JP2009119014A - Walking assisting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a handcart type walking assisting device suitably assisting the walking of a walker in various conditions. <P>SOLUTION: The walking assisting device comprises: a handle 21 extended horizontally to a road surface at such a height that it can be held by a walker; main frames 14L and 14R extended to the vicinity of the road surface from the handle to the oblique lower part on the front side of the walker; sub-frames extended to the vicinity of the road surface from the middle pat of the main frames to the road surface near the walker; joints 18L and 18R for freely turnably connecting the sub-frames to the main frames; a power supply unit 22 suspended from the joints; front side wheels 20FL and 20FR and rear side wheels 20RL and 20RR driven by power from the power supply unit; and a controller 12d for controlling each of the front side wheels and the rear side wheels. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a walking assistance device for assisting a pedestrian to walk, and more particularly to a handcart type walking assistance device.

An example of a handcart type walking assist device is shown in the conventional literature (Patent Literatures 1-3).
Japanese Patent No. 3156367 JP-A-10-216183 Patent No. 3480095

  The wheelbarrow type walking assist device is relatively compact and has good handling characteristics. However, there are various situations in which walking assist devices are used. For example, the walking assist device may assist the walking of a pedestrian on an inclined road surface. In addition, for example, the walking assist device may assist a pedestrian in walking on a step or a staircase. In addition, the walking assist device needs to cope with a situation where a pedestrian is about to fall.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a handcart type walking assistance device that can suitably assist a pedestrian in various situations.

  In order to achieve the above-described object, a walking assistance device according to the present invention includes a handle that is horizontally extended with respect to a road surface at a height that can be gripped by a pedestrian, and a diagonally lower front side of the pedestrian from the handle. A main frame extending near the road surface toward the road surface, a sub frame extending from the middle part of the main frame toward the road surface near the pedestrian and near the road surface, and provided in the middle part of the main frame. A movable joint, a power supply unit suspended from the joint, a lower end near the road surface of the main frame, a front wheel driven by electric power from the power supply unit, and a lower end near the road surface of the subframe Controller for controlling each of the rear wheels driven by electric power from the power supply unit, and the front wheels and the rear wheels. Characterized in that it comprises a chromatography La, a.

  According to the walking assist device of the present invention, the handle is provided at a height that can be gripped by a pedestrian, and the front wheel is provided at the lower end of the main frame that extends obliquely downward from the handle. A rear wheel is provided at the lower end of the subframe extending from the middle portion. With such a basic configuration of the walking assistance device, since the pedestrian can walk while holding the handle and leaning on the walking assistance device, the walking assistance device can assist the walking of the pedestrian. According to the walking assist device of the present invention, the subframe is rotatable with respect to the main frame by the joint provided in the middle part of the main frame, and the lower ends of the main frame and the subframe. The wheels provided in the are driven by the supply of electric power. With such a configuration of the walking assistance device, the walking assistance device can favorably assist the walking of the pedestrian in various situations.

  In the walking assistance device according to the present invention, the controller preferably adjusts the height of the steering wheel from the road surface by adjusting the relative distance between the front wheel and the rear wheel. According to this configuration, the height from the road surface of the handle can be adjusted to a height that the pedestrian can easily hold.

  In the walking assist device according to the present invention, the front wheel includes a left front wheel and a right front wheel, the rear wheel includes a left rear wheel and a right rear wheel, and the controller includes a relative distance between the left front wheel and the left rear wheel, It is preferable to adjust the inclination of the walking assistance device in the left-right direction by independently controlling the relative distance between the wheel and the right rear wheel. According to this configuration, the walking assistance device can be stabilized, for example, even on an unstable road surface inclined to the left and right by adjusting the inclination of the walking assistance device in the left-right direction.

  The walking assist device according to the present invention further includes a pressing force sensor that detects a pressing force applied to the handle by the pedestrian, and the controller controls the pedestrian to handle the pressing force detected by the pressing force sensor. It is preferable to control the front wheel and the rear wheel so that the pressing force applied to the vehicle is substantially constant. According to this configuration, since the pressing force applied to the handle by the pedestrian is made substantially constant, the posture of the pedestrian can be stabilized and the pedestrian's comfort can be improved.

  In addition, the walking assist device according to the present invention further includes a gradient sensor that detects a gradient of the road surface, and the controller determines that the pressing force applied to the handle by the pedestrian is substantially constant based on the gradient detected by the gradient sensor. It is preferable to control the front wheel and the rear wheel by changing the pressing force threshold range for the operation. According to this configuration, when the road surface is a downhill, the pedestrian can safely walk on the downhill while leaning on the walking assist device with a large force in order to increase the pressing force applied to the handle by the pedestrian. it can.

  Moreover, it is preferable that the walk assistance apparatus which concerns on this invention is further provided with the support belt | band | zone which both ends are fixed to a joint, and is hung on a pedestrian's waist. According to this configuration, it is possible to reduce the burden on the pedestrian when climbing uphill.

  In the walking assistance device according to the present invention, the controller is preferably provided on the handle. According to this configuration, since the controller is provided on the handle, the pedestrian can easily operate the walking assist device.

  In addition, the walking assist device according to the present invention includes a first angle sensor that detects an angle α formed by the subframe with respect to the main frame, and a second angle sensor that detects an angle γ formed by the power supply unit with respect to the main frame. It is preferable that the controller recognizes the posture of the walking assistance device based on the angles α and β detected by the first angle sensor and the second angle sensor. According to this configuration, the posture of the walking assistance device can be recognized and used for controlling the walking assistance device.

  In the walking assistance device according to the present invention, it is preferable that the controller determines whether or not the walking assistance device can get over a step or stairs based on the recognition result of the posture of the walking assistance device. According to this configuration, since it is determined whether or not the walking assistance device can get over the step or the stairs, it can be determined whether or not the walking assistance device can pass through the step or the stairs.

  In the walking assistance device according to the present invention, the controller preferably calculates the shape of the step or the staircase based on the recognition result of the posture of the walking assistance device. According to this configuration, since the walking assistance device calculates the shape of the step or the stairs, it can be determined whether or not the walking assistance device can pass through the step or the stairs.

