Vehicle control device, vehicle control method and computer program for vehicle control

Abstract

To provide a vehicle control device that can reduce discomfort of a driver caused by executing regenerative control.SOLUTION: A vehicle control device comprises a control part 33 that when a vehicle 10 is decelerated, controls a motor 12 so that amounts of regenerative electric power that is obtained when the vehicle is decelerated by the motor 12 loaded on the vehicle 10 at the time when an acceleration / deceleration control mode in which acceleration and deceleration of the vehicle 10 is controlled in accordance with an inter-vehicle distance between a preceding vehicle and the vehicle 10 is applied are set to be smaller by predetermined adjustment amounts than amounts of regenerative electric power at the time when the acceleration / deceleration control mode is not applied.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a vehicle control device, a vehicle control method, and a computer program for vehicle control. [Background technology]

[0002] In order to avoid the vehicle becoming unable to drive due to a decrease in the state of charge while minimizing changes in vehicle behavior, a technology has been proposed that switches the control mode of the electric motor so that the amount of regenerative power generated by the electric motor increases when it is determined that the state of charge of the storage battery that powers the electric motor that drives the vehicle has decreased (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-193357 Summary of the Invention [Problem to be solved by the invention]

[0004] Increasing the regenerative torque to increase the amount of regenerative power also increases the noise (hereinafter referred to as regenerative noise) generated by the motor when obtaining regenerative power during deceleration of the vehicle. In particular, when automatic deceleration control is performed on the vehicle, such as when driving assistance control is being executed on the vehicle, the driver is less likely to pay attention to driving operations and is therefore more likely to feel annoyed by the regenerative noise. Furthermore, if regenerative control is continued so that regenerative torque is generated until the vehicle is about to come to a stop in order to increase the amount of regenerative power obtained, the fluctuation in acceleration just before the vehicle comes to a stop increases relatively, resulting in a greater shock when the vehicle comes to a stop.

[0005] Therefore, an object of the present invention is to provide a vehicle control device that can reduce the discomfort felt by the driver when regenerative control is performed. [Means for solving the problem]

[0006] A vehicle control device according to one embodiment has a control unit that controls a motor when the vehicle decelerates so that the amount of regenerative power obtained by the motor mounted on the vehicle when an acceleration / deceleration control mode is applied, which controls the acceleration / deceleration of the vehicle according to the distance between the vehicle and a preceding vehicle, is reduced by a predetermined adjustment amount compared to the amount of regenerative power when the acceleration / deceleration control mode is not applied.

[0007] In one embodiment, the control unit reduces the amount of adjustment as the remaining battery charge of the vehicle decreases.

[0008] In one embodiment, the control unit decreases the amount of adjustment as the noise around the vehicle or inside the vehicle cabin increases.

[0009] A vehicle control method according to another embodiment includes controlling a motor when the vehicle decelerates so that the amount of regenerative power obtained by the motor mounted on the vehicle when an acceleration / deceleration control mode is applied, which controls the acceleration / deceleration of the vehicle in accordance with the distance between the vehicle and a preceding vehicle, is reduced by a predetermined adjustment amount compared to the amount of regenerative power obtained when the acceleration / deceleration control mode is not applied.

[0010] In yet another embodiment, a computer program for vehicle control includes instructions to cause a processor mounted on the vehicle to control the motor when the vehicle decelerates, so that when an acceleration / deceleration control mode is applied, which controls the acceleration / deceleration of the vehicle in accordance with the distance between the vehicle and a preceding vehicle, the amount of regenerative power obtained by the motor mounted on the vehicle during deceleration is reduced by a predetermined adjustment amount compared to the amount of regenerative power when the acceleration / deceleration control mode is not applied. [Effects of the Invention]

