KR20050041133A - Walking training support robot with the distributed control of pneumatic actuator - Google Patents

Abstract

A pneumatic dispersion control type walking assistance robot is disclosed. The present invention provides weight distribution means for distributing the user's weight in symmetrical directions; A left load sensing means and a right load sensing means for sensing the distributed load degree respectively; Weight deloading means coupled to the weight distributing means to deload the user's weight in response to the degree of load; And a load buffer means coupled to the weight deloading means and configured to perform buffering in response to respective signals output from the left load sensing means and the right load sensing means when the user moves. According to the present invention, by training the patient similar to the actual gait can correct the asymmetric gait of the patient it is possible to more effective rehabilitation. In addition, by simplifying the structure by forming the pneumatic and the robot arm integrally, it is possible to remove the element of the pressure to the user. And since it is possible to move, it can be fully utilized as a means of transportation for the elderly, including rehabilitation.

Description

Walking Training Support Robot with the distributed control of Pneumatic actuator}

The present invention relates to a pneumatic distributed control type walking assistance robot, and more particularly, to a pneumatic distributed control type walking assistance robot that performs distributed control according to left and right walking patterns, respectively, in order to perform rehabilitation according to the actual walking pattern.

Older people have difficulty in walking due to weakening of muscle strength and bone strength, and there is a problem such as not being able to find their home even in a near area near the house if there is dementia. On the other hand, disabled people need training courses such as physical therapy during initial rehabilitation due to weakening of muscle strength during the treatment of damage to the nervous system and long-term fractures caused by various accidents. In these rehabilitation programs, intelligent robotic systems are needed to assist walking, to ensure the safety of the trainees, and to move short distances to indoors as well as outdoors. The rehabilitation process is time consuming and requires the weight of the trainees to be reduced. Therefore, the introduction of the robot system is essential.

For this purpose, the walk assisted robot system was developed. However, the walk assisted robot system adopts a pneumatic system in the center to control the gait in providing weight deloading function. This is a problem of rehabilitation in the form of rehabilitation of the lower body disabled people with different injuries, different from the actual walking pattern after rehabilitation training. In addition, in the walking assisted robot system, the positional relationship between the robot arm and the pneumatic compressor not only gives the patient a sense of pressure, but also makes it difficult to easily adapt to the height of the patient.

Accordingly, an object of the present invention is to simplify the structure of the system by integrating the robot arm and the pneumatic actuator as well as performing distributed control according to the left and right walking patterns, respectively, in order to perform rehabilitation according to the actual walking pattern. In addition, the present invention provides a pneumatic distributed control type walking assistance robot that easily adapts to a user's height and moves freely in space.

Specifically, the object of the present invention is to provide a pneumatic dispersion control type walking aid robot.

1. In rehabilitation training of the lower body with different injuries on the left and right sides, distributed control for each of the left and right sides so that the rehabilitation training is similar to the actual walking pattern

2. In the design of the pneumatic distributed control walking assistance robot, the robot arm and the pneumatic body are integrated to reduce the weight of the patient.

3. Designed to change the height of the robot to adapt to the height of the patient by integrating the robot arm and the pneumatic

4. Designed to be mobile so that the training space can be moved freely by providing a means

5. Ensure autonomy of movement by providing sensing means to grasp the movement of patients during movement

Pneumatic dispersion control walking aid robot for achieving the above object of the present invention, the weight distribution means for distributing the user's weight symmetrically; A left load sensing means and a right load sensing means for sensing the distributed load degree respectively; Weight deloading means coupled to the weight distributing means to deload the user's weight in response to the degree of load; And a load buffer means coupled to the weight deloading means and configured to perform buffering in response to respective signals output from the left load sensing means and the right load sensing means when the user moves.

At this time, the present invention is formed by further forming a direction detecting means for detecting the user's moving direction to follow the user's movement path. The direction detecting means may include an ultrasonic sensor or a camera for detecting a user's movement; And a left moving motor and a right moving motor respectively controlled in response to the signal analysis input from the ultrasonic sensor or the camera. Here, the left load sensing means and the right load on the rotation axis of the user to continuously perform the unloading function of the user through the load buffer means using the data of every moment measured from the left load sensing means and the right load sensing means. The sensing means is formed.