  In the walking assistance device according to the present invention, it is preferable that the controller determines that the front wheel or the rear wheel has contacted the step or the stairs based on the torque acting on the joint. According to this configuration, since it is determined that the step or the stairs has been touched based on the torque acting on the joint, the step or the stairs can be detected with high accuracy.

  In the walking assist device according to the present invention, the main frame is separated into an upper part from the handle to the joint and a lower part below the joint, and the upper part is independent from the lower part. The controller is configured to be pivotable around the joint, and when the controller determines that the pedestrian falls to the rear, the main frame and the power unit are integrated, the power unit is moved forward, It is preferable to rotate the upper part of the frame backward. According to this configuration, when the pedestrian is about to fall backward, the pedestrian can be prevented from falling by using the inertial force of the power supply unit.

  In the walking assistance device according to the present invention, the controller preferably rotates the subframe to the rear side when it is determined that the pedestrian falls backward. According to this configuration, when the pedestrian is about to fall backward, the sub-frame is rotated rearward to stabilize the walking assist device, so that the pedestrian can be more reliably prevented from falling. it can.

  The walking assistance device according to the present invention further includes a pressing force sensor that detects a force that the pedestrian gives to the handle, and the controller moves the pedestrian backward based on the force detected by the pressing force sensor. It is preferable to determine the fall. According to this structure, based on the force which a pedestrian gives to a handle | steering-wheel, a pedestrian's fall to back can be determined reliably.

  ADVANTAGE OF THE INVENTION According to this invention, the handcart type walking assistance apparatus which can assist a pedestrian's walk suitably in various situations can be provided.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description, the same reference numerals are used for the same elements or elements having the same function, and redundant description is omitted.

(First embodiment)
1 and 2 show the appearance of the walking assistance device 10 according to the first embodiment. FIG. 3 shows a block diagram of the walking assist device 10 according to the first embodiment. With reference to FIG. 1, FIG. 2, and FIG. 3, the structure of the walking assistance apparatus 10 which concerns on 1st Embodiment is demonstrated.

  The walking assist device 10 is of a handcart type and includes a handle 12, main frames 14L and 14R, sub frames 16L and 16R, joints 18L and 18R, a power supply unit 22, and wheels 20FL, 20FR, 20RL, and 20RR. As shown in FIG. 2, the walking assistance device 10 is configured such that the walking assistance device 10 has the handle 12 disposed at the upper end of the walking assistance device 10 by placing the walking assistance device 10 in front and the walking assistance device 10. It is configured to support the pedestrian and assist the pedestrian in walking.

  The handle 12 of the walking assist device 10 extends horizontally in the left-right direction with respect to the road surface at a grippable height before the pedestrian's chest. The handle 12 is provided with a plurality of switches 12a, 12b, 12c (step mode switch 12a, use start / end switch 12b, etc.) for a pedestrian to control the walking assist device 10. Further, inside the handle 12, a controller 12d for taking in signals from the switches 12a, 12b, and 12c and controlling the operation of the walking assist device 10 is provided. In addition, a push force sensor 26 for detecting a force by which a pedestrian pushes the handle 12 is provided inside the handle 12.

  The pair of main frames 14L and 14R extend from both ends of the handle 12 obliquely downward on the front side of the pedestrian. The pair of main frames 14 </ b> L and 14 </ b> R includes a left main frame 14 </ b> L extending from the left end of the handle 12 and a right main frame 14 </ b> R extending from the right end of the handle 12. The main frames 14L and 14R extend to the vicinity of the road surface, and front wheels 20FL and 20FR are rotatably attached to the tips of the main frames 14L and 14R.

  The pair of subframes 16L and 16R includes a left subframe 16L extending from the left main frame 14L and a right subframe 16R extending from the right main frame 14R. The pair of sub-frames 16L and 16R extends obliquely downward from the middle part of the main frames 14L and 14R. More specifically, the pair of sub-frames 16L and 16R extends from joints 18L and 18R provided in the middle of the main frames 14L and 14R toward the road surface near the pedestrian. Each sub-frame 16L, 16R extends to the vicinity of the road surface, and rear wheels 20RL, 20RR are attached to the tips of the sub-frames 16L, 16R.

  Each of the wheels 20FL, 20FR, 20RL, 20RR attached to the main frames 14L, 14R and the subframes 16L, 16R incorporates a motor for applying driving force or braking force to the wheels 20FL, 20FR, 20RL, 20RR. It is an in-wheel motor unit. The in-wheel motor units 20FL, 20FR, 20RL, and 20RR can be independently controlled by the controller 12d. That is, each of the in-wheel motor units 20FL, 20FR, 20RL, and 20RR is supplied with electric power from the power supply unit 22 and outputs a driving force or a braking force in accordance with a control command from the controller 12d.

  Joints 18L and 18R provided in the middle of the main frames 14L and 14R rotatably connect the sub frames 16L and 16R to the main frames 14L and 14R. Joint actuators 19L and 19R for adjusting the rotation angles of the sub-frames 16L and 16R are built in the joints 18L and 18R. The joint actuators 19L and 19R can be independently controlled by the controller 12d. That is, each of the joint actuators 19L and 19R receives the supply of electric power from the power supply unit 22 and rotates the sub frames 16L and 16R in accordance with a control command from the controller 12d. Each of the joint actuators 19L and 19R has frame angle sensors 30L and 30R for detecting the rotation angle α of the sub frames 16L and 16R with respect to the main frames 14L and 14R.

  The joints 18L and 18R pivotally support the sub frames 16L and 16R using bearings fixed to the main frames 14L and 14R, and the sub frames 16L and 16R can be rotated with respect to the main frames 14L and 14R. . However, since the joints 18L and 18R only need to be able to turn the subframes 16L and 16R at a part of the main frames 14L and 14R, for example, rubber is provided between the main frames 14L and 14R and the subframes 16L and 16R. It is good also as a simplified structure which interposed the bush made from. Thereby, the walking assistance apparatus 10 can be comprised lightweight and cheaply.

