Tool Posture and Polishing Force Control on Unknown 3-Dimensional Curved Surface

Abstract

In the painting process in automotive manufacturing, the repair polishing process is still done manually by a worker with a sufficient skilled technique. However, the number of skilled workers is decreasing with the aging. In addition, the polishing time and the surface quality after the repair polishing are dependent on the proficiency level of the worker. Thus, skill-independent automation technology for the repair polishing is required. In our past research, the serial-parallel mechanism polishing machine was developed for automating the polishing process. The developed machine can control the tool trajectory, tool posture and polishing force simultaneously. In addition, the polishing force is controlled without external sensors by the reaction force observer system. This study aims to develop a polishing automation method for unknown 3-dimensional curved surface by using the developed machine. First, the tool posture control method on unknown curved surface was proposed. Second, the normal force control method based on the posture information was proposed. By using these proposed methods simultaneously, the tool posture and polishing force were controlled in the normal direction on unknown 3-dimesional curved surface. From the experimental results, the validity of the proposed method was verified.

Ageing workforce management in manufacturing systems: state of the art and future research agenda

“…Noh et al (2016) and Borzelli, Pastorelli, and Gastaldi (2017) recommended wearable exoskeletons, for the back and for the arms, respectively, that are able to amplify the worker's input force or torque. Oba and Kakinuma (2016) and Asaga, Yamato, and Kakinuma (2017) studied manual tasks in automotive manufacturing (i.e. repair polishing and buffing processes) and suggested developing a skill-independent automation technology that is able to support and, in some cases, replace the worker.…”

Path Planning under Force Control in Robotic Polishing of the Complex Curved Surfaces

“…Similarly, the top face group is further sorted into the X-axis and Y-axis categories. Later, the part surfaces in the X-axis group are linked based on minimum Euclidian distance d(p, q) as express in Equation (10). The same action is performed on the other two sorted groups.…”

“…Similarly, the different force control methods and process control techniques have been used for better-controlled interaction during the polishing [10][11][12]. A fuzzy vector method was suggested for the grinding and polishing, which enables the controller to deal with force sensor signals caused by the working tool, to search the direction of the constraint surface of an unknown object [10]. Another study concentrated on the control issues that arise during the automation of die and mold surface polishing using an arm robot, particularly on the force controllers to maintain the required tool and workpiece interaction [12].…”

Optimization of the Polishing Efficiency and Torque by Using Taguchi Method and ANOVA in Robotic Polishing

“…Besides optimal parameter achievement, several other methods have been used to improve the automated polishing process. Such methods include improvising of the tool path planning [21][22][23][24], controlled interaction between tool and surface [25][26][27], and the design of new polishing tools for specific or general type workpieces [28][29][30]. However, the optimization of parameters remains a very useful technique that can be implemented together with all these above-mentioned techniques to improve the automated polishing process [2].…”