Mongol Barota : A Next Generation Rover Md. Kishwar Shafin1 , Kazi Lutful Kabir2 , Iffatur Ridwan3 , Tanvir Ahmed Fuad4 , Sharmistha Bardhan5 , Md Ismail Hossain Raju6 , Afifa Tahira7 , Ibtasham Afrin8 , Sushmita Mondal9 , Sanjida Nasreen Tumpa10 , Ashfaque Ahmed11 , Minhajul Arifin Badhon12 , Muhammad Tanvirul Islam Jony13 , Fahim Hasan Khan14 , Md Mahboob Karim15 and Md. Afzal Hossain16 Department of Computer Science and Engineering, Military Institute of Science and Technology, Mirpur Cantonment, Dhaka, Bangladesh. Email: [email protected] , [email protected] , [email protected] , [email protected] , [email protected] , [email protected] , [email protected] , [email protected] , [email protected] , [email protected] , aap [email protected] , arifin [email protected] , [email protected] , fhk [email protected] , [email protected] , [email protected] .

Abstract—This paper scrutinizes Mongol Barota - a fully functional, stand-alone mobile platform rover which is capable to act as a human assistant to perform various scientific tasks in extreme adversities. The control system of the rover is designed in such a way that it can be commanded from a blind station within 1 kilometer range. It has successfully taken part in 8th annual University Rover Challenge organized by the Mars Society at the Mars Desert Research Station (MDRS) in the remote, barren desert of southern Utah, USA in late May, 2014. It has been traced out as the first entrance in this competition from Bangladesh and occupied 12th position out of 31 registered teams from 6 countries of 4 continents. The rover architecture maps the associated components to make it capable to perform the assigned tasks namely - Sample Return Task, Astronaut Assistance Task, Equipment Servicing Task and Terrain Traversing Task. Among these, the first task refers to search for the evidence to identify the existence of life after detailed analysis of collected soil sample from a selected site. In Equipment servicing task, rover has to perform a sequence of operations that mainly includes switching on a compressor and working with a series of pipes, hoses, valves and other such equipment. Astronaut assistance task intends the rover to collect tools from some given GPS locations and then delivery of each of them to the corresponding locations with provided GPS coordinates. Rover has to traverse an adverse terrain in order to pass through a set of target gates for completion of the terrain traversing task. This paper provides a detailed demonstration of the Mongol Barota rover, ins and outs of its architecture, facts and features, system components, logic, logistics and techniques adopted to implement several tasks representing its overall capabilities. Index Terms—Blind Station, Equipment Servicing, GPS Coordinate, Human assistant, Soil sample.

I. I NTRODUCTION In the current era, robotics and mechatronics is considered to be one of the most optimistic interdisciplinary engineering fields of research, particularly in the arena of automation. Robotics is the scientific and technological wing that handles the architecture, manufacture and implementation of intuitive machines along with the computer software and systems that empower their intuition. Mechatronics is the consolidation of mechanical, computer as well as electronic engineering in the design of integrated systems with high capabilities that accommodate numerous intelligent traits [1]. In fact, implementation of modern systems and control methods to real life situations are continuously being dealt with robotics and mechatronics. Dramatic advances in these sectors have immediately enabled new applications and integration in many c 978-1-4799-6399-7/14/$31.00 ⃝2014 IEEE