  The power supply unit 22 is suspended from the joints 18L and 18R. One flexible hanging band 24L is hung on the left joints 18L, 18R. One end of the hanging band 24L is fixed to the left front end of the power supply unit 22, and the other end of the hanging band is the power supply unit 22. It is fixed at the left rear end. Also, a flexible single suspension band 24R is hung on the right joints 18L and 18R, one end of the suspension band 24R is fixed to the right front end of the power supply unit 22, and the other end of the suspension band 24R is It is fixed to the right rear end of the power supply unit 22. Since the power supply unit 22 is suspended from the joints 18L and 18R, the center of gravity of the power supply unit 22 is always directly below the joints 18L and 18R.

  Since the suspension bands 24L and 24R are suspended from the joints 18L and 18R so as to be rotatable, the power supply unit 22 rotates relative to the joints 18L and 18R when the walking assist device 10 is tilted. Inside the main frames 14L and 14R, a hanging angle sensor 32 for detecting the rotation angle γ of the power supply unit 22 and the hanging bands 24L and 24R is provided. This sensor is a gradient sensor for detecting the gradient of the road surface.

  According to the walking assist device 10 described above, as shown in FIG. 4, the handle 12 is adjusted to a height that is easy for a pedestrian to grip by rotating the sub frames 16L and 16R with respect to the main frames 14L and 14R. can do. That is, not only when the walking assistance device 10 moves on a plane, but also when the walking assistance device 10 moves uphill or downhill, the controller 12d controls the joint actuators 19L, 19R and the in-wheel motors 20FL, 20FR, 20RL and 20RR are controlled, and the handle 12 is adjusted to a height at which the pedestrian can easily grasp so as to correct the posture change of the walking assist device 10.

  Further, when the pedestrian stands up from a chair or the like, the subframes 16L and 16R can be rotated with respect to the main frames 14L and 14R, thereby assisting the pedestrian in standing up. That is, the controller 12d controls the joint actuators 19L and 19R and the in-wheel motors 20FL, 20FR, 20RL, and 20RR, and increases the height of the handle 12 in accordance with the pedestrian's standing up motion. Thereby, since the handle 12 acts to lift the pedestrian, the standing motion of the pedestrian can be assisted.

  Further, when the pedestrian ends the use of the walking assist device 10, the controller 12d makes contact with the front wheels 20FL and 20FR and the rear wheels 20RL and 20RR in response to the end switch 12b being pressed by the pedestrian. In this way, the joint actuators 19L and 19R and the in-wheel motors 20FL, 20FR, 20RL, and 20RR are controlled to automatically fold the walking assist device 10. Thereby, the pedestrian can store the walking assist device 10 in the storage space after the use of the walking assist device 10 is completed.

  Further, according to the walking assist device 10 described above, as shown in FIG. 5, the left subframes 16L and 16R and the right subframes 16L and 16R are independently rotated with respect to the main frames 14L and 14R. The walking assist device 10 is tilted in the left-right direction with the distance from the left front wheel 20FL to the left rear wheel 20RL and the distance from the right front wheel 20RL to the right rear wheel 20RR being different distances. For example, when the walking assist device 10 moves on a road surface that is inclined in the left-right direction, the controller 12d controls the joint actuators 19L, 19R and the in-wheel motors 20FL, 20FR, 20RL, 20RR to move from the front wheels on the road surface side. While increasing the distance to the wheel, shorten the distance from the front wheel to the rear wheel on the road valley side. As a result, the center of gravity of the power supply unit 22 suspended from the joints 18L and 18R is closer to the road surface mountain side, and therefore, the wheels 20FL, 20FR, 20RL, and 20RR are adjusted so that the load acts evenly. Stability can be improved.

  FIG. 6 shows a flowchart of the control method of the walking assist device 10 according to the present embodiment. The control method of FIG. 6 is intended to control the force that the walking assist device 10 gives to the pedestrian to improve the comfort of the pedestrian.

  In Step 601, the controller 12d takes in the detection value of the pressing force sensor 26. Next, in step 602, the controller 12 d sets a target speed according to the detection value of the pressing force sensor 26. Here, the target speed is set to such an extent that an appropriate reaction force is applied to the pedestrian from the walking assist device 10 so that the pedestrian can lean on the walking assist device 10 appropriately. The target speed is set to a larger value as the pressing force detected by the pressing force sensor 26 is larger, and set to a smaller value as the pressing force detected by the pressing force sensor 26 is smaller. The controller 12d controls the in-wheel motors 20FL, 20FR, 20RL, and 20RR so that the walking assistance device 10 moves at the target speed.

  Next, in step 603, when the walking assistance device 10 is moved at the target speed, the controller 12d allows the pressing force by the pedestrian to be set in a pressing force threshold range (threshold consisting of an upper limit value and a lower limit value). It is continuously determined whether or not the change has been exceeded. Here, the controller 12d returns to step 602 and resets the target speed to the increased value when the pressing force by the pedestrian exceeds the pressing force upper limit value. Thereby, since the moving speed of the walking assistance device 10 increases, the pressing force applied to the walking assistance device 10 by the pedestrian can be kept substantially constant. On the other hand, if the pressing force by the pedestrian is decreasing below the pressing force lower limit value, the controller 12d returns to step 602 and resets the target speed to a reduced value. Thereby, since the moving speed of the walking assistance apparatus 10 falls, the pushing force which a pedestrian gives to the walking assistance apparatus 10 can be kept substantially constant.

  On the other hand, if the pressing force by the pedestrian has not changed beyond the upper limit value of the pressing force, the controller 12d proceeds to step 604 and the in-wheel motors 20FL, 20FR so that the walking assist device 10 proceeds at the target speed. , 20RL, 20RR are controlled. Here, when the speed of the walking assist device 10 exceeds the target speed, the controller 12d decreases the rotational speed of the in-wheel motors 20FL, 20FR, 20RL, and 20RR to target the speed of the walking assist device 10. Match the speed. In addition, when the speed of the walking assist device 10 is less than the target speed, the controller 12d increases the rotational speed of the in-wheel motors 20FL, 20FR, 20RL, 20RR, and sets the speed of the walking assist device 10 to the target speed. Match.

