JP2009189428A - Walking assisting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prove an electromotive walking assisting device achieving the enhancement of storability. <P>SOLUTION: The walking assisting device 1 is constituted of main frames 3a and 3b extending downward from a handle 2, sub-frames 4a and 4b extending to the downward rear side from the main frames 3a and 3b, joint parts 5a and 5b for connecting the sub-frames 4a and 4b to the main frames 3a and 3b in a freely revolvable manner, the left and right wheels 7a-7d respectively provided to the lower ends of the main frames 3a and 3b and the sub-frames 4a and 4b, and in-wheel motors 8a-8d for respectively independently rotationally driving the respective wheels 7a-7d. The distance L1 from the joint parts 5a and 5b in the main frames 3a and 3b to the centers of the front wheels 7a and 7b is shorter than the distance L2 from the joint parts 5a and 5b in the sub-frames 4a and 4b to the rear wheels 7c and 7d. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a foldable handcart type walking assist device.

As a conventional handcart type walking assist device, for example, as described in Patent Document 1, when a handle is moved in a direction desired by a pedestrian, a force applied to the handle is detected, and the detection is performed. 2. Description of the Related Art A walking assistance device that assists the walking of a pedestrian by adjusting the driving of a wheel by comparing a value with a target value is known. In addition, as described in Patent Document 2, there is a walking assist vehicle that can be folded.
Japanese Patent No. 3156367 JP 2001-224642 A

  However, since the electric wheelbarrow type walking assist device described in Patent Document 1 has a configuration in which each part is fixed, there is a problem that it is difficult to store. In that respect, the walking auxiliary vehicle described in Patent Document 2 can be compactly stored by folding, but since it does not have a drive unit for driving wheels, it is considered that a battery, a control unit, and the like are mounted. Absent. Therefore, there is a demand for an electric walking assist device that is excellent in storability.

  Accordingly, an object of the present invention is to provide an electric walking assist device capable of improving storage performance.

  The present invention relates to a handle gripped by a pedestrian, a pair of main frames extending downward from the handle, a pair of sub frames extending downward from each main frame, and each sub frame relative to each main frame. A pair of joint portions that are pivotably connected to each other, a control unit that is suspended from the joint portion, a pair of front wheels provided at the lower end of each main frame, and a lower end of each subframe. A pair of rear wheels, and a plurality of drive units that independently rotate and drive the pair of front wheels and the pair of rear wheels, and the subframe can be folded with respect to the main frame via the joint unit. The distance from the joint part in the main frame to the center part of the front wheel is Characterized in that it is shorter than the distance to the center of.

  In the walking assistance device according to the present invention, the distance from the joint part in the main frame to the center part of the front wheel is shorter than the distance from the joint part in the sub frame to the center part of the rear wheel. Thereby, when the sub-frame is folded to the main frame side, for example, the drive unit can be stored compactly without interfering with the control unit. Further, in a state in which the sub frame is folded with respect to the main frame, only the rear wheels are grounded, and it is possible to travel with only two wheels. Therefore, even if the control unit is provided, the storage property can be improved, and the movement to the storage location can be suitably performed.

  Preferably, in the folded state of the subframe with respect to the main frame, the distance between the centers of the front wheels and the rear wheels is greater than 0, and the sum of the distance between the centers of the front wheels and the rear wheels and the radius of the front wheels. Is longer than ½ of the longitudinal length of the control unit.

  In this case, even when the subframe is folded with respect to the main frame, the balance of the walking assist device is favorably maintained, so that it is possible to prevent the vehicle from falling forward. Further, even if the walking assistance device is likely to fall down, the front wheel is located at a position that can be a cushioning material for the control unit, so that the control unit can be prevented from being damaged.

  Preferably, the steering wheel is provided with a left and right operation unit for instructing a straight or turning operation, a determination unit for determining whether the sub frame is folded with respect to the main frame, and a sub unit by the determination unit. And a means for controlling the drive unit corresponding to each rear wheel according to the operation direction of the two operation units when it is determined that the frame is folded with respect to the main frame.

