NUVU: RESHAPING THE CITY
10/02/2008
Nissan
Within just a few years, cities all over the world will be at near bursting point. If mankind wants to retain the level of personal mobility it currently enjoys - and if the city is to survive - the only way forward is for a radical rethink of the type of cars driven there. One solution could be a car like Nuvu, designed for the city of the not-too-distant future.
"Nuvu is literally a 'new view' at the future of the city car. It is electric, of course, but as far as Nissan is concerned, for tomorrow's city cars that is a given. No, the most important aspect of Nuvu is the interior design which provides great comfort and space in an intelligent package designed to make best use of our crowded roads and limited parking slots."
- François Bancon, General Manager, Exploratory and Advance Planning Department, Product Strategy and Product Planning Division, Nissan Motor Co., Ltd.
At a glance
2 +1 seating in compact 3m package
Unique platform for Nuvu
Zero emissions from EV drivetrain
Drivetrain previews production EV due soon
X-By-Wire control for all dynamic functions
Extensive use of natural, organic and recycled materials
An urban oasis complete with its own tree inside, which...
...provides shade for the interior, and
...generates solar energy via its 'leaves'
Overview
There is about to be a seismic shift in the urban landscape. Within the next five to seven years, some 55 percent of the world's population will live in the city, threatening total gridlock. Unless something is done, the irony of the phrase 'personal mobility' will be self-evident.
Look around at the cars in a typical city traffic jam today and the vast majority will have only one occupant and four empty seats. Some might have two occupants, a few three. But find one with four occupants or more and you'll be doing very well.
Today, we buy a family car knowing that we'll only ever need to use it to its full potential one or perhaps two percent of the time. Tomorrow, things will be different. Tomorrow, things have to be different.
"There is a new generation coming up who, finally, are questioning why we do the things we do. They are asking themselves, for example, why they are buying a large car when they know that for 99 percent of the time they will be in it on their own," says François Bancon, General Manager, Exploratory and Advance Planning Department, Product Strategy and Product Planning Division, Nissan Motor Co., Ltd.
"It is our job to provide personal transportation that is better suited to people's needs and to what the environment - in all senses - can cope with."
Nissan's vision for the future of urban transportation is encapsulated in Nuvu, a 'new view' of the type of car we will be driving in the middle of the next decade. Compact - it's just 3 meters long - Nuvu is a concept vehicle with unique 2+1 seating. It is aimed at urban dwellers who don't want to compromise on their personal freedom or their comfort, yet who appreciate that 'something has to give.'
Nuvu is agile, easy to drive, even easier to park. And it is, of course, an electric vehicle (EV). As Bancon says: "We believe zero emission vehicles are one of the key solutions for tomorrow's city car."
Nuvu is described as a moving oasis, a haven of green tranquility in the urban jungle. To underline this message, Nuvu incorporates a witty representation of its green credentials: across its all-glass roof are a dozen or so small solar panels. Shaped like leaves on a branch, the power they generate is fed to the battery using a 'tree trunk' within the car as a conduit. Nuvu also uses natural, organic and recycled materials within the cabin.
Nissan has already announced plans to introduce an all-electric car in Japan and the US in 2010 and to mass-market it globally in 2012. Nuvu is not that car, though it does share some of the technology that will feature in the planned production vehicle. Rather, it is a concept of how a Nissan EV might look in the near future.
In the longer term, Nissan foresees a future based around a line-up of zero emission vehicles regardless of their size, category and usage. Nuvu - or its production equivalent - is just one element of this emission-free future.
Nuvu in detail
The central thrust behind the development of Nuvu is not its motive power but its layout and use of space. Nuvu has been created for a city of the future, one that's even more crowded than today.
That's why it's compact on the outside yet roomy on the inside. Built on a unique platform, it's just 3 meters long and sits on a wheelbase of 1980 mm but is 1700 mm wide and 1550 mm tall to create a large and airy cabin.
Interior package
These dimensions provide all the interior room needed for the vast majority of city journeys. Nuvu has two regular seats and a third occasional chair that can be folded down when required. But, unlike some two-seater city cars currently on the market, it is a thoroughly practical proposition with an integral luggage area providing sufficient space for a typical supermarket or shopping expedition.
