robotics courses for high school students and pre-service teachers of technology ... the robot platform, programming and operating robot behaviors. ... chanical engineering, electronics and computer engineering, biotechnology, etc. In each of ...
Teaching Electronics through Constructing Sensors and Operating Robots Hanoch Taub and Igor Verner Department of Education in Technology and Science, Technion – Israel Institute of Technology, Haifa, 32000, Israel {hanocht,ttrigor}@tx.technion.ac.il
Abstract. This paper proposes an approach to integrating electronics studies in robotics courses for high school students and pre-service teachers of technology mechanics. The studies focus on building electronic sensors, interfacing them to the robot platform, programming and operating robot behaviors. The educational study shows the learners' progress in electronics, thinking and learning skills, and attitudes towards engineering. Keywords: Robotics education, electronics, learning for understanding.
1 Introduction Technology education in Israel high schools passes a reform aimed to focus it on subjects relevant for hi-tech industry and modern society, as well as to enlarge the numbers of school graduates who choose to study engineering at universities and colleges. The priority trends of the reform are: -
Development of systems thinking as a general outlook of communication and control processes in natural, technological and social systems. Project based learning, as a catalyst of creative thinking, learning motivation, selflearning, communication and practical skills. Interdisciplinary connections that provide broad perspective, analogical thinking, and foster development of values and self-identity.
The new technology education curriculum includes a number of tracks such as mechanical engineering, electronics and computer engineering, biotechnology, etc. In each of these tracks the studies consist of three subjects: introductory course, core technology course, and majoring subject. In the mechanical engineering track physics serves as an introductory course, engineering mechanics and machine control is the core subject [1], and there are several optional majoring subjects one of which is mechatronics. A number of challenges aroused when implementing mechatronics in schools. Two of them are directly related to the electronics studies required by the subject: (1) the traditional teaching methods which are used at the electronics engineering track do not fit the needs of the integrated subject and new teaching methods should be developed. (2) The majority of teachers of mechatronics are mechanical engineers with limited background in electronics. J.-H. Kim et al. (Eds.): FIRA 2009, CCIS 44, pp. 255–261, 2009. © Springer-Verlag Berlin Heidelberg 2009
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Our study was conducted in the framework of Master's thesis performed by Taub under the guidance of Verner. It addresses the above mentioned challenges and proposes a possible approach to integrating electronics studies in robotics courses for high school students and pre-service teachers of technology/mechanics. This paper presents results of implementation and evaluation of the proposed approach.
2 Didactical Principles of Teaching Mechatronics Educational mechatronics relies on the theory of constructionism developed by Seymour Papert [2]. This theory is based on the constructivist approach to learning and considers the situation when the learner is involved in making an artifact which serves as an object to think with and to communicate about. Learning by making artifacts occurs only in constructivist learning environments (CLEs). The methodology of design of CLEs is based on the principles of the activity theory [3-4]. The activity theory provides a framework for studying learners' behaviors, processes of their mental and social development, and instructional tools given to the learners. This theory is relevant for our study, in which electronics is taught in the mehatronic environment through hands-on experimentation with sensors and designing, building and programming robots. The central issue in developing a constructivist curriculum is defining instructional objectives, i.e. the capabilities which the learner is expected to demonstrate at the end of the studies. The objectives serve for directing the learning process and assessing its outcomes. Traditionally, learning objectives related to different levels of performance are defined by Bloom's taxonomy [5]. Recently the Bloom's taxonomy has been updated to fit the needs of modern education, particularly technology education [6]. We found the updated taxonomy relevant to our study and used it for developing learning objectives of the proposed course. The important updates made in the revised taxonomy include the following: 1. "Create" becomes the category which expresses the highest cognitive level of performance. The meaning of create here is " to form a coherent or functional whole; reorganizing elements into a new pattern or structure through generating, planning, or producing" [6]. This fits the constructionist approach which focuses on learning by doing and creating artifacts. 2. The taxonomy categories integrate objectives related to cognitive and psychomotor domains. This is relevant to the interdisciplinary learning activities which occur in the mechatronics course. The revised taxonomy has a matrix structure with the knowledge dimension as the vertical scale and the cognitive process dimension as the horizontal scale. The four knowledge categories are: factual knowledge, conceptual knowledge, procedural knowledge, and meta-cognitive knowledge. The six cognitive process categories are: remembering, understanding, applying, analyzing, evaluating, and creating. Examples of learning objectives which are designed by using the revised taxonomy matrix are given in Table 1. We designed educational objectives corresponding to all the knowledge and cognitive process categories because of the diversity of the course content and the learning activities.
