DE102021115400A1 - Method and device for brake control of a vehicle train - Google Patents

Abstract

The invention relates to a method for controlling the brakes of a vehicle combination, consisting of a towing vehicle (18) and a trailer vehicle (19), the towing vehicle having a pneumatic or hydraulic towing vehicle brake system (33) and the trailer vehicle having a pneumatic or hydraulic trailer brake system (34), for example. The invention also relates to a device (50) for carrying out such a method and a vehicle train, consisting of the towing vehicle (18) and the trailer vehicle (19), which is designed and equipped in such a way that the method mentioned can be operated on it. In the method, at least one thrust threshold value (F_x1, F_x2) for overrun operation of the trailer vehicle and a target value (p_s1, p_s2) of the trailer control pressure (p) assigned to the at least one thrust threshold value are stored in a control device (30). In an overrun mode of the trailer vehicle, the target value of the trailer control pressure is set when the thrust force (F_x) reaches or exceeds the thrust force threshold value, and an existing trailer control pressure is reduced or dissipated when the thrust force falls below the thrust force threshold value.

Description

The invention relates to a method for controlling the brakes of a vehicle combination, consisting of a towing vehicle and a trailer vehicle, the towing vehicle having a pneumatic or hydraulic towing vehicle brake system and the trailer vehicle having, for example, a pneumatic or hydraulic trailer brake system, with an electrically controllable trailer control valve, with a pneumatic or hydraulic trailer control line, with an electronic control device for controlling a trailer control pressure of the trailer brake system via the trailer control valve and the trailer control line, and with a measuring device for measuring forces and/or moments between the towing vehicle and the trailer vehicle. This measuring device can be arranged and connected to a coupling device for coupling the towing vehicle to the trailer vehicle. The measuring device has at least one force sensor and an electronic measurement data acquisition and evaluation unit, which is electrically connected to the at least one force sensor on the input side and to the electronic control device on the output side. The measurement data acquisition and evaluation unit is designed to acquire and evaluate electrical sensor signals of the at least one force sensor, which are caused by force- and/or torque-related deformations of the coupling device. In addition, the electronic measurement data acquisition and evaluation unit has an electronic circuit and/or a computer program with an algorithm, by means of which the coupling forces, coupling torques and/or their components acting on the coupling device can be determined in terms of size and direction and in a time-resolved manner, and the electronic control device for Control of the trailer control pressure of the trailer brake system are available.

The invention also relates to a device for carrying out such a method and a vehicle train which is designed and equipped in such a way that the method mentioned can be operated on it.

When actuating the brakes of such a vehicle combination, consisting of a towing vehicle and at least one trailer vehicle that can be towed by the towing vehicle, the brake pressure at the brake actuators of the trailer vehicle can be regulated by means of an electrically controllable trailer control valve, via which a trailer control line can be subjected to a pneumatic or hydraulic pressure. In order to achieve harmonious braking behavior of a vehicle combination, the braking effect coordination between the towing vehicle and the trailer vehicle is regulated in a standard. Accordingly, when activating a trailer control valve, the compatibility bands defined in EU Regulation 2015/68 must be observed, which specify the permissible brake pressure at the coupling head of the towing vehicle or on the trailer control line depending on the deceleration values of both individual vehicles.

However, experience has shown that the desired harmonious braking behavior of the vehicle combination is not achieved in many cases, either because the relatively wide spread compatibility bands only result in less than optimal brake tuning, or because the braking systems of older trailer vehicles, such as are still often used in agricultural applications are to be found in the area are not readily controllable taking into account the compatibility bands. With some vehicle trains, such as agricultural vehicle trains, other off-highway vehicle trains or trucks for heavy and special transport, the brake adjustment is often problematic anyway, since such combinations can have very different masses in use and the coupling force between the vehicles can vary greatly. If the towing vehicle in a vehicle combination, for example a farm tractor, has a continuously variable automatic transmission, such as a hydrostatic continuously variable automatic transmission, the vehicle combination can be severely decelerated simply by changing the transmission ratio, for example by actuating an operating lever or by decelerating, without the service brake being required for this purpose must be actuated. The same applies to active engine brakes or active continuous braking. If the service brake is not actuated or if the trailer brakes are not actuated in a coordinated manner, such a delay means that the trailer control line remains pressureless or is subjected to an unregulated brake pressure and the trailer vehicle is not braked or is braked only insufficiently.

In the case of incorrect or missing brake tuning, it can therefore happen that the actual deceleration does not correspond to the required deceleration according to the mentioned compatibility bands on certain vehicle trains and/or in special driving conditions. This can lead to excessive coupling forces and in particular to very high thrust forces between the towing vehicle and the trailer vehicle and, as a result, to instability of the vehicle combination. This can lead to dangerous situations when driving downhill, for example. In particular, a possibly dangerous buckling of the vehicle combination at the coupling point, the so-called called "jack-knifing", feared in critical driving situations.

From the DE 42 43 245 A1 a brake control on a vehicle train is known in which a horizontal actual component and a vertical actual component of a force acting between a towing vehicle and a trailer vehicle and a vehicle deceleration are determined when the brake is actuated by means of a force measuring device. From the vertical actual component and from the vehicle deceleration, a horizontal target component is calculated using an algorithm. By supplying braking energy, the horizontal actual component is adjusted to the horizontal target component of the force between the individual vehicles. This is to ensure stability-optimized braking of the vehicle combination at all operating points. A suitable force measuring device for measuring the actual component of the coupling force between a towing vehicle and a trailer vehicle is not described.

From the DE 10 2018 001 695 A1 a brake control of a trailer vehicle of a vehicle combination is known, in which variable trailer control valve characteristics are used for brake control of the trailer vehicle. By varying the trailer brake pressure as a function of relevant parameters, compliance with the compatibility bands of the brake coordination between the individual vehicles should be made easier. In order to achieve a harmonious brake adjustment of a vehicle train, for example in an off-highway vehicle train, such as an agricultural tractor-trailer combination or in a semi-trailer truck or bridge train for special transports, it is proposed to determine the coupling force between the tractor vehicle and the trailer vehicle and to vary a trailer control valve characteristic depending on the coupling force. A force measuring device for determining such a coupling force is also not described therein.

From the DE 10 2016 104 453 A1 a brake control of an agricultural vehicle combination is known, in which a control device actuates at least one brake system of a tractor vehicle and/or a brake system of a trailer vehicle of the train depending on a determined overrun operation of the train and/or the towing vehicle, the overrun operation depending on at least one operating parameter of the agricultural Train, such as a force acting on or on the towing vehicle, a torque, an engine speed, a transmission parameter, a support torque and/or a slip of ground-engaging means of the train is determined. For the determination of a coupling force between the individual vehicles, reference is only made in general terms to a force measuring sensor on a coupling of the towing vehicle to which the trailer is attached.

