Man-powered vehicle and drive control device

Abstract

To efficiently reduce a load of an occupant's tread force in a vehicle during running.SOLUTION: A vehicle 10 comprises: a plurality of wheels 21 and 22; a motor 3; a pedal 31; a vehicle speed sensor 61; and a drive control part 5 that controls drive of the motor 3. The drive control part 5 sets attainment of a setting speed by a vehicle speed as the first condition, without being associated with acceleration by only power of the motor 3, when the vehicle carrying the occupant runs, and performs automated control for controlling the vehicle speed by only a driving force of the motor 3, in the case where at least the first condition is satisfied.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to the control of a vehicle equipped with a motor and pedals. [Background technology]

[0002] Japanese Patent No. 3849452 (Patent Document 1) describes a control circuit for an electrically assisted bicycle that has an automatic speed control function for switching to a constant speed when the traveling speed is 15 km / hour or more, and an automatic torque control function for switching to a constant torque when the traveling speed is 15 km / hour or less. This automatic speed control function controls the bicycle to a constant speed by assisting the pedaling force with motor torque.

[0003] Japanese Patent No. 6226825 (Patent Document 2) discloses an electrically assisted bicycle that provides assistance when a user pushes the electrically assisted bicycle without riding it. When this electrically assisted bicycle is in a first state in which vehicle speed is generated without pedaling force and the user operates an operating unit, the motor control maintains the first vehicle speed at the time of operation from the point in time when the operating unit was operated. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 3849452 [Patent Document 2] Patent No. 6226825 Summary of the Invention [Problem to be solved by the invention]

[0005] The present application discloses a vehicle that can efficiently reduce the pedaling load of a passenger while the vehicle is traveling. [Means for solving the problem]

[0006] A human-powered vehicle according to an embodiment of the present invention includes a plurality of wheels, a motor that supplies driving force to at least one of the wheels, a pedal to which a pedaling force of a passenger is applied to drive at least one of the wheels, a vehicle speed sensor that detects a vehicle speed, and a drive control unit that controls driving of the motor. The drive control unit sets a first condition as to whether the vehicle speed detected by the vehicle speed sensor reaches a set speed without acceleration due only to the driving force of the motor while the passenger is riding on the human-powered vehicle and traveling, and executes automatic control to control the vehicle speed only by the driving force of the motor when at least the first condition is satisfied. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a left side view showing a vehicle according to the present embodiment. [Diagram 2] FIG. 2 is a block diagram showing an example of a mechanical and electrical connection configuration of the components of the vehicle shown in FIG. [Diagram 3] Fig. 3(a) is a diagram showing an example of normal assist control and automatic control by the drive control section, and Fig. 3(b) is a diagram showing an example of a case where only normal assist control is executed. [Figure 4] FIG. 4 is a diagram showing another example of the normal assist control and the automatic control by the drive control section. [Diagram 5] FIG. 5 is a flowchart showing an example of an automatic control process performed by the drive control unit 5. [Figure 6] FIG. 6 is a flowchart showing an example of S8 (taper mode output calculation) in FIG. [Figure 7] FIG. 7 is a flowchart showing another example of S8 (taper mode output calculation) in FIG. [Figure 8] FIG. 8 is a graph showing an example of a change in vehicle speed over time in the gradual decrease mode. [Figure 9] FIG. 9 is a graph showing an example of a change in vehicle speed over time when the vehicle is traveling downhill. [Figure 10] FIG. 10 is a graph showing an example of a change in vehicle speed over time when the vehicle travels on a flat road, a downhill road and again on a flat road in this order. [Figure 11] FIG. 11 is a graph showing an example of the change in vehicle speed over time when the vehicle travels on a flat road, an uphill road, and then on a flat road in this order. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] (Configuration 1) A human-powered vehicle according to an embodiment of the present invention includes a plurality of wheels, a motor that supplies driving force to at least one of the plurality of wheels, a pedal to which a pedaling force of a passenger is applied to drive at least one of the plurality of wheels, a vehicle speed sensor that detects a vehicle speed, and a drive control unit that controls driving of the motor. The drive control unit sets a first condition as to whether the vehicle speed detected by the vehicle speed sensor reaches a set speed without acceleration due only to the driving force of the motor while the passenger is riding on the human-powered vehicle and traveling, and executes automatic control to control the vehicle speed only by the driving force of the motor when at least the first condition is satisfied.

[0009] According to the above configuration 1, when the vehicle speed reaches the set vehicle speed without relying only on the driving force of the motor while the vehicle is traveling with a passenger on board, the drive control unit controls the vehicle speed by the motor even without input of pedal force. This allows the vehicle speed to be increased not only by the motor but also by pedal force, downhill slope, and other factors until the set vehicle speed is reached, and after the set vehicle speed is reached, automatic control of the vehicle speed without relying on pedal force is possible. Therefore, the load of pedal force on the passenger while traveling can be efficiently reduced. For example, when the passenger pedals hard to reach the set vehicle speed, automatic control of maintaining the vehicle speed or mitigating deceleration is possible.

[0010] In configuration 1, the first condition is satisfied, for example, when the set vehicle speed is reached by only the pedaling force of the occupant, by the pedaling force of the occupant and the motor driving force supplementing the pedaling force, or by acceleration due to an external factor such as a downhill slope or a tailwind. In this way, the occupant reaches the set vehicle speed of the first condition by making full use of his / her driving ability without relying on acceleration by the motor driving force alone. The set vehicle speed is set within a range that can be reached by the driving ability of the occupant. Therefore, unlike an electric vehicle that accelerates by operating the grip accelerator only, for example, the human-powered vehicle of configuration 1 allows self-propulsion by only the driving force of the motor within a range that matches the driving ability of the occupant.

[0011] (Configuration 2) A human-powered vehicle according to an embodiment of the present invention includes a plurality of wheels, a motor that supplies driving force to at least one of the wheels, a pedal to which a pedal force of a driver is applied to drive at least one of the wheels, a torque sensor that detects the pedal force applied to the pedal, and a drive control unit that controls the drive of the motor. The drive control unit sets a first condition to be the pedal force detected by the torque sensor reaching a set condition, and executes automatic control to control the vehicle speed only by the driving force of the motor when at least the first condition is satisfied.

[0012] According to the above configuration 2, when the pedaling force of the rider reaches a set level, the drive control unit controls the vehicle speed only by the motor. As a result, until the pedaling force reaches the set level, the vehicle accelerates mainly by pedaling without relying only on the power source, and after the pedaling force reaches the set level, automatic control of the vehicle speed without relying on the pedaling force is possible. Therefore, the load of the pedaling force of the rider while traveling can be efficiently reduced. For example, when the rider pedals hard and the pedaling force reaches the set level, automatic control is possible to maintain the vehicle speed at that time or to ease the deceleration. The first condition may be that, while the occupant is riding in the human-powered vehicle and traveling, the vehicle speed detected by the vehicle speed sensor reaches a set speed without acceleration due to only the driving force of the motor, or the pedal force detected by the torque sensor reaches a set condition. Alternatively, the first condition may be that, while the occupant is riding in the human-powered vehicle and traveling, the vehicle speed detected by the vehicle speed sensor reaches a set speed without acceleration due to only the driving force of the motor, and the pedal force detected by the torque sensor reaches a set condition.

[0013] An example of a mode in which the vehicle speed is controlled only by the driving force of the motor is a mode in which the vehicle speed is controlled by the driving force of the motor when no pedal force is being input. For example, in automatic control, the drive control unit can control the vehicle speed by the power of the motor when the rotation or torque of the pedal is not detected. Specifically, the automatic control may be executed when the first condition is satisfied and the rotation or torque of the pedal is not detected. As an example, the automatic control may be started at the point in time when the rotation or torque of the pedal stops after the first condition is satisfied.

[0014] A case where the first condition is "the vehicle speed detected by the vehicle speed sensor reaches a set speed without acceleration only by the motor power while a passenger is riding on the human-powered vehicle and traveling" will be described. In this case, it is not necessarily necessary for the drive control unit to detect that a passenger is riding on the vehicle and traveling or to detect acceleration only by the motor power in order to determine whether the first condition is satisfied. The first condition can be determined, for example, based only on the vehicle speed detected by the vehicle speed sensor by setting or controlling the drive control unit. For example, the drive control unit may supplement the pedal force with the motor driving force only when a pedal force is input until the set vehicle speed is reached, so that the vehicle is not accelerated only by the motor driving force, and after the set vehicle speed is reached, control of the vehicle speed only by the motor is executed. In this way, when the vehicle speed reaches the set vehicle speed, it can be determined that the set vehicle speed has been reached without acceleration only by the driving force. In addition, for example, by setting the set vehicle speed to a vehicle speed range (e.g., 10 km / h or higher) that can only be achieved when an occupant is on board and driving, when the vehicle speed reaches the set vehicle speed, it can be determined that the set vehicle speed has been reached while an occupant is on board and driving.

