JP5147595B2 - Control device and control method for walking assist device - Google Patents

Description

  The present invention relates to a control device and a control method for a walking assist device, and more particularly, to a control device and a control method for a walking assist device that individually apply a force generated by a power generation device to left and right legs as an assist force.

  Various walking assistance devices that individually apply the force generated by the power generation device to the left and right legs as assist forces have been proposed (for example, Patent Documents 1 and 2).

As a control device for the walking assist device, the target value for the left leg according to the ratio of the pedal force of the device user's left leg and the right leg as the target value of the upward lifting force that acts on the device user by the walking assist device There is one that performs walking assist control in which the share of the burden and the target share of the right leg are distributed and the assist force corresponding to the target share is applied to the left and right legs (for example, Patent Documents 3 and 4).
Japanese Patent Laid-Open No. 7-112035 JP 2004-344305 A JP 2007-54616 A JP 2007-330299 A

  In conventional walking assist control, if the device user's center of gravity is biased back and forth and left and right due to walking posture, working posture, heavy material transportation, etc., and the load balance between the left and right legs is lost, Compensation control for returning the position of the center of gravity to an appropriate position is not directly performed. For this reason, in the conventional walking assist control, it is not possible to expect an operation for quickly recovering that the load balance between the left and right legs is lost.

  The problem to be solved by the present invention is to promptly confirm that the load balance between the left and right legs is lost when the center of gravity of the device user is biased back and forth and left and right due to walking posture, working posture, heavy material transportation, etc. To recover.

  The control device for the walking assist device according to the present invention is a control device for the walking assist device that individually applies the force generated by the power generation device as the assist force to the left and right legs, and acts on the left and right feet of the user of the device. The floor reaction force measuring means for measuring the floor reaction force on the left and right separately, and the assist force for compensating the balance of the load burden on the left and right legs of the device user using the floor reaction force measured by the floor reaction force measurement means. Assist force calculating means for calculating, and control command calculating means for calculating left and right individual control command values to be output to the power generation device in accordance with the assist force calculated by the assist force calculating means.

  According to the control device of the walking assist device according to the present invention, the assist force for compensating the balance is calculated using the measured value of the floor reaction force acting on the left and right feet of the device user, and the power is generated according to the assist force. Since the control command value to be output to the device is calculated, when the center of gravity of the device user is biased back and forth and left and right due to walking posture, work posture, heavy material transportation, etc., the left and right legs of the device user Control to restore the load balance is performed directly, and it is possible to quickly recover that the load balance of the left and right legs is lost.

  The control device for the walking assist device according to the present invention preferably calculates the positional relationship between the estimated position of the left and right feet of the device user and the position of the center of gravity using the floor reaction force measured by the floor reaction force measuring means. Balance compensation that calculates an assist force that compensates the load balance of the left and right legs of the device user based on the foot position estimation / gravity position calculation unit and the barycentric position calculated by the foot position estimation / gravity position calculation unit An assist force calculation unit.

  According to the control device of the walking assist device according to the present invention, the positional relationship between the estimated position of the left and right feet of the device user and the position of the center of gravity is obtained using the measured value of the floor reaction force acting on the left and right feet of the device user. Since the calculation is performed and the assist force that compensates the balance of the load burden on the left and right legs of the device user is calculated based on the position of the center of gravity with respect to the estimated position of the foot, the walking posture, work posture, heavy object transportation, etc. Thus, when the position of the center of gravity of the user of the apparatus is deviated from front to back and from side to side, it is possible to quickly recover from the fact that the load balance between the left and right legs is lost.

  The control device for the walking assist device according to the present invention is preferably configured such that the assist force calculating means performs balance compensation when a change per unit time in the floor reaction force measured by the floor reaction force measuring means is a predetermined value or more. The assist command is calculated, and the control command calculation means outputs a control command based on the assist force to the power generation device.