"It is a real car," says Bancon. "There would be no disadvantages to using a Nuvu everyday. For the vast majority of users, three seats are more than enough most of the time."
The packaging is designed to give priority to driver comfort with C-segment levels of space and the flexibility to invite one or two passengers on board. Cabin layout places the regular passenger seat beside but largely behind the driver's seat, allowing the passenger to stretch right out. Ahead of this seat is a third occasional chair which, when not in use, is folded away into the dashboard assembly. But even when the third seat is in use, there remains sufficient legroom for both passengers.
In the interests of saving both weight and space, the third seat has a center section made from hardwearing yet comfortable netting. This hammock-like approach also has the benefit of allowing cool or warm air to circulate around the occupant's body for extra comfort.
Shopping bags, briefcases and smaller items of luggage can be stowed behind the driver's seat while if the driver is traveling solo, larger items can be stowed in the passenger footwall.
City car research
"We did a great deal of research into how people use their cars in the city. We found that for 90 percent of the time, the driver was alone. For five percent of the time there was one passenger and for four percent of the time there were two passengers. You can do the math to find out how often four or more people were in the car!" says Bancon.
"We gave the second seat much more room than normal because when you take one passenger in your car it is usually someone you love and you want to make sure he or she is being carried in outstanding comfort," he adds.
Natural materials
Many of the materials used inside Nuvu reflect an increasing concern for the environment. The floor is made from wood fibers pressed into laminate sheets and is studded with rubber inserts made from recycled tires for grip. To create a light and bright interior, the windscreen and roof merge into one extended panel running virtually the entire length of the car. But undoubtedly the most unusual feature of the interior is the 'energy tree' which rises from the luggage compartment floor to the roof behind the driver's seat.
Solar panels
The energy tree is shaped like a thin trunk. As it reaches daylight it branches out under the glass roof providing occupants with protection from bright sunlight… just like a real tree. And providing a visual reminder of Nuvu's green credentials, covering the branches are dozens of small solar panels shaped like leaves.
The panels absorb energy from the sun which is then fed back down the energy tree and used to help recharge the battery and provide an extra power boost for the electric motor. As well as being genuinely green energy, it is estimated that the power generated via the solar panels will save the equivalent of one full overnight charge from mains electricity each month.
Driver controls are as simple as possible. All the major functions - steering, braking, transmission and throttle - are 'By-Wire' while the steering is controlled by an aircraft-style steering yoke: with just one turn from lock to lock, the steering is very direct for agility and maneuverability in the city. Nuvu's turning circle is just 3.7 meters. Thanks to its wide track and the use of 16 inch 165/55 tires mounted on lightweight, almost transparent, wheels, ride comfort, stability and agility is of the highest order.
There are two pedals - for stop and go - stalks for minor controls and a digital instrument panel with dials for speed, distance covered and battery range. The instrument panel itself is formed of layers - rather like an onion - and like the energy tree is another example of design inspired by nature. "We call it bio-mimicry," says Bancon.
Rear view/parking monitor
Two screens on the dashboard display the view behind the car - there are no door mirrors to disturb the airflow, but small cameras - and double as monitors for the Around View Camera which give a bird's eye view of the car when maneuvering or parking.
Saving energy was the guiding force behind the use of low-energy LED head and tail lamps, while Nuvu's heating and ventilation system filters and cleans the city air as it passes through the vehicle. Not only does it produce no emissions at source, but Nuvu actually helps clean up the city environment.
Exterior and interior design
"Nuvu's design is further clear evidence of Nissan's continued desire to challenge convention and to explore all the possibilities that the EV could bring us. In many ways it was inspired by our two most extreme EVs of recent times: Mixim and Pivo 2.
"Significantly, though, Nuvu delivers a more realistic interpretation of two of the most important aspects of its forerunners - the 'Friendly Innovation' found in Pivo 2 and the 'Sports Dynamics' central to Mixim
"The result? We have designed a radical concept car that with just a few changes could go into production tomorrow," explains Masato Inoue, Chief Designer, Product Design Department, Nissan Motor Co., Ltd.
