Skid steer loader neutral drift correction method

• US 6,735,889 B1
• Filed: 01/14/2003
• Issued: 05/18/2004
• Est. Priority Date: 01/14/2003
• Status: Expired due to Term

• Current Assignee: Blue Leaf IP Incorporated (CNH Industrial N.V.), CNH America Llc (CNH Industrial N.V.)
• Original Assignee: New Holland North America Incorporated (CNH Industrial N.V.)
• Inventors: Berger, John G., Haupt, John R.
• Primary Examiner(s): Pezzuto, Robert E.
• Application Number:
  US10/341,461
• Time in Patent Office: 490 Days
• Field of Search: 373/47, 373/48, 374/14, 373/82, 701/50, 701/53, 701/56, 172/2-12, 180/333, 417/212, 417/213, 417/216, 414/695-700, 414/715, 414/720
• US Class Current: 37/348
• CPC Class Codes: E02F 9/2004 Control mechanisms, e.g. control levers control levers per se G05G
• CPC Class Codes: E02F 9/2025 Particular purposes of control systems not otherwise provided for E02F3/16, E02F3/26, sub-groups of E02F3/43, E02F3/651, sub-groups of E02F3/84, E02F3/907, E02F5/145 take precedence

Abstract

A method of manual control neutral drift correction for a work vehicle is characterized by the steps of: sensing a position of a first manual control using a first position sensor when an activation switch is activated, wherein the first position sensor generates a first input signal; sending the first input signal to a controller; retrieving a stored first manual control neutral position value from a memory unit; calculating a first corrected manual control neutral position value using the controller, wherein the first corrected manual control neutral position value is calculated using the first input signal and the first manual control position value; and utilizing the first corrected manual control neutral position value to generate a first control signal for operating a first electro-hydraulic valve, wherein the first control signal is generated by the controller to operate the first electro-hydraulic valve to effect movement of a first assembly.

Claims

1. A method of manual control neutral drift correction for a work vehicle, comprising the steps of:

(a) sensing a position of a first manual control using a first position sensor when an activation switch is activated, wherein the first position sensor generates a first input signal;

(b) sending the first input signal to a controller;

(c) retrieving a stored first manual control neutral position value from a memory unit;

(d) calculating a first corrected manual control neutral position value using the controller, wherein the first corrected manual control neutral position value is calculated using the first input signal and the first manual control position value; and

(e) utilizing the first corrected manual control neutral position value to generate a first control signal for operating a first electro-hydraulic valve, wherein the first control signal is generated by the controller to operate the first electro-hydraulic valve to effect movement of a first assembly.

2. A method of manual control neutral drift correction as recited in claim 1, wherein calculation of the first corrected manual control neutral position value is a weighted average calculated as a function of the first input signal and the first manual control position value.

3. A method of manual control neutral drift correction as recited in claim 2, wherein the first corrected manual control neutral position value is the weighted average calculated using formula I:

4. A method as recited in claim 1, wherein the first manual control is a right foot pedal manual control, the first position sensor is a right foot pedal implement position sensor, and the first assembly is an implement assembly, wherein the implement assembly moves when the first electro-hydraulic valve receives the first control signal.

5. A method as recited in claim 1, wherein the first manual control is a left hand grip manual control, the first position sensor is a left hand stick boom arm position sensor, and the first assembly is a boom arm assembly, wherein the boom arm assembly moves when the first electro-hydraulic valve receives the first control signal.

6. A method as recited in claim 1, wherein the first manual control is a left foot pedal manual control, the first position sensor is a left foot pedal boom arm position sensor, and the first assembly is a boom arm assembly, wherein the boom arm assembly moves when the first electro-hydraulic valve receives the first control signal.

7. A method as recited in claim 1, wherein the first manual control is a right hand grip manual control, the first position sensor is a right hand stick implement position sensor, and the first assembly is an implement assembly, wherein the implement assembly moves when the first electro-hydraulic valve receives the first control signal.

8. A method according to claim 1, wherein the first manual control is a hand grip manual control, and the first position sensor is a hand grip position sensor.

9. A method according to claim 1, wherein the first manual control is a foot pedal manual control, and the first position sensor is a foot pedal position sensor.

10. A method according to claim 8, wherein the first assembly is an implement assembly.

11. A method according to claim 9, wherein the first assembly is an implement assembly.

12. A method according to claim 8, wherein the first assembly is a boom arm assembly.

13. A method according to claim 9, wherein the first assembly is a boom arm assembly.

14. A method as recited in claim 1, wherein activating the activation switch enables the first manual control and disables a second manual control.

15. A method of manual control neutral drift correction as recited in claim 14, wherein the first manual control is a right hand grip manual control, the second manual control is a right foot pedal manual control, the first position sensor is a right hand stick implement position sensor, and the first assembly is an implement assembly, wherein the implement assembly moves when the first electro-hydraulic valve receives the first control signal.

16. A method of manual control neutral drift correction as recited in claim 14, wherein the first manual control is a right foot pedal manual control, the second manual control is a right hand grip manual control, the first position sensor is a right foot pedal implement position sensor, and the first assembly is an implement assembly, wherein the implement assembly moves when the first electro-hydraulic valve receives the first control signal.

17. A method as recited in claim 14, wherein the first manual control is a left hand grip manual control, the second manual control is a left foot pedal manual control, the first position sensor is a left hand stick boom position sensor, and the first assembly is a boom arm assembly, wherein the boom arm assembly moves when the first electro-hydraulic valve receives the first control signal.

