State Space Control, LQR and Observer

State of the art regulators are of the type PID combined with filters. They can be found in various combinations, such as cascaded structures or loops with feed forward. State Space regulators are not as well known by many of the engineers. Either they are a little bit more complicated to understand, either a modeling of the system is needed to design a robust and stable feedback loop. However, there is a variety of plants, where a use of State Space regulators can be justified. Especially, if regulators of multiple in and multiple out systems need to be designed, a little bit more complicated regulator structure causes very often very robust stable systems, which never could be reached by PID regulators. This booklet helps the engineer solving a regulator problem, to get another view of control feedback and simplifies the decision, whether to choose a conventional structure or a State Space regulator. The prerequisites are a knowledge about laplace operator, transfer function and stability criteria.