Robo Madge-Ellen A Mid-Sized Bot With Inside Navigation

This is a mid-sized 'floor bot'  based on a Raspberry Pi 3 on Ubuntu Linux and running the ROS or Robot Operating System as it's base robot OS.   This bot sports a Lidar unit (360 degree Laser distance device) seen on the top of the picture that allows detection of nearby objects including walls.  In the picture below we see Madge Ellen  with the spinning Lidar unit on top (with classic time tunnel pattern on top). 
Robo Madge Ellen
(Click Picture And go 17min 30 sec in for nice video of this bot)
Robo Madge-Ellen A Mid-Sized Bot With Inside Navigation

The drive motors have the added advantage of having magnetic encoders on them are are driven now by a RoboClaw drive controler for precise wheel control with ability to travel precise distances or rotate precise angles.

A brief introduction of Madge-Ellen to the Home Brew Robotics Club can be seen at 17min 30 sec into  this video  and I hope to soon link to the demo of the version shown below for the Jan 2016 meeting.

Near July of 2017 at a Home Brew Robotics meeting it wandered around in an enclosed space and navigated to different locations on it's own to show it's navigation skills.

This bot has done a couple phases of the Home Brew floor bot challange in that it has gone on it's own from one side of the room to the other and has found and moved to an object that had what is called an AR Tag on it  (AR tag is a blocky symbol looking a lot like codes seen on products)

This bot also has  GPS and a Compass and understands high level commands like face a given heading or face a given waypoint.  The bot has a WiFi access point and bluetooth joystick control as well as a a webcam that feeds  OpenCV visual recognition routines which can identify at this time an orange traffic cone.

Subsystems used on Robo Madge-Ellen

Proximity Sensor Module
An 8-sensor proximity subsystem that keeps track of 8 separate ranges at angles of 45 degrees apart is used in this robot.   See this  Arduino Nano controlled set of 8 VL53L0X time of flight sensors on the Robotic Subsystems page on this site.

RoboClaw Used with base_control Node
An RoboClaw 7-amp dual motor controller with wheel encoders is a key element to precise movement and wheel odometry for this robot.

Software done by Mark-World includes modifications of the serial driver code found elsewhere for a robust checksum based protocol.  See more detail on the Robotic Subsystems page on this site.

The Neato Lidar Laser TOF 2D range finder Spins on Top
A popular 2D navigation subsystem is the black Neato Lidar unit sitting on top which spins around and offers 360 points of distances so the bot can map and navigate a room.
This is a key and important feature and is a lot of fun as well!
The Neato Lidar uses a getSurreal controller and the xv_11_laser_driver ROS node

Webcam With Pan Tilt Using Mark-Toys Servo Control Subsystem
A webcam that is wired into ROS allows this bot to 'see' and can be used in the future as was done on FiddlerBot (seen on these pages).   The green board under the cam set servo pan-tilt.
Orange road cone detection software done using OpenCV is all that is done at this time.

Navigation Visualizaion Tool

A nice picture that shows a tool called  RViz in a screen shot showing many ROS constructs all in one picture.

This tool runs live so you can see the bot move about and objects change it's perception of the detections.

The bot itself is called a  URDF format model and Rviz shows it to scale where it happens to be in the room.

Robo Madge-Ellen has the Lidar that allows the bot to know where walls are and you see those in this picture as the multi-colored dots at the edges.

Next the navigation software makes a 'map' and that is shown in this tool as the gray area with black outline.

Then the proximity sensor shows the cones of detection for 8 sensors that you will note end about where the walls are and each cone shows the spec for the detection cone.

RoboMadge-Ellen URDF Model

The Model in RViz is made in a special language in text and then is rendered into RViz using the location and orientation or pose of the robot at any point in time.  A closeup of just the URDF model is to the right and notice the clear plate is also present.
Display Board Uses  Mark-World ROS node for Serial LCDs

A serial interface to the multi-line LCD display uses a ROS node that can allow the bot's main node to write out status and other messages to be read by humans.

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Robo Madge-Ellen