improve gait. At the same time, it can meet the patient's needs for active participation and provide a quantitative and targeted walking training strategy.

[0007] A flexible driven walking rehabilitation training robot system comprises an outer frame, an active weight reduction unit and an omnidirectional movement unit;

[0008] The active weight reduction unit has two sets symmetrically distributed and installed on the upper cross beams on both sides of the outer frame. Each of the active weight reduction units includes a spatial angle measurement device, a traction rope and a driving device. One end of the traction rope is fixed to the driving device. The traction rope passes through the angle measurement device. The other end of the traction rope is used to be fixed to the shoulder binding device. The traction rope is controlled by the driving device to provide vertical upward weight reduction force and forward traction force for the human body.

[0009] The angle measuring device comprises a pulley, an angle sensor 1, a fixing seat 1, a fixing seat 2, an angle sensor 2 and a paddle; the fixing seat 1 is rotatably arranged on the outer frame, the angle sensor 1 is fixed on the fixing seat 1, the output shaft of the angle encoder 1 is connected to the rotating shaft of the fixing seat 2, the pulley is rotatably arranged in the groove 1 of the fixing seat 2, the paddle is fixed in the groove 2 of the fixing seat 2, the angle sensor is fixed on the fixing seat 2, the output shaft of the angle sensor 2 is connected to the rotating shaft of the paddle, and the traction rope is placed on the pulley and passes through the rope hole of the paddle. ; The angle sensor 1 is used to measure the rotation angle of the fixing seat 2 around the axis A; the paddle rotates around the axis B as the traction rope rotates; the angle sensor 2 is used to measure the rotation angle of the paddle around the axis B; the driving device includes a winding drum, a motor seat and a driving motor; the traction rope is wound around the winding drum, one end of the traction rope is fixed to the winding drum, the motor seat is fixed to the top crossbeam of the outer frame, the driving motor is fixed to the motor seat, the output shaft of the driving motor is fixed to the rotating shaft of the winding drum, and the winding drum is rotatably arranged on the motor seat;

[0010] The omnidirectional mobile unit is composed of four Mecanum wheel trains, which are fixed on the cross beams on both sides of the bottom of the outer frame, so that the robot can achieve omnidirectional movement on a plane.

[0011] A walking rehabilitation training motion control method is implemented based on the walking rehabilitation training robot system, and the control method comprises:

[0012] S1. Establish a disturbance observer

[0013]

[0014] Among them, τ L represents the traction torque, τ L =F·r / J, F is the measured value of the force sensor, l is the rope length, B is the motor viscous resistance coefficient, τ is the motor driving torque, J is the motor moment of inertia, θ is the motor rotation angle, and r is the radius of the pulley. The disturbance observer obtains the disturbance generated by humans or the environment and the unmodeled error of the system;

[0015] S2. Constructing the kinetic equation For the angular velocity and angular acceleration The positive feedback gain is used to compensate the mechanical impedance of the system;

[0016] S3. Design PID controller

[0017]

[0018] u(t) is the output of the PID controller, K p is the proportionality coefficient, T i is the integration time constant, T d is the differential time constant, e(t) is the difference between the desired tracking force trajectory and the actual output force of the system;

[0019] The host computer sends out the desired force trajectory to drive the robot to move, the drive motor starts to drive the person to move, and the angle encoder 1 and angle encoder 2 and the force sensor detect the angle change information and tension information of the traction rope. The tension information is input into the PID controller as feedback. The angle information and tension information are both input into the disturbance observer to estimate the human-machine interaction disturbance and the unmodeled error of the system, and are input into the robot system again as the correction amount of the PID controller. The iterative cycle is carried out to realize that the human-machine interaction force actually output by the robot accurately follows the desired trajectory.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present application utilizes an omnidirectional mobile unit that can follow a person's omnidirectional movement, utilizes an active weight reduction unit to provide the patient with different weight reduction forces on both sides of the body to compensate for gravity balance, and at the same time provides forward traction to improve the patient's walking gait. An angle measurement device is used to enable the robot to constantly change the weight reduction force and traction force applied to the patient, and to enable the robot to keep relative following the patient.

