Task: Design Controller
Relationships
Main Description

The task Design Controller consists of splitting the different calculations that are necessary for performing the control task into

1.      N different execution units (i.e. processes) eu1, …, euN with

2.      different repetition patterns (i.e. periods) p1,…, pN.

This activity is called control design through time structuring. For the trade-off analysis between control quality and timing quality, the time structures of all considered control applications represent the search space that shall be explored.

In the following the simplest case of control design through time structuring, assuming linear systems is explained.

Example Linear Control

We assume that N control applications shall be developed and integrated onto the same ECU.

For the simplest case of time structuring we assume that all necessary calculations, i.e. the internal controller state r(k) and the controller output u(k), for each of the N control applications are performed in single processes that are repeated with fixed sampling rates.

In the subsequent steps of the methodology, an exploration loop is implemented that explores the trade-off formulated above:

What are the optimal sampling rates for the N given control applications such that their individual control quality is sufficient AND such that the overall timing behaviour of the system is satisfactory?