In this study, we built a monocular visual inertial odometry (VIO) dataset with a proposed self-calibrating platform for an inertial measurement unit (IMU). For a learning-based method, lack of database is the biggest limitation. One goal of this study is to generate a high-quality VIO database. Meanwhile, a properly calibrated inertial measurement unit (IMU) is critical for improving VIO system accuracy and precision. However, a professional IMU calibration tool is usually expensive and large. The proposed self-calibrating platform shows its benefits in eliminating the manual work in calibration and reducing the cost of the expensive platform, which brings more opportunities to students and researchers. This self-calibrating system was useful for collecting monocular visual inertial odometry datasets while driving. . The calibrated IMU generates 14 numbers at 100Hz: time, 3-axis accelerometer measurements, 3-axis gyroscope measurements, 3 Euler angles, and 4 quaternions. This VIO system is composed of a monocular camera, GoPro Hero 3, an IMU, BNO055, and a GPS, ANT-555. The sensors are mounted on a John Deere Gator™ Full-Size Crossover Utility Vehicle and are operated on an Intel NUC, a mini-size computer. The final dataset contains monocular images, IMU measurements, and GPS outputs.

A thermodynamic analysis and optimization of four supercritical CO2 Brayton cycles were conducted in this study in order to improve calculation accuracy; the feasibility of the cycles; and compare the cycles’ design points. In particular, the overall thermal efficiency and the power output are the main targets in the optimization study. With respect to improving the accuracy of the analytical model, a computationally efficient technique using constant conductance (UA) to represent heat exchanger performances is executed. Four Brayton cycles involved in this compression analysis, simple recaptured, recompression, pre-compression, and split expansion. The four cycle configurations were thermodynamically modeled and optimized based on a genetic algorithm (GA) using an Engineering Equation Solver (EES) software. Results show that at any operating condition under 600 °C inlet turbine temperature, the recompression sCO2 Brayton cycle achieves the highest thermal efficiency. Also, the findings show that the simple recuperated cycle has the highest specific power output in spite of its simplicity.

Scanning beam interference lithography (SBIL) technology is applied to produce large-area grating with nanoscale phase accuracy. One of the greatest challenges of SBIL is locking interference fringe to a moving substrate with nanometer spatial phase error, which requires measuring the fringe phase with subnanometer precision. We are developing a novel homodyne phase-locking interferometer (HPLI) to meet the harsh measurement requirements. The HPLI offers high precision phase measurements as well as the direction recognition of the interference fringe drift with a four-orthogonal detection system. However, nonlinearity error impacts the phase measurement accuracy of HPLI with nanometer scale, which is mainly due to polarization mixing. In this paper, we present a method to estimate and compensate nonlinearity error in real time by applying an extended Kalman filter algorithm. The simulation results show that the method can effectively eliminate the nonlinearity error.

Vibration isolators have been widely used to keep the target object from the ground vibration in order to improve the measurement accuracy. Nowadays, the ultra-low frequency vibration isolator based on a two-stage structure shows the best performance. Traditionally, vertically suspended springs are usually applied as the second-stage. As the requirement of the low stiffness, the springs need to be long, which brings the disadvantages of relatively large size and small allowable load. A novel ultra-low frequency active vertical vibration isolator is proposed in this paper, which applies geometric anti-spring (GAS) instead of the second-stage suspended springs. The isolated object (the second stage) is supported by GAS fixed on an inner frame (the first stage), and the inner frame is hung with supporting springs from the base of the vibration isolator. The inner frame is driven by a voice coil to track the motion of the isolated object according to the relative motion signal detected by a photoelectric detector. Ideally, GAS provides zero restoring force for the object, thus realizing a long natural resonance period. Experimental results show that the isolator can achieve a resonance period of 14.7 s, compared with a simulated result of 20.7 s. Therefore, it is accessible to reduce the isolator’s volume and increase the allowable load by replacing the traditional second-stage suspended springs with GAS, without harming the vibration isolation effect. Promisingly it will be applied in free-falling and atomic-interference absolute gravimeters, and other precise measurements.

