India registered 441,534 cases of crimes against women in 2024, on average one every 72 seconds. Of those, 13,396 were in Delhi. When it happens on the street, help still has to come by road.
Source: National Crime Records Bureau, Crime in India 2024, published May 2026.What happens when she presses SOS
-
1She presses SOS
One button in the app. On the walk home she can also ask a drone to fly above her the whole way.
-
2The nearest drones lift off
Drones wait charged on rooftop docks across the neighbourhood. The closest ones take off together and split up the area her phone could be in.
-
3A camera finds her in the dark
The drone matches her to her phone and flags anyone following her.
-
4It comes down and lights up the street
Spotlight, strobe and a voice telling him he is being recorded. More drones arrive and keep filming from above.
-
5The control room calls the police
Her SOS arrives with her location and live video. An operator dispatches the police and stays with her until they arrive.
One button, or a drone for the whole walk home
Made for the walk from the metro, the hostel or a late shift. It speaks Hindi and English. If she can't answer, the SOS goes out by itself.
- Walk me homeA drone flies 35 m above her to her door.
- Someone's following youShe gets a warning before he reaches her.
- Help's comingShe and her family see each drone on its way.
What the simulation shows
| Measured | Result | How |
|---|---|---|
| Time for four drones to find her after an SOS | 3.2 min | Median of 5,320 simulated night incidents with a 200 m error in her phone's location, checked against six full flights on PX4 |
| People following her who are flagged while they follow | 91 to 95% | Usually minutes before contact. Groups converging on her: 25%. False alerts: 1.2 per escort hour on quiet streets, 2.6 in crowds |
| Ambushes flagged before contact | 68% | About 14 s ahead, on test walks generated after the design was fixed |
All three come from a 3.4 by 3.3 km model of Hauz Khas built from open map data, with drones running PX4, the flight software used on real drones. They have not yet been measured on real streets.
Built to protect her, not to patrol
- It flies when she asks
- A drone takes off for an SOS or an escort she started. It does not patrol the neighbourhood.
- The camera is there for her
- It looks for her and for anyone closing in on her. It does not identify faces or keep a record of passers-by.
- The video belongs to her case
- Recording starts with an alert and goes to her and the control room, as evidence for her complaint.
Who is building it
Prakash Aryan, founder
Robotics PhD researcher at the University of Bern, working on multi-robot mapping and teams of drones. Built Ratrik's simulation, from the flight software to the night camera.
Where we are
- The full response runs in simulation: app, rooftop docks, PX4 flight software and a mapped Hauz Khas.
- A person detector for night drone footage, trained on rendered streets.
- First night flights with a real drone.
- A pilot with one South Delhi neighbourhood.
Bring Ratrik to your street
Tell us where you live or work, so we know where Ratrik is wanted first.
You're on the list. We'll write when Ratrik flies near you.