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 Title
 THE DYNAMICS OF THE GENERALIZED MANIPULATOR.
 Creator
 LAU, TOCHOI., Florida Atlantic University, Roth, Zvi S., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
 Abstract/Description

The concept of "generalized manipulator" is introduced, and the closed form and recursive form dynamical models of the generalized manipulator are presented in NewtonEuler formulation. The physical meaning of each term in the dynamical model is explained. The dynamical models formulated by the NewtonEuler method and the LagrangianEuler method are proved equivalent. The dynamical model of the generalized manipulator is reduced to ordinary manipulators. The reduced dynamical model is shown...
Show moreThe concept of "generalized manipulator" is introduced, and the closed form and recursive form dynamical models of the generalized manipulator are presented in NewtonEuler formulation. The physical meaning of each term in the dynamical model is explained. The dynamical models formulated by the NewtonEuler method and the LagrangianEuler method are proved equivalent. The dynamical model of the generalized manipulator is reduced to ordinary manipulators. The reduced dynamical model is shown identical to existing models. Furthermore, the reduced dynamical model of the generalized manipulator can be used to compute forces and torques components along any direction. Application of the model to problems of mobile robots and flexible manipulators is shown.
Show less  Date Issued
 1985
 PURL
 http://purl.flvc.org/fcla/dt/14243
 Subject Headings
 Manipulators (Mechanism), Robots
 Format
 Document (PDF)
 Title
 A simplified Jacobian representation for robot manipulators.
 Creator
 Alewine, Neal Jon., Florida Atlantic University, Roth, Zvi S.
 Abstract/Description

Central to many manipulator positional control schemes is a requirement to invert the forward kinematic equations which model the given manipulator. It is shown in this thesis that for manipulator types where a common wrist center exists, a simplified Jacobian form is feasible and its inversion can be used in place of inverse kinematic solutions for positional control. The Jacobian simplification is obtained by decoupling of the wrist member from the positional member, resulting in a Jacobian...
Show moreCentral to many manipulator positional control schemes is a requirement to invert the forward kinematic equations which model the given manipulator. It is shown in this thesis that for manipulator types where a common wrist center exists, a simplified Jacobian form is feasible and its inversion can be used in place of inverse kinematic solutions for positional control. The Jacobian simplification is obtained by decoupling of the wrist member from the positional member, resulting in a Jacobian inversion involving the solution of two sets of three equations with three unknowns. Within the development of the alternate Jacobian form, a technique for substituting incremental rotations with incremental translations is introduced yielding better insight into the Jacobian structure. A requirement for small moves is validated with a discussion of a proposed positional control strategy and a comprehensive example is presented as a summary of the results.
Show less  Date Issued
 1988
 PURL
 http://purl.flvc.org/fcla/dt/14477
 Subject Headings
 Robots, Manipulators (Mechanism), Matrices
 Format
 Document (PDF)
 Title
 Kinematic modeling, identification and compensation of robot manipulators.
 Creator
 Zhuang, Hanqi, Florida Atlantic University, Hamano, Fumio, Roth, Zvi S., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
 Abstract/Description

