Underwater Flexible Manipulator Double-Loop Feedback Control Based on Built-in Binocular Vision and Displacement Sensor

Adaptive nonlinear vibration control of a Cartesian flexible manipulator driven by a ballscrew mechanism

In particular, it is useful to pay attention to control strategies to reduce energy consumption. In this article, the purpose is to regulate and control the temperature and humidity of the air in a room with specific dimensions. The dynamical equations of the HVAC system are presented as equations of temperature and humidity variation. A control system based on LQR optimal control method is designed for this air conditioning system including two heating and cooling operations. Then, after examining the stability of the system based on the Lyapunov stability criterion, and also a temperature control performance index is defined to express and compare the performance of control system with different gains. Finally, by performing the simulation, the control and HVAC system performance is evaluated with the help of defined performance index in the presence of designed algorithm which results show that LQR gains have direct effect on energy consumption and control system performance.

The wing-in-ground effect craft (WIG craft) is a kind of vehicle that flies close to the ground to achieve a flight with low aerodynamic drag and high lift. A robust and precise height control system is essential to ensure small WIG crafts fly safely in ground effect. In this paper, the performance of different high precision height control systems based on PID controllers is investigated numerically with different altitude disturbances. The results show that a control system that operates throttle, elevators, and flaps to control the altitude of the aircraft (TPF control system) results in the minimum overshoot, undershoot, rising tine, and settling time recovering from a disturbed altitude, with fluctuation in pitch angle. Compared to the TPF control system, even though the control system that operates throttle and flaps (TF control system) has a longer settling time and a higher overshoot, it has a smaller oscillation in pitch angle during a disturbed altitude. In addition, operating the throttle helps reduce the change of flight velocity during altitude disturbance. Furthermore, simulation results based on the TPF control system, show that the ground effect has little influence on the performance of control systems.

Flexible Manipulators (FMs) provide a number of benefits, containing reduced weight due to the thinness of the robot’s linkages. Although the initial plan was to use actual robots’ flexibility or slenderness to their advantage, the complex dynamics of the systems piqued interest in using an experimental flexible manipulator as a testing ground for various modeling or control strategies. A review is essential for researchers who want to align their study objectives with those of the field because the literature is extensive and diverse. Due to the widespread usage of flexible manipulators in different mechatronic and robotic applications over the past few decades, many academics worldwide are now interested in researching this topic. Studies are categorized here according to the control and modeling technologies of flexible manipulators and methodologies. Review of recent works on analysis, modeling, mechanical vibration, control algorithms, gyroscope technology and applications, difficulties in managing flexible manipulators and their anticipated future, and the majority of the notable evolutionary and optimization algorithms, including Genetic Algorithm (GA), Differential Evolution (DE), and Fuzzy Logic (FL), as well as modification approaches and techniques, are discussed and underlined. This study examines many publications, thoroughly reviewing the analytical, mathematical, dynamical modeling, mechanical vibration control techniques and most of the notable evolutionary and optimization algorithmic approaches of Robotic Flexible Manipulator (RFM) structures.

The J-TEXT newly deployed three-wave polarimeter-interferometer (POLARIS) system provides a better time and spatial resolution of the plasma electronic density than the old HCN interferometer system. The plasma electron density feedback control system is implemented on the already existing POLARIS DAQ system which is based on FlexRIO FPGA. Another FlexRIO board with an output module is added to implement the feedback control algorithm and feed the output to the piezoelectric crystal valve. The density feedback control system is able to extract the phase difference information from the intermedia frequency signal using FFT, calculate density of multiple channels and output control signal to the piezoelectric crystal valve in real-time. NI P2P technology is used to transfer processed data from a FlexRIO board to another in real-time without using the CPU. This system is also able to calculate density profile. With the density profile it can use compensated central chord line integrated or average density as control target. Also the real-time density profile data is useful for future plasma control system and disruption detection system.

