An evaporatively-cooled facade system, composed of a Photovoltaic thermal (PVT), evaporative cooler, and evaporatively-cooled facade, was previously developed. In this study, a control algorithm for the system paramet...
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An evaporatively-cooled facade system, composed of a Photovoltaic thermal (PVT), evaporative cooler, and evaporatively-cooled facade, was previously developed. In this study, a control algorithm for the system parameters is implemented and applied on spaces with evaporatively-cooled facade to generate the least possible facade temperature, and con sequently maximum possible energy savings. The optimization of the system parameters is expected to overcome the limitations of using evaporative coolers in humid countries. The application of the control algorithm managed to increase the reductions in the facade heat gain from 33.5% to 38.3%. The system, integrated with the control algorithm, is then applied throughout the year on spaces located in Doha (Qatar) and Riyadh (Saudi Arabia), mimicking cities with harshly hot humid and dry weather conditions, respectively. The daily and monthly performances are further investigated in four different space orientations (i.e., north, east, south, and west). It was found that the application of the system can halve the highly glazed facade heat gain during the summer, in all orientations, and may have adverse, yet desirable effect during the winter. The integration of the control algorithm managed to reduce differences in system performance between dry and humid locations, thus generating total annual savings of up to 21.8% in any typical city of the Arabian Gulf.
One of the principal purposes of using energy storage systems (ESS) are peak shaving and load smoothing. In the present study, a novel control algorithm has been developed in order to the optimal use of ESS for peak l...
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One of the principal purposes of using energy storage systems (ESS) are peak shaving and load smoothing. In the present study, a novel control algorithm has been developed in order to the optimal use of ESS for peak load shaving. First, by comparing the complex control algorithm of the present study with the control algorithm developed by other researchers (simple control algorithm), the superiority and advantage of the present work become clear. To do this, five different load demand profiles have been considered and the mentioned algorithms have been applied to them. The results show that the implementation of the present study novel algorithm on the load demand profiles number one to five reduces the maximum of the required grid power to 6.477%, 11.81%, 12.60%, 10.25%, and 3.000% of their initial value, respectively. Their variance also reduces their initial value to 14.47%, 14.20%, 28.48%, 39.87%, and 54.96%, respectively. On the other hand, the implementation of the simple control algorithm has reduced the maximum of the required grid power to 0.8542% of its initial value only in the fifth profile. But the variance in the first to fifth profiles is reduced by 9.630%, 5.831%, 14.12%, 21.89%, and 52.00% of their initial value, respectively. In the following, by applying the novel control algorithm on the first sample load demand profile and change of various parameters such as ESS capacity, lower and upper limitation of the grid power, etc. the results are extracted and reported in detail. (c) 2022 Published by Elsevier Ltd.
Recently, as the satellite data service market has grown significantly, satellite demand has been rapidly increasing. Demand for geostationary satellites with weather observation, communication broadcasting, and GPS m...
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Recently, as the satellite data service market has grown significantly, satellite demand has been rapidly increasing. Demand for geostationary satellites with weather observation, communication broadcasting, and GPS missions is also increasing. Completing the charging process of the Li-ion battery during the sun period is one of the main tasks of the electrical power system in geostationary satellites. In the case of the electrical power system of low Earth orbit satellites, the Li-ion battery is connected to the DC/DC converter output, and the charging process is completed through CV control. However, in the case of the regulated bus of the DET type, which is mainly used in the electrical power system of geostationary satellites, a Li-ion battery is connected to the input of the DC/DC converter. Therefore, a method other than the CV control of the DC/DC converter is required. This paper proposes a control algorithm for tapering charging of the Li-ion battery in the regulated bus of the DET type for Li-ion battery charge completion operation required by space-level design standards. In addition, the proposed control algorithm is verified through an experiment on a geostationary satellite's ground electrical test platform. The experiment verified that it has a power conversion efficiency of 99.5% from the solar array to the battery. It has 21 tapering steps at the equinox and 17 tapering steps at the solstice.
This paper presents grasping strategy of robot fingers based on tactile sensing information acquired by optical three-axis tactile sensor. We developed a novel optical three-axis tactile sensor system based on an opti...
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This paper presents grasping strategy of robot fingers based on tactile sensing information acquired by optical three-axis tactile sensor. We developed a novel optical three-axis tactile sensor system based on an optical waveguide transduction method capable of acquiring normal and shearing forces. The sensors are mounted on fingertips of two robotic fingers. To enhance the ability of recognizing and manipulating objects, we designed the robot control system architecture comprised of connection module, thinking routines, and a hand/finger control modules. We proposed tactile sensing-based control algorithm in the robot finger control system to control fingertips movements by defining optimum grasp pressure and perform re-push movement when slippage was detected. Verification experiments were conducted whose results revealed that the finger's system managed to recognize the stiffness of unknown objects and complied with sudden changes of the object's weight during object manipulation tasks.
