JP2003267090A - Automatic control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent engine stall due to braking action when a vehicle is braked due to the control of an inter-vehicle distance radar device independent of drive operation, and also to make engine brake work effectively when the vehicle is controlled to be braked. <P>SOLUTION: When engine speed is reduced enough to approach idling speed, where engine braking becomes ineffective, due to brake control by monitoring engine speed, a clutch is disengaged automatically. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an automatic braking device for automatically controlling a vehicle in a braking state even when the vehicle is running without any driving operation. INDUSTRIAL APPLICABILITY The present invention can be applied to a vehicle equipped with a manual transmission, as well as a semi-automatic transmission and a fully automatic transmission.

[0002]

2. Description of the Related Art When a vehicle is equipped with an inter-vehicle distance detecting device, an obstacle detecting device or the like, an alarm output is generated in the driver's seat by the detection output of these detecting devices, and the automatic output is performed without the driver's operation. A device provided with an automatic braking device that actively operates a brake is under study. This device operates by the detection output of a device that observes the distance to a preceding vehicle traveling on the same lane on the road by, for example, an inter-vehicle distance radar. That is, when the inter-vehicle distance observed corresponding to the vehicle speed at that time is smaller than the predetermined limit, an alarm is generated in the driver's seat to prompt the driver to decelerate the vehicle, and the driver When the operation for deceleration is not performed, or when the deceleration due to the operation is insufficient, the vehicle is automatically brought into the braking state even if there is no driving operation.

When the driver puts the vehicle in a braking state by himself / herself, a clutch operation and the like can be performed together so that the engine rotation is not stopped by the brake operation. However, when the vehicle is automatically controlled to the braking state without the driver being aware of it, the clutch operation of the driver may be delayed or the clutch operation may not be performed.

Japanese Unexamined Patent Publication No. Hei 6-272761 (Applicant: Mitsubishi Motors) discloses a semi-automatic transmission that automatically engages the clutch when an emergency braking operation is performed without the driver operating the clutch. There is disclosed a technique for controlling the engine to be stopped so as to prevent the engine rotation from stopping (paragraph [0012] and others of the above publication).

[0005]

With the adoption of the inter-vehicle distance radar and the obstacle detection device, the inventor of the present application has studied an automatic braking device that operates by its detection output. Among them, it has been recognized that when the automatic braking device is actuated regardless of the driving operation of the driver and the driver's clutch operation is delayed due to this, the engine rotation may stop. When the engine rotation is stopped, it is necessary to consider a situation in which hydraulic pressures for various controls are reduced within a relatively short time, and the power steering device malfunctions, for example.

When it is observed by the inter-vehicle distance radar that the distance to the preceding vehicle is closer to the traveling speed at that time, the flow rate of the fuel supplied to the engine is controlled to be small, and the so-called engine braking state is set. It is desirable to slow down the vehicle at. Even if other automatic braking means are interlocked with each other, it is desirable to make the braking effect more effective as the state of engine braking. On the other hand, as disclosed in the above publication, when the vehicle is in the braking state according to automatic control in consideration of the delay in the clutch operation by the driver, the clutch is interlocked to release the clutch. If controlled, the deceleration effect of engine braking cannot be expected.

The present invention has been made against such a background, and the deceleration effect by the engine brake is effectively exerted even when the braking device is automatically operated without the driver's operation. An object of the present invention is to provide a device in which the engine rotation does not stop due to automatic braking control even if the driver's clutch operation is delayed. An object of the present invention is to provide an automatic braking device in which engine rotation is stopped due to a delay in driving operation and hydraulic pressure is not lost.

[0008]

According to the present invention, when a vehicle is controlled to be in a braking state by automatic braking control, the engine and the brake are effective with the clutch and the transmission connected to the drive shaft of the vehicle. While maintaining the state,
The greatest feature is that the clutch is automatically controlled to the disengaged state when the engine speed becomes close to the idling speed.

With this configuration, the vehicle automatically controlled to be in the braking state can perform deceleration control by the engine braking in the range where the engine braking is effective.
That is, the fuel flow rate of the engine is adjusted and controlled so that the engine rotates at a predetermined idling speed when a load for driving and driving the vehicle is not coupled to the output shaft. When the vehicle speed is reduced by automatically controlling the braking while the vehicle is running, the engine output shaft and the axle are kept connected from the start of deceleration until the engine reaches the idling speed, and the effect of engine braking is maintained. Can be expected. When the rotational speed of the engine approaches the idling speed, the engine control device automatically controls the fuel flow rate so as to maintain the idling speed. Therefore, if the engine speed falls below the idling speed, the effect of engine braking cannot be expected. At the same time, when the engine output shaft is connected to the axle, the engine rotation may be forcibly stopped by the braking control of the wheels. Therefore, by using the engine speed as an input, and controlling the clutch to be disengaged when the engine speed approaches a predetermined idling speed, the effect of engine braking can be obtained, and the engine speed can be reduced. It is possible to avoid forcibly stopping.

