Finding the current pose of the end-effector of a parallel robot is a problem, since its forward geometric model generally has several solutions. Current methods to address this problem operate mainly under the assumption that the robot never changes its assembly mode nor gets close to Type 2 singularities. Nonetheless, recent works proved that a parallel robot can change its assembly mode, thanks to dedicated trajectory generation and control. Such a feature allows increasing the operational workspace of such manipulators. Hence, correctly tracking the end-effector pose while crossing Type 2 singularities is mandatory for a practical usage of this workspace enhancement method. However, on Type 2 singularities, several solutions of the forward geometric model merge, making current tracking methods ineffective. To fill this gap, we propose a two-step pose tracking methodology. First, a differential inclusion based on kinematics and dynamics is solved. Second, joint measurements are used to tighten resulting enclosures. The effectiveness of this method is discussed, thanks to experimental data gathered on a planar parallel robot.

中文翻译：

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基于动力学的并联机器人可靠装配模式跟踪算法

寻找并联机器人末端执行器的当前位姿是一个问题，因为其正向几何模型通常有几种解决方案。当前解决这个问题的方法主要是在机器人永远不会改变其装配模式也不会接近类型 2 奇点的假设下运行的。尽管如此，最近的工作证明，由于专用的轨迹生成和控制，并联机器人可以改变其组装模式。这种特征允许增加这种操纵器的操作工作空间。因此，在穿越类型 2 奇点时正确跟踪末端执行器姿势对于这种工作空间增强方法的实际使用是必不可少的。然而，在类型 2 奇点上，前向几何模型的几个解合并，使得当前的跟踪方法无效。为了填补这个空白，我们提出了一种两步姿势跟踪方法。首先，求解基于运动学和动力学的微分包含。其次，联合测量用于收紧产生的外壳。由于在平面并联机器人上收集的实验数据，讨论了该方法的有效性。