Introduction to Robotics
Why?
Why robots need feedback to move accurately
Why can't a robot arm just follow its motor commands blindly?
Quick check · tap an answer to continue
Lesson notes
Key points
- Because real motors face friction, changing loads and wear, the same command does not always produce the same motion.
- Because errors like these build up, an open-loop system, one that never measures its output, drifts further from the target over time.
- Because sensors such as encoders measure the actual position, a controller can subtract it from the target and correct the error continuously.
Definitions
- Open-loop control
- Control that sends commands without measuring the result, so errors go uncorrected.
Takeaway: So accurate robots measure their output and correct errors with feedback.
Quick check: What does a closed-loop controller use to correct a robot's motion?
- Faster motor speed
- Measured error from sensors
- A pre-recorded path only
It compares sensor measurements with the target and acts on the difference.
DisturbancesOpen-loop driftClosed loop
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