Real-time monitoring and control system of an industrial robot with 6 degrees of freedom for grinding and polishing of aspherical mirror
Aspherical mirrors have higher performance and lighter weight than spherical mirrors. However, it is not easy to process, measure, and evaluate their shapes. In particular, large aperture aspherical mirrors used in satellites require high precision and take a long time to process. The conventional process is machined using a computer numerical control with a gantry structure. However, there is a disadvantage that it is difficult to process complex shapes due to lack of degrees of freedom. In order to overcome these problems, we developed a shape processing system using an industrial robot with 6 degrees of freedom. The system consists of toolpath generation program, real-time robot monitoring, and control program. We have verified the performance of the developed system through simulation software provided by the robot manufacturer as well as actual robot operation.
Development of Grinding and Polishing Technology for Stainless Steel With a Robot Manipulator
In traditional industries, manual grinding and polishing technologies are still used predominantly. However, these procedures have the following limitations: excessive processing time, labor consumption, and product quality not guaranteed. To address the aforementioned limitations, this study utilizes the good adaptability of a robotic arm to develop a tool-holding grinding and polishing system with force control mechanisms. Specifically, off-the-shelf handheld grinder is selected and attached to the robotic arm by considering the size, weight, and processing cost of the stainless steel parts. In addition, for contact machining, the robotic arm is equipped with a force/torque sensor to ensure that the system is active compliant. According to the experimental results, the developed system can reduce the surface roughness of 304 stainless steel to 0.47 µm for flat surface and 0.76 µm for circular surface. Moreover, the processing trajectory is programmed in the CAD/CAM software simulation environment, which can lead to good results in collision detection and arm posture establishment.
Finite Difference Modeling on the Temperature Field of Substrate in Friction Surfacing
Friction surfacing is an advanced process of great potential, especially in the field of repair and reclamation of worn and damaged components. As a kind of thermal processing technology, the temperature profile and changes of the substrate in friction surfacing are important factors to get coatings of high quality. In this paper, the temperature field of the substrate during the process is simulated by finite difference method. The results are consistent with experiments, reappearing the temperature change of the substrate during friction surfacing, allowing further study on figuration and quality of coatings.