Vehicle and vehicle control method

Abstract

To provide a vehicle which can properly assist based on user's acceleration intention.SOLUTION: An electric bicycle 10 includes: a crank pedal 79; a rear wheel 78; a motor M which drives the rear wheel 78; a control unit 40 which controls the motor M; an input torque acquisition unit 35 which acquires input torque; a cadence acquisition unit 39 which acquires cadence; and an acceleration acquisition unit 30 which acquires an acceleration. The control unit 40 allows the motor M to generate power when the input torque is higher than or equal to a first threshold value and the cadence is higher than or equal to a second threshold value or the acceleration is higher than or equal to a third threshold value.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a vehicle that can run using input from the legs of a passenger and power from an electric motor. and vehicle control method Regarding. [Background technology]

[0002] Electrically assisted bicycles, which use the power of an electric motor to assist pedal force input from the crank pedals, are known as vehicles that can travel using input from the rider's legs and power from an electric motor (see, for example, Patent Document 1). For electrically assisted bicycles, the upper limit of the assist force and the upper limit of the assist ratio relative to the vehicle speed are regulated by law. For example, Japanese laws stipulate the following:

[0003] "When a bicycle is ridden at a speed of less than 24 kilometers per hour, the ratio of the power of the motor to the power of the person must be equal to or less than the value specified in (1) or (2) according to the speed category set forth in (1) or (2). (1) Speeding less than 10 kilometers per hour: 2 (2) Speeds of 10 kilometers per hour or more but less than 24 kilometers per hour: The speed in kilometers per hour is subtracted by 10, the result is divided by 7, and the result is subtracted from 2.

[0004] That is, Japanese regulations require that the upper limit of the assist ratio relative to vehicle speed is 2 up to a vehicle speed of 10 km / h, as shown by the solid line in Figure 8, and that the assist ratio gradually decrease from 2 to 0 as the vehicle speed increases from 10 km / h to 24 km / h.

[0005] Furthermore, the electrically assisted bicycle described in Patent Document 1 is described as supplying a drive signal to the electric motor to generate power when the cadence is equal to or greater than a predetermined value and the acceleration is equal to or greater than a predetermined value. Cadence is the number of revolutions of the crank pedals per minute. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 08-268373 Summary of the Invention [Problem to be solved by the invention]

[0007] Cadence sensors typically detect cadence by detecting pulses generated as the crank rotates. However, detecting cadence requires detecting at least two pulses, which causes a delay in starting the motor for the time it takes to detect those pulses. This can result in a delayed response to the start of assist, potentially resulting in an unnatural start of assist that is not in line with the user's intentions.

[0008] On the other hand, although a large driving acceleration occurs immediately after starting to ride, it is often the case that a large driving acceleration does not occur during subsequent riding. Therefore, for example, when the user is cruising, even though the cadence exceeds a predetermined value, the driving acceleration does not exceed the predetermined value, and therefore, there may be a case where the user does not receive assistance even though they want assistance.

[0009] The present invention relates to a vehicle that can provide appropriate assistance based on the user's acceleration intention. and vehicle control method to provide. [Means for solving the problem]

[0010] No. 1 The invention is an input unit that receives input from the legs of an occupant; a wheel to which the power input to the input section is transmitted; an electric motor that transmits output power to the wheel or a wheel other than the wheel; a control unit that controls the electric motor; a first state quantity acquisition unit that acquires a first state quantity indicating the magnitude of the input; a second state quantity acquisition unit that acquires a second state quantity that indicates a speed of the motion of the input unit; A vehicle including a third state quantity acquisition unit that acquires a third state quantity indicating an acceleration of a vehicle body, the third state quantity acquisition unit includes an acceleration detector fixed to the vehicle body, the third state quantity acquisition unit further includes a correction unit that corrects the signal detected by the acceleration detector, The correction unit a second filtering unit that attenuates frequencies of the signal that are equal to or less than a sixth threshold; The control unit The first state quantity is equal to or greater than a first threshold value, and the second state quantity is equal to or greater than a second threshold value; Or, The first state quantity is equal to or greater than a first threshold value, and the third state quantity is equal to or greater than a third threshold value; When the motor is turned on, power generation is permitted. The second invention is as follows: an input unit that receives input from the legs of an occupant; a wheel to which the power input to the input section is transmitted; an electric motor that transmits output power to the wheel or a wheel other than the wheel, a first state quantity acquisition step of acquiring a first state quantity indicating the magnitude of the input; a second state quantity acquisition step of acquiring a second state quantity indicating a speed of the motion of the input unit; a third state quantity acquisition step of acquiring a third state quantity indicating an acceleration of the vehicle body; a drive permission determination step of determining whether to permit driving of the electric motor based on the first state quantity, the second state quantity, and the third state quantity, the third state quantity acquisition step includes a correction process of correcting a signal detected by an acceleration detector fixed to the vehicle body, The correction process includes: a second filtering step for attenuating frequencies of the signal below a sixth threshold; The drive permission determination step includes: the first state quantity is equal to or greater than a first threshold value, and the second state quantity is equal to or greater than a second threshold value; Or, the first state quantity is equal to or greater than a first threshold value, and the third state quantity is equal to or greater than a third threshold value; When the motor is turned on, power generation is permitted. The third invention is as follows: an input unit that receives input from the legs of an occupant; a wheel to which the power input to the input section is transmitted; an electric motor that transmits output power to the wheel or a wheel other than the wheel; a control unit that controls the electric motor; a first state quantity acquisition unit that acquires a first state quantity indicating the magnitude of the input; a second state quantity acquisition unit that acquires a second state quantity that indicates a speed of the motion of the input unit; A vehicle including a third state quantity acquisition unit that acquires a third state quantity indicating an acceleration of a vehicle body, the third state quantity acquisition unit includes an acceleration detector fixed to the vehicle body, the third state quantity acquisition unit further includes a correction unit that corrects the signal detected by the acceleration detector, The correction unit a first filtering unit that attenuates frequencies of the signal equal to or greater than a fifth threshold; The fifth threshold is a frequency when the time constant is 1.0 seconds. The fourth invention is as follows: an input unit that receives input from the legs of an occupant; a wheel to which the power input to the input section is transmitted; an electric motor that transmits output power to the wheel or a wheel other than the wheel, a first state quantity acquisition step of acquiring a first state quantity indicating the magnitude of the input; a second state quantity acquisition step of acquiring a second state quantity indicating a speed of the motion of the input unit; a third state quantity acquisition step of acquiring a third state quantity indicating an acceleration of the vehicle body; a drive permission determination step of determining whether to permit driving of the electric motor based on the first state quantity, the second state quantity, and the third state quantity, the third state quantity acquisition step includes a correction process of correcting a signal detected by an acceleration detector fixed to the vehicle body, The correction process includes: a first filtering process for attenuating frequencies of the signal equal to or greater than a fifth threshold; The fifth threshold value is the frequency when the time constant is 1.0 second.

