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In the paper, we firstly give a new accurate spheroid estimation formula of the globally exponentially attractive set for all positive parameters by constructing a generalized positive definite Lyapunov functions with radially unbound. Secondly, based on inequalities techniques, linear feedback control with one input or two inputs is proposed to realize the globally exponential synchronization of...
This paper introduces a new chaotic system. Some basic dynamical properties are studied, such as the equilibria, the Lyapunov exponents and the fractal dimension. Based on these properties, effective feedback controllers are proposed for stabilizing chaos to unstable equilibria. In addition, based on Lyapunov stability theory, sufficient condition for the synchronization has been analyzed theoretically...
In this paper, a robust fault-tolerant control strategy for constrained multisensor linear systems, subject to sensor faults and in the presence of bounded state and output disturbances is proposed. The scheme verifies that for each sensors-estimator combination, suitable residual variables lie inside pre-computed sets and selects the more appropriate combination based on a chosen criterion. An active...
Percutaneous interventions have attracted significant interest in recent years, but most approaches still rely on straight line trajectories between an entry site and a soft tissue target. Thus, to this day, a flexible probe able to bend along predefined curvilinear trajectories within a highly compliant medium without buckling is still an open research challenge. In this paper, we describe the concept...
In this study we develop a feedback controller for a four wheeled autonomous mobile robot. The purpose of the controller is to guarantee robust performance of an aggressive maneuver (90 degrees turn) at high velocity (about 10 m/s) on a loose surface (dirty road). To tackle this highly nonlinear control problem, we employ multi-objective evolutionary algorithms to explore and optimize the parameters...
This paper develops full-state parametric controllers for standing balance of humanoid robots in response to impulsive and constant pushes. We also explore a hypothesis that postural feedback gains in standing balance should change with perturbation size. From an engineering point of view this is known as gain scheduling. We use an optimization approach to see if feedback gains should scale with the...
A new control strategy based on feedback motion planning is presented for solving nonlinear control problems in constrained environments. The algorithm explores the state-space using a bi-directional rapidly exploring random tree (biRRT) in order to find a feasible trajectory between an initial and goal state. By incrementally scheduling LQR controllers, it attempts to connect states so as to link...
The paper presents a nonlinear filtering technique that can be adopted to generate smooth trajectories for mobile robotic applications. The proposed trajectory planner can be fully executed online by the robot control system, thanks to its inherently discrete-time behavior and to its limited computational requirement. The outputs of the nonlinear filter used as a trajectory planner include the derivatives...
The performance of a soccer robot is highly dependent on its motion ability. The kicking motion is one of the most important motions in a soccer game. However, automatic, full body motion generation for humanoid robots presents a formidable computational challenge. At the current state the most common approaches of implementing this motion are based on key frame technique. Such solutions are inflexible,...
In this paper, a mixed controller for solving the trajectory tracking and point stabilization problems of a mobile robot is presented, applying the integration of backstepping technique and neural dynamics. By introducing a virtual target point, the whole motion process is divided into two parts. The first one is employed to realize tracking control and the other one is adopted to implement point...
The article proposes a new feedback control model which is suited for path following in a 3 Dimensional Cartesian space. Differently from other methods in literature, the method proposed neither requires to compute a projection of the robot's position on the path, nor it needs considering a moving virtual target. In spite of this: i) it guarantees asymptotic stability for every 3D curve which can...
A tele-operation system for a crane is developed. The crane consists of a small actuator and a large actuator in x and y direction respectively. The large actuators are controlled by input signals from an operator and the small actuators are used as a regulator and feedback controlled by a wire angle sensor. Since a motion of the suspended object can be approximated as a second order system, overshoots...
This paper proposes multivariable robust control for a gait trainer for people with walking disability. The gait trainer composes of linkages and motors, which drive the linkages to produce preferred gait traces. To simplify the traditional motor control, the tracking error and motor current are feedback for control design to regulate the motor voltage. First, the transfer function matrices of the...
This paper proposes a new method for designing a weigh feeder control system. The model of a weigh feeder cannot be obtained accurately because its dynamic characteristics are time varying and its high frequency vibration modes are not easily identified. In this paper, a weigh feeder is assumed to be a first-order plus integrator system, and a control law consists of a constant feed-forward control...
An accurate estimation of both rotor and stator resistances is usually required to achieve high performance control in induction machine drive systems. In this study, an output feedback predictive controller which is adaptive with respect to these parameters uncertainties is proposed. Such design attempts to a fully decoupling in speed and flux magnitude regulation, as soon as an estimation scheme...
This article describes the design of a linear observer-linear controller-based robust output feedback scheme for output reference trajectory tracking tasks in an input delayed omnidirectional mobile robot. The unknown, possibly state-dependent, additive nonlinearity influencing the tracking error dynamics, is modeled as an absolutely uniformly bounded, additive unknown “time-varying disturbance” input...
Neuromuscular Electrical Stimulation (NMES) (also described as functional electrical stimulation (FES) in some scenarios) is a prescribed treatment for various neuromuscular disorders where an electrical stimulus is provided to elicit a muscle contraction. Barriers to the development of NMES controllers exist because the muscle response to an electrical stimulation is nonlinear and the muscle model...
In this contribution, a ℋ∞-controller as derived in is used for the tracking of a sufficiently smooth reference trajectory. The systems under investigation are bilinear SISO power systems with dynamic feedback. Two theorems are presented, when the conditions on time-varying iISS (integral input-to-state stability) and the suboptimality of the feedback control law are fulfilled along the overall error...
This paper considers the problem of controlling both the planar position and the orientation of an underactuated airship with a reduced number of actuators in the presence of a unknown persistent wind disturbance. The airship is a nonholonomic system described by a set of nonlinear equations and the dynamics are subjected to bounded uncertainties. A smooth and time-varying coordinate transformation...
Modern data centers must provide performance assurance for complex system software such as multi-tier web applications. In addition, the power consumption of data centers needs to be minimized to reduce operating costs and avoid system overheating. Various power-efficient performance management strategies have been proposed based on dynamic voltage and frequency scaling (DVFS). Virtualization technologies...
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