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Table 1. Examples of learning objectives
Issue: Constructing Cognitive sensors, integrating process them in a category mechatronic system underand programming a standing control process.
The pupil will be capable: a. To choose a proper electronic sensor from data-sheet -Factual Knowledge. b. To interpret the link between the sensor's electronic circuit and its function -- Conceptual Knowledge. c. To foresee the output of the program by reading the sensor -- Procedural Knowledge. d. To give a presentation on electronic sensor and the principles of its operation to peers -- Meta-Cognitive Knowledge.
Mechatronics education utilizes problem and project based learning strategies that emphasize such important factors of engineering studies as challenge, curiosity, imagination, design, construction, and teamwork [7-9]. The projects foster learning motivation and facilitate the development of learning skills. In the project the learner takes responsibility for learning [10]. An example of problem based learning is a study of knowledge construction through the robot technology [11]. The conclusions of the study are that the learners: (1) create knowledge by cooperation; (2) acquire skills across science disciplines; (3) acquire technical skills; (4) develop scientific, mathematical and programming comprehension.
3 Course Syllabus and Activities The topics covered by the course are as follows: 1.
Not Quiet C or Lego MindStorms Language and Programming the robot behaviors (4 hours). 1.1 Basic commands for operating robot subsystems. 1.2 Programming and using sensors. 1.3 Questionnaire of programming problems. 2. Introduction of electricity and electronics (4 hours). 2.1 Preliminary evaluation exam. 2.2 Basic concepts. 2.3 Practicing the basic concepts, evaluation questionnaire. 3. Introducing electronic sensors (8 hours). 3.1 Sensor of light, temperature …, explanation of it principle operation and applications. 3.2 Evaluation questionnaire. 3.3 Building an electronic sensor circuit and connecting it to a robot's interface. 3.4 Programming control programs that involve the electronic sensors and manipulate the robot behavior movements. 4. Optional projects. 5. Evaluation exam. The study of all the listed topics included experiential activities. When studying the programming languages the learners programmed close-loop control operations of
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Lego robots. The students practiced basic concepts of electricity and electronics by building circuits, measuring their physical parameters, and comparing factual data with theoretical solutions. Electronic sensors were learned through the learning by doing approach. The students built different sensor circuits, interfaced them to the input of the robot, and programmed robot operations. The audio sensor circuit built by the students in the course is presented in Figure 1A. After building the sensor the students used it as a clap detector for initiating robot operation. Changeable resistor
A.
To robot
Microphones
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Fig. 1. A. Audio sensor; B. Temperature sensor mounted on the robot
Figure 1B shows the temperature sensor, its electronic circuit and power supply mounted on the mobile robot. With this robot configuration the students measured temperature and programmed the robot to detect heat sources. In addition to the sensors presented in Figure 1, the students built, interfaced and programmed light, IR, LDR, and touch sensors.
4 Educational Study The goal of our educational research was to evaluate the proposed method of teaching electronics through constructing sensors and operating robots by high school students and pre-service teachers. The research focuses on the following questions: 1. What are characteristics of the learning environment and learning activities that facilitate the acquisition of knowledge and skills in electronics required in high school robotics and mechatronics courses? 2. What effect has the practice in constructing sensors and applying them for operating robot behaviors on understanding concepts in electronics? 3. What are learner's attitudes about the proposed teaching method, outcomes, motivation and learning capability?
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The research was conducted as a multi-case study Yin[12], when the cases were follow-ups of the course given in different frameworks and to different categories of learners: -
Eleventh grade pupils studying mechatronics (N=13). Scientific extracurricular class of 9th graders (N=12). Technion students from the Department of Education in Technology and Science (N=19) participated in the course "Selected problems in design and manufacturing". Eleventh grade pupils participated in the Technion International Summer Research Program SciTech (N=4). Junior college 14th grade students (N=2) in the framework of graduation projects.
