Implementation And Evaluation Of A Linear Axis Rapid Development System

Abstract

Abstract NOTE: The first page of text has been automatically extracted and included below in lieu of an abstract Implementation and Evaluation of a Linear Axis Rapid Development System Abstract In most control courses the topic of feedback control is introduced at a theoretical level. A typical assignment, for example, is to design a controller (i.e., compute controller gains) to regulate the position of a linear axis given a very simple model of the linear axis. The student may conduct a simple simulation; however, they will probably not be able to implement the controller on physical hardware. In this situation the student misses opportunities to 1) explore the effects saturation, quantization, nonlinear friction, and sample period have on their controller and 2) investigate real physical results. These opportunities are lost due to the fact that the time required for the student to interact with the hardware is prohibitive in a traditional semester course. This paper presents a Linear Axis Rapid Development System (RDS), based on Simulink, which provides the student with a tool to explore all phases of controller development after the theoretical work is complete. When the student has an algorithm that is ready to implement, they encode the algorithm as a subsystem in Simulink. The controller inputs and outputs, along with their engineering units, are carefully specified. The student then utilizes the Linear Axis RDS to analyze the controller. The Linear Axis RDS has three modes: simulation, emulation, and implementation. In the simulation mode the student simulates a linear axis system that includes their controller and detailed models of the interface hardware and linear axis. In the emulation mode, the simulation is performed on the computer hardware that will implement the controller. In this mode the student can ensure their algorithm will run in real time (i.e., the algorithm’s execution time is less than the sample period). In the implementation mode, the controller is deployed on the hardware system and experimental data is gathered. This paper presents the results of the implementation of the linear axis RDS in a manufacturing automation course and initial usability studies, aimed at assessing its effectiveness as a learning tool. Introduction The process of designing a controller to govern the actions of a piece of equipment requires careful controller algorithm design and precise tuning of the controller parameters. For a student, the implementation of a controller on a physical system can be complicated and time consuming, and can distract from controller design and analysis. A software program, which minimizes the amount of effort required by the student to implement a controller, is proposed in this paper. This software program is called a Rapid Development System (RDS). The goal of the RDS is to allow the student to remain focused on controller design and analysis. This is done by creating an environment where the software can be rapidly reconfigured to integrate the student’s controller. There are three modes of controller operation used to analyze the controller performance: simulation, emulation, and implementation. In the simulation mode the student simulates a linear axis system that includes their controller and detailed models of the interface hardware and linear axis. In the emulation mode, the simulation is performed on the computer hardware that will