Hardware Overview:
a) The mechanical system consists of two wheels driven by 12V dc motors.
b) A microcontroller (Siemens 80C535) is present on robot to control motors,input sensor data and communicate with PC via a serial cable.
c) An ultrasonic distance-measuring sensor is present for obstacle avoidance. The sensor is rotated to different angels by a stepper motor.
d) Two optical encoders are mounted on the wheel shafts to measure distance traveled and current speed of each wheel.

The Neural Network used is a simple feed-forward network, which not only controls the motion but also decides on the amount of sensory input required. The goal of robot is just limited to autonomous navigation in the direction where the obstacle is most distant. Thus, it forms a purely reactive system. (I had to put this modified reactive NN in PC and not in microcontroller, later).

Dimensions: Length: 46 cm; Width : 30.5 cm (excluding the wheels); Height: 30 cm;

The cost is US $100 ONLY because:
* The motors are second-hand; which I bought in junk market. (they are eep's viper motors; powerful , that the robot can carry 5 kg. easy; two motors for $6, nifty heh!)
* The optical discs are cut from lids of cookie jars.
* The wheels are from old tri-cycle.
and rest you can guess...

I have named the robot 'R. Daneel V4' after 'Daneel', a character in Isaac Asimov's novels. Asimov first coined the term robotics. 'R' stands for 'robot' following the nomenclature used by Asimov.

Problems: I'll tell you a funny one.

The ultrasonic sensor used doesn't detect cloth (coz its rough surface and the critical angel problem....). Thus a person standing in its way must be wearing Shorts !!.

Greetings.

Vivek Vaid