On the other hand, the weight de-loading means, the left motor and the right motor to prevent the reverse rotation when the load is made and the load is made to de-load the user's weight; And a link bar having one end gear coupled to each of the left motor and the right motor and the other end hinged to the load buffering means for lifting and lowering the load buffering means.

The left sensing means and the right sensing means use a load cell, and the load buffer means uses a pneumatic cylinder.

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of the present invention.

In the description of the present invention, the same reference numerals will be given to components that perform the same function. In consideration of the fact that the robot of the present invention is formed in a symmetrical form, the terms “left” and “right” are distinguished in terms of configuration and operation in front of a corresponding component name.

1 is a perspective view of a pneumatic dispersion control type walking assistance robot according to an embodiment of the present invention. Referring to Figure 1, the pneumatic dispersion controlled walking aid robot of the present invention is large, the upper part for unloading the weight of the patient, the middle part that can change the height of the system to the height of the patient, and to move the space It is composed of a designed lower part.

For ease of explanation, it will be described sequentially from the bottom to the top direction.

First, the lower portion is provided with moving means to the left and right sides of the patient. The moving means covers its exterior with a housing 1, and a moving motor 3 is mounted inside the housing 1. The wheel 5 which rotates in the forward / reverse direction by this moving motor 3 is fastened. Rotation in the forward / reverse direction of the moving motors 3 provided on both sides enables free movement such as straightness and rotation. In front of the patient, a battery 7 and a pneumatic pump 9 housed in a case (not shown) are provided. The battery 7 and the pneumatic pump 9 are provided on the board 11, and a rotary wheel 13 is formed below the board 11. In this way, the lower part is composed of a basic system for movement by the wheel 5 and the rotary wheel 13 fastened to the moving means.

A plate-shaped vertical column 15 is coupled to an upper portion of the housing 1 for accommodating the moving motor 3. The height of the vertical column 15 is set to be used by a plurality of patients having different heights. It is preferable to set it to reflect approximately the height of the wheelchair of the patient. This is to provide a convenience in use as well as to facilitate the movement from the wheelchair to the pneumatic dispersion control walking aid robot of the present invention. On the other hand, a vertical motor 17 and a gear box 19 are mounted inside the upper portion of the vertical column 15. In addition, the upper side of the vertical column 15 is provided with a link bar 21 which is provided inside the gear box 19 to be engaged with the gear and rotates. The link bar 21 is installed up and down at a predetermined interval, which is composed of a plurality of so as to transmit a large force. The link bar 21 serves as a robot arm of the robot. The length of the link bar 21 is set in consideration of the height of the patient and the like. That is, when the patient is standing, it is desirable to set the length to maintain the relatively tall patient in a standing state.

On the other hand, the end of the link bar 21 is coupled to the air compressor 23, wherein the end of the link bar 21 and the air compressor 23 is coupled to the hinge axis. A cylinder is provided inside the pneumatic compressor 23, and a cylinder bar 25 connected to the cylinder protrudes outward from the upper side of the pneumatic compressor 23. In this embodiment, three cylinder bars 25 are provided, and the fastening part 27 is coupled to the cylinder bar 25 which protrudes to the outside. The fastening portion 27 is coupled to the upper portion. And the holder 28 is provided in the pneumatic 23 side.

As described above, the upper portion, that is, the weight support bar 29 is coupled to the fastening portion 27. The frame 31 is coupled to the upper portion of the weight support bar 29, the wearing means 33 worn by the patient is suspended on the frame 31. Then, in order to prevent the weight support bar 29 coupled to the frame 31 from being twisted by a load applied according to the front and rear movement of the patient, a horizontal bar 35 connecting the frame 31 is formed. On the other hand, a load cell 37 for detecting the load of the patient is formed between the frame 31 and the weight support bar 29 on which the wearing means 33 hang.

