105 research outputs found
Asymptotic Vision-Based Tracking Control of the Quadrotor Aerial Vehicle
This paper proposes an image-based visual servo (IBVS) controller for the 3D translational
motion of the quadrotor unmanned aerial vehicle (UAV). The main purpose of this paper is to
provide asymptotic stability for vision-based tracking control of the quadrotor in the presence
of uncertainty in the dynamic model of the system. The aim of the paper also includes the use
of
ow of image features as the velocity information to compensate for the unreliable linear
velocity data measured by accelerometers. For this purpose, the mathematical model of the
quadrotor is presented based on the optic
ow of image features which provides the possibility
of designing a velocity-free IBVS controller with considering the dynamics of the robot. The
image features are de ned from a suitable combination of perspective image moments without
using the model of the object. This property allows the application of the proposed controller
in unknown places. The controller is robust with respect to the uncertainties in the transla-
tional dynamics of the system associated with the target motion, image depth and external
disturbances. Simulation results and a comparison study are presented which demonstrate the
e ectiveness of the proposed approach
Asymptotic Vision-Based Tracking Control of the Quadrotor Aerial Vehicle
This paper proposes an image-based visual servo (IBVS) controller for the 3D translational
motion of the quadrotor unmanned aerial vehicle (UAV). The main purpose of this paper is to
provide asymptotic stability for vision-based tracking control of the quadrotor in the presence
of uncertainty in the dynamic model of the system. The aim of the paper also includes the use
of
ow of image features as the velocity information to compensate for the unreliable linear
velocity data measured by accelerometers. For this purpose, the mathematical model of the
quadrotor is presented based on the optic
ow of image features which provides the possibility
of designing a velocity-free IBVS controller with considering the dynamics of the robot. The
image features are de ned from a suitable combination of perspective image moments without
using the model of the object. This property allows the application of the proposed controller
in unknown places. The controller is robust with respect to the uncertainties in the transla-
tional dynamics of the system associated with the target motion, image depth and external
disturbances. Simulation results and a comparison study are presented which demonstrate the
e ectiveness of the proposed approach
Asymptotic Vision-Based Tracking Control of the Quadrotor Aerial Vehicle
This paper proposes an image-based visual servo (IBVS) controller for the 3D translational
motion of the quadrotor unmanned aerial vehicle (UAV). The main purpose of this paper is to
provide asymptotic stability for vision-based tracking control of the quadrotor in the presence
of uncertainty in the dynamic model of the system. The aim of the paper also includes the use
of
ow of image features as the velocity information to compensate for the unreliable linear
velocity data measured by accelerometers. For this purpose, the mathematical model of the
quadrotor is presented based on the optic
ow of image features which provides the possibility
of designing a velocity-free IBVS controller with considering the dynamics of the robot. The
image features are de ned from a suitable combination of perspective image moments without
using the model of the object. This property allows the application of the proposed controller
in unknown places. The controller is robust with respect to the uncertainties in the transla-
tional dynamics of the system associated with the target motion, image depth and external
disturbances. Simulation results and a comparison study are presented which demonstrate the
e ectiveness of the proposed approach
θ-D Approximation Technique for Nonlinear Optimal Speed Control Design of Surface-Mounted PMSM Drives
This paper proposes nonlinear optimal controller
and observer schemes based on a θ-D approximation approach
for surface-mounted permanent magnet synchronous motors
(PMSMs). By applying the θ-D method in both the controller
and observer designs, the unsolvable Hamilton–Jacobi–Bellman
equations are switched to an algebraic Riccati equation and statedependent
Lyapunov equations (SDLEs). Then, through selecting
the suitable coefficient matrices, the SDLEs become algebraic, so
the complex matrix operation technique, i.e., the Kronecker product
applied in the previous papers to solve the SDLEs is eliminated.
