Patent Application
20050085341
The present invention relates to a detection device for detecting the wish of a driver of a motor vehicle for a change in the overall thrust torque currently provided by the motor vehicle, by analyzing a plurality of significant measuring variables of the vehicles. The present invention also relates to a device, a method and a computer program for realizing this driver wish.
In connection with motor vehicles having internal combustion engines, in particular diesel gasoline engines, it is understood from the related art to shift these vehicles into overrun operation when it is determined, by analyzing an accelerator pedal signal, that the driver of the motor vehicle is not activating the accelerator. Overrun operation, also called unfiring overrun operation, means that no torque-generating injections take place into the internal combustion engine. In overrun operation, the internal combustion engine in conjunction with various ancillary components of the motor vehicle generates a thrust torque that is made up of the negative sum of their friction torques and torque losses, which is translated according to the gear transmission ratio. This results in a slight overall delay for the vehicle response.
The described detection of a non-activation of the accelerator may be interpreted as a driver wish to initiate overrun operation. In the related art, overrun operation is initiated when the corresponding accelerator setting is detected by the components of the motor vehicles that are activated because of the instantaneous driving situation and the instantaneous operating state, i.e., in particular by the internal combustion engine and various ancillary components. While the overall thrust torque that will then result as actual variable is situation-dependent, as mentioned earlier, it is otherwise essentially constant.
However, the overall thrust torque that will automatically come about when overrun operation is initiated may not correspond to a driver-desired overall thrust torque for the entire duration of overrun operation. In other words: During overrun operation, it may happen that the driver desires a change in the acting overall thrust torque from the automatically resulting overall thrust torque.
An object of the exemplary embodiment of the present invention is to provide a detection device for detecting the wish of a driver of a motor vehicle for a specific overall thrust torque that the motor vehicle is to supply during an instantaneous overrun operation, as well as a device, a method and a computer program for realizing this.
This objective is achieved by a detection device for detecting the wish of a driver of a motor vehicle for a specific overall thrust torque to be supplied by the motor vehicle during an instantaneous overrun operation, by analyzing at least two of the following signals: a brake signal, which represents a driver-initiated activation of the brake pedal; an accelerator signal, which represents the instantaneous position of the accelerator; a speed signal which represents the actual speed of the vehicle; a power transmission signal, which represents a power transmission in the power train of the motor vehicle; and/or a status signal, which represents the status of a driving speed controller of the motor vehicle; and for outputting a driver input signal, which represents this desired overall thrust torque.
In an advantageous manner, the detection device provides for detecting the wish of the motor vehicle driver for a specific overall thrust torque that is to be provided by the motor vehicle during an instantaneous overrun operation. That is to say, the subject matter of the exemplary embodiment of the present invention does not primarily relate to the wish of the driver for the initiation of overrun operation, but to a possibly desired change in the overall thrust torque during an existing overrun operation.
Overrun operation within the meaning of the exemplary embodiment of the present invention denotes non-firing overrun operation, i.e., no torque-generating injections into the internal combustion engine of the motor vehicle are taking place.
Four exemplary embodiments are introduced first to realize the exemplary detection devices of the present invention. On the one hand, these exemplary embodiments may be considered alternatives, each of these alternatives by itself representing a functional realization of the detection device. On the other hand, however, these exemplary embodiments, in any combination with each other, may also constitute further exemplary embodiments for realizing the detection device. In this case, at least two of the original exemplary embodiments are to be provided in each case and their individual driver input signals must then be analyzed by an evaluation device, which is to be provided in addition, so as to finally derive therefrom a common driver input signal.
In an advantageous manner, this evaluation consists of an averaging of the individual expressions of the driver wish for a change in the overall thrust torque, these expressions being represented by the individual driver input signals.
However, as an alternative to averaging, the evaluation device may select the least expressed or the most highly expressed driver input.
In addition, the aforementioned objective of the exemplary embodiment of the present invention is achieved by a device for coordinating the thrust torque of an internal combustion engine in a motor vehicle and by a method and a computer program for implementing this coordination in response to the driver input signal provided by the detection device. The advantages of these achievements correspond to the advantages mentioned in connection with the claimed detection device.
The exemplary embodiments of the present invention are discussed in greater detail in the form of the exemplary embodiments with reference to
Using a binary comparator unit 112-1-1, accelerator signal S22 is first analyzed with respect to ascertaining whether or not the accelerator is actually activated by the driver of the motor vehicle. In the exemplary embodiment illustrated in
As already mentioned previously, the first exemplary embodiment of detection device 112-1 according to the present invention also analyzes binary brake signal S21 by using it as binary control signal for a binary switching device 112-1-5. This binary switching device 112-1-5 generates a binary switching signal in the form of a logical zero at its output if brake signal S21 indicates no activation of the brake, and in the form of a logical one in the opposite case. As soon as an activation of the brake in the form of a logical one is detected at the output of binary switching device 112-1-5, this determination is used to start a digital integrator 112-1-6, which is provided downstream from binary switching device 112-1-5. This integrator 112-1-6 thereupon starts a counting operation, so that the particular instantaneous reading of this count represents the individual time duration during which the brake pedal is activated. In the first exemplary embodiment of the detection device according to the present invention as shown in
The decimal numerical value output by the integrator, which, as mentioned, represents the time duration during which the driver depresses the accelerator, is limited to a decimal value between zero and one by a limiting device 112-1-7 connected downstream from integrator 112-1-6. In this context, a decimal value of zero is interpreted as a driver wish for an overall thrust torque that is as low as possible and a decimal value of one as a driver wish for an overall thrust torque of the motor vehicle that is as high as possible. Due to the state change just described, from a logical zero to a logical one at the output of AND-gate 112-1-2, switching device 112-1-8 is switched over in such a way that it no longer receives the fixedly specified decimal value of zero at its input, but instead the decimal numerical value between zero and one, which is output by limiting device 112-1-7, and outputs it at its output in unchanged form, as individual driver input signal SF-1. The magnitude of this numerical value corresponds to the magnitude of the overall thrust torque currently desired by the driver.
