Method for setting a cruise control function with automatic distance adjustment in a single-track vehicle

Description

[0001] The invention relates to a method for setting a cruise control function with automatic distance adjustment in a single-track vehicle. State of the art

[0002] Adaptive cruise control functions are known, which automatically adjust the current vehicle speed depending on the distance to a vehicle ahead. The driver can set a target speed in the adaptive cruise control, whereby the actual vehicle speed may be lower and is based on the speed of the vehicle ahead. The distance to the vehicle ahead is usually detected using a radar system in the vehicle. See, for example, DE 10 2019 200 209 A1 or DE 10 2019 205 881 A1. Disclosure of the invention

[0003] The method according to the invention relates to setting a cruise control function with automatic distance adjustment in a single-track vehicle. The single-track vehicle is, in particular, a motor-driven single-track vehicle, preferably a motor-driven two-wheeler such as a motorcycle or scooter. When the cruise control function is activated, the speed of the single-track vehicle is automatically set to a target speed, with both acceleration and braking operations being carried out automatically. Due to the design as a cruise control function with automatic distance adjustment, the actual speed can be set depending on a vehicle traveling ahead, which is detected using a distance detection unit.The actual speed can be adjusted to the speed of the vehicle in front, with the following vehicle maintaining a speed-dependent distance from the vehicle in front.

[0004] The method according to the invention can be used for a group of single-track vehicles. With the cruise control function activated and a predefined target speed, the lateral distance between two leading single-track vehicles is first determined using the distance detection unit. The lateral distance indicates the lateral distance perpendicular to the longitudinal direction between the two leading single-track vehicles.

[0005] In a subsequent procedural step, a threshold value is determined, which is calculated as a function of the previously determined lateral distance between the two leading single-track vehicles. The lateral distance between the own single-track vehicle (hereinafter: ego vehicle) and a leading single-track vehicle, in particular the immediately preceding single-track vehicle, is then determined.

[0006] Finally, in a further method step, the single-track vehicle driving directly ahead is used as the target vehicle to be followed for the cruise control function in the event that the lateral distance between the ego vehicle and the single-track vehicle driving directly ahead is less than or equal to the threshold value.

[0007] This approach has the advantage that the cruise control function automatically decides whether the journey is a group ride and whether the ego vehicle, as part of the group, is following a single-track vehicle in front. This decision can be made using existing cruise control hardware with automatic distance adjustment; no additional hardware is required. If it is automatically detected that the journey is a group ride, to which the ego vehicle also belongs, the ego vehicle follows a single-track vehicle in front that is part of the group. If, on the other hand, the evaluation shows that the conditions specified for the ego vehicle to participate in the group ride are not met, which is the case if the threshold value is exceeded, the speed of the ego vehicle is not adjusted to the speed of the single-track vehicle in front.In this case, especially in the case of a higher target speed compared to the speed of the single-track vehicles ahead, the ego vehicle will overtake until the target speed is reached.

[0008] The lateral distance between the two leading single-track vehicles and between the ego vehicle and a leading single-track vehicle can be determined using a distance detection unit, which is part of an adaptive cruise control system for implementing the method. The distance detection unit is, in particular, a radar-based distance detection unit, with the aid of which both the longitudinal distance between the ego vehicle and one or more leading vehicles, as well as the lateral distance between two leading vehicles and between the ego vehicle and a leading vehicle can be determined. The resolution of the radar-based distance detection unit is good enough to determine both the longitudinal distance and the lateral distance.

[0009] The method according to the invention is applicable to situations in which at least two single-track vehicles are traveling in front of the ego vehicle. More than two single-track vehicles may be in front of the ego vehicle. Using the sensors in the ego vehicle, which are part of the distance detection unit, the lateral distance between two immediately preceding single-track vehicles and between the ego vehicle and the next preceding single-track vehicle is determined.

