Mobile Controlled Multi-Tasking Rover with
Password Protection and Night Vision
Amritanshu Srivastava
1, Anjula Singh
2 1Shri Mata Vaishno Devi University Jammu, Jammu and Kashmir, India1
2011eec67@smvdu.ac.in
2Mahatma Jyotiba Phule Rohilkhand University Bareilly, Uttar Pradesh, India
2
anjulasingh8@gmail.com
Abstract— The methodology used in this manuscript is DTMF (Dual Tone Multi-Frequency) and GSM module. DTMF is used for telecommunication signalling over analog telephone lines in the voice-frequency band between telephone handsets and other communications devices and the switching centre. The version of DTMF that is used in push-button telephones for tone dialling is known as Touch-Tone. The same concept we have used it for designing this robot (rover) to facilitate the humans in the future for security purposes, controllable by cell phone having great versatility and various applications with key features such as password protection, night vision, automatic obstacles avoidance, gas sensing, smoke and edge detection and hence immediately providing an alert through text messaging to the calling person and above all wider coverage. This is how we can use this rover in different fields as well as for research purpose by further manipulation in programming and interfacing it can be modified accordingly.
Keywords—DTMF (dual tone multiple frequency); Sensors;
Rover; GSM module; Password Protection; Night Vision Camera; Display unit.
I. INTRODUCTION
Robotics is the branch of technology that deals with the design, construction, operation, and application of robots, as well as computer systems for their control, sensory feedback, and information processing. The design of a given rover will often incorporate human effort, though it may not look much like a human being or function in a human like manner. These types of intelligent systems having robust and feasible model with a number of integrated functionalities is the demand of future in every field of technology, for the betterment of the society. Earlier efforts include the work of Jagannathan Kanniah, who developed an obstacle avoidance mobile robot [1] with an inevitable accent towards the game version. Tung Y. Lin, who worked on the development of The Development of Intelligent Home Security Robot [4] by using GPS module as well as RF module. Yun Chan Cho, who worked on developing a Remote Robot Control System based on DTMF of Mobile Phone [3] using CDMA external module, for varying the speed of the robotic vehicle. Yi Jincong developed the Intelligent Robot Obstacle Avoidance System Based on Fuzzy Control [2] that utilizes signals of the ultrasonic sensors to avoid obstacle and fuzzy theory with sensor signals is used to control the speed of the wheeled mobile robot and make it
move to target location. Sng Hong Lian developed an obstacle avoidance mobile robot [7] which is controlled by a Fuzzy logic controller which can also measure the distance and climb up the walls in which the Fuzzy logic concept was adopted. Dong-ying Ju worked on the development of Remote control and Monitors system [9] by using GPRS networking concept. Karthi Balasubramanium worked on developing a robot for object recognition and obstacle avoidance [8] using the concepts of image processing and SONAR technology.
Our work provides the advantages of robust control by a cell phone, through this we can make our rover communicate from any part of the world provided there must be network connection in cell phone. This robot has wider range as large as the coverage area of the service provider, as a result can also be used to reach the places where humans accessibility or reach is still a question such as small tunnels, weird places etc., also no interference with other controllers and up to twelve controls. So this system will be a powerful and flexible tool that will offer this service at any time, and from anywhere with the constraints of the technologies being applied. Possible target appliances include (but are not limited to) climate control systems, security systems, and home appliances and anything with an electrical interface. Conventionally, wireless-controlled robots use RF circuits, which have the drawbacks of limited working range, limited frequency range and limited control. Use of a mobile phone for robotic control can overcome these limitations.
In this manuscript, we are controlling this rover through a wireless communication system using DTMF technology, GSM technology and night vision wireless camera. As the system is supplied with 5V, the Night vision camera will switch ON and it will transmit the images and videos to the receiver unit and the receiver unit will display the image/ videos to the connected display device (monitor/TV). As the call is made to the robot, the user is required to enter a correct password to proceed further. Password protection is required so that no one can misuse the functioning of this robot. According to the button pressed on the transmitting phone, the rover will move. But if any obstacle is sensed by the robot, it will change its direction (turn right in our case). This is also an intelligent system which includes gas sensor, smoke sensor and metal sensor for the security purposes in homes. The main
aim of using these sensors is to monitor smoke, gas leakage in houses as well as industries.
II. OVERVIEWOFTHETECHNOLOGYUSED
A. DTMF Description
DTMF stands for dual tone multiple frequencies. DTMF generation is a composite audio signal of two tones between the frequency of 697Hz and 1633Hz [6]. Its coding definition can be expressed as:
f(t)=A _{ a }sin(2C{ a}t)+A _{b }sin(2C{b }t) (1) In the formula (1), the two terms separately express the Values of low and high voice frequency. Aa and Ab
respectively indicate the sample quantization baseline of tone cluster of low voice frequency and high voice frequency, and the ratio of their amplitude is:
K=Ab/Aa (0.7<K<0.9) ( 2) The DTMF keypad is arranged such that each row will have its own unique tone frequency and also each column will have its own unique tone. Below is a representation of the typical DTMF keypad and the associated row/column frequencies. When any of the key like "1", "2", "*", "#" etc is pressed particular code is transmitted. This code is consist of two frequency among which one is higher frequency and second one is lower frequency(see Fig 1).
