Sunday, 30 October 2011


Now that the base construction is complete its time to add all the functions back in
like arm movement, navigation and the AI. The previous arm was to low to the ground to be useful so this time we will raise the arm higher in the torso where we will add equipment like speakers , microphones and other parts with out the need to dive into the base

Stage 1 complete

Over the weekend we completed stage 1
  • The motors are wired and working
  • steering works but still need making more robust
  • We had to rewire the encoders to use ports they work but not in the program
  • we added the torso mount and the kinect
After a couple of test we were ready for our first run,  Robbie was making good speed with smooth acceleration and no belt slippage   steering is a bit off to the right. The steering encoders are a bit agricultural they need groves to hold the o ring and the correct size o ring. The wiring around the pod bays need to be cleaned up and tied back to stop wires getting snagged. 1 thing i have noticed is the base seems stable when transitioning from forwards to reverse (I felt there might be some wobble in the caster legs).

Sunday, 23 October 2011

Omni Base Update

The original idea of routing the motor wire over the side was not going to work so using PVC pipe fittings I made a hollow shaft to pass the wires. The streeing encoders will now be shifted to the side and be belt driven .
Things to do before first test
Fit steering encoders
secure PC cards to stop wobbling
secure VGA plug
tidy up wireing

Monday, 17 October 2011

Omni Base update

All the drive motors were fitted to the casters and the computer was installed in the base a new power board was made. I made the sides to fold out to make is easier to work on the parts the left side holds the arduino annd motor controllers the rear holds the switch board the right side has access to the computer rear conectors
and usb hubs.

Tuesday, 11 October 2011

Python program

The program is based on the Arduino mega with a python interface using a xbox 360 wireless controller
The streering system uses 2 HB25 motor controllers for and aft there 2 1K pots for controlling the wheel position. The 4 drive motors are controlled by 1 polou dual VNH2SP30 motor driver with encoders for the front wheels to start with. the joy stick control is throttle  left and right ackerman steering with the rear opposite to the front and a straffe mode to move side ways

Sunday, 9 October 2011

Omni Base 2

The base has the casters install and the first steering drive is installed the steering  motor is 160 RPM and 25 Kc/cm torque the speed is to slow but it will do for now.

Wednesday, 5 October 2011


The base is starting to take shape I turned the drill press into a wood lathe to make the bearing spacers and end caps. The new base is stronger than the first and much lighter. The outer race of the bearings will be held in place with epoxy to remove the alignment problems of the first base. The first caster is only missing the encoder. For reference the axle bolt goes in the other way to make fitting the encoder easier 

Sunday, 2 October 2011


Over the last few days i started constructing The first prototype type caster. One of the main problem has been accuracy small alignment issues cause the casters wobble but that aside movement is smooth i may need to add a slip mechanism to the top of the casters for alignment or make all wheels steerable