Severe deformations and vibration usually occur when grinding the weak-stiffness workpieces, then fluctuate the grinding force and damage the surface. In this paper, the time-varying isobaric surface (TVIS) is defined as a virtual surface to generate constant force during robotic grinding. Based on it, a novel robotic grinding method, including contact trial and surface reconstruction, is proposed. In the contact trial process, the robot actively samples the deformation and stiffness of contact point with a force sensor. Then, a TVIS mesh is constructed to replace the original geometry of the workpiece, which is utilized for grinding path planning. Experiments have been conducted to verify the feasibility of this method. The result shows that the proposed method can achieve constant grinding force and is robust to the types of workpieces and the processing techniques. Furthermore, it is considered as an intelligent method for customized robotic machining of the weak-stiffness workpieces.

磨削低刚度的工件时通常会发生严重的变形和振动，然后使磨削力产生波动并损坏表面。本文将时变等压面（TVIS）定义为在机械手磨削时产生恒定力的虚拟表面。在此基础上，提出了一种新的机器人磨削方法，包括接触试验和表面重构。在接触试验过程中，机器人通过力传感器主动采样接触点的变形和刚度。然后，构造一个TVIS网格以替换工件的原始几何形状，该网格用于规划磨削路径。已经进行了实验以验证该方法的可行性。结果表明，该方法可以达到恒定的磨削力，对工件类型和加工工艺具有鲁棒性。此外，它被认为是针对弱刚度工件进行自动机械加工的一种智能方法。