[0010] According to an advantageous embodiment, the threshold value used to compare the lateral distance between the ego vehicle and the leading single-track vehicle is set to a value greater than the lateral distance between the two leading single-track vehicles. For example, the threshold value is at least 10%, at least 20%, at least 30%, at least 40%, or at least 50% greater than the lateral distance between the two leading single-track vehicles. By setting the threshold value to a value greater than the lateral distance, there is a sufficiently large tolerance for the ego vehicle to join the group ride and attach itself to the leading single-track vehicle.

[0011] According to yet another advantageous embodiment, the threshold is limited to a maximum value. This ensures that the ego vehicle is only recognized as belonging to the group if it is within a limited lateral distance. A distinction can be made between a group and an overtaking maneuver. The maximum value is set, for example, to the roadway width or lane width of the road on which the preceding single-track vehicles are currently traveling.

[0012] According to yet another advantageous embodiment, the method steps are performed at regular intervals, so that the threshold value is adjusted accordingly and the query is carried out as to whether the ego vehicle should follow the leading single-track vehicle. This query can be used to detect situations in which the group travel breaks up, for example, when one or more leading single-track vehicles pull out. It is also possible to detect other changing conditions, such as the threshold value being exceeded due to an increasing lateral distance between the ego vehicle and the leading single-track vehicle.

[0013] According to yet another advantageous embodiment, the threshold value can additionally be determined as a function of further parameters or system variables, in particular as a function of a road characteristic such as the road type or road width. For example, when driving on motorways, the threshold value can be limited to a higher maximum value than when driving on smaller roads, particularly in cities. The road type can be detected, for example, using a navigation system or a traffic sign recognition system. The current road width results, on the one hand, from the road type; on the other hand, the road width can also be detected via sensors in the ego vehicle, regardless of the detection of the road type.

[0014] The process steps run in a control unit that is part of an adaptive cruise control system in the ego vehicle or installed independently of the adaptive cruise control system in the ego vehicle. The control unit can be used, in particular, to evaluate sensor information from the distance detection unit and automatically adjust the speed of the ego vehicle by controlling the drive motor and, if necessary, a braking system in the ego vehicle.

[0015] The invention also relates to an adaptive cruise control system in a single-track vehicle, comprising a control unit as described above, a device for automatic speed adjustment, and a distance detection unit for detecting the longitudinal distance to a leading single-track vehicle and for detecting the lateral distance between two single-track vehicles, both traveling in front of the ego vehicle, or the lateral distance between the ego vehicle and a leading vehicle. The device for automatic speed adjustment can be formed by the control unit itself, in which control signals are generated to actuate the drive motor and the braking system.

[0016] Finally, the invention relates to a single-track vehicle such as a motorcycle or a scooter, which is equipped with a distance cruise control device as described above.

[0017] The invention also relates to a computer program product with a program code designed to execute the method steps described above. The computer program product runs in a control unit described above.

[0018] Further advantages and practical embodiments can be found in the further claims, the description of the figures, and the drawings. They show: Fig. 1a a top view of three motorcycles, all riding in a group, Fig. 1b a top view of the three motorcycles, with the third, following motorcycle preparing to overtake, Fig. 2a, 2b further top views as in Fig. 1a, 1b , but with a larger lateral distance between the two motorcycles in front, Fig. 3 a flow chart with process steps for setting a cruise control function with automatic distance adjustment in a single-track vehicle.

[0019] In the figures, identical components are provided with the same reference symbols.

[0020] In Fig. 1a is a plan view of a group of single-track vehicles designed as motorcycles and traveling along a lane of a road 1. The two leading motorcycles 2 and 3 are traveling offset one behind the other and have a lateral distance x 1 from each other, based on the longitudinal extent of the road 1 and the direction of travel of the motorcycles. The following motorcycle 4 is equipped with a cruise control function with automatic distance adjustment, which allows it to follow one of the preceding motorcycles 2, 3, in particular the immediately preceding motorcycle 3, if necessary. The longitudinal distance between the preceding motorcycle 3 and the following single-track vehicle 4 (ego vehicle) is determined using a distance detection unit, which in particular comprises a radar system.The distance detection unit also allows the determination of both the lateral distance x 1 between the two preceding motorcycles 2 and 3 and the lateral distance x 2 between the immediately preceding vehicle 3 and the ego vehicle 4. When the cruise control function is activated with a predefined target speed that is higher than the speed of the preceding motorcycles 2, 3, the ego vehicle 4 can, depending on the lateral distance x 2, either overtake or travel in a group with the preceding motorcycles 2, 3.

