KR101321791B1 - Robot Motion Control System and Method for Active Body Rehabilitation - Google Patents

Abstract

The present invention relates to a robot motion control system and control method that can reflect the patient's will in the rehabilitation exercise. To this end, the robot motion control system according to an embodiment of the present invention is a robot module attached to the body part of the user, a target trajectory generation module for generating a target trajectory from the current position of the robot module to the target position, and the target trajectory generation The motion controller includes a motion controller for rehabilitation training of a user's body part by operating the robot module according to the target trajectory generated by the module, and the motion controller calculates a virtual force based on the target trajectory as a reference input, and calculates a virtual force value. It may be a virtual force-based motion controller that is applied to the robot module to control the motion of the robot module to follow the target trajectory.

Description

Robot Motion Control System and Method for Active Body Rehabilitation

The present invention relates to a robot motion control system and control method for enhancing the rehabilitation effect of the body rehabilitation system. More particularly, the present invention relates to a motion control system and a control method of an exoskeleton robot that can reflect the patient's will in a rehabilitation exercise.

Recently, due to the increase in the elderly population, patients with degenerative diseases such as stroke, dementia and Parkinson's disease are increasing. In particular, the sequelae of stroke, a representative senile brain disease, causes severe motor and cognitive impairment and seriously impairs the quality of life.

Recently, a new rehabilitation treatment system has been developed to overcome such sequelae and lead a healthy life as before. However, the developed lower extremity exercise rehabilitation system is not far from the passive, simple repetitive rehabilitation method. Such a rehabilitation method is known to be difficult to steadily rehabilitation treatment due to the low response to the rehabilitation treatment of patients, it is known that the rehabilitation treatment falls because the concentration to participate in rehabilitation training is dropped. In order to overcome this problem, the development of a rehabilitation treatment system has been actively developed to reflect the patient's intention to move in rehabilitation training to enhance the rehabilitation effect.

However, in the case of Korean Patent No. 10-0795195, there is a limitation that only the body part of the patient can be moved in a planned path, but does not reflect the will according to the movement of the patient.

Korea Patent Registration No. 10-0795195

SUMMARY OF THE INVENTION The present invention has been made to solve the problems described above, and an object thereof is to provide a motion control system and a control method of a robot that can reflect the intention to move the patient's intention measured by the sensor in the rehabilitation training.

To this end, a robot motion control system according to an embodiment of the present invention includes a robot module attached to a body part of a user, a target trajectory generation module for generating a target trajectory from a current position to a target position of the robot module, and A target controller for generating a rehabilitation training of the user's body part by operating the robot module according to the target trajectory, wherein the motion controller calculates a virtual force based on the target trajectory as a reference input; And a virtual force-based motion controller which controls the motion of the robot module to follow the target trajectory by applying the virtual force value to the robot module.

In this case, the motion controller may be a virtual spring-damper force controller for applying a virtual spring-damper force value to the robot module, and the virtual spring-damper force controller may be attached to a joint or a distal end of the robot module. .

In addition, the motion control system of the robot according to an embodiment of the present invention further includes a force / torque sensor attached to the robot module to measure external force, and when the external force is measured at the force / torque sensor, the motion controller The robot module may be additionally assigned to the robot module so that the robot module operates in compliance with the external force.

를 곱하여 상기 로봇 모듈에 추가로 부여함으로써, 상기 외력에 순응하는 정도를 조절할 수 있다.Further, the motion controller weights the value of the measured external force.

By multiplying and giving the robot module further, the degree of compliance with the external force can be adjusted.

In addition, the robot motion control method according to an embodiment of the present invention comprises the steps of generating a target trajectory from the current position of the robot module attached to the user's body part to the target position, and virtually by using the target trajectory as a reference input By calculating the force of the, and by applying the calculated virtual force value to the robot module to control the robot module to follow the target trajectory can be rehabilitation training of the body part of the user.

In this case, the virtual force may be a virtual spring-damper force.

