scholarly journals A Study on Vision-Based Backstepping Control for a Target Tracking System

Actuators ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 105
Author(s):  
Thinh Huynh ◽  
Minh-Thien Tran ◽  
Dong-Hun Lee ◽  
Soumayya Chakir ◽  
Young-Bok Kim
Keyword(s):  
Control System ◽  
Visual Servoing ◽  
Tracking System ◽  
Experimental Studies ◽  
Imaging Geometry ◽  
Control Scheme ◽  
Decoupled Control ◽  
Control Configuration ◽  
A New Technique ◽  
Pointing Control

This paper proposes a new method to control the pose of a camera mounted on a two-axis gimbal system for visual servoing applications. In these applications, the camera should be stable while its line-of-sight points at a target located within the camera’s field of view. One of the most challenging aspects of these systems is the coupling in the gimbal kinematics as well as the imaging geometry. Such factors must be considered in the control system design process to achieve better control performances. The novelty of this study is that the couplings in both mechanism’s kinematics and imaging geometry are decoupled simultaneously by a new technique, so popular control methods can be easily implemented, and good tracking performances are obtained. The proposed control configuration includes a calculation of the gimbal’s desired motion taking into account the coupling influence, and a control law derived by the backstepping procedure. Simulation and experimental studies were conducted, and their results validate the efficiency of the proposed control system. Moreover, comparison studies are conducted between the proposed control scheme, the image-based pointing control, and the decoupled control. This proves the superiority of the proposed approach that requires fewer measurements and results in smoother transient responses.

Implementation of a real-time moving object tracking system using visual servoing

Robotica ◽  
2003 ◽  
Vol 21 (6) ◽  
pp. 615-625 ◽  
Author(s):  
M-C. Tsai ◽  
K-Y. Chen ◽  
M-Y. Cheng ◽  
K.C. Lin
Keyword(s):  
Real Time ◽  
Visual Servoing ◽  
Tracking System ◽  
Moving Target ◽  
Tracking Accuracy ◽  
Security Systems ◽  
Detection Techniques ◽  
Control Scheme ◽  
High System ◽  
Automatically Tracking

Due to the increasing popularity of surveillance and security systems, the problem of automatically tracking a moving target by visual servoing has become a research topic deserving more investigation. Nonetheless, the success of tracking a moving target in real-time primarily depends on the performance of the motion detection techniques employed. This paper addresses visual tracking control of an unknown target that could be motional arbitrarily in the scene. A pan-tilt mechanism is used to gain the flexibility of tracking, and the so-called region-based matching method and motion energy method are modified and proposed in this study to detect a moving target based on the consecutive images acquired. A visual servo control scheme that adopts proportional control in the visual loop for reducing the servo lagging is proposed using output disturbance feedforward compensation. Experimental results show the superiority of the proposed method in achieving high system bandwidth and tracking accuracy.

Adaptive fuzzy Jacobian control of spacecraft combined attitude and Sun tracking system

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yew-Chung Chak ◽  
Renuganth Varatharajoo ◽  
Nima Assadian
Keyword(s):  
Attitude Control ◽  
Tracking System ◽  
Solar Array ◽  
The Sun ◽  
Solar Panels ◽  
Content Type ◽  
Adaptive Fuzzy ◽  
Control Scheme ◽  
Adaptation Law ◽  
Pointing Control

Purpose The paper aims to address the combined attitude control and Sun tracking problem in a flexible spacecraft in the presence of external and internal disturbances. The attitude stabilization of a flexible satellite is generally a challenging control problem, because of the facts that satellite kinematic and dynamic equations are inherently nonlinear, the rigid–flexible coupling dynamical effect, as well as the uncertainty that arises from the effect of actuator anomalies. Design/methodology/approach To deal with these issues in the combined attitude and Sun tracking system, a novel control scheme is proposed based on the adaptive fuzzy Jacobian approach. The augmented spacecraft model is then analyzed and the Lyapunov-based backstepping method is applied to develop a nonlinear three-axis attitude pointing control law and the adaptation law. Findings Numerical results show the effectiveness of the proposed adaptive control scheme in simultaneously tracking the desired attitude and the Sun. Practical implications Reaction wheels are commonly used in many spacecraft systems for the three-axis attitude control by delivering precise torques. If a reaction wheel suffers from an irreversible mechanical breakdown, then it is likely going to interrupt the mission, or even leading to a catastrophic loss. The pitch-axis mounted solar array drive assemblies (SADAs) can be exploited to anticipate such situation to generate a differential torque. As the solar panels are rotated by the SADAs to be orientated relative to the Sun, the pitch-axis wheel control torque demand can be compensated by the differential torque. Originality/value The proposed Jacobian control scheme is inspired by the knowledge of Jacobian matrix in the trajectory tracking of robotic manipulators.