[0021] The detection of whether the two motorcycles 2, 3 traveling ahead, together with the ego vehicle 4, form a group in which the ego vehicle 4 is moving, is made by comparing the current lateral distance x2 between the ego vehicle 4 and the immediately preceding motorcycle 3 with a threshold value a, which is determined as a function of the lateral distance x1 between the two motorcycles 2, 3 traveling ahead. It is expedient for the threshold value a to be greater than the lateral distance x4 between the motorcycles 2, 3. The threshold value a can, for example, be half the size of the lateral distance x1, but limited to a maximum value, for example the roadway width or lane on which the motorcycles 2, 3, 4 are traveling on the road 1.

[0022] In Fig. 1a A driving situation is depicted in which the lateral distance x 2 between the ego vehicle 4 and the immediately preceding motorcycle 3 is smaller than the previously determined threshold value a, which is determined as a function of the lateral distance x 1 between the two preceding motorcycles 2, 3. In this case, a group ride is assumed, whereupon the cruise control function with automatic distance adjustment is implemented in such a way that the ego vehicle 4 attaches itself to the immediately preceding motorcycle 3 as the target vehicle and follows it. Accordingly, the speed of the ego vehicle 4 is adjusted via the cruise control function by controlling the drive motor in the ego vehicle 4 and, if applicable, the braking system.

[0023] In Fig. 1b A variant is shown with the same initial situation of the preceding motorcycles 2 and 3, which have a lateral position x 1 to each other, from which the threshold value a is determined. In contrast to Fig. 1a but is at Fig. 1b the lateral distance x 2 between the ego-vehicle 4 and the immediately preceding motorcycle 3 is greater than the threshold value a. In this case, it is not assumed that a group ride is taking place, but rather that the ego-vehicle 4 is overtaking. Accordingly, the current speed of the ego-vehicle 4 is not adjusted to the speed of the preceding motorcycle 3, but rather the ego-vehicle 4 is accelerated to the set target speed, which is higher than the speed of the preceding motorcycle 3.

[0024] In Fig. 2a a driving situation with three motorcycles 2, 3, 4 on a road is shown, which basically corresponds to the driving situation according to Fig. 1a However, Fig. 2a The lateral distance x 1 between the two leading motorcycles 2, 3 is larger, and the lateral distance x 2 between the ego vehicle 4 and the immediately preceding motorcycle 3 is also larger. The threshold value a, which approximately corresponds to the road width, is calculated from the lateral distance x 1. Since the threshold value a is larger than the lateral distance x 2 between the ego vehicle 4 and the immediately preceding motorcycle 3, it is assumed that the vehicle is traveling in a group, and the speed of the vehicle 4 is adjusted to the speed of the immediately preceding motorcycle 3.

[0025] In Fig. 2b , in which the two motorcycles 2, 3 in front have the same distance x 1 as in Fig. 2a the lateral distance x 2 of the ego vehicle 4 to the immediately preceding motorcycle 3 is greater than the threshold value a, so that a group ride is not assumed and the ego vehicle 4 does not attach itself to the preceding motorcycle 3. Rather, an overtaking maneuver is assumed in which the ego vehicle 4 accelerates to the set target speed.

[0026] Fig. 3 shows a flowchart for implementing the procedural steps for setting the cruise control function. The flowchart is based on the activation of the cruise control function in the ego vehicle and the setting of a target speed in the cruise control function.