[0011] Also, No. 5 The invention is an input unit that receives input from the legs of an occupant; a wheel to which the power input to the input section is transmitted; an electric motor that transmits output power to the wheel or a wheel other than the wheel; a control unit that controls the electric motor; a first state quantity acquisition unit that acquires a first state quantity indicating the magnitude of the input; a second state quantity acquisition unit that acquires a second state quantity that indicates a speed of the motion of the input unit; A vehicle including a third state quantity acquisition unit that acquires a third state quantity indicating an acceleration of a vehicle body, The control unit the first state quantity is equal to or greater than a first threshold value; The second state quantity is equal to or greater than a second threshold value, and permitting the electric motor to generate power when the third state quantity is less than a third threshold value; or the first state quantity is equal to or greater than a first threshold value; The second state quantity is less than a second threshold value, and When the third state quantity is equal to or greater than a third threshold value, the electric motor is permitted to generate power. The sixth invention is as follows: an input unit that receives input from the legs of an occupant; a wheel to which the power input to the input section is transmitted; an electric motor that transmits output power to the wheel or a wheel other than the wheel, a first state quantity acquisition step of acquiring a first state quantity indicating the magnitude of the input; a second state quantity acquisition step of acquiring a second state quantity indicating a speed of the motion of the input unit; a third state quantity acquisition step of acquiring a third state quantity indicating an acceleration of the vehicle body; a drive permission determination step of determining whether to permit driving of the electric motor based on the first state quantity, the second state quantity, and the third state quantity, The drive permission determination step includes: the first state quantity is equal to or greater than a first threshold value; The second state quantity is equal to or greater than a second threshold value, and permitting the electric motor to generate power when the third state quantity is less than a third threshold value; or the first state quantity is equal to or greater than a first threshold value; The second state quantity is less than a second threshold value, and When the third state quantity is equal to or greater than a third threshold value, the electric motor is permitted to generate power. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide appropriate assistance based on the user's intention to accelerate. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a side view of an electric bicycle 10. [Figure 2] 2 is a schematic diagram of a power transmission mechanism T including an electric assist unit 20. FIG. [Figure 3] FIG. 2 is a side view of the battery unit 4. [Figure 4] 2 is a diagram illustrating the electrical paths and communication paths of the power assist unit 20, the battery 2, and the control unit 40 in the electric bicycle 10. FIG. [Figure 5] FIG. 10 is a flowchart showing a flow of motor drive permission determination. [Figure 6] FIG. 2 is a functional block diagram of a control system for the electric bicycle 10. [Figure 7] 10 is a graph illustrating a filter 31 of the acceleration acquisition unit 30. [Figure 8] 1 is a graph showing the relationship between the assist ratio and the vehicle speed of an electrically assisted bicycle. DETAILED DESCRIPTION OF THE INVENTION

[0014] An electric bicycle will be exemplified below as an example of the vehicle of the present invention. As shown in Figure 1, the electric bicycle 10 is an electric assist bicycle that includes a front wheel 73, a rear wheel 78, a bicycle frame 67, an electric assist unit 20 that drives the rear wheel 78, and a battery unit 4 that is electrically connected to the electric assist unit 20, and is configured to be able to output the assist force generated by the electric assist unit 20.

[0015] The bicycle frame 67 comprises a head pipe 68 at the front end, a down pipe 69 extending downward from the head pipe 68 from the front to the rear of the vehicle body, a support pipe 66 (see Figure 2) fixed to the rear end of the down pipe 69 and extending to the left and right, a seat post 71 extending upward from the support pipe 66, and a pair of left and right rear forks 70 extending rearward from the support pipe 66.

[0016] A front fork 72 is steerably supported on the head pipe 68, and a front wheel 73 is journaled at the lower end of the front fork 72. A steering handlebar 74 is provided at the upper end of the front fork 72. The steering handlebar 74 is provided with an activation switch 5 for the electric assist unit 20 and a mobile terminal holder 6 for holding a mobile terminal 8 (see FIG. 4) owned by the user. A rear wheel 78 serving as a drive wheel is journaled between the rear ends of a pair of left and right rear forks 70 extending rearward from a seat post 71. A support shaft 75 with a seat 76 attached to the upper end thereof is attached to the seat post 71 so that the vertical position of the seat 76 can be adjusted.