The non-prepublished PCT/ EP2020/083163 the applicant proposes a measuring device for measuring forces and/or moments between a towing vehicle and a trailer vehicle of a vehicle combination. The measuring device has a carrier designed as a measuring cross, which has several measuring arms and which can be arranged and connected to a coupling device for coupling the towing vehicle to the trailer vehicle. A strain gauge rosette is arranged on each measuring arm of the carrier, each of which consists of at least three strain gauges arranged at an angle to one another and acting as force sensors. The measuring device is assigned an electronic measurement data acquisition and evaluation unit, which is electrically connected or can be connected to the strain gauge rosettes, and which is used to acquire and evaluate force- and/or torque-related deformations of the coupling device and correlated electrical sensor signals with strain changes in the strain gauge rosettes in all three spatial directions is formed. This measuring device enables the determination of coupling forces, coupling moments and/or their components acting on the coupling device, both in terms of magnitude and direction and in a time-resolved manner.

Against this background, the invention is based on the object of specifying a method for controlling the brakes of a vehicle combination, by means of which stable driving behavior of the vehicle combination with low coupling forces is achieved and ensured when a trailer vehicle is coasting. In particular, reliable and at the same time harmonious braking coordination between the towing vehicle and the trailer vehicle should be ensured when braking the trailer vehicle in all deceleration situations of the vehicle combination. Furthermore, in the case of off-highway vehicle combinations, such as an agricultural tractor-trailer combination or other off-highway vehicle combinations, which are driven by the operation of a continuously variable automatic transmission in the drive train, an engine brake, a permanent brake and/or by a very different mass distribution between Towing vehicle and trailer can be subject to large coupling forces and spontaneous strong vehicle deceleration, an improved and more harmonious brake tuning can be achieved. Finally, the method should also be used in on-highway vehicle trains, for example in articulated lorries, can be used with advantage. A further object consists in presenting an apparatus for carrying out this method.

The solution to the process-related task is achieved with a process that has the features of an independent process claim. To solve the device-related task, the device has the features of an independent device claim. Advantageous refinements and developments of the method and the device are defined in the associated dependent claims.

According to the features of independent claim 1, the invention relates to a method for controlling the brakes of a vehicle combination consisting of a towing vehicle and a trailer vehicle, the towing vehicle having a pneumatic or hydraulic towing vehicle brake system and the trailer having a pneumatic or hydraulic trailer brake system. The trailer brake system includes an electrically controllable trailer control valve, a pneumatic or hydraulic trailer control line, an electronic control device for controlling a trailer control pressure of the trailer brake system via the trailer control valve and the trailer control line, and a measuring device for measuring forces and/or moments between the towing vehicle and the trailer vehicle.

In this case, the measuring device can be arranged on a coupling device for coupling the towing vehicle to the trailer vehicle and can be connected to it. The measuring device has at least one force sensor and an electronic measurement data acquisition and evaluation unit, which is electrically connected to the at least one force sensor on the input side and to the electronic control device on the output side. The measuring device is designed to record and evaluate electrical sensor signals from the at least one force sensor, which are - And/or moment-related deformations of the coupling device are caused. The electronic measurement data acquisition and evaluation unit has an electronic circuit and/or a computer program with an algorithm, by means of which the coupling forces, coupling torques and/or their components acting on the coupling device can be determined in terms of size and direction and in a time-resolved manner, as well as the electronic control device for control of the trailer control pressure of the trailer brake system can be made available.

1. a) Festlegen und Abspeichern mindestens eines Schubkraftschwellwertes F_x1, F_x2 für einen Schubbetrieb des Anhängefahrzeuges in der elektronischen Steuereinrichtung,
2. b) Festlegen und Abspeichern eines dem mindestens einen Schubkraftschwellwert F_x1, F_x2 zugeordneten Sollwertes p_s1, p_s2 des Anhängersteuerdruckes p in der elektronischen Steuereinrichtung,
3. c) Erkennen und Überwachen eines Schubbetriebes des Anhängefahrzeuges mittels der Messeinrichtung und fortlaufendes Ermitteln der Schubkraft F_x in dem erkannten Schubbetrieb,
4. d) Einstellen des Sollwertes p_s1, p_s2 des Anhängersteuerdruckes p, wenn die Schubkraft F_x den Schubkraftschwellwert F_x1, F_x2 erreicht oder überschreitet, sowie
5. e) Verringern oder Abbauen eines vorhandenen Anhängersteuerdruckes p, wenn die Schubkraft den Schubkraftschwellwert F_x1, F_x2 unterschreitet.

At least the following process steps are carried out in the process according to the invention:

1. a) determining and storing at least one thrust force threshold value F_x1, F_x2 for overrun operation of the trailer vehicle in the electronic control device,
2. b) determining and storing a setpoint value p_s1, p_s2 of the trailer control pressure p assigned to the at least one thrust threshold value F_x1, F_x2 in the electronic control device,
3. c) detection and monitoring of overrun operation of the trailer vehicle using the measuring device and continuous determination of the overrun force F_x in the detected overrun operation,
4. d) setting the target value p_s1, p_s2 of the trailer control pressure p when the thrust force F_x reaches or exceeds the thrust force threshold value F_x1, F_x2, and
5. e) Reduction or dissipation of an existing trailer control pressure p when the thrust force falls below the thrust force threshold value F_x1, F_x2.

The measuring device for measuring forces and/or moments between the towing vehicle and the trailer vehicle is designed in such a way that it can be used on a coupling device between the towing vehicle and the trailer vehicle to measure those forces which act in the forward direction of travel of the towing vehicle and/or the trailer vehicle.

Different types of sensors can be used on the measuring device to measure the forces at the coupling point between the towing vehicle and the trailer vehicle. In the simplest embodiment, strain gauges can be used in the usual arrangement or more specifically in the rosette arrangement described above. It is also possible to use piezoelectric sensors or, for example, surface wave sensors for the force measurement mentioned.

A trailer control valve is understood to mean a valve unit consisting of one or more valves, which is electrically connected to an electronic control device for controlling a brake system of a trailer vehicle. A trailer control line is understood to mean a pressure line which can be pressurized or vented via the trailer control valve with a fluid pressure medium and which supplies the brake cylinders of the trailer brakes with the pressure medium. The trailer control valve is connected to the trailer control line via a control pressure outlet commonly referred to as the "yellow control pressure coupling head". hungwise connectable. A trailer control pressure is understood to mean a pneumatic or hydraulic pressure of a fluid pressure medium with which the trailer control line can be acted upon. To complete it, it should be mentioned that the reservoir pressure from a pressure fluid reservoir is usually routed through the trailer control valve and to a reservoir pressure outlet referred to as a “red reservoir pressure coupling head”, to which a reservoir line of the trailer brake can be coupled.

The method according to the invention provides a function which adjusts a trailer brake pressure as a function of a measured coupling force, in particular as a function of a thrust force, between a towing vehicle and a trailer vehicle on a vehicle combination. With the method it is possible to achieve a largely coupling force-free braking behavior of such a vehicle combination.