In order to improve the traditional speed-tension type three-motor synchronous control platform based on PLC bus control to further enhance the speed and control accuracy of the control system, enhance the control effect, Speed-Tension type Three-motor coordinate synchronous control platform based on Multi-microprocessor is proposed in this paper.In this platform, the complex programmable logic devices (CPLD), Digital Signal Processor (DSP) and microcontroller (MCU) are combined.In order to improve rapid and synchronization of the control system, CPLD Parallel nature is used to achieve three serial ports synchronous and concurrency control; Complex control algorithms are implement by the use of DSP fast and efficient data processing capabilities; Experimental results show: The control system is stable, at the same baud rate the control speed of the platform based on multi-microprocessor is more than three times faster than the one of the traditional PLC bus control platform.In the multi-microprocessor control platform， under the same control algorithm regulation time is more fast 0.53 seconds than traditional PLC control platform, the overshoot of the system is 13.53% of the one using traditional PLC control platform, and the tracking the maximum error reduces 60.53% than the one of the traditional PLC control platform.

To overcome productivity issues and revolutionize the stagnating construction industry, a large amount of research efforts has been devoted to robot-assisted construction technology. The advancements in robotics including mechanical system design, tool design, digital system design, and numerical control systems design enabled engineers to create complex geometries that are infeasible for conventional construction methods. In addition, innovative robotic systems that utilize mobile platforms, multiple robots, and unmanned aerial vehicles have demonstrated significant promise in fully automating the construction process. This work will provide a perspective on the state-of-the-art applications of robotics in the revolution of construction, where a comprehensive review of the current development of the relevant software and hardware, 3D concrete printing (3DCP), robot-assisted assembly of discrete prefabricated blocks, real-time quality monitoring and feedback control systems, and typical innovative robot-assisted structural designs are conducted. Finally, the limitations of existing robot-assisted construction technology are identified, which leads to several recommendations for future research toward fully automatic construction.

Objectives. The problem of functional verification of control devices with respect to their design specification is considered. When solving the problems of implementing and testing of discrete systems, one has to deal with the presence of parallelism in the behavior of interacting control objects, which is also displayed in the assignment for designing control systems. The aim of the work is to develop a method for simulating descriptions of such systems, which allows their behavior testing dynamically on the area limited by their possible functioning.Methods. The paper considers a class of control systems with parallelism of the processes occurring in them, which permits linearization of their execution. To specify the behavior of such control systems, it is proposed to use the PRALU language of parallel control algorithms, which is based on Petri nets and which allows to order events occurring during the device operation. An object-oriented approach to simulation of the description of the control algorithm at the transaction level is proposed. For this purpose, a TLM (Transaction-Level Modeling) model has been developed for describing the devices with behavior parallelism in PRALU language. The transaction level model describes a system as a set of interacting processes that run in parallel and determine the behavior of the system over time.Results. The key concepts of the TLM model for simulating the descriptions of control algorithms in the PRALU language are defined: data structure, transactions, processes, and a barrier mechanism for synchronization of parallel processes. A method is proposed for transforming the description of an algorithm in the language into a TLM model, which is based on the representation of language operations as compositions of elementary operations that are performed sequentially. The set of these operations forms the basis for the algorithmic decomposition of a parallel algorithm in PRALU language into intermediate language program that is executed strictly sequentially. Translators of this program into the Verilog and C languages have been developed, the results of their compilation are simulators of the behavior of control system.Conclusion. The proposed simulation method can be used to create a test bench for functional verification of the circuit implementation of control devices with behavior parallelism. In this case, test sequences for verifying the circuit implementation can be generated dynamically – in the process of simulating the description of the algorithm in the PRALU language directly the control device or system, which include the control algorithm and the algorithms of controlled objects behavior.