Fig. 1 DTMF Keypad Layout
When any DTMF code has been received at mobile phone it can be audible through speaker. So to decode this DTMF code speaker output itself can be used. Output of speaker is connected to IC MT8870 which is DTMF decoder IC. It used widely to decode DTMF code. It gives 4-bit digital output Q1; Q2, Q3, and Q4 according to the received key (see Fig. 2).
Fig. 2 The equivalent digital output for each key.
An MT8870 series DTMF decoder is used here. All types of the MT8870 series use digital counting techniques to detect and decode all the 16 DTMF tone pairs into a 4-bit code output. The built-in dial tone rejection circuit eliminates the need for pre-filtering. When the input signal given at pin 2 (IN) in single-ended input configuration is recognized to be effective(see Fig. 3), the correct 4-bit decode signal of the DTMF tone is transferred to D1 (pin 11) through D4 (pin 14) outputs D0 through D3 outputs of the DTMF decoder are connected to port pins of Microcontroller.
Fig. 3 Connection Diagram for MT8870
B. MATLAB code for DTMF Time Domain Graph
Code for plotting the Time Domain graph of the DTMF frequencies when various symbols are pressed respectively is coded below which is simulated in MATLAB 2012.
Fs = 8000; % Sampling frequency 8 kHz N = 800; % Tones of 100 ms t = (0:N-1)/Fs; % 800 samples at Fs pit = 2*pi*t; tones = zeros(N,size(f,2)); for toneChoice=1:12, % Generate tone tones(:,toneChoice) = sum(sin(f(:,toneChoice)*pit))'; % Plot tone subplot(4,3,toneChoice),plot(t*1e3,tones(:,toneChoice));
title(['Symbol "', symbol{toneChoice},'":
[',num2str(f(1,toneChoice)),',',num2str(f(2,toneChoice)),']']) set(gca, 'XLim', [0 25]);
ylabel('Amplitude');
if toneChoice>9, xlabel('Time (ms)'); end end
The corresponding Time- Domain graph for each symbol is shown in fig 4.
Fig. 4 Time domain analysis of DTMF frequencies
III.PROPOSEDARCHITECTURE
A. Block Diagram and description
Microcontroller 89S52 is the heart of this vehicular system which is interfaced with various sensor units as well as GSM module, DTMF Decoder and a motor drive to drive the motors of the robot. When the power supply of 5V is supplied to the system and as soon as the user will call on the cell phone attached with the vehicle through an earphone, the caller will receive a text message to enter a password. When the correct password is inserted, the robot will follow the commands as the user enters on the keyboard such as ‘2’ for moving forward, ‘4’ for turning left, ‘6’ for turning right, ‘8’ for moving backwards and ‘5’ to stop the movement. IR Sensor is connected to the “INT1” pin, Smoke sensor is connected to “INT1” pin, Gas sensor is connected to “TIMER0” pin and Edge detector is connected to the”TIMER1” pin of 89S52 Microcontroller. Now suppose for an instance, The robot is moving forward and it senses an obstacle in front of it, it will immediately stop there, turn right and move or suppose it senses any Smoke/Gas in the room or place, Interrupt is generated and as the interrupt is generated the microcontroller will send a text message to the user that “GAS/ SMOKE is sensed”.
Fig. 5 Block Diagram
This is how this robot works. We have drawn this Block Diagram (Fig. 5) and this process Flowchart (Fig. 6) using Microsoft Visio software.
Fig. 7 Trial Model
B. Power supply
Fig. 8 Power Supply 5V
For the power supply to the whole system, we have used a regulator called voltage regulator 7805 which converts the higher voltage to 5 V (Fig. 8) which is the desired supply to operate microcontroller and the modules. For the voltage supply of DC motors, we have used 7812 voltage regulator IC to get 12V for running the motors (Fig. 9).
Fig. 9 Power Supply 12V
C. Motor Driver
Robot Chasis is the major platform of the Robot Vehicle, which is connected with a mobile using DTMF circuitry. A cell phone is connected to the vehicle through a 3.5mm audio jack (as shown in fig. 6), receives call from the calling subscriber. According to the generated DTMF frequencies from the cell phone, the caller can control the robotic movement. IC L293D is designed in such a way to control two geared DC motors which takes command from the DTMF decoder through a Microcontroller. H-Bridge circuit is as shown in fig.10 below.
