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Multidisciplinary Engineering Senior Design Project 6508 Controls Lab Interface Improvement Preliminary Design Review 11/11/05. Team Members: Michael Abbott, Neil Burkell Project Sponsor: Dr. Bowman Team Mentors: Dr. Mathew, Dr. Sahin Coordinator: Dr. Phillips.
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Multidisciplinary Engineering Senior DesignProject 6508 Controls Lab Interface ImprovementPreliminary Design Review11/11/05 Team Members: Michael Abbott, Neil Burkell Project Sponsor: Dr. Bowman Team Mentors: Dr. Mathew, Dr. Sahin Coordinator: Dr. Phillips Kate Gleason College of Engineering Rochester Institute of Technology
Project Overview • Current Controls Lab: • Current System used was purchased from Feedback for use in the Controls Lab which included Analog and Digital Control Boards to be used with a DC Motor. • System was designed for technicians not students • The Digital Board is outdated • Past work from a student has shown the digital board does not work
Project Overview • Current Controls Lab: • Digital control is taught through Simulink from varying sampling time and using different methods for converting continuous to discrete transfer functions • There are no hardware experiments using digital controllers • A new Digital Board is needed for the Lab
Project Overview • Needs for the Controls Lab: • Need to use Simulink on Lab PC • Need to use current Feedback 33-100 DC Servo Motor and Power Supply • The new digital interface must link Simulink to the existing DC motor • Exploration into feasible interface concepts is needed (SD I deliverable)
Needs Assessment • System must interface Simulink to the motor • Capture experimental results accurately • User friendly for the students • Change sampling time easily for student learning • Use existing equipment • Be expandable for future labs or projects • Have a finished product by the end of Winter quarter • Protected from students but also be accessible to be fixed
Requirements Developed • The Requirements of the Project are as follows: • The system shall interface MATLAB/Simulink with the Feedback Mechanical Unit (33-100 Servo Motor) already used in the Controls Laboratory. • The user shall input their desired Simulink block diagram in Simulink/MATLAB which will control the 33-100 Servo Motor using the MATLAB Real-Time Workshop. • The sampling time of the system shall be easily changeable by the user from 1 ms to 300 ms. • The system interface will return real-time data from the 33-100 Servo Motor to Simulink/MATLAB for analysis and modification of new outputs to control the motor according to Simulink Block Diagram. • The system interface shall have 4 additional digital inputs/outputs, 1 additional analog output, and 7 differential analog inputs beyond the requirement for control of the 33-100 Servo Motor which may be used in other applications.
Requirements Developed • The Requirements of the Project (continued) • The system interface will acquire speed and position of the motor to be used for processing. • Analog inputs shall have a resolution of 16 bits and a range of +10V to -10V. • Analog outputs shall have a resolution of 16 bits and a range of +10V to -10V. • The system interface will be covered to prevent damage/access from lab users. • The system shall use the existing Feedback Power Supply for powering the 33-100 Servo Motor. • The system shall be able to perform the functions listed in current Controls Lab 8 including effects of sampling time, continuous to discrete conversion, and designing a discrete controller with specifications
Block Diagram of MathWorks Software Organization MATLAB Simulink Real-Time Target Real-Time Workshop Digital Controller
Feedback Power Supply Lab PC with Matlab and Simulink Gnd, +-15V, 5V Communication System Interface Feedback 33-100 DC Servo Motor Analog to Motor +-8V to PA(+ve,-ve) Analog from Motor Tachogenerator +-8V Digital from Motor, 6 Grey Code + Index for Position Overall System Diagram
PA +ve, PA –ve, Tachogenerator +-, Grey code Position indicator Mechanical Unit 33-100
Analysis & Synthesis of Design • Multiple Concepts were developed • Using an Analog Devices DSP Development Kit • Using a National Instruments USB Data Acquisition Board • Writing a driver to allow Matlab Real Time Workshop to communicate with board • Using NI Labview Simulation Interface Toolkit Importing Simulink into NI LabVIEW and then running experiments in LabVIEW on PC based DAQ card or external DAQ target • Using a National Instruments or Measurement Computing Data Acquisition PCI Card • Using xPC Target in Matlab to control a PC with I/O Capability
Analysis & Synthesis of Design • Concept 1: Analog Devices DSP Development Kit Analog Devices EZ-KIT
Analysis & Synthesis of Design • Concept 1 Feasibility: Analog Devices DSP Development Kit • Need DSPDeveloper software to interface Simulink’s Real Time Workshop with DSP boards • DSPdeveloper requires outdated versions of Matlab, Simulink, and VisualDSP • With software communication works very well with Audio Video DSP Development Kit • System Interface would be portable and could be used in other laboratories • None of the available development kits met our I/O requirements
Analysis & Synthesis of Design • Concept 2: National Instruments USB DAQ Board NI USB DAQPAD
Analysis & Synthesis of Design • Concept 2 Feasibility: National Instruments USB DAQ Board • Board has necessary I/O Capabilities • System Interface would be portable and could be used with any other PC with Labview • Not supported by Simulink’s Real Time Workshop • Information from MathWorks states that using Simulink with USB is very difficult if not impossible • Labview Simulation Interface Toolkit could be used to convert Simulink Diagram to a Labview DLL but would require student’s knowledge of Labview programming to interface the device
Analysis & Synthesis of Design • Concept 3: National Instruments/Measurement Computing PCI DAQ Card
Analysis & Synthesis of Design • Concept 3 Feasibility: National Instruments/Measurement Computing PCI DAQ Card • PCI Card meets all requirements for I/O’s • PCI Card is supported by Simulink and Real Time Workshop • No additional software would need to be purchased • Additional breakout hardware would be necessary • System Interface would not be portable • Only NI cards supported by MathWorks are E-Series (top of the line $$) • Measurement Computing PCI Card is cheaper
Analysis & Synthesis of Design • Concept 4: Using xPC Target in Matlab to control a PC with I/O Capability
Analysis & Synthesis of Design • Concept 4: Using xPC Target in Matlab to control a PC with I/O Capability • 5 Different PC configurations supported by MathWorks were explored: • xPC Targetbox from MathWorks with needed I/O’s • General Standards PC/104 Board with needed I/O’s • Real Time Devices PC/104 Board with needed I/O’s • Dell PC with PCI DAQ Card from National Instruments or Measurement Computing • Shuttle Barebones PC with PCI DAQ Card from National Instruments or Measurement Computing
Analysis & Synthesis of Design • Concept 4 Feasibility: Using xPC Target in Matlab to control a PC with I/O Capability • Need to add xPC Target Toolbox to MathWorks license • Each configuration is already supported by MathWorks • Each configuration would have the necessary I/O Configuration • System interface would be portable • Expandable for other projects and labs • Each configuration is very different in price per seat
BOM & Costs Concepts 1-3 Bill of Materials and Lead Times
BOM & Costs Concept 4 Bill of Materials and Lead Times
BOM & Costs Concept 4 Bill of Materials and Lead Times (Continued)
BOM & Costs • Bill of Materials common to all concepts: • Prototype Board $4.29 • 34-Way Ribbon Cable Male Connector $3.64 (50 day lead time)
Our Recommendation for Implementation • Concept 4 with a PC104 board from Real Time Devices or the Shuttle PC with a PCI DAQ Card from either NI or Measurement Computing covers all of the needs and is most feasible for implementation by the end of winter quarter • Lowest cost per seat • Portable interface • Supported by MathWorks • Expandable
Anticipated Design Challenges/Risk • Risks: • Lead time on parts • Availability of connectors • Design Challenges: • Hardware compatibility issues • Wiring I/O from interface to motor • Organizing received data from interface