On-Board critical frequency detection for aircraft, deployed as a standalone real-time app on the Curtiss-Wright MAT101 microprocessor module

Critical Materials have developed firmware for the MAT101 Microcontroller to detect narrow band frequency harmonics using FFT techniques and generate appropriate alarms to the test pilot and pre-processed data to the flight engineer.


Getting the right information from the aircraft in real-time during flight is something that flight engineers and pilot’s want. A system that helps to minimise the effort of the flight engineer when analysing hundreds of signals, or provides real-time information to the pilot about exceedances would provide significant benefits in flight test. To make this possible it is necessary to have a rugged data processing hardware running advanced signal processing algorithms with feature extraction in real time. This was the challenge from our customer, a major Flight Test organisation.


We have used the MAT101 Microcontroller module, which is certified and able to be programmed using C language. It has a multiprocessor architecture with a digital signal processor. Critical Materials developed firmware to run on the MAT101 able to detect narrow band harmonic content, using advanced signal processing.

Using techniques such as narrow band FFT, we are able to check the existence of an harmonic with a configurable maximum amplitude. Every time the amplitude of the harmonic exceedes the programmable threshold inside the frequency band of interest, the alarm state is updated. It is possible to view the harmonic amplitude, its frequency and the alarm state with a trivial RS232 serial console. A TTL digital output states an alarm event. The signal processing is done in real-time with minimum latency using the FFT capabilities of the hardware to implement complex filtering and feature extraction. The solution is completely integrated and compatible with all the tools of Curtiss-Wright for the KAM500 airborne data acquisition unit.
The output variables can be logged and stored on local memory cards using a recorder. The firmware is able to process up to 8 analogue inputs simultaneously with 8192 samples per second each


Developed a real-time frequency detection firmware for the Curtiss-Wright MAT101 module that is certified to fly.

EDP renewables onshore wind blade SHM monitoring

EDP renewables is working with Critical Materials at its wind energy production site of El Pédron, located in the province of Leon, Spain. This project gives EDPR a

better insight on how material properties of its wind blades change over time. The turbines that are moved by these blades have a nominal power of 2 MW and are subject to the kind of harshness typical of a mountainous environment. At around 1500 m altitude, lightning strikes and ice formation on blades are a few of the stresses blades have to endure. Also the thermal amplitude, high humidity and wind load on the blades all account for the potential decrease of its lifetime.

In a partnership with Fiber Sensing, which provided the fiber sensors, interrogators and their instalation, Critical Materials has deployed a PRODDIA W control station based in Portugal that integrates all data gathered at the site and produces periodic structural heath management reports for the operations and maintenance teams in Portugal and Spain.

All blades are instrumented with optical strain sensors and data is continuously gathered at a rate of 100 samples per second. With this, Critical Materials proprietary algorithm is capable of detection stifness loss (either from cracks or delamination of composites) and mass increase. The employed methods are model based and an in depth analysis has been performed with blade models; a sensor minimization procedure has been caried out in order to decrease instalation costs and decrease information entropy. Still, raw data from the data acquisition system can accessed and further explored with the use of an advanced statistical and signal analysis toolkit.

The new monitoring solution, developed by Critical, provides early alerts to the EDP team of any potential problems on the wind farm so they can be sorted out without causing any major disruption or severe damage. EDPR and their clients will also benefit through advanced O&M planning, higher availability with a reduced life-cycle cost.

PRODDIA® W platform ensures that the facility can be operated efficiently and proactively, with minimal human intervention. PRODDIA® W is a structural system health management platform that combines readings from any sensing technology and advanced algorithms to assess the structural integrity, performing damage diagnosis and prognosis (D&P).

Critical Materials teams with Curtiss-Wright to develop a Structural Health Monitoring program for the Portuguese Air Force

Critical Materials has been providing the aerospace industry with Structural Health Monitoring (SHM) software since 2008. Our SHM framework, PRODDIA TM, Portuguese Air Forceprovides increased asset availability and extended lifetime while reducing operations and maintenance expenditure. PRODDIA AERO, developed specifically for the aerospace community, combines simulated data with physical data to provide customers with patented diagnosis and prognosis technology.

