Vehicle deceleration control device

Abstract

To provide a deceleration control device of a vehicle, which performs control so that deceleration does not give a feeling of strangeness when switching control of automatically setting deceleration during coasting of the vehicle to control of setting deceleration by manual operation.SOLUTION: A deceleration control device of a vehicle is provided with: a current mode determining part that determines that predetermined deceleration is set in a third deceleration mode of automatically setting deceleration during coasting of the vehicle on the basis of a travelling state of the vehicle (step S3); a manual deceleration detecting part that detects that a deceleration switching signal based on manual operation by a driver is generated in a state where the predetermined deceleration is set in the third deceleration mode (step S5); and deceleration transition instructing parts that set deceleration determined by adding or subtracting deceleration corresponding to the signal based on the manual operation by the driver to or from the predetermined deceleration, when it is detected that the signal based on the manual operation by the driver is generated in a state where it is determined that the predetermined deceleration is set in the third deceleration mode (steps S6 and S7).SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a device for controlling the deceleration of a vehicle while it is running, and more particularly to a device for controlling the deceleration of a vehicle when the required driving force represented by the accelerator opening or the like becomes zero and the vehicle coasts.

Background Art

[0002] The acceleration and deceleration of a vehicle are usually performed by operating an acceleration / deceleration operation unit represented by an accelerator pedal. That is, for example, when the accelerator pedal is depressed, the output of the driving force source is increased, or the driving torque is increased by increasing the gear ratio in combination therewith. Conversely, when the accelerator pedal is released, the output of the driving force source is decreased, or it is controlled to have a negative torque, and further, the gear ratio is increased in combination therewith, so that the torque of the driving wheels becomes a negative torque, that is, a braking force. The driving force (acceleration) and braking force (deceleration) controlled in this way greatly affect the drivability of the vehicle. If the acceleration or deceleration with respect to the acceleration / deceleration operation amount is small, the behavior of the vehicle becomes slow. On the contrary, if the acceleration or deceleration with respect to the acceleration / deceleration operation amount is large, the behavior of the vehicle becomes sensitive. However, if those behaviors deviate from what the driver intends, the vehicle becomes difficult to drive.

[0003] The braking state or braking force when the accelerator pedal is released and the accelerator opening becomes zero is engine braking (power source braking) or engine braking force (referred to as power source braking force. In a vehicle with an engine as the driving force source, the engine braking force is generated by the resistance when the engine with the fuel supply stopped is forcibly rotated. In a vehicle equipped with a transmission, the braking force or deceleration in the engine braking state is increased by increasing the gear ratio. Further, in a vehicle equipped with an electric motor having a power generation function as the driving force source, the power source braking force is generated by the negative torque associated with the energy regeneration by the electric motor. In that case, the braking force (deceleration) can be controlled by controlling the amount of energy regeneration.

[0004] In a so-called coasting state where the accelerator pedal is released to set the accelerator opening to zero, the deceleration due to engine braking force, etc., is basically determined by the configuration of the power train, but it can also be changed in magnitude depending on the gear ratio, energy regeneration amount, etc. Therefore, some vehicles are equipped with a system that controls the deceleration according to the selected driving mode so that the deceleration corresponding to the driving mode is achieved. For example, when the normal mode and the power mode can be selected, the deceleration in the power mode is controlled to be greater than the deceleration in the normal mode. Also, when coasting down a slope, the deceleration is controlled to be greater than the deceleration on a flat road so as to suppress the increase in vehicle speed due to gravitational acceleration. Furthermore, in vehicles capable of DMD (Driver’s Mind D-Shift) control (DMD mode), the acceleration or deceleration corresponding to the accelerator opening is generated based on the learned acceleration history and deceleration history of the driver.

