Motor control system, drive unit and electric vehicle

Abstract

To improve convenience for a user who operates an electrically driven vehicle.SOLUTION: A motor control system 100 used for an electrically driven vehicle 1 comprises: an accelerator lever 51 operated by a user; a control unit 110 for controlling operations of electric motors 25L, 25R for generating drive force for making the electrically driven vehicle 1 travel, the control unit 110 performing control for increasing rotation speeds of the electric motors 25L, 25R, according to increase of a first rotation angle θ1 being a rotation angle of a first rotation direction D1 of the accelerator lever 51 from a reference position of the lever 51; and a first torsion spring 70 having a coil part 73 through which a rotation shaft 52 of the accelerator lever 51 passes, the first torsion spring applying first elastic force in a second rotation direction D2 opposite to the first rotation direction D1 to the accelerator lever 51. The control unit 110 performs control for stopping the electric motors 25L, 25R when detecting that the first rotation angle θ1 becomes equal to or greater than a first prescribed rotation angle θb.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a motor control system, a drive unit, and an electric vehicle. [Background technology]

[0002] Electric wheelchairs are known as one type of electric vehicle that uses an electric motor as a drive source. The rotation of the electric motor is transmitted to the wheels, enabling the electric wheelchair to move. Some electric wheelchairs use an electric motor to assist the force exerted by the user on the hand rims.

[0003] Patent Document 1 discloses an electric wheelchair in which a switch for turning the electric motor on and off is provided on a handle that is held by the caregiver. The caregiver can turn the switch on to rotate the electric motor, causing the electric wheelchair to move. The caregiver can turn the switch off to stop the electric motor, causing the electric wheelchair to stop. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 10-165452 Summary of the Invention [Problem to be solved by the invention]

[0005] There is a demand for further improvements in convenience for users who operate electric vehicles such as electric wheelchairs. [Means for solving the problem]

[0006] A motor control system according to one embodiment of the present invention is a motor control system used in an electric vehicle, and includes an accelerator lever operated by a user, a housing that rotatably supports the accelerator lever, an angle sensor that outputs a signal corresponding to the rotation angle of the accelerator lever, and a control device that controls the operation of an electric motor that generates driving force to run the electric vehicle, the control device controlling the electric motor to increase the rotation speed in accordance with an increase in a first rotation angle, which is the rotation angle of the accelerator lever in a first rotation direction from a reference position of the accelerator lever, and a first torsion spring having a coil portion through which the rotation axis of the accelerator lever passes and that applies a first elastic force to the accelerator lever in a second rotation direction that is opposite to the first rotation direction, and when the control device detects that the first rotation angle has become equal to or greater than a first predetermined rotation angle, the control device controls the electric motor to stop.

[0007] According to one embodiment of the present invention, when the first rotation angle of the accelerator lever reaches or exceeds a first predetermined rotation angle, the electric motor is stopped. The user can stop the electric motor by simply increasing the amount of operation of the accelerator lever. This allows the electric vehicle to stop traveling without having to return the accelerator lever to a reference position (e.g., neutral position), improving user convenience.

[0008] A first torsion spring is used as the elastic member that generates a force in the direction that returns the accelerator lever to its reference position. By passing the rotation shaft of the accelerator lever through the inside of the coil part of the first torsion spring, the first torsion spring and the rotation shaft can share the same space, which reduces the space required for arranging the elastic member. This allows for greater freedom in arranging other components in the motor control system and also makes it possible to make the motor control system more compact.

[0009] In one embodiment, the motor control system further includes a second torsion spring having a coil portion through which the rotation axis of the accelerator lever passes and applying a second elastic force in the second rotation direction to the accelerator lever, wherein when the second predetermined rotation angle is set to a predetermined value that is greater than 0 degrees and smaller than the first predetermined rotation angle, the second torsion spring does not apply the second elastic force to the accelerator lever when the first rotation angle is smaller than the second predetermined rotation angle, and applies the second elastic force to the accelerator lever when the first rotation angle is equal to or greater than the second predetermined rotation angle.

[0010] When the first rotation angle of the accelerator lever becomes equal to or greater than the second predetermined rotation angle, the second torsion spring applies a second elastic force to the accelerator lever, thereby rapidly increasing the amount of force required for the user to move the accelerator lever. This prevents the first rotation angle from becoming equal to or greater than the first predetermined rotation angle against the user's intention, causing the electric motor to stop.

[0011] The first predetermined rotation angle at which the electric motor is stopped is greater than the second predetermined rotation angle at which the second torsion spring begins to apply the second elastic force to the accelerator lever. By not stopping the electric motor at the second predetermined rotation angle, it is possible to prevent the electric motor from stopping against the user's intention.

[0012] As described above, when the first rotation angle of the accelerator lever reaches or exceeds the second predetermined rotation angle, the amount of force required for the user to move the accelerator lever increases rapidly. This allows the user to recognize that the accelerator lever is approaching an operating position at which the electric motor will stop. If the user does not want to stop the electric vehicle, the user can continue driving the electric vehicle by not moving the accelerator lever further in the first rotation direction. If the user wants to stop the electric vehicle, the user can stop the electric motor by moving the accelerator lever further in the first rotation direction.

[0013] A second torsion spring is used as an elastic member that applies a second elastic force to the accelerator lever when the first rotation angle reaches or exceeds a second predetermined rotation angle. By passing the accelerator lever's rotation shaft through the coil portion of the second torsion spring, the second torsion spring and the rotation shaft can share the same space, reducing the space required for arranging the elastic member. This allows for greater freedom in arranging other components in the motor control system and enables the motor control system to be made more compact.

[0014] In one embodiment, the spring constant of the second torsion spring may be greater than the spring constant of the first torsion spring.

[0015] The second elastic force that the second torsion spring applies to the accelerator lever can be increased, and the first rotation angle can be prevented from becoming equal to or greater than the first predetermined rotation angle against the user's will, thereby preventing the electric motor from stopping.

[0016] For example, by increasing the wire diameter of the wire material that makes up the second torsion spring or by using harder wire material, it is possible to increase the spring constant of the second torsion spring while keeping the size of the second torsion spring small.

[0017] In one embodiment, the second torsion spring has a first arm portion and a second arm portion extending from the coil portion of the second torsion spring, and the motor control system includes a support member provided on the rotation axis of the accelerator lever and supporting the first arm portion so that the first arm portion moves in conjunction with the rotation of the accelerator lever, and a stopper that limits the range of movement of the second arm portion in conjunction with the rotation of the accelerator lever, wherein the stopper does not contact the second arm portion when the first rotation angle is smaller than the second predetermined rotation angle, and contacts the second arm portion when the first rotation angle is equal to or greater than the second predetermined rotation angle, thereby restricting the movement of the second arm portion in conjunction with the rotation of the accelerator lever.

[0018] When the first rotation angle of the accelerator lever becomes equal to or greater than the second predetermined rotation angle, the second torsion spring can apply a second elastic force to the accelerator lever.

[0019] In one embodiment, the support member may support the first arm portion and the second arm portion in a state in which the second torsion spring is twisted in advance by a predetermined amount in a direction in which the second torsion spring twists in response to rotation of the accelerator lever in the first rotational direction.

[0020] By twisting the second torsion spring a predetermined amount in advance, a large elastic force can be applied to the accelerator lever from the stage when the second torsion spring starts to apply the second elastic force to the accelerator lever, thereby enabling a more rapid increase in the amount of force required for the user to move the accelerator lever.

[0021] In one embodiment, the magnitude of the torque required to cause the first rotation angle to exceed the second predetermined rotation angle may be between 10 and 12 times the magnitude of the torque required to make the first rotation angle the second predetermined rotation angle.

[0022] By suddenly increasing the magnitude of the torque required for the first rotation angle to exceed the second predetermined rotation angle, it is possible to prevent the electric motor from stopping against the user's intention.

[0023] In one embodiment, the motor control system may further include a fastening structure that suppresses misalignment of the accelerator lever in a rotational direction between the rotation shaft of the accelerator lever and the support member.

[0024] This suppresses misalignment between the rotation axis of the accelerator lever and the second torsion spring supported by the support member, and makes it possible to maintain a constant magnitude of the first rotation angle at which the second torsion spring begins to apply the second elastic force to the accelerator lever.

[0025] In one embodiment, the second torsion spring is a double torsion spring, and the double torsion spring has two of the coil portions lined up along a first direction, and the double torsion spring has two arm portions extending from both ends of the double torsion spring in the first direction as one of the first arm portion and the second arm portion, and the other arm portion of the first arm portion and the second arm portion is located between the two coil portions in the first direction and connects the two coil portions.

[0026] By using a double torsion spring with two coil portions as the second torsion spring, the second elastic force applied to the accelerator lever can be increased. Because the stress acting on the second torsion spring can be distributed across the two coil portions, the durability of the second torsion spring can be increased even when the second elastic force is large.

[0027] In one embodiment, the first predetermined rotation angle may be 2 to 5 degrees greater than the second predetermined rotation angle.

[0028] The electric motor is stopped when the first rotation angle reaches a first predetermined rotation angle that is slightly larger than the second predetermined rotation angle at which the second torsion spring begins to apply the second elastic force to the accelerator lever. By not stopping the electric motor when the first rotation angle reaches the second predetermined rotation angle, it is possible to prevent the electric motor from stopping against the user's intention.

[0029] In one embodiment, the second predetermined rotation angle may be equal to or greater than 20 degrees and equal to or less than 30 degrees.

[0030] The accelerator lever can be rotated within an angle range that allows the user to easily adjust the traveling speed of the electric vehicle.

[0031] In one embodiment, the motor control system further includes a magnet that moves in conjunction with the rotation of the accelerator lever, and the angle sensor is a magnetic sensor that is supported on the housing so as not to move in conjunction with the rotation of the accelerator lever.

[0032] The use of a magnetic sensor allows the rotation angle of the accelerator lever to be detected with high accuracy, and the use of a non-contact magnetic sensor increases the durability of the angle sensor.

