Using a DC solenoid in a closed-loop position control system to teach control technology

A DC solenoid that is normally operated in two positions, is used to implement a closed-loop, position control system. The laboratory work supports and reinforces material presented in the classroom. This laboratory activity takes place in a cooperative learning environment, each group being populated by students from the Electronic & Computer Technology, the Manufacturing Technology and the Aeronautical Technology Department. Students are initially given a general positioning problem with few restrictions. Then, by adding constraints and making suggestions, they determine that a DC solenoid is a viable solution. As the students evaluate the system, they recognize that without 'the mathematical tools that they are acquiring in 'class, their task is very difficult or impossible. The series of experiments enable students to learn more about: (a) modeling, (b) block diagram representation, (c) instrumentation and data acquisition, (d) component characterization, (e) frequency response testing (f) analysis, (g) computer simulation using MATLAB/SIMULINK, (h) controller design, (i) implementation of the controller using op-amps, and finally (j) complete system performance verification. As a result, students develop a good connection between the theory and application, and recognize the importance of team work and collaboration. They are amazed at their ability to transform a two-position device, jokingly referred by them as bang-bang, into a gentle-moving system that goes to any intermediate position.