[0011] The vehicle control device according to the present disclosure has the effect of reducing the discomfort felt by the driver when regenerative control is performed. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic configuration diagram of a vehicle in which a vehicle control device is implemented; [Figure 2] FIG. 2 is a functional block diagram of a processor of an electronic control unit related to vehicle control processing. [Figure 3] FIG. 2 is a diagram illustrating an outline of adjustment of regenerative torque according to the present embodiment. [Figure 4] 4 is an operational flowchart of a vehicle control process according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] A vehicle control device, a vehicle control method, and a vehicle control computer program executed on the vehicle control device will be described below with reference to the drawings. This vehicle control device controls the vehicle so that the amount of regenerative power generated by the vehicle's motor during deceleration when the vehicle's battery remaining charge is equal to or less than a predetermined threshold is greater than the amount of regenerative power when the battery remaining charge is greater than the threshold. Furthermore, this vehicle control device reduces the increase in regenerative power when an acceleration / deceleration control mode that automatically controls the vehicle's acceleration / deceleration in accordance with the distance between the vehicle and a preceding vehicle is applied by a predetermined adjustment amount compared to the increase in regenerative power when the acceleration / deceleration control mode is not applied, thereby alleviating driver discomfort associated with the execution of regenerative control.

[0014] 1 is a schematic diagram of a vehicle in which a vehicle control device is implemented. In this embodiment, the vehicle 10 is a battery electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle, and a powertrain 11 of the vehicle 10 includes a motor 12 as a driving power source or a generator for recovering regenerative energy. The vehicle 10 also has a battery 13 for supplying power to various parts of the vehicle 10, and during deceleration, the motor 12 operates as a generator to recover regenerative energy and charge the battery 13. The vehicle 10 also has an external sensor 14 and an electronic control unit (ECU) 15.

[0015] The exterior sensor 14 is a sensor that generates an exterior sensor signal that indicates the situation around the vehicle 10, and is, for example, a camera that is installed so as to be able to capture images of the area around the vehicle 10, or a distance measurement sensor such as a LiDAR or a radar. The vehicle 10 may be provided with a plurality of exterior sensors 14 with different detectable ranges or types. Each time the exterior sensor 14 generates an exterior sensor signal, the exterior sensor 14 outputs the generated exterior sensor signal to the ECU 15.

[0016] The ECU 15 is an example of a vehicle control device and is capable of executing an acceleration / deceleration control mode that automatically controls the acceleration / deceleration of the vehicle 10 according to the distance between the preceding vehicle and the vehicle 10. The acceleration / deceleration control may be executed as one function of driving assistance control or one function of automatic driving control. In other words, the driving assistance mode and the automatic driving mode are examples of acceleration / deceleration control modes. The ECU 15 also executes regenerative control by the motor 12 when the vehicle 10 decelerates.

[0017] The ECU 15 has a communication interface 21, a memory 22, and a processor 23. The communication interface 21, the memory 22, and the processor 23 may be configured as separate circuits, or may be integrated into a single integrated circuit.

[0018] The communication interface 21 has an interface circuit for connecting the ECU 15 to other devices. The communication interface 21 passes signals from the external sensors 14 to the processor 23. Furthermore, the communication interface 21 outputs control signals for the powertrain 11 received from the processor 23 to the powertrain 11.

[0019] The memory 22 is an example of a storage unit and includes a volatile semiconductor memory and a non-volatile semiconductor memory. The memory 22 stores various data used in the vehicle control process executed by the processor 23 or generated during the vehicle control process.

[0020] The processor 23 includes one or more central processing units (CPUs) and their peripheral circuits. The processor 23 may further include other arithmetic circuits such as a logic unit, a numerical calculation unit, or a graphics processing unit. The processor 23 executes vehicle control processing for the vehicle 10.

[0021] 2 is a functional block diagram of processor 23 related to vehicle control processing. Processor 23 has a mode setting unit 31, a determination unit 32, and a control unit 33. Each of these units in processor 23 is a functional module realized by, for example, a computer program running on processor 23. Alternatively, each of these units may be a dedicated arithmetic circuit provided in processor 23.

