The drive of analytic MEMS gyroscope and express feeling and working principle
[introduction] traditional gyroscope basically is to use principle of angular momentum conservation, accordingly it basically is the object of a ceaseless roll, its runner shaft is pointed to do not follow bear the weight of the whirl of its bracket and change.
Traditional gyroscope basically is to use principle of angular momentum conservation, accordingly it basically is the object of a ceaseless roll, its runner shaft is pointed to do not follow bear the weight of the whirl of its bracket and change.
But MEMS gyroscope (Gyroscope) working principle is not such, because should use small mechanical technology,the structure that gives to be able to turn is being machined on silicon chip underlay can not be an easy thing. MEMS gyroscope uses Keliaolili body is in —— gig what what when having radial campaign, get is tangential force. It is to derive below Keliaolili’s method. The reader that has mechanical knowledge should be not fathomless.
Dynamic coordinate is being established in the space is (graph one) . With the following equation computational acceleration can get 3, come from radial to quicken respectively, Keliaoli acceleration and afferent acceleration.
Graph one, dynamic coordinate is
If the object does not have radial motion on disc, keliaolili won’t arise. Accordingly, on the design of MEMS gyroscope, this object by drive, keep be being done back and forth radial moves or concussion, keep answering change in horizontal all along namely with this corresponding Keliaolili, make the object is in likely transverse make tiny quake, phasic as it happens and driving force differ 90 degrees. (graph 2) the portable electric capacity that MEMS gyroscope has two way normally board. Radial capacitance board add concussion voltage to force an object to make radial motion (in resembling accelerometer a bit check mode oneself) , transverse capacitance board the electric capacity that because motion brings transverse Keliaoli,gauges changes (measure acceleration just like accelerometer) . Because of Keliaolili direct ratio at angular velocity, can calculate by the change of capacitance so an angular velocity.
Graph 2, the drive of MEMS gyroscope and pass feeling
Graph 3 it is gyroscope of Z axis MEMS. It was used close output of loop, number and sensor chip follow ASIC chip to be made the same score apart put those who connect a line to enclose a method.
Graph 3, graph of principle of BOSCH SMG 070