Method and device for the assisted or automatic coupling of a trailer to a towing vehicle, as well as towing vehicle, electronic processing unit and computer program

Description

[0001] The invention relates to the technical field of commercial vehicles, in particular towing vehicles and trailers. Such trailers are often parked in depots of logistics companies and other businesses. The trailers often have to be maneuvered in the depot for loading, unloading, filling, maintenance, parking, etc. Finally, the trailers are picked up by towing vehicles, which then take them to their destination. There are many different types of trailers, including single-axle and multi-axle trailers. With multi-axle trailers, a distinction is made between whether they are equipped with a drawbar or without a drawbar. Multi-axle trailers without a drawbar are referred to as semi-trailers or semi-trailers, or internationally as semi-trailers. In these cases, the wheel axles are only on one rear side of the trailer.At the front, these trailers are equipped with supports or stands that can be extended or unfolded to park the trailer and retracted or folded when driving.

[0002] The invention described below is primarily for these semi-trailer trailers. In these cases, the coupling process should be carried out with particular care to avoid damage to the towing vehicle, and especially to the trailer standing on supports. The particular problem is that the towing vehicle is equipped with a coupling element that has a fifth wheel plate. This fifth wheel plate is mounted slightly elevated and pivots. At the rear, the fifth wheel plate has a V-shaped opening into which a so-called kingpin of the trailer vehicle can engage. When coupling, the towing vehicle must be moved back so that the kingpin reaches the opening in the fifth wheel plate. The lateral guides of the V-shaped opening ensure that the kingpin is guided to the central point of the fifth wheel plate.In front of the central hub, locking elements are mounted, held in place by spring force. For the kingpin to engage with the central hub, the locking elements must be pushed sideways against the spring force. For this to happen, the towing vehicle must press firmly against the trailer's kingpin when reversing until it engages with the central hub.

[0003] This is precisely what makes this a difficult task for the driver. They have to check the towing vehicle's length and width simultaneously. Often, the view of the kingpin is not optimal when reversing. Furthermore, the driver is often under increased time pressure. This can lead to reversing at too high a speed, causing the towing vehicle to hit the trailer's kingpin with excessive momentum. This may cause the trailer to shift slightly. This causes the trailer's supports to twist or even shift. This can damage the supports or the trailer's chassis. The towing vehicle's coupling element is also subjected to greater than necessary, which can result in increased wear.

[0004] When the kingpin is engaged at the central point, the snap-back locking elements hold the kingpin in position, ensuring the trailer remains securely connected to the towing vehicle while driving. The locking elements can be released using a mechanism operated by the driver when they want to uncouple the trailer.

[0005] The document US2019039425A1 relates to systems and methods for automatically controlling truck movement for autonomous docking operations.

[0006] Document US2019329612A1 concerns a method for monitoring the coupling of a fifth wheel to a kingpin of a semi-trailer. Vibrations during the coupling process are measured.

[0007] Document DE102018122185A1 concerns a trailer coupling assistance system and method. It calculates a vehicle's reversing distance to the trailer.

[0008] Document DE102014203105A1 relates to a system and method for estimating the length of a trailer based on the signals emitted by a transmitter mounted at the end of a trailer.

[0009] The problem is that the coupling process is often not optimal when performed manually by the driver, resulting in increased wear and tear and potentially damage. This problem is exacerbated by the driver's temptation to couple at a higher speed than absolutely necessary. This way, they can avoid failed coupling attempts and avoid having to start a new coupling process, which would require them to perform the necessary visual inspection again. This would require them to get out of the vehicle again.

[0010] There is therefore a need for improvements in the coupling process to prevent damage and reduce wear.

[0011] The object of the invention is therefore to improve the coupling process in such a way that frequent impacts of the towing vehicle at excessive speed on the trailer vehicle are avoided.

[0012] This object is achieved by a method for assisted or automatic coupling of a trailer vehicle to a towing vehicle according to claim 1, by a device for assisted or automatic coupling of a trailer vehicle to a towing vehicle according to claim 8, a towing vehicle according to claim 15 and an electronic processing unit according to claim 16.

[0013] The dependent claims contain advantageous developments and improvements of the invention according to the following description of these measures.

[0014] In one embodiment, the invention relates to a method for the assisted or automatic coupling of a trailer to a towing vehicle. The towing vehicle is equipped with a coupling element that has a guide, e.g., a lateral guide, for a coupling element of the towing vehicle. Furthermore, the towing vehicle is equipped with an electronically controlled service brake and a drive. The method is characterized in that an automated coupling process is initiated after the towing vehicle is aligned and approached relative to the trailer.The automated coupling process is characterized by the following steps: starting a reversing journey at a specific speed and a specific drive torque, recording the longitudinal and lateral acceleration of the towing vehicle, and, upon the occurrence of lateral acceleration in a first value range, a longitudinal acceleration in a second value range and, subsequently, a longitudinal acceleration in a third value range. Stopping the reversing journey by switching off the drive torque and / or applying the service brake. This method has the advantage that the engagement of the coupling counterpart of the trailer vehicle with the coupling element of the towing vehicle is measured, thus immediately switching off the drive torque of the towing vehicle acting during reversing and preventing the trailer vehicle from shifting due to the continued drive torque of the towing vehicle.This reduces wear and tear and prevents damage to the trailer and towing vehicle.

[0015] In an extended embodiment of the method according to the invention, the condition is required that the third value range be at least a certain value greater than the absolute value of the previously measured lateral acceleration. This has the advantage of preventing contact between the coupling counterpart of the trailer vehicle and the coupling element of the towing vehicle, which would otherwise cause the coupling counterpart to engage with the coupling element of the towing vehicle.

[0016] Particularly advantageous starting conditions for the automated coupling process are that, before starting to reverse, the level of the coupling element of the towing vehicle is adjusted to the height of the trailer vehicle. This is done by checking in one step whether the coupling element of the towing vehicle is in contact with the chassis of the trailer vehicle, and whether the coupling counterpart of the trailer vehicle is positioned within the catch area of ​​the coupling element of the towing vehicle, or there is confirmation from the driver that the trailer vehicle and coupling element are aligned so that the coupling counterpart of the trailer vehicle can engage with the coupling element of the towing vehicle. Under these starting conditions, there is no need for lateral guidance of the towing vehicle during the coupling process, because the lateral guidance of the coupling element essentially ensures lateral guidance.