  When it is determined by the determining means that the sub-frame is folded with respect to the main frame, the drive unit corresponding to the rear wheel is controlled according to the operation directions of the two operation units. For example, when the right operation unit is pushed, the vehicle turns to the left by increasing the driving force of the right rear wheel. Therefore, the movement to the direction which a pedestrian intends can be assisted reliably. Further, when the subframe is folded, only the rear wheels are driven and the front wheels are not driven, so that power consumption can be suppressed.

  Preferably, the angle detection means for detecting the rotation angle of the joint portion, and the load estimation means for estimating the load of the front wheel and the rear wheel based on the rotation angle of the joint portion detected by the angle detection means. And means for controlling each drive unit based on the loads on the front wheels and the rear wheels estimated by the load estimating means when the judging means judges that the subframe is not folded with respect to the main frame. And further comprising.

  When it is determined by the determining means that the subframe is not folded with respect to the main frame, each drive unit is assigned to each drive unit based on the front wheel and rear wheel loads estimated based on the rotation angle of the joint unit. By determining the driving force to be applied and distributing the driving force for each wheel, driving efficiency can be increased and power consumption can be suppressed.

  According to the walking assist device of the present invention, it is possible to improve the storage property. Thereby, the convenience of a pedestrian can be improved.

  Hereinafter, a preferred embodiment of a walking assistance device according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view showing an appearance of an embodiment of a walking assistance device according to the present invention. In the figure, a walking assist device 1 is a foldable electric wheelbarrow that assists a pedestrian to walk. The walking assist device 1 includes a handle 2 held by a pedestrian, main frames 3a and 3b, subframes 4a and 4b, joint portions 5a and 5b, a control unit 6, main frames 3a and 3b, and subframes 4a, Left and right wheels 7a to 7d attached to 4b, in-wheel motors 8a to 8d for independently rotating and driving the wheels 7a to 7d, and a right controller bar 9a and a left controller bar 9b provided on the handle 2 It is configured.

  As shown in FIG. 2, the handle 2 is provided with the two controller bars 9a and 9b for instructing and operating the straight movement operation and the turning operation of the walking assist device 1 so that they can be pushed in the front-rear direction. The handle 2 is provided with a mode setting switch 11 (see FIG. 5). A region R between the right controller bar 9a and the left controller bar 9b is a dead zone, and for example, when a pedestrian operates with one hand, the vehicle can keep going straight.

  The pair of main frames 3 a and 3 b extend from both ends of the handle 2 obliquely downward on the front side. A pair of front wheels 7a and 7b are rotatably attached to the tips (lower ends) of the main frames 3a and 3b.

  The pair of sub-frames 4a and 4b extend from the joint portions 5a and 5b provided at substantially the center portions of the main frames 3a and 3b toward the lower rear side. A pair of rear wheels 7c and 7d are rotatably attached to the tips (lower ends) of the sub-frames 4a and 4b.

  The pair of joint portions 5a and 5b rotatably connect the sub frames 4a and 4b to the main frames 3a and 3b. The joint portions 5a and 5b include rotation motors 13a and 13b (see FIG. 5) for rotating (opening and closing) the sub-frames 4a and 4b with respect to the main frames 3a and 3b, and the joint portions 5a and 5b, An angle sensor 12 (see FIG. 5) for detecting the rotation angle of 5b and a rotation damper (not shown) as vibration damping means for attenuating the impact in the rotation direction at the joint portions 5a and 5b are provided.

  The rotary damper improves the detection accuracy of the angle sensor 12 by attenuating the impact of the joint portions 5a and 5b. Further, the rotary damper can suppress the vibration of the control unit 6 suspended from the joint portions 5a and 5b, and can improve the running stability.

  An ECU 14 and a power supply unit 15 (see FIG. 5) are provided inside the control unit 6. The control unit 6 also has a luggage compartment for storing luggage. The center of the control unit 6 is on the same straight line as the centers of the joint portions 5a and 5b.

  Then, with reference to FIG.3 and FIG.4, the dimension of the walking assistance apparatus 1 is demonstrated in detail. FIG. 3 is a side view showing dimensions of each part of the walking assist device 1 in a normal running state in which the sub frames 4a and 4b are opened with respect to the main frames 3a and 3b. FIG. 4 is a side view showing dimensions of each part of the walking assistance device 1 in a state where the sub frames 4a and 4b are closed (folded) with respect to the main frames 3a and 3b. Below, the dimension of each part is shown.