In today's world, renewable is the important source and in renewable energy plays vital role. Where wind turbines are placed in remote places and the operation and maintenance services (OMS) are plays key role to getting maximum availability and minimum breakdowns of wind turbine. To minimize the breakdowns in wind turbine, it is important to provide reliable and robust control system. Where communication between controllers plays key role in control system. In wind turbine, the frequency of occurrence of communication failed errors between rotating Hub and stationary Nacelle is causes of increase in breakdown in Wind Turbine. So, to implement W-CAN (Wireless Controller Area Network), where the CAN protocol gives reliable and robust communication between pitch controllers in HUB and Wireless Bluetooth over CAN protocol provide communication between Rotating hub and stationary nacelle which minimizes the communication failed errors. This system is implemented by using LPC1769, FreeRTOS, CAN (Controller Area Network), Bluetooth Protocol, LwIP (Light Weight Internet Protocol) Protocol and Motors. Today real-time communication is one of the key features in distributed embedded control systems. Using FreeRTOS, control system performance will be improved. FreeRTOS comprises CAN & LwIP protocol stack which transfer real time data from hub microcontroller node to nacelle microcontroller node. The Sensor acts as input source to this hub node and microcontroller nodes in compliance of FreeRTOS that includes the Real Time CAN driver which is used for secured and robust data transfer. Real-Time LwIP protocol stack is implemented on top of FreeRTOS to transfer the data to supervisory control and data acquisition (SCADA) System Application on Host PC. In this system, based on LwIP stack the data will be transferred from Turbine nacelle microcontroller Node to the PC Host SCADA application. SCADA application is used for data monitoring and controlling the operation. Hence with the help of this proposed system data acquisition and control of distributed embedded applications will be improved.

The work described in this paper relates to advanced control systems, specifically designed for heating, ventilation and air conditioning in office buildings. This work specifically focuses on the use of state of the art fan coil units with advanced instrumentation and control. The premise of the work is that control systems can be significantly enhanced by using real-time data from a distributed sensor network deployed in the building. Specifically, the performance of control systems can be improved by augmenting predictive (feed-forward) control operations with techniques to improve the accuracy of models. A control algorithm for heating, ventilating and air-conditioning systems is described in this paper that integrates an advanced feedforward control algorithm with conventional feedback control. This paper further contains a description of a functional prototype used to demonstrate the proposed control algorithm for indoor thermal environmental control. The test-bed used in this work — the Robert L Preger Intelligent Workplace (IW), at Carnegie Mellon University, involves a large number of variables and hence a complex control task, i.e., the test bed contains multiple sources of thermal energy, and multiple constraints and disturbances — both measurable and immeasurable. The algorithms demonstrated in this test-bed are expected to perform satisfactorily on other environments with smaller number of variables. This paper contains a description of experiments that were performed to validate the comfort and energy benefits of increased sensing using fan coil units that are in installed in two spaces in the IW.

Present study aimed to analysis whether delegation of authority and changes in control and management accounting systems, adjusts or increases the relationship between competition and corporate performance. Study Population is companies listed in Tehran Stock Exchange and needed data is gathered from questionnaire and financial statements. Excel software used to category information and for testing hypothesis statically software was used. Results show that there is a positive and meaningful relationship between competition power and management delegation of authority, change in control systems and management accounting system and corporate performance and changes in control and management accounting systems. Results also show that there is relationship between delegation of authority with variables like control and management accounting systems changes and corporate performance. Other results explain that there is meaningful relationship between changes in control and management accounting systems with corporate performance of management.

