JP7379324B2 - Motor control device and electric assist vehicle - Google Patents

Description

The present invention relates to a technology for controlling a motor installed in an electrically assisted vehicle.

A power-assisted bicycle, which is an example of a power-assisted vehicle, is capable of moving forward by driving a motor in accordance with, for example, pedal input torque. However, if you try to return in the direction of entry in a passageway so narrow that you cannot make a U-turn, you would previously have to get off your electric-assist bicycle and pull it back. Furthermore, if you try to pull out only your own bicycle when multiple bicycles are packed together in a bicycle storage area, it may be difficult to pull it backwards.

International Publication No. 2012/086458 Pamphlet

Therefore, one aspect of the present invention is to provide a technique that allows a person to back up while riding in an electrically assisted vehicle.

The motor control device according to the present invention includes (A) a drive unit that drives a motor of an electrically assisted vehicle, and (B) a drive unit that drives the electrically assisted vehicle to move backward when detecting reverse rotation of a pedal that satisfies a first condition. and a control section that controls the section.

According to one aspect, it will be possible to back up while riding in an electrically assisted vehicle.

FIG. 1 is a diagram showing the appearance of an electrically assisted bicycle. FIG. 2 is a diagram for explaining the direction of pedal rotation. FIG. 3 is a diagram showing a configuration example of a motor drive control device. FIG. 4 is a diagram showing an example of the functional block configuration of the reverse control section. FIG. 5 is a diagram showing the main processing flow of reverse control. FIG. 6 is a diagram illustrating a first example of backward determination processing. FIG. 7 is a diagram showing the relationship between |tire rotation speed| and output torque. FIG. 8 is a diagram showing temporal changes in the gain multiplied by the output torque. FIG. 9 is a diagram showing a processing flow of output torque setting processing. FIG. 10 is a diagram illustrating a second example of the backward determination process. FIG. 11 is a diagram illustrating a third example of the retreat determination process. FIG. 12 is a diagram illustrating a portion of the third and fourth examples of the retreat determination process. FIG. 13 is a diagram illustrating a fourth example of the backward determination process. FIG. 14 is a diagram showing an example of adjusting the output torque upper limit value according to the pedal reverse rotation speed. FIG. 15 is a diagram showing an example in which the upper limit value of |tire rotation speed| is adjusted according to the pedal reverse rotation speed. FIG. 16 is a diagram showing the relationship between |tire rotation speed| and output torque. FIG. 17 is a diagram showing the relationship between |tire rotation speed| and pedal reverse rotation speed. FIG. 18 is a diagram illustrating an example of confirmation processing. FIG. 19 is a diagram showing another relationship between |tire rotation speed| and pedal reverse rotation speed. FIG. 20 is a diagram showing another example of the confirmation process.

[Embodiment 1]
FIG. 1 is an external view showing an example of a power-assisted bicycle, which is an example of a power-assisted vehicle in this embodiment. In this embodiment, as shown in FIG. 1, a three-wheeled electrically assisted bicycle will be described, but the application target of this embodiment is not limited to three-wheeled electrically assisted bicycles; An assisted bicycle or two-wheeled bicycle may be used as long as it can stand on its own when stopped by means of auxiliary wheels, a rear car, or other means. Note that being able to stand on your own when stopped is mainly a requirement from a safety perspective, and if safety can be ensured by some means, it may not be necessary to be able to stand on your own when stopped.

This electrically assisted bicycle 1 is equipped with a motor drive device. The motor drive device includes a battery pack 101, a motor drive control device 102, a torque sensor 103, a pedal rotation sensor 104, and a motor 105. Note that in addition to the motor 105, a tire rotation sensor may be provided. Furthermore, for safety etc., a load sensor 108 may be provided.

The electrically assisted bicycle 1 also has a front wheel, a rear wheel, a headlamp, a freewheel, a transmission, and the like.

The battery pack 101 is, for example, a lithium ion secondary battery, but may also be other types of batteries, such as a lithium ion polymer secondary battery, a nickel metal hydride storage battery, or the like. The battery pack 101 supplies power to the motor 105 via the motor drive control device 102, and also charges with the regenerated power from the motor 105 via the motor drive control device 102 during regeneration.

The torque sensor 103 is provided around the crankshaft, detects the pedal force exerted by the driver, and outputs the detection result to the motor drive control device 102 . Further, like the torque sensor 103, the pedal rotation sensor 104 is provided around the crankshaft, and outputs a signal corresponding to the rotation to the motor drive control device 102.

The motor 105 is, for example, a well-known three-phase DC brushless motor, and is mounted, for example, on the front wheel of the electrically assisted bicycle 1. The motor 105 rotates the front wheel, and the rotor is connected to the front wheel so that the rotor rotates in accordance with the rotation of the front wheel. Further, the motor 105 includes a rotation sensor such as a Hall element, and outputs rotor rotation information (ie, a Hall signal) to the motor drive control device 102.

When the user is riding the electrically assisted bicycle 1, the motor drive control device 102 performs predetermined calculations based on signals from the rotation sensor of the motor 105, the torque sensor 103, the pedal rotation sensor 104, etc. The power running drive of the motor 105 is controlled, and the regenerative braking of the motor 105 is also controlled. For example, when the user is riding the electrically assisted bicycle 1 while the bicycle is stopped, the pedals may be rotated in the opposite direction (as shown in FIG. When the electric power assisted bicycle 1 is activated, the motor 105 is powered in the reverse direction and the electric assist bicycle 1 is controlled to move backward.

The load sensor 108 is provided under the saddle, for example, and outputs a signal indicating whether the user is seated on the saddle or a signal indicating the measured weight to the motor drive control device 102.

Next, FIG. 3 shows a configuration related to the motor drive control device 102 according to this embodiment.

