METHOD FOR APPROACHING A VEHICLE TO A LOADING RAMP, CONTROL DEVICE AND VEHICLE

Description

[0001] The invention relates to a method for approaching a vehicle to a loading ramp, a control device for a vehicle for carrying out the method, and the vehicle with such a control device.

[0002] Loading ramps are typically found in depots, allowing vehicles, especially commercial vehicles, to approach them to within a few centimeters for loading or unloading. When manually maneuvering the vehicle into the loading or unloading position, the driver reverses until they feel a braking jolt due to the vehicle's rear contact with the loading ramp. The vehicle is then held in this position by manually operating the respective brake actuator.

[0003] In this case, manual approach to the loading ramp depends on the driver's experience, and excessive vehicle speed during rearward contact can lead to damage to the vehicle and / or the loading ramp. To mitigate this, loading ramps are known to absorb the energy of contact and transfer it into the ground to prevent more serious damage to both the vehicle and the building.

[0004] Furthermore, signals from a positioning system, such as GPS, can be used to assist in manual approach, enabling the vehicle's position and thus the distance between the vehicle and the loading ramp to be estimated. Signals from rear-mounted ultrasonic or radar sensors can also be used to estimate the distance to the loading ramp. DE 10 308 668 A1 describes, as an example, an assistance function for approaching a vehicle to a loading ramp using distance sensors, whereby the vehicle can be approached to within zero or just a few centimeters of the loading ramp.

[0005] A disadvantage of this approach is that determining the distance using the aforementioned distance sensors is usually very inaccurate when approaching the loading ramp with centimeter precision is required. Wheel speed sensors, such as those used in WO 03 051 697 A2 for approaching a loading ramp, are also very inaccurate at the low vehicle speeds typically used for approaching. Switching to more accurate 3D lidar sensors or rear-view cameras for distance measurement increases both the costs and the data processing effort within the vehicle.

[0006] Furthermore, during manual checks, the driver must apply the brakes at the right moment to prevent excessive backward roll after contact with the loading ramp. The manual approach process is therefore very time-consuming and inconvenient overall.

[0007] To simplify the approach process for the driver, assistance systems are known that partially automate the vehicle's movement, at least in the longitudinal direction. For example, approach buffers (bumpers) with integrated sensors are known from DE 20 2005 008 450 U1, GB 2 177 767 A1, E 2 929 983 A1 and DE 25 13 880 A1. These bumpers trigger a signal upon contact with an object, such as a loading ramp, causing the vehicle to brake while stationary. DE 10 2013 106 878 A1 describes the use of an additional contact sensor, alongside a distance sensor, to simplify the approach of a vehicle with a trailer to a loading ramp. The contact sensor is triggered mechanically.

[0008] Furthermore, EP 0 972 679 B1 describes an automated docking procedure for a towing vehicle with a trailer at a loading ramp, whereby specific speeds are set for reversing based on signals from distance sensors, and automated braking is initiated. It is also provided that slight contact between the trailer's approach bumpers and the loading ramp is permissible, and that the vehicle combination of towing vehicle and trailer is stopped upon detection of such contact.

[0009] In DE 103 45 748 A1 a method for detecting a vehicle docking to a docking device without additional sensors or switches is described.

[0010] Based on this, the object of the invention is to provide a method for approaching a vehicle to a loading ramp that is cost-effective, requires little effort, and is convenient to perform. A further object is to provide a control device and a vehicle.

[0011] This problem is solved by a method according to claim 1 and by a control device and a vehicle according to the independent claims.

