Piloting cars in the fast lane

An on-board computer and joystick control Mercedes-Benz’s latest development

By Sue Stuckey

Learner drivers of the future could take a test more akin to a pilot’s if a conceptual car design developed by Mercedes-Benz is a success.

The F200 Imagination coupe’s steering, braking and acceleration are controlled by an aircraft-style joystick in a central console or the door recess.

Radio-based drive-by-wire technology enables the driver to control the car. For direction you move the joystick left or right, and forwards and backwards controls speed and braking.

Drivers at the Mercedes-Benz test track near Stuttgart say cornering is more precise, braking is faster and parking easier than with traditional cars. As there are no mechanical or hydraulic linkages to cause friction in the drive train, ride is smoother.

Electronic messages transmitted by radio connect the movements of the joystick to the car wheels via a universal joint that moves the wheels and allows the car to change direction. Speed is controlled by an on-board computer with a two-way link to the engine and gearbox monitoring and controlling performance.

The computer includes an intelligent active suspension – intelligent because the movement of a wheel, say, is analysed and compared with `expert’ software held in the computer. This says what should be happening when there is a change of speed. And it is active because it constantly responds to road conditions through computer control of the springs.

Some aspects of the vehicle design are filtering through to production.

The latest S and SL models are fitted with Brake Assist – a computer-controlled intelligent braking system which compensates for a driver’s deficiencies. One of those is failing to depress the brake pedal fully during an emergency. Software detects the early stages of an emergency stop and completes the braking process.