Operation of wheeled work machine

• US 20030070859A1
• Filed: 10/11/2002
• Published: 04/17/2003
• Est. Priority Date: 10/12/2001
• Status: Active Grant

• Current Assignee: Clark Equipment Company (Doosan Enerbility Company Limited)
• Original Assignee: Clark Equipment Company (Doosan Enerbility Company Limited)
• Inventors: Henline, Michael J., Carpenter, Martin, Dahl, Jeffery A.
• Granted Patent: US 6,896,088 B2
• Time in Patent Office: Days
• US Class Current: 180/305
• CPC Class Codes: B60K 31/10 and means for comparing one electrical quantity, e.g. voltage, pulse, waveform, flux, or the like, with another quantity of a like kind, which comparison means is involved in the development of a pressure which is fed into the controlling means
• CPC Class Codes: B60W 10/04 including control of propulsion units
• CPC Class Codes: B60W 10/10 including control of change-speed gearings
• CPC Class Codes: B60W 10/103 of fluid type
• CPC Class Codes: B60W 10/18 including control of braking systems
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/12 Brake pedal position
• CPC Class Codes: B60W 2720/106 Longitudinal acceleration
• CPC Class Codes: B60W 30/1819 Propulsion control with control means using analogue circuits, relays or mechanical links
• CPC Class Codes: B60Y 2200/41 Construction vehicles, e.g. graders, excavators
• CPC Class Codes: B60Y 2200/415 Wheel loaders
• CPC Class Codes: E02F 3/283 with a single arm pivoted directly on the chassis linkage mechanism for it E02F3/3405
• CPC Class Codes: E02F 9/0808 Improving mounting or assembling, e.g. frame elements, disposition of all the components on the superstructures for disposition of specific components, E02F9/0858
• CPC Class Codes: E02F 9/2253 Controlling the travelling speed of vehicles, e.g. adjusting travelling speed according to implement loads, control of hydrostatic transmission
• CPC Class Codes: F16H 2059/183 Rate of change of accelerator position, i.e. pedal or throttle change gradient
• CPC Class Codes: F16H 59/141 of rate of change of torque or torque demand
• CPC Class Codes: F16H 59/18 dependent on the position of the accelerator pedal
• CPC Class Codes: F16H 59/54 dependent on signals from the brakes, e.g. parking brakes
• CPC Class Codes: F16H 61/42 involving adjustment of a pump or motor with adjustable output or capacity F16H61/46 takes precedence
• CPC Class Codes: F16H 61/47 for achieving a target output speed

Abstract

The present invention includes a control system for, or methods of controlling a wheeled work machine to accommodate desired travel control. Acceleration and deceleration inputs are provided, as is a controller for controlling hydrostatic motors to achieve desired acceleration and deceleration profiles.

Claims

1. A method of controlling a hydrostatic motor to control speed of travel of a wheeled work machine having an electronic controller, an acceleration operator input mechanism operably coupled to the electronic controller, and a deceleration operator input mechanism operably coupled to the electronic controller, comprising:

sensing movement of the acceleration operator input mechanism from a first position associated with a first speed set point to a second position;

obtaining a second speed set point associated with the second position; and

if the second speed set point is greater than the first speed set point, controlling the hydrostatic motor to accelerate the machine from the first speed set point to the second speed set point according to a predetermined acceleration curve.

2. The method of claim 1 and further comprising:

if the second speed set point is less than the first speed set point, controlling the hydrostatic motor to decelerate the machine from the first speed set point to the second speed set point according to a predetermined deceleration curve.

3. The method of claim 1 and further comprising:

sensing movement of the deceleration operator input mechanism from a neutral position to a first non-neutral position;

determining a rate of deceleration based on the non-neutral position of the deceleration operator input mechanism; and

controlling the hydrostatic motor to decelerate the machine based on the rate of deceleration determined.

4. The method of claim 3 and further comprising:

varying the rate of deceleration based on sensed movement of the deceleration operator input mechanism relative to the neutral position.

5. The method of claim 4 wherein varying the rate of deceleration comprises:

sensing movement of the deceleration operator input mechanism to a new non-neutral position;

obtaining a new rate of deceleration based on the new non-neutral position; and

controlling the hydrostatic motor to decelerate the machine based on the new rate of deceleration.

6. The method of claim 3 wherein controlling the hydrostatic motor to accelerate comprises:

sensing machine speed; and

comparing the sensed machine speed to the second speed set point.

7. The method of claim 3 wherein controlling the hydrostatic motor to decelerate comprises:

sensing machine speed; and

controlling the hydrostatic motor to decelerate the machine until the sensed speed is zero.

8. The method of claim 3 and further comprising:

sensing actuation of an operator actuable cruise control input mechanism; and

controlling the hydrostatic motor to maintain machine speed at least a current speed set point, regardless of whether the acceleration operator input mechanism is moved to a position corresponding to a speed set point that is less than the current speed set point.

9. The method of claim 3 and further comprising:

sensing actuation of an operator actuable cruise control input mechanism; and

controlling the hydrostatic motor to maintain machine speed at least a current machine speed, regardless of whether the acceleration operator input mechanism is moved to a position corresponding to a speed set point that is less than the current machine speed.

10. The method of claim 8 and further comprising:

if the acceleration operator input mechanism is moved to a position corresponding to a new speed set point that is greater than the current speed set point, controlling the hydrostatic motor to accelerate the machine from the current speed set point to the new speed set point.

