JP2003052758A - Method and system for controlling power assist mechanism for care giver for omnidirectional movable motor-driven wheelchair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for controlling power assist mechanism for a care giver for omnidirectional movable motor-driven wheelchair with which the burden of the care giver to push an omnidirectional movable motor-driven wheelchair provided with a power assist mechanism for the care giver can be reduced. SOLUTION: When the care giver is to move the omnidirectional movable motor-driven wheelchair by pushing it, a moving direction desired by the care giver is read by a power sensor, a required power assist quantity is automatically calculated, and an electric motor in the four-wheel driving part of the omnidirectional movable motor-driven wheelchair is operated. Thus, the omnidirectional movable motor-driven wheelchair can be moved at a desired speed in the desired arbitrary moving direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and system for controlling a power assist mechanism for a caregiver of an omnidirectional mobile electric wheelchair, and more particularly to an omnidirectional mobile electric wheelchair capable of moving in all directions. The present invention relates to a method and a system for controlling a power assist mechanism which is attached to the omnidirectional mobile electric wheelchair and assists the caregiver when the caregiver pushes and moves it.

[0002]

2. Description of the Related Art Conventional so-called electric wheelchairs are provided with a power assist mechanism that assists the caregiver's pushing force by moving the wheelchair only by rotating the wheels with an electric motor. It was common to move a wheelchair with the assistance of a mechanism, but even those equipped with a power assist mechanism, those that move in one direction in a straight line were the mainstream.

[0003]

Therefore, in recent years, there has been proposed an omnidirectional mobile electric wheelchair equipped with a power assist mechanism for any direction such as sideways, turning, and diagonal, that is, all directions. Since the directional mobile electric wheelchair does not have an input device for the caregiver that is effective for controlling the travel, traveling of the omnidirectional mobile electric wheelchair by the caregiver imposes a heavy burden on the caregiver, and In the case of so-called long-term care in which the old man takes care of an elderly man with a more severe disability, there is a problem that the burden increases.

The present invention has been made in view of the above circumstances, and an object thereof is to reduce the burden on a caregiver who pushes an omnidirectional mobile electric wheelchair having a power assist mechanism for a caregiver. It is an object of the present invention to provide a control method and system for a power assist mechanism for a caregiver of a direction-movable electric wheelchair.

[0005]

In order to achieve the above object, a method of controlling a power assist mechanism for a caregiver of an omnidirectional electric wheelchair according to claim 1 is an omnidirectional electric motor that can move in all directions. A method for controlling a power assist mechanism which is attached to the omnidirectional mobile electric wheelchair and assists the caregiver when the caregiver moves a wheelchair by pushing a handwheel of the omnidirectional mobile electric wheelchair, the method comprising: When a caregiver pushes the handwheel handle to move the omnidirectional mobile electric wheelchair, the force sensor mounted on the handwheel handle reads the direction in which the caregiver wants to move, and the necessary power assist amount is automatically calculated. Then, the electric motor of the four-wheel drive unit of the omnidirectional mobile electric wheelchair is operated, and thereby the omnidirectional mobile electric wheelchair is desired. Characterized in that so as to move in the movement direction and speed at will.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of an omnidirectional mobile electric wheelchair to which the present invention is applied will be described below in detail with reference to FIGS. As shown in FIG. 2, in this omnidirectional mobile electric wheelchair, four wheels 23 and 24 arranged in a cross shape as a power assist mechanism are rotatably mounted on a wheelchair body 22. Each of 23 and 24 is configured as an omni wheel having a plurality of free rollers pivotally supported on the outer circumference, and is movable in all directions.
A control device 25 as a system for controlling the power assist mechanism is provided on the backrest of the wheelchair body 22.
Is attached.

This controller 25, as shown in FIG.
A 6-axis force sensor 1 that is mounted on the backrest of the omnidirectional mobile electric wheelchair 21 and a push handle 26 and reads the direction of the force pushed by the caregiver, and based on information from the 6-axis force sensor 1, A personal computer 2 as a calculation means for calculating the power assist amount required for a caregiver to push and move the omnidirectional mobile electric wheelchair 21, and the omnidirectional mobile electric wheelchair based on the calculation result of the personal computer 2. The motor driver 3 drives an electric motor 27 for driving four wheels 21 and an encoder 4 as a rotation speed detecting means for detecting the rotation speed of the electric motor 27. And the electric motor 2
The output shaft of 7 is connected to the wheels 23 and 24 through a gear box 28 as a transmission means.

The 6-axis force sensor 1 takes the forward / backward direction of the omnidirectional electric wheelchair 21 as the Z-axis, the forward / backward direction to the right as the Y-axis, and the vertical direction as the X-axis, and The moment around each axis is also taken in, and the coordinate system is based on each forward or left turn as the positive direction.

With such a structure, when the caregiver pushes the hand handle 26 to move the omnidirectional electric wheelchair 21 in any direction, the 6-axis force sensor 1
Reads the direction the caregiver wants to move, and the personal computer 2 automatically calculates the required power assist amount based on the information read by the 6-axis force sensor 1 and sends it to the motor driver 3. The motor driver 3 uses the electric motor 27 based on the calculation result of the personal computer 2.
Is rotated forward or backward, and at the same time the encoder 4
Detects the number of rotations of the electric motor 27 and detects the motor driver 3
Send to. This allows the caregiver to move the omnidirectional mobile wheelchair 21 in any desired direction at a desired speed.

