GPS and barcode pipe data collection
Ellipse Spatial Services Ltd.
#409 918-16 th Ave N.W.
Barcodes have been used in the retail industry for years for inventory control and to identify products at the counter. Barcode technology has been used successfully on a number of pipeline projects to track and identify pipe from the pipe mill to the ditch during pipeline construction projects ranging in size from 10 to 42 inches. Not only is it an efficient method of data collection, but also in conjunction with GPS it provides a means of quality assured asbuilt data.
Barcodes are placed on the individual joints of pipe at the coating facility via label or ink jetting the information onto the pipe’s surface. The barcode contains the identification information for each joint of pipe that can be utilized at any point during construction such as the stockpile yard, stringing, welding or lowering-in. The individual pipe information is collected via barcodes and handheld computers, including weld numbers and pertinent information that may want to be collected. Once the pipe data is collected, GPS is used to collect positions of the pipes features in the ditch and other occurrences such as crossings. Daily reporting of pipe data occurs for resolution of construction and welding process problems with this quality assured digital information. The data is easily uploaded to a GIS environment for use during the operation of the pipeline.
Barcode technology has been used in many industries successfully for years for inventory control and materials tracking. During the construction phase of a pipeline barcodes can be used to identify individual joints of pipe, and allow for quick easy data collection in a non-spatial or spatial setting. With the requirements for improved pipeline data for pipeline integrity throughout the life cycle of pipeline, barcodes are able to provide a simple, quality controlled and dependable method of pipe data collection in the field. The use of barcodes to collect pipe data creates a seamless process of transferring data from the field to an office setting. Not only is this process seamless, but it is also a means of quick and accurate data collection by field crews equipped with GPS, barcode scanning equipment and any other variety of conventional data collection tools. The field crew is able to obtain a GPS position of pipe features that can be linked to or captured with the scanned barcode data. The electronic pipe data captured in the field is then quality assured against the digital mill manifests for abnormalities or identification number errors. The mill manifests maybe used within a handheld computer for quality assurance “on the fly” as pipe data is being collected or can quality assured when the data is post processed. The data then is exported to a database, or GIS for asbuilt plan generation.
Pipe indentification historically
Traditionally pipe joints are assigned unique identification numbers (pipe numbers, heat or coil numbers) at manufacturing mill. They are manually issued at the start of the milling process, and the numbers identify each joint of pipe from production at the mill to the asbuilt survey on the right-of-way. In short each joint of pipe is unique identifier numbers that are used throughout the pipelines life span.
At the end pipe mill process, the pipe identification numbers maybe placed on the inside or the outside of the pipe joints. Upon arrival at the end of the coating process the pipe numbers are recorded to a tally sheet, and reapplied manually to the outside or inside of the pipe. Human transposition errors may occur during this process, of assigning and transferring of pipe identification numbers.
The pipe joints are then transported to stockpile sites were a tally of the joints is performed. This tally is based on the pipe identification numbers. The pipe is then strung along the right-of-way for welding and placement into the ditch. After the joints of pipe pass through the welding process the order and identification of each joint is collected manually in field. Again human transposition errors may occur during this process, of assigning and transferring of pipe identification numbers. This information is then later converted to electronic format, for use in a database, electronic drawing generation and GIS applications.
This process works well for the most part and the end result is acceptable, but there are some areas in which this process can be improved. The first is the quality of the information collected and the second is the cost of collecting this data. The present quality of the information is not generally questioned, partly because it is not easy to do so and perhaps because it may cause problems if the true accuracy of the data were known. In discussions with various people who transfer and collect the pipe data, it is suggested that the entire manual recording of the data create errors of 15- 20%. Although not conclusive, a manual ad hoc test resulted in >20% error rate for pipe data collection. If these errors were truly known, then new procedures and quality control checks would be required, affecting pipeline integrity and operation issues. The second area that barcode technology assists is in lowering costs then any savings in the process will benefit the pipeline companies. These savings include the manufacturing, coating, construction, and final preparation costs.
Dependability of barcodes for pipe data
The pipe-coating manufacturer applies the barcode label or inkjets the barcode directly onto the surface of the pipe at the end of the coating process. If the barcode is to be printed directly on to the surface of the pipe, the barcode will be less susceptible to damage during transportation of the pipe to the right-of-way for construction. If the bar code is printed onto a label, the barcode symbology must be able withstand damage during handling and transportation. The resilient combination of barcode symbology and labels has historically shown less than a 3% fatality rate. At this low fatality rate, even a joint of pipe with a damaged label is not untraceable, as multiple labels and the conventional stenciling can be utilized.
