Agricultural work vehicle and control method

Abstract

A working vehicle (2) for use in agriculture is configured for mounting a laterally protruding implement on the vehicle front or vehicle rear. The vehicle has an electronically controllable drive motor (4), an electronically controllable brake system (6), a sensor arrangement (8) for measuring rotational movements or rotational oscillations about at least one of three reference axes, and an electronic control device (10) for evaluating sensor data and for activating the drive motor (4) or the brake system (6). A data storage (50) stores threshold values for the sensor data. The control device determines characteristic values for the respective rotational movement or rotational oscillation and decides whether a reduction in travel speed is required in view of the threshold values. If true, the travel speed is reduced until the characteristic value reaches or falls below the threshold value.

Claims

1. A working vehicle (2) for use in agriculture, having a vehicle front and a vehicle rear and being configured for mounting a laterally protruding implement on at least one of the vehicle front and vehicle rear, the working vehicle comprising: an electronically controllable drive motor (4), an electronically controllable brake system (6), a sensor arrangement (8) for measuring rotational movements or rotational oscillations about at least one reference axis (40, 44, 48) of the working vehicle (2), and an electronic control device (10) for evaluating sensor data of the sensor arrangement (8) and for activating a drive motor (4) or a brake system (6) of the work vehicle, wherein the sensor arrangement (8) comprises at least one sensor (38a, 38b) for measuring the rotational movements or the rotational oscillations about a transverse axis (40) of the working vehicle (2), at least one sensor (42a, 42b) for measuring rotational movements or rotational oscillations about a longitudinal axis (44) of the working vehicle (2), and at least one sensor (46a, 46b) for measuring rotational movements or rotational oscillations about a vertical axis (48) of the working vehicle (2), wherein an electronic data storage (50) is assigned to the electronic control device (10) and stores threshold values (ω.sub.N_max, ω.sub.R_max, ω.sub.G_max) for the rotational movements or rotational oscillations about the transverse, longitudinal, and vertical axes (40, 44, 48), wherein the electronic control device (10) is programmed to determine, from the measured values of rotational movements or rotational oscillations detected by the sensors, characteristic values (ω.sub.N, ω.sub.R, ω.sub.G) of the rotational movements or rotational oscillations about the transverse, longitudinal, and vertical axes (40, 44, 48), respectively, wherein, as a function of at least one of the characteristic values (ω.sub.N, ω.sub.R, ω.sub.G) and the assigned threshold value (ω.sub.N_max, ω.sub.R_max, ω.sub.G_max), the electronic control device is programmed to decide whether a reduction in travel speed (V.sub.F) is required and that upon an affirmative decision, the electronic control device is programmed to activate the drive motor (4) or the brake system (6) such that the travel speed (V.sub.F) is reduced until the characteristic value (ω.sub.N, ω.sub.R, ω.sub.G) reaches or falls below the relevant threshold value (ω.sub.N_max, ω.sub.R_max, ω.sub.G_max) by activating the drive motor to reduce the travel speed by reducing a torque output from the drive motor or reducing a rotational speed of the drive motor.

2. The working vehicle as claimed in claim 1, wherein the electronic control device (10) is configured to automatically determine the threshold values (ω.sub.N_max, ω.sub.R_max, ω.sub.G_max) using the measured values, to automatically perform an identification of a fitted implement, and to store the threshold values and the identification in the electronic data storage (50).

3. The working vehicle as claimed in claim 1, further comprising an input device (52) for a manual input of an identifier of a fitted implement, a nature of a terrain to be traveled and the threshold values (ω.sub.N_max, ω.sub.R_max, ω.sub.G_max) for storing the identifier, the nature of the terrain, and the threshold values in the electronic data storage (50).

4. The working vehicle as claimed in claim 1, wherein the sensor arrangement (48) is a component of an electronic stability control module (36) for measuring the rotational movements or rotational oscillations of the working vehicle (2).

5. The working vehicle as claimed in claim 1, wherein the electronic control device (10) is integrated in a speed control system (54).

6. The working vehicle as claimed in claim 1, wherein the travel speed is reduced as a continuous reduction of the travel speed (V.sub.F) or as a stepwise reduction of the travel speed until the characteristic value (ω.sub.N, ω.sub.R, ω.sub.G) of the rotational movement or of the rotational oscillation has reached or fallen below the assigned threshold value (ω.sub.N_max, ω.sub.R_max, ω.sub.G_max).