[0015] (Configuration 3) In the above configuration 1 or 2, the first condition may be that the vehicle speed reaches the set speed at least by the pedaling force of the occupant. In this way, when the set vehicle speed is reached at least by pedaling by the occupant, automatic control of the vehicle speed independent of pedaling can be executed. The form in which the vehicle speed reaches the set speed at least by the pedaling force of the occupant includes a form in which the set vehicle speed is reached only by the pedaling force of the occupant, and a form in which the set vehicle speed is reached by the pedaling force of the occupant and the power of the motor.

[0016] (Configuration 4) In any of the above configurations 1 to 3, the automatic control may be a control for maintaining the vehicle speed by the driving force of the motor, or a control for the degree of reduction in the vehicle speed by the driving force of the motor. This makes it possible to maintain the vehicle speed or ease the deceleration only by the driving force of the motor after the set vehicle speed or the set level of the pedal force is reached. The control for the degree of reduction in the vehicle speed by the driving force of the motor may be, for example, a control for not increasing the vehicle speed and suppressing the degree of deceleration by the driving force of the motor. By this control, the vehicle gradually reduces the vehicle speed while being assisted by the driving force of the motor. Hereinafter, this control may be referred to as a gradual reduction control. In the gradual reduction control, the degree of reduction in the vehicle speed is made gentle by the driving force of the motor. Note that, for example, the drive control unit may not accelerate (increase speed) only by the driving force of the motor in the automatic control.

[0017] For example, in the automatic control, the occupant may be able to select, by a selection operation, whether to execute control for maintaining the vehicle speed or to execute control for the degree of reduction in the vehicle speed. Also, for example, in the case where control of the degree of reduction in vehicle speed is executed in the automatic control, the degree of reduction in vehicle speed may be made designable by a driver's operation.

[0018] (Configuration 5) In any one of the above configurations 1 to 4, the drive control unit may execute the automatic control when the first condition is satisfied and the occupant issues an instruction to execute the automatic control, thereby allowing the occupant to operate whether or not to execute the automatic control.

[0019] (Configuration 6) In any one of the above configurations 1 to 5, the drive control section may execute the automatic control when the first condition is satisfied and the occupant stops pedaling the pedal, thereby enabling the automatic control in a situation where the first condition is satisfied and the occupant is not pedaling.

[0020] (Configuration 7) In any one of the above configurations 1 to 6, the drive control unit may release the automatic control when a release condition is satisfied in the automatic control. The release condition may include at least one of detection of braking, detection of the pedal force or rotation, operation of a release operator by the occupant, vehicle speed reaching a set upper limit, vehicle speed reaching a set lower limit, detection of a disturbance, detection of an increase in vehicle speed, lapse of a set duration, or detection of curved driving. This allows the automatic control to be released at an appropriate time depending on the situation.

[0021] (Configuration 8) In any of the above configurations 1 to 7, the drive control unit may execute the control of the vehicle speed by setting the vehicle speed when the pedaling of the rider on the pedal stops after the first condition is satisfied as a reference vehicle speed in the automatic control. This enables automatic control of the vehicle speed based on the vehicle speed reached by the rider's pedaling. Therefore, automatic control of the vehicle speed according to the rider's pedaling becomes possible. In addition, the reference vehicle speed is set to a vehicle speed range that can be reached by the rider's pedaling. The vehicle speed when the rider's pedaling stops, which is the reference vehicle speed, is not limited to the vehicle speed when pedaling stops strictly. For example, the vehicle speed detected upon detection of pedaling stop may be set as the reference vehicle speed.

[0022] As the automatic control, for example, it is possible to control the reference vehicle speed or control the rate of deceleration from the reference vehicle speed. In this way, in the automatic control, the motor may be controlled so that the vehicle speed does not exceed the reference vehicle speed by the motor driving force.

[0023] The cessation of pedaling by the rider can be detected, for example, by detecting at least one of the cessation of input of pressure to the pedal and the cessation of rotation of the pedal.

[0024] The embodiment of the present invention also includes a drive control device constituting the drive control section in any one of the above configurations 1 to 8. The embodiment of the present invention also includes an automatic control method executed by the drive control section.

[0025] Hereinafter, a human-powered vehicle according to an embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and the description of those parts will not be repeated. Furthermore, the dimensions of the components in each drawing do not faithfully represent the actual dimensions of the components and the dimensional ratios of each component. In the following description, the front-rear, left-right, and up-down directions of the vehicle refer to the front-rear, left-right, and up-down directions of the vehicle based on a state in which an occupant sits on a saddle (seat 24) and grips a handlebar. The front-rear, left-right, and up-down directions of the vehicle are the same as the front-rear, left-right, and up-down directions of the vehicle body, i.e., the body frame. Furthermore, the traveling direction of the vehicle is the same as the front-rear direction of the vehicle. The following embodiments are illustrative, and the present invention is not limited to the following embodiments.

[0026] <Example of vehicle overall configuration> FIG. 1 is a left side view showing a human-powered vehicle 10 (hereinafter simply referred to as "vehicle 10") in this embodiment. The symbols F, B, U, and D in FIG. 1 represent front, rear, top, and bottom, respectively. The vehicle 10 is, as an example, an electrically assisted bicycle. The vehicle 10 includes a plurality of wheels 21, 22, a body frame 11, a motor 3, and a pedal 31. The plurality of wheels 21, 22 and the pedal 31 are rotatably supported relative to the body frame 11. The vehicle 10 also includes a transmission mechanism that transmits the rotation of the motor 3 to at least one of the wheels 21, 22, and a transmission mechanism that transmits a pedaling force applied to the pedal 31 to at least one of the wheels 21, 22. At least one of the wheels 21, 22 is driven by at least one of the pedaling force of the pedal 31 or the driving force of the motor 3.

[0027] As shown in FIG. 1, a vehicle 10 has a body frame 11. The body frame 11 extends in the front-rear direction. The body frame 11 has a head pipe 12, an upper frame 13u, a down frame 13d, a seat frame 14, a pair of chain stays 16, and a pair of seat stays 17. The head pipe 12 is disposed at the front of the vehicle 10. The head pipe 12 is connected to the front ends of the down frame 13d and the upper frame 13u. The down frame 13d and the upper frame 13u extend in the front-rear direction. The down frame 13d and the upper frame 13u extend diagonally downward. The upper frame 13u is located above the down frame 13d. The rear end of the upper frame 13u is connected to the seat frame 14. The rear end of the down frame 13d is connected to a bracket 15. The lower end of the seat frame 14 is connected to the bracket 15. The seat frame 14 extends upward and diagonally backward from the bracket 15. The body frame 11 may have a configuration without the upper frame 13u.

[0028] A handle stem (steering column) 25 is rotatably inserted into the head pipe 12. A handle 23 is fixed to the upper end of the handle stem 25. A front fork 26 is fixed to the lower end of the handle stem 25. A front wheel 21 is rotatably supported by an axle 27 at the lower end of the front fork 26.

[0029] Grips are attached to the left and right ends of the handlebar 23. A left brake lever 74 is attached to the left part of the handlebar 23, and a right brake lever 74 is attached to the right part of the handlebar 23. The left brake lever 74 is a lever for operating a brake 76 of the rear wheel 22. The right brake lever 74 is a lever for operating a brake 75 of the front wheel 21.

[0030] A seat pipe 28 is inserted into the cylindrical seat frame 14. The seat 24 is provided at the upper end of the seat pipe 28. In this manner, the body frame 11 rotatably supports the handle stem 25 at the front, and rotatably supports the rear wheel 22 at the rear. The seat 24 and a drive unit 40 are also attached to the body frame 11.

[0031] A pair of chain stays 16 are connected to the rear end of the bracket 15. The pair of chain stays 16 are arranged to sandwich the rear wheel 22 from the left and right. One end of a seat stay 17 is connected to the rear end of each chain stay 16. The pair of seat stays 17 are arranged to sandwich the rear wheel 22 from the left and right. The other end of each seat stay 17 is connected to an upper part of the seat frame 14. The rear wheel 22 is rotatably supported by an axle 29 at the rear ends of the pair of chain stays 16.