The educational research data were collected by means of knowledge and attitude questionnaires, observations, interviews; products and project reports, and course exams. Quantitative and qualitative methods were used. The quantitative study focused on evaluation of learning outcomes during the course, whereas the qualitative study analyzes the learning process. Results of the case studies were compared in order to increase the reliability of the conclusions about the proposed learning method [13]. In the phase of development of the case studies we based on Kolb's theory [14]; the constructionist approach [2]; methodology of CLE design [3-4], and the revised Bloom's taxonomy [5].
5 Findings Based on the research data we addressed the first research question and identified the following characteristics of the proposed mechatronics learning environment: -
Three levels of learning activities While building electronic sensors the learner understands its structure and the function of each of the components. When interfacing the sensor to the robot, the learner understands its functionality in terms of power consumption, communication, and control. Making experiments with the robot involves the learners' peer discourse aimed to understand the physical principles of sensor operation. - Linking the levels of learning activities by reflective analysis Through iterations of measuring characteristics of electronic circuits vs. observed robot performance parameters the students practice reflective learning skills and achieve deeper understanding of the electronics concepts. - Fostering critical thinking The practice of continual evaluation of measured values of electronics parameters by their comparison with theory-based estimations facilitates development of critical thinking. - Fostering development of higher order thinking skills By troubleshooting the robot, the learner develops ability to detect and fix technical problems in integrated systems. By designing the control programs, the learner develops programming skills. By solving the logic problems, the learner develops a logical thinking. By navigating the robot as a challengeable application, the learner develops navigation skills. By learning about the mutual relationships between the
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physical concepts, the learner develops general conception about different physical fields, gradient of the field and the common characteristics. By designing and implementing operation of the mechatronics system, the learner develops a systematic view on the system. With regard to the second research question, the formative and summative assessment showed a progress in learners' understanding the electronics concepts achieved in the courses. In order to evaluate this progress we conducted post-course tape-recorded interviews. In these interviews the learners described the principles of sensor functioning during robot operation and the physical concepts that are behind the measured parameters of the electronic sensor circuit. Data indicating the progress in understanding the electronics concepts were triangulated by means of pre-course and the postcourse questionnaires for pre-service teachers, and quizzes for school students. The average grade of the pre-service teachers rose from 59.1% to 74.1%. The school students did not have prerequisite knowledge in electronics. Assessment results indicated their significant progress in electronics studies. The average course grade based on four quizzes was 82.3%. Based on the data analysis, the progress in understanding electronics concepts can be characterized as follows: -
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By "learning by doing" activities, the learner perceived the features of electronic components that can be seen only through practical experience. For example, the learner did not control functioning of the sensor (this was done by the computer) but concentrated on the operation research and troubleshooting. Measuring values of physical characteristics while testing of robot operation helped the learner to understand the links between different electronics concepts. This way, for example, the learners comprehended the link between temperature and voltage by heating the sensor unit (diode) and measuring the output voltage of the sensor circuit, or reading appropriate values from the computer program. By integrating sensors to the robot, writing and testing the control program and presenting the project to peers, the learner developed conceptual understanding of the mechatronic system.
Learner's attitudes about the teaching method and learning outcomes, inquired by the third research question, were evaluated using an attitude questionnaire and tape recorded interviews. Our findings: -
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Most of the pre-service teachers were very positive about the teaching method and planned to use it in their teaching. As a fact, one of our former students now teaches robotics using the method. Most of the learners reported on their significant progress, achieved in the course, not only in electronics, but also in computer programming, control systems and even in mechanics. As the main factors that influenced the progress, the learners mentioned teamwork, learning by doing, the rich technological environment, involvement in the robot design, problem and projects based learning. The main motivation factors noted by the learners were: construction of the robot, joyful practice, success in all stages of robot development.
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6 Conclusion Our research shows that electronics studies can be effectively integrated in the high school robotics course and in the teacher training course. The proposed teaching method can facilitate understanding the concepts of electronics, development of higher order thinking and self learning skills, foster learner's motivation and interest in engineering. Based on the experience, we recommend further examination and implementation of the proposed teaching method in robotics education.
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