7. The working vehicle as claimed in claim 1, wherein the characteristic value of a respective measured rotational oscillation is determined as an oscillation amplitude or as an RMS value of the measured rotational oscillation, and wherein the predetermined threshold value is a threshold oscillation amplitude or an RMS threshold value.

8. A method for controlling a working vehicle (2) for use in agriculture, having a vehicle front and a vehicle rear and being configured for mounting a laterally protruding implement on at least one of the vehicle front and vehicle rear, the working vehicle having an electronically controllable drive motor (4), an electronically controllable brake system (6), a sensor arrangement (8) for detecting rotational movements or rotational oscillations about at least one of three reference axes (40, 44, 48) of the working vehicle (2), and an electronic control device (10) for evaluating sensor data of the sensor arrangement (8) and for activating a drive motor (4) or a brake system (6), wherein the rotational movements or the rotational oscillations are measured by a sensor of the sensor arrangement, the method comprising the following steps: determining a characteristic value (ω.sub.N, ω.sub.R, ω.sub.G) for each of the measured rotational movements or rotational oscillations, comparing each characteristic value (ω.sub.N, ω.sub.R, ω.sub.G) with a respective predetermined threshold value (ω.sub.N_max, ω.sub.R_max, ω.sub.G_max), and upon determining that the characteristic value (ω.sub.N, ω.sub.R, ω.sub.G) exceeds the threshold value (ω.sub.N_max, ω.sub.R_max, ω.sub.G_max), reducing a travel speed (V.sub.F) of the working vehicle (2) until the characteristic value (ω.sub.N, ω.sub.R, ω.sub.G) has reached or fallen below the threshold value (ω.sub.N_max, ω.sub.R_max, ω.sub.G_max); wherein the step of reducing the travel speed is performed as a continuous reduction of the travel speed (V.sub.F) or as a stepwise reduction of the travel speed until the characteristic value (ω.sub.N, ω.sub.R, ω.sub.G) of the rotational movement or of the rotational oscillation has reached or fallen below the assigned threshold value (ω.sub.N_max, ω.sub.R_max, ω.sub.G_max).

9. The method as claimed in claim 8, wherein the characteristic value of a respective measured rotational movement is determined as rotational velocity (ω.sub.N, ω.sub.R, ω.sub.G) or as a rotational acceleration of the measured rotational movement, and wherein the compared predetermined threshold value is a threshold rotational velocity (ω.sub.N_max, ω.sub.R_max, ω.sub.G_max) or a threshold rotational acceleration.

10. The method as claimed in claim 8, wherein the characteristic value of a respective measured rotational oscillation is determined as an oscillation amplitude or as an RMS value of the measured rotational oscillation, and wherein the predetermined threshold value is a threshold oscillation amplitude or an RMS threshold value.

11. The method as claimed in claim 8, further comprising the steps of: low-pass filtering the sensor signals for the measured rotational movement the measured rotational oscillation, and evaluating the low-passed filtered sensor signals in the electronic control device (10).

12. The method as claimed claim 8, wherein the step of reducing the travel speed is performed as a continuous reduction of the travel speed (V.sub.F) until the characteristic value (ω.sub.N, ω.sub.R, ω.sub.G) of the rotational movement or of the rotational oscillation has reached or fallen below the assigned threshold value (ω.sub.N_max, ω.sub.R_max, ω.sub.G_max).

13. The method as claimed claim 8, wherein the step of reducing the travel speed is performed as a stepwise reduction of the travel speed (V.sub.F) until the characteristic value (ω.sub.N, ω.sub.R, ω.sub.G) of the rotational movement or of the rotational oscillation has reached or fallen below the assigned threshold value (ω.sub.N_max, ω.sub.R_max, ω.sub.G_max).

14. The method as claimed in one of claims 8, wherein the step of reducing the travel speed is performed by activating the brake system (6) including actuating service brakes of at least one brake circuit of the brake system (6).

