Method and device for detecting the actuation of an accelerator pedal of a motor vehicle

Abstract

Method for detecting the position (S) of an accelerator pedal (2) of a motor vehicle (3), in which an accelerator pedal raw signal (7), which describes the position (S) of the accelerator pedal (2) as a function of time (t), is detected and the accelerator pedal raw signal (7) is smoothed, characterized in that half-waves (8) of the accelerator pedal raw signal (7) are determined, on the basis of the determined half-waves (8) a state of instability during an actuation of the accelerator pedal (2) is detected and the accelerator pedal raw signal (7) is smoothed if the state of instability is detected.

Description

[0001] The present invention relates to a method for detecting the actuation of an accelerator pedal in a motor vehicle, in which a raw accelerator pedal signal, describing the accelerator pedal travel as a function of time, is detected and the raw accelerator pedal signal is smoothed. Furthermore, the present invention relates to a device for detecting the actuation of an accelerator pedal travel in a motor vehicle.

[0002] The focus here is on detecting the activation of a motor vehicle's accelerator pedal. Such an accelerator pedal, also known as a gas pedal, is used to control the engine power of the vehicle's drive motor. Depending on the position or angle of the accelerator pedal, the drive motor, or rather the required torque from the drive motor, is adjusted. For this purpose, a raw accelerator pedal signal, which describes the position of the accelerator pedal, can be determined using a suitable sensor. With increasingly sophisticated, optimized, and sophisticated control systems, the raw accelerator pedal signal, as well as its temporal progression, is used to determine how the drive motor should behave according to the driver's wishes.

[0003] Modern vehicles exhibit significant differences in their driving modes with regard to accelerator pedal response. Particularly for inexperienced or untrained drivers, or those who have driven the vehicle for the first time or only a few times, the resulting reaction of the engine to the accelerator pedal input can be difficult to predict. Even minor changes in the accelerator pedal signal can result in a noticeable change in the vehicle's position, which the driver may not have intended. This can, for example, lead to pronounced load changes. With frequent load changes, the vehicle's response may be perceived as disruptive.

[0004] In addition, future emissions testing will be conducted on public roads using special emissions control technology. The driver's driving style is not restricted during these tests. Frequent and irregular use of the accelerator pedal can lead to increased emissions, which in the worst case can result in a vehicle failing the emissions test. Furthermore, such a driving style does not result in meaningful acceleration of the vehicle and should therefore be discouraged.

[0005] Methods for smoothing the raw accelerator pedal signal are known in the prior art. DE 197 56 568 A1 describes a device for detecting the opening degree of an accelerator device, comprising an accelerator pedal position sensor for detecting the position of the accelerator pedal and a calculation section for calculating the opening degree of the accelerator device based on an output signal from the accelerator pedal position sensor. The output signal of the accelerator pedal position sensor can be smoothed using smoothing coefficients.

[0006] Furthermore, DE 10 2011 088 289 A1 describes a method for smoothing the accelerator pedal signal of an active accelerator pedal, in which a sensor captures a raw accelerator pedal signal. Additionally, an actuator generates haptic feedback at the accelerator pedal. The raw accelerator pedal signal is temporarily stored when no haptic feedback is generated, and a smoothed accelerator pedal signal based on the stored raw signal is determined when haptic feedback is generated.

[0007] The object of the present invention is to provide a solution for how the position of an accelerator pedal of a motor vehicle can be detected more reliably depending on the actuation of the accelerator pedal.

[0008] This problem is solved according to the invention by a method and by a device having the features according to the respective independent claims. Advantageous embodiments of the present invention are the subject of the dependent claims.

[0009] A method according to the invention serves to detect the position of an accelerator pedal of a motor vehicle, in which a raw accelerator pedal signal, which describes the position of the accelerator pedal as a function of time, is detected and the raw accelerator pedal signal is smoothed. Furthermore, half-waves of the raw accelerator pedal signal are determined; based on the determined half-waves, a state of instability during an actuation of the accelerator pedal is detected, and the raw accelerator pedal signal is smoothed if the state of instability is detected.

