Browse Topic: Adaptive control

Items (51)

Performance optimization of road noise system based on convolutional neural network

2022-01-037003/29/2022

Abstract: In view of the traditional road noise active control system being unable to adapt to different types of road excitations, a convolutional neural network method is designed to identify the road surface in advance, and the convergence factor of the road noise system algorithm is adaptively controlled by different road input to make the vehicle on different roads. To achieve the best noise reduction effect. This paper collects three typical road images, uses migration learning to train and test the network, and combines the recognition results with the road noise active control algorithm for joint simulation. The results show that the road surface can be recognized accurately by using convolutional neural network. According to different road types, by adjusting the algorithm convergence factor, the noise reduction effect of the vehicle can be effectively improved.

Shi, Chenlu, Zhu, Yugang, Sen, Zheng, Ge, Xu, lv, Xiao, Zihong, Ling

Active control of Camber and Toe angles to improve vehicle Ride Comfort

2022-01-112003/29/2022

This paper is part of the European OWHEEL project. It proposes a method to improve the comfort of a vehicle by adaptively controlling the Camber and Toe angles of a rear suspension. The purpose is achieved through two actuators for each wheel, one that allows to change the Camber angle and the other the Toe angle. The control action is dynamically determined based on the error between the reference angle and the actual angles. The reference angles are not fixed over time but dynamically vary during the manoeuvre. The references vary with the aim of maintaining a Camber angle close to zero and a Toe angle that follows the trajectory of the vehicle during the curve. This improves the contact of the tire with the road. This solution allows the control system to be used flexibly for the different types of manoeuvres that the vehicle could perform. An experimentally validated sports vehicle was used to carry out the simulations. The original rear suspension is a Trailing-arm suspension. It

Marotta, Raffaele, Strano, Salvatore, Terzo, Mario, Tordela, Ciro, Ivanov, Valentin

Optimal Design for Maximum Fundamental Frequency and Minimum Intermediate Support Stiffness for Uniform and Stepped Beams Composed of Different Materials

2020-01-501402/06/2020

The minimum support stiffness that achieves the maximum modal frequencies or critical speed is very important in the design of mechanical systems. The optimal values of the intermediate support stiffness and geometrical parameters of uniform and stepped Timoshenko beams composed of single or two materials are studied in order to maximize the modal frequency and minimize the intermediate support stiffness. Dynamic stiffness matrix (DSM) method and multi-objective particle swarm optimization (MOPSO) algorithm are used together to evaluate new optimal parameters. For single material, the results show that for uniform thick beams, the optimal maximum fundamental frequency and minimum intermediate support stiffness are lower than those of Bernoulli-Euler beams. In addition, the optimal design for stepped beams made of two metallic materials is investigated. For three different metallic combinations, gain factors of 1.561 to 2.745 are obtained for a beam without intermediate support

Ahmed, Elsawaf, Tamer, Elsayed, Said, Farghaly

Vibration Control of an Active Seat Suspension System Integrated Pregnant Woman Body Model

2019-01-017204/02/2019

Proportional-integral-derivative (PID) controller is effective, popular and cost effective for a lot of scientific and engineering applications. In this paper, PID and fuzzy-self-tuning PID (FSTPID) controllers are applied to improve the performance of an active seat suspension system to enhance the pregnant woman comfort. The equations of motion of thirteen-degrees-of-freedom (13-DOF) active seat suspension system incorporating pregnant woman body model are derived and simulated. PID gains are tuned and estimated using genetic algorithm (GA) to formulate GA PID controller. In FSTPID, fuzzy logic technique is used to tune PID controller gains by selecting appropriate fuzzy rules using Matlab/Simulink software. Both controlled active seat suspension systems are compared with a passive seat suspension. Suspension performance is evaluated under bump and random road excitations in order to verify the success of the proposed controllers. Theoretical results reveal that the proposed

Ali, Shaimaa A., Metered, H., Bassiuny, A. M, Abdel-Ghany, AM

Circuit Models for Robust, Adaptive Neural Control

TBMG-3376602/01/2019

This project seeks to reproduce the neural circuits used by the nematode Caenorhabditis elegans for locomotion. Caenorhabditis elegans is a small (~1.2 millimeter) nematode found in rotting fruit in many parts of the world. It feeds on bacteria and is neither parasitic nor pathogenic. Although capable of sexual reproduction, most laboratory strains reproduce primarily as self-fertilizing hermaphrodites, with each adult hermaphrodite producing approximately 300 progeny (Figure 1).

