仿腕关节柔顺并联打磨机器人设计与试验

根据柔性并联机构逆向自适应运动原理,设计了一种3转动输出的3SPS+S仿腕关节柔性并联打磨机构,建立了机构运动方程,得到了柔性支链变形量与动平台姿态的关系;分析了柔性支链的变形力以及打磨工具打磨力、输出力矩情况,并建立力学模型;以打磨工具姿态变化和打磨力恒定为目标,对建立的三维模型进行仿真,并通过样机模拟得到机构的工作参数范围;仿真和试验结果表明,这种打磨机构可根据工件曲面几何形状的改变而实时改变打磨工具姿态,在有效控制力的前提下可保持打磨头和工件间的接触打磨力不变,该机构设计简单、运动灵活、方便控制,具有较好的应用价值。

Design and Experiment of Compliant Parallel Humanoid Wrist Joint Polishing Robot

In the polishing process of free surface, the traditional intelligent control robot has some problems such as complex programming complexity and difficulty in controlling. A humanoid wrist joint compliant parallel mechanism 3SPS+S used in polishing robot was designed according to the principle of inverse adaptive motion of flexible, and its moving platform can output three rotations. Firstly, the inverse motion equation of the mechanism was established to obtain the relation between deformation quantity of the three flexible branched chains and attitude of the moving platform. Secondly, the mechanics model was deduced through analyzing deformation forces of flexible chains, grinding force and output moment of the tool. Furthermore, simulation was executed based on the 3D model for the target of the tool posture change and the constant grinding force, and the ranges of some work parameters were obtained through the prototype test. Lastly, taking a car shell as a grinding object, an experiment was designed to validate whether the grinding tool mounted on the moving platform could fit rapidly to the shell surface when humanoid wrist joint compliant parallel mechanism wholly moved along a given simple track under driving of a 6-DOF manipulator. Both simulation and test results showed that the position and attitude of the tool can be changed rapidly as changing the geometry of the workpiece through using the grinding mechanism, and it can keep the contact force unchanged between the grinding head and the workpiece. Because of several advantages, such as simple design, flexible movement and convenient control, this kind of mechanism previously has good application value.