[0017] An advantageous embodiment of the method for assisted or automatic coupling of a trailer to a towing vehicle consists in setting a specific drive torque of the towing vehicle's drive to initiate reversing, and in regulating the towing vehicle's speed so that a predetermined speed is not exceeded. This limits the drive torque and the speed of the towing vehicle. The impulse generated during the desired impact between the two coupling elements is effectively limited. This also prevents damage and reduces wear.

[0018] The method can be further improved by recording the number of increments of an increment encoder while the towing vehicle is reversing, starting with the measurement of the lateral acceleration in a first value range and simultaneously measuring the longitudinal acceleration in a second value range. Such increment encoders are primarily used for detecting rotary movements. There, they are also referred to as increment wheels. They work in conjunction with a sensor that generates an increment signal whenever an increment of the increment encoder moves past the sensor. These increment signals can be transmitted and counted in a processing unit.

[0019] Incremental encoders are typically designed so that the increments are arranged equidistantly, so that the occurrence of an incremental signal always results in the same rotational movement with a defined angle of rotation. In vehicles, for example, incremental encoders are mounted on the wheels together with wheel speed sensors as incremental encoder sensors. The generated signals are evaluated by various systems, such as ABS (anti-lock braking system) and ASR (traction control system).

[0020] Furthermore, it is advantageous to immediately abort the coupling process if the number of increments recorded during reversing exceeds a certain value, up to which no longitudinal acceleration with a value in the third value range has been measured. This is equivalent to an incorrect height adjustment setting, because the kingpin has already passed the actual impact point.

[0021] A further advantageous measure of the method is that after stopping the reversing drive to verify successful coupling, the service brake on the towing vehicle is released and the trailer is briefly pulled to the towing vehicle by engaging a forward gear and applying a specific drive torque for a defined time, during which time the number of increments of the increment encoder is recorded or the distance between the towing vehicle and trailer is measured. If the trailer is successfully coupled and the parking brake of the trailer is applied, the trailer is not pulled or is only slightly pulled during the brief application of the drive torque. Accordingly, the number of measured increments will be low. If the parking brake on the trailer is released, a larger number of increments will be counted.To verify correct coupling in this case, it is advisable to measure the distance between the trailer and towing vehicle during the coupling process. If the distance remains constant within a tolerance range, the coupling process has been successful.

[0022] Accordingly, it is advantageous if the successful coupling process is confirmed if the recorded number of increments of the increment encoder does not exceed a certain value, or the distance between the towing vehicle and the trailer vehicle measured at the end of the tightening process does not exceed the distance measured at the beginning of the tightening process by more than a tolerance value.

[0023] A further embodiment of the invention consists in a device for controlling the assisted or automatic coupling of a trailer vehicle to a towing vehicle, wherein the towing vehicle is equipped with a drive unit and a coupling element which has a lateral guide for a corresponding coupling counterpart of the trailer vehicle to be inserted into the coupling element, and an electronically controlled service brake. In this embodiment of the invention, the device has an electronic processing unit which is connected via one or more communication buses to the electronic control unit of the drive unit and the electronic control unit of the service brake. The processing unit is set up to communicate with the electronic control unit of the drive unit and the electronic control unit of the service brake in order toTo receive longitudinal and lateral acceleration of the towing vehicle from a sensor unit and to transmit control commands to the electronic control unit of the service brake and the electronic control unit of the drive unit in such a way that the inventive method for controlling the assisted or automatic coupling of a trailer vehicle to a towing vehicle is carried out. The device thus serves to implement the inventive method and can realize the corresponding advantages of the inventive method.

[0024] The aforementioned sensor unit of the device according to the invention should comprise at least a first acceleration sensor that detects the longitudinal acceleration of the towing vehicle and a second acceleration sensor that detects the lateral acceleration of the towing vehicle. It is particularly advantageous if the sensor unit is connected to the electronic control unit of the service brake. The electronic service brake, at least in the version in which the functionality of an electronic stability program (ESP) is integrated, requires such a sensor unit. If this sensor unit is already present, it is only necessary to ensure that the sensor measured values ​​are cyclically transmitted to the processing unit of the device according to the invention. An additional sensor unit is then unnecessary. This reduces the cost of the device according to the invention.

[0025] In another embodiment of the device according to the invention, a separate sensor unit is connected to the processing unit, which serves to measure the longitudinal and lateral acceleration of the towing vehicle. An IMU unit, corresponding to an Inertial Measurement Unit, can be connected to the electronic processing unit as a separate sensor unit. Such IMU units are used in large series in the automotive sector for certain vehicle dynamics control systems, such as ESP. The IMU unit can contain several acceleration sensors and yaw rate sensors. The yaw rate sensors can also be used to measure the yaw rate and vehicle inclination in various directions. In particular, the sensor unit should comprise at least a first acceleration sensor, which detects the longitudinal acceleration of the towing vehicle, and a second acceleration sensor, which detects the lateral acceleration of the towing vehicle.

[0026] A further advantageous embodiment of the device according to the invention consists in that one or more incremental encoder sensors are assigned to the electronic control unit of the service brake, wherein an incremental encoder sensor corresponds either to a wheel speed sensor of the towing vehicle or to a speed sensor of the towing vehicle's transmission. These incremental encoder sensors, especially if they are active wheel speed sensors, can detect the movement of the towing vehicle with relatively high resolution.

[0027] In one embodiment of the device according to the invention, the coupling element of the towing vehicle has a fifth wheel. This is used for coupling trailers in the form of semi-trailers. In these cases, the coupling process must be carried out with particular care because the semi-trailer rests on supports.

[0028] In another embodiment, the coupling element of the towing vehicle has a jaw coupling. This is also provided with a lateral guide for a coupling counterpart, so that the inventive method for coupling a trailer to a towing vehicle can be adapted to it. The coupling counterpart consists of a drawbar of a drawbar trailer.

[0029] A further embodiment of the invention consists in a towing vehicle with a drive unit and an electronically controlled service brake and a coupling element which has a lateral guide for a corresponding coupling counterpart of a trailer vehicle to be inserted into the coupling element and a device according to the invention, as described.

