Control of Machine Tools

1997 ◽  
Vol 119 (4B) ◽  
pp. 749-755 ◽  
Author(s):  
Yoram Koren
Keyword(s):  
Adaptive Control ◽  
Machine Tool ◽  
Real Time ◽  
System Performance ◽  
Machine Tools ◽  
Experimental Results ◽  
The Individual ◽  
Selection Of

This paper reviews the progress in machine tool control during the last three decades. Three types of controls are discussed: (i) Servocontrol loops that control the individual axes of the machine, (ii) interpolators that coordinate the motion of several axes, and (iii) adaptive control that adjusts the cutting variables in real time to maximize system performance. We cover a selection of the most advanced techniques utilized in each of these types, and draw conclusions based on experimental results.

Computerized Selection of Optimum Machining Conditions for a Job Requiring Multiple Operations

1978 ◽  
Vol 100 (3) ◽  
pp. 356-362 ◽  
Author(s):  
S. S. Rao ◽  
S. K. Hati
Keyword(s):  
Nonlinear Programming ◽  
Mathematical Programming ◽  
Machine Tools ◽  
Machining Conditions ◽  
Coupling Constraints ◽  
Programming Techniques ◽  
Mathematical Programming Problems ◽  
The Individual ◽  
The Cost ◽  
Selection Of

The problem of determining the optimum machining conditions for a job requiring multiple operations has been investigated. Three objectives, namely, the minimization of the cost of production per piece, the maximization of the production rate and, the maximization of the profit are considered in this work. In addition to the usual constraints that arise from the individual machine tools, some coupling constraints have been included in the formulation. The problems are formulated as standard mathematical programming problems, and nonlinear programming techniques are used to solve the problems.

scholarly journals Use of Artificial Intelligence for Face Detection with Face Mask in Real Time to Control the Entrance to an Entity

2021 ◽  
Vol 11 (11) ◽  
pp. 68-75
Author(s):  
Enrique Lee Huamaní ◽  
◽  
Lilian Ocares Cunyarachi
Keyword(s):  
Machine Learning ◽  
Real Time ◽  
Face Detection ◽  
Face Mask ◽  
Economic Activities ◽  
Facial Mask ◽  
The Face ◽  
The Individual ◽  
A Company ◽  
Selection Of

Due to the pandemic caused by Covid-19, daily life has changed significantly. For this reason, biosecurity measures have been implemented to prevent the spread of the virus as an effective way to reactivate economic activities. In this sense, the present paper focuses on real-time face detection as a measure of control at the entrance to an entity, thus avoiding the spread of the virus while recognizing the identity of workers despite the use of masks and thus reducing the risk of entry of individuals outside the organization. Therefore, the objective is to contribute to the security of a company through the application of machine learning methodology. The selection of methodology is justified due to the adaptation of the same according to the interests of this project. Consequently, algorithms were used in a progressive manner, obtaining as a result the control system that was intended, since each particularity of the face of the individual was recognized in relation to its corresponding identification. Finally, the results of this article benefit the security of organizations regardless of their field or sector. Keywords— Control, Detection, Facial Recognition, Facial Mask, Face recognition, Machine learning.

Controlling Nylon Dyeing by Dye and Chemical Metering

1997 ◽  
Vol 67 (8) ◽  
pp. 609-616 ◽  
Author(s):  
Ralph McGregor ◽  
Manpreet S. Arora ◽  
Warren J. Jasper
Keyword(s):  
Adaptive Control ◽  
Binary Mixture ◽  
Real Time ◽  
Closed Loop ◽  
Closed Loop Control ◽  
Good Reproducibility ◽  
Acid Dyes ◽  
Loop Control ◽  
Polyamide Fibers ◽  
The Individual

Closed-loop control of the dosing of dyes and chemicals is used to obtain an on-tone build-up of shade in dyeing polyamide fibers with a binary mixture of monosulfonated acid dyes. Computerized dosing pumps control the pH, the dyebath concentrations of the individual dyes, and the total sorption of each dye during the process. This real-time, closed-loop adaptive control yields good reproducibility and uniform shade build-up in a laboratory dyeing machine. It is possible to reuse a dyebath containing residual dyes and chemicals from a previous dyeing.

