A Modular Educational Robotic Toolbox to Support University Teaching Efforts in Engineering Authors: Uwe Gerecke, Learning Lab Lower Saxony (L3S), University of Hanover, Germany,
[email protected] Bernardo Wagner, Learning Lab Lower Saxony (L3S), University of Hanover, Germany,
[email protected] Patrick Hohmann, Learning Lab Lower Saxony (L3S), University of Hanover, Germany,
[email protected]
Abstract Robots offer an excellent basis for teaching a number of different engineering disciplines and their integration into systems. To accomplish courses and projects, universities need robot platforms which are flexible and modular so they can be easily customized to the requirements of different subjects. This paper introduces the concepts of our Modular Educational Robotic Toolbox (MoRob) project, which aims to design and develop an advanced mobile robot system for teaching undergraduate and graduate students as well as for PhD research. At the core of our system is the Scalable Processing Box (SPB), a standardized processing platform for easy experimentation with any kind of robotic platform. Key characteristics are scalable performance, modular setup to facilitate tailoring to individual courses, flexible interfaces and easy configuration. Furthermore, MoRob aims to provide a standard set of control modules and teaching units, with a particular focus on project-based learning. Therefore, our framework not only supplies an educational robotic platform and improves student learning, it also supports teaching by reusable and sustaining material. Index Terms Educational Robotics, Robot Curricula, Evaluation of Robotics Courses, Problem-Based Learning, Autonomous Mobile Robots.
INTRODUCTION Robotics is the topic of constructing artefacts that couple perception to action to allow a system to carry out purposeful tasks for humans [2][9]. In recent years, research activity in the field of mobile robots has gained considerable momentum, and with its growing success attention is not only received in the scientific community, but also in industry. Autonomous robots constitute a clear emerging market for a large variety of potential application in a range comprising service robots, entertainment robots, as well as achieving tasks in hazardous environments or disaster areas. Going along with this development, universities teach an increasing number of courses in robotics and research students carry out dissertation projects in this area. It is an interdisciplinary subject that involves mechanical, electrical, control, and computer engineering. A key component is the need to integrate these disciplines in order to construct systems. Therefore, it offers an excellent basis for teaching a number of different engineering disciplines and their integration into systems. Robots also provide an excellent platform for demonstration of basic engineering problems in the educational effort. Practical exercises in student projects help to develop skills like creativity, teamwork, designing and problem solving. A great advantage of using robots as demonstration tools is that abstract concepts can be turned into real-world problems and solutions [7]. Motivation is improved when real-world objects are included. In robotics projects this is the case as students can see, touch and play with their project [6]. Experiences with courses utilizing robots have been reported e.g. on software engineering projects [8], genetic programming [3], Artificial Intelligence [13], data structures courses [5]. Using robots, progress can be achieved in both theoretical knowledge and practical knowledge. Reference [1] identified 17 fields in which considerable progress could be made while working on a robot contest, including physics, mathematics, systems design and teamwork practice. Robots are very popular and stimulating for university students [16] and can also be used as a motivational factor to attract high-school students to take engineering courses [11]. The remainder of this paper describes our approach to provide a flexible and modular robot platform for university teaching and research. First, the general concepts of our MoRob (Modular Educational Robotic Toolbox) project are introduced, followed by a description of the Scalable Processing Box (SPB). Then, the focus is set on applications in projectbased learning and educational evaluation of the project, before concluding the paper.
