The unexploring problem of digital control systems analyzes in this article — the impact on their behavior of the limited bit resolution of the hardware and, accordingly, the discrete transfer functions coefficients. The research conducted by the zeros/poles and transient characteristics methods using the mathematical application MATLAB with the package Control System Toolbox and confirmed the relevance of this problem.
Digital control systems
Modern digital control systems make it possible to implement quite complex control strategy, the complexity of which is limited by the hardware capabilities, the available software and the implemented control algorithm. An important component of such an algorithm is the numerical method, which allows to discretize the control rule on the basis of a continuous prototype. Such application example is the classic PID controller, which has become the basis for the development of digital control systems.
The existence of the problem of impact of the finite precision of hardware in digital control systems which significantly influences on their practical realization was shown. The influence of data finite precision of digital control systems on their behavior using popular discretization methods (the Tustin method and the method of the correspondence of zeros and poles) and forms of discrete transfer functions and different representation of discrete transfer functions has been investigated by the computer model.