RTDE speedL Rotational behavior

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Found 40 results for 'speedL RTDE rx ry rz behavior rotation angle-axis representation order:latest status:public'

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Found 39 results for 'speedL rotation rates rx ry rz angle-axis constant speed order:latest status:public'

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Reading: Rotation Speed in speedl()

Based on the thread “Rotation Speed in speedl”:

  1. The rotational components [rx, ry, rz] provided to the speedl() function represent a rotation vector (in axis-angle representation). Universal Robots primarily operates using rotation vectors in their orientation representation.

  2. The rotation vector is defined with respect to the robot’s base frame, not the tool frame. So, the rotational velocity aligns with the base coordinate system.

Insights from Tests:

  • When you input a rotation vector into speedl([0, 0, 0, 0.5, 0.5, 0.5], 0.2), the vector [0.5, 0.5, 0.5] was treated as an angular velocity vector (in axis-angle space).
  • The thread verified through simulation (using the UR Log Viewer) that this input corresponded to a resultant angular speed, where the rotation happened along the axis specified by the normalized rotation vector, with a speed proportional to its magnitude.

Note:

The outcome from speedl() might not intuitively produce changes isolated to a single rotational axis unless the provided vector strictly corresponds to that direction. For example:

  • A value such as [0, 0, π/2] might create coupling effects since the axis-angle representation is sensitive to its normalization and frame reference.

This explanation clarifies the inconsistency you observed when all three orientation components (rx, ry, and rz) were affected in your test. It is highly probable that your rotation vector parameter inherently included some implicit coupling due to its base frame reference.

Would you like guidance on formulating your linear and angular speeds for the precise trajectory between Pose 1 and Pose 2?