[0005] The above-described deceleration control is often configured to achieve a predetermined deceleration as a system in design. In contrast, the control device described in Patent Document 1 determines the target vehicle deceleration at the start of free-run control based on the gradient of the road surface. Here, free-run refers to a driving state in which the transmission of driving force between the engine and the drive wheels is interrupted and the engine is stopped during coasting with the accelerator pedal released. In the control device described in Patent Document 1, the braking force (deceleration) during free-run control is generated by an electric motor having a power generation function. And when the actually estimated deceleration is significantly different from the target vehicle deceleration, the free-run control is prohibited so as not to cause a sense of discomfort.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] Driving power sources such as engines and electric motors generate the driving power for the vehicle to travel. However, if the output of the driving power is stopped while the vehicle is running, the driving power source will be forced to rotate by the inertia force of the vehicle, thereby generating a braking force (driving power source braking force or engine braking force). The braking force can be appropriately set by controlling the driving power source, the gear ratio in the transmission connected thereto, and further the braking device. An example thereof is the control device described in Patent Document 1 mentioned above. However, including the control device described in Patent Document 1 and the control devices having a coasting deceleration increasing function such as the control on a downhill slope and DMD control described above, conventionally, they are configured as a system pre-mounted on the vehicle, and the braking force during coasting is automatically set according to the running state or driving state of the vehicle. Therefore, the braking force has to be the braking force determined in the design and does not necessarily reflect the intention or driving orientation of the driver.

[0008] On the other hand, since the braking force during coasting can be automatically controlled as described above, if a signal input to the system therefor is generated, for example, by manually operating a shift paddle or the like, based on the manual operation, the braking force during coasting can be generated or changed in magnitude. However, a system for setting or controlling the braking force during coasting based on such manual operation is not only not described in Patent Document 1 and has not been particularly known conventionally, but also regarding the control when switching from the control by a system that automatically sets or controls the braking force or deceleration to the control for setting the braking force or deceleration during coasting based on manual operation, it has not been known conventionally. In order to perform a smooth switching without a sense of incongruity in these controls to improve the ride comfort or drivability of the vehicle, the actual situation is that a new technology is required.

[0009] The present invention is made by paying attention to the above technical problems, and it is possible to switch from the control for automatically setting the deceleration during the coasting of the vehicle to the control for setting the deceleration based on manual operation, and an object of the present invention is to provide a deceleration control device that can control so that the deceleration at the time of the switching does not cause a sense of discomfort.

Means for Solving the Problems

[0010] In order to achieve the above object, the present invention provides a first deceleration mode for setting the deceleration during coasting when the acceleration demand amount is zero to a predetermined deceleration, a second deceleration mode for increasing or decreasing the deceleration by a signal based on a manual operation of the driver, and a third deceleration mode for setting a predetermined deceleration greater than the deceleration by the first deceleration mode based on a detection signal from a sensor for detecting a running state. The vehicle deceleration control device includes a current mode determination unit for determining that the predetermined deceleration is set by the third deceleration mode, a manual deceleration detection unit for detecting that the signal based on the manual operation of the driver has occurred in a state where it is determined that the predetermined deceleration is set by the third deceleration mode, and when it is detected that the signal based on the manual operation of the driver has occurred in a state where it is determined that the predetermined deceleration is set by the third deceleration mode, a deceleration transition instruction unit for setting a deceleration obtained by adding or subtracting the deceleration corresponding to the signal based on the manual operation of the driver to or from the predetermined deceleration. When the signal based on the manual operation by the driver occurs, a plurality of deceleration rates for the second deceleration mode for transitioning from the predetermined deceleration rate set in the first deceleration mode are determined in advance. When it is detected that the signal based on the manual operation of the driver has occurred in a state where it is determined that the predetermined deceleration rate is set by the third deceleration mode, among the deceleration rates for the second deceleration mode, in the increasing or decreasing direction of the deceleration rate corresponding to the signal based on the manual operation of the driver, it instructs to transition to the deceleration rate closest to the predetermined deceleration rate. It is characterized by the above.

[0012] In the present invention, the vehicle may further include a torque control unit for controlling the electric motor so as to generate a deceleration in the first deceleration mode to the third deceleration mode, the electric motor outputs a negative torque that decelerates the vehicle by regenerating energy as a driving power source.

