Procedure and control unit for a motor vehicle

Abstract

Method for a motor vehicle (10), wherein the motor vehicle (10) comprises a sensor unit (12) for scanning a vehicle environment and a speed control system (14), and the method comprises the steps: - Operating (50) the motor vehicle (10) in cruise control mode at a specific set speed, - Detection (52) of an actuation of the accelerator pedal (16) of the motor vehicle (10), - Determining (54) a special situation of the motor vehicle (10) using the sensor unit (12) and based on a detected activation of the turn signal of the motor vehicle (10), wherein the special situation includes a lane change of the motor vehicle (10) and corresponds to a driving situation which requires a momentary deviation from the set speed of the cruise control system (14) to cope with the driving situation and / or in which an increase in the set speed exceeds a permissible speed or a recommended speed, and - Maintaining (56) the cruise control operation with the specified set speed in response to the application of the accelerator pedal (16) of the motor vehicle (10) and determining a special situation.

Description

[0001] The invention relates to a method and control unit for a motor vehicle.

[0002] Driving a motor vehicle for extended periods can be very tiring for the driver. To address this problem, driver assistance systems have been developed. One such system is cruise control. Cruise control is a speed control system that regulates a vehicle's speed by maintaining a specific set speed. Adaptive cruise control (ACC) systems are also available. With adaptive cruise control, the area in front of the vehicle is scanned using cameras, radar, or lidar sensors (or in some cases, a combination of these devices). If an obstacle is detected in front of the vehicle, a braking command is sent to the cruise control system. Adaptive cruise control thus serves the additional purpose of maintaining a specific distance or a specific time to the vehicle ahead.The specific distance can, for example, be time-dependent, i.e., represent a function of time.

[0003] Current operating concepts for familiar cruise control systems allow the set speed to be adjusted, for example, via a switch on the steering wheel. Another approach uses surround-view cameras for traffic sign recognition. If a traffic sign indicating a speed limit is detected, the set speed is adjusted to that speed. Yet another operating concept involves increasing the set speed by pressing the accelerator pedal. This means the driver accelerates the vehicle using the accelerator pedal and releases it once the desired speed is reached. The vehicle's speed at that point is then used as the new set speed.

[0004] The latter operating concept, in particular, is not equally suitable for all driving situations. Depending on the situation, for example during an overtaking maneuver, a driver only intends a situation-specific, short-term increase in the vehicle's speed, namely for the duration of the overtaking maneuver. Adopting the increased speed resulting from the overtaking maneuver as the new set speed would not be in the driver's interest. Therefore, there is a need to improve the existing operating concepts of cruise control systems.

[0005] An example of a known method and device for assisting a lane change maneuver for a vehicle equipped with a cruise control system is described in US Publication 2021 / 0331672 A1. Using acquired environmental data, it is proposed therein to determine the current traffic density and flow rate on a target lane and to adjust the cruise control system's set speed to the flow rate.

[0006] German patent application DE 10 2020 207 313 A1 discloses a driver assistance system for a motor vehicle, which is controllable by means of a pedal assembly. The pedal assembly comprises pedals that are adjustable from their rest position by two further actuation positions in order to control the driver assistance system and a motor vehicle system different from the driver assistance system. Another example of a method and a device for vehicle control is shown in German patent application DE 196 54 769 A1.

[0007] The invention is therefore based on the objective of providing a method for a motor vehicle and a control unit for a motor vehicle which enables improved operation of a cruise control system.

[0008] The problem according to the invention is solved by a method and a control unit for a motor vehicle according to the independent claims. Preferred embodiments are the subject of the respective dependent claims.

[0009] A first aspect concerns a method for a motor vehicle. The motor vehicle comprises a sensor unit for scanning the vehicle's surroundings and a speed control system. The sensor unit preferably comprises a camera, radar, and / or lidar system for scanning the vehicle's surroundings. The sensor unit further comprises a storage unit on which, in particular, information about traffic signs, lanes, and / or swarm data, such as trajectories and / or average speeds on road segments, is stored. Preferably, the motor vehicle comprises a navigation system with satellite-based location recognition (for example, GPS) and stored road maps with associated maximum speed limits and / or recommended speeds. The speed control system is preferably a cruise control or an adaptive cruise control system (ACC).

