simulation single_run debugger
Provides both graphical and tabular feedback on how hard Adams View is working to simulate your model. For example, during a simulation, the Simulation Debugger provides a table of those objects with the greatest simulation error.
Format:
simulation single_run debugger |
|---|
enable_debugger = | on /off |
track_model_element = | SSIM_ELEMENT |
show_table = | yes /no |
highlight_objects = | yes/no |
step_size_measure = | on /off |
iterations_per_step_measure = | on/off |
integrator_order_measure = | on/off |
static_imbalance_measure = | on/off |
Example:
simulation single_run debugger & |
|---|
enable_debugger = | on & |
track_model_element = | error & |
show_table = | yes & |
highlight_objects = | no & |
step_size_measure = | on & |
iterations_per_step_measure = | off & |
integrator_order_measure = | on & |
static_imbalance_measure = | on |
Description:
Parameter | Value Type | Description |
|---|
enable_debugger | On_off | Enables or disables the debugger |
track_model_element | Ssim_element | Sets the track |
show_table | Boolean | Shows/hides the debug table |
highlight_objects | Boolean | Highlights (or turns highlighting off for) those objects experiencing the most error or the most change, force, or acceleration, depending on the element you select to track |
step_size_measure | On_off | Displays the integrator step size (units of model time), as the simulation progresses, on a logarithmic scale. |
iterations_per_step_measure | On_off | Displays the number of iterations that Adams Solver needed to successfully progress to the next integration time step, over the course of a simulation |
integrator_order_measure | On_off | Displays the order of the polynomial that Adams Solver uses during the predictor phase of integration. |
static_imbalance_measure | On_off | Displays the current imbalance in the equilibrium equations that Adams Solver computes during a static equilibrium simulation. |
Extended Definition:
1. The Simulation Debugger can also highlight trouble areas during a simulation and provide measures of integrator progress, such as step size and integrator order.
The graphical and tabular feedback helps you determine:
■Which modeling elements (forces, constraints, and so on) are causing numerical difficulties. Often, the information directly points out modeling elements that you should change. You should always carefully inspect any modeling elements to which the Simulation Debugger calls attention.
■What simulation events are causing numerical difficulties. For example, if your model simulates fine until there is an impact between two parts, you should closely monitor simulation performance before, during, and after the impact.
2. Set to track (for the track_model_element parameter)
■Error - Track objects with the largest equation residual error. This number is an indicator of how far Adams Solver is from a solution. It should decrease with every iteration.
■Force - Track objects generating the greatest force. Includes forces and constraints.
■Change - Track variables with the most change.
■Acceleration - Track objects experiencing the greatest acceleration. Includes only parts.
3. The debug table, which contains a running count of the iterations needed to solve the equations of motion for the current simulation. You can use the information as a measure of how many computations Adams Solver is performing.
4. The step size strip chart provides useful information for debugging a model because, in general, the integrator step size becomes much smaller in response to rapidly changing dynamics. Rapidly changing dynamics are, in some cases, intentional (for example, contacts that engage or disengage over a short duration), but can often be a symptom of modeling errors. For example, they can indicate that there is an incorrect damping values in an IMPACT function that causes unrealistically high forces. It also can indicate the use of discontinuous function expressions, such as an IF function.
5. The Iterations per Step strip chart displays the number of iterations that Adams Solver needed to successfully progress to the next integration time step, over the course of a simulation. These iterations occur during the corrector phase of the integration.
The information in the Iterations per Step strip chart can provide you with several insights into your model:
■If your simulation progresses with very few iterations at each time step, Adams View is having an easy time simulating your model. You can further increase performance or speed by increasing the allowed maximum time step.
■If Adams Solver requires many iterations for any particular step, it is likely encountering a period of rapidly changing dynamics that can require corrective action as described for the Step Size strip chart explained in the previous section.
If you notice that Adams View requires many iterations right from the beginning of a simulation, it is likely that you have chosen an integration step size that is too large for the dynamics in your model. You can obtain better performance if you choose a smaller time step.
6. Adams Solver uses a polynomial to predict the future value of the state variables in an Adams model. In general, lower order polynomials are required to successfully integrate more difficult portions of a simulation, characterized either by nonlinearities or rapidly changing dynamics. Similar to the Iterations per Step strip chart, if the Integrator Order strip chart shows consistent use of high-order (three or more) polynomials, you may be able to increase performance by increasing the maximum allowed time step. If Adams Solver consistently or periodically uses low-order polynomials, it is symptomatic of a period of rapidly changing dynamics that may require corrective action as described for the Step Size strip chart or the integration step size may be too large for the dynamics in your model.
7. A static equilibrium simulation is an iterative process to compute a position in which your model assumes a minimum energy configuration The Static Imbalance strip chart displays a measure of how close the solution is coming to a complete balance of the equilibrium equations at each equilibrium iteration, in units of your selected force units. You need to select Update Every Iteration to watch the iteration-by-iteration progress of an equilibrium simulation
Cautions:
1. Note that selecting highlighting of objects will significantly slow down your simulation.