According to the development of the invention defined in claim 2, a method for controlling the brakes of a vehicle combination is also claimed, which consists of a towing vehicle and a trailer vehicle. The towing vehicle has a pneumatic or hydraulic towing vehicle brake system and the trailer has a pneumatic or hydraulic trailer brake system. The trailer brake system includes an electrically controllable trailer control valve, a pneumatic or hydraulic trailer control line, an electronic control device for controlling a trailer control pressure of the trailer brake system via the trailer control valve and the trailer control line, and a measuring device for measuring forces and/or moments between the towing vehicle and the trailer vehicle.

In this technically further developed example, the measuring device has a multi-armed measuring cross which can be arranged and connected to a coupling device for coupling the towing vehicle to the trailer vehicle. A strain gauge rosette acting as a force sensor is arranged on each measuring arm of the measuring cross.

The measuring device also has an electronic measurement data acquisition and evaluation unit which is electrically connected to the strain gauge rosettes on the input side and to the electronic control device on the output side. The measurement data acquisition and evaluation unit is designed to acquire and evaluate electrical sensor signals in all three spatial directions caused by deformations of the coupling device caused by force and/or moment and correlated with strain changes of the strain gauge rosettes. In addition, the electronic measurement data acquisition and evaluation unit has an electronic circuit and/or a computer program with an algorithm, by means of which the coupling forces, coupling torques and/or their components acting on the coupling device can be determined in terms of size and direction and in a time-resolved manner, as well as the electronic control device Control of the trailer control pressure of the trailer brake system are available.

1. a) Festlegen und Abspeichern mindestens eines Schubkraftschwellwertes F_x1, F_x2 für einen Schubbetrieb des Anhängefahrzeuges in der elektronischen Steuereinrichtung,
2. b) Festlegen und Abspeichern eines dem mindestens einen Schubkraftschwellwert F_x1, F_x2 zugeordneten Sollwertes p_s1, p_s2 des Anhängersteuerdruckes p in der elektronischen Steuereinrichtung,
3. c) Erkennen und Überwachen eines Schubbetriebes des Anhängefahrzeuges mittels der Messeinrichtung und fortlaufendes Ermitteln der Schubkraft F_x in dem erkannten Schubbetrieb,
4. d) Einstellen des Sollwertes p_s1, p_s2 des Anhängersteuerdruckes p, wenn die Schubkraft F_x den Schubkraftschwellwert F_x1, F_x2 erreicht oder überschreitet, sowie
5. e) Verringern oder Abbauen eines vorhandenen Anhängersteuerdruckes p, wenn die Schubkraft den Schubkraftschwellwert F_x1, F_x2 unterschreitet.

Even with this technically advanced brake system, at least the following method steps are carried out in the method according to the invention:

1. a) determining and storing at least one thrust force threshold value F_x1, F_x2 for overrun operation of the trailer vehicle in the electronic control device,
2. b) determining and storing a setpoint value p_s1, p_s2 of the trailer control pressure p assigned to the at least one thrust threshold value F_x1, F_x2 in the electronic control device,
3. c) detection and monitoring of overrun operation of the trailer vehicle using the measuring device and continuous determination of the overrun force F_x in the detected overrun operation,
4. d) setting the target value p_s1, p_s2 of the trailer control pressure p when the thrust force F_x reaches or exceeds the thrust force threshold value F_x1, F_x2, and
5. e) Reduction or dissipation of an existing trailer control pressure p when the thrust force falls below the thrust force threshold value F_x1, F_x2.

According to the two embodiment variants presented, the method can basically be used on vehicle trains of all types. It is particularly advantageous to use it on so-called off-highway vehicle combinations, such as agricultural tractors with attached implements or trailers coupled to them, or on vehicle combinations from the construction or mining industry or on special transporters. In the case of these vehicle trains, it has hitherto been difficult to comply with the compatibility bands mentioned at the outset for harmonious brake tuning in all driving situations or operating situations.

The method with the features of the invention achieves this according to the second variant with the aid of a measuring cross with strain gauge rosettes Measuring device that enables the coupling forces between the towing vehicle and the trailer vehicle to be determined in all three spatial directions. In simple applications, a three-dimensional evaluation can be dispensed with and only one coupling force component, in particular in the direction of travel, can be taken into account for the brake control. However, in combination with this measuring device, the method has the potential to always comply with the compatibility bands, even in very complex driving and operating situations. Safe and comfortable braking behavior of such a vehicle combination is advantageously achieved at all times by means of the method.

During a braking operation with the service brake of a vehicle train in normal operation, the trailer control valve delivers an output pressure to the trailer control line in order to initiate a braking effect on the trailer. According to the EU regulation mentioned at the outset, this trailer control pressure should be within the specified compatibility bands, depending on the vehicle deceleration caused by the braking process. In the case of a vehicle combination and/or in the case of a special situation where this regulation is not practicable or cannot be satisfactorily controlled, the trailer vehicle may start to push the towing vehicle. Under certain circumstances, this can lead to the disadvantageous situations already described.

With the method according to the invention, the pushing of the trailer vehicle is detected by means of the coupling force measuring device and processed in the electronic control device. For this purpose, the electronic control device includes a software function in which at least one threshold value for the thrust force is set. As soon as this threshold value is exceeded, the electronic control device initiates an increase in the trailer control pressure in the amount of a previously defined desired value. The trailer vehicle can now be decelerated more strongly by the additional brake pressure, so that the coupling force, in particular the thrust force, between the towing vehicle and the trailer vehicle is reduced. This reliably prevents the trailer vehicle from swinging out or similar undesirable situations on the vehicle combination. The driving safety and the driving comfort of the vehicle combination are increased as a result.

Another advantage of the proposed method is its use in vehicles with a continuously variable transmission. In modern agricultural vehicle combinations, such transmissions can decelerate the tractor with great force. With such a deceleration of the towing vehicle via the transmission, there may be no active braking pressure that can control the trailer brakes in order to set a harmonized braking behavior. This can lead to dangerous situations, especially when driving downhill. In this case, too, the method described can detect the coupling force between the towing vehicle and the trailer vehicle by means of the measuring device. If the trailer vehicle pushes the towing vehicle and the information is available that the towing vehicle designed as a tractor is in overrun mode with a thrust force above the specified threshold, brake pressure can be applied automatically to the trailer control line. This stabilizes the vehicle combination and avoids critical driving situations.

