Method for setting the speed of a speed control device of a motor vehicle, and such a speed control device

Abstract

The invention relates to a method for setting the specified driving speed as a reference variable of a speed control device of a motor vehicle, wherein the speed control device has an operating element which is accessible to a vehicle driver during driving and which allows the input of a fine adjustment and a rough adjustment of the specified driving speed, wherein the method comprises the steps of: the speed control device determining the number of fine adjustment inputs within a time window; the speed control device checking whether the number of inputs exceeds a threshold value; if the number of inputs exceeds the threshold value, the speed control device interpreting the inputs as a rough adjustment. The invention also relates to a speed control device in which such a method is able to be carried out.

Description

[0001] Method for adjusting the speed of a cruise control device of a motor vehicle and such a cruise control device

[0002] The invention relates to a method for adjusting the speed of a cruise control device of a vehicle and to such a method.

[0003] Cruise control systems in motor vehicles serve to maintain a driver-specified speed as a guideline whenever possible. Typically, controls are provided on the steering wheel for the driver to set the desired speed. This can be achieved, for example, by using the vehicle's current speed as the target speed. It is also possible to change a previously set speed. This is usually accomplished using pushbuttons, VIP switches, toggle switches, or similar devices that allow for both coarse and fine adjustments of the speed. One possibility is that, for example, a short press of a pushbutton is interpreted as a fine adjustment, while a longer press is interpreted as a coarse adjustment.Other systems allow the actuator to assume two positions. Accordingly, the first position can be interpreted as a fine adjustment input and the second position as a coarse adjustment input.

[0004] In ferry operations, situations can arise where the driver is not fully familiar with the vehicle's controls. This can occur, for example, when taking over and operating a rental vehicle. Stressful or emergency situations can also occur, in which the driver may not have full knowledge of all the controls' functionalities. Under these circumstances, the driver might attempt to roughly adjust the desired speed by repeatedly using the fine-adjustment function of the control. In such a case, the speed will only change slightly, even though the driver intends to make a quick adjustment. This can confuse the driver and potentially create or exacerbate a dangerous situation.

[0005] It is an object of the present invention to provide a method for setting the speed of a cruise control device of a motor vehicle that is easy and intuitive to use for an inexperienced driver or a driver in a stressful driving situation, thereby improving safety. This object is achieved by a method for setting the speed according to independent claim 1. The method according to the invention is provided for a cruise control device that has a control element accessible to a driver, which allows the input of a fine adjustment and the input of a coarse adjustment of the currently set driving speed.The procedure comprises the following steps: Determining, by the cruise control device, the number of fine adjustment inputs within a specific time window; Checking, by the cruise control device, whether the number of inputs within the specific time window exceeds a threshold; if the number of inputs exceeds the threshold, interpreting the fine adjustment inputs as coarse adjustments by the cruise control device.

[0006] This improves user-friendliness, as a larger speed adjustment is achieved when the fine-tuning control is used. This increases driver safety, as the desired adjustment to the currently set driving speed is reached more quickly, thus requiring less driver attention.

[0007] In one embodiment, after the inputs have been interpreted as a coarse adjustment, subsequent inputs are ignored during a further time window.

[0008] This avoids unintentional speed changes while the coarse adjustment has already been carried out.

[0009] In a preferred embodiment, the threshold value depends on the driving condition of the vehicle, in particular on its current driving speed.

[0010] This improves the system's adaptability, as the threshold for converting from fine to coarse adjustments can be adjusted to the driving conditions. This results in a situation-appropriate response from the system. For example, in driving conditions where fine adjustments of a few units are frequently required, the threshold can be raised.

[0011] Overall, the system enables sensitive control at high speeds and more robust control at low speeds, thus helping to improve control over the vehicle.

[0012] In a further advantageous embodiment, it can be provided that, when interpreting the inputs as coarse adjustments, the adjustment value for the coarse adjustment depends on the vehicle's driving condition. This driving condition could, for example, be the vehicle speed. Thus, similar to adjusting the threshold value, the fine adjustment can respond appropriately to the driver's inputs. For example, a higher adjustment value can be achieved at a higher speed than at a lower speed.

[0013] In a preferred embodiment, it can be provided that the fine adjustment causes an increase or decrease of the predetermined driving speed by a fine increment and the coarse adjustment causes an increase or decrease of the predetermined driving speed by a coarse increment, wherein the fine increment is smaller than the coarse increment.

[0014] For example, the coarse increment can be a multiple of the fine increment, such as five or ten times the fine increment. In terms of speed, this could be, for example, 10 km / h and 1 km / h or 10 mph and 1 mph.

[0015] The task can also be solved by a speed control device for a motor vehicle, in which the procedure described above can be carried out.

[0016] Exemplary embodiments of the invention are explained in more detail below with reference to the drawings. These show:

[0017] Figure 1 shows the interior of a motor vehicle and

[0018] Figure 2 shows a flowchart of an embodiment according to the invention.

