JP2001322540A - Vehicle deceleration control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular deceleration control device capable of imparting proper deceleration in a vehicle having a regenerative brake device. SOLUTION: A brake computer 20 perfoms control for imparting deceleration to the vehicle according to an operation quantity of an accelerator pedal obtained from an accelerator sensor 32, and imparts proper deceleration by preferentially operating the regenerative brake device for charging a battery 16 by recovering kinetic energy of the vehicle as electric power by a motor 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deceleration control device for a vehicle which detects an accelerator operation state and adds deceleration to the vehicle in accordance with the operation state, and more particularly to a combination of a regenerative braking device and a friction braking device. The present invention relates to a vehicle deceleration control device for adding deceleration to a vehicle.

[0002]

2. Description of the Related Art Hitherto, a deceleration control device has been proposed in which a braking force is applied when a driver releases the accelerator pedal to decelerate the vehicle. JP-A-9-
The technology disclosed in Japanese Patent No. 95222 is one of them, and when the accelerator pedal is in a no-load region,
The braking force is applied to the main brake system via the deceleration control device.

[0003] By adding such a deceleration control device, it is not necessary to frequently operate the brake pedal when the vehicle is gradually accelerated or decelerated, and it is possible to enhance the deceleration response and realize an easy drive. Have been.

[0004]

In an electric vehicle, a hybrid vehicle, or the like, regenerative braking is performed in which a driving motor functions as a generator to recover kinetic energy of the vehicle as electric power to perform braking. The publication does not disclose any additional deceleration when such a regenerative braking device is used.

Accordingly, an object of the present invention is to provide a vehicle deceleration control device capable of adding an appropriate deceleration to a vehicle having a regenerative braking device.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a vehicle deceleration control device according to the present invention comprises an accelerator operation state detecting means for detecting an accelerator operation state of a driver, and an accelerator operation state detecting means. A deceleration control device for adding deceleration to the vehicle according to the result. The deceleration control device includes a regenerative braking device and a friction braking device. And a controller for controlling the deceleration to be applied by the friction braking device according to the deceleration obtained by the above.

According to the present invention, the deceleration applied by the friction braking device is controlled in accordance with the deceleration obtained by the regenerative braking device, so that a stable deceleration can be added by the deceleration adding means and the regenerative braking device can be added. It is possible to secure the energy recovery efficiency at the same time.

[0008] It is preferable that the control unit performs control to stop the operation of the friction braking device when a required deceleration can be obtained by the regenerative braking device. By performing braking only with the regenerative braking device, sufficient energy recovery can be performed.

Alternatively, the control unit sets a target deceleration to be added according to the driving state of the vehicle, and adds the target deceleration to the friction braking device based on a deviation between the target deceleration and the deceleration obtained by operating the regenerative braking device. It is preferable to control the braking force to be applied. Only when the deceleration cannot be sufficiently obtained with the regenerative braking device, the target deceleration can be reliably obtained by using the friction braking device in an auxiliary manner, and energy can be efficiently recovered.

[0010]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In order to facilitate understanding of the description, the same constituent elements are denoted by the same reference numerals as much as possible in each drawing, and redundant description will be omitted.

FIG. 1 is a block diagram showing a configuration of a control system of a vehicle equipped with a vehicle deceleration control device according to the present invention. FIG. 2 is a schematic configuration diagram showing a braking system and a drive system of the vehicle. It is.

First, the configuration of the vehicle will be described with reference to FIG. This vehicle is a hybrid vehicle having an engine 11 and a motor 12 as drive sources, and a power split mechanism in which an engine 11 and a motor 12 as drive sources and a generator 13 as a generator have a continuously variable transmission mechanism using planetary gears. The output shaft (drive shaft) of the power split device 14 is transmitted to the front wheels FR and FL as drive wheels via a differential gear 17. The motor 12 and the generator 13 are of an AC synchronous type, and are electrically connected to the inverter 15. The inverter 15 is further electrically connected to a battery.

On the other hand, a hydraulic brake 23 as a friction braking device is installed on each of the wheels FR, FL, RR, RL. A brake hydraulic power source 21 composed of an electric motor or an accumulator, and a hydraulic pressure adjusting unit 22 that adjusts an operating hydraulic pressure supplied to each hydraulic brake 23 based on the hydraulic pressure of the brake hydraulic power source 21 are provided.

The control unit of the vehicle deceleration control device according to the present invention comprises a brake computer 20 shown in FIG. 1, a hybrid ECU 10, a motor ECU 101, a battery ECU 102, and an engine ECU 103. Brake computer 20 for controlling the friction braking device
Is for controlling the brake hydraulic pressure source 21 and the hydraulic pressure adjusting unit 22, is provided on a brake pedal, and is supplied with an output of a brake sensor 30 for detecting an operation amount of the brake pedal.