  According to the control device of the walking assist device according to the present invention, the balance compensation control is performed when the change in the floor reaction force per unit time is not less than a predetermined value, that is, when the position of the center of gravity of the device user changes abruptly. Thus, the balance compensation control is not performed.

  The control device of the walking assist device according to the present invention preferably further includes a biological measurement unit that measures a biological state value of the device user, and the assist force calculation unit is measured by the floor reaction force measurement unit. When the change per unit time of the floor reaction force is greater than or equal to a predetermined value and the biological state value measured by the biological measurement means is greater than or equal to the predetermined value, the assist force for balance compensation is calculated and based on the assist force The control command calculation means outputs a control command to the power generator.

  According to the control device of the walking assist device according to the present invention, the biological state value becomes equal to or greater than the predetermined value due to the posture of the device user becoming unbalanced, and the gravity center position of the device user is abruptly increased. When it changes, balance compensation control is performed, and balance compensation control is not performed more than necessary.

In the walking assist device control device according to the present invention, preferably, the assist force calculating means calculates the position of the center of gravity calculated by the foot position estimating / center of gravity position calculating unit by the foot position estimating / center of gravity position calculating unit. When the distance between the estimated positions of the left and right feet deviates outside the specified circular region having a diameter, the assist force for balance compensation is calculated, and the control command calculating means outputs the control command based on the assist force to the power Output to the generator.
According to the control device for a walking assist device according to the present invention, balance compensation control is performed when the position of the center of gravity of the device user deviates from the normal region, and balance compensation control is not performed more than necessary.

  The assist force for balance compensation may increase gradually or stepwise over time. Further, the assist force for balance compensation may be gradually or stepwise increased in accordance with the amount of deviation from the prescribed circle region of the center of gravity position.

  A method for controlling a walking assistance device according to the present invention is a method for controlling a walking assistance device that individually applies a force generated by a power generation device as an assisting force to left and right legs, and acts on the left and right feet of the device user. The floor reaction force is measured separately on the left and right sides, and the assist force that compensates the load balance of the left and right legs of the device user is calculated using the measured value of the floor reaction force, and the power is calculated according to the calculated assist force. The control command value output to the generator is calculated.

  According to the control method of the walking assist device according to the present invention, the assist force that compensates the balance of the load burden on the left and right legs of the device user is calculated using the measured value of the floor reaction force, and according to the calculated assist force. Since the power is output to the power generation device, it is possible to quickly recover that the load balance between the left and right legs has been lost.

  According to the control device of the walking assist device according to the present invention, the assist force for compensating the balance is calculated using the measured value of the floor reaction force acting on the left and right feet of the device user, and the power is generated according to the assist force. Since the control command value to be output to the device is calculated, when the center of gravity of the device user is biased back and forth and left and right due to walking posture, work posture, heavy material transportation, etc., the left and right legs of the device user Control to restore the load balance is performed directly, and it is possible to quickly recover that the load balance of the left and right legs is lost.

  Below, embodiment of the control apparatus of the walking assistance apparatus by this invention is described with reference to FIGS.

  1 to 3 show an embodiment of a walking assistance device to which a walking assistance control device according to the present invention is applied.

  The walking assist device 10 includes a saddle portion 12 on which a device user sits, a left and right thigh link member 14L, 14R, a left and right thigh link member 14L, 14R, and a left and right lower leg link member 16L, 16R. And shoe portions 18L and 18R worn by the user of the apparatus.

  A hinge shaft 20 extending in the front-rear direction is attached to the center of the lower bottom portion of the saddle portion 12. Left and right arc guide bars 24L and 24R extending in the front-rear direction by brackets 22L and 22R are attached to the hinge shaft 20 so as to be rotatable in the left-right direction about the hinge shaft 20 (can be opened).

  Sliders 26L, 26R are provided on the left and right arc guide bars 24L, 24R so as to be movable along the guide bars by guide rollers 28L, 28R. Left and right base plates 30L, 30R are attached to the sliders 26L, 26R. As a result, the left and right base plates 30L and 30R are guided by the arc guide bars 24L and 24R, and can swing in the front-rear direction.