Circuit Models for Robust, Adaptive Neural Control

19AERP02_0802/01/2019

Understanding a nematode's simple circuit could provide a foundation for understanding much more complex behaviors. Air Force Research Laboratory, Arlington, Virginia This project seeks to reproduce the neural circuits used by the nematode Caenorhabditis elegans for locomotion. Caenorhabditis elegans is a small (∼1.2 millimeter) nematode found in rotting fruit in many parts of the world. It feeds on bacteria and is neither parasitic nor pathogenic. Although capable of sexual reproduction, most laboratory strains reproduce primarily as self-fertilizing hermaphrodites, with each adult hermaphrodite producing approximately 300 progeny (Figure 1). C. elegans is a very simple organism, with only 959 somatic cells in the adult hermaphrodite. Although the total number of cells is small, they are differentiated into the standard array of tissues: 302 neurons, 95 body muscle cells, 32 gut cells, etc. In addition, the position, morphology, and lineage of each cell are reproducible from animal to

Implementation of an Extended Model for Multi-Axle Articulated Vehicle with Nonlinear Tire Model

2017-01-043603/28/2017

A new extended planar model for multi-axle articulated vehicle with nonlinear tire model is presented. This nonlinear multi-axle articulated vehicle model is specifically intended for improving the model performance in operating regimes where tire lateral force is near the point of saturation, and it has the potential to extend the specific axles model to any representative configuration of articulated vehicle model. At the same time, the extended nonlinear vehicle model can reduce the model's sensitivity to the tire cornering coefficients. Firstly, a nonlinear tire model is used in conjunction with the 6-axle planar articulated vehicle model to extend the ranges of the original linear model into the nonlinear regimes of operation. Secondly, the performance analysis of proposed nonlinear vehicle model is verified through the double lane change maneuver on different road adhesion coefficients using TruckSim software. Simulation results demonstrate that the proposed vehicle model shows

Zhu, Tianjun, Li, Bin

Resistance Spot weld in Vehicle Structures Using Dynamic Resistance Adaptive Control

2016-36-030310/25/2016

To highlight the importance of resistance spot weld in the automotive industry, it's important know that a vehicle has on average 4,000 welding spots [BROWN; SCHWABER 2000] and based on worldwide vehicle production in 2015 with 90.78 million vehicles produced [OICA, 2015], were performed more than 363 billion welding spots. The number of machines in manual and automatic workstations (robots), based on 20 points by equipment and production of 45 vehicles / hour add up more than 20 million of welding machines in all over world. According new production lines are being introduced using the adaptive dynamic resistance control the welding constant current control are being replaced, so understand this technology and know implement it with efficiency needs a deep knowledge in how dynamic resistance works and correlate his behavior with the problems that causes failures in welding, so is necessary give for the welding engineers this knowledge.

Reis, Frederico Fernandes, Furlanetto, Valdir, Batalha, Gilmar Ferreira

Residual Mode Filters

TBMG-2531809/01/2016

NASA has developed a unique control algorithm and synthesis method that uses a system’s output to modify control inputs to cause the system to track a reference model or a fixed value in the presence of unmodeled system dynamics, varying operating environments, and unpredictable disturbances. The unique feature of this algorithm is the ability to instantaneously adapt the system according to its output, rejecting persistent disturbances, and ultimately improving the system’s performance. This makes the controller ideally suited for applications where there are unknown modeling parameters or uncertain operating environments. Many aerospace systems must function in unknown or highly variable environments. This technology allows the system to achieve its objectives in these types of unpredictable environments. In comparison to current adaptive controller technologies, the addition of residual mode filters allows operation when flexible modes are present that could inhibit the controller

Testing an Artificial Pancreas

TBMG-2414603/01/2016

A team of scientists from the University of Virginia (UVA) School of Medicine and the Harvard John A. Paulson School of Engineering and Applied Sciences developed a project to turn an ordinary smartphone into an artificial pancreas that has since received a $3.4 million grant from the National Institutes of Health. Now, researchers are beginning one of the largest-ever long-term clinical trials of a system designed to help regulate blood sugar levels of individuals with type 1 diabetes mellitus. The “artificial pancreas” system will be tested in 240 patients at nine sites in the US and Europe. Two six-month trials are beginning in early 2016, in collaboration with a half dozen other institutional partners.

