关键词： Educational platforms   Teaching strategy   Computer simulations   Educational innovation  

摘要： Previous studies show that traditional teaching methods such as oral explanations and PowerPoint presentations can be complemented with the use of computer simulations in problem-solving sessions to teach robotics. Nevertheless, these previous works rest upon the assumption that the knowledge that is learned in virtual laboratories transfers to its equivalent real task. The main contribution of this work is to validate that the knowledge obtained by students in an undergraduate robotics course using computer simulations of 3D model robots can be applied to its real-world context. The experimental platform used to run the computer simulations was based on the Simscape Multibody library of the MATLAB (TM) software. Results show a satisfactory knowledge transfer because more than 75% of the students finished a forward kinematics problem using a physical manipulator built with LEGO Mindstorms (TM). In addition, the observation analysis of the professor reveals that students reinforced their knowledge previously learned, and their problem-solving and critical thinking skills also improved. In this way, this study demonstrates that the proposed methodology not only helps the transfer of knowledge to the real-world context but also helps to develop student competencies. Future work is needed to replicate the findings in other robotics topics, such as the generation of trajectories, the analysis of the dynamics of manipulators, and the design of various controllers for the actuators of the robot.

关键词： Swarm robotics   Aggregation   Self-organisation   Informed individuals  

摘要： Aggregation is a process observed in natural systems whereby individuals gather together to form large cluster. Recent studies with cockroaches and robots have shown that relatively simple individual mechanisms can account for how individuals manage to gather on a single shelter when two or more are available in the environment. In this paper, we use simulated swarms of robots to further explore the aggregation dynamics generated by these simple individual mechanisms. Our objective is to study the introduction of "informed robots", and to study how many of these are needed to direct the aggregation process towards a pre-defined site among those available in the environment. Informed robots are members of a group that selectively avoid the site/s where no aggregate should emerge and stop only on the experimenter pre-defined site/s for aggregation. We study the aggregation process with informed robots in three different scenarios: two that are morphologically symmetric, whereby the different types of aggregation site are equally represented in the environment;and an asymmetric scenario, whereby the target site has an area that is half the area of the sites that should be avoided. We first show what happens when no robot in the swarm is informed: in symmetric environments, the swarm is able to break the symmetry and aggregates on one of the two types of site at random, not necessarily on the target site, while in the asymmetric environment, the swarm tends to aggregate on the sites that are most represented in terms of area. The original contribution of this study is to demonstrate the effect of the introduction of a small proportion of informed robots in both environments: In symmetric environments, they selectively direct the aggregation process towards the experimenter chosen site;in the asymmetric environment, informed robots can invert the spontaneous preference for the most represented site and induce the swarm to aggregate on the least represented type of site.

关键词： creativity   educational robotics   pedagogical practices   instructional framework  

摘要： This study explored how educational robotics (ER) was implemented in classrooms to foster creativity among elementary school students and identified challenges associated with its implementation. Twenty-six teachers at different elementary schools were interviewed. In-depth teacher interviews and grounded theory were used to collect and analyze the interviews. We found that the intended creative learning outcome for students was mastery of the developmental process of creativity. The teachers generally reported using a four-phase instructional framework consisting of eight sub-phases and targeted teaching strategies to support students' learning outcomes. Challenges included insufficient appropriate learning materials, a lack of expansive learning activities and tasks and limited opportunities to engage students in the process of design thinking and developing metacognitive abilities. The findings have practical implications for teachers and researchers who are interested in developing pedagogical practices (PP) incorporating ER to support students' creativity. The study also has theoretical value, offering insights into teachers' PP in implementing ER.

关键词： Space debris  

摘要： With the number of large-scale facilities, malfunctioning spacecraft, and debris expected to increase in space, on-orbit servicing, including assembly, monitoring, maintenance, refueling and deorbiting, has become a major concern in space missions. Space robots can efficiently cope with a large number of on-orbit servicing missions while avoiding the high risks and reducing costs of extravehicular activity. The challenges of space robots with multiple arms include the complex dynamics and the coupling between the floating base and the end-effector. To handle these problems, a dynamics model with topological structure is firstly established for a four-arm space robot based on the kinematic chain symbolic calculus system and Axis-Invariants, which have the benefits of iterative structure and can avoid complex derivation of traditional dynamics modeling methods. Then, an attitude stabilization strategy consisting of improved nonlinear model predictive control and a hybrid actuator is implemented to handle the disturbance generated by the manipulation of multiple robot arms. The hybrid actuator can provide accurate control torque while simultaneously avoiding the singularity and saturation of the control moment gyro and reaction wheel, respectively. Finally, a scenario of space debris recycling is used to demonstrate the effectiveness of the proposed modeling and control strategy for on-orbit servicing missions with multiarmed space robots. (C) 2020 The Franklin Institute. Published by Elsevier Ltd. All rights reserved.

