Papers by Keyword: Trajectory

Abstract: In this paper, a novel model, HDP-HMM-SCFG is proposed for representing and classifying activities based on motion trajectories. In the model, activities are represented by stochastic grammar using trajectory, where trajectory segments are considered as observations emitted by the grammar terminals attached with HMMs. Then, by replacing the Euclidian distance in the kernel function of Gaussian radial radix with EMD-DTW, which is proposed to measure the distance between two trajectories by integrating the pros. of both EMD and DTW, multi-class SVM classifier is constructed. Experiments on ASL dataset are carried on to validate our approach.

Abstract: The paper presents a reverse kinematic analysis for the free through to basket in order to determine the possible angular movement speed of the arm segments during throw flexion. The body segments offering three freedom degrees to the kinematic model are: the arm, the forearm and the hand. From geometric conditions regarding to the possibility of the ball to get through the basket and the analysis of the parabolic trajectory of the ball, one could determine the mathematical relations for the limitative values of the horizontal and vertical components of the initial velocity and consequently, for the calculation of the initial angle of throwing the ball. On the other hand, from the expression of the flexion movement of the considered body segments, it could be possible to obtain the calculation of the initial throw velocity as functions of the anthropometric data of the analyzed subject, of flexion angles and angular velocity of movement of the body segments. Using some models of functional mathematic analysis, from the two equations with three unknowns, one could determine the variation field of the system solutions. By setting the conditions related to the numeric limits of variation for the angular speed, the numeric field of the possible solutions for the equation system is straitened.

Abstract: The paper deals with the kinematical approach of the trajectory of movement of an academic rowing skiff with a view to determine a given racing speed of the boat. It uses inverse kinematics since this method allows obtaining analytical calculus formulas for the movement of paddles in their two moments of motion: active and passive strokes. Movement of the paddles while following an arc-shaped trajectory outlining a sphere-like quadrilateral requires different values of amplitude of angular displacement of the paddles according both to anthropometrical values of the athlete and to his physical and technical training. The numerical application is made for several values of these angles which define the arcs of the circle for active and passive curves and for the moments between the two strokes (angle of the paddle while slicing in and out the water). These amplitudes of angular displacement are being considered, from the point of view of the horizontal component, equal to the speed of the skiff while imposing the linear speed of the paddle, and they would help determining movement frequencies of the paddle while following the sphere-like quadrilateral trajectory.

Abstract: An experimental test bench is proposed in order to analyze the trajectory shape described by the termination of the Jansen’s type of leg mechanism during a walking sequence. A prototype of a walking robot based upon Jansen walking mechanism is constructed for this purpose. A marker is placed at the end of the leg and a CCD camera recorded the trajectory shape described by the leg driven by a DC motor through a crank. The results are interpreted with the help of a program based on image processing created for determining the length and the height of the step during walking after studying the trajectory.

Abstract: The reliability of formwork support is directly related to gob-side entry retaining success. In this paper a dual function of supporting and filling formwork support is designed. Use SolidWorks software build 3D modeling and virtual assembly, The establishment of a movement model of the anti-four-bar linkage formwork template using numerical methods and get the motion trajectory of the roof. It has been verify that the anti-four bar linkage design of the hydraulic support is feasible.

Abstract: ANSYS-LS/DYNA 3D finite element software projectile penetrating concrete target three-dimensional numerical simulation , has been the target characteristics and destroy ballistic missile trajectory , velocity and acceleration and analyze penetration and the time between relationship , compared with the test results , the phenomenon is consistent with the simulation results. The results show that : the destruction process finite element software can better demonstrate concrete tests revealed the phenomenon can not be observed , estimated penetration depth and direction of the oblique penetration missile deflection .

Abstract: In this paper is presented a comparative study between using extended Kalman filter and particle filter applied on SLAM algorithm for an autonomous mobile robot. The robot navigates through an unknown indoor environment in which are placed 80 landmarks and it creates the map of the environment. Because the sensors placed on the robots produce measurement errors it is necessary to use Bayesian filters as the Kalman filter or the particle filter. An application was implemented that shows the estimated measurement errors produced while using both filters in order to create the estimated map of the closed environment in which the autonomous mobile robot is navigating.

Abstract: Frequent start and stop in complex unstable environment causes micromouse based on single MCU cannot work properly, especially in fast speed; A new micromouse based on LM629 is explained and demonstrated how to design, especially for its motion control firmware. Experiment results show that the micromouse prototype based on LM629 can be very good to meet the fast micromouse requirements.

Abstract: The millimeter-wave terminal guidance ammunition monitoring scanning field is small. The modified design is in order to improve the search section trajectory guidance. This study established seeker search area to capture the target model, which leads to the missile engine unpowered glide distance formula after flameout. At the millimeter-wave terminal on the missiles contraction section ballistic. Each missile is designed for the flat road, the swash decline ballistic programs. Flat missile road program scans and does not shrink. Its flight speed falls and declines rapidly, has different gliding distance and terminal velocity. After the missile engine is flameout, its start-gliding speed is great. Ramp fell ballistic program enhances the air-air (or air-ground) guided missile’s gliding ability, helping to improve range. But shortcomings are that target tracking scanning domain contracts. Using the seeker optical axis in the pitch direction can achieve accurate positioning with the height precession. Two ballistic designs can both meet the target seeker’s scanning, thus effectively improve the striking precision.

Abstract: A mathematical model of air vehicle gliding trajectory was established and attack angle was regarded as control variable. Adaptive simulated annealing algorithm was adopted to optimize the 101 nodes of attack angle. By optimizing the control law of attack angle of gliding trajectory, the maximum range of air vehicle is increased significantly, which increases 107%.