A synthesis procedure for sampled-data systems
This paper proposes a direct synthesis procedure for the design of sampled-data systems using the z-transformation method. This procedure can be summarized as follows: 1. By methods set forth in the literature the pole-zero configuration of a continuous system is found such that the specifications are satisfied. 2. The z-transformation of the output of the sampled-data system is found such that the response of the sampled-data system coincides with the response of the continuous system at the sampling instants. 3. The closed-loop pole-zero configuration in the z-plane is determined from the transform of the output. 4. The open-loop pole-zero configuration is found from the closed-loop configuration. 5. From the open-loop pole-zero configuration the open-loop transfer function can be found in the s-plane from which the compensation network is synthesized. This paper demonstrates that in certain cases restrictions exist concerning the location of the poles and zeros of step 1 of the above procedure. The paper concludes by summarizing the scope of usefulness and limitations of the procedure.