Complete elecric power steering system real-time model in the loop simulator

Abstract

The paper presents a complete mechanical and electrical chain of an electric power steering (EPS) system analyzed on a real-time model in the loop (RTMiL) test platform based on usage of field programmable gate arrays (FPGAs). Based on an analytical model, the mechanical, electrical and control assemblies of the entire system were programmed into two FPGAs using National Instruments LabVIEW FPGA program. One FPGA was handling the control unit of the electrical machine and of the steering mechanism, while the second one was handling the modelling of the permanent magnet synchronous machine (PMSM) engaged in the study and the model of the mechanical chain. The two FPGAs were connected in order to mimic a real test-bench. On analog lines, the currents from the PMSM model were sent to the field oriented control (FOC) handling FPGA, on 8 bit digital lines the rotor position was delivered to the same FPGA. The control handling FPGA delivers to the PMSM and steering mechanics handling FPGA PWM signals using 3 digital lines. Hence, the two FPGAs practically have no knowledge one over the other that these are running models instead of a real electronic control unit (ECU) or the real hardware steering chain.