WO2023053518A1

WO2023053518A1 - Control device for suppressing collision of electrically assisted vehicle and electrically assisted vehicle provided with said control device

Info

Publication number: WO2023053518A1
Application number: PCT/JP2022/013003
Authority: WO
Inventors: 悟清水; 太一 ▲柳▼岡; 康夫保坂
Original assignee: 太陽誘電株式会社
Priority date: 2021-09-30
Filing date: 2022-03-22
Publication date: 2023-04-06

Abstract

Provided is a control device for electrically assisted vehicle for executing collision suppression appropriate for an operation mode of an electrically assisted vehicle such as an electrically assisted bicycle, the control device comprising: a collision prediction unit which executes collision prediction on the basis of an output from a front monitoring sensor; and a control unit which determines whether or not a user is executing a predetermined pedal operation when the collision prediction unit predicts that a possibility of a collision is higher than or equal to a predetermined level and stops, when the predetermined pedal operation is being executed, control of decelerating the electrically assisted vehicle and simultaneously reduces a driving force of motor drive or stops the motor drive.

Description

Control device for collision suppression of electrically assisted vehicle and electrically assisted vehicle equipped with the control device

The present invention relates to collision suppression technology for electrically assisted vehicles.

In addition to assisting human power with the driving force of the motor, when the user instructs to decelerate by operating the brake, etc., or when coasting on a downhill, etc., the back electromotive force of the motor is used to generate electricity and charge the battery. Power-assisted bicycles with functions are known.

An electrically assisted bicycle supplies driving force with a motor according to human power, and the body is lighter than an automobile, etc., so it is easy to follow the operation of the person, and it is safe to ride as the user intends. Although it is a simple vehicle, it relies on the user's attention and operation to respond to the surrounding environment.

On the other hand, vehicles equipped with automatic braking functions to detect obstacles using sensor technology and reduce collisions have already been commercialized and are in widespread use. Although these automatic braking functions for collision mitigation for automobiles have been proven to contribute to safety, most of them are shaped according to the driving conditions of four-wheeled vehicles. That is, assuming that the vehicle travels on a motorway with few obstacles, the presence of obstacles is irregular, and since the vehicle has four wheels, stability is maintained to some extent even when sudden braking is performed.

However, for two- or three-wheeled motor-assisted bicycles, which may run on sidewalks with a lot of pedestrian traffic, and which are premised on avoiding obstacles after slowing down rather than stopping toward them. , it is not preferable to apply the automatic braking function for collision mitigation for automobiles.

For example, Patent Document 1 discloses a collision prevention control device that includes a control device that outputs a brake actuation signal to brake a motor when the result of processing information detected by an obstacle sensor provided in a vehicle satisfies a predetermined condition. disclosed. However, with this technology, braking is forcibly applied based on the information detected by the obstacle sensor. For example, even if the user recognizes the obstacle and intends to avoid it after approaching it, the braking will hinder the vehicle from traveling. As a result, convenience is lost.

For example, in Patent Document 2, when a stationary object or an object moving at a low speed is detected by monitoring the front, it is determined that the vehicle is traveling in a warning area, and the urgency is determined from the accelerator operation speed and accelerator pedal operation while the vehicle is traveling in the warning area. A technique is disclosed for determining and performing automatic braking prior to brake operation. This technology reads the user's intentions to some extent and then automatically applies the brakes. It is difficult for the user to maintain balance in a low-speed state, and this control is not suitable for a vehicle that is supposed to avoid obstacles while maintaining a certain speed.

JP-A-4-96603 JP-A-11-255087

Therefore, according to one aspect of the present invention, it is an object of the present invention to provide a collision suppression technique suitable for the driving mode of an electrically assisted vehicle such as an electrically assisted bicycle.

A control device for an electrically assisted vehicle according to the present invention includes: (A) a collision prediction unit that predicts a collision based on an output from a forward monitoring sensor; When this is predicted, it is determined whether or not a predetermined pedal operation is performed by the user, and if the predetermined pedal operation is performed, the control for decelerating the electrically assisted vehicle is stopped and the motor is driven. and a control unit for reducing the driving force or stopping the motor drive.