[0010] The process involves determining the accelerator pedal signal. This signal describes the position of the accelerator pedal, or its travel, over time. The signal can be generated using a suitable sensor that measures the pedal's position or angle. Depending on the accelerator pedal position, a vehicle's drive motor can be controlled. Specifically, the drive power output of the drive motor can be determined based on the accelerator pedal position.

[0011] According to a key aspect of the present invention, the system detects any unsteadiness when the accelerator pedal is pressed. The accelerator pedal is operated by the driver's foot. If the driver is inexperienced or untrained, they may not be able to accurately judge the drive power in relation to the pedal position. This situation can also occur if the driver is operating the vehicle for the first time or has only driven it a few times. This can lead to increased emissions. If the accelerator pedal signal is generally smoothed, this can result in the accelerator pedal being deactivated less immediately. In particular, delays in the control of the drive motor can occur. This can lead to a reduction in comfort and a loss of performance.

[0012] The present invention is based on the finding that the accelerator pedal signal is only smoothed if a predetermined state of instability is detected when the accelerator pedal is actuated. To detect this instability, the half-waves of the accelerator pedal signal are determined. These half-waves can, in particular, describe oscillations of the accelerator pedal signal. The half-waves can also describe maxima and / or minima of the accelerator pedal travel. Based on these half-waves, an uneven movement of the accelerator pedal can be detected. In this case, the accelerator pedal signal can then be smoothed.

[0013] The state of instability is preferably detected if a number of half-waves exceed a threshold within a predetermined time period. To determine the state of instability, the half-waves in the accelerator pedal signal can be counted. If the half-waves exceed a predetermined threshold within a predetermined or applicable time period, the state of instability can be assumed. This predetermined time period can be relatively short and measurable. Therefore, if several half-waves or oscillations are present in the accelerator pedal signal within this predetermined time period, the state of instability can be reliably detected.

[0014] According to another embodiment, the state of instability can be detected based on the time interval between the half-waves and / or on the amplitude of the half-waves and / or on the distance of the amplitudes of the half-waves from a mean value. Thus, it is possible to determine how frequently and at what time intervals the half-waves occur. It is also possible to consider the amplitudes of these half-waves. Furthermore, it is possible to determine the distance of the amplitudes from a mean value or center point. Therefore, it can be determined that the fluctuations in pedal position always occur around a similar or identical value, so that it can generally be assumed that the driver actually intended to maintain a pedal position at or around the center point, and that the oscillations or half-waves represent an unwanted instability.This allows the determination of the state of restlessness in a simple and reliable way.

[0015] Preferably, the accelerator pedal raw signal is weighted with a weighting factor for smoothing. If unwanted instability is detected, an attempt can be made to smooth the accelerator pedal position. For this purpose, the accelerator pedal raw signal, which was recorded, for example, by the sensor, can be weighted or multiplied by a weighting factor. Thus, a modified or smoothed pedal value can be determined from the accelerator pedal raw signal. The fluctuations of the modified pedal value can then be significantly reduced compared to the accelerator pedal raw signal, depending on the detected, counted half-wave events. However, the driver still experiences a reaction to the accelerator pedal raw value change, only much more dampened.

[0016] According to a further embodiment, the smoothing of the accelerator pedal signal is omitted if the detection of an unsteady state fails. The smoothing of the accelerator pedal signal can also be stopped if the accelerator pedal position changes. Therefore, if a clear trend in the change in pedal position is discernible, the accelerator pedal signal can be used directly to control the drive motor and does not need to be smoothed beforehand. This reduces the loss of comfort and / or performance.

