DE10161900A1 - Method for controlling accelerator pedal response during deceleration for motor vehicles, especially those with automatic CVT transmissions, using control module which changes width of operating regions of pedal - Google Patents

Abstract

A method for electric accelerator pedal deceleration control, where the pedal has different operating regions for control of the engine and for slowing the vehicle down. Accordingly the pedal (4) is electrically connected to a control module that changes the width of the operating regions (28, 29) of the pedal by changing the overlap borders (30, 32) according to driving conditions.

Description

Field of the Invention

The present invention relates to a method for drive and deceleration control for a motor vehicle via an accelerator pedal according to the preamble of claim 1.

The drive device of the motor vehicle consists of an internal combustion engine as well an automatic transmission for power transmission to the drive wheels.

State of the art

In motor vehicles with automatic transmissions, the gear ratio is from a transmission control unit according to a specified operating program and depending on the Driving performance request of the driver set, which with the accelerator pedal by an electri accelerator pedal sensor via an engine control unit to the power controller of the combustion voltage engine, for example a throttle valve, acts on its torque output. The engine control unit communicates with the transmission control unit, while in driving mode stronger accelerator pedal actuation by the driver, the gear ratio in the sense of higher Acceleration values is shortened, while at lower driving performance requirements an accelerator pedal withdrawal with a view to low fuel consumption as well for acoustic reasons, the gear ratio in the sense of low engine speeds is lengthened. When the accelerator pedal is withdrawn accordingly, the internal combustion engine arrives finally in the so-called thrust area, in which the accelerator pedal depression decreases An engine braking torque increasingly occurs, which finally in the basic position of the Lei power controller maximum values reached. With the available engine braking torque, this can be done Vehicle corresponding to the Automa transmission ratio, which is usually long tik gearbox are only moderately delayed. An increased vehicle deceleration is with today series vehicles only by manual downshifting of the automatic transmission or achieved by applying the brakes.

Improving driving comfort is by expanding the function of the Fahrpe dals possible by a delay effect in the power controller effective range of the accelerator pedal area upstream for increased vehicle deceleration. In this delay the driver can use the accelerator pedal to control the engine braking effect via a ver Increase the reduction in gear ratio for increased vehicle deceleration. here by the active actuation of the vehicle brake is reduced, so that advantages in terms Ease of use and brake wear can be achieved. As a result of the delay  effective range of time longer engine operation in the thrust area are still Ver benefits from the fuel cut-off that is effective in the overrun area.

Continuously variable automatic transmissions, so-called CVT transmissions, are particularly good for one realized an accelerator pedal deceleration effective area, increased vehicle deceleration as a result the resulting improvement in driving comfort. The deceleration effective range of the Accelerator pedals can be used additionally or exclusively for special vehicle versions activation of the vehicle brakes can be used.

DE 43 05 737 A1 and DE 199 22 338 A1 describe devices for motor vehicles where the accelerator pedal has an additional deceleration effective range having. This deceleration effective range is in accordance with the actuation logic of the Accelerator pedal starting from the accelerator pedal basic position for engine idling at one Accelerator pedal actuated first to then operate the usual power controller range of the internal combustion engine between maximum engine braking torque at power level basic position and maximum drive torque at full throttle.

The effective deceleration range of these known devices is determined by the accelerator pedal at ei nem start-up or acceleration process without mileage effect until finally, at the end of its effective range, the actuation of the combustion power controller used with a corresponding increase in torque. With this increasing Accelerator pedal actuation from the accelerator pedal basic position may affect the deceleration effective range must not be too wide so that the driver is not "Lost motion" without unsettling the torque effect of the internal combustion engine.

On the other hand, with a reduction in driving performance up to an increased vehicle deceleration tion is close with these known devices with a corresponding accelerator pedal from a position close to full throttle, the engine torque is first reduced and then closed Lich into an engine braking torque with correspondingly long gear ratio transferred vehicle deceleration, then from reaching the deceleration effect Reichs with further accelerator pedal withdrawal at maximum engine braking torque increasing shortening of the gear ratio to increase the engine braking effect for the vehicle deceleration begins. For sensitive control of vehicle deceleration via the However, gear ratio here is a correspondingly large effective range of the deceleration effective range of action is necessary, but this contradicts the requirement mentioned above after a small effective range of the deceleration effective range for a start-up or loading acceleration process stands.  

From the published patent application DE 197 38 183 A1, the use of a path is still unavailable dependent pressure sensor instead of the usual, pedestrian accelerator pedal known.

Description of the invention

It is an object of the present invention, compared to the prior art, the Fahrpe dalfunktion to improve so that the deceleration effective range on the one hand when starting and Acceleration processes for the driver without adverse accelerator pedal effects, others on the other hand, in the event of deceleration, the accelerator pedal to be carried out by the driver Delay control available according to the requirements in a reasonable effective range is available. This aim is achieved according to the invention by the characteristic features of the Claim 1 reached.

