- •Introduction to control Part I
- •Text 1. Control System
- •8. Make a list of terms from Text 1 referring to control and memorize them.
- •9. Read and translate Text 2 Text 2. Basic Feedback Loop
- •10. Make a list of terms from Text 2 referring to control and memorize them.
- •11. Read and give a short summary of Text 3 Text 3. An example
- •12. Make a list of terms from Text 3 referring to control and memorize them.
- •13. Translate Text 4 in written form: Text 4. Regulators and Servomechanisms
- •16. Supply synonyms for the following words:
- •17. Analyse the grammatical structure of the following sentences and translate them:
- •Text 5. Stability and performance
- •19. Make a list of terms from Text 5 referring to control and memorize them.
- •23. Supply synonyms for the following words: Meet, to take place, because of, as regards, breakdown, to consider
- •24. Analyse the grammatical structure of the following sentences and translate them:
- •25. Translate Text 6: Text 6. The uncertainties
- •25. Make a list of terms from Text 6 referring to control and memorize them.
- •26. Read and translate Text 7. Text 7
- •27. Make a list of terms from Text 7 referring to control and memorize them.
- •28. Read and translate Text 8 without a dictionary. Text 8. Representations of Uncertainty
- •30. Give derivatives of the following words and translate them into Russian:
- •32. Supply synonyms for the following words:
- •Text 9. Servomechanism
- •Text 10. Performance: Tracking and Disturbance Rejection
- •43. Make a list of terms from Text 10 and memorize them. Rart II
- •1. Read and translate Text 11.
- •Text 11. The Philosophy of Classical Control
- •Make a list of terms from Text 11 and memorize them.
- •Read and translate Text 12. Text 12. Classical control theory: the closed-loop controller
- •Make a list of terms from Text 12 and memorize them.
- •Read and translate Text 13. Text 13. Controllability and Observability
- •Make a list of terms from Text 13 and memorize them.
- •Read and translate Text 14. Text 14. Control Specifications
- •Make a list of terms from Text 14 and memorize them.
- •Read and translate Text 15. Text 15. Model Identification and Robustness
- •System identification
- •Analysis
- •Constraints
- •Make a list of terms from Text 15 and memorize them.
- •Read and translate Text 16 Text 16. Control Objectives
- •Make a list of terms from Text 16 and memorize them
- •Give a short summary of Text 17 Text 17. Control Objectives
- •(From Ch.Schmid. Course on Dynamics of multidisplicinary and controlled Systems )
- •Make a list of terms from Text 17 and memorize them
- •Give a short summary of Text 18 (in written form) Text 18. Main control strategies
- •Pid controllers
- •Optimal control
- •Adaptive control
- •Intelligent control
- •17. Make a list of scientific terms that are used in Text 18, give their Russian equivalents and memorize them.
- •18. Give a short summary of Text 19 (in written form) Text 19. Feedback
- •Application of feedback in mechanical engineering
- •Make a list of terms from Text 19 and memorize them.
- •Give a short summary of Text 20 Text 20. Pid controller
16. Supply synonyms for the following words:
problem, demand, limit, finally, task, to make smb/smth do smth, accurate, different, usual, that is why, suggested, to operate
17. Analyse the grammatical structure of the following sentences and translate them:
Absence of stability causes signals to grow without bound.
This is what happens when a satellite spins out of control
The job of feedback control is to stabilize the system
It makes the system track the reference input.
It causes the potential for instability to be everpresent and very real.
It is of fundamental importance that control systems be designed so that stability is preserved in the face of various classes of uncertainties.
The model is assumed to be linear and time invariant.
It is necessary to give the precise description of the external signals to be tracked or rejected.
18. Read and translate Text 5:
Text 5. Stability and performance
Stability and performance are two of the fundamental issues in the design, analysis and evaluation of control systems. Stability means that, in the absence of external excitation, all signals in the system decay to zero. Stability of the closed loop system is an absolute requirement since its absence causes signals to grow without bound, eventually destroying and breaking down the plant. This is what happens when an aircraft crashes, or a satellite spins out of control or a nuclear reactor core heats up uncontrollably and melts down. In many interesting applications the open loop plant is unstable and the job of feedback control is to stabilize the system. While feedback is necessary to make the system track the reference input, its presence in control systems causes the potential for instability to be everpresent and very real. We shall make this notion more precise below in the context of servomechanisms. In engineering systems it is of fundamental importance that control systems be designed so that stability is preserved in the face of various classes of uncertainties. This property is known as robust stability.
The performance of a system usually refers to its ability to track reference signals closely and reject disturbances. A well designed control system or servomechanism should be capable of tracking all reference signals belonging to a class of signals, without excessive error, despite various types of uncertainties. In other words the worst case performance over the uncertainty set should be acceptable. This is, roughly speaking, referred to as robust performance.
In analysis and design it is customary to work with a nominal mathematical model. This is invariably assumed to be linear and time invariant, because this is the only class of systems for which there exists any reasonably general design theory. Nevertheless, such models are usually a gross oversimplification and it is therefore necessary to test the validity of any proposed design by testing its performance when the model is significantly different from the nominal.
In summary the requirements of robust stability and performance are meant to ensure that the control system functions reliably despite the presence of significant uncertainty regarding the model of the system and the precise description of the external signals to be tracked or rejected.
(from S.P.Bhattacharyya, H. Chapellat, L.H.Keel. Robust Control. The Parametric Approach)