research areas from defense to service applications. Space exploration is another sector where robotics has already made valuable contributions. However, every surface in the solar system is vulnerable for humans due to air composition, temperature, radiation complexity, lack of gravity and so on. On the other hand, robots have much less restrictions and can withstand much more under these adverse circumstances. Undoubtedly, Mars exploration is not a new chapter in this particular zone. However, the University Rover Challenge (URC) is the world’s premier robotics competition that held annually in the desert of southern Utah, USA. URC challenges university students to design and build a next generation Mars rover covering one day of work alongside human explorer in the field [2]. With this competition in view, we have featured our rover Mongol Barota so that it can perform the assigned tasks efficiently. This stand-alone mobile platform rover is actually the outcome of integration of the component hardware modules and the supporting software (developed entirely by the Mongol Barota team members) against almost each of the hardware modules. The objective of this paper is to introduce Mongol Barota, to describe its architecture in brief, to demonstrate with the component hardware modules used, to provide the specifications and procedural details of the software to support the complete system along with its task performing capabilities. The remaining of the paper will be unfolded in the following sequence : Section II covers Related Works, Design Architecture and Rover Mechanics in Section III, Rover Electronics in Section IV, Section V describes Rover Communication System, Section VI holds Live Video Streaming System, description of Rover Software and Associated Hardware in section VII, Tasks and Features in section VIII, Section IX represents Observations and Experiments, Section X with Conclusion followed by Acknowledgment. II. R ELATED W ORKS Mars exploration is not a new topic in the area of space research. For instance, Wilcox and Gennery discussed about some technical concerns of a Mars rover that was launched in 1990 [3]. Ohm and Ivlev provided a brief overview of the entire system of Rocky 7 - a rover prototype, addressing all the aspects starting from hardware design to data acquisition and testing [4]. A newly introduced manipulation system particularly for sampling and equipment placement was described by Volpe and Ohm in a technical report [5]. Tarokh

TABLE I C OMPARISON OF M ONGOL BAROTA WITH THE ROVER OF YURT 2008-09 Criteria Wheels and suspension

YURT 4-wheel design with suspension in each leg

Motor Driver

commercially available motor drivers

GPS Data

GPS data was reported as a problem Software Integration of commercially available components Communication Separate Channel communication channel for camera and rover control

Mongol Barota 6-wheel architecture with suspension in front and rear legs (well-balanced control for rough terrain) Self-designed and developed motor driver (to handle high power required by the motors) Mean value of several GPS data is considered (to improve the accuracy) Self-developed software (to provide a greater degree of control over the entire system from a blind station) Single channel for camera and rover control ( to ensure simplicity of control mechanism)

and McDermott described a technique for kinematic modeling of Rocky 7 to ensure full six degrees of freedom [6]. Maurette put forward the details of autonomous navigation of a rover on the surface of Mars [7]. Curiosity rover of NASA landed on Mars on August 6, 2012 with driving capability of 20 kilometers with a view to explore habitability. The Mars Society launched URC in 2007 in order to contribute to this area of Mars exploration. At the very outset of University Rover Challenge 2014, as a part of preparation, we have studied the experience of York University Rover Team of 2008-09 [8] and Magma team [9]. YURT proposed a general trend toward design modularity, purpose-driven customizations and better critical thinking in the design process. Table I provides a brief comparison addressing some technical and technological concerns.

Fig. 2.

Rover Internal Architecture in Solidworks

The mainframe or the chassis of the rover is a (26 inches x20 inches x6 inches) box like structure containing a 3x2 steel criss-cross pattern to mitigate the possibility of shape distortion due to application of uneven pressure. When the rover rotates in right direction, the right wheels go backward and left wheels go forward. In this process, there is a chance of having uneven pressure in one side of rover’s body. To reduce this particular effect, the criss cross pattern is used so that rover chassis do not bend easily and the pressure is balanced evenly. Two shafts are used to support the mounting of legs on the rover. Shafts provides support to the legs of the rover and confirms that side by side alignment of the wheels are fine.

III. D ESIGN A RCHITECTURE AND ROVER M ECHANICS

Fig. 3. Fig. 1.

Mongol Barota : A Next Generation Rover

At the very outset of rover design, the consideration of rough terrain leads towards a six wheeled architecture where the frontier region has two wheels and that of rear has one hence overall three wheels per side. The chassis is designed to serve the purpose of mounting of electrical box, batteries, rover hand and other components. The full rover dimension is of 48 inches x 38 inches x 19 inches.

