The mechanics are based on a clamp that can be mounted directly onto the pipeline by a ROV.
The electronics pod is then mounted on top, using a locking mechanism that allows for later
removal for battery replacement.
The pod is water tight and designed for sea depths up to 1500m (150bar). It contains
electronics, batteries, sensors and antennas.
Figure 5: Internals of the pod are decoupled from pipeline vibrations to reduce stress.
The NAXYS view
Naxys is part of the Norwegian company group Bjrge as, and is specialised in sub sea
instrumentation and condition monitoring of sub sea installation, using hydro acoustics and
other non-contact sensor technology. Due to the high demands on our systems, Naxys is
frequently developing electronics and software for our products.
However, the short schedule on this project, required us to find a well proven hardware platform, and a corresponding programming tool, yielding the shortest possible implementation time. Focus was also put on efficient debugging and system testing.
The requirements for the hardware and software system to be used on this application, were not met by many, as the challenges of Naxys, was to find a platform and software system that:
-Is small in size and can be operated in harsh environments and has a low, controllable and deterministic power consumption. It also had to be programmed in both C and LabVIEW, handling parallel program loops
A s deterministic program execution time and computational power to perform Fourier analysis on hundreds of kb of data were key, along with having multiple analog channels with simultaneous sampling and multiple serial I/O channels. Digital I/O and connectivity to a test board for 100% accurate system simulation were also design concerns.
After thorough market research, we ended up with the Analog Devices Blackfin Processor. It is no secret that this application has pushed LabVIEW Embedded to its very limit, but both LabVIEW and VDK has passed. The skillful engineers of Schmid Engineering created drivers and libraries to be used directly in our LabVIEW environment, saving us valuable time, and also provided the required system stability.
This project is so far a success, and Naxys expects to use the highly versatile system of
ZMobile and LabVIEW Embedded in a wide range of our sub sea acoustics and condition
Photos courtesy of NAXYS and Schmid Engineering.
About the authors
Harald Manum is a senior engineer at NAXYS and Marco Schmid is a senior engineer at Schmid Engineering AG