Experimental Research Regarding the Influence of Hydraulic Resistances on the Hydrostatic Guideways Stiffness

2014 ◽  
Vol 657 ◽  
pp. 475-479
Author(s):  
Marius Pascu ◽  
Gheorghe Stan
Keyword(s):  
Machine Tool ◽  
Hydraulic Resistance ◽  
Experimental Research ◽  
Machine Tools ◽  
Dynamic Stiffness ◽  
Experimental Results ◽  
Graphical Form ◽  
Experimental Setup ◽  
Experimental Database ◽  
Supply Circuit

A very important factor for the hydrostatic guideways is given by the presence of the restrictor on the supply circuit, whose hydraulic resistance may have important effects on the lubricant film behaviour and implicitly, on the static and dynamic stiffness of the system. This paper presents a new method of experimental research regarding the hydrostatic guideway stiffness, depending on the hydraulic resistances values which supply each pocket. During the experiments which approach the influence of the hydraulic resistances values of the restrictors on the hydrostatic guideway stiffness, a centered constant loads of 20, 50 and 100 [daN] was used. The experiments were carried out on an experimental setup composed of an open hydrostatic guideway, having the pocket dimensions of 150x88 [m, supplied with liquid under pressure through means of a pack of adjustable restrictors. The obtained experimental results are presented in both tabular and graphical form and constitute an experimental database which can be used by the machine tools designers and manufacturers. The paper contains recommendations regarding the usage of hydraulic resistances values depending on the machine tool type and size. Also, from the obtained results, recommendations can be made with regard to the type of restrictors to be used, so that the lubricant filtration grade is comprised between admissible values.

Use of Shock Compared With Harmonic Excitation in Machine Tool Structure Analysis

1974 ◽  
Vol 96 (1) ◽  
pp. 187-195 ◽  
Author(s):  
J. Tlusty ◽  
K. C. Lau ◽  
K. Parthiban
Keyword(s):  
Machine Tool ◽  
Structure Analysis ◽  
Machine Tools ◽  
Harmonic Excitation ◽  
Mode Shapes ◽  
Shock Excitation ◽  
Machine Tool Structure ◽  
Degree Of Stability ◽  
The Individual

The paper recapitulates the method of analyzing stability against chatter of machine tools as it has been practised by one of the authors for many years. Several new features of the method are presented and, mainly, comments are given on the use of shock excitation for determining both the receptances of the structure and its mode shapes. The method itself consists of comparing results of cutting tests and of excitation tests for various directional orientations of the cut in the structure and of identifying the contribution of the individual modes to the resulting degree of stability.

INTEGRATION OF REAL-TIME CONTROL SIMULATION TO A VIRTUAL MANUFACTURING ENVIRONMENT

2002 ◽  
Vol 01 (01) ◽  
pp. 67-87 ◽  
Author(s):  
BYUNG-KWON MIN ◽  
ZHENGDONG HUANG ◽  
ZBIGNIEW J. PASEK ◽  
DEREK YIP-HOI ◽  
FORBES HUSTED ◽  
...  
Keyword(s):  
Machine Tool ◽  
Real Time ◽  
Machine Tools ◽  
Manufacturing Systems ◽  
Early Stage ◽  
Virtual Manufacturing ◽  
System Level ◽  
Manufacturing Environment ◽  
Manufacturing Environments ◽  
Virtual Manufacturing Environment

This paper presents a new integrated approach for simulation developed to improve the accuracy of virtual manufacturing environments. While machine tool simulation and virtual manufacturing for factory simulation have been frequently used in early stage plant development, each of these technique has been researched and implemented separately. This paper focuses on the utilization of real-time simulation of machine tools or active axes in manufacturing systems and integration of this simulation capability with virtual manufacturing environments. Machine-level simulation results are generated in real-time with a real machine tool controller and are fed to a virtual manufacturing environment. To integrate these two simulation techniques, system-level software is utilized as a communication platform. This system-level software was originally developed to control and configure whole manufacturing systems. The method has been successfully implemented within a testbed with full-scale machine tools. The results demonstrate that the proposed method advances the virtual manufacturing environments toward improved accuracy of factory level simulation, reduced effort for modeling and expanded functionality of machine-level simulations.

