Section 8. Integrating IT and Exploring New Energy Sources

Item 1. Development of Prius and Hybrid Strategy

Prius development completed in approximately two years

Toyota's first hybrid vehicle development dates back to 1968, when Toyota Motor Corporation (TMC) Project General Manager Kenya Nakamura, who had led the development of the first-generation Crown, started work on the development of a system using a gas turbine engine.1 Partly because there were no secondary, or rechargeable, batteries at the time that met the performance requirements for a hybrid vehicle, the project was discontinued at the beginning of the 1980s.

It was in 1993, when in-house discussions over a "vehicle for the 21st century" intensified, that the development that led to the Prius got under way. In that year, the G21 Project was launched as a means to promote technological development, and, with Project General Manager Takeshi Uchiyamada at the center, efforts began toward finding ways to achieve a groundbreaking improvement in fuel efficiency that would light the way in the 21st century.

With the improvement of engine efficiency its primary objective, the G21 Project at first set a target of raising fuel efficiency performance to 1.5 times the level of that of conventional engines. However, in a top-down move, Akihiro Wada, the executive vice president for research and development, ordered the high target of a two-fold improvement. In the summer of 1994, the basic G21 concept was approved, but it was not until it was decided later that a concept vehicle would be shown at the Tokyo Motor Show in the autumn of 1995 that the hybrid approach entered the picture. A decision was made to give the concept vehicle a hybrid format because a hybrid offered the prospect of doubling fuel efficiency.

But from the autumn of 1994, when development of the motor show concept vehicle was started, and into the winter, a major change occurred in the corporate atmosphere within TMC. As a result, it was decided to go for a hybrid format for the production version as well. Thus, rather than centering on engine improvement, the project had shifted focus to the adoption of a hybrid system. The upshot was the completion in the autumn of 1995 of a prototype model that was exhibited at the Tokyo Motor Show and which used a capacitor as the electricity storage device.

In 1996, to accelerate hybrid system development, the departments responsible for the development of control systems, and electric-drive and other components were integrated, and a cross-functional in-house structure was set up under TMC's so-called "business reform (BR) structure". The new in-house structure was integrated in January 1997 with the EV Development Division to become the Electric & Hybrid Vehicle Engineering Division.

In March 1997, TMC completed and announced the Toyota Hybrid System (THS), which featured an integrated electric motor and generator linked to a power split device, resulting in a combination series-and-parallel hybrid system. A production system was then put in place at the Takaoka Plant and the vehicle was ready for sales launch at the end of the year. The main components of THS, the electric motor and inverter, were manufactured in-house, while production of the nickel-metal hydride battery pack that served as the secondary battery was commissioned to Panasonic EV Energy Co., Ltd. (now Primearth EV Energy Co., Ltd.), a company established jointly in December 1996 by TMC and Matsushita Electric Industrial Co., Ltd. (now Panasonic Corporation).

The project to create the first-generation Prius was unprecedented in that it took a basically unknown and unproven technology all the way to completion and mass production in only approximately two years from the official start of development. The demanding schedule was managed thanks to a system for promoting progress that united the whole company, allowing, for example, the vehicle assembly process to be planned using 3D virtual assembly technology that had been under development in the Production Engineering Group, and to make use of a body welding line for small-volume production.

As this was the first-ever mass-produced hybrid passenger vehicle, a special joint team was formed to deal with technology, service, and quality assurance so that response to initial market issues after the sales launch could be handled promptly. On the publicity front, the Prius was featured in the Toyota Eco Project corporate advertising series that ran throughout 1997. Using the catchphrase "Just in time for the 21st century", strong emphasis was given to the advanced nature of Toyota's environmental technologies.

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