Experiential learning can make engineering concepts come to life, giving students a real-world confirmation of the theory and concepts from lecture classes. All too often, however, undergraduate laboratory classes fall short of enhanced learning and are instead more notable for student dissatisfaction and/or frustration (Holmes and Wieman, 2018; Koretsky, et al., 2011; Hofstein and Lunetta, 2004). There are several reasons for this problem. First, organized laboratory classes are often used to meet numerous student outcomes such as those comprising ABET student outcomes (1) – (7) (www.abet.org). Second, organized laboratory classes are often taught separately from theory classes, leading to a disconnect from pre-requisite courses and uneven understanding among the student cohort. Third, organized lab classes often involve teamwork, without specific instruction or guidance on how to work effectively, how to divide up tasks, and how to handle conflicts. Due to advances in microprocessors and portable data acquisition devices, widespread student use of laptop computers, growing availability of affordable sensors, and the emergence of versatile 3D printers and benchtop CNC machining, there is an unprecedented opportunity to bring hands-on experiments out of the centralized labs, and into lecture classrooms, and even student dorm rooms. The portability of the platforms can obviate the need for dedicated lab space and equipment. Furthermore, small, portable hands-on platforms can be designed to target one or two specific learning objectives. This ensures that the concepts involved in the hands-on exercises are tightly coupled to the theory delivered in lectures and assessed in homework assignments. The paper will review progress in the development of new hands-on learning experiences. A final consideration in creating an effective learning experience for students is the question of team dynamics. At the authors’ institution, the hands-on experiments are usually performed by small teams of students (2 or 3-person teams) that are formed based on seating proximity. At times, such impromptu pairing causes problems for a number of reasons. The authors are particularly interested in Diversity Equity and Inclusion (DEI) issues that can undermine the effective learning in these teams when female or underrepresented minorities are involved. Since the teams are transient (i.e., formed expressly to perform a task within the context of a single, 50-minute class) there isn’t time to include teaming instructions at the beginning of each exercise. Thus, policies and procedures are necessary to promote collaboration, and the training must be intentionally designed to be as portable as the experiments themselves.

Pedagogical innovation efforts in engineering education and other STEM fields highlight some of the inherent challenges and opportunities in the process of strengthening undergraduate education. While interactive pedagogical approaches involving peer teamwork and a mix of in-person and online resources have strengthened the quality of teaching/learning, few studies provide a close-up examination of how faculty members navigate the implementation of new learning systems developed in other institutional settings. In this paper we examine factors contributing to the lack of sustained adoption of an engineering learning system called Freeform in a new academic context. We found that while students lauded the learning system's potential for deep learning practices, the lead instructor encountered several challenges in its implementation which precluded him from adopting the system in the long term. While the lead instructor recognized the pedagogical value of Free formin helping students engage deeply with engineering concepts, he found its implementation to differ too greatly from his traditional teaching trajectory in addition to increasing his preparation workload and having other logistical barriers. Ultimately, Free form was not compatible with the specific institutional culture of the engineering department where the study took place. We offer some potential solutions to ameliorate issues of compatibility when attempting to diffuse and implement pedagogical systems in different institutional contexts.

With support from the National Science Foundation, an evidence-based experimental centric pedagogy (ECP) is being implemented across STEM disciplines at an historically black university. This is the first of its kind, where the ECP is being extended to several STEM disciplines after its successful implementation in electrical engineering to promote motivation and enhance academic achievement of minority students. One of the project objectives is to organize workshops whereby STEM faculty in biology, chemistry, physics, civil engineering, computer science, industrial engineering and transportation systems will learn how to develop and implement ECP as an active learning pedagogy. This paper highlights the strategies used for planning, publicity, implementation, and assessment of the workshop conducted in Summer 2020. Due to the ongoing pandemic, the workshop was held virtually with 360 participants registering globally. The workshop's focus was developing and implementing inexpensive home-based hands-on learning activities. Workshop assessment revealed that participants expressed positive outcomes, 84% reported that they believe the workshop was a good use of their time and 83% said they plan to implement what they had learned at the workshop in their own practice, affording the participants more opportunities to include home-based hands-on learning in their curriculum. This project seeks not only to increase public scientific literacy, but to also contribute to the development of a diverse, globally competitive STEM workforce.

