|VIZIV-2. Click to enlarge.|
Subaru returned to the Geneva Motor Show with the VIZIV-2 plug-in hybrid concept. The automaker unveiled the first version of the VIZIV concept at the 2013 Geneva show (earlier post), followed by the VIZIV Evolution Concept at the 2013 Tokyo Motor Show.
The plug-in hybrid system combines a 1.6-liter diesel Horizontally-Opposed direct injection turbo (DIT) Boxer engine; high-torque-compatible Lineartronic (CVT) automatic transmission; one front electric motor; and two rear electric motors with vectoring. Subaru’s new independent rear motor-driven Symmetrical AWD system developed for VIZIV-2 points to a future generation of Subaru AWD technology.
While the diesel engine and front electric motor power the front wheels, at the rear two independent motors allow the same or different levels of torque to be applied to the left and right rear wheels, depending on driving conditions. The third motor powers the front wheels, with power provided by a lithium-ion battery pack.
The components for the hybrid system such as a high voltage battery are installed while maintaining the Subaru’s unique Symmetrical AWD (All-Wheel drive) layout. The layout delivers enhanced driveability based on its low center of gravity and superior weight balance.
|Drivetrain components. Click to enlarge.|
Besides helping acceleration and performance in all conditions, this AWD system employs torque vectoring to improve stability and agility—minimizing understeer by reducing power to the inside wheel and increasing power to the outside wheel.
This system automatically selects the best time to use each power unit according to its strengths and the driving conditions, achieving greater fuel efficiency and maximum stability and safety. The generous torque generated by the diesel engine and the electric motors ensures strong, linear acceleration and responsive performance.
During low-speed or city driving, the front and rear motors supply much of the vehicle’s propulsion, while the diesel engine and high-efficiency Lineartronic take over at higher speeds. The VIZIV-2’s auto start/stop system and its multiple charging methods—engine power generation, regenerative braking and plug-in charging—further improve efficiency.
VIZIV-2 features a new variation of Subaru’s SI-DRIVE driving control system, Hybrid SI-DRIVE, which allows the driver to select different profiles for the engine and transmission.
To the original system’s ‘Intelligent’ and ‘Sports’ modes, this adds an ‘Eco-Cruise’ mode which works in conjunction with the EyeSight driver assist system. Travel conditions, monitored by the EyeSight’s stereo camera, are continuously assessed and the data is used to fine-tune the engine and motor outputs in order to reduce fuel consumption and minimize emissions.
The VIZIV 2 Concept features a next-generation EyeSight system with stereo cameras that can detect emerging traffic conditions. The system combines with 360-degree sensing for autonomous driving.