Advanced Robotics Fall 2015

Stewart Platform Fork

Code repository and issue tracker for the Fall 2015 of "Advanced Robotics" (Independent Study group)

http://correll.cs.colorado.edu/?page_id=3748

Stewart Platform

This repo contains the files necessary to build and control a Stewart platform.

Getting Started

This code uses:

Ubuntu 14.04
ROS Indigo

Setup the ROS Environment

Install ROS indigo if you haven't already: http://wiki.ros.org/indigo/Installation/Ubuntu

Setup environment variables:

		source /opt/ros/indigo/setup.bash

Setup the workspace:

		mkdir -p ~/stewart_ws/src
		cd ~/stewart_ws/src
		catkin_init_workspace

Install ROS Dependencies

sudo apt-get install ros-indigo-rosserial-arduino ros-indigo-rosserial ros-indigo-rosserial-server python-catkin-tools

Clone this repo into the catkin workspace

cd ~/stewart_ws/src
git clone <https://address>
mv advancedrobotics/ stewart_platform/

Build this workspace

cd ~/stewart_ws
mkdir src/stewart_platform/include
catkin build
source ~/stewart_ws/devel/setup.bash
sudo cp ~/stewart_ws/src/stewart_platform/dev_rules/*.rules /etc/udev/rules.d/
sudo udevadm trigger
roscd stewart_platform/

Make sure to unplug and replug the usb devices after running udevadm trigger.

Setup the environment variables to be sourced on startup

sudo gedit ~/.bashrc

Add these 2 lines at the bottom:

source /opt/ros/indigo/setup.bash
source ~/stewart_ws/devel/setup.bash

Running the Stewart Platform

Install Dynamixel Dependencies:

sudo apt-get install ros-indigo-dynamixel-motor

Make sure roscore is running. If not, run this command in a separate terminal:

roscore

In a new terminal, bring up the dynamixel servos:

roslaunch stewart_platform controller_manager.launch

In a new terminal(s):

Stewart Platform Test

You should see the motors move to the min range, max range, and then a neutral position when running this test. If they don't move, but you don't have any errors, try restarting everything. If you have errors, good luck!

rosrun stewart_platform stewart_ik_test

stewart platform math and instructions are here

Communication with Sparkfun Razor 9DOF IMU

rosrun stewart_platform stewart_accel_test

A Razor tutorial. Use this tutorial to calibrate the Razor.

NOTE Yaw will not be correct if the magnetometer is not set up properly.

You can view the data in a serial monitor tool, such as Arduino or PuTTy.

To use Arduino:

Install arduino from webpage, not distro.

rosserial_arduino Tutorials are here

Start Arduino

Change the Serial Port to the one that the Sparkfun Razor is plugged into by navigating to and changing Tools -> Serial Port -> /dev/ttyUSB#

Navigate to Tools -> Serial Monitor

Change the baud rate to 57600

You should see scrolling data that changes when you move the IMU around and that looks similar to:

#YPR=-157.65,2.94,-0.14
#YPR=-157.67,2.95,-0.15
#YPR=-157.69,2.95,-0.14
#YPR=-157.72,2.96,-0.13
...

Windows Dynamixel Manager

download the RoboPlus software from dynamixel

see this page for driver installation problems

Use the Dynamixel wizard to set up the servos. 2, 4, 6 need to be in the reverse direction mode. The files in this package assume the communication baud rate is (0x34) 57600.

Hardware Build Notes

Remember to wire up the servos before installing them
Add a laser cut hole to bottom of servo stands for easer cable routing
Ensure servo horns are aligned to the zero position.
Make all bars the same length and command servos to same position before installing the upper plate.

Jorge-C/advancedrobotics