Synchronization Control Scheme for Antenna Pointing Control System Based on Hybrid Linear Actuator

2014 ◽  
Vol 599-601 ◽  
pp. 1077-1080
Author(s):  
Peng Yao ◽  
Gang Liu ◽  
Yan Liu
Keyword(s):  
Control System ◽  
Time Synchronization ◽  
Synchronization Control ◽  
Piezo Actuator ◽  
Linear Actuator ◽  
Multiple Sensors ◽  
Control Scheme ◽  
Pointing Control ◽  
Hybrid Actuator ◽  
High Repeatability

To overcome the limitations of the independent stacked hybrid actuator with multiple sensors, a new hybrid linear actuator combines the advantages of both technologies: piezo actuator for extremely high accuracy and motorized stage for long travel ranges. A hybrid linear actuator prototype has been developed for testing in our satellite tracking antenna pointing control system. For the maximum absolute positioning accuracy, host positioning controller depends only on one common position sensor for both the coarse and fine positioning at the same time. Synchronization control scheme shows promising results for extremely small steps, high repeatability and good linearity over long travel ranges.

АКУСТИЧНА ПОМІТНІСТЬ БЕЗПІЛОТНИХ ЛІТАЛЬНИХ АПАРАТІВ З СИЛОВИМИ УСТАНОВКАМИ НА БАЗІ ПОРШНЕВИХ ДВИГУНІВ

2020 ◽  
pp. 62-80
Author(s):  
В. В. Руденко ◽  
И. В. Калужинов ◽  
Н. А. Андрущенко
Keyword(s):  
Control System ◽  
Internal Combustion Engine ◽  
Power Plants ◽  
Combustion Engine ◽  
Spectral Characteristics ◽  
Experimental Studies ◽  
Internal Combustion ◽  
Detection Range ◽  
Acoustic Signature ◽  
Static Conditions

The presence in operation of many prototypes of UAVs with propeller propellers, the use of such devices at relatively low altitudes and flight speeds makes the problem of noise reduction from UAVs urgent both from the point of view of acoustic imperceptibility and ecology.The aim of the work is to determine a set of methods that help to reduce the visibility of UAVs in the acoustic range. It is shown that the main source of noise from the UAV on the ground is the power plant, which includes the engine and the propeller. The parameters of the power plants influencing the processes that determine the acoustic signature of the UAV were investigated. A comprehensive analysis of the factors affecting visibility was carried out. The power plants include two-stroke and four-stroke engines, internal combustion and two-blade propellers. The use of silencers on the exhaust of the internal combustion engine was considered. The spectral characteristics of the acoustic fields of the propeller-driven power plants for the operating sample of the UAV "Eco" were obtained. The measurements were carried out in one-third octave and 1/48 octave frequency bands under static conditions. The venue is the KhAI airfield. Note that the propellers that were part of the power plants operated at Reynolds numbers (Re0,75<2*105), which can significantly affect its aerodynamic and acoustic characteristics. It is shown that when choosing a UAV control system, one should take into account the fact that two-stroke piston engines are the dominant source in the noise of propeller-driven control systems in the absence of a hood and mufflers in the intake and exhaust tracts. The use of a four-stroke internal combustion engine significantly reduces the noise of the control system. In the general case, the position of the boundaries of the zone of acoustic visibility of a UAV at the location of the observer is determined by the ratio between the intensity of acoustic radiation perceived by the observer from the UAV and the intensity of sound corresponding to the natural acoustic background and depends on the degree of manifestation of acoustic effects accompanying the propagation of sound in a turbulent atmosphere - the refraction of sound waves. Absorption and dissipation of acoustic energy. The calculation and comparison of the UAV detection range was carried out taking into account the existing natural maskers.The results of experimental studies are presented that allow assessing the degree of acoustic signature of the UAV. A set of measures aimed at reducing the intensity of the acoustic signature of the UAV in various regions of the radiation spectrum has been determined.

scholarly journals Distributed Attitude Synchronization for Spacecraft Formation Flying via Event-Triggered Control

2021 ◽  
Vol 11 (14) ◽  
pp. 6299
Author(s):  
Xiong Xie ◽  
Tao Sheng ◽  
Liang He
Keyword(s):  
Control System ◽  
Formation Flying ◽  
Spacecraft Formation ◽  
Spacecraft Formation Flying ◽  
Control Scheme ◽  
Event Triggering ◽  
Computational Resources ◽  
Update Frequency ◽  
Attitude Synchronization ◽  
Event Triggered

The distributed attitude synchronization control problem for spacecraft formation flying subject to limited energy and computational resources is addressed based on event-triggered mechanism. Firstly, a distributed event-driven controller is designed to achieve attitude coordination with the limitation of energy and computing resources. Under the proposed control strategy, the controller is only updated at the event triggering instants, which effectively reduces the update frequency. Subsequently, an event-triggered strategy is developed to further decrease energy consumption and the amount of computation. The proposed event-triggered function only requires the latest state information about its neighbors, implying that the trigger threshold does not need to be calculated continuously. It is shown that the triggering interval between two successive events is strictly positive, showing that the control system has no Zeno phenomenon. Moreover, the update frequency of the proposed controller can be reduced by more than 90% compared to the update frequency of the corresponding time-driven controller with an update frequency of 10 Hz by choosing appropriate control parameters and the control system can still achieve high-precision convergence. Finally, the effectiveness of the constructed control scheme is verified by numerical simulations.