Design of Rover Chassis in Solidworks

The wheels are controlled by high RPM gear motors [10]. Two front wheels has a rotation degree with its attached suspension. When the front wheel tries to cross any obstacle then it uses the rotation degree to cross and the rear wheel provides necessary support. While plunging down, the front wheel will drop first provided by the rotation degree and the rear wheel will maintain the balance. The Rover arm has three parts: shoulder, elbow and wrist. The base of the arm can rotate up to 360◦ and possess a DC

Fig. 4.

Motion Range of Front Wheels Fig. 5.

gear motor to achieve this functionality. Basically, the rotation is defined by placing a jagged round base. There is a 12 inches stroke actuator [11] placed in the elbow and a 4 inches stroke actuator [12] placed in the wrist which gives the components a sophisticated movement. Two types of grip are required for the rover as it has to perform soil digging and grasping tools and equipment. The soil digger can be considered as a combination of SHOVEL and TROWEL which can dig soil very easily to collect soil sample. Top of the digger is jagged so that hard soil can be penetrated too. The grip has two fingers, which are favorable of holding pipes, handles etc. A 2.5 inches gap is retained between the fingers. Above all, the rover architecture and mechanics jointly yields such a balanced infrastructure that can withstand any hazardous situation having no impact on the structural aspects. IV. ROVER E LECTRONICS Figure 5 provides an overview of the entire electronics system of the rover including the power supply subsystem and it also covers power consumption by individual modules, motor drivers and actuators. At the eve of preparing its design, optimization of performance with rational power consumption and associated cost plus reliability of the power supply system have been prioritized. All the electronic equipment of the rover have been assigned to be powered by an on-board rechargeable power supply comprising of battery(actually two 24V-25A lithium-polymer batteries) and voltage regulator as its major components. To obtain constant voltage without disruption is the primary objective of using voltage regulator and ICs from 78XX families which are capable to convert DC-DC have been utilized to accomplish this objective. The input to the voltage regulator is within the range of 14V to 32 V. Capacitors have been used to cancel out any irregularities in the input voltage. Due to the intense heat generated by the 78XX series ICs, attachment of heat sinks to each IC and incorporation of a cooling fan have been considered into the design. A number of output voltages are extended from the regulator to power different standalone electronic modules. For Raspberry Pi, power is availed from the two USB ports. The +9V port power is dedicated for

Block Diagram of the Overall Electronics System of the Rover

communication, for Router and Switch in particular. The Video server, Servo controller, Auxiliary cameras and the Main IP camera are powered from the +12V docks. The switching relays are powered from +5V ports and the Arduinos are powered from the +12V ports but the sensors that we utilized did not require any external power as they are getting power from Arduinos pins. Each of the six gear motors requires +24V, each of the two actuators and three right-angled DC motors need +12V which have been managed directly from the battery source through motor drivers. In average, total current consumption is around 20 Ah in a rough terrain. The battery can flawlessly support the rover for 1 hour which is already tested under different circumstances. V. ROVER C OMMUNICATION S YSTEM Communication method follows the FCC standard and regulations. For communication between the rover and control station, a single access point along with an antenna is placed on both the rover and the control station. A 2.4GHz 150Mbps outdoor wireless access point [13] with frequency of 2.42.4835GHz is used in WISP Repeater Mode (in the tent side) and in Access Point Mode (in the rover side). A 2.4GHz 15dBi outdoor omnidirectional antenna [14] is used whose 15dBi omnidirectional operation effectively enlarges the wireless coverage. In order to communicate, the 802.11 b/g/n wireless distribution system has been implemented with all the network equipment. In addition to this, there is single transceiver for data transmission from rover side to control station side. Keeping the data transmission reliable, to ensure smooth controlling of the rover while developing software, some certain network protocols and design logic have been applied. An elaborate description of those are in section VI. VI. L IVE V IDEO S TREAMING S YSTEM This subsystem consists of one IP Camera, Four Auxiliary IR Cameras and one DVR. These five cameras are organized in way so that the scenario around the rover can be visible to the controller. These cameras are controlled in the easiest possible way to avoid data loss and other unwanted consequences. 1) Main Camera: The 3 Megapixel IP Network Box Security Camera [15] is used as the Main Camera. This ultra-high