Controlling Execution Sequence Using Tactile-Classification During Manipulation by a Humanoid Robot

07/01/2015

It is necessary to track system state during robotic manipulation. System state is defined to be manipulator and environment configuration. Without tracking, the robot is ignorant of the outcomes of its actions. State tracking enables the robot to respond to sub-task failures. Tracking system state is difficult for complex robots that incorporate hundreds of individual sensor signals. It is difficult to determine which signals are relevant and which are not, and to find low dimensional representations of system state.

Electrical Interface Between Numerical Control and Machine Tools

EIARS431 (Current)07/01/2015

This standard covers both active and passive aspects of the electrical interface between the Numerical Control (NC) and the machine power and logic control, motor drive equipment, and other electrical apparatus on or associated with the machine tool. It covers:

Systems Management Council

Active Control of Structure-Borne Road Noise Based on the Separation of Front and Rear Structural Road Noise Related Dynamics

2015-01-222206/15/2015

Axle forces from tire-road interaction can excite different structural resonances of the vehicle hence a high number of sensors is required for observing and separating all the vibrations dynamics that are coherent with the cabin noise. Feed-forward road noise control strategies adopted so far rely mainly on capturing these dynamics and thus the number of sensors constitutes one major limitation of this approach. Therefore there is a necessity for reducing the number of sensors without degrading the performance of an ANC system. In the past coherence function analysis has been found to be a useful tool for optimizing the sensor location. In this case coherence function mapping was performed between an array of vibration sensors and the headrest microphones in order to identify the locations on the structure that are highly correlated with road noise bands in the compartment. A vehicle with an advanced suspension system was used for applying the method and defining some locations as

Zafeiropoulos, Nikos, Ballatore, Marco, Moorhouse, Andy, Mackay, Andy

Method for Improving Control Systems with Normalized Adaptation by Optimal Control Modification

05/01/2015

A new technology has been developed for improving performance and stability of control systems. This method represents a significant advancement in the state-of-the-art of adaptive control technology. The present invention is a new type of adaptive control law, called optimal control modification, which blends two control technologies together: optimal control and adaptive control.

Automatic Tuning of Two-Degree-of-Freedom PID Control for Engine Electronic Throttle System

2010-01-015604/12/2010

Engine Electronic Throttle Control (ETC) systems are gaining success in high volume applications. This system helps to improve overall engine and vehicle performance, as well as facilitate the function integration of related control features. The requirement for an ETC system is that it fulfills the commanded throttle plate opening as quickly and accurately as possible. Because of nonlinearity of the electronic throttle system, gain-scheduled control is often used. A method to automatically tune the control for each operating region is needed. In this paper the engine electronic throttle is considered as having dominant linear dynamics for each operating region. A Two-Degree-of-Freedom (2-DOF) PID controller and a method of using Model Reference Adaptive Control (MRAC) algorithm to automatically tune the PID control gains are designed. With this approach, control performance enhancement from initial control settings can be realized with closed loop testing, without the need of a plant

Jiang, Shugang, Smith, Michael, Kitchen, James

Optimization of PID Control for Engine Electronic Throttle System Using Iterative Feedback Tuning

2009-01-037004/20/2009

The Electronic Throttle Control (ETC) system is more and more used and increasingly becoming a standard part of the engine. It controls the amount of air intake into the cylinders by precisely positioning the throttle plate at the desired opening. An ETC system provides the possibility of improving the overall engine and vehicle performance because with such a mechanism, the engine controller can decide and set the throttle position not only based on driver intention, but also taking into consideration the specific engine operation mode information, such as safety factors, emission constraints, etc. After the throttle position target is determined, the requirement for the ETC system is that the throttle plate should achieve the commanded position as accurately and as quickly as possible. In many cases the controller is designed by first establishing a model of the electronic throttle system using experimental identification. However, due to such nonlinear effects as static friction

Jiang, Shugang, Smith, Michael H., Kitchen, James

Developments in Adaptive Filtering and System Identification

TBMG-488708/01/2008

Progress has been made on several fronts in a continuing program of research oriented toward the development of real-time algorithms, and computer and control systems that utilize the algorithms, for adaptive filtering, prediction, and system identification with improved efficiency and numerical stability in applications that involve large numbers of channels and high filter orders. Potential applications include adaptive optics, optical communications, target tracking, image processing, blind identification and deconvolution in wireless communications, and active control of noise and vibration.

