Browsing by Author "Jia, Huamin"

Now showing 1 - 16 of 16
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    4DT generator and guidance system
    (Cranfield University, 2015-10) Amaro Carmona, Manuel Angel; Jia, Huamin
    This thesis describes a 4D Trajectories Generator and Guidance system. 4D trajectory is a concept that will improve the capacity, efficiency and safety of airspace. First a 4D trajectories synthetizer design is proposed. A flight plan composed by a set of waypoints, aircraft dynamics model and a set of limits and constraints are assembled into an optimal control problem. Optimal solution is found by making use of an optimal control solver which uses pseudo spectral parametrization together with a generic nonlinear programming solver. A 4D Trajectories generator is implemented as a stand-alone application and combined with a graphic user interface to give rise to 4D Trajectories Research Software (4DT RS) capable to generate, compare and test optimal trajectories. A basic Tracking & Guidance system with proportional navigation concept is developed. The system is implemented as a complementary module for the 4D trajectories research software. Simulation tests have been carried out to demonstrate the functionalities and capabilities of the 4DT RS software and guidance system. Tests cases are based on fuel and time optimization on a high-traffic commercial route. A standard departure procedure is optimized in order to reduce the noise perceived by village’s population situated near airport. The tracking & guidance module is tested with a commercial flight simulator for demonstrating the performance of the optimal trajectories generated by the 4DT RS software.
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    ATC constraints and modelling in global ATM environment
    (Cranfield University, 2011-01) Dong, Wenfang; Jia, Huamin
    The United Kingdom’s Civil Aviation Authority published the national aviation forecast in 2008. The forecast predicts that domestic traffic will increase by 3.5% per year, and that international traffic will grow, on average, by 4.5% during 2010-2020. Based on this prediction, the traffic density will increase dramatically in the future, and airspace will be more and more congested. Usually, there are two potential solutions to deal with this situation: improving the ability of air traffic flow management is one solution; reducing the separation minimum of aircraft is another solution. However, this thesis focuses on the second solution, based on constraints of communication, navigation and surveillance systems (CNS). Cont?d.
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    Data fusion methodologies for multisensor aircraft navigation systems
    (Cranfield University, 2004-04) Jia, Huamin; Allerton, David J.
    The thesis covers data fusion for aircraft navigation systems in distributed sensor systems. Data fusion methodologies are developed for the design, development, analysis and simulation of multisensor aircraft navigation systems. The problems of sensor failure detection and isolation (FDI), distributed data fusion algorithms and inertial state integrity monitoring in inertial network systems are studied. Various existing integrated navigation systems and Kalman filter architectures are reviewed and a new generalised multisensor data fusion model is presented for the design and development of multisensor navigation systems. Normalised navigation algorithms are described for data fusion filter design of inertial network systems. A normalised measurement model of skewed redundant inertial measurement units (SRIMU) is presented and performance criteria are developed to evaluate optimal configurations of SRIMUs in terms of the measurement accuracy and FDI capability. Novel sensor error compensation filters are designed for the correction of SRIMU measurement errors. Generalised likelihood ratio test (GLRT) methods are improved to detect various failure modes, including short time and sequential moving-window GLRT algorithms. State-identical and state-associated fusion algorithms are developed for two forms of distributed sensor network systems. In particular, innovative inertial network sensing models and inertial network fusion algorithms are developed to provide estimates of inertial vector states and similar node states. Fusion filter-based integrity monitoring algorithms are also presented to detect network sensor failures and to examine the consistency of node state estimates in the inertial network system. The FDI and data fusion algorithms developed in this thesis are tested and their performance is evaluated using a multisensor software simulation system developed during this study programme. The moving-window GLRT algorithms for optimal SRIMU configurations are shown to perform well and are also able to detect jump and drift failures in an inertial network system. It is concluded that the inertial network fusion algorithms could be used in a low-cost inertial network system and are capable of correctly estimating the inertial vector states and the node states.