[0012] According to the invention, a method is provided for approaching a vehicle to a loading ramp, for example, in a depot, container yard, loading point, or any other distribution center, wherein the vehicle preferably approaches the loading ramp in a reverse movement, wherein the vehicle has an acceleration sensor, the acceleration sensor being configured to detect the vehicle's acceleration, preferably in the longitudinal direction and optionally also in the lateral direction. Approaching or docking the vehicle to the loading ramp means that the vehicle moves towards the loading ramp until it makes contact and then continues to touch the loading ramp or remains within a few centimeters of it, so that loading or unloading can be carried out conveniently. At least the following steps are provided for this purpose: Limiting the vehicle's speed so that it does not exceed a defined approach speed when approaching the loading ramp. This applies to both manual and automated control of the vehicle's drive system and is intended to ensure that the vehicle does not approach the loading ramp too quickly, particularly in the final meters of the approach process. Preferably, manual control of the drive system via an accelerator pedal can also be prevented. Monitoring the vehicle acceleration measured by the acceleration sensor over time, especially during the speed limitation period. Thus, the vehicle acceleration is actively and continuously monitored during approach.Preferably, the vehicle speed can also be monitored after it has been limited to the approach speed using a speed sensor and / or a rotational speed sensor in a transmission of the vehicle's drive system. This allows for additional monitoring of the approach process, in particular adherence to the approach speed and / or the distance traveled until contact, which can be derived from the vehicle speed. An approach state is determined based on the time-monitored vehicle acceleration, with the approach state indicating whether or not contact has occurred between the vehicle and the loading ramp. Advantageously, the continuously monitored vehicle acceleration is used to determine whether or not contact with the loading ramp has taken place.This method exploits the fact that the vehicle changes its state of motion when it touches the loading ramp. This can be detected simply and reliably by observing a change in the vehicle's acceleration, so that monitoring the acceleration over time can indicate such contact with the loading ramp. Preferably, the determination of the approach state only takes place once the vehicle speed has been limited to the approach speed, thus minimizing data processing effort. Bringing the vehicle to a standstill and / or holding the vehicle in a standstill when contact with the loading ramp is detected, the vehicle preferably being braked to a standstill as a result of the contact. This advantageously ensures that the vehicle is immediately held or brought to a standstill after contact is detected, and this can be automated so that a reaction occurs immediately after contact and the subsequent standstill. Rolling back after contact is detected is therefore prevented or largely eliminated, so that the actual distance between the vehicle and the loading ramp is as small as possible, thus simplifying the loading or unloading process.

[0013] The process thus allows for the simple and reliable detection of contact with the loading ramp by utilizing an acceleration sensor in the vehicle, and the system then holds the vehicle, preferably already stationary, in that position. This makes the approach process very convenient for the driver. In a fully automated, driverless solution, the process is also safe and cost-effective, as no additional sensors are required in the vehicle. A precise acceleration sensor, which is already present in a vehicle equipped with, for example, an electronic stability control (ESC) system, can be used, thus keeping costs down.

[0014] Preferably, the system further provides for the determination or measurement of the actual distance between the vehicle and the loading ramp as the vehicle approaches. This preferably serves to limit the vehicle's speed as soon as the determined actual distance falls below a defined approach distance. This advantageously ensures that the vehicle only slows down significantly in the final meters before reaching the loading ramp, thus making the approach process more comfortable. The approach distance can be set, for example, to between 3.5 m and 4 m, or adjusted as needed.

[0015] Preferably, the actual distance between the vehicle and the loading ramp is determined using a position detection system and / or an environment detection system, which may include, for example, an ultrasonic sensor and / or a radar sensor and / or a LiDAR sensor and / or a camera. Accordingly, sensors already present in the vehicle can be used to at least roughly estimate the actual distance until the approach distance is reached and the controlled approach process according to the inventive method begins.

[0016] Preferably, within this controlled approach process, the determination of the approach state to ascertain whether or not contact has occurred between the vehicle and the loading ramp is not based on the measured actual distance between the vehicle and the loading ramp. Instead, a measurement parameter is used for the approach process that is easier and more accurately determined for the critical area shortly before reaching the loading ramp at low vehicle speed. The actual distance is therefore primarily used to find a suitable point in time for limiting the speed. However, according to the invention, the detection of contact is based on the time-monitored vehicle acceleration.

[0017] Preferably, it is further provided that contact between the vehicle and the loading ramp is determined as an approach state when it is established that The vehicle acceleration reaches or exceeds a specified acceleration limit and / or the vehicle jerk reaches or exceeds a specified jerk limit, the vehicle jerk being derived from the vehicle acceleration by temporal differentiation.

