Whether bolted into the cab or in the form of a hand-held computer, a record level of computing power is emerging in today's trucks. And while more tools are on the horizon, engineers are looking to c...
Whether bolted into the cab or in the form of a hand-held computer, a record level of computing power is emerging in today’s trucks. And while more tools are on the horizon, engineers are looking to combine systems in equipment that can be upgraded and doesn’t clutter the dash.
In-cab computers began to emerge in the early 1980s with the Rockwell Tripmaster. Displays from engines emerged in the early 1990s with such devices as the Cat ID. Then truck makers came up with equipment of their own that would draw on data from engines.
Wireless communications patched right into the cab come in a variety of technologies ranging from high — and low-orbiting satellites to analog and digital communications and even a system that sends information over FM signals.
The danger of it all is information overload.
“We worry about driver overload, about the driver’s ability to use these items while moving,” Freightliner’s Paul Menig said. “One possibility would be to have some sort of computer that is multi-function.”
While a handheld computer is one approach, Freightliner is looking to incorporate more functions into radio systems. “The radio better still handle AM, FM and weather band … run the CD and satellite radio,” Menig said of such approaches but it offers a logical area to expand computer power, with the simple addition of some enter keys, a cursor key, dedicated function keys and multi-function “soft” keys. Any combined system will need access to a Universal Serial Bus to handle everything from digital cameras to printers, fax machines, handheld Palm computers, and magnetic bar code readers, he added.Voice recognition software and text-to-speech systems are also on the horizon.
The Internet has a large role to play as well, according to International’s Jack Gemender. Web-based concierge services – such as those offering service locations, information on the cheapest fuel, traffic updates, the ability to check the status of a service – are the way of the future. And the Web can also help manage information about the status of shipments.
Broadband access to the Internet is driving the growth of application service providers, said Vinit Nijhawan, CEO of Kinetic Computer. Such providers would become central hubs for both data and software, and that could lead to an exponential growth in in-cab computers working on a common platform.
“The fear of obsolescence kept a lot of people away from on-board computers,” he explained.
But it isn’t likely the DOT will allow future regulatory information – such as automated logbooks – in a hand-held computer, said XATA founder Bill Flies. Such information, he said, will probably have to remain in a truck-mounted device.
The search for new ways to supply power is on – and nothing is being ruled out
As trucks are stuffed full of more electric and electronic gadgets, the trucking industry needs to consider new ways to supply power to equipment. That could mean the introduction of everything from new battery models to fuel cells, to simply reconfiguring the way traditional batteries are linked together.
Consider some of the drains on traditional power supplies: A radio will draw one to three amps per hour, a CB will take another 1.5, a fridge with a compressor that runs 50 per cent of the time will draw 3.5 amps, while blower motors running on high will draw a full 22 amps.
Even when a truck’s engine is off, various devices tend to draw six to three amps per hour, while at low idle you can expect to lose 36 to 56 amps, said Freightliner’s Paul Menig. At high speed there could be a drain of 40 to 61 amps.
But a 135-amp alternator seldom puts out its full capacity. When idle speeds drop to 600 rpm, it’s more likely to put out 50 amps, he said. “That’s a problem when you look at loads coming out of the vehicle.”
Part of the solution may be in the power that’s supplied.
Perhaps three batteries devoted to starting and one for so-called convenience items are enough for today. But that series will be further strained. With two devoted to starting and two batteries for convenience, there may be enough power for gadgets, but the two batteries may not offer enough power to turn over high-horsepower engines in cold weather, Menig added.
While gel cells used in marine applications have been tested as a solution to the heavy-amp draws from accessories, they haven’t held up to the constant vibration of over-the-road use, he said.
Using four starting batteries for all-purposes will work, but they will survive only 250 cycles, Menig said. The best solution in his opinion is to use four dual-purpose batteries with a low-voltage disconnect that turns off non-critical items – such as dome lights, cigar lighters and sleeper power – when the power drains so low that the truck might not start.
Optimized idle systems could automatically start and stop the engine to maintain power, but drivers aren’t crazy about the noise as they sleep, particularly because of the shaking that comes as an engine powers down, he said. For that matter, the engine may not run long enough to fully re-charge the battery.
Auxiliary power units, meanwhile, are seen as noisy, heavy and expensive, Menig said. Still another option is shore power, such as that offered by Volvo and Freightliner, but the number of truck stops that offer these power sources is limited.
“A/C inverters are not the answer to the problem,” Menig added. “Some inverters will decrease in output as time goes by.”
A 1,200-watt inverter will take 100 amps out of a battery, and that will require much larger wires to carry the load. That can be a safety issue, he said. Freightliner is now installing 1,100-watt Trace models.