[0030] Furthermore, the invention also consists in an electronic processing unit which is connected via one or more communication buses to the electronic control unit of the drive unit and the electronic control unit of the service brake and is configured to communicate with the drive unit and the electronic control unit of the service brake in order to receive measured values ​​relating to the longitudinal and lateral acceleration of the towing vehicle from a sensor unit and to transmit control commands to the electronic control unit of the service brake and the electronic control unit of the drive unit in such a way that the steps of the automated coupling process can be carried out according to the method according to the invention.

[0031] Finally, a further embodiment of the invention can relate to a computer program that has program instructions that, when processed in a processor unit of a computer, result in the steps of the automated coupling process being carried out according to the method according to the invention.

[0032] Embodiments of the invention are illustrated in the drawings and are explained in more detail below with reference to the figures.

[0033] They show: Fig. 1 shows an example of a depot where trailers are parked, picked up, and maneuvered; Fig. 2 shows a towing vehicle and a trailer in the form of a semi-trailer, wherein the towing vehicle is designed with the coupling element based on a fifth wheel plate and the trailer vehicle is designed with a fifth wheel plate for coupling to the coupling element; Fig. 3 shows a block diagram for the electronic equipment of a towing vehicle; Fig. 4 shows the use of an increment encoder in combination with an active increment encoder sensor for detecting the rotational movement of a vehicle wheel; Fig. 5 shows a flow chart for a computer program for implementing the method according to the invention; Fig. 6 shows a representation of the coupling element and coupling counterpart in the initial situation for coupling the trailer vehicle after alignment of the towing vehicle and trailer vehicle; Fig.Fig. 7 shows a representation of the coupling element and coupling counterpart when the towing vehicle approaches the trailer vehicle for coupling the trailer vehicle; Fig. 8 shows the forces acting when the kingpin of the trailer vehicle hits the right side guide of the fifth wheel plate of the towing vehicle; Fig. 9 shows the force acting on the kingpin of the trailer vehicle during the process of the kingpin engaging in the central position of the fifth wheel plate of the towing vehicle; Fig. 10 shows the speed curve of the towing vehicle during the coupling process; and Fig. 11 shows the typical curve of the acceleration values ​​for the measured longitudinal and lateral acceleration during the coupling process between the trailer vehicle and the towing vehicle.

[0034] The present description illustrates the principles of the inventive disclosure. It is thus understood that those skilled in the art will be able to devise various arrangements that, although not explicitly described herein, embody the principles of the inventive disclosure and are also intended to be protected within their scope.

[0035] Fig. 1 shows the depot 5 of a logistics company from above. There are parking and storage areas where trailers 10 and towing vehicles 20 can be parked. The term trailer 10 here refers to a trailer equipped with a coupling system for a towing vehicle 20. These are primarily commercial vehicle trailers. These are often semi-trailer vehicles equipped with a coupling system in which a so-called kingpin of the trailer is guided into a fifth wheel plate of the towing vehicle until it clicks into place, creating a rotatable connection between the towing vehicle 20 and the trailer 10. However, these can also be other trailers, for example trailers used in agriculture or trailers attached to construction vehicles. Larger caravans, as well as leisure and sports trailers, are also suitable.

[0036] The towing vehicle 20 can be a typical towing vehicle 20. This is equipped with an electronic driving assistant or an electronic driving robot. The driving assistant or the driving robot is designed to simplify or automate the coupling process between the towing vehicle and the trailer vehicle. The reference number 8 designates a central control center of the depot 5. There are various types of trailers, including commercial vehicle trailers. These can differ, for example, in that they are equipped with a drawbar for coupling to the towing vehicle 20 or as semitrailers with a fifth wheel plate. Another distinguishing feature concerns the number of axles. The term trailer vehicle used here is intended to refer to all types of trailer vehicles 10 that are designed as semitrailer vehicles. The principles of the invention can, however, also be applied to other trailer vehicles, for exampleare designed as drawbar trailer vehicles.

[0037] When a trailer vehicle 10 arrives at the depot 5, it is registered in the central control center 8 and a parking space is assigned to the trailer vehicle. The trailer vehicle is parked in the assigned space. Typically, the trailer vehicle 10 does not remain in this space until it is picked up, but is moved to another location for reloading, loading or unloading, or for maintenance purposes. In the following, it is assumed that the trailer vehicle has been moved to a parking space ready for collection. The collection process will now be explained in more detail. The driver who is to pick up the trailer vehicle 10 drives his towing vehicle 20 to the parking space of the trailer vehicle 10 and aligns the towing vehicle 20 to the trailer vehicle 10 so that coupling can take place automatically or with assistance.

[0038] Fig. 2 shows the towing vehicle 20 being aligned with the trailer 10 ready for pickup. As shown, this is a semi-trailer trailer which only has rear wheel axles and stands at the front on extendable or foldable supports 12. First, the towing vehicle 20 is aligned longitudinally with the trailer 10 such that the kingpin enters the catch area of ​​the V-shaped opening of the fifth wheel plate 22-1 as the towing vehicle 20 continues to reverse. In a first variant of the invention, this driving function is still carried out by the driver of the towing vehicle 20. The alignment includes checking whether the fifth wheel plate 22 of the towing vehicle 20 is in contact with the chassis of the trailer 10. The fifth wheel plate 22-1 is typically mounted at an angle so that the open side is lower than the closed side facing the driver's cab.This can be done by visual inspection by the driver or automatically by closing a contact when touched and issuing a message to the driver in the cockpit of the towing vehicle 20.

[0039] The driver who has parked the trailer 10 has also disconnected the electrical and pneumatic connecting lines to the towing vehicle 20. When the connecting lines are disconnected, the spring-loaded parking brake of the trailer 10 is automatically applied. This is done with the help of so-called Tristop cylinders on all or individual wheels of the trailer 10, which are equipped with spring brakes. They ensure, through spring force, that the brake is applied as soon as the Tristop cylinder is no longer pressurized. The trailer 10 is also equipped with a pressure accumulator. As long as this pressure is sufficient, the spring-loaded parking brake can be released again by increasing the pressure in the Tristop cylinder. For this purpose, modern trailers with compressed air-operated brakes are additionally equipped with a parking release safety valve.When the trailer is parked, the parking brake is applied either by the driver applying the handbrake in the towing vehicle 20 or by uncoupling the red coupling head from the towing vehicle 20. Using the black actuation button on the parking release safety valve (release button of the service brake system), the brake system can be released manually after an automatic braking when the vehicle is parked without compressed air supply to the towing vehicle 20, provided there is sufficient reservoir pressure in the accumulator. Using the red actuation button (actuation of the parking brake system), the parking brake can be engaged or released by venting the spring brakes. If the reservoir pressure of the parked trailer drops, the spring brakes automatically assume braking effect and prevent the vehicle from rolling away. In depots, however, it is often the case that the parking brake is released manually by the operating personnel.This is intended to enable faster coupling and uncoupling. This can save time for frequent maneuvering operations at the depot. Therefore, the following assumes that the parking brake of the trailer 10 is either engaged or released during the coupling process. When the parking brake is engaged, the trailer 10 is secured against rolling away. Otherwise, however, it is not. A certain degree of stability is achieved by the fact that the supports 12 on which the trailer 10 stands offer frictional resistance, which also provides less protection against rolling away.

