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Lesson

Forward kinematics

How robots track their position in space and how Cyberwave visualizes it automatically.

Forward Kinematics answers a fundamental question: "Given the angles of all my robot's joints, where is the end of my robot arm?" This calculation is essential for visualization, collision detection, and coordinating sensors mounted on the robot.

What Is Forward Kinematics?

A robot arm is a chain of rigid segments (links) connected by joints. Each joint can rotate or slide, and the combination of all joint positions determines where the gripper or tool ends up.

Revolute joints rotate around an axis—like your shoulder or elbow. Prismatic joints slide along an axis—like a linear rail.

Forward Kinematics (FK) takes the current joint angles and calculates the position and orientation of the end-effector (the gripper, tool, or camera at the end of the arm).

Why It Matters

FK is the foundation for several critical capabilities:

  • Visualization: Showing a 3D model of the robot that matches its real-world pose
  • Collision checking: Knowing where the robot is so you can detect potential collisions
  • Sensor fusion: A camera mounted on the arm moves with it—FK tells you exactly where it was pointing when it captured an image

Without accurate FK, your digital twin doesn't match reality, and any planning or safety systems built on top will be wrong.

The Traditional Approach

Building FK from scratch means:

  1. Parsing robot description files (URDF format)
  2. Building the mathematical chain of coordinate transforms
  3. Implementing the calculations for every joint type
  4. Creating visualization that updates in real-time
  5. Adding collision geometry for safety checks

This is weeks of specialized work before you can even see your robot move on screen.

How Cyberwave Helps

Cyberwave handles forward kinematics automatically when you upload a robot model.

Automatic Model Loading

Upload a URDF file (the standard robot description format) and Cyberwave builds the complete kinematic model. No manual configuration needed.

Real-Time Visualization

Stream joint positions from your robot and see it move in the browser. The 3D view updates in real-time, showing exactly what the physical robot is doing. No plugins or local software required.

Built-In Collision Checking

Cyberwave uses the kinematic model to check whether planned motions will cause collisions—with the environment or with the robot itself. Problems are caught in simulation before they damage hardware.

Sensor Transforms

Cameras and sensors mounted on the robot automatically have their positions tracked. When a camera captures an image, Cyberwave knows exactly where it was in 3D space, enabling accurate mapping and object localization.

See It In Action

In your Cyberwave workspace, open the Simulation tab and use the joint sliders to move a robot. Watch the end-effector position update in real-time. This is the FK engine running in your browser—the same math that powers safety checks and motion planning.

For technical details, see the Cyberwave documentation.

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