Current Search: Robots -- Control systems (x)
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- Title
- The visual looming navigation cue: A unified approach.
- Creator
- Joarder, Kunal., Florida Atlantic University, Raviv, Daniel, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
This research introduces a unified approach to visual looming. Visual looming is related to an increasing projected size of an object on a viewer's retina while the relative distance between the viewer and the object decreases. Psychophysicists and neurobiologists have studied this phenomenon by observing vision and action in unison and have reported subject's tendency to react defensively or using this information in an anticipatory control of the body. Since visual looming induces senses of...
Show moreThis research introduces a unified approach to visual looming. Visual looming is related to an increasing projected size of an object on a viewer's retina while the relative distance between the viewer and the object decreases. Psychophysicists and neurobiologists have studied this phenomenon by observing vision and action in unison and have reported subject's tendency to react defensively or using this information in an anticipatory control of the body. Since visual looming induces senses of threat of collision, the same cue, if quantified, can be used along with visual fixation in obstacle avoidance in mobile robots. In quantitative form visual looming is defined as the time derivative of the relative distance (range) between the observer and the object divided by the relative distance itself. The visual looming is a measurable variable. Following the paradigm of Active Vision the approach in this research uses visual fixation to selectively attend a small part of the image, that is relevant to the task. Visual looming provides a time-based mapping from a "set of 2-D image cues" to "time-based 3-D space". This research describes how visual looming, which is a concept related to an object in the 3-D world, can be calculated studying the relative temporal change in the following four different attributes of a sequence of 2-D images: (i) image area; (ii) image brightness; (iii) texture density in the image; (iv) image blur. From a simple closed form expression it shows that a powerful unified approach can be adopted in these methods. An extension of this unified approach establishes a strong relationship with the Weber-Fechner law in Psychophysics. The four different methods explored for the calculation of looming are simple. The experimental results illustrate how the measured values of looming stay close to the actual values. This research also introduces one important visual invariant $\Re$ that exists in relative movements between a camera light-source pair and a visible object. Finally, looming is used in the sense of a threat of collision, to navigate in an unknown environment. The results show that the approach can be used in real-time obstacle avoidance with very little a-priori knowledge.
Show less - Date Issued
- 1995
- PURL
- http://purl.flvc.org/fcla/dt/12416
- Subject Headings
- Robots--Control systems, Robot vision, Robot camera--Calibration
- Format
- Document (PDF)
- Title
- Derivation and identification of linearly parametrized robot manipulator dynamic models.
- Creator
- Xu, Hua., Florida Atlantic University, Roth, Zvi S., Zilouchian, Ali, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
The dissertation focuses on robot manipulator dynamic modeling, and inertial and kinematic parameters identification problem. An automatic dynamic parameters derivation symbolic algorithm is presented. This algorithm provides the linearly independent dynamic parameters set. It is shown that all the dynamic parameters are identifiable when the trajectory is persistently exciting. The parameters set satisfies the necessary condition of finding a persistently exciting trajectory. Since in...
Show moreThe dissertation focuses on robot manipulator dynamic modeling, and inertial and kinematic parameters identification problem. An automatic dynamic parameters derivation symbolic algorithm is presented. This algorithm provides the linearly independent dynamic parameters set. It is shown that all the dynamic parameters are identifiable when the trajectory is persistently exciting. The parameters set satisfies the necessary condition of finding a persistently exciting trajectory. Since in practice the system data matrix is corrupted with noise, conventional estimation methods do not converge to the true values. An error bound is given for Kalman filters. Total least squares method is introduced to obtain unbiased estimates. Simulations studies are presented for five particular identification methods. The simulations are performed under different noise levels. Observability problems for the inertial and kinematic parameters are investigated. U%wer certain conditions all L%wearly Independent Parameters derived from are observable. The inertial and kinematic parameters can be categorized into three parts according to their influences on the system dynamics. The dissertation gives an algorithm to classify these parameters.
Show less - Date Issued
- 1992
- PURL
- http://purl.flvc.org/fcla/dt/12291
- Subject Headings
- Algorithms, Manipulators (Mechanism), Robots--Control systems
- Format
- Document (PDF)
- Title
- Development of a controller for a Stewart platform.
