DE102016220905A1 - Device and method for controlling the driving operation of a vehicle with a trailer - Google Patents

Abstract

Device (1) for controlling the driving operation of a vehicle (2) with a trailer (4), wherein both the vehicle (2) and the trailer (4) each have a separate drive unit (23, 42) comprising at least at least one synchronization unit (27), which adjusts a coordinated control of at least one rotational speed or torque with respect to the vehicle (2) and trailer (4), and at least one relative traction analysis unit (18) sets up the actual traction difference to vehicle (2) occurring during driving operation. and trailer (4) and to intervene in the synchronization unit (27). Further, a method for controlling the driving operation of a vehicle (2) with a trailer (4) is proposed, wherein both the vehicle (2) and the trailer (4) each have a separate drive unit (23, 42), and a synchronized operation the two drive units (23, 42) in the vehicle (2) and trailer (4) is automatically adjusted depending on a current difference in traction between the vehicle (2) and trailer (4).

Description

The present invention relates to a device and a method for controlling the driving operation of a vehicle with a trailer, in particular a tractor, as well as a suitable operating method for this purpose. As "trailer" in particular, an attachment is understood, which is connected via an articulated joint or a rotary joint with the towing vehicle. In particular, the invention finds application in a vehicle in the manner of a tractor, a agricultural or forestry tractor, a mobile machine, a truck or the like. Such vehicles are used in particular in agriculture, also can also be used in mining operations or on construction sites.

There is known a tractor which has a powerful generator to provide electric powered implements or trailers with an electric traction axle. The main benefit of such drive axles in the trailer is a jamming of the team on slippery ground z. B. to prevent the turnip crop. If the traction force of the tractor is significantly lower than that of the trailer, it can lead to an undesirable and dangerous buckling of the team when cornering. Here, the rear of the tractor is pushed away from the trailer side. Since the electric axle is used especially on slippery terrain, this danger is particularly great. An example of this would be to drive the tractor on a slippery wet floe or ramp, while the trailer is still on dry grippy ground. If the traction of the tractor then breaks off, the lateral guidance of the tires is no longer possible.

On this basis, it is an object of the present invention to provide a device and a method which alleviate or even avoid the disadvantages mentioned. In particular, the operation of a trailer on a vehicle is to be improved in a structurally simple manner. In addition, the method should provide a control for a trailer, which avoids a jamming and buckling of the trailer and vehicle team.

These objects are achieved with a device and a method according to the independently formulated claims. Further embodiments of the invention are specified in the dependent formulated claims. It should be noted that the description, in particular in conjunction with the figures, further details and developments of the invention, which can be combined with the features of the claims.

• - mindestens eine Synchronisationseinheit, die eine abgestimmte Regelung zumindest einer Drehzahl oder eines Drehmoments bezüglich Fahrzeug und Anhänger einstellt, und
• - mindestens eine Relativ-Zugkraft-Analyseeinheit, eingerichtet die im Fahrbetrieb auftretende aktuelle Zugkraftdifferenz an Fahrzeug und Anhänger zu ermitteln und in die Synchronisationseinheit einzugreifen.

Contributing to this is a device for controlling the driving operation of a vehicle with a trailer, wherein both the vehicle and the trailer each have a separate drive unit and the device comprises at least the following:

• - At least one synchronization unit, which adjusts a coordinated control of at least one rotational speed or torque with respect to vehicle and trailer, and
• - At least one relative tensile force analysis unit, set up to detect the current traction difference occurring on the vehicle and trailer while driving and to intervene in the synchronization unit.

The vehicle is in particular one of the aforementioned type, preferably a tractor. As a trailer of the type mentioned is considered, in particular a rigid drawbar trailer or a similar trailer. If an additional trailer should be used, it must be coupled behind the driven trailer. The trailer may take the form of a semi-trailer on the vehicle. The trailer may include an agricultural implement, a liquid tank, or the like. The trailer forms with the vehicle a trailer-vehicle-team.