[0022] The design of the control strategy can provide corresponding assistance in the forward direction to improve gait and assist movement characteristics, thereby achieving the goal of functional training for walking rehabilitation for patients.

[0023] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments: BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic diagram of a flexible-driven walking rehabilitation training robot system of the present invention;

[0025] Figure 2 This is a front view of the flexible-driven walking rehabilitation training robot system of the present invention;

[0026] Figure 3 is a three-dimensional structural diagram of the active weight reduction unit of the present invention;

[0027] Figure 4 is a front view of the active weight reduction unit of the present invention;

[0028] Among them, 1. outer frame, 2. traction rope, 3. binding belt, 4. control box, 5. Mecanum wheel, 6. chassis motor, 7. rope fixing ring, 8. angle measuring device, 9. pulley, 10. angle encoder 1, 11. fixing seat 1, 12. fixing seat 2, 13. angle encoder 2, 14. paddle, 15. coupling, 16. winding drum, 17. motor seat, 18. driving motor;

[0029] Figure 5 It is a schematic diagram of the force decomposition of the traction rope of the present application;

[0030] Figure 6 It is the omnidirectional movement logic diagram of the robot system of the present application;

[0031] Figure 7 It is the walking rehabilitation training motion control block diagram of this application. DETAILED DESCRIPTION

[0032] The embodiments of the technical solution of the present application will be described in detail below in conjunction with the accompanying drawings. Unless otherwise specified, the technical terms or scientific terms used in the present application are generally understood by those skilled in the art.

[0033] Reference Figure 1-Figure 4 , a flexible driven walking rehabilitation training robot system of this embodiment includes an outer frame 1, an active weight reduction unit and an omnidirectional movement unit;

[0034] The active weight reduction unit has two sets symmetrically distributed and installed on the upper cross beams on both sides of the outer frame. Each of the active weight reduction units includes a spatial angle measurement device 8, a traction rope 2 and a driving device. One end of the traction rope 2 is fixed to the driving device. The traction rope 2 passes through the angle measurement device 8. The other end of the traction rope 2 is used to be fixed to the shoulder binding device. The traction rope 2 is controlled by the driving device to provide vertical upward weight reduction force and forward traction force for the human body.

[0035] Reference Figure 3The angle measuring device 8 includes a pulley 9, an angle sensor 10, a fixing seat 11, a fixing seat 2 12, an angle sensor 2 13 and a paddle 14; the fixing seat 11 is rotatably arranged on the outer frame 1, the angle sensor 10 is fixed on the fixing seat 11, the output shaft of the angle encoder 10 is connected to the rotating shaft of the fixing seat 2 12, the pulley 9 is rotatably arranged in the groove 1 of the fixing seat 2 12, the paddle 14 is fixed in the groove 2 of the fixing seat 2 12, the angle sensor 13 is fixed on the fixing seat 2 12, the output shaft of the angle sensor 2 13 is connected to the rotating shaft of the paddle 14, the traction rope 2 is placed on the pulley 9 and passes through the rope hole of the paddle 14; the angle sensor 10 is used to measure the rotation angle of the fixing seat 2 12 around the axis A; the paddle 14 rotates around the axis B with the rotation of the traction rope; the angle sensor 2 13 is used to measure the rotation angle of the paddle 14 around the axis B;

[0036] Reference Figure 3 and Figure 4 The driving device includes a winding drum 16, a motor seat 17 and a driving motor 18; the traction rope 2 is wound on the winding drum 16, one end of the traction rope 2 is fixed on the winding drum 16, the traction rope 2 is always in a straight state, and the traction ropes 2 on the left and right sides jointly provide a vertical upward weight-reducing force and a forward traction force acting on the human body, the motor seat 17 is fixed on the top crossbeam of the outer frame 1, the driving motor 18 is fixed on the motor seat 17, the output shaft of the driving motor 18 is fixed to the rotating shaft of the winding drum 16, and the winding drum 16 is rotatably arranged on the motor seat 17;

[0037] The omnidirectional mobile unit is composed of four Mecanum wheel trains, which are fixed on the cross beams on both sides of the bottom of the outer frame, so that the robot can achieve omnidirectional movement on a plane.

