Discontinuous Projection-Based Adaptive Robust Control for Displacement-Controlled Actuators

2015 ◽  
Vol 137 (8) ◽  
Author(s):  
Enrique Busquets ◽  
Monika Ivantysynova
Keyword(s):  
Adaptive Controller ◽  
Adaptive Robust Control ◽  
Parametric Uncertainties ◽  
Tracking Accuracy ◽  
Hydraulic Motor ◽  
Fuel Savings ◽  
Performance Improvements ◽  
Wide Range ◽  
Asymptotic Tracking ◽  
Significant Performance

Displacement-controlled (DC) actuation is a revolutionary fluid power technology which has been utilized on a broad range of applications demonstrating substantial fuel savings and significant performance improvements over traditional valve-controlled (VC) systems. In this paper, a nonlinear discontinuous projection-based adaptive controller is synthesized to achieve precision motion control of DC actuators. The controller is formulated to compensate for uncertain parameters through online parameter adaptation. Additionally, its structure allows for the inclusion of unmodeled nonlinearities such as friction and external loads and disturbances. Transient performance and tracking accuracy are also guaranteed in the presence of both parametric uncertainties and uncertain nonlinearities, and asymptotic tracking is achieved in the presence of parametric uncertainties. To evaluate the synthesized controller, a test bench comprising a large hydraulically powered end-effector was utilized. The actuator, a vane-type hydraulic motor is mechanically connected to a large robotic arm with a wide range of motion. Measurement results demonstrate that the synthesized controller achieves the aforementioned advantages while attaining a high degree of motion accuracy.

Tracking Using an Inertial Measurement Unit (IMU) and GPS

2012 ◽  
Vol 229-231 ◽  
pp. 1469-1475 ◽  
Author(s):  
Hussein M. Magboub ◽  
Mohamed A. Msallem ◽  
Nasser Ali
Keyword(s):  
Inertial Measurement Unit ◽  
Simulation Software ◽  
Measurement Unit ◽  
Matlab Simulation ◽  
Tracking Accuracy ◽  
Inertial Measurement ◽  
Wide Range ◽  
Different Types ◽  
Significant Performance ◽  
Significant Attention

Since the last decade, vehicle tracking has been attracting significant attention in a wide range of applications. To deliver on their requirements, these applications need a specific tracking accuracy. However, current tracking techniques lack the required accuracy, especially for mission critical applications. Although these techniques have demonstrated significant performance improvement, there remain situations that give rise to degraded tracking accuracy, a deficiency that many applications cannot tolerate. This has motivated the research and development of advanced tracking. In this paper will be the design and implementation of an inertial navigation system (INS) using an inertial measurement unit (IMU) and GPS by Matlab simulation software. The INS is capable of providing continuous estimates of a vehicle’s position and orientation. And Comparative study of different types of estimation filters (KF, EKF) which has high accuracy is used to improve system state estimation.

ON THE PERFORMANCE AND TECHNOLOGICAL IMPACT OF ADDING MEMORY CONTROLLERS IN MULTI-CORE PROCESSORS

2010 ◽  
Vol 20 (04) ◽  
pp. 341-357 ◽  
Author(s):  
JOSE CARLOS SANCHO ◽  
DARREN J. KERBYSON ◽  
MICHAEL LANG
Keyword(s):  
State Of The Art ◽  
Current Trend ◽  
Application Performance ◽  
Memory Controller ◽  
Performance Improvements ◽  
Advantages And Disadvantages ◽  
Current State ◽  
Wide Range ◽  
Significant Performance ◽  
Technological Impact

The increasing core-count on current and future processors is posing critical challenges to the memory subsystem to efficiently handle concurrent memory requests. The current trend is to increase the number of memory channels available to the processor's memory controller. In this paper we investigate the advantages and disadvantages of this approach from both a technological and an application performance viewpoint. In particular, we explore the trade-off between employing multiple memory channels per memory controller and the use of multiple memory controllers with fewer memory channels. Experiments conducted on two current state-of-the-art multi-core processors, a 6-core AMD Istanbul and a 4-core Intel Nehalem-EP, using the STREAM benchmark and a wide range of production applications. An analytical model of the STREAM performance is used to illustrate the diminishing return obtained when increasing the number of memory channels per memory controller whose effect is also seen in the application performance. In addition, we show that this performance degradation can be efficiently addressed by increasing the ratio of memory controllers to channels while keeping the number of memory channels constant. Significant performance improvements can be achieved in this scheme, up to 28%, in the case of using two memory controllers each with one channel compared with one controller with two memory channels.

