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Applications of Computational Intelligence Techniques in Engineering. B Samanta International Visiting Professor Robert Morris University. Presentation Summary. Motivation Computational Intelligence Different CI techniques Applications of CI techniques Recent Work Work done at RMU
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Applications of Computational Intelligence Techniques in Engineering B Samanta International Visiting Professor Robert Morris University RMU_Summer2005_Samanta
Presentation Summary • Motivation • Computational Intelligence • Different CI techniques • Applications of CI techniques • Recent Work • Work done at RMU • Way forward • Conclusions RMU_Summer2005_Samanta
Motivation • Use of computers for better understanding and interpretation of process/system behavior • Use of available information to obtain input-output mapping. • Utilization of expert/operator knowledge • Ability to use imprecise, uncertain information • Integration of knowledge over multiple disciplines • Automated machine learning inspired from nature (neuroscience, genetics, behavioral science) • Development of models for optimizing the system performance satisfying the inherent system/process constraints. RMU_Summer2005_Samanta
Computational Intelligence (CI) • Intelligence built in computer programs • Covers • Evolutionary computing • Fuzzy computing • Neuro-computing • Also known as • Soft computing RMU_Summer2005_Samanta
CI Techniques • Artificial Intelligence (AI) • Artificial Neural Networks (ANNs) • Fuzzy Logic (FL) • Support Vector Machines (SVM) • Self Organizing Maps (SOM)- unsupervised • Genetic Algorithm (GA) • Genetic Programming (GP) • Swarm Intelligence/Particle Swarm Optimization (PSO) RMU_Summer2005_Samanta
CI Techniques (contd.) • ANNs • Multi-layer Perceptron (MLP) • Radial Basis Function (RBF) • Probabilistic Neural Network (PNN) • Fuzzy Logic + ANN • Adaptive neuro-fuzzy inference system (ANFIS) RMU_Summer2005_Samanta
CI Techniques (contd.) ANN structure • Input layer • Hidden Layer (s) • Output layer • Number of nodes in each layer • Functions and their parameters Mostly decided on trial and error basis RMU_Summer2005_Samanta
ANN- a typical example Input layer Hidden layer x1 u1 y1 u2 y2 x2 . . . . . . uQ xN yM RMU_Summer2005_Samanta
Fuzzy Logic Steps involved • Fuzzification using membership functions (MFs)-input • Generation of rule base • Aggregation • Defuzzification using MFs -output RMU_Summer2005_Samanta
Fuzzy Logic (contd.) • Input and output MFs • Number • Type • Parameters • Rule base (experience guided) RMU_Summer2005_Samanta
Neuro-Fuzzy System • Combines the advantages of fuzzy logic (FL) and ANNs • Starts with an initial FL structure • Uses ANN for adapting the FL (MF) parameters and the rule base to the training data RMU_Summer2005_Samanta
Fuzzy Logic – An Example ANFIS structure for an example system with 2 inputs and 1 output. RMU_Summer2005_Samanta
Snapshot of rule base for an example system with 2 inputs and 1 output. RMU_Summer2005_Samanta
Genetic Algorithms • Construction of genome (individual) • Generation of initial population (group of individuals) • Evaluation of individuals • Selection of individuals based on criteria • Generation of new individuals • Mutation • Crossover • Repetition of the process - generation, evaluation, selection • Termination of the process based on max generation no. and/or performance criteria RMU_Summer2005_Samanta
Combinations • Combine advantages of GA and other classifiers • GA and ANN • GA and ANFIS • GA and SVM • for automatic selection of classifier structure and parameters • ANNs -Number of neurons in hidden layer • ANFIS - Number of MFs and their parameters • SVM – SVM parameters • Selection of most important system features from a pool • Selection of most important sensors (in the context of on-line condition monitoring and diagnostics)- sensor fusion. RMU_Summer2005_Samanta
Rotating Machine with Sensors Signal Conditioning and Data Acquisition Feature Extraction Training Data Set Test Data Set GA based selection of features and parameters Training of ANN/ SVM No No Is ANN/ SVM Training Complete ? Yes Is GA based selection over? Yes Trained ANN/ SVM with selected features ANN / SVM Output Machine Condition Diagnosis RMU_Summer2005_Samanta Fig. 1. Flow chart of diagnostic procedure
Genetic Programming (GP) • GP – a branch of GA with a lot of similarities. • Main difference of GP and GA is in the representation of the solution. • In GA, the output is in form of a string of numbers representing the solution. • GP produces a computer program in form of a tree-based structure relating • the inputs (leaves) • the mathematical functions (nodes) and • the output (root node). RMU_Summer2005_Samanta
(+ (* (X1 X2))(exp(3)) plus exp times X1 X2 3 GP output –An Example • Terminals (leaves): inputs x1, x2 and constant 3 • Nodes: Math functions *,+, exp • Output: x1*x2+exp(3) RMU_Summer2005_Samanta
Applications • Computer Science • Pattern Recognition (PR) • Data Mining • Knowledge Discovery/ Machine Learning • Feature Extraction and Selection • Mechanical Systems • Condition monitoring and diagnostics • Multiobjective optimization in design • Control System Design • Manufacturing Systems • Development of data-driven models • Multiobjective optimization of machining parameters RMU_Summer2005_Samanta