The hybrid ECU mainly controls a drive system, and has a vehicle speed sensor 3 for detecting a vehicle speed V.
1. An output signal of an accelerator sensor 32, which is installed on an accelerator pedal and detects its opening, is supplied to the motor EC
U101, battery ECU102, engine ECU1
03, and supplies information necessary for the control with the brake computer 20 to perform control in a coordinated manner.

The motor ECU 101 includes an inverter 15
To control the operation of the motor 12 and the generator 13. The battery ECU 102 controls charging and discharging of the battery 16. The engine ECU 103 controls the operation of the engine 11.

The operation of the vehicle during braking will be described. When a brake pedal (not shown) is depressed,
The operation amount of the brake pedal is supplied from the brake sensor 30 to the brake computer 20. The brake computer 20 issues a regeneration request to the hybrid ECU 10.

The hybrid ECU 10 receives this,
By controlling the inverter 15 via the motor ECU 101, the motor 12 is driven by the rotational force of the drive wheels FL and FR connected via the differential gear 17 to generate electric power. Charge. A braking force is obtained by the resistance of the motor 12 during the power generation. If this braking force is insufficient for the required braking force calculated from the operation amount of the brake pedal 31, the brake computer 20 activates the hydraulic adjustment unit 22 to adjust the friction braking force applied to each brake 23 to perform braking. Do.

FIG. 3 is a view for explaining the operation amount of the accelerator pedal. In this vehicle, during a period from when the accelerator pedal is fully opened to when the accelerator pedal is depressed to θa0, that is, when the accelerator opening θa is less than θa0, the vehicle is in a no-load region (a region where the output of the engine 11 is minimized or the engine is stopped). Is set. When the accelerator pedal is depressed beyond the accelerator opening θa0, the load is set in the load range.

In the load range, the hybrid ECU 10
The engine ECU 103 is controlled to increase the engine speed, or the motor ECU 102 is controlled to increase the output speed of the motor 12, thereby increasing the speed of the drive shaft to accelerate the vehicle.

In the no-load region, when the engine 11 is operating, the engine speed is reduced to reduce the output of the engine 11 to a minimum output (idling) state, thereby reducing the rotation speed of the drive shaft, thereby decelerating the vehicle. At this time, since the engine 11 and the drive shaft are not directly connected, a deceleration force generated by a resistance force accompanying a decrease in the engine speed of the engine 11, that is, a so-called engine braking effect is insufficient. Performs engine brake assist (EBA) control to add deceleration force. When the engine 11 is not operating, a deceleration force equivalent to the engine brake is obtained by this EBA control. Hereinafter, this EBA control will be specifically described.

FIG. 4 is a control flowchart of the EBA control. This control is performed by the brake computer 2 of the vehicle.
0 is turned on, and is repeatedly executed at a predetermined timing. However, if it is determined that the brake pedal is operated by the output of the brake sensor 30, the normal braking operation takes precedence. Is skipped.

In step S1, the brake computer 20 and the hybrid ECU 10 read the respective vehicle state quantities. The vehicle state quantity includes the vehicle speed V sent from the vehicle speed sensor 31, the accelerator opening degree θa sent from the accelerator sensor 32, and the like.

In step S2, the brake computer 20 calculates the target additional deceleration EBA (t) from the obtained vehicle state quantity.
Is calculated. Next, in step S3, the battery EC
U102 determines the state of charge of the battery 16. If the battery 16 is not fully charged, the process proceeds to step S4, and the brake computer 20
A regenerative braking request is sent to the CU 10 and the hybrid E
The CU 10 controls the inverter 15 via the motor ECU 101 to obtain the required additional deceleration EBA (t),
Operate the regenerative brake. That is, the kinetic energy of the vehicle is recovered as electric power by causing the motor 12 to function as a generator, and the battery 16 is charged.

On the other hand, when the battery 16 is fully charged, the process proceeds to step S5, where the brake computer 2
Numeral 0 controls the hydraulic adjustment unit 22 to control the braking force applied by each hydraulic brake 23, and obtains the required additional deceleration EBA (t).

As described above, when the accelerator opening θa is less than θa0 (no-load range), the regenerative brake is operated when the regenerative braking device is operable, and the inoperable battery 16 is fully charged. Since the deceleration is sometimes added by operating the hydraulic brake, a deceleration force equivalent to the engine brake can be easily obtained. Therefore, the slow deceleration can be adjusted only by operating the accelerator pedal, and the regenerative brake is operated with priority, so that the friction braking device can be prevented from being worn, and the energy recovery efficiency is improved.

