EP1651864A1

EP1651864A1 - Method for starting the engine of a vehicle

Info

Publication number: EP1651864A1
Application number: EP04738615A
Authority: EP
Inventors: Volker Gandert
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2003-07-28
Filing date: 2004-06-04
Publication date: 2006-05-03
Also published as: JP2007500300A; US7717076B2; US20070284944A1; CN1813126A; WO2005015006A1; DE10334242A1

Abstract

The invention relates to a method for starting the engine (5) of a vehicle (1), whereby it is ensured that a stationary vehicle cannot be moved unintentionally during the starting process. When the vehicle is to be started, it is checked to see if it is stationary, and if the vehicle (1) is stationary, at least one vehicle brake (10) is activated. Once the vehicle brake (10) has been activated, the engine (5) can be started.

Description

Method for starting an engine of a vehicle

State of the art

The invention is based on a method for starting an engine of a vehicle according to the preamble of the main claim.

In the vast majority of passenger cars, the engine is started by the driver brings the key of the ignition lock in a starting position and holds there until the engine is started. If the driver releases the key, the starter is deactivated immediately. It is up to the driver to hold the ignition key in the starting position until the engine starts up on its own or the starting procedure is to be aborted.

For reasons of comfort, a so-called automatic start function has been integrated in some vehicles, in which the driver briefly taps either a start button or the starting position of the ignition and automatic control activates the starter until the engine starts up on its own. The problem with this is that in such an automatic starting process, this starting process can not be canceled if, for example, persons appear in front of the vehicle and the transmission is not idling or has not disconnected the clutch.

Advantages of the invention

The method according to the invention for starting an engine of a vehicle with the features of the main claim has the advantage that, in the case of a start request, it is checked whether the vehicle is stationary that at least one vehicle brake is present when the vehicle is stationary. se is activated and that after activation of the vehicle brake, the start of the engine is released. This prevents the vehicle from moving inadvertently during an automatic starting process. In this way, the driving safety is increased in particular when people appear in front of the vehicle during an automatic starting process.

The measures listed in the dependent claims advantageous refinements and improvements of the main claim method are possible.

It is particularly advantageous if, after an engine run-up, the at least one vehicle brake is released again. In this way, the vehicle can be moved as desired by the driver after the start.

It is also advantageous if, after the start of the engine has been released, the engine is started automatically. In this way, an automatic engine start is possible without the risk of unintentional rolling of the vehicle takes place.

Another advantage is that, in the event that after a predetermined time since the start of the request or a start request associated therewith no start release, an automatic start of the engine is excluded. In this way, an automatic start of the engine is prevented even if a start release too long fails, for example, due to a faulty activation of the at least one vehicle brake or a faulty enable signal after the expiration of the predetermined time. Thus, the driving safety can be increased again.

It is also advantageous if the start is only released when it is determined that a drive of the vehicle is disconnected from the engine. In this way, it is likewise prevented that the vehicle unintentionally starts moving when starting, wherein in addition the at least one vehicle brake is spared, since the vehicle is idling anyway, for example.

The corresponding advantage arises when the start is only released when it is determined that a clutch of the vehicle is operated. In this case, too, it is prevented that the vehicle unintentionally starts to move when starting, wherein in addition the at least one vehicle brake is spared. An advantage also results if, in the event that the vehicle is not stationary, the start of the engine is released. In this way, for the case in which the vehicle is already rolling an automatic starting process is not prevented, since in this case can be expected that the driver would like to initiate the automatic start despite the rolling of the vehicle, so the roles is not unintentional and the driver can estimate and also reckons that this rolling motion does not endanger the driving safety.

drawing

An embodiment of the invention is illustrated in the drawing and explained in more detail in the following description.

1 shows a block diagram of a vehicle and Figure 2 shows a flowchart for an exemplary sequence of the inventive method.

