A repository for a 4-wheel Skid Steering rover, based on Robotic Operative System ROS and Python to control the perception and action systems for autonomous navigation. Using Model Predictive Controller for follow the reference angle, Proportional error for speed and Kalman Filter to stimate the x,y position.
- folder with all ROS nodes Rover_ROS
- folder with codes from previous jobs Rover_resource
- Raspberry pi 3B
- RoboteQ Motor Controller HDC2450
- Xsens MTi-30
- GPS Ublox 3DR
- Encoders Autonics E50s-1500
- Control RC SPEKTRUM DX6i
- Receptor SPEKTRUM AR8000
- First download Ubiquity_OS in a micro SD preferably type 10 for a good performance
- Insert the micro SD in a Raspberry pi
- Open a Terminal with Ctrl + T and write:
sudo raspi-config
- In Boot options disable the GUI or graphical interface, this is the best option to get the optimal performance in a Raspberry Pi. When the raspberry restart only have the comand window.
In a terminal of Ubiquity, first create a catkin workspace folder
mkdir -p ~/catkin_ws/src
cd ~/catkin_ws/
catkin_make
After create the workspace folder, in a /src folder download the folders of this repository Rover_ROS that contain all the necesary elements to run the autonomous navigation of the Rover
sudo apt-get install htop
sudo apt-get install screen- Install gps_common as available based on the ROS distributable
sudo apt-get install ros-kinetic-gps-common- Install MTi rosnode
cd ~/catkin_ws/src
git clone https://github.com/ethz-asl/ethzasl_xsens_driver.git
cd ~/catkin_ws/
catkin_make
Xsens company now create his own node in ROS, to download them, first need download the MT Software Suit for linux and follow the instructions into a readme files.
Udev is a device manager for Linux that dynamically creates and removes nodes for hardware devices. In short, it helps your computer find your robot easily. By default, hardware devices attached to your Linux (Ubuntu) PC will belong to the root user. This means that any programs (e.g. ROS nodes) running as an unpriveleged (i.e. not root) user will not be able to access them. On top of that, devices will receive names such as ttyACMx and ttyUSBx arbitrarily based on the order in which they were plugged in. Luckily, you can solve this, and more, with udev rules in the web site of CLEARPATH. implement udev is used to identify the sensors or peripherals that are connected through the Raspeberry USB ports.
Some driver/software packages will already provide udev rules you can use. Check the /etc/udev/rules.d/ folder to see if there’s anything installed already. If the package is lazy and gives you a udev rule to install yourself, you can do this using
sudo cp <rule file> /etc/udev/rules.d/>
The matching part lets the udev device manager match the rule to the device you want. The manager will try to match all new devices as they get plugged in, so it’s important that the rule be specific enough to capture only the device you’re looking for, otherwise you’ll end up with a /dev/hokuyo symlink to an IMU. There are many potential matching tags, and the best way to pick the useful ones is to get all the device attributes straight from udev.
Run the following cammand, inserting a such as /dev/ttyACM0:
udevadm info -a -p $(udevadm info -q path -n <devpath>)
You will get a list of all device attributes visible to udev. looking at device /dev/ttyACM0
KERNEL=="ttyACM0"
SUBSYSTEM=="tty"
DRIVER==""
looking at parent device '...':
KERNELS=="3-3:1.0"
SUBSYSTEMS=="usb"
DRIVERS=="cdc_acm"
ATTRS{bInterfaceClass}=="02"
ATTRS{bInterfaceNumber}=="00"
looking at parent device '...':
...
ATTRS{idVendor}=="0483"
ATTRS{idProduct}=="5740"
... - The next function it's for move the Rover to place that want to do Autonomous navigation
function manual(){
/usr/bin/python /catkin_ws/src/rc_control/src/control.py &
sleep 10
/usr/bin/python /catkin_ws/src/main_control/src/mpc_controller.py
sleep 10
}
And this one it's for execute the algorithms necessaries for trajectory tracking.
function automatico(){
/usr/bin/python /catkin_ws/src/imu/src/imu.py &
sleep 10
/usr/bin/python /catkin_ws/src/gps/src/gps.py &
sleep 10
/usr/bin/python /catkin_ws/src/Roboteq/src/read_enc.py &
sleep 10
/usr/bin/python /catkin_ws/src/Roboteq/src/pos.py &
sleep 10
/usr/bin/python /catkin_ws/src/kalman_filter/src/kalman_bias.py &
sleep 10
}
The next picture is a map of all the nodes running on the system in automatic mode
For more information:
- Read the document here
Universidad de Ibagué - Ingeniería Electrónica