Drivers with disabilities benefit from resin

A DSM Engineering Plastics product story

Edited by the Engineeringtalk editorial team Apr 26, 2006

Polyamide resin helps joystick-based drive-by-wire system translate a driver's steering movements into vehicle control; the system was designed for drivers with arm muscle disabilities.

Precision gears made of Stanyl, a high-performance polyamide 46 (PA46) resin from DSM Engineering Plastics, are helping a joystick-based drive-by-wire system translate a driver's steering movements into vehicle control.

Called Joysteer, the 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, 24th to 28th April.

Developed at Bern University for Applied Sciences, 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 car maker, on stand A28 in hall two.

Developed in co-operation with the university's design team and with the fabricator of the gears, Mikron Plastics Technologies, 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 the university - 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 transmits the road feel of bumps and surfaces to the driver.

This lets the system 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 the university, a team of employees and faculty, backed by a group of industry sponsors and participants, has worked over the past four years to perfect Joysteer.

The technology won the Swiss Technology Award 2006.

Key development members have founded a spin-off company, also called Joysteer.

Sponsors and advisors, including automotive manufacturers as well as associations and foundations for the disabled, provided support from the start.