JP3456182B2 - Constant speed traveling device for hybrid vehicles - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a constant speed traveling device for a hybrid vehicle which drives a vehicle by an engine and a motor and controls the vehicle speed so as to maintain the vehicle speed at a target vehicle speed.

[0002]

2. Description of the Related Art Conventionally, there is a constant speed traveling device for controlling traveling by setting a set vehicle speed so that the vehicle speed becomes the set vehicle speed, which is mounted on many vehicles. In addition, it is necessary to decelerate when approaching the preceding vehicle while setting the constant speed traveling. Therefore, a constant-speed traveling device having an inter-vehicle distance control function, in which a forward-looking radar is mounted on the vehicle and, when a preceding vehicle is detected, the control shifts to control for maintaining the inter-vehicle distance to the preceding vehicle at a predetermined value Is also known.

It is preferable to mount a constant speed traveling device even in a hybrid vehicle equipped with both an engine and a motor. The constant speed traveling is often performed in a high speed traveling state such as 80 km / h or more. During such high speed traveling, an engine is used as its drive source. Figure 5
Fig. 3 shows the relationship between the vehicle speed and the required driving force of the drive source in the hybrid vehicle. In this way, the output of the motor is used when the vehicle speed is low.

[0004]

Here, in the inter-vehicle distance control, the preceding vehicle moves to another lane or deviates to the side road, and there is no preceding vehicle to be subject to the inter-vehicle distance control. When is released, the vehicle returns to constant speed running. In this case, the throttle opening is increased by electronic control to accelerate the vehicle. However, the driver may feel that the acceleration at this time is slow. This is because the driver recognizes early that the preceding vehicle is gone by blinking the blinker or starting a change in the vehicle traveling direction, and there is a control delay until the engine output changes in the throttle opening control by electronic control. Is thought to be the cause.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a constant speed traveling device capable of promptly accelerating when there is no demand for deceleration.

[0006] Incidentally, it is disclosed in Japanese Patent Laid-Open No. Hei 9-207 that the assist is provided by the output of the motor during the normal constant speed running.
It is described in Japanese Patent No. 622. However, this conventional example is merely a torque assist at the time of constant speed traveling, and the concept of temporarily assisting is not shown.

[0007]

According to the present invention, a vehicle can be driven by an engine and a motor, and feedback control is performed so as to maintain the vehicle speed at a set target vehicle speed, and a predetermined speed running control is performed. In the constant-speed traveling device for a hybrid vehicle, which performs the deceleration traveling control to control the engine output so that the constant-speed traveling control is stopped and the vehicle speed falls below the set target vehicle speed under the deceleration request condition,
When the predetermined deceleration request condition is canceled and the constant speed traveling control is restarted, the engine output is increased.
At the same time , torque assist is performed by the motor for a predetermined time. In addition, the motor-driven
The engine output will be
Engine eyes determined based on the difference between the standard vehicle speed and the current vehicle speed
It is preferable to set the time until the standard output.

As described above, according to the present invention, when the feedback control of the vehicle speed is restarted, the motor assists the torque. Since the output torque of the motor rises early, this provides sufficient acceleration. Also,
Since the torque assist is performed for a limited time, there is no problem such as battery exhaustion.

Further, it is preferable that the deceleration request condition is when it is detected that the inter-vehicle distance to the vehicle traveling ahead is reduced to a set value or less. When a preceding vehicle exists at the time of constant speed traveling, it is preferable that the following vehicle be maintained while maintaining the following distance from the preceding vehicle. Then, when the preceding vehicle disappears, the torque assist of the motor can be used to accelerate quickly.

Further, according to the present invention, the vehicle can be driven by the engine and the motor, and the constant speed running control is performed so that the vehicle speed is feedback-controlled so as to be maintained at the set target vehicle speed. Then, in the constant-speed traveling device of the hybrid vehicle for stopping the constant-speed traveling control and performing the deceleration traveling control for controlling the engine output so that the vehicle speed becomes lower than the set target vehicle speed,
Has an input clutch for turning on and off the transmission of power is provided between the engine and the motor, the deceleration control when the motor and the engine to regularly on the input clutch
To rotate .

