Flexible driven walking rehabilitation training robot system and motion control method

Abstract

A flexible driven walking rehabilitation training robot system and motion control method, the robot system contains an outer frame, a main active weight reduction unit and an omnidirectional movement unit; the control method is that the host computer issues the expected force trajectory to drive the robot action, the driving motor starts to drive the human motion, the angle encoder one and the angle encoder two detect the angle change information and the tension information of the traction rope, the tension information is input into the PID controller as feedback, the angle information and the tension information are 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, iterative circulation, the actual output of the robot accurately follows the expected trajectory. The application can meet the demand of active participation of patients, and provide quantitative and targeted walking training strategy, and realize the purpose of walking rehabilitation function training for patients.

Description

TECHNICAL FIELD

[0001] The present application relates to a rehabilitation robot, in particular to a flexible driving walking rehabilitation training robot system and a motion control method, and belongs to the technical field of robots. BACKGROUND

[0002] Scientific motion rehabilitation training has obvious improvement effect on improving the degradation of patient's motion learning ability and promoting the rehabilitation of patient's limb function. Among them, walking training is a common rehabilitation training method. Scientific walking training can provide sufficient motion stimulation information for patients, promote the reconstruction of patient's motion learning ability, and improve the patient's walking movement disorder.

[0003] In the traditional walking training, the rehabilitation therapist usually guides the patient to walk by hand or with the help of certain rehabilitation training equipment in one-to-one or even many-to-one mode. This training method is very dependent on the professional skills and personal experience of the rehabilitation therapist, and the rehabilitation therapist is difficult to timely optimize and adjust according to the training condition of the patient. At the same time, the above-mentioned patient often has unilateral functional disorder, and the rehabilitation therapist is difficult to apply quantitative and targeted rehabilitation assistance according to the different conditions of the two sides of the patient's body.

[0004] Reduced weight walking training can stimulate the active participation of patients and encourage them to actively control their gait and balance. It can independently provide a large amount of repetitive walking training for patients, relieve the pressure of rehabilitation therapists and make up for the defects caused by the shortage of rehabilitation therapists at the present stage.

[0005] The existing walking training weight reduction device usually allows the patient to walk on a treadmill, and the weight reduction device only provides weight reduction protection. The single weight reduction force can significantly change the ground reaction force when a person walks, and seriously affect the gait parameters, which can easily lead to gait fixation of the patient and cannot meet the needs of the patient's actual walking motion learning rehabilitation. At the same time, the existing walking training weight reduction device usually cannot apply assistance to the different motion 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 the gait. SUMMARY

[0006] The present application provides a flexible driving walking rehabilitation training robot system and a motion control method to overcome the shortcomings of the prior art. The robot system can apply different weight reduction forces to the two sides of the patient's body to protect the patient when walking on the actual road surface, and provide forward assistance to improve the gait. At the same time, it can meet the needs of the patient's active participation and provide quantitative and targeted walking training strategies.

[0007] A flexible driving walking rehabilitation training robot system, comprising an outer frame, an active weight reduction unit and an omnidirectional movement unit.

[0008] The active weight loss unit has two sets of symmetrical distribution, which are installed on the upper beams on both sides of the outer frame. Each active weight loss unit comprises a space angle measuring device, a traction rope and a driving device. One end of the traction rope is fixed on the driving device, the traction rope passes through the angle measuring device, and the other end of the traction rope is used for fixing on the binding device of the shoulder. The traction rope is controlled by the driving device to provide the vertical upward weight loss force and the forward traction force of the human body.

[0009] The angle measuring device comprises a pulley, an angle sensor one, a fixed seat one, a fixed seat two, an angle sensor two and a dial. The fixed seat one is rotatably arranged on the outer frame, the angle sensor one is fixed on the fixed seat one, the output shaft of the angle encoder one is connected with the rotating shaft of the fixed seat two, the pulley is rotatably arranged in the groove one of the fixed seat two, the dial is fixed in the groove two of the fixed seat two, the angle sensor is fixed on the fixed seat two, the output shaft of the angle sensor two is connected with the rotating shaft of the dial, and the traction rope is arranged on the pulley and passes through the rope hole of the dial. The angle sensor one is used for measuring the rotation angle of the fixed seat two around the axis A. The dial rotates around the axis B with the rotation of the traction rope. The angle sensor two is used for measuring the rotation angle of the dial around the axis B. The driving device comprises a winding disc, a motor seat and a driving motor. The traction rope is wound on the winding disc, one end of the traction rope is fixed on the winding disc, the motor seat is fixed on the top beam of the outer frame, the driving motor is fixed on the motor seat, the output shaft of the driving motor is fixed with the rotating shaft of the winding disc, and the winding disc is rotatably arranged on the motor seat.

