In-phase rear-wheel steering, where rear wheels are steered in the same direction of front wheels, has been widely investigated in the literature for vehicle stability improvements along with stability control systems. Much faster response can be achieved by steering the rear wheels automatically during an obstacle avoidance maneuver without applying the brakes where safe stopping distance is not available. Sudden lane change movements still remain challenging for heavy articulated vehicles, such as tractor and semitrailer combinations, particularly on roads with low coefficient of adhesion. Different lateral accelerations acting on tractor and semi-trailer may cause loss of stability resulting in jackknifing, trailer-swing, rollover, or slip-off. Several attempts have been made in the literature to use active steering of semi-trailer’s rear wheels to prevent jackknifing and rollover. However, loss of stability in an articulated vehicle is usually caused by an oversteered tractor, and

Sahin, Hasan, Akalin, Ozgen

Minimization of Electric Heating of the Traction Induction Machine Rotor

2020-01-056204/14/2020

The article solves the problem of reducing electric power losses of the traction induction machine rotor to prevent its overheating in nominal and high-load modes. Electric losses of the rotor power are optimized by the stabilization of the main magnetic flow of the electric machine at a nominal level with the amplitude-frequency control in a wide range of speeds and increased loads. The quasi-independent excitation of the induction machine allows us to increase the rigidity of mechanical characteristics, decrease the rotor slip at nominal loads and overloads and significantly decrease electrical losses in the rotor as compared to other control methods. The article considers the technology of converting the power of individual phases into a single energy flow using a three-phase electric machine equivalent circuit and obtaining an energy model in the form of equations of instantaneous active and reactive power balance. The quasi-independent excitation of the induction machine is

Nikiforova, Elena, Smolin, Victor, Gladyshev, Sergey

Observer for Faulty Perception Correction in Autonomous Vehicles

2020-01-069404/14/2020

Operation of an autonomous vehicle (AV) carries risk if it acts on inaccurate information about itself or the environment. The perception system is responsible for interpreting the world and providing the results to the path planning and other decision systems. The perception system performance is a result of the operating state of the sensors, e.g. is a sensor in fault or being adversely affected by the weather or environmental conditions, and approach to sensor measurement interpretation. We propose a trailing horizon switched system observer that minimizes the difference between reference tracking values developed from sensor fusion performed at an upper level and the values from a potentially faulty sensor based upon the convex combination of different sensor observation model outputs; the sensor observations models are associated with different sensor operating errors. The preferred observer target is a stationary landmark so as to remove additional uncertainty resulting from

Omwansa, Mark, Meyer, Rick, Asher, Zachary, Goberville, Nick

Fault Identification of Assembly Processes Using Fuzzy Set Theory

2020-01-048704/14/2020

Effective identification of sources of faults in modern manufacturing systems play a critical role in their performance and productivity. Tracking faults in a typical manufacturing system is inherently an inverse problem which makes it more challenging and difficult to solve. Presented in this article is the development of a new methodology for fault identification and root-cause analysis of complex assembly systems. A combination of a knowledge-based system and fuzzy set theory is used to develop this new technique, which is an intelligent system that mimics the behavior of an expert in the field, and can trace back the source or sources of the fault to the relevant station. Presented are the concepts of faults, their detection in an assembly line, and their generic characteristics. Study of the fault's fundamental properties reveals that there are certain levels of uncertainty involved in describing them. This has led us to the adoption of fuzzy set theory as a basic tool for

Mehrabi, Mostafa, Weaver, Jonathan, Mehrabi, Mostafa, Weaver, Jonathan

A Fuzzy Logic Based Energy Management of Grid Connected Hybrid Energy System

2019-28-007610/11/2019

On account of boundless presence and eco-friendly nature of Sustainable Energy Sources (SES) like Wind system, PV etc. power generation using SES became more captivating. This work concentrates on Energy Management (EM) of grid synchronized Hybrid Renewable Energy System (HRES) along with fuzzy logic control. Where the HRES system is a combination of solar panel and wind turbine as sources. Along with an electrical battery for energy storage via an interface using a DC-DC fused CUK-SEPIC converter with multiple input is adopted. This convertor is employed to incorporate the HRES to the main grid. In addition to grid integration a Fuzzy Logic Based (FLB) controller is employed to increase the efficiency of the system. The converter topology used is a crossbreed of wind and solar power system, which is used to eliminate the inclusion of MPPT. A two level framework is imposed, which includes a logic controller to ensure efficient EM when HRESs are interconnected with the grid. Simulation