FIG. 1 is a diagram showing the appearance of a power-assisted bicycle according to an embodiment. FIG. 2 is a diagram showing a configuration example of a motor control device. FIG. 3 is a diagram showing a functional configuration of portions according to the embodiment. FIG. 4 is a diagram showing a processing flow representing operation contents in the first embodiment. FIG. 5 is a diagram showing a time chart in the first embodiment. FIG. 6 is a diagram showing a processing flow representing operation contents in the second embodiment. FIG. 7 is a diagram showing a time chart in the second embodiment. FIG. 8 is a diagram showing a processing flow representing operation contents in the third embodiment. FIG. 9 is a diagram showing a processing flow representing operation contents in the third embodiment.

Embodiments of the present invention will be described below using an example of an electrically assisted bicycle, which is an example of an electrically assisted vehicle. However, the embodiments of the present invention are not limited to application only to electrically assisted bicycles, and can also be applied to control devices for mobile bodies (for example, carts, wheelchairs, etc.) that move according to human power. .

[Embodiment 1]
FIG. 1 is an external view showing an example of an electrically assisted bicycle, which is an example of an electrically assisted vehicle according to the present embodiment. This electrically assisted bicycle 1 is equipped with a motor drive device. The motor driving device has a battery pack 101 , a motor control device 102 , a torque sensor 103 , a pedal rotation sensor 104 , a motor 105 , an operation panel 106 , a brake sensor 107 and a forward monitoring sensor 108 .

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

The battery pack 101 is, for example, a lithium-ion secondary battery, but may 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 electric power to the motor 105 via the motor control device 102, and also charges the battery pack 101 with regenerated electric power from the motor 105 via the motor control device 102 during regeneration.

The torque sensor 103 is provided around the crankshaft, detects the force applied to the pedal by the driver, and outputs the detection result to the motor control device 102 . Further, the pedal rotation sensor 104 is provided around the crankshaft in the same manner as the torque sensor 103 and outputs a signal corresponding to rotation to the motor control device 102 .

The motor 105 is, for example, a well-known three-phase DC brushless motor, and is attached to the front wheel of the electrically assisted bicycle 1, for example. The motor 105 rotates the front wheels, and the rotor is connected to the front wheels so that the rotor rotates according to the rotation of the front wheels. Further, the motor 105 has a rotation sensor such as a Hall element, and outputs rotor rotation information (that is, a Hall signal) to the motor control device 102 .

The motor control device 102 performs predetermined calculations based on signals from the rotation sensor of the motor 105, the brake sensor 107, the torque sensor 103, the pedal rotation sensor 104, etc., controls the driving of the motor 105, and controls the regeneration by the motor 105. Also controls. Note that, in the embodiment of the present invention, the motor control device 102 performs collision prediction based on the output from the forward monitoring sensor 108, and performs motor control and the like as described below.

The forward monitoring sensor 108 is, for example, a millimeter wave sensor, a camera, or an infrared sensor such as LIDAR (Light Detection And Ranging). Millimeter-wave sensors are capable of stable detection even in bad weather, but the only information they can obtain is the distance to obstacles. Also, if the images captured by the camera are processed, the size and condition of the obstacles can be determined, but the accuracy of detection deteriorates at night or in bad weather. Infrared sensors such as LIDAR can detect angle information and size of obstacles by scanning, but they are expensive. As described above, various forms of sensors can be used for forward monitoring sensor 108, and any form of sensor may be employed in the embodiment of the present invention. The motor controller 102 processes the output data according to aspects of the forward looking sensor 108 to perform collision prediction. The front monitoring sensor 108 is preferably installed in front of the electrically power-assisted bicycle 1 because it monitors the front.

The operation panel 106 accepts, for example, an instruction input regarding the presence or absence of assistance (that is, turning on and off the power switch) and, in the case of assistance, an input such as a desired assist ratio from the passenger. 102. In some cases, the operation panel 106 also has a function of displaying data such as travel distance, travel time, calorie consumption, and regenerative power amount calculated by the motor control device 102 . Also, the operation panel 106 may have a display unit such as an LED (Light Emitting Diode). As a result, the driver is presented with, for example, the charge level of the battery pack 101, the on/off state, the mode corresponding to the desired assist ratio, and the like. Further, based on the output from the forward monitoring sensor 108, the motor control device 102, when predicting that the possibility of a collision is equal to or higher than a predetermined level, causes the operation panel 106 to perform an output informing of danger, or from a speaker. Sound may be output.

FIG. 2 shows a configuration related to the motor control device 102 according to this embodiment. The motor 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) for switching the U-phase of the motor 105, and a high-side FET (Svh) and a low-side FET (Svl) for switching the V-phase of the motor 105. ), and a high-side FET (Swh) and a low-side FET (Swl) for switching the W phase of the motor 105 . The FET bridge 1030 is a motor drive unit and constitutes a part of a complementary switching amplifier.

