Expressing Transfer Function in Ansys Scade Suite Software — Lesson 3

For this system, the transfer function representing the pitching (pitch, θ) motion of a helicopter with 'Σ' two degrees of freedom has been selected [7]. The system's transfer function was derived using the state-space equation provided in [7]. Similarly, the controller coefficients chosen for this transfer function are specific to this system. Here, '𝐼𝑛' represents the system's input, and '𝑦' signifies the system's output. '𝑇𝑓𝑁𝑢𝑚' and '𝑇𝑓𝐷𝑒𝑛' are constants containing arrays related to the transfer functions, as provided in Table under Lesson 1. The discrete-time transfer function of the system '𝑇(𝑧)' is given in the following equation.

Here, the output 𝜃 (𝑧) refers to the pitch angle, and input 𝑉𝑚, 𝑝 (𝑧) refers to the voltage applied to the engine that provides the pitch movement.

The Ansys Scade Suite application model expressing the transfer function given above is given in the following Figure. This model has been recreated based on the “TransferFcnND <<Ns, Ds>>” operator in the “liblinear” library.

Figure 4 Transfer Function