Signal processing in iterative improvement of inverted pendulum crane mode control system performance

This paper discusses signal processing aspects concerning the iterative experiment-based improvement of the performance of crane mode control systems of inverted pendulum systems. The control system performance specifications are imposed in terms of a reference model, and the objective is to force the output error defined as the difference between the cart position as controlled output and the model reference output to tend to zero. An optimization problem with an objective function defined as the sum of squared output errors is defined. Iterative Feedback Tuning (IFT) algorithms are employed to solve the optimization problem where the variables are the controller tuning parameters. Four-parameter discrete-time linear controllers are proposed and tuned by IFT algorithms. The real-time experimental results highlight the performance improvement ensured by the position control system with the new IFT-based linear controller with respect to the initial proportional-integral one.