Performance evaluation of different real-time motion controller topologies implemented on a FPGA

This paper presents a comprehensive comparison of several real-time motion controller topologies implemented on a field programmable gate array (FPGA). Controller topologies are selected as proportional-integral-derivative controller with command feedforward, sliding mode controller, fuzzy controller, and a hysteresis controller. Controllers and other necessary modules are developed using Verilog HDL and they are implemented on a ML505 development board with a Xilinx Virtex-5 FPGA chip. In order to take full advantage of FPGA and to provide a more accurate comparison, an (soft-core) embedded processor is not employed in the design. The developed modules, which include PWM generator, quadrature encoder decoder, velocity estimator, reference profile generator etc, are fully tailored for the application. To perform the necessary calculations for certain controller topologies, an open-core floating point unit (FPU) is also adopted to the design. The performances of the aforementioned controllers are rigorously evaluated via a hardware-in-the-loop simulation of a field-oriented induction motor system.