JP7658749B2 - Control device for electrically assisted vehicle and electrically assisted vehicle - Google Patents

Description

The present invention relates to a technology for controlling the inclination of the vehicle body in an electrically assisted vehicle with three or more wheels.

For example, Patent Document 1 discloses a saddle-type vehicle that has at least a pair of wheels, can turn by tilting the body, and can automatically limit or release the tilt of the body. Specifically, the saddle-type vehicle is equipped with a support mechanism that supports the pair of wheels so that they can move up and down relative to the body, a tilt limiting mechanism that is connected to the support mechanism and limits the up and down movement of the pair of wheels, a throttle opening sensor, a vehicle speed sensor, a brake sensor, and a control unit that controls the tilt limiting mechanism based on the detection results of these sensors. In this way, the control unit automatically controls the tilt limiting mechanism based on the detection results of the above sensors, so that the rider does not need to perform any special operation regarding the operation of the tilt limiting mechanism, and tilt limiting or release can be performed accurately.

Tilting the vehicle body means tilting it from a state in which the vehicle body is approximately vertical to the ground to the left or right when viewed from the direction of travel. Restricting the vehicle body's tilt means restricting at least a part of the vehicle body to a state in which it is approximately vertical to the ground even if the driver tries to tilt it, and lifting the tilt restriction means lifting such a restriction.

However, this patent document does not cover electrically assisted vehicles with three or more wheels, and in electrically assisted vehicles that use electric drive in response to human power, it is unclear under what conditions it would be appropriate to automatically restrict or release the tilt of the vehicle body, which is the part on which people and luggage are carried.

JP 2009-286266 A

Therefore, according to one aspect, the object of the present invention is to provide a technology for automatically limiting and releasing the tilt of a vehicle body in an electrically assisted vehicle with three or more wheels.

The control device according to the present invention has (A) a detection unit that detects the rotation state of a pedal provided on an electrically assisted vehicle having three or more wheels, including front and rear wheels, and (B) a control unit that issues an instruction to a mechanism that limits the tilt of the body of the electrically assisted vehicle or releases the tilt restriction to switch between limiting the tilt of the body and releasing the tilt restriction based on the rotation state of the pedal detected by the detection unit.

According to one aspect, in an electrically assisted vehicle with three or more wheels, the tilt limit of the vehicle body can be automatically controlled and released based on the rotation state of the pedals.

FIG. 1 is a diagram showing the external appearance of an electrically assisted bicycle according to an embodiment. FIG. 2 is a diagram showing the appearance of another power-assisted bicycle according to an embodiment of the present invention. FIG. 3 is a diagram for explaining an example of a lean limiting mechanism of an electric power assisted bicycle having two front wheels. FIG. 4A is a diagram for explaining an example of a tilt limiting mechanism. FIG. 4B is a diagram for explaining an example of the tilt limiting mechanism. FIG. 4C is a diagram for explaining an example of a tilt limiting mechanism. 5A to 5C are diagrams for explaining tilt restriction by an example of a tilt restriction mechanism and the effect of releasing the tilt restriction. FIG. 6 is a diagram for explaining another example of a lean limiting mechanism for an electrically assisted bicycle having two front wheels. FIG. 7A is a diagram for explaining another example of the tilt limiting mechanism. FIG. 7B is a diagram for explaining another example of the tilt limiting mechanism. FIG. 7C is a diagram for explaining another example of the tilt limiting mechanism. FIG. 8 is a diagram for explaining a tilt limiting mechanism of an electrically assisted bicycle having two rear wheels. 9(a) and (b) are diagrams for explaining the effect of limiting the leaning by the leaning limiting mechanism of an electrically assisted bicycle having two rear wheels and of releasing the limiting mechanism. FIG. 10 is a diagram illustrating an example of the configuration of the control device. FIG. 11 is a diagram illustrating an example of a functional block configuration of a control unit realized by the calculation unit. FIG. 12 is a diagram illustrating a process flow according to the first embodiment. FIG. 13 is a diagram illustrating a process flow according to the second embodiment. FIG. 14 is a diagram illustrating a process flow of an example of the pedal reverse rotation detection process. FIG. 15 is a diagram illustrating a processing flow of another example of the pedal reverse rotation detection processing. FIG. 16 is a diagram illustrating a process flow according to the third embodiment. FIG. 17 is a diagram for explaining the relationship between the traveling direction and the pedal rotation direction. 18A and 18B are diagrams showing an example of changes in pedal rotation phase angle and input torque over time. FIG. 19 is a diagram illustrating a process flow according to the fourth embodiment. FIG. 20 is a diagram illustrating a process flow according to the fifth embodiment. FIG. 21 is a diagram showing an example of an operation panel. FIG. 22 is a diagram illustrating a process flow according to the sixth embodiment.

The following describes an embodiment of the present invention using an example of an electrically assisted bicycle, which is one example of an electrically assisted vehicle. However, the application of the embodiment of the present invention is not limited to electrically assisted bicycles, but can also be applied to a control device for a moving body (such as a cart) that moves according to human power.

[First embodiment]
The embodiments of the present invention are directed to an electrically assisted bicycle having two or more front wheels and one or more rear wheels, or an electrically assisted bicycle having one or more front wheels and two or more rear wheels. For example, the electrically assisted bicycle may be an electrically assisted bicycle 1a having two front wheels and one rear wheel as shown in Fig. 1, or an electrically assisted bicycle 1b having one front wheel and two rear wheels as shown in Fig. 2.

The electrically assisted bicycle 1a shown in FIG. 1 has a tilt limiting mechanism, a control device 102, a battery pack 101, a torque sensor 103, a pedal rotation sensor 104, a motor 105, an operation panel 106, and a brake sensor 107. The tilt limiting mechanism will be explained in a separate drawing. Note that the electrically assisted bicycle 1b shown in FIG. 2 has a different number of motors 105, but otherwise has a similar configuration.

The battery pack 101 includes, for example, a lithium ion secondary battery, a lithium ion polymer secondary battery, a nickel metal hydride battery, etc., and supplies power to the motor 105 via the control device 102, and during regeneration, it is also charged by the regenerative power from the motor 105 via the control device 102.

