JP2012200318A - Walking assist device and walking assist program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform a further energy-saved control in a walking assist.SOLUTION: This walking assist device 1 acquires a whole walking route to a destination and acquires an electric energy required when performing a regular assist based on a walking distance. When a residual amount of a battery 18 is insufficient for the walking assist till reaching the destination, this walking assist device reduces an assist force of a swing leg when the leg is separated from the ground, to reduce a battery consumption and continues the assist to the destination. When a wearer M goes down a slope, a burden applied to the wearer is small, and when comparing the swing leg with a stance leg, the burden of the wearer M is smaller when reducing the assist force of the swing leg. An assist method for keeping a sufficient battery till reaching the destination is selected and executed by reducing the assist force in order of a swing leg in descending, a swing leg walking on a level ground, a stance leg in descending, and a stance leg walking on the level ground.

Description

  The present invention relates to a walking support device and a walking support program, for example, to assisting a wearer's walking motion.

2. Description of the Related Art In recent years, walking assist devices that assist walking of elderly people and the like have attracted attention.
The walking assist device is worn on the waist or lower limb of the wearer, detects the movement of the wearer's body with a sensor or the like, and assists the wearer's walking movement with a motor.
In the walking assist device, there is a demand for using electric power as efficiently as possible in order to reduce the weight of the battery as much as possible.

  The assist device for walking of Patent Document 1 decreases the assist ratio as the remaining battery level decreases when the remaining battery level becomes equal to or less than a threshold value. Thereby, a battery can be made lasting without making a wearer feel uncomfortable, and electric power can be used efficiently.

  However, this technique has a problem that the assist force is reduced even in a scene where assistance is required, for example, because the assist ratio is uniformly reduced.

JP 2010-75658 A

  An object of the present invention is to perform more appropriate energy saving control in walking assist.

(1) In the invention described in claim 1, the power storage means, the holding means for holding the leg part of the walking support target, the driving means for driving the holding means by the power supplied by the power storage means, and the driving Control means for assisting the force required for the movement of the leg by controlling the force exerted by the means, and the control means is applied to the free leg of the both legs in a predetermined case. Provided is a walking assist device characterized in that the force exerted by the driving means is reduced from a normal force.
(2) In the invention according to claim 2, the control means further reduces the force exerted by the drive means on the standing leg portion of the both leg portions from a normal force in a predetermined case. A walking support device according to claim 1 is provided.
(3) In the invention described in claim 3, the walking support device according to claim 1 or 2, wherein the predetermined case is a case where the walking surface is a downhill.
(4) In the invention according to claim 4, the walking support device according to claim 3 is provided, wherein the predetermined case is a case where the walking surface is flat.
(5) In the invention described in claim 5, the route acquisition means for acquiring the route from the current location to the destination, the supply power amount acquisition means for acquiring the supply power amount that can be supplied by the power storage means, and the drive means are demonstrated. Power consumption acquisition means for acquiring the power consumption required to walk the acquired route without reducing the power to perform, and in the predetermined case, the acquired power consumption is more The walking support device according to any one of claims 1 to 4, wherein the walking assistance device is provided in a case where it is larger than the acquired power supply amount.
(6) In the invention described in claim 6, the force that the driving means exerts is reduced so that the power consumption amount is equal to or less than the supply power amount for the downhill and flat land sections of the acquired route. The walking support apparatus according to claim 5, further comprising: a planning unit configured to plan the movement, wherein the control unit controls a force exerted on the driving unit according to the plan.
(7) In the invention according to claim 7, when the power consumption does not become equal to or less than the supply power amount according to the plan, the control means can walk the route by the supply power amount supplied by the power storage means. Thus, the walking support device according to any one of claims 1 to 6 is provided, wherein the force exerted by the driving means is reduced at a predetermined rate.
(8) In the invention described in claim 8, there is provided a walking support program used in a computer included in a walking support device including power storage means and a holding means for holding a leg portion of a walking support target person, wherein the power storage means The computer realizes a drive function for driving the holding means by the electric power supplied by the computer and a control function for assisting the force required to move the leg by controlling the force exerted by the drive function, and the control function Provides a walking support program characterized in that, in a predetermined case, the force exerted by the drive function on the free leg portion of the both leg portions is reduced from the normal force.