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MODULAR EDUCATIONAL ROBOTIC TOOLBOX In order to use robots in teaching, practical projects and research, universities need platforms which are flexible and modular, yet powerful, so they can be easily customized to the requirements of individual subjects. No existing platform which can be purchased "off-the-shelf" meets all requirements. A well designed educational kit available with associated learning material is provided by Lego Mindstorms. However, this has been designed for use in schools and is inappropriate for advanced classes at universities like automatic control, real-time systems, or even in robotics itself. While robots provide an excellent basis for teaching a variety of topics, a notorious problem is the lack of a suitable platform for such an effort. Often lecturers have to resort to “primitive" platforms, or construct their own systems. Using existing platforms can have the disadvantage of too many limitations to really illustrate the key concepts of a particular course. On the other hand, the effort to set up a reasonable system by the lecturers on their own requires many resources for implementation and maintenance over time. The goal of our MoRob (Modular Educational Robotic Toolbox) project is to overcome this problem and provide a suitable platform together with a standard set of control modules and teaching units. This is aimed at teaching undergraduate and graduate students as well as for PhD research. At the core of our system is the Scalable Processing Box (SPB), a standardized processing unit for easy experimentation with any kind of robotic platform. Key characteristics of this platform are standardization, scalable performance, modular setup to facilitate tailoring to courses in the different disciplines, flexible interfaces and robustness (see the following section for more details). To supplement the platform and its application in a teaching environment, one of the MoRob aims is the provision of a variety of course materials to cater for a number of different courses within the robotics and engineering curriculum. Therefore, the system will be accompanied by teaching units (course materials), which can be easily used and adapted to a variety of courses, as well as a standard set of control modules (toolboxes) for practical exercises, for example for teaching navigation or introductory control. The system and its modules also find their application in carrying out Ph.D. research, where students benefit from a system which is flexible and versatile so it can be adapted to their specific research needs. MoRob and the developed SPB allow to quickly combine the modules that the students need with only little customization necessary. Therefore, Ph.D. students can concentrate on their actual research tasks and questions very quickly, rather than having to deal with creating their research tools. All materials will be made available in a common web facility, an internet repository which will integrate course materials and technical documentation including lecture notes, slide presentations, exercises, software (toolboxes etc.), construction examples, etc. This way, the system can be shared across a number of institutions. Furthermore, MoRob will provide a model curriculum for using robots in teaching and project-based exercises. This curriculum will comprise a selection of courses which will be made available in our repository, offering a choice of teaching units and exercises in different subjects. It will comprise different approaches at different levels and integrate complementary expertise from different institutions. Individual modules or whole courses can be drawn from this model. The availability of such a standard toolkit for teaching with robots can serve as a standard platform that students become well acquainted with during their studies. Initially they might use the platform for exercises in programming, at a later stage sensors on the platform may be used for exercises in signal processing. In advanced control the students may be required to design a trajectory following algorithm or a new PID controller for improved traction. At a relative late stage in their studies they might be required to assemble a new system for a particular exercise or competition. Consequently one might imagine that the system becomes an embodied companion for exercises in much the same spirit as MATLAB as it provides a suitable tool for exercises for a variety of different disciplines and courses. Therefore, a standardized teaching environment will emerge which will be easy to use in a variety of applications. In addition, educational resources provided can be shared across a number of institutions so that material and exercises prepared can be utilized by several instructors. This way the investment in new educational material becomes worthwhile and a community of teachers can combine their efforts and experience. The MoRob project is embedded into the interdisciplinary research in educational technology at the Learning Lab Lower Saxony (L3S) in Hanover (Germany). It is a new international project which started in October 2002. Project partners are the Centre for Autonomous Systems, KTH Stockholm, and the Robotics Laboratory at Stanford University. The studies are carried out within the framework of the Wallenberg Global Learning Network (WGLN).