The torque sensor 103 is provided on a wheel attached around the crankshaft, detects the pedal force applied by the driver, and outputs the detection result to the control device 102. Similarly to the torque sensor 103, the pedal rotation sensor 104 is provided on a wheel attached around the crankshaft, and outputs, for example, a pulse signal corresponding to the rotation to the control device 102.

The motor 105 is, for example, a well-known three-phase brushless motor, and is attached to, for example, the two front wheels of the electrically assisted bicycle 1a. The motor 105 rotates the front wheels, and the rotor is connected to the front wheels directly or via a reducer or the like so that the rotor rotates in response to the rotation of the front wheels. Furthermore, the motor 105 is equipped with a rotation sensor such as a Hall element, and outputs rotor rotation information (for example, a Hall signal) to the control device 102.

The control device 102 performs calculations based on signals from the rotation sensor of the motor 105, the torque sensor 103, the pedal rotation sensor 104, etc., to control the drive of the motor 105 and also controls regeneration by the motor 105. In this embodiment, the control device 102 also controls the tilt limiting mechanism.

The operation panel 106 receives, for example, instruction inputs from the driver regarding the presence or absence of assistance (for example, turning the power switch on and off), and, if assistance is provided, inputs such as the desired assist ratio, and outputs the instruction inputs to the control device 102. The operation panel 106 may also have a function to display data such as the travel distance, travel time, calories burned, and amount of regenerated power calculated by the control device 102. The operation panel 106 may also have a display unit such as an LED (Light Emitting Diode). This allows the driver to be informed of, for example, the charge level of the battery pack 101, its on/off state, and the mode corresponding to the desired assist ratio. In the embodiment described later, the operation panel also has a reverse switch for instructing the motor 105 to perform reverse drive.

The brake sensor 107 detects the driver's braking operation and outputs a signal related to the braking operation to the control device 102.

Next, the tilt limiting mechanism will be described with reference to Figures 3 to 9. In the case of the electric-assisted bicycle 1a shown in Figure 1, for example, as shown in Figure 3, a configuration is adopted in which the tilt limiting mechanism 108 is provided near the front wheel and connected to the control device 102 by an electric wire 1081. In the example of Figure 3, the part surrounded by the dotted line A can be tilted while riding. When the part related to the tilt limiting mechanism 108 of this electric-assisted bicycle 1a is viewed from the front, as shown in Figure 4A, it is a combination of a roughly T-shaped handle part 1601 including a handle gripped by the rider and a roughly inverted U-shaped tilt support part 1603 that clamps the front wheels 1605a and 1605b. Here, as shown in Figure 4B, the handle part 1601 has a solenoid 1613 connected to the electric wire 1081 and a plunger (movable iron core) 1615. As shown in FIG. 4C, the inclined support portion 1603 is provided with a disk 1611 having a small hole 1611a, which is a plate-like object having a shape similar to a semicircle having a diameter of 1 to 2 cm with a semicircle having a diameter smaller than a predetermined diameter removed.

The tilt limiting mechanism 108 includes, for example, a solenoid 1613, a plunger 1615, and a disk 1611. For example, when the tilt limit is released, the control device 102 energizes the solenoid 1613 via the electric wire 1081. This causes the plunger 1615 to be attracted and disengage from the small hole 1611a of the disk 1611, releasing the tilt limit on the vehicle body. On the other hand, when the control device 102 stops energizing the solenoid 1613, the plunger 1615 is pushed outward from the solenoid 1613 and returns to its original position, and fits into the small hole 1611a of the disk 1611, thereby restricting the tilt of the vehicle body. Note that the maximum angle at which tilt is permitted is determined for the tilt support portion 1603, and the driver can freely tilt the vehicle to any angle up to the maximum angle as long as the tilt limit is released.

5(a) to (c) are schematic diagrams of the electric-assisted bicycle 1a as seen from the front, and if the body tilt limit is set as shown in Fig. 5(a), the handlebars 1601, tilt support 1603, front wheels 1605a and 1605b, and rear wheel 1605c cannot be tilted and stand approximately vertically on the ground. In this way, the body tilt limit limits the handlebars 1601, tilt support 1603, front wheels 1605a and 1605b, and rear wheel 1605c, etc., included in the range indicated by dotted line A in Fig. 3, to stand approximately vertically on the ground, even if the rider tries to tilt them. On the other hand, as shown in Figures 5(b) and 5(c), if the tilt restriction is released, the driver holding the handle of the handle portion 1601 can intentionally tilt the handle to the right with the front wheels facing forward as shown in Figure 5(b), or to the left with the front wheels facing forward as shown in Figure 5(c), within the allowable range.

In addition to the tilt limiting mechanism shown in Figures 3 to 4C, a tilt limiting mechanism 109 such as that shown in Figures 6 to 7C may be used. In the case of the electric-assisted bicycle 1a shown in Figure 1, for example, as shown in Figure 6, the tilt limiting mechanism 109 has a main component 1091 provided near the front wheel, a wire 1092 connected to the main component 1091, and a motor 1093 that pulls the wire 1092. In the example of Figure 6, the part surrounded by the dotted line B can be tilted while riding. When the part related to the tilt limiting mechanism 109 of this electric-assisted bicycle 1a is viewed from the front, as shown in Figure 7A, it is a combination of a roughly T-shaped handlebar part 1701 including a handle gripped by the rider and a roughly inverted U-shaped tilt support part 1703 that holds the front wheels 1705a and 1705b in between. Here, as shown in Figure 7B, the handlebar part 1701 is provided with a disc brake 1702 having a pad. As shown in FIG. 7C, the inclined support portion 1703 is provided with a disk 1711, which is a plate-like object having a shape, for example, of a semicircle having a predetermined diameter with a semicircle having a diameter smaller than the predetermined diameter removed. The main component 1091 includes the disk brake 1702 and the disk 1711.

