THEME - Hard & Soft 1998
Voice Controlled Vehicle Project
To design and construct a vehicle that can be fully controlled from human generated sounds.
The vehicle will comprise of a pair of geared DC motors to provide propulsion and
steering, a microphone to monitor any sounds, a DSP card to process and analyze these sounds and a motor card to provide adequate power for the motors. Five 1,5V batteries will provide the power source.
The main vehicle card is an ADSP EZ-KIT Lite DSP, details of which are given in the Analog Devices books provided.
The 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. The board is IO mapped as an eight bit output port.
The Microphone Board
amplifies the input from microphone to a suitable level for the codec input of the DSP card.
A control program is required which will monitor any sound produced, and compare them to a
set of known sounds stored in memory known as templates. Each template contains the key frequency components of the sound that represents a particular command. If a sound is found to match one of these
templates, then the appropriate signal is sent to the motors and the vehicle reacts to the command.
The pseudo-code below show in a simplified form the stages required for the controlled vehicle.
while (infinite) do
Perform FFT on data
if (* it is a command) then
Output appropriate data to motor port
It provides the basic framework from which the contestants can develop their software.
- Program editor, assembler, linker
- EZ-Kit Lite Monitor (program that control the DSP card)
- Testout (test operation of motors)
- Sample & Instant (signal capture and FFT)
- library subroutines for normalisation, filtering, windowing, scramble, FFT, motor control
The vehicles built during the contest were tested on a special track, the contestants controlling them by human generated sounds. The marking criteria were the time necessary to arrive at the ending point following the track, the number of mistakes made by trespassing the track etc.