Method and controller for operating a distance adjustment device controlled by an accelerator pedal

Abstract

The invention relates to a method for operating an accelerator-pedal-controlled distance adjustment device of a vehicle (100), wherein the distance adjustment device adjusts a distance (110) relative to a target vehicle (112) as a function of an accelerator pedal value (122) of the vehicle (100) and, if necessary, initiates an automatic braking process (202), wherein the braking process (202) is interrupted if the accelerator pedal value (122) increases during the braking process (202). The invention also relates to a controller and a machine-readable storage medium.

Description

Technical Field

[0001] The present invention relates to a method for operating an accelerator-pedal-controlled distance adjustment device of a vehicle and to a driver assistance system implemented in a control unit and having such a distance adjustment device. Background Art

[0002] In vehicles equipped with a distance control system, a situation-dependent desired distance to the vehicle ahead is adjusted. When approaching the vehicle ahead, the distance control system reduces the vehicle's engine power relative to the driver's input using the accelerator pedal until the vehicle is traveling behind the preceding vehicle at the desired speed within the desired distance. The distance control system can be deactivated, for example, by a kickdown of the accelerator pedal, for example, to overtake the preceding vehicle. Summary of the Invention

[0003] Against this background, the invention presented here provides a method for operating an accelerator-controlled distance adjustment device of a vehicle, a corresponding control unit, and finally a corresponding computer program product and a machine-readable storage medium. Advantageous embodiments and improvements of the invention are derived from the preferred embodiments.

[0004] Embodiments of the present invention advantageously enable a braking process behind a target vehicle that was mistakenly identified as a relevant preceding vehicle to be interrupted in order to subsequently pass the target vehicle.

[0005] The scope of the present application and the described invention relates to a distance adjustment device, particularly for inputting a driver command requesting acceleration or controlled by an accelerator pedal. In the case of a two-lane vehicle, this device for inputting a driver command can be an accelerator pedal, which is operated by the driver's foot. Alternatively, variations of this input device that perform the same function as the accelerator pedal are also possible. These include, for example, devices for manual throttle control, such as those offered as optional accessories by most automobile manufacturers, or throttle torsion bars or speed knobs, such as those used in single-lane vehicles like scooters and motorcycles, or in motorized trikes or quads. Such alternatives are obvious, and those skilled in the art will readily recognize these commercially established alternatives without inventive step. Furthermore, within the scope of the present application, for reasons of greater comprehensibility and readability, only the term accelerator pedal or a distance adjustment device controlled by the accelerator pedal is used; however, this also includes all other alternatives readily conceivable to a person skilled in the art, such as distance adjustment devices that are controlled by a throttle hand lever or a manual rotary knob or a speed rotary knob.

[0006] A method for operating an accelerator-pedal-controlled distance control device of a vehicle is proposed, wherein the distance control device adjusts the distance to a target vehicle as a function of an accelerator pedal value of an accelerator pedal of the vehicle and, if necessary, initiates an automatic braking process, wherein the braking process is interrupted if the accelerator pedal value increases during the braking process.

[0007] The conception of the embodiments of the present invention can be considered to be based on the concepts and knowledge described below.

[0008] In a distance control device of a vehicle's driver assistance system, a measured distance to a preceding target vehicle can be compared with a setpoint distance value. If the distance is greater than the setpoint distance value, the vehicle's drivetrain power target value can be increased. Conversely, if the distance is less than the setpoint distance value, the drivetrain power target value can be reduced. When the drivetrain power target value is approximately zero and the distance is less than the setpoint distance value, the distance control device can control the vehicle's brake system using a setpoint braking torque value to trigger a braking process.

[0009] Here, the distance is sensed by a sensor system of the vehicle. The distance can be sensed by one or more sensors of the sensor system. The sensor system can include, for example, at least one radar sensor, a lidar sensor, and / or a camera.

[0010] In conventional distance control devices, the desired distance value is speed-dependent and can be preselected by the driver of the vehicle, for example, via an operating element, depending on how closely the vehicle is to approach the target vehicle. The speed-dependent desired distance value can be defined as a time slot, since the distance covered within the duration of a time slot increases with increasing speed, and vice versa.

