DE102014214264A1 - Method for controlling the stopping and starting of an engine - Google Patents

Abstract

A method is disclosed for controlling the stopping and starting of an engine 5 of a motor vehicle 1 with a manual transmission while a transmission of the motor vehicle 1 is in motion, wherein a set of predefined conditions to be met on the respective states of a clutch pedal and brake pedal in FIG based on a previous engine-stopped primary state. There are at least two motor-stopped primary states from which the motor can be started directly and at least two stopped secondary states from which starting the motor is not directly possible. The method adapts the conditions required to start the engine 5 based on how a driver of the motor vehicle operates the clutch and brake pedals while the engine 5 is stopped. In a modification of the method, the engine 5 is not started until an accelerator pedal condition is determined to be depressed, whereby the amount of fuel consumed inefficiently by the motor vehicle 1 is further reduced.

Description

The present invention relates to stopping and starting an engine of a motor vehicle in response to driver actions, and more particularly to an adaptive method of controlling the starting of the engine following an engine stop.

The main task of a stop-start system is to maximize engine shutdown time; therefore, it is desirable to avoid unnecessary or premature engine restarts.

Provided there are no stop locks, such as a climate control request, a battery state of charge request, or an engine operating temperature request, a conventional stop-in-gear (SIG) system initiates an engine stop event when the vehicle is stationary is and the clutch pedal is in the depressed state and the transmission is in gear and the brake pedal is depressed.

When the brake pedal is moved to a non-depressed or released state from an SIG stop event, the engine is immediately restarted.

After stopping the engine, the driver may in some cases release the brake pedal without adversely affecting the safety of the motor vehicle, but then an engine start will occur, although the driver does not wish to drive off.

It is an object of the present invention to provide a method for controlling the stopping and starting of an engine of a motor vehicle that provides more driver flexibility without resulting in inappropriate engine restarts.

According to a first aspect of the invention, there is provided a method of controlling the stopping and starting of an engine of a motor vehicle having a manual transmission, a clutch pedal, and a brake pedal, wherein there are at least two engine-stopped primary conditions from which the engine can be restarted directly, and at least two engine-stopped secondary conditions from which the engine can not be directly started, and the method restarts the engine from one of the engine-stopped primary conditions when the transmission is in the engaged state and a predefined combination of brake pedal. and clutch pedal conditions, wherein the required predefined combination is dependent on the brake pedal and clutch pedal conditions in the engine stopped primary state from which the starting is to occur.

When the clutch pedal state is depressed in the engine-stopped primary state and the brake pedal state is depressed, the predefined combination of states may be continuation of a clutch depressed state and change of brake pedal state depressed to released.

In the stopped state, when the clutch pedal is in a non-depressed state and the brake pedal is in a released state, the predefined combination of states may be the continuation of a brake released state and the change in clutch pedal state from undepressed to depressed.

Further, the method may include restarting the engine only when an accelerator pedal of the motor vehicle is in a depressed state.

According to a second aspect of the invention, there is provided an engine stop-start control system for an engine of a motor vehicle having a manual transmission, a clutch pedal, and a brake pedal that includes an electronic controller, a clutch pedal state detection sensor, and a clutch pedal state supply sensor electronic control signal indicative, a brake pedal state sensor and a brake pedal state indicating signal for electronic control, a transmission engagement detection sensor, and an electronic control signal indicative of the engagement state of the transmission, and means for detecting a transmission Movement of the motor vehicle and for supplying a signal indicative of the movement of the motor vehicle for electronic control, wherein there are at least two motor-stopped primary states, from which the engine through the electronic S can be restarted directly, and at least two engine-stopped secondary states from which the engine can not be started directly by the electronic control, and the electronic controller is operable to restart the engine from one of the engine-stopped primary conditions when the signal from the transmission state sensor indicates that the transmission is in the engaged state, and the signals from the brake pedal and clutch pedal sensors indicate that there is a predefined combination of brake pedal and clutch pedal conditions, with the required predefined combination of the brake pedal and clutch pedal conditions in the engine-stopped-primary state, from which starting is to take place, is dependent.