15. A method for controlling a working vehicle (2) for use in agriculture, having a vehicle front and a vehicle rear and being configured for mounting a laterally protruding implement on at least one of the vehicle front and vehicle rear, the working vehicle having an electronically controllable drive motor (4), an electronically controllable brake system (6), a sensor arrangement (8) for detecting rotational movements or rotational oscillations about at least one of three reference axes (40, 44, 48) of the working vehicle (2), and an electronic control device (10) for evaluating sensor data of the sensor arrangement (8) and for activating a drive motor (4) or a brake system (6), wherein the rotational movements or the rotational oscillations are measured by a sensor of the sensor arrangement, the method comprising the following steps: determining a characteristic value (ω.sub.N, ω.sub.R, ω.sub.G) for each of the measured rotational movements or rotational oscillations, comparing each characteristic value (ω.sub.N, ω.sub.R, ω.sub.G) with a respective predetermined threshold value (ω.sub.N_max, ω.sub.R_max, ω.sub.G_max), and upon determining that the characteristic value (ω.sub.N, ω.sub.R, ω.sub.G) exceeds the threshold value (ω.sub.N_max, ω.sub.R_max, ω.sub.G_max), reducing a travel speed (V.sub.F) of the working vehicle (2) until the characteristic value (ω.sub.N, ω.sub.R, ω.sub.G) has reached or fallen below the threshold value (ω.sub.N_max, ω.sub.R_max, ω.sub.G_max); wherein the step of reducing the travel speed is performed by reducing a torque output from the drive motor (4) or by reducing a rotational speed of the drive motor (4).

16. The method as claimed in claim 15, wherein the characteristic value of a respective measured rotational movement is determined as rotational velocity (ω.sub.N, ω.sub.R, ω.sub.G) or as a rotational acceleration of the measured rotational movement, and wherein the compared predetermined threshold value is a threshold rotational velocity (ω.sub.N_max, ω.sub.R_max, ω.sub.G_max) or a threshold rotational acceleration.

17. The method as claimed in claim 15, wherein the characteristic value of a respective measured rotational oscillation is determined as an oscillation amplitude or as an RMS value of the measured rotational oscillation, and wherein the predetermined threshold value is a threshold oscillation amplitude or an RMS threshold value.

18. The method as claimed in claim 15, further comprising the steps of: low-pass filtering the sensor signals for the measured rotational movement the measured rotational oscillation, and evaluating the low-passed filtered sensor signals in the electronic control device (10).

19. The method as claimed claim 15, wherein the step of reducing the travel speed is performed as a continuous reduction of the travel speed (V.sub.F) until the characteristic value (ω.sub.N, ω.sub.R, ω.sub.G) of the rotational movement or of the rotational oscillation has reached or fallen below the assigned threshold value (ω.sub.N_max, ω.sub.R_max, ω.sub.G_max).

20. The method as claimed claim 15, wherein the step of reducing the travel speed is performed as a stepwise reduction of the travel speed (V.sub.F) until the characteristic value (ω.sub.N, ω.sub.R, ω.sub.G) of the rotational movement or of the rotational oscillation has reached or fallen below the assigned threshold value (ω.sub.N_max, ω.sub.R_max, ω.sub.G_max).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the drawings,

(2) FIG. 1 shows a working vehicle having a control device according to the invention in a schematic view, and

(3) FIG. 2 shows a control method according to the invention in a schematic flow diagram, which may be operated in the control device according to FIG. 1.

DETAILED DESCRIPTION OF THE DRAWINGS

(4) The working vehicle 2 shown schematically in FIG. 1 has an electronically controllable drive motor 4, an electronically controllable brake system 6, a sensor arrangement 8 for detecting rotational movements or rotational oscillations about at least one reference axis and an electronic control device 10 for evaluating sensor data of the sensor arrangement 8 and for activating the drive motor 4 or the brake system 6. The drive motor 4 in the present case is configured by way of example as an internal combustion engine and regarding its power output and its rotational speed may be controlled by means of an electronic engine control device 12.

(5) The brake system 6, shown in FIG. 1 only in part and highly simplified, is configured in the present case by way of example as a compressed air brake system and comprises an electronic brake control device 14, a foot brake valve, 16, a changeover valve 18, a relay valve 20 and two wheel brake cylinders 22a, 22b which are arranged on the wheel brakes of the vehicle wheels 26a, 26b of a vehicle axle 24.

(6) The compressed air provided by a compressed air source 28 is present in a supply pressure line 30 which is guided to a supply pressure inlet of the relay valve 20. Additionally a brake control line 32, guided to a control pressure inlet of the relay valve 20, is able to be supplied with a control pressure which lies between the supply pressure and the ambient pressure by an actuation of the foot brake valve 16. The control pressure is converted in the relay valve 20 into a corresponding brake pressure which prevails in an axle brake line 34 connected to the brake pressure outlet of the relay valve 20 and guided to the wheel brake cylinders 22a, 22b of the vehicle axle 24.

