FPGA Implementation of Adaptive PID Control for Quadcopter Position Tracking

Abstract

AbstractPID control is widely used for designing controllers in production plants and automotive and robotic applications. Although it suits linear systems, with minor modifications, it can also be applied to nonlinear plants. As a simple control approach, it can be easily realized conceptually, but there is a large cost involved in the production of the working controller. A digital PID controller based on a fixed point representation of the operands can be considered for approximate realization. The field programmable gate array (FPGA), with its concurrent architecture, is an ideal way of producing programmable, cost‐, power‐, and speed‐optimized controllers with a compromised controller area compared to application‐specific approaches. In this research, the PID controller for quadcopters is initially tested for performance using MATLAB/Simulink based on continuous/analog domain operations. Then, FPGA‐based architecture mapping is performed using HDL Coder, with fixed‐point‐based operands produced using the fixed‐point conversion toolbox. With satisfactory performance obtained with system generator‐based cosimulation of the controller, Vivado IDE is used to implement the controller on a Zynq Ultrascale+ based FPGA device. The realized cost‐efficient controller is analysed for logical resources, computation power and controller frequency and inferred to be optimal with reference to all these indices. By adapting the thrust, which is the control input for the translational motion of the quadcopter, robustness against coupled motion is ensured, with higher simultaneous tracking speeds.