For example, when tilt restriction is performed, the control device 102 causes the motor 1093 to pull the wire 1902. This causes the pads of the disc brake 1702 to pinch the disc 1711, locking the vehicle body, and restricting the vehicle body from tilting. On the other hand, when the tilt restriction is released, the control device 102 causes the motor 1093 to stop pulling the wire 1902. This releases the disc brake 1702 from the locked state of the disc 1711, and the vehicle body tilt restriction is released. Note that the tilt support portion 1703 has a maximum allowable tilt angle set, and if the tilt restriction is released, the rider can freely tilt the vehicle body up to any angle up to the maximum angle. Note that, as explained with reference to FIG. 5, if the vehicle body tilt restriction is set, the rider cannot tilt the entire power-assisted bicycle 1a to the left or right, but if the tilt restriction is released, the rider can freely tilt the entire power-assisted bicycle 1a to the left or right.

In the case of an electrically assisted bicycle 1b having two rear wheels as shown in FIG. 2, as shown in FIG. 8, a tilt limiting mechanism 110 is provided in the area near the rear wheel within the dotted line C so that the area surrounded by the dotted line C including the front wheel, handlebars, saddle, saddle support, battery 101, and control device 102 can be tilted. The tilt limiting mechanism 110 may be configured as described with reference to FIG. 3 to FIG. 7C. FIGS. 9(a) and (b) are schematic views from the rear, and if the body is tilt-limited as shown in FIG. 9(a), the handlebars 1801, saddle 1802, saddle support 1803, and front wheel 1805a cannot be tilted to the left or right. On the other hand, as shown in FIG. 9(b), if the body is not tilt-limited, the handlebars 1801, saddle 1802, saddle support 1803, and front wheel 1805a can be tilted to the right or left at the rider's discretion. Regardless of whether or not there is a tilt limit, rear wheels 1805b and 1805c cannot be tilted left or right.

So far, examples of the configuration of the tilt limiting mechanism have been described, but the present invention is not limited to these configurations, and any configuration may be used as long as it is possible to limit or release the tilt of the vehicle body in response to instructions from the control device 102. For example, in the example shown in FIG. 4A, the two front wheels are supported by the tilt support part 1603, but when the tilt limit is released, the length of the support part that tilts the vehicle body out of the parts that support the left and right front wheels can be shortened, allowing the vehicle body to tilt.

By limiting the inclination of the body, it becomes easier to maintain balance, for example, when traveling at low speeds. On the other hand, for example, when turning or trying to turn left or right during normal driving, the effects of centrifugal force and the like occur, and if you try to turn forcefully, one of the two wheels may lift off the ground and lose balance. Also, if you try to drive while maintaining balance, the turning radius while driving becomes large. Therefore, for example, by releasing the inclination limit during normal driving, you can drive with the same feeling as a normal two-wheeled bicycle without a tilt limiting mechanism, that is, with the feeling of turning by tilting the body. Specifically, the body can be tilted even when turning to maintain balance, allowing for stable driving. Another advantage is that the turning radius does not need to be too large. However, from the perspective of maintaining balance and driving more stably, it is not necessarily sufficient to focus only on the vehicle speed.

Next, the configuration related to the control device 102 is shown in FIG. 10. The control device 102 has a controller 1020 and a FET (Field Effect Transistor) bridge 1030. The FET bridge 1030 includes a high-side FET (Suh) and a low-side FET (Sul) that perform switching for the U-phase of the motor 105, a high-side FET (Svh) and a low-side FET (Svl) that perform switching for the V-phase of the motor 105, and a high-side FET (Swh) and a low-side FET (Swl) that perform switching for the W-phase of the motor 105. This FET bridge 1030 constitutes part of a complementary switching amplifier.

The controller 1020 also has a calculation unit 1021, a pedal rotation input unit 1022, a motor rotation input unit 1024, a variable delay circuit 1025, a motor drive timing generation unit 1026, a torque input unit 1027, a brake input unit 1028, an AD (Analog-Digital) input unit 1029, and an instruction unit 1023 for the tilt limiting mechanism.

The calculation unit 1021 performs calculations using inputs from the operation panel 106 (e.g., assist on/off, etc.; in other embodiments, reverse switch on/off is also included), pedal rotation input unit 1022, motor rotation input unit 1024, torque input unit 1027, brake input unit 1028, and AD input unit 1029, and outputs the results to the motor drive timing generation unit 1026 and the variable delay circuit 1025. The calculation unit 1021 has a memory 10211, which stores various data used in the calculations and data in the middle of processing. Furthermore, the calculation unit 1021 may be realized by a processor executing a program, in which case the program may be recorded in the memory 10211. The memory 10211 may also be provided separately from the calculation unit 1021.

The pedal rotation input unit 1022 digitizes the pedal rotation phase angle (also called the crank rotation phase angle, including a signal indicating the direction of rotation) obtained from a signal from the pedal rotation sensor 104, for example, and outputs it to the calculation unit 1021. The motor rotation input unit 1024 digitizes a signal (e.g., rotation phase angle, direction of rotation, etc.) related to the rotation of the motor 105 (the rotation of the front wheel in this embodiment) from the hall signal output by the motor 105, and outputs it to the calculation unit 1021. The torque input unit 1027 digitizes a signal corresponding to the pedal force from the torque sensor 103 and outputs it to the calculation unit 1021. The brake input unit 1028 digitizes a signal indicating whether the brake is applied or not from the brake sensor 107, and outputs it to the calculation unit 1021. The AD input unit 1029 digitizes the output voltage from the secondary battery and outputs it to the calculation unit 1021.

The calculation unit 1021 outputs a lead angle value to the variable delay circuit 1025 as a calculation result. The variable delay circuit 1025 adjusts the phase of the Hall signal based on the lead angle value received from the calculation unit 1021 and outputs it to the motor drive timing generation unit 1026. The calculation unit 1021 outputs a PWM code corresponding to a duty ratio of PWM (Pulse Width Modulation) to the motor drive timing generation unit 1026 as a calculation result. The motor drive timing generation unit 1026 generates and outputs a switching signal for each FET included in the FET bridge 1030 based on the adjusted Hall signal from the variable delay circuit 1025 and the PWM code from the calculation unit 1021. Depending on the calculation result of the calculation unit 1021, the motor 105 may be driven by power running or may be controlled by regeneration. The basic operation of motor drive is described in the pamphlet of International Publication No. 2012/086459 and the like, and is not a main part of this embodiment, so a description thereof will be omitted here.

