FROM DELICATE TO TOUGH, ULTRA-PRECISE STANYL® PA46 GEARS HELP KEEP JOYSTEER® POINTED IN THE RIGHT DIRECTION

Precision gears made of Stanyl®, a high-performance polyamide 46 (PA46) resin from DSM Engineering Plastics, help a new joystick-based drive-by-wire system translate a driver’s steering movements into vehicle control. Called Joysteer®, the new system was designed to enable drivers with arm muscle disabilities get behind the wheel – or in this case, joystick – and drive by themselves. Joysteer will be demonstrated at Hannover Messe 2006, 24-28 April, a leading showplace for mechanical and plant engineering, electrical engineering, electronics and the automotive sector.

Developed at the highly-regarded Bern University for Applied Sciences HTI-Biel, Joysteer, augments a car’s conventional steering wheel with a pair of joysticks mounted on either side of the wheel. These are electronically coupled to the vehicle’s steering mechanism. At Hannover Messe, Joysteer will be demonstrated in a Volkswagen T5 Multivan, donated by the automaker, at Stand A28, hall 2.

Developed in close cooperation with the school’s design team and with the fabricator of the gears, Mikron Plastics Technology, the Stanyl gears play important roles both at the joystick and at the vehicle’s steering shaft. The application runs the gamut of performance from delicate to tough, with both applications depending on Stanyl’s dimensional stability, low friction, and ability to absorb vibration and noise.

Said Hans Wennekes, Business Development Manager, Stanyl, “The gear sets in both the joysticks and the motor drives are zero backlash. That’s the only way the joystick can deliver absolute precision for encoding, and it enables the tightest possible steering control, without wander. Technical collaboration between DSM, Mikron and HTI Biel – or, if you will, the material maker, the gear cutter and the design team – was the only way such a precise mechanism could have been developed.”

The joystick gears must precisely translate small movements to programmable encoder circuitry. The movement required is small, and the touch must remain light. The steering shaft gears, on the other hand, must apply strong forces to the vehicle’s steering system, calling on Stanyl’s resistance to fatigue and mechanical stiffness and strength.

A critical innovation in the design is feedback to the driver. Small motors in the joystick mechanism provide variable resistance that is sent back to the driver through the Stanyl joystick gears. This resistance signals the severity of the turn and also transmits the road feel of bumps and surfaces to the driver. This enables the system to give drivers the same kinds of tactile information a driver would sense while using a conventional steering wheel. The degree of feedback can be programmed for a given driver’s muscle capabilities.

At HTI Biel, a team of employees and faculty, backed by a close-knit group of industry sponsors and participants, has worked over the last four years to perfect Joysteer. The technology won the Swiss Technology Award 2006. Key development members have founded a new, spin-off company, also called Joysteer. A broad range of sponsors and advisors, including automotive manufacturers as well as associations and foundations for the disabled, have provided important support from the start.

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