[0022] The mode setting unit 31 sets the driving mode to be applied to the vehicle 10 to a mode specified by an operation signal from an operating device (not shown) provided in the cabin of the vehicle 10. That is, when the operation signal indicates that a driving mode including acceleration / deceleration control (driving assistance mode or automated driving mode) is to be set, the mode setting unit 31 applies the driving mode to the vehicle 10. When the operation signal indicates that a manual driving mode indicating manual driving by the driver is to be set, the mode setting unit 31 applies the manual driving mode to the vehicle 10. Then, every time the driving mode to be applied to the vehicle 10 is changed via operation of the operating device, the mode setting unit 31 notifies the control unit 33 of the changed driving mode.

[0023] The determination unit 32 acquires a signal indicating the remaining capacity, such as a signal indicating the state of charge (SOC), from the battery 13 at predetermined intervals (e.g., one to several seconds), and compares the remaining battery capacity indicated by the signal with a predetermined threshold (e.g., 30% to 60% of a fully charged state).The determination unit 32 then determines at each predetermined interval whether the remaining battery capacity is equal to or less than the predetermined threshold, and notifies the control unit 33 of the determination result.

[0024] The control unit 33 controls the running of the vehicle 10 in accordance with the applied driving mode. Furthermore, the control unit 33 controls the powertrain 11 when the vehicle 10 decelerates, particularly performs regenerative control on the motor 12, in accordance with the determination result by the determination unit 32 and the applied driving mode.

[0025] When the manual driving mode is applied (i.e., when the acceleration / deceleration control mode is not applied), the control unit 33 refers to a map that shows the relationship between the accelerator opening of the accelerator device (not shown), the rotation speed of the engine or motor 12 included in the powertrain 11, and the target torque. The control unit 33 then sets the target torque according to the accelerator opening corresponding to the driver's accelerator pedal depression amount in accordance with the map, and generates a control signal for the powertrain 11 according to the set target torque. The control unit 33 then outputs the generated control signal to the powertrain 11. In this case, the control unit 33 controls the powertrain 11 according to feedback control such as PID control so that the torque actually output approaches the target torque. Furthermore, when the driver depresses the brake pedal, the control unit 33 sets a target torque for decelerating the vehicle 10 according to the driver's brake pedal depression amount, and controls the powertrain 11, including the brake device (not shown) and the motor 12, according to the set target torque.

[0026] In particular, when the vehicle 10 decelerates, the target torque is determined to be the sum of the brake braking torque for decelerating the vehicle 10 by the brake device and the regenerative torque by the motor 12. Therefore, the control unit 33 determines the brake braking torque and the regenerative torque by referring to a map showing the relationship between the vehicle speed of the vehicle 10 measured by a speed sensor (not shown) mounted on the vehicle 10, the depression amount of the brake pedal, the rotation amount of the motor 12, the rotation amount of the engine (if the powertrain 11 includes an engine), the brake braking torque, and the regenerative torque. Such a map is stored in advance in the memory 22.

[0027] If the regenerative torque is not zero, the motor 12 generates regenerative power corresponding to the regenerative torque. Therefore, the amount of regenerative power is calculated as the sum of the regenerative power during the period when the regenerative torque is generated (i.e., the period during which the regenerative torque is not zero). Furthermore, when the control unit 33 receives a determination result from the determination unit 32 that the remaining battery charge is equal to or less than a predetermined threshold, the control unit 33 increases the regenerative torque so that the amount of regenerative power obtained is greater than when the remaining battery charge is greater than the threshold. In this case, the control unit 33 may increase the regenerative torque itself at each speed, or may expand the speed range in which the regenerative torque is generated to a lower speed range. Alternatively, the control unit 33 may increase the amount of regenerative power obtained by both increasing the regenerative torque itself and expanding the speed range in which the regenerative torque is generated. The control unit 33 then corrects the target torque so that it increases by the amount of increase in the regenerative torque. Therefore, when the remaining battery charge is equal to or less than a threshold, the control unit 33 determines the amount of increase in the regenerative torque at each speed by referring to a table in which the amount of increase in the regenerative torque at each speed is set. Such a table is stored in advance in the memory 22.

