中国机械工程

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精确直线可展机构及其动力学分析

畅博彦1,2;李文启1;金国光1,2;宋艳艳1   

  1. 1.天津工业大学机械工程学院,天津,300387
    2.天津工业大学天津市现代机电装备技术重点实验室,天津,300387
  • 出版日期:2018-06-10 发布日期:2018-06-08
  • 基金资助:
    国家自然科学基金资助项目(51275352,51475330);
    天津市自然科学基金资助项目(17JCQNJC04300,17JCQNJC03900)
    National Natural Science Foundation of China (No. 51275352,51475330)
    Natural Science Foundation of Tianjin (No. 17JCQNJC04300,17JCQNJC03900)

Accurate Straight-line Deployable Mechanism and Its Dynamics Analysis

CHANG Boyan1,2;LI Wenqi1;JIN Guoguang1,2;SONG Yanyan1   

  1. 1.Department of Mechanical Engineering, Tianjin Polytechnic University, Tianjin,300387
    2.Tianjin Key Laboratory of Advanced Mechatronics Equipment Technology, Tianjin Polytechnic University, Tianjin,300387
  • Online:2018-06-10 Published:2018-06-08
  • Supported by:
    National Natural Science Foundation of China (No. 51275352,51475330)
    Natural Science Foundation of Tianjin (No. 17JCQNJC04300,17JCQNJC03900)

摘要: 将Hart直线机构和剪叉机构相结合,提出一种仅含转动副的直线可展单元,并设计得到一种精确直线可展机构。根据机构结构学分析理论,阐述可展机构的模块化组成原理,将机构的组成分解为底部模块、中部模块和顶部模块,3种模块均由直线可展单元构成;对单个直线可展单元进行运动学建模,结合机构的模块化组成原理,推导得到任意模块间的运动学递推关系,求解得到多层模块条件下机构的整体运动学模型,运用Lagrange方程构建机构的整体动力学模型;以3层可展机构为例,对其进行动力学数值计算和虚拟仿真,验证所建运动学和动力学模型的正确性和有效性。通过给定末端执行器的输出运动规律,求解得到机构所需的驱动力矩,结果表明:末端执行器为正弦加速度曲线时,机构在整个工作周期内无冲击,运动稳定性好。

关键词: 直线机构, 可展机构, 动力学建模, 驱动力矩

Abstract: Combining Hart straight-line mechanism with scissors mechanism, a new type straight-line deployable unit was proposed which consisted of revolute joint only.Then an accurate straight-line deployable mechanism was designed.According to the mechanism and machine theory, modular principles of the deployable mechanism were explained and the mechanism was composed with three kinds of modules including bottom module,middle module and top module.These modules were all composed by the straight-line deployable units.The kinematics model of a single straight-line deployable unit was established.Combining the modular principles of the mechanism, the recurrent relations of any module kinematics were derived which might be used to solve the whole kinematics model of the accurate straight-line deployable mechanisms consisted of multi-layer modules.The whole dynamics model of the mechanism was presented by Lagrange method based on the whole kinematics model.Taking mechanism consisted of three-layer modules as an example, the dynamics numerical calculation and virtual simulation were carried out, and the correctness and effectiveness of the kinematics and dynamics equations were verified.On the basis of geometric and physical parameters of real mechanism, required driving torque may be obtained when the motion of end-effector was given.The results show that there is no impacts during the whole working cycles by setting sine acceleration movement for end-effectors.

Key words: straight-line mechanism, deployable mechanism, dynamics modeling, driving torque

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