JP2010213873A - Method for controlling powered artificial limb, and powered artificial limb applied therewith - Google Patents

Abstract

Provided is a power prosthesis control method and a power prosthesis to which the power prosthesis mounted on an affected limb is capable of realizing a sophisticated voluntary movement that has been impossible in the past.
A method for controlling a power prosthesis 1 applied to a human body having a diseased limb A in which a part or all of an upper limb or a lower limb is missing and a joint H that can be arbitrarily moved. Measuring one or more joint displacements of the joint that can be moved as a first joint displacement by the measuring means 3, and a generalized coordinate space of the joint displacement of the power prosthesis 1 from the generalized coordinate space of the first joint displacement A step of calculating an appropriate mapping on the limbs by the calculation means 5 and calculating the second joint displacement as a target value, and using the second joint displacement as a target value, And a step of performing one or a plurality of joint displacement controls, and a power prosthesis to which the power prosthesis control method is applied.
[Selection] Figure 1

Description

  The present invention relates to a method for controlling a power prosthesis and a power prosthesis to which the method is applied.

  First of all, the prosthetic limb application target is a person who loses all or part of the upper limb or lower limb (affected limb) and has a joint that can be moved arbitrarily (hereinafter referred to as a wearer). is there. The power prosthesis targeted in the present invention has a built-in device capable of controlling the angle, angular velocity, torque and the like of each joint in accordance with a command.

  As an example of a prosthetic limb, conventionally, prosthetic hands include i) a decoration that does not move at all, ii) a work-like hook, or iii) a power prosthesis (mainly a myoelectric prosthesis). Issued and provided. You can do most of the work with a hook without power, but you can't hope for a “dexterous hand” function. Also, exercise is necessary to move the myoelectric prosthesis as desired, and even if it becomes possible to move it after practice, it is a rough movement that can select and reproduce one of the few movement patterns prepared in advance. I can only do that.

  There are various variations on the above-mentioned myoelectric prosthesis, but the basic configuration and operation principle is that the myoelectric sensor senses the surface myoelectric potential of the appropriate part of the affected limb, and the output (or the integrated value of the output) is When a certain threshold is exceeded, the switch is turned on and off to operate. At this time, the motor built in the prosthetic hand can perform operations such as grasping and opening the palm, and reproduces the upper limbs and palm that move in a pseudo manner by the wearer.

The operation procedure of myoelectric prosthetic hands so far differs depending on the amputee and the position of the stump or the (congenital or acquired) defect part, but most of them operate the muscle remaining on the stump as a switch. It is.
For example, when the wrist is cut, the surface myoelectric potential generated when the wrist is bent (bending the wrist toward the palm) is “gripped”, and the surface myoelectric potential generated when the back is bent (bending the wrist toward the back) is expressed as “ The operation is performed by providing certain rules for the method of generating the prosthetic hand movement and the surface myoelectric potential, such as “open” (see FIG. 6).
Alternatively, there is a method of driving the power prosthesis by proportional speed control or proportional grip force control according to myoelectric potential instead of on / off (see Patent Document 2).
There is also a method of controlling a power prosthesis by muscle pressure instead of myoelectric potential (see Patent Document 1).

Japanese Patent Laid-Open No. 10-201782 JP 2005-334675 A JP 2008-67852 A

Research on human-support-type robot practical technology development "Development of rehabilitation support robot and practical technology" (Research and development of finger upper limb rehabilitation support system with image training function), 2005-2007 results report, Independent administration New Energy and Industrial Technology Development Organization, March 2008

  However, the surface myoelectric potential used as a switch here is extremely weak, so that it is not easy to detect by the myoelectric sensor, and there is a problem that it takes time until the myoelectric prosthesis is fully used. . In addition, tips were necessary to master it, and it was difficult for everyone to manipulate myoelectric prosthetic hands as expected.

  Furthermore, since the myoelectric prosthetic hand is controlled based on myoelectric information with large measurement noise and low reliability, it is difficult in principle to perform sophisticated control.

In other words, as long as a significant signal can be taken as long as one can be selected and reproduced from a small number of movement patterns prepared in advance, such as simple on / off control such as grasping and opening the palm as described above, control of the prosthetic hand It can be done.
However, for the recent myoelectric prosthetic hand, the types of work and needs that the prosthetic hand bears or wants to make are diversified, and the operation patterns required for the prosthetic hand are diverse.

On the other hand, the more complex the myoelectric prosthesis is to be controlled, the greater the need to detect subtle changes in myoelectricity with higher accuracy. This is accompanied by extremely high technology and leads to cost increase of the prosthetic hand. At the same time, when such a device is actually applied to the affected limb of the wearer, a device that can perform the wearer's intention without any sense of incongruity is completed. In addition, it is necessary to perform adaptation adjustment of the myoelectric sensor and parameter adjustment of the control program, which is very troublesome.
In addition, the prosthetic hand and myoelectric sensor are not always worn, but are repeatedly attached and detached every time when bathing or going to bed. Subtle changes in myoelectricity, as can be seen from the examples where the difference in myoelectric signal can occur due to the quality of the skin, the state of adhesion between the myoelectric sensor and the skin, the presence or absence of sweating, and the movement of the prosthetic hand can be different. In the first place, there is a problem that the information source for high-precision control lacks reliability and is not suitable for sophisticated operations.

As is clear from the examination so far, up to now, myoelectric prostheses continue to be researched from their needs even though they have many problems.
However, the basic structure is merely a reproduction of a finite number of patterns selected based on the myoelectric information. Even if the prosthetic hand selects a pattern based on the wearer's intention, the reliability of the pattern selection algorithm (pattern recognition) is completely as long as the source of information is myoelectricity with large noise and low reliability. Cannot be.