According to a development of the method with the features of the invention, it can be provided
that a first thrust threshold value F_x1 as a lower threshold value,
a second thrust threshold value F_x2 as an upper threshold value,
a first target value p_s1 of the trailer control pressure p assigned to the first thrust threshold value F_x1 as a lower target value and a second target value p_s2 of the trailer control pressure p assigned to the second thrust force threshold value F_x2 are specified as an upper target value and stored in the electronic control device, wherein
f) when the lower thrust force threshold value F_x1 is reached or exceeded, the lower target value p_s1 of the trailer control pressure p is set,
g) when the upper thrust force threshold value F_x2 is reached or exceeded, the upper target value p_s2 of the trailer control pressure p is set,
h) if the upper thrust force threshold value F_x2 is not reached, the lower target value p_s1 of the trailer control pressure p is set as soon as the lower thrust force threshold value F_x1 is reached, and
i) the trailer control pressure p is reduced when the thrust force falls below the lower threshold value F_x1.

The braking effect on the brakes of the trailer vehicle therefore follows the change in the brake pressure on the brake system with a delay corresponding to the response behavior of the brakes. The actual deceleration of the vehicle also depends on various factors, such as the condition of the road. On the other hand, in practice, the measured thrust can fluctuate around the defined thrust threshold. To account for this It has proven to be advantageous if the trailer control pressure of the vehicle combination that is in overrun mode is increased or decreased within a relatively narrow control pressure range between two stages. Accordingly, the trailer control pressure is not completely reduced when it falls below an upper thrust threshold, but initially only reduced by a certain value. The control pressure is reduced further only when the thrust falls below a lower threshold. This advantageously achieves a particularly gentle and at the same time safe braking of the trailer vehicle and thus a particularly harmonious braking adjustment of the vehicle combination. In particular, this regulation reliably avoids a tendency for the trailer to sway as a result of braking and acceleration processes that may occur in quick succession and change several times during the overrun mode. In addition, a smooth transition from overrun operation to traction operation of the vehicle combination is advantageously supported.

Finally, a very largely coaxial alignment of the towing vehicle and the trailer vehicle with regard to their longitudinal axes can be achieved by sensitively braking the trailer vehicle. According to another development of the method presented, it can therefore be provided that the setpoint value or values p_s1, p_s2 of the trailer control pressure p are set abruptly, step-by-step or continuously. Accordingly, the adjustment of the brake pressure and thus the braking or releasing of the trailer vehicle can be spontaneous, graded or gradual as required.

According to a further embodiment of the method, it can be provided that a brake pressure change at the trailer brake system that has occurred as a result of the setting of the setpoint value or values p_s1, p_s2 of the trailer control pressure p is time-limited. It can thereby be ensured that when the vehicle combination is in use, braking pressure is not permanently applied to the trailer brakes in an undesired manner and/or unnoticed.

According to another embodiment of the method, it can be provided that the trailer control pressure p is set in such a way that an overrun operation of the vehicle combination is converted into a light traction operation. It has been found that a particularly stable driving behavior of a vehicle combination can be achieved by slightly excessive braking pressure on the trailer brakes. Accordingly, it is advantageous to reduce the trailer control pressure when overrun operation of the trailer vehicle is detected, or to increase this trailer control pressure beyond a coupling force-free setting even in the direction of towing operation of the trailer vehicle.

The method according to the invention can also be used to solve the task on a brake control device of a vehicle combination of the type described, which does not use a pneumatic or hydraulic trailer control line but an electric trailer control line to signal a braking force requirement to the brake actuators of the trailer vehicle. These brake actuators can be pneumatically, hydraulically or electrically operated brake actuators.

As mentioned above, the invention also relates to a device for controlling the brakes of a vehicle combination consisting of a towing vehicle and a trailer vehicle, the towing vehicle having a pneumatic or hydraulic towing vehicle brake system and the trailer having a pneumatic or hydraulic trailer brake system. The device includes an electrically controllable trailer control valve, a pneumatic or hydraulic trailer control line, an electronic control device for controlling a trailer control pressure of the trailer brake system via the trailer control valve and the trailer control line, and a measuring device for measuring forces and/or moments between the towing vehicle and the trailer vehicle. The measuring device can be arranged and connected to a coupling device for coupling the towing vehicle to the trailer vehicle.

At least one force sensor is arranged on the measuring device and it has an electronic measurement data acquisition and evaluation unit which is electrically connected to the at least one force sensor on the input side and to the electronic control device on the output side. The measurement data acquisition and evaluation unit is designed to acquire and evaluate electrical sensor signals which are caused by force- and/or torque-related deformations of the coupling device and are correlated with strain changes in the force sensors. For this purpose, the electronic measurement data acquisition and evaluation unit has an electronic circuit and/or a computer program with an algorithm, by means of which the coupling forces, coupling torques and/or their components acting on the coupling device can be determined in terms of size and direction and with a time resolution, as well as the electronic control device for Control of the trailer control pressure of the trailer brake system are available.

In order to solve the device-related task, the invention provides that the electronic control device has electronic means for receiving, storing and processing information on coupling forces F_x and trailer control pressures p as well as threshold values F_x1, F_x2 and setpoint values p_s1, p_s2 assigned to coupling forces F_x and trailer control pressures p.

• - mit einem elektrisch steuerbaren Anhängersteuerventil,
• - mit einer pneumatischen oder hydraulischen Anhängersteuerleitung,
• - mit einer elektronischen Steuereinrichtung zur Steuerung eines Anhängersteuerdruckes der Anhängerbremsanlage über das Anhängersteuerventil und die Anhängersteuerleitung, und
• - mit einer Messeinrichtung zum Messen von Kräften und/oder Momenten zwischen dem Zugfahrzeug und dem Anhängefahrzeug,
• - wobei die Messeinrichtung ein mehrarmiges Messkreuz aufweist,
• - welches an einer Koppelvorrichtung zum Koppeln des Zugfahrzeugs mit dem Anhängefahrzeug anordbar und mit dieser verbindbar ist,
• - wobei an jedem Messarm des Messkreuzes jeweils eine als Kraftsensor wirksame Dehnungsmessstreifenrosette angeordnet ist,
• - wobei die Messeinrichtung außerdem eine elektronische Messdatenerfassungs- und Auswerteeinheit aufweist,
• - welche eingangsseitig mit den Dehnungsmessstreifenrosetten und ausgangsseitig mit der elektronischen Steuereinrichtung elektrisch verbunden ist, und
• - welche zur Erfassung sowie Auswertung von durch kraft- und/oder momentbedingten Verformungen der Koppelvorrichtung hervorgerufenen, mit Dehnungsänderungen der Dehnungsmessstreifenrosetten korrelierten elektrischen Sensorsignalen in allen drei Raumrichtungen ausgebildet ist,
• - wobei die elektronische Messdatenerfassungs- und Auswerteeinheit eine elektronische Schaltung und/oder ein Computerprogramm mit einem Algorithmus aufweist, mittels der oder dem die auf die Koppelvorrichtung wirkenden Koppelkräfte, Koppelmomente und/oder deren Komponenten nach Größe und Richtung sowie zeitaufgelöst bestimmbar sowie der elektronischen Steuereinrichtung zur Steuerung des Anhängersteuerdruckes der Anhängerbremsanlage zur Verfügung stellbar sind, und
• - wobei die elektronische Steuereinrichtung elektronische Mittel zum Empfangen, Speichern und Verarbeiten von Informationen von Koppelkräften F_x und Anhängersteuerdrücken p sowie den Koppelkräften F_x und Anhängersteuerdrücken p zugeordneten Schwellwerten F_x1, F_x2 und Sollwerten p_s1, p_s2 aufweist.

