(Machine Transtation by Espacenet)
`
`Bibliographic data
`
`
`
`
`
`
`JP2009190443 (A)
`
`- VEHICLE WITH ASSIST POWER
`
`inventor(s):
`
`KAMIYA SATOSHI
`
`Appicant(s):
`YAMAHA MOTOR CO LTD
`
`Classification:
`
`- iniernational:
`
`B62ZMS6/45
`
`~ cooperative:
`
`B62M6/45 (EP)
`
`Application number:
`
`JP2Z0080030399 20080212
`
`Priory number(s):
`JP20080030399 20080212
`
`Aliso published as:
`
`JP5107742 (B2) WO2009101990 (At}
`
`Abstract
`
`Abstract of
`
`JP2009190443 (A}
`
`PROBLEM TO BE SOLVED: To correcily set the zero-point of a manual power detecior
`
`without allowing an occupant to feel a sense of incongruily afier a power supply is turned
`
`an during traveling. ‘SOLUTION: This vehicle with an assist power comprises the manual
`
`power detector (orque sensor 16) and a zero-point setter 27 for setting zero-point set
`
`values for the manual power detector. The vehicle comprises an auxiliary drive force
`
`generating device 21 for generating an auxiliary drive force according to the magnitude
`
`of a manual power drive force. The zero-point setier 27 comprises aninitial set part 24,
`
`

`

`a minimum value detection part 25, and a zero-point set value correction part 26. When
`
`actually-measured values are varied within a predetermined time after the power supply
`
`is turned on, the initial set part 24 sets one of the maximum value of the actually
`
`measured values and the maximum value of the predetermined zero-paint set values at
`
`the zero-point set value. The minimum value detection part 25 detects the minimum
`
`value of the actually measured values of the manual force detector. The zero-point set
`
`value correction part 26 reduces a repeated zero-point set value to the minimum value
`
`by
`
`substraction
`
`for
`
`each
`
`predetermined
`
`standby
`
`period.
`
`;jCOPYRIGHT:
`
`(C2008 JPOSINEIT
`
`Claims
`
`Notice
`
`This transiation is machine-generaied.
`
`Ht cannot be guaranteed that # is intelligible,
`
`accurate, complete,
`
`reliable or fit for specific purposes. Critical decisions, such as
`
`commercially relevant ar financial decisions, should not be based on machine-transiation
`
`output.
`
`CLAIMS JP2009190443A
`
`A human-powered detecior for detecting the magnitude of human-powered driving force
`
`consisting of occupant power, and a O-point setting device that sets a O-point settling
`
`value corresponding to the detection value of this human-powered detector in a no-load
`
`state afier the power is turned on.
`
`, Auxiliary power equipped with an auxiliary driving
`
`force generator that generates an auxiliary driving force of a magnitude corresponding
`
`fo the magnitude of the true human-powered driving force, which is the difference
`
`between the 0-point set value and ihe measured value of the human-powered detecior.
`
`inthe vehicle with a vehicle, when the measured value fluctuates within a predetermined
`
`ume from the time when the power is turned on, the Q-point setting Gevice is either the
`
`maximum value of the measured value or the maximum value of the predetermined 0-
`
`paint set value. By a predetermined reduction procedure until the 0 point setting value
`
`becomes equai to the minimum vaiue, the initial setting unit that sets the 0 point setting
`
`value, the minimum value detection unit that detects the minimumvalue of the measured
`
`value after the power is turned on, and the zero point setiing value. [tis provided with a
`
`0-poini set value correction unil ihat repeatedly decreases, and the reduction procedure
`
`

