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Simulate Trajectory

In one sentence: Animate the robot moving through every waypoint in a trajectory, computing joint angles via inverse kinematics at each step.

Overview

Workbench: Robot
Menu: Robot → Simulate Trajectory
Shortcut: none

Deprecated workbench

The Robot workbench is deprecated as of FreeCAD 1.0.

Opens the Trajectory Simulate task panel. Playback controls let you play, pause, step, and scrub through the trajectory. The robot's visual model updates in real time. If any waypoint is kinematically unreachable, simulation halts at that waypoint with an error.

Intuition

Simulate Trajectory is the "Play" button for robot programming. It checks whether the robot can actually reach all the waypoints you defined, visualises the motion, and catches kinematic problems before you send code to a real robot.

When to use it

  • After creating a trajectory, to verify reach, clearance, and joint limits.
  • Before generating KRL export code, to confirm the program is correct.

Step-by-step

  1. Select a Robot::RobotObject and a Robot::TrajectoryObject (or Robot::TrajectoryCompoundObject).
  2. Choose Robot → Simulate Trajectory.
  3. The Simulate task panel opens.
  4. Click Play to run the simulation.
  5. Use Step forward/backward to inspect individual waypoints.
  6. If an error occurs, the waypoint index is shown — check that waypoint's position in the workspace.

Simulation controls

Control Action
Play Run animation from current position to end
Stop Pause playback
Step forward Advance one waypoint
Step backward Go back one waypoint
Speed slider Adjust playback speed

Common mistakes and pitfalls

Simulation stops with kinematic error

Cause: A waypoint is outside the robot's reachable workspace or exceeds joint limits.
Fix: Reposition the waypoint closer to the robot, or adjust the robot's base placement. Check DH parameters and joint limits.

Python API

import FreeCADGui as Gui
Gui.doCommand("Gui.runCommand('Robot_Simulate', 0)")

See also