Applied Mechanics and Materials Vols. 278-280

Abstract: The consensus problems of two situations for singular multi-agent systems with fixed topology are discussed: directed graph without spanning tree and the disconnected undirected graph. A sufficient and necessary condition is obtained by applying the stability theory and the system is reachable asymptotically. But for normal systems, this can’t occur in upper two situations. Finally a simulation example is provided to verify the effectiveness of our theoretical result.

Abstract: Wind power and solar energy power are clean, abundant and renewable. Wind power and photovoltaic power are important alternative energy in the world, which will contribute to adjusting energy structures and protecting environments. The genetic algorithm has the characteristics of automatic optimization and approaches the simulate stuff illimitably. Also, there has no use for accurate model on questions, which is very suitable in the non-linear system. The wind/photovoltaic hybrid systems consist with wind power generation units, photovoltaic matrix, storage battery, diesel engine and data collection and control. This paper optimized the wind/photovoltaic hybrid system using genetic algorithm. The result showed the efficiency of this algorithm in the design of this kind of non-linear system. On the other hand, this hybrid system is strongly non-linear when is running. Finally, abundant operating expenses and maintains expenses will be saved by using genetic algorithm in its dynamic management according to the change of load, wind power and irradiation.

Abstract: To solve the problem of knowledge expression and reasoning model in expert system, factor neural network theory(FNN) is used in multi-expert system for oil-gas reservior protection.By introducing factor and factor space theory,knowledge expression model based on factor state space is presented.Fuzzy reasoning theory is utilized in the factor neural network to verify the effectiveness of the method and solve the reasoning problem of the expert system.The application of the expert system shows that factor neural network theory is valid in knowledge expression and reasoning model.Our proposed method based on FNN can effectively improve the accuracy of inference.

Abstract: In order to solve tower cranes interference and collision problems in the construction site, the reason of group tower cranes collision in construction site is analyzed in detail and four types of typical tower cranes collision case are summed up. The different kinds of collisions among crane rope, cargo boom and balance arm are concluded and each of the collision is analyzed detailedly. At the same time, anti-collision methods are achieved in order to prevent the collision. The best anti-collision algorithm, confirmed well in practical construction site, is chosen for the different collision case

Abstract: For investigating the feasibility of control strategy used in parallel hybrid electric vehicle, a D2P real-time simulation is introduced. A new multi-mode rule-based control strategy is proposed. The strategy is based on splitting the torque from the motor and engine so that these power sources can be operated at high efficiency. A real-time simulation platform is built based on D2P system. Real driver inputs and controller are applied while controlled objects are simulated using the model of parallel hybrid electric system computed in D2P module. Strategy is validated by D2P real-time simulation, which results show that the presented strategy is feasible and effective.

Abstract: The paper designs a high power DC motor closed-loop control system, mainly including design of H bridge drive circuit, speed detection circuit and signal conditioning circuit. In order to improve the performance of motor running, one proposes a fuzzy adaptive PID control algorithm. Firstly, one determines the degree of membership of the input values to defined fuzzy sets, then constructs the fuzzy rule table according to experience and experiments, finally, makes defuzzification for every parameter of PID controller, that is, Kp, Ki, Kd. Experiments show that both hardware implementation and software control algorithms are reliable, the running performance of the system is robust before or after adding load.

Abstract: PIO (Pilot Induced Oscillation) is the key factor to damage the flight safety and decrease the quality of manned aircraft. Most of modern PIO records associating with rate limiting or position limiting from actuation systems are defined Category II PIO. The existing compensators, e.g. the Feedback-with-Bypass (FWB) filter, can reduced the oscillation potentiality of the pilot-in-the-loop aircraft system due to rate limiting of control surface, however a negative effect evidently arose which slow the response speed of whole system. This paper uses a Real-Time PIO detector based on Short-time Fourier Transform algorithm as a trigger to determine the switch-off time of the compensator working on the whole system so as to suppress the negative effect on responses of system by FWB. Simulation results show us the positive conclusion that this kind combined FWB filter with Real-Time PIO detector is effectively preventing the Category II PIO without performance decreasing.

Abstract: A new scheme of small integrated navigation system based on micro inertial measurement unit (MIMU), global position system (GPS) is presented. The characteristic of these sensors and the structure of system are introduced respectively. The TI high performance floating point DSP TMS320C6713B is used as core processor, which is designed to realize both the data collecting and the navigation calculating. According to the error models of inertial navigation system, an integrated navigation algorithm used Kalman filter is proposed to fuse the information from all of the sensors. The simulation test results show the feasibility of the system design.

Abstract: This paper present the design and implementation of a dual-redundant flight control system for a miniature autonomous helicopter, named SRD-Heli. The systematic design procedure includes hardware integration, flight control law, exchange scheme, as well as experimental evaluation. A dual-redundant control architecture is adopted to construct the flight control system for the helicopter. The control architecture is composed by (1) an active flight control law designed for the active computer, which works in normal condition, (2) a standby flight control law to effectively control the helicopter by standby computer in fault condition. The result of actual flight tests shows that the flight control system is capable of achieving the desired performance.

Abstract: In this paper, a torque management strategy for parallel hybrid electric vehicle(PHEV) is developed. The proposed strategy is responsible for vehicle's torque distribution during driving，between the Internal Combustion Engine(ICE) and the electric motor(EM) by Fuzzy Logic Control(FLC). This has been investigated through two main aspects. The first is the optimum torque split between the ICE and the EM. The second is sustaining the State of Charge(SOC) of the battery.These goals have been accomplished by developing two fuzzy logic(FL) controllers. The FL controllers are designed based on the state of charge of the battery, the ICE speed, the vehicle's requested torque and the ICE target torque. The strategy is validated by ADVISOR2002 simulation model based on the software Matlab/Simulink. The performance of the vehicle have been analyzed throughout a combined driving cycle that represents the normal and the worst operating conditions.Compared to the electric assistant control strategy(EACS), The simulation results show that the proposed torque management strategy is effective to control the engine's operating points within the highest efficiency as well as sustain the SOC of the battery. Thereby, improving the efficiency of the ICE and the EM, enhancing the battery’s life, reducing fuel consumption and decreasing emission.