[0011] In accelerator-controlled distance adjustment devices, the desired distance value is also speed-dependent and influenced by the accelerator pedal value measured at the vehicle's accelerator pedal. The accelerator pedal value is correlated with the accelerator pedal angle. For example, the accelerator pedal value can be a percentage of the angle. The more forcefully the driver presses the accelerator pedal, i.e., as the accelerator pedal value increases, the desired distance value decreases. The desired distance value is never less than a speed-dependent safety value.

[0012] If the target vehicle brakes in front of this vehicle, the distance quickly becomes smaller and therefore the drive setpoint value also drops quickly until it is essentially 0. Subsequently, the braking system is also activated because reducing the drive setpoint value is not enough to make the distance approximately consistent with the distance setpoint value.

[0013] If the target vehicle, for example, changes onto a speed bump at a highway exit, thereby releasing the right-hand, one-way lane of the highway for the vehicle, the target vehicle may continue to be detected by the sensor system. The still detected vehicle may erroneously continue to be interpreted as the target vehicle of the distance adjustment device. This state may be referred to as a side lane interference ( NSS). That is, a change to a speed bump could be mistakenly interpreted as a turn by the target vehicle on the same unidirectional lane. If the sensed vehicle now brakes on the speed bump, the distance adjustment device will also initiate a braking process.

[0014] However, the driver of the vehicle recognizes that the right-hand unidirectional lane is now free and wants to accelerate. To do this, the driver will further press his accelerator pedal and increase the accelerator pedal value in order to override the braking process. In the present invention, this increase in the accelerator pedal value is recorded and the braking process is interrupted.

[0015] In particular, the present invention also detects increases in the accelerator pedal value with small gradients. As a result, no forceful resistance or forced downshifting (kick-down) is required to interrupt the braking process. This can avoid potentially excessive, undesirable acceleration.

[0016] In general, the present invention allows for a simple solution to adjacent lane interferences. It functions independently of whether traffic rules require driving on the right or the left. As another example, overtaking can be accelerated by interrupting the braking process when the target vehicle changes from its own unidirectional lane to an adjacent unidirectional lane. Similarly, the present invention allows for ignoring vehicles detected in the adjacent lane during a turn and allowing the turn to continue virtually uninterrupted.

[0017] If the accelerator pedal value increases by a speed-dependent amount, the braking process can be interrupted. This amount can be proportional to the vehicle speed. Due to the dependence of the interruption criterion on speed, the braking process can be interrupted more easily at low speeds than at high speeds.

[0018] Furthermore, if the accelerator pedal value increases during the braking process following the initial decrease in the accelerator pedal value, the braking process can be interrupted. The target vehicle may have already braked while it is still at least partially traveling along its unidirectional lane. The driver can react to this and intuitively reduce the accelerator pedal value. When the driver recognizes that there is sufficient space to pass the target vehicle, they can increase the accelerator pedal value again.

[0019] The braking torque setpoint value of the braking system can be reduced using a reduction profile when the braking process is interrupted. This reduction profile allows for a smooth reduction of the braking torque to avoid jerkiness. The reduction profile can, for example, be a ramp or a curve. This reduction profile allows for better control of the vehicle's driving behavior when the braking process is interrupted.

[0020] The accelerator pedal value before the braking process can be stored as a reference value. The braking process can be interrupted when the accelerator pedal value increases above the reference value. Alternatively, the braking process can be interrupted when the accelerator pedal value increases above the reference value by more than a certain amount.

[0021] In addition, if a target vehicle in the adjacent lane is identified, the braking process can be interrupted. If a misinterpreted situation, ie, an adjacent lane interference, is identified by the driver assistance system, normal driving operation can be quickly resumed.

[0022] Before a braking process, the power target value of the vehicle's drive train can be recorded. The power target value can be increased to the recorded value after the braking process is interrupted. This value can also be recorded before the automatic reduction of the target value that occurs before the braking process. This allows for smooth driving and prevents excessive acceleration.

[0023] The method can be implemented, for example, in software or hardware, or in a hybrid form combining software and hardware, for example in a control unit.

[0024] Furthermore, the present invention provides a driver assistance system which is designed to carry out, control or implement the steps of the method variant proposed here in a corresponding device.

