invaluable teaching tool for all aspects of Engineering. Several robotics ... the areas of computer science, mathematics, physics, mechanical engineering ...
Development of an Undergraduate Robotics Course Rachid Manseur Electrical Engineering Department University of West Florida Pensacola, Florida 32514
Abstract: Robotics is a multi-disciplinary subject typically taught at the graduate level. Yet, because of its multidisciplinary nature, robotics is an ideal example of curriculum integration. Students are forced to combine knowledge acquired in a variety of classes across different disciplines. This paper discusses several issues related to the recent development of an undergraduate robotics course at the University of West Florida. The course includes elements of classical robotics such as kinematics, dynamics and control of robot manipulators and robot building concepts. The course culminates in a robotics competition in which teams of students build robotic devices that compete against those of other teams.
Introduction Robotics offers an opportunity to apply many engineering concepts to practical situations and as such is an invaluable teaching tool for all aspects of Engineering. Several robotics subjects require a mathematical background beyond the undergraduate engineering level. The main challenge in the development of an undergraduate course in Robotics has been to effectively review the course organization in terms of content and complexity to make it acceptable and enjoyable to junior and senior engineering students. Robotics is a multidisciplinary science that encompasses the areas of computer science, mathematics, physics, mechanical engineering, industrial engineering, electrical engineering, computer engineering, materials science, and manufacturing engineering among others. It provides an opportunity to break the barriers between all these disciplines in a single course and it offers an excellent example of multidisciplinary integration for engineering students. In recent years, several institutions, following the lead of the now famous 6.270 robot-building course at the Massachusetts Institute of Technology [1], now offer robot building classes and laboratories. Simplified project-oriented robot building classes are also generating much interest as a way to get middle- and high- schoolers interested in Science and Engineering. Some graduate level courses in Artificial Intelligence also rely on robot building techniques to illustrate general concepts of decision-making and machine intelligence [2][3]. The mathematical level required to study robotics has kept it out of the undergraduate level for many years but
recent advances in hardware and software tools for education greatly alleviate the numerical and symbolic computation burden on the students. Notable examples of software packages for Computer Aided Robotics Education (CARE) include the Robotics Toolbox for MatlabTM, developed by Peter I. Corke and generously provided free of charge through the Internet [4]. The program Kinematics Analysis Package (KAP) developed by the author [5] is also useful and also available free of charge to educators upon request. Tools like MatlabTM or MathCadTM, and LabViewTM for numerical computation and simulation, MathematicaTM and MapleTM for symbolic computation, allow students to concentrate more on the fundamental concepts of Robotics rather than the tedious computations involved. Further help in teaching robotics to undergraduates comes from recent developments in inexpensive microprocessorbased control boards that are easy to program and to use in the control of small robotic devices. Examples of such controllers are the MC68HC11 EVBU available at low cost from Motorola, the 6.270 kit, the miniboard, and the handyboard developed by the MIT media lab (also based on the Motorola MC68HC11 microcontroller) [1] [6]. Control boards based on the IntelTM 8031 or 8051, or the MicrochipTM PIC family of devices is also available. These controller boards can be purchased in kits that include hardware, software, and development tools that make them ideal in support of small robotic experiments and projects. In this paper we will present a robotics course for undergraduate electrical engineering students developed at the University of West Florida. Unlike many robotics courses offered in various academic institutions, this one combines classical robotics concepts such as robot manipulator kinematics, dynamics and control, with robot building techniques where students use Legos and various electronic devices to design and develop a robotic device.
Course Organization The course title is “Elements of Robotics”. It is offered as a 3-semester credit hour Electrical Engineering elective course. Its main objective is to provide senior undergraduate students with broad knowledge on robots. The class consists of two hours of lecture and a three-hour laboratory session weekly or three hours of lectures on
weeks when a laboratory is not warranted. The lecture part is used to teach fundamentals of robotics while the laboratory portion teaches hands on robot building techniques.
Part 2. Robot Building Techniques •
Course Content The course is divided into two major parts. One is concerned with “classical” Robotics, which covers geometric models of robot manipulators, kinematics, dynamics, control, and path planning. Many excellent textbooks in this area are available. The author has used and particularly recommends the texts by John J. Craig [7] or P. J. McKerrow[8]. The other part is more laboratory oriented and covers robot building techniques, microcontroller programming, sensors, and sensor interfacing circuits. Textbooks in support of robot building techniques include those by J.L. Jones and A. M. Flynn [9], F. Martin & al. [1] [6], and G. McComb [10].
Part 1. Classical Robotics This part of the course is an excellent preparation for those students that intend to pursue graduate studies in robotics. The concepts presented are listed here. •
•
• •
•
Review of Mathematical concepts. This part is a review and an introduction to trigonometric functions, vectors and matrices, and geometric transforms such as translations and rotations of objects in space. The use of Matlab in solving numerical problems is examined through lecture examples and homework assignments. Kinematics of robot manipulators. The use of the Denavit-Hartenberg [11] model for robot manipulators is introduced and the study of direct and inverse kinematics is presented. Students are taught to use the Robotics Toolbox for Matlab and the KAP program to solve kinematics problems. Robot path planning and generation. Student are taught to use cubic splines to determine a path for the robot between two end points. Dynamics and Control of a Two-link robot. The students are introduced to the concepts of NewtonEuler dynamics only in the case of a two-link robot. Classical joint-position and velocity control is also examined without delving too deeply into this subject. Robot Manipulator Programming. A small five-axis educational robot, a Scorbot ER-V, provides students with a test bed for robot manipulator programming. As a laboratory exercise, students program the Scorbot ER-5, for a pick and place task or a simple assembly task.