  According to the present invention, more appropriate energy saving control can be performed by reducing the assist force according to the walking state.

It is explanatory drawing about the mounting state of a mounting type robot, and a mounting robot system. It is explanatory drawing about the aspect of the walk assistance which the walk assistance apparatus 1 performs. It is a flowchart about the walk assistance operation | movement which the walk assistance apparatus 1 performs. It is a flowchart explaining the process sequence in case SOC is below a total energy amount. It is another flowchart explaining a process in case SOC is below a total energy amount. It is another flowchart explaining a process in case SOC is below a total energy amount. It is a flowchart explaining the procedure of minimum assist control.

(1) Outline of Embodiment (a) The walking assist device 1 acquires all walking routes to a destination, and obtains electric power required when normal assistance is performed based on the walking distance. And when the remaining amount of the battery 18 is insufficient for walking assist until it reaches the destination, the assist power of the free leg away from the ground is reduced to reduce battery consumption and continue the assist to the destination. . The load on the wearer M is small when going down a slope, and it is considered that the load on the wearer M is smaller when the free leg assist force is reduced between the free leg and the standing leg. Therefore, the assist method is selected and executed by reducing the assist force in the order of descending free leg, flat free leg, descending leg, and flat leg in order.

(B) Specifically, the walking assist device 1 (FIG. 1) drives the walking actuator 17 installed at each joint of both legs of the wearer M to assist the wearer M in walking.
The walking assist device 1 obtains all walking routes to the destination by calculation of the device itself or communication from the outside, and obtains electric power necessary for normal assistance based on the walking distance. When the entire walking route is calculated by the own device, the travel route to the destination acquired or input from the schedule is searched using the map data.
When the remaining amount of the battery 18 is insufficient for the walking assist until the destination reaches the destination, the walking assist device 1 is a free leg (a leg on the side away from the ground, but a leg with a zero floor reaction force). May be reduced) to reduce battery consumption and continue assistance to the destination.
In this embodiment, as an example, the assist force is reduced to zero, but the assist force is reduced to a predetermined ratio with respect to the normal assist force with respect to the saving assist at each stage described later, and the reduction amount is still not sufficient. In addition, the assist force may be reduced to zero.

Even if the assist force is zero, the burden on the wearer M is considered to be the lowest when going down hills or stairs. Also, the free leg and the standing leg (at least part of the body (weight) on the ground) It is considered that the burden on the wearer M is smaller when the assist force of the free leg is reduced.
Therefore, when the walk assist device 1 cannot perform walk assist until the destination is reached with the remaining amount of the battery 18 when performing normal assist, the walk assist device 1 first goes down a hill or stairs as a first-stage saving assist. The battery 18 is saved by reducing the assist force of the free leg in the following (hereinafter simply referred to as “down”).
In the first stage of saving assistance, normal assistance is provided for standing legs in all cases, and when climbing hills and stairs (hereinafter simply referred to as “up”) and free legs on flat ground.

Even if the first stage of saving assistance is performed up to the destination, if it is determined that battery saving is still insufficient (battery is insufficient), the walking assist device 1 will walk to the destination (the entire process). On the other hand, the second stage of saving assistance is performed.
If it is determined that there is still a shortage, the third-stage saving assist is performed, and if it is still determined that it is still insufficient, the fourth-stage saving assist is performed, and further the fifth-stage saving assist is performed.

In the second stage of saving assist, the walking assist device 1 performs normal assist on the standing legs and the free legs on the uphill in all cases, and reduces the assist force on the free legs on the down and flat ground.
The walking assist device 1 performs normal assist for the standing leg on the flat ground and the uphill and the free leg on the uphill in the third stage of saving assistance. Further, the assist force is reduced with respect to the standing leg and the free leg on the downhill and the free leg on the flat ground.
The walking assist device 1 performs normal assist for the standing leg and the free leg in the uphill and reduces the assist force for the standing leg and the free leg in the downhill and the flat ground in the fourth stage of saving assist.
In the fifth stage of saving assist, the normal assist amount is uniformly reduced to a level where the current battery amount can reach the destination.

  Thus, since it is the uphill that the wearer M needs the most assist force, in this embodiment, when walking uphill, the assist force is not reduced for both the free leg and the standing leg. I have to.