Further, the controller 1020 includes 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, and a brake input unit 1028. , an AD input section 1029 for AD (Analog-Digital) conversion of the output voltage of the battery pack 101 , and a sensor input section 1023 .

The calculation unit 1021 receives input from the operation panel 106 (for example, assist on/off), input from the brake input unit 1028 (for example, brake on/off), input from the pedal rotation input unit 1022, and motor rotation input unit. 1024, the input from the torque input unit 1027, the input from the sensor input unit 1023, and the input from the AD input unit 1029 are used to perform a predetermined calculation, and the motor drive timing generation unit 1026 and the variable delay circuit 1025 Output to Note that the calculation unit 1021 has a memory 10211, and the memory 10211 stores various data used for calculation, data during processing, and the like. Furthermore, the arithmetic unit 1021 may be implemented by a processor executing a program, and in this case the program may be recorded in the memory 10211 . Also, the memory 10211 may be provided separately from the calculation unit 1021 .

Pedal rotation input section 1022 digitizes the pedal rotation phase angle (also called crank rotation phase angle; it may also include a signal representing the direction of rotation) from pedal rotation sensor 104 and outputs it to calculation section 1021 . do. A motor rotation input unit 1024 digitizes a signal (for example, a rotation phase angle, a rotation direction, etc.) related to the rotation of the motor 105 (rotation of the front wheels in this embodiment) from the Hall signal output by the motor 105, and outputs it to the calculation unit 1021. output to Torque input section 1027 digitizes a signal corresponding to the pedaling force from torque sensor 103 and outputs the digitized signal to calculation section 1021 . AD input section 1029 digitizes the output voltage from the secondary battery and outputs it to arithmetic section 1021 .

The brake input unit 1028 digitizes the signal indicating whether or not the brake is applied from the brake sensor 107 and outputs the digitized signal to the calculation unit 1021 . Sensor input section 1023 digitizes the signal from front monitoring sensor 108 in accordance with the form of front monitoring sensor 108 and inputs the digitized signal to calculation section 1021 .

The computation unit 1021 outputs the lead angle value to the variable delay circuit 1025 as a computation 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 the Hall signal 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 generator 1026 generates and outputs a switching signal for each FET included in FET bridge 1030 based on the adjusted Hall signal from variable delay circuit 1025 and the PWM code from calculator 1021 . Depending on the calculation result of the calculation unit 1021, the motor 105 may be power driven or may be regeneratively braked. Note that the basic operation of the motor is described in the pamphlet of International Publication No. 2012/086459, etc., and is not the main part of the present embodiment, so the description is omitted here.

Next, FIG. 3 shows an example of a functional configuration realized by executing a predetermined program in the calculation unit 1021. Specifically, calculation unit 1021 implements collision prediction unit 3100 , pedal rotation processing unit 3200 , motor rotation processing unit 3300 , control unit 3400 , and motor control unit 3500 .

The motor rotation processing unit 3300 calculates, for example, the motor rotation speed [rpm] based on the motor rotation input from the motor rotation input unit 1024, and calculates the motor rotation speed as the speed of the electrically power-assisted bicycle 1 (=vehicle speed [km/h ]). Further, the pedal rotation processing unit 3200 calculates, for example, the pedal rotation speed [rpm] based on the pedal rotation input from the pedal rotation input unit 1022, and converts the pedal rotation speed into the running speed [km/h]. More specifically, the travel speed based on the pedal rotation is calculated by multiplying the pedal rotation number by the distance traveled by one pedal rotation. If the power-assisted bicycle 1 is equipped with a transmission, the distance traveled by one rotation of the pedal may differ depending on the gear ratio. In such a case, the gear ratio is calculated by, for example, the number of revolutions of the motor/the number of revolutions of the pedal, and the value of the distance traveled by one rotation of the pedal is dynamically adjusted by using the gear ratio.

The collision prediction unit 3100 performs collision prediction to determine whether the possibility of collision is equal to or higher than a predetermined level, based on the forward monitoring sensor input from the sensor input unit 1023 that receives the signal from the forward monitoring sensor 108 . For example, when it is determined that the distance between the power-assisted bicycle 1 and the obstacle is within 10 m, for example, the possibility of collision is predicted to be at or above a predetermined level. It should be noted that determination may be made by adding other conditions in addition to the distance.