That is, according to the present invention, when a set logical condition is satisfied according to the outputs of sensors including a vehicle speed sensor (25) and an engine speed sensor (8) provided in the vehicle, the vehicle is automatically operated even without a driving operation. In an automatic braking device equipped with a means (18) for controlling to a braking state, a state in which the transmission (3) and the clutch (2) are connected to the output shaft of the engine (1) when the braking state is controlled It is characterized in that it is provided with a means for maintaining the rotation speed of the engine (1) and controlling the clutch (2) to a disengaged state even when there is no driving operation when the rotation speed of the engine (1) becomes close to the idling speed.

The numbers in the above parentheses are reference numbers in the embodiment drawings described later. This is given for easy understanding of the present invention, and is not for limiting and understanding the present invention. The same applies to the following description.

To illustrate the above-mentioned "set logical condition", in a vehicle equipped with an inter-vehicle distance radar, the vehicle speed is xxkm /
When h or more, when the distance from the preceding vehicle traveling in the same lane becomes yy meters or less from the detection output of the inter-vehicle distance radar, it can be set. Another example is when a vehicle equipped with an obstacle radar detects an obstacle in its path.

The means (18) for controlling the braking state controls the vehicle to the engine braking state by reducing the fuel flow rate supplied to the engine (1) regardless of the operation of the clutch pedal (11). It can be configured to include means.

The value close to the idling speed can be selected in the range of minus 5% to plus 25% of the standard idling speed of the engine.

As described above, the present invention can be applied to a vehicle equipped with a manual transmission, as well as a semi-automatic transmission and a fully automatic transmission. The manual transmission device is a device configured to select a combination of a clutch operated by a clutch pedal and a gear having a different gear ratio by a manual transmission lever. The automatic transmission is a device that does not have a clutch pedal in the driver's seat, and is configured to automatically perform engagement / disengagement of a clutch and selection of a combination of gears according to an engine rotation speed and a vehicle speed. This is a so-called automatic vehicle transmission. The semi-automatic transmission device is a device in which a clutch pedal is provided in the driver's seat, although engagement / disengagement of a clutch and selection of a combination of gears are automatically executed by arithmetic control of a control circuit. By operating the clutch pedal, the clutch in the connected state can be overridden according to automatic control, and the clutch can be mechanically controlled to the disengaged state or the half-clutch state.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION First, referring to FIG. 1, the overall structure of an apparatus according to the present invention will be described. This example relates to the semi-automatic transmission described above. Engine 1
Is transmitted to the transmission 3 via the clutch 2 and is further transmitted from the propeller shaft 4 to an axle (not shown).
The fuel injection pump 5 of the engine 1 is controlled by an engine ECU 6 configured by a program control circuit.
The clutch 2 of this device is a mechanical clutch, and its engaging / disengaging operation is controlled by a clutch actuator 27. In this example, the transmission 3 is a mechanical type having seven forward gears and one reverse gear, and is controlled by the shift actuator 7 in the XY directions. The clutch actuator 27 and the shift actuator 7 are controlled by the air pressure supplied from the air tank 28. The air pressure supplied to the clutch actuator 27 is controlled by the clutch control valve 9. The shift actuator 7 has control valves for the X direction (shift) and the Y direction (select) built therein, and air pressure is supplied to the shift cylinder and the select cylinder via these control valves. Clutch control valve 9 and shift actuator 7
The control valve built in is electrically controlled by the transmission ECU 10 configured by a program control circuit.

In addition to being controlled by the clutch actuator 27, the clutch 2 can be mechanically controlled directly via the hydraulic system 13 by the hydraulic pump 12 driven by the clutch pedal 11 as described above. Is configured. That is, when the clutch 2 is in the connected state, the clutch pedal 11 in the driver's seat
By stepping on, the driver can control the engagement / disengagement of the clutch including the half-clutch state. By utilizing the clutch control by the clutch pedal 11, the driver can perform the control by his / her own clutch operation without depending on the control of the automatic clutch when the vehicle starts from the stopped state. The clutch disengagement operation by the clutch pedal 11 has priority over the clutch control by the transmission ECU 10. Generally, the clutch operation by the clutch pedal 11 is often used at the time of starting or when passing through a curve while accelerating or decelerating. As explained above,
The drivers of this type of vehicle are generally professional drivers,
Do not feel bothersome to control the clutch connection state with your left foot. Rather, the delicate clutch control in the low gear at the start is performed as desired by oneself,
This device is well-received by drivers because of its smooth starting. Then, by performing clutch control with the driver's left foot when starting, it is possible to save fuel consumption and reduce the amount of exhaust gas.

