JP2008522108A - Method and system for controlling a motor vehicle with a clutch actuated by an actuator - Google Patents

Abstract

In a stop-and-go type automobile, a biting point of a clutch operated by an actuator can be determined.
Provided is an actuator-operated clutch (E) provided with a device (26) for automatically stopping and restarting an engine (10) under predetermined conditions, said device (26) We propose a method and system for controlling a vehicle that determines the biting point of a clutch (E) that is actuated by an actuator during a time prior to the shutdown of the vehicle engine (10) controlled by.
[Selection] Figure 1

Description

  The present invention relates to a method and system for controlling a motor vehicle equipped with an actuator actuated clutch provided with a device for automatically stopping and restarting the engine.

  Devices for automatically stopping and restarting the engine (commonly called stop-and-go devices) are basically used when an automobile stops at traffic lights and traffic jams, for example in urban environments In this case, the amount of fuel consumption is reduced, and therefore, air pollution caused by exhaust gas from the engine of the vehicle is reduced.

  This device is preferably used in combination with a robotized gearbox, an automatic gearbox or a clutch control device operated by an actuator associated with a manual gearbox with a clutch pedal that operates via an electrical connection. .

  In order to control the clutch by the actuator, the biting point of the clutch, that is, the point on the clutch curve furthest forward in the clutching direction where torque is not transmitted is determined and the vehicle transmission device is controlled while controlling the operation of the clutch. This point change must be monitored to prevent backlash and surge.

  Various methods for determining this point have been proposed, but none of these are satisfactory and sometimes difficult to implement.

  The present invention relates to a method for determining the biting point of an actuator-actuated clutch in a vehicle provided with a device of the type described above for automatically stopping and restarting the engine, this determination being a behavior of the vehicle. And is performed within the available time without compromising driving comfort.

To this end, the present invention provides a device for automatically stopping and restarting the engine under predetermined conditions including a clutch (E) actuated by an actuator (24) and a neutral position of the gearbox. (26) In the method for controlling a motor vehicle,
When the engine (10) is instructed to stop by the device (26), the biting point of the clutch (E) is determined during a time prior to stopping the engine (10) of the automobile. It proposes a control method for automobiles.

  Thus, the method according to the present invention provides the time between the actual stop of the engine and the stop command indicated by the device when the desired condition is met in order to determine the clutch biting point. It uses the length. This length of time is generally as short as about 1 second, but is sufficient to make this determination, and when run under these conditions, the vehicle stops and does not compromise vehicle behavior or drive comfort A decision is made.

  According to another aspect of the invention, the method of the invention is commanded by the device to determine the clutch biting point each time the engine is stopped.

  This makes it possible to monitor changes in the biting point with high accuracy, depending on the environmental conditions and the engine and the function of the vehicle, and thus by the actuator so as not to impair the behavior of the vehicle and the comfort of the drive. The operation of the operating clutch can be precisely controlled.

  The present invention is also adapted to prohibit or stop the determination of the biting point if the time length is too short for this determination.

  This prevents delays in stopping the vehicle's engine once such a stop has been commanded by the device for automatic stop and restart, and biting during the next stop operation. Can perform point determination.

  Preferably, the method of the invention detects the position of the biting point of the clutch by detecting the rotation of the input shaft of the automobile gearbox.

  Actually, according to the method of the present invention, when the rotational speed of the engine is equal to or higher than a predetermined minimum value, the clutch starting point is gradually closed to detect the clutch biting point.

  This determination of the biting point is completely transparent and obvious to the vehicle driver or passenger. The reason is that when the clutch is disengaged, the gearbox is in the neutral or center dead position, and if the gearbox input shaft stops (in principle the vehicle stops), all that is needed is the vehicle gear This is because it is only necessary to partially close and release the clutch again until it detects the start of rotation of the box input shaft and then returns to its original state.

  Since the clutch is operated by an actuator that includes a movable element whose displacement corresponds to opening and closing of the clutch, the method of the present invention detects the position of this movable element of the actuator when it corresponds to the biting point of the clutch, Can be recorded.

  Before performing a new determination of the biting point, also use the stop command given by the device and the time until the actual stop of the engine, the value recorded before the clutch biting point, or the actuator of the clutch Find the corresponding position of the movable element. As a result, the change of the biting point can be confirmed directly.

  The present invention also provides a system for controlling an automobile for carrying out the above method, a means for detecting and recording a position of a movable element of an actuator acting on a clutch of the automobile, and a gear of the automobile. Means for detecting the rotation or rotational speed of the input shaft of the box; and connected to the device for automatically stopping and starting the detecting means and the engine, the actuator in the closing direction of the clutch Control and a movable element of the actuator corresponding to the start of rotation of the input shaft starting from substantially zero rotation of the input shaft of the gearbox during a time prior to engine shutdown commanded by the device. Means for processing the information programmed to record the position. System for controlling the motor vehicle, characterized in Rukoto is also proposes.