(2) Details of Embodiment FIG. 1A is a diagram showing a wearing state of the walking assist device 1.
The walking assist device 1 is a walking assistance device that is worn on the waist and lower limbs of the wearer M and supports (assists) the walking of the wearer M. In addition, for example, it may be attached to the upper body and the lower body to assist the movement of the whole body.

The walking assist device 1 includes a waist mounting portion 7, a walking assist portion 2, a connecting portion 8, a three-axis sensor 3, a three-axis actuator 6, an imaging camera 5, a light source device 4, an imaging unit that holds the imaging camera 5 and the light source device 4. 9, a wireless communication device 10, a navigation device 12, a landing sensor 13, and the like.
The waist mounting portion 7 is a fixing device that fixes the walking assist device 1 to the waist of the wearer M. The waist mounting part 7 moves integrally with the waist of the wearer M.
Further, the waist mounting portion 7 includes a walking actuator 17 (FIG. 1B), and drives the connecting portion 8 in the front-rear direction and the like according to the walking motion of the wearer M.

The connecting part 8 connects the waist mounting part 7 and the walking assist part 2.
The walking assist unit 2 is attached to the lower limb of the wearer M, and is driven in the front-rear direction and the like by the walking actuator 17 to support the walking motion of the wearer M.
In FIG. 1, the walking actuator 17 is configured to drive the walking assist unit 2 by releasing the connecting unit 8, but this is for simplifying the drawing and the description. A walking actuator installed at each of the joints having a multi-joint structure corresponding to the hip joint, knee joint, and ankle joint of the person M. The rotation angle of each joint is detected by an encoder installed at each joint. It is driven by 17 power.

The triaxial sensor 3 is installed in the waist mounting portion 7 and detects the posture of the waist mounting portion 7 and the like. The triaxial sensor 3 includes, for example, a triaxial angular velocity detection function and a triaxial angular acceleration detection function using a three-dimensional gyro, and the rotation angle, angular velocity, and angular acceleration around the forward, vertical, and body-side axes. Can be detected.
The angle around the forward axis is the roll angle, the angle around the vertical axis is the yaw angle, and the angle around the body-side axis is the pitch angle.

The triaxial actuator 6 is configured by, for example, a spherical motor, and changes the roll angle, yaw angle, and pitch angle of the imaging unit 9 in which the imaging camera 5 and the light source device 4 are installed.
The light source device 4 and the imaging camera 5 are fixed to the imaging unit 9, and when the triaxial actuator 6 is driven, the irradiation direction of the light source device 4 (the direction of the optical axis of the light source device 4) and the imaging direction of the imaging camera 5. (The direction of the optical axis of the imaging camera 5) changes the roll angle, yaw angle, and pitch angle with respect to the waist mounting portion 7 while maintaining the relative angle.

  In order to capture an appropriate image with the imaging unit 9, the imaging unit 9 needs to be directed to the walking reference plane (walking plane) at a predetermined angle, but when the wearer M wears the walking assist device 1, Since the imaging unit 9 is inclined depending on the mounting state, the triaxial actuator 6 corrects this.

  The light source device 4 irradiates light such as laser, infrared light, and visible light in a predetermined shape pattern, for example. In the present embodiment, the light source device 4 emits light in a shape pattern that is circular with respect to a plane perpendicular to the irradiation direction, but various shapes such as a rectangular shape, a cross, and a dot are possible.

The imaging camera 5 is configured by an infrared light camera, a visible light camera, or the like that includes an optical system for forming an image of a subject and a CCD (Charge-Coupled Device) that converts the imaged subject to an electrical signal. The light source device 4 captures (shoots) a projection image irradiated on the walking reference plane.
The projection image by the light emitted by the light source device 4 in a predetermined shape pattern has a shape deformed (distorted) from a circle due to an angle formed by the irradiation direction and the walking surface, or an obstacle (such as a step) existing on the walking surface. However, by analyzing this shape, it is possible to detect the forward state (for example, the presence of a downhill, the presence of flat ground, etc.)