The motor drive control device 102 includes 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, and 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 functions as an inverter that powers the motor 105 in the forward or reverse direction or performs regenerative braking.

The controller 1020 also includes a calculation section 1021, a load input section 1022, a pedal rotation input section 1023, a tire rotation input section 1024, a variable delay circuit 1025, a motor drive timing generation section 1026, and a torque input section 1027. and an AD (Analog-Digital) input section 1029.

The calculation unit 1021 performs a predetermined calculation using the input from the pedal rotation input unit 1023, the input from the tire rotation input unit 1024, the input from the torque input unit 1027, and the input from the AD input unit 1029 to drive the motor. It outputs to the timing generation section 1026 and the variable delay circuit 1025. The calculation unit 1021 may further use input from the load input unit 1022. Note that the calculation unit 1021 has a memory 10211, and the memory 10211 stores various data used in calculations, data in the middle of processing, and the like. Furthermore, the calculation unit 1021 may be realized by a processor executing a program, and in this case, the program may be recorded in the memory 10211. Further, the memory 10211 may be provided separately from the calculation unit 1021.

The load input unit 1022 digitizes a signal from the load sensor 108 indicating whether the rider is seated or a signal indicating the measurement result of the load applied to the saddle, and outputs the digitized signal to the calculation unit 1021. The pedal rotation input unit 1023 digitizes the input from the pedal rotation sensor 104 regarding the rotation of the pedal (that is, the rotation of the crankshaft) and outputs it to the calculation unit 1021 . Note that the pedal rotation sensor 104 may be a sensor that can detect the direction of rotation, or may be a sensor that cannot detect the direction of rotation.

The tire rotation input unit 1024 receives a signal related to the rotation of the motor 105 from the Hall signal output by the motor 105, that is, a signal related to the rotation of the front wheel in this embodiment (for example, a signal representing a rotation phase angle. However, the rotation direction may also be included). is digitized and output to the arithmetic unit 1021. For example, the tire rotation input unit 1024 may calculate and output the speed of the electrically assisted bicycle 1 (for example, a positive speed is a forward speed and a negative speed is a backward speed) from the tire rotation input. Torque input section 1027 digitizes a signal corresponding to the pedal force from torque sensor 103 and outputs it to calculation section 1021 . The AD input section 1029 digitizes the output voltage from the secondary battery and outputs it to the calculation section 1021.

The calculation unit 1021 outputs the 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, for example, 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. Motor drive timing generation section 1026 generates and outputs switching signals for each FET included in FET bridge 1030 based on the adjusted Hall signal from variable delay circuit 1025 and the PWM code from calculation section 1021. Depending on the calculation result of the calculation unit 1021, the motor 105 may be driven in power running or may be regeneratively braked. Further, the direction of rotation may be in the opposite direction or in the forward direction. Note that basic operations such as driving the motor are described in the International Publication No. 2012/086459 pamphlet and the like, and are not a main part of this embodiment, so a description thereof will be omitted here.

Next, FIG. 4 shows a functional block configuration example related to the reverse control section 3000 in the calculation section 1021. The reverse control unit 3000 includes a reverse determination unit 3100 and a control unit 3200.

The reversing determination unit 3100 determines whether or not reversing is allowed based on pedal rotation input, pedal input torque, tire rotation input, etc., and transmits the determination result to the control unit 3200 using a reversing permission flag (ON/OFF). Output to. When the backward permission flag indicates permission, the control unit 3200 controls the motor drive timing generation unit 1026 and the variable delay circuit so that the motor 105 rotates in the opposite direction based on the pedal rotation input, tire rotation input, etc. The motor 105 is controlled via the FET bridge 1025 and the FET bridge 1030. Note that when the backward permission flag indicates prohibition, the control unit 3200 performs conventional control.

Note that the reverse control unit 3000 uses the pedal rotation speed ([rpm]), pedal rotation angular acceleration ([rad/s ² ]), pedal rotation angle amount ([rad] or [deg]), etc., so the reverse control The unit 3000 calculates these values from the pedal rotation input. Similarly, since the reverse control unit 3000 uses the tire rotation speed ([km/h]), the reverse control unit 3000 calculates this value from the tire rotation input. Note that in this embodiment, the tire rotation speed is substantially the same as the vehicle speed.

Next, the processing of the reverse control section 3000 will be explained using FIGS. 5 to 9.

First, for example, when the power switch is turned on and processing is started, the reversing determination unit 3100 sets the reversing permission flag to OFF as an initial process (FIG. 5: Step S1). Note that when the start of pedal rotation is detected based on the pedal rotation input, measurement of the amount of pedal rotation angle is started, and measurement of elapsed time from the start of pedal rotation may also be started. Further, in the processing flow of FIG. 5, the processing from step S3 to step S21 is repeated every unit time.

Then, the backward determination unit 3100 executes a backward determination process (step S3). Although various aspects can be adopted for this backward determination process, the aspect that is easiest to understand (reverse determination process A) will be described first with reference to FIG. 6.

FIG. 6 shows processing when the pedal rotation sensor 104 is a sensor that can detect the rotation direction (reverse rotation or forward rotation) of the pedal.

The backward determination unit 3100 determines whether the pedal is being rotated in the reverse direction based on the pedal rotation input (FIG. 6: Step S31). If the pedal is not being rotated in the reverse direction, that is, is stopped or being rotated in the forward direction, the reverse determination unit 3100 sets the reverse permission flag to OFF (step S41). The process then returns to the calling process.

On the other hand, if the pedals are being rotated in the reverse direction, the reverse determination unit 3100 determines whether the reverse pedal rotation speed ([rpm]) is equal to or higher than the threshold value TH3 (for example, 30 rpm) (step S33). ). This is to judge whether or not the reverse rotation is being performed at a high speed higher than a predetermined level.