Effects of the Invention

[0013] In the present invention, it is determined by the current mode determination unit that the third deceleration mode is set. In that case, as the deceleration during coasting, a deceleration greater than the deceleration set in the first deceleration mode and based on the detection signal from a predetermined sensor is set. In this state, when the manual deceleration detection unit detects that a signal based on the driver's manual operation has occurred, the deceleration transition instruction unit gives an instruction to set a deceleration obtained by adding or subtracting an amount of deceleration corresponding to the detected signal to the deceleration currently set in the third deceleration mode. That is, when a manual operation for increasing or decreasing the deceleration is performed in a state where the deceleration is automatically set based on the detection result of the sensor, the deceleration is increased or decreased with reference to the current deceleration. Therefore, the amount of change in the deceleration becomes an amount without excess or deficiency based on the manual operation, and thus a sense of discomfort such as a so-called "missing feeling of deceleration" in which the deceleration excessively decreases can be avoided.

[0014] Also, in the present invention, when the driver performs a manual operation to change (or select) the deceleration, the second deceleration mode is set, and a deceleration corresponding to the manual operation is selected and set from among a plurality of decelerations for the second deceleration mode. When such a manual operation for switching to the second deceleration mode is executed in a state where the deceleration by the third deceleration mode is set, among the decelerations for the second deceleration mode, the deceleration closest to the current deceleration by the third deceleration mode and in the increasing or decreasing direction of the deceleration corresponding to the signal based on the manual operation is selected and set. That is, even if the deceleration for the second deceleration mode is a deceleration for transitioning from a predetermined deceleration in the first deceleration mode, when switching to the second deceleration mode in a state where the third deceleration mode is set, the deceleration closest to the current deceleration set in the third deceleration mode (closest in the increasing or decreasing direction indicated by the signal) is instructed and set. Therefore, the amount of change in the deceleration becomes an amount without excess or deficiency based on the manual operation, in other words, the amount of change intended by the driver, and thus a sense of discomfort such as a so-called "missing feeling of deceleration" in which the deceleration excessively decreases can be avoided.

[0015] Furthermore, if the configuration is such that the deceleration is generated by the energy regeneration torque of the electric motor, it becomes possible to perform deceleration control with no response delay and high accuracy.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0017] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the embodiments described below are merely examples of implementing the present invention and do not limit the present invention.

[0018] The vehicle in an embodiment of the present invention is a vehicle that accelerates and decelerates when a driver operates an accelerator pedal or the like. In particular, in a coasting state where the acceleration demand amount by an accelerator pedal or the like is zero, it is a vehicle that can control the braking force (engine braking force or driving force source braking force) by a driving force source to be large or small. An example thereof is a hybrid vehicle (HEV) or an electric vehicle (EV) equipped with an electric motor as a driving force source, and an EV1 is schematically shown in FIG. 1.

[0019] EV1 is equipped with an electric motor 2 having a power generation function (energy regeneration function) as a driving force source. This electric motor 2 is, for example, a permanent magnet synchronous motor (motor - generator. MG). The electric motor 2 is connected to a power storage device 4 such as a battery via an inverter (INV) 3. That is, the direct current of the power storage device 4 is converted into alternating current by the inverter 3 and supplied to the electric motor 2, and the output torque and rotational speed of the electric motor 2 are controlled. Also, the electric power generated by the electric motor 2 is converted into direct current by the inverter 3 and used to charge the power storage device 4.

[0020] The output shaft of the electric motor 2 is directly connected to the differential gear 5, which is the final reduction gear, or is connected thereto via an appropriate transmission mechanism (not shown). The drive torque output from the electric motor 2 is transmitted from the differential gear 5 to the left and right drive wheels 6 to enable the vehicle to travel.

[0021] An accelerator pedal 7 is provided as an operation unit for performing acceleration and deceleration operations. The accelerator pedal 7 is a pedal that, similar to that of a conventional vehicle, the driver steps on for acceleration operation and steps back for deceleration operation, and an accelerator sensor 8 for detecting the amount of depression (accelerator opening) or the stepping force thereof is provided. Further, a select lever 9 is provided for manually selecting the deceleration during coasting when the accelerator pedal 7 is fully stepped back to make the accelerator opening (or drive demand amount) zero. The select lever 9 is provided at an appropriate location such as a steering column or a center console (each not shown) so that the driver can perform a manual operation or a finger operation. For example, depending on the operation direction (increase / decrease direction) from the neutral position, it is configured to increase or decrease the deceleration. A select sensor 10 for detecting the content of the operation by the driver, such as the operation direction (increase / decrease direction) of the select lever 9, or the request for increasing / decreasing the deceleration is provided.