Fuel cells, super capacitors able to start 14-litre engines at -40C, or air starters are all possible solutions, but they’re also in the future.
There’s no question that advancements are rapidly placing greater drains on power supplies. Only six years ago, mechanical engines were still available, there were 32 circuits and an 85-amp alternator, noted Mark Kachmarsky, Mack’s manager of vehicle electronics. Today there are two electrical distribution locations – a cab and engine power distribution module – in addition to such things as ABS modules. There are four 70-amp power relays, up to 64 circuits, and 130-amp alternators are the norm.
Where electrical schematics for a Mack truck were once printed on seven sheets of paper, the company now prints 19 sheets of information.
And more is coming. Brake by wire will put an added drain on power supplies, and steer-by-wire designs that replace driveshafts with a servo motor on the steering gear are a real possibility. Then there’s the research into electronic valve actuation, and the possible need of heating everything from exhaust catalysts to windshields.
“With the amenities in the sleeper … we could go to five batteries to supply that,” Kachmarsky said. “But at what point do you have too much weight?”
Manufacturers looking for new solutions to reducing emissions
The toughest emissions hurdles are still on the horizon for engine manufacturers. The latest model year of heavy-duty engines has met tightened emission standards without measurable drops in fuel economy. Manufacturers, however, are looking nervously to October 2002, when even-tighter standards will force dramatic changes in engine designs.
The 1999 and 2000 emission standards are essentially the same although those extending oil drain intervals need to keep a close eye on their oil analysis results because of the higher soot levels that come with changes to injection timing.
By the end of this year, manufacturers will have enough low-NOx rebuild kits available to outfit engines built between 1993 and 1998 (some engines aren’t affected until 1994 model years). Those engines have to be upgraded when users replace or recondition more than one major cylinder component in more than half the cylinders, said Cummins’ field service engineering director Tim Thompson. At best, heavy-duty engines won’t require the work until they reach 290,000 miles, while the limit for medium
-duty equipment is 185,000 miles.
The rebuild kits include some pistons, rings and liners, new calibrations for ECMs and a label confirming that the engine has been upgraded. Engine makers are paying the bill for the program that has to remain in place for 10 years.
However, there are questions about how engines will reach 2002 emissions targets.
“It (the deadline) is going to be on us before we know it,” Thompson said. The addition of Exhaust Gas Recirculation (EGR) equipment seems to be emerging as the ultimate way to meet tightening emission requirements that were originally planned for 2004.
Plans for EGR offer the best hope for lowering NOx, said Mack’s Chris Smith. Through the systems, exhaust gases are cooled, mixed with fresh air and fed back into the combustion process. But first the gases start out at 1,200 F before they are cooled to between 300F and 500F. That means more equipment such as a valve, piping, cooling system and electronics need to be added on engines. And with the cooling of EGR comes more heat that has to be handled by the radiator, meaning some changes in that equipment.
“We will still be using the coolants we are using today,” Smith assured. “We’ll still be using a radiator.”
But there will be new issues of higher soot and sulfuric acid levels in engines.
“We’re evaluating enhanced filtration,” he said, noting that oil manufacturers are also being pushed to develop new formulas. “Our target will be to maintain current oil drain intervals.”
Some other technology will include new injector rate shaping, the use of multiple injections and modified combustion chambers, said Smith. “But that’s already part of our typical engine development process.”
In terms of turbochargers, some wastegate models are already appearing on the latest generation of clean engines, while variable geometry turbochargers are available on medium-duty engines in Europe. Then there’s the option of twin turbos and multi-wheel turbos to increase the supply of air.
Plans for NOx aftertreatment devices simply aren’t viable in time for 2002, Smith says. “Their technologies are not mature yet.” But once they do appear, they could be anything from a urea-based de-NOx catalyst, to a NOx-absorbing variety or a plasma-assisted catalyst.
Aftertreatments could also emerge to control particulate matter, with an oxidation catalyst or regenerating particulate filter.
As the engine makers work to improve new engines, there’s also an increasing focus on existing engines through on-road enforcement.
The good news is that the emission test – the SAE J1667 – is “good science”, said Caterpillar’s Bob Wessels, referring to the snap-idle test that is the basis for emissions programs in Ontario and B.C. The 40 per cent cutoffs for the tests mark the threshold of visible smoke, but most engines are making the grade, he said.
“The biggest issue with the J1667 tests are with pre-1991 engines.”
Specifically, settings, injectors, turbos, and smoke-limiting devices are all causing high smoke in these engines, and there are problems if the test is run on a cold engine.