Closed Loop Controlled High Speed Induction Generators Using Adaptive Control Technique

2006-01-305111/07/2006

High speed generators offer very high power density solution for electric power requirements in airborne applications. Induction generators are suitable for the high speed environment because of the ability to provide controlled voltage and power output with a reliable rotor construction. An important issue of power control for the high speed induction generator is maintenance of the steady state output voltage within the specified limits over the entire range of speed and load variations. This paper discusses the development of a closed loop control system for a 200 kW induction generator under different load conditions. Field Oriented Control (FOC) schemes are implemented to both operate the generator in the maximum torque conditions available and to decouple the maximum torque from the field under transient and steady state operation. FOC uses Classical Proportional and Integral (PI) controllers for regulation because of their simple implementation. However, PI controllers do not

Elkhomri, Ottman, Vaidya, Jay G, Gregory, Earl

Controlling Attitude of a Solar-Sail Spacecraft Using Vanes

TBMG-9507/01/2006

A paper discusses a concept for controlling the attitude and thrust vector of a three-axis stabilized Solar Sail spacecraft using only four single degree of freedom articulated spar-tip vanes. The vanes, at the corners of the sail, would be turned to commanded angles about the diagonals of the square sail. Commands would be generated by an adaptive controller that would track a given trajectory while rejecting effects of such disturbance torques as those attributable to offsets between the center of pressure on the sail and the center of mass. The controller would include a standard proportional + derivative part, a feed forward part, and a dynamic component that would act like a generalized integrator. The controller would globally track reference signals, and in the presence of such control actuator constraints as saturation and delay, the controller would utilize strategies to cancel or reduce their effects. The control scheme would be embodied in a robust, nonlinear algorithm that

Innovative Protection Strategies for Automobile EE-Systems

2005-01-173704/11/2005

Modern technologies allow innovative steps to optimize vehicle architectures, system behavior, maintenance and costs. The need for protecting aggregates, control units and wires has been solved by using more or less sophisticated fuse applications. In the meantime there are chances to provide automobile applications with electronic protective circuits, which allow highly sophisticated adaptable and maintenance-free protection strategies.

Advanced In-cycle and Cycle-to Cycle On-line Adaptive Control for Thermoforming of Large Thermoplastic Sheets

2005-01-152004/11/2005

This paper presents a control system for the thermoforming of large sheets. The system has three main purposes: Its primary purpose is for cycle-to-cycle control of the sheet temperature map as predicted by the thermoforming simulation. Its secondary purpose is to tune the simulation to the actual process through on-line characterization of some of the material and machine characteristics so that the simulation's predictions are reconciled with the machine sensors outputs. Lastly it can characterize on-line a number of independent and fast acting sub-models that allow for in-cycle control of some process parameters.

Girard, Patrick, di Raddo, Robert, Thomson, Vince, Boulet, Benoit

Proposed Real Time Performance Evaluation of Two Types of Adaptive Neural Network Controllers

2004-01-313211/02/2004

This paper addresses the problem of real time assessment or evaluation of an adaptive neural network controller performance. Complex control systems require robust controllers that handle a large variety of operating conditions. In these circumstances controllers must be adaptive or robust with respect to inaccurate plant models and changes in the plant dynamics. One of the major difficulties in adaptive controller is proof of stability of the update mechanism. In the case where a conventional controller is available it is convenient to toggle it based on controller performance. This paper presents a proposed approach to evaluate the performance of an adaptive sigma pi neural network controller.

Model Based Control for a Pressure Control Type CVT

2004-40-003108/23/2004

A model based control algorithm for the pressure control type CVT has been developed. First, a P-line is proposed from the steady state relationship between the primary and secondary pressure for the given speed ratio to predict the shift performance. The P-line shows the pressure difference from the steady state primary pressure to the maximum(or minimum) pressure available for the given secondary pressure. It is found from the P-line that the bigger the pressure difference, the faster the shift speed. Based on the steady state characteristics of the pressure control type ratio control valve(RCV), the model based control algorithm is proposed. In the model based control, ratio control solenoid valve(RCSV) control duty is supplied in the feedforward loop. The following findings are obtained from the experiments; (1) linear control algorithm such as PID type controller can be used for the pressure control type CVT while nonlinear or adaptive control logic should be applied for the flow

