System and method for conditioning a signal

• US 7,078,872 B2
• Filed: 05/30/2003
• Issued: 07/18/2006
• Est. Priority Date: 05/30/2003
• Status: Expired due to Fees

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Kuras, Brian D., Bertsch, Robert P.
• Primary Examiner(s): Duda, Rina
• Assistant Examiner(s): Glass, Erick
• Application Number:
  US10/448,985
• Publication Number:
  US 20040239281A1
• Time in Patent Office: 1,145 Days
• Field of Search: 388/800, 388/805, 388/812, 388/814, 388/820, 388/906, 318/807, 318/616, 318/800, 318/805, 318/812, 318/814, 318/820, 375229-336, 375240-2402, 702189-197, 333/17.1, 708322-323
• US Class Current: 318/610
• CPC Class Codes: G05B 11/42 for obtaining a characteristic which is both proportional and time-dependent, e.g. P. I., P. I. D.

Abstract

A method of conditioning a signal being communicated between a system to be controlled and a controller may include monitoring an actual output signal and conditioning the actual output signal. The method also includes determining the difference between the actual output signal and the condition signal and causing the actual output signal to be filtered based on the relationship between the difference between the actual output signal and the conditioned signal.

Claims

1. A method of conditioning a signal being communicated between a system to be controlled and a controller, the method comprising:

monitoring an actual output signal;

filtering the actual output signal by using at least one filter to provide a filtered signal;

determining a difference between the actual output signal and the filtered signal; and

setting at least one characteristic parameter of the at least one filter based on the difference between the actual output signal and the filtered signal,

wherein the at least one characteristic parameter includes a corner frequency of the at least one filter.

2. The method according to claim 1, wherein the corner frequency is based on a corner frequency function defined to include:

a first region representing noise signals;

a second region representing mixed noise and true signals; and

a third region representing true signals.

3. The method according to claim 1, wherein the setting further includes:

decreasing the corner frequency of the at least one filter such that the actual signal is significantly filtered by the at least one filter if the difference is less than a predetermined value; and

increasing the corner frequency of the at least one filter such that the actual signal passes through the at least one filter without filtering if the difference is greater than the predetermined value.

4. The method according to claim 1, further including:

processing the actual output signal by applying the at least one filter.

5. A method of controlling a motor, the method comprising:

monitoring an actual output signal of the motor;

filtering the actual output signal of the motor by using a filter to provide a filtered signal;

determining a difference between the actual output signal and the filtered signal;

setting a corner frequency of the filter based upon the determined difference; and

causing the actual output signal to be filtered by the filter.

6. The method according to claim 5, wherein causing the actual output signal to be filtered further includes applying at least one of the filter and a closed loop control to the actual output signal based on the determined difference.

7. A method of conditioning a signal being communicated between a system to be controlled and a controller, the method comprising:

monitoring an actual output signal;

filtering the actual output sIgnal to provide a filtered signal;

determining a difference between the actual output signal and the filtered signal; and

processing the actual output signal based on the difference between the actual output signal and the filtered signal,

wherein the filtering further includes;

filtering the actual signal based on a corner frequency function defined to include;

a first region representing noise signals;

a second region representing mixed noise and true signals; and

a third region representing true signals.

8. A method of conditioning a signal being communicated between a system to be controlled and a controller, the method comprising:

monitoring an actual output signal;

filtering the actual output signal to provide a filtered signal;

determining a difference between the actual output signal and the filtered signal; and

applying both a filter and closed loop control to the actual output signal based on the difference between the actual output signal and the filtered signal,

wherein the closed loop control consists of Proportional Integral Differential (PID) closed loop control with deadband.

9. A method of conditioning a signal being communicated between a system to be controlled and a controller, the method comprising:

monitoring an actual output signal;

filtering the actual output signal to provide a filtered signal;

determining a difference between the actual output signal and the filtered signal; and

applying both a filter and closed loop control to the actual output signal based on the difference between the actual output signal and the filtered signal,

wherein the closed loop control includes;

determining a difference between the actual output signal and a desired input command signal;

establishing a deadband around the difference between the actual output signal and the desired input command signal; and

applying the closed loop control to the actual output signal based on a relationship between the deadband and the difference between the actual output signal and the desired input command signal.