Method and distance adjuster for adjusting the distance between a vehicle and a vehicle traveling ahead

Abstract

The invention relates to a method for adjusting a distance (204) between a vehicle (200) and a vehicle (202) traveling ahead, characterized in that in a limiting step the distance (204) is limited to a preselected distance target value (118), and in an adjusting step the distance target value (118) is adjusted using a change in an accelerator pedal angle (120).

Description

Technical Field

[0001] The invention relates to a method for adjusting the distance between a vehicle and a vehicle traveling ahead and a distance adjuster for a vehicle. Background Art

[0002] The distance limiter for a vehicle keeps the distance between the vehicle and the vehicle ahead at a certain minimum distance by means of brake intervention and intervention in the acceleration request made to the accelerator pedal of the vehicle. If the limiter is switched on, acceleration requests that would be suitable for reducing the distance below the minimum distance are ignored. Summary of the invention

[0003] Against this background, a method for adjusting the distance between a vehicle and a vehicle traveling ahead and a distance adjuster as well as a corresponding computer program product are proposed with the aid of the solution proposed here. Advantageous developments and improvements of the solution proposed here are derived from the description and are described in the dependent claims.

[0004] Advantages of the present invention

[0005] Embodiments of the present invention can advantageously achieve: the distance to the vehicle traveling ahead is adapted to the situation without falling below the safety distance. Thus, when the vehicle traveling ahead brakes to turn, a natural driving feeling can be achieved and, for example, a swing of the vehicle can be obtained.

[0006] A method for regulating a distance between a vehicle and a vehicle traveling ahead is proposed, characterized in that in a limiting step the distance is limited to a preselected distance target value and in an adjusting step the distance target value is adjusted using information about a change in an accelerator pedal angle.

[0007] Furthermore, ideas regarding the embodiments of the present invention can be regarded as concepts and perceptions based on the following description.

[0008] The target distance value can be the distance between the vehicle and the vehicle traveling directly in front, which should not be lowered normally. The target distance value should be at least as large as the safety distance, so that in all traffic conditions, for example, when the vehicle traveling in front suddenly brakes, the safety of two vehicles traveling one after another will not be endangered. However, in order to, for example, improve the driver's sense of security, the target distance value can also be selected to be larger than the safety distance. It may be particularly advantageous that the distance target value can be adjusted individually to the driver's needs. The target distance value can be related to the speed of the vehicle. The target distance value can be larger at higher speeds than at lower speeds. The target distance value can be reduced to the speed-related safety distance at most. The safety distance can be predetermined, for example, by the reaction time of the emergency braking system of the vehicle or the driver.

[0009] In the case of conventional distance limiters, the distance target value is fixedly predefined, but the distance regulator proposed here should provide the following possibility: the distance target value can be dynamically adapted to the driver's wishes within certain limits. In the case of adjusting the distance regulator, information about the change of the accelerator pedal angle should be taken into account in particular. Here, the accelerator pedal angle indicates how far the accelerator pedal of the vehicle is pressed down by the driver from the static position. Therefore, the change of the accelerator pedal angle provides an indication about the driver's current acceleration expectation. If the driver increases the accelerator pedal angle, for example, this can be understood as the following instruction to the distance regulator: temporarily reduce the distance target value to be maintained, that is, approach the vehicle driving in front.

[0010] In the limiting step, if the distance is limited to the distance target value, for example, information about the change in the accelerator pedal angle can be only partially transmitted to the drive device. In particular, an increase in the accelerator pedal angle can be only partially transmitted to the drive device. A reduction in the accelerator pedal angle can be fully transmitted to the drive device.

[0011] The method may have a pre-adjustment step, in which the distance target value is pre-adjusted using a pre-set value for the distance target value read by an operating element of the vehicle. The distance target value may be pre-adjusted before the vehicle approaches a vehicle traveling ahead. The operating element may be, for example, a lever at a steering column or a steering wheel of a vehicle. The pre-set value may be understood as a reference value for the distance to be limited. Different pre-set values ​​may be set on the operating element, for example. Each pre-set value represents a different output distance target value. Starting from the output distance target value, the distance target value is then adjusted in the adjustment step using a change in the driver pedal angle.