When the clutch pedal is depressed in the engine-stopped primary state and the brake pedal state is depressed, the predefined combination of states may be the continuation of the clutch-depressed state and the change in brake pedal state from depressed to released.

When the clutch pedal in the engine stopped primary state is in a non-depressed state and the brake pedal is in a released state, the predefined combination of states may be non-depressed from continuing the brake released state and changing the clutch pedal state to be pressed.

The motor vehicle may include an accelerator pedal, and the system may further include a sensor for detecting the state of the accelerator pedal and supplying an accelerator pedal signal indicative of the electronic control, and the electronic controller may be operable to restart the engine only when the signal from the accelerator pedal sensor indicates that the accelerator pedal is in a depressed state.

According to a third aspect of the invention, there is provided a motor vehicle having an engine and a stop-start control system constructed according to the second aspect of the invention.

The invention will now be described by way of example with reference to the accompanying drawings, in which:

1 a schematic diagram of a motor vehicle with an engine stop-start control system according to a second aspect of the invention;

2 a diagram showing various clutch pedal positions and their corresponding states;

3a a detailed flowchart of the first embodiment of a method for controlling the stopping and starting of an engine of a motor vehicle;

3b a first modification of the in 3a shown method; and

3c a second modification of the in 3a shown method.

On 1 Referring to, becomes a motor vehicle 1 with a motor 5 shown, which is in this case a reciprocating internal combustion engine.

The motor 5 is arranged to drive at least one (not shown) road wheel via a (not shown) manual transmission with multiple selectable gears. A driver operable input device is provided in the form of a gearshift lever (not shown) to a driver of the motor vehicle 1 to allow to choose a desired one of the gears of the transmission. A coupling (not shown) is between the engine 5 and the transmission arranged to allow the transmission out of the engine 5 is disengaged. The clutch has an engaged and disengaged condition and is actuated by a driver-operable clutch pedal 8th ( 2 ) served.

The car 1 has a brake system (not shown) that includes a plurality of road brakes and a driver-actuatable (not shown) foot brake pedal for actuating or releasing the road wheel brakes.

The car 1 includes a stop-start control system 10 with an electronic control 11 and several entrances 12 . 13 . 14 . 15 . 16 and 20 by the electronic control 11 used to determine if the engine 5 should be stopped or started.

The first input to the electronic control 11 comes from a clutch pedal sensor 12 , The clutch pedal sensor 12 detects the position of the clutch pedal 8th , The position of the clutch pedal 8th determines the engagement state of the clutch. The clutch pedal condition is used in the example given in this description because it provides a good way to describe the monitoring of the engagement state of the clutch. It will be understood, however, that instead of detecting the clutch pedal position, other means could be used to monitor and provide feedback about the clutch engagement condition.

To make the clutch pedal conditions cited in this specification more understandable, shows 2 the clutch pedal states 'R' (released), 'P' (pressed), 'D' (depressed) and 'ND' (not-depressed). The state transition thresholds of the clutch sensor 12 are calibrated so that the grinding point of the clutch is in the 'depressed' state. That is, when the clutch pedal 8th In the depressed state (D), the clutch is definitely disengaged when the clutch pedal 8th is in the released state (R), the clutch is definitely in the engaged state, and when the clutch pedal 8th is in the depressed state (P), the engagement state of the clutch depending on the position of the grinding point in the range the clutch pedal position defined as 'pressed' and the actual position of the clutch pedal 8th be either indented or disengaged in this 'pressed' area.

For the purposes of the present invention, it is only necessary to determine if the clutch pedal 8th depressed (D) or non-depressed (ND).

The second entry is made by a brake pedal sensor 13 which detects the position of the brake pedal, by means of which the state of the brake pedal can be derived. When the brake pedal is depressed, the road brakes are applied, and when the brake pedal is released, the road brakes are not actuated. It is understood that the brake pedal condition sensor need not detect the actual brake pedal position; for example, it could be derived from the pressure of the hydraulic fluid in the brake system.