along with a reliable network is the prime requirement of the rover control system - which is exclusively handled by the 700 MHz ARM11 processor and built-in 10/100 wired Ethernet of the Raspberry Pi. 512 MB RAM and the ‘Raspbian’ operating system running from an 8 GB SD card provides the user a friendly environment to communicate with the rover. The Raspberry Pi is persistent enough to withstand the high temperature and rough terrain and hence no external heat sink is needed. The rover controller is programmed in Python as it is the recommended language for Raspberry Pi. A widelyused single-board micro-controller Arduino [18] is used to get the data from accelerometer, GPS, temperature, humidity and other sensors. An Arduino compatible Ethernet shield is used to transmit the sensor data from the rover to the base station via a Wi-Fi router. Fig. 6.

Rover Communication System Architecture (Block Diagram)

resolution camera is used to stream 3 megapixel video at 15 fps, capture high resolution image of sites, wide angle panorama, etc. The smaller frame rate makes the data packet transmission easier and reduces pressure on the transmission lines. 2) Auxiliary Cameras: For the side view two 600 Line Indoor Micro Camera 30 Ft IR Range Cameras [16] are used. One in the left side and the other in the right side of the rover. Since the Main Camera is set at the front side of the rover, the back view can be found by the Back Camera. The Back Camera is also an IR Camera. 3) Arm Camera: One IR Camera is fixed at the claw of the arm. This camera mainly serves the purpose of seeing what the arm is intended to do. In some tasks such as, Equipment Servicing Task or Sample Return Task, it plays an important role. 4) DVR (Digital Video Recorder) : The four Auxiliary cameras are controlled using this DVR. Moreover the data packets sent by these cameras are also received by this. Since these cameras are not IP camera, DVR makes the data packet transmission and reception as like as an IP Camera. VII. ROVER S OFTWARE AND A SSOCIATED H ARDWARE The rover software (developed entirely by Mongol Barota team members) establish a central system to control the rover from a remote station and to represent the data obtained from sensors attached to the rover in human understandable format. In fact, each sensor is under a separate system according to individual task requirement. The software are developed using JAVA and Python programming language. The core integrated software is developed in JAVA, which offers a user-friendly GUI(Graphical User Interface) to communicate with the rover. Java Run time Environment (JRE) and Python-3.4.0 are the primary requirements to run the software. The rover software have been designed as the server side and the control station software as the client side which communicates with each other through wireless data transmission and thus implementing a complete client-server application. The software helps to interface with accelerometer, GPS receiver, Soil Humidity Sensor, Temperature and humidity (air) sensor. The rovercontrol is based on a single-board, Linux based mini computer - Raspberry Pi [17]. A fast, durable and consistent system

