Tag Archives: Useful For Teaching

Interesting testing (simulated) bed for quadrotors

April 26, 2024 09:26 ,

Júnio Santos Bulhões, Cristiane Lopes Martins, Cristian Hansen, Márcio Rodrigues da Cunha Reis, Alana da Silva Magalhães, Antonio Paulo Coimbra, Wesley Pacheco Calixto, Platform and simulator with three degrees of freedom for testing quadcopters, Robotics and Autonomous Systems, Volume 176, 2024 DOI: 10.1016/j.robot.2024.104682.

This study aims to design a test platform for quadcopters, which allows the execution of all rotational movements and prevents translational movements without affecting the dynamics of the system. The methodological approach involves both simulation and the construction of the test platform. Two simulators are developed: (i) a linear simulator, used to assist in determining control parameters, and (ii) a nonlinear simulator, used to model the nonlinearity inherent to the rotational behavior of aircraft. In addition, the control system for the quadcopter is implemented, utilizing proportional, integral, and derivative control principles. By conducting seven experiments on the test platform and in the nonlinear simulator, the obtained results are compared in order to validate the proposed methodology. The mean discrepancy observed between the mean absolute difference obtained by the test platform and by the nonlinear simulator for the angle ϕ was 0.85°, for the angle θ was 2.77°, and for the angle ψ was 4.66°. When analyzed separately, the mean absolute errors for the angles, using the nonlinear simulator and the test platform, showed differences below 2% in almost all evaluated experiments. The developed test platform preserves the rotational dynamics of the quadcopter as desired, closely approaching the results obtained by the nonlinear simulator. Consequently, this platform can be used to carry out practical tests in a controlled environment.

Posted in: Robotic software , Tagged: , ,

Interesting way of explaining pointers and arrays of C in teaching programming

December 21, 2023 11:06 ,

W. Rong, T. Xu, Z. Sun, Z. Sun, Y. Ouyang and Z. Xiong, An Object Tuple Model for Understanding Pointer and Array in C Language, IEEE Transactions on Education, vol. 66, no. 4, pp. 318-329, Aug. 2023 DOI: 10.1109/TE.2023.3236027.

Contribution: In this study, an object tuple model has been proposed, and a quasi-experimental study on its usage in an introductory programming language course has been reported. This work can be adopted by all C language teachers and students in learning pointer and array-related concepts. Background: C language has been extensively employed in numerous universities as an introductory programming practice. However, the pointer and array have long been recognized as some of the most difficult concepts for novice students learning C language. To help students become familiar with the concept of pointer and array and also their related operations, a comprehensive understanding from memory management\u2019s perspective might be helpful. Research Questions: 1) How does the object tuple model help students understand all kinds of object types from a generalized perspective? 2) Why is it important to let the students consider multiple arrays from a 1-D perspective? and 3) How do the memory-oriented operations from the object\u2019s perspective help students comprehensively understand the pointer and array? Methodology: The students were divided into experimental and control groups, and the object tuple model was presented in the experimental group. An examination was conducted at end of the semester, and test data were gathered for further analysis. Findings: The proposed object tuple model is effective in giving students clear guidance and helping them further understand the pointer and array in C language.

Posted in: Education , Tagged: ,

Measuring conceptual understanding of Systems & Signals university subjects

December 5, 2023 10:20 ,

C. Crockett, H. C. Powell and C. J. Finelli, Conceptual Understanding of Signals and Systems in Senior Undergraduate Students, IEEE Transactions on Education, vol. 66, no. 2, pp. 113-122, April 2023 DOI: 10.1109/TE.2022.3199079.

Contribution: This article proposes a new definition of conceptual understanding (CU) specific to engineering. It then measures CU of signals and systems (S&S) in senior undergraduate students and describes how students approach conceptual problems. Background: Previous studies across multiple engineering subjects show students have low CU at the end of courses. However, little is known about CU semesters after a course. Research Questions: What is the CU of S&S concepts among electrical engineering senior students? Methodology: This mixed method study uses quantitative concept inventory data (n=467) and think-aloud interviews (n=12) to measure CU. The results come from two universities. Findings: Seniors\u2019 scores on the concept inventory are typical of scores presented at the end of an S&S course. Many struggled with the concept of linearity, made a common error when finding the maximum value in graphical convolution, and had low confidence on relating frequencies in time to a Fourier transform representation, but seniors had relatively high CU of time invariance and filtering.

Posted in: Education , Tagged: , ,

Current state of the practical use of real-time systems, got through industry questionnaires

November 3, 2023 09:54 ,

Akesson, B., Nasri, M., Nelissen, G. et al. A comprehensive survey of industry practice in real-time systems, Real-Time Syst 58, 358\u2013398 (2022) DOI: 10.1007/s11241-021-09376-1.