  According to the control method of the walking assist device 10 described above, by setting the target speed of the walking assist device 10 according to the pressing force of the pedestrian, the pressing force that the pedestrian gives to the walking assist device 10, in other words, walking The reaction force applied to the pedestrian by the auxiliary device 10 is made substantially constant. For this reason, since the pedestrian can lean on the walking assist device 10 with a constant pressing force, the posture of the pedestrian can be stabilized and the comfort of the pedestrian can be improved.

  FIG. 7 shows a flowchart of an applied control method of the walking assist device 10 according to the present embodiment. The control method of FIG. 7 is intended to maintain safety for pedestrians when the road surface is inclined.

  In Step 701, the controller 12d takes in the detection value of the pressing force sensor 26. In step 702, the controller 12 d captures the detection value of the hanging angle sensor (gradient sensor) 32. Next, in Step 703, the controller 12 d determines whether or not the road slope has exceeded a preset slope threshold value based on the detection value of the suspension angle sensor (gradient sensor) 32. Here, if the controller 12d determines that the road surface slope exceeds the preset slope threshold value, the controller 12d proceeds to the processing of step 704 to make the pressing force applied to the steering wheel by the pedestrian substantially constant. The above pressing force threshold range is increased.

  Next, in Step 705, the controller 12d determines whether or not the walking assist device 10 is moving at the target speed. Here, the controller 12d returns to step 704 and raises both the upper limit value and the lower limit value of the pressing force threshold range when the walking assist device 10 advances at a speed faster than the target speed. By this process, the reaction force received by the pedestrian from the walking assist device 10 is increased, so that the walking speed of the pedestrian can be reduced and the walking speed of the pedestrian can be brought close to the target speed. When the walking assist device 10 is traveling at the target speed, the controller 12d proceeds to the processing of step 706 and controls the in-wheel motors 20FL, 20FR, 20RL, 20RR so that the walking assist device 10 proceeds at the target speed. .

  According to the control method of the walking assist device 10 described above, when the road surface is a downhill, the pedestrian increases the reaction force that the pedestrian receives from the walking assist device 10. You can walk downhill safely while leaning on.

  FIG. 8 presents an applied method of using the walking assist device 10 according to the present embodiment. In this walking assist device 10, one end of one support band 36 is fixed to the left joint 18L, and the other end of the support band 36 is fixed to the right joint 18R. Then, when the walking assistance device 10 is used, an intermediate portion of the support belt 36 is hung on the pedestrian's waist. Thereby, the driving force of in-wheel motor 20FL, 20FR, 20RL, 20RR can be transmitted to a pedestrian, and the burden of the pedestrian when climbing uphill can be reduced.

(Second Embodiment)
Next, with reference to FIGS. 9-18, the walking assistance apparatus 10 which concerns on 2nd Embodiment is demonstrated.

  The walking assist device 10 according to the second embodiment uses a posture recognition function that recognizes the posture of the walking assist device 10 and a step shape that calculates the shape of the step (stair) using the recognized posture of the walking assist device 10. It has a calculation function and a determination function for determining whether or not the step can be raised based on the calculated step shape. Below, each said function of the walking assistance apparatus 10 is demonstrated.

First, with reference to FIG. 9, the dimension of each part of the walking assistance apparatus 10 is demonstrated.
Lh: Length from main frame handle to joint Lf: Length from main frame joint to front wheel center Lr: Length from subframe joint to rear wheel center rf: Front wheel Radius rr ... Rear wheel radius Lx ... Horizontal distance Lx0 from front wheel center to rear wheel center ... Horizontal distance Lz from front wheel center to rear wheel center in standard state ... From front wheel center to rear wheel center Vertical distance Lz0 of the vertical distance from the center of the front wheel to the center of the rear wheel in the standard state... Angle β between the main frame and the subframe. Angle γ ... An angle formed by a straight line passing through the joint and the power source center of gravity G with respect to the main frame. Location 10 is in a state to assist walking pedestrian plane path, special features of the walking assist device 10 is that the state does not operate.

Next, with reference to FIG. 10, the definition of the dimension of a level | step difference or staircase is demonstrated.
hn... nth step height dn... nth step depth length In the following description, the “step” is equal to or longer than the front-rear length (Lx0 + rf + rr) of the walking assist device 10 in the standard state. The “step” is a step having a depth less than the front-rear length (Lx0 + rf + rr) of the walking assist device 10 in the standard state.

With reference to FIG. 11, the attitude | position recognition method of the walking assistance apparatus 10 is demonstrated. In the present embodiment, as the posture of the walking assistance device 10, an angle β, a wheel-to-wheel horizontal distance Lx, and a wheel-to-wheel vertical distance Lz are calculated.
β = α−γ
Lx = Lfsinγ + Lrsinβ
Lz = Lrcosβ-Lfcosγ
Here, α is a detection value of the frame angle sensors 30L and 30R, γ is a detection value of the hanging angle sensor 32, and Lf and Lr are known values.

In addition, with reference to FIG. 11, a method for calculating the shape of a step or staircase will be described. In the present embodiment, the step height hn and the step depth dn are calculated as the step or staircase shape.
hn = Lrcosβ-Lfcosγ + rr-rf = Lz-Lz0
dn = Lrsinβ + Lfsinγ + rf−rr = Lx + rf−rr
Here, α is a detection value of the frame angle sensors 30L and 30R, γ is a detection value of the hanging angle sensor 32, and Lf, Lr, rf and rr are known values.

  Furthermore, with reference to FIG. 11, the determination method which determines the propriety of the climbing step of the walking assistance apparatus 10 is demonstrated. In the present embodiment, the walking assist device 10 has a function of determining whether or not a step can be raised for the front wheels 20FL and 20FR and a function of determining whether or not a step can be raised for the rear wheels 20RL and 20RR.