[0010] In one process step, the vehicle is operated in cruise control mode at a specific set speed. This set speed is, for example, a speed specified by the driver.

[0011] In a further step of the method according to the invention, the activation of the vehicle's accelerator pedal is detected. Preferably, the activation of the accelerator pedal leads to an adjustment, in particular an increase, of the specified set speed, for example by +3 km / h or +10 km / h. In another embodiment, the set speed is set to the current speed of the vehicle at the time the accelerator pedal is released. If no activation of the accelerator pedal is detected, the cruise control operation is maintained at the specified set speed (until no longer requested by the driver).

[0012] In a further process step, a special situation of the vehicle is determined using the sensor unit. Preferably, the special situation is determined in response to the detected actuation of the accelerator pedal. The special situation corresponds to a driving situation that requires a brief deviation from the set speed of the cruise control system to manage the driving situation (in particular, to avoid accidents and / or be comfortable) and / or in which increasing the set speed would exceed a permissible speed or a recommended speed. A brief deviation is preferably a deviation for a period of less than one minute, preferably less than 30 seconds, particularly preferably less than 15 seconds, and especially 5 to 10 seconds.In other words, a special situation describes a driving situation in which the driver, while changing the vehicle's speed, does not intend to also change the set speed. If, for example, no special situation is detected, the cruise control operation is preferably terminated, or the set speed is preferably adjusted in response to the accelerator pedal being pressed.

[0013] In a further step of the method according to the invention, the cruise control operation with the set speed is maintained in response to the application of the accelerator pedal of the motor vehicle and (in response to) the detection of a special situation. In other words, an adjustment of the set speed in response to the application of the accelerator pedal of the motor vehicle is prevented when a special situation has been detected (i.e., the cruise control operation is maintained). According to the invention, the operation of the cruise control system is improved because the set speed is not adjusted (bluntly) every time, but rather the set speed is maintained when the driver (obviously) does not intend to adjust the set speed.

[0014] Furthermore, it is provided that the special situation includes a lane change by the vehicle. This special situation is determined based on the detection of the vehicle's turn signal activation and preferably also based on the detection of the accelerator pedal activation. The turn signal activation can be detected, for example, as a brief or momentary action. The accelerator pedal activation can indicate an intention to accelerate, and the turn signal activation can indicate an intention to change lanes. Even a brief flash of the turn signal is preferably sufficient to detect the intention to change lanes. An intention to change lanes can, in particular, indicate a lane change such as an overtaking maneuver, a merging maneuver, an exit maneuver, and the like.In particular, the combination of accelerator pedal activation and turn signal activation can be used to indicate an overtaking maneuver, i.e., to signal an intention to overtake. Merging, for example, is the process of a vehicle merging into the flow of traffic in another lane. Merging may require a brief acceleration of the vehicle to (safely) fit into a gap between two vehicles in an adjacent lane. Exiting, for example, is a driving situation in which the driver intends to exit the road, but the exit is blocked by a vehicle in the current lane or another lane.In this situation, either braking or accelerating of the motor vehicle is necessary to reach the road exit in time and safely, although an increase in the set speed is generally not intended.

[0015] Preferably, in a further step, a lane change initiated or completed from the originally driven lane to an adjacent lane is detected using the sensor unit. For this purpose, for example, the lane markings can be detected by the sensor unit, and the vehicle's crossing of the lane marking (especially a dashed lane marking) is recorded as an initiated or completed lane change. Preferably, the determination of the vehicle's special situation is further based on the detected initiated or completed lane change. Detecting a lane change increases the confidence in the determined special situation, especially the overtaking request or process. Accordingly, the occurrence of incorrect speed setting can be reduced.

[0016] It is also preferred that a subsequent lane change from the adjacent lane back to the originally driven lane be detected using the sensor unit. The detection of this subsequent lane change can be performed analogously to the detection of the lane change mentioned above. Preferably, the determination of the vehicle's special situation is further based on the detected subsequent lane change. Detecting a subsequent lane change back to the originally driven lane increases the confidence in the determined special situation, particularly the confirmation of a completed overtaking maneuver. Accordingly, the occurrence of incorrect speed setting can be further reduced.Particularly preferred is the maintenance of the speed control operation with the specified setting speed in response to a drop below the actual setting speed due to the actual speed after the overtaking maneuver, i.e., when the actual speed after the overtaking maneuver falls below the actual setting speed.

