作者：
Derby, StephenDirector
Mechatronics and Assembly Lab New York State Center for Advanced Technology in Automation Robotics and Manufacturing Rensselaer Polytechnic Institute TroyNY12180 United States
This paper details a set of methodologies to design a robot based on an existing workcell that would be difficult or costly to modify. Standard robot bases, as well as tracked robots, are located to minimize the error...
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Consider a vehicle using a number of landmarks for navigation. Between the observation of the landmarks, the motion of the vehicle is estimated using internal sensors like odometers and rate gyros. The output from a d...
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Consider a vehicle using a number of landmarks for navigation. Between the observation of the landmarks, the motion of the vehicle is estimated using internal sensors like odometers and rate gyros. The output from a dead reckoning algorithm is used in a Kalman filter and/or used to make association of observed landmarks. In such system the accuracy of the dead reckoning algorithm is essential for the overall performance. In this paper 'slip angles' at the wheel-surface contact point are included in the kinematic model. The slip angle is assumed to be essentially proportional to the side force. The topics in this paper are: • Dead reckoning model with a slip angle. • Improved dead reckoning when a rate gyro is used. • Equations for comparing the error growth. Four different algorithms for dead reckoning are studied and compared. Two of them just model the slippage and two of them are based on more accurate measurements of rotation, using a rate gyro.
We study control problems for a specific mechanical system consisting of a rigid base body with an unactuated internal degree of freedom. The key assumptions are that the translational and rotational motion of the bas...
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The problem addressed is segmentation and shape estimation of three-dimensional laser range measurements of forest scenes. For each tree the position as well as the three dimensional shape of the trunk is estimated. T...
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The problem addressed is segmentation and shape estimation of three-dimensional laser range measurements of forest scenes. For each tree the position as well as the three dimensional shape of the trunk is estimated. The detection uses a two-dimensional histogram of the measurements, followed by segmentation by fitting cylinders around the measurements of each detected tree trunk. The shape estimation consists of fitting a 3D spline to each tree trunk's centre curve and computing the trunk width by extracting the range discontinuities at the edges. For the experiments a mobile robot carrying a scanning laser range finder was used. Navigation was done by matching the extracted tree trunk positions from subsequent range scans, determining the relative movements.
Force feedback devices for use in virtual reality have been the design, which enable the user to interact with the virtual environment in real-time. We have developed a virtual environment for lumbar puncture, a widel...
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Force feedback devices for use in virtual reality have been the design, which enable the user to interact with the virtual environment in real-time. We have developed a virtual environment for lumbar puncture, a widely used medical technique involving the insertion of a 3 inch long needle in the spinal region of a patient involving real-time 3D display of the spinal region and real-time force feedback. The trainee can insert a specialized joystick needle in a virtual spine and simultaneously "feel" a realistic force response, matching the real procedure. Our goal is to be able to control the motor such that the whole system "feels" like a needle penetrating the human tissue. In order to create a realistic simulation involving force feedback we show how force feedback theory can be applied to our virtual environment.
Consider a robot to measure or operate on man made objects randomly located in the workspace. The optronic sensing onboard the robot are a scanning range measuring time-of-flight laser and a CCD camera. The goal of th...
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Consider a robot to measure or operate on man made objects randomly located in the workspace. The optronic sensing onboard the robot are a scanning range measuring time-of-flight laser and a CCD camera. The goal of the paper is to give explicit covariance matrices for the extracted geometric primitives in the surrounding workspace. Emphasis is on correlation properties of the stochastic error models during motion. Topics studied include: (i) covariance of Radon/Hough peaks for plane surfaces; (ii) covariances for the intersection of two planes; (iii) equations for combining vision features, plane surfaces and range discontinuities; and (iv) explicit equations of how the covariance matrices are transformed during the robot motion. Typical applications are; models for verification and updating of CAD-models when navigating inside buildings and industrial plants, and accumulating sensor readings for a telecommanded robot.
In this paper the positioning of a long flexible manipulator on a moving platform is investigated. The problem is to position the gripper at a requested relative distance in front of an object with an unknown location...
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In this paper the positioning of a long flexible manipulator on a moving platform is investigated. The problem is to position the gripper at a requested relative distance in front of an object with an unknown location. For this purpose the gripper is equipped with a range camera giving the distance to surrounding objects within, ~ 1% and with a sampling rate above 1kHz. The range measurements are used in combination with internal angle measurements from joint encoders to estimate both the flexibility in the mechanical construction and the relative distance from gripper to object. For the motion control of the manipulator, a time scaled feedback controller is suggested. A fast inner loop is used to damp out oscillations and reject disturbances both from the platform and the manipulator. An outer control loop, with a lower closed loop bandwidth, then steers the gripper, based on the range measurements, to the requested final position in front of the object. This loop assumes a stationary rigid platform, and a rigid manipulator. At this moment only simulations of a flexible manipulator on a rigid platform have been studied. However, the results show that the flexibility can be estimated from indirect measurements of the range to the object and the joint angles. Also, good damping and disturbance rejection is achieved as long as the bandwidth of the actuators is sufficiently high, compared to the oscillation. The use of range measurements of the surrounding objects makes the positioning task very robust with respect to an uncertain platform position.
The goals of Modular automation Concepts (MAC) for the automation field are presented. In order to demonstrate the strategies, the packaging automation industry is reviewed to find new opportunities for production mac...
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作者：
Derby, StephenCooper, ClayDirector
Mechatronics and Assembly Lab New York State Center for Advanced Technology in Automation D Robotics and Manufacturing Rensselaer Polytechnic Institute TroyNY12180 United States American Dixie Group
Inc. 25 Industrial Park Drive Albany NY12206 United States
Teaching a course on Modular automation Concepts (MAC) for the automation field has been twice accomplished. In order to demonstrate the MAC strategies, the packaging automation industry is reviewed to find new opport...
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Extends the kinematic manipulability concept commonly used for serial manipulators to general constrained rigid multibody systems. Examples of such systems include multiple cooperating manipulators, multiple fingers h...
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Extends the kinematic manipulability concept commonly used for serial manipulators to general constrained rigid multibody systems. Examples of such systems include multiple cooperating manipulators, multiple fingers holding a payload, multi-leg walking robots, and variable geometry trusses. Explicit formulas for velocity and force manipulability ellipsoids are derived and their duality explained. The concept of unstable grasp and manipulable grasp are also extended and illustrated with examples.
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