Barcodes on pipe must be able to survive handling from stock pipeline yards to trucks, rail cars and stringing along the right of way, and thru the welding process. This dependability of barcodes are based on three factors:
Application of labels to the pipes surface at the coating facility requires an adhesive that will not damage the coating and must be able to withstand handling to the right of way without the label being removed. Labels that are of a film like material provide the best resistance to physical damage with an adhesive that will survive high temperatures of the pipe at the end of the coating process and high ambient temperatures and humidity of the environment. Thermal printed labels have proven to be the most durable with very little smearing of the barcode.
Ink jetting of the labels on to the surface of the pipe provides the best alternative if the coating facility is equipped to do so. The ink-jetted label is printed in a spiral down the axis of the length of pipe.
The selection of barcode symbology
Barcode symbology will determine the amount of information that can be stored within a barcode and the physical damage that it will be able to with stand and still be readable. One-dimensional barcodes can only store a small amount of information and are not resistant to physical damage the vertical axis. This barcode technology is the most commonly used in a variety of industries and is of very low cost to implement.
Two-dimensional barcodes are capable of holding approximately 2000 alphanumeric characters and are able to provide readability even if the label is damaged 50%. This symbology is more expensive to implement, as the scanning and printing equipment is more intelligent than the one dimensional barcode equipment. The amount of information the two-dimensional barcode can contain may also cause complications with the amount of memory within handheld computers and may take a minuet amount of extra time to collect.
Placement of labels
The placement of the barcodes labels is very important because if they are placed on the pipe joints incorrectly they can be damaged when being handled on to rail cars and trucks, and they must be visible for data collection. Large inch pipe may require labels to be placed in multiple positions around the circumference of the pipe, while smaller diameter pipe may only need a couple of labels at one end. It is important to be aware of the specification that was supplied to the mainline contractor, dictating the length of pipe that will overhang the bunks or separators of rail cars and truck trailers.
Content of the barcode may very to the client’s requirements, and whether one or two-dimensional barcodes are being used. The barcodes must also be humanly readable so that a person not equipped with scanning equipment is able the use the information printed on the barcode. Generally they may contain, but are not limited to any of the following:
A variety of methods can be used in conjunction with barcodes and GPS to collect pipe data and asbuilt information. These approached may be very simple to complex depending on the client’s requirements for the asbuilt information, as this information may be captured in a non-spatial or spatial environment. Handheld computers may be used to collect the pipe information in a non-spatial format. The data collected is the pipe identification information and weld numbers in order as the pipe joints were welded.
The GPS spatial data includes the coordinates and elevation of a pipe joint feature and the barcode pipe data. The GPS and barcode data create a three-dimensional model of the pipe profile. There are 5 basic processes of pipe data collection in the field:
The pipe information is validated against the pipe mill manifest to insure that it is correct before it is welded together. If needed, the internal pipe and heat number can be transferred to the outside of the pipe, or a barcode label can be applied for later use after welding.
Barcode pipe data collection.
Following the mainline welding crew, all pipe features of the welded mainline and drag sections are collected, including but not limited to:
The pipe’s features are collected behind lowering-in with GPS receivers or optical total stations to produce a model of the pipeline. At this time further descriptive data can be collected such as:
Similar to capturing the lowering-in data, tie-in data positions the pipe in the ditch, connect mainline and drag sections together to complete the pipeline model.
Pups removed from a section of pipe at a tie-in, can prove to be a challenge to track. A pup may be used in more than one tie-in, so it may have to be remarked if the barcodes are not present. The simplest and most effective way to do this is with a felt pen. The pipe identification numbers are marked on the surface of the pipe for later use.
Data processing and quality assurance
Once the GPS data is processed, it is imported into a database that is used to store, compare and perform quality control checks on the data. This process happens nearly in a real time fashion. Data that is collected later during construction, such as tie-in data is then added to fill in the holes within the data model. There are a few data sets that are collected during the asbuilt portion of construction that are then compared against each other as a method of quality control. All of the data that is collected is then compared to a digital mill certificate or tally count from the coating supplier. Not only does this process provide data that is of high quality, but is also the data is traceable. The data is then exported into a format the client can utilize.
The cost of this data collection process is rather insignificant compared to traditional data collection methods. The cost of labels or insetting the barcode on to the pipe is very cheap, and is becoming a normal occurrence. The manpower to collect the data is already put into place on larger diameter pipe. Benefits include: