Method and apparatus for reducing resonance in a dual inertia system
AssigneeRockwell Technologies, LLC
InventorsThomas J. Rehm, Peter B. Schmidt
Life of this patent
Estimating the term…
Abstract
A method and apparatus for minimizing resonant oscillations in a dual inertia system characterized by minimally stable poles and both a resonant frequency and an anti-resonant frequency, the apparatus including a notch filter which is tuned so that notch filter zeros essentially cancel the minimally stable poles and so that at least one notch pole is located at the intersection of a real axis and an system anti-resonant zero radius on a root-loci plot, thereby rendering an exceptionally stable system, the method for tuning the notch filter as described.
Claims8
A method for use in a configuration including a controller and a dual energy system, the system including a drive component and a load component, the controller controlling the drive component and the drive component driving the load component, the system characterized generally by a second order transfer function including two system resonant poles and two system zeros and having a resonant frequency .omega..sub.r and an anti-resonant frequency .omega..sub.ar, the method for minimizing resonance, the method comprising the steps of:
- providing a notch filter characterized by a Laplace domain transfer function:
- ##EQU15## where A is a tuning variable, R is a damping term and .omega..sub.n is a natural frequency;
- and
- tuning the transfer function such that natural frequency .omega..sub.n is equal to resonant frequency .omega..sub.r and a damping term R=(.omega..sub.ar /.omega..sub.r)+(.omega..sub.r /.omega..sub.ar).
A method for use in a configuration including a controller, a dual energy system and a notch filter, the system including a drive component and a load component, the controller controlling the drive component and the drive component driving the load component, the system characterized generally by a second order transfer function including two system resonant poles and two system zeros and having a resonant frequency T.sub.r and an anti-resonant frequency T.sub.ar, the notch filter characterized by a second order transfer function also having two poles and two zeros, the method for minimizing resonance and comprising the steps of:
- selecting notch filter transfer function zeros to cancel the system resonant poles wherein the notch filter transfer function in the Laplace domain is ##EQU18## where A is a tuning variable, R is a damping term and .omega..sub.n is a natural frequency;
- and
- selecting notch filter poles so that both notch filter poles are on the real axis of a root-loci s-plane and one of the poles is on the real axis at a radius which is equal to the magnitude of the system zeros, the step of selecting notch filter poles including the step of tuning the notch filter such that natural frequency .omega..sub.n is equal to resonant frequency .omega..sub.r and damping term R=(T.sub.ar /T.sub.r)+(T.sub.r /T.sub.ar).
Dependencies are inferred from the claim text.