[0025] A driver assistance system can be an electrical appliance comprising: at least one computing unit for processing signals or data; at least one memory unit for storing signals or data; and at least one interface and / or communication interface for reading in or outputting data embedded in a communication protocol. The computing unit can be, for example, a signal processor, a so-called system ASIC, or a microcontroller for processing sensor signals and outputting data signals based on them. The memory unit can be, for example, a flash memory, an EPROM, or a magnetic memory unit. The interface can be designed as a sensor interface for reading in sensor signals from a sensor and / or as an actuator interface for outputting data signals and / or control signals to an actuator. The communication interface can be designed for reading in or outputting data wirelessly and / or wiredly. The interface can also be a software module, for example, located on a microcontroller alongside other software modules.

[0026] A computer program product or a computer program with a program code is also advantageous, which can be stored on a machine-readable carrier or storage medium, such as a semiconductor memory, hard disk memory or optical memory, and is used to implement, realize and / or control the steps of the method described in any of the above-described embodiments, in particular when the program product or program is executed on a computer or device.

[0027] It should be noted that some of the possible features and advantages of the present invention are described here with reference to different embodiments. A person skilled in the art will appreciate that the features of the driver assistance system and the method can be combined, adapted or exchanged in a suitable manner to obtain further embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In the following, embodiments of the present invention are described with reference to the drawings, wherein neither the drawings nor the description should be interpreted as limiting the present invention.

[0029] Figure 1 A diagram showing a vehicle having a driver assistance system according to one embodiment; and

[0030] Figure 2 A diagram shows various vehicle parameters during the implementation of a method according to one exemplary embodiment.

[0031] The drawings are only schematic and not true to scale. Identical reference numerals in the figures denote identical or identically acting features. DETAILED DESCRIPTION

[0032] Figure 1 According to one exemplary embodiment, a diagram shows a vehicle 100 having a driver assistance system 102 implemented in a controller 101. Vehicle 100 has a sensor system 104 connected to controller 101. Sensor system 104 senses at least one sensing area 106 arranged in front of vehicle 100 in the direction of travel via at least one sensor.

[0033] Vehicle 100 is traveling in the left lane of a two-lane road, such as a city ring road or a main highway. Another vehicle 108 is traveling ahead of vehicle 100 in the right lane of the road. Other vehicle 108 is at least partially within sensing area 106 and is detected by sensor system 104. Other vehicle 108 is traveling at a slower speed than vehicle 100. Vehicle 100 is approaching other vehicle 108 from behind, and a distance 110 between vehicles 100, 108 is decreasing.

[0034] Driver assistance system 102 incorrectly classifies another vehicle 108 as a target vehicle 112 for a distance control device of driver assistance system 102 . This state can be referred to as a lane interference. Due to this lane interference, the distance control device intervenes in the drive control of vehicle 100 before a target distance 114 is reached and reduces a target power value 116 of a drive train 118 of vehicle 100 until vehicle 100 is traveling behind target vehicle 112 at the speed of target vehicle 112 at a target distance 114, even though the lane in front of vehicle 100 is clear.

[0035] The distance adjustment device is an accelerator-controlled distance adjustment device. While the distance adjustment device is adjusting distance 110, the driver of vehicle 100 maintains their right foot on the vehicle's accelerator pedal 120. The driver notices a decrease in target power value 116 and intuitively increases accelerator pedal value 122 on accelerator pedal 120. Due to the increase in accelerator pedal value 122, the distance adjustment device reduces target distance 114 to a reduced target distance 124 and adjusts distance 110 accordingly. Vehicle 100 then moves closer to target vehicle 112. Reduced target distance 124 cannot be reduced arbitrarily. A speed-dependent minimum distance 126 is maintained by the distance adjustment device.

[0036] If distance 110 changes rapidly, for example because target vehicle 112 reduces its speed and / or brakes to turn, reducing target power value 116 may not be sufficient, and the distance control device intervenes in the brake control of vehicle 100 to control the braking process of vehicle 100. To this end, controller 101 may output target braking torque value 128 for braking system 130 of vehicle 100, for example.

[0037] Because the lane ahead of vehicle 100 is clear, the driver increases accelerator pedal value 122 when the braking process begins. In other words, the driver attempts to compensate for the effects of the braking process by increasing accelerator pedal value 122. However, the driver does not immediately fully depress accelerator pedal 120 in order to override the range control by means of a kickdown. Instead, the driver presses accelerator pedal 120 at a low speed, i.e., gently.

[0038] In the present invention, if accelerator pedal value 122 increases during the braking process, the braking process is interrupted. Vehicle 100 can now pass by the incorrectly identified target vehicle 112. Due to this passing, other vehicle 108 disappears from sensing area 106 and can therefore no longer be classified as a target vehicle.

