JP2015013009A - Wheelchair with auxiliary motive power, and setting method of wheelchair with auxiliary motive power - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a favorable drive feeling even if positions of neutral points Xmf, Xmb of a hand rim 4 differ from each other depending on an operation direction of the hand rim 4.SOLUTION: A dead zone Z2 in displacement amounts X of conversion characteristics f3f2 is set so as to include a neutral point Xmf at which a hand rim 4 displaced to an advance direction Df with respect to a wheel 3 returns to a backing direction Db by elastic forces of springs S1 and S2, and remains stationary, and a neutral point Xmb at which the hand rim 4 displaced to the backing direction Db with respect to the wheel 3 returns to the advance direction Df by the elastic forces of the springs S1 and S2, and remains stationary. By including the neutral points Xmf and Xmb, different in positions depending on an operation direction, in the dead zone Z2 of the conversion characteristics f3f2, an influence on an operation feeling exerted by the different positions of the neutral points Xmf and Xmb depending on the operation direction is alleviated, and a favorable drive feeling can be obtained.

Description

  The present invention relates to a wheelchair that rotates a wheel with torque applied to a hand rim, and more particularly, to a wheelchair with auxiliary power that assists the operation of the wheelchair by giving the wheel auxiliary power according to the torque applied to the hand rim. .

  In the wheelchair of Patent Document 1, the hand rim is provided so as to be rotatable with respect to the wheel, and the wheel and the hand rim are connected via an elastic member. Therefore, when an occupant of the wheelchair applies torque to the hand rim, the torque is transmitted from the hand rim to the wheel via the elastic member, and the wheel rotates. Further, the wheelchair includes a mechanism that assists driving of the wheelchair by giving the wheel auxiliary power corresponding to the torque applied to the hand rim.

  That is, in the wheelchair in which the hand rim and the wheel are connected by the elastic member, the elastic member is deformed according to the torque applied to the hand rim, so that the hand rim is displaced with respect to the wheel by the amount of displacement corresponding to the applied torque. Therefore, the torque applied to the hand rim can be obtained from the displacement amount of the hand rim with respect to the wheel. Therefore, this wheelchair obtains the torque applied to the hand rim from the result of detecting the displacement amount of the hand rim with respect to the wheel using a potentiometer or the like, and gives auxiliary power corresponding to the torque to the wheel.

JP 09-154894 A

  In the wheelchair with auxiliary power as described above, when the occupant operates the hand rim and applies torque to the hand rim, the hand rim is displaced in the operation direction with respect to the wheel, and auxiliary power for driving the wheel in the operation direction is generated. When the occupant stops applying the torque to the hand rim, the hand rim returns to the neutral point by the elastic force of the elastic member, so that the auxiliary power applied to the wheels disappears.

  However, since a frictional force acts on the hand rim, the hand rim that returns by the elastic force after being displaced in the operation direction is stationary at a position where the resultant force including the elastic force and the frictional force becomes zero. As a result, the stationary position of the hand rim, that is, the neutral point, tends to be biased in the direction (operation direction) in which the hand rim has been displaced before the hand rim is stationary. Moreover, since the hand rim of the wheelchair is operated in both the forward direction and the reverse direction by the occupant, the position of the neutral point may differ between the forward direction and the reverse direction. Such a situation may affect the driving sensation of a wheelchair by an occupant. Therefore, in order to realize a good driving sensation, it is preferable that the auxiliary power can be controlled in consideration of this point.

  The present invention has been made in view of the above problems, and even when the position of the neutral point of the hand rim differs depending on the direction of operation of the hand rim, setting of the wheelchair with auxiliary power and the wheelchair with auxiliary power that can realize a good driving feeling It aims to provide a method.

  In order to achieve the above object, a wheelchair with auxiliary power according to the present invention includes a rotatable wheel and a hand rim that is rotatable with respect to the wheel in both directions of a first direction and a second direction opposite to the first direction. An elastic member that connects between the wheel and the hand rim and deforms according to the torque applied to the hand rim, a control unit that converts the displacement of the hand rim with respect to the wheel into a drive signal, and auxiliary power according to the drive signal A driving source applied to the wheel, and the control unit converts the displacement amount into a driving signal according to a predetermined conversion characteristic, and the hand rim displaced in the first direction with respect to the wheel moves in the second direction by the elastic force of the elastic member. The conversion characteristic is such that the first neutral point returned and stationary and the hand rim displaced in the second direction with respect to the wheel includes the second neutral point returned and stationary in the first direction by the elastic force of the elastic member. Against displacement Dead zone has been set.

  In order to achieve the above object, a setting method for a wheelchair with auxiliary power according to the present invention is a rotatable wheel, a hand rim that is rotatable with respect to a wheel in both directions of a first direction and a second direction opposite to the first direction. An elastic member that connects between the wheel and the hand rim and deforms according to the torque applied to the hand rim, a control unit that converts the displacement of the hand rim with respect to the wheel into a drive signal, and auxiliary power according to the drive signal In a setting method of a wheelchair with auxiliary power for setting a conversion characteristic of a control unit that converts a displacement amount into a drive signal for a wheelchair with auxiliary power provided with a driving source to be applied to the wheel, the wheel is displaced in the first direction. A step of obtaining the first neutral point where the hand rim is returned to the second direction by the elastic force of the elastic member and stationary, and the hand rim displaced in the second direction with respect to the wheel is caused by the elastic force of the elastic member. It includes a step of obtaining a second neutral point stationary back in one direction, and a step of setting a dead zone with respect to the displacement amount of the conversion characteristics so as to include a first neutral point and the second neutral point.

  In the wheelchair with auxiliary power according to the present invention (the wheelchair with auxiliary power and the setting method of the wheelchair with auxiliary power) configured as described above, the first direction and the second direction opposite to the first direction are bidirectional with respect to the wheels. The wheel and the hand rim are connected by an elastic member that deforms according to the torque applied to the hand rim. Therefore, the hand rim is displaced with respect to the wheel by an amount of displacement corresponding to the torque applied to the hand rim. Furthermore, the wheelchair includes a control unit that converts a displacement amount of the hand rim with respect to the wheel into a drive signal, and a drive source that applies auxiliary power corresponding to the drive signal to the wheel. As a result, auxiliary power corresponding to the torque applied to the hand rim is applied to the wheels.

  In the present invention, the conversion characteristic for converting the displacement amount of the hand rim into a drive signal has a dead zone with respect to the displacement amount. Therefore, even when the occupant operates the hand rim, auxiliary power is not generated during a period in which the displacement amount of the hand rim is in the dead zone range. On the other hand, when the displacement amount of the hand rim reaches the end of the dead zone, the auxiliary power starts to work. After the displacement amount of the hand rim comes out of the dead zone, the auxiliary power corresponding to this displacement amount is applied to the wheel.

  In the present invention, the dead zone of the conversion characteristic is set based on the neutral point of the hand rim. Specifically, the hand rim displaced in the first direction with respect to the wheel returns to the second direction by the elastic force of the elastic member, and the hand rim displaced in the second direction with respect to the wheel is elastic. The dead zone for the displacement amount of the conversion characteristic is set so as to include the second neutral point that returns to the first direction and stops by the elastic force of the member. In this way, by including the first and second neutral points having different positions depending on the operation direction in the dead zone of the conversion characteristics, the influence on the operation feeling that the position of the neutral point varies depending on the operation direction is improved. It is possible to achieve a driving sensation.

  From the viewpoint of improving driving sensation, it is preferable to stop the wheelchair by stopping the generation of auxiliary power when the occupant releases his hand from the hand rim. In contrast, according to the present invention in which the dead zone is set so as to include the first and second neutral points, when the occupant releases his hand from the hand rim and the hand rim is at the first or second neutral point, No auxiliary power is generated. In other words, after the wheelchair stops, there is an advantage that the wheelchair continues to stop even if the occupant releases his hand from the hand rim.

  At this time, the conversion characteristic may be set so that the center of the dead zone of the conversion characteristic coincides with the center of the first neutral point and the second neutral point. In such a configuration, the displacement amount of the hand rim from the first neutral point to the end of the dead zone in the first direction and the displacement amount of the hand rim from the second neutral point to the end of the dead zone in the second direction. And become equal. Therefore, when the occupant operates the hand rim from the first neutral point in the first direction and when the hand rim operates from the second neutral point in the second direction, the amount of operation of the hand rim until the auxiliary power starts to work is equal. Become. As a result, it is possible to effectively suppress the influence of the position of the neutral point depending on the operation direction on the operation sensation, and to realize a very good driving sensation.

  The control unit may be configured to include a detector that detects a displacement amount and converts it into a detection signal, and a control circuit that converts the detection signal output from the detector into a drive signal.

  At this time, the detector may be configured such that the gain for converting the detection signal into the drive signal is adjusted based on the gain at which the detector converts the displacement amount into the detection signal. In this way, by adjusting the gain for converting the detection signal of the detector into the drive signal based on the gain of the detector that detects the amount of displacement, the gain of the detector attached to the wheelchair at the manufacturing site of the wheelchair can be increased. Even if the detectors vary, a wheelchair that outputs a stable drive signal can be obtained.

  Further, the range in which the hand rim is displaced with respect to the wheel is limited to a predetermined variable range, and the control unit detects the detection signal when the hand rim is positioned at the end of the variable range in the first direction, and the first neutral point. And the absolute value of the detection signal output range, which is the difference between the detection signal when the hand rim is located at the center of the second neutral point, is equal to or less than the threshold value, it may be determined that an abnormality has occurred. In such a configuration, the detection signal output range (that is, the output range of the detection signal from the center of the first neutral point and the second neutral point to the end of the variable range in the first direction) is not sufficiently ensured. Is determined to be abnormal. Therefore, the maintenance for securing the detection signal output range can be performed as necessary, which is preferable.

