Nonlinear Compensation for High Performance Feedback Systems With Actuator Imperfections

2013 ◽  
Author(s):  
Cameron L. Mock ◽  
Zachary T. Hamilton ◽  
Dustin Carruthers ◽  
John F. O’Brien
Keyword(s):  
Performance Feedback ◽  
High Performance ◽  
Vibration Suppression ◽  
Actuator Saturation ◽  
Design Method ◽  
Nonlinear Feedback ◽  
Feedback Systems ◽  
Performance Requirements ◽  
Common Causes ◽  
And Performance

Measures to reduce control performance for greater robustness (e.g. reduced bandwidth, shallow loop roll-off) must be enhanced if the plant or actuators are known to have nonlinear characteristics that cause variations in loop transmission. Common causes of these nonlinear behaviors are actuator saturation and friction/stiction in the moving parts of mechanical systems. Systems with these characteristics that also have stringent closed loop performance requirements present the control designer with an extremely challenging problem. A design method for these systems is presented that combines very aggressive Nyquist-stable linear control to provide large negative feedback with nonlinear feedback to compensate for the effects of multiple nonlinearities in the loop that threaten stability and performance. The efficacy of this approach is experimentally verified on a parallel kinematic mechanism with multiple uncertain nonlinearities used for vibration suppression.

A New QFT Design Methodology for Feedback Systems Under Input Saturation

1999 ◽  
Vol 123 (2) ◽  
pp. 225-232 ◽  
Author(s):  
Wei Wu ◽  
Suhada Jayasuriya
Keyword(s):  
Robust Stability ◽  
Design Methodology ◽  
Design Method ◽  
Input Saturation ◽  
Function Technique ◽  
Feedback Systems ◽  
Robust Performance ◽  
Saturation Nonlinearity ◽  
Performance Requirements ◽  
And Performance

Presented in this paper is a design methodology for robust stability and robust performance for a large class of plants subject to an input saturation nonlinearity. Based on Horowitz’s 3-DOF linear design method, a more general form for the additional loop transmission around the saturating element is proposed to design the third degree of freedom Hs, for Type n plants, n⩾1. Robust stability is established with the circle criterion and the describing function technique, and robust performance is improved by imposing nonovershooting conditions. All stability and performance requirements are then transferred into frequency domain design bounds which are easily obtained using QFT design techniques. This procedure applies to all SISO, Type n, stable plants with uncertainties (parametric or nonparametric), and to marginally stable and conditionally stable plants as well.

scholarly journals The role of performance feedback consistency in aspiration level adaptation: Evidence from a European grocery retailer

2019 ◽  
Vol 45 (1) ◽  
pp. 18-29
Author(s):  
Burak Cem Konduk
Keyword(s):  
Performance Feedback ◽  
High Performance ◽  
Past Research ◽  
Aspiration Level ◽  
Performance Targets ◽  
Aspiration Levels ◽  
Organizational Attention ◽  
And Performance ◽  
The Impact

This study investigates whether and how the impact of drivers of aspiration levels changes across the cases of consistent and inconsistent performance feedback within the context of a retailer. Analysis of internal corporate data shows that while past aspiration level and performance–aspiration gap positively influence the current aspiration level in the case of inconsistent feedback, performance feedback consistency changes only the impact of performance relative to peers. This study replicates past research in a different industry and country due to limited empirical evidence, introduces real-world complexity into aspiration theory, pinpoints performance–aspiration gap as the primary performance feedback, introduces a new sign for the impact of performance relative to peers, and reconciles its previously detected mixed impact. The findings suggest that organizational attention has an inward focus in the case of inconsistent feedback. The results also point out that leaders can trigger change through a performance outcome that lags behind the corresponding aspiration level rather than the performance of peers and eventually move their organizations toward high performance targets by starting with feasible rather than stretch goals.

Anti-Windup LPV Control of Magneto-Rheological Dampers

2009 ◽  
Author(s):  
Mona Meisami-Azad ◽  
Javad Mohammadpour ◽  
Karolos M. Grigoriadis
Keyword(s):  
Actuator Saturation ◽  
Design Method ◽  
External Disturbance ◽  
Control Design ◽  
Operating Parameter ◽  
Mr Damper ◽  
Saturation Parameter ◽  
The Status ◽  
And Performance ◽  
Magneto Rheological

In this paper, we develop a linear parameter varying (LPV) model for the structural systems including the Magneto-Rheological (MR) dampers where the LPV parameter is the MR damper velocity. We then propose an LPV anti-windup control design method to prevent the closed-loop system instability and performance degradation due to the MR damper actuator saturation. The proposed control design method accounts for the actuator nonlinearities by representing the status of the saturated actuator as an additional gain-scheduled varying parameter. The resulting controller is scheduled with respect to the system operating parameter and the actuator saturation parameter. Simulation results demonstrate that the anti-windup compensator scheduled based on the MR damper velocity and the saturation parameter is able to keep the voltage within the specified limits and meets the design requirement of rejecting the effect of the external disturbance signals.

