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oai:www.ideals.illinois.edu:2142/81362 2023-07-11 col_2142_5131 col_2142_8888 com_2142_5130 com_2142_8887 com_2142_234

M. Tamer Basar Toussaint, Gregory James 2015-09-25T20:10:44Z 2015-09-25T20:10:44Z 10000-01-01 2000 2000 This thesis presents new techniques for planning and robustly controlling the motion of nonlinear underactuated vehicles when disturbances are present and only imperfect state measurements are available for feedback. The basic motion planning algorithm uses cubic splines or Pythagorean hodograph curves to connect the initial and final configurations and to generate a feasible trajectory for the system. The feasible trajectory and its control inputs are improved through an iterative Hinfinity-filter. Techniques are demonstrated for generalizing the motion planning algorithm to address the obstacle avoidance, multiple vehicle, and minimum distance planning problems. To track a desired trajectory, first a state feedback control law is developed for the linearized system using an H infinity-optimal design. The state feedback controller produces a locally exponentially stable closed-loop system and guarantees a precomputable level of disturbance attenuation for the system. Subsequently, an imperfect state measurement feedback controller is developed by combining a state estimate with the state feedback control law. The state estimator exploits a unique structure in the nonlinear equations of motion to decompose the system into two interlaced subsystems, which leads to a direct solution. The estimator is actually an Hinfinity-filter, and under it the controller achieves a modified form of disturbance attenuation. Simulations included in the thesis illustrate the motion planning, the state feedback control, and the imperfect state measurement control algorithms derived, for selected models of nonlinear underactuated vehicles. Made available in DSpace on 2015-09-25T20:10:44Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 9990169.pdf: 7319976 bytes, checksum: 31d68ac0f60fd8d8d4da891433267ce2 (MD5) Previous issue date: 2000 Embargo set by: Seth Robbins for item 82643 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs U of I Only 152 p. Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2000. http://hdl.handle.net/2142/81362 (MiAaPQ)AAI9990169 eng Engineering, System Science Robust Control and Motion Planning for Nonlinear Underactuated Systems Using H -Infinity Techniques text Electrical Engineering Electrical Engineering University of Illinois at Urbana-Champaign Dissertation Ph.D.