ARTICLE AQUATIC ECOSYSTEM MONITORING REMOTE VEHICLE.

This paper reports the Underwater Vehicles for Surveillance and Monitoring Aquatic Ecosystem. The acceptable range of pH for aqua environment is between pH 6.0 to pH 8.0. Different problems associated with aquatic ecosystem due to water pollution are increasing pH and temperature due to global warming and decrease of dissolved oxygen. This is endangering the various aquatic species. Besides this, water becomes unusable for drinking, farming and for general work. So a microcontroller based un-manned vehicle for monitoring the water purity parameters viz.; pH and temperature using wireless communication is presented here. It has a aqua monitoring unit which continuously monitors the purity of water and sends an alarm to the central monitoring unit in case the water turns abnormal acidic/alkaline and gives an information on speed of wind, floating debris, possibility on earth quake through earthquake signals sensed in water etc. This helps for ensuring the safety of aquaculture

3) pH sensor: pH sensor is used indicate the acidity/alkalinity of a water resource. CSL 31 is an analog sensor with glass body, refillable, ceramic diaphragm pH electrode with low noise co-axial cable. 4) Wind speed sensor: Wind speed sensor used in this project is a 5V DC voltage which generates dc voltage in accordance with wind speed. By using a standard formula we can calculate the speed of air. 5) Vibration sensor: Vibration sensor based on Piezo-electric principle is used to detect the turbulence of water resource. It produces voltage proportional to the vibration present around the aquatic vehicle.

6) Ultrasonic sensor:
Ultrasonic sensor is used to detect the obstacles coming in front of AEMV which produces a trigger pulse and echo pulse to detect the obstacle. If the obstacle is too close to AEMV, then AEMV gets automatically reversed. 7) LCD display: LCD is used to display the measured values of temperature and pH of water with the help of 16X2 LC.

8) Zigbee
Module: Aquatic signals monitored by AEMV are sent to central unit to using wireless control.
Hence, Zigbee module CC2500 is used as the wireless transmission and reception of data. 9) DC motor and mechanical assembly: DC motors operating at 12 volts are used for the movements of AEMV such as forward, backward and left, right movements. Also we require geared DC motors along with appropriate DC driver IC i.e. L293D. Also some mechanical arrangement is used for the movements.

1)
In this, arduino development board is used to dump the aqua monitor code in the IC ATmega328. Components used for AEMV are tabulated in Table I  Wind speed sensor: For the constant flow of water, it is required to have constant air flow surround water resource. To detect the wind speed, a 5V dc motor with turbines is used. Whenever the air flow appears across turbines, turbines starts rotating and creating a dc voltage. This voltage value is taken as input and by using a standard formula in (1) the wind speed in meter/seconds is computed. The formula used to derive wind speed is as follows. Vibration sensor: As the epicentre of maximum earthquakes are in water resources, so a vibration sensor has been used to detect sudden change in water turbulence. AEMV will be rerouted and it will sank in water. A piezo-electric sensor is used to detect the turbulence which is simple and has high sensitivity.  Table II gives the detail of the port pins of ATMega328 controller used for interfacing the peripherals such as ADC, LCD, Motor driver, sensors etc. The component used, port pins of Arduino, for interfacing various pins of components are tabulated in Table II. Total of 18 port pins of processor are used for this purpose. Wi-Fi module CC2500 a wireless transceiver help to transmit the parameters of water pH, temperature. Wind sensor measured by ATMEGA328 from DS18B220, CSL 31 sensors respectively to the controller of AEMV. According to these values status of aqua water is detected by AEMV.

