Tuesday, February 10, 2009

3 DOF Gyroscope

Gyroscopes have become of great practical interest as they are widely used in control and guidance systems for air, sea and space vehicles. Some examples include air plane automatic pilot, rocket vehicle launch guidance systems, space vehicle attitude control and submarine inertial autonavigator systems. All of these applications make use of the special dynamic properties offered by gyroscopes. As the industries involved in the above mentioned applications are always growing, the demand for availability of up to standard research tools also rises to ensure desired studies can be carried.

Quanser is soon releasing a new such product called the 3 DOF Gyroscope, depicted on the left. The device consists of a rotating disk mounted inside an inner gimbal which is in turn mounted inside a second outer gimbal. This whole structure is supported by a rectangular frame that is free to rotate about its vertical axis of symmetry. This scheme results in three degrees of freedom for the gyroscope disk. The structure is masterfully engineered to provide minimal friction on rotation axes. This makes the 3 DOF Gyroscope a great choice for research in spatial applications of gyroscopes as the zero friction of space is almost nearly achieved by the device! Each axis as well as the disk itself is actuated using a separate motor while digital position measurement on each of these axes is done via high resolution encoders. While both gimbals and the outer frame are free to rotate about their rotation axes, the frame and outer gimbal are designed such that they can be also be fixed on desire. Therefore a whole variety of experiments can be performed.

The 3 DOF Gyroscope also comes with an extensive curriculum that uses MATLAB and Quanser's QuaRC software to cover a variety of experimental tasks using the gyroscope plant such as stability analysis, root locus design, non-minimum phase effects, LQR state-feedback control and friction compensation schemes. In the video below, the plant is simulated using the Virtual Reality toolbox and QuaRC to perform position control on the gyroscope angle about the vertical axis. The yellow plot shows the reference applied in degrees while the purple plot is showing the output. Notice that as a direct result of the gyroscopic effect, the horizontal axis is actuated to control the angle about the vertical axis. That's the magic of gyroscopes!

video

(Note: 3 DOF Gyroscope is scheduled for release in March 2009)

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