The student designs and tunes a controller that balances a rolling ball in the course Fuzzy Control (Internet course).
Figure 1 is a photo of a laboratory rig that balances a ball—also called the cart-ball rig, and Figure 2 shows a Matlab simulator of the same rig.
Figure 1. Laboratory cart-ball rig. The control objective is to balance the ball on the top, and at the same time position the cart on the middle of the track.
Figure 2. Cart-ball simulator in Matlab. The front panel shows an animation and controller settings. Click the image to see an animation.
The control objective is to balance the ball at the top by pulling the cart back and forth. The student works with the simulator, which is built from basic Matlab functions; therefore it does not require any toolboxes. The learning objective is:
- To understand how to design a fuzzy controller up to the point of designing it yourself.
The course runs on the Internet. It uses a web based learning environment, Moodle, which organises the contents and the course schedule. The student and the teacher communicate via e-mail.
Each course module includes an assignment. The student works out the answers using the simulator and the textbook and returns the answers in Moodle. The teacher inspects the answers, gives comments, and if there are problems the teacher asks the student to correct them. An assignment is not a test, but rather a dialogue.
The course requires prior knowledge of automation, for example at the level of an introductory university course in linear control theory. The course consists of ten modules, and the nominal work load is 60 person-hours corresponding to a half course. The student decides the pace, but the course must be finished within one semester. It takes at least 8 weeks to complete the course. The course contents are: fuzzy set theory, fuzzy logic, cart-ball model, linear controller design, controller test, fuzzy linear controller, fuzzy nonlinear controller, and self-organising control.
The course runs in Moodle.