  In order to improve the performance of the vehicle as well as its ease of use and driving comfort, other means can be provided in the system according to the invention.

  For example, a clutch operated by an actuator and a device for automatically stopping and restarting the engine can be associated with creeping means (creeping refers to vehicle displacement at very low speed). This creeping means acts when the driver releases the brake pedal. This means that the driver has to step on the pedal to prevent the vehicle from moving, so it will automatically stop and restart when the desired conditions are met. This means that the device can stop the engine.

  If the vehicle is equipped with an air conditioner, the auxiliary means for regulating the temperature in the passenger compartment of the vehicle when the engine is stopped by the device for stopping and restarting automatically It may be provided.

  With this auxiliary means, for example when the engine is running, this storage is made when the engine is stopped, for example by forming the cold (or hot) stockpile, automatically stopping and restarting the device. Things can be used.

  It is also possible to provide means for detecting the position of the vehicle in an area with many hills. In this case, the detection means includes, for example, an inclinometer for preventing the device from stopping the engine when a desired condition is satisfied. This can prevent the vehicle from slipping backward when the engine is restarted. Such rearward slipping usually results in rattling or surge in the transmission.

  The means and the brake locking means can also be related to release the brake only after the passage of torque is detected in the air conditioner operated by the actuator. This can prevent the vehicle from slipping backward when the engine is restarted.

  In some cases, it is activated by an actuator during the displacement of the vehicle when transitioning from low speed, rather than when the vehicle is stopped just before the engine is stopped, which is commanded by the device for automatic stop and restart. It is also possible to detect the biting point of the clutch to be used. This biting point is measured while the clutch is closed by detecting the inflection point of the rotational speed of the engine output shaft.

  The clutch may or may not include automatic means for compensating for wear.

  BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood and other features, details and advantages of the invention will become more apparent from the following description, given by way of example, with reference to the accompanying drawings.

  The control system of the present invention is adapted to be mounted on a motor vehicle having a conventional type of internal combustion engine 10, and the output shaft 12 of the engine 10 is connected by a clutch E to a gear box 16, for example a robotized mechanical type. It is connected to the input shaft 14 of the gear box, and the output shaft of the gear box 16 drives the driving wheel 20 of the automobile via the differential gear 22.

  The clutch E is operated by, for example, an electric or fluid actuator 24 that includes a movable element for actuating the clutch.

  The automobile is also provided with a device 26 for stopping and restarting the engine automatically, that is, a stop-and-go device. The device 26 basically comprises a reversible alternator and starter that is conventionally controlled by a computer 28 including one or more microprocessors, memory, and input / output interfaces. 24 and gearbox 16 can also be controlled.

The device 26 for automatically stopping and restarting commands to stop the automobile engine 10 to reduce fuel consumption when the following conditions are met.
The gearbox 16 is in the neutral position (or center dead position).
-Clutch E is open.
The gearbox input shaft 16 is not rotating;
The rotational speed of the output shaft 12 of the engine 10 is, for example, greater than or equal to a predetermined minimum corresponding to the idling speed.
The vehicle is stopped (no displacement speed) or the vehicle speed is very low, for example less than 2 km / h.

  The above conditions may include a driver stepping on a brake pedal.

  When these conditions are met, the computer 28 provides an instruction to stop the engine 10, thereby stopping the engine 10 with a response time typically less than 1 second. This time is sufficient to look for the previously determined biting point and to determine a new biting point.

This is basically done by the following work.
Control the clutch E to close gradually.
-Detecting the start of rotation of the input shaft 14 of the gearbox;
-Record the corresponding position of the movable element of the actuator 24;
-Release the clutch again.

  For this purpose, a position sensor 30 is provided on the movable element of the actuator 24, and a rotational angular velocity position or a rotational angular velocity sensor 32 is provided on the input shaft 14 of the gear box.

  The detection of the biting point (engagement time) of the clutch E is executed without changing the stop condition of the engine 10 by a device for automatically stopping and restarting the engine. If the time from the engine stop command to the actual engine stop is too short to determine the clutch biting point, as already mentioned, and this determination has already begun, Such determination is interrupted and the actuator is returned to its original position. This suspension is of higher priority than ongoing decisions.

  As a modification, the engine stop may be delayed by, for example, about 1 second so that the determination of the biting point can be completed.

  If the rotational speed of the gearbox input shaft 14 does not return to the value 0 sufficiently quickly during the time from the stop command until the engine actually stops, the clutch box E is partially closed so that the gearbox input Braking the shaft 14 and then detecting the biting point of the clutch E can be performed when this speed is sufficiently reduced.