This table-top experiment for education is suitable for courses in systems and signals, system dynamics, and vibrations. The experimental platform is low cost and portable so that students do experiments at their desks within a classroom setting and during a normal class period. The platform consists of a guitar string, guitar pickup, tuner, and a bridge. Students also need to have a signal processor unit, such as a National Instruments myDAQ, which turns a laptop into an oscilloscope and spectrum analyzer.

With the computational systems of even embedded devices becoming ever more powerful, there is a need for more effective and pro-active methods of dynamic power management. The work presented in this paper demonstrates the effectiveness of a reinforcement-learning based dynamic power manager placed in a software framework. This combination of Q-learning for determining policy and the software abstractions provide many of the benefits of co-design, namely, good performance, responsiveness and application guidance, with the flexibility of easily changing policies or platforms. The Q-learning based Quality of Service Manager (2QoSM) is implemented on an autonomous robot built on a complex, powerful embedded single-board computer (SBC) and a high-resolution path-planning algorithm. We find that the 2QoSM reduces power consumption up to 42% compared to the Linux on-demand governor and 10.2% over a state-of-the-art situation aware governor. Moreover, the performance as measured by path error is improved by up to 6.1%, all while saving power.

This paper describes the design and performance of Q-learning-based quality-of-service manager (2QoSM) for compute-aware applications (CAAs) as part of platform-agnostic resource management framework. CAAs and hardware are able to share metrics of performance with the 2QoSM and the 2QoSM can attempt to reconfigure CAAs and hardware to meet performance targets. This enables many co-design benefits while allowing for policy and platform portability. The use of Q-Learning allows online generation of the power management policy without requiring details about system state or actions, and can meet different goals including error, power minimization, or a combination of both. 2QoSM, evaluated using an embedded MCSoC controlling a mobile robot, reduces power compared to the Linux on-demand governor by 38.7-42.6% and a situation-aware governor by 4.0-10.2%. An error-minimization policy obtained a reduction in path-following error of 4.6-8.9%.

Active learning is known to promote a deeper understanding and retention of concepts. Hands-on learning is a particular form of active learning where students engage in a topic in several different ways including sight, sound, and tactile sensory input. While engaging multiple senses, students can interact with other students and reflect on how their understanding of some topic can be used to explain a particular phenomenon. When the hands-on experiences are well-designed, students can go beyond the lecture material and observe how theory is manifested in the real world. Unfortunately, many engineering experiments are costly and complicated, restricting their use to instructional laboratories. One of the goals of this NSF IUSE project is to create simple hands-on experiments that can be highly portable for use in lecture rooms, laboratories, or even dorm rooms. Due to advances in portable data acquisition devices, laptop computers, and affordable sensors, there is an unprecedented opportunity to make hands-on engineering experiments a reality. The use of analog circuits constructed from breadboards and electrical components (resistors, capacitors, inductors, op-amps, etc) has already made considerable inroads in electrical engineering education. One goal of this project is to bring equally effective and affordable solutions to the fields of mechanical engineering (ME) and aerospace engineering (AE). Making ME and AE hands-on experiments more portable and affordable would allow them to be used in different settings such as classrooms and dormitories, but there are significant challenges. Many ME and AE experiments require moving parts, fluid flow under pressure, structures, thermal effects all at a scale that students can see, touch, or hear the physical phenomena being investigated. This research builds upon our previous work in hands-on pedagogy in the ECE education and seeks to apply it to new platforms designed for ME and AE subjects. Among the research questions that are being addressed several stand out: Which topics have the greatest potential for enhancing educational outcomes through hands-on learning? What is the impact of the experiments on student performance, on student interest and confidence in the subject matter, and on long-term retention of the knowledge? Do these experiments have a positive impact on students from underrepresented groups in terms of performance, student interest, and retention? Since hands-on education is often associated with collaboration and group work, what are the best practices for impromptu team work, especially in the context of diversity and underrepresentation in these student groups? To address these research question, the research has several objectives. One goal is to develop experimental platforms and supplemental materials to support the learning of basic concepts and higher-level thinking processes in ME and AE courses. Part of this effort entails designing short learning experiences that are well thought out, and involve adequate levels of engagement and reflection. We also seek to develop appropriate assessment techniques to measure the effect of the hands-on experiments. Finally, we are developing strategies for managing impromptu team-work between small numbers of students so that all team members are equally engaged and included in the learning process. This is particularly important for female and underrepresented groups within STEM fields.