A. Rover Motion Controller The main motor driver of the rover is a ‘four-logic’ system, which is operated by a Raspberry Pi. Four pins of the Raspberry Pi are dedicated to render the control instructions to the motor driver. The combination of high and low logic, of these four pins defines the direction of the rover towards left, right, forward or backward. Rover Controlling System is divided into two parts, client program at Control station and server program at rover. At the rover, server program is run under Raspberry Pi operating system. Client-server communication follows UDP protocol. Iy gets instructions from control station and then changes the logic of the pins according to the instructions. On the other side, client program at control station is interfaced with keyboard and also has a very friendly graphical user interface. UP, DOWN, LEFT and RIGHT arrow keys of keyboard are representing forward, backward, left and right turn of the rover respectively. The information about the change in keys is send to the server for corresponding reflection on the rover. After every 0.5 second an acknowledgment is sent to the rover for indicating that client is still connected with the server. If no acknowledgment is received by the rover in 1 or 2 second(s), it is considered as a network problem and all pins of Raspberry Pi are set to low preventing the rover from being in uncontrolled state. B. Rover Arm Motion Controller The arm motion controller of the rover is designed and developed in Python for both client and server side. The network protocol as well as the motor driver design is identical as the rover motion controller. The program at server side runs on the Raspberry Pi, and the client side runs at control station where it gets instructions from keyboard interface. Total seven values can be taken from the keyboard as instruction. The RIGHT and LEFT arrow keys are dedicated for Arm Base movement. The UP and DOWN arrow keys are used for the other motors, while the motors can be chosen using A, S, D and F keys. For example, the elbow motor can be chosen using S key and can be moved upward and downward using UP and DOWN arrow keys respectively. C. Accelerometer Supporting Software The software to support accelerometer is designed to provide the exact orientation of the rover at any instance that helps to understand from blind control station whether the rover is in tilted position or not and also the amount of

tilting (when applicable)-Figure 7. An MPU-6050 sensor [19] is used which is a single chip package containing a 3 axis accelerometer and a 3 axis gyroscope. It is very accurate, since it contains 16-bits analog to digital conversion hardware for each channel. Therefore it captures the x, y and z channel at the same time. It works extremely fine with 5V and 3.3V micro-controllers without any adversities. MPU-5060 board is connected with Arduino UNO and Arduino Ethernet Shield at rover side. This board is communicating with Arduino UNO using standard I2C bus. Accelerometer and gyroscope cannot provide accurate orientation independently as they possess systematic errors. But their combined use causes errors to be canceled out. ‘Complementary Filter’ has been used to accumulate them. This filtered angle and board temperature are sent to the control station. Rover only sends data when permitted by the Control station.

the variation of the moisture level without any calculation. Arduino serves as the server for this program. The moisture chart and the moisture log can be printed at any instance which helps the user in data tracking. E. Software to represent Temperature and Air Humidity For prediction of weather and environment, the rover has been built with the capability of sensing temperature and humidity of the air. A DHT11 sensor [21] is used in order to accomplish this goal. It is a digital sensor that uses capacitive humidity sensor and a thermistor to measure the humidity and temperature. The fast-response time, simplicity, accuracy and small size of DHT11 is just perfect to meet the requirements. The sensor takes reading after getting a ‘read’ signal from the client and transmits the data over the network using UDP protocol.

Fig. 8. Software Interface that takes Readings of Temperature and Humidity

Fig. 7. Tilted Position of Rover Projected in Accelerometer supporting Software

Control Station starts receiving the accelerometer data after connecting with the rover. To visualize the rover orientation on the surface from control station, rover angle on the surface at X and Y axis are used to orient a green box (Figure 7). That means, the orientation of the box reflects corresponding change of rover orientation on the surface. The temperature of the accelerometer board is also shown with rover orientation.

The client side software is developed in JAVA that interprets the temperature and humidity reading into a meter. The meter reading is dynamically updated on every second and the readings are recorded on a live log providing a clear view of the current rover environment. F. GPS Plotter

D. Soil Moisture Sensor Software To collect soil sample, site selection is done by examining the moisture of the soil by means of a soil humidity sensor [20]. A threshold adjustment potentiometer is used for soil moisture where clockwise adjustment is required. Digital outputs (D0) can be directly connected to the micro-controller by single-chip computer to detect high or low level, thus detecting soil moisture. Analog output (A0) for the sensor values have been used to ensure preciseness. This sensor can control widerange of soil moisture through the corresponding threshold potentiometer control, humidity drops below a set value, the D0 output high level, is higher than the set value, the D0 output low level. Similarly, the A0 pin varies the voltage level according to the soil moisture level. JAVA has been used for the client program of the soil moisture sensor. The moisture level is shown in a chart, which helps the user to detect

