Daimler's Predictive Power Control "sees ahead" to help trucks save fuel
Daimler's new GPS-based Predictive Power Control system automatically shifts trucks into lower gears as they approach hills
Although transport truck drivers routinely shift gears when going up or down hills, those hills can sometimes sneak up on them. Using Daimler’s GPS-enabled Predictive Power Control, however, the new Mercedes-Benz Actros tractor unit will now be able to see those hills coming. This will allow it to automatically change gears before the going gets tough, resulting in fuel savings of up to three percent over moderately difficult topography.
In 2009, Daimler introduced a system known as Predictive Cruise Control, on its Freightliner trucks in the U.S. This uses GPS data to control the vehicle’s speed and braking functions for maximum efficiency, given its present geographical location. Predictive Power Control is built on this system, but uses its knowledge of the road ahead to also preemptively downshift the Actros by one or two gears.
According to Daimler, the system’s performance “could only be matched by an extremely motivated truck driver with an exceptional level of concentration.”
Source: Daimler via Wired
About the Author
An experienced freelance writer, videographer and television producer, Ben's interest in all forms of innovation is particularly fanatical when it comes to human-powered transportation, film-making gear, environmentally-friendly technologies and anything that's designed to go underwater. He lives in Edmonton, Alberta, where he spends a lot of time going over the handlebars of his mountain bike, hanging out in off-leash parks, and wishing the Pacific Ocean wasn't so far away.
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3% savings - considering the amount of fuel those trucks use - is nothing to sneeze at. They could probably squeeze another few percentage points out if they had topographical road data overlaid over GPS data, which could allow a cruise-controlled vehicle to pre-accelerate down a hill to help get over the next one, or merely turn the engine off when almost over the top of a steep hill, coasting down.
Self-driving vehicles will really be able to take advantage of every technique to save fuel, and freight vehicles IMO are actually a great first candidate for such autodriving systems, as they'd benefit the most from the positional data from sensors and fuel savings. Can't wait for the future to be here.
Wonder if anyone has calculated the surface area of our nations trucks to see how many millions of gallons of gas could be saved by using the free electricity produced by solar PV? These pollution monsters spew their stinky diesel smell and carbon monoxide back and forth across the country. Seems like some innovating engineer could alleviate this problem to some degree.
Systems such as developed by Permo-drive (before the term hybrid was a buzz word) have been implementing these predictive features for quite a long time.. (Using manual gear boxes, the original system was not able to actually down or up-shift earlier like this system, though there is always the potential to que the driver, like a shift light on dragsters), though the predictive nature of their software combined with GPS was able to plan energy recovery on the declines, to efficiently power the truck up the inclines on the old pacific highway (before all of the bypasses were put in..).
Have to remember that as these vehicles are running up against their speed limiter all the time (on flats and declines), accelerating on the declines is illegal, (not possible if the speed limiter is working as designed), dangerous and not particularly energy efficient. Recovering and reusing the energy from the declines on the inclines is a much more efficient method...
All cruise controllers should have accelerometers in them, to respond as the incline increases (before the speed begins to drop. ie. deceleration), and then reduce throttle response as the incline rolls off, which would reduce oscillations and over speed conditions when driving in undulating conditions on cruise control.
(Sure we could use MPC on all systems, but it is simpler (and more understandable for many techs) to retain a nested PID control regime in many simple systems... Sure, additional loops introduces non-linearities in the controller but as they will most likely be stable, who cares.)
MPC is more possible on frequently driven roads, if the database is automatically updated for road conditions. Though a small, offline sensor suite can also provide a limited horizon for predictive modelling to improve outcomes.
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