SMUTNY, Lubomir
VSB - Technical University of Ostrava, Department of Control Systems and Instrumentation, Ostrava-Poruba, ZIP 708 33, Czech Republic, lubomir.smutny@vsb.cz, http://www.vsb.cz/~smu50
Abstract: Paper deals with decisive role of the laboratory experimental stands with computers for quality engineering education. Fundamental part of university education creates connection of theoretical approaches with experimental or simulation methods for verification of coincidence. Illustration of practical physical models is cardinal importance for engineering experimental exercises, for comparing of the computer simulation tasks with practical experiences and with real-time measured signals from the technological aggregates. Experimental verification of the theoretical knowledge responds to need for accelerated acquisition and adoption of "best practice" techniques and methods and it increases the quality engineering education. Experimental stands allow easy understanding principles of the aggregate parts, measurement and control devices, signals character, noise, dynamic responses and more easy crossing to the real technological systems. Some concrete examples with several instrumental laboratory stands with computers for measurement, control and diagnostic tasks will be presented with good experiences from the experimental education on the Department of Control Systems and Instrumentation TU Ostrava.
Keywords: engineering education, laboratory stand, computer, experimental exercises, practical experiences
The current rate of change in the industrial and commercial environment is expected to accelerate into the next millennium. By this way, the practical requirements will increase to involve themselves actively in continuous education and improvement. Fundamental part of university education makes connection of theoretical approaches with experimental or simulation methods for verification of coincidence. In this area has non-replaceable role an experiment with physical models, now usually link together with computers and sophisticated instruments. Illustration of practical physical models is cardinal importance for engineering experimental exercises, for comparing of computer simulation tasks with practical experiences and with real-time measured technology signals. On the Department of Control Systems and Instrumentation of TU Ostrava, we have a good tradition with joining theoretic parts of subjects (for instance Basis of Cybernetics, Measurement and Sensors, etc.) with simple or complex experimental stands for testing and comparing including computer simulation [1, 2, 3].
Basic demands for design and production of experimental stands for laboratory exercises are [5, 7, 8, 9]:
Experimental verification of theoretical knowledge responds to need for accelerated acquisition and adoption of "best practice" techniques and methods and it increases the quality engineering education.
On the Department of Control Systems and Instrumentation were designed and produced quantity of laboratory experimental stands, models and teaching aids. They are utilized for practical exercises in department specialization subjects, mainly connected with group of "devices subjects" (Measurement and sensors, Means of automatic control, Microcomputer measurement systems, Design of process systems, Signal processing, etc).
The main attention was given to the experimental model of "small air-conditioning unit" as a termo-air aggregate - TAA [2, 7, 8]. This model was produced in 15 pieces not only for Department CSI using, but also for other Departments (Technical University of Brno, Technology Faculty of Zlin).
On the Figure 1 we can see the block schema of this model TAA and on the Figure 2 is a view with one piece of model on Department CSI laboratories. Models TAA are used in series of subjects for bachelor and master level of faculty education (Automatic control, Automatic control devices, System identification, Final project, etc…).
Figure 1. Block schema of experimental model TAA (termo-air aggregate)
Figure 2. View with experimental laboratory model TAA (Termo-air aggregate)
On the Figure 3 we can see a program support example of serial communication with external microcomputer unit CTRL and personal computer PC by WinCTRL program module - PID control with 2 control outputs (temperature, flow).
Figure 3. Program support example of serial communication with external unit CTRL and PC by WinCTRL program module - PID control with 2 control outputs (temperature, flow).
On the next figures we can see other examples of experimental stands with computer PC or PLC support, which are used on Department CSI. These stands cover typical static and dynamic properties of technological equipment with continuous and discrete nature (press-air aggregate, lift, electric drive, crane as mechatronics system, etc.).
Figure 4. Press-air aggregate controls with PLC and connected to PC with SCADA/MMI program support Intouch
Figure 5. Asynchronous electric drive with controlled loading direct engine on the distributed control system with PLC (Alan Bradley) and PC
Figure 6. Assembly of the water vessels with discrete (contact) and continuous (ultrasonic) measurement of levels with PLC (Mitsubishi) and PC (with InTouch support)
Figure 7. Model of the crane as mechatronics system with optical fiber bus connected sensors of position and angle deflection, I/O unit and control board in PC.
Figure 8. Experimental stand with modeling electronic set DIGISTA and FISCHER set (model of small robot) with PC (SCADA/MMI program Control Panel)
Figure 9. Experimental stand of levitation object in magnetic field controlled by PC with very quick response (position of object is measured by noncontact proximity fibre optic sensor)
Figure 10. Stand with electric direct engine controlled with microcomputer IMC and connected by serial line RS 485 with PC (SCADA/MMI program support Control Panel)
Figure 11. Experimental stand for temperature sensor calibration (hot air calibration tunnel, small laboratory stove)
Verification of theoretical findings is important part of education process. Although increasingly significant methods are computer simulations, now typical with simulation programs aid (for instance Matlab-Simulink, SIPRO [4]), experiments with real physical models are not interchangeable. Experimental stands allow easy understanding to principles of aggregate parts, measurement and control devices, signals character, noise, dynamic responses and easier crossing to the real technological systems. Experiences from practical exercises and Projects on the Department of CSI confirm increasing motivation of students, better interconnection of theoretical knowledge with practical experiences and skills. The decisive role of the laboratory experimental stands with computers for quality engineering education were confirmed also in very good results of diploma thesis and yearly hold Student Creative Research Competition.