If the pedal reverse rotation speed is equal to or greater than the threshold value TH3, the backward movement determination unit 3100 sets the backward movement permission flag to ON (step S35). Processing then returns to the calling process. On the other hand, if the pedal reverse rotation speed is less than the threshold value TH3, the backward movement determination unit 3100 determines whether the pedal reverse rotation speed is smaller than a threshold value TH4 (<TH3, for example, 20 rpm) (step S37). If the reverse pedal rotation speed decreases after the conditions for performing reverse control are met, instead of immediately setting the reverse permission flag to OFF, the reverse pedal rotation speed must decrease enough to fall below the threshold TH4. For example, in order to prevent chattering, the current state is maintained (the retreat permission flag remains on). Therefore, when the pedal reverse rotation speed is less than the threshold value TH4, the backward movement determination unit 3100 sets the backward movement permission flag to OFF (step S39). Processing then returns to the calling process. On the other hand, if the pedal reverse rotation speed is equal to or greater than the threshold value TH4, the process returns to the calling source process without doing anything.

By performing such processing, if the reverse pedal rotation is performed at a speed above a certain level, reverse control is performed.

Returning to the description of the process in FIG. 5, next, the reverse determination unit 3100 may execute a reverse control confirmation process in addition to the reverse determination process (step S5). This processing is optional. Here, it is assumed that nothing is performed and the process moves on to the next process, but an example of the process when it is executed will be described later.

Then, the control unit 3200 determines whether the backward permission flag is set to on (step S7). If the reverse permission flag is set to OFF, the reverse control according to this embodiment is not performed, and therefore the control unit 3200 sets the output torque according to the conventional method (step S11). A detailed explanation will be omitted here. The process then moves to step S13.

On the other hand, if the reverse permission flag is set to on, the control unit 3200 executes output torque setting processing (step S9). For example, a fixed output torque may be set. Alternatively, the output torque may be set depending on the tire rotation speed, for example.

In this embodiment, the output torque is set as shown in FIG. 7, for example. The horizontal axis in FIG. 7 represents the absolute value of the tire rotational speed in reverse rotation (|tire rotational speed|) [km/h], and the vertical axis represents the output torque [Nm]. Note that the tire rotation speed for forward rotation is represented by a positive value, and the tire rotation speed for reverse rotation is represented by a negative value.

In the case of curve a representing the first example, the output torque τ12 is obtained when |tire rotation speed|=0, and the output torque τ12 is maintained until |tire rotation speed|=Sth12 (for example, 2 km/h). When |tire rotation speed| exceeds Sth12, the output torque decreases as |tire rotation speed| increases, and when |tire rotation speed| = Sth13 (for example, 2.5 km/h), the output torque becomes zero. . Let Sth13 be called the upper limit value of |tire rotation speed|.

In addition, in the case of curve b (dotted line) showing the second example, when |tire rotation speed|=0, the output torque is τ11, and when |tire rotation speed| exceeds 0, the output torque When the output torque decreases and |tire rotation speed| reaches Sth11 (for example, 1 km/h), the output torque becomes τ12. If |tire rotation speed| increases from this, it is the same as curve a here.

Curves a and b are only examples, and other curves may be employed. Further, in the example of FIG. 7, three ranges are set for |tire rotation speed|, but the range is not limited to three.

Note that, although this is an option, the output torque may be changed over time depending on the tire rotation speed. For example, the gain by which the output torque is multiplied is changed depending on the elapsed time from the time when the backward permission flag was turned on. An example of this is shown in FIG. The horizontal axis in FIG. 8 represents time [s], and the vertical axis represents gain.

In the example of FIG. 8, the gain linearly increases to 1 until time TH21 (for example, 1 second) has elapsed from the time when the backward permission flag was turned on, and then remains at 1. In this way, since the vehicle gradually moves backward, the impact on the passenger due to the backward movement can be alleviated.

Note that the increase may be made not linearly but along some kind of curve.

FIG. 9 shows an output torque setting process for realizing the matters shown in FIGS. 7 and 8.

The control unit 3200 controls the tire rotation speed (a negative value in the case of reverse rotation) in three predetermined ranges (a first range (0 or less - Sth11 or more), a second range (less than -Sth11) in the example of FIG. -Sth12 or more) and a third range (less than -Sth12 - Sth13 or more)) (FIG. 9: Step S51).

Then, the control unit 3200 determines whether the tire rotation speed falls within any predetermined range (step S53). If the tire rotational speed does not fall within any predetermined range, the control unit 3200 sets the output torque to 0 (step S57). The process then moves to step S59.

On the other hand, when the tire rotation speed falls within any predetermined range, the control unit 3200 sets the output torque according to the tire rotation speed within the corresponding predetermined range (step S55). For example, in the case of curve b, if it falls within the first range, the output torque decreases according to a predetermined function as |tire rotation speed| increases, and if it falls within the second range, |tire rotation speed| The output torque is set according to a predetermined function that outputs a constant output torque regardless of |, and when it falls within the third range, the output torque is set according to a predetermined function that reduces the output torque as |tire rotation speed| increases. The process then moves to step S59.

Further, the control unit 3200 determines whether or not the elapsed time since the backward permission flag is set to on is less than the threshold TH21 (step S59). If the elapsed time is equal to or greater than the threshold TH21, the process returns to the calling process. On the other hand, if the elapsed time is less than the threshold TH21, the control unit 3200 corrects the output torque by multiplying the output torque by a gain G (<1) that changes depending on the elapsed time (step S61). In the example of FIG. 9, the gain G is multiplied so that the longer the elapsed time, the closer it becomes to 1.

In this way, an appropriate output torque can be set. Note that by setting the output torque according to the tire rotational speed as shown in FIG. 7, it is possible to move the electrically assisted bicycle 1 backward while taking into consideration the rider's psychology and safety when backing up.

