Steer-By-Wire, Drive/Brake-By-Wire, Shift-By-Wire Systems Explained

Over the last decade or so, more and more automobiles have been getting dependent on the usage of electric components to run them. Almost every aspect of an automobile now relies heavily on electronic components like hybrid powertrains, electric powertrains, interiors, safety and much more. As automobiles are slowly moving towards the direction of autonomous driving, electronic components are going to be an even more integral part of a vehicle in the future. With autonomous driving, all aspects of the roads, safety and powertrain will be controlled by electronics.

The ECU is commonly referred to as the brain of the vehicle nowadays, apt given it is the most integral part. The ECU controls pretty much every aspect of how a vehicle functions and its raw computing power allows it to process information much faster than a human brain. Having an ECU also lets the vehicle have a multitude of features that are aimed towards the driver's comfort and convenience. Today we take a look at the importance of features controlled by the ECU like Drive-by-wire or Steer-by-wire and Shift-by-wire.

Steer-By-Wire

Drive-By-Wire is becoming increasingly common in vehicles in the current day and age. In older vehicles, the steering column connects to the wheels of a car through mechanical linkages and physical component. Now, the steering is instead connected to electrical connections like the cables, actuators, and pump which are connected to the ECU. A position sensor takes the driver’s input as to how much steering wheel has been turned and how much steering of the vehicle is required. The ECU receives the signal from the steer-by-wire system and sends out a command signal to the actuators that complete the action required to steer the vehicle.

Pros And Cons

There are quite a lot of advantages of having a steer-by-wire system installed in a vehicle. A system like this means lesser mechanical components to go through wear and tear, better maintenance ability, a lesser weight, the ability to install the steering column on any side of the vehicle, and more. A steer-by-wire system means the weight and feel can be changed by the press of a button to make it more sporty or comfortable.

Apart from the initial cost, there are not too many disadvantages of having a steer-by-wire system compared to an older system. Furthermore, as more and more vehicles adopt this system, the overall cost will go down as well.

Brake-By-Wire/Drive-By-Wire

A brake-by-wire system and a drive-by-wire system are fundamentally similar, but the specifics are different. There is a position sensor attached to the brake pedal that replaces the physical connection of the brake pedal with the brake assembly. The brake pedal connects to the sensor instead, which in turn is connected to the ECU. The ECU processes how much braking has to be applied to fulfil the driver’s demand and accordingly sends the signals to the actuator which then performs the braking duties on the vehicle.

Similarly, a drive-by-wire system also has a sensor, but this time it is connected to the throttle.  The sensor sends a message to the ECU which in turn calculates how much of the valves need to be opened. Both systems allow the vehicle to most of the work for you, and since these systems are connected to the vehicle’s safety suite, it keeps you safer as well.

Shift-By-Wire

Plenty of automatic transmissions now use shift-by-wire technology, the recently launched Citroen C5 Aircross’ gearbox uses one of these systems. Here, electronics are used to communicate between the driver’s input and the transmission of the vehicle. The gear changes accordingly to the throttle response of the driver, enabling smoother gearshifts compared to a mechanical system.

This was a short guide on the concept of steer-by-wire, brake and drive-by-wire, and shift-by-wire systems. We hope it came in handy for you to understand the systems and their uses in a modern vehicle.