DE102014104292A1 - Method and arrangement for operating a motor vehicle with internal combustion engine and automatic transmission - Google Patents

Abstract

The invention relates to a method for operating a motor vehicle with an internal combustion engine and automatic transmission, wherein the internal combustion engine is controlled between idle gas and full throttle and has a minimum speed and a maximum speed, the automatic transmission has different ratios for propulsion of the motor vehicle, which can be controlled between a shortest and a longest gear are provided, and an accelerator pedal for driving the internal combustion engine and the automatic transmission, which is adjustable between a zero position and a maximum position, wherein the momentarily demanded on the internal combustion engine power is detected and the automatic transmission switches to a longer gear, if at a resulting engine speed greater the minimum speed the determined power with a correspondingly increased throttle position kleinergleich full throttle is reached, wherein the upshift without changing the position of the accelerator pedal, the increased throttle is set for the internal combustion engine. Furthermore, the invention relates to an arrangement for operating a motor vehicle with an internal combustion engine and automatic transmission.

Description

The invention relates to a method and an arrangement for operating a motor vehicle with an internal combustion engine and automatic transmission, wherein the internal combustion engine is controlled between idle gas and full throttle and has a minimum speed and a maximum speed, the automatic transmission has different ratios for propulsion of the motor vehicle, between a shortest and a longest gear are controllable, and an accelerator pedal for driving the internal combustion engine and the automatic transmission is provided, which is adjustable between a zero position and a maximum position.

Motor vehicles with internal combustion engine and automatic transmission have been known for many years. Modern vehicles have an engine control unit that controls the control of the engine in response to commands given by the accelerator pedal. Furthermore, the automatic transmission to an automatic transmission control unit, with which the choice of the supposedly correct gear (gear ratio) takes place in dependence on the present on the engine control unit control commands. It should be noted that in the known internal combustion vehicles with automatic transmission via the accelerator pedal controls the control of the fuel supply to the engine and the automatic transmission is controlled in dependence on the control of the engine. As a result, a non-optimal control of the entire system is achieved, whereby an unnecessarily high fuel consumption is observed.

The object of the invention is to control the combination of internal combustion engine and automatic transmission in a motor vehicle for further fuel economy smarter.

This object is achieved by the method illustrated in claim 1 and the arrangement shown in claim 9.

Due to the fact that the currently demanded on the engine power is detected and the automatic transmission switches to a longer gear when at a resulting engine speed greater than the minimum speed the determined power with a correspondingly increased throttle position kleinergleich full throttle is reached, with the upshift without changing the position of the Accelerators the increased throttle position is set for the engine, a very economical driving is made possible in which the automatic transmission as long a gear is selected, namely that gear in which the engine just the requested performance at relatively low speed, but relatively high throttle position he brings.

If the increased throttle position for the internal combustion engine is adjusted during upshifting without changing the position of the accelerator pedal, the system will also be switched without force jump. This results in a very uniform propulsion.

According to the device, the object is achieved in that a central control unit is provided to which the accelerator pedal, the engine control unit and the automatic transmission control unit are connected, wherein the maximum achievable engine performance depending on the speed as well as the transmission gradations are stored in the central control unit.

The special feature is that the accelerator pedal is no longer directly connected to the fuel supply (gas position on the internal combustion engine), but that the position of the accelerator pedal corresponds to a certain, requested at the combustion engine power. The accelerator pedal should therefore be called accelerator pedal, with which the power of the engine from 0% to 100% can be controlled. To save fuel, it comes in that the lowest possible engine speed on the automatic transmission and the corresponding control (throttle position of the engine) is selected for the internal combustion engine to the applied power at the applied power can still be achieved, although thus a relative high gas position is set on the internal combustion engine.

By downshifting, when the internal combustion engine is operated at full throttle and more power is requested by further depression of the accelerator pedal, wherein when downshifting without changing the position of the accelerator pedal, a reduced throttle position is set for the internal combustion engine, is reversed at a requested higher power than the one that is just achievable at the selected gear of the automatic transmission causes a downshift. But here is the special feature that in this case, a change in the position of the accelerator pedal also does not occur, but when downshifting automatically a reduced throttle position for the engine is set, that is switched in this reverse direction also zugerkraftsprungfrei.

If, with the adjustment of the accelerator pedal, the power of the internal combustion engine is controlled with the lower power range spread over the pedal travel, a much more accurate and sensitive control can be performed by the driver in the area where relatively little engine power is required. The spread can be a percentage spread, an exponential or a logarithmic spread.

In a further development, the assignment of the power selected by the pedal position to the pedal position is adjusted dynamically, wherein the range is spread around the currently selected on the accelerator pedal power, so that the spread range of the accelerator pedal adjusts each of the currently selected power range, which means that a sensitive Speed adjustment is facilitated by the driver.

