CMSC 2024

 This paper investigates the utilization of photogrammetry for the measurement of two distinct power generation components, situated in New Zealand and the Philippines. Both measurements employed the V-STARS Nikon-based system. 
The application of this technology involved a collaborative effort between a photogrammetric specialist and a turbine plant engineering expert. The outcomes of both studies identified design and construction weaknesses, instigating substantial changes in plant engineering and maintenance strategies, leading to significant improvements in plant availability and reliability. 
The New Zealand project is noteworthy for its comprehensive measurement coverage, encompassing not only the main turbine structure but also the condenser, hotwell pumps, and other crucial structural components of the power generation unit. Spanning approximately 25 x 25 x 25m across four different levels, unified coordinate measurements were repeated under various operational conditions to quantify the changes the entire unit underwent.

In the Philippine project, measuring a seawater pump for the coal fired power plant auxiliaries and condenser cooling presented a unique challenge. The motor assembly is positioned above the main pump, while the main pump and ancillary components are located below sea level. Again, a unified coordinate system for all the key components was required. This project faced the added challenge of key targets being under leaking pumps, necessitating various investigations on the accuracy impact of wet targets.

Remarkably, both projects achieved high precision, maintaining accuracies consistently within the range of 30 to 50 microns across the entire measurement volume. Photogrammetric techniques not only facilitated precise measurements but also enabled the development of comprehensive action plans. These plans, rooted in meticulous data analysis, reflected observed behaviours. The New Zealand case, with its repeated measurements, offered valuable insights into dynamic changes over time, while the Philippines project underscored the adaptability of photogrammetry in challenging conditions. The cumulative findings contribute significantly to advancing the understanding of the effects of process driven changes in force and geometry and enable proactive strategies for maintenance and optimization in power generation.


 Pieter Krige 
Turbine Specialist 
373 Waingaro str 
RD1, Ngaruawahia 
Waikato, New Zealand 
Pieter@pkengineeringnz.com 

 Giuseppe Ganci 
Photogrammetrist Gancell Pty. Ltd. 
27 Browning Street Moonee Ponds, Victoria 3039, Australia gganci@gancell.com 

Photogrammetry using off the shelf low-cost camera systems is being applied to a wide variety of industrial activities where the emphasis is on determining the position, pose and potentially deformation of multiple objects within the field of view of the combined cameras over increasingly large volumes at sub-mm levels of uncertainty. Understanding and calibrating the internal imaging geometry of these camera systems to correct for systematic errors whilst maintaining the freedom to deploy different sensors and lenses with varying angles of view and image magnifications is a key enabler to meeting industrial requirements. This presentation will focus on getting the most from established bundle-adjustment based camera calibration methods. Such methods form a routine part of our low-cost multiple camera photogrammetric system deployment on tasks concerned with tracking robots, tools and objects under both laboratory and industrial situations.

Off the shelf cameras, are typified by CMOS imaging sensors purchased either as printed circuit board level devices with small threaded lens mounts, as physically enclosed units with “C” mount and larger lens mounts packaged for working in harsh environments, or as stand-alone consumer photographic cameras operating under their own power with local camera control and storage capability. No matter what type of imaging system is selected, it is necessary to numerically model the systematic geometry of the photogrammetric light path from object space to image space. The widely accepted approach of using a bundle adjustment solution permits the combination of measurements made from one or more camera images and their uncertainties along with a reference frame definition and photogrammetric lens model to estimate coordinates, positions, and poses of objects which are in the combined viewing volume of the cameras when the image set was taken. The bundle adjustment process provides a rigorous least squares error propagation enabling the uncertainties of the required location, pose to be estimated.

This presentation will describe rigid object and scene-based camera calibration methods which can be deployed in either laboratory or factory spaces illustrating results with examples drawn from our research. We will include digital consumer cameras imaging with different generations of moderate wide angle lenses typical of “off-line” or single mobile camera photogrammetry highlighting the importance of 3D spaces and calibration objects, matching camera image quality with the features being used to support the calibration process, suitable image network geometries and image coverage to achieve a reliable calibration, the parameters from bundle adjustment that give most insight into the success of the calibration process. We will also look at the calibration results from a range of mid-range quality lenses optimised for imaging with the 20MP generation of “C” mount camera units considering camera calibration outputs with respect to different lens angles of view under constant magnification. The outcome will be a set of best practice hints, tips and tricks necessary to achieve reliable and accurate photogrammetric camera calibrations. The tables below give examples of some of the areas that will be discussed: (1) variation in target image quality with lens aperture and location in the image; (2) estimated calibration parameters for five different lenses fitted successively to the same camera body; (3) variations in the internal corelations between estimated camera calibration parameters for a near zero radial distortion lens; (4) image residuals following bundle adjustment overlaid from all images taken with a given camera and (5) 3D estimated coordinate uncertainty ellipsoids estimated from bundle adjustment output covariance matrices. 

On the F35 program there are roughly 40,000 fastener holes per aircraft, and on an airframe that pushes the limits of defense aircraft manufacturing presents unique inspection challenges. The Lockheed Martin Operations Technology Metrology team in collaboration with Government Partners have approached these challenges over the years through the development of new technology and methods that enable 3D scanning for difficult bore hole inspections and critical low observable coatings measurement.

This presentation will go over the two innovative technologies and methods the team has developed for characterizing internal surfaces of fastener holes and validating external fastener flushness coating measurements, and how these tools enable producing a better and more affordable 5th Generation aircraft.


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Metrology, the science of measurement, plays a crucial role in various industries, ensuring product quality, process control, and compliance with standards. Over the years, traditional metrology techniques have been widely used for measurement and inspection purposes. However, the advent of computer-aided metrology has revolutionized the field, offering numerous advantages over traditional methods. However, uncertainties associated with Computer-Aided Metrology (CAM) measurements continue to pose challenges in achieving accurate and reliable results. This publication aims to bridge the gap between CAM and traditional metrology by addressing uncertainties and proposing strategies to mitigate them.

The publication begins by highlighting the benefits and limitations of CAM compared to traditional metrology methods. Traditional metrology relies on manual measurement tools, such as calipers, micrometers, and gauges, which require human intervention and interpretation. Computer-aided metrology, on the other hand, utilizes advanced hardware and software systems, including coordinate measuring machines (CMMs), laser scanners, laser trackers, and optical measurement devices, which automate the measurement process and provide accurate and reliable data.

The publication digs into the various sources of uncertainties in CAM, including measurement equipment, software algorithms, and environmental factors. It explores the impact of these uncertainties on measurement accuracy and repeatability, emphasizing the importance of error analysis and uncertainty estimation in CAM processes. To bridge the gap between CAM and traditional metrology, the presentation proposes strategies to address uncertainties. These strategies may include calibration and verification of measurement equipment, validation of software algorithms, proper training, and implementation of quality control measures.

In conclusion, this publication provides valuable insights into addressing and minimizing uncertainties in CAM and traditional metrology. By understanding the sources of uncertainties and implementing effective strategies, organizations can maximize the potential of CAM while ensuring accurate and reliable measurements.