SCALABLE PROCESSING BOX A key part of our research is the development of a Scalable Processing Box (SPB), a standardized processing unit for easy experimentation with any kind of robotic platform. It is targeted at users ranging from students doing their first steps in the subject of robotics to researchers using the SPB as a base system for their scientific work. To fit the requirements of
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educational robotics, the box has been designed to meet the following requirements: simple handling, easy configuration, flexible interfaces, robustness from a hardware and software point of view, real-time capability and user-oriented documentation and examples. The design of the box follows an open source approach. Such approaches have been shown to be an important issue for Lego robots [10], and are increasingly becoming popular for higher-level robot platforms [12][4]. The SPB is divided into two main parts, a development environment and a runtime environment. It provides a real-time framework for simple usage of interfaces and algorithms. The basis is Linux/RTAI [14] combined with a real-time API for common interfaces, e.g. CAN bus, Ethernet, serial, etc. (see Figure 1 for a schematic overview of the architecture). The runtime system can be booted from a compact flash card (CF-card) to ensure the flexibility needed in an environment where different users have to work with one hardware platform. Due to the limited memory of a CF-card, a suitable Linux distribution has been built. It is comprehensive enough to cater for essential tasks like editing, compiling and executing of common C/C++ and Java source code, provision of a simple web interface (e.g. to handle the machine's runtime controls and presentation of results). On the other hand, not to occupy too much space on the CF-card, a number of not so essential Linux packages have been removed, e.g. X-Windows and advanced UNIX networking. A minimal system with basic functionality is smaller than 8 MB. With the development environment setup on a normal Linux machine, the developer can use all the comfortable tools he chooses to work with. After the compilation process, the developed binaries can be stored on the CF card (e.g. by a USB device or by networking) so they can easily be made available in the SPB runtime environment. To keep the handling of the distribution as simple as possible, a combination of pre-compiled packages and easy-to-use installation scripts have been created. This way, the installation of an SPB can be done in the following modular steps: setup of the basic Linux structures, the development environment, web support, real-time structures (RTAI), and real-time communication layer (RTNet [15], RTMailboxing, etc.). The modularity of the system achieved so far provides the option to set up only the required functionality of the SPB. After setup of this infrastructure, the API structures and device drivers can be implemented in additional packages for further installation steps. In one of the next stages, the scripts will be embedded in a graphical user interface (GUI) to simplify the handling of the installation process. With the included real-time networking capabilities it is possible to set up a distributed system consisting of several SPBs with different processing power and different tasks. This provides the ability of modularized development of an overall system and the re-use of expensive hardware platforms with different SPB runtime environments for several projects. The development environment is designed to be as simple as possible. This ensures fast setup of small and simple projects (only the GNU C compiler and make utility are required) as well as integration of the SPB development environment into complex development processes guided by structures for code design and software development. In the first stage, the SPB is designed to run on an Intel platform. In following stages it is planned to port it to several embedded systems (e.g. PPC or Geode). This will be promoted by the use of Linux/RTAI in the core of the system and free publication of the SPB under an open source licence system. To increase the flexibility and modularity of the system, SPB runtime and development environments will be provided for all systems supported by Linux/RTAI. This gives the user a choice to fit requirements like low power consumption, high processing power or physical size. With the abilities of distributed real-time data processing, a well structured set of software interfaces and a simple setup procedure, the Scalable Processing Box is designed to become a flexible and powerful processing standard for education and research in the field of robotics. Due to the modular and structured design, it will be possible to rearrange existing SPBs similar to Lego building blocks to fit different scenarios. With Linux/RTAI as a base and an open source approach of the SPB packages, a broad community can use the SPB and continue developing further components, for example device drivers or other real-time network components.
PROJECT-BASED ROBOTICS COURSES An essential part of MoRob is to provide a model curriculum for using robots in teaching. This will offer a choice of teaching units and exercises in different subjects, with a choice of approaches at different levels. In particular we promote problembased learning, which increases the attractiveness of learning while performing student projects through learning by doing. Furthermore, it supports the development of engineering skills like creativity, teamwork, designing and problem solving. At present, our initial focus is on the development of three courses at different levels: a Lego Mindstorms project for teaching introductory courses to undergraduates, a lab project with an ER1 platform by Evolution Robotics (see Figure 2) for advanced undergraduate teaching, and a series of robotics projects throughout an MSc. course in three consecutive semesters. The former two have already been carried out or started, while the latter is in the phase of development. This will then serve as a first testbed to apply our Scalable Processing Box. Due to the SPB's platform independence, choices of platforms are the Evolution robot with the SPB, or a Pioneer robot (see Figure 3) which is currently used for PhD. research. However, any other available robot could be augmented with the SPB and used. The quality and properties of a robot platform determine International Conference on Engineering Education