  For the front wheels 20FL and 20FR of the walking assistance device 10, it is determined whether or not the angle β is smaller than the minimum allowable angle βmin when the walking assistance device 10 is tilted. When the angle β is smaller than the minimum allowable angle βmin, it is determined that the step up is impossible because the walking assist device 10 is in an unstable state. On the other hand, when the angle β is larger than the minimum allowable angle βmin, the walking assist device 10 is in a stable state, so that it is determined that the step can be climbed.

  As for the rear wheels 20RL and 20RR of the walking assist device 10, the steps are performed in a state where the front wheels 20FL and 20FR are in contact with the n + 1-th step wall surface and the rear wheels 20RL and 20RR are in contact with the n-th step wall surface. It is determined whether or not the depth length dn is smaller than the minimum allowable length dmin. If the step depth length dn is smaller than the minimum allowable length dmin, it is determined that the step up is impossible because the walking assist device 10 is in an unstable state. On the other hand, when the step depth length dn is larger than the minimum allowable length dmin, the walking assist device 10 is in a stable state, and thus it is determined that the step can be climbed.

  Next, with reference to FIGS. 12-18, the process of the walking assistance apparatus 10 is demonstrated. FIG. 12 shows an outline of the processing of the walking assist device 10.

  As shown in FIG. 12, in step 1201, the controller 12 d determines that the walking assistance device 10 has collided with a step or stairs based on the output torque of the joint actuators 19 </ b> L and 19 </ b> R. That is, as shown in FIG. 13, when the walking assist device 10 collides with a step or a staircase, the torque acting on the joints 18L and 18R increases rapidly due to the reaction force received by the front wheels 20FL and 20FR from the step or the staircase. Therefore, the output torque of the joint actuators 19L and 19R necessary for keeping the frame angle constant increases rapidly. The controller 12d detects a sudden increase in the output torque of the joint actuators 19L and 19R, and determines that the walking assist device 10 has collided with a step or a staircase.

  In Step 1202, the controller 12d determines whether or not the front wheels 20FL and 20FR can move up the steps. Here, when the front wheels 20FL and 20FR can go up the step, the controller 12d controls the walking assist device 10 so that the front wheels 20FL and 20FR go up the step. On the other hand, the controller 12d ends the process when the front wheels 20FL and 20FR cannot move up the steps.

  In step 1203, the controller 12d determines whether the front road surface shape is a step or a staircase. When the road surface shape ahead is a staircase, the controller 12d proceeds to step 1204 and determines whether or not the rear wheels 20RL and 20RR can go up the staircase. When the rear wheels 20RL and 20RR can go up the stairs, the controller 12d goes to step 1205 and goes up the stairs. On the other hand, the controller 12d ends the process when the rear wheels 20RL and 20RR cannot go up the stairs.

  If the controller 12d determines in step 1203 that the front road surface shape is a step, the process proceeds to step 1206. In Step 1206, the controller 12d controls the walking assist device 10 so that the rear wheels 20RL and 20RR are stepped up.

  Next, the processing of step 1202, step 1203, and step 1204 will be described in more detail. The detailed process of step 1202 is shown in FIG. 14, the detailed process of step 1203 is shown in FIG. 17, and the detailed process of step 1204 is shown in FIG.

  If a step (step) is detected in step 1201, the controller 12d proceeds to the process of step 1401 shown in FIG. 14 and stops the walking assist device 10 on the spot. In Step 1402, the controller 12d determines whether or not the staircase mode switch 12a of the controller 12d has been pressed by a pedestrian. When the staircase mode switch 12a of the controller 12d is pushed by a pedestrian, the controller 12d proceeds to the processing of step 1403 and controls the front in-wheel motors 20FL and 20FR so that the front wheels 20FL and 20FR move forward. The rear in-wheel motors 20RL and 20RR are brake-controlled so that the side wheels 20RL and 20RR stop. By this control, the front wheels 20FL and 20FR of the walking assistance device 10 go up the wall surface of the step (step).

  In step 1404, the controller 12d repeatedly calculates the angle β and the vertical distance Lz while the front wheels 20FL and 20FR of the walking assist device 10 are moving up the wall surface. In step 1405, the controller 12d determines whether or not the angle β exceeds the minimum allowable angle βmin. Here, when the controller 12d determines that the angle β is smaller than the minimum allowable angle βmin as shown in FIG. 15, the controller 12d proceeds to the processing of step 1408 to increase the step (step) of the front wheels 20FL, 20FR. Judged as impossible.

  On the other hand, if the controller 12d determines that the angle β is greater than the minimum allowable angle βmin, the controller 12d proceeds to the processing of step 1406, calculates the differential value d / d (Lz) of the vertical distance Lz, and calculates the vertical distance Lz. It is determined whether or not the differential value is approximately zero. Here, when the differential value of the vertical distance Lz is substantially 0, the controller 12d is in a state where the front wheels 20FL and 20FR are stepped up (steps) as shown in FIG. , 20FR is determined to be possible to rise. On the other hand, when the differential value of the vertical distance Lz is greater than 0, the controller 12d returns to the processing of step 1403 because the front wheels 20FL and 20FR are still on the way of steps (steps). Continue climbing the steps (steps) of 20FL and 20FR.

  FIG. 17 shows the processing of step 1203 of FIG. In Step 1701, in the state where the front wheels 20FL and 20FR are in the n-th stage and the rear wheels 20RL and 20RR are in the (n-1) -th stage, the controller 12d has the same front wheels 20FL and 20FR and the rear wheels 20RL and 20RR. The front in-wheel motors 20FL and 20FR and the rear in-wheel motors 20RL and 20RR are driven and controlled to advance at a speed. In Step 1702, the controller 12d calculates the n-th wall surface height hn.

  In Step 1703, the controller 12d determines whether the front wheels 20FL and 20FR are in contact with the (n + 1) th stage wall surface first or the rear wheels 20RL and 20RR are in the nth stage based on the output torque of the joint actuators 19L and 19R. It is determined whether it is first to contact the wall surface. Here, the controller 12d proceeds to the processing of step 1704 when the front wheels 20FL and 20FR are in contact with the n + 1-th wall surface first, and the rear wheels 20RL and 20RR are moved to the n-th wall surface. If the contact is first, the process proceeds to step 1714.

