Switched-capacitor tuning of a proportional-integral-derivative controller

• US 10,359,740 B2
• Filed: 08/14/2017
• Issued: 07/23/2019
• Est. Priority Date: 08/14/2017
• Status: Active Grant

• Current Assignee: US Department of The Army (Government of the United States of America)
• Original Assignee: United States Of America As Represented By The Secretary Of The Army (Government of the United States of America)
• Inventors: Suarez, John
• Primary Examiner(s): Finch, III, Fred E
• Application Number:
  US15/675,812
• Publication Number:
  US 20190052170A1
• Time in Patent Office: 708 Days
• CPC Class Codes: G05B 11/42 for obtaining a characteristic which is both proportional and time-dependent, e.g. P. I., P. I. D.
• CPC Class Codes: G05B 13/024 in which a parameter or coefficient is automatically adjusted to optimise the performance
• CPC Class Codes: G05F 1/625 wherein it is irrelevant whether the variable actually regulated is ac or dc
• CPC Class Codes: H02M 1/0003 Details of control, feedback or regulation circuits
• CPC Class Codes: H02M 3/07 using capacitors charged and discharged alternately by semiconductor devices with control electrode , e.g. charge pumps

Abstract

Various embodiments are described that relate to a proportional-integral-derivative controller. The proportional-integral-derivative controller obtains an input voltage and from the input voltage produces an output voltage. Achievement of a particular output voltage can be accomplished through variable resistances in the proportional-integral-derivative controller. To realize these variable resistances, a switching capacitor set can be employed. The switching capacitor set can include individual capacitors with switches. The switches can function with a switching frequency. The switching frequency causes individual capacitors to function with an effective resistance. The resistance can directly correspond to the switching frequency. To change the resistance, the switching frequency can be changed.

Claims

1. A proportional-integral-derivative, comprising:

a first capacitor comprising a first capacitor first end and a first capacitor second end opposite the first capacitor first end;

a first switch comprising a first switch first end and a first switch second end,

a second capacitor comprising a first end and a second end opposite the first end; and

a second switch comprising a first end and a second end,

where the first switch first end is coupled to the first capacitor first end,

where the first switch second end alternates at a first frequency between at least two points such that a first resistance is produced,

where the second switch first end is coupled to the second capacitor first end,

where the second switch second end alternates at a second frequency between at least two points such that a second resistance is produced,

where the first resistance corresponds to the first frequency,

where the second resistance corresponds to the second frequency,

where the first resistance and the second resistance are different, and

where the first frequency and the second frequency are different

where upon identification of the first frequency the first switch alternates at the first frequency at a first point in time,

where, at a second point in time after the first point in time, the first switch drifts such that the first switch alternates at a drift frequency different from the first frequency, and

where, at a third point in time after the second point in time, a correction is made to the first switch such that the first switch returns to the first frequency,

where the proportional-integral-derivative controller produces an output voltage,

where the first frequency and the second frequency are selected through use of Ziegler-Nichols tuning rules such that the output voltage is non-oscillating, and

where the output voltage is a correction voltage for an error of an apparatus operatively coupled to the proportional-integral-derivative controller.

2. The proportional-integral-derivative controller of claim 1,

where the first frequency and the second frequency are selected such that the output voltage is a correction voltage for the error and a rate of change of the error.

3. The proportional-integral-derivative controller of claim 1,

where the drift frequency is a first drift frequency,

where upon identification of the second frequency the second switch alternates at the second frequency at a fourth point in time,

where, at a fifth point in time after the fourth point in time, the second switch drifts such that the second switch alternates at a second drift frequency different from the second frequency, and

where, at a sixth point in time after the fifth point in time, a correction is made to the second switch such that the second switch returns to the second frequency.

4. The proportional-integral-derivative controller of claim 3,

where the first point in time and the fourth point in time are the same point in time and

where the third point in time and the sixth point in time are the same point in time.

5. The proportional-integral-derivative controller of claim 4,

where the first frequency and the second frequency are selected such that the output voltage is a correction voltage for the error and a rate of change of the error.

6. The proportional-integral-derivative controller of claim 3,

where the first frequency and the second frequency are selected such that the output voltage is a correction voltage for the error and a rate of change of the error.

7. A non-transitory computer-readable medium communicatively coupled to a processor and configured to store a command set executable by the processor to facilitate operation of a component set, the component set comprising:

a frequency selection component configured to, through employment of Ziegler-Nichols tuning rules, select a switch frequency associated with a switched capacitor that is part of a proportional-integral-derivative controller; and

an effectuation component configured to cause the proportional-integral-derivative controller to be effectuated with the switch frequency at the switched capacitor such that a resistance is produced that is dependent on the switch frequency.

8. The non-transitory computer-readable medium of claim 7, the component set comprising:

a monitor component configured to monitor the switch frequency after the effectuation to produce a monitor result;

a comparison component configured to compare the monitor result against a threshold to produce a comparison result; and

an alteration component configured to cause an alteration to the switch frequency when the comparison result indicates the alteration should be made.

9. The non-transitory computer-readable medium of claim 8,

where the monitor component is configured to monitor the switch frequency when the switch frequency changes from a value at effectuation and

where the alteration returns the switch frequency to the value at effectuation.

10. The non-transitory computer-readable medium of claim 7, the component set comprising:

a stabilization component configured to cause an output of the proportional-integral-derivative controller to be stabilized.

11. The non-transitory computer-readable medium of claim 10,

where the output is a correction voltage for an error of an apparatus operatively coupled to the proportional-integral-derivative controller.

12. The non-transitory computer-readable medium of claim 10,

where the stabilization component employs digital direct synthesis to cause the stabilization.

13. The non-transitory computer-readable medium of claim 7, comprising:

an error component configured to identify a specific output voltage for production by the proportional-integral-derivative controller,

where the frequency selection component selects the switch frequency so that the proportional-integral-derivative controller produces a specific output voltage.

14. The non-transitory computer-readable medium of claim 13,

where the specific output voltage produced by the proportional-integral-derivative controller is unstable and

where the specific output voltage is stabilized post-proportional-integral-derivative controller.

15. A method, comprising:

collecting a current error value set for a system;

collecting a past error value set for the system;

collecting a future error value set for the system;

selecting, by way of a frequency selection component, a switching frequency for a switch of a switched capacitor to produce a correction voltage based, at least in part, on the current error value set the past error value set, and the future error value set; and

causing the switched capacitor to implement with the switching frequency,

where the switching frequency is selected such that the correction voltage is produced as a stable correction voltage,

where the switched capacitor produces a variable resistance based, at least in part, on the switching frequency for the switch,

where a proportional-integral-derivative controller performs the collecting the current error value set for the system, the collecting the past error value set for the system, and collecting the future error value set for the system, and

where the switched capacitor is not part of the proportional-integral-derivative controller.

16. The method of claim 15,

identifying, after causing the switch to implement with the switching frequency, the switch drifting to a drift frequency different from the switching frequency;

and

causing, after identifying the switch drifting, the switch to return to the switching frequency.

17. The method of claim 15,

where selecting the switching frequency occurs through employment of Ziegler-Nichols tuning rules.