In addition, the robot motion control method according to an embodiment of the present invention, the step of measuring the external force using a force / torque sensor attached to the robot module, and the value of the external force measured by the force / torque sensor the robot In addition to the module, it may further comprise the step of controlling the robot module to operate in compliance with the external force.

를 곱하여 상기 로봇 모듈에 추가로 부여함으로써, 상기 외력에 순응하는 정도를 조절하는 단계를 포함할 수 있다.In this case, controlling the robot module to operate in compliance with the external force may include a weighted value of the measured external force.

By multiplying and giving additionally to the robot module, it may include adjusting the degree of compliance with the external force.

According to the robot motion control system and control method according to the present invention, the motion is controlled by reflecting the force generated by the patient's will, not the method of unilaterally applying the motion to the patient, thereby increasing the concentration of the patient and actively rehabilitation. Induce them to participate in training.

In addition, according to the robot motion control system and control method according to the present invention, by using a virtual dynamic model to control the operation of the exoskeleton-type robot to control the robot using only the encoder without having to attach a torque or current sensor to each joint Not only can this be done, but it also simplifies the control algorithm because it does not have to take into account non-linear elements including gravity, friction, and the like.

1 is a schematic configuration diagram of a motion control system of a robot according to an embodiment of the present invention.
2 is a conceptual diagram illustrating the operation of the robot motion control system according to an embodiment of the present invention.
3 is a diagram illustrating a virtual dynamics model of a robot according to an embodiment of the present invention.
4 is a diagram illustrating a virtual dynamics model simulator of a robot according to an embodiment of the present invention.
5 is a diagram illustrating a target walking trajectory and a current trajectory of the robot when no external force is applied in the x-axis direction and the z-axis direction.
6 is a diagram illustrating a target walking trajectory and a current trajectory of the robot when no external force is applied in the xz plane.
7 is a diagram illustrating a target walking trajectory and a current trajectory of the robot when an external force is applied in the x-axis direction and the z-axis direction.
8 is a diagram illustrating a target walking trajectory and a current trajectory of the robot when an external force is applied in the xz plane.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. However, the accompanying drawings and the following description are only possible embodiments of the robot control system and control method according to the present invention, and the technical idea of the present invention is not limited to the following.

The sequelae of stroke, a representative senile brain disease, causes severe motor and cognitive impairment. In particular, lower paraplegia due to stroke may cause discomfort in daily life by deteriorating gait function, and in the long run, may cause body posture and abnormal muscle development. In order to overcome this gait disorder, recent researches related to rehabilitation of lower extremity exercise have been actively conducted.

The present invention relates to such a physical rehabilitation system, and proposes a motion control system and a control method of a robot that can actively perform rehabilitation training in consideration of the will of the patient.

1 is a schematic configuration diagram of a robot motion control system according to an embodiment of the present invention. Referring to FIG. 1, a robot motion control system according to an embodiment of the present invention includes a target trajectory generation module 12, a motion controller 14, a robot module 16, and a force / torque sensor 18. It is configured to include.

The robot module 16 corresponds to an exoskeleton-type robot platform attached to a body part such as an arm or a leg of a user (patient, etc.).

The target trajectory generation module 12 generates a target trajectory for controlling the movement of the robot module 16. That is, it serves to generate a trajectory from the current position of the robot module 16 to the target position.

The motion controller 14 enables the rehabilitation training of the body parts of the patient by operating the robot module 16 according to the target trajectory generated by the target trajectory generation module 12. Specifically, the motion controller 14 calculates a virtual force by using the target trajectory generated by the target trajectory generation module 12 as a reference input, and gives the robot module 16 the calculated virtual force value to the robot module 16. The motion of 16 may be a virtual force based motion controller that controls the motion of following the target trajectory.

The force / torque sensor 18 is attached to the robot module 16 and serves to measure external force. At this time, the external force is a concept including both the external force applied to the robot module 16 and the external force applied to the robot module 16 from the outside.