Ryu, Wansik, Nam, Juhyun, Kim, Hyun Soo, Lee, Yongjoon

Control and Operating Behavior of Continuously Variable Chain Transmissions

2004-40-001508/23/2004

A new adaptive controller layout for chain converters for universal use in different applications and set-ups is being presented. Based on the control structure chosen for synchronization of the claw couplings of a chain converter type i2-transmission during range shifts, a universal control layout was developed. Both the conventional clamping system for the well known PIV1-based chain converter and a newly developed pressure controlled clamping system were taken into account. As the most important non-linearity the ratio of clamping forces between driving and driven pulley (ζ-value) for steady state operation was mapped in a characteristic diagram and is being adapted during normal operation. Besides improvements in performance and better availability of information for diagnostic purposes, an open loop control of the rate of ratio change becomes possible.

Exploring Anthropometric Data through Cluster Analysis

2004-01-218706/15/2004

Anthropometric databases consisting of both multimedia and relational content are increasingly becoming commonplace. These databases are huge and contain data with diverse formats, representations and models. Data mining provides a powerful mechanism to further explore and explain the data as contained in these heterogeneous repositories, focusing on discovering new relationships which cannot be found using standard information retrieval techniques. In particular, cluster analysis is a data mining technique which is used to group data records into unlabeled classes, e.g. to group individuals with similar body types, income and education levels into a cluster, using unsupervised learning. This paper introduces cluster analysis as a method to explore 3D body scans together with the relational anthropometric and demographic data as contained in an integrated multimedia anthropometric database. The paper provides an overview of different cluster analysis algorithms and discusses the

Abdali, Osama, Viktor, Herna, Paquet, Eric, Rioux, Marc

Event-Driven Random-Access-Windowing CCD Imaging System

TBMG-2925701/01/2004

A charge-coupled-device (CCD) based high-speed imaging system, called a real-time, event-driven (RARE) camera, is undergoing development. This camera is capable of readout from multiple subwindows [also known as regions of interest (ROIs)] within the CCD field of view. Both the sizes and the locations of the ROIs can be controlled in real time and can be changed at the camera frame rate. The predecessor of this camera was described in "High-Frame-Rate CCD Camera Having Subwindow Capability"(NPO-30564) NASA Tech Briefs, Vol. 26, No. 12 (December 2002), page 26. The architecture of the prior camera requires tight coupling between camera control logic and an external host computer that provides commands for camera operation and processes pixels from the camera. This tight coupling limits the attainable frame rate and functionality of the camera.

Evaluation of Adjustment Strategies for Adaptive Shewhart Quality Control Charts

2003-01-283610/27/2003

The present paper valuates the statistical and economic performance of Adaptive Shewhart quality control chart strategies which allow at least one of the design parameters (sample size n, sampling interval h and control limit coefficient k) to change in real time based on the actual values of the sample statistics. The automation of production processes more and more often requires a real-time analysis of control charts to make prompt corrections to the process under study. So, by evaluation of the different control chart adjustments one can assure better consistent upgrading of reliability through improved quality control, which provides an economic mean for attaining the required product-goals.

Brun, Alessandro, Novakova, Galia

Biomorphic Gliders

TBMG-731204/01/2001

Biomorphic gliders are small robotic microflyers proposed for use in scientific exploration of planetary atmospheres and terrains that capture some key features of insect and bird flight. Biomorphic gliders as biomorphic flight systems are a subset of biomorphic explorers. The multidisciplinary system concept of "Biomorphic Explorers" represents small, dedicated, low-cost explorers that possess some of the key features of biological systems, not easily captured by conventional robotic systems. Such features particularly include versatile mobility, adaptive controls, bioinspired sensor mechanisms, biomorphic sensor fusion, biomorphic communications, biomorphic cooperative behavior, distributed operations, and biomorphic energy generation/conversion. Significant scientific and technological payoff at a low cost is realizable by using the potential offered by a large number of such cooperatively operating biomorphic explorer units in concert with the traditional exploration platforms such

