SOFC temperature evaluation based on an adaptive fuzzy controller

Research on A Fuzzy Adaptive PID Control Method for Four Rotor UAV Control System With the continuous improvement of national living standards, people have higher and higher requirements for the reliability of power supply. The emergence of unmanned aerial vehicle inspection technology provides a new idea to solve the contradiction between the increasing equipment scale and the increasing inspection requirements. However, at present, the stability of the traditional proportion integration differentiation (PID) control system of the four rotor unmanned aerial vehicle (UAV) is not high enough. During the inspection, there are accidents of drones hitting power equipment from time to time. In view of the above problems, this paper studies the fuzzy adaptive PID control method to support the stable flight of four rotor UAV. The principle of fuzzy control is analyzed. The fuzzy control method and PID control method are deeply integrated. A fuzzy adaptive PID control system is designed. The universe and membership function of the relevant control parameters of the system are formulated. The tuning rules of fuzzy adaptive PID control system are formulated. Finally, the improved control system is simulated. The simulation results show that the fuzzy adaptive PID control algorithm can effectively improve the stability, reliability and emergency ability of UAV. This method can effectively improve the adaptability of UAV to perform complex missions in complex environments. The research results have guiding significance for expanding the application field of UAV.

Life Cycle Assessment and Life Cycle Costing of a SOFC system for distributed power generation

This paper investigated the performance of a bioethanol-fed Solid Oxide Fuel Cell (SOFC) system integrated with a distillation column (SOFC-D). Excess heat from the SOFC system was directly utilized in the distillation column where bioethanol (5 mol%) was purified to a desired concentration before feeding to the SOFC system consisting of an air heater, an ethanol/water heater, a reformer, an SOFC preheater, an SOFC stack and an afterburner. The SOFC-D system was simulated using Aspen PlusTM for the distillation portion and MatlabTM for the SOFC portion. The effects of operating parameters; i.e., ethanol concentration, ethanol recovery, fuel utilization and operating voltage on the performance and energy involved in the SOFC-D system (e.g. distillation energy: QD and the net exothermic heat of the SOFC system: QSOFC,Net) were examined. In addition, the performance of the SOFC-D system at the energy sufficient point where QD = QSOFC,Net was considered. The integration of the distillation column with the SOFC system was found to offer superior SOFC performance. The ethanol recovery and fuel utilization significantly influenced the overall electrical efficiency and power density. Quite low performances are obtained when one operated the SOFC-D without an external heat source. The maximum overall efficiency and power density (~35% and 0.22 W cm-2) occured at an ethanol recovery of 80% and Uf of 90%.

For the trajectory tracking problem of a single-particle train dynamics model under the condition of partial loss of power in the train power unit due to actuator failure during the operation of the EMU, considering the situation where the system exists with uncertain dynamics from the model and unknown external disturbers, a control method based on fuzzy adaptive fault-tolerant control method for EMU is proposed. Under the framework of the backstepping method, the fuzzy system is used to approach the system function, and a fuzzy adaptive controller is designed. It is proved that the designed control law can enable the train system to track the given speed and displacement trajectory under partial power loss. Using the CRH3 train as the research object, the results show that the designed controller can complete the trajectory tracking control task.

Recent developments in control and integration of solid oxide fuel cells: From stack to system

Based on input-output stability theory, a multi-input multi-output indirect adaptive fuzzy tracking control method for satellite attitude systems with parametric uncertainty and external disturbance is presented. First, a nonlinear controller is designed based on the satellite precision model, and stability of the closed-loop system is analyzed; then, because of contained the parametric uncertainty and external disturbance in the model, an adaptive fuzzy controller is constructed through using fuzzy logic system to approximate the uncertain section. Last, it is proved that the proposed controller can make the satellite track to the located place, and force the tracking error to converge to a small neighborhood of the origin. Simulation results show the satisfied control accuracy and robustness to the model uncertainty.