This paper presents results and observations from a survey of 120 industry practitioners in the field of real-time embedded systems. The survey provides insights into the characteristics of the systems being developed today and identifies important trends for the future. It extends the results from the survey data to the broader population that it is representative of, and discusses significant differences between application domains. The survey aims to inform both academics and practitioners, helping to avoid divergence between industry practice and academic research. The value of this research is highlighted by a study showing that the aggregate findings of the survey are not common knowledge in the real-time systems community.

Posted in: Real-Time Systems , Tagged: ,

A remote Matlab laboratory for LTI system identification

November 3, 2023 09:32 ,

Z. Lei, H. Zhou, W. Hu and G. -P. Liu, Teaching and Comprehensive Learning With Remote Laboratories and MATLAB for an Undergraduate System Identification Course, EEE Transactions on Education, vol. 65, no. 3, pp. 402-408, Aug. 2022 DOI: 10.1109/TE.2021.3123302.

Contribution: This article introduces the teaching and learning with remote laboratories and MATLAB for an undergraduate system identification (SI) course, which can be employed for students at the advanced level with a control background. Background: SI has been widely used in all engineering fields; thus, the SI course that includes complex theories, concepts, and formulas is crucial for engineering education. Constraints, such as time, space, cost, and maintenance work, pose limitations for conventional laboratories, and current remote laboratories may not offer experiences to enhance control-oriented practical skills. Intended Outcomes: The proposed teaching and learning using remote laboratories is intended to facilitate the understanding of theories and concepts, and enhance the ability of design and implementation of control algorithms, the conducting of experiments, data collecting, data analysis, and the conducting of SI with MATLAB. Application Design: In the classroom teaching, theoretical lectures regarding SI are delivered to students by the teacher, along with the classroom demonstration with the networked control system laboratory for online experimentation. Then, the laboratory work is required to be completed by the students using the remote laboratory. A tailored laboratory report is supposed to be handed in by each student after the experimentation. Findings: The effectiveness of the proposed method was evaluated through the analysis of student performance and student responses to surveys. The student performance analysis indicates that the application of the remote laboratories is effective, and the feedback from students shows that they can benefit from the application of remote laboratories, and they would like the remote laboratories to be expanded to other courses.

Posted in: Control Engineering , Tagged: , , ,

On the importance of the static structures + execution flow in learning programming languages

November 3, 2023 09:27 ,

B. Bettin, M. Jarvie-Eggart, K. S. Steelman and C. Wallace, Preparing First-Year Engineering Students to Think About Code: A Guided Inquiry Approach, IEEE Transactions on Education, vol. 65, no. 3, pp. 309-319, Aug. 2022 DOI: 10.1109/TE.2021.3140051.

In the wake of the so-called fourth industrial revolution, computer programming has become a foundational competency across engineering disciplines. Yet engineering students often resist the notion that computer programming is a skill relevant to their future profession. Here are presented two activities aimed at supporting the early development of engineering students\u2019 attitudes and abilities regarding programming in a first-year engineering course. Both activities offer students insights into the way programs are constructed, which have been identified as a source of confusion that may negatively affect acceptance. In the first activity, a structured, language-independent way to approach programming problems through guided questions was introduced, which has previously been used successfully in introductory computer science courses. The team hypothesized that guiding students through a structured reflection on how they construct programs for their class assignments might help reveal an understandable structure to them. Results showed that students in the intervention group scored nearly a full letter grade higher on the unit\u2019s final programming assessment than those in the control condition. The second activity aimed to help students recognize how their experience with MATLAB might help them interpret code in other programming languages. In the intervention group, students were asked to review and provide comments for code written in a variety of programming languages. A qualitative analysis of their reflections examined what skills students reported they used and, specifically, how prior MATLAB experience may have aided their ability to read and comment on the unfamiliar code. Overall, the ability to understand and recognize syntactic constructs was an essential skill in making sense of code written in unfamiliar programming languages. Syntactic constructs, lexical elements, and patterns were all recognized as essential landmarks used by students interpreting code they did not write, especially in new languages. Developing an understanding of the static structure and dynamic flow required of programs was also an essential skill which helped the students. Together, the results from the first activity and the insights gained from the second activity suggest that guided questions to build skills in reading code may help mitigate confusion about program construction, thereby better preparing engineering students for computing-intensive careers.

Posted in: Computer science , Tagged: ,

Probabilistic ICP (Iterative Closest Point) with an intro on classical ICP

October 27, 2023 05:45 ,

Breux Y, Mas A, Lapierre L. On-manifold probabilistic Iterative Closest Point: Application to underwater karst exploration, The International Journal of Robotics Research. 2022;41(9-10):875-902 DOI: 10.1177/02783649221101418.