  Alternatively, in a wheelchair with auxiliary power provided with a pair of wheels and a hand rim, an elastic member, a controller, and a drive source corresponding to each wheel, the range in which the hand rim is displaced with respect to the wheels is a predetermined variable range. The control unit is configured to detect a detection signal when the hand rim is positioned at the end of the variable range in the first direction and a detection signal when the hand rim is positioned at the center between the first neutral point and the second neutral point. As a result of obtaining the difference as a detection signal output range for each wheel, it is abnormal if the absolute value of the difference between the detection signal output range obtained for one wheel and the detection signal output range obtained for the other wheel is greater than or equal to a threshold value. You may comprise so that it may be judged that this occurred. In such a configuration, when the detection signal output range is greatly different between the pair of wheels, it is determined as abnormal. Therefore, it is preferable that maintenance for aligning the detection signal output range between the pair of wheels can be performed as necessary.

  In this case, a communication unit that communicates between the control unit of one wheel and the control unit of the other wheel is further provided, and the control unit corresponding to one wheel obtains a detection signal output range for one wheel, and the other The control unit corresponding to the other wheel obtains the detection signal output range for the other wheel, and the control unit corresponding to the one wheel receives the other wheel received from the control unit corresponding to the other wheel via the communication unit. The detection signal output range and the detection signal output range for one of the wheels determined by itself may be configured to determine whether or not there is an abnormality.

  Furthermore, when a control part judges that abnormality has arisen, you may comprise so that the alerting | reporting part which alert | reports generation | occurrence | production of abnormality may be further provided. In such a configuration, it is possible to notify the occupant of the wheelchair, an assistant, or an operator who sets the wheelchair, etc., and prompt the execution of necessary maintenance.

  According to the present invention, by including the first and second neutral points having different positions depending on the operation direction in the dead zone of the conversion characteristics, the influence on the operation feeling that the position of the neutral point varies depending on the operation direction can be reduced. It is possible to achieve a good driving feeling.

It is a left view which shows an example of the wheelchair with auxiliary power which can apply this invention. It is the rear view which looked at the wheelchair with auxiliary power illustrated in Drawing 1 from back. It is front sectional drawing which expands and shows the surrounding structure of a power assistance mechanism. It is a side view which shows the surrounding structure of the power assistance mechanism at the time of removing a circular cover and an annular cover. It is a fragmentary sectional view which shows the positional relationship of the spring cover, spring, and rim base which were attached to the wheel hub. It is a side view which shows a mode that the rim base was displaced with respect to the wheel hub according to the torque applied to the hand rim. It is front sectional drawing which expands and shows the circumference | surroundings of the displacement amount detector with which a power assistance mechanism is provided. It is a side view which shows the relationship of each member which comprises a displacement amount detector. It is a side view which shows the relationship of each member which comprises a displacement amount detector. It is a side view which illustrates the arrangement | positioning aspect of a displacement amount detector. It is a block diagram which shows partially the electric constitution with which a wheelchair with auxiliary power is provided. It is a figure which shows typically a mode that each signal is produced | generated from the torque applied to the hand rim. It is a flowchart which shows an example of the setting operation | work performed with respect to a wheelchair. It is a flowchart which shows an example of the gain adjustment performed with the flowchart of FIG. It is a figure which shows an example of a dead zone setting performed with the flowchart of FIG. It is a flowchart which shows an example of the operation | movement which a wheelchair provided with an abnormality detection function performs. It is a flowchart which shows the other example of the operation | movement which a wheelchair provided with an abnormality detection function performs.

  FIG. 1 is a left side view showing an example of a wheelchair with auxiliary power to which the present invention can be applied. FIG. 2 is a rear view of the auxiliary power wheelchair illustrated in FIG. 1 as viewed from the rear. In both figures and the drawings shown below, as viewed from the occupant seated in the wheelchair 1, the reference sign Df is assigned in the forward direction, the reference sign Db in the rearward direction, the reference sign D1 in the left direction, and the reference sign Dr in the right direction. A wheelchair 1 with auxiliary power (hereinafter simply referred to as “wheelchair” as appropriate) illustrated in the present embodiment is a pair of left and right wheels 3 and a pair of left and right hand rims 4 with respect to a body frame 2 formed of pipes. It has a schematic configuration with a pair of left and right casters C attached, and stands on the ground with wheels 3 and casters C. The occupant can drive the wheelchair 1 by rotating the wheel 3 by operating the hand rim 4 while seated on the seat 11 provided at the center of the wheelchair 1. At this time, the power assist mechanism 10 provided on each wheel 3 gives assist power to the wheel 3 to assist driving of the wheel 3 by an occupant.

  The body frame 2 has a pair of left and right side frames 20, and each side frame 20 is composed of a plurality of arms. Specifically, each side frame 20 includes a handle arm 21 erected at the rear portion, a seat support arm 22 extending forward from the handle arm 21, and a connection arm 23 connecting the handle arm 21 and the seat support arm 22. And have. The upper part of each handle arm 21 is bent backward, and a grip 21a for an assistant is attached to each upper part. Between the pair of left and right seat support arms 22, a cloth seat 11 for occupant sitting is laid, and between the pair of left and right handle arms 21, a seat occupant backrest 12 is laid. Yes. The front portion 22a of each seat support arm 22 is bent downward, and a footrest (not shown) is detachable from the footrest mounting portion 22b provided at the lower end of the front portion 22a. Further, each side frame 20 has a caster support arm 24 extending rearward from the front portion 22 a of the seat support arm 22, and the caster C is attached to a caster mounting portion 24 a provided on the caster support arm 24. .

  A battery 13 is attached to the right side frame 20 of the pair of left and right side frames 20. The battery 13 supplies power to the power assist mechanism 10 provided on each wheel 3, and is disposed behind the handle arm 21. The battery 13 supplies power to the power assist mechanism 10 provided on the left wheel 3 via the cable 14.

  Axles 30 are attached to the left and right sides of the body frame 2, and wheels 3 and hand rims 4 are attached to the respective axles 30 so as to be rotatable. Specifically, a circular wheel hub 5 disposed on the inner peripheral side of the annular wheel 3 centering on the axle 30 is rotatably attached to each axle 30, and the periphery of the wheel hub 5 is A plurality of spokes 31 extending from the part to the outer peripheral side are connected to the wheel 30. Thus, the wheel 3 is rotatable around the axle 30 integrally with the wheel hub 5. Further, the rim base 6 disposed on the inner peripheral side of the annular hand rim 4 centering on the axle 30 and outside the wheel hub 5 is rotatably attached to each axle 30. Three spokes 41 that extend radially from the peripheral portion to the outer peripheral side are connected to the hand rim 4. As a result, the hand rim 4 is rotatable around the axle 30 integrally with the rim base 6. The rim base 6 is rotatably provided independently of the wheel hub 5, and the hand rim 4 can rotate independently of the wheel 3 around the axle 30.

  Each hand rim 4 is in contact with the adjacent wheel 3 via an elastic member (a spring to be described later), and the torque applied by the occupant to the hand rim 4 is transmitted to the wheel 3 via the elastic member. Rotate. At this time, the hand rim 4 is displaced relative to the wheel 3 by an amount corresponding to the amount of deformation of the elastic member in response to the torque from the occupant. And the power assistance mechanism 10 with which the wheelchair 1 is equipped detects the torque added to the hand rim 4 based on the result of having measured the displacement amount of the hand rim 4 with respect to the wheel 3, and the auxiliary power according to the detected torque is applied to the wheel. Give to 3. Next, the power assist mechanism 10 will be described in detail.

  FIG. 3 is an enlarged front sectional view showing a configuration around the power assist mechanism. In the figure and the following drawings, an axle direction Da is appropriately attached in the left-right direction in which the axle 30 extends. The power assist mechanism 10 includes a power unit 9 that provides assist power to the wheels 3 inside the wheel hub 5 in the axle direction Da. The power unit 9 applies the driving force generated by the motor 91 to the wheel hub 5 via the power transmission system 95 configured by an arrangement of a plurality of gears to rotate the wheels 3.

  The motor 91 includes a motor shaft 912 that is rotatably attached to the axle 30 through a bearing 911, a rotor 913 that is attached to the motor shaft 912, and a stator 914 that faces the rotor 913 from the outside in the axle direction Da. . The rotor 913 includes an annular back yoke 913 a that is attached to the motor shaft 912 and centered on the axle 30, and an annular magnet 913 b that is attached to the outside of the back yoke 913 a in the axle direction Da and centered on the axle 30. It is configured. Then, the magnet 913 b of the rotor 913 faces the stator 914. The stator 914 has a configuration in which a plurality of coils are arranged in an annular shape around the axle 30, and is fixed to the axle 30. Therefore, when a current is applied to each coil of the stator 914, the rotor 913 rotates around the axle 30 with the motor shaft 912. Then, the torque of the motor shaft 912 is transmitted to the wheel hub 5 through the gears 951 to 955 of the power transmission system 95. In this way, the wheel 3 rotates together with the wheel hub 5 by receiving the power (auxiliary power) generated by the motor 91.

  The wheel hub 5 is attached to the axle 30 via a ball bearing 51. The peripheral edge 52 of the wheel hub 5 is bent inward in the axial direction Da and the spoke 31 is attached, while the central portion 53 of the wheel hub 5 is formed thick in the axial direction Da. The outer surface of the central portion 53 of the wheel hub 5 protrudes outward in the axle direction Da to form a rim base attachment portion 54. The rim base 6 is attached to the rim base attachment portion 54 of the wheel hub 5 via a ball bearing 61. As described above, the rim base 6 is attached to the axle 30 via the rim base attachment portion 54 of the wheel hub 5, and can rotate around the axle 30 independently of the wheel hub 5. The outer surfaces of the wheel hub 5 and the rim base 6 are covered with a circular cover J1 and an annular cover J2 surrounding the circular cover J1.

