JP2013043055A - Walking assist device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a footwear type walking assist device capable of improving a walking ability by being used as an assistance to a bipedal walking ability.SOLUTION: The walking assist device includes a crawler 1 for a right foot and a crawler 1 for a left foot. Each crawler 1 includes: a base 2 where a sole is mounted; a travel mechanism comprised of one or a plurality of rolling elements 5 which are arranged at the rear face side of the base 2 and make the base 2 travel along a road surface; a drive mechanism which drives the travel mechanism; a first measuring means which is arranged at the base 2 and measures a speed of the base during bipedal walking; and a second measuring means which is arranged along the surface of the base 2 and measures a pressure received from the sole at a plurality of points. Bipedal walking is assisted by controlling the travel speed of the travel mechanism arranged at each crawler through the use of a control means.

Description

  The present invention relates to a walking assistance device that includes a pair of left and right footwear that should be worn on both feet during biped walking, and that can reduce the burden on a pedestrian during walking.

  2. Description of the Related Art Conventionally, as a device for assisting bipedal walking, a device that directly assists the movement of a person's foot with an exoskeleton-type apparatus main body that is worn on a person's lower limb is commonly used (see, for example, Patent Document 1). .

  In addition, many coaxial two-wheeled vehicle-type devices that carry a person and have a vehicle-type device body on which a person can ride have been proposed (see, for example, Patent Documents 2, 3, 4, and 5).

  Furthermore, a walking aid has been proposed that reduces the size of a vehicle-type device body to the size of a roller skate and brakes the device body in accordance with the inclination angle of a foot attached to the device body (Patent Document). 6).

JP 2010-077548 A US Patent No. 005971091 JP 2004-345030 A JP 2005-1554 A Japanese Patent Laid-Open No. 2005-94898 JP 2004-275525 A

  However, the conventional walking assistance device has a problem in that the system is large and expensive in a system that directly assists the movement of a human leg. In addition, the device realized with a simple configuration has a problem that assistance in consideration of human walking motion is insufficient.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a footwear type walking assist device that can be used for assisting a biped walking function to improve walking ability.

  A walking assistance device according to the present invention includes a foot for a right foot and a foot for a left foot, and each foot is provided on a base portion on which a sole is to be placed, and on the back side of the base portion. A traveling mechanism composed of one or a plurality of rolling elements for traveling the base portion along the road surface, a driving mechanism for driving the traveling mechanism, and a speed of the base portion disposed on the base portion during biped walking. A first measuring means for measuring, and a second measuring means for measuring the pressure received on the surface of the base portion and received from the sole at a plurality of points, and the traveling speed of the traveling mechanism disposed on each footwear. The control means assists biped walking by controlling the speed information obtained from the first measuring means for the foot that is away from the road surface during biped walking, and the road surface. Pressure obtained from the second measuring means on the landing foot Based on the information, the periodic walking state is an acceleration period in which the traveling speed should be accelerated in the period until the foot landing on the road leaves the road surface, or the constant speed period in which the traveling speed should be maintained at a constant speed Or a deceleration period in which the traveling speed should be reduced, and a control signal for the drive mechanism is generated according to the determination result.

In biped walking, a person walks by repeatedly accelerating and decelerating for each step, and during the period when both feet landed, both acceleration and deceleration are possible, and speed adjustment just before shifting to the one-leg support state is performed . Also, the first half of the period when only one foot has landed is a period during which the walking speed is reduced until the center of gravity of the entire body passes immediately above the support leg. In addition, when the center of gravity of the whole body is located directly above the support leg, it is impossible to instantaneously accelerate or decelerate in the traveling direction, and the weight is evenly applied to the entire sole to support the weight. is there. Thereafter, during the second half of the period when only one foot has landed, the foot is kicked backward from a state where the weight is evenly applied to the entire sole, and a forward driving force is generated, so the walking speed is accelerated.
In order to assist walking without interfering with the natural walking state of the person, acceleration is supported in the acceleration state where the foot is kicked backward, and one foot is ahead of the trunk and the trunk is in the deceleration state immediately after that. It is preferable to assist the deceleration in the deceleration state with one foot support.

