JP2005112021A - Vehicular start control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular start control device extending a lifetime of a clutch by reducing absorption energy of the clutch when a vehicle is started. <P>SOLUTION: In a clutch stroke control means of an ECU for AMT and an engine output control means of an engine ECU, the target torque is set according to the accelerator opening by the step-in quantity of an accelerator pedal by using a target torque setting means (B1), the set target torque is set with a temporary delay (B2 and B6), the clutch stroke is set by using the target torque set with the temporary delay (B4), and the engine speed is also set (B7). The clutch stroke and fuel injection are controlled by using the PID control so as to realize these set target values, and the clutch is coupled when a vehicle is started. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vehicle start control device that automatically connects and disconnects a clutch to start the vehicle, and is suitable for, for example, a mechanical automatic transmission.

  For large vehicles such as buses and trucks, an automatic clutch device that can automatically connect and disconnect the clutch and a gear stage are automatically selected for a mechanical transmission that has the same structure as a manual transmission that is inexpensive and fuel efficient. A combination of automatic transmission and the like. This is called a mechanical automatic transmission (hereinafter abbreviated as AMT). With the above-described configuration, the clutch can be automatically connected and disconnected in accordance with the timing of the shift, and the shift can be automatically performed. .

  In the above AMT, control is performed so that the clutch is automatically engaged and disengaged not only at the time of shifting but also at the time of starting and stopping. For example, at the time of starting, the accelerator pedal is depressed, the accelerator is turned on, and the engine speed If the engine speed is greater than the predetermined speed, the clutch is automatically controlled to be engaged.When the engine is stopped, the accelerator pedal is not depressed, the accelerator is turned off, and the engine speed is less than the predetermined speed. Control is performed so that the clutch is automatically disengaged, and control at start and stop is performed. When starting, the fuel injection amount is injected into the engine according to the accelerator opening (the amount of depression of the accelerator pedal), the engine speed increases, and the clutch automatically engages with the engine speed increase. Connected. In addition, when the load on the engine is large and the engine speed is reduced as a result of the clutch being connected, control is also performed to disconnect the clutch again in order to avoid engine stop.

Japanese Patent Laid-Open No. 10-325422

  The absorbed energy of the clutch when the clutch is connected is defined by an integral value of {(engine speed−clutch speed) × clutch transmission torque}. In the conventional automatic clutch device, the clutch connection is started after the engine speed has increased to some extent, so that the clutch is engaged. Therefore, compared to the manual clutch device that is manually operated by the driver, When the clutch is engaged, the engine speed increases and the absorbed energy of the clutch also increases. Therefore, it is highly likely that the life of the clutch will be shorter in the automatic clutch device than in the manual clutch device.

  Further, the engine speed at the start is determined simply by the fuel injection amount corresponding to the accelerator opening. Therefore, when the accelerator pedal is stepped on suddenly, the fuel injection amount is controlled without taking into account other operating conditions (for example, torque transmitted to the clutch, etc.), the engine speed increases rapidly, and Since the clutch is also suddenly connected, the energy absorbed by the clutch is still large, which may shorten the life of the clutch.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a vehicle start control device that can reduce the absorbed energy of the clutch at the time of start and extend the life of the clutch.

A vehicle start control device according to claim 1 of the present invention for solving the above-described problems is provided.
A clutch for connecting and disconnecting the transmission torque from the vehicle engine to the transmission;
Clutch stroke control means for controlling the stroke amount of the clutch connection;
An accelerator opening detecting means for detecting an accelerator opening corresponding to the amount of depression of the accelerator pedal;
Fuel supply means for controlling the fuel injection amount and supplying fuel to the engine;
Engine output control means for controlling the fuel supply means to control the output torque of the engine.
When the vehicle starts,
Target torque setting means for setting a target torque according to the accelerator opening detected by the accelerator opening detection means;
A transmission torque setting means for setting the transmission torque of the clutch according to the target torque set by the target torque setting means;
Using engine torque setting means for setting the output torque of the engine according to the target torque set by the target torque setting means,
The engine output control means controls the fuel injection amount that becomes the engine output torque set by the engine torque setting means,
The clutch stroke control means sets the clutch stroke according to the clutch transmission torque set by the transmission torque setting means, controls the clutch stroke amount to be the set clutch stroke, and performs the clutch connecting operation.