Field test results of residential SOFC co-generation system at Tokyo Gas T. Ishikawa, S. Yamashita Product Development Dept., Tokyo Gas Lo., LTD., Tokyo, JAPAN We are developing residential SOFC co-generation system in order to commercialize it. One of our activities is to operate SOFC systems in field tests to make sure effects of installation and find technical issues. The detail is as below. A serious accident at nuclear power plants in Fukushima which was triggered by a huge earthquake on 11th March 2011 forces drastic re-formulation of Japan’s energy policy. In a series of discussions on the new energy policy, promoted use of distributed power generation is demanded more than ever as one of the main power systems, with extremely strong expectations for the fuel cell co-generation system. Tokyo Gas has been conducting research and development of solid oxide fuel cell (SOFC) which is expected to achieve the highest efficiency among all distributed power systems. In parallel with it, to verify the applicability of the SOFC for residential use and to identify technical challenges of SOFC, we have started field tests of SOFC systems of multiple manufacturers in the “Solid Oxide Fuel Cell (SOFC) demonstrative research project” with financial support from NEDO (Figure 1) [1][2]. We have installed a total of 23 units of four manufacturers in the field test of over four years (from 2007 to 2010), of which 14 units are still under operation as of April 30, 2012 (table 1). And the operating time has reached 18,600 hours at the longest, with 268,500 hours in total of 23 units. We have acquired the knowledge as shown below during the field tests conducted at general residences which we selected to reflect a variety of electrical and hot water demands (Figure 2). (1) Residential SOFC co-generation system contributes to the saving the preliminary energy consumptions and CO2 emissions by households in Japan (Figure 3, Figure 4). (2) SOFC system shows high electricity efficiency exceeding 45%LHV, and the transition of efficiency indicates that the durability of SOFC system including cell stack is estimated to be almost practical use (Figure 5). (3) SOFC system shows high reliability because of its simple system configuration. We will report the detailed results of SOFC field tests based on the latest data. Acknowledgments Finally, we would like to express our appreciation to NEDO, as this report is prepared mainly based on the results of the project supported by NEDO. Figure 2 Residential Demand (/Month) References [1] Solid Oxide Fuel Cell demonstrative research project final report (2011) http://www.nef.or.jp/sofc/share/pdf/h22y.pdf [2] Y. KAWABATA, T.SEYAMA, T.SOBUE, International Gas Union Research Conference ( 2011 ) Development and Field Test of Residential SOFC Co-generation System with All-ceramics-segmented Cells

Performance analysis of methanol-fueled solid oxide fuel cell system incorporated with palladium membrane reactor

The paper aims to expand a way of applying the fuzzy adaptive control strategy by analyzing the advantages and disadvantages of traditional PID control strategies. In view of the high requirements of the variable-pitch servo system for megawatt-level wind turbines, combined with the control characteristics of series-excited DC servo motors, a wind power variable-pitch DC servo system based on fuzzy adaptation was designed. The superiority and reliability of the fuzzy adaptive PI control method are verified by using simulation tools to carry out simulation experiments, and then the experiments are carried out by DC series servo motor and servo driver. In summary, the performance of the wind power variable pitch DC servo system is excellent.

This paper is dedicated to the trajectory tracking control of under-actuated unmanned surface vessel (USV) with state and input quantization. In terms of kinematics, a distributed guidance law is introduced to track the time-varying trajectory of USV. In terms of kinetics, a fuzzy adaptive quantization control method rooted in an event-triggered mechanism is proposed. Uncertainties within the ship model are estimated through a fuzzy logic system, and a linear analytical model is employed to elucidate the input quantization process. This approach reduces the actuator's execution frequency, alleviates the communication burden and conserves valuable communication resources. The boundedness of the internal signals and quantization errors in the closed-loop system are substantiated by presenting some theoretical lemmas. Furthermore, the stability of the proposed control strategy is proved through Lyapunov stability theory. Finally, the effectiveness and feasibility of the proposed fuzzy adaptive quantization control strategy based on event-triggered mechanism are verified by simulation experiments.