  According to the walking assist device of the present invention, during bipedal walking, the pedestrian kicks the road surface backward with the foot from the state where one foot is landed forward, and the foot is separated from the road surface. Whether it is an acceleration period in which periodic walking accelerates, a constant speed period in which periodic walking maintains a constant average speed, or a deceleration period in which periodic walking decelerates It is accurately determined on the basis of the speed of the foot (free leg) that is present and the pressure received from the foot landing on the road surface.

  And if it is determined as the acceleration period according to the discrimination of the acceleration period, constant speed period, and deceleration period in the periodic walking during biped walking, it is supported with one foot during periodic walking with respect to the drive mechanism. When the acceleration control signal is supplied and the constant speed period is determined, the control signal for maintaining the constant speed is supplied to the drive mechanism and the deceleration period is determined. In some cases, a deceleration control signal is supplied to the drive mechanism when the two-foot support state or the deceleration state during periodic walking is present. Accordingly, the driving mechanism performs driving for acceleration, constant speed maintenance, or deceleration to operate the traveling mechanism. In the case where there is no special control signal instruction, it is assumed that a constant speed maintaining signal for maintaining the previous speed is supplied.

  In a specific aspect, the control means is based on the speed information obtained from the first measurement means, and whether the moving speed of the foot away from the road surface during biped walking is increased or decreased from a reference value Based on the pressure information obtained from the second measuring means and the pressure information obtained from the second measuring means, the moving speed of the center of the pressure received from the foot landing on the road surface during biped walking is larger or smaller than the reference value Whether the pressure received from the foot landing on the road surface during biped walking is greater than the reference value on the heel side based on the second determination for determining whether or not and the pressure information obtained from the second measuring means By performing the third determination to determine whether the toe side is larger than the reference value, and integrating these three determination results, the acceleration period, the constant speed period and the deceleration period during biped walking are determined. judge.

  In addition, as each reference value in the said 1st, 2nd and 3rd discrimination | determination, the measurement information before 1 period of the cyclic | annular movement of each leg during biped walking is employ | adopted, and there is a significant difference? Is judged.

Further, in a specific aspect, the control means integrates the three discrimination results by non-hierarchical clustering using a K-average method.
The control means determines the acceleration period, the constant speed period, and the deceleration period during biped walking by sequentially learning by the non-hierarchical clustering.

  In a more specific aspect, as far as the first determination result is concerned, the control means is substantially in the acceleration period when the moving speed of the foot away from the road surface during biped walking is increased. When it is constant, it is determined that it is a constant speed period, and when the movement speed is decreasing, it is determined that it is a deceleration period.

  In addition, as far as the second determination result is concerned, the control means, when the moving speed at the center of the pressure received from the foot landing on the road surface during biped walking is larger than the reference value, the moving speed Is smaller than the reference value, it is determined that the vehicle is in the deceleration period.

  In addition, as far as the third determination result is concerned, the control means, when the pressure received from the foot landing on the road surface during biped walking is higher than the reference value on the toe side, the acceleration period, When the pressure is higher than the reference value on the heel side, it is determined that the vehicle is in the deceleration period.

  According to the walking assist device of the present invention, a pedestrian who is walking on two legs lands one of the feet on the road surface, then kicks the road surface with that foot and takes a step forward. If the periodic walking is in the deceleration period when walking naturally without walking, if the trunk is behind the grounded leg in the two-leg supporting state or one-leg supporting state during periodic walking, the traveling mechanism is decelerated and periodically When the normal walking is in the constant speed period, the running mechanism maintains a constant speed, and when the periodic walking is in the acceleration period, the trunk is in front of the grounded leg in the single-leg support state during periodic walking. Accelerates the traveling mechanism, and when this deceleration, constant speed maintenance and acceleration walks naturally, periodic acceleration and deceleration are performed alternately with the left and right feet by the determination of constant speed, and the determination result Corresponding to the traveling machine in the acceleration state and deceleration state during periodic walking For the acceleration of the deceleration, pedestrians can walk at a faster rate than that at the time of the natural gait while walking which is not the same as when the natural walking, it is possible to improve the walking ability.

