The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This paper focuses on the inspection for sloping dam wall by a remotely operated vehicle (ROV). First, a dedicated ROV for dam inspection is described. Second, a fixed-distance tracking control strategy is proposed to guarantee the fixed camera-to-subject distance in sloping dam inspection, which is instrumental in sonar image fusion for the large-scale dam wall with a certain inclination. In addition,...
This paper presents an approach to trajectory tracking control for autonomous vehicles subject to parametric uncertainties. Such uncertainties may have the potential to significantly decrease the performance of the system, even to the point of destabilizing it. Therefore, these parametric variations must be taken into account during the design of the controller. To solve the trajectory tracking problem...
Five stabilizing controls for discrete-time quasilinear control systems based on the solution of the Discrete-Time State Dependent Riccati Equation (D-SDRE) are examined. One of the approaches has been proposed by the authors and uses the approximate solution of the D-SDRE. The main goal of this paper is to obtain the results on comparative computational characteristics of the discussed control synthesis...
Manual annotations of temporal bounds for object interactions (i.e. start and end times) are typical training input to recognition, localization and detection algorithms. For three publicly available egocentric datasets, we uncover inconsistencies in ground truth temporal bounds within and across annotators and datasets. We systematically assess the robustness of state-of-the-art approaches to changes...
This paper proposes an adaptive control for a rigidlink, flexible-joint robot using the Cerebellar Model Articulation Controller (CMAC) and the backstepping method, which is a suitable method when joints are underdamped and exhibit a large amount of flexibility. A previously proposed robust weight update method, deemed the introspective method, is placed into a Lyapunov-stable framework. In the introspective...
Model Predictive Control (MPC) is a candidate solution to aggressively control a constrained plant. In Tube Model Predictive Control (TMPC), optimality is traded for robustness which is a key aspect in flight controls where the plant is subject to many disturbances and uncertainties especially related to aerodynamics and wind. Yet MPC comes with large computational effort and thus reduced execution...
This work studies the robust stabilization problem of non-triangular delayed nonlinear system. The considered system involves the uncertain dynamics, unknown control coefficient and time delay. By employing a novel Lyapunov-Krasovskii functional and using the backstepping method, we raise a robust controller to guarantee the states of the system bounded. An example is given to verify the validity...
This paper presents a new cascade control architecture formulation for addressing the problem of autonomous vehicle trajectory tracking under risk and comfort constraints. The integration of these constraints has been split between an inner and an outer loop. The former is made of a robust controller dedicated to stabilizing the car dynamics while the latter uses a nonlinear Model Predictive Control...
This paper details the design of an autonomous vehicle CAD toolchain, which captures formal descriptions of driving scenarios in order to develop a safety case for an autonomous vehicle (AV). Rather than focus on a particular component of the AV, like adaptive cruise control, the toolchain models the end-to-end dynamics of the AV in a formal way suitable for testing and verification. First, a domain-specific...
Modern control systems, like controllers for swarms of quadrotors, must satisfy complex control objectives while withstanding a wide range of disturbances, from bugs in their software to attacks on their sensors and changes in their environments. These requirements go beyond stability and tracking, and involve temporal and sequencing constraints on system response to various events. This work formalizes...
For low hitting precision, bad robustness and high normal acceleration of traditional torpedo guidance law, the paper designed anti-torpedo torpedo(ATT) guidance law based on variable structure control. State equation of line of sight angle between ATT and target can be achieved from mathematical model of moving relation between ATT and target torpedo, and designed a variable structure controller...
Three-degree-of-freedom trajectory tracking of the stratospheric airship is investigated. With a simplified planar dynamic model, an adaptive backstepping sliding mode controller is designed to keep the airship to globally asymptotically track a desired trajectory. Lyapunov functions are used to ensure the tracking performance when model parametric uncertainty and external disturbances exist. Simulation...
Model-based predictive control is an effective method for control the large scale systems. Method is based on on-lin solution of control task over the control horizon using current and past measurements as well as the system model. Because model and measurement uncertainty, predicted and plant outputs might be different and plant output may exceed plant output constraints. Generated control is not...
To solve the ascent guidance of reusable launch vehicle (RLV) under the uncertain condition, a robust guidance method based on combing feedback linearization and H-infinity optimization theory is proposed. The article establishes the RLV ascending dynamic models. According to the characteristics of the ascending flight, the height deviation is converted into a linear relationship with pitch angle...
For the trajectory tracking in three degrees of freedom underactuated ships with parameters uncertainties and time-varying disturbances, a robust sliding-mode methodology is proposed. The ship's mass matrices are not assumed to be diagonal, as often required in the literature. Based on the coordinate transformations, the nonzero off-diagonal matrices are turned into the diagonal matrices. The controller...
Constant-Power Load (CPL) introduces destabilizing effect to dc-dc converters, which may lead to voltage oscillation or collapse. To mitigate the destabilizing problem brought by CPL, a nonlinear boundary controller is proposed in this paper, which has a nonlinear switching line. The converters' dynamics on the state space plane is analyzed through phase portrait. The proposed controller is verified...
RGB-D scanning of indoor environments is important for many applications, including real estate, interior design, and virtual reality. However, it is still challenging to register RGB-D images from a hand-held camera over a long video sequence into a globally consistent 3D model. Current methods often can lose tracking or drift and thus fail to reconstruct salient structures in large environments...
We present new methods of simultaneously estimating camera geometry and time shift from video sequences from multiple unsynchronized cameras. Algorithms for simultaneous computation of a fundamental matrix or a homography with unknown time shift between images are developed. Our methods use minimal correspondence sets (eight for fundamental matrix and four and a half for homography) and therefore...
In this paper, we consider the leader-follower consensus problem of multi-agent systems governed by second order dynamics with nonlinear terms. Taking into account the external disturbances, a leader-follower consensus tracking algorithm for each agent with high-order sliding mode control method is proposed to make all the followers track the leader. Then we prove that each agent can follow the leader...
In this paper, a robust adaptive backstepping control scheme is studied for attitude and altitude control of medium-scale unmanned autonomous helicopter (UAH) with flapping dynamics. A simplified UAH model is established and nonlinear disturbance observer (NDO) is designed to eliminate the effect of unknown external disturbance. The robust adaptive backstep-ping approach is employed to design the...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.