LABTM Control System based on FPGA

This paper presents the digital PI control method for design and simulation of a high precision limited angle brushless torque motor control system in Field Programmable Gate Array device (FPGA). The direct drive structures which are widely applied in many servo control fields. Matlab Xilinx System Generator (R) toolbox based on Fixed-Point Arithmetic is used to design the digital PI controller using DSP architecture, plot the responses of the control system and generate the VHDL source code. The control system model consists of a digital PI, a real LABTM, and a real absolute Inductosyn, encoder to rpm and position blocks. Through loading generated codes in process of the simulation that built by the digital discrete model, it is verified that the rising time of current loop is only 1.2ms, and rate loop is 8ms, overshoot is rarely 4.2%. Finally, the comprehensive positioning accuracy of system can reach up to +/- 5 arc sec, and the rate jitter achieves 5% with the +/- 4 arc sec accuracy absolute Inductosyn.