  The base plates 30L and 30R extend rearward from the fixed portions with the sliders 26L and 26R. The upper ends of the left and right thigh link members 14L, 14R are fixedly connected to the base plates 30L, 30R.

  The hinge shaft 20, the left and right arc guide bars 24L and 24R, the left and right sliders 26L and 26R, and the left and right base plates 30L and 30R are located at positions corresponding to the left and right hip joints of the user of the device. Left and right first joint mechanism portions L1 and R1 capable of moving equivalent to the hip joints are configured.

  The left and right thigh link members 14L, 14R extend obliquely downward and forward from the rear side of the base plates 30L, 30R. The upper end portions of the left and right lower leg link members 16L, 16R are connected to the distal end portions (lower end portions) of the left and right thigh link members 14L, 14R by substantially horizontal pivots 32L, 32R so as to be rotatable in the substantially vertical direction. Shoe portions 18L and 18R are connected to substantially horizontal pivots 34L and 34R so as to be rotatable in a substantially vertical direction at lower ends of the left and right lower leg link members 16L and 16R.

  The pivots 32L and 32R are located at positions corresponding to the left and right knee joints of the device user, and form the left and right second joint mechanism portions L2 and R2 that can move equivalent to the human knee joint. The pivots 34L and 34R are located at positions corresponding to the left and right ankle joints of the device user, and form the left and right third joint mechanism portions L3 and R3 that can move equivalent to the human ankle joint.

  Left and right electric motors 36L and 36R are attached to the left and right base plates 30L and 30R as power generation devices. The left and right electric motors 36L and 36R are assist force generation sources, and output pulleys 40L and 40R are attached to the output shafts 38L and 38R.

  Driven pulleys 42L and 42R are attached to the pivots 32L and 32R. Endless belts 44L and 44R are wound around the output pulleys 40L and 40R and the driven pulleys 42L and 42R, respectively. By this transmission mechanism, the rotational outputs of the left and right electric motors 36L, 36R are individually transmitted to the left and right pivots 32L, 32R forming the left and right second joint mechanism portions L2, R2. That is, the forces generated by the left and right electric motors 36L and 36R are individually applied as assist forces (joint moments ML and MR) to the left and right leg portions (knee joint portions).

  The walking assist device 10 includes a battery power source (not shown) that supplies power to the left and right electric motors 36L and 36R, and a control device 100 (see FIG. 4) that controls the operation of the left and right electric motors 36L and 36R. Yes. The walking assist device 10 includes, as sensors for detecting various physical quantities, rotary encoders 50L and 50R for detecting the rotation angles of the left and right electric motors 36L and 36R, and an MP sensor 52L for measuring the floor reaction force of the left and right legs. , 52R and heel sensors 54L and 54R, a crotch opening angle sensor 56 for measuring the crotch opening angle, support force sensors 60L and 60R for measuring a supporting force of the left leg and the right leg, and swing movement positions of the base plates 30L and 30R Base plate position sensors 62L and 62R for measuring the above are attached.

  The left and right MP sensors 52L and 52R are multi-axis (at least two axes in the vertical direction and horizontal direction) force sensors, and the MP joint (medium joint joint) of the device user wearing the left and right shoe portions 18L and 18R. The floor reaction force is measured by placing it in the shoe at a position almost corresponding to the part.

  The left and right heel sensors 54L and 54R are multi-axis (at least two axes in the vertical direction and horizontal direction) force sensors, and are positioned substantially corresponding to the heel portions of the device user wearing the left and right shoe portions 18L and 18R. It is placed in the shoe and measures the floor reaction force.

  The crotch opening angle sensor 56 detects the opening angle of the left and right brackets 22L and 22R as the crotch opening angle of the apparatus user at the hinge shaft 20 portion.