[0010] The omnidirectional movement unit is composed of four Mecanum wheel systems, which are fixed on the two side beams at the bottom of the outer frame, so that the robot can realize omnidirectional movement on the plane.

[0011] A walking rehabilitation training motion control method is realized based on the above-mentioned walking rehabilitation training robot system. The control method comprises:

[0012] S1, establishing a disturbance observer

[0013]

[0014] Wherein, τ L represents the traction torque, τ L =F·r / J, F represents the measurement 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 rotational inertia, θ is the motor rotation angle, r is the radius of the pulley, is the disturbance generated by the human or the environment and the unmodeled error of the system obtained by the disturbance observer;

[0015] S2, constructing a dynamics equation for the angular velocity And angular acceleration The positive feedback gain compensates for 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 proportional coefficient, T i is the integral 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 the desired force trajectory to drive the robot action, and the motor is started to drive the human motion. The angle encoder and the angle encoder detect the angle change information and the tension information of the traction rope. The tension information is input into the PID controller as feedback. The angle information and the tension information are input into the disturbance observer to estimate the human-robot 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. Iterative cycle, realize the actual output of the robot human-robot interaction force accurate follow-up expected trajectory.

[0020] The beneficial effects of the present application compared with the prior art are:

[0021] The application utilizes the omnidirectional mobile unit to follow the omnidirectional movement of the human, utilizes the active weight reduction unit to realize the gravity balance compensation of providing different weight reduction forces on both sides of the patient, and simultaneously provides forward traction force to improve the walking gait of the patient. The angle measuring device enables the robot to change the weight reduction force and the traction force applied to the patient at any time, and enables the robot to keep relative following with the patient.

[0022] The control strategy design can provide corresponding assistance in the forward direction to improve the gait and apply assistance to the motion characteristics, so as to realize the goal of walking rehabilitation function training of the patient.

[0023] The technical solutions of the present application will be further described below in combination with the drawings and examples: DRAWINGS

[0024] Figure 1 is a schematic view of the flexible driving walking rehabilitation training robot system of the present application;

[0025] Figure 2 is a front view of the flexible driving walking rehabilitation training robot system of the present application;

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

[0027] Figure 4 is the front view of the active weight loss unit of the present application;

[0028] Wherein, 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, fixed seat 1, 12, fixed seat 2, 13, angle encoder 2, 14, dial, 15, coupling, 16, reel, 17, motor base, 18, drive motor;

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

[0030] Figure 6 is the robot system omni-directional movement logic diagram of the present application;

[0031] Figure 7 is the gait rehabilitation training motion control block diagram of the present application. DETAILED DESCRIPTION

[0032] The embodiments of the technical solutions of the present application will be described in detail below with reference to the accompanying drawings. Unless otherwise specified, the technical terms or scientific terms used in the present application are the commonly understood meanings by the skilled in the art.

[0033] Referring to Figures 1-4 , a flexible driven gait rehabilitation training robot system of the embodiment comprises an outer frame 1, an active weight loss unit and an omni-directional movement unit.

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

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

[0036] With reference to Figure 3 and Figure 4 The driving device comprises a winding disc 16, a motor seat 17 and a driving motor 18. The traction rope 2 is wound on the winding disc 16, one end of the traction rope 2 is fixed on the winding disc 16, the traction rope 2 is always in a straight state, and the traction ropes 2 on the left and right sides jointly provide the vertical upward weight-reducing force and the forward traction force acting on the human body. The motor seat 17 is fixed on the top beam 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 with the rotating shaft of the winding disc 16, and the winding disc 16 is rotatably arranged on the motor seat 17.

[0037] The omnidirectional moving unit is composed of four Mecanum wheel systems, and the four Mecanum wheel systems are fixed on the bottom beams on both sides of the outer frame, so that the robot can realize omnidirectional movement on a plane.

[0038] The robot follows the patient by the four Mecanum wheel systems. The active weight-reducing unit can provide different weight-reducing forces on the left and right sides of the patient to compensate for the gravity balance, and provide a forward traction force to improve the walking gait of the patient. In combination with the angle measuring device, the robot system can adjust the weight-reducing force and the traction force applied to the patient in real time, and maintain the relative following state with the patient. The robot system can enable the patient to perform rehabilitation training in a normal walking state, apply assistance according to the different movement characteristics of the left and right sides of the human body, and provide forward assistance to improve the gait.