[0032] The front fork 26 is provided with a vehicle speed sensor (speed sensor) 61 that detects the rotation of the front wheel 21. The vehicle speed sensor 61 has, for example, a detectable element that rotates together with the front wheel 21 (wheel), and a detection element that is fixed to the body frame 11 and detects the rotation of the detectable element. The detection element detects the detectable element mechanically, magnetically, or optically. Note that the vehicle speed sensor 61 is not limited to the front wheel 21, and may be one that detects the rotation of a rotating body that rotates as the vehicle 10 travels, such as the rear wheel 22, the motor 3, the crankshaft 41, a transmission gear, a chain, etc.

[0033] The vehicle 10 includes a brake sensor 63. The brake sensor 63 detects the brake operation by the occupant, i.e., the actuation of the brakes 75, 76. The brake sensor 63 converts the movement of the brake operation by the occupant into an electric signal. The brake sensor 63 may be, for example, a mechanical or electric switch that detects the movement of a brake lever, or a pressure sensor that detects the brake pressure. The brake sensor 63 is attached to, for example, the handlebar 23 or the vehicle body frame 11.

[0034] The drive unit 40 is attached below the bracket 15 with fastening fittings (not shown). The drive unit 40 has a housing 40a that forms the outer shape of the drive unit 40. The motor 3 is stored inside the housing 40a. A crankshaft 41 penetrates the housing 40a in the left-right direction. The crankshaft 41 is rotatably supported by the housing 40a via a plurality of bearings.

[0035] A torque sensor 62 is provided around the crankshaft 41 to detect the pedaling force of the occupant. The torque sensor 62 detects the torque that rotates the crankshaft 41 around its axis. The torque sensor 62 may be, for example, a non-contact type such as a magnetostrictive type, or a contact type such as an elastic body displacement detection type. The magnetostrictive torque sensor has a magnetostrictive effect and includes a magnetostrictive material that receives the rotational force of the crankshaft, and a detection coil that detects the change in magnetic permeability due to the force of the magnetostrictive material.

[0036] A crank arm 31b is attached to both ends of the crankshaft 41. A pedal step 31a is attached to the tip of each of the crank arms 31b. The crankshaft 41, the crank arm 31b, and the pedal step 31a form the pedal 31. When the rider depresses the pedal 31, the crankshaft 41 rotates. Although not shown, the vehicle 10 is provided with a drive sprocket that rotates together with the crankshaft 41 and a driven sprocket that rotates together with the rear wheel 22. A chain 46 is wound between the drive sprocket and the driven sprocket. Note that a belt, a shaft, or the like may be used instead of the chain 46. A one-way clutch 49 (see FIG. 2) is provided on the rotation transmission path from the driven sprocket to the rear wheel 22. The one-way clutch 49 transmits rotation in the forward rotation direction (forward rotation) and does not transmit rotation in the reverse rotation direction (reverse rotation).

[0037] A transmission mechanism (not shown) that transmits the rotation of the motor 3 to the drive sprocket (or chain 46) is provided within the drive unit 40. The transmission mechanism includes, for example, a reducer (reduction gear) 42 (see FIG. 2). The rotation of the motor is reduced in speed by the reducer 42 and transmitted to the drive sprocket. The transmission mechanism also includes a combining mechanism that combines the rotation of the crankshaft 41 and the rotation of the motor 3 and transmits the combined rotation to the drive sprocket. The combining mechanism has, for example, a cylindrical member. The crankshaft 41 is disposed inside the cylindrical member. The drive sprocket is attached to the combining mechanism. The combining mechanism rotates around the same rotation axis as the crankshaft 41 and the drive sprocket. One-way clutches 43, 44 (see FIG. 2) may be provided on the rotation transmission path from the crankshaft 41 to the combining mechanism and on the rotation transmission path from the motor 3 to the combining mechanism. The rotational force transmitted from the motor 3 through the transmission mechanism to the drive sprocket serves as the driving force for the wheels (rear wheels 22).

[0038] A battery unit 35 is disposed on the down frame 13d. The battery unit 35 supplies power to the motor 3 of the drive unit 40. The battery unit 35 has a battery and a battery control unit (not shown). The battery is a rechargeable battery that can be charged and discharged. The battery control unit controls charging and discharging of the battery, and monitors the output current and remaining capacity of the battery. The battery unit 35 may be disposed on the seat frame 14 or the upper frame 13u.

[0039] The handle 23 is provided with an operator 37 that accepts various operations from the occupant. The operator 37 has an input unit, such as a button that accepts user operations or a touch panel. The operator 37 may also be equipped with a display. In this case, the input unit of a display device constituted by the display may serve as the operator 37. Various information related to the vehicle 10 is displayed on the display.

[0040] 2 is a block diagram showing an example of a mechanical and electrical connection configuration of the components of the vehicle 10 shown in FIG. 1. In the example shown in FIG. 2, the rotation of the pedal 31 (including the pedal step 31a, the crank arm 31b, and the crank shaft 41) is transmitted to the combining mechanism 45 via the one-way clutch 43. The rotation of the motor 3 is transmitted to the combining mechanism 45 via the reducer 42 and the one-way clutch 43. The combining mechanism 45 includes, for example, the above-mentioned combining mechanism, a driving sprocket, a chain 46, and a driven sprocket. In the combining mechanism 45, power is transmitted in the order of the combining mechanism, the driving sprocket, the chain 46, and the driven sprocket. The rotation of the driven sprocket is transmitted to the rear wheel 22 via the drive shaft 47, the speed change mechanism 48, and the one-way clutch 49.

[0041] The speed change mechanism 48 is a mechanism that changes the gear ratio in response to the operation of the speed change operating device 38 by the rider. The speed change operating device 38 is attached to, for example, the handlebars 23 (FIG. 1). In this example, the speed change mechanism 48 is an internal transmission provided between the drive shaft 47 and the rear wheel 22, but the speed change mechanism 48 may be an external transmission. When the speed change mechanism 48 is an external transmission, a multi-stage sprocket may be used as the driven sprocket. In this case, the multi-stage sprocket around which the chain 46 is wound is switched in response to the operation of the speed change operating device 38. The one-way clutch 49 transmits the rotation of the speed change mechanism 48 to the rear wheel 22 only when the rotation speed of the output shaft of the speed change mechanism 48 is faster than the rotation speed of the rear wheel 22. When the rotation speed of the output shaft of the speed change mechanism 48 is slower than the rotation speed of the rear wheel 22, the one-way clutch 49 does not transmit the rotation of the speed change mechanism 48 to the rear wheel 22. The speed change mechanism 48 and the speed change operating device 38 may be omitted.

[0042] The pedaling force generated by the rider depressing the pedal 31 rotates the drive sprocket in the forward rotation direction, and is transmitted via the chain 46 as a driving force that rotates the rear wheel 22 in the forward rotation direction. In addition, the rotational force generated by the operation of the motor 3 rotates the crankshaft 41 in the forward rotation direction. As a result, the rotational force of the motor 3 is transmitted as a driving force that rotates the rear wheel 22 in the forward rotation direction. In addition, when the rider's pedaling force and the rotational force of the motor 3 are transmitted to the crankshaft at the same time, the rotational force of the motor 3 assists (supports) the rider's pedaling force.

[0043] The vehicle 10 has a controller 4 that controls the motor 3. For example, the controller 4 is configured by electronic devices mounted on a board in the housing 49a of the drive unit 40. The electronic devices include, for example, a processor or an electronic circuit. The controller 4 is electrically connected to at least a vehicle speed sensor 61, a torque sensor 62, a brake sensor 63, and the motor 3. In the example shown in FIG. 2, the controller 4 is connected to a crank rotation sensor 64 and a motor rotation sensor 65. These connections may be wired or wireless.

[0044] The crank rotation sensor 64 detects the rotation of the crankshaft 41. The crank rotation sensor 64 may have, for example, a detected element that rotates together with the crankshaft 41, and a detection element that is fixed to the body frame 11 and detects the rotation of the detected element. The detection element can detect the detected element mechanically, optically, or magnetically.

[0045] The motor rotation sensor 65 detects the rotation of the motor 3. The motor rotation sensor 65 may be configured to detect the rotation of a rotor of the motor 3, or may be configured to detect the rotation based on the current, voltage, or other electrical signals of the motor 3.

[0046] The mechanism for transmitting the driving force from the motor 3 is not limited to the above example. For example, the drive unit 40 may have an output shaft extending in the left-right direction from inside the housing 40a to the outside. In this case, the rotation of the motor 3 is transmitted to the output shaft by the transmission mechanism. An auxiliary sprocket is attached to the output shaft outside the housing 40a. A chain 46 is wound around the auxiliary sprocket. The rotational force generated by the operation of the motor 3 rotates the auxiliary sprocket, which in turn rotates the rear wheel 22 in the forward direction via the chain 46.

