Design and Development of A GSM Controlled Unmanned Ground Surveillance Vehicle (v1.0)

Transcription

1 I J C E E Volume 4 Number 1 January-June 2012 ISSN : ; pp Design and Development of A GSM Controlled Unmanned Ground Surveillance Vehicle (v1.0) Acharya Chintan M. and Ved Vyas Dwivedi Noble Group of Institutions-Junagadh, Gujarat, India Abstract: A remote controlled vehicle is defined as any mobile device that is controlled by a means that does not restrict its motion with an origin external to the device. Generally the mode of control is by using Radio Frequency range which has the disadvantage of limited range. So in this paper we have made the control range of our remotely controlled vehicles (RCVs) virtually infinite by employment of GSM (Global System for Mobile Communication) as the mode of controlling our RCV. The authors studied, investigated, analyzed, designed, developed, and tested the proposed GSM controlled unmanned ground vehicle (GCUGV) and measured the output responses and produced the same here. The programme codes were also developed by the authors and after installation of the programme code the results were satisfactorily recorded. This propeller-driven radio controlled boat, built by Nikola Tesla (10 July January 1943) in 1898, is the original prototype of all modern-day uninhabited aerial vehicles and precision guided weapons. Once in a position, a command would be sent to detonate an explosive charge contained within the boat s forward compartment. The weapon s guidance system incorporated a secure communication link between the pilot controller and the surface running torpedo In an effort to assure that the control could be maintained even in the presence of electronic countermeasures. [1] During World War II in the European Theatre the U.S. Air Force experimented with three basic forms radio- control guided weapons. In each case, the weapon would be directed to its target by a crew member on a control plane. The first weapon was essentially a standard bomb fitted with steering controls. The next evolution involved the fitting of a bomb to a glider airframe, one version, the GB-4 having a TV camera to assist the controller with targeting. It is known that Germany deployed a number of more advanced guided strike weapons that saw combat before either the V-1 or V-2. They were the radio controlled corresponding s: director.principal.ngi@gmail.com, acharyachintan1@gmail.com

2 Herschel s Hs 293A and Ruhrastahl s SD1400X known as Fritz X both air-launched, primarily against ships at sea. [1] The discussed GSM controlled UGV has various applications in different fields of defence sector. The advantages and disadvantages/limitations of the discussed GSM controlled UGV has also been explored in this section. Scientific applications can be studied in terms of RCVs which have various usages including hazardous environments, working in the Deep Ocean, and space exploration. The majority of the probes to the other planets in our solar system have been remote control vehicles, although some of the more recent ones were partially autonomous. [2] Military usage of remotely controlled military vehicles dates back to the first half of 20th century. Soviet Red Army used remotely controlled Teletanks during 1930s in the Winter War and early stage of World War. Remote controlled vehicles are used by many police department bomb-squads to defuse or detonate explosives. Unmanned Aerial Vehicles (UAVs) can hover around possible targets until they are identified before releasing their payload of weaponry. Back pack size UAVs will provide ground troops with over the horizon surveillance capabilities. [2] UAVs will likely play an increased role in search and rescue in the United States. This was demonstrated by the successful use of UAVs during the 2008 hurricanes that struck Louisiana and Texas. [2] These vehicles are advantageous to common human beings for their routine toprofessional compatibility such as: Wireless robust control, Surveillance system, Vehicle navigation with use of 2G technology, and their uses for mobile wireless network that make range virtually infinite. On the other side certain insignificant disadvantages have been observed such as: Version v1.0 of this project can only be operated in a Line-Of Sight kind of operations. Suitable for tasks having 1 to 2 hrs of timing limits as cell phone batteries drain out faster. Costing increases if mobile phone cost is included. Section II of this paper represents Methodology used to design and develop the GSM Controlled UGV. Section III represents Components, Tools & software used for the proposed UGV. Development of programme code or software used for the operation of this UGV has been discussed in section IV while section V represents development of hardware for the proposed GSM Controlled UGV while Section VI produces the laboratory test results and analysis of the experiment outputs conducted to test the proposed UGV and consequently in section 7 the future perspectives of this project have been highlighted.