  Torque can be transmitted from the rim base 6 to the wheel hub 5 via springs S1, S2 (coil springs) of the power assist mechanism 10. That is, a cylindrical spring cover 56 is attached to a spring holding surface 55 provided between the peripheral edge portion 52 and the central portion 53 in the wheel hub 5, and the springs S 1 and S 2 (compression springs) are placed in the spring cover 56. ) Is generally arranged in the circumferential direction of the wheel hub 5. The diameter of the spring S1 is larger than the diameter of the spring S2, and the spring S2 is inserted into the spring S1. Further, at least one of the springs S1 and S2 is accommodated in the spring cover 56 in a contracted state (that is, a pressurized state).

  FIG. 4 is a side view showing a configuration around the power assist mechanism when the circular cover and the annular cover are removed, and shows a state in which no torque is applied to the hand rim 4. FIG. 5 is a partial cross-sectional view showing a positional relationship among a spring cover, a spring, and a rim base attached to the wheel hub, and shows a state viewed from the expansion / contraction direction of the spring. 4 and 5 are added to FIG. 3, and the description of the power assist mechanism 10 will be continued. As shown in FIG. 4, the three spring covers 56 are provided at an equal pitch in the circumferential direction. However, since the configurations related to the spring covers 56 are the same, one spring cover is used here. The configuration provided for 56 will be mainly described.

  A pair of sliders 57 are accommodated in a spring cover 56 attached to the wheel hub 5 so as to face each other in the expansion and contraction directions of the springs S1 and S2 (generally in the circumferential direction of the wheel hub 5). Each slider 57 has a hollow cylindrical shape with one surface opened and the other surface closed, and the openings of the sliders 57 face each other. The springs S1 and S2 are inserted between the sliders 57, and each slider 57 is urged in a direction away from each other by the springs S1 and S2, and is movable in the expansion and contraction directions of the springs S1 and S2. It has become. As a result, in the state shown in FIG. 4, each slider 57 is pushed outward by the urging force of the springs S <b> 1 and S <b> 2 and is in contact with each end of the spring cover 56.

  On the other hand, the rim base 6 has a pair of pressing portions 62 arranged so as to sandwich the pair of sliders 57 from the expansion and contraction directions of the springs S1 and S2. As shown in FIG. 5, the wheel hub 5 and the spring cover 56 are disengaged at both ends from the center portion of the slider 57 when viewed from the expansion / contraction direction of the springs S1, S2, and the center portion of each slider 57 is adjacent to the pressing portion. 62 is exposed. Further, as shown in FIG. 4, the distance between the pressing portions 62 is equal to the distance between the ends of the spring cover 56. As a result, in the state shown in FIG. 4, each pressing portion 62 is in contact with each slider 57 that is in contact with each end of the spring cover 56 at the center of the slider 57. In such a configuration, when a torque in the forward direction Df or the reverse direction Db (directions Df and Db are opposite to each other) is applied to the hand rim 4, the rim base 6 resists the elastic force of the springs S1 and S2. The wheel hub 5 is displaced in the torque application direction.

  FIG. 6 is a side view showing a state in which the rim base is displaced with respect to the wheel hub in accordance with the torque applied to the hand rim, and shows a state in which torque toward the reverse direction Db is applied. 6 will be added to FIGS. 3 to 5 and the description of the power assist mechanism 10 will be continued. When torque in the reverse direction Db is applied to the hand rim 4, the pressing portion 62 on the forward direction Df side of the pair of pressing portions 62 in the rim base 6 goes in the reverse direction Db with respect to the slider 57 with which it contacts. Give torque. When the torque applied from the pressing portion 62 on the forward direction Df side to the slider 57 exceeds the pressure applied by the springs S1 and S2, the pressing portion 62 on the forward direction Df side resists the elastic force of the springs S1 and S2. Then, the slider 57 is pushed in the reverse direction Db, and as a result, the hand rim 4 rotates in the reverse direction Db with respect to the wheel 3. The hand rim 4 is displaced with respect to the wheel 3 until the resultant force of the force applied to the slider 57 by the torque applied to the hand rim 4 and the elastic force of the springs S1 and S2 becomes zero. At this time, the amount of displacement of the hand rim 4 in the reverse direction Db with respect to the wheel 3 is in accordance with (proportional to) the magnitude of torque applied to the hand rim 4 by the occupant.

  Here, the case where torque toward the reverse direction Db is applied to the hand rim 4 is illustrated here, but also when the torque toward the forward direction Df is applied to the hand rim 4, the displacement direction of the hand rim 4 relative to the wheel 3 is also changed. A similar operation is performed except that the opposite is true. That is, the hand rim 4 is displaced in the forward direction Df with respect to the wheel 3 by a displacement amount corresponding to (proportional to) the magnitude of the torque applied to the hand rim 4 by the occupant.

  Further, as particularly shown in FIGS. 3 and 6, a configuration for limiting the displacement of the hand rim 4 with respect to the wheel 3 is provided. Specifically, an annular member 64 is fitted into an annular groove 63 formed in the rim base 6, and the annular member 64 is screwed to the rim base 6 by two bolts 65. Therefore, these bolts 65 are displaced in the rotational directions Df and Db with respect to the wheel 3 along with the hand rim 4. On the other hand, an arc-shaped groove 58 is formed on the wheel hub 5, and the boss portion 65 a of each bolt 65 screwed to the rim base 6 moves inside the groove 58. Therefore, the displacement of the hand rim 4 in the forward direction Df with respect to the wheel 3 is limited to a range until the boss 65a of the bolt 65 in the forward direction Df contacts the forward direction Df end of the groove 58. Similarly, the displacement of the hand rim 4 in the reverse direction Db with respect to the wheel 3 is limited to a range until the boss 65a of the bolt 65 in the reverse direction Db comes into contact with the end of the groove 58 in the reverse direction Db.

  Incidentally, the wheel hub 5 is formed with an arc-shaped through hole 59 provided inside the groove 58. Then, the engaging portion 70 a of the core member 70 is fitted into the through hole 59. The roles of the through hole 59 and the engaging portion 70a of the core member 70 will be described later with reference to FIG.

  As described above, the hand rim 4 is displaced with respect to the wheel 3 by an amount corresponding to the torque given by the occupant. Therefore, the power assist mechanism 10 measures the amount of displacement of the hand rim 4 with respect to the wheel 3 and detects the torque applied to the hand rim 4 based on the result. As a specific method for measuring the displacement amount of the hand rim 4, various methods such as a method using a potentiometer can be adopted. Here, a method using a magnetic sensor will be described.

  FIG. 7 is an enlarged front sectional view showing the periphery of a displacement detector provided in the power assist mechanism. FIG. 8 is a side view showing the relationship between the members constituting the displacement detector. In the displacement amount detector 7, an annular magnet 72 configured in an annular shape around the axle 30 is attached to the inside of the wheel hub 5 via a fixed plate 720. The annular magnet 72 has a configuration in which N poles 721 and S poles 722 are alternately arranged in a ring shape with a predetermined arrangement pitch Pm (in the example of FIG. 8, 18 magnetic poles 721 and 722 have an arrangement pitch of 20 degrees). Arranged in Pm). The annular magnet 72 rotates around the axle 30 along with the wheel hub 5.

  Furthermore, the displacement detector 7 is provided with an annular plate 73 configured in an annular shape centering on the axle 30. The annular plate 73 is a magnetic body (for example, iron that is a ferromagnetic body), and is adjacent to the annular magnet 72 from the inside in the axle direction Da. The annular plate 73 has a configuration in which a plurality of convex portions 731 protruding outward in the radial direction and opposed to the annular magnet 72 from the axle direction Da are annularly arranged at a predetermined arrangement pitch Pp (in the example of FIG. 8, 9 The convex portions 731 are arranged at an arrangement pitch Pp of 40 degrees). At this time, the arrangement pitch Pp of the projections 731 in the annular plate 73 is set to an even multiple (twice in FIG. 8) of the arrangement pitch Pm of the magnetic poles 721 and 722 in the annular magnet 72. The positional relationship of the convex portions 731 is configured to be the same for each convex portion 731. As a result, each convex portion 731 is similarly affected by the magnetic field created by the annular magnet 72 and magnetized to the same extent. Note that the annular plate 73 is disengaged from the annular magnet 72 in each recess 732 between the protrusions 731 adjacent in the circumferential direction.

  As shown in FIG. 7, the displacement detector 7 includes a core member 70 having a schematic configuration in which an annular plate 73 is held in a recess 732 by main bodies 70 a and 70 b. The core member 70 is configured by casting an annular plate 73 into main bodies 70a and 70b made of a nonmagnetic member (for example, resin), and an engaging portion 70a extending in the axle direction Da, and an engaging portion 70a. And a holding portion 70b extending from the inner end in the axle direction Da toward the radial center of the wheel 30. The engaging portion 70 a protrudes from the arc-shaped through hole 59 provided in the wheel hub 5 to the outside in the axle direction Da and engages with the engaging hole 64 a provided in the annular member 64. The engagement hole 64 a of the annular member 64 is configured to have the same diameter or a slightly larger diameter than the engagement portion 70 a of the core member 70. As described above, since the annular member 64 is fixed to the rim base 6 of the hand rim 4, when the hand rim 4 rotates, the engagement hole 64 a of the annular member 64 rotates with the core member 70 to be engaged. The annular plate 73 held by the main bodies 70a and 70b of the core member 70 also rotates. Incidentally, since the through hole 59 of the wheel hub 5 into which the engaging portion 70a of the core member 70 is fitted is formed in an arc shape having a length in the circumferential direction, the core member 70 is obstructed by the through hole 59. And can be rotated with the annular plate 73. Thus, the annular plate 73 is displaced with respect to the wheel 3 along with the hand rim 4 by the function of the engaging portion 70 a of the core member 70.