Additionally, by setting a relatively large output torque when the vehicle is stopped, it is possible to avoid situations where the vehicle cannot start on a slope or step. Additionally, as the tire rotation speed increases, the output torque becomes zero, which prevents the vehicle from moving too far backwards.

Returning to the description of the process in FIG. 5, the control unit 3200 determines whether the backward permission flag is on (step S13). If the backward permission flag is off, the control unit 3200 sets the motor rotation direction to forward rotation (step S17). This is the same as before. The process then moves to step S19.

On the other hand, if the backward permission flag is on, the control unit 3200 sets the motor rotation direction to reverse rotation (step S15). The process then moves to step S19.

The control unit 3200 then controls the motor 105 according to the settings (step S19). If the backward permission flag is on, the motor drive timing generator 1026, variable delay circuit 1025, and FET bridge 1030 are controlled so as to generate the set output torque in reverse rotation.

The processes from step S3 to step S19 as described above are repeated every unit time, for example, until the power switch is turned off and the process ends (step S21).

By performing the processing described above, it becomes possible to back up while riding in the electrically assisted vehicle.

[Embodiment 2]
In this embodiment, an example of the backward determination process performed when the pedal rotation sensor 104 is a sensor that cannot detect the direction of rotation will be described.

FIG. 10 shows the backward determination process B according to this embodiment. Since the rotation direction cannot be detected, the pedal rotation speed always takes a positive value. Further, it is assumed that the torque sensor 103 does not detect torque while the pedal is rotating in the reverse direction.

The backward determination unit 3100 determines whether the tire rotation speed is equal to or lower than a threshold value TH1 (for example, 1 km/h) (FIG. 10: Step S71). It is assumed that the tire rotation speed has a positive value when rotating in the forward direction, and a negative value when rotating in the reverse direction. In this step, it is determined whether or not the electrically assisted bicycle 1 is stopped, and it may be determined whether the tire rotation speed is within a predetermined range including 0.

If the tire rotation speed is not equal to or lower than the threshold value TH1, the reversing determination unit 3100 sets the reversing permission flag to OFF (step S83). Processing then returns to the calling process. On the other hand, if the tire rotational speed is less than or equal to the threshold value TH1, the reverse determination unit 3100 determines whether the pedal input torque is less than or equal to the threshold value TH2 (for example, 10 Nm) (step S73). This step also confirms that almost no torque is being input, that is, that the pedal is not being rotated in the forward direction. The threshold value TH2 is, for example, a value that is greater than or equal to the torque for preventing false detection (for example, 5 Nm) and less than or equal to the driving permission torque for normal rotation (for example, 15 Nm). If the torque exceeds the threshold TH2, the process moves to step S83.

On the other hand, when the pedal input torque is less than or equal to the threshold value TH2, the reverse determination unit 3100 determines whether the pedal rotation speed is greater than or equal to the threshold value TH3 (for example, 30 rpm) (step S75). If the conditions of steps S71 and S73 are satisfied, it can be considered that the vehicle is stopped, and if the pedal rotation speed is equal to or higher than the threshold value TH3, the pedal can be rotated in the reverse direction. It is determined that this indicates the passenger's intention to move backwards.

If the pedal rotation speed is equal to or greater than the threshold value TH3, the backward movement determination unit 3100 sets the backward movement permission flag to ON (step S77). Processing then returns to the calling process. On the other hand, if the pedal rotation speed is less than the threshold value TH3, the backward determination unit 3100 determines whether the pedal rotation speed is less than the threshold value TH4 (step S79). If the pedal rotation speed is less than the threshold value TH4, the backward movement determination unit 3100 sets the backward movement permission flag to OFF (step S81). If the pedals are not rotated sufficiently, the reverse permission flag is turned off. Processing then returns to the calling process. On the other hand, if the pedal rotation speed is equal to or greater than the threshold value TH4, the process returns to the calling process without doing anything. This is to maintain the status quo.

By performing the above processing, even if the pedal rotation sensor 104 cannot detect the direction of rotation, it is possible to detect a state in which the pedal is rotated in the opposite direction while the vehicle is stopped.

[Embodiment 3]
In order to more reliably detect the passenger's intention to retreat, a retreat determination process C as shown in FIGS. 11 and 12 may be executed, for example. Note that this embodiment assumes a case where the pedal rotation sensor 104 cannot detect the rotation direction.

The backward determination unit 3100 determines whether the pedal rotation speed is less than a threshold value TH34 (for example, 20 rpm) (FIG. 11: Step S91). If the pedal rotation speed is less than the threshold value TH34, the backward movement determination unit 3100 clears the pedal rotation angle amount (step S93). The pedal rotation angle amount is initially the cumulative rotation angle amount after detecting the pedal rotation, and thereafter is the cumulative rotation angle amount of the pedal rotation detected after being cleared. Further, the backward determination unit 3100 sets the backward permission flag to OFF (step S95). Processing then returns to the calling process.

On the other hand, if the pedal rotation speed is not less than the threshold TH34, the backward determination unit 3100 determines whether the pedal rotational angular acceleration is equal to or higher than the threshold TH36 (for example, 3.14 rad/s ² =180°/s ² ). (Step S97). If the pedal rotational angular acceleration is equal to or greater than the threshold value TH36, the process moves to step S93. When the pedal is being pedaled stably at a constant speed, the pedal rotational angular acceleration is less than the threshold value TH36. On the other hand, if the pedal is rotating for some reason, the pedal rotational angular acceleration will not be at a constant speed but will become faster or slower, and the pedal rotational angular acceleration will be equal to or higher than the threshold value TH36. That is, in steps S91 and S97, it is first determined whether or not the pedal is being rotated stably at a constant speed or higher.

