Control Point Of View Research Articles

Improve Performance or Corruption Motivation in Beyond Budget Implementation, Survey in Public Sector Organizations

This paper aims to determine possibility beyond budget implementation in public sector organization which submissive to federal government budget instructions, this budget as an act should be followed, by those organizations committed by financial ministry planning. We have discussed tow thinking groups. First, a group that performs the use of the budget as a tool for financial control, they criticize the use of beyond budget, (Horngren et al., 2004). second, group ague adoption of the budget in the control is method has become useless, beyond budget provide better utilization resource and best regarding with market opportunities and problems (Hope and Fraser, 2003), (Hansen et al., 2003). We interviewed accounting managers, auditing managers, and their assistance in research sample organizations which owned by government. Interviews were conducted from a managerial viewpoint with the accounting managers and their assistants, as well as from a control viewpoint with auditing managers, in order to distinguish between areas of corruption and financial performance motivation. Interview has done in December 2020 to February 2021, in public sector organization in Al-Najaf city in Iraq. We found public sector organization possible to implement beyond budget. However research sample organizations need to improve their level of controlling and efficiency for employees otherwise ignore traditional budgets, will cause corruption and authority misusing. Implementation beyond budgeting helps them to provide solutions the problems facing activities which unexpected. Keywords: beyond budgeting, performance improving, reduce corruption, controlling DOI: 10.7176/RJFA/12-6-04 Publication date: March 31 st 2021

Integration of feedback control and run-to-run control for plasma enhanced atomic layer deposition of hafnium oxide thin films

Facilitated by the increasing importance and demand of semiconductors for the smartphone and even the automobile industry, the plasma-enhanced atomic layer deposition (PEALD) has gained tremendous industrial interest as it offers a way to efficiently deposit thin-films with ultra-high conformity. A series of studies have been carried out to elucidate the mechanisms and the concept of the PEALD process. Despite the great deal of research effort, PEALD processes have not been fully characterized from the view point of process control. This study aims to use a previously developed multiscale computational fluid dynamics (CFD) simulation model to design and evaluate an optimized control scheme to deal with industrially-relevant disturbances. Specifically, an integrated control scheme using a proportional-integral (PI) controller and a run-to-run (R2R) controller is proposed and evaluated to ensure the deposition of high-quality conformal thin-films. The PEALD process under typical disturbances is simulated using the multiscale CFD model, and the integrated controller is applied in the process domain. Using the controller parameters determined from the open-loop results, the developed integrated PI-R2R controller successfully mitigates the disturbances in the operating pressure and the gas bubbler temperature with the combined effort of both controllers.

Advanced control of the cooling system in IC vehicles

The cooling system of internal combustion (IC), electric or fuel cell vehicles is crucial. Not only that it avoids hazards and vehicle fails but it additionally provides the optimal operating temperature improving the reliability of the vehicle and reduced fuel consumption. The great nonlinearities, variable time constants and time delays present in the cooling system’s model offers challenges from a control point of view. This paper provides a control strategy approach that can keep the optimal temperature regardless of the disturbances in the system and uses three control loops for the engine temperature, the temperature difference between engine inflow and outflow, and the temperature of the radiator outflow. The classical mechanical pump and thermostatic valve were replaced with their electrically actuated equivalent for better controllability. The control strategy was tested using realistic driving conditions provided by the New European Driving Cycle (NEDC).

Ground effect on rotorcraft unmanned aerial vehicles: a review

This article aims at collecting and discussing the results reached by the research community regarding the study of the ground effect on small rotorcraft unmanned aerial vehicles, especially from the modeling and control point of view. Rotorcraft performance is affected by the presence of the ground or any other boundary that alters the flow into the rotors. Specifically, the ground effect can induce perturbations in the flight stability, when operating near the ground. For a rotorcraft, an accident is likely to happen when the vehicle leaves or enters the ground effect region, which may cause crashes and property damages. Today, the use of unmanned aerial vehicles has grown widespread, which raises safety concerns when they are flying at very low altitudes and near the ground. Consequently, studying the influence of the ground over rotorcrafts is of paramount importance for general safety. Also, these investigations can be used to design systems of guidance, navigation, and control. In this review, we break down the most relevant works to date. We discuss aspects related to modeling, control, and application of the ground effect for small-scale multirotors, as well as other aerodynamic proximity effects, such as the ceiling and wall effects. We conclude by mentioning potential avenues of research when studying the ground effect from the point of view of the robotics and artificial intelligence fields.