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    Development and simulation of hard real-time switched-ethernet avionics data network
    (Cranfield University, 2011-08) Chen, Tao; Jia, Huamin
    The computer and microelectronics technologies are developing very quickly nowadays. In the mean time, the modern integrated avionics systems are burgeoning unceasingly. The modern integrated modular architecture more and more requires the low-latency and reliable communication databus with the high bandwidth. The traditional avionics databus technology, such as ARINC429, can not provide enough high speed and size for data communication, and it is a problem to achieve transmission mission successfully between the advanced avionic devices with the sufficient bandwidth. AFDX(Avionics Full Duplex Switched Ethernet) is a good solution for this problem, which is the high-speed full duplex switched avionic databus, on the basis of the Ethernet technology. AFDX can not only avoid Ethernet conflicts and collisions, but also increase transmission rate with a lower weigh of the databus. AFDX is now adopted by A380,B787 aircraft successfully. The avionics data must be delivered punctualy and reliablely, so it is very essential to validate the real-time performance of AFDX during the design process. The simulation is a good method to acquire the network performance, but it only happends in some given set of scenarios, and it is impossible to consider every case. So a sophisticatd network performance method for the worst-case scenario with the pessimistic upper bound requires to be deduced. The avionic design engineers have launched many researches in the AFDX simulation and methods study. That is the goal that this thesis is aimming for. The development of this project can been planned in the following two steps. In the first step, a communication platform plans to be implemented to simulate the AFDX network in two versions – the RTAI realtime framework and Linux user space framework. Ultimately, these frameworks need to be integrated into net-ASS, which is an integrated simulation and assessment platform in the cranfield’s lab.The second step deduces an effective method to evaluate network performance, including three bounds(delay,backlog and output flow), based on the NC. It is called Network Calculus. It is an internet theory keeping the network system in determistic way. It is also used in communication queue management. This mathematics method is planed to be verified with simulation results from the AFDX simuation communication platform, in order to assure its validity and applicability. All in all, the project aims to assess the performance of different network topologies in different avionic architectures, through the simulation and the mathematical assessment. The technologies used in this thesis benefit to find problems and faults in the beginning stage of the avionics architecture design in the industrial project, especially, in terms of guarantee the lossless service in avionics databus.
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    Development of ground station display and flight management system for low-cost vehicle
    (Cranfield University, 2011-01) Pan, Jing; Jia, Huamin
    Nowadays, with the development of electronic and communication technologies, more and more low-cost vehicles such as small, light-weight aircraft are widely applied in all kinds of fields. Ground Station is an essential part of low cost vehicles for the operator to control and monitor the vehicles. In this thesis, Ground Station Display and Flight Management System for Low-Cost Vehicles have been developed.The major objective of this project is to design an intuitive and easy operative Human Machine Interface for displaying and monitoring the flight data and traffic information on ground. Meanwhile, a Graphic User Interface for the Flight Management System has been developed for realizing the waypoints input and flight plan for the vehicles. To fulfill this task, a low-cost hardware and software architecture is presented. Moreover, some COTS tools such as VAPS and MATLAB are applied for the software development because of their Object-Oriented and Rapid Prototype design methods. At the end of project, simulation has been done for the display HMI to test the behaviours of objects and the impacts of display. The trajectory simulation of flight management control panel is also implemented to test the waypoints creation, trajectory generation and smoothing.
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    Development of real-time flight control system for low-cost vehicle
    (Cranfield University, 2011-01) Du, Yongliang; Jia, Huamin
    In recent years, more and more light aircraft enter our daily life, from Agricultural applications, emergency rescue, flight experiment and training to Barriers to entry, light aircraft always have their own advantages. Thus, they have become more and more popular. However, in the process of GDP research about Flight Control System design for the Flying Crane, the author read a lot of literature about Flight Control System design, then noticed that the research in Flight Control System have apparently neglected to Low-cost vehicles. So it is necessary to do some study about Flight Control System for this kind of airplane. The study will more concern the control law design for ultra-light aircraft, the author hopes that with an ‘intelligence’ Flight Control System design, this kind of aircraft could sometimes perform flying tasks according to a prearranged flight path and without a pilot. As the Piper J-3 cub is very popular and the airframe data can be obtained more easily, it was selected as an objective aircraft for the control law design. Finally, a ¼ scale Piper J-3 cub model is selected and the aerodynamics coefficients are calculated by DATCOM and AVL. Based on the forces and moments acting on the aircraft, the trim equilibrium was calculated for getting proper dynamics coefficients for the selected flight conditions. With the aircraft aerodynamics coefficients, the aircraft dynamics characteristics and flying qualities are also analyzed. The model studied in this thesis cannot answer level one flying qualities in the longitudinal axis, which is required by MIL-F- 8785C. The stability augment system is designed to improve the flying qualities of the longitudinal axis. The work for autopilot design in this thesis includes five parts. First, the whole flight profile is designed to automatically control aircraft from takeoff to landing. Second, takeoff performance and guidance law is studied. Then, landing performance and trajectory is also investigated. After that, the control law design is decoupled into longitudinal axis and later-directional axis. Finally, simulation is executed to check the performance for the auto-controller.
