An Affordable Modular Robotic Kit for Integrated Science, Technology, Engineering, and Math Education
© PHOTOCREDIT
By ekawahyu Susilo, jianing Liu, Yasmin Alvarado Rayo, Ashley Melissa Peck, Pietro Valdastri, justin Montenegro, and Mark Gonyea
he demand for graduates in science, technology, Fischertechnik [6], are composed of libraries of engineering, and math (STEM) has steadily prefabricated parts that are not interoperable among kits increased in recent decades. In the United from different vendors. As recently surveyed in Kee [7], States alone, jobs for biomedical engineers are alternatives to these popular kits are either highly modular expected to increase by 62% by 2020, and jobs but very expensive (e.g., Kondo [8], Bioloid [9], Cubelets Tin software development and medical science are [10], K-Junior V2, and Kephera [11]) and unaffordable for expected to increase by 32% and 36%, respectively [1]. the majority of schools, or single-configuration and low- Combined with an insufficient number of students cost robots (e.g., AERObot [12], iRobot [13], and Boe-Bot enrolled in STEM fields, this will result in about 2.4 [14]) with a restricted number of activities possible. An million STEM job vacancies by 2018 [2]. Therefore, affordable solution that provides a number of increasing the number of STEM graduates is currently a interchangeable modules is littleBits [15]. This platform national priority for many IEEEgovernments worldwide. An offersProof a variety of sensing and actuation modules that use effective way to engage young minds in STEM disciplines is magnets to connect, but it lacks programmability, thus to introduce robotic kits into primary and secondary limiting students’ ability to learn about coding. education [3]. The most widely used robotic kits, such as In this article, we introduce the educational STORM- LEGO Mindstorm [4], VEX Robotics [5], and Lab Modular Architecture for Capsules (eSMAC) robotic kit, a low-cost and interoperable robotic kit with a variety
Digital Object Identifier 10.1109/MRA.2016.2546703 of functional modules that can be easily connected Date of publication: xxxxxxx together with a snap-on three-wire magnetic connection.
2 • Ieee ROBOTICS & AuTOMATIOn MAGAZIne • june 2016 1070-9932/16©2016Ieee eSMAC robots have a 40-mm diameter cylindrical foot- to a disparaging chasm of equality between schools that print, with functional modules that can be stacked on top have adequate funds and those that do not. Vernier mar- of one another. The available modules include actuation, kets digital classroom measuring devices [19] that work sensing, wireless communication, programmable units, well and are durable. For a physics lesson involving kine- and audio/visual indicators. The robots can be pro- matics, Vernier’s Go!Motion measures and displays posi- grammed through a web-based user interface installed tion, velocity, and acceleration to a high degree of accuracy either as a plugin or an app on the Google Chrome and precision. The cost of one motion detector and its req- browser. At the time of publication, eSMAC robots have uisite software, however, exceeds US$350. For a school to been applied to different educational activities, ranging stock a single science classroom with ample motion detec- from a robot soccer game to maze exploration. These tors for a class of 25 students to have enough to use in activities can be integrated in core subjects of STEM cur- groups, the school would need to spend around US$2,000. ricula, such as physics, computer science, engineering, This is a prohibitive amount for U.S. urban or rural public and math. The eSMAC robotic kit is the educational ver- schools, as well as for the average suburban private school, sion of the SMAC design environment [16], [17] that especially given the fact that nowadays school teachers are aims to reduce the barriers for design space exploration spending an average of US$500 of their own money on in the field of medical capsule robots by providing an classroom supplies [20]. open source library of hardware and software functional Most STEM teaching and learning in K–12 grades in modules. the United States has focused on science and mathematics but very little on technology and engineering. Even in Role of Robotic Kits in Next-Generation schools that teach all four subjects, all are taught as sepa- Science Standards rate subjects instead of as an integrated curriculum. This Here, we focus on the recent reform of STEM education in situation will eventually change with new reforms in teach- the United States that is occurring with the introduction of ing and learning methods, placing more connection next-generation science standards (NGSS) [18] and on the among STEM disciplines. In April of 2013, the National role that robotic kits may play in this new framework. This Research Council, the National Science Teachers Associa- shift in paradigm for education is specific to the United tion, the American Association for the Advancement of States, but the same underlying concepts apply to STEM Science, and Achieve released the NGSS for adoption by education around the world. In the real-world application, state boards of education. In an explicit shift to ensure that science relies on technology, mathematics, and engineering. students know how to accomplish science, the NGSS out- Engineering itself depends on findings from science and line performance expectations that state how students can applications of mathematics. Textbooks and lectures are demonstrate their mastery of a standard. These perfor- important for teaching, but adding hands-on connected mance expectations are based on the science and engineer- learning may improve understanding of the basic concepts ing practices associated with the disciplinary core ideas and, ultimately, engage more students. tied to each standard. Furthermore, the performance The quality of STEM education in the United States has expectations are linked