[0039] The outer frame 1 is a side-laying U-shaped structure, which is made by profile splicing or welding. The bottom of the outer frame 1 is in an open state to avoid interference of the frame structure with the normal walking of the patient; and the rear side is outwardly convex to provide a mounting space for the control box 4.

[0040] Because the body posture of the person is constantly changing during walking, the posture of the traction rope 2 in space will also change. The traction rope 2 is clamped by the groove of the paddle 14, and the posture change of the traction rope 2 will drive the paddle 14 and the fixed seat 12 to rotate around the axis B and the axis A respectively, so as to calculate the posture angle of the traction rope 2 in space in real time through the angle sensor 10 and the angle sensor 13.

[0041] According to Figure 5 As shown in the figure, because the traction rope 2 presents a certain angle in space, its pulling force F can be decomposed into the vertical upward weight-reducing force Fz, the forward traction force Fx, and the lateral pulling force Fy. Because the two active weight-reducing units are symmetrically installed on the top of the outer frame 1, the left and right traction ropes can respectively provide the vertical upward weight-reducing force Fz 右 and Fz 左 , the forward traction force Fx 右 and Fx 左 , and the lateral pulling force Fy 右 and Fy 左 . Through the chassis movement of the omnidirectional movement unit and the output adjustment of the drive motor 18, Fy 右 and Fy 左 can be counteracted, so as to avoid the influence of the lateral force during the walking rehabilitation of the patient.

[0042] Referring to Figure 1 and Figure 2 , the omnidirectional movement unit is composed of four Mecanum wheel systems and is directly fixed to the bottom beams of the outer frame 1. Each Mecanum wheel system includes a Mecanum wheel 5, a chassis motor 6, and a wheel system bracket; the wheel system bracket is fixed to the bottom beams of the outer frame 1, the four Mecanum wheels 5 are rotatably arranged on the wheel system bracket, and the chassis motor 6 is installed on the wheel system bracket and is coaxially and fixedly connected to the wheel shaft of the Mecanum wheel 5.

[0043] As 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 the chest to tightly fix the binding device to the chest part of the patient, the rope fixing ring 7 is fixed on the binding belt 3 and located at the shoulder part of the binding belt 3, and the traction rope 2 is connected to the rope fixing ring 7 to apply the weight-reducing force and the traction force to the person through the binding belt 3. The binding device provides a guiding effect by directly changing the posture of the upper body of the patient, adjusts the center of gravity distribution of the patient, and improves the walking gait of the patient.

[0044] In the face of the above robot system, in order to achieve the goal of walking rehabilitation function training for the patient. The embodiment provides a walking rehabilitation training motion control method, referring to Figure 7, F is the value of the rope tension read from the light tension sensor, the tension sensor is arranged 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 observation value of the system disturbance.

[0045] The control strategy is established, which comprises:

[0046] S1, a disturbance observer is established, which is used to observe the disturbance generated by the human / environment in the robot system and the unmodeled high-order quantity of the system and compensate in real time;

[0047]

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

[0049] S2, the dynamic equation is constructed for further accelerating the system response and improving the force control accuracy by the positive feedback gain of angular velocity and angular acceleration . B is the viscous resistance coefficient of the motor, J is the moment of inertia of the motor, and θ is the rotation angle of the motor;

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

[0051]

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

[0053] The host computer sends the desired force trajectory to drive the robot action, and the motor 18 is started to drive the human motion. The angle encoder 10 and the angle encoder 13 detect the angle change information and the tension information of the traction rope 2. The tension information is input as feedback into the PID controller, and the angle information and the tension information are input into the disturbance observer to estimate the human-robot interaction disturbance and the unmodeled error of the system, and are input again into the robot system as the correction amount of the PID controller. The iteration cycle is realized to realize the accurate following of the desired trajectory of the actual output of the human-robot interaction force of the robot, and the error between the actual output of the human-robot interaction force of the robot and the desired trajectory is controlled within 5%.

[0054] The omni-directional mobile unit composed of four Mecanum wheels 5 can realize forward movement, transverse movement, oblique movement, rotation and their combinations without changing the orientation of the robot, and realizes omni-directional movement. Therefore, the walking condition of the patient in any direction and any posture can be met. The above control strategy can perform corresponding movement according to the change of the angle measured by the angle sensor 10 and the angle sensor 13, so as to ensure that the included angle of the traction rope 2 in space is always unchanged, that is, the size of the weight reduction force and the traction force does not change during the walking process of the patient, as shown in Figure 6

[0055] The disturbance observer and the PID controller in the above control strategy are integrated in 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 of the user.

