Embedded Control Using FPGA

FPGA stands for Field Programmable Gate Array. It is an integrated circuit that can be configured by the user in order to implement digital logic functions of varying complexities. FPGA can be very effectively used for control purposes in processes demanding very high loop cycle time. The implementation of a digital controller in a FPGA can be parallel,resulting in very high speeds of operation. This fact enables FPGA‘s to score over general purpose computing chips like DSP chips,which have a limited number of Multiplier ACcumulator (MAC) units that can be used for the controller design. This report looks at the serial and parallel implementation of PID controller on a FPGA as suggested by [1]. A PID controller was specifically chosen so that the issues and the trade off‘s involved in the implementation of controllers could be understood. A more efficient implementation of a PID using Distributed Arithmetic (DA) was looked at. This makes use of the Look Up Table (LUT) rich characteristics of the FPGA. The final part of the report suggests the recent trends in FPGA based control like reconfiguration,co-design implementation of controllers. Mention was made of the implementation of a fuzzy logic based controller for the truck back upper problem as suggested by [2]. Also the implementation of a Model Predictive Controller using Co-design techniques as suggested by [3] was looked into.