Imparting Basics in Technology through an Instructional System for Computerised Process Control

Abstract

Technological systems that incorporate computers are steadily gaining importance in our daily surroundings. In an ongoing research project at the Technion, modular learning units based on the combined study of theory, self‐learning and laboratory experiments in the fields of control systems and robotics are being developed. The learning unit ‘Computerised Process Control’ comprises the study of basic principles of computerised feedback control. The control of light intensity was chosen as the subject of the experiment. The system includes eight lamps, a sensor, amplifying circuits and an analog to digital converter. The main items studied are open‐loop control (continuous control, two‐stage control), closed‐loop control, sampling, A/D conversion, and PWM modulation. The student uses ready‐made computer programs and is given a number of assignments, such as the identification of certain sections of the program, its modification or its improvement. The study includes four classroom lessons and six hours of laboratory work. The major hypotheses that were derived from the present research are: (a) The modular learning unit makes the study of the principles of ‘hi‐tech’ subjects available to a wide population of secondary‐school pupils, while the demands on learning hours and equipment are kept to a minimum. (b) A well‐balanced learning unit can be maintained through the use of ready‐made computer programs and the involvement of the student with major parts of the relevant computer programs. This provides an illustration of the relationship existing between the computer and the control system, while keeping the part of computer work in the overall activities involved within reasonable limits. The above hypotheses were tested in the course of the experimental run of the learning unit in secondary schools (137 pupils) and in college (40 students). The evaluation was based on an achievement test, an individual practical performance test, a questionnaire and forecasts, respectively. The results demonstrate that the majority of the respondents achieved the learning objectives of the unit. Furthermore, it emerged that the students perceived the functioning of the total system as the central component of the material studied, while relating less importance to specific functions such as the attention to the computer programs. The research verifies the advantages of modular learning in the period of enormous dynamics of technological subjects on the one hand, and the limitations of teaching resources on the other hand.