Wednesday, August 24, 2005

Lancer Evo IX MIEV to be entered in the Shikoku EV Rally

Links to this post
Tokyo, August 24, 2005

Mitsubishi Motors Corporation announced that it would enter a Lancer Evolution MIEV1 test vehicle in the Shikoku EV Rally 2005 to be held August 27-28 in Tokushima Prefecture on the island of Shikoku, Japan. Deriving from the Company's Lancer Evolution IX high-performance 4WD sports sedan, Lancer Evolution MIEV uses a lithium-ion battery system to power four newly developed in-wheel motors. The Shikoku EV Rally 2005 is organized by the Shikoku EV Challenge Committee and the Shikoku EV Rally 2005 Executive Committee.

Mitsubishi Motors is driving forward the development of the Mitsubishi In-wheel motor Electric Vehicle (MIEV) next-generation electric vehicle and is planning to bring a MIEV model, built around core technologies of in-wheel motors and high density lithium-ion batteries, to market by 2010.

The Lancer Evolution MIEV will be the Company's second MIEV test vehicle, following the Colt EV announced in May 2005. The new in-wheel motor uses a hollow doughnut construction that locates the rotor outside the stator as opposed to a common electric motor where the rotor turns inside the stator. This construction brings several benefits. It makes it easier to raise power output and torque; higher torque allows the speed reducer unit to be eliminated, which means less weight and improved power transmission efficiency; and it offers better space efficiency with the brake assembly fitting inside the motor which itself fits neatly within the wheel house. The outer-rotor arrangement also surmounts the difficulties presented to date by the steering system, making it suitable for fitting to and driving the front wheels that opened the way to 4WD in-wheel motor vehicles.

Mitsubishi Motors has acquired vehicle type certification for Lancer Evolution MIEV and will be conducting practicality evaluations over a wide variety of conditions, the Shikoku EV Rally and other public road driving included. The evaluation programs will assist the Company in developing high-performance electric, hybrid and fuel cell vehicles that deliver not only superior environmental performance but also output performance and maneuverability equal to or better than gasoline-fueled vehicles.

1 Mitsubishi In-wheel motor Electric Vehicle

  1. Lancer Evolution MIEV: overview

    Mitsubishi Motors' MIEV concept comprises two core technologies: lithium-ion batteries, which the Company has been developing for practical application in automobiles; and the in-wheel motor that, as its name implies, mounts inside the vehicle wheels. Building upon the advantages offered by these technologies, the MIEV concept is currently the main driving force behind the Company's development of next-generation electric vehicles. Mitsubishi Motors also envisages the application of the MIEV concept in hybrid and fuel cell vehicles. The first MIEV test vehicle built by Mitsubishi Motors for in-wheel drive system development and testing purposes was the Colt EV, announced in May 2005. Derived from the standard production Colt compact model, Colt EV is driven by in-wheel motors mounted on the rear wheels and powered by a lithium-ion battery system.

    With the Lancer Evolution MIEV high-performance 4WD in-wheel motor test vehicle, the Company has taken the next step forward. After removing the engine, fuel tank, transmission, differential, drive shaft and other 4WD components from the production Lancer Evolution IX sports sedan, newly developed outer-rotor in-wheel motors were mounted on all four wheels. Fitted under the floor between the front and rear wheels in the space vacated by the 4WD components, a lithium-ion battery system powers the motors.

    The new in-wheel motor was developed by incorporating Mitsubishi Motors' vehicle installation technology to the motor manufactured by Toyo Denki Seizo K.K. The motor produces a maximum output of 50kW and its distinguishing feature is its outer-rotor construction. In the conventional type of in-wheel motor, as used on the Colt EV, the rotor turns inside the stator. The outer-rotor in-wheel motor, however, uses a hollow doughnut construction that locates the rotor outside the stator. The major benefits of this arrangement are as follows:

    • The design makes raising power output and torque easier and makes the speed reducer unnecessary, which reduces energy losses and restrains the increase of unsprung weight.
    • Elimination of the speed reducer makes the motor easier to fit into wheel house.
    • The doughnut construction creates space in center of the motor for the brake assembly and other components.
    The outer-rotor construction also allows the motor to be mounted on the front wheels, something not possible until now because of the presence of steering system components. This evolutionary feature has opened the door to the realization of 4WD in-wheel motor vehicles and widened the potential for EV's.