[0018] Therefore, according to the invention, monitoring vehicle acceleration over time can be understood as either directly tracking the vehicle acceleration over time or considering the temporal change in vehicle acceleration, which is characterized by the time derivative or vehicle jerk. From both quantities, by appropriately defining the respective threshold, it can be determined whether normal deceleration occurred as a result of a manual or automated braking request, or as a result of the vehicle contacting the loading ramp. Contact with the loading ramp typically leads to a more abrupt deceleration of the vehicle with a higher deceleration rate, which can be determined accordingly by monitoring the vehicle acceleration over time.

[0019] Preferably, it is further provided that the acceleration limit and / or the jerk limit and / or the approach speed and / or the approach distance and / or a motor torque set for the current approach process is or are adjusted based on approach information from at least one previous approach process. Therefore, for example, it can be determined on a ramp-specific basis how the approach process can be optimized by referring to past observations. If, for example, the loading ramp is cushioned, a different vehicle acceleration or jerk upon contact is to be expected. The limit values ​​must therefore be adjusted accordingly.The vehicle speed for approaching a loading ramp, as well as the torque setting, can vary depending on the ramp being approached and can therefore be adjusted based on previous approach information. The distance traveled, calculated from the measured vehicle speed, can also be used as approach information, for example, to determine the approach distance for a future approach.

[0020] Preferably, a self-learning algorithm is further provided for, which automatically adjusts the acceleration limit, the jerk limit, the approach speed, the approach distance, and / or the motor torque set for the current approach process based on approach information from at least one previous approach process. Advantageously, the algorithm learns with each approach process from information provided by sensors. This allows subsequent approach processes to be easily optimized with minimal effort. Only a suitably programmed self-learning algorithm needs to be provided, to which this past approach information is transmitted.

[0021] Preferably, it is further provided that the system also monitors whether the vehicle is stationary and determines the approach state based on whether the vehicle is stationary, whereby contact between the vehicle and the loading ramp is determined as an approach state when the vehicle is detected as stationary. In the simplest case, this allows the detection of contact to be validated based on the monitoring of vehicle acceleration over time. However, a detected stationary state can also be used even if no clear conclusions regarding contact between the vehicle and the loading ramp can be drawn from the monitored vehicle acceleration over time. Thus, the monitoring of vehicle acceleration over time is combined with the monitoring of stationary states.

[0022] Preferably, it can therefore be provided that, when the vehicle is detected as stationary, contact between the vehicle and the loading ramp is only determined as an approach state when The system also monitors vehicle acceleration over time, indicating contact between the vehicle and the loading ramp, and / or it detects that the vehicle speed remains unchanged despite an increase in engine torque following the detection of a standstill, even if the monitored acceleration does not indicate contact. This ensures that the vehicle is not, for example, "stuck" in a dip in the roadway, thus triggering the detection of a standstill. If the vehicle still does not move despite an increase in engine torque, it can be assumed with a high degree of certainty that, even without a corresponding indication from the vehicle acceleration over time, the loading ramp is already in contact and the vehicle is prevented from moving further.

[0023] Preferably, the vehicle is held stationary by the service brakes and / or parking brakes when contact with the loading ramp is detected. This allows the current distance to be maintained quickly and reliably after contact with the loading ramp is detected, enabling convenient loading or unloading. Preferably, the vehicle is initially held stationary by the service brakes, and the braking force is then transferred to the parking brakes. This allows the service brakes to quickly build up braking force, which can then be reliably maintained by the parking brakes after the ignition is switched off.

[0024] According to the invention, a control device for a vehicle for carrying out the method according to the invention is further provided, wherein the control device can be connected to an acceleration sensor in a signal-conducting manner and is designed to to limit the vehicle's speed in such a way that the vehicle does not exceed a specified approach speed when approaching a loading ramp; to monitor the vehicle acceleration measured by the acceleration sensor over time; to determine an approach state depending on the time-monitored vehicle acceleration, the approach state indicating whether or not contact has occurred between the vehicle and the loading ramp; and to bring the vehicle to a standstill and / or keep it stationary if contact between the vehicle and the loading ramp has been determined as the approach state.