`

`reduces the 0-point set value by subtraction each time a predetermined wailing period
`
`ends, so that the O-point set value is gradually decreased. Auxillary powered vehicle
`
`characterized by being defined.
`
`in the vehicie with aundiary power according to claim 1, the end time of the standby
`
`period is the mileage of the vehicle, the running time of the vehicle, ihe number of
`
`rotations of the rotating body that rotates by inputting the human-powered driving force,
`
`and the human-powered driving force. A vehicle with an auxiliary driving force, which is
`
`characterized by detecting using at least one of the input torque amplitudes.
`
`in the vehicie with auxiliary driving force according to claim 1, the O-point setting value
`
`correction uni sets O points when the 0-paint setting value is smaller than the minimum
`
`value as a result of subtracting the 0-point setting value. A vehicle with auxiliary driving
`
`force, characterized in that the value is the same as the minimum value.
`
`in the vehicle with auxiliary driving force according to claim 7, the initial setting uni
`
`compares the maximum value of the measured value with the maximum value of the
`
`predetermined O-poini set value, and ifihe two maximum values are different, the smaller
`
`one is used. A vehicle with an auxiliary driving force, which is characterized in inal the
`
`maximum value of is set to a O-point set value.
`
`Description
`
`Notice
`
`This transialion is machine-generated.
`
`It cannot be guaranteed that
`
`if
`
`is intelligible,
`
`accurate, complete,
`
`reliable or fit for specific purposes. Crilical decisions, such as
`
`commercially relevant ar financial decisions, should not be based on machine-transiation
`
`output.
`
`DESCRIPTION JP20001 904434
`
`

`

`Auxillary powered vehicie
`
`(0004]
`
`The present invention relaies to a vehicle with auxiliary power provided with a O-point
`
`setting device that sets a 0-point setting value corresponding to a detection value of a
`
`human-powered detector in a no-load state after ihe power is turned on.
`
`£0002]
`
`AS a conveniional vehicle with auxiliary power, for example, there is a bicycle with an
`
`electric motor described in Patent Document 1. This bicycle with an electric motar is
`
`configured so that an auxiliary driving force of the motor is generated accarding to the
`
`magnitude of a human-powered driving force consisting of a force for the occupant to
`
`step on the pedal. In this bicycle with an electric motor, the magnitude of the human-
`
`powered driving force is detected by using a human-powered detector composed of a
`
`potentiometer.
`
`10003]
`
`in vehicles with aundiary cower that set the magnitude of aundiary driving force based on
`
`the magnitude of human-powered driving force,
`
`including conventional bicycles with
`
`electric motors,
`
`the magnitude of human-powered driving force must be correctly
`
`detected by the human-powered detector. Must be.
`
`in order to detect the magnitude of the human-powered driving force with high accuracy,
`
`il is important to correctly set the 0 paint (output value in the no-load state) of the human-
`
`powered detector. Conventionaily, this 0 point is often set when the power of the human-
`
`powered detector is turned on.
`
`[O04]
`
`in a bicycle with an electric motor as disclosed in Patent Document 1, in order to extend
`
`the cruising range per charge of the baitery, itis possible to run by turning on the power
`
`only when an auxillary driving force Is required. be.
`
`

`

`in such a case, the 0 point of the human power detector is set when the vehicle is
`
`traveling by the human power driving force.
`
`£0005]
`
`The bicycle with an electric motor described in Patent Document 1 can set 0 points of
`
`the hurnan power detector even when the power is turned on while the human power
`
`driving force is applied io the human power detector while traveling. IL is configured as
`
`follows.
`
`in this bicycle with an electric motor, a tentative value thal is regarded as 0 point of the
`
`human power detector (hereinafter, this value is referred to as 0 point set value) is a
`
`relatively high value immediately after the power is turned on, that is, a detection value
`
`in the normal operating range. Set io a value near the upper limit of.
`
`in general, the
`
`human-powered driving force in a bicycle is periodically generated like a pulsation by
`
`depressing @ pedal.
`
`FO00G]
`
`in the bicycie shown in Patent Document 71, when the human-powered driving force
`
`generated periodically is minimized, the O-paint set value is reduced by a predetermined
`
`reduction procedure.
`
`in this reduction procedure, the magnitude Gninimum value} of the human-powered
`
`driving force detected by the human-powered detector and the O-paint set value at that
`
`time are added and divided by 2, and the value is set as the new O-point set value. it is
`
`stipulated as. After the 0-point set value decreases in ihis way, the auxiliary driving force
`
`has a size corresponding to the magnitude of the true human-powered driving force,
`
`which is the difference between the O-paint set value and the detected value (measured
`
`value) of the human-power detector. Occurs.
`
` RESP BBS 259 7 HAR
`
`fO007]
`
`However, in the bicycle with an electric motor disciosed in Patent Document 7, since the
`
`