FIG. 1 is a side view of a walking assist device according to an embodiment of the present invention. FIG. 2 is a diagram illustrating an arrangement of a plurality of pressure sensors in the walking assistance device. FIG. 3 is a flowchart showing a control procedure in the walking assistance device. FIG. 4 is a block diagram illustrating motor speed control. FIG. 5 is a graph showing the time change of the speed of the leg on the free leg side. FIG. 6 is a graph showing the time change of the center position of the pressure distribution received from the sole. FIG. 7 is a graph showing a temporal change in pressure measured by a pressure sensor arranged on the toe side. FIG. 8 is a graph showing the temporal change in pressure measured by the pressure sensor arranged on the heel side. FIG. 9 is a diagram showing a state transition of one footwear in a walking cycle. FIG. 10 is a diagram illustrating a state of bipedal walking using the walking assist device. FIG. 11 is a diagram for explaining a state of bipedal walking.

Next, embodiments of the present invention will be specifically described with reference to the drawings.
As shown in FIG. 1, a walking assist device according to an embodiment of the present invention includes a footwear 1 to be worn on each of both feet, and the footwear 1 includes a base portion 2 on which a sole is to be placed. Yes. On the back side of the base portion 2, there are provided four front and rear left and right wheels 5 attached to both ends of two front and rear axles 6, and an auxiliary wheel 7 rotatably supported by an axle 8 on the front end. Is deployed.

  In addition, an acceleration sensor / gyro sensor 12 and a contact sensor 11 for detecting a state where the auxiliary wheel 7 has landed on the road surface 9 are arranged on the back surface of the base portion 2.

  A plurality of pressure sensors 4 are distributed and arranged on the surface of the base portion 2, and these pressure sensors 4 are covered with a sheet 3. A fastening belt 10 for restraining a foot on the seat 3 is attached to the surface of the base portion 2.

  As shown in FIG. 2, the plurality of pressure sensors 4 include a first region 13 corresponding to the thumb of the foot on the base portion 2, a second region 14 corresponding to the base of the thumb joint, and a base of the ring finger joint. One each is arranged in the corresponding third region 15 and the fourth region 16 corresponding to the heel.

  Each of the two axles 6 shown in FIG. 1 is connected to a servo motor (not shown), and the motor is rotationally driven in the forward direction by a speed control signal from a control circuit (not shown). The rotational speed of the motor is detected by a rotary encoder (not shown).

  Signals from the pressure sensor 4, the acceleration sensor / gyro sensor 12, the contact sensor 11, and the rotary encoder are supplied to the control circuit, and in response thereto, the control circuit generates a speed control signal.

FIG. 3 shows a control procedure by the control circuit.
When walking is started, sensor information is first acquired in step S1, and the sensor information is compared with the information storage unit in step S2. Here, the information storage unit stores sensor information in natural walking without walking assistance and past sensor information when walking assistance is performed.

  Next, at step S3, the information storage unit is updated with the acquired sensor information, and at step S4, acceleration / deceleration described later is performed. Here, when deceleration is determined, a deceleration command is issued in step S5. When a constant speed is determined, a constant speed maintenance command is issued in step S6. If acceleration is determined, an acceleration command is issued in step S7.

  Subsequently, after gain adjustment is performed in step S8 to generate an angular velocity command for the motor, in step S9, the rotational speed of the motor is controlled in accordance with the angular velocity command. Thereafter, in step S10, it is determined whether or not walking is completed. If no, the process returns to step S1 and the same procedure is repeated. If it is determined as YES in step S10, the walking control is terminated.

FIG. 4 shows the motor speed control in step S9.
First, in step S11, the angular velocity command is integrated to calculate the target position. Next, in step S12, a speed command is generated by PID control. In step S13, a speed command is supplied to the servo motor. In step S14, the rotation of the servo motor is transmitted to the rotary encoder, and the rotation angle of the motor is measured.

  In the PID control, as a position error, a difference between a target position obtained by integrating angular velocity commands and a current position calculated from a rotation angle measured by an encoder is calculated. Further, as the speed error, the difference between the angular speed command and the angular speed measured from the rotation angle difference measured by the encoder is calculated.