According to a second variant, the device-related object is achieved by a device for controlling the brakes of a vehicle combination consisting of a towing vehicle and a trailer vehicle, the towing vehicle having a pneumatic or hydraulic towing vehicle brake system and the trailer vehicle having a pneumatic or hydraulic trailer brake system.

• - with an electrically controllable trailer control valve,
• - with a pneumatic or hydraulic trailer control line,
• - With an electronic control device for controlling a trailer control pressure of the trailer brake system via the trailer control valve and the trailer control line, and
• - with a measuring device for measuring forces and/or moments between the towing vehicle and the trailer vehicle,
• - wherein the measuring device has a multi-arm measuring cross,
• - which can be arranged and connected to a coupling device for coupling the towing vehicle to the trailer vehicle,
• - a strain gauge rosette acting as a force sensor is arranged on each measuring arm of the measuring cross,
• - wherein the measuring device also has an electronic measurement data acquisition and evaluation unit,
• - Which is electrically connected to the strain gauge rosettes on the input side and to the electronic control device on the output side, and
• - which is designed to record and evaluate electrical sensor signals in all three spatial directions caused by force- and/or torque-related deformations of the coupling device and correlated with strain changes in the strain gauge rosettes,
• - wherein the electronic measurement data acquisition and evaluation unit has an electronic circuit and/or a computer program with an algorithm, by means of which the coupling forces, coupling torques and/or their components acting on the coupling device can be determined in terms of size and direction and in a time-resolved manner, and the electronic control device for Control of the trailer control pressure of the trailer brake system are available, and
• - wherein the electronic control device has electronic means for receiving, storing and processing information on coupling forces F_x and trailer control pressures p and the coupling forces F_x and trailer control pressures p associated threshold values F_x1, F_x2 and setpoint values p_s1, p_s2.

Accordingly, the measuring device has a multi-armed measuring cross, which can be arranged and connected to a coupling device for coupling the towing vehicle to the trailer vehicle. A strain gauge rosette acting as a force sensor is arranged on each measuring arm of the measuring cross. In addition, the measuring device has an electronic measurement data acquisition and evaluation unit which is or can be electrically connected to the strain gauge rosettes on the input side and to the electronic control device on the output side.

The measurement data acquisition and evaluation unit is designed to acquire and evaluate electrical sensor signals in all three spatial directions caused by deformations of the coupling device caused by force and/or moment and correlated with strain changes of the strain gauge rosettes. The electronic measurement data acquisition and evaluation unit has an electronic circuit and/or a computer program with an algorithm, by means of which the coupling forces, coupling torques and/or their components acting on the coupling device can be determined in terms of size and direction and in a time-resolved manner, as well as the electronic control device for control of the trailer control pressure of the trailer brake system can be made available. In addition, the electronic control device has electronic and computational means for receiving, storing and processing information on coupling forces F_x and trailer control pressures p as well as threshold values F_x1, F_x2 and setpoint values p_s1, p_s2 assigned to coupling forces F_x and trailer control pressures p.

The measurement data acquisition and evaluation unit used to carry out the method according to the invention is advantageously integrated into the measuring device for measuring forces and/or moments between the towing vehicle and the trailer vehicle. This measurement data acquisition and evaluation unit acts as a first electronic device of the trailer brake control system.

The integrated measurement data acquisition and evaluation unit can calculate the coupling force on the basis of the raw data generated by the strain gauge rosettes on the measuring arms of the measuring cross and advantageously transmit the determined force information to the electronic control unit via a data connection, for example a CAN data bus in the vehicle forward onto. The electronic control device, which is designed to control the trailer control pressure of the trailer brake system via the trailer control valve and the trailer control line, then advantageously acts as a second electronic device of the system, which provides the function for brake control of the trailer brakes in overrun mode and implements it in braking mode.

At this point it should be pointed out that the device for controlling the brakes of a vehicle combination can have an electric trailer control line for signaling a braking force requirement to the brake actuators of the trailer vehicle instead of a pneumatic or hydraulic trailer control line.

The functions of this electrical device for controlling the brakes of the vehicle combination, in particular for controlling the brakes of the trailer vehicle, do not change in comparison to a trailer brake system controlled by pressure medium. Therefore, the method with the features of the invention can also be operated advantageously without restrictions on such a brake control of a vehicle train.

Finally, the invention relates to a vehicle combination consisting of a towing vehicle and a trailer, such as an agricultural tractor with an attachment or trailer coupled to it, another off-highway vehicle combination, a tractor with a trailer from the construction or mining industry or a truck for heavy and special transport, with a device for controlling the brakes of the vehicle train, which is constructed according to at least one of the device claims and can be operated to carry out a method according to one of the method claims.

• 1 eine perspektivische Vorderansicht eines Messkreuzes einer Messeinrichtung zur Durchführung des Verfahrens gemäß der Erfindung,
• 2 eine Rückseitenansicht des Messkreuzes gemäß 1 mit einer Anordnung von Dehnungsmessstreifenrosetten,
• 3 eine schematisch stark vereinfachte Schnittdarstellung durch die Messeinrichtung im eingebauten Zustand sowie im Zusammenwirken mit anderen Mitteln der Gesamtvorrichtung, und
• 4 ein Diagramm zur Erläuterung der Funktionsweise des Verfahrens zur Bremssteuerung eines Fahrzeugzuges gemäß einer Ausführungsform der Erfindung.

The invention is explained in more detail below with reference to an exemplary embodiment illustrated in the attached drawing. In the drawing shows

• 1 a perspective front view of a measuring cross of a measuring device for carrying out the method according to the invention,
• 2 a rear view of the measuring cross according to FIG 1 with an array of strain gauge rosettes,
• 3 a schematically greatly simplified sectional view through the measuring device in the installed state and in interaction with other means of the overall device, and
• 4 a diagram to explain the functioning of the method for braking control of a vehicle combination according to an embodiment of the invention.

the 1 shows the front side of a measuring cross 2 of a measuring device 1, facing a towing vehicle 18, for measuring coupling forces and coupling torques on a coupling device 21, which is used, for example, for the detachable connection of a towing vehicle 18, such as a tractor, to a trailer vehicle 19, designed as a drawbar trailer, of an agricultural vehicle combination (see also 3 ). In the already mentioned patent application PCT/ EP2020/083163 a similar measuring device of such a vehicle combination is described in more detail by the same applicant. The vehicle train has a towing vehicle brake system 33 and a trailer brake system 34, which are components of a known electronic brake system of the vehicle train and therefore do not need to be explained further here. According to one embodiment of the PCT/ EP2020/083163 However, such a measuring device can also be designed in such a way that it is arranged on a coupling device of a tractor-trailer vehicle and can measure coupling forces and coupling torques there.