The vehicle has a drive unit with the example, a driver's side predetermined power output is realized. Likewise, the trailer has its own drive unit, which realizes in particular a predetermined by the vehicle power output. For this purpose, a synchronization unit is provided which adjusts a coordinated control of at least one rotational speed or torque with respect to the vehicle and the trailer. Thus, it can be provided that the driver-side predetermined power output is divided according to a predetermined tuned control on both drive units, for example, in such a way that both drive units each realize a fixed or variable portion of the entire driver side predetermined power output. It should be pointed out that control variables attributable to rotational speed and / or torque can also be used for this, such as, for example, a speed, a pulling force or the like.

Furthermore, the device comprises a relative tensile force analysis unit, which can determine an occurring during driving current difference in traction between the vehicle and trailer and can intervene in the synchronization unit. The relative tensile force analysis unit may measure, determine and / or calculate the (actual) relative tensile force. The determination of the actual draft difference allows monitoring to what extent the given Synchronization of the drive units is actually realized. If a specific distribution of the services is specified in accordance with the coordinated regulation, a traction force on the trailer (known, for example, from experiments) is to be expected, which results from the adjusted power output of the vehicle and the power output of the trailer dependent thereon. The relative tractive force analysis unit is set up to determine the current difference in tractive force on the vehicle and trailer by means of sensors and / or calculations. The relative tensile force analysis unit is also set up to act electronically and / or mechanically on the synchronization unit. Synchronization unit and / or relative traction analysis unit may be part of a cross-team control unit.

The at least one relative traction analysis unit may comprise a sensor for detecting the current traction of the vehicle on the trailer. It is preferred that a force sensor, in particular a force measuring bolt, is provided on the trailer. It is particularly preferred that between the vehicle and trailer a (rigid) drawbar is provided and there is at least one sensor attached to detect the current tensile force. The data determined by the sensor are processed by the relative tensile force analysis unit and / or forwarded to the synchronization unit for further processing.

The at least one relative tractive force analysis unit may comprise a computing unit which is set up to determine the current tractive force of the vehicle on the trailer from operating parameters of the vehicle and operating parameters of the trailer. In this case, sensors or maps for determining the current operating parameters of the drive units can be included in order to conclude from the current traction of the vehicle on the trailer. Consequently, it is possible for the relative tractive effort analysis unit to access operating parameters which are generated by a cross-tractor control unit and / or sensors of the drive units.

According to a preferred embodiment of the device, the drive unit of the trailer comprises an electric axle drive, such as an electric motor, and the drive unit of the vehicle, an internal combustion engine, such as a diesel engine and / or at least one electric drive.

According to another embodiment of the device, the drive unit of the trailer comprises a hydraulic axle drive, which z. B. is supplied by the vehicle.

It may be advantageous to implement a device in which both the vehicle and the trailer each have a separate drive unit with at least one inertial sensor for detecting the current lateral acceleration on the vehicle. A transverse acceleration measuring unit may be provided which cooperates with the at least one inertial sensor and an evaluation unit of the steering device of the vehicle. The lateral acceleration measuring unit can determine whether a currently determined lateral acceleration of the vehicle coincides with an expected lateral acceleration according to the current steering situation of the vehicle (within predefined limits). Such a situation can occur if z. B. the vehicle according to the steering device should drive straight, but actually moves laterally, such as in cases when the trailer pushes the vehicle itself. The lateral acceleration measurement unit may be configured to intervene in a synchronization unit that adjusts a coordinated control of at least one of a rotational speed and a torque with respect to the vehicle and the trailer. It is proposed here to carry out the monitoring of the lateral acceleration in addition to the relative tensile force, but this is not absolutely necessary. Rather, this structure or the method described here can also be used independently of the concept of relative tensile force in the carriages described here in order to eliminate the problems mentioned at least partially.

Further details of the device will become apparent from the following explanation of the method. In particular, the explanations on the method can be used here in addition. Likewise, the foregoing explanations on the device may supplement the description of the methods.

1. a) Einstellen einer vorgegebenen Regelstrategie über zumindest die Drehzahl oder das Drehmoment zum synchronisierten Betrieb der beiden Antriebsaggregate bei Fahrzeug und Anhänger;
2. b) Überwachen einer aktuellen Zugkraftdifferenz zwischen Fahrzeug und Anhänger;
3. c) Vergleichen der aktuellen Zugkraftdifferenz mit einem vorgegebenen Grenzwert;
4. d) Automatisches Eingreifen in die Regelstrategie, wenn der Grenzwert erreicht wird.

