Trucking 2002

| November 01, 2002

Think of all the drivers a quarter of a century ago who thought their tractors were dream machine compared to the iron horses of the 1950s. Take a quantum leap forward to the modern technology available on 2002 models, which often sport cabs resembling cockpits of small airplanes.

Computers, global positioning satellite systems and driver-friendly controls have helped transform the industry to make a hard job a little easier for today’s trucker.

Split-second calculations
Back in 1977 about the closest thing to an engine computer you could find was an improved mechanical governor in the injection pump or unit injector system. It had been radically changed by all the manufacturers to produce “torque-rise,” which meant engines that pulled better when lugged down than traditional diesels. The result was reduced shifting, especially when climbing grades.

Today there is a computer on the engine in place of the mechanical governor. It’s an electronic microprocessor that can make thousands of calculations a second. It was put there to increase the precision and flexibility of the injection system to help meet emissions standards. But, as everyone soon found out, putting it on the truck was like Pandora opening her box. That’s because one of electronics’ greatest advantages is its programmability-you can tell the computer to solve any problem, and therefore perform any function that you can provide hardware for.

In the ’70s, the driver’s foot moved a lever on the pump governor with the throttle pedal and a cable. Now, the throttle pedal only changes an electronic signal sent to the computer. That makes the throttle action very smooth and precise.

But engine computers do a whole lot more.

Super Cruisin’
One of the best examples is modern cruise control. You could get cruise control in 1977, but it was an aftermarket system with little electronic sophistication. As a result, it reacted roughly to changes in grades, causing uneven bursts of engine power, and it was unreliable. Today’s ECM controls how much fuel the engine’s injectors pump in and it reads truck speed off a speed sensor on the back of the transmission. Today’s cruise control, smooth and reliable, is just a function programmed into the engine ECM. There’s no separate hardware except some simple switches. And these days your cruise control can be integrated with other systems.

One such connection, says Bill Gouse, vice president of engineering at the American Trucking Associations, is a sonar system called Eaton Vorad. It’s biggest job is to warn the driver in fog or other low visibility conditions when he’s approaching a vehicle ahead at too fast a speed or following too closely. It sends high frequency radio waves out in front of the truck and measures what comes back. If there is something ahead, it can figure out the distance and how fast it is moving.

Vorad also reads vehicle speed from the engine computer and then integrates that information with the speed difference and distance between the two vehicles. It considers the speeds involved before warning the driver.

But it also has another function. This, says Gouse, is its “active cruise” function. It adjusts the cruise setting downward when a truck whose cruise control is set for 65 mph encounters another vehicle ahead doing, say, 62 mph. The speeds of the two vehicles will quickly match, and at a following distance that is appropriate for the speed. The driver can continue running without resetting the cruise speed.

Among other big technology leaps forward, Ralph DeGenova, marketing manager at Volvo Trucks North America, cites the variable power curves modern engine computers can handle. Fleets have never been eager to spec maximum power in a truck engine without some kind of speed limiting. Drivers too often use that power to quickly reach and hold higher speeds that waste fuel. Modern engine computers can rate the engine at, say, 430 horsepower normally, then boost it up to 500 hp when in cruise control. The cruise control’s range can be restricted so it can’t be set above the fleet’s approved maximum speed, say 65 mph. When the driver sets the cruise, his engine suddenly climbs hills with 500 horses, minimizing shifting and improving the performance of his vehicle without wasting a lot of fuel. This system, too, has no separate hardware.

Other such electronic integration saves novice and experienced drivers alike embarrassing and expensive moments. DeGenova points out that, for example, on a dump truck, the PTO can be integrated with the transmission. This way, once the driver shifts out of the lowest gears, the PTO disengages and he won’t ever be running down the road at 55 mph as the dump body rises to meet a bridge.

The driver message display on the Mack Vision tractor uses a high-contrast display made by Planar Systems. A tremendous amount of research went into making it possible to read the display in less than two seconds, so the driver can maintain his view of the highway.

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