[0040] Fig. 3 shows the structure of an exemplary vehicle electronics system of the towing vehicle 20. Various electronic control units are provided. Block CU1 denotes an electronic engine control module (ECM). Block CU2 denotes an automatic transmission control unit (AMT). Block CU3 denotes an electronic control unit for the retarder unit. This serves to support braking and can prevent the friction brakes on the wheels from overheating. Block CU4 denotes an electronic brake control unit (EBS). Reference numeral 26 represents one service brake per wheel. Each service brake 26 can be actuated separately by the electronic brake control unit (EBS). For this purpose, the corresponding brake lines are connected to the electronic brake control unit (EBS).The reference number IGS designates incremental encoder sensors. These are connected to the electronic braking system EBS of the towing vehicle 20. These are typically magnetic field sensors. An incremental encoder, designed like a gearwheel and having rotating teeth, is mounted on the wheel rims. The gearwheel is typically made of ferromagnetic material. It can be a material suitable for permanent magnets. The incremental encoder sensor IGS generates an electrical pulse when a tooth of the gearwheel moves past the incremental encoder sensor IGS during its rotational movement. To ensure that the pulse can be measured easily, the distance between the rotating incremental encoder and the incremental encoder sensor IGS is chosen to be small.

[0041] Two different types of incremental encoder sensors can be considered. Passive sensors are inductive encoders equipped with a coil and a magnet. The rotational movement of an incremental wheel passing close to the incremental encoder sensor results in a periodic change in the magnetic field, which induces a voltage in the coil of the incremental encoder sensor. However, inductive wheel speed sensors based on this technology have the problem that they only emit an analyzable signal above a certain wheel speed. The signal amplitude depends on the wheel speed (frequency) and the size of the air gap between the wheel speed sensor and the incremental encoder. These disadvantages led to the development of active sensors that use Hall sensors to detect the rotary movement, but whose signals must be processed in their own evaluation electronics.The Hall sensor operates according to the Hall principle and has the unique feature of also being able to detect the direction of rotation. Formally, active and passive wheel speed sensors can be distinguished as follows: If a sensor is only "activated" by applying a supply voltage and then generates an output signal, this sensor is referred to as "active." If a sensor operates without an additional supply voltage, it is referred to as "passive."

[0042] The Fig.4 shows an active incremental encoder sensor IGS, which works together with an incremental encoder in the form of an incremental wheel IGR. In the case shown, it works together with an incremental wheel IGR, which is rigidly connected to a wheel of the towing vehicle 20 or its drive shaft, whose rotational movement is to be detected. The incremental encoder sensor IGS is mounted directly above the incremental wheel IGR. The incremental encoder sensor IGS is designed as an active wheel speed sensor and essentially consists of two components: a sensor unit HS, in which one or more sensor elements are arranged. Examples of such sensor elements are magnetic field sensors, in particular Hall sensors or magnetoresistive resistors. However, other sensor elements could also be used, such as inductive sensors or optical sensors. The other essential component concerns an evaluation electronics EVU.The incremental gear IGR is preferably made of metal and has a number of teeth. For example, there could be 100 teeth on the outer circumference. The number of teeth also determines the resolution with which the incremental encoder sensor IGS can measure the rotation of the gear. With 100 teeth, the resolution for a 19" gear is approximately 1.5 cm. A permanent magnet DM is attached to the sensor unit HSU, whose magnetic effect extends as far as the incremental gear IGR. The rotation of the incremental gear IGR and the associated alternation of teeth and tooth gaps causes a change in the magnetic flux through the sensor unit HS. This changing magnetic field generates a measurable alternating voltage in the sensor elements. This can be used to generate incremental signals, e.g., in the form of square-wave signals, whose periodically recurring waveforms can be counted by an increment counter.

[0043] A pole ring that is rigidly connected to the wheel or its drive shaft can also be used as an increment encoder. The pole ring is typically used in a wheel bearing seal. The pole ring has alternating magnetized zones with magnetic poles N and S. The Hall sensors arranged in the sensor unit detect a changing magnetic field as the multipole ring rotates, generating an alternating current signal that can be converted into a high-resolution square-wave signal whose rectangular pulses can be counted by the increment counter. In this respect, the pole ring can also be considered an increment encoder.

[0044] To the Fig. 3 A sensor unit SU1 is also connected to the processing unit CU4 shown. This sensor unit SU1 contains at least two acceleration sensors, one of which measures the acceleration of the towing vehicle 20 in the longitudinal direction, and the other of which measures the acceleration in the lateral direction. The sensor unit SU1 can optionally contain additional sensors. Typically, a so-called IMU unit (Inertial Measurement Unit) can be used as the sensor unit SU1. Such IMU units are known and often also include yaw rate sensors with which the vehicle's inclination and yaw rate, etc., can be measured. A suitable installation location for the IMU unit SU1 is a central location on the chassis of the towing vehicle 20. If the towing vehicle 20 is equipped with a vehicle stabilization function, such an IMU unit SU1 is required.In the case described, there is no separate control unit for vehicle stabilization, which, by intervening in the engine control system and / or the brake control system and / or the chassis control system, keeps the vehicle stable on course by counteracting the centrifugal forces that occur. Instead, the electronic braking system (EBS) incorporates this function. Alternatively, a separate control unit can be provided for vehicle stabilization. Such a control unit is also called an ESC control unit, corresponding to "Electronic Stability Control."

