Vehicle control device

Abstract

To provide a control device of a vehicle that can suppress rapid deceleration.SOLUTION: A control device of a vehicle according to the present invention is mounted with a driving motor that performs regenerative braking when a driver performs operation of releasing an accelerator pedal, and comprises a torque control part that, when following travel that the vehicle follows a precedent vehicle travelling in front of the vehicle is finished, limits variations of a driving torque value for driving driving wheels of the vehicle, until the driving torque value reaches a driver torque value indicating a torque value required by the driver from an ACC torque value indicating a torque value required in the following travel.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a vehicle control device. [Background technology]

[0002] Conventionally, some vehicles are equipped with a hybrid system that runs on both an engine and a motor. When a vehicle equipped with a hybrid system decelerates, it uses the rotation of the tires to rotate a generator motor, and uses the torque that rotates this generator motor for braking, thereby slowing down the vehicle by using regenerative braking. In addition, some vehicles are driven by an adaptive cruise control (ACC) function that allows the vehicle to follow a preceding vehicle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-175943 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-098307 Summary of the Invention [Problem to be solved by the invention]

[0004] However, if the ACC function is turned off while the vehicle is moving, the vehicle will no longer accelerate due to the ACC function, and the vehicle will suddenly decelerate due to regenerative braking. At this time, passengers may feel uncomfortable due to the sudden deceleration caused by regenerative braking.

[0005] The present invention has been made in view of the above, and has an object to provide a vehicle control device that can suppress sudden deceleration. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, a vehicle control device according to the present invention is a vehicle control device equipped with a drive motor that performs regenerative braking when an accelerator pedal is released by a driver, and includes a torque control unit that, when the following-traveling of the vehicle following a preceding vehicle traveling ahead of the vehicle ends, limits the amount of change in a drive torque value that drives drive wheels of the vehicle from an ACC torque value that indicates a torque value requested during the following-traveling to a driver torque value that indicates a torque value requested by the driver. The torque control unit divides the period into a first section, which is the period until the driving torque value reaches a following driving lower limit torque value, which indicates the lower limit of the driving torque value in the following driving, a second section, which is the period from the following driving lower limit torque value to a driver torque value, which indicates the driving torque value requested by the driver, and a standby section, which is set between the first section and the second section and is a period during which the driving torque value is not changed, and limits the amount of change based on a set value set for each section.

[0007] According to this configuration, the vehicle control device limits the amount of change in the drive torque value when ACC ends, thereby making it possible to suppress abrupt deceleration.

[0008] In addition, in the vehicle control device of the present invention, the torque control unit divides the period during which the amount of change in the driving torque value is limited into multiple sections, and limits the amount of change based on a set value set for each section.

[0009] According to this configuration, the vehicle control device divides the vehicle into a plurality of sections and limits the amount of change for each section, so that it is possible to control the amount of change in the drive torque value according to the section.

[0010] In addition, in the vehicle control device of the present invention, the torque control unit divides the vehicle into a first section until the driving torque value reaches a following driving lower limit torque value that indicates the lower limit of the driving torque value in following driving, and a second section from the following driving lower limit torque value to a driver torque value that indicates the driving torque value requested by the driver, and limits the amount of change based on a set value set for each section.

[0011] According to this configuration, it is possible to limit the amount of change depending on each of the first and second sections.

[0012] In the vehicle control device according to the present invention, the limit on the amount of change in the first section is smaller than that in the second section.

[0013] According to this configuration, the vehicle control device reduces the drive torque value quickly in the first section and reduces the drive torque value slowly in the second section. Therefore, the vehicle control device can suppress discomfort caused by deceleration while making the occupant aware that the vehicle is decelerating.

[0014] In the vehicle control device according to the present invention, the torque control unit does not change the drive torque value in a standby section provided between the first section and the second section.

[0015] According to this configuration, the vehicle control device can suppress discomfort caused by deceleration.

[0016] In addition, in the vehicle control device of the present invention, the torque control unit limits the decrease in the driving torque value from the time the detection unit detects the end until the driver torque value, which indicates the torque value requested by the driver, exceeds the driving torque value.

