JP2014073354A - Motorization unit for manual vehicle, method for controlling motorization unit for manual vehicle, electric wheelchair, and method for controlling electric wheelchair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motorization unit for a manual vehicle using active casters, a method for controlling the motorization unit for the manual vehicle, an electric wheelchair, and a method for controlling the electric wheelchair.SOLUTION: An electric wheelchair 100 has: two wheels 13 for manual operation; a body part 27 installed to a frame 12; a leg part 23 rotatable around a turning axis R; a drive wheel 21 disposed rotatably around a drive axis Q; a first electric motor 25 rotating the drive wheel 21; a second electric motor rotating the leg part; an operation part 230 operating a travel; and a control part driving the first electric motor 25 and the second electric motor on the basis of a signal outputted by the operation of the operation part 230.

Description

  The present invention relates to a motorized unit for a manual vehicle using an omnidirectional moving mechanism, a method for controlling the motorized unit for a manual vehicle, an electric wheelchair, and a method for controlling an electric wheelchair.

  With the recent change to an aging society, demand for mobility support devices is expected to increase more and more. In particular, electric wheelchairs include not only disabled people but also elderly people as users, and their needs are expanding and diversifying. Typical examples include a handle type electric wheelchair (so-called senior car) and a joystick type electric wheelchair. These electric wheelchairs have four wheels having a smaller diameter than a manual wheelchair, and two of these wheels are driven wheels by an electric motor. In general, an electric wheelchair is not easy to carry by a method other than self-propelled because the weight of the device itself is large.

  On the other hand, a type of wheelchair that can be moved electrically but is relatively light and convenient for transportation has recently attracted attention, and its market has been expanding. Such a wheelchair is a type in which a motorized unit is mounted on the basis of a manual wheelchair, and is called a simple electric wheelchair (for example, see Patent Documents 1 to 5).

  The advantages of simple electric wheelchairs are that they are lighter and simpler than those designed and manufactured as electric wheelchairs, and are often cheaper overall. In addition, a large storage battery is not stacked under the seat like an electric wheelchair, and the motor is downsized, so that it can be folded like a conventional manual wheelchair. For this reason, by using a system for loading a wheelchair on the roof of a car, a disabled person can easily load the wheelchair into the car.

  Since the simple electric wheelchair is not equipped with a large-capacity storage battery, the movement distance per charge is shorter than that of the electric wheelchair. However, since it is based on the structure of a manual wheelchair, it is also a great feature that it can be moved by hand if it cannot be moved electrically.

  Most of the simple electric wheelchairs on the market are those in which the driving wheels (large-diameter wheels with hand trims) of manual wheelchairs are replaced with electric wheel units to which a motor is attached (for example, Non-Patent Document 1). 2). Such a simple electric wheelchair adjusts and controls when controlling two electric motors attached to both wheels, because the deviation of the load and the slight difference in motor characteristics affect the behavior of the wheelchair. It is considered that there are potential difficulties. In addition, since the wheel diameter is large, the motor of the electric unit tends to increase in size in order to cope with low speed and high torque.

The wheel of such an electric wheelchair or a simple electric wheelchair usually has four wheels and has a configuration of two front and rear wheels. As a driving method of the simple electric wheelchair, a rear wheel drive type in which a large rear wheel is driven by an electric motor is mainly used, and basically a turning operation similar to that in manual operation is performed. In such a rear-wheel drive type, the power of the motor is directly transmitted to the drive wheels of the rear wheels, so that when accelerating at a large acceleration, the reaction of rotating the front wheels in the direction of lifting the wheel in the wheelchair frame There is a risk that it will become a so-called wheelie or fall backward, contrary to the pilot's intention. In particular, when climbing a hill, the phenomenon is likely to occur. Therefore, in the rear-wheel drive type, it is necessary to set a strict limit on the acceleration of movement, which may hinder agile operation. On the other hand, there are two types of driving methods for electric wheelchairs: a front wheel drive type in which two front wheels are driven by an electric motor, and a reverse rear wheel drive type. In any drive system, basically, a so-called caster is used in which the drive wheels do not turn and the non-drive wheels turn freely. The turning center of the wheelchair is the center of the two drive wheels, which is unique to the wheelchair drive structure and cannot be changed.

  Further, active casters that are omnidirectional moving mechanisms that can move with a driving force generated in an arbitrary direction by one wheel have been proposed (for example, Non-Patent Documents 3, 4, 5 and Patent Documents 6, 7). Such an active caster has a wheel arrangement similar to that of a passively operated caster (that is, the turning axis and the wheel axis do not intersect), and the wheel axis and the turning axis (steering axis) are driven by independent actuators. Thus, it is a wheel mechanism that can be used as a driving wheel of a moving body. By cooperatively controlling the rotation of the wheel axis and the turning axis, it is possible to generate a velocity vector in the center of the turning axis in all directions within the horizontal plane. Therefore, since it can move instantly in various directions regardless of the direction of the wheels, there is a feature that a very flexible movement can be generated even with a single wheel. However, there is an idea to replace all the wheels of a vehicle that cannot move in a direction orthogonal to the traveling direction like a manual wheelchair with an omnidirectional moving mechanism to make the wheelchair movable in all directions (see, for example, Patent Document 8). However, there was no idea that a simple electric wheelchair using an omnidirectional movement mechanism would perform the same operation as a manual wheelchair.

JP-A-9-122184 JP 2003-19165 A JP 2009-284944 A JP 2011-110404 A JP 2009-279118 A Japanese Patent Laid-Open No. 9-164968 JP 2001-199356 A JP 2000-175969 A

Imasen Technical Research Laboratories Co., Ltd., Manual Combined Type (Wheelchair Electrification Unit) DP-45 / 60 Daily Pal, [Search August 30, 2012], Internet <URL: http: // www. imasengenken. co. jp / emc / dailypal. html> Yamaha Motor Co., Ltd. website, wheelchair electric unit JWX-1, [searched on August 30, 2012], Internet <URL: http: // www. yamaha-motor. jp / wherehair / unit / jwx1 /> M.M. Wada and S.W. Mori, “Holonic and Omnidirectional Vehicle with Conventional Tires,” Proceedings of the 1996 IEEE International Conference on Robotics and Automation (IC361). M.M. Wada, A .; Takagi and S.M. Mori, “Caster Drive Mechanism for Holonic and Omnidirectional Mobile Platforms with no Over Continent,” Proceedings of the 2000. Masayoshi Wada, 2 others, “Study on Active Casters Using Spherical Power Transmission Mechanism”, No. 12-2 Robotics Symposia Proceedings, The Japan Society of Mechanical Engineers, March 13, 2012, pages 181 to 186

  An object of the present invention is to provide a motorized unit for a manual vehicle using an active caster, a method for controlling the motorized unit for a manual vehicle, an electric wheelchair, and a method for controlling an electric wheelchair.

An electrification unit for a manual vehicle according to the present invention includes:
A body portion attachable to a manual vehicle having at least two wheels arranged on the same rotational axis;
A leg portion rotatably attached to the main body portion around a pivot axis;
A drive wheel having a drive shaft disposed at a predetermined distance from the pivot shaft, and being rotatably attached to the leg portion around the drive shaft;
A first electric motor that rotates the drive wheel relative to the leg;
A second electric motor that rotates the leg with respect to the main body;
An operation unit for operating the traveling of the manual vehicle;
A control unit that drives the first electric motor and the second electric motor based on a signal output by an operation of the operation unit;
Have
When the motorized unit is attached to the manual vehicle, the control unit inputs a signal output from the operation unit as a command value for the straight traveling speed V and a command value for the turning speed Ω of the manual vehicle. Based on (1), a first angular velocity ω _{w at} the drive axis of the drive wheel and a second angular velocity ω _s at the pivot axis of the leg are calculated, and the first angular velocity ω _w is output. Then, the first electric motor is driven, and the second angular speed ω _s is output to drive the second electric motor.

(Where r is the radius of the drive wheel and s is the separation distance. The rotation axis of the two wheels is the Y axis, and the midpoint between the two wheels on the Y axis is the origin. When a manual vehicle coordinate system having an imaginary straight line perpendicular to the Y axis as the X axis is set in the horizontal plane, φ is an angle formed by the traveling direction of the drive wheel with respect to the X axis (straight direction of the manual vehicle), x , Y is the position of the turning axis in the manual vehicle coordinate system, and x is not 0.)

  According to the electrification unit of the manual vehicle according to the present invention, the same operation as that of the manual vehicle can be generated by the electric motor by incorporating the electrification unit including the omnidirectional movement mechanism into the manual vehicle. Therefore, even a user of a conventional manual vehicle can electrically operate the manual vehicle to which the electrification unit according to the present invention is attached without a sense of incongruity.

A method for controlling a motorized unit of a manual vehicle according to the present invention includes:
An electrification unit that moves by rotating the drive wheel around a drive axis by an electric motor and changes the direction of movement of the drive wheel by rotating the drive wheel around a turning axis by an electric motor Is attached to a manual vehicle having at least two wheels disposed on the same rotational axis.
From the command value of the straight speed V of the manual vehicle and the command value of the turning speed Ω, the first angular speed ω _w in the drive axis and the second angular speed ω _s in the turning axis based on the following equation (1). To calculate
Rotating said drive wheel about the drive axis in the first angular velocity omega _w,
Characterized in that it rotates about the pivot axis of the drive wheel in the second angular velocity omega _s.