Development of a new all-wheel-drive control system

2000-05-024806/12/2000

The new all-wheel-drive control system has been developed to improve stability, handling performance and safety under various road/operating conditions. This system consists of center differential and hydraulic transfer clutch which is electronically controlled according to road/operating condition. The center differential of this control system is in the form of composite planetary gear system without a starter ring. The output torque of transmission is distributed by this center differential 35% to front wheels and 65% to the rear wheels. It improves handling performance on dry road when the transfer clutch is open. On the other hand, when the slippery road condition is detected or motion of vehicle is disturbed, the actual torque distribution is modified by electronically controlled transfer clutch to improve stability and safety. In the estimation of the coefficient of road friction (\gm), lateral stiffness of tire is identified with parameter identification law of adaptive control

Matsuno, Koji, Nitta, Ryo, Inoue, Koichi, Ichikawa, Katsufumi, Hiwatashi, Yutaka

Adaptive Variable Bias Control for Magnetic Bearings

TBMG-2953202/01/2000

Adaptive variable bias control (AVBC) is an improved technique for controlling the currents supplied to the electromagnets in magnetic bearings. In AVBC, the bias currents are varied in such a way as to reduce overall power consumption.

Biomorphic Explorers

TBMG-3235309/01/1998

"Biomorphic explorers" are a class of proposed small robots that would be equipped with microsensors and would feature animallike adaptability and mobility. These robots would capture key features, a specific design or function found in nature, taking advantage of general animal mechanical designs and neural functions that have evolved to enable animals to move through various environments. These robots are conceived for use in remote, hostile, and/or inaccessible terrestrial and other planetary environments, where they would be used to perform such diverse functions as acquisition of scientific data, law-enforcement surveillance, or diagnosis for precise, minimally invasive medical treatment. Depending on the specific environment to be explored, a biomorphic explorer might be designed to crawl, hop, slither, burrow, swim, or fly.

LTI Approach to Adaptive Narrow-Band Feedforward Control

TBMG-3222603/01/1998

A unified theory of linear time-invariant (LTI) representations has been developed for use in the analysis and design of adaptive, narrow-band, feedforward controllers for systems characterized by harmonic regressors (the term "harmonic regressor" is defined below). Such controllers are used, for example, to suppress harmonic noise and vibrations; the basic idea is to track disturbance tones actively and "notch" them by use of high-gain feedback to achieve large attenuation. The LTI approach embodied in the unified theory makes it possible to apply established LTI theoretical concepts to the adaptive-feedforward-control design problem, and thus to design stable, high-performance controllers while avoiding the complexities and risks associated with nonlinear and/or time-varying control loops.

Improved Design of Adaptive Feedforward Tracking Systems

TBMG-3224603/01/1998

An improved method of analysis and design offers the potential to enhance the performances of adaptive feedforward tracking systems. The method can, in principle, make it possible to increase such performance measures as rates of convergence and noise-cancellation ratios, without need for additional hardware. The method is applicable to communication systems, adaptive equalizers, adaptive systems for canceling noise from machinery, advanced vibration-suppressing systems, and echo-canceling systems. The method is particularly significant for overparameterized adaptive feedforward systems, which are very important in practice; they are used to ensure high-performance "tuning" of key signals in a wide range of terrestrial and outer-space applications, including the ones listed above.

Application of Adaptive Control to High-Speed Aluminum Machining

97225106/03/1997

Adaptive control enables more productive use of high speed numerically controlled milling machines. With adaptive control, machines are programmed for optimum material removal, with the controller automatically reducing the material feed rate when heavy load conditions are encountered. The authors outline advantages of adaptive control and describe their testing technique for determining appropriate values for making maximally effective use of adaptive control.

Escobedo, Larry, Wilson, Scott, Force, Dave, Smith, Robin, Robertson, Mike, Deneen, Kevin, Naylor, Mark

An Open Simulation Architecture for the Development of Complex Embedded Systems Using Distributed Objects

97093102/24/1997

Simulation is by now considered an essential activity prior to the implementation of complex, embedded real-time systems such as automotive control units. However, the models required for a meaningful systems simulation are often heterogeneous -(such as software, hardware, hydraulics, mechanics etc.) and developed in parallel using different tools from different vendors, thereby making comprehensive system simulations very hard. An open architecture for cosimulation of heterogeneous systems and its first implementation within the MATRIXx tool family, based on the Common Object Request Broker Architecture (CORBA) is described. It allows plug-and-play cosimulations between a wide range of simulation tools and can serve as the foundation of sophisticated virtual prototyping and systems simulation activities.

