Teaching Enhanced with Simulations in Simulink

Introduction – Teaching in University

In the engineering sphere, courses are usually commenced off with introduction of formulae or equations that describe underlying principles of various theories. These equations are then transformed from printed symbols on the blackboard to actual observed occurrences in real world systems (through experiments conducted in laboratory classes). This is the teaching method that has been practised for centuries and is widely believed to be the best method by lecturers.

However, this current teaching approach can still be improved. In reality, most students find it difficult to relate the theories they learnt to the real world systems they actually see.

Figure 1 – Missing Link between Theories learnt in lectures and the Real World Applications.

This is because there are many limitations to what can be achieved in the laboratory (e.g. safety, cost). Besides, experiments are not always easy to grasp the first time doing it nor it is as straightforward as it may thought to be. An intermediate stage between these two phases is needed to ease and speed up the transition. This intermediate stage will be discussed in the next section but before that let’s see how teaching has evolved over the century and why this intermediate phase is important in this modern world.

The Evolution of Teaching

Everything evolves over time, and so is teaching. Looking back, chalkboard art (Figure on the right) was the popular method used to teach a couple of decades ago. However, there are disadvantages with this method.

• The teaching and learning process is slower.
  Lecturers have to write the notes on the blackboard and students have to copy them down. This ’2 times’ writing process impedes capability for speedier transfer of knowledge.
• Every diagram/graph/chart drawn is a sketch, not accurate, and static.
  Though lecturers may be able to draw diagrams accurately but students often misinterpret the sketches and then get baffled with their notes later on. In addition, diagrams are static and inhibit students’ capability to learn faster through visualisations.

• Explaining effects of a parameter change (in an equation) could be awful.
  Frequently, lecturers want to explain the significance of parameters in an equation to illustrate the effects they have on the real system. To achieve this, lecturers have to erase and redraw the diagram all over again, which is time wasting and painful.

As time goes by, technology advances and then comes the projector art. With the overhead projector, lecturers improved their teaching considerably. Below is the list of advantages (and disadvantages) of projector art.

• Cleaner
  Chalks are replaced with ink pens and transparencies. No more dry fingers, dusters and asthma.
• Eliminates inaccuracies
  Projector technology enables lecturers to display photocopied transparencies during lectures. This enhances visual learning through display of accurate drawings/graphs/diagrams and students will be less likely to copy down incorrect diagrams.
• Speedier learning
  
  
  With photocopied transparencies, lecturers now reduce time wastage by eliminating the need to write lots of notes or draw diagrams on the blackboard. The transparencies can also be photocopied and be distributed to the students as notes.
• (Disadvantage) Diagrams are still static
  
  
  Though accurate, the diagrams/graphs/charts are still static (i.e. no animation or simulation). This is like comparing between staring at an image and watching a movie. We tend to experience and learn more in a movie (or a series of moving images).
  

Next in the evolution timeline is through the usage of simulations. Numerous researches have been conducted and visual learning has been found to be the easiest and quickest way to learn new information. Simulations are a very good method to enhance visual learning.

Simulation in Modern Teaching

Simulation plays a critical role in modern teaching. In this present era, technology advances at an unimaginable rate (compared to that half a century ago) and is constantly keeping us on our toes (in anticipation of ‘what’s new’ down the road). The amount of information is rising, the number of professionals is increasing and new researches are published every day. However, the number of years of education in a typical University degree remains the same (4 years). This means there is higher density of information that modern students need to absorb. This highlights an important trend that educators need to take note in order to keep up with intellect’s ever-expanding sphere. Let’s see an example of a conveyor mechanism.

Conveyor Mechanism (Figure on the right)

With chalkboard art, lecturers are limited to drawing sketches and writing equations on the blackboard. Describing kinematics or the actual operation of this mechanism takes a great deal of effort.

Projectors enhance the teaching process with the ability to display an accurate representation of the mechanism immediately and how various parts are connected together. (For e.g., just by photocopying the above model onto a transparency)

However, simulation enhances the teaching process considerably. Let’s take a look at the figures below.

The figures above illustrate a virtual conveyor mechanism built in the Simulink environment. Here are some of the advantages of this model.

• With Simulink’s diverse features and capabilities, there is so much that can be achieved. A simple example shown here are the responses of the system (torque, linear and angular position) which are plotted as the simulation runs.
• Students are able to directly view how the conveyor mechanism operates when (for e.g.) a certain amount of torque is applied to the lower link. These allow them to visualize the system and relate it directly to the equations they learnt in lectures.

• Virtual model is safe, cheap and its parameters can be changed over and over again without any worries of unfortunate incidents. Students then can test and see for themselves (and learn) how the theories they learnt in lectures affect the behaviour of a system. Upon studying the system, then they can move on to the laboratory classes and relate what they discover in the simulation environment to the actual occurrences of real world systems.

• (Though no simulations here) Simulations catch attention and build interests to those who see it. This increases students’ passion for the subject they studied and hence be able to always relate their studies to what they see.
• Simulink allows lecturers to design models up to high level of complexity. Therefore, there’s almost no end to what can be designed in the Simulink environment and be shared during lectures. Simulink also enables students to link up with systems from other domains (e.g. electrical to mechanical to thermal) to test out the integration feasibility between systems.

Conclusion

In conclusion, as the phrase goes “Picture speaks a thousand words”, so is simulation in the teaching environment. With simulation, students are able to learn much more (through visual learning), as well as to understand the theories taught in lectures at a quicker rate. They’ll also be able to relate what was taught to the real engineering systems and hence increase their passion on the subject they’re learning.

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Article by James Ang, Application Engineer