Implementations of state-space controllers using Field Programmable Gate Arrays

Field Programmable Gate Arrays (FPGAs) are suitable choices for demanding real-time control applications including CNC machine tools, robotics, advanced automation, aviation, automotive systems. Logic-level design capabilities of FPGAs allow engineers to develop efficient yet flexible methods for motion control applications. In fact, certain properties of FPGAs (parallelism, layout management, logic optimization, etc.) can be exploited to reduce the resources used on the FPGA without sacrificing the performance. This paper focuses on this aspect and presents novel implementation methods for motion controllers using FPGAs. The presented methods are applied to a full-state space controller utilizing a Luenberger-type state observer. This controller topology, which can be easily tailored to any application, is implemented on an Altera Cyclone II FPGA chip utilizing the methods elaborated in the paper. Furthermore, the control performances of the resulting systems are investigated through a hardware in the loop simulation (HILS) of a nonlinear system (inverted pendulum) using MATLAB.