When a pedal back pressure is actively generated on the accelerator pedal upon actuation depending on the currently measured or the calculated acceleration, the acceleration and thus the load situation that is currently acting are made more noticeable to the driver for the automatic transmission-internal combustion engine combination.

By maintaining the current gear at abrupt return to the neutral position or downshifting at low engine speeds, upshifting is avoided by the automatic transmission in the event of sudden load loss, as this usually occurs when braking is desired soon. By avoiding the upshift, the higher engine speed acts as a supplemental engine brake to reduce the speed of the motor vehicle.

The fact that in dynamic driving with much accelerator pedal movement is only switched to a higher gear, when in this the currently requested power can be achieved multiplied by a dynamic factor, the dynamic factor between 1.05 and 2.0, in particular 1.1 to 1 , 5 is too early upshifting and thus too slow driving behavior can be avoided. With the proposed dynamic factor between 1.05 and 2.0 is thus switched to a higher gear, if there is a power surplus of 5% to 100% predetermined. Preferably, the dynamic factor is limited to a range of 10% to 50% power surplus.

In a further embodiment, the dynamic factor to be applied is adapted as a function of the accelerations determined over a predetermined period of time. Thus, the driving style of the driver of the motor vehicle is determined over the predetermined period of time and evaluated on the basis of acceleration values and slidably applied in accordance with the dynamic factor to be applied, for example, in a range of 1.1 to 1.5. This application allows a more dynamic driving, as always a power reserve for a spontaneously requested acceleration is available.

The invention will be described with reference to the accompanying drawings in an embodiment.

It shows:

1 in a schematic diagram of the arrangement of the components in a motor vehicle.

In 1 is a motor vehicle 1 with four indicated wheels 11 shown in a schematic diagram. The car 1 has an internal combustion engine 2 on top of a powertrain 22 its torque on an automatic transmission 3 transfers. From the automatic transmission 3 are simplified via drive shafts 32 two wheels 11 of the motor vehicle 1 driven.

The internal combustion engine 2 is an engine control unit 21 assigned. Likewise, the automatic transmission 3 an automatic transmission control unit 31 assigned.

Furthermore, it is a central control unit 5 provided by an accelerator pedal 4 from the driver of the motor vehicle 1 given driving commands and via appropriate operative connections to the engine control unit 21 and / or to the automatic transmission control unit 31 forwards.

There are also sensors 6 for detecting the driving conditions of the motor vehicle 1 intended. A sensor for driving speed 61 is at a wheel 11 of the motor vehicle 1 arranged, a sensor for vehicle accelerations 62 is near the center of gravity of the motor vehicle 1 arranged and a sensor for the engine speed 63 is on the combustion engine 2 arranged. These sensors 6 are via active connections with the central control unit 5 connected.

Hereinafter, the method for operating the motor vehicle 1 with internal combustion engine 2 and automatic transmission 3 based on the embodiment according to 1 described in detail.

The internal combustion engine 2 is via the engine control unit 21 controllable between idling gas and full throttle. In this case, the internal combustion engine 2 a minimum speed, usually also idle speed, and a maximum speed. These speeds are via the motor speed senor 63 from the central control unit 5 detected.

The automatic transmission 3 has various translations or continuously variable transmissions for propulsion of the motor vehicle 1 , So torque connection between the engine 2 and the wheels 11 of the motor vehicle 1 on. It has the automatic transmission 3 one shortest and one longest gear, possibly with further gradations or continuous translation adjustment between these two end positions, via the automatic transmission control unit 31 are controllable.

The gas pedal 5 serves to control the internal combustion engine 2 and the automatic transmission 3 wherein the accelerator pedal is adjustable between an O position and a maximum position.

The special feature of the invention is that a central control unit 5 to adapt the respective speed of the internal combustion engine 2 and the selected translation of the automatic transmission 3 via their assigned control units 21 . 31 upstream. The central control unit 5 controls according to the accelerator pedal 4 applied pedal position and the driving speed, the load of the internal combustion engine 2 and the gear selection in the automatic transmission 3 , This is currently the combustion engine 2 Demanded power detected and the automatic transmission 3 switched to a longer gear when at a resulting engine speed greater than the minimum speed, the determined power with a correspondingly increased from the engine control unit 21 to the internal combustion engine 2 adjusted throttle position is less than or equal to full throttle. This is when upshifting (shifting from a smaller gear to a larger gear) in the automatic transmission 3 the increased throttle position (control by the engine control unit 21 ) for the internal combustion engine 2 without changing the position of the accelerator pedal 4 set. This is done free of stress.

The central control unit 5 thus tries for the desired on the gas pedal 4 requested performance the lowest possible engine speed and a long gear on the appropriate driving the associated engine control unit 21 and automatic transmission control unit 31 to reach.

