IN THE NAME OF GOD Instrumentation Term Project Supervised By: Dr. Hamid D. Taghirad
Magnetic position sensor Ehsan Peymani Golnaz Habibi
Magnetic Sensor
Feature of Magnetic Sensors Advantage - Contact less - Unaffected by Contamination Disadvantage - affected by other magnetic field
Position sensing ( all types ) Capacitive Eddy current Optical Inductive Resistive Sonar Laser Magnetic
All Types of Magnetic Position Sensor Hall effect sensor Magnetostrictive Magnetoresistive Base on Seismic theory Reed switch Synchro & Resolver Inductosyn Magnesyn Magnetic encoder LVDT & RVDT
Special application Compassing GPS navigation Vehicle detection
Special application Compassing
Special application Compassing
Special application Compassing
Special application GPS navigation
Special application GPS navigation
Special application Vehicle detection
Special application Vehicle detection
Special application Vehicle direction
Smart position sensor
Smart position sensor Specifications : Magnetostrictive LDT Small & Inexpensive Linearity+/- 0.05% of Stroke Accuracy+/- 0.1% of Stroke Repeatability+/- 0.01% of full stroke Operating Temperature-20 to 70 C Programmable
Hall Effect Sensor Hall effect : Dr. Edvin Hall, 1879 Johns Hopkins University Hall sensor : Joe Maupin & Evertt Vorthmann, 1965
Hall effect General features True solid state Long life High speed operation - over 100 khz possible Operates with stationary input (zero speed) No moving parts Logic compatible input and output Broad temperature range (-40 to +150 C) Highly repeatable operation
Hall effect Theory
Hall effect Theory V H = K H BI t
Hall effect Theory
Hall effect Conditional Circuit S = 7 µ V V G!!! Silicon exhibits the piezoresistance effect
Hall effect Conditional Circuit
Hall effect Digital Hall sensors
Hall effect Analog Hall sensors
Hall effect Magnetic system Unipolar head-on mode Unipolar slide-by mode Bipolar slide-by mode Bipolar slide-by mode (ring magnet) Jump to Application
Hall effect Magnetic system Unipolar head-on mode Nonlinear Accuracy medium
Hall effect Magnetic system Unipolar slide-by mode Nonlinear Accuracy low Symmetric
Hall effect Magnetic system Bipolar slide-by mode Accuracy medium Dissymmetry
Hall effect Magnetic system
Hall effect Magnetic system Bipolar slide-by mode (ring magnet)
Hall effect Magnetic system comparison chart
Hall effect Application Vane operated position sensors
Hall effect Application Vane operated position sensors
Hall effect Application Other in position Sequence sensor Proximity sensor Office machine sensors Multiple position sensor Anti-skid sensor Piston detection sensor
Hall effect Application Sequence sensor Back
Hall effect Application Proximity sensor Back
Hall effect Application Office machine sensors Back
Hall effect Application Multiple position sensor Back
Hall effect Application Anti-skid sensor Back
Hall effect Application Piston detection sensor Back
Magnetostrictive sensors Invent at 1970 MTS Temposonic technology
Theory of Magnetostrictive sensors Manetostrictive effect Villari effect Wiedemann effect
Theory of Magnetostrictive sensors Manetostrictive effect
Theory of Magnetostrictive sensors Villari effect Reverse of Magnetoestrictive applying stress to a magnetostrictive material changes its magnetic properties
Theory of Magnetostrictive sensors Wiedemann effect
Theory of Magnetostrictive sensors The operation
Theory of Magnetostrictive sensors The operation
Magnetostriction sensors Features Non contact Absolute 10 mm ~ 20 m Nonlinearity < 0.02%
Magnetostriction sensors Comparison
Magnetostriction sensors Application 1. Automated (Robotic) ManualTrans ission 2. Automotive Suspensions 3. Automotive Steering 4. Medical Hospital and Home Care Bed 5. Medical Infusion Pump 6. Medical Dental Chairs 7. Tractor Steering 8. Commercial Appliance Damping 9. Automotive Tank Levels 10. Construction Equipment
Magnetostriction sensors Application Automated (Robotic) ManualTrans ission Back
Magnetostriction sensors Application - Automotive Suspensions Back
Magnetostriction sensors Application - Automotive Steering Back
Magnetostriction sensors Application - Medical Hospital and Home Care Bed Back
Magnetostriction sensors Application - Medical Infusion Pump Back
Magnetostriction sensors Application - Medical Dental Chairs Back
Magnetostriction sensors Application - Tractor Steering Back