- Creator
- Marquis, Lawrence Paul., Florida Atlantic University, Masory, Oren, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
A Stewart platform is a six degree of freedom robot manipulator with its six links arranged in a parallel configuration. A dynamic model for the plant of each link, which consists of an amplifier, an electrohydraulic servo valve, and a hydraulic actuator, is found from open-loop step and frequency responses. To determine a model for the complete closed loop system, integrators located in the link input and feedback paths were added to the plant's model. PID controllers were designed to...
Show moreA Stewart platform is a six degree of freedom robot manipulator with its six links arranged in a parallel configuration. A dynamic model for the plant of each link, which consists of an amplifier, an electrohydraulic servo valve, and a hydraulic actuator, is found from open-loop step and frequency responses. To determine a model for the complete closed loop system, integrators located in the link input and feedback paths were added to the plant's model. PID controllers were designed to increase the system's bandwidth. Once control of the individual links was achieved, control algorithms were developed to control the motion of Stewart platform. The algorithm would move the platform through its initialization sequence, then control platform velocity, as dictated by the user.
Show less - Date Issued
- 1992
- PURL
- http://purl.flvc.org/fcla/dt/14849
- Subject Headings
- Manipulators (Mechanism), Robots--Control systems
- Format
- Document (PDF)
- Title
- Self-Contained Soft Robotic Jellyfish with Water-Filled Bending Actuators and Positional Feedback Control.
- Creator
- Frame, Jennifer, Engeberg, Erik, Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
This thesis concerns the design, construction, control, and testing of a novel self-contained soft robotic vehicle; the JenniFish is a free-swimming jellyfish-like soft robot that could be adapted for a variety of uses, including: low frequency, low power sensing applications; swarm robotics; a STEM classroom learning resource; etc. The final vehicle design contains eight PneuNet-type actuators radially situated around a 3D printed electronics canister. These propel the vehicle when inflated...
Show moreThis thesis concerns the design, construction, control, and testing of a novel self-contained soft robotic vehicle; the JenniFish is a free-swimming jellyfish-like soft robot that could be adapted for a variety of uses, including: low frequency, low power sensing applications; swarm robotics; a STEM classroom learning resource; etc. The final vehicle design contains eight PneuNet-type actuators radially situated around a 3D printed electronics canister. These propel the vehicle when inflated with water from its surroundings by impeller pumps; since the actuators are connected in two neighboring groups of four, the JenniFish has bi-directional movement capabilities. Imbedded resistive flex sensors provide actuator position to the vehicle’s PD controller. Other onboard sensors include an IMU and an external temperature sensor. Quantitative constrained load cell tests, both in-line and bending, as well as qualitative free-swimming video tests were conducted to find baseline vehicle performance capabilities. Collected metrics compare well with existing robotic jellyfish.
Show less - Date Issued
- 2016
- PURL
- http://purl.flvc.org/fau/fd/FA00004656, http://purl.flvc.org/fau/fd/FA00004656
- Subject Headings
- Adaptive control systems, Artificial intelligence, Autonomous robots, Computational intelligence, Robotics
- Format
- Document (PDF)
- Title
- Design and implementation of a control system for a laser-tracking measurement system.
- Creator
- Bai, Ying., Florida Atlantic University, Roth, Zvi S., Zhuang, Hanqi, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
To assess and evaluate the performance of robots and machine tools dynamically, it is desirable to have a precision measuring device that performs dynamic measurement of end-effector positions of such robots and machine tools. Among possible measurement techniques, Laser Tracking Systems (LTSs) exlnbit the capability of high accuracy, large workspace, high sampling rate, and automatic target-tracking,. and thus are well-suited for robot calibration both kinematically and dynamically. In this...
