2015 American Control Conference Palmer House Hilton July 1-3, 2015. Chicago, IL, USA
GUPPIE, Underwater 3D Printed Robot a Game Changer in Control Design Education Saeedeh Ziaeefard, Guilherme Aramizo Ribeiro, and Nina Mahmoudian
Abstract— This paper presents innovative strategies to teach control and robotic concepts. These strategies include: 1) a real world focus on social/environmental contexts that are meaningful and “make a difference”; 2) continuous design potential and engagement through use of a platform that integrates design with engineering; 3) mission-based versus application-based approaches, where meaningful application justifies the process; and 4) hands-on, inquiry-based problem-solving. For this purpose a Glider for Underwater Problem-solving and Promotion of Interest in Engineering or “GUPPIE” platform and its simulator were utilized. GUPPIE is easy and inexpensive to manufacture, with readily available lightweight and durable components. It is also modular to accommodate a variety of learning activities. This paper describes how GUPPIE and its interdisciplinary nature was used as a pedagogical platform for teaching core control concepts for different age groups. The activities are designed to attract the interest of students as early as middle school and sustain their interest through college. The game changing aspect of this approach is scaffolded learning and the fact that the students will work with the same platform while progressing through the concepts.
INTRODUCTION Robotic platforms have proven to be a successful way to engage and keep student interest in STEM [1]–[10]. Based on constructivist theories [11], the effectiveness of this type of project design comes from engaging students in the design and development of products they can then use in meaningful ways. However, many current robotic programs are missionbased, rather than application-based, which may explain the higher percentage of male interest, since female students are often less inclined to be motivated by competitive, missionbased approaches [12], [13]. Especially for those female students who have a well-developed interest in science and engineering, there needs to be a meaningful context for nurturing that interest into sustained motivation for exploring career paths, especially in a male-dominated field like mechanical engineering [14]. In 2012, just 18.9% of engineering degrees were awarded to women [15]. Mechanical engineering has only 12.4% of degrees going to women (only computer engineering has a lower percentage). As Busch-Vishniac and Jarosz [16] point out, efforts to increase Research partially supported by National Science Foundation under grant NSF-1426989 and Office of Naval Research under grant No. N00014-141-0032. S. Ziaeefard (
[email protected]) and G. Aramizo Ribeiro (
[email protected]) are graduate research assistants and N. Mahmoudian (
[email protected]) is an assistant professor in the Department of Mechanical Engineering-Engineering Mechanics, Michigan Technological University, Houghton, MI 49931, USA.
978-1-4799-8684-2/$31.00 ©2015 AACC
Fig. 1.
SYP scholar testing GUPPIE in the swimming pool
diversity tend to focus on symptoms rather than making the profession more appealing. They argue that, rather than offering more scholarships and outreach programs, educators need to revamp the undergraduate engineering curriculum. The Nonlinear and Autonomous Systems (NAS) Lab Glider for Underwater Problem-solving and Promotion of Interest in Engineering or GUPPIE platform (Fig 1) is being used at Michigan Tech to revamp the undergraduate engineering curriculum, focusing on the design process and making explicit connections to meaningful applications, such as sustaining the Great Lakes through observation and data collection. This work builds a socially constructed message aimed at positively influencing early perceptions about what an engineer does in the real world [17], [18]. Too often students’ pre-conceived notions lead to self-selection out of the STEM opportunities available to them. This is especially true in the mechanical engineering field. Pre-existing attitudes and ambivalence toward the field greatly limit participation of students who would most benefit from the intellectual flexibility and hands-on learning activities engineering programs offer [18], [19]. While mechanical engineering is often related to cars, motors, robotics and competitions, it is less often taught from the perspective of marine monitoring and autonomous underwater vehicles. Through GUPPIE, a water vehicle platform, students will explicitly understand the relationship between biodiversity, ecology, environmental science, and marine sustainability problems and the role engineering plays to facilitate sustainable solutions. Moreover, the GUPPIE platform takes an application approach
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Fig. 3.
Fig. 2.