[0045] Block CU5 designates an electronic control unit of an advanced driving assistance system (ADAS). For example, it could be a lane keeping system that helps the driver stay in their lane when traveling on a multi-lane road, such as a highway. Another type of assistance system is an automatic distance control system that automatically maintains the distance to the vehicle ahead. Block CU6 designates an electronic control unit for a steering system of the towing vehicle 20. Block CU8 designates an electronic control unit for an air suspension system (ECAS) of the towing vehicle 20, corresponding to the electronic control air suspension system. This allows the vehicle level to be raised or lowered. The handling can also be adapted to different road conditions.

[0046] These electronic control units are interconnected via a bus system B1. A bus system designed for in-vehicle communication can be used for this purpose. Serial bus systems are typically used for this purpose, as they require the least amount of cabling. Possible examples include a CAN bus system, corresponding to Controller Area Network. There are various variants of the CAN bus system, such as CAN Low Speed ​​and CAN High Speed, for various data rates from 125 kbit / s to 1000 kbit / s. Furthermore, an extended CAN bus has been specified under the designation CAN-FD bus, where FD stands for "Flexible Data Rate." This specification defines an extended data frame with higher transport capacity and an enlarged payload field.Other automotive bus systems known as Flexray and Automotive Ethernet can also be used to network the electronic control unit. The bus architecture is defined in . Fig. 3 for bus B1 is shown in such a way that a common bus line is used. As an alternative to this representation, it is also possible to provide several different bus lines for this purpose, with only selected control units being connected to one of these bus lines. This is particularly necessary if the data rate is not sufficient to supply all control units with data simultaneously via one bus line. In order for the data to then be forwarded to other control units, it is then necessary to provide one or more gateway stations that can receive the data via a connected bus and forward it to another bus. If the two bus systems for receiving and forwarding are different bus systems, the gateway station is set up to carry out the necessary protocol conversion.

[0047] The vehicle electronics system also consists of two processing units, PU1 and PU2. These processing units can interact to provide one or more automatic driving functions.

[0048] As is well known, the SAE "Society of Automotive Engineering" has defined different levels for automated driving functions. At Level 1, the driver must still be in control, while at Level 5, the vehicle drives fully autonomously, allowing the driver to attend to other tasks.

[0049] The processing unit PU1, also referred to as the "Virtual Driver," can determine a trajectory along which the towing vehicle 20 is to move in the following period. The period can range from a few milliseconds to several minutes. For this purpose, the processing unit PU1 can be connected to a number of environmental detection sensors via another bus system B4. As an example, Fig. 3 One or more cameras SU2 and a LIDAR sensor SU3 are shown. The SU2 cameras can correspond to conventional video cameras. Alternatively or additionally, a RADAR sensor, one or more IR cameras, and one or more ultrasonic sensors (not shown) for environmental detection can be connected. As an example, a suitable bus system B4 for transmitting the camera data and the LIDAR data is the Automotive Ethernet bus system in the IEEE 100BaseT1 or IEEE 1000Base-T1 variant.

[0050] The processing unit PU1 sends the trajectory predicted for the corresponding period to the processing unit PU2 via the communication bus B3. The second processing unit PU2 is designed to convert the specified trajectory into corresponding control commands for the various control units and to control the vehicle so that the vehicle travels along the specified trajectory. These control commands are transmitted via the bus B1 to the various control units CU1 to CU7. This processing unit PU2 can therefore be referred to as a "virtual driving coordinator." This processing unit PU2 is particularly important for "autonomous driving" because it must have precise knowledge of the control commands expected from the electronic control devices and their effects. A display unit DU1 is also connected to the processing unit PU1.This is advantageously arranged as a touch-sensitive display unit (touchscreen) in the cockpit of the towing vehicle 20. This allows a wide variety of operations to be carried out. For this purpose, operating menus are displayed on the display unit. The driver can select menu items, change parameter settings, and make inputs, as is known, for example, from smartphones or tablets. The display unit DU1 is connected to the processing unit PU2 via a bus connection. This is used to transmit the display data, and the operating commands and inputs entered by the driver are transferred from the display unit DU1 to the processing unit PU1. The LVDS bus system (Low Voltage Differential Signal), which was developed for this purpose, is mentioned as an example.

[0051] The Fig. 3 shows a communication module CM1, which is connected to the processing unit PU1 via the communication bus B5. This communication module CM1 is equipped for wireless communication with other vehicles and connection to public communication systems, such as public mobile communication systems, e.g., LTE and 5G. The vehicle can also connect to the internet via this module. For communication with other vehicles, a WLAN module can be provided in the communication module CM1, for example, or the so-called "sidelink" communication capability of the LTE modem or the so-called "PC5" communication capability of the 5G modem can be used for this purpose.

[0052] The functionality of the vehicle electronics to support the coupling process is now explained using the flow chart in Fig. 5 explained. This is designed for the assisted coupling maneuver. The driver has already completed the advance alignment of the towing vehicle 20 with respect to the parked trailer 10 and has requested the assistance function for the coupling maneuver by pressing a switch or selecting a menu item in a user menu on the display unit DU1. The associated computer program is processed by a processor unit in the processing unit PU2. The start of the program for standby mode is designated by the reference symbol S1. In program step S2, the program waits for confirmation from the driver that the towing vehicle 20 and trailer 10 are correctly aligned and that the fifth wheel plate 22-1 is in contact with the chassis of the trailer 10 and the kingpin 14 is located in the catch area 22-5 of the fifth wheel plate 22-1. The fifth wheel plate is height adjustable.The driver can adjust the height of the fifth wheel plate 22-1 using the adjustment device. The height adjustment process is described in the . Fig. 2 indicated by a vertical arrow. One way to adjust the height is to regulate the level of the towing vehicle. This is possible for vehicles with air suspension systems. Another way to achieve height adjustment is to equip the fifth wheel plate with a hydraulic system that adjusts the height of the fifth wheel plate. The process of longitudinal alignment is described in the Fig. 2 indicated by two horizontal arrows. The longitudinal axes of the towing vehicle 20 and the trailer 10 should be aligned parallel. Furthermore, care must be taken to ensure that the towing vehicle 20 is centered relative to the front of the trailer 10 so that the kingpin 14 reaches the catch area 22-5 of the fifth wheel plate 22-1.