[0022] An electronic control unit (ECU) 11 is provided for controlling the driving force of the electric motor 2 and the braking force associated with energy regeneration. The ECU 11 is mainly composed of a microcomputer including an arithmetic element (CPU), a memory, and an input / output interface, and is configured to output a control signal to the inverter 3 to control the drive torque, braking force (power generation amount), etc. output by the electric motor 2. The aforementioned accelerator sensor 8 and select sensor 10 are connected to this ECU 11. Further, sensors 12 such as a vehicle speed sensor and an acceleration sensor are connected to the ECU 11. That is, the ECU 11 is configured to perform calculations using the detection signals (information) from the sensors and data such as maps stored in advance, and output the results of the calculations as control command signals to the inverter 3 and the like.

[0023] Note that the above EV1 is configured to run when the driver performs operations such as starting, accelerating, decelerating, stopping, and steering, and in this regard, it is not different from a conventional general vehicle. Therefore, although not particularly shown, the EV1 is equipped with a steering mechanism for steering either the front or rear steering wheels, a brake pedal, brakes, a shift mechanism for selecting a driving range (position), etc., in the same manner as a general vehicle.

[0024] In the embodiment of the present invention, among the controls for the driving force and braking force executed by the above ECU11, the control of the braking force (deceleration) during coasting is characteristic. The deceleration control in the embodiment of the present invention is executed in a state where the accelerator pedal 7 is depressed and released and the accelerator opening becomes zero during the running of the EV1, and is provided with three controls: a first deceleration mode, a second deceleration mode, and a third deceleration mode.

[0025] The first deceleration mode is a so-called normal mode. When the EV1 is running under control to generate a driving force (acceleration) without excess or deficiency in a state where the energy efficiency (power consumption rate, electricity cost) is good, and the accelerator opening becomes zero, it is a mode for controlling the regenerative braking force of the electric motor 2 so that a deceleration occurs without causing a sense of discomfort. The deceleration is predetermined in relation to the vehicle speed in terms of design, and is stored in the ECU11 as a map, for example. FIG. 2 shows the deceleration for each vehicle speed, and the curve marked with the symbol "L1" indicates the deceleration in the first deceleration mode.

[0026] The second deceleration mode is a so-called manual deceleration mode, which is executed, for example, when the driver operates the aforementioned select lever 9 or operates the shift mechanism. Specifically, the second deceleration mode is control to increase or decrease the deceleration according to the operation direction and operation amount of the driver. When an operation to decrease the deceleration is performed, it is controlled to a deceleration smaller than the deceleration set in the first deceleration mode described above. Conversely, when an operation to increase the deceleration is performed, it is controlled to a deceleration larger than the deceleration in the first deceleration mode described above. The deceleration set in this way may be configured to increase or decrease linearly according to the operation direction and operation amount by the driver. Alternatively, a deceleration for the second deceleration mode, which is a deceleration different from the deceleration set in the first deceleration mode, may be predetermined, and these decelerations for the second deceleration mode may be selected and set according to the manual selection operation by the driver.

[0027] An example thereof is shown together in FIG. 2, and the curves labeled with reference numerals "L2-1", "L2-2", and "L2-3" show the deceleration characteristics (deceleration for each vehicle speed) in the second deceleration mode. Note that the curve L2-1 is the deceleration set when an operation to decrease the deceleration is performed, and defines a deceleration smaller than the deceleration in the first deceleration mode described above. The curve L2-2 is the deceleration set when an operation to increase the deceleration is performed once, and defines a deceleration larger than the deceleration in the first deceleration mode described above. The curve L2-3 is the deceleration set when an operation to increase the deceleration is performed twice, and defines a deceleration larger than the deceleration of the curve L2-2 described above.

