Papers by Keyword: Bezier Curve

Abstract: Due to its strategic location and ocean currents, the Sunda Strait has the potential to produce energy that might be used as a source of electricity. As a result, this strait area urgently needs a suitable turbine design. This strait's most significant sea current speed is 1 (one) m/s. The Savonius rotor is one of the rotor kinds of turbines that can operate in the slow sea current—modifying the rotor from semi-circular to use the Bezier curve for the shape to optimize the performance. This paper will discuss the design of the Savonius rotor using the Bezier curve, that have improved performance. The rotor with double stacking will also enhance the performance of the rotor. This design is a novelty for vertical marine current turbine applications in ocean renewable energy.

Abstract: A plane stress yield function which is described by multi-segment spline curve is proposed. This model is able to consider an arbitrary number of multi-axial stress states and its normal directions on the yield surface. Moreover by using interpolation based on cubic spline function, planar anisotropy is also described precisely. To show the applicability of the model, some evaluation of material properties and simulation results of hole expansion test are discussed.

Abstract: In this paper, aerodynamic performance and noise of the wind turbine airfoil are the optimization design goal and based on this, the optimization design method with multi-operating points and multi-objective of the airfoils is built. The Bezier curve is used in parametric modeling of the contour of the airfoil and the general equation for control points is deduced form the discrete points coordinates of the airfoil. The weigh distribution schemes for multi-objective and multi-operating points are integrated designed by treating the NREL S834 airfoil as the initial airfoils. The results show that the lift-to-drag ratio of the optimized airfoils has a improvement around the designed operating angle and the overall noise has a reduction compared with the initial airfoils, which means that the optimized airfoils get a better aerodynamic and acoustic performance.

Abstract: Coordinated motion of two robots in Cartesian space is considered in the paper. The goal is to generate trajectories for which change of distance between points on trajectories during motion is minimal. To minimize relative position errors along trajectories an idea of corrective motion is introduced. Trajectory coordinates are calculated as the sum of programmed and corrective motions. To calculate the speed vector of the programmed motion at the current position, the speed at the closest point on the programmed trajectory is used. The closest point is defined as the one to which the distance from the current position is minimal or the programmed position at given time. In order to attract the generated trajectory to the programmed one a modification of the programmed speed vector is proposed. The described approach is verified in simulation. For simulation experiments programmed trajectories defined by Bezier curve segments are used. Simulations for different shapes of programmed trajectories and different programmed velocity rates are presented.

Abstract: Given two tubes with non-coplanar axes whose sections are circle, we acquire that axes of the tubes can be smoothly blent by Bezier curve. In this situation, the paper proposes a new method to build the blending surface by generalized Bezier tube. Meantime, we obtain smoothly blending parameter surface.

Abstract: The Cutting tool rotation and movement Matrix equation is established in the paper according to the high efficiency of NC machining elliptic cone. Tool path of the elliptic cone is established by the tangent method and Bernstein curve equations. Line contact contour surface method of machining surface is put forward on the basis of tool path. With this method surface interpolation can be carried out according to the equation of curved surface, which can be efficiently processing elliptic cone. Simulation experiments were carried out in this paper, and the results showed that Elliptic cone can be NC machining with high efficiency by the line contact contour surface method.

Abstract: In order to obtain better speed and high accuracy, real-time curve fitting and fitting processing at transition points are often necessary when machining complex contours. Based on the quadratic trigonometric Bézier curve, a new algorithm is presented to realize curve fitting only between transition segments. This method ensures the machining precision and increases the maximum allowable speed at the transition points. Simulation and experiment results show that the transition velocity changes smoothly and steadily as well as the processing efficiency is promoted.

Abstract: Based on previous work, which presented theorems and algorithms for generating a new type of generalized Ball curve (Partial Said-Ball curve), the present study supplements the transformation formula from a Bézier curve to a Partial Said-Ball curve and prove the corresponding theorem. All the results are useful for the application of generalized Ball curves and their popularization in Computer Aided Geometric Design.

Abstract: In this paper, we propose a novel key management scheme based on Bezier curves for hierarchical wireless sensor networks (WSNs). The design of our scheme is motivated by the idea that a Bezier curve can be subdivided into arbitrarily continuous pieces of sub Bezier curves. The subdivided sub Bezier curves are easily organized to a hierarchical architecture that is similar to hierarchical WSNs. The subdivided Bezier curves are unique and independent from each other so that it is suitable to assign each node in the WSN with a sub Bezier curve. Since a piece of Bezier curve can be presented by its control points, in the proposed key management scheme, the secret keys for each node are selected from the corresponding Bezier curve’s control points. Comparing with existing key management schemes, the proposed scheme is more suitable for distributing secret keys for hierarchical WSNs and more efficient in terms of computational and storage cost.

Abstract: In view of the characteristics of threaded binary tree and visualization of the problem,,it is realized the visualization of binary tree by using object-oriented method and the features of complete binary tree, and then achieved the visualization of threaded binary tree by using the COM component technology and the Bezier curve. This makes the tree related operations more intuitive, nice interactive performance, real-time.