`

`0 point setting value is relatively large immediately afer the power is turned on while
`
`traveling, the auxillary driving force is not generated, or even if fi
`
`is generated,
`
`it
`
`is
`
`extremely small. ..
`
`Then, when the pedal is completely depressed Gvhnen the human-powered driving force
`
`is minimized), the O-point set value is reduced to about 1/2.
`
`(0008
`
`Therefore, when the pedal is depressed next time, the auxillary driving force is generated
`
`with a pedaling force of about 1/2 of the pedaling force that was depressed last time.
`
`Therefore,
`
`in the bicycle with an electric motor described in Patent Document 7, the
`
`magnitude of the auxiliary driving force is greatly changed by correcting the Q-poini set
`
`value after the power is turned an, and depending on the occupant, this auxiliary driving
`
`force is changed. There is a possibilty that you may feel a sense of discamfon due to
`
`the difference in the size of the bicycle. ..
`
`(0009)
`
`The present invention has been made to eliminate such a feeling of sirangeness, and a
`
`vehicie wilh auxiliary power capable of correctly setting the 0 point of ihe human power
`
`detector without the occupant feeling the feeling of strangeness after the power is turned
`
`on while driving. The purpose is to provide.
`
`£0010]
`
`in order to achieve this object, the auxiliary powered vehicle according fo the present
`
`invention has a human power detector for detecting the magnitucie of the human power
`
`driving force consisting of the power of an occupani, and the detection value of the
`
`human power detector in a no-load state. The size corresponding to the magnitude of
`
`the true human-powered driving farce, which is the difference between the 0-point setting
`
`device that seis ine O-paint setting value corresponding to the above after the power is
`
`turned on and the measured value of the O-point setting value anc the human power
`
`detector.
`
`In a vehicle with an auxiliary power equipped with an auxiliary drive force
`
`generator for generating the auxiliary drive force of the above, when ithe actual
`
`

`

`measurement value fluctuates within a predetermined time from the time when the power
`
`is turned on to the 0 paint setling device, ihe maximum of the actual measurement value
`
`is reached. An initial setting unit that sets one of the value and the maximum value of the
`
`predetermined O-paint set value to the 0-point set value, a minimum value detection unit
`
`thai deiecis the minimum value of the measured vaiue afier the power is turned on, and
`
`a unit.
`
`It is provided with a O-point setting value correction unit that repeatediy reduces
`
`the O-point set value by @ predetermined reduction procedure until it becomes equal to
`
`ine minimum value, and repeais ihe reduction procedure every predetermined waiting
`
`period to set the Q-point set value. H is determined that the value is reduced by
`
`subtraction and the O-point set value is gradually reduced.
`
`F001 4]
`
`in the present invention, the end time of the standby period is the mileage of the vehicie,
`
`the traveling time of the vehicle, the number of rotations of the rotating body rotated by
`
`the input of the human-powered driving force, and the input torque amplitude of the
`
`human-powered driving force. It is detected using at least one of the numbers.
`
`jO012]
`
`in the present invention, the O-paint set value correction uni sets the O-paint set value to
`
`the minimum value when the Q-point set value becomes smaller than ihe minimumvalue
`
`as a result of reducing the 0-point set value by subtraction. li has the same value as.
`
`(0013)
`
`in ihe present invention,
`
`in the present invention, the infllal setiing unfl compares the
`
`maximum value of the measured value with the maximum vaiue of ihe predetermined 6-
`
`point set value, and ifihe two maximumvalues are different, the smaller maximum value
`
`is used. lt is set to the O-point set value.
`
`£0014]
`
`in the present invention, the G-point set value that is largely set after the power fs turned
`
`on can be gradually reduced by a predetermined value.
`
`