Fig. 9. Rover

GPS Plotter Software- Interface that shows Current Location of the

To locate the rover, it’s GPS co-ordinate position is required. The GPS shield [22] by ITEAD studio is used to record the GPS position of the rover. The GPS shield is compatible with Arduino and along with the Arduino, a GPS antenna acts as a GPS receiver. This GPS shield is based on u-blox NEO6M GPS module and communicates with the RX, TX pins

of Arduino mega. GPS data is received in NMEA format and every received string is sent to the client software in control station via Ethernet shield. Arduino Ethernet library is used to serve this purpose. The client software in control station is a JAVA software, which shows the real time navigation of the rover. It processes the raw GPS data and extracts the latitude and longitude of the rover position and continuously plots them in a map. The map is built by the 2D projection of GPS coordinates on a 980 pixel x 690 pixel rectangular plane. The GPS position of each point on the map is shown whenever the mouse cursor is placed on that specific point. The map considers the control station as the center and can cover a circular area of radius 0.2 - 5.0 Kilometers around it. It takes latitude and longitude of the control station and radius around it as input parameter, which can be adjusted later. It can plot the pickup point, delivery point and other relevant points in the map from user input. Plotted points can be removed after the successful delivery of packets to the specified locations. A log continuously plots the rover position which is useful to rescue the rover in case of any emergency. The map can be zoomed in or out up to a certain range. The software can calculate the distance between two specific points using Haversine formula. These points can denote the rover, the control station or any point previously plotted by the user. G. Central Software Integration A central JAVA software integrates all other software into a single package. It simply creates a new process for every individual software on user request and keeps record of the timings and details. It includes a simple notepad for any quick notation (when necessary). It also handles the errors related to process response. VIII. TASKS AND F EATURES A. Astronaut Assistance Task In this task, a number of tools are to be delivered to the astronauts after collecting them from various places whose GPS coordinates will be provided earlier. The rover must have the capability to roam around quite easily along with load plus its hand should be quite able to capture and hold something. A box of dimension 40 cm x 40 cm x 20 cm is attached at the rear side of rover to keep the tools and hardware after collection. In order to grasp the tools, a claw with two fingers is there in rover hand. Presence of two fingers makes the event of capturing and holding the tools more efficient. Servo motors have been used to operate the claw. At the bottom of the claw, there is an extended area perpendicular to the claw for implementing a hook like system which helps to hold the tools having ring or ring like structure.

The motor consumes a huge amount of current hence power when the wheels get stuck somewhere. In order to resolve this matter, a current control mechanism is applied in motor driver and suitable type of wire is used. C. Sample Return Task Scientific analysis of the soil sample collected by the rover to search for the existence of life- is the main concern of this particular task. The rover controller must select multiple sites which are most likely to have potential biological interest that is Photosynthetic Bacteria (such as Cyanobacteria or bluegreen algae, other bacterial colonies that are associated with desert varnishes as well as other non-bacterial extremophiles such as lichen). Then, a soil sample of mass between 25 gm to 250 gm has to be collected and brought to the control station for analysis from that site from just below the top soil at 5cm depth or even deeper. At each site the rover will take a close up high-resolution picture with some indication of scale, a wide angle panorama and a GPS coordinate. In order to collect soil sample, the rover uses a mechanical arm with scoop. Site can be chosen by controller using the main camera. After site selection, the rover would be intended to move towards that direction and collect the soil sample via scoop. The controller will make it return back to the control station along with the collected sample after taking the high-resolution picture, a wide angle panorama and the GPS coordinate of the site. To ease the soil sample testing, some analytical works had been done earlier on the soil of that arena; mainly on two kinds of soil that are mostly available in UTAH(USA) : 1) Biological Soil Crust- This kind of soil is formed by living organisms and their by-product and hence the possibility of getting photosynthetic bacteria and extremophiles is high. 2) Chemical and Physical Crust- This kind of soil have inorganic features such as salt. Thus for potential biological interest, type 1 is of main concern. ALTA II Reflectance Spectrometer is used to analyze the soil sample. For different light sources the reflectance is noted for various sites which were considered to have potential biological interest.

