- 學位論文
以壓電式微加工超音波感測器實現之空間距離感測系統
Airborne Piezoelectric Micromachined Ultrasound Sensor for Range Detection System
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摘要
在自動化時代的進步下，大眾對於實現自動駕駛的夢想更加渴望，因此先進駕駛輔助系統(ADAS)的發展成為當今熱門的議題之一，加上隨著超音波感測技術的進步，若能開發出體積小、製程簡便、低能耗且性能優越的超音波距離感測器，對於先進駕駛輔助系統的應用有很大的發展性。 本研究是以開發壓電式微機電超音波感測器為目標，實現超音波感測技術之空間距離感測應用。使用不鏽鋼基板搭配微機電製程和氣膠沉積法，製作出壓電感測器元件，並且與 PCB 板、電路板整合，最終成功提升靈敏度，並且透過飛時測距系統來達到空間距離感測之目的搭配微機電製程。元件共振頻位於63.35 kHz，平均靈敏度為-34.85 dBV/Pa，在聲壓位準為94 dB、頻率為共振頻時，元件之訊噪比為26.97 dB，指向性型態為接近全指向性。 在距離感測的量測成果中，當驅動高音喇叭之電壓固定為12 Vpp時，可偵測到之最遠距離為1.25 m，即超音波傳遞之來回距離為2.5 m，且量測結果和實際距離之相關係數為0.99995，而相對誤差為1.4%，約為18 mm。
並列摘要
With the advancements in automation, the general public has a growing desire to realize the dream of autonomous driving. As a result, the development of Advanced Driver Assistance Systems (ADAS) has become a hot topic in today's world. Furthermore, with the progress in ultrasonic sensing technology, there is great potential for the development of small-sized, easily manufacturable, low-power consumption, and high-performance ultrasonic distance sensors, which can significantly enhance the applications of ADAS. In this study, we present a piezoelectric micromachined ultrasound sensor for range detection. By modifying the thickness of stainless-steel substrate and fabricated by aerosol deposition and MEMS fabrication techniques, the sensor is fabricated and integrated with PCB board and circuit. The resonant frequency of the sensor component is 63.35 kHz, with an average sensitivity of -34.85 dBV/Pa. Measured at resonant frequency and sound pressure level of 94 dB, the signal-to-noise ratio of the component is 26.97 dB, and the directional pattern is close to omnidirectional. The experimental results of range detection reveal, when driving the speaker with a fixed voltage of 12 Vpp, the maximum detectable distance is 1.25 m, corresponding to a roundtrip distance of ultrasound propagation of 2.5 m. The measurement results exhibit a correlation coefficient of 0.99995 and a relative error of 1.4%, approximately 18 mm. The experimental results of range detection reveal that the maximum roundtrip range and range error about 2.5 m±36 mm by applied tweeter 12 Vpp voltage.
參考文獻
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