Show moreTo assess and evaluate the performance of robots and machine tools dynamically, it is desirable to have a precision measuring device that performs dynamic measurement of end-effector positions of such robots and machine tools. Among possible measurement techniques, Laser Tracking Systems (LTSs) exlnbit the capability of high accuracy, large workspace, high sampling rate, and automatic target-tracking,. and thus are well-suited for robot calibration both kinematically and dynamically. In this dissertation, the design and implementation of a control system for a homemade laser tracking measurement systems is addressed and calibration of a robot using the laser tracking system is demonstrated Design and development of a control system for a LTS is a challenging task. It involves a deep understanding of laser interferometry,. controls, mechanics and optics,. both in theoretical perspective and in implementation aspect. One of the most important requirements for a successful design and implementation of a control system for the LTS is proper installation and alignment of the laser and optical system,. or laser transducer system. The precision of measurement using the LTS depends highly on the accuracy of the laser transducer system, as well as the accuracy of the installation and alignment of the optical system. Hence, in reference to the experimental alignment method presented in this dissertation, major error sources affecting the system measurement accuracy are identified and analyzed. A manual compensation method is developed to eliminate the effects of these error sources effectively in the measurement system. Considerations on proper design and installation of laser and optical components are indicated in this dissertation. As a part of the conventional control system design, a dynamic system model of the LTS is required. In this study, a detailed derivation and analysis of the dynamic model of the motor gimbal system using Lagrange-Euler equations of motion is developed for both ideal and complete gimbal systems. Based on this system model,. a conventional controller is designed. Fuzzy Logic Controllers (FLC) are designed in order to suppress noise or disturbances that exist in the motor driver subsystem. By using the relevant control strategies. noise and disturbances present in the electrical control channels are shown to reduce significantly. To improve the system performance further, a spectrum analysis of the error sources and disturbances existing in the system is conducted. Major noise sources are effectively suppressed by using a two-stage fuzzy logic control strategy. A comparison study on the performances of different control strategies is given in this dissertation, in reference to the following: An ideal system model, a system with a long time delay, a system with various noise sources and a system model with uncertainties. Both simulation and experimental results are furnished to illustrate the advantages of the FLC in respect of its transient response, steady-state response, and tracking performance. Furthermore, noise reduction in the laser tracking system is demonstrated. Another important issue concerning a successful application of the LTS in the calibration of a robot is the estimation of system accuracy. Hence, a detailed analysis of system accuracy of the LTS is presented in this worL This analysis is also verified by experimental methods by means of tracking a Coordinate Measuring Machine available in the FAU Robotics Center. Using the developed LTS, a PUMA robot in the FAU Robotics Center is calibrated. The results obtained are confirmative with the data available in the literature. In summary, the proposed methodology towards the design and implementation of a control system for LTSs has been shown to be successful by performing experimental tracking and calibration studies at the FAU Robotics Center.
Show less - Date Issued
- 2000
- PURL
- http://purl.flvc.org/fcla/dt/12622
- Subject Headings
- Robots--Calibration, Robots--Control systems, Fuzzy logic
- Format
- Document (PDF)
- Title
- Workspace evaluation and kinematic calibration of Stewart platform.
- Creator
- Wang, Jian., Florida Atlantic University, Masory, Oren, Roth, Zvi S., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Parallel manipulators have their special characteristics in contrast to the traditional serial type of robots. Stewart platform is a typical six degree of freedom fully parallel robot manipulator. The goal of this research is to enhance the accuracy and the restricted workspace of the Stewart platform. The first part of the dissertation discusses the effect of three kinematic constraints: link length limitation, joint angle limitation and link interference, and kinematic parameters on the...
Show moreParallel manipulators have their special characteristics in contrast to the traditional serial type of robots. Stewart platform is a typical six degree of freedom fully parallel robot manipulator. The goal of this research is to enhance the accuracy and the restricted workspace of the Stewart platform. The first part of the dissertation discusses the effect of three kinematic constraints: link length limitation, joint angle limitation and link interference, and kinematic parameters on the workspace of the platform. An algorithm considering the above constraints for the determination of the volume and the envelop of Stewart platform workspace is developed. The workspace volume is used as a criterion to evaluate the effects of the platform dimensions and kinematic constraints on the workspace and the dexterity of the Stewart platform. The analysis and algorithm can be used as a design tool to select dimensions, actuators and joints in order to maximize the workspace. The remaining parts of the dissertation focus on the accuracy enhancement. Manufacturing tolerances, installation errors and link offsets cause deviations with respect to the nominal parameters of the platform. As a result, if nominal parameters are being used, the resulting platform pose will be inaccurate. An accurate kinematic model of Stewart platform which accommodates all manufacturing and installation errors is developed. In order to evaluate the effects of the above factors on the accuracy, algorithms for the forward and inverse kinematics solutions of the accurate model are developed. The effects of different manufacturing tolerances and installation errors on the platform accuracy are investigated based on this model. Simulation results provide insight into the expected accuracy and indicate the major factors contributing to the inaccuracies. In order to enhance the accuracy, there is a need to calibrate the platform, or to determine the actual values of the kinematic parameters (Parameter Identification) and to incorporate these into the inverse kinematic solution (Accuracy Compensation). An error-model based algorithm for the parameter identification is developed. Procedures for the formulation of the identification Jacobian and for accuracy compensation are presented. The algorithms are tested using simulated measurements in which the realistic measurement noise is included. As a result, pose error of the platform are significantly reduced.
