| 摘要 |
Signal processing apparatus, e.g. a resolver-to-digital converter (30), converts an analogue input, e.g. sinusoidal signals such as resolver signals Vsin, Vcos, into a digital output, e.g. an angular position and angular speed for a rotor. A first processing unit (31), e.g. a quadrature encoder, monitors the input at a first resolution to produce a first tracking error e1 between the digital output and the analogue input, and a second processing unit (32), which e. g. samples the input signals and e.g. applies a sine cosine function or an arctan function, monitors the input at a second resolution higher than the first resolution to produce a second tracking error e2 between the digital output and analogue input. The apparatus determines the digital output based on the first or second tracking error, e.g. through processing with a filter (33), and includes a switch (34) for switching between the two errors so as to promote tracking stability. Switching may for example be based on a comparison of the first error signal e1 with a threshold value, e.g. a maximum error value. |