[0028] Furthermore, while the driving assistance mode or the autonomous driving mode is applied, the control unit 33 controls the powertrain 11 and the brake device so that the vehicle 10 travels at a target vehicle speed. Furthermore, the control unit 33 controls the powertrain 11 and the brake device so that the inter-vehicle distance between the vehicle 10 and a preceding vehicle traveling ahead of the vehicle 10 in the vehicle's own lane is maintained at a predetermined distance or greater. The target vehicle speed is set via an in-vehicle operating device. Alternatively, the control unit 33 may identify the road section on which the vehicle 10 is traveling and the legal speed of the road section based on map information indicating the legal speed of each road section and the current position of the vehicle 10, and set the target vehicle speed to the identified legal speed. Such map information is pre-stored in the memory 22 or an on-board storage device (not shown) for storing map information. The current position of the vehicle 10 may be determined by a satellite positioning system receiver (not shown) installed in the vehicle 10.

[0029] To detect a leading vehicle, the control unit 33 detects other vehicles traveling around the vehicle 10. To this end, the control unit 33 detects other vehicles by inputting exterior sensor signals, obtained by the exterior sensors 14 and representing the conditions of the area around the vehicle 10, into a classifier that has been trained in advance to detect other vehicles traveling around the vehicle 10. This classifier can be a classifier based on a deep neural network (DNN) having a convolutional neural network (CNN) type architecture or an attention mechanism.

[0030] When the external sensor 14 is a camera installed to capture images of the surroundings of the vehicle 10 and the external sensor signal is an image, the classifier detects an object region representing another vehicle detected in the image. Furthermore, the control unit 33 detects lane lines by inputting the image generated by the camera to a classifier for lane line detection that has been trained in advance to detect lane lines. The classifier for lane line detection may be a DNN for semantic segmentation, such as a U-net. Alternatively, the classifier for detecting other vehicles may be trained in advance to detect lane lines as well. The control unit 33 then determines the region in the image between the two detected lane lines closest to the vehicle 10 as the current lane region representing the current lane. The control unit 33 may identify, among the detected other vehicles, the vehicle whose bottom edge of the object region in the image is included in the current lane region and which is closest to the bottom of the image as the leading vehicle. Alternatively, the control unit 33 may identify, as the preceding vehicle, one of the detected other vehicles that is located in a direction corresponding to the traveling direction of the vehicle 10. Then, the control unit 33 estimates the distance from the vehicle 10 to the preceding vehicle.

[0031] The position of the bottom edge of the object area representing the leading vehicle is assumed to represent the position where the leading vehicle touches the road surface. Furthermore, the position on the image corresponds one-to-one with the direction as seen from the camera that generated the image. Therefore, the control unit 33 can estimate the distance and direction from the camera to the leading vehicle by referring to the position of the bottom edge of the object area representing the leading vehicle on the image and parameters such as the camera installation height, shooting direction, and angle of view.

[0032] Furthermore, if the external sensor 14 is a distance measurement sensor, the control unit 33 identifies, among the other detected vehicles, a vehicle detected in a direction corresponding to the traveling direction of the vehicle 10 as the preceding vehicle. The control unit 33 then estimates the distance measured in the direction in which the detected preceding vehicle appears as the distance between the vehicle 10 and the preceding vehicle.

[0033] If the estimated distance to the preceding vehicle (hereinafter sometimes simply referred to as the inter-vehicle distance) is less than a predetermined distance, the control unit 33 sets a target acceleration / deceleration rate to decelerate the vehicle 10. In this case, the control unit 33 sets the target acceleration / deceleration rate so that the deceleration rate increases as the inter-vehicle distance to the preceding vehicle decreases or as the relative speed of the vehicle 10 relative to the preceding vehicle increases. On the other hand, if the estimated inter-vehicle distance to the preceding vehicle is equal to or greater than the predetermined distance, the control unit 33 sets the target acceleration / deceleration rate so that the speed of the vehicle 10 approaches the target vehicle speed. However, if the speed of the preceding vehicle is slower than the target vehicle speed, the control unit 33 sets the target acceleration / deceleration rate so that the inter-vehicle distance becomes the predetermined distance and the relative speed between the vehicle 10 and the preceding vehicle becomes zero. To this end, the control unit 33 sets the target acceleration / deceleration rate based on, for example, a relational expression between the inter-vehicle distance, the relative speed, and the target acceleration / deceleration rate. The control unit 33 then determines a target torque corresponding to the set target acceleration / deceleration, and outputs a control signal corresponding to the target torque to the power train 11 including the motor 12 and the brake device.