Theoretical and practical issues of kinematic modeling, measurement, identification and compensation are addressed in this dissertation. A comprehensive robot calibration methodology using a new Complete and Parametrically Continuous (CPC) kinematic model is presented. The dissertation focuses on modelbased robot calibration techniques. Parametric continuity of a kinematic model is defined and discussed to characterize model singularity. Irreducibility is defined to facilitate error model...
Show moreTheoretical and practical issues of kinematic modeling, measurement, identification and compensation are addressed in this dissertation. A comprehensive robot calibration methodology using a new Complete and Parametrically Continuous (CPC) kinematic model is presented. The dissertation focuses on modelbased robot calibration techniques. Parametric continuity of a kinematic model is defined and discussed to characterize model singularity. Irreducibility is defined to facilitate error model reduction. Issues of kinematic parameter identification are addressed by utilizing generic forms of linearized kinematic error models. The CPC model is a complete and parametrically continuous kinematic model capable of describing geometry and motion of a robot manipulator. Owing to the completeness of the CPC model, the transformation from the base frame to the world frame and from the tool frame to the last link frame can be modeled with the same modeling convention as the one used for internal link transformations. Due to the parametric continuity of the CPC model, numerical difficulties in kinematic parameter identification using error models are reduced. The CPC model construction, computation of the link parameters from a given link transformation, inverse kinematics, transformations between the CPC model and the DenavitHartenberg model, and linearized CPC error model construction are investigated. New methods for selfcalibration of a laser tracking coordinatemeasuringmachine are reported. Two calibration methods, one based on a fourtracker system and the other based on three trackers with a precision plane, are proposed. Iterative estimation algorithms along with simulation results are presented. Linear quadratic regulator (LQR) theory is applied to design robot accuracy compensators. In the LQR algorithm, additive corrections of joint commands are found without explicitly solving the inverse kinematic problem for an actual robot; a weighting matrix and coefficients in the cost function can be chosen systematically to achieve specific objective such as emphasizing the positioning accuracy of the endeffector over its orientation accuracy and vice versa and taking into account joint travelling limits as well as singularity zones of the robot. The results of the kinematic identification and compensation experiments using the PUMA robot have shown that the CPC modeling technique presented in this dissertation is a convenient and effective means for accuracy improvements of industrial robots.
Show less  Date Issued
 1989
 PURL
 http://purl.flvc.org/fcla/dt/12243
 Subject Headings
 Robotics, Manipulators (Mechanism)
 Format
 Document (PDF)
 Title
 Cameraaided selfcalibration of robot manipulators.
 Creator
 Meng, Yan., Florida Atlantic University, Zhuang, Hanqi, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
 Abstract/Description

Robot calibration is a softwarebased accuracy enhancement process. It is normally implemented in a wellcontrolled environment. However, for a system that function in a natural environment, it is desirable that the system is capable of performing a calibration task without any external expensive calibration apparatus and elaborate setups, i.e., system selfcalibration. Vision systems have become standard automation components as cameras are normally integral components of most robotic...
Show moreRobot calibration is a softwarebased accuracy enhancement process. It is normally implemented in a wellcontrolled environment. However, for a system that function in a natural environment, it is desirable that the system is capable of performing a calibration task without any external expensive calibration apparatus and elaborate setups, i.e., system selfcalibration. Vision systems have become standard automation components as cameras are normally integral components of most robotic manipulators. This research focuses on cameraaided robot selfcalibration. Unlike classical visionbased robot calibration methods, which need both image coordinates and precise 3D world coordinates of calibration points, the selfcalibration algorithms proposed in the dissertation only require a sequence of images of objects in a natural environment and a known scale. A new robot selfcalibration algorithm using a known scale at every camera pose is proposed in the dissertation. It has been known that, the extrinsic parameters of the camera along with its intrinsic parameters can be obtained up to a scale factor by using the corresponding image points of objects due to the factor that the system is inherently underdetermined. Now, if the camera is treated as the tool of the robot, one is then able to compute the corresponding robot pose directly from the camera, extrinsic parameters once the scale factor is available. This scale factor, which changes from one camera pose to another, can be uniquely determined from the known scale at each robot pose. The limitation of the above approach for robot selfcalibration is that the known scale has to be utilized at every robot measurement pose. A new algorithm is proposed by using the known scale only once in the entire selfcalibration procedure. The prerequisite of this calibration algorithm is a carefully planned optimal measurement trajectory for the estimation of the scale factor. By taking into consideration of the observability of the link error parameters, the problem can be formulated either as a constrained or a weighted minimization problem that can be solved by an optimization procedure. A new method for camera lens distortion calibration by using only point correspondences of two images without knowing the camera movement is described in the dissertation. The images for robot calibration can be shared for lens distortion coefficient calibration. This characteristic saves the user much effort in collecting image data and makes it possible to conduct a robot calibration task on line. Extensive simulations and experiment studies on a PUMA 560 robot at FAU Robotics Center reveal the convenience and effectiveness of the proposed selfcalibration approaches. Compared to other robot calibration algorithms, the proposed algorithms in this dissertation are more autonomous and can be applied to a natural environment.
Show less  Date Issued
 2000
 PURL
 http://purl.flvc.org/fcla/dt/12651
 Subject Headings
 Manipulators (Mechanism), RobotsCalibration
 Format
 Document (PDF)
 Title
 NEIGHBORING NEAR MINIMUMTIME CONTROLS WITH DISCONTINUITIES AND THE APPLICATION TO THE CONTROL OF MANIPULATORS (PATHPLANNING, TRACKING, FEEDBACK).
 Creator
 Zhuang, Hanqi, Florida Atlantic University, Hamano, Fumio, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
 Abstract/Description

