Concepts | 360 degree proximity Sensing - Quadcopter


The project will be investigating the best method of connecting our 360 degree proximity sensor to a UAV / Quadcopeter flight controller to enable partly autonomous and supported flight control,; such as using audible telemetry feedback.

Exploring the Frsky interfaces

S.BUS interface

The S.BUS enables a daisy-chain of servos and other sensors to be connected together in a UAV / Quadcopeter or other model with a single cable. This reduces the need to have individual cables & wiring-looms connecting to each servo. The S.BUS supports up to 16 channels - so via a microcontroller (such as the Arduino or PIC) it can be used for for triggering also other devices; such as lights, soft switches,PWM servos, etc. The S.BUS interface is now supported on many receivers e.g. from Futuba, FrSky, Pixhawk, etc and is also now supported by most flight controllers.

One method being reviewed, is by parsing the S.Port, RSSI, and/or the S.BUS signals interfaces according to the short range sensing of obstacles detected. So, if an object is detected, e.g. in the direction of the UAV, warning signals can then be sent back to the transmitter, in the same way audio feedback is given when reversing a car in a car park.

Another method is taking more control of the quadcopter and automatically making flight adjustments accordingly to the direction of the obstacle.

In the 1st phase of our project we'll probably be using an Arduino mini to interpret the S.PORT and S.BUS and the 16 channels provided. A soft-channel will be setup for switching this autonomous functionality on or off.

We'll start to focus on autonomous hovering and short-range obstacle avoidance (such as ground obstacle, walls, ceilings, and trees, etc). We'll parse channel 1 - "thrust" to automatically control the hovering of the drone. Other directions will then be investigate over time,

We'll also use the Arduino mini for direct control of other sensors or actuators on the drone, such as turning LED's on and off , buzzers, sensors, telemetry, control of standard PWM servos.and also for direct control from the Transmitter. We are also reviewing the bi-direction data transfer from the Taranis serial port.

We'll also review direct connection of the 360° sensor to the receiver and fllght controller.

We are grateful to ARMmbed for providing details of this protocol and many others who have contributed to documentation, videos and who have already converted the S.BUS to Arduino sketches.

S.BUS Visual Simulator

To simulate the results of the S.BUS we have build a sketch to visualize each channel of the S.BUS protocol. The sketch is Java based and almost identical to the Arduino java script; so this was relatively easy to convert to a processing sketch. See the following section for more details.