Linearization of Non-Linear Pressure Sensor for Autonomous Underwater Vehicle ELG 4135 Electronics III Dr. Riadh Habash Nov. 28, 2006 Presented By: Dominic Besner, Martin Kmita, Mélanie Potvin

System Overview Pressure Sensor Compass D.V.L. Sonar SBC Actuators (Motors)

Focus of Project Pressure Sensor Pressure Sensor Pressure Range: 0 – 25 PSI Input: 4.75 – 5.25 V DC Output: 0.5 – 4.5 V DC

Objective Expected Linear Behavior: Expected Linear Behavior: P= P o + ρgD Actual Non-Linear Behavior : Actual Non-Linear Behavior : V = D D +0.62

Possible Solutions Table Look-Up Table Look-Up –Pros : Speed of the data analysis –Cons : Not accurate Frequency Domain Linearization Frequency Domain Linearization –Pros : Only need few inexpensive components –Cons : Filters are not ideal Mathematical Models Mathematical Models –Pros : Accuracy –Cons : Need Mathematical Library

Pressure Sensor Diagram

Chosen Implementation

Chosen Equation Sensor Equation: Sensor Equation: V = αD 2 +βD+C 0 α = , β = , C 0 = 0.62 Desired Equation: Desired Equation: V’ = γD

Chosen Equation Linearization Equation: Linearization Equation: V = AV’ 2 + BV’ + C 0 V’ = 1/A ( (V-C 0 )/V’ - B) A = α / γ 2 A = α / γ 2 B = β / γ γ = , A = , B =

Implementation Circuit

Offset Compensator

Divider

Adder

Implemented Circuit

Simulation Results

Results

Conclusion Modeled the non-linear characteristics of a pressure sensor using a second order equation Modeled the non-linear characteristics of a pressure sensor using a second order equation Designed a mathematical model to linearize the output voltage Designed a mathematical model to linearize the output voltage Implemented a linearization circuit using simple and inexpensive components based on the mathematical model Implemented a linearization circuit using simple and inexpensive components based on the mathematical model

References Christopher D. Williams, “AUV Systems at the NRC-IOT: An Update”, IEEE Underwater Technology, UT ' International Symposium on, Christopher D. Williams, “AUV Systems at the NRC-IOT: An Update”, IEEE Underwater Technology, UT ' International Symposium on, Nabil I. Khachab, Mohammed Ismail. “Linearization Techniques for nth-Order Sensor Models in MOS VLSI Technology”. IEEE Transaction on Circuits and Systems, Vol. 38, No. 12, Decembre Nabil I. Khachab, Mohammed Ismail. “Linearization Techniques for nth-Order Sensor Models in MOS VLSI Technology”. IEEE Transaction on Circuits and Systems, Vol. 38, No. 12, Decembre J.M. Dias Pereiral, O. Postolache, P. Silva Girao, “Adaptive Self-Calibration Algorithm for Smart Sensors Linearization”. IMTC 2005 Instrumentation and Measurement Technology Conference, Ottawa, Canada, May 17 to 19, J.M. Dias Pereiral, O. Postolache, P. Silva Girao, “Adaptive Self-Calibration Algorithm for Smart Sensors Linearization”. IMTC 2005 Instrumentation and Measurement Technology Conference, Ottawa, Canada, May 17 to 19, D. Besner, J. Cheong, E. Ho, M. Kmita, S. Nguyen, “Development of an Autonomous Underwater Vehicle with Custom Passive Sonar”. University of Ottawa, December D. Besner, J. Cheong, E. Ho, M. Kmita, S. Nguyen, “Development of an Autonomous Underwater Vehicle with Custom Passive Sonar”. University of Ottawa, December Benson Harris, “University Physics”. John Wiley & Son Inc., revised edition, Quebec, Canada, 1996, Chapter 14, p: Benson Harris, “University Physics”. John Wiley & Son Inc., revised edition, Quebec, Canada, 1996, Chapter 14, p:

References (con’t) MSI sensor. “MSP 600 Datasheet”. May 25th 2004, Revision C. MSI sensor. “MSP 600 Datasheet”. May 25th 2004, Revision C. TSI Incorporated. “Thermal Anemometry System” Visited on November 5th, TSI Incorporated. “Thermal Anemometry System” Visited on November 5th, Grayson King, Toru Fukushima. “RTD Interfacing and Linearization Using ADuC8xx MicroConverter”. Application Note for Analog Devices, Rev. 0, Grayson King, Toru Fukushima. “RTD Interfacing and Linearization Using ADuC8xx MicroConverter”. Application Note for Analog Devices, Rev. 0, Kwok-Keung M. Cheng, Chi-Shuen Leung. “A Novel Generalized Low-Frequency Signal- Injection Method for Multistage Amplifier Linearization”. IEEE Transaction on Microwave Theory and Techniques, Vol 51, No.2, February Kwok-Keung M. Cheng, Chi-Shuen Leung. “A Novel Generalized Low-Frequency Signal- Injection Method for Multistage Amplifier Linearization”. IEEE Transaction on Microwave Theory and Techniques, Vol 51, No.2, February 2003.

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