Modern methods for analyzing motor vehicle deformation rely upon a force-deflection analysis to determine deformation work energy. Current methods provide acceptable accuracy when calculating the velocity change of vehicles involved in a collision but require significant modification to accommodate oblique and low-velocity collision events. The existing algorythms require vehicle-specific structural stiffness coefficients for each colliding vehicle, determined from full-scale impact testing. The current database of vehicle structural stiffness values is generated mainly through government safety standard compliance testing and is quite extensive for frontal impacts involving passenger cars and many light trucks and SUVs. However, the database is devoid of specific crash testing necessary for deformation analysis of rear and side structures of many vehicles. Additionally, there remains a dearth of structural stiffness coefficients for heavy commercial vehicles, buses, recreational vehicles, heavy equipment and motorcycles, rendering the application of the current force-deflection analysis approach useless for many impacts involving such vehicles. The research presented, known as the Generalized Deformation and Total Velocity Change System of Equations , or G-DaTA ΔV ™, develops an accurate, reliable and broadly-applicable system of equations requiring knowledge of the structural stiffness coefficients for only one vehicle, rather than both vehicles involved in a collision event, regardless of the impacted surfaces of the vehicle. The developed methodology is inclusive of non-passenger vehicles such as commercial vehicles and even motorcycles, and it also accommodates impacts with objects and surfaces not supported by the current structural stiffness coefficient database. The G-DaTA ΔV ™ system of equations incorporates the linear and rotational collision contributions resulting from conservative forces acting during the impact event. The contributions of the G-DaTA ΔV ™ system of equations are as follows: 1. Consideration of non-conservative contributions from tire-ground forces and inter-vehicular frictional energy dissipation commonly present during non-central collision configurations. 2. Ability to solve for collision energy of a two-vehicle system using a single structural stiffness for only one of the colliding vehicles using work/energy principles. 3. Determination of the total velocity change for a vehicle resulting from a given impact event, which results from conservative and non-conservative force contributions. 4. The ability to predict the time period to reach maximum force application during an impact event, allowing for the determination of the peak acceleration levels acting on each vehicle during an impact. The results of applying the G-DaTA ΔV ™ to full-scale impact tests conducted as part of the RICSAC collision research will be presented. Additionally, analysis of real-world collision data obtained through the National Automotive Sampling System demonstrates a close correlation with the collision values recorded by the vehicle event data recorders (EDRs) as part of the supplemental restraint system airbag control moducles (ACM). Compared to other analysis methods currently used, determining the total velocity change of a vehicle due to a collision event is achieved with a higher level of both accuracy and precision when using the G-DaTA ΔV ™. The generalized approach of the G-DaTA ΔV ™ applies to collisions ranging from the simple collinear impact configuration to the most rigorous conditions of offset and oblique impacts. The comprehensive formulation provides greater utility to the researcher or forensic analyst in determining the contributions of the vehicle-roadway-driver environment as it relates to real-world collision events and their effects on vehicle and highway safety.

