Business Technology Consulting

Successful Business with RFID, RTLS and Beyond

Sensors



























U-S Motion


U-S Position


U-S Velocity


U-S Flow Speed


The Fundamental Physical Principles of sensing include Electric Charges, Electrical, Gravitation Fields, Potentials, Resistance, Capacitance, Induction, Magnetism, Piezoelectric or Thermoelectric Effects and Light and so on. Often sensors based on different physical principles perform the same function. Utilization of a few of them considerably reduces incorrect detections and increases sensors redundancy and detectability. Controllable wireless sensors can form a network thus enabling automation of business and industrial processes in military, industrial and commercial applications. Wireless sensor network is a group of devices performing sensing, data processing and wireless ad-hoc data communications. This powerful synergy enables innovative applications. A networked sensor can be a radar station, pollution monitor, video camera, mobile phone, heart rate monitor, or just a simple ID tag. The most popular communications standards in Wireless network include Wi-Fi IEEE 802.11a/b/g/n/as and ZigBee IEEE 802.15.4.


Capabilities 

Occupancy and Motion Detectors

·         Ultrasonic (Reflections and Doppler effects)

·         Capacitive

·         Optoelectronic

·         IR: sensitive to heat waves

 

Position, Displacement, and Level Sensors

·         Capacitive & Inductive

·         Eddy Current

·         Polarized Light

·         Ultrasonic

 

Velocity and Acceleration Sensors

·         Video CCTV

·         Radars

·         Capacitive, Piezoelectric

·         Gravitational

 

Flow Sensors

·         Pressure Gradient Technique

·         Thermal Transport

·         Drag Force

 

Light Detectors

·         Photodiodes

·         Phototransistor

·         Image - Face Recognition System

·         Gas Flame

 

Characteristics 

·         Accuracy

·         Drift

·         Hysteresis

·         Linearity

·         Measurement Range

·         Minimum Detectable Signal

·         Precision

·         Repeatability

·         Selectivity

·         Sensitivity 


 CHALLENGES & ISSUES 

·         Problems in Powering Wireless Sensor Nodes

·         Sensors are sources of RFI/EMI

·         Incorrect: rejection of a true existing objects; and acceptance of non-existing objects

·         Sensor cross-sensitivities associated with environmental effects

·         Ultrasonic sensors have low spatial selectivity

·         Infrared motion detectors are susceptible to heat waves

·         Fading effect of electromagnetic waves reflected from objects

·         Ultrasonic signals corruption by waves reflected from objects

·         Sensors failure because of insufficient reliability, selectivity, or noise immunity