Description of the embodiment

In Fig. 1, 1 denotes a vehicle driven by a motor 5. The engine may, for example, be an internal combustion engine or an electric motor or an engine based on an alternative drive concept. in case of an

Internal combustion engine may be, for example, a gasoline engine or a diesel engine. The vehicle 1 comprises an engine control unit 20 and a control unit 30 for controlling at least one vehicle brake 10. The control unit 30 may be, for example, a control unit for an anti-lock braking system and / or a vehicle stability system. Further, if necessary, a transmission control 25 is provided. The engine control 20, the control unit

30 and the transmission controller 25 may exchange information and / or commands with each other via a communications system 60, which may be a GAN bus, for example. Alternatively, the engine control unit 20, the control unit 30 and the transmission control 25 can also be implemented in terms of functionality in a common control unit software and / or hardware and via corresponding communication lines with each other

Exchange information and / or commands. The vehicle 1 further includes a start switch 50 which is connected to the engine controller 20 and outputs a starter request to the engine controller 20 when actuated. The starting switch 50 may be designed, for example, as a starter lock or as a start button. The engine controller 20 is further connected to a starter 45. In response to a control signal of the engine controller 20, the starter 45 starts the engine 5 of the vehicle 1. On the engine 5, an engine speed sensor 40 is arranged, which the Engine speed of the motor 5 detected and transmits to the engine controller 20. Furthermore, a detection unit 15 is provided, which detects in the case of an automatic transmission, the set speed of the automatic transmission and in the case of a manual transmission actuation of the clutch. The vehicle 1 further comprises a wheel speed sensor 35, which is connected to the control unit 30 and tells the control unit 30 whether the vehicle 1 is standing or rolling. The control unit 30 controls at least one vehicle brake 10.

According to the invention, it is now provided that, upon actuation of the start button or when turning the ignition key in the ignition starter lock to the start position, a start release request is generated by the engine control unit 20 and transmitted to the control unit 30 via the communication system 60. By evaluating the wheel speed sensor 35, the control unit 30 then checks whether the vehicle is stationary. In this case, the controller 30 causes the at least one vehicle brake 10 to lock the vehicle 1 and notifies the engine controller 20 of the release for the start. On the other hand, if the control unit 30 determines that the vehicle is rolling by evaluating the wheel speed sensor system 35, it directly issues the start release to the engine control unit 20 without brake activation. Before initiating the start, it may additionally be provided that the engine control 20 checks by querying the transmission control 25 whether the drive of the vehicle is disconnected from the engine 5. For this purpose, the transmission control 25 evaluates the detection unit 15. In the case of an automatic transmission, this takes place in that the detection unit 15 checks whether the gear position "P" or "N" has been engaged, the vehicle 1 thus being in the position

Parking position or idle and thus the drive of the vehicle 1 is separated from the engine 5. If one of the aforementioned driving steps different driving position is engaged, the detection unit 15 detects that the drive of the vehicle 1 is connected to the motor 5. In the case of a manual transmission, the detection unit 15 may be formed as a clutch switch or - sensor and detects whether the clutch is actuated. If this is the case, then that is

Motor 5 disconnected from the drive of the vehicle, otherwise the motor 5 is connected to the drive of the vehicle. If the start release is provided by the control unit 30 and, optionally, the engine 5 is additionally disconnected from the drive of the vehicle 1, then the engine control 20 causes the starter 45 to perform an automatic starting operation, characterized in that the start of the engine 5 of the vehicle 1 is delayed an initial operation of the start button or after an initial operation of the ignition key without further operation of the driver is automatically continued. After the engine startup, which is detected by means of the engine speed sensor 40 after exceeding a predetermined speed threshold, the starter 45 is deactivated and the start release request of the engine controller 20 against the control unit 30 withdrawn, so that the control unit 30 can solve the at least one vehicle brake 10 and go to normal operation. If after a predetermined time since the driver's start request or the actuation of the starter switch 50 or since generation of the start release request by the engine control unit 20 associated with the driver's request to start, no start release by the control unit 30 occurs, for example because the control unit 30 is defective or the communication between the engine controller 20 and the controller 30 via the communication system 60 is interrupted, the engine controller 20 switches to a conventional start. The starter 45 is activated only as long as the driver pressed the start button or keeps the ignition key in the starting position. Thus, the driver can immediately stop the starting process when the

Vehicle unintentionally sets in motion.

The method according to the invention is explained below by way of example with reference to the flowchart according to FIG. After the start of the program, the start switch 50 is actuated by the driver at a program point 100. Subsequently, a branch is made to a program point 105.

