Summary

This blog explains common pitfalls and correct methods for estimating angular velocity from quadrature encoders. It shows the trade-offs between count-difference and period-measurement approaches and gives practical firmware techniques to compute stable, low-latency velocity for motor control.

Key Takeaways

• Choose between time-based (period) and position-difference (delta-count) methods depending on speed range and latency requirements.
• Account for quantization, sampling aliasing, and measurement jitter when differentiating encoder counts.
• Apply appropriate filtering (e.g., exponential/alpha filters or complementary filters) to reduce noise without introducing unacceptable lag.
• Use hardware timer capture and interrupt strategies correctly to get precise timestamping and avoid missed pulses.
• Test velocity algorithms across the full speed range and edge cases (low speed, direction changes, and stoppage) to reveal estimation failures.

Who Should Read This

Firmware and control engineers with some embedded experience who need reliable encoder-based velocity estimates for motor control or sensor interfacing.

Still RelevantIntermediate

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