Wire Electrical Discharge Machining (WEDM) is a versatile process to generate intricate and complex shapes on conductive work material with high dimensional accuracy and surface finish. Since the process is stochastic, its input parameters play critical role for achieving desired accuracy and precision of the component. Inconel 718, High-Strength-Temperature-Resistant (HSTR) material, has wide applications in the field of aerospace, automobile, mould making and medical industries. Hence, machining of Inconel 718 using WEDM is a challenging task. Also experimentation on Inconel 718 with WEDM is costly as well as time consuming process. Therefore to study the behavior of WEDM process with different process parameters for effective and efficient operation, process modeling and simulation using appropriate software is highly essential. In the present investigation, a 3-D single spark finite element thermal model for WEDM process has been developed using ANSYS software. This model has some more realistic assumptions like heat flux following Gaussian distribution and spark radius as a function of time and energy. Plasma incident region is meshed by keeping elemental size equal to one tenth of entire plasma radius, so that exact ten elements can be fitted. Identified elements were thermally loaded by applying element wise different temperatures for getting more accurate temperature distribution profile. This profile was found to be having crater shape matching with earlier Finite Element Models (FEM) available in the literature. Along with the shape, it also helps to decide the elements having temperatures greater or equal to melting point leading to estimate Material Removal Rate (MRR). Later on single spark MRR can be used to estimate multi-discharge-MRR by calculating pulse rate. Model MRR is validated with the experimental MRR which show a very good agreement, but little variation. This variation in the modeling could possibly due to assumptions like no delay in ignition, non-deposition of recast layer (100% flushing efficiency), etc. The factors like incomplete flushing of debris and inter-electrode gap arcing cause the variation in machining conditions thus reducing the actual MRR. In the present investigation, the use of dielectric is considered only for convection, but in reality, it acts as an insulator, coolant and also as debris remover. Melting and vaporization of material is the main phenomena for material removal. Dielectric fluid partially removes the molten metal because at the same time, the molten metal is under very high pressure due to plasma channel. Its adhesive property resists the material removal. It is very difficult to incorporate all real effects in the model, however the obtained results in the present study show good agreement between model MRR and experimental MRR within 10% variation.

A multi-wavelength light interference method for the measurement of lubricating film thickness was proposed for the improvement of convenience and accuracy of monochromatic light interferometry. Through the successive analysis of the hypothetical curves and the revised curves of three-wavelength light interference, the procedures of this method were discussed in detail. Then three-wavelength light interference method was applied to measure the lubricating film thickness of base oil under a specific condition. In comparison with the numerical results of Hamrock-Dowson formula, it was concluded that the multi-wavelength light interference method is applicable for the measurement of lubricating film thickness. With this method, the only requirement is the images which captured in stationary and purposed conditions, and higher measurement accuracy can be achieved.

One of the industrial applications of ultrafiltration membrane system is water purification and wastewater treatment. Membranes act as physical barriers by eliminating particles such as pollen, yeast, bacteria, colloids, viruses, and macromolecules from feed water. The effectiveness of the membrane to separate particles is determined by its molecular weight cut-off and feed water characteristics. Typically, pre-filtration strainers are installed upstream of an ultrafiltration membrane system to separate large particles from the flow stream. The criteria for selection of the strainer pore size is unclear and is often determined by the feed water average particle size distribution. This paper is motivated by the hydraulic loading failure of a 125 μm strainer by average feed water particle size of 1.6 μm when the volumetric flow is at or greater than 40% of the rated design flow capacity. The objective of this paper are to: a) determine if the feed particle size distribution is a sufficient parameter for selection of pre-filtration strainer, b) evaluate the effect of feed flow velocity on strainer performance, and c) enhance strainer performance using vortex generator. In this experimental study, a Single Particle Optical Sensing, Accusizer, was used to analyze particle size distribution of five water samples collected at strainer feed, strainer filtrate, and strainer backwash. All samples were analyzed using a lower detection limit of 0.5 μm. In order to capture more counts of the larger particles present in the sample, a second analysis was done for each sample at a higher detection limit, 5.09 μm for feed sample, and 2.15 μm for the rest of the samples. Particle size data based on individual detection limits were statistically combined to generate comprehensive blended results of total number and total volume. The volume was determined based on assumption that each particle is spherically shaped. The Particle Size Distribution Measurement Accuracy is ±0.035 μm. Results showed that the feed particle size diameter and volume was insufficient to determine strainer size. Particle size distribution is needed at the feed, filtrate, and backwash to evaluate the strainer particle separation efficiency. It was observed that the total particle count in the filtrate (4.4 × 10 6 ) was an order of magnitude higher than the feed (3.2 × 10 5 ). Specifically, the total count for particles with diameter less than 7.22 μm were higher in the filtrate while larger particle size ≥ 7.22 μm were more in the feed stream. It appears that the large particles in the feed breaks down into smaller particles at the strainer interface and the small particles (≤ 7.22μm) passed through the pore into the filtrate. The particle breakdown, detachment of particles in the strainer pore into the filtrate, and particle to particle interactions are enhanced by increase in flow velocity hence increasing the hydrodynamic shear that acts on attached particles. A vortex generator inserted in to the strainer reduced pore clogging and pressure drop.