to other standards found in com- been an ongoing point of concern for policymakers and mon state standards for mathematics and language arts. educators since the 1957 launch of the Soviet satellite The intent of the NGSS is that students must be able to Sputnik. Ever since then, there has been a consistent push participate in the process of exploration and investigation to ensure that students graduate prepared to join and lead that underlies science and connect the concepts they inter- jobs in scientific and technological research and innova- nalize to material learned in other disciplines. Students tion. Beginning in the 1990s, coordinated efforts by the need a platform to link learning across a variety of curricu- National Science Foundation (NSF), other research-orient- la that allows them to participate in the discovery process. ed groups, and teacher educators led to the piecemeal Just as with prior attempts at making science education adoption of science standards that emphasize doing science more hands on and exploratory, the NGSS require the using rote memorization of facts. Teachers were encour- proper tools to allow students to engage with their envi- aged to make lessons inquiry based and hands on rather ronment in a process of discovery and refinement. To than rely on textbooks and direct instruction. ensure that these tools can reach even the most under- The tools for implementing this type of instruction funded systems, schools, and classrooms, the tools must have lagged behind calls for IEEEbetter instruction. Depending be inexpensiveProof (i.e., from US$100 to US$200 for a class of on the age and financial resources of students and the 25 students) and serve multiple purposes. A robotic kit school, science materials range from simple boxed kits that provides the means by which students can control and allow students to verify known phenomena to sensitive engage their environment on their terms. A modular measuring devices that work as part of a larger teacher- or robotic kit provides a base that can be connected to a vari- student-constructed investigation. Unfortunately, the tools ety of sensors, actuators, and probes to make that engage- that allow student-driven inquiry tend to come at a much ment of the environment robust. Students can determine higher price than the heavily directed lab in a box, leading those modules that are most appropriate for their investi-
june 2016 • IEEE ROBOTICS & AUTOMATION MAGAZINE • 3 The eSMAC Modular Robotic Kit
eSMAC Snap-On Modules The eSMAC robotic kit has been designed to achieve ease of use, modularity, interoperability, and low cost. Each (a) (b) (c) (d) module implements a different function and can be con- nected to other modules with the use of three magnetic contacts for synchronization, communication, and power delivery. A programmable microcontroller is integrated in each module to implement the communication protocol (e) (f) (g) (h) and user commands specifically related to the module function. Figure 1. A selection of eSMAC functional modules. (a) The output module can be used to drive motors, relays, or buzzers to In terms of functionality, eSMAC modules can be classi- generate sound; (b) communication module implements BLE; fied as follows: (c) powering module with a lithium ion polymer battery and an ●● input: analog or digital inputs with sensing capabilities onboard charger; (d) powering module with a rechargeable coin cell slot; (e) module embedding multiple functionalities (BLE, IMU, (e.g., temperature, humidity, pressure, push button) barometer, and motor driver, all powered by a rechargeable battery ●● output: analog or digital outputs with indicators (e.g., on the backside); (f) input module with an IMU; (g) input module light, sound indicators) with a barometer; and (h) mobility module with two independent brushed motors connected to rubber wheels.
4 • IEEE ROBOTICS & AUTOMATION MAGAZINE • june 2016 Module Connectivity and Safety Each module is designed and built on a fully assembled printed circuit board (PCB) with three magnetic contacts embedded in the PCB. For module interconnection safety, those three magnetic contacts are placed at positions of 90 degrees (S–N polarity for data communication point), 225°, and 315 degrees (dual N–S polarities for powering points) around the circular PCB, as shown in Figure 3(a). With this magnet polarity placement, snapping modules together can only be done in one way, leaving no room for errors. The dual N–S polarities for power include a resettable fuse and reverse polarity protection. Users do not need to worry about placing the battery in the wrong way, because issues Figure 2. A two-wheel mobile robot composed of powering, arising from reverse polarity are checked by a bridge rectifi- communication, mobility, and two input (barometer and IMU) er built into every module. Battery module placement can modules next to a table-tennis ball (diameter 40 mm) for a be flipped, and the rest of modules can still maintain steady size reference.
june 2016 • IEEE ROBOTICS & AUTOMATION MAGAZINE • 5 Anaren Atmosphere Developer (https://atmosphere. anaren.com) was used to create and design a mobile appli- cation that connects with the Bluetooth low-energy (BLE) module on the robot. This online development environ- ment provides a user-friendly platform to quickly create smartphone applications in which the app and firmware for the chip are developed simultaneously. The developer pro- vides the combination of a graphical user interface along with C and JavaScript coding that is easy to use and main- tains a wide range of functionalities. Another benefit of the Atmosphere Developer is compatibility with many different Figure 4. A screenshot from the SMAC-IRP programming platforms. Because the development environment is online, environment, with the terminal in the left panel and Google this allows access to the same documents from any PC, Blockly in the right panel.
