Design And Development Of A Kind Of Watch-testing Instrument

Watch-testing instrument is an integral part of watch industry, its main role is to ensurethe quality of watches by test various components an finished watches accord with qualityindicators. There are a lot of types of testing instruments, which the most widely used isinstrument calibration, and this paper is mainly based on instrument calibration.In this paper, a design of calibration device can get the instantaneous daily rate of themechanical watches by watch sound sampling and processing is proposed, which is based onDSP. DSP core of the system is responsible for data acquisition, calculation and control of theperipheral circuits, including the Variable-Gain Amplifier circuit, filter circuit, externalAnalog-Digital conversion conversion circuit and liquid crystal display module. The design ofhardware and software of system were introduced detailedly. Hardware design includescapability of IC, circuit architecture and functions. Software section described principle andrealization of two algorithms, including counting and cross-correlation. Counting algorithm tocalculate the sampling points, the signal interval obtained by the sampling points andsampling rate, then calculate the instantaneous daily rate. Cross-correlation algorithm has animportant feature, that is, if the same type of signal x (t)and y (t)delay, then the size of thedelay between two signals can be used cross-correlation function accurately calculated, thisfeature makes the cross-correlation functionwidely used in engineering measurementtechniques. The two algorithms using Matlab simulation, comparison of the two algorithmsfor the calculation of the same signal, the cross-correlation algorithm for calculation accuracyis significantly improved. DSP calculating and the peripheral circuit of controling werepresented.Finally, the paramenters of the system were measured. Analysing the test results, papermakes some conclusion for improvement. The system has merits of portable, small size, lightweight and low power consumption.