Data Acquisition and Logging Gets on Track

Modern Data Acquisition Equipment Is Useful, Friendly and Inexpensive. You Can Use It Anywhere--Even in a Race Car

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"Tightly integrated hardware-software solutions are inherently more flexible than stand-alone systems," says Charlie Stiernberg, product marketing manager for remote data acquisition, at National Instruments. He says "retaskable" DAQ systems allow users to move a system from job to job without spending more money.

"In some cases, companies are testing for A and then B without having to buy any additional equipment. National Instruments customers, for example, can use the same C Series modules for measurement, control and datalogging applications over Ethernet, wireless or USB connections without changing their software," Stiernberg says.

EUtech Scientific Engineering in Germany used NI's hardware-software solution to build the EUcoalsizer system, a mobile DAQ and laser probe that measures coal particles in coal pipes. Instead of collecting samples from the coal pipe and taking them to a laboratory for analysis, EUcoalsizer does the measurement and analysis onsite. This helps EUtech's utility customers optimize coal combustion efficiency and lessen the effects of coal burning on the environment by reducing greenhouse gases such as nitrous oxide and carbon dioxide.

Max Starke, development engineer at EUtech, says, "We simplified and improved a formerly expensive and labor-intensive coal particle measurement process by using National Instruments' high-speed digitizers, multifunction DAQ devices and LabVIEW software." For more details on how EUcoalsizer works, see the sidebar "DAQ in the Stack."

Similar DAQ systems are available from a host of vendors to address everything from general-purpose to very specific applications. So, if you can't find one that meets your exact needs, you can always build one yourself from available hardware and software.

Rich Merritt is a Control contributing editor.


Racecar DAQ

Racing great Mark Donohue called it "the unfair advantage." Rally racers in the U.K. call it "demon tweaks." In NASCAR, it's "getting the call." Whatever you call it, finding little secrets to make your car go just a teeny bit faster than everyone else's is what wins championships and sets records.

That's what Trevor Stripling did with his car: He found a way to use data acquisition to get the data he needs to tune his car to the ultimate, much like a process control engineer uses adaptive tuning and process optimization techniques. Essentially, Stripling gathers important data during a "batch run," analyzes it, compares it to previous runs and tunes the car accordingly, in the hope of finding "the golden batch."

DirectLogic DL06 series PLC
Figure 3. DirectLogic DL06 series PLC

A DirectLogic DL06 series PLC (Figure 3) captures data from oil pressure,fuel pressure, engine vacuum, engine temperature, voltage, nitrous pressure, wideband O2, and engine and driveshaft RPM sensors during the five second drag strip run. All real-time functions of the car are handled by the PLC, including ignition timing.

"The most important engine parameters are the wideband O2 sensors," Stripling says. "They tell us how efficient the nitrous tune is for the given weather conditions.The second would be the engine and drive-shaft RPM; these tell us how the suspension settings are responding to the engine power and track conditions."

The PLC connects to Maple Systems' Ivory Series HMI with Windows CE, running Indusoft WebStudio HMI/SCADA software (Figure 4). The PLC and HMI connect via standard Ethernet. "One of the benefits of the HMI is that I was able to move some of mathematical conversions for the analog sensors to the HMI, which has decreased the scan time in the PLC, allowing it to respond quicker and make real-time control decisions," says Stripling.

Indusoft Web Studio HMI software displays
Figure 4. Indusoft Web Studio HMI software displays data and downloads engine tunes to the PLC. 
(Courtesy of Scott Singleton for RPM magazine)

HMI displays are used to tune the car before each run and to log and save settings after each run. "I can view and change any of the tune-up settings in the PLC and enter in any other manual or physical setting, such as shock settings and tire pressure for the race," he explains. "I've built a ‘recipe' database, as we call it in the control world, that saves these settings for each run.We can easily pull up a prior run and load the tune.  We also use this when we are in line for a run and the track conditions change. At the last minute, we can pull up an alternate tune and load it with a touch of the HMI screen."

Like many process systems, the DAQ system connects to higher-level management software—in this case, a laptop computer in the race car trailer. "We used to have to get the laptop out of the trailer, connect it and download the run data, then convert, analyze and graph it," says Stripling. "With WebStudio's scripting and database connectivity and Maple System's USB communication ports, we now just touch a button on the screen and a script goes out to the PLC, gets all the log data, converts it to engineering units and loads it into a database on a USB thumb drive. We simply take the thumb drive to the trailer and plug it into the laptop where all the run data is analyzed and graphed in Excel. We're currently working on adding a wireless USB card to the HMI so we can wirelessly access the run data."

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