Dayalan, Suchitra, Rathinam, Rajarajeswari, Pandey, Pranav, Adap, Mrutyunjay

Detection Method for Cavity Defects in Ballastless Track Structures of High-Speed Railways Based on Air-Coupled Ultrasonic Lamb Waves

10-03-02-001007/02/2019

This study proposes a method for the rapid detection and location of cavity defects in ballastless track structures of high-speed railways in service. First, the propagation of air-coupled ultrasonic Lamb waves in the ballastless track structure is studied. Theoretical calculation results show that the ultrasonic Lamb wave group velocity of the A2 mode in the track plate is 4000 m/s. Then, the excitation and reception methods of the air-coupled ultrasound are studied. Theoretical and experimental results show that the A2 mode Lamb wave can be generated by the 3.8° oblique incidence of the ballastless track structure. Finally, an experimental system for air-coupled ultrasonic testing is constructed. A pair of air-coupled ultrasonic probes is used to provide excitation and reception Lamb wave signals at an inclined angle of 3.8°, 20 mm away from the surface of the track plate, and 40 mm/step along the scanning direction. Experimental data indicate that interaction between the Lamb wave

Wenfa, Zhu, Wei, Shao, Xingjie, Chen, Xiangzhen, Meng, Haiyan, Zhang

Driver Risk Perception Model under Critical Cut-In Scenarios

2018-01-162608/07/2018

In China Cut-in scenarios are quite common on both highway and urban road with heavy traffic. They have a potential risk of rear-end collision. When facing a cutting in vehicle, driver tends to brake in most case to reduce collision risk. The timing and dynamic characteristics of brake maneuver are indicators of driver subjective risk perception. Time to collision (TTC) and Time Headway (THW) demonstrate objective risk. This paper aims at building a model quantitatively revealing the relationship between drivers’ subjective risk perception and objective risk. A total of 66 valid critical Cut-in cases was extracted from China-FOT, which has a travel distance of about 130 thousand miles. It is found that under Cut-in scenarios, driver tended to brake when the cutting in vehicle right crossing line. This time point was defined as initial brake time. Brake strength and brake speed were taken to describe brake maneuver. Average brake pressure (ABP) and acceleration at initial brake time

Ma, Xuehan, Feng, Zhiwei, Zhu, Xichan, Ma, Zhixiong

A Novel Approach to Create Dimensional Tolerance Requirements from Expert Knowledge

2017-01-024103/28/2017

Geometric Dimensioning and Tolerancing is used to describe the allowed feature variations regarding the product design. Tolerance specification is important in many stages of all phases on product development. The product development engineering need to define the symbols to use on the Feature Control Frame of every component. Since the component function has an increment on its complexity year over year, it is not trivial to define those symbols anymore. The determination of dimensional tolerance shall be preceded by careful specification of the types of tolerance and symbols that will be applied in controlled features. Poor tolerance specifications can increase the production cost, require late product changes or lead to legal issues. In this scenario, this paper presents a method to evaluate this engineering information for a few number of GD&T technical experts in a specific system, like chassis or powertrain, and translate it into dimensional tolerance requirements to support the

Murari, Thiago B., Ungaretti, Paulo, Moret, Marcelo A.

A Fuzzy Inference System for Understeer/Oversteer Detection Towards Model-Free Stability Control

2016-01-163004/05/2016

In this paper, a soft computing approach to a model-free vehicle stability control (VSC) algorithm is presented. The objective is to create a fuzzy inference system (FIS) that is robust enough to operate in a multitude of vehicle conditions (load, tire wear, alignment), and road conditions while at the same time providing optimal vehicle stability by detecting and minimizing loss of traction. In this approach, an adaptive neuro-fuzzy inference system (ANFIS) is generated using previously collected data to train and optimize the performance of the fuzzy logic VSC algorithm. This paper outlines the FIS detection algorithm and its benefits over a model-based approach. The performance of the FIS-based VSC is evaluated via a co-simulation of MATLAB/Simulink and CarSim model of the vehicle under various road and load conditions. The results showed that the proposed algorithm is capable of accurately indicating unstable vehicle behavior for two different types of vehicles (SUV and Sedan). The

Hirche, Benjamin, Ayalew, Beshah

A Model-Free Stability Control Design Scheme with Active Steering Actuator Sets

2016-01-165504/05/2016

This paper presents the application of a proposed fuzzy inference system as part of a stability control design scheme implemented with active steering actuator sets. The fuzzy inference system is used to detect the level of overseer/understeer at the high level and a speed-adaptive activation module determines whether an active front steering, active rear steering, or active 4 wheel steering is suited to improve vehicle handling stability. The resulting model-free system is capable of minimizing the amount of model calibration during the vehicle stability control development process as well as improving vehicle performance and stability over a wide range of vehicle and road conditions. A simulation study will be presented that evaluates the proposed scheme and compares the effectiveness of active front steer (AFS) and active rear steer (ARS) in enhancing the vehicle performance. Both time and frequency domain results are presented.

