Design Of Vehicle Loudspeaker’s Vibration Signal Acquisition And Analysis System

Nowadays people have more and more stringent requirements about the sound andvibration characteristics for automotive accompanied with the bloom of economics. Asthe unique method of communication with the outer space, the vehicle loudspeaker’sfrequency and vibration intensity are required to meet certain requirements. But thestrong body vibration intensity of loudspeaker is inconsistent with the anticipation ofquiet and smooth driving environment. Therefore, vehicle manufacturers need to find abalance between the performance of loudspeaker and its bracket vibration, and theyhave an urgent expect for a professional acquisition and analysis system for the bracketand car body vibrations.Meeting the requirements of manufacturers together with the needs of testingalgorithm in laboratories, we design two complete sets of vibration acquisition andanalysis system. The first system takes the DSP chip of TMS320F2812as the core,supplemented by the acceleration sensor at the front, and signal conditioning modules.We design a user operating platform on PC with Visual Basic6.0developmentenvironment to achieve a complete vibration acquisition system. Second system isbased on Agilent U2331A data acquisition modules. It makes use of MATLAB GUIinterface and adds a variety of signal analysis methods, which is a complete system ofsignal acquisition and processing.The two systems are complementary which both have the individual strength aswell as weak points from the hardware design, cost and the difficulty of realizingdifferent algorithms. The first system finally realizes the primary functions of vibrationsignal acquisition, storage, and displaying the results. The second system comes to thecomplete implementation of signal acquisition and processing with varieties of analysisalgorithm both in time and frequency domain. The two systems make the ends meet,both of which can offer accurate and reliable results of the vibration. In the test ofsecond system, the results are compared with the loudspeaker’s driving signal which isaccurately matched. The algorithm used in the system, such as the acceleration signalintegration, power spectrum estimation is ideal.New analysis algorithms and functions can be tested in the second system andrealized in first system to form portable and economic vibration analyzers. Completionof the subject has important significance in testing the vibration of loudspeaker’sbracket and car body which makes contribution to accumulating experience and hasbrilliant economy and research value.