It is well known that in mechanical engineering production systems, an estimated 15–30% of the manufacturing cost is towards deburring operations. While small components may be deburred using one of the many technologies available, larger components like castings have to be deburred manually or in recent times with assistance from robots. In fact, most of the present mass production systems aim towards automation and robotics for carrying out these operations. At present, substantial research effort is being spent towards robotic deburring. The major issue with robotic deburring is that the tool path gets affected in view of the interaction of cutting forces between the work piece and robot. The objective of present research is to carry out multidirectional investigations on robotic deburring using a SCARA robot, the application being confined mostly to the deburring of circular components. It is well known that SCARA (selective Compliant articulated Robot Arm) is a robotic manipulator with four degrees of freedom (3 rotary and 1 prismatic) and is preferred where speed, high precision and accuracy is required. In this work investigations on SCARA robot are carried out for different sized component which is positioned at different distances with respect to the base which leads to present a solution to component placement with in the workspace (solvability analysis) and also presents the placement position of a deburring component with minimum joint torques. A brief discussion on simulation of SCARA robot with force feedback control is presented, since this plays a major role in the maintenance of the path in the presence of varying cutting forces, and also presented kinematic and dynamic analysis of a SCARA robot for deburring of rectangular paths. The overall kinematic and dynamic analyses of the SCARA robot with different positional configurations of the workpieces in the workspace enables the energy to be computed for assessing the most desirable state for deburring which consumes the least energy. This data thus obtained enables a comparison and pseudo-optimize the best configuration for the entire deburring operation. Although the methodology is at present confined mostly to circular paths, similar analyses can be carried out for rectangular path deburring (similar to those on engine cylinder heads) and oblong and elliptical profiles which are commonly found in many engineering components.

In large assemblies, the perpendicularity of a bolting hole has remarkable effects on the fatigue life and fluid dynamic configuration. While the Computer Aided Design (CAD) model of complexly curved workpieces is hardly satisfied because of manufacturing errors, it is very necessary to measure the normal direction in robotic drilling. One advisable approach is to arrange four laser displacement sensors at the vertices of a rhombus whose center aims at the drilling position. The influencing factors of the measurement precision are firstly discussed in this study, and a novel method to optimize the arrangement size of the displacement sensors for higher precision is introduced. The measurement error for the normal direction consists of the principle error and instrumental error, caused by inconstant curvature of the surfaces and distance measuring errors of instruments, respectively. When the displacement sensors are arranged closer to each other, the principle error will be decreased, whereas the instrumental error will be increased. After the curvature feature of the surface is obtained with the introduced method, the graph of the measurement precision and the arrangement size is plotted. Then, the graph can contribute to developing an optimized design of arrangement size for higher precision. Finally, an example of the curvature obtainment and the arrangement optimization is given. The experimental results show that the optimized design has achieved a higher precision of ± 0.17° for α Y and ± 0.26° for α X , whereas the precision of another design is about ± 0.21° for α Y and ± 0.29° for α X . The proposed optimization method will bring greater benefit for complexly curved surfaces in practical products and it offers a chance to optimize the arrangement during design phase with little costs.