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    Distributed data fusion algorithms for inertial network systems
    (Institution of Engineering and Technology, 2008-01-01T00:00:00Z) Allerton, David J.; Jia, Huamin
    New approaches to the development of data fusion algorithms for inertial network systems are described. The aim of this development is to increase the accuracy of estimates of inertial state vectors in all the network nodes, including the navigation states, and also to improve the fault tolerance of inertial network systems. An analysis of distributed inertial sensing models is presented and new distributed data fusion algorithms are developed for inertial network systems. The distributed data fusion algorithm comprises two steps: inertial measurement fusion and state fusion. The inertial measurement fusion allows each node to assimilate all the inertial measurements from an inertial network system, which can improve the performance of inertial sensor failure detection and isolation algorithms by providing more information. The state fusion further increases the accuracy and enhances the integrity of the local inertial states and navigation state estimates. The simulation results show that the two-step fusion procedure overcomes the disadvantages of traditional inertial sensor alignment procedures. The slave inertial nodes can be accurately aligned to the master node.
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    Ethernet-based AFDX simulation and time delay analysis
    (Cranfield University, 2016-02) Feng, Tao; Jia, Huamin
    Nowadays, new civilian aircraft have applied new technology and the amount of embedded systems and functions raised. Traditional avionics data buses design can‘t meet the new transmission requirements regarding weight and complexity due to the number of needed buses. On the other hand, Avionics Full Duplex Switched Ethernet (AFDX) with sufficient bandwidth and guaranteed services is considered as the next generation of avionics data bus. One of the important issues in Avionics Full Duplex Switched Ethernet is to ensure the data total time delay to meet the requirements of the safety-critical systems on aircraft such as flight control system. This research aims at developing an AFDX time delay model which can be used to analyse the total time delay of the AFDX network. By applying network calculus approach, both (σ,ρ) model and Generic Cell Rate Algorithm (GCRA) model are introduced. For tighter time-delay result, GCRA model is applied. Meanwhile, the current AFDX network simulation platform, FACADE, will be enhanced by adding new functions. Moreover, avionics application simulation modules are developed to exchange data with FACADE. The total time delay analysis will be performed on the improved FACADE to validate this AFDX network simulation platform in several scenarios. Moreover, each scenario is appropriated to study the association between total time delay performance and individual variable. The results from updated FACADE reflect the correlation between total time delay and certain variables. Larger BAG and more switches between source and destination end systems introduce larger total time delay while Lmax could also affect the total time delay. However, the results illustrate that the total time delays from updated FACADE are much larger than GCRA time delay model which could up to 10 times which indicates that this updated FACADE needs further improvement.
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    Methodology for avionics integration optimisation
    (Cranfield University, 2020-10) Radaei, Mohammad; Jia, Huamin; Lawson, C. P.
