DC Motor-Clutch-Generator Control Workstation Senior Project Report Simon Benik and Adam Olson Advisor: Dr. Gary Dempsey EE451 Senior Capstone Project 16 May 2006Abstract: This senior project is the design of a motor-clutch-generator controls workstation. The plant of the system is the motor-clutch-generator. The motor will be attached to an electrical clutch, with the other end of the clutch being attached to another DC motor, which will act as a DC generator-load disturbance. The clutch can be engaged and disengaged such that the plant will change, and the controller must be able to compensate for these changes. There is also a resistor that can be applied to the generator to vary the load even more. This plant is controlled with software that is implemented on the EMAC 80515 development board using a mixture of assembly and C programming language programming. Also, non-linear modeling techniques are used to create an accurate simulation model of the physical system in Simulink. Interfacing between Simulink and the controller is accomplished.Table of Contents Introduction ……………………………………………………….…Page 1 System Description……………………………………………….…..Page 2 Project Subsystems…………………………………….……...…Pages 2 - 4 Preliminary Work as of First Semester………...….……......…Pages 4 – 7 Final Work Software…………………………………………….……..Pages 8 - 9 Hardware...……………………………………..…….….Pages 9 - 10 Modeling………………………………………………..Pages 10 - 13 Model Analysis….……………………………….…......Pages 13 - 18 Controller Designs………………………...……….…..Pages 19 - 21 Conclusion and Recommendations……………………...…………Page 22 Appendix I List of Sources…………………….…………………………Page 23 Appendix II Equipment …………………………...………………………Page 23 Appendix III Project Specifications……………………………………Pages 23-25 Appendix IV Hardware schematics…………………………………Page 25Table of Contents (Continued) Appendix V Matlab controller/model code……………...…………..Page 25 – 28 Appendix VI Known Bugs……………………………………………...Page 28 NOTE: Appendixes A, B, C, and D can be located on the CD included with this report. Appendix A Mini-project Material Appendix B Software Code Appendix C Diagram of Physical System Appendix D Flowcharts1 Introduction: The DC motor-clutch-generator control workstation is a project that was thought up by Dr. Gary Dempsey as expansion of the senior mini project that was done first semester senior year. For this mini project (see appendix A) there is a single motor that is modeled in Simulink and it is assumed to be linear in functionality. A microcontroller determines the motor’s effective voltage with the use of a pulse width modulated (PWM) signal. Based on the simulated model, we created a simple closed loop function that will adjust a PWM signal to maintain a set RPM when the motor as a load disturbance is added. The physical system, shown in figure 1-1, of the DC motor-clutch-generator control workstation contains the same motor used in the mini project, but now it is attached to another motor, through an electronic clutch, that will function as a generator. There is also a resistor hooked up with a relay across the terminals of the generator to vary the load of the system even more. The software part of the project expands off of the mini project. Serial communication, a graphical user interface (GUI), and additional controller modes have been added on top of the previous work. The GUI is programmed in Matlab and uses RS-232 communication to connect to the micro controller. This GUI is able to observe the RPM of the motor, in real time, and send variables to change values for the various closed loop controllers. System identification is used to analyze the model in Simulink, and this analysis is used to design the controllers. Figure 1-1: Physical system without relay and generator resistor2 System Description: Goals of the project are: • A plant controller implemented in C language with the EMAC 80515 development board. • A user interface that allows for changing control parameters and for motor control; as well as allowing the display of real time operation data. • Serial communication between the EMAC 80515 development board and a PC using an RS232 serial interface for data sharing. • Non-linear modeling of the physical system using control theory, Simulink, and Matlab. • A graphical user interface (GUI) in Simulink for the purpose of easy manipulation of the model for simulation and its data. The project consists of three primary subsystems. The first subsystem is the physical system. This includes the DC motor, the electronic clutch, and the DC generator with its load varied by a relay. The second subsystem is the Simulink and Matlab modeling. This is where a mathematical model is created based on data collected from the real system. This model is non-linear in order to imitate the real system as best as possible. Additionally, control methods are designed and evaluated in Simulink before they are implemented in the third subsystem. A GUI is created as well for interfacing with the third subsystem over a serial connection. The third subsystem is the software based controller that is implemented on the EMAC 80515 development board. This subsystem’s functions are to allow the user to set control parameters, display the physical system’s operation status such as velocity, and also to use control algorithms and feedback data to accurately control the physical system with its PWM signal which will drive the motor. Moreover, the EMAC 80515 development board was programmed to communicate with a PC running Simulink through serial communication. These systems are combined for an overall system block diagram. The Physical Subsystem The block diagram of the motor-clutch-generator workstation, with subsystems labeled for reference, is shown in figure 4-1. The motor subsystem consists of the Pittman DC motor with its rotary encoder and the