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| Code Block | ||||
|---|---|---|---|---|
| ||||
void constructProperties()
{
constructProperty_results_directory("results");
constructProperty_model_filename("flippinfelines_*FILL THIS IN*.osim");
constructProperty_num_optim_spline_points(20);
constructProperty_anterior_legs_down_weight(1.0);
constructProperty_posterior_legs_down_weight(1.0);
constructProperty_sagittal_symmetry_weight(1.0);
constructProperty_use_coordinate_limit_forces(true);
constructProperty_initial_parameters_filename("");
} |
A sample
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input file
Below is what the XML serialization of this class looks like. This is exactly what we meant by the optimizer_setup_file.xml above. This is a simplified version of what's generated by the executable optimize_input_template, which is generated from optimize_input_template.cpp. We've given you this file, but we do not discuss it in this tutorial.
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| Code Block | ||||
|---|---|---|---|---|
| ||||
/**
* Finds a control input history that achieves certain desired features
* of a cat's flipping maneuver, as determined by the objective function.
* The control of the system is performed via a PrescribedController that
* uses a spline for all actuators.
*
* Parameters are ordered by actuator, then by spline point index for a
* given actuator. Parameters are nondimensionalized by the min or max
* control values for the associated actuator.
* */
class FlippinFelinesOptimizerSystem : public SimTK::OptimizerSystem {
public:
FlippinFelinesOptimizerSystem(OpenSim::FlippinFelinesOptimizerTool & tool) :
_tool(tool),
_duration(1.0),
_objectiveCalls(0),
_objectiveFcnValueBestYet(SimTK::Infinity),
{
// Parse inputs & prepare output
// --------------------------------------------------------------------
// ********** PART C.1 **********
// Add a controller to the model to control theits actuators
it has // --------------------------------------------------------------------
// ********** PART C.2 **********
// Set parameter limits/bounds for the optimization.
// --------------------------------------------------------------------
// ********** PART C.3 **********
}
SimTK::Vector initialParameters()
{
// ********** PART C.4 **********
}
/**
* Defines desired features for the cat model's flip. Each call to this
* function updates the model's control, runs a forward dynamic simulation
* with this control, computes the objective value resulting from the
* simulation, and saves the results to output.
* */
int objectiveFunc(const SimTK::Vector & parameters, bool new_parameters,
SimTK::Real & f) const
{
// ...
// Unpack parameters into the model (i.e., update spline points)
// --------------------------------------------------------------------
// ********** PART C.5 **********
// Run a forward dynamicsdynamic simulation
// --------------------------------------------------------------------
// ********** PART C.6 **********
// Construct the objective function, term by term
// --------------------------------------------------------------------
// ********** PART C.7 **********
// Update the log and outputs with the objective function value
// --------------------------------------------------------------------
// ********** PART C.8 **********
}
// Miscellaneous functions (used, but uninteresting)
// ------------------------------------------------------------------------
// ********** PART C.10 **********
private:
// Objective function terms
// ------------------------------------------------------------------------
// ********** PART C.7 **********
// Member variables
// ------------------------------------------------------------------------
// ********** PART C.9 **********
}; |
TODO why you would look at the member variables section.
C.1
...
: Parse inputs and prepare output
C.2: Add a controller to the model to control its actuators
C.3: Set parameter limits/bounds for the optimization
C.4: Initial parameters
C.5: Unpack parameters into the model
C.6: Run a forward dynamic simulation
TODO MUTABLES
TODO talk about controls
TODO talk about how the parameters work.
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