Hereinafter, the acceleration / deceleration determination to be executed in step S4 of FIG. 3 will be described.
First, based on FIG. 11, deceleration and acceleration during periodic walking in biped walking will be described. In biped walking, a both-leg supporting period in which the weight is supported by both legs and a one-leg supporting period in which the weight is supported by one leg are alternately repeated.

  In biped walking, a person walks by repeatedly accelerating and decelerating for each step, and the two-leg support period is a period in which the speed for shifting to the next one-leg support state is adjusted. In consideration of simplification, it can be determined that the vehicle is in a deceleration state. Also, during the first half of the one-leg support period, the state where the trunk is behind the support legs and the weight is applied to the heel is decelerated until the trunk is positioned directly above the support legs and the weight is applied evenly to the entire sole. It can be determined that After that, in the second half of the one-leg support period, the trunk is positioned in front of the support legs and the weight is evenly applied to the entire sole, and the foot is kicked backward to generate forward thrust, so in the accelerated state It can be determined that there is.

  As shown in FIG. 9, in biped walking with the walking assistance device attached, the front and rear wheels are separated from the road surface 1, the heel side wheels are landed 2, and the front and rear wheels are landed. The weight 3 is evenly applied to the entire sole, the heel side wheel is separated from the road surface and the toe side wheel is landed 4, and the toe side wheel and the front assist are inclined further forward. A state 5 in which the wheel has landed reaches a state 6 in which the wheel on the toe side is separated from the road surface.

  The movement of the walking assistance device shown in FIG. 9 is an example, and the landing posture is possible even when the landing posture is other than the state 2. The situation is information from the pressure sensor 4 and the acceleration sensor / gyro sensor 12. It is possible to judge by. Similarly, the timing at which the front and rear wheels are separated from the road surface is not limited to the sixth state in FIG. 9, and can be determined from information from the pressure sensor 4 and the acceleration sensor / gyro sensor 12.

In order to assist acceleration and deceleration without disturbing the natural walking state of a person, it is preferable to accelerate and decelerate the assisting device in a state where normal walking acceleration and deceleration are performed.
Therefore, in the travel assistance device of the present invention, the periodic walking deceleration period, acceleration period, and constant speed period are determined based on signals obtained from the plurality of pressure sensors 4 and the acceleration sensor / gyro sensor 12. Based on the determination result, control signals for acceleration, deceleration, and constant speed maintenance for the motor are generated in an acceleration state or a deceleration state during periodic walking.

  Specifically, based on the measurement data obtained from the acceleration sensor / gyro sensor 12, the moving speed of the leg on the free leg side away from the road surface during biped walking is increased or decreased from the reference value. The moving speed of the center position of the pressure received from the foot landing on the road surface during biped walking is based on the first determination for determining whether or not the measurement data obtained from the plurality of pressure sensors 4 is higher than the reference value. Based on the second determination to determine whether it is large or small and the measurement data obtained from the plurality of pressure sensors 4, the pressure received from the foot landing on the road surface during biped walking is lower than the reference value on the heel side A third determination is performed to determine whether the increase is greater than the reference value on the toe side.

In the discrimination of human walking acceleration / deceleration using the pressure sensor 4, the pressure center of the sole is calculated from the measured value of each pressure sensor 4. The pressure measured at the toes is larger than the pressure distribution when walking at a constant speed, and the pressure measured at the toes shows a larger value than other foot landing parts during the lifting and acceleration periods. Since the duration of time during which pressure is applied is measured for a long time, acceleration is discriminated.
During the deceleration period, the measurement pressure of the heel is greater than that of the other landing parts, and the heel pressure is greater and the duration is measured than when walking at a constant speed, so deceleration is determined.

  Further, the change in the pressure center is determined as the acceleration period when the time for the pressure center to move to the toe is faster and the ratio of the time for the toe is longer than in the case of constant speed walking. When the time at which the pressure center is maintained near the heel is longer than when walking at constant speed, and when the time for the pressure center to move to the toe is slower than when walking at constant speed, Make a decision.

