Description

Using the captured pictures or videos of different kinds of the welding results which affected by the setting of the welding equipment such as using A/C or D/C and the intensity of current applied, and hand posture in holding the welding touch such as angle, distance between weldment and the welding touch, and speed. Students are required to make selection among these factors in order to achieve a better welding result. The welding result corresponding to the selections will be shown immediately and a warning message will be displayed if the selections are incorrect.

This system consists of two components: (1) the multimedia user interface; and (2) the web-based simulation system. In the user interface layout, the welding information was categorized according to three examples: Manual Metal Are Welding (MMA), Tungsten Are Gas Shield Welding (TIG) and Oxy-Acetylene Gas Welding (OA). The interface consists of two layers: Examples and subordinates of each example. There are a few interactive features in this system. Different background colours are used for different welding techniques. Flash movie clips are used to present the information. In addition, simulation element of the sub-menu is linked up with another user’s interface to demonstrate how the welding parameters interferes the welding quality.

Intended Educational Value

The major deliverable of this project is a guided welding simulation that students are required to complete the computer-based exercises prior to their hands-on practices. Upon the completion of the simulation exercise, students are able to:

• Properly use personal protective equipment for welding;
• Acquire abstract basic welding principles and techniques effectively;
• Recognize and differentiate different kinds of welding technologies;
• Understand the factors affecting the welding results; and
• Recognize some common welding equipment.

Example of Application

The system has been implemented into 2-day industrial training in welding.
Students are required to go through the system for the relevant topic such as Arc Welding before their practice in the welding booth. They are also allowed to review the parameters in the system when they are practising.

Evaluation/ Comments

In order to evaluate the outcomes, in-class trials were conducted in mid-July. Half of the students who were given the chance to try the system formed as experimental group. Before the end of the workshop, this group of students had to complete a questionnaire as to enter into the next level with regard to their understanding of the content and acquisition of practical skills. Data were compared with those collected from the control group.

Data show that the experimental group had stronger confidence in different aspects of welding techniques. It proves that the application of the expert system is helpful for students to apply the knowledge that they have learned at the training workshop. Data also show that the expert system helps students manage to acquire more knowledge.