FIG. 5 is a control flowchart of another EBA control. Steps S11 to S13 are the same as steps S1 to S3 of the control shown in FIG.

If it is determined in step S13 that the battery 16 is not fully charged, the process proceeds to step S14, and the brake computer 20
10 sends a regenerative braking request to the hybrid ECU
Reference numeral 10 controls the inverter 15 via the motor ECU 101 so as to obtain the required additional deceleration EBA (t), and operates the regenerative brake. That is, the kinetic energy of the vehicle is recovered as electric power by causing the motor 12 to function as a generator, and the battery 16 is charged. This is equivalent to step S4.

On the other hand, when the battery 16 is fully charged, step S14 is skipped. In any case, the process proceeds to step S15 to determine whether the additional deceleration Gk obtained by the regenerative braking operation has reached the target additional deceleration EBA (t). This additional deceleration Gk can be determined from the power obtained by power generation.

If the target additional deceleration EBA (t) has been obtained by the regenerative braking, the subsequent processing is skipped and the processing ends. On the other hand, when the additional deceleration Gk obtained by the operation of the regenerative braking is lower than the target additional deceleration EBA (t), the brake computer 20 controls the hydraulic pressure adjusting unit 22 to apply the braking force applied by each hydraulic brake 23. Required additional deceleration EBA that was insufficient with regenerative braking
(t) is obtained. The target additional deceleration EBA (t) is obtained by further adding the deceleration for (EBA (t) -Gk).

As described above, the regenerative brake is operated with priority, and if the additional deceleration is insufficient with the regenerative brake, the deceleration is added by operating the hydraulic brake as an auxiliary. Can be reliably obtained. Therefore, the slow deceleration can be adjusted only by operating the accelerator pedal. In addition, since the regenerative brake is operated with priority, the wear of the friction braking device can be prevented,
In addition, energy recovery efficiency is improved.

Although the embodiment described above is applied to a hybrid vehicle, it is applicable to a vehicle equipped with both a regenerative braking device and a friction braking device as a braking device in addition to an electric vehicle and a fuel cell vehicle. Can be suitably applied. Further, the friction braking device is not limited to the above-described hydraulic brake, and various types of friction braking devices such as an electromagnetic type and a pneumatic type can be used.

[0033]

As described above, according to the present invention, the deceleration is added by preferentially operating the regenerative braking device in accordance with the operation of the accelerator pedal, so that the deceleration force equivalent to the engine brake can be easily obtained. While being able to
Energy recovery efficiency can be improved, and wear of the friction braking device can be prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a control system of a vehicle equipped with a vehicle deceleration control device according to the present invention.

FIG. 2 is a schematic configuration diagram illustrating a braking system and a driving system of the vehicle of FIG.

FIG. 3 is a diagram illustrating an operation amount of an accelerator pedal.

FIG. 4 is a flowchart of EBA control in the apparatus of FIG. 1;

FIG. 5 is a flowchart of EBA control different from FIG. 4;

[Explanation of symbols]

10 hybrid ECU, 11 engine, 12 motor, 13 generator, 14 power split mechanism,
15: Inverter, 16: Battery, 17: Differential gear, 20: Brake computer, 21
... Brake hydraulic pressure source, 22 ... Hydraulic adjustment unit, 23 ... Hydraulic brake, 30 ... Brake sensor, 31 ... Vehicle speed sensor,
... accelerator sensor, 101 ... motor ECU, 102 ...
Battery ECU, 103 ... Engine ECU.

Continued on the front page F term (reference) 3D046 CC02 CC06 EE01 HH05 HH26 5H115 PA08 PA12 PA15 PC06 PG04 PI16 PI24 PI29 PI30 PO02 PO06 PO17 PU08 PU24 PU25 PV09 QE10 QI04 QI07 QI08 QI09 QI12 QI14 QN02 RB08 SE04 TO02 TO23 TB01

Claims (3)

[Claims] 1. A vehicle comprising: an accelerator operation state detecting means for detecting a driver's accelerator operation state; and a deceleration adding means for adding deceleration to the vehicle in accordance with a result of detection by the accelerator operation state detecting means. In the deceleration control device, the deceleration adding means includes a regenerative braking device and a friction braking device, and controls a deceleration added by the friction braking device according to a deceleration obtained by the regenerative braking device. A vehicle deceleration control device including a control unit. 2. The deceleration control device for a vehicle according to claim 1, wherein the control unit controls to stop the operation of the friction braking device when a required deceleration is obtained by the regenerative braking device. 3. The control unit sets a target deceleration to be added according to a driving state of the vehicle, and sets the friction braking based on a deviation between the target deceleration and a deceleration obtained by operating a regenerative braking device. The deceleration control device for a vehicle according to claim 1, wherein the braking force applied by the device is controlled.