Furthermore, the second exemplary embodiment of detection device 112-2 includes a delay element 112-2-5 to delay accelerator signal S22. Delayed accelerator signal S22 is relayed to a memory device 112-2-6. In response to an enable signal, a respective instantaneous value of delayed accelerator signal S22 is stored in memory device 112-2-6. The enable signal is generated by a decision stage 112-2-4 in those cases where a state change detector 112-2-3 generates a logical one at its output, i.e., when it has detected a change of state from a logical zero to a logical one at the output of logical AND-gate 112-2-2. The value stored in memory device 112-2-6 in response to the enable signal is a measure of the dynamic response in the change of the accelerator position.
Connected downstream from memory device 112-2-6 is a characteristic curve evaluation device 112-2-7. Using a characteristic curve, the characteristic curve evaluation device interprets the value of delayed accelerator signal S22, which was stored and output by memory device 112-2-6, as the current driver wish for a specific thrust torque. If a logical one is present at the output of logical AND gate 112-2-2 and switching device 112-2-8 is therefore switched to the output of characteristic curve evaluation device 112-2-7, a numerical value, which is provided by characteristic curve evaluation device 112-2-7, is output via switching device 112-2-8 in the form of an individual driver input signal SF-2. This numerical value, which is usually greater than zero, then represents the specific overall thrust torque currently desired by the driver.
At the output of switching device 112-3-8, the third exemplary embodiment then again generates an individual driver input signal SF-3, which represents the instantaneous driver wish for a specific overall thrust torque during an instantaneous overrun operation. The driver wish for an overall thrust torque that goes beyond the minimally possible overall thrust torque is registered as long as the motor vehicle is still accelerating, notwithstanding the fact that a power transmission is present in the power train of the vehicle and the accelerator is not activated.
Finally, a fourth exemplary embodiment of detection device 112-4 according to the present invention is shown in
The four different exemplary embodiments of the detection device according to the present invention which have so far been described with reference to
In contrast, however, the four exemplary embodiments 112-1- . . . -4 may also be operated in parallel, in any combination with one another, each possible combination then in turn representing a another exemplary embodiment of the detection device by itself.
To adjust the driver-desired overall thrust torque, a control unit 130 of device 100 is given information about the driver-desired overall thrust torque. In those cases where detection device 110 has only one of the four illustrated exemplary embodiments 112-1 . . . -4, this notification is implemented in the form of a direct output of the individual driver input signals SF-1 . . . -4, which are then generated by detection device 110, directly to control device 130. In contrast, control unit 130 receives the driver-desired overall thrust torque in the form of common driver input signal SF if detection device 110 encompasses a combination of said exemplary embodiments 112-1 . . . -4 and evaluation device 114.
In addition to the driver-desired setpoint overall thrust torque, control unit 130 also receives the current instantaneous overall thrust torque of the vehicle in the form of a multitude of individual instantaneous thrust torques of individual components K-1 . . . -N of the vehicle. The individual instantaneous thrust torques are recorded and provided by measuring devices 120-1 . . . -N assigned to components K-1 . . . -N. Apart from the internal combustion engine of the motor vehicle, ancillary components are also among components K-1 . . . -4. This supply of both instantaneous thrust torques and of the desired overall thrust torque is symbolized in
In a following method step S2, control unit 130 then implements a comparison between the driver-desired setpoint overall thrust torque and the instantaneous overall thrust torque it has ascertained. In the event that control unit 130 detects a deviation of the setpoint variable from the instantaneous variable during this comparison, it is configured to output suitable control signals C-1 . . . -N to the particular individual components K-1 . . . -N according to method step S3. With the aid of these control signals, control unit 130 then controls individual components K-1 . . . -N in such a way that the driver-desired overall setpoint thrust torque comes about in the motor vehicle. The control of the components takes the thrust torques each is currently providing into account and the maximum thrust torque that each is able to provide. For instance, the control may consist in individual components K-1 . . . -N being turned on or off or in an individual adjustment of the individual components. In addition to control signals C-1 . . . -N, control unit 130 may also output, as separate variable, the instantaneous overall thrust torque that it calculated in order to implement the comparison. Method step SE denotes the conclusion of the method.
The method is advantageously realized in the form of a computer program for device 100 for coordination of the thrust torque.
| Number | Date | Country | Kind |
|---|---|---|---|
| 103 48 249.0 | Oct 2003 | DE | national |