Ernst, Johannes

Control System Requirements to Support Intelligent Sensor-Based Manufacturing

96163905/01/1996

This paper presents a description of intelligent sensor-based manufacturing, reviews previous research in this area, and identifies control system requirements necessary to support successful application of this technology. Current production control systems inhibit the successful implementation of advanced manufacturing control technologies. It is often difficult, if not impossible, to integrate new sensing technologies and advanced control algorithms with existing control platforms. To address this difficulty, hardware and software needs to support intelligent sensor-based manufacturing are discussed.

Furness, Richard J., Jones, Steven D., Rankin, James S., Muth, Michael J., Wei, Kuang C., Cooper, John C.

Adaptive Control Strategies for a Switchable Damper Suspension System

96093902/01/1996

Previous work to examine the performance of a variety of control strategies for a switchable damper suspension system is extended to include an adaptive suspension. The aim of this adaptation algorithm is to maintain optimal performance over the wide range of input conditions typically encountered by a vehicle. The adaptive control loop is based on a gain scheduling approach and two strategies are examined both theoretically and experimentally using a quarter vehicle test rig. For the first strategy, the gains are selected on the basis of root mean square (r.m.s.) wheel acceleration measurements whereas in the second approach the r.m.s. value of suspension working space is used. A composite input is used consisting of sections of a road input disturbance of differing levels of magnitude in order to test the control systems' abilities to identify and adapt efficiently as the severity of the road input changes. Both simulated and measured results are used to investigate design decisions

Soliman, A. M. A., Abd El-Tawwab, A. M.

Real Time Engine Control Using STR in Feedback System

95000702/01/1995

This research project involved work into the application of a Self Tuning Regulator (STR), one type of adaptive control technique used in the real-time control of internal combustion engines in order to enhance the air/fuel controllability. We concentrated on the target air/fuel and output air/fuel values, and applied adaptive control to the feedback system. With this structure, equivalence transformation of a conventional PID feedback controller to STR can be performed. Through simulation, it was confirmed the effectiveness of the controllability and disturbance robustness, and controllability verification tests were performed using real-time engine control on an actual vehicle in the FTP75 LA-4 mode. This resulted in a dramatic improvement in air/fuel controllability.

Maki, Hidetaka, Akazaki, Syusuke, Hasegawa, Yusuke, Komoriya, Isao, Nishimura, Yoichi, Hirota, Toshiaki

Active Engine Mount with Piezo-Actuator for Vibration Control

93020103/01/1993

Electronics technology has made remarkable progress in recent years, and in the field of automobile noise and vibration control, it has attracted the interest of engineers due to its potential for use in the active control of vibration isolators. This report describes an investigation on reducing automobile vibration caused by engine explosion using a piezo actuator(PA) engine mount. Piezo actuator has a very high speed response but the displacement is generally very small. Therefore PA mount requires an amplitude enlargement mechanism. Here, an active mount with an enlargement mechanism incorporated was developed. For the control system, the adaptive control algorithm proposed by S. J. Elliott et al. was employed as a base, and a control rule against limitation in the power of the actuator was used in combination with it. A significant attenuation of the vibration of the dominant harmonic order in idling was achieved. The results are reported in the following pages.

Ushijima, Takao, Kumakawa, Syoichi

Identification and Control of Nonlinear Hydraulic System

92162209/01/1992

Nonlinearities in a hydraulic system, such as deadband, saturation, friction, hysteresis etc., are usually not known exactly. If they are not properly compensated for, the performance of the system will suffer. This paper discusses the identification and control of this type of nonlinear hydraulic systems. The emphasis is on the deadband. A method is proposed in this paper to estimate its characteristics, and a piecewise-linear preload element can be used to compensate for the deadband in the design of the controller. This combination results in the closed-loop behaviour of a system with a deadband being the same as that of its linear portion.

LeQuoc, S., Xiong, Y. F.

Adaptive PID Control Application for an Airflow Monitoring System

92122007/01/1992

This paper discusses the application of adaptive control, using a set of self-tuning PID control laws and a recursive least squares parametric identification method with a variable forgetting factor. This adaptive controller has been developed and applied to a computer simulated airflow monitoring system to maintain a specific setpoint against various airflow rates. The computer simulations show that the adaptive control algorithm developed meets the above control objective, and the system performance is superior to that using a conventional fixed-parameter PID controller. The developed adaptive control technique can be applied for the temperature control of a process with varying plant's characteristics.