In order to make the above operation suitable,
The 6-axis force sensor 1 performs coordinate conversion on the sensing position, and causes the center of the hand push handle 26 to move to the center of gravity of the omnidirectional electric wheelchair 21 according to the coordinate system. That is, as shown in FIG. 3A, a coordinate axis in which the forward direction of the omnidirectional mobile electric wheelchair 21 is the positive direction of the Z axis, the right lateral moving direction is the positive direction of the Y axis, and the left turning direction is the positive direction of θ. in accordance with,
Further, as shown in FIG. 3B, P _B is the center of gravity of the omnidirectional mobile electric wheelchair 21, P _S is the center of the 6-axis force sensor 1 (sensing position), P _H is the center of the steering wheel (power point),
Let f _yH and M _{xH be the} force and moment applied to the handle center P _H , respectively.

In order to examine the force acting on the center of gravity P _B of the omnidirectional mobile electric wheelchair 21, it is assumed that the omnidirectional mobile electric wheelchair 21 is laterally moved and turned without using a power assist mechanism. The force f _yH applied to the center P _H of the handle and the moment M _xH applied to the center P _H of the handle are calculated and expressed in a graph as shown in FIG. From this figure 4, when the omnidirectional-type electric wheelchair 21 is moved transversely and swiveling, it can be seen that each of the center P _H f _yH and M _xH handles is acting. This result can be easily proved by mechanical analysis.

That is, as shown in FIG.
Moment due to friction M_{f ri}To offset
Statement M_xHNeed to be added. Also, turn
Is f _yHMoment M caused by_xBAlone
Ku, M_xHTo make it easier to turn. That is, turning
Sometimes f has the same sign_yHAnd M _xHWill be added,
F with a different sign when moving laterally_yHAnd M_xHWill be added
It This result uses the power assist mechanism shown in FIG.
If not, i.e., make lateral movement, turning, etc. naturally
It is the same as when operating. As a result, the omnidirectional mobile electric
The movement of the wheelchair 21 can be made more suitable.
Will be

[0013]

As apparent from the above description, the present invention is
A method for controlling a power assist mechanism which is attached to the omnidirectional mobile electric wheelchair and assists the caregiver when a caregiver pushes and moves an omnidirectional mobile electric wheelchair that is movable in all directions, comprising: When a caregiver pushes and moves the omnidirectional mobile electric wheelchair, the direction in which the caregiver wants to move is read by a force sensor and the necessary power assist amount is automatically calculated to calculate the omnidirectional mobile electric wheelchair. Operate the electric motor of the four-wheel drive,
Since the omnidirectional mobile electric wheelchair is moved in any desired moving direction and speed, the burden on the caregiver pushing the omnidirectional mobile electric wheelchair equipped with the power assist mechanism for the caregiver can be appropriately set. It can be reduced and has excellent practical effects.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a side view of an omnidirectional mobile electric wheelchair to which the present invention is applied.

FIG. 3 is a relationship diagram showing a relationship between a force and a moment acting on a center of a steering wheel when an omnidirectional mobile electric wheelchair is laterally moved and turned.

FIG. 4 is an explanatory view showing a force and a moment applied to the center of a steering wheel when an omnidirectional mobile electric wheelchair is laterally moved and turned without using a power assist mechanism.

[Explanation of symbols]

1 6-axis force sensor 2 personal computer 3 motor driver 4 encoder 21 Omni-directional mobile electric wheelchair 26 handwheel 27 electric motor

Claims (5)

[Claims] [Claim 1] When a caregiver moves an omnidirectional mobile electric wheelchair that is movable in all directions by pushing a handwheel handle of the omnidirectional mobile electric wheelchair, the caregiver is attached to the omnidirectional mobile electric wheelchair. A method for controlling a power assist mechanism for assisting a person, wherein when the caregiver pushes the handwheel handle to move the omnidirectional mobile wheelchair, the caregiver attaches a desired direction in which the caregiver should move. The omnidirectional mobile electric wheelchair is operated by operating the electric motor of the four-wheel drive unit of the omnidirectional mobile electric wheelchair by automatically reading the required power assist amount by the read force sensor. A method for controlling a power assist mechanism for a caregiver of an omnidirectional mobile electric wheelchair, which is characterized in that it is moved in any desired moving direction and speed. 2. The control method for a care giver power assist mechanism for an omnidirectional mobile electric wheelchair according to claim 1, wherein the force sensor has a center of the handwheel handle and a center of gravity of the omnidirectional mobile electric wheelchair. A method for controlling a power assist mechanism for a caregiver of an omnidirectional mobile electric wheelchair, which is characterized by conforming to a coordinate system that has been moved to. 3. When the caregiver moves an omnidirectional mobile electric wheelchair that is movable in all directions by pushing a handwheel handle of the omnidirectional mobile electric wheelchair, the caregiver is attached to the omnidirectional mobile electric wheelchair. A system for controlling a power assist mechanism for assisting a person, wherein the force sensor is mounted on the backrest portion and the manual handle of the omnidirectional mobile electric wheelchair to read the direction of the force pushed by the caregiver,
Based on the information from the 6-axis force sensor, the caregiver calculates a power assist amount required to push and move the omnidirectional mobile electric wheelchair, and the total calculation result of the calculation means. Directional movement type electric wheelchair 4
Control of a power assist mechanism for a carer of an omnidirectional electric wheelchair, characterized by including a motor driver for driving an electric motor for wheel drive, and a rotation speed detecting means for detecting a rotation speed of the electric motor. system. 4. The control system for a power assist mechanism for a carer of an omnidirectional mobile electric wheelchair according to claim 3, wherein the force sensor is a 6-axis force sensor. Electric wheelchair operation restriction system. 5. The control system for a power assist mechanism for a carer of an omnidirectional mobile electric wheelchair according to claim 3 or 4, wherein the force sensor has the omnidirectional mobile electric wheelchair centered on the handwheel handle. A control system for a power assist mechanism for a caregiver of an omnidirectional electric wheelchair characterized by following a coordinate system that is moved to the center of gravity of.