[0039] In one embodiment, the braking process is interrupted in a controlled manner. In this case, the applied braking torque is not released suddenly. Instead, the braking torque is reduced by using a reduction profile. The reduction profile can be, for example, a ramp or a curve.

[0040] In one embodiment, the resultant acceleration is constructed based on the increased accelerator pedal value using an acceleration curve.

[0041] In an alternative example situation, another vehicle 108 initially travels ahead of vehicle 100 in the same lane and is correctly classified by driver assistance system 102 as target vehicle 112. Target vehicle 112 then changes to an adjacent lane. This lane could be, for example, a deceleration lane before an exit. For some reason, driver assistance system 102 fails to detect this lane change and continues to classify other vehicle 108 as target vehicle 112. If the driver accelerates during the automatically initiated braking process, the distance control device interrupts the braking process, even though other vehicle 108 continues to be incorrectly classified as target vehicle 112.

[0042] Even if the driver reduces accelerator pedal value 122 at the beginning of the braking process because, for example, target vehicle 112 still partially occupies the lane and only increases accelerator pedal value 122 when the lane is free, the braking process is interrupted.

[0043] In one embodiment, if the driver assistance system detects that a safety distance 132 has been exceeded during an interrupted braking process, the emergency brake assist device of driver assistance system 102 actuates braking system 130 for emergency braking. Safety distance 132 is less than minimum distance 126. For example, if another vehicle 108 does not leave sensing area 106 during the interrupted braking process, i.e., the vehicle's lane is not yet clear, then safety distance 132 may be exceeded.

[0044] Figure 2 A diagram showing different vehicle parameters during implementation of a method according to an embodiment. The vehicle parameters are recorded as follows Figure 1 The time course of the vehicle parameters during a lane disturbance is shown in FIG. The vehicle parameters are here vehicle speed 200 , distance 110 , and accelerator pedal value 122 . The course of the vehicle parameters is shown one above the other in a temporal relationship.

[0045] At the beginning of the curve, the accelerator pedal is depressed to approximately 20 percent and the vehicle is traveling at 50 kilometers per hour. At time t1, the target vehicle is detected and the distance adjustment device intervenes in the vehicle's drive control to position the vehicle at a desired distance 114 relative to the target vehicle.

[0046] However, the driver wants a smaller distance 110 relative to the target vehicle and presses the accelerator pedal to approximately 40 percent. As a result, the vehicle is briefly accelerated and is adjusted to a reduced desired distance 124 by the distance adjustment device.

[0047] For example, a target vehicle turns right and brakes. This target vehicle continues to be identified as a relevant target vehicle, even though it has released the lane for the vehicle in question. Because the target vehicle brakes, distance 110 decreases so rapidly that the driver assistance system initiates braking process 202 at time t2. Due to braking process 202, vehicle speed 200 decreases. Shortly after the start of braking process 202, the driver reacts by controlling an increase in accelerator pedal value 122 to counteract the braking process.

[0048] The driver assistance system detects a conflict between automated braking process 202 and increased accelerator pedal value 122 and interrupts braking process 202. After the interruption, vehicle speed 200 increases again.

[0049] In one embodiment, if the accelerator pedal value 122 increases by a predetermined amount 204 relative to before the braking process 202 , the braking process 202 is interrupted.

[0050] In one embodiment, after the interruption, vehicle speed 200 increases independently of accelerator pedal value 122 to the value before braking process 202 .

[0051] In other words, in Figure 1 and 2 In the embodiment of the present invention, the deceleration request / braking request for the driver assistance function that limits the driver's intention is withdrawn based on the accelerator pedal.

[0052] Driver assistance systems can provide drivers with increased comfort and safety, such as Adaptive Cruise Control (ACC) and Highway Assist (HWA). Furthermore, other assistance systems offer safety advantages through distance warnings and emergency braking interventions. The present invention improves the driver-oriented assistance function "Dynamic Distance Assist (DDA)," which primarily offloads pedal braking to a significant extent to the driver, while handing over the accelerator to the driver.