Curtiss Wright

In 2012 Critical Materials approached PoAF with an all in one SHM solution that included PRODDIA Aero and Curtiss-Wright data acquisition hardware. PoAF accepted this proposal as a proof of concept program and dubbed it SHERLOC.

To date, one aircraft is instrumented. The program will run until September 2014; the plan is to develop and gain experience with the data collected and if the results prove useful the some selected aircrafts of PoAF will be instrumented.


Critical Materials found that the best solution for this application was to use a multi-purpose recorder, the SSR/CHS/001 (from the Curtiss-Wright SSR-500 range of multi-role recorders), with a six channel accelerometer module. A benefit of using the accelerometer module is that Critical Materials can read six acceleration channels and two temperature channels on the same module because the module has two DC analogical ports available. By using a signal converter for the PT100 sensor, they can obtain all necessary measurements from the six accelerometers and the two temperature sensors, that are located on two different panels inside the aircraft, with a single module; leaving the three remaining user slots available to add system functionality in the future.

The recorder is located in the cockpit of the aircraft where the pilot has control of start, stop and event recording functions from the front panel. The pilot has been instructed to start recording upon entering the aircraft and to use the event button when they are attempting a non-conventional maneuver. This enables more efficient data analysis with the ability to pinpoint specific times in which events of interest occurred that need further analysis.

PoAF removes the Compact Flash card from the front panel of the device weekly, and uploads the operational data to their servers. Because the SSR-500 records data in the open source PCAP (packet capture) format, Critical Materials has developed a converter that converts the PCAP file to database files that PRODDIA Aero can read. Each channel of data and each mission is converted into its own database. By combining structural finite element modeling with real data, PRODDIA Aero can output a 3D structural condition map of the monitored components. Dynamic data is used for the evaluation of structural integrity because it is more sensitive to structural variations. Therefore each time an assessment is made, a different frequency response spectrum signature is obtained. With the SHM algorithms developed by Critical Materials, PRODDIA Aero will be able to detect, localize and asses the condition for each monitored structural component.


A future proof, expandable data acquisition and recording solution used for structural health monitoring of military aircrafts.

Offshore energy from POSEIDON

Poseidon is a concept from Floating Power Plant, Denmark, for an integrated floating power plant that transforms wave and wind energy into electricity in-situ. The wave energy plant serves as a floating foundation for offshore wind turbines, thus creating a sustainable energy hybrid. The P37 is an offshore demonstration plant, 37 m wide, launched in 2008 and being tested in the North Sea, off the coast of Lolland in Denmark. Critical Materials (PT), Critical Software (PT) and Critical Software Technologies (UK) worked with FPP to support the company in adopting a proactive approach to control and monitoring its P37 offshore plant.

An unprecedented level of Integrated Condition Monitoring was achieved by integrating csEMS and PRODDIA IS software codes, ensuring that the facility can be operated efficiently and proactively, with minimal human intervention. csEMS is a software system that provides state of the art O&M tools for companies that manage energy producing plants, enabling the monitoring, management and reporting on the entire portfolio of assets, regardless of location, technology or equipment brand used. PRODDIA® IS is a structural system health management platform that combines readings from any sensing technology and advanced algorithms to assess the structural integrity, performing damage diagnosis and prognosis (D&P). The new monitoring and command and control solutions, developed by Critical, provides early alerts to the Poseidon team of any potential problems on the plant so they can be resolved before causing any severe disruption or damage. FPP and their clients will also benefit through advanced O&M planning, higher availability with a reduced life-cycle cost.

Operation, maintenance and survivability are key issues when working offshore. It is essential for FPP that during our technology development we continuously focus on improving O&M. FPP has therefore chosen to collaborate with Critical on the third offshore test phase, with the goal of developing and testing a more proactive O&M strategy”, says CEO Anders Køhler of FPP. Critical Materials S.A deployed diagnosis methods for the wind turbine blades and tower, the buoy-structure interface and the anchor chain system, integrating them into PRODDIA® IS. Critical Materials S.A. developed significant experience in Structural Health Monitoring applications through its extensive work in the Aerospace and Energy industries.