This paper proposes a methodology for optimizing a class of robotic solar tracking systems with two degrees of freedom using a heuristic approach. The proposal allows a balance to be found between the energy consumption and tracking accuracy in the tracking system. The main purpose is the behavior modification of the system through the combination of two manipulation strategies, one associated with the energy savings and the other with the tracking error. The heuristic approach was implemented in a solar tracking system with the end effector connected to a solar measurement device. Four energy saving strategies and three tracking strategies were developed, simulated and implemented in the system. The simulation results show that the resulting strategy combination (tracking error and energy saving approach) led to 31.55% energy saved compared to the reference values, with a tracking error of 0.06∘. Moreover, the experimental assessment of the same combination led to 26.98% energy being saved, with an azimuthal tracking error of 0.062∘ and elevation tracking error of 0.071∘. The preceding values support the aim of the presented proposal to significantly reduce the energy consumption while concurrently achieving a competitive tracking error.

Solar Tracking Systems are useful to increase the generation efficiency of photovoltaic technology, mainly for concentration technology, where dual-axis is required on account of the high accurate alignment to the Sun. Even when there exists a strong relation between tracking error and energy efficiency, multiple technological and research developments have sought to solve these problems independently. The present research proposes a novel concurrent design methodology for optimizing the overall performance of two-axis trackers, allowing to keep a balance between the tracking error and the energy consumption from the design stage, from an optimization approach. The concurrent approach was implemented to design a Solar Tracker as a solar monitoring system, was compared with four commercial systems, obtaining a similar pointing accuracy with a mixed tracking error of ${0.0942}^{°}$. The system has the best energy balance, consuming only $0.9641\%$ of the energy generated for the tracking action, below commercial models. Finally, a CO${}_2$ impact analysis was carried out, where the proposed tracker obtained the lowest value, with $25.7018$ g. The results support the developed concurrent strategy for the optimization of the overall performance of dual-axis systems, allowing us to find a harmonic balance between the energy consumption and the required tracking accuracy.

A nonlinear controller for the stabilisation of the Furuta pendulum is presented. The control strategy is based on a partial feedback linearisation. In a first stage only the actuated coordinate of the Furuta pendulum is linearised. Then, the stabilising feedback controller is obtained by applying the Lyapunov direct method. That is, using this method we prove local asymptotic stability and demonstrate that the closed-loop system has a large region of attraction. The stability analysis is carried out by means of LaSalle's invariance principle. To assess the controller effectiveness, the results of the corresponding numerical simulations are presented.