[0053] The Fig. 6 shows the initial situation when the towing vehicle 20 is correctly aligned to the trailer vehicle 10. The kingpin of the trailer vehicle 10 is marked with the reference number 14. The longitudinal direction of the towing vehicle 20 is represented by a dash-dotted line with a coordinate system. The longitudinal direction, also called the longitudinal direction, corresponds to the x-axis of this coordinate system. The lateral direction, also called the lateral direction, corresponds to the y-axis of this coordinate system. The hatched area 23 corresponds to the catch area 22-5 of the fifth wheel plate 22-1. The kingpin 14 should be brought into the center of the fifth wheel plate 22-1. For this purpose, the fifth wheel plate 22-1 is designed such that it has a V-shaped opening. The two side surfaces 22-2 of this V-shaped opening serve as sliding surfaces along which the kingpin 14 slides when the towing vehicle 20 does not approach the kingpin 14 quite centrally.The trailer vehicle 10 is then moved slightly laterally so that the kingpin 14 reaches the central position 22-4 in the middle of the fifth wheel plate 22-1. Shortly before entering the locking position, the kingpin 14 must push two locking elements 22-3 to the side so that the central point 22-4 becomes freely accessible. The locking elements 22-3 are held by spring force, so that resistance must be overcome for the kingpin 14 to engage in the central position. The towing vehicle 20 must therefore approach the kingpin 14 at a minimum speed of approximately 1 km / h so that the engagement process can take place.

[0054] If the conditions in query S2 are not yet met, the program branches back to the beginning of the program, so that the query in program step S2 is called again. If all queried conditions are met, a reverse drive of the towing vehicle 20 is started in program step S3 to couple the trailer vehicle 10. To do this, the processing unit PU2 sends a command to engage a reverse gear to the transmission control unit CU2 and another command to set an engine torque to the value M1 to the engine control unit CU1.

[0055] In program step S4, the longitudinal and lateral accelerations ax and ay are recorded. The electronic brake control unit CU4 sends the measured acceleration values ​​to the processing unit PU2. The processing unit PU2 evaluates the acceleration values ​​in the subsequent step S5. Firstly, the evaluation determines whether the lateral acceleration ay occurred in a desired range between Th1 and Th2. To this end, the magnitude of the lateral acceleration ay is compared with the two interval limit values ​​Th1 and Th2. Secondly, it is checked whether the measured longitudinal acceleration ax lies in a specific range between Th3 and Th4. These ranges are selected such that the lateral and longitudinal acceleration typically occurring when the kingpin 14 impacts a side surface 22-2 of the opening in the fifth wheel plate 22-1 of the towing vehicle 20 can be recorded.

[0056] Fig. 7 shows the kingpin 14 approaching the fifth wheel plate 22-1, with the towing vehicle 20 moving back at the desired speed V1.

[0057] Fig. 8 shows the moment at which the kingpin 14 of the trailer vehicle 10 impacts the right side surface 22-2 of the V-shaped opening of the fifth wheel plate 22-1. The force acting on the kingpin 14 is denoted by F. The lateral component of the force F is denoted by Fy. This is accompanied by a corresponding lateral acceleration ay of the towing vehicle 20 acting in the opposite direction. This is measured by the corresponding acceleration sensor of the IMU unit SU1.

[0058] If one or both conditions are not met in query S5 of the computer program, the program branches to step S7, where it waits for the next incoming measured values ​​from the IMU unit SU1. Typically, the electronic brake control unit CU4 sends the measured values ​​from the IMU unit to the processing unit PU2 at 10 ms intervals.

[0059] If both conditions of query S5 are met, the program continues with program step S6. This starts a counter that counts the incremental signals emitted by a wheel speed sensor. The purpose of counting the increments is to measure the distance elapsed from the moment the wheel touches the fifth wheel plate 22-1 until the kingpin 14 hits the center point of the fifth wheel plate 22-1.

[0060] In the next program step S7, the longitudinal and lateral acceleration ax, ay are recorded again. This step therefore corresponds to program step S4.

[0061] In the next program step S8, the number of counted wheel speed sensor increments is evaluated. If the detected wheel speed sensor increment number exceeds the value Th5, the program branches to program step S16, where an error message is generated and displayed to the driver. In this case, a longer distance has already been covered than expected, because the first impact on side surface 22-2 has already occurred. Otherwise, the counting of the increments would not have started in program step S6. The comparison value Th5 is selected such that it is only exceeded if a longer distance was measured than the maximum possible for an impact on one of the side surfaces 24.

[0062] If the value Th5 has not been exceeded, the measured longitudinal acceleration ax is evaluated in the following program step S9. Firstly, it is tested whether the longitudinal acceleration ax is significantly greater than the magnitude of the lateral acceleration ay measured in program step S4. This condition is met when the kingpin 14 hits the central point 22-4 of the fifth wheel plate 22-1 after sliding along a side surface 22-2 in the catch area 22-5 of the fifth wheel plate 22-1. Fig. 11 An example is shown of how much greater the longitudinal acceleration value ax is than the lateral acceleration value typically occurring in a side impact.

[0063] The Fig. 9 shows the situation when the kingpin 14 is engaged at the central point 22-4 of the fifth wheel plate 22-1. In this case, a high force F acts on the kingpin 14 upon impact, which has an exclusively longitudinal component.

[0064] Secondly, query S9 evaluates whether the measured value of the longitudinal acceleration ax exceeds a limit value Th6. This condition can be met if the towing vehicle 20 is moved so centrally relative to the trailer vehicle 10 that the kingpin 14 hits the fifth wheel plate 22-1 at the central point 22-4, and there is no prior contact with the side surface 22-2 in the opening area of ​​the fifth wheel plate 22-1. If neither of the two conditions of query S9 is met, the program branches back to program step S7 and waits for the input of new acceleration values. If one of the conditions is met, a coupling process has been detected. In the following program step S10, the engine torque is then directly reduced to zero and the service brake 26 of the towing vehicle 20 is applied. This is important to prevent the towing vehicle 20 from pushing the trailer further if the parking brake is not applied.This could lead to damage to the supports 12 or the chassis of the trailer vehicle 10.

[0065] Subsequently, in program step S11, the counted increments of the increment encoder sensors IGS are stored in a non-volatile memory area of ​​the processing unit PU2. These values ​​serve as a reference for future coupling processes. A learning function can statistically evaluate these values ​​and, for example, make a prediction as to how many increments it will take for the kingpin 14 to hit the central point 22-4 of the fifth wheel plate 22-1. This can then be used to advance the engine torque shutdown to reduce the impact of the fifth wheel plate 22-1 on the kingpin 14. This can prevent impact damage as effectively as possible.