(7) The changeover valve 18 is configured as a 3/2-way magnetic switching valve which is activatable by the brake control device 14 and arranged in the brake control line 32. When switching the changeover valve 18, the control pressure inlet of the relay valve 20 is supplied with a supply pressure independently of the current adjusted position of the foot brake valve 16, so that the wheel brake cylinders 22a, 22b of the vehicle axle 14 are then actuated and the working vehicle 2 is braked.

(8) The sensor arrangement 18, which in the present case by way of example is a component of an ESC (Electronic Stability Control) module 36, has two sensors 38a, 38b for measuring a rotational movement or a rotational oscillation about a transverse axis 40 (i.e. for measuring a pitch movement or pitch oscillation of the working vehicle 2), two sensors 42a, 42b for detecting a rotational movement or a rotational oscillation about a longitudinal axis 44 (i.e. for measuring a roll movement or roll oscillation of the working vehicle 2), as well as two sensors 46a, 46b for measuring a rotational movement or rotational oscillation about the vertical axis 48 of the working vehicle 2 (i.e. for measuring a yaw movement or yaw oscillation).

(9) The control device 10 is connected in each case via at least one electrical sensor line 56 to the sensor arrangement 8, via at least one first control line 58 to the engine control device 12 of the drive motor 4 and via at least one second control line 60 to the brake control device 14 of the brake system 6. The brake control device 14 is connected via a third control line 64 to the changeover valve 18.

(10) An electronic data storage 50 is assigned to the control device 10, threshold values for a rotational movement or a rotational oscillation about the transverse axis 40, about the longitudinal axis 44 and about the vertical axis 48 of the working vehicle 2 being stored therein.

(11) The electronic control device 10 is configured to determine from the measured rotational movements or rotational oscillations characteristic values for the respective rotational movement or rotational oscillation about the transverse axis 40, about the longitudinal axis 44 and about the vertical axis 48 of the working vehicle 2 and, as a function of at least one specific characteristic value thereof for a measured rotational movement or rotational oscillation and the assigned threshold value, to decide whether a reduction in the travel speed is required or not.

(12) In the case of a positive decision, the drive motor 4 or the brake system 6 is activated by the control device 10 such that the travel speed of the working vehicle 2 is reduced by the characteristic value until the relevant threshold value is reached or fallen below. The reduction in the travel speed of the working vehicle 2 is carried out by reducing the torque output from the drive motor 4 or by reducing the rotational speed or by venting the wheel brake cylinders 22a, 22b of the vehicle axle 24 so that these have a braking effect.

(13) The threshold values for a rotational movement or a rotational oscillation about the transverse axis 40, about the longitudinal axis 44 and about the vertical axis 48 of the working vehicle 2 may be determined automatically using measured values detected by sensor and, by an identification of the implement fitted on the working vehicle 2, may be stored as a characteristic value in the data storage 50.

(14) Additionally, an input device 52 which is connected to the data storage 50 via a data line 62 is also present in the example shown in FIG. 1. On the input device 52 a driver may identify the implement fitted on the working vehicle 2 by means of an identifier which has been input. Moreover, the driver may input manually the nature of the terrain to be traveled over and the threshold values for a rotational movement or rotational oscillation about the transverse axis 40, about the longitudinal axis 44 and about the vertical axis 48 of the working vehicle 2 and store these in the electronic data storage 50. The control device 10 and the data storage 50 are integrated in the present case by way of example in a speed control system 54 of the working vehicle 2.

(15) The control sequence for measuring by sensor and damping rotational movements or rotational oscillations of the working vehicle 2 about the transverse axis 40, about the longitudinal axis 44 and about the vertical axis 48 thereof is described by way of example hereinafter with reference to the flow diagram illustrated in FIG. 2.

(16) Initially after the start S0 of the method, in method step S1 by evaluating the sensor signals of the sensors 38a, 38b rotational movements or rotational oscillations of the working vehicle 2 about the transverse axis 40 of the working vehicle 2 are measured and in the method step S2 characteristic values relevant thereto are determined therefrom, in this case by way of example a rotational velocity about the transverse axis 40, i.e. a pitch velocity ω.sub.N.

(17) In the following method step S3 it is monitored whether the current pitch velocity ω.sub.N exceeds a predetermined threshold value for the pitch velocity ω.sub.N_max. If this is relevant, a branching occurs to the method step S10, in which the travel speed v.sub.F of the working vehicle 2 is reduced by a fixed speed difference Δv. This is carried out in this case by a reduction in the torque output from the drive motor 4 or by an actuation of the wheel brakes on the vehicle axle 24. Then a branching occurs back to before the method step S1.