[0017] According to another embodiment, the smoothing of the accelerator pedal signal is omitted if the signal remains essentially constant for a predetermined duration. This predetermined duration can be static, dynamic, or determined or defined based on an applicable time scale. If the accelerator pedal position remains essentially constant within an applicable bandwidth and time frame, smoothing of the accelerator pedal signal can be omitted. This is particularly relevant when the accelerator pedal is not currently being pressed by the driver. In this case, control of the drive motor is unnecessary, thus significantly reducing emissions.

[0018] A device according to the invention serves to detect the position of the accelerator pedal of a motor vehicle. The device comprises a sensor for detecting a raw accelerator pedal signal, which describes the position of the accelerator pedal as a function of time. The device also includes a processing unit for smoothing the raw accelerator pedal signal. The processing unit is designed to determine half-waves of the raw accelerator pedal signal, to detect an irregularity during accelerator pedal actuation based on these half-waves, and to smooth the raw accelerator pedal signal when an irregularity is detected.

[0019] The preferred embodiments and their advantages presented with reference to the method according to the invention apply accordingly to the device according to the invention.

[0020] Further advantages, features, and details of the invention will become apparent from the following description of a preferred embodiment and from the drawing. The features and combinations of features mentioned above in the description, as well as those mentioned below in the figure description and / or shown in the figures alone, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention.

[0021] The invention will now be explained in more detail with reference to preferred embodiments and the accompanying drawing. The drawing shows: Fig. 1 a device for detecting the position of an accelerator pedal of a motor vehicle; Fig. 2 a throttle pedal signal which describes the position of the throttle pedal as a function of time; Fig. 3 weighting factors for smoothing the accelerator pedal raw signal; and Fig. 4 the accelerator pedal signal according to Fig. 2 compared to a smoothed accelerator pedal signal.

[0022] In the figures, identical and functionally equivalent elements are given the same reference symbols.

[0023] Fig. Figure 1 shows a schematic representation of a device 1 for detecting the position of an accelerator pedal 2 of a motor vehicle 3. The device 1 includes a sensor 4 with which the current position or angular position of the accelerator pedal 2 can be detected. Using the sensor 4, an accelerator pedal raw signal 7 (see Figure 1) can be transmitted to the device 1. Fig. 2) be provided. The accelerator pedal signal 7 provided by sensor 4 can be transmitted to a computing unit 5 of the device 1. In this case, the computing unit 5 is formed by an engine control unit, which can control a drive motor 6 of the motor vehicle 3. In particular, the power output of the drive motor 6 can be adjusted. Furthermore, the accelerator pedal signal 7 can be evaluated and, in particular, smoothed using the computing unit 5.

[0024] Fig. Figure 2 shows the accelerator pedal signal 7, which describes the position S of the accelerator pedal 2 as a function of time t. Particularly with inexperienced drivers, significant fluctuations can occur in the accelerator pedal signal 7. These fluctuations result from instability when the accelerator pedal 2 is actuated. This can be seen here from the time course of the accelerator pedal signal 7. The aim is to detect an instability during the actuation of the accelerator pedal 2. For this purpose, the computing unit 5 determines half-waves 8 of the accelerator pedal signal 7. The half-waves 8 describe oscillations of the accelerator pedal signal 7, or maxima and / or minima of the accelerator pedal signal 7. The instability can be detected, for example, if the number of half-waves 8 exceeds a predetermined limit within a predetermined time period.

[0025] When the predetermined state of instability is detected, the accelerator pedal raw signal 7 can be smoothed. For this purpose, the accelerator pedal raw signal 7 can, for example, be weighted with a weighting factor 13 depending on the counted half-wave events. This is described below. Fig. Figure 3 shows a schematic representation of a function that maps a modified accelerator pedal signal 9 or a smoothed accelerator pedal signal to the raw accelerator pedal signal 7. Such a function is known, for example, as "AADPS". This function weights the raw accelerator pedal signal 7 depending on a driving program.

