Optimal hardware/software partitioning of a system on chip FPGA-based sensorless AC drive current controller

The recent field programmable gate array (FPGA) system on chip devices offer a new degree of design freedom. Indeed, these digital components allow the combination of software treatment (by the on-chip processor cores) and hardware treatment (hardware architecture made by the interconnection of the FPGA logic cells). In the field of industrial control applications, this digital technology is appropriate to reach an optimum between the control performances, the controller algorithm complexity and the design flexibility. On the other hand, a co-design methodology is necessary to make an efficient partitioning of the control algorithm so as to define modules to be software-made and modules to be hardware-made.To this aim, this paper deals with a co-design methodology adapted to SoC FPGA-based controllers for embedded power applications. The case study is a sensorless current controller of a synchronous machine using an extended Kalman filter (EKF). This co-design development is based on two reference implementations: a full software implementation and a full hardware implementation that are also discussed. To find the optimal HW/SW partitioning, a non-dominated sorting genetic algorithm (NSGA-II) is used.