MechatronicsIntel Mach Engr
MechatronicsIntel Mach Engr ME 4370
Popular in Course
Popular in Mechanical Engineering
This 9 page Class Notes was uploaded by Terrence Terry II on Wednesday October 21, 2015. The Class Notes belongs to ME 4370 at Tennessee Tech University taught by Stephen Canfield in Fall. Since its upload, it has received 36 views. For similar materials see /class/225733/me-4370-tennessee-tech-university in Mechanical Engineering at Tennessee Tech University.
Reviews for MechatronicsIntel Mach Engr
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 10/21/15
Overview of Sensors or red orproeessed n eonsrsts oftwo pans Transducer Interface Signal conditioning unit Transducer Swgna Condmonrng Umt Arnpw mten condmon 5wgna rnto a meamngfm and easHy mterfaced source Note Researen m deve opmg new sensors rs enormous Tne doHaramount spent on new sensors eaen year rs very arge ans dnves many e ds suen as M e e omneesnew sensors Examples of Sensors Asens ens stem Tne Mars rovers mt Wm 39 mqu m m mm A u 39 Imum39m Wm swam m n t r m l ummn um mr uu J L yur m Mum um vm x Inquot m Uu mun mm damnrcan m m R Iv Considerations for Sensor Performance 1 Range or Span 2 Error Accuracy Resomuon 3 Hysteresrs 4 Nonhneamy 5 Repeaubmty 6 Stabmtydm 7 Banomom speed 8 Cost 9 Rehabmty 10 Ease of apphcauon Catagorizing Commercial Sensors We could categorize sensors in several fashions for eX based on theory of operation or on type ofapplication Commercial Navigation and Control Sensors ype sensors array Catagorize Based on Theory oprplication 1 Contact mechanical a b can be used as proximity limit switches etc 0 comes in many forms SPST O DO OVO DPDT o o o SPDT NO Pushbutton SPST SPDT DPDT momentary toggle etc d cheap reliable versatile e switch bounce f Another problem is low switching frequency and relatively short life 2 Mechanical movement ofan input a Vary voltage Potentiometer Available in many forms cheap absolute measurement low to medium accuracy b Vary inductance LVDT RVDT c Vary capacitance 3 Time of Flight Sensors sensors used to measure distance a Acousticbased Examples include Polaroid Devantech F LJIR3939E39 SEED PJ JIGIHE E CITI EITLE Hanamime d t2vTM Ultrasonics for NDE b EM waves 1 Radar radio waves adds Doppler shift to measure velocity 2 Lidar IR waves 3 GPS Sends a signal encoded with time use multiple to triangulate Calculate time for an acoustic wave to travel 2 m in air EM wave Triangulation Process of determining absolute position based on multiple measurements from known locations 1 1D 2 2D 3 3D 6 Pose Why 56 typical in GPS Other means to navigate Active beacon Landmarks 4 Optical Sensors a light sensitive devices 1 photodiodes 2 phototransisters Phototransistor TranSiStor C C B B For Saturation W VBE 07V and IBmin Id E E Can be sensitive to various wavelengths Used to measure proximity beambreak optoisolators remote controllers encoders discussed later 3 Photoresistor varies resistance wrt light 4 PSD position sensitive device Example Sharpe GP12 The PSD returns the position on the cell the light is received SHARP GPEDlZ IR FLAME ER 5 coo 5 Current sensing Hall effect sensors A current owing through a magnetic eld is de ected examples fuel tanks proximity Transformer Resolver type ofencoder see below 6 Pyroelectric sensors PIR One that senses IR radiation 7 Resistance change due to strain Strain gauges Aproportional to strain 8 Piezoelectric sensors materials Generate a voltage when strained 1 form used in tactile sensors eg a PVDF lm piezoelectric polyvinylidene uoride Materials for piezo electrics Lead Zirconate PZT Lead titante Lead metaniobate Barium titanate these are all ferro electric ceramics 9 Thermisters Materials metal oxides semiconductors whose resistance changes with temperature typically nonlinear change Rugged small fast response large output 10 Thermocouples Two dissimilair metals combined to form a junction A temperature differential bn two junctions creates a voltage J type lroncontantan 11 Acceleraometers Use a mass for inertia and strain gauge or PZT for sensing element Gyroscope Uses angular momentum and Euler s equation Or with three linear mass accelerometers Or with a RLG A few common sensors Encoders Used to measure rotational rate very common basic component in servo motors 1 Optical incremental encoder Uses an emitterdetector phototransistor pair a banded disk Resolution is a function ofthe disk Typical disks are 100 ppr or 500 ppr This output tells you the degree of rotation but not direction That requires quadrature the use of 2 detectors one offset from the other These would give the following output W W A D flip op could be used to give direction The quadrature output can be used to increase resolution by a factor of four One combination HP 2020 IC will perform quadrature counting and output a 16bit count when queried 2 Absolute optical encoder Unique coding signal for each location
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'