EE 587 Presentation Gyroscope Used As Rate Sensor Instructor: Dr. Lumpp Presenter: Wei Lu
What Is A Gyroscope • Gyroscope is a device consisting of a spinning mass, typically a disk or wheel, mounted on a base so that its axis can turn freely in one or more directions and thereby maintain its orientation regardless of any movement of the base.
Historical Issue • The first modern gyroscope was developed in the first half of the 19th century by the French physicist jean B. L. Foucault, and its first notable use was in a visual demonstration of the earth's rotation.
Gyroscopic Effect • A straightforward observation: Coriolis effect • Examples: River bank Train’s wheels
Gyroscope Vs. Rate Sensor • The major difference: gyroscope can be mounted at any position of the rotational frame to sense the rate of rotation, while the conventional rate sensor needs to have an aligned shaft to be mounted exactly at the centre of the rotational frame. • Conclusion: the conventional rate sensor cannot be used in navigation systems where the centre of the rotational frame is unknown.
Merits of Gyro As Rate Sensor • Low power consumption, • High sensitivity, • Low temperature drift, • Good stability
Principle of Gyro Coriolis force -- the main physical principal to explain the vibrating gyroscope operation. In general, when in a rotating frame, there is a force on all moving objects which is given by: FCoriolis = -2 m (w x vr) Where w is angular frequency and vr is radial velocity. The direction of Coriolis force is orthogonal to the velocity vector and the rotation vector.
Principle of Gyro • The spin axis: the source of the gyroscopic effect • The primary axis: conceptually the input or driving axis • The secondary axis: output
Principle of Gyro • More details can be found at: http://www.gyro-scope.co.uk/how.htm
Some Types of Gyro Rate Sensor • Example 1: Manufacturer: NEC/TOKIN Model: CG-16D, CG-L43
NEC/TOKIN CG-16D, CG-L43 • Appearance:
NEC/TOKIN CG-16D, CG-L43 • Vibrating Element Structure
NEC/TOKIN CG-16D, CG-L43 Shape and Dimension
NEC/TOKIN MDP-A3U7 • Example 2: Manufacturer: NEC/TOKIN Model: 3D Motion Sensor MDP-A3U7
NEC/TOKIN MDP-A3U7 • Appearance:
NEC/TOKIN MDP-A3U7 • Specifications
NEC/TOKIN For more information, visit the website: www.tokin.com
MURATA GYROSTAR ENC-03JA • Example 3: Manufacturer: MURATA Model: GYROSTAR ENC-03JA
MURATA GYROSTAR ENC-03JA • Appearance:
MURATA GYROSTAR ENC-03JA • Outline: This product is offers many excellent features such as quick-response when detecting a moving object or the increased flexibility of installment because of its small and light weight design
MURATA GYROSTAR ENC-03JA • Features 1. Ultra-small and ultra-lightweight 2. Quick response 3. Low driving voltage, low current consumption 4. Reliable features achieved by a built-in-AGC circuit
MURATA GYROSTAR ENC-03JA • Applications 1. Detecting hand movement involved in video and still camera 2. Detecting vibrations in various vibration free table and isolators 3. Detecting the own movement
MURATA GYROSTAR ENC-03JA • Specification
MURATA GYROSTAR ENC-03JA • External Dimensions
MURATA GYROSTAR ENC-03JA • Terminal Descriptions
MURATA GYROSTAR ENC-03JA • Application
MURATA GYROSTAR ENC-03JA For more information, visit the website: www.murata.com
Some Applications of Gyro Sensors Gyration Wireless Products & Accessories • Ultra Mouse: the world's only in-air motion sensing mouse
Some Applications of Gyro Sensors • GyroRemote™: wireless presentation controller with motion-sensing technology
Some Applications of Gyro Sensors • Mobile Keyboard: Wireless RF Keyboard with 100-ft. range and Internet/Multimedia hot keys.
Conclusion Gyroscope is very useful in many applications. To chose the right rate gyro sensor, some features, such as power consumption, weight, dimension, etc., must be taken into consideration.