Diagnosing Computation Incidents

To understand the kinematics solver's computation messages and review your mechanism accordingly, you can display a computation report using the Incident Diagnosis function.

You can access the computation report when the kinematics solver detects an incident or a warning. An incident or warning can be detected when:

  • Animating your mechanism using the Mechanism Player.
  • Previewing a kinematics scenario or reviewing the results of a kinematics scenario using the Simulate and Generate Results function.
  • Recording an excitation using the Excitation Recorder.

Before you begin: Run a kinematics scenario computation, a preview, or the animation of a mechanism.
See Also
About Singularities
  1. To access the computation report, select one of the following:
    • If you executed a kinematics simulation, from the Scenario section of the action bar, click Incident Diagnosis or double-click the diagnosis directly in the tree.

      The Incident Diagnosis dialog box appears.

    • If you preview a kinematics scenario, animate a mechanism, or record an excitation, click .

      The Messages Reporting immersive dialog box appears.

    If an incident or warning is detected, a dialog box provides you with detailed messages that describe the cause of the incidents or warnings. The computation report also appears in the tree under the result of the scenario and is stored with the simulation when you propagate the kinematics scenario.
  2. Select a line to access the details of an incident or a warning.
  3. Click Close.

Examples of Incidents and Warnings

The Kinematics solver can detect three types of incidents or warnings:

Bifurcation Singularity Area Detection
If a bifurcation singularity area is detected, the following message appears:
 
A bifurcation singularity area was occurred.
The mechanism entered or left a bifurcation singularity area. 
At crossing this area, the solver arbitrarily selects a configuration 
among several valid configurations.
Engineering Connection Limits Reached
If the kinematics solver reaches the upper or lower limit of a command, or any controlled value belonging to an engineering connection, the following message appears:
 The upper limit 20mm for Revolute.1 is reached.
Target Value Not Reached by the Kinematics Solver
If the kinematics solver cannot reach the target value, the following message appears:
The kinematics solver did not reach the target. 
Solver's input:
Command 1 = 5mm -> Target value = 10mm.
Command 2 = 0mm -> Target value = 20mm.
Command 3 = 0mm, free.
Solver's result:
Command 1 = 7mm, Target value not reached.
Command 2 = 20mm, Target value reached.
Command 3 = 0mm, free.

In this example, the mechanism includes three commands with specified target values:

Command Target Value
Command 1 10mm
Command 2 20mm
Command 3 unconstrained and free (value chosen by the solver)

The kinematics solver reaches the target value for Command 2 but fails to reach the target value for Command 1. It reaches instead the highest valid value (7mm instead of 10mm). In this example, the kinematics solver encountered a lock-up singularity, preventing it from reaching the target value.

Important: In most cases, if the kinematics solver fails to reach a target value, it is because of a lock-up singularity that occurred during the computation. In this situation, the kinematics solver attempts to reach an intermediate position (the closest position to the target value that was initially specified).

Note: When an incident or a warning is detected when running the preview or simulating and generating results, a time value is added to the initial message.
The kinematics solver did not reach the target at t=5s.