Microelectromechanical Systems(MEMS) Gyroscope
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The document discusses MEMS gyroscopes, which are devices used to measure orientation and rotation based on the principles of gyroscopic motion and Coriolis effect. It outlines their fundamental concepts, working principles, fabrication technologies, and various applications in fields such as smartphones and automotive systems. The conclusion emphasizes the engineering effort involved in MEMS design and the potential for future advancements in sensitivity and robustness, highlighting their versatility and growing relevance.
Microelectromechanical Systems(MEMS) Gyroscope
- 1. MEMS GYROSCOPE BY PRATIK K. NABRIYA (UNIV.EXAM.No.T120020891) GUIDED BY PROF.S.S.PRABHUNE SAVITRIBAI PHULE PUNE UNIVERSITY MAHARASHTRA INSTITUTE OF TECHNOLOGY , PUNE 1Department of Mechanical Engineering
- 2. Table of Contents • Gyroscope • Gyroscopic Principle • Introduction to MEMS • MEMS Gyroscope • Fundamental Concept and Design Principle • Working Principle • Fabrication Technologies • Applications & Future Scope • Conclusion • References 2Department of Mechanical Engineering
- 3. What is a Gyroscope ? • Gyroscope is a device for measuring and maintaining orientation based on principle of angular momentum. • Mechanically, Gyroscope is spinning wheel/disc mounted on axle and axle is free to assume any direction. 3Department of Mechanical Engineering Fig.1. A MECHANICAL GYROSCOPE
- 4. Gyroscopic Principle : Department of Mechanical Engineering 4 Fig.2. GYROSCOPIC PRINCIPLE
- 5. • Spinning object that is tilted perpendicularly to the direction of the spin will have a precession. • The precession keeps the device oriented in a vertical direction so the angle relative to the reference surface can be measured. Department of Mechanical Engineering 5 Gyroscopic Principle :
- 6. Applications of conventional mechanical gyroscopes : • Aircrafts • Ships • Missiles • Satellites and spacecrafts Department of Mechanical Engineering 6 Fig.3. GYROCOMPASS USED IN AIRCRAFTS
- 7. Introduction to MEMS Technology • Micro-electromechanical systems (MEMS) technology is a process technology used to create tiny integrated devices or systems that combine mechanical and electrical components. • It combines conventional semiconductor electronics with beams, gears, accelerometers, gyroscopes, diaphragms levers, switches, sensors, and heat controllers; all of them microscopic in size. Department of Mechanical Engineering 7 Mechanical Electrical MEMS
- 8. MEMS Gyroscopes • Micro-Electro-mechanical Systems (MEMS) gyroscope is a sensor that measures angle or rate of rotation. • In recent years MEMS gyroscopes have gained popularity for use as rotation rate sensors in commercial products like , - Mobile Handsets - Automobile - Game consoles Department of Mechanical Engineering 8
- 9. Why MEMS ? Department of Mechanical Engineering 9 Small size Low Cost Low Power consumption
- 10. Fundamental Concept : Coriolis effect • Coriolis’ Acceleration : It is an apparent acceleration that arises in rotating frame of reference. It is proportional to the rate of rotation Ω. acor = 2(V x Ω) • Coriolis Force : Thus the Coriolis force acting on particle of mass ‘ m ’ is given by : Department of Mechanical Engineering 10
- 11. Department of Mechanical Engineering 11 Fig .4. ILLUSTRATION OF CORIOLIS EFFECT
- 12. Fundamental Design Principle : Drapers tuning fork Department of Mechanical Engineering 12 Fig.5. DRAPERS TUNING FORK APPARATUS
- 13. Department of Mechanical Engineering 13 Fig.6. The first working prototype of Drapers Lab comb drive tuning fork single axis gyroscope (1993)
- 14. Department of Mechanical Engineering 14
- 15. Working Principle : Department of Mechanical Engineering 15 Fig.7. LUMPED STRUCTURAL MODEL OF MEMS VIBRATORY GYROSCOPE
- 16. Working Principle : • Drive mode operation : • Sense mode operation : • Combined system of motion : Department of Mechanical Engineering 16
- 17. Department of Mechanical Engineering 17 Fig.8. AMPLITUDE V/S FREQUENCY GRAPH
- 18. Department of Mechanical Engineering 18 Fig.9. Amplitude Error % V/s Delta F
- 19. Fabrication Technologies There are fundamentally two alternative technologies available for the fabrication of micromechanical devices: Department of Mechanical Engineering 19 Bulk Micromachining Surface Micromachining
- 20. Bulk Micromachining Department of Mechanical Engineering 20 Fig.10. TYPICAL STEPS IN BULK MCROMACHINING
- 21. Surface Micromachining Department of Mechanical Engineering 21 Fig.11. TYPICAL STEPS INVOLVED IN SURFACE MICROMACHINING
- 22. Applications & Future Scope Department of Mechanical Engineering 22 SMARTPHONES Precise motion sensing such as user acceleration, angular velocity and rotation rate. • Gesture recognition • Optical Image stabilization. • Navigation • Interactive gaming.