[0033] By arranging the angle sensor, from which the electric wire extends, so that it does not move in conjunction with the rotation of the accelerator lever, the durability of the angle sensor can be increased.

[0034] In one embodiment, a base portion of the accelerator lever may be connected to both ends of the rotary shaft.

[0035] The first torsion spring and the second torsion spring can be disposed in an area surrounded by the base of the accelerator lever.

[0036] When the accelerator lever is rotated, the base of the accelerator lever comes into contact with the housing, thereby determining the neutral position of the accelerator lever.

[0037] In one embodiment, the housing may be provided with a hole that allows a handlebar of the electric vehicle to pass through the housing.

[0038] When a motor control system is retrofitted to an electric vehicle, the grip position originally intended for the electric vehicle can be maintained, and the user can operate the accelerator lever while holding the grip.

[0039] A drive unit according to one embodiment of the present invention includes the motor control system and an electric motor that generates a driving force for running the electric vehicle.

[0040] By installing the drive unit in an electric vehicle, convenience for the user can be improved.

[0041] An electric vehicle according to one embodiment of the present invention includes the drive unit.

[0042] This makes it possible to realize an electric vehicle that is highly convenient for the user.

[0043] In one embodiment, the electric vehicle may be an electric wheelchair.

[0044] This makes it possible to realize an electric wheelchair that is highly convenient for caregivers. [Effects of the Invention]

[0045] According to one embodiment of the present invention, when the first rotation angle of the accelerator lever reaches or exceeds a first predetermined rotation angle, the electric motor is stopped. The user can stop the electric motor by simply increasing the amount of operation of the accelerator lever. This allows the electric vehicle to stop traveling without having to return the accelerator lever to a reference position (e.g., neutral position), improving user convenience.

[0046] A first torsion spring is used as the elastic member that generates a force in the direction that returns the accelerator lever to its reference position. By passing the rotation shaft of the accelerator lever through the inside of the coil part of the first torsion spring, the first torsion spring and the rotation shaft can share the same space, which reduces the space required for arranging the elastic member. This allows for greater freedom in arranging other components in the motor control system and also makes it possible to make the motor control system more compact. [Brief explanation of the drawings]

[0047] [Figure 1] 1 is a right side view showing an electric wheelchair 1 according to an embodiment. [Figure 2] 1 is a perspective view showing an electric wheelchair 1 according to an embodiment. [Figure 3]1 is a block diagram showing a drive unit 10 provided in an electric wheelchair 1 according to an embodiment. [Figure 4] FIG. 1 is a perspective view showing an operating device 50 according to an embodiment. [Figure 5] 1 is a block diagram showing a hardware configuration of an operation device 50 according to an embodiment. [Figure 6] FIG. 2 is a perspective view showing a part of the inside of an operating device 50 according to the embodiment. [Figure 7] FIG. 2 is an exploded perspective view showing a plurality of components included in the operating device 50 according to the embodiment. [Figure 8] 1 is a perspective view showing an operating device 50 when an accelerator lever 51 according to an embodiment is in a neutral position. [Figure 9] 1 is a perspective view showing an operating device 50 when a first rotation angle θ1 of an accelerator lever 51 according to an embodiment is a predetermined rotation angle θa. [Figure 10] 1 is a perspective view showing an operating device 50 according to an embodiment when a first rotation angle θ1 is larger than a predetermined rotation angle θa. [Figure 11] 10 is a diagram showing a second torsion spring 80 and a stopper 58 when the first rotation angle θ1 of the accelerator lever 51 according to the embodiment is 0 degrees. FIG. [Figure 12] 10 is a diagram showing a second torsion spring 80 and a stopper 58 when a first rotation angle θ1 of an accelerator lever 51 according to the embodiment is a predetermined rotation angle θa. FIG. [Figure 13] 10 is a diagram showing a second torsion spring 80 and a stopper 58 when a first rotation angle θ1 according to the embodiment is larger than a predetermined rotation angle θa. FIG. [Figure 14] 10 is a diagram showing the relationship between a first rotation angle θ1 of an accelerator lever 51 according to an embodiment and a force F1 required for an assistant to move the accelerator lever 51 in a first rotation direction D1. FIG. [Figure 15] 10 is a diagram showing the relationship between the first rotation angle θ1 and the force F1 when the second torsion spring 80 according to the embodiment is not twisted in advance. FIG. [Figure 16] FIG. 2 is a diagram showing a part of the inside of an operating device 50 according to the embodiment. [Figure 17] FIG. 2 is a diagram showing a part of the inside of a case 230 seen from above according to the embodiment. [Figure 18] 1 is a block diagram showing a hardware configuration of an operation device 50 according to an embodiment. [Figure 19] 10 is a diagram illustrating control of electric motors 25L and 25R using angle sensor 91 and angle sensor 291 according to an embodiment. FIG. [Figure 20] FIG. 10 is a diagram showing a state in which the detection value 301 is equal to or greater than V(min) when the first rotation angle θ1 is 0 degrees in the operating device 50 according to the embodiment. [Figure 21] 10 is a diagram showing a control for preventing the electric motors 25L and 25R from rotating when the detection value 302 of the second angle sensor 291 according to the embodiment indicates "0." [Figure 22] 10 is a diagram showing a state in which the detection value 302 of the second angle sensor 291 according to the embodiment always indicates "1." [Figure 23] 10 is a diagram showing another example of control of the electric motors 25L and 25R using the angle sensor 91 and the angle sensor 291 according to the embodiment. FIG. [Figure 24] 10 is a diagram showing a control for preventing the electric motors 25L and 25R from rotating when the detection value 302 of the second angle sensor 291 according to the embodiment indicates "0." [Figure 25] FIG. 10 is a diagram showing control in which a detection value 301 is set to V(min) when the first rotation angle θ1 is 0 degrees according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0048] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Similar components will be assigned similar reference numerals, and redundant descriptions will be omitted. In the description of the embodiments, the terms front, rear, top, bottom, left, and right respectively refer to the front, rear, top, bottom, left, and right as seen from the perspective of a passenger seated in a seat of an electric vehicle. The following embodiments are merely examples, and the present invention is not limited to the following embodiments.

[0049] An example of an electric vehicle according to the embodiments is an electric wheelchair. The electric vehicle is not limited to an electric wheelchair, and may be any vehicle that travels using an electric motor as a drive source. For example, the electric vehicle may be a PLEV (Personal Light Electric Vehicle). For example, the electric vehicle may be an electric kick scooter. An electric kick scooter may also be called an "e-scooter" or electric kick scooter. An electric vehicle according to the embodiments may be, for example, a low-speed electric vehicle whose maximum speed is limited to a relatively low speed. The maximum speed is limited to, for example, 20 km / h or less. For example, the maximum speed of an electric wheelchair may be limited to 6 km / h. The maximum speed values ​​are merely examples, and the embodiments of the present invention are not limited thereto. In the following description of the embodiments, an electric wheelchair is used as an example of an electric vehicle.

[0050] (Electric wheelchair) Fig. 1 is a right side view showing an electric wheelchair 1 according to an embodiment, and Fig. 2 is a perspective view showing the electric wheelchair 1 as seen from diagonally rear left.

[0051] The electric wheelchair 1 includes a body frame 4 formed of metal pipes or the like. A pair of left and right wheels 2L and 2R and a pair of left and right casters 5L and 5R are rotatably supported on the body frame 4. The body frame 4 includes a pair of left and right seat frames 41, a pair of left and right armrest frames 42, a pair of left and right base frames 43, a pair of left and right under frames 44, and a pair of left and right back frames 45.

[0052] A seat 6 on which a person sits is provided between a pair of left and right seat frames 41. The front portion of the seat frame 41 is bent downward, and a footrest 47 is provided at the lower end of the front portion of the seat frame 41. The rear end of the seat frame 41 is connected to a back frame 45. The back frame 45 extends in the vertical direction. A backrest 9 is provided between the pair of left and right back frames 45. In Figure 1, the backrest 9 is not shown in order to clearly show the shape of the back frame 45.

[0053] The back frame 45 has a handle bar 45a that bends and extends rearward at its upper portion. The handle bar 45a is provided with hand grips 46 that the caregiver can hold with their hands.

[0054] A base frame 43 and an underframe 44 are disposed below the seat frame 41. An armrest frame 42 is disposed above the seat frame 41. An armrest 8 is provided on the armrest frame 42, on which a person seated in the seat 6 places their arms.

[0055] The wheel 2L is provided with a hand rim 3L for manually driving the wheel 2L. The wheel 2R is provided with a hand rim 3R for manually driving the wheel 2R. Each of the wheels 2L and 2R has a wheel hub 21, an outer periphery 23 surrounding the wheel hub 21, and a plurality of spokes 22. The plurality of spokes 22 connect the wheel hub 21 and the outer periphery 23. The outer periphery 23 includes a rim to which the spokes 22 are connected, and a tire attached to the rim. The hand rims 3L and 3R are connected to a plurality of connecting members 24 extending from the outer periphery 23 of the wheels 2L and 2R.

[0056] An electric motor 25L is provided on the wheel hub 21 of the wheel 2L. An electric motor 25R is provided on the wheel hub 21 of the wheel 2R. The electric motors 25L and 25R are, for example, hub motors. The wheel hub 21 includes an axle, a first housing located on the inside in the left-right direction of the electric wheelchair 1, and a second housing located on the outside. The first housing on the inside is fixed to the axle, and the second housing on the outside is rotatable about the axle. The stators of the electric motors 25L and 25R are fixed to the first housing and the axle, and the rotors of the electric motors 25L and 25R are fixed to the second housing. The spokes 22 are connected to the second housing.

[0057] The axle of the wheel hub 21 is fixed to the body frame 4. The axle of the wheel hub 21 is fixed to, for example, the back frame 45. The axle of the wheel hub 21 may be fixed to the body frame 4 via a bracket provided between the seat frame 41 and the underframe 44. The wheels 2L and 2R rotate as the second housing rotates relative to the axle and the first housing fixed to the body frame 4.

