Bosch 48V mild hybrid system to be production-ready by 2017; Gen 2 prototype integrated in transmission for all-electric driving
Bosch is developing a 48V entry-level hybrid system that will be production-ready by 2017. “The boost recuperation system is the hybrid for everyone,” says Dr. Rolf Bulander, member of the board of management of Robert Bosch GmbH and chairman of the Mobility Solutions business sector.
Bosch says that the low-cost system, which enables start-stop functionality and braking energy recuperation, will deliver about a 15% improvement in fuel consumption, not only in controlled tests, but also in everyday driving situations. An electric boost feature also enables more dynamic acceleration; the motor generator provides the combustion engine with an additional 150 N·m of support during acceleration.
Unlike conventional ~400-volt full hybrids, the 48V system can utilize less expensive components. Instead of using a large electric traction motor, Bosch enhanced the generator to output four times as much power.
The motor generator uses a belt to support the combustion engine with up to 10 kW. The power electronics form the link between the additional low-voltage battery and the motor generator. A DC/DC converter supplies the car’s 12-volt on-board network from the 48-volt vehicle electrical system. The newly developed lithium-ion battery is also significantly smaller.
Bosch expects some 4 million new vehicles worldwide to be equipped with this type of hybrid powertrain in 2020.
Second-generation prototype. At the IAA 2015, Bosch will also be presenting a new second-generation of the entry-level hybrid that is currently still in development. In the prototype, the more powerful motor generator is integrated into the transmission and connected directly to the powertrain rather than to the combustion engine.
Both the electric motor and the internal-combustion engine are separable via a coupler, which means that they can provide power to the wheels independently. This allows the entry-level hybrid to provide all-electric driving even at low speeds—such as in stop-and-go traffic—in addition to immediate electric support for a short period of time.
The new hybrid also makes it possible to include in compact cars a function that will celebrate its debut in premium vehicles at this year’s IAA: a remote-controlled parking assistant that allows drivers to direct the parking maneuver from the curbside. The fully automatic parking assistant steers the vehicle into even the tightest parking spaces and garages safely and conveniently, without any stress or hassle.
The assistant uses ultrasonic sensors and is based on the fully automatic parking system found in vehicles with an automatic transmission. With the built-in electric motor, the system is capable of accelerating by itself and independently shifting between forward and reverse gears. Because the parking process is started by pressing a button on the ignition key, drivers do not even have to be in the vehicle. Bosch has also developed a smartphone app that allows drivers to operate the parking assistant from outside the vehicle.