Drive-by-wire

Drive-by-wire refers to vehicle systems that use electronically controlled actuators to perform functions that, in the past, were operated by mechanical connections.

Electronically actuated throttles are currently the most common form of drive by wire, and have largely replaced cables and linkages as the preferred method of controlling engine speed.

Such systems offer a range of benefits to the vehicle manufacturer, and the motorist.

Drive by wire throttles -

• Simplify vehicle design by dispensing with cables or linkages
• Reduce noise paths into the passenger compart
• Offer the ability to integrate a number of vehicle functions, such as cruise control, traction control and electronic stability control, without the need for additional hardware.
• Allow the vehicle designer to tailor throttle response characteristics to the vehicle.
• Can provide different, driver selectable, throttle response characteristics.

To the average motorist drive by wire throttles are virtually indistinguishable from mechanical systems of the past. Though occasionally some drivers may feel a certain disconnect between the position of the accelerator pedal and what the engine appears to be doing. This is simply the cars computer managing engine speed, torque or wheel spin through the throttle actuator.

Drive by wire systems are designed to always fail safe meaning that the engine will always return to idle or near idle if a fault develops.

Brake-by-wire is also possible. Electronically operated park brakes that can be applied with the touch of a button, and which automatically release when the vehicle moves off, are already in production.

In theory vehicles could even be equipped with steering systems that have no mechanical connection whatsoever between the steering wheel and the wheels.