[0017] A battery unit 4 that supplies power to the electric assist unit 20 is fixed to the front of the seat post 71 below the seat 76. To explain in more detail, the battery unit 4 has a base 3 attached to the front of the seat post 71, and a battery 2 is detachably held in the base 3. Details of the battery unit 4 will be described later.

[0018] A pair of crank pedals 79 are connected to the left and right ends of a crank shaft 83 that coaxially passes through the support pipe 66 of the bicycle frame 67. The pedaling force applied to the crank pedals 79 is transmitted to the crank shaft 83 and input to an endless chain 82 via a drive sprocket 80. The chain 82 is wound around the drive sprocket 80 and a driven sprocket 81 that is attached to the axle of the rear wheel 78.

[0019] Referring also to FIG. 2, the electric assist unit 20 is configured such that the motor M and crankshaft 83 are unitized and can be attached to the support pipe 66 of the bicycle frame 67 afterward.

[0020] In the electric assist unit 20, the output shaft 21 of the motor M and the crankshaft 83 are arranged in parallel inside the case 24. The crankshaft 83 is rotatably supported inside a cylindrical sleeve 26 via a first one-way clutch 28, and a driven gear 26a that meshes with the motor output gear 21a provided on the output shaft 21 of the motor M and a drive sprocket 80 are fixed to the outer periphery of this sleeve 26. Therefore, the torque of the motor M is transmitted to the drive sprocket 80 via the motor output gear 21a, the driven gear 26a, and the sleeve 26.

[0021] In addition, a second one-way clutch 29 is provided between the driven sprocket 81 and the rear wheel 78 .

[0022] In the electric bicycle 10 configured in this manner, when the crank pedal 79 is pedaled forward (also referred to as the forward rotation direction), the first one-way clutch 28 engages and the forward rotational power of the crankshaft 83 is transmitted to the drive sprocket 80 via the sleeve 26, and then to the driven sprocket 81 via the chain 82. At this time, the second one-way clutch 29 also engages, so that the forward rotational power transmitted to the driven sprocket 81 is transmitted to the rear wheel 78.

[0023] On the other hand, when the crank pedal 79 is pedaled in the reverse direction (also called the reverse rotation direction), the first one-way clutch 28 does not engage, the reverse rotational power of the crankshaft 83 is not transmitted to the sleeve 26, and the crankshaft 83 rotates freely.

[0024] Furthermore, when forward rotational power in the forward direction (forward rotation direction) is input from the rear wheel 78, such as when pushing the electric bicycle 10 forward, the second one-way clutch 29 does not engage, and the forward rotational power of the rear wheel 78 is not transmitted to the driven sprocket 81. As a result, the rear wheel 78 rotates relative to the driven sprocket 81. On the other hand, when reverse rotational power in the backward direction (reverse rotational direction) is input from the rear wheel 78, such as when pushing the electric bicycle 10 backward, the second one-way clutch 29 engages, and the reverse rotational power of the rear wheel 78 is transmitted to the driven sprocket 81 and then to the drive sprocket 80 via the chain 82. At this time, the first one-way clutch 28 is also engaged, and therefore the reverse rotational power transmitted to the drive sprocket 80 is transmitted to the crankshaft 83 and crank pedal 79, causing the crankshaft 83 and crank pedal 79 to rotate in the reverse direction.

[0025] The electric assist unit 20 is provided with a motor rotation speed sensor SE1 that detects the rotation speed of the motor M. The motor rotation speed sensor SE1 is composed of a magnet and a Hall IC that are provided on the outer periphery of the output shaft 21 of the motor M. In addition, a torque sensor SE2 is provided on the sleeve 26. The torque sensor SE2 constitutes an input torque acquisition unit 35 (see FIG. 6) that acquires input torque. The input torque indicates the magnitude of the force with which the rider presses the crank pedal 79 (hereinafter referred to as pedal force). The torque sensor SE2 is composed of a magnetic displacement detection torque sensor that is provided on the outer periphery of the sleeve 26. In a magnetic displacement detection torque sensor, a cantilever is displaced by torque, and the resulting displacement of the magnet at the tip is detected as a magnetic change by a Hall sensor facing the cantilever.

[0026] A rear wheel rotation speed sensor SE3 is provided on the rear wheel 78. The rear wheel rotation speed sensor SE3 constitutes a vehicle speed acquisition unit 37 (see FIG. 6) that acquires the speed of the electric bicycle 10 (hereinafter referred to as vehicle speed). The rear wheel rotation speed sensor SE3 is, for example, a magnetic detection sensor, and transmits magnetic pulses generated when magnets attached to the spokes of the rear wheel 78 pass the sensor as vehicle speed pulses to the control unit 40 (described later), which then calculates the vehicle speed from the pulse intervals. Generally, a single magnet is attached to the rear wheel 78, so a magnetic pulse is detected once per rotation of the rear wheel 78. For this reason, if vehicle speed No [km / h] is represented by the vehicle speed No [km / h] and circumference Ct [m] of the rear wheel 78, vehicle speed No [km / h] can be expressed by the following equation (1):

[0027] No [km / h] = {Ct [m] / magnetic pulse interval (s)} × 3600 / 1000 (1)