(Where r is the radius of the drive wheel, s is the separation distance between the pivot axis and the drive axis. Also, the rotation axis of the two wheels is the Y axis, and 2 on the Y axis. When a manual vehicle coordinate system with the midpoint between the two wheels as the origin and an imaginary straight line perpendicular to the Y axis as the X axis is set in the horizontal plane, φ is the drive with respect to the X axis (straight direction of the manual vehicle) (An angle formed by the traveling direction of the wheel, x, y is the position of the turning axis in the manual vehicle coordinate system, and x is not 0.)

  According to the method for controlling an electrification unit of a manual vehicle according to the present invention, the same operation as that of the manual vehicle can be generated by an electric motor by incorporating the electrification unit including the omnidirectional movement mechanism into the manual vehicle. Therefore, even a user of a conventional manual vehicle can electrically operate the manual vehicle to which the electrification unit according to the present invention is attached without a sense of incongruity.

The electric wheelchair according to the present invention is
A seat,
A frame for fixing the seat;
Two manual wheels mounted on the frame so as to be rotatable on the same axis of rotation with the seat interposed therebetween;
A main body attached to the frame;
A leg that is rotatable about a pivot axis relative to the body;
A drive wheel having a drive shaft disposed at a predetermined separation distance with respect to the pivot shaft, and disposed so as to be rotatable around the drive shaft with respect to the leg portion;
A first electric motor that rotates the drive wheel relative to the leg;
A second electric motor that rotates the leg with respect to the main body;
An operation unit for operating the vehicle;
A control unit that drives the first electric motor and the second electric motor based on a signal output by an operation of the operation unit;
An electric wheelchair having
The control unit inputs the signal output from the operation unit as a command value for the straight traveling speed V and a command value for the turning speed Ω of the electric wheelchair, and based on the following formula (1), the drive shaft of the drive wheel The first angular velocity ω _{w at the} center and the second angular velocity ω _s at the pivot axis of the leg are calculated, the first angular velocity ω _w is output to drive the first electric motor, and The driving wheel is rotated, the second angular velocity ω _s is output to drive the second electric motor, and the traveling direction of the electric wheelchair is changed.

(Where r is the radius of the drive wheel and s is the separation distance. Also, the rotation axis of the two manual wheels is the Y axis, and the two manual wheels on the Y axis are When the wheelchair coordinate system is set in the horizontal plane with the midpoint between them as the origin and the imaginary straight line perpendicular to the Y-axis as the X-axis, φ is the direction of travel of the drive wheel with respect to the X-axis (The angle formed, x, y is the position of the pivot axis in the wheelchair coordinate system, and x is not 0.)

  According to the electric wheelchair according to the present invention, by including the omnidirectional movement mechanism, the same operation as that of the manual wheelchair can be generated by the electric motor. Therefore, even a user of a conventional manual wheelchair can electrically operate the electric wheelchair according to the present invention without a sense of incongruity. In addition, since there is no turning axis of the drive wheel on the rotation axis of the manual wheel (in formula (1), x is not 0), it is possible to obtain excellent posture stability of the electric wheelchair particularly during acceleration. it can.

In the electric wheelchair according to the present invention,
Two driven wheels supported by the frame;
A restraining mechanism for restraining the turning motion of the driven wheel;
An actuator for moving the frame relative to the main body and changing the manual wheel between a grounded state and a non-grounded state;
Further comprising
Directing the driven wheel in the straight direction of the electric wheelchair, and in a state where the two driven wheels are positioned on the same rotational axis, the restraint mechanism is driven to restrain the turning operation of the driven wheel,
The actuator is driven to change the turning center of the electric wheelchair from the midpoint between the manual wheels to the midpoint between the driven wheels by setting the manual wheel to an ungrounded state, and the control unit includes: The signal output from the operation unit is input as a command value for the straight traveling speed V _{2 and} a command value for the turning speed Ω ₂ of the electric wheelchair at the midpoint between the driven wheels, and the formula (1) is expressed by the following formula (5 ) And the traveling direction of the electric wheelchair can be changed based on the following formula (5).

(Where r is the radius of the driving wheel and s is the separation distance. Also, the rotation axis of the two driven wheels is the Y ₂ axis, and the _two driven wheels on the Y ₂ axis are when the second wheelchair coordinate system perpendicular imaginary straight line to the Y ₂ -axis and the X ₂ axis midpoint as the origin is set to the horizontal plane, the phi ₂ the slave with respect to the X ₂ axis (straight direction of the wheelchair) (An angle formed by the moving direction of the driving wheel, x ₂ , y ₂ is the position of the pivot axis in the wheelchair coordinate system, and x ₂ is not 0.)

An electric wheelchair control method according to the present invention includes:
Rotating the drive wheel around the drive axis by the electric motor and moving the drive wheel around the turning axis by the electric motor to change the moving direction of the drive wheel A method for controlling an electric wheelchair having two manual wheels on an axis,
From the command value of the straight speed V of the electric wheelchair and the command value of the turning speed Ω, the first angular velocity ω _w in the drive shaft center and the second angular speed ω _s in the turning shaft center based on the following equation (1). To calculate
Rotating said drive wheel about the drive axis in the first angular velocity omega _w,
Characterized in that it rotates about the pivot axis of the drive wheel in the second angular velocity omega _s.

(Where r is the radius of the drive wheel, s is the distance between the pivot axis and the drive axis, and the Y axis is the rotational axis of the two manual wheels. When a wheelchair coordinate system is set in the horizontal plane with the midpoint between the above two manual wheels as the origin and an imaginary straight line perpendicular to the Y axis as the X axis, φ is the X axis (the straight direction of the wheelchair ), X and y are the positions of the pivot axis in the wheelchair coordinate system, and x is not 0.)

  According to the method for controlling an electric wheelchair according to the present invention, by including an omnidirectional movement mechanism, the same operation as that of a manual wheelchair can be generated by an electric motor. Therefore, even a user of a conventional manual wheelchair can electrically operate the electric wheelchair according to the present invention without a sense of incongruity. In addition, since there is no turning axis of the drive wheel on the rotation axis of the manual wheel (in formula (1), x is not 0), it is possible to obtain excellent posture stability of the electric wheelchair particularly during acceleration. it can.

In the control method of the electric wheelchair according to the present invention,
The electric wheelchair further includes two driven wheels, a restraining mechanism that restrains the turning motion of the driven wheel, and an actuator that changes the manual wheel between a grounded state and a non-grounded state,
Directing the driven wheel in the straight direction of the electric wheelchair, and in a state where the two driven wheels are positioned on the same rotational axis, the restraint mechanism is driven to restrain the turning operation of the driven wheel,
The actuator is driven to change the turning center of the electric wheelchair from the midpoint between the manual wheels to the midpoint between the driven wheels while the manual wheels are ungrounded, and between the driven wheels. from the command value and the command value of the swing speed Omega ₂ of the linear velocity V ₂ of the electric wheelchair at the mid-point, it is possible to change a traveling direction of the electric wheelchair in accordance with the following equation (5).

(Where r is the radius of the driving wheel and s is the separation distance. Also, the rotation axis of the two driven wheels is the Y ₂ axis, and the _two driven wheels on the Y ₂ axis are when the second wheelchair coordinate system perpendicular imaginary straight line to the Y ₂ -axis and the X ₂ axis midpoint as the origin is set to the horizontal plane, the phi ₂ the slave with respect to the X ₂ axis (straight direction of the wheelchair) (An angle formed by the moving direction of the driving wheel, x ₂ , y ₂ is the position of the pivot axis in the wheelchair coordinate system, and x ₂ is not 0.)

It is a longitudinal cross-sectional view which shows typically the omnidirectional movement mechanism used for an electrification unit. It is a longitudinal cross-sectional view which shows typically the omnidirectional movement mechanism used for an electrification unit. It is a side view of the electric wheelchair which concerns on 1st Embodiment. 1 is a schematic plan view schematically showing an electric wheelchair according to a first embodiment. It is a block diagram for demonstrating an electrification unit. It is a cross-sectional view which shows typically a part of omnidirectional movement mechanism of the electric wheelchair which concerns on 2nd Embodiment. It is a schematic plan view which shows typically the electric wheelchair which concerns on 2nd Embodiment. It is a schematic side view which shows typically the electric wheelchair which concerns on 3rd Embodiment. It is a schematic side view which shows typically the electric wheelchair which concerns on 4th Embodiment. It is a photograph of the electric wheelchair which concerns on Example 1. FIG. It is a straight-ahead operation test measurement result of the electric wheelchair which concerns on Example 1. FIG. It is a turning operation test measurement result of the electric wheelchair which concerns on Example 1. FIG. It is a schematic plan view which shows the conventional wheelchair typically. It is a schematic plan view which shows typically the electric wheelchair which concerns on 5th Embodiment. It is a schematic plan view which shows typically the electric wheelchair which concerns on 5th Embodiment. It is a schematic side view which shows typically the electric wheelchair which concerns on 5th Embodiment. It is a rear view which shows typically the omnidirectional movement mechanism used for the electrification unit of the electric wheelchair which concerns on 5th Embodiment. It is a figure which shows the turning operation | movement simulation result of the electric wheelchair which concerns on 5th Embodiment. It is a figure which shows the turning operation | movement simulation result of the electric wheelchair which concerns on 5th Embodiment.