In the solution of the task according to the invention, the position of the accelerator pedal area Transitional boundary between the effective delay area and the subsequent Lei Stungssteller effective range adapted to the constantly changing requirements in driving. Here, depending on relevant influencing factors, such as Fahrge Speed, downhill or uphill ride, vehicle loading, smooth road condition or individual driver requirements, the location of the transition limit via a control module positioned according to the requirements.

When starting, the effective range transition limit can, for example, be up to Accelerator pedal position are shifted so that with the start of accelerator pedal actuation the power controller effective range is activated and therefore not a nuisance for the driver Accelerator pedal "lost motion" due to the effective deceleration range deactivated here occurs.

As the driving speed increases, the speed increases as required Delay request the effective range transition limit after a certain radio tion in the accelerator pedal effective range, so that the deceleration effective range associated effective range assumes. The effective range transition limit at vehicle maximums Speed can then be half the accelerator pedal travel, for example.

In the event of a deceleration from an assumed starting position with the vehicle top speed causes an increasing accelerator pedal withdrawal in the power controller effective range first a drive torque reduction with subsequent transition to with an increasing engine braking torque up to the basic position of the power controller maximum engine braking torque, but according to the invention, for example, while still available  rem, half accelerator pedal travel for the deceleration effective range. Corresponding to that with waste lender driving speed decreasing engine speed, the driver can now in the relative wide deceleration effective range of the accelerator pedal, the gear ratio is sensitive with egg increasingly reduce the accelerator pedal retraction. On the one hand, this results in a higher engine braking torque due to the corresponding engine speed increase and others by reducing the gear ratio for this increased engine braking torque additional reinforcing effect to a much higher engine braking effect on the Driving wheels with a correspondingly increased vehicle deceleration.

If the desired maximum utilization of the engine braking torque is used for the vehicle deceleration For example, the gear ratio would have to continuously increase with the speed Decrease in speed in the sense of maximum engine speeds with the highest engine braking torque be adjusted until the lowest possible gear ratio is reached.

With decreasing driving speed, the position of the effective range transition limit For example, continuously withdrawn in the accelerator pedal effective area of the accelerator pedal a larger power controller for possible subsequent acceleration processes Effective range available.

All influencing variables relevant for vehicle deceleration in addition to the driving speed such as driving on slopes or inclines, changing vehicle loads or changed road conditions, such as slippery conditions, can be controlled via the On control module flow to the variable effective range transition limit in the accelerator effective range.

In addition to the position of the effective range transition limit regulated by the control module, over an adjusting element in the cockpit area of the vehicle also gives the driver a basic setting be granted for the accelerator pedal deceleration effective range, which for example step is possible via a potentiometer between "ineffective" and "fully effective". Here it is advantageous to influence the position of the effective range transition limit via the potentiometer influence. While with a potentiometer setting "0" (ineffective) the effective range Transitional limit in all driving situations on the accelerator pedal basic position remains and the deceleration effective range is therefore generally ineffective, this could over limit with a potentiometer setting "100" (fully effective) as in the example of Functional description above at maximum vehicle speed at 50% Accelerator pedal actuation. For the potentiometer setting "50" (semi-effective) would be included assumed maximum vehicle speed then the effective range transition limit with 25% accelerator pedal actuation.  

Instead of the potentiometer, a tap changer can also be used as the control element come, whereby in addition to a simple on-off switching also a multi-stage detent with intermediate positions is conceivable.

Usual accelerator pedals have an effective actuation path with corresponding travel-dependent accelerator pedal effective areas, with the actuation force being constant almost independent of travel is. In the case of a force sensor that alternatively effectively replaces the accelerator pedal, the solution according to the invention can also be used. As a result of the sy The individual effective ranges are then stem signals dependent on the actuating force force-dependent, so that the positioning of the control module to be performed by the control module rich dividing transition boundaries must then be assigned to force.

Brief description of the drawings

Further details of the invention will become apparent from the description below of exemplary embodiments shown schematically in the drawings. Show it:

Fig. 1 is a schematic representation of the scope of a motor vehicle relevant to the invention

Fig. 2 shows an effective area distribution of the accelerator pedal according to the invention for maximum vehicle speed

Fig. 3 is an active area division of the accelerator pedal according to the invention for half maximum vehicle speed

Fig. 4 shows an effective area distribution of the accelerator pedal according to the invention with additional brake control

Fig. 5 is a diagram with various accelerator pedal characteristics

Description of preferred embodiments

In a preferred exemplary embodiment of the invention, a motor vehicle is driven by an internal combustion engine in which the power is transmitted to the drive wheels via a continuously variable automatic transmission, a so-called CVT transmission. For this purpose, Fig. 1 shows a combustion engine 1, is flanged to a CVT gearbox 2. The internal combustion engine 1 and the CVT transmission 2 are controlled in their interaction by a programmed module 3 . Via an accelerator pedal 4 with electrical signal transmission to module 3 , the driver specifies a driving performance request, which is made by module 3 in a corresponding position of a power controller 5 of the internal combustion engine 1 , which is shown in FIG. 1 as a throttle valve, as well as in an associated setting of the Translation of the CVT transmission 2 is implemented.