Show less - Date Issued
- 1992
- PURL
- http://purl.flvc.org/fcla/dt/12316
- Subject Headings
- Robots--Control systems, Manipulators (Mechanism), Robotics--Calibration
- Format
- Document (PDF)
- Title
- Self-calibration of parallel-link mechanisms.
- Creator
- Liu, Lixin., Florida Atlantic University, Zhuang, Hanqi, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Self-calibration is a desirable feature for an intelligent machine such as a robot that must function outside of controlled laboratory conditions. This is because it is inevitable that variations in the kinematic model arise from imperfections in the manufacturing process and changes of environment conditions. Self-calibration has the potential of (a) removing the dependence on external pose sensing, (b) producing high accuracy measurement data over the entire workspace of the system with an...
Show moreSelf-calibration is a desirable feature for an intelligent machine such as a robot that must function outside of controlled laboratory conditions. This is because it is inevitable that variations in the kinematic model arise from imperfections in the manufacturing process and changes of environment conditions. Self-calibration has the potential of (a) removing the dependence on external pose sensing, (b) producing high accuracy measurement data over the entire workspace of the system with an extremely fast measurement rate, (c) being automated and completely non invasive, (d) facilitating on-line accuracy compensation, and (e) being cost effective. This dissertation concentrates on the study of self-calibrating parallel-link mechanisms. A framework of self-calibration of a parallel-link mechanism is created, which is based on kinematic analysis and the construction of measurement residuals utilizing the information provided by redundant sensors embedded in the system. Forward and inverse kinematic measurement residuals of the mechanisms are proposed. To avoid the estimation of redundant kinematic parameters of the mechanism, the concept of relative residuals is introduced. Guidelines for placement of sensors for self-calibration are presented. An approach to determining the number of independent kinematic parameters of the mechanism is introduced. Extensive simulation and experimental studies conducted on a parallel-link mechanism, the Stewart platform built in the Robotics Center at Florida Atlantic University, confirm the effectiveness of the proposed approach.
Show less - Date Issued
- 1997
- PURL
- http://purl.flvc.org/fcla/dt/12539
- Subject Headings
- Manipulators (Mechanism)--Calibration, Robots--Control systems, Robotics
- Format
- Document (PDF)
- Title
- A transputer-based fault-tolerant robot controller.
- Creator
- Kulkarni, Shubhada R., Florida Atlantic University, Fernandez, Eduardo B., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
In recent years robots have become increasingly important in many areas. A robotic controller requires high speed and high reliability and its design must continue these two aspects. This thesis presents a design for a Transputer based fault tolerant robot controller. For concreteness, we have designed this controller for a specific robot, the SEDAB, a prototype developed by IBM Corp. This design attempts to satisfy the two requirements of speed and reliability. Speed is achieved by the use...
Show moreIn recent years robots have become increasingly important in many areas. A robotic controller requires high speed and high reliability and its design must continue these two aspects. This thesis presents a design for a Transputer based fault tolerant robot controller. For concreteness, we have designed this controller for a specific robot, the SEDAB, a prototype developed by IBM Corp. This design attempts to satisfy the two requirements of speed and reliability. Speed is achieved by the use of a concurrent structure composed of Transputers. Reliability is provided by a self-testing mechanism and a multiprocessor system architecture. The Occam implementation of the robot processes is described. We have evaluated the reliability of this controller. The reliability study shows that there is a significant increase in the reliability of this controller due to the new architecture and proposed fault detection mechanism. While we have not been able to actually control this robot, we have shown that some scheduling heuristics can be effectively used to provide a higher level of performance.
Show less - Date Issued
- 1990
- PURL
- http://purl.flvc.org/fcla/dt/14616
- Subject Headings
- Robots--Control systems, Automatic control--Computer programs
- Format
- Document (PDF)
- Title
- Self-calibration of laser tracking measurement system with planar constraints.
- Creator
- Motaghedi, Shui Hu., Florida Atlantic University, Zhuang, Hanqi, Roth, Zvi S., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Laser tracking coordinate measuring machines have the potential of continuously measuring three dimensional target coordinates in a large workspace with a fast sampling rate and high accuracy. Proper calibration of a laser tracking measurement system is essential prior to use of such a device for metrology. In the absence of a more accurate instrument for system calibration, one has to rely on self-calibration strategies. In this dissertation, a kinematic model that describes not only the...
Show moreLaser tracking coordinate measuring machines have the potential of continuously measuring three dimensional target coordinates in a large workspace with a fast sampling rate and high accuracy. Proper calibration of a laser tracking measurement system is essential prior to use of such a device for metrology. In the absence of a more accurate instrument for system calibration, one has to rely on self-calibration strategies. In this dissertation, a kinematic model that describes not only the motion but also geometric variations of a multiple-beam laser tracking system was developed. The proposed model has the following features: (1) Target positions can be computed from both distance and angular measurements. (2) Through error analysis it was proven that even rough angular measurement may improve the overall system calibration results. A self-calibration method was proposed to calibrate intelligent machines with planar constraints. The method is also applied to the self-calibration of the laser tracking system and a standard PUMA 560 robot. Various calibration strategies utilizing planar constraints were explored to deal with different system setups. For each calibration strategy, issues about the error parameter estimation of the system were investigated to find out under which conditions these parameters can be uniquely estimated. These conditions revealed the applicability of the planar constraints to the system self-calibration. The observability conditions can serve as a guideline for the experimental setup when planar constraint is utilized in the machine calibration including the calibration of the laser tracking systems. Intensive simulation studies were conducted to check validity of the theoretical results. Realistic noise values were injected to the system models to statistically assess the behavior of the self-calibration system under real-world conditions. Various practical calibration issues were also explored in the simulations and therefore to pave ways for experimental investigation. The calibration strategies were also applied experimentally to calibrate a laser tracking system constructed at the Robotics Center in Florida Atlantic University.
Show less - Date Issued
- 1999
- PURL
- http://purl.flvc.org/fcla/dt/12599
- Subject Headings
- Robots--Kinematics, Robotics--Calibration--Measurement, Robots--Control systems
- Format
- Document (PDF)
- Title
- A force sensor system for the real time measurement of thrust on an AUV.
- Creator
- Larroque-Lahitette, Gilles., Florida Atlantic University, Holappa, Kenneth W., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
When a control system for an Autonomous Underwater Vehicle (AUV) requires thrust, it is common to apply a simplified model to estimate the force generated. Even though this model takes into account several parameters, it will never recover the real value. Our challenge is to directly measure the force, in real time, from the tunnel thrusters used in the positioning control of the Mini AUV known as Morpheus. Therefore, a force sensor system has been designed, optimized, machined and tested,...
Show moreWhen a control system for an Autonomous Underwater Vehicle (AUV) requires thrust, it is common to apply a simplified model to estimate the force generated. Even though this model takes into account several parameters, it will never recover the real value. Our challenge is to directly measure the force, in real time, from the tunnel thrusters used in the positioning control of the Mini AUV known as Morpheus. Therefore, a force sensor system has been designed, optimized, machined and tested, that supports the thruster assembly. The sensor implements strain gages to measure the deformation in a beam. To optimize the capabilities of the sensor, a finite elements analysis has been run. The sensor has been fabricated and tested to determine the static and dynamic characteristics. This thesis discusses the design implementation, optimization, fabrication and testing of the force sensor. The discussion begins with an overview of the problem, then explains the fabrication, optimization, testing and concludes with recommendation for future work.
Show less - Date Issued
- 2001
- PURL
- http://purl.flvc.org/fcla/dt/12745
- Subject Headings
- Oceanographic submersibles, Tactile sensors, Robots--Control systems
- Format
- Document (PDF)
- Title
- Statistical bounds on handoff probabilities under different fading channel models of mobile communication.
- Creator
- Laupattarakasem, Pet., Florida Atlantic University, Neelakanta, Perambur S., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
The research envisaged and reported in this thesis refers to finding comprehensive algorithms to determine the handoff probabilities of new and handoff calls encountered in mobile communications. The traditional expressions for these probabilities that are reported in the literature, are deduced only on the basis of call arrival statistics applied to RF links between base station (BS) and the mobile unit (MU). However, such radio links inevitably suffer from fading. These channels are...