The third input is from a transmission state sensor 15 that provides a signal indicating engagement of the transmission. The transmission has two states of operation: a running state when one of the gears of the transmission is in an in-gear state, which is called a gear-engaged state, and a non-running state when none of the gears of the transmission is in one gear , which is called a gear neutral state. The transmission condition sensor 15 can either detect when the transmission is in the engaged state or when it is in the neutral position state, or it can be provided for confirmation purposes sensors for detecting both states.

The fourth input is from a vehicle speed detecting means 16 , which may be in any suitable form, but in this case is a road wheel turning sensor (vehicle speed sensor) which is part of an anti-lock braking system of the motor vehicle 1 is trained.

A fifth input is any other input 20 used to control stopping and starting the engine 5 required, that is, inputs to indicate that there are one or more stop locks. A sixth input required for certain embodiments is an accelerator pedal sensor 14 providing an input indicating whether an accelerator pedal (not shown) of the motor vehicle 1 pressed or not pressed. When the accelerator pedal is depressed, a torque request for the engine becomes 5 is generated, and if the accelerator pedal is not pressed, but released, then the engine 5 operated in an idle mode. It is understood that the fuel supply and the general operation of the engine 5 as usual controlled by a motor control unit (not shown). The electronic control 11 and the engine control unit (ECU) may be separate components of the motor vehicle 1 or could be combined as part of a larger powertrain control unit.

The operation of the stop-start system is as follows.

The electronic control 11 constantly monitors a movement of the motor vehicle 1 via the vehicle speed sensor 16 , the states of the clutch pedal 8th and the brake pedal via their respective sensors 12 and 13 and the state of the transmission via the transmission state sensor 15 ,

When the inputs from the sensors 12 . 13 . 15 . 16 show that the motor vehicle 1 is stationary, the state of the gear is engaged, the clutch pedal 8th is in the depressed state and the brake pedal is in the depressed state, then the electronic control acts 11 to stop the engine 5 ,

The motor 5 then remains in the engine-off or engine-stopped state until a predefined combination of startup conditions by the electronic control 11 is determined as present. The required conditions are not limited to a set of conditions, but vary based on the state of the clutch pedal 8th and the brake pedal during the period during which the engine is running 5 is stopped, and form a number of alternative stopped states that make up the engine 5 is restarted directly at a motor-stopped primary state, or indirectly restarted at a motor-stopped secondary state.

When in the stopped state, the transmission is in an engaged state, the clutch pedal 8th is in a depressed state and the brake pedal is in a depressed state, then the predefined combination of start states that the transmission remains in the engaged state is the clutch pedal 8th remains in the depressed state and the brake pedal state changes from depressed to released. This represents a first example of a transition from an engine stopped primary state to an engine operating state.

If the transmission remains in an engaged state when stopped, the clutch pedal 8th is not in the depressed state and the brake pedal is not depressed but released, then the predefined combination of starting conditions is that clutch pedal 8th is depressed and the state of the brake pedal remains released. This represents a second example of a transition from an engine stopped primary state to an engine operating state.

Since the invention relates to a system for stationary stop in the course, it is understood that in both cases the transmission 5 consistently remains engaged and the motor vehicle 1 essentially remains stationary. If the state of the transmission is changed from engaged to non-engaged during the stopped state, then to control the starting of the engine 5 another set of start conditions (SIN conditions, SIN stop in neutral / stop in neutral position) can be used. The stop-start system 11 It can also control the stopping and starting of the engine 5 If the transmission is not engaged, it may be designed using SIN conditions, but this aspect of its operation forms no part of the present invention and will not be further described.

In addition to the two motor-stopped primary states mentioned above, there are two other motor-stopped states, referred to as motor-stopped secondary states, because it is not possible in such stopped states to drive the motor 5 to start directly. To start the engine 5 From a stopped secondary state, it is first necessary to change to one of the engine-stopped primary states and then to meet the conditions required to transition from the respective engine-stopped primary state to an engine operating state.