Bluetooth Communication Cost Breakdown Once JSON communication and data synchronization are A low-cost and flexible toolkit can help to provide an afford- set up, a Bluetooth mobile application can be used to control able STEM education for middle and high school students. the functionalities of eSMAC robots. Bluetooth has many One advantage of the eSMAC toolkit over similar robotic kits advantages for the eSMAC platform, including low energy is its fairly low cost. For estimation purposes, we give a rough and a reliable and private connection over large distances. cost breakdown in Table 1 of different modules and hardware Because most smartphones and tablets today are equipped parts of the eSMAC kit, based on a manufacture environment with Bluetooth compatibility, this provides great flexibility outside of a university research lab. The total estimated cost of for devices that can be used toIEEE control the modules. an eSMACProof toolkit is less than US $150, an affordable amount
Table 1. Cost breakdown for the eSMAC toolkit. Robot base IMU Barometer BLE module Battery Charger Buzzer LED Total
Estimated 30 10 15 30 5 5 15 10 120 Cost ($US)
6 • IEEE ROBOTICS & AUTOMATION MAGAZINE • june 2016 for average public schools given current budgets [20]. In addi- tion, the toolkit does not need to be purchased as a whole: Teachers can buy only those parts or modules that they need and avoid unnecessary expenses for irrelevant parts.
Application Examples With the support of versatile software architecture and flex- ible hardware configurations, eSMAC robots have so far been implemented in a variety of hands-on applications fit- ting different STEM curricula.
Robot Soccer Game
One possible application of the eSMAC robotic kit is Figure 5. Four eSMAC robots playing two-on-two robot soccer robot soccer. Multiple users each control their own robot with a table-tennis ball.
Smartphone 1 Smartphone 2 Smartphone 3 Smartphone 4
JSON Command JSON Command JSON Command JSON Command (Bluetooth) (Bluetooth) (Bluetooth) (Bluetooth)
eSMAC Robot 1 eSMAC Robot 2 eSMAC Robot 3 eSMAC Robot 4
Bluetooth Module Bluetooth Module Bluetooth Module Bluetooth Module
JSON Command JSON Command JSON Command JSON Command (RF Channel 12) (RF Channel 14) (RF Channel 16) (RF Channel 18) Base Module Base Module Base Module Base Module (Control Motion) (Control Motion) (Control Motion) (Control Motion) Battery Module IEEEBattery Module BatteryProof Module Battery Module
Figure 6. A diagram of modules used to implement 2-on-2 robot soccer.
june 2016 • IEEE ROBOTICS & AUTOMATION MAGAZINE • 7 and subclasses. This example illustrates an opportunity Multifunctional Module for Experiments for a teacher to model, in a tangible manner, an abstract in Dynamics concept such as class creation of object-oriented program- The multifunctional module represented in Figure 1(e), ming. The cost of materials to create the mini-soccer game which includes a barometer, an IMU, BLE connectivity, field is approximately US$10 (two 20×30-in foam boards, and a coin cell rechargeable battery, can be inserted into a box cutter, glue, and table-tennis ball), and a single modu- tennis ball or tied onto a water bottle rocket to measure lar soccer player costs about US$70 (robot base, BLE mod- acceleration, orientation, and altitude. Data can be trans- ule, rechargeable battery module, and battery charger). ferred from the module to a student’s PC once the experi- ment is over. The cost of the multifunctional module, The Maze Explorer represented in Figure 8 together with its block diagram, is Another application of the eSMAC robotic kit is in a maze about US$40. unit plan that aligns with middle-grade-level physical sci- With the ability to embed this multifunctional module ence standards or secondary-grade-level engineering design in a tennis ball, mathematics and science teachers can col- standards. Students begin by learning about and completing lect actual data from an object in flight and use that data as mazes while reflecting on the processes they follow to run a model for investigating trajectories of objects. In terms of through the maze. As an introduction to robotic program- learning outcomes, this application offers students hands- ming and control, the students begin n avigating the robot on experience with physics concepts such as acceleration, through a maze of their own design. They must then navi- velocity, and atmospheric pressure. Investigations using gate the robot through the maze again, using a prepro- this affordable tool can reveal to students many standards grammed series of steps that they calculate using basic that teachers set out to share. When students develop their constant velocity equations and measurements of the maze. own conclusions, learning becomes much richer and long Repeated iterations of this task instill an understanding of lasting. The requirements set by the NGSS can be easily the challenges and limitations in programming robots. The met using this modular equipment in a classroom. final lesson of the unit requires the students to construct their own hypothetical robot design for navigating the maze, Conclusions and Future Work which they then present and defend to other classmates. In The eSMAC robotic kit is designed in collaboration with this case, the robot takes advantage of an input module high school teachers for improving STEM education along (IMU or range sensing) to detect contacts with the maze the lines suggested by NGSS, recently introduced in the walls, a mobility module, and a powering module. A maze United States, that call for a more effective integration explorer and its block diagram are shown in Figure 7. The when teaching science and engineering. Thanks to modu- cost of materials to create the reconfigurable maze is about lar hardware and interoperable software architecture, the US$10 (two 20×30-in foam boards and box cutter), and eSMAC kit can be used to engage students in different one modular maze explorer costs approximately US$50 real-world experiments related to a variety of curricula. (robot base, IMU module, rechargeable battery module, This has the potential to facilitate an integrated approach and battery charger). to STEM education. Another advantage of the proposed
Computer with SMAC-2530 Board JSON Command (802.15.4 Wireless) eSMAC Maze Explorer Base Module (Control Motion) JSON Command (Wired Data Bus) IMU Module IEEE ProofBattery Module
Figure 7. A maze explorer and diagram of modules used for its implementation.
