Abstract:

The basic control theory subjects are obligatory in the majority of engineering degrees, which involve a great number of students. In relation to this, one of the main problems of teaching basic control theory is the difficulty of relating the theory and practice, which has motivated many works in education and educational research [1]. This has also motivated many commercial control trainers, such as Quanser or Feedback. These trainers are quite complete solutions suitable for both first control subjects and final degree works. However, these trainers have a high cost, limiting their acquisition, and must stay in the laboratory. Because of these reasons, the number of trainers is usually small comparing with the number of students and therefore the experimental work is only limited to the laboratory.

The aforementioned problems have motivated cheaper experiments, which are usually developed by universities [2]. In addition, the use of virtual laboratories has been proposed to solve the work flexibility problem [3]. Nevertheless these systems have an only accessible workstation; hence, while one student is communicating with the virtual laboratory, the others shall wait. Furthermore, the physical interaction with the laboratory instrumentation is uniquely reduced to the connection via Internet. Previous studies have proved that it is very convenient to teach with physical and simulated unit operation experiments [4], and that the learning environment must strengthen the student learning by means of the physical interaction [5]. The work here proposed is a novel control engineering trainer, which is functional, economical, completely portable and very easy to implement in any personal computer. Thus, this novel solution combines the advantages of a physical experiment with simulation, which can be carried out in student’s home.

The proposed work is based on a DC Motor with a reduction gear. This motor is connected to a load and is controlled by a servo-controller. The servo-controller allows us to configure as voltage, current or velocity regulator. In addition, a data acquisition card (USB-6211 of National Instruments) is used to generate the control signal and to measure the encoder. Moreover, a group of virtual instruments programmed in LabView has been proposed, which contemplates the objectives of the three control subjects of the Industrial Engineering Degree (University of Castilla-La Mancha). These virtual instruments can be installed in any PC without having the software LabView. Therefore, the low cost of the control trainers (less than 1000€) and the possibility of using in any PC, allow us to equip our labs and to impart a loan program, which increase substantially increases the work flexibility of the students.

References:

[1] S. Dormido. Control learning: present and future. Annual Reviews in Control, 28(1), 115–136, 2004.
[2] C. Vibet, Control teaching via low-cost setups, IEEE Transactions on Education, 37(3), 269-270, 1994.
[3] Sanchez, J; Dormido, S; Pastor, R, et al, A Java/Matlab-based environment for remote control system laboratories: Illustrated with an inverted pendulum, IEEE Transactions on Education, 47(3), 321-329, 2004
[4] Wiesner, TF; Lan, W, Comparison of student learning in physical and simulated unit operations experiments, Journal of Engineering Education, 93(3), 195-204, 2004.
[5] Driscoll, M. P. (1994). Psychology of learning for instruction. Boston: Allyn and Bacon.

Keywords:

Teaching trainers, work flexibility, control.