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Advanced thermal management systems for internal combustion engines can improve coolant temperature regulation and servomotor power consumption by better regulating the combustion process with multiple electro-mechanical components. The traditional thermostat valve, coolant pump and clutch-driven radiator fan are upgraded with servomotor actuators. When the system components function harmoniously, desired thermal conditions can be accomplished in a power efficient manner. In this paper, a comprehensive control architecture is proposed for transient temperature tracking. An experimental system has been fabricated and assembled which features a variable position smart thermostat valve, variable speed electric water pump, variable speed electric radiator fan, engine block, and various sensors. In the configured system, the steam-based heat exchanger emulates the heat generated by the engine's combustion process. Representative numerical and experimental results are discussed to demonstrate the functionality of the thermal management system in tracking prescribed temperature profiles., The original document contains color images.

Continuum or hyper-redundant robots are robots which exhibit behavior similar to biological trunks, tentacles and snakes. Unlike traditional robots, continuum robot manipulators do not have rigid joints, hence the manipulators are compliant, extremely dexterous, and capable of dynamic, adaptive manipulation in unstructured environments; however, the development of high-performance control algorithms for these manipulators is a challenging problem. In this paper, we present an approach to whole arm grasping control for continuum robots. The grasping controller is developed in two stages; high level path planning for the grasping objective, and a low level joint controller using a neural network feedforward component to compensate for dynamic uncertainties. These techniques are used to enable whole arm grasping without using contact force measurements and without using a dynamic model of the continuum robot. Experimental results using the OCTARM, a soft continuum robotic manipulator are included to illustrate the efficacy of the proposed low level joint controller., Sponsored in part by ARO Automotive Center, the Department of Commerce and the Department of Energy. The original document contains color images.

In this paper, we present the development of a vision-based estimator for simultaneous determination of velocity and structure of an object (i.e., the Euclidean position of its feature points) for the general case where both the object and the camera are moving relative to an inertial frame of reference. The velocity estimation itself requires no explicit kinematic model, while the adaptive structure estimator, synthesized utilizing Lyapunov design methods, is built upon kinematic relationships that rely on homography-based techniques., Sponsored in part by ARO Automotive Center, the Department of Commerce and the Department of Energy. The original document contains color images.

Several approaches for incorporating navigation function approach into different controllers are developed in this paper for task execution by a non-holonomic system (e.g., a wheeled mobile robot) in the presence of known obstacles. The first approach is a path planning-based control with planning a desired path based on a 3-dimensional position and orientation information. A navigation-like function yields a path from an initial configuration inside the free configuration space of the mobile robot to a goal configuration. A differentiable oscillator-based controller is then used to enable the mobile robot to follow the path and stop at the goal position. A second approach is developed for a navigation function that is constructed using 2-dimensional position information. A differentiable controller is proposed based on this navigation function that yields asymptotic convergence. Simulation results are provided to illustrate the performance of the second approach., Prepared in cooperation with University of Florida, Gainesville, FL. Sponsored in part by Air Force Office of Scientific Research (AFOSR), contract no. F49620-03-1-0381; Department of Commerce (DoC); Army Research Office (ARO); and Defense Advanced Research Projects Agency (DARPA). The original document contains color images.

An approach to whole arm grasping of objects using redundant robot manipulators is presented. A kinematic control development is presented which facilitates the encoding of both the end-effector position, as well as body self-motion positioning information as a desired trajectory signal for the manipulator joints. A joint space controller which provides asymptotic tracking of the encoded desired trajectory in the presence of system uncertainties is then presented. Experimental results for a planar, three link configuration of the Barrett whole arm manipulator are provided to illustrate the validity of the approach., Sponsored in part by ARO Automotive Center, Department of Commerce, and Department of Energy. The original document contains color images.

In this paper, we present a path generation and control strategy for a robotic manipulator to mimic the dynamics of a continuously reconfigurable anisotropic impedance. Motivated by a nonholonomic kinematic constraint, a dynamic path generator is designed to trace a desired contour in the robot's workspace when an interaction force is applied at the robot's end-effector. The proposed continuous control strategy achieves semi-global asymptotically stable path following for the robot manipulator in the presence of uncertainty in the robot dynamics. Additionally, the path generator also ensures safety by maintaining the desired net flow of energy during the human robot interaction from the user toward the manipulator. In addition to providing asymptotic path following, the control algorithm also ensures sufficiently rapid error convergence at the end-effector such that the actual energy transfer profile follows the desired energy transfer profile - thus rigorously ensuring user safety. A variation of the generation and control algorithms is presented to deal with unknown interaction force at the end-effector., Sponsored in part by ARO Automotive Center, Department of Commerce, and Department of Energy. The original document contains color images.

