Robinson - Robotics and its Applications for Physics Students Sabina Jeschke, Ursula Vollmer, Marc Wilke University of Stuttgart Germany {sabina.jeschke, ursula.vollmer, marc.wilke}@iits.uni-stuttgart.de
Olivier Pfeiffer Technische Universität Berlin Germany
[email protected]
Abstract: The Robinson curriculum contains a novel approach aimed at enriching academic physics education by providing early applications of physical knowledge in a popular field of technology, robotics. At the same time, it aims to enhance the technological literacy of students while increasing the overall number of students, especially young women, in the fields of physics and engineering. Robotics holds a unique role due to the multidisciplinary foundations of the field, ranging from electrical and mechanical engineering, software and hardware design to team building and problem solving skills. Robotics allows hands-on teaching of scientific and engineering methodologies at an early stage of the students’ academic education. As a result, robotics are well suited for problembased learning (PBL) (Mayo et al 2007 and Richter et al 2007), motivating the introduction and application of physical laws and concepts. Our approach focuses on the multidisciplinarity provided by robotics rather than on computer science education. Students are free in their choice of tools and not supposed to learn the programming basics of one specified programming language. The main intention of the project is introducing the engineering process and bringing forward team and social skills, so creativity is activated and teams can start building their own robots.
Introduction Physics play an important role in the design of robots. The design of robots is often subject to limitations based on weight, space, cost, and energy efficiency. It is therefore often necessary to find less than optimal compromises in the components and technologies used. The application of physics can help to enhance the chosen technologies beyond their obvious capabilities. Especially limited sensor suites can profit from these applications. The kinematics of a robot pose additional challenges for the application of physics, in particular technical mechanics. Imprecise control of the actuators combined with limited navigational systems requires careful consideration of influences like friction in the design of all kinematic components. Joints and actuators limited to a single degree of freedom result in complex, spatially extensive constructs. Describing their movement requires homogenous coordinates, and the application of varied analytical and numerical methods to solve the problem of inverse kinematics. The above examples can be extended to include problems from thermodynamics (motive systems) and solid-state physics (electronics, sensors, and power supplies), covering a broad spectrum of physical theory and subfields. In addition, the field of robotics itself enjoys a widespread popularity in modern society as shown in numerous works of literature and film. As a result, robotics is well suited as a motivation to both introduce physical laws or to apply physical knowledge already gained and is therefore useful in creating or increasing the interest of students in physics. The Robinson program takes advantage of this by embedding physical theory in a robotics project, where students design, build, and test a robot. The broad spectrum of topics relevant to robotics encourages team work and close cooperation between team members from different fields (Blank 2006). The required soft skills cannot be communicated in theoretic lectures, but have to be acquired in practical training. Solving problems in a small team during the project contributes to developing and enhancing social skills students will need in their professional life as scientists (Jeschke et al. 2006 and Dahlmann et al. 2007).
Modules of the Robinson Program The program consists of four modules that have robotics as a common basis for education. These modules differ in their target audiences and in their goals (see Fig 1). This overall view is thought as an overview on the whole Robinson program. It shows how the curriculum for engineering and physics students is embedded in similar courses with other target audiences. The first three modules are quite similar in their curriculum, as they are all integrated courses for university students. Students from these courses may attend a course and gain an official certificate from the IAIS Fraunhofer Institute. With this certificate, the students may function as course leaders for module D (“Roberta”) courses (St. Augustin 2006). This allows them to deepen their understanding of the subject and gives them a positive feedback and further possibilities to train their social skills. In the following sections, module B (“Robinson Ing”) will be described in more detail. Technologically, students are encouraged (but not limited) to use the well-known LEGO Mindstorms series of robots (Bongaarts et al. 2007 and Kelly 2007).
Fig. 1. Modules of the Robinson-Program (March 2008) “Robinson Ing”: – Robotics for Students of Engineering and the Natural Sciences Robotics include numerous challenges for applied physics, ranging from static mechanics in the construction of the robot’s body, over kinematics to analyzing the data of sensors or building new sensors for a specific task. This makes it suitable for giving students a possibility to apply their newly gained physical knowledge in real-life problems. At the same time, the course aims at training team skills and conveying methodologies for solving complex interdisciplinary challenges. The course consists of three basic components: The first component is a series of lectures providing the necessary theoretical foundation and an overview on robotics. The second component comprises practical application of this knowledge in a hard and software project. Finally, the third component consists of the presentation and discussion of the results in front of the whole course. This integrated course allows not only addressing the aims outlined above, but also trains additional skills useful for the working place. These include product-oriented work style under strict time constraints and presenting solutions and results to colleagues. The course is aimed at bachelor students of engineering and the natural sciences.
Robinson – Didactic Approach The “Robinson Ing” module is designed and lectured as an integrated “interdisciplinary robotics laboratory: soft and hardware engineering” for students of engineering and the natural sciences. It will be held each semester during regular term or as a compact course in semester break and consists of three basic components: 1.
a series of introductory lectures, giving an overview to selected principal topics with reference to robotics (2 hours per week, 11 weeks),
2. 3.
a practical training in small groups of 3-4 students designing, building and programming whole robots or robot components (4 hours per week, 11 weeks), and a seminar and presentation part, giving the teams the possibility to demonstrate their project results on a project web page and to introduce it to their lecturer and fellow students during an oral presentation in class (6 hours per week, 2 weeks).