[0028] A cadence sensor SE4 (see FIG. 2) is attached around the drive sprocket 80. Because the drive sprocket 80 rotates integrally with the crank pedal 79 when the first one-way clutch 28 is engaged, the rotation of the drive sprocket 80 can be considered as the rotation of the crank pedal 79. Therefore, the cadence sensor SE4 constitutes the cadence acquisition unit 39 (see FIG. 6), which acquires the cadence, which indicates the speed of rotation (movement) of the crank pedal 79. The cadence sensor SE4 is, for example, a magnetic detection sensor. The drive sprocket 80 has eight magnets evenly spaced around its circumference. The cadence sensor SE4 transmits magnetic pulses generated when the magnets pass the sensor as cadence pulses (cadence-related information) to the control unit 40 (described later). The control unit 40 calculates the cadence from the pulse intervals. The cadence pulses are detected eight times per rotation of the crank pedal 79. Therefore, the cadence C [rpm] is expressed by the following equation (2):

[0029] C [rpm] = {1 / (8 × magnetic pulse interval (s))} × 60 (2)

[0030] 6, the control unit 40 that controls the electric assist unit 20 calculates the force with which the rider presses the crank pedal 79 (hereinafter referred to as pedal force) from the input torque, which is the output value of the torque sensor SE2, and PWM controls the motor M to generate an assist force determined by this pedal force and an assist ratio according to the vehicle speed of the electric bicycle 10. The drive permission conditions for the motor M will be described later.

[0031] The control unit 40 may be incorporated into the electric assist unit 20 or may be incorporated inside the battery unit 4. In this embodiment, the case where the control unit 40 is incorporated into the battery unit 4 will be described as an example.

[0032] 3, the battery unit 4 includes a base 3 attached to the seat post 71, and a battery 2 having a plurality of cells therein that is detachably attached to the base 3. The base 3 includes a first space SP1 therein and a second space SP2 that is partitioned liquid-tightly from the first space SP1.

[0033] FIG. 4 is a diagram illustrating the electrical paths and communication paths of the power assist unit 20, the battery 2, and the control unit 40 in the electric bicycle 10.

[0034] The second space SP2 of the base 3 is arranged with a control unit 40 (PROCESSOR in the figure), a DC / DC converter, an inertial measurement unit IMU (Inertial Measurement Unit), an atmospheric pressure sensor 41, a GPS (Global Positioning system), a memory 42 (memory card in the figure), and BLE (Bluetooth Low Energy).

[0035] As described above, the control unit 40 calculates the torque to be generated by the motor M of the electric assist unit 20 so as to generate an assist force determined by the pedaling force and an assist ratio corresponding to the vehicle speed of the electric bicycle 10. As a result, the motor M operates in accordance with the calculation result (drive request) from the control unit 40. The converter DC / DC steps down the supplied DC voltage while keeping it as DC, and generates power supply voltages for the control unit 40, inertial measurement unit IMU (Inertial Measurement Unit), atmospheric pressure sensor 41, GPS (Global Positioning System), memory 42, and BLE (Bluetooth Low Energy). Note that power supply lines connecting the converter DC / DC to the inertial measurement unit IMU, atmospheric pressure sensor 41, GPS, memory 42, and BLE are omitted from FIG. 4.

[0036] The inertial measurement unit IMU is, for example, a nine-axis sensor that combines the functions of a three-axis acceleration sensor, a three-axis angular velocity sensor, and a three-axis direction sensor. The inertial measurement unit IMU constitutes an acceleration acquisition unit 30 (see FIG. 6) that acquires the acceleration of the electric bicycle 10. Using the inertial measurement unit IMU, the control unit 40 can grasp the driving acceleration, which is the acceleration in the forward direction of the electric bicycle 10, as well as the attitude (leaning state) of the electric bicycle 10.

[0037] The atmospheric pressure sensor 41 detects atmospheric pressure. The GPS acquires location information of the electric bicycle 10. The memory is, for example, an SD card, and temporarily or permanently stores information about the electric bicycle 10, riding data, etc. The BLE is a communication device for communicating with the user's mobile terminal 8. These control unit 40 and other components are arranged in a liquid-tight partitioned second space SP2, preventing water from entering even in bad weather.

[0038] In the first space SP1 of the base 3, there are arranged a second electrical connector 12 electrically connected to a first electrical connector 11 provided on the battery 2 via a power line 51, a third electrical connector 13 electrically connected to the control unit 40 via a power line 52 and a converter DC / DC, a fourth electrical connector 14 electrically connected to the control unit 40 via a signal line 53, and a communication connector 15 communicatively connected to the control unit 40 via a communication line 54.

[0039] The second electrical connector 12 is connected to the battery 2 via a power line 51, and is connected to the electric assist unit 20 via a power line 55. The third electrical connector 13 is connected to a DC / DC converter via a power line 52, and is connected to the electric assist unit 20 via a power line 56. The power line 56 is configured to receive power from the battery 2 by branching from the power line 55, for example. The fourth electrical connector 14 is connected to the control unit 40 via a signal line 53, and is connected to the electric assist unit 20 via a signal line 57. The communication connector 15 is connected to the control unit 40 via a communication line 54, and is connected to the electric assist unit 20 via a communication line 58. The communication method via the communication lines 54, 58 is not particularly limited, but may be, for example, UART (Universal Asynchronous Receiver Transmitter) communication.

[0040] The second electrical connector 12 is, for example, a connector. The third electrical connector 13, the fourth electrical connector 14, and the communication connector 15 form a single connector 16. The power line 52, the signal line 53, and the communication line 54 form a first harness 59, and the power line 56, the signal line 57, and the communication line 58 form a second harness 60.