The wireless communication device 10 detects various types of information such as tread information included in the light emitted from the lighting 100.
When the light includes information indicating the start point and end point of the downhill, the start point and end point of the flat ground, the walking assist device 1 recognizes the start point and end point of the downhill, and the start point and end point of the flat ground thereby. Can do.

The navigation device 12 receives a GPS signal from a GPS (Global Positioning System) satellite, communicates with a predetermined server to identify the current position of the wearer M, and provides a route from the current position to the destination. It has navigation functions such as searching.
The searched route includes information on the state of the walking surface such as a downhill section and a flat section.

The landing sensor 13 is installed on the soles of both legs and detects that the soles are grounded. The landing sensor 13 functions as a free leg part detecting unit that detects a leg part away from the walking surface of both leg parts as a free leg part. Further, the landing sensor 13 also functions as a leg detection unit that detects a leg that is in contact with the walking surface of both legs as a leg.
The walking assist device 1 detects the ground contact of the left leg and the right leg individually by the landing sensor 13 so that any leg is a free leg (the leg that is moved to take the next step). It is determined whether the leg is a standing leg (mainly a leg that supports weight).
In this embodiment, the leg that detects the state where the sole is not in contact with the ground by the landing sensor 13 is a free leg, but the pressure sensor that detects the reaction force from the floor is grounded on the sole. Alternatively, a leg with zero floor reaction force may be a free leg, and a leg with no floor reaction force may be a standing leg.

FIG. 1B is a diagram for explaining the mounting robot system 15 installed in the walking assist device 1.
The wearing robot system 15 is an electronic control system that controls the walking assist device 1 so as to exhibit a walking support function.

  An ECU (Electronic Control Unit) 16 is an electronic control unit including a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a storage device, various interfaces, and the like (not shown), and a walking assist device. Each part of 1 is electronically controlled.

The CPU executes various computer programs stored in the storage medium, and sets an assist plan such as a section for reducing the assist force in the walking route from the remaining battery level and for which leg the assist force is reduced. Based on the plan, the walking actuator 17 is driven to assist walking.
The CPU is connected to the light source device 4, the imaging camera 5, the three-axis actuator 6, the three-axis sensor 3, the wireless communication device 10, the navigation device 12, and the landing sensor 13 through an interface, and irradiation from the light source device 4. ON / OFF, acquisition of imaging data from the imaging camera 5, driving of the triaxial actuator 6, acquisition of detection values from the triaxial sensor 3, and starting and ending points of downhill and flat ground from the wireless communication device 10 Or the current position of the wearer M is acquired from the navigation device 12.

The ROM is a read-only memory and stores basic programs and parameters used by the CPU.
The RAM is a readable / writable memory, and provides a working memory when the CPU performs arithmetic processing and the like.

  The storage device includes a large-capacity storage medium composed of, for example, a hard disk or an EEPROM (Electrically Erasable Programmable ROM), and various programs such as a program for assisting walking, and walking information of the walking assist device 1 An archive or the like for detecting and storing the data by sampling is stored.

The walking actuator 17 drives the walking assist unit 2 based on a command from the ECU 16.
The ECU 16 controls the walking actuator 17 provided in each of the hip joint, the knee joint, and the ankle joint to cause the walking assist device 1 to perform a walking support operation as a unit.
The battery 18 is a power storage device configured with, for example, a lithium ion battery. The walking actuator 17 can be driven by the electric power supplied from the battery 18 or the ECU 16 can be operated.
The SOC detection device 19 detects a remaining battery level (SOC: State of Charge), that is, a suppliable electric energy.

Each figure of FIG. 2 is a figure for demonstrating the aspect of the walk assistance which the walk assist apparatus 1 performs.
FIG. 2A is a diagram for explaining an assist location by the walking assist device 1.
The walking assist device 1 is a walking in which the rotational motions of the hip joint 30R, knee joint 40R, ankle joint 50R of the right leg 20R and the hip joint 30L, knee joint 40L, ankle joint 50L of the left leg 20L are arranged at these joints. This is supported by the actuator 17.

FIG. 2B is a diagram for explaining the minimum assist on the downhill.
The walking assist device 1 sets the power of the hip joint, knee joint, and ankle joint of the free leg to zero when performing the minimum assist on the downhill.
This is because it is considered that the necessity for assisting is lower on the downhill than on the uphill, and that the need for assisting the free leg is lower than that on the standing leg. Setting the power to zero is merely an example, and may be a value reduced by a predetermined amount.