At program point 105, the engine controller 20 detects the actuation of the starter switch 50, and thus the presence of a start request, and generates the start enable request and forwards it to the controller 30 via the communication system 60. In FIG. 2, this is

Communication system 60 shown as an interface between the engine controller 20 and the control unit 30, wherein the left of the interface 60 shown portion of Ablauφlan in the engine controller 20 and the right of the interface 60 shown part of the flowchart in the control unit 30 runs. From program point 105 in the engine control 20, a program point 150 in the control unit 30 is branched.

At program point 150, the control unit 30 queries the wheel speed sensor 35 for a wheel speed of the wheels of the vehicle 1 from. Subsequently, a branch is made to a program point 155.

At program point 155, the control unit 30 checks whether the vehicle 1 is stationary based on the wheel speed signals received by the wheel speed sensor 35. If this is the case, the program branches to a program point 160, otherwise a branch is made to a program point 165.

At program point 160, the control unit 30 causes the at least one vehicle brake 10 to block the vehicle 1 or one or more wheels of the vehicle 1, that is, the min. At least one vehicle brake 10 is activated. Subsequently, a branch is made to program point 165.

At program point 165, the controller 30 causes the formation of a start enable signal and sends it to the motor controller 20. This is to a program point 135 in the

Motor control 20 branches. In addition, program point 165 also branches to a program point 170 in control unit 30. At program point 170, the controller 30 checks whether the start enable request of the engine controller 20 is still present. If this is the case, it is branched back to program point 150, otherwise a branch is made to a program point 175.

At program point 175, the control unit 30 causes the release of the at least one vehicle brake 10 and thus the transition to normal operation. Subsequently, the program is left by the controller 30.

At program point 135, the engine control unit 20 checks whether the controller 30 has received a start release signal via the communication system 60. If this is the case, the program branches to a program point 140, otherwise the program branches back to program point 105 and a new start release request is generated by the engine control unit 20 and sent to the control unit 30.

At program point 140, the engine controller 20 causes the starter 45 to perform an automatic engine start, which runs without further operation of the driver on the starter switch 50. Subsequently, a branch is made to a program point 145.

At program point 145, the engine controller 20 checks, based on the engine speed signal provided by the engine speed sensor 40, whether the engine speed exceeds the predetermined speed threshold, i.e., the engine speed exceeds. H. whether the engine startup is completed and the engine 5 is running on its own. The predetermined speed threshold is chosen so that their achievement represents a stable engine run and thus a completed engine run-up. If the detected engine speed exceeds the predefined speed threshold, a branch is made to a program point 125, otherwise it is branched back to program point 140 and the automatic

Startup continued.

At program point 125, the engine controller 20 causes the starter 45 to turn off, thereby initiating start enable request and sending appropriate clear information the control unit 30, which then at program point 170 decides "no" and branches to program point 175. After program point 125, a branch is made to a program point 130.

At program point 130, the vehicle 1 is operated by the engine controller 20 in normal operation, i. H. the starting phase has been completed or canceled. Subsequently, the program is left by the engine controller 20.

From program point 105, the engine control unit 20 also branches to a program point 110.

At program point 110, the engine control unit 20 checks whether a predetermined time has elapsed since the presence of a start request or since the start release request was generated, without a start release signal being received from the control device 30, for example because the control device 30 is defective or the communication between the Motor controller 20 and the

Control unit 30 is interrupted via the communication system 60. If this is the case, the program branches to a program point 115, otherwise it branches back to program point 105 and the start release request is sent again to the control unit 30. The predetermined time can be selected such that the time required for the transmission of the start release request to the control unit 30, the local generation of the start enable signal and the sending of the start enable signal to the motor control 20 in the predetermined time at least once and at most for example two - or three times included. Of course, the required period of time may also be included more frequently in the given time. However, the more frequently the required amount of time is included in the given time, the longer the starting process can take. The specified time should therefore be chosen so that it can still be accepted by the driver as possible.

At program point 115, the engine controller 20 causes the starter 45 to start the engine 5. Then, a program point 120 is branched.