  The left leg and right leg support force sensors 60L and 60R are multi-axis (at least two axes in the vertical and horizontal directions) force sensors, and are attached to the lower ends of the crus link members 16L and 16R. The supporting force acting on 16R is measured. The supporting force measured by the supporting force sensors 56L and 56R is a physical quantity that correlates with the floor reaction force.

  The base plate position sensors 62L and 62R are attached to the sliders 26L and 26R and measure the swing movement positions of the base plates 30L and 30R from the rotation amounts of the guide rollers 28L and 28R.

  As shown in FIG. 4, the control device 100 includes signals from the sensors described above, and an electromyograph, a heart rate sensor, a respiration sensor, and a sweating amount worn by the device user (walking assisting device wearer). A signal indicating myoelectric potential, heart rate, respiration, sweating, etc. from a biosensor 58 (see FIG. 4) such as a sensor, and a signal indicating the angular velocity of the waist and chest with respect to the vertical direction from the waist / chest gyro sensor 64 A signal indicating acceleration of the waist and chest in the vertical and horizontal directions is input from the chest acceleration sensor 66, and further, worker / work content specification information is input, and the left and right electric motors 36L, The operation of 36R is individually controlled.

  The control device 100 is of an electronic control type including a microcomputer, and implements a floor reaction force calculation unit 102, an assist force calculation unit 104, and a control command calculation unit 106 by executing a computer program.

  The floor reaction force calculation unit 102 inputs sensor signals from each of the MP sensors 52L and 52R and the heel sensors 54L and 54R, or inputs the sensor signals of the supporting force sensors 60L and 60R to the left and right feet of the device user. Acting floor reaction forces FL and FR are calculated separately on the left and right. In this embodiment, a floor reaction force measuring means is configured by force sensors such as the MP sensors 52L and 52R, the heel sensors 54L and 54R, the supporting force sensors 60L and 60R, and the floor reaction force calculation unit 102.

The assist force calculation unit 104 includes a foot position estimation / gravity center position calculation unit 110, a balance compensation assist force calculation unit 112, and a normal walking assist force calculation unit 114.

The foot position estimation / gravity center position calculation unit 110 calculates the left and right floor reaction forces FL, FR or support force calculated by the floor reaction force calculation unit 102 based on the measured values of the MP sensors 52L, 52R and the heel sensors 54L, 54R. The center-of-gravity position C of the device user is calculated using the supporting force acting on the crus link members 16L and 16R measured by the sensors 60L and 60R.

  The foot position estimation / gravity center position calculation unit 110 calculates the bending angles of the left and right second joint mechanism portions L2 and R2 from the rotation angles of the left and right electric motors 36L and 36R detected by the rotary encoders 50L and 50R. The front / rear stride Sy (see FIG. 6) is calculated from the angle and the swing movement position of the base plates 30L and 30R measured by the base plate position sensors 62L and 62R, and from the crotch opening angle of the device user detected by the crotch opening angle sensor 56. The left and right foot interval Sx (see FIG. 6) is calculated. Then, the coordinate position relationship between the estimated position (Rx, Ry) of the right foot position and the gravity center position C is calculated from the left and right floor reaction force measurement values FL and FR, the front and rear step length Sy, and the left and right foot interval Sx according to the following equation. To do.

Rx = {FL / (FL + FR)} Sx
Ry =-{FR / (FL + FR)} Sy

The coordinate position relationship between the estimated position (Lx, Ly) of the left foot position and the gravity center position C can be calculated by the following equation.
Lx =-(Sx-Rx)
Ly = Sy-Ry
Here, x · y is an orthogonal biaxial coordinate having the center of gravity C as the coordinate origin, x is a coordinate value in the left-right direction, and y is a coordinate value in the front-rear direction.

  The balance compensation assist force calculation unit 112 is based on the coordinate position relationship between the estimated position (Rx, Ry) of the foot position and the center of gravity position C obtained by the foot position estimation / position calculation unit 110, and the load burden on the left and right legs. The left and right assist force that compensates for the balance is calculated.