B. Terrain Traversing Task Traversal through a rough terrain which may comprises of soft sandy areas, rough stony regions, rock and boulder fields is the main objective of this task. Its scope also includes passing through a set of target gates (not more than 1 kilometer from the start gate). Roaming through rough terrain is a huge challenge in terms of mechanical and electrical construction of the rover. The rover possesses six legs (three legs per side) with one spring on each side. This type of structure helps the rover to maintain balance while plunging down or climbing up. The motor of the wheels are to be powerful and efficient.

Fig. 10.

Soil Structure Captured via USB Microscope

To analyze the soil sample on site, some testing equipment have been used. For example, USB Microscope is used to get a

TABLE II R EFLECTANCE S PECTRA OF THE C OLLECTED S OIL S AMPLE (C OMPARISON WITH S TANDARD VALUE ) Control Control Wavelength(nm) Reflectance (%) 465 14 520 19.8 555 25.9 590 29.5 600 30 645 27 700 32.5

Sample Sample Wavelength(nm) Reflectance (%) 470 14.39 525 21.5 563 21.5 585 32.5 600 30.43 645 33.15 700 31.46

visual representation of the soil structure and compare it with the usual structure of Biological Soil Crust. Actually, ALTA II Reflectance Spectrometer is used to find the characteristics of the soil in the presence of different light sources. An experiment was done on the soil of UTAH to examine the soil attributes in presence of microbial extremophiles. For different light source the Control headed values were taken. In the competition site, the Sample headed values were taken using the Reflectance Spectrometer. The data analysis report denoted that, the selected site contains microorganisms. The manufacturer recommended formula for the Reflectance calculation is, (SampleV oltage−DarkV oltage)×100 Reflectance(%)= (F ullRef lectanceStandardV oltage−DarkV oltage) In this experiment, the Sample Voltage is obtained from the spectrometer, Dark Voltage = 28V and Full Reflectance Standard Voltage is obtained from a photographers 18% gray card. A pH meter is used to determine whether the soil is acidic or alkaline. Although Biological Soil Crust do not take part in chemical reactions but this test checks to see whether the soil is suitable for those living things or not.

IX. O BSERVATIONS AND E XPERIMENTS Several experiments were conducted prior to the competition to ensure proper functionality of the rover. The periphery of the experiments was both simple and complex. This helps to determine the future encumbrances in actual field accurately. The experiments can be split into several steps: A. Mechanical Test To test the applicability of the rover mechanics, some specific tests were done. Among them mentionable are: • Test run 1, terrain: medium, sandy field with rocks and obstacles; vision: rover camera; supervision: two team members followed the rover; control: blindly from control station; status: success. • Test run 2, terrain: rough, rocky field and tough obstacles; vision: rover camera; supervision: two team members followed the rover; control: blindly from control station; status: success. • Test run 3, terrain: harsh surface with bricks and rocks, vision: rover camera; supervision: two team members followed the rover; control: blindly from control station; status: success. B. GPS Test To improve the accuracy of GPS, several considerations were taken into account. Among them the most significant was to take mean value of several GPS data but this method tends to slow the process down. Data was read for 5 seconds then the mean value was calculated to plot the point and then for every new data, one old data was discarded. Some of the tests basing on the same approach are as follows: • Test 1: without the rover, with external power supply; location: open field; error: approximately 1-1.30 meter; status: success. • Test 2: GPS module mounted on the rover; location: open field; error: 0.5 meter approximately; status: success. • Test 3: GPS module mounted on the rover; location: open field; error: 1 meter approximately; status: success. C. Soil Test