[0058] The electric wheelchair 1 is equipped with a battery 7 for supplying power to the electric motors 25L and 25R. When power is supplied to the electric motors 25L and 25R, a rotor fixed to the second housing rotates relative to a stator fixed to the first housing, causing the wheels 2L and 2R to rotate.

[0059] The electric motors 25L and 25R are not limited to hub motors, and may be provided outside the wheel hub 21. In this case, the rotation generated by the electric motors 25L and 25R can be transmitted to the wheel hub 21 via a reducer.

[0060] An operating device 15 is provided in front of the armrest 8 to allow a person seated in the seat 6 to operate the electric wheelchair 1. The operating device 15 has a stick 16, and when the stick 16 of the operating device 15 is tilted by hand, the electric motors 25L and 25R generate rotation, causing the electric wheelchair 1 to travel. The traveling speed can be adjusted by adjusting the degree to which the stick 16 is tilted. When the stick 16 is returned to the neutral position, the electric motors 25L and 25R stop, and the electric wheelchair 1 can be stopped.

[0061] An operating device 50 is provided on one of the handlebars 45a of the pair of left and right back frames 45, allowing the attendant to operate the electric wheelchair 1. The operating device 50 has an accelerator lever 51 that can rotate around a rotation axis 52. When the attendant grips the accelerator lever 51 together with the handgrip 46, the accelerator lever 51 rotates around the rotation axis 52. In response to this operation by the attendant, the electric motors 25L and 25R generate rotation, causing the electric wheelchair 1 to travel. The traveling speed can be adjusted by adjusting the degree to which the accelerator lever 51 is gripped, i.e., by adjusting the magnitude of the rotation angle of the accelerator lever 51. Returning the accelerator lever 51 to the neutral position stops the electric motors 25L and 25R, and the electric wheelchair 1 can be stopped.

[0062] (Drive unit) Next, the drive unit provided in the electric wheelchair 1 will be described.

[0063] 3 is a block diagram showing the drive unit 10 provided in the electric wheelchair 1. The battery 7 (FIG. 2) supplies power to the drive unit 10. The drive unit 10 causes the electric motors 25L and 25R to generate drive forces corresponding to the operations on the operating devices 15 and 50.

[0064] The drive unit 10 includes a motor control system 100, electric motors 25L and 25R, speed sensors 26L and 26R, and wheels 2L and 2R. The motor control system 100 includes a control device 110 and operation devices 15 and 50.

[0065] The control device 110 includes a processor 111, recording media such as a read-only memory (ROM) 112 and a random access memory (RAM) 113, and drive circuits 114L and 114R. The ROM 112 stores a computer program (or firmware) for causing the processor 111 to execute processing. The computer program may be provided to the drive unit 10 via a storage medium (e.g., a semiconductor memory) or a telecommunications line (e.g., the Internet). Such a computer program may be sold as commercial software.

[0066] The processor 111 is a semiconductor integrated circuit and includes, for example, a central processing unit (CPU). The processor 111 can be realized by a microprocessor or a microcontroller. The processor 111 sequentially executes a computer program (a computer program stored in the ROM 112) that describes a group of instructions for executing various processes, thereby realizing desired processing.

[0067] The processor 111 may be a field programmable gate array (FPGA) equipped with a CPU, a graphics processing unit (GPU), an application specific integrated circuit (ASIC), an application specific standard product (ASSP), or a combination of two or more circuits selected from these circuits.

[0068] ROM 112 is, for example, a writable memory (e.g., PROM), a rewritable memory (e.g., flash memory), or a read-only memory. ROM 112 does not have to be a single recording medium, but may be a collection of multiple recording media. RAM 113 provides a working area for temporarily loading computer programs stored in ROM 112 at boot time. RAM 113 does not have to be a single recording medium, but may be a collection of multiple recording media.

[0069] The drive circuits 114L and 114R are, for example, inverters. The drive circuits 114L and 114R generate drive currents according to the current command values ​​output from the processor 111 and supply the drive currents to the electric motors 25L and 25R.

[0070] The electric motor 25L is provided with a speed sensor 26L. The electric motor 25R is provided with a speed sensor 26R. The speed sensors 26L and 25R are, for example, encoders. The speed sensor 26L detects the rotation angle of the rotor of the electric motor 25L and outputs a signal corresponding to the rotation angle to the control device 110. The speed sensor 26R detects the rotation angle of the rotor of the electric motor 25R and outputs a signal corresponding to the rotation angle to the control device 110.

[0071] The control device 110 may be provided in the wheel hub 21 of the wheel 2L or the wheel 2R. The components of the control device 110 may be distributed between the wheel hub 21 of the wheel 2L and the wheel hub 21 of the wheel 2R. For example, the drive circuit 114L may be provided in the wheel hub 21 of the wheel 2L, and the drive circuit 114R may be provided in the wheel hub 21 of the wheel 2R. The control device 110 may be provided independently of the wheel hub 21.

[0072] The processor 111 of the control device 110 calculates the rotation speeds of the electric motors 25L and 25R from the output signals of the speed sensors 26L and 26R. The tire sizes of the wheels 2L and 2R are known in advance, and the processor 111 can calculate the traveling speed of the electric wheelchair 1 from the rotation speeds of the electric motors 25L and 25R. If the rotation of the electric motors 25L and 25R is transmitted to the wheels 2L and 2R via reducers, the processor 111 also calculates the traveling speed of the electric wheelchair 1 using information on the reduction ratio of the reducers.

[0073] The speed sensors 26L and 26R may be provided on the wheel hubs 21, outer peripheries 23, or spokes 22 of the wheels 2L and 2R. The speed sensors 26L and 26R may output signals corresponding to the rotation of the parts on which they are provided.

[0074] The operation device 15 outputs a signal to the control device 110 in response to the operation of the stick 16 by the person seated in the seat 6. The operation device 50 outputs a signal to the control device 110 in response to the operation of the accelerator lever 51 by the caregiver.

[0075] The processor 111 calculates the target values ​​of the rotation speeds of the electric motors 25L and 25R based on the output signal from the operation device 15 or the operation device 50. The processor 111 calculates the target values ​​of the rotation speeds by, for example, referring to a map that shows the relationship between the operation amount of the stick 16 of the operation device 15 and the accelerator lever 51 of the operation device 50 and the rotation speeds of the electric motors 25L and 25R.

[0076] The processor 111 calculates the current rotation speeds of the electric motors 25L and 25R from the output signals of the speed sensors 26L and 26R, and calculates a current command value to reduce the deviation between the current rotation speed and a target value.

[0077] The processor 111 outputs the calculated current command value to the drive circuits 114L and 114R. The drive circuits 114L and 114R generate drive currents according to the current command values ​​and supply them to the electric motors 25L and 25R. The electric motors 25L and 25R rotate when the drive current is supplied. Feedback control is performed to reduce the deviation between the current rotation speed of the electric motors 25L and 25R and the target value, thereby allowing the electric wheelchair 1 to travel at a speed according to the amount of operation of the operation device 15 or 50. The drive unit 10 may be detachable from the body frame 4 of the electric wheelchair 1. The drive unit 10 may also be detachable from a body frame other than the body frame 4. For example, by removing the wheels from the body frame of a typical wheelchair and attaching the drive unit 10 to the body frame, the typical wheelchair can be used as the electric wheelchair 1.

[0078] The drive unit 10 may not have wheels 2L and 2R, in which case the drive unit 10 is attached to a wheelchair that has wheels and hand rims.

[0079] The motor control system 100 does not necessarily have to include the operating device 15. In this case, the electric motors 25L and 25R are driven by operating the operating device 50 by an assistant.

[0080] (operating device) Next, the operation device 50 will be described in detail.

[0081] 4 is a perspective view showing the operating device 50 as seen from diagonally rear left. The operating device 50 includes an accelerator lever 51 operated by an assistant, and a housing 53 that rotatably supports the accelerator lever 51. A base portion 51a of the accelerator lever 51 is attached to a rotary shaft 52. The housing 53 rotatably supports the rotary shaft 52, thereby rotatably supporting the accelerator lever 51. The housing 53 is provided with a display panel 61, a power switch 62, a mode selection switch 63, an operation switch 64, a forward / reverse switch 67, and an alarm component 65.

[0082] 5 is a block diagram showing the hardware configuration of the operation device 50. The operation device 50 further includes a control device 120 and an angle sensor 91.

[0083] The control device 120 includes a processor 121, a ROM 122, and a RAM 123. The explanation of the processor 121, the ROM 122, and the RAM 123 overlaps with the explanation of the processor 111, the ROM 112, and the RAM 113 of the control device 110, and therefore will be omitted here. The processor 121 controls the operation of the operation device 50. The angle sensor 91 outputs a signal according to the rotation angle of the accelerator lever 51.

[0084] The housing 53 has a first housing 53a and a second housing 53b. The first housing 53a and the second housing 53b are fitted together to form a space for accommodating various components. The first housing 53a and the second housing 53b can be fixed to each other using, for example, fasteners such as bolts or adhesive. The control device 120 can send and receive signals to and from the control device 110 and the like via an electric wire 66 extending from the first housing 53a to the outside.

[0085] The power switch 62 is a switch for turning the power of the electric wheelchair 1 on and off. When the power of the electric wheelchair 1 is on, the drive unit 10 operates, and when the power is off, the drive unit 10 does not operate. When the power is off, if the caregiver operates the power switch 62, the power is turned on, and when the power is on, if the caregiver operates the power switch 62, the power is turned off.

[0086] The mode selection switch 63 is a switch for selecting a desired driving mode from a plurality of driving modes that have different maximum speeds for the electric wheelchair 1. When the caregiver operates the mode selection switch 63, the processor 121 transmits a signal corresponding to the operation to the control device 110. The processor 111 of the control device 110 sets the driving mode according to the received signal. The caregiver can select the desired driving mode by operating the mode selection switch 63.