[0025] Furthermore, according to the invention, a vehicle is provided with a braking system, a drive system, and a control unit according to the invention, wherein the vehicle has an acceleration sensor, for example, as part of an electronic stability control system. The acceleration sensor is configured to detect the vehicle's acceleration, preferably in a longitudinal direction and optionally also in a transverse direction with respect to the vehicle. The control unit is connected to the acceleration sensor via a signal conductor for transmitting the measured vehicle acceleration to the control unit. The control unit is further configured to… to control the drive system to limit the vehicle speed to the approach speed and to control the braking system to bring the vehicle to a standstill and / or to keep the vehicle stationary if contact of the vehicle with a loading ramp has been detected as the approach state.

[0026] The invention is explained in more detail below using an exemplary embodiment. The figures show: Fig. 1 a vehicle in a schematic view; Figs. 2, 3, 4 time profiles of a vehicle speed, a vehicle acceleration and a vehicle jerk; and Fig. 5 a flowchart of the method according to the invention.

[0027] In Figure 1The diagram schematically depicts a vehicle 1, which, for example, consists of a towing vehicle 2 and a trailer 3 (drawbar trailer). In principle, the procedure described below can be applied to any single-part or multi-part vehicle 1. For example, vehicle 1 is located in a depot 5, which has a loading ramp 7. Vehicle 1 is to be approached or docked to this ramp in reverse for loading or unloading.

[0028] Once it has been detected that the vehicle 1 is manually or (partially) automatically reversing towards the loading ramp 7, the method according to the invention, which is executed in a control unit 100 in the vehicle 1, can be started (ST0). The process sequence is illustrated by way of example in the flowchart in Fig. 5As shown: In a first step ST1, an actual distance D0 between a rear side 9 of the vehicle 1 (in the illustrated embodiment, the rear side of the trailer 3) and a docking surface 11 of the loading ramp 7, towards which the vehicle 1 is approaching, is estimated. The actual distance D0 can be estimated, for example, by means of an environmental sensing system 13, which is preferably arranged on the vehicle 1, i.e., on the towing vehicle 2 or on the trailer 3, and which is configured to monitor a rear area R behind the vehicle 1. The rear area R includes, in particular, the loading ramp 7, so that the environmental sensing system 13 is aligned accordingly.

[0029] The environmental sensing system 13 can, for example, include at least one ultrasonic sensor 13a and / or at least one radar sensor 13b and / or at least one LiDAR sensor 13c (e.g., also on the mirror of the vehicle 1) and / or at least one camera 13d, from which the actual distance D0 can be estimated as soon as the loading ramp 7 is within the detection ranges E (dashed line) of these sensors 13a, 13b, 13c, 13d. Additionally or alternatively, a position detection system 15 can be provided in the vehicle 1, which determines a position of the vehicle 1 relative to the loading ramp 7 based on signals from any global navigation satellite system (GNSS), e.g., GPS, GLONASS, etc., and from which the actual distance D0 can also be at least estimated, given the position of the loading ramp 7.

[0030] Therefore, for a rough distance determination, sensors already present in the vehicle 1 can be used, with the environment detection system 13 and the position detection system 15 being connected to the control unit 100 via corresponding signal transmission. In this step, the actual distance D0 is only roughly estimated in order to automatically determine an activation time for a subsequent speed limit. This prevents the vehicle 1 from having to travel an excessively long distance with a speed limit, thus preventing any impairment of driver comfort. However, this step ST1 can also be omitted, and the activation time can be determined automatically or manually in another way.

[0031] For speed limiting, a second step, ST2, checks whether the actual distance D0 determined in the first step, ST1, is less than a predefined approach distance D1. The approach distance D1 can be determined based on the accuracy of the environmental sensing system 13 or the position sensing system 15, which determine the actual distance D0. Alternatively, the approach distance D1 can also be set based on empirical values, for example, between 4.5 m and 3 m. Furthermore, an algorithm B can be provided on the control unit 100, which, for example, automatically adjusts the approach distance D1, as described later.

[0032] If the actual distance D0 reaches or falls below the approach distance D1, the vehicle speed V of vehicle 1 is limited to an approach speed V1 by the control unit 100 in a third step ST3 (speed limit). The approach speed V1 is, for example, less than 1 km / h, preferably less than 0.5 km / h, and particularly approximately 0.2 km / h. However, the approach speed V1 can also be adjusted, for example, by self-learning via the algorithm B provided on the control unit 100, as will be explained in more detail later.