  The holding part 70b of the core member 70 is provided so as to straddle the annular magnet 72 in the radial direction of the wheel 3 inside the axle direction Da, and an annular plate 73 is cast into the holding part 70b. Thus, the annular plate 73 is held with a predetermined clearance with respect to the annular magnet 72 inside the axial direction Da of the annular magnet 72 by the function of the holding portion 70 b of the core member 70.

  Further, the displacement detector 7 includes a magnetic head 76 disposed on the opposite side of the annular magnet 72 (in other words, inside the axial direction Da of the annular plate 73) with the annular plate 73 interposed therebetween in the axle direction Da. The magnetic head 76 is fixed to the axle 30 and does not rotate. The magnetic head 76 includes a metal plate 761 (for example, made of iron) facing the annular plate 73, a magnetic detection element 762 facing the metal plate 761 from the inside in the axle direction Da, and a magnetic detection element 762 from the inside in the axle direction Da. And a backup member 763 facing each other. As described above, the magnetic head 76 has a configuration in which the magnetic detection element 762 is sandwiched between the metal plate 761 and the backup member 763 in the axle direction Da. The metal plate 761 functions as a magnetic collecting member that collects a magnetic field generated by the annular plate 73 magnetized by the annular magnet 72. On the other hand, the backup member 763 is made of metal (for example, iron) and functions to form a magnetic field path with the metal plate 761. The magnetic detection element 762 is configured by a magnetic sensor such as a Hall element, for example, detects a magnetic field from the metal plate 761 to the backup member 763, and outputs an electric signal (voltage signal).

  In the displacement detector 7 having the above-described configuration, an electric signal having a magnitude corresponding to the torque applied to the hand rim 4 is output from the magnetic detection element 762. That is, in the displacement amount detector 7, when the hand rim 4 is displaced relative to the wheel 3 by application of torque, the annular plate 73 attached to the hand rim 4 is displaced relative to the annular magnet 72 attached to the wheel 3. As a result, the degree of magnetization of the annular plate 73 by the annular magnet 72 changes according to the amount of displacement of the hand rim 4, and the electrical signal output from the magnetic detection element 762 changes. This point will be described in detail with reference to FIG. Here, FIG. 9 is a side view showing the relationship between the members constituting the displacement detector, and the same members as those shown in FIG. 8 are shown. However, FIG. 8 corresponds to a state in which no torque is applied to the hand rim 4, and FIG. 9 corresponds to a state in which a torque toward the reverse direction Db is applied to the hand rim 4.

  As shown in FIG. 8, in the state where no torque is applied to the hand rim 4, each convex portion 731 of the annular plate 73 is located at the boundary between the N pole 721 and the S pole 722. The magnetization of the convex portion 731 cancels out, and the annular plate 73 is not magnetized. Therefore, the magnetic detection element 762 outputs an electric signal having a voltage equal to the reference voltage. On the other hand, for example, as shown in FIG. 9, in the state in which the torque toward the reverse direction Db is applied to the hand rim 4, each convex portion 731 of the annular plate is N more than the boundary between the N pole 721 and the S pole 722. Since it shifts to the pole 721 side (reverse direction Db side), the annular plate 73 is more strongly affected by the N pole 721 than the S pole 722 and is magnetized to the N pole. Therefore, the magnetic detection element 762 outputs an electric signal having a voltage higher than the reference voltage. Specifically, the electrical signal has a magnitude corresponding to the amount of displacement of each convex portion 731 with respect to the boundary between the N pole 721 and the S pole 722. The amount of displacement is in accordance with the magnitude of torque applied to the hand rim 4 for the reason detailed above. As a result, the magnetic detection element 762 outputs an electric signal having a magnitude corresponding to the torque applied in the reverse direction Db.

  Here, the case where the torque toward the backward direction Db is applied to the hand rim 4 is illustrated here, but the case where the torque toward the forward direction Df is applied to the hand rim 4 also shows the electric signal from the magnetic detection element 762. A similar operation is performed except that the polarity is reversed (voltage smaller than the reference voltage). That is, the magnetic detection element 762 outputs an electric signal having a magnitude corresponding to the torque applied in the forward direction Db.

  By the way, when the displacement amount detector 7 as described above is used and the displacement of the hand rim 4 with respect to the wheel 3 has no temporal change, the displacement amount detector 7 responds to the displacement amount of the hand rim 4 with respect to the wheel 3. Continue to output electrical signals of a certain magnitude. However, the length of each of the plurality of convex portions 731 of the annular plate 73 varies due to manufacturing errors and the like, so that the displacement of the hand rim 4 with respect to the wheel 3 does not change with time, but the displacement amount detector The magnitude of the electrical signal output by 7 may fluctuate over time.

  That is, when the wheelchair 1 is traveling in a state in which the displacement of the hand rim 4 with respect to the wheel 3 is not changed with time, the wheel 3 and the hand rim 4 rotate around the axle 30 while maintaining a certain amount of displacement. . As a result, the annular magnet 72 on the wheel 3 side and the annular plate 73 of the hand rim 4 pass in front of the magnetic head 76 while maintaining a constant phase difference. At this time, since the phase difference between the annular magnet 72 and the annular plate 73 is constant, the annular plate 73 is magnetized by a certain amount corresponding to the phase difference. However, if the lengths of the plurality of convex portions 731 arranged in the circumferential direction in the annular plate 73 vary, the degree of magnetization of the annular plate varies depending on the position in the circumferential direction, and the electric signal output from the magnetic head 76 is changed. Sway in response (magnetic noise).

  Therefore, in the wheelchair 1, a plurality of (specifically, two) displacement amount detectors 7 are provided for each wheel 3 (FIG. 10). Here, FIG. 10 is a side view illustrating an arrangement mode of the displacement detector. In the drawing, a virtual straight line D extending in the vertical direction through the center of the axle 30 and a virtual straight line G extending in the horizontal direction through the center of the axle 30 are shown. Further, the angles E and F from the magnetic detection element 762 of each displacement amount detector 7 to the virtual straight line D are shown together with the intersection of the virtual straight lines D and G as the center. The angles E and F are both set to 70 degrees, and the angle (= E + F) between the two magnetic detection elements 762 is 140 degrees. In the configuration in which the displacement detector 7 is arranged in this way, since the arrangement pitch Pp of the convex portions 731 on the annular plate 73 is 40 degrees as described above, the convex portion 731 is directed to one of the magnetic detection elements 762 from the radial direction. At the timing of facing, the recess 732 faces the other magnetic detection element 762 from the radial direction. Therefore, when the period when the convex portion 731 passes through the position facing the magnetic detection element 762 from the radial direction is T731, the timing of detecting the magnetic field by the convex portion 731 facing from the radial direction is the same as that of both magnetic detection elements 762. Is shifted by a half cycle (= T731 / 2). As a result, the phase of the magnetic noise is generally reversed between the two magnetic detection elements 762. Therefore, the detection signal Sp in which the influence of the magnetic noise is suppressed can be generated by adding the electrical signals of both the magnetic detection elements 762.

  The power assist mechanism 10 controls the assist power applied to the wheels 3 by a controller 80 (FIG. 3) mounted on the built-in control board 8. FIG. 11 is a block diagram partially showing an electrical configuration of the wheelchair with auxiliary power. In FIG. 11, reference numeral 80 </ b> L is assigned to the controller 80 provided in the power assist mechanism 10 provided for the left wheel 3, and reference numeral 80 </ b> L is assigned to the controller 80 provided in the power assist mechanism 10 provided for the right wheel 3. 80R is attached. Further, in FIG. 11, in addition to the controllers 80 </ b> L and 80 </ b> R included in the power assist mechanism 10, a user I / F 87 provided in the wheelchair 1 and a control terminal device 100 that can be used for setting work described later for the wheelchair 1 are also illustrated. Yes.

  A left wheel controller 80 </ b> L is mounted on the control board 8 of the power assist mechanism 10 attached to the left wheel 3. The left wheel controller 80L includes a main control unit 81 that comprehensively manages control of auxiliary power, and a nonvolatile memory 82 that stores information necessary for control of auxiliary power. The main control unit 81 is a microcomputer including a CPU (Central Processing Unit) 810, a ROM (Read Only Memory) 811, and a memory 812.

  Further, the left wheel controller 80L has an I / F (interface) for transmitting and receiving signals to and from various hardware, specifically, a communication I / F 83, a motor output I / F 84, an encoder I / F85 and sensor I / F86. The communication I / F 83 performs communication with the right wheel controller 80L. The motor output I / F 84 is connected to the motor 91, and the main control unit 81 gives a drive signal Sd to the motor 91 via the motor output I / F 84. As a result, the motor 91 generates a torque corresponding to the drive signal Sd. The encoder I / F 85 is connected to an encoder 91a provided in the motor 91, and the main control unit 81 receives the output signal of the encoder 91a via the encoder I / F 85 and grasps the rotational position of the motor 91. .

  The sensor I / F 86 is connected to the displacement detector 7, and the main control unit 81 receives the voltage signal Sv output from the displacement detector 7 via the sensor I / F 86. The sensor I / F 86 is provided for each of the two displacement amount detectors 7, and the voltage signal Sv from each displacement amount detector 7 is input to the main control unit 81. Further, as described above, the main control unit 81 adds the voltage signals Sv to obtain the detection signal Sp indicating the displacement amount of the hand rim 4 relative to the wheel 3 in order to suppress the influence of magnetic noise. The main control unit 81 generates a drive signal Sd based on the detection signal Sp obtained for the left hand rim 4 and applies the drive signal Sd to the motor 91 of the power assist mechanism 10 provided on the left wheel 3. Thus, auxiliary power corresponding to the torque applied to the left hand rim 4 is applied to the left wheel 3.

