Tutorial: Path Computation

This tutorial walks you through a typical scenario for computing a collision-free path planning. It is divided into a number of easy steps, which enable you to learn the basics of Assembly Path Optimization.

This task shows you how to:

Before you begin: The session data includes a Track in a PPR Context or in a Model Scenario Results (MSR).
See Also
About Path Planning
Path Finder Panel
Context Toolbars

Prepare the Track

  1. Select a Track, then click Path Planning in the Simulation section of the action bar.

    Recommendation: Work on a disassemble Track, that is, a Track where the moving object is removed from an assembly.

    The first and last points are defined as the default start and end points.
  2. Optional: Select a Track point (T-Point) and click Set Guiding Type in the context toolbar.
    The point is now defined as a guiding point, which means that the resulting Track will pass nearby this point.
  3. If your Track includes a start, end, or intermediate point in collision with the context, use the Extract command to replace it and create a new collision-free point.

    For more information, see Extracting a Collision Point.

Define the Parameters for the First Computation

  1. Open the Path Finder Parameters panel by clicking the Path Finder icon at the right edge of the work area.

    The Path Finder Parameters panel enables you to control, adjust, and monitor the operation of the path planning solver.

  2. Click the Domain and Rotation Limits tab.

    • In the Domain Limits area, select the Translation option.

      A bounding box appears. Its default limits are computed from the positions of the start, end, and intermediate points, and the positions and size of the moving objects. The Robot appears at the start point.

    • Optional: In the Angle Limits area, select the Bryant Angles option and define the angle limit values.

  3. Click the Find and Optimize tab.

    • Select the Visual feedback during computation option.
    • In the Find Track area:
      • Specify the quality to Low or Medium.
      • Clear the Extract points in collision before finding track option.

  4. Click the Multi-Clearance tab.

    • In the Global Clash Limit area, select Contact allowed from the list menu.

Compute a Collision-Free Path

  1. In the context toolbar of the Path Planning command, click Find Track .
    The Track is generated and only contains collision-free points.
  2. Click Play  at the center of the Compass to simulate the Track.

    Note: Click Play  again to exit the simulation.

Refine the Parameters for the Second Computation

  1. Open the Path Finder Parameters panel by clicking the Path Finder icon at the right edge of the work area.
  2. Click the Domain and Rotation Limits tab.

    • In the Domain Limits area, select the Guiding Path option.
      Note: The system automatically initializes the radius.
    • Optional: In the Angle Limits area, select the Bryant Angles option and modify the previous angle limit values to increase accuracy.

  3. Click the Find and Optimize tab.

    • In the Find Track area, specify the quality to High or Very High.

  4. Click the Multi-Clearance tab and refine clash limits according to the expected result.

    • Optional: In the Global Clash Limit area, use the list menu and select Clearance Required and precise the value as wanted.
    • Optional: In the Local Clash Limit area, define the local limits on the selected group of objects.

      For more information, see Using Collections and Local Clash Limits.

  5. If your Track includes a start, end, or intermediate point in collision with the context, use the Extract command to replace it and create a new collision-free point.

Recompute a Collision-Free Path

  1. In the context toolbar of the Path Planning command, click Find Track .
    The Track is generated and only contains collision-free points.
  2. Click Play  at the center of the Compass to simulate the Track.

    Note: Click Play  again to exit the simulation.

  3. Optional: Perform the Refine the Parameters for the Second Computation steps again, as many times as required to increase accuracy and achieve the expected results.

Optimize the Computed Path

  1. Set the path finder parameters to optimize the computed path:
    1. To open the Path Finder Parameters panel, click Path Finder at the right edge of the work area.
    2. In the Find and Optimize tab, specify the quality level of the Track in the Optimize Track area.

    Recommendation: Set the quality first to Medium to ensure a quick computation time. You can later refine the quality level to High or Very High.

  2. Click Optimize Track in the context toolbar of the Path Planning command.
    The Track is simplified and smoother. It has fewer points, and unnecessary rotations and motions are removed.
    Tip: You can execute this command several times to get an increasingly smooth Track.
  3. Click OK in the context toolbar to save the Track.