  Hereinafter, a method for controlling an electric wheelchair and an electric wheelchair according to an embodiment of the present invention, a method for controlling a motorized unit for a manual vehicle, and a method for controlling a motorized unit for a manual vehicle will be described with reference to the drawings. In addition, what is described below is an example of an embodiment of an electric wheelchair and an electric wheelchair control method, an electric unit for a manual vehicle, and a control method for an electric unit for a manual vehicle according to the present invention. It is not limited, and those skilled in the art can make various modifications within the scope of the technical idea described in the claims. In the present application, horizontal is a direction in a plane parallel to the floor surface on which the vehicle moves, and vertical is a direction perpendicular to the floor surface.

An electrification unit for a manual vehicle according to an embodiment of the present invention includes a main body that can be attached to a manual vehicle having at least two wheels disposed on the same rotational axis, and a pivot axis with respect to the main body. A leg portion rotatably attached around the center; and a drive axis centered at a predetermined distance from the pivot axis, the leg portion being around the drive axis A drive wheel that is rotatably mounted, a first electric motor that rotates the drive wheel relative to the leg, a second electric motor that rotates the leg relative to the main body, and the manual An operation unit that operates the vehicle, and a control unit that drives the first electric motor and the second electric motor based on a signal output by the operation of the operation unit, and the control The unit attaches the motorized unit to the manual vehicle. The signal output from the operation unit is input as a command value for the straight traveling speed V and a command value for the turning speed Ω of the manual vehicle, and the drive shaft of the drive wheel based on the following equation (1) calculating a second angular velocity omega _s of the first angular velocity omega _w and the pivot axis of the legs in the heart, and outputs the first angular velocity omega _w driving the first electric motor, the A second angular velocity ω _s is output to drive the second electric motor.

(Where r is the radius of the drive wheel and s is the separation distance. The rotation axis of the two wheels is the Y axis, and the midpoint between the two wheels on the Y axis is the origin. When a manual vehicle coordinate system having an imaginary straight line perpendicular to the Y axis as the X axis is set in the horizontal plane, φ is an angle formed by the traveling direction of the drive wheel with respect to the X axis (straight direction of the manual vehicle), x , Y is the position of the turning axis in the manual vehicle coordinate system, and x is not 0.)

A method for controlling a motorized unit of a manual vehicle according to an embodiment of the present invention is such that a drive wheel is moved by rotating around a drive axis by an electric motor, and the drive wheel is rotated by an electric motor. When the motorized unit that changes the moving direction of the driving wheel by rotating around the center is attached to a manual vehicle having at least two wheels arranged on the same rotational axis, the straight line of the manual vehicle Based on the command value of the speed V and the command value of the turning speed Ω, a first angular speed ω _w in the drive axis and a second angular speed ω _s in the turning axis are calculated based on the following equation (1): the drive wheel rotates around the drive axis in the first angular velocity omega _w, characterized by rotating the drive wheel about the pivot axis in the second angular velocity omega _s.

(Where r is the radius of the drive wheel, s is the separation distance between the pivot axis and the drive axis. Also, the rotation axis of the two wheels is the Y axis, and 2 on the Y axis. When a manual vehicle coordinate system with the midpoint between the two wheels as the origin and an imaginary straight line perpendicular to the Y axis as the X axis is set in the horizontal plane, φ is the drive with respect to the X axis (straight direction of the manual vehicle) (An angle formed by the traveling direction of the wheel, x, y is the position of the turning axis in the manual vehicle coordinate system, and x is not 0.)

An electric wheelchair according to an embodiment of the present invention includes a seat portion, a frame for fixing the seat portion, and two manual attachments that are rotatably attached to the frame on the same rotational axis with the seat portion interposed therebetween. Wheels, a main body portion attached to the frame, a leg portion rotatable around a pivot axis with respect to the main body portion, and a predetermined separation distance with respect to the pivot axis. A drive wheel that has a drive shaft center and is arranged to be rotatable around the drive shaft with respect to the leg, a first electric motor that rotates the drive wheel with respect to the leg, and travel A second electric motor for rotating the leg relative to the main body, and the first electric motor and the second electric motor based on a signal output by operating the operation unit. An electric wheelchair having a controller for driving the electric motor; Thus, the control unit inputs the signal output from the operation unit as a command value for the straight traveling speed V and a command value for the turning speed Ω of the electric wheelchair, and based on the following formula (1), A first angular velocity ω _{w at} the driving axis and a second angular velocity ω _s at the pivot axis of the leg are calculated, and the first angular motor ω _w is output to drive the first electric motor. Then, the driving wheel is rotated, the second angular velocity ω _s is output to drive the second electric motor, and the traveling direction of the electric wheelchair is changed.

(Where r is the radius of the drive wheel and s is the separation distance. Also, the rotation axis of the two manual wheels is the Y axis, and the two manual wheels on the Y axis are When the wheelchair coordinate system is set in the horizontal plane with the midpoint between them as the origin and the imaginary straight line perpendicular to the Y-axis as the X-axis, φ is the direction of travel of the drive wheel with respect to the X-axis (The angle formed, x, y is the position of the pivot axis in the wheelchair coordinate system, and x is not 0.)

In the electric wheelchair according to the embodiment of the present invention, two driven wheels supported by the frame, a restraining mechanism for restraining a turning operation of the driven wheel, and the frame relative to the main body portion. An actuator for moving the manual wheel between a grounded state and a non-grounded state, directing the driven wheel in a straight direction of the electric wheelchair, and rotating the two driven wheels in the same direction In a state of being positioned on the axis, the restraint mechanism is driven to restrain the turning operation of the driven wheel, the actuator is driven to bring the manual wheel to an ungrounded state, and the turning center of the electric wheelchair is While changing from the midpoint between the manual wheels to the midpoint between the driven wheels, the control unit converts the signal output from the operation unit to the straight traveling speed V of the electric wheelchair at the midpoint between the driven wheels. ₂ The command value and the command value of the turning speed Ω ₂ are input, the formula (1) is switched to the following formula (5), and the traveling direction of the electric wheelchair can be changed based on the following formula (5).

(Where r is the radius of the driving wheel and s is the separation distance. Also, the rotation axis of the two driven wheels is the Y ₂ axis, and the _two driven wheels on the Y ₂ axis are when the second wheelchair coordinate system perpendicular imaginary straight line to the Y ₂ -axis and the X ₂ axis midpoint as the origin is set to the horizontal plane, the phi ₂ the slave with respect to the X ₂ axis (straight direction of the wheelchair) (An angle formed by the moving direction of the driving wheel, x ₂ , y ₂ is the position of the pivot axis in the wheelchair coordinate system, and x ₂ is not 0.)

A method for controlling an electric wheelchair according to an embodiment of the present invention is such that an electric motor moves a drive wheel around a drive axis, and the electric motor moves the drive wheel around a turning axis. A method for controlling an electric wheelchair having two manual wheels on the same rotational axis, wherein the moving direction of the drive wheel is changed by rotating, wherein the command value and the turning speed of the straight speed V of the electric wheelchair From the command value of Ω, a first angular velocity ω _{w at} the drive shaft center and a second angular velocity ω _s at the pivot axis are calculated based on the following equation (1), and the drive wheel is moved to the first angular velocity. omega rotates about the drive axis at _w, is characterized by rotating the drive wheel about the pivot axis in the second angular velocity omega _s.

(Where r is the radius of the drive wheel, s is the separation distance between the pivot axis and the drive axis. Also, the rotation axis of the two wheels is the Y axis, and 2 on the Y axis. When a wheelchair coordinate system with the midpoint between the two wheels as the origin and an imaginary straight line perpendicular to the Y-axis as the X-axis is set in the horizontal plane, φ represents the driving wheel relative to the X-axis (straight direction of the wheelchair). (An angle formed by the traveling direction, x and y are positions of the pivot axis in the wheelchair coordinate system, and x is not 0)

In the method for controlling an electric wheelchair according to an embodiment of the present invention, the electric wheelchair includes two driven wheels, a restraining mechanism for restricting a turning operation of the driven wheel, and the manual wheel in a grounded state. An actuator for changing to a grounded state, with the driven wheel directed in a straight line direction of the electric wheelchair, and the two driven wheels positioned on the same rotational axis. Drive to restrain the turning movement of the driven wheel, drive the actuator to bring the manual wheel to an ungrounded state, and turn the turning center of the electric wheelchair from the midpoint between the manual wheels to the driven wheel From the command value of the straight speed V _{2 and} the command value of the turning speed Ω ₂ of the electric wheelchair at the mid point between the driven wheels, the progress of the electric wheelchair is based on the following equation (5). Change direction Can.

(Where r is the radius of the driving wheel and s is the separation distance. Also, the rotation axis of the two driven wheels is the Y ₂ axis, and the _two driven wheels on the Y ₂ axis are when the second wheelchair coordinate system perpendicular imaginary straight line to the Y ₂ -axis and the X ₂ axis midpoint as the origin is set to the horizontal plane, the phi ₂ the slave with respect to the X ₂ axis (straight direction of the wheelchair) (An angle formed by the moving direction of the driving wheel, x ₂ , y ₂ is the position of the pivot axis in the wheelchair coordinate system, and x ₂ is not 0.)