By providing alternative engine stopped states, a driver of the motor vehicle is notified 1 greater flexibility. Normally, the driver could not take his feet off the brake and clutch pedal, as releasing the brake pedal the engine 5 would be started. However, by providing alternative secondary conditions in which no engine starting occurs, it is possible to allow the driver to release the clutch pedal and then the brake pedal without the engine 5 to start. The driver can then take both feet off the pedals during a longer engine stop.

In some circumstances, the driver may effect the required predefined combination of brake and clutch pedal changes from an engine stopped primary state before the motor vehicle 1 must be moved. That is, the driver can prematurely release the brake pedal or depress the clutch pedal prematurely. The result of such actions is a waste of fuel by the engine 5 is started to idle unnecessarily. That's why the electronic control could 11 be designed and operable to delay a start until the signal from the accelerator pedal sensor 14 indicates that the accelerator pedal is pressed.

Now on 3a Referring to Fig. 1, a method of controlling the stopping and starting of the engine will be described 5 of the motor vehicle 1 shown by the electronic control 11 is used to control the stopping and starting of the engine while the transmission of the motor vehicle 1 engaged (in progress) is.

The procedure starts in box 100 where the engine 5 and, assuming there is no key-off event, will continue to do so until predefined engine-off conditions are met. The predefined engine-off conditions are that the motor vehicle 1 is stationary, the transmission is engaged, the clutch pedal state is depressed and the brake pedal state is depressed. If all of these conditions are present, then the engine is stopped, as in box 110 shown, otherwise the engine is running 5 further.

In box 110 is the engine 5 in a first engine stop state in which the transmission state is engaged, the clutch pedal state is depressed, and the brake pedal state is depressed. This is an engine-stopped primary state. Out of the box 110 The first engine stopped state shown becomes the engine 5 restarted directly when the transmission remains in the engaged state, the clutch pedal state remains depressed and the brake pedal state changes from depressed to released, such as through the boxes 112 and 120 shown.

Out of the box 110 The first engine stopped state shown becomes the engine 5 however, not restarted when the transmission remains in the engaged state, the clutch pedal is no longer depressed and the brake pedal state remains depressed, but instead enters a second engine stopped state, which is an engine-stopped secondary state like through the boxes 115 and 130 shown.

In the second engine-stopped state, in the box 130 is shown, the transmission state is engaged, the clutch pedal state is not depressed and the brake pedal state is depressed. If the clutch pedal condition changes from non-depressed to depressed in the second engine-stopped state, the process returns to the first engine-stopped condition, such as through the boxes 118 and 110 shown.

However, when the brake pedal state is in the second engine stopped state 130 from pressed to released changes as by box 132 then the procedure moves to box 140 representing a third engine stopped state, which is a motor stopped primary state. Therefore, the engine can not be directly started from the second engine stop state, it can be started only when the stopped state is changed to a stopped primary state.

In the third engine-stopped state 140 when the brake pedal state is released, the transmission state is engaged, and the clutch pedal state is not depressed.

When the brake pedal state remains released, the transmission state remains engaged, and the clutch pedal state changes from the non-depressed state to the depressed state, then the engine becomes 5 immediately restarted, as through the boxes 142 and 150 shown.

However, if the clutch pedal condition remains non-depressed, the transmission state remains engaged, and the brake pedal condition changes from released to depressed, then the engine becomes 5 instead of starting, the method instead advances to a fourth engine stopped state, such as by boxing 145 and 160 shown. The fourth engine-stopped state is a motor-stopped secondary state because it is not possible to the engine 5 to start directly from this suspended state.

In the fourth engine stopped state 160 becomes the engine 5 then, when the clutch pedal state is not depressed, the transmission state remains engaged and the brake pedal state changes from depressed to enabled, not started, but instead the process returns to the third engine stopped state 140 back, like through the box 148 shown.