Interlocking with the operation of the clutch pedal 11,
Clutch switch 14 for detecting that clutch pedal 11 is in the released state, and clutch pedal 11
Clutch switch 15 to detect when the pedal is depressed
Are provided, and the detection outputs of these are taken into the transmission ECU 10. The accelerator pedal 16 is provided with an accelerator position sensor 17, whose output is taken into the engine ECU 6. The output of the engine rotation sensor 8 is taken into the engine ECU.

The state of the shift lever 23 provided in the driver's seat is taken into the transmission ECU 10. As shown, the speed change lever 23 can be set to three positions of N range (neutral position), D range (drive position), H range (hold position) and R range (reverse position). When the gear shift lever 23 is set to the D range at the time of starting, all the gear selection settings after starting are automatically executed by the control of the transmission ECU 10.
For example, when the shift lever 23 is shifted to the D range and the vehicle is started, the shift gear is automatically shifted up according to the acceleration state. Each time the transmission gear is changed, the clutch 2 is repeatedly disconnected and connected under the control of the transmission ECU 10, and the fuel flow rate supplied to the engine 1 is adjusted in synchronization therewith.

Further, when the shift lever 23 is in the H range, by operating the lever up or down, the driver instructs exceptional shift up or shift down for automatic gear selection. can do.
This operation can be performed upshift or downshift by two steps by shaking upshift or downshift twice. Also at this time, the clutch 2 is automatically disengaged, the gear shift is executed, the clutch 2 is controlled to be automatically connected, and the fuel flow rate is automatically adjusted.

The vehicle speed information is taken into the transmission ECU 10 from the vehicle speed sensor 25 which detects the rotation of the propeller shaft 4. In order to detect the state of the transmission 3, the transmission 3 is provided with a counter shaft rotation sensor 26, and this output information is taken into the transmission ECU 10.

The transmission ECU 10 is an engine ECU 6
And a communication bus 24. The transmission ECU 10 is also connected to the automatic braking control ECU 18 via the communication bus 24. This automatic braking control EC
U18 is a component directly related to the present invention, which takes in outputs of sensors including a vehicle speed sensor 25 and an engine rotation sensor 8 provided in the vehicle, and executes automatic braking control according to the sensor outputs. In this example,
In addition to the above, the distance information to the preceding vehicle from the inter-vehicle distance radar (not shown) is input as a sensor input to the automatic braking control ECU 18. The automatic braking control ECU 18 automatically controls the braking of the vehicle according to the set logic according to the input vehicle speed information and the distance information. The control output is sent to the retarder control system 19, the air brake control system 20, and the exhaust brake control system 21 as a control output. The status information from each of the brake control systems 19, 20, and 21 in response to this control output is the transmission EC.
Used in U10.

According to the present invention, the automatic braking control ECU 18,
The control operation of the engine ECU 6 and the transmission ECU 10 is characteristic. That is, when the vehicle is automatically controlled to be in the braking state without any driving operation, the state in which the transmission 3 and the clutch 2 are connected to the output shaft of the engine 1 is maintained for the period in which the wheels are in the braking state. Let At this time, irrespective of the operation amount of the clutch pedal 11, the engine ECU 6 reduces the fuel flow rate supplied to the engine 1 to control the vehicle to the engine / brake state. Only when the rotational speed of the engine 1 reaches a value close to the idling speed, the clutch 2 is controlled to the disengaged state even if there is no driving operation. With this control, the vehicle can be effectively decelerated by maintaining the so-called engine brake state together with the braking of the wheels, and even if the vehicle speed decreases and the engine speed is maintained at the idling speed, this accelerates the vehicle. When such a situation occurs, the engine rotation and the axle rotation are separated.

FIG. 2 is a control flow chart for performing clutch control in the apparatus of the present invention. The point of this control logic is to monitor the engine speed and when the engine speed is above the idling speed,
This is where the braking control is executed with the clutch still connected. The clutch is controlled to the disengaged state only when the engine speed falls below the idling speed. With this operation, the engine brake is applied for the period during which automatic braking control is being executed, and the clutch is disengaged when the engine speed drops and the engine brake no longer works You can avoid stopping the engine rotation.