According to a further aspect, a method for controlling the driving operation of a vehicle with a trailer is proposed, wherein both the vehicle and the trailer each have a separate drive unit. The method can be carried out in particular with the apparatus described above. The method comprises at least the following steps:

1. a) setting a predetermined control strategy on at least the speed or torque for synchronized operation of the two drive units in the vehicle and trailer;
2. b) monitoring a current difference in tractive force between the vehicle and the trailer;
3. c) comparing the current draft difference with a predetermined threshold;
4. d) Automatic intervention in the control strategy when the limit is reached.

The designation of the steps is for the purpose of distinction and subsequent reference and does not mean that they necessarily run one after the other in the order indicated. In particular, steps may overlap one another in time, be initiated simultaneously and / or repeated differently.

In step a) z. B. a synchronization unit (possibly offset in time or needs) basically two setpoints, tensile force or torque and speed, are specified. Which default value is the appropriate depends on the overall system or control concept. If the accelerator pedal value corresponds to a torque or tractive force specification for the vehicle, this value or a part thereof can also simply be specified as the nominal value to a torque control device. Alternatively, the speed of the vehicle rear axle of a torque control device can be specified as a setpoint. This would in principle correspond to a rigid coupling of the electric axle (trailer drive axle) to the tractor.

In step b), in particular at least partially simultaneously or even permanently, the current difference in traction between the vehicle and the trailer is monitored. This can be done sensory or (purely) by calculation. For this purpose, the tensile force exerted by the vehicle on the trailer can be determined.

The result of this monitoring is now in step c) with a (stored) fixed or z. B. performance-dependent variable threshold. Is z. B. according to the predetermined control strategy, the force exerted by the vehicle on the trailer pulling force always greater than the predetermined limit, it can be assumed that a current correct synchronization of both drive units. Then steps a) to c) could be repeated.

However, should it be determined as a result of step c) that the current vehicle and trailer pull difference is at the limit, it can be inferred that there is undesirable traction of the trailer, such as excessive trailer drag on the vehicle. If the current draft difference reaches (or exceeds) the limit value, the control strategy is intervened automatically (and immediately) (step d)). The intervention may include an adaptation of the control strategy, in particular the way in which the (proportionate) performance of the trailer is (significantly) reduced or even switched off. Consequently, step d) can then be maintained until an abort condition and / or an alternative special control strategy can be initiated. Thereafter, it would be possible to start again with step a).

The predetermined limit may be a minimum value. Upon reaching the minimum value can be intervened in the control strategy that the drive effect of the drive unit of the trailer is at least reduced or even turned off. If, for example, a tensile force is observed by the vehicle on the trailer, the limiting value could be a minimum traction force. In this case, the limit could be a positive value or even the "0", because the traction would be negative (thrust), the trailer would push and thus the dangerous situation of pushing away the vehicle can occur. But there are also devices or driving situations possible in which the limit is negative, so even in normal operation a (low) thrust (possibly very short) is tolerated.

In particular, in the context of step b), there is the possibility that the traction difference is measured by measuring the tensile force on a drawbar between the vehicle and trailer and / or determined from operating parameters of the drive unit of the vehicle and operating parameters of the drive unit of the trailer. Possible solutions for detecting and preventing a buckling are accordingly tensile force measurements in the trailer drawbar or a modeling of the vehicle and trailer traction. When measuring the tension in the drawbar, a force measuring bolt or an alternative force measurement can be integrated in the drawbar, which measures the tensile force which the vehicle exerts on the trailer. If this tensile force is less than a minimum value, the moment of the trailer axle can be limited, which reliably prevents a turning or pushing apart of the trailer. If necessary, the vehicle will only deliver the speed or draft setpoints, and the control on the trailer will limit them according to the force measurement.

The tensile force measurement can alternatively or cumulatively be modeled. For example, in an electrically driven axle with a field-oriented control can be calculated based on the electric motor currents, the torque on the engine and at a known ratio also on the axis. A calculation of the vehicle traction can be calculated in a hydrostatic power-split transmission from the oil pressure of the output side hydrostatic. This pressure is used to control the gearbox. For vehicles with other types of transmissions, the vehicle torque may be calculated from the engine load calculated by the engine management, subtracting the ancillary loads and taking into account the ratio. The tensile force or a value equivalent thereto can be determined as the difference between the traction torque of the vehicle and the trailer taking into account the tire size.