[0033] Despite manual or automated control of the vehicle 1's drive system 17, a vehicle speed V greater than the set approach speed V1 cannot be achieved during reverse travel. Therefore, for actual distances D0 that are smaller than the approach distance D1, the vehicle 1 moves backward at a maximum speed of the approach speed V1. Additionally, the control unit 100 can deactivate the function of the vehicle 1's accelerator pedal as soon as the approach distance D1 is undershot.

[0034] The vehicle speed V can be monitored, for example, by active speed sensors 16 on the wheels 23, which are accurate even at low vehicle speeds V. Additionally or alternatively, rotational speed sensors 18a in a gearbox 18 of the drive train of the drive system 17 can be used, whereby the vehicle speed V can be determined from the rotational speed of the gearbox shafts, possibly taking the gear ratio into account.

[0035] In a fourth step, ST4, a vehicle acceleration A or a quantity characterizing it is continuously determined and monitored. The vehicle acceleration A is measured directly by at least one acceleration sensor 19 in the vehicle 1, wherein the acceleration sensor 19 is located in the towing vehicle 2 and / or in the trailer 3. The acceleration sensor 19 is configured to detect the vehicle acceleration A at least in the longitudinal direction X with respect to the vehicle 1 and, if necessary, also in the lateral direction Y.

[0036] This can be achieved using an acceleration sensor 19, which is already present in the vehicle 1 as part of an electronic stability control system 21 (ESC). The electronic stability control system 21 controls the stability of the vehicle 1 based on the measured acceleration A in the longitudinal and / or lateral directions X, Y, and possibly other parameters. Therefore, by using this existing sensor, the vehicle acceleration A can be determined with high precision even at low vehicle speeds V.

[0037] Preferably, the acceleration sensor 19 used in the invention is not a wheel speed sensor that measures the wheel rotational speeds of the wheels 23 of the vehicle 1, from which the vehicle acceleration A of the vehicle 1 can be indirectly derived by deriving this speed-dependent measurement. Due to their conventional operating principle with a pole wheel, wheel speed sensors cannot provide reliable results regarding the rotational behavior of the wheels 23 at the very low vehicle speeds V relevant for the approach according to the invention. The vehicle acceleration A determined from the wheel rotational speeds would therefore be inaccurate or would not reliably correspond to the actual vehicle acceleration A of the vehicle 1. A vehicle acceleration A determined in this way would therefore not necessarily make the approach of the vehicle 1 to the loading ramp 7 more precise and reliable.Therefore, for the method according to the invention, preferably an acceleration sensor 19 that directly measures the vehicle acceleration A is used.

[0038] As vehicle 1 approaches loading ramp 7, an approach state ZA is determined or checked in a fifth step ST5, depending on the vehicle acceleration A measured or monitored in the fourth step ST4. For this purpose, the vehicle acceleration A is monitored over time T, and it is determined whether the temporal behavior indicates an interaction or contact C between vehicle 1 and loading ramp 7. The temporal behavior of vehicle 1 is shown as an example in the following. Figures 2(Vehicle speed V), 3 (Vehicle acceleration A), 4 (Vehicle jerk J) are shown: At a first time point T1, after reaching the approach distance D1, the vehicle speed V is reduced due to the limitation of the vehicle speed V to the approach speed V1 in step ST3, whereby the approach speed V1 is reached or fallen below at a second time point T2. Accordingly, the acceleration sensor 19 measures a stage S in the vehicle acceleration A between the first and second time points T1, T2. After the second time point T2, the vehicle speed V initially remains approximately constant in the illustrated embodiment.

[0039] At a third point in time T3, vehicle 1 is "stopped" or prevented from moving further by loading ramp 7 during its reverse movement. This is reflected in the temporal behavior of the vehicle acceleration A according to Fig. 3This can be seen as a peak P. The vehicle's acceleration A therefore initially increases abruptly due to contact C with loading ramp 7 (deceleration to a standstill H) and then drops abruptly back to zero as soon as the vehicle 1 is at a standstill H. Thus, contact C with loading ramp 7 simultaneously decelerates the vehicle 1 to a standstill H.

