​Today's farm machinery is more powerful than ever and packs in an increasing number of features. Leading global agricultural equipment manufacturer AGCO turned to List, a CEA Tech institute, for help developing simpler control interfaces. The goal was to come up with a control wheel that could be used to move intuitively through the tractor's tools and functions. The wheel also had to have a programmable haptic feedback feature.

The researchers developed a rotating knob integrating a motor and magnetorheological fluid whose viscosity varies depending on the amount of resistance needed. The hybrid system delivers quality haptic feedback characterized by fast response times and high force dynamics. Combining a visual display with the tactile sensations provided by the new interface improves the operator's perception of the machine's status.

For example, hard stops can be programmed depending on a tool's characteristics, increasing resistance can be configured depending on the level of stress the tractor is subjected to, and vibrating alerts can be set up.

A proof of concept prototype was built and tested in actual operating conditions with a tractor gear box and draft. The CEA will present a modified version of the technology (a joystick) at CES 2020 in Las Vegas in January 2020.