Search

We need a coordinated control method to continuously track a moving target using a group of UAVs. In this paper, we study the predicted reference point guidance method, where the target is considered to move with a constant velocity in a very short time window and the trajectories of the UAVs are designed as several tiny arcs around the target. The control law of the UAV is divided into roll angle control and velocity control. Simulations are used to verify that the proposed control laws have smaller standoff distances and phase angle control errors than the Lyapunov vector field guidance and model-based predictive control, and the wind is considered in the simulation, too. Therefore, we show that our proposed method has higher steady state accuracy among existing techniques.

This paper presents a vision/radar/INS integrated guidance system for shipboard landing. The vision system on the aircraft tracks landmarks on the ship and outputs their coordinates in the image. The motion information of aircraft is obtained from airborne inertial navigation system (INS). Meanwhile, the datalink receives the relative position between the ship and aircraft from the shipboard radar and the ship motion information from shipboard sensors. The federated filter is utilized to fuse the vision, radar and inertial information, and the information from INS is chosen as the reference system in the federated filter. The estimated ship motion information is utilized to calculate the glide-down path. All the guidance information is regarded as the feedback information given to the flight control system to calculate control command. A designed on-vehicle experiment shows that the vision/radar/INS integrated landing guidance system achieves satisfied results. [ABSTRACT FROM AUTHOR]

Most large commercial aircraft use a flight management system (FMS) to provide aircraft state estimation, trajectory prediction, lateral and vertical guidance, flight plans, and target setpoints (e.g., optimal cruise speed), among other functionality [1]. With unmanned aerial vehicles (UAVs) gaining popularity in commercial and military applications [2], the integration of UAVs in shared airspace with current aircraft has become an important problem to address. There has been consideration for the use of unmanned aircraft for package delivery with the use of small quadrotor UAVs for local demand [3] and large unmanned commercial aircraft for shipping goods internationally [4]. With the UAV industry poised to grow [2], one must consider how to integrate UAVs with the current systems for manned aircraft. Due to the importance of FMS to aircraft, a logical step would be to consider an FMS for UAVs that can adhere to current aircraft regulations and protocols. Flight management systems for UAVs can involve certification, collision detection, mission planning, and many other topics. One can find a number of simulated FMS for consumer flight simulators (i.e., Microsoft Flight Simulator and X-Plane [6]) that try to replicate the interface and functionality of currently available flight management systems. The purpose of this article is to take this idea further by building an FMS in software that can interface with real aircraft and UAVs using industry standard communication protocols. [ABSTRACT FROM AUTHOR]

This paper proposes a novel pilot control model which reflects the following three characteristics of the pilot control behavior: stochastic, periodical, and discrete movement. The focus is on the final descent phase when the pilot controls the aircraft manually based on the flight director commands. The proposed model is developed based on an existing model as well as highly experienced pilot's comments. A flight simulator experiment is conducted and three pilots’ landing data are obtained. The parameters of the pilot model are tuned via a genetic algorithm. The simulation result reveals that the proposed model captures well the characteristics of the data obtained in the simulator experiment and shows a good accordance with actual command tracking capability. The obtained parameters also identify the difference of control strategies between the pilots. [ABSTRACT FROM PUBLISHER]

Many social insects, such as desert ant and honeybees, are able to utilize the natural skylight polarization information for navigation, which has advantages in immunity to the interference of external environment and thus shows higher stability and accuracy. Inspired by it, we attempt to explore a new bionic method for attitude determination by use of polarization pattern. In practice, we first capture the polarization data and based on it, to figure out the location of the sun through clustering. Then, with respect to the relatively consistent spatio-temporal relation between the sun and the zenith, the location of the zenith is accordingly determined. The coordinate of the zenith is adopted to establish the attitude rotation matrix and by which to work out the vehicle’s attitude. Finally, we set up a simulation vehicle platform to test the effectiveness of the approach with the theoretical polarization pattern derived from the Rayleigh single-scattering theory and actually detected pattern by the polarization analyzer. [ABSTRACT FROM PUBLISHER]

Avionics (aviation electronics) has been evolving for over a century which had a surge during the late 1940s from both World War II and the founding of the Professional Group on Airborne Electronics (PGAE) in February 1955 [14]. Since that time, IEEE has been a source of literature contributions in avionics from the inaugural Aeronautical and Navigational Electronics (ANE) group followed by the name changes to the Aerospace and Navigational Electronics (ANE) to the current Aerospace and Electronics Systems Society (AESS). The society's name variations demonstrate the importance of electronics in support of aviation developments. [ABSTRACT FROM PUBLISHER]