Moreover, the proposed technique not only solves the problem of
controlling the large initial states, but also avoids the excessive
online computations. By utilizing a more accurate approximation
method, the proposed control system achieves superior control performance
(e.g., faster transient response, more robustness under
the parameter uncertainties and load torque variations) compared
to the state-dependent Riccati equation-based control method and
conventional PI controlmethod. The proposed observer-based control
methodology is tested with an experimental setup of a PMSM
servo drive using a Texas Instruments TMS320F28335 DSP. Finally,
the experimental results are shown for proving the effectiveness
of the proposed control approac
Design and Analysis of a Generalized High-Order Disturbance Observer for PMSMs with a Fuzy-PI Speed Controller
This paper proposes a generalized high-order observer for estimating total disturbance of permanent magnet synchronous motors (PMSMs). This total disturbance is dominated by load torque but also includes many other terms such as frictions, viscous force, Eddy and flux pulling forces, and noises. Comprehensive experimental results and analyses under various scenarios will be presented to find the appropriate order of the observer. We will compare the performance of zero-order observer (ZDO), first-order observer (FDO), and second-order observer (SDO) under three different scenarios of load torque..
Assessing the effects of time-dependent restrictions and control actions to flatten the curve of COVID-19 in Kazakhstan
This paper presents the assessment of time-dependent national-level
restrictions and control actions and their effects in fighting the COVID-19
pandemic. By analysing the transmission dynamics during the first wave of
COVID-19 in the country, the effectiveness of the various levels of control
actions taken to flatten the curve can be better quantified and understood.
This in turn can help the relevant authorities to better plan for and control
the subsequent waves of the pandemic. To achieve this, a deterministic
population model for the pandemic is firstly developed to take into
consideration the time-dependent characteristics of the model parameters,
especially on the ever-evolving value of the reproduction number, which is one
of the critical measures used to describe the transmission dynamics of this
pandemic. The reproduction number alongside other key parameters of the model
can then be estimated by fitting the model to real-world data using numerical
optimisation techniques or by inducing ad-hoc control actions as recorded in
the news platforms. In this paper, the model is verified using a case study
based on the data from the first wave of COVID-19 in the Republic of
Kazakhstan. The model is fitted to provide estimates for two settings in
simulations; time-invariant and time-varying (with bounded constraints)
parameters. Finally, some forecasts are made using four scenarios with
time-dependent control measures so as to determine which would reflect on the
actual situations better.Comment: 35 pages, 7 figures, To appear in Peer
θ-D Approximation Technique for Nonlinear Optimal Speed Control Design of Surface-Mounted PMSM Drives
This paper proposes nonlinear optimal controller
and observer schemes based on a θ-D approximation approach
for surface-mounted permanent magnet synchronous motors
(PMSMs). By applying the θ-D method in both the controller
and observer designs, the unsolvable Hamilton–Jacobi–Bellman
equations are switched to an algebraic Riccati equation and statedependent
Lyapunov equations (SDLEs). Then, through selecting
the suitable coefficient matrices, the SDLEs become algebraic, so
the complex matrix operation technique, i.e., the Kronecker product
applied in the previous papers to solve the SDLEs is eliminated.
