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Abstract: Faced with methods of data acquisition based on systems for external measurement of the pose of a robot, the use of on-board measurement systems and restrictions based on gauge objects or geometric primitives simplifies and reduces robot calibration costs. Because these are inertial measurement systems, it is necessary to accurately establish the relationship between the reference frame of the sensor and the robot's global reference frame to be able to use the acquired data later to identify kinematic parameters. This paper presents a technique for aligning the reference frames of measurement sensors mounted on the hand of a robot during the acquisition of nominal and actual data for calibration. This technique permits obtaining data from a gauge object with known geometry in the global reference frame of the robot while retaining the accuracy of the measurement system. It is easily generalized to any contact or non-contact measuring system mounted on a robot and can be used also with external high-range measurement systems based on the capture of points of a moving reflector. It also can be used in measurement systems with on-board sensors, using the robot as a positioning element. [Copyright &y& Elsevier]

This article discusses different non contact 3D measuring strategies and presents a model for measuring complex geometry parts, manipulated through a robot arm, using a novel vision system consisting of a laser triangulation sensor and a motorized linear stage. First, the geometric model incorporating an automatic simple module for long term stability improvement will be outlined in the article. The new method used in the automatic module allows the sensor set up, including the motorized linear stage, for the scanning avoiding external measurement devices. In the measurement model the robot is just a positioning of parts with high repeatability. Its position and orientation data are not used for the measurement and therefore it is not directly "coupled" as an active component in the model. The function of the robot is to present the various surfaces of the workpiece along the measurement range of the vision system, which is responsible for the measurement. Thus, the whole system is not affected by the robot own errors following a trajectory, except those due to the lack of static repeatability. For the indirect link between the vision system and the robot, the original model developed needs only one first piece measuring as a "zero" or master piece, known by its accurate measurement using, for example, a Coordinate Measurement Machine. The strategy proposed presents a different approach to traditional laser triangulation systems on board the robot in order to improve the measurement accuracy, and several important cues for self-recalibration are explored using only a master piece. Experimental results are also presented to demonstrate the technique and the final 3D measurement accuracy. [ABSTRACT FROM AUTHOR]

Due to accuracy requirements, robots and machine-tools need to be periodically verified and calibrated through associated verification systems that sometimes use extensible guidance systems. This work presents the development of a reference artefact to evaluate the performance characteristics of different extensible precision guidance systems applicable to robot and machine tool verification. To this end, we present the design, modeling, manufacture and experimental validation of a reference artefact to evaluate the behavior of these extensible guidance systems. The system should be compatible with customized designed guides, as well as with commercial and existing telescopic guidance systems. Different design proposals are evaluated with finite element analysis, and two final prototypes are experimentally tested assuring that the design performs the expected function. An estimation of the uncertainty of the reference artefact is evaluated with a Monte Carlo simulation. [ABSTRACT FROM AUTHOR]