In the example of FIG. 2B, the right leg portion 20R is a free leg and the left leg portion 20L is a standing leg. In the minimum assist, the walking assist device 1 sets the assist force to zero (that is, turns off the assist function) for the hip joint 30R, the knee joint 40R, and the ankle joint 50R of the right leg 20R on the free leg side. Normal assistance is performed for the hip joint 30L, the knee joint 40L, and the ankle joint 50L of the left leg 20L on the stance side.
Since the free leg and the standing leg are changed every step, the legs having zero assist force are also alternated.

FIG. 2C is a diagram for explaining the minimum assist on a flat ground.
The walking assist device 1 sets the power of the hip joint, knee joint, and ankle joint of the free leg to zero when performing minimal assist on a flat ground.
In the example of FIG. 2 (c), the right leg 20R is a free leg and the left leg 20L is a standing leg. In the minimum assist, the walking assist device 1 sets the assist force to zero for the hip joint 30R, the knee joint 40R, and the ankle joint 50R of the right leg 20R, and the hip joint 30L, the knee joint 40L, and the ankle joint 50L of the left leg 20L. For normal assistance.

FIG. 3A is a flowchart for explaining the walking support operation performed by the walking assist device 1. The following processing is performed from the CPU of the ECU 16 according to the walking support program.
First, the ECU 16 acquires the SOC using the SOC detection device 19 (step 5).

Next, the ECU 16 acquires (calculates) a route from the current position to the destination from the navigation device 12 (step 10).
The navigation device 12 detects a current position by GPS or the like, acquires a destination input by the wearer M, and acquires a route by searching for a route from the current position to the destination.

Next, the ECU 16 acquires the total energy amount in the route (step 15). This calculation may be acquired from a past archive or may be calculated from a route.
Next, the ECU 16 compares the total energy amount with the SOC (step 20).
When the SOC is larger than the total energy amount (step 20; Y), the battery 18 can supply electric power necessary until the wearer M arrives at the destination, so the ECU 16 performs assist control by a normal method ( Step 25).
On the other hand, when the SOC is equal to or less than the total energy amount (step 20; N), the process proceeds to the process shown in the flowchart of FIG.

FIG. 3B is a flowchart for explaining the processing procedure when the SOC is equal to or less than the total energy amount (step 20; N).
In this case, the ECU 16 acquires the downhill ratio from the route (step 30). For example, when the length of the route is 1 km and the downhill is 200 m, the downhill ratio is 20%.

Next, the ECU 16 adds the energy saving operation amount α% to the downhill ratio (step 35).
Here, the energy saving operation amount α% is a ratio of energy required when assisting at a minimum on a downhill to energy required when assisting with a normal method on a downhill (in the case of full assist).
Then, the energy required to assist at a minimum on the downhill can be calculated by the following equation (1).
(Energy required to assist at minimum on a downhill) = (Length of downhill) × (Energy required when assisting in a normal manner on a downhill) × α (1)

Next, the ECU 16 recalculates the total amount of energy required when assisting downhill at a minimum and assisting other than downhill by a normal method (step 40).
This is to calculate the energy required to assist the downhill at a minimum by the equation (1), calculate the energy required to assist the route other than the downhill by a normal method, or obtain from the archive, It can be obtained by adding these.

Next, the ECU 16 compares the recalculated total energy amount with the SOC (step 45).
When the SOC is larger than the recalculated total energy amount (step 45; Y), the ECU 16 performs a first-stage saving assist. That is, the battery 18 can supply power required until the wearer M arrives at the destination if the assist is made only for walking on the downhill, so the ECU 16 provides the minimum assist on the downhill. In other sections, assist in the usual way. The specific internal use of the minimum assist will be described later (FIG. 7).

First, in the first-stage saving assist, the ECU 16 determines whether or not the vehicle is walking on a downhill (step 50).
This is determined using the current position by the navigation device 12, information received by the wireless communication device 10, a projection image taken by the imaging camera 5, and the like.
When walking downhill (step 50; Y), the ECU 16 performs minimum assist control on the downhill (step 55).
When not walking on the downhill (step 50; N), the ECU 16 performs assist control by a normal method (step 60).