Developed by designers at Creative Box Inc. - Nissan's design think-tank - Nuvu's green house has flowing lines with gentle curves inspired by nature. The distinctive shape of the door glass on either side gives the impression of a hot air balloon that's being gently inflated by pressure from within, while tropical fish inspired the profile of the side window graphics as a whole.
This contrast between the natural, fluid shape of the green house and the strength implied by the solidity of the lower body gives Nuvu a feeling of quality rarely found in a compact car.
Color and materials
Nuvu's visual impact is further enhanced by its unique body color. Developed by Nissan Design, the shade is officially called Soft Feel Sandy Gold.
Matching the ecological values of an electric vehicle, the molded plastics and synthetic elements found inside a typical production car have been replaced by natural materials and organic alternatives, such as the wood fibers and rubber from car tires used for the flooring. The result helps create a relaxed, warm atmosphere within Nuvu's cabin.
During the design development stage, key targets were to develop an EV that encompassed obvious modernity with engaging ambience and a playful aspect - hence the energy tree. "You don't need to be a car lover to fall in love with Nuvu," adds Bancon.
EV drivetrain
Nuvu is more than a styling concept of a future EV. It is a fully working mobile test bed for much of the technology that will be used in Nissan's production EV to be launched in 2010. For this reason elements of its technical specification are being kept secret for the time being.
The electric motor used in Nuvu is mounted at the rear of the vehicle and drives the back wheels, though neither its exact specification nor the power and torque figures are being released at this stage. A driving range of 125 kms and top speed of 120 km/h are being made public, however.
Li-Ion battery
Similarly although it can be revealed that the batteries used are of the latest laminated lithium-ion type and have a capacity of 140 Wh/kg (watt-hours per kilogram), the total capacity of the batteries and number of modules are not being disclosed at this stage.
Nissan began research into high output Li-Ion cells as long ago as 1992, but today development is carried out by Automotive Energy Supply Corp. (AESC), a joint venture company set up by Nissan and NEC Group.
Unlike a conventional lithium-ion battery with its bulky cylindrical cells, the laminated Li-Ion battery as used in Nuvu has thin laminated cells and fewer components overall. This boosts its power by a factor of 1.5 at the same time as halving its physical size. It also remains twice as efficient as a conventional cylindrical Li-Ion battery even after five years or 100,000 kms of continuous usage.
Another bonus of the compact cell construction is that a thin modular design is possible with a commensurate improvement in battery cooling efficiency. Higher power outputs are achieved through material improvements made to its lithium manganate positive electrode and carbon negative electrode. The use of chemically stable spinel-structured manganese for the positive electrode also helps ensure safe operation.
Its compact size allows the batteries to be mounted under the seats and the vehicle's flat floor, thus helping to keep the center of gravity as low as possible.
A quick charge from empty to full should take between 10 to 20 minutes while a full charge should take between three to four hours from a domestic 220v socket.
Typical users
"The people who will be drawn to a car like Nuvu are many and varied," says Bancon. "It is a cross generational car and not a signature vehicle for one generation.
"There will be common threads, however. They will be early adopters but more importantly they regard themselves as urban citizens. They don't just work or live in the city; they are part of the city. They want a car that somehow expresses who they are and which reflects their personal ideology."
Conclusion
Although clearly a concept vehicle exploring aspects of future vehicle design, Nuvu nevertheless embodies many messages for today. Its clever interior provides ample headroom, legroom and comfort for most everyday needs without occupying more road space than it needs.
The use of recycled and natural materials underlines Nuvu's environmental message and while the energy tree might be considered as a piece of whimsy, the use of solar energy is an entirely sensible and practical technological solution to aid an emission free future.
"Nuvu is a concept car, for sure, but it is an entirely credible vehicle," says Bancon. "It is light, clean and easy to drive. It is practical and a sensible size, yet it is also embodies an element of fun: the future doesn't look so bad, after all."
Creative Box Inc.
