WIFI ENABLED SMART ROBOT Shashank U Moro School of Mechanical and Building Science, VIT University, Vellore-632014, TamilNadu, India moroshash@gmail.com; +91-9597428287 Abstract: The field of robotics has seen exponential growth with the amalgamation of multiple domains. This holistic approach is proving to be a boon, where communication engineering, mechanical engineering, embedded systems and so many more are together creating robots with high flexibility. Present technologies can only control robots up to a radius of 500 metres, but our aim in this project is to target controlling a robot from a remote location which is more than 1000 miles away. We use WiFi as the medium for communication. We are achieving this operation by communicating using two computers. These computers connected to the WiFi pass on serial data and also communication is established between one computer located near the robot and a microcontroller present, which controls its trajectory. Moreover robot will be having its own senses to dodge obstacle, which will also give details about its position. Future scope of this project is to establish the same connection but make the bot intelligent and autonomous. Keywords: Embedded Systems, Wi-Fi Communication, Serial Communication Introduction In the present day, technology has so improved that an Unmanned Aerial Vehicle (UAV) also called as Drone can be controlled from a distance ranging from 2km to 20,000km. The Mars Rover, which was sent to Mars to explore various features of the planet is an autonomous robot which is programmed such that it performs the desired task as it is intended to do. There are many such systems which are controlled either by Radio Frequency transmission or by creating intelligence. Such robots are called Non-autonomous robots. These robots have the programming logic to do the desired task but the decision power lies in the hand of controller (human) handling the robot. Here the interface can be made using two methods: a. Wired Here the connection between controller and robot is maintained using wired interface. This interfaces can be serial or parallel but the underlying technology is transmission of signal, which is sent in the form of specific pattern to the robot to carry out the specific task, analyses these patterns with the help of a microcontroller governing its motion.
b. Wireless Here the connection between controller and robot is achieved by wireless interface such as WiFi Wi Max Zigbee and many more The underlying technology is transmission of signals wirelessly in air by transmitter which is captured by the receiver and sent to microcontroller mounted on the robot to carry out the task. Looking at the present demand for robots in this developing world to carry out work effectively and accurately, the development of cost effective robots is necessary. Design Overview Module-1: WiFi enabled smart robot is a system which can be controlled using a custom designed webpage. To make this feasible, an microcontroller board with an Ethernet Shield is used which guides the robot along the desired path. Switch control mode of robot is controlled using joystick and can be appropriately guided back, forth, left and right. In this project, we have extended an interface to the switch control mode which suits our requirements. Finally we are successful in interfacing our robot with the and eventually control it in the wireless environment through the control buttons on the custom built webpage. Web page for robot control Wi-Fi Connectivity Router connected to internet Wi-Fi enabled robot controlled through webpage over internet Motor driver circuit- L293D board with Ethernet Shield Wi-Fi Connectivity Internet Router connected to internet Fig.1 Functional block diagram of Wi-Fi Robot
From the block diagram, it is evident that the control over robot can be achieved from the custom designed webpage and hence the robot can be maneuvered in the designated directions. When the allocated web address is entered in the web browser, webpage containing the control of robot gets loaded. When clicked on the respective direction controls on the webpage, the subsequent control packets are generated. These packets are transferred via internet and is received by the Ethernet Shield serially through the router at the receiver end. The data is then transferred from the Ethernet Shield via an SPI interface into the board and with the help of a motor driver circuit (L293D), the designated directions are henceforth assumed. Module-2: In the first module, we have successfully achieved the mobility of robot via internet. This module describes controlling the robot using. Here we have used a module connected to the board which is encrypted by a MAC address. We have created an android applet with java which communicates serially with the board. By entering the allocated MAC address of the module, the connection between board and android phone is achieved. Controlling the direction of motion of robot is achieved by tapping the specific icon on the android phone. Android phone with applet board with module Robot controlled via Motor driver circuit- L293D Fig.2 Block diagram of enabled robot Hardware Setup The hardware setup consists of following components. Microcontroller: The microcontroller board used in this setup is Mega ADK based on Atmega2560 which has 54 digital I/O pins and powered via the USB. It has a clock speed of 16MHz and can be programmed by software. The ADK has a number of facilities for communicating with a computer, another, or other microcontrollers.
Fig.3 interfaced with module and robot Ethernet shield: It has an Ethernet port which allows to connect it to the Ethernet port of a computer or a router. It is placed over the board with the specified digital and analog pins mating each other and power to run the Ethernet Shield is drawn from the board itself. The packet data from internet is transferred serially to board via the Ethernet cable connected between Ethernet Shield and computer. modem: In the module-2 of our project, we are controlling the robot via a from an android phone. This requires a UART (Universal Asynchronous Receiver Transmitter) modem at the receiver end which is connected serially with the board. The modem is powered by board and is encrypted with a MAC address which when entered on the android phone, achieves communication with the board. Prototype vehicle: We are using a four wheeled vehicle as shown in Fig.3 which will house the board with Ethernet Shield, motor driver circuit, modem, wireless camera and the power source. The vehicle is driven by a 12 volt, 60rpm DC geared motor and will be able to perform all the maneuverers as desired by the controller. Camera: A wireless camera with a TV tuner card is used to obtain the video feedback from the robot during its motion when it is controlled from a remote location. This video feedback helps the controller to control the direction of motion of robot along the desired path. Power source: To drive the vehicle, we are using a 12 volt rechargeable battery which gives the maximum speed and torque. The board and Ethernet Shield is energized by a 5 volt battery which synchronizes with its operating voltage. Hence we are using dual power source to meet our requirements.
Software Integration Mega ADK board can not only be programmed using software but with also through Eclipse, Processing and LabView. We chose to program the control algorithm in software by creating a webserver. The webpage contains icons clicking upon which will guide the robot to move back, forth, left and right. The webpage is accessed via internet and commands are sent via router in packets which is received at the receiver end and transferred serially by the Ethernet port of Ethernet Shield into the board to control the motion of robot. For module-2, we used java for programming to control the robot. Programming is done in Eclipse, which is a tool for creating an applet from java programming language. The java programming is so done that, the icons in applet resembles the control done using a joystick. Applet is saved in.apk format and transferred to android phone. By entering the MAC address of modem, connection between board and the phone is established which allows the user to control various motions of the robot. Result The hardware components are successfully assembled and interfacing the microcontroller with robot is achieved. Controlling the motion of robot via webpage as well as from android applet is successfully obtained. Conclusion Hence the two modules of controlling the robot is successfully tested and demonstrated. Though controlling using limits the range of distance for communication, a smart and easy means to guide a robot is achieved. Controlling the motion of robot via internet is one of the easiest means as it requires the user to access the designated webpage to guide it. This system can be used in defence applications for detecting landmines in war field and for bomb detections by mounting a metal detector sensor on it. Further, the size of device can be miniaturized based upon specific applications. References [1] Wi-Fi Robot For Video Monitoring & Surveillance System by Pavan.C, Dr. B. Sivakumar, International Journal of Scientific & Engineering Research Volume 3, Issue 8, August-2012 ISSN 2229-5518 [2] www.wifibot.com [3] A Wi-Fi Enabled Robot by Mohammed Hisham, Sudhir V Prabhu, Ashwin Kumar, Manipal Centre for Information Sciences, Manipal University, Manipal, India [4] Networking and Internet Applications by Sangay Yeshi