    One of the Company's major objectives in developing Lancer Evolution MIEV is to evaluate the outer-rotor type in-wheel motor construction, key to 4WD in-wheel motor vehicles, under an extensive range of driving conditions. To this end, Mitsubishi Motors has acquired vehicle type certification for Lancer Evolution MIEV to allow evaluation not only in the proving ground but also under normal driving conditions on public roads. These evaluations are designed to verify the reliability and durability of the outer-rotor in-wheel motor when subject to road surface inputs, to water inundation, and to exposure to sand and dirt - the major challenges this type of motor must overcome. The test program will also allow the Company to carry out research and development aimed at raising performance and at reducing weight and size.

    Leveraging its trademark all-wheel control technology and know-how, Mitsubishi Motors is also considering developing a system that controls drive torque and braking force independently at each wheel and is eying its use in Lancer Evolution MIEV. The Company will aim for the realization of high-performance electric, hybrid and fuel cell vehicles that deliver not only superior environmental performance but also output performance and maneuverability equal to or better than gasoline-fueled vehicles.

    Lancer Evolution MIEV layout

    New outer-rotor in-wheel motor schematic

    Lancer Evolution MIEV: specification (base model: Lancer Evolution IX)

    Length 4490 mm
    Width 1770 mm
    Height 1450 mm
    Curb weight 1590 kg
    Seating capacity 5
    Max. speed 180 km/h
    Cruising range / charge
    (10-15 driving pattern)
    250 km
    Motor
    (outer-rotor type)
    Type Permanent magnetic synchronous
    Maker Toyo Denki Seizo K.K.
    Max. output 50 kW
    Max. torque 518 N・m
    Max. speed 1500 rpm
    Dimensions 445 mm (dia.) x 134 mm
    No. fitted 4
    Battery system Type Lithium-ion
    Maker GS Yuasa Corporation
    Capacity 95 Ah
    Voltage 14.8 V
    L x W x H 388 mm x 175 mm x 116 mm
    No. of modules 24
    Controller Inverter
    Drive 4WD
    Tires 255/30ZR20

  2. Shikoku EV Rally 2005

    Open to electric vehicles licensed for use on public roads, the Shikoku EV Rally has been staged by scientists at universities in Shikoku every year since 1998 with the purpose of promoting the use of EV's. This year marks the eighth time the Rally has been held.

    Mitsubishi Motors has entered models such as the FTO-EV and Eclipse EV test cars in the Rally from the first Rally through 2003. The Company will be entering the recently completed Lancer Evolution MIEV in this year's Rally to test its driving and battery charging performance under normal driving conditions on public roads and to promote the MIEV next-generation EV concept among the general public.

    Date: August 27-28
    Venue: Tokushima College of Technology (Sakano-machi, Sakano-gun, Tokushima Prefecture)
    Organizing body: Shikoku EV Challenge Committee and Shikoku EV Rally 2005 Executive Committee
    Route details: 12 stages over public road with Tokushima College of Technology as the base point. Performance testing and measurement over special stages.


Gallery:



Lancer Evolution MIEV (base model Lancer Evolution IX)


New outer-rotor in-wheel motor

-Mitsubishi Motors Corporation

Wednesday, May 11, 2005

Mitsubishi Motors to drive forward development of next-generation EVs

Links to this post
Mitsubishi Motors to drive forward development of next-generation EVs
- Colt EV test car uses in-wheel motors & lithium-ion batteries -


Colt EV in-wheel motor test vehicle (base model: Colt Sport-X)



In-wheel motor

Tokyo, May 11, 2005 — Mitsubishi Motors has chosen to center its development of next-generation electric vehicle technology on in-wheel motors and on lithium-ion batteries that the company has been working on for several years. Currently working on a test vehicle that utilizes these technologies, which it has dubbed the Mitsubishi In-wheel motor Electric Vehicle (MIEV) concept, the company also envisages their application to hybrid electric vehicles and fuel cell vehicles.

The in-wheel motor makes it possible to regulate drive torque and braking force independently at each wheel without the need for any transmission, drive shaft or other complex mechanical components. For this reason, MIEV offers highly promising potential in the ongoing evolution of Mitsubishi's all-wheel control technology that is employed so successfully in the Lancer Evolution, Pajero and other 4WD models. The fact that the drive system is housed inside the wheel itself offers significantly greater design freedom and also makes it easier to locate such space-consuming components as the battery system, fuel cell stacks and hydrogen tanks used in hybrid and fuel cell vehicles.

Lithium-ion battery technology offers superior specific energy, specific power, and life over other types of rechargeable batteries and as such is expected to contribute to higher top speeds, extended cruising ranges and to greater weight reductions in hybrid and fuel cell vehicles.