[0012] The distance target value can be pre-set using a speed-independent time gap value as a pre-set value. The time gap value represents the time until the vehicle passes the same point as the vehicle traveling ahead. Thus, without changing the pre-set value, the distance to be maintained in practice becomes larger when the speed increases and smaller when the speed decreases.

[0013] If the gradient of the accelerator pedal angle is greater than a threshold value, the preset value can be changed by a predefined level (Stufe). If the accelerator pedal is pressed or released quickly, a high gradient of the accelerator pedal angle results. If the accelerator pedal is pressed quickly, a smaller preset value can be set than on the operating element. Here, the distance between the vehicles is quickly reduced without falling below the minimum safety distance at the driving speed. If the accelerator pedal is released quickly, a larger preset value is set than on the operating element. By releasing the accelerator pedal, the vehicle is decelerated and the distance is increased. The deceleration can be supported by weak braking intervention.

[0014] If the accelerator pedal angle is increased, the distance target value can be reduced. If the accelerator pedal is pressed at a low speed, the change in the accelerator pedal angle can be partially transmitted to the vehicle's drive. The vehicle then slowly approaches the vehicle in front and maintains the distance.

[0015] If the accelerator pedal angle is reduced, the distance target value can be increased. If the accelerator pedal is released at a low speed or the force on the accelerator pedal is slowly reduced, the change in the accelerator pedal angle can be partially transmitted to the drive of the vehicle. The vehicle then slowly reverses behind the vehicle traveling in front. Starting from the distance target value predefined by the predefined value, the distance can be kept constant again.

[0016] When using the current target distance value, an intervention limit for the control device of the vehicle can be predefined. The smaller the target distance value, the stronger the braking intervention and / or the change in the acceleration request can be. In other words, the vehicle can brake more strongly the closer it is to the vehicle traveling ahead.

[0017] The method can be implemented, for example, in software or hardware or in a hybrid form of software and hardware, for example in a control unit.

[0018] The solution proposed here also provides a distance adjuster which is designed to carry out, control or implement the steps of the variant of the method proposed here in a corresponding device.

[0019] The distance adjuster can be an electrical device having at least one computing unit for processing signals or data, at least one memory unit for storing signals or data, at least one interface for reading or outputting data and / or a communication interface, which is embedded in the communication protocol. The computing unit can be, for example, a signal processor, a so-called system ASIC or a microcontroller, so as to process the sensor signal according to the sensor signal and output the data signal. The memory unit can be, for example, a flash memory, an EPROM or a magnetic memory unit. The interface can be constructed as a sensor interface for reading the sensor signal of the sensor and / or as an actuator interface for outputting a data signal and / or a control signal to the actuator. The communication interface can be constructed for reading or outputting data wirelessly and / or wiredly. The interface can also be a software module, which, for example, coexists on a microcontroller with other software modules.

[0020] Also advantageous is a computer program product or a computer program having a program code, which can be stored on a machine-readable carrier or storage medium, such as a semiconductor memory, a hard disk memory or an optical memory and is used in particular to implement, realize and / or control the steps of a method according to one of the previously described embodiments when the program product is executed on a computer, a programmable control device or a similar device.

[0021] It is pointed out that some of the possible features and advantages of the present invention are described here with reference to different embodiments as a method and a distance adjuster for adjusting the distance. It is apparent to those skilled in the art that features can be combined, matched or exchanged in a suitable manner to realize other embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Embodiments of the present invention are described below with reference to the accompanying drawings, wherein neither the drawings nor the description should be designed to limit the present invention.

[0023] Figure 1 A block diagram showing a spacing adjustment system having a spacing adjuster according to one embodiment; and

[0024] Figure 2 A diagram of a vehicle having a space adjuster is shown according to one exemplary embodiment.