Robust observer-based tracking control under actuator constraints for power-assisted wheelchairs

Power-assisted wheelchairs (PWA) is an important growing market. The goal is to provide electrical assistive kits that are able to cope with a large family of disabled people and to equip a large variety of wheelchairs. This work is made in collaboration with Autonomad Mobility, a company that designs the hardware and sells Power-Assistance kits for wheelchairs. Several crucial issues arise, e.g. how to assist any Person with Reduced Mobility (PRM)? How to detect user’s intentions? how to cope with the lack of system information due to excessive sensor costs. Effectively, due to the variety of wheelchairs and the different unknown PRM characteristics (mass, height, force, etc.) and pathologies, it is unrealistic to provide a solution using a precise modeling of the whole system including the wheelchair, the PRM and the ground conditions. However, proposing a safe and secure solution is obviously mandatory for this application. In particular, an on-the-market solution should be also smooth and friendly for the end-user. Estimation of the human torques is a first key point to achieve such a solution, which has been already studied in our previous works. This paper exploits these estimation results to propose a robust control law for PWA systems under saturation constraints. These constraints are unavoidable due to regulations on maximum authorized speed. From a control point of view, it resumes to an output feedback control with partially unknown references (desired speed, direction), unknown parameters (wheelchair and PRM masses, available force, ground characteristics) and input constraints. Finding an effective solution for this constrained output feedback tracking control still remains open. In this paper, we propose a two-step control design using quasi Linear Parameter Varying (q-LPV) formulation to solve this challenging control problem, i.e., first design an observer for state and unknown input estimation, and second propose a robust control scheme under parameter variations and input saturations. The control procedure is reformulated as convex optimization problems involving linear matrix inequality (LMI) constraints that can be efficiently solved with standard numerical solvers. Simulations and real-time experiments are proposed to show the effectiveness of the solution.

Contribution of N,N-dimethylformamide to formation of N-nitrosodimethylamine by chloramination in sewage treatment plants and receiving rivers

The contribution of specific precursors to N-nitrosodimethylamine formation potential (NDMA FP) upon chloramination depends not only on their NDMA molar yields but also on their concentrations in the actual environment. We investigated the seasonal and diurnal patterns of the NDMA precursor N,N-dimethylformamide (DMF) and NDMA FP in the Yodo River basin, Japan, by examining water samples taken from inside the basin's largest sewage treatment plant (STP) as well as samples from five final effluents from four STPs, two main stream sites, and two tributary sites in the same basin. DMF and NDMA FP were found to be high in influent (raw sewage), and were found to be mostly removed during the STP treatment processes (especially with biological treatment). Nevertheless, DMF was found in concentrations of 0.06 to 31.7 µg/L in chlorinated effluents and in receiving rivers, while NDMA FP was detected in concentrations of 3.57 to 306 ng/L. Thus, STPs were shown to be an important source of DMF and NDMA FP to rivers. A strong positive correlation between NDMA FP and DMF was confirmed in the receiving river (K-M), indicating that DMF was an important NDMA precursor in the Yodo River basin. The contribution of DMF to NDMA FP was 15.8±11.2% (n = 4) in summer and 82.1±10.2% (n = 4) in winter in the main stream (site K-M) of the river due to insufficient dilution of chlorinated effluents from the largest STP. From the viewpoint of NDMA and NDMA FP control at downstream sites, monitoring and control of DMF at upstream sites are important.

A Hybrid H∞ Control Based ILC Design Approach for Trajectory Tracking of a Twin Rotor Aerodynamic System

This paper investigates the trajectory tracking problem for a Multi-Input Multi-Output (MIMO) Twin Rotor Aerodynamic System (TRAS) using a hybrid architecture based on an H∞∞∞∞ controller and Iterative Learning Control (ILC). TRAS is a fast, nonlinear coupled system and therefore it is a challenging task to design a control system that ensures the tracking for fast changing trajectories. The controllers proposed in the literature for the TRAS through linear approaches tend to have a large control effort, while the ones designed using the nonlinear approaches track only for smooth input trajectories. Both issues are important from control point of view. In this paper, these issues are addressed by designing a feedback H∞∞∞∞ control that stabilizes the system and a feedforward ILC which reduces the control effort. The H∞∞∞∞ controller achieves the tracking for input trajectories with sharp edges, but the control effort required for tracking is large. With the proposed hybrid approach, tracking is achieved by the H∞∞∞∞ controller whereas the required control effort is reduced in each subsequent iteration by ILC. After a few iterations, accurate tracking at a minimized control effort is achieved. The simulations have been performed using MATLAB software and the controller designed through the proposed approach has been validated on nonlinear model of the system. The results of the proposed technique, compared with the flatness-based and back-stepping control strategies, show that the proposed controller ensures accurate tracking at the reduced control effort.