3 Dual-tone multiple-frequency signalling (DTMF) is used for telecommunication signalling over analogue telephone lines in the voice-frequency band between telephone handsets and other communications devices and the switching centre [3]. The version of DTMF that is used in push-button telephones for tone dialling is known as Touch-Tone. It was developed by Western Electric and first used by the Bell System in commerce, using that name as a registered trademark. DTMF is standardized by ITU-T Recommendation Q.23. It is also known in the UK as MF4. Other multi-frequency systems are used for internal signalling within the telephone network. The Touch-Tone system, using the telephone keypad, gradually replaced the use of rotary dial starting in 1963 and since then DTMF or Touch-Tone became the industry standard for both cell phones and landline service. Table 1 shows the DTMF frequencies produced when a particular key is pressed on the telephone keypad. [3] Table 1 [3] Dtmf Frequencies 1209 Hz 1336 Hz 1477 Hz 1633 Hz 697 Hz A 770 Hz B 852 Hz C 941 Hz * 0 # D As shown in figure 1 (block diagram), the first block is the cell phone. So, it acts as a DTMF generator with tone depending on the key pressed. DTMF decoder IC M8870D decodes the received tone & gives binary output equivalent to the microcontroller. The microcontroller is programmed such that appropriate output is given to it. The concept used for driving is Differential Drive. So ultimately the 2 motors rotate according to the key pressed on the keyboard of the cell phone. Various components, tools, and software were utilized for the designing and development of this GSM controlled UGV. The list of the hardware components, devices, and other miscellaneous tools has been tabularized in Table 3. The important components of this robot are a DTMF decoder, microcontroller and motor driver. A CM8870 series DTMF decoder is used here. All types of the CM8870 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 of pre-filtering.

4 Figure 1: Block Diagram of the GSM Controlled UGV Figure 2: A Snap of Discrete Components used to Develope this UGV When the input signals are given at pins 1(IN+) & 2(IN-), a differential input configuration is recognized to be effective, the correct 4-bit decode signal of the DTMF tone is transferred to (pin11) through (pin14) outputs. The pin11 to pin14 of DTMF decoder are connected to the pins of microcontroller (P1.4 to P1.7). The atmega16 is a 8-bit microcontroller, has 64 KB Flash microcontroller

5 with 1 kilobyte RAM. It provides the following features: 64 kilobyte of on-chip Flash program memory with ISP (In-System Programming) and IAP (In-Application Programming), Four 8-bit I/O ports with three high-current. Port 1 pins (16 ma each), Three 16-bit timers/ counters. Outputs from port pins P0.0 through P0.3 and P0.7 of the microcontroller are fed to the inputs IN1 through IN4 and enable pins (EN1 and EN2) of motor driver L293D IC, respectively to drive two geared dc motors. Switch S1 is used for manual reset. The microcontroller output is not sufficient to drive the dc motors, so current drivers are required for motor rotation. The L293D is a quad, high-current, half-h driver designed to provide bidirectional drive currents of up to 600mA at voltages from 4.5V to 36V. It makes it easier to drive the dc motors. The L293D consists of four drivers. Pins IN1 through IN4 and OUT1 through OUT4 are the input and output pins, respectively of driver 1 through driver 4. Drivers 1 and 2, and driver 3 and 4 are enabled by enable pin 1(EN1) and pin 9 (EN2), respectively. When enable input EN1 (pin1) is high, drivers 1 and 2 are enabled and the outputs corresponding to their inputs are active. Similarly, enable input EN2 (pin9) enables drivers 3 and 4. The motors are rotated according to the status of IN1 to IN4 pins of L293D which in turn are depending on output pins of microcontroller, viz., P0.0 - P0.3. Figure 3 shows the circuit schematics of the GSM Controlled UGV. Figure 3: Modified Circuit Schematics of the GSM Controlled UGV

6 The software used for circuit designing, PCB layout designing and to write the programme code are as listed below: 1. Eagle PCB Designing Tools. 2. C Language for the Programming of ATMega AVR Studio for Burning the Programme in ATMega16 microcontroller 4.1. We must now discuss the software that supports all the operating functions while the UGV is in motion. So to create a programme code for the UGV first we design the flow chart of the functions we require to perform by the combination of the hardware and software both. The programme flow chart is as shown in the figure 4. [4] [5]. The programme code designed for the proposed GSM Controlled UGV is as demonstrated below in a modified form. The code given here is not in its original form and the key points of the code have been retained with the authors because of future expansion and limitations. FILENAME: UGV_CODE.C Source program: #include <stdio.h> Void main (void) Unsigned int k, h; DDRD=0X00; While (1) k =~PINA; h=k & 0x0A; Switch (h) case 0x02: //if I/P is 0x02 PORTD=0x69;//O/P 0x89 i.e. Forward break; } case 0x08: //if I/P is 0x08

7 PORTD=0x76; //O/P 0x86 i.e. Backward break; } case 0x04: //o/p is 0 04 i.e. left turn PORTD=0x55; // Left turn break; case 0x06://o/p is 0 06 i.e. right turn PORTD=0x8C; // Right turn break; case 0x05: PORTD=0x0; // Stop break; } } The PCB layout was made using the Eagle PCB Designing software. The layout prepared was then fabricated using the conventional methods for PCB fabrication. The PCB layout is shown in figure 4. The manufactured PCB from the designed layout is shown in figure 5. [8] Figure 4: PCB Layout Design of the GSM Controlled UGV

8 Figure 6 shows the finally designed, developed, tested, and analyzed completed hardware of the proposed GSM Controlled UGV. Figure 5: Manufactured PCB Figure 6: GSM Controlled UGV (v1.0) Finally Developed, Tested & Analyzed

9 Figure 7: Flow Chart of the Programme Code The laboratory tests and experiments performed during and after the design and development of the proposed GSM controlled UGV under various experimental conditions are as recorded in Table 3.

