Stewart II: A Revolutionary Human-Machine Interface

Driving Autonomous Vehicles with a Haptic Interface

Stewart II is a haptic interface that mediates between the driver and the autonomous vehicle. It provides constant updates about the car's behavior and intentions, allowing the driver to intervene if they disagree with the car's next course of action. This unique design aims to foster a healthy relationship between man and machine through an expressive form of interaction.

The design's inspiration stems from the 'H-metaphor' introduced by F.O. Flemisch et al., which likens driving an autonomous vehicle to riding a horse. The rider can give the horse more control by loosening the reins or less control by tightening them. Similarly, Stewart II allows the driver to control the autonomous vehicle to a degree they are comfortable with.

Stewart II is a fully interactive prototype used for design research and testing in a driving simulator study. It is made using 3D printing, laser cutting, Processing, and Arduino. The prototype is based on an octahedral Gough-Stewart platform, which has 6-degrees of freedom (6-DoF). These synergistic movements are linear (lateral, longitudinal, and vertical), and rotational (pitch, roll, and yaw).

Stewart II's design is not just about performance but also about being visually and haptically expressive. The top of the platform has an ergonomic asymmetrical handle that conveys directionality and orientation and has a clear affordance for grasping. The platform can sense external forces in 2-DoF (lateral and longitudinal), which are used for registering user intent.

The design of Stewart II has been recognized for its innovation and potential impact on the future of autonomous driving. It was awarded the Golden A' Product Engineering and Technical Design Award in 2017, a prestigious accolade granted to trendsetting creations that advance art, science, design, and technology.

Stewart II is a testament to the potential of human-machine interfaces in enhancing the driving experience. By enabling a haptic dialogue between car and driver, it offers a glimpse into the future of autonomous driving where the experience is not just about reaching a destination, but also about the journey itself.