L1: Distance from the center of the joints 5a, 5b to the center of the front wheels 7a, 7b in the main frames 3a, 3b L2: The center of the rear wheels 7c, 7d from the center of the joints 5a, 5b in the subframes 4a, 4b WB: Distance between the centers of the front wheels 7a, 7b and the rear wheels 7c, 7d during normal travel of the walking assist device 1 Rf: Radius of the front wheels 7a, 7b Lo: Horizontal distance in the front-rear direction of the control unit 6 θ: rotation angle formed by the straight lines passing through the centers of the joint portions 5a, 5b and the center of the control unit 6 and the sub frames 4a, 4b WB ′: front wheels 7a, 7b and rear wheels when the walking assist device 1 is folded Center distance between 7c and 7d

The dimensions of each part of the walking assist device 1 shown in FIG. 4 satisfy the following conditions (1) to (4).
L1 <L2 (1)
WB '> 0 (2)
WB '+ Rf> Lo / 2 (3)
θ = 0 (4)
In the condition (4), the joint portions 5a and 5b are fixed so as not to rotate by the rotation motors 13a and 13b.

  FIG. 5 is a block diagram showing a control system for controlling the in-wheel motors 8a to 8d. In FIG. 5, the walking assist device 1 includes a right pushing force sensor 10a, a left pushing force sensor 10b, a mode setting switch 11, an angle sensor 12, rotation motors 13a and 13b, and an ECU (Electronic Control Unit) 14. And a power supply unit 15.

  The right pushing force sensor 10a and the left pushing force sensor 10b are sensors that respectively detect front and back pushing forces of the controller bars 9a and 9b pushed by a pedestrian. Detection signals (pressing force signals) from the right pressing force sensor 10a and the left pressing force sensor 10b are sent to the ECU 14.

  The mode setting switch 11 is a switch for setting a normal traveling mode and a folding mode. The normal travel mode is a mode in which the walking assist device 1 travels with four wheels. The folding mode is a mode in which the walking assist device 1 travels on the rear two wheels. A mode switching signal of the mode setting switch 11 is sent to the ECU 14.

  FIG. 6 shows a side view of the walking assist device 1 that travels in the folding mode. In the folding mode, since only the rear wheels 7c and 7d are grounded, the in-wheel motors 8c and 8d are driven, and the in-wheel motors 8a and 8b corresponding to the front wheels 7a and 7b are not driven. In the folding mode, the position of the control unit 6 is higher than that in the normal traveling mode, so that it is possible to assist over the stairs. In the folding mode, the walking assist device 1 assists the movement in the direction (arrow direction) intended by the pedestrian by operating the controller bars 9a and 9b as in the normal travel mode.

  The angle sensor 12 is a sensor that detects a rotation angle at which the sub frames 4a and 4b are folded toward the main frames 3a and 4b in the joint portions 5a and 5b. A detection signal (angle signal) of the angle sensor 12 is sent to the ECU 14.

  The rotation motors 13a and 13b are motors for rotating the sub frames 4a and 4b. The rotation motors 13a and 13b are provided in the joint portions 5a and 5b, and fold the sub-frames 4a and 4b with respect to the main frames 3a and 3b based on the mode switching signal sent from the ECU 14 to Set to folding mode. Moreover, based on the mode switching signal sent from ECU14, rotation motor 13a, 13b returns the walk assistance apparatus 1 from folding mode to normal driving mode.

  The ECU 14 determines whether or not the subframes 4a and 4b are folded with respect to the main frames 3a and 3b based on the mode switching signal sent from the mode setting switch 11, and the in-wheel motors 8a to 8b are determined according to the result. 8d is controlled.

