QuadLab: Free Quadruped Robot Simulator and Gait Trainer

Simulate a quadruped robot online, tune servo joints and gaits, test terrain and obstacles, and generate Arduino, ESP32, or Raspberry Pi motion code.

What this tool does

QuadLab is an interactive quadruped locomotion simulator for exploring a four-legged robot design in a browser. Configure two to five degrees of freedom per leg, add auxiliary joints, set servo channels and calibration limits, and watch the robot move through a simulated world. Adjust gait timing and speed, navigate between targets, test flat or uneven terrain, place obstacles, and review virtual training scores. The code panel generates servo trajectory examples for supported Arduino-compatible boards and Raspberry Pi.

Who this is for

• Robotics students learning quadruped gait and inverse-kinematics concepts
• Hobbyists prototyping a robot dog or legged robot servo layout
• Developers exploring PCA9685 channel mapping and motion-code structure
• Educators demonstrating gait timing, terrain, contact, and obstacle scenarios

How to use this tool

1. In Build, choose joints per leg and optional auxiliary joints; review each servo channel, neutral position, direction, angle limits, and pulse range.
2. In Motion, choose a gait, terrain, speed, cadence, and navigation behavior, or drive with the on-screen controls and keyboard.
3. Drag the scene to orbit the camera and scroll to zoom. Use the A and B buttons to place route targets and the plus button to add a test obstacle.
4. In Train, run virtual gait evaluations and review the episode scores before applying a candidate to the simulated robot.
5. In Code, choose a supported target and export or copy the generated motion example. Project settings can be saved to or loaded from a JSON file using the project controls.

Inputs

Inputs include robot dimensions, joint count, servo model and PCA9685 channel assignments, angle and pulse calibration values, gait, terrain, step timing, speed, foot clearance, navigation targets, and obstacles. Keyboard driving uses W/S for forward and reverse, A/D for sideways movement, Q/E for turning, and Space to start or pause.

Outputs and limitations

The simulator displays a live canvas-based robot and world, route and contact indicators, joint-limit and collision feedback, and virtual training metrics. Its Code panel generates Arduino C++ or Raspberry Pi Python servo trajectories, and the project controls can export/import configuration JSON. The scene and training are software simulations only: this page does not connect to, sense, or control a physical robot, and simulated obstacle avoidance is not hardware safety protection. Generated trajectories are open-loop commands without onboard navigation, contact sensing, collision sensing, torque or thermal limits, or balance control. Verify pin mapping, mechanical travel, power, emergency stop, and code on your specific hardware; test with the robot lifted and clear of people and objects.

Example use cases

• Compare trot timing and foot clearance on flat ground and step-like terrain
• Prototype a 12-servo quadruped layout and inspect PCA9685 channel assignments
• Explore how obstacles and target placement affect a simulated walking route
• Generate a starting point for Arduino/ESP32 or Raspberry Pi gait experiments

Frequently asked questions