  In the determination of acceleration / deceleration of a person's walking using the acceleration sensor / gyro sensor 12, the opposite foot when the state of the supporting leg changes from state 1 to state 3 shown in FIG. A state in which the fourth acceleration assistance shown in FIG. 9 is performed based on the acceleration and angular velocity information measured from the acceleration sensor / gyro sensor 12 mounted on the free leg-side footwear 1 during the free leg movement in the air. Calculate the average moving speed and average angular velocity of the free leg until just before entering, compare with the average speed and average angular velocity of one step before, and when it is faster, determine the acceleration period, When the average angular velocity is slower than the average velocity of the previous step and the average angular velocity, it is determined that the vehicle is in the deceleration period.

FIG. 5 shows the time change of the moving speed (swinging speed) of the leg on the free leg side measured by the acceleration sensor / gyro sensor 12. Here, it can be determined that the period during which the speed peak is increasing is the acceleration period, the period during which the speed peak is substantially constant is the constant speed period, and the period when the speed peak is decreasing is the deceleration period.
More specifically, the peak value of the swing speed is compared with the peak value of the swing speed before one walking cycle. When the peak value of the swing speed is significantly higher than the peak value of the swing speed before one walking cycle, acceleration is performed. When the peak value of the swing speed is significantly lower than the peak value of the swing speed before one walking cycle, it can be determined as the deceleration period.

FIG. 6 shows changes in the center position (ZMP: Zero Moment Point) of the sole pressure measured by the plurality of pressure sensors 4 for the right foot and the left foot. The origin (0 mm) on the vertical axis corresponds to the position of the pressure sensor 4d on the heel side, and the pressure distribution transitions toward the position (0.185 mm) of the pressure sensor 4a on the toe side.
In FIG. 6, a section surrounded by a vertical broken line shows the state 3 described in FIG. 9, which is a period from the deceleration to the acceleration in the one-leg support period during walking. Therefore, based on the change in ZMP during this period Acceleration period, deceleration period, constant speed period can be discriminated.

  As is clear from FIG. 6, the ZMP shifts to the toes faster than the other periods during the start acceleration period, and near the heel during the deceleration period after the end of the walk. Is maintained for a long time, and the time for ZMP to transfer to the toe is delayed. Since there is a case where the vehicle decelerates without landing the tiptoe during the deceleration period, the ZMP does not move to the tiptoe. From this result, it can be determined that it is an acceleration period if the time for ZMP to move to the toe is early, and that it is a deceleration period if it is late.

  More specifically, the change in the ZMP includes the maximum value (or the movement time to the toe) until the ZMP moving speed in the current walking cycle becomes a toe standing posture and the maximum of the ZMP moving speed before one walking cycle. The values (or the movement time to the toe) are compared, and if there is a significant difference (greater than a certain threshold value) in the increasing direction, it is determined as an acceleration period. Similarly, a change in ZMP between the current walking immediately before the both foot support period, which is the deceleration period, and the walking one cycle before is compared, and if there is a significant difference in the decreasing direction, it is determined as the deceleration period.

FIG. 7 is a graph showing the time change of the pressure detected by the pressure sensor 4a arranged on the toe side, and FIG. 8 shows the time change of the pressure detected by the pressure sensor 4d arranged on the heel side. It is a graph.
In the acceleration period, it can be confirmed that the pressure detected by the pressure sensor 4a arranged on the toe side is larger than the pressure during walking in other states, and at the time of deceleration, detected by the pressure sensor 4d arranged on the heel side. It can be confirmed that the pressure applied is higher than the pressure during walking in other states, so if the pressure on the toe side is large, it can be determined that it is in the acceleration period, and if the pressure on the heel side is large, it is in the deceleration period Can be determined.

  More specifically, when the pressure on the heel side is measured larger than the maximum pressure before one walking cycle, it is determined as the deceleration period, and when the pressure on the toe side is measured, the acceleration period is determined. Determine.

  However, when the pressure on the heel side is greatly measured, it is a two-foot support period that is already in a deceleration state during periodic walking in natural walking, so it becomes a comparison with the maximum value in the two-foot support period one cycle before. When the maximum pressure on the heel side during the previous two-foot support period exceeds the threshold, it is determined that there is an intention to urgently decelerate. Give instructions. Also, when a large pressure is applied to the toe side even during acceleration, it is often in an accelerated state during periodic walking in natural walking where the toe is already standing, so compared to the maximum toe side pressure one cycle before When it is determined that the current toe side pressure has increased beyond the threshold value, an instruction to accelerate the wheel is given from the middle of the acceleration state where the current toe is standing.

