Resonance suppression control circuit and testing system employing same, and method of designing resonance suppression control circuit

• US 10,444,117 B2
• Filed: 06/19/2017
• Issued: 10/15/2019
• Est. Priority Date: 06/22/2016
• Status: Active Grant

• Current Assignee: Meidensha Corporation
• Original Assignee: Meidensha Corporation
• Inventors: Akiyama, Takao
• Primary Examiner(s): Kirkland, III, Freddie
• Application Number:
  US16/312,961
• Publication Number:
  US 20190219481A1
• Time in Patent Office: 848 Days
• CPC Class Codes: G01M 13/02 Gearings; Transmission mechanisms
• CPC Class Codes: G01M 13/025 Test-benches with rotational drive means and loading means; Load or drive simulation
• CPC Class Codes: G01M 15/02 Details or accessories of testing apparatus
• CPC Class Codes: G01M 15/044 by monitoring power, e.g. by operating the engine with one of the ignitions interrupted; by using acceleration tests
• CPC Class Codes: G05B 13/02 electric
• CPC Class Codes: G05B 13/04 involving the use of models or simulators
• CPC Class Codes: H02P 23/04 specially adapted for damping motor oscillations, e.g. for reducing hunting
• CPC Class Codes: H02P 6/08 Arrangements for controlling the speed or torque of a single motor H02P6/10, H02P6/28 take precedence

Abstract

A resonance suppression control circuit provides operation stable for variations with a low order mode of vibration and suppressing spill-over due to high order mode of vibration. This circuit controls a physical system having two or more modes of vibration, and suppresses resonance in a lowest order mode of vibration from among the plurality of modes. The circuit has a controller designed by a μ design method, using a generalized plant with nominal model, and structured perturbation to the generalized plant. The nominal model is represented by the product of a low order vibration mode transfer function having the low order mode of vibration to be suppressed, and a high order vibration mode transfer function having a high order mode of vibration. The structured perturbation includes a first parameter perturbation term which imparts a multiplicative error to a spring constant included in the vibration mode transfer function being suppressed.

Claims

1. A resonance suppression control circuit which, establishing a physical system having a plurality of at least two vibration modes configured by connecting an electric motor and a test piece by a shaft, suppresses resonance in at least one vibration mode among the plurality of vibration modes by applying an input to the electric motor,

wherein the resonance suppression control circuit comprises a controller designed by way of a control system design method designated as μ

design method using a generalized plant which includes a nominal model imitating input/output characteristics of the control target from an input of the electric motor until shaft torque of the shaft, and a structured perturbation relative to the generalized plant,

wherein the nominal model defines one among the plurality of vibration modes as a suppression target, and is represented by the product of a suppression target vibration mode transfer function having a vibration mode of the suppression target, and a high-order vibration mode transfer function having a vibration mode which is higher order than the vibration mode of the suppression target, and

wherein the structured perturbation includes at least one perturbation term relative to a parameter included in the suppression target vibration mode transfer function.

2. The resonance suppression control circuit according to claim 1, wherein a transfer function from an input to an inertia field until an output of a shaft element in a one-degree-of-freedom vibration system configured by connecting the inertia field having a predetermined moment of inertia and a solid wall by the shaft element having a predetermined spring constant and damping constant, is used in the suppression target vibration mode transfer function.

3. The resonance suppression control circuit according to claim 2, wherein the structured perturbation includes a perturbation term relative to the spring constant.

4. The resonance suppression control circuit according to claim 2, wherein the structured perturbation includes a perturbation term relative to the moment of inertia.

5. The resonance suppression control circuit according claim 2, wherein, when defining a pole of the suppression target vibration mode transfer function as “

pR” and

defining a complex conjugate thereof as “

pR*”

, the spring constant K1, the damping constant C1 and the suppression target vibration mode transfer function M1(s) are represented by Formula (1) below

6. The resonance suppression control circuit according to claim 2, wherein the high-order vibration mode transfer function is identified so that a transfer function obtained by multiplying this high-order vibration mode transfer function and the suppression target vibration mode transfer function matches a transfer function from an input to the electric motor of the suppression target until a shaft torque of the shaft.

7. A test system comprising:

an electric motor which is connected with a test piece via a shaft;

a shaft torque meter which detects shaft torque generated at the shaft;

an inverter which supplies electric power to the electric motor; and

a resonance suppression control circuit which generates, using a command signal relative to generated torque of the electric motor and a detection signal of the shaft torque meter, a torque current command signal to the electric motor so that resonance of the shaft is suppressed, and then inputs the torque current command signal to the inverter,

wherein a resonance suppression control circuit according to claim 2 is used as the resonance suppression control circuit.

