Methods and apparatus for an encoder
First Claim
Patent Images
1. An integrated circuit capable of receiving a first input signal and a second input signal, comprising:
- a first filter configured to compute a first quadrature of the first input signal;
a second filter configured to compute a second quadrature of the second input signal;
a first phase estimation circuit coupled to an output terminal of the first filter and configured to estimate a first phase according to the first input signal and the first quadrature;
a second phase estimation circuit coupled to an output terminal of the second filter and configured to estimate a second phase according to the second input signal and the second quadrature; and
a phase offset circuit coupled to the output terminals of the first and second phase estimation circuits and configured to compute a phase offset based on the first and second phases.
3 Assignments
0 Petitions
Accused Products
Abstract
Various embodiments of the present technology comprise a method and apparatus for an encoder. In various embodiments, the encoder is configured to remove impairments from the signals produced by a servo motor and compute a phase that is used to determine the rotary position of the servo motor. In various embodiments, the encoder is configured to remove a DC offset, improve amplitude mismatch, and compute a phase offset.
24 Citations
19 Claims
-
1. An integrated circuit capable of receiving a first input signal and a second input signal, comprising:
-
a first filter configured to compute a first quadrature of the first input signal; a second filter configured to compute a second quadrature of the second input signal; a first phase estimation circuit coupled to an output terminal of the first filter and configured to estimate a first phase according to the first input signal and the first quadrature; a second phase estimation circuit coupled to an output terminal of the second filter and configured to estimate a second phase according to the second input signal and the second quadrature; and a phase offset circuit coupled to the output terminals of the first and second phase estimation circuits and configured to compute a phase offset based on the first and second phases. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A method for computing a motor position, comprising:
- decimating a first input signal and a second input signal;
computing a first quadrature of the first signal;
computing a second quadrature of the second input signal;
computing a first phase according to the first quadrature;
computing a second phase according to the second quadrature;
computing a phase offset based on the computed first and second phases; and
computing the motor position based on the phase offset, the first phase, and a frequency. - View Dependent Claims (11, 12, 13)
- decimating a first input signal and a second input signal;
-
14. A system capable of generating a first signal and a second signal, comprising:
a motor assembly comprising; a motor having a motor position; and an optical encoder coupled to the motor and comprising; a first correction circuit configured to; apply a first gain to the first and second signals; apply a first DC offset correction to the first and second signals; generate first channel data; and generate second channel data; a second correction circuit coupled to an output terminal of the first correction circuit and configured to; apply a second gain to the first and second channel data; apply a second DC offset correction to the first and second channel data; generate corrected first channel data; and generate corrected second channel data; a signal processing circuit coupled to the second correction circuit and configured to; compute a first quadrature of the corrected first channel data; compute a second quadrature of the corrected second channel data; estimate a first phase according to the first signal corrected first channel data and the first quadrature; estimate a second phase according to the corrected second channel data and the second quadrature; and compute a phase offset based on the first and second phases. - View Dependent Claims (15, 16, 17, 18, 19)
Specification