However, if the brake pedal state remains depressed, the transmission state remains engaged, and the clutch pedal state changes from the non-depressed state to the depressed state, the process returns to the fourth engine stopped state 160 in the first engine-stopped state 110 back, like through the box 162 shown.

Therefore, the engine can not be directly started from the fourth engine stop state, it can be started only when the stopped state is changed to a stopped primary state.

The conditions required to start the engine 5 depend on the respective states of the clutch pedal and the brake pedal during the engine stopped state, and since the driver may apply the brake and clutch pedal while the engine is stopped, more than one clutch and brake state change combination will occur provided to restart the engine 5 to enable.

3b shows a first modification of the in 3a shown method, which in most points with the in 3a shown method is identical and will not be described again in detail.

The only difference to that in 3a shown method is that the method of box 112 only then to box 120 where the engine 5 is restarted, advances when the state of the accelerator pedal is depressed, as by box 114 shown.

• a/ Getriebezustand bleibt eingerückt; und
• b/ Kupplungspedalzustand bleibt niedergedrückt; und
• c/ Bremspedalzustand ist freigegeben; und
• d/ Fahrpedalzustand ist gedrückt.

It is understood that this requirement for having an accelerator pedal depressed state with the in box 112 cited requirements, that is, boxes 112 and 114 in 3b could be through a single box (not shown) 112 ' to be replaced with the predefined combination: -

• a / gear state remains engaged; and
• b / clutch pedal condition remains depressed; and
• c / brake pedal condition is released; and
• d / accelerator pedal is depressed.

3c shows a second modification of the in 3a shown method, which in most points with the in 3a shown method is identical and will not be described again in detail.

The only difference to that in 3a shown method is that the method of box 142 only then to box 150 where the engine 5 is restarted, advances when the state of the accelerator pedal is depressed, as by box 144 shown.

• a/ Getriebezustand bleibt eingerückt; und
• b/ Kupplungspedalzustand bleibt niedergedrückt; und
• c/ Bremspedalzustand ist freigegeben; und
• d/ Fahrpedalzustand ist gedrückt.

It is understood that this requirement for having an accelerator pedal depressed state with the in box 142 cited requirements, that is, boxes 142 and 144 in 3b could be through a single box (not shown) 142 ' to be replaced with the predefined combination: -

• a / gear state remains engaged; and
• b / clutch pedal condition remains depressed; and
• c / brake pedal condition is released; and
• d / accelerator pedal is depressed.

It is understood that the two in the 3b and 3c disclosed modifications could be used with favorable effects in the same system and in such a combination for a second embodiment of a method for controlling the starting and stopping of an engine of a motor vehicle.

In short, therefore, it is accepted that in an SIG stop event, when the clutch pedal is moved to a non-depressed state, it is not appropriate to restart the engine because the transmission is in gear (engaged) and the clutch discs could lead to unintentional vehicle movement. Restart trip conditions from this condition that maximize engine-off duration by preventing unnecessary engine restarts are desirable. Furthermore, restart trigger conditions should take into account how intuitive the behavior of the system is for the driver and continue to provide the driver with the most appropriate set of actions that must be taken throughout the SIG stop and restart event.

It is important for a vehicle manufacturer to define possible use cases so that he can provide a system that maximizes fuel economy while preventing engine restarts that occur when the driver requires no torque and that can lead to unwanted vehicle motion or one detrimental impression on the driver.

For example, by accident or active effort, a driver may find useful or minimal cost stop and restart applications that a conventional SIG system normally does not do. These use cases might initially be considered 'abuse cases' and their use may not be expected in normal operation. Such unexpected behavior could have consequences in terms of achieving lifetime goals or have unexpected consequences in terms of reduced starting power and torque availability. For example, when the driver releases the clutch pedal and then the brake pedal following an SIG stop event, the vehicle is suitably prevented from rolling forward or backward because the engine is connected to the wheels via the transmission and the vehicle is in the vehicle Transmission is in the engaged state. Therefore, the driver does not have to depress the brake pedal to keep the vehicle stationary during the stop, and may conveniently take both feet off the pedals during a prolonged engine stop. Consideration of such a use case and its inclusion in the functionality of the stop-start control system that can be achieved by implementing a stop-start control system according to the present invention is important.

