Control techniques for motor driven systems
AssigneeAnalog Devices, Inc.
InventorsColin LYDEN, Javier CALPE-MARAVILLA, Mark MURPHY, Eoin ENGLISH, Denis Martin O'CONNOR
Life of this patent
Estimating the term…
Abstract
A drive signal for a motor-driven mechanical system has zero (or near zero) energy at an expected resonant frequency of the mechanical system. These techniques not only generate a drive signal with substantially no energy at the expected resonant frequency, they provide a zero-energy “notch” of sufficient width to tolerate systems in which the actual resonant frequency differs from the expected resonant frequencies.
Claims9
A method of driving a motor-driven mechanical system, comprising:
- responsive to a codeword identifying a destination position of the mechanical system, generating a multi-step drive signal, each step offset from a neighboring step by a time tC:
- t
- c
- ≅
- 1
- 2
-
- f
- R
- where fR is an expected resonant frequency of the mechanical system,
- wherein an amplitude of each step is derived from a selected row of Pascal's triangle and a difference between the destination position and the start position.
A method of driving a motor-driven mechanical system, comprising:
- responsive to a codeword identifying a destination position of the mechanical system, generating a stepped drive signal in a plurality of intervals, each interval offset occurring from a neighboring interval by a time tC:
- t
- c
- ≅
- 1
- 2
-
- f
- R
- where fR is an expected resonant frequency of the mechanical system,
- wherein each step has a uniform amplitude and a number of steps within each interval is derived from a selected row of Pascal's triangle.
A method for generating a drive signal to a motor-driven mechanical system, comprising:
- applying a drive signal to the motor-driven mechanical system in a series of steps, wherein:
- the number of steps are dependant on a distance to be traversed by the motor-driven mechanical system, and
- the drive signal causes the motor-driven mechanical system to traverse the distance in a predetermined time tp that is independent of the distance.
A drive signal generator, comprising:
- a ramp modulator, responsive to a step clock rate and a net distance, to generate a step response signal;
- an accumulator, responsive to the step response signal, to generate a stepped drive signal;
- and
- a digital to analog converter to generate a drive signal,
- wherein the drive signal causes a motor-driven mechanical system to traverse the net distance in a predetermined time that is independent of the net distance.
A method of driving a motor-driven mechanical system, comprising:
- generating a drive signal,
- notch limit filtering the drive signal at a frequency corresponding to an expected resonant frequency of the mechanical system, wherein the filtering is performed by a plurality of notch limit filters in cascade, and
- applying the filtered drive signal to a motor of the mechanical system.
Dependencies are inferred from the claim text.