[0087] The forward / reverse selector switch 67 is a switch for switching between forward and reverse movement of the electric wheelchair 1. When the caregiver operates the forward / reverse selector switch 67 to select forward or reverse movement, the processor 121 sends a signal indicating forward or reverse movement to the control device 110. When the processor 111 receives a signal indicating forward movement, it controls the electric motors 25L and 25R so that the electric wheelchair 1 moves forward. When the processor 111 receives a signal indicating reverse movement, it controls the electric motors 25L and 25R so that the electric wheelchair 1 moves backward.

[0088] The display panel 61 displays various information in response to the operation of the operating device 50 by the caregiver. The display panel 61 is, for example, a liquid crystal panel. The processor 121 causes the display panel 61 to display information such as the remaining battery capacity, the distance that can be traveled, the selected travel mode, and whether or not there is an abnormality in the electric wheelchair 1. The display panel 61 may be a display panel other than a liquid crystal panel, for example, an OLED (Organic Light-Emitting Diode) panel or an electronic paper panel. The caregiver can change the display content of the display panel 61 by operating the operation switch 64.

[0089] When there is information that should be notified to the caregiver, the processor 121 uses the notification component 65 to notify the caregiver. The notification component 65 is, for example, a sound-emitting component that emits sound and / or a light-emitting lamp. The sound-emitting component is, for example, a buzzer or a speaker, but is not limited to these. The processor 121 activates the notification component 65, for example, when the remaining capacity of the battery 7 is low or an abnormality occurs in the electric wheelchair 1. When the notification component 65 emits sound or emits light, the caregiver can easily recognize that the remaining capacity of the battery 7 is low or that an abnormality has occurred. Furthermore, the processor 121 displays information that should be notified to the caregiver on the display panel 61. In this case, the display panel 61 may emit light or flash the displayed content to emphasize the display.

[0090] The housing 53 is provided with holes 54 through which the handlebars 45a pass. The holes 54 are provided at the front and rear of the housing 53, allowing the handlebars 45a to pass through the housing 53. For ease of understanding, the handgrip 46 is not shown in FIG. 4. In this embodiment, the handlebars 45a pass through the operation device 50, and the operation device 50 is attached to the handlebars 45a. This allows the position of the handgrip 46 originally intended for the wheelchair to be maintained when the operation device 50 is retrofitted to a wheelchair. The caregiver can operate the accelerator lever 51 while holding the handgrip 46, which is maintained in a position suitable for operating the wheelchair.

[0091] Next, a description will be given of a mechanism related to the rotational movement of the accelerator lever 51. Fig. 6 is a perspective view showing part of the interior of the operating device 50 as seen from diagonally front left. Fig. 7 is an exploded perspective view showing multiple components provided in the operating device 50.

[0092] Holes 256 and 257 through which the rotary shaft 52 of the accelerator lever 51 passes are provided on the left and right walls of the first housing 53a. A hole 51b through which the rotary shaft 52 passes is provided in the base portion 51a of the accelerator lever 51, and the left end of the base portion 51a and the left end of the rotary shaft 52 are fixed to each other by fitting the head portion 252 of the rotary shaft 52 into the hole 51b. The right end of the base portion 51a of the accelerator lever 51 and the right end of the rotary shaft 52 can be fixed to each other using a fastener such as a bolt or a nut.

[0093] The operating device 50 includes a first torsion spring 70, a second torsion spring 80, and support members 210 and 220.

[0094] The first torsion spring 70 has a coil portion 73 and arm portions 71 and 72 extending from the coil portion 73. The second torsion spring 80 has a coil portion 83 and arm portions 81 and 82 extending from the coil portion 73.

[0095] In this embodiment, the second torsion spring 80 is a double torsion spring. The second torsion spring 80, which is a double torsion spring, has two coil portions 83 lined up in the left-right direction. Two arm portions 81 extend from both ends of the second torsion spring 80 in the left-right direction. The arm portion 82 is located between the two coil portions 83 in the left-right direction and connects the two coil portions 83.

[0096] The support member 210 supports the arm portion 71 of the first torsion spring 70 and one of the two arm portions 81 of the second torsion spring 80. The support member 210 has a cylindrical portion 211 through which the rotation shaft 52 passes. The cylindrical portion 211 passes through the inside of the coil portion 73 of the first torsion spring 70 and the inside of one of the two coil portions 83 of the second torsion spring 80. The support member 210 further includes a cylindrical portion 212 that covers the outer periphery of the coil portion 73, and a cylindrical portion 213 that covers the outer periphery of one of the two coil portions 83. The cylindrical portions 212 and 213 have a drum-like shape, and their side walls are connected to the outer periphery of the cylindrical portion 211.

[0097] The cylindrical portion 212 is provided with a notch 215. The arm portion 71 of the first torsion spring 70 fits into the notch 215, whereby the arm portion 71 is supported by the support member 210.

[0098] A hole 217 is formed in the cylindrical portion 213. One of the two arm portions 81 passes through the hole 217 and comes into contact with the inner wall of the hole 217, whereby the arm portion 81 is supported by the support member 210.

[0099] The support member 220 supports the other of the two arm portions 81 of the second torsion spring 80. The support member 220 has a cylindrical portion 221 through which the rotation shaft 52 passes. The cylindrical portion 221 passes through the inside of the other of the two coil portions 83 of the second torsion spring 80. The support member 220 further includes a cylindrical portion 222 that covers the outer periphery of the other of the two coil portions 83. The cylindrical portion 222 has a drum-like shape, and its side wall is connected to the outer periphery of the cylindrical portion 221.

[0100] A hole 227 is formed in the cylindrical portion 222. The other of the two arm portions 81 passes through the hole 227 and comes into contact with the inner wall of the hole 227, whereby the arm portion 81 is supported by the support member 220.

[0101] A notch 216 is provided in the cylindrical portion 213, and a notch 225 is provided in the cylindrical portion 222. The arm portion 82 of the second torsion spring 80 fits into the notch portions 216 and 225, whereby the arm portion 82 is supported by the support members 210 and 220.

[0102] The rotating shaft 52 and the support members 210 and 220 have a fastening structure that suppresses misalignment in the rotational direction of the accelerator lever 51. As an example, the body portion 251 of the rotating shaft 52 has a flat portion 254 (the portion shown hatched in FIG. 7) that has a flat shape. The inner circumferential wall portions of the cylindrical portions 211 and 221 have flat portions 214 and 224 that have flat shapes and contact the flat portion 254. The body portion 251 having the flat portion 254 fits into the inner circumferential wall portion having the flat portions 214 and 224, thereby suppressing misalignment between the rotating shaft 52 and the support members 210 and 220. Note that a key groove or the like may be used to suppress misalignment between the rotating shaft 52 and the support members 210 and 220.

[0103] Root portion 51a of accelerator lever 51 is connected to both ends of rotary shaft 52. For example, root portion 51a has a U-shape, with the left end of the U-shape connected to the left end of rotary shaft 52 and the right end of the U-shape connected to the right end of rotary shaft 52. By attaching accelerator lever 51 to rotary shaft 52 so that root portion 51a is connected to both ends of rotary shaft 52, it is possible to arrange first torsion spring 70, second torsion spring 80, and support members 210 and 220 in the area surrounded by root portion 51a in the left-right direction.

[0104] The first housing 53a is provided with an angle sensor 91 that outputs a signal corresponding to the rotation angle of the accelerator lever 51. The angle sensor 91 is, for example, a magnetic sensor. In the example shown, the angle sensor 91 is provided on a board 93 arranged in the first housing 53a. A cover 94 may be provided on the board 93. A magnet 92, which is a permanent magnet, is provided on the support member 210. The position of the magnet 92 provided on the support member 210 moves in conjunction with the rotation of the accelerator lever 51. The angle sensor 91, which is a magnetic sensor, is provided on the first housing 53a so as not to move in conjunction with the rotation of the accelerator lever 51. As the accelerator lever 51 rotates, the magnet 92 moves relative to the angle sensor 91, and the magnetic field applied to the angle sensor 91 changes, thereby making it possible to detect the rotation angle of the accelerator lever 51.

[0105] By using a magnetic sensor as the angle sensor 91, it is possible to accurately detect the rotation angle of the accelerator lever 51. By using a non-contact magnetic sensor, it is possible to increase the durability of the angle sensor 91. Furthermore, by arranging the angle sensor 91, from which an electric wire extends, so that it does not move in conjunction with the rotation of the accelerator lever 51, it is possible to increase the durability of the angle sensor 91.

[0106] The processor 121 of the control device 120 calculates the rotation angle of the accelerator lever 51 using the output signal of the angle sensor 91, and outputs information about the rotation angle to the control device 110. The calculation of the rotation angle of the accelerator lever 51 using the output signal of the angle sensor 91 may be performed by the processor 111 of the control device 110.

[0107] The position of the arm portion 72 of the first torsion spring 70 supported by the support member 210 moves in conjunction with the rotation of the accelerator lever 51. The first housing 53a is provided with a stopper 57 that comes into contact with the arm portion 72 of the first torsion spring 70 to restrict the movement of the arm portion 72. The stopper 57 may be part of the first housing 53a.

[0108] 6 shows the operating device 50 when the accelerator lever 51 is in the neutral position. When the caregiver grips the accelerator lever 51 with their hand, the accelerator lever 51 rotates in a first rotation direction D1. The first rotation direction D1 is a counterclockwise direction in a side view of the operating device 50 seen from the left.

[0109] The processor 111 of the control device 110 performs control to increase the rotational speed of the electric motors 25L and 25R in response to an increase in the first rotation angle θ1 of the accelerator lever 51. The first rotation angle θ1 is the rotation angle of the accelerator lever 51 in a first rotation direction D1 from a reference position. The reference position of the accelerator lever 51 is, for example, the neutral position.