[0034] In this case, too, when the target acceleration / deceleration indicates deceleration of the vehicle 10, the control unit 33 sets the target torque to be the sum of the braking torque and the regenerative torque. The control unit 33 determines the braking torque and the regenerative torque by referring to a map showing the relationship between the target acceleration / deceleration, the vehicle speed of the vehicle 10 measured by the speed sensor, the rotation amount of the motor 12, the rotation amount of the engine (if the powertrain 11 includes an engine), the braking torque, and the regenerative torque. Furthermore, when the control unit 33 receives a determination result from the determination unit 32 that the remaining battery charge is equal to or less than a predetermined threshold, the control unit 33 increases the regenerative torque so that the amount of regenerative power obtained is increased compared to when the remaining battery charge is greater than the threshold. The control unit 33 then corrects the target torque so that it increases by the amount of increase in the regenerative torque. Note that in this case, too, the control unit 33 may increase the regenerative torque itself, or may expand the speed range at which the regenerative torque is generated to a lower speed range. Alternatively, the control unit 33 may increase the amount of regenerative power obtained by both increasing the regenerative torque itself and expanding the speed range in which the regenerative torque is generated.

[0035] However, the control unit 33 sets the increase in the amount of regenerative power when the driving assistance mode or the automatic driving mode is applied so that the increase in the amount of regenerative power is smaller by a predetermined adjustment amount than the increase in the amount of regenerative power when the manual driving mode is applied. In this case, the control unit 33 reduces the increase in regenerative torque when the driving assistance mode or the automatic driving mode is applied compared to the increase in regenerative torque when the manual driving mode is applied. Alternatively, the control unit 33 may narrow the speed range in which regenerative torque is generated when the driving assistance mode or the automatic driving mode is applied compared to the speed range in which regenerative torque is generated when the manual driving mode is applied. Alternatively, the control unit 33 may reduce the increase in regenerative torque when the driving assistance mode or the automatic driving mode is applied and narrow the speed range in which regenerative torque is generated compared to when the manual driving mode is applied. The control unit 33 may determine the increase in regenerative torque at each speed by referring to a table in which the increase in regenerative torque at each speed is set so that the amount of regenerative power obtained is reduced by a predetermined adjustment amount. Such a table is pre-stored in the memory 22. As a result, when the driving assistance mode or the automatic driving mode is applied, in which the driver is more likely to pay attention to the regenerative noise, the regenerative noise is suppressed compared to when the manual driving mode is applied. Furthermore, since the change in the acceleration in the longitudinal direction of the vehicle 10 when the vehicle 10 stops is reduced, the shock felt by the driver is reduced.

[0036] Even when the driving assistance mode or the autonomous driving mode is applied, if the driver depresses the accelerator pedal or the brake pedal by a predetermined amount or more, the control unit 33 may control the powertrain 11 and the brake device in accordance with the driving operation by the driver. In this case, the control unit 33 may determine the regenerative torque and the target torque during deceleration in the same way as when the manual driving mode is applied.

