Warwick Engineering ES410 Group Project - Group 13
Repository to contain all of the code across 3 devices:
- Raspberry Pi: the on board companion computer
- Arduino: the on board microcontroller
- Ground Control Station: a laptop based on the ground
Describes the high level behaviour of the Drone.
| Colour | Behaviour | Description |
|---|---|---|
| Pulsing | Script is running | |
| Flashing (every 1s) | Data logging is active | |
| Flicker | TX activity to ground control station | |
| Flashing (for 5s) | Error, current script aborting and putting drone in idle |
Drone tries to establish connections to other parts of the system. A variety of messages sent. If successful, final message reported is Initialisation successful.. If initialisation fails, failure reported then the python program exits. Decided not to reboot else might get stuck in an endless cycle where we can't do anything with the pi.
On entry: Drone is idle. Waiting for command.
| Command | Description | Expected response |
|---|---|---|
shutdown |
shutdown (power off) drone | Drone is shutting down. |
reboot |
reboot drone | Drone is rebooting. |
mission† |
enter mission mode |
† After mission command, mission details must be received within 5 seconds. Details should be sent as a json with the following keys.
| Key | Data type | Comments |
|---|---|---|
| title | string | used for log title |
| location | string | a valid name from locations.txt |
| altitude | int | the mission altitude in metres |
Once the drone receives the mission, it processes it, saving and distributing the necessary parameters. Upon completion, Mission processing finished. is returned.
Battery must be connected in 20 seconds. When a voltage is present, drone reports Battery connected.. GCS must confirm battery has been secured in a further 20 s with command battery secured. Drone reports Battery loaded.
Parcel loading must be initatied within 30 seconds. Once button is pushed this will start the grippers closing. Grippers are to stop closing according to current sensing. Completion confirmation from drone is Parcel loaded..
Currently just gets this from pixhawk, unsure if further checks should be done
| Result | Return |
|---|---|
| Checks Passed | Drone ready to arm. |
| Checks Failed | Arming check failed. |
Currently if the checks are failed, the drone aborts the mission. This should be changed to allow recheck.
Switch must be pressed within 30 s
| Description | Message sent |
|---|---|
| On state entry | Waiting for hardware safety switch to be pressed. |
| When switch pressed | Switch pressed. |
| Timeout | Switch press timed out. |
Between states (after switch is pressed) a pause of 5 seconds happens to prevent immediate arming of the drone.
Authorisation must be received within 30 s. Send takeoff to authorise flight.
| Description | Message sent |
|---|---|
| On state entry | Waiting for authorisation to fly. |
| Authorisation message received | Authorisation received. |
| Timeout | Authorisation window timed out. |
Drone reports once a second containing current status.
Drone will fly to destination and report Drone landed. once it has landed on the target. The grippers will then release the parcel (see next section). The drone will then upload the return flight and automatically take off. Once drone lands back at base, Flight complete. Drone at home. is reported.
On entry: Releasing parcel.
On completion: Parcel released.
Using the Ground Control Station (GCS) is a trivial task on the whole because the program prompts the user for particular responses. Where commands must be entered, these are the same as required to send to the drone (detailed in 'Drone' section of the user guide). A few notes are contained below for the developer and which explain certain behaviour of the program.
The software currently doesn't handle drone timeout messages. The message will be printed to the command line but the program is then stuck in an infinite loop. This is undesirable behaviour which should be rectified.
Typically sends GCS program back to drone idle state but relies on the drone to timeout rather than sending an abort message. Program edited so GCS appropriately handles the waiting.