scholarly journals Design of a Clutchless Hybrid Transmission for a High-Performance Vehicle

2015 ◽  
Author(s):  
Chad L. Jacoby ◽  
Young Suk Jo ◽  
Jake Jurewicz ◽  
Guillermo Pamanes ◽  
Joshua E. Siegel ◽  
...  
Keyword(s):  
High Performance ◽  
Power Flow ◽  
Combustion Engine ◽  
Performance Requirements ◽  
Wide Range ◽  
Friction Clutch ◽  
Hybrid Transmission ◽  
And Performance ◽  
Electrical Motors ◽  
Operational Modes

There exists the potential for major simplifications to current hybrid transmission architectures, which can lead to advances in powertrain performance. This paper assesses the technical merits of various hybrid powertrains in the context of high-performance vehicles and introduces a new transmission concept targeted at high performance hybrid applications. While many hybrid transmission configurations have been developed and implemented in mainstream and even luxury vehicles, ultra high performance sports cars have only recently begun to hybridize. The unique performance requirements of such vehicles place novel constraints on their transmissions designs. The goals become less about improved efficiency and smoothness and more centered on weight reduction, complexity reduction, and performance improvement. To identify the most critical aspects of a high performance transmission, a wide range of existing technologies is studied in concert with basic physical performance analysis of electrical motors and an internal combustion engine. The new transmission concepts presented here emphasize a reduction in inertial, frictional, and mechanical losses. A series of conceptual powertrain designs are evaluated against the goals of reducing mechanical complexity and maintaining functionality. The major innovation in these concepts is the elimination of a friction clutch to engage and disengage gears. Instead, the design proposes that the inclusion of a large electric motor enables the gears to be speed-matched and torque-zeroed without the inherent losses associated with a friction clutch. Additionally, these transmission concepts explore the merits of multiple electric motors and their placement as well as the reduction in synchronization interfaces. Ultimately, two strategies for speed-matched gear sets are considered, and a speed-matching prototype of the chosen methodology is presented to validate the feasibility of the proposed concept. The power flow and operational modes of both transmission architectures are studied to ensure required functionality and identify further areas of optimization. While there are still many unanswered questions about this concept, this paper introduces the base analysis and proof of concept for a technology that has great potential to advance hybrid vehicles at all levels.

scholarly journals Preparation and performance of the ultra-high performance mortar based on simplex-centroid design method

2021 ◽  
Author(s):  
Ying Chen ◽  
Peng Liu ◽  
Fei Sha ◽  
Sasa He ◽  
Guangfeng Lu ◽  
...  
Keyword(s):  
High Performance ◽  
Design Method ◽  
And Performance

FLASH: F ast Neura l A rchitecture S earch with H ardware Optimization

2021 ◽  
Vol 20 (5s) ◽  
pp. 1-26
Author(s):  
Guihong Li ◽  
Sumit K. Mandal ◽  
Umit Y. Ogras ◽  
Radu Marculescu
Keyword(s):  
Energy Consumption ◽  
High Performance ◽  
Search Space ◽  
Analytical Models ◽  
Raspberry Pi ◽  
Simplicial Homology ◽  
Theoretical Contribution ◽  
Standard Ml ◽  
Performance Requirements ◽  
And Performance

Neural architecture search (NAS) is a promising technique to design efficient and high-performance deep neural networks (DNNs). As the performance requirements of ML applications grow continuously, the hardware accelerators start playing a central role in DNN design. This trend makes NAS even more complicated and time-consuming for most real applications. This paper proposes FLASH, a very fast NAS methodology that co-optimizes the DNN accuracy and performance on a real hardware platform. As the main theoretical contribution, we first propose the NN-Degree, an analytical metric to quantify the topological characteristics of DNNs with skip connections (e.g., DenseNets, ResNets, Wide-ResNets, and MobileNets). The newly proposed NN-Degree allows us to do training-free NAS within one second and build an accuracy predictor by training as few as 25 samples out of a vast search space with more than 63 billion configurations. Second, by performing inference on the target hardware, we fine-tune and validate our analytical models to estimate the latency, area, and energy consumption of various DNN architectures while executing standard ML datasets. Third, we construct a hierarchical algorithm based on simplicial homology global optimization (SHGO) to optimize the model-architecture co-design process, while considering the area, latency, and energy consumption of the target hardware. We demonstrate that, compared to the state-of-the-art NAS approaches, our proposed hierarchical SHGO-based algorithm enables more than four orders of magnitude speedup (specifically, the execution time of the proposed algorithm is about 0.1 seconds). Finally, our experimental evaluations show that FLASH is easily transferable to different hardware architectures, thus enabling us to do NAS on a Raspberry Pi-3B processor in less than 3 seconds.