Moreover, ECU14 estimates the load of front-and-rear wheels 7a-7d based on the angle signal sent from the angle sensor 12, determines the driving force given to the in-wheel motors 8a-8d, and determines each wheel 7a-7b. Control to distribute the driving force. Specifically, the driving force of the in-wheel motors 8a to 8d is obtained by the following equation (5), where Tf is the torque of the front wheels 7a and 7b and Tr is the torque of the rear wheels 7c and 7d.
Tf / Tr = 1 / (1 + θ−θa) (5)
Therefore, θ = θa when horizontal, and therefore Tf / Tr = 1 when the walking assist device 1 travels at a constant speed. Further, when the walking assist device 1 is folded, Tf: Tr = 0: 1.

  FIG. 7 is a flowchart showing details of a processing procedure executed by the ECU 14.

  In FIG. 7, first, it is determined whether the walking assistance device 1 is not folded based on the mode setting switch 11 (step S01). If it is determined that the walking assist device 1 is not folded, the process proceeds to step S02. On the other hand, if it is determined that the walking assist device 1 is folded, the process proceeds to step S07.

  When it is determined in step S01 that the walking assist device 1 is not folded, an angle signal is input from the angle sensor 12 (step S02). Subsequently, the loads on the front and rear wheels 7a to 7d are estimated based on the angle signal from the angle sensor 12 (step S03). When the loads on the front and rear wheels 7a to 7d are estimated, push force signals from the push force sensors 10a and 10b are input (step S04). Then, based on the estimated load and push force signals, a rotational torque command value is calculated so as to cause the walking assist device 1 to go straight or turn in consideration of the distribution ratio of the driving force for the in-wheel motors 8a to 8d (procedure S05). ), The process proceeds to step S06.

  In step S06, an in-wheel motor drive signal corresponding to the rotational torque command value obtained in step S05 is sent to the in-wheel motors 8a to 8d to control driving of the in-wheel motors 8a to 8d.

  On the other hand, when it is determined in step S01 that the walking assistance device 1 is folded, the push force signals from the push force sensors 10a and 10b are input (step S07). Subsequently, based on the pressing force signals from the pressing force sensors 10a and 10b, a rotation torque command value for causing the walking assist device 1 to go straight or turn is obtained (step S08), and the process proceeds to step S09.

  In step S09, an in-wheel motor drive signal corresponding to the rotational torque command value obtained in step S08 is sent to the rear in-wheel motors 8c and 8d to control driving of the in-wheel motors 8c and 8d.

  In the above, the in-wheel motors 8a to 8d constitute a plurality of drive units that respectively rotate and drive the wheels 7a to 7d independently. The controller bars 9a and 9b are provided on the handle 2 and constitute two left and right operation units for instructing a straight traveling or turning operation. The mode setting switch 11 and the procedure S01 of the ECU 14 constitute determination means for determining whether or not the sub frames 4a and 4b are folded with respect to the main frames 3a and 3b. Steps S08 and 09 of the ECU 14 are performed in accordance with the operation directions of the two controller bars 9a and 9b when the determination unit determines that the subframes 4a and 4b are folded with respect to the main frames 3a and 3b. A means for controlling the in-wheel motors 8c and 8d corresponding to the side wheels 7c and 7d is configured. The angle sensor 12 constitutes angle detection means for detecting the rotation angle of the joint portions 5a and 5b. Steps S02 and 03 of the ECU 14 constitute load estimation means for estimating the loads on the front wheels 7a and 7b and the rear wheels 7c and 7d based on the rotation angles of the joint portions 5a and 5b detected by the angle sensor 12. is doing. In steps S05 and 06 of the ECU 14, the front wheels 7a and 7b and the rear wheels estimated by the load estimation unit when the determination unit determines that the sub frames 4a and 4b are not folded with respect to the main frames 3a and 3b. A means for controlling the in-wheel motors 8a to 8d is configured based on the loads of the side wheels 7c and 7d.

  As described above, in the walking assist device 1 of the present embodiment, the distance L1 from the center of the joint portions 5a and 5b to the center of the front wheels 7a and 7b in the main frames 3a and 3b is the same in the subframes 4a and 4b. The configuration is shorter than the distance L2 from the center of the joint portions 5a and 5b to the center of the rear wheels 7c and 7d (L1 <L2). Thereby, when the sub-frames 4a and 4b are folded toward the main frames 3a and 3b, the in-wheel motors 8a to 8d and the like can be stored compactly without interfering with the control unit 6. Therefore, even if the control unit 6 is provided, the storage property can be improved.