scholarly journals Optical Inspection Systems for Axisymmetric Parts with Spatial 2D Resolution

Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1218
Author(s):  
Aleksandr Kulchitskiy
Keyword(s):  
Control System ◽  
Optical System ◽  
Measurement Accuracy ◽  
Experimental Studies ◽  
Digital Camera ◽  
Digital Cameras ◽  
Bodies Of Revolution ◽  
Optical Inspection ◽  
Inspection Systems ◽  
Projection Error

The article proposes a solution to the problem of increasing the accuracy of determining the main shaping dimensions of axisymmetric parts through a control system that implements the optical method of spatial resolution. The influence of the projection error of a passive optical system for controlling the geometric parameters of bodies of revolution from the image of its sections, obtained by a digital camera with non-telecentric optics, on the measurement accuracy is shown. Analytical dependencies are derived that describe the features of the transmission of measuring information of a system with non-telecentric optics in order to estimate the projection error. On the basis of the obtained dependences, a method for compensating the projection error of the systems for controlling the geometry of the main shaping surfaces of bodies of revolution has been developed, which makes it possible to increase the accuracy of determining dimensions when using digital cameras with a resolution of 5 megapixels or more, equipped with short-focus lenses. The possibility of implementing the proposed technique is confirmed by the results of experimental studies.

Independent wheel control system design for highly automated driving

2021 ◽  
pp. 095440702110065
Author(s):  
Shihuan Li ◽  
Lei Wang
Keyword(s):  
Control System ◽  
Control Method ◽  
Autonomous Driving ◽  
Control System Design ◽  
Steering Control ◽  
Automated Driving ◽  
Accuracy And Precision ◽  
Actual Observation ◽  
Control Scheme ◽  
Interference Measurement

For L4 and above autonomous driving levels, the automatic control system has been redundantly designed, and a new steering control method based on brake has been proposed; a new dual-track model has been established through multiple driving tests. The axle part of the model was improved, the accuracy of the transfer function of the model was verified again through acceleration-slide tests; a controller based on interference measurement was designed on the basis of the model, and the relationships between the controller parameters was discussed. Through the linearization of the controller, the robustness of uncertain automobile parameters is discussed; the control scheme is tested and verified through group driving test, and the results prove that the accuracy and precision of the controller meet the requirements, the robustness stability is good. Moreover, the predicted value of the model fits well with the actual observation value, the proposal of this method provides a new idea for avoiding car out of control.

Design of Electric Control System of Stainless Steel Composite Plate

2013 ◽  
Vol 706-708 ◽  
pp. 716-719
Author(s):  
Jian Chu ◽  
Gang Wang
Keyword(s):  
Stainless Steel ◽  
Control System ◽  
Composite Plate ◽  
Current Control ◽  
Equipment Operation ◽  
Electric Control ◽  
Control Scheme ◽  
Steel Composite ◽  
Machine Interface ◽  
Electrical Components

This paper mainly introduced to the PLC as the core of stainless steel composite plate electric control part of the design. The system uses the converter +PLC+ man-machine interface, as the major part of roll welding machine control, because of the use of the PLC, so that the system can improve the automatic level, electrical components is reduced, reduce failure rate, improve the reliability of equipment operation. Based on the current control and speed control, so that the welding quality and welding speed has been greatly improved. In the article, mainly from the production process, and the control system hardware and software design, and the control scheme to introduce several aspects.

scholarly journals Collective Losses of Low Power Cage Induction Motors—A New Approach

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1749
Author(s):  
Elzbieta Szychta ◽  
Leszek Szychta
Keyword(s):  
Control System ◽  
Experimental Studies ◽  
Complex Problem ◽  
Accurate Estimation ◽  
New Approach ◽  
Water Pumping ◽  
Efficiency Control ◽  
Interacting Systems ◽  
Cage Induction Motor ◽  
Selection Of

Energy efficiency of systems of water pumping is a complex problem since efficiency of two distinct interacting systems needs to be combined: water and power supply. This paper introduces a non-intrusive method of calculating the so-called “collective losses” of a cage induction motor. The term “collective losses”, which the authors define, allows for accurate estimation of motor efficiency. Control system of a pump determines operating point of a pumping station, and thus its efficiency. General estimated performance characteristics of a motor, components of a control system, are assumed to serve selection of a range of pumping speed variations. Rotational speed has a direct effect on motor load torque, pump power and head, and thus on motor performance. Hellwig’s statistical method was used to specify characteristics of estimated collective losses on the basis of experimental studies of 21 motors rated at up to 2.2 kW. The results of simulations and experiments are used to verify validity and efficiency of the suggested method. The method is non-intrusive, simple to use, and requires minimum data.

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