11. The method of claim 10 and further comprising:

if the deceleration operator input mechanism is moved from a neutral position, ignoring the cruise control input; and

controlling the hydrostatic motor to decelerate the machine based on a position of the deceleration operator input mechanism.

12. The method of claim 1 and further comprising:

sensing operator actuation of a shift input mechanism indicative of a desired change to a new speed mode;

controlling the hydrostatic motor to change machine speed to a speed reflected by a new speed set point associated with a current position of the acceleration operator input mechanism; and

controlling the hydrostatic motor to control machine speed according to a new acceleration curve corresponding to the new speed mode.

13. The method of claim 3 and further comprising:

sensing movement of the deceleration operator input mechanism to a predetermined non-neutral brake position;

controlling the hydrostatic motor to decelerate the machine according to a predetermined rate of deceleration; and

when machine speed reaches zero, controlling the hydrostatic motor to engage a parking brake.

14. The method of claim 1 and further comprising:

receiving an engine speed selection input from an engine speed operator input mechanism; and

controlling whether the engine speed is controlled independently of, or dependent on, machine speed, based on the engine speed selection input.

15. A wheeled work machine, comprising:

a frame;

an operator compartment supported by the frame;

a set of wheels coupled to the frame;

a hydrostatic motor coupled to the wheels to drive the wheels to control speed of travel of a wheeled work machine;

an electronic controller;

an acceleration operator input mechanism operably coupled to the electronic controller; and

a deceleration operator input mechanism operably coupled to the electronic controller;

wherein the controller is configured to sense movement of the acceleration operator input mechanism from a first position associated with a first speed set point to a second position, obtain a second speed set point associated with the second position, and if the second speed set point is greater than the first speed set point, provide a speed signal to the hydrostatic motor to control the hydrostatic motor to accelerate the machine from the first speed set point to the second speed set point according to a predetermined acceleration curve.

16. The wheeled work machine of claim 15 wherein the controller is further configured to determine whether the second speed set point is less than the first speed set point and, if so, control the hydrostatic motor to decelerate the machine from the first speed set point to the second speed set point according to a predetermined deceleration curve.

17. The wheeled work machine of claim 16 wherein the controller is further configured to:

sense movement of the deceleration operator input mechanism from a neutral position to a first non-neutral position;

determine a rate of deceleration based on the non-neutral position of the deceleration operator input mechanism; and

control the hydrostatic motor to decelerate the machine based on the rate of deceleration determined.

18. The wheeled work machine of claim 17 wherein the controller is further configured to vary the rate of deceleration based on sensed movement of the deceleration operator input mechanism relative to the neutral position.

19. The wheeled work machine of claim 18 wherein the controller is configured to vary the rate of deceleration by sensing movement of the deceleration operator input mechanism to a new non-neutral position, obtaining a new rate of deceleration based on the new non-neutral position, and controlling the hydrostatic motor to decelerate the machine based on the new rate of deceleration.

20. The wheeled work machine of claim 17 and further comprising:

a machine speed sensor coupled to the controller and sensing machine speed; and

wherein the controller is configured to compare the sensed machine speed to the second speed set point to control acceleration of the machine.

21. The wheeled work machine of claim 17 wherein the controller is further configured to control the hydrostatic motor to decelerate the machine by controlling the hydrostatic motor to decelerate the machine until the sensed machine speed is zero.

22. The wheeled work machine of claim 17 and further comprising:

an operator actuable cruise control input mechanism; and

wherein the controller is configured to control the hydrostatic motor to maintain machine speed at least a current speed set point, regardless of whether the acceleration operator input mechanism is moved to a position corresponding to a speed set point that is less than the current speed set point.

23. The wheeled work machine of claim 17 and further comprising:

an operator actuable cruise control input mechanism; and

wherein the controller is configured to control the hydrostatic motor to maintain machine speed at least a current machine speed, regardless of whether the acceleration operator input mechanism is moved to a position corresponding to a speed set point that is less than the current speed set point.

24. The wheeled work machine of claim 22 wherein the controller is further configured to determine whether the acceleration operator input mechanism is moved to a position corresponding to a new speed set point that is greater than the current speed set point, and, if so, control the hydrostatic motor to accelerate the machine from the current speed set point to the new speed set point.

25. The wheeled work machine of claim 24 wherein the controller is further configured to determine whether the deceleration operator input mechanism is moved from a neutral position, and, if so, ignore the cruise control input and control the hydrostatic motor to decelerate the machine based on a position of the deceleration operator input mechanism.

26. The wheeled work machine of claim 15 and further comprising:

a shift input mechanism indicative of a desired change to a new speed mode; and

wherein the controller is further configured to control the hydrostatic motor to change machine speed to a speed reflected by a new speed set point associated with a current position of the acceleration operator input mechanism, and control the hydrostatic motor to control machine speed according to a new acceleration curve corresponding to the new speed mode.

27. The wheeled work machine of claim 17 wherein the deceleration operator input mechanism is movable to a predetermined non-neutral brake position, and wherein the controller is configured to control the hydrostatic motor to decelerate the machine according to a predetermined rate of deceleration and when machine speed reaches zero, control the hydrostatic motor to engage a parking brake.

28. The wheeled work machine of claim 15 and further comprising:

an engine speed operator input mechanism; and

wherein the controller is further configured to control whether the engine speed is controlled independently of, or dependent on, machine speed, based on an input from the engine speed operator input mechanism.