Fig. 11. Graphical representation of the Reflectance Spectra of the Collected Soil Sample(using Data from Table I)

D. Equipment Servicing Task In this task, the rover is required to perform several skilled operations on a referenced equipment system. The rover had to travel up to 1.0 kilometer across relatively flat terrain (negligible slope) to reach to the equipment and tasks might include connecting pipes into fittings, turning valves, screwing on connections, pushing buttons and reading pressure gauges. For completing this task properly, rover should possess a sophisticated claw which has been designed accordingly. As the rover has to obtain the readings from pressure gauge, a camera is placed in a suitable position.

To complete the soil testing within 30 minutes we had to go through several observations to correct the measures we considered for calculations. We have compared the results for the collected soil with the results obtained after examining the soil of UTAH. Some of the tests are: • Test 1: soil collection: collected form a rocky, sandy area; equipment used: pH meter, USB microscope and reflectance spectrometer; soil type: biological crust; compared with: available data from internet; status: success. • Test 2: soil collection: collected from experimental area; equipment used: pH meter, USB microscope and reflectance spectrometer; soil type: chemical and physical crust; compared with: data available for salt; status: success. X. C ONCLUSION Robotics has already become one the most optimistic fields that can help pacifying human life in many aspects through diversity of its applications. The gradual development of this particular field made everyone realized about its future impact in each and every sector of our daily life. However, our effort

was to develop a human assistant whose applicability is not only circumscribed in pre-specified scientific tasks. Although the rover was designed and ornamented with capabilities and features focusing on the 8th annual University Rover Challenge to implement the assigned tasks, its software that were developed entirely by the Mongol Barota team members and associated hardware components used as well as integration amongst them made it equally capable to perform other similar tasks with accommodation of minimum modification providing almost identical rate of efficiency. In fact, various task performing capabilities of the rover can be employed in certain relevant applications in our real life. For instance, the sample return task where it can collect sample from a chosen site, in general scenario this feature can be utilized to dig soil via its claw mechanism or it may perform on a field where exposure of radiation might limit the human working capability. In astronaut assistance task, the rover has to collect and deliver tools to some specific locations. This capacity unlocks the dimension of helping human to deliver commodities to desired places such as delivery of newspapers to specific homes or food delivery or even assisting individuals in isolated industries like Cole mining. Undoubtedly, the rover can be made eligible to perform servicing jobs in automotive industries as it has been well-prepared to perform equipment servicing task. Concentration on terrain traversing task gave the rover such an infrastructure that can withstand expected adversities up to a sufficient limit and made the rover capable of exploring places that are almost out of bound for humans. The compilation of the mechanics, self-developed control system, software and hardware provides the blueprint of such a stand-alone system that can accommodate certain utilities in favor of assisting humans in various horizons. As there is no end of perfection, hence with more resources and logistics support plus keen observation of its performance on different sectors, the scope of improvement of the rover is still on the table. ACKNOWLEDGMENT The authors are highly obliged to Ministry of Posts, Telecommunications and Information Technology (MoPT&IT), Bangladesh; Trust Bank Limited, Bangladesh and Sena Kalyan Sangstha, Bangladesh for providing financial assistance without which implementation of such an expensive system within a short span of time would be just next to impossible. The Authors are extremely grateful to the Authority of Military Institute of Science and Technology (MIST), Dhaka, Bangladesh and Department of Computer Science and Engineering (CSE), Military Institute of Science and Technology, Dhaka, Bangladesh for laboratory and logistics support plus constant coordination throughout the system development. The authors would like to express profound gratitude to Major General Md. Siddiqur Rahman Sarkar, Commandant, Military Institute of Science and Technology, Dhaka, Bangladesh and Brigadier General Habibur Rahman Kamal, Dean, Military Institute of Science and Technology, Dhaka, Bangladesh for their constructive recommendation, professional guidance and whole-hearted cooperation.

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