ADAS, on the Way to Driverless Cars
Have you ever imagined a fully autonomous car in which you are able to sleep while driving? This possibility is nearer than you could expect. Advanced Driver Assistance Systems (ADAS) is a novel research field whose main purpose is the so called “Active Safety”. Some of these technologies which are more likely to attract our attention are: parking aid, Adaptive Cruise Control (ACC) and Lane Keeping Assistance System (LKAS).
During the last decade, the automotive industry has been trying to enhance vehicle safety. It is offering intelligent assistance systems in order to reduce the number of fatal accidents that daily happen around the world. Drowsiness and driver inattention are two of the main causes of accidents. Hence, the majority of those systems improve active safety systems by overlapping driver manoeuvre in case of danger situation. However, and due to the present regulation, active systems are able to take the vehicle control only for a few seconds.
Currently, the trend in terms of active safety systems is to increase the level of vehicle autonomy. Lane Departure Warning (LDW) and Lane Keeping Assistance System (LKAS) try to maintain the vehicle within the lane, especially under unintended lane departure conditions caused by either lack of a driver’s attention or drowsiness. These systems enhance the vehicle safety as well as improve the driver comfort and handling. In order to achieve those purposes it is necessary to implement some devices such as radars, Lidars and cameras which allow LDW and LKAS to actuate accurately with a low level of uncertainty.
Regarding the Lane Departure Warning technology, it is an active safety system that prevents the driver to have an accident because of an unintended action or drowsiness. The system is able to recognise the lane on the road and make the driver aware of the lane departure situation. The driver receives a warning from the system in order to maintain the vehicle within the lane road if any unintended manoeuvre happens. Different kinds of warnings are used in LDW such as handwheel vibration, seat vibration at high frequency or a whistle that allows the driver to retake the manoeuvre.
Lane Keeping Assistance System is a novel technology, which assists the driver to actively maintain the vehicle within the lane. The way that this system performs is applying a certain torque to the steering system. There are two possibilities of LKAS activation; either the driver may switch on this manually or it is attached to the Adaptive Cruise Control (ACC). Due to legal requirements that limit autonomous features, the system can be overridden by the driver whenever the driver wants. The LKAS system can vary depending on the control variable.
The system layout, comparing LDW and LKAS, is approximately the same considering those sensors. However, in LKAS there is an actuator (Electric Power-Assisted System) that applies torque to the steering column when it is required. The ECU will also receive the curvature of the road as input. The distance between the car and the lane boundary and the heading of the vehicle is calculated in order to send the proper information to the actuator. The majority of the current LKAS system uses cameras to recognise the lane marker.
I hope that this post may be useful for your learning, and remember you don’t have to worry if you are a car lover, those technologies won’t substitute the sensation of driving along a highway or through a twisty mountain road. ADAS makes your drive safer, that’s all!