(18) In the case of a negative result of the monitoring in the method step S3, i.e. when the current pitch velocity ω.sub.N does not exceed the predetermined threshold value for the pitch velocity ω.sub.N_max, in method step S4 by evaluating the sensor signals of the sensors 42a, 42b rotational movements or rotational oscillations of the working vehicle 2 about the longitudinal axis 44 thereof are measured, and characteristic values in a method step S5, in this case by way of example a rotational velocity about the longitudinal axis 44 of the working vehicle 2, i.e. a roll velocity ω.sub.R, are determined therefrom. In the following method step S6, it is monitored whether the current roll velocity ω.sub.R exceeds a predetermined threshold value for the roll velocity ω.sub.R_max. If this is relevant, a branching occurs to the method step S10 in which the travel speed V.sub.F of the working vehicle 2 as already described is reduced by the fixed speed difference Δv. Then a branching occurs back to before the method step S1.

(19) In the case of a negative result of the monitoring in the method step S6, i.e. when the current roll velocity ω.sub.R does not exceed the predetermined threshold value for the roll velocity ω.sub.R_max, in a method step S7 by evaluating the sensor signals of the sensors 46a, 46b rotational movements or rotational oscillations of the working vehicle 2 about the vertical axis 48 thereof are measured and characteristic values in a method step S8, in this case by way of example a rotational velocity about the vertical axis 48 of the working vehicle 2, i.e. a yaw velocity ω.sub.G, are determined therefrom. In the following method step S9, it is monitored whether the current yaw velocity we exceeds a predetermined threshold value for the yaw velocity ω.sub.G_max. If this is relevant, a branching occurs to the method step S10, in which the travel speed V.sub.F of the working vehicle 2 is reduced by the fixed speed difference Δv as described. Then a branching occurs back to the method step S1. In the case of a negative result of the monitoring in method step S9, i.e. when the current yaw velocity we does not exceed the predetermined threshold value for the yaw velocity ω.sub.G_max, a branching occurs directly back to the method step S1.

(20) The control method is activated at the start of the operational travel of the working vehicle 2 having a fitted implement, and performed permanently or at a fixed time interval during operational travel.

(21) While the above description constitutes the preferred embodiments of the present invention, the invention is susceptible to modification, variation and change without departing from the proper scope and fair meaning of the accompanying claims.

LIST OF REFERENCE NUMERALS (PART OF THE DESCRIPTION)

(22) 2 Working vehicle

(23) 4 Drive motor, internal combustion engine

(24) 6 Brake system, compressed air brake system

(25) 8 Sensor arrangement

(26) 10 Electronic control device

(27) 12 Engine control device

(28) 14 Brake control device

(29) 16 Foot brake valve

(30) 18 Changeover valve

(31) 20 Relay valve

(32) 22a, 22b Wheel brake cylinder

(33) 24 Vehicle axle

(34) 26a, 26b Vehicle wheel

(35) 28 Compressed air source

(36) 30 Supply pressure line

(37) 32 Brake control line

(38) 34 Axle brake line

(39) 36 ESC-Module (Electronic Stability Control Module)

(40) 38a, 38b Two sensors on transverse axis of working vehicle

(41) 40 Transverse axis of working vehicle, first reference axis

(42) 42a, 42b Two sensors on longitudinal axis of working vehicle

(43) 44 Longitudinal axis of working vehicle, second reference axis

(44) 46a, 46b Two sensors on vertical axis of working vehicle

(45) 48 Vertical axis of working vehicle, third reference axis

(46) 50 Data storage

(47) 52 Input device

(48) 54 Speed control system

(49) 56 Sensor line

(50) 58 First control line

(51) 60 Second control line

(52) 62 Data line

(53) 64 Third control line

(54) ESC Electronic Stability Control, electronic driving stabilization

(55) RMS Root Mean Square

(56) S0-S10 Method steps

(57) v.sub.F Travel speed

(58) Δv Speed difference

(59) ω.sub.G Yaw velocity

(60) ω.sub.G_max Threshold value for yaw velocity

(61) ω.sub.N Pitch velocity

(62) ω.sub.N_max Threshold value for pitch velocity

(63) ω.sub.R Roll velocity

(64) ω.sub.R_max Threshold value for roll velocity