Engineering Predictive AWD

One of Mazda’s guiding principles is Hashiru Yorokobi – translated, it means the joy derived from driving. Understanding how a car is going to respond to pedal and steering inputs allows the driver to feel more comfortable behind the wheel.

“It’s being able to get into a machine, control it, and do way more than your body should be capable of doing, without activating fear,” said Mazda development engineer Dave Coleman. “Our concept of Jinba Ittai is when Hashiru Yorokobi is applied to driving dynamics.”

Those values formed the core of Mazda’s goal set for its new AWD system:

• Preserve the precise, intuitive, Jinba Ittai feeling, even on low-grip surfaces.
• Function seamlessly and invisibly, with no input from the driver.
• Do it all with negligible impact on fuel economy.

“What we’re trying to do with the i-Activ all-wheel-drive system is take that same precise driving feel that we’ve got on dry pavement, and expand where we can feel that,” Coleman explained. “We want to be able to hit a puddle in the middle of the corner, and have the car continue to do exactly what you want it to do. When we’re on snow, we want to feel as precise and controllable as we do on pavement.”

It took an engineering breakthrough to achieve the kind of precision and confidence that Coleman wanted.

“The transformation we’ve made with our Skyactiv generation of cars comes from an internal clarification of our philosophy, and that philosophy then focuses our engineering,” Coleman says. “After study of human perception, we found a gap between the amount of front tire slip we can recognize through wheel speed sensors and the threshold a driver can recognize. This gives us a control window to manage front tire slip while maintaining Jinba Ittai.”

By integrating 27 different sensor inputs more than 200 times per second, the i-Activ AWD system recognizes a pre-slip condition and responds before the driver can possibly feel what is happening.

“We needed to make the AWD system intelligent enough to understand the conditions and anticipate when the tires were going to slip, and direct power to the rear wheels to control traction,” Coleman recalled.

The result is a truly predictive AWD system that maintains Jinba Ittai in all weather and road conditions. The i-Activ system goes beyond “on-demand” AWD by actually anticipating the demand and responding before the driver even knows that a slip was prevented. Driving with that level of confidence is true Hashiru Yorokobi.