Robust stability analysis of formation control in local frames under time-varying delays and actuator faults

This paper investigates the robust stability of a multiagent system moving to a desired rigid formation in presence of unknown time-varying communication delays and actuator faults. Each agent uses relative position measurements to implement the proposed control method, which does not require common coordinate references. However, the presence of time delays in the measurements, which is inherent to the communication links between agents, has a negative impact in the control system performance leading, in some cases, to instability. Furthermore, the robust stability analysis becomes more complex if failures on actuators are taken into account. In addition, delays may be subject to time variations, depending on network load, availability of communication resources, dynamic routing protocols, or other environmental conditions. To cope with these problems, a sufficient condition based on Linear Matrix Inequalities (LMI) is provided to ensure the robust asymptotic convergence of the agents to the desired formation. This condition is valid for any arbitrarily fast time-varying delays and actuator faults, given a worst-case point-to-point delay. Finally, simulation results show the performance of the proposed approach.     

Competency Maps: an Effective Model to Integrate Professional Competencies Across a STEM Curriculum

Curricula designed in the context of the European Higher Education Area need to be based on both domain-specific and professional competencies. Whereas universities have had extensive experience in developing students’ domain-specific competencies, fostering professional competencies poses a new challenge we need to face. This paper presents a model to globally develop professional competencies in a STEM (science, technology, engineering, and mathematics) degree program, and assesses the results of its implementation after 4 years. The model is based on the use of competency maps, in which each competency is defined in terms of competency units. Each competency unit is described by a set of expected learning outcomes at three domain levels. This model allows careful analysis, revision, and iteration for an effective integration of professional competencies in domain-specific subjects. A global competency map is also designed, including all the professional competency learning outcomes to be achieved throughout the degree. This map becomes a useful tool for curriculum designers and coordinators. The results were obtained from four sources: (1) students’ grades (classes graduated from 2013 to 2016, the first 4 years of the new Bachelor’s Degree in Informatics Engineering at the Barcelona School of Informatics); (2) students’ surveys (answered by students when they finished the degree); (3) the government employment survey, where former students evaluate their satisfaction of the received training in the light of their work experience; and (4) the Everis Foundation University-Enterprise Ranking, answered by over 2000 employers evaluating their satisfaction regarding their employees’ university training, where the Barcelona School of Informatics scores first in the national ranking. The results show that competency maps are a good tool for developing professional competencies in a STEM degree.     

Students’ Views of Design in an Engineering Design-Based Science Curricular Unit

Recent reforms in science education have supported the inclusion of engineering and their practices in K-12 curricula. To this end, many classrooms have incorporated engineering units that include design challenges. Design is an integral part of engineering and can help students think in creative and interdisciplinary ways. In this study, we examined students’ conceptions of design during and after participation in a design-based science curriculum unit. Our study was guided by the following research question: What are students’ views of design after participation in an engineering design-based science curriculum unit and how are these views reflected in their enactment throughout the unit? Using a qualitative approach, we examined students’ conversations throughout the enactment of the curriculum and interviews conducted after the completion of the unit. We found that students had complex and diverse views of design, and these views were reflected in their group discussions throughout the curriculum and design challenge. Students most frequently expressed design as learning and as a process of integration into a coherent whole. These aspects of design were also frequently observed in students’ conversations during the unit. Interestingly, we found evidence of students demonstrating several aspects of design throughout the curriculum that were not explicitly expressed during the student interviews. Taken together, these findings support the complex nature of design as seen at the middle school level.