/// <summary>
/// Construct a PID with parameters p, i and d.
/// </summary>
/// <param name="p"></param>
/// <param name="i"></param>
/// <param name="d"></param>
public PID(float p, float i, float d)
{
Name = "Unnamed";
P = p;
I = i;
D = d;
_prevError = new ErrorSample(float.NaN, 0);
}
/// <summary>
/// Construct a PID with parameters p, i and d.
/// </summary>
/// <param name="p"></param>
/// <param name="i"></param>
/// <param name="d"></param>
public PID(float p, float i, float d)
{
Name = "Unnamed";
P = p;
I = i;
D = d;
_prevError = new ErrorSample(float.NaN, 0);
}
public MainWindow()
{
InitializeComponent();
CurrentDataContext = new MainViewModel(delegate(double aError)
{
errorChart.ErrorStat.Add(ErrorSample.Generate(aError));
});
DataContext = CurrentDataContext;
}
/// <summary>
/// Call this method (only once) before each call to compute methods.
/// Note that this method should only be called for each main loop cycle, so make sure to not run Compute() more than once in the loop for each PID.
/// </summary>
/// <param name="error"></param>
/// <param name="totalTicks">TimeSpan ticks (100ns).</param>
private void UpdateDifferentialAndIntegralErrors(float error, long totalTicks)
{
long ticksDelta = totalTicks - _prevError.TotalTicks;
// Avoid division by zero
if (ticksDelta > 0)
{
var elapsedSeconds = (float)TimeSpan.FromTicks(ticksDelta).TotalSeconds;
if (float.IsNaN(_prevError.Value))
{
_prevError.Value = error;
}
_differentialError = (error - _prevError.Value) / elapsedSeconds;
_integralError += (error * elapsedSeconds);
}
// Remember error for next timestep
_prevError = new ErrorSample(error, totalTicks);
}
/// <summary>
/// Call this method (only once) before each call to compute methods.
/// Note that this method should only be called for each main loop cycle, so make sure to not run Compute() more than once in the loop for each PID.
/// </summary>
/// <param name="error"></param>
/// <param name="totalTicks">TimeSpan ticks (100ns).</param>
private void UpdateDifferentialAndIntegralErrors(float error, long totalTicks)
{
long ticksDelta = totalTicks - _prevError.TotalTicks;
// Avoid division by zero
if (ticksDelta > 0)
{
var elapsedSeconds = (float) TimeSpan.FromTicks(ticksDelta).TotalSeconds;
if (float.IsNaN(_prevError.Value)) _prevError.Value = error;
_differentialError = (error - _prevError.Value)/elapsedSeconds;
_integralError += (error*elapsedSeconds);
}
// Remember error for next timestep
_prevError = new ErrorSample(error, totalTicks);
}
