This paper presents a method for determining the posture of a mobile manipulator aiming to reach a target end-effector pose. A posture is composed of two parameters: the pose of the mobile platform and joint angles of the manipulator. To determine the platform pose rationally, we propose a novel posture evaluation method focusing on the pose error associated with the end-effector and caused by the accumulated positioning error of the platform. The proposed method implies not only using the pose error of the mobile platform but also considering the manipulation ability of the end-effector, as well as the tolerance region for grasping an object by the end-effector. The evaluation results can be used to analyze the stability of postures in terms of grasping a target object. In addition, we introduce a search-based method to identify appropriate poses of the mobile platform. We also consider an application example of a two-link three-joint mobile manipulator. Using such a robot, we explain a concrete calculation method used to estimate the tolerance region, and then, show the simulation results corresponding to posture evaluation and pose determination.

本文提出了一种确定旨在达到目标末端执行器姿势的移动机械手姿势的方法。姿势由两个参数组成：可移动平台的姿势和机械手的关节角度。为了合理地确定平台姿态，我们提出了一种新颖的姿态评估方法，该方法着眼于与末端执行器相关的，由平台的累积定位误差引起的姿态误差。所提出的方法不仅意味着使用移动平台的姿势误差，而且还考虑了末端执行器的操纵能力以及末端执行器抓取物体的公差区域。评估结果可用于根据抓握目标物体来分析姿势的稳定性。此外，我们引入了一种基于搜索的方法来识别移动平台的适当姿势。我们还考虑了两连杆三关节移动机械手的一个应用示例。我们将使用这种机器人说明用于估计公差区域的具体计算方法，然后显示与姿势评估和姿势确定相对应的仿真结果。