System for controlling a machine with a continuously variable transmission

• US 20080269011A1
• Filed: 04/30/2007
• Published: 10/30/2008
• Est. Priority Date: 04/30/2007
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Sopko, Thomas M., Barngrover, Michael J., Kuras, Brian D.
• Granted Patent: US 7,854,681 B2
• Time in Patent Office: Days
• US Class Current: 477/34
• CPC Class Codes: B60K 6/46 Series type
• CPC Class Codes: B60L 2240/486 Operating parameters
• CPC Class Codes: B60W 10/04 including control of propulsion units
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/105 of electric type
• CPC Class Codes: B60W 2300/17 Construction vehicles, e.g. graders, excavators
• CPC Class Codes: B60W 2520/06 Direction of travel
• CPC Class Codes: B60W 2540/215 Selection or confirmation of options
• CPC Class Codes: B60W 2710/0644 Engine speed
• CPC Class Codes: B60W 2710/105 Output torque
• CPC Class Codes: B60W 30/188 Controlling power parameters of the driveline, e.g. determining the required power
• CPC Class Codes: B60W 50/082 Selecting or switching between different modes of propelling
• CPC Class Codes: B60W 50/085 Changing the parameters of the control units, e.g. changing limit values, working points by control input
• CPC Class Codes: B60Y 2200/14 Trucks; Load vehicles, Busses
• CPC Class Codes: Y02T 10/62 Hybrid vehicles

Abstract

A system for controlling a machine with a continuously variable transmission includes a first control device configured to produce a first signal based on a first operator input and a second control device configured to produce a second signal based on a second operator input. The system also includes a control system configured to receive the first and second signals from the first and second control devices and generate a raw torque value based on the first and second signals. The control system is also configured to determine an output torque value based on the raw torque value and transmit the output torque value to the transmission to control the transmission.

Claims

1. A system for controlling a machine with a continuously variable transmission, the system comprising:

a first control device configured to produce a first signal based on a first operator input;

a second control device configured to produce a second signal based on a second operator input; and

a control system configured to;

receive the first and second signals from the first and second control devices;

generate a raw torque value based on the first and second signals,

determine an output torque value based on the raw torque value, and

transmit the output torque value to the transmission to control the transmission.

2. The system of claim 1, wherein the second signal indicates a desired engine speed.

3. The system of claim 2, wherein:

the first signal produces a first value that decreases in magnitude as the first pedal moves toward a maximum displacement;

the second signal produces a second value that increases in magnitude as the second pedal moves toward a maximum displacement; and

the raw torque value is based on a multiplication of the first value and the second value.

4. The system of claim 2, further including:

a selector configured to receive an input from an operator, the operator input specifying a desired direction of movement, the selector being configured to produce a third signal based on the operator input, and

the raw torque value is based on a multiplication of the first signal, the second signal, and the third signal.

5. The system of claim 1, wherein the control system sends a brake command signal to a brake control device when the first pedal reaches a predetermined displacement.

6. The system of claim 1, wherein the first signal indicates a desired reverse torque and the second signal indicates a desired forward torque.

7. The system of claim 6, wherein:

the first signal produces a first value that increases in magnitude as the first pedal moves toward a maximum displacement;

the second signal produces a second value that increases in magnitude as the second pedal moves toward a maximum displacement; and

the raw torque value is based on a summation of the first value and the second value.

8. The system of claim 1, further including:

a third control device configured to produce a third signal based on a third operator input, and

the control system is configured to hold constant a desired engine speed until receiving the third signal from the third control device.

9. The system of claim 1, wherein the control system determines the output torque value based on the raw torque value and a predetermined correlation between at least one maximum torque and at least one speed.

10. The system of claim 9, wherein:

the predetermined correlation between at least one maximum torque and at least one speed is a maximum torque versus speed plot; and

the control system determines the output torque value based on a multiplication of the raw torque value and at least one torque value from the maximum torque versus speed plot.

11. The system of claim 9, wherein:

the predetermined correlation between at least one maximum torque and at least one speed is a maximum torque versus speed plot; and

the control system determines a maximum torque for a motor of the transmission;

the control system determines the output torque value based on at least one of the maximum torque versus speed plot and a multiplication of the maximum torque for the motor and the raw torque value.

12. The system of claim 1, further including:

a selector configured to receive an input from an operator, the operator input specifying a desired mode of operation, the mode of operation including a correlation between at least one speed and at least one torque percentage, and

the control system determines the output torque value based on the mode of operation specified by the operator and a torque percentage determined based on the correlation and a sensed speed.

13. The system of claim 1, further including:

a third control device configured to produce a third signal based on a third operator input;

the control system is configured to receive the third signal from the third control device and send a brake command signal to a brake control device based on the third signal, and

the first, second, and third control devices are foot pedals.

14. A system for controlling a machine with a continuously variable transmission, the system comprising:

a selector configured to receive an input from an operator, the operator input specifying a mode of operation, the mode of operation including a correlation between at least one speed and at least one torque modifying value;

a control system configured to;

determine an output torque value based on the mode of operation specified by the operator and a torque modifying value determined based on the correlation and a sensed speed; and

transmit the output torque value to the transmission to control the transmission.

15. The system of claim 14, further including at least one input device configured to receive an input from the operator, and the torque modifying value is based on the operator input.

16. The system of claim 14, wherein the torque modifying value is positive if the sensed speed is below a predetermined speed and negative if the sensed speed is above the predetermined speed.

17. The system of claim 16, wherein the torque modifying value is 100% when the sensed speed is less than a predetermined minimum speed and is −

100% when the sensed speed is greater than a predetermined maximum speed.

19. The method of claim 17, comprising:

generating a raw torque value based on a summation of the first signal and the second signal, and

the determining of the output torque value is based on the raw torque value.

18. A method of controlling a machine with a continuously variable transmission, the method comprising:

producing a first signal based on a first operator input, the first signal being associated with a reverse torque;

producing a second signal based on a second operator input, the second signal being associated with a forward torque;

determining an output torque value based on the first and second signals; and

transmitting the output torque value to the transmission to control the transmission.

20. The method of claim 18, wherein the determining of the output torque value is based on multiplying the raw torque value and at least one torque value from a maximum torque versus speed plot for a motor of the transmission.