Development and Deployment of ZigBee Wireless Sensor Networks for Precision Agriculture in Sugarcane Field

Transcription

1 Development and Deployment of ZigBee Wireless Sensor Networks for Precision Agriculture in Sugarcane Field by Kamol Kaemarungsi (Ph.D.) Embedded System Technology Laboratory National Electronics and Computer Technology Center (Thailand) February 16, 2012 Asia-Pacific Advanced Network (APAN) 33 rd Chiang Mai

2 Outline Background Research Team & Tasks Sugarcane Agriculture ZigBee WSN and Remote Monitoring System Design & Deployment Problems Concluding Remarks 2

3 Background of Project Collaboration between electrical engineers and agricultural researchers Applied wireless sensor networks in agriculture Utilize ZigBee WSN standards Assist agricultural researchers in studying different irrigation techniques in sugarcane fields Moving toward precision agriculture 3

4 Research Team & Tasks Staffs of Embedded System Laboratory (EST) at NECTEC 1 Project leader 2 Researchers (2 Ph.D.) 9 Research assistants Tasks System level design Embedded hardware design Embedded software development Integration Installation Maintenance Web server for data logging and retrieval Collaboration with agricultural researchers from another institute We are electrical engineers and we are not experts in agriculture 4

5 Embedded System Laboratory (EST) Mission: Electronics and ICT for Agriculture and Environment 5

6 Some Facts about Sugarcane Thailand is one of the world leaders in sugarcane production Cane accounts for 80% sugar produced Sugarcane used to produce ethanol, key ingredient in gasohol (ethanol+gasoline) such as E85 Sugarcane is easy to grow and can tolerate some flood or drought Once growth, it can be cultivated more than once One crop cycle is almost a year (10-11 months ~ 330 days) Can grow as high as 4 meters Problems of low yield due to several factors such as water, fertilizer, diseases, and insects Still need new techniques to improve production 6

7 Sugarcane Field in Thailand 7

8 Types of Sugarcane Irrigation Furrow irrigation Low cost, easy, required flat field, 30-90% water efficiency Sprinkler irrigation Suitable for any landscape, >75% water efficiency Drip irrigation Most water efficient technique, can focus on roots, can be mixed with fertilizer and pesticide Surface system Subsurface system Question for sugarcane: Which one is the best that provide highest yield with least water usage? 8

9 Background on ZigBee Standards Low-cost, low-power wireless sensor and control networks Can be used almost anywhere, easy to implement and needs little power to operate No Agricultural Profile so far from 9

10 ZigBee Wireless Sensor Network Develop on top of IEEE standards of wireless communications Use 2.4GHz unlicensed radio channels (16 channels) Theoretical max. data rate 250kbps Maximum transmitted power 100mW (+20dBm) Range between 10m up to 1,000m (with extra power amplifier and special external antenna) Support star tree and mesh topologies Low power consumption and can operate with batteries Support Advanced Encryption System (AES) 128 bits Theoretically, can have more than 65,000 nodes per network 10

11 Types of ZigBee Nodes ZigBee Coordinator (ZC) Forming a network and select identity of network (Personal Area Network Identifier (PAN ID)) Allow devices to join/leave network Perform function of ZigBee router ZigBee Router (ZR) Route data between devices in network Allow devices to join/leave network Manage messages for its children (end devices) ZigBee End Device (ZED) A reduced function device Can sleep to save power/battery powered Report sensor states ZC ZR ZED 11

12 ZigBee s Mesh Network ZED ZR Direct communicate ZR ZED ZED ZC ZED ZED ZR ZR ZED Child-parent relationship ZED ZED ZED 12

13 System Design Objectives Our team already has proprietary wireless sensor network platform Based on in-house protocol called A1 ~ round robin polling based protocol, less energy efficient Uses Texas Instruments MSP430 microcontroller and CC1100 Low Power Radio Frequency Chipset (@ 433MHz) Can collect sensor data of various types such as soil moisture, temperature, relative humidity, wind speed, light intensity, rain volume etc. Successfully used in several of our previous projects Need to move on to more standardized system such as ZigBee standards, which uses 2.4GHz unlicensed band Need to combine existing platform with new wireless standard Gradually migrate existing platform to ZigBee platform 13

14 Sensing Requirements Soil moisture sensors used to compare water in different irrigation techniques Weather station is also needed to measure Temperature & relative humidity Wind speed & direction Precipitation (rain volume) Light intensity Pressure sensors for water in irrigation pipes Water level sensors for determining the change in near by water reservoir 14

15 Remote Monitoring System Sensor Data Logger IP Gateway GPRS/GSM GPRS GPRS/GSM A1 Bus Wireless Node Energy Management IP Gateway Ethernet IP Wireless Sensor Network IP IP Network Wireless Node A1 Bus Wireless Node A1 Bus Database Application Server IP Sensor Sensor 15