A Novel Local and Global Cooperative Approach for Distributed Mobile Cloud Computing

In the cloud service paradigm, service providers aim to cost-efficiently serve Internet of Things (IoT) devices’ applications that often request computation-intensive services. In this study, we focus on the cloud resource sharing problem in the distributed mobile cloud computing (DMCC) platform. By considering different IoT applications and distributed cloud infrastructure, we design a novel DMCC resource sharing scheme for data offloading services. Based on the cooperative game theory, five different value solutions are adopted, and they are implemented for each case cooperative process to provide the fair-efficient solution. According to the service characteristics, our proposed scheme explores the mutual benefits of local and global MCC providers’ interactions, and effectively shares the distributed cloud resources. To dynamically adapt the current DMCC system conditions, our approach can provide an appropriate guidance to improve the efficiency of cloud resource usage while enhancing the service quality. The main novelty of our proposed scheme is the ability to leverage a reciprocal consensus between different control viewpoints. Therefore, we can ensure a relevant tradeoff between efficiency and fairness among multiple service providers.

Gaps in the Control of Automated Vehicles on Roads

Increased on-road testing and market availability of partially automated vehicles (AV) offers researchers and developers the opportunity to evaluate the AV’s performance. The occurrence of new types of accidents involving AV’s has sparked questions in regard to who is actually in control over and responsible for AV control. In this contribution, we suggest a potential discrepancy in AV control with the review of recently documented accidents involving AV’s. The identification of a gap in control is performed using a recently formulated moral philosophical framework of Meaningful Human Control (MHC). This shows a discrepancy between the attribution of responsibility and the ability of a human to fulfil the role assigned to them. While a gap in control is not evident from the viewpoint of operational control, it requires the more intricate concept of MHC to expose it. Recommendations are further made that AV developers and vehicle approval authorities should consider control from a MHC perspective to avoid future gaps in control with the resulting consequences.

An Activity Theory Approach to Leak Detection and Mitigation in Patient Health Information (PHI)

The migration to electronic health records (EHR) in the healthcare industry has raised issues with respect to security and privacy. One issue that has become a concern for healthcare providers, insurance companies, and pharmacies is patient health information (PHI) leaks because PHI leaks can lead to violation of privacy laws, which protect the privacy of individuals’ identifiable health information, potentially resulting in a healthcare crisis. This study explores the issue of PHI leaks from an access control viewpoint. We utilize access control policies and PHI leak scenarios derived from semi structured interviews with four healthcare practitioners and use the lens of activity theory to articulate the design of an access control model for detecting and mitigating PHI leaks. Subsequently, we follow up with a prototype as a proof of concept.

Line-Independent Plug-and-Play Voltage Stabilization and ℒ₂ Gain Performance of DC Microgrids

The plug-and-play nature of distributed generation (DG) units in converter-interfaced microgrids imposes significant challenges from the control point of view, mainly caused by the time-varying microgrid structure. In this letter, we propose a systematic plug-and-play decentralized voltage control solution for DC microgrids. The proposed control approach guarantees the stable operation and satisfactory performance of microgrids under the arbitrary interconnection of DG units. Based on the Lyapunov method, concise stability and ℒ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> gain voltage tracking performance certificates for DC microgrids are derived. The main feature of the proposed control approach is the decentralized design of local voltage controllers in DC microgrods. The proposed voltage control framework is applied to a case study of a multiple-DG DC microgrid in MATLAB/Simscape Electrical environment.

Small Hydropower Plants with Variable Speed Operation—An Optimal Operation Curve Determination

In recent times, much attention has been paid to small hydropower plants (SHPs) with variable speed operation and different control techniques. Control complexity in SHPs is mainly caused by specific steady-state features of the water turbine, the long time constants of the hydraulic system and significant seasonal and/or aging-related deterioration in the system performance. This paper presents the most important features of the turbine model from a control point of view. It classifies control techniques for SHPs with variable speed operation in terms of the turbine type and SHP function (run-of-the-river and reservoir). Furthermore, various control methods are analysed taking into account the complexity of the method, dynamics, adaptability and applicability. The novelty of this study is the proposal of a simple, universal analytical formula, which, based on the basic dimensions of the turbine, determines the optimal operating curve. The proposed formula is verified on a real SHP 150 kW by comparison with measurements in the form of operational characteristics. The analysis of the annual energy production confirms the effectiveness of the approximation precision, yielding only 1% production losses, and shows an advantage of variable speed over constant speed in annual energy production of 16%.