Show moreThe research envisaged and reported in this thesis refers to finding comprehensive algorithms to determine the handoff probabilities of new and handoff calls encountered in mobile communications. The traditional expressions for these probabilities that are reported in the literature, are deduced only on the basis of call arrival statistics applied to RF links between base station (BS) and the mobile unit (MU). However, such radio links inevitably suffer from fading. These channels are normally modeled by appropriate probability density functions (pdfs) of the faded signal envelope. Rayleigh, Rician and Nakagami-m distributions are popularly considered in depicting such fading channel characteristics. The traditional (queueing-theoretic) based estimation of handoff probabilities does not account for the hysteresis-specific handoff statistics in the relevant fading channels. This is in contrary to the reality, inasmuch as fading is an inherent part of RF channels in mobile communications. The present study offers a tractable method of combining queuing-theoretic (call arrival) statistics and the hysteresis-crossing statistics of a RSS metric so as to obtain proper expressions for new and handoff call handoff probabilities. The (upper and lower) bound specified spread of the handoff probabilities indicates that care should be exercised in resource allocation efforts with a margin. To the best of the knowledge of the author, this research exercise is new and has not been reported elsewhere in open literature.
Show less - Date Issued
- 2003
- PURL
- http://purl.flvc.org/fcla/dt/13006
- Subject Headings
- Oceanographic submersibles, Tactile sensors, Robots--Control systems
- Format
- Document (PDF)
- Title
- A simplistic approach to reactive multi-robot navigation in unknown environments.
- Creator
- MacKunis, William Thomas., Florida Atlantic University, Raviv, Daniel, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Multi-agent control is a very promising area of robotics. In applications for which it is difficult or impossible for humans to intervene, the utilization of multi-agent, autonomous robot groups is indispensable. This thesis presents a novel approach to reactive multi-agent control that is practical and elegant in its simplicity. The basic idea upon which this approach is based is that a group of robots can cooperate to determine the shortest path through a previously unmapped environment by...
Show moreMulti-agent control is a very promising area of robotics. In applications for which it is difficult or impossible for humans to intervene, the utilization of multi-agent, autonomous robot groups is indispensable. This thesis presents a novel approach to reactive multi-agent control that is practical and elegant in its simplicity. The basic idea upon which this approach is based is that a group of robots can cooperate to determine the shortest path through a previously unmapped environment by virtue of redundant sharing of simple data between multiple agents. The idea was implemented with two robots. In simulation, it was tested with over sixty agents. The results clearly show that the shortest path through various environments emerges as a result of redundant sharing of information between agents. In addition, this approach exhibits safeguarding techniques that reduce the risk to robot agents working in unknown and possibly hazardous environments. Further, the simplicity of this approach makes implementation very practical and easily expandable to reliably control a group comprised of many agents.
Show less - Date Issued
- 2003
- PURL
- http://purl.flvc.org/fcla/dt/13013
- Subject Headings
- Robots--Control systems, Intelligent control systems, Genetic algorithms, Parallel processing (Electronic computers)
- Format
- Document (PDF)
- Title
- Object recognition by genetic algorithm.
- Creator
- Li, Jianhua., Florida Atlantic University, Han, Chingping (Jim), Zhuang, Hanqi, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
Vision systems have been widely used for parts inspection in electronics assembly lines. In order to improve the overall performance of a visual inspection system, it is important to employ an efficient object recognition algorithm. In this thesis work, a genetic algorithm based correlation algorithm is designed for the task of visual electronic parts inspection. The proposed procedure is composed of two stages. In the first stage, a genetic algorithm is devised to find a sufficient number of...
Show moreVision systems have been widely used for parts inspection in electronics assembly lines. In order to improve the overall performance of a visual inspection system, it is important to employ an efficient object recognition algorithm. In this thesis work, a genetic algorithm based correlation algorithm is designed for the task of visual electronic parts inspection. The proposed procedure is composed of two stages. In the first stage, a genetic algorithm is devised to find a sufficient number of candidate image windows. For each candidate window, the correlation is performed between the sampled template and the image pattern inside the window. In the second stage, local searches are conducted in the neighborhood of these candidate windows. Among all the searched locations, the one that has a highest correlation value with the given template is selected as the best matched location. To apply the genetic algorithm technique, a number of important issues, such as selection of a fitness function, design of a coding scheme, and tuning of genetic parameters are addressed in the thesis. Experimental studies have confirmed that the proposed GA-based correlation method is much more effective in terms of accuracy and speed in locating the desired object, compared with the existing Monte-Carlo random search method.