2 is a conceptual diagram illustrating the operation of the robot motion control system according to an embodiment of the present invention, Figure 3 is a diagram showing a virtual dynamics model of the robot according to an embodiment of the present invention.

는 목표 위치 벡터,

는 현재 위치 벡터,

는 목표 관절 벡터,

는 현재 관절 벡터,

는 힘/토크 센서에서 측정한 외력,

는 제어 토크를 각각 의미한다.2 conceptually illustrates how the motion controller 14 of the present invention controls the robot module 16 by generating a target joint vector in the robot module 16. As shown in FIG. 2, the robot motion control system according to the present invention uses a virtual spring-damper force to control a virtual kinematic model of the same kinematic and dynamic structure as the actual exoskeleton type robot module 16. 2,

Is the target position vector,

Is the current position vector,

Target joint vector,

Is the current joint vector,

Is the external force measured by the force / torque sensor,

Denotes the control torque, respectively.

3 shows the external force applied to the virtual dynamics model 31, the virtual spring-damper 33, and the virtual dynamics model 31 of the exoskeleton-type robot on the treadmill 35. That is, the patient is able to rehabilitation training in accordance with the operation of the robot module 16 after attaching the robot module 16 to the body part on the instrument such as the treadmill 35. The present invention proposes a rehabilitation training system that can adapt to external forces generated by a patient while using a virtual dynamics model during such rehabilitation training. Hereinafter, an operation control method using a virtual dynamic model will be described in detail with reference to FIGS. 2 and 3.

The equation of motion of the virtual dynamics model considering the external force can be expressed as follows.

는 가상 동역학 모델의 관절 벡터,

는 관성 메트릭스 (inertia matrix) 그리고

는 원심력 및 코리올리 벡터이다.At this time,

Joint vector of virtual dynamics model,

Is the inertia matrix and

Are centrifugal force and Coriolis vector.

는 제어 토크 벡터이고,

는 가상 동역학 모델에 작용하는 외력을 의미한다. 수학식 (1)에서 동작을 제어하기 위한 제어 토크,

는 다음과 같이 나타낼 수 있다. Here, since the equation of motion of the virtual dynamics model is modeled in the space defined by the user, nonlinear elements such as gravity terms and frictional forces can be excluded.

Is the control torque vector,

Is the external force acting on the virtual dynamics model. A control torque for controlling the operation in equation (1),

Can be expressed as follows.

는

번째 위치에 작용하는 가상 스프링-댐퍼에 의한 힘이고 (

는 예를 들어, 도3에서와 같이 고관절, 슬관절, 발목관절의 위치),

는 가상 스프링-댐퍼 힘의 개수이고,

는

번째 위치의 자코비안 행렬 (Jacobian matrix) 이고,

는 관절 댐핑 계수,

는 로봇의 관절들의 허용 각도를 제한하기 위한 가상 반력 토크이다.

와

는 각각 가상 스프링 계수와 댐핑 계수이고,

와

는 각각

번째 위치의 목표위치 벡터와 현재 위치 벡터이다.here

The

Force by the virtual spring-damper acting in the second position (

For example, the position of the hip joint, knee joint, ankle joint as shown in Figure 3),

Is the number of virtual spring-damper forces,

The

Is the Jacobian matrix at the first position,

The joint damping coefficient,

Is the virtual reaction torque to limit the allowable angle of the joints of the robot.

Wow

Are the virtual spring coefficients and the damping coefficients, respectively.

Wow

Respectively

The target position vector and the current position vector of the second position.

The current position of the virtual dynamics model can follow the target position by the virtual spring-damper force to control the motion along the given target trajectory. In this case, the 'target trajectory' means a walking trajectory of a normal person to which rehabilitation training for lower limbs can be applied.