Large space truss structure is widely used in spacecrafts. The vibration of this kind of structure will cause some serious problems. For instance, it will disturb the work of the payloads which are supported on the truss, even worse, it will deactivate the spacecrafts. Therefore, it is highly in need of executing vibration control for large space truss structure. Large space intelligent truss system (LSITS) is not a normal truss structure but a complex truss system consisting of common rods and active rods, and there are at least one actuator and one sensor in each active rod. One of the key points in the vibration control for LSITS is the location assignment of actuators and sensors. The positions of actuators and sensors will directly determine the properties of the control system, such as stability, controllability, observability, etc. In this paper, placement optimization of actuators and sensors (POAS) and decentralized adaptive fuzzy control methods are presented to solve the vibration control problem. The electro-mechanical coupled equations of the active rod are established, and the optimization criterion which does not depend upon control methods is proposed. The optimal positions of actuators and sensors in LSITS are obtained by using genetic algorithm (GA). Furthermore, the decentralized adaptive fuzzy vibration controller is designed to control LSITS. The LSITS dynamic equations with considering those remaining modes are derived. The adaptive fuzzy control scheme is improved via sliding control method. One T-typed truss structure is taken as an example and a demonstration experiment is carried out. The experimental results show that the GA is reliable and valid for placement optimization of actuators and sensors, and the adaptive fuzzy controller can effectively suppress the vibration of LSITS without control spillovers and observation spillovers.

In this research, a fuzzy adaptive PD control approach is introduced for managing the coupled indoor temperature and humidity system. Initially, the mathematical framework of indoor temperature and humidity is analyzed. For the coupled system, a decoupling control strategy is introduced, which eliminates the mutual influence between temperature and humidity by incorporating decoupling components, thereby enabling the system to be equivalently controlled as two independent single-input single-output systems. Secondly, a fuzzy adaptive PD control method is employed to achieve parameter self-tuning. Finally, to assess the efficacy of the introduced control approach, the present study undertakes a simulation analysis, utilizing a medium-sized office as a case study. The outcomes of the simulation suggest that upon implementing the fuzzy adaptive PD control methodology, the modulation of indoor temperature and humidity achieves enhanced precision and swiftness, notably demonstrating greater robustness in the presence of disturbance signals.

In this paper, we propose an adaptive fuzzy output feedback control method for trajectory tracking control problem for robotic systems. Using Lyapunov method, we first develop a stable adaptive fuzzy state feedback control algorithm by assuming that the systems output and its derivatives are available for feedback control design. The algorithm combines fuzzy systems with robust adaptive controller. The fuzzy system approximates the certainty equivalent (CE)-based optimal controller while robustifying adaptive control term is used to cope with uncertainties that appeared from the effect of external disturbance, fuzzy approximation errors and other modeling errors. Then, an output feedback form of the position-velocity (state feedback) controller is proposed where unknown velocity signal is replaced by the output of model-free linear estimator. We show via asymptotic analysis that the tracking performance of the output feedback design can recover the performance achieved under the state feedback control design. Finally, the proposed method is implemented and evaluated on a 2-DOF robotic system to demonstrate the theoretical development for the real-time applications.

The satisfaction of ultimate customer can measure with four gross criteria in the supply chain, and can subdivide into ten sub-criteria. Customer satisfaction mainly performs from customer, so there is certain preference as a weight to each criterion. The weight is difficult to focus on one point, but can establish the scope generally. Moreover, the decision maker has certain preference to each criterion according to the supply chain characteristics. In this paper, an overall evaluation of customer satisfaction in the supply chain on condition of the weight scope is researched by multiple criteria decision making theories and statistics. Moreover a fuzzy customer satisfaction adaptive control method based on the customer satisfaction model is presented in the supply chain.

Distributed adaptive fuzzy control for multi-agent systems with full state constraints and unmeasured states