    Every state-of-art aircraft has a complex distributed systems of avionics Line Replaceable Units/Modules (LRUs/LRMs), networked by several data buses. These LRUs are becoming more complex because of the increasing number of new avionics functions need to be integrated in an avionics LRU. The evolution of avionics data buses and architectures have moved from distributed analogue and federated architecture to digital Integrated Modular Avionics (IMA). IMA architecture allows suppliers to develop their own LRUs/LRMs capable of specific features that can then be offered to Original Equipment Manufacturers (OEMs) as Commercial-Off-The-Shelf (COTS) products. In the meantime, the aerospace industry has been investigating new solutions to develop smaller, lighter and more capable avionics LRUs to be integrated into avionics architecture. Moreover, the complexity of the overall avionics architecture and its impact on cable length, weight, power consumption, reliability and maintainability of avionics systems encouraged manufacturers to incorporate efficient avionics architectures in their aircraft design process. However, manual design cannot concurrently fulfil the complexity and interconnectivity of system requirements and optimality. Thus, developing computer-aided design (CAD), Model Based System Engineering (MBSE) tools and mathematical modelling for optimisation of IMA architecture has become an active research area in avionics systems integration. In this thesis, a general method and tool are developed for optimisation of avionics architecture and improving its operational capability. The tool has three main parts including a database of avionics LRUs, mathematical modelling of the architectures and optimisation algorithms. The developed avionics database includes avionics LRUs with their technical specifications and operational capabilities for each avionics function. A MCDM method, SAW, is used to quantify and rank each avionics LRU’s operational capability. Based on the existing avionics LRUs in the database and aircraft level avionics requirements two avionics architectures are proposed i.e. AFCS architecture (SSA) and avionics architecture (LSA). The proposed avionics architectures are then modelled using mathematical programming. Further, the allocation of avionics LRUs to avionics architecture and mapping the avionics LRUs to their installation locations are defined as an assignment problem in Integer Programming (IP) format. The defined avionics architecture optimisation problem is to optimise avionics architecture in terms of mass, volume, power consumption, MTBF and operational capability. The problems are solved as both single-objective and multi-objective optimisation using the branch-and-bound algorithm, weighted sum method and Particle Swarm Optimisation (PSO) algorithm. Finally, the tool provides a semi-automatic optimisation of avionics architecture. This helps avionics system architects to investigate and evaluate various architectures in the early stage of design from an LRU perspective. It can also be used to upgrade a legacy avionics architecture.
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    Multidisciplinary methods for evaluation and optimisation of aircraft flight performance.
    (2017-10) Quaglia, Daniele; Jia, Huamin
    The aviation today is an increasing global market with 2.2 billion passengers travelling everyday due to the convenience that the air transportation has reached. Long term forecasts indicate that this growth will intensify and continue with a minimum of 2% passenger growth per year for the next two decades. This traffic growth will push to the limit the actual air traffic management and airspace systems that cannot handle such volume of increase traffic. The air transportation growth not only affects the current global air transportation system, but also has both local and global impacts on the environment. In addition, aviation also generates significant noisy environmental effects to the population living in the vicinity of the terminal area. Nowadays the aviation can use several procedures developed as first step for noise abatement and direct cost are managed by the on-board systems. The challenge is to introduce the future 4D trajectory management concept within on-board systems to manage the flight trajectory to optimize emissions, noise impact, contrails formation and also gate to gate flight time. Most of the previous studies have been focused on optimizing trajectories phases for a specifi c case only and without considering the operational level that need to be taken into account for a real gate to gate as described by the new Trajectory-Based Operations (TBO) concept. This report shows the work that has been done to create a virtual flight environment where the flight management systems can be tested and evaluated respect to those new requirements requested for the future generation air traffic rules. Trajectory optimization is implemented to calculate the optimal trajectory that minimize emissions and noise impact based on city pair air route in an operational level with realistic constraints and environment conditions. Multi-phase optimal control models the flight phases and control intermediate states of the aircraft. The ultimate trajectories are tested within the simulation environment to assess 4D trajectory performance and conceptual aircraft flight performances. The feedbacks can be used by the aircraft designers to modify the conceptual aircraft in the case the performances are not met.
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    Multiobjective imperialist competitive algorithm for solving nonlinear constrained optimization problems
    (De Gruyter, 2019-12-27) Liu, Chun-an; Jia, Huamin
    Nonlinear constrained optimization problem (NCOP) has been arisen in a diverse range of sciences such as portfolio, economic management, airspace engineering and intelligence system etc. In this paper, a new multiobjective imperialist competitive algorithm for solving NCOP is proposed. First, we review some existing excellent algorithms for solving NOCP; then, the nonlinear constrained optimization problem is transformed into a biobjective optimization problem. Second, in order to improve the diversity of evolution country swarm, and help the evolution country swarm to approach or land into the feasible region of the search space, three kinds of different methods of colony moving toward their relevant imperialist are given. Thirdly, the new operator for exchanging position of the imperialist and colony is given similar as a recombination operator in genetic algorithm to enrich the exploration and exploitation abilities of the proposed algorithm. Fourth, a local search method is also presented in order to accelerate the convergence speed. At last, the new approach is tested on thirteen well-known NP-hard nonlinear constrained optimization functions, and the experiment evidences suggest that the proposed method is robust, efficient, and generic when solving nonlinear constrained optimization problem. Compared with some other state-of-the-art algorithms, the proposed algorithm has remarkable advantages in terms of the best, mean, and worst objective function value and the standard deviations.