In this embodiment, the calculation unit 1021 further determines whether to cause the tilt limiting mechanism 108, etc. to perform tilt limiting or release the tilt limiting, and issues an instruction to the instruction unit 1023. In response to the instruction from the calculation unit 1021, the instruction unit 1023 executes either an operation for causing the tilt limiting mechanism 108, etc. to perform tilt limiting (e.g., causing the motor 1093 to wind up the wire 1902 or stopping the current supply to the solenoid 1613) or an operation for releasing the tilt limiting (e.g., causing the motor 1093 to stop winding up the wire 1902 or starting the current supply to the solenoid 1613).

Next, FIG. 11 shows an example of a functional block configuration (part relating to this embodiment) related to the control unit 3000 realized in the calculation unit 1021. The control unit 3000 according to this embodiment has a detection unit 3100 and an operation control unit 3200.

The detection unit 3100 performs processing to detect the occurrence of a predetermined state using at least one of the pedal rotation data from the pedal rotation input unit 1022 and the motor rotation data from the motor rotation input unit 1024. More specifically, it identifies the pedal rotation direction, estimates the vehicle speed from the motor rotation, and identifies the pedal rotation speed and pedal rotation angle. Note that in a later embodiment, the occurrence of a predetermined state may be detected based on input torque data from the torque input unit 1027. The operation control unit 3200 issues an instruction to the instruction unit 1023 to perform tilt restriction or to release the tilt restriction based on the state detected by the detection unit 3100. Note that in a later embodiment, the operation control unit 3200 may issue an instruction to perform tilt restriction or to release the tilt restriction based on an on or off signal of a reverse switch provided on the operation panel 106.

Next, the operation of the control unit 3000 will be described with reference to FIG. 12. Note that, to ensure safety, it is assumed that tilt limiting is instructed before processing begins. Also, steps S1 to S5 are performed for each control cycle.

First, the detection unit 3100 calculates the vehicle speed from, for example, motor rotation data, and determines whether the vehicle speed is equal to or less than a threshold value TH1 (e.g., 4 km/h) (step S1). If the vehicle speed is equal to or less than the threshold value TH1, the detection unit 3100 outputs to the operation control unit 3200 a signal indicating that the vehicle speed is equal to or less than the threshold value TH1, and the operation control unit 3200 instructs the instruction unit 1023 to implement tilt restriction in response to this output (step S3). The control unit 3000 determines whether the processing has ended due to a reason such as a power-off instruction (step S5), and if the processing has not ended, the processing returns to step S1. On the other hand, if the processing has ended due to a reason such as a power-off instruction, the processing ends.

On the other hand, if the vehicle speed exceeds the threshold value TH1, the detection unit 3100 further determines whether the vehicle speed is equal to or greater than a threshold value TH2 (e.g., 5 km/h) (step S7). If the vehicle speed is equal to or greater than the threshold value TH2, the detection unit 3100 outputs to the operation control unit 3200 a signal indicating that the vehicle speed is equal to or greater than the threshold value TH2, and the operation control unit 3200 instructs the instruction unit 1023 to release the tilt restriction in response to this output (step S9). The process then proceeds to step S5.

On the other hand, if the vehicle speed is less than the threshold value TH2, i.e., if the relationship of threshold value TH1 < vehicle speed < threshold value TH2 holds, the current control is maintained (step S11). That is, if tilt restriction is being implemented, it is left implemented, and if tilt restriction is being released, it is left released. Note that this step is represented by a dotted block, since the operation control unit 3200 does nothing.

In this embodiment, there is a relationship of threshold value TH1 < threshold value TH2, and by using these two threshold values, it is possible to prevent the vehicle speed from fluctuating around one threshold value and the operation from frequently switching between tilt limiting and releasing the tilt limiting. This makes it possible to suppress the occurrence of phenomena such as the vehicle body rattling (chattering).

In addition, if the vehicle is traveling at a speed equal to or greater than the threshold TH2, it is assumed that the vehicle is traveling stably, and therefore safety can be ensured even if the vehicle body is tilted according to the driver's wishes, and the tilt restriction is released. On the other hand, if the vehicle is traveling at a speed less than the threshold TH1, the vehicle is prone to becoming unstable at low speeds, so the vehicle body's tilt restriction is applied to ensure safety.

In this way, in this embodiment, the tilt limiting mechanism 108 and the like are switched between releasing the tilt limit and implementing the tilt limit based on the vehicle speed.

[Embodiment 2]
When the body of the electrically assisted bicycle 1 (electrically assisted bicycle 1a or 1b) is tilted in a situation where the pedals are rotated in the reverse direction, which is not usually done, the bicycle is likely to lose balance and become unstable. This embodiment focuses on this point.

The operation of the control unit 3000 according to this embodiment will be described with reference to Figs. 13 to 15. Note that, to ensure safety, it is assumed that tilt limiting is instructed before processing begins. Also, steps S21 to S27 are performed for each control cycle.

First, the detection unit 3100 executes a process for detecting reverse rotation of the pedals (pedal reverse rotation detection process) (FIG. 13: step S21). An example of this process will be described with reference to FIG. 14. Note that the initial detection state before the start of the process flow in FIG. 14 is assumed to be reverse rotation. This is because if the initial detection state is forward rotation, the tilt restriction would be immediately released, causing the vehicle body to wobble when starting.

The detection unit 3100 determines whether the pedal rotation speed calculated from the pedal rotation information is equal to or less than a negative threshold value TH11 (e.g., -5 km/h in terms of vehicle speed, but it may simply be a threshold value for the rotation speed [rpm]) (step S31). In this embodiment, a positive pedal rotation speed is obtained when the pedal is rotated in the positive direction (when the pedal is rotated in the direction that moves the electrically assisted bicycle 1 forward), and a negative pedal rotation speed is obtained when the pedal is rotated in the negative direction.