As described above, the engine is always rotating during the deceleration control. Therefore, when the deceleration traveling control is canceled and the constant speed traveling control is returned to, the engine can be ignited to generate torque immediately, and quick acceleration can be obtained. In addition, the engine can be used as a load during deceleration control, and effective deceleration can be performed. During normal driving or constant speed driving, the motor load can be reduced by disconnecting the engine during motor driving, and the input clutch can be turned off during deceleration. The energy recovery rate can be increased by regenerative braking of.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention (hereinafter referred to as embodiments) will be described below with reference to the drawings.

[First Embodiment] FIG. 1 shows a block diagram of a hybrid vehicle according to the first embodiment. The output shaft of the engine 1 is connected to the motor generator 2, the output shaft of the motor generator 2 is connected to the torque converter 3, and the output shaft of the torque converter 3 is connected to the automatic transmission 4. That is, the power of the engine 1 and the power of the motor generator 2 can be output to the automatic transmission 4 via the torque converter 3. Then, the output of the automatic transmission 4 is transmitted to the wheels.

The engine 1 is a device that outputs power by burning fuel, and includes a gasoline engine, a diesel engine, and an engine that burns a gas fuel such as liquefied petroleum gas or natural gas. The motor generator 2 has both a motor function of converting electrical energy into kinetic energy such as rotary motion and outputting the same, and a power generation function of converting transmitted power energy into electrical energy. The torque converter 3 appropriately transmits the torque of the driving member to the driven member via the fluid. The automatic transmission 4 is a device that includes a gear transmission unit and a hydraulic control unit, and is capable of automatically changing the ratio of the input rotation speed and the output rotation speed (gear ratio) automatically. A continuously variable transmission capable of continuously changing the machine and the gear ratio is adopted.

FIG. 2 shows a system configuration diagram of this embodiment. A battery 6 is connected to the motor generator 2 via an inverter 5. The inverter 5 turns on / off a plurality of switching elements inside thereof to turn on / off the battery 6
The direct-current power from the converter is converted into a predetermined alternating-current power and supplied to the motor generator 2, and the alternating-current generated power in the motor generator 2 is supplied to the battery 6 as the direct-current power. A controller 7 is provided to control such an operation. That is, the controller 7 controls the inverter 5 based on the accelerator operation or the like to control the output torque and the regenerative braking force of the motor generator 2. In the motor generator 2 of this embodiment, the input side is connected to the output shaft of the output of the engine 1, and the torque of the output shaft of the motor generator 2 is the sum of the output of the engine 1 and the output of the motor generator 2. Has become. Then, the output torque is transmitted to the wheels via the torque converter 3 and the automatic transmission 4 as described above.

Further, an ECU 8 is connected to the engine 1, and the output of the engine 1 is controlled by this ECU 8. The ECU 8 is composed of a microcomputer, and is supplied with detection signals such as a vehicle speed signal, an accelerator opening signal, an SOC (state of charge) signal, and a brake signal. Then, the ECU 8 controls the drive of the engine 1 based on these detection signals, and also controls the slip ratio of the torque converter 3, the gear ratio of the automatic transmission 4, and the like. The ECU 8 controls the output of the motor generator 2 via the controller 7 so that the SOC of the battery 6 falls within a predetermined range.

Here, in the present embodiment, the ECU 8 also performs control for constant speed traveling. That is, this ECU 8
Receives the vehicle speed set signal, takes in the set vehicle speed, and thereafter adjusts the throttle opening to feedback control the output of the engine 1 so that the supplied vehicle speed signal approaches the set vehicle speed.

Further, the ECU 8 cancels the above-mentioned feedback control when the preceding vehicle is present within a predetermined range based on the following distance information from the preceding vehicle from the radar using the laser or millimeter wave. The follow-up traveling control is performed by controlling the output of the engine 1 so that the inter-vehicle distance becomes constant. Then, when the preceding vehicle disappears due to a lane change, turning to the left or right, deviation to the road, etc., it automatically returns to the feedback control (constant speed control) to the set vehicle speed.

Here, the processing during constant speed traveling in this embodiment will be described with reference to FIGS. First, input signals from various sensors are taken in (S11). next,
It is determined whether or not the vehicle is traveling at a constant speed (S12). The constant speed traveling in the determination of S12 is a concept that also includes traveling control for following the preceding vehicle. If YES in the determination in S12, it is determined whether the inter-vehicle distance control (following control) with the preceding vehicle was performed until the previous determination (S13). If YES in this determination, it is determined whether or not there is no preceding vehicle this time (S
14). If YES in this determination, it is determined whether there is an acceleration request (S15). This is because even if the following vehicle is controlled to follow the preceding vehicle, if the preceding vehicle has a substantially set vehicle speed, no acceleration request is made.

