Int'l Conf. Frontiers in Education: CS and CE | FECS'16 | 1 SESSION THE USE OF ROBOTS AND GAMIFICATION IN EDUCATION Chair(s) TBA ISBN: 1-60132-435-9, CSREA Press © 2 Int'l Conf. Frontiers in Education: CS and CE | FECS'16 | ISBN: 1-60132-435-9, CSREA Press © Int'l Conf. Frontiers in Education: CS and CE | FECS'16 | 3 An Evaluation of Simulation in Lego Mindstorms Robot Programming Coursework Frank Klassner1,2 and Sandra Kearney1,2 1Department of Computing Sciences, Villanova University, Villanova, PA USA 2Center of Excellence in Enterprise Technology, Villanova University, Villanova, PA USA Abstract – Robotics programming has become a significant Combining this observation with the research cited at the element of undergraduate computer science curricula over the beginning of the section, it is natural to ask what role past decade. This paper presents an initial examination of the simulation can play in conjunction with physical robots in effectiveness of simulators in helping undergraduates in computer science education, particularly in cases where computer science courses produce moderately debugged code students might be distracted from programming issues by on simulated robots before further refining it on physical “messy” robot interactions with the real world. There is also robots (Mindstorms NXT). The examination included a study the question of how to educate computer science majors about of how students evaluated their experience programming the industrial practice of using simulation to design and test robots in Java with and without a simulator in novice through robot systems before they are construed. advanced level courses. The paper describes the simulator for the study, the robot projects studied by the students, and This paper reports on a research project that evaluates the the survey instrument used in the examination. It concludes usefulness of simulation in conjunction with physical Lego with results on gender differences in student evaluation of the Mindstorms robotic programming exercises. To this end, it robot simulators, and overall student assessment of the first presents the simulator that was designed for the project simulator’s learning effectiveness. and then describes the Lego chassis and programming projects that were used in courses in the project. The paper then Keywords: Robot Simulation, Computer Science Education explains the survey by which students reported their 1 Introduction experiences while doing the projects with and without the robot simulator. The paper concludes with an analysis of the A rich long set of pedagogic research lines have shown that survey reports and discussion of future work. projects using physical robots such the Lego Mindstorms platform can be effective for grounding topics in computer science (CS) undergraduate courses such as CS0 [1, 2], CS 2 Robot Simulator 1/2 [3, 4], AI [5,6] and Operating Systems [7], and others outside CS. [8] The role of simulation in computer science The robotic simulation package used in the experiments is courses has also been explored since the first work on Karel called RAMS (Robot Analysis, Modeling, and Simulation). It the Robot [9] down to the recent Alice [10] investigations. was developed at Villanova to support various ready-made Several college and graduate-level robot simulation packages Lego Mindstorms chassis designs for students to test control have also been created over the last two decades, including software before trying the software on physical robots. Player/Stage/Gazebo [11] and Microsoft Robotics Studio. [12] 2.1 ROAMS – the Base for RAMS In a study conducted in this area by the first author [13], over 200 computer science majors were surveyed on their Jet Propulsion Labs staff used their Dshell software platform perception of 25 Lego Mindstorms laboratory modules’ for creating the ROAMS (ROver Analysis, Modeling and teaching efficacy in a variety of computer science courses. Simulation) simulator for modeling Mars robot rover One survey question in the study asked students across four missions. [14] ROAMS was designed to model a wide range types of CS courses whether a robot simulator would have of rover systems with an easy to use graphical user interface. made a significant difference in their programming ROAMS was designed to be a virtual rover that could be used experience. For those modules in which the environmental to test rover systems beyond just using the hardware alone. interaction of robot chassis design or control software design These needs require that ROAMS support a detailed physics played a significant role in the lab, student surveys indicated model of the rover platform along with the kinematics and that a simulation environment for the Mindstorms platform dynamics incorporated in it. ROAMS includes a suite of would likely have benefited them by (1) reducing their time sensors to get feedback information from wheels, steering spent verifying - and often rebuilding - their chassis and by (2) motors, encoders, cameras, light sensors etc. ROAMS