If the pedal rotation speed is equal to or less than the negative threshold value TH11, the detection unit 3100 determines that the pedal is rotating in reverse (step S33). Then, the process returns to the original process. On the other hand, if the pedal rotation speed exceeds the negative threshold value TH11, the detection unit 3100 determines whether the pedal rotation speed is equal to or greater than a positive threshold value TH12 (e.g., 1 km/h in vehicle speed terms) that is greater than the threshold value TH11 (step S35). If this condition is met, the detection unit 3100 determines that the pedal is not rotating in reverse (step S37). Then, the process returns to the original process.

On the other hand, if the pedal rotation speed is less than the threshold value TH12, i.e., if the relationship of threshold value TH11 < pedal rotation speed < threshold value TH12 holds, the detection unit 3100 maintains the pre-detection state (step S39). That is, if it has determined that the pedal is rotating in reverse, it maintains the determination that the pedal is rotating in reverse, and if not, it maintains the determination that the pedal is not rotating in reverse. Then, the process returns to the process that called the process.

This can prevent the result from switching frequently when the pedal rotation speed fluctuates around 0.

Returning to the explanation of the process in FIG. 13, the detection unit 3100 determines whether or not the pedal is rotating in reverse as a result of the detection in step S21 (step S23). If the pedal is rotating in reverse, the detection unit 3100 outputs to the operation control unit 3200 that the pedal is rotating in reverse. In response to this output, the operation control unit 3200 instructs the instruction unit 1023 to implement tilt limitation (step S25). The control unit 3000 then determines whether or not the process has ended due to a reason such as an instruction to turn off the power (step S27), and if the process has not ended, the process returns to step S21. On the other hand, if the process has ended due to a reason such as an instruction to turn off the power, the process ends.

On the other hand, if it is determined in step S21 that the pedal is not rotating in reverse, the detection unit 3100 outputs to the operation control unit 3200 that the pedal is not rotating in reverse. In response to this output, the operation control unit 3200 instructs the instruction unit 1023 to release the tilt restriction (step S29). The process then proceeds to step S27.

By performing the above process, when reverse pedal rotation is detected, tilt restriction is implemented to prevent the vehicle from becoming unstable.

Note that the process in FIG. 15 may be performed instead of FIG. 14. Note that the initial detection state is reverse rotation.

The detection unit 3100 calculates the pedal rotation angle from the difference between the pedal rotation phase angle (also called the pedal rotation position) at the time of the previous processing and the pedal rotation phase angle at the time of the current processing, and determines whether the pedal rotation angle is equal to or less than a negative threshold value TH31 (e.g., -180°) (step S41). In this embodiment, when the pedal is rotated in the positive direction (when the pedal is rotated in the direction that moves the electric assisted bicycle 1 forward), a positive pedal rotation angle is obtained, and when the pedal is rotated in the reverse direction, a negative pedal rotation angle is obtained.

If the pedal rotation angle is equal to or less than the negative threshold TH31, the detection unit 3100 determines that the pedal is rotating in reverse (step S43). Then, the process returns to the original process. On the other hand, if the pedal rotation angle exceeds the negative threshold TH31, the detection unit 3100 determines whether the pedal rotation angle is equal to or greater than a positive threshold TH32 (e.g., +90°) that is greater than the threshold TH31 (step S45). If this condition is met, the detection unit 3100 determines that the pedal is not rotating in reverse (step S47). Then, the process returns to the original process.

On the other hand, if the pedal rotation angle is less than the threshold value TH32, i.e., if the relationship of threshold value TH31 < pedal rotation angle < threshold value TH32 holds, the detection unit 3100 maintains the pre-detection state (step S49). In other words, if reverse rotation is detected, reverse rotation is maintained, and if not, it is determined that reverse rotation is not being detected. Then, the process returns to the process that called the process.

In this way, it is possible to determine whether the pedal is rotating in reverse based on the pedal rotation angle.

[Embodiment 3]
In order to perform more precise control, lean limiting may be switched between being enabled and disabled based on the vehicle speed and pedal rotation.

The operation of the control unit 3000 according to this embodiment will be described with reference to FIG. 16. Note that, to ensure safety, it is assumed that tilt limiting is instructed before processing begins. Also, steps S21 to S27 are performed for each control cycle.

First, the detection unit 3100 executes a process for detecting reverse rotation of the pedal (pedal reverse rotation detection process) ( FIG. 16 : step S51). This process is, for example, the process shown in FIG. 14 or FIG. 15.

Then, the detection unit 3100 judges whether or not the pedal is rotating in reverse as a result of the detection in step S51 (step S53). If the pedal is rotating in reverse, the detection unit 3100 outputs to the operation control unit 3200 that the pedal is rotating in reverse. Furthermore, the detection unit 3100 judges whether or not the vehicle speed is equal to or lower than a threshold value TH41 (e.g., 6 km/h) (step S55). If the vehicle speed is equal to or lower than the threshold value TH41, the detection unit 3100 outputs to the operation control unit 3200 that the vehicle speed is equal to or lower than the threshold value TH41. In response to this output, the operation control unit 3200 instructs the instruction unit 1023 to implement tilt limitation (step S57).

In this way, when the pedals are rotating in reverse, unless the vehicle speed exceeds the threshold value TH41 even during normal driving, the vehicle is likely to become unstable, so tilt restriction is implemented.

The control unit 3000 then determines whether the processing has ended due to a reason such as an instruction to turn off the power (step S61), and if the processing has not ended, the processing returns to step S51. On the other hand, if the processing has ended due to a reason such as an instruction to turn off the power, the processing ends.

On the other hand, if the vehicle speed exceeds the threshold value TH41, the detection unit 3100 outputs to the operation control unit 3200 that the vehicle speed exceeds the threshold value TH41, but the operation control unit 3200 maintains the current control of the tilt limit (step S59). Since the operation control unit 3200 does nothing in this step, step S59 is represented by a dotted block. If the vehicle is traveling at a speed that exceeds the threshold value TH41, there is a high possibility that stable traveling will be possible even if the pedals are rotated in reverse, so if the tilt limit has been released, it is left released, and if the tilt limit is applied, it is left applied. Then the process proceeds to step S61.