[0110] The first torsion spring 70 applies a first elastic force in a second rotational direction D2, which is opposite to the first rotational direction D1, to the accelerator lever 51. When the caregiver stops operating the accelerator lever 51, the first elastic force of the first torsion spring 70 causes the accelerator lever 51 to rotate in the second rotational direction D2 and return to the neutral position. At the neutral position where the first rotational angle θ1 is 0 degrees, the processor 111 controls the electric motors 25L and 25R to stop.

[0111] The first torsion spring 70 applies a first elastic force in the second rotation direction D2 to the accelerator lever 51 throughout the entire angular range in which the accelerator lever 51 can rotate. Even in the neutral position, the first torsion spring 70 applies the first elastic force to the accelerator lever 51. This keeps the accelerator lever 51 in the neutral position when it is not being operated by an assistant.

[0112] When the accelerator lever 51 is at the neutral position, the front end of the base portion 51a contacts the rear portion of the first housing 53a, which prevents the accelerator lever 51 from rotating further in the second rotation direction D2 from the neutral position, and the first elastic force of the first torsion spring 70 maintains the accelerator lever 51 in the neutral position.

[0113] The positions of the arms 81 and 82 of the second torsion spring 80 supported by the support members 210 and 222 move in conjunction with the rotation of the accelerator lever 51. The first housing 53a is provided with a stopper 58 that limits the range of movement of the arm 82 in conjunction with the rotation of the accelerator lever 51. The stopper 58 may be part of the first housing 53a.

[0114] The first rotation angle θ1 of the accelerator lever 51 is equal to the predetermined rotation angle θ a When the first rotation angle θ1 is smaller than the second predetermined rotation angle θ, the stopper 58 does not come into contact with the arm portion 82 and does not restrict the movement of the arm portion 82. a When the rotation angle reaches or exceeds this value, the stopper 58 comes into contact with the arm portion 82, and restricts the movement of the arm portion 82 in conjunction with the rotation of the accelerator lever 51. a is an angle greater than 0 degrees, for example, but not limited to, 20 degrees or more and 30 degrees or less.

[0115] The first rotation angle θ1 is the predetermined rotation angle θ a In this state, the movement of the arm portion 82 is restricted by the stopper 58. As a result, the second torsion spring 80 rotates in such a manner that the first rotation angle θ1 is equal to the predetermined rotation angle θ a In this state, the second elastic force in the second rotation direction D2 can be applied to the accelerator lever 51. The second torsion spring 80 rotates the accelerator lever 51 in such a manner that the first rotation angle θ1 is equal to or smaller than the predetermined rotation angle θ a When the first rotation angle θ1 is smaller than the predetermined rotation angle θ a When this occurs, the second torsion spring 80 applies a second elastic force to the accelerator lever 51, thereby increasing the amount of force required for the caregiver to move the accelerator lever 51.

[0116] 8 and 9 are perspective views showing part of the interior of the operating device 50 as seen from diagonally forward left. FIG. 8 shows the operating device 50 when the accelerator lever 51 is in the neutral position. The first rotation angle θ1 in the neutral position is 0 degrees. FIG. 9 shows the operating device 50 when the first rotation angle θ1 of the accelerator lever 51 is 0 degrees. a10 shows the operating device 50 when the first rotation angle θ1 is equal to the predetermined rotation angle θ a 1 shows the operating device 50 when it is larger than .

[0117] 11 to 13 are diagrams showing the second torsion spring 80 and the stopper 58 as viewed from the left side. FIG. 11 shows the second torsion spring 80 and the stopper 58 when the first rotation angle θ1 of the accelerator lever 51 is 0 degrees. FIG. 12 shows the second torsion spring 80 and the stopper 58 when the first rotation angle θ1 is equal to the predetermined rotation angle θ a 13 shows the second torsion spring 80 and the stopper 58 when the first rotation angle θ1 is equal to the predetermined rotation angle θ a 10 shows the second torsion spring 80 and the stopper 58 when the force is greater than .

[0118] FIG. 14 is a diagram showing the relationship between the first rotation angle θ1 of the accelerator lever 51 and the magnitude of the force required by the assistant to move the accelerator lever 51 in the first rotation direction D1. The horizontal axis of the graph shown in FIG. 14 represents the first rotation angle θ1 of the accelerator lever 51. The vertical axis represents the force F1 required by the assistant to move the accelerator lever 51 in the first rotation direction D1. The solid line in the graph represents the force F1 required by the assistant to move the accelerator lever 51 in the first rotation direction D1. The dashed lines in the graph represent the rotation speeds of the electric motors 25L and 25R. In the example shown in FIG. 14, the movable range of the accelerator lever 51 is from 0 degrees to 30 degrees. As an example, the predetermined rotation angle θ a is set to 25 degrees.

[0119] When the caregiver operates the accelerator lever 51 in the neutral position, the accelerator lever 51 rotates in a first rotation direction D1. The processor 111 performs control to increase the rotation speed of the electric motors 25L and 25R in accordance with an increase in the first rotation angle θ1 of the accelerator lever 51. When the travel speed of the electric wheelchair 1 is to be reduced, the caregiver loosens their grip on the accelerator lever 51, thereby reducing the first rotation angle θ1 and reducing the rotation speed of the electric motors 25L and 25R.

[0120] 14, when the first rotation angle θ1 is between 0 and 2 degrees, the processor 111 does not rotate the electric motors 25L and 25R. This prevents the electric motors 25L and 25R from starting when the accelerator lever 51 is rotated slightly against the caregiver's intention.

[0121] As shown in FIGS. 9 and 12, the first rotation angle θ1 is set to the predetermined rotation angle θ a When the first rotation angle θ1 reaches the predetermined rotation angle θ a When this occurs, the second torsion spring 80 applies a second elastic force to the accelerator lever 51. When the first rotation angle θ1 is equal to or greater than the predetermined rotation angle θ a In the above case, both the first elastic force of the first torsion spring 70 and the second elastic force of the second torsion spring 80 are applied to the accelerator lever 51, so the magnitude of the force F1 required for the caregiver to move the accelerator lever 51 increases rapidly.

[0122] In this embodiment, the processor 111 determines whether the first rotation angle θ1 is greater than the predetermined rotation angle θ b When it is detected that the rotation angle θ has reached or exceeded the predetermined rotation angle θ (first predetermined rotation angle), the electric motors 25L and 25R are stopped. b is the predetermined rotation angle θ a The predetermined rotation angle θ is larger than the predetermined rotation angle θ. b is, for example, a predetermined rotation angle θ a In the example shown in FIG. 14, the predetermined rotation angle θ a The processor 111 determines whether the first rotation angle θ1 is equal to or smaller than the predetermined rotation angle θ b In the above cases, control is performed to stop the electric motors 25L and 25R.

[0123] This allows the caregiver to stop the electric motors 25L and 25R simply by increasing the amount of operation of the accelerator lever 51. The electric wheelchair 1 can be stopped without returning the accelerator lever 51 to the neutral position, improving convenience for the caregiver.

[0124] The first rotation angle θ1 of the accelerator lever 51 is equal to the predetermined rotation angle θ a When this occurs, the second torsion spring 80 applies a second elastic force to the accelerator lever 51, which causes the magnitude of the force required for the caregiver to move the accelerator lever 51 to suddenly increase. This causes the first rotation angle θ1 to suddenly increase beyond the predetermined rotation angle θ b As a result, the electric motors 25L and 25R can be prevented from stopping.

[0125] The predetermined rotation angle θ at which the electric motors 25L and 25R are stopped b is the predetermined rotation angle θ at which the second torsion spring 80 begins to apply the second elastic force to the accelerator lever 51. a The predetermined rotation angle θ a By not stopping the electric motors 25L and 25R in this state, it is possible to prevent the electric motors 25L and 25R from stopping against the intention of the caregiver.

[0126] As described above, the first rotation angle θ1 of the accelerator lever 51 is set to the predetermined rotation angle θ a Once this occurs, the amount of force required for the caregiver to move the accelerator lever 51 increases rapidly. This enables the caregiver to recognize that the accelerator lever 51 is approaching the operating position where the electric motors 25L and 25R will stop. If the caregiver does not want to stop the electric wheelchair 1, the caregiver can continue moving the electric wheelchair 1 by not moving the accelerator lever 51 any further in the first rotation direction D1. If the caregiver wants to stop the electric wheelchair 1, the caregiver can stop the electric motors 25L and 25R by moving the accelerator lever 51 any further in the first rotation direction D1.

[0127] In this embodiment, a first torsion spring 70 is used as an elastic member that generates a force in a direction that returns the accelerator lever 51 to the neutral position. By passing the rotation shaft 52 of the accelerator lever 51 through the inside of the coil portion 73 of the first torsion spring 70, the first torsion spring 70 and the rotation shaft 52 can share the same space, and the space required for arranging the elastic member can be reduced. In addition, when the first rotation angle θ1 is equal to the predetermined rotation angle θ a As a result, second torsion spring 80 is used as an elastic member that applies a second elastic force to accelerator lever 51. By passing rotation shaft 52 of accelerator lever 51 through the inside of coil portion 83 of second torsion spring 80, second torsion spring 80 and rotation shaft 52 can share the same space, and the space required for arranging the elastic member can be reduced. This increases the degree of freedom in arranging other components included in motor control system 100 and enables motor control system 100 to be made more compact.

[0128] The spring constant of the second torsion spring 80 may be greater than the spring constant of the first torsion spring 70. This allows the second elastic force that the second torsion spring 80 applies to the accelerator lever 51 to be increased, and the first rotation angle θ1 may be increased to the predetermined rotation angle θ1 against the intention of the caregiver. b As a result, it is possible to prevent electric motors 25L and 25R from stopping. For example, by increasing the wire diameter of the wire material constituting second torsion spring 80 or by using harder wire material, it is possible to increase the spring constant of second torsion spring 80 while keeping the size of second torsion spring 80 small.