Magnetostriction sensors Application - Commercial Appliance Damping Back
Magnetostriction sensors Application - Construction Equipment Back
Magnetostriction sensors Application - Automotive Tank Levels Back
Magnetoresistive sensors Invent at 1856 William Thompson Lord Kelvin
Magnetoresistive sensors All types Anisotropic Magnetoresistive (AMR) Giant Magnetoresistive (GMR) Colossal Magnetoresistance (CMR)
Magnetoresistive sensors Theory of AMR
Magnetoresistive sensors Theory of AMR 2 cos θ Barber Pole Bias
Magnetoresistive sensors Theory of AMR
Magnetoresistive sensors Operation of AMR
Magnetoresistive sensors Operation of AMR (HMC1501)
Magnetoresistive sensors Operation of AMR (HMC1501)
Magnetoresistive sensors Operation of AMR (HMC1501)
Magnetoresistive sensors Operation of AMR (HMC1512)
Magnetoresistive sensors Operation of AMR (HMC1512)
Magnetoresistive sensors Operation of AMR (HMC1512)
Magnetoresistive sensors Operation of AMR (HMC1512)
Magnetoresistive sensors Typical application Cylinder position sensing in pneumatic cylinders Elevator sensor Lid sensor for laptop computers Position sensor for materials handling equipment (lift trucks) Blood analyzer Magnetic encoders
Magnetoresistive sensors Comparision of Hall effect & MR technologies
Magnetoresistive sensors Giant Magnetoresistive (GMR) Observe at 1988 Magnetoresistivity > 70%
Magnetoresistive sensors Giant Magnetoresistive (GMR) - Theory
Magnetoresistive sensors Giant Magnetoresistive (GMR) - Application Proximity Detection Displacement Sensing Rotational Reference Detection
Colossal Magnetoresistive (CMR) Observe at 1988 Magnetoresistivity > 1000% ~ 10000000%
Magnetoresistive sensors Comparison
Reed switch
Reed switch Structure
Reed switch Advantages Long life Small size Very sensitive to magnetic fields Has no leakage current or voltage drop Very inexpensive Highly repeatable operation High immunity to dirt and contamination Zero power consumption
Reed switch Disadvantages It is electronically noisy Slow response time Large amount of hysteresis
Synchro & Resolver A device called Selsyn was developed at 1925
Synchro Theory Synchro is variable rotary transformer.
Synchro Classification Transmitter Control Torque
Synchro Classification Receiver Control Torque
Synchro Classification Differential Transmitter Control Torque
Synchro Classification Control Torque
Synchro Advantages The controlling unit can be along distance from the controlled unit. Low consumption. Eliminates the necessity of mechanical linkage. Continues accurate and visual information. Good reliability and minimum maintenances. Small and light. Very fast.
Resolver
Resolver Theory
Signal Conditioning Resolver-To-Digital Converter(RTD /RDC) Basic Undersampling Oversampling
RTD Basic.
RTD Undersampling
RTD Undersampling
RTD Oversampling
Oversampling TMS320F240
Resolver Advantages Accurate Absolute Position Sensor Small size Well-suited to severe industrial environments Not require ohmic contact. High reliability
Synchro& Resolver Application Naval weapons Radar antennas Aerospace Robotics
Inductosyns
Inductosyns types Linear inductosyn Rotary inductosyn
Linear inductosyns
inductosyns Specification Use RTD for signal conditioning Linear resolution is 5microinch. angular resolution is less than 0.9 arc seconds relatively expensive very high accurate very reliable
inductosyns Advantages & Disadvantages Accurate Small size Well-suited to severe industrial environments Not require ohmic contact High reliability but relatively expensive
Magnesyn
Magnesyn Structure
Magnetic encoder All types
LVDT & RVDT End of World War II
Linear Variable Differential Transformer(LVDT)
PRECISION ABSOLUTE VALUE CIRCUIT (FULL-WAVE RECTIFIER)
LVDT & RVDT Comparison LVDT Measurement ranges are ±100µm to ±25cm Sensitivity is 2.4mv per volt per degree of rotation Input voltages are from 1V to 24V RMS, with frequencies 50Hz- 0kHz RVDT Typical RVDTs are linear over a range of about ±40º Sensitivity is 2 to 3mV per volt per degree of rotation Input voltages in the range of 3V RMS at frequencies between 400Hz and 20kHz.
LVDT Advantages Infinite Resolution High accuracy and sensitivity Excellent linearity ( 0.5%) A wide variety of measurement ranges
Application Modern Machine-tool Robotics Avionics & aircraft Process control industry Torpedo, and weapons systems.
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