|The NS4 plug-in concept. Click to enlarge.|
Toyota Motor Sales, USA introduced the Prius c (earlier post) and revealed the NS4 advanced plug-in hybrid concept at the North American International Auto Show in Detroit.
The Prius c (“c” representing “city”) is targeted at young buyers as a gateway vehicle to the brand and if designed to function as an urban-friendly vehicle with an engaging driving experience, hatchback utility, and a city cycle fuel economy rating of 53 mpg US (4.4 L/100km). The NS4 concept is a mid-sized dedicated plug-in hybrid, separate from the Prius family, and is one of Toyota’s concepts designed with future mobility requirements in mind for potential global market introduction by 2015.
|Prius c. Click to enlarge.|
TMS plans to bring the Prius c five-door hatchback to market in March of 2012, introducing Toyota’s Hybrid Synergy Drive to the subcompact segment with a starting MSRP of below $19,000. The all-new Prius c joins the Prius Family, which includes the third-generation Prius Liftback, the versatile new Prius v and the Prius Plug-in Hybrid, which will debut in early 2012.
Due to arrive in showrooms this spring, the Prius c will offer an estimated 53 mpg US in the city, and 46 mpg US (5.1 L/100km) on the highway, for a combined rating of 50 mpg (4.7 L/100km).
The Prius c is smaller and lighter than the midsize Prius with 19.1 inches less length (157.3 vs. 176.4 inches OAL) and 542 lb less weight than the Prius Liftback (2,500 vs. 3,042 lbs). In adapting the Hybrid Synergy Drive to the smaller Prius c platform, each of the system’s major components were re-designed to reduce weight, scale, and improve efficiency.
The Prius c’s packaging design strategically locates key drivetrain components within the chassis to help optimize interior space and handling. The compact 1.5-liter gasoline engine, transaxle and power-control unit are placed within the vehicle to help enhance weight distribution and lower the center of gravity. In addition, the hybrid battery and fuel tank are positioned together beneath the rear seat, ideally distributing their mass within the wheelbase to improve weight distribution to help enhance handling. By locating the battery and fuel tank below the rear seat, the Prius c is able to offer 104 cu. ft. of interior volume (87.4 cu. ft. passenger volume, 17.1 cu. ft. cargo volume).
The Prius c’s Hybrid Synergy Drive system integrates the operation of components that include a gasoline engine, an electric motor within a Continuously Variable Transaxle, a NiMH battery, and power electronics: power control unit (inverter), a DC-DC converter, a step-up converter and a hybrid control computer.
The Prius c relies on a SULEV (Tier 2 Bin 3)-rated 1.5-liter in-line, four-cylinder gasoline engine that utilizes an Atkinson cycle to increase efficiency. This engine produces 73 hp (54 kW) and 82 lb-ft (111 N·m) of torque, contributing to a total hybrid system output of 99 hp (74 kW).
|Prius and Prius c|
|Gasoline engine||Engine output||Motor output||Total system output|
Atkinson cycle with VVT-i
98 hp@5200 rpm
105 lb-ft@4000 rpm
|Prius c||1.5L, 4-cylinder
Atkinson cycle with VVT-i
|73 hp@4800 rpm
82 lb-ft@4000 rpm
The Prius c’s hybrid system utilizes a 144-volt nickel-metal hydride battery pack that has been located under the rear passenger seat, near the center of the vehicle, and low in the chassis to help improve the center of gravity.
Prius c offers three distinct drive modes: Normal, Eco, and EV mode. Eco mode reduces overall energy consumption by governing climate control and throttle to improve vehicle efficiency. Under certain conditions, the EV mode allows the Prius c to be driven solely by electric power for a short distance (under 1 mile) while remaining below 25 mph (40 km).
The Prius c’s body structure makes extensive use of lightweight, high-strength steel to help reduce vehicle mass and improve fuel economy. The use of high-tensile-strength steel contributes to the vehicle’s ability to absorb and disperse impact energies helping enhance occupant safety. The high level of torsional rigidity afforded by the Prius c body structure allows the suspension to be more optimally tuned for ride and handling.
The Prius c is equipped with nine airbags located to help protect the driver and passengers in the event of certain types of accidents. The new 2012 Prius c, like all Toyota models, is equipped with the standard Star Safety System, which includes Vehicle Stability Control (VSC), Traction Control (TRAC), Anti-lock Brake System (ABS), Electronic Brake Force Distribution (EBD), Brake Assist (BA), and Smart Stop Technology (SST).
