This paper focuses on the kinematic properties of a new three-degree-of-freedom hybrid manipulator. This manipulator is obtained by adding in series to a five-bar planar mechanism (similar to the one studied by Bajpai and Roth [1]) a third revolute passing through the line of centers of the two actuated revolute joints of the above linkage (Figures 2 & 3). The resulting architecture is hybrid i...

This paper proposes a way to achieve positioning tasks by 2-D visual servoing when the desired image of the observed object cannot be precisely described. The object is assumed to be planar and motionless, but no knowledge about its shape or pose is required. First, we treat the case of a threadlike object, and then we show how our approach can be generalized to an object with three particular ...

Event-based visual servoing is a recently presented approach that performs the positioning of a robot using visual information only when it is required. From the basis of the classical image-based visual servoing control law, the scheme proposed in this paper can reduce the processing time at each loop iteration in some specific conditions. The proposed control method enters in action when an e...

Nonlinear weather optimal control of ships exposed to environmental disturbances is discussed. Emphasis is placed on weather vaning, that is the ship should be orientated such that the moment in yaw due to mean current, wind and wave forces is zero and at the same time maintain a "xed position and heading. The main problem in doing this is that the environmental forces acting on the ship are im...

In this paper, combined GPS and GLONASS positioning systems are discussed and some solutions have been proposed to improve the accuracy of navigation. Global Satellite Navigation System (GNSS) is able to provide position, velocity and time with respect to coordinated universal time. GNSS positioning is based on received satellite signals, so its performance is highly dependent on the quality of...

This paper develops simple approximate methods to analyze a two-stage stochastic distribution system consisting of one warehouse and multiple retailers. We consider local and central control schemes. The main ideas are based on relaxing and or decomposing the system into more manageable newsvendor type subsystems. We provide bounds on optimal echelon base-stock levels and on the optimal expecte...

Parallel robots are nowadays leaving academic laboratories and are finding their way in an increasingly larger number of application fields such as telescopes, fine positioning devices, fast packaging, machine-tool, medical application. A key issue for such use is optimal design as performances of parallel robots are very sensitive to their dimensioning. Optimal design methodologies have to rel...

This paper presents a globally asymptotically stabilizing (GAS) controller for regulation and dynamic positioning of ships, using only position measurements. It is assumed that these are corrupted with white noise hence a passive observer which reconstructs the rest of the states is applied. The observer produces noise-free estimates of the position, the slowly varying environmental disturbance...

The objective of this paper is to present the methods of development and study of control law of rodless pneumatic actuator with fuzzy regulator in order to improve the accuracy of the pneumatic drive carriage positioning. The basis for improving the accuracy of positioning of the pneumatic actuator is the Intelligent Control System.

We describe a method to achieve robotic positioning tasks by image-based visual servoing when the object being observed has a complex and unknown shape. We first focus on the computation of an analytical expression of the interaction matrix according to a polar description of the image contour of the object. Experimental results are presented to validate the proposed algorithm. In particular, t...