When the collision prediction unit 3100 predicts that the possibility of a collision is equal to or higher than a predetermined level, the control unit 3400 calculates the pedal input torque, the traveling speed output from the pedal rotation processing unit 3200, and the motor rotation processing based on the pedal rotation. Based on the vehicle speed and the like output from the unit 3300, it determines whether to execute or stop motor driving, or to execute or stop automatic braking by regenerative braking or the like, and issues an instruction therefor. The motor control unit 3500 controls motor driving and regenerative braking of the motor 105 according to instructions. In addition to regenerative braking, braking that consumes regenerative current in the motor 105 without flowing regenerative current to the battery, and in some cases, braking using a mechanical brake such as pressing the brake pad against the rim of the tire. be.

　Hereinafter, the contents of the operation will be described in detail using FIGS. 4 and 5. Note that steps S1 to S13 are executed at predetermined control cycles.

First, the collision prediction unit 3100 executes collision prediction based on the forward monitoring sensor input (Fig. 4: step S1). As described above, an obstacle is specified, and it is determined whether or not the condition that the distance to the obstacle is within 10 m, for example, is satisfied. When the collision prediction unit 3100 predicts that the possibility of collision is less than the predetermined level (step S3: No route), the motor control unit 3500 executes normal control (step S11). In other words, the control unit 3400 does not instruct to execute or stop motor driving or to execute or stop automatic braking, and the motor control unit 3500 controls the motor so as to perform normal motor driving or regenerative braking. Then, the process moves to step S13.

On the other hand, when the collision prediction unit 3100 outputs to the control unit 3400 the output indicating that the possibility of collision is equal to or higher than the predetermined level (step S3: Yes route), the control unit 3400 determines whether a predetermined pedal operation is being performed. is confirmed (step S5). The predetermined pedal operation is, for example, a predetermined pedal operation indicating the user's intention to continue running. That is, in step S5, it is determined whether or not the user has an intention to continue running.

More specifically, such a predetermined pedal operation is determined under the following conditions.
1) The difference between the running speed and the vehicle speed based on pedal rotation is a predetermined value (eg, 2 km/h) or less 2) The pedal input torque is a predetermined threshold value (eg, 5 Nm) or more If these conditions are met: This is because the driver is pedaling so as to maintain the current vehicle speed or increase the vehicle speed. Only 1) or only 2) may be set as a condition.

Furthermore, instead of condition 1),
3) The condition that the number of pedal rotations is equal to or greater than a predetermined threshold value (for example, 5 rpm) may be employed to check whether the user is rotating the pedals frequently. Furthermore, either 1) or 3) or 2) may be simply determined.

If the predetermined pedal operation has not been performed (step S5: Yes route), the control unit 3400 instructs to stop the motor drive and perform automatic braking, and the motor control unit 3500 stops the motor drive and performs automatic braking. Execute (step S7). That is, when the user does not indicate the intention to continue running, not only the motor drive is stopped, but also automatic braking is executed to further decelerate the vehicle, thereby reducing the possibility of collision. Then, the process moves to step S13.

On the other hand, when a predetermined pedal operation is performed (step S5: No route), the control unit 3400 instructs to stop motor driving and automatic braking, and the motor control unit 3500 stops motor driving and automatic braking. (step S9). In such a case, since the user has an intention to continue running, the user's intention is prioritized and automatic braking is not performed. This will prevent the vehicle speed from increasing easily, thus improving safety. In some cases, instead of stopping the motor drive, it may be possible to reduce the driving force. Then, the process moves to step S13.

The motor control unit 3500 determines whether or not the end of processing has been instructed by the user turning off the power (step S13). If the end of the process is not instructed, the process returns to step S1. On the other hand, when the end of processing is instructed, the processing ends.

As described above, by focusing not only on the collision prediction result of the collision prediction unit 3100 but also on the pedal operation that expresses the user's intention, safety can be improved while coping with the unique riding style of the electrically power-assisted bicycle 1. be able to

An example of control in the present embodiment will be described using FIG. As schematically shown in the uppermost part of FIG. 5, an obstacle is placed in front of the power-assisted bicycle 1, and the power-assisted bicycle 1 is assumed to be running on a flat ground toward the obstacle. . As shown in FIG. 5(a), the distance between the power-assisted bicycle 1 and the obstacle gradually decreases, and when the distance is within 10 m, the possibility of collision is predicted to exceed a predetermined level. Note that up to (e) in FIG. 5, as a first example, as shown in FIG. 5(b), the predetermined pedal operation is continued even if the distance to the obstacle is within 10 m. Then, as shown in FIGS. 5(c) and 5(d), when the distance to the obstacle is within 10 m and the possibility of collision exceeds a predetermined level, the motor is stopped and automatic braking is also performed. can't break Therefore, as shown in FIG. 5(e), when the distance to the obstacle is within 10 m and the possibility of collision exceeds a predetermined level, the vehicle speed is gradually decelerated from the previous vehicle speed due to the lack of motor drive. will come to

