Pose estimation and machining efficiency of an endoscopic grinding tool

In this research, a method was developed for estimating the amount of material removed in an endoscopic grinding process. A model was formulated for the estimation of the pose (position and orientation) and force on a modified PENTAX ES-3801 endoscope, based on geometric analysis of the endoscope bending section and input from an LVDT position sensor and load cell placed in line with the driving cable of the endoscope. The experimental and theoretical results showed that the pose and force of the flexible bending section can be predicted and monitored when subjected to varying machining loads. In most conditions, the estimated force, position, and orientation error were less than 0.5 N, 2.0 mm, and 3.0°, respectively. For estimation of material removal in grinding, the effective energy spent on removing material, energy wasted by chatter, and energy wasted by the transmission shaft had to be calculated. Grinding experiments were carried out on aluminum workpiece, and the amount of material removal was estimated and measured for comparison. The results suggested that it is possible to estimate the amount of material removed by a non-rigid machine tool with the method described.