Sensors and Actuators Introduction to sensors

Transcription

1 Sensors and Actuators Introduction to sensors Sander Stuijk Department of Electrical Engineering Electronic Systems

2 2 5ES00 = 5CI30 + 5CI31 3 ECTS awarded for each CI course passed

3 3 Embedded systems an embedded system is a device used to control, monitor or assist the operation of equipment, machinery or plant. embedded" reflects the fact that the information processing system is an integral part of the device.

4 4 Embedded systems embedded systems make up a large percentage of the product cost embedded systems are the driving force behind the only silent revolution the world has ever seen

5 5 Embedded systems embedded systems are different from personal computers embedded systems are reliable consider many demands (energy, code size,...) designed for a specific application often real-time often reactive

6 6 Embedded systems an embedded system consists of an actuator a sensor an embedded processor and often a communication network actuator processor communication sensor

7 7 PRACTICAL NOTES

8 8 Prior knowledge you should be familiar with the following subjects signal processing electronics special lectures and labs are organized for students that lack this background...

9 9 Prior knowledge signal processing you should be familiar with... sinusoidal waves complex numbers, phasors and phasor addition rule spectral representation of signals, harmonic frequencies and multiplication Fourier transform AD/DA conversion: sampling, quantization and under-sampling FIR filter power and noise lectures on this topic are... mandatory for BTI, BTB, BTW, BID, BST, BW part of `digital signal processing (5HH30) lecture on Thursday (optional), instruction on Friday exam question during exam of 5CI30

10 10 Prior knowledge signal processing example question

11 11 Prior knowledge electronics you should be familiar with... passive components (R, L, C) operational amplifiers complex impedance of a circuit circuits needed for AD/DA conversion circuits needed for filtering transistors lectures on this topic are... mandatory for BTI, BTB, BTW, BID, BST, BW part of `actuation techniques (5CI31)

12 12 Prior knowledge electronics example question Z 4 V in Z 1 Z 2 i 1 V a i 2 V- i 3 V+ Z V out Figuur In Figuur 4 is een schakeling met een opamp getekend. Veronderstel dat de eigenschappen van de opamp ideaal zijn. a. Wat is de relatie tussen V+ en V-? (0.2/2.5) b. Stel de Kirchhoff stroomwet op voor punt V a. (0.2/2.5) c. Bereken de spanning V a als functie van Z 1,Z 2, Z 3 en V in met behulp van de Kirchhoff stroom wet. (0.4/2.5) d. Bereken i 2. (0.2/2.5) e. Beschrijf V out als functie van Z 1,Z 2, Z 3, V in en Z 4 (0.4/2.5)

13 13 Schedule (Quartile 1) physics (BEI, BTN, BBT) electronics (BTI, BTB, BTW, BID, BST, BW) students join instructions of 5HH30 (digital signal processing)

14 14 Schedule (Quartile 2) physics (BEI, BTN, BBT) electronics (BTI, BTB, BTW, BID, BST, BW) location to be announced later

15 15 Exam written exam of 3 hours includes question on signal processing (if applicable) no notebooks allowed exam scheduled in Q2 (January 23th) and Q3 (April 17th)

16 16 Course material book J. Fraden, Handbook of Modern Sensors: Physics, Designs, and Applications, ISBN available online from Springer additional material from OASE Introducing Electronics Signal processing: the basics slides, instruction exercises, old exams video lectures from (no instructions) videocollege.tue.nl

17 17 Course material exercises and short questions embedded in slides marked in bold with question mark solutions provided on slides instructions exercises available on the website solutions provided on blackboard, not available online exams some previous exams available on the website no answers or solutions provided (ask in case of doubt) one exam will be practiced in week 14

18 18 A few words on 5CI31 week 1 Sept 4/6 week 2 Sept 11/13 Studenten EE, N, BMT week 3 Sept 18/20 week 4 Sept 25/27 week 5 Oct 2/4 week 6 Oct 9/11 week 7 Oct 16/18 week 8 Oct 23/25 Woe, uur 7-8 MF 07 Vri, uur 3-4 MF 07 Vri, uur 7-8 PT 6.05 X Instructions X Instructions Instructions X Instructions Instructions Actuators Actuators Actuators Displays Displays Actuators Actuators Actuators X Advanced Actuators Advanced Actuators Advanced Actuators Advanced Actuators Advanced Actuators Advanced Actuators Advanced Actuators week 1 Sept 4/6 week 2 Sept 11/13 Andere studenten week 3 Sept 18/20 week 4 Sept 25/27 week 5 Oct 2/4 week 6 Oct 9/11 week 7 Oct 16/18 week 8 Oct 23/25 Woe, uur 7-8 MF 07 Vri, uur 3-4 MF 07 Vri, uur 7-8 PT 6.23 X Instructions X Instructions Instructions X Instructions Instructions Actuators Actuators Actuators Displays Displays Actuators Actuators Actuators Intro to Electronics Intro to Electronics Intro to Electronics Intro to Electronics Intro to Electronics Intro to Electronics Intro to Electronics Intro to Electronics Actuators, Advanced Actuators, Instructions: Aleksandar Borisavljevic Displays: Gerard de Haan Intro to Electronics: Ruud Sprangers

19 19 Software for 5CI31 Download and install Maxwell SV software from

20 20 INTRODUCTION TO SENSORS (Chapter 1)

21 21 Sensors are everywhere...

