Design And Implementation Of Automatic Test System In Semi-free Field Anechoic Chamber

Acoustics audio products used in the culture media, automobile manufacturing, daily life, entertainment and other fields more and more widely, in order to ensure the accuracy and reliability of these enormous quantity of objective quality audio class device parameters, companies should make these products timely detected, its sound quality parameters to ensure accurate, true and unity. In order to ensure the accuracy and reliability of the semi-anechoic chamber freefield sound field characteristics of Acoustics developed a semi-automated test system for free-field anechoic chamber to verify the acoustic characteristics.The system consists of a stepper motor control software development side, the sound source signal control terminal software development, software controlled automatic acquisition function, automatic storage function of the software control, automatic data processing functions of the software control, automatic generation of the original recording function calibration software control, automatic generation of calibration certificate software control functions to design and implementation of several parts. The main idea is through the programming between the stepper motor and MP451 module to establish contact between the two, the control terminal of the stepping motor can complete the initial free-field microphone positioning, step length setting, integration time and other functions. Establish a sound source emission, closed relationship between the state and the stepper motor displacement, and can be at the computer SPL sound sources, emission frequency, response time, the display setting unit, the voltage amplitude and other parameters; through software Danish B & K(Brüel & Kj?r) 3560 C multifunction sound analyzer can perform automatic measurement functions timely according to the working status of the stepper motor, so that the entire semi-free field measurement process automation anechoic chamber. By program end data acquisition software enables data received in real time are automatically stored in the cache and dump PULSE computer’s memory, to prepare for the test data post-processing. By the sound of the multipurpose software analyzer can automatically read the data stored in the system before, and in accordance with the programmed data processing of the data analysis and processing, to obtain a final measurement result and stored.