1. First, an outline of an omnidirectional moving mechanism (also called an active caster) that can be used in the present invention will be described. The omnidirectional movement mechanism can adopt a known structure, and the omnidirectional movement mechanism described here is merely an example. FIG. 1 is a longitudinal sectional view schematically showing an omnidirectional moving mechanism used in an electric unit. FIG. 2 is a longitudinal sectional view schematically showing an omnidirectional moving mechanism used in the motorized unit. Here, FIG. 1 is a longitudinal sectional view of the driving wheel 21 of the omnidirectional moving mechanism as viewed from the front (traveling direction), and FIG. 2 is a longitudinal sectional view of the driving wheel 21 of the omnidirectional moving mechanism as viewed from the side.

  The omnidirectional movement mechanism (active caster) that can be used in the present invention has a wheel arrangement similar to a passively operated caster (a caster used for office use), that is, the swivel axis and the wheel axis are It can have a wheel arrangement that does not intersect. Such an omnidirectional moving mechanism is, for example, a wheel mechanism that can be used as a driving wheel of a moving body by driving a wheel shaft of a caster and a turning shaft (steering shaft) by independent actuators. The omnidirectional movement mechanism can generate velocity vectors in all directions in the horizontal plane at the center of the steering axis by cooperatively controlling the rotation of the wheel axis and the steering axis. Therefore, since it can move instantly in various directions regardless of the direction of the wheels, there is a feature that a very flexible movement can be generated even with a single wheel. The present invention can realize the electrification unit 2 by one wheel of the drive wheel 21 by utilizing this feature.

  The drive wheel 21 also functions as a steering wheel, and is rotatably supported with respect to the leg portion 23 around a drive axis Q that is a steering shaft by an axle 22 that supports and fixes the drive wheel 21. Note that a pneumatic tire can be attached to the drive wheel 21. The axle 22 is connected to a first electric motor 25 that is an electric motor via a speed reducer 24. An encoder 26 is connected to the other end of the first electric motor 25 to detect the rotation angle of the drive wheel 21. By driving the first electric motor 25, the driving wheel 21 rotates around the driving axis Q, and the rolling direction of the driving wheel 21 (in FIG. 1, the front direction or the back direction in FIG. The main body 27 can be moved in the left-right direction in FIG.

  Further, the upper end of the leg portion 23 is supported by the main body portion 27 so as to be rotatable around a turning axis R extending in the vertical direction via a bearing 28. Here, the center of the bearing 28, that is, the pivot axis R of the leg portion 23, is a position offset from the ground contact position of the drive wheel 21 by a predetermined separation distance s in the horizontal direction. The separation distance s is the separation distance s between the turning axis R and the drive axis Q. More specifically, the separation distance s is the shortest distance between a virtual plane extending in the vertical direction from the ground contact surface including the drive axis Q and the turning axis R. For example, as shown in FIG. 1, the virtual turning axis center line extending the turning axis R downward can be set at a position passing through the center of the width of the drive wheel 21. This indicates that the turning axis R overlaps with an extension of the center line of the width of the drive wheel 21 in a plan view (for example, FIG. 6 can be referred to).

  A gear 29 is mounted on the upper surface of the leg 23 coaxially with the pivot axis R and is meshed with a gear 31 supported by the main body 27. The gear 31 is supported and fixed to an output shaft 33 of a second electric motor 32 that is an electric motor. An encoder 34 is connected to the other end of the second electric motor 32 to detect the rotation angle of the leg 23, that is, the steering angle. By driving the second electric motor 32, the leg 23 rotates around the turning axis R, and the driving wheel 21 at a position offset from the turning axis R by a separation distance s is placed on an arc having a radius s. Can be swiveled.

  Thus, by rotating the drive wheel 21 with the first electric motor 25 and steering with the second electric motor 32, the main body 27 can be moved back and forth, left and right, and this omnidirectional movement mechanism. It is possible to change the direction instantly in all directions.

2. First Embodiment FIG. 3 is a side view of an electric wheelchair 100 according to a first embodiment. FIG. 4 is a schematic plan view schematically showing the electric wheelchair 100 according to the first embodiment. FIG. 5 is a block diagram for explaining the electrification unit 2.

As shown in FIGS. 3 and 4, an electric wheelchair 100 includes a manual wheelchair 1 which is an example of a manual vehicle having at least two wheels arranged on the same rotation axis, and an electrification attached to the manual wheelchair 1. Unit 2 is included. The motorized unit 2 can be attached to a commercially available manual wheelchair 1 to form a so-called simple electric wheelchair, or the manual wheelchair 1 and the motorized unit 2 can be integrated in advance. Moreover, it can also be set as the structure which can attach or detach easily the connection part of the manual wheelchair 1 and the electrification unit 2. FIG.

  The manual wheelchair 1 includes a seat portion 16a, a frame 12 that fixes the seat portion 16a, and two manual-use wheels that are rotatably attached to the frame 12 on the same rotational axis P ′ across the seat portion 16a. Wheel 13. More specifically, the manual wheelchair 1 is a foldable manual wheelchair, and substantially symmetrical frames 12 are disposed on both the left and right sides. The frame 12 is formed by bending or welding a metal pipe or the like. The frame 12 includes a wheel support frame 12a that supports a manual wheel 13 so as to be rotatable about a wheel axis P, and a seat support frame 12b that supports a seat 16a. The wheel axis P is on the rotation axis P ′ that is the same virtual line. The frame 12 is further arranged substantially in parallel below the armrest support frame 12c extending upward from the rear end of the seat support frame 12b, the backrest support frame 12d supporting the backrest 16b, and the seat support frame 12b. And a lower frame 12e. The seat support frame 12b extends further forward and downward, supports the step 15 at its lower end, and the lower frame 12e supports the caster 14 at the front lower end. In FIG. 3, the wheel 13 on the front side of the drawing is omitted for the sake of explanation. Although omitted here, the manual wheel 13 is usually provided with a hand trim for moving and operating the wheelchair 1.

  The manual wheelchair 1 can move forward or backward in the straight traveling direction T when two wheels 13 having the same wheel diameter are rotated in the same direction at the same speed. Normally, the two wheels 13 of the manual vehicle including the manual wheelchair 1 have the same wheel diameter and do not turn with respect to the traveling direction at the wheel axis P, but by rotating the left and right wheels at different rotational speeds. The manual wheelchair 1 can be turned. The electric wheelchair 100 can realize the same operation as the case of the manual wheelchair 1 alone by mounting the electrification unit 2. When the wheelchair is another manual vehicle, it can have two wheels that have the same wheel diameter and do not turn in the wheel axis P with respect to the traveling direction.

  The electrification unit 2 includes a main body portion 27 attached to the frame 12 via a frame 220, a leg portion 23 that can rotate around the pivot axis R with respect to the main body portion 27, and a pivot axis R A drive wheel 21 having a drive shaft center Q arranged at a predetermined separation distance s and arranged to be rotatable around the drive shaft center Q with respect to the leg portion 23, and the drive wheel 21 on the leg portion 23. The first electric motor 25 that rotates relative to the main body 27, the second electric motor 32 that rotates the leg 23 relative to the main body 27, the operation unit 230 that operates the traveling of the electric wheelchair 100, and the operation of the operation unit 230 And a control unit 240 that drives the first electric motor 25 and the second electric motor 32 based on the signal output by.

  The frame 220 is formed in an L shape when viewed from the side, and is provided as a pair on the left and right sides of the electric wheelchair 100 as shown in FIG. 4 omits the configuration of the frame 12 and the like in order to explain the arrangement of the main configuration.

  A first electric motor 25 and a second electric motor 32 are disposed on the upper portion of the main body portion 27, and a leg portion 23 and driving wheels 21 are disposed on the lower portion of the main body portion 27. Although the arrangement of the first electric motor 25 and the second electric motor 32 is different from the omnidirectional movement mechanism described in FIGS. 1 and 2, the basic configuration is the same. The drive wheel 21 can be steered by rotating the leg portion 23 around the turning axis R by the second electric motor 32 by rotating the drive shaft 21 around the drive axis Q.

The operation unit 230 can be disposed at the tip of the armrest support frame 12c, and can be operated while the user is seated on the seat 16a. The operation unit 230 outputs a signal for determining the moving direction and moving speed of the electric wheelchair 100 according to the operation of the operator. The Y axis is the axis of rotation P ′ of the two manual wheels 13 of the wheelchair 100 as the Y axis, and the midpoint between the two wheels 13 on the Y axis (the midpoint of the tread of the wheel 13) is the origin O. X-axis perpendicular imaginary straight line (i.e. wheelchair 100 is a straight direction T of) when set to a the wheelchair coordinate system in a horizontal plane, X _a direction Y _a direction X-axis of the wheel chair coordinate system in the operation unit 230 And parallel to the Y axis. The operator, by operating on the example X _a direction of the operation unit 230 can be a command value of the linear velocity V of the electric wheelchair 100, X _a -Y _a rotation speed of the electric wheelchair 100 by the position operation in the coordinate system Ω Command value. When the manual wheelchair is another manual vehicle, the wheelchair coordinate system can be described as a manual vehicle coordinate system.

