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New technology takes the multi-tasking out of low-speed maneuvering

By on January 1, 2016
Slowly-I-Turned

Truck drivers count seeing America from the cabs of their rigs as one of the main perks of the job. Traveling the nation’s highways, their views of the Great Plains and Rocky Mountains, of scenic river valleys, coastal shores or the skylines of our great cities are often beyond description.

But the job also often means having to run in city traffic, in heavy weather or in the close confinement of a shipper’s or receiver’s yard. Running 60 to 70 may be the dream, but there’s an awful lot of time when 2 to 5 mph is a daily reality.

And that reality takes a special set of skills.

A properly trained driver finds it relatively easy to travel at full speed, whether navigating a two-lane county road or highballing down an interstate. You keep the truck moving along, shifting only occasionally. You check your mirrors only a few times a minute to keep up with any changes in the traffic around you. You scan your instruments, more to make sure your truck is operating within range, knowing that the message center will alert you to any significant problems.

Contrast that with the task load when driving slowly, which requires knowing what might be happening all around the truck at all times. You need to look ahead, and you need to also scan your mirrors to spot the occasional unaware pedestrian or the nearby moving vehicle that may present an imminent danger. You need to do this both moving forward and in reverse. Traveling slowly in either direction means slipping the clutch and feathering the throttle. And, of course, it’s always best to back up in the lowest and slowest gear possible. And unlike open road driving, slow driving often requires you to do it all simultaneously.

Technology to the rescue

New technological advancements that pair the Eaton UltraShift Plus and Cummins ISX15 can relieve some of these driver workloads, allowing them to concentrate more on getting the job done and less on the mechanics of maneuvering.

The Creep Mode previously introduced by UltraShift PLUS has been enhanced with a feature called Blended Pedal, which works when the transmission selector is in low. It manages clutch engagement starting at idle, and continues to moderate it based on clutch and throttle position. The net effect is that by using only the throttle pedal, the driver is able to manage total control over vehicle speed regardless of how slowly the truck is moving. It makes manual-style control as easy as operating a car with an automatic transmission.

In Drive mode, a feature called Urge to Move engages. When the service brake pedal is released, the clutch smoothly ramps closed. This provides a passenger car feel on start up, minimizing the chassis twist-and-shudder every driver has experienced, especially under a heavy load or headed uphill.

A demonstration of this technology took place at Eaton’s proving grounds recently. A number of trucks equipped with the SmartAdvantage Powertrain (various UltraShift PLUS transmissions behind a lineup of Cummins SmartDrive ISX15 engines) were put through their paces.

The most impressive truck, in terms of pure pulling power, was a flatbed equipped with an UltraShift PLUS MPX18a (multipurpose extreme) loaded to 142,000 pounds GCW. There is a hill at Eaton’s proving grounds with an 8 percent incline on one side and 20 percent on the other. I drove up the lesser slope until the entire vehicle was on the incline, and then I stopped. Releasing the brake, I felt the truck roll back less than a foot. Then the technology took over and I climbed steadily to the top, accelerating smoothly and shifting as I went. Rather, I didn’t shift. The transmission did. That was practice for the other side, with its 20 percent slope. I stopped on the downgrade and again, technology kept me in total control, even in reverse. The 600 hp engine let me creep backwards up the hill — although it did take a significant amount of throttle.

Improved safety

Slow driving places multiple simultaneous demands on our senses, especially in restricted areas like shippers’ or receivers’ yards. Distracted workers who should know better can wander around with earbuds on while you’re trying to squeeze into your assigned dock. The situation can be worse in truck stops, where fatigue from a 14-hour shift can reduce awareness among the tired drivers and pedestrians.

By removing the burden of feathering the clutch and throttle, integrating transmission and engine automation frees a driver to concentrate on the truck’s surroundings, and thus on safety. Nowhere is this more important than in drop-and-hook operations, when backing up safely is critical. The Blended Pedal feature and Creep Mode allow you to keep your truck moving using just the throttle, even at the slowest speeds.

Once it’s time to move

Of course more than 75 percent of a line-haul and long-haul driver’s time is spent at highway speeds, and the Cummins and Eaton SmartAdvantage system provides benefits here, too.

Downspeeding has become something of a buzzword in truck sales today for one simple reason: It works.

Downspeeding the engine reduces the amount of lost energy by cutting friction losses and oil churn, and by reducing the cumulative mass of internal engine parts to be moved. The net effect has been about 1 percent fuel economy improvement for every 100 rpm drop in engine speed. Just a year or so ago, peak torque was achieved at 1,200 rpm almost universally. Today’s newest engines achieve it at 1,000 rpm, with trucks able to accelerate smoothly from as low as 800 rpm. That alone saves about 2 percent in fuel economy.

To accommodate these lower engine speeds, SmartAdvantage offers multiple technologies to match operator duty cycles. For typical operations above 62 mph, it offers small-step overdrive. The 10-speed transmission spends up to 30 percent of its time in 9th (direct) using drive axle ratios of 2.64 or 2.79-to-1.

The direct drive gear box is most economical for operations at or below 62 mph. It uses a direct drive transmission with axles ranging from 2.39 down to 2.26-to-1. Either drivetrain mated to the Cummins ISX15 offers an outstanding balance of smoothness, performance and fuel economy. At the proving ground, the trucks were put through tasks simulating the most demanding situations most truck drivers would ever encounter. The combination of the 1,550 or 1,750 lb-ft of torque selected by Cummins’ SmartTorque2 Vehicle Acceleration Management (programming that maintains consistently smooth acceleration) and SmartCoast — which uses GPS technologies to drop engine rpm to idle when descending hills in cruise control — led to one of the smoothest, safest, most comfortable driving experiences I’ve ever had.

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