Furthermore, since it is necessary to first acquire myoelectric information of a certain time width for pattern recognition, pattern recognition is performed from the myoelectric information, one of a plurality of patterns is selected, and the myoelectric prosthetic hand is selected. The time lag that occurs before actually moving is inevitable, and its length cannot be ignored. In addition, when such a time delay occurs, the intention of the wearer is not sufficiently reflected and the result is that the prosthetic hand performs an inexplicable motion. As for the form of recognizing a finite number of patterns and reproducing them, improvement by a non-rule-based method such as extracting a reproduction pattern using a neural network has been tried, but there is a time lag corresponding to pattern recognition. There has been no change in what has occurred, and it has not yet solved the essential problem.
When proportional velocity control or proportional grip force control according to myoelectric potential is performed instead of pattern recognition, the intention can be reflected by reducing the time lag depending on whether noise removal of myoelectric information is performed. there is a possibility. However, it is difficult to separate myoelectric information from a plurality of muscles, and it is also difficult for the wearer to generate a plurality of myoelectric potentials independently, and control of 1 to 2 degrees of freedom is the limit. Therefore, even this method has a problem that it is not suitable for a sophisticated operation.
In Patent Document 1, the pressure on the skin surface is measured using a pressure-sensitive element, and the power prosthesis is driven by the information. The pressure-sensitive element has less noise than the myoelectric sensor, and according to the method of Patent Document 1, it is possible to perform control with higher reliability than based on the myoelectric information. However, in this case as well, in order to obtain the pressures of a plurality of muscles separately, it is necessary to provide a large number of pressure-sensitive elements, and it is difficult for the wearer to independently generate a plurality of muscle pressures. It is still not suitable for sophisticated movements.

Incidentally, Patent Literature 3 and Non-Patent Literature 1 disclose the following finger upper limb rehabilitation support system.
FIG. 1 of Non-Patent Document 1 discloses a configuration including a measuring instrument made of a data glove or the like on the healthy side and a rehabilitation assisting device made of a robot hand on the affected side. Further, FIG. 12 of the same document discloses a situation in which the wearer himself / herself supports moving the affected side with the paralysis on the healthy side without the paralysis using the configuration disclosed in FIG. 1. . According to this document, it has been reported that rehabilitation support by the wearer himself / herself may be realized by using such a system.
Further, FIG. 6 of the same document includes a control device having a robot hand and a remote monitor in a remote place where a doctor or therapist is isolated from the patient, and a rehabilitation support hand comprising a robot hand on the patient side. The structure which becomes is disclosed. In FIG. 17 of the same document, using the configuration disclosed in FIG. 6, doctors and therapists check and diagnose remote monitors while rehabilitating fingers of paralyzed patients located in remote locations. The supporting situation is disclosed. According to this document, it has been reported that rehabilitation support from a remote place by a doctor or therapist may be realized by using such a system.
However, in any of these disclosures, it is still the wearer's own palm, fingers, and upper limbs that actually hold or release the object, or touch the third party or the object. The robot arm and robot hand described in this document are only to support the rehabilitation of the wearer's live palm, fingers and upper limbs, and the robot arm and robot hand itself work as the wearer's prosthetic hand. Not what you get.

  As described above, the power prosthesis that is on the extension line of the conventional prosthesis cannot eliminate the essential problems, and even when looking at the related technology, there is not enough in the world. In order to provide a power prosthesis that can meet the demands of users, which are increasing year by year, it is necessary to bring about technological innovation for power prostheses.

  Therefore, the present invention is controlled based on an information source with as little measurement noise as possible, and is capable of realizing a sophisticated voluntary movement that has been impossible in the past in a prosthesis including a power prosthesis worn on the affected limb. It is an object to provide a method for controlling a prosthetic limb and a power prosthesis to which the method is applied.

In order to solve the above-mentioned problems, the present inventor is intended for a person (wearer) who has a joint that can be moved at will while losing a part or all of one upper limb or lower limb (affected limb). In addition, one or a plurality of joint displacements that can be moved arbitrarily is measured as a first joint displacement by the measuring means, and the generalized coordinate space of the joint displacement of the power prosthesis is measured from the generalized coordinate space of the first joint displacement. One or a plurality of joint displacement controls of the power prosthesis applied to the affected limb by the control means with the second joint displacement as a target value by calculating an appropriate mapping to the target by the calculation means As a result, the present invention was completed by finding that it was possible to realize a sophisticated voluntary movement that was impossible in the past in the power prosthesis worn on the affected limb.
In addition to controlling the power prosthesis applied to the affected limb as described above, the present inventor uses the affected limb as a myoelectric prosthesis, and separately acquires myoelectric information such as the affected limb stump using a myoelectric sensor. It has also been found that more various limb control can be achieved.

The power prosthetic limb control method of the present invention that can solve the above-mentioned problems is as follows. (1) Power applied to a human body having a diseased limb lacking part or all of an upper limb or a lower limb, and a joint that can be moved arbitrarily. A method for controlling a prosthesis,
Measuring one or more joint displacements of the optionally movable joint as a first joint displacement by a measuring means;
Calculating a suitable mapping from the generalized coordinate space of the first joint displacement to the generalized coordinate space of the joint displacement of the power prosthesis 1 by a computing means, and calculating as a second joint displacement;
Inputting the second joint displacement into a control means, and controlling the power prosthesis applied to the affected limb;
It is characterized by comprising.

In the power prosthetic limb control method of the present invention, (2) the one or more joint displacements of the power prosthesis can be held by positioning means for controlling to hold one or more joint displacements of the power prosthesis. And
The step of controlling the power prosthesis by the control means and the step of holding one or more joint displacements of the power prosthesis by the positioning means can be arbitrarily switched and executed by the first switching means. It is characterized by that.

In addition, the present invention provides the method for controlling a power prosthesis according to (1) or (2) above, (3) and further comprising a step of acquiring myoelectric information of an appropriate part of the human body using a myoelectric sensor,
Inputting the second joint displacement into the control means and controlling the power prosthesis;
The step of inputting the myoelectric information to the control means and controlling the power prosthesis can be arbitrarily switched by the second switching means.

In addition, the present invention provides the method for controlling a power prosthesis according to (1) to (3) above, (4) and further comprising a step of acquiring myoelectric information of an appropriate part of the human body using a myoelectric sensor,
In addition to the second joint displacement, the myoelectric information is also inputted to the control means so that the control of the power artificial limb can be executed.