The power provided by the internal combustion engine 1 is converted by the CVT transmission 2 in terms of speed and torque and transmitted by a drive shaft 6 and a Antriebsach se 7 to the drive wheels 8 and 9 .

The brake system of the motor vehicle has a brake pedal 12 , the wheel brakes 10 and 11 and further wheel brakes of other axes not shown in FIG. 1, as well as a brake force control device 13 connected to the module 3 via a connecting line 14 . The driver can manually influence a processor in module 3 via a switching element 15 in order to influence the accelerator pedal deceleration control according to his personal wishes. From a certain deceleration value of the motor vehicle, the effect of the accelerator pedal deceleration control is displayed by module 3 by means of a brake light 16 independently of the brake system.

Fig. 2 shows on an enlarged scale the accelerator pedal 4 , which is attached to the floor panel 22 of the motor vehicle via a bearing pin 20 and a bearing block 21 . A potentiometer 23 for detecting the accelerator pedal position is arranged on the bearing block 21 . The three connections 24 are used for signal transmission to module 3 . The bearing block 21 has a base stop 25 and an end stop 26 for the driving pedal 4 , between which the driving pedal effective area 27 of the accelerator pedal 4 is located. The accelerator pedal effective area 27 is divided into the active deceleration effective area 28 and the power controller effective area 29 , which are separated from the transition limit 30 .

The position of the transition limit 30 is variably positioned according to the present driving parameters, such as the vehicle speed, or the driver's setting of the switching element 15 by the appropriately programmed module 3 in the accelerator pedal effective area 27 of the accelerator pedal 4 .

For this purpose, the processor of module 3 receives corresponding information about the driving state of the vehicle. In the embodiment shown in FIG. 1, the module 3 is connected to the accelerator pedal 4 in order to obtain a predetermined driving performance information via its potentiometer 23 . Furthermore, the switching element 15 to be set by the driver optionally provides information about the desired degree of effectiveness of the accelerator pedal deceleration control. Other connections connect the module 3 with the internal combustion engine 1 and the CVT transmission 2 , so that power and transmission settings can be made. Furthermore, information about torques and speeds can be called up via these connections, from which mileage values such as speed, acceleration or deceleration can be derived. Acceleration values can also be delivered directly to module 3 from an acceleration sensor. Further information can be exchanged via the connecting line 14 to the brake force control device 13 . It is understood that in the case of simpler designs, one or the other input line from module 3 can be omitted, but additional information about the current or intended driving situation can also be included.

In any case, the processor of module 3 takes over this input information and moves the position of at least one transition limit, such as transition limit 30 in FIG. 2, in order to change the effective width of the delay effective area 28 and to adapt it to the current conditions. This can be done in such a way that the processor of module 3 combines the information, possibly taking into account a rating (where, for example, the manual setting via the switching element 15 can have priority), for example by an algorithm.

For the maximum vehicle speed on which FIG. 2 is based, the module 3 positions the position of the transition limit 30 between the power controller effective area 29 and the decelerated effective area 28, for example when the accelerator pedal 4 is pressed halfway.

A desired by the driver vehicle deceleration performs an increasing Rücknah me of the accelerator pedal 4 in the power controller operative region 29 first to a Drehmomentredu cation and finally in the thrust range of the engine 1 to an increasing engine braking torque, the limit on reaching a position of the accelerator pedal 4 at the junction 30 through the base stop of the power controller 5 of the internal combustion engine 1 assumes a maximum value.

While in conventional motor vehicles without accelerator pedal deceleration control, a further increase in deceleration is now only possible by manually shifting down the automatic transmission or by actuating the vehicle brake system, the deceleration effective area 28 offers a comfortable increase in deceleration by further reducing the accelerator pedal 4 by reducing the ratio of the CVT transmission 2nd

FIG. 3 shows, starting from FIG. 2, for example, a position of the accelerator pedal 4 at half the maximum speed with an existing effective area distribution, in which the deceleration effective area 28 now only covers 25% of the accelerator pedal effective area 27 .