  In addition, in a state where the sub frames 4a and 4b are folded with respect to the main frames 3a and 3b, only the rear wheels 7c and 7d are grounded, and the vehicle can travel with only two wheels. At this time, since the sub-frames 4a and 4b are fixed by the joint portions 5a and 5b, the stability of the two-wheel running can be improved and the loads on the rear wheels 7c and 7d can be stabilized. Therefore, the movement to a storage place can be performed suitably.

  Further, in a state where the subframes 4a and 4b are folded, the in-wheel motors 8c and 8d corresponding to the rear wheels 7c and 7d are controlled according to the operation direction of the controller bars 9a and 9b. Thereby, the movement to the direction which a pedestrian intends can be assisted reliably.

  The present invention is not limited to the above embodiment. For example, in the above embodiment, the rotation motors 13a and 13b are controlled by the mode switching signal of the mode setting switch 11 and the walking assist device 1 is folded, but the mode setting switch 11 and the rotation motors 13a and 13b are not provided. For example, the sub-frames 4a and 4b are folded with respect to the main frames 3a and 3b by rotating or stopping the front wheels 7a and 7b in the backward direction and rotating the rear wheels 7c and 7d in the forward direction. Also good. In this case, the subframes 4a and 4b are fixed at the joint portions 5a and 5b by, for example, a mechanical lock mechanism.

It is a perspective view which shows the external appearance of one Embodiment of the walk assistance apparatus concerning this invention. It is a figure which shows the detailed structure of a handle. It is a side view which shows the dimension of each part of a walking assistance apparatus. It is a side view which shows the dimension of each part of the state by which the walking auxiliary device was folded. It is a block diagram which shows the control system which controls an in-wheel motor. It is a side view which shows the walk assistance apparatus which drive | works in folding mode. It is a flowchart which shows the detail of the process sequence performed by ECU.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Walking assistance apparatus, 2 ... Handle, 3a, 3b ... Main frame, 4a, 4b ... Sub-frame, 5a, 5b ... Joint part, 6 ... Control unit, 7a-7d ... Wheel (front wheel, rear wheel), 8a to 8d: in-wheel motor (drive unit), 9a, 9b: control bar (operation unit), 12: angle sensor (angle detection unit), 14: ECU (determination unit, load estimation unit).

Claims (4)

A handle that a pedestrian grips,
A pair of main frames extending downward from the handle;
A pair of subframes extending from each main frame toward the lower rear side;
A pair of joint portions that rotatably connect the sub-frames to the main frames;
A control unit provided suspended from the joint part;
A pair of front wheels provided at the lower end of each main frame;
A pair of rear wheels provided at the lower end of each subframe;
A plurality of drive units for independently rotating and driving the pair of front wheels and the pair of rear wheels;
With
The distance from the joint portion in the main frame to the center portion of the front wheel is from the joint portion in the subframe so that the subframe can be folded with respect to the main frame via the joint portion. A walking assist device characterized by being shorter than the distance to the center of the rear wheel.   In the folded state of the sub-frame with respect to the main frame, the center distance between the front wheel and the rear wheel is greater than 0, and the center distance between the front wheel and the rear wheel and the radius of the front wheel, The walking assist device according to claim 1, wherein the sum is longer than ½ of the longitudinal length of the control unit. Two left and right operation units provided on the handle for instructing a straight or turning operation;
Determining means for determining whether the sub-frame is folded with respect to the main frame;
Means for controlling the drive unit corresponding to each of the rear wheels according to the operation direction of the two operation units when the determination unit determines that the sub-frame is folded with respect to the main frame. When,
The walking assist device according to claim 1, further comprising: Angle detection means for detecting the rotation angle of the joint part;
Load estimating means for estimating the loads of the front wheel and the rear wheel based on the rotation angle of the joint part detected by the angle detecting means;
When the determining means determines that the sub-frame is not folded with respect to the main frame, the driving is performed based on the loads of the front wheels and the rear wheels estimated by the load estimating means. Means for controlling the unit,
The walking assist device according to claim 3, further comprising:

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