[0041] In the electrical system and communication system configured as described above, power from the battery 2 is supplied to the motor M of the electric assist unit 20, and power stepped down from the electric assist unit 20 via the DC / DC converter is supplied to the control unit 40, the inertial measurement unit IMU, the atmospheric pressure sensor 41, GPS, memory, and BLE. When power is supplied to the control unit 40 and the user issues a start-up request for the electric assist unit 20 via the start-up switch 5, a power-on signal is sent to the electric assist unit 20 via signal lines 53 and 57, and the electric assist unit 20 starts up. When the electric assist unit 20 starts up, information is exchanged between the electric assist unit 20 and the control unit 40 via communication lines 54 and 58, and information can also be exchanged with the user's mobile device via BLE.

[0042] <Motor drive permission conditions> As shown in Figure 6, the control unit 40 acquires the input torque detected by the torque sensor SE2. The control unit 40 receives a vehicle speed pulse as vehicle speed-related information from the rear wheel rotation speed sensor SE3 and acquires the vehicle speed of the electric bicycle 10 from the above equation (1). The control unit 40 receives a cadence pulse as cadence-related information from the cadence sensor SE4 and acquires the cadence from the above equation (2). The control unit 40 acquires the acceleration (driving acceleration) of the electric bicycle 10 from the inertial measurement unit IMU. The control unit 40 then determines whether or not to permit motor torque generation based on the input torque, vehicle speed, cadence, and acceleration.

[0043] The control unit 40 allows the motor M to generate torque when the input torque is equal to or greater than a first threshold, and the cadence is equal to or greater than a second threshold, or the acceleration of the electric bicycle 10 is equal to or greater than a third threshold. More specifically, the control unit 40 allows the motor M to generate torque when the following conditions (A) to (C) are met:

[0044] (A) The input torque is equal to or greater than the first threshold, the cadence is equal to or greater than the second threshold, and the acceleration of the electric bicycle 10 is equal to or greater than the third threshold.

[0045] (B) The input torque is equal to or greater than the first threshold, the cadence is equal to or greater than the second threshold, and the acceleration of the electric bicycle 10 is less than the third threshold.

[0046] (C) The input torque is equal to or greater than the first threshold, the cadence is less than the second threshold, and the acceleration of the electric bicycle 10 is equal to or greater than the third threshold.

[0047] In (A) to (C), the existence of a predetermined input torque is a condition because, as explained using Figure 8, regulations prescribe the assist ratio based on the existence of a pedaling force applied to the crank pedal 79.

[0048] Condition (A) is the same as the conventional method. However, as mentioned above, condition (A) may cause a delay in response when assisting begins, or may result in situations where assistance is not provided in accordance with the user's wishes, or where assistance is not provided as the user wishes.

[0049] Therefore, the control unit 40 allows the generation of motor torque even under the conditions (B) and (C). According to condition (B), it is sufficient that input torque is present and a predetermined cadence is generated. Therefore, even if the acceleration of the electric bicycle 10 does not reach a predetermined value, such as when the user is cruising, appropriate assistance can be provided if the user desires assistance.

[0050] According to condition (C), as long as input torque is present and a predetermined acceleration is occurring in the electric bicycle 10, motor torque can be generated before two pulses are detected by the rotation of the crank pedals 79 (drive sprocket 80). In other words, conventionally, the generation of cadence was a necessary condition for generating motor torque, which required waiting the pulse detection time required to detect two pulses. This resulted in a response delay in the start of assist, potentially resulting in an unnatural start of assist that did not conform to the user's intention. However, by not requiring the generation of cadence, it is possible to provide appropriate assistance based on the user's intention to accelerate. Note that the control unit 40 does not need to adopt both conditions (B) and (C) as motor drive permission conditions; it may adopt only one of them.

[0051] Further, the control unit 40 does not permit the generation of motor torque under the following conditions (D) and (E), as in the conventional case.

[0052] (D) The input torque is less than the first threshold.

[0053] (E) The input torque is equal to or greater than the first threshold, the cadence is less than the second threshold, and the acceleration of the electric bicycle 10 is less than the third threshold.

[0054] Furthermore, the control unit 40 prohibits the generation of motor torque under the following condition (F).

[0055] (F) The speed of the electric bicycle 10 is equal to or greater than the fourth threshold.

[0056] Under Japanese regulations, the fourth threshold is 24 km / h. By prohibiting the generation of motor torque when the vehicle speed is high, unnecessary assistance can be prevented. It also helps to avoid non-compliance with regulations.

[0057] FIG. 5 is a flow diagram showing a flow of motor drive permission determination. The control unit 40 first determines whether the input torque is equal to or greater than a first threshold (S1). If the input torque is less than the first threshold (NO in S1), motor torque generation is not permitted (S5). On the other hand, if the input torque is equal to or greater than the first threshold (YES in S1), the control unit 40 then determines whether the vehicle speed is less than 24 km / h (S2). If the vehicle speed is equal to or greater than 24 km / h (NO in S2), motor torque generation is not permitted (S5). On the other hand, if the vehicle speed is less than 24 km / h (YES in S2), the control unit 40 then determines whether the cadence is equal to or greater than a second threshold (S3). If the cadence is equal to or greater than the second threshold (YES in S3), motor torque generation is permitted (S6). On the other hand, if the cadence is less than the second threshold (NO in S3), the control unit 40 then determines whether the acceleration is equal to or greater than a third threshold (S4). If the acceleration is equal to or greater than the third threshold (YES in S4), motor torque generation is permitted (S6). On the other hand, if the acceleration is less than the third threshold (NO in S4), motor torque generation is not permitted (S5). Note that the order of S3 and S4 may be reversed. Furthermore, if there are no legal restrictions on vehicle speed, the process of S2 may be omitted.

