Speed control system for a motor vehicle

ES 2 290 902 T3

DESCRIPTION

Speed ​​regulation system for a motor vehicle.

The invention relates to a speed regulation system for a motor vehicle according to the preamble of claim 1.

At present, different speed regulation systems are known in motor vehicles that are activated by actuation of a control element. Automatic cruise control systems can be configured, for example, as cruise control systems or as so-called "adaptive cruise control systems".

From document DE 43 38 098 C2, for example, a control lever for a speed control device in a motor vehicle is known, which is mounted, analogously to a conventional indicator, in the region of the steering wheel. For the activation of different functions that include, among others, the setting of a nominal speed, the recovery of an archived nominal speed and the disconnection of the speed regulation system, the control lever can be moved by manipulation of the same in directions perpendicular to each other.

From document DE 199 61 720 C2 is known a method for regulating the speed of a motor vehicle with a drive motor and a braking system, the speed regulation being activated by the driver in order to maintain the vehicle's speed at a speed. preset nominal speed.

Document DE 100 64 307 A1 shows a control lever for a speed control system in which a desire for acceleration or deceleration can be specified as a function of the force exerted on the control lever. From document DE 195 37 273 A is known the expedient of varying the preset speed of a system of this kind under a brief actuation or a continuous actuation, while a variation of the acceleration is achieved by means of different positions.

The object of the invention is to indicate an improved speed control system.

This problem is solved according to the invention with a speed control system according to claim 1. Advantageous improvements are the objects of the dependent claims.

The speed regulation system according to the invention for a motor vehicle with means of calculating a driving torque or a braking torque as a function of a preset nominal speed, wherein the nominal speed is predetermined by a simple actuation of a control element. controllable control, characterized in that, in the case of continuous operation of the control element, instead of the nominal speed, the a nominal acceleration from which the driving torque or braking torque is calculated.

The speed regulation system according to the invention offers the advantage that the driver can choose between a nominal speed command or a nominal acceleration command. If the driver wants to increase or decrease the current speed to a new speed value, he operates the control element one or more times to preset the corresponding nominal speed. In the case of a single single drive in the positive direction, for example a nominal speed is preset which is increased or decreased by 1 km / h relative to the current speed. In the case of a repetitive single actuation, a nominal speed is preset which is increased or decreased relative to the current speed according to the number of single actuations multiplied by 1 km / h.

On the other hand, if the driver wants acceleration or deceleration, he can preset a nominal acceleration according to the invention by means of a continuous actuation of the control element. The pre-setting of a nominal acceleration command by the driver also offers the advantage that the vehicle reproducibly experiences the same acceleration or deceleration regardless of the current load resistance. The driver, for example when descending a hill, is not surprised by a higher acceleration than that which would occur in the case of a braking or drive command without acceleration. At the nominal acceleration command, a defined nominal acceleration is directly printed on the vehicle, while at the nominal speed command, the acceleration results indirectly from the deviation between the nominal speed and the actual speed, i.e. the current speed. In the case of the nominal acceleration command, no nominal speed is specified, but instead the driver operates the control element for as long as he wants to accelerate or decelerate the vehicle. The driver can be provided with a proactive “co-floating” with the traffic, being able to control the reaction of the vehicle by the driver in an easy to imagine and immediate way, since the driver is actively and directly integrated into the control system of the vehicle. vehicle.

The control element can be designed, for example, as a control lever arranged on the steering wheel. A simple actuation is the result, for example, of applying a single pressure or tension to the control element for a short time. On the contrary, a continuous actuation is the result, for example, of applying pressure or traction for a predetermined period of time. Depending on the direction of the actuation, a nominal speed is set either increased or decreased relative to the actual speed during single actuation of the control element. Also, depending on the direction of the drive, a nominal positive or negative acceleration is preset during continuous drive. Instead of a control lever, the control element can also be designed, for example, as a rocker button.