22 22 Example Smartphone processing 5Mpixel camera LED flash speaker proximity/light sensor capacitive touch screen optical trackball buttons microphone

23 23 Sensors and actuators sensors and actuators are common devices a system of any complexity cannot be designed without them why can a system not perform its tasks without sensors? complexity uncertainty dynamic world detection / correction of errors

24 24 Information-processing systems information-processing system consist of sensors interface electronic circuits processing elements actuators interface electronics signal processing

25 25 Example Temperature control sense the temperature of a CPU control the speed of the fan to keep the temperature constant A/D and signal conditioner can be separated from the processor circuitry may be integrated into a smart sensor

26 26 Example Level control system information-processing system sensor (sight tube + optic nerve) processing (brain) actuator (hand + valve) this sensor converts radiant energy to electrical energy

27 27 Animal senses bats ultrasound (mechanical) shark electrical field snake thermal radiation rats touch (mechanical) fish sound vibrations (mechanical) birds magnetic field

28 28 Signals-carrying energy Signal domain Radiant Magnetic Mechanical Chemical Electrical Thermal Atomic Electrostatic / Electromagnetic Thermal Molecular Mass Mechanical Energy domain Radiant Nuclear Gravitational

29 29 Sensors, transducers and actuators Radiant direct sensor Magnetic Mechanical complex sensor Chemical Electrical Thermal a transducer converts a stimulus from a signal domain to another signal domain a sensor receives a stimulus and responds with an electrical signal an actuator converts an electrical signal to another signal domain

30 30 Example - loudspeaker system sensor actuator mechanical signal electrical signal mechanical signal a transducer converts a stimulus from a signal domain to another signal domain a sensor receives a stimulus and responds with an electrical signal an actuator converts an electrical signal to another signal domain

31 31 Electrical signal domain why do we prefer a transducer that produces a signal in the electrical domain? a signal in any domain can be converted to a signal in the electrical domain energy does not have to be drained from the processes being measured, instead an amplifier can be used many electrical signal conditioners exist many options exist to process, display and store electrical information it is easy to communicate electrical signals

32 32 Example - telephone sensor actuator mechanical signal electrical signal mechanical signal a telephone works in a different way microphone converts sound to change of resistance no transduction takes place (no change of energy) power source must be added to affect transduction

33 33 Sensor classification - excitation passive active an active sensor requires external power to operate a passive (self-generating) sensor generates its own electrical signal sensor classification 1 passive 2 passive 3 passive 4 active 5 passive

34 34 Sensor classification sensor placement a contact sensor requires physical contact with the object a non-contact requires no physical contact with the object an internal sensor is used within the data acquisition system itself sensor classification 1 passive non-contact 2 passive contact 3 passive contact 4 active contact 5 passive internal

35 35 Sensor classification reference point an absolute sensor reacts to a stimulus on an absolute scale a relative sensor senses the stimulus relative to a fixed or variable reference sensor classification 1 passive non-contact 2 passive contact 3 passive contact 4 active contact 5 passive internal

36 36 Sensor classification physical effect transducers (sensors) employ physical effects to convert a stimulus from a signal domain to another signal domain in \ out radiation mechanical thermal electrical magnetic chemical radiation photo luminance radiation pressure radiation heating photoconduction photomagnetic photo-chemical mechanical photo-elastic effect conservation moment friction heat piezoelectric magnetostrict. pressure induced explosion thermal incandescen ce thermal expansion heat conduction Seebeck effect Curie-Weiss law endothermic reaction electrical inject luminance piezo-electric Peltier effect pn-junction effect Ampere s law electrolysis magnetic Faraday effect Magnetostriction Ettinghaus en effect Hall effect Magnetic induction chemical Chemoluminance Explosive reaction Exotherma l reaction Volta effect Chemical reaction

37 37 Sensor classification type / quantity measured S e n s o r t y p e Position, distance, displacement Quantity Flow rate / Point velocity Force Resistive Magnetoresistor Thermistor Strain gage RTD Potentiometer Capacitive Differential capacitor Capacitive strain gage Inductive and electromagnetic Selfgenerating Eddy currents LVDT Load cell + LVDT Hall effect LVDT Magnetostriction Thermal transport + thermocouple Magnetostriction Piezoelectric sensor Temperature Thermistor PN junction Photoelectric sensor Diode Pyroelectric sensor Thermocouple Bipolar transistor Digital Position encoder Quartz oscillator Optic Ultrasound Travel time Doppler effect there are many other interesting quantities: acceleration, vibration, humidity, level, pressure, velocity,...