[0025] The drawings are only schematic and not to scale. The same reference numerals in the drawings denote the same or identically acting features. DETAILED DESCRIPTION

[0026] Figure 1A block diagram of a distance adjustment system 100 is shown. The distance adjustment system 100 has a distance adjuster 102 according to the scheme proposed here and has an acceleration adjuster 104. The distance adjustment system 100 is provided for a vehicle. Here, the vehicle is called the own vehicle (Egofahrzeug). The distance adjuster 102 is configured to perform a dynamic, driver-related desired distance calculation. For this purpose, a predetermined value 108 of the distance between the own vehicle and the vehicle traveling in front is read by an operating element 106 of the own vehicle. Here, the vehicle traveling in front is called a target vehicle. The actual current distance is measured by a distance sensor 110 of the own vehicle and described with a distance value 112. The distance adjuster 102 reads the distance value 112. Additional information can be obtained from the change process of the distance value 112. When using the speed of the own vehicle described by the speed value 114 and / or the acceleration of the own vehicle described by the acceleration value 116, the speed of the target vehicle and / or the acceleration of the target vehicle can be inferred from the change process.

[0027] The distance regulator 102 reads an accelerator pedal angle 120 of an accelerator pedal 122 of the host vehicle in order to determine a distance target value 118. The distance target value 118 is determined using the read value. The distance target value 118 is transmitted to the acceleration regulator 104. In a calculation device 124 of the acceleration regulator 104, an acceleration target value 126 is calculated using the distance target value 118 and the accelerator pedal angle 120. The acceleration target value 126 is read by a control device 128 of the acceleration regulator 104. In the control device 128, the acceleration target value 126 is converted into a drive control signal 130 for a drive device 132 of the vehicle and / or a brake signal 134 for a brake system 136 of the vehicle.

[0028] In addition, the control device 128 reads a deactivation signal 138 of a deactivation device 140 of the acceleration regulator 104. The deactivation device 140 monitors the accelerator pedal angle 120. When the accelerator pedal angle 120 at the accelerator pedal 122 changes at an angular velocity greater than a threshold value or the accelerator pedal angle exceeds a certain value, the deactivation device 140 outputs a deactivation signal 138. In response to the deactivation signal 138, the influence of the interval 112 is deactivated. If the driver performs a downshift, the driver, for example, overrides the accelerator pedal angle in order to achieve the greatest possible acceleration of the host vehicle. In this case, the driver takes over full control of the host vehicle.

[0029] In one embodiment, the distance controller of the operating element 106 also reads a maximum speed value 142. Using the maximum speed value 142 and the other variables read, a speed target value 144 is determined for the acceleration controller 104. In the calculation device 124, using the speed target value 144, an acceleration desired value 126 is calculated.

[0030] In one embodiment, actuator signal 146 for actuator 148 at accelerator pedal 122 is also output by actuation device 128. Actuator 148 acts in the opposite direction to the actuation direction of accelerator pedal 122. If actuation device 128 activates brake system 136 of the vehicle via brake signal 134, a haptic signal can be sent to the driver of the vehicle via actuator 148, for example.

[0031] Figure 2 According to one exemplary embodiment, a vehicle 200 is shown having a distance adjuster. In this case, the distance adjuster corresponds essentially to Figure 1 202. Here, vehicle 200 is marked as own vehicle 200 and is traveling behind a vehicle traveling in front, which is marked as target vehicle 202. In the above figure, own vehicle 200 is away from target vehicle 202 and is traveling at a higher speed than target vehicle 202. The speed of own vehicle 200 is determined by the current power output of the drive of own vehicle 200. The power requirement for the drive is predetermined by the driver of own vehicle 200 via the accelerator pedal angle 120 at the accelerator pedal 122 of own vehicle 200. Due to the differential speed, the distance 204 between vehicles 200 and 202 is reduced. The distance 204 is measured by at least one distance sensor of own vehicle 200 and adjusted by the distance adjuster. In order to prevent host vehicle 200 from exceeding speed-dependent distance target value 118 from target vehicle 202, distance controller reduces the power demand starting from speed-dependent damping distance 206 from target vehicle 202, independently of accelerator pedal angle 120, until distance 205 corresponds to distance target value 118 and both vehicles 200, 202 are traveling at the same speed. Host vehicle 200 is thus regulated to distance target value 118.