Adaptive Robust Control for Hydraulic Actuators With Disturbance Estimation

2015 ◽  
Author(s):  
Z. B. Xu ◽  
J. Y. Yao ◽  
Z. L. Dong ◽  
Y. Zheng
Keyword(s):  
Robust Control ◽  
Finite Time ◽  
Disturbance Observer ◽  
High Performance ◽  
Adaptive Robust Control ◽  
Parametric Uncertainties ◽  
Tracking Accuracy ◽  
Robust Controller ◽  
Hydraulic Actuators ◽  
Disturbance Estimation

In this paper, an adaptive robust control for hydraulic actuators with disturbance estimation is proposed for a hydraulic system with mismatched generalized uncertainties (e.g., parameter derivations, external disturbances, and/or unmodeled dynamics), in which a finite time disturbance observer and an adaptive robust controller are synthesized via backstepping method. The finite time disturbance observer is designed to estimate the mismatched generalized uncertainties. The adaptive robust controller is designed to handle parametric uncertainties and stabilize the closed loop system. The proposed controller accounts for not only the parametric uncertainties, but also the mismatched generalized uncertainties. Furthermore, the controller theoretically guarantees a prescribed tracking transient performance and final tracking accuracy while achieving asymptotic tracking performance after a finite time T0, which is very important for high accuracy tracking control of hydraulic servo systems. Simulation results are obtained to verify the high performance nature of the proposed control strategy.

scholarly journals Adaptive Control of a Class of Time-Delay Systems

2003 ◽  
Vol 125 (2) ◽  
pp. 186-193 ◽  
Author(s):  
S. Evesque ◽  
A. M. Annaswamy ◽  
S. Niculescu ◽  
A. P. Dowling
Keyword(s):  
Time Delay ◽  
Time Delays ◽  
Adaptive Controller ◽  
Delay Systems ◽  
Parametric Uncertainties ◽  
Simulation Studies ◽  
Adaptive Stabilization ◽  
Parameter Adaptation ◽  
Physical Systems ◽  
Asymptotic Tracking

The control of physical systems in the presence of time-delays becomes particularly challenging when parametric uncertainties are present. To cope with these ubiquitous uncertainties, we propose an adaptive controller in this paper that can accommodate both a time-delay and parametric uncertainties. The controller includes a) a control architecture that is based on the plant relative degree rather than the plant order, b) an integral implementation of the well known Posicast Controller so as to accommodate unstable plants, c) high-order tuners for parameter adaptation, and d) a Lyapunov-Krasvoskii functional that allows adaptive stabilization. The controller is shown to be semi-global in the time-delay τ and to result in asymptotic tracking. The implications of the adaptive controller are explored in the context of combustion control through simulation studies. Robustness properties of the controller are briefly discussed.

Energy-Efficient Adaptive Robust Control of Vector Thrust UAVs With Unknown Inertia Parameters

2018 ◽  
Author(s):  
Caiwu Ding ◽  
Lu Lu ◽  
Cong Wang
Keyword(s):  
Robust Control ◽  
Energy Efficient ◽  
Control Method ◽  
Thrust Force ◽  
Center Of Mass ◽  
Adaptive Robust Control ◽  
Parametric Uncertainties ◽  
Tracking Accuracy ◽  
Robust Tracking Control ◽  
Linear Equality Constraints

This paper proposes an energy-efficient adaptive robust tracking control method for a class of fully actuated, thrust vectoring unmanned aerial vehicles (UAVs) with parametric uncertainties including unknown moment of inertia, mass and center of mass, which would occur in aerial maneuvering and manipulation. We consider a novel vector thrust UAV with all propellers able to tilt about two perpendicular axes, so that the thrust force generated by each propeller is a fully controllable vector in 3D space, based on which an adaptive robust control is designed for accurate trajectory tracking in the presence of inertial parametric uncertainties and uncertain nonlinearities. Theoretically, the resulting controller achieves a guaranteed transient performance and final tracking accuracy in the presence of both parametric uncertainties and uncertain nonlinearities. In addition, in the presence of only parametric uncertainties, the controller achieves asymptotic output tracking. To resolve the redundancy in actuation, a thrust force optimization problem minimizing power consumption while achieving the desired body force wrench is formulated, and is shown to be convex with linear equality constraints. Simulation results are also presented to verify the proposed solution.

scholarly journals Performance Evaluation of Java Programming Strategies

2021 ◽  
Vol 10 (4) ◽  
pp. 146-159
Author(s):  
Qusay Idrees Sarhan
Keyword(s):  
Programming Languages ◽  
Web Applications ◽  
Experimental Studies ◽  
Experimental Tests ◽  
Performance Improvements ◽  
Java Programming ◽  
Software Applications ◽  
Wide Range ◽  
Significant Performance ◽  
The Impact

Java is one of the most demanding programming languages nowadays and it is used for developing a wide range of software applications including desktop, mobile, embedded, and web applications. Writing efficient Java codes for those various types of applications (which some are critical and time-sensitive) is crucial and recommended best practices that every Java developer should consider. To date, there is a lack of in-depth experimental studies in the literature that evaluate the impact of writing efficient Java programming strategies on the performance of desktop applications in terms of runtime. Thus, this paper aims to perform a variety of experimental tests that have been carefully chosen and implemented to evaluate the most important aspects of desktop efficient Java programming in terms of runtime. The results of this study show that significant performance improvements can be achieved by applying different programming strategies.