[0017] In a further preferred embodiment, the sensor unit detects another road user and / or the road classification of the road being traveled. Preferably, the determination of the special situation of the motor vehicle is also based on the detected other road user and / or the detected road classification. For example, it can be assumed that a detected other road user in front of the motor vehicle and a detected activation of the turn signal indicate an intention to overtake and, in particular, in conjunction with a detected activation of the accelerator pedal, a started overtaking maneuver.If no other road user is detected and the driver presses the accelerator pedal, it can be assumed that the driver actually intends to increase the set speed. Therefore, based on the detection of other road users or a clear vehicle environment, inferences can be drawn about the driver's intentions. Based on the road classification, such as motorway, rural road, cobblestones, dirt track, etc., a conclusion can be drawn about a permissible speed and / or a recommended speed (but also minimum speeds, for example, on motorways). Consequently, the confidence in the identified special situation can be further increased, and the occurrence of incorrect speed setting can be further reduced.

[0018] Preferably, the actual speed of the other road user is estimated using the sensor unit. Preferably, the speed control operation is maintained at the specified set speed in response to the estimated actual speed of the other road user exceeding a predetermined minimum speed, i.e., when the estimated actual speed of the other road user exceeds a predetermined minimum speed. The predetermined minimum speed is preferably chosen such that parked vehicles or slow road users such as cyclists, scooter riders, and the like are not included in the decision to maintain the set speed. This further increases the confidence in the determined special situation and further reduces the occurrence of incorrect use of the set speed.It is particularly preferred that the specified minimum speed is linked to the permitted speed. For example, the specified minimum speed in a 30 km / h zone is 15 km / h. With a permitted speed of 50 km / h, the specified minimum speed is preferably 20 km / h, while on a rural road with a permitted speed of 100 km / h, the specified minimum speed is, for example, 25 km / h. Preferably, the specified minimum speed on rural roads is not less than 30 km / h, as this is the maximum speed of agricultural vehicles such as tractors. On a motorway, a specified minimum speed is generally not necessary due to the minimum speed requirement.

[0019] Preferably, the other road user is detected in front of the vehicle using the sensor unit. Furthermore, the other road user is preferably detected laterally to or behind the vehicle using the sensor unit with a time delay. Preferably, the cruise control operation is maintained at the set speed in response to the detection of the other road user first in front of the vehicle and then laterally to or behind the vehicle with a time delay. This time-delayed detection of the other road user further increases the confidence in the identified special situation, particularly the overtaking request or maneuver. Accordingly, the occurrence of incorrect speed setting can be further reduced.For example, the overtaking maneuver is considered complete when the vehicle is still in the overtaking lane but is already traveling at least a predetermined distance ahead of the other road user. This predetermined distance is preferably time-dependent on the vehicle's current speed. For example, the distance is predetermined after a time of 0.1 seconds, preferably 0.3 seconds, and most preferably 0.5 seconds, from the time the vehicle overtook the other road user. With an exemplary speed difference of 36 km / h (corresponding to 10 m / s) between the vehicle and the other road user, the vehicle is one meter ahead after 0.1 seconds. Therefore, the overtaking maneuver would be considered complete when the vehicle is traveling one meter ahead of the other road user.

[0020] Furthermore, the sensor unit preferably determines whether the road class of the road being traveled is a motorway without a speed limit. Preferably, maintaining the speed control operation at the specified set speed also occurs in response to this determination. Determining a driver's intention to adjust the set speed on an unrestricted motorway can be difficult, as the driver may sometimes wish to maintain a higher speed for extended periods. Therefore, by excluding unrestricted motorways, the occurrence of incorrect speed setting adjustments can be further reduced.

[0021] In a further preferred embodiment, the vehicle's cruise control system includes adaptive cruise control. In a preferred step, the set speed of the cruise control system is compared with the actual speed of the vehicle. Preferably, the cruise control operation is maintained at the specified set speed in response to a difference between the set speed and the actual speed exceeding a predetermined limit. This predetermined limit is preferably at least 0.1 km / h, particularly 2 km / h, and most preferably 5 km / h.In other words, this scenario concerns a driving situation where another road user is traveling ahead of the vehicle at a speed slower than the vehicle's set speed, and the adaptive cruise control has reduced the vehicle's speed to maintain a constant distance to the other road user. If the driver presses the accelerator pedal in this situation, it can be assumed that the driver intends to overtake the other road user and then resume their (original) set speed. Therefore, in this case, the confidence level regarding the identified special situation is increased, particularly regarding the intention or execution of the overtaking maneuver. Consequently, the occurrence of incorrect set speed settings can be reduced.

