Advanced rider assistance systems (ARAS) are mostly warning systems for people who ride scooters and motorcycles. They are the two-wheeler form of driver assistance. A typical warning tells the rider that a vehicle is in the blind spot, or that a vehicle ahead is too close.
A car has a body around its passengers. A rider has nothing around them. So a warning that arrives a second earlier matters even more on a two-wheeler. India is one of the world's largest markets for two-wheelers, so this is a natural place for Indian start-ups to begin. They build systems with smaller sensors than a car uses, and these must fit into a small space on the bike.
Say a rider in Coimbatore is following a bus at 50 km/h. The bus brakes suddenly. A small radar at the front of the motorcycle sees that the gap is shrinking fast. The system flashes a warning on the bike's display and sounds a beep. The rider gets a little more time to brake than he would have had otherwise. Most such systems only warn the rider. A few costly large motorcycles also have adaptive cruise control, which uses the radar to slow the bike when the vehicle ahead gets close.
The system uses the same types of sensor as a car, described under cameras, radar and lidar, but in smaller sizes. It must also be reliable, so it follows the rules of safety certification. A false alarm is a particular problem on a bike, where a sudden beep can startle the rider.
A two-wheeler is also harder to help than a car. A car can brake hard and stay upright. A motorcycle that brakes hard in a bend can fall, so the system is careful about doing more than warning. Two-wheelers are also bought on price, so the sensor and its computer must cost far less than a car's.
Electric scooters are a good place for it, because they already have a screen and a connected computer. The pairing with electric two-wheelers is natural, since their makers write their own software and can update it. The warnings show on the instrument cluster.