[0066] In program step S12, the service brake 26 is released by sending a corresponding control command to the electronic brake control unit CU4. A brief pull of the trailer vehicle 10 by the towing vehicle 20 is also started. For this, a control command to engage a forward gear must again be sent to the transmission control unit CU2. A control command to request an engine torque M2 is also sent to the engine control unit CU1. The engine torque is only applied to the drive train of the towing vehicle 20 for a short time, e.g., for 1 s. In the next program step S13, the counting of the wheel speed increments is started for the set time of 1 s. Subsequently, in program step S14, a query is made as to whether the number of counted speed increments exceeds the value Th7. This should not be the case if the parking brake was applied on the trailer vehicle 10.

[0067] Once successful coupling has been confirmed, the parking brake of towing vehicle 20 is applied in program step S15. If query S14 indicates that the Th7 value has been exceeded, the program branches to program step S16, where an error message is displayed to the driver. The program ends in program step S17.

[0068] In the event that the parking brake was not applied, the distance between the towing vehicle 20 and the trailer 10 can be measured at the start and end of the application process, and a query can be provided to compare the two measured values. If the difference does not exceed a tolerance value, the coupling process was successful. The distance can be measured using a camera, ultrasonic sensors, or other measuring technology for distance measurements in the range from a few centimeters to 2 meters.

[0069] After the error message is displayed, the driver will perform a visual inspection and, if necessary, realign the vehicle and restart the coupling process. If the coupling is successful, the driver must still connect the connecting cables between towing vehicle 20 and trailer vehicle 10 before leaving the depot with the trailer vehicle 10 connected.

[0070] The flowchart for the assistance function for coupling a trailer 10 to a towing vehicle 20 has been described in detail. Alternatively, a fully automated coupling can also be implemented using an extended program. During automatic coupling, the towing vehicle 20 would approach the trailer 20 at a low speed. The distance between the towing vehicle 20 and the trailer 10 is monitored. As the approach continues, the speed is reduced to the desired value V1. After that, the process is the same as for the assistance function.

[0071] The Fig. 10 shows the speed curve over distance during the coupling process, once for the assisted coupling process (solid line) and the automatic coupling process (dashed line). The hatched area MEK corresponds to the area in which the kingpin 14 should first make contact with the fifth wheel plate 22-1, until impact at the central point 22-4 of the fifth wheel plate 22-1. The arrow indicates the location of the initial contact.

[0072] The Fig. 11 shows the typical curve of the measured acceleration values ​​ax, ay during the typical coupling process. The distance values ​​are as in Fig. 10 plotted. In the case shown, the first contact of the kingpin 14 occurs on the right side surface 22-2 of the opening of the fifth wheel plate 22-1 at distance 2. A high lateral acceleration ay is measured there. At the same time, a low longitudinal acceleration ax is measured. While the lateral acceleration ay decreases linearly with further approach, the longitudinal acceleration ax remains relatively constant. At point 3 of the distance values, the kingpin 14 engages the central point 22-4 of the fifth wheel plate 22-1. There, a high peak in the longitudinal acceleration ax is measured. This is a factor greater than the lateral acceleration ay previously measured at point 2. In the case shown, the longitudinal acceleration at point 3 is approximately twice as high as the lateral acceleration measured at point 2. If no peak in the longitudinal acceleration ax is observed up to distance 4, the coupling process must be aborted by applying the service brake 26. In Fig. 11 The previously mentioned threshold values ​​Th1 to Th6 are shown. The exact threshold values ​​are determined by series of measurements on a real product during test coupling maneuvers. Fig. 11 The lower diagram also shows the counting of an increment counter. This counter is started by detecting a lateral acceleration ay in the value range between the thresholds Th1 and Th2 and stopped when an impact pulse is detected in the value range above Th6.

[0073] All examples and conditional language mentioned herein are to be understood without limitation to such specifically cited examples. For example, it will be appreciated by those skilled in the art that the block diagram presented herein represents a conceptual view of an exemplary circuit arrangement. Similarly, it will be appreciated that a depicted flowchart, state transition diagram, pseudocode, and the like represent various variations for representing processes that can be substantially stored in computer-readable media and thus executed by a computer or processor.

[0074] It should be understood that the proposed method and associated devices can be implemented in various forms of hardware, software, firmware, special-purpose processors, or a combination thereof. Special-purpose processors may include application-specific integrated circuits (ASICs), reduced instruction set computers (RISCs), and / or field-programmable gate arrays (FPGAs). Preferably, the proposed method and device are implemented as a combination of hardware and software. The software is preferably installed as an application program on a program storage device. Typically, this is a computer platform-based machine that includes hardware such as one or more central processing units (CPUs), random access memory (RAM), and one or more input / output (I / O) interfaces. An operating system is also typically installed on the computer platform.The various processes and functions described here may be part of the application program or a part executed by the operating system.

[0075] The disclosure is not limited to the embodiments described here. List of reference symbols (part of the description)

[0076] 5Depot 8Control Center 10Trailer 12Support 14Kingpin 20Towing Vehicle 22Coupling Element 22-1Fifth Wheel Plate 22-2Side Guide 22-3Locking Element 22-4Central Station 22-5Catch Zone 24Drive Unit 26Service Brake axLongitudinal acceleration ayLateral acceleration CM1On-board communication module CU1Electronic engine control CU2Electronic transmission control CU3Electronic retarder control CU4Electronic brake control CU5Electronic driver assistance system CU6Electronic steering system CU7Electronic chassis control DMPermanent magnet EVUEvaluation unit GNDGround IGRIncrement wheel IGSIncrement encoder sensor HSUHall sensor unit M11. Drive torque M22. Drive torque MEKPresumed first contact area PU1Electronic processing unit (Virtual Driver) PU2Electronic processing unit (Virtual Driving Coordinator) SU1IMU unit SU2Camera SU3LIDAR sensor Th11. Threshold value Th22. Threshold value Th33. Threshold value Th44. Threshold value Th55. Threshold value Th66. Threshold value Th77. Threshold S1-S17 various program steps of a computer program V11. Speed ​​V22. Speed ​​Vcc supply voltage

Claims

1. Method for assisted or automatic coupling of a trailer vehicle (10) to a towing vehicle (20), the towing vehicle (20) being equipped with a coupling element (22), which has a side guide (22-2) for a corresponding coupling counterpart (14) of the trailer vehicle (10) to be inserted into the coupling element (22), an electronically regulated service brake (26) and a drive unit (24), an automated coupling process being started, after the towing vehicle (20) has been aligned with and brought closer to the trailer vehicle (10), which process comprises the steps of starting a reverse movement at a specific speed and at a specific drive torque (M1; S3), recording the longitudinal acceleration and the lateral acceleration (S4) of the towing vehicle (20), and which automated coupling process is characterized by the steps of, upon the occurrence of a lateral acceleration (ay) in a first value range (Th1, Th2) with the occurrence of a longitudinal acceleration (ax) in a second value range (Th3, Th4; S5) and the subsequent occurrence of a longitudinal acceleration (ax) in a third value range (S9), stopping the reverse movement (S10) by switching off the drive torque (M1) and / or by actuating the service brake (26).

