Deploy my first wireless sensor network.

1.                 I just deployed my first wireless sensor network.

            Here are some comments for this job.

Hardware

The gateway (base station) is MIB520, the sensor node is MICAz, and the sensor board is MTS310. The frequency is 2.4 GHz. The communication protocol is Zigbee.

I installed MIB 520 through USB hub, and it brought me two virtual com ports. Use this MIB board, I wrote the initiation XMesh program to set up node0 (base station), and node1-2.

Software

There are 3 software tiers in my installation, first for Mote Tier, 2^nd for Server Tier, and the last one for client tier. I got them from the latest MoteView (v 2.0) from Xbow website.

Data acquisition from sensor notes.

XServer run in my local PC to serve as a base station. The database we use to collect data is PostergreSQL.

Use MoteView to start XServer, and connect the sensor nodes online, we can get the data from each node, including voltage, temperature, light and so on. The server logs show us that, it use a standard INSERT statement to insert data rows to DB.

Query: INSERT into mts310_results (result_time,nodeid,parent,voltage,temp,light,accel_x,accel_y,mag_x,mag_y,mic) values (now(),2,0,444,510,857,451,465,791,206,446)

How to track a target?

I am studying KF to know how to track a target.

 

2.                 The Database Model in Application Layer.

There are some distributed database model and management system including TinyDB, Cougar, Dimensions have been proposed. I compared these three models in the attached slides.

In my opinion, the signal processing related with physical layer while database (NOT data) model lies on application layer.

Attachment 2 is a latest paper from TinyDB group. Do you think it is more suitable for me than signal processing?

To clear my research boundary

1.                   Data acquisition

1.1     What is data acquisition?

Data acquisition (DAQ, DAS for short) is the sampling of the real world to generate data that can be manipulated by a computer.

It consists of acquisition of signals and waveforms and processing the signals to obtain desired information.

 

1.2     How to acquire data?

Step 1: Set up an object we want to investigate, e.g. an island.

Step 2: Determine which physical phenomenon or physical property of the object investigated will be measured, e.g. temperature or temperature change.

Step 3: Use some sensors (i.e. transducers) to measure.

Step 4: We will get digital/analog signals, i.e. raw signals.

Step 5: Signal conditioning is necessary if the raw signals are not suitable for DAQ hardware.

Step 6: There is a DAQ hardware connected with PC to get the dataset (signals). Also, there is software (e.g. LabView of NI) allows the OS to recognize the DAQ hardware and program to access the signal being read by the hardware.

Step 7: We can use MATLAB to do signals processing.

 

2.                   Data Analysis and Data mining

Data analysis is the process of looking at and summarizing data with the intent to extract useful information and develop conclusions.

Data mining tends to focus on larger data sets, with less emphasis on making inference, and often uses data that was originally collected for a different purpose.

 

3.                   Data Model

3.1     What is Data Model?

A data model in software engineering is an abstract model that describes how data is represented and accessed.

In database model theory, there are four kinds of data model, i.e. Flat model, Hierarchical model, Network Model and Relational Model. There are many other kinds of data model for different purpose. For example, in Geographic Data Model, some special model proposed to make up 2D and 3D maps.

Also, in WSN, we need to develop a new data-driven model to suit for the limited energy and communication resource.

3.2     How many kinds new Database Management has been proposed for WSN?

(1)     Tiny DB from Univ. of California, Berkeley.

        The Design and Evaluation of a Query Processing Architecture for Sensor Networks

(2)     Cougar from Cornell University.

                        Query Processing for Sensor Networks

(3)     DIMESION from University of California, Los Angeles

       DIMENSIONS: Why do we need a new Data Handling architecture for Sensor Networks?

3.3     What is the relationship between DB Model and Data Acquisition?

In Data Acquisition System, we use hardware to acquire data from sensor networks. Between Step 3 and 4 of last section, we should determine which data should be collected? What kind of model will be used when they acquired by the machine?

Actually, due to the computation ability of WSN nodes, we will pre-process the data before they were acquired by the hardware, i.e. prior to signals.

 

Reference: http://en.wikipedia.org/wiki/Data_acquisition

http://www.adinstruments.com/products/data-acquisition/corporate/

BondMaster for NDT

What I have done these days?