[0028] The third deceleration mode is a mode that can be called the so-called coasting deceleration expansion mode (function), and is automatically executed based on the driving state of EV1. As already described in the "Background Art" section, when coasting downhill, a force due to gravitational acceleration acts in the direction of increasing vehicle speed. Therefore, in the coasting deceleration expansion mode (function), the braking force is controlled to suppress the increase in vehicle speed, and in the DMD control as the coasting deceleration expansion mode (function) for reflecting the driver's driving intention in the driving force and braking force, it is controlled to a deceleration different from (generally larger than) that in the first deceleration mode.

[0029] Such a coasting deceleration expansion function is executed to avoid giving the driver a sense of discomfort during coasting, so the deceleration is automatically set without the driver's manual operation. The deceleration is predetermined in design according to the gradient of the downhill slope and the vehicle speed at that time when coasting downhill. Also, in DMD control, based on the driver's past acceleration and deceleration operations, the deceleration during coasting is obtained and stored, and the stored deceleration is controlled during coasting. An example of the deceleration when coasting downhill is shown by curve L3 in Fig. 2. In the example shown here, the deceleration is larger than the deceleration set when the driver performs an operation to increase the deceleration once, and smaller than the deceleration set when the driver performs an operation to increase the deceleration twice. These deceleration characteristics shown in Fig. 2 are pre-stored in the ECU11 as a map, and based on input signals such as a signal detecting the vehicle speed and a signal based on the driver's manual operation, the regenerative braking force (negative torque associated with energy regeneration) of the electric motor 2 is controlled to be the deceleration read from the map.

[0030] In the embodiment of the present invention, the deceleration during coasting is set automatically or based on a manual operation as described above, and the control is executed by the ECU 11. That is, the ECU 11 includes each control unit shown in FIG. 3 as a functional configuration. First, the ECU 11 includes a current mode determination unit 13 that determines whether the deceleration mode set when the EV 1 is running is the above-described third deceleration mode. This determination can be made based on whether the current deceleration during coasting is the deceleration determined by the curve L3 shown in FIG. 2 described above, or whether control for setting the deceleration based on the curve L3 is being executed.

[0031] Further, the ECU 11 includes a manual deceleration detection unit 14 that detects that the driver has performed a manual operation to increase or decrease the deceleration while the deceleration during coasting is controlled in the third deceleration mode. This function is a function of detecting that a manual operation has been performed and the content of the operation (request) based on the output signal from the above-described select sensor 10 or the output signal from a shift mechanism (not shown).

[0032] Furthermore, the ECU 11 includes a deceleration transition instruction unit 15. When the manual deceleration detection unit 14 detects a change (increase or decrease) in the deceleration due to a manual operation, the deceleration transition instruction unit 15 instructs to change from the deceleration that has already been set at that time to the deceleration corresponding to the manual operation (deceleration request). For example, when the amount of change in the deceleration (increase amount and decrease amount) for each manual operation is determined in advance, the deceleration is changed by the amount determined by the manual operation. More specifically, the regenerative braking force of the electric motor 2 is changed. Also, when using the curves L2-1 to L2-3 used in the second deceleration mode shown in FIG. 2, the deceleration is changed to the deceleration (any one of the curves L2-1 to L2-3) closest to the current deceleration (curve L3) set by the third deceleration mode. And a torque control unit 16 for controlling the electric motor 2 via the inverter 3 is provided in the ECU 11 so as to achieve the deceleration instructed by the deceleration transition instruction unit 15.

[0033] Next, an example of the control executed in the embodiment of the present invention will be described. FIG. 4 is a flowchart for explaining an example of the control, and the control is executed by the ECU 11 described above in a state where the accelerator opening is zero (the driving demand amount is zero). In the control example shown in FIG. 4, first, it is determined whether there is a request to switch the deceleration level (step S1). This can be determined by whether the driver manually operates the above-described select lever 9 or a shift mechanism (not shown) and a signal associated therewith is output. If the determination in step S1 is negative, the routine of FIG. 4 is once terminated without performing any particular control. On the contrary, if the determination in step S1 is affirmative, the deceleration control mode is set to the above-described second deceleration mode (step S2). That is, a signal based on a manual operation for switching or selecting the deceleration is received, and the deceleration is switched to a state where it can be controlled based on the signal.