Accordingly, in the 1 The illustrated measuring cross 2 for measuring coupling forces and coupling torques on the coupling device 21 has two measuring arms 3a, 3b, 3c, 3d which are offset from one another by 60° or 120°. Eyes 4a, 4b, 4c, 4d with through-holes 5a, 5b, 5c, 5d for receiving fastening screws are formed on the respective free end of these measuring arms, the eyes 4a, 4b, 4c, 4d each having an axial projection 6a, 6b, 6c , 6d have. The measuring cross 2 is provided with a central carrier part 7 which is designed as a hub and protrudes axially on one side, which is essentially cylindrical but has flattened edges. A central threaded bore 8 is formed in the carrier part 7, through which a fastening screw can be passed (see FIG 3 ). However, the measuring cross 2 can also have several Have threaded holes for carrying out one fastening screw each.

the 2 shows the rear of the measuring cross 2 of the measuring device 1 facing the trailer vehicle 19 or drawbar trailer or semi-trailer. A strain gauge rosette 9, 10, 11, 12 is arranged on each measuring arm 3a, 3b, 3c, 3d. The back of the measuring cross 2 is in the area of the central support part 7, and also up to the eyes 4a, 4b, 4c, 4d of the free ends of the measuring arms 3a, 3b, 3c, 3d, for receiving the respective strain gauge rosette 9, 10, 11, 12 deepened. The respective strain gauge rosette 9, 10, 11, 12 is arranged as close as possible to the respective eye 4a, 4b, 4c, 4d and is firmly connected to the measuring cross material, for example materially. The respective strain gauge rosettes 9 , 10 , 11 , 12 are each connected to an electronic measurement data acquisition and evaluation unit 17 via a six-wire electrical line 13 , 14 , 15 , 16 .

This measurement data acquisition and evaluation unit 17 has electronic computing and storage means known per se, by means of which the electrical signals, which are correlated with strains or with strain changes of the strain gauge rosettes 9, 10, 11, 12, can be evaluated in order to determine forces and moments , to which the coupling device 21 is exposed. The strain gauge rosettes 9, 10, 11, 12 are in the already mentioned international patent application PCT / EP2020/083163 described in more detail, so that a further explanation can be dispensed with here. However, their disclosure content is adopted here in full. In addition, the measurement data acquisition and evaluation unit 17 has an electrical or optical interface 43 for transmission of the coupling force information digitized and amplified in the measurement data acquisition and evaluation unit 17 to an electronic control device 30 .

The electronic control device 30 is designed to control the trailer control pressure p of the trailer brake system 34 via a trailer control valve 31 and a trailer control line 32 . For this purpose, the trailer control line 32 is connected pneumatically or hydraulically to the trailer brake system 34 (see 3 ). The electronic control device 30 can also be a component part of the electronic brake system of the vehicle combination, which, as mentioned, can be embodied as an example of an agricultural vehicle combination or a tractor-trailer vehicle.

The data transmission between the measurement data acquisition and evaluation unit 17 and the electronic control device 30 takes place via a wireless or wired data connection 35, for example via a CAN data bus present on the vehicle. To fulfill its tasks, the electronic control device 30 has electronic means 40 for receiving, storing and processing information on coupling forces F_x and trailer control pressures p as well as threshold values F_x1, F_x2 and setpoint values p_s1, p_s2 assigned to the coupling forces F_x and trailer control pressures p. This is still in connection with the 4 received.

the 3 shows a schematic example of the measuring cross 2 just described in the installed state on the coupling device 21. The coupling device 21 has a box-shaped standard hitch 22, a standard coupling carrier 23 with invisible locking means for fixing the same to the hitch 22, a connection plate 24 and a jaw coupling 25 with a base plate 25a. The measuring cross 2 is aligned perpendicular to an imaginary geometric longitudinal axis 26 of the vehicle combination. In the one already mentioned above DE 10 2018 106 855 A1 a similar standard hitch 22 and a similar standard hitch carrier 23 are described so that they do not need to be explained further here. It is only important that the measuring cross 2 is fastened between the hitch 22 and the jaw coupling 25 in order to fulfill its measuring tasks.

The method according to the invention is subsequently carried out at an in 4 illustrated time course of a brake control of a designed as a drawbar trailer trailer 19 explained in a coasting mode. For this purpose, an exemplary course of a thrust component F_x in the direction of travel over time t is plotted in the upper half of the figure. In the lower half of the figure, the course of a target value setting of a trailer control pressure p for this thrust course is shown over time t. The course of the thrust force of the vehicle combination is decisively determined by the brake control according to the invention.

Accordingly, the beginning of the overrun operation is detected at a first point in time t0. At this point in time, the trailer control line 32 is depressurized or, at most, is subjected to an initially unregulated control pressure. The trailer vehicle 19 thus begins to push the towing vehicle 18 so that the thrust force F_x increases and at a second point in time t1 reaches a first lower thrust force threshold value F_x1. This lower thrust threshold F_x1 is in the Steuereinrich 30 saved. At this point in time t1, the trailer control line 32 is subjected to a pressure which corresponds to a first lower trailer control pressure setpoint value p_s1 stored in the control device 30. As a result, the thrust force F_x continues to increase, but with a lower gradient F_x(t). The increase in thrust force thus slows down and, at a third time t2, reaches a second upper thrust force threshold value F_x2, which is also stored in control device 30 . At this third point in time t2, trailer control line 32 is subjected to a pressure whose value corresponds to a second upper trailer control pressure setpoint value p_s2 that is also stored in the memory of control device 30. The trailer 19 is braked further as a result, so that the thrust force F_x briefly rises only slightly above the second thrust force threshold F_2 and then decreases as soon as the higher braking pressure takes effect.

At a fourth point in time t3, the decreasing thrust F_x of the trailer vehicle 19 falls below the upper threshold F_x2 and continues to decrease. At a fifth point in time t4, the thrust force F_x of the trailer vehicle 19 reaches the lower thrust force threshold F_x1. At this fifth point in time t4, the upper trailer control pressure setpoint p_s2 is deactivated and the lower trailer control pressure setpoint p_s1 on the trailer control line 32 is set again. The thrust F_x then drops further, so that at a sixth point in time t5 the lower trailer control pressure setpoint p_s1 is deactivated and the trailer control pressure is reduced, possibly down to the value zero.