  Then, a first determination based on the swing speed of the foot on the free leg side (FIG. 5), a second determination based on the moving speed of the ZMP (FIG. 6), and a third determination based on the pressure on the heel side and the toe side (FIG. 5). 7 and FIG. 8) are integrated to determine the acceleration period, constant speed period, and deceleration period during bipedal walking.

For the integration of the three discrimination results, sequential learning by non-hierarchical clustering using the K-means method (Naoki Domoto, Ryuta Ozawa: "Development of sequential learning type gait phase discrimination algorithm:", 11th System Integration Division Lecture ( SI 2010) Lecture Proceedings, pp. 217-220, (2010)) is used to determine the acceleration period, constant speed period, and deceleration period during bipedal walking.
Here, the result of the sequential learning is reflected in “update of information storage unit” in step S3 of FIG.

  Let xh be the pressure on the heel side, xt be the pressure on the toe side, xd be the difference in leg swing speed, and xi be ZMP calculated from the sole pressure. Also, assuming that the respective cluster averages are uh, ut, ud, ui, the four-dimensional vector of the value measured at the nth time is xn = [xh xt xd xi] n, and the cluster average is u (j) = [uh ut ud ui]. However, j is divided into three clusters of acceleration, constant speed, and deceleration, and j = 1, 2, 3 is given here. At this time, the result phi clustered from the concept of the K-average method and the cluster average are updated as follows.

phin = argmin (|| xn−u (j) ||) (j = 1, 2, 3)
un (j) = un (j) + f (phin) (xn-un (j))
if j = phin
f (phin) = 0.01
else
f (phin) = 0

  The acceleration / deceleration command (aw) determined from the measurement information of the pressure sensor 4 and the acceleration sensor / gyro sensor 12 is, for example, a pressure change evaluation formula (Vp), a pressure center evaluation formula calculated from the sole pressure ( Vz) and the following formula consisting of the evaluation formula (Vm) of the average velocity of the free leg can be unified and determined.

aw = Kp * Vp + Kz * Vz + Km * Vm
However, Kp, Kz, and Km are weighting factors for combining. Further, the speed Vw of the wheel 5 is set to zero or more, and the acceleration / deceleration aw by the wheel 5 is set so as not to exceed an upper limit at which it is determined that a person does not fall.

According to the walking assist device according to the present invention, the pedestrian can assist in the force of kicking the ground and the walking speed by the rotation control of the wheel 5 provided on the footwear 1, for example, as shown in FIG. In the acceleration period, the kicking force increases as the wheels accelerate, and the stepping distance for one step becomes longer.
Moreover, according to the walking assistance apparatus which concerns on this invention, cost becomes cheap compared with a large-scale apparatus, and a movement capability can be assisted with various users' natural walking.

A walking assistance device can be configured as follows to assist a person's walking.
A motor driver capable of commanding a speed and a DC motor (for example, manufactured by Maxon) are attached to the base portion 2 made of a carbon plate, and the DC motor and the wheel 5 are connected with a belt to drive the wheels 5 before and after FIG. The front and rear wheels 5 are configured to rotate at the same speed.

  As shown in FIG. 2, a thin pressure sensor (Nita Corporation Flexi Force) is installed at the upper part of the base part 2 at the position where the heel part, the left and right of the forefoot part, and the thumb of the toe part come into contact. By attaching a sheet 3 made of a carbon plate to the upper part, pressure information at the time of walking of a person can be read.

In addition, by attaching a motion sensor (ZEP MP IMU-Z Co., Ltd.) that includes a triaxial acceleration sensor and a gyro sensor under the base part 2, the position and inclination of the walking assist device can be measured, It is possible to determine a situation where the vehicle decelerates or a situation where the walking assist device can accelerate and decelerate.
The motor speed control based on the sensor information can be performed by, for example, a microcomputer that can be worn on the body.