•
•
•
Mobile robots. Students are given a set of Legos with DC Motors and asked to experiment in building small mobile robots of various shapes and capabilities. Microcontrollers and programming. The Handyboard, a Motorola 68HC11 based microcontroller board developed by the MIT Media Lab is used to teach students sensor-based control of DC motors. The board, small size and battery powered, is designed to easily interface to a variety of sensors and control up to four small DC motors. On the software side, a C-like language called Interactive C (IC) [1] [9] has been developed to easily program the handy board through a personal computer. Sensors. Students are taught the principles of operation of a variety of sensors for position, velocity, acceleration, proximity and range, heat, and light. Robot building contest. The class is divided into teams of 3 or 4 students. A robot contest theme is adopted early by the class and each team designs, builds, and programs its own robot for this competition. The class contest acts to motivate student interest in learning the material presented in the lectures.
Laboratory Equipment Support In an undergraduate engineering program that has a fully equipped Circuits or Electronics laboratory with equipment such as scopes, signal generators, power supplies and the likes, only a few inexpensive additional items are needed to support a robot building laboratory. An optional small educational four- or five-axis robot manipulator can be used to illustrate concepts of robot manipulator kinematics, path planning and task programming. A set of handyboard controllers, Lego sets which include DC motors, microswitches, Light Emitting Diodes (LED) and light sensors (photocells, and phototransistors) constitute the bulk of the equipment needed to run the robot building laboratory and the class contest.
Student Response The robotics class was offered for the first time at the University of West Florida during the Spring 96 semester to twelve senior electrical engineering students. Their response to the course was overwhelmingly favorable. So much so that many students have been requesting that the class be offered again. The course has
a level prerequisite of a course in Signals and Systems which guarantees that all students enrolled are at least in their fourth semester of the Electrical Engineering upper division program. Students also consider this course to be a good preparation and field of study for the degree program capstone design course requirement. Many students that have taken the robotics elective have later chosen to complete a Senior Design Project in the field of Robotics.
The Class Robotics Contest The class contest was organized with three teams of four students each. The project topic was to build an autonomous vehicle that could navigate its way through a thirty five-foot path delimited by two black lines on a white background while avoiding obstacles. The three robots were noticeably different in their mechanical design, sensor layout, and programmed responses. The winning robot had the sturdiest mechanical design, the most down-to-earth approach to perceived changes in its environment, and the simplest programming. It is interesting to note that the worst-performing robot in the contest had the most sophisticated programming planned by its designers. The contest was covered by a local television station and, according to the students, was a particularly enjoyable part of the class.
Conclusion This paper has discussed the development of a course in robotics for undergraduate engineering students. The course combines lectures on classical robotics with robot building techniques. In classical robotics, the course covers robot manipulator modeling, kinematics, path planning and trajectory generation, dynamics, and task programming. This part is an excellent introduction to general robotics and adequately prepares students to graduate level courses in Robotics. The second part is a robot building series of lectures and laboratories that covers microcontroller programming, lego-robot building, sensors and sensor interfacing circuits. The course culminates in a class competition where teams of students compete with robotic devices of their design. The competition offers an opportunity to apply the knowledge gained and to contrast different design philosophies.
References 1.
2.
Martin, F., Oberoi, P., Sargent, R., The 6.270 Robot Builder’s Guide , MIT Media Lab, Cambridge, MA, 1992. Turner, C., Ford, K., Dobbs, S., Suri, N., & Hayes, P., “Robots in the Classroom.” In J. Stewman (Ed.),
Proceedings of the Ninth Florida AI Research Symposium (pp. 497-500). Key West, FL:FLAIRS. 3. Turner, C., Ford, K., Hayes, P., Shamma, D., Manseur, R., “Robots in Education”, Proceedings of the US-Japan Graduate Student Forum in Robotics, Osaka, Japan, November 1996. 4. Corke, P. I., “A Robotics Toolbox for Matlab,” IEEE Robotics and Automation Magazine, March 1996. 5. Manseur, R., “A software package for computer aided robotics education,” proceedings of the IEEE/ASEE Frontiers in Education Conference, Salt Lake City, Utah, Nov. 1996. 6. The Handyboard WWW Page: http://lcs.www.media.mit.edu/groups/el/projects/handyboard/. 7. John J. Craig, Introduction to Robotics, Mechanics and Control, 2nd Edition, Addison-Wesley. 1989 8. McKerrow, P. J., “Introduction to Robotics,” Addison-Wesley, 1991 9. Jones, J. L., & Flynn, A. M., “Mobile Robots, Inspiration to Implementation.” A.K. Peters Ltd. 1993. 10. G. McComb, “Robot Builder’s Bonanza, 99 Inexpensive Robotics Projects”, McGraw-Hill, 1987 11. Denavit, J. & Hartenberg, R. S., Trans. Of the ASME J., Appl. Mech. Vol. 77, pp. 215-221.