On the other hand, if the pedals are not rotating in reverse, the detection unit 3100 determines whether the vehicle speed is equal to or less than the threshold value TH42 (e.g., 3 km/h) (step S63). If the vehicle speed is equal to or less than the threshold value TH42, the detection unit 3100 outputs to the operation control unit 3200 that the vehicle speed is equal to or less than the threshold value TH42. In response to this output, the operation control unit 3200 instructs the instruction unit 1023 to implement tilt restriction (step S65). The process then proceeds to step S61. In this way, tilt restriction is implemented because driving is likely to become unstable when driving at a low speed below the threshold value TH42.

On the other hand, if the vehicle speed exceeds the threshold value TH42, the detection unit 3100 determines whether the vehicle speed is equal to or greater than a threshold value TH43 (e.g., 5 km/h) (step S67). If the vehicle speed is equal to or greater than the threshold value TH43, it can be determined that the pedals are rotating forward and the vehicle is traveling normally. Therefore, the detection unit 3100 outputs to the operation control unit 3200 that the vehicle speed is equal to or greater than the threshold value TH43, and in response to this output, the operation control unit 3200 instructs the instruction unit 1023 to release the tilt restriction (step S69). The process then proceeds to step S61.

On the other hand, if the vehicle speed is less than the threshold value TH43, the operation control unit 3200 does nothing, and leaves the tilt restriction released if it has been released, or leaves the tilt restriction applied if it has been applied (step S59). Then, the process proceeds to step S61.

By performing this processing, if a vehicle speed exceeding the threshold value TH41 can be detected even during normal driving, the lean restriction can be released to facilitate turning even if the pedals are rotating in reverse. This is because there is a high possibility of stable driving.

[Fourth embodiment]
In this embodiment, the tilt restriction is switched between being enabled and being released while taking into consideration the driver's intention. This is because, even if the vehicle is not clearly in normal driving mode, if the vehicle is going to be in normal driving mode if the driver continues to rotate the pedal in the forward direction, it may be appropriate to release the tilt restriction early.

The operation of the operation control unit 3200 according to this embodiment will be described with reference to Figures 17 to 19.

First, the state to be detected will be described with reference to Figs. 17 to 19. Fig. 17 shows a schematic diagram of the relationship between the traveling direction of the electrically assisted bicycle 1 and the rotational phase angle of the pedal. In other words, when the traveling direction of the electrically assisted bicycle 1 is to the right on the paper, for example, when the crank in front faces directly upward on the paper, the rotational phase angle of the pedal is 0°, and when the pedal is rotated clockwise as shown by the curved arrow, the rotational phase angle of the pedal increases. When the crank in front faces to the right, the rotational phase angle of the pedal is 90°, and when the crank in front faces directly downward, the rotational phase angle of the pedal is 180°. When the pedal is further rotated, when the crank in front faces to the left, the rotational phase angle of the pedal is 270°, and when the crank in front faces directly upward again, the rotational phase angle of the pedal is 360° = 0°.

Under these assumptions, FIG. 18(a) shows the change over time in the pedal rotation phase angle represented by the pedal rotation input signal from the pedal rotation sensor 104, and FIG. 18(b) shows the change over time in the input torque value from the torque input unit 1027.

In general, when the pedal is rotated, the input torque changes as shown by curve a in FIG. 18(b). In this example, while the pedal rotation phase angle changes, for example, from 45° to 180°, the input torque increases once and then decreases, reaching a minimum at 180° with the right foot in FIG. 17 (t=t1). After that, as the pedal is rotated further and the pedal rotation phase angle changes from 180° to 360°, the input torque also increases once and then decreases, reaching a minimum at 360°=0° with the left foot in FIG. 17 (t=t2). From then on, the input torque similarly reaches a minimum when the pedal is rotated 180°. The point where the input torque becomes a minimum is called the bottom dead center. The bottom dead center occurs when the pedal rotation phase angle is 0° and 180°.

If the lean limit is released near the bottom dead center, it is possible that if the pedal rotation is stopped at that point, the vehicle body may lean and lose stability. Therefore, if it is confirmed that the pedal rotation is continuing beyond the bottom dead center, the lean limit is released. In other words, the lean limit is released at a timing later than time t1.

In addition, after the bottom dead center has been confirmed two or more times, the tilt restriction may be released, for example, at a timing later than time t2. This allows for more continuous pedal rotation to be confirmed.

Note that passing the bottom dead center can only be confirmed later than time t1, and the bottom dead center cannot be confirmed until the input torque has increased to a certain extent.

On the other hand, if the pedal rotation phase angle is used as the standard, continuous pedal rotation may be confirmed when it is detected that the pedal rotation phase angle has exceeded 180°, which corresponds to the bottom dead center, and reached, for example, 225°, or when it has exceeded 225° and then reached 45°.

The operation of the control unit 3000 according to this embodiment will be described with reference to FIG. 19. Note that, to ensure safety, it is assumed that tilt limiting is instructed before processing begins. Also, steps S71 to S75 are performed for each control cycle.

First, the detection unit 3100 determines whether the vehicle speed is equal to or less than a threshold value TH52 (e.g., 3 km/h) (step S71). If the vehicle speed is equal to or less than the threshold value TH52, the detection unit 3100 outputs to the operation control unit 3200 that the vehicle speed is equal to or less than the threshold value TH52. Then, in response to this output, the operation control unit 3200 instructs the instruction unit 1023 to implement tilt restriction (step S73). If the vehicle is traveling at a low speed, tilt restriction is implemented.

The control unit 3000 then determines whether the processing has ended due to a reason such as an instruction to turn off the power (step S75), and if the processing has not ended, the processing returns to step S71. On the other hand, if the processing has ended due to a reason such as an instruction to turn off the power, the processing ends.

On the other hand, if the vehicle speed exceeds the threshold value TH52, the detection unit 3100 attempts to detect bottom dead center from this point on. However, the detection unit 3100 determines whether the vehicle speed is equal to or greater than the threshold value TH51 (e.g., 5 km/h) (step S77). If the vehicle speed is equal to or greater than the threshold value TH51, the tilt restriction may be released, so the detection unit 3100 outputs to the operation control unit 3200 that the vehicle speed is equal to or greater than the threshold value TH51. In response to this output, the operation control unit 3200 instructs the instruction unit 1023 to release the tilt restriction (step S79). If the tilt restriction is released, bottom dead center detection is not performed. Then, the process proceeds to step S75.