[0019] Figure 1 illustrates the interior of a motor vehicle 10. The motor vehicle has a steering wheel 12 in a known manner. A control element 14 is attached to the steering wheel 12, which can be used to operate a cruise control device 16. The control element 14 is a rocker switch that can be deflected upwards and downwards. There are essentially two positions for deflection. Operating the control element 14 by deflecting the rocker switch initially reaches a first position, which serves for fine adjustment of a preset driving speed specified by the cruise control device 16. Moving the rocker switch 14 beyond the first position corresponds to a coarse adjustment of the current driving speed. Moving the rocker switch 14 upwards increases the driving speed. Moving the rocker switch 14 downwards decreases the driving speed.

[0020] Specifically, it could be configured, for example, that a fine adjustment to increase the preset driving speed increases the speed by 1 km / h, while a coarse adjustment increases it by 10 km / h. Conversely, a user input used for fine adjustment to decrease the driving speed reduces the speed by 1 km / h. A corresponding input used for coarse adjustment to decrease the driving speed reduces the speed by 10 km / h.

[0021] Figure 2 illustrates an embodiment of the method for adjusting the speed of a cruise control device 16 of a motor vehicle 10. The method comprises the steps:

[0022] After starting at SO, a counter is reset in step S1. This counter records how often control element 14 is pressed in one direction, either to increase or decrease the currently set driving speed. In step S2, it is checked whether control element 14 has been pressed. If it is not, the check continues with step S3, meaning it continuously checks whether control element 14 has been pressed.

[0023] If the fine adjustment control is pressed, step S4 checks whether the counter has a value greater than 0. If the counter is 0, step S5 starts an interpretation time window. During this time window, step S6 increments the counter by one unit, and step S7 checks whether the interpretation time window has expired. If so, step S1 restarts the process by resetting the counter.

[0024] If the interpretation time window has not yet expired, step S8 checks whether the counter has exceeded a threshold. If not, the process continues with step S2, and it is checked again whether control element 14 has been pressed.

[0025] If, however, the counter reaches a threshold value, in step S9 the number of fine adjustment actuations of the control element 14 accumulated during the interpretation time window is interpreted as a coarse adjustment and the currently specified driving speed is adjusted accordingly.

[0026] Step S10 then starts a debouncing window. During this window, no input is possible via control element 14. Step S11 checks whether the debouncing window has expired. If not, the process continues waiting for the debouncing window to expire. If it has, the procedure continues with step S1, i.e., the counter is reset. The speed control function described here can count the number of fine-adjustment inputs from control element 14 within a specific short time period and interpret these as coarse-adjustment inputs when a preset threshold is reached. The threshold for the number of fine-adjustment inputs, as well as the time within which these fine-adjustment inputs must occur, can be determined, for example, based on usability studies.For the system to function, only a single counter is required to record the number of fine-adjustment inputs, along with a time window within which it is checked whether the input threshold has been exceeded. It is advantageous to implement a debouncing time window after several fine-adjustment inputs have been interpreted as coarse-adjustment inputs, during which further fine-adjustment inputs are suppressed for a short time. For example, if three fine-adjustment inputs are interpreted as one coarse-adjustment input, the fourth fine-adjustment input is ignored during the debouncing time window.

[0027] The table below illustrates an example of an interpretation process. In this example, the current set speed of the cruise control system is 100 km / h. The driver operates control element 14 three times within one second to increase the speed by 1 km / h. This is interpreted as a coarse adjustment input, and the set speed is increased by 10 km / h from the speed that was set before the first fine adjustment input. The inputs to control element 14 occur approximately 0.3 seconds apart.

Claims

Claims 1. A method for setting the predetermined driving speed as a control variable of a cruise control device of a motor vehicle, wherein the cruise control device has a control element accessible to a driver while driving, which allows the input of a fine adjustment and a coarse adjustment of the predetermined driving speed, wherein the method comprises the steps: Determine (S4), by the speed control device, the number of fine adjustment inputs within a time window; Check (S8) by the cruise control device whether the number of inputs exceeds a threshold; if the number of inputs exceeds the threshold, interpret (S9) the inputs by the cruise control device as a coarse adjustment.

2. Method according to claim, wherein after interpreting the inputs as a coarse adjustment, subsequent inputs are ignored during a further time window (S11).

3. Method according to one of the preceding claims, wherein the threshold depends on the driving condition of the vehicle.

4. Method according to claim, wherein the threshold depends on the vehicle speed.

5. Method according to one of the preceding claims, wherein, when interpreting the inputs as a coarse adjustment, an adjustment value depends on the current driving condition.

6. Method according to one of the preceding claims, wherein the fine adjustment causes an increase or decrease of the predetermined driving speed by a fine increment and the coarse adjustment causes an increase or decrease of the predetermined driving speed by a coarse increment, wherein the fine increment is smaller than the coarse increment.

7. The method of claim 6, wherein the coarse increment is a multiple of the fine increment, for example a multiple of five or a multiple of ten.

8. Cruise control device (16) for a motor vehicle (10) in which a method according to one of the preceding claims is executable.

9. Computer program with instructions which, when executed on a The data processing system is executed such that the data processing system performs the steps according to a method of the preceding claims 1-7:

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