는 다음 식과 같이 표현할 수 있다. In addition, in order to reflect the force generated by the will of the patient in the equation (1) to the motion controller 14, the external force measured through the force / torque sensor 18,

Can be expressed as

는 j번째 위치에 부착된 힘/토크 센서(18)에서 감지된 외력이고 (j 는 예를 들어, 도3에서와 같이 허벅지와 정강이의 위치), NOS는 외골격형 로봇 모듈(31)에 부착된 힘/토크 센서(18)의 개수이고,

는 j번째 위치의 자코비안 행렬 (Jacobian matrix) 이고, 가중치 값

는 환자의 의지에 의해 발생하는 외력의 크기를 조절하기 위한 계수이다. here

Is the external force sensed by the force / torque sensor 18 attached to the j-th position (j is the thigh and shin position as shown in FIG. 3, for example), and NOS is attached to the exoskeleton-type robot module 31 Number of force / torque sensors 18,

Is the Jacobian matrix at position j and the weight value

Is a coefficient for controlling the magnitude of external force generated by the will of the patient.

으로 설정 할 경우, 환자의 의지에 의해 발생하는 외력을 동작 제어기(14)에 반영하지 않는 의미이기 때문에 동작이 외골격형 로봇 모듈(31)에 의해 환자에게 일방적으로 가해지는 위치제어 모드로 설정될 것이고,

으로 설정 할 경우, 환자의 의지에 의해 발생하는 외력을 동작 제어기(14)에 100% 반영하게 된다. 따라서,

를 0 과 1 사이에 적절히 설정함으로써 환자의 상태에 따라서 환자의 의지를 재활 훈련에 반영할 수 있다. At this time,

If it is set to, since the external force generated by the patient's will is not reflected in the motion controller 14, the motion will be set to the position control mode in which the exoskeleton-type robot module 31 is unilaterally applied to the patient. ,

If set to, the external force generated by the will of the patient is reflected 100% to the motion controller (14). therefore,

By properly setting the value between 0 and 1, the patient's will can be reflected in the rehabilitation training according to the patient's condition.

By solving the static dynamics equations and numerical integration of the virtual dynamics model including equations (1), (2), (3), and (4), we can calculate joint acceleration, joint velocity, and joint position trajectory according to the current state. .

By using the joint position trajectory obtained through the virtual dynamics-based controller as shown in FIG. 3, each motor attached to the exoskeleton-type robot can be controlled to generate a movement required for rehabilitation training. By inputting the walking trajectory of a normal person as the target trajectory of the controller while the patient's leg is in contact with the exoskeleton type robot module 31, the patient may maintain a correct posture and perform rehabilitation training. In addition, the external force applied by the patient's will is detected by the force / torque sensor 18 attached to the thigh and the shin and reflected in the operation of the robot module 31 to induce the patient to actively participate in rehabilitation training. have.

Experiments were performed through a simulator for the verification of the motion controller 14 described above. 4 is a diagram illustrating a virtual dynamics model simulator of a robot according to an embodiment of the present invention. The simulator consists of a total of 5 degrees of freedom (waist: 1 degree of freedom, both legs: 2 degrees of freedom) and includes dynamics.

In Fig. 4, the target trajectories 43 and 45 of the knee joint and the ankle joint of the robot module 41 are shown in the shape of gray checkers, and the external force 1 and the external force 2 are displayed on the thigh and the shin in the shape of the checker hole. .

Here, the target trajectories 43 and 45 may be referred to as walking trajectories of normal people, and control the operation of the robot module 41 by causing the current position of the exoskeleton-type robot to follow the target trajectory by the virtual spring-damper force. External force is a force generated by the patient's will and can be detected through a force / torque sensor.

를 조절함으로써 환자의 의지에 의해 발생한 외력에 순응하는 정도를 제어함으로써, 능동적인 재활 훈련을 할 수 있도록 한다.
Referring to FIG. 4, the patient follows the position guided by the robot module 41 because no external force occurs in the right leg, but the external force occurs in the left leg and cannot follow the target trajectories 43 and 45. It can be seen that the position of the robot module 41 is pushed toward the front of the patient. That is, the present invention, as mentioned earlier, the weight value

By controlling the degree of compliance with external forces generated by the will of the patient, active rehabilitation training can be performed.