[0038] The robot follows the patient in all directions by using a wheel train consisting of four Mecanum wheels. The active weight-reducing unit can provide the patient with different weight-reducing forces on both sides of the body to compensate for gravity balance, and provide forward traction to improve the patient's walking gait. Combined with the angle measurement device, the robot system can adjust the weight-reducing force and traction applied to the patient in real time, and maintain a relative following state with the patient. This robot system allows patients to perform rehabilitation training in a normal walking state, and provides assistance for the different movement characteristics of the left and right sides of the human body, while providing forward assistance to improve gait.

[0039] The outer frame 1 is a U-shaped structure placed on its side, and is made by splicing or welding profiles. The bottom of the outer frame 1 is open to prevent the frame structure from interfering with the patient's normal walking; its rear side is convex to provide installation space for the control box 4.

[0040] As the posture of a person's body changes during walking, the posture of the traction rope 2 in space will also change accordingly. The traction rope 2 is inserted into the groove of the paddle 14, and the posture change of the traction rope 2 will drive the paddle 14 and the second fixing seat 12 to rotate around the axis B and the axis A respectively, so that the posture angle of the traction rope 2 in space is calculated in real time through the angle sensor 1 10 and the angle sensor 2 13.

[0041] according to Figure 5 As shown in the figure, since the traction rope 2 presents a certain angle in space, its pulling force F can be decomposed into a vertical upward weight-reducing force Fz, a forward traction force Fx and a lateral pulling force Fy. Since the two active weight-reducing units are symmetrically installed on the top of the outer frame 1, the traction ropes on the left and right sides can provide a vertical upward weight-reducing force Fz and a forward traction force Fx, respectively. 右 With Fz 左 , forward traction Fx 右 With Fx 左 , and the lateral tension Fy 右 With Fy 左 Through the chassis movement of the omnidirectional mobile unit and the output adjustment of the drive motor 18, Fy 右 With Fy 左 They offset each other, thus avoiding the influence of lateral force during the patient's walking rehabilitation.

[0042] Reference Figure 1 and Figure 2 The omnidirectional mobile unit is composed of four Mecanum wheel trains, which are directly fixed to the two side beams at the bottom of the outer frame 1. Each Mecanum wheel train includes a Mecanum wheel 5, a chassis motor 6 and a wheel train bracket; the wheel train bracket is fixed to the two side beams at the bottom of the outer frame 1, and the four Mecanum wheels 5 are rotatably arranged on the wheel train bracket. The chassis motor 6 is installed on the wheel train bracket, and its output end is coaxially fixedly connected to the wheel axle of the Mecanum wheel 5.

[0043] like Figure 1 and Figure 2 The binding device includes a rope fixing ring 7 and a binding belt 3; the binding belt 3 is fixed around the shoulder and chest to tightly fix the binding device to the patient's chest, the rope fixing ring 7 is fixed on the binding belt 3 and located at the shoulder of the binding belt 3, the traction rope 2 is connected to the rope fixing ring 7, and the weight reduction force and traction force are applied to the person through the binding belt 3. The binding device directly changes the patient's upper body posture, provides a guiding effect, adjusts the patient's center of gravity distribution, and improves the patient's walking gait.

[0044] In view of the above robot system, in order to achieve the goal of walking rehabilitation function training for patients. This embodiment provides a walking rehabilitation training motion control method, referring to Figure 7, F is the rope tension value read from the light tension sensor, the tension sensor is set between the traction rope 2 and the rope fixing ring 7, u is the control input signal of the motor, Z is the feedforward gain, F d represents the observed value of the system disturbance.

