Periodic Reporting for period 4 - FLAPSENSE (Optical Sensor System for Realtime Proprotor Flapping Angle Monitoring)
Okres sprawozdawczy: 2022-09-01 do 2023-12-31
The main objective of the project FLAPSENSE is to design and manufacture a contactless measurement system for real time monitoring of proprotor flapping angle. The system will be integrated in the proprotor assembly and co-rotates with the rotor. It will be based on an highly accurate optical sensing method providing the actual flap motion of the rotor blade to the avionic system. The FLAPSENSE system in the project will finally be flight tested in the frame of the NextGenCTR Demonstrator.
The FLAPSENSE project will enable real time monitoring of the movements and deformations of a proprotor hub during real operation. It will enable a direct observation of the rotor and deliver new insights in “what’s going on in the rotating frame”, especially if the rotation axis is tilted and thus will contribute to the flight safety of rotorcrafts. One of the main impacts of the FLAPSENSE concept is to contribute to delivering superior vehicle productivity and performance. FLAPSENSE will realise measurements in a non-intrusive way reducing components interconnecting the hub and the proprotor, reducing wear and as such reducing weight, operational costs and maintenance.
Besides the direct contribution to the measurement objective, the FLAPSENSE project will be a pioneering activity for the application of other optical measurement techniques (e.g. overall blade deformation, local surface pressure, transition or flowfield around the blade). On the one hand it will solve difficulties in the installation of optical measurement systems in the rotating frame, on the other hand the real-time image processing software to be developed can also be used for other camera installations (e.g. landing gear measurements, wing deformation measurements, control surface monitoring, active control).
The FLAPSENSE project will enable real time monitoring of the movements and deformations of a proprotor hub during real operation. It will enable a direct observation of the rotor and deliver new insights in “what’s going on in the rotating frame”, especially if the rotation axis is tilted and thus will contribute to the flight safety of rotorcrafts. One of the main impacts of the FLAPSENSE concept is to contribute to delivering superior vehicle productivity and performance. FLAPSENSE will realise measurements in a non-intrusive way reducing components interconnecting the hub and the proprotor, reducing wear and as such reducing weight, operational costs and maintenance.
Besides the direct contribution to the measurement objective, the FLAPSENSE project will be a pioneering activity for the application of other optical measurement techniques (e.g. overall blade deformation, local surface pressure, transition or flowfield around the blade). On the one hand it will solve difficulties in the installation of optical measurement systems in the rotating frame, on the other hand the real-time image processing software to be developed can also be used for other camera installations (e.g. landing gear measurements, wing deformation measurements, control surface monitoring, active control).
As part of the FLAPsense project, a sensor system for the non-contact measurement of movement (in particular flapping and cross-axis flapping) of the NGCTR's prorotor hub was developed from scratch. Based on the given requirements, a total of five concepts were evaluated and a favoured solution, Concept 1, which is based on camera sensors, was further developed through the System Requirements Review (SRR), the Preliminary Design Review (PDR) and the Critical Design Review (CDR) up to the updated final design. All development steps were documented in the form of project results and scientific publications. Unfortunately, the project encountered several major delays. In order to maximize the possible outcome of the project it was decided after the 3rd reporting period to amend the project contract and rescope FLAPsense from the initial plan to completely develop an airborne system towards a two-lane approach with the development of the airborne system up to the CDR and in parallel building and testing a research demo sensor system made of COTS parts. The first lane, i.e. the final design of the airborne sensor system has fully been achieved within the project duration. The second lane regarding the demonstration of the system was nearly completed as only the demonstration test on the rotating test rig has not been completed in within the project.
Due to the fact, that the FLAPsense sensor concept is very promising and most of the extensive work for this test still has been done, i.e. design and manufacturing of the Marty test rig, planning of the test, design and manufacturing of the preliminary model of the sensor system (= the research demo sensor system), it has been agreed to perform this demonstration test after the end of the project at on own costs and risk. Results of this Demo-Test will be used for further maturation of the system and realization of the CDR sensor design.
