Anticipatory planning is one of the defining characteristics of human intelligence. It is therefore a welcome development when our vehicles are also able to operate on an anticipatory basis by "looking ahead" - and actually seeing further than the human eye can.
Anticipatory operating strategy is the term our engineers use to refer to the onboard intelligence with which they send our plug-in hybrid vehicles out onto the road. Take the C 350 e, for example. Its system uses topographic information from the navigation system to get the battery into the most favourable state of charge for the current situation. A classic scenario: the hybrid vehicle is heading towards a long downhill gradient, on which energy can be recovered through regenerative braking. In this situation, the operating strategy controls the use of energy in such a way that a corresponding amount of energy is drawn from the battery to reduce the load on the combustion engine at the appropriate time. During the subsequent downhill section, the battery can then be recharged completely. Daimler has been using this system in selected hybrid vehicles since 2013.
But the C 350 e can do even more: The route-based operating strategy also draws on data from the navigation system, the difference being that it seeks to use the combustion engine drive as well as the electric motor and battery as efficiently as possible over a given route. On the journey from Hamburg to Munich, for example, the vehicle operates initially in all-electric mode in an urban environment. The combustion engine then takes over on the motorway. During the inter-urban stage, the traction battery is recharged as necessary to once again allow entirely emission-free operation of the vehicle in urban traffic. Furthermore, the haptic accelerator pedal, as it is known, can signal by a means of a double impulse when the driver should take his/her foot off the accelerator. This occurs, for example, when the radar system of the C 350 e detects that the vehicle is approaching a slower moving vehicle ahead on the motorway. If the driver responds accordingly, the system turns off the combustion engine so that the vehicle is in "gliding" mode. If the speed is still too high, the system engages the electric motor to brake the vehicle by acting as a generator – and thereby recovers energy.
The C 350 e has a fuel consumption of 2.4-2.1 l per 100 km. This equates to CO2 emissions of 54-48 g/km.
Predictive Powertrain Control: the "sharp eye" which allows to look ahead
An anticipatory driving style is even more important where trucks are concerned. This is due to the far greater mass of the vehicles. Unnecessary braking of such heavy vehicles after an acceleration phase wastes energy. Similarly, every unnecessary burst of acceleration translates into unnecessary costs. And costs are an important sales argument in the haulage sector. Daimler Trucks' mission is therefore to build efficient trucks. This is why our vehicles bring together a wide range of assistance systems, all of which have to meet one all-important requirement: our assistance systems respond adaptively to the characteristics of the current route. This applies in particular to the anticipatory cruise control system Predictive Powertrain Control (PPC), which is available for trucks as well as for selected buses. The system has excellent local knowledge. Thanks to three-dimensional map data, the world's first GPS-based cruise control adjusts the speed and gear selection optimally to the topography of the transport route.
On downhill gradients, PPC makes use of peak momentum and throttles back in good time when cresting hills. It intervenes in the gearshift strategy and also makes use of the transmission's neutral EcoRoll position. Thanks to these measures, trucks use up to five percent less fuel, depending on the topography. And that is good not only for the customer's bottom line, but for the environment, too.