16 In-field System Design with ZigBee 430+ZB 430+ZB 430+ZB 430+ZB 430+ZB 430+ZB Weather Station Gateway Row head node Row head node Row head node Row head node WL ZB SM SM SM SM SM ZB SM ZB SM ZB SM ZB Root Drip Surface Drip Mini Sprinkler Surface flood 16

17 Soil Moisture Sensor (In-house) Measuring Range 0-40% by volume Low Salinity Effect Stability time <1 sec Low cost 40 Soil Moisture Content (%by Volume) 35 Low Power (< 6 ma, 5 volt) 30 f(x) = 56.95x R² = 0.99 Maintenance free Small size and Easy Install Vout (Volt)

18 NECTEC s Proprietary WSN Platform MSP430 MCU and CC1100 RF mezzanine I/O module MCU, RF Ethernet Gateway module (to wired network) GPRS Gateway module (to cellular wireless) 18

19 Used of NECTEC s Proprietary WSN Platform in Weather Station (Field Server) Sensors: -Temperatue -Humidity -Wind -Rain -Soil Moisture -Light Powers: -Solar Cell -Batter/Charger I/O module 19

20 Specification of ZigBee Chipset Freescale MC13224v $4.50 qty. ARM7TDMI-S 32-bit MCU LGA145~ 9.5x9.5mm 99 pins Tx~ -30dBm- +4dBm 24MHz and/or kHz Clock Supply 2V 3.6V Temp C IEEE with MAC Accelerator (MACA) 2.4 GHz (center freq MHz) 16 channels (Ch.11-26) Tx power -30 to +4dBm typ. Rx sensitivity < -96dBm in DCD mode < -100 dbm in NCD mode Link budget = 104 db Support Clear Channel Assessment (CCA), Energy Detect, Link Quality Indication (LQI) Chip from Freescale Integrated Module with Power Amp. from CEL. 20

21 NECTEC s ZigBee Platform 21

22 ZigBee Wireless UART Application Customized application object in ZigBee stack Communicate with existing sensor and I/O platform via UART (serial) interface New ZigBee platform responsible for all wireless communication No sensing function in ZigBee software Relay all sensor data from all nodes to gateway node Old sensor and I/O platform controlled by software in MSP430 microcontrollers Shorten development time by using existing sensing platform 22

23 Deployment Commissioning: Forming of ZigBee network is done in our laboratory before on-site installation, configuration is saved in non-volatile memory (NVM) Field installation is simple with no network formation needed, just physical installation We opted to deploy only router nodes without coordinator node at actual site Due to limited time, no end device nodes were deployed at this time No optimization for energy efficient of all sensor node in networks (no sleep or doze) Two different locations: Ratchaburi and Nakorn Ratchasima 23

24 Site Ratchaburi 24

25 Sprinkler Irrigation in Sugarcane Plot 25

26 Node Placement at Nakorn Ratchasima Site Plot 1 Plot 2 Plot 3 ZR ZR ZR 40 m. Gateway GPRS Sugarcane field Plot 4 ZR ZR ZR Weather station ~200 m. Sugarcane field 20 m. ZR Repeater ZR Water reservoir 26

27 Nakorn Ratchasima 27

28 Weather Station in Sugarcane Field 28

29 Gateway to GPRS (Cellular Network) 29

30 Web Interface for Remote Monitoring 30

31 Soil Moisture Data in August

32 Summary of Problems Intermittent data loss Unexpected node left network (due to wrong rejoining mode or configuration in our 1 st installation) Height of sugarcane s leaves block communication links after they grew to 3-4 meters Node after a repeater was disconnected for unknown reason (possible multiple retries and timeouts) ZigBee coordinator cannot rejoin its own network after unknown leave from network New system still rely on old sensor & I/O platform, overall size of the sensor node is still large 32

33 Future Works Migrate all sensing task from MSP430 (16bits) to ZigBee ARM7TDMI-S (32bits) platform Change application from wireless UART to sensor application in ZigBee stack Add end device nodes which can save energy by sleep or doze Find the way to reduce the effect of changes in environment Blocking of signal due to grown leaves of sugarcane 33

34 Concluding Remarks Comparison of irrigation techniques and their results need to be judged by agricultural experts Our team provides studying tools (WSN) and database of sensor records for later analysis Experience from this work will allow us to improve the new WSN system for the future deployment and application New software to avoid loss of sensor data Increase the reliability of the whole network More nodes in the network such as end devices Focusing on saving energy usage of WSN Smaller size for ZigBee node Integrating of ZigBee node with various sensor devices 34

35 Thank you Embedded System Technology Laboratory National Electronics and Computer Technology Center 112 Thailand Science Park, Paholyothin Rd., Klong 1, Klong Luang, Pathumthani, Thailand 35