A 3-SPS/S parallel rehabilitation mechanism is proposed for the present situation of ankle rehabilitation institutions and the constitution of mechanism is introduced.The degree of freedom is calculated and the position inverse solution equation is established.Combined with numerical examples,the solution of the inverse equation is solved by MATLAB and the simulation results are verified by ADAMS.The simulation results show that the robot can meet the needs of ankle joint rehabilitation by changing the branching movement input.

以一种新型2T2R大摆角(3-RPR+R)&UPS混联机构构型为基础进行研究,介绍机构组成.通过螺旋理论推导了机构的自由度,且通过G-K公式验证了所得自由度.利用空间坐标变换法建立位置逆解方程,用MATLAB求解方程,计算出并联机构的位置逆解.将建好的三维模型导入ADAMS中添加运动副、 添加点运动激励使其实现假定的运动形式,并进行运动仿真.结果表明可实现给定运动,验证了该混联机构的合理性.

For the problem of drilling force and torque measurement in drilling process and defects of BP neural networks itself,the chaotic neural network is used to predict drilling force and torque. The chaotic ge-netic algorithm is used to optimize the initial weights and thresholds of BP neural networks in this article. The chaotic variable is added to the genetic algorithm to improve the global search ability and convergence speed of the genetic algorithm. The optimal solution obtained by the chaotic genetic algorithm is used as the initial weight and threshold of the BP network algorithm. Taking BTA drilling as an example,several groups of axial forces and torques are obtained through experiments under different bit diameters, speeds and feed rates. The optimized BP neural network prediction model is established by using MATLAB, and the axial force and torque are predicted and analyzed. The prediction results are compared with those obtained by the traditional BP neural network. The results show that optimized BP neural network can overcome the defects existing in traditional BP network such as slow convergence rate and easy to fall into local minimum,require more accurate prediction results,and provides a new idea for online prediction of drilling force and torque.

通过给定不同的钻头直径,转速和进给量,进行多次BTA钻削实验,获得了不同切削参数下钻削加工轴向力和扭矩.根据实验所得数据,利用MATLAB建立了BP神经网络预测模型,通过输入切削参数可以预测到轴向力和扭矩.将预测结果与实验测量结果对比表明,所建立的网络模型能够很好的学习输入和输出之间的关系,有效预测BTA钻削时的轴向力和扭矩,为其钻削性能的研究提供一定的依据和指导意义.

A six degree of freedom 4-PRP + 3-UPS&PU redundant hybrid machine tool is proposed,and the statics and static stiffness of the machine tool is studied.Firstly,based on the force Jacobi matrix,the static equilibrium equation is presented,and the mapping matrix between the external load and the driving force and the binding force of the branch is solved.Secondly,the binding screw provided by each drive branch and constraint branch is analyzed,the elastic deformation of each rod under the action of the constraint screw is calculated.Finally,the stiffness model of the mechanism is established,and the elastic deformation of each branch is superposed,and then the overall flexibility and stiffness matrix of the mechanism are obtained.Combined with numerical examples,the MATLAB software is used to calculate the curves of the elastic deformation of each driving and moving platform with the length of the drive rod.

In this paper,the model of the drill pipe-workpiece in deep hole machining is analyzed.The mathematical model of the drill pipe-workpiece is established and solved based on the effect of high pressure cutting oil on the whirling motion of drill pipe and dynamic pressure lubrication.An experiment is designed to measure the lateral displacement of the drill pipe by the electric eddy current displacement sensor,then the diagram of drill pipe center track and lateral displacement are drawn by MATLAB.By comparing the calculated values with the measured values of the system frequency model,the accuracy of the mathematical model is verified which is of practical significance to the study of the vortex control of the drill pipe system.