8 • IEEE ROBOTICS & AUTOMATION MAGAZINE • june 2016 Put eSMAC Send JSON Module in a Command to Tennis Ball Record IMU Data JSON Command (802.15.4 Wireless) eSMAC All-in-One-Module Embedded Accelerometer Acceleration and Orientation Data Embedded Flash Memory
Battery Module
JSON Command Data Stream (802.15.4 Wireless) (802.15.4 Wireless) Send JSON Receive the Command to Read Data on a Recorded Data Computer
Figure 8. A multifunctional module embedded in a tennis ball and its block diagram.
june 2016 • IEEE ROBOTICS & AUTOMATION MAGAZINE • 9 [4] LEGO Mindstorm. (2015, July 21). [Online]. Available: http://mind- [20] C. Piehler. (2015, Nov. 15). Survey: Teachers Spend $500 a Year of storm.lego.com Their Own Money on Classroom Supplies. [Online]. Available: https:// [5] VEX Robotics. (2015, July 21). [Online]. Available: http://www. thejournal.com/articles/2015/07/23/survey-average-teacher-spends- vexrobotics.com 500-out-of-pocket-on-classroom-supplies.aspx [6] Fishertechnik. (2015, July 21). [Online]. Available: http://www. fischertechnik.de/en/Home.aspx Ekawahyu Susilo, Department of Mechanical Engineering, [7] D. Kee, “Educational robotics—Primary and secondary education,” STORM Laboratory, Vanderbilt University, Nashville, Ten- IEEE Robot. Automat. Mag., vol. 18, pp. 16–99, Dec. 2011. nessee 37212. E-mail: [email protected]. [8] Kondo. (2015, July 21). [Online]. Available: http://kondo-robot.com [9] Bioloid. (2015, July 21). [Online]. Available: http://www.robotis. Jianing Liu, Department of Mechanical Engineering, com/xe/bioloid_en STORM Laboratory, Vanderbilt University, Nashville, Ten- [10] Cubelets. (2015, July 21). [Online]. Available: http://www.modro- nessee 37212. E-mail: [email protected]. botics.com/cubelets [11] K-Team. (2015, Nov. 16). [Online]. Available: www.k-team.com Yasmin Alvarado Rayo, Department of Mechanical Engi- [12] M. Rubenstein, B. Cimino, R. Nagpal, and J. Werfel, “AERobot: neering, STORM Laboratory, Vanderbilt University, Nash- An affordable one-robot-per-student system for early robotics educa- ville, Tennessee 37212. E-mail: yasmin.alvarado-rayo@ tion,” in Proc. IEEE Int. Conf. Robotics and Automation (ICRA), 2015, vanderbilt.edu. pp. 6107–6113.
IEEE Proof
10 • IEEE ROBOTICS & AUTOMATION MAGAZINE • june 2016 The robots can be If a signal is not detected programmed through a after a certain period of web-based user interface time, the module is allowed Future work will progress installed either as a plugin to promote itself as master, in parallel directions to or an app on the Google assign its own channel, expand the module library, Chrome browser. and start sending its own synchronization signal. enhance system reliability, and deploy eSMAC into the In the United States classroom. alone, jobs for biomedical Most STEM teaching and engineers are expected learning in K–12 grades to increase by 62% by in the United States has 2020, and jobs in software focused on science and development and medical mathematics but very science are expected to little on technology and The next modules in our increase by 32% and 36%, engineering. pipeline include Wi-Fi respectively. connectivity, aerial mobility with a quadrotor-inspired
Thanks to modular Expected learning base, and range sensing hardware and interoperable outcomes range from via optical and ultrasound software architecture, the composing code for techniques. eSMAC kit can be used to programming a robot to engage students in different a deeper understanding real-world experiments of physical quantities and related to a variety ofIEEE real-world experiments. Proof curricula.
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