On the other hand, in the second example shown in FIGS. 5(f) to 5(i), as shown in FIG. Immediately before the possibility of a collision is predicted to exceed a predetermined level within 10 m, rotation of a predetermined pedal is stopped as shown in FIG. 5(f). In such a case, when the possibility of collision is predicted to exceed a predetermined level, as shown in FIGS. It will be done. As a result, as shown in FIG. 5(i), when the possibility of collision is predicted to exceed a predetermined level, the vehicle decelerates more rapidly than in the case of FIG. 5(e).

When the possibility of collision is predicted to be at or above a predetermined level, the control unit 3400 turns on a warning lamp provided on the operation panel 106 or the like, outputs a warning sound from a speaker, or the like. The user may be warned.

Also, in the above, "automatic braking stop" and "motor drive stop" are mentioned, but if it has been stopped before that, the control state will continue.

[Embodiment 2]
In the first embodiment, when a predetermined pedal operation is not performed, automatic braking is performed to forcibly decelerate the bicycle. On the contrary, the danger increases. The present embodiment addresses such bicycle characteristics.

　Fig. 6 shows the contents of the operation performed instead of Fig. 4. However, in FIG. 6, the same operation parts as in FIG. 4 are shown with the same step numbers, and only different parts will be explained. In FIG. 6, steps S21 to S25 are added instead of step S7 executed after step S5.

That is, when it is determined in step S5 that the predetermined pedal operation is not performed, the control section 3400 determines whether or not the vehicle speed from the motor rotation processing section 3300 is less than the predetermined threshold TH1 (step S21). ).

　The stability at low speeds is different between an electrically assisted bicycle, such as a road bike, which is intended for high speed riding, and a three-wheeled electrically assisted bicycle, which tends to maintain its independence even at low speeds. Therefore, for the former electrically assisted bicycle, for example, the threshold TH1 is set to 10 km/h, and for the latter electrically assisted bicycle, for example, the threshold TH1 is set to 5 km/h. However, this is only an example, and an appropriate value is set through an experiment or the like.

Then, if the vehicle speed is less than the predetermined threshold TH1, the control unit 3400 instructs to stop the motor drive and perform weak automatic braking, and the motor control unit 3500 stops the motor drive and weak automatic braking. is executed (step S23). Weak automatic braking means weaker than the degree of automatic braking in step S25. That is, when the vehicle speed is slow, the degree of automatic braking is weakened so as not to decelerate too much. Then, the process moves to step S13. For example, the amount of regenerative current is set to be small, or the regenerative braking torque is set to be small.

On the other hand, if the vehicle speed is equal to or higher than the predetermined threshold TH1, the control unit 3400 instructs to stop the motor drive and perform strong automatic braking, and the motor control unit 3500 stops the motor drive and strong automatic braking. is executed (step S25). Strong automatic braking means strong compared to the degree of automatic braking in step S23. That is, when the vehicle speed is high, the degree of automatic braking is strengthened so as to significantly decelerate the vehicle. Then, the process moves to step S13. For example, the amount of regenerative current is set to be large, or the torque of regenerative braking is set to be large.

An example of control in the present embodiment will be described using FIG. As schematically shown in the uppermost part of FIG. 7, an obstacle is placed in front of the power-assisted bicycle 1, and the power-assisted bicycle 1 is assumed to be traveling on flat ground toward the obstacle. . As shown in FIG. 7(a), the distance between the electrically power-assisted bicycle 1 and the obstacle gradually becomes shorter, and when the distance becomes 10 m or less, the possibility of collision is predicted to exceed a predetermined level (time t1). In this example, as shown in FIG. 7B, the predetermined pedal operation is not performed continuously. Therefore, the motor is not driven as shown in FIG. 7(c). Therefore, at time t1, when the possibility of collision is predicted to exceed a predetermined level, strong automatic braking is performed as shown in FIG. 7(d). Accordingly, as shown in FIG. 7(e), the vehicle speed suddenly decreases. However, when the vehicle speed reaches the threshold TH1=10 km/h (time t2), as shown in FIG. 7(d), the automatic braking changes from strong to weak. It does not impair the stability of running.