The operation unit 230 employs a track ball, a wheel, a joystick, or the like, which is a known means capable of outputting a signal serving as a command value for the straight traveling speed V and a command value for the turning speed Ω of the electric wheelchair 100 to the control unit 240. In particular, a joystick generally used for an electric wheelchair can be employed. The joystick can determine the moving direction and moving speed of the electric wheelchair according to the tilt direction and the tilt degree (angle) of the joystick by the user's operation. For example, the inclination in the longitudinal direction of the joystick (X _a direction in FIG. 4) may be a command value of the linear velocity V of the electric wheelchair 100, the inclination of the left and right directions of the joystick (Y _a direction in FIG. 4) is an electric wheelchair A command value of 100 turning speed Ω can be used.

As shown in FIG. 5, the control unit 240 includes a CPU (central processing unit) and the like, and inputs signals output from the operation unit 230 as a command value for the straight traveling speed V and a command value for the turning speed Ω of the electric wheelchair 100. And a calculation unit 244 for calculating a first angular velocity ω _{w at} the drive axis Q of the drive wheel 21 and a second angular velocity ω _s at the turning axis R of the leg 23 based on the following equation (1). And an output unit 246 that outputs the first angular velocity ω _w and the second angular velocity ω _s to the first electric motor 25 and the second electric motor 32.

  Here, r is the radius of the drive wheel 21, and s is the separation distance between the pivot axis R and the drive axis Q. More specifically, the separation distance s is the shortest distance between the imaginary plane including the drive axis Q and extending in the vertical direction from the ground plane and the pivot axis R. The rotation axis P 'of the two manual wheels 13 is the Y axis, the midpoint between the two wheels 13 on the Y axis is the origin O, and the virtual straight line perpendicular to the Y axis is the X axis. When the wheelchair coordinate system is set in a horizontal plane, φ is an angle formed by the traveling direction of the drive wheel 21 with respect to the X axis (the straight traveling direction T of the electric wheelchair 100) (described in FIG. 6), and x and y are in the wheelchair coordinate system. This is the position of the pivot axis R, and x is not zero.

A first angular velocity omega _w first electric motor 25 to drive the driving wheel 21 by a command value outputted from the control unit 240 rotates at a first angular velocity omega _w around the drive axis Q, and, The second electric motor 32 is driven by the command value of the second angular velocity ω _s output from the control unit 240, and the leg portion 23 is moved around the pivot axis R with respect to the main body portion 27 (that is, the wheelchair 100). Rotates at an angular velocity ω _s of 2. As a result, the wheelchair 100 can move at the straight speed V and the turning speed Ω intended by the operator.

  The control unit 240 can include a data storage unit (not shown). In the data storage unit, for example, the information of the above formula (1) is stored as predetermined drive control data for moving the electric wheelchair, and can be read at the request of the calculation unit 244. As the data storage unit, for example, a recording medium of a magnetic disk, a semiconductor storage memory, or the like can be used.

The control method of the electric wheelchair 100 is based on the first angular velocity ω _w in the drive shaft center Q and the turning axis based on the above equation (1) from the command value of the straight speed V and the turning speed Ω of the electric wheelchair 100. A second angular velocity ω _s at the center is calculated, the driving wheel 21 is rotated around the driving axis Q at the first angular velocity ω _w , and the driving wheel 21 is rotated around the turning axis R at the second angular velocity ω _s. Rotate to.

  In the present embodiment, the first electric motor 25 is used as an electric motor that rotates the driving wheel 21 around the driving axis Q, and the driving wheel 21 rotates around the turning axis R together with the leg portion 23. Although the second electric motor 32 is used as the motor, the omnidirectional moving mechanism as disclosed in Non-Patent Document 5 can be used, for example, without rotating and rotating the driving wheels as separate electric motors.

3. Second Embodiment FIG. 6 is a cross-sectional view schematically showing a part of an omnidirectional movement mechanism of an electric wheelchair according to a second embodiment. FIG. 7 is a schematic plan view schematically showing the electric wheelchair 100a according to the second embodiment.

  As shown in FIG. 7, the electric wheelchair 100a according to the second embodiment differs from the first embodiment in the arrangement of the drive wheels 21. The drive wheel 21 of the electric wheelchair 100 a is disposed in front of the rotational axis P ′ of the manual wheel 13 in the straight traveling direction T and close to the left wheel 13. That is, the rotation axis center line P ′ of the two manual wheels 13 is the Y axis, the midpoint between the two wheels 13 on the Y axis (tread) is the origin O, and a virtual straight line perpendicular to the Y axis is the X axis. When the wheelchair coordinate system is set in a horizontal plane, the position of the turning axis R of the drive wheel 21 can be expressed by coordinates (x, y). X is not 0. When x is 0, that is, when the turning axis R of the drive wheel and the rotational axis P ′ of the wheel 13 overlap, the wheel 13 does not move sideways, so the electric wheelchair 100a cannot move. It is assumed that it is not zero. In addition, about the structure which is common in the electric wheelchair 100 which concerns on 1st Embodiment, it demonstrates using the same code | symbol and the overlapping description is abbreviate | omitted.

  The electric wheelchair 100a according to the second embodiment can also be moved by controlling in the same manner as in the first embodiment.

  Here, the kinematic model of the electric wheelchair 100a will be described with reference to FIGS. 6 and 7, so that the electric wheelchair 100a can be turned in-situ like a conventional manual wheelchair according to the control law of the above formula (1). Explain that it is possible to achieve curving.

FIG. 6 is a conceptual diagram of the drive wheels 21 and the legs 23 of the electric wheelchair 100a shown in FIG. As described in the first embodiment, the drive wheel 21 can freely control the magnitude and direction of the translational speed by cooperatively controlling the speeds of the first electric motor and the second electric motor (not shown). . In FIG. 6, the X axis and the Y axis are wheelchair coordinate systems, V _x and V _y are speed components of the electrification unit 2 (active caster) in the turning axis R, and ω _w is the wheel axis in the drive axis Q. The first angular velocity that is the angular velocity, ω _s is the second angular velocity that is the angular velocity of the turning shaft R, r is the radius of the driving wheel 21, and s is the separation distance (the turning axis R from the ground contact position of the driving wheel 21). ) Is an angle formed by the direction of the driving wheel 21 (the straight traveling direction of the driving wheel 21) and the X axis. At this time, the relationship between the first angular velocity ω _w around the drive axis Q and the second angular velocity ω _s around the turning axis R and the speed generated in the turning axis R is expressed by the following equation (2). be able to.

  As shown in FIG. 7, in the electric wheelchair 100a, it is usually considered that the drive wheels are usually installed on the central axis of the wheelchair, but here, for generalization, any position (however, x is 0). Build a kinematic model when it is installed. The wheelchair coordinate system is set so that the midpoint between the left and right wheels 13 (tread) of the electric wheelchair 100a is the origin O, and the X axis is oriented in the straight traveling direction T of the electric wheelchair 100a.

At this time, V _x and V _y which are speed components in the X direction and Y direction generated by the electrification unit 2 (active casters) are the moving speed V in the straight traveling direction T (here, the X axis direction) of the electric wheelchair 100a and The rotation speed Ω around the coordinate system origin O is obtained as in the following formula (3).

  When the electric wheelchair 100a is operated using, for example, a joystick of the operation unit 230, the forward / backward inclination of the joystick is regarded as a command value for the straight traveling speed V, and the lateral inclination is regarded as a command value for the turning speed Ω. be able to. Therefore, the control law of the drive shaft center Q and the turning shaft center R of the electrification unit 2 (active caster) is obtained by the following equation (1) using the above equations (2) and (3).

Thus, it can be seen that the first angular velocity ω _w and the second angular velocity ω _s of the drive axis Q and the pivot axis R of the electrification unit 2 (active caster) can be uniquely determined by the movement of the electric wheelchair 100a. (However, x is not 0).

On the other hand, in the conventional manual wheelchair 1, the movement of the wheelchair (the straight traveling speed V and the turning speed Ω of the wheelchair) and the speed generated by the left and right wheels 13 (the straight traveling speed V _{l of} the left wheel and the straight traveling speed V _{r of the} right wheel) are: As shown in FIG. 13, the relationship can be expressed by the following formula (4).

  In this way, the speed generated by the left and right wheels 13 of the manual wheelchair 1 is also uniquely determined by the movement of the wheelchair 1, so that the same operation can be generated by the motorized unit 2 (active caster). I understand that. That is, in spite of propulsion with one drive wheel 21, regardless of the direction of the drive wheel 21, an in-situ turn of the electric wheelchair 100a or a curved traveling can be realized immediately.

  Therefore, in the electric wheelchair 100 according to the first embodiment and the electric wheelchair 100a according to the second embodiment, the input from the operation unit 230 is calculated by the above-described formula (1) in the control unit 240, thereby driving wheels 21. It can be seen that the movement intended by the operator is realized by rotating and / or turning.

4). Third Embodiment FIG. 8 is a schematic side view schematically showing an electric wheelchair 100b according to a third embodiment.

  The basic configuration is the same as that of the electric wheelchairs 100 and 100a according to the first and second embodiments, but the support structure of the electromotive unit 2 is different. The electric wheelchair 100b can directly fix the two frames 220b on which the main body 27 is placed on the lower frame 12e. By doing in this way, since the motorized unit 2 can be attached to the frame 12 without configuring the frame 220 in an L shape as in the first embodiment, the structure is simple and stable. Since the number of parts can be reduced, weight saving and cost saving can be realized.

