Truck

• US 20080264709A1
• Filed: 04/15/2008
• Published: 10/30/2008
• Est. Priority Date: 04/16/2007
• Status: Active Grant

• Current Assignee: Liebherr-Components Biberach Gmbh (Liebherr-International AG)
• Original Assignee: Liebherr-Werk Biberach GmbH (Liebherr-International AG)
• Inventors: Resch, Juergen, Fenker, Oliver
• Granted Patent: US 7,942,228 B2
• Time in Patent Office: Days
• US Class Current: 180/197
• CPC Class Codes: B60K 23/0808 for varying torque distribution between driven axles, e.g. by transfer clutch
• CPC Class Codes: B60K 28/16 responsive to, or preventing, skidding of wheels brake control systems for vehicle drive stability B60T8/1755; arrangements responsive to a speed condition for adjusting wheel braking force B60T8/32; control of vehicle driving stability otherwise than by controlling the propulsion unit only B60W30/02; preventing wheel slippage by reducing power in rail vehicles B61C15/00
• CPC Class Codes: B60K 7/0007 the motor being electric
• CPC Class Codes: B60L 15/2036 Electric differentials, e.g. for supporting steering vehicles
• CPC Class Codes: B60L 2240/24 Steering angle
• CPC Class Codes: B60L 2240/461 Speed
• CPC Class Codes: B60L 2240/465 Slip
• CPC Class Codes: B60L 3/102 of individual wheels
• CPC Class Codes: B60T 2201/06 Hill holder; Start aid systems on inclined road
• CPC Class Codes: B60T 2270/303 Stability control with active acceleration
• CPC Class Codes: B60T 2270/613 ESP features related thereto
• CPC Class Codes: B60T 7/122 for locking of reverse movement
• CPC Class Codes: B60T 8/1755 Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve road vehicle drive control systems for control of driving stability otherwise than by controlling a particular sub-unit B60W30/02
• CPC Class Codes: B60W 2050/001 Proportional integral [PI] controller
• CPC Class Codes: B60W 2520/28 Wheel speed
• CPC Class Codes: B60W 2540/18 Steering angle
• CPC Class Codes: B60W 2720/28 Wheel speed
• CPC Class Codes: B60W 2720/30 Wheel torque
• CPC Class Codes: B60W 30/02 Control of vehicle driving stability
• CPC Class Codes: B60W 30/18118 Hill holding
• CPC Class Codes: B60W 30/18172 : Preventing, or responsive to skidding of wheels
• CPC Class Codes: B60W 40/101 : Side slip angle of tyre
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility

Abstract

The present invention relates to a truck, in particular to a bulk goods dump truck of the so-called large dump truck type, having a chassis with wheels of which a plurality of wheels each have a single wheel drive and having a control device for the control of the speed and/or of the torque of the single wheel drives. In order also to be able to operate the vehicle in the optimal wheel slip range under difficult ground conditions, provision is made for the control device to have a separate controller train for each single wheel drive and to divide a desired torque set by the operator to the controller trains, with each controller train having a differential controller which corrects the divided desired torque in dependence on a steering angle and provides a correspondingly corrected desired torque as well as having a wheel slip controller which corrects the divided desired torque or the desired torque value corrected by the differential controller in dependence on its wheel slip and provides a corresponding single wheel drive desired torque value. A simple expansion to more than two drives is possible by the provision of separate control trains. In this connection, the desired torque is first divided to the single drives by the operator, then corrected by the differential control and the wheel slip control and finally transmitted to a frequency inverter as a desired torque.

Claims

1. A truck, in particular a large dump truck for the transport of mine overburden, raw materials and/or natural resources, having a chassis (2) with wheels (3) of which a plurality of wheels (3) each have a single wheel drive (4) and having a control device (5) for the control of the speed and/or of the torque of the single wheel drives (4), wherein the control device (5) has a separate control train (6, 7) for each single wheel drive (4) and divides a desired torque (Msoll) set by the operator to the control trains (6, 7), with each control train (6, 7) having a differential controller (8) for the correction of the divided desired torque (Msoll) in dependence on a steering angle (α

) and provision of a correspondingly corrected desired torque (M_res) as well as a wheel slip controller (9) for the correction of the divided desired torque and/or of the corrected desired torque (M_res) in dependence on a wheel slip and provision of a single wheel drive desired (M_soll*).

2. A truck in accordance with claim 1, wherein the wheel slip controller (9) has a speed controller (10) for the determination of a desired torque in dependence on a difference of an actual wheel speed (n) and a desired wheel speed (n*).

3. A truck in accordance with claim 2, wherein the speed controller (10) is made as a PI controller.

4. A truck in accordance with claim 2, wherein a desired wheel speed sensor (11) for the determination of the desired wheel speed (n*) in dependence on a desired wheel value and/or a desired vehicle acceleration value is connected before the speed controller (10).

5. A truck in accordance with claim 4, wherein the desired wheel speed sensor (11) determines the desired wheel speed (n*) by integration of the desired wheel value and/or the desired vehicle acceleration value (a*) over time.

6. A truck in accordance with claim 4, wherein a desired acceleration value sensor (12) for the determination of a desired acceleration value (a*) is connected before the desired wheel speed sensor (11).