  In other words, when the accelerator pedal is stepped on at the time of starting, a target torque serving as an index of control of the present invention is set according to the amount of depression, and the engine torque is increased so as to follow the target torque, The stroke amount of the clutch is controlled so that the clutch transmission torque follows the target torque, and finally the vehicle is started by completely connecting the clutch.

A vehicle start control device according to claim 2 of the present invention for solving the above-mentioned problems is provided.
In the vehicle start control device,
The transmission torque setting means has a temporary delay means that uses the target torque set by the target torque setting means as a transmission torque with a temporary delay,
The clutch stroke control means sets a clutch stroke according to the set temporary delay transmission torque, controls the clutch stroke amount to be the set clutch stroke, and performs the clutch connecting operation.

A vehicle start control device according to claim 3 of the present invention for solving the above-described problems is provided.
In the vehicle start control device,
The transmission torque setting means has coefficient integration means for setting the set temporary transmission torque to a transmission torque obtained by integrating a predetermined coefficient of 1 or less,
The clutch stroke control means sets the clutch stroke according to the transmission torque integrated with the predetermined coefficient, controls the stroke amount of the clutch that becomes the set clutch stroke, and performs the clutch connecting operation.

A vehicle start control device according to claim 4 of the present invention for solving the above-described problems is provided.
In the vehicle start control device,
The engine torque setting means has a temporary delay setting means that uses the target torque set by the target torque setting means as an output torque of the engine having a temporary delay,
The engine output control means sets an engine speed according to the set engine output torque with a temporary delay, and controls the fuel injection amount at which the engine speed is set.

A vehicle start control device according to claim 5 of the present invention for solving the above-mentioned problems is provided.
In the vehicle start control device,
A clutch stroke detecting means for detecting the clutch stroke amount;
The clutch stroke control means controls the stroke amount by PID control based on the deviation between the set engine speed and the actual engine speed.

A vehicle start control device according to claim 6 of the present invention for solving the above-mentioned problems is provided.
In the vehicle start control device,
An engine speed detecting means for detecting the engine speed;
The engine output control means controls the fuel injection amount by PID control based on a deviation between the set engine speed and the actual engine speed detected by the engine speed detecting means.

  According to the present invention, the target torque at the time of starting is determined according to the accelerator opening, and the clutch stroke and the fuel injection amount are controlled using the target torque as a control index, so that a sense of acceleration according to the driver's intention is obtained. It is done. Further, since the engine speed is controlled to be the target speed, the absorbed energy of the clutch can be reduced and the clutch life can be extended.

  In an automatic mechanical transmission (AMT) having an automatic clutch device, not only at the time of shifting, but also at the time of starting and stopping, a clutch connecting / disconnecting operation is automatically performed. Conventionally, the fuel injection amount is simply determined according to the amount of accelerator pedal depression (accelerator opening) at the time of starting, and when the engine speed increases, the clutch is automatically connected to start the vehicle. I was in control. However, in the vehicle start control device according to the present invention, first, a target torque is set according to the amount of depression of the accelerator pedal (accelerator opening) at the time of start, and according to the set target torque, the clutch stroke, The fuel injection amount is determined, the clutch stroke and the fuel injection amount are controlled, the clutch is automatically connected, and the starting operation of the vehicle is controlled. The main features of the vehicle start control device according to the present invention will be described below.