18. A method as recited in claim 14, wherein the first manual control is a left foot pedal manual control, the second manual control is a left hand grip manual control, the first position sensor is a left foot pedal boom position sensor, and the first assembly is a boom arm assembly, wherein the boom arm assembly moves when the first electro-hydraulic valve receives the first control signal.

19. A method as recited in claim 1, further comprising the steps of:

(f) when the activation switch is activated, sensing a position of a second manual control using a second position sensor, sensing a position of a third manual control using a third position sensor, and sensing a position of a fourth manual control using a fourth position sensor, wherein the second position sensor generates a second input signal, the third position sensor generates a third input signal and the fourth position sensor generates a fourth input signal;

(g) sending the second input signal, the third input signal and the fourth input signal to the controller;

(h) retrieving a stored second manual control neutral position value, a stored third manual control neutral position value and a stored fourth manual control neutral position value from the memory unit;

(i) calculating a second corrected manual control neutral position value using the controller, wherein the second corrected manual control neutral position value is calculated using the second input signal and the second manual control position value;

(j) calculating a third corrected manual control neutral position value using the controller, wherein the third corrected manual control neutral position value is calculated using the third input signal and the third manual control position value; and

(k) calculating a fourth corrected manual control neutral position value using the controller, wherein the fourth corrected manual control neutral position value is calculated using the fourth input signal and the fourth manual control position value.

20. A method as recited in claim 19, further comprising the step of:

(l) utilizing the second corrected manual control neutral position value to generate a second control signal for operating a second electro-hydraulic valve, wherein the second control signal is generated by the controller to operate the second electro-hydraulic valve to effect movement of a second assembly.

21. A method as recited in claim 20, further comprising the step of:

(m) storing the first corrected manual control neutral position value, the second corrected manual control neutral position value, the third corrected manual control neutral position value, and the fourth corrected manual control neutral position value in the memory unit.

22. A method of manual control neutral drift correction as recited in claim 19, wherein activating the activation switch enables the first manual control and the second manual control while disabling the third manual control and the fourth manual control.

23. A method as recited in claim 1, further comprising the step of:

(f) storing the first corrected manual control neutral position value in the memory unit.

24. A work vehicle comprising:

a frame;

a boom arm assembly connected at one end to the frame;

an implement assembly pivotally connected to another end of the boom arm assembly, wherein the implement assembly includes an implement;

a first hydraulic implement cylinder connected to the implement assembly and positioned to pivotally rotate the implement relative to the boom arm assembly when a piston of the first hydraulic implement cylinder is extended or retracted, wherein the first hydraulic implement cylinder is connected to a first electrohydraulic valve that activates extension and retraction of the piston of the first implement cylinder;

a second hydraulic boom cylinder connected to the boom arm assembly and positioned to move the boom arm assembly between a first retracted position and a second extended position when a piston of the second boom cylinder is retracted and extended, respectively, wherein the second hydraulic boom cylinder is connected to a second electrohydraulic valve that activates extension and retraction of the piston of the second hydraulic cylinder;

a first position sensor disposed to sense a position of a first manual control and generate a first input signal;

a second position sensor disposed to sense a position of a second manual control and generate a second input signal;

a controller connected to receive the first input signal from the first position sensor and the second input signal from the second position sensor, and connected to send a first control signal to the first electrohydraulic valve and a second control signal to the second electrohydraulic valve; and

an activation switch connected to send an activation signal to the controller, wherein when the activation signal is sent to the controller, the controller retrieves a first manual control neutral position value and a second manual control neutral position value from a memory storage device connected to provide stored data to the controller and the controller calculates a first corrected manual control neutral position value and a second corrected manual control neutral position value using the first input signal, the second input signal, the first manual control neutral position value and the second manual control neutral position value, wherein the controller generates the first control signal using the first corrected manual control neutral position value and generates the second control signal using the second corrected manual control neutral position value.

25. A work vehicle as recited in claim 24, further comprising:

a third position sensor disposed to sense a position of a third manual control and generate a third input signal; and

a fourth position sensor disposed to sense a position of a fourth manual control and generate a fourth input signal, wherein the controller is connected to receive the third input from the third position sensor and to receive the fourth input from the fourth position sensor, wherein when the activation signal is sent to the controller, the controller retrieves a third manual control neutral position value and a fourth manual control neutral position value from the memory storage device connected to provide stored data to the controller and the controller calculates a third corrected manual control neutral position value and a fourth corrected manual control neutral position value using the third input signal, the fourth input signal, the third manual control neutral position value and the fourth manual control neutral position value.

26. A work vehicle as recited in claim 25, wherein the first manual control and the second manual control are manual hand grip controls and the third manual control and the fourth manual controls are manual foot pedal controls, wherein the controller enables the first manual control and the second manual control and disables the third manual control and the fourth manual control in response to receiving the activation signal from the activation switch.

27. A work vehicle as recited in claim 25, wherein the first manual control and the second manual control are manual foot pedal controls and the third manual control and the fourth manual controls are manual hand grip controls, wherein the controller enables the first manual control and the second manual control and disables the third manual control and the fourth manual control in response to receiving the activation signal from the activation switch.

28. A work vehicle as recited in claim 25, wherein the memory storage device is integrally connected to the controller and forms a portion of the controller.

29. A work vehicle as recited in claim 25, wherein the memory storage device is an external non-volatile memory unit connected to the controller.