This thesis presents several algorithms to treat the problem of closedloop near minimumtime controls with discontinuities. First, a neighboring control algorithm is developed to solve the problem in which controls are bounded by constant constraints. Secondly, the scheme is extended to account for statedependent control constraints. And finally, a path tracking algorithm for robotic manipulators is presented, which is also a neighboring control algorithm. These algorithms are suitable for...
Show moreThis thesis presents several algorithms to treat the problem of closedloop near minimumtime controls with discontinuities. First, a neighboring control algorithm is developed to solve the problem in which controls are bounded by constant constraints. Secondly, the scheme is extended to account for statedependent control constraints. And finally, a path tracking algorithm for robotic manipulators is presented, which is also a neighboring control algorithm. These algorithms are suitable for real time controls because the online computations involved are relatively simple. Simulation results show that these algorithms work well despite the fact that the prescribed final points can not be reached exactly.
Show less  Date Issued
 1986
 PURL
 http://purl.flvc.org/fcla/dt/14326
 Subject Headings
 Manipulators (Mechanism), Control theory, Algorithms
 Format
 Document (PDF)
 Title
 Twodimensional approximation and learning control of robot manipulators.
 Creator
 Gautam, Ashutosh., Florida Atlantic University, Zilouchian, Ali
 Abstract/Description

In this thesis, a novel twodimensional learning control scheme for robot manipulators is proposed. The convergence of the scheme for a general ndegree of freedom robot is shown. In the next part of the thesis, an algorithm for the approximation of a twodimensional causal, recursive, separableindenominator (CRSD) filter, using the impulse response and autocorrelation data, is presented. The stability of the designed filter is discussed and it is shown that the approximated filter is...
Show moreIn this thesis, a novel twodimensional learning control scheme for robot manipulators is proposed. The convergence of the scheme for a general ndegree of freedom robot is shown. In the next part of the thesis, an algorithm for the approximation of a twodimensional causal, recursive, separableindenominator (CRSD) filter, using the impulse response and autocorrelation data, is presented. The stability of the designed filter is discussed and it is shown that the approximated filter is always stable. The simulation results for the approximation technique as well as the twodimensional learning control scheme are also included in the thesis.
Show less  Date Issued
 1989
 PURL
 http://purl.flvc.org/fcla/dt/14559
 Subject Headings
 Control theory, Manipulators (Mechanism), Robots
 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), RobotsControl 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 openloop 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 openloop 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), RobotsControl systems
 Format
 Document (PDF)
 Title
 Kinematic modeling and analysis of a parallelseries hybrid manipulator.
 Creator
 Sheng, Yang., Florida Atlantic University, Huang, Ming Z., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
 Abstract/Description