[0017] According to this configuration, the vehicle control device limits the decrease in the torque value until it reaches the torque value requested by the driver, thereby making it possible to suppress abrupt deceleration. [Effects of the Invention]

[0018] The vehicle control device according to the present invention has the effect of being able to suppress sudden deceleration. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a block diagram showing an example of a vehicle according to this embodiment. [Figure 2] FIG. 2 is a block diagram showing an example of functions of an ECU mounted on a vehicle according to this embodiment. [Figure 3] FIG. 3 is a graph showing an example of a change in the driving torque value when the amount of change in the driving torque value is not limited. [Figure 4]FIG. 4 is a graph showing an example of a change in the driving torque value when the amount of change in the driving torque value is limited. [Figure 5] FIG. 5 is a graph showing an example of a change in the driving torque value when the amount of change in the driving torque value is limited. [Figure 6] FIG. 6 is a flowchart showing an example of the torque control process executed by the ECU according to this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0020] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a vehicle control device according to the present invention will be described in detail below with reference to the accompanying drawings.

[0021] 1 is a block diagram showing an example of a vehicle 1 according to this embodiment. The vehicle 1 is equipped with a series hybrid system 10. The hybrid system 10 includes an engine 11, a generator motor 12, a drive motor 13, a battery 14, a PCU (Power Control Unit) 15, and an ECU (Electronic Control Unit) 16.

[0022] The engine 11 is, for example, a gasoline engine. Note that the engine 11 is not limited to gasoline and may use other objects as fuel.

[0023] The generator motor 12 is a motor used for generating electricity. The generator motor 12 has, for example, a permanent magnet synchronous motor. The rotating shaft of the generator motor 12 is mechanically connected to the crankshaft of the engine 11. For example, a motor gear supported on the rotating shaft of the generator motor 12 is arranged to mesh with an engine output gear supported on the crankshaft of the engine 11. In this way, the rotating shaft of the generator motor 12 is connected to the crankshaft of the engine 11.

[0024] The drive motor 13 is a motor that rotates at least one of the front and rear drive wheels 18 of the vehicle 1. The drive motor 13 has, for example, a permanent magnet synchronous motor that is larger than the generator motor 12. The rotating shaft of the drive motor 13 is connected to a drive system 17 that transmits power. The drive system 17 has a differential gear that distributes and transmits power to the left and right drive wheels 18. The drive motor 13 transmits power to the drive wheels 18 via the drive system 17. In this way, the drive motor 13 rotates the drive wheels 18.

[0025] The battery 14 is an assembled battery made up of a plurality of secondary batteries. The secondary batteries are, for example, lithium ion batteries. The battery 14 outputs DC power of, for example, about 200 to 350 V (volts).

[0026] The PCU 15 is a unit for controlling the driving of the generator motor 12 and the drive motor 13. For example, the PCU 15 includes a first inverter 21, a second inverter 22, and a converter .

[0027] When starting the engine 11, the converter 23 boosts the DC power output from the battery 14. The first inverter 21 converts the DC power boosted by the converter 23 into AC power and supplies it to the generator motor 12. This causes the generator motor 12 to rotate its rotating shaft. The engine 11 is mechanically coupled to the rotating shaft of the generator motor 12. Therefore, the engine 11 motors (cranks) using the rotation transmitted from the generator motor 12. The engine 11 then starts when the ignition plug of the engine 11 is sparked after the rotation speed of the crankshaft has increased to the rotation speed required for starting due to motoring.

[0028] When the vehicle 1 is running, the drive motor 13 generates power. When the battery 14 can supply the power required by the drive motor 13, the vehicle 1 runs as an EV (Electric Vehicle) driven by the drive motor 13. In EV running, the engine 11 is stopped and the generator motor 12 does not generate power. The drive motor 13 is driven by the power supplied from the battery 14.

[0029] Furthermore, when the battery 14 cannot supply the power required by the drive motor 13, the vehicle 1 runs as an HV (Hybrid Vehicle) powered by the engine 11 and the drive motor 13. In HV running, the engine 11 operates to generate power through rotation. The generator motor 12 converts the power of the engine 11 into AC power. The first inverter 21 converts the AC power from the generator motor 12 into DC power. The second inverter 22 converts the DC power output from the first inverter 21 into AC power. The drive motor 13 is then driven by the AC power converted by the second inverter 22.