Sub-micron accuracy and precision in measuring unconstrained, spatial motion is pivotal in science and engineering. It imposes stringent requirements on the accuracy, reliability, and invasiveness of sensing devices (including lasers, lidar sensors, or optical scales). While the capabilities of these devices have seen dramatic improvements in the last decades, the needs for sub-micron accuracy, low-invasive sensors greatly outpace the available solutions. The root cause of measurement difficulties is a conflict between the very nature of motion (simultaneous translations and rotations relative to a chosen reference base) and the fundamental requirement of measurement accuracy known as the Abbe principle. Small and accurate Microsystems Technology based inertial sensors (accelerometer and gyroscopes) can alleviate, or at least significantly mitigate, many of the current difficulties. If contained in small Inertial Measurement Units (IMU) and equipped with a wireless signal transmission, they can be placed on or very close to the objects whose motion is to be measured. Furthermore, as long as the IMU, its fixture, and some region of this object around the fixture can be considered as rigid, coordinate transformation rules facilitate converting signals measured by IMU into translations and rotations of any point in this rigid region. Consequently, a virtual 6-DOF sensor can be created. Its dimensions are infinitesimally small, and it can be “placed” anywhere within the above rigid region. In particular, it can be placed such that it is collinear with the displacements of the cutting tool or robot’s end effector, and satisfies the Abbe principle. We present a High Accuracy, Low-Invasive Displacement Sensor (HALIDS) for application in manufacturing and in engineering design. The sensor is capable of measuring simultaneously 6-degrees-of-freedom displacements of objects. Its short term resolution is down to 0.1 nanometer and accuracy better than 1 micron. The sensor can be built small, light and wireless. Results from experimental evaluation of two prototype versions are presented.

Useful prediction of the kinematics, dynamics, and chemistry of a system relies on precision and accuracy in the quantification of component properties, operating mechanisms, and collected data. In an attempt to emphasize, rather than gloss over, the benefit of proper characterization to fundamental investigations of multiphase systems incorporating solid particles, a set of procedures were developed and implemented for the purpose of providing a revised methodology having the desirable attributes of reduced uncertainty, expanded relevance and detail, and higher throughput. Better, faster, cheaper characterization of multiphase systems result. Methodologies are presented to characterize particle size, shape, size distribution, density (particle, skeletal and bulk), minimum fluidization velocity, void fraction, particle porosity, and assignment within the Geldart Classification. A novel form of the Ergun equation was used to determine the bulk void fractions and particle density. Accuracy of properties-characterization methodology was validated on materials of known properties prior to testing materials of unknown properties. Several of the standard present-day techniques were scrutinized and improved upon where appropriate. Validity, accuracy, and repeatability were assessed for the procedures presented and deemed higher than present-day techniques. A database of over seventy materials has been developed to assist in model validation efforts and future designs.

Electronic packaged devices are becoming increasingly smaller in size and higher in density while requiring higher performance and superior reliability. Warpage is one of the crucial factors for the thermo-mechanical reliability of electronic packages and warpage control becomes a more crucial process during the printed wiring board (PWB) fabrication and package assembly processes. This requirement necessitates more accurate methods of measuring warpage. The fringe projection methods are recent trends for measuring the warpage of chip packages, PWBs, and PWB assemblies because of their noncontact, full-field, and high-resolution measurement capabilities. This paper presents a comparison of two fringe projection methods: laser fringe projection (projection moiré) and digital fringe projection. Experimental results show that digital fringe projection has higher practical resolution, and better accuracy and precision than laser fringe projection.

This study experimentally measured the efficiency of new generation bicycle hub gears. Since efficiency of bicycle drivetrains can be very close to 100% and vary by small amounts between gears bias errors and measurement accuracy must be identified and controlled. For this study an ergometer frame was altered to support research test equipment. A 1 HP motor and gearbox were used to drive the crankshaft. The hubs were attached directly to the steel flywheel using shortened bicycle spokes, eliminating extra chains or drive components. This setup minimizes measurement uncertainty in the drivetrain. Force-transducers were used to measure the motor and flywheel torque, and two magnetic reed switches were used to measure the speed of the motor and flywheel. Efficiency for each individual gear in each hub was calculated for 14 different power speed combinations. The efficiency of each gear was plotted against flywheel Torque, and an exponential model was fit to the data. This model accounts for known variations in efficiency with power and speed, and provides insight into the torque-speed-efficiency relationship. Four internally-geared hubs were measured and compared with a single speed direct drive train and a belt drive. The internal planetary gear hubs measured were the Shimano Alfine 11, Rohloff 500/14 Speedhub, SRAM Dual-Drive, and the Sturmey Archer X-RK8(W). In addition a single-speed direct chain drive, a single-speed belt drive, and a 7-speed derailleur system were measured. The efficiency of the Shimano Alfine ranged from 90.4% to 96.6%. The efficiency of the Rohloff speed hub ranged from 95.8% to 99.5%. The efficiency of the Sturmey Archer hub ranged from 84.6% to 99.8%. The efficiency of the single speed chain drive was found to be 99.71% and the belt drive 98.0%. The efficiency of the 7-speed derailleur ranged from 97.7% to 99.4%. These values found for efficiency are comparable to other studies.