8. The resonance suppression control circuit according to claim 1, wherein a transfer function from an input to a first inertia field until an output of a shaft element in a two inertia system configured by connecting the first inertia field having a predetermined first moment of inertia and a second inertia field having a predetermined second moment of inertia by the shaft element having a predetermined spring constant and damping constant, is used in the suppression target vibration mode transfer function.

9. The resonance suppression control circuit according to claim 8, wherein the structured perturbation includes a perturbation term relative to the spring constant.

10. The resonance suppression control circuit according to claim 8, wherein the structured perturbation includes a perturbation term relative to the second moment of inertia.

11. The resonance suppression control circuit according to claim 8, wherein the structured perturbation includes a perturbation term relative to the first moment of inertia.

12. The resonance suppression control circuit according to claim 8, wherein the structured perturbation includes a perturbation term relative to the spring constant and a perturbation term relative to the second moment of inertia.

13. The resonance suppression control circuit according to claim 8, wherein, when defining a pole of the suppression target vibration mode transfer function as “

p_R”

, defining a complex conjugate thereof as “

p_R*”

, defining the first moment of inertia as “

J1” and

defining the second moment of inertia as “

J2”

, the spring constant K2, the damping constant C2 and the suppression target vibration mode transfer function M2(s) are represented by Formula (2) below

14. A test system comprising:

an electric motor which is connected with a test piece via a shaft;

a shaft torque meter which detects shaft torque generated at the shaft;

an inverter which supplies electric power to the electric motor; and

a resonance suppression control circuit which generates, using a command signal relative to generated torque of the electric motor and a detection signal of the shaft torque meter, a torque current command signal to the electric motor so that resonance of the shaft is suppressed, and then inputs the torque current command signal to the inverter,

wherein a resonance suppression control circuit according to claim 13 is used as the resonance suppression control circuit.

15. The resonance suppression control circuit according to claim 8, wherein the high-order vibration mode transfer function is identified so that a transfer function obtained by multiplying this high-order vibration mode transfer function and the suppression target vibration mode transfer function matches a transfer function from an input to the electric motor of the suppression target until a shaft torque of the shaft.

16. A test system comprising:

an electric motor which is connected with a test piece via a shaft;

a shaft torque meter which detects shaft torque generated at the shaft;

an inverter which supplies electric power to the electric motor; and

a resonance suppression control circuit which generates, using a command signal relative to generated torque of the electric motor and a detection signal of the shaft torque meter, a torque current command signal to the electric motor so that resonance of the shaft is suppressed, and then inputs the torque current command signal to the inverter,

wherein a resonance suppression control circuit according to claim 8 is used as the resonance suppression control circuit.

17. The resonance suppression control circuit according to claim 1, wherein the high-order vibration mode transfer function is identified so that a transfer function obtained by multiplying this high-order vibration mode transfer function and the suppression target vibration mode transfer function matches a transfer function from an input to the electric motor of the suppression target until a shaft torque of the shaft.

18. A test system comprising:

an electric motor which is connected with a test piece via a shaft;

a shaft torque meter which detects shaft torque generated at the shaft;

an inverter which supplies electric power to the electric motor; and

a resonance suppression control circuit which generates, using a command signal relative to generated torque of the electric motor and a detection signal of the shaft torque meter, a torque current command signal to the electric motor so that resonance of the shaft is suppressed, and then inputs the torque current command signal to the inverter,

wherein a resonance suppression control circuit according to claim 17 is used as the resonance suppression control circuit.

19. A test system comprising:

an electric motor which is connected with a test piece via a shaft;

a shaft torque meter which detects shaft torque generated at the shaft;

an inverter which supplies electric power to the electric motor; and

a resonance suppression control circuit which generates, using a command signal relative to generated torque of the electric motor and a detection signal of the shaft torque meter, a torque current command signal to the electric motor so that resonance of the shaft is suppressed, and then inputs the torque current command signal to the inverter,

wherein a resonance suppression control circuit according to claim 1 is used as the resonance suppression control circuit.

20. A method of designing a resonance suppression control circuit which, establishing a physical system configured by connecting an electric motor and a test piece by a shaft, and having a plurality of at least two vibration modes as a control target, suppresses resonance in at least one vibration mode among the plurality of vibration modes by applying an input to the electric motor, the method comprising:

defining one among the plurality of vibration modes as a suppression target, and stipulating a generalized plant which includes nominal model imitating input/output characteristics of the control target from an input to the electric motor until a shaft torque of the shaft, by a product of a suppression target vibration mode transfer function having a vibration mode of the suppression target, and a high-order vibration mode transfer function having a vibration mode which is higher order than the vibration mode of the suppression target;

stipulating a structured perturbation which includes at least one perturbation term relative to a parameter included in the suppression target vibration mode transfer function in the generalized plant; and

designing the resonance suppression control circuit by way of a suppression system design method designated as pt design method using the stipulated generalized plant and structured perturbation.