[0040] To clearly detect such a contact C, in the fifth step ST5, it can be checked, for example, whether the magnitude of the vehicle acceleration A exceeds an acceleration limit value A1 and / or the magnitude of the vehicle jerk J exceeds a jerk limit value J1. As the Figure 3As can be seen, the vehicle acceleration A does not drop as sharply between times T1 and T2 as it does at time T3. Therefore, a deceleration of vehicle 1 resulting from an actively requested change in vehicle speed V is clearly distinguishable from an abrupt deceleration of vehicle 1 resulting from contact C with loading ramp 7. The vehicle jerk J at times T1 and T2 (actively requested deceleration) also differs from the vehicle jerk J at time T3 when contact C with loading ramp 7.

[0041] The limit values ​​A1 and J1 for vehicle acceleration A and vehicle jerk J, respectively, can be set in such a way that, when observing or analyzing the vehicle acceleration A over time, it can be determined as clearly as possible whether or not contact C with the loading ramp 7 has occurred. This is then output as the approach state ZA. Furthermore, the limit values ​​A1 and J1 for vehicle acceleration A and vehicle jerk J, respectively, can be automatically adjusted in algorithm B on the control unit 10, for example, based on observations or approach information I from one or more previous approach processes G, as will be explained in more detail below.

[0042] If the approach state ZA indicates that loading ramp 7 has been reached or contact C has occurred, in a sixth step ST6 a braking system 25 of the vehicle 1 is controlled such that the vehicle 1 is held stationary H, for example by automated actuation of the service brakes 25a and / or the parking brakes 25b of the vehicle 1, preferably in the towing vehicle 2 and in the trailer 3. A redistribution of braking force may also be provided, i.e., initially only the service brakes 25a are applied and the braking force is then transferred to the parking brakes 25b. This allows a braking force to be built up quickly and then transferred to the continuously acting parking brake 25b. At the same time, the engine torque M is reduced to zero by controlling the drive system 17.

[0043] If, in the fifth step ST5, neither the acceleration limit A1 nor the jerk limit J1 is reached or exceeded before the vehicle speed V is zero, the motor torque M implemented by the drive system 17 is increased in an intermediate step ST5.1, and the temporal behavior of the acceleration A and / or the vehicle speed V is subsequently monitored. In particular, it is checked whether the vehicle speed V increases again as a result of the increase in motor torque M and / or whether the acceleration limit A1 or the jerk limit J1 is subsequently reached or exceeded.

[0044] This intermediate step 5.1 serves to distinguish whether the vehicle 1 is "trapped" in a road depression or rut at the low approach speed V1 due to insufficient engine torque M, or whether the loading ramp 7 has already been reached without the respective limit values ​​A1, J1 being exceeded, for example due to unexpected cushioning at the loading ramp 7 or insufficient measurement resolution of the acceleration sensor 19 or the like.

[0045] These observations can be used as approach information I by the algorithm B installed on the control unit 100 to learn from previous approach processes G. The algorithm B can then automatically adjust the acceleration limit A1 and / or the jerk limit J1 and / or the motor torque M and / or the approach speed V1 for subsequent approach processes, for example, to prevent getting stuck in the recess or to obtain a measurable vehicle reaction upon contact C with the loading ramp 7. It can also take into account, for example, whether a peak P occurs after a successfully detected contact C with a specific vehicle acceleration A or corresponding vehicle jerk J, which can then be redefined as ramp-specific limit values ​​A1 and J1 for subsequent approach processes. This allows, for example, the following:A ramp-specific cushioning effect is taken into account in the event of contact C. The algorithm B thus learns from the available approach information I from previous approach processes G and can adjust the strategy accordingly for future approach processes.

[0046] In this way, the approach speed V1 can also be adjusted by the self-learning algorithm B installed on the control unit 100, based on observations or approach information I from one or more previous approach processes G. For example, if it was determined in one or more previous approach processes G that contact C with the loading ramp 7 at the set approach speed V1 leads to a very high vehicle acceleration A or a very high vehicle jerk J upon contact C (peak P), a corresponding ramp-specific reduction of the approach speed V1 can be implemented. This prevents damage to the loading ramp 7 building or to vehicle 1. Conversely, if the change in vehicle acceleration A upon contact C is too low, the approach speed V1 can be successively increased with each approach process.