7. A truck in accordance with claim 6, wherein the desired acceleration value sensor (12) has an acceleration adaptation stage (13) which corrects an acceleration stroke value in dependence on an actual vehicle acceleration.

8. A truck in accordance with claim 7, wherein the acceleration adaptation stage (13) determines the vehicle acceleration from a wheel set acceleration and/or from the difference of a plurality of wheel speeds (n(t1), n(t2) . . . ) stored at different times.

9. A truck in accordance with claim 8, wherein the adapted acceleration value (a_ad) determined from the wheel set acceleration and/or from the difference of the wheel speeds stored at different times is corrected in dependence on previously carried out desired acceleration value adaptations.

10. A truck in accordance with claim 9, wherein the adapted acceleration value (a_ad) is determined with reference to the following relationship

11. A truck in accordance with claim 1, wherein the wheel slip controller (9) has a gradient limiter (14) for the limitation of the desired torque (M_soll*) in dependence on the gradient of the time course of the desired torque.

12. A truck in accordance with claim 1, wherein the wheel slip controller (9) works independently of speed signals of non-driven wheels and/or works solely in dependence on speed signals of the driven wheels (3) to be controlled.

13. A truck in accordance with claim 1, wherein the wheel slip controller (9) works independently of information on the current vehicle weight and independently of information on the current road gradient.

14. A truck in accordance with claim 1, wherein the differential controller (8) has a speed controller (15) for the determination of the corrected desired torque (M_res) in dependence on a difference of the actual wheel speed (n) and a desired wheel speed (n_HR, n_HL).

15. A truck in accordance with claim 14, wherein the speed controller (15) is a P controller.

16. A truck in accordance with claim 15, wherein the P factor of the speed controller (15) is coupled proportionally to the desired torque value and the corrected desired torque (M_res) is determined using the following relationship

17. A truck in accordance with claim 1, wherein the speed controller (15) has a desired speed sensor (16) for the determination of the desired wheel speed (n_HR, n_HL) in dependence on the current wheel speeds of a plurality of wheels, on the chassis geometry, in particular the chassis track width (l) and the center distance (d), and on the steering angle (α

).

18. A truck in accordance with claim 17, wherein the desired speed sensor (16) transforms the current wheel speeds in each case at a point (p0) between the corresponding wheels, averages the transformed wheel speeds and determines the desired speeds of the respective wheels from the meaned, transformed wheel speeds.

19. A truck in accordance with claim 1, wherein the different controller (8) has a ramp stage for the determination of the desired wheel speed with reference to an acceleration ramp for the change in the desired wheel speed.

26. A truck in accordance with claim 1, wherein it is designed free of mechanical differentials between the single wheel drives.

20. A truck, in particular a large dump truck for the transport of mine overburden, raw materials and/or natural resources, having a chassis (2) with wheels (3) of which a plurality of wheels (3) each have a single wheel drive (4) and having a control device (5) for the control of the speed and/or of the torque of the single wheel drives (4), wherein the control device (5) has a stop controller (18) to stop the vehicle in the stationary state on the presence of a stop signal set by the driver, the stop controller (18) has a speed controller (19) which provides a stop torque signal in dependence of the difference of the actual wheel speed (n) from the wanted desired speed=0 with which at least one of the single wheel drives (4) is controlled.

21. A truck in accordance with claim 20, wherein the speed controller (19) is a precontrolled PI controller.

22. A truck in accordance with claim 20, wherein the actual wheel speed is detected by means of an encoder (20) having a plurality of tracks, with which a signal evaluator (21) is associated which provides flank-dependent simple evaluations of the signals of the several tracks of the encoder (20) carried out in parallel.

23. A truck, in particular a large dump truck for the transport of mine overburden, raw materials and/or natural resources, having a chassis (2) with wheels (3) of which a plurality of wheels (3) each have a single wheel drive (4) and having a control device (5) for the control of the speed and/or of the torque of the single wheel drives (4), wherein the control device (5) has a backward stop controller (22) for the prevention of an unwanted backward rolling which has a speed controller (23) which changes over and which provides a desired forward torque signal of sufficient magnitude on the occurrence of a negative actual wheel speed.

24. A truck in accordance with claim 23, wherein the speed controller (23) stores the desired torque required for the reaching of the speed=0 on a non-actuation of an operator pedal, actuates a mechanical brake and opens the mechanical brake again as soon as a desired torque (M_Soll*) provided at a demand of the operator exceeds the stored desired torque value.

25. A truck in accordance with claim 23, wherein the speed controller (23) provides a desired forward torque of sufficient magnitude on the setting of a desired torque by the machine operator and on the occurrence of a nevertheless negative actual wheel speed for so long until the desired torque (M_Soll*) determined on the basis of the demand of the operator is larger than the desired forward torque provided by the speed controller (23).

27. A method for the control of the drive of a truck which has a plurality of wheels driven by single wheel drives, with the speed and/or the torque of the single wheel drives being controlled by a control device, wherein the desired torque set by an operator is divided onto a plurality of separate controller trains for each single wheel drive, with the divided desired torque being corrected in each control train by means of a differential control in dependence on a steering angle and the divided desired torque and/or the desired torque corrected by the differential control being corrected by a wheel slip control in dependence on a wheel slip.