After some introductory lectures, students are supposed to form teams and choose their project topic. Before implementation starts, the topics are to be presented by the students. During the implementation phase, lectures focus on different aspects of robotics. Thus, the course includes all components of an “integrated course”, which makes it a complex, but also highly challenging course, of which the students profit in many ways. All components, i.e. the lectures given by the instructor, the hands-on training, and the students' presentations contribute to the final grades. On the one hand, students acquire important theoretical foundations and knowledge. On the other hand, they have the possibility to practice important soft skills, which they will need later on in their professional life.
Details and Realization Students are free to specify their project within very loose boundaries, allowing the integration of a wide range of interests. Most topics of classic physics can be or are addressed in the projects: •
• • • •
Mechanics: Design of a stable and stiff light-weight body, modeling the kinematics (determining the physical positioning of a part of a kinematic chain based on the position of each single joint) of a robot in homogenous coordinates and solving the inverse kinematics (determining the positioning of each single joint to reach a certain point in space) analytically or numerically, modeling the movement of a robot including friction or slip, determining the motion of a robot based on the data gathered from gyroscopic or acceleration sensors. Solid State Physics: Photovoltaic cells, thermocouple generators, nuclear batteries (common in space probes), improved sensors, more efficient main processors Thermodynamics: Efficiency of power systems, Stirling and combustion engines as power sources Electrodynamics: External power supply based on tapping into a radiation field (e.g. small robots operating in pipes powered by microwaves using the pipe itself as a waveguide, a laser illuminating the solar panels of robot in the shade) General: Detailed analysis of sensor output for improved sensor performance (for example using optical sensors of different spectral sensitivity to determine the color of a reflective object or the temperature of an emitting object under the black body approximation)
As the students are at the beginning of their studies and presumably have never seen a specification before, they are provided with a template. This is supposed to guide them in defining their projects. They are asked to describe the environment, including programming language and the necessary hardware. Product functions as well as the corresponding test cases have to be determined, before building and programming starts. Additionally students should show in a small draft what they imagine their robot to look like. The most difficult task for the students will be the estimation of effort, something hard to provide even for an experiences professional, but part of working life. The students are not judged on their exact estimation. The main issue about the specification is that the students first think about their project and then start building and programming it. For the final presentation, students have to prepare a short talk, accompanied by some slides. They are supposed to explain the difficulties they met during their project and how they solved it. A great part of the time, each group is assigned, is reserved for questions from the lecturers. By choosing the questions carefully and asking all team members on a few details, it should become clear at this point, if every student did his or her part to the project. As the first two exams focused on the practical part of the course, the oral examination will be on topics from the accompanying lectures.
State of Preparation “Module B – Robinson Ing” has been taught for the first of the Robinson courses in the summer semester of 2008. At the moment it is only credited (as a mandatory laboratory course) for electrical engineers. We are,
however hoping to be able to provide credit points (as a mandatory elective course) for students of physics in the near future.
Experiences and Evaluation The students' interest in the “Robinson Ing” course, taking place at the University of Stuttgart in the summer term 2008 was overwhelming. Students came from different backgrounds, such as computer science, software engineering, technical cybernetics, electrical engineering, mechanical engineering, physics, math, computational linguistics, and technical pedagogics. Students were willing to participate in the course, even if they could not get credits for their studies. About 25% of our students were women, whereas the overall percentage of women in engineering fields at the University of Stuttgart lies around 10%, in computer science and physics around 20%. The students chose interesting projects and were willing to invest a lot of time in building and programming their robots. One group built a robot functioning as a rolling freight depot to improve the logistical efficiency of a train station. The robot loaded (toy) trains without them having to stop or slow down. Transferred into reality, heavy freight trains would not need to be slowed down for loading and be accelerated again afterwards. Another group built a robot that serves as a plotter (fig. 4). They defined their own graphics data type, which the robot is able to interpret. The robot plots a graphic provided in the defined data type. A third example is a robot that is able to solve a randomly twisted Rubik’s Cube. The evaluation of an interrogation of the students at the end of the term provided good results (fig. 2). Most of the students stated that the course was clear and well structured. Questions, covering this aspect included the formulation of goals and requirements, the structure of the course, the relevance of the topics and references to other areas, explanations, media, and methods. The students attested a good preparation of the lecturers and a good organization of the whole course. They felt free to ask questions and place comments. The students declared that their interest in the topic has been increased by the course. They were satisfied with the variety and broadness of topics, but some would have preferred a bit more detail and challenge.
Fig. 2. Evaluation overview. The questionnaire was handed out during a lecture and evaluated centrally and completely anonymously. The lecturer only has to see the analysis, not the returned questionnaires.
Outlook From the accompanying lecture, students will gain basic knowledge in robotics and an overview on robotics. At the same time, they will learn about a multitude of topics from different disciplines, including physics,
directly motivated by their chosen robotics project. An additional direct focus is on the development of social skills. The interdisciplinary aspects of engineering students will be strengthened by this module. “Robinson Ing” will help them understand relations and relevance of different aspects in their studies. Additionally, the fun students have in building and programming their own robot will influence their interest in the related topics touched upon during the project.
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