It can be provided that the automatic intervention in the control strategy is canceled when the limit is reached again or an external stop signal is given. If, for example, the limit value was initially reached or undershot when the intervention took place, this intervention or the special control strategy initiated therewith can be canceled if the limit value is again reached or exceeded. This can therefore be done automatically. It is cumulatively or alternatively possible for an external termination signal to be provided (for example, the synchronization unit), with which the intervention or the special control strategy initiated therewith is then forcibly canceled. This external cancellation signal can also be manually, z. B. be triggered by the driver. For example, if the vehicle is stuck, so by a deliberate decision of the driver "exceptionally" a given thrust of the trailer are allowed.

In this context, other operating parameters of the vehicle, of the trailer and / or of the team may also be used in order to carry out a review of the current driving situation and / or to initiate a requested termination of the intervention or of the special control strategy (eg. Determining the speed over ground, determination of the lateral acceleration, determination of the driver-side power demand on the vehicle, etc.).

The device and / or method shown here for controlling the drive of a trailer on a vehicle offers, in particular, the following advantages, which prevent dangerous pushing away of the towing vehicle and avoid unwanted and dangerous buckling of the vehicle when cornering and / or a pushing operation. In particular, the proposed control concept for an electrically driven axle on the trailer of a trailer-tractor combination contributes to this.

• 1: schematisch eine Seitenansicht eines Traktors als Teil eines Anhänger-Traktor-Gespanns;
• 2: einen Regelkreis für ein Anhänger-Traktor-Gespann;
• 3: Blockschaltbild einer ersten Ausführungsform eines Regelkreises für ein Gespann;
• 4: Blockschaltbild einer zweiten Ausführungsform eines Regelkreises für ein Gespann; und
• 5: Blockschaltbild einer dritten Ausführungsform eines Regelkreises für ein Gespann.

The invention and the technical environment will be explained in more detail with reference to figures. The same components are identified by the same reference numerals. The illustrations are schematic and not intended to illustrate size relationships. The explanations given with reference to individual details of a figure are extractable and freely combinable with facts from other figures or the above description, unless it is absolutely necessary for a person skilled in the art or such a combination is explicitly prohibited here. Show it:

• 1 Fig. 1 schematically shows a side view of a tractor as part of a trailer-tractor combination;
• 2 : a loop for a trailer-tractor-trailer;
• 3 : Block diagram of a first embodiment of a control circuit for a team;
• 4 : Block diagram of a second embodiment of a control circuit for a team; and
• 5 : Block diagram of a third embodiment of a control loop for a team.

1 shows the basic representation of a vehicle 2 , here's a tractor as a trailer-tractor-trailer. The tractor has two front wheels 7 and two rear wheels 8th on. From the trailer 4 ( 2 ) is broken off the drawbar 16 shown with a rear side on the vehicle 2 arranged coupling 17 engaged. The vehicle pulls 2 when driving in the direction of travel 6 the trailer 4 behind him. The general driving of the vehicle 2 can via a (possibly separate) vehicle control 12 to be influenced. Furthermore, a hydraulic actuator unit 3 comprising a control unit 13 for controlling the hydraulic actuation unit 3 available. The hydraulic actuator 3 can in particular be constructed as follows: The pump 14 Promotes an oil flow to the control valve 15 , which is a (here designed as a front hoist) hoist 43 controls. The hoist 43 An electrohydraulic hoist control (EHR) can be assigned. With 39 is a sensor, eg. B. a force pin, a relative tension measuring device 18 in the drawbar 16 is integrated, and with 40 a computing unit of the relative tension measuring device 18 designated. With 5 is the soil designated.

To 2 rejects the trailer 4 a cargo area 19 or the like, as well as two front wheels 20 (only one wheel shown) and two rear wheels 21 (only one wheel shown). With 22 is the axis of the front wheels 20 (or the illustrated wheel) of the trailer 4 designated.

