LabVIEW-Based Automated Calibration System Improves Directional Surveying and Navigation Senors

Author(s):
Mike Spalding - Honeywell-Tensor, Rayodyne LLC
Phil Walters - Honeywell-Tensor, Rayodyne LLC

Industry:
Oil and Gas/ Refining/ Chemicals

Products:
LabVIEW,

The Challenge:
Enhancing mission-critical calibration software used in the manufacturing of precise measuring tools for the oil drilling and underground utilities construction industries.

The Solution:
Creating a robust LabVIEW-based automated calibration system encom-passing a flexible modular architecture to connect a wide variety of data acquisition (DAQ) devices and industry-standard relational databases.

Honeywell Tensor Operations is world-renowned for its downhole systems, in which system electronics and hardware "go down the hole" - with a drill bit and subsystems used for directional surveying and navigation. Its focus is designing and manufacturing highly sensitive magnetic survey tools and systems and the software to drive those systems. The Tensor Calibration System (TCS) combines software and hardware to perform calibration on a variety of Honeywell Tensor Operations orientation products. These products can sense their orientation with respect to the XYZ plane using accelerometers and magnetometers and deliver mission-critical data ensuring that the bits actually drill in the appropriate place. Incorrect calibration of this system can cost oil companies tens or hundreds of thousands of dollars in drilling expenditure. Because of the critical nature of the TCS on the production floor, we needed to rewrite the TCS with post-2000 compatible software, operating system, and associated hardware. In addition, the system needed to work with graphical user interface (GUI) technology, a flexible plug-in DAQ architecture, and an enhanced database reporting mechanism. We contracted with Rayodyne, based in Austin, TX (rayodyne.com), to rearchitect the TCS.

TCS Operation
We use the TCS to calibrate analog and digital directional tools manufactured by Honeywell Tensor Operations and our external customers. Therefore, the unit under test (UUT) can be either an analog or a digital directional tool. The type - analog or digital - determines which DAQ instrument we use. These tools can include multiple sensors such as magnetometers, accelerometers, and sensors for temperature, voltage inputs, and current inputs. Third-party DAQ instruments from a variety of vendors, including National Instruments, Keithley, and Agilent Technologies, perform the data acquisition of the analog directional. The TCS can handle a variety of different DAQ instrument interfaces, including GPIB, RS-232, universal serial bus (USB), and TCP/IP via a local network interface board. A proprietary Honeywell Tensor Operations serial interface box through an RS-232 port performs the data acquisition of the digital directional tools.
On each calibration round, the TCS acquires and logs the raw data for all sensors in a directional tool at a fixed temperature. From this raw data, we calculate and log quality and performance parameters to a network database. We enter the performance parameters into a thermal polynomial model. This model generates polynomial coefficients that model the thermal response characteristics of the magnetometer and accelerometer sensors in the directional tool over the temperature range of the tool. These polynomial coefficients are then delivered to customers in the form of reports and files on floppy disks. In the case of digital tools, using in-house software, we store the thermal coefficients in the EEPROMs of the digital tool itself.

LabVIEW Architecture
We chose LabVIEW as the primary development platform for the new TCS because it provides numerous advantages over conventional software development tools. With LabVIEW, we could easily create fully customizable GUIs, connect to relational databases, integrate with disparate types of DAQ hardware, and use instrument-driver frameworks.

In the past, adding a new DAQ instrument to the TCS required a major rewrite of those sections of the code. The pursuit was time-consuming, and sometimes fruitless. The virtual data acquisition instruments (VDAQ) architecture streamlines the process of adding new DAQ instruments and provides a foundation for other Honeywell operations that use similar calibration systems.

Every DAQ instrument requires device-specific code written to conform to the command set of the DAQ instrument. Rather than include this device-specific code in the main body of the data acquisition and analysis (DAA) function of the TCS, it is a separate entity that communicates with the DAA function through a fixed command set. To assist with future VDAQ additions, we developed a VDAQ framework based on industry-standard models for instrument drivers. Using these frameworks or template programs (VIs), Honeywell Tensor Operations internal and external customers can easily develop new VDAQs.

At the core of this architecture lies the VDAQ Director, essentially a resource manager for the entire TCS. When each operator station requests access to a specific test stand and DAQ instrument, the VDAQ Director determines whether the requested equipment is in use and, if not, grants access to it. The VDAQ Director is the only system that requires additional DAQ interface boards. These can include DIO, GPIB, or other. With the use of appropriate adapters, we can accommodate most DAQ interface requirements through the use of an Ethernet interface using TCP/IP.

We divided the TCS application software into modules for data acquisition, analysis, and data storage functions. Central to the TCS application is the DAA application, which acquires the raw data from the analog/digital tool. The thermal analysis application uses this data to generate an Nth order polynomial curve fit. See the diagram below for the overall structure.

Database and Reporting Engine
All calibration data, once acquired, is permanently stored in the database. We used Pervasive SQL 7 as the database engine to provide repository for all data necessary to configure and acquire data from the UUT. It also provides storage for all the raw data acquired and the results of all analyses. We accomplish access to the database using SQL statements through an open database connectivity (ODBC) driver via the LabVIEW Enterprise Toolkit programs (VIs). To present the final analog and digital tool calibration reports, we chose Seagate Crystal Reports Professional 7.0.

Conclusion
With the TCS software update, we have full functionality now and in the future. Because of the open instrument driver architecture approach Rayodyne used in the TCS application, our customers and we can integrate to the very latest networked DAQ technologies with minimal software overhead. Other benefits from the updated TCS include simple 10BaseT, TCP/IP connection to any DAQ instruments; no duplication of plug-in PC boards; operator stations can be desktop PCs with only a network connection; and a comprehensive network-based database for configuration, data acquisition, and analysis.

For more information, contact:

Mike Spalding

Principal Engineer

Honeywell Tensor Operations

1840 Royston Lane

Round Rock, Texas 78664

Tel: (512) 251-4131

Fax (512) 251-5798

E-mail: mike.spalding@honeywell.com

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