ES 2 290 902 T3

Since, after the continuous actuation of the control element has been released, a suitable nominal speed is no longer present as a function of which the calculation of the drive or braking torque can be carried out, it is advantageously specified as the nominal speed when the control element is released. I command the current speed or a speed that deviates from the current speed by a preset value. The deviation from the current speed must diverge only by a negligible amount from the current speed and the direction must be preset in such a way that, for a preceding acceleration of the vehicle, it is greater than the current speed and, for a preceding deceleration speed is less than the current speed. Diversion offers the advantage that acceleration or deceleration is degraded in a comfortable way for the driver with an asymptotic transition to the constant driving situation.

Nominal acceleration can be a fixed value. Advantageously, the nominal acceleration is predetermined as a function of at least one parameter. For example, the nominal acceleration can be preset based on the current vehicle speed or other vehicle operating parameters. The higher the current speed of the vehicle, the smaller the absolute value of the nominal acceleration must be. It would also be conceivable to preset the nominal acceleration depending on, among other factors, the driving style of the driver. The nominal acceleration can be preset from a characteristic line or a characteristic field.

Advantageously, when calculating the drive torque or braking torque, load resistances are taken into account, such as, for example, raising or lowering or the aerodynamics of the vehicle, in order to be able to adjust the nominal speed as precisely as possible.

Advantageously, the control element can be actuated in several control planes, a specific nominal speed of the control plane being set in simple actuation of the control element and a specific nominal acceleration of the control plane being set in continuous actuation.

Control elements with several control planes are already used in the field of automatic speed control. In this case, for example, with actuation of the control element in the foreground, the nominal speed is increased or decreased by 1 km / h. In contrast to this, actuation of the control element in a second control plane increases or decreases the set speed, for example by 5 km / h or 10 km / h. Consequently, in the development according to the invention, it is also possible to preset different nominal accelerations in the different control planes during continuous actuation of the control element.

An example of embodiment of the speed system of the invention according to claim is indicated in the drawing

1.

The only figure shows a speed regulation system 10 for a motor vehicle F with means 1, S, 2 and 3 to calculate a driving torque Ma or a braking torque Mb as a function of a preset nominal speed vs, the speed being prefixed nominal vs by means of a simple actuation eb of an actuated control element BE. During simple actuation eb of control element BE, switch S is in position a. If, for example, the driver operates the BE control element once at a current speed of 80 km / h, a nominal speed vs 81 km / h is preset. In a first unit 1, an acceleration as * is preset as nominal acceleration as to obtain the desired nominal speed vs. From the nominal acceleration as calculated in this case, the driving torque Ma or the braking torque Mb is calculated by means of an acceleration controller 20 already known with means 2 and 3. From the difference in nominal acceleration as and the current acceleration aa, a request torque M is calculated in unit 2, from which a driving and / or braking torque is calculated in unit 3. When calculating the drive torque Ma or the braking torque Mb, the load resistances L of the vehicle are advantageously taken into account F. With the drive torque Ma or the braking torque Mb calculated, the vehicle FZG is driven to obtain a speed current goes that corresponds to the preset nominal speed vs.

In the case of continuous actuation db of the control element BE, instead of the nominal speed vs, a nominal acceleration as is specified according to the invention, from which the actuation torque Ma or the braking torque Mb is calculated. Switch S is in position b during continuous db actuation. The nominal acceleration as is advantageously preset as a function of the current speed va. This is specified by means of a characteristic curve a-KL. The acceleration regulation 20 is carried out in the same way as the acceleration regulation 20 to preset the nominal speed setpoint.

When the control element BE is released so that it is no longer subjected to continuous actuation db, a speed va-k which deviates from the current speed va is advantageously preset as the nominal speed vs a preset value K. When the control element BE can be actuated in several planes, a specific nominal acceleration of the control plane is advantageously specified during continuous actuation db.

A large number of other details may be configured entirely differently from the preceding description without thereby departing from the content of the claims.