Robotics & Hardware · 2024 · prototype
Interactive Robotic Head
Articulated animatronic cybernetic head with multi-axis neck servos and optical sensor tracking.
01 / Overview
An expressive biomimetic robotic centerpiece combining multi-servo kinematics with real-time target tracking. Engineered to explore human-robot interaction through mechanical head orientation, eye ocular panning, and responsive visual gestures.
02 / Problem
Creating realistic mechanical human-robot interactions requires low-latency servo synchronization and mechanical balance to prevent neck oscillations during sudden acceleration.
03 / Contribution
Researched kinematic pan-tilt neck mechanism, 3D structural bracket assembly, servo torque budgeting, and microcontroller coordination for smooth interpolated motion.
04 / System architecture
Physical + hardware
- Multi-axis pan/tilt metal gear servo motors for pitch, yaw, and ocular movement
- Dedicated PCA9685 16-channel 12-bit PWM I2C servo controller board
- Ultrasonic distance array and camera sensor mount for interactive spatial awareness
- Regulated 5V 6A external power supply for high-stall servo currents
Firmware + software
- S-curve velocity profile generation in firmware to prevent mechanical jerk and servo gear wear
- Serial packet parser accepting directional orientation targets from host computer
- Emergency soft-limit bounds to prevent mechanical binding
Signal flowI2C communication bus between host MCU and PCA9685 PWM driver with separate high-amperage 5V bus and ground-plane tie.
05 / Engineering decisions
- 01Offloaded servo PWM generation from main MCU to dedicated hardware timer IC (PCA9685) to eliminate timing jitter.
- 02Implemented software acceleration smoothing curves to mimic organic head velocity.
06 / Results + constraints
Observed results
- Smooth 180-degree yaw and 60-degree pitch range with zero servo oscillation.
- Sub-50ms latency response to tracking coordinates sent over serial.
Current limitations
- Mechanical sound dampening is needed for quiet office operation.
- Jaw articulation mechanism is currently in prototyping stage.