On the other hand, if the vehicle speed is less than the threshold value TH51, the detection unit 3100 determines whether the pedal has been rotated in the forward direction enough to confirm bottom dead center after the vehicle speed exceeds the threshold value TH52 (step S81). As described above, whether the input torque value has become minimal can only be confirmed after the input torque has increased to a certain extent. Therefore, for example, it is assumed that bottom dead center has been confirmed when the input torque value has increased by a certain percentage (e.g., 25%) or more from the most recent minimum value. Note that the condition may also be that bottom dead center has been confirmed multiple times.

If it is determined that such conditions are met, the detection unit 3100 outputs to the operation control unit 3200 that the above conditions are met. In response to this output, the operation control unit 3200 instructs the instruction unit 1023 to release the tilt restriction (step S83). The process then proceeds to step S75.

On the other hand, if the condition of step S81 is not met, that is, if the vehicle speed exceeds the threshold value TH52 but the bottom dead center cannot be confirmed, the detection unit 3100 outputs to the operation control unit 3200 that the above condition is not met. In response to this output, the operation control unit 3200 maintains the current control of the tilt limit (step S85). Since the operation control unit 3200 does nothing in this step, step S85 is represented by a dotted block. In other words, if the tilt limit has been released, it remains released, and if the tilt limit has been applied, it remains applied. This is to prevent chattering, as in the first embodiment. Then the process proceeds to step S75.

In this way, when the vehicle speed is less than the threshold value TH51 but exceeds the threshold value TH52, if further pedal rotation by the driver is confirmed, the condition of step S81 is met, and the tilt restriction is released. This allows the tilt restriction to be released early.

As mentioned above, the condition of step S81 may be changed to, instead of the value of the input torque, when it is confirmed that the rotational phase angle of the pedal has reached an angle (e.g., 225°) indicating that it has passed bottom dead center, or when it is detected that the rotational phase angle of the pedal has rotated a predetermined angle from the phase angle (e.g., 225°) indicating that it has passed bottom dead center, or when the rotational phase angle of the pedal has reached the phase angle (e.g., 225°) indicating that it has passed bottom dead center and the next phase angle (e.g., 45°) indicating that further rotation has occurred, etc.

[Embodiment 5]
In the fourth embodiment, the continuity of pedal rotation is determined from the input torque value and the pedal rotation phase angle, but it is also possible to determine the continuity of pedal rotation using time.

The operation of the control unit 3000 according to this embodiment will be described with reference to FIG. 20. This processing flow is almost the same as that of FIG. 19, except that step S91 is added after step S73, if it is detected in step S71 that the vehicle speed has exceeded the threshold value TH52, measurement of the duration of forward pedal rotation is started, and step S93 is introduced instead of step S81.

In step S91, since tilt restriction is to be implemented, the detection unit 3100 clears the measurement of the duration of forward pedal rotation. In other words, it sets the duration to zero.

Also, if it is determined in step S71 that the vehicle speed has exceeded the threshold value TH52, the controller 10 starts measuring the duration of the forward pedal rotation (pedal rotation duration). For example, if the pedal rotation phase angle continues to increase, the rotation duration is increased.

Then, in step S93, the detection unit 3100 determines whether the duration of pedal rotation is equal to or greater than a threshold value TH53 (e.g., 3 seconds). If the duration of pedal rotation is equal to or greater than the threshold value TH53, the process proceeds to step S83; if not, the process proceeds to step S85.

If continuous positive pedal rotation is detected in this way, the tilt restriction is released early even if the vehicle speed is not above threshold value TH51.

Sixth Embodiment
For example, the operation panel 106 may be provided with a reverse switch for instructing the motor 105 to drive backward. When this switch is turned on, the control device 102 drives the vehicle backward when the vehicle speed drops below a certain speed near zero. However, if the tilt limit is released during reverse driving, the vehicle may become unstable.

Therefore, in this embodiment, when the reverse switch is turned on, the lean limit is implemented regardless of the vehicle speed.

As shown in FIG. 21, the operation panel 106 is provided with an LED 1063 indicating whether the power is on or off, two 7-segment LEDs 1064, a switch 1061 for turning the headlights on or off, a switch 1062 for turning the power on and off and setting the mode, and a reverse switch (B) 1065.

Then, the operation control unit 3200 executes the process shown in FIG. 22. Note that steps S101 to S107 are executed for each control cycle.

That is, the operation control unit 3200 determines whether the reverse switch 1065 is turned on (step S101). If the reverse switch is turned on, that is, if reverse drive is instructed, the operation control unit 3200 instructs the instruction unit 1023 to limit the tilt (step S103).

Then, the control unit 3000 determines whether the processing has ended due to a reason such as an instruction to turn off the power (step S107), and if the processing has not ended, the processing returns to step S101. On the other hand, if the processing has ended due to a reason such as an instruction to turn off the power, the processing ends.

On the other hand, if the reverse switch 1065 is off, the operation control unit 3200 instructs the instruction unit 1023 to release the tilt restriction (step S105). Then, the process proceeds to step S107.

For example, if the processes of the first to fifth embodiments are being executed simultaneously, the tilt restriction may not be released in step S105, but the control in those processes may be followed. This will enable the system to handle states other than the reverse switch being on or off.

Although the embodiments of the present invention have been described above, the present invention is not limited to these. For example, any of the technical features in each of the embodiments described above may be deleted, or any of the technical features described in other embodiments may be added, depending on the purpose.

Furthermore, the functional block diagram described above is an example, and one functional block may be divided into multiple functional blocks, or multiple functional blocks may be integrated into one functional block. As for the processing flow, the order of steps may be changed or multiple steps may be executed in parallel, as long as the processing content does not change.

The above-mentioned embodiment can be summarized as follows:

The control device according to this embodiment has (A) a detection unit (e.g., detection unit 3100) that detects the rotation state of a pedal provided on an electrically assisted vehicle having three or more wheels, including front and rear wheels, and (B) a control unit (e.g., operation control unit 3200) that instructs a mechanism that limits the tilt of the body of the electrically assisted vehicle or releases the tilt limit to switch between limiting the tilt of the body and releasing the tilt limit, based on the rotation state of the pedal detected by the detection unit.