Traditional industrial manipulators possess fixed configuration and are widely used in manufacturing application in which the manipulator base is fixed. However, some applications exist which would require the robotic manipulators to function in nonstationary environment especially in space. In this thesis, a six degree of freedom parallelseries hybrid manipulator is described. It consists of a 3 d.o.f. inseries manipulator mounted on a 3 d.o.f. inparallel manipulator. A compatibility...
Show moreTraditional industrial manipulators possess fixed configuration and are widely used in manufacturing application in which the manipulator base is fixed. However, some applications exist which would require the robotic manipulators to function in nonstationary environment especially in space. In this thesis, a six degree of freedom parallelseries hybrid manipulator is described. It consists of a 3 d.o.f. inseries manipulator mounted on a 3 d.o.f. inparallel manipulator. A compatibility equation is found to govern the relationship between inseries component angular velocity and linear velocity; a constraint equation is added to the Jacobian of inparallel component. Using these two equations, a decomposition strategy is proposed for solving the inverse velocity problem of the hybrid manipulator together with the simulation examples of inverse position tracking and straight line trajectory planning. Effectiveness of this method and factors affecting the simulation result are examined.
Show less  Date Issued
 1993
 PURL
 http://purl.flvc.org/fcla/dt/14893
 Subject Headings
 Kinematics, RoboticsComputer programs, Manipulators (Mechanism)
 Format
 Document (PDF)
 Title
 A unified theory of coordination for robotic mechanisms with general parallel or hybrid structures.
 Creator
 Ling, ShouHung., Florida Atlantic University, Huang, Ming Z., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
 Abstract/Description

A well designed robot manipulator should have adequate workspace and good staticdynamic performance. It is well known that serial manipulators, while compared to similar size parallel ones, have larger workspace. However, due to their cantileverlike structure, the serial manipulators suffer from the disadvantage of having relatively poor staticdynamic performance. Contrarily, for fully parallel manipulators the good staticdynamic performance comes from the sacrifice of the workspace....
Show moreA well designed robot manipulator should have adequate workspace and good staticdynamic performance. It is well known that serial manipulators, while compared to similar size parallel ones, have larger workspace. However, due to their cantileverlike structure, the serial manipulators suffer from the disadvantage of having relatively poor staticdynamic performance. Contrarily, for fully parallel manipulators the good staticdynamic performance comes from the sacrifice of the workspace. Therefore, manipulators with more general geometries, in particular those with both the serial and the parallel modules, namely the hybrid manipulators, have attracted much of the research attention in robotics recently. While it can be asserted that kinematic theories and techniques are well established for fully serialchain manipulators, the same assertion cannot be made when they are considered in the above general context. The research described in this dissertation is an undertaking toward the establishment of a general theory of coordination for robotic mechanisms with general parallel or hybrid structures. The scope of this research is concentrated in the kinematics aspect of the aforementioned class of robot manipulators with the main emphasis on the velocity (instantaneous) kinematics. A kinestatic approach, which is based on screw system theory, is adopted in this dissertation. This kinestatic approach leads to the establishment of a fundamental theorem, dubbed as the Parallel Manipulator Coordination Theorem, which integrates the idea of parallel and serial manipulators. Furthermore, the theorem enables us to develop an analysis strategy for systematic formulation and characterization of robotic mechanisms with general parallel (nonredundant) and hybrid geometries. The analysis strategy entails constraints, statics, velocity, and singularity considerations. One distinct advantage of using the screw system theory as the analysis tool is that it facilitates the analysis in a fashion that physical meanings are preserved through out the derivation. The very aspect of preserving the physical meaning distinguishes this method from other algebraicallybased and numericallybased methods. An intelligent faulttolerant system has been studied at the end. The technique and conclusions from the study of parallel manipulator modules have been used to analyze the proposed design.
Show less  Date Issued
 1994
 PURL
 http://purl.flvc.org/fcla/dt/12385
 Subject Headings
 Manipulators (Mechanism), Robotics, Kinematics, Screws, Theory of
 Format
 Document (PDF)
 Title
 Hybrid telemanipulation simulation for mission rehearsal and intervention.
 Creator
 Agba, Emmanuel I., Florida Atlantic University, Wong, TinLup, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
 Abstract/Description

