In part I of this study a laser-based system for automatic measurement of spur gears' tooth thickness and pitch was introduced. The developed system provides an inaccuracy value on the order of 5 m, and the measurement time, for all gear teeth, was just about 1 min. In this part the experimental work is further extended to measure the tooth flank profile of spur gears. Flank profile is one of the most important factors that affect gear performance. In gear meshing, motion is transferred through contact along gear flanks. Deviations in flank profile due to errors in manufacturing or nonuniform wear result in variations in gear movement. Measurement of the flank profile can help in adjusting the gear manufacturing process, control the quality of manufactured gears, and monitor the wear of gears during action. The proposed flank profile measurement system is based on the principle of optical triangulation. The flank profile measurement setup is integrated with that of the tooth thickness and pitch, and hence tooth thickness, pitch, and profile measurements are performed simultaneously, and the measurement time for the three parameters for all gear teeth remains less than 1 min. Software is developed to graph the actual tooth profile and evaluate its deviation from nominal shape. The flank profiles measured using the developed system are in good agreement with those obtained from a wellestablished measurement method. © 2005 Society of Photo-Optical Instrumentation Engineers.

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Gears of all types and sizes are widely used in machinery and equipment. Spur gears represent the largest percentage of all gears in use, and automating their measurement has become a common goal. In this paper a new computer-assisted noncontact laser-based spur-gear measurement system is developed. The technique is based on optical obscuration and is used to measure the thickness and pitch of the test gear at a predetermined tooth height. The developed system has an inaccuracy on the order of 5 m, and the time required to measure a whole gear is 1 min. The system can measure gears with different modules and numbers of teeth. The measured dimensions were compared with those obtained with a well-established technique and are in good agreement.

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This paper investigates how to improve system reliability by modifying the configuration of its components to realize a robust design. The methodology is applied on the voltage regulator of an electronic circuit with a +5volts regulated power supply. The effect of three different design modifications on the overall system reliability has been investigated, series redundancy, parallel redundancy and parallel-series redundancy. A single factor linear regression with median rank model is used to evaluate the reliability of the three suggested designs. The inverse power law model is used to characterize the relationship between system lifetime (L) and stress (voltage) level (V). Parallel-series design showed the best results regarding system reliability. The average Time-to-Failure at 25 volts stress level for the parallel-series design was found to be 3.5 times that of the initial design, 2.5 times that of the series design and 2.17 times that of the parallel design.