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External metrology systems are increasingly being integrated with traditional industrial articulated robots, especially in the aerospace industries, to improve their absolute accuracy for precision operations such as drilling, machining, and jigless assembly. While currently most of the metrology assisted robotics control systems are limited in their position update rate, such that the robot has to be stopped in order to receive a metrology coordinate update, some recent efforts are addressed toward controlling robots using real-time metrology data. The indoor GPS is one of the metrology systems that may be used to provide real-time 6DOF data to a robot controller. Even if there is a noteworthy literature dealing with the evaluation of iGPS performance, there is, however, a lack of literature on how well the iGPS performs under dynamic conditions. This paper presents an experimental evaluation of the dynamic measurement performance of the iGPS, tracking the trajectories of an industrial robot. The same experiment is also repeated using a laser tracker for reference. Beside the experiments results presented, this paper also proposes a novel method for dynamic repeatability comparisons of tracking instruments.

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This paper shows how the angular uncertainties can be determined for a rotary-laser automatic theodolite of the type used in (indoor-GPS) iGPS networks. Initially, the fundamental physics of the rotating head device is used to propagate uncertainties using Monte Carlo simulation. This theoretical element of the study shows how the angular uncertainty is affected by internal parameters, the actual values of which are estimated. Experiments are then carried out to determine the actual uncertainty in the azimuth angle. Results are presented that show that uncertainty decreases with sampling duration. Other significant findings are that uncertainty is relatively constant throughout the working volume and that the uncertainty value is not dependent on the size of the reference angle.

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We acclimated adult males of three Eremias lizards from different latitudes to 28°C, 33 °C or 38°C to examine whether temperature acclimation affects their thermal preference and tolerance and whether thermal preference and tolerance of these lizards correspond with their latitudinal distributions. Overall, selected body temperature (Tsel) and viable temperature range (VTR) were both highest in E. brenchleyi and lowest in E. multiocellata, with E. argus in between; critical thermal minimum (CTMin) was highest in E. multiocellata and lowest in E. brenchleyi, with E. argus in between; critical thermal maximum (CTMax) was lower in E. multiocellata than in other two species. Lizards acclimated to 28°C and 38 °C overall selected lower body temperatures than those acclimated to 33°C; lizards acclimated to high temperatures were less tolerant of low temperatures, and vice versa; lizards acclimated to 28 °C were less tolerant of high temperatures but had a wider VTR range than those acclimated to 33°C and 38°C. Lizards of three species acclimated to the three temperatures always differed from each other in CTMin, but not in Tsel, CTMax and VTR. Our results show that: temperature acclimation plays an important role in influencing thermal preference and tolerance in the three Eremias lizards, although the degrees to which acclimation temperature affects thermal preference and tolerance differ among species; thermal preference rather than tolerance of the three Eremias lizards corresponds with their latitudinal distributions.