Fig. 4 shows a second embodiment of the accelerator pedal deceleration control according to the invention with additional activation of the vehicle brake by the accelerator pedal 4th

As in FIG. 2, the position of the accelerator pedal 4 is also here for a relatively high engine torque in the power controller effective area 29 near the end stop 26 . The neighboring deceleration active region 28 with the transition limit 30 is preceded, in addition to FIG. 2, by a wheel brake active region 31 with an associated transition limit 32 for activating the vehicle brake system. Through the controlling module 3 , the position of the transition limit 32 between the deceleration effective area 28 and the wheel brake effective area 31 can be variably adjusted according to the invention, as can the driver via the appropriately trained control element 15 on the wheel brake active area 31 can have an influence.

FIG. 5 shows a diagram in which various design characteristics of the fiction, modern accelerator pedal deceleration control depending on the driving speed of the vehicle to the effective range 27 show the percentage of the delay active region 28 on the accelerator pedal of the accelerator pedal 4.

In a first exemplary configuration with a linear characteristic curve A for a vehicle operation in the plane, the deceleration effective area 28 occupies 50% of the accelerator pedal effective area 27 at _maximum vehicle speed V _max , which corresponds to the accelerator pedal effective area distribution in FIG. 2. Due to the linear basic characteristic curve A, the proportion of the deceleration effective region 28 at half maximum speed is 25% of the accelerator pedal active region 27 according to FIG. 3, in order then to be ineffective when the vehicle is stationary.

When driving down a slope, a larger characteristic curve slope, for example in accordance with characteristic curve B, can be specified via an inclination sensor in module 3 in order to take into account the increased deceleration requirement here with an expanded deceleration range 28 . When driving up a slope and correspondingly less deceleration is required, a more sensitive power control of the internal combustion engine 1 can be achieved with a relatively flat characteristic curve C through the power controller area 29 which is thereby expanded.

The selection of a fundamentally degressive characteristic curve characteristic can be advantageous compared to the linear characteristic curves A to C, since with an accelerator pedal deceleration control at low driving speeds, relatively high deceleration effects can be achieved due to the short transmission ratios possible here. The relatively steep increase in the degressive characteristic curve D at low speeds advantageously enables the driver to perform a sensitive deceleration control with the accelerator pedal 4 in comparison with a configuration according to the characteristic curve A.

If the road surface is slippery, you can use the accelerator pedal deceleration control a change in the characteristic curve can also be carried out.

Claims (9)

1.Procedure for accelerator pedal deceleration control for a motor vehicle, with an internal combustion engine as the drive source, with an automatic transmission for power transmission to the drive wheels, with an electric accelerator pedal with various effective ranges for controlling the vehicle drive and the vehicle deceleration, and with an in electrical connection to Accelerator pedal module for drive and deceleration control, characterized in that the effective widths are varied by the module ( 3 ), the individual active areas ( 28 , 29 , 31 ) of the accelerator pedal ( 4 ) by changing the position of the transition limits separating them ( 30 , 32 ) are. 2. The method for an accelerator pedal deceleration control according to claim 1, characterized in that the positions of the transition limits ( 30 , 32 ) of the effective ranges ( 28 , 29 , 31 ) of the accelerator pedal ( 4 ) as a function of variables relevant to driving operation of the module ( 3 ) be managed. 3. The method for an accelerator pedal deceleration control according to one or more of the preceding claims, characterized in that the effective widths of the deceleration effect area ( 28 ) and the wheel brake effective area ( 31 ) increase starting from ineffective at vehicle standstill with increasing vehicle speed. 4. Procedure for accelerator pedal deceleration control according to one or more of the above forthcoming claims, characterized in that the delay control using the engine braking torque by varying the transmission ratio is done. 5. Procedure for accelerator pedal deceleration control according to one or more of the above forthcoming claims, characterized in that the delay control on the braking system of the vehicle acts. 6. A method for accelerator pedal deceleration control according to one or more of the preceding claims, characterized in that at a position of the Fahrpe dals ( 4 ) in the effective deceleration area ( 28 ) or in the wheel braking area ( 31 ) the maximum vehicle deceleration and / or the maximum engine speed are limited. 7. A method for accelerator pedal deceleration control according to one or more of the preceding claims, characterized in that the effective areas ( 28 , 29 , 31 ) of the accelerator pedal ( 4 ) can be influenced manually by the driver through a switching element ( 15 ). 8. A method for an accelerator pedal deceleration control according to one or more of the preceding claims, characterized in that the accelerator pedal ( 4 ) is designed as a driving force sensor and the individual effective areas ( 28 , 29 , 31 ) with their associated transition limits ( 30 , 32 ) can be set independently of the path according to the amount of actuating force of the accelerator pedal ( 4 ). 9. The method for an accelerator pedal deceleration control according to one or more of the preceding claims, characterized in that from a certain driving test delay by the module ( 3 ) the brake light ( 16 ) is activated.