Although not shown in the drawings, in the present invention, a sensor for detecting the movement of the patient is provided to detect the movement of the patient to support the free movement. Control of the mobile motor 3 is made by this sensor.

Here, in the present invention, the panel provided with a key input unit for supporting a user's operation, etc. is installed at an arbitrary position, for example, the cradle 28, but it may be desirable to symmetrically install the left and right sides in consideration of the patient's condition. will be. In addition, to prevent accidents by attaching a number of sensors that identify objects around the robot to prevent collisions with walls and any objects that may occur when the robot moves due to the movement of the body regardless of the patient's will. It may be.

2 is a control circuit block diagram of a pneumatic dispersion control type walking assistance robot according to an embodiment of the present invention. Referring to FIG. 2, the present invention provides a battery 7 for supplying power to the entire system, a key input unit 40 for supporting a user operation, and a left load cell 37 for sensing a load generated by a movement of a patient. ) And the right load cell 37, the ultrasonic sensor 42 and the camera 44 for detecting the direction of movement of the user generates an input signal related to the control. The microprocessor 46 which generates the control signal in response to the input signal is connected to the key input unit 40, the load cell 37, the ultrasonic sensor 42, the camera 44 and the like. The microprocessor 46 operates the pneumatic pump 9 at the same time as the power supply, and performs control in response to the signals of the left load cell 37 and the right load cell 37, respectively, and the ultrasonic sensor 42 or the camera. The left input motor 3 and the right movement motor 3 are respectively controlled by analyzing the signal input from 44. Meanwhile, a vertical motor 17 which is automatically set and controlled by calculating the height of a key in response to a load input from the load cell 37 by data inputted directly by a user or database of correlation between height and weight of a patient. Is connected to the microprocessor 46.

It describes the control process of the pneumatic dispersion control type walking assistance robot of the present invention configured as described above.

The driving of the robot system is made by pressing the power button formed in the key input unit 40, and in this state, the wearing means 33 is worn with the help of a wheelchair or a rehabilitation therapist. Thereafter, as the wheelchair is removed, data regarding the weight of the patient is transmitted from the load cell 37 to the microprocessor 46. This is to determine the angle of lifting the link bar 21, which is the robot arm, by tentatively determining the height related to the weight as described above. Of course, it may be arbitrarily set by an operation of a patient or a rehabilitation therapist. That is, the angle of the link bar 21 may be arbitrarily adjusted by using the key input unit 40 supporting the user operation. In any case, when the link bar 21 is raised in consideration of the height, weight loss of the patient is made. This is illustrated schematically in FIG. 3 before and after the weight deload and the changed situation of the link bar 21.

As the patient or rehabilitation therapist presses the operation button configured in the key input unit 40, the detection of the load cell 37 and the ultrasonic sensor 42 or the camera 44 is performed. The control of the compressor 23 is made, or the drive control of the left moving motor 3 or the right moving motor 3 is made.

First, the process of weight loss of the patient will be described in detail.

As described above, the present invention realizes weight unloading by using the vertical motor 17 and the pneumatic compressor 23, and controls the degree of unloading by measuring the left and right loads respectively. to provide.

To this end, the configuration of the system responsible for the weight deloading function is made by the combination of the vertical motor 17, the pneumatic compressor 23, and the load cell 37 provided for sensing the weight as described above. In addition, by finally transmitting the weight applied by the wearing means 33 to the pneumatic compressor 23 to actively respond to the force transmission from the movement of the patient to buffer the force from the robot received when the user walks the comfort give. This can be modeled as shown in Figure 4 the dynamics of the rehabilitation robot and human.

4 is a diagram illustrating a comparison between a robot and a patient in a dynamic relationship between a vehicle and a wheel. Referring to FIG. 4, assuming that the robot and the person do not fall off the ground, and Zs and Zu are measurable variables, the following equation holds.

here, Is a scalar control input.

If we define states in this equation as

,

,

,

.

The state equation can be expressed as

here,

,

, .

In this way, we derive the state equation and use this equation to design a controller that can minimize vibration without causing pain to the patient. This is illustrated in FIG. 5.