[0030] Furthermore, when the remaining capacity of the battery 14 is less than a threshold, the vehicle 1 charges the battery 14 with electric power generated using the engine 11. More specifically, when the remaining capacity of the battery 14 is less than a threshold, the engine 11 is in an operating state regardless of whether the drive motor 13 is running or stopped. Furthermore, the generator motor 12 generates AC power using the power of the engine 11. The first inverter 21 converts the AC power of the generator motor 12 into DC power. The second inverter 22 converts the DC power output from the first inverter 21 into AC power. The converter 23 steps down the DC power output from the first inverter 21. The battery 14 is then charged with the DC power after the step-down.

[0031] When the vehicle 1 decelerates, the drive motor 13 generates electricity through regeneration. That is, the drive motor 13 converts the power transmitted from the drive wheels 18 into AC power. At this time, the regenerative torque applied to the rotation of the drive motor 13 acts as a regenerative brake that brakes the vehicle 1. The second inverter 22 converts the AC power supplied from the drive motor 13 into DC power. The converter 23 steps down the DC power output from the second inverter 22. The battery 14 is then charged with the DC power stepped down by the converter 23.

[0032] The ECU 16 controls the hybrid system 10. That is, the ECU 16 controls the vehicle 1 equipped with a drive motor 13 that performs regenerative braking when the driver releases the accelerator. The ECU 16 includes a microcontroller having a processor such as a CPU (Central Processing Unit), a memory, and a RAM (Random Access Memory). The processor controls the hybrid system 10. The memory is a storage device that stores data even when power is not supplied, such as a ROM (Read Only Memory) or flash memory. The RAM is a storage device that retains data when power is supplied, such as a DRAM.

[0033] The ECU 16 is connected to a communication interface 31 that communicates with other devices in the vehicle 1. The communication interface 31 communicates with other devices in the vehicle 1 using a communication protocol such as CAN (Controller Area Network).

[0034] Also connected to the ECU 16 are an accelerator sensor 32, a vehicle speed sensor 33, a forward recognition camera 34 (external environment recognition means that recognizes the external environment around the vehicle 1), and an ACC selector switch 35. The accelerator sensor 32 outputs a detection signal that indicates the amount of operation of the accelerator pedal depressed by the driver. The vehicle speed sensor 33 outputs a pulse signal as a detection signal that is synchronized with the rotation of a rotating body that rotates as the vehicle 1 travels. The ECU 16 calculates the accelerator opening, which is the ratio of the current operation amount to the maximum operation amount of the accelerator pedal, from the detection signal of the accelerator sensor 32. The ECU 16 also calculates the frequency of the detection signal output from the vehicle speed sensor 33 and converts the calculated frequency into vehicle speed.

[0035] The forward recognition camera 34 is, for example, a stereo camera. A stereo camera is a camera that can continuously capture still images at a predetermined frame rate and can detect the distance to the position of a target in the captured image from parallax information. The stereo camera is installed, for example, on the windshield surface behind the rearview mirror in the front center of the vehicle interior so that it can capture images of the area ahead of the vehicle 1 at a wide angle. In addition to the stereo camera, the vehicle 1 may also be provided with a radar as a unit that recognizes the outside world. The radar is installed in the front of the vehicle 1 and is a sensor for detecting the situation in a predetermined search range ahead of the vehicle 1. The radar irradiates radar waves (millimeter waves, laser) into the search range, receives reflected waves from objects present within the search range, and outputs a detection signal corresponding to the reflected waves.

[0036] The output of the forward recognition camera 34 is output to the ECU 16. Based on the image captured by the forward recognition camera 34, the ECU 16 calculates data necessary to operate the ACC function, such as the relative speed between the vehicle 1 and a target such as a preceding vehicle, the target inter-vehicle distance from the preceding vehicle, and the target acceleration / deceleration when following the preceding vehicle.

