METHOD FOR CONTROLLING A DISTANCE-DEPENDENT CRUISE CONTROL SYSTEM

Abstract

A method for controlling a distance-dependent cruise control system for a motor vehicle, pieces of distance information and/or pieces of velocity information of a target object being combined with pieces of context information. The velocity of the motor vehicle is controlled as a function thereof.

Claims

1. A method for controlling a distance-dependent cruise control system for a motor vehicle, the method comprising: combining pieces of distance information and/or pieces of velocity information of a target object combined with pieces of context information; and controlling the velocity of the motor vehicle being controlled as a function of the combination.

2. The method as recited in claim 1, wherein the pieces of context information are obtained via a video system of the motor vehicle.

3. The method as recited in claim 1, wherein the pieces of context information include pieces of information about traffic infrastructure.

4. The method as recited in claim 1, wherein the pieces of context information include pieces of information about signaling systems and their switch states.

5. The method as recited in claim 1, wherein the pieces of context information include pieces of information about one or multiple of the following traffic infrastructures: traffic sign; railroad crossing; crosswalk; traffic island; traffic circle; intersection or junction with “priority to the right” rule; roadway markings; stop lines; and lane markings and turn arrows.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Exemplary embodiments of the present invention are shown in the FIGURE and are described in greater detail in the following description.

[0029] The FIGURE shows a flowchart of one exemplary embodiment of the method according to the present invention.

SUMMARY

[0030] The following exemplary embodiments relate to a motor vehicle which includes an adaptive cruise control system and a video system including a frontally oriented video sensor.

[0031] The video sensor records, on the one hand, pieces of target information TO, i.e., pieces of information about the distance and/or the velocity of the vehicle situated ahead thereof, and, on the other hand, pieces of context information CI. The relevant context is ascertained 1 from the pieces of context information CI. When the motor vehicle approaches a traffic light in one example, the traffic light and its switch state are initially recognized from a larger distance, for example from more than 200 m. If stationary target objects are detected from the pieces of target information TO, it may be assumed that these are waiting at a red traffic light. An object detection in a camera image is dependent, in its detection range, on the real object size. For example, a motor vehicle has a width of approximately 1.8 m, while a traffic light is only 0.2 m wide. For this reason, it is possible to recognize a motor vehicle already from a larger distance than a traffic light, for example 100 m earlier. Moreover, it is to be assumed that, based on typical traffic rules, parking is not permitted in the area ahead of traffic lights. The adaptive cruise control system carries out a slight deceleration of the motor vehicle.

[0032] If no context relevant for the regulation is detected during the ascertainment 1, the regulation of the velocity is carried out 2 regardless of the context. If a relevant context is detected, initially the context type is established 3. The context type results from the sum of the pieces of context information CI or the pieces of surroundings information. The following context types are listed here by way of example, it also being possible for further context types to be provided: [0033] a traffic light TL including its switch states R, G, Y; [0034] a street arrow SA; [0035] a traffic sign TS; [0036] a parking vehicle PV.

[0037] If the context type is established 3, for example, to be a traffic light TL, the switch state of traffic light TL is recognized 4. In this example, the switch state of traffic light TL is limited to red R, yellow Y, and green G for simplification. If traffic light TL shows red R, the deceleration of the motor vehicle is continued 5 until the motor vehicle comes to a halt behind the vehicle situated ahead thereof. If traffic light TL shows green G, the deceleration is reduced 6, if the distance with respect to the target object is still large enough, since it may be expected that the vehicle situated ahead will start. If traffic light TL shows yellow Y, the regulation takes place as a function of whether the transition from red R to yellow Y or from green G to yellow Y has taken place. Oftentimes this is apparent in the case of traffic lights TL from the fact that the preceding color is also displayed, in particular in the case of the combination red-yellow. During a transition from green G to yellow Y, the deceleration is continued 7 since it may be assumed that the vehicle situated ahead will stop at traffic light TL. During a transition from red R to yellow Y, the deceleration is reduced 8, if the distance with respect to the target object is still large enough, since it may be expected, as in the case of green G, that the vehicle situated ahead will start. If the driver takes over the control, it is additionally pointed out to the driver that the switch state of traffic light TL has changed, for example by a corresponding display.

[0038] If establishment 3 of the context type shows a parking vehicle PV as the target object, in particular without a traffic light TL being present, the target object is not taken into consideration 9 during the regulation as long as safe stopping is still possible with a predefined maximum deceleration, for example, 3.5 m/s.sup.2. If the point at which safe stopping is just barely still possible is reached, the motor vehicle is brought to a halt 10 in a timely manner using a comfort maneuver. If the driver reacts before that, no regulation is carried out by the adaptive cruise control system. Moreover, further pieces of information may be utilized for a better analysis of the situation. For example, potentially present oncoming traffic may be detected and/or the lane or roadway width may be ascertained. From these pieces of information, a bottleneck may be detected, which the motor vehicle is not able to pass, and early stopping may be regulated. An early warning of the driver is also possible.

[0039] If the context type is established 3 to be a street arrow SA, the arrow, most notably the form (single arrow, double arrow) and the indicated direction, are recognized 11. A regulation of the velocity is then carried out 12 corresponding to street arrow SA.

[0040] If the context type is established 3 to be a traffic sign TS, the traffic sign, most notably the outer shape, the color and/or the depicted forms or pictograms, are recognized 13. A regulation of the velocity is then carried out 14 corresponding to traffic sign TS.

[0041] Moreover, pieces of information from a map may be integrated into the system. In the process, pieces of context information, for example about traffic signs, stop lines and/or underlying traffic rules such as “priority to the right” are obtained.

[0042] In this exemplary embodiment of the present invention, the evaluation for each time step takes place individually. In other exemplary embodiments, it is also possible for a temporal smoothing of the control variables, and thus of the vehicle behavior, to take place. The smoothing may be easily integrated into the existing control system. In still other exemplary embodiments, a temporal consideration of the scenarios takes place. This results in a further improvement of the overall system, beyond the pure smoothing of the vehicle reaction. As examples, regulations 5 through 8 could be adapted by assessing the duration of switch states R, G, Y of traffic light TL in that, for example, the deceleration 5 is less in the case of a red phase R that has already lasted a long time than directly after the transition to red R.