Dog Like Otto Robot I PID Control and Face Expressions

🐶 DogLike Otto Robot – A Quadruped Otto Remix

DogLike Otto Robot is a fun and educational quadruped robot inspired by the original Otto DIY Robot, redesigned to behave like a small robotic dog.

This remix transforms the classic Otto into a four-legged robot with dog-like personality, capable of expressive movements and emotional interaction through a circular display.

The robot is powered by the RoboCore Vespa Board and uses two 3.7V Li-ion batteries (18650) connected in series to provide stable power for the electronics and servo motors.

To enhance interaction, a round GC9A01 display acts as the robot’s “face”, showing blinking eyes and emotional expressions while the robot moves.

The project combines PID-controlled servo motors, walking gaits, expressive animations, and interactive behaviors, creating an engaging platform for robotics learning, embedded systems experimentation, and educational demonstrations.

All code, firmware, and documentation are available here:
https://github.com/ThayAlms/DogLike-Otto-Robot

🏆 Section: Design Quality

The DogLike Otto Robot was designed with a focus on mechanical balance, smooth locomotion, and ease of assembly.

The quadruped structure distributes weight across four legs, improving stability compared to the classic biped configuration of the Otto DIY Robot.

Each structural component was modeled to ensure:

• proper servo alignment

• rigid mechanical connections

• balanced center of gravity

This results in stable walking gaits, reduced servo stress, and reliable performance during movement sequences.

🖨 Printability

All parts were designed specifically for easy FDM 3D printing.

Design considerations include:

• optimized flat surfaces for bed adhesion

• minimal need for supports

• clean servo mounting geometry

• easy-to-print orientations

Whenever possible, the model was divided into separate components, allowing users to print parts individually and reducing printing complexity.

Recommended settings:

• Layer height: 0.2 mm

• Infill: 15–20%

• Supports: not required for most parts

• Material: PLA or PETG

These choices ensure the model can be printed even on entry-level printers.

🐾 Features

🚶 Smooth Quadruped Walking

The robot walks forward using coordinated leg movements with PID-assisted servo control, producing smoother and more stable motion compared to simple positional control.

🪑 Sit Behavior

A stable sitting posture where the rear legs support the body while the front legs remain balanced.

✋ Give Paw Interaction

The robot lifts its front-right leg to simulate a friendly “give paw” gesture before returning to its neutral position.

🛏 Lie Down Mode

A gradual relaxation movement lowers the robot into a resting position.

😀 Emotional Display

The circular GC9A01 TFT display shows animated eyes and expressions, allowing the robot to communicate simple emotions such as happiness or blinking reactions.

⚙ PID-Controlled Legs

Each servo motor is stabilized using a simple PID controller, improving motion quality and reducing mechanical stress.

Controller parameters:

• Kp (Proportional Gain) – drives the servo toward the desired angle

• Kd (Derivative Gain) – dampens oscillations and prevents overshoot

This approach provides:

• smoother walking cycles

• reduced jerky movements

• more natural robotic motion

🛠 Assembly

🔩 Servos

Attach each servo motor to the printed structure using the screws included in the servo kit.

🐾 Feet

Secure the feet to the servo horns using screws or press-fit connections to improve ground traction.

📺 Display

Mount the GC9A01 display using M2 screws and nuts on the dedicated 3D-printed holder.

🔋 Batteries

Power the robot using two 18650 Li-ion batteries connected in series (~7.4V).
The Vespa board regulates the voltage required for both the control electronics and the display.

🎓 Educational Value

DogLike Otto is designed not only as a fun robot but also as a learning platform for robotics and embedded systems, covering topics such as:

• servo motor control

• PID algorithms

• quadruped locomotion

• expressive robot interfaces

• embedded programming

It is ideal for students, makers, and robotics enthusiasts who want to explore the fundamentals of interactive robotics.