Implementation Of Stair Climbing Robo using Microcontroller

Transcription

1 Implementation Of Stair Climbing Robo using Microcontroller Mrs.A.H.Tirmare 1, Ms.P.S.Mali2, Ms.S.M.Bhoi 3 1 Assi.Professor E & Tc Department, Bharati Vidyapeeth s College Of Engg Shivaji University Kolhapur 2 Assi.Professor E & Tc Department, Bharati Vidyapeeth s College Of Engg Shivaji University Kolhapur 3 Student E & Tc Department, Bharati Vidyapeeth s College Of Engg Shivaji University Kolhapur Abstract At present scenario robotics is a common technique of atomization to reduce human efforts, save time & to increase throughput in several applications. For the robots working on plain surface to control the movement in left right & forward backward directions various methods have been developed but for applications where stair climbing is required these traditional robots has limitations, so for stair climbing applications various techniques are developed like wheeled robots legged and robots tracked robots. The main disadvantage of these robots is they are not adjustable according to the structure of stairs. To overcome this problem following paper focuses on implementation of an adjustable stair climbing robot using microcontroller. The main application of these robots is to carry required material on the platform fir rescue operations Keywords Robot, Stair Climbing Robot, Atomization, Microcontroller, Adujustable Robot I. INTRODUCTION Robot had come to human life for the past almost 80 years ago. Adjustable stair climbing is very important feature in legged and wheeled robots. Stair climbing robots are useful in many applications like medical field or military field where stair climbing is required. In stair climbing robots development have been made on how to make stair climbing ability higher and mechanical complexity reasonable & practical. Important factor in design of robots is reduction of body weight & energy consumption so that size of battery will reduce. WHEELED ROBOTS: Wheeled robots can navigate using motorized wheels on ground themselves. Design of wheeled robots is simpler than other methods of locomotion like legged or tracked robots. Mostly there robots are used for the applications for plain terrain which is flat without any irregularities. Controlling & programming of these robots is simple than others. Major disadvantage is these robots are not suitable for areas with low friction, irregular or rocky terrain, terrain with obstacles. In wheeled robots they are classified depending upon number of wheels like three wheel, four wheel or six wheel robots. These robots are more popular due to simple design and low cost. LEGGED ROBOTS: A legged robot is most convenient for rough terrain because in rough terrain few movements are required like climbing steps, cross gaps or to walk on extreme rough terrain where use of wheeled robots is very difficult. Main factor in legged robot is degree of freedom at the joints of robot legs which are powered by servo. So as compared to wheeled robots design of legged robot is complicated & it needs more number of motors also due to increase in degree of Legged locomotion is more power efficient on soft ground than wheeled locomotion, because legged locomotion consists only of point contacts with the ground and the leg is moved through the air. This means that only a single set of point contacts is required, so the quality of the ground does not matter, as long as the robot is able to handle the ground. But exactly the single set of point contacts offers one of the most complex problems in legged locomotion, the stability problem. DOI: /IJRTER NHIAA 234

2 TRACKED ROBOTS: A tractor crawler or a tracked vehicle is a vehicle that runs on continuous tracks instead of wheels. This vehicle include military vehicle, unmanned ground vehicle.basic principle of tracked vehicle is that it remains in contact with lager surface area which not case in wheeled or legged robots. Basic advantage of this is such type of robots are suitable for soft, low friction ground like ice or snow also for uneven ground such as mud. Disadvantage is tracks utilize more complex mechanism than wheel. Figure 1: Tracked vehicle Adjustable high grip mover is one of the best solutions as the stair climber.this mechanism is a combination of rigid bodies so shaped and connected such that they move upon each other with relative motion. This structure is known as stair climbing Crawler. This crawler is built with belt tension mechanism which was used to developed to get equally distributed grounding pressure. This crawler is equipped with swing idler mechanism which is located at the same height as the front and rear main idler mechanism. When the crawler approaches the top of stairs the swing arm moves and pulls the idler up, bending the crawler belt.this motion restrict sudden change of the posture of the crawler. When crawler needs to perform pivot turning, the idler is pushed out the grounding area becomes small. II. BLOCK DIAGRAM & DESCRIPTION There are two block diagrams one for transmitter which is in hand of user where as other is receiver which is mounted on load carrying robot. 2.1Block Diagram of Transmitter Figure 2.1: Block Diagram of Transmitter As shown above Transmitter consists of joysticks used to control movement in four directions forward,backword,left,right.this signal is coupled to receiver through RF All Rights Reserved 235

3 2.2 Block Diagram of Receiver: International Journal of Recent Trends in Engineering & Research (IJRTER) Figure 2.2: Block Diagram of Receiver As shown above receiver block diagram consists of RF receiver which couples transmitted signal to receiver in order to move motor in specific direction depending upon desired movement of robot. 2.3 Hardware Details: Microcontroller used is AT mega 328.Servo motor and DC motor are used as actuators to control the movement of robot in the desired direction as per requirement. As shown in block diagram different components are interfaced with controller so as to perform controlling operation Transceiver Module: Figure 2.3.1: Tran s receiver module Transceiver module is used for duplex wireless communication between transmitter which is joystick & receiver which is robot which is RF24L01 transceiver module. Relay is used as it has better switching characteristics & ability to control high voltage circuit with help of low voltage circuit and also used when single circuit can control more than one circuit Motor: Figure 2.3.2: DC All Rights Reserved 236

