Method of applying a material to a rotating object by using a robot

Abstract

Material is uniformly applied to the entire outer peripheral surface of a rotating object by using a robot. The material is discharged toward the rotating object from a nozzle (2) of a material discharging device mounted on the distal end of a robot arm, with the nozzle moved along the outer peripheral surface of the object, e.g., a truncated cone (1), rotating at a predetermined speed. A robot control device periodically calculates coordinates (x, R, 0) in a work coordinate system (P5-XwYwZw), including a target moving position (x) of the nozzle in the direction of the rotation axis and a corresponding target nozzle moving position (R) in the radial direction which are individually expressed as a function of the time elapsed after the start of the material applying process (S12). These coordinates are converted to a robot-base coordinate system (OB-XBYBZB) (S14) and converts the result to data for respective robot axes (S15). Then, a pulse distribution is executed in accordance with moving amounts for the respective robot axes in the present cycle which are calculated based on the above data and data obtained in the preceding cycle (S16-S18). As a result, the nozzle mounted on the robot arm is moved at a speed corresponding to the outer diameter of the rotating object which varies along its rotation axis, to uniformly apply the material to the entire outer peripheral surface of the rotating object to the target thickness.