[0027] First, in a first method step V1, the lateral distance x 1 between two motorcycles traveling ahead is determined. Subsequently, in the next method step V2, a threshold value a is determined, which is determined as a function of the lateral distance x 1. It is expedient to set the threshold value a to a value greater than the lateral distance x 1, but limited to a maximum value, which is in particular half the lane width. If necessary, other variables can be taken into account when determining the threshold value a, for example the road type, such as motorway, country road, or local road.

[0028] In the following process step V3, the current lateral distance x 2 between the ego vehicle and the immediately preceding motorcycle is determined. In process step V4, a query is then made as to whether the lateral distance x 2 between the ego vehicle and the immediately preceding motorcycle is less than or equal to the threshold value a. If this is the case, the system proceeds to the next process step V5 following the "Yes" branch, according to which the motorcycles are traveling in a group and the ego vehicle is following the immediately preceding motorcycle.

[0029] If, however, the query in process step V4 reveals that the lateral distance x 2 is greater than the threshold value a, then group travel cannot be assumed. In this case, the "No" branch ("N") is followed by process step V6, in which it is assumed that the ego vehicle is overtaking and that the target speed set in the cruise control function is reached in the ego vehicle.

[0030] After both process step V5 and process step V6, the system returns to process step V1 and repeats the entire process at cyclical intervals.

[0031] The various process steps run in a control unit, which can be part of a distance control system in a single-track vehicle. This also includes a distance detection unit for detecting the longitudinal distance to a vehicle ahead and the lateral distance between two single-track vehicles. After evaluating all the information, the control unit can generate control signals for adjusting the drive motor and, if necessary, the braking system.

Claims

1. Method for setting a cruise control function with automatic distance adjustment in a single-track vehicle (2, 3), having the following method steps: a) determining the lateral distance (x1) between two single-track vehicles (2, 3) ahead; b) identifying a threshold value (a) as a function of the lateral distance (x1) between the two single-track vehicles (2, 3) ahead; c) determining the lateral distance (X2) between the ego single-track vehicle (4) and a single-track vehicle (3) ahead; d) using the single-track vehicle (3) ahead as the target vehicle to be followed for the cruise control function if the lateral distance (x2) between the ego single-track vehicle (4) and the single-track vehicle (3) ahead is less than or equal to the threshold value (a).

2. Method according to Claim 1, characterized in that the threshold value (a) is set to a greater value than the lateral distance (x1) between the two single-track vehicles (2, 3) ahead.

3. Method according to Claim 1 or 2, characterized in that the threshold value (a) is limited to a maximum value, for example to the road width of the road (1) on which the single-track vehicles (2, 3, 4) are currently moving.

4. Method according to one of Claims 1 to 3, characterized by regular performance of the method steps comprising determination and, if necessary, adjustment of the threshold value (a), the lateral distance (X2) between the ego single-track vehicle (4) and a single-track vehicle (3) ahead and the lateral distance (x1) between two single-track vehicles (2, 3) ahead.

5. Method according to one of Claims 1 to 4, characterized in that a target speed is specified in the cruise control function, to which the vehicle is accelerated if the lateral distance (x2) between the ego single-track vehicle (4) and the single-track vehicle (3) ahead is greater than the threshold value (a).

6. Method according to one of Claims 1 to 5, characterized in that the threshold value (a) is additionally determined on the basis of a road characteristic, for example on the basis of the road type or the road width.

7. Control unit for carrying out the method according to one of Claims 1 to 6.

8. Adaptive cruise control device in a single-track vehicle (2, 3, 4), comprising a control unit according to Claim 7, comprising a device for automatic speed adjustment and comprising a distance detection unit for detecting the longitudinal distance from a single-track vehicle (2, 3, 4) ahead and for detecting the lateral distance between two single-track vehicles (2, 3).

9. Single-track vehicle, in particular motorcycle, comprising an adaptive cruise control device according to Claim 8.

10. Computer program product comprising program code designed to carry out steps of the method according to one of Claims 1 to 6 when the computer program product runs in a control unit according to Claim 7.