Capstone

Lawn and Order - Collection of Code, Resources, Docs, and Static website for UVA ECE Capstone

Initialization

Prerequisite
Working Redis Server on static IP that is known to all devices.
1. Map/Boundary is Set
User sets boundary position vectors for the work area.

2. Robot Comes Online
Once robot connects to central WiFi node, it is responsible for connecting to RedisDB and publishing it's unique identifing marker (UID) and name to channel fieldObjects. The robot will then subscribe to a channel entitled fieldBot-<UID>. It will recieve position vector on this channel.

3. Navigation Server
The navigation server must get from map-configuration to receive up to date boundary position vectors and subscribe to system-updates to receive updates whenever the map is changed to then pull from map-configuration. Each object will come from CV server with a UID, which is read from marker on the robot. That UID will dictate which channel navigation info will be published to.

OpenCv
No configuration necessary.

Communications (subject to change)

Redis based message queue. There are three actors in the current network:
1. Computer Vision Server
Input: Video Feed of field
Output: Publish, JSON Object describing field
2. Navigation Server
Input: Subscribe, JSON Object describing field
Output: Publish, Robot Specific message containing position vector and theta angle
3. Robot
Input: Subscribe, message with postition vector and theta angle
Output: Publish, error messages
4. UI
Input: Subscribe, Current Application State
Output: Publish, field boundaries/Application Configuration

Message Channels and Structures

Field Objects

{
    message: {
        objects: [{
            uid: 9183,
            position: {
                x: 412.4,
                y: 1235.9
            },
            angle: 358.8
        }]
    },  
    time: 12341234,
    sender: "cv-server"
}

Robot Directions

{
    message: {
        objects: [{
            uid: 9183,
            position: {
                x: 412.4,
                y: 1235.9
            },
            angle: 358.8
        }]
    },  
    time: 12348030,
    sender: "navigation-server"
}

WebSockets

1. install MQTT Mosquitto
2. modify /usr/local/etc/mosquitto/mosquitto.conf by adding:

listener 1883 127.0.0.1  
protocol mqtt  
listener 11883 127.0.0.1  
protocol websockets  

3. Run using /usr/local/sbin/mosquitto -c /usr/local/etc/mosquitto/mosquitto.conf