- 23. Department of Mechanical Engineering 23 Fig.12.LBS apps on smart phones. Wikitude (left) displays wikipedia information of the landmark in the camera view. Yelp (right) shows the distance to nearby restaurants and their on-line rating and reviews.
- 24. • Fig.13. INTERACTIVE GAMING APPLICATION Department of Mechanical Engineering 24
- 25. Automotive Application • Yaw rate sensor • Electronic stability control (ESC ) braking system. • Roll rate sensors • Airbags safety system. • Vehicle security System. Department of Mechanical Engineering 25
- 26. Department of Mechanical Engineering 26 Fig.14. Illustration of the angular rate and acceleration detection axes in automotive applications.
- 27. Department of Mechanical Engineering 27 Fig.15. SegwayTM and SolowheelTM personal human transporter.
- 28. Some Other Similar Applications Guided and Automatic Missile Systems. Smart Wheelchair. Optical Image Stabilization. Smart Bullet & Ammunition Satellites stabilization. Department of Mechanical Engineering 28
- 29. Conclusion • A great deal of engineering goes into design, manufacturing and implementation of MEMS devices such as gyroscopes. • MEMS truly bridge gap between electrical and mechanical engineering. • This presentation was an attempt to understand the fundamental concepts, working principle and applications of MEMS gyroscopes. • MEMS fabrication technologies have also been dealt with. • There is still a lot of room for improvement in current techniques, especially in reducing drift and increasing sensitivity. • Future work is to improve mechanical angular rate sensitivity as well as robustness by 2-DOF drive mode instead of current 1-DOF. • It is believed that there will be countless other applications discovered for MEMS gyroscopes in the coming years due to their versatility and size. Department of Mechanical Engineering 29
- 30. References : • Yeonhwa Jeona, Heejun Kwona, Hyeon Cheol Kima, Sung Wook “Design and development of a 3-axis micro gyroscope with vibratory ring springs”, EUROSENSORS 2014, the XXVIII edition. • Hai Xua*, Jang Ching Chuab, Michael Burtonb, Kefei Zhanga, Franz Konstantin Fussb,Aleksandar Subicb “Development of low cost on-board velocity and position measurement system for wheelchair” 8th Conference of the International Sports Engineering Association (ISEA) • Cenk Acar, Adam R. Schofield, Alexander A. Trusov, Lynn E. Costlow,, and Andrei M. Shkel, “Environmentally Robust MEMS Vibratory Gyroscopes for Automotive Applications” IEEE SENSORS JOURNAL, VOL. 9, NO. 12, DECEMBER 2009 • Zhou Xiaoyao, Zhang Zhiyong, Fan Dapeng “Improved Angular Velocity Estimation Using MEMS Sensors with Applications in Miniature Inertially Stabilized Platforms” Chinese Journal of Aeronautics 24 (2011) • Venkata Ramesh Mamillaa, Kommuri.Sai Chakradhar “Micro Machining For Micro Electro Mechanical Systems(MEMS)” 3rd International Conference on Materials Processing and Characterisation Department of Mechanical Engineering 30
- 31. Department of Mechanical Engineering 31 THANK YOU