Developing System-Thinking Oriented Learning Modules of Networked Mea- surement Systems for Undergraduate Engineering Curriculum

This paper describes the design of a set of system-thinking oriented learning modules of network measurement systems for data acquisition and instrumentation courses. The courseware was designed based entirely on open source components: including commercial-off-the-shelf (COTS) Wireless Sensor Nodes (WSN) and open source TinyOS-based software. The objective of the module is to introduce students to system-thinking oriented design of networked measurement systems, while taking into consideration the differences and details at component, system, and networking levels. The pedagogical model harnesses a wide range of wirelessly networked hardware/software co-design skills in engineering and technology (E&T) education to address a need for such skills in 21 st century instrumentation and measurement workforces. The six project-based learning modules with twenty-two hands-on experiments were developed for the networked measurement systems cover topics including how to select a sensor, fundamentals in analog and digital systems, and fundamentals of networking and data logging. Students learn about the system-oriented design procedures, configuration and programming of wirelessly networked sensor nodes, visualization and analysis of monitoring data from any individual sensor on the node, as well as the state of the node. After completing these modules, students will be able to design, develop, and implement a networked measurement system to solve real world problems. Introduction Recent advances in sensing, computing, and communication have shifted the paradigm in the practices of instrumentation and measurement, resulting in a proliferation of networked data acquisition systems usage in industries such as manufacturing, aerospace, agriculture, healthcare, and homeland security. As a result, the need to prepare 21 st century instrumentation and measurement professionals to design, implement, and operate such systems is imperative. Given the tremendous advances in wireless networking technology, wirelessly networked data acquisition (DAQ) systems are seeing increased adoption in the real world. Wireless sensor networks (WSN) have been shown to be an effective educational platform for students to learn about networked DAQ mainly because they get the hands-on experience of hardware/software co-design. In the traditional setting, instructors setup the whole data acquisition system before the class due to its complexity. Students, on the other hand, would not have the opportunity to experience the details of the DAQ (its components, how they are connected and collaborate with each other to achieve the data collection objective). Instead, their involvement focuses more on how to visualize and analyze the data after getting data output from the DAQ software driver. In this paper, we describe in detail a set of system-thinking oriented learning modules for data acquisition (DAQ) and instrumentation courses. Instead of focusing on individual components of such systems, the modules are intended to guide students to focus on the functionality of each component and the effect of its interaction with others in the system. The P ge 23406.2 critical thinking skills trained in these modules enable students to make decisions during the development and implementation of such DAQ systems to solve real world problems under the constraints of available resources (funds, time, personnel, etc.) The courseware was designed based entirely on open source components: including commercial-off-the-shelf (COTS) Wireless Sensor Nodes (WSN) and open source TinyOS-based software. The objective of the module is to introduce students to system-thinking oriented design of networked measurement systems, taking into consideration necessary details at component, system, and networking levels. The pedagogical model harnesses a wide range of wirelessly networked hardware/software co-design skills in engineering and technology education to address a need in 21st century instrumentation and measurement workforces. The developed modules have been offered in several courses since 2010 and the assessment results demonstrate that they not only effectively introduced recent technology advances in wireless sensor networks to students, but also nurtured their system-level critical thinking skills. Six project-based WSN learning modules with twenty-two hands-on experiments were developed to teach students the fundamentals of WSN design and how to develop networked data acquisition systems to monitor and control a physical system. These six modules were distributed across four WSN technical content areas: component-level, system-level, networklevel, and capstone/project-level. Learning outcomes in each area reflect the overall goals of the project and include: (1) at the component level, students will demonstrate their ability to (a) select appropriate sensors to monitor physical phenomena and (b) design analog and digital signal conditioning circuits to connect them to microcontroller/computers; (2) at the system level, students will be able to identify and use current technology practiced in monitoring and control systems; (3) at the network level, students will be able to (a) understand fundamental concepts of WSN, and (b) design and develop such a system; and (4) at the capstone/project level, students will be able to demonstrate their capability to design, develop, implement, and test a networked data acquisition system to monitor and control a physical system based on customer requirements collected. At the component level, learning modules and related hands-on experiments were developed from a system design perspective to provide an opportunity for students to learn how to select the appropriate sensors to monitor the physical phenomenon and how to design necessary analog and digital signal conditioning circuits to connect them to micro-controller/computers. The system level learning modules were designed to help students familiarize themselves with current technology used in monitoring and control such as integrated sensor boards, commercial-off-theshelf (COTS) general purpose DAQ hardware and software development environment. At the network level, six hands-on experiments were developed to teach fundamentals of WSN with emphasis on the research-oriented TinyOS-based open platform. After students successfully complete these learning modules, they are entrusted to develop a WSN for a real world application. Three such systems were developed to illustrate the design process of such a system and to assist students’ efforts in their capstone projects. All of the manuals for the handson experiments can be accessed from project website [1]. In the next section, we will describe the component and system level learning modules; Section 3 will detail the network level learning modules, while Section 4 focuses on capstone projects. Section 5 discusses assessment results collected from the courses we offered. Finally, Section 6 concludes the paper and provides some insight towards future direction of improving STEM education. P ge 23406.3 Component and System Level Learning Modules Component level learning modules include two parts: (1) analog and digital signal conditioning and (2) sensors. The analog and digital signal conditioning module serves as the bridge for students to reflect on what they have learned in courses such as analog circuits and digital logic and apply the relevant concepts to signal conditioning, with a focus on operational amplification (OpAmp) and digital signal conditioning circuits such as analog-to-digital-converters (ADC) and digital-to-analog-converters (DAC). The five hands-on experiments developed for this module include: RC circuits frequency response and Multisim workbench (a circuit design and simulation tool from National Instruments (NI) [2]); analog power source and regulation circuits; basic OpAmp circuits; OpAmp signal conditioning circuits and linearization; and implementing comparators in pSoCs (programmable system-on-a-chip). A set of multi-media lecture notes and three hands-on experiments were developed to facilitate students’ learning of various sensing technologies to measure temperature/thermal, mechanical (motion/force/pressure/flow), and optical phenomenon. The three hands-on experiments developed in this module include: (1) thermistor and first order time response; (2) DAQ design for thermocouples; (3) and strain gauges and load cell. Through these experiments, students are expected to verify the static and dynamic behavior of the sensors they learned in theory and connect sensors’ performance with their respective specification sheet. Figure 1 shows a sample of the component level thermal sensor experiment pre-lab manual developed for thermocouples. The full manual can be accessed from the website of the project [3]. Figure 1 Component Level Experiment: Thermocouple Pre-lab