THE PROPOSED EFFORT IS TO ANALYZE, DESIGN AND CONSTRUCT AN OPTICAL RANGING SYSTEM TO BE USED AS A COLLISION AVOIDANCE SENSOR.

THE PROPOSED EFFORT IS TO ANALYZE, DESIGN AND CONSTRUCT AN OPTICAL RANGING SYSTEM TO BE USED AS A COLLISION AVOIDANCE SENSOR. WHILE LASER RANGERS HAVE BEEN USED BY THE INDUSTRIAL AND MILITARY COMMMUNITIES FOR MANY YEARS, THESE DESIGNS ARE FOR APPLICATION DIFFERENT FROM THE COLLISION AVOIDANCE AND THEREFORE MORE COMPLEX AND EXPENSIVE. THE PROPOSED DESIGN USES A GAAS LASER DIODE WHICH IS CAPABLE OF VERY SHORT OPTICAL PULSES AT A PULSE RATE SO THAT THE POWER CONSUMPTION IS LOW. THE PROPOSED SYSTEM IS SCANNED IN ONE AXIS SO THAT THE SPACE IN FRONT OF THE ROBOT IS SAMPLED AT MANY DIFFERENT BEARING ANGLES. THE SYSTEM COULD EASILY BE EXPANDED IN THE FUTURE TO SCAN IN BOTH THE AXIMUTH AND ELEVATION. THE VERY NARROW BEAM AND NARROW PULSEWIDTH OF THE LASER RANGER WILL PROVIDE GOOD OBSTACLE DEFINITION. THE PROPOSED RANGER USES A SIMPLE ANALOG TECHNIQUE FOR MEASURING RANGE WHICH YIELDS HIGH ACCURACY AND ELIMINATES THE ULTRA HIGH FREQUENCY DIGITAL COUNTERS AND CIRCUITRY WHICH ARE COMPLEX AND CONSUMES MORE POWER. THE USE OF OPTICAL FIBER DELAY LINES WILL ALLOW THE SYSTEM TO MEASURE TO ZERO RANGE AND ELIMINATE THE ELECTRICAL INTERFERENCE BETWEEN THE TRANSMITTER MAIN BANG AND THE SENSITIVE OPTICAL RECEIVER.