TRACTOR CONTROL SYSTEM

• US 20140343802A1
• Filed: 06/26/2012
• Published: 11/20/2014
• Est. Priority Date: 07/22/2011
• Status: Active Grant

• Current Assignee: AGCO International GmbH (AGCO International Holdings BV)
• Original Assignee: AGCO International GmbH (AGCO International Holdings BV)
• Inventors: Pichlmaier, Benno
• Granted Patent: US 9,078,391 B2
• Time in Patent Office: Days
• US Class Current: 701/50
• CPC Class Codes: A01B 63/10 operated by hydraulic or pneumatic means
• CPC Class Codes: A01B 63/112 to control draught load, i.e. tractive force
• CPC Class Codes: A01B 63/14 for implements drawn by animals or tractors
• CPC Class Codes: B62D 49/0628 using detachable weights counterweights against overturning B62D49/085; movable stabilisation masses B62D37/04
• CPC Class Codes: G01G 1/00 Weighing apparatus involving the use of a counterweight or other counterbalancing mass
• CPC Class Codes: G01G 19/08 for incorporation in vehicles

Abstract

A control system for a tractor (10) fitted with two or more axles (21, 22) which carry wheels (13, 14) having pneumatic tyres and which is set up to pull an implement or trailer. The system having a display means (28) for displaying to a tractor operator tractor performance parameters and has sensors to determine the current pull force (F) applied to the implement or trailer, the current wheel load and the current tractor ground speed (V). The system also has a control unit which determines and advises the tractor operator via the display means (28) as to the optimum weight of the tractor (10) using a predetermined relationship between pull force (F) and tractor weight and also the required load on each axle (21, 22) to achieve a predetermined optimum axle load ratio. The system also advises via the display means (28) the appropriate tyre pressure for the current wheel load and tractor ground speed (V) using a look-up table.

Claims

1. A control system for a tractor fitted with two or more axles which carry wheels having pneumatic tyres and which is set up to pull an implement or trailer, the system having a display means for displaying to a tractor operator tractor performance parameters and having sensors to determine the current pull force applied to the implement or trailer, the current wheel load and the current tractor ground speed, the system also having a processing unit which determines and advises the tractor operator via the display means as to the optimum weight of the tractor using a predetermined relationship between pull force and tractor weight and also the required load on each axle to achieve a predetermined optimum axle load ratio.

2. A system according to claim 1 in which the processing unit also advises the operator via the display means as to the appropriate tyre pressure for the current wheel load and tractor ground speed using a look-up table.

3. A system according to claim 2 in which the look-up table provides the lowest equal tyre pressure appropriate for the current wheel load, ground speed and tyre size fitted to the tractor to give minimum ground pressure to carry the load.

4. A system according to claim 1 in which the optimum axle load ratio applied is a 40/60 front/rear axle load ratio.

5. A system according to claim 1 in which the predetermined ratio of pull load/tractor weight is 0.4.

6. A system according to claim 1 in which the processing unit calculates a real time value for the current ratio of pull force/tractor weight.

7. A system according to claim 6 in which the real time value of the current ratio of pull force/tractor weight is calculated by measuring a plurality of individual values of pull force over a sample period and calculating in the processing unit the respective ratios therefrom, eliminating extreme and/or clearly incorrect or unrepresentative individual ratio values, averaging the ratio values in individual ratio zones and plotting these averaged zonal ratio values recorded in the sample period to generate a best fit curve for these plotted values, then selecting as the current real time value either the average ratio value for the ratio zone in which the tractor is operating for the longest time or the ratio on the curve with the highest value of tractive efficiency (pull force applied to implement or trailer/performance output at wheel hub).

8. A system according to claim 1 in which pull load is measured using sensing pins which attach the lower implement attachment links to the tractor.

9. A system according to any one of claim 1 for a tractor which includes a transmission with a hydraulic circuit in which a hydraulic pump supplies pressure to a hydraulic motor, the pull force being determined by sensing the pressure in the hydraulic circuit, whereby the pressure in the hydraulic circuit is a measure of the wheel or axle torque, the wheel or axle torque divided by the dynamic wheel radius is a measure for the wheel circumference force, consisting of rolling resistance force and pull thus giving a rough estimation of pull force.

10. A system according to claim 1 for a tractor with a rigid unsprung axle in which the wheel load is measured by a strain gauge type sensor which measures the deflection of part of the rigid axle which supports a wheel.

11. A system according to claim 1 for a tractor having an axle suspended by fluid pressure in which the wheel load is determined by measuring the fluid pressure which is suspending the axle and the position of the axle.

