老龄化问题的基础设施和过时的有限公司mponents are bad enough, but what if you’re running a nuclear power generating facility? Lloyd Pentecost, maintenance engineering supervisor at the San Onofre (Calif.) Nuclear Generating Station (SONGS) recently encountered these problems squarely in the face. The plant, owned by California Edison, and located between San Diego and Los Angeles, was built in response to the 1973 oil crisis and went online around 1983.
近年来,五旬节最大的直接支持blem lay in the plant’s 24 4kV motors. The motors are spread throughout the plant, creating a problem for maintenance personnel. In addition, Pentecost lacked the kind of information needed to justify motor upgrades. Because of the geographic spread of the motors, maintenance technicians did routine and preventative maintenance on a schedule rather than waiting until work was needed, causing unnecessary downtime. If only he had the kind of real-time information on the motors, complemented with trending, that would tell him when to do the work and when the motors required major upgrade.
First, fix this
As author Robert Pirsig says in “Zen and the Art of Motorcycle Maintenance,” sometimes there is an intermediate problem that must be solved before the original problem can be addressed. Failure to recognize that has caused much grief. In Pentecost’s situation, the intermediate problem was the cost of wiring in his plant. A nuclear power structure has thick, reinforced concrete. He estimates the cost of wiring at over $1,000 per foot. So the problem was how to get data from sensors on each motor back to a central computer.
One of the hot topics in networking is wireless Ethernet using the IEEE 802.11 standard promulgated by the Institute of Electrical and Electronics Engineers—popularly called WiFi (for wireless fidelity). Pentecost and his team decided to implement this wireless solution in order to get around the cost of wiring. “We had some motor problems,” relates Pentecost, “so I had some wireless modems installed and we put in a WiFi system. But the cost for this was exceedingly high. We also joked about how we just need 32 bytes of information every four hours, yet we put in a system capable of 10 megabits per second. That just didn’t look like an appropriate solution.”
Pentecost presented a paper on his WiFi system in 2002 describing how it works and the payback it provided. But he said he was looking for something better. “Some ZigBee guys came up to me after the session and each said they were looking for a partner where they could put in a system and gain experience and exposure,” says Pentecost. ZigBee is a wireless networking standard based on IEEE 802.15.4. It is a low-power, sensor-based network with a mesh topology.
He started evaluating systems in April 2004, figured out what direction to go in May and was ready to start buying for a pilot installation by August. He had assembled systems to test vendors’ solutions. Some products didn’t work up to his expectations and others were too hard to install. He settled on technology from Sensicast, a Needham, Mass., developer of ZigBee components, in part because he found its solution easier to install and in part because the company was able to implement a ZigBee solution in a resistance temperature detector (RTD) sensor that SONGS uses to monitor motor health.
“I wouldn’t be doing it if I didn’t think there’s a future to this technology,” states Pentecost. “Now, I’ll start looking for ZigBee in other sensors, say, pressure for instance. This seems like something that will really change factory floors.”
Filling a database
Meanwhile, a company in another type of industry had trouble getting information into a database so that real-time decisions could be made. Knauf Insulation is a U.S. manufacturer of thermal and acoustical fiberglass insulations for residential, commercial, industrial, marine and original equipment manufacturer applications. The company’s products include fiberglass pipe insulation, insulation board, duct wrap, and pipe and tank insulation.
As part of its operations in Shelbyville, Ind., Knauf had three fiberglass production lines that utilized gauging systems to measure the density of the product during the manufacturing process. Accurate density measurements are critical in the manufacturing of many different types of materials, including fiberglass. As Curtis Davies, an engineer with the Corporate Process Engineering Division of Knauf Insulation, explains, “We have very rigorous quality assurance standards. Any deviations from specifications on any of our products have the potential to result in the necessity to scrap that product.” And that’s not to mention the wasted man hours involved, Davies adds.
Nuclear-based gauging systems have been developed to perform the required density measurements. These systems apply a radioactive energy source to products such as fiberglass while special receivers measure how much radiation gets through. By determining how much energy the product absorbs, a very accurate density measurement is acquired.