Similar to the control method, the power prosthesis of the present invention capable of solving the above-mentioned problems is applied to a human body having (5) an affected limb lacking part or all of an upper limb or a lower limb, and a joint that can be moved arbitrarily. A power prosthesis
Measuring means for measuring one or more joint displacements of the optionally movable joint as a first joint displacement;
Computing means for computing an appropriate mapping from the generalized coordinate space of the first joint displacement to the generalized coordinate space of the joint displacement of the power prosthesis 1 and calculating as a second joint displacement;
Control means for controlling the power prosthesis applied to the affected limb, wherein the second joint displacement is input;
It is characterized by comprising.

In addition, the power prosthesis of the present invention further includes (6) positioning means for performing control for holding one or a plurality of joint displacements of the power prosthesis,
Control of the power prosthesis by the control means;
First switching means capable of arbitrarily switching between control for holding one or more joint displacements of the power prosthesis by the positioning means;
It is characterized by comprising.

Further, the present invention provides the power prosthesis of (5) or (6), wherein (7)
Furthermore, with a myoelectric sensor that can acquire myoelectric information of an appropriate part of the human body,
Control of the power prosthesis performed by inputting the second joint displacement to the control means;
Second switching means capable of arbitrarily switching between control of the power prosthesis performed by inputting the myoelectric information to the control means;
It is characterized by comprising.

In the power prosthesis of (5) to (7), the present invention further includes (8) a myoelectric sensor that can acquire myoelectric information of an appropriate part of the human body,
The said control means is comprised so that control of the said power artificial limb can be performed based on the input of both the said 2nd joint displacement and the said myoelectric information.

  The measuring means is preferably composed of a data glove, a data sock, or a data suit constituted by an encoder method, an optical fiber method, a strain gauge method, a magnetic sensor method, or any combination thereof.

[Terminology]
Here, it is assumed that the power prosthesis referred to in the present specification incorporates means and devices capable of controlling the angles, angular velocities, torques and the like of the respective joints according to commands. For example, as described below, when a power prosthesis is a power prosthesis, generally, a robot arm having a size corresponding to the upper limb corresponds to the upper limb, and a robot hand having a human palm size corresponding to the palm. However, as long as the power prosthesis has a function that complements or substitutes for the function lost by the deficiency, its size, number of degrees of freedom, motor ability, etc. are not necessarily limited to those of human beings. It may be something that expands or adds functions that are not available to humans.

Further, in this specification, “joint” indicates one or a plurality of arbitrary joints among a plurality of joints existing in the wearer's body.
Here, regarding the number of joints of the power prosthesis applied to the wearer, that is, the specific number of joints to be controlled by the present invention, the symptom of the wearer (≈ the position of the stump of the affected limb or the missing part) and the power It also varies depending on the use of the prosthesis.
For example, assuming a power prosthesis, if it is desired to control only the tip of the palm according to the present invention in relation to the position of the stump of the affected limb of the wearer or the missing part, the power prosthesis applied to the wearer The joint generally corresponds to a joint of a robot hand of a human palm size. Of course, the number of joints is also the number of joints of the robot hand.
On the other hand, for a wearer in which a power prosthesis is applied to all upper limbs except the shoulder joint, the number of joints of the power prosthesis is naturally larger than in the above example, and the total number of joints of the power prosthesis is generally (shoulder joint). (Excluding) All joints from the shoulder joint to the tip of the palm finger. All of these correspond to the joints of the robot arm and robot hand.

Further, in this specification, “mirror image” corresponds to an example of “mapping” below, and one n−1-dimensional space (hyperplane S) in n-dimensional (n = 3 in reality) Euclidean space. ) Is defined, for example, an operation of mapping a certain point p1 to a point p2 symmetric with respect to the hyperplane S. Here, the symmetric points refer to two points p1 and p2 that are on the perpendicular to the hyperplane S and have the same distance from the intersection of the perpendicular and the hyperplane S (see FIG. 5).
In addition, the relationship between the two points p1 and p2 that move to each other by this operation, that is, the relationship between the points p1 and p2 that are symmetric with respect to the hyperplane S is also called a mirror image or a mirror.
In this specification, both a mirror image and a mirror refer to the relationship between two points or figures. The operation of moving the original point or figure to the other party in the relationship is called a mirroring operation. In addition, although a mirror image also refers to the figure of the other party in the relationship, in this sense, the term mirror image or mirror image is also used.
Also in this specification, if the mirror surface is completely flat, the mirror image is congruent with the original figure, but it is confirmed that this is not the case in the case of a curved surface such as a concave mirror or a convex mirror.
The “mapping” or “mapping operation” in the present specification corresponds to a superordinate concept of the “mirror image”, and indicates an operation for converting a certain target into a new target. In mapping, when an element x belonging to a certain set X is made to correspond to an element y belonging to a certain set Y, this correspondence is called mapping from the set X to the set Y. A map is sometimes called a function. For example, in the present specification, the set X is a set of one or more joint displacements of a joint that can be moved arbitrarily, and the set Y is a set of joint displacements of a power prosthesis, and sets y corresponding to all sets x. , The mapping from set X to set Y can be defined.
Therefore, as long as an appropriate mapping is defined in the calculation unit (calculation means) of the present invention, for example, a wearer to which a part of one upper limb is missing (affected limb) and a power prosthesis is applied is optional. One or more joint displacement control of the power prosthesis applied to the affected limb using the second joint displacement calculated as a map of one or more joint displacements (first joint displacement) of the lower limb joint that can be moved in an objective manner It is also possible to do this.
Further, in this specification, the “generalized coordinate space” is defined as a set including all of one or a plurality of joint displacement sets in either a joint that can be arbitrarily moved by the wearer or a joint of a power prosthesis. Space. However, the dimension of the joint displacement (unit expressing the joint displacement) is not necessarily a single, and is defined as a generalized coordinate. In other words, linear motion joints and rotary joints may be mixed.
Therefore, the set X and the set Y in the above explanation of the mapping are each a generalized coordinate space, and the element x and the element y, which are specific joint displacement sets, are expressed as points on the generalized coordinate space. At this time, the mapping is a correspondence relationship in which all the points x on the generalized coordinate space X are transferred to the corresponding points y on the generalized coordinate space Y.

  According to the present invention, the affected limb is controlled based on an information source with as little measurement noise as possible. Voluntary movement can be realized.

It is a front view which shows the whole block diagram of one Example of this invention. It is a figure which shows the structure of a computer unit. It is a figure which shows the structure of a main-body part. It is a figure which shows the structure of a data glove. It is a front view explaining the mirror image and mirror operation in this specification. It is a figure shown about the operation point of a myoelectric hand.

Hereinafter, based on an accompanying drawing, an example is given and explained in detail about one embodiment of the present invention.
In the embodiment described below, one or more joints of an upper limb (healthy limb) joint that can be arbitrarily moved with respect to a wearer to which a part of the upper limb of one side is missing (affected limb) and a power artificial hand is applied A power prosthesis constructed for the purpose of controlling one or more joint displacements of the power prosthesis applied to the affected limb using the second joint displacement calculated based on the displacement (first joint displacement) as a target value ( System) 1.
It should be noted that “a suitable mapping from the generalized coordinate space of the first joint displacement to the generalized coordinate space of the joint displacement of the power prosthesis is calculated by the calculation means and is defined in a generalized form in the present invention. In the present embodiment, the process of “calculating as two joint displacements” corresponds to obtaining a mirror image corresponding to a subordinate concept of the mapping. For example, “each of the mirror images related to each joint whose first joint angle is measured” The joint angle is calculated by the calculation means and calculated as the second joint angle ”. Details regarding the mirror image (or mirror operation) will be described in detail later. That is, the description of the mirroring control of the power prosthetic hand performed from this point is understood as one example of the control based on the mapping operation defined in a generalized form in the present invention.
The power prosthesis 1 according to the present embodiment controls the data glove 3 that can be worn on the healthy limb H, the main body 2 of the power prosthesis 1 applied to the affected limb A, and both, as shown in FIG. The computer unit 4 is basically configured.

[Basic configuration]
As shown in FIG. 3, in the present embodiment, the main body 2 of the power prosthesis 1 is composed of a robot arm 10 having a size corresponding to the upper limb and a robot hand 20 having a human palm size. Here, the main body 2 is made-to-order, so to speak, the outer shape and the total number of joints included differ depending on the stump position of the affected limb A of the wearer. It is not limited to the shape of FIG. 1 or FIG. The wearer described in FIG. 1 and FIG. 3 has a stump (which may be a terminal end of a defect portion, but hereinafter referred to as a stump) E between the shoulder joint 11a and the elbow joint 12a. At this time, the main body 2 is configured to cause the robot arm unit 10 and the robot hand unit 20 built in itself to take charge of the functions of all joints other than the shoulder joint 11a (all joints of the palm fingers from the elbow joint 12a). It has become.

  As shown in FIG. 3, both the robot arm unit 10 and the robot hand unit 20 are means and devices capable of controlling the angles and the like of each joint that each has in response to a command from the computer unit 4. . Servo motors are built in the joints 12a and 13a of the robot arm. Also, each joint 21-1a, 21-2a (thumb), 22-1a, 22-2a, 22-3a (index finger), 23-1a, 23-2a, 23-3a (middle finger), 24- 1a, 24-2a, 24-3a (ring finger), and 25-1a, 25-2a, 25-3a (little finger) are linked mechanisms respectively linked to respective servo motors built in the base side of each finger. Driven by. In addition, the control method itself of the power prosthesis 1 by mirroring according to the present invention in which the main body 2 of the power prosthesis 1 applied to the affected limb A is mirrored in accordance with the movement of the healthy limb H will be separately described later. .

  The robot arm unit 10 and the robot hand unit 20 are both built in the outer layer 31 of the main body unit 2. The outer layer 31 of the main body 2 is manufactured at a high level that is as close to human as possible, such as color, texture, and touch. The aspect may be considered the same as the conventional myoelectric prosthesis.

  As shown in FIG. 2, the computer unit 4 includes a basic configuration of an input unit 41, a calculation unit 5, and an output unit 42. As will be described later, the computer unit shown in FIG. 2 also includes a correction unit 6 and a positioning unit 7. Both operations and functions will be described separately later. The connection relationship of each block is as shown in FIG.

  As shown in FIG. 2, the computer unit 4 is built in the outer layer 31 of the main body 2, similar to the robot arm 10 and the robot hand 20. The computer unit 4 is connected to the robot arm unit 10 and the robot hand unit 20 by wire and has a structure capable of signal communication. More specifically, the computer unit 4 includes the servo motors built in the joints 12a and 13a of the robot arm unit 10 and the joints built in the base side of each finger of the robot hand unit 20, respectively. 21-1a, 21-2a (thumb), 22-1a, 22-2a, 22-3a (index finger), 23-1a, 23-2a, 23-3a (middle finger), 24-1a, 24-2a, 24 -3a (ring finger) and 25-1a, 25-2a, 25-3a (little finger) drive servomotors.

On the other hand, the computer unit 4 can wirelessly communicate with the data globe 3. Therefore, in the present embodiment, the first joint angle is input from the data glove 3 to the computer unit 4 by wireless communication.
The computer unit 4 calculates each joint angle of the mirror image related to each joint for which the first joint angle is measured, and calculates it as the second joint angle. In the present invention, the calculation process is as follows: “A suitable mapping from the generalized coordinate space of the first joint displacement to the generalized coordinate space of the joint displacement of the power prosthesis is calculated by the calculation means, and the second joint displacement is obtained. It can be specified in a generalized form as a “calculating” process.
The computer unit sends a drive signal to the servo motors of the corresponding joints using the second joint angle as a target value.

  As shown in FIG. 4, the data glove 3 has a structure that can be worn on the healthy limb H, and measures one or a plurality of joint angles of the healthy limb H and outputs it as a first joint angle to the outside. It has a structure that can be. The number of joint angles measured and output as the first joint angle corresponds to the number of joints of the power prosthesis 1 applied to the affected limb A.

In the data glove 3 according to the present embodiment, when worn, each joint 21-1h, 21-2h (thumb), 22-1h, 22-2h, 22-3h (index finger), 23-1h, 23-2h, 23-3h (middle finger), 24-1h, 24-2h, 24-3h (ring finger) and 25-1h, 25-2h, 25-3h (small finger), and a plurality of ( For example, around 20 angle sensors are provided. In this embodiment, the angle sensor is a rotary encoder. As a result, it is possible to output fine movement linearly and accurately.
Furthermore, in the present embodiment, the angle of the wrist, elbow, and shoulder joints 13h, 12h, and 11h of the healthy limb H can be detected by appropriately increasing or decreasing the number of angle sensors.