Polarized skylight pattern is one of the earth’s natural traits, which can provide compass cues for some insects’ navigation. Decades of behavioral and anatomic studies of the mechanisms that insects employed have found that some insects can home unfailingly through detecting the polarized skylight with their sophisticated compound eyes. Largely counting on the natural skylight, their navigation is immune to the interference of external environment and shows advantages in stability and accuracy over the conventional navigating devices, which sheds new light on the detection of skylight polarization pattern for attitude determination since it is the first concern for aerial vehicles to achieve accurate navigation. In this paper, we take the biological research as the guidance to simulate and detect the real-time polarized skylight pattern. In addition, with the polarization data, we are trying to explore a new algorithm to solve the three attitude angles, and test the validity of the algorithm with actual simulation experiment, just aiming at the purpose of finding an unambiguous way of attitude determination. [ABSTRACT FROM PUBLISHER]

This paper studies the problem of aircraft midair conflict resolution, which is a key technology to enable the coordinated and decentralized air traffic control envisioned in the Next Generation Air Transportation System (NextGen). The method proposed in this paper is based on stochastic optimal control, which is able to incorporate uncertainties in both aircraft and wind dynamics. The proposed numerical algorithm uses a Markov chain (MC) to approximate the continuous-time aircraft and wind dynamics, then the optimal control law is derived based on the MC. The proposed algorithm is able to resolve the conflicts between aircraft and moving convective weather regions. For conflict resolution between pairs of aircraft, a decomposition technique is proposed to reduce the computational complexity of the numerical algorithm. Simulations show that the proposed algorithm provides robustness against uncertainties in the system and is suitable for real applications. [ABSTRACT FROM PUBLISHER]

We present an algorithm for the distributed navigation and conflict avoidance of nonholonomic aircraft-like agents in 3-D space. The proposed feedback control scheme offers improved applicability to aircraft navigation and compatibility with Air Traffic Management practice with respect to previous work. Our approach aims to maintain a desired horizontal velocity for each aircraft, while limiting the climb or descent angle within bounds according to aircraft performance characteristics. Moreover, the algorithm is designed to favor straight and level flight, resulting in more sensible manoeuvres that require reduced steering effort. The proposed control scheme is based on the Navigation Functions methodology and offers formally guaranteed conflict avoidance and convergence properties. The performance characteristics of our method are demonstrated through simulation results. [ABSTRACT FROM AUTHOR]

The SINS with IMU rotated is the high performances position measurement system based on the fiber optic gyroscopes. We have presented a theoretical and experimental study of the IMU rotation. Several experiments have proven that the combination of the SINS with IMU rotation achieves very high performance. SINS size and weight make it particularly suitable as the position measurement system of the small vehicles for which precise position with meter or sub-meter level is a critical issue. The experimental results showed that, the position errors which are calculated by SINS with IMU rotation, are much less than IMU static. Where, the position error which is caused by IMU double-axis rotation is 1.47 nm, which is much less than IMU single-axis rotation 6.06 nm. Therefore, the proposed position determination method is highly beneficial in providing accurate position of vehicle for several navigation applications, such as Missile boat and helicopter take off and landing platform on the aircraft carrier, etc. [ABSTRACT FROM PUBLISHER]

Inspection aircraft equipped with cameras and other sensors are routinely used for asset location, inspection, monitoring, and hazard identification of oil-gas pipelines, roads, bridges, and power transmission grids. This paper is concerned with automated flight of fixed-wing inspection aircraft to track approximately linear infrastructure. We propose a guidance law approach that seeks to maintain aircraft trajectories with desirable position and orientation properties relative to the infrastructure under inspection. Furthermore, this paper also proposes the use of an adaptive maneuver selection approach, in which maneuver primitives are adaptively selected to improve the aircraft's attitude behavior. We employ an integrated design methodology particularly suited for an automated inspection aircraft. Simulation studies using full nonlinear semicoupled six degree-of-freedom equations of motion are used to illustrate the effectiveness of the proposed guidance and adaptive maneuver selection approaches in realistic flight conditions. Experimental flight test results are given to demonstrate the performance of the design. [ABSTRACT FROM AUTHOR]