In this way, instead of simply performing automatic braking when the prescribed pedal operation is not performed, automatic braking is performed so as to maintain driving stability according to the vehicle speed, thereby improving safety. improvement in sexuality.

[Embodiment 3]
In the first and second embodiments, if the possibility of collision remains at or above a predetermined level, the user cannot obtain motor drive assistance. However, when the predetermined pedal operation is performed from the state in which the predetermined pedal operation is not performed, it means that the user has recognized a change in the situation, and the possibility of collision is equal to or higher than the predetermined level. Even if there is, it is preferable to perform assist by motor drive for speed maintenance. In addition, when the pedal rotation speeds up or the pedal input torque increases while a predetermined pedal operation is being performed, it also indicates that the user has recognized a change in the situation, indicating that a collision may occur. Even if the speed is at or above a predetermined level, it is preferable to perform assist by motor driving in order to maintain the speed.

The present embodiment is based on such a point of view, and operation contents according to the present embodiment will be explained using FIGS. 8 and 9. FIG. Note that steps S31 to S47 are executed at predetermined control cycles.

First, the collision prediction unit 3100 executes collision prediction based on the forward monitoring sensor input (Fig. 8: step S31). This step is the same as step S1 in FIG. When the collision prediction unit 3100 determines that the possibility of collision is less than the predetermined level (step S33: No route), the motor control unit 3500 executes normal control (step S49). In other words, the control unit 3400 does not instruct to execute or stop motor driving or to execute or stop automatic braking, and the motor control unit 3500 controls the motor so as to perform normal motor driving or regenerative braking. Further, the collision prediction unit 3100 sets off a first flag indicating that the possibility of collision is equal to or higher than a predetermined level and a second flag that is set when a predetermined pedal operation is not performed (step S51). ). The first flag and the second flag are initially turned off, and if they are already turned off in step S51, nothing will be done as a result. Then, the process moves to step S47.

On the other hand, when collision prediction unit 3100 predicts that the possibility of collision is equal to or higher than the predetermined level, collision prediction unit 3100 determines whether the first flag indicating that the possibility of collision is equal to or higher than the predetermined level is on. is determined (step S35). If the first flag is already on, the process proceeds to step S41. On the other hand, if the first flag is off, collision prediction section 3100 sets the first flag to on (step S37). Control unit 3400 is notified that the possibility of collision has reached or exceeded a predetermined level by turning on the first flag. Then, the control unit 3400 records in the memory the pedal rotation speed A and the pedal input torque B at the timing when the first flag is turned on (step S39). By recording the pedal rotation phase angle at this stage, the pedal rotation angle up to that control cycle can be obtained from the difference between the pedal rotation phase angle in the subsequent control cycle and the recorded pedal rotation phase angle.

Then, the control unit 3400 checks whether a predetermined pedal operation is performed (step S41). The predetermined pedal operation is, for example, a predetermined pedal operation that indicates the user's intention to continue running, and is the same as in the first embodiment. If a predetermined pedal operation is being performed (step S41: No route), the process proceeds via terminal A to the process of FIG.

On the other hand, if the predetermined pedal operation has not been performed (step S41: Yes route), the control unit 3400 turns on the second flag indicating that the predetermined pedal operation has not been performed (step S43). Then, the control unit 3400 instructs to stop driving the motor and execute automatic braking, and the motor control unit 3500 stops driving the motor and executes automatic braking (step S45). As in the first embodiment, when the user does not indicate the intention to continue running, not only the motor drive is stopped, but also automatic braking is performed to further decelerate the vehicle, thereby preventing a collision. reduce the chances.

Then, the motor control unit 3500 determines whether or not the user has instructed to end the processing by turning off the power (step S47). If the end of the process has not been instructed, the process returns to step S31. On the other hand, when the end of processing is instructed, the processing ends.

Next, the contents of operation after terminal A will be described using FIG. First, control unit 3400 determines whether or not the second flag is on (step S53). Here, if the second flag is ON, it indicates that there was a state in which the predetermined pedal operation was not performed in the past, and now the predetermined pedal operation is performed. Therefore, the user recognizes the situation change and starts pedaling. Therefore, if the second flag is on, the control unit 3400 instructs to stop automatic braking and restart motor driving, and the motor control unit 3500 stops automatic braking and restarts motor driving (step S55). . As a result, the user can continue running with assistance from the motor drive. Then, the process returns to step S47 via terminal B.

