Bentley mk2

We have decided to continue with Bentley but with some changes. The omnidirectional base has been replaced with an old rover 5 base. I had laying around the main advantage is the wheel encoders. We added a laser scanner above the raspberry pi for localization. And some of the servos have been replaced with better ones. with the new lipo battery, the run time is over 5 hours next is calibrating the drive system and localization. 

Bentley update 7/7/18

There have been a few changes since the last update.
The radio control has been removed due to it being unreliable.
The Omni base was changed to a differential control.
A Raspberry Pi running ROS is used for control.
The Omni base had one really major problem the motor gearing was too high the RPM should be around 50 RPM these were 200RPM. with tight wheel angle, the motors would stall due to lack of torque increasing the power resulted in a jerk and rapid movement. The cheap motors were structurally week and flexed this was a bonus as it acted like a suspension. When we swapped the Omni base for a differential drive with wheel encoders, the movement problems came down to tuning. The cheap servos I had laying around are very noisy and tend to jitter they will need to be replaced with better one if this project continues

bentley

I always liked Dickels MD#3, but I don't have the time to craft it out of styrene, so it's mostly printed and uses left over parts from other robots. The base was an idea to make a small omni directional drive with small servos for steering and encoders and cheap motors for the drive. There wasn't enough space in that design. Now its the right size base for the MD#3 body I replaced the stepper motors with mini servos that reduced complexity. I had some 3.2-volt lithium batteries from another project I run the motors on a  6.4 volts battery pack and the Arduino on the 9.6-volt battery pack to reduce noise
Bentley has 3 Arduinos
a Due in the base to control the steering servos and drive motors
2 Arduino pro minis  in the chest for the servos
I use I2C for comms between the arduinos.