An intelligent tutoring system for computer numerical control programming
Qinbo Li, Sheng‐Jen Hsieh · International journal of engineering education · 2019
G-code is the language used to control computer numerical control (CNC) machines. Although most CAD/CAM softwarecan generate G-code based on a design and machine tools needed, the ability to understand G-code is valuable, especiallywhen a machining job does notrun smoothly.Intelligent tutoring systems (ITS) have been shown to be successfulin helpingstudents to learn programming. However, G-code is different from general purpose computer programming languages.CNC programming also requires that students master many hardware-related facts and concepts, such as cutting speedand feed rate, and tools for several types of drilling. We built a web-based ITS for CNC programming called CNC-Tutor,and proposed a data-driven approach to generate proper hints and feedback during students’ problem-solving process.The approach is based on finding past submissions that are most similar to a student’s solution. The similarity is measuredusing a ‘‘behavior & machine state distance’’ metric. The system was evaluated by 93 undergraduate students. Resultssuggest that the design is instructionally effective, and that students’ subjective impressions of the system were positive. Italso appears that CNC Tutor‘s explanations and feedback are a good fit for active, visual learners.