A "hybrid" telerobotic simulation system that is suitable for telemanipulation rehearsal, operator training, human factors study and operator performance evaluation has been developed. The simulator also has the capabilities for eventual upgrade for supervisory control. It is capable of operation in the conventional ratecontrol, master/slave control and a data driven preprogrammed mode of operation. It has teach/playback capability which allows an operator to generate joint commands for real...
Show moreA "hybrid" telerobotic simulation system that is suitable for telemanipulation rehearsal, operator training, human factors study and operator performance evaluation has been developed. The simulator also has the capabilities for eventual upgrade for supervisory control. It is capable of operation in the conventional ratecontrol, master/slave control and a data driven preprogrammed mode of operation. It has teach/playback capability which allows an operator to generate joint commands for real time teleoperation. For highlevel task execution, the operator selects a specific task from a set of menu options and the simulator automatically generates the required joint commands. The simulator was developed using a three dimensional graphic model of an increasingly popular manipulator, TITAN 7F. A closedform solution for inverse kinematics of the manipulator was found. Degeneracies from inverse kinematics solutions were observed to exist for certain arm configurations, although the manipulator can physically attain such configurations. An approach based on known facts about the manipulator geometry and physical constraints coupled with heuristics was used to generate physically attainable joint solutions from the inverse kinematics. The conditions that cause solution degeneracy were demonstrated to be related to singularity conditions. A novel object interaction detection strategy was implemented for more realistic telemanipulation. The object detection technique was developed based on the use of superellipsoid, which has a convenient insideoutside function for interference testing. The manipulator, with its endeffector and payloads, if any, were modeled as superquadric ellipsoids. A systematic way of determining transformation matrices between the superquadric manipulator links was developed. The interaction detection technique treats both moving and stationary objects in a consistent manner and has proved to be easy to implement and optimize for realtime applications. The feature has been applied for the simulation of pickandplace operations and collision detection. It is also used to provide visual feedback as a lowcost force reflection and can be interfaced with a bilateral controller for force reflection simulation.
Show less  Date Issued
 1991
 PURL
 http://purl.flvc.org/fcla/dt/12278
 Subject Headings
 Manipulators (Mechanism), Remote control, Vehicles, Remotely piloted, Remote submersibles
 Format
 Document (PDF)
 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 machinea type of parallel manipulators similar to a Stewart platform. The goal of this research is to develop an effective control scheme, crosscoupling 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 machinea type of parallel manipulators similar to a Stewart platform. The goal of this research is to develop an effective control scheme, crosscoupling 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 (ProportionalIntegralDerivative) controller was designed for each leg of the hexapod CNC machine. Secondly, realtime 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 crosscoupling control scheme was proposed for the purpose to enhance the contour accuracy of this new type of hexapod CNC machine tools. A crosscoupling controller design for a 2DOF platform was performed to provide the guidelines. Then, a crosscoupling 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 crosscoupling controller was verified through simulations. The result shows that the proposed crosscoupling controller is very effective in reducing the contouring errors. While crosscoupling 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
 MachinetoolsNumerical control, Manipulators (Mechanism), PID controllers
 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 errormodel 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
 RobotsControl systems, Manipulators (Mechanism), RoboticsCalibration
 Format
 Document (PDF)
 Title
 Selfcalibration of parallellink 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

Selfcalibration 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. Selfcalibration 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 moreSelfcalibration 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. Selfcalibration 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 online accuracy compensation, and (e) being cost effective. This dissertation concentrates on the study of selfcalibrating parallellink mechanisms. A framework of selfcalibration of a parallellink 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 selfcalibration 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 parallellink 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, RobotsControl systems, Robotics
 Format
 Document (PDF)
 Title
 Cameraaided SCARA arm calibration.
 Creator
 Wu, Wenchiang., Florida Atlantic University, Zhuang, Hanqi, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
 Abstract/Description