  As for the timing of assisting acceleration and deceleration by the wheel 5, when the waist is supported by both feet as shown in the first of FIG. In the second and third states shown in FIG. 9, the person's waist is decelerated because it is located behind the support leg, and in the fourth and fifth states shown in FIG. It is possible to introduce a control that accelerates because the hips are located in front of the support legs, so that acceleration and deceleration by the walking assist device are assisted in synchronization with the walking state of the person. Become.

  Since the pressure sensor 4 and the acceleration sensor / gyro sensor 12 are directly connected to the AD board and measured, it is possible to acquire data with a measurement cycle of 1000 Hz or more, but even with a sampling cycle of about 100 Hz. Measurement at 20 points is possible, and the delay in judgment is about 0.01 seconds, so that the operation is not hindered.

  The value of each sensor is constantly measured, and in each determination, the measurement data is compared with the measurement data of the previous walking cycle. Here, regarding the ZMP moving speed, the maximum value of the ZMP moving speed before one walking cycle (or the time until the ZMP reaches the toe from the heel) is stored and compared with the current walking cycle. For the pressure on the heel side and the toe side, the maximum value of the pressure sensor on the heel and toe before one walking cycle is stored and compared with the value of each pressure sensor in the current walking cycle. As for the swing speed of the swing leg, the maximum value of the swing speed of the foot one cycle before is stored, and the swing speed of the leg in the current walking cycle is compared.

  In addition, in the control at the start of walking, there is no data as a walk one cycle before, so only the measurement is performed until one step is taken, data is accumulated, and one step is taken when the next step (second cycle) is stepped on. While comparing the maximum movement speed of the ZMP of the eye, the maximum value of the pressure on the heel side and the toe side, and the maximum value of the swing speed of the free leg, the wheel is accelerated to the toe standing state 5 which is the acceleration period of the second cycle. Judge what to do.

  In addition, in the control at the end of walking, in addition to the normal determination of deceleration, a method of determining deceleration when the foot position is the same on the left and right can be adopted. It is possible to determine that there is an intention to stop when both feet are aligned. When walking and decelerating gradually, the vehicle is decelerated only by normal deceleration timing control.

Each part configuration of the present invention is not limited to the above embodiment, and various modifications can be made within the technical scope described in the claims.
For example, although the wheel 5 is provided before and after the base part 2 as a rolling element, it is not restricted to this, The base part 2 inclines backward, is in the position which can fully support a weight at the time of landing, and a foot tip The number of wheels 5 and the position thereof are not limited as long as the vehicle can be disposed at a position where the force from the sole can be sufficiently transmitted to the road surface. The wheel 5 can be replaced with an endless crawler belt.

  According to the present invention, it is possible to determine the walking state of a person and control acceleration / deceleration of the walking assist device, particularly when a person with weak physical strength walks a long distance without difficult handling, Walking assistance can be performed easily. In addition, it determines the acceleration period, constant speed period, and deceleration period in natural walking, and moves regardless of walking motion, such as assisting walking to accelerate and decelerate wheels in the accelerated state and decelerated state during periodic walking. Since there is no auxiliary system, accidents during use are unlikely to occur.

DESCRIPTION OF SYMBOLS 1 Footwear 2 Base part 3 Seat 4 Pressure sensor 5 Wheel 6 Axle 7 Auxiliary wheel 8 Axle 9 Road surface 10 Fastening belt 11 Contact sensor 12 Acceleration sensor / gyro sensor

Claims (13)