The process just described can change, as in 4 indicated in the further course of time, repeat over several cycles until the overrun operation of the trailer vehicle 19 has ended. In any case, the trailer vehicle 19 is braked in such a way that the brake coordination of the vehicle combination lies within the compatibility bands described at the outset.

reference list

1

measuring device

2

measuring cross

3a

First measuring arm of the measuring cross 2

3b

Second measuring arm of the measuring cross 2

3c

Third measuring arm of the measuring cross 2

3d

Fourth measuring arm of the measuring cross 2

4a

Eye on the first measuring arm 3a

4b

Eye on the second measuring arm 3b

4c

Eye on the third measuring arm 3c

4d

Eye on the fourth measuring arm 3d

5a

Through hole at the eye of the first measuring arm 3a

5b

Through-hole at the eye of the second measuring arm 3b

5c

Through hole at the eye of the third measuring arm 3c

5d

Through-hole on the eye of the fourth measuring arm 3d

6a

Axial projection of the eye on the first measuring arm 3a

6b

Axial projection of the eye on the second measuring arm 3b

6c

Axial projection of the eye on the third measuring arm 3c

6d

Axial projection of the eye on the fourth measuring arm 3d

7

Central carrier part of measuring cross 2, hub

8th

Central threaded hole in the carrier part 7

9

First strain gauge rosette on measuring cross 2

10

Second strain gauge rosette on measuring cross 2

11

Third strain gauge rosette on measuring cross 2

12

Fourth strain gauge rosette on measuring cross 2

13

First electric line

14

Second electrical line

15

Third electrical line

16

Fourth electric line

17

Measurement data acquisition and evaluation unit

18

towing vehicle, tractor

19

Trailer vehicle, drawbar trailer

21

coupling device

22

trailer hitch

23

Standard hitch carrier

24

connection plate

25

jaw coupling

25a

base plate

26

Geometric longitudinal axis of the vehicle combination

30

Electronic control device

31

trailer control valve

32

trailer control line

33

towing vehicle braking system

34

trailer braking system

35

Data connection, CAN bus

40

Electronic means of the control device 30

43

Interface for data transmission

50

contraption

F_x

Coupling force component in x-direction (direction of travel), shear force

F_x1

First thrust threshold, Lower thrust threshold

F_x2

Second Thrust Threshold, Upper Thrust Threshold

p

trailer control pressure

p_s1

First target value of the trailer control pressure, lower target value

p_s2

Second target value of the trailer control pressure, upper target value

t

time

t1 - t5

times

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 4243245 A1 [0006]
• DE 102018001695 A1 [0007]
• DE 102016104453 A1 [0008]
• EP2020083163 [0009, 0046, 0049]
• DE 102018106855 A1 [0052]

Claims (11)