  The normal walking assist force calculation unit 114 calculates the left and right assist forces suitable for normal walking based on the rotation angles of the left and right electric motors 36L and 36R detected by the rotary encoders 50L and 50R.

  FIG. 7 schematically shows changes in the left and right floor reaction forces and the position of the center of gravity before and after the device user holds the luggage W in the illustrated posture. In FIG. 7, symbols FL and FR indicate the left and right floor reaction force measurement values before holding the load W, symbols FLw and FRw indicate the front and left floor reaction force measurement values after holding the load W, and symbol C indicates the load. The center-of-gravity position before having W, and the symbol Cw indicates the position of the center of gravity after holding the load W.

  The fact that the position of the center of gravity changes from C to Cw by having the luggage W can be grasped by the fact that the left and right floor reaction force measurement values change from FL to FLw and FR to FRw by having the luggage W. The center-of-gravity position Cw after holding the load W can be calculated from the left and right floor reaction force measurement values FLw and FRw.

Usually walking assist force calculation unit 114, for example, the waist portion-chest waist gyro sensor 64 from the measured device user, the angular velocity with respect to the vertical direction of the chest, waist, chest accelerometer 66 waist measured device user from The joint moments ML and MR acting on the knee joint of the device user are estimated from the left and right floor reaction force measurement values FL and FR by the inverse kinematic model using the vertical and horizontal accelerations of the chest, and this joint moment. A prescribed ratio of the vertical components of the left and right legs of the walking is determined so that ML and MR become target moments set in advance as parameters, and left and right assist forces suitable for normal walking are calculated based on the prescribed ratio.

  The joint moment ML and MR estimation calculations based on the inverse kinematics model are based on the equations related to translational motion of the lower limbs of the device user and the motion equations related to rotational motion, similar to the calculation of the joint moment of the bipedal mobile body. The moment acting on the corresponding joint in order from the joint closest to the floor reaction force acting point is obtained. If a detailed explanation of this inverse kinematic model is necessary, refer to Japanese Patent Application Laid-Open No. 2003-89083.

  The assist force calculation unit 104 only determines the balance compensation assist force when the changes per unit time of the left and right floor reaction force measurement values FL and FR are not less than a predetermined value, that is, when the center of gravity of the device user changes rapidly. The calculation unit 112 calculates the assist force for balance compensation of the load burden on the left and right legs, and the normal walk assist force calculation unit 114 calculates the left and right assist forces at other times. The assist force (control target value) for balance compensation may be a value correlated with FLw−FL = ΔFL in the example shown in FIG.

  The control command calculation unit 106 individually calculates the left and right control command values to be output to the drive circuits 48L and 48R of the left and right electric motors 36L and 36R according to the left and right assist forces calculated by the assist force calculation unit 104. .

Thereby, when the change per unit time of the left and right floor reaction force measurement values FL and FR becomes a predetermined value or more, the assist force that compensates the balance of the load burden of the left and right legs based on the center of gravity position C with respect to the estimated position of the foot. (Unloading force) is calculated, and control command values to be output to the left and right electric motors 36L and 36R are calculated according to the assist force. In the case of an unbalanced state that is biased to the left and right, it is possible to quickly recover that the load balance between the left and right legs has been lost.

  By this control, it is possible to reduce the physical load on an operator who has a heavy object during work, and to improve work efficiency and production efficiency.

  At the time of balanced normal walking, the normal walking assist force calculation unit 114 calculates and sets the left and right assist forces suitable for normal walking, so that appropriate walking assistance during normal walking is performed.

  As described above, the changes per unit time of the left and right floor reaction force measurement values FL and FR are greater than or equal to a predetermined value, that is, the center of gravity of the device user changes abruptly, and the center of gravity of the device user changes to the proper position. Only when it is in a state to be returned, control is performed to return the device user's center of gravity to an appropriate position in a pseudo manner, and control is performed to compensate for the balance of the load load on the left and right legs of the device user more than necessary. It will never be. Thereby, the control which compensates the balance of the load burden of the left and right legs and the control which does not disturb normal walking are compatible.

