Applied Mechanics and Materials Vols. 284-287

Abstract: This paper presents an intelligent control scheme that uses different cerebellar model articulation controllers (CMACs) in aircraft automatic landing control. The proposed intelligent control system can act as an experienced pilot and guide the aircraft landed safely in wind shear condition. Lyapunov theory is applied to obtain adaptive learning rule and stability analysis is also provided. Furthermore, the proposed controllers are implemented in a DSP. The simulations by MatLab are demonstrated.

Abstract: In this paper, we describe the synthesis of robust and non-fragile Kalman filter design for a class of uncertain linear system with polytopic uncertainties and filter gain variations. The sufficient condition of filter existence, the design method of robust non-fragile filter, and the measure of non-fragility in filter are presented via LMIs(Linear Matrix Inequality) technique. And the obtained sufficient condition can be represented as PLMIs(Parameterized Linear Matrix Inequalities) that is, coefficients of LMIs are functions of a parameter confined to a compact set. Since PLMIs generate infinite LMIs, we use relaxation technique, find a finite solution for robust non-fragile filter, and show that the resulting filter guarantees the asymptotic stability with parameter uncertainties and filter fragility. Finally, a numerical example is shown to validate the proposed design method.

Abstract: Control technology is necessary for air handling units to maintain suitable conditions in buildings that trend to have low energy consumption and operation cost. This study proposes an adaptive scheme of determining temperature set point that is feasible for many existing control methods, such as return- and supply-air temperature feedback control, of air handling units. The implementation procedure and concrete contribution are described below. A wireless sensor network with Zigbee communication protocol is first established. The environmental dry-bulb temperature and humidity are sensed using end nodes while routers and coordinators pass on and collect data. A heat index, called apparent temperature, is then introduced to indicate the human sensation of thermal comfort. By simultaneously considering the environmental and targeted apparent temperature, an adaptive temperature set point of each air handling unit is derived using fuzzy logics. Next, the proposed scheme is employed to an air conditioning system, in which the PID control method is used in determining the quantity of chilled water entering the cooling coil. Experimental results demonstrate the achievement of stable variation of apparent temperature ranging in a thermal comfort region for occupants. Furthermore, the power consumption of chillers is reduced since the quantity of chilled water used in heat transfer is decreased.

Abstract: In this paper, a variable structure controller based on dynamic game theory is proposed to reduce the effects of parameter variations, and external disturbances caused by uncertain systems. The variable structure controller (VSC) is a popular method for tracking control, since it can offer robustness to parameter variations, and external disturbances. However, the chattering problem occurs. The chattering may cause the degraded system performance and poor tracking control. Thus, the dynamic game theory is applied in VSC, to quickly, and precisely enforce the system states to the sliding surface, thus reducing the chattering. The stability and the convergence of the overall system are confirmed by the Hamiltonian function. The control algorithm has been realized for the actual power conditioning system (PCS) controlled by a TMS320F2812 DSP. With this proposed controller, an example that the controlled PCS under nonlinear loads yields the better robustness in performance. Experimental results validate the theoretical analysis.

Abstract: In modern combat aircrafts, avionics integrated systems play an increasingly important role. Bus test and analysis system is used as a testing platform for the testing, debugging, maintenance and monitoring of airborne electronic equipment, which could rapidly detect and identify the working status of the bus. This paper discusses the general avionics data bus test system design and implementation, which focuses on the test system design, system management, software development, and the bus information flow management of the whole system. The universal test and analysis system is based on the bus test analysis platform of ICD database that can effectively test ARINC429 bus and 1553B bus. Through integrating the platform into the simulation system, it can complete the closed-loop test of the integrated avionics simulation test system, analyze the state changes of various information flows during the process of bus communication, test and verify the active status and logical sequence of avionic fire control test systems, which has achieved very good results in the practical engineering applications.

Abstract: An Equipment Failure Analysis Expert System (EFAES) is to be developed to help the engineers diagnose the causes of the failure mechanism and provide a reliable remedy. This system is based on an innovative reasoning approach: integrating the rule-based reasoning (RBR) and the case-based reasoning (CBR) methods The architecture developed in the system consists of six major elements-“Factor and Attribute Editor”, Knowledge Actuation Interface”, “Knowledge Base”, “User Interface”, “Inference Engine” and “Explanation Facility”. Here, the RBR system consists of 46 failure mechanisms and their rules. The CBR system consists of 586 failure cases which are coded and composed from 23 factors and their 265 attributes. Also, this system provides a variety of inference methods which allows retrieving the best answers to users. For the RBR system, performance is directly check the inferred order of the document ranking list. For the CBR system, the effectiveness of each inference method is evaluated by using “Recall”, “Precision”, and “F-Measure” approaches. From the test results, many recommendations are proposed.