Show less - Date Issued
- 1995
- PURL
- http://purl.flvc.org/fcla/dt/15225
- Subject Headings
- Genetic algorithms, Robots--Control systems, Computer vision, Quality control--Optical methods
- Format
- Document (PDF)
- 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)
- Title
- Development of a graphical user interface for a Stewart platform.
- Creator
- Subramanian, Chenthilvel Muthukumaran., Florida Atlantic University, Masory, Oren, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
A user friendly graphical interface was developed to control a Stewart platform which is a six degree-of-freedom in-parallel mechanism. The interface allows the user to define the platform motion relative to various coordinate systems: base, platform and joint. The velocity/position reference to the platform's controller can be provided by the following ways: preprogrammed data file, serial communication RS-232, 6 degrees of freedom joystick and soft teach pendant. The platform was designed...
Show moreA user friendly graphical interface was developed to control a Stewart platform which is a six degree-of-freedom in-parallel mechanism. The interface allows the user to define the platform motion relative to various coordinate systems: base, platform and joint. The velocity/position reference to the platform's controller can be provided by the following ways: preprogrammed data file, serial communication RS-232, 6 degrees of freedom joystick and soft teach pendant. The platform was designed to be used as "Space Emulator" and therefore a 6 degrees of freedom force/torque sensor was needed. Two different models of such sensors were designed and analyzed using finite element analysis techniques. Based on the results one particular model was selected, fabricated, instrumented with strain gages and calibrated in order to obtain its stiffness matrix. The effect of drifting of the sensor output due to self heating of the strain gages and the electronic components of the strain gage amplifiers was also studied.
Show less - Date Issued
- 1993
- PURL
- http://purl.flvc.org/fcla/dt/14941
- Subject Headings
- Robots--Control systems, Robotics--Calibration, Manipulators (Mechanism), Finite element method, Graphical user interfaces (Computer systems)
- Format
- Document (PDF)
- Title
- Design & performance of a wind and solar-powered autonomous surface vehicle.
- Creator
- Rynne, Patrick Forde., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
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The primary objective of this research is the development a wind and solar-powered autonomous surface vehicle (WASP) for oceanographic measurements. This thesis presents the general design scheme, detailed aerodynamic and hydrodynamic aspects, sailing performance theory, and dynamic performance validation measurements obtained from a series of experiments. The WASP consists of a 4.2 meter long sailboat hull, a low-Reynolds number composite wing, a 2000 Watt-hour battery reservoir, a system of...
Show moreThe primary objective of this research is the development a wind and solar-powered autonomous surface vehicle (WASP) for oceanographic measurements. This thesis presents the general design scheme, detailed aerodynamic and hydrodynamic aspects, sailing performance theory, and dynamic performance validation measurements obtained from a series of experiments. The WASP consists of a 4.2 meter long sailboat hull, a low-Reynolds number composite wing, a 2000 Watt-hour battery reservoir, a system of control actuators, a control system running on an embedded microprocessor, a suite of oceanographic sensors, and power regeneration from solar energy. The vehicle has a maximum speed of five knots and weighs approximately 350 kilograms. Results from four oceanographic missions that were conducted in the Port Everglades Intracoastal Waterway in Dania Beach [sic] Florida are presented. Water temperature, salinity and oxidation-reduction measurements recorded during these missions are also discussed. The combination of a mono-hull and solid wing in an autonomous system is a viable design for a long-range ocean observation platform. The results of four near-shore ocean observation missions illustrate the initial capabilities of the design. Future work aimed to further reduce both the mass of the wing design and the power requirements of the system will increase performance in all operating conditions and should be considered. Furthermore, the progression of the legal framework related to ocean vehicles must be pursued with respect to unmanned autonomous systems.
Show less - Date Issued
- 2008
- PURL
- http://purl.flvc.org/FAU/166455
- Subject Headings
- Hydrographic surveying, Instruments, Evaluation, Aids to navigation, Equipment and supplies, Testing, Sailboats, Design and construction, Robots, Control systems, Oceanographic instruments, Evaluation
- Format
- Document (PDF)