Thus, the accelerator pedal shows 4 a direct correlation to the requested performance in the motor vehicle 1 , indicating the position of the accelerator pedal 4 only very little with the position of the throttle or the fuel supply to the engine 2 has to do. The gas pedal 4 would therefore better accelerator pedal or power pedals. For better understanding, this power drive is still called accelerator pedal.

In order to be able to control the range of lesser powers, which are sufficient in many driving situations, more sensitively, the power selection from 0% to 100% is not linearly divided, but spread apart in the lower power range via the pedal travel. Thus, a longer pedal travel is available for lower actuated power than for high power. In a further improved embodiment, the spread can also be dynamically adapted to the respective driving situation, so that in a fast highway driving, in which a much higher power is required, the power adjustment is spread in the range of this higher power. Thus, the power setting can in turn be sensitively adapted to the particular desired driving situation.

Is from the driver of the motor vehicle 1 a certain power, for example 25% of full power via the pedal 4 requested, is via the central control unit 5 thus the longest possible gear via automatic control unit 31 in the automatic transmission 3 switched on and at the same time the corresponding lowest possible engine speed via the engine control unit 21 in the internal combustion engine 2 driven. In parallel, without changing the pedal position 4 on the combustion engine 2 via the engine control unit 21 an increased throttle position, so more direction full throttle selected, so that the internal combustion engine 2 at the low engine speed on the pedal 4 provides selected performance.

It has been found that fuel can be saved significantly due to the very low-speed driving.

If now the driving situation changes and the driver in the motor vehicle 1 the gas pedal 4 further depresses, so demanded more power, is checked via the central control unit, whether this extra power by increasing the throttle position by engine control unit 21 on the combustion engine 2 without changing the gear selection on the automatic transmission 3 can be requested. If this is not possible or if by further depressing the accelerator pedal 4 Significantly more power is requested, is when downshifting the automatic transmission 3 by controlling the automatic transmission control unit 31 from the central control unit 5 without changing the position of the accelerator pedal 4 a reduced throttle position, so from full throttle position direction idle gas on the engine control unit 21 on the combustion engine 2 selected. In this case, too, there is a circuit without a jump in force and thus a comfortable adaptation of the powertrain of the motor vehicle train to the desired driving performance that is gentle on the material.

In dynamic driving with a lot of movement on the accelerator pedal 4 , on the one hand, via the gas pedal 4 directly and additionally via the sensor for accelerations 62 registered and sent to the central control unit 5 is reported, is only switched to a higher gear when in this the currently requested power can be achieved multiplied by a dynamic factor, the dynamic factor between 1.05 and 2.0, in particular 1.1 to 1.5 lies. This means that 5% to 100% of the instantaneous power or preferably 10% to 50% of the currently requested power is still possible as a power increase reserve in unchanged gear selection of the automatic transmission. Although this leads to a slightly increased fuel consumption, but allows a short-term acceleration in the specified performance limits, without first the automatic transmission would have to downshift a gear.

In a further preferred embodiment, the dynamic factor to be applied is determined over a predetermined period of time via the sensor for accelerations 62 adjusted accelerations, which is reduced in a more sedate driving the dynamic factor and vice versa in a more dynamic driving style (larger acceleration values) is increased.

It can also be an actively generated pedal back pressure on the accelerator pedal 4 depending on the currently measured or the calculated accelerations on the accelerator pedal 4 act to give the driver a feedback of the vehicle recognized dynamic driving style.

In a further improved embodiment of the invention, when abruptly resetting the accelerator pedal 4 maintained at the O position of the current gear or downshifted at low engine speeds, a gear to the motor vehicle 1 to achieve a stronger engine braking force in overrun mode. In this case, the automatic transmission should not switch to a possibly higher gear and thus the engine braking force can be reduced.

In addition, in a further improved embodiment, the overrun operation can already be detected when the accelerator pedal 4 as far as the O position is closed, that of the internal combustion engine 2 already via the engine control unit 21 on idle gas (closed throttle) has switched, in which case there is still a residual path on the accelerator pedal 4 in the direction of the O position. On further removal, so reset the accelerator pedal 4 the automatic transmission switches to the O position 3 via the automatic transmission control unit 31 down a gear while doing so via the engine control unit 21 given so much gas that after the downshift the overrun deceleration corresponds to the before the shift and this residual gas at continuing O position on the accelerator pedal 4 is reduced to the idle throttle position (stronger deceleration).

In the special case of downhill skiing, for example, by the lowest throttle position of the engine control unit 21 on the combustion engine 2 (Idling gas) in conjunction with the sensor for accelerations 62 or the travel speed sensor 62 measured increasing speed (positive acceleration) can be moved according to the previous paragraph to the overrun operation with further delay. It is downshifted so often until the internal combustion engine 1 is still operated below the maximum speed. In addition, from the central control unit 5 still be provided an operative connection to the vehicle brakes, however, in the embodiment according to 1 are not shown. This could additionally be used for downhill driving the friction brakes for vehicle deceleration.