[0037] Furthermore, when the distance between the preceding vehicle and vehicle 1 becomes wider than the target distance and acceleration (or becomes narrower and deceleration is required) becomes necessary, ECU 16 transmits a control signal to engine 11. When engine 11 receives the control signal, it transmits a throttle control signal to the throttle body to control the throttle opening, and also transmits a fuel injection control signal to the fuel injector to control the amount of fuel injected, in order to realize acceleration based on the signal.

[0038] Normally (when the ACC function is not activated), the ECU 16 controls the throttle opening and closing of the engine 11 and the amount of fuel injected by the fuel injector so that a driving torque corresponding to the accelerator operation amount (accelerator opening degree) detected by the accelerator sensor 32 is output. On the other hand, when the ACC function is activated, as described above, the ECU 16 controls the throttle opening and the amount of fuel injected based on the control signal so that the acceleration corresponds to the signal, regardless of the accelerator operation amount.

[0039] The ACC function is a follow-up cruise control that causes the vehicle 1 to follow a preceding vehicle ahead of the vehicle. For example, the steering wheel is provided with an ACC selector switch 35 that accepts an operation to switch the control by the ACC function on and off. When the ACC selector switch 35 is operated, the ECU 16 starts or ends the control by the ACC function. In ACC control (follow-up cruise control), which causes the vehicle 1 to follow a preceding vehicle ahead of the vehicle, the vehicle automatically switches between following the preceding vehicle and constant speed cruise at a predetermined vehicle speed depending on whether or not there is a preceding vehicle. During follow-up cruise, the vehicle 1 is accelerated or decelerated so that the distance between the vehicle 1 and the preceding vehicle ahead of the vehicle is maintained at a target distance.

[0040] Specifically, a target inter-vehicle distance between vehicle 1 and a preceding vehicle is set based on the vehicle speed of vehicle 1, and ECU 16 determines the inter-vehicle distance deviation between the target inter-vehicle distance and the actual inter-vehicle distance (= actual inter-vehicle distance - target inter-vehicle distance). ECU 16 also determines the relative speed between vehicle 1 and the preceding vehicle. ECU 16 then sets a target acceleration / deceleration for vehicle 1 according to the inter-vehicle distance deviation and the relative speed. A memory built into the microcontroller of ECU 16 stores the characteristics (relationships) of the target acceleration / deceleration with respect to the inter-vehicle distance deviation and the relative speed in the form of a map, as a target acceleration / deceleration map. Once the target acceleration / deceleration is set, the output of engine 11 is controlled so that vehicle 1 accelerates or decelerates at the target acceleration / deceleration (automatic acceleration / deceleration).

[0041] 2 is a block diagram showing an example of functions of the ECU 16 mounted on the vehicle 1 according to this embodiment. The CPU of the ECU 16 executes programs stored in a memory or the like to implement functional units such as an ACC control unit 161, an accelerator input unit 162, an ACC end detection unit 163, a torque control unit 164, and a drive control unit 165. Note that all or part of these functional units may be implemented by hardware such as a semiconductor circuit.

[0042] The ACC control unit 161 controls the traveling of the vehicle 1 using ACC. ACC is a function that assists in following a preceding vehicle traveling ahead of the vehicle 1. More specifically, the ACC control unit 161 calculates an ACC torque value that indicates the torque value for driving the driving wheels 18 in ACC. For example, the ACC control unit 161 calculates the ACC torque value based on the distance between the vehicle 1 and the preceding vehicle, the vehicle speed of the vehicle 1, and the like. Here, a lower limit is set for the driving torque value (required driving torque) that indicates the torque value for driving the driving wheels 18 of the vehicle 1 in ACC. The ACC control unit 161 calculates the ACC torque value so that it does not fall below the lower limit.

[0043] The ACC end detection unit 163 detects an end condition for ending follow-up driving, which follows a preceding vehicle traveling ahead of the vehicle 1. That is, the ACC end detection unit 163 detects an end condition for the ACC. For example, the end condition is when the ACC changeover switch 35, which is provided on the steering wheel or the like and accepts an operation to end the ACC, is pressed, the brake pedal is depressed, the transmission range is changed, or the preceding vehicle can no longer be detected, making it impossible to continue the ACC. When the ACC end detection unit 163 detects an end condition, the ECU 16 ends control of the vehicle 1 by the ACC.

