A reflected laser line approach for industrial robot calibration

Abstract

This paper proposes a novel calibration approach for industrial robots. Unlike previous methods, the proposed approach introduces a completely new technique for automatically calibrating robots. The proposed system consists of an industrial robot manipulator, a laser fixture attached to the robot tool center point (TCP), a PC-based interface, and a new portable position sensitive device. This portable device comprised of two fixed position sensitive detectors (PSD's) tilted in an angle to reflect the laser line from one PSD to another. The new calibration approach is not only able to compute the joint offset parameters of the robot, but is also capable of simultaneously calibrating the robot's workpiece relationship. It was also designed to be faster yet simpler than other methods. Throughout this paper we present, analyze and compare both simulations and experimental results between the new proposed approach and our existing methods.

Robot control system for multi-position alignment used to automate an industrial robot calibration approach

“…Let R and t be the rotation matrix and the translation vector of B T D , respectively. Then following the detailed derivations found in our previous paper [13], we have;…”

“…Our proposed calibration system approach [13] requires a laser beam to shoot into one PSD in a way that the reflection hits the other PSD. The idea behind this is to be able to find a unique line based on these two points (found accurately).…”

“…At this stage, we are looking to use the robot's encoder information after the controller stage is successfully done, to be able to accurately determine the real TCP position. Nieves et al [13] introduces the algorithm derivations in more detail. There are two main and separate ways to calibrate an industrial robot, both equally useful in the calibration task, i.e.…”

The stability of dual-PSD based calibration system without its relative location to 3D forming of carbon fiber

“…The high precision automatic calibration system is a hot research topic to improve the precision of 3D forming robot localization. Dual-PSD based robot calibration system has been proposed in reference [1]. Due to that the position of the dual-PSD in the robot's task space is unknown, the study on the stability of the unknown system is the primary problem of the calibration method.…”

“…is the distance from 1 o to the insection of PSD1 plane and PSD2 plane 1. l is the incident line of the PSD1 plane and the intersection of 1 l and PSD1 plane is defined as 1 p , represent the reflected line of the PSD1 plane and the PSD2 plane respectively.…”