Driverless Cockpit Backend

Backend application for municHMotorsport's driverless monitoring tool. It acts...

...as an interface for client applications to access live data from the vehicle.
...as an API that offers recording functionality and handles caching, persistence and retrieval of recorded data.

Setup

System requirements

Node.js v6.2.2 or higher
Bower
MongoDB v3.2.3

Preparations

Dummy Data

The current version of Driverless Cockpit does not support network connections to a real car. It therefore relies on previously generated mockup data that is stored in a CSV file on your local machine. The structure of the file must look like this:

timestamp [s]	steeringWheelAngle [rad]	pathMiddleLineX [m]	pathMiddleLineY [m]	vehicleX [m]	vehicleY [m]	vehicleVX [m/s]	vehicleVY [m/s]	vehicleYawrate [1/s]	frontwheelLeftAngle [rad]	frontwheelRightAngle [rad]
0	0	2.0992	-0.052198	0.94976	-0.019921	0	0	-1.45E-11	-4.79E-08	5.40E-08
0.1	-0.67156	2.0993	-0.0522	0.94973	-0.019889	-0.00028446	0.00041255	3.09E-05	-0.25194	-0.26369
0.2	-0.17308	2.1296	-0.053375	0.97837	-0.021429	0.69818	-0.022324	-0.0301	-0.066667	-0.064819
0.4	-0.0634	2.4972	-0.068916	1.3454	-0.034595	3.0327	-0.03397	-0.048808	-0.026019	-0.022221
...	...	...	...	...	...	...	...	...	...	...

Download a sample file here.

Important: You must specify the path to the file on your local machine in the environment variable FSD_MOCKDATA_PATH.

MongoDB instance

Make sure you have a running mongod instance on standard mongo port: localhost:27017 before attempting to start the app.

Optional: Cache length

When recording data, each timeframe is cache in-memory for 30000 ms (30 seconds) by default. Change the cache length by setting the environment variable FSD_CACHE_TTL to an integer value (in ms).

Run the app

Start the app by hitting npm start in the app's root directory.

Access the API at http://localhost:3000/.

API Documentation

`GET /appstate`

Returns information about the current status of the application:

{
	"activeRecording": null || {		// null if no recording active
		"id": <ObjectID>,				// ID of active recording
		"start": <Integer>				// start of recording (epoch timestamp)
	},
	"connected": <Boolean>,				// is app connected to car?
	"recording": <Boolean>				// is app currently recording?
}

`GET /livestats`

Returns the last timeframe the car has sent. Example:

{
	"timestamp": 1521115708789,
	"steerAngle": -0.27185,
	"pathMiddleX": 16.692,
	"pathMiddleY": -6.0516,
	"vehicleX": 16.311,
	"vehicleY": -4.8649,
	"vehicleVelocityX": 9.8645,
	"vehicleVelocityY": -0.3053,
	"vehicleRotation": -0.6226,
	"frontwheelLeftRotation": -0.10325,
	"frontwheelRightRotation": -0.10341
}

`GET /recording/start`

Start a new recording. Returns:

Application status object similar to /appstate if recording started sucessfully
HTTP 500 error if something went wrong

`GET /recording/active/:since`

Get all frames newer than :since of active recording.

Params

:since - epoch timestamp, usually the newest timeframe your client app has received

Returns

{
	"id": <ObjectID>,						// ID of active recording
	"start": <Integer>,						// start time of active recording (epoch timestamp)
	"chunk": {
		"first": <Integer>,					// timestamp of first frame included in response
		"last": <Integer>					// timestamp of last frame included in response
	},
	"frames": [								// frames as in /livestats, sorted ascending by timestamp 
		{
			"steerAngle": 0.38624,
			"pathMiddleX": 11.741,
			"pathMiddleY": 31.235,
			"vehicleX": 12.93,
			"vehicleY": 30.466,
			"vehicleVelocityX": 9.5709,
			"vehicleVelocityY": 0.43311,
			"vehicleRotation": 0.95815,
			"frontwheelLeftRotation": 0.14871,
			"frontwheelRightRotation": 0.14665,
			"timestamp": 1521116122009
		},
		...
	]
}

`/recording/stop`

Stop active recording. Returns:

Application status object similar to /appstate if recording stopped sucessfully
HTTP 500 error if something went wrong

`/recordings`

Returns a list of all recordings stored in the database.

[
	{
		"_id": <ObjectID>,				// ID of recording
		"start": <Integer>,				// start time (epoch)
		"end": null || <Integer>,		// end time (epoch)
		"writeActive": <Boolean>		// true if this is the active recording
	},
	...
]

mgschoen/driverless-cockpit-backend