The testing facility called the Outdoor Collector Test Loop (OCTL), which is located at the Solar Industrial Mesa Top Area (SIMTA) of National Renewable Energy Lab (NREL), measures the optical efficiency of parabolic trough collectors. It uses a dual-axis, large-payload solar tracker to hold a parabolic trough collector module and track the sun. Due to the growing need for measurement accuracy and efficiency, a new tracking control system for the tracker has been acquired and successfully commissioned as of February 2012. As part of the customization needed to address the unique testing requirements at the OCTL, new tracking modes have been designed and embedded into the new controller. In particular, the incidence angle modifier (IAM) and fixed-azimuth modes allows the OCTL to readily measure the IAM values for a trough collector, significantly improving the speed and efficiency of IAM data collection compared to the previous controller (with test times of days versus weeks). The Siemens S7 1200 PLC integrates various hardware components (such as the hydraulic pump, encoders, sun sensor and wind sensor) through corresponding communication channels, and a Simatic HMI panel provides a powerful user-friendly interface for operation, monitoring, and diagnostics. In addition, NREL integrated the Siemens tracking control program with the existing LabVIEW program that serves as a user interface of the thermal fluid loop, and calibrated the tracking platform as a whole to characterize its tracking accuracy. At last, the challenges and opportunities for the control system in the area of concentrating solar power (CSP) are briefly discussed.

Cutting operations using blades appear in several different industries such as food processing, surgical operations, gardening equipment, and so forth. Many practitioners of cutting operations will notice that it is easier to cut something by pressing and slicing at the same time versus doing each motion individually. They will also notice that certain angles or certain blade geometries make it easier to cut certain materials. As our society continues to increase our technological prowess, there is an ongoing need to better understand the underlying causes of simple tasks such as cutting so that cutting operations can be performed with more precision and accuracy than ever before. For many applications it is not possible to achieve the most optimum cutting force, cutting angle, and push to slice ratio and a compromise must be made in order to ensure the functionality of a cutting device. A means of objectively and efficiently evaluating cutting media is needed in order to determine the optimum parameters such as cutting force, cutting angle, and push to slice ratio for certain applications. The approach taken in this work is to create a testing apparatus that uses standard cutting media and performs controlled cutting operations to determine key parameters to specific cutting operations. Most devices used for performing experimental controlled cutting operations are limited to a single axis of motion, thus not incorporating the effect of the push to slice ratio. The device created and discussed in this paper is capable of performing controlled cutting operations with three axes of motion. It is capable of accurately controlling the depth of cut, push to slice ratio, and angle of cut in order to accurately capture motions seen in typical cutting operations. Each degree of freedom on the device is capable of withstanding up to 1550 N of cutting force while still capable of maintaining smooth motions. The device is capable of controlling the velocity of the push and slice motions up to 34 mm/s. Depth of cut, for both pushing and slicing, the reaction forces, and the angle of cut are all controlled and measured in real-time so that a correlation can be made between them. Data collected by this device will be used to investigate the effects of the push to slice ratio and angle of cut on cutting force and overall quality of cutting operations. Preliminary testing in wood test samples evaluates the effectiveness of the device in collecting cutting data. This device will also be used to validate several finite element analyses used in investigating cutting mechanics.