(1) In order to obtain an acceleration feeling according to the driver's intention, a target torque is determined according to the accelerator opening. Specifically, the target torque corresponding to the accelerator opening is determined from the map data of the target torque and the accelerator opening.
(2) Avoid sudden changes in the target torque due to a temporary delay so that sudden acceleration of the accelerator pedal does not cause a sudden start.
(3) The base clutch stroke is obtained from the target torque, and the clutch stroke is further PID-controlled with respect to the base clutch stroke so that the engine speed does not increase unnecessarily.
(4) The engine fuel injection amount is instructed so that the engine torque becomes the target torque.
Further, the base target engine speed is obtained from the target torque, and the fuel injection amount is further PID controlled with respect to the base target engine speed so that the engine speed does not increase unnecessarily.

  Several embodiments of the vehicle start control device according to the present invention having the above features will be described below with reference to FIGS.

  FIG. 1 is a schematic diagram showing an example of an embodiment of a vehicle start control device according to the present invention.

  The vehicle start control device according to the present invention is used in an automatic transmission of a vehicle. As shown in FIG. 1, the automatic transmission of a vehicle mainly includes a torque connection / disconnection clutch mechanism (hereinafter referred to as a clutch) 1 having a dry single-plate friction clutch similar to that of a manual vehicle, and a manual vehicle. A synchronous mesh transmission (hereinafter simply referred to as a transmission) 2, a gear shift unit (hereinafter referred to as GSU) 3 that performs a gear shift operation using a fluid pressure gear actuator (not shown), and the like. Consists of This is a so-called mechanical automatic transmission (AMT), and is suitable for large vehicles such as trucks and buses.

  In the engine 4, an injection pump 5 (fuel supply means) that controls the fuel injection amount and supplies fuel to the engine 4 is controlled by a control signal L2 from the engine ECU 6 (engine output control means). The engine speed signal L4 and the like from the engine speed sensor 7 (engine speed detection means) for detecting the engine speed is monitored so that, for example, the output torque of the engine is maintained in a desired operating state. It is controlled.

  The clutch 1 that connects and disconnects the transmission torque from the engine 4 to the transmission 2 is automatically connected and disconnected by controlling the stroke amount of the clutch plate by a fluid pressure type clutch actuator 8 (clutch stroke control means). It is configured as follows. Specifically, the stroke amount signal L7 of the clutch actuator 8 is fed back to the AMT ECU 9, the clutch control unit is controlled by the control signal from the AMT ECU 9 based on the stroke amount, and the fluid to the clutch actuator 8 is controlled. By supplying or discharging, the stroke amount of the clutch actuator 8 is controlled to the target stroke, and the clutch 1 is connected or disconnected. The clutch actuator 8 is provided with a clutch stroke sensor (clutch stroke detecting means) for detecting the stroke amount of the clutch plate (not shown), and based on the stroke amount signal L7 of the clutch stroke sensor, a target stroke is obtained. PID feedback control is performed by the AMT ECU 9 so as to follow. With the above configuration, not only two states of clutch connection / disconnection but also a half clutch state in a manual transmission can be achieved, and the output of the engine 4 can be smoothly transmitted to the transmission 2. Can do.

  Since the configuration of the transmission 2 itself is not directly related to the present invention, the related portions will be briefly described. The transmission 2 is an automatic transmission that has a plurality of forward speeds in addition to the reverse speed. A GSU 3 for selecting a gear position inside the transmission is provided at the upper part of the transmission 2. The GSU 3 is driven by high-pressure air supplied from the air tank 10 or the like, and an internal gear actuator or the like is driven. A shift operation is automatically performed. A gear position sensor for detecting the gear position is provided in the GSU 3, and the transmission gear position signal L8 from the gear position sensor is monitored by the AMT ECU 9, and a control signal L8 is sent from the AMT ECU 9 to the GSU 3 at the time of shifting. Outputs and shifts.