Much of the research in the concept that became Nuvu was carried out by a maverick design studio called Creative Box Inc. Although wholly owned by Nissan, Creative Box is run as an independent offshoot where the company's young designers are given a free rein to develop ideas and concepts for tomorrow.
Opened in 1987 in the lively Harajuku area of Tokyo, the designers are influenced by the urban buzz all around them. Away from the constraints of Nissan's corporate HQ, the designers set their own working hours so as not to limit their creativity. A youthful part of the city, Harajuku is home to unusual architecture, the latest in fashions and style, street theatre, new music and avant-garde food.
The designers are a diverse mix of people from all over the globe, producing designs that challenge convention. Concepts developed at Creative Box are just the sort of cars the young designers would like to drive themselves: they are, in effect, their own target audience.
Nissan's EV history
Nissan is today one of the world's leading exponents of EV technology and has announced plans to launch a new battery-powered vehicle in 2010, with sales starting in Japan and the US before introduction into Europe and other markets.
But that EV is far from being the first Nissan electric vehicle. In fact the company can trace its EV history back more than 60 years to the "Tama" model, which was introduced in 1947. The Tama was a family four seater with a huge rear hinged door on either side of the body to ease access to the rear seats.
The EV technology of the day was comparatively primitive so the heavy battery-powered Tama had limited performance and range. Top speed was 35kms, but it had a range of only 65kms between charges.
It wasn't until 1970 that Nissan looked again at battery power with the arrival of a tiny city car called 315X-a. This was followed three years later by the EV4 pick-up truck and, another year later, by an electric concept based on the Laurel saloon.
In the 1980s the company produced an electric vehicle aimed at the recreational market. Called the Resort, it was an open-sided multi-seater that was part golf buggy/part mini-bus in concept.
In the 1990s, Nissan stepped up development of the EV, especially on the technological side. A smooth coupe concept, the FEV appeared in 1991. This led directly to the two-door FEV-II concept of 1995 which was powered by a lithium-ion battery. The first production EV with a lithium-ion battery was the 1997 Nissan Prairie Joy. Based on the conventional Prairie people carrier, Prairie Joy was used extensively as a mobile development test bed.
Lessons learned were then put into two further EVs, R'nessa and Altra, both launched in 1998. Both were converted from standard petrol-powered cars while the Altra was sold to hand-picked fleet operators in California for further real-world testing.
At the same time, Nissan started experiments in a car-sharing program in Japan. The purpose-designed Hypermini EV was built in sufficient numbers (around 220) for an extensive car-sharing program to be instigated: cars were leased to the city of Yokohama with the aim of developing a new mobility program. The diminutive Hypermini was a highly advanced vehicle powered by a synchronized neodymium magnet type motor and a lithium-ion battery. It used recycled materials as well as resin panels and had a light weight and easy-to-recycle aluminum spaceframe.
Although the Hypermini car-sharing experiment went ahead, it wasn't until after the Alliance with Renault was in place that further EV development took place.
And that has happened at a rapid pace. The new millennium has seen no fewer than four concept EVs and the development of many new technologies designed to improve the practical performance and range of the EV. The revolutionary Pivo - revolutionary in every sense, thanks to its revolving cabin - appeared in 2005 and was followed two years later by Pivo 2, which incorporated X-By-Wire technologies, variable chassis geometry and four ultra-compact in-wheel motors.
Also making an appearance in 2007 was Mixim, a powerful EV using the newly developed Super Motor which boasted a top speed of 180km/h and a range of 250kms. Designed to prove that EV could still have sporting potential, Mixim was aimed at a generation of future drivers who have currently fallen out of love with the car.
Two more EV concepts have appeared this year: Nuvu at the Paris Salon and, earlier in the year, Denki Cube at the New York Show. Unlike Mixim, Pivo, Pivo 2 and Nuvu, the Denki Cube (Denki is Japanese for electricity) is based on an existing conventionally powered vehicle, showing how quickly an effective EV could be brought to market.
At the same time Nissan has forged alliances with other companies to speed up the development of many of the technologies central to the EV's future. These include development of the powerful disc-type electric motor with Fujitsu General, Ltd., and the establishment of AESC with NEC Group to develop the laminated lithium-ion battery.