关键词： Parameter estimation   Fish-inspired robotics   Underwater robotics   Optimization   Anguilliform-inspired robot  

摘要： This paper presents an optimization-based approach to estimate the hydrodynamic parameters namely drag and added mass coefficients from free-running experiments conducted on an in-house developed Anguilliform-inspired robot. The objective of the optimization problem is to estimate the hydrodynamic parameters that minimize the differences between the trajectories obtained from the simulations and the physical experiments when operated for identical gait parameters and controller gains for both the straight and the turning motions. The hydrodynamic parameters obtained from the developed approach leads to a maximum root-mean-square (RMS) position error of 0.183 BL and a maximum RMS velocity error of 0.03 BL/s between the trajectories obtained from simulations and experiments. Experimental results suggest that the parameters estimated using the developed approach can be useful in predicting the robot's motion accurately. Accurate robot motion prediction is the fundamental requirement for localization, collision prediction, and motion planning algorithms which in turn are required for automated inspection, maintenance, and repair of sub-sea structures using Anguilliform-inspired robots.

关键词： artificial intelligence (AI)   robotics   analytical framework   learning designs   learning outcomes   learning trajectories  

摘要： This qualitative study examines the use of artificial intelligence (AI) and robotics in learning designs from the perspective of learning sciences. The literature on the topic indicates that there is not enough research on including diverse learning outcomes in the designs for learning. Therefore, the purpose of this study was to understand how AI and robots impact physical, social-emotional and intellectual learning outcomes through the implementation of learning designs that are guided by selected design principles. In this study, the design-based research (DBR) methodology was employed for investigating learning in naturalistic contexts. The intervention was implemented in a primary school in which learners used educational robots. The main findings reveal that the development of an integrated analytical framework, which considers a broader spectrum of human potential, allows for analyzing students' learning outcomes in a more integral, inclusive and balanced way. This, in turn, promotes students' learning by using AI and robots. Another finding reveals that the impact of using AI and robotics on learning designs is reflected in learners' personal trajectories having different pathways and paces. Finally, the lessons learned and the challenges to be overcome are summarized, and recommendations are made for future research for the enhancement of learning experiences that use AI and robotics.

关键词： Thematic integration   Task-based instruction   Integrative curriculum   Integrative STEM   Robotics  

摘要： The study aimed to develop a cross-disciplinary integrative STEM (i-STEM) robotics curriculum by the thematic integration approaches of webbed and threaded models, and to understand high school students' cognitions, attitudes, and interests in robotics STEM after the instruction. The concurrent mixed methods including quantitative experimental design and embedded qualitative design were adopted in the present study. Participants were 42 students, with 17 females and 25 males in a high school class. The students were grouped with 2 members in each group, and there were totally 21 groups. The results revealed that cognition for seven fields were significantly improved. Among the seven fields, sailboat design improved the most, while mathematics and computer programming improved the least. The students' attitudes and interests in robotics STEM were significantly enhanced. The students' interests in engineering design were significantly enhanced the most, programming was the second;continuous study of engineering, science, or technology was the third;jobs related to engineering or programming was the fourth;and robotics was the least enhanced. Finally, the implications for teacher teaching and student learning practices were proposed.

关键词： Topological mapping   Illumination invariance   Community detection   Robot localization  

摘要： Due to its vast applicability, the semantic interpretation of regions or entities increasingly attracts the attention of scholars within the robotics community. The paper at hand introduces a novel unsupervised technique to semantically identify the position of an autonomous agent in unknown environments. When the robot explores a certain path for the first time, community detection is achieved through graph-based segmentation. This allows the agent to semantically define its surroundings in future traverses even if the environment's lighting conditions are changed. The proposed semantic clustering technique exploits the Louvain community detection algorithm, which constitutes a novel and efficient method for identifying groups of measurements with consistent similarity. The produced communities are combined with metric information, as provided by the robot's odometry through a hierarchical agglomerative clustering method. The suggested algorithm is evaluated in indoors and outdoors datasets creating topological maps capable of assisting semantic localization. We demonstrate that the system categorizes the places correctly when the robot revisits an environment despite the possible lighting variation. (C) 2020 Elsevier B.V. All rights reserved.