The Pin robot is a virtual quadrupedal model developed within the PinPort browser-based simulator. It features a design inspired by the Unitree Go1, utilizing twelve virtual servos controlled via a PCA9685 PWM controller. The robot's movement is powered by an Arduino Uno emulator, processing C++ code with 2 KB of RAM and a 16 MHz clock speed.
The robot uses inverse kinematics to manage its gait, specifically a trot pattern where diagonal pairs of legs move in sequence. At a step time of 0.25 seconds and a 10 cm step length, the robot achieves a speed of 35 cm/s. By reducing the step time to 0.15 seconds and increasing the length to 22 cm, the speed reaches 1.25 m/s, though the gait remains a fast trot rather than a full run.
Navigation is stabilized by an MPU6050 gyroscope, which adjusts leg movement to maintain a straight course. The developer notes that the robot can withstand lateral impacts of 8–10 N·s without active stabilization. Attempts to achieve a full gallop or higher jumps were limited by the simulated physical constraints of standard servos, which are rated at 10 rad/s and 20 N·m.
The project serves as a testing environment for robotics code, allowing users to experiment with parameters like step length and turning speed without the risk of damaging physical hardware. The developer emphasizes that while the simulator provides a valuable proof-of-concept, it does not guarantee identical performance on physical hardware due to differences in real-world friction and mechanical tolerances.