5 is a view schematically showing the configuration and principle of weight loss load. Referring to FIG. 5, in order to simplify the system configuration as described above, the robot arm system has a variable structure, and the robot's rotational axis and the human's rotational axis are in the same line structure. In addition, the load cell 37 and the pneumatic compressor 23 also have a rotational axis of the person, that is, the human, in order to provide the patient's unloading function through the pneumatic compressor 23 by using the data of every moment measured from the load cell 37. Around both shoulders. By placing the weight-bearing device of the robot arm structure configured in this way on both the left and right sides, it is possible to accurately measure and control the load amount. There are many resources needed to construct other systems, but three are particularly important: the load cell 37, the pneumatics 23, and the vertical motor 17, which is the driver of the robot arm.

First, look at the load cell 37, which initially plays a large role in the shape change of the robot, the part that detects the weight of the patient. In addition, in order to cushion the knee impact that may occur when walking in actual rehabilitation training after shape change, the load on the robot at each step must be continuously measured. Therefore, one load cell 37 must be provided on the left and right sides, and the height of the pneumatic compressor is changed according to the change value of the load. By doing so, the impact on the knee of the patient can be greatly reduced, thereby improving the efficiency of rehabilitation training.

The load cell 37 used in the present embodiment uses a load cell 37 capable of measuring up to 100 kg each. This means that if the average person's weight is 70kg, the robot should unload 30% of the weight. In addition, the vertical force generated when walking is much greater, and should be able to measure about 40-50 kg. Since the patient using the robot does not have normal walking ability, it can produce a step that is greatly biased to one side, and when an emergency such as fainting occurs, only one side can take most of the load. In consideration of the mounting load cell 37 corresponding to each 100kg left and right.

Next, referring to the vertical motor 17, the vertical motor 17 used in this embodiment is to be used as a drive for adjusting the height of the key. Since the height-controlled structure is made of the structure of the robot arm consisting of two links, a vertical load of 50 kg is generated on the link of 600 mm, and the vertical motor 17 capable of overcoming this and rotating is It is necessary. Therefore, in the present embodiment, a 130W DC motor is used, and a gear head having a gear ratio of 100: 1 is attached to generate a large torque. It is also mounted on both sides, so it will lift people with 260W of power. In addition, even when a large force is applied to the shaft, a large gear ratio gearhead can be used to prevent the motor from turning in an undesired direction.

Finally, the air compressor 23 is introduced as follows. The pneumatic compressor 23 generally has a built-in pneumatic cylinder, and the patient vibrates up and down about 5 cm when the patient walks, but the elderly or the handicapped tend to have a larger variation. Therefore, in the present embodiment, an air force having a stroke length of 200 mm was used to absorb the force in the vertical direction. In addition, to improve the performance of the system by mounting a pneumatic on the central axis of the person, and received the information of one load cell (37) performed in another task, to control the two pneumatics away from the average value control that had problems in controlling the left and right, One air compressor is mounted on each of the air compressors, and the air compressors can be individually controlled by using the information of the load cells 37 arranged on the left and right sides.

The overall sequence of operations is as follows. When a patient in a wheelchair approaches a robot, the harness is prepared. Adjust the height of the robot according to the height of the person. In this process, the load cell 37 and the DC motor are used. If the weight to be unloaded by the robot is determined in advance, the robot raises the height until the predetermined load is obtained. At this time, the robot changes its shape to the desired height while maintaining the intermediate height of 100 mm, which is a 200 mm stroke used in the robot.

Next, an omnidirectional movement mechanism for following a patient's movement path will be described.

In order to accurately follow the movement path of the patient, the existing two degree of freedom is impossible with the moving part, and in order to follow the path of the patient more practically, the moving part must show mobility having three degree of freedom. The gait of the patient may have a gaze independent of the walking path. That is, the motion is following the walking path and pointing in a different direction. From the point of view of the robot, the position of the two-dimensional plane and the direction at the position are independent of each other, resulting in three degrees of freedom. Since the general walking pattern of the patient is three degrees of freedom, the mobility of the robot that helps the patient to walk should be three degrees of freedom as well. In order for the mobility of the robot to be three degrees of freedom, it must consist of at least two steer-driving wheels 5.