[0047] The approach distance D1 can also be adjusted by algorithm B based on observations or approach information I from one or more previous approach processes G. For example, if it is determined that the actual distance D0 for a loading ramp 7 can be determined with increased certainty by the respective environmental sensing system 13 or position sensing system 15, and / or if the approach to the loading ramp 7 at the approach speed V1 has taken a very long time in several previous approach processes G, the approach distance D1 can be successively reduced further with each approach process under temporal observation. Information from other sensors in the vehicle 1 can also be used for this purpose.

[0048] In this way, algorithm B can learn through observation or by using existing approach information I to define and store different approach speeds V1 and / or approach distances D1 and / or acceleration limits A1 and / or jerk limits J1 specific to each ramp. Depending on the detected loading ramp 7, these can then be read by the control unit 100 during the next approach process. Reference symbol list (part of the description)

[0049] 1 Vehicle 2 Tractor 3 Trailer 5 Depot 7 Loading ramp 9 Rear of vehicle 1 11 Docking area of ​​loading ramp 7 13 Environmental sensing system 13a Ultrasonic sensor 13b Radar sensor 13c LiDAR sensor 13d Camera 15 Position sensing system 16 Speed ​​sensor 17 Drive system 18 Transmission 18a Speed ​​sensors 18a in the transmission 18 19 Acceleration sensor 21 Electronic stability control (ESC) 23 Wheels of vehicle 25 Braking system 25a Service brake 25b Parking brake 100 Control unit A Vehicle acceleration B Algorithm C Contact D0 Actual distance D1 Approach distance E Detection range G Previous approach H Stationary I Approach information M Engine torque PPeak R Rear distance S-level T-time T1-first time point T2-second time point T3-third time point V-vehicle speed V1-approach speed ZA-approach state ST1, ST2, ST3, ST4, ST5.1, ST6 Steps of the procedure

Claims

1. Method for having a vehicle (1) approach a loading ramp (7), wherein the vehicle (1) has an acceleration sensor (19), wherein the acceleration sensor (19) is designed to detect a vehicle acceleration (A) of the vehicle (1), comprising at least the following steps: - limiting a vehicle speed (V) of the vehicle (1) such that the vehicle (1) does not exceed a specified approach speed (V1) when approaching the loading ramp (7) (ST3); - monitoring, over time (T), the vehicle acceleration (A) measured by the acceleration sensor (19) (ST4); - determining an approach state (ZA) depending on the vehicle acceleration (A) monitored over time, wherein the approach state (ZA) indicates whether or not contact (C) has occurred between the vehicle (1) and the loading ramp (7) (ST5); and - bringing the vehicle (1) to a standstill (H) and / or holding the vehicle (1) at a standstill (H) if contact (C) of the vehicle (1) with the loading ramp (7) has been determined as the approach state (ZA) (ST6).

2. Method according to claim 1, characterized in that when the vehicle (1) approaches the loading ramp (7), an actual distance (D0) between the vehicle (1) and the loading ramp (7) is determined (ST1).

3. Method according to claim 2, characterized in that the vehicle speed (V) is limited (ST3) as soon as the determined actual distance (D0) falls below a specified approach distance (D1) (ST2) when the vehicle (1) approaches the loading ramp (7).

4. Method according to claim 2 or claim 3, characterized in that the actual distance (D0) between the vehicle (1) and the loading ramp (7) is determined using a position detection system (15) and / or an environment detection system (13), which has, for example, an ultrasonic sensor (13a) and / or a radar sensor (13b) and / or a LIDAR sensor (13c) and / or a camera (13d).

5. Method according to any of claims 2 to 4, characterized in that determining the approach state (ZA) to ascertain whether or not contact (C) has occurred between the vehicle (1) and the loading ramp (7) (ST5) does not depend on the determined actual distance (D0) between the vehicle (1) and the loading ramp (7).