“It is a field test and it can be messed up … a brand new truck can flunk this test if it’s not run right.”
“The biggest Achilles heel of J1667 is somebody trying to run a test on a cool or cooled engine,” Blake agreed.
Software also needs to be corrected if tests are done above altitudes of 1,500 feet.
One of the great unknowns is a new EPA test procedure that’s supposed to be in place over the next two years, with the drivers of engines built in 2000 and beyond rolling over a pre-determined course for a minimum of two hours. And if they fail, the tests can be re-run nine times.
There are still questions about how trucks will be selected and who will drive the equipment, Wessels says. “There are no clear answers.”
Trailers could soon go from boxes on wheels to the next frontier in aerodynamics
While engineers continue to sculpt more aerodynamic trucks, several researchers and entrepreneurs are paying more attention to uncharted territory – the gaps between tractors and trailers, and the shapes of trailers themselves.
A tractor’s front end accounts for 40 per cent of a rig’s aerodynamic drag, but the gap between a tractor and trailer can account for another 20 per cent, explained Vic Suski of the American Trucking Association’s engineering department. The trailer itself, and particularly the area behind the barn doors, accounts for yet another 20 per cent.
The U.S. government is already funding a look at the aerodynamics of tractor-trailers since improvements here are seen as the most promising ways to improve fuel efficiency, said Frank Tokarz of Lawrence Livermore National Laboratory. Looking 20 years into the future, a 25 per cent drop in drag could in itself improve fuel efficiency by 10 to 15 per cent, he says. “At 70 mph, 65 per cent of (a truck’s) total energy expended is in overcoming aerodynamic drag.”
“You do not have to have a physical boat tail at the end of a trailer to have a significant difference,” added Suski, referring to ways to improve aerodynamics behind trailers. “There’s a way to fool the air to make it think the boat tail is there.”
“The front is in pretty good shape, but the rest needs work,” agreed Shawn Coyle of Aeroserve Technologies, referring to potential improvements in tractor-trailer designs.
Any trailer gap that’s more than 18 inches wide creates aerodynamic drag, he says. There are further problems with areas under the trailer. Side skirts closing gaps between a trailer deck and the road could make a difference in managing air flow, although current designs could be clogged by snow, make it difficult to inspect tires, and could be damaged on steep docks, he notes.
There are more than 60 patents filed on devices meant to reduce drag at the back of trailers, but none of them have been successful, Coyle added. His company is marketing plastic, triangular-shaped “vortex generators” that are attached around trailer edges to manage the flow of air as it rushes off equipment.
But another solution may be found in air itself.
Bob Englar of Georgia Tech Research Institute said aerodynamics could be improved by forcing jets of air around rounded corners, in an approach used to improve the aerodynamics of some military fighters.
The air could come from a form of a dedicated turbocharger, by bleeding air from a traditional engine turbocharger, or even from the exhaust system, he suggests. And the back edge of trailers would only need to be rounded to a radius of two to eight inches to make a difference.
The lift that’s created could even reduce or increase rolling resistance on command, he added, noting that shooting air from the sides of trailers could help improve overall stability and handling.
Do the guidelines for semi-fluid grease in truck wheels need to be refined?
The Maintenance Council may have new guidelines for using semi-fluid grease in wheel ends, but ExxonMobil plans to work with individual component manufacturers to refine the rules.
With an increasing number of fleets concerned about leaking seals making the switch to greases such as Mobilith SHC 007 and Unirex SHP 00 rather than oils in non-drive wheels, improper filling procedures were causing “catastrophic failures” – the dreaded loss of truck wheels. In most cases where problems were found, there simply wasn’t enough lubricant to protect the components.
According to TMC, the hubs should now be filled half way to ensure that there’s enough semi-fluid lubricant to do the job. Oils are traditionally filled to the 4 and 8 o’clock positions.
The recommended maintenance practice also includes checking bearing endplay every 100,000 miles or so and ensuring there’s enough grease in the hub. But there are questions as to whether wheel ends need to be pulled apart for the job – a practice that would virtually eliminate the long-life attributes of such semi-synthetic lubes.
“The requirement for the inspection is a very valid one,” says ExxonMobil OEM sales manager Sam Hughes, adding that a check of bearing endplay is probably the “ke
y” reason for inspections. “The Recommended Practice (developed by the Maintenance Council) is as good a general guide as you can get. We’re saying utilize good practices and check with the OEM … the application of the product does not circumvent sound maintenance practices.”
ExxonMobil is recommending a “post audit” on a few hubs after about three months in service, checking axial endplay and actually measuring the amount of grease in a hub if there are any lingering questions.