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Biologically-inspired Motion Control for Kinematic Redundancy Resolution and Self-sensing Exploitation for Energy Conservation in Electromagnetic DevicesBabakeshizadeh, Vahid January 2014 (has links)
This thesis investigates particular topics in advanced motion control of two distinct
mechanical systems: human-like motion control of redundant robot manipulators
and advanced sensing and control for energy-efficient operation of electromagnetic
devices.
Control of robot manipulators for human-like motions has been one of challenging
topics in robot control for over half a century. The first part of this thesis
considers methods that exploits robot manipulators??? degrees of freedom for such
purposes. Jacobian transpose control law is investigated as one of the well-known
controllers and sufficient conditions for its universal convergence are derived by
using concepts of ???stability on a manifold??? and ???transferability to a sub-manifold???.
Firstly, a modification on this method is proposed to enhance the rectilinear trajectory
of the robot end-effector. Secondly, an abridged Jacobian controller is
proposed that exploits passive control of joints to reduce the attended degrees of
freedom of the system. Finally, the application of minimally-attended controller
for human-like motion is introduced.
Electromagnetic (EM) access control systems are one of growing electronic systems
which are used in applications where conventional mechanical locks may not
guarantee the expected safety of the peripheral doors of buildings. In the second
part of this thesis, an intelligent EM unit is introduced which recruits the selfsensing
capability of the original EM block for detection purposes. The proposed
EM device optimizes its energy consumption through a control strategy which
regulates the supply to the system upon detection of any eminent disturbance.
Therefore, it draws a very small current when the full power is not needed. The
performance of the proposed control strategy was evaluated based on a standard
safety requirement for EM locking mechanisms. For a particular EM model, the
proposed method is verified to realize a 75% reduction in the power consumption.
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Motion Control of Under-actuated Aerial Robotic ManipulatorsJafarinasab, Mohammad January 2018 (has links)
This thesis presents model-based adaptive motion control algorithms for under-actuated
aerial robotic manipulators combining a conventional multi-rotor Unmanned Aerial Vehicle
(UAV) and a multi-link serial robotic arm. The resulting control problem is quite
challenging due to the complexity of the combined system dynamics, under-actuation, and
possible kinematic redundancy. The under-actuation imposes second-order nonholonomic
constraints on the system motion and prevents independent control of all system degrees
of freedom (DOFs). Desired reference trajectories can only be provided for a selected
group of independent DOFs, whereas the references for the remaining DOFs must be determined such that they are consistent with the motion constraints. This restriction prevents
the application of common model-based control methods to the problem of this thesis. Using
insights from the system under-actuated dynamics, four motion control strategies are
proposed which allow for semi-autonomous and fully-autonomous operation. The control
algorithm is fully developed and presented for two of these strategies; its development for
the other two configurations follows similar steps and hence is omitted from the thesis.
The proposed controllers incorporate the combined dynamics of the UAV base and the serial
arm, and properly account for the two degrees of under-actuation in the plane of the
propellers. The algorithms develop and employ the second-order nonholonomic constraints
to numerically determine motion references for the dependent DOFs which are consistent with the motion constraints. This is a unique feature of the motion control algorithms
in this thesis which sets them apart from all other prior work in the literature of UAVmanipulators.
The control developments follow the so-called method of virtual decomposition,
which by employing a Newtonian formulation of the UAV-Manipulator dynamics,
sidesteps the complexities associated with the derivation and parametrization of a lumped
Lagrangian dynamics model. The algorithms are guaranteed to produce feasible control
commands as the constraints associated with the under-actuation are explicitly considered
in the control calculations. A method is proposed to handle possible kinematic redundancy
in the presence of second-order motion constraints. The control design is also extended to
include the propeller dynamics, for cases that such dynamics may significantly impact the
system response. A Lyapunov analysis demonstrates the stability of the overall system and
the convergence of the motion tracking errors. Experimental results with an octo-copter integrated with a 3 DOF robotic manipulator show the effectiveness of the proposed control strategies. / Thesis / Doctor of Philosophy (PhD)
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