• 1. Search and read more materials regarding BondMaster. 
  

Especially, an application guide downloaded from Olympus website show me five inspection methods including,
(1). Pitch-Catch Test Mode

• (1a) Pitch-Catch RF Method
  
• (1b) Pitch-Catch Impulse Method
  
• (1c) Pitch-Catch Swept Method
  

(2). MIA Mode
(3). Resonate Mode.
Comparing with the thesis, both of them explain the theories and give me some examples.
Currently, I have a general comprehension on Non-Destructive Testing.

• 2. Read and learn your Matlab code.
  

I have read your Matlab code and learn the functions. I have to start from the scratch to recall much minor knowledge, such as what is FFT or when we should use it. Basically, I can explain your code myself as below:

(1) Load the data from .mat file, declare 1st column as input, 2nd as output.
(2)Apply a high pass filter to output.
(3)Use FFT to output;
(4)Repeat the process to each specimen.

• Current questions and difficulties:
  

1. I am a little puzzled about Numerical Analysis and Signal Processing, both of them are not similar for me.  Would you please tell me what is the field of our current topic?

2. I should brush up much knowledge to push my research. Would you please let me know what is urgent?

3. Here are some questions for you. Thanks for your kindly reply:

Q1. What are the data we acquired from BondMaster stand for?
There are two columns in the data file for each Exp0…Exp9. You declare the first column as input(x), while the second one as output(y).
But according to the thesis, we use probe tips to touch the specimens, then the instrument give us back some signals, such as the phase and amplitude. How we can acquire these data? What kind of data in start_m.mat have recorded?

Q2. What do the original Time-Data plots (Page 4 of slides) stand for?
The X axes maybe time. What do Y axes stand for? Input(x) or output(y)?

Q3. How can I use my own data? What’s the difference between them and yours?
My own data only contains position info (x, y position). They are different with yours, and maybe not suitable for inspection.
Attachment is an excel I got from our current equipment in my lab. Please take a look.

Next, I will
I am going to try my best to write a little paper base on the materials you send me. An outline will be proposed soon.

Questions waiting for answer.
Q4. How to introduce the project to others? What is the main process of this project?
We fabricated 12 different specimens to simulate the composite in F-16. Use these specimens, we The Non-Destructive Testing(NDT)
(1) We fabricated 12 specimens.
(2) Use Bond
Q5. What is Fourier series? What is FFT? When we should use FFT?
Q6. What is the outline/structure of this paper?

Report on “Non-destructive inspection of aircraft structures”

What I have done these two days are:
Review the project report from Mr. /Miss. Tan. I paid much more attention to 1)Introduction; 2)Literature Review; 3)Results and discussion; 4) conclusion and recommendation.

This work helps me to
1) recall some basic knowledge regard signal process. But I need more time to clear up this part;
2) learn the information about Sonic BondMaster with its four modes of testing ( Resonance Test, Pitch/Catch Swept and Impulse, MIA)
3) know the general technical operation procedures of testing including specimens fabrication and inspection procedure.

There are some questions needs your kindly reply:
Q1) what is loaned NI system? What is the relativity with Sonic BondMaster? How can you acquire the data set?

Q1) we used the National Instrument (NI) equipment to record the data, this is call BondMaster equipment. We have the machatronic lab in Level 1 to for the experiment.

Q2) the test specimens are same as those in last report on Sonic BondMaster, right?

Q2) Test Specimen is the same. If you would like to have a look, I can show it to you. 

Q3) the first step is data acquisition and analysis. Would you please let me know some detailed topics?

Q3) I used different signal processing techniques, such as wavelet, hulber huang, FFT, Stastical analysis…….The option is open.

Q4) what does “data model” mean you mentioned last time. I got my own data in my lab. It is produced by a program and saved in a .txt file. The records are serials of distances(x, y position) and Sensor Nodes ID. It seems different with those for defects detection.

Q4) Maybe you can send me the data, relevant figures, picture. I will have a look. And tell me what data is that.

What I am going to do next:
 Try to read the .m file in Matlab to discovery some more information.