increasing the time available for improving the performance included models for the environment with which the rover of their robots’ control software. will be interacting. The reliability of ROAMS is clearly demonstrated by NASA’s Mars Rover Program’s success. ISBN: 1-60132-435-9, CSREA Press © 4 Int'l Conf. Frontiers in Education: CS and CE | FECS'16 | ROAMS and Dshell have been released to the public research sector under the caveat that users must demonstrate evidence of US citizenship or permanent residence. The ROAMS platform was selected as the base from which to build the RAMS simulator used in this research project, since it included a powerful physics engine that could be adapted for undergraduate use in computer science curriculum. Although ROAMS presented a complex interface, we did not want to start with a less robust platform only to run the risk later of discovering that students’ simulator experience was not close enough to “real-world physics.” We felt it would be easier in our experiments to simplify ROAMS modeling or its interface when needed than to build up another simulator Figure 2. RAMS Client Window. package’s physics engine on our own. Students controlled the simulation by clicking on a start/stop 2.2 RAMS Design button on the Client window. Data logs for each of the robot features could also be generated. The PlanView window was Java is the primary programming language in the Villanova configured to track automatically the motion of the robot, but computer science curriculum, and the Lego Mindstorms robot its perspective of the robot could be manually adjusted during platform coupled with the Java-based LeJOS library [15] is a simulation. As shown in the PlanView window, the one that has been most commonly used in computer environmental elements such as chairs, floors, and desks science courses at Villanova. To facilitate comparisons could be included in the simulation to aid in students’ between student programming experiences with and without understanding of how to program their robots for the room in the simulator, the RAMS system was designed with a which they were working. compiler that could retarget the same LeJOS code to a physical or to a simulated robot at the click of a button, The research project was conducted using the RAMS with without requiring students to rewrite any code when simulator models based on the NXT Mindstorms platform, switching between physical and simulated platforms. but with minor modifications the RAMS simulator can use the LeJOS libraries for the current EV3 Mindstorms platform. The RAMS interface developed as a modified interface for the ROAMS platform has three windows: an Eclipse editor window for editing and compiling lab module code, a 2.3 Robot Chassis Designs simulator PlanView window for observing a simulated robot To make it feasible for students to conduct the robot performing in real time under the control of student code, and laboratory projects as closed lab experiences, the lab modules a RAMS Client window for showing real time state changes in this research were based on chassis that would be already in the sensors, LCD display and motors of the robots. RAMS constructed for the students. In this way students had the is executed within a Fedora shell. Figures 1 and 2, maximum in-class time available for programming and testing respectively, show the PlanView and Client windows. The their control software. Two robot chassis designs were RAMS Client window as illustrated shows all the features developed and modeled using the Spatial Operator Algebra that are possible to display, but it can be configured (by an modeling language of ROAMS. The simulator’s underlying instructor, for example) to show only those features of a robot ROAMS architecture permits suitably-trained instructors to that are germane to a given laboratory project. define and add new robot models to the list of available models. Figure 1. RAMS PlanView Window Figure 3. Tribot Figure 4. Spiderbot ISBN: 1-60132-435-9, CSREA Press © Int'l Conf. Frontiers in Education: CS and CE | FECS'16 | 5 The Tribot shown in Figure 3 is a three-wheeled robot that is The courses required a broad range of knowledge and based on the same-named model in the NXT Construction experience, from students with no programming language Manual that comes with Mindstorms NXT kits. Note that the knowledge or experience to students with more than five sonar sensor in shown as the “head” of the robot was not used computer programming languages and in-depth in the lab modules described later in the next section. This understanding of computer science. The students in these chassis was selected for use in the experiment due to its computer science courses had three basic levels of straightforward design. Students could use the LCD for programming experience: Novice, Intermediate, and debugging messages. Advanced. The spiderbot shown in Figure 4 is a six-legged robot that was 3.2 Robot Projects designed based on the Strider robot presented in Valk’s NXT development book.