Lateral Control of an Autonomous and Connected Following Vehicle With Limited Preview Information

Lateral control of an autonomous and connected vehicle (ACV), especially in emergency situations, is important from the safety viewpoint. In these situations, the trajectory to be followed by an ACV must either be planned in real-time (e.g., for a possible evasion maneuver if the obstacle to be avoided is detected) or be communicated from its preceding vehicle. Typically, the trajectory information is available to the following ACV in the form of GPS time samples. From the viewpoint of lateral control, the lateral velocity information is not readily available and the feedback structure must reflect this reality. In this paper, we develop a methodology to synthesize a lateral control algorithm for a following ACV in a two-vehicle platoon in two steps: 1) From the limited preview information of the trajectory to be tracked via samples of GPS way points, we estimate the radius of curvature of the trajectory using “least-square” estimation and 2) develop a fixed-structure feedback control scheme for following the predecessor by synthesizing the set of stabilizing gains corresponding to lateral position error, heading error and heading rate error. Numerical simulation and experimental results corroborate the effectiveness of the proposed schemes.

Topology Optimization of High-Speed Flexible Robot Arms. (Dept. M.)

There are growing demands in the robot industry for light structures in order to increase the speed of the robot motion and thus the productivity. Size and shape optimization are carried out previously to achieve minimum traveling time of the robot arm taking into consideration its flexibility. In this work, topology optimization is introduced for obtaining optimum robot arm to achieve minimum traveling time from both structure and control viewpoints. Method of Moving Asymptotes is used as optimization technique, because it can handle arbitrary number of constrains and considered to be a general and flexible optimization method. A comparison is accomplished between the optimal resulted design and its initial design for different dimensions of robot arm neglecting air damping. It is found that the reduction ratio of the travelling time reaches 62% and the reduction ratio of the weight reaches 70%. A comparison between this work using topology optimization of flexible robot arm outperforms the size and the shape optimization when considering the real condition that takes into account the air damping. The optimum topological design in this case gives reduction ratio of travelling time equals 44.8%, while previous work gives 23.5%.

Globally convergent leaderless formation control for unicycle‐type mobile robots

This study investigates the leaderless formation control problem for unicycle-type mobile robots and designs a formation controller for a two-robot system. The proposed control law is globally effective, namely making mobile robots converge to the formation from all kinds of initial conditions. The kinematic model of mobile robots is directly established on the special Euclidean group, and the mobile robot is merely required to obtain the relative configuration (i.e. position and orientation) in its own body-fixed frame. The approach for the formation problem is to design a virtual system for each mobile robot, which contains the desired formation pattern, so that the formation problem for mobile robots is converted into the consensus problem for virtual systems. Furthermore, the non-holonomic constraint for the virtual systems is derived for the first time, which is explained from the viewpoint of geometric control. In addition, the authors clarify the physical meaning of the multiple control gains, which can guarantee excellent robot behaviour by appropriate selection.

Can the mammalian organoid technology be applied to the insect gut?

Mammalian intestinal organoids are multicellular structures that closely resemble the structure of the intestinal epithelium and can be generated in vitro from intestinal stem cells under appropriate culture conditions. This technology has transformed pharmaceutical research and drug development in human medicine. For the insect gut, no biotechnological platform equivalent to organoid cultures has been described yet. Comparison of the regulation of intestinal homeostasis and growth between insects and mammals has revealed significant similarities but also important differences. In contrast to mammals, the differentiation potential of available insect cell lines is limited and can not be exploited for in vitro permeability assays to measure the uptake of insecticides. The successful development of in vitro models could be a result of the emergence of molecular mechanisms of self-organization and signaling in the intestine that are unique to mammals. It is nevertheless considered that the technology gap is a consequence of vast differences in knowledge, particularly with respect to culture conditions that maintain the differentation potential of insect midgut cells. From the viewpoint of pest control, advanced in vitro models of the insect midgut would be very desirable because of its key barrier function for orally ingested insecticides with hemolymphatic target and its role in insecticide resistance. © 2020 Society of Chemical Industry.

Control Architecture for Human-Like Motion With Applications to Articulated Soft Robots.