Method for controlling the brakes of a vehicle train, consisting of a towing vehicle (18) and a trailer vehicle (19), - wherein the towing vehicle (18) has a pneumatic or hydraulic towing vehicle brake system (33) and the trailer vehicle (19) has a pneumatic or hydraulic trailer brake system (34), - with an electrically controllable trailer control valve (31), - with a pneumatic or hydraulic trailer control line (32), - with an electronic control device (30) for controlling a trailer control pressure (p) of the trailer brake system (34) via the trailer control valve (31) and the trailer control line (32), - with a measuring device (1) for measuring forces and/or moments between the towing vehicle (18) and the trailer vehicle (19), - wherein the measuring device (1) can be arranged and connected to a coupling device (21) for coupling the towing vehicle (18) to the trailer vehicle (19), - wherein the measuring device (1) has at least one force sensor (9, 10, 11, 12), - wherein the measuring device (1) also has an electronic measurement data acquisition and evaluation unit (17), - Which is electrically connected to the at least one force sensor (9, 10, 11, 12) on the input side and to the electronic control device (30) on the output side, and - which is designed to record and evaluate electrical sensor signals from the at least one force sensor (9, 10, 11, 12) which are caused by force- and/or torque-related deformations of the coupling device (21), - wherein the electronic measurement data acquisition and evaluation unit (17) has an electronic circuit and/or a computer program with an algorithm, by means of which the coupling forces, coupling torques and/or their components acting on the coupling device (21) can be determined in terms of size and direction and in a time-resolved manner and can be made available to the electronic control device (30) for controlling the trailer control pressure (p) of the trailer brake system (34). , and in which at least the following method steps are carried out: a) defining and storing at least one thrust threshold value (F_x1, F_x2) for overrun operation of the trailer vehicle (19) in the electronic control device (30), b) determining and storing a setpoint value (p_s1, p_s2) of the trailer control pressure (p) assigned to the at least one thrust threshold value (F_x1, F_x2) in the electronic control device (30), c) detecting and monitoring overrun operation of the trailer vehicle (19) using the measuring device (1) and continuously determining the overrun force (F_x) in the detected overrun operation, d) setting the target value (p_s1, p_s2) of the trailer control pressure (p) when the thrust force (F_x) reaches or exceeds the thrust force threshold value (F_x1, F_x2), and e) Reduction or dissipation of an existing trailer control pressure (p) when the thrust force falls below the thrust force threshold value (F_x1, F_x2). Method for controlling the brakes of a vehicle combination, consisting of a towing vehicle (18) and a trailer vehicle (19), - the towing vehicle (18) having a pneumatic or hydraulic towing vehicle brake system (33) and the trailer vehicle (19) having a pneumatic or hydraulic trailer brake system (34). , - with an electrically controllable trailer control valve (31), - with a pneumatic or hydraulic trailer control line (32), - with an electronic control device (30) for controlling a trailer control pressure (p) of the trailer brake system (34) via the trailer control valve (31) and the Trailer control line (32), - with a measuring device (1) for measuring forces and/or moments between the towing vehicle (18) and the trailer vehicle (19), - the measuring device (1) having a multi-arm measuring cross (2), - which can be arranged and connected to a coupling device (21) for coupling the towing vehicle (18) to the trailer vehicle (19), - wherein a strain gauge rosette (9, 10, 11, 12) acting as a force sensor is arranged on each measuring arm (3a, 3b, 3c, 3d) of the measuring cross (2), - the measuring device (1) also having an electronic measurement data acquisition and evaluation unit ( 17), - which is electrically connected to the strain gauge rosettes (9, 10, 11, 12) on the input side and to the electronic control device (30) on the output side, and - which is used to record and evaluate deformations of the coupling device caused by force and/or torque (21) and correlated with strain changes in the strain gauge rosettes (9, 10, 11, 12) electrical sensor signals in all three spatial directions, - the electronic measurement data acquisition and evaluation unit (17) being an electronic circuit and/or a computer program with an algorithm has, by means of or the on the coupling forces, coupling torques and/or their components acting on the coupling device (21) can be determined in terms of size and direction and in a time-resolved manner and can be made available to the electronic control device (30) for controlling the trailer control pressure (p) of the trailer brake system (34), in which at least the following Method steps are carried out: a) determining and storing at least one thrust threshold value (F_x1, F_x2) for overrun operation of the trailer vehicle (19) in the electronic control device (30), b) determining and saving a setpoint value assigned to the at least one thrust threshold value (F_x1, F_x2). (p_s1, p_s2) of the trailer control pressure (p) in the electronic control device (30), c) detecting and monitoring overrun operation of the trailer vehicle (19) using the measuring device (1) and continuously determining the overrun force (F_x) in the detected overrun operation, d ) Setting the target value (p_s1, p_s2) of the trailer control pressure (p) when the thrust force (F_x) reaches or exceeds the thrust force threshold value (F_x1, F_x2), and e) reducing or reducing an existing trailer control pressure (p) when the thrust force falls below the thrust force threshold value (F_x1, F_x2). procedure after claim 1 or claim 2 , characterized in that a first thrust threshold value (F_x1) as a lower threshold value, a second thrust threshold value (F_x2) as an upper threshold value, a first target value (p_s1) of the trailer control pressure (p) assigned to the first thrust force threshold value (F_x1) as a lower target value and a second target value (p_s2) of the trailer control pressure (p) assigned to the second thrust threshold value (F_x2) is defined as an upper target value and stored in the electronic control device (30), f) when the lower thrust threshold value (F_x1) is reached or exceeded, the lower Target value (p_s1) of the trailer control pressure (p) is set, g) when the upper thrust force threshold value (F_x2) is reached or exceeded, the upper target value (p_s2) of the trailer control pressure (p) is set, h) when the upper thrust force threshold value (F_x2) is not reached the lower target value (p_s1) of the trailer control pressure (p) is set, sob as soon as the lower thrust force threshold value (F_x1) is reached, and i) the trailer control pressure (p) is reduced when the thrust force threshold value (F_x1) falls below the lower value. Procedure according to one of Claims 1 until 3 , characterized in that the setting of the target value or values (p_s1, p_s2) of the trailer control pressure (p) occurs abruptly, in steps or continuously. Procedure according to one of Claims 1 until 4 , characterized in that a change in brake pressure at the trailer brake system (34) that has taken place as a result of the setting of the setpoint value or values (p_s1, p_s2) of the trailer control pressure (p) is limited in time. Procedure according to one of Claims 1 until 5 , characterized in that the trailer control pressure (p) is adjusted in such a way that an overrun operation of the trailer vehicle (19) is reduced or converted into a light traction operation. Procedure according to one of Claims 1 until 6 , characterized in that this does not use a pneumatic or hydraulic trailer control line (32), but an electric trailer control line for signaling a braking force requirement to the brake actuators of the trailer vehicle (19). Device (50) for controlling the brakes of a vehicle combination consisting of a towing vehicle (18) and a trailer vehicle (19), - the towing vehicle (18) having a pneumatic or hydraulic towing vehicle brake system (33) and the trailer vehicle (19) having a pneumatic or hydraulic trailer brake system (34 ) has, - with an electrically controllable trailer control valve (31), - with a pneumatic or hydraulic trailer control line (32), - with an electronic control device (30) for controlling a trailer control pressure (p) of the trailer brake system (34) via the trailer control valve (31) and the trailer control line (32), - with a measuring device (1) for measuring forces and/or moments between the towing vehicle (18) and the trailer vehicle (19), - the measuring device (1) on a coupling device (21) for coupling of the towing vehicle (18) can be arranged with the trailer vehicle (19) and connected to it, - with at least one Kr force sensor (9, 10, 11, 12), - the measuring device (1) also having an electronic measurement data acquisition and evaluation unit (17), - which is connected to the at least one force sensor (9, 10, 11, 12) on the input side and on the output side is electrically connected to the electronic control device (30), and - which for the detection and evaluation of by force- and/or moment-related deformations of the coupling device (21) and correlated with changes in strain of the force sensors (9, 10, 11, 12), - the electronic measurement data acquisition and evaluation unit (17) having an electronic circuit and/or has a computer program with an algorithm, by means of which the coupling forces, coupling torques and/or their components acting on the coupling device (21) can be determined in terms of size and direction and in a time-resolved manner, and the electronic control device (30) for controlling the trailer control pressure (p) of the trailer brake system (34) can be made available, and - the electronic control device (30) having electronic means (40) for receiving, storing and processing information on coupling forces (F_x) and trailer control pressures (p) and the coupling forces (F_x) and trailer control pressures (p ) assigned threshold values (F_x1, F_x2) and target values (p_s1, p_s2). Device (50) for controlling the brakes of a vehicle combination consisting of a towing vehicle (18) and a trailer vehicle (19), the towing vehicle (18) having a pneumatic or hydraulic towing vehicle brake system (33) and the trailer vehicle (19) having a pneumatic or hydraulic trailer brake system (34) having, - with an electrically controllable trailer control valve (31), - with a pneumatic or hydraulic trailer control line (32), - with an electronic control device (30) for controlling a trailer control pressure (p) of the trailer brake system (34) via the trailer control valve (31) and the trailer control line (32), - with a measuring device (1) for measuring forces and/or moments between the towing vehicle (18) and the trailer vehicle (19), - wherein the measuring device (1) has a multi-arm measuring cross (2), - which can be arranged and connected to a coupling device (21) for coupling the towing vehicle (18) to the trailer vehicle (19), - a strain gauge rosette (9, 10, 11, 12) acting as a force sensor being arranged on each measuring arm (3a, 3b, 3c, 3d) of the measuring cross (2), - wherein the measuring device (1) also has an electronic measurement data acquisition and evaluation unit (17), - Which is electrically connected to the strain gauge rosettes (9, 10, 11, 12) on the input side and to the electronic control device (30) on the output side, and - which is designed to record and evaluate electrical sensor signals in all three spatial directions caused by force- and/or torque-related deformations of the coupling device (21) and correlated with strain changes in the strain gauge rosettes (9, 10, 11, 12), - wherein the electronic measurement data acquisition and evaluation unit (17) has an electronic circuit and/or a computer program with an algorithm, by means of which the coupling forces, coupling torques and/or their components acting on the coupling device (21) are analyzed in terms of size and direction and in a time-resolved manner can be determined and made available to the electronic control device (30) for controlling the trailer control pressure (p) of the trailer brake system (34), and - wherein the electronic control device (30) has electronic means (40) for receiving, storing and processing information on coupling forces (F_x) and trailer control pressures (p) as well as threshold values (F_x1, F_x2) assigned to the coupling forces (F_x) and trailer control pressures (p) and setpoint values (p_s1, p_s2). device after claim 8 or claim 9 , characterized in that instead of a pneumatic or hydraulic trailer control line (32), this has an electric trailer control line for signaling a braking force requirement to the brake actuators of the trailer vehicle (19). A vehicle combination consisting of a towing vehicle (18) and a trailer vehicle (19), such as an agricultural tractor with an implement or trailer coupled thereto, another off-highway vehicle combination, a tractor unit with a trailer used in the construction or mining industry, or a truck for heavy and special transport, with a device for controlling the brakes of the vehicle train, which is constructed according to one of the device claims and can be operated to carry out a method according to one of the method claims.

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