[0034] Next, it is determined whether the previously executed deceleration control mode (the deceleration control mode immediately before switching) is the normal mode (the above-described first deceleration mode) (step S3). If the determination in this step S3 is affirmative, it is determined whether the deceleration by the coasting deceleration expansion function is reflected, that is, whether the deceleration control by the above-described third deceleration mode is being executed (step S4). The functional means for executing this step S4 corresponds to the current mode determination unit in the embodiment of the present invention.

[0035] If the determination in this step S4 is affirmative, the deceleration is greater than the deceleration in the above-described first deceleration mode (normal mode). In that case, it is determined whether the manual operation for switching (or requesting) the deceleration is an operation in the direction of increasing the deceleration level (step S5). The functional means for executing this step S5 corresponds to the manual deceleration detection unit in the embodiment of the present invention.

[0036] If it is affirmatively determined in step S5, the current deceleration rate is increased by a predetermined amount based on the manual operation. As an example, when using the deceleration rate (preset deceleration rate) prepared in advance as the map in the second deceleration mode described above, among the preset deceleration rates greater than the current deceleration rate level, the minimum deceleration rate level is selected and set (step S6). That is, a deceleration rate greater than the current deceleration rate level and closest to the current deceleration rate level is selected.

[0037] Conversely, if it is negatively determined in step S5, that is, if an operation to reduce the deceleration rate level is being performed, the deceleration rate level is reduced by a predetermined amount based on the manual operation. As an example, when using the deceleration rate (preset deceleration rate) prepared in advance as the map in the second deceleration mode described above, among the preset deceleration rates smaller than the current deceleration rate level, the maximum deceleration rate level is selected and set (step S7). That is, a deceleration rate smaller than the current deceleration rate level and closest to the current deceleration rate level is selected.

[0038] The functional means for executing the control of steps S6 and S7 corresponds to the deceleration transition instruction unit in the embodiment of the present invention. And after executing either of steps S6 and S7, the routine shown in FIG. 4 is terminated once.

[0039] If it is negatively determined in step S3 because the mode of the immediately preceding deceleration control is not the normal mode, or if it is negatively determined in step S4 because the deceleration rate by the third deceleration mode is not set, in either case, it is determined whether the manual deceleration change operation is an operation to increase the deceleration rate level (step S8). This is the same determination as the determination in step S5 described above.

[0040] If a negative determination is made in step S3 or step S4, the currently set deceleration is the deceleration in the second deceleration mode described above. In other words, with reference to FIG. 2, it is the deceleration determined by any of the curves L2-1 to L2-3. Therefore, in this case, the deceleration control in the second deceleration mode will continue. That is, when a positive determination is made in step S8, the deceleration level is increased by "1" (deceleration level +1) (step S9). Then, the routine shown in FIG. 4 is terminated once. On the contrary, when a negative determination is made in step S8, that is, when an operation to reduce the deceleration is being performed, the deceleration level is decreased by "1" (deceleration level -1) (step S10). Then, the routine shown in FIG. 4 is terminated once. Note that the controls in steps S9 and S10 are such that when using the preset deceleration described above, the deceleration is set to the deceleration on the curve adjacent to the curve that defines the currently set deceleration among the curves L2-1 to L2-3.

[0041] Note that when a manual operation to increase the deceleration is performed while the maximum deceleration that can be selected by manual operation is set, the deceleration cannot be increased beyond the current value. Therefore, the request to increase the deceleration based on the manual operation is canceled. Similarly, when a manual operation to reduce the deceleration is performed while the minimum deceleration that can be selected by manual operation is set, the deceleration cannot be reduced beyond the current value. Therefore, the request to reduce the deceleration based on the manual operation is canceled.

