Rate Conversion for Parameterized PID Blocks
For parameterization of continuous-time PID Controller and PID Controller (2-DOF)
blocks, you can independently specify the rate-conversion methods as discretization
formulas for the integrator and derivative filter. Each has the following options:
- Trapezoidal (default) — Integrator or derivative filter discretized as (Ts/2)*(z
+1)/(z-1), where Ts is the target sample time. - Forward Euler — Ts/(z-1).
- Backward Euler — Ts*z/(z-1).
For more information about PID discretization formulas, see “Discrete-Time Proportional-
Integral-Derivative (PID) Controllers” (Control System Toolbox).
For discrete-time PID Controller and PID Controller (2-DOF) blocks, you set the integrator
and derivative filter methods in the block dialog box. You cannot change them in the
Tuned Block Editor.
Rate Conversion for Other Parameterized Blocks
For blocks other than PID Controller blocks, the following rate-conversion methods are
available:
- Zero-order hold — Zero-order hold on the inputs. For most dynamic blocks this is
the default rate-conversion method. - Tustin — Bilinear (Tustin) approximation.
- Tustin with prewarping — Tustin approximation with better matching between
the original and rate-converted dynamics at the prewarp frequency. Enter the
frequency in the Prewarping frequency field. - First-order hold — Linear interpolation of inputs.
- Matched (SISO only) — Zero-pole matching equivalents.
For more detailed information about these rate-conversion methods, see “Continuous-
Discrete Conversion Methods” (Control System Toolbox).
Blocks with Fixed Rate Conversion Methods
For the following blocks, you cannot set the rate-conversion method in the Tuned Block
Editor.
View and Change Block Parameterization in Control System Tuner