Current Search:  PID controllers (x)

View All Items

  • CSV Spreadsheet
(1 - 4 of 4)
Trajectory control of a new class of CNC machine tools
Title
Trajectory control of a new class of CNC machine tools.
Creator
Xiu, Daoxi., Florida Atlantic University, Masory, Oren, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
One emerging application of parallel manipulators is to use them as CNC (Computerized Numerical Controlled) machine tools and recently several prototypes of such CNC machines have been developed, all based on hexapod machine--a type of parallel manipulators similar to a Stewart platform. The goal of this research is to develop an effective control scheme, cross-coupling control, for this type of CNC machine tools, which will reduce the contouring errors and thus further enhance their...
Show moreOne emerging application of parallel manipulators is to use them as CNC (Computerized Numerical Controlled) machine tools and recently several prototypes of such CNC machines have been developed, all based on hexapod machine--a type of parallel manipulators similar to a Stewart platform. The goal of this research is to develop an effective control scheme, cross-coupling control, for this type of CNC machine tools, which will reduce the contouring errors and thus further enhance their advantages. This dissertation describes the research work as follows. Firstly. based on the analysis of the kinematics and dynamics, a PID (Proportional-Integral-Derivative) controller was designed for each leg of the hexapod CNC machine. Secondly, real-time contour error models were developed and verified to determine not only for the calculation of the contour errors of the hexapod CNC machine but also for the general case of any machine tools. Thirdly, the contour errors of the hexapod CNC machine were investigated for a conventional PID controller. The results indicate that the accuracy of the hexapod machine is better than the conventional CNC machine tools even for mismatched axes and load exertion. Finally, a cross-coupling control scheme was proposed for the purpose to enhance the contour accuracy of this new type of hexapod CNC machine tools. A cross-coupling controller design for a 2-DOF platform was performed to provide the guidelines. Then, a cross-coupling controller for the new type of hexapod CNC machine tools was designed by feeding back the contour error to each axis. The efficiency of the proposed cross-coupling controller was verified through simulations. The result shows that the proposed cross-coupling controller is very effective in reducing the contouring errors. While cross-coupling controllers were originally proposed for conventional CNC machine tools, this research is the first attempt of expanding this concept to the new type of hexapod CNC machine tools.
Show less
Date Issued
1998
PURL
http://purl.flvc.org/fcla/dt/12576
Subject Headings
Machine-tools--Numerical control, Manipulators (Mechanism), PID controllers
Format
Document (PDF)
Dynamic simulation and control of an autonomous surface vehicle
Title
Dynamic simulation and control of an autonomous surface vehicle.
Creator
VanZwieten, Tannen S., Florida Atlantic University, Leonessa, Alexander, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
Autonomous Surface Vehicle (ASV) research and development is inspired by the navigating and communicatiog challenges of Autonomous Underwater Vehicles (AUVs). The development objective is to provide real time positioning of and communication with AUVs through the air-sea interface. Despite extensive research on AUVs, the ASV has had limited research. The NAVY's desire to make AUV's defense capabilities realizable adds to the project's appeal. Guidance and control play an integral part in the...
Show moreAutonomous Surface Vehicle (ASV) research and development is inspired by the navigating and communicatiog challenges of Autonomous Underwater Vehicles (AUVs). The development objective is to provide real time positioning of and communication with AUVs through the air-sea interface. Despite extensive research on AUVs, the ASV has had limited research. The NAVY's desire to make AUV's defense capabilities realizable adds to the project's appeal. Guidance and control play an integral part in the ASV's success, motivating this thesis work. The overall vehicle dynamics were modeled and numerically simulated for 3 DOF lateral motion. These are development tools for the testing and tuning of PID and adaptive control algorithms. The results show the adaptive controller to be advantageous in terms of tuning, robustness and tracking performances. It uses a single layer neural network that bypasses the need for information about the system's dynamic structure and characteristics and provides portability.
Show less
Date Issued
2003
PURL
http://purl.flvc.org/fcla/dt/13081
Subject Headings
Hydrodynamics, Adaptive control systems--Computer simulation, PID controllers--Computer simulation, Neural networks (Computer science)
Format
Document (PDF)
adaptive computed torque controller for the I.B.M. Electric Drive Robot
Title
An adaptive computed torque controller for the I.B.M. Electric Drive Robot.
Creator
Miller, Lee Wayne., Florida Atlantic University, Pajunen, Grazyna, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description
The I.B.M. Electric Drive Robot (E.D.R.) is a six-link manipulator originally controlled by a classical analog P.I.D. controller. Its performance is not satisfactory because of its poor tracking capabilities and a considerable vibration during arm movement. This is the central motivation for designing an adaptive computed torque controller for this system. In order to accomplish this the physical model of the robot is first reparameterized such that it is linear with respect to a set of...
Show moreThe I.B.M. Electric Drive Robot (E.D.R.) is a six-link manipulator originally controlled by a classical analog P.I.D. controller. Its performance is not satisfactory because of its poor tracking capabilities and a considerable vibration during arm movement. This is the central motivation for designing an adaptive computed torque controller for this system. In order to accomplish this the physical model of the robot is first reparameterized such that it is linear with respect to a set of uncertain parameters. Once this is accomplished the adaptive controller is then formulated. Next methods of computer simulation are developed and employed. These simulation results show the superior performance of the proposed scheme over both a classical computed torque controller and the current P.I.D. controller.
Show less
Date Issued
1990
PURL
http://purl.flvc.org/fcla/dt/14612
Subject Headings
Adaptive control systems--Computer simulation, PID controllers--Computer simulation, Robotics, Manipulators (Mechanism)
Format
Document (PDF)
Development and implementation of an adaptive controller for station keeping of small outboard-powered vessels
Title
Development and implementation of an adaptive controller for station keeping of small outboard-powered vessels.
Creator
Fisher, Aaron D., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
In this thesis multiple controllers are developed which command a small boat with twin tied outboard motors to hold a desired position. In the process of developing a controller to hold a position, controllers were first developed which follow a desired heading or path over ground with the motors outputting constant thrust. These heading and path following controllers were tuned and tested in a numerical simulation, then validated on the R/V Lee and Ocean Power vessels through sea trials in...
Show moreIn this thesis multiple controllers are developed which command a small boat with twin tied outboard motors to hold a desired position. In the process of developing a controller to hold a position, controllers were first developed which follow a desired heading or path over ground with the motors outputting constant thrust. These heading and path following controllers were tuned and tested in a numerical simulation, then validated on the R/V Lee and Ocean Power vessels through sea trials in the Atlantic Ocean. After successful path following trials were performed, station keeping algorithms were developed and tuned in the numerical simulation, now with heading and thrust of the vessel both being variables to be controlled. After tuning in the numerical simulation, the Ocean power vessel was outfitted with systems for controlling throttle and steering with sea trials conducted in the Atlantic Ocean for station keeping.
Show less
Date Issued
2010
PURL
http://purl.flvc.org/FAU/2975247
Subject Headings
Ship handling, Stability of ships, Fracture mechanics, Boats and boating, Design, PID controllers, Computer simulation
Format
Document (PDF)