Mechatronics

Template project: The technical details below are illustrative placeholders. They will be replaced with the real build log, measurements, photographs, and test data.

Abstract

This project explores a small animatronic head that tracks a person with two servo-driven eyes. The goal is to turn mechanical parts, sensors, and control code into a repeatable system that behaves predictably.

Design Question

How can a compact Arduino-based mechanism track a nearby person smoothly while remaining easy to calibrate, repair, and explain?

The design is divided into a sensor pipeline, a motion controller, and a printed mechanical assembly.

System Overview

Person Sensor → filtered target position → controller → servo motors
        └──────────────── diagnostics / serial logging ────────────────┘

Hardware

• Arduino-compatible controller
• Person-tracking sensor
• Two positional servos
• 3D-printed eye mounts and base
• External 5 V supply with a common ground

Control Loop

The controller samples the sensor, rejects incomplete readings, and moves each servo toward the most recent valid target. A deadband prevents constant hunting near center.

const float deadband = 0.04f;
const float response = 0.18f;

float updateAxis(float current, float target) {
  if (abs(target - current) < deadband) return current;
  return current + (target - current) * response;
}

Build Log

01 — Mechanical Prototype

Placeholder for: photographs of the first printed parts, fit notes, fastener sizes, and changes between versions.

MECHANICAL PROTOTYPE / PHOTO PLACEHOLDER

02 — Wiring And Calibration

Placeholder for: a wiring diagram, power measurements, pin assignments, and the calibration procedure.

03 — Motion Tuning

Placeholder for: logged target position versus servo position, overshoot observations, and final controller constants.

Test Plan

The finished page will include the setup, expected behavior, observed behavior, and raw data for every test.

Sensor Loss

Setup: Remove the target for five seconds.

Expected Result: The mechanism holds the last safe position.

Status: Placeholder.

Centering

Setup: Place the target at the center of the sensor's range.

Expected Result: Both axes settle without hunting.

Status: Placeholder.

Bounds

Setup: Move the target across the full range.

Expected Result: The servos remain inside their mechanical limits.

Status: Placeholder.

Endurance

Setup: Run the system for thirty minutes.

Expected Result: No reset, stall, or excessive heat.

Status: Placeholder.

Results And Next Steps

This section will hold measured results, failure modes, and the next hardware revision. The finished version should make the build reproducible without guesswork.

Files And References

• Repository: View the project on GitHub
• CAD And Print Files: To Be Added
• Firmware: To Be Added
• Test Data: To Be Added

Conclusion

The final write-up will show the decisions, failures, measurements, and revisions that made the object work.

Revision Checklist

• [ ] Add dated build entries.
• [ ] Add photographs with captions and alt text.
• [ ] Add the wiring diagram and CAD dimensions.
• [ ] Replace placeholder statuses with measured results.
• [ ] Link the final firmware commit.

Documentation Status: Draft Template.