The focus of this thesis is the kinematic calibration of a SCARA arm with a handmounted camera. Kinematic calibration can greatly improve the accuracy of SCARA arms, which are widely used in electronic assembly lines. Visionbased robot calibration has the potential of being a fast, nonintrusive, lowcost, and autonomous approach. In this thesis, we apply a visionbased technique to calibrate SCARA arms. The robot under investigation is modeled by the modified complete and parametrically...
Show moreThe focus of this thesis is the kinematic calibration of a SCARA arm with a handmounted camera. Kinematic calibration can greatly improve the accuracy of SCARA arms, which are widely used in electronic assembly lines. Visionbased robot calibration has the potential of being a fast, nonintrusive, lowcost, and autonomous approach. In this thesis, we apply a visionbased technique to calibrate SCARA arms. The robot under investigation is modeled by the modified complete and parametrically continuous model. By repeatedly calibrating the camera, the pose of the robot endeffector are collected at various robot measurement configurations. A least squares technique is then applied to estimate the geometric error parameters of the SCARA arm using the measured robot poses. In order to improve the robustness of the method, a new approach is proposed to calibrate the handmounted camera. The calibration algorithm is designed to deal with the case in which the camera sensor plane is nearlyparallel to the camera calibration board. Practical issues regarding robot calibration in general and SCARA arm calibration in particular are also addressed. Experiment studies reveal that the proposed cameraaided approach is a viable means for accuracy enhancement of SCARA arms.
Show less  Date Issued
 1994
 PURL
 http://purl.flvc.org/fcla/dt/15075
 Subject Headings
 RobotsCalibration, Manipulators (Mechanism)Calibration, RobotsError detection and recovery, Image processing
 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 sixlink 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 sixlink 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 systemsComputer simulation, PID controllersComputer 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 degreeoffreedom inparallel 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 RS232, 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 degreeoffreedom inparallel 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 RS232, 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
 RobotsControl systems, RoboticsCalibration, Manipulators (Mechanism), Finite element method, Graphical user interfaces (Computer systems)
 Format
 Document (PDF)
 Title
 Development of a morphing autonomous underwater vehicle for path and station keeping in complex current environments.
 Creator
 Meneses, Andrea M., Su, TsungChow, Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
 Abstract/Description

This thesis explores the feasibility of using morphing rudders in autonomous underwater vehicles (AUVs) to improve their performance in complex current environments. The modeling vehicle in this work corresponds to the Florida Atlantic University's Ocean EXplorer (OEX) AUV. The AUV nonlinear dynamic model is limited to the horizontal plane and includes the effect of ocean current. The main contribution of this thesis is the use of active rudders to successfully achieve path keeping and...
Show moreThis thesis explores the feasibility of using morphing rudders in autonomous underwater vehicles (AUVs) to improve their performance in complex current environments. The modeling vehicle in this work corresponds to the Florida Atlantic University's Ocean EXplorer (OEX) AUV. The AUV nonlinear dynamic model is limited to the horizontal plane and includes the effect of ocean current. The main contribution of this thesis is the use of active rudders to successfully achieve path keeping and station keeping of an AUV under the influence of unsteady current force. A constant ocean current superimposed with a sinusoidal component is considered. The vehicle's response is analyzed for a range of current frequencies.
Show less  Date Issued
 2014
 PURL
 http://purl.flvc.org/fau/fd/FA00004137, http://purl.flvc.org/fau/fd/FA00004137
 Subject Headings
 Autonomous robots  Design and construction, Fracture mechanics, Manipulation (Mechanism)  Control, Remote submersibles  Design and construction, Vehicles, Remotely piloted  Design and construction
 Format
 Document (PDF)