[0032] The driver of host vehicle 200 has set a preset value 108 for a distance target value 118 via operating element 106. Preset value 108 expresses distance target value 118 as a time gap between vehicles 200, 202. The time gap corresponds to the time period that elapses until host vehicle 200 passes a point that target vehicle 202 has previously passed. Since the host vehicle covers a larger section of road per time unit with increasing speed, distance target value 118 becomes larger as the speed increases, even though the preset time gap remains constant.

[0033] If the driver considers that the distance target value 118 is too great in the current traffic situation, he can shorten the distance 204 in the solution proposed here. To this end, the driver can further press the accelerator pedal 122 with the adjusted distance target value 118. The distance controller records the changed accelerator pedal angle 120 and adapts the distance target value 118, for example, proportionally to the change in the accelerator pedal angle 120, as long as the accelerator pedal 122 is pressed more strongly. In this case, the distance target value 118 is reduced to a minimum distance. If the driver reduces the pressure on the accelerator pedal 122, the distance controller also records the change in the accelerator pedal angle 120 and increases the distance target value 118 again, for example, proportionally to the change in the accelerator pedal angle 120, until the distance target value 118 originally set by the operating element 106 is reached again.

[0034] in other words, Figure 2 According to one exemplary embodiment, a vehicle 200 having a distance controller is shown. The distance controller is designed to predetermine a distance target value 118 for a distance 204 between vehicle 200 and a vehicle 202 traveling ahead as a function of an accelerator pedal angle 120 of an accelerator pedal 122 of vehicle 200 .

[0035] The distance controller of vehicle 200 adjusts the distance to distance target value 118 during braking intervention and / or power adaptation using the drive of vehicle 200 . To be able to adjust the distance, the distance controller reads a distance value representing distance 204 from a distance sensor of vehicle 200 .

[0036] The distance target value 118 is pre-set by the distance regulator in a value range. The unaffected distance target value 118 is in particular the highest value of the value range. The value range can be a speed-independent time interval range. Likewise, the value range can be speed-dependent. Then, the value range includes higher values ​​at higher speeds than at lower speeds.

[0037] The value range is set by the driver of vehicle 200 via operating element 106. Operating element 106 is designed, for example, as an operating lever on the steering wheel of vehicle 200. Operating element 106 can also be designed as a rotary switch or a menu of a vehicle control device.

[0038] If vehicle 200 approaches vehicle 202 traveling ahead, distance 204 decreases. If distance 204 approaches distance target value 118, distance controller reduces the power request assigned to current accelerator pedal angle 120 of accelerator pedal 122 by the power correction value in order to decelerate vehicle 200 until the speed of vehicle 200 and vehicle 202 traveling ahead almost match and distance 204 almost corresponds to distance target value 118. If the differential speed between vehicles 200, 202 is too great to be compensated by the power request, a braking request is output to the brake system of vehicle 200 by means of a brake intervention value.

[0039] If the driver considers that the adjusted distance 204 is too large or does not match the current traffic situation, the driver increases the accelerator pedal angle 120 of the accelerator pedal 122 or increases the pressure on the accelerator pedal 122. This change is recorded by the distance controller, and the distance target value 118 is reduced proportionally to the change in the value range. Due to the reduced distance target value 118, the increase in power demand accompanying the change is at least partially transmitted to the drive of the vehicle 200. The vehicle 200 shortens the distance 204 and approaches the vehicle 202 traveling in front until the new distance 204 corresponds to the distance target value 118 again.

[0040] In the case of a small increase in accelerator pedal angle 120, distance target value 118 is only slightly reduced. In the case of a large increase in accelerator pedal angle 120, distance target value 118 is greatly reduced. However, distance target value 118 remains within the selected value range. If the driver reduces accelerator pedal angle 120 again, i.e. applies less pressure on accelerator pedal 122, distance target value 118 is increased within the value range in proportion to the change in accelerator pedal angle 120.

