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Abstract:A method is proposed to achieve lateral stability of an autonomous bicycle with only the rotation of the front wheel. This can be achieved with a classic controller. However, if the energy consumption of the bicycle also has to be minimized, this solution is not valid. To solve this problem, an adaptive controller has been designed, which modifies its gains according to the bicycle's forward velocity, adapting its response with minimum energy consumption and satisfying the design specifications. The study demonstrates the efficiency of the proposed control, achieving an energy saving of 73.8% in trajectory tracking with respect to a conventional proportional-integral (PI) controller. These results show the importance of designing energy-efficient controllers, not only for autonomous vehicles but also for any automatic system where the energy consumption can be minimized.

High-concentrator photovoltaic (HCPV) power plants are inherently different from conventional photovoltaic (PV) power sources due to the use of concentrator modules and two-axis solar trackers. HCPV technology is a relatively new energy source; therefore, there is limited experience in its application in power plants. Bearing this in mind, this chapter aims to provide information about the special features and performance of HCPV power plants under real operating conditions. The analysis of current concentrator modules and solar trackers is addressed to achieve a better understanding of the main characteristics of this kind of systems. In addition, different methods for estimating the energy yield of an HCPV system or power plant are discussed. This is a crucial task to analyse the potential of such emerging technology. Finally, several HCPV power plants and relevant data concerning their energy yield and performance ratio (PR) are described and commented.

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This paper presents a new assembling for 2 degrees of freedom (DOF) parallel robots for executing rapid pick-and-place operations with low energy consumption, main objectives of pick-and-place operations. A conventional design of 2-DOF parallel robots is based on five-bar mechanisms. Collisions between links are highly possible, restricting the end-effector workspace and/or increasing the trajectory time to avoid collisions. In this work, an alternative assembling for preventing collision is presented. This novel assembling allows exploring the difference between the four five-bar mechanism congurations for the same position of the end-effector. Some of these congurations yield to lower time and/or lower energy consumption for the same motorization. Firstly, a dynamic model of the robot has been developed using Matlab and Simulink and validated by comparison with the results obtained by ADAMS software. A robust cascade PD regulator for controlling joint coordinates has been tuned providing a high accurate end-effector positioning. Finally, simulation results of 4 congurations are presented for executing controlled manoeuvres. The obtained results demonstrate that the conventional conguration is the worst one in terms of trajectory time or energy consumption and, conversely, the best one corresponds to an uncommonly used conguration. A workspace map where all congurations provide faster manoeuvres has been obtained in terms of Jacobian matrix and mechanism elbows distance. The results presented here allow designing a rapid manipulator for pick-and-place operations.