In addition to the above, various proposals have been made for the basic measurement procedure of the degree of finger bending applied to the data glove 3, and among them, typical optical fiber method, strain gauge method, magnetic sensor method or These combinations can be applied.
In the optical fiber system, an optical fiber made of resin is put on the outer surface of the glove, and the light receiving part at the other end where the light from the light emitting part at hand is reduced by the bending of the finger and returned by the fingertip. The basic principle is to obtain information on the degree of flexion of the finger. Preferably, the bending portion to be measured is made to have a particularly large reduction in bending. Here, when two reciprocating fibers corresponding to the first finger and the second finger of each finger are incorporated in the glove, the bending degree of the first joint and the second joint of the finger can be individually measured.
The strain gauge method uses a plurality of (for example, around 20) thin, flexible, strain gauges embedded in the glove, corresponding to resistance elements. This method linearly measures the degree of opening, bending of the palm, and movement of the wrist.
In the magnetic sensor system, the position and orientation information in a three-dimensional space is obtained by embedding a magnetic sensor on the back side of the wrist of the glove and capturing a magnetic field from an external transmission coil.

[Mirror image and mirror operation]
Here, the mirror image and the mirroring operation, which are the basic operation principle of the mirroring control of the present invention, will be described. FIG. 5 is a diagram for explaining a mirror image and a mirroring operation in this specification.

As shown in FIG. 5, in this embodiment, “mirror image” means one two-dimensional space (superplane S in the three-dimensional Euclidean space. In this embodiment, the hyperplane S penetrates the body axis, and this is the boundary. When the left and right upper limbs of the wearer are determined to indicate a plane that divides the upper limb into the healthy limb H side and the affected limb A side, for example, a certain point p1 is mapped to a point p2 that is symmetric with respect to the hyperplane S It is an operation to do. Here, the symmetric points are two points p1 and p2 that are on the perpendicular to the hyperplane P and have the same distance from the intersection of the perpendicular and the hyperplane P.
On the premise of the basic principle of the mirror image described above and the setting state of the hyperplane S in the present embodiment, the main body portion 2 of the power prosthesis 1 applied to the affected limb A is mirrored in accordance with the movement of the healthy limb H. The

  In this embodiment, the hyperplane S that is assumed to be a “mirror surface” is assumed to be completely flat. As a result, the resulting mirror image (or mirror image) is congruent with the original figure.

Hereinafter, generation of a control signal related to mirroring control and a process flow in which the main body 2 of the power prosthesis 1 is controlled will be described.
First, for the first joint angle input to the computer unit 4, each joint angle of a mirror image related to each joint obtained by measuring the first joint angle is calculated in the computer unit. The calculation result is calculated as the second joint angle. The mirror image here is as described above.

Next, from the computer unit 4, the calculated second joint angle is set as a target value to each joint of the power prosthesis 1 (corresponding to each joint on the healthy limb H side where the first joint angle is measured). A command is issued to drive the servo motor.
Each joint of the power artificial limb corresponding to each joint on the healthy limb side where the first joint angle is measured is driven using the second joint angle as a target value based on a command from the computer unit.

  The signal related to the first joint angle input to the computer unit 4 corresponds to an output value from the data glove 3. In general, a data glove may be considered to have little measurement noise and to output highly accurate measurement data.

  Here, with respect to the above-described series of controls, the servomotors built in each joint of the power prosthesis 1 are driven by feedback control such as PD control and PID control, that is, based on a command from the computer unit 4, A configuration may be adopted in which servomotors built in each joint of 1 are sequentially feedback-controlled toward the second joint angle that is the target value.

  As described above, one or both of the robot arm 10 and the robot hand 20 related to the power prosthesis 1 of this embodiment are driven with the second joint angle as a target value. According to the present embodiment, the power prosthesis 1 applied to the affected limb A is mirrored in accordance with the movement of the healthy limb H, and the power prosthesis 1 moves in a mirror image of the healthy limb H.

[Other functions]
The power prosthesis 1 of the present embodiment having the above-described configuration and basic operation principle further has the following functions.

  As shown in FIG. 2, the computer unit 4 of the present embodiment also includes a correction unit 6 and a positioning unit 7. The built-in memory 6a of the correction unit stores and stores in advance each joint movable range of the power prosthesis.

The correction unit 6 applies the second joint angle calculated by the calculation unit 5 to each joint movable range of the healthy limb H and the affected limb A side from each joint angle of the mirror image of the first joint angle. Correction is made to an angle range in which each joint movable range of the robot arm 10 or the robot hand 20 according to the unit 2 coincides. Each servo motor built in the robot arm 10 or the robot hand is driven using the corrected second joint angle as a target value.
Such a configuration for performing angle control of one or a plurality of joints of the power prosthesis 1 applied to the affected limb A using the corrected second joint angle as a target value is that of the healthy limb H and the power prosthesis 1. This is particularly useful when the movable range is significantly different.

  By the function of the correction unit 6, mirroring control is performed in accordance with the movement of the healthy limb H, and the destruction of the power prosthetic hand 1 (which is the object to be controlled) that has stopped to perform the mirror image movement of the healthy limb H is prevented. Life can be extended.

The positioning unit 7 performs control to maintain the angles of one or more joints of the power prosthesis 1. In the present embodiment, the first switching means 8 connected to the input unit 41 controls the positioning unit 7 to maintain the angle of one or more joints of the power prosthesis 1 or obtains it from the data glove 3. Further, it is configured to switch whether each joint angle of the main body 2 is mirrored based on the first joint angle.
Here, when the switching signal from the first switching means 8 is input to the input unit 41, as an example of the first switching means 8, voice, vibration using the lower limbs, and each provided for the lower limbs are provided. Means such as a dedicated switch (push button, slide switch, toggle switch, etc.) can be used. The same applies to the second switching means 9 described later.

