ARGOS - Automatic Rotor blade Ground-based Observation System

The ARGOS, the measuring platform for future-oriented inspection in line with Industry 4.0.

With the granting of planning permission for a Wind Energy Plant (WEP), its regular inspection also becomes due. As a rule, every two years.
For rotor blades, as a minimum, “visual examination” and the checking of the lightning protection system are mandatory. The certifying body (usually DNV-GL) also recommends the documentation of damage and the “sounding out” of anomalies”.
In particular, through the transition of the “operator model” away from individual people or small limited partnerships to Utility Companies (UCs) and internationally active operating companies, a great demand for good, high-quality inspection facilities has developed over the last ten years.
Alone in Germany, several dozen companies, from “two-man businesses” right up to internationally active companies with considerably more than 100 employees, are dividing up the market amongst themselves. With all companies, the approach to the inspection of rotor blades is virtually the same.
The focus is on the head for heights of the personnel as the “accessibility” takes place by means of rope climbing, a self-propelled platform, a boom lift or a crane-assisted man cage.

Qualification in the field of glass fibre reinforced plastics (GFRP) or carbon-fibre reinforced plastics (CFRP) is of secondary importance. The employees work, metre by metre, from the nacelle towards the rotor blade tip. On a 3 MW wind turbine, the rotor blades are at least 60 metres long and cover more than 300 square metres. For a system such as this, purely visual inspection with photographs of local complaints requires a three-man team (two men on the rope and one for safeguarding), on average for two working days each of 8 hours. This means that one employee inspects 25 square metres an hour on average. To this must be added the time for the compilation of the examination results.

Common to all current familiar methods is that they only allow a partial and local inspection of the rotor blade and the examination results must be manually collected and evaluated. Due to the differing positions in the local inspection and the unsynchronized raw data, automation is not possible.

Despite increased quality assurances by the manufacturers, rotor blade breakages have constantly continued to occur in the last few years. All manufacturers, therefore, have a great interest in holistic and cross-discipline inspection in order to be able to preclude serial losses and to be better able to monitor third party suppliers.

More companies are using drones or special telescopes borrowed from astrophysics in order to obtain at least visual, all-embracing “raw data” for the assessment of the rotor blade. But in the end, damage that affects the structural integrity can, in most cases, not be detected.

Using different measurement technology, our ARGOS collects the “raw data” in situ. The necessary evaluations are subsequently carried out by trained specialists (engineers) in the back office that are intended to be assisted by artificial intelligence (AI) in the future. This is only possible due to the uniformity of the raw data.

With such a method, we create the unique opportunity for the customers to obtain a “digital fingerprint” of their rotor blades. The value retention, the insurability and the risk minimization are all strengthened for the operating company.

Today, ARGOS can adaptively accommodate all current as well as future measurement technologies and is, therefore, the basis for the future safe holistic inspection of rotor blades. Due to the fact that the measuring platform is protected by patent law in Europe and also in the USA, over the next few years there will be no competition worth mentioning for this system.

Briefly: With ARGOS, we have developed a worldwide patented system for the automated inspection of rotor blades. We combine digitalized measurement data with a holistic data base and can, using our mobile Condition Monitoring System (CMS), recognize and document structural damage to rotor blades at an early stage.

In addition to the use of high-resolution cameras for the complete visual recording of the surface and the 3D measurement of the blade geometry, we place great emphasis on active infrared thermal imaging and ultrasound technology in order to non-destructively examine fibre reinforced composite plastics. A complete system, flexibly deployed, allows shorter assembly times and an extraordinary inspection procedure for the complete blade.

Evaluation and Storage

Audit-compliant storage
Data evaluation
Preparation of inspection reports and expert assessments
Long-term tracking of the measurement results

Ground-based Data Collection

Digital photographs
3D data
Infrared images
Ultrasound scans

In comparison with conventional inspection methods, such as working from rope or a measuring platform, and more innovative methods, such as inspections by drone, ARGOS has the following advantages:

Holistic inspection of the complete blade, not just locally as with conventional inspection methods, that generates a comprehensive data pool.
The inspection outputs can be repeated as often as required and with the same quality and thus create the digital fingerprint (3D) of a rotor blade with chronological dependence.
AI automatically recognizes pre-defined faults and marks the affected places on the rotor blade.
With conventional inspection methods, a maximum of one installation per day is realistic, with the ARGOS travel speed of 10 m/min, two installations per day are achievable.
With two people, the operation of the ARGOS is an extremely good manpower saving. The operating personnel are not exposed to any danger whatsoever that arises from rope access technology or measuring platform.

Comparison with conventional inspection methods, for example, 3 MW installation (100 metre hub diameter)

	Abseiling Techniques	Platforms	Drones	ARGOS
WEP downtime	10-15 h	8-10 h	1 h	2-3 h
WEP inspections per day	Max. 1 installation	Max. 1 installation	3-4 installations	1-2 installations
Risk for the engineers	Very high	High	None	None
Level of detail	Medium	Medium	Low	High
Repeat accuracy	Low	Low	Low	High
Data processing effort	Very high	High	Medium	Low

Technology	Abseiling Techniques	Platforms	Drones	ARGOS
Visual inspection	+	+	+	+
Tap test	+	+	-	-
Digital photography	+	+	+	+
3D imaging	-	-	-	+
3D scan / measurement	-	-	-	+
Ultrasound	Local	Local	-	Global
Infrared, passive	Local	Local	+	Global
Infrared, active	-	Local	-	Global
CT / X-ray	-	-	-	2021/2022
Inspection in accordance with DNVGL-ST-0376	+	+	-	+
Data acquisition	Manual	Manual	SQL server	SQL server

Our business models

We measure for you, evaluate the data, and you receive meaningful results.
Furthermore, you can lease the ARGOS and operate it yourself.
Back office: You carry out the measurement work using a purchased or leased ARGOS, give us the raw data and we evaluate them for you.
We are happy to sell the complete package to our customers. This means we supply the framework structure, the measurement technology, instruction in the operation of the ARGOS, the evaluation software and instruction in the application of the software.

Tel.:	+49 (0) 385 59 38 36 50
Fax:	+49 (0) 385 59 38 36 49
kontakt@composite-consult.de