`

`The predetermined value can be set fo a small value that does not give a sense of
`
`discomfort to the occupant due to an increase in the auxiliary driving force.
`
`Therefore, according to the present invention,
`
`it
`
`is possible to provide a vehicie with
`
`auxiliary power capable of correctly setting ihe 0 point of the human power detector
`
`without giving @ sense of discomfort to the occupant after the power is turned on during
`
`traveling.
`
`10015]
`
`According io the invention, the end time of the standby period is detected by using any
`
`one of the mileage of the vehicle, the running time, the rotation speed of the rotating
`
`body rotated by the human-powered driving force, and the input torque amplitude
`
`number of the human-powered driving force. Since the degree of freedom in selecting
`
`the method for detecting the end time of the waiting period is increased, the O-point set
`
`value can be corrected fo an appropriate time corresponding to the running state.
`
`Further, among the various detection methods described above, the detection accuracy
`
`can be improved by detecting the end time of the wailing period by combining a plurality
`
`of detection methods.
`
`(0016)
`
`Aecording to the invention in which the O-paint set value is sei to the minimum value
`
`when the value after subtraction of the O-point set value is smaller than the minimum
`
`value afthe measured value of the human power detector, the 0-paint set value is smaller
`
`than the minimum value. Therefore, lis possible to provide a vehicle with auxiliary power
`
`capable of correctly detecting a human-powered driving force.
`
`(0017)
`
`Accarding to the invention provided with an initial setting unit that sets the 0-point set
`
`value by comparing the actually measured value of ine human power delecior wiih the
`
`predetermined 0-point set value, the O-point set value is set when the power is turned on
`
`while driving. Since the inflal value of is nol unnecessarily high, the magnitude at the
`
`stari of generation of the auxiliary driving force can be set to an appropriate magnitude.
`
`

`

`F001 8]
`
`The vehicie with aundiary power, which is the object of the present invention, is a vehicle
`
`equipped with an engine or a motor as an auxiliary driving force generator, and is a wheel
`
`of a two-wheeled vehicle, a three-wheeled vehicle, a four-wheeled vehicle, eic., which
`
`traveis by the force of an occupant and the auxiliary driving force. it is all vehicies that
`
`run by rotating.
`
`These vehicies also include electric wheelchairs.
`
`inthis embodimert, an example in which the present invention is applied to an electrically
`
`power assisted bicycle will be described.
`
`Hereinafter, an embodiment of the electrically power assisted bicycle will be described
`
`in detail with reference fo FIGS. 14 fo 4.
`
`FO019]
`
`FIG.
`
`ft
`
`is a block diagram showing a configuration of a contro! system of an electrically
`
`power assisted bicycle according to this embodiment, FIG. 2 is a flowchart for explaining
`
`the operation of the Q-point setting device, and FIGS. 3 and 4 explain the oneration of
`
`the O-point setting device. The figure (A} shows the change of the human power driving
`
`farce, the minimum value and the 0 point set value, and the figure (B} shows the change
`
`of the assist ratio.
`
`£0020)
`
`in the electrically assisted bicycle according to this embodiment, the motor 1 (FIG. 1) has
`
`a human-powered driving force consisting of a force for the occupant to slep on the pedal
`
`(not shown) and a predetermined assist ratio with respect io the magnitude ofthe human-
`
`powered driving force. The auxiliary driving force generated by (see) is transmitted to the
`
`rear wheels (not shown) to drive the bicycie.
`
`The motor 7
`
`is composed of a DC motor, and the magnitude of the auxiliary driving force
`
`is controlled by the motor controller 2 shown in FIG.
`
`