With regards to the exploitation the achievements made within the FLAPsense project have valuable potential for other future applications. In general, the FLAPsense technology and the Constance wireless data transfer, can be applied to other rotary or propeller aircraft.
The contactless sensing potentially has large benefits for reliability and maintenance as far as it enables more accurate measurements on a huge surface area (not only single probes) without impact to the measured object (i.e. no sensor installation on the investigated surface, that could disturb the flow) or by the measured object (i.e. no mechanical linkage that would cause unwanted coupling of several degrees of freedom).
Additionally, the different sensor concepts and lessons learnt from the system design can be used for further applications on rotor or propeller deformation measurement systems. The capabilities gained on structural analyses, heat exchange calculations and investigations on EMC and HIRF protection are valuable for future airborne sensor developments.
The real time marker detection algorithm can be used for other position, shape and deformation measurements, where the results are required directly during the running test. Presently such results are only available after the later performed postprocessing. It has to be mentioned, that the first application of the fiducial markers for highly accurate measurements that was done in FLAPsense now is pushing their development further and could improve the automatic marker processing also for other optical measurement techniques were presently a certain amount of manual marker detection is included.
The lessons learnt for the 3D printing of the enclosure can be used for future rapid prototyping actions and the software algorithms for the trigger evaluation and the ARINC data conversation can be used for next applications where a robust additional method for the RPM determination for avionics is wanted. The method can directly be implemented in the flapping sensor, avoiding additional RPM or azimuth sensor systems. Alternatively, the novel sensor system can be used as an additional one in order to increase redundancy.
Due to the fact, that the FLAPsense sensor concept is very promising and most of the extensive work for this test still has been done, i.e. design and manufacturing of the Marty test rig, planning of the test, design and manufacturing of the preliminary model of the sensor system (= the research demo sensor system), it has been agreed to perform this demonstration test after the end of the project at on own costs and risk. Results of this Demo-Test will be used for further maturation of the system and realization of the CDR sensor design.
With regards to the exploitation the achievements made within the FLAPsense project have valuable potential for other future applications. In general, the FLAPsense technology and the Constance wireless data transfer, can be applied to other rotary or propeller aircraft.
The contactless sensing potentially has large benefits for reliability and maintenance as far as it enables more accurate measurements on a huge surface area (not only single probes) without impact to the measured object (i.e. no sensor installation on the investigated surface, that could disturb the flow) or by the measured object (i.e. no mechanical linkage that would cause unwanted coupling of several degrees of freedom).
Additionally, the different sensor concepts and lessons learnt from the system design can be used for further applications on rotor or propeller deformation measurement systems. The capabilities gained on structural analyses, heat exchange calculations and investigations on EMC and HIRF protection are valuable for future airborne sensor developments.
The real time marker detection algorithm can be used for other position, shape and deformation measurements, where the results are required directly during the running test. Presently such results are only available after the later performed postprocessing. It has to be mentioned, that the first application of the fiducial markers for highly accurate measurements that was done in FLAPsense now is pushing their development further and could improve the automatic marker processing also for other optical measurement techniques were presently a certain amount of manual marker detection is included.
The lessons learnt for the 3D printing of the enclosure can be used for future rapid prototyping actions and the software algorithms for the trigger evaluation and the ARINC data conversation can be used for next applications where a robust additional method for the RPM determination for avionics is wanted. The method can directly be implemented in the flapping sensor, avoiding additional RPM or azimuth sensor systems. Alternatively, the novel sensor system can be used as an additional one in order to increase redundancy.
After the successful completion of the FLAPsense project, a novel airborne contactless measurement system will be available that enables real time tilt measurements in a rotating environment. Besides the integration of the FLAPsense sensor in a rotor hub, other application examples of the sensor system and the associated developments (real time deformation measurements, rotating image acquisition) might be the investigation of airframe structures and control surfaces during flight, the monitoring of wind turbines or even the measurements of the behaviour of wheels and tires during road testing.