[0058] <Calibration> The control unit 40 calibrates the inertial measurement unit IMU based on the attitude (inclination state) of the electric bicycle 10 detected by the inertial measurement unit IMU. Calibration is performed when the electric bicycle 10 is placed horizontally and stationary. This improves the detection accuracy of the inertial measurement unit IMU.

[0059] Prior to calibration, the mounting orientation of the control unit 40 is input in advance, and initial settings are made so that coordinate conversion processing is performed appropriately according to the mounting orientation. For example, if the electric bicycle 10 is sold as a finished product, the initial settings may be made at a manufacturing factory, a dealer, or the like, and if the electric bicycle 10 is an electric conversion of an existing non-electric bicycle, the initial settings may be made at a repair factory, a dealer, or the like where the power assist unit 20 is assembled onto the non-electric bicycle.

[0060] The calibration is preferably performed automatically when the start switch 5 of the electric assist unit 20 is pressed. More specifically, when the user presses the start switch 5 of the electric assist unit 20 while riding, the control unit 40 detects an onboard angle correction value based on the direction of gravitational acceleration. The control unit 40 obtains the corrected acceleration by using the onboard angle correction value for the acceleration obtained from the inertial measurement unit IMU.

[0061] It should be noted that calibration does not need to be performed automatically, and may be performed manually at a manufacturing factory, a repair factory, a dealer, etc. In this case, a calibration command signal is sent via UART communication connected to the control unit 40, wireless communication, etc.

[0062] As shown in FIG. 6, the acceleration acquisition unit 30 includes an inertial measurement unit (IMU) and a filter 31 that corrects the signal detected by the inertial measurement unit (IMU). The filter 31 preferably includes a first filter 32 that attenuates frequencies equal to or greater than a fifth threshold in the signal detected by the inertial measurement unit (IMU). The first filter 32 is a so-called low-pass filter (high-cut filter). The fifth threshold is, for example, the frequency when the time constant is 1.0 second. This makes it possible to suppress detection errors by removing the DC component or low-frequency component of the acceleration signal.

[0063] Furthermore, the filter 31 preferably includes a second filter 33 that attenuates frequencies equal to or lower than a sixth threshold in the signal detected by the inertial measurement unit (IMU). The second filter 33 is a so-called high-pass filter (low-cut filter). The sixth threshold is, for example, a frequency when the time constant is 0.5 seconds. This makes it possible to remove noise and sudden error values ​​from the inertial measurement unit (IMU), thereby suppressing detection errors. As shown in FIG. 7, the filter 31 can detect frequency components with a time constant of 0.5 seconds to 1.0 seconds, further improving the detection accuracy of the inertial measurement unit (IMU).

[0064] The electric bicycle 10 is not limited to a particular type and may be a road bike, mountain bike, cross bike, city bike, folding bicycle, or the like. The battery unit 4 is not limited to being placed in front of the seat post 71, but may be placed in any position, such as the rear of the seat post 71, the upper surface of the down pipe 69, or the lower surface of the down pipe 69. For example, in the case of a road bike, mountain bike, cross bike, or the like, the battery unit 4 may be placed on the upper surface of a top pipe connecting the head pipe and seat post above the down pipe, or on the lower surface of the top pipe.

[0065] Although various embodiments have been described above with reference to the drawings, it goes without saying that the present invention is not limited to such examples. It is clear that a person skilled in the art can conceive of various modifications or alterations within the scope of the claims, and it is understood that these also naturally fall within the technical scope of the present invention. Furthermore, the components of the above-described embodiments may be combined in any manner without departing from the spirit of the invention.

[0066] In the above embodiment, the electric assist unit 20 drives the rear wheels 78, but it may also drive the front wheels 73.

[0067] This specification also describes at least the following: Note that the components in parentheses correspond to those in the above-described embodiment, but are not limited to these.

[0068] (1) an input unit (crank pedal 79) that receives input from the legs of the occupant; a wheel (rear wheel 78) to which the power input to the input section is transmitted; an electric motor (motor M) that transmits output power to the wheels or other wheels (front wheels 73) different from the wheels; a control unit (control unit 40) that controls the electric motor; a first state quantity acquisition unit (input torque acquisition unit 35) that acquires a first state quantity (input torque related information) that indicates the magnitude of the input; a second state quantity acquisition unit (cadence acquisition unit 39) that acquires a second state quantity (cadence-related information) that indicates the speed of the motion of the input unit; a third state quantity acquisition unit (acceleration acquisition unit 30) that acquires a third state quantity (acceleration-related information) that indicates the acceleration of the vehicle body; The control unit The first state quantity is equal to or greater than a first threshold value, and the second state quantity is equal to or greater than a second threshold, or the third state quantity is equal to or greater than a third threshold, When the vehicle is in a stopped state, the electric motor is permitted to generate power.

[0069] According to (1), when the first state quantity is equal to or greater than the first threshold, the second state quantity is equal to or greater than the second threshold, or the third state quantity is equal to or greater than the third threshold, the control unit allows the electric motor to generate power, thereby enabling appropriate assistance to be provided based on the user's intention to accelerate.

[0070] (2) The vehicle according to (1), Further provided is a fourth state quantity acquisition unit (vehicle speed acquisition unit 37) that acquires a fourth state quantity (vehicle speed related information) that indicates the speed of the vehicle, The control unit When the fourth state quantity is equal to or greater than a fourth threshold value, the electric motor is prohibited from generating power.

[0071] According to (2), unnecessary assistance can be prevented by prohibiting the electric motor from generating power when the vehicle is traveling at high speed.

[0072] (3) A vehicle according to (1) or (2), The third state quantity acquisition unit includes an acceleration detector (inertial measurement unit IMU) fixed to the vehicle body.