Hirche, Benjamin, Ayalew, Beshah

Implementation of Fuzzy Logic Control in Semiactive Suspension for a Vehicle Using MATLAB SIMULINK

2016-28-003502/01/2016

The design of the conventional passive suspension has always been a compromise between vehicle handling and comfort, which led to the development of the modern active and semi active suspension systems. Amongst these, semi-active suspension has been focus of research in recent years owing to its lesser complexity and less power consumption as compared to active suspension. Semi active suspension uses real time variation in damping coefficient which can be achieved by using various control strategies. It is observed from available literature that Skyhook (for better ride comfort), Groundhook (for better vehicle handling) and Hybrid are most widely used strategies. These strategies use ‘On-Off’ control strategy (i.e. two preset values of damping co-efficient) but a better control over damping coefficients can be achieved using Continuous Control strategy. This paper aims to implement Continuous control strategy using Fuzzy logic for the semi active suspension. For the analysis, Two

Rasal, Shraddhesh, Jaganmohan, Jayanth, Agashe, Sohan, Wani, Kiran P

Fuzzy Shared Semi-Autonomous Control System For Military Vehicles

2015-36-027009/22/2015

Semi-autonomous control systems applied to automobiles are Advanced Driver Assistance Systems (ADAS) that have gained importance from similar devices with applications in robotics. The control sharing between humans and automatic controllers is the main characteristic of these systems, and can be accomplished through various different manners. However, the use of Artificial Intelligence (AI) techniques for this purpose remains unexplored. In this paper we propose the design of a semi-autonomous control system applied to military vehicles through the use of Fuzzy Inference Systems for the definition of the controller intervention level. Simulations of a vehicle being operated in highly dangerous situations, represented by the existence of hostile military threats or by unexpected maneuvers that could put the stability of the car at risk were performed. The control system’s level of intervention during the simulations was observed, and we could realize the increase of this variable

Sá, Hebert Azevedo, Neto, Mauro Speranza, Meggiolaro, Marco Antonio, Ferreira, Armando Morado

Development of a Safety Assessment Tool for Air Traffic Control System

2015-01-244109/15/2015

This paper outlines an analytical framework to perform a data-driven, risk-based assessment of Air Traffic Control (ATC) facilities. Safety associated with an ATC facility is modeled as an influence network using a set of risk factors. A novel hybrid approach employing Adaptive-Network based Fuzzy Inference Systems is introduced to propagate the model. Statistical analysis of system-wide data for each risk factor is performed to identify outliers and understand underlying distributions. They are then used to define Fuzzy Membership Functions for model variables. Analytical Hierarch Process (AHP) is used to determine rules required by the model's inference engine. Finally, the methodology is applied to a set of ATC facilities using real data.

Oztekin, Ahmet

Comparative Study of ANN and ANFIS Prediction Models For Turning Process in Different Cooling and Lubricating Conditions

2015-01-908205/01/2015

The most efficient way to reduce friction and heat generation at the cutting zone is to use advanced cooling and lubricating techniques. In this paper, an experimental study was performed to investigate the capabilities of conventional, minimal quantity lubrication (MQL) and high pressure cooling (HPC) in the turning operations. Process parameters (feed, cutting speed and depth of cut) are used as inputs to the developed artificial neural network (ANN) and the adaptive networks based fuzzy inference systems (ANFIS) model for prediction of cutting forces, tool life and surface roughness. Results obtained by the models have been compared for their prediction capability with the experimentally determined values and very good agreement with experimental results was observed.

Sredanovic, Branislav, Cica, Djordje

Uncertainty Analysis of Static Plane Problems by Intervals

2015-01-048204/14/2015

We present a new interval-based formulation for the static analysis of plane stress/strain problems with uncertain parameters in load, material and geometry. We exploit the Interval Finite Element Method (IFEM) to model uncertainties in the system. Overestimation due to dependency among interval variables is reduced using a new decomposition strategy for the structural stiffness matrix and the nodal equivalent load vector. Primary and derived quantities follow from minimization of the total energy and they are solved simultaneously and with the same accuracy by means of Lagrangian multipliers. Two different element assembly strategies are introduced in the formulation: one is Element-by-Element, and the other resembles conventional assembly. In addition, we implement a new variant of the interval iterative enclosure method to obtain outer and inner solutions. Numerical examples show that the proposed interval approach guarantees to enclose the exact system response.