A foot for right foot and a foot for left foot, each foot is disposed on the back side of the base portion on which the sole is to be placed and runs along the road surface. A traveling mechanism comprising one or a plurality of rolling elements for driving, a driving mechanism for driving the traveling mechanism, a first measuring means that is disposed on the base portion and measures the speed of the base portion during biped walking, Second measuring means that is deployed along the surface of the base portion and measures the pressure received from the sole at a plurality of points, and by controlling the traveling speed of the traveling mechanism disposed on each footwear by the control means A walking assistance device for assisting bipedal walking,
The control means is based on speed information obtained from the first measurement means for a foot away from the road surface during biped walking and pressure information obtained from the second measurement means for a foot landing on the road surface. In the period until the foot that has landed on the road leaves the road surface, it is the acceleration period in which the traveling speed should be accelerated, the constant speed period in which the traveling speed should be maintained at a constant speed, or the deceleration in which the traveling speed should be reduced A walking assistance device that determines whether or not a period is in effect and generates a control signal for the drive mechanism according to the determination result.   The control means determines whether the moving speed of a foot away from the road surface during biped walking is higher or lower than a reference value based on speed information obtained from the first measuring means. And determining whether the moving speed of the center of the pressure received from the foot landing on the road surface during biped walking is larger or smaller than the reference value based on the pressure information obtained from the second measuring means. 2 and whether the pressure received from the foot landing on the road surface during biped walking is higher than the reference value on the heel side based on the pressure information obtained from the second measuring means, or on the toe side The third discrimination for discriminating whether the value is greater than the value is performed, and based on the results of these three discriminations, the acceleration period, the constant speed period, and the deceleration period during biped walking are determined. The walking aid device described.   The walking assistance device according to claim 2, wherein each of the reference values in the first, second, and third determinations is measurement information one cycle before the periodic movement of each foot during biped walking.   The walking assist device according to claim 2 or 3, wherein the determination of the acceleration period, the constant speed period, and the deceleration period is periodically performed in synchronization with a periodic movement of each leg during bipedal walking.   The walking control device according to claim 2, wherein the control unit integrates the three determination results by non-hierarchical clustering using a K-average method.   The walking assist device according to claim 5, wherein the control unit performs determination of an acceleration period, a constant speed period, and a deceleration period during biped walking by sequentially learning by the non-hierarchical clustering.   As far as the first determination result is concerned, the control means has an acceleration period when the moving speed of a foot away from the road surface during biped walking is increasing, and a constant speed period when the moving speed is substantially constant. The walking assistance device according to any one of claims 2 to 6, wherein when the moving speed is decreasing, it is determined that the vehicle is in a deceleration period.   As far as the second determination result is concerned, the control means, when the moving speed at the center of the pressure received from the foot landing on the road surface during biped walking is larger than the reference value, is the acceleration period, and the moving speed is the reference The walking assistance device according to any one of claims 2 to 7, wherein it is determined that the vehicle is in a deceleration period when the value is smaller than the value.   As long as the control means relates to the third determination result, the pressure received from the foot landing on the road surface during biped walking is greater than the reference value on the toe side, the acceleration period, The walking assist device according to any one of claims 2 to 8, wherein when the heel side is larger than a reference value, it is determined that the vehicle is in a deceleration period.   The first measurement unit includes an acceleration sensor and a gyro sensor, and the second measurement unit includes a plurality of pressure sensors. The control unit stores a measurement data obtained from the sensor; A comparison unit that compares data with a human walking model, a learning unit that learns walking motion based on the comparison result, and information obtained from the comparator is determined based on the learning result. The walking assist device according to claim 1, further comprising a control unit that changes the speed.   The walking assist device according to any one of claims 1 to 10, wherein the rolling element is constituted by a wheel or an endless crawler belt. When the acceleration period is determined according to the acceleration period, constant speed period, and deceleration period in periodic walking, which is a natural bipedal state of a person, one leg during periodic walking with respect to the drive mechanism When it is in the acceleration state where the foot is kicked backward by support, an acceleration control signal is supplied, and when it is determined that the constant speed period, a constant speed maintenance control signal is supplied to the drive mechanism, and the deceleration period When the determination is made, a deceleration control signal is supplied when the drive mechanism is in a decelerating state in which the lower back is behind the indicating leg in the both-leg-supporting state during one-step walking or the one-leg instruction. The walking assist device according to claim 11. Depending on the acceleration period, constant speed period, and deceleration period in periodic walking, which is a natural biped walking state of humans, when it is determined as the acceleration period, it is in the drive mechanism other than the acceleration state during periodic walking 13. A control signal for maintaining speed is supplied to the drive mechanism except for a deceleration state during periodic walking when a control signal for maintaining speed is supplied and it is determined that the vehicle is in a deceleration period. The walking assist device according to any one of the above.