Mirroring control is performed by the positioning unit 7 in accordance with the movement of the healthy limb H, and the movements of the power prosthetic hand 1 applied to the affected limb A and the movement of the healthy limb A, which are stopped when performing the mirror image movement of the healthy limb H, respectively. Can be separated.
That is, by causing the positioning unit 7 to function, the left and right upper limbs can be in different postures as necessary.
By making the positioning unit 7 function, for example, i) lift the dish on which the coffee cup is placed with both the power prosthetic hand 1 and the healthy limb H, ii) hold the dish with the power prosthetic hand 1, and iii) spoon with the healthy limb H It is also possible to move the spoon inside the coffee cup. At this time, in i), mirroring control is performed in accordance with the movement of the healthy limb H. In ii) and iii), the limb A side is controlled to maintain the angle of one or more joints of the power prosthesis 1 by the positioning means 7. At this time, the healthy limb H side is free. Whether the mirroring control is performed or the holding control for maintaining the angle of each joint by the positioning means 7 is performed by the first switching means 8 before being switched to ii) and iii).

  Further, the power prosthesis 1 of this embodiment includes a myoelectric sensor 30 that acquires myoelectric information of the stump E of the affected limb A at a joint end portion of the main body 2 with the stump E of the affected limb A. Yes. Therefore, the power prosthetic hand 1 of the present embodiment is also a so-called myoelectric prosthetic hand that can perform force control such as gripping force based on the acquired myoelectric information.

As shown in FIG. 2, the myoelectric information from the myoelectric sensor 30 is input to the input unit 41 of the computer unit 4.
Here, the input unit 41 is also connected to the second switching means 9. A switching signal from the second switching unit 9 is input to the input unit 41. In the present embodiment, the second switching means 9 controls the gripping force based on the myoelectric information from the myoelectric sensor 30 or the main unit 2 based on the first joint angle obtained from the data glove 3. It is configured to be able to switch between mirroring control of each joint angle.
When grip force control is performed, for example, in the case of the coffee cup described above, ii) when holding the plate with the power prosthesis 1, it is not a simple positioning holding control. Appropriate grip force control is required so that the plate does not break due to being gripped too much. Therefore, first, in i), the power prosthesis 1 is mirrored and controlled to a shape that allows the dish to be properly gripped, and before entering ii), the second switching means 9 is used to switch to grip force control based on myoelectric information in advance. . In the grip force control based on the myoelectric information, the output unit 42 outputs the myoelectric information input to the calculation unit 5 as a torque command for the servo motor based on a force control law stored in advance in the memory 5a connected to the calculation unit 5. Is sent to the robot hand unit 20. The robot hand 20 receives the torque command and controls the grip force. As for the second switching means 9, as described above, an appropriate one may be selected according to the circumstances.
The myoelectric prosthetic hand that has been known so far has a weak myoelectric signal from the electromyographic sensor and a lot of noise, and it is extremely difficult to recognize the pattern. Due to this imbalance, there was a problem in its practicality.
According to the present embodiment, the element controlled by the myoelectric signal can be significantly reduced to one degree of freedom information such as grip strength, for example. The reliability of myoelectric sensors if limited to analog information (not discrete on-off information) indicating how much force is applied, acquired by myoelectric sensors provided at appropriate sites such as stumps of affected limbs Therefore, the control based on myoelectric analog information is sufficiently possible.
Therefore, even if the control based on the analog information by the myoelectric signal (analog myoelectric control) and the mirroring control can be switched and executed by the second switching means, it is sufficiently practical when viewed as the entire device. The power prosthesis to which the present embodiment is applied can be used in a state in which
Here, one point of the present embodiment is that the myoelectric information is not used as discrete information such as pattern recognition but is used as a continuous analog value. This is also alive because of switching to mirroring. Conventionally, there has been an attempt to use myoelectricity as analog information, but since it can be separated into only one or two pieces of analog information, it has not been possible to perform sophisticated control. However, if switched, even one or two pieces of analog information can be sufficiently useful if used well, for example, as a grip force control command.

In place of the configuration using the switching signal from the second switching means 9 described above, depending on the wearer's own will, a) the main body 2 based on the first joint angle obtained from the data glove 3 It is also possible to adopt a configuration in which the feedback gain of feedback control performed on the power prosthesis is changed based on the myoelectric information from the myoelectric sensor 30 at the same time that the joint angles are mirrored. That is, in this example, in the control method of the power prosthesis 1, the myoelectric sensor 30 acquires the myoelectric information of an appropriate part such as the stump E of the affected limb A and the power prosthesis 1 One or a plurality of joint controls can be performed based on both a) the target joint angle of the mirror image of the healthy limb H calculated by the above calculation, and b) the acquired information from the myoelectric sensor 30. It is.
By applying this embodiment, the feedback gain of the power prosthesis 1 (for example, the impedance corresponding to the spring damper coefficient in the PD control) can be adjusted according to the wearer's will, if necessary. The force applied in the mirroring operation of the affected limb A can be made different. Further, by applying the present embodiment, for example, with respect to the affected limb, i) it is possible to control the gripping force separately by myoelectricity while maintaining a posture in which something is once gripped.
Thus, instead of the configuration using the switching signal from the second switching means 9, each joint angle of the main body 2 is controlled by mirroring based on the first joint angle obtained from the data glove 3, Based on the myoelectric information from the sensor 30, it is possible to change the feedback gain of the feedback control performed by the power prosthesis. For example, it is useful when the object is gripped by mirroring control without using the switching means. It becomes.
In general, even if an object of the same shape (that is, the posture to be taken by the power prosthesis 1 is the same), if it is heavy and difficult to break, it is necessary to lift the joint control of the power prosthesis 1 firmly, but it is light and fragile. In the case, it is necessary to soften the joint control of the power prosthesis 1 and lift it. In such a case, if the configuration is such that the feedback gain can be changed by the myoelectric information, if it is desired to make the joint control hard, the muscles of the stump E of the affected limb A are arbitrarily pressed, and the myoelectric information For example, the PD feedback gain of mirroring control is increased proportionally. Then, the mirroring control behaves as if it is coupled to the second joint angle that is the target value with a hard spring damper, the joint control becomes hard, and it becomes easy to lift a heavy object. Conversely, if the muscle force of the stump E is removed and the PD feedback gain of the mirroring control is lowered, the mirroring control behaves as if it is connected to the second joint angle with a soft spring damper and lifts a fragile one. Becomes easy.
Since the above configuration is a method of adjusting the control gain of mirroring control based on myoelectric information, it is used together with the configuration using the holding control and the switching signal from the second switching means 9 as well as the mirroring control. Is possible.

