[[alternative]]Robot-Assisted Grinding and Polishing of Specimens with Free-Form Surfaces

計畫編號：NSC89-2212-E032-008研究期間：200008~200107研究經費：522,000[[sponsorship]]行政院國家科學委員

Development of a polishing robot system

[[abstract]]This paper presents the development of a robot-assisted surface finishing system with an active force controller. The system utilizes a dexterous manipulator to attain the desired position and orientation in 3D space during finishing processes. This single-axis force controller consists of a DC motor and a software observer. The DC motor is attached to the robot wrist and used to actuate a pneumatic hand-grinder. The force observer is designed to sense the grinding contact-force based on the driving current and output position of the motor. The function of the active force controller includes observing the polishing contact force, applying a desired polishing pressure in the normal direction of the workpiece surface, and adjusting the contact angle between the hand-grinder and the surface of the workpiece. In this research, the prototype of a robot-assisted polishing system is constructed and tested on a Tatung A-530 robot. The experimental results show that the robot-assisted polishing system functions well under a variety of grinding and polishing conditions[[conferencetype]]國際[[conferencedate]]19991018~19991021[[iscallforpapers]]Y[[conferencelocation]]Barcelona, Spai

Path planning for robot-assisted grinding processes

[[abstract]]Path planning for a robot-assisted surface finishing system with an active torque controller is presented. We utilize a dexterous manipulator to attain the desired position and orientation in three-dimensional space during finishing processes. A single-axis active controller consists of a DC motor and a software observer is attached to the robot wrist and used to actuate a pneumatic hand-grinder. The torque observer is designed to sense the grinding contact force based on the driving current and output position of the motor. Zigzag and fractal paths on curved surfaces are designed for the grinding processes. In order to determine an ideal grinding condition, Taguchi's method for experimental design is utilized. We choose four grinding conditions, namely, path pattern, grinding contact pressure, tool diameter, and feed rate. Tendencies of these factors can be found from the experiments. In this research, the prototype of a robot-assisted finishing system is constructed and tested on a Tatung A330 robot. The experimental results show that the robot-assisted finishing system functions well under a variety of grinding conditions.[[conferencetype]]國際[[conferencedate]]20010521~20010526[[conferencelocation]]Seoul, Kore

A robot-assisted finishing system with an active torque controller

[[abstract]]The development of a robot-assisted surface finishing system with an active torque controller is presented in this paper. We utilize a dexterous manipulator to attain the desired position and orientation in three-dimensional space during finishing processes. A single-axis active controller consists of a DC motor and a software observer is attached to the robot wrist and used to actuate a pneumatic hand-grinder The torque observer is designed to sense the grinding contact force based on the driving current and output position of the motor. The function of the active torque controller includes observing the polishing contact force, applying a desired polishing pressure in the normal diffraction of the specimen surface and adjusting the contact angle between the hand-grinder and the surface of the workpiece. In this research, the prototype of a robot-assisted finishing system is constructed and tested on a Tatung A530 robot The experimental results show that the robot-assisted finishing system functions well under a variety of grinding and polishing conditions.[[conferencetype]]國際[[conferencedate]]20000424~20000428[[booktype]]紙本[[conferencelocation]]San Francisco, CA, US

Updated Force Model for Milling Nickel-based Superalloys

Nickel-based superalloys are commonly used in applications which require high strength and resistance to creep and oxidation in extreme conditions. All nickel-based superalloys are considered difficult to machine; however, cast gamma-prime-strengthened nickel-based superalloys are more difficult to machine than common nickel-based superalloys. Machining comprises a significant portion of manufacturing processes and with advancements in technology and material properties, the methods and models used must be adapted in order to keep pace. In this research, correlations are made, using fundamental principles, between measurements made with on-machine touch probes and the cutting tool\u27s wear state, those correlations are used in an adaptive algorithm to estimate the size of the tool wear, and the estimates are used in an updated mechanistic cutting force model to predict the progression of cutting forces in gamma-prime-strengthened Nickel-based superalloys. This work impacts machining operations on advanced and common materials by developing a tool wear estimation method with readily available equipment and a computationally tractable force model. It influences knowledge in the field through the fundamental relationships, robust adaptive approach, and modifications to the mechanistic force model. This research shows that on-machine touch probes are able to measure changes in the geometry of a cutting tool as it wears; however, measurement uncertainty results in 20 micrometers of variation in the wear estimation. The wear estimation was improved through the use of a Kalman filter. The average error from 24 estimations was 8 micrometers. Addressing the geometric changes in the tool due to wear, the mechanistic cutting force model estimated the progression of cutting forces with 30% more accuracy than without addressing the tool changes

Effects of imbalance and geometric error on precision grinding machines

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1997.Includes bibliographical references (p. 109-110).by Jared Evan Bibler.M.S