`

`F002 1]
`
`The motor controller 2 includes a CPU 3 and a motor drive circuit 4.
`
`The CPU 3 includes a torque sensor input processing unit 11, a torque current calculation
`
`unit 12, a duty calculation unit 13, a torque O paint calculation unit 14, and a vehicle
`
`speed calculation processing unit 15.
`
`£0022]
`
`The torque sensor inpul processing uni 17 is connected to the torque sensor 16 and
`
`detects the magnitude of ihe human-powered driving force based on the detection signal
`
`(actual measurement value of the torque sensor 18) sent from ihe torque sensor 16.
`
`The torque sensor 16 according to this embodiment detects the magnitude of torque
`
`applied to a rotating body (not shown) that rotates integrally with a pedal (not shown),
`
`and uses the magnitude of the detected torque as a vallage value for the motor. The one
`iQ be sent to the controller 2 is used.
`
`The rotating body includes, for example, a pedal crankshak.
`
`The torque sensor 16 constitutes the human-powered detector according to the present
`invention.
`
`{0023}
`
`The torque current calculation unit 12 has a function of calculating the magnitude of the
`
`auxiliary driving force corresponding to the magnitude of the human-powered driving
`
`force delecied by ihe torque sensor input processing unit 11, and a motor current that
`
`can obtain this auxiliary driving force. Has a function of sending the value of to the DUTY
`
`calculation unt 13, which will be described later, as a current command value.
`
`fo024]
`
`in order to obiain the maqnituce of the auxiliary driving force, the irue human power
`
`

`

`consisting of the difference between the 0-point set value described later and the human-
`
`powered driving force (measured value of the torque senser 16) detected by the torque
`
`sensor input processing unit 11 The driving force is obtained, and this is performed by
`
`multiplying this true human-powered driving force by a predetermined assist ratio.
`
`The 0-poini set value is a value corresponding to the value detected by the torque sensor
`
`16 in the no-load state, and is set by the tarque 0-point calculation unit 14 described later.
`
`(0025]
`
`The assist ralio is sel to a ratio corresponding io ine magnitude of ihe true human-
`
`powered driving force.
`
`That is, the assist ratio is relatively small when the irue human-powered driving force is
`
`relatively small, and relatively large when the true human-powered driving force is
`
`relatively large.
`
`(0026)
`
`The duly caiculation unit 13 anc the motor drive circuit 4 are configured toa control the
`
`current flowing through the motor 1 sq that the auxiliary driving force obtained by the
`
`torque current calculation unit 12 is generated from the motor 7.
`
`The auxiliary driving force generator 21 according to the present invention is configured
`
`by ihe duty calculation unit 13, the motordrive circuit 4, and the moior 1.
`
`£0027]
`
`The mator drive circuit 4 is cannmected to the batiery 23 via the main switch Zz.
`
`The motor controller 2 is supplied with power from the battery 23 by turning on the main
`
`switch 22, and starts the contro! operation.
`
`The time when the main switch 22 is turned on is the time when the power is turned on
`
`in ihe present invention.
`
`