At program point 120, the engine controller 20 checks whether the start switch 50 is still actuated. If this is the case, then branched back to program point 115 and the motor controller 20 causes the starter 45 still to start the engine 5. Otherwise, branched to program point 125 and the motor controller 20 causes the starter 45 to cancel the startup process. In this way, the conventional starting operation is realized, in which during the entire starting process, the driver must press the start switch 50 to the Motor 5 to start successfully.

Before activating the automatic starting process at program point 140, the engine control unit 20 can query the transmission control 25 via the interface 60 or the communication system 60 as to whether the detection unit 15 has detected a separation between the drive of the vehicle 1 and the engine 5, for example Reason for the operation of a clutch of the vehicle. It may be provided, only in this case the separation between the motor 5 and the drive of the Falirzeugs 1 to enable the automatic starting process by the engine control 20 and otherwise to prevent the automatic starting process. This additional query of the separation between the motor 5 and the drive of the Falirzeugs

1 is not necessarily required for safety reasons, because the start enable signal is generated by the controller 30 only when the at least one vehicle brake 10 has been activated. Nevertheless, the stress on the at least one vehicle brake 10 is spared by the separation between the engine 5 and the drive of the vehicle 1.

Of course, before the initiation of the automatic starting process, one or more further conditions known to the person skilled in the art for the starting process can be checked by the engine control 20 and the automatic starting process can only be initiated if all the starting conditions to be checked are met. Furthermore, in addition to the activation of the starter 45, the engine control unit 20 can also provide further information to the person skilled in the art

Initiate measures for the engine start, for example, the construction of fuel pressure, if the engine 5 is designed as an internal combustion engine or the determination of the current crank angle position.

According to the invention, therefore, the wheel speed information is checked by the control unit 30 as to whether the vehicle 1 is stationary. The control unit 30 activates the at least one vehicle brake 10 if it is ensured that the vehicle 1 does not move before the engine is started and thus prevents the vehicle 1 from unintentionally rolling during the starting process. If necessary, the engine 5 is blocked when the transmission is not idling. If the blocking of the engine 5 is to be prevented in order to avoid wear, it can be checked by the engine control unit 20 in addition to the presence of the start release signal from the control unit 30 as to whether the engine 5 is disconnected from the drive of the vehicle 1, that is, for example idling , The automatic starting process is then initiated only when both the enable signal from the controller 30 and the separation between the engine 5 and the drive of the vehicle 1 were detected. If the vehicle 1 but already at the time the start request of the driver, so the operation of the starter switch 50 and thus the start release request of the engine controller 20 rolls, the automatic starting operation is released without brake intervention by the control unit 30. Thus, an already rolling vehicle can be started without bringing it to a standstill.

The described automatic starting function can be used both on vehicles with automatic transmission and on vehicles with manual transmission. Accidents due to unintentionally moving vehicles are thus reliably avoided even with defective, mechanical transmission between the clutch pedal and the clutch.

An automatic starting process decoupled from the driver can be optimally controlled by the engine control unit 20 and is thus not only more comfortable but also allows functions that enable compliance with the highest demands on exhaust emissions.

Claims

claims

1. A method for starting an engine (5) of a vehicle (1), characterized in that is checked in the case of a start request, if the vehicle (1), that when the vehicle (1) at least one vehicle brake (10) is activated and that after activation of the vehicle brake (10) of the start of the engine (5) is released.

2. The method according to claim 1, characterized in that after a motor run-up the at least one vehicle brake (10) is released again.

3. The method according to any one of the preceding claims, characterized in that after the release of the start of the engine (5) of the engine (5) is started automatically.

4. The method according to any one of the preceding claims, characterized in that an automatic start of the engine (5) is excluded in the event that after a predetermined time since the existence of the start request o- an associated start release request is no start release.

5. The method according to any one of the preceding claims, characterized in that the start is only released when it is determined that a drive of the vehicle (1) from the engine (5) is disconnected.

6. The method according to any one of the preceding claims, characterized in that the start is only released when it is determined that a clutch (15) of the vehicle (1) is actuated. Method according to one of the preceding claims, characterized in that, in the event that the vehicle (1) is not stationary, the start of the engine (5) is released.