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The laser beam pointing control system is a system that achieves stable pointing of the laser beam to the target by controlling the laser beam deflection actuator. When the laser beam pointing control system is applied in harsh environments, the adverse effects of the environment on the system should be considered and the pointing error of the laser beam should be eliminated. The laser beam pointing control system adopts a control strategy based on proportional-integral-derivative (PID) controller and sliding mode controller to improve its dynamic and static performance. Finally, the advantages of PID controller and sliding mode controller in different states are combined to propose a composite control strategy. Through experimental comparative analysis, the composite control strategy has better control performance than a single control strategy and can meet the laser beam pointing requirements in different operating conditions. [ABSTRACT FROM AUTHOR]

In this paper, a composite control strategy for improved off-grid configuration based on photovoltaic (PV array), a wind turbine (WT), and a diesel engine (DE) generator to achieve high performance while supplying nonlinear loads is investigated. To operate the WT efficiently under variable speed conditions and to obtain accurate and fast convergence to the maximum global operating point without a speed sensor, an iterative interpolation method is integrated with the perturbation and observation (P&O) technique. To ensure the balance of power in the system and to achieve the maximum power from the PV array without using any maximum power point tracking (MPPT) method, and ensuring stable operation during the disturbance, a double-loop control strategy for a two-switches buck-boost converter is developed. Furthermore, to protect the synchronous generator of the diesel generator (DG) from the 5th and 7th order-harmonics created by the connected nonlinear loads and to solve the issue of the filter resonance, the interfacing three-phase inverter is controlled using an improved synchronous-reference frame algorithm (SRF) with virtual impedance active damping. The presented work demonstrates effective and efficient control along with improved performance and cost-effective option as compared to the similar works reported in the literature. The performance of the presented off-grid configuration and its developed composite control strategy are tested using MATLAB/Simulink and validated through small-scale hardware prototyping.

In this paper, a composite control strategy for improved off-grid configuration based on photovoltaic (PV array), a wind turbine (WT), and a diesel engine (DE) generator to achieve high performance while supplying nonlinear loads is investigated. To operate the WT efficiently under variable speed conditions and to obtain accurate and fast convergence to the maximum global operating point without a speed sensor, an iterative interpolation method is integrated with the perturbation and observation (P&O) technique. To ensure the balance of power in the system and to achieve the maximum power from the PV array without using any maximum power point tracking (MPPT) method, and ensuring stable operation during the disturbance, a double-loop control strategy for a two-switches buck-boost converter is developed. Furthermore, to protect the synchronous generator of the diesel generator (DG) from the 5th and 7th order-harmonics created by the connected nonlinear loads and to solve the issue of the filter resonance, the interfacing three-phase inverter is controlled using an improved synchronous-reference frame algorithm (SRF) with virtual impedance active damping. The presented work demonstrates effective and efficient control along with improved performance and cost-effective option as compared to the similar works reported in the literature. The performance of the presented off-grid configuration and its developed composite control strategy are tested using MATLAB/Simulink and validated through small-scale hardware prototyping. [ABSTRACT FROM AUTHOR]

In this study, the identification and control scheme of the motor‐drive servo turntable are researched to achieve accurate tracking. Firstly, the input–output identification experiments are designed and realised for the global model of motor‐drive servo turntable. The order of the global controlled auto‐regressive model is determined by the Akaike information criterion, and the parameters are estimated by a particle swarm optimisation‐cuckoo search algorithm. Secondly, the switched friction model is built combining the LuGre structure and the Stribeck curve. The switching conditions and the parameters of the switched friction model are determined though the input–output and the friction experiments. A constrained multi‐objective optimisation problem is constructed for the parameter identification of the switched friction model. It is solved via a fuzzy comprehensive evaluation. Finally, the composite control strategy, in which the proportional–integral–derivative controller and model‐based friction observer are combined, is proposed in the azimuth angle system of the motor‐drive servo turntable. The trajectory tracking results in simulation and experiment illustrate the effectiveness of the proposed switched model, identification method, and composite control strategy. [ABSTRACT FROM AUTHOR]