The characterization of complex air traffic situations is an important issue in air traffic management (ATM). Within the current ground-based ATM system, complexity metrics have been introduced with the goal of evaluating the difficulty experienced by air traffic controllers in guaranteeing the appropriate aircraft separation in a sector. The rapid increase in air travel demand calls for new generation ATM systems that can safely and efficiently handle higher levels of traffic. To this purpose, part of the responsibility for separation maintenance will be delegated to the aircraft, and trajectory management functions will be further automated and distributed. The evolution toward an autonomous aircraft framework envisages new tasks where assessing complexity may be valuable and requires a whole new perspective in the definition of suitable complexity metrics. This paper presents a critical analysis of the existing approaches for modeling and predicting air traffic complexity, examining their portability to autonomous ATM systems. Possible applications and related requirements will be discussed. [ABSTRACT FROM PUBLISHER]

Herein we provide an operational sequence indentifying a set of future roles and responsibilities for Air Navigation Service Provider (ANSP) and flight operator staff. It also identifies procedures and technologies necessary to support activities proposed withing future operational concepts for an Integrated Arrival/Departure Control Service, Dynamic Departure Routing, and airport surface management, with a focus on near- to mid-term (2015–2018) technical capabities. This operational sequence is then utilized to identify critical human factors considerations at an abstract level. The operational sequence is organized according to a timeline and the assumed context for the scenario. All times are reported in Zulu (Greenwich Mean) Time. [ABSTRACT FROM PUBLISHER]

Robust and early detection of oscillatory failures in the electrical flight control system of an aircraft is a crucial issue. Oscillatory failures, if not detected and passivated in time, can lead to strong interactions with loads and aeroelasticity and may potentially lead to structural damages. A nonlinear observer-based solution to detect such failures with small amplitude at a very early stage is presented. The stability and convergence proofs are given and experimental results with real A380 flight data are presented. [ABSTRACT FROM AUTHOR]

Motivated by spectral separation, guidance and control systems of interceptors are traditionally designed separately. However, interception of highly maneuverable targets and increased interception accuracy requirements lead to intense maneuvering during the last phase of the engagement, thus violating the spectral separation assumption of the conventional two-loop design. This has boosted the interest in integrated guidance-control designs that demonstrate superior interception accuracies by accounting for the coupling between the kinematics and dynamics of the problem. One of the approaches used for the integrated design is the sliding mode control (SMC) methodology. The results presented so far assumed full state information. We examine the effect of estimation on the performance of the integrated sliding mode controller design. In particular, a sliding mode observer/differentiator (SMOD) is used to estimate the target states. Through an intensive numerical study it is shown that the integrated guidance-control approach has a clear advantage over a conventional separated two-loop design. This advantage is attributed to the robustness of the integrated sliding mode controller design that better deals with the estimation errors and measurements noises. [ABSTRACT FROM AUTHOR]

One current method of aircraft flightpath generation employs multi-segmented straight trajectories with each consecutive pair of segments filleted with arcs of constant radius. A difficulty of infeasibility immediately arises. In order for an aircraft to make the transition from a straight to a curved path segment (or vice versa) there is a physical requirement for a step acceleration, implying an infinite jerk. Clothoid curves provide a solution and have been investigated to fillet the consecutive segments. However, in this case, the mathematical definition of the clothoid is in terms of an integral that precludes closed-form solutions for critical guidance parameters. The attractiveness of the clothoid is to solve the physical infeasibility problem, however the mathematical intractability inherent in the approach has attracted limited attention despite being recognised as a major concern through early experiments. A method is presented here where double clothoid curves are used to fillet consecutive segments. This work goes beyond present practice to provide closed form solutions by using the hyperbola as a clothoid facsimile. Acceleration constraints have been enforced, both accumulative and maximum, and both the reference bank angle and bank angle rate have been expressed analytically in closed-form in terms of hyperbolic parameters. The solution can be optimised in terms of accumulative acceleration and path length, whilst simultaneously enforcing maximum acceleration constraints. This method of trajectory generation is attractive for implementation with air traffic management separation assurance, tunnel-in-the-sky, and other proposed cockpit display systems. [ABSTRACT FROM AUTHOR]

This describes the range of aircraft location vertical finders to determine pitch and roll angles. The devices mentioned reflect the main stages of the attitude control system development throughout history at the Control Device Department of Tula State University, ranging from classical platform systems to micromechanical and pyrometer strap-down attitude reference systems. A multi-functional attitude gyroscope based on two two-degrees-of-freedom gyros driven by electric gyro motors has been discussed as a classical platform attitude gyroscope. Strap-down vertical references are represented by system samples based on micromechanical inertial sensors and pyrometer detectors. This provides the specifications of vertical references concerned and performs the comparative analysis thereof. It also shows the advantages and disadvantages of each of these systems. [ABSTRACT FROM PUBLISHER]