Autonomous cars, buses, vans

 Autonomous cars, buses, vans

In this section, we will consider autonomous cars as our example. Autonomous cars use sensors, cameras, actuators and microprocessors (together with very complex algorithms) to carry out their actions safely. Sensors (radar and ultrasonics) and cameras allow the control systems in cars to perform critical functions by sensing the dynamic conditions on a road. They act as the ‘eyes’ and ‘ears’ of the car.

Microprocessors process the data received from cameras and sensors and send signals to actuators to perform physical actions, such as:

» change gear
» apply the brakes
» turn the steering wheel.

Cameras catch visual data from the surroundings, while radar and ultrasonics allow the vehicle to build up a 3D image of its surroundings (very important when visibility is poor, such as in heavy rain, fog or at night).

Suppose an autonomous car is approaching a set of traffic lights which areshowing red. The first thing the control system in the car needs to recognise is the road sign, and then check its database as to what action to take. Because the traffic light shows red, the microprocessor must send signals to actuators to apply brakes and put the gear into ‘park’. Constant monitoring must take place until the light changes to green. When this happens, the microprocessor will again instruct actuators to put the car into first gear, release the brakes and operate the throttle (accelerator). This is a very complex set of operations because the microprocessor must constantly check all sensors and cameras to ensure moving off is safe (for example, has the car in front of it broken down or has a pedestrian started to cross the road, and so on).