2. Method according to claim 1, wherein the third value range is at least a specific value greater than the absolute value of the previously recorded lateral acceleration (ay).

3. Method according to claim 1 or claim 2, characterized in that before starting the reverse movement (S3), the level of the towing vehicle (20) is adjusted to the height of the trailer vehicle (10), and in one step (S2) it is checked whether the coupling element (22) is in contact with the chassis of the trailer vehicle (10), whether the coupling counterpart (14) of the trailer vehicle (10) is positioned in the catch region (22-5) of the coupling element (22) of the towing vehicle (20), or whether there is confirmation from the driver that the trailer vehicle (10) and the coupling element (22) are correspondingly aligned (S2).

4. Method according to any of the preceding claims, characterized in that to start the reverse movement, a specific drive torque of the drive unit (24) of the towing vehicle (20) is set (S3), and the speed of the towing vehicle (20) is regulated during the reverse movement such that a predetermined speed (V1) is not exceeded.

5. Method according to any of the preceding claims, characterized in that after identifying the occurrence of the lateral acceleration (ay) in the first value range (Th1, Th2) with the occurrence of the longitudinal acceleration (ax) in the second value range (Th3, Th4), the number of increments of an incremental counter (IGR) is recorded during the reverse movement.

6. Method according to claim 5, characterized in that the coupling process is aborted if the number of increments recorded during the reverse movement exceeds a specific value (Th7) up to which no longitudinal acceleration (ax) having a value in the third value range was measured.

7. Method according to any of the preceding claims, characterized in that after stopping the reverse movement, the service brake (26) is released to verify the successful coupling, and a short pull on the trailer vehicle (10) is carried out (S12) using the towing vehicle (20) by engaging a forward gear and applying a specific drive torque (M2) for a defined time, during which time the number of increments of the incremental counter (IGR) is recorded (S13) or the distance between the towing vehicle (20) and the trailer vehicle (10) is measured.

8. Method according to claim 7, characterized in that the successful coupling process is confirmed (S14) if the recorded number of increments of the incremental counter does not exceed a specific value, or if the distance between the towing vehicle (20) and the trailer vehicle (10) measured at the end of the pulling process does not exceed the distance measured at the beginning of the pulling process by more than a tolerance value.

9. Device for controlling the assisted or automatic coupling of a trailer vehicle (10) to a towing vehicle (20), the towing vehicle (20) being equipped with a drive unit (24) and a coupling element (22), which has a side guide (22-2) for a corresponding coupling counterpart (14) of the trailer vehicle (10) to be inserted into the coupling element (22), and an electronically regulated service brake (26),characterized in that the device has an electronic processing unit (PU2) which is connected to the electronic control unit (CU1) of the drive unit (24) and to the electronically regulated service brake (26) via one or more communication buses (B1), and which processing unit is set up to communicate with the electronic control unit (CU1) of the drive unit (24) and with the electronic control unit (CU4) of the service brake (26) in order to receive measured values regarding longitudinal acceleration and lateral acceleration of the towing vehicle (20) from a sensor unit (SU1) and to transmit control commands to the electronic control unit (CU4) of the service brake (26) and to the electronic control unit (CU1) of the drive unit (24) in such a way that the steps of the automated coupling process are carried out according to a method according to any of claims 1 to 8.

10. Device according to claim 9, wherein the sensor unit (SU1) is attached to the electronically regulated service brake (26), which sensor unit serves to measure the longitudinal acceleration and lateral acceleration of the towing vehicle (20).

11. Device according to claim 9, wherein a separate sensor unit (SU1) is attached to the processing unit (PU2), in particular a sensor unit in the form of a separate IMU unit, corresponding to an inertial measurement unit, which serves to measure the longitudinal acceleration and lateral acceleration of the towing vehicle (20).

12. Device according to any of claims 9 to 11, characterized in that the sensor unit (SU1) comprises at least a first acceleration sensor, which records the longitudinal acceleration of the towing vehicle (20), and a second acceleration sensor, which records the lateral acceleration of the towing vehicle (20).

13. Device according to any of claims 9 to 11, characterized in that one or more incremental counter sensors (IGS) are assigned to the electronically regulated service brake (26), an incremental counter sensor (IGS) corresponding to either a wheel speed sensor of the towing vehicle (20) or to a speed sensor of a transmission of the towing vehicle (20).

14. Device according to any of claims 9 to 13, characterized in that the coupling element (22) of the towing vehicle (20) comprises a fifth wheel plate (22-1) or a jaw coupling.

15. Towing vehicle comprising a drive unit (24) and an electronically regulated service brake (26), and a coupling element (22) which has a side guide (24) for a corresponding coupling counterpart (14) of a trailer vehicle (10) to be inserted into the coupling element (22),characterized in that the towing vehicle (20) has a device according to any of claims 9 to 14.

16. Electronic processing unit which can be connected to the electronic control unit (CU1) of the drive unit (24) and to the electronic control unit (CU4) of the service brake (26) via one or more communication buses (B1), and which processing unit is set up to communicate with the drive unit (24) and with the electronic control unit (CU4) of the service brake (26) in order to receive measured values regarding longitudinal acceleration and lateral acceleration of the towing vehicle (20) from a sensor unit (SU1) and to send control commands to the electronic control unit (CU4) of the service brake (26) and to the electronic control unit (CU1) of the drive unit (24) in such a way that the steps of the automated coupling process can be carried out according to a method according to any of claims 1 to 8.

17. Computer program, characterized in that the computer program comprises program commands which, when executed in a processor unit of a computer, lead to the steps of the automated coupling process being carried out according to a method according to any of claims 1 to 8.