If the pedal rotational angular acceleration is less than the threshold TH36, the reverse determination unit 3100 determines whether the current amount of pedal rotational angle is less than the threshold TH35 (for example, 360°) (step S99). In this embodiment, if the pedal is rotated by a predetermined angle (for example, one revolution (=360°)) or more stably at a certain speed or higher, it is determined that the passenger intends to go backwards. . If the current amount of pedal rotation angle is less than the threshold value TH35, the process moves to step S95. On the other hand, if the pedal rotation angle amount is equal to or greater than the threshold value TH35, the process shifts to the process shown in FIG. 12 via terminal A.

Moving on to the description of the process in FIG. 12, the backward determination unit 3100 determines whether the tire rotation speed exceeds a threshold value TH31 (for example, 1 km/h) (FIG. 12: Step S101). If the tire rotation speed exceeds the threshold value TH31, the process moves to step S95 in FIG. 11 via terminal B. On the other hand, when the tire rotational speed is less than or equal to the threshold value TH31, the reversing determination unit 3100 determines whether or not the tire rotational speed is less than the threshold value TH32 (for example, −2.5 km/h) (step S103). If the tire rotation speed is less than the threshold value TH32, the process moves to step S95 in FIG. 11 via terminal B.

If the tire rotational speed is equal to or higher than the threshold value TH32, the vehicle is almost stopped, and the reverse determination unit 3100 determines whether the pedal input torque is equal to or higher than the threshold value TH33 (for example, 10 Nm) (step S105). If the pedal input torque is equal to or greater than the threshold value TH33, the process moves to step S95 in FIG. 11 via terminal B. If the pedal input torque is less than the threshold TH33, there is almost no pedal input torque, and the reverse determination unit 3100 determines whether the pedal rotation speed is less than the threshold TH38 (for example, 30 rpm) (step S107). If the pedal rotation speed is less than the threshold TH38, the process returns to the calling process via terminal C.

On the other hand, if the pedal rotation speed is equal to or greater than the threshold value TH38, the reverse determination unit 3100 sets the reverse permission flag to ON (step S109). The process then returns via terminal C to the calling process.

If step S107 is combined with step S91, it is similar to the combination of steps S75 and S79 in FIG. 10. Steps S101 and S103 correspond to step S71 in FIG. 10. Step S105 is similar to step S73. That is, the passenger's intention to retreat is reliably identified in the portion shown in FIG. Note that even if the pedal rotation sensor 104 capable of detecting the direction of rotation is employed, the determination as shown in FIG. 11 as to whether or not the pedal has been stably rotated at a certain speed or above and at a predetermined angle or more is carried out. You can do it like this.

[Embodiment 4]
Similar to the third embodiment, in order to more reliably detect the passenger's intention to retreat, a retreat determination process D as shown in FIG. 13 (and FIG. 12) may be executed, for example. Note that this embodiment also assumes a case in which the pedal rotation sensor 104 cannot detect the rotation direction.

The backward determination unit 3100 determines whether the pedal rotation angle amount is less than a threshold value TH35 (step S111). If the pedal rotation angle amount is less than the threshold TH35, the backward determination unit 3100 further determines whether the elapsed time for measuring the pedal rotation angle amount has exceeded the threshold TH37 (for example, 3 seconds) (step S113). . If the elapsed time is less than the threshold TH37, the process moves to step S117.

On the other hand, if the elapsed time is equal to or greater than the threshold value TH37, the backward determination unit 3100 clears the pedal rotation angle amount (step S115). In this way, if the pedal has not rotated by a predetermined angle or more within a predetermined time, no other judgment is made. Then, the reverse determination unit 3100 sets the reverse permission flag to OFF (step S117). Processing then returns to the calling process.

On the other hand, if the pedal rotation angle amount is equal to or greater than the threshold value TH35, that is, if the pedal has rotated by a predetermined angle or more within a predetermined time, the backward determination unit 3100 determines whether the pedal rotation speed is less than the threshold value TH34. (Step S119). If the pedal rotation speed is less than the threshold TH34, the rotation speed is too slow, so the backward determination unit 3100 clears the pedal rotation angle amount and the elapsed time for measuring the pedal rotation angle amount (step S121). The process then moves to step S117.

On the other hand, if the pedal rotation speed is equal to or greater than the threshold value TH34, the backward determination unit 3100 determines whether the pedal rotational angular acceleration is equal to or greater than the threshold value TH36 (step S123). If the pedal rotational angular acceleration is equal to or greater than the threshold value TH36, the process moves to step S121. That is, if stable pedal rotation is not being performed, the process moves to step S121. If the pedal rotational angular acceleration is less than the threshold value TH36, the process shifts to the process in FIG. 12 via terminal A.

The process in FIG. 12 is as described above, but if the process returns to the process in FIG. 13 via terminal B, the process moves to step S121. Furthermore, when the process returns to the process shown in FIG. 13 via terminal C, the process directly returns to the calling process.

In this way, when the passenger's backward intention is expressed by the pedal rotation angle within a predetermined period of time, it is reasonable to first make the determination based on the pedal rotation angle amount.

In addition, in FIG. 13, not only the pedal rotation angle amount but also that the pedal be rotated stably at a constant speed or higher is also specified as a requirement.

[Embodiment 5]
When setting the output torque according to the tire rotation speed as shown in Figure 7, the upper limit value of the output torque and the upper limit value of the tire rotation speed that can have an influence when setting the output torque are stipulated. . Although such an upper limit value may be fixed, it may also be set depending on the number of rotations of the pedal in reverse rotation, for example.

FIG. 14 shows an example in which the upper limit value of the output torque is set according to the number of rotations of the pedal in reverse rotation. The vertical axis in FIG. 14 represents the upper limit value [Nm] of the output torque, and the horizontal axis represents the pedal reverse rotation speed [rpm]. Not only when the direction of pedal rotation can be detected, but even if the direction of pedal rotation cannot be detected, if the reverse permission flag can be set on, the pedal rotation speed at that time can be treated as the pedal reverse rotation speed. good.