[0129] By using a double torsion spring having two coil portions 83 as the second torsion spring 80, it is possible to increase the second elastic force applied to the accelerator lever 51. Because the stress acting on the second torsion spring 80 can be distributed to the two coil portions 83, it is possible to increase the durability of the second torsion spring 80 even when the second elastic force is large.

[0130] The second torsion spring 80 may be a single torsion spring. When the second torsion spring 80 is a single torsion spring, a plurality of second torsion springs 80 may be provided.

[0131] 6 and 7, the arm portion 81 and the arm portion 82 of the second torsion spring 80 are supported by the support members 210 and 220. The support members 210 and 220 support the arm portion 81 and the arm portion 82 in a state in which the second torsion spring 80 is twisted in advance by a predetermined amount in a direction in which the second torsion spring 80 twists in response to rotation of the accelerator lever 51 in the first rotational direction D1. For example, the second torsion spring 80 is twisted in advance by a predetermined amount in a direction in which the coil portion 83 of the second torsion spring 80 is wound up.

[0132] In a side view, the angle formed between arm portion 81 and arm portion 82 is defined as θ2. The angle θ2 when accelerator lever 51 is in the neutral position (FIG. 11) is smaller than the angle θ2 when the load applied to second torsion spring 80 is zero.

[0133] By twisting the second torsion spring 80 by a predetermined amount in advance, a large elastic force can be applied to the accelerator lever 51 from the stage when the second torsion spring 80 starts to apply the second elastic force to the accelerator lever 51. This allows the magnitude of the force required for the caregiver to move the accelerator lever 51 to increase more rapidly.

[0134] For example, the first rotation angle θ1 is the predetermined rotation angle θ a The magnitude of the torque to exceed the first rotation angle θ1 is a The first rotation angle θ1 may be 10 times or more and 12 times or less of the torque required to achieve the predetermined rotation angle θ a By suddenly increasing the magnitude of the torque to exceed this, it is possible to prevent the electric motors 25L and 25R from stopping against the intention of the caregiver.

[0135] The support members 210 and 220 may support the arm portion 81 and the arm portion 82 in a state where the second torsion spring 80 has not been twisted in advance. FIG. 15 is a diagram showing the relationship between the first rotation angle θ1 and the force F1 in a state where the second torsion spring 80 has not been twisted in advance. Even in this state, the first rotation angle θ1 may not be equal to the predetermined rotation angle θ against the intention of the caregiver. b As a result, the electric motors 25L and 25R can be prevented from stopping.

[0136] Next, a modified example of the mechanism by which the first torsion spring 70 and the second torsion spring 80 apply elastic force to the accelerator lever 51 will be described.

[0137] Fig. 16 is a diagram illustrating a portion of the interior of the operating device 50 as viewed from above. In the example shown in Fig. 16, a case 230 is provided in the first housing 53a. The case 230 houses the rotating shaft 52, the first torsion spring 70, the second torsion spring 80, the magnet 92, and the support members 210 and 220. The angle sensor 91 is provided in the case 230.

[0138] Fig. 17 is a diagram showing part of the inside of the case 230 as seen from above. In the example shown in Fig. 17, the operating device 50 is equipped with two first torsion springs 70. The second torsion spring 80 is a single torsion spring.

[0139] The rotating shaft 52 is rotatably supported by the case 230. The support members 210 and 220 are provided on the rotating shaft 52. As described above, the rotating shaft 52 and the support members 210 and 220 have a fastening structure that suppresses misalignment of the accelerator lever 51 in the rotational direction.

[0140] Arm portion 71 of first torsion spring 70 is supported by support member 210. Case 230 is provided with stopper 57 that comes into contact with arm portion 72 to restrict movement of arm portion 72. Support member 210 is provided with magnet 92.

[0141] The arm portion 81 of the second torsion spring 80 is supported by a support member 220. A stopper 58 is provided on the case 230 to limit the range of movement of the arm portion 82 in conjunction with the rotation of the accelerator lever 51. When the first rotation angle θ1 of the accelerator lever 51 is equal to or smaller than the predetermined rotation angle θ a When the first rotation angle θ1 is smaller than the predetermined rotation angle θ a When this occurs, the stopper 58 comes into contact with the arm portion 82 and restricts the movement of the arm portion 82 in conjunction with the rotation of the accelerator lever 51 .

[0142] A root portion 51a of the accelerator lever 51 is attached to the right end of the rotary shaft 52. In the example shown in Fig. 16, the root portion 51a is attached to only one of the ends of the rotary shaft 52. In the embodiments shown in Figs. 6 and 7, the root portion 51a may also be attached to only one of the ends of the rotary shaft 52.

[0143] The configurations shown in FIGS. 16 and 17 also provide the same effects as those of the above-described embodiments.

[0144] In the above-described embodiment, the first rotation angle θ1 is set to the predetermined rotation angle θ b Although the processor 111 performs control to stop the electric motors 25L and 25R when the calculated first rotation angle θ1 is equal to or greater than the predetermined rotation angle θ, the processors 111 and 121 may cooperate to perform this control. b When this is the case, a command to stop the motors is sent to processor 111. Upon receiving the command, processor 111 stops electric motors 25L and 25R.

[0145] The angle sensor 91 is not limited to a magnetic sensor, but may be, for example, a potentiometer.

[0146] The root portion 51a of the accelerator lever 51 is not limited to a U-shape. For example, as shown in Fig. 16, the root portion 51a may be attached to only one of the ends of the rotary shaft 52. The root portion 51a may also be attached to the center of the rotary shaft 52 in the left-right direction.

[0147] The electric wheelchair 1 may be an electrically assisted wheelchair in which the force exerted by a person on hand-operated hand rims is assisted by an electric motor.

[0148] Next, an embodiment will be described in which two angle sensors are provided to output signals corresponding to the rotation angle of the accelerator lever 51.

[0149] 18 is a block diagram showing the hardware configuration of the operation device 50. The operation device 50 shown in FIG.

[0150] Like angle sensor 91, angle sensor 291 is, for example, a magnetic sensor, and is provided in first housing 53a. A magnet that applies a magnetic field to angle sensor 291 is provided in support member 210 or 220. Angle sensor 291 is not limited to a magnetic sensor and may be, for example, a potentiometer. Angle sensor 91 may be referred to as a first angle sensor, and angle sensor 291 may be referred to as a second angle sensor.

[0151] 19 to 24 are diagrams showing the control of electric motors 25L and 25R using angle sensor 91 and angle sensor 291. The horizontal axis of the graphs shown in Fig. 19 to 24 represents the first rotation angle θ1 of accelerator lever 51. The vertical axis represents the detection values ​​of angle sensors 91 and 291.

[0152] The control device 120 performs AD conversion or the like on the output signal of the first angle sensor 91 to convert it into a numerical value that gradually changes in accordance with changes in the first rotation angle θ1 of the accelerator lever 51. The solid line in Fig. 19 indicates the detection value 301 obtained by converting the output signal of the first angle sensor 91.

[0153] The control device 120 performs AD conversion or the like on the output signal of the second angle sensor 291 to convert it into a binary detection value represented by 0 and 1. The dotted line in FIG. 19 indicates the detection value 302 obtained by converting the output signal of the second angle sensor 291. The binary detection value 302 is, for example, c When the first rotation angle θ1 is less than θ c In the above cases, it shows "1". Rotation angle θ c is a value greater than 0 degrees. The dashed line in Fig. 19 indicates rotational speed command value 303 for electric motors 25L and 25R. Detection values ​​301 and 302 may be generated from the output signals of angle sensors 91 and 291 using a conversion method other than AD conversion.

[0154] When the detection value 301 of the first angle sensor 91 is less than V(min), the processor 111 (FIG. 3) does not rotate the electric motors 25L and 25R. The rotation angle when the detection value 301 is V(min) is defined as θ d Let θ d is θ c It can be a value greater than

[0155] The first rotation angle θ1 is θ d When the detected value 301 reaches or exceeds V(min), the processor 111 performs control to increase the rotation speeds of the electric motors 25L and 25R in accordance with an increase in the first rotation angle θ1.

[0156] 20 shows a state in which a malfunction occurs in the operating device 50 and the detection value 301 is equal to or greater than V(min) when the first rotation angle θ1 is 0 degrees. In this embodiment, when the detection value 302 of the second angle sensor 291 indicates "0", the processor 111 controls the electric motors 25L and 25R not to rotate, regardless of the magnitude of the detection value 301. Therefore, even when a malfunction as shown in FIG. 20 occurs, the first rotation angle θ1 is equal to or greater than θ cWhen the first rotation angle θ1 is less than θ2, the electric motors 25L and 25R can be stopped. Fig. 21 shows a control that prevents the electric motors 25L and 25R from rotating when the detection value 302 of the second angle sensor 291 indicates "0", regardless of the magnitude of the detection value 301. c When the detected value 302 indicates "0", the rotation speeds of the electric motors 25L and 25R are set to zero.

[0157] If a malfunction occurs in the operating device 50, the processor 121 uses the notification component 65 and / or the display panel 61 to notify the caregiver that a malfunction has occurred.

[0158] 22 shows a state in which a malfunction has occurred in which the detection value 302 of the second angle sensor 291 always indicates "1." Even if the detection value 301 of the first angle sensor 91 is the value when the first rotation angle θ1 is 0 degrees, if the detection value 302 of the second angle sensor 291 indicates "1," the processor 121 determines that a malfunction has occurred in the operating device 50 and notifies the caregiver.

[0159] If a malfunction occurs that causes the detection value 302 to always indicate "1", the detection value 302 will indicate "1" immediately after the power supply of the electric wheelchair 1 is switched from OFF to ON. In such a case, the processor 121 will not operate the electric motors 25L and 25R, will determine that a malfunction has occurred in the operating device 50, and will notify the caregiver.

