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The recent build-up network of Automatic Identification System (AIS) equipped on vessels provides a rich source of vessel movement information. AIS is originally designed for automatically exchanging navigation information, such as their unique identification, position, course, and speed, with nearby vessels and terrestrial receivers to affect collision avoidance and safety control. The collected...
We address the problem of rendezvous between two agents in urban street networks. Specifically, we consider the case where the agents have variable speeds and they need to schedule a rendezvous or a meeting under uncertainty in their travel times. Examples of such a scenario range from everyday life where two people would like to coordinate a meeting while going from office to home; to a futuristic...
Soft sliding mode control (SSMC) strategy is given for discrete-time systems with uncertainties by the reaching law with active disturbance rejection function in this paper. The reason of causing chattering is analyzed and a discrete reaching law with boundary layer is developed. A grayscale algorithm is presented for uncertainties and the estimates of parameters are obtained appropriately. Soft sliding...
In foot-mounted positioning systems, it is hard to align multi-agent trajectories. In addition, the positioning accuracy is hard to maintain due to inertial drifts. An approach for trajectory initialization and calibration using iBeacons is proposed in this paper. This approach is under the framework of a particle filter. In the observation model of the particle filter, a nonparametric Gaussian Process...
Path planning of the unmanned aerial vehicle(UAV) under the condition of uncertainty of environment remains a challenge because of many constraints. In this paper, a multiple unmanned combat aerial vehicle (multi-UCAV) cooperative autonomous attack path planning method under complex and uncertain environment is put forward. A general framework of multi-UCAV cooperative combat and autonomous attack...
In this paper, we prove that the DOB-based feedback controller can guarantee arbitrarily large but bounded gain margin and phase margin. This fact reminds that the DOB-based controller plays the role of robust controller even in the classical sense. We present a design procedure that ensures desired gain/phase margin even for the plants that have parametric uncertainty.
This paper considers the control problem for a class of sensor delay systems with nonlinear unknown dynamics and external disturbances. The extended state predictor observer (ESPO) based active disturbance rejection control (ADRC) is first proposed to timely estimate and compensate for the "total disturbance" under sensor delay. The timedomain stability of the closed-loop system is rigorously...
Trajectory-Based Operations require the development and execution of a trajectory-based plan which is subject to uncertainty as a result of trajectory prediction inaccuracy and disturbances. The impact of disturbances due to conflict detection/resolution and traffic synchronization are evaluated under different levels of prediction inaccuracy through Monte Carlo Simulation. Conflicts are estimated...
Air traffic in the North Atlantic oceanic airspace (NAT) experiences very strong winds caused by jet streams. Flying wind-optimal trajectories increases individual flight efficiency, which is advantageous when operating in the NAT. However, as the NAT is highly congested during peak hours, a large number of potential conflicts between flights are detected for the sets of wind-optimal trajectories...
In this article, we test a horizontal detect and avoid algorithm for UASs flying in Terminal Control Areas. We have used recorded commercial traffic trajectories and randomly built thousands of conflict scenarios with UASs to check the ability of such an algorithm to ensure the separation with commercial aviation. We consider two different types of UASs, flying at 80kn or 160kn, with six different...
A Human-In-The-Loop simulation was conducted in January of 2013 in the Airspace Operations Laboratory at NASA's Ames Research Center. The simulation airspace included two en route sectors feeding the northwest corner of Atlanta's Terminal Radar Approach Control. The focus of this paper is on how uncertainties in the study's trajectory predictions impacted the controllers' ability to perform their...
Continuous Descent Operations (CDO) with Controlled Times of Arrival (CTA) at one or several metering fixes could enable environmentally friendly procedures without compromising airspace capacity. Extending the current capabilities of state-of-the-art Flight Management Systems (FMS), the Time and Energy Managed Operations (TEMO) concept is able to generate optimal descent trajectories with an improved...
We propose a new impedance controller using a multi-time-scale structure. Extended High-Gain Observers in the fastest time scale are used to estimate unmeasured system states and uncertainties in systems. Dynamic inversion in the second fastest time scale is employed to deal with uncertain input coefficients. An implicit tracking for joint-space control of workspace trajectories is realized through...
This paper introduces the concept of functional diagnosability for nonlinear dynamical uncertain models. Set-membership functional diagnosability is based on the notion of functional signature introduced in [11] extended to the set-membership framework. The link between functional diagnosability and set-membership functional diagnosability is established. Contrary to classical definitions, the study...
In this paper, we propose an optimization scheme for avoiding void zone and minimization of uncertainty in glider's position estimation. Gliders stay at sojourn positions for predefined time. At these stops, self-confidence (s-confidence) and neighbor-confidence (n-confidence) regions are estimated. On the basis of present state of glider, it estimates s-confidence region and share control information...
The control of nonlinear dynamic systems is often a challenging task for practical applications if the process model under consideration is significantly influenced by uncertain parameters and bounded (additive) uncertainty and if it has to be guaranteed simultaneously that specific state constraints are not violated. According to previous work, the handling of bounded uncertainty becomes possible...
In recent years, privacy preserving trajectory data publishing has gained widespread attention. Aiming at the trajectory anonymity issues in publishing trajectory data of moving target, using the inherent uncertainty of the trajectory acquisition system, and based on the case that the uncertain threshold of trajectory is variable in practical applications, the traditional (k, δ)-anonymous model was...
Over the years, autonomous systems have entered almost all the facets of human life. Gradually, higher levels of autonomy are being incorporated into cyber-physical systems (CPS) and Internet-of-things (IoT) devices. However, safety and security has always been a lurking fear behind adoption of autonomous systems such as self-driving vehicles. To address these issues, we develop a framework for quantifying...
Automated riving is becoming the focus of various research institutions and companies. In this context, road estimation is one of the most important tasks. Many works propose to realize this task by employing one or multiple of the following orthogonal information sources: road markings from optical lane recognition, leading vehicle, digital map. etc. Each of them has its own strength and drawbacks...
An adaptive iterative learning control (AILC) is proposed to release the requirement of repetitiveness for a class of multiple-input multiple-output nonlinear systems. Based on high-order internal model, the time-iteration-varying law of parametric uncertainty is expressed. Furthermore, reference trajectory and initial state are varying from iteration to iteration randomly. The asymptotic convergence...
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