Hardware Components Sensors Actuators Converters Nikil Dutt UC Irvine ICS 212 Winter 2005 Copyrighted Material adapted from Peter Marwedel Frank Vahid and Tony Givargis Templates from Prabhat Mishra ICS212 WQ05 Dutt Hardware Components Sensors Actuators Converters 1 Simplified Block Diagram actuators ICS212 WQ05 Dutt Hardware Components Sensors Actuators Converters 2 Sensors and Actuators Sensors Capture physical stimulus e g heat light sound pressure magnetism or other mechanical motion Typical generate a proportional electrical current May require analog interface solenoid mic speaker Actuators Convert a command to a physical stimulus e g heat light sound pressure magnetism or other mechanical motion May require analog interface laser diode transistor compass dc motor ICS212 WQ05 Dutt Hardware Components Sensors Actuators Converters accelerometer 3 Sensors Processing of physical data starts with capturing this data Sensors can be designed for virtually every physical stimulus heat light sound weight velocity acceleration electrical current voltage pressure Many physical effects used for constructing sensors law of induction generation of voltages in an electric field light electric effects ICS212 WQ05 Dutt Hardware Components Sensors Actuators Converters 4 Example Acceleration Sensor MEMS device Small mass in center When accelerated Mass displaced from center Resistance of wires connected to mass change Detect change in resistance and model acceleration Courtesy S B tgenbach TU Braunschweig ICS212 WQ05 Dutt Hardware Components Sensors Actuators Converters 5 Charge coupled devices CCD Image ImageSensors Sensors Based Basedon oncharge chargetransfer transferto tonext nextpixel pixelcell cell ICS212 WQ05 Dutt Hardware Components Sensors Actuators Converters 6 CMOS Image Sensors Based on standard production process for CMOS chips allows integration with other components ICS212 WQ05 Dutt Hardware Components Sensors Actuators Converters 7 Source B Diericks CMOS image sensor concepts Photonics West 2000 Short course Web Comparison CCD CMOS sensors ICS212 WQ05 Dutt Hardware Components Sensors Actuators Converters 8 Example Biometric Sensors Example Example Fingerprint Fingerprint sensor sensor Siemens Siemens VDE VDE Integrated into ID mouse ICS212 WQ05 Dutt Hardware Components Sensors Actuators Converters 9 Example Artificial eyes Dobelle Institute www dobelle com ICS212 WQ05 Dutt Hardware Components Sensors Actuators Converters 10 Artificial eyes 2 Dobelle Institute www dobelle com He looks hale hearty and healthy except for the wires They run from the laptops into the signal processors then out again and across the table and up into the air flanking his face like curtains before disappearing into holes drilled through his skull Since his hair is dark and the wires are black it s hard to see the actual points of entry From a distance the wires look like long ponytails ICS212 WQ05 Dutt Hardware Components Sensors Actuators Converters 11 Other examples of sensors Heart monitoring sensors Managing Care Through the Air IEEE Spectrum Dec 2004 Rain sensors for wiper control High end Pressure Touch autos sensors pads screens Proximity sensors Collision avoidance Engine control sensors Audio sensors Motion sensors Thermal sensors SARS detection high fever ICS212 WQ05 Dutt Hardware Components Sensors Actuators Converters 12 Simplified Block Diagram actuators ICS212 WQ05 Dutt Hardware Components Sensors Actuators Converters 13 Sensors and Actuators Sensors Capture physical stimulus e g heat light sound pressure magnetism or other mechanical motion Typical generate a proportional electrical current May require analog interface solenoid mic speaker Actuators Convert a command to a physical stimulus e g heat light sound pressure magnetism or other mechanical motion May require analog interface laser diode transistor compass dc motor ICS212 WQ05 Dutt Hardware Components Sensors Actuators Converters accelerometer 14 Actuators Output physical stimulus varies in range and modality Large industrial control actuators Pneumatic Optical systems physical motion output IR Thermal output Small motor controllers stepper motors MEMS devices List goes on ICS212 WQ05 Dutt Hardware Components Sensors Actuators Converters 15 Stepper Motor Controller Stepper motor rotates fixed number of degrees when given a step signal In contrast DC motor simply rotates when power applied and coasts to stop Rotation achieved by applying specific voltage sequence to coils Controller greatly simplifies this ICS212 WQ05 Dutt Hardware Components Sensors Actuators Converters 16 MEMS Actuators Huge variety of actuators and output devices Microsystems motors as examples MCNC Dimensions in the order of several microns MCNC ICS212 WQ05 Dutt Hardware Components Sensors Actuators Converters 17 Actuators Courtesy and E Obermeier MAT TU Berlin ICS212 WQ05 Dutt Hardware Components Sensors Actuators Converters 18 Simplified Block Diagram actuators ICS212 WQ05 Dutt Hardware Components Sensors Actuators Converters 19 Sample and Hold Circuit Model Vx Ve when Clock 1 Sampling how often the signal is converted Quantization how many bits used for sampling ICS212 WQ05 Dutt Hardware Components Sensors Actuators Converters 20 Aliasing Potential Consequence of sampling e g Signal frequency 5 6 Hz Sampling frequency 9 Hz ICS212 WQ05 Dutt Hardware Components Sensors Actuators Converters 21 Analog to Digital Conversion Sampling how often is the signal converted Twice input as high as the highest frequency signal present in the Quantization how many bits used to represent a sample Sufficient to provide required dynamic range Under loading dynamic range not used properly Clipping input signal beyond the dynamic range Aliasing erroneous signals not present in analog domain but present in digital domain Use anti aliasing filters Sample at higher than necessary rate ICS212 WQ05 Dutt Hardware Components Sensors Actuators Converters 22 Analog to Digital Converter 3 0V 2 5V 2 0V 1 5V 1 0V 0 5V 0V 4 4 3 3 2 2 analog input V 5 0V 4 5V 4 0V 3 5V 1111 1110 1101 1100 1011 1010 1001 1000 0111 0110 0101 0100 0011 0010 0001 0000 analog output V Vmax 7 5V 7 0V 6 5V 6 0V 5 5V 1 1 t1 0100 proportionality ICS212 WQ05 Dutt Hardware Components Sensors Actuators Converters t2 t3 t4 time 1000 0110 0101 Digital output analog to digital t1 t2 0100 t3 1000 0110 Digital input t4 time 0101 digital to analog 23 Flash A D Converter Parallel comparison with reference voltage Speed O 1