Variable geometry capacitive probes for multipurpose sensing

Informa UK Limited - Tập 1 - Trang 111-132 - 1989
Mark Gimple1, B. A. Auld2
1Ford Aerospace Corporation, Palo Alto, USA
2Edward L. Ginzton Laboratory, Stanford University, Stanford, USA

Tóm tắt

A capacitive array for robotic proximity and feature sensing has been designed, modeled, and tested. The basic probe consists of alternating metallic strip electrodes. One set of strips makes up the drive plate. The other set consists of tiny receivers. Both sum and differential modes of operations are used to allow one to detect proximity and features, respectively. Modeling has encompassed calculation of admittance changes (ΔY) due to the introduction of materials with simple geometric configurations. The theory is developed in detail using the Lorentz reciprocity theorem. The relationship between the spatial frequency of the probe electrodes and the interrogation field penetration is also discussed. Testing has involved scanning a two-port configured probe system over a test piece with known features and flaws. Four capabilities of the probe have been examined: distance ranging, edge detection, field optimization (changing the electric field pattern of the probe to enhance output signal), and complex pattern recognition (filtering). Both dielectric and metal objects have been investigated.

Tài liệu tham khảo

J.A. Allocca and A. Stuart.Transducers: Theory and Applications, p. 89. Reston Publishing, Reston (1984) J.B. Angell, S.C. Terry and P.W. Barth.Scientific American 248:44 (1983) R.A. Boie. InProceedings of 1984 International Conference on Robotics, p. 370. Atlanta, Georgia (1984) W.R. Iversen.Electronics 56:52 (1983) K.J. Binns and P.J. Lawrenson.Analysis and Computation of Electric Field Problems, 2nd edition, p. 190. Pergamon, Oxford (1973) B.A. Auld and M. Riaziat,J. Appl. Phys. 54:3509 (1983) D.R. Day, inReview of Progress in Quantitative Nondestructive Evaluation 5B, edited by D.O. Thompson and D.E. Chimenti, p. 1037, Plenum. New York (1986) D.E. Kranbuehl, S.E. Delos, E.C. Yi, and J.T. Mayer. InReview of Progress in Quantitative Nondestructive Evaluation 5B, edited by D.O. Thomspon and D.E. Chimenti, p. 1029. Plenum, New York (1986) G.D. Vendelin.Design of Amplifiers and Oscillators by the S-Parameter Method, p. 14. Wiley, New York (1982) B.A. Auld, F.G. Muennemann, and M. Riaziat. InResearch Techniques in Nondestructive Testing, 7, edited by R.S. Sharpe, p. 37. Academic Press, London (1984) S. Ramo, J.R. Whinnery, and T. Van Duzer.Fields and Waves in Communication Electronics, 2nd edition, p. 283. Wiley, New York (1984)