Technology for acurate and low power measurements

Abstract: Modern measurement systems can be found almost in any part of everyday life. Measurement accuracy of such systems is a vital factor which often associated with the system's overall performance and costs. The accuracy of a system is closely related to the system's power consumption. The fact that more and more of measurement systems work autonomously with limited power supply, places the power consumption issue on the same level as the issue of accuracy. The ability of a system to work long time without being adjusted (without human interference) reduces the total life time cost of the system and makes it more attractive to a potential customer. Consequently, the problems of measurement accuracy and low power consumption of electronic systems have gained a great consideration in the industry and research and there are still more findings to be made. This is necessary for the evolution technology in society. This work presents the technologies and strategies for accurate and low power measurements. Using the examples from two scientific areas (robotics and electronics), it is shown how the analysis of different error sources can produce more accurate and less expensive systems. Firstly, a new navigation system based on modern CMOS image sensors is presented. This navigation system is designed for and tested on a wheel-chair mobile robot. The strengths of such navigation systems are greater simplicity and less costs compared to laser based navigation systems. The error sources of both systems are presented and the accuracies are analyzed. Secondly, A/D conversion technology is discussed and conventional technology is compared to a new level-crossing architecture. As a result of this analysis, a building block for a level-crossing architecture is designed - a propagation delay stable comparator. The present licentiate thesis includes three scientific papers, which have contribution in the areas of robotics and electronics. The thesis specifically presents a compression algorithm that can be used in the lens distortion compensation and the design strategy with the measurement results for a propagation delay stable comparator.