5. Fourth Embodiment FIG. 9 is a schematic side view schematically showing an electric wheelchair 100c according to a fourth embodiment.

  The basic configuration is the same as that of the electric wheelchairs 100, 100a, and 100b according to the first to third embodiments, but the support structure of the electromotive unit 2 is different. The electric wheelchair 100c extends the seat support frame 12b rearward, further hangs and fixes four support columns 220c downward from the seat support frame 12b, and fixes the frame 220d to the lower ends of the four support columns 220c. The main body 27 can be fixed on the frame 220d. In this way, the electrification unit 2 can be securely attached to the frame 12.

  In the above-described embodiment, an example in which a manual wheelchair is used as a manual vehicle has been described. However, the present invention is not limited to this, and for example, a carriage used for carrying goods can be used. In that case, the manual vehicle has at least two wheels arranged on the same rotational axis. In the above-described embodiment, a so-called simple electric wheelchair in which a motorized unit is attached to a manual wheelchair as a manual vehicle has been described. It can be.

6). Fifth Embodiment An electric wheelchair 100e according to a fifth embodiment will be described with reference to FIGS.

  14 and 15 are schematic plan views schematically showing an electric wheelchair 100e according to the fifth embodiment. FIG. 16 is a schematic side view schematically showing an electric wheelchair according to the fifth embodiment. FIG. 17 is a rear view schematically showing an omnidirectional movement mechanism used in the electric wheelchair electrification unit according to the fifth embodiment. FIG. 18 is a diagram illustrating a simulation result of the turning operation of the electric wheelchair according to the fifth embodiment. FIG. 19 is a diagram illustrating a turning operation simulation result of the electric wheelchair according to the fifth embodiment.

  The electric wheelchair 100e according to the fifth embodiment shown in FIGS. 14 and 15 is the second described in FIGS. 7 and 13 in that the two casters 14 that are driven wheels are displayed in front of the electric wheelchair 100e. This is different from the electric wheelchair 100a according to the embodiment. However, the electric wheelchair 100a of FIGS. 7 and 13 is only described with the casters omitted, and the basic configuration of the five wheels is the same as that of the fifth embodiment. Although not shown in FIGS. 14 and 15, the electric wheelchair 100e according to the fifth embodiment includes a restraining mechanism that restrains the turning operation of the casters 14 that are two driven wheels, and a frame with respect to the main body. It is different from the electric wheelchair 100a according to the second embodiment in that it further includes an actuator that moves the wheel 13 for manual operation to a grounded state and a non-grounded state. The restraining mechanism and the actuator will be described later. Further, the description of the parts overlapping with those of the second embodiment is omitted.

  Here, first, the kinematic model of the electric wheelchair 100e will be described with reference to FIG. 14, so that the electric wheelchair 100e can be turned on the manual wheel 13 side according to the control law of the above formula (1). Next, it will be described that the turning operation on the caster 14 side can be realized.

In FIG. 14, the electric wheelchair 100e has two manual wheels 13 in a grounded state, which is exactly the same as in FIG. 7, and the drive wheel 21 of the motorized unit 2 (active caster) is expressed by the following equation (1). Based on this, the electric wheelchair 100e can be controlled. Specifically, the control method of the electric wheelchair 100e in FIG. 14 is based on the first value in the drive shaft center Q based on the following equation (1) from the command value of the straight traveling speed V and the command value of the turning speed Ω of the electric wheelchair 100e. and of calculating a second angular velocity omega _s of the angular velocity omega _w and swivel axis R, the drive wheel 21 rotates around the drive axis Q in the first angular velocity omega _w, the drive wheel 21 and the second angular velocity omega Rotate around the pivot axis R at _s .

  Here, r is the radius of the drive wheel 21, and s is the separation distance between the turning axis R and the driving axis Q. More specifically, s is the closest distance between the drive axis Q and the turning axis R in the horizontal plane including the drive axis Q. Further, the rotation axis center line P ′ of the two manual wheels 13 is the Y axis, the midpoint between the two manual wheels 13 on the Y axis is the origin O, and the virtual straight line perpendicular to the Y axis is the X axis. When the wheelchair coordinate system XY is set in the horizontal plane, φ is the angle formed by the traveling direction of the drive wheel 21 with respect to the X axis (straight direction of the electric wheelchair 100e), and x and y are turning in the wheelchair coordinate system XY. It is the position of the axis R, and x is not 0.

The turning center of the electric wheelchair 100e in the state of FIG. 14 is (x, y) in the wheelchair coordinate system XY.
= (0, 0), that is, at the position of the midpoint (origin O) between the two manual wheels 13. As described above, when the turning center is located on the rear wheel side of the electric wheelchair 100e, there is an advantageous characteristic that, in general, the vehicle is excellent in straight running performance, and particularly easy to operate when traveling at a high speed. However, on the other hand, when there is a turning center on the rear wheel side of the electric wheelchair 100e, it is disadvantageous in turning narrow corners and operations such as width adjustment.

  Therefore, in the present embodiment, the turning center of the electric wheelchair 100e is changed from the state of FIG. 14 to the state of FIG. Specifically, the rolling direction of the caster 14 is adjusted to the straight traveling direction T by a restraining mechanism (not shown), and the manual wheel 13 is floated by an actuator (not shown) to be in a non-grounded state. In FIG. 14, five wheels are installed, whereas in FIG. 15, the wheelchair is a three-wheel type in which only three wheels are installed. Since the caster 14 is restrained by the restraining mechanism, its own turning operation is restricted.

  The electric wheelchair 100e in FIG. 15 can also be controlled using the above formula (1), but in this case, the turning center of the electric wheelchair 100e is changed from the origin O to the origin O ′. Accordingly, it is necessary to change the wheelchair coordinate system XY to the wheelchair coordinate system X′-Y ′. Therefore, the control unit of the electric wheelchair 100e switches the above formula (1) to the following formula (5) for control. can do.

The origin O ′, which is the turning center of the electric wheelchair 100e, is the midpoint between the casters 14, and the control unit of the electric wheelchair 100e travels the signal output from the operation unit straight ahead of the electric wheelchair 100e at the midpoint between the casters 14. By inputting the command value for the speed V _{2 and} the command value for the turning speed Ω ₂ , the traveling direction of the electric wheelchair 100e can be changed based on the equation (5). Specifically, the control method of the electric wheelchair 100e in FIG. 15, the command value and the command value of the swing speed Omega ₂ of the linear velocity V ₂ of the electric wheelchair 100e, the drive axis Q based on the equation (5) The first angular velocity ω _w and the second angular velocity ω _s at the turning axis R are calculated, the driving wheel 21 is rotated around the driving axis Q at the first angular velocity ω _w , and the driving wheel 21 is moved to the second angular velocity ω _w . It rotates around the pivot axis R at an angular velocity ω _s .

14 is the same as the state of FIG. 14 in that r is the radius of the drive wheel 21 and s is the separation distance between the pivot axis R and the drive axis Q. Further, the rotation center line P2 of the _two casters 14 is the Y ′ axis, the midpoint between the two casters 14 on the Y ′ axis is the origin O ′, and the virtual straight line perpendicular to the Y ′ axis is the X ′ axis. When the second wheelchair coordinate system X′-Y ′ is set in the horizontal plane, φ ₂ is the angle formed by the traveling direction of the caster 14 with respect to the X ′ axis (straight direction T of the wheelchair), and x ₂ and y ₂ are the position of the pivot axis R of the wheel chair coordinate system X'-Y ', x ₂ is not zero.

  Therefore, the electric wheelchair 100e according to the fifth embodiment rotates and / or rotates the driving wheel 21 by calculating the input from the operation unit 230 in the control unit 240 using the above formula (1) or the above formula (5). The operation intended by the operator can be realized by turning.

Thus, by changing the turning center of the electric wheelchair 100e to the midpoint between the casters 14 in front of the wheelchair, the operability of the wheelchair is also greatly changed, and it is easy to perform operations such as turning a narrow corner or shifting the width. become. Therefore, the wheelchair user considers the usage environment and the like, and the center of the wheelchair is turned to the manual wheel 13 side as the rear wheel in accordance with the change in the usage environment such as indoors and outdoors by using one electric wheelchair 100e. And a control having a turning center on the caster 14 side which is the front wheel. That is, it is possible to provide a wheelchair drive system that can improve operability in various environments with a single wheelchair.

  As shown in FIG. 16, the electric wheelchair 100e according to the fifth embodiment omits the shape of a frame and the like, but the basic configuration of the electric wheelchair 100a according to the first embodiment is the same. Although the arrangement of the drive wheels 21 in FIGS. 16 to 19 is different from that in FIGS. 14 and 15, the control equations (1) and (5) can be used as they are. The electric wheelchair 100e includes a manual wheelchair 1e and a motorized unit 2e attached to the manual wheelchair 1e. The manual wheelchair 1e in the electric wheelchair 100e is attached to the frame 12 provided with a seat portion (not shown) and the wheel shaft center P on the same rotational axis P ′ to the frame 12 with the seat portion interposed therebetween. Two manual wheels 13 and two casters 14 rotatably mounted below a step 15 in front of the frame 12 are provided. Here, the description overlapping with the description of the first embodiment is omitted.