  In step 1704, the controller 12d performs braking control on the front in-wheel motors 20FL and 20FR so that the front wheels 20FL and 20FR are stopped, and the rear in-wheel motors 20RL and 20RR so that the rear wheels 20RL and 20RR move forward. Is controlled. With this control, the rear wheels 20RL and 20RR approach the n-th wall surface while the front wheels 20FL and 20FR are in contact with the n + 1-th wall surface. In Step 1705, the controller 12d repeatedly determines whether or not the angle β is larger than the minimum allowable angle βmin while the rear wheels 20RL and 20RR are approaching the n-th wall surface. Here, the controller 12d proceeds to the processing of Step 1706 when the angle β is smaller than the minimum allowable angle βmin, and proceeds to the processing of Step 1708 when the angle β is larger than the minimum allowable angle βmin.

  In step 1706, the angle β is smaller than the minimum allowable angle βmin, and the walking assist device 10 is unstable. Therefore, the controller 12d causes the front in-wheel motor 20FL to stop the front wheels 20FL, 20FR and the rear wheels 20RL, 20RR. , 20FR and rear in-wheel motors 20RL, 20RR are brake controlled. In step 1707, the controller 12d determines that the step is a “staircase” having a depth less than the longitudinal length (Lx0 + rf + rr) of the walking assist device 10.

  In Step 1708, the controller 12d recognizes that the rear wheels 20RL and 20RR are in contact with the n-th wall surface based on the output torque of the joint actuators 19L and 19R. In Step 1709, the controller 12d controls the front in-wheel motors 20FL, 20FR and the rear in-wheel motors 20RL, 20RR so as to stop the front wheels 20FL, 20FR and the rear wheels 20RL, 20RR. In step 1710, the controller 12d calculates an n-th depth length dn.

  In step 1711, the controller 12d determines whether or not the n-th depth length dn is smaller than the front-rear length (Lx0 + rf + rr) of the walking assist device 10 in the standard state. Here, if the depth length dn at the n-th stage is smaller than the front-rear length (Lx0 + rf + rr) of the walking assist device 10 in the standard state, the controller 12d proceeds to the processing of step 1712 and proceeds to the front-rear length ( It is determined that it is a “staircase” having a depth length less than Lx0 + rf + rr). On the other hand, when the depth length dn at the n-th stage is larger than the front-rear length (Lx0 + rf + rr) of the walking assist device 10 in the standard state, the controller 12d proceeds to the processing of step 1713, and the front-rear length (Lx0 + rf + rr) ) It is determined that it is a “step” having the depth length described above.

  Returning to the above-described processing, when the processing proceeds from step 1703 to step 1714, in step 1714, the controller 12d drives and controls the front in-wheel motors 20FL, 20FR so that the front wheels 20FL, 20FR move forward. The rear in-wheel motors 20RL and 20RR are brake-controlled so that the rear wheels 20RL and 20RR stop. With this control, the front wheels 20FL and 20FR approach the n + 1-th wall surface while the rear wheels 20RL and 20RR are in contact with the n-th wall surface. In Step 1715, the controller 12d repeatedly calculates the horizontal distance Lx while the front wheels 20FL and 20FR are approaching the (n + 1) th stage wall surface.

  In Step 1716, the controller 12d determines whether or not the horizontal distance Lx is greater than the standard horizontal distance Lx0. Here, if the controller 12d determines that the horizontal distance Lx is smaller than the horizontal distance Lx0, the controller 12d proceeds to the processing of step 1713, and the “step difference” having a depth length equal to or longer than the front-rear length (Lx0 + rf + rr) of the walking assist device 10 Is determined.

  On the other hand, if the controller 12d determines that the horizontal distance Lx is greater than the horizontal distance Lx0, the controller 12d proceeds to the processing of step 1717, and the front wheels 20FL, 20FR are moved to n + 1 stages based on the output torque of the joint actuators 19L, 19R. Recognize contact with the eye wall. In Step 1718, the controller 12d calculates the n-th depth length dn. In step 1719, the controller 12d determines that the step is a “staircase” having a depth less than the longitudinal length (Lx0 + rf + rr) of the walking assist device 10.

  FIG. 18 shows the processing of step 1204 of FIG. In Step 1801, the controller 12d determines whether or not the n-th depth length dn is larger than the minimum allowable depth length dmin. Here, if the depth length dn of the n-th stage is larger than the minimum allowable depth length dmin, the controller 12d proceeds to the processing of step 1802 and determines that the rear wheels 20RL and 20RR can be stepped up. On the other hand, when the depth length dn of the n-th stage is smaller than the minimum allowable depth length dmin, the controller 12d proceeds to the processing of step 1803 and determines that the rear wheels 20RL and 20RR cannot be stepped up.

  As described above, according to the walking assistance device according to the second embodiment, when the walking assistance device reaches the step or the stairs, it is determined whether the walking assistance device can go up the step or the stairs. By doing so, it is possible to assist the walking of the pedestrian while maintaining the walking assist device in a stable state.

(Third embodiment)
Next, with reference to FIGS. 19-21, the walking assistance apparatus 10 which concerns on 3rd Embodiment is demonstrated.

  When the pedestrian collapses and falls back, the lightweight walking assist device 10 cannot support the pedestrian, and the pedestrian may fall. At this time, the walking assist device 10 receives a force from the pedestrian, and the front wheels 20FL and 20FR may float while the rear wheels 20RL and 20RR are in contact with the ground, and may fall with the pedestrian. In order to cope with such a situation, the walking assistance device 10 according to the third embodiment prevents the pedestrian and the walking assistance device 10 from falling when the pedestrian collapses and falls back. Has a fall prevention function. Below, the fall prevention function of the walking assistance apparatus 10 is demonstrated.