[0026] The function for determining the weighting factor 13 describes an angle bisector 10, which does not modify the accelerator pedal raw signal 7. Furthermore, an upper envelope curve 11 and a lower envelope curve 12 are provided. For example, if a weighting value of 100 is present, the angle bisector 10 is selected. With a weighting value of 250, the upper envelope curve 11, or the maximum curve, is selected. With a weighting value of 0, the lower envelope curve 12, or the minimum curve, is selected. Using the lower envelope curve 12, for example, an accelerator pedal raw signal of 60% can be mapped to a modified accelerator pedal signal 9 of 30%. It is also intended that this known mapping structure for determining the weighting factor 13 will be used for the new application. In this case, the weighting factor 13 is gradually reduced to 0, depending on the half-wave count.This also allows the amplitude of pedal movements to be reduced. In this way, loss of comfort and thus resulting emissions can be reduced.

[0027] Fig. Figure 4 shows the waveform of the raw accelerator pedal signal 7 compared to the modified accelerator pedal signal 9. If the unstable condition is detected, the raw accelerator pedal signal 7 can be smoothed so that the modified accelerator pedal signal 9 is provided. In this case, the raw accelerator pedal signal 7 was smoothed after the fourth half-wave 8.

[0028] This has the advantage that at full load, i.e., at a pedal position S of 100%, this is directly implemented. At partial load points, the amplitude of the accelerator pedal raw signal 7 is significantly smoothed.

[0029] It is specifically intended that the smoothing of the accelerator pedal raw signal 7 can be reversed depending on predetermined parameters, in order to restore the driver's full potential. Such a parameter can exist, for example, if the position S of the accelerator pedal 2 or the accelerator pedal raw signal 7 is constant within an applicable bandwidth and an applicable time. Such a parameter also exists if the accelerator pedal position S is 0% for an applicable time. Reference symbol list 1 Device 2 Accelerator pedal 3 Motor vehicle 4 Sensor 5 Computer equipment 6 Drive motor 7 Accelerator pedal signal 8 half-wave 9 modified accelerator pedal signal 10 Angle bisectors 11 upper envelope curve 12 lower envelope curve 13 Weighting factor S position t time

Claims

[1] Method for detecting a position (S) of an accelerator pedal (2) of a motor vehicle (3) in which an accelerator pedal raw signal (7) describing the position (S) of the accelerator pedal (2) as a function of time (t) is detected and the accelerator pedal raw signal (7) is smoothed, characterized by , that half-waves (8) of the accelerator pedal raw signal (7) are determined, based on the determined half-waves (8) a state of instability is detected when the accelerator pedal (2) is actuated and the accelerator pedal raw signal (7) is smoothed if the state of instability is detected. [2] Method according to claim 1, characterized by , that the state of unrest is detected if a number of half-waves (8) exceed a limit value within a predetermined time period. [3] Method according to claim 1 or 2, characterized by, that the state of unrest is recognized based on a time interval between the half-waves (8) and / or based on an amplitude of the half-waves (8) and / or a distance of the amplitudes of the half-waves (8) from a mean value. [4] Method according to any one of the preceding claims, characterized by , that the accelerator pedal raw signal (7) is weighted with a weighting factor (13) for smoothing. [5] Method according to any one of the preceding claims, characterized by , that the smoothing of the accelerator pedal signal (7) will not occur if the detection of the unsteady state fails. [6] Method according to any one of the preceding claims, characterized by , that the smoothing of the accelerator pedal signal (7) is omitted if the accelerator pedal signal (7) is essentially constant for a predetermined minimum duration. [7] Device (1) for detecting a position (S) of an accelerator pedal (2) of a motor vehicle (3), comprising a sensor (4) for detecting an accelerator pedal raw signal (7) which describes the position (S) of the accelerator pedal (2) as a function of time (t), and comprising a computing device (5) for smoothing the accelerator pedal raw signal (7), characterized by , that the computing device (7) is designed to determine half-waves (8) of the accelerator pedal raw signal (7), to detect a state of instability when the accelerator pedal (2) is actuated based on the determined half-waves (8) and to smooth the accelerator pedal raw signal (7) when a state of instability is detected.

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