  A right wheel controller 80 </ b> R is mounted on the control board 8 of the power assist mechanism 10 attached to the right wheel 3. The right wheel controller 80R basically has the same configuration as the left wheel controller 80L except that the right wheel controller 80R further includes a communication I / F 88 that performs communication with the control terminal device 100. That is, in the right wheel controller 80R, the main control unit 81 generates the drive signal Sd based on the detection signal Sp obtained for the right hand rim 4, and uses this drive signal Sd as the power assist provided in the right wheel 3. By giving to the motor 91 of the mechanism 10, auxiliary power corresponding to the torque applied to the right hand rim 4 is given to the right wheel 3.

  Furthermore, the main control unit 81 of the right wheel controller 80R is connected to a user I / F 87 provided in the wheelchair 1. That is, the user I / F 87 is controlled by the main control unit 81 of the right wheel controller 80R. Specifically, the main control unit 81 executes a calculation according to the input content of the user I / F 87 and displays the calculation result on the user I / F 87.

  The control terminal device 100 is a personal computer, a mobile phone, a smartphone, or the like that is configured by a main control unit 110 configured by a CPU or the like, a nonvolatile memory 120, or the like. The control terminal device 100 has a communication I / F 130 and can communicate with the right wheel controller 80R of the wheelchair 1 via the communication I / F 130. Furthermore, the control terminal device 100 has an operation input / output I / F 140 and an operation panel 150, and the main control unit 110 executes an operation according to the input content of the operation panel 150 and operates the operation result. Or display on the panel 150.

  Thus, in the wheelchair 1, when the torque T is applied to the hand rim 4, the hand rim 4 is displaced with respect to the wheel 3. Then, the controllers 80L and 80R generate a detection signal Sp having a magnitude corresponding to the displacement amount X of the hand rim 4 relative to the wheel 3, and further generate a drive signal Sd corresponding to the magnitude of the detection signal Sp. That is, based on the torque T applied to the hand rim 4, the displacement amount X, the detection signal Sp, and the drive signal Sd are generated in order. Next, details of signal generation executed in this way will be described.

  FIG. 12 is a diagram schematically showing how each signal is generated from the torque applied to the hand rim. In the figure, the function f1 illustrates the relationship between the torque T applied to the hand rim 4 and the displacement amount X of the hand rim 4, the function f2 illustrates the relationship between the displacement amount X of the hand rim 4 and the detection signal Sp, The function f3 exemplifies the relationship between the detection signal Sp and the drive signal Sd, and the function fm1 exemplifies the relationship between the torque T and the displacement 4 when the position of the neutral point varies depending on the operation direction of the hand rim 4. To do.

  As indicated by the function f1, the displacement amount X of the hand rim 4 with respect to the wheel 3 increases as the torque T applied to the hand rim 4 increases. That is, when the torque T in the forward direction Df (rightward on the horizontal axis) is applied, a displacement amount X corresponding to the magnitude of the torque T is generated in the forward direction Df (upward on the vertical axis), and in the backward direction Db. Is applied, a displacement amount X corresponding to the magnitude of the torque T is generated in the reverse direction Db (downward on the vertical axis). However, as described above, the springs S1 and S2 that transmit torque from the hand rim 4 to the wheel 3 are pressurized. Therefore, the displacement amount X of the hand rim T does not occur while the torque T is in the pressurizing region ΔT0 where the torque T does not exceed the pressurizing force of the springs S1, S2, and when the torque T deviates from the pressurizing region ΔT0, the torque T The amount of displacement X of the hand rim T increases in proportion to the increase in. The displacement of the hand rim 4 with respect to the wheel 3 is limited in both the forward direction Df and the reverse direction Db by the boss portion 65a and the groove 58 described above. Therefore, when the torque T reaches the value Tlf, the displacement amount X becomes constant at the value Xlf and does not change any more. Similarly, when the torque T reaches the value Tlb, the displacement amount X becomes constant at the value Xlb and does not change any more.

  As indicated by the function f2, the detection signal Sp changes in proportion to the torque T applied to the hand rim 4. That is, while there is no displacement amount X, a detection signal Sp having a voltage equal to the reference voltage Vr is output, and when a displacement amount X in the forward direction Df (upward in the vertical axis) occurs, the reference signal corresponds to the forward direction Df. When a detection signal Sp of a voltage higher than the voltage Vr (rightward in the horizontal axis) is generated and a displacement amount X in the backward direction Db (downward on the vertical axis) is generated, it is lower than the reference voltage Vr corresponding to the backward direction Db ( A voltage detection signal Sp is generated. At this time, the magnitude of the detection signal Sp given by the absolute value (= | V−Vr |) of the difference between the voltage value V of the detection signal Sp and the reference voltage Vr is proportional to the magnitude of the displacement amount X. In the graph showing the function f2, the voltage of the detection signal Sp when the displacement amount X is the maximum value Xlf in the forward direction Df is indicated as a value Vlf, and the displacement amount X is the maximum value Xlf in the reverse direction Db. The voltage of the detection signal Sp is indicated as the value Vlb.

  As shown by the function f3, the drive signal Sd increases as the detection signal Sp increases. That is, when the detection signal Sp corresponding to the forward direction Df (rightward on the horizontal axis) is generated, the drive signal Sd (having a polarity on the upper side of the vertical axis) corresponding to the magnitude of the detection signal Sp is generated. Auxiliary power toward the wheel 3 is given to the wheel 3. Further, when the detection signal Sp corresponding to the reverse direction Db (horizontal axis left direction) is generated, a drive signal Sd (having a polarity on the lower side of the vertical axis) corresponding to the magnitude of the detection signal Sp is generated, and the reverse direction Auxiliary power toward Db is applied to the wheel 3. However, a dead zone Z3 is provided in the function f3 (input / output characteristics) for converting the detection signal Sp into the drive signal Sd. The dead zone Z3 is provided from the voltage value Vzb to the voltage value Vzf, and is set to include the voltage values Vmf and Vmb of the detection signal Sp when the hand rim 4 is at a neutral point described later. Therefore, while the voltage value of the detection signal Sp is in the dead zone Z3, the drive signal Sd is not generated and the motor 91 does not generate auxiliary power. On the other hand, when the voltage value of the detection signal Sp deviates from the dead zone Z3, the magnitude of the drive signal Sd increases as the magnitude of the detection signal Sp increases, and the motor 91 has the magnitude of the detection signal Sp. The corresponding auxiliary power is generated.

  Thus, providing the dead zone Z3 in the output of the drive signal Sd with respect to the detection signal Sp is substantially equivalent to providing the dead zones Z2 and Z1 in the output of the drive signal Sd with respect to the displacement amount X or the output of the drive signal Sd with respect to the torque T. Are the same. That is, according to the conversion characteristics obtained by combining the functions f2 and f3 (hereinafter referred to as f3 · f2), the drive signal Sd is not generated while the displacement amount X is in the dead zone Z2 from the displacement amount Xzb to the displacement amount Xzf. The motor 91 does not generate auxiliary power. On the other hand, when the displacement amount X deviates from the dead zone Z2, the magnitude of the drive signal Sd increases as the displacement amount X increases, and the motor 91 assists according to the displacement amount X. Generate power. Here, the displacement amount Xzb is the displacement amount X when the voltage value of the detection signal Sp becomes Vzb, and the displacement amount Xzf is the displacement amount X when the voltage value of the detection signal Sp becomes Vzf. Further, according to the conversion characteristics obtained by combining the functions f1, f2, and f3, while the torque T is in the dead zone Z1 from the torque Tzb to the torque Tzf, the drive signal Sd is not generated and the motor 91 does not generate auxiliary power. On the other hand, when the torque T deviates from the dead zone Z3, the magnitude of the drive signal Sd increases with the magnitude of the torque T, and the motor 91 generates auxiliary power according to the magnitude of the torque T. To do. Here, the torque Tzb is the torque T when the value of the detection signal Sp is Vzb, and the torque Tzf is the torque T when the voltage value of the detection signal Sp is Vzf. Incidentally, as shown in the figure, the dead zone Z1 includes a pressurized region ΔT0.

  In such a wheelchair 1, when an occupant operates the hand rim 4 and applies a torque T to the hand rim 4, the hand rim 4 is displaced in the operation direction with respect to the wheel 3, and the torque T applied in the forward direction Df is the torque. When Tzf is exceeded or the absolute value of the torque T applied in the reverse direction Db exceeds the absolute value of the torque Tzb, auxiliary power for driving the wheels 3 in the operation direction is generated. When the occupant stops applying the torque T to the hand rim 4, the hand rim 4 returns to the neutral point by the elastic force of the springs S1 and S2, so that the auxiliary power applied to the wheels 3 disappears.

  However, since a frictional force acts on the hand rim 4, the hand rim 4 that returns by the elastic force after being displaced in the operation direction stops at a position where the resultant force including the elastic force and the frictional force becomes zero. As a result, the stationary position of the hand rim 4, that is, the neutral point, tends to be biased in the direction (operation direction) in which the hand rim 4 was displaced before the hand rim 4 was stationary. Moreover, since the hand rim 4 of the wheelchair 3 is operated in both the forward direction Df and the reverse direction Db by the occupant, the neutral points Xmf and Xmb differ between the forward direction Df and the reverse direction Db (Xmb <0). <Xmf), the output of the displacement amount X with respect to the torque T may be as shown in the function fm1. On the other hand, the dead zone Z2 of the conversion characteristics f3 and f2 for converting the displacement amount X into the drive signal Sd is set so as to include both the neutral points Xmf and Xmb (Xzb <Xmb <0 <Xmf <Xzf). ).

