THEME - Hard & Soft 1999 Sound Controlled Vehicle Project Aim
To design and construct a vehicle
that can automatically follow a path defined by four different sound sources. You will also design the sound sources. Vehicle Hardware
The vehicle will consist of a pair of geared DC
motors to provide propulsion and steering, a directional microphone to monitor the sounds, a DSP card to process and analyze these sounds and a motor card to provide adequate power for the motors.
ADSP EZ-KIT Lite DSP card - this is the main vehicle controller card, details of which are given in the Analog devices books provided.
Motor Driver Card is a custom made
board for the vehicle project and provides the following facilities: four high current outputs (6V/500mA) to control the two drive motors; generates a single variable pulse width modulator (PWM)
for motor speed control; provides two high current general purpose outputs (6V/300mA); provides a regulated supply for the microphone board. Software
A control program is required
which will monitor the signal received from the directional microphone, identify the different sound sources and drive the vehicle to each one in turn. You have complete freedom to design and
develop this software as you wish. You also have some freedom to design the sound sources. Simple sound recognition can be done by comparing the frequency spectrum to a set of known spetrum
patterns (templates) stored in memory. Each template would contain the key frequency components of the sound that represents a particular sound source. If a sound is found to match one of these
templates, then the corresponding sound source has been recognised. Software is supplied to assist with this, if you wish to use it. Another approach to sound source recognition would be to use
digital filters to analyze the sounds. You may wish to design a more sophisticated system. The pseudo-code below show in a simplified form the stages required for the controlled vehicle.
while (infinite) do
repeat
SampleSignal()
until Threshold()
Perform FFT on data
if
(* it is a sound source) then
Output appropriate data to motor port
end |