Engineering curricula are known to be challenging because they require high-level technical knowledge, critical thinking, and creative problem solving skills. The curricula are characterized as having long pre-requisite chains because high-level material requires understanding of core engineering knowledge, which in turn rests on a wide spectrum of math and science courses. In mechanical engineering, one of the critical pre-requisite chains involves the so called “mechanics sequence,” which runs from Physics to Statics and then to Mechanics and Dynamics. This paper examines how performance in these key classes affects students’ persistence in engineering, as measured by GPA at graduation and time-to-graduate. It is found that Statics has the largest impact on the academic success of struggling mechanical engineering students. While some students can overcome poor grades in Physics, struggles in Physics often foretell continued problems throughout the mechanical engineering curriculum.

This article describes the development of a software architectural framework for implementing compute-aware control systems, where the term "compute-aware" describes controllers that can modify existing low-level computing platform power managers in response to the needs of the physical system controller. This level of interaction means that high-level decisions can be made as to when to operate the computing platform in a power-savings mode or a high-performance mode in response to situation awareness of the physical system. The framework is demonstrated experimentally on a mobile robot platform. In this example, a situation-aware governor is developed that adjusts the speed of the processor based on the physical performance of the robot as it traverses a path through obstacles. The results show that the situation-aware governor results in overall power savings of up to 38.9 percent with 1.3 percent degradation in performance compared to the static high-power strategy.

When laying down a long slender beam from a near-vertical orientation, to a horizontal position on a flat surface, the payload may slip and move suddenly in unintended and unpredictable ways. This occurs during crane operations when the movements of the overhead trolley and lowering of the hoist cable are not properly coordinated. The payload's unintended sliding can potentially cause damage and injure people. This paper presents static and dynamic analyses of slender-beam payload lay-down operations that establish a structured method to predict the safe conditions for lay-down operations. Also, a new method to measure the friction coefficient of surface-to-line contact is proposed. Lay-down experiments are carried out to verify the theoretical predictions.

Shock isolation systems are often modeled as having lumped stiffness and damping characteristics. However, the isolation performance may be improved if the isolation mount is allowed to have internal dynamics. Previous work has considered several different ways of disrupting the disturbance as it propagates along the length of a multi-degree-of-freedom mount. In this paper, the role of internal damping of the mount is re-examined. Furthermore, the damping model is extended to allow different levels of damping in different response regimes. Through simulation of the shock response, the findings show that the optimal level of internal damping depends on the magnitude of the input shock. For small shocks, performance is best for a relatively high level of damping, but for larger shocks, the best damping value drops to a much lower value. The effect on isolation performance of having different damping levels in different response regimes is shown to be fairly modest, and is shown to depend on the input excitation level.

There are many methods developed to mitigate transients induced when abruptly changing dynamic algorithms such as those found in digital filters or controllers. These “bumpless transfer” methods have a computational burden to them and take time to implement, causing a delay in the desired switching time. This paper develops a method that automatically reconfigures the computational resources in order to implement a transient management method without any delay in switching times. The method spawns a speculative thread when it predicts if a switch in algorithms is imminent so that the calculations are done prior to the switch being made. The software framework is described and experimental results are shown for a switching between filters in a filter bank.