[0041] In one embodiment, a switch is made to a narrower value range in response to an increase in the accelerator pedal angle 120. The narrower value range includes distance values ​​that are closer to the vehicle 202 traveling ahead. Thus, the maximum distance target value 118 of the narrower value range also indicates a smaller distance to the vehicle 202 traveling ahead than the maximum distance target value 118 of the other value range. Overall, the vehicle 200 travels closer to the vehicle 202 traveling ahead.

[0042] In order to maintain distance 204 corresponding to distance target value 118, the distance controller actuates a brake system of vehicle 200. The narrower the value range, the greater the possible braking intervention of the distance controller in order to brake vehicle 200 reliably without colliding with vehicle 202 traveling ahead.

[0043] The following diagram is shown: In this diagram, according to the approach proposed here, a distance 204 to a vehicle 202 traveling ahead is influenced. Vehicle 200 has a distance adjuster, such as in Figure 1 As shown in .

[0044] If distance 204 is greater than a maximum distance target value 118 defined by the preselected value range, vehicle 200 may travel faster than vehicle 202 traveling ahead and may approach vehicle 202 traveling ahead.

[0045] If vehicle 200 has already approached vehicle 202 traveling in front by a corresponding distance 204 corresponding to distance target value 118 and the driver does not press accelerator pedal 122 more strongly, the distance controller keeps distance 204 constant at a constant speed. If the speed decreases, vehicle 200 can approach even closer. If the speed increases, the distance controller increases distance 204.

[0046] If the driver considers adjusted distance 204 to be too great and appropriately increases the pressure on accelerator pedal 122 , the distance adjuster correspondingly reduces distance target value 118 within the value range.

[0047] In other words, a dynamic distance regulation or distance calculation (dynamic distance control / calculation) is provided.

[0048] Currently, there are different driver assistance systems in vehicles. Among others, cruise control (CrCtl), longitudinal limiter (LLim), ALLiM (Advanced LLim) and adaptive cruise control (ACC) increase the comfort and safety of the driver. In addition, further assistance systems provide safety benefits through distance warnings and emergency brake interventions.

[0049] In the solution proposed here, a dynamic desired distance is calculated. The minimum distance is calculated differently depending on different influencing variables. A minimum distance based on a time interval is used as a basis, similar to a distance-controlled cruise control. However, this minimum distance can be reduced when the current distance 204 approaches the minimum distance or when the minimum distance is reached, especially when the driver requests this.

[0050] If the driver is limited to a minimum distance with his vehicle to the vehicle ahead and wants to consciously approach further because the vehicle ahead is expected to turn (traffic flow requirements or for subjective reasons), the driver can reduce the minimum distance by increasing accelerator pedal angle 120. For example, the next smaller time gap or the minimum time gap can be selected.

[0051] The limiting function itself remains active, only the minimum distance and thus the released acceleration change. In order to keep the minimum distance within a safe range, it can only be reduced to a determined minimum minimum distance (last time gap) by slowly increasing accelerator pedal angle 120 .

[0052] For a further approach, similar to a downshift for deactivating the system, a high accelerator pedal gradient or a deflection of the accelerator pedal 122 is required.

[0053] In addition to taking into account variables such as accelerator pedal angle 120 , differential speed and distance to a minimum distance, geographical features such as slopes or curves may also be taken into account.

[0054] Likewise, an acceleration of vehicle 202 traveling ahead may result in different desired distances, since it makes sense to approach and follow accelerating vehicle 202 , whereas it makes sense to maintain a distance from braking vehicle 202 (subjective desired distance).

[0055] With regard to influencing factors, such as the acceleration of the target vehicle or the radius of the traveled route, a change possibility also results when the preselected distance target value is reduced. In one embodiment, with an identical increase in the accelerator pedal angle on a straight highway, the preselected distance target value decreases less than on a curved road or in a city.

[0056] Increased flexibility results. By using additional input variables in the calculation of the minimum distance, such as in particular accelerator pedal 122, the driver has the possibility, in addition to the safety and comfort of the distance limiter, to adapt distance 204 to his current, personal position, his requirements and the traffic situation. This can be achieved by taking into account the accelerator pedal behavior.