  Note that the assist force calculation unit 104 has a predetermined change in the left and right floor reaction force measurement values FL and FR per unit time and a predetermined biological state value such as an electric muscle and a heart rate measured by the biological sensor 58. Only when the value is greater than or equal to the value, the balance compensation assist force calculating unit 112 may calculate the balance compensation assist force, and in other cases, the normal walking assist force calculating unit 114 may calculate the left and right assist forces.

  In this case, in addition to the fact that the changes per unit time of the left and right floor reaction force measurement values FL and FR have become equal to or greater than a predetermined value, the apparatus user's posture is unbalanced. Only when the biological state value of the user becomes equal to or greater than a predetermined value, control for compensating the load balance of the left and right legs of the device user is performed, and control for compensating the balance more than necessary may be performed. Absent. Thereby, the control which compensates the balance of the load burden of the left and right legs and the control which does not disturb the normal walking are more strictly compatible.

  It should be noted that the floor reaction force measurement value FL, which controls the balance of the load burden on the left and right legs of the device user, the threshold value of the change in FR per unit time, and the threshold value of the measurement value of the biological state value are determined by the operator / work What is necessary is just to input content specific information and to set to an appropriate value according to a worker, according to the work content, etc.

  Next, the control routine of the control device for the walking assist device according to the present embodiment will be described with reference to the flowchart shown in FIG.

  First, as worker identification processing, ID information including worker physique / physical strength information, work process, work content, work history, etc. is input (step S101). Next, as work / process identification processing, work / process information such as a work place and a tool such as a carriage is input (step S102).

  Next, sensor signals are input from the rotary encoders 50L and 50R, the MP sensors 52L and 52R, the heel sensors 54L and 54R, the crotch opening angle sensor 56, and the biosensor 58 (step S103).

  Next, it is determined whether or not the measurement value of the biological sensor 58 is equal to or greater than a threshold value (step S104). This threshold value may be variably set to an appropriate value based on ID information and work / process information.

  If the measured value of the biological sensor 58 is not equal to or greater than the threshold value, the assist force is calculated by the normal walking assist force calculation unit 114 (step S105).

If the measured value of the biosensor 58 is equal to or greater than the threshold value, the floor reaction force calculation unit 102 calculates the floor reaction forces (measured values) FL and FR (step S106).

  Next, the coordinate position relationship between the estimated foot position and the gravity center position is calculated by the foot position estimation / gravity position calculation unit 110 (step S107).

  Next, it is determined whether or not the amount of change per unit time of at least one of the floor reaction force measurement values FL and FR is equal to or greater than a predetermined value (threshold value) Fc (step S109). The predetermined value Fc may also be variably set to an appropriate value based on the ID information and work / process information.

  When the amount of change per unit time of the floor reaction force measurement values FL and FR is not equal to or greater than the predetermined value Fc, the assist force is calculated by the normal walking assist force calculation unit 114 (step S105).

  If the amount of change per unit time of at least one of the floor reaction force measurement values FL and FR is equal to or greater than the predetermined value Fc, then the floor reaction force measurement value FL of the left foot is calculated from the floor reaction force measurement value FR of the right foot. It is determined whether or not it is larger (step S109). If FL> FR, a calculation is performed to increase the assist force of the left foot to compensate for the load balance of the left and right legs (step S110).

  On the other hand, if FL> FR is not satisfied, it is determined whether or not the floor reaction force measurement value FR of the right foot is larger than the floor reaction force measurement value FL of the left foot (step S111). If FR> FL, a calculation is performed to increase the assist force of the right foot to compensate for the load balance of the left and right legs (step S112).

  If FR> FL is not satisfied, that is, if FR = FL, the current assist force is maintained (step S113). When FR = FL and FR and FL increase from the previous values, the assist force may be increased at a constant ratio.

