Patent Application
20080051960
The FIGURE is a block diagram of an embodiment of the present invention.
The single FIGURE illustrates an electronic control unit 1 which is used, for example, for the implementation of a DSC function and/or a DTC function. In addition to other input signals not shown here, the control device 1 receives the signal of a tire pressure control system 3 and of a DTC key 2 in the form of an electric hardware switch (or key), which is normally arranged in the center console of a vehicle.
The tire pressure control system 3 monitors the tire inflation pressure in the four mounted tires of a motor vehicle, which is not shown here, during the drive. For example, by way of a display, the tire pressure control system 3 indicates when, for example, the inflation pressure in one tire has clearly decreased in comparison to another tire and a loss of tire pressure is, therefore, determined. If the tire pressure control system 3 detects a loss of tire pressure in this or any other manner, the control unit 1 will receive that information.
The DSC function in the control unit 1 is always switched on and prevents a spinning or slipping of the driving wheels during the starting and accelerating operations. Furthermore, by way of the DSC function, unstable driving conditions are detected, such as a swerving of the vehicle's rear end or the lurching of the vehicle by way of the front wheels. In these cases, the DSC function helps to keep the vehicle on course by the reduction of the engine power and/or by braking interventions at individual wheels. The DSC function is always automatically activated after each engine start, but can also be manually deactivated by way of the DTC key 2 and activated again.
When the DTC key 2 is briefly operated once, the DSC function will be manually switched-off such that a switch-over takes place to the DTC function or only this DTC function remains activated. The DTC (Dynamic Traction Control) is a variant of the DSC and is optimized with respect to propulsion for special road conditions, for example, roadways from which snow has not been removed. The DTC function ensures a maximal propulsion, but with a limited driving stability. The DTC function is preferably automatically deactivated at an increased vehicle speed (approximately >70 km/h), or the increased DTC control thresholds are returned to the lower DSC control thresholds for the purpose of providing stability. This can take place abruptly, starting at a certain speed threshold or continuously over the speed.
When a loss of tire pressure is determined according to the invention, this is indicated to the control device 1 by the tire pressure control system 3. When the DSC function is switched off manually—that is, in the case of a switch-over to the DTC function—, the control device 1 then automatically activates the (complete) DSC function again.
A deactivation of a system is, therefore, also a limitation of the system or a switch-over to a different function mode of the system, as in the preceding case.
In addition, for example, the DTC function, as well as the DSC function, can be switched off by a prolonged operation of the DTC key 2. The control device 1 will then also automatically activate at least the DTC function, but preferably also the (complete) DSC function if both functions had previously been switched-off manually.
If one of the functions is then manually deactivated again because it is intentionally desired by the driver, in a further development of the invention, this function continues to be deactivated at least for the current ignition cycle even if a loss of tire pressure was determined.
The forced activation of the DCS and/or the DTC may be indicated to the driver by way of suitable indicating devices in the instrument panel (such as lamps, symbols, text information).
In a supplementary manner, in the event of a loss of tire pressure—in order to avoid an inclined position of the vehicle and, as a result, not unnecessarily impair the longitudinal and lateral stability—the vehicle body can also be raised by way of the air suspension at the concerned impaired wheel.
The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2006 039 379.1 | Aug 2006 | DE | national |