In the field of civil engineering, magnetorheological fluid (MRF) damper-based semi-active control systems have received considerable attention for use in protecting structures from natural hazards such as strong earthquakes and high winds. In this paper, the MRF damper-based semi-active control system is applied to a long-span spatially extended structure and its feasibility is discussed. Meanwhile, a trust-region method based instantaneous optimal semi-active control algorithm (TIOC) is proposed to improve the performance of the semi-active control system in a multiple damper situation. The proposed TIOC describes the control process as a bounded constraint optimization problem, in which an optimal semiactive control force vector is solved by the trust-region method in every control step to minimize the structural responses. A numerical example of a railway station roof structure installed with MRF-04K dampers is presented. First, a modified Bouc-Wen model is utilized to describe the behavior of the selected MRF-04K damper. Then, two semi-active control systems, including the well-known clipped-optimal controller and the proposed TIOC controller, are considered. Based on the characteristics of the long-span spatially extended structure, the performance of the control system is evaluated under uniform earthquake excitation and travelling-wave excitation with different apparent velocities. The simulation results indicate that the MR fluid damper-based semi-active control systems have the potential to mitigate the responses of full-scale long-span spatially extended structures under earthquake hazards. The superiority of the proposed TIOC controller is demonstrated by comparing its control effectiveness with the clipped-optimal controller for several different cases.

The task of model verification and control implementation for flexible multi-body systems undergoing large-angle displacement can probably be best accomplished using the experiments involved with large flexible multi-link manipulators. In this paper, various kinds of experiments for modeling and control for large flexible manipulators are reviewed. Although most experiments are restricted to either vertical or horizontal planes, and control algorithms are applied to simplified examples, insight gained in this survey will be useful to the advancement of the state-of-the-art for accurate modeling and precision control of flexible multibody manipulators.

The increased prevalence of semi-active control systems is largely due to the emergence of cost effective commercially available controllable damper technology such as Magneto-Rheological (MR) devices. Unfortunately, MR dampers are highly nonlinear, which presents an often over-looked complexity to the control system designer. The well-known Skyhook Damping control algorithm has enjoyed great success for both fully active and semi-active control problems. The Skyhook design strategy is to create a control force that emulates what a passive linear damper would create when connected to an inertial reference frame. Skyhook control is device independent since it generates a desired control force command output that must be produced by the control system. For simplicity, MR dampers are often assumed to have a linear relationship between the current input and the force output at a given relative velocity. Often this assumption is made implicitly and without knowledge of the underlying nonlinearity. In this paper, we show that the overall performance of a semi-active Skyhook control system can be improved by explicitly inverting the nonlinear relationship between input current and output force. The proposed modification will work with any semi-active control algorithm, such as Skyhook, to insure that the controller performance is at least as good as the performance without the proposed modification. This technique is demonstrated through simulation on a quarter-vehicle system.

Description While designing a subsea separator retention time and slug size are two important parameters that need to be considered. By using high speed control valves, the separator can be made smaller. A typical case will be discussed where the separator size could be reduced significantly (by approximately 50 to 90%) if high speed control valves and algorithms are used instead of a more conventional design. This consequently results in significant reduction in weight, size, cost of the separator. Also for deeper waters and higher design pressures, large separator vessels become increasingly difficult (or even impossible) to build, so this technique can be an enabling factor for deep / high pressure subsea separation system. This paper discusses 5 different control schemes that are considered to achieve the necessary control objectives of a subsea separator. All the control schemes discussed in this paper can handle process upsets, both liquid slugs and gas bursts. However, the ability to handle such transients varies depending on which control scheme is implemented. This paper also discusses two extreme cases and explains how well the 5 control schemes cope with them. This shows that the control loops can be configured in several ways with increasing performance and complexity. In general, performance is increased at the cost of complexity. Also there is a trade-off between separator size and control system performance: a better control system arrangement can reduce the size of the separator. Paper also touches upon the concept of subsea closed loop control system where SEM acts as a standalone processing unit which provides a fast response time. Application Subsea Separation, Boosting, Compression Results Results from FEED study performed for an operator located in GoM are discussed in this paper. The study showed a significant reduction in separator size (50% to 90%) and cost. It also improves the reliability and performance of the subsea separator control system. Significance Qualified subsea closed loop control system, fast acting valves has helped to implement subsea separation technology in North Sea fields. This experience can be extended to GoM and unlock the potential of the subsea processing and boosting equipments.