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US 6,084,376 AGranted
Low cost resolver system
AssigneeAspen Motion Technologies, Inc.
InventorsMartin Piedl, Moe Barani, Ron Flanary
Life of this patent
Estimating the term…
Abstract
A resolver (10) is excited with a high frequency signal from excitation circuit (16). Outputs of the resolver (10) are transmitted through receiver circuit (24) and input to a DSP signal processing circuit (18), which demodulates the sine and cosine outputs to provide samples of the sine and cosine of the rotor position. The sample values are converted to digital values, which are used to calculate a shaft angular position, which is then used for closed loop position and velocity control of a brushless PM motor (14).
Claims10
A system for determining an angular position of a shaft of a motor, comprising:
- a reluctance resolver coupled to said shaft, said resolver including a sine output winding, a cosine output winding, and an excitation input winding;
- a signal processing system electrically connected to receive signals from said sine output winding and said cosine output winding, respectively;
- a driver under control of said signal processing system for transmitting excitation signals to said excitation input winding;
- wherein said signal processing system synchronizes the receiving of signals from the sine output winding and the cosine output winding, respectively, with the excitation signals transmitted to the excitation winding, so as to sample modulation envelope values of the signals from the sine output winding and the cosine output winding, respectively;
- wherein said signal processing system calculates the angular position of said shaft from said respective modulation envelope values;
- and
- wherein in calculating said angular position, said signal processing system calculates an estimated position from the sine and cosine signals and applies a correction value to said estimated position from stored error data for said estimated position.
4 more elements
A system for determining an angular position of a shaft of a motor, comprising:
- a reluctance resolver coupled to said shaft, said resolver including a sine output winding, a cosine output winding, and an excitation input winding;
- a signal processing system electrically connected to receive signals from said sine output winding and said cosine output winding, respectively;
- a driver under control of said signal processing system for transmitting excitation signals to said excitation input winding;
- wherein said signal processing system synchronizes the receiving of signals from the sine output winding and the cosine output winding, respectively, with the excitation signals transmitted to the excitation winding, so as to sample modulation envelope values of the signals from the sine output winding and the cosine output winding, respectively;
- wherein said signal processing system calculates the angular position of said shaft from said respective modulation envelope values;
- and
- wherein said motor is a brushless, permanent magnet motor, and wherein said system further includes a commutation switch connected to said motor and a sine wave commutation signal generator for transmitting sine wave commutating signals to said commutation switch.
4 more elements
A system for determining an angular position of a shaft of a motor, comprising:
- a reluctance resolver coupled to said shaft, said resolver including a sine output winding, a cosine output winding, and an excitation input winding;
- a signal processing system electrically connected to receive signals from said sine output winding and said cosine output winding, respectively;
- a driver under control of said signal processing system for transmitting excitation signals to said excitation input winding;
- wherein said signal processing system synchronizes the receiving of signals from the sine output winding and the cosine output winding, respectively, with the excitation signals transmitted to the excitation winding, so as to sample modulation envelope values of the signals from the sine output winding and the cosine output winding, respectively;
- wherein said signal processing system calculates the angular position of said shaft from said respective modulation envelope values;
- and
- wherein said signal processing system includes a shaft velocity signal generator and wherein the signal processing system generates a shaft angular position output signal as one input to said shaft velocity signal generator, and wherein said shaft velocity signal generator is responsive to said shaft angular position output signal and a speed command to produce an error signal and to transmit said error signal to said shaft velocity signal generator.
4 more elements
A method for determining an angular position of a shaft of a motor, comprising:
- generating output signals from a reluctance resolver coupled to said shaft, said resolver including a sine output winding, a cosine output winding, and an excitation input winding, wherein said output signals are generated from said sine output winding and said cosine output winding as respective pulse trains modulated by a sine wave envelope and a cosine wave envelope, respectively,
- transmitting excitation signals to said excitation input winding at a predetermined frequency;
- sampling values from said sine wave envelope and said cosine wave envelope at said predetermined frequency and synchronized to the transmitting of the excitation signals;
- calculating said angular position from the values sampled from the sine wave envelope and the cosine wave envelope;
- and
- in calculating said angular position, an estimated position is calculated;
- and
- further comprising the step of applying a correction value to said estimated position from stored error data for said estimated position.
5 more elements
A method for determining an angular position of a shaft of a motor, comprising:
- generating output signals from a reluctance resolver coupled to said shaft, said resolver including a sine output winding, a cosine output winding, and an excitation input winding, wherein said output signals are generated from said sine output winding and said cosine output winding as respective pulse trains modulated by a sine wave envelope and a cosine wave envelope, respectively,
- transmitting excitation signals to said excitation input winding at a predetermined frequency;
- sampling values from said sine wave envelope and said cosine wave envelope at said predetermined frequency and synchronized to the transmitting of the excitation signals;
- calculating said angular position from the values sampled from the sine wave envelope and the cosine wave envelope;
- and
- wherein said motor is a brushless, permanent magnet motor, and
- further comprising the step of commutating signals to be applied to said motor;
- and
- further comprising transmitting sine wave commutating signals to control said commutating signals to be applied to said motor.
6 more elements
A method for determining an angular position of a shaft of a motor, comprising:
- generating output signals from a reluctance resolver coupled to said shaft, said resolver including a sine output winding, a cosine output winding, and an excitation input winding, wherein said output signals are generated from said sine output winding and said cosine output winding as respective pulse trains modulated by a sine wave envelope and a cosine wave envelope, respectively,
- transmitting excitation signals to said excitation input winding at a predetermined frequency;
- sampling values from said sine wave envelope and said cosine wave envelope at said predetermined frequency and synchronized to the transmitting of the excitation signals;
- calculating said angular position from the values sampled from the sine wave envelope and the cosine wave envelope;
- and
- further comprising sensing a difference between a commanded velocity and an actual velocity and generating a velocity error signal as an input signal to at least partly control the transmitting of sine wave commutating signals.
3 more elements
Dependencies are inferred from the claim text.