High density coal dust CO can not disperse into the air poisonous gas
Four tasks:
Four tasks:
locate individuals
locate collapsed holes
measure and forecast seismic shifts
measure the concentration of gases
Challenges (extreme hostile environment for radio communication)
turns and twists of underground tunnels impossible to maintain a line-of-sight communication link signals being highly reflected, refracted, and scattered
high percentage of humidity signal absorption and attenuation is extremely high
The Sensing Subsystem
The Sensing Subsystem
Analog-to-Digital Converter
The Processor Subsystem
Architectural Overview
Microcontroller
Digital Signal Processor
Application-specific Integrated Circuit
Field Programmable Gate Array
Comparison
Communication Interfaces
Serial Peripheral Interface
Inter-Integrated Circuit
Summary
Prototypes
The IMote Node Architecture
The XYZ Node Architecture
The Hogthrob Node Architecture
Wireless sensor nodes are the essential building blocks in a wireless sensor network
Wireless sensor nodes are the essential building blocks in a wireless sensor network
sensing, processing, and communication
stores and executes the communication protocols as well as data processing algorithms
The node consists of sensing, processing, communication,and power subsystems
trade-off between flexibility and efficiency – both in terms of energy and performance
The Sensing Subsystem
The Sensing Subsystem
Analog-to-Digital Converter
The Processor Subsystem
Architectural Overview
Microcontroller
Digital Signal Processor
Application-specific Integrated Circuit
Field Programmable Gate Array
Comparison
Communication Interfaces
Serial Peripheral Interface
Inter-Integrated Circuit
Summary
Prototypes
The IMote Node Architecture
The XYZ Node Architecture
The Hogthrob Node Architecture
The sensing subsystem integrates
The sensing subsystem integrates
The Sensing Subsystem
The Sensing Subsystem
Analog-to-Digital Converter
The Processor Subsystem
Architectural Overview
Microcontroller
Digital Signal Processor
Application-specific Integrated Circuit
Field Programmable Gate Array
Comparison
Communication Interfaces
Serial Peripheral Interface
Inter-Integrated Circuit
Summary
Prototypes
The IMote Node Architecture
The XYZ Node Architecture
The Hogthrob Node Architecture
ADC converts the output of a sensor - which is a continuous, analog signal - into a digital signal. It requires two steps:
ADC converts the output of a sensor - which is a continuous, analog signal - into a digital signal. It requires two steps:
the analog signal has to be quantized
allowable discrete values is influenced :
(a) by the frequency and magnitude of the signal
(b) by the available processing and storage resources
2. the sampling frequency
Nyquist rate does not suffice because of noise and transmission error
resolution of ADC - an expression of the number of bits that can be used to encode the digital output
The Sensing Subsystem
The Sensing Subsystem
Analog-to-Digital Converter
The Processor Subsystem
Architectural Overview
Microcontroller
Digital Signal Processor
Application-specific Integrated Circuit
Field Programmable Gate Array
Comparison
Communication Interfaces
Serial Peripheral Interface
Inter-Integrated Circuit
Summary
Prototypes
The IMote Node Architecture
The XYZ Node Architecture
The Hogthrob Node Architecture
The processor subsystem
The processor subsystem
interconnects all the other subsystems and some additional peripheries
its main purpose is to execute instructions pertaining to sensing, communication, and self-organization
It consists of
processor chip
nonvolatile memory - stores program instructions
active memory - temporarily stores the sensed data