  The air tank 10 is provided as an air pressure source for operating the brake, and is configured to supply the operating air to the wheel cylinders 13 and 14 via the air masters 11 and 12 to perform the operation. These are controlled by a brake valve (not shown), but are configured to be automatically braked by the operation of the uphill road start assist brake magnet valves 15 and 16 when starting uphill road.

  The operating air from the air tank 10 is supplied not only to the brake system of the wheel cylinders 13 and 14 but also to the gear actuator and clutch actuator 8 of the GSU 3, and the required operation state is realized by each operation. It is configured to be. That is, in these actuators, air pressure is used as the fluid pressure (also referred to as a pneumatic actuator), and in this embodiment, as the air pressure source (fluid pressure source), the air tank 10 which is the air pressure source for brake operation is used. Are backed up by an emergency air tank 17. Instead of the pneumatic actuator, an electro-hydraulic actuator or an actuator directly driven by an electric motor may be used.

  A depression amount signal L9 of the accelerator pedal 18 is input to the AMT ECU 9, and an accelerator opening corresponding to the depression amount signal L9 is detected (accelerator opening detection means). The engine speed signal L4 from the engine speed sensor 7 of the engine ECU 6, the clutch speed signal L6 from the clutch speed sensor 20 of the clutch 1, the transmission gear position signal L8 from GSU3, the vehicle speed sensor of the transmission 2 The vehicle speed signal L10 from 21 is input. Based on these input signals, the AMT ECU 9 outputs an accelerator signal L1 to the engine ECU 6, outputs a clutch connection / disconnection control signal L7 to the clutch 1, and outputs a transmission gear position signal L8 to the GSU3. A line for controlling the operation of the GSU 3 and the clutch actuator 8 to perform the clutch connecting / disconnecting operation and the gear selection operation. In addition, necessary signals are also output to the braking system and other devices, for example, the display signal L11 of the selected gear stage is displayed on the gear stage display 19.

  The driving command of the driver is configured to be transmitted by the accelerator opening and the position of the shift lever. When the shift lever is set to the D range (Drive) after the engine is started, the gear is set to “1st” or “2nd”. "Is selected and the accelerator pedal 18 is depressed, the start operation is started.

  The engine ECU 6 and the AMT ECU 9 are each an arithmetic processing device (so-called CPU), a storage device (so-called ROM, RAM, which holds a control program, map data, etc., and serves as an arithmetic work area), input / output. It is composed of an interface or the like that becomes a signal processing circuit. Using map data (for example, map data of a target torque with respect to an accelerator opening, which will be described later, map data of a fuel injection amount with respect to an engine speed) based on input information (detected values by a sensor, etc.) Based on the calculated calculation results, the engine and the clutch device are controlled in conjunction with each other, and not only when driving but also when starting, clutch control and shift control corresponding to the accelerator opening, Performed in conjunction with engine control.

  The details will be described with reference to FIGS. 2 and 3, but the vehicle start control device according to the present invention does not simply perform the clutch connection / disconnection control at the start, but at the start, the accelerator opening degree The optimal target torque is set according to the target torque, the clutch transmission torque, that is, the clutch stroke is controlled with respect to the set target torque, and the engine torque, that is, the fuel injection amount is set with respect to the set target torque. It is characterized by being able to start smoothly without excessive load being applied to the clutch when the clutch is connected. Note that when starting on an uphill road, an auxiliary brake for starting a hill is activated, and the auxiliary brake is controlled so as to release the braking state of the brake at an appropriate timing in conjunction with the starting operation.

  FIG. 2 is a block diagram showing an example of start control according to the present invention.

The start control according to the present invention shown in FIG. 2 starts by satisfying all the following start conditions.
(1) Check whether the currently selected gear stage is a predetermined gear stage. As the predetermined gear stage, for example, it is confirmed whether it is a first speed gear stage or a second speed gear stage as a starting gear stage.
(2) Check if the clutch 1 is disengaged.
(3) Check whether the accelerator pedal 18 is depressed.
(4) Check if clutch speed <engine speed.
That is, it is confirmed whether the start condition is a state where the vehicle is about to start from a state where the vehicle is stopped.