In the example shown in Fig. 14, the upper limit value of the output torque is 0 until the pedal reverse rotation speed reaches Pth1, and when the pedal reverse rotation speed exceeds Pth1, the output torque increases linearly up to the upper limit output torque τmax according to the pedal reverse rotation speed. To increase. When the pedal reverse rotation speed exceeds Pth2, the upper limit output torque τmax is maintained.

It is not limited to the curve shape shown in FIG. 14, but may be changed in other curve shapes.

Further, FIG. 15 shows an example in which the upper limit value [km/h] of |tire rotation speed| for reverse rotation is set according to the pedal rotation speed for reverse rotation. The vertical axis in FIG. 15 represents the upper limit of |tire rotation speed| of reverse rotation, and the horizontal axis represents the pedal reverse rotation speed [rpm].

In the example of FIG. 15, the upper limit of |tire rotation speed| is maintained at a predetermined value Sy until the pedal reverse rotation speed reaches Pth1, but when the pedal reverse rotation speed exceeds Pth1, the upper limit value of |tire rotation speed| It increases linearly up to a predetermined value Sx. When the pedal reverse rotation speed exceeds Pth2, it is maintained at a predetermined value Sx.

It is not limited to the curve shape as shown in FIG. 15, but may change in other curve shapes.

For example, in the case of curve a in FIG. 7, as shown in FIG. 16, the upper limit value (dotted line) of |tire rotation speed| changes in the X direction depending on the pedal reverse rotation speed, and the upper limit value (dotted line) of the output torque ( (two-dot chain line) varies in the Y direction.

[Embodiment 6]
Although the embodiment described above does not use the input from the load sensor 108, the upper limit value of the output torque may be adjusted depending on the weight measured by the load sensor 108, for example.

For example, the control unit 3200 sets the upper limit value of the output torque according to the weight represented by the load input. For example, if the weight is 50 kg, the upper limit may be set to about 15 Nm, or if the weight is 100 kg, the upper limit may be set to about 30 Nm.

This makes it possible to smoothly reverse the vehicle regardless of the occupant.

[Embodiment 7]
It is not preferable to perform reverse control when the vehicle is not in the vehicle. In this embodiment, if the load sensor 108 confirms the presence or absence of a passenger, the backward control is performed, and if the presence or absence of the vehicle cannot be confirmed, the backward control is not performed. That is, if the control unit 3200 does not receive a signal indicating that the rider is seated on the saddle, or if it determines that the measured weight is less than a predetermined value (for example, less than 30 kg), the control unit 3200 turns off the backward permission flag. Or, for example, the output torque is set to zero regardless of whether the backward permission flag is on or off. This makes it safer.

[Embodiment 8]
If it is a general bicycle or electric assist bicycle 1, when the electric assist bicycle 1 is pulled backwards by hand without being ridden, the pedals will rotate in the opposite direction even if the user is not pedaling.

If reverse rotation of the pedals is detected and backward control is performed, the electrically assisted bicycle 1 will move backward in an unintended manner.

In order to prevent this, when a reverse rotation is detected that is faster than the pedal rotation speed of the reverse rotation, which is caused by manually pulling the electric assist bicycle 1 backward without riding the bicycle, the present embodiment is applied. Perform reverse control.

That is, based on the relationship between |tire rotation speed| and pedal reverse rotation speed, cases in which reverse control may be permitted and cases in which it should be prohibited are determined.

An example is shown in FIG. In FIG. 17, the horizontal axis represents |tire rotation speed|[km/h], and the vertical axis represents pedal reverse rotation speed [rpm].

In FIG. 17, a dotted line c represents a line where the following equation holds true.
| Tire rotation speed | = Number of reverse pedal rotations x 60 x Gear ratio x Tire circumference Number of reverse pedal rotations = | Tire rotation speed | / 60 / Gear ratio / Tire circumference

In addition, in the case of internal shifting, the gear ratio is the same as the gear ratio of 1st speed even if the shifting is changed. On the other hand, in the case of external gear shifting, changing the gear changes the gear ratio for that gear. Therefore, the gear ratio may be calculated as the maximum gear ratio.

In FIG. 17, by detecting a pedal reverse rotation speed that exceeds the pedal reverse rotation speed corresponding to |tire rotation speed| in the above equation, it can be determined that the pedals are being reversely rotated.

In this embodiment, a margin is set, and if the reverse pedal rotation speed is detected in the permitted area above the solid straight line d, which exceeds the dotted line c by the margin, it is confirmed that the pedals are being pedaled in reverse rotation. do. On the other hand, if the reverse pedal rotation speed within the prohibited area below straight line d is detected, it is determined that the vehicle is not riding.

Similarly, if |tire rotation speed| that is lower than |tire rotation speed| calculated from the pedal rotation speed in the reverse direction in the above equation is detected, it can be determined that the pedals are being reversely rotated. A margin may also be set in this case.

Therefore, in this embodiment, the process shown in FIG. 18 is executed as the confirmation process (step S5).

That is, the reverse determination unit 3100 determines whether the reverse permission flag is set on (FIG. 18: Step S131). If the retreat permission flag is off, the process returns to the calling source.

On the other hand, when the reverse permission flag is on, the reverse determination unit 3100 determines whether the reverse pedal rotation speed is equal to or less than the reverse pedal rotation speed + margin calculated from |tire rotation speed| Step S133). If this condition is not met, it means that the permission area has been entered, and the process returns to the calling process. Note that the conditions in step S133 may be based on the tire rotation speed instead of the pedal reverse rotation speed. Alternatively, the determination may be made based on an index value obtained by modifying the above equation.