Beyond the advanced plug-in powertrain and next-generation safety systems, the central theme of the NS4 concept is on the human connection to the car, said Jim Lentz, TMS president and chief operating officer, at the reveal.
We envision that by 2015, plug-in hybrid technology will have evolved significantly. Our goal is to develop a next-generation hybrid drive system smaller in size and lighter in weight, offering improved overall fuel economy, better acceleration, and longer all-electric range—all while maintaining a short charging time.
We see [the NS4] as a natural progression of automotive technologies by 2015. Our industry is changing very quickly. The automobile is being re-invented because its role in our lives is being re-defined. Customers want it to offer not just mobility from point A to B, but connectivity with all aspects of their lives. NS4 demonstrates Toyota’s take on the human connection to the car with technology that considers both emotional and rational relationships, person-to-car and car-to-society.—Jim Lentz
Traditional vehicle development cycles average four years, but this is rapidly changing. Vehicles have become another communication hub in the connected-consumers lifestyle and automakers must integrate the latest technologies into their product offerings, TMS said. Connected vehicles are the third-fastest growing technological device, behind smartphones and tablets.
Toyota has formed special alliances with technology leaders such as Microsoft, Intel and Salesforce to explore the creation of seamless vehicle interfaces with emerging technologies.
Safety. The NS4 concept’s Human-Machine Interface (HMI) provides a user interface built around a multi-touch screen with the look and feel of a smartphone. The operation conveys information quickly while minimizing distractions and maximizing driver awareness. The multimedia and vehicle-controls enhancement also will direct air conditioning, audio, battery-charge and navigation functions. The HMI system is even capable of “learning” driver preferences and habits to anticipate driver responses in specific environments and situations.
The NS4 introduces a next generation Pre-Collision System (PCS) with lane departure, rear-end and pedestrian collision avoidance technologies designed to predict collisions under certain circumstances and help avoid them. This PCS uses millimeter-wave radar and stereo cameras mounted on the front of the vehicle to detect and react to lane departure, pedestrians and other vehicles. In addition, the system emits near-infrared beams to enhance PCS recognition at night. This driver assistance feature helps to avoid collisions with other vehicles, road-side obstructions, and pedestrians by applying the brakes and manipulating steering.
The current generation PCS, available in certain Lexus and Toyota vehicles, is designed to identify certain objects directly in the road ahead. If PCS determines that a collision is imminent, the brake assist system is placed in standby mode, a warning is displayed and a buzzer sounds. If PCS determines that a collision is unavoidable, the system still will alert the driver via a warning light, warning display and buzzer, apply the brakes and automatically retract the driver and front passenger seatbelts.
Adaptive Driving Beam (ADB) headlights help prevent vision-impairing glare to oncoming drivers and pedestrians. Using a camera mounted behind the front grill and partial shielding inside the headlights, this feature allows drivers to maintain near-high beam illumination to improve nighttime visibility.
The pop-up hood structure automatically raises the rear of the hood to increase the space underneath, helping to reduce pedestrian head injuries caused by a collision with the front of the vehicle, within certain speed ranges. This innovation is the result of testing and verification using both conventional crash-test dummies and Toyota’s Total Human Model for Safety (THUMS) virtual model.
Using sub-millimeter wave radar, the Blind Spot Monitor (BSM) is designed to detect a vehicle in the adjacent lane and visually alerts the driver using visual indicators placed in the upper dash.
Glass technology. Four new glass technologies are integrated into the windshield and front triangle, door, and rear windows to improve driver visibility, gas mileage and electric driving mode mileage efficiency:
Hydrophobic coating. Fluorine-coated glass causes rain drops to form into semispherical shapes for improved visibility and rain drop elimination (also used on the roof solar panel).
Anti-fog film. High-performance resin material with anti-fogging characteristics and increased durability.
High ultraviolet (UV) absorbing inner-layer. Removes 99% of harmful UVA and UVB rays.
Anti-solar film with radio-wave transparency. Reduces the internal vehicle temperature and improves electronic device functionality.
Inner and outer rear view mirrors have been replaced with cameras that provide the driver with a panoramic rearward view. The rearward image is displayed on a dedicated dashboard mounted screen above the navigation screen and provides a wider view than conventional rear view mirrors. The rearward panoramic camera view working in combination with the Blind Spot Monitoring (BSM) system enhances driving visibility.