Practical Robotics
Authors: Bill Davies
Venue:  (1997)

From the Book:Building Sophisticated Robotic Projects This book is a response to requests from second year students enrolled in the Engineering Design course at the University of Toronto. They have found information on robotics applications is widely dispersed, often fragmented and seldom practical in nature. Their observations are not unique since even experienced personnel sometimes have difficulty finding such information. Addressed primarily to students at the high school through third year university levels, this text will be a useful companion for the hobbyist, robotics enthusiast, and those who love to experiment. Mathematics has been used only where essential and a knowledge of Ohm's law and the Basic programming language are the only prerequisite for using this text. During ten years of teaching design courses I have been amazed at the capabilities of young people, and know from experience that given the tools and a little guidance their achievements are truly remarkable. At the beginning of each term I used several three-hour lectures to explain fundamentals of electronics and robotics to a typical class of 100 students - a select cadre of the best engineering prospects. I showed them videos of projects their compatriots completed in previous years. These screenings were accompanied by grunts of amazement and incredulity that such wonderful projects could be completed in a period of 10 weeks, with no prior training in electronics or computer hardware experience. Each year I told them several of the current year's projects would surpass the quality and sophistication level of their predecessors. They always fulfilled this prediction. A magic elixir?What is the secret formula to their success? Intelligence, dedication, perseverance, synergistic group activities, high tech support equipment, adequate guidance, moral support, expensive tools and hardware? Well, some portion of each of these ingredients is necessary, except the expensive items. Students work in groups of two to four, choose their own project, make all hardware elements they require, and also shop and pay with their own money for components they need. Selecting appropriate devices, shopping wisely and using such purchases with prudence, is an invaluable learning experience for budding engineers. Working as part of a team prepares them for real world engineering. Students' interests are eclectic, their projects spanning the gamut from humanitarian: (Head Controlled Mouse, Electromyographically Controlled Wheelchair), musical: (Trumpet and Articulated Piano Players), sports: (NHL Air Hockey, Ball Catcher), marine: (Robot Submarine, Squid Tracker), pastimes: (Computer Controlled Mechanical Rubik's Cube Solver, Chess Player). These are not singular successes, each year 90% of all projects met their objectives and over half were chosen for special recommendation. Many projects were at the fourth year bachelor's thesis level, complemented by comprehensive and erudite final reports, portraying understanding and insights well beyond their authors' years. Why is this so? I believe young people are charged with innovation, intelligence, a will to succeed and that wonderful youthful innocence of not knowing that something is `impossible'. Such latent potential is just itching to be released. Yet perhaps the most important element is that when pursuing their own ideas a project becomes a labor of love that is `theirs'. This may give the impression that the instructor is an inconsequential part of the control loop. Not quite, since students need a source of experience and inspiration when things are not going the way they should. They need to know which multiplexer to use, "How can I bend acrylic sheet?", "Is there a simple inexpensive electronic level sensor?", "Can I tell which way this motor is turning from my encoder disk output?", "How do I switch 40 amps at 12 volts?", "Will I be able to control this 60 psi air flow remotely using an IR link?", "Can this laser beam be occluded in 60 microseconds?". Answers to such questions are currently an instructor's domain, but comprehensive texts should make things easier for students. Hopefully this book will be of interest to others too. Teachers and students will benefit from techniques and protocols suggested here. Hobbyists, experimenters and those who love to tinker will find something of consequence. Because unique solutions are described that have never appeared before in print, there may be something of interest for many. I have spent endless hours solving problems for students, but the real fun for me has always been just fiddling with hardware. Because the robotics field spans so many disciplines, introducing neophytes to every robotic technique required during a single course is not easy. In this book a phenomenological interpretation of the function and utility of devices is stressed, and practical applications are given in many cases. Playing with the systems described, promotes a depth of understanding and familiarity that can be obtained in no other manner. "How much does it cost to build a robot?" An important parameter for an individual experimenter is cost. Budget limitations place restrictions on size and complexity when building a project, and demand circumspection in spending habits. The question of "how much will it cost?" has been addressed, and prices (in 1997 US$) are given for many items, also sources where these may be purchased. Although time changes the absolute cost of everything, estimates of up-to-date values may be obtained by inter-comparing current prices of different items. Such relative scaling works well over many decades, because individual prices escalate in lockstep, until items are obsolete. Information sources for beginners My own experiences have been culled from many sources, and some of these are listed in Appendix B. It is important that both teachers and students have a knowledge of `what's out there' and where this information can be obtained. It should not be necessary for a novice to complete a literature search before beginning a project. Classics such as Don Lancaster's Cookbooks and his columns in popular magazines, are milestones in their fields and important for both teachers and students alike. Forrest Mims' notes are readable and satisfyingly practical, making even a tyro immediately comfortable. Unfortunately only university libraries now have large selections of technical books, but these establishments are in many cases open to everyone. It is a sad commentary on current societal interests that 621.x, 629.x, 681 .x book sections in most public libraries are minuscule fractions of those devoted to fiction, cooking or diet! SI versus American units Readers will find a mix of units is used in this book, unfortunately this is a necessary practicality. In North America most items are still sold by the foot and pound. Being familiar with this system is necessary for our future engineers, because structures and devices based on this measurement system will be around for decades. Most materials and instrumentation sold by surplus houses have their specifications based on US dimensions, and many offshore suppliers of new equipment still tailor their products to satisfy the US market. Conversion to SI is straightforward, and equivalents are given where confusion may arise.