`

`The main switch 22 is provided in the viciniy of the steering handle (not shown) so that
`
`the occupant can operate # even while traveling,
`
`£0028]
`
`The torque O-point calculation unii 14 is for setting @ O-point set value, and includes an
`
`initial setting unit 24, a minimum value detection unit 25, and a O-point set value
`
`correction unit 26, which will be described later.
`
`The torque O-paint calculation unt 14 constitutes the O-point setting device 27 according
`
`to the preseni invention.
`
`FO029]
`
`The initial setting unt 24 determines whether or not the measured value of the torque
`
`sensor 16 fluctuates within a predetermined time after the power is turned on, and sets
`
`the initial value of the O-noint set value according fo the determination result as described
`
`later. Set.
`
`The predetermined time here is required for the initialization of the motor controller 2 to
`
`ne completed and for the signals of various sensors such as the current sensor (not
`
`shown) and the temperature sensor for the motor controller (not shown) to be stabie. It's
`
`time.
`
`The predetermined ime is, for example, about 50 msec.
`
`in the following,
`
`the period fram the time when the power is turned on until the
`
`predetermined time elapses is simply referred to as a fluctuation range determination
`zone,
`
`(0030
`
`When the measured value of the torque sensor 16 does not fluctuate in tne fluctuation
`
`width determination zone after the power is turneci on @vhen the power is turned on in a
`
`stationary stats},
`
`the initial
`
`setting unit 24 torques when the fluctuation width
`
`determination zone ends. The measured value of the sensor 16 is set io ihe 0 point set
`
`

`

`value.
`
`On the other hand, when the measured value of the torque sensor 16 fluctuates in the
`
`fluctuation range determination section afier the power is turned on G@vhen the power is
`
`turned on while traveling), the initial setting unit 24 is the maximum value of the measured
`
`value of the torque sensor 16. Giaximum value of fuctuating measured value) is
`
`compared with a predetermined 0-point set value (maximum value of 0-point set value).
`
`The predetermined 0-point set value is set to a value substantially equal to the maximum
`
`value of the human-powered driving force detected by the torque sensor 16 during
`
`normal traveling.
`
`The predefermined maximum value is storéd in advance in the memory (ROM) 3&8
`
`provided in the motor controller 2.
`
`£0034]
`
`The initial setting uni 24 compares the maximum value of the actually measured value
`
`wiih the predeiermined maximum value as described above, and when both of ihese
`
`maximum values are equal, sets the predetermined maximum value to the 0 point set
`
`value. if both of these maximum values are different, the smaller maximum value is set
`
`to the O point setting value.
`
`fO032]
`
`The minimum value detection unit 25 is configured to detect the minimum value
`
`(minimum value of ine human-powered driving force) of the measured value of the torque
`
`sensor 16 afier the power is turned on.
`
`More specifically, the minimum vaiue detection unit 25 compares the magnitude of the
`
`measured value of the past torque sensor 16 with the magnitude of the measured value
`
`af the current torque sensor 16, and when the current measured value is smatler, this
`
`The measured value is newly set as the minimum value.
`
`Tris minimum value is stored in the memory CRAM) 29 provided in the CPU 3 each time.
`
`

`

`FO033]
`
`The O-point set value correction unit 26 is configured to repeatedly reduce the 0-point
`
`set value set to the maximum by the initial setting unit 24 by a predetermined reduction
`
`procedure until it becomes equal to the minimum value.
`
`The O-point set value afer the decrease is stored in the memory (RAM) provided in the
`CPU 3 each time.
`
`£0034]
`
`in the reduction procedure, a predetermined value is repeatediy subtracted from the 0
`
`set value (decreased by subtraction) every predetermined slandby period afer the power
`
`is turned on, and the value is gradually reduced until the 0 point set value reaches the
`minimum value. it has been decided.
`
`in detecting the end time of the waiting period, at least one of the first fo fourth detection
`
`methods described later can be used.
`
`(0035]
`
`The first detection method is a method in which the end ume of the standby period is
`
`when the mileage after ihe power is turned on or after the subtraction process reaches
`
`a predetermined distance.
`
`The mileage can be obtained by multiplying the vehicle speed calculated by the vehicle
`
`speed calculation processing unit 15 by the time.
`
`The vehicle speed caiculation processing unfit 15 can adopt a configuration in which the
`
`vehicle speed is calculated by using ihe rotation speed of ihe motor 1 detected by the
`
`encoder 31 provided in the motor 1.
`
`The encoder 31 that has already been provided for controlling the rotation of the motor
`
`1 can be shared.
`
`10036]
`
`