Xiao, Naijia, Muhanna, Rafi L., Fedele, Francesco, Mullen, Robert L.

Intelligent Traffic Lights Control System using Fuzzy Logic

2014-36-035909/30/2014

This paper describes the development of an Intelligent Traffic Lights Control System using Fuzzy Logic concepts. Fuzzy Logic offers the possibility to ‘compute with words’, by using a mechanism for representing linguistic constructs common on real world problems. This is very important when the complexity of a task (problem) exceeds a certain threshold. Real world complex problems such human controlled systems involve a certain degree of uncertainty, which cannot be handled by traditional binary set theory. The algorithm implementation will be done inside Mathworks MATLAB software, and the results will be measured on Simulink Tool to create traffic scenarios and comparisons between simple time-based algorithms and the proposed system. During Project phase, a Robustness Parameter-Diagram will be used to design the system and cover its variables, error states, possible noises and control factors. The Project also comprehends some research regarding the currently used algorithms

Pinto, Alessandro Cezar, Mattioli, Geovanni Vezzaro

Flight Path Reconstruction and Wind Estimation Using Flight Test Data from Crash Data Recorder (CDR)

2014-01-216809/16/2014

This paper presents the implementation of flight path reconstruction (FPR) and wind estimation techniques applied to a high performance fighter aircraft. The analysis is carried out for the flight test data gathered and stored in a Crash Data Recorder (CDR). The data signals obtained from CDR are generally highly noisy, with frequent data drop outs and also with low sampling rate. The estimation technique applied for data reconstruction is the extended Kalman filtering (EKF). The reconstructed trajectories can be compared with the actual flight trajectories such that, in case of unavailability of data from other sources (e.g., digital flight control computer), the algorithm should be able to reconstruct the trajectories with the minimum set of data available from the CDR. Wind estimation along with the trajectory reconstruction can give better accuracy in airspeed as well as flow angles. The algorithm also aims at determining the bias/systematic instrument errors and generating

Nusrath, Khadeeja, Sarmah, Ankur, Singh, Jatinder

Tethered Vehicle Control and Tracking System

TBMG-1991506/01/2014

This innovation can control the flight of a tethered vehicle, in an airborne wind energy (AWE) generation system, through the use of a pan-tilt platform and a visible spectrum digital camera, combined with tracking and control software running on a standard PC.

Identification of Abnormal Noise Temperature Patterns in Deep Space Network Antennas Using Fuzzy Logic

TBMG-1958605/01/2014

The communication between NASA space mission operations teams and their respective spacecraft in outer space is accomplished via the Deep Space Network (DSN). To ensure proper operations in returning telemetry data to mission operations, sending commands to spacecraft and providing radiometric data for navigation purposes, the DSN equipment generates a large set of self-monitor data. System noise temperature (SNT) and link margin are two of the key metrics of system performance for telemetry data return. The ability to detect the signal is affected by the SNT; the lower the noise, the better chance the system can detect the signal. Thus, there is a strong interest in monitoring and classifying the SNT. However, there are many causes of SNT behavior patterns that are still not known and difficult to classify by simple logic. There is a benefit to use a more sophisticated pattern-recognition method to detect and classify abnormal SNT behaviors.

Preview Enhanced Rule-Optimized Fuzzy Logic Damper Controller

2014-01-086804/01/2014

New developments in road profile measurement systems and in semi-active damper technology promote the application of preview control strategies to vehicle suspension systems. This paper details a new semi-active suspension control approach in which a rule-optimized Fuzzy Logic controller is enhanced through preview capability. The proposed approach utilizes an optimization process for obtaining the optimum membership functions and the optimum rule-base of the preview enhanced Fuzzy Logic controller. The preview enhanced Fuzzy Logic controller uses the feedforward road input information and the feedback vehicle state information as the controller inputs. An eleven degree of freedom full vehicle model, which is validated through laboratory tests performed on a hydraulic four-poster shaker, is used for the controller synthesis. The cost function including both ride comfort and road holding performance of the full vehicle is minimized through a discrete optimization process utilizing

Kaldas, Mina, Caliskan, Kemal, Henze, Roman, Küçükay, Ferit

Fuzzy Neuron: Method and Hardware Realization

TBMG-18908

01/01/2014

Simple and effective learning functions and adaptive elements can be placed into small hardware systems to include instruments for space, bioimplantable devices, and stochastic observers.