[0047] In the example of FIG. 1, the motor 3 is housed in a drive unit 40 attached to the body frame 11. Alternatively, the motor may be provided in the hub of a wheel (at least one of the front wheels 21 or the rear wheels 22) of the vehicle 10. In this case, the motor may be an in-wheel type motor (hub motor) built into the hub. The hub motor may include, for example, a rotor and a stator. The rotation shaft of the rotor may be coaxial with the axle 27. The hub may be provided with a gear that transmits the rotation of the hub motor to the wheel (front wheel 21). The gear may be, for example, a planetary gear. In addition, a one-way clutch may be provided in the rotation transmission path between the hub motor and the wheel (front wheel 21).

[0048] <Controller configuration example> In the example of FIG. 2, the controller 4 has a drive control unit 5. As an example, the controller 4 is an MCU (Motor Control Unit). The controller includes, for example, a processor and a memory. The processor can realize the functions of the drive control unit 5 by executing a program in the memory. At least some of the functions of the drive control unit 5 may be realized by a circuit other than the processor. In addition to the drive control unit 5, the controller 4 also has a pedal force detection unit 51, a crank rotation speed detection unit 52, a motor drive unit 53, and a motor monitoring unit 54. These may be configured by a processor or other circuits.

[0049] The pedaling force detection unit 51 detects the pedaling force (torque) by acquiring a signal corresponding to the torque detected by the torque sensor 62. The pedaling force detection unit 51 may acquire a voltage signal or a current signal from the torque sensor 62 and convert it into a torque value, or may acquire the torque value from the torque sensor 62.

[0050] The crank rotation speed detection unit 52 detects the crank rotation speed by acquiring a signal corresponding to the rotation of the crankshaft 41 from the crank rotation sensor 64. The crank rotation speed detection unit 52 may acquire a voltage signal or a current signal (e.g., a pulse signal) from the crank rotation sensor 64 and convert it into a rotation speed, or may acquire the value of the rotation speed.

[0051] The vehicle speed sensor 61 detects the rotation angle of the front wheel 21 (or other rotating body) and outputs a signal according to the rotation angle to the controller 4. For example, the vehicle speed sensor 61 detects the rotation of the front wheel 21 at every predetermined angle and outputs a square wave signal or a sine wave signal. The processor of the drive control unit 5 calculates the vehicle speed by calculating the rotation speed of the front wheel 21 from the output signal of the vehicle speed sensor 61. Note that the calculation of the rotation speed or vehicle speed may be performed by the vehicle speed sensor 61.

[0052] The motor monitoring unit 54 obtains a signal indicating the rotation of the motor, such as the number of rotations or the rotation speed of the motor, from the motor rotation sensor 65. Note that the motor monitoring unit 54 may obtain values ​​related to the driving of the motor 3, such as the current and voltage of the motor 3, in addition to the number of rotations or the rotation speed of the motor.

[0053] To realize the functions of the drive control unit 5, the processor outputs a control signal (e.g., a motor command value) to the motor 3. The motor drive unit 53 operates according to the control signal to drive the motor 3. The motor drive unit 53 is, for example, an inverter, and supplies power from the battery unit 35 to the motor 3 in response to the control signal from the processor. The motor 3 supplied with power rotates and generates a driving force controlled by the drive control unit 5.

[0054] <Drive control example> When at least a first preset condition is satisfied, the drive control unit 5 executes automatic control to control the vehicle speed only by the driving force of the motor 3. As a first example, the first condition may be that the vehicle speed reaches a set speed without acceleration only by the driving force of the motor 3 while an occupant is in the vehicle 10 and traveling. As a second example, the first condition may be that the pedaling force detected by the torque sensor 62 reaches a set condition.

[0055] In both the first and second examples, the drive control unit 5 executes normal assist control in which the motor 3 generates a driving force corresponding to the pedaling force when the pedaling force is being generated, until the first condition is satisfied. In other words, the drive control unit 5 prevents the motor 3 from generating a driving force when no pedaling force is being generated, until the first condition is satisfied. In this way, until the first condition is satisfied, the motor 3 is driven only when there is an input of human power (pedaling force), thereby controlling not to accelerate only by the driving force of the motor 3. In this case, the drive control unit 5 can determine that acceleration is not being performed only by the driving force of the motor 3 when the vehicle speed reaches the set vehicle speed or the torque reaches the set condition.

[0056] Also, for example, the set vehicle speed of the first condition can be set to a vehicle speed range that cannot be reached unless a passenger is riding and traveling (for example, a speed that cannot be reached while pushing the vehicle (for example, 10 km / h or more)). In this case, when the vehicle speed reaches the set vehicle speed, the drive control unit 5 can determine that the set vehicle speed has been reached while a passenger is riding and traveling. That is, it can be determined in a simple manner that the set vehicle speed has been reached with a passenger riding in the vehicle.

[0057] In the automatic control after the first condition is satisfied, the drive control unit 5 causes the motor 3 to generate a drive force even in a state where there is no pedal force, to maintain the vehicle speed or control the deceleration rate. In the automatic control, for example, in a state where there is no pedal force, the vehicle speed is controlled by the motor drive force within a range where the vehicle speed does not increase.

[0058] FIG. 3(a) is a diagram showing an example of normal assist control and automatic control by the drive control unit 5. In the graph of FIG. 3(a), the vertical axis indicates the vehicle speed V, and the horizontal axis indicates the travel distance D. In the example of FIG. 3(a), the drive control unit 5 executes normal assist control to output a driving force corresponding to the pedaling force to the motor 3 until the vehicle speed V increases from a state where the vehicle speed V is 0 by the rider pedaling and reaches the set vehicle speed Vs. After the vehicle speed exceeds the set vehicle speed Vs, when the rider stops pedaling, automatic control of the vehicle speed is started based on the vehicle speed V01 at that time. In FIG. 3(a), the line V shows an example of automatic control in the gradual decrease mode, and the dashed line V-2 shows an example of automatic control in the speed maintenance mode (constant speed mode). In the automatic control in the gradual decrease mode, the driving force of the motor 3 is controlled so that the degree of decrease in the vehicle speed becomes gentle during the period when no pedaling is performed. In the automatic control of the constant speed mode, the vehicle speed is controlled by the driving force of the motor 3 during the period when pedaling is not being performed so as to be maintained. This allows the distance traveled without pedaling after pedaling stops to be significantly longer than when there is no driving force of the motor 3. When the rider resumes pedaling during automatic control, the drive control unit 5 cancels the automatic control and transitions to normal assist control according to the pedaling force. Then, when the rider stops pedaling in a state where the vehicle speed exceeds the set vehicle speed Vs due to the rider's pedaling force and the driving force of the motor 3, automatic control of the vehicle speed is started based on the vehicle speed V02 (>Vs) at that time. Thereafter, similarly, the automatic control is cancelled, transitioned to normal assist control, and automatic control is executed based on the vehicle speed V03 (>Vs) from the time pedaling stopped.

[0059] In the example of FIG. 3(a), the vehicle speed of the vehicle 10 is gradually decreased or maintained during the period of automatic control while receiving the driving force of the motor 3. As a result, the coasting distance when the rider stops pedaling after pedaling hard to reach the set vehicle speed is significantly extended. Therefore, the rider can feel the exhilaration of the vehicle 10 running smoothly after pedaling. After reaching the set vehicle speed, the rider can maintain the vehicle speed range near the set speed with less pedaling force. This reduces the rider's fatigue while maintaining the vehicle speed, especially in the case of long-distance driving. Comfort and convenience are improved. In contrast, as shown in FIG. 3(b), when the automatic control is not performed and normal assist control is performed, the frequency and intensity of pedaling to maintain the vehicle speed are significantly increased compared to the example of FIG. 3(a). Also, in the example of FIG. 3(a), the fluctuation range of the vehicle speed is smaller than that in the example of FIG. 3(b). In this way, the combination of normal assist control and automatic control makes it possible to maintain the vehicle speed close to the set vehicle speed while suppressing the fluctuation range of the vehicle speed, thereby enabling efficient assistance of driving by the driving force of the motor 3.

