Biorobotics Laboratory BioRob

Elmar Dittrich

"Modular Robot Unit - Characterisation, Design and Realisation"

summer internship 2004


The aim of this project was to develop a modular robot unit in real hardware. After several simulations have been done already by D. Marbach and B. Mesot it was on time to have some physical implementations. Contrary to the simulations one has to deal with multiple defiances:

Everything had to be done under the constraint of "cheap design" - because the price really matters when you want to have a hundred of them.

Therefore it is absolutely necessary to use as much off-the shelf products and parts as possible. We decided to use standard servos with a good price/torque - ratio. The other materials are pretty light-weighted (PCB-circuit-base and aluminum). The power comes from Lion-rechargeable-batteries which are used for several other projects in the lab. Even the aluminum-lever is a standard u-profile modified with some holes and cuts.

The setup consists of six-handmade modules and one control unit. The control unit represents FPGA-development-board and Bluetooth-device to communicate wireless with some host pc. The two wires leading from the modules to the board are providing the PWM signal for the servos and ground signal to have the same zero potential like the FPGA.

On the host PC are two possibilities to control the modules. You can run a Java-GUI developed by J.-P. Egger and modified to send the trajectories via the serial interface (RS232) to the Bluetooth device connected to the computer or to create any trajectory by an external program, like Matlab and write it to a file. This file can be transmitted in the same way like before.

Rico Möckel has just finished integrating all electronics, controller and Bluetooth on-board. Now we have fully autonomous modules in sense of power supply and communication.





Modules individual:

With two modules:

With three modules:

With four modules:

With five modules:

With six modules:

* interesting
** most interesting

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