This paper proposes MpIC, an on-manifold derivation of the probabilistic Iterative Correspondence (pIC) algorithm, which is a stochastic version of the original Iterative Closest Point. It is developed in the context of autonomous underwater karst exploration based on acoustic sonars. First, a derivation of pIC based on the Lie group structure of SE(3) is developed. The closed-form expression of the covariance modeling the estimated rigid transformation is also provided. In a second part, its application to 3D scan matching between acoustic sonar measurements is proposed. It is a prolongation of previous work on elevation angle estimation from wide-beam acoustic sonar. While the pIC approach proposed is intended to be a key component in a Simultaneous Localization and Mapping framework, this paper focuses on assessing its viability on a unitary basis. As ground truth data in karst aquifer are difficult to obtain, quantitative experiments are carried out on a simulated karst environment and show improvement compared to previous state-of-the-art approach. The algorithm is also evaluated on a real underwater cave dataset demonstrating its practical applicability.

See also: Maken FA, Ramos F, Ott L. Bayesian iterative closest point for mobile robot localization. The International Journal of Robotics Research. 2022;41(9-10):851-874. doi:10.1177/02783649221101417

Posted in: Mobile Robot Localization , Tagged: ,

A nice summary of SLAM in robotics with Lidar and Cameras

October 13, 2023 09:24 ,

Chghaf, M., Rodriguez, S. & Ouardi, A.E. Camera, LiDAR and Multi-modal SLAM Systems for Autonomous Ground Vehicles: a Survey J Intell Robot Syst 105, 2 (2022) DOI: 10.1007/s10846-022-01582-8.

Simultaneous Localization and Mapping (SLAM) have been widely studied over the last years for autonomous vehicles. SLAM achieves its purpose by constructing a map of the unknown environment while keeping track of the location. A major challenge, which is paramount during the design of SLAM systems, lies in the efficient use of onboard sensors to perceive the environment. The most widely applied algorithms are camera-based SLAM and LiDAR-based SLAM. Recent research focuses on the fusion of camera-based and LiDAR-based frameworks that show promising results. In this paper, we present a study of commonly used sensors and the fundamental theories behind SLAM algorithms. The study then presents the hardware architectures used to process these algorithms and the performance obtained when possible. Secondly, we highlight state-of-the-art methodologies in each modality and in the multi-modal framework. A brief comparison followed by future challenges is then underlined. Additionally, we provide insights to possible fusion approaches that can increase the robustness and accuracy of modern SLAM algorithms; hence allowing the hardware-software co-design of embedded systems taking into account the algorithmic complexity and the embedded architectures and real-time constraints.

Posted in: Mobile robot SLAM , Tagged: ,

A nice summary of RL applied to robot navigation

October 13, 2023 09:20 ,

N. Khlif, N. Khraief and S. Belghith, Reinforcement Learning for Mobile Robot Navigation: An overview IEEE Information Technologies & Smart Industrial Systems (ITSIS), Paris, France, 2022, pp. 1-7 DOI: 10.1109/ITSIS56166.2022.10118362.

For several years, research shows that interest in autonomous mobile robots is increasing and it has more and more grown. Autonomous mobile robots is an object of discussion but nowadays it’s an emerging topic due to the all progress related to field like autonomous driving and UAV (drones). Integrating intelligence into robotic systems requires solving various research problems, including one of the most important problems of mobile robotic systems: navigation. Find the answers to the following three questions: What is the localisation of the robot? Where are the robot going? How can it get there? presenting the solution of mobile robot navigation problem. These questions are answered by basic navigation parts which are localization, mapping and path planning. The paper present an overview of research on autonomous mobile robot navigation. First, a quick introduction to the various features of navigation. We also discuss machine learning and reinforcement learning in mobile robotics. Furthermore, we will discuss some path planning techniques. Some future directions are also suggested.

Posted in: Applications of reinforcement learning to robots , Tagged: ,

A practical setup for control engineering courses

September 25, 2023 11:24 ,

A. Chevalier, K. Dekemele, J. Juchem and M. Loccufier, Student Feedback on Educational Innovation in Control Engineering: Active Learning in Practice, IEEE Transactions on Education, vol. 64, no. 4, pp. 432-437, Nov. 2021, DOI: 10.1109/TE.2021.3077278.

Contribution: An education innovation in control engineering using practical setups and its evaluation based on a three-year student feedback study and examination grades. Background: Based on extensive research, education\u2019s transition toward active learning and more practical experience has been shown to increase learning outcomes. Contrary to virtual and remote labs, a practical session with an individual setup for each student provides the most practical experience. Intended Outcomes: To show a positive effect on learning performance by integrating practical sessions in basic control engineering. Application Design: Presenting low cost setups that can be mass produced and adapt to the course\u2019s growing complexity. These setups are evaluated during a three-year feedback study. Findings: The developed setups increased understanding of theoretical concepts. The new methodology significantly improved students\u2019 average grades. The students\u2019 interest in control theory is triggered. This case study could guide other institutions toward successfully implementing highly individual practical sessions for large groups.

Posted in: Control Engineering , Tagged: ,