  FIG. 19 shows a state change of the walking assist device 10 when the pedestrian collapses and falls back. The state of the walking assistance device 10 is changed from the standard use state shown in FIG. 19A to the first use state corresponding to the pedestrian fall shown in FIG. It changes to the 2nd use state corresponding to the fall of the pedestrian shown by c).

  The walking assist device 10 has a special structure in order to change to the first use state (FIG. 19B) corresponding to the pedestrian falling. In the walking assist device 10, the upper portions of the main frames 14L, 14R above the joints 18L, 18R (hereinafter referred to as the main frame upper portion) 14La, 14Ra are the joints 18L, 14R of the main frames 14L, 14R in a standard use state. A portion below 18R (hereinafter referred to as a main frame lower portion) 14Lb, 14Rb is integrated. However, if it is determined that the pedestrian falls, the main frame upper portions 14La and 14Ra and the main frame lower portions 14Lb and 14Rb are unlocked according to a control signal from the controller 12d, and the main frame upper portions 14La and 14La, 14Ra is separated from the main frame lower portions 14Lb and 14Rb. In response to the control signal from the controller 12d, the main frame upper portions 14La and 14Ra are locked and integrated with the support member 38 of the power supply unit 22, and then the main frame upper portions 14La and 14Ra and the power supply unit 22 are integrated. This is free to rotate with respect to the joints 18L and 18R. Hereinafter, the integrated main frame upper portions 14La and 14Ra and the power supply unit 22 are referred to as a fixed body of the main frame upper portions 14La and 14Ra and the power supply unit 22.

  When the pedestrian collapses and falls back, the main frame upper portions 14La and 14Ra and the fixed body of the power supply unit 22 center around the joints 18L and 18R as the pedestrian pulls the handle 12 backward. (See FIG. 19B). At this time, since the power supply unit 22 rotates forward, an inertial reaction force corresponding to the rotation of the power supply unit 22 having a large mass instantaneously acts on the pedestrian from the handle 12. This inertial reaction force can suppress the pedestrian from falling backward and stabilize the pedestrian's posture.

  Moreover, in the 1st use state of the walking assistance apparatus 10, since the fixing body of main frame upper part 14La, 14Ra and the power supply unit 22 rotates with respect to joint 18L, 18R, the force with which a pedestrian pulls the handle | steering wheel 12 is each wheel. Since it is not transmitted to 20FL, 20FR, 20RL, and 20RR, it is possible to prevent the front wheels 20FL and 20FR from being lifted and to prevent the pedestrian and the walking assistance device 10 from falling. In particular, in the first usage state of the walking assist device 10, the power supply unit 22 moves forward, so that the ground load on the front wheels 20FL, 20FR increases. Therefore, the front wheels 20FL and 20FR can be prevented from rising, and the pedestrian and the walking assistance device 10 can be prevented from falling.

  In the second usage state corresponding to the pedestrian falling (FIG. 19C), the walking assistance device 10 fixes the main frame upper portions 14La, 14Ra and the power source unit 22 to the joints 18L, 18R, The front wheels 20FL and 20FR are brake controlled and the rear wheels 20RL and 20RR are moved rearward. As a result, the height of the handle 12 is lowered and the distance between the front wheels 20FL and 20FR and the rear wheels 20RL and 20RR is increased. As a result, the moment acting on the walking assist device 10 from the pedestrian is reduced, and the front side It is possible to prevent the wheels 20FL and 20FR from being lifted and to prevent the pedestrian and the walking assistance device 10 from falling.

It can be described with reference to FIG. 20 that the front wheels 20FL and 20FR are prevented from being lifted by the second use state of the walking assist device 10. Floating force acting on the front wheels 20FL, 20FR when the pedestrian pulling the handle 12 is F, the distance from the front wheel center to the rear wheel center is L, and the height of the handle 12 from the road surface is H Ff is expressed by the following equation.
Ff = H / L × F
According to this formula, when the handle height H is reduced and the wheel-to-wheel distance L is increased due to the second use state of the walking assist device 10, the floating force Ff of the front wheels 20FL, 20FR is reduced. it can.

  Next, with reference to FIG. 21, the process of the walking assistance apparatus 10 which concerns on 3rd Embodiment is demonstrated.

  In Step 2101, the controller 12 d takes in the detection value of the pressing force sensor 26. In Step 2102, the controller 12d determines whether or not the pedestrian has fallen backward based on the magnitude of the pressing force detected by the pressing force sensor 26 or the rate of change over time. Here, if it is determined that the pedestrian is falling backward, the controller 12d proceeds to the process of step 2103. On the other hand, if it is not determined that the pedestrian has fallen backward, the controller 12d returns to the process of step 2101 and repeats the determination of the pedestrian falling.

  In Step 2103, the controller 12d brakes all the wheels 20FL, 20FR, 20RL, and 20RR to fix the position of the walking assist device 10. In Step 2104, the controller 12d freely rotates the fixed bodies of the main frame upper portions 14La and 14Ra and the power supply unit 22 with respect to the joints 18L and 18R. Thereby, since an inertial reaction force acts on the pedestrian from the handle 12, the pedestrian is prevented from falling backward.

  In Step 2105, the controller 12d determines whether or not the main frame upper portions 14La and 14Ra and the fixed body of the power supply unit 22 have rotated by a predetermined angle threshold value or more. Here, when the fixed body has not rotated more than the angle threshold value, the controller 12d returns to the process of step 2104 and continues the state in which the fixed body is freely rotatable. On the other hand, when the fixed body has rotated more than the angle threshold value, the controller 12d proceeds to the process of step 2106.

  In Step 2106, the controller 12d fixes the main frame upper portions 14La and 14Ra and the power source unit 22 to the joints 18L and 18R. In step 2107, the controller 12d brakes the front wheels 20FL and 20FR and moves the rear wheels 20RL and 20RR rearward. As a result, the height H of the handle 12 can be reduced, the distance L between the wheels can be increased, and the front wheels 20FL and 20FR can be prevented from being lifted, thereby preventing the pedestrian and the walking assistance device 10 from falling.