On the other hand, if the second flag is off, the control unit 3400 determines whether or not the condition for resuming motor driving is satisfied (step S59). Conditions for resuming motor driving in the present embodiment are, for example, the following conditions.

11) Current pedal rotation speed > Recorded pedal rotation speed A + 5 [rpm]
12) Current pedal input torque > recorded pedal input torque B + 5 [Nm]
13) Current pedal input torque>10Nm and pedal rotation angle>+45°
The numerical values are only examples, and appropriate numerical values are set through experiments and the like.

It may be determined that the conditions for resuming motor driving are met when all of these conditions are met, or it may be determined that the conditions for resuming motor driving are met when condition 1 or 2 is met. Conditions 11) and 12) are for detecting that the pedal rotation has become faster and that the pedal input torque has become stronger, based on the values recorded in step S39. Condition 13) is based on the condition that the pedal input torque is absolutely large, and the user's intention to increase speed is taken into account from the pedal rotation angle after the possibility of collision reaches a predetermined level or higher.

If the conditions for resuming motor driving are not satisfied, control unit 3400 instructs to stop motor driving and automatic braking, as in the first and second embodiments. Stop driving and automatic braking are executed (step S63). Also here, instead of stopping the motor drive, the driving force of the motor drive may be reduced in some cases. Then, the process returns to step S47 via terminal B.

On the other hand, if the conditions for resuming motor driving are satisfied, the control unit 3400 instructs to stop automatic braking and start driving the motor, and the motor control unit 3500 stops automatic braking and starts driving the motor (( step S61). Then, the process returns to step S47 via terminal B.

As described above, even when the possibility of a collision is equal to or higher than the predetermined level, if the user recognizes a change in the situation and the change is reflected in the pedal operation, the assist by the motor drive is restarted. , the control is more in line with the user's intention.

In the processing flows of FIGS. 8 and 9, when the same predetermined pedal operation is performed in a state in which the predetermined pedal operation is not performed, the motor is controlled to be driven. The motor may be driven when another second predetermined pedal operation is performed in a state in which no pedal operation is performed. The second predetermined pedal operation may include a condition regarding the pedal rotation angle.

Although the embodiment of the present invention has been described above, the present invention is not limited to this. For example, depending on the purpose, any technical feature in each embodiment described above may be deleted, or any technical feature described in other embodiments may be added. Also good. For example, the technical element of changing the strength of automatic braking according to the vehicle speed as in the second embodiment may be applied to the third embodiment.

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. As for the processing flow, the order of the steps may be changed, or a plurality of steps may be executed in parallel, as long as the content of the processing does not change.

Note that the condition 1) for a predetermined pedal operation is such that the pedal rotation speed is converted to the running speed [km/h] and compared with the vehicle speed. , and compared with the number of revolutions of the motor. Furthermore, it is also possible to convert the values into values in other units for comparison.

In the example described above, the number of motor rotations is converted into vehicle speed, but the vehicle speed can be calculated by providing a sensor that measures the vehicle speed or by accumulating the acceleration. The vehicle speed may be calculated by dividing by the time taken for . The traveling distance may be calculated from the trajectory obtained by measuring the position using, for example, GPS (Global Positioning System).

The above embodiments can be summarized as follows.

The control device for an electrically assisted vehicle according to the present embodiment includes (A) a collision prediction unit that predicts a collision based on an output from a forward monitoring sensor; is predicted, it is determined whether or not a predetermined pedal operation is being performed by the user. and a control unit that reduces the driving force of the drive or stops the motor drive.

In the case of an electrically assisted vehicle, even if the possibility of a collision is predicted to be at or above a predetermined level, the user's intention to travel is clearly indicated as long as the user performs a predetermined pedal operation. Prioritize the user's intentions. However, by reducing or stopping the assistance by the motor drive, the increase in vehicle speed is suppressed and the collision is avoided by the user.

In addition, the control section described above may perform control to decelerate the electrically assisted vehicle when a predetermined pedal operation is not performed. In the case of an electrically assisted vehicle, if the user does not indicate that the vehicle should travel, the vehicle is decelerated through regeneration or the like to avoid danger. However, other deceleration methods may be adopted in addition to regeneration.

Furthermore, when the predetermined pedal operation is not performed and the vehicle speed of the electrically assisted vehicle is less than the threshold value, the control unit described above controls the vehicle speed of the electrically assisted vehicle as compared with the case where the vehicle speed is equal to or greater than the threshold value. may be controlled to weaken the degree of deceleration. In the case of an electrically assisted vehicle, excessive deceleration is dangerous, so the degree of automatic braking is weakened at low speeds.