In this paper, a visual servo tracking controller for a wheeled mobile robot (WMR) is developed that utilizes feedback from a monocular camera system that is mounted with a fixed position and orientation (i.e., the eye-to-hand problem). A pre-recorded image sequence (e.g., a video) of four target points is used to define a desired trajectory for the WMR. By comparing the target points from the pre-recorded sequence with the corresponding target points in the live image, projective geometric relationships are exploited to construct a Euclidean homography. The information obtained by decomposing the Euclidean homography is used to develop a kinematic controller. A Lyapunov-based analysis is used to develop an adaptive update law to actively compensate for the lack of depth information required for the translation error system. In contrast to previous WMR visual servo controllers using a fixed camera configuration, the controller in this paper does not require the camera to be mounted so that the optical axis is perpendicular to the WMR plane of motion. An extension is provided to illustrate the development of a visual servo regulation controller. Simulation results are provided to demonstrate the performance of the tracking control design., Prepared in cooperation with Oak Ridge National Laboratory, Oak Ridge, TN. Sponsored in part by U.S. Department of Energy (DoE), project no. 82797; National Science Foundation (NSF), grant no. DMI-9457967; and Army Research Office (ARO). The original document contains color images.

In this paper, an adaptive nonlinear estimator is developed to identify the Euclidean coordinates of feature points on a moving object using a single fixed camera. No explicit model is used to describe the movement of the object. Homography-based techniques are used in the development of the object kinematics, while Lyapunov design methods are utilized in the synthesis of the adaptive estimator. Simulation results are included to demonstrate the performance of the estimator., Sponsored in part by the Defense Advanced Research Projects Agency, the US Dept. of Commerce and the US Dept. of Energy. Cataloger's note: a version was presented at the American Control Conference held in Portland, OR on 8-10 June 2005 and published in proceedings of the same, v7, p4601-4606, 2005. The original document contains color images.

Traditionally, robot control research has focused on the position tracking problem where the objective is to force the robot's end-effector to follow an a priori known desired time dependent trajectory. Motivated by task objectives that are more effectively described by on-line, state-dependent trajectories, two adaptive tracking controllers are developed in this paper that accommodate on-line path planning objective. An example adaptive controller is first modified to achieve velocity field tracking in the presence of parametric uncertainty in the robot dynamics. The development aims to relax the typical assumption that the integral of the velocity field is bounded by incorporating a norm- squared gradient term in the control design so that the boundedness of all signals can be proven. An extension is then provided that targets the trajectory planning problem where the task objective can be described as the desire to move to a goal configuration while avoiding known obstacles. Specifically, an adaptive navigation function based controller is designed to provide a path from an initial condition inside the free configuration space of the robot manipulator to the goal configuration. Experimental results for each controller are provided to illustrate proof of validation of the approaches., Prepared in cooperation with University of Florida, Gainesville, FL. Sponsored in part by Space & Naval Warfare Systems Center, San Diego, CA, contract no. N66001-03-R-8043; National Science Foundation (NSF), grant no. DMI-9457967; Defense Advanced Research Projects Agency (DARPA; Department of Commerce (DoC); and Army Research Office (ARO). The original document contains color images.

In this paper, we design an adaptive kinematic controller that asymptotically regulates a robot end-effector to a desired position and orientation under visual feedback (of points located on a fixed reference frame) from a camera mounted on the end-effector. This task is accomplished despite lack of depth measurements as well as uncertainty in the camera intrinsic parameter matrix., Presented at the IEEE Conference on Decision and Control, Maui, HI, on 9-12 Dec 2003, and published in the proceedings of the same as paper FrM08-02, p5396-5041. ISBN 0-7803-7924-1.

In recent papers, a new class of model-free (i.e., the 3-dimensional task-space model of the object is unknown) visual servoing methods was proposed that are based on the estimation of the relative camera orientation between two views of an object. By utilizing homography-based techniques, the control problem is decoupled by separating the rotation and translation components. A single controller is used to control the rotation component, and the class members consist of various translation controllers. Each of the current class members has been proven to yield asymptotic regulation in the presence of uncertainty in the intrinsic and extrinsic calibration parameters. New control development and stability analysis techniques are crafted in this paper to develop a new translation controller that yields exponential rotation and translation regulation in the presence of uncertainty in the intrinsic and extrinsic calibration parameters. Extensions to this research can be used to yield exponential regulation by the other translation controllers., Presented at the IEEE Conference on Decision and Control, Maui, HI, on 9-12 Dec 2003, an published in the proceedings of the same as paper FrM08-1, p5390-5395. ISBN 0-7803-7924-1.