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 presents a robust control scheme for the tracking control of singularly perturbed uncertain systems. The design problem is divided into two parts: tracking the reference trajectory and enhancing the robustness of the dynamic systems. By using the time-scale techniques, dynamic inversion approach and linear parameter-varying methods, a set of singularly perturbed state feedback controllers...
This paper addresses the problem of trajectory tracking control for an unmanned surface vehicle(USV) with unknown disturbances and input saturation. Let the saturation function is divided into a smooth function and a bounded function, the saturation function can be approximated by smooth function and the bounded function which can be treated as a system uncertainty. An auxiliary design system is employed...
This paper presents nonlinear robust trajectory tracking strategies for the hypersonic vehicle whose ailerons are stuck at an unknown angular position. Firstly, a time-varying sliding mode control strategy for general second-order systems is introduced, and the chattering of sliding mode controller is alleviated. Secondly, the dynamics of hypersonic vehicle are transformed into two second-order systems...
A new exponentially stable nonlinear control law is presented for trajectory tracking, hovering, and yaw motion tracking problems. Since linear motion of quadrotors is achieved via roll and pitch angles, a relationship between roll and pitch accelerations and motion trajectory is developed. An exponentially stable trajectory error dynamics is then formulated to derive the roll and pitch moments and...
The performance in any flight system depends on the feedback control scheme. Therefore, in a first stage, we apply as a basis the so-called Model Free Control (MFC) for the development of nonlinear flight control law that could be implemented without much difficulty. As second step, an in-depth discussion with respect to the control performance is highlighted. Due to the novel form that we propose,...
In this paper, we present a novel notion of input-to-state safety (ISSf) for general nonlinear systems which can be useful for certifying system's safety under the influence of external bounded input (or disturbance) signals. We provide sufficient conditions for ISSf using barrier function/certificate which are analogous to the input-to-state stability Lyapunov function.
In this work we consider a variety of notions related to external stability, i.e., input-to-output stability, for nonlinear systems with time delays. As known for delay-free systems, there are different ways of defining precisely the notions of input-to-output stability that are intrinsically different from each other. The main objectives of this work are to illustrate the relations among the different...
A tractor-trailer wheeled robot (TTWR) is a kind of modular robotic system that consist of the tractor and the trailer are mechanically coupled to each other. It is impossible to obtain an exact dynamics model due to unknown parameters, or unpredictable and irregular features, external disturbance. Because of the non-holonomic constraints property, this paper proposes an adaptive robust cascade controller...
Variable structure filter (VSF) is a robust filter for linear uncertain system. In order to remove the chattering caused by high-frequency gain switching of VSF, the smoothing boundary layer (SBL) has been introduced. And similar to Kalman filter, the optimal state estimation of VSF can be got at the optimal smoothing boundary layer (OSBL). However, in practical applications, the statistical characteristics...
Data association, which could be categorized into offline approaches and the online counterparts, is a crucial part of a multi-object tracker in the tracking-by-detection framework. On the one hand, classical offline data association methods exploit all the video data and have high computation cost, which makes them unscalable to long-term offline video data. On the other hand, online approaches have...
When used as part of a hybrid controller, finite-memory strategies synthesizedfrom linear-time temporal logic (LTL) specifications rely on an accurate dynamics model in order to ensure correctness of trajectories. In the presence of uncertainty about the underlying model, there may exist unexpected trajectories that manifest as unexpected transitions under control of the strategy. While some disturbances...
The output tracking control problem is considered for a class of uncertain nonlinear systems with time delays and dead-zone inputs. A simple design method is proposed so that a class of adaptive robust output tracking control laws can be synthesized. In particular, the synthesized controllers have a rather simple structure, and can be easily realized in practical engineering control systems. In this...
This article addresses the problem of quadrotors following a path geometry under the action of a constant external disturbance and with partial state measurement. To solve these issues, under the assumption of time scale separation between the translational dynamics and the closed-loop rotational dynamics, we propose an integral output robust maneuvering controller in combination with a translational...
This paper discusses the possibility of using the geometric shape of a pedestrian's head to shoulder region as a feature to identify individuals. The main aim is to track humans in a high density crowd using a 3D laser range finder (3D-LRF). One of the most critical problems of human tracking in a high density crowd is the occurrence of occlusion. Occlusion might occur because of the lack of features...
This paper presents an overview of various methods used to minimize the fluctuating impacts of power generated from renewable energy sources. Several sources are considered in the study (biomass, wind, solar, hydro and geothermal). Different control methods applied to their control are cited, alongside some previous applications. Hence, it further elaborates on the adoptive control principles, of...
Iterative learning control demands the same initial state in each iteration, which is equal to the desired state. But this condition is unattainable in practice. This paper addresses the problem of some fixed initial state in iterative learning control for high-order nonlinear system. It presents a new control algorithm. In the process of tracking, this algorithm can rectify the initial errors through...
In this paper, we present an iterative learning control (ILC) frameworks for robust path-tracking problem of nonholonomic mobile robots in the presence of initial shifts. The major difficulties are owning to the simultaneous existence of state disturbances and biased initial state in the mobile robot kinematic system. To design ILC strategy for such problem, a new ILC scheme is proposed as a combination...
Parameter interval based fault isolation for single parameter fault has ideal isolation speed, the fault parameter value is estimated when fault is isolated. Analogous scheme can be built for multi-parameter fault isolation using envelope to replace scalar threshold for interval judgment. However wrapping effect should be considered when envelope is used. In this paper a multi-parameter fault isolation...
This paper considers a nonsingular terminal sliding mode control problem for the attitude tracking of a quadrotor. To solve the chattering problem of sliding mode control, a novel terminal sliding mode controller based on a second-order sliding mode algorithm known as super-twisting algorithm is proposed. With the help of the proposed terminal sliding mode controller, the pitch, roll and yaw angles...
This work addresses the problem of motion planning among obstacles for quadrotor platforms under external disturbances and with model uncertainty. A novel Nonlinear Model Predictive Control (NMPC) optimization technique is proposed which incorporates specified uncertainties into the planned trajectories. At the core of the procedure lies the propagation of model parameter uncertainty and initial state...
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.