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which concepts can be conveyed to the students. We classify the three platforms that we use into the following categories: 1. introductory level, schools (Lego) 2. undergraduate level (ER1) 3. advanced robots for research (Pioneer). Lego Mindstorms project The Lego project “Autonomous Service Robots” was carried out by a number of 5th semester student groups from the BSc. course "Applied Computer Science" as part of a hardware laboratory. It successfully completed in January. The project offered the largest number of places for a choice of projects within this lab. However, it was the first one to be filled, proving the popularity of the subject. The students had to solve a task using the Lego Mindstorms kit and were equipped with the LeJos Java environment. Within the groups, the students had to solve the task self-organized with little interference by the tutor. The project was carried out by 4 groups, all achieving the goal successfully. See Figure 4 for one of the robots. A video of the final presentation of the students can be found under www.learninglab.de/morob. This course was also used for initial evaluation (see the following section). Lab project for advanced undergraduate teaching A new lab project for advanced teaching has been developed and is carried out in the current summer semester (April-July). Here, students of Communication Science have to solve a localization task using information from the signal strength from Bluetooth access points. Application scenario is a "smart house" where users can communicate with appliances and mobile service robots from a PDA. For the robots, in order to navigate according to the user's requests, and to find out where the user is, localization has to take place to identify the positions. A number of undergraduate student teams are currently carrying out this project-based task as a lab session of their degree course. MSc. program with robotics projects A new MSc. program in Systems Design will start in autumn 2003 at Hanover University. This will incorporate a series of robotics projects as an essential part of the degree. It takes the concept of robots in a project-based scenario further than introductory courses, using it in far more sophisticated settings. Here, robotics will be integrated for motivation and as a core part for understanding systems analysis and design. MoRob concepts, in particular the Scalable Processing Box, allow carrying out such projects with a variety of platforms and tackling much more complex and complicated tasks than possible with Lego. The curriculum of this course requires the students to undertake a series of three projects, building on each other over the first three semesters of the course. They are undertaken in teams of 4 individual students. Project I has the task of analysis and modelling of a system. The students have to use Matlab/Simulink to create a simulation model of an existing system with all its software, electrical and mechanical components, with static and dynamic properties. Project II will take the students to the design phase. Here, the aim is to create a prototype as a virtual model, with the same tools from project I (Matlab). Finally, project III is concerned with integration. Here, no Matlab is used but the system will be implemented in the real world. This will focus on software development and electrical devices (sensors), considering the mechanical construction of the system. It has to be realized taking into account all concerns of the real world, including noise and real-time constraints. A key issue is the interaction between the different disciplines involved. The MSc. also offers an excellent testbed for pedagogical and didactic evaluation of our project: the building blocks and technology can be tested during a complete course sequence of four semesters.
EVALUATION OF EDUCATIONAL IMPACT A particular focus of our project is the evaluation of the learning process and educational impact: to provide information as to the suitability for engineering education concerning robotics and using our MoRob system. To achieve this, we will leverage a summative evaluation to determine program effectiveness. Evaluation of our concepts and the state of teaching with robotics will be carried out at all three partner institutions of MoRob. Our knowledge interests are: Does MoRob and projectbased learning improve student learning in robotics and other courses? Is our system useful to integrate research and scientific methods better and faster in teaching? What is the best way to supplement the project and problem-based learning by courses? To answer these questions, we plan comparative evaluation studies with students from the following control groups: BSc., MSc. and PhD. We want to evaluate the following elements of the learning process of the students: motivation, creativity, knowledge gains, theoretical concepts used, precision, quality of results, how do the students cope with technical challenges and how is their understanding and use of scientific and engineering methods. Evaluation testbeds will be the new MSc. Systems Design at Hanover, a new international MSc. Robotics at KTH and the Robotics Class 225 at Stanford. The main part of the evaluation of the MoRob system is scheduled for the 2nd project year. However, during this first year, a questionnaire will be used on existing courses at the three institutes to examine International Conference on Engineering Education
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aspects of the current state of robotics education. This can then be used for comparison, and initial results can be reflected in further developments of MoRob. The evaluation approach with an accompanying questionnaire has been designed in Hanover with the help of expertise from our experienced evaluation team. The same evaluation material will be used on three different courses at Hanover, Stanford and KTH, respectively, to acquire information about course contents and style across the three participating departments. It will be used on the following three classes: • Mini-Project "Mobile Service Robotics" in Hanover, February 2003 • Experimental Robotics class at Stanford, June 2003 • Autonomous Systems course at KTH, June 2003. For this first phase of evaluation within MoRob, the mini-project within our hardware lab was one of the courses to be looked at. The other two courses will take place in spring 2003, after which full analysis of results will be carried out. However, a few insights can be reported after a first look at this part of the evaluation with our Lego participants: within the problem-based learning task, students could bring in their own ideas to a large extent and had to acquire new knowledge on their own. The tutor only had to give little directions and students could organize their work freely. Teamwork and communication skills were felt to be among the most important things learned during this project. Many students felt that this was the best or most interesting project work they had ever done. Overall, the students judged the Lego platform and its environment as positive and appropriate. However, there were a large number of individual comments highlighting the shortcomings of this platform, for example: imprecise sensors, limited software, small memory, problems with multithreading and arithmetic. Students were highly motivated on this course and usually achieved more than was expected. For example, the quality of presentations was higher than expected, showing that the students put in a lot of effort to show their work. One group even had the first prototype ready from the time the kits were handed over until the first official group meeting, where the project was meant to be kicked off. Similar observations have been made in other Lego projects as well [e.g. 6].