[0056] The above has disclosed the preferred embodiments of the present application, but is not used to limit the present application. Any person skilled in the art can make some changes or modifications to the above disclosed structure and technical content without departing from the scope of the technical solutions of the present application, and the equivalent embodiments with equivalent changes are still within the scope of the technical solutions of the present application.​

Claims

1. A flexible driven walking rehabilitation training robot system, characterized in that: The application relates to a robot, which comprises an outer frame (1), an active weight-reducing unit and an omni-directional moving unit. The active weight-reducing unit is symmetrically arranged in two sets and is arranged on the upper cross beams on the two sides of the outer frame; each active weight-reducing unit comprises a space angle measuring device (8), a traction rope (2) and a driving device; one end of the traction rope (2) is fixed on the driving device, the traction rope (2) passes through the angle measuring device (8), and the other end of the traction rope (2) is used for fixing on a binding device on the shoulder; the traction rope (2) is controlled by the driving device to provide a vertical upward weight-reducing force and a forward traction force. The angle measuring device (8) comprises a pulley (9), an angle sensor one (10), a fixed seat one (11), a fixed seat two (12), an angle sensor two (13) and a shifting piece (14); the fixed seat one (11) is rotatably arranged on the outer frame (1), the angle sensor one (10) is fixed on the fixed seat one (11), the output shaft of the angle sensor one (10) is connected with the rotating shaft of the fixed seat two (12), the pulley (9) is rotatably arranged in a groove one of the fixed seat two (12), the shifting piece (14) is fixed in a groove two of the fixed seat two (12), the angle sensor two (13) is fixed on the fixed seat two (12), the output shaft of the angle sensor two (13) is connected with the rotating shaft of the shifting piece (14), and the traction rope (2) is arranged on the pulley (9) and passes through a rope hole of the shifting piece (14); the angle sensor one (10) is used for measuring the rotating angle of the fixed seat two (12) around the axis A; the shifting piece (14) rotates around the axis B along with the rotation of the traction rope; the angle sensor two (13) is used for measuring the rotating angle of the shifting piece (14) around the axis B; the driving device comprises a winding disc (16), a motor base (17) and a driving motor (18); the traction rope (2) is wound on the winding disc (16), one end of the traction rope (2) is fixed on the winding disc (16), the motor base (17) is fixed on the top cross beam of the outer frame (1), the driving motor (18) is fixed on the motor base (17), the output shaft of the driving motor (18) is fixed with the rotating shaft of the winding disc (16), and the winding disc (16) is rotatably arranged on the motor base (17). The omni-directional moving unit is composed of four Mecanum wheel systems, the four Mecanum wheel systems are fixed on the bottom cross beams on the two sides of the outer frame, so that the robot can realize omni-directional movement on a plane. The disturbance disturber and the PID controller are integrated in a control box (4), the control box (4) controls the movement of each component according to the collected signals, and the control method comprises the following steps: S1, establishing a disturbance observer where τ L represents the traction torque, τ L = F· r / J, F represents 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 rotational inertia, is the motor rotation angle, r is the radius of the pulley, is the disturbance observed by the disturbance observer, which is generated by the human or the environment and the unmodeled error of the system; S2, construct the kinetic equation for compensating the mechanical impedance of the system by the positive feedback gain of the angular velocity and the angular acceleration ; S3, designing a PID controller u(t) is the output of the PID controller, K p is the proportional coefficient, T i is the integral time constant, T d is the derivative time constant, e(t) is the difference between the desired trajectory of the force and the actual output force of the system; The host computer sends a desired force trajectory to drive the robot to act, and the motor (18) is started to drive the human motion, the angle encoder one (10) and the angle encoder two (13) and the force sensor detect the angle change information and the tension information of the traction rope (2), the tension information is input into the PID controller as feedback, the angle information and the tension information are input into the disturbance observer to estimate the human-robot 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, and the iteration is repeated to realize the accurate following of the desired trajectory of the actual output of the robot. 2.The 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 fixed around the shoulder and the 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 with the rope fixing ring (7), and the binding belt (3) is used to apply the weight-reducing force and the traction force to the human. 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 train support; the train support is fixed on the bottom side beams of the outer frame (1), the four Mecanum wheels (5) are rotatably arranged on the train support, and the chassis motor (6) is installed on the train support and coaxially fixed with the wheel shaft 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 U-shaped structure laid on the side and made of profiled sections spliced or welded.

5. The flexible driven walking rehabilitation training robot system according to claim 1, characterized in that: The error between the actual output of the robot and the desired trajectory of the human-robot interaction force is controlled within 5%.

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