[0060] FIG. 4 is a diagram showing another example of normal assist control and automatic control by the drive control unit 5. In the graph of FIG. 4, the vertical axis indicates vehicle speed V and pedaling force (torque) T, and the horizontal axis indicates travel distance D. In the example of FIG. 4, when the rider pedals from a state where vehicle speed V is 0, the pedaling force and vehicle speed increase, and when the pedaling force reaches a set level (set pedaling force Ts as an example), and the rider stops pedaling, automatic control of the vehicle speed is started based on the vehicle speed V0 at that time. In the automatic control, the driving force of the motor 3 is controlled so that the rate of decrease in the vehicle speed during a period when no pedaling is performed becomes gradual. When the rider resumes pedaling during the automatic control, the drive control unit 5 cancels the automatic control and switches to normal assist control according to the pedaling force. Then, when the rider's pedaling force T (for example, the peak or average value of the pedaling force in one pedal stroke) exceeds the set level (Ts) again and the rider stops pedaling, automatic control of the vehicle speed is started based on the vehicle speed V02 (>Vs) at that time. Thereafter, similarly, the automatic control is released, the control shifts to normal assist control, and automatic control is executed based on the vehicle speed V03 (>Vs) from the time pedaling stopped.

[0061] In the example of FIG. 4, the vehicle speed of the vehicle 10 is gradually reduced while receiving the driving force of the motor 3 during the period of automatic control. This significantly extends the coasting distance when the rider stops pedaling after pedaling hard and the pedaling force reaches the set level. Therefore, the rider can feel the exhilaration of the vehicle 10 running smoothly after pedaling. In addition, the rider can maintain running at a relatively high vehicle speed by repeatedly pedaling to increase the pedaling force to the set level in a short period of time. This reduces the rider's fatigue while maintaining the vehicle speed, especially in the case of long-distance running. Comfort and convenience are improved. In addition, by setting the pedaling force as the first condition as shown in FIG. 4, automatic control can be started in response to the rider's efforts in a situation where a certain amount of pedaling force is required, such as uphill running. The set level of the pedaling force is not limited to the set pedaling force Ts as in the example of FIG. 4, and may be, for example, a preset pedaling force speed (a rate of change in the pedaling force).

[0062] In the examples of FIG. 3(a) and FIG. 4, the automatic control of the vehicle speed is executed with the vehicle speed when pedaling stops after the first condition is satisfied as the reference vehicle speed. As a result, the vehicle speed that is the reference for the automatic control changes depending on the pedaling until the start of the automatic control. For example, the rider can increase the vehicle speed by pedaling after the set vehicle speed is reached and then stop pedaling. The greater the increase in vehicle speed, the longer the travel distance under the automatic control after pedaling stops. The rider can adjust the amount of increase in speed by pedaling to adjust the travel distance under the automatic control. The stop of pedaling can be determined by detecting at least one of the following: the stop of the pedal force input to the pedal based on the signal of the torque sensor 62, or the stop of the rotation of the crankshaft 41 (pedal 31) based on the signal of the crank rotation sensor 64.

[0063] In the examples of Figures 3(a) and 4, the condition for canceling the automatic control is that the rider's pedaling has been detected. As a result, the automatic control controls the vehicle speed by the driving force of the motor 3, independent of pedaling. Also, as in the above example, by switching from automatic control to normal assist control when pedaling is resumed, the rider can be motivated to resume pedaling if he or she wishes to increase the vehicle speed. Such motivation is a common feature and value of bicycles (vehicles that use pedaling force as a driving force). The rider can get the feeling that he or she is riding a bicycle, while also getting the feeling that is unique to automatic control, such as higher comfort, exhilaration, and ease of long-distance riding.

[0064] <Example of automatic control start conditions> In the example of FIG. 3(a), in addition to the first condition that the vehicle speed reaches the set vehicle speed Vs, pedaling cessation is added as a condition for starting automatic control. In the example of FIG. 4, in addition to the first condition that the pedaling force reaches a set level, pedaling cessation is added as a condition for starting automatic control. The condition for starting automatic control added to the first condition is not limited to this example. For example, automatic control may be started when the vehicle speed reaches the set vehicle speed Vs or when the pedaling force reaches a set level, without pedaling cessation being a condition. Also, for example, at least one of the following conditions may be added to the first condition as a condition for starting automatic control.

[0065] (Automatic control instructions by passengers) In addition to the first condition, an instruction operation of automatic control on an operator by an occupant may be added to the conditions for starting automatic control. For example, when the first condition is satisfied and an instruction operation of automatic control is performed by an occupant, the drive control unit 5 may start automatic control. The instruction operation of automatic control may be, for example, an operation on the operator 37 (button, lever, switch, etc.). For example, when the first condition is satisfied and the occupant performs an instruction operation on the operator 37 a predetermined number of times, the drive control unit 5 may start automatic control. In this case, automatic control may be executed based on the vehicle speed at the time of the instruction operation of automatic control. As an example, when the vehicle speed is equal to or higher than a set vehicle speed (V≧Vs), if the occupant presses the automatic control button once, automatic control may be started based on the vehicle speed at the time of pressing. Alternatively, when the vehicle speed is equal to or higher than a set vehicle speed (V≧Vs), if the occupant presses the automatic control button once, the automatic control standby state is entered, and when the automatic control button is pressed a second time, automatic control may be started based on the vehicle speed at that time.

[0066] (Brake release) In addition to the first condition, the condition for starting the automatic control may be added that the occupant is not applying the brakes, i.e., the brakes are released. This makes it possible to prevent the automatic control from being executed when the occupant is applying the brakes. For example, when the brake sensor 63 does not detect the brake operation, the drive control unit 5 can determine that the occupant is not applying the brakes.

[0067] (Vehicle speed is below the set upper limit) In addition to the first condition, the condition for starting automatic control may be added that the vehicle speed is equal to or lower than a set upper limit. This allows the drive control unit 5 to not execute automatic control when the vehicle speed exceeds the set upper limit. The upper limit of the vehicle speed may be set based on regulations such as laws and regulations.

[0068] <Examples of conditions for releasing automatic control> In the examples of Figures 3(a) and 4, detection of pedaling is the condition for canceling automatic control. The condition for canceling automatic control is not limited to this example. For example, at least one of the following conditions and pedaling detection may be the condition for canceling automatic control. Note that pedaling may be detected by at least one of detecting the force applied to the pedal based on a signal from the torque sensor 62, or detecting the rotation of the pedal 31 based on a signal from the crank rotation sensor 64.

[0069] (Brake detection) The drive control unit 5 may cancel the automatic control when a predetermined brake operation by the occupant is detected. For example, the automatic control may be canceled when the brake operation by the occupant is detected. Alternatively, the automatic control may be canceled when the brake operation by the occupant continues for a predetermined time or more. In this case, if the occupant applies the brakes for less than the predetermined time, the automatic control continues even after the vehicle is decelerated by the brake operation. This allows the occupant to adjust the vehicle speed during the automatic control by applying the brakes for less than the predetermined time.

[0070] (Automatic control release operation by passengers) The drive control unit 5 may release the automatic control when the occupant issues an instruction to release the automatic control to the operator. The instruction to release the automatic control may be, for example, an operation on the operator 37 (a button, a lever, a switch, etc.). The operator 37 that receives the instruction to release the automatic control may be the same as the operator that receives the instruction to release the automatic control, or may be different. For example, the automatic control may be released when a predetermined instruction to start the automatic control (for example, pressing a button a predetermined number of times) is issued to the same operator 37, followed by a predetermined release instruction (for example, pressing a button a predetermined number of times). Alternatively, the drive control unit 5 may continue the automatic control while the occupant continues the instruction to release the automatic control to the operator 37 (for example, while the occupant presses a button), and release the automatic control when the instruction to release the automatic control is completed (for example, when the occupant releases the button).

[0071] (Set duration has elapsed) The drive control unit 5 may cancel the automatic control when the set duration has elapsed since the start of the automatic control. The duration may be stored in the memory of the drive control unit 5. The duration may be a fixed value, or may be automatically updated according to the vehicle state (e.g., the remaining battery capacity, etc.). Alternatively, the occupant may be able to set the duration. For example, the duration may be determined according to the level of the remaining battery capacity (battery voltage), such as setting the duration of one automatic control to 60 seconds when the remaining battery capacity is 100 to 50%, and setting the duration to 30 seconds when the remaining battery capacity is less than 50%. Alternatively, the duration may be determined based on the amount of power consumed by the battery, such as setting the duration to the time until the power consumption of the battery due to the automatic control reaches a predetermined amount (e.g., 5% of the total battery capacity, etc.).