[0022] Another aspect concerns a control unit for a motor vehicle, which is configured to carry out the aforementioned procedure. The motor vehicle is preferably designed as described above. The optional features and their advantages described in the procedure can be implemented analogously in the control unit and are therefore freely combinable.

[0023] The aforementioned control unit is preferably implemented using electrical or electronic components (hardware) or firmware (ASIC). Additionally or alternatively, the functionality of the control unit is realized when a suitable program (software) is executed. Equally preferred is the control unit implemented using a combination of hardware, firmware, and / or software. For example, individual components of the control unit for providing specific functionalities are designed as separate integrated circuits or arranged on a common integrated circuit.

[0024] The individual components of the control unit are preferably configured as one or more processes running on one or more processors in one or more electronic computing devices and generated during the execution of one or more computer programs. The computing devices are preferably configured to cooperate with other components, such as a sensor unit for scanning the vehicle's surroundings and a cruise control system, to implement the functionalities described herein. The instructions of the computer programs are preferably stored in a memory, such as a RAM element. However, the computer programs can also be stored in a non-volatile storage medium, such as a CD-ROM, flash memory, or the like.

[0025] It is also apparent to a person skilled in the art that the functionalities of several computing units (data processing devices) can be combined or combined in a single device, or that the functionality of a particular data processing device can be distributed across a large number of devices in order to realize the functionality of the control unit.

[0026] Another aspect concerns a computer program comprising commands which, when the program is executed by a computer, such as a control unit for a motor vehicle having a sensor unit for scanning a vehicle environment and a speed control system, cause it to carry out the method according to the invention, in particular a method for a motor vehicle.

[0027] Further preferred embodiments of the invention result from the other features mentioned in the dependent claims.

[0028] Unless otherwise stated in individual cases, the various embodiments of the invention mentioned in this application can be advantageously combined with one another.

[0029] The invention is explained below using exemplary embodiments with reference to the accompanying drawings. These show: Fig. 1 a schematic representation of a driving situation of a motor vehicle with a control unit according to an embodiment and Fig. 2 a schematic representation of a procedure according to a form of implementation.

[0030] Fig. Figure 1 shows a schematic representation of a driving situation of a motor vehicle 10 with a control unit 24 according to one embodiment. The motor vehicle 10 further comprises a sensor unit 12 for scanning the vehicle's surroundings and a cruise control system 14. The sensor unit 12 has a plurality of vehicle environment sensors for scanning the vehicle's surroundings. The plurality of vehicle environment sensors are designed as radar and / or lidar-based sensors. Additionally or alternatively, a surround-view camera system, for example a 360-degree (surround view) camera system, is preferably provided. The cruise control system 14 is a cruise control system, i.e., a speed control system that regulates the speed of the motor vehicle 10 to a predetermined set speed in cruise control mode. Alternatively, the cruise control system 14 is designed as an adaptive cruise control system.The adaptive cruise control system is designed to use sensor unit 12 to scan the area in front of the vehicle 10 for obstacles, such as another road user 18, and to issue a braking command to avoid a rear-end collision with a detected obstacle. The adaptive cruise control system thus maintains a (time-dependent) distance or a specific time to the other road user 18 ahead. The control unit 24 is connected to sensor unit 12 and the cruise control system 14.

[0031] The motor vehicle 10 further comprises an accelerator pedal 16 in the footwell of the driver's cab, which can be operated to accelerate the motor vehicle 10. The cruise control system 14 is configured such that, in cruise control mode, operation of the accelerator pedal 16 leads to an increase in the set speed of the cruise control system 14. In order to prevent the set speed from being unintentionally adjusted in a special situation by operation of the accelerator pedal 16, or from being unduly adjusted for the driver, special situations are detected using the sensor unit 12 and the control unit 24, and the predetermined set speed is maintained in any detected special situation.The special situations correspond to driving situations that require a brief deviation from the set speed of the cruise control system 14 to manage the driving situation without an accident and / or in which increasing the set speed would exceed a permissible speed or a recommended speed. This improves the operation of the cruise control system 14 and reduces the occurrence of operating errors. At least one example of a special situation is described below, although the invention is not limited to this exemplary special situation.