[0160] If the caregiver is already operating the accelerator lever 51 when the power is turned on, the detection value 302 indicates "1" immediately after the power is turned on. In such a case, the processor 121 does not operate the electric motors 25L and 25R. When the caregiver receives a notification from the operation device 50 and releases his / her hand from the accelerator lever 51, the detection value 302 returns to "0" and the normal operating state can be restored.

[0161] 23 and 24 are diagrams showing another example of control of the electric motors 25L and 25R using the angle sensor 91 and the angle sensor 291. In the example shown in FIG. 23, the rotation angle θ c and the rotation angle θ corresponding to V(min) d and have the same magnitude. FIG. 24 shows a state in which a malfunction occurs in the operating device 50 in the control shown in FIG. 23, and the detected value 301 is equal to or greater than V(min) when the first rotation angle θ1 is 0 degrees. In this case, too, when the detected value 302 indicates "0", the processor 111 performs control not to rotate the electric motors 25L and 25R regardless of the magnitude of the detected value 301. As a result, when the first rotation angle θ1 is θ c When the electric motors 25L and 25R are less than the predetermined value, the processor 121 can stop the electric motors 25L and 25R. The processor 121 notifies the caregiver that a malfunction has occurred in the operating device 50.

[0162] 25 is a diagram showing an embodiment in which the detection value 301 when the first rotation angle θ1 is 0 degrees is set to V(min). In the above-described embodiment, the electric motors 25L and 25R are started after the accelerator lever 51 is rotated a predetermined angle. In the example shown in FIG. 25, the electric motors 25L and 25R can be operated immediately after the accelerator lever 51 starts to rotate from the neutral position.

[0163] Exemplary embodiments of the present invention have been described above.

[0164] A motor control system 100 according to an embodiment of the present invention is a motor control system 100 used in an electric vehicle 1, and includes an accelerator lever 51 operated by a user, a housing 53 that rotatably supports the accelerator lever 51, an angle sensor 91 that outputs a signal according to the rotation angle of the accelerator lever 51, and a control device 110 that controls the operation of electric motors 25L and 25R that generate driving force for running the electric vehicle 1, the control device 110 performing control to increase the rotation speed of the electric motors 25L and 25R according to an increase in a first rotation angle θ1 that is the rotation angle of the accelerator lever 51 in a first rotation direction D1 from a reference position of the accelerator lever 51, and a first torsion spring 70 having a coil portion 73 through which a rotation shaft 52 of the accelerator lever 51 passes and that applies a first elastic force to the accelerator lever 51 in a second rotation direction D2 that is opposite to the first rotation direction D1, and the control device 110 controls the first rotation angle θ1 to be equal to or greater than a first predetermined rotation angle θ b If it is detected that the electric motors 25L and 25R have reached this level, control is performed to stop the electric motors 25L and 25R.

[0165] According to one embodiment of the present invention, the first rotation angle θ1 of the accelerator lever 51 is set to a first predetermined rotation angle θ b If this occurs, the electric motors 25L and 25R are stopped. The user can stop the electric motors 25L and 25R simply by increasing the amount of operation of the accelerator lever 51. The electric vehicle 1 can be stopped without returning the accelerator lever 51 to the reference position (for example, the neutral position), which improves user convenience.

[0166] A first torsion spring 70 is used as an elastic member that generates a force in a direction that returns the accelerator lever 51 to the reference position. By passing the rotation shaft 52 of the accelerator lever 51 through the inside of the coil portion 73 of the first torsion spring 70, the first torsion spring 70 and the rotation shaft 52 can share the same space, and the space required for arranging the elastic member can be reduced. This allows for greater freedom in arranging other components included in the motor control system 100, and also enables the motor control system 100 to be made more compact.

[0167] In one embodiment, the motor control system 100 further includes a second torsion spring 80 having a coil portion 83 through which the rotation shaft 52 of the accelerator lever 51 passes, the second torsion spring 80 applying a second elastic force in a second rotation direction D2 to the accelerator lever 51, and the second elastic force is greater than 0 degrees and is set at a first predetermined rotation angle θ b The second predetermined rotation angle θ a When the first rotation angle θ1 is set to the second predetermined rotation angle θ a When the second elastic force is not applied to the accelerator lever 51, the first rotation angle θ1 is equal to or smaller than the second predetermined rotation angle θ a If this is the case, a second elastic force may be applied to the accelerator lever 51.

[0168] The first rotation angle θ1 of the accelerator lever 51 is set to the second predetermined rotation angle θ a When this occurs, the second torsion spring 80 applies a second elastic force to the accelerator lever 51, which causes the magnitude of the force required for the user to move the accelerator lever 51 to suddenly increase. This causes the first rotation angle θ1 to suddenly increase beyond the first predetermined rotation angle θ b As a result, the electric motors 25L and 25R can be prevented from stopping.

[0169] A first predetermined rotation angle θ at which the electric motors 25L and 25R are stopped b is the second predetermined rotation angle θ at which the second torsion spring 80 begins to apply the second elastic force to the accelerator lever 51. a The second predetermined rotation angle θ a By not stopping the electric motors 25L and 25R in this state, it is possible to prevent the electric motors 25L and 25R from stopping against the user's intention.

[0170] As described above, when the first rotation angle θ1 of the accelerator lever 51 is equal to the second predetermined rotation angle θ aWhen this occurs, the amount of force required for the user to move the accelerator lever 51 increases rapidly. This allows the user to recognize that the accelerator lever 51 is approaching an operating position where the electric motors 25L and 25R will stop. If the user does not want to stop the electric vehicle 1, the user can continue driving the electric vehicle 1 by not moving the accelerator lever 51 further in the first rotation direction D1. If the user wants to stop the electric vehicle 1, the user can stop the electric motors 25L and 25R by moving the accelerator lever 51 further in the first rotation direction D1.

[0171] The first rotation angle θ1 is the second predetermined rotation angle θ a As a result, second torsion spring 80 is used as an elastic member that applies a second elastic force to accelerator lever 51. By passing rotation shaft 52 of accelerator lever 51 through the inside of coil portion 83 of second torsion spring 80, second torsion spring 80 and rotation shaft 52 can share the same space, and the space required for arranging the elastic member can be reduced. This increases the degree of freedom in arranging other components included in motor control system 100 and enables motor control system 100 to be made more compact.

[0172] In some embodiments, the spring constant of the second torsion spring 80 may be greater than the spring constant of the first torsion spring 70 .

[0173] The second elastic force applied to the accelerator lever 51 by the second torsion spring 80 can be increased, and the first rotation angle θ1 can be increased to the first predetermined rotation angle θ b As a result, the electric motors 25L and 25R can be prevented from stopping.

[0174] For example, by increasing the wire diameter of the wire material that makes up the second torsion spring 80 or by using harder wire material, the spring constant of the second torsion spring 80 can be increased while keeping the size of the second torsion spring 80 small.

[0175] In one embodiment, the second torsion spring 80 has a first arm portion 81 and a second arm portion 82 extending from a coil portion 83 of the second torsion spring 80, and the motor control system 100 includes support members 210 and 220 that are provided on the rotation shaft 52 of the accelerator lever 51 and support the first arm portion 81 so that the first arm portion 81 moves in conjunction with the rotation of the accelerator lever 51, and a stopper 58 that limits the range of movement of the second arm portion 82 in conjunction with the rotation of the accelerator lever 51, and the stopper 58 is configured to limit the range of movement of the second arm portion 82 in conjunction with the rotation of the accelerator lever 51 when the first rotation angle θ1 is greater than or equal to the second predetermined rotation angle θ2. a When the rotation angle θ1 is smaller than the second predetermined rotation angle θ2, the arm 81 does not come into contact with the second arm portion 82, and the first rotation angle θ1 is smaller than the second predetermined rotation angle θ2. a If this occurs, the second arm portion 82 may come into contact with the second arm portion 82, and the movement of the second arm portion 82 linked to the rotation of the accelerator lever 51 may be restricted.

[0176] The first rotation angle θ1 of the accelerator lever 51 is set to the second predetermined rotation angle θ a When this occurs, the second torsion spring 80 can apply a second elastic force to the accelerator lever 51.

[0177] In one embodiment, the support members 210 and 220 may support the first arm portion 81 and the second arm portion 82 in a state in which the second torsion spring 80 is twisted in advance by a predetermined amount in the direction in which the second torsion spring 80 twists in response to rotation of the accelerator lever 51 in the first rotational direction D1.

[0178] By twisting the second torsion spring 80 by a predetermined amount in advance, a large elastic force can be applied to the accelerator lever 51 from the stage when the second torsion spring 80 starts to apply the second elastic force to the accelerator lever 51. This allows the amount of force required for the user to move the accelerator lever 51 to increase more rapidly.

[0179] In one embodiment, the first rotation angle θ1 is equal to or smaller than the second predetermined rotation angle θ a The magnitude of the torque to exceed the first rotation angle θ1 is calculated by multiplying the first rotation angle θ1 by the second predetermined rotation angle θ a The torque may be 10 times or more and 12 times or less the torque for achieving this.

[0180] The first rotation angle θ1 is the second predetermined rotation angle θ a By suddenly increasing the magnitude of the torque to exceed this value, it is possible to prevent the electric motors 25L and 25R from stopping against the user's will.

[0181] In one embodiment, the motor control system 100 may further include fastening structures 214, 224, 254 between the rotation shaft 52 of the accelerator lever 51 and the support members 210 and 220, which suppress misalignment of the accelerator lever 51 in the rotational direction.

[0182] This makes it possible to suppress misalignment between the rotation axis 52 of the accelerator lever 51 and the second torsion spring 80 supported by the support members 210 and 220, and to keep constant the magnitude of the first rotation angle θ1 at which the second torsion spring 80 begins to apply the second elastic force to the accelerator lever 51.

