Design and implementation of DSP and FPGA-based robust visual servoing control of an inverted pendulum

This paper presents the design and implementation of robust real-time visual servoing control with an FPGA-based image co-processor for a rotary inverted pendulum. The position of the pendulum is measured with a machine vision system whose image processing algorithms are pipelined and implemented on a field programmable gate array (FPGA) device to meet real-time constraints. To enforce robustness to model uncertainty, and to attenuate disturbance and sensor noise, the design of the stabilizing controller is formulated as a problem of the mixed H₂/H_∞ control, which is then solved using the linear matrix inequality (LMI) approach. The designed control law is implemented on a digital signal processor (DSP). The effectiveness of the controller and the FPGA-based image co-processor is verified through experimental studies. The experimental results show that the designed system is able to robustly control an inverted pendulum in real-time.