  In Step 2108, the controller 12d determines whether or not the pedestrian is still falling. Here, when the pedestrian is still falling, the controller 12d returns to the process of step 2107 and continues to move the rear wheels 20RL and 20RR backward. On the other hand, when the pedestrian has recovered his / her posture without falling down, the controller 12d proceeds to the processing of step 2109 and returns the posture of the walking assist device 10 to the initial position.

(1st Embodiment) It is a perspective view which shows the external appearance of a walking assistance apparatus. It is a side view which shows the external appearance of a walking assistance apparatus. It is a block diagram which shows a walking assistance apparatus. It is the 1st explanatory view showing posture change of a walk auxiliary device. It is the 2nd explanatory view showing posture change of a walk auxiliary device. It is a flowchart which shows speed control of a walking assistance apparatus. It is a flowchart which shows the speed control of the walking assistance apparatus in a downhill. It is a figure which shows the usage method of the walk assistance apparatus in an uphill. (2nd Embodiment) It is a figure which shows the dimension of each part of a walking assistance apparatus. It is a figure which shows the dimension of a level | step difference or a staircase. It is a figure which shows the walk assistance apparatus which goes up a level | step difference or a staircase. It is a flowchart which shows the movement control of the walking assistance apparatus in a level | step difference or a staircase. It is explanatory drawing for demonstrating the detection method of a level | step difference or a staircase. 13 is a flowchart for explaining step 1202 in FIG. 12 in detail. It is 1st explanatory drawing for demonstrating the determination method of the possibility of passage of a level | step difference or a staircase. It is the 2nd explanatory view for explaining the judgment method of the possibility of passage of a level difference or a stair. 13 is a flowchart for explaining step 1203 in FIG. 12 in detail. 14 is a flowchart for explaining step 1204 in FIG. 12 in detail. (Third Embodiment) It is a diagram showing a change in use state of the walking assistance device. It is explanatory drawing for demonstrating the difficulty of falling of a walking assistance apparatus. It is a flowchart which shows the use condition control of a walking assistance apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Walking assistance apparatus, 12 ... Handle, 12a, 12b, 12c ... Switches, 12d ... Controller, 14L, 14R ... Main frame, 16L, 16R ... Subframe, 18L, 18R ... Joint, 19L, 19R ... Joint actuator, 20FL, 20FR, 20RL, 20RR ... wheels (in-wheel motor unit), 22 ... power supply unit, 24L, 24R ... band, 26 ... pressing force sensor, 30L, 30R ... frame angle sensor, 32 ... hanging angle sensor, 36 ... Support belt, 38 ... support member.

Claims (14)

A handle that extends horizontally to the road surface at a height that can be gripped by a pedestrian,
A main frame extending from the handle to the vicinity of the road surface obliquely downward on the front side of the pedestrian,
A subframe extending from the middle part of the main frame to the road surface in the vicinity of the pedestrian,
A joint that is provided in the middle part of the main frame and rotatably connects the sub frame to the main frame;
A power supply unit suspended from the joint;
A front wheel provided at a lower end near the road surface of the main frame and driven by electric power from the power supply unit;
A rear wheel provided at a lower end in the vicinity of the road surface of the subframe and driven by electric power from the power supply unit;
A controller for controlling each of the front wheel and the rear wheel;
A walking assistance device comprising:   The walking assist device according to claim 1, wherein the controller adjusts a height of the handle from a road surface by adjusting a relative distance between the front wheel and the rear wheel. The front wheel includes a left front wheel and a right front wheel, and the rear wheel includes a left rear wheel and a right rear wheel,
The controller independently adjusts the relative distance between the left front wheel and the left rear wheel, and the relative distance between the right front wheel and the right rear wheel, thereby adjusting the inclination in the left-right direction of the walking assist device. The walking assistance device according to claim 1, wherein the walking assistance device is characterized in that A pressing force sensor for detecting a pressing force applied to the handle by the pedestrian,
The controller controls the front wheel and the rear wheel so that a pressing force applied to a handle by a pedestrian is substantially constant based on a pressing force detected by the pressing force sensor. The walking assist device according to any one of Items 1 to 3. A slope sensor for detecting the slope of the road surface;
The controller changes a pressing force threshold range for making the pressing force applied to the handle by the pedestrian substantially constant based on the gradient detected by the gradient sensor, and controls the front wheel and the rear wheel. The walking assist device according to claim 4, wherein   The walking assistance device according to any one of claims 1 to 5, further comprising a support band having both ends fixed to the joint and hung on a waist of a pedestrian.   The walking assist device according to claim 1, wherein the controller is provided on the handle. A first angle sensor for detecting an angle α formed by the sub-frame with respect to the main frame;
A second angle sensor for detecting an angle γ formed by the power supply unit with respect to the main frame;
With
The walking assist device according to claim 1, wherein the controller recognizes the posture of the walking assist device based on the angles α and β detected by the first angle sensor and the second angle sensor.   The walking assist device according to claim 8, wherein the controller determines whether or not the walking assist device can get over a step or stairs based on a recognition result of a posture of the walking assist device.   The walking assist device according to claim 8, wherein the controller calculates a shape of a step or a staircase based on a recognition result of a posture of the walking assist device.   The said controller determines that the said front wheel or the said rear wheel contacted the level | step difference or the staircase based on the torque which acts on the said joint, The any one of Claims 8-10 characterized by the above-mentioned. Walking assist device. The main frame is separated into an upper part from the handle to the joint and a lower part below the joint, and the upper part is centered on the joint independently of the lower part. It is configured to be rotatable,
When the controller determines that the pedestrian falls to the rear, the main frame and the power unit are integrated, the power unit is forward and the upper portion of the main frame is rearward, with the joint as a center. The walking assist device according to claim 1, wherein the walking assist device is rotated.   The walking assist device according to claim 12, wherein the controller rotates the sub-frame backward when it is determined that the pedestrian falls backward. A pressing force sensor for detecting a force applied to the handle by the pedestrian, and
The walking assist device according to any one of claims 12 to 13, wherein the controller determines whether the pedestrian falls backward based on a force detected by the pressing force sensor.

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