[0045] Establish a control strategy that includes:

[0046] S1. Establish a disturbance observer, which is used to observe the disturbances generated by humans / environment in the robot system and the unmodeled high-order quantities of the system, and compensate them in real time;

[0047]

[0048] Among them, τ L represents the traction torque, τ L =F·r / J, F is the measured value of the force sensor, l is the rope length, B is the motor viscous resistance coefficient, τ is the motor driving torque, J is the motor moment of inertia, θ is the motor rotation angle, and r is the radius of the pulley. The disturbance observer obtains the disturbance generated by humans or the environment and the unmodeled error of the system;

[0049] S2. Constructing the kinetic equation For the angular velocity and angular acceleration The positive feedback gain is used to compensate for the mechanical impedance (including inertia and damping) of the system to further accelerate the system response and improve the force control accuracy. B is the motor viscous resistance coefficient, J is the motor moment of inertia, and θ is the motor rotation angle;

[0050] S3. Design a PID controller to achieve further tracking control of the force. The feedforward coefficient Z is used to accelerate the system response, suppress load disturbances, and improve the convergence speed of the system. The feedforward coefficient Z is determined by the system parameters, and the PID feedback parameters are manually adjusted in the static experiment;

[0051]

[0052] u(t) is the output of the PID controller, K p is the proportionality coefficient, T i is the integration time constant, T d is the differential time constant, e(t) is the difference between the desired tracking force trajectory and the actual output force of the system;

[0053] The upper computer sends out the desired force trajectory to drive the robot to move, the drive motor 18 starts to drive the person to move, the angle encoder 10 and the angle encoder 2 13 and the force sensor detect the angle change information and tension information of the traction rope 2, and the tension information is input into the PID controller as feedback. The angle information and the tension information are both input into the disturbance observer to estimate the human-machine interaction disturbance and the unmodeled error of the system, and are input into the robot system again as the correction amount of the PID controller. The iterative cycle is carried out to achieve the human-machine interaction force actually output by the robot accurately following the desired trajectory, and the error between the human-machine interaction force actually output by the robot and the desired trajectory is kept within 5%.

[0054] The omnidirectional mobile unit composed of four Mecanum wheels 5 can realize forward movement, lateral movement, oblique movement, rotation and their combination without changing the direction of the robot, thus realizing omnidirectional movement. Therefore, it can meet the walking conditions of patients in any direction and any posture. The above control strategy can make corresponding movements according to the change of the angle measured by the angle sensor 10 and the angle sensor 2 13, so as to ensure that the angle of the traction rope 2 in space remains unchanged, that is, the magnitude of the weight reduction force and the traction force does not change during the patient's walking process. Figure 6 shown.

[0055] The disturbance interferer and PID controller in the above control strategy are integrated into the control box 4. The control box 4 controls the movement of each component according to the collected signals to realize the training of the walking rehabilitation function for the user.

[0056] The present application has been disclosed as above with preferred implementation cases, but it is not intended to limit the present application. Any technician familiar with the profession can make slight changes or modifications to the above-disclosed structures and technical contents without departing from the scope of the technical solution of the present application, and the equivalent implementation cases with equivalent changes are still within the scope of the technical solution of the present application.