Accordingly, at a maximum acceleration of the motor vehicle (setting full power or near full power on the accelerator pedal 4 ) Down in the gear, in which the speed of the engine 2 is less than the maximum speed and when reaching the maximum speed of the automatic transmission 3 one gear higher, with the over the engine control unit 21 on the combustion engine 2 fitting full throttle position (fully open throttle) is maintained. This functionality is similar to the "kick-down control" in known automatic transmission vehicles. Only in this particular case occur Zugerkraftsprünge during the switching process.

It should be noted that for special operating conditions on the motor vehicle, in particular the internal combustion engine 2 , It may be useful not to radically minimize the engine speed to the extent described above, but for example to drive to warm up with cold engine or detected undervoltage in the electrical system with slightly or more increased minimum speed. It should also be noted that the terms "full throttle" and "throttle position" refer to conventional gasoline engines. The control is nevertheless also suitable for diesel engines, whereby the throttle position is replaced by the injection quantity of the injection pump.

LIST OF REFERENCE NUMBERS

1

motor vehicle

11

wheel

2

internal combustion engine

21

Engine control unit

22

powertrain

3

automatic transmission

31

Automatic transmission control means

32

drive shaft

4

accelerator

5

central control unit

6

sensor

61

Sensor for driving speed

62

Sensor for acceleration

63

Engine speed sensor

Claims (10)

Method for operating a motor vehicle with an internal combustion engine and automatic transmission, wherein the internal combustion engine is controlled between idle gas and full throttle and has a minimum speed and a maximum speed, the automatic transmission has different ratios for propulsion of the motor vehicle, which are controllable between a shortest and a longest gear, and a Accelerator pedal is provided for driving the internal combustion engine and the automatic transmission, which is adjustable between a zero position and a maximum position, characterized in that the momentarily requested on the engine power is detected and the automatic transmission switches to a longer gear, when at a resulting engine speed greater Minimum speed, the power detected with a correspondingly increased gas position kleinergleich full throttle is reached, with the upshift without changing the position of the accelerator pedal, the increased throttle position is set for the internal combustion engine. A method according to claim 1, characterized in that downshift is when the internal combustion engine is operated at full throttle and more power is requested by further depression of the accelerator pedal, wherein when downshifting without changing the position of the accelerator pedal, a reduced throttle position for the internal combustion engine is set. A method according to claim 1 or 2, characterized in that with the adjustment of the accelerator pedal, the power of the internal combustion engine is controlled, wherein the lower power range is spread over the pedal travel. A method according to claim 3, characterized in that the assignment of the selected by the pedal position power to the pedal position is dynamically adjusted, wherein the range is spread around the currently selected on the accelerator pedal power. Method according to one of the preceding claims, characterized in that active pedal depression is actively generated on the accelerator pedal in response to the currently measured or the calculated acceleration. Method according to one of the preceding claims, characterized in that maintained at abrupt resetting of the accelerator pedal to the zero position of the current gear or downshifting a gear at low engine speeds. Method according to one of the preceding claims, characterized in that in dynamic driving with a lot of accelerator pedal movement is only switched to a higher gear, when in this the currently requested power multiplied by a dynamic factor can be achieved, the dynamic factor between 1.05 and 2, 0, in particular 1.1 to 1.5. A method according to claim 7, characterized in that the applicable dynamic factor is adjusted as a function of the determined over a predetermined period of time accelerations. Arrangement for operating a motor vehicle ( 1 ) with internal combustion engine ( 2 ) and automatic transmission ( 3 ), wherein the internal combustion engine ( 2 ) between idling gas and full throttle via an engine control unit ( 21 ) is controllable and has a minimum speed and a maximum speed, the automatic transmission ( 3 ) Various translations between a shortest and a longest gear for propulsion of the motor vehicle ( 1 ), whereby the automatic transmission ( 3 ) via an automatic transmission control unit ( 31 ) is controllable, and an accelerator pedal ( 4 ) for driving the internal combustion engine ( 2 ) and the automatic transmission ( 3 ) is provided, which is adjustable between a zero position and a maximum position, characterized in that a central control unit ( 5 ) is provided, on which the gas pedal ( 4 ), the engine control unit and the automatic transmission control unit ( 31 ) are connected, wherein in the central control unit ( 5 ) the maximum achievable engine power depending on the speed as well as the gear ratios are stored. Arrangement according to claim 9, characterized in that in the motor vehicle ( 1 ) Travel speed sensors ( 61 ), Acceleration ( 62 ) and engine speed ( 63 ) with active connections to the central control unit ( 5 ) are provided.

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