Thereafter, the ECU 16 determines in step 50 whether or not the user is walking on the downhill until reaching the destination. If the ECU 16 is walking on the downhill, the ECU 16 assists with the minimum assist.
On the other hand, when the SOC is equal to or less than the total energy amount (step 45; N), the process proceeds to the process shown in the flowchart of FIG.

FIG. 4 is a flowchart for explaining the processing procedure when the SOC is equal to or less than the total energy amount (step 45; N).
First, the ECU 16 acquires the ratio of flat land from the route (step 65).
Next, the ECU 16 adds the energy saving operation amount β% to the ratio of the flat land (step 70).
Here, the energy saving operating amount β% is a ratio of energy required when assisting at a minimum on flat ground to energy required when assisting by a normal method on flat ground.
Then, the energy required for minimal assist on a flat ground can be calculated by the following equation (2).
(Energy required to assist at least on flat ground) = (Length of downhill) × (Energy required when assisting by a normal method) × β (2)

Next, the ECU 16 performs a minimum assist on the downhill and the flat ground, and recalculates the total amount of energy required when assisting by a normal method other than on the downhill and the flat ground (step 75).
This is to calculate the energy required to assist at least on downhills and flat grounds using equations (1) and (2), and to calculate the energy required to assist routes other than downhills and flat grounds in the usual manner. It can be obtained by calculating or obtaining from an archive and adding them.

Next, the ECU 16 compares the recalculated total energy amount with the SOC (step 80).
When the SOC is larger than the recalculated total energy amount (step 80; Y), the ECU 16 performs a second-stage saving assist.
In other words, the battery 18 can supply the power required until the wearer M arrives at the destination if the assist is performed on the downhill and the flat ground. Therefore, the ECU 16 performs the minimum assist on the downhill and the flat ground. In other sections, assist is performed by a normal method.

First, the ECU 16 determines whether or not it is walking downhill (step 85).
When the vehicle is walking on the downhill (step 85; Y), the ECU 16 performs the minimum assist control on the downhill (step 90).
When not walking on the downhill (step 85; N), the ECU 16 determines whether or not the vehicle is walking on the flat ground (step 95).
This is determined using the current position by the navigation device 12, information received by the wireless communication device 10, a projection image taken by the imaging camera 5, and the like.

When the vehicle is walking on the flat ground (step 95; Y), the ECU 16 performs the minimum assist control on the flat ground (step 100).
When the vehicle is not walking on the flat ground (step 95; N), the ECU 16 performs assist control by a normal method (step 105).

Thereafter, the ECU 16 determines whether or not it is walking on the downhill in step 85 until it reaches the destination, and determines whether or not it is walking on the flat ground in step 95 and is walking on the downhill. Or, if you are walking on flat ground, assist with minimal assistance.
On the other hand, when the SOC is equal to or less than the total energy amount (step 80; N), the process proceeds to the process shown in the flowchart of FIG.

FIG. 5 is a flowchart for explaining the processing when the SOC is equal to or less than the total energy amount (step 80; N).
In this case, the ECU 16 assists the sections other than the downhill and the flat ground by a normal method, and recalculates the total energy amount required for assisting the flat ground at a minimum (step 110).

Next, the ECU 16 compares the recalculated total energy amount with the SOC (step 115).
When the SOC is larger than the recalculated total energy amount (step 115; Y), the ECU 16 performs a third-stage saving assist.
That is, the battery 18 can supply power necessary until the wearer M arrives at the destination if the assist is not performed on the downhill but the minimum assist on the flat ground. Therefore, the ECU 16 performs the assist on the downhill. First of all, the assist is performed on the flat ground at the minimum, and the assist is performed in the normal manner in the other sections.

First, the ECU 16 determines whether or not it is walking downhill (step 120).
When the vehicle is walking on the downhill (step 120; Y), the ECU 16 sets the assist on the downhill to zero (step 125).
When not walking on the downhill (step 120; N), the ECU 16 determines whether or not walking on the flat ground (step 130).

When walking on a flat ground (step 130; Y), the ECU 16 performs a minimum assist on a flat ground (step 135).
When the vehicle is not walking on the flat ground (step 130; N), the ECU 16 performs assist control by a normal method (step 140).