[0183] In one embodiment, the second torsion spring 80 is a double torsion spring, which has two coil portions 83 lined up along a first direction (left-right direction), and the double torsion spring has two arm portions extending from both ends of the double torsion spring 80 in the first direction as one of the first arm portion 81 and the second arm portion 82, and the other arm portion of the first arm portion 81 and the second arm portion 82 may be located between the two coil portions 83 in the first direction and connect the two coil portions 83.

[0184] By using a double torsion spring having two coil portions 83 as the second torsion spring 80, it is possible to increase the second elastic force applied to the accelerator lever 51. Because the stress acting on the second torsion spring 80 can be distributed to the two coil portions 83, it is possible to increase the durability of the second torsion spring 80 even when the second elastic force is large.

[0185] In one embodiment, the first predetermined rotation angle θ b is the second predetermined rotation angle θ aIt may be 2 to 5 degrees larger than

[0186] The second predetermined rotation angle θ at which the second torsion spring 80 begins to apply the second elastic force to the accelerator lever 51 a A first predetermined rotation angle θ that is slightly larger than b When the first rotation angle θ1 reaches the second predetermined rotation angle θ, the electric motors 25L and 25R are stopped. a By not stopping the electric motors 25L and 25R when the electric motors 25L and 25R reach the predetermined value, it is possible to prevent the electric motors 25L and 25R from stopping against the user's intention.

[0187] In one embodiment, the second predetermined rotation angle θ a may be between 20 degrees and 30 degrees.

[0188] The accelerator lever 51 can be rotated within an angle range that allows the user to easily adjust the traveling speed of the electric vehicle 1.

[0189] In one embodiment, the motor control system 100 further includes a magnet 92 that moves in conjunction with the rotation of the accelerator lever 51, and the angle sensor 91 is a magnetic sensor that may be supported on the housing 53 so as not to move in conjunction with the rotation of the accelerator lever 51.

[0190] By using a magnetic sensor, it is possible to accurately detect the rotation angle of the accelerator lever 51. By using a non-contact magnetic sensor, it is possible to increase the durability of the angle sensor 91.

[0191] By providing angle sensor 91, from which the electric wire extends, so that it does not move in conjunction with the rotation of accelerator lever 51, the durability of angle sensor 91 can be increased.

[0192] In one embodiment, the base portion 51 a of the accelerator lever 51 may be connected to both ends of the rotary shaft 52 .

[0193] The first torsion spring 70 and the second torsion spring 80 can be disposed in the area surrounded by the base portion 51 a of the accelerator lever 51 .

[0194] When the accelerator lever 51 is rotated in the direction of rotation, the base portion 51a of the accelerator lever 51 comes into contact with the housing 53, thereby determining the neutral position of the accelerator lever 51.

[0195] In one embodiment, the housing 53 may be provided with a hole 54 that allows the handlebar 45a of the electric vehicle 1 to pass through the housing 53.

[0196] When the motor control system 100 is retrofitted to the electric vehicle 1, the position of the grip 46 originally intended for the electric vehicle 1 can be maintained, and the user can operate the accelerator lever 51 while holding the grip 46.

[0197] A drive unit 10 according to an embodiment of the present invention includes the motor control system 100 described above, and electric motors 25L and 25R that generate driving force for propelling the electric vehicle 1.

[0198] By installing the drive unit 10 in the electric vehicle 1, it is possible to improve convenience for the user.

[0199] An electric vehicle 1 according to an embodiment of the present invention includes the drive unit 10 described above.

[0200] This makes it possible to realize an electric vehicle 1 that is highly convenient for the user.

[0201] In one embodiment, the electric vehicle 1 may be an electric wheelchair.

[0202] This makes it possible to realize an electric wheelchair that is highly convenient for caregivers. [Industrial Applicability]

[0203] The present invention is particularly useful in the field of electric vehicles. [Explanation of symbols]

[0204] 1: electric wheelchair (electric vehicle), 2L, 2R: wheel, 3L, 3R: hand rim, 4: body frame, 5L, 5R: caster, 6: seat, 7: battery, 8: armrest, 9: backrest, 10: drive unit, 15: operation device, 16: stick, 21: wheel hub, 22: spoke, 23: outer periphery, 24: connecting member, 25L, 25R: electric motor, 26L, 26R: speed sensor, 41: seat frame, 42: armrest frame, 43: base frame, 44: underframe, 45: back frame, 45a: handlebar, 46: hand grip, 47: footrest, 50: operation device, 51: accelerator lever, 51a: base portion, 51b: hole, 52: rotating shaft, 53: housing, 53a: First housing, 53b: Second housing, 54: Hole, 57: Stopper, 58: Stopper, 61: Display panel, 62: Power switch, 63: Mode selection switch, 64: Operation switch, 65: Notification component, 66: Electric wire, 67: Forward / reverse switch, 70: First torsion spring, 71: Arm portion, 72: Arm portion, 73: Coil portion, 80: Second torsion spring, 81: Arm portion, 82: Arm portion, 83: Coil portion, 91: Angle sensor, 92: Magnet, 93: Circuit board, 94: Cover, 100: Motor control system, 110: Control device, 111: Processor, 112: ROM, 113: RAM, 114L, 114R: Drive circuit, 120: Control device, 121: Processor, 122: ROM, 123: RAM, 210: Support member, 211: Cylinder portion, 212: Cylinder portion, 213: Cylinder portion, 214: Flat portion, 215: Notch portion, 216: Notch portion, 217: Hole, 220: Support member, 221: Cylinder portion, 222: Cylinder portion, 224: Flat portion, 225: Notch portion, 227: Hole, 230: Case, 251: Body portion, 252: Head portion, 254: Flat portion, 256: Hole, 257: Hole, θ1: First rotation angle, θ a : second predetermined rotation angle, θ b: First predetermined rotation angle, D1: First rotation direction, D2: Second rotation direction

Claims

1. A motor control system for use in an electric vehicle, an accelerator lever operated by a user; a housing that rotatably supports the accelerator lever; an angle sensor that outputs a signal corresponding to the rotation angle of the accelerator lever; a control device that controls operation of an electric motor that generates a driving force for running the electric vehicle, the control device performing control to increase a rotation speed of the electric motor in accordance with an increase in a first rotation angle that is a rotation angle of the accelerator lever in a first rotation direction from a reference position of the accelerator lever; a first torsion spring having a coil portion through which the rotation axis of the accelerator lever passes, the first torsion spring applying a first elastic force to the accelerator lever in a second rotation direction opposite to the first rotation direction; a second torsion spring having a coil portion through which the rotation shaft of the accelerator lever passes, the second torsion spring applying a second elastic force in the second rotation direction to the accelerator lever; Equipped with the control device performs control to stop the electric motor when detecting that the first rotation angle is equal to or greater than a first predetermined rotation angle; When a second predetermined rotation angle is set to a predetermined value that is larger than 0 degrees and smaller than the first predetermined rotation angle, the second torsion spring When the first rotation angle is smaller than the second predetermined rotation angle, the second elastic force is not applied to the accelerator lever, When the first rotation angle is equal to or greater than the second predetermined rotation angle, the second elastic force is applied to the accelerator lever.

2. The motor control system of claim 1 , wherein the spring constant of the second torsion spring is greater than the spring constant of the first torsion spring.

3. the second torsion spring has a first arm portion and a second arm portion extending from the coil portion of the second torsion spring, The motor control system includes: a support member provided on the rotation shaft of the accelerator lever and supporting the first arm portion so that the first arm portion moves in conjunction with rotation of the accelerator lever; a stopper that limits the range of movement of the second arm portion in conjunction with the rotation of the accelerator lever; Equipped with The stopper is When the first rotation angle is smaller than the second predetermined rotation angle, the second arm portion does not come into contact with the first rotation angle.

3. The motor control system according to claim 1, wherein when the first rotation angle becomes equal to or greater than the second predetermined rotation angle, the control unit contacts the second arm portion to suppress movement of the second arm portion linked to rotation of the accelerator lever.

4. 4. The motor control system according to claim 3, wherein the support member supports the first arm portion and the second arm portion in a state in which the second torsion spring is twisted in advance by a predetermined amount in a direction in which the second torsion spring twists in response to rotation of the accelerator lever in the first rotational direction.

5. 5. The motor control system according to claim 3, wherein the magnitude of the torque required for the first rotation angle to exceed the second predetermined rotation angle is between 10 and 12 times the magnitude of the torque required for making the first rotation angle the second predetermined rotation angle.

6. 6. The motor control system according to claim 3, further comprising a fastening structure that suppresses positional deviation of the accelerator lever in the rotational direction between the rotation shaft of the accelerator lever and the support member.

7. the second torsion spring is a double torsion spring, the double torsion spring has two of the coil portions arranged along a first direction, the double torsion spring has, as one of the first arm portion and the second arm portion, two arm portions extending from both ends of the double torsion spring in the first direction, 7. The motor control system according to claim 3, wherein the other of the first arm portion and the second arm portion is positioned between two of the coil portions in the first direction and connects the two coil portions.

8. 8. The motor control system according to claim 1, wherein the first predetermined rotation angle is 2 to 5 degrees greater than the second predetermined rotation angle.

9. 9. The motor control system according to claim 1, wherein the second predetermined rotation angle is equal to or greater than 20 degrees and equal to or less than 30 degrees.

10. Further, a magnet is provided which moves in conjunction with the rotation of the accelerator lever, 10. The motor control system according to claim 1, wherein the angle sensor is a magnetic sensor and is supported by the housing so as not to move in conjunction with the rotation of the accelerator lever.

11. 11. The motor control system according to claim 1, wherein a base portion of the accelerator lever is connected to both ends of the rotary shaft.

12. The motor control system according to claim 1 , wherein the housing is provided with a hole that allows a handlebar of the electric vehicle to pass through the housing.

13. A motor control system according to any one of claims 1 to 12; an electric motor that generates a driving force for running the electric vehicle; A drive unit comprising:

14. An electric vehicle comprising the drive unit according to claim 13.

15. The electric vehicle of claim 14, wherein the electric vehicle is an electric wheelchair.

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