2 shows a control loop for a team 38 out of vehicle 2 (Tractor) and trailer 4 , The control loop contains components that are the tractor, and components that the trailer 4 assigned. The front wheels 20 of the trailer 4 are about an electric drive unit 23 , z. B. an electric motor, driven. For the control of the drive unit 23 is a control device or synchronization unit 27 of the vehicle 2 provided to a controller area network system for data transmission, CAN bus 29 , connected. The electrical energy for the power unit 23 generates a generator 24 of the vehicle 2 , The synchronization unit 27 is via a user interface 28 adjustable. The speed of the rear axle of the rear wheel 8th is through a tachometer 44 measurable, that to the synchronization unit 27 connected. With 25 is an AC-DC converter (for example, an inverter) and denoted by 26 a DC-AC converter (for example, also an inverter). With 42 is the drive unit of the vehicle, z. B. an internal combustion engine referred to. The drive unit 42 also drives the generator 24 at.

In 3 to 5 is a block diagram of a first, second and third embodiment of a control circuit for the team 38 out 2 shown, which with the synchronization unit 27 can be realized. The control circuit serves the coordinated drive of at least one wheel 20 the axis 22 of the trailer 4 ,

The rule concept after 3 Based on a specification of a target torque to the drive unit 23 based on the specification of a desired speed via a human-machine interface (HMI) such. As an accelerator pedal, here as HMI device 30 shown. The target moment is on the trailer 4 and the vehicle 2 by means of a division circuit 33 divided up. In order to avoid pushing away, as proposed above, a tensile force measurement by means of the relative tensile force analysis unit 18 comprising the sensor 39 and the arithmetic unit 40 and limiting the torque on the trailer 4 by means of nominal torque limitation 36 proposed. This is the case with the tractor or vehicle 2 a performance management 31 or translation management with a tractor-side setpoint torque limitation 32 involving the trailer 4 provided in order to avoid stalling in the limit of engine load, if only the gear torque is taken into account, because the trailer power the drive unit 42 of the vehicle loaded. A so calculated and limited setpoint torque is combined with an actual torque of the drive unit 23 a target-actual comparison 41 fed. A resulting from the target-actual comparison difference is then a torque controller 37 fed, which then adjusts the power output and a corresponding power to the drive unit 23 outputs the optimum torque to the front wheel 21 the axis 22 adjust.

However, the additional force measurement takes over by means of a relative tensile force analysis unit 18 on the trailer 4 this task virtually with. If the drive unit 42 in the push goes and on the gear not enough traction on the ground 5 can transmit, then the tensile force measurement would determine this and the moment of the axis 22 of the trailer 4 limit, as in 4 shown. That would then a stalling of the drive unit 42 prevent.

The control concepts after the 3 and 4 with the setpoint torque limitation 36 for the trailer 4 can be an electronic transmission control and additional measures on the tractor or the vehicle 2 require. For machines with classic manual transmissions, these concepts are less suitable, but these are also found only in the segment below 100 hp.

The control concept according to 5 synchronizes the speed of the electrical axis by the converted speed of the rear axle 45 of the tractor or vehicle 2 , For this purpose, a measuring point 34 Traktorachsdrehzahl or a tractor speed are integrated and this speed or speed, together with the wheel circumference to a speed or speed controller 35 of the trailer 4 be reported and after the already described Sollmomentlimitierung 36 to avoid pushing away the torque controller 37 be supplied. This can also be retrofitted. The speed is available on most modern transmissions or calculated from the engine speed and the ratio. These simple concepts with traction measurement on the drawbar 16 of the trailer 4 but cause the trailer 4 when the vehicle is stuck 2 no longer provides support and the team 38 can no longer free, although physically due to the driven axle 22 of the trailer 4 it is possible. As a solution to this could be the Sollmomentlimitierung 36 the axis 22 be deliberately disabled by the driver if vehicle 2 in a furrow and can not be pushed away. Thus, a "release" of the team would be 38 possibly under control of the driver. This deactivation of the target torque limitation 36 but should be stopped immediately when the vehicle 2 driving again, what then either by the driver or an automated speed-over-ground measurement or alternatively an acceleration measurement with inertial sensors 46 can be realized.