It will be obvious to those skilled in the art that while the invention has been described by way of example with reference to one or more embodiments, it is not limited to the disclosed embodiments and alternative embodiments could be practiced without departing from the scope of the invention as it is is defined by the appended claims.

Claims (12)

A method of controlling the stopping and starting of an engine of a motor vehicle having a manual transmission, a clutch pedal, and a brake pedal, wherein there are at least two engine-stopped primary conditions from which the engine can be directly restarted, and at least two engine-stopped secondary conditions, and the method of restarting the engine from one of the engine-stopped primary conditions when the transmission is in the engaged state and having a predefined combination of brake pedal and clutch pedal conditions, the required predefined combination from the brake pedal and clutch pedal conditions in the engine-stopped-primary state from which the starting is to take place. The method of claim 1, wherein when the clutch pedal condition is depressed in the engine-stopped primary state and the brake pedal condition is depressed, the predefined combination of conditions is to continue a clutch depressed state and to change the brake pedal state from depressed to released. The method of claim 1, wherein when in the stopped state, the clutch pedal is in a non-depressed state and the brake pedal is in a released state, the predefined combination of states, the continuation of a brake released state and the change of the clutch pedal state of not depressed is too depressed. The method of one of claims 1 to 3, wherein the method further comprises restarting the engine only when an accelerator pedal of the motor vehicle is in a depressed state. Engine stop-start control system for an engine of a motor vehicle with a A manual transmission, a clutch pedal and a brake pedal, the system comprising an electronic control, a sensor for detecting the state of the clutch pedal and the supply of a signal indicative of the clutch pedal state to the electronic control, a sensor for detecting the brake pedal state and for supplying a brake pedal state indicating signal to electronic control, a sensor for detecting the engagement state of the transmission and for supplying an engaging state of the transmission indicative signal to the electronic control and means for detecting a movement of the motor vehicle and for supplying a signal indicative of the movement of the motor vehicle for electronic control, at least two motor-stopped primary states from which the engine can be restarted directly by the electronic control, and at least two engine-stopped secondary states from which the engine through the ele ktronische control can not be started directly, and the electronic control is operable to restart the engine from one of the engine-stopped primary states when the signal from the transmission state sensor indicates that the transmission is in the engaged state, and the Signals from the brake pedal and clutch pedal sensors indicate that there is a predefined combination of brake pedal and clutch pedal conditions, with the required predefined combination of the brake pedal and clutch pedal conditions in the engine stopped primary state to be from startup. The system of claim 5, wherein when the clutch pedal condition is depressed in the engine-stopped primary state and the brake pedal condition is depressed, the predefined combination of conditions is continuation of the clutch depressed state and the brake pedal condition is depressed to de-energized. The system of claim 5, wherein when the clutch pedal is in the non-depressed state and the brake pedal is in a released state in the engine stopped primary state, the predefined combination of states is continuation of the brake released state and the change of the clutch pedal state from non-depressed to depressed. The system of any one of claims 5 to 7, wherein the motor vehicle includes an accelerator pedal and the system further comprises a sensor for detecting the state of the accelerator pedal and supplying an accelerator pedal signal indicative of electronic control and the electronic controller is operable to drive the engine only to be restarted when the signal from the accelerator pedal sensor indicates that the accelerator pedal is in a depressed state. Motor vehicle with a motor and a stop-start control system according to one of claims 5 to 8. A method of controlling the stopping and starting of an engine of a motor vehicle substantially as described herein with reference to the accompanying drawings. An engine stop-start control system for an engine of an automotive vehicle substantially as described herein with reference to the accompanying drawings. Motor vehicle, substantially as described herein with reference to the accompanying drawings.

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