In this way, the rotation state of the pedals on an electrically assisted vehicle affects stable driving, so the system detects the rotation state of the pedals and automatically switches between limiting the vehicle body's tilt and releasing the tilt limit to maintain stable driving.

The control unit described above may instruct the mechanism to limit the tilt of the vehicle body when the rotation state of the pedal indicates that the pedal is rotating in reverse. When the pedal is rotating in reverse, the vehicle tends to become unstable, so by performing the above-mentioned control, stable driving is maintained.

The detection unit described above may also detect that the pedal is rotating in reverse based on the rotation angle or rotation speed of the pedal in the reverse direction (e.g., FIG. 14 or FIG. 15). For example, when the pedal is rotating in reverse by a certain rotation angle or more, if a certain or greater pedal rotation speed in the reverse direction is detected, it may be determined that the pedal is rotating in reverse.

Furthermore, the detection unit described above may further detect the vehicle speed of the electrically assisted vehicle. In this case, the control unit described above may instruct the mechanism to limit the inclination of the vehicle body when the vehicle speed detected by the detection unit is equal to or lower than a certain value (e.g., TH41 = 6 km/h) and the rotation state of the pedal indicates that the pedal is rotating in reverse. This is because when the pedal is rotating in reverse, if the vehicle speed is not equal to or higher than the certain value (e.g., TH41 = 6 km/h) even during normal driving, the vehicle will lose balance and become unsteady, which will affect stable driving. Conversely, if the vehicle speed is equal to or higher than the certain value, there is a high possibility that stable driving can be maintained even if the pedal is rotating in reverse and the inclination of the vehicle body is not limited.

The above-mentioned constant value is, for example, a value greater than the vehicle speed threshold (e.g., TH42 = 5 km/h) for releasing the tilt restriction when the pedals are rotated forward. As mentioned above, this makes the conditions stricter than those for normal driving.

Furthermore, the detection unit described above may further detect the vehicle speed of the electrically assisted vehicle. In this case, the control unit described above may instruct the mechanism to release the tilt restriction when the vehicle speed detected by the detection unit exceeds a first threshold value (e.g., TH51 = 3 km/h) for limiting the tilt of the vehicle body and is less than a second threshold value (e.g., TH52 = 5 km/h) for releasing the tilt restriction, and the forward rotation of the pedals meets a predetermined condition. This is because, even if the vehicle speed condition is not met, stable driving may be maintained even if the tilt restriction of the vehicle body is released based on the forward rotation of the pedals. This allows the vehicle body to tilt early, making it easier to turn, etc.

The above-mentioned predetermined conditions are, for example, (a) that it is detected that the rotational position of the pedal has reached bottom dead center once or multiple times, (b) that the rotational phase angle of the pedal has passed one or multiple predetermined phase angles (e.g., passing 225°, or reaching 225° and then becoming 45°), and (c) that the rotational duration of the pedal is equal to or longer than a certain period of time. In this way, if it is possible to detect that the pedal is rotating in the positive direction for a certain period of time and if the above-mentioned vehicle speed conditions are met, stable driving can be maintained.

The control unit described above may also instruct the mechanism to limit the tilt of the vehicle body when it detects that a switch for instructing the electrically assisted vehicle to drive in reverse has been turned on. When the switch is turned on, it is understood that the driver intends to move the electrically assisted vehicle backwards, and therefore the tilt of the vehicle body is limited in order to maintain stable driving.

Such configurations are not limited to those described in the embodiments, and may be implemented in other configurations that achieve substantially the same effects.

3000 Control unit 3100 Detection unit 3200 Operation control unit

Claims (9)

A detection unit that detects a rotation state of a pedal provided in an electrically assisted vehicle having three or more wheels including front wheels and rear wheels;
a control unit that issues an instruction to a mechanism that limits the inclination of a body of the electrically assisted vehicle or releases the inclination limit, to switch between limiting the inclination of the body and releasing the inclination limit, based on the rotation state of the pedal detected by the detection unit; and
A control device having the above configuration. The control unit is
The control device according to claim 1 , further comprising: an instruction for instructing the mechanism to limit the lean of the vehicle body when the rotation state of the pedal indicates that the pedal is rotating in reverse. The control device according to claim 2 , wherein the detection unit detects that the pedal is rotating in the reverse direction based on a pedal rotation angle or a pedal rotation speed in the reverse direction. The detection unit further detects a vehicle speed of the electrically assisted vehicle,
The control device according to claim 1 , wherein the control unit instructs the mechanism to limit the inclination of the vehicle body when the vehicle speed detected by the detection unit is equal to or lower than a certain value and the rotation state of the pedal indicates that the pedal is rotating in reverse. The control device according to claim 4 , wherein the constant value is a value greater than the threshold vehicle speed for releasing the tilt restriction when the pedal is rotated forward. The detection unit further detects a vehicle speed of the electrically assisted vehicle,
The control unit is
2. The control device according to claim 1, wherein when the vehicle speed detected by the detection unit exceeds a first threshold for limiting the lean of the vehicle body and is less than a second threshold for releasing the lean limit, and the forward rotation of the pedal satisfies a predetermined condition, the control device instructs the mechanism to release the lean limit. The predetermined condition is
Detecting that the rotational position of the pedal has reached the bottom dead center one or more times;
The rotational phase angle of the pedal has passed through one or more predetermined phase angles, or
The rotation of the pedal continues for a certain period of time or more.
7. The control device according to claim 6, The control unit is
when it is detected that a switch for instructing the electric power assisted vehicle to drive in reverse rotation has been turned on, instructing the mechanism to limit the inclination of the vehicle body;
When it is detected that the switch is off, an instruction is given to the mechanism to switch between limiting the lean of the vehicle body and releasing the lean limit based on at least the rotation state of the pedal.
A control device according to any one of claims 1 to 7.
A control device according to any one of claims 1 to 8,
An electrically assisted vehicle with three or more wheels, including front and rear wheels.

Images