3D printed GUPPIE
GUPPIE 3D printed design
using meaningful themes that tap both right and left brain thinking, encourage social interactions with team partners, and make explicit connections between engineering core concepts and the skills needed to solve social, environmental and health related problems. The GUPPIE platform has been successfully tested with different age groups and diverse under represented populations in collaboration with Western Upper Peninsula Center for Science, Mathematics, and Environmental Education (WUPC) and Michigan Techs Center for Pre-College Outreach. The team also prepared two YouTube videos to introduce the GUPPIE platform to a larger audience outside of the local area. One describes the operation and design of the GUPPIE in detail for lay audiences and has had more than 17,000 views. The other video explains the mechatronics and programming and has received more than 7,600 views. This paper presents our efforts on optimizing the GUPPIE design in section I. Section II describes the GUPPIE simulator developed utilizing Sim-Mechanic, a powerful package of the Simulink. Sections III and IV show how we have utilized, the GUPPIE platform to introduce and teach fundamental control concepts for different age groups. We are taking a design-oriented teaching approach. From the theoretical knowledge to practical hands-on experience, it will be a level-based learning that can start as early as middle school and can continue as late as graduate school. The teaching material is tailored to the age group and based on the background of the students. The game-changing aspect of this approach is that the students will work with the same platform while progressing through the concepts. I. GUPPIE D ESIGN O PTIMIZATION FOR T EACHING STEM C ONCEPTS The GUPPIE prototype is small (60cm long), weights 4.15kg including 1kg payload, has 30 minutes hours endurance, reaches depth of 3 meters [20], [21]. From preliminary development work and outreach experience (described in [21]), we learned that the GUPPIE manufacturing and
Fig. 4.
GUPPIE simulator
assembly process was too time consuming because of the structural components that need to be machined. For example, the seven mounts required 80 hours of student machining time. Therefore, we incorporated 3D printing technology. The use of the 3D printers is becoming increasingly popular in schools across the country. 3D printing has brought new meaning to hands-on learning and will be adopted in K-12 education in five years. The application of the 3D printers in classrooms will go far beyond rapid prototyping of visual aids for science and history classes. 3D printers can be used to teach innovative design thinking process in classes through experimentation, innovation, play, and problem solving. The 3D printing process fascinates students and allows them to create something based on their own imagination, increasing learning outcomes. Studies have shown, that in middle school, infusion of engineering design in teaching has a positive impact on student attitude toward mathematics, and improves their mathematical knowledge. Building on the success of previous work, instead of relying on a platform that requires machining, we redesigned the platform so that all the mounts and structural components that are not available off the shelf are 3D printed (Fig 2 and Fig 3). This cuts manufacturing time down to less than 12 hours. The 3D printed GUPPIE is lightweight (3.5kg) and reaches deepest end of the swimming pool dive tank (4m) and has endurance of 2 hours. The flexibility that 3D printing brings to this new platform maximizes students potential as designers. Through this process, participants will practice iterative design and learn critical thinking skills. With GUPPIE, students will learn how to apply science concepts to a real machine that conducts missions to achieve student goals. They will engage in engineering activities such as conceptual design, data interpretation, sketching part designs,
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Fig. 5.