Moreover, the proposed technique not only solves the problem of
controlling the large initial states, but also avoids the excessive
online computations. By utilizing a more accurate approximation
method, the proposed control system achieves superior control performance
(e.g., faster transient response, more robustness under
the parameter uncertainties and load torque variations) compared
to the state-dependent Riccati equation-based control method and
conventional PI controlmethod. The proposed observer-based control
methodology is tested with an experimental setup of a PMSM
servo drive using a Texas Instruments TMS320F28335 DSP. Finally,
the experimental results are shown for proving the effectiveness
of the proposed control approac
An Electromagnetic Steering System for Magnetic Nanoparticle Drug Delivery
Targeted delivery of pharmaceutical agents to
the brain using magnetic nanoparticles (MNPs) is an
efficient technique to transport molecules to disease
locations. MNPs can cross the blood–brain barrier (BBB)
and can be concentrated at a specific location in the brain
using non-invasive electromagnetic forces. The proposed
EMA consists of two coil-core system. The cores are
added in the center of each coil to concentrate the flux in
the region of interest. The EMA can enhance the gradient
field 10 times compared to only coil system and generate
the maximum magnetic field of 160 mT and 5.6 T/m. A
12-kW direct-current power supply was used to generate
sufficient magnetic forces on the MNPs by regulating the
input currents of the coils. Effective guidance of MNPs is
demonstrated via simulations and experiments using
800-nm-diameter MNPs in a Y-shaped channel. The
developed EMA system has high potentials to increase
BBB crossing of MNPs for efficient drug targeting to
brain region
Functionalized Magnetic Force Enhances Magnetic Nanoparticle Guidance: From Simulation to Crossing of the Blood-Brain Barrier in vivo
In recent studies, we introduced the concept of functionalized magnetic force as a method to prevent nanoparticles from sticking to
vessel walls caused by extensive simulation and in vitro experiments involving a Y-shaped channel. In this study, we further
investigated the effectiveness of the functionalized magnetic force with a realistic 3D vessel through simulations. For the simulations,
we considered a more realistic continuous injection of particles with different magnetic forces and frequencies. Based on the results
from our simulation studies, we performed in vivo mice experiments to evaluate the effectiveness of using a functionalized magnetic
force to aid magnetic nanoparticles (MNPs) in crossing the blood-brain barrier (BBB). To implement the functionalized magnetic
force, we developed an electromagnetic actuator regulated by a programmable direct current (DC) power supply. Our results indicate
that a functionalized magnetic field can effectively prevent MNPs from sticking, and also guide them across the BBB. We used 770-nm
fluorescent carboxyl MNPs in this study. Following intravenous administration of MNPs into mice, we applied an external magnetic
field (EMF) to mediate transport of the MNPs across the BBB and into the brain. Furthermore, we evaluated the differential effects of
functionalized magnetic fields (0.25, 0.5, and 1 Hz) and constant magnetic fields on the transport of MNPs across the BBB. Our results
showed that a functionalized magnetic field is more effective than a constant magnetic field in the transport and uptake of MNPs
across the BBB in mice. Specifically, applying a functionalized magnetic field with a 3 A current and 0.5 Hz frequency mediated the
greatest transport and uptake of MNPs across the BBB in mic
Functionalized Magnetic Force Enhances Magnetic Nanoparticle Guidance: From Simulation to Crossing of the Blood-Brain Barrier in vivo
In recent studies, we introduced the concept of functionalized magnetic force as a method to prevent nanoparticles from sticking to
vessel walls caused by extensive simulation and in vitro experiments involving a Y-shaped channel. In this study, we further
investigated the effectiveness of the functionalized magnetic force with a realistic 3D vessel through simulations. For the simulations,
we considered a more realistic continuous injection of particles with different magnetic forces and frequencies. Based on the results
from our simulation studies, we performed in vivo mice experiments to evaluate the effectiveness of using a functionalized magnetic
force to aid magnetic nanoparticles (MNPs) in crossing the blood-brain barrier (BBB). To implement the functionalized magnetic
force, we developed an electromagnetic actuator regulated by a programmable direct current (DC) power supply. Our results indicate
that a functionalized magnetic field can effectively prevent MNPs from sticking, and also guide them across the BBB. We used 770-nm
fluorescent carboxyl MNPs in this study. Following intravenous administration of MNPs into mice, we applied an external magnetic
field (EMF) to mediate transport of the MNPs across the BBB and into the brain. Furthermore, we evaluated the differential effects of
functionalized magnetic fields (0.25, 0.5, and 1 Hz) and constant magnetic fields on the transport of MNPs across the BBB. Our results
showed that a functionalized magnetic field is more effective than a constant magnetic field in the transport and uptake of MNPs
across the BBB in mice. Specifically, applying a functionalized magnetic field with a 3 A current and 0.5 Hz frequency mediated the
greatest transport and uptake of MNPs across the BBB in mic
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