Claims

1. A flexible-driven walking rehabilitation training robot system, characterized in that: It comprises an outer frame (1), an active weight reduction unit and an omnidirectional movement unit; The active weight reduction unit has two sets symmetrically distributed and installed on the upper cross beams on both sides of the outer frame. Each active weight reduction unit comprises a spatial angle measuring device (8), a traction rope (2) and a driving device. One end of the traction rope (2) is fixed to the driving device. The traction rope (2) passes through the angle measuring device (8). The other end of the traction rope (2) is used to be fixed to the shoulder binding device. The traction rope (2) is controlled by the driving device to provide a vertical upward weight reduction force and a forward traction force for the human body. The angle measuring device (8) comprises a pulley (9), an angle sensor 1 (10), a fixing seat 1 (11), a fixing seat 2 (12), an angle sensor 2 (13) and a paddle (14); the fixing seat 1 (11) is rotatably arranged on the outer frame (1), the angle sensor 1 (10) is fixed on the fixing seat 1 (11), the output shaft of the angle encoder 1 (10) is connected to the rotating shaft of the fixing seat 2 (12), the pulley (9) is rotatably arranged in the groove 1 of the fixing seat 2 (12), the paddle (14) is fixed in the groove 2 of the fixing seat 2 (12), the angle sensor (13) is fixed on the fixing seat 2 (12), the output shaft of the angle sensor 2 (13) is connected to the rotating shaft of the paddle (14), and the traction rope (2) is placed on the pulley (9) and passes through the paddle (14). 14); the angle sensor 1 (10) is used to measure the rotation angle of the fixing seat 2 (12) around the axis A; the paddle (14) rotates around the axis B as the traction rope rotates; the angle sensor 2 (13) is used to measure the rotation angle of the paddle (14) around the axis B; the driving device comprises a winding drum (16), a motor seat (17) and a driving motor (18); the traction rope (2) is wound around the winding drum (16), one end of the traction rope (2) is fixed to the winding drum (16), the motor seat (17) is fixed to the top cross beam of the outer frame (1), the driving motor (18) is fixed to the motor seat (17), the output shaft of the driving motor (18) is fixed to the rotating shaft of the winding drum (16), and the winding drum (16) is rotatably arranged on the motor seat (17); The omnidirectional mobile unit is composed of four Mecanum wheel trains, which are fixed on the cross beams on both sides of the bottom of the outer frame, so that the robot can achieve omnidirectional movement on a plane.

2. A flexible-driven walking rehabilitation training robot system according to claim 1, characterized in that: The binding device comprises a rope fixing ring (7) and a binding belt (3); the binding belt (3) is bound and fixed around the shoulders and chest, the rope fixing ring (7) is fixed on the binding belt (3) and is located at the shoulder of the binding belt (3), the traction rope (2) is connected to the rope fixing ring (7), and a weight reduction force and a traction force are applied to the person through the binding belt (3).

3. The flexible-driven walking rehabilitation training robot system according to claim 1, characterized in that: Each Mecanum wheel train comprises a Mecanum wheel (5), a chassis motor (6) and a wheel train bracket; the wheel train bracket is fixed to the cross beams on both sides of the bottom of the outer frame (1); four Mecanum wheels (5) are rotatably arranged on the wheel train bracket; the chassis motor (6) is installed on the wheel train bracket, and its output end is coaxially fixedly connected to the wheel axle of the Mecanum wheel (5).

4. The flexible-driven walking rehabilitation training robot system according to claim 1, characterized in that: The outer frame 1 is a sideways U-shaped structure, which is made by splicing or welding profiles.

5. A walking rehabilitation training motion control method, characterized in that: Based on the walking rehabilitation training robot system according to any one of claims 1 to 4, the control method comprises: S1. Establish a disturbance observer Among them, τ L represents the traction torque, τ L =F·r / J, F is the measured value of the force sensor, l is the rope length, B is the motor viscous resistance coefficient, τ is the motor driving torque, J is the motor moment of inertia, θ is the motor rotation angle, and r is the radius of the pulley. The disturbance observer obtains the disturbance generated by humans or the environment and the unmodeled error of the system; S2. Constructing the kinetic equation For the angular velocity and angular acceleration The positive feedback gain is used to compensate the mechanical impedance of the system; S3. Design PID controller u(t) is the output of the PID controller, K p is the proportionality coefficient, T i is the integration time constant, T d is the differential time constant, e(t) is the difference between the desired tracking force trajectory and the actual output force of the system; The upper computer sends out a desired force trajectory to drive the robot to move, the drive motor (18) starts to drive the person to move, the angle encoder 1 (10) and the angle encoder 2 (13) and the force sensor detect the angle change information and tension information of the traction rope (2), and the tension information is input into the PID controller as feedback. The angle information and the tension information are both input into the disturbance observer to estimate the human-machine interaction disturbance and the unmodeled error of the system, and are input into the robot system again as the correction amount of the PID controller. The iterative cycle is carried out to achieve that the human-machine interaction force actually output by the robot accurately follows the desired trajectory.

6. A walking rehabilitation training motion control method, characterized in that: The error between the human-machine interaction force actually output by the robot and the expected trajectory is controlled within 5%.

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