[0053] In the case of a lane violation with Adaptive Cruise Control (ACC), an object is mistakenly identified as a target, even though it is located in one of the adjacent lanes. In this situation, the vehicle may brake unintentionally. However, the driver has the option of simply compensating for this by taking over control by actuating the accelerator pedal. In this case, the ACC function enters a passive or override state, as the detected accelerator pedal actuation represents a request for a higher level of deceleration than the function intended.

[0054] Lane violations can also occur with driver-focused functions such as Dynamic Distance Assist (DDA). However, lane violations with these driver-focused functions appear different to the driver than with Adaptive Cruise Control (ACC). While the driver can easily override lane violations with Adaptive Cruise Control, this is somewhat more difficult with Dynamic Distance Assist because this function restricts the driver's control.

[0055] The time gap can be reduced by a margin via the accelerator pedal. If this margin is first consumed to a minimum once, a change to the override state is now only possible with a high accelerator pedal value or with a kickdown or accelerator pedal gradient.

[0056] The present invention offers the driver the possibility of controlling the driving behavior in a controlled manner by means of an increased accelerator pedal value and of reversing the deceleration in a controlled manner, especially in urban situations, in the event of undesired deceleration, for example in the case of an adjacent lane disturbance, even in the case of functions that restrict the driver's wishes, such as Dynamic Distance Assist (DDA).

[0057] The availability of the DDA function during acceleration or following a vehicle at higher speeds does not significantly decrease at high accelerator pedal values. During highway driving, the function remains active and provides protection even at higher speeds. The DDA function only enters the override state at very high accelerator pedal values.

[0058] In city driving, lane-side interference can lead to unpleasantly long and strong decelerations, because the driver's natural reaction to an undesired deceleration is not to use a very high accelerator pedal value or accelerator pedal gradient.

[0059] In this case, during deceleration, the accelerator pedal value can be stored and, depending on the positive increment relative to this accelerator pedal value, the brake can be released slowly and controllably, even beyond the possibility of a reduction in distance, and an undesirably strong deceleration can be avoided.

[0060] If the driver's first reaction to an undesired or unexpected deceleration is to release the accelerator pedal, this reference value can also be fed back.

[0061] For example, the driver can be informed via a display device of the vehicle that, in the case of deceleration, the brake will be released more quickly or a passive state will be assumed when the accelerator pedal value is increased.

[0062] Finally, it should be pointed out that concepts such as “having”, “including”, etc. do not exclude other elements or steps, and concepts such as “a” and “an” do not exclude a plurality.

Claims

1. A method for operating a distance adjustment device of a vehicle (100), the distance adjustment device being controlled by an operating element operable by a driver, wherein: The distance adjustment device adjusts the distance (110) relative to the target vehicle (112) according to a predetermined value of an operating element operable by a driver of the vehicle (100) and controls an automatic braking process (202) when necessary, wherein the braking process (202) is interrupted if the predetermined value of the operating element operable by the driver increases during the braking process (202), and wherein the braking process (202) is interrupted if the predetermined value of the operating element operable by the driver is increased by a speed-dependent value (204).

2. The method according to claim 1, wherein the braking process (202) is further interrupted if the predefined value of the driver-operable operating element increases again during the braking process (202) following the initial reduction of the accelerator pedal value.

3. The method according to claim 1 or 2, wherein, when the braking process (202) is interrupted, the braking torque setpoint value (128) is reduced by using a reduction profile.

4. The method according to claim 1 or 2, wherein an accelerator pedal value before the braking process (202) is stored as a reference value, wherein: If the predefined value of the driver-operable operating element increases above the reference value, the braking process (202) is interrupted.

5. The method according to claim 1 or 2, wherein the method further comprises interrupting the braking process (202) if the target vehicle (112) is detected in an adjacent lane.

6. The method according to claim 1 or 2, wherein the value of the power setpoint value (116) of the drive train (118) of the vehicle (100) is recorded before the braking process (202), wherein: After the braking process (202) is interrupted, the power setpoint value (116) is increased to the recorded value. 7 . The method according to claim 1 , wherein the predefined value of the driver-operable operating element is an accelerator pedal value, a throttle lever value, or a speed knob value.

8. A control unit (101) having a driver assistance system (102) implemented therein, the driver assistance system being designed to carry out, implement and / or control the method according to any one of claims 1 to 7 in a corresponding device. 9 . A computer program product, which is configured to carry out, implement and / or control the method according to claim 1 .

10. A machine-readable storage medium on which the computer program product according to claim 9 is stored.

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