| 摘要 |
An acoustic pin detecting and locating device is disclosed, comprising a linear array of transducers mounted on each kickback wall. A microprocessor sequentially energizes each transducer with a short burst of high frequency pulses; the reflections from standing pins to the transmitting transducer (direct data) and the next adjacent transducer (cross data) are gated into separate a/d converters. The converters are sampled periodically to divide the signal return to each transducer into a plurality of range cells. The direct data and cross data returns to each transducer array form two data fields. Analysis of these fields provides the information needed for detection of the location of each standing pin. The system electronics include a specially designed transducer selection system including a shift register for selecting only one transducer at a time to transmit acoustic energy, and simultaneously enable one or more gates connected to the transmitting transducer and the next adjacent transducer to transfer analog signal representations of the echo signals to the a/d converters. Each a/d converter incorporates a threshold comparator, specially designed so that the threshold is logarithmically increased each time the magnitude of the echo signal return exceeds the threshold, up to a defined maximum. Each time the converter output count is sampled, the threshold is reset to its base level.
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