1) Selection of ATMega328 pins for peripheral interfacing
IC L293D is used to drive the DC motor.
[9] A 5V supply is directly used as Enable input for the Driver IC. Also we have used pins 15, 16, A5 and A4 to control the backward and forward motion of DC motors. The purpose of these technique is to control the movement of AEMV.
A 16X2 LCD display in 4 bit mode is used to display the status of temperature and pH sensor and wind speed. Data lines of LCD from D0-D3 are connected to the port pins 11,6,5,4 respectively. Pin no. 17 is used for Enable input of LCD. And RS is given to pin no. 18 of ATmega 328.
Another important concept of our project is obstacle avoidance coming in the way ofAEMV. Echo pin and trigger pin is connected to 13 and 14 pin of ATmega 328 microcontroller respectively. Whenever an obstacle comes at a distance of 2 feet's the microcontroller sends a warning to the controller of AEMV and if the vehicle is too close to obstacle at distance minimum than 20cmAEMV automatically starts move in backward direction for 5 seconds and alert the operator to change the direction of AEMV, which gives enough distance to the AEMV to avoid the obstacle. PCB Design of the implemented Circuit Aquatic ecosystem monitoring vehicle starts its operation by taking the readings from temperature pH of water, and voltage corresponding to wind speed sequentially. These measured value are displayed on16x2 LCD and then transmitted to AEMV controller via wireless module CC2500. The samples are taken every one second. After this the program control checks regularly for turbulence and presence of obstacle warning every 2 and 5 sec respectively which then are sent wirelessly to AEMV. For obstacle too close to AEMV, it automatically reverses AEMV to avoid accident and give enough distance to AEMV to change its direction.

1) Decision Flow chart of pH sensor
Sensor used to measure the pH value of water is CSL 31 which is an analog sensor gives voltage variations as an output which is again mapped from 0 to 1023 by using internal 10 bit ADC of ATmega 328. For output is zero, <7, and >7 the pH reading corresponds to neutral, Acidic and Alkaline nature of water respectively. Resolution of pH sensor is 0.05. The temperature readings are taken using DS18B20 with respect to normal room temperature and higher temperature readings are taken with respect to heated water. The observation table of measured values with comparison of thermometer values is given below. The accuracy of DS18B20 is +/-1%. -Error obtained is in the range of -0.68% to 0.59% which is within ±1%.

2) pH Sensor Result:
The pH readings are taken with respect to different acids and bases such as HCL, KCl, H2SO4, NaOH, KOH etc. The different readings taken by pH sensor are compared by the traditional method of burette and conical flask method as stated in Table III. Error Range obtained is within ±-3.28 to 2.38%.

3) AEMV Results:
AEMV is integrated with different analog and digital sensors. Readings taken by the various AEMV unit sensors are transmitted using wireless system to the controller or supervisor continuously. Figure 8 shows the full system Set up. The readings taken by temperature sensor DS18B20 and pH sensor CSL 31 are shown on 16x2 LCD display of in Figure9.

4) Wireless module CC2500 on Hyper Terminal
The data from AEMV is transmitted to supervisor using wireless module CC2500 which uses 2.4 GHz ISM band. CC2500 module is used as a transceiver antenna which transmitts and receives data simulateously. The data transmitted via CC2500 module is received by receiver antenna connected to CH341SER module which converts the serially received data into supportable universal serial system of USB drivers. CH341SER is connected to USB port of personal computer from which the data is received and transmitted.

Figure(10):-Data received on a HyperTerminal
HyperTerminal is a open source free software which is used as a intermediate media between received data and personal computer. HyperTerminal is used to show the received data i.e temperature value, pH value, wind speed in meter/seconds, generated DC voltage, terbulance and warning if an obstacle comes in front ofAEMV. Figure 10. represents the data received on a HyperTerminal.

Conclusion & Future Scope:-
Remotely operated unmanned vehicle is implemented for monitoring, protecting and maintaining the Aquatic Ecosystem which is polluted due to waste chemicals from factories, oil spilling, accidents caused due to ships etc. It is found to provide a suitable solution to solve this aquatic problems. As the research in this field enhances and other innovations are introduced into the operations of unmanned underwater vehicles (UUVs), Underwater Vehicles and make more common and highly cost effective.

Future Scope:
 To install the device in the field, solar energy is a eco-friendly solution to meet the continuous power supply requirement for working of AEMV .  For the transmission of the data from the field to the control room and Pollution Control Department internet can be used for storing the data on cloud.