  When all the start control start conditions are satisfied, the accelerator opening is calculated based on the depression amount L9 of the accelerator pedal 18 at the start, and the preset target torque and accelerator opening map data are calculated from the calculated accelerator opening. Is used to set the target torque (block B1, target torque setting means). In order to obtain an acceleration feeling according to the driver's intention, the map data is preferably data that can provide an ideal acceleration feeling when the driver depresses the accelerator pedal at the time of departure. As an example, in the block B1 of FIG. 2, in the region where the accelerator opening is small, the increase rate of the target torque with respect to the accelerator opening is increased, the acceleration is improved, and in the region where the accelerator opening is medium, the target for the accelerator opening is obtained. The rate of increase in torque is moderated so that it can be easily used for low-speed driving such as garage entry, and in a region where the accelerator opening is large, the increase rate of the target torque with respect to the accelerator opening is increased to improve responsiveness and open the accelerator. In a considerably large range, the target torque with respect to the accelerator opening is kept constant to prevent sudden acceleration.

  Based on the calculated target torque, the clutch side obtains the base clutch stroke, and the engine side obtains the fuel injection amount that becomes the target torque for which the engine torque is calculated. At this time, the clutch stroke and the fuel injection amount may be obtained immediately based on the calculated target torque, but a temporary delay coefficient is applied to the calculated target torque to avoid a sudden change in the target torque. May be. This is to prevent the vehicle from starting suddenly more than necessary when the accelerator pedal 18 is depressed suddenly.

  Specifically, on the clutch side, if the temporary delay constant is Ts, the target torque is multiplied by a coefficient {1 / (1 + Ts)} (block B2, temporary delay means), and a predetermined proportional coefficient, for example, 0.75 is added (block B3, coefficient integration means) to obtain the clutch transmission torque, and the clutch stroke instructed to the clutch is obtained using the map data of the clutch stroke with respect to the clutch transmission torque (block B4, transmission torque setting). means). At this time, the engine torque is controlled so as to be the target torque so as not to increase unnecessarily (see blocks B6 and B7 described later).

  The actually controlled stroke amount is determined based on the PID based on the deviation between the set target engine speed (refer to block B7 described later) and the actual engine speed. The amount of stroke is controlled using the control, and the clutch stroke is controlled in the connecting direction as the engine speed increases (block B5, clutch stroke control means). Finally, the clutch is completely connected and the vehicle starts. Is done. The predetermined proportionality coefficient is preferably a coefficient of 1 or less. By applying this proportionality coefficient, it is meaningful to reduce the stroke amount actually controlled with respect to the clutch stroke data in the map data of the block B4, so that the engine torque is always kept larger than the clutch transmission torque. The engine is not stopped when the clutch stroke is controlled in the connecting direction. The temporary delay constant Ts is set in advance by determining an appropriate value from the acceleration of the vehicle.

  The relationship between the clutch stroke and the transmission torque has a transmission torque corresponding to the stroke amount as shown in the graph shown in block B4, and the clutch connection side (in the graph of block B4, the clutch stroke becomes smaller). There is a characteristic that the transmission torque in the half-clutch increases as it moves to.

  Also, the engine side uses the temporary delay constant Ts to integrate the {1 / (1 + Ts)} coefficient with respect to the target torque (block B6, temporary delay means) to obtain the engine torque, and the current engine speed Using the map data of the engine torque and the fuel injection amount with respect to the engine speed, the fuel injection amount at the target engine speed is obtained (block B7, engine torque setting means) from the obtained engine torque. The engine is controlled by instructing the fuel injection amount.

FIG. 3 is a block diagram showing another example of the start control according to the present invention.
Here, the description overlapping with the first embodiment will be omitted.