4 DC motor is used for controlling movement of belt of tracked vehicle. Motor is 10 RPM 12V DC geared motor for robotics application. It gives a massive torque of 10Kgcm. The motor comes with metal gearbox and off centered shaft. Shaft has a metal bushing for wear resistance Microcontroller: Figure 2.3.3: ATmega328 Microcontroller Microcontroller is main controlling part of the system. Here controller used is ATmega328. It is high performance 8 bit microcontroller. The ATmega328P is a low-power CMOS 8-bit microcontroller based on the AVR enhanced RISC architecture. By executing powerful instructions in a single clock cycle, the ATmega328P achieves throughputs approaching 1 MIPS per MHz allowing the system designed to optimize power consumption versus processing speed Joystick: Joystick is an input device commonly used to control objects according to application. Joystick consists of a base and a stick that can be moved in any direction. The joystick can also be moved from left to right and vice versa. Because of the flexible movements a joystick allows flexible movement as compared to keyboard. Figure Joystick The joystick is used on user side to control the motion of robot i.e. movement of robot forward, backward, left and right. Analog joystick consists of two variable resistors for two axis. Each variable register consists of three pins, two extreme pins are connected to Vcc(5v in our case) and ground. The center pin is the output pin. The output voltage is between Vcc and GND depending on the position of stick. By measuring the output voltage of two variable register from which the joystick is built it is possible to determine position of stick in x and y axis. The joystick has springs to return thumb stick in to center position. So potentiometers are also centered. If there are 10k potentiometers used, then each value is centered at about 5k. So if we use 10-bit ADC we get center point at analog value 512. III. SOFTWARE DESIGN (ALGORITHM) Following algorithm contains steps for both transmitter and receiver side. At transmitter side Joystick is operated by user according to required movement. These values are transmitted to receiver through RF Transmitter as given below at receiver side initialization is done and received signal is checked by receiver according to received signal DC motor is rotated by required amount so as to control the movement of wheels of All Rights Reserved 237

5 Following are the steps for algorithm at transmitter & receiver side: 3.1. Transmitter Algorithm: 1. Start 2. Declare the pins 3. Initialize the pins 4. Read the values of joystick 5. Map the readings of joystick to get the desired output 6. Transmit the values of joystick to the receiver 3.2. Receiver Algorithm: 1. Start 2. Declare the pins 3. Initialize the pins 4. Create object 5. Attach pins to RF module 6. Is signal available? 7. If yes, rotate Johnson dc motor as per received joystick value 8. If no, keep checking the signals IV. IMPLIMENTATION & EXPERIMENTAL SETUP This wireless robotic system is developed to perform a specific task using a humanoid robot, which is controlled by a respective user, who is far apart. This system analyzes the input signals received at the user side such as joystick etc. and follow the user defined action according to these inputs. DC motors of base wheels are controlled by the joystick. Figure 4.1(a) condition of robot without climbing Operation Figure 4.1(b) climbing robot leg The joystick is basically a two potentiometer assembly with a push button at the center. Thus while programming, we can assign the forward, reverse, left or right as function keys for joystick. Thus the clockwise or anticlockwise rotation of DC motor strictly depends of signals received from joystick. The Johnsons DC motor has maximum speed of10 RPM. In order to control the speed of the robot, here potentiometer is used. Above is result of operation Fig 4.1(a) shows condition of robot on plain surface without climbing operation where as Fig 4.1(b) shows climbing robot All Rights Reserved 238

6 V. CONCLUSION Based on results it is concluded that wireless staircase climbing robot is designed & implemented successfully. The performance of system is meeting satisfactory results. This system acquires input signal at the user from joystick and these signals can be analyzed by robot. The robot is mainly motivated by the improvement of mechanical ability of tracked urban vehicle to climb the stairs. It can develop an adjustable staircase climbing robot to replace the human effort to carry out difficult task in places like office, hospitals, industrials and military automation, security systems and hazardous environment. REFERENCES I. M. Lawn and T. Shiatsu, Modeling of a stair-climbing wheelchair mechanism with high single-step capability, IEEE Transactions on Neural Systems and Rehabilitation Engineering, vol. 11, no. 3, pp , Sept II. G. Figliolini and M. Ceccarelli, Climbing stairs with EP-WAR2 biped robot, in Proc. IEEE International Conference on Robotics and Automation (ICRA), vol. 4, Seoul, Korea, 2001, pp III. J. Liu, Y. Wang, S. Ma, and B. Li, Analysis of stairs-climbing ability for a tracked reconfigurable modular robot, in Proc. IEEE International Workshop on Safety, Security and Rescue Robotics, Kobe, Japan, June2005, pp IV. R. C. Luo, K. L. Su, A multi agent multi sensor based real-time sensory control system for intelligent security robot IEEE International Conference on Robotics and Automation, vol. 2, 2003, pp V. Sandeep H. Deshmukh, Sakthivel P. & Srikanth Sankaran, Computer Aided Design and Interfacing Of EOT Crane in the Proc. of Global Conference on Production and Industrial Engineering,National Institute of Technology, Jalandhar, 2007, Session 4A, pp 1-6 VI. Jeyabalaji C1, Vimalkhanna V2, AvinashilingamN2, Mohamed Zeeshan M A3and Harish Kumar N3 1R.M.D. Engineering College, Department of Electronics and Communication Engineering,Kavaraipettai,Tamilnadu,India. 2R.M.D. Engineering College, Department of Computer Science and Engineering, Kavaraipettai,Tamilnadu, India. St Joseph s College of Engineering, Department of Electronics and Communication Engineering, Panapaakkam, Tamilnadu, India. VII. [7] Ms.A.H.Tirmare, Ms.P.S.Mali Hand Gesture Controlled Robotic Arm in International Journal of Advanced and Innovative Research, ISSN: , Volume 6, Issue All Rights Reserved 239