[0072] (Increasing vehicle speed) The drive control unit 5 may cancel the automatic control when an increase in the vehicle speed is detected during automatic control. For example, the automatic control may be canceled when an increase in the vehicle speed is detected during automatic control with pedaling stopped. For example, the vehicle speed may increase without pedaling when the vehicle 10 travels downhill during automatic control, or when the road changes from an uphill to a flat road during automatic control. In such a case, the drive control unit 5 can cancel the automatic control. In addition, the drive control unit 5 may cancel the automatic control when an increase in the vehicle speed is detected during automatic control, and may resume the automatic control if the duration of the increase in the vehicle speed is within the judgment time. In this case, the drive control unit 5 may detect the start of the increase in the vehicle speed and the end of the increase in the vehicle speed based on the signal of the vehicle speed sensor 61, and determine the duration of the increase in the vehicle speed.

[0073] (Vehicle speed reaches the upper limit) The drive control unit 5 may cancel the automatic control when it is detected that the vehicle speed has reached a set upper limit during automatic control. The drive control unit 5 may resume the automatic control when the vehicle speed exceeds the set upper limit and then decelerates to fall below the set upper limit.

[0074] (The vehicle speed reaches the lower limit) When it is detected that the vehicle speed reaches a lower limit value set during automatic control, the drive control unit 5 may cancel the automatic control. The lower limit value may be set to, for example, the lower limit of the vehicle speed range that is subject to automatic control.

[0075] (Disturbance detection) The drive control unit 5 may cancel the automatic control when a disturbance is detected. For example, the automatic control may be canceled when a disturbance is detected. Alternatively, the automatic control may be canceled when the detection of the disturbance continues for a predetermined time or more. Thereby, for example, when the vehicle 10 runs on a rough road such as a gravel road or a road with bumps or steps, the automatic control is canceled. The disturbance can be detected based on at least one signal of an acceleration sensor (G sensor, not shown) provided on the vehicle 10, the vehicle speed sensor 61, or the motor monitoring unit 54. As an example, the disturbance may be detected when the acceleration of the body frame 11 detected by the acceleration sensor exceeds a threshold value. The disturbance may also be detected when the time change of the vehicle speed or the time change of the motor output value exceeds a threshold value.

[0076] (Curve detection) The drive control unit 5 may cancel the automatic control when it is detected that the vehicle 10 is traveling on a curve. The detection of traveling on a curve can be detected, for example, based on at least one of a signal from a vehicle body motion sensor (not shown) or a signal from a steering angle sensor provided in the vehicle 10. The vehicle body motion sensor detects a change in the attitude of the vehicle body frame 11 of the vehicle 10 with respect to the road surface. For example, traveling on a curve may be detected when it is detected based on the signal from the vehicle body motion sensor that the vehicle 10 is traveling with the vehicle body frame 11 tilted at a predetermined angle or more from an upright state. The vehicle body motion sensor may include, for example, an angular velocity sensor about a plurality of axes of the vehicle body frame 11. The information of the vehicle body motion sensor may be, for example, a physical quantity related to any one of the yaw angle, roll angle, or pitch angle of the vehicle body. In addition to or instead of the vehicle body motion sensor detecting the attitude of the curve, traveling on a curve may be detected when the steering angle detected by the steering angle sensor is equal to or greater than a threshold value.

[0077] In the above example, when the first condition is the first example (set vehicle speed), the drive control unit 5 judges whether or not the first condition is satisfied based on the vehicle speed detected by the vehicle speed sensor 61. This is because, until the vehicle speed reaches the set vehicle speed, the motor 3 is controlled to apply driving force only when there is a pedaling force, and the set vehicle speed is set to the vehicle speed range during travel, so that it is possible to judge whether an occupant is in the vehicle 10 and traveling and there is no acceleration due to only the power of the motor 3 without directly detecting it. In contrast, at least one of these may be judged directly. For example, the drive control unit 5 may store in a memory history data of the pedaling force detected by the torque sensor 62 and the output of the driving force of the motor 3, and judge whether or not the set vehicle speed has been reached without the vehicle accelerating due only to the driving force of the motor based on the history data. The drive control unit 5 may also judge whether an occupant is in the vehicle 10 and traveling based on a signal from a pressure sensor (not shown) of the seat. In addition, in cases where the set vehicle speed is reached without accelerating the vehicle solely through the driving force of the motor, for example, the set vehicle speed may be reached solely through the occupant's pedaling force, or the set vehicle speed may be reached with the occupant's pedaling force and assistance from motor 3 to that pedaling force, or the set vehicle speed may be reached by driving downhill or in a tailwind.

[0078] In the example of FIG. 3(a), the determination of whether the vehicle speed has reached the set vehicle speed is made by comparing the detection value of the vehicle speed at the time of the determination with the set vehicle speed. As a modified example, the above determination may be made by comparing the average value, maximum value, or other representative value of the vehicle speed during a period including the time of the determination with the set vehicle speed. In the example of FIG. 4, the first condition is that the value indicating the magnitude of the detected pedal force has reached a set level. The first condition of the pedal force reaching the set level is not limited to this example. For example, the first condition may be that the magnitude of the pedal force or the rate of change of the pedal force (for example, a differential value) reaches a set value. In addition, the pedal force subject to the first condition may be the detection value of the pedal force at the time of the determination, or may be the average value, maximum value, or other representative value of the detection value of the pedal force during a period including the time of the determination. Since the pedal force pulsates, for example, the peak value or other representative value of the pedal force during each period of the pulsation, such as one cycle of the pedal, may be used as the value of the pedal force to determine whether the pedal force has reached the set level.

[0079] The first condition may be a combination of the condition related to the vehicle speed in Fig. 3(a) and the condition related to the pedal force in Fig. 4. For example, the first condition may be satisfied when either the vehicle speed reaches a set vehicle speed or the pedal force reaches a set level. Alternatively, the first condition may be satisfied when the vehicle speed reaches the set vehicle speed and the pedal force reaches a set level.

[0080] <Modifications of automatic control> In the above example, the drive control unit 5 controls the degree of reduction in the vehicle speed from the reference vehicle speed in the automatic control. That is, the drive control unit 5 executes control (gradual reduction control) to gradually reduce the vehicle speed from the reference vehicle speed while suppressing the degree of reduction in the vehicle speed by the motor driving force as the automatic control. In the examples of Fig. 3(a) and Fig. 4, the vehicle speed is controlled to decrease at a constant rate of change (time change). The manner in which the vehicle speed is gradually decreased is not limited to a linear decrease, and the rate of change in the vehicle speed may change depending on time, travel distance, or vehicle speed. In addition, the control of the vehicle speed by the motor 3 in the automatic control may be control to gradually decrease the output (e.g., motor torque) W of the motor 3, or control of the motor 3 to gradually decrease the vehicle speed.

[0081] In the automatic control, the drive control unit 5 may execute control to maintain a reference vehicle speed. In this case, the control of the vehicle speed by the motor 3 in the automatic control may be control to maintain the output (e.g., motor torque) W of the motor 3, or may be control of the motor 3 to maintain the vehicle speed.

[0082] In addition, in the automatic control, the drive control unit 5 may control the drive force of the motor 3 using the vehicle speed, motor output, and also the result of determining whether the vehicle is traveling uphill, downhill, or on a flat road based on a signal from an acceleration sensor.

[0083] <Example of automatic control processing> Fig. 5 is a flowchart showing an example of an automatic control process by the drive control unit 5. Fig. 6 is a flowchart showing an example of S8 (decrease mode output calculation) in Fig. 5. Fig. 7 is a flowchart showing another example of S8 (decrease mode output calculation) in Fig. 5.

[0084] In the example shown in FIG. 5, the conditions for starting the automatic control are (Condition 1) the automatic control switch ON (passenger's instruction operation), (Condition 2) the current vehicle speed Vn is greater than the set vehicle speed Vs (Vn>Vs), (Condition 3) pedaling stops, and (Condition 4) brake release. That is, in the process of FIG. 5, when the automatic control switch is ON (Yes in S1) and Vn>Vs (Yes in S2), the reference vehicle speed V0 is set to the current vehicle speed Vn (S3), and the reference motor output P0 is set to the most recent peak motor output Pn (S4). The automatic control switch in S1 may be a switch that switches between permission / prohibition of automatic control. In the example of FIG. 5, the automatic control switch may be a gradual decrease mode switch that switches between permission / prohibition of the gradual decrease mode.

[0085] Note that the reference motor output P0 is used as the initial value of the target value when automatic control is executed by control with the motor output value as the target value (motor output control, see Fig. 6). Therefore, when automatic control is executed by control with the vehicle speed as the target value (vehicle speed control, see Fig. 7), the process of S4 is unnecessary. Further, as a modification example, the reference motor output P0 may be set to the value of the average motor output in the most recent one rotation of the pedal.