[0037] FIG. 3 is a diagram illustrating an overview of regenerative torque adjustment according to this embodiment. In FIG. 3, the horizontal axis represents elapsed time. In the topmost time chart, the vertical axis represents speed, and graph 300 represents the change in vehicle speed of vehicle 10 over time. In the second-highest time chart, the vertical axis represents torque. A negative torque value indicates that the torque decelerates vehicle 10. Graph 310 represents the change in regenerative torque over time when the remaining charge of battery 13 is greater than a threshold. Graph 311 represents the change in regenerative torque over time when the remaining charge of battery 13 is equal to or less than a threshold and the manual driving mode is applied. Graph 312 represents the change in regenerative torque over time when the remaining charge of battery 13 is equal to or less than a threshold and a driving mode including acceleration / deceleration control (driving assistance mode or autonomous driving mode) is applied. Finally, in the bottommost time chart, the vertical axis represents acceleration. Graph 321 represents the change in longitudinal acceleration of vehicle 10 over time when the remaining charge of battery 13 is equal to or less than a threshold and the manual driving mode is applied. Furthermore, graph 322 represents the change over time in the longitudinal acceleration of vehicle 10 when the remaining charge of battery 13 is equal to or less than a threshold and a driving mode including acceleration / deceleration control is applied.

[0038] As shown in graphs 310 to 312, when the remaining charge of the battery 13 is equal to or less than the threshold, there is a period during which the absolute value of the regenerative torque is larger than when the remaining charge of the battery 13 is greater than the threshold, and thus the amount of regenerative power obtained also increases. However, the increase in the absolute value of the regenerative torque when a driving mode including acceleration / deceleration control is applied is smaller than the increase in the absolute value of the regenerative torque when the manual driving mode is applied. Furthermore, the speed range in which regenerative torque is generated when a driving mode including acceleration / deceleration control is applied is narrower than the speed range in which regenerative torque is generated when the manual driving mode is applied. From this, as shown in graphs 321 and 322, it can be seen that when a driving mode including acceleration / deceleration control is applied, the absolute value of the longitudinal acceleration is smaller than when the manual driving mode is applied, and in particular, there is no fluctuation in acceleration before and after stopping. From this, it can be seen that when a driving mode including acceleration / deceleration control is applied, the increase in the amount of regenerative power obtained is smaller than when the manual driving mode is applied, but regenerative noise and shock during stopping are suppressed.

[0039] FIG. 4 is an operational flowchart of the vehicle control process according to this embodiment.

[0040] The determination unit 32 determines whether the remaining charge of the battery 13 is equal to or less than a predetermined threshold Th (step S101). If the remaining charge of the battery 13 is greater than the predetermined threshold Th (step S101-No), the control unit 33 sets a target torque including a predetermined regenerative torque based on the accelerator opening, the brake depression amount, the distance to the preceding vehicle, etc. (step S102).

[0041] If the remaining charge of the battery 13 is equal to or less than the predetermined threshold Th (step S101-Yes), the control unit 33 determines whether or not a driving mode including acceleration / deceleration control is applied (step S103). If a driving mode including acceleration / deceleration control is not applied (step S103-No), the control unit 33 sets the target torque by increasing the regenerative torque so that the amount of regenerative power obtained during deceleration is increased compared to when the remaining charge of the battery 13 is greater than the predetermined threshold Th (step S104).

[0042] On the other hand, if an operating mode including acceleration / deceleration control is set (step S103-Yes), the control unit 33 sets the target torque by increasing the regenerative torque so that the amount of regenerative power obtained during deceleration increases by an amount obtained by subtracting an adjustment amount from a predetermined increment compared to when the remaining charge of the battery 13 is greater than a predetermined threshold Th (step S105).

[0043] After step S102, S104 or S105, the control unit 33 controls the power train 11 and the brake device in accordance with the set target torque (step S106).

[0044] As described above, this vehicle control device controls the vehicle so that the amount of regenerative power during deceleration when the vehicle's battery remaining charge is equal to or less than a predetermined threshold is increased compared to the amount of regenerative power when the battery remaining charge is greater than the threshold. Furthermore, this vehicle control device reduces the increase in the amount of regenerative power when the acceleration / deceleration control mode is applied by a predetermined adjustment amount compared to the increase in the amount of regenerative power when the acceleration / deceleration control mode is not set. This reduces regenerative noise during regenerative control and shock when stopping the vehicle when the acceleration / deceleration control mode is applied, when the driver's attention is likely to be directed to things other than driving. Therefore, this vehicle control device can reduce the driver's discomfort caused by the execution of regenerative control.