Thereafter, the ECU 16 determines whether or not the vehicle is walking on the downhill in step 120 until it reaches the destination, determines whether or not it is walking on the flat ground in step 130, and is walking on the downhill. In the case of (1), the assist is set to zero, and the minimum assist is performed when walking on a flat ground.
On the other hand, when the SOC is equal to or less than the total energy amount (step 115; N), the process proceeds to the process shown in the flowchart of FIG.

FIG. 6A is a flowchart for explaining the processing when the SOC is equal to or less than the total energy amount (step 115; N).
In this case, the ECU 16 recalculates the total amount of energy required when assisting the sections other than the downhill and the flat land by a normal method (step 145).

Next, the ECU 16 compares the recalculated total energy amount with the SOC (step 150).
When the SOC is larger than the recalculated total energy amount (step 150; Y), the ECU 16 performs a fourth-stage saving assist.
In other words, the battery 18 can supply power required until the wearer M arrives at the destination unless assistance is performed on the downhill and the flat ground. Therefore, the ECU 16 does not assist on the downhill and the flat ground. In other sections, assist is performed by a normal method.

First, the ECU 16 determines whether or not it is walking downhill (step 155).
When the vehicle is walking on the downhill (step 155; Y), the ECU 16 sets the assist on the downhill to zero (step 160).
When not walking on the downhill (step 155; N), the ECU 16 determines whether or not walking on the flat ground (step 165).

When the vehicle is walking on the flat ground (step 165; Y), the ECU 16 sets the assist on the flat ground to zero (step 170).
When the vehicle is not walking on the flat ground (step 165; N), the ECU 16 performs assist control by a normal method (step 175).

  Thereafter, the ECU 16 determines whether or not the vehicle is walking on the downhill in step 155 until it reaches the destination, determines whether or not it is walking on the flat ground in step 165, and is walking on the downhill. Or, if you are walking on flat ground, set the assist to zero.

On the other hand, when the SOC is equal to or less than the recalculated total energy amount (step 150; N), the fifth stage of saving assistance is performed according to the flowchart of FIG. 6B.
FIG. 6B is a flowchart for explaining the fifth-stage saving assist process when the SOC is equal to or less than the total energy amount (step 150; N).
In this case, the ECU 16 calculates the energy reduction ratio by dividing the SOC by the energy required when assisting the SOC to the destination by a normal method (step 180).
Next, the ECU 16 calculates the assist amount by multiplying the assist amount by the normal method by the energy reduction ratio (step 185).

Then, the ECU 16 performs assist control with the newly calculated assist amount (step 190).
Thus, the ECU 16 uniformly reduces the normal assist amount to a level at which the battery 18 can reach the destination with the SOC.

FIG. 7 is a flowchart for explaining the procedure of the minimum assist control.
First, the ECU 16 determines from the detection value of the landing sensor 13 whether or not both the right leg and the left leg of the wearer M are landing (step 505).
If both legs have landed (step 505; Y), the ECU 16 turns on the power of all walking actuators 17 (step 510). That is, the ECU 16 assists both feet.

When there is a leg that has not landed among the two legs (step 505; N), the ECU 16 determines whether only the right leg is landed from the detection value of the landing sensor 13 (step 515).
When only the right leg has landed (step 515; Y), the ECU 16 determines that the left leg is a free leg and turns off the power of all the walking actuators 17 of the left leg (step 520). That is, the ECU 16 sets the assist for the left leg to zero.
On the other hand, when only the left leg has landed (step 515; N), the ECU 16 determines that the right leg is a free leg and turns off the power of all walking actuators 17 of the right leg (step 525). . That is, the right leg assist is set to zero.

  In the embodiment described above, the minimum assist and the assist force of both legs are reduced from the viewpoint of holding the battery to the destination. For example, the mode selection button is provided to allow the wearer M to select. You can also.

