基于参数化运动补偿的地基雷达对月成像技术

地基雷达对月成像可以获得月球表面的电磁散射特性、地形地貌特征等,可用于月球的科学研究。地基雷达对月成像技术是将合成孔径技术应用到天文探测当中,延迟多普勒技术是地基雷达天文成像应用最为广泛的技术,其关键在于运动补偿。目前,国外在地基天文雷达领域的研究上已趋于成熟,而我国正处于起步阶段。为解决地基雷达对月成像中的难点问题,本文首先基于地月运动几何模型分析了延迟多普勒成像理论的关键问题,包括成像原理、分辨率和模糊问题。接着,本文提出了一种参数化运动补偿算法,该算法以图像熵值为评价指标进行参数搜索,并采用布谷鸟搜索算法提升参数搜索效率。最后,通过仿真验证了算法的有效性,为将来开展试验验证提供了技术支撑。

维修Agent模型的双指数映射参数化方法

复杂关节模型的运动参数化是虚拟人动作仿真的基础,传统的旋转矩阵、欧拉角方法和四元数等参数化方法在运动描述方面存在一定缺陷,都不能很好地解决复杂关节模型的运动参数化问题。对指数映射方法进行改进,提出一种双指数映射(DEM)运动参数化方法,用于同时描述关节模型的平移与旋转、线速度与角速度。首先阐述其在运动描述和参数计算方面的能力,然后进行了维修操作训练仿真实验。研究结果表明了该方法在求导和微分、常微分方程求解、优化控制和插值拟合等方面具有较强的描述功能。

基于压缩域行为描述子的视频检索新技术

构造了一个基于压缩域行为描述子的检索模型CMRS。在CMRS中,针对特征提取部分提出了一种基于宏块连接跟踪机制的运动轨迹提取算法和一种参数行为估计算法,并且对参数化运动原始的匹配准则(PSSM)加以改进,构造了新的基于速度的相似匹配准则。最后在检索模型的实现阶段,实现了模型的总体框架。

Mechanism Design and Motion Analysis of Heavy⁃Load Transfer Robot with Parallel Four⁃Bar Mechanism

Heavy-load transfer robots are widely used in automobile production and machinery manufacturing to improve production efficiency.In order to meet the needs of large billet transfer,a 4-DOF transfer robot is designed in this paper,which consists of parallel four-bar mechanisms.The Jacobian matrix referring to the mapping matrix from the joint velocity to the operating space velocity of the transfer robot can be solved by the differential-vector method.The mean value of the Jacobian matrix condition number in the workspace is used as the global performance index of the robot velocity and the optimization goal.The constraint condition is established based on the actual working condition.Then the linkage length optimization is carried out to decrease the length of the linkage and to increase the global performance index of velocity.The total length of robot rods is reduced by 6.12%.The global performance index of velocity is improved by 45.15%.Taking the optimized rod length as the mechanism parameter,the distribution of the motion space of the transfer robot is obtained.Finally,the results show that the proposed method for establishing the Jacobian matrix of the lower-mobility robot and for the optimization of the rods based on the velocity global performance index is accurate and effective.The workspace distribution of the robot meets the design requirements.

Weigh in Motion Based on Parameters Optimization

Dynamic tire forces are the main factor affecting the measurement accuracy of the axle weight of moving vehicle.This paper presents a novel method to reduce the influence of the dynamic tire forces on the weighing accuracy.On the basis of analyzing the characteristic of the dynamic tire forces,the objective optimization equation is constructed.The optimization algorithm is presented to get the optimal estimations of the objective parameters.According to the estimations of the parameters,the dynamic tire forces are separated from the axle weigh signal.The results of simulation and field experiments prove the effectiveness of the proposed method.

Enhancing pose accuracy of space robot by improved differential evolution

Due to the intense vibration durirLg launching and rigorous orbital temperature environment, the kinematic parameters of space robot may be largely deviated from their nominal parameters. The disparity will cause the real pose （including position and orientation） of the end effector not to match the desired one, and further hinder the space robot from performing the scheduled mission. To improve pose accuracy of space robot, a new self-calibration method using the distance measurement provided by a laser-ranger fixed on the end-effector is proposed. A distance-measurement model of the space robot is built according to the distance from the starting point of the laser beam to the intersection point at the declining plane. Based on the model, the cost function about the pose error is derived. The kinematic calibration is transferred to a non-linear system optimization problem, which is solved by the improved differential evolution （DE） algoritlun. A six-degree of freedom （6-DOF） robot is used as a practical simulation example, and the simulation results show： 1） A significant improvement of pose accuracy of space robot can be obtained by distance measurement only; 2） Search efficiency is increased by improved DE; 3） More calibration configurations may make calibration results better.

Mechanism Design of Palletizing Robot Based on Translating Cam Principle

Palletizing robot technology has been applied more and more extensively in logistics automation field.But there are some limitations in the current single-arm palletizing robot that it cannot do effective work in the process of moving back to the taking-end and the mechanical arm has so many freedoms that its control system is relatively complex.Based on the translating cam principle,a novel palletizing robot is designed.The horizontal movement of the palletizing mechanical arm is controlled by changeable outer slides,and the vertical movement is controlled by partitioned up-and-down spindles.To improve palletizing efficiency,the single palletizing mechanical arm is changed into multi-arm.Moreover,to improve its kinematic properties,the acceleration operating performance,joint driving force and palletizing trajectory are optimized through the multi-objective delaminating sequence method.According to the optimization results,the 3D model of the multi-arm palletizing robot is built in Pro/E,and the kinematic simulation is made.The simulation results show that the novel mechanism and optimization parameters are rational and feasible.This novel palletizing robot has the advantages of cam mechanism,so it simplifies the driving mode of palletizing movement and can lower the requirements for controlling system.At the same time,it can increase palletizing efficiency further by adding mechanical arms.

A Comprehensive Evaluation Method of Sports Modernization Based on AHP

In order to improve the modernization level of sports comprehensive evaluation, a comprehensive evaluation method of sports modernization based on analytic hierarchy process （AHP） is proposed. An index analysis model for constructing the comprehensive evaluation of sports modernization is constructed, spatial modeling of information feature distribution is taken based on nonlinear time series analysis method for comprehensive evaluation of sports modernization, control objective function of comprehensive evaluation of sports modernization is constructed by analytic hierarchy process, optimal control parameters is obtained and comprehensive evaluation and optimization of sports modernization are realized. The simulation results show that the method is applied in comprehensive evaluation modem sports, it has performance of high reliability and good accuracy.