Lam, Bon D., Lam, Chun Ho

Adaptive Electronic Tractor Shift Control System

90159209/01/1990

The ability to shift gears on a moving farm tractor without using the clutch, makes the operator's job easier, and improves his productivity. This feature, often referred to as “powershift”, has been implemented electrically and hydromechanically by farm equipment manufacturers. The Case Corp 5100 Series Maxxum tractor offers an electronic powershift in which clutch pressure, timing and hydraulic fluid temperature are utilized for simple adaptive shift control. This paper describes the strategy incorporated into the Maxxum control system.

Ross, Larry F., Panoushek, Dale W.

Automotive Adaptive Driver Controls, Manual

J1903_199008 (Historical)08/01/1990

This SAE Recommended Practice establishes a uniform procedure for assuring the manufactured quality, installed utility, and service performance of certain automotive adaptive products, other than those provided by the vehicle manufacturer, intended to provide driving capability to persons with physical disabilities. These devices function as adaptive appliances to compensate for lost or reduced performance in the arms or legs, or both, of the driver. Some of the devices are designed to transfer foot functions to the hands, hand functions to the feet, or functions from one side of the body to the other.

Adaptive Devices Standards Committee

Discovery Strategy in Statistical Control of an Adaptive Process

90087604/01/1990

Adaptive control, based on modeling of a manufacturing process and coupled with predictive control methods, allows for adjustment of nonrobust process variables while maintaining the ability to statistically monitor the cause system for unexpected change. This strategy recognizes both the need for continual improvement in process operation and the need to face the reality of current process under-standing and practical commercial considerations. It incorporates both active and passive use of statistical methods for improving the quality of process output while retaining the ability to detect new process changes. A final feature is the opportunity to refine engineering knowledge concerning process interaction and the adaptive decision model.

Mosier, James A.

Space Thermal Systems - The Challenge of Adaptive Controls

84096507/01/1984

The rapid and ever increasing development of microprocessor based controllers in a wide and diversified range of applications leads to consider their candidacy on spacecraft systems. Easy programmability, potentials for implementing the most complex logical control laws, and their “adaptivity” form the backbone of their many interesting features. In this perspective, the paper illustrates an application of adaptive control, within a closed air loop, for thermal conditioning of a typical biochemical experiment cell to be flown in space and addresses some aspects specific to the underlying control philosophy.

Marchis, Vittorio, Nervegna, Nicola

Microcomputer Applications for Controlling Welding Operations

80016902/01/1980

A configuration of micro and minicomputers in a hierarchical is used to provide adaptive control for a resistance welding process. The specific application of aluminum welding is reviewed and the resulting control system defined. The system concept, sensors, procedures for adaptive control, and operator interface are outlined.

Automatic and Adaptive Controls for Construction Equipment

75076502/01/1975

Automatic/adaptive controls for large earthmoving equipment have been developed, and have proven to be effective in improving the performance of these machines while reducing the skill required of the operators. These controls speed up earthmoving tasks, make it easier for the machines to work at night, and contribute to lower construction costs. Controls suitable for motor graders, scrapers and bulldozers have been demonstrated.

Ward, Carter J.

Adaptive Control and Automobile Manufacture

71000202/01/1971

The paper discusses two general definitions of adaptive control in an attempt to determine whether adaptive controls can effectively be employed in low-cost, high-quality auto production. Uses of adaptive control in various industries are described. Future applications are suggested in auto manufacture. Solid-state circuitry and computer control are major areas of such adaptive control application which are explored.

Lincoln Tunnel Traffic Control Experiment

70019202/01/1970

A description is given of a control experiment aimed at the development of a computer methodology for improving the flow of traffic through the Lincoln Tunnel of New York City. Some remarks are given on the potential spin-offs from this experiment which may influence the development of other traffic control systems.

Gazis, Denos C., Bennett, Brian T.

Computers in Dimensional Measurement

68065502/01/1968

Manufacturing processes of discrete parts have increased in complexity and productivity with a simultaneous tightening of dimensional tolerances. Computers, which have been at the forefront of this dramatic manufacturing evolution, are now being applied in the dimensional quality control function. These applications include simple error and tolerance calculations as well as more sophisticated data storage, adaptive control, statistical error analysis, and optimizing routines. Computers are being dedicated to discrete component process control as well as used on a time-sharing basis. This paper explores the development and application of computerized measurement techniques to acquaint the technical manager-process planner with this new and growing field.

Birrell, Kirk E.

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