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 an incident or a warning is detected by the kinematics solver in the following situations:

  • 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: A kinematics scenario computation, a preview, or a mechanism's animation must have been launched.
Related Topics
More about Singularities

  1. To access the computation report, select one of the following:

    • If you executed a kinematics simulation, click Incident Diagnosis or double-click the diagnosis directly in the specification 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 specification tree under the result of 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.

    The cause of the incident or the warning is described.

  3. Click Close.

Examples of Incidents and Warnings

Three types of incidents or warnings can be detected by the Kinematics solver:

Bifurcation Singularity Area Detection
If a bifurcation singularity area is detected, the following message is displayed:
 
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 an upper or lower limit for a command or for any controlled value that belongs to an engineering connection, the following message is displayed:
 The upper limit 20mm for Revolute.1 is reached.
Target Value Not Reached by the Kinematics Solver
If the kinematics solver did not 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 the above example, the mechanism includes three commands: Command 1, Command 2, and Command 3. The solver is called with a target value set to 10mm for command 1 and 20mm for command 2; command 3 is unconstrained and free (choosen freely by the solver). The kinematics solver reached the target value for command 2 but it failed to reach the target value for command 1; it converged to the nearest valid value (7mm instead of 10mm). In this example, the kinematics solver might have 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 due to a lock-up singularity that occured 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.