An Improved Size, Matching, and Scaling Method for the Design of Deterministic Mesoscale Truss Structures

2011 ◽  
Author(s):  
Patrick S. Chang ◽  
David W. Rosen
Keyword(s):  
High Performance ◽  
Design Method ◽  
Weight Ratio ◽  
High Strength ◽  
Original Method ◽  
Topological Optimization ◽  
Truss Structures ◽  
Scaling Method ◽  
Element Analysis ◽  
And Performance

Mesoscale truss structures are cellular structures that have support elements on the order of centimeters. These structures are engineered for high performance and have applications in industries where a high strength-to-weight ratio is desired. However, design of mesoscale truss structures currently requires some form of topological optimization that slows the design process. In previous research, a new Size, Matching and Scaling method was presented that eliminated the need for topological optimization by using a solid-body finite element analysis combined with a library of lattice configurations to generate topologies. When compared to topological optimization, results were favorable: design times were significantly reduced and performance results were comparable. In this paper, we present a modified Size Matching and Scaling design method that addresses key issues in the original method. Firstly, we outline an improve methodology. Secondly, we expand the library of configurations in order to improve lattice performance. Finally, we test the updated method and library against design examples.

scholarly journals Prediction of strength and durability properties of HPC composites using Adaptive Neuro-fuzzy Inference System

2020 ◽  
Vol 184 ◽  
pp. 01102
Author(s):  
P Magudeaswaran. ◽  
C. Vivek Kumar ◽  
Rathod Ravinder
Keyword(s):  
Fuzzy Inference System ◽  
High Performance ◽  
Fuzzy Inference ◽  
High Performance Concrete ◽  
Intelligent System ◽  
Computing Methods ◽  
Inference System ◽  
Performance Requirements ◽  
Neuro Fuzzy ◽  
And Performance

High-Performance Concrete (HPC) is a high-quality concrete that requires special conformity and performance requirements. The objective of this study was to investigate the possibilities of adapting neural expert systems like Adaptive Neuro-Fuzzy Inference System (ANFIS) in the development of a simulator and intelligent system and to predict durability and strength of HPC composites. These soft computing methods emulate the decision-making ability of human expert benefits both the construction industry and the research community. These new methods, if properly utilized, have the potential to increase speed, service life, efficiency, consistency, minimizes errors, saves time and cost which would otherwise be squandered using the conventional approaches.

Vibration Control of Rotor Systems With Noncollocated Sensor/Actuator by Experimental Design

1997 ◽  
Vol 119 (3) ◽  
pp. 420-427 ◽  
Author(s):  
S. M. Yang ◽  
G. J. Sheu ◽  
C. D. Yang
Keyword(s):  
Experimental Design ◽  
Vibration Suppression ◽  
Controller Design ◽  
Design Method ◽  
Control Technique ◽  
Design Parameters ◽  
Rotor Systems ◽  
Sensor Actuator ◽  
Operation Speed ◽  
And Performance

This paper presents a controller design methodology for vibration suppression of rotor systems in noncollocated sensor/actuator configuration. The methodology combines the experimental design method of quality engineering and the active damping control technique such that their advantages in implementation feasibility and performance-robustness can be integrated together. By using the locations of sensor/actuator and the feedback gains as design parameters, the controller design is shown to achieve a near optimal performance within the two-sigma confidence among all possible parameter combinations. Compared with LQ-based designs, the controller order is smaller and it is applicable to systems in an operation speed range. In addition, neither preselected sensor/actuator location(s) nor state measurement/ estimation is needed.

Fast Control of Linear Systems Subject to Input Constraints

1998 ◽  
Vol 122 (1) ◽  
pp. 18-26 ◽  
Author(s):  
P. Tomas Larsson ◽  
A. Galip Ulsoy
Keyword(s):  
High Performance ◽  
Actuator Saturation ◽  
Design Method ◽  
Nonlinear Behavior ◽  
Lyapunov Stability Theory ◽  
Performance Ratio ◽  
Efficient Design ◽  
Control Effort ◽  
Automatic Control Systems ◽  
Control Of Linear Systems

Efficient design of high performance automatic control systems is extremely important for high technology systems. To get the best hardware cost-to-performance ratio, it is desirable to design a controller that takes full advantage of actuator capabilities, but this can lead to nonlinear behavior due to actuator saturation. The saturation nonlinearities in the system may have severe effects on system performance due to, for example, integrator windup. In this paper, a new design method is presented based on Lyapunov stability theory. By incorporating the actuator constraints directly in the design method, better utilization of the available control effort can be ensured in achieving desired system behavior. [S0022-0434(00)01801-3]

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