Level-1 GUPPIE simulator
modeling parts with design software, and realizing parts with 3D printing. Students will learn how advances in technology will influence design, programming, and data processing. GUPPIE will help teachers to exploit the natural connection between engineering and the other STEM subjects and fill the existing gap in engineering in K-12 education, as reported by the National Academy of Engineering. In addition, we have developed a 3D multibody simulation model “GUPPIE Simulator” from which students can learn about internal mechanisms and the effects of different modifications on the functions of the system. II. GUPPIE S IMULATOR To encourage computer-aided control design and learning, we have developed a simulator using Simulink and its packages. This will keep the hands-on experience and control design implementation process united with the course material as the students use the same software throughout the whole course. To develop the GUPPIE simulator, we first imported the GUPPIE Solid Works model into Simulink. The Simulink converted the model into joint, frame and transforms, constraint, body elements and gear, coupling, and drivers using the predefined blocks in Sim-Mechanic package under the Sim-Scape library. Next, we modified and organized the elements according to the dynamics of the GUPPIE and added the force and torque block. SimMechanic solved the equation of motion for the system based on the initial condition and implemented data. This 3D multibody simulation model will help students learn about internal mechanisms and the effects of different modifications on the functions of the system. The students are able to observe, analyze and evaluate the GUPPIEs response to any systematic changes. These adjustments can be from changing the wing position, which affects the hydrodynamic
response of the glider to changes in the parameters of the controller, which affects the trajectory and stability of GUPPIE. Utilizing the GUPPIE simulator, different aspects of the control course material will be covered. Currently we utilize two versions of the simulator for different levels of teaching. The level-1 GUPPIE simulator is designed for the middle school to early college level and focuses on the overall simulation of the glider. The level-2 GUPPIE simulator is developed for undergraduate students for control system design evaluation. Fig 5 depicts the level-1 GUPPIE Simulator, which by changing the parameter in the underwater gliding block, the trajectory of the glider can be observed through the simulator scope. In this simulator, we modeled the coupled buoyancy mass system by a linear mass to demonstrate the concept of controlling GUPPIE’s flight path angle and depth in water. Altering the amplitude and frequency of the input signal of the actuator controls the linear mass speed and position. This simulates the changes in the vehicle’s buoyancy mass through the position of the syringe head in the design. This simulator has a Graphical User Interface (GUI) that is used to change the value of different parameters. Fig 4 depicts the schematic of the GUPPIE simulator. The level-2 GUPPIE simulator is designed for undergraduate students (Fig 6). This simulator is more sophisticated and is appropriate for students that learned simulation in the previous level. This simulator will provide the opportunity to evaluate their control system design before the actual water test. The level-2 GUPPIE simulator that will be utilized in control and robotic classes consists of three main sections: water interaction block, trimming block, and GUPPIE block. Fig 7 illustrates the main blocks of the GUPPIE simulator. Water interaction block includes hull buoyancy, ballast buoyancy, water viscosity, and hydrodynamics. It is a user-
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Fig. 6.
Fig. 7.
Level-2 GUPPIE simulator
GUPPIE simulator main blocks
defined MATLAB function that easily can be modified. Trimming block uses readily available inertia block and gives the appropriate mass placement in cylindrical coordinate to trim the vehicle. The trimming block receives the desired pitch angle, position of linear mass, and buoyancy mass and, through internal interaction with water interaction block, calculates the appropriate trim mass and position. The GUPPIE block receives the calculated forces and torques on the body from water interaction block and initial ballast as input. The outputs are the state of the GUPPIE including position, velocity, orientation, angular rates, and ballast mass. The initial ballast mass is calculated by measuring syringe head position by a sensor. This input is integrated with a saturation block, hence there is no solid overrun. Simulating the PID controller and evaluating its effect on improving the gliding trajectory is the main goal of this simulator.
III. P RE - COLLEGE L EVEL I NSTRUCTION Research shows that for pre-college students, experiences that make sense in their everyday lives are the most influential factor in the development of their education and career trajectories. Moreover, hands-on activities that relate to students’ local communities and/or environments make of an impression. By focusing on the meaningful rather than the competitive nature of robotics, we expect to increase girls interest in engineering. Students can use GUPPIE to measure water quality, observe marine biodiversity, inspect underwater structures, and help control invasive species such as Asian Carp. While using GUPPIE students learn about underwater gliders, which are a special form of Autonomous Underwater Vehicles (AUVs). They learn that underwater gliders play an important role in solving some of today’s most pressing environmental, safety, and biological
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Fig. 8.
GUPPIE control loop
system in Simulink and observing the model behavior was part of the activities for this age group. As described in section II, Level-1 GUPPIE simulator is developed for this age group (Fig 5). Students can use the mouse to change the position of the wing as well as the position of the trimming weight. Changing the position of the wing will teach students about the effect of hydrodynamic forces and the effect of the lift moment on the vehicle pitch behaviour. Changing the trimming weight changes the net weight of the GUPPIE and it makes it positive or negative buoyant. This activity teaches the students about vehicle and water interaction. Students learn about the forces coupling effect when they try to balance the vehicle through wing and trimming weight position. IV. U NDERGRADUATE L EVEL I NSTRUCTION Fig. 9.