[Usefulness of this example]
According to the present embodiment, since it is possible to perform sophisticated control of the power prosthesis, it is possible to pioneer new needs for the power prosthesis. In addition, according to the present embodiment, both hands basically perform the same (symmetric) movement as a mirror image, but even if both hands perform the same movement, most of what could not be done with one hand can be performed. Become. This is also clear from the fact that almost all work can be performed with, for example, a work hook prosthesis widely used at present.
In addition, according to the present embodiment, for example, a robot hand of an affected limb corresponding to a human palm is manufactured at a high level that is as close as possible to a human, such as color, texture, and touch, so that not only the operation but also the appearance problem Can be solved simultaneously.

  Furthermore, by using this embodiment together with conventional myoelectric control, a slight difference in motion is set (between a healthy limb and an affected limb) while being based on a symmetric motion that is a mirror image motion. It is possible. As a result, work with wider variations becomes possible.

  With various prosthetic hands that have been provided in the past, it has been difficult to simultaneously satisfy the two types of needs of decoration and work at a high level. In addition, the conventional myoelectric prosthetic hand can be one of the solutions, but the operation is too rough, and it is not suitable for the elaborate work that human hands do, and the work is difficult. It was a thing.

  However, according to the present embodiment, it is possible to control a power prosthesis with high speed and high accuracy although it is basically a mirror image operation. This would provide the best solution possible with current technology, which is very useful for amputees who are inconvenient to current prosthetic hands. No more functions can be realized unless the so-called brain machine interface (technology that directly connects the human brain and nervous system to the machine) reaches a practical level.

[Modification]
Although the present invention has been described in detail with reference to one embodiment, the present invention is not limited to the configuration of the above embodiment and can be modified in various ways.

For example, in this embodiment, the measuring means is composed of the known data glove 3, but the measuring means is not limited to this, and the first joint angle information of each joint of the healthy limb H in the space is stored in the computer. Anything that can be input to the unit 4 may be used. A method in which an encoder, an optical fiber, and the like are provided in each joint may be used.
In addition to measuring each joint angle by the data glove 3, in addition to measuring each joint of each finger, outputting a bending amount of n fingers as n numerical values, distance between fingers or opening It is possible to apply various measures other than those described in this embodiment, such as those for measuring the angle, measuring the degree of bending of the palm, and measuring the bending of the wrist.
In addition to the information on the first joint angle of each joint of the healthy limb H in space, if the spatial position information can be input to the computer unit 4, the accuracy of the mapping operation is further improved. For example, the absolute position and posture data of the hand can be measured by separately providing a motion tracker device such as a magnetic sensor or an inertial sensor. As a result, angle information such as hand roll, pitch, and yaw and coordinate information in the X, Y, and Z axis directions can also be measured.

  In this embodiment, the computer unit 4 is built in the main body 2. However, the present invention is not limited to this, and a structure in which both are separated may be used.

  In the present embodiment, wireless communication is performed between the data globe 3 and the computer unit 4, and wired communication is performed between the computer unit 4 and the main body 2. However, the present invention is not limited to this, and the data is well transmitted. The method is not particularly limited as long as it can be communicated.

  Further, in this embodiment, as an example of the first switching means 8 or the second switching means 9, voice, vibration using the lower limbs, dedicated switches provided on the lower limbs (push buttons, slide switches, toggle switches, etc.) The first switching means 8 or the second switching means 9 is not limited to these examples, and is not particularly limited as long as each function can be satisfied.

  In the present embodiment, the correction unit 6 is provided, but the configuration of the present embodiment is not limited to this. That is, if the range of motion of each joint of the power prosthesis 1 is designed to be sufficiently wide enough to be comparable to that of the healthy limb H, even if the correction means 6 is omitted, there is a particularly big problem in practice. It cannot happen.

  In the present embodiment, the myoelectric sensor 30 is provided at the joint end portion of the main body 2 with the stump E of the affected limb A, and the myoelectric information of the stump E of the affected limb A is acquired by the myoelectric sensor. However, the configuration of the present invention is not limited to this. That is, if a so-called myoelectric prosthesis can be configured based on the myoelectric information acquired from the affected limb A, for example, a force control such as a grip force, the myoelectric sensor can be provided in the power prosthesis 1 (of the present invention). The position where it is provided is not particularly limited.

Furthermore, in the above embodiment, a power prosthesis has been described as an example of a power prosthesis to which the present invention is applied. However, the application target of the present invention may be not only a prosthetic hand but also a prosthetic leg.
Here, in the case where the application target of the present invention is a power prosthesis, the measuring means that is made of a known data glove in this embodiment may be made of a data sock or a data suit.
The first joint displacement measuring means may include an appropriate noise filter. For example, it is preferable to output a first joint displacement after applying a low-pass filter to the measured data and removing noise. In addition to noise removal, even when an involuntary tremor, such as due to Parkinson's disease, is observed in the motion of a healthy limb, when this is measured by the first joint displacement measuring means, the tremor By removing this with an appropriate filter and using it as the first joint displacement, it is possible to map to the second joint displacement based on an optional motion without being affected by tremor.
Further, in this embodiment, various descriptions have been given using mirror images as an example of mapping from the general coordinate space of the first joint displacement to the generalized coordinate space of the second joint displacement. It is not limited to a mirror image. For example, the first joint displacement from the data glove is mapped to the second joint displacement of the power prosthesis, the first joint displacement from the data socks is mapped to the second joint displacement of the power prosthesis, or human Mapping to expand the range of motion to the joint displacement of the prosthetic hand, which has a wider range of movement than the joints of the joint, or conversely to map to reduce the range of motion to the joint displacement of the prosthetic hand capable of precise operation It is possible to perform non-linear mapping so that the reduction is properly used depending on the joint position, or any other mapping can be configured. Further, the proper use of these mapping relationships is not necessarily fixed, and may be appropriately used. For example, the enlargement / reduction ratio is appropriately adjusted with a knob provided on the hand.
In the present embodiment, various descriptions have been given on the assumption that the affected limb is partially cut, but the wearer to which the present invention is applied is not limited to the amputee. For example, the present invention can be applied to malformations caused by drug damage such as thalidomide or genetic factors. In that case, for example, if the affected limb that has become abnormally small due to malformation is capable of voluntary movement, wear a data glove, data socks or data suit on the affected limb, and wear a power prosthesis to cover the affected limb. It is possible to control the power prosthesis by appropriate mapping.