[0045] According to a modified example, the control unit 33 may reduce the adjustment amount of the increase in the amount of regenerative power, which is the difference between when the acceleration / deceleration control mode is set and when it is not set, as the remaining charge of the battery 13 decreases. In this case, by referencing a table that represents the relationship between the remaining charge of the battery and the regenerative torque for each speed when the acceleration / deceleration control mode is applied, the control unit 33 determines the regenerative torque for each speed so that the amount of regenerative power obtained is reduced by the adjustment amount. Note that such a table may be stored in the memory 22 in advance. As a result, even when the acceleration / deceleration control mode is set, the amount of regenerative power obtained during deceleration increases as the remaining charge of the battery 13 decreases. Therefore, this vehicle control device can balance the reduction of driver discomfort with the amount of regenerative power obtained.

[0046] According to another modification, the control unit 33 may reduce the adjustment amount of the increase in the amount of regenerative power as the noise level increases around the vehicle 10 or inside the vehicle cabin. In this case, the control unit 33 may determine the regenerative torque for each speed by referencing a table that represents the relationship between the level of noise and the regenerative torque for each speed when the acceleration / deceleration control mode is set, so that the amount of regenerative power obtained is reduced by the adjustment amount. Note that such a table may be stored in the memory 22 in advance. The louder the noise around the vehicle 10 or inside the vehicle cabin, the less likely the driver is to notice the regenerative noise. Therefore, in an environment where regenerative noise is difficult to notice, the control unit 33 prioritizes increasing the amount of regenerative power obtained during deceleration over reducing regenerative noise, thereby achieving a balance between reducing the discomfort the driver experiences due to regenerative noise and increasing the amount of regenerative power obtained.

[0047] The control unit 33 may estimate the level of noise around the vehicle 10 based on the actual vehicle speed of the vehicle 10 or the unevenness of the road surface on which the vehicle 10 is traveling. Generally, the faster the actual vehicle speed, the louder the noise generated during traveling. Therefore, the control unit 33 determines that the faster the vehicle speed of the vehicle 10 measured by a vehicle speed sensor (not shown) mounted on the vehicle 10, the louder the noise around the vehicle 10, and decreases the adjustment amount. In this case, a table showing the relationship between the vehicle speed of the vehicle 10 and the adjustment amount is stored in advance in the memory 22. The control unit 33 may then determine the adjustment amount by referring to the table.

[0048] Furthermore, the greater the degree of road surface roughness, the greater the noise around the vehicle 10 while the vehicle 10 is traveling. The greater the degree of road surface roughness, the greater the short-term fluctuation in the wheel speed measured together with the vehicle speed by a vehicle speed sensor. Furthermore, the greater the degree of road surface roughness, the greater the fluctuation range of the acceleration of the vehicle 10 measured by an acceleration sensor (not shown) mounted on the vehicle 10. Therefore, the control unit 33 performs an FFT on the wheel speed measurements taken over a recent predetermined period to calculate each frequency component of the wheel speed fluctuation. The control unit 33 then reduces the adjustment amount as the wheel speed fluctuation component at a predetermined frequency (e.g., several hundred Hz) increases. Alternatively, the control unit 33 may reduce the adjustment amount as the sum of the absolute values ​​of the acceleration fluctuation amounts between individual sampling points included in the most recent predetermined period increases. In this case, the control unit 33 may determine the adjustment amount by referring to a table previously stored in the memory 22 that indicates the relationship between the adjustment amount and the wheel speed fluctuation component or the absolute value sum of the acceleration fluctuation amount at a predetermined frequency.

[0049] It is also assumed that the more audio output devices mounted on the vehicle 10 are turned on and the higher the set volume of the speakers installed in the vehicle cabin, the louder the noise inside the vehicle cabin will be. Therefore, the control unit 33 may decrease the adjustment amount as the more audio output devices are turned on and the higher the set volume of the speakers installed in the vehicle cabin. In this case, the control unit 33 may determine the adjustment amount by referring to a table that is stored in advance in the memory 22 and indicates the relationship between the set volume of the speakers and the adjustment amount.