When lifting up a long slender beam from ground, the payload may slip or move suddenly in unintended and unpredictable ways. This occurs during crane operations when the movements of the overhead trolley and the hoist cable are not properly coordinated. Also, it is difficult to keep the centers of hook and payload mass aligned with the pivot point when the payload is lifted off the ground, resulting in undesired hook and payload swing. The payload’s unintended sliding or swing can potentially cause damage and reduce efficiency. This paper divides the lift-up process into two phases including a constrained phase and a free hanging phase, develops a combination of PID controller and speed envelope to prevent slip in the constrained phase, and presents an observer-based Linear Quadratic Regulator (LQR) control strategy to stabilize the double-pendulum oscillations in the free hanging phase. The robustness of the proposed observer-based LQR was analyzed. Lift-up experiments were carried out to verify the controller development.

Classical structural analysis techniques have proven time and time again to be remarkably accurate for systems consisting of a single, continuous piece of material. Unfortunately, nearly all real engineering structures are assembled from multiple parts, joined by bolts, rivets, or other fasteners, and these joints introduce nonlinearities and uncertainties into systems’ structural stiffness and damping. Nonlinear damping due to jointed connections in particular is critical to limiting the resonant response of a structure, yet it remains poorly understood. This work seeks to understand the degree to which joint properties are dependent on the rest of the structure. The testable hypothesis is that the boundary conditions and the far-field structure itself (i.e. distribution of the stiffness and mass) change the way in which the interface is loaded, thus altering the perceived or deduced nonlinear properties of the mechanical joint. This hypothesis is investigated using experimental impact hammer testing methods in order to understand the extent to which alteration in the boundary conditions and far-field structure change the interface properties as well as the underlying mechanics during loading. Numerical tools are also employed to investigate and complement the experimental results, focusing on two fronts: replicating the experimental results with discrete joint models, and investigating joint loading for different modes using numerical modal analysis.

When cranes lift payloads off the ground, the payload may slide sideways or swing unexpectedly. This motion occurs when the payload is not directly beneath the overhead suspension point of the hoist cable. Given that cable suspension points can be hundreds of feet above the payload, it is difficult for crane operators to know if the hoist cable is vertical before lifting the payload off the ground. If an off-center lift creates substantial horizontal motion, then it can create significant hazards for the operators, the payload, and the surrounding environment. This paper develops a three-dimensional dynamic model that predicts motions of off-centered lifts.

This paper considers the use of a chain of translating carts or housings having internally rotating eccentric masses in order to accomplish vibration isolation. First a single degree-of-freedom system is harmonically excited to uncover the qualitative behavior of each rotating mass. The simple model is then expanded into a chain of housings, containing rotating eccentric masses, which are interconnected with springs. The internal rotating eccentric masses are damped along their circular pathway by means of linear viscous damping. Due to the lack of elastic or gravitational constraint on the rotating eccentric masses, they provide a nonlinear inertial coupling to their housings. Previous research has shown that such systems are capable of reducing shock or impulsive loading by converting some of the translational kinetic energy into rotational kinetic energy of the internal masses. This paper examines the potential for vibration isolation of a chain of such systems subjected to persistent, harmonic excitation. It is seen that the dynamics of these systems is very complicated, but that trends are observed which have implications for practical isolation systems. Using simulation studies, tradeoffs are examined between displacement and transmitted force for a range of physical parameter values.

This paper considers the use of a chain of springs and masses to reduce the transmission of shock and vibration through the system. The masses are equipped with internally rotating masses that absorb some of the axial vibration into internal kinetic energy of the masses. The internal masses have viscous damping, but no elastic or gravitational restraint. Previous research has shown that a single cart system attached to a vibrating structure can help mitigate shock through targeted energy transfer. This paper examines the potential for shock isolation provided by a chain of such systems. Through numerical simulations, tradeoffs are examined between displacement and transmitted force.