[0044] Accelerator input unit 162 receives accelerator operation by the driver. More specifically, accelerator input unit 162 receives a detection signal indicating the amount of accelerator pedal operation output from accelerator sensor 32. Accelerator input unit 162 also calculates a driver torque value (user requested torque) indicating the torque value for driving drive wheels 18 according to the amount of accelerator pedal operation.

[0045] Torque control unit 164 calculates a drive torque value that indicates the value of the torque that drives drive wheels 18 of vehicle 1. While traveling using ACC, torque control unit 164 compares the ACC torque value calculated by ACC control unit 161 with the driver torque value calculated by accelerator input unit 162, and sets the larger value as the drive torque value.

[0046] Next, the driving torque value when ACC ends will be described with reference to FIGS.

[0047] Fig. 3 is a graph showing an example of the change in the drive torque value (required drive torque value) when the amount of change in the drive torque value is not limited. Fig. 4 is a graph showing an example of the change in the drive torque value when the amount of change in the drive torque value is limited. Fig. 5 is a graph showing an example of the change in the drive torque value when the amount of change in the drive torque value is limited. The horizontal axis of the graphs shown in Figs. 3 and 4 represents time (S·seconds), and the vertical axis represents the drive torque value (Nm·Newton meters).

[0048] First, a case where the amount of change in the drive torque value is not limited will be described.

[0049] 3, when the ACC termination condition is detected by the ACC termination detection unit 163, the ACC control unit 161 terminates calculation of the ACC torque value to terminate traveling by ACC. Then, the ACC torque value becomes the ACC lower limit torque value, which is the lower limit value for ACC.

[0050] When ACC ends, the vehicle 1 is manually driven by the driver operating the driving torque value by depressing the accelerator pedal. In other words, when ACC ends, the driving torque value becomes the driver torque value, which is the torque requested by the driver by depressing the accelerator pedal. Therefore, the driving torque value becomes a value corresponding to the detection signal received by the accelerator input unit 162.

[0051] Here, when the drive motor 13 generates electricity through regeneration, the vehicle 1 applies regenerative braking. The graph shown in FIG. 3 illustrates a case where the amount of change in the drive torque value is not limited. Therefore, as shown in FIG. 3, when the driver does not depress the accelerator pedal and no driver torque value is generated, the drive torque value decreases rapidly, causing regenerative braking with a strong jerk. In particular, during ACC, the driver (user) often releases the accelerator pedal and prepares to depress the brake pedal (accelerator release operation). When ACC ends, the drive torque transitions (switches) from the ACC request torque to the user request torque. Therefore, if the driver releases the accelerator, strong regenerative braking is activated when ACC ends. At this time, the passengers are placed in an uncomfortable position, such as leaning forward as if the brakes were applied suddenly. Therefore, the torque control unit 164 limits the amount of change in the drive torque value (including the actual drive torque value and the drive request torque value, which is a drive command) that drives the drive wheels 18 of the vehicle 1. During ACC, a relatively weak regenerative brake is applied to automatically decelerate to maintain the target inter-vehicle distance.The accelerator release operation mentioned above is intended to include the state in which the driver is operating the accelerator pedal (accelerator operating means) in the release direction, such as by loosening the accelerator pedal or completely releasing it.

[0052] Next, a case where the amount of change in the drive torque value is limited will be described.

[0053] As shown in FIG. 4 , when ACC, which follows a preceding vehicle traveling ahead of the vehicle 1, ends, the torque control unit 164 limits the amount of change in the drive torque value that drives the drive wheels 18 of the vehicle 1 from the ACC torque value, which indicates the torque value requested in the ACC, until it reaches the driver torque value, which indicates the torque value requested by the driver. More specifically, when the ACC end detection unit 163 detects an ACC end condition, the torque control unit 164 limits the decrease in the drive torque value from the detection of the end condition until the drive torque value reaches the driver torque value. Here, the torque control unit 164 calculates the drive torque value at regular intervals. For example, the torque control unit 164 calculates the drive torque value every 0.008 seconds. At this time, the torque control unit 164 limits the amount of change in the drive torque value. This prevents the drive torque value from decreasing too rapidly. Then, when the drive torque value reaches the driver torque value, the torque control unit 164 ends the limit on the amount of change in the drive torque value.