Fig. 10 H-bridge circuit.
D. Edge Detection unit
Edge Avoider Robot (EAR) is a mobile device, which senses and avoids the absence of surface below it. This simple concept was designed in order to help our robot to protect from falling. The circuit is shown below Fig. 11.
Fig. 11 Edge detection circuit
E. Smoke Sensor unit
The smoke detector is homebuilt using an IR emitter and detector. The voltage from the detector adjusts according to the amount of light being detected. This voltage is then compared to a reference voltage, high when the detector voltage is higher than the reference and low otherwise. The IR detector has a voltage output that reflects how much light it detects, around 2V with no obstructions and closer to 0V as less and less light is detected. Using this, the idea is to compare the voltage of the detector to a reference voltage that is calibrated such that if any of the light is obstructed from the detector, the voltage will drop below the reference voltage and the signal will go low. This low signal is then connected to INT0 on port3, thus allowing the smoke detector to externally interrupt the 89S52 and wake it up from sleep mode. Below is a circuit diagram of the smoke detector.
Fig. 12 Smoke Sensor
F. Gas Sensor unit
MQ135 has different resistance values at different temperature and different concentration of gases. The manufacturer recommends to calibrate the sensor at 100ppm of ammonia or 50ppm of alcohol. The recommended value of the load resistor is between 10K to 47K. The output is connected to the Timer0 of the microcontroller (Fig. 13).
Fig. 13 Gas Sensor
G. GSM based SMS interfacing unit
In this unit, we have interfaced a GSM module with Microcontroller with programming in such a way so that it will send a SMS to the caller. In this scheme RTS and CTS signals of serial port interface of GSM Modem are connected with each other. Text message may be sent through the modem by interfacing only three signals of the serial interface of modem with microcontroller i.e., TxD, RxD and GND. The transmit signal of serial port of microcontroller is connected with transmit signal (TxD) of the serial interface of GSM Modem while receive signal of microcontroller serial port is connected with receive signal (RxD) of serial interface of GSM Modem.
Fig. 14 GSM Module
IV.SOFTWARE
A. Calculation of Register values
Fig. 14 TMOD Register
For this System, we have given a time delay of 100µSec and using both the TIMERS so the value of TMOD register in Hexadecimal will be 0x66. TMOD (see fig. 14) is not a bit addressable register. So for the calculation of TH1, TL1, TH0 and TL0 bits value, we have used the TMOD register in Mode 2 i.e. Auto-reload mode. In this mode, only the lower byte (TLx) is used for counting. Upper byte (THx) holds the value to reload into TLx after an overflow. TFx must be manually cleared. Maximum count is 256. Maximum interval is 256 Microseconds or .256 milliseconds. Delay value (in HEXADECIMAL) can be calculated using the following formula:
[(255-x) +1]*1µSec= Delay duration (µSec) Where, x = THx OR TLx
Here, we want the delay of 100µSec, so according to above formula; [(255-x) +1]*1µSec= 100µSec (255-x) +1= 100 255-x=99 x= 255-99 x=156
Now in Hexadecimal 156 is equal to 9C. So value of TH0=TL0=TH1=TL1=0x9C.
B. Code:
The below is the software code for this rover. We have simulated this code in µVision4 software as shown in Fig. 10. #include<reg52.h> #include<stdio.h> #include<stdlib.h> #define step p1 void initialize_GSM_modem(void); void initialize_serialcommunication(void); unsigned char Command_CMGF[]="AT+CMGF=1\r"; unsigned char CtrlZ=0x1A;
unsigned char Command_CMGS[]="AT+CMGS
=+xx-xxxxxxxxxx\r";
unsigned char Command_AT[]="AT\r"; void delay();
void delay1(); void stepper(); void Main() {
unsigned char key1,key2,key3,key4; key1=key2=key3=key4=0xfa;
P1=0xff; P2=0x00; while(1) { here :if(P1==0xfb) { delay(); if(P1==key1) { if(P1==key2) { if(P1==key3) { if(P1==key4) { P2=0x10; while(1) { if(P1==0xf2) { P2=0x1a; } else if(P1==0xf4) { P2=0x18; } else if(P1==0xf6) { P2=0x12; } else if(P1==0xf8) { P2=0x15; } else if(P1==0xf5) { P2=0x10; } else if(P1==0xfc) { P2=0x20; goto here ; } } } } } } } else if(P1==0xfa) { P2=0x40; delay(); key1=P1; delay(); key2=P1; delay(); key3=P1; delay(); key4=P1; delay(); } else { P2=0x10; } } } void delay() { unsigned char i; for(i=0;i<10000;i++) { } } void initialize_GSM_modem(void){ delay(); puts(Command_AT); delay(); puts(Command_CMGF); delay(); puts(Command_CMGS); delay(); puts(msg02); delay();
while(!TI); TI = 0;SBUF = 0x1A; } void initialize_serialcommunication(void){ TMOD = 0x66; SCON = 0x50; TH1=TH0 = 0xB0; TL1=TL0 = 0xB0; TR1 = 1; TI = 1; }