  The start control of the present embodiment uses the same control as that of the first embodiment as the main control. However, it differs from the first embodiment in that the fuel injection amount is controlled using PID control in the engine-side control (see block B8).

  In the case of this embodiment, the engine torque is set with a temporary delay to the target torque set in the block B1 (target torque setting means) (block B6, temporary delay means), and the engine set with a temporary delay. From the torque, a base target engine speed is obtained (block B7, engine torque setting means). Then, in order not to unnecessarily increase the engine speed, the fuel injection amount is further PID-controlled based on a deviation from the actual engine speed with respect to the base target engine speed to control the engine output. (Block B8, engine output control means).

It is the schematic which shows an example of embodiment of the vehicle start control apparatus which concerns on this invention. It is a block diagram which shows an example of start control which concerns on this invention. It is a block diagram which shows another example of start control which concerns on this invention.

Explanation of symbols

1 Clutch 2 Transmission 3 GSU
4 Engine 5 Injection pump 6 Engine ECU
7 Engine speed sensor 8 Clutch actuator 9 AMT ECU
18 Accelerator pedal 20 Clutch speed sensor 21 Vehicle speed sensor

Claims (6)

A clutch for connecting and disconnecting the transmission torque from the vehicle engine to the transmission;
Clutch stroke control means for controlling a stroke amount of connection of the clutch;
An accelerator opening detecting means for detecting an accelerator opening corresponding to the amount of depression of the accelerator pedal;
Fuel supply means for controlling the fuel injection amount and supplying fuel to the engine;
Engine output control means for controlling the fuel supply means to control the output torque of the engine,
When the vehicle starts,
Target torque setting means for setting a target torque according to the accelerator opening detected by the accelerator opening detection means;
Transmission torque setting means for setting the transmission torque of the clutch according to the target torque set by the target torque setting means;
Using engine torque setting means for setting the output torque of the engine according to the target torque set by the target torque setting means,
The engine output control means controls the fuel injection amount to be the engine output torque set by the engine torque setting means,
The clutch stroke control means sets a clutch stroke according to the transmission torque of the clutch set by the transmission torque setting means, and controls the stroke amount of the clutch that becomes the set clutch stroke, so that the clutch The vehicle start control device is characterized by performing a connecting operation. In the vehicle start control device according to claim 1,
The transmission torque setting means includes temporary delay means for setting the target torque set by the target torque setting means to a transmission torque having a temporary delay,
The clutch stroke control means sets a clutch stroke according to the set transmission torque of the temporary delay, controls the stroke amount of the clutch to be the set clutch stroke, and performs the clutch connecting operation. A vehicle start control device. In the vehicle start control device according to claim 2,
The transmission torque setting means includes coefficient integration means for setting the temporarily delayed transmission torque as transmission torque obtained by integrating a predetermined coefficient of 1 or less,
The clutch stroke control means sets a clutch stroke according to the transmission torque integrated with the predetermined coefficient, controls the stroke amount of the clutch to be the set clutch stroke, and performs the clutch connecting operation. A vehicle start control device. In the vehicle start control device according to any one of claims 1 to 3,
The engine torque setting means has a temporary delay setting means that uses the target torque set by the target torque setting means as an output torque of the engine having a temporary delay,
The engine output control means sets an engine speed according to the set engine output torque of the temporarily delayed engine, and controls a fuel injection amount that becomes the set engine speed. Start control device. The vehicle start control device according to claim 4,
Clutch stroke detecting means for detecting a stroke amount of the clutch;
The start control apparatus for a vehicle, wherein the clutch stroke control means controls the stroke amount by PID control based on a deviation between the set engine speed and the actual engine speed. The vehicle start control device according to any one of claims 1 to 5,
An engine speed detecting means for detecting the engine speed;
The engine output control means controls the fuel injection amount by PID control based on a deviation between the set engine speed and the actual engine speed detected by the engine speed detection means. A vehicle start control device.

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