33 lines
928 B
Markdown
33 lines
928 B
Markdown
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---
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title: Measuring Wheel Speed
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summary: Convert encoder counts over time into rotational speed for a drive wheel.
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chapter: Using Encoder Feedback
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order: 1
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tags:
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- speed
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- odometry
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- robotics
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estimated_minutes: 9
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---
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# Measuring Wheel Speed
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Position counts become useful control signals once you add time.
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To estimate wheel speed:
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1. sample the encoder count at a fixed interval
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2. subtract the previous count from the current count
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3. divide by the sample period
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4. convert counts per second into revolutions per second or wheel surface speed
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## Why this matters
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Speed feedback is the bridge between open-loop motor commands and predictable robot motion.
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If two drive motors get the same PWM value but spin at different speeds, your robot will drift. Encoder-based speed estimation lets you detect and correct that mismatch.
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## Checkpoint
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Plot wheel speed over time while ramping the motor command up and down.
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