[0054] Torque control unit 164 divides the period during which the amount of change in the drive torque value is limited into multiple sections, and limits the amount of change based on a set value set for each section. As shown in Fig. 4, torque control unit 164 divides the period into a first section from the end of ACC to the ACC lower limit torque value, a standby section in which the drive torque value is not changed, and a second section from the ACC lower limit torque value to the driver torque value, and limits the amount of change based on a set value set for each section.

[0055] The torque control unit 164 limits the amount of change in the driving torque value per time in the first section to a first set value or less. The first set value is a value indicating the amount of change allowed in the driving torque value in the first section. The torque control unit 164 limits the amount of change in the driving torque value per time in the second section to a second set value or less. The second set value is a value indicating the amount of change allowed in the driving torque value in the second section. The limit on the amount of change in the driving torque value in the first section is smaller than that in the second section. In other words, the first set value is higher than the second set value. As a result, the driving torque value decreases more quickly in the first section, and the driving torque value decreases more slowly in the second section than in the first section.

[0056] In the graph shown in Fig. 4, the driver torque value does not increase even after ACC ends. In other words, the driver is not depressing the accelerator pedal and is trying to decelerate the vehicle 1. In such a case, if the decrease in the driving torque value is made gradual, the driver may feel that a malfunction has occurred. Therefore, the torque control unit 164 makes the amount of change in the driving torque value in the first section greater than the amount of change in the second section, making it easier to understand that the vehicle 1 is decelerating.

[0057] Furthermore, as shown in Fig. 4, the torque control unit 164 does not change the drive torque value during the standby period between the first and second periods. The torque control unit 164 does not change the drive torque value during the standby period, for example, one second. This gives the passenger the feeling that the vehicle is decelerating gradually. Therefore, the torque control unit 164 can reduce the passenger's discomfort.

[0058] Next, a case where the accelerator pedal is depressed while the amount of change in the drive torque value is limited will be described.

[0059] As shown in Fig. 5, when the driver torque value becomes equal to or greater than the driving torque value, the torque control unit 164 sets the driver torque value to the driving torque value. After the driver torque value becomes equal to or greater than the driving torque value, the torque control unit 164 sets the driver torque value to the driving torque value. Note that in the graph shown in Fig. 5, the torque control unit 164 sets the driver torque value to the driving torque value in the second section. However, the torque control unit 164 may set the driver torque value to the driving torque value in the first section or the standby section.

[0060] The drive control unit 165 controls the engine 11, the PCU 15, etc., to drive the drive wheels 18 at the drive torque value calculated by the torque control unit 164. For example, every time the torque control unit 164 calculates a drive torque value, the drive control unit 165 drives the drive wheels 18 at the calculated drive torque value. The torque control unit 164 and the drive control unit 165 repeatedly calculate the drive torque value and drive the vehicle 1 at the calculated drive torque value, thereby gradually decelerating the vehicle 1.

[0061] Next, a description will be given of a torque control process for controlling the drive torque value by the ECU 16. Fig. 6 is a flowchart showing an example of the torque control process executed by the ECU 16 according to this embodiment.

[0062] The ACC end detection unit 163 determines whether or not an end condition for ending ACC has been detected (step S1).

[0063] If the end condition has not been detected (step S1; No), the torque control unit 164 compares the ACC torque value with the driver torque value, and sets the larger value as the drive torque value (step S2).

[0064] When the termination condition is detected (step S1; Yes), the torque control unit 164 determines whether the driver torque value is greater than the previous driving torque value (step S3). When the driver torque value is greater than the previous driving torque value (step S3; No), the torque control unit 164 sets the driver torque value to the driving torque value (step S4). Then, the ECU 16 terminates the torque control process.

[0065] If the driver torque value is smaller than the previous driving torque value (step S3; Yes), the torque control unit 164 determines whether the previous driving torque value is larger than the ACC lower limit torque value (step S5). In other words, the torque control unit 164 determines whether the current section is the first section.