On the other hand, if this condition is satisfied, the vehicle has entered the prohibited area, so the reverse determination unit 3100 sets the reverse permission flag to OFF (step S135). Then it returns to the calling process.

By doing so, it becomes possible to confirm that the passenger is pedaling in the opposite direction without using the load sensor 108.

Although the present embodiment has been described on the assumption that the electrically assisted bicycle 1 is not provided with a differential gear, the above-described processing works effectively even if a differential gear is provided.

[Embodiment 9]
It is not necessary to make a strict determination as in the eighth embodiment, but a similar determination may be made in a simplified manner. For example, in reverse rotation, the threshold value can be calculated by calculating the reverse pedal rotation speed using the above formula and adding a margin based on the upper limit value (for example, [5 km/h]) of |tire rotation speed|.

For example, if the upper limit of |tire rotational speed|=5 km/h, the gear ratio is 1.6, and the tire circumference is 2 m, the reverse pedal rotation speed is calculated to be 26 [rpm]. By adding a margin to this value, the threshold value Pth11 can be set.

That is, as shown in FIG. 19, the threshold value Pth11 of the pedal reverse rotation speed is calculated based on the upper limit value Tth11 of |tire rotation speed|, so that when |tire rotation speed| , Pth11 or more is a permitted area, and the rest is a prohibited area.

Therefore, confirmation processing B as shown in FIG. 20 is executed.

That is, the reverse determination unit 3100 determines whether the reverse permission flag is set on (FIG. 20: Step S141). If the retreat permission flag is off, the process returns to the calling source.

On the other hand, if the reverse permission flag is on, the reverse determination unit 3100 determines whether the reverse pedal rotation speed is smaller than the threshold value Pth11 set as described above (step S143). If this condition is not met, it means that the permission area has been entered, and the process returns to the calling process. Since the threshold value may change depending on the gear ratio, the maximum gear ratio may be used as the gear ratio.

On the other hand, if this condition is satisfied, the vehicle has entered the prohibited area, so the reverse determination unit 3100 sets the reverse permission flag to OFF (step S145). Then it returns to the calling process.

By doing so, it becomes possible to easily confirm that the passenger is pedaling in the reverse direction without using the load sensor 108.

Note that the confirmation process B may be omitted, for example, by adopting the same value as Pth11 for the threshold value TH34 in FIG. 11.

Although the embodiments of the present invention have been described above, the present invention is not limited thereto. For example, depending on the purpose, any technical features of the embodiments described above may be combined, or any technical features of the embodiments described above may be deleted.

For example, the confirmation process and the retreat determination process may be integrated rather than separated. It is also possible to include a part of the confirmation process in the backward determination process, or conversely, include a part of the backward determination process in the confirmation process.

Furthermore, the functional block diagram described above is an example, and one functional block may be divided into a plurality of functional blocks, or a plurality of functional blocks may be integrated into one functional block. Regarding the processing flow, the order of steps may be changed or a plurality of steps may be executed in parallel, as long as the processing content remains the same.

The arithmetic unit 1021 may be partially or entirely implemented using a dedicated circuit, or may implement the functions described above by executing a program prepared in advance.

The type of sensor described above is just an example, and other sensors that can obtain the parameters described above may be used. Note that the installation location may also be changed in accordance with the gist of the parameters measured by the sensor.

The embodiments described above can be summarized as follows.

The motor control device according to the present embodiment includes (A) a drive unit that drives a motor of an electrically assisted vehicle, and (B) when detecting reverse rotation of a pedal that satisfies a first condition, causes the electrically assisted vehicle to move backward. and a control section that controls the drive section. In this way, it becomes possible to back up while riding in the electrically assisted vehicle.

The control unit described above detects reverse rotation of the pedal that satisfies the first condition based on the pedal rotation direction and pedal rotation speed, or the pedal rotation speed, tire rotation speed, and pedal input torque. You can do it like this. Regardless of whether the direction of rotation of the pedal can be detected or not, reverse rotation of the pedal that satisfies the first condition can be detected.

Further, the control unit described above controls the pedal that satisfies the first condition based on the reverse pedal rotation speed, the pedal rotation angle amount, the pedal rotation angular acceleration, the tire rotation speed, and the pedal input torque. Reverse rotation may also be detected. By using such a parameter group, it becomes possible to reliably detect the reverse rotation of the pedal that satisfies the first condition.

Furthermore, the control unit described above sets a second condition regarding the number of pedal rotations for reverse rotation (for example, the number of reverse pedal rotations is less than a threshold value) and a third condition regarding the amount of pedal rotation angle (for example, a pedal rotation number less than a threshold value). a fourth condition for the pedal rotational angular acceleration (e.g., pedal rotational angular velocity greater than or equal to a threshold value), a fifth condition for tire rotational speed (e.g., more than a threshold value |tire rotational speed|), It may be determined that the first condition is not satisfied when at least one of the sixth condition regarding input torque (for example, pedal input torque equal to or higher than a threshold value) is satisfied.

Further, the third condition, or the second condition and the fourth condition may be determined preferentially. This is for efficiency of judgment.

Furthermore, the control unit described above determines whether, when the amount of pedal rotation angle in a certain period of time satisfies the second condition, other conditions including the third condition regarding the number of rotations of the pedal in reverse rotation are satisfied. It may be determined whether the first condition is satisfied by determining. This is effective when the passenger's intention to retreat is expressed by the amount of pedal rotation angle.

In addition, the control unit described above includes a third condition regarding the pedal rotation angle amount while the reverse rotation of the pedal is performed at a predetermined rotation speed or more and with a stability that satisfies the second condition. It may be determined whether or not the first condition is satisfied by determining whether or not the condition is satisfied. If it is important that the pedal is being pedaled in reverse rotation at a constant speed or higher and stably, such a determination may be made.