Abstract: Elevators are the essential transportation tools in high buildings so that Elevator Group Control System (EGCS) is developed to dynamically layout the schedule of elevators in a group. In this study, a fuzzy rules based intelligent elevator group control system has been proposed in which the structure of rules including the related parameters are generated optimally based on the traffic data so as to maximize service quality. In literature, the fuzzy related approaches have been applied in EGCS but the fuzzy rules were all pre-defined. However, how to create the most suitable fuzzy rule set in EGCS for dispatching elevators more efficiently and economically are never discussed in literature. The aim of the proposed approach is to minimize the average waiting time at peak hours as well as to minimize the power energy at off-peak hours by using the proposed fuzzy rule based ECGS. Moreover, there are many decision variables are considered in the GCGS to provide the most appropriate elevator assignment whenever any hall call is given. These variables include the number of elevators, traffic flow, direction, passenger preferences (for instance, department stores, hospitals, hotels, and office buildings), congestion and VIP priority floor, etc. In this study, a fuzzy rule based elevator-dispatching approach has been proposed for the EGCS in which the fuzzy rules and related parameters are derived optimally by using genetic algorithm based on the historical elevator transportation data. The experimental results show that the performance of the proposed approach is superior to these of traditional approaches in literatures.

Abstract: To enhance energy efficiency and reduce light pollution of overnight road lighting in suburban traffic, we propose a novel green transport system based on giant magnetoresistive (GMR) sensors. The basic principle is to detect the perturbation to the earth magnetic field by a ferrous vehicle with GMR sensors. This system can switch on the road lighting to full illumination gradually before the motor vehicle arrives and dim it out after the vehicle leaves without the driver noticing. Based on a sparse suburban road in the countryside of Hong Kong, a demonstration model was constructed to illustrate its feasibility. GMR sensors and the associated electrical energy control components including signal processors, relays, and dimmers were integrated into a complete system. The experimental result indicates that the sensing principle is feasible and the whole system can function together coherently to achieve over 90% energy saving. Such system can be scaled up to be implemented in real road conditions.

Abstract: Complaints reported by the public about faulty or damaged infrastructure are important information for the management and maintenance team. Nonetheless, existing system to manage the complaint reports often has the problem of insufficient and ambiguous description about the reported infrastructure which resulting difficulties for the management to take action. The troublesome process of filing a complaint report could have reduced the willingness of public to make a report. Therefore, this paper is to introduce solution to the situation through an infrastructure damage complaining system with location awareness and photo capturing capabilities. The proposed system has been developed and thus the purpose of this paper is to introduce the system from the perspective of system design and architecture and to discuss the practical implications of the system. The proposed system provides an instant and convenient approach for the public to file a complaint report about damaged or faulty infrastructure. The public only need to take a photo with their mobile device and the system will automatically embed the coordination of the facility into the photo with geo-tagging technique. The simplified process of filing a complaint report may encourage the public to be more willing to collaborate with management. The visual information in the photo and location of the facility provide useful for the management team to accurately assess the severity of the damage thus to be able take informed action. As the outcome, the proposed system helps to achieve more effective and efficient management of public infrastructure.

Abstract: It is known that the flexibility and programmable abilities have made the FPGA widely used as controllers to the electrical machines and systems. Above all, the high density of recent developed chip results in many of the CPU cores and complicated hardware can be programmed into the chip to be as controller. Thus, this topic is based on the currently available technologies of FPGA-based system design to the parallel processing. Software and hardware co-design are shown to reach the performance, and the system’s software stream data are processed with the hardware parallel technique. This analysis enables FPGA-based control system on the parallel computing platform to achieve the simultaneous operation for 3-axis motor motion and drive system control. In that way, we chose the high density FPGA, Altera Cyclone II EP2C8Q208C8N, as the chip to develop the hardware of microprocessor, motor drive and motion controller. The developed system was practically applied to a 3-axis motion platform driven by stepping motors to evaluate the system performance.