10 Table 4 Laboratory Test Results Distance of Geographical Hindrances: Response time: Accuracy: measurement terrain: Case 1: 1m-300m. Plain, concrete Cars, stone walls, ~ 1sec. Satisfactory. tiled surface. concrete pillars, people. Case 2: 1m-300m. Unlevelled rough Trees, bushes, ~1sec. Satisfactory. play ground. people. Table 3 List of All Hardware Components & Devices Sr no. Name of Electrical Mechanical Quantity Make/number. component/device. specifications specifications (cm) 1. MT8870 DTMF Vdd=5v, MT8870DE/1032DSB Decoder Ic XTal=3.57Mhz±0.1% 2. AtMega16 8-bit Vdd=5v, Microcontroller Xtal=12Mhz,512K ATMEGA16A/PU1041 byte EEPROM,1K byte SRAM LS Hex Vdd=5v HD74LS04P Inverting gates Ic 4. LM293D Motor Vdd=4.5v to 36v, AALZRM/L293DNE Driver Ic Io= ~ 600mA 5. Xtal-1 12Mhz crystal f = 12Mhz /KDS Xtal Mhz f = 3.57Mhz KDS crystal. 7. Aluminium Chassis DC Geared Motor V input=6v Dc L=4.6, 2 MT200 diameter=2.5, 300rpm 9. Polymer Wheels Radius=3.5cm AA battery pack V per cell=1.5v, V output= 9v 11. Cell phone. 2nd generation (2G) network enabled cell phone, Nokia 1208 f = GSM 900/1800 band All the observations achieved by performing different tests and experiments on the proposed GSM Controlled UGV have given satisfactory results and functioning of the UGV has been nearly accurate as per the commands given during the conduction of experiments.

11 Although the concept & design of the project seemed perfect, there were some problems faced while actual implementation: There were several types of Hands Free cords available in the market, the right one had to be chosen from them. Several ways to break up the cords and connect them to the input of IC 8870 were tried & some were newly developed by us (e.g. Connecting Audio Jack of PCs speakers to the cell Phone with help of an extender). Finally the ear plugs were removed and the resulting set of wires were connected in an appropriate manner to the decoder IC s input. At first, latest cell phone like Nokia 5700, N-series were tried. But they couldn t give any output. Several cell phones were tested with their respective Hans free cords. Then the older versions of cell phones were used Like Nokia 1208, Nokia 1100, etc. After performing, observing, and analyzing the test results that were obtained as an outcome of various experiments conducted in different surrounding conditions the authors have concluded that the proposed GSM Controlled UGV has performed very satisfactorily fulfilling the task sets designed to test its accuracy. The proposed UGV has several future aspects which could be experimented and developed in the upcoming versions of this UGV. IR sensors can be used to automatically detect & avoid obstacles if the robot goes beyond line of sight. This avoids damage to the vehicle if we are manoeuvring it from a distant place. Project can be modified in order to password protect the robot so that it can be operated only if correct password is entered. Either cell phone should be password protected or necessary modification should be made in the assembly language code. This introduces conditioned access & increases security to a great extent. An alarm phone dialler 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. When the system is activated it will call a number of programmed numbers to let the user know the alarm has been activated. This would be great to get alerts of alarm conditions from home when user is at work.

12 If the current project is interfaced with a camera (e.g. a Webcam) robot can be driven beyond line-of-sight & range becomes practically unlimited as GSM networks have a very large range. The authors would like to thank Mr. Sandeep Jani (of Sandeep Electronics, Rajkot) for providing all the components and miscellaneous spares for this project, Mr. Kirit Bhalsod of Noble Engineering College for providing the facility to burn the programme code into the microcontroller, and Mrs. Megha Mehta, Head, Department of Electronics and Communication, and NGI campus for providing laboratory facilities to us. [1] [2] [3] [4] Embedded C Programming and the Atmel AVR, Richard H. Barnett, Larry O Cull, Sarah Cox. [5] Atmel AVR Microcontroller Primer: Programming and Interfacing, Steven F. Barrett, Daniel J. Pack. [6] DTMF Tester, Electronics For You Magazine, Edition (June 2003).h [7] [8] [9] Global System for Mobile Communication (GSM), Li-Hsing Yen, Assistant Prof. Dept. of CSIE, Chung Hua Univ.