Brian J. Driessen

Bio: Brian J. Driessen is an academic researcher from Wichita State University. The author has contributed to research in topics: Control theory & Tracking error. The author has an hindex of 12, co-authored 58 publications receiving 500 citations. Previous affiliations of Brian J. Driessen include Sandia National Laboratories & University of Alabama in Huntsville.

Command shaping control of an operator-in-the-loop boom crane

Abstract: This paper presents a control method for suppressing payload sway caused by operator commanded maneuvers, in rotary boom cranes. The crane configuration studied, consists of a payload mass that swings at the end of a spherical pendulum, which is attached to a boom capable of hub rotation and elevation. Positioning of the rotary crane is accomplished through the hub and boom angles, and the lift line length. Since the configuration of the crane affects the excitation and response of the lift line, the sway control scheme must account for the varying geometry of the system. Adaptive forward path command filters are employed to remove the components of the command signal which induce oscillation of the lift line. A real-time operator-in-the-loop simulation, is used to demonstrate results for a simultaneous three-axis maneuver.

Analyzing the Multiple-target-multiple-agent Scenario Using Optimal Assignment Algorithms

Abstract: This work considers the problem of maximum utilization of a set of mobile robots with limited sensor-range capabilities and limited travel distances. The robots are initially in random positions. A set of robots properly guards or covers a region if every point within the region is within the effective sensor range of at least one vehicle. We wish to move the vehicles into surveillance positions so as to guard or cover a region, while minimizing the maximum distance traveled by any vehicle. This problem can be formulated as an assignment problem, in which we must optimally decide which robot to assign to which slot of a desired matrix of grid points. The cost function is the maximum distance traveled by any robot. Assignment problems can be solved very efficiently. Solution times for one hundred robots took only seconds on a Silicon Graphics Crimson workstation. The initial positions of all the robots can be sampled by a central base station and their newly assigned positions communicated back to the robots. Alternatively, the robots can establish their own coordinate system with the origin fixed at one of the robots and orientation determined by the compass bearing of another robot relative to this robot. This paper presents example solutions to the multiple-target-multiple-agent scenario using a matching algorithm. Two separate cases with one hundred agents in each were analyzed using this method. We have found these mobile robot problems to be a very interesting application of optimal assignment algorithms, and we expect this to be a fruitful area for future research.

Salinas - User's Notes

Abstract: Salinas provides a massively parallel implementation of structural dynamics finite element analysis, required for high fidelity, validated models used in modal, vibration, static and shock analysis of weapons systems. This document provides a users guide to the input for Salinas. Details of input specifications for the different solution types, output options, element types and parameters are included. The appendices contain detailed examples, and instructions for running the software on parallel platforms.

Globally exponential controller/observer for tracking in robots without velocity measurement

Abstract: In this work, we present an observer and continuous controller for a multiple degree of freedom robotic plant without velocity measurement. For this considered plant, we propose and present an observer/controller that estimates or observes the velocity and drives the position tracking error to zero. We prove that the combined tracking error and observer error converges to zero globally exponentially and that all closed loop signals remain bounded. A contribution of the present paper, as compared to previous work for this same plant, can be deemed to be the globally-exponential convergence of the present paper versus the semi-globally exponential and globally asymptotic results of previous papers. To the best of our knowledge, the present paper is the first proven globally-exponential result for this plant and also the first global result for which the size of the control torque does not increase exponentially with respect to the size of the tracking error. The control torque is continuous; however, the time derivative of the velocity estimate is discontinuous but only at isolated time instants. No sliding modes are used. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society

Operator in-the-loop control of rotary cranes

Abstract: An open-loop control method is presented for reducing the oscillatory motion of rotary crane payloads during operator commanded maneuvers. A typical rotary crane consists of a multiple degree-of-freedom platform for positioning a spherical pendulum with an attached payload. The crane operator positions the Payload by issuing a combination of translational and rotational commands to the platform as well as load-line length changes. Frequently, these pendulum modes are time-varying and exhibit low natural frequencies. Maneuvers are therefore performed at rates sufficiently slow so as not to excite oscillation. The strategy presented here generates crane commands which suppress vibration of the payload without a priori knowledge of the desired maneuver. Results are presented for operator in-the-loop positioning using a real-time dynamics simulation of a three-axis rotary crane where the residual sway magnitude is reduced in excess of 4OdB.

Iterative Learning Control: Brief Survey and Categorization

Abstract: In this paper, the iterative learning control (ILC) literature published between 1998 and 2004 is categorized and discussed, extending the earlier reviews presented by two of the authors. The papers includes a general introduction to ILC and a technical description of the methodology. The selected results are reviewed, and the ILC literature is categorized into subcategories within the broader division of application-focused and theory-focused results.

Dynamics and Control of Cranes: A Review:

Abstract: We review crane models available in the literature, classify them, and discuss their applications and limitations. A generalized formulation of the most widely used crane model is analyzed using th...

A Preconditioner for Substructuring Based on Constrained Energy Minimization

Abstract: A preconditioner for substructuring based on constrained energy minimization concepts is presented. The preconditioner is applicable to both structured and unstructured meshes and offers a straightforward approach for the iterative solution of second- and fourth-order structural mechanics problems. The approach involves constraints associated with disjoint sets of nodes on substructure boundaries. These constraints provide the means for preconditioning at both the substructure and global levels. Numerical examples are presented that demonstrate the good performance of the method in terms of iterations, compute time, and condition numbers of the preconditioned equations.

Command shaping for flexible systems: A review of the first 50 years

Abstract: The control of flexible systems is a large and important field of study. Unwanted transient deflection and residual vibration are detrimental to many systems ranging from nano-positioning devices to large industrial cranes. Thousands of researchers have worked diligently for decades to provide solutions to the challenging problems posed by flexible dynamic systems. The work can roughly be broken into three categories:1) Hardware design, 2) Feedback control, and 3) Command shaping. This paper provides a review of command-shaping research since it was first proposed in the late 1950’s. The important milestones of the research advancements, as well as application examples, are used to illustrate the developments in this important research field.