[0042] As described above, in the embodiment described herein, when controlling the deceleration in the first deceleration mode (normal mode), and when once setting the deceleration based on a manual operation and controlling the deceleration in the second deceleration mode, the deceleration is switched from the deceleration determined in each deceleration mode to the other decelerations determined in each deceleration mode. On the other hand, when the third deceleration mode is being executed and the deceleration is automatically changed and set from the deceleration in the first deceleration mode, the deceleration based on the manual operation is set to increase or decrease from the current deceleration.

[0043] That is, in the second deceleration mode, for example, when manually operated once in the direction of reducing the deceleration, the deceleration is switched from the deceleration on the curve L1 in FIG. 2 to the deceleration on the curve L2-1. However, when the same manual operation is performed in a state where the deceleration is set by the coasting deceleration expansion function, the deceleration is switched to the deceleration on the curve L2-2. Therefore, even when a manual operation for changing the deceleration is performed during coasting control in the third deceleration mode, a situation where the deceleration suddenly decreases can be avoided, the drivability of the EV1 can be maintained well, and a sense of discomfort can be avoided.

[0044] Note that the present invention is not limited to the above-described embodiments. The mechanism for generating and changing the deceleration is not limited to the motor 2 as the driving power source described above. In a vehicle equipped with a transmission, the gear ratio in the transmission may be changed. Further, in a hybrid vehicle, the deceleration may be controlled by an electric motor that transmits the driving force to the wheels. Furthermore, the map for preliminarily determining the deceleration for controlling the deceleration is not limited to the characteristics shown in FIG. 2 described above, and a map having a larger number of characteristic lines may be used. In the above-described embodiments, the characteristic line in the normal mode is shown as a single curve. However, in a vehicle in which a normal normal mode and a power mode excellent in driving force (acceleration performance) can be selected as the driving mode, a plurality of characteristic lines for determining the deceleration during coasting may be provided according to the driving mode.

Explanation of Signs

[0045] 1 Electric vehicle (EV) 2 Motor 3 Inverter 4 Power storage device 5 Differential gear 6 Driving wheels 7 Accelerator pedal 8 Accelerator sensor 9 Select lever 10 Select sensor 11 Electronic control unit (ECU) 12 Sensors 13 Current mode determination unit 14 Manual deceleration detection unit 15 Deceleration transition instruction unit 16 Torque control unit

Claims

1. A vehicle deceleration control device capable of a first deceleration mode in which a deceleration during coasting with an acceleration requirement of zero is set to a predetermined deceleration, a second deceleration mode in which the deceleration is increased or decreased by a signal based on a manual operation of the driver, and a third deceleration mode in which a predetermined deceleration greater than the deceleration by the first deceleration mode is set based on a detection signal from a sensor that detects a driving state, a current mode determination unit that determines that the predetermined deceleration is set by the third deceleration mode, a manual deceleration detection unit that detects that the signal based on the manual operation of the driver has occurred in a state where it is determined that the predetermined deceleration is set by the third deceleration mode, a deceleration transition instruction unit that, when it is detected that the signal based on the manual operation of the driver has occurred in a state where it is determined that the predetermined deceleration is set by the third deceleration mode, sets a deceleration obtained by adding or subtracting the deceleration corresponding to the signal based on the manual operation of the driver to the predetermined deceleration, comprising, a plurality of decelerations for the second deceleration mode for transitioning from the predetermined deceleration set in the first deceleration mode are determined in advance when the signal based on the manual operation by the driver occurs, the deceleration transition instruction unit, when it is detected that the signal based on the manual operation of the driver has occurred in a state where it is determined that the predetermined deceleration is set by the third deceleration mode, transitions to the deceleration closest to the predetermined deceleration in the increasing or decreasing direction of the deceleration corresponding to the signal based on the manual operation of the driver among the decelerations for the second deceleration mode, and instructs to do so A vehicle deceleration control device characterized by this.

2. The vehicle deceleration control device according to claim 1, the vehicle includes an electric motor that outputs a negative torque that decelerates the vehicle by regenerating energy as a driving power source, Further comprising a torque control unit that controls the electric motor so as to generate a deceleration in the first deceleration mode to the third deceleration mode A vehicle deceleration control device characterized by the above

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