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In this article, an internal and an external synchronization have been investigated, in the presence of uncertain parameters. The proposed controller is designed to synchronize the movement of robot group following the same desired trajectory. To this effect, using a consensus algorithm, we provide an adaptive control under two different schemes. In the mutual synchronization topology, robots network...
The ubiquity of PID controllers in the industry has remained mysterious until now. We provide here a mathematical explanation of this strange phenomenon by comparing their sampling with the the one of “intelligent” PID controllers, which were recently introduced. Some computer simulations nevertheless confirm the superiority of the new intelligent feedback design.
The notion of strong observability is generalized for nonlinear systems. It allows to write the state of the system as a function of the measurable outputs and their time derivatives only, therefore allowing the construction of an unknown-input observer once such derivatives are estimated. It is shown that the output based control design problem for robust finite-time state stability for nonlinear...
In this paper, a novel concept of model based fault tolerance control (FTC) is presented. The FTC is achieved by 2-DOF control strategy: feedback control and feed forward control. Robustness issues are handled by the optimal feedback control and the time varying fault behavior by feed forward path. Firstly, a fault diagnosis scheme is presented for detecting and estimating the fault behavior from...
When robots leave industrial settings, they have to be designed allowing intuitive communication with the humans they interact with. The current paper focuses on collaboration in kinesthetic tasks. Herein, we investigate decision situations. This way, the need of communication between partners can be addressed. The current paper introduces for the first time an experimental paradigm which allows studying...
Typical industrial assembly tasks require an accuracy that cannot be realized by only feedback control if a minimum speed is given by a conveyor. Feed-forward has proven to be advantageous, using predictions of the desired trajectory which will be computed from sensor values. These predictions are improved by a model based classification of the sensor data to typical scenarios. In contrast to linear...
This paper presents motion control concepts on parallel robots with explicit focus on anti-windup-design and trajectory-tracking. Starting from modeling and exact feedback linearization, a cascade control is designed. Improvements to control laws with respect to input-saturations are derived by using concepts of anti-windup compensation. A multiple-axis anti-windup-control is presented, guaranteeing...
This paper presents the manipulator with the new joint which can passively switch free state to drive state and vice versa. The manipulator with the free-state joint is categorized as a system subjected to a nonholonomic constraint; hence, its smooth feedback control cannot be implemented. In this paper, the issues on its control are clarified through the test with the experimental setup of the manipulator...
This paper discusses how mobile manipulators with an under-actuated vertical arm can be designed to be differentially flat. The property of differential flatness is achieved by appropriate inertia redistribution of the vertical arm and a wide range of under-actuation becomes possible. As a result of having the flatness property, the under-actuated mobile manipulators are capable of executing point-to-point...
A simple, under-actuated robotic winch, called the “Winch-Bot,” is developed for surface inspection of a large object. The Winch-Bot, placed over an object surface, has only one actuator for tracing a free geometric path in a vertical plane. The cable length is controlled in relation to the direction of the cable so that the inspection end-effecter hanging at the tip of the cable can follow the path...
We present a novel approach to legged locomotion over rough terrain that is thoroughly rooted in optimization. This approach relies on a hierarchy of fast, anytime algorithms to plan a set of footholds, along with the dynamic body motions required to execute them. Components within the planning framework coordinate to exchange plans, cost-to-go estimates, and “certificates” that ensure the output...
This paper brings forward two kinds of PD control schemes of adaptive neural-variable structure for uncertain robot trajectory tracking. The first scheme consists of a PD feedback and a dynamic compensator which is composed of RBF neural network and variable structure. The adaptive laws of Network weights are based on Lyapunov function method. This controller can guarantee stability of closed-loop...
This paper is concerned with the design of robust active queue management (AQM) controllers for a class of TCP networks. In TCP/IP networks, the packet-dropping probability function is limited between 0 and 1. Therefore, a TCP network with AQM controller was modeled as a rate-based non-linear system with a saturated input. The nonlinear output feedback AQM controller is proposed for achieving the...
This paper proposes a novel feedrate interpolation strategy depending on the error feedback information. The proposed strategy incorporates the real-time non-uniform rational B-spline (NURBS) algorithm and is applied in a biaxial contouring stage system. The objective of the strategy is to improve the contouring accuracy to cope with the high-precision standard nowadays. The proposed method does achieve...
This paper addresses the problem of robust takeoff and landing control of a quadrotor UAV (Unmanned Aerial Vehicle). During the critical flight phases of takeoff and landing the vehicle dynamics change according to the possible existence of contact with the ground. To model the vehicle during the overall maneuver a hybrid automaton is used where each state corresponds to a different dynamic behavior...
This paper discusses the development of guidance scheme for multiple missiles co-operation engagement. Firstly, based on the intercept point, the mid-course guidance out of the aerosphere is studied to obtain the shutdown condition. Secondly, using the the linearization of the control model and error feedback loop in the mid-course guidance out of the aerosphere, a new guidance law called ITCG (Impact-Time-Control...
To improve the switching property of the vacuum circuit breaker, a scheme of position feedback control for permanent magnetic actuator vacuum circuit breaker is presented based on fuzzy control. An adaptive fuzzy controller is designed. With Matlab fuzzy and simulink software package, a model is built to simulate the control scheme. The result indicates that the permanent magnetic actuator can keep...
The model of the juggler is a mechanical machinery designed and constructed to demonstrate and teach control of fast and highly effective servo drives that are commonly used in various motion control applications in industry. The aim of this project is to create a control system able to juggle with three billiard balls, close a visual feedback to recognise actual position of individual balls and present...
Ball-screw-driven mechanism has been used in many industrial applications. In microscopic displacement range, resonant modes, dead time in addition to nonlinear friction of this mechanism deteriorate the positioning performance. To obtain high precision response in this displacement range, a control scheme was proposed as a composition of two types of control methodology: a feedforward compensator...
The problems of trajectory tracking control of space rigid flexible manipulator are discussed in this paper. The equation of nonlinear dynamic of two-link rigid flexible manipulator is established. By using the nonlinear decoupling feedback control method based on the model, the variables of joint angle and elastic deformation are partly decoupled. By use of the inverse dynamic method of manipulator,...
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