Applications (contd.) • Engineering Management/IE • Inventory management • Project selection • Facility layout design • Scheduling • Medicine • Patient condition monitoring and diagnosis • Social Science • Business • Market analysis and forecasting • Credit rating RMU_Summer2005_Samanta
Recent Work • Machine Condition Monitoring and Diagnostics using • ANNs-MLP, RBF, PNN • SVM • ANFIS • GA-ANN • GA-ANFIS • GA-SVM • GP • Involving signal processing, feature extraction, selection and sensor fusion RMU_Summer2005_Samanta
Recent work (contd.) • Materials • ANN based estimation of fatigue life • Modeling of material properties in terms of heat treatment parameters • Rotordynamics • Control System Design RMU_Summer2005_Samanta
Work done at RMU • Intelligent Manufacturing Systems • Development of Tool Wear Model • ANFIS and GA-ANFIS • Genetic Programming (GP) • Development of machined surface roughness model • ANFIS and GA • Genetic Programming (GP) • Mutliobjective optimization of machining parameters • Minimization of machining cost • Minimization of surface roughness • Minimization of production time • Subject to constraints on • Operating parameters –speed, feed, depth of cut • Cutting Force • Power consumption • Tested on 5 different data sets • Involves different machining operations • Milling, • turning and • Turning of hard material (>Rc 65) RMU_Summer2005_Samanta
Tool Wear Model • Mapping of Inputs and Outputs • Inputs • Tool type- geometry, material • Work piece • Cutting speed (V) • Feed rate (f) • Depth of cut (d) • Vibration (Vx, Vy, Vz) • Forces (Fx, Fy, Fz) • Cutting Time (t) • Outputs • Tool wear • Remaining Tool Life • GA/GP based selection of characteristic inputs RMU_Summer2005_Samanta
ANFIS based Tool Wear Model – An Example • Input pool • Spindle speed (x1) • Feed rate (x2) • Machining time (x3) • Ratio of forces in 2 directions: Fx (feed)/ Fz (tangential) (x4) • Output – Tool wear level • Data set • Training – 25 • Test - 38 • Number of MFs - 2 • Performance – • Training Root Mean Square Error (RMSE) 1.30% • Test data set RMSE : 8.52% • Training time 0.34 s RMU_Summer2005_Samanta
GA-ANFIS based roughness model – An Example • Input pool • Spindle speed (x1) • Feed rate (x2) • Depth of cut (x3) • Vibration in 3 directions • x (radial) (x4) • y (tangential) (x5) • z (feed) (x6) • Output – surface roughness • Data set • Training – 36 • Test - 24 • GA based selection of best 3 features: x2, x1, x5 • Number of optimum MFs - 2 • Performance – • Training Root Mean Square Error (RMSE) 2.60% • Test data set RMSE : 6.65% • Training time 263.2 s RMU_Summer2005_Samanta
GP model for surface roughness • GP was used for same data sets • Training – 36 • Test set – 24 • Performance • Training RMSE: 3.79% • Test RMSE : 6.90% • Training time: 463.7 s RMU_Summer2005_Samanta
GP output tree for Roughness model RMU_Summer2005_Samanta
Publications Planned • Predictive modeling of tool wear in turning using adaptive neuro-fuzzy inference system • Modeling and prediction of tool wear in turning using genetic programming • Predictive modeling of surface roughness in turning using adaptive neuro-fuzzy inference system and genetic algorithms RMU_Summer2005_Samanta
Publications Planned (contd.) • Modeling and prediction of surface roughness in turning using genetic programming • Predictive modeling of surface roughness in milling using adaptive neuro-fuzzy inference system and genetic algorithms • Multiobjective evolutionary optimization of a machining process RMU_Summer2005_Samanta
Conferences/Journals • North American Manufacturing Research Conference (NAMRC 34 ), NAMRI/SME, May 23-26, 2006, Milawukee, WI, USA. • Flexible Automation and Intelligent Manufacturing (FAIM) June 26-28, 2006, Univ of Limerick, Ireland. • IFAC Symposium on Information Control in Manufacturing (INCOM) May17-19, 2006, France. • Journal of Manufacturing Systems/SME • International Journal of Machine Tools & Manufacture RMU_Summer2005_Samanta
Industry-RMU collaboration Potential • Interest in RMU-EOC research collaboration in the area of Laser machining. • Development of machining models using CI • Multiobjective constrained optimization of machining/laser system parameters • Sensor fusion • Interest in RMU-ExOne research collaboration in the areas of 3D printing • process • system • Design optimization RMU_Summer2005_Samanta
Way Forward • Scope for further collaboration with RMU • Teaching – Development of new elective or short courses in consultation with Faculty • Research – Joint supervision of projects/theses at Senior, MS and PhD levels • Collaborative work with Faculty • Outreach- Industry and Government supported research projects/contracts RMU_Summer2005_Samanta
Conclusions Increasing popularity of CI techniques • Integrating capability over multiple disciplines • Capability of incorporating imprecision and uncertainty • Suitability for hard-to-model processes /systems • Better alternatives to traditional hard computing scenario RMU_Summer2005_Samanta
THANKS Thanks to • RMU Administration • Sponsor of the Program • SEMS/Engineering Faculty, Staff for the support and facilitating the visit Thanks to you all (in audience) • For your time and patience RMU_Summer2005_Samanta