SSN – PKM1 Design and Realization of a 100G Parallel Kinematic Manipulator A Major Qualifying Project Report submitted to the Faculty of the WORCESTER POLYTECHNIC INSTITUTE in partial fulfillment of the requirements for the Degree of Bachelor of Science by ________________________ ________________________ M. Spenser Brouwer John W. Cushion ________________________ ________________________ Elizabeth M. De Zulueta Joshua L. Janssen ________________________ Sean F. Townsend Date: April 25, 2012 Approved: April 26, 2012 _____________________ Professor Stephen S. Nestinger Parallel Kinematic Manipulator Submitted by: Spenser Brouwer John Cushion Elizabeth De Zulueta Joshua Janssen Sean Townsend Submitted to: Professor Stephen Nestinger April 26, 2012 Abstract The goal of this project was to design, fabricate and implement a parallel kinematic manipulator robot with open architecture to be used in the Industrial Robotics course, ME/RBE 4815, curriculum for inverse kinematics and other classroom projects. The robot was designed using solid modeling software and fabricated in the WPI machine shop with use of computer aided manufacturing techniques. A programming architecture was also developed in concert with the mechanical-electrical system to allow control of the robot via a touchscreen GUI. Table of Contents Abstract ................................................................................................................................ i Table of Contents ................................................................................................................ ii Table of Figures .................................................................................................................. v 1. Introduction ............................................................................................................... 1 1.1 Project Statement................................................................................................... 1 1.2 Report Layout ........................................................................................................ 1 2 Background ................................................................................................................... 3 2.1 History of Parallel Robotics .................................................................................. 3 2.2 Three-Arm Parallel Kinematic Manipulator ......................................................... 5 2.3 Four Arm Parallel Kinematic Manipulator ........................................................... 6 2.4 Summary ............................................................................................................... 7 3 Methodology ................................................................................................................. 9 4 System Goals and Requirements ................................................................................ 10 4.1 Mechanical Design Constraints ........................................................................... 10 4.2 Target Users and Audience ................................................................................. 11 5 System Design Evaluation and Prototyping ............................................................... 11 5.1 Programming for Proof of Concept ..................................................................... 13 5.2 Summary ............................................................................................................. 14 6 Kinematics and Dynamic Modeling ........................................................................... 15 ii 6.1 Required Torque for 100G Acceleration ............................................................. 17 7 System Design and Manufacturing............................................................................. 18 7.1 Design of Support Table ..................................................................................... 29 7.2 Electrical System Design .................................................................................... 31 7.2.1 Electrical System Requirements .................................................................... 31 7.2.2 Electrical System Layout ............................................................................... 32 7.2.3 Embedded Microcontroller Selection ............................................................ 34 7.2.4 Interface Board............................................................................................... 41 8 Software Architecture ................................................................................................. 46 8.1 Computer ............................................................................................................. 46 8.2 Modes of Operation ............................................................................................. 46 8.2.1 Graphical User Interface ................................................................................ 46 8.2.2 Touch Screen Considerations ........................................................................ 49 8.2.3 External control .............................................................................................. 50 8.3 Open-Architecture API ....................................................................................... 50 9 Project Summary ........................................................................................................ 53 9.1 Project Accomplishments .................................................................................... 53 9.2 Economic Considerations .................................................................................... 55 9.3 Health/Safety Considerations .............................................................................. 55 9.4 Reliability Considerations ................................................................................... 56 iii 9.5 Social Impact ....................................................................................................... 56 9.6 Use of Standards.................................................................................................. 57 10 Future Work ............................................................................................................ 58 10.1 Mechanical Recommendations ........................................................................ 58 10.2 Electrical Recommendations ........................................................................... 58 10.3 Computer Recommendations .......................................................................... 59 11 Conclusions ............................................................................................................. 61 Bibliography ..................................................................................................................... 64 Appendix A – Weight Analysis of Subassemblies ........................................................... 65 Appendix B – Four-arm Inverse Kinematics .................................................................... 68 Appendix C – Embedded Application Code ..................................................................... 71 Appendix D – Instruction on How to Install Maple IDE .................................................. 76 iv Table of Figures Figure 1 - ABB FlexPicker ................................................................................................. 6 Figure 2 – Snapshots of the miniature acrylic prototypes................................................. 12 Figure 3 - System Parameter Definitions .......................................................................... 15 Figure 4 - Torque Profile along the Z-axis ....................................................................... 18 Figure 5. Initial Arm Design ............................................................................................. 19 Figure 6 - Initial Connection Design Concept .................................................................. 20 Figure 7 - Motor Mount Base ........................................................................................... 21 Figure 8 - Final Base Assembly (with Motor Supports) ................................................... 22 Figure 9 - Driver Arm Assembly ...................................................................................... 23 Figure 10 - Final Drive Arm Design ................................................................................. 24 Figure 11 - U-Joint Connection Design ............................................................................ 25 Figure 12 - Final U-joint Assembly .................................................................................. 25 Figure 13 - Arm Assembly ............................................................................................... 26 Figure 14- Subassemblies during epoxy setting ............................................................... 27 Figure 15 - Platform Assembly ......................................................................................... 28 Figure 16 - Final Platform Assembly................................................................................ 28 Figure 17 - Final Robot Assembly, as built ...................................................................... 29 Figure 18 - Final Support Frame Design .......................................................................... 30 Figure 19: Electrical Schematic of Entire System ...........................................................