5 and 6 are diagrams showing the results of the experiment through the virtual dynamics model simulator.

FIG. 5 is a diagram showing the target walking trajectory (solid blue line) and the current trajectory of the robot module 16 (dotted red line) in the x-axis direction and the z-axis direction when no external force is applied, and FIG. The target walking trajectory (solid blue line) and the current trajectory (red dotted line) of the robot module 16 in the case of no support are shown in the xz plane. The y-axis direction was excluded because it showed little characteristic of the walking trajectory.

When the external force is 0 as shown in (c) of FIG. 5, it can be seen that the current trajectory of the robot module 16 follows the target trajectory as shown in FIGS. 5 (a), (b) and 6.

On the other hand, Figure 7 is a view showing the target walking trajectory (solid blue line) and the current trajectory (red dotted line) of the robot module 16 when the external force is applied in the x-axis direction and z-axis direction, Figure 8 is an external force The target walking trajectory (solid blue line) and the current trajectory (red dotted line) of the robot module 16 in the case of being applied are shown in the xz plane.

Referring to FIG. 7C, an external force may act between about 0.5 to 2 seconds and 3.5 to 5.1 seconds. In (a) and (b) of FIG. 7, it can be seen that the current trajectory of the robot module 16 greatly deviates from the target trajectory in the section where the external force is generated.

This is the result of the robot module 16 reacting according to the generation of external force while following the motion to the target trajectory. That is, when no external force is applied, when the current position of the robot module 16 follows the target trajectory and an external force is generated, the operation of the robot module 16 conforms accordingly. In addition, since the motion controller 14 of the present invention can adjust the degree of external force to be applied to the movement of the robot module 16, it can properly reflect the will according to the condition of the patient.

Although one embodiment of the present invention has been described above, the scope of the present invention is not limited thereto, and various modifications can be made within the scope of the claims, the detailed description of the invention, and the accompanying drawings. Naturally, this also belongs to the scope of the present invention.

12: target trajectory generation module 14: motion controller
14: robot module 16: robot module
18: Force / Torque Sensor

Claims (9)

A robot module attached to a body part of a user;
A target trajectory generation module for generating a target trajectory from a current position of the robot module to a target position; And
And a motion controller for rehabilitation training of the user's body part by operating the robot module according to the target trajectory generated by the target trajectory generation module.
A force / torque sensor attached to the robot module to measure external force;
The motion controller is configured to calculate a virtual force by using the target trajectory as a reference input, and to control the operation of the robot module to follow the target trajectory by applying the virtual force value to the robot module.
When the external force is measured by the force / torque sensor, the motion controller additionally gives the measured value of the external force to the robot module so that the robot module operates in compliance with the external force. system. The method of claim 1,
And the motion controller is a virtual spring-damper force controller that imparts a virtual spring-damper force value to the robot module. 3. The method of claim 2,
The virtual spring-damper force controller,
Robot motion control system, characterized in that attached to the joint or the distal end of the robot module. delete The method of claim 1,
The motion controller is weighted to the value of the measured external force

By multiplying and giving additionally to the robot module, the robot motion control system, characterized in that to adjust the degree of compliance with the external force. Generating a target trajectory from the current position of the robot module attached to the body part of the user to the target position;
Calculating a virtual force by using the target trajectory as a reference input, and controlling the robot module to follow the target trajectory by applying the calculated virtual force value to the robot module;
Measuring an external force using a force / torque sensor attached to the robot module; And
And additionally applying a value of the external force measured by the force / torque sensor to the robot module to control the robot module to operate in compliance with the external force. The method according to claim 6,
The virtual force is a virtual spring-damper force. delete The method according to claim 6,
Controlling the robot module to operate in compliance with the external force,
Weighted to the value of the measured external force

And multiplying the robot module to further adjust the degree of compliance with the external force.

Images