  FIG. 2 shows the main operation in the control method of the present invention.

Given the instruction to stop the engine 10 by the device for automatically stopping and restarting, indicated at 34, whether a predetermined number of conditions are met, including: Verification is performed to confirm.
Verification 36 that the gearbox 16 is in the neutral position and that the clutch E is open.
Verification 38 that the gearbox input shaft 14 is at zero rotation or substantially zero rotation.
-Verification 40 that the speed of the car is zero or very low (verification that the brake pedal is depressed as an option).
Verification 42 that the engine output shaft 12 is rotating at a speed greater than the minimum value.
Verification 44 of looking for previously determined biting points.

  If these conditions are met, the clutch E biting point determination 46 controls the actuator 24, detects the rotation of the input shaft 14 of the gearbox, records the position of the movable element of the actuator 24, and then Open the clutch again.

  The next operation 48 is to actually stop the car engine 10, which is followed by an engine restart 50 by the device 26 when the driver intends to restart the car.

  It is also possible to determine the biting points under other conditions, for example, cold start of the engine, when the engine is stopped by the driver, or all or part of the stop operation by the stop-and-go device.

  The stop action to perform such a determination is a predetermined parameter, such as the elapsed time or the distance traveled since the previous determination, the number of clutch actuations or the engine temperature (due to thermal expansion, the fluctuation of the biting point Can be determined according to the temperature rise).

  The present invention can be implemented with a clutch that may or may not include an internal system to compensate for wear caused by friction, and in the former case, for example, via a diagnostic system accessible to repair personnel. By providing information, it is possible to monitor the proper operation of the system to compensate for wear.

1 is a schematic diagram showing a control system according to the present invention. It is a flowchart which shows the outline | summary of the various operation | movement in the control method concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Internal combustion engine 12 Output shaft 14 Input shaft 16 Gear box 18 Output shaft 20 Drive wheel 22 Differential gear 24 Actuator 26 Stop and go device 28 Computer E Clutch

Claims (12)

Controlling the vehicle, including a clutch (E) actuated by an actuator (24) and a device (26) for automatically stopping and restarting the engine under predetermined conditions including a neutral position of the gearbox In a method for
When the engine (10) is instructed to stop by the device (26), the biting point of the clutch (E) is determined during a time prior to stopping the engine (10) of the automobile. How to control a car.   The method of claim 1, comprising determining a biting point of the clutch (E) each time the engine (10) is commanded by the device (26).   The biting point is determined for only a part of the stopping operation according to a parameter, for example, the distance traveled, the time elapsed since the previous determination, the number of clutch operations, or the change in engine temperature. The method according to claim 1 or 2.   4. The method according to claim 1, wherein the position of the biting point of the clutch (E) is detected by detecting the rotation of the input shaft (14) of the gearbox of the motor vehicle.   5. The position of the movable element of the actuator (24) of the clutch (E) is detected and recorded when the position of the movable element corresponds to a biting point of the clutch. The method described in 1.   When the rotational speed of the engine (10) is equal to or higher than a predetermined minimum value, the clutch (E) started from the open position is gradually closed to detect the biting point of the clutch (E). The method according to any one of claims 1 to 5.   By partially closing the clutch (E), the rotation of the output shaft (14) of the gearbox is slowed down, then the clutch is released, and the clutch is gradually closed to close the clutch. 7. The method of claim 6, wherein a ting point is detected.   8. A method according to any preceding claim, wherein the pre-recorded value of the biting point is looked up before performing a new determination of this biting point at the predetermined time.   9. The method according to claim 1, wherein after the biting point is determined, the clutch (E) is released again during the time prior to stopping the engine.   If the time is too short to make this determination, the determination of the clutch biting point is prohibited, or the determination is interrupted if a stop occurs before the determination is finished. The method according to claim 1. A system for controlling an automobile by executing the method according to any one of claims 1 to 10,
Means (36, 28) for detecting and recording the position of the movable element of the actuator (26) acting on the clutch (E) of the vehicle;
Means (32) for detecting the rotation or rotational speed of the input shaft (14) of the automobile gearbox;
It is connected to the device (26) for automatically stopping and starting the detection means and the engine, and controls the actuator (24) in the closing direction of the clutch, and by the device (26) During the time prior to the commanded engine (10) shutdown, the actuator is movable in response to the start of rotation of the input shaft (14) starting from substantially zero rotation of the input shaft (14) of the gearbox. Means (28) for processing information programmed to record element positions
And a system for controlling an automobile.   12. System according to claim 11, characterized in that the clutch (E) comprises means for compensating for wear.

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