`

`in order to obtain the vehicle speed, instead of using the encoder 31, the vehicle speed
`
`sensor 32 and the pedal rotation sensor 33 can be used as shown by the alternate long
`
`and short dash line in FIG.
`
`The vehicle speed sensor 32 detects the rotation speed or the number of rotations when
`
`the rear wheels or the front wheels rotate, and the pedal rotation sensor 33 detecis the
`
`rotation speed or the number of rotations of the pedal crankshaft.
`
`The mileage can also be directly detected by using a sensor that detects thai the rear
`
`wheels or ihe front wheels have rotaied by a predetermined angie.
`
`{0037}
`
`The second detection method is a methad in which the end time of the standby periad is
`
`when the elapsed time afer the power is turned on or afer the sublraction process
`
`reaches a predetermined time.
`
`The elapsed time can be measured by using the timer 33 provided in the motor controller
`
`2.
`
`(0038)
`
`The third detection method is a method in which the end time of the standby periad is
`
`when the rolation speed of the rotating body rotating by the input of the human-powered
`
`driving force reaches a predetermined rotation speed.
`
`As this rotating body, for example, there is a pedal crankshafi.
`
`The number of rotations of the pedal crankshafi can be detecied by the pedal rotation
`
`sensor 33.
`
`(0039)
`
`The fourth detection method is a method in which the end time of the standby period is
`
`set when the input torque amplitude number of ihe human-powered driving force reaches
`
`

`

`a predetermined value.
`
`The input torque amplitude number is when the human-powered driving force generated
`
`to puisate when the occupant depresses the pedal changes from the maximum value to
`
`the minimum vaiue, or when this human-powered driving force changes from the
`
`minimum vaiue to the maximum value.
`
`is the number of times that is counted as one
`
`time,
`
`in this embodiment, the end time of the standby period is detected by using the input
`
`torque amplitude number and the traveling time so that the 0 point sel value is subtracted
`
`when the human-powered driving force is Q.
`
`FO040]
`
`ifthe end time of the waiting period can be accurately detected by only one of the above-
`
`mentioned first fo fourth detection methods,
`detection methads.
`
`it
`
`is not necessary to combine the other
`
`However,
`
`if there is a risk that the detection accuracy will be low with only one of the
`
`above detection methods, the traveling time is also added to the judgment conditions,
`
`thai is, the end time of the waiting period is combined with the second detection method.
`
`is desirable to detect.
`
`[0041]
`
`The predetermined numerical value (hereinafter, simply referred to as the subtraction
`
`value) thal the O-point set value correction unt 26 subtracts from the O-paint set value
`
`may give a sense of discomfort to the occupant when the auxiliary driving force increases
`
`due to the decrease of the 0-point set value. Nat set to a small value.
`
`The subtraction value according to this embodiment is set to a value that is 1/50 of the
`
`auiput voltage of the torque sensor 16.
`
`fO042]
`
`The O-point set value correction unit 26 has a configuration in which the O-poini set vaiue
`
`

`

`is set to the same value as the minimum value when the 0-point set value is smaller than
`
`ihe minimum value as a result of subtracting the subtraction value from the O-point set
`value. it has been taken.
`
`That is, the O-point set value finally becomes the minimum value of the measured value
`
`(human-powered driving force) of the torque sensor by repeating the subtraction.
`
`10043]
`
`Next, the operation of the motor controller 2 described above wil be described with
`
`reference to the flowchart shown in FIG.
`
`When the main switch 22 is turned on and the power Is turned on, first,
`
`in step S1, the
`
`parameter for detecting the end time of the standby period is updated by ihe O-point set
`value carrection unit 26.
`
`The parameters include mileage, pedal rotation speed, input torque amplitude number,
`
`running time, and the like.
`
`in the first case immediately afier the power ts turned on, these parameters are cleared
`ta OQ.
`
`[OO44]
`
`Further, when the power is turned on, the torque sensor 16 and ihe torque sensor input
`
`processing unil 11 detect the magnitude of the human-powered driving farce, and the
`
`initial setting unit 24 seis the initial value of the O-point set value.
`
`Here, the operation of the initial setting unit 24 will be described with reference to FIGS.
`3 and 4.
`
`in FIGS. 3 and 4, the time when the power is turned on is indicated by reference numeral
`TO.
`
`Note that FIGS. 3 and 4 show an example in which the measured value of the torque
`
`sensor 16 fluctuates when ithe power is turned on.
`
`