In addition, in the above embodiment, as an example of a power prosthesis to which the present invention is applied, a power prosthesis having a shape and performance similar to that of a human hand has been described in various ways, but in the present invention, the structure of the prosthesis is as follows: There are no restrictions on the shape and performance similar to those of human limbs.
For example, if the data suit measures all joint displacements that can be voluntarily moved throughout the body other than the missing part, a vast generalized coordinate space of several tens of degrees of freedom can be constructed. According to the mapping, the prosthesis to be attached to the defect portion can be controlled with several tens of degrees of freedom.
Therefore, in this case, a prosthetic limb such as a huge robot arm having several tens of degrees of freedom may be used. Cases that can be envisaged include i) who usually wear humanoid prosthetic hands, but ii) when working, switch to a large robot arm and do hard work. In addition, the modification demonstrated here is a premise that it is a prosthesis applied to a wearer's defect | deletion part to the last.

  The power prosthesis control method according to the present invention described above and the power prosthesis to which the method is applied can be implemented by various implementations such as the manufacturer of the power prosthesis or the manufacturer seeking the application destination of the robot. It is a new and useful invention.

A Affected limb H Healthy limb 1 Power prosthesis 2 Main body part 3 Data glove 4 Computer unit 5 Calculation part 6 Correction part 7 Positioning part 8 First switching means 9 Second switching means 10 Robot arm part 11a, 12a, 13a Robot arm Each joint 11h, 12h, 13h Each joint of the healthy limb 20 Robot hand part 21-1a, 21-2a Each joint (thumb) of the robot hand part
21-1h, 21-2h Each joint (thumb) of a healthy limb
22-1a, 22-2a, 22-3a Each joint (index finger) of the robot hand unit
22-1h, 22-2h, 22-3h Each joint of the healthy limb (index finger)
23-1a, 23-2a, 23-3a Each joint (middle finger) of the robot hand
23-1h, 23-2h, 23-3h Each joint (middle finger) of healthy limbs
24-1a, 24-2a, 24-3a Each joint (ring finger) of the robot hand unit
24-1h, 24-2h, 24-3h Each joint (ring finger) of a healthy limb
25-1a, 25-2a, 25-3a Each joint (little finger) of the robot hand
25-1h, 25-2h, 25-3h Each joint (little finger) of a healthy limb
30 Myoelectric Sensor 31 Outer Layer 41 Input Unit 42 Output Unit

Claims (9)

A method for controlling a power prosthesis applied to a human body having a diseased limb lacking a part or all of an upper limb or a lower limb, and a joint that can be moved arbitrarily,
Measuring one or more joint displacements of the optionally movable joint as a first joint displacement by a measuring means;
Calculating a suitable mapping from the generalized coordinate space of the first joint displacement to the generalized coordinate space of the joint displacement of the power prosthesis 1 by a computing means, and calculating as a second joint displacement;
Inputting the second joint displacement into a control means, and controlling the power prosthesis applied to the affected limb;
A power prosthesis control method comprising: Furthermore, one or more joint displacements of the power prosthesis can be held by positioning means that performs control to hold one or more joint displacements of the power prosthesis,
Controlling the power prosthesis by the control means;
Holding one or more joint displacements of the power prosthesis by the positioning means;
The method for controlling a power prosthesis according to claim 1, characterized in that it can be executed by being arbitrarily switched by the first switching means. Furthermore, the method includes a step of acquiring myoelectric information of an appropriate part of the human body by an electromyographic sensor,
Inputting the second joint displacement into the control means and controlling the power prosthesis;
Inputting the myoelectric information to the control means and controlling the power prosthesis,
The method for controlling a power prosthesis according to claim 1 or 2, characterized in that it can be arbitrarily switched by the second switching means. Furthermore, the method includes a step of acquiring myoelectric information of an appropriate part of the human body by an electromyographic sensor,
4. The apparatus according to claim 1, wherein in addition to the second joint displacement, the myoelectric information is also input to the control means so that the control of the power artificial limb can be executed. 5. The power prosthesis control method described. A power prosthesis applied to a human body having a diseased limb that lacks a part or all of an upper limb or a lower limb, and a joint that can be moved arbitrarily,
Measuring means for measuring one or more joint displacements of the optionally movable joint as a first joint displacement;
Computing means for computing an appropriate mapping from the generalized coordinate space of the first joint displacement to the generalized coordinate space of the joint displacement of the power prosthesis 1 and calculating as a second joint displacement;
Control means for controlling the power prosthesis applied to the affected limb, wherein the second joint displacement is input;
A power prosthesis characterized by comprising: Furthermore, it has positioning means for controlling to hold one or more joint displacements of the power prosthesis,
Control of the power prosthesis by the control means;
Holding one or more joint displacements of the power prosthesis by the positioning means;
The power artificial limb according to claim 5, further comprising first switching means that can be arbitrarily switched. Furthermore, with a myoelectric sensor that can acquire myoelectric information of an appropriate part of the human body,
Control of the power prosthesis performed by inputting the second joint displacement to the control means;
Control of the power prosthesis performed by inputting the myoelectric information to the control means,
A power prosthesis according to claim 5 or 6, further comprising second switching means that can be arbitrarily switched. Furthermore, with a myoelectric sensor that can acquire myoelectric information of an appropriate part of the human body,
The said control means is comprised so that control of the said power artificial limb can be performed based on the input of both the said 2nd joint displacement and the said myoelectric information. The power prosthesis according to claim 1.   6. The measuring means comprises a data glove, a data sock, or a data suit composed of an encoder method, an optical fiber method, a strain gauge method, a magnetic sensor method, or any combination thereof. The power artificial limb according to any one of 8.

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