Creating a world-first 2-Drive EPS-MCU

in just the third year with the company

Oct. 4, 2019 Other Topics

DENSO received the Minister of Education, Culture, Sports, Science and Technology Award in Japan in April 2019 for developing the worldʼs first 2-Drive Electric Power Steering MCU. We introduce our associate who is part of the companyʼs team that received the award, and his story of the developing.

DNJP Chassis Control Components Eng. Div.

Toshihiro Fujita


The first guest is Toshihiro Fujita from the Chassis Control Components Eng. Div. He is the youngest member of the winning team.

Determined to develop safer steering system for the automated-driving era

Automated driving will make the roads safer and more secure. Japan is aiming for Level 3 automated driving*3 on expressways by 2020*2. Under the circumstances, DENSO started to develop a 2-Drive EPS-MCU in 2008. In EPS, an electric motor provides power assistance to make the steering wheel easier to turn. In the automated-driving era when drivers wonʼt even need steering wheels, a more sophisticated steering assist system will be needed. For example, a sudden failure of power steering while the occupants are enjoying the convenience of automated driving could cause the vehicle to fail to negotiate a curve. To get closer to a fool-proof EPS-MCU, our team started to develop a dual-assist EPS-MCU that continues to function properly in case one of the unit breaks down.

Working on a major project in my third year with DENSO, I relied on my supervisor

I was so surprised when I was asked to join the big project because it was only my third year with the company. I didnʼt know why I was chosen instead of my seniors who had more experience, but I was excited by the project and its opportunity to test the skills I had been steadily developing over the last three years.

I was assigned to the development of a power module, which drives the motor of the 2-Drive EPS-MCU. Our new EPS-MCU was designed to be ultimately downsized by integrating two control devices: an ECU and a motor in a single unit as large as a conventional electric power steering motor.

The power module was particularly important as it influenced the size of the ECU.

We looked for various ways to miniaturize our new EPS-MCU. For the power module, we decided to divide it into modules by function and stack them instead of aligning functions in the same plane. However, DENSO had little expertise with such a configuration, so I had to use a process of trial and error over and over again. I tried to develop and test hypotheses, but found they didnʼt work. Whenever I thought I had found the answer, another issue cropped up and I had to change my design drastically. Even with experienced design changes, our team including veteran members was becoming increasingly skeptical about the possibility of creating a power module with modularized functions. And yet I could continue my work largely thanks to my supervisor. He was surprisingly generous about my failures, so I was encouraged to motivate the other people

involved in the project, perform trial and error until I was satisfied, and plan ahead.

The method I came up with in my third design change was criticized because it seemed to involve manufacturing problems, but my supervisor trusted me, which was very reassuring. Usually prototypes are produced by the Prototype Mfg. Dept. Even though we were a design team, we wanted to produce prototyping on our own in order to prove feasibility. He agreed with the opinion and immediately get the budget and the equipment.

After seven years, we eventually succeeded in developing a power module with modularized functions. Our new power module, the worldʼs first product of its kind, is highly valued by our customers and people both inside and outside the company.

Working on a major project in my third year with DENSO, I relied on my supervisor

State of the workplace
Mr. Fujita and his supervisor, Mr. Kabune

Keep on challenging is the only way to success

This is what I learned from the project. You can start small. I always challenge myself in my daily work, believing that major success is the result of constant small efforts.

  • *1 Electric Power Steering Motor Control Unit
  • *2 Adriving automation system performs all operations(under limited conditions). The driver must respond when requested by system.
  • Source : Based on da ta of the MLIT Autonomous Driving strategy Headquarters with some modifications
  • *3 Source : Public-Private ITS Initiative/Roadmaps 2018

We will introduce associates who are energetic in our company on an irregular basis.