Knauf wanted to import this measurement data into a Microsoft SQL Server database to build production profiles for analysis, archiving and optimization. The company also needed the data to make automatic real-time adjustments to its manufacturing processes.
Unfortunately, the gauging systems used by Knauf at its Shelbyville facility couldn’t communicate the data to Knauf’s Microsoft SQL databases without some complex engineering. Knauf, it seemed, was going to have to enlist software consultants to develop a custom application that would enable the hardware to communicate with SQL Server. And to make matters worse, the cost for this adaptation was most likely going to be very expensive.
Automated Interface Solutions (AIS), a division of Industrial Maintenance Engineering Inc., Terre Haute, Ind., stepped in and assured Knauf that its needs and expectations for a new control system to reach its goals were both realistic and affordable. AIS recommended removing the then current control system hardware in favor of a more open and less expensive solution using Snap I/O (input/output) provided by Opto 22, Temecula, Calif.
AIS提出其解决方案作为一个便宜,open architecture alternative to the incumbent system and initiated a pilot project for Knauf on one of its three Shelbyville lines. In just a few months, the customer was sold, and ordered an additional upgrade for Shelbyville, along with a full system purchase for its facility in Lanett, Ala.
“The open architecture was key,” says Young. “The platforms we design for customers must permit easy plant-wide integration and must also allow for component upgrades so that as technology advances, the systems won’t become obsolete.”
In addition to Knauf’s gauging system sensors and actuators, AIS has also been successful in integrating the Snap I/O hardware with various on-line x-ray, infrared, caliper, temperature, proximity and moisture sensors used in other processes relating to sheet-good manufacturing.
Machine-to-machine
Can you hear me now? This familiar line from a cellular telephone advertisement strikes a chord with every user trying to find a spot to get good voice reception. But what about when a machine dials up a computer to access a database over a cellular connection? This process is now called M2M, for machine-to-machine communication. This process is actually working for a manufacturer and distributor of industrial water treatment services.
Rich McLeod is director of global commercial development for BioLab Water Additives, in the Lawrenceville, Ga., division of the Manchester, U.K., company. “Our customers are anyone who uses water for utilities, whether refineries, pharmaceutical, food and beverage manufacturers, or even for the heating, ventilating and air conditioning systems for buildings. We provide chemicals for treatment and provide a service technician to periodically check the system.”
One problem BioLab faces is that most of the representatives have many customers spread out over a large geographic area, McLeod explains. Frequency of a visit may vary from weekly to monthly. Should a problem arise between visits, it could be neglected and fester. As a result, what the company needed was a way to improve its service by monitoring the system more often, while at the same time increasing the efficiency of its field representatives, he says.
BioLab developed such a service that views customers’ systems all the time and will set an alarm and notify a human whenever needed. It calls the service Onsight. The system consists of a small control panel with I/O connections, a small controller and communication port. Communications can be via a local area network (LAN), plain old telephone service (POTS) or cellular service. BioLab considers the latter option the most convenient and lowest cost solution. Sensors from the water solution are connected to the control panel’s I/O. Once per hour, the controller automatically connects to the Chicago data center of nPhase Corp., a pioneer in the emerging M2M market.
WiFi to go
Companies such as BioLab are exploiting cellular communications for remote data acquisition, but there are limitations and restrictions. It is not part of the ubiquitous Internet protocol (IP) universe. What if you could send IP over the cellular network? This would be like WiFi, which has a limited coverage area, on steroids.
Chris Gilbert, president and chief executive officer of IPWireless, San Bruno, Calif., believes his company has found a way. “We make equipment for licensed carriers to put into networks and devices,” Gilbert relates. “It is, in effect, WiFi, with a speed similar to it but reaches a larger geography. It can replace DSL [Digital Subscriber Line] for broadband connectivity in homes.”
The company has been shipping its solution for about two years and is finding some worldwide attention. Gilbert reports that a Web developer in New Zealand uses it to demonstrate his work, regardless of where the nearest Ethernet connection might be. Also in New Zealand, a wine distributor has set up 40-inch LCD displays at retailers in order to push up-to-date point-of-sale information. A commuter railway is installing access points in carriages so that riders can connect their laptops to the Internet during their commute.