  When the assist force is set in any one of steps S105, 110, 112, and 113, the motor command value is calculated accordingly and the motor command is output to the drive circuits 48L and 48R of the left and right electric motors 36L and 36R. (Step S114).

  With the above control, when the front / rear / right / left balance of the worker who is equipped with the walking assist device 10 is lost during work or transportation of heavy objects, the assist force of the foot on the side where the center of gravity is biased is increased. Immediately recovers from the loss of the load balance between the left and right legs.

  It is preferable that the increase in the assist force is performed with such a degree that both the quick recovery from the loss of balance and the user's uncomfortable feeling due to the sudden increase in the assist force are achieved.

In order to satisfy this, the assist force for balance compensation gradually increases linearly with a certain time constant, for example, as shown by the characteristic line A in FIG. As shown, it increases by drawing a quadratic curve, and may increase stepwise as shown by the characteristic line J in FIG. In this case, the time T required for the assist force to reach the control target value from zero may be variably set according to the amount of change per unit time of the floor reaction force measurement values FL and FR.

  As another embodiment, the assist force calculation unit 104 calculates the foot position estimation / gravity position calculation so that the barycentric position calculated by the foot position estimation / gravity position calculation unit 110 is indicated by a symbol Cw in FIG. The balance compensation assist force is calculated only when the distance D of the estimated distance between the left and right foot positions calculated by the unit 110 deviates from the prescribed circle region E, and a control command based on the assist force is issued. The control command calculation unit 109 may output to the drive circuits 48L and 48R of the left and right electric motors 36L and 36R.

  FIG. 8 is a flowchart of the control routine of this embodiment. The difference from the flowchart of FIG. 5 described above is that, in step S108, it is determined whether or not the position of the center of gravity is within a prescribed circular area having a diameter that is the distance between the estimated positions of the left and right feet. If the position of the center of gravity is within the prescribed circle region E, the assist force is calculated by the normal walking assist force calculation unit 114 (step S105). On the other hand, if the position of the center of gravity is not within the prescribed circle region, steps S109 to S113 are executed to calculate an assist force for compensating the load balance between the left and right legs.

  Therefore, even in this embodiment, when the front / rear / left / right balance of the worker who is equipped with the walking assist device 10 is lost during work or transportation of heavy objects, the assist force of the foot on the side where the center of gravity is biased is reduced. Increased, it is possible to quickly recover that the load balance between the left and right legs is lost.

  Also in this embodiment, the increase in assist force may be performed with a degree of achieving both a quick recovery from the loss of balance and a sense of incongruity to the user due to a sudden increase in assist force. preferable.

  In order to satisfy this, for example, the application of assist force for balance compensation is started when the position of the center of gravity exceeds the prescribed circle area E or when the position of the center of gravity starts to approach the outline of the prescribed circle area E. 9 may be increased gradually or stepwise with the characteristics shown by the characteristic lines A to C in FIG.

  Further, as shown in FIG. 10, the assist force for balance compensation is gradually increased linearly as shown by the characteristic line F in accordance with the deviation amount from the prescribed circle region E at the center of gravity. As shown by the characteristic line G in FIG. 10, it may be increased by drawing a quadratic curve, and may be increased stepwise as shown by the characteristic line H in FIG.

It is a perspective view showing an outline of one embodiment of a walk auxiliary device to which a control device by the present invention is applied. It is a side view showing one embodiment of the walking auxiliary device to which the control device by the present invention is applied. It is a front view which shows the principal part of one Embodiment of the walking assistance apparatus with which the control apparatus by this invention is applied. It is a block diagram which shows one Embodiment of the control apparatus of the walk assistance apparatus by this invention. It is a flowchart which shows one Embodiment of the control routine which the control apparatus of the walk assistance apparatus by this invention performs. It is a graph which shows the relationship between foot position estimation and a gravity center position in the control apparatus of the walk assistance apparatus by this invention. It is explanatory drawing which shows the change of the floor reaction force of the right and left and the change of a gravity center position before and after a device user holds a baggage schematically, (a) is a side view, (b) is a front view. is there. doing. It is a flowchart which shows other embodiment of the control routine which the control apparatus of the walk assistance apparatus by this invention performs. It is a graph which shows an example of the assist force control characteristic for balance compensation in the control device of the walk auxiliary device by the present invention. It is a graph which shows the other example of the assist force control characteristic for balance compensation in the control apparatus of the walk assistance apparatus by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Walking assistance apparatus 12 Saddle part 14L, 14R Thigh link member 16L, 16R Lower leg link member 18L, 18R Shoe part L1, R1 1st joint mechanism part L2, R2 2nd joint mechanism part L3, R3 3rd joint mechanism part 36L, 36R electric motor 50L, 50R rotary encoder 52L, 52R MP sensor 54L, 54R heel sensor 56 crotch opening angle sensor 58 biosensor 100 control device 102 floor reaction force calculation unit 104 assist force calculation unit 106 control command calculation unit 110 foot position estimation / Center of gravity position calculation unit 112 Balance compensation assist force calculation unit 114 Normal walking assist force calculation unit

Claims (7)

A control device for a walking assistance device that individually gives the power generated by the power generation device as an assist force to the left and right legs,
A floor reaction force measurement unit that individually measures the floor reaction force acting on the left and right feet of the device user;
A foot position estimation / gravity position calculation unit that calculates the positional relationship between the estimated position of the left and right feet of the device user and the gravity center position of the device user using the floor reaction force measured by the floor reaction force measurement unit;
Compensate for an imbalance in the load burden on the left and right legs based on the positional relationship between the estimated position of the left and right feet of the device user and the position of the center of gravity of the device user calculated by the foot position estimation / gravity position calculation unit. A balance compensation assist force calculator that calculates the assist force of the left and right legs,
A control command calculation unit that calculates left and right individual control command values to be output to the power generation device according to the assist force calculated by the balance compensation assist force calculation unit ;
A control device for a walking assist device. Said balance compensation assist force calculation section centroid position calculated by the foot position estimation-center-of-gravity position computing unit, a diameter the distance of the estimated position of each foot which is calculated by the foot position estimation-center-of-gravity position computing unit 2. The walking assist according to claim 1 , wherein the assist force for balance compensation is calculated and the control command calculation unit outputs a control command based on the assist force to the power generator when the vehicle departs from a circular region. Control device for the device. The walking assist device control device according to claim 1 , wherein the assist force for balance compensation is gradually or stepwise increased. The walking assist device control device according to claim 3 , wherein the assist force for balance compensation is gradually or stepwise increased in accordance with a deviation amount of the center of gravity position out of the circular region . Said balance compensation assist force calculation unit, when the amount of change per unit time has been floor reaction force measured by the floor reaction force measuring unit is a predetermined value or more, claim 1 for computing the assist force balance compensation The control device for a walking assist device according to any one of claims 4 to 4 . It has a biological measurement unit that measures the biological state value of the device user,
It said balance compensation assist force calculation unit, the change per unit time of the floor reaction force measured by the floor reaction force measuring unit is above a predetermined value, and the biological condition value measured by the biometric unit is greater than a predetermined value of only if, calculates the assist force balance compensation, the control command based on the assist force the control command calculation unit according to any one of claims 1 to 5 to be output to the power generating device Control device for walking assist device. A control method for a walking assist device that individually gives the power generated by the power generation device as an assist force to the left and right legs,
Measure the floor reaction force acting on the left and right feet of the device user separately,
Calculate the positional relationship between the estimated position of the left and right feet of the device user and the center of gravity of the device user using the measured floor reaction force,
Based on the positional relationship, the left and right leg assist force is compensated to compensate for the imbalance in load balance between the left and right legs, and the control command value output to the power generator is calculated according to the calculated assist force. To control the walking assist device.

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