[0073] According to (3), it is possible to grasp the vehicle's posture in addition to the forward acceleration using an acceleration detector fixed to the vehicle body.

[0074] (4) A vehicle as described in (3), A vehicle, wherein the acceleration detector is calibrated when the vehicle is placed horizontally and stationary.

[0075] According to (4), the detection accuracy of the acceleration detector is improved.

[0076] (5) A vehicle as set forth in (3) or (4), The third state quantity acquisition unit further includes a correction unit (filter 31) that corrects the signal detected by the acceleration detector.

[0077] According to (5), the detection accuracy of the acceleration detector is further improved.

[0078] (6) A vehicle as described in (5), The correction unit The vehicle includes a first filtering unit (first filter 32) that attenuates frequencies of the signal that are equal to or greater than a fifth threshold.

[0079] Generally, an acceleration detector may have a detection error called drift, but according to (6), the detection error can be suppressed by removing the DC component or low-frequency component of the acceleration signal.

[0080] (7) A vehicle as described in (6), The fifth threshold value is a frequency when the time constant is 1.0 second.

[0081] According to (7), detection errors can be suppressed by removing the DC component or low frequency component of the acceleration signal.

[0082] (8) A vehicle according to any one of (5) to (7), The correction unit The vehicle includes a second filtering unit (second filter 33) that attenuates frequencies of the signal that are equal to or lower than a sixth threshold.

[0083] According to (8), the detection error can be suppressed by removing noise and sudden error values ​​of the acceleration detector.

[0084] (9) A vehicle according to (8), The sixth threshold is a frequency when the time constant is 0.5 seconds.

[0085] According to (9), the detection error can be suppressed by removing noise and sudden error values ​​of the acceleration detector.

[0086] (10) an input unit (crank pedal 79) for receiving input from the legs of the occupant; a wheel (rear wheel 78) to which the power input to the input section is transmitted; an electric motor (motor M) that transmits output power to the wheels or other wheels (front wheels 73) different from the wheels; a control unit (control unit 40) that controls the electric motor; a first state quantity acquisition unit (input torque acquisition unit 35) that acquires a first state quantity (input torque related information) that indicates the magnitude of the input; a second state quantity acquisition unit (cadence acquisition unit 39) that acquires a second state quantity (cadence-related information) that indicates the speed of the motion of the input unit; a third state quantity acquisition unit (acceleration acquisition unit 30) that acquires a third state quantity (acceleration-related information) that indicates the acceleration of the vehicle body; The control unit the first state quantity is equal to or greater than a first threshold value; The second state quantity is equal to or greater than a second threshold value, and permitting the electric motor to generate power when the third state quantity is less than a third threshold value; or the first state quantity is equal to or greater than a first threshold value; The second state quantity is less than a second threshold value, and When the third state quantity is equal to or greater than a third threshold value, the electric motor is permitted to generate power.

[0087] According to (10), the control unit allows the electric motor to generate power under specified conditions even if all of the first state quantity, the second state quantity, and the third state quantity do not satisfy the threshold value, so that appropriate assistance can be provided based on the user's intention to accelerate.

[0088] (11) A vehicle according to (10), The control unit the first state quantity is equal to or greater than the first threshold value; The second state quantity is equal to or greater than the second threshold value, and permitting the electric motor to generate power when the third state quantity is less than the third threshold value; and the first state quantity is equal to or greater than the first threshold value; the second state quantity is less than the second threshold value, and The vehicle allows the electric motor to generate power when the third state quantity is equal to or greater than the third threshold value.

[0089] According to (11), assistance can be provided more appropriately based on the user's intention to accelerate. [Explanation of symbols]

[0090] 10 Electric bicycle (vehicle) 30 Acceleration acquisition unit (third state quantity acquisition unit) 31 Filter (correction section) 32 First filter (first filtering section) 33 Second filter (second filtering section) 35 Input torque acquisition unit (first state quantity acquisition unit) 37 Vehicle speed acquisition unit (fourth state quantity acquisition unit) 39 Cadence acquisition unit (second state quantity acquisition unit) 40 Control Unit 73 Front wheels (other wheels) 78 Rear wheel (wheel) 79 Crank pedal (input part) M motor (electric motor) IMU Inertial Measurement Unit (accelerometer)

Claims

1. an input unit that receives input from the legs of an occupant; a wheel to which the power input to the input section is transmitted; an electric motor that transmits output power to the wheel or a wheel other than the wheel; a control unit that controls the electric motor; a first state quantity acquisition unit that acquires a first state quantity indicating the magnitude of the input; a second state quantity acquisition unit that acquires a second state quantity that indicates a speed of the motion of the input unit; a third state quantity acquisition unit that acquires a third state quantity indicating an acceleration of a vehicle body, the third state quantity acquisition unit includes an acceleration detector fixed to the vehicle body, the third state quantity acquisition unit further includes a correction unit that corrects the signal detected by the acceleration detector, The correction unit a second filter unit that attenuates frequencies of the signal that are equal to or less than a sixth threshold; The control unit the first state quantity is equal to or greater than a first threshold value, and the second state quantity is equal to or greater than a second threshold value; Or, the first state quantity is equal to or greater than a first threshold value, and the third state quantity is equal to or greater than a third threshold value; When the vehicle is in a stopped state, the electric motor is permitted to generate power.

2. 2. The vehicle according to claim 1, a fourth state quantity acquisition unit that acquires a fourth state quantity that indicates a speed of the vehicle; The control unit When the fourth state quantity is equal to or greater than a fourth threshold value, the electric motor is prohibited from generating power.