This study aimed to develop a hybrid control algorithm for semiactive control devices to effectively control the drift caused by seismic loads in the superstructure of an isolated multispan bridge. First, bridge behav...
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This study aimed to develop a hybrid control algorithm for semiactive control devices to effectively control the drift caused by seismic loads in the superstructure of an isolated multispan bridge. First, bridge behavior was simulated using the Newmark method to select a semiactive control device that would be appropriate for the bridge structure. An optimal control force was selected to control the displacement and relative displacement of each superstructure element. Next, an equation of motion that employed a stochastic linearization capable of representing the nonlinearity beyond the structural linear limits was used. Further, a Bouc?Wen model was designed to simulate the nonlinearity of the structure model and the control device to configure the control logic. A hybrid control algorithm was developed to overcome the disadvantages of the clipped-optimal and Lyapunov control algorithms, which show excellent control effectiveness but experience problems during nonlinear control along with extreme manual control problems owing to their use of the Heaviside step function. The two control algorithms were used individually to make judgments, and the results of each were used to produce a three-stage signal (min., max., median). The performance of the proposed control method with the developed algorithm was verified through experimental tests. The developed hybrid control algorithm improved the performance of the two individual control algorithms and effectively controlled the behavior of multispan bridges.
To intercept the great maneuvering target, combining with the sliding mode and the extended disturbance observer, a new control algorithm for integrated guidance and control (IGC) system is proposed in this paper. Fir...
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To intercept the great maneuvering target, combining with the sliding mode and the extended disturbance observer, a new control algorithm for integrated guidance and control (IGC) system is proposed in this paper. Firstly, the paper formulates the Missile-Target problem. Then the paper establishes an uncertain IGC dynamic model where the nonlinearities, the perturbations and the maneuvering of the target are regarded as disturbance. Secondly, a second-order disturbance observer is designed to estimate the disturbance and their derivatives.. After this, combining with the second-order disturbance observer, a modified sliding surface and the corresponding reaching law are designed to obtain the rudder deflection command directly. Thus, the real sense of IGC system is achieved. Next, the paper uses the Lyapunov stability theory to prove the stability of the system. Finally, the paper provides different simulation cases, which have different maneuver modes of the target, to demonstrate the superiority of the proposed method in reducing the response time, increasing the rudder response, and having a high interception probability.
New approaches and technology of development adaptive to voltage oscillation leakage current protection systems used in isolated neutral system are proposed. The control algorithm of protection device developed using ...
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New approaches and technology of development adaptive to voltage oscillation leakage current protection systems used in isolated neutral system are proposed. The control algorithm of protection device developed using fuzzy logic, which allows adapting of protection devices’ thresholds to network parameters changing. Linear integrated and square-law integrated criteria of protection device's threshold adaption for network parameters changing are developed and proved. The model and structure of automatic thresholds adaption system are developed, based on the fuzzy controller.
This paper focuses on the robustness analysis of a simple (second-order) control algorithm for data transfer in high-speed networks. The model under consideration (derived using a fluid approximation technique) can be...
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This paper focuses on the robustness analysis of a simple (second-order) control algorithm for data transfer in high-speed networks. The model under consideration (derived using a fluid approximation technique) can be found in Izmailov (1996). The novelty of the approach lies in characterizing the stability of the scheme in the delay-parameter space (where the delays correspond to the control-time interval, and to the round-trip time, respectively), and its interest is due to the computation of some delay-insensitive measures for the algorithm which give upper and lower bounds for the uncertainty in the knowledge of the round-trip times.
Cars are becoming more and more common in today’s society, and people are increasingly relying on cars when they travel daily. In developed countries, more than 50% of goods are transported by car, and passenger tran...
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Cars are becoming more and more common in today’s society, and people are increasingly relying on cars when they travel daily. In developed countries, more than 50% of goods are transported by car, and passenger transportation is as high as 60%. Nowadays, it is necessary to refer to the per capita car holdings to evaluate whether a country’s industry is developed. Therefore, the number of cars is increasing day by day. At the same time, environmental pollution and traffic accidents caused by automobiles are becoming more and more serious. In the automotive engineering world, it is extremely urgent to solve a series of negative problems brought about by automobiles. Since the mid to late 1980s, many countries have begun to do some research on smart car systems. The smart car is a comprehensive system that integrates multiple levels of assisted driving and environmental awareness. With the progress of research, nowadays smart cars can complete the functions of roadblock recognition and security. This article is based on the research of intelligent cars, and conducts a more in-depth discussion on the control algorithms of smart cars, hoping to help the development of smart cars.
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