scholarly journals A Pediatric Knee Exoskeleton With Real-Time Adaptive Control for Overground Walking in Ambulatory Individuals With Cerebral Palsy

2021 ◽  
Vol 8 ◽  
Author(s):  
Ji Chen ◽  
Jon Hochstein ◽  
Christina Kim ◽  
Luke Tucker ◽  
Lauren E. Hammel ◽  
...  
Keyword(s):  
Cerebral Palsy ◽  
Adaptive Control ◽  
Control System ◽  
Real Time ◽  
System Performance ◽  
Zero Mode ◽  
Gait Training ◽  
Knee Extension ◽  
Overground Walking ◽  
Pediatric Knee

Gait training via a wearable device in children with cerebral palsy (CP) offers the potential to increase therapy dosage and intensity compared to current approaches. Here, we report the design and characterization of a pediatric knee exoskeleton (P.REX) with a microcontroller based multi-layered closed loop control system to provide individualized control capability. Exoskeleton performance was evaluated through benchtop and human subject testing. Step response tests show the averaged 90% rise was 26 ± 0.2 ms for 5 Nm, 22 ± 0.2 ms for 10 Nm, 32 ± 0.4 ms for 15 Nm. Torque bandwidth of P.REX was 12 Hz and output impedance was less than 1.8 Nm with control on (Zero mode). Three different control strategies can be deployed to apply assistance to knee extension: state-based assistance, impedance-based trajectory tracking, and real-time adaptive control. One participant with typical development (TD) and one participant with crouch gait from CP were recruited to evaluate P.REX in overground walking tests. Data from the participant with TD were used to validate control system performance. Kinematic and kinetic data were collected by motion capture and compared to exoskeleton on-board sensors to evaluate control system performance with results demonstrating that the control system functioned as intended. The data from the participant with CP are part of a larger ongoing study. Results for this participant compare walking with P.REX in two control modes: a state-based approach that provided constant knee extension assistance during early stance, mid-stance and late swing (Est+Mst+Lsw mode) and an Adaptive mode providing knee extension assistance proportional to estimated knee moment during stance. Both were well tolerated and significantly improved knee extension compared to walking without extension assistance (Zero mode). There was less reduction in gait speed during use of the adaptive controller, suggesting that it may be more intuitive than state-based constant assistance for this individual. Future work will investigate the effects of exoskeleton assistance during overground gait training in children with neurological disorders and will aim to identify the optimal individualized control strategy for exoskeleton prescription.

Development of Innovative Intelligent Machine Tool Based on CAM-CNC Integration Concept – Adaptive Control Based on Predicted Cutting Force –

2019 ◽  
Vol 13 (3) ◽  
pp. 373-381
Author(s):  
Isamu Nishida ◽  
Ryo Tsuyama ◽  
Keiichi Shirase ◽  
Masahiro Onishi ◽  
Katsuyuki Koarashi ◽  
...  
Keyword(s):  
Adaptive Control ◽  
Machine Tool ◽  
Cutting Force ◽  
Real Time ◽  
Machining Efficiency ◽  
Intelligent Machine ◽  
Computer Aided ◽  
Machine Control ◽  
Digital Copy ◽  
Copy Milling

A new methodology to generate instruction commands for prompt machine control as a replacement for the previously prepared numerical control (NC) programs is developed to realize an innovative intelligent machine tool. This machine tool can eliminate NC program preparation, achieve cutting process control, reduce the production lead time, and realize an autonomous distributed factory. In this study, the innovative intelligent machine tool based on the computer-aided manufacturing-computer NC integrated concept is developed. The special feature of this system is to generate instruction commands in real time for prompt machine control instead of using NC programs. Digital Copy Milling, which is a digitized version of traditional copy milling, is realized by using only the computer-aided design model of the product. In this system, the cutting-force simulation is performed simultaneously with the real-time tool path generation. Then, the tool feed rate can be controlled according to the predