Component
École Nationale Supérieure d'Électrotechnique d'Électronique d'Informatique d'Hydraulique et des Télécommunications
Semester
Printemps
Objectives
Be able to…• Identify the different components and the role of the sampling period,• Construct the equivalent continuous block diagram of a discrete control system,• Calculate the parameters of a continuous controller and discretize it,• Define the block diagram in z,• Calculate the transfer functions in z and the associated time responses,• Calculate the poles and deduce the type of associated time response,• Calculate a PID controller in z and deduce its recursive equation, and vice versa.
Description
Presentation of a sampled speed control: block diagram, functions implemented in a digital controller. Influence of the sampling period: influence of the sampling period on stability, destabilizing effect of Sampling/Hold. Study of control by approximation to a continuous system: definition of the equivalent continuous system, methods for studying sampled controls, synthesis of P controller, discretization of continuous controller. Z-transform: definition and properties, discrete transfer functions, real poles - complex poles. Time-domain study of sampled control systems: static study: accuracy, dynamic study: stability, time responses.
Synthesis of sampled controllers, Experimental tuning of sampled controllers
Criteria for choosing the sampling period: Shannon criterion, real poles, complex poles, phase shift due to sampling/blocking, processing time on the computer, problem of derivation, influence of noise, number coding on microprocessor.
Pre-requisites
• Decomposition into Fourier series,
• Plotting Bode, Black, and Nyquist diagrams, calculations of continuous linear controllers, nested loops, and feedforward chains,
• Basic calculations with the Z-transform, signal transform, inverse transform, final value theorem, initial value theorem, delay…
• Calculations with complex numbers, solving first- and second-order differential equations.