Furthermore, the control unit described above may determine the output torque of the motor based on the tire rotation speed. For example, in reverse rotation, the slower the |tire rotation speed|, the larger the output torque will be to increase the output torque, making it smoother to start backwards, and the faster the |tire rotation speed|, the smaller the output torque will be, allowing the vehicle to retreat safely.

Note that the control section described above may change the output torque depending on time. This makes it possible to soften the impact when starting in reverse, for example.

Furthermore, the above-described control unit may prohibit control to move the electrically assisted vehicle backwards if no entry into the electrically assisted vehicle is detected. This is to make it safer.

In addition, the control unit described above determines the relationship between the tire rotation speed calculated based on the rotation speed of the reverse rotation pedal and the current tire rotation speed, or the relationship between the tire rotation speed calculated based on the reverse rotation pedal rotation speed, or the reverse rotation pedal rotation speed calculated based on the current tire rotation speed. Based on the relationship between the rotation speed and the current pedal rotation speed for reverse rotation, it may be determined whether or not to control the electrically assisted vehicle to move backward. This makes it possible to determine whether or not the passenger is intentionally rotating the pedals in the reverse direction.

Furthermore, the control unit described above may adjust at least one of the upper limit value of the output torque of the motor and the upper limit value of the tire rotation speed based on the pedal rotation speed of reverse rotation. This is to cause the vehicle to move backward according to the passenger's intention.

Further, the control section described above may adjust the upper limit value of the output torque of the motor based on the weight of the passenger of the electrically assisted vehicle. For example, this is to enable smooth starting in reverse regardless of the occupant.

3000 Reverse control section 3100 Reverse determination section 3200 Control section

Claims (8)

A drive unit that drives the motor of an electrically assisted vehicle;
Control for controlling the drive unit to move the electrically assisted vehicle backward when detecting reverse rotation of the pedal that satisfies at least a first condition including the condition that the rotation speed of the pedal of the electrically assisted vehicle is equal to or higher than a certain value. Department and
has
The control unit includes:
If the current pedal rotation speed for reverse rotation is less than or equal to a first threshold value set based on the current tire rotation speed for reverse rotation or a predetermined tire rotation speed for reverse rotation, or
When the current tire rotation speed during reverse rotation is equal to or higher than a second threshold set based on the current pedal rotation speed during reverse rotation,
Stop the control for reversing the electrically assisted vehicle.
Motor control device. The tire rotation speed and the output torque in the reverse rotation are such that the output torque of the motor is smaller in a predetermined range where the tire rotation speed exceeds 0, compared to when the tire rotation speed in the reverse rotation is 0. The relationship between is set in advance,
The control unit sets the output torque of the motor according to the current tire rotation speed in reverse rotation based on the relationship.
The motor control device according to claim 1. The tire rotation speed and the output torque in the reverse rotation are such that the output torque of the motor is smaller in a predetermined range where the tire rotation speed exceeds 0, compared to when the tire rotation speed in the reverse rotation is 0. The first relationship is set in advance,
A second relationship between the reverse pedal rotation speed and the output torque upper limit value is set in advance, including a portion in which the higher the reverse rotation pedal rotation speed, the larger the output torque upper limit value. ,
The control unit includes:
setting the output torque of the motor according to the current tire rotation speed in reverse rotation based on the first relationship;
Based on the second relationship, the upper limit value of the output torque is set according to the current pedal rotation speed of reverse rotation.
The motor control device according to claim 1. The output torque of the motor becomes smaller in a predetermined range where the tire rotation speed exceeds 0 compared to when the tire rotation speed during reverse rotation is 0, and becomes 0 at an upper limit value of the tire rotation speed during the reverse rotation. A first relationship between the tire rotation speed in the reverse rotation and the output torque is set in advance,
A second difference between the pedal rotation speed in reverse rotation and the upper limit value of tire rotation speed in reverse rotation, including a portion where the higher the pedal rotation speed in reverse rotation, the larger the upper limit value of tire rotation speed in reverse rotation. The relationship is preset,
The control unit includes:
setting the output torque of the motor according to the current tire rotation speed in reverse rotation based on the first relationship;
Based on the second relationship, an upper limit value of the tire rotation speed during the reverse rotation is set according to the current pedal rotation speed during the reverse rotation.
The motor control device according to claim 1. A drive unit that drives the motor of an electric assist vehicle that cannot detect the direction of rotation of the pedal ;
The tire rotation speed of the electrically assisted vehicle is below a first threshold value, the pedal input torque is below a second threshold value which is a value below drive permission torque, and the rotation speed of the pedal is above a third threshold value. a control unit that controls the drive unit to move the electrically assisted vehicle backward when it is determined that the condition is satisfied ;
A motor control device having a A drive unit that drives the motor of an electrically assisted vehicle that cannot detect the direction of rotation of the pedal ;
The pedal is rotated at a predetermined angle or more at a constant rotation speed or more and stably, the electric assist vehicle is in a stopped state, and the pedal input torque is less than or equal to a first threshold value, which is a value less than or equal to the driving permission torque, and a control unit that controls the drive unit to move the electrically assisted vehicle backwards when it is determined that the condition that the rotation speed of the pedal is equal to or higher than a second threshold ;
A motor control device having a A drive unit that drives the motor of an electrically assisted vehicle that cannot detect the direction of rotation of the pedal ;
The pedal is rotated by a predetermined angle or more at a predetermined rotation speed or more and stably within a predetermined time, the electric assist vehicle is in a stopped state, and the pedal input torque is less than or equal to a first threshold value, which is a value less than or equal to the driving permission torque. and when it is determined that the condition that the rotation speed of the pedal is equal to or higher than a second threshold value is satisfied , a control unit that controls the drive unit to move the electrically assisted vehicle backward;
A motor control device having a An electrically assisted vehicle comprising the motor control device according to any one of claims 1 to 7 .

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