Human beings can achieve a high level of motor performance that is still unmatched in robotic systems. These capabilities can be ascribed to two main enabling factors: (i) the physical proprieties of human musculoskeletal system, and (ii) the effectiveness of the control operated by the central nervous system. Regarding point (i), the introduction of compliant elements in the robotic structure can be regarded as an attempt to bridge the gap between the animal body and the robot one. Soft articulated robots aim at replicating the musculoskeletal characteristics of vertebrates. Yet, substantial advancements are still needed under a control point of view, to fully exploit the new possibilities provided by soft robotic bodies. This paper introduces a control framework that ensures natural movements in articulated soft robots, implementing specific functionalities of the human central nervous system, i.e., learning by repetition, after-effect on known and unknown trajectories, anticipatory behavior, its reactive re-planning, and state covariation in precise task execution. The control architecture we propose has a hierarchical structure composed of two levels. The low level deals with dynamic inversion and focuses on trajectory tracking problems. The high level manages the degree of freedom redundancy, and it allows to control the system through a reduced set of variables. The building blocks of this novel control architecture are well-rooted in the control theory, which can furnish an established vocabulary to describe the functional mechanisms underlying the motor control system. The proposed control architecture is validated through simulations and experiments on a bio-mimetic articulated soft robot.

Learning Adaptive Regularization for Image Labeling Using Geometric Assignment

We study the inverse problem of model parameter learning for pixelwise image labeling, using the linear assignment flow and training data with ground truth. This is accomplished by a Riemannian gradient flow on the manifold of parameters that determines the regularization properties of the assignment flow. Using the symplectic partitioned Runge–Kutta method for numerical integration, it is shown that deriving the sensitivity conditions of the parameter learning problem and its discretization commute. A convenient property of our approach is that learning is based on exact inference. Carefully designed experiments demonstrate the performance of our approach, the expressiveness of the mathematical model as well as its limitations, from the viewpoint of statistical learning and optimal control.

An Object-Oriented Systems Engineering Point of View to Develop Controllers of Quadrotor Unmanned Aerial Vehicles

The aerospace industry needs to be provided with system solutions to technologically challenging and mission-critical problems. Based on the industrial control point of view, development engineers must take costs and existing standards into account in order to effectively design, implement, and deploy control systems with reasonable costs. The customization and reusability are important factors associated with the production of new applications in order to reduce their costs, resources, and development time. In this work, the Model-Driven Architecture (MDA)/Model-Based Systems Engineering (MBSE) approach combined with the real-time Unified Modeling Language (UML)/Systems Modeling Language (SysML), Unscented Kalman Filter (UKF) algorithm, and hybrid automata is specialized to obtain a hybrid control model in order to conveniently deploy controllers of Quadrotor Unmanned Aerial Vehicles (Q-UAVs). This hybrid control model also provides a real-time capsule pattern, which allows the designed elements to be customizable and reusable in new applications of various multirotor UAVs of the Vertical Take-Off and Landing (VTOL) type. The Q-UAV dynamics and control architecture are combined with the MDA/MBSE specialization as follows: the Computation Independent Model (CIM) is defined by specifying the use-case model together with the UKF algorithm and hybrid automata to intensively gather the control requirements. The Platform Independent Model (PIM) is then designed by specializing the real-time UML/SysML’s features to obtain the main control capsules, ports, and protocols, together with their dynamic evolution. The detailed PIM is subsequently transformed into the PSM by open-source platforms to rapidly implement and deploy the Q-UAV controller. The paper ends with trial flights and deployment results that show good feasibility to be used for a trajectory-tracking controller of a low-cost Q-UAV. In this case study, the Q-UAV controller is implemented with the simulation model in the OpenModelica tool. The obtained simulation results then allow the main control elements and their properties to be defined, as well as building the implementation libraries in the Arduino environment based on C++ language to quickly perform the realization model in the ATMEGA32-U2 and STM32 Cortex-M4 microcontrollers.

Review of Harmonic Mitigation Methods in Microgrid: From a Hierarchical Control Perspective

The microgrid concept has been emerged into the power system to provide reliable, renewable, and cheaper electricity for the rising global demand. When the microgrids are introduced, there will be several concerns, such as active and reactive powers' sharing, load management, connecting to the main grid, and voltage and current deviations. Recently, with the fast deployment of distributed generation, methods to mitigate microgrid harmonics caused by nonlinear loads and power electronic devices have become one of the main focus areas. Consequently, many research works are devoted to this area, introducing different harmonic mitigation methods suitable for the microgrids. Hence, the main goal of this article is to clearly present a comprehensive review of harmonic mitigation methods from a hierarchical control viewpoint. The control strategies proposed to mitigate harmonics are classified into three groups: primary, secondary, and tertiary. Furthermore, this overview draws a sketch on the global trends in harmonic mitigation methods of an ac microgrid directly applicable to today's smart grid applications.