Basic level GUPPIE circuit scheme
challenges. Commercial underwater gliders have been used for long-term, basin-scale oceanographic sampling for the purpose of predicting climate change patterns and measuring dangerous containments such as oil spills. Our developed activities encourages design with purpose. The students will learn the engineering design process and practice it to design a part for GUPPIE to accomplish a specific task or make a modification that will result into certain outcome. This approach is the same approach that real-world engineers employ. In Summer of 2014, GUPPIE was used as group project platform for Summer Youth Program (SYP) (Fig 1). The GUPPIE experience was offered in two levels of middle and high school considering the students’ backgrounds. Students learned programming with Arduino (day 1 and 2), designed a mount for a GoPro camera (day 3); fabricated their group design with a 3D printer (day 3-4); assembled GUPPIE (day 4) and deployed GUPPIE with their GoPro mount in an underwater environment (day 5). For middle school students, we started with basic knowledge about programming and robotic topics. We taught them how to program microprocessors like Arduino uno and familiarized them with the basics of controllers. In addition, integration of actuators and sensors was taught to high school students. Simulating the simplified dynamic
For an undergraduate control course taught at Michigan Tech (MEEM 4700), after learning control concept and simulation, students can design their own control system for GUPPIE. The control system of GUPPIE can be as simple as a bang-bang controller or as sophisticated as a feedback controller integrated with different sensors (Fig 8). Throughout the course students will learn how to develop the dynamic system equation of a known system, interpret the system in the Simulink using block diagram and finally evaluate the output of the system. While mastering their ability to understand the control concept, they can eventually start designing their own controller based on the theory and the simulation experience. The students first design the circuitry of the robot (Fig 9), programm the microprocessor and bench test the mechanical component. Then they design a controller and implement it on the simulator and test the behavior. Next, they implement the controller on the pre-made GUPPIE platform (Fig 3) and evaluate the vehicle behavior and control system performance in the swimming pool. At this stage, students will learn about trimming phenomenon in gliders to prepare the glider for its mission. The students will use the level2 simulator (Fig 6) to tweak the controller parameter to obtain optimized kp , ki , and kd for their controller.The PID controller calculates the final output of trimming block as GUPPIE’s initial flight condition.After tuning the parameters and plugging them into the MATLAB function in water interaction block, students evaluate GUPPIEs behavior in a
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simulated underwater environment to reach to the desired saw-tooth motion. Students can model any data acquiring sensors such as CTD (Conductivity, Temperature, and Depth) sensor and model it into the system and observe the outputs. Besides teaching the control concepts, one of our concerns is to teach students how to approach a control problem in real-life. Critical thinking and problem solving are the most essential skills that every engineer needs. Students will be assigned different assignments and tasks to accomplish. The students can design 3D printed parts, choose the actuators, pumps, mechanical/electrical valves, electrical sensors, and other electrical components based on the requirements of the system. The flexibility that 3D printing brings to this platform maximizes students potential as designers. Through this process, students will practice iterative design and learn critical thinking skills. This pathway will allow GUPPIE students to take on more complicated missions as they progress in competency, motivation and persistence. In this class, undergraduate students can develop their own simulator as part of their course project. They can model their robot in any CAD software and convert it to Sim-Mechanic. They also can modify GUPPIE block and trimming Block on their own, perform system identification to test their water interaction model. Students can add any data acquiring sensors such as CTD sensor and model it into the system and observe the outputs. V. F UTURE W ORK In summary, this paper introduces the GUPPIE platform as an innovative control design teaching platform to and through college. The authors believe that GUPPIE provides interdisciplinary training opportunities for hands-on learning of controls and robotics concepts. GUPPIEs modular platform is designed to have components constantly added or modified to facilitate learning of a broad array of concepts to engage