6. Method according to any of the preceding claims, characterized in that contact (C) between the vehicle (1) and the loading ramp (7) is determined as an approach state (ZA) if it is ascertained that - the vehicle acceleration (A) reaches or exceeds a specified acceleration limit value (A1) and / or - a vehicle jolt (J) reaches or exceeds a specified jolt limit value (J1), the vehicle jolt (J) resulting from the vehicle acceleration (A) by temporal derivation.

7. Method according to claim 6, characterized in that the acceleration limit value (A1) and / or the jolt limit value (J1) and / or the approach speed (V1) is or are adjusted depending on approach information (I) from at least one previous approach process (G).

8. Method according to claim 7, characterized in that a self-learning algorithm (B), by self-learning, adapts the acceleration limit value (A1) and / or the jolt limit value (J1) and / or the approach speed (V1) depending on the approach information (I) from at least one previous approach process (G).

9. Method according to any of the preceding claims, characterized in that determining the approach state (ZA) (ST5) only occurs if the vehicle speed (V) has been limited to the approach speed (V1) (ST3).

10. Method according to any of the preceding claims, characterized in that it is further monitored whether the vehicle (1) is at a standstill (H), and the approach state (ZA) is determined depending on whether the vehicle (1) is at a standstill (H), contact (C) between the vehicle (1) and the loading ramp (7) being determined as an approach state (ZA) if a standstill (H) of the vehicle (1) is detected.

11. Method according to claim 10, characterized in that when a standstill (H) of the vehicle (1) is ascertained, contact (C) between the vehicle (1) and the loading ramp (7) is only determined as an approach state (ZA) if - the vehicle acceleration (A) monitored over time also indicates contact (C) between the vehicle (1) and the loading ramp (7) and / or - the vehicle speed (V) does not change despite an increase in engine torque (M) as a result of ascertaining a standstill (H).

12. Method according to any of the preceding claims, characterized in that the vehicle (1) is held at a standstill (H) by service brakes (25a) and / or parking brakes (25b) if contact (C) of the vehicle (1) with the loading ramp (7) has been determined as the approach state (ZA) (ST6).

13. Method according to claim 12, characterized in that the vehicle (1) is initially held at a standstill (H) by the service brakes (25a) and the braking force is then transferred to the parking brakes (25b).

14. Method according to any of the preceding claims, characterized in that the vehicle speed (V) is monitored, after the vehicle speed (V) has been limited to the approach speed (V1), via a speed sensor (16) and / or via a rotational speed sensor (18a) in a transmission (18) of a drive system (17) of the vehicle (1).

15. Control device (100) for a vehicle (1), for carrying out a method according to any of the preceding claims, wherein the control device (100) can be connected to an acceleration sensor (19) in a signal-conducting manner and is designed - to limit a vehicle speed (V) of the vehicle (1) such that the vehicle (1) does not exceed a specified approach speed (V1) when approaching a loading ramp (7); - to monitor, over time (T), a vehicle acceleration (A) measured by the acceleration sensor (19); - to determine an approach state (ZA) depending on the vehicle acceleration (A) monitored over time, wherein the approach state (ZA) indicates whether or not contact (C) has occurred between the vehicle (1) and the loading ramp (7); and - to bring the vehicle (1) to a standstill (H) and / or to hold it at a standstill (H) if contact (C) of the vehicle (1) with the loading ramp (7) has been determined as the approach state (ZA).

16. Vehicle (1) comprising a braking system (25), a drive system (17) and a control device (100) according to claim 15, wherein the vehicle (1) has an acceleration sensor (19), wherein the acceleration sensor (19) is designed to detect a vehicle acceleration (A) of the vehicle (1), wherein the control device (100) is connected to the acceleration sensor (19) in a signal-conducting manner for transmitting the measured vehicle acceleration (A) to the control device (100), and the control device (100) is further designed - to control the drive system (17) to limit the vehicle speed (V) to the approach speed (V1) and - to control the braking system (25) to bring the vehicle (1) to a standstill (H) and / or to hold the vehicle (1) at a standstill (H) if contact (C) of the vehicle (1) with a loading ramp (7) has been determined as the approach state (ZA).