`

`The intial setling unit 24 determines whether or not the measured value of the torque
`
`sensor 16 fluctuates in the fluctuation range determination section after the power is
`
`turned on, and if it does not fluctuate, the measured value of the torque sensor 16 at that
`
`time is set to 0 points. Set value.
`
`FO045]
`
`When the measured value of the torque sensor 16 is fluctuating and the maximum value
`
`af the measured value in the fluctuation range determination zane is smaller than the
`
`predetermined O-point set value, the fluctuation range determination is performed as
`
`shown in FiG. The measured value of the torque sensor 16 at T1 at the end of the section
`
`is newly set as a O-poini set value.
`
`On the other hand, when the measured value of the torque sensor 16 is Huctuating and
`
`the maximum value of the measured value in the fluctuation range determination zone
`
`is equal to or more than a predetermined 0 point set value, as shown in FIG. The preset
`
`0-point set value is used as it is, and the process praceeds to the next step.
`
`When the power is turned on, the assisi ratio becomes the minimum as shown in FIG. 3
`
`(B).
`
`fO046]
`
`Further, when the power is turned on, the minimum value detection unit 25 stores the
`
`first actually measured value of the torque sensor 16 In the memory 29 as the minimum
`
`value of the human-powered driving force.
`
`After that, in step S2, the minimum value detecting unit 25 determines whether or not the
`
`minimum value of the measured value of the torque sensor 16 is larger than the
`
`measured value of the current torque sensor 16.
`
`ifthe determination resull is NO, that is, if ihe minimum value is equal to or less than the
`
`current actual measurement value, the process proceeds to step 54 described later, and
`
`if the determination result is YES, the current actual measurement value is set as the
`
`new minimum value in step S3.
`
`

`

`(0047)
`
`That is, the minimum value is set when the measured value of the torque sensor 16
`
`decreases as the pedaling farce decreases afier the power source is turned on, as shown
`
`by the broken line in FIGS. 3 (A) and 4 (A) (FIGS. 3 and 3). Whenindicated by reference
`
`numeral A in 4), the value decreases as the measured value decreases.
`
`(0048]
`
`in step S4, the O-point set value correction un 26 determines whether or not the
`
`minimum value and the current O-point set value are not the same.
`
`ifthe delermination resull is NO, that is, if both of them are the same, the process returns
`
`to step Tt and the above-described contral operation is repeated.
`
`if the determination resuli is YES,
`
`in step 55, the O-point set value correction unit 26
`
`determines whether or not the waiting period has ended.
`
`(0049]
`
`in step SS, whether the mileage is longer than D Gor example, 20 m), the pedal rotation
`
`speed is more than N (for example, one rotation), or the input torque amplitude number
`
`is more than M (for example, one). Whether or not, or whether or not the running time is
`
`ionger than T Gor example, 1 second) is determined.
`
`in this embodiment, the end time of the standby period is detected by using the input
`
`torque amplitude number (see FIG. 3) and the running time.
`
`This traveling time is the time elapsed afier being updated or initialized in step $1.
`
`in this embodiment, when the output of the torque sensor 16 becomes maximum
`
`(indicated by reference numeral T2 in FIGS. 3 and 4) and then the output of the torque
`
`sensor 16 becomes minimum (reference numeral T3 in FIGS. 3 and 4}. The number of
`
`input torque amplitudes is increased by1.
`
`

`

`FO0SO]
`
`if the above-menti