participants of all ages in problem-solving and design skills, and data collection and testing application. The application-based nature of the GUPPIE platform, and handson activities in diverse areas from hardware development, and programming to gathering and interpreting data will improve students ability for critical, creative problem solving, and ultimately increase individual motivation for learning more advanced control concepts. The NAS Lab design team, which includes undergraduate and graduate students, will implement the engineering design process and investigate alternative solutions, develop prototype, test and evaluate, and redesign to reach an optimal GUPPIE design. The optimization aim is to design and manufacture a highly maneuverable low-cost ($1000 or less), lightweight (3.5kg), and small (60cm long) GUPPIE for shallow water (10m depth) long endurance (8 hours) exploration. Unlike the previous GUPPIE platforms, which only had capability of forward up and down movement, the new platform will have the potential to perform circular paths. This pathway will allow GUPPIE students to take on
more complicated tasks and advanced applications as they progress in competency and become more motivated. R EFERENCES [1] M. Veltman, V. DAVIDSON, and B. DEYELL, “Richer connections to robotics through project personalization,” Advances in Engineering Education, vol. 3, no. 2, 2012. [2] D. Chubin, K. Donaldson, B. Olds, and L. Fleming, “Educating generation netcan us engineering woo and win the competition for talent?,” Journal of Engineering Education, vol. 97, no. 3, pp. 245– 257, 2008. [3] F. Basoeki, F. D. Libera, E. Menegatti, and M. Moro, “Robots in education: New trends and challenges from the japanese market,” Themes in Science and Technology Education, vol. 6, no. 1, pp. pp51– 62, 2013. [4] M. N. Lego Education, “How to use robot in education.” https://education.lego.com/enus/lesi?domainredir=www.legoeducation.us. [5] D. Alimisis, “Educational robotics: Open questions and new challenges,” Themes in Science and Technology Education, vol. 6, no. 1, pp. pp63–71, 2013. [6] Robotis, “Ollo is science.” http://www.robotis.com/xe/ollo. [7] Fischertechnik, “History.” http://www.fischertechnik.de/en/Home/info/. [8] Robotis, “Do-it-yourself educational robot kit.” http://www.robotis.com/xe/bioloid. [9] Vstone. http://www.vstone.co.jp/english/index.html. [10] T. Robot, “Thymo ii.” https://aseba.wikidot.com/en:thymio. [11] D. Alimisis, M. Moro, J. Arlegui, A. Pina, S. Frangou, and K. Papanikolaou, “Robotics and constructivism in education: The terecop project,” EuroLogo, vol. 40, pp. 19–24, 2007. [12] S. Tavrou, C. Thong, C. Steele, et al., “Increased female participation into engineering education through specialised courses,” 2011. [13] H. M. Matusovich, R. A. Streveler, and R. L. Miller, “Why do students choose engineering? a qualitative, longitudinal investigation of students’ motivational values,” Journal of Engineering Education, vol. 99, no. 4, pp. 289–303, 2010. [14] B. L. Yoder, “Engineering by the numbers,” American Society for Engineering Education, Washington, DC. http://www. asee. org/papers-and-publications/publications/collegeprofiles/2011-profileengineering-statistics. pdf, 2012. [15] I. J. Busch-Vishniac and J. P. Jarosz, “Can diversity in the undergraduate engineering population be enhanced through curricular change?,” Journal of Women and Minorities in Science and Engineering, vol. 10, no. 3, 2004. [16] N. Mattern and C. Schau, “Gender differences in science attitudeachievement relationships over time among white middle-school students,” Journal of Research in Science Teaching, vol. 39, no. 4, pp. 324–340, 2002. [17] B. Bevan and R. J. Semper, “Mapping informal science institutions onto the science education landscape,” Center for Informal Learning and Schools. Retrieved from http://cils. exploratorium. edu/resource shared/downloads/4229/Mapping% 20Informal% 20Science% 20Instituions% 20onto% 20the% 20Science% 20Eductaion% 20Landscape. pdf, 2006. [18] M. G. Lynch, “Educating america’s talent in science, technology, engineering, and mathematics: an analysis of the effects of parental and high school factors on females’ and males’ decisions to enter stem fields of study,” 2009. [19] J. Legewie and T. A. DiPrete, “High school environments, stem orientations, and the gender gap in science and engineering degrees,” STEM Orientations, and the Gender Gap in Science and Engineering Degrees (February 21, 2012), 2012. [20] B. Mitchell, E. Wilkening, and N. Mahmoudian, “Developing an underwater glider for educational purposes,” in 2013 IEEE International Conference on Robotics and Automation (ICRA), pp. 3423–3428, IEEE, 2013. [21] B. Mitchell, E. Wilkening, and N. Mahmoudian, “Low cost underwater gliders for littoral marine research,” in American Control Conference (ACC), 2013, pp. 1412–1417, IEEE, 2013.
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