[0066] If the previous drive torque value is greater than the ACC lower limit torque value (step S5; Yes), the torque control unit 164 determines whether the value obtained by subtracting the previous drive torque value from the ACC lower limit torque value is less than a first set value (step S6). In other words, the torque control unit 164 determines whether the amount of change in the drive torque value is smaller than the first set value.

[0067] If the value obtained by subtracting the previous drive torque value from the ACC lower limit torque value is smaller than the first set value (step S6; Yes), the torque control unit 164 sets the drive torque value to the value obtained by adding the first set value to the previous drive torque value (step S7). In other words, the torque control unit 164 sets the minimum change amount of the drive torque value to the first set value (the first set value is a negative value).

[0068] If the value obtained by subtracting the previous driving torque value from the ACC lower limit torque value is equal to or greater than the first set value (step S6; No), the torque control unit 164 sets the ACC lower limit torque value as the driving torque value (step S8).

[0069] In step S5, if the previous drive torque value is equal to or less than the ACC lower limit torque value (step S5; No), the torque control unit 164 determines whether or not the standby time has elapsed since the drive torque value became equal to or less than the ACC lower limit torque value (step S9). In other words, the torque control unit 164 determines whether or not the standby time has elapsed in the standby section.

[0070] If the waiting time has not elapsed (step S9; No), the torque control unit 164 sets the ACC lower limit torque value as the drive torque value (step S10).

[0071] If the standby time has elapsed (step S9; Yes), the torque control unit 164 determines whether or not the value obtained by subtracting the second set value from the previous driving torque value is greater than the driver torque value (step S11).

[0072] If the value obtained by subtracting the second set value from the previous driving torque value is greater than the driver torque value (step S11; Yes), the torque control unit 164 sets the value obtained by subtracting the second set value (positive value) from the previous driving torque value as the driving torque value (step S12).

[0073] If the value obtained by subtracting the second set value from the previous driving torque value is equal to or less than the driver torque (step S11; No), the torque control unit 164 sets the driver torque value to the driving torque value in step S4. Then, the ECU 16 ends the torque control process.

[0074] In this way, when ACC ends, the ECU 16 according to this embodiment limits the amount of change in the drive torque value that drives the drive wheels 18 of the vehicle 1 from the ACC torque value, which indicates the torque value requested in ACC, until it reaches the driver torque value, which indicates the torque value requested by the driver. Thus, the ECU 16 can suppress abrupt deceleration.

[0075] Although the present invention has been described above with reference to certain preferred embodiments, it is to be understood that the present invention may be embodied in other forms.

[0076] <Modification> It has been explained that when the ACC termination condition is satisfied, the ECU 16 executes the torque control process to limit the amount of change in the drive torque value during deceleration of the vehicle 1. However, even when the ACC termination condition is satisfied, the ECU 16 may omit all or part of the torque control process when an invalidation condition is satisfied that invalidates the limit on the amount of change in the drive torque value.

[0077] For example, ECU 16 may omit all or part of the torque control process and reduce the drive torque value to the driver torque value without limiting the amount of change in the first section, the waiting section, and the second section as shown in Figure 3, or may limit the amount of change in the first section and reduce the drive torque value to the driver torque value without limiting the amount of change in the waiting section and the second section.

[0078] For example, when the brake pedal is depressed, the driver is trying to stop the vehicle 1. In this case, the ECU 16 may omit all or part of the torque control process that limits the amount of change in the drive torque value. On the other hand, when the brake pedal is slightly depressed due to an erroneous operation or the like, the ECU 16 may limit the amount of change in the drive torque value. Therefore, when the amount of operation of the brake pedal is equal to or greater than a threshold value as an invalid condition, the ECU 16 may omit all or part of the torque control process that limits the amount of change in the drive torque value.

[0079] Furthermore, when the transmission range of the vehicle 1 is changed to a range that applies strong regenerative braking, the driver expects strong regenerative braking. Furthermore, a change in the transmission range is an end condition for ACC. When the ECU 16 detects a change to a range that applies strong regenerative braking as both an end condition and an invalid condition, the ECU 16 may omit all or part of the torque control process that limits the amount of change in the drive torque value.

