Torque load control system and method

• US 8,793,002 B2
• Filed: 06/20/2008
• Issued: 07/29/2014
• Est. Priority Date: 06/20/2008
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Anderson, Randall T., Gorman, Corey L.
• Primary Examiner(s): KASENGE, CHARLES R
• Application Number:
  US12/213,527
• Publication Number:
  US 20090319136A1
• Time in Patent Office: 2,230 Days
• Field of Search: 700/28, 700/52, 701/51, 701/53, 701/54, 477/107, 477/109, 477/110
• US Class Current: 700/28
• CPC Class Codes: B60W 50/06 Improving the dynamic response of the control system, e.g. improving the speed of regulation or avoiding hunting or overshoot
• CPC Class Codes: E02F 9/2246 Control of prime movers, e.g. depending on the hydraulic load of work tools
• CPC Class Codes: F02D 2250/26 by applying a torque limit
• CPC Class Codes: F02D 41/021 Introducing corrections for particular conditions exterior to the engine conjoint control of vehicle sub-units for propelling the vehicle B60W30/18
• CPC Class Codes: F02D 41/1497 With detection of the mechanical response of the engine

Abstract

A machine may include a torque producing system, and a torque consuming device including load controls operable to generate a request for torque. The machine may also include a control system coupled to the torque producing system and the load controls. The control system may be operable to receive the request for torque, determine a torque limit based on the requested torque, and communicate the torque limit to the load controls, the load controls being operable to adjust operation of the torque consuming device based on the torque limit.

Claims

1. A machine comprising:

a torque producing system;

one or more torque consuming devices operable to exert a torque load on the torque producing system;

a control system coupled to the torque producing system and the one or more torque consuming devices, the control system configured to limit operation of the one or more torque consuming devices to prevent a speed of the torque producing system from falling below a predetermined speed, the control system including

a torque error estimator, and

one or more electronic devices operable to sense operating conditions of the torque producing system and the one or more torque consuming devices, and provide torque data to the control system based on the sensed operating conditions, the torque error estimator being operable to compensate for error in the torque data.

2. The machine of claim 1, wherein the error is at least partially caused by inaccuracy of the one or more electronic devices.

3. The machine of claim 2, wherein the error is at least partially caused by the one or more electronic devices being incapable of sensing the operating conditions of an additional torque consuming device.

4. The machine of claim 2, wherein the control system is operable to calculate a torque load limit with the torque data.

5. An electronic control module including instructions for performing a method, the method comprising:

obtaining input signals related to at least one of a torque producing system and a torque consuming device;

calculating an initial error value indicative of error associated with at least one of the torque producing system and the torque consuming device based on the input signals;

subtracting a feedback value from the initial error value to calculate a modified error value; and

adjusting the modified error value to produce an adjusted error value used to control operation of the torque consuming device to thereby prevent a reduction in a speed of the torque producing system below a predetermined speed.

6. The electronic control module of claim 5, wherein the adjusted error value becomes a new feedback value.

7. The electronic control module of claim 5, wherein the adjusted error value is used to adjust a torque load limit for the torque producing system.

8. The electronic control module of claim 5, wherein the input signals include torque data for at least one of the torque producing system and the torque consuming device.

9. The electronic control module of claim 5, wherein the adjusted error value is used to set a limit on a torque load exerted by the torque consuming device on the torque producing system.

10. A machine comprising:

a torque producing system;

torque consuming devices operable to exert a torque load on the torque producing system;

a control system operable to determine a torque load limit for the torque producing system, the control system being

in communication with the torque producing system,

communicatively linked to one or more first torque consuming devices,

uncommunicative with one or more second torque consuming devices,

operable to calculate torque consumed by the one or more first torque consuming devices based at least in part on communications from the one or more first torque consuming devices and on an amount of torque being produced by the torque producing system, and calculate torque consumed by the one or more second torque consuming devices based on sensed operating conditions of the machine, control an operation of the one or more first and the one or more second torque consuming devices based on the torque limit, and

operable to prevent a speed of the torque producing system from falling below a predetermined speed.

11. The machine of claim 10, wherein the control system is operable to take into account the torque consumed by the one or more first torque consuming devices, and the torque consumed by the one or more second torque consuming devices, to determine the torque load limit.

12. The machine of claim 10, wherein the control system is operable to maintain the torque load at or below the torque load limit.

13. The machine of claim 10, wherein the control system is communicatively linked to the one or more first torque consuming devices by one or more sensors operable to sense operating conditions of the one or more first torque consuming devices.

14. Anon transitory electronic control module including instructions for performing a method, the method comprising:

determining an amount of available torque currently available from a torque producing system;

determining a torque load limit for the torque producing system based on the determined amount of available torque currently available and an operating speed of the torque producing system, including determining the torque load limit in a manner to prevent the operating speed from decaying at a rate greater than a target deceleration rate; and

controlling one or more torque consuming devices that receive torque from the torque producing system based on the torque load,

wherein determining the torque load limit includes determining an inertial torque based on the difference between the operating speed and the underspeed set point.

15. The non-transitory electronic control module of claim 14, wherein determining the torque load limit includes determining a difference between the operating speed and an underspeed set point of the torque producing system.

16. The non-transitory electronic control module of claim 14, wherein determining the torque load limit includes adjusting the torque load limit based on the inertial torque.

17. The non-transitory electronic control module of Claim 16, wherein determining the torque load limit includes limiting the inertial torque to a target range to prevent the operating speed from decaying at a rate greater than the target deceleration rate.