Densely integrated interface circuits for structural health monitoring
Abstract/Contents
- Abstract
- The field of aerospace structural health monitoring (SHM) has envisioned embedding piezoelectric sensors inside the airframe to actuate and sense ultrasounds for the detection of defects. This will bring tremendous safety and economic benefits. One technical improvement that will make the whole system embeddable and reliable is integrating the sensor interface electronics in a silicon chip to replace the current bulky solution. This can potentially enable mass deployment of SHM. The key challenge for implementing such an IC lies in the piezo actuation, due to the simultaneous requirements for high drive voltage (several tens of volts), relatively high excitation frequencies (several hundred kilohertz) and low-distortion continuous excitation waveform. This is beyond what existing IC products can achieve. This research investigates a piezo driving scheme in which the required wave-form is generated by a pulse width modulated (PWM) class-D power amplifier (PA) with off-chip filtering. The pulse transition times are pre-computed through a least square optimization problem, and stored digitally to take advantage of the a priori knowledge of the SHM excitation signal. A digital calibration technique is introduced to achieve sub-nanosecond timing accuracy and -40 dB signal dis-tortion spec. To evaluate this concept, a four-channel, ±36 V, 780 kHz piezo driver chip was designed and fabricated in a 0.25 [mu] m BCD process. The IC achieves output signal distortion of -40.5 dB after calibration, improved more than 13 dB from the uncalibrated performance. An SHM system based on Flex-PCB, which combines the IC and the piezos, was designed and built. The IC and the system were demonstrated using an SHM test bed.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2014 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Guo, Yang |
|---|---|
| Associated with | Stanford University, Department of Electrical Engineering. |
| Primary advisor | Murmann, Boris |
| Thesis advisor | Murmann, Boris |
| Thesis advisor | Chang, Fu-Kuo |
| Thesis advisor | Khuri-Yakub, Butrus T, 1948- |
| Advisor | Chang, Fu-Kuo |
| Advisor | Khuri-Yakub, Butrus T, 1948- |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Yang Guo. |
|---|---|
| Note | Submitted to the Department of Electrical Engineering. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2014. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2014 by Yang Guo
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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