  In FIG. 12, torque Tmf is a torque resulting from the elastic force of the springs S1 and S2 when the hand rim 4 is at the neutral point Xmf, and antagonizes with the frictional force when the hand rim 4 is stationary at the neutral point Xmf. doing. The torque Tmb is a torque caused by the elastic force of the springs S1 and S2 when the hand rim 4 is at the neutral point Xmb, and antagonizes the frictional force when the hand rim 4 is stationary at the neutral point Xmb.

  For the wheelchair as described above, the gain Gs of the conversion characteristic (function f3) for converting the detection signal Sp into the drive signal Sd and the dead zone Z3 are set in advance by the operator. Next, an example of these setting operations for the wheelchair 1 will be described. FIG. 13 is a flowchart illustrating an example of setting work performed on a wheelchair. FIG. 14 is a flowchart illustrating an example of gain adjustment executed in the flowchart of FIG. FIG. 15 is a diagram showing an example of dead zone setting executed in the flowchart of FIG.

  As shown in FIG. 13, the operator performs dead zone setting (step S200) after performing gain adjustment (step S100). In the gain adjustment shown in FIG. 14, steps S101 to S106 are executed in order for each of the right wheel 3 and the left wheel 3 (for example, in the order of the right wheel and the left wheel). That is, in step S101, the operator displaces the hand rim 4 with respect to the wheel 3 up to the front end Xlf of the variable range (Xlb to Xlf). Then, when the operator inputs through the user I / F 87 that step S101 is completed, the main control unit 81 of the right wheel controller 80R acquires the voltage value Vlf of the detection signal Sp (step S102). Subsequently, in step S103, the operator displaces the hand rim 4 with respect to the wheel 3 to the rear end Xlb of the variable range (Xlb to Xlf). Then, when the operator inputs through the user I / F 87 that step S103 is completed, the main control unit 81 of the right wheel controller 80R acquires the voltage value Vlb of the detection signal Sp (step S104).

The main control unit 81 of the right wheel controller 80R transmits the voltage values Vlf and Vlb of the detection signal Sp to the control terminal device 100 via the communication I / Fs 88 and 130. Then, the control terminal device 100 uses the arithmetic function of the main control unit 110 to calculate the following arithmetic expression: Gs = Vtyp / (Vlf−Vlb)
The gain Gs is calculated according to (Step S105). Here, the voltage Vtyp is a normalized voltage stored in advance in the nonvolatile memory 82 of the right wheel controller 82. Incidentally, although the case where the control terminal device 100 performs the calculation of step S105 is shown here, when the setting of the wheelchair 1 is performed without using the control terminal device 100, the right wheel controller 80R performs the operation of step S105. An operation may be performed. In step S106, the gain Gs obtained in step S105 is stored in the nonvolatile memory 82. Thus, the setting of the gain Gs of the conversion characteristic (function f3) for converting the detection signal Sp into the drive signal Sd is completed for the right wheel 3.

  Subsequently, steps S101 to S106 are similarly executed for the left wheel 3, and the setting of the gain Gs of the conversion characteristic (function f3) for converting the detection signal Sp into the drive signal Sd is completed for the left wheel 3. When the setting of the gain Gs for both wheels 3 is completed (“YES” in step S107), the gain adjustment shown in FIG. 14 is completed, and the dead zone setting shown in FIG. 15 is performed.

  In the dead zone setting shown in FIG. 15, steps S201 to S211 are executed in order for each of the right wheel 3 and the left wheel 3 (for example, in the order of the right wheel and the left wheel). That is, in step S201, the operator displaces the right hand rim 4 in the forward direction Df with respect to the wheel 3 by, for example, the displacement amount Xlf. In subsequent step S202, the operator returns the hand rim 4 to the reverse direction Db by the elastic force of the springs S1 and S2. At this time, the operator can execute step S202 while applying torque against the elastic force of the springs S1 and S2 to the hand rim 4. In other words, the operator makes the hand rim 4 quasi-static by the elastic force of the springs S1 and S2 while maintaining a state where the resultant torque including the torque applied to the hand rim 4 and the elastic force of the springs S1 and S2 becomes zero. It is possible to return to the reverse direction Db. This step S202 is continued until the hand rim 4 stops in a state where the operator does not apply torque to the hand rim 4 (step S203). The displacement amount Xmf of the hand rim 4 when stationary in this way corresponds to the position of the neutral point in the forward direction Df of the hand rim 4. Then, when the operator inputs through the user I / F 87 that the right hand rim 4 is stationary, the main control unit 81 of the right wheel controller 80R acquires the voltage value Vmf of the detection signal Sp (step S204).

  Subsequently, in step S205, the operator displaces the right hand rim 4 in the reverse direction Db with respect to the wheel 3 by, for example, a displacement amount Xlb. In subsequent step S206, the operator returns the hand rim 4 to the forward direction Df by the elastic force of the springs S1, S2. Also at this time, the operator can return the hand rim 4 to the forward direction Df quasi-statically by the elastic force of the springs S1, S2. This step S205 is continued until the hand rim 4 stops in a state where the operator does not apply torque to the hand rim 4 (step S207). The displacement amount Xmb of the hand rim 4 when stationary in this way corresponds to the position of the neutral point in the reverse direction Db of the hand rim 4. Then, when the operator inputs through the user I / F 87 that the right hand rim 4 is stationary, the main control unit 81 of the right wheel controller 80R acquires the voltage value Vmb of the detection signal Sp (step S208).

The main control unit 81 of the right wheel controller 80R transmits the voltage values Vmf and Vmb of the detection signal Sp to the control terminal device 100 via the communication I / Fs 88 and 130. Then, the control terminal device 100 uses the calculation function of the main control unit 110 to calculate the following calculation formula: V0 = (Vmf + Vmb) / 2
Then, the midpoint potential V0 is calculated (step S209). Incidentally, although the case where the control terminal device 100 performs the calculation of step S209 is shown here, when the setting of the wheelchair 1 is performed without using the control terminal device 100, the right wheel controller 80R performs the operation of step S209. An operation may be performed. In step S210, the midpoint potential V0 obtained in step S209 is stored in the nonvolatile memory 82. In step S211, the dead zone Z3 is set and stored in the nonvolatile memory 82 such that the dead zone Z3 includes the voltage values Vmf and Vmb while the center of the dead zone Z3 coincides with the midpoint potential V0. Thus, the setting of the dead zone Z3 of the conversion characteristic (function f3) for converting the detection signal Sp into the drive signal Sd is completed for the right wheel 3. Accordingly, in the conversion characteristics f3 and f2 for converting the displacement amount X into the drive signal Sd, the center of the dead zone Z2 coincides with the center of the neutral points Xzf and Xzb, and the dead zone Z2 includes the neutral points Xzf and Xzb. A dead zone Z2 is set for the right wheel 3.

  Subsequently, steps S201 to S211 are similarly executed for the left wheel 3, and the setting of the dead zone Z3 of the conversion characteristic (function f3) for converting the detection signal Sp into the drive signal Sd is completed for the left wheel 3. Accordingly, in the conversion characteristics f3 and f2 for converting the displacement amount X into the drive signal Sd, the center of the dead zone Z2 coincides with the center of the neutral points Xzf and Xzb, and the dead zone Z2 includes the neutral points Xzf and Xzb. A dead zone Z2 is set for the left wheel 3.

  As described above, in this embodiment, the hand rim 4 that is rotatable with respect to the wheel 3 in both the forward direction Df and the reverse direction Db is provided, and the hand rim is provided between the wheel 3 and the hand rim 4. 4 are connected by springs S1 and S2 which are deformed according to the torque T applied to them. Therefore, the hand rim 4 is displaced with respect to the wheel 3 by a displacement amount X corresponding to the torque T applied to the hand rim 4. Furthermore, the wheelchair 1 includes controllers 80L and 80R that convert the displacement amount X of the hand rim 4 with respect to the wheel 3 into a drive signal Sd, and a motor 91 that gives auxiliary power to the wheel 3 according to the drive signal Sd. As a result, auxiliary power corresponding to the torque T applied to the hand rim 4 is given to the wheels.

  In this embodiment, the conversion characteristics f3 and f2 for converting the displacement amount X of the hand rim 4 into the drive signal Sd have a dead zone Z2 with respect to the displacement amount X. Therefore, even when the occupant operates the hand rim 4, no auxiliary power is generated during the period in which the displacement amount X of the hand rim 4 is in the range of the dead zone Z2. On the other hand, when the displacement amount X of the hand rim 4 reaches the end of the dead zone Z2, the auxiliary power starts to work. After the displacement amount X of the hand rim 4 comes out of the dead zone Z2, the auxiliary power corresponding to this displacement amount X is applied to the wheel 3. Given to.

  In this embodiment, the dead zone Z2 of the conversion characteristics f3 and f2 is set based on the neutral points Xmf and Xmb of the hand rim 4. Specifically, the hand rim 4 displaced in the forward direction Df with respect to the wheel 3 is displaced in the backward direction Db with respect to the wheel 3 and the neutral point Xmf where the hand rim 4 returns to the backward direction Db by the elastic force of the springs S1 and S2. The dead zone Z2 with respect to the displacement amount X of the conversion characteristics f3 and f2 is set so that the hand rim 4 includes the neutral point Xmb that returns to the forward direction Df and stops by the elastic force of the springs S1 and S2. In this way, by including the neutral points Xmf and Xmb whose positions differ depending on the operation direction in the dead zone Z2 of the conversion characteristics f3 and f2, the influence on the operation feeling that the positions of the neutral points Xmf and Xmb differ depending on the operation direction is mitigated. Thus, it is possible to achieve a good driving feeling.

