Advanced In-flight Measurement Techniques Research Articles

Оптико-электронный комплекс измерения деформации поверхности в режиме реального времени

The problem of measuring deformations is relevant for many branches of science and technology. Most often it is encountered in the automotive, construction and aircraft industries. In the latter case, deformation measurements are of vital importance due to a number of features specific to the industry. At present, the task of carrying out investigations in a flight experiment is of relevance in the aircraft industry. The international research projects called Advanced In-Flight Measurement Techniques (AIM and AIM2) are devoted to development of such methods. A new version of the videogrammetric method, called the Image Pattern Correlation Technique, has been proposed as a result of implementing these projects. The above mentioned technique, which is based on cross-correlation processing of images, has successfully been applied in performing flight tests for different aircraft types ranging from Evektor VUT100 Cobra to Airbus 380. The developed optoelectronic system for real-time measurements of 3D surface deformations is considered. The system is developed on the basis of the Image Pattern Correlation Technique and makes it possible to carry out measurements in a full-scale experiment and in real time. A detailed description of the method and the system constituent parts is given. An image processing algorithm implemented using the DeformVision software is presented. For checking the system operability, experimental studies using a deforming surface simulator were carried out. The study results have shown that the developed system has an accuracy of 0.5 mm on a surface area of 900 cm2 at a displacement amplitude of 10 mm. The system software allows real-time measurements to be carried out at a rate of no less than 5 measurements per second.

In-flight wing deformation measurements on a glider

ABSTRACTFlight testing is both vital for collecting data for aeronautic research and at the same time fascinating for its contributors. Taking a glider as a versatile test bed example, this paper presents a transnational measurement campaign within the framework of a collaborative project funded by the European Commission. This project Advanced In-Flight Measurement Techniques 2 (AIM²) is a follow-up of Advanced In-Flight Measurement Techniques (AIM) and dedicated to developing and enhancing promising optical metrology for various flight test applications up to an industrial level.The Image Pattern Correlation Technique (IPCT) and infrared thermography (IRT) are two of these modern non-intrusive measurement methods that were further developed and applied to the glider test bed within the scope of AIM². Focusing on optical deformation measurements with IPCT the experimental setup, the flight testing and results are summarily discussed. Gliders are not commonly used flight test platforms, which is why this contribution concludes with some lessons learned in general and especially related to the presented application. The experience to be shared with the flight testing community addresses equipment preparation, data collection and processing as well as how to meet official requirements and perform test flight operations in a dense controlled airspace.

In-flight measurements of propeller blade deformation on a VUT100 cobra aeroplane using a co-rotating camera system

Knowledge of propeller or rotor blade behaviour under real operating conditions is crucial for optimizing the performance of a propeller or rotor system. A team of researchers, technicians and engineers from Avia Propeller, DLR, EVEKTOR and HARDsoft developed a rotating stereo camera system dedicated to in-flight blade deformation measurements. The whole system, co-rotating with the propeller at its full speed and hence exposed to high centrifugal forces and strong vibration, had been successfully tested on an EVEKTOR VUT 100 COBRA aeroplane in Kunovice (CZ) within the project AIM2—advanced in-flight measurement techniques funded by the European Commission (contract no. 266107). This paper will describe the work, starting from drawing the first sketch of the system up to performing the successful flight test. Apart from a description of the measurement hardware and the applied IPCT method, the paper will give some impressions of the flight test activities and discuss the results obtained from the measurements.

Integration of optical measurement methods with flight parameter measurement systems

During the AIM (advanced in-flight measurement techniques) and AIM2 projects, innovative modern techniques were developed. The purpose of the AIM project was to develop optical measurement techniques dedicated for flight tests. Such methods give information about aircraft elements deformation, thermal loads or pressure distribution, etc. In AIM2 the development of optical methods for flight testing was continued. In particular, this project aimed at the development of methods that could be easily applied in flight tests in an industrial setting. Another equally important task was to guarantee the synchronization of the classical measuring system with cameras. The PW-6U glider used in flight tests was provided by the Rzeszów University of Technology. The glider had all the equipment necessary for testing the IPCT (image pattern correlation technique) and IRT (infrared thermometry) methods. Additionally, equipment adequate for the measurement of typical flight parameters, registration and analysis has been developed. This article describes the designed system, as well as presenting the system’s application during flight tests. Additionally, the results obtained in flight tests show certain limitations of the IRT method as applied.