Further, the control unit described above decelerates the electrically assisted vehicle when it is detected that a predetermined pedal operation or a second predetermined pedal operation is being performed during control to decelerate the electrically assisted vehicle. It is also possible to stop the control to drive the motor and perform the control to drive the motor. The fact that the state in which the pedal is not being operated has changed to the state in which the pedal is being operated is because the intention of the user who has recognized the change in the situation indicates to continue running. It should be noted that the second predetermined pedal operation is an operation different from the predetermined pedal operation, and may include, for example, a condition regarding the pedal rotation angle.

Furthermore, the above-described control unit is controlled to reduce the driving force of the motor drive or to stop the motor drive when a predetermined pedal operation is performed, and the collision prediction unit detects that the possibility of a collision is at a predetermined level or higher. When it is detected that the pedal is operated to increase the vehicle speed of the electrically assisted vehicle, the motor may be driven. This is because, even when the pedal operation continues, it is preferable to restart the assist if the pedal operation increases the vehicle speed.

Note that the control unit described above determines whether or not the predetermined pedal operation is performed, and (a) the relationship between the vehicle speed of the electrically assisted vehicle and the traveling speed converted based on the pedal rotation satisfies a predetermined condition. Alternatively, the determination may be made based on at least one of (a) whether the pedal rotation speed is equal to or greater than the threshold value, and (c) whether or not the pedal input torque is equal to or greater than the threshold value.

Further, the control unit described above detects a predetermined pedal operation indicating that the vehicle speed of the electrically assisted vehicle is to be increased more than when the collision prediction unit predicts that the possibility of a collision is equal to or higher than a predetermined level. f) the current pedal rotation speed and the pedal input torque when the collision prediction unit predicts that the possibility of a collision is equal to or higher than a predetermined level; ii) at least one of the current pedal input torque and the current pedal input torque has increased by a predetermined amount or more; You may make it determine by .

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

Claims

a collision prediction unit that predicts a collision based on the output from the forward monitoring sensor;
When the collision prediction unit predicts that the possibility of collision is equal to or higher than a predetermined level, it determines whether or not a predetermined pedal operation is performed by the user, and if the predetermined pedal operation is performed, a control unit that stops control for decelerating the electrically assisted vehicle and reduces the driving force of the motor drive or stops the motor drive;
A control device for an electrically assisted vehicle.
The control unit
The control device according to claim 1, wherein when the predetermined pedal operation is not performed, the electrically assisted vehicle is controlled to decelerate.
The control unit
When the vehicle speed of the electrically assisted vehicle is less than the threshold value when the predetermined pedal operation is not performed, the degree of deceleration of the electrically assisted vehicle is greater than when the vehicle speed is equal to or greater than the threshold value. 3. The control device according to claim 2, wherein control is performed so as to weaken.
The control unit
When it is detected that the predetermined pedal operation or the second predetermined pedal operation is being performed during the control to decelerate the electric assist vehicle, the control for decelerating the electric assist vehicle is stopped and the 4. The control device according to claim 2 or 3, which controls to drive the motor.
The control unit
When the collision prediction unit predicts that the possibility of a collision is equal to or higher than a predetermined level during control for reducing the driving force of the motor drive or stopping the motor drive when the predetermined pedal operation is performed 2. The control device according to claim 1, further comprising: performing control for executing the motor drive when detecting a pedal operation indicating that the vehicle speed of the electrically assisted vehicle is to be increased.
The control unit
Whether the predetermined pedal operation is performed, whether the relationship between the vehicle speed of the electrically assisted vehicle and the running speed converted based on the pedal rotation satisfies a predetermined condition, or whether the pedal rotation speed is equal to or greater than a threshold and whether or not the pedal input torque is equal to or greater than the threshold.
The control unit
whether or not a predetermined pedal operation indicating that the vehicle speed of the electrically assisted vehicle is to be increased from when the collision prediction unit predicts that the possibility of a collision is equal to or higher than a predetermined level is detected;
The current pedal rotation speed and the current pedal input torque are calculated based on at least one of the pedal rotation speed and the pedal input torque when the collision prediction unit predicts that the possibility of a collision is equal to or higher than a predetermined level. increased by a predetermined amount or more, and predetermined conditions regarding the pedal input torque and the pedal rotation angle are satisfied. controller.
An electrically assisted vehicle having the control device according to claim 1.