[0086] Furthermore, when pedaling stops (Yes in S5) and the brake is released (Yes in S6), the drive control unit 5 sets the control mode to a deceleration mode which is an example of the automatic control mode (S7). The drive control unit 5 calculates the motor output in the deceleration mode (S8) and executes the motor output (S9). For example, in S8, for example, the target value of the motor output is calculated and the motor command value for approaching the motor output to the target value is calculated. In S9, the drive control unit 5 operates the motor 3 with the motor command value calculated in S8. For example, the drive control unit 5 supplies the motor command value to the motor drive unit 53 to drive the motor 3.

[0087] In the example of Fig. 5, the conditions for canceling (ending) automatic control are: (Condition 3') pedaling is being performed, (Condition 4') the brake is operating, and (Condition 7) the current vehicle speed Vn is less than the end vehicle speed (lower limit vehicle speed) VF (Vn < VF). That is, when pedaling is being performed or a brake operation is being performed (No in either S5 or S6), the control mode shifts from the deceleration mode to the normal assist control mode (S11). Also, when the start conditions for automatic control are not satisfied, that is, when automatic control is OFF or the set vehicle speed has not been reached (No in S1 or S2), the control mode is set to the normal assist control mode (S11).

[0088] In the normal assist control mode, the pedaling force (torque) Tn and the vehicle speed Vn are detected (S12). The drive control unit 5 calculates a motor torque command value according to the detected pedaling force Tn and vehicle speed Vn (S13), and based on the motor torque command value, causes the motor 3 to execute an output according to the command value (S14). In S13, for example, when the pedaling force Tn is 0, the command value is calculated so that the motor torque becomes 0. As a result, control is performed to apply the driving force of the motor 3 only when there is a pedaling force Tn.

[0089] Until the current vehicle speed Vn becomes less than the end vehicle speed (lower limit vehicle speed) VF (Yes in S10), the processes of S5 to S9 are repeatedly executed. When the current vehicle speed Vn becomes less than the end vehicle speed VF (Yes in S10), the process returns to S1 and is executed. The end vehicle speed VF is set to be less than the set vehicle speed Vs (VF < Vs). Therefore, after returning to S1 with Yes in S10 and then becoming No in S2, the control mode shifts to the normal assist control mode (S11).

[0090] FIG. 6 is a flowchart showing an example of the processing of the gradually decreasing mode output calculation (S8 in FIG. 5) when the motor output (motor torque) is set as the target value. In the example of FIG. 6, when the current vehicle speed V(n) is less than the previous vehicle speed V(n - 1) (V(n) > Vn - 1) and the current vehicle speed V(n) exceeds the reference vehicle speed V0 (V(n) > V0) (that is, when No in S21 and S22), the drive control unit 5 updates the target value of the motor output as the motor output control (S23). In S23, for example, the target value P(n) of the motor output is updated to a value lower than the previous target value P(n - 1) by a predetermined amount ΔP. Note that the initial value P(0) of the target value of the motor output may be the reference motor output P0. A motor command value I(n) for bringing the motor output closer to the target value P(n) is calculated (S24). In S24, for example, a command value for achieving the target value P(n) is calculated by PI control. The calculated motor command value I(n) is output as a return value (S25). The motor command value is, as an example, a motor current command value.

[0091] In the example of FIG. 6, when V(n)>V(n-1) or V(n)>V0, that is, when either S21 or S22 is Yes, the motor command value I(n)=0 is calculated (S26). In this case, the motor 3 is stopped. Thus, in the example of FIG. 6, the conditions for releasing the automatic control (interrupting the automatic control, i.e. stopping the motor) are set as follows: (Condition 5) the vehicle is in an accelerating state (V(n)>V(n-1)) and (Condition 6) the current vehicle speed V(n) is greater than the reference vehicle speed V0 of the automatic control (V(n)>V0). At the position A1 in FIG. 6, a process similar to the motor output control of S23 (P(n)=P(n-1)-ΔP) may be executed. The motor output to be controlled is not limited to the motor torque, and may be, for example, the motor rotation speed.

[0092] FIG. 7 is a flowchart showing an example of the process of the gradual decrease mode output calculation (S8 in FIG. 5) when the vehicle speed is the target value. In FIG. 7, the processes of S21, S22, and S25 may be executed in the same manner as in FIG. 6. In S23a, the drive control unit 5 updates the target value of the vehicle speed as the vehicle speed control process (S23). In S23a, for example, the target value V(n) of the vehicle speed is updated to a value lower than the previous target value V(n-1) by a predetermined amount ΔV. Note that the initial value V(0) of the target value of the vehicle speed may be the reference vehicle speed V0. In S24a, a motor command value I(n) for bringing the vehicle speed closer to this target value V(n) is calculated. In S24a, for example, a command value for achieving the target value V(n) is calculated by PI control. In the example of Fig. 7, as in Fig. 6, the conditions for canceling automatic control (interrupting automatic control) are set as (Condition 5) that the vehicle is in an accelerating state (V(n)>V(n-1)) and (Condition 6) that the current vehicle speed V(n) is greater than the reference vehicle speed V0 for automatic control (V(n)>V0). Also, at position A1 in Fig. 7, processing similar to the vehicle speed control of S23a (V(n)=V(n-1)-ΔV) may be executed.

[0093] <Modification of automatic control process> The automatic control process of the drive control unit 5 is not limited to the examples shown in FIGS. 5 to 7. For example, in S6 of FIG. 5, instead of determining the brake release (presence or absence of a brake operation), in addition to the presence or absence of a brake operation, the duration of the brake operation may further be determined. For example, in S6, it may be determined whether a brake operation is detected and whether the duration tB of the brake operation is shorter than a threshold ThB (tB < ThB). In this case, when a brake operation is detected and tB < ThB (when Yes in S6), the processes of S7 to S9 are executed. Thereby, as a condition for releasing the automatic control, it is set that the brake operation by the occupant continues for a predetermined time or longer.

[0094] In the example of FIG. 5, the reference motor output P0 in S4 is determined based on the motor output value. As a modification of this, the reference motor output P0 may be determined based on the motor output value and the pedal force. For example, the reference motor output P0 in S4 may be the sum of the peak of the most recent motor output and the peak of the pedal force. Or, P0 may be the sum of the average motor output value per one rotation of the most recent pedal and the average pedal force. When the sum is larger than the maximum output of the motor 3, the maximum output of the motor 3 can be used as the reference motor output P0. Thereby, the reference motor output P0 becomes larger. Therefore, in the automatic control, it is possible to start the vehicle speed gradual decrease control with a large motor output in a range where the motor 3 is not speeded up by the driving force.

[0095] By periodically and repeatedly executing the gradual decrease mode output calculation process shown in FIGS. 6 and 7, it is possible to decrease the motor output or the vehicle speed by a certain amount (ΔP, ΔV) per cycle, that is, per unit time. The mode of gradual decrease in the automatic control is not limited to such a linear decrease. For example, the target values of the motor output or the vehicle speed in S23 and S23a can be updated using map data indicating the way of gradual decrease. The map data may be, for example, data indicating the correspondence between the elapsed time or the traveling distance of the automatic control process and the target value. The map data may be stored in advance in the memory of the drive control unit 5.

[0096] In the example of FIG. 5, an occupant can instruct permission / prohibition of automatic control by turning on / off an automatic control switch, which is an example of an operator 37. As a modified example of the operator 37, an operator such as a switch, lever, or button for switching between a gradual decrease mode and a vehicle speed maintenance mode of the automatic control may be provided. As a process of the vehicle speed maintenance mode, for example, the control mode is set to the vehicle speed maintenance mode in S7 of FIG. 5, and an output calculation of the vehicle speed maintenance mode is executed in S8. The output calculation of the vehicle speed maintenance mode may be, for example, a process of calculating a motor command value such that the target value of the vehicle speed is set to a reference vehicle speed V0 and the vehicle speed becomes the target value. Alternatively, the output calculation of the vehicle speed maintenance mode may be a process of calculating a motor command value such that the motor output becomes the target value with the reference motor output P0 as the target value.

[0097] In the gradual decrease mode, the degree of decrease in the vehicle speed may be specified by the occupant. For example, the degree of decrease in the vehicle speed may be switchable between multiple stages or may be set steplessly by the operator 37. The drive control unit 5 sets ΔP in FIG. 6 or ΔV in FIG. 7 according to the degree of decrease in the vehicle speed specified by the occupant. As an example, if the degree of decrease in the vehicle speed is switchable between three stages, strong, medium, and weak, when strong is specified, ΔP=ΔP1, when medium, ΔP=ΔP2, and when weak, ΔP=ΔP3 (ΔP1<ΔP2<ΔP3).