  In order to specifically describe an example in which the influence on the operational feeling is reduced, for example, the neutral points Xmf and Xmb are shifted from the dead zone Z2, and one neutral point, for example, the neutral point Xmf is the dead zone Z2. Consider the case where Xmf> Xzf. When the wheel 3 is moved forward from the state where the hand rim 4 is at the neutral point Xmf, if an operating force is applied to the hand rim 4, the wheel 3 is driven only by the operating torque T until the torque Tzf is exceeded. It acts on the wheel 3 additionally. Since Xmf> Xzf, even if the operation torque T exceeding the torque Tzf that causes both the operation torque T and the auxiliary power to act on the wheel 3 is applied to the hand rim 4, the friction force (the hand rim 4 is applied to the torque Tmf). When exceeding the torque added by the torque caused by the friction force acting on the hand rim 4 from the wheel 3 side when it is stationary at the neutral point Xmf against the elastic force of the springs S1 and S2 The displacement amount X of the hand rim 4 with respect to the wheel 3 remains unchanged from the neutral point Xmf. For this reason, the passenger | crew who advances the wheel 3 from the state in which the hand rim 4 exists in the neutral point Xmf exists in the tendency which feels the operation feeling of the wheel 3 hard.

  On the other hand, when the wheel 3 is advanced from the state where the hand rim 4 is at the neutral point Xmb, the friction is assisted by the elastic force of the springs S1 and S2 regardless of the difference in size between Xmf and Xzf. By applying a small torque T that overcomes the force, the displacement amount X of the hand rim 4 with respect to the wheel 3 changes from Xmb to zero. When a further increasing operation torque T that overcomes the elastic force and frictional force of the springs S1 and S2 is further applied to the hand rim 4, the displacement amount X of the hand rim 4 relative to the wheel 3 increases from zero. The displacement of the hand rim 4 with respect to the wheel 3 as a matter of course, as long as the operating torque T exceeds the torque Tzf that both the operating torque T and the auxiliary power act on the wheel 3, depending on the operating torque T gradually increasing from a considerably small value. The quantity X increases gradually. As a result, an occupant who advances the wheel 3 from a state in which the hand rim 4 is at the neutral point Xmb tends to feel the operational feeling of the wheel 3 softly.

  As described above, when at least one of the neutral points Xmf and Xmb is out of the dead zone Z2, there is a great difference in the feeling of operation by the occupant depending on whether the hand rim 4 is at the neutral point Xmf or Xmb at the start of the operation. There was a fear. On the other hand, in this embodiment, the dead zone Z2 is set so as to include the neutral points Xmf and Xmb, and Xmf <Xzf. Therefore, unlike the above example, even if the hand rim 4 is at the neutral point Xmf at the start of operation, torque T smaller than torque Tzf (operation torque T exceeding torque obtained by adding torque caused by frictional force to torque Tmf). The hand rim 4 is displaced with respect to the wheel 3 from the neutral point Xmf. When a torque T exceeding the torque Tzf is applied to the hand rim 4, the displacement amount X of the hand rim 4 with respect to the wheel 3 exceeds Xzf and auxiliary power acts on the wheel 3. That is, as compared with the above example, the hardness of the operation feeling when the wheel 3 is advanced from the state where the hand rim 4 is at the neutral point Xmf is alleviated.

  Such an advantage can be said to be particularly suitable for the wheelchair 1 provided with the wheels 3 on the left and right respectively. To specifically explain this point, consider a case where the neutral point Xmf deviates from the dead zone Z2 and Xmf> Xzf as in the above example on both the left and right sides. At this time, for example, if the wheel 3 is moved forward from the state in which the left hand rim 4 is at the neutral point Xmf and the right hand rim 4 is at the neutral point Xnb, the occupant feels that the operation feeling of the left wheel 3 is hard. When the torque exceeding the torque Tzf is applied to the hand rim 4 on the left side, the displacement X of the hand rim 4 relative to the left wheel 3 does not change from the neutral point Xmf, and the auxiliary power is not changed. 3 will be affected. As a result, the operability of the occupant differs greatly between the left and right wheels 3, and the operability of the wheelchair 1 may be reduced. On the other hand, in this embodiment, the dead zone Z2 is set so as to include the neutral points Xmf and Xmb, and Xmf <Xzf. Therefore, the difference in operational feeling between the left and right wheels 3 can be reduced, and the operability of the wheelchair 1 can be improved.

  From the viewpoint of improving driving sensation, it is preferable to stop the wheelchair 1 by stopping generation of auxiliary power when the occupant releases his hand from the hand rim 4. On the other hand, according to the present embodiment in which the dead zone Z2 is set so as to include the neutral points Xmf and Xmb, the occupant releases his hand from the hand rim 4, and the hand rim 4 is at the neutral point Xmf or the neutral point Xmb. No auxiliary power is generated. That is, after the wheelchair 1 stops, there is an advantage that the wheelchair 1 continues to stop even if the passenger releases his hand from the hand rim 4.

  In particular, the wheelchair setting method (dead zone setting in FIG. 15) shown in the present embodiment has the advantage that the dead zone Z2 can be set more simply and appropriately. That is, the adjustment of the dead zone Z2 with respect to the neutral points Xmf and Xmb of the hand rim 4 may be performed by adjusting the position of the magnetic detection element 762 with respect to the hand rim 4, for example. However, it is difficult to adjust the position of the magnetic detection element 762 with high accuracy, and it is not easy to appropriately adjust the dead zone Z2 with respect to the neutral points Xmf and Xmb. In contrast, in the present embodiment, the dead zone Z2 is adjusted with respect to the neutral points Xmf and Xmb of the hand rim 4 by adjusting the dead zone Z2 instead of adjusting the position of the magnetic detection element 762. Such a configuration can adjust the dead zone Z2 with respect to the neutral points Xmf and Xmb of the hand rim 4 only by rewriting information on the dead zone Z2 stored in the controllers 80L and 80R. Accordingly, the dead zone Z2 can be set more simply and appropriately.

  The conversion characteristics f3 and f2 are set so that the center of the dead zone Z2 of the conversion characteristics f3 and f2 coincides with the centers of the neutral points Xmf and Xmb. In such a configuration, the displacement of the hand rim 4 from the neutral point Xmf to the end Xzf in the forward direction Df of the dead zone Z2 and the hand rim from the neutral point Xmb to the end Xzb in the reverse direction Db of the dead zone Z2 The amount of displacement of 4 is equal. Accordingly, when the occupant operates the hand rim 4 in the forward direction Df from the neutral point Xmf and when the hand rim 4 is operated in the reverse direction Db from the neutral point Xmb, the amount of operation of the hand rim 4 until the auxiliary power starts to work is large. Will be equal. As a result, it is possible to effectively suppress the influence of the position of the neutral points Xmb and Xmf on the operation feeling depending on the operation direction, and to realize a very good driving feeling.

  In particular, in the wheelchair setting method shown in this embodiment (dead zone setting in FIG. 15), the dead zone Z2 is adjusted with respect to the neutral points Xmf and Xmb by adjusting the dead zone Z2 instead of adjusting the position of the magnetic detection element 762. Z2 is adjusted. Therefore, the center of the dead zone Z2 can be easily and reliably aligned with the center of the neutral points Xmf and Xmb of the hand rim 4 simply by rewriting the information regarding the dead zone Z2 stored in the controllers 80L and 80R.

  In the present embodiment, the gain Gs that the main control unit 81 of the controllers 80L and 80R converts the detection signal Sp into the drive signal Sd based on the gain that the displacement detector 7 converts the displacement amount X into the detection signal Sp. Has been adjusted. Therefore, even if the gain of the displacement detector 7 attached to the wheelchair 1 varies at each detector 7 at the manufacturing site of the wheelchair 1 or the like, the wheelchair 1 that outputs a stable drive signal Sd can be obtained.

  Thus, in this embodiment, the wheelchair 1 corresponds to an example of the “wheelchair with auxiliary power” of the present invention, the wheel 3 corresponds to an example of the “wheel” of the present invention, and the springs S1 and S2 correspond to the present invention. It corresponds to an example of “elastic member”, controllers 80L and 80R correspond to an example of “control unit” of the present invention, displacement amount detector 7 corresponds to an example of “detector” of the present invention, and motor 91 The conversion characteristics f3 and f2 correspond to an example of the "conversion characteristics" of the present invention, and the neutral points Xmf and Xmb correspond to the "first neutral point" or the "first neutral point" of the present invention. The forward direction Df or the reverse direction Db corresponds to an example of the “first direction” or the “second direction” of the present invention, and a circuit (such as a CPU 810) that constitutes the main control unit 81. Corresponds to an example of the “control circuit” of the present invention.

  The present invention is not limited to the above-described embodiment, and various modifications can be made to the above-described one without departing from the spirit of the present invention. Therefore, for example, the wheelchair 1 may be configured to further include an abnormality detection function described below. FIG. 16 is a flowchart illustrating an example of an operation performed by a wheelchair having an abnormality detection function. The flowchart can be executed, for example, after the wheelchair setting shown in FIG. 13 is completed.