That is, the present invention adopts the structure of the omni-directional wheel capable of three-dimensional motion differently from the existing system that approximately follows the walking pattern of the real user by the motion of the two-dimensional moving part, and moves closest to the actual walking. And mobility. Through this, it is possible to exclude the risk that may occur during the rotation of the robot by the coincidence of the axis of the patient and the drive wheel (5).

6 is a view showing a coordinate system of a two degree of freedom robot on a plane. Referring to FIG. 6, when a rigid robot body is given, the robot coordinate system may be defined as follows. Robot configuration on any plane Is expressed as

First element Is the origin of the robot Position, the second element, the orientation direction Of the robot coordinate system Axis and global coordinate system Shows the difference from the axis. This definition represents the three degree of freedom pose of the robot on the plane. Posture to express robot's motion Becomes a function of time.

Represents the path of the robot or the translational component of the robot, Represents the rotational component of the robot motion. In general, the operation of the robot can be represented by the following three variables. Velocity of Translation Component in Global Coordinate System Direction of translational elements , And the rotational speed of the robot to be.

Thus, the movement of the rigid robot body Is expressed as follows, as shown in FIG. 7 showing the coordinate system of the three degree of freedom robot on the plane.

This equation has three degrees of freedom and is the basis for the robot's motion analysis. Where the robot's posture And direction of movement Are generally independent of each other.

Some typical robots will be described.

The first shows the behavior seen in a normal robot with nonholonomic constraints. This behavior , In other words The attitude of the robot must always match the tangential direction of the path.

The second shows the behavior seen in a synchro-drive robot. The attitude of the robot is fixed, And is called a constant orientation motion. In the synchronous drive robot, all the wheels 5 are rotated at the same speed and steered at the same speed, so that the attitude of the entire robot is fixed to one side and follows the given path.

Third, it shows a combination of the two above. Since each wheel 5 is a steering wheel 5 that can be steered, the change in posture direction can be adjusted irrespective of the path, thereby exhibiting three degrees of freedom.

8 is a diagram illustrating a three degree of freedom movement of the robot with respect to the same trajectory.

Think of a point in the robot's coordinate system, typically the wheel's position.

Robot moves in 3 degrees of freedom This point while doing Let's see how this works. If is called polar coordinate system,

It is expressed as

Suppose the current robot posture and motion are expressed in the global coordinate system as follows.

And, Let 's be some local point of the robot in the robot coordinate system. Then, in the global coordinate system, And Ingredient Wow Is expressed as follows.

In the global coordinate system Speed of operation Is as follows.

Also, in the global coordinate system Direction of movement Is as follows.

And in the robot coordinate system Direction of movement Is as follows.

Since the robot is a rigid body, Rotation speed at Is Same as

9 is a coordinate system showing the movement at any local point of the robot.

Random action Can be thought of as a pure rotational motion without any translational motion for any "center of rotation. If you define

Wow The signs of are the same, Is negative, Is also negative. if, Is 0 Becomes As shown in Figure 9, in the global coordinate system Around Straight line in the direction of Let's define it. And the signed distance value Rotation center of motion with Let's take it. This is If, path To the left of, Back side path Center of rotation on the right side of the Is located. if If, Is located at the infinity of this straight line.

Translation rate elements with the direction of And rotational components The robot's motion represented by a combination of Center of rotation in the robot coordinate system Pure rotational movement around Same as In other words,

if, If, Is Become, Is Converge to the infinity point above. Rotation center in global coordinate system Is,

It is expressed as Any action There is only one center of rotation for. In this relation, the rigid robot's motion is center of rotation. And rotation speed By selecting, 3 degrees of freedom are maintained.

10 is a view showing a concept of implementing a three degree of freedom movement of the robot.

