Hardware implementation of nonlinear PID controller with FPGA based on floating point operation for 6-DOF manipulator robot arm

This paper presents the FPGA implementation of nonlinear PID controllers for humanoid robot arms. To design the nonlinear PID controller on an FPGA chip, nonlinear functions as well as the conventional PID control algorithm have to be implemented by the hardware description language. Therefore, nonlinear functions such as trigonometric or exponential functions are designed on an FPGA chip. Simulation studies of position control of humanoid arms are conducted and results are compared. Superior performances of the nonlinear PID controllers are confirmed when disturbances are present. Experiments of humanoid robot arm control tasks are conducted to confirm our design and the simulation results.