When using inertial sensors 46 on the vehicle 2 Similar to an ESP intervention, the traction torque of the trailer 4 limited if the vehicle 2 is pushed away laterally, that is, the movement of the tractor does not match the steering angle. If the vehicle 2 is not pushed away sideways, z. B. because it is in a furrow or an extended path, so would the electrical axis 22 the trailer 4 push on and could prevent a stall. The intervention here would be the speed or tension setpoint values on the vehicle 2 limited before going to the trailer 4 be transferred if the vehicle 2 rotates. This then requires the installation of inertial sensors 46 on the vehicle 2 and the reading of the steering angle on the vehicle 2 ,

The invention has been explained in more detail on the example of a tractor and an electric drive unit on the trailer, without this being limited thereto.

LIST OF REFERENCE NUMBERS

1

contraption

2

vehicle

3

hydraulic actuator

4

pendant

5

ground

6

direction of travel

7

front

8th

rear wheel

9

motor control

10

transmission control

11

data-conducting connection

12

vehicle control

13

control unit

14

pump

15

control valve

16

shaft

17

clutch

18

Relatively Traction analysis unit

19

load area

20

front

21

rear wheel

22

axis

23

Drive unit of the trailer

24

generator

25

AC-DC converter

26

DC-AC converter

27

synchronization unit

28

User Interphase

29

CAN bus

30

HMI device

31

performance management

32

vehicle-side setpoint torque limitation

33

Distribution circuit (torque distribution vehicle trailer)

34

Measuring point of the vehicle axle speed or vehicle speed

35

cruise control

36

Target torque limit

37

torque controller

38

team

39

sensor

40

computer unit

41

Target-performance comparison

42

Drive unit of the vehicle

43

hoist

44

Speed measuring element

45

rear axle

46

inertial sensor

Claims (12)

Device (1) for controlling the driving operation of a vehicle (2) with a trailer (4), wherein both the vehicle (2) and the trailer (4) each have a separate drive unit (23, 42) comprising at least - At least one synchronization unit (27), which adjusts a coordinated control of at least one rotational speed or torque with respect to the vehicle (2) and trailer (4), and - At least one relative tensile force analysis unit (18), set up to detect the current traction difference occurring on the vehicle (2) and trailer (4) occurring during driving and to intervene in the synchronization unit (27). Device (1) according to Claim 1 wherein the at least one relative tensile force analysis unit (18) comprises at least one sensor (39) for detecting the current tractive force of the vehicle (2) on the trailer (4). Device (1) according to Claim 2 , between vehicle (2) and trailer (4) a drawbar (16) is provided and at least one sensor (39) for detecting the current tensile force is mounted there. Device (1) according to any one of the preceding claims, wherein the at least one relative tensile force analysis unit (18) comprises a computing unit (40) which is arranged from operating parameters of the vehicle (2) and operating parameters of the trailer (4) the current traction of the vehicle (2) on the trailer (4) to determine. Device (1) according to one of the preceding claims, wherein the drive unit (23) of the trailer (4) comprises an electric axle drive and the drive unit (42) of the vehicle (2) comprises an internal combustion engine. Device (1) according to one of the preceding claims, wherein further an inertial sensor (46) for detecting the current lateral acceleration on the vehicle (2) is provided. Method for controlling the driving operation of a vehicle (2) with a trailer (4), wherein both the vehicle (2) and the trailer (4) each have a separate drive unit (23, 42) comprising at least the following steps: a) setting a predetermined control strategy on at least the speed or the torque for synchronized operation of the two drive units (23, 42) in the vehicle (2) and trailer (4); b) monitoring a current difference in traction between the vehicle (2) and trailer (4); c) comparing the current draft difference with a predetermined threshold; d) Automatic intervention in the control strategy when the limit is reached. Method according to Claim 7 in which the predetermined limit value is a minimum value and, when the minimum value is reached, intervention is made in the control strategy in such a way that the drive effect of the drive unit of the trailer is at least reduced. Method according to Claim 7 or 8th in which the traction force difference is measured by measuring the tensile force on a drawbar (16) between the vehicle (2) and trailer (4). Method according to one of Claims 7 to 9 in which traction difference is determined from operating parameters of the drive unit (42) of the vehicle (2) and from operating parameters of the drive unit (23) of the trailer (4). Method according to one of Claims 7 to 10 , in which the automatic intervention in the control strategy is canceled when the limit is reached again or an external stop signal is given. Method according to one of Claims 7 to 11 in which step d) is carried out if it is determined that there is an atypical lateral acceleration relative to the current steering angle of the vehicle (2).

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