According to the embodiment described above, the following effects can be obtained.
(1) The continuous use time / distance is calculated from the route information, and when the battery 18 does not have enough electric power, the energy-saving assist control is positively performed. Specifically, the power is actively reduced in a place where a large assist force such as a downhill obtained from the route information is unnecessary.
(2) Since the conventional walking assist device does not know the route to walk, etc., the necessary continuous use time (or distance) is not known, and there is a possibility that power may be lost along the route. Since the apparatus 1 makes an assist plan so as to have the battery to the destination, the battery can be provided to the destination.
(3) Since the battery has up to the destination, the battery runs out before reaching the destination and does not drag its own weight.
(4) For example, energy saving control can be performed without making the wearer M feel uncomfortable while holding the battery to the destination, for example, by reducing the assist force from the free leg on the downhill.
(5) When the electric power of the battery 18 mounted on the walking assist device 1 is lower than the electric power required for walking assist, the assist control is performed only for ascending, and the assist control is performed for descending or walking on a flat ground. Narrow down or not.

In the embodiment described above, the following functional configuration can be adopted.
The battery 18 functions as power storage means.
The walking assist unit 2 functions as a holding unit that holds the legs of the walking support target person.
The walking actuator 17 functions as a driving unit that drives the holding unit with electric power supplied from the power storage unit.
The ECU 16 functions as a control unit that assists the force required to move the leg by controlling the force exerted by the driving unit.
Then, the ECU 16 reduces the assist force for the free leg portion to zero, for example, so that the force exerted by the drive means on the free leg portion that moves for the next step in a predetermined case is determined. A walking support device characterized by being reduced from a normal force.

  Further, the ECU 16 reduces the assist force to the stance portion, and in a predetermined case, the ECU 16 further applies the force exerted by the driving means to the stance portion that mainly supports the current weight. Less than.

DESCRIPTION OF SYMBOLS 1 Wearable robot 2 Walk assist part 3 3-axis sensor 4 Light source device 5 Imaging camera 6 3-axis actuator 7 Lumbar mounting part 8 Connection part 9 Imaging unit 10 Wireless communication apparatus 12 Navigation apparatus 13 Landing sensor 15 Wearing robot system 16 ECU
17 Walking Actuator 18 Battery 19 SOC Detection Device 20L Left Leg 20R Right Leg 30L, 30R Hip Joint 40L, 40R Knee Joint 50L, 50R Ankle Joint 100 Illumination

Claims (8)

Power storage means;
Holding means for holding the legs of the walking support target person;
Driving means for driving the holding means by the power supplied by the power storage means;
Control means for assisting the force required to move the leg by controlling the force exerted by the driving means,
The walking support device according to claim 1, wherein the control means reduces the force exerted by the driving means on the free leg portion of the both leg portions in a predetermined case from a normal force.   2. The walking according to claim 1, wherein the control unit further reduces, in a predetermined case, a force exerted by the driving unit on a standing leg part of the both leg parts from a normal force. Support device.   The walking support apparatus according to claim 1, wherein the predetermined case is a case where the walking surface is a downhill.   The walking support device according to claim 3, wherein the predetermined case is a case where the walking surface is flat. Route acquisition means for acquiring a route from the current location to the destination;
A supply power amount acquisition means for acquiring a supply power amount that can be supplied by the power storage means;
Power consumption acquisition means for acquiring power consumption required to walk the acquired route without reducing the force exerted by the drive means;
Comprising
5. The method according to claim 1, wherein the predetermined case is a case where the acquired power consumption amount is larger than the acquired supply power amount. The walking support device described. For a downhill and flat section of the acquired route, comprising a planning means for planning a reduction in the force exerted by the driving means so that the power consumption amount is equal to or less than the supplied power amount,
The walking support apparatus according to claim 5, wherein the control unit controls a force exerted on the driving unit according to the plan. When the power consumption does not fall below the supply power amount according to the plan,
7. The control device according to claim 1, wherein the control unit reduces the force exerted by the driving unit at a predetermined rate so that the path can be walked by the amount of power supplied by the power storage unit. The walking support device according to any one of the claims.
A walking support program used in a computer included in a walking support device including a power storage unit and a holding unit that holds a leg of a walking support target person,
A drive function for driving the holding means with the power supplied by the power storage means;
A control function for assisting the force required to move the leg by controlling the force exerted by the drive function;
Is realized on a computer,
The walking support program characterized in that the control function reduces, in a predetermined case, a force exerted by the driving function on the free leg portion of the both leg portions, compared to a normal force.

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