12. A system according to claim 1 to 11 in which the proportion of the weight of the implement or trailer which is supported by the tractor can be varied, the display means indicating the weight of the implement or trailer supported by the tractor to assist the operator in varying the axle load distribution towards the required figure determined by the system.

13. A system according to claim 12 in which a rear hitch which allows the attachment point of the implement or trailer to be moved in a fore, aft and/or downwards and upwards sense relative to the tractor to change the axle load distribution towards the required figure determined by the system.

14. A system according to claim 12 in which the vertical load applied by the implement or trailer to the tractor is measured using pressure sensors in hydraulic cylinders driving lower implement attachment links or top link.

15. A system according to claim 12 for a tractor provided with a weight which is movable in a fore and aft sense relative to the tractor, the display means indicating the change in axle load resulting from the movement of the weight to assist the operator in varying the axle load distribution towards the required figure determined by the system.

16. A system according to claim 1 for a tractor having driven front and rear axles and provided with a drive transmission which can vary the proportion of engine output torque which is directed to each axle, the display means displaying the output torque delivered to each axle.

17. A system according to claim 16 in which the processing means proportions the engine torque between the axles so that each wheel operates at substantially the same level of slip relative to the contacting ground independent of external operating conditions.

18. A system according to claim 17 in which the display means displays the wheel slip of each axle.

19. A system according to claim 1 in which the processing means calculates and the display means displays engine efficiency which is equal to the engine output performance at the crank shaft/output provided by the fuel consumed.

20. A system according to claim 1 in which the processing means calculates and the display means displays driveline efficiency which is equal to performance output at the wheel hub/performance output at the crank shaft.

21. A system according to claim 1 in which the processing means calculates and the display means displays tractive efficiency which is equal to the pull force applied to the implement or trailer/performance output at the wheel hub.

22. A system according claim 1 in which the processing means calculates and the display means displays crank to hitch efficiency which is equal to the pull force applied to the implement or trailer/performance output at the crank shaft.

23. A system according to claim 1 in which the processing means calculates and the display means displays tank to hitch efficiency which is equal to the pull force applied to the implement or trailer/output provided by the fuel consumed.

24. A system according to claim 1 in which the processing unit receives signals from sensors which determine various operating conditions of the tractor and operator'"'"'s inputs and process these signals and inputs to provide selected performance parameters for display on the display means, the processing means also providing a simulation mode in which the operator can enter proposed changes in operating conditions of the tractor and the processing means can indicate on the display means the effect of these proposed changes on selected tractor performance parameters.

25. A system according to claim 24 in which the display means advises the operator on changes which can be made to the operating conditions of the tractor to improve operating efficiency.

26. A system according to claim 25 in which the display means differentiates between measured values of displayed parameters, advised values of the displayed parameters, values of the displayed parameters changed by the operator and simulated values of the displayed parameters.

27. A system according to claim 26 in which the system differentiates between the different types of displayed parameters by using different display pages and/or separate pop-up menus and/or different colours for the different types of displayed values.

28. A system according to claim 24 in which the processing unit can be set up to issue output signals to automatically change certain operating conditions of the tractor to improve operating efficiency.

29. A system according to claim 24 in which the processing unit recognises when certain facilities or functions are not available on the tractor and advises the operator accordingly via the display means.

30. A system according to claim 1 in which the display means indicates the current axle and/or wheel loading of the tractor.

31. A system according to claim 6 in which the real time value of the current ratio of pull force/tractor weight is displayed on the display means.

32. A system according to claim 8 in which the display means displays the current pull force applied to the implement or trailer.

33. A control/display system for a tractor fitted with two or more axles which carry wheels and which is set up to pull an implement or trailer, the system having a display means for displaying to a tractor operator tractor performance parameters and having sensors to determine the current pull force applied to the implement or trailer and the current wheel load, the system also having a processing unit which determines the real time current ratio pull force and tractor weight by measuring a plurality of individual values of pull force over a sample period and calculating in the processing unit the respective ratios therefrom, eliminating extreme and/or clearly incorrect or unrepresentative individual ratio values, averaging the ratio values in individual ratio zones and plotting these averaged zonal ratio values recorded in the sample period to generate a best fit curve for these plotted values, then selecting as the current real time value either the average ratio value for the ratio zone in which the tractor is operating for the longest time or the ratio on the curve with the highest value of tractive efficiency (pull force applied to implement or trailer/performance output at wheel hub).