[0032] As in Fig. As shown in Figure 1, vehicle 10 and another road user 18, traveling in front of vehicle 10, are on a shared lane 20 of a rural road. The lane 22 adjacent to lane 20 is a lane for oncoming traffic. For example, assume that the speed of the other road user 18 is 90 km / h and the set speed of the cruise control system 14 of vehicle 10 is 100 km / h. Consequently, the speed of the other road user 18 is lower than the set speed of vehicle 10. To prevent a collision by vehicle 10, vehicle 10 must either be slowed down to at least 90 km / h (for example, by the adaptive cruise control) or the driver of vehicle 10 must overtake the other vehicle.The overtaking maneuver in this situation is an example of the special situation that can be captured by the invention.

[0033] According to the in Fig. In the exemplary driving situation shown in Figure 1, an overtaking maneuver (special situation) is carried out by vehicle 10 by pulling out into the adjacent lane 22. Since the speed difference of 10 km / h between the other road user 18 and vehicle 10 is too small to complete the overtaking maneuver quickly (due to the imminent danger from oncoming traffic in the adjacent lane 22), the driver will depress the accelerator pedal 16 of vehicle 10 to accelerate the vehicle. Furthermore, vehicle 10 steers into the adjacent lane 22, overtakes the slower-moving road user 18, and returns to its original lane 20. Consequently, the driver of vehicle 10 only briefly increased the speed of vehicle 10 for this special situation in order to resolve the driving situation without an accident.However, it cannot be assumed that the driver of vehicle 10 intends to continue driving at the speed briefly increased during the overtaking maneuver as their new set speed. For example, the increased speed during the overtaking maneuver exceeds the maximum permitted speed of 100 km / h on the rural road. Therefore, the driver eventually wants to return to their (originally) predetermined set speed of 100 km / h. Using sensor unit 12, it is determined that the overtaking maneuver just described has taken place. The completed overtaking maneuver is classified as a special situation, and in response to this special situation, the (originally) predetermined set speed is maintained.

[0034] The following describes further conditions under which a special situation can be identified. Firstly, a special situation can be identified if the sensor system 12 of the motor vehicle 10 detects that the other road user 18 is initially in front of the motor vehicle 10 and subsequently beside or behind it. This indicates that an overtaking maneuver constitutes a special situation.

[0035] Another way to identify a special situation is if the sensor unit 12 detects a lane change and a subsequent lane change back to the vehicle's original lane 20. This can also be used to conclude that an overtaking maneuver is a special situation.

[0036] Furthermore, a special situation can be determined by comparing the actual speed after an overtaking maneuver with the set speed of the vehicle 10. If the actual speed of the vehicle 10 after the overtaking maneuver is lower than the set speed increased by actuating the accelerator pedal 16, it can be assumed that the driver did not intend to increase the set speed.

[0037] In another embodiment, a special situation can be determined based on the following four conditions. First, the set speed minus the actual speed must initially be greater than a certain threshold, for example, 2 km / h. Second, the other road user 18 must be detected in front of the vehicle 10 and be present as a control object (for example, for ACC). The speed of the other road user 18 must not be much lower than the permitted maximum speed on the road in order to exclude parked objects and / or slower road users such as cyclists. Third, the road class must not be a motorway. As a fourth condition, the turn signal must have been activated and an overtaking maneuver must have started or be underway. If these four conditions (or any one of the previously mentioned conditions) are met, the set speed is not overridden by pressing the accelerator pedal 16.The setting speed, for example, remains at the original 100 km / h.

[0038] Fig. Figure 2 shows a schematic representation of a procedure for a motor vehicle 10 according to one implementation form. The motor vehicle 10 is the one in Fig. 1. Motor vehicle 10 shown. The motor vehicle 10 includes the above control unit 24, which is configured to carry out the procedure.

[0039] According to a first procedural step 50 of the procedure, the motor vehicle 10 is operated in speed control mode at a specific setting speed.