[0050] The control unit 33 may also set the regenerative torque and the target torque so that the amount of regenerative power obtained when the vehicle 10 decelerates increases as the remaining battery charge decreases. In this case, a table showing the increment of regenerative torque at each speed when the manual driving mode is applied and the increment of regenerative torque at each speed when the acceleration / deceleration control mode is applied may be stored in advance in the memory 22 for each remaining battery charge. The control unit 33 may then determine the increment of regenerative torque when the manual driving mode or the acceleration / deceleration control mode is applied by selecting a table according to the remaining battery charge. In this case, as in the above embodiment, the adjustment amount of the increment of regenerative torque at each speed is set so that the amount of regenerative power obtained when the acceleration / deceleration control mode is applied is smaller than when the manual driving mode is applied. Therefore, regenerative noise and shock when stopping when the acceleration / deceleration control mode is applied are suppressed, thereby reducing discomfort felt by the driver. Note that in this modification, the determination unit 32 may be omitted. Also, as in the above-described modified example, the adjustment amount may be set to decrease as the remaining battery charge decreases or as the noise around the vehicle 10 or inside the vehicle compartment increases.

[0051] Furthermore, the control unit 33 may set the regenerative torque and target torque when the vehicle 10 decelerates, regardless of the remaining battery charge. In this case, in the map referred to for determining the regenerative torque when the acceleration / deceleration control mode is applied in the above embodiment, the regenerative torque at each speed may be set so that the regenerative torque is reduced by a predetermined adjustment amount compared to when the manual driving mode is applied. In this modified example, the determination unit 32 may also be omitted. As in the above modified example, the adjustment amount may be set to decrease as the remaining battery charge decreases or as noise around the vehicle 10 or inside the vehicle cabin increases.

[0052] A computer program that realizes the functions of the processor 23 of the ECU 13 according to the above embodiment or each of the variations may be provided in a form recorded on a computer-readable portable recording medium such as a semiconductor memory, a magnetic recording medium or an optical recording medium. [Explanation of symbols]

[0053] 10 vehicle, 11 power train, 12 motor, 13 battery, 14 outside vehicle sensor, 15 electronic control unit (ECU, vehicle control unit), 21 communication interface, 22 memory, 23 processor, 31 mode setting unit, 32 determination unit, 33 control unit

Claims

1. a control unit that controls the motor when the vehicle decelerates, when an acceleration / deceleration control mode that controls acceleration / deceleration of the vehicle in accordance with the distance between the vehicle and a preceding vehicle is applied, so that the amount of regenerative power obtained by the motor during deceleration is smaller by a predetermined adjustment amount than the amount of regenerative power when the acceleration / deceleration control mode is not applied; A vehicle control device having the above.

2. The vehicle control device according to claim 1 , wherein the control unit reduces the adjustment amount as the remaining charge of the battery of the vehicle decreases.

3. The vehicle control device according to claim 1 , wherein the control unit reduces the adjustment amount as the noise around the vehicle or inside the vehicle becomes louder.

4. When an acceleration / deceleration control mode is applied, which controls acceleration / deceleration of the vehicle in accordance with the distance between the vehicle and a preceding vehicle, the motor mounted on the vehicle is controlled when the vehicle decelerates so that the amount of regenerative power obtained during deceleration by the motor is reduced by a predetermined adjustment amount compared to the amount of regenerative power when the acceleration / deceleration control mode is not applied. A vehicle control method comprising:

5. When an acceleration / deceleration control mode is applied, which controls acceleration / deceleration of the vehicle in accordance with the distance between the vehicle and a preceding vehicle, the motor mounted on the vehicle is controlled when the vehicle decelerates so that the amount of regenerative power obtained during deceleration by the motor is reduced by a predetermined adjustment amount compared to the amount of regenerative power when the acceleration / deceleration control mode is not applied. A computer program for vehicle control that causes a processor mounted on the vehicle to execute the above.

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