Air leakage is one of the most significant energy waste factors in compressed air systems which account for about 10% of total industrial energy consumption. It is estimated that about 10%∼40% of the compressed air is wasted through leakage in most plants. A new ultrasonic leak detection method based on time delay estimation (TDE) is proposed to locate the compressed air leak for preventing energy waste in pneumatic systems. The accuracy of detection is highly dependent on the performance of the TDE method. Performances of six typical TDE methods based on generalized cross correlation (GCC) are compared, and these methods are the basic cross correlation (BCC), the Roth impulse response, the phase transform (PHAT), the smoothed coherence transform (SCOT), the WEINER processor, and the Hannan-Thomson (HT) processor. The experimental results show that: Firstly, the accuracy and precision of time delay estimation increases with the observation interval for all these methods. Secondly, the success rates of Roth, PHAT, SCOT and HT are much higher than that of BCC and WEINER, among which the HT processor performs best with a highest success rates closely followed by the PHAT processor. Thirdly, the HT processor which is a maximum likelihood estimator gives the minimum standard deviation of the time delay estimate; however, the standard deviations of all these GCC methods are very small. The HT processor outperforms other GCC methods in terms of success rate and standard deviation. Consequently, it is preferable to apply the HT processor for this particular purpose.

In this paper, we present a theoretical description of a novel self-calibratable MEMS absolute temperature sensor. Our analysis suggests that the sensor might provide accurate and precise measurements over a large range of temperatures. Due to the high accuracy and precision required for some experiments and devices, such as studies involving fundamental laws or sensor drift due to thermal expansion, accurate temperature sensing is necessary. Conventional temperature sensors require factory calibration, which significantly increases the cost of manufacture. Using the equipartition theorem, nanotechnologists have long determined the stiffness of their atomic force microscope (AFM) cantilevers by measuring temperature and the cantilever’s displacement. Since we have determined how to measure MEMS stiffness, we propose that the reverse can be done, i.e. determine temperature by measuring MEMS stiffness and displacement. In this paper we describe our method for accurately and precisely measuring nonlinear stiffness and expected displacement. We also provide an expression for quantifying the uncertainty in measuring temperature.

Microscope has being limited by the depth of focus, while the focused image is clear, the defocused images are fuzzy and fuzzy degree of the object images vary with different defocused distances. This paper presented a 3D reconstruction method based on a defocused microscopic image. After the defocused microscopic image is divided the microscopic into M × N regions, the fuzzy degree of each region is quantitatively evaluated. A corresponding curve of the relation between fuzzy degree and defocus distance is drawn by the presented algorithm in this paper, and then the three-dimensional characteristics of objects are reconstructed. This method has the merits of little computation, low cost and high speed. And M and N values can be changed according to the needs of the measurement accuracy.

Precise and accurate manufacturing became an obligation in aerospace industry in last decades. Uniformity of turbine blades, nozzle geometries, gaps, diameter changes and misalignment issues in turbine assemblies have to be inspected carefully in terms of quality and exactitude. Like broadly used aluminum and titanium based materials, ceramics and special coated composites are also used in aerospace applications. A wide selection of measurement methods used is based on intensity sensing and range imaging. With the recent development in advanced laser techniques, new methods that involve non contact measurement methodologies are being investigated by many industries. In addition to their accuracy and precision, speed of measurement and compactness of such systems are also of high significance. In this paper, a hybrid approach consisting of laser based triangulation, photogrammetry and edge detection techniques has been investigated to measure inner surfaces of parts that have limited access, especially where human presence is impossible. The system is capable of detecting and measuring misalignments, gaps, inclinations as well as surface variations such as cracks and dents. The system employs the accuracy and speed of measurement of triangulation systems and combines these with the mobility and cost effectiveness of photogrammetry and edge detection techniques. In addition to gap and alignment offset inspections, the methodology and the instrument enables angle measurements, detailed surface texture examinations and other inspections needed to be done inside assemblies with narrow openings, with its compact body. Additionally, a comprehensive experimental study has been conducted to show that two different edge detection methods, namely, the “Simple Edge Tool” and “Straight Edge (Rake) Tool” can be used with great accuracy and precision for such measurement purposes. With this system, any surface, whether they have a reflectance or not, can be scrutinized.