[0098] <Example of automatic control pattern> FIG. 8 is a graph showing an example of the time change of the vehicle speed in the gradual decrease mode when the degree of decrease in the vehicle speed is set to strong, medium, and weak, respectively. The vertical axis of the graph represents the vehicle speed V, and the horizontal axis represents the traveling distance D. The solid line in the graph indicates the change in the vehicle speed when automatic control is executed, and the broken line K indicates, for reference, the change in the vehicle speed when coasting without motor driving force or pedaling from the vehicle speed at the start of automatic control. These graph displays are the same in FIGS. 9 to 11. FIG. 8 is an example when the vehicle 10 travels on a flat road. In the example shown in FIG. 8, the coasting distances d1, d2, and d3 due to the driving force of the motor 3 in the automatic control in the cases where the set degrees of decrease in the vehicle speed are weak, medium, and strong, respectively, are such that d1 < d2 < d3. The coasting distance is the distance that can be traveled without the occupant pedaling in the automatic control.

[0099] FIG. 9 is a graph showing an example of the time change of the vehicle speed when the vehicle 10 travels on a downhill slope during automatic control. In the example of FIG. 9, in the case of the steep downhill slope P1, since the vehicle speed increases, Yes (V(n)>V(n−1)) is obtained in S21 of FIGS. 6 and 7, and the motor is stopped (automatic control is interrupted). Alternatively, as a release condition of the automatic control, when the set upper limit vehicle speed is set, during the period when the vehicle speed becomes equal to or higher than the set upper limit vehicle speed on the downhill slope like P1 in FIG. 9, the motor can be stopped and the automatic control can be interrupted. In the case of the gentle downhill slope P2, the vehicle speed exceeds V0 and becomes constant (Yes in S22), and the motor is stopped (automatic control is interrupted). In the case of changing from the gentle downhill slope to the flat road P3, during the period of traveling on the flat road, No is obtained in S21 and S22, and the motor 3 is automatically controlled in the gradual decrease mode output. Incidentally, as a start condition of the automatic control, a threshold value of the downhill gradient may be set. The downhill gradient on which the vehicle 10 travels can be determined based on, for example, the signal of the acceleration sensor.

[0100] Fig. 10 is a graph showing an example of the change in vehicle speed over time when the vehicle 10 travels on a flat road, a downhill, and a flat road in that order during automatic control. In Fig. 10, in section k1 where the speed is increasing on the downhill and section k2 where the vehicle speed exceeds V0 on the flat road after the downhill, the answer is Yes in S21 and Yes in S22 in Fig. 6 and Fig. 7, respectively, and the motor is stopped. When the vehicle speed reaches the reference vehicle speed V0 on the flat road after the downhill, the automatic control of the gradual reduction mode output is resumed.

[0101] FIG. 11 is a graph showing an example of the change in vehicle speed over time when the vehicle 10 travels on a flat road, an uphill road, and a flat road in this order during automatic control. FIG. 11(a) is a graph in the case of the motor output control shown in FIG. 6. FIG. 11(b) is a graph in the case of the vehicle speed control shown in FIG. 7. In the example of FIG. 11(a), the degree of reduction in motor output is controlled on an uphill road in the same manner as on a flat road. Therefore, the degree of reduction in vehicle speed is greater on an uphill road than on a flat road. In the example of FIG. 11(b), the vehicle speed drops instantaneously at the start of the uphill road. The gradual reduction mode control is continued from the vehicle speed after the drop. If the vehicle speed increases instantaneously when the vehicle goes from an uphill road to a flat road, S21 in FIG. 7 becomes Yes and the motor is stopped. After that, when the vehicle speed starts to decrease, the motor drive in the gradual reduction mode is resumed. In the case of the vehicle speed control of FIG. 11(b), the coasting distance by the automatic control in the gradual reduction mode is longer than in the case of the motor output control of FIG. 11(a).

[0102] 9 to 11, even if an uphill road is replaced by a headwind, resistance of the road surface (rain, mud, sand, etc.), or other events that increase the running resistance, the same vehicle speed change pattern is obtained. Also, even if a downhill road is replaced by a tailwind, or other events that decrease the running resistance, the same vehicle speed change pattern is obtained.

[0103] The human-powered vehicle according to the embodiment of the present invention may be, in addition to an electrically assisted bicycle, an electric bicycle, a pedal-equipped electric motorcycle (electric moped), etc. Furthermore, the human-powered vehicle is not limited to a two-wheeled vehicle, and may be a vehicle having three or more wheels.

[0104] The embodiments of the present invention have been described above. However, the above-described embodiments are merely examples for carrying out the present invention. Therefore, the present invention is not limited to the above-described embodiment, and the scope of the present invention is not limited to the above-described embodiment. The above-described embodiment can be appropriately modified and implemented without departing from the scope of the present invention. [Explanation of symbols]

[0105] 3: motor, 5: drive control unit, 10: vehicle, 21: front wheels (wheels), 22: rear wheels (wheels), 31: pedal, 37a: operator, 61: vehicle speed sensor, 62: torque sensor, 63: brake sensor

Claims

1. A human-powered vehicle, Multiple wheels and a motor for supplying a driving force for at least one of the plurality of wheels; a pedal for inputting a pedal force of a rider to drive at least one of the plurality of wheels; A vehicle speed sensor for detecting a vehicle speed; A drive control unit that controls the drive of the motor, The drive control unit of this human-powered vehicle sets a first condition as to whether the vehicle speed detected by the vehicle speed sensor reaches a set speed without acceleration due solely to the power of the motor while the occupant is riding in the human-powered vehicle, and executes automatic control to control the vehicle speed using only the driving force of the motor when at least the first condition is satisfied.

2. Multiple wheels and a motor for supplying a driving force for at least one of the plurality of wheels; a pedal to which a pedal force is applied by a passenger to drive at least one of the plurality of wheels; a torque sensor for detecting the pedal force; A drive control unit that controls the drive of the motor, The drive control unit sets a first condition as a pedal force detected by the torque sensor reaching a set level, and when at least the first condition is satisfied, executes automatic control to control the vehicle speed using only the driving force of the motor.

3. 2. The human-powered vehicle according to claim 1, The human-powered vehicle, wherein the first condition is that the vehicle speed reaches the set speed at least by the pedaling force of the occupant.

4. 3. The human-powered vehicle according to claim 1 or 2, The automatic control is control to maintain a vehicle speed by a driving force of the motor, or control of a degree of reduction in the vehicle speed by the driving force of the motor.

5. 3. The human-powered vehicle according to claim 1 or 2, The drive control unit executes the automatic control when the first condition is satisfied and an operation to instruct automatic control is performed by the occupant.

6. 3. The human-powered vehicle according to claim 1 or 2, The drive control unit executes the automatic control when the first condition is satisfied and pedaling by the occupant against the pedal is stopped.

7. 3. The human-powered vehicle according to claim 1 or 2, The drive control unit cancels the automatic control when a cancellation condition is satisfied in the automatic control, The release condition includes at least one of detection of braking, detection of the force or rotation of the pedal, a release operation on an operator by a passenger, vehicle speed reaching a set upper limit, vehicle speed reaching a set lower limit, detection of an external disturbance, detection of an increase in vehicle speed, lapse of a set duration, or detection of driving around a curve.

8. 3. The human-powered vehicle according to claim 1 or 2, In the automatic control, the drive control unit controls the vehicle speed by setting the vehicle speed at the time when the pedaling of the occupant stops or the rotation of the pedal stops after the first condition is satisfied as a reference vehicle speed.

9. a plurality of wheels; a motor that supplies a driving force to at least one of the plurality of wheels; a pedal that inputs a pedaling force of a passenger to drive at least one of the plurality of wheels; and a vehicle speed sensor that detects a vehicle speed. A drive control device for controlling the drive of the motor of a human-powered vehicle comprising: A drive control device which sets a first condition as to whether the vehicle speed detected by the vehicle speed sensor reaches a set speed without acceleration due solely to the power of the motor while the occupant is driving the human-powered vehicle, and executes automatic control to control the vehicle speed using only the power of the motor when at least the first condition is satisfied.

10. A drive control device for controlling drive of the motor of a human-powered vehicle including a plurality of wheels, a motor for supplying a drive force for at least one of the plurality of wheels, a pedal for inputting a pedal force of a rider for driving at least one of the plurality of wheels, and a torque sensor for detecting the pedal force, A drive control device that sets a first condition as the pedal force detected by the torque sensor reaching a set level, and executes automatic control to control the vehicle speed using only the power of the motor when at least the first condition is satisfied.

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