4,936 research outputs found
SMC based bilateral control
Design of a motion control system should take into account (a) unconstrained motion performed without interaction with environment or other system, and
(b) constrained motion with system in contact with environment or another system or has certain functional interaction with another system. Control in both cases can be formulated in terms of maintaining desired system configuration what makes essentially the same structure for common tasks: trajectory tracking, interaction force control, compliance control etc. It will be shown that the same design approach can be used for systems that maintain some functional relation – like bilateral or multilateral systems, relation among mobile robots or control of haptic systems.
SMC framework in motion control systems
Design of a motion control system should take into account both the unconstrained motion performed without interaction with environment or other system, and the constrained motion where system is in contact with environment or has certain functional interaction with another system. In this paper control systems design approach, based on siding mode methods, that allows selection of control for generic tasks as trajectory and/or force tracking as well as for systems that require maintain some functional relation like bilateral or multilateral systems, establisment of virtual relation among mobile robots or control of haptic systems is presented. It is shown that all basic motion control problems - trajectory tracking, force control, hybrid position/force control scheme and the impedance control - can be treated in the same way while avoiding the structural change of the controller and guarantying stable behavior of the system In order to show applicability of the proposed techniques simulation and experimental results for high precision systems in microsystems assembly tasks and bilateral control systems are presente
Robot Impedance Control and Passivity Analysis with Inner Torque and Velocity Feedback Loops
Impedance control is a well-established technique to control interaction
forces in robotics. However, real implementations of impedance control with an
inner loop may suffer from several limitations. Although common practice in
designing nested control systems is to maximize the bandwidth of the inner loop
to improve tracking performance, it may not be the most suitable approach when
a certain range of impedance parameters has to be rendered. In particular, it
turns out that the viable range of stable stiffness and damping values can be
strongly affected by the bandwidth of the inner control loops (e.g. a torque
loop) as well as by the filtering and sampling frequency. This paper provides
an extensive analysis on how these aspects influence the stability region of
impedance parameters as well as the passivity of the system. This will be
supported by both simulations and experimental data. Moreover, a methodology
for designing joint impedance controllers based on an inner torque loop and a
positive velocity feedback loop will be presented. The goal of the velocity
feedback is to increase (given the constraints to preserve stability) the
bandwidth of the torque loop without the need of a complex controller.Comment: 14 pages in Control Theory and Technology (2016
Function based control for bilateral systems in tele-micromanipulation
Design of a motion control system should take into
account (a) unconstrained motion performed without interaction
with environment or any other system, and (b) constrained
motion with system in contact with environment or other systems.
Control in both cases can be formulated in terms of maintaining
desired system configuration what makes essentially the same
structure for common tasks: trajectory tracking, interaction force
control, compliance control etc. The same design approach can be
used to formulate control in bilateral systems aimed to maintain
desired functional relations between human and environment
through master and slave motion systems. Implementation of
the methodology is currently being pursued with a custom built
Tele-micromanipulation setup and preliminary results concerning
force/position tracking and transparency between master and
slave are clearly demonstrated
DSOGI-PLL based power control method to mitigate control errors under disturbances of grid connected hybrid renewable power systems
The control of power converter devices is
one of the main research lines in interfaced renewable
energy sources, such as solar cells and wind turbines.
Therefore, suitable control algorithms should be
designed in order to regulate power or current properly
and attain a good power quality for some disturbances,
such as voltage sag/swell, voltage unbalances and fluctuations,
long interruptions, and harmonics. Various
synchronisation techniques based control strategies
are implemented for the hybrid power system applications
under unbalanced conditions in literature studies.
In this paper, synchronisation algorithms based
Proportional-Resonant (PR) power/current controller
is applied to the hybrid power system (solar cell + wind
turbine + grid), and Dual Second Order Generalized
Integrator-Phase Locked Loop (DSOGI-PLL) based PR
controller in stationary reference frame provides a solution
to overcome these problems. The influence of
various cases, such as unbalance, and harmonic conditions,
is examined, analysed and compared to the PR
controllers based on DSOGI-PLL and SRF-PLL. The
results verify the effectiveness and correctness of the
proposed DSOGI-PLL based power control method
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