  The caster 14 is a driven wheel of the manual wheelchair 1, but the turning operation of the caster 14 is restrained by a restraining mechanism (not shown). As the restraining mechanism, a known mechanism can be adopted as long as the main body portion that rotatably holds the wheel portion of the caster 14 is fixed with respect to the frame 12 so as not to turn. For example, a lock pin may be provided in the frame 12 and engaged with a predetermined hole provided in the main body portion of the caster 14. The restraining mechanism can employ an electric method, a magnetic method, or a manual operation method. The direction of the caster 14, that is, the rolling direction of the wheels of the caster 14, is fixed in accordance with the straight traveling direction T of the electric wheelchair 100e. As is well known, when the caster 14 is operated in the straight direction T by operating the manual wheel 13, the caster 14 automatically turns and changes its direction to match the straight direction T. In this way, it is only necessary to restrain the caster 14 by the restraining mechanism when the rolling direction of the caster 14 matches the straight traveling direction T.

  FIG. 17 is a rear view of the electrification unit 2e as seen from the rear of the electric wheelchair 100e, but the spur gear 41 is shown in cross section for the sake of explanation. The electrification unit 2e is rotatable around the pivot axis R with respect to the main body 27 and the main body 27 attached to the frame 12 via a frame 220 as shown in FIG. And a drive shaft center Q disposed at a predetermined separation distance s with respect to the pivot axis R, and is disposed so as to be rotatable around the drive axis Q with respect to the leg portion 23. Drive wheel 21. As shown in FIG. 17, the electrification unit 2 e includes a first electric motor 25 that rotates the driving wheel 21 relative to the leg portion 23 via the spur gears 40, 41, 42 and the bevel gears 43, 44, And a second electric motor 32 that rotates the leg portion 23 with respect to the main body portion 27 via gears 29 and 31.

  The actuator 50 can move the frame 12 relative to the main body 27 of the electrification unit 2e to change the manual wheel 13 between a grounded state and a non-grounded state. That is, by driving the actuator 50, the frame 12 can be raised until the manual wheel 13 is separated from the ground surface, and the three-wheel type can be changed to the ground by only the two casters 14 and the driving wheels 21 of the front wheels. At this time, the caster 14 is restrained by the restraining mechanism, and the driving wheel 21 of the electrification unit 2e performs the turning operation and the retreating operation of the electric wheelchair 100e. The lower end of the actuator 50 can be fixed to the rear upper surface of the main body 27 of the electrification unit 2e, and the tip of the rod portion 52 of the actuator 50 can be fixed to the rear of the backrest portion of the frame 12, for example. By driving the actuator 50, the rod portion 52 moves forward and backward with respect to the actuator 50, and the distance between the main body portion 27 and the frame 12 can be changed.

  Therefore, the electric wheelchair 100e is attached to the rear of the frame 12 with two driven wheels (the casters 14 in the present embodiment) attached to the front of the frame 12, a restraining mechanism for restricting the turning operation of the driven wheels. The two manual wheels 13, the drive wheel 21 that can turn and move the electric wheelchair 100 by the electric motors 25 and 32, and the actuator 50 that moves the frame 12 up and down with respect to the drive wheel 21. It is also a novel feature that the manual wheel 13 can be changed between a grounded state and a non-grounded state by the actuator 50. In particular, the electric wheelchair 100e has one driving wheel 21 that performs forward / backward movement and turning operation, and four driven wheels that do not have a driving mechanism, and is an actuator 50 that can move up and down at least two driven wheels. It is a novel feature that it is possible to change between a five-wheel grounding state and a three-wheel grounding state. By adopting such a configuration, an electric wheelchair that is advantageous for indoor movement with a small turn like a front wheel drive type electric wheelchair in a three-wheel grounding state, and a rear wheel drive type electric wheelchair in a five-wheel grounding state. An electric wheelchair that is advantageous for outdoor movement with stable high-speed and long-distance movement can have a special effect that it can be freely switched by one wheelchair.

  Further, the actuator 50 of the electric wheelchair 100e can also retract the caster 14 by contracting the rod portion 52 from the five-wheel grounding state, and in this case, the three-wheel grounding state in which the manual wheel 13 and the driving wheel 21 are installed. Can be changed. Thus, when the caster 14 is in a non-grounded state, for example, when a relatively large step is climbed over with the electric wheelchair 100e, the caster 14 can be easily climbed on the step, and even if there is a step, the caster 14 can be operated relatively easily. Can do.

  As the actuator 50, a known drive mechanism can be used. For example, it can be a direct drive type drive mechanism. In addition to an electric mechanism such as a linear motor or a ball screw mechanism, a hydraulic mechanism, a pneumatic mechanism, or a manual mechanism can be used. A mechanism or the like can be employed. A suspension mechanism can also be employed between the frame 12 and the motorized unit 2e.

  FIGS. 18 and 19 are diagrams showing simulation results of the turning operation when the electric wheelchair 100e according to the fifth embodiment is made into three wheels by floating the manual wheel 13 in a non-grounded state. It has been found that the electric wheelchair 100e can perform a turning operation around the origin O 'at the midpoint between the casters 14 as the front wheels. Similarly, in an actual electric wheelchair, when the turning operation was performed in a state where the manual wheels were lifted, the turning operation could be performed around the midpoint between the casters as the front wheels.

In the electric wheelchair of the first embodiment to the fifth embodiment, there is no turning axis R of the drive wheel 21 on the rotation axis P of the manual wheel 13 (in Formula (1) or Formula (5), x or x ₂ is not zero.) Therefore, it is possible to obtain an excellent attitude stability of the electric wheelchair in particular during acceleration. Specifically, for example, in a conventional rear wheel drive type simple electric wheelchair, when accelerating with a large acceleration, it is considered that the state of the wheelchair floats on the wheelchair frame, In the electric wheelchair of the first embodiment to the fifth embodiment, it is difficult to cause such an operation. That is, in the electric wheelchair 100e of FIG. 14, since the manual wheel 13 is behind the driving wheel 21, the driving wheel 21 is also lifted when the front wheel 14 is lifted during acceleration. Can be prevented. Further, as shown in FIGS. 3, 4, 8, and 16, in the electric wheelchairs 100, 100b, 100c, 100e in which the turning axis R of the drive wheel 21 is behind the rotation axis P of the manual wheel 13, The drive wheel 21 can prevent the front wheel 14 from being lifted. Therefore, the electric wheelchairs according to the first to fifth embodiments can obtain excellent posture stability during acceleration, and agile operation is also possible by obtaining high acceleration performance.

  FIG. 10 is a photograph showing the appearance of the electric wheelchair prototype 100d according to the first embodiment.

  A prototype 100d of the electric wheelchair 100 according to the first embodiment was prototyped and a running experiment was performed.

  The manual wheelchair 1 is based on “NEO” manufactured by OX Engineering, and the motorized unit 2 (active caster) is mounted behind the manual wheelchair 1 so that the drive wheels 21 are arranged on the X-axis. A prototype 100d was created. As for the mounting position of the electrification unit 2 in the prototype 100d, the pivot axis R is (x, y) = (− 0.3, 0) [m].

  The operation unit is operated by a joystick, and the command value of the straight speed V of the joystick and the command value of the turning speed Ω are taken in as a voltage value to a personal computer as a control unit, and a first servo motor is formed according to the direction of the drive wheel. An electric motor and a second electric motor were controlled. An absolute encoder is used to detect the direction of the drive wheel, and operations such as initialization are not required.

In the running experiment, the motorized unit 2 was controlled so as to execute the basic operations for straight running and on-the-spot turning, and it was verified whether the required wheelchair operation could be realized. In the straight traveling, a command to perform straight traveling at a constant speed was given, and in the in-situ turning operation, a command to turn at a constant angular velocity was given, and in each case, the motion of the prototype 100d was measured. The rotational movement of the left and right wheels 13 of the manual wheelchair 1 was measured with a potentiometer. Further, in order to know the state of the electrification unit 2 in each run, the first angular velocity ω _w (angular velocity at the drive wheel shaft) and the second angular velocity ω _s (angular velocity at the turning shaft angle) of the electrification unit 2 are encoded. It was measured by.

(1) Straight running test FIG. 11 shows the results of a straight running test of the electric wheelchair prototype 100d according to the first embodiment. Here, the angle φ (steering angle of the active caster) formed by the traveling direction of the driving wheel with respect to the X axis (the straight traveling direction of the wheelchair) in the wheelchair coordinate system, the displacement X and the posture angle θ of the prototype 100d in the straight traveling direction are shown. It was.

  In the initial state, the steering angle φ is approximately 180 °, that is, backward. From this state, it can be confirmed that the operation immediately forward of the wheelchair is started and the direction of the driving wheel is turned over in the course of the straight traveling operation and is operating in the traveling direction. Even during the turning over of the caster, only the displacement x in the straight direction increased linearly, and it was found that good straight movement could be realized.

(2) Turning motion test FIG. 12 shows the results of the turning motion test of the electric wheelchair prototype 100d according to the first embodiment.

  A turning motion test was performed under the same test conditions as the straight running test of (1). Even in this case, initial conditions were set such that the caster flipping operation occurred during the turning operation. Although the wheelchair posture angle θ has greatly changed, the displacement X in the straight-ahead direction is maintained at almost 0, and it has been confirmed that a favorable turning operation has been realized.