3. 3. A vehicle according to claim 1 or 2, A vehicle, wherein the acceleration detector is calibrated when the vehicle is placed horizontally and stationary.

4. A vehicle according to any one of claims 1 to 3, The correction unit The vehicle includes a first filter that attenuates frequencies of the signal that are equal to or greater than a fifth threshold.

5. 5. The vehicle according to claim 4, The fifth threshold value is a frequency when the time constant is 1.0 seconds.

6. A vehicle according to any one of claims 1 to 5, The sixth threshold is a frequency when the time constant is 0.5 seconds.

7. an input unit that receives input from the legs of an occupant; a wheel to which the power input to the input section is transmitted; an electric motor that transmits output power to the wheel or a wheel other than the wheel; a control unit that controls the electric motor; a first state quantity acquisition unit that acquires a first state quantity indicating the magnitude of the input; a second state quantity acquisition unit that acquires a second state quantity that indicates a speed of the motion of the input unit; a third state quantity acquisition unit that acquires a third state quantity indicating an acceleration of a vehicle body, The control unit the first state quantity is equal to or greater than a first threshold value; The second state quantity is equal to or greater than a second threshold value, and permitting the electric motor to generate power when the third state quantity is less than a third threshold value; or the first state quantity is equal to or greater than a first threshold value; The second state quantity is less than a second threshold value, and When the third state quantity is equal to or greater than a third threshold value, the electric motor is permitted to generate power.

8. 8. A vehicle according to claim 7, The control unit the first state quantity is equal to or greater than the first threshold value; The second state quantity is equal to or greater than the second threshold value, and permitting the electric motor to generate power when the third state quantity is less than the third threshold value; and the first state quantity is equal to or greater than the first threshold value; the second state quantity is less than the second threshold value, and The vehicle allows the electric motor to generate power when the third state quantity is equal to or greater than the third threshold value.

9. An input unit that receives input from the legs of an occupant; a wheel to which the power input to the input section is transmitted; an electric motor that transmits output power to the wheel or a wheel other than the wheel; a control unit that controls the electric motor; a first state quantity acquisition unit that acquires a first state quantity indicating the magnitude of the input; a second state quantity acquisition unit that acquires a second state quantity that indicates a speed of the motion of the input unit; a third state quantity acquisition unit that acquires a third state quantity indicating an acceleration of a vehicle body, the third state quantity acquisition unit includes an acceleration detector fixed to the vehicle body, the third state quantity acquisition unit further includes a correction unit that corrects the signal detected by the acceleration detector, The correction unit a first filtering unit that attenuates frequencies of the signal equal to or greater than a fifth threshold; The fifth threshold is a frequency when the time constant is 1.0 seconds. vehicle.

10. An input unit that receives input from the legs of an occupant; a wheel to which the power input to the input section is transmitted; an electric motor that transmits output power to the wheel or a wheel other than the wheel, a first state quantity acquisition step of acquiring a first state quantity indicating the magnitude of the input; a second state quantity acquisition step of acquiring a second state quantity indicating a speed of the motion of the input unit; a third state quantity acquisition step of acquiring a third state quantity indicating an acceleration of the vehicle body; a drive permission determination step of determining whether to permit driving of the electric motor based on the first state quantity, the second state quantity, and the third state quantity, the third state quantity acquisition step includes a correction process of correcting a signal detected by an acceleration detector fixed to the vehicle body, The correction process includes: a second filtering step for attenuating frequencies of the signal below a sixth threshold; The drive permission determination step includes: the first state quantity is equal to or greater than a first threshold value, and the second state quantity is equal to or greater than a second threshold value; Or, the first state quantity is equal to or greater than a first threshold value, and the third state quantity is equal to or greater than a third threshold value; When the vehicle is in a stopped state, the electric motor is permitted to generate power.

11. An input unit that receives input from the legs of an occupant; a wheel to which the power input to the input section is transmitted; an electric motor that transmits output power to the wheel or a wheel other than the wheel, a first state quantity acquisition step of acquiring a first state quantity indicating the magnitude of the input; a second state quantity acquisition step of acquiring a second state quantity indicating a speed of the motion of the input unit; a third state quantity acquisition step of acquiring a third state quantity indicating an acceleration of the vehicle body; a drive permission determination step of determining whether to permit driving of the electric motor based on the first state quantity, the second state quantity, and the third state quantity, The drive permission determination step includes: the first state quantity is equal to or greater than a first threshold value; The second state quantity is equal to or greater than a second threshold value, and permitting the electric motor to generate power when the third state quantity is less than a third threshold value; or the first state quantity is equal to or greater than a first threshold value; The second state quantity is less than a second threshold value, and a control method for a vehicle, the control method including permitting the electric motor to generate power when the third state quantity is equal to or greater than a third threshold value;

12. An input unit that receives input from the legs of an occupant; a wheel to which the power input to the input section is transmitted; an electric motor that transmits output power to the wheel or a wheel other than the wheel, a first state quantity acquisition step of acquiring a first state quantity indicating the magnitude of the input; a second state quantity acquisition step of acquiring a second state quantity indicating a speed of the motion of the input unit; a third state quantity acquisition step of acquiring a third state quantity indicating an acceleration of the vehicle body; a drive permission determination step of determining whether to permit driving of the electric motor based on the first state quantity, the second state quantity, and the third state quantity, the third state quantity acquisition step includes a correction process of correcting a signal detected by an acceleration detector fixed to the vehicle body, The correction process includes: a first filtering process for attenuating frequencies of the signal above a fifth threshold; A vehicle control method, wherein the fifth threshold value is a frequency when the time constant is 1.0 seconds.

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