Abstract:
This paper explains the strategies to create a hardware-based real time model of DC servomotor by utilizing the FPGA
technology that can accurately simulate the behavior of the servomotor in real-time. Such FPGA based hardware model is useful
for testing control algorithms, validating designs, and optimizing performance for various applications because of its reconfiguration
capabilities. The uniqueness of our paper lies in the application of C language for modeling a DC servomotor by discretizing the model
with both Backward Euler (BE) and Trapezoidal (TRZ) methods. The discretized models are then implemented on FPGA using Vivado
HLS and the performance is analyzed with change in step-size by comparing with the transfer function (TF) model. With 100 μsec
step-size, TRZ response is found to be matching with the TF model, however, a step-size of 0.6 μsec was required for the BE. Also
analyzed the feasibility of Hardware-in-the-Loop (HIL) technique by connecting the DC servomotor in loop with the PID controller on
FPGA, again by varying the step-size. Both the BE and TRZ models could track the reference speed within 2 msec, because of the PID
controller, however faster dynamics was observed in case of TRZ as compared to BE, especially with larger step-size. This analysis
demonstrates the impact of step-size and discretization technique on real-time modeling. By selecting suitable values, the FPGA model
can be efficiently harnessed to develop a tailored control algorithm and optimize performance for diverse applications.