[0080] The first set value, the waiting time for the waiting section, and the second set value are not limited to fixed values, but may be calculated variable values. For example, the ECU 16 determines the total execution time of the first section, the waiting section, and the second section. The ECU 16 calculates the first set value, the waiting time, and the second set value that can reduce the current traveling speed of the vehicle 1 to the driver torque value within the total time. The ECU 16 then executes torque control processing to limit the amount of change in the drive torque value based on the calculated first set value, the waiting time, and the second set value. Note that the ECU 16 may determine the execution time of the first section, not limited to the total time of the first section, the waiting section, and the second section, and calculate the first set value that can reduce the current traveling speed of the vehicle 1 to the ACC lower limit torque value within the execution time. The ECU 16 may also determine the execution time of the second section and calculate the second set value that can reduce the ACC lower limit torque value to the driver torque value within the execution time.

[0081] Alternatively, the ECU 16 may limit the amount of change in the first section by the access opening rate, and may limit the amount of change in the second section by the drive torque value. That is, the ECU 16 may control the drive torque value by the access opening rate in the first section.

[0082] Furthermore, the ECU 16 does not need to provide a standby section between section 1 and section 2. Furthermore, the present invention is not limited to series hybrid vehicles, but may also be applied to parallel hybrid vehicles, electric vehicles, and fuel cell vehicles.

[0083] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the present invention. [Explanation of symbols]

[0084] 1 vehicle 10 Hybrid System 11 Engine 12 Generator motor 13 Drive motor 14 Battery 15 PCU (Power Control Unit) 16 ECU(Electronic Control Unit) 18 Drive wheels 17 Drivetrain 21 First inverter 22 Second inverter 23 Converter 31 Communication Interface 32 Accelerator sensor 33 Vehicle speed sensor 34 Forward Recognition Camera 35 ACC selector switch 161 ACC control unit 162 Accelerator input section 163 ACC end detection unit 164 Torque control section 165 Drive control unit

Claims

1. A vehicle control device that controls a vehicle equipped with a drive motor that performs regenerative braking when an accelerator pedal is released by a driver, a torque control unit that, when a follow-up driving operation of following a preceding vehicle traveling ahead of the vehicle is completed, limits a change amount of a drive torque value that drives the drive wheels of the vehicle from an Adaptive Cruise Control (ACC) torque value that indicates a torque value requested during the follow-up driving operation until the change amount reaches a driver torque value that indicates a torque value requested by a driver; Equipped with The torque control unit divides the period into a first section, which is a period until the drive torque value reaches a follow-up driving lower limit torque value that indicates the lower limit of the drive torque value in the follow-up driving, a second section, which is a period from the follow-up driving lower limit torque value to a driver torque value that indicates the drive torque value requested by the driver, and a standby section, which is a period provided between the first section and the second section and in which the drive torque value is not changed, and limits the amount of change based on a set value set for each section. Vehicle control device.

2. A vehicle control device that controls a vehicle equipped with a drive motor that performs regenerative braking when an accelerator pedal is released by a driver, a torque control unit that, when a follow-up driving operation of following a preceding vehicle traveling ahead of the vehicle is completed, limits a change amount of a drive torque value that drives drive wheels of the vehicle from an Adaptive Cruise Control (ACC) torque value that indicates a torque value requested during the follow-up driving operation until the drive torque value reaches a driver torque value that indicates a torque value requested by the driver; Equipped with The torque control unit When the vehicle is traveling by the following traveling, the ACC torque value and the driver torque value are compared, and the larger value is set as the drive torque value; When the following traveling is ended, if the driving torque value reaches the driver torque value, the limit on the amount of change in the driving torque value is ended. Vehicle control device.

3. the limit on the amount of change in the first section is smaller than the limit on the amount of change in the second section; The vehicle control device according to claim 1 .

4. the torque control unit ends the limitation on the amount of change in the driving torque value when the driving torque value reaches the driver torque value. The vehicle control device according to any one of claims 1 to 3.

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