Design and Development of Control and Communication Systems for Complex Mobile Robot and Manipulator Structure J. Velagic*, H. Balta** *Faculty of Electrical Engineering, University of Sarajevo, Sarajevo, Bosnia and Herzegovina, (Tel: ++387 33 25 07 65;e-mail: jasmin.velagic@etf.unsa.ba) **Faculty of Information Technologies, University of Mostar, Mostar, Bosnia and Herzegovina (e-mail:haris.balta@fit.ba) Abstract: This paper describes how LEGO kits can be used to teach design and building of the complex robot system composed of the mobile robot platform and the robot arm. Both parts of proposed system are equipped with appropriate microcontrollers, sensors and actuators. All mechanical and electrical components are parts of Lego NXT Mindstroms TM Educational Robotic Kit. The control and communication software supports were building using Java programming language. This system could be controlled in two different modes, direct and Bluetooth controls. The effectiveness of the proposed complex system is demonstrated through several experiments, which provide an innovative use of the LEGO kits in robotics courses. 1. INTRODUCTION Robotics is leaving the manufacturing and production sector to become an integral part of everyday life. It is starting to be a part of the daily lives of many people. For the past several years, universities have been offering a broad variety of robotic courses, dealing with mobile as well as fixed robots, kinematics, control, bio-inspiration, and so forth (Fiorini, 2005). Many students have few opportunities to have hands- on experience on the design and fabrication of robotic devices. On the other hand, it is well known that students’ active involvement in a subject, while they are also learning its theoretical aspects, plays an important role in concept assimilation and in mastering the acquired concepts. Robotics requires long and expensive processes to complete a realistic design and safe usage of it. From these reasons, a few companies have developed and commercialized small robotics devices, or robotic kits, that let students apply their knowledge safely. Educational researchers have long suggested that instruction utilizing a variety of delivery modes helps students with differing learning styles to better understand the studied material. The one of most using robotic Kit which helps students to realize and implement their ideas is the LEGO Mindstorms TM robotics platform and the leJOS firmware (a Java based OS). The Lego Mindstorms TM robotics kit contains a programmable Lego brick (called the NXT brick), a variety of sensors (light, infrared, sound), several motors and normal Lego components (gears, pulleys, wheels, bricks, etc). This kit can be used to build robots which are identified in the manuals provided, or to create your own custom-made robot. LEGO robots provide excellent platforms for teaching various subjects of computer science. For instance, LEGO robots have been exploited to teach introductory programming (Hood and Hood, 2005), java bytecode (Jipping et al., 2007), graphical user interfaces (Challinger, 2005), image processing (Stevenson and Schwarzmeier, 2007), systems related courses (Klassner and Continanza, 2006) and robotics (Kumar and Meeden, 1998; Bagnall, 2007). A particular application of Lego Mindstorms TM Kit is in mobile robotics and artificial intelligence (AI). It allowed students to apply a variety of the AI topics studied in the classroom to the construction/creation of student-built robots to solve a diverse set of tasks. These AI topics included problem solving – using simple search, informed search and exploration techniques such planning and multi-agent communication (Thomas et al., 2002). Also, strengthening studies have attracted attention in the field of adapted learning control and neural networks control in recent years (Fujisawa et al., 2003). In this paper a complex robotic system consist of mobile platform and robot arm are designed for an unknown path following, obstacle avoidance and object moving from a trajectory. Mechanical structure of this system are build using Lego parts, such as wheels, joints, gears, belts, etc. The control and communication software is written in Java programming language and its execution on the robot is under operating system called LeJOS (Lego Java Operating System). This operating system allows the execution of Java code on the robot and includes a set of Java classes to control the different functions provided by the robot. The particular software module for remote control of the robot system over Bluetooth communication by PDA device is build. The special focus is on verifying Mindstorm's validity as an educational and scientific tool by using it for the manufacture of the target robot, and in the design of a strengthening study system. For testing this statement a several experiments were executed in this paper.