Dechun Zheng and Jinliang Zhang. A Design Method for SOC-Based Servo Control System. Dynamic Systems and Applications 29 (2020) No. 6, 2264 – 2274

https://doi.org/10.46719/dsa20202967

ABSTRACT. The control performance of the servo motor driver mainly depends on the implementation and performance of its current loop vector controller. During the implementation of the servo control system based on FPGA, the challenge is to shorten the calculation time of the current loop and occupy as little as possible the multiplier resources in FPGA. In this work, we introduce a design and implementation method for a SoC-based servo controller, to enhance the performance of vector controller and reduce the hardware cost. More precisely, we propose a type of servo control architecture based on Nios soft-core processor and present a high-speed Field Programmable Gate Array (FPGA) implementation of the vector control algorithms. For FPGA implementation of vector control, we design a vector control central parallel computing unit, which consists of four independent multipliers and two adders. Next, we normalize the vector control algorithm for current loop into seven computation steps, each of which can be addressed by central computing units. Finally, we design a system sequence state machine conducting time-division multiplexing (TDM) on the central computing units, to complete the entire vector control algorithm. By implementing central parallel computation and TDM, we do not only manage to effectively improve the computation speed of the entire current loop vector control, but also significantly reduce the resource requirements for FPGA. Our experimental results show that the proposed method can be successfully applied to the implementation of a complete servo control system on a low-end Altera Cyclone FPGA, and the execution of our current loop vector control algorithm can complete within 1.6 microsecond.

Keywords:vector control, servo control, FPGA, SoC，TDM.