Since the three degree of freedom operation in the control of the moving part can be implemented by at least two or more steerable drive wheels 5, the moving part consists of two steerable drive wheels 5 and a caster. In order to control such a structure, at least a part that recognizes an operation must have three degrees of freedom. That is, three independent values should be sensed. In order to sense the three degrees of freedom of the moving part, first, three moving parts must be sensed: the attitude direction, the moving direction, and the moving speed of the moving part.

The patient is continuously walking while correcting the asymmetrical gait of the rehabilitation patient or the elderly, while simultaneously performing the direction control according to the weight deloading process and the movement path of the patient.

The present invention is not limited to the above-described embodiments, and it will be apparent that many modifications are possible by those skilled in the art within the technical spirit of the present invention.

As described above, the pneumatic dispersion controlled walking aid robot according to the present invention can correct the asymmetrical gait of the patient by training the patient similar to the actual gait so that more effective rehabilitation is possible. In addition, by simplifying the structure by forming the pneumatic and the robot arm integrally, it is possible to remove the element of the pressure to the user. And since it is possible to move, it can be fully utilized as a means of transportation for the elderly, including rehabilitation.

1 is a perspective view of a pneumatic dispersion control type walking assistance robot according to an embodiment of the present invention,

2 is a control circuit block diagram of a pneumatic dispersion control type walking assistance robot according to an embodiment of the present invention;

3 is a view schematically showing the situation before and after weight loss and the changed state of the link bar,

4 is a view explaining the relationship between the robot and the patient in a dynamic relationship between the vehicle and the wheel;

5 is a view schematically showing the configuration and principle of weight loss load,

6 is a view showing a coordinate system of a two degree of freedom robot on a plane;

7 is a view showing a coordinate system of a three degree of freedom robot on a plane;

8 is a view showing the three degrees of freedom of the robot movement on the same trajectory,

9 is a coordinate system showing the movement at any local point of the robot,

10 is a view showing a concept of implementing a three degree of freedom movement of the robot.

Explanation of symbols on the main parts of the drawings

1: housing 3: moving motor

5: wheel 7: battery

9: pneumatic pump 11: board

13: rotary wheel 15: vertical column

17: vertical motor 19: gear box

21: link bar 23: pneumatic

25: cylinder bar 27: fastening portion

29: weight support bar 31: frame

33: wearing means 35: horizontal bar

37: load cell 40: key input unit

42: ultrasonic sensor 44: camera

46: microprocessor

Claims (7)

Weight distribution means for distributing the user's weight bilaterally; A left load sensing means and a right load sensing means for sensing the distributed load degree respectively; Weight deloading means coupled to the weight distributing means to deload the user's weight in response to the degree of load; And Load buffer means coupled to the weight deloading means for performing a buffer in response to the respective signals output from the left load detection means and the right load detection means when the user moves Pneumatic dispersion control walking aid robot, characterized in that made. According to claim 1, Pneumatic dispersion control walking aid robot, characterized in that further formed by the direction detecting means for detecting the user's moving direction to follow the user's movement path. The method of claim 2, wherein the direction detecting means, Ultrasonic sensor or camera for detecting the movement of the user; And Left and right moving motors respectively controlled in response to signal analysis input from the ultrasonic sensor or camera Pneumatic dispersion control walking aid robot, characterized in that made. 4. The method according to claim 2 or 3, wherein the data is measured on the rotational axis of the user in order to continuously perform the unloading function of the user through the load buffering means using the data of every moment measured from the left and right load sensing means. Pneumatic dispersion control type walking assistance robot, characterized in that for forming the left load detection means and the right load detection means. The method of claim 1 or 2, wherein the weight deloading means, A left motor and a right motor which rotate to deload the user's weight and prevent reverse rotation when a load is generated; And To each of the left motor and the right motor, one end is gear-coupled and the other end is hinged to the load buffering means to link up and down the load buffering means. Pneumatic dispersion control walking aid robot, characterized in that made. The pneumatic dispersion control walking aid robot according to claim 1 or 2, wherein the left sensing means and the right sensing means are load cells. 3. The pneumatic dispersion control walking aid robot according to claim 1 or 2, wherein the load buffer means is a pneumatic cylinder.