The Future of Plasma-Based Surface Engineering Techniques in Tribology (Keynote)

2005 ◽  
Author(s):  
Allan Matthews ◽  
Adrian Leyland
Keyword(s):  
Surface Engineering ◽  
Performance Enhancement ◽  
Bulk Material ◽  
Cost Savings ◽  
Cost Effective ◽  
Ceramic Coatings ◽  
Performance Improvements ◽  
Treatment Techniques ◽  
Wide Range ◽  
Macro Scale

Over the past twenty years or so, there have been major steps forward both in the understanding of tribological mechanisms and in the development of new coating and treatment techniques to better “engineer” surfaces to achieve reductions in wear and friction. Particularly in the coatings tribology field, improved techniques and theories which enable us to study and understand the mechanisms occurring at the “nano”, “micro” and “macro” scale have allowed considerable progress to be made in (for example) understanding contact mechanisms and the influence of “third bodies” [1–5]. Over the same period, we have seen the emergence of the discipline which we now call “Surface Engineering”, by which, ideally, a bulk material (the ‘substrate’) and a coating are combined in a way that provides a cost-effective performance enhancement of which neither would be capable without the presence of the other. It is probably fair to say that the emergence and recognition of Surface Engineering as a field in its own right has been driven largely by the availability of “plasma”-based coating and treatment processes, which can provide surface properties which were previously unachievable. In particular, plasma-assisted (PA) physical vapour deposition (PVD) techniques, allowing wear-resistant ceramic thin films such as titanium nitride (TiN) to be deposited on a wide range of industrial tooling, gave a step-change in industrial productivity and manufactured product quality, and caught the attention of engineers due to the remarkable cost savings and performance improvements obtained. Subsequently, so-called 2nd- and 3rd-generation ceramic coatings (with multilayered or nanocomposite structures) have recently been developed [6–9], to further extend tool performance — the objective typically being to increase coating hardness further, or extend hardness capabilities to higher temperatures.

scholarly journals An Attention-Based Multilayer GRU Model for Multistep-Ahead Short-Term Load Forecasting

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1639
Author(s):  
Seungmin Jung ◽  
Jihoon Moon ◽  
Sungwoo Park ◽  
Eenjun Hwang
Keyword(s):  
Power Consumption ◽  
Prediction Models ◽  
Short Term Memory ◽  
Load Forecasting ◽  
Input Sequence ◽  
Short Term ◽  
Performance Improvements ◽  
Short Term Load Forecasting ◽  
Significant Performance ◽  
Input Variables

Recently, multistep-ahead prediction has attracted much attention in electric load forecasting because it can deal with sudden changes in power consumption caused by various events such as fire and heat wave for a day from the present time. On the other hand, recurrent neural networks (RNNs), including long short-term memory and gated recurrent unit (GRU) networks, can reflect the previous point well to predict the current point. Due to this property, they have been widely used for multistep-ahead prediction. The GRU model is simple and easy to implement; however, its prediction performance is limited because it considers all input variables equally. In this paper, we propose a short-term load forecasting model using an attention based GRU to focus more on the crucial variables and demonstrate that this can achieve significant performance improvements, especially when the input sequence of RNN is long. Through extensive experiments, we show that the proposed model outperforms other recent multistep-ahead prediction models in the building-level power consumption forecasting.

scholarly journals Data Downlink System in the Vast IOT Node Condition Assisted by UAV, Large Intelligent Surface, and Power and Data Beacon

Sensors ◽  
2020 ◽  
Vol 20 (20) ◽  
pp. 5748
Author(s):  
Zhibo Zhang ◽  
Qing Chang ◽  
Na Zhao ◽  
Chen Li ◽  
Tianrun Li
Keyword(s):  
Communication Systems ◽  
Optimization Problems ◽  
Minimum Energy ◽  
Numerical Algorithms ◽  
Flight Trajectory ◽  
Performance Improvements ◽  
Minimum Energy Consumption ◽  
Significant Performance ◽  
Downlink System ◽  
The Internet Of Things

The future development of communication systems will create a great demand for the internet of things (IOT), where the overall control of all IOT nodes will become an important problem. Considering the essential issues of miniaturization and energy conservation, in this study, a new data downlink system is designed in which all IOT nodes harvest energy first and then receive data. To avoid the unsolvable problem of pre-locating all positions of vast IOT nodes, a device called the power and data beacon (PDB) is proposed. This acts as a relay station for energy and data. In addition, we model future scenes in which a communication system is assisted by unmanned aerial vehicles (UAVs), large intelligent surfaces (LISs), and PDBs. In this paper, we propose and solve the problem of determining the optimal flight trajectory to reach the minimum energy consumption or minimum time consumption. Four future feasible scenes are analyzed and then the optimization problems are solved based on numerical algorithms. Simulation results show that there are significant performance improvements in energy/time with the deployment of LISs and reasonable UAV trajectory planning.

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