If the determination in S15 is also YES, the acceleration control using the motor generator 2 according to this embodiment is started. If the determination in S12 to S15 is NO, the acceleration control is unnecessary and the process ends.

If YES in S15, the output torque to be increased in response to the acceleration request is calculated from the acceleration request (S16). That is, the output torque to be increased is calculated according to the difference between the current vehicle speed and the set vehicle speed. Then, based on the calculated output torque to be increased, the output of the motor generator 2 is controlled (S17), and the throttle is opened to start the control of increasing the output of the engine 1 (S18).

Here, the output torque of the motor generator 2 immediately rises with the output up command. Therefore, in the present embodiment, the time T1 for the engine 1 to reach the target output torque based on the output torque increase command.
Is calculated and calculated, and the acceleration torque is assisted by the output torque from the motor generator 2 only for the time T1.

As shown in FIG. 3, when it is detected that the preceding vehicle is gone and the next processing loop is entered, the motor generator 2 is drive-controlled and the throttle opening is increased. The output torque of No. 2 is set to about 50% of the increase in torque required when the vehicle finally travels at the target vehicle speed. Then, the motor generator 2 outputs the maximum output with the output of the engine 1 in about half the time T1 at which the target vehicle speed can be maintained, and returns the output to zero after the time T1 has elapsed.

That is, the elapsed time T from the start of acceleration control in S17 is compared with the time T1 required for acceleration (S19),
When T1 is reached, the normal throttle control for constant speed traveling is returned (S20), and the output of the motor generator 2 is stopped (S21). As a result, the constant speed traveling returns to the feedback control based on the comparison between the detected vehicle speed and the set vehicle speed.

As described above, in the present embodiment, when there is no preceding vehicle, the motor generator 2 is used only for a predetermined period of time, for example, until the output torque of the engine can maintain the set vehicle speed for acceleration. To do. Therefore, it is possible to perform acceleration suitable for the driver's feeling.

In the above description, the case where the normal constant-speed traveling cannot be performed due to the presence of the preceding vehicle, and the deceleration request condition is canceled thereafter has been described. However, the deceleration request condition is not limited to this and may be another case. For example, when the constant speed traveling state is not released by the brake operation, the brake operation may be performed. That is, even when the preceding vehicle is not present in front of the predetermined vehicle, the driver may operate the brake to decelerate at his / her own discretion. And when the brake operation is lost after that,
The configuration of the present embodiment is preferable in the case of quickly moving to constant speed traveling.

[Second Embodiment] FIG. 6 shows an input clutch 10 according to a second embodiment. In this way, the input clutch 10 is arranged between the engine 1 and the motor generator 2 and turns on / off the transmission of power between them.

This input clutch 10 is shown as E in FIG.
It is controlled by the CU 8, which will be described with reference to FIG.

First, the ECU 8 takes in input signals from various sensors (S31). Next, it is determined whether or not the vehicle is traveling at a constant speed (S32). The constant speed running in the determination of S32 is
Similar to the first embodiment, it is a concept that includes follow-up traveling control to the preceding vehicle. If YES in the determination of S32, it is determined whether the inter-vehicle distance control (following control) with the preceding vehicle was performed until the previous determination (S33).

If YES in this determination, the input clutch 10 is always turned on (S34). On the other hand, S3
If NO in 2 or S33, ON / OFF of the input clutch 10 is controlled for each vehicle traveling condition (S3).
5).

Here, the input clutch 10 in S35
The on / off control of will be described. If it is not the follow-up running in S35, the ECU 8 controls the on / off of the input clutch 10 to disconnect the engine 1 from the motor generator 2 when unnecessary.

That is, in the operating state of the motor generator 2 shown in FIG. 5, the motor generator 2 is used as a drive source in a state where the required drive is large at a constant speed. in this case,
Turn off the input clutch 10 and disconnect the engine 1,
The drive is stopped. As a result, the engine 1 is completely stopped and the output of the motor generator 2 is
It is effectively used as a wheel driving force.

Further, even in the regenerative braking state shown in FIG. 5, the input clutch 10 is turned off. As a result, all the energy obtained by the deceleration is used for the power generation by the motor generator 2, and the battery can be charged with this to effectively recover the energy.