1, 1e Manual wheelchair, 2 Motorized unit, 12 frame, 12a Wheel support frame, 12b Seat support frame, 12c Armrest support frame, 12d Back support frame, 12e Lower frame, 13 wheels, 14 casters, 16a Seat, 16b Backrest part, 21 Drive wheel, 22 Axle, 23 Leg part, 24 Reducer, 25 First electric motor, 26 Encoder, 27 Body part, 28 Bearing, 29 Gear, 31 Gear, 32 Second electric motor, 34 Encoder, 40, 41, 42, 43, 44 Gear, 100, 100a, 100b, 100c, 100d, 100e Electric wheelchair, 220, 220b, 220c, 220d Frame, 230 operation unit, 240 control unit, 242 input unit, 244 calculation Part, 246 output part, O, O 'origin, P wheel axis, P' rotation Cord, Q drive axis, R swivel axis, r the distance, s radius, phi is the angle of the driving wheel with respect to the X-axis, omega _w first angular velocity, omega _s second angular velocity, V rectilinear velocity, Omega turning speed

Claims (6)

A body portion attachable to a manual vehicle having at least two wheels arranged on the same rotational axis;
A leg portion rotatably attached to the main body portion around a pivot axis;
A drive wheel having a drive shaft disposed at a predetermined distance from the pivot shaft, and being rotatably attached to the leg portion around the drive shaft;
A first electric motor that rotates the drive wheel relative to the leg;
A second electric motor that rotates the leg with respect to the main body;
An operation unit for operating the traveling of the manual vehicle;
A control unit that drives the first electric motor and the second electric motor based on a signal output by an operation of the operation unit;
Have
When the motorized unit is attached to the manual vehicle, the control unit inputs a signal output from the operation unit as a command value for the straight traveling speed V and a command value for the turning speed Ω of the manual vehicle. Based on (1), a first angular velocity ω _{w at} the drive axis of the drive wheel and a second angular velocity ω _s at the pivot axis of the leg are calculated, and the first angular velocity ω _w is output. and by driving the first electric motor, the second by outputting the angular velocity omega _s and drives the second electric motor, motorized units for manual vehicle.
(Where r is the radius of the drive wheel and s is the separation distance. The rotation axis of the two wheels is the Y axis, and the midpoint between the two wheels on the Y axis is the origin. When a manual vehicle coordinate system having an imaginary straight line perpendicular to the Y axis as the X axis is set in the horizontal plane, φ is an angle formed by the traveling direction of the drive wheel with respect to the X axis (straight direction of the manual vehicle), x , Y is the position of the turning axis in the manual vehicle coordinate system, and x is not 0.) An electrification unit that moves by rotating the drive wheel around a drive axis by an electric motor and changes the direction of movement of the drive wheel by rotating the drive wheel around a turning axis by an electric motor Is attached to a manual vehicle having at least two wheels arranged on the same rotational axis.
From the command value of the straight speed V of the manual vehicle and the command value of the turning speed Ω, the first angular speed ω _w in the drive axis and the second angular speed ω _s in the turning axis based on the following equation (1). To calculate
Rotating said drive wheel about the drive axis in the first angular velocity omega _w,
A method for controlling a motorized unit of a manual vehicle, characterized in that the drive wheel is rotated around the turning axis at the second angular velocity ω _s .
(Where r is the radius of the drive wheel, s is the separation distance between the pivot axis and the drive axis. Also, the rotation axis of the two wheels is the Y axis, and 2 on the Y axis. When a manual vehicle coordinate system with the midpoint between the two wheels as the origin and an imaginary straight line perpendicular to the Y axis as the X axis is set in the horizontal plane, φ is the drive with respect to the X axis (straight direction of the manual vehicle) (An angle formed by the traveling direction of the wheel, x, y is the position of the turning axis in the manual vehicle coordinate system, and x is not 0.) A seat,
A frame for fixing the seat;
Two manual wheels mounted on the frame so as to be rotatable on the same axis of rotation with the seat interposed therebetween;
A main body attached to the frame;
A leg that is rotatable about a pivot axis relative to the body;
A drive wheel having a drive shaft disposed at a predetermined separation distance with respect to the pivot shaft, and disposed so as to be rotatable around the drive shaft with respect to the leg portion;
A first electric motor that rotates the drive wheel relative to the leg;
A second electric motor that rotates the leg with respect to the main body;
An operation unit for operating the vehicle;
A control unit that drives the first electric motor and the second electric motor based on a signal output by an operation of the operation unit;
An electric wheelchair having
The control unit inputs the signal output from the operation unit as a command value for the straight traveling speed V and a command value for the turning speed Ω of the electric wheelchair, and based on the following formula (1), the drive shaft of the drive wheel The first angular velocity ω _{w at the} center and the second angular velocity ω _s at the pivot axis of the leg are calculated, the first angular velocity ω _w is output to drive the first electric motor, and rotating the drive wheel, and changes the traveling direction of the electric wheelchair by outputting the second angular velocity omega _s driving said second electric motor, electric wheelchair.
(Where r is the radius of the drive wheel and s is the separation distance. Also, the rotation axis of the two manual wheels is the Y axis, and the two manual wheels on the Y axis are When the wheelchair coordinate system is set in the horizontal plane with the midpoint between them as the origin and the imaginary straight line perpendicular to the Y-axis as the X-axis, φ is the direction of travel of the drive wheel with respect to the X-axis (The angle formed, x, y is the position of the pivot axis in the wheelchair coordinate system, and x is not 0.) In claim 3,
Two driven wheels supported by the frame;
A restraining mechanism for restraining the turning motion of the driven wheel;
An actuator for moving the frame relative to the main body and changing the manual wheel between a grounded state and a non-grounded state;
Further comprising
Directing the driven wheel in the straight direction of the electric wheelchair, and in a state where the two driven wheels are positioned on the same rotational axis, the restraint mechanism is driven to restrain the turning operation of the driven wheel,
The actuator is driven to change the turning center of the electric wheelchair from the midpoint between the manual wheels to the midpoint between the driven wheels by setting the manual wheel to an ungrounded state, and the control unit includes: The signal output from the operation unit is input as a command value for the straight traveling speed V _{2 and} a command value for the turning speed Ω ₂ of the electric wheelchair at the midpoint between the driven wheels, and the formula (1) is expressed by the following formula (5 ), And the traveling direction of the electric wheelchair is changed based on the following formula (5).
(Where r is the radius of the driving wheel and s is the separation distance. Also, the rotation axis of the two driven wheels is the Y ₂ axis, and the _two driven wheels on the Y ₂ axis are when the second wheelchair coordinate system perpendicular imaginary straight line to the Y ₂ -axis and the X ₂ axis midpoint as the origin is set to the horizontal plane, the phi ₂ the slave with respect to the X ₂ axis (straight direction of the wheelchair) (An angle formed by the moving direction of the driving wheel, x ₂ , y ₂ is the position of the pivot axis in the wheelchair coordinate system, and x ₂ is not 0.) Rotating the drive wheel around the drive axis by the electric motor and moving the drive wheel around the turning axis by the electric motor to change the moving direction of the drive wheel A method for controlling an electric wheelchair having two manual wheels on an axis,
From the command value of the straight speed V of the electric wheelchair and the command value of the turning speed Ω, the first angular velocity ω _w in the drive shaft center and the second angular speed ω _s in the turning shaft center based on the following equation (1). To calculate
Rotating said drive wheel about the drive axis in the first angular velocity omega _w,
A method for controlling an electric wheelchair, wherein the driving wheel is rotated around the turning axis at the second angular velocity ω _s .
(Where r is the radius of the drive wheel, s is the distance between the pivot axis and the drive axis, and the Y axis is the rotational axis of the two manual wheels. When a wheelchair coordinate system is set in the horizontal plane with the midpoint between the above two manual wheels as the origin and an imaginary straight line perpendicular to the Y axis as the X axis, φ is the X axis (the straight direction of the wheelchair ), X and y are the positions of the pivot axis in the wheelchair coordinate system, and x is not 0.) In claim 5,
The electric wheelchair further includes two driven wheels, a restraining mechanism that restrains the turning motion of the driven wheel, and an actuator that changes the manual wheel between a grounded state and a non-grounded state,
Directing the driven wheel in the straight direction of the electric wheelchair, and in a state where the two driven wheels are positioned on the same rotational axis, the restraint mechanism is driven to restrain the turning operation of the driven wheel,
The actuator is driven to change the turning center of the electric wheelchair from the midpoint between the manual wheels to the midpoint between the driven wheels while the manual wheels are ungrounded, and between the driven wheels. from the command value and the command value of the swing speed Omega ₂ of the linear velocity V ₂ of the electric wheelchair at the midpoint, and changes the traveling direction of the electric wheelchair in accordance with the following equation (5), an electric wheelchair.
(Where r is the radius of the driving wheel and s is the separation distance. Also, the rotation axis of the two driven wheels is the Y ₂ axis, and the _two driven wheels on the Y ₂ axis are when the second wheelchair coordinate system perpendicular imaginary straight line to the Y ₂ -axis and the X ₂ axis midpoint as the origin is set to the horizontal plane, the phi ₂ the slave with respect to the X ₂ axis (straight direction of the wheelchair) (An angle formed by the moving direction of the driving wheel, x ₂ , y ₂ is the position of the pivot axis in the wheelchair coordinate system, and x ₂ is not 0.)