Mitsubishi Motors has already started development and testing of the MIEV concept using a production compact vehicle, Colt, to serve as the rolling test bed. The Colt EV uses rear in-wheel motors powered by a lithium-ion battery system. The company is also currently developing a more powerful in-wheel motor for use in a 4WD test car. The Colt EV will be on display at the "2005 Automotive Engineering Exposition" to be held at the Pacifico Yokohama Exhibition Hall, Yokohama from May 18 through May 20.

1. MIEV concept

Mitsubishi Motors was one of the first automakers to start research into and development of the electric vehicle as an alternative fuel vehicle. In recent years, the company has turned its attention to the practical application of high-performance lithium-ion battery power to propel FTO EV and Eclipse EV experimental vehicles in 24-hour distance and public road test programs.

Exploiting the benefits of lithium-ion battery and in-wheel motor technology, the MIEV concept opens up new possibilities in terms of alternative fuel vehicle development. As well as seeking further possibilities for the EV, Mitsubishi Motors is also looking at the application of the MIEV concept to hybrid and fuel cell vehicles.

(1) In-wheel motor

I. Further evolution of all-wheel control technology
A major benefit of the in-wheel motor is that it enables drive torque and braking force to be regulated with high precision on an individual wheel basis in both two- and four-wheel drive systems without requiring transmissions, drive shafts, differential gears or other complex and heavy components. The in-wheel motor therefore holds great promise in terms of the contribution to the further evolution of Mitsubishi's all-wheel control technology that enjoys high critical acclaim on such production models as the Lancer Evolution and Pajero.

II. Greater freedom in layout design

Housing the drive system in the wheels gives greater freedom in designing the layout. This will facilitate the conversion of IC engine-powered vehicles into hybrid vehicles without requiring the introduction of complex hybrid power systems. It will also make it easier to provide room for space-consuming components such as fuel cell stacks and hydrogen tanks in fuel cell vehicles. The space-saving benefits of the in-wheel motors also offer exciting possibilities in terms of body design. Designers will be able to create innovative exteriors, improve dynamic performance through weight distribution optimization, provide roomier interior space and improve crash worthiness through optimization of the structural framework.

(2) Lithium-ion battery

Lithium-ion battery technology offers advantages of specific energy, specific power, and life over other types of rechargeable batteries. Mitsubishi Motors has already built several test vehicles using lithium-ion battery systems, including the Mitsubishi HEV in 1996, the FTO-EV in 1998 and the Eclipse EV in 2000. The FTO-EV set a multiple-charge 24-hour distance world record on a proving ground, while the Eclipse EV covered over 400 km on public roads on a single battery charge. These and other testing programs have enabled the company to verify the practical applicability of this type of battery.


MIEV schematic

2. Colt EV profile

The in-wheel motor test car, Colt EV, is based on the standard compact vehicle, Colt. After removing the combustion engine, fuel tank and transmission, two in-wheel motors were fitted to the rear wheels and powered by a floor-mounted lithium-ion battery system.

Rigorous proving ground tests are now being conducted on the Colt EV. The test car is scheduled to undergo a tuning program with independent control of drive torque and braking force for left and right wheels to improve dynamic performance. After receiving vehicle type certification, Colt EV will undergo verification testing on public roads. Mitsubishi Motors will use the on-road testing program to identify and resolve any problems unique to the in-wheel motor vehicle, including any deterioration in road holding and ride comfort due to increases in un-sprung weight, as well as reliability and durability issues in the in-wheel motor system and its peripheral components (suspension, wheels, tires).

Mitsubishi Motors is continuing its motor and battery research and development programs as it seeks to improve performance while reducing size and weight. The company is currently working on a 50kW in-wheel motor for 4WD vehicle use that will eventually feature individual drive torque and braking force control for each wheel.


Colt EV layout sketch


Colt EV specifications
Base model: Colt Sport-X (1.5-liter, 4WD)

Length 3885 mm
Width 1680 mm
Height 1550 mm
Curb weight 1150 kg
Occupants 5
Max. speed 150 km/h
Cruising range / charge (10-15 driving pattern) 150 km
Motor
(with internal reduction gear)
Type Permanent magnetic synchronous
Max. output 20 kW
Max. torque 600 Nm
Max. speed 1500 rpm
Dimensions 310mm (dia.) x 220mm
No. fitted 2
Battery Type Lithium-ion
Capacity 40 Ah
Voltage 14.8 V
L x W x H 194 mm x 175 mm x 116 mm
No. of modules 22
Controller Inverter
Drive Rear wheels
Tires 185/55R15

-Mitsubishi Motors Corporation