In step S301, the front output range Rf (detection signal output) is the difference between the voltage Vlf of the detection signal Sp and the midpoint voltage V0 when the hand rim 4 is displaced to the end Xlf in the forward direction Df of the variable range Xlb to Xlf. The absolute value (= | Vlf−V0 |) of the range is obtained in the main control unit 81. In the subsequent step S302, the rear output range Rb (detection) which is the difference between the voltage Vlb of the detection signal Sp and the midpoint voltage V0 when the hand rim 4 is displaced to the end Xlb in the reverse direction Db of the variable range Xlb to Xlf. The absolute value (= | Vlb−V0 |) of the signal output range is obtained in the main control unit 81. Then, the main control unit 81 compares the following condition Rf ≦ Rth with the predetermined threshold value Rth.
Rb ≦ Rth
If it is determined that at least one of the above is satisfied (in the case of “YES” in step S303), it is determined that an abnormality has occurred (step S304), and that is notified via the user I / F 87 ( Step S305), the flowchart of FIG. 16 ends. If it is determined that there is no abnormality (in the case of “NO” in step S303), the flowchart of FIG. Note that the flowchart of FIG. 16 is executed for each of the right wheel 3 and the left wheel 3.

  In such a configuration, when the absolute values of the detection signal output ranges Rf and Rb are equal to or less than the threshold value Rth, it is determined that an abnormality has occurred. Therefore, if the detection signal output ranges Rf and Rb are not sufficiently secured, it is determined that there is an abnormality, and therefore maintenance for securing the detection signal output ranges Rf and Rb can be performed as necessary. Is preferred.

  Furthermore, when the main control unit 81 determines that an abnormality has occurred, a user I / F (notification unit) for notifying the occurrence of an abnormality is provided. Therefore, it is possible to notify the occupant of the wheelchair, an assistant, or an operator who sets the wheelchair, etc., and to prompt the execution of necessary maintenance.

  FIG. 17 is a flowchart illustrating another example of an operation performed by a wheelchair having an abnormality detection function. The flowchart can be executed, for example, after the wheelchair setting shown in FIG. 13 is completed. In step S401, the right wheel controller 80R obtains its own front output range Rf1 and rear output range Rb1. Thus, the respective output ranges Rf1 and Rb1 for the right wheel 3 are acquired. In step S402, the right wheel controller 80R receives the front output range Rf2 and the rear output range Rb2 of the other party (that is, the left wheel controller 80L) from the left wheel controller 80L via the communication I / F 83. Thus, the respective output ranges Rf2 and Rb2 for the left wheel 3 are acquired.

In the subsequent step S403, the right wheel controller 80R, for the left wheel 3 and the right wheel 3, between the front output range difference ΔRf (= | Rf1-Rf2 |) and the rear output range difference ΔRb (= | Rb1-Rb2 | ) And ask. Then, the main control unit 81 of the right wheel controller 80R compares the following condition ΔRf ≧ ΔRth with the predetermined threshold value ΔRth.
ΔRb ≧ ΔRth
If it is determined that at least one of the above is satisfied (in the case of “YES” in step S404), it is determined that an abnormality has occurred (step S405), and the fact is notified via the user I / F 87 (step S405). S406), the flowchart of FIG. 17 ends. If it is determined that there is no abnormality (“NO” in step S404), the flowchart of FIG.

  In such a configuration, when the detection signal output ranges Rf1 and Rb1 for the right wheel 3 are greatly different from the detection signal output ranges Rf2 and Rb2 for the left wheel 3, it is determined that there is an abnormality. Therefore, it is preferable that maintenance for aligning the detection signal output ranges Rf1, Rb1, Rf2, and Rb2 between the right wheel 3 and the left wheel 3 can be performed as necessary.

  Furthermore, when the main control unit 81 determines that an abnormality has occurred, a user I / F (notification unit) for notifying the occurrence of an abnormality is provided. Therefore, it is possible to notify the occupant of the wheelchair, an assistant, or an operator who sets the wheelchair, etc., and to prompt the execution of necessary maintenance.

  In addition to the above-described detection function shown in FIGS. 16 and 17, various modifications can be made to the above embodiment. As a specific example, in the above-described embodiment, in the dead zone setting shown in FIG. 15, the step of returning the hand rim 4 by the elastic force of the springs S1 and S2 (steps S202 and S206) returns the hand rim 4 to quasi-static. Executed in. However, the specific method for returning the hand rim 4 in these steps (steps S202 and S206) is not limited to this. Therefore, the hand rim 4 may be returned by a method other than the quasi-static method.

  Further, in the above embodiment, in the dead zone setting shown in FIG. 15, the step (S201, S205) of displacing the hand rim 4 is executed by displacing the hand rim 4 by the displacement amounts Xlf, Xlb. However, the displacement amount of the hand rim 4 in these steps (S201, S205) is not limited to these.

  In the above embodiment, the center of the dead zone Z3 coincides with the midpoint potential V0, and the center of the dead zone Z2 coincides with the centers of the neutral points Xmf and Xmb. However, even if these are deviated, a good driving feeling can be realized by setting the dead zone Z2 so as to include the neutral points Xmf and Xmb.

  In the above embodiment, the “elastic member” is constituted by the two springs S1 and S2. However, the specific configuration aspect of the “elastic member” is not limited to the above-described aspect, and it is sufficient that the elastic member is configured to exhibit an elastic force. Therefore, for example, the “elastic member” may be composed of a single spring or a member other than the spring (for example, rubber).

  In the above embodiment, the springs S1 and S2 are pressurized. However, it is not always necessary to pressurize the springs S1 and S2.

DESCRIPTION OF SYMBOLS 1 ... Wheelchair 3 ... Wheel 4 ... Hand rim 5 ... Wheel hub 6 ... Rim base 7 ... Displacement amount detector 80L, 80R ... Controller (control part)
91: Motor (drive source)
S1, S2 ... Spring (elastic member)
Xmb, Xmf ... neutral point Z1, Z2, Z3 ... dead zone

Claims (9)

With rotatable wheels,
A hand rim that is rotatable with respect to the wheel in both directions of a first direction and a second direction opposite to the first direction;
An elastic member that connects between the wheel and the hand rim and deforms according to the torque applied to the hand rim;
A control unit that converts a displacement amount of the hand rim with respect to the wheel into a drive signal;
A drive source for providing auxiliary power to the wheel according to the drive signal;
The control unit converts the displacement amount into the drive signal according to a predetermined conversion characteristic,
The hand rim displaced in the first direction relative to the wheel is displaced in the second direction relative to the wheel, and a first neutral point where the hand rim returns to the second direction and is stationary by the elastic force of the elastic member. A wheelchair with auxiliary power in which a dead zone for the displacement amount of the conversion characteristic is set so that the hand rim includes a second neutral point that returns to the first direction and stops by the elastic force of the elastic member.   The wheelchair with auxiliary power according to claim 1, wherein the conversion characteristic is set so that a center of the dead zone of the conversion characteristic coincides with a center of the first neutral point and the second neutral point.   The said control part has a detector which detects the said displacement amount and converts it into a detection signal, and a control circuit which converts the said detection signal which the said detector outputs into the said drive signal. Wheelchair with auxiliary power.   The wheelchair with auxiliary power according to claim 3, wherein a gain by which the conversion circuit converts the detection signal into the drive signal is adjusted based on a gain at which the detector converts the displacement amount into the detection signal. The range in which the hand rim is displaced with respect to the wheel is limited to a predetermined variable range,
The control unit is configured to detect the detection signal when the hand rim is positioned at an end of the variable range in the first direction, and the control signal when the hand rim is positioned at the center between the first neutral point and the second neutral point. The wheelchair with auxiliary power according to claim 3 or 4, wherein when the absolute value of the detection signal output range, which is a difference from the detection signal, is equal to or less than a threshold value, it is determined that an abnormality has occurred. The wheelchair with auxiliary power according to claim 3 or 4, comprising a pair of the wheels, and the hand rim, the elastic member, the control unit, and the drive source corresponding to each of the wheels.
The range in which the hand rim is displaced with respect to the wheel is limited to a predetermined variable range,
The control unit is configured to detect the detection signal when the hand rim is positioned at an end of the variable range in the first direction, and the control signal when the hand rim is positioned at the center between the first neutral point and the second neutral point. The difference between the detection signal and the detection signal output range obtained as a detection signal output range as the detection signal output range is the absolute difference between the detection signal output range obtained for one of the wheels and the detection signal output range obtained for the other wheel. A wheelchair with auxiliary power that determines that an abnormality has occurred if the value is greater than or equal to a threshold value. A communication unit that performs communication between the control unit of the one wheel and the control unit of the other wheel;
The control unit corresponding to the one wheel obtains the detection signal output range for the one wheel,
The control unit corresponding to the other wheel obtains the detection signal output range for the other wheel,
The control unit corresponding to the one wheel includes the detection signal output range for the other wheel received from the control unit corresponding to the other wheel via the communication unit, and the one obtained by the control unit. The wheelchair with auxiliary power according to claim 6, wherein the presence / absence of the abnormality is determined from the detection signal output range of the wheel.   The wheelchair with auxiliary power according to any one of claims 5 to 7, further comprising a notification unit that notifies the occurrence of the abnormality when the control unit determines that the abnormality has occurred. A rotatable wheel, a hand rim rotatable relative to the wheel in a first direction and a second direction opposite to the first direction, connected between the wheel and the hand rim and applied to the hand rim. A wheelchair with auxiliary power provided with an elastic member that deforms according to the torque, a control unit that converts a displacement amount of the hand rim with respect to the wheel into a drive signal, and a drive source that supplies auxiliary power according to the drive signal to the wheel In contrast, in the setting method of the wheelchair with auxiliary power for setting the conversion characteristic of the control unit that converts the displacement amount into the drive signal,
Obtaining a first neutral point where the hand rim displaced in the first direction relative to the wheel returns to the second direction by the elastic force of the elastic member and is stationary;
Obtaining a second neutral point where the hand rim displaced in the second direction with respect to the wheel returns to the first direction by the elastic force of the elastic member and is stationary;
A method for setting a wheelchair with auxiliary power, comprising: setting a dead zone for the displacement of the conversion characteristic so as to include the first neutral point and the second neutral point.

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