[0040] In a second process step 52, an actuation of the accelerator pedal 16 of the motor vehicle 10 is recorded.

[0041] In a third process step 54, a special situation of the motor vehicle 10 is determined using the sensor unit 12. The special situation corresponds to a driving situation that requires a brief deviation from the set speed of the cruise control system 14 in order to manage the driving situation without an accident and / or in which an increase in the set speed exceeds a permissible speed or a recommended speed.

[0042] In a fourth process step 56, the speed control operation is maintained with the determined set speed in response to the actuation of the accelerator pedal 16 of the motor vehicle 10 and the determination of a special situation. Reference symbol list 10 motor vehicle 12 Sensor unit for scanning a vehicle's surroundings 14 Cruise control system 16 Accelerator pedal 18 other road users 20 lanes 22 adjacent lane 24 Control unit 50 first procedural step 52 second procedural step 54 third procedural step 56 fourth procedural step

Claims

Method for a motor vehicle (10), wherein the motor vehicle (10) comprises a sensor unit (12) for scanning a vehicle environment and a cruise control system (14), and the method comprises the steps of: - operating (50) the motor vehicle (10) in cruise control mode at a specified set speed, - detecting (52) an actuation of the accelerator pedal (16) of the motor vehicle (10), - determining (54) a special situation of the motor vehicle (10) using the sensor unit (12) and based on a detected actuation of the turn signal of the motor vehicle (10), wherein the special situation comprises a lane change of the motor vehicle (10) and corresponds to a driving situation which requires a momentary deviation from the set speed of the cruise control system (14) to cope with the driving situation and / or in which an increase in the set speed exceeds a permissible speed or a recommended speed,and- maintaining (56) the cruise control operation with the specified set speed in response to the application of the accelerator pedal (16) of the motor vehicle (10) and the determination of a special situation. Method according to claim 1, wherein the method further comprises the step of: - determining the special situation of the motor vehicle (10) further based on the detected actuation of the accelerator pedal (16). Method according to claim 1 or 2, which further comprises the step of: - detecting a started or completed lane change from the originally driven lane (20) to an adjacent lane (22) using the sensor unit (12), - wherein the determination of the special situation of the motor vehicle (10) is further based on the detected started or completed lane change. Method according to claim 3, which further comprises the step of: - detecting a further lane change performed from the adjacent lane (22) back to the originally driven lane (20) using the sensor unit (12), - wherein the determination of the special situation of the motor vehicle (10) is further based on the detected further lane change. Method according to one of the preceding claims, which further comprises the step of: - detecting another road user (18) and / or a road class of the road traveled using the sensor unit (12), - wherein the determination of the special situation of the motor vehicle (10) is further based on the detected other road user (18) and / or the detected road class. Method according to claim 5, which further comprises the step: - estimating the actual speed of the other road user (18) using the sensor unit (12), - wherein maintaining the speed control operation with the determined set speed further occurs in response to exceeding a predetermined minimum speed by the estimated actual speed of the other road user (18). Method according to one of claims 5 or 6, which further comprises the steps: - detecting the other road user (18) in front of the motor vehicle (10) using the sensor unit (12) and - detecting the other road user (18) laterally to or behind the motor vehicle (10) using the sensor unit (12) with a time delay, - wherein the maintenance of the speed control operation with the specified set speed further occurs in response to a detection of the other road user (18) first in front of the motor vehicle (10) and then laterally to or behind the motor vehicle (10) with a time delay. Method according to one of claims 5 to 7, which further comprises the step of: - determining whether the road class of the road travelled is a motorway without a speed limit, using the sensor unit (12), - wherein the maintenance of the speed control operation with the determined set speed is further carried out in response to the determination of whether the road class of the road travelled is a motorway without a speed limit. A method according to one of the preceding claims, wherein the cruise control system (14) of the motor vehicle (10) comprises adaptive cruise control and the method further comprises the step of: - comparing an actual set speed of the cruise control system (14) with an actual speed of the motor vehicle (10), - wherein maintaining the cruise control operation at the specified set speed further occurs in response to exceeding a predetermined limit value by a difference between the actual set speed and the actual speed. Control unit (24) for a motor vehicle (10) which is configured to perform a method according to one of the preceding claims.

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