CONCLUSIONS Robots are a perfectly suitable tool to support education in many different disciplines. They can be applied in teaching, demonstrating, exercises and lab classes and in research projects at universities. This paper presented the concepts of our MoRob project, which aims to provide the infrastructure and support the teaching efforts when using such tools. The Scalable Processing Box at the core of our system is a powerful and flexible processing platform for easy experimentation with any kind of robotic platform. It provides a framework for simple usage of standardized interfaces and algorithms when working with robots. The basic robot modules which we are developing are flexible and powerful enough to be used at all levels from introductory courses to advanced research projects. The benefits of our project are to supply an educational robotic platform, improve student learning especially in robotics, mechatronics, autonomous systems and computer science, increase the attractiveness of learning through facilitation of problem-based and experimental learning while performing student projects (learning by doing), and support teaching by reusable and sustaining material. The modular toolbox should also close the gap between research in robotics and current teaching. This will improve and increase the attractiveness of teaching because it will be much easier to integrate research results in education than it is possible today. Within the context of this project, robots are used in student projects. Lego Mindstorms has been successfully applied at introductory level, and insights from this are incorporated into a new Masters degree in Systems Design, using other, higherlevel platforms. The Lego project was also used to start initial evaluation of our project and the current state of our robotics teaching. This proved the benefits of robotics projects in teaching. Further and more extensive evaluation will take place during the next project phase. The different subjects involved in our design tasks clearly underline the interdisciplinarity of robotics. Our new system will not only allow for easy construction of robot systems and their use in robotics courses, it will also be applicable as a vehicle for experimentation in courses on other subjects like programming, signal processing, control theory and artificial intelligence. Therefore a standardized teaching environment will emerge which will be easy to use in a variety of applications.
ACKNOWLEDGEMENT This project has been supported with funding from the German Ministry of Research and Education (BMBF). We would also like to acknowledge cooperation from the Institute for Systems Engineering, University of Hanover.
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[10] O'Hara, K.J. and Kay, J.S. "Investigating Open Source Software and Educational Robotics". Consortium for Computing Sciences in Colleges Eastern Regional Conference 2002. Bloomsberg, PA. Also to appear in The Journal of Computing Sciences in Colleges. [11] Oppliger, D.E. "University- Pre College Interaction through FIRST Robotics Competition". International Conference on Engineering Education (ICEE'2001). Oslo/Bergen, Norway. [12] Orocos: Open Robot Control Software. http://www.orocos.org [13] Paul, C., Hafner, V. and Bongard, J.C. "Teaching New Artificial Intelligence using Constructionist Edutainment Robots". Workshop on Edutainment Robots 2000, Sankt Augustin, Germany. [14] RTAI: Real-Time Linux Application Interface for Linux. http://www.rtai.org [15] RTNet: Real-Time Networking for RTAI. http://www.rts.uni-hannover.de/rtnet/ [16] Wang, E.L. "Teaching Freshmen Design, Creativity, and Programming with Legos and Labview". Frontiers in Education Conference (FIE'2001). Reno, Nevada
FIGURES
FIGURE 1 ARCHITECTURE OF THE SCALABLE PROCESSING BOX.
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FIGURE 2 EVOLUTION ROBOTICS ER1 PLATFORM.
FIGURE 3 THE PIONEER 2AT MOBILE ROBOT.
FIGURE 4 FIRE-FIGHTING LEGO ROBOT BUILT BY STUDENTS.
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