Although the above embodiment describes a vehicle equipped with a semi-automatic transmission, the present invention can be similarly applied to vehicles having other structures. When the present invention is applied to a vehicle equipped with a clutch device that directly uses the depression force of the driver's clutch pedal, it is necessary to provide auxiliary power for opening and closing the clutch.
Depending on the structure of the vehicle or the existing clutch, the present invention can be achieved by providing another clutch that is mechanically connected in series with the clutch that is opened and closed by the clutch pedal and that is opened and closed by another power other than the clutch pedal. It can be carried out. Even in a vehicle that is not provided with a clutch that is opened and closed by a clutch / pedal or a clutch that is opened and closed by mechanical power, the present invention can be achieved by separately providing a clutch that can be opened and closed by an electric signal in series with the power transmission system. It can be carried out.

Even when a dedicated clutch is added to carry out the present invention, the operation of opening and closing the clutch for the purpose of the present invention is performed by the power transmitted through the clutch.
Regardless of the direction from the engine to the wheels or from the vehicle to the engine, the engine speed is almost idling speed at the timing of disengaging the clutch, and the power transmitted through the clutch is extremely small. Therefore, the present invention can be implemented by adding a simple clutch.
In this case as well, the timing at which the clutch is switched from the disengaged state to the connected state can be used when the transmission is in the neutral state. Therefore, the transmitted power when the clutch is connected should be substantially zero. You can

Regarding the clutch control mechanism, the one using air pressure has been described in the above embodiment, but the same is applied to the one using hydraulic pressure, electric motor, solenoid actuator, and other mechanical power. can do. As for the structure of the clutch, the same structure can be applied to a dry type, a wet type, a dog type, a one-way type, or any other type having a clutch mechanism.

[0028]

According to the present invention, the deceleration effect by the engine / brake is effectively exerted even when the braking device is automatically activated without the driver's operation, and the clutch operation by the driver is delayed. It is possible to provide a device in which the engine rotation does not stop due to automatic braking control. With the device of the present invention, there is no inconvenience such as the engine rotation stopping due to the delay of the driving operation and the oil pressure being lost.

[0029]

[Brief description of drawings]

FIG. 1 is a block configuration diagram of an apparatus according to an embodiment of the present invention.

FIG. 2 is a flowchart of a control main part of the device according to the embodiment of the present invention.

[Explanation of symbols]

1 engine 2 clutch 3 transmission 4 propeller shaft 5 Fuel injection pump 6 engine ECU 7 shift actuator 8 Engine rotation sensor 9 Clutch control valve 10 Transmission ECU 11 clutch pedal 12 hydraulic pump 13 Hydraulic system 14 Clutch switch (upper end) 15 Clutch switch (bottom end) 16 accelerator pedal 17 Accelerator position sensor 18 Automatic braking control ECU 19 Retarder control system 20 Air brake control system 21 Exhaust brake control system 22 Brake pressure information 23 Gear lever 24 communication bus 25 vehicle speed sensor 26 Counter shaft rotation sensor 27 Clutch / Actuator 28 air tanks 35 Pressure sensor 36 Emergency valve 37 Emergency air pressure

Continuation of front page (51) Int.Cl. ⁷ identification code FI theme code (reference) B60T 7/12 B60T 7/12 B F02D 29/00 F02D 29/00 G 41/04 380 41/04 380G F16D 23/00 F16D 23/00 M 48/02 25/14 640Q (72) Inventor Yuji Kobayashi 3-1-1 Hinodai, Hino City, Tokyo Hino Motors Co., Ltd. F-term (reference) 3D041 AA33 AA36 AA42 AA57 AB01 AC01 AC11 AC26 AD06 AD06 AD41 AE07 AE16 AE41 3D046 BB17 EE03 GG02 GG05 GG06 HH05 HH06 HH17 HH20 HH22 3G093 AA04 BA05 CA04 CB07 DA01 DB05 DB10 DB11 DB16 EA03 GBEA05 GA01 BB01 PF01 A02 ZA01 LB01 PE02 AZ01 ZA01 LB01 PE01 ND01 PE11 AZ01 ZA01 LB01 PE01 AZ01 ZA01 LB01 PE01 ND01 GB40 GE07 HH01 JJ04

Claims (3)

[Claims] 1. A means for automatically controlling a vehicle to a braking state according to outputs of sensors including a vehicle speed sensor and an engine rotation sensor provided on the vehicle, even if a driving operation is not performed, when a set logical condition is satisfied. In the automatic braking device, the transmission and the clutch are kept connected to the output shaft of the engine while being controlled to the braking state, and the driving operation is performed when the rotation speed of the engine becomes close to the idling speed. An automatic braking device comprising means for controlling the clutch to a disengaged state at least. 2. The means for controlling the braking state includes means for controlling the vehicle in an engine braking state by reducing the fuel flow rate supplied to the engine regardless of the operation of the accelerator pedal. Automatic braking system. 3. The automatic braking system according to claim 1, wherein the value close to the idling speed is in the range of -5% to + 25% of the standard idling speed of the engine.