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    Obstacle detection with ultrasonic sensors and signal analysis metrics
    (Elsevier, 2018-02-03) Gibbs, Gerard; Jia, Huamin; Madani, Irfan
    One of the basic tasks for autonomous flight with aerial vehicles (drones) is the detection of obstacles within its flight environment. As the technology develops and becomes more robust, drones will become part of the toolkit to aid maintenance repair and operation (MRO) and ground personnel at airports. Currently laser technology is the primary means for obstacle detection as it provides high resolution and long range. The high intensity laser beam can result in temporary blindness for pilots when the beam targets the windscreen of aircraft on the ground or on final approach within the vicinity of the airport. An alternative is ultrasonic sensor technology, but this suffers from poor angular resolution. In this paper we present a solution using time-of-flight (TOF) data from ultrasonic sensors. This system uses a single commercial 40 kHz combined transmitter/ receiver which returns the distance to the nearest obstacle in its field of view, +/- 30 degrees given the speed of sound in air at ambient temperature. Two sonar receivers located either side of the transmitter / receiver are mounted on a horizontal rotating shaft. Rotation of this shaft allows for separate sonar observations at regular intervals which cover the field of view of the transmitter / receiver. To reduce the sampling frequency an envelope detector is used prior to the analogue-digital-conversion for each of the sonar channels. A scalar Kalman filter for each channel reduces the effects of signal noise by providing real time filtering (Drongelen, 2017a). Four signal metrics are used to determine the location of the obstacle in the sensors field of view: 1. Maximum (Peak) frequency 2. Cross correlation of raw data and PSD 3. Power Spectral Density 4. Energy Spectral Density Results obtained in an actual indoor environment are presented to support the validity of the proposed algorithm.
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    Redundant Multi-Mode Filter for a Navigation System
    (IEEE Institute of Electrical and Electronics, 2007-01-01T00:00:00Z) Allerton, David J.; Jia, Huamin
    An approach is introduced to the design of a multi-mode navigation filter to combine a low-cost skewed redundant inertial measurement unit (SRIMU) with a multifunctional GPS (MF-GPS) receiver in order to implement a fault-tolerant aircraft navigation system, which can achieve the required navigation performance of conventional systems in terms of accuracy, integrity, continuity, and availability. The MF-GPS receiver provides raw GPS measurements for pseudo- range and range rate to compute the navigation solutions (position and velocity) and also multi-antenna carrier phase interferometric measurements to estimate the aircraft attitude solution, if the carrier phase data is reliable. A multi- mode navigation filter is designed which combines state and measurement fusion methods and processes the SRIMU and raw MF-GPS outputs to provide reliable position, velocity and attitude information, and also kinematic parameters required in control, guidance, and navigation applications. The feasibility and performance of this integrated design is assessed and evaluated by using simulation. The accuracy of inertial gyros used in the evaluation ranges from 1 ± /h to 30 ± /h, including low-cost inertial sensor technologies. The simulation studies presented here show that a multi-mode navigation filter can achieve sufficient reliability and accuracy and that SRIMU/MF-GPS integrated navigation systems may provide a cost-effective system for future regional aircraft, general aviation aircraft, and unmanned aerial vehicle
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    Safety assessment methods for avionics software system
    (2017-11) Mao, Jiawen; Jia, Huamin; Madani, Irfan
    Nowadays, the avionics software has been becoming more and more critical for both civil and military aircraft. However, the software may become crazy sometimes and may cause the catastrophic result if any failure in software. Therefore, the software safety assessment is not only crucial to the specific software, but also for the system and aircraft. Although there are some industry standards as guidelines for development of software system, applications of these standards to practical software systems are still challenged and hard to operate in practice. This thesis tries to solve this problem. After analyses and summaries of the system safety assessment process and existing software safety assessment process in different fields, research wants to propose the systematic and comprehensive software safety assessment process and method for avionics software. The thesis presents the research process, and proposes one suitable avionics software safety assessment process. Meanwhile, thesis uses a real functional block in flight management system as a case study, and then conducts the software safety requirement assessment based on the proposed software safety assessment method. After analysis the result of case study, this proposed software safety assessment process and methods can quickly and correctly identify the software design errors. So, this analysis can use to prove the feasibility and validity of this proposed software safety assessment process and methods, which will help engineers modify every software design errors at the early stage in order to guarantee the software safety.
