8/26/2012<br />
<br />
Ch. 3 DAS<br />
DATA ACQUISITION SYSTEMS<br />
• DAS overview<br />
• Measurement, sensors, transducers<br />
• Conditioners, các bộ chuẩn hóa tín hiệu<br />
• MUX, S&H, ADCs<br />
• Microcontrollers and Data Processing<br />
• Database<br />
• Case studies: monitoring systems<br />
Ch3 - DAS<br />
<br />
1<br />
<br />
3.1. DAS Overview<br />
• Define:<br />
– Data Acquisition System: The system for acquiring<br />
data (status, metric information) from industrial<br />
processes (or environment) then update to<br />
database, one of importance part of a SCADA,<br />
DCS…<br />
– The collection of sensors and communication links<br />
to sample or collect and then return data to a<br />
central location for further processing, display, or<br />
archiving.<br />
<br />
• Structure: next<br />
Ch3 - DAS<br />
<br />
2<br />
<br />
1<br />
<br />
8/26/2012<br />
<br />
3.1. DAS Overview<br />
<br />
Ch3 - DAS<br />
<br />
3<br />
<br />
3.1. DAS Overview<br />
• Student’s define for structure:<br />
–<br />
–<br />
–<br />
–<br />
–<br />
–<br />
–<br />
–<br />
<br />
Object:<br />
Sensor:<br />
Conditioner: WorkBench, LabView<br />
MUX:<br />
S&H:<br />
ADC:<br />
Embedded System<br />
Computer Desktop: database and networking<br />
<br />
Ch3 - DAS<br />
<br />
4<br />
<br />
2<br />
<br />
8/26/2012<br />
<br />
3.1. DAS Overview<br />
• Operate:<br />
–<br />
–<br />
–<br />
–<br />
–<br />
–<br />
–<br />
<br />
Process<br />
Sensor<br />
Conditioner<br />
MUX<br />
S&H and ADC<br />
ES<br />
Database system<br />
<br />
Ch3 - DAS<br />
<br />
5<br />
<br />
3.1. DAS Overview<br />
• Classification:<br />
–<br />
–<br />
–<br />
–<br />
<br />
The number of data elements/points,<br />
Distance/wide area<br />
Rate of signal<br />
Address of application and type of information:<br />
• Industrial fields: level, flow, temperature, pressure,… in<br />
cement, paper, textile, steel mill, mechanical factories…<br />
• Civil engineering: dams, bridges, underground/ underwater constructions, high building… => constructions<br />
supervision system<br />
• Environmental supervision system<br />
Ch3 - DAS<br />
<br />
6<br />
<br />
3<br />
<br />
8/26/2012<br />
<br />
3.1. DAS Overview<br />
• Transportation: Vehicles, ship, aero plane: velocity,<br />
accelerate, gasoline ratio, safety equipment,<br />
Navigation…; Traffic signals<br />
• Bio-medicine: Cardiograph, Monitoring, smart garden<br />
and growth<br />
• Defense: DGPS,<br />
• Entertainment:<br />
• Smart house: temperature, lighting, air conditioning<br />
(heating/ freezing), plant watering, auto-answering,<br />
smart cooking… iBMS<br />
<br />
Ch3 - DAS<br />
<br />
7<br />
<br />
3.1. DAS Overview<br />
• Questions and Answers<br />
• Student’s examples<br />
<br />
Ch3 - DAS<br />
<br />
8<br />
<br />
4<br />
<br />
8/26/2012<br />
<br />
3.2 Measurement<br />
• Sensor Defines:<br />
– Là thiết bị nhận các tín hiệu vật lý từ thế giới thật (nhiệt, ás,<br />
âm thanh, áp suất…), tạo ra các tín hiệu điện tương ứng.<br />
(A device that responds to a physical stimulus in real world (heat, light, sound, pressure, motion, flow,<br />
and so on), and produces a corresponding electrical signal)<br />
<br />
– Là một phần của thiết bị đo, nó đáp ứng trực tiếp ứng với<br />
sự thay đổi của môi trường (The part of a measuring instrument which responds<br />
directly to changes in the environment)<br />
<br />
• Transducers are ENERGY CONVERTERS or<br />
MODIFIERS<br />
– Là thiết bị thay đổi năng lượng từ dạng này sang dạng khác<br />
(A device for converting energy from one form to another)<br />
<br />
– For example, a thermocouple transduces heat energy into<br />
electrical energy<br />
<br />
• (Tuy nhiên trong thực tế thường hay coi là 1)<br />
9<br />
<br />
Ch3 - DAS<br />
<br />
3.2.1. Sensor characteristics<br />
•<br />
•<br />
•<br />
•<br />
<br />
Transducers, sensors và phép đo<br />
Calibration, interfering và thay đổi tín hiệu vào<br />
Static sensor characteristics<br />
Dynamic sensor characteristics<br />
<br />
Ch3 - DAS<br />
<br />
10<br />
<br />
5<br />
<br />