[0057] The proposed approach results in increased sportiness and safety. By taking into account the accelerator pedal position, the dynamic distance calculation provides the driver with the highest possible feedback. As with the currently known implementations of speed limiters, there is no significant dead band, since an increase in accelerator pedal angle 120 also results in vehicle acceleration. Although the vehicle acceleration is reduced in order to maintain safety and comfort, it nevertheless gives the driver the feeling that the vehicle behavior is always predetermined.

[0058] Furthermore, if the driver does not want a limitation, he can temporarily deactivate the function by a high accelerator pedal gradient or a high accelerator pedal value (conscious acceleration request).

[0059] This results in a behavior that is easy to understand for the driver, since the driver is always responsible for the acceleration and distance 204 (within certain limits) and can be adapted to the driver's driving style and driving situation. The driver obtains the reaction of the vehicle 200 by consciously changing the accelerator pedal 122. As a result, the necessity for interaction with the operating lever 106 is significantly reduced.

[0060] The approach proposed here can be implemented particularly easily by means of a software change of a motor control unit or a radar control unit in a vehicle in which a distance-controlled cruise control or a similar system is installed.

[0061] Finally, it should be pointed out that concepts such as "having", "comprising", etc. do not exclude other elements or steps, and concepts such as "a" and "an" do not exclude a plurality. Reference signs in the claims should not be considered as limitations.

Claims

1. A method for adjusting a distance (204) between a vehicle (200) and a vehicle (202) traveling ahead, characterized in that: In a limiting step, the distance (204) is limited to a preselected distance target value (118), and in a regulating step, the distance target value (118) is adjusted using information about a change in an accelerator pedal angle (120), wherein a changed accelerator pedal angle (120) is registered by a distance controller and the distance target value (118) is adapted proportionally to the change in the accelerator pedal angle (120), In which, starting from a speed-dependent damping distance (206) of the vehicle (202) traveling ahead, the power requirement of the drive of the vehicle (200) is reduced independently of the accelerator pedal angle (120) until the distance (204) between the vehicle (200) and the vehicle (202) traveling ahead corresponds to the distance target value (118) and the vehicle (200) and the vehicle (202) traveling ahead travel at the same speed, so that the vehicle (200) is adjusted to the distance target value (118).

2. The method according to claim 1 comprises a presetting step, in which the distance target value (118) is pre-set using a preset value (108) for the distance target value (118) read by an operating element (106) of the vehicle (200).

3. The method according to claim 2, wherein: In the step of presetting, the distance target value (118) is preset using a speed-independent time gap value as a preset value (108).

4. The method according to any one of claims 2 to 3, wherein: In the presetting step, if the gradient of the accelerator pedal angle (120) is greater than a threshold value, the predefined value (108) is changed by a predefined step.

5. A method according to any one of the preceding claims, wherein: In the adjusting step, if the accelerator pedal angle (120) is increased, the adjustment of the distance target value (118) is reduced.

6. A method according to any one of the preceding claims, wherein: In the adjusting step, if the accelerator pedal angle (120) is reduced, the adjustment of the distance target value (118) is increased.

7. A method according to any one of the preceding claims, wherein: In the regulating step, intervention limits of an actuation device (128) for the vehicle (200) are predefined using a current distance target value (118).

8. A method according to any one of the preceding claims, wherein: In the regulating step, the distance target value is adjusted using information about a differential speed between the vehicle and the vehicle travelling ahead and / or about an acceleration of the vehicle travelling ahead.

9. A method according to any one of the preceding claims, wherein: In the step of adjusting, the distance target value is adjusted using information about geographical features such as slopes, straight motorways, curved roads or in cities and / or information about the radius of curves, in particular the travelled route.

10. A distance adjuster (102) which is designed to carry out, implement and / or control the method according to one of the preceding claims in a corresponding device. 11 . A computer program product designed to carry out, implement and / or control the method according to claim 1 .

12. A machine-readable storage medium on which the computer program product according to claim 11 is stored.

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