Adaptive Control System for Optimizing the ECG Process under the Overcut Constraint
One of the main limitations 1n Peripheral Electro Chemical Grinding (ECG) is the overcut phenomenon. The dominant parameters which govern the dimensions of the geometrical overcut are the voltage and the feedrate. This paper deals with the development of an empirical model which describes the overcut as a function of the dominant parameters. Pased on this model an adpative control system was built and experiments in Profile Peripheral ECG were carried out. A comparison of the results obtained with and without the adaptive control system is presented as well as the relationship between the side and bottom overcuts. According to the above an adaptive strategy to control the geometrical overcut in Profile ECG is suggested.
MODELING OF ELECTROCHEMICAL GRINDING PROCESS A THESIS SUBMITTED FOR PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE AWARD OF THE DEGREE OF MASTER OF SCIENCE IN MECHANICAL ENGINEERING
Electrochemical Grinding (ECG) process is a mechanically assisted electro-chemical process for material processing. The process is able to successfully machine electrically conducting harder materials at faster rate with improved surface finish and dimensional control. The process generates burr-free, stress free surface, unlike mechanical grinding at a lower cost of production. The material removal mechanism and the parametric effects of different process parameters on material removal rate have extensively been analysed. The interrelationship amongst the process parameters has been established. The thesis includes the development of mathematical modeling for metal removal rate (MRR) in ECG process. The relative contribution of electrochernical dissolution and mechanical action to overall material removal rate has been evaluated. An experimental set-up has also been designed for electrochemical grinding process.
Robust solutions of inverse problems in electromagnetic non-destructive evaluation
Non-destructive testing (NDT) is the application of physical measurement technology based on energy interaction with the material and its nonconformities. The material's response is sensed by transducers and sensors which?in most cases?scan the component and document the results in inspection images. However, NDT measures a physically defined quantity or even an intrinsic property. The difference between non-destructive evaluation (NDE) and NDT is in the interpretation of the inspection data. NDE has to discuss the inspection results in terms of quality elements and characteristics which are relevant to describe the fitness of the material for use. In the case of macroscopic defects these are the kind of defect (cracklike, globular) and its size and orientation to the main stress directions; in the case of material property determination the parameters are mainly mechanical properties. Therefore, in NDE one has to solve inverse problems. The solution of inverse problems based on mathematical procedures such as integral equations is a strong developing discipline and most of the articles prepared for this special issue of the journal have the objective of discussing the latest state of the art in that field. However, practical NDE needs robust and quick solutions which are to be applied mainly online. Therefore, we present here inversion procedures based on multiple linear regression algorithms applied to inspection data. We describe the calibration procedure to fit the free parameters of the model functions and give examples of practical applications in industry.