On the other hand, in the case of the follow-up control, the input clutch 10 is always turned on in S34. Therefore, the input clutch 10 is turned on even in the vehicle driving state in which the motor generator 2 is turned on and the engine 1 is turned off, and the engine 1 is rotated together with the motor generator 2 in an integrated manner. Therefore, when the vehicle ahead is gone and the vehicle accelerates, the engine 1 ignites the torque immediately by igniting the engine, and the driving force of the engine 1 can be used to achieve rapid acceleration.

Further, since the engine 1 is rotating together, when the vehicle in front decelerates, etc.
Can be used as a load to generate a deceleration force. Therefore, not only the deceleration force due to the regenerative braking of the motor generator 2 but also the deceleration force can be obtained using the engine 1.
The deceleration response can be improved.

As described above, according to this embodiment, the input clutch 10 is turned on and the engine 1 is rotated together with the motor generator 2 during the follow-up control. 1 can be started quickly and the deceleration performance can be improved.

[0037]

As described above, according to the present invention,
When the engine output feedback control is restarted, the motor assists the torque. Since the output torque of the motor rises early, this provides sufficient acceleration. Further, since the torque assist is performed for a limited time, there is no problem such as battery exhaustion.

Further, since the input clutch is connected during the deceleration traveling control, the deceleration performance at that time and the acceleration performance when returning to the constant speed traveling can be improved.

[Brief description of drawings]

FIG. 1 is a configuration block diagram of a hybrid vehicle according to a first embodiment.

FIG. 2 is a system block diagram of the hybrid vehicle.

FIG. 3 is a flowchart illustrating an operation when canceling a deceleration request condition.

FIG. 4 is a timing chart for explaining an operation when canceling a deceleration request condition.

FIG. 5 is a diagram showing a relationship between a vehicle speed, a required driving force, and a driving source.

FIG. 6 is a diagram showing a partial configuration of a second embodiment.

FIG. 7 is a flowchart illustrating the operation of the second embodiment.

[Explanation of symbols]

1 engine, 2 motor generator, 3 torque converter, 4 automatic transmission, 5 inverter, 6 battery, 7 controller, 8 ECU, 10 input clutch.

Continuation of front page (51) Int.Cl. ⁷ Identification symbol FI B60K 6/04 730 B60K 6/04 730 31/00 31/00 Z F02D 29/02 F02D 29/02 D 301 301D (72) Inventor Masaya Amano 1 Toyota Town, Toyota-shi, Aichi Toyota Motor Co., Ltd. (56) Reference JP 58-203524 (JP, A) JP 5-272349 (JP, A) JP 5-231202 (JP, A) JP-A-2-41690 (JP, A) JP-A-61-61926 (JP, A) JP-A-8-207600 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) ) B60L 11/14 B60K 31/00 F02D 29/02 F02D 29/02 301 B60K 6/02-6/04

Claims (4)

(57) [Claims] 1. A constant-speed running control is performed in which a vehicle can be driven by an engine and a motor, and feedback control is performed so as to maintain the vehicle speed at a set target vehicle speed, and the constant speed is maintained under a predetermined deceleration request condition. In a constant speed traveling device for a hybrid vehicle, which performs a deceleration traveling control for controlling engine output so as to stop traveling control and reduce a vehicle speed from the set target vehicle speed, the predetermined deceleration request condition is released, When the drive control is restarted and the engine output is increased
At the same time , it is a constant-speed running device for hybrid vehicles that performs torque assist by a motor for a predetermined time. 2. The constant speed traveling device for a hybrid vehicle according to claim 1, wherein the deceleration request condition is when it is detected that the inter-vehicle distance from the vehicle traveling ahead has decreased below a set value. 3. The device according to claim 1 or 2.
Te, Torukuashisu by the motor at the time of the constant-speed running Resume
For a predetermined period of time when the engine is
Reaching the target output of the engine, which is determined based on the difference in vehicle speed
The constant-speed running equipment of a hybrid vehicle set to the time until
Place 4. A constant speed running control for feedback control so that a vehicle can be driven by an engine and a motor and a vehicle speed is maintained at a set target vehicle speed, and the constant speed is maintained under a predetermined deceleration request condition. A constant-speed traveling device for a hybrid vehicle, which performs deceleration traveling control for controlling engine output so as to stop traveling control so that the vehicle speed becomes lower than the set target vehicle speed, wherein transmission of power is provided between the engine and a motor. has an input clutch for turning on and off, the deceleration control at the time of the in regularly on the input clutch hybrid vehicle cruise device for rotating the motor and the engine.