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    Short-term air traffic flow and capacity management measures in multi-airport systems.
    (2019-05) Amaro Carmona, Manuel Angel; Saez Nieto, Francisco; Jia, Huamin
    Dynamic Demand and Capacity Balancing (dDCB) focuses on reducing the existent gap between the Air Traffic Flow and Capacity Management (ATFCM) and the Air Traffic Control (ATC) activities by introducing a more dynamic management of the airspace resources. This dynamism could be achieved by the application of Short-Term ATFCM Measures (STAM) that consists of detecting potential hotspots, identifying the flights producing the complexity, and applying minor changes to selected flights. This thesis presents a research about the application of STAM in a Multi-Airport System (MAS). Firstly, it is proposed an Operational Concept (OpsCon) designed to apply those STAMs that suggest changes in the take-off time of selected flights (temporal displacements in the planned trajectory). The operational concept is tested by real-time simulations (including the human- in-the-loop) with the objective of evaluating the performance of the ground ATCOs while dealing with most of the uncertainties produced before take-off. Subsequently, it is proposed a methodology that characterizes and evaluates the performance of the aircraft operation in a complex systemized TMA based on the study of its standard routes and their actual traffic in order to reduce the uncertainties after take-off. The process is composed of two main components. The first component identifies recurrent deviation patterns by comparing the Spatio-Temporal (S-T) differences between the actual and planned trajectories. The second component identifies and characterizes concurrence events based on the analysis of the standard routes and the along-track deviation derived from the first component with the objective to analyse the causes that produce recurrent patterns in the terminal airspace. The developed framework is applied to a study case of a representative MAS. The quantitative effectiveness of the framework is derived by simulations using historical traffic data samples of the London TMA.
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    System level airborne avionics prognostics for maintenance, repair and overhaul
    (Cranfield University, 2016-02) Aman Shah, Shahani; Jia, Huamin
    The aim of this study is to propose an alternative approach in prognostics for airborne avionics system in order to enhance maintenance process and aircraft availability. The objectives are to analyse the dependency of avionic systems for fault propagation behaviour degradation, research and develop methods to predict the remaining useful life of avionics Line Replaceable Units (LRU), research and develop methods to evaluate and predict the degradation performances of avionic systems, and lastly to develop software simulation systems to evaluate methods developed. One of the many stakeholders in the aircraft lifecycle includes the Maintenance, Repair and Overhaul (MRO) industry. The predictable logistics process to some degree as an outcome of IVHM gives benefit to the MRO industry. In this thesis, a new integrated numerical methodology called ‘System Level Airborne Avionic Prognostics’ or SLAAP is developed; looking at a top level solution in prognostics. Overall, this research consists of two main elements. One is to thoroughly understand and analyse data that could be utilised. Secondly, is to apply the developed methodology using the enhanced prognostic methodology. Readily available fault tree data is used to analyse the dependencies of each component within the LRUs, and performance were simulated using the linear Markov Model to estimate the time to failure. A hybrid approach prognostics model is then integrated with the prognostics measures that include environmental factors that contribute to the failure of a system, such as temperature. This research attempts to use data that is closest to the data available in the maintenance repair and overhaul industry. Based on a case study on Enhanced Ground Proximity Warning System (EGPWS), the prognostics methodology developed showed a sufficiently close approximation to the Mean Time Before Failure (MTBF) data supplied by the Original Equipment Manufacturer (OEM). This validation gives confidence that the proposed methodology will achieve its objectives and it should be further developed for use in the systems design process.