void smoke() interrupt0 {
unsigned char msg[]="\n SMOKE IS SENSED\r"; IE0=0;
P2=0X20; delay(); initialize_GSM_modem(void); initialize_serialcommunication(void); delay(); IE0=1 goto again; }
void gas() interrupt1 {
unsigned char msg[]="\n GAS IS SENSED\r"; IE1=0; P2=0X20; delay(); initialize_GSM_modem(void); initialize_serialcommunication(void); delay(); IE1=1; goto again; }
void obstacle() interrupt2 { IE2=0; P2=0X20; delay(); p2=0x29; delay(); IE2=1; p2=0x1A; goto again; }
void metal() interrupt3 { IE3=0; P2=0X20; delay(); p2=0x29; delay(); IE2=1; p2=0x1A; goto again; } void stepper() { while(1){ step = 0x0C; delay(); step = 0x06; delay(); step = 0x03; delay(); step = 0x09; delay(); } } void delay1() {
unsigned char i,j,k; for(i=0;i<6;i++) for(j=0;j<255;j++)
for(k=0;k<255;k++); }
Fig. 15 Simulation of Code in µVision4 software
V. APPLICATIONSANDFUTURESCOPE
A. Military use
Military usage of remotely controlled military vehicles dates back the first half of 20th century. This can be a great asset to save lives of both people along with soldiers in case of terrorist attacks like the one happened in 26 Nov, 2008 in Mumbai, India. Unmanned Aerial Vehicles (UAVs) will likely play an increased role in search and rescue in the United States. Slowly other European countries (even some developing nations) are thinking about making use of these vehicles in case of natural calamities & emergencies.
B. Alarm Phone Dialers
By replacing DTMF Decoder IC CM8870 by a 'DTMF Transceiver IC CM8880, DTMF tones can be generated from the robot. So, a project called 'Alarm Phone Dialer can be built which will generate necessary alarms for something that is desired to be monitored (usually by triggering a relay). For example, a high water alarm, low temperature alarm, opening of back window, garage door, etc.
C. Pick and Place Arm
This robot can be modified by attaching a robotic arm which will pick and place the robot in the back carrier box [5]. In process of picking an object, one arm will be constant and other arm will move. This other arm grasps the object and picks it up. For this purpose motor of 100r.p.m, 30r.p.m will be use to control and move arm and it will work according to instruction it got from microcontroller through GSM (by operator). If yes then the arm will move 180 degree upwards and keep the object in carrier box. And this takes place with help of motor will move the robotic arm through a rod this all control and instruction are all under Microcontroller.
CONCLUSION
By developing this robotic vehicle with its multi-tasking feature, We have overcome the drawbacks of RF communication which have a limited range as this car can be controlled from anywhere in the world just using this DTMF technology. The main advantage of this robot is that it is password protected with wireless night vision so that any other person cannot communicate with the robot and it can see the objects in the night also. It has various sensors which will function accordingly to the software coded and send SMS to the user accordingly. The wireless camera will record the image and send it to the receiver unit which will display the image/videos on the monitor/TV. Considering all the situations, the robot integrated with different sub modules can be used for redemption and security purpose.
REFERENCES
[1] Kanniah Jagannathan, “Control of an obstacle avoidance robot”, Motion Control Proceedings, 1993, Asia-Pacific Workshop on Advances in 15-16 Jul 1993.
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[3] Yun Chan Cho, “Remote robot control system based on DTMF of mobile phone”, Industrial Informatics, 2008. INDIN 2008. 6th IEEE International Conference on 13-16 July 2008 at Daejeon.
[4] Tung Y. Lin, “The development of intelligent home security robot”, Mechatronics, 2005. ICM '05. IEEE International Conference on 10-12 July 2005 at Taipei.
[5] Manish Kumar, “Design of Cell Phone Operated Robot Using DTMF for Object Research”, IEEE Wireless and Optical Communications Networks (WOCN), 2013 Tenth International Conference on 26-28 July 2013.
[6] Wei Song, “A wireless access control system based on CDMA and DTMF technologies”, IEEE Computer Science and Network Technology (ICCSNT), 2011 International Conference on (Volume:2 ).
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[8] Balasubramanian, K., “Object recognition and obstacle avoidance robot”, IEEE 17-19 June 2009 Chinese Control and Decision Conference (CCDC 2009).
[9] Dong-ying Ju, “Development of Remote Control and Monitor System for Autonomous Mobile Robot Based on Virtual Cell Phone”, IEEE 5-7 September 2007 Innovating Computing, Information and Control, 2007. ICICIC’07. Second International Conference.
