How do accelerometer & distance sensors in drones work?

The accelerometer in the drone measures changes in acceleration and then forwards this information to the drone's flight controller, which uses it to adjust the speed of the propeller to keep the drone stable in flight.
Accelerometers also provide feedback on user movements such as tilting or pushing, allowing users to control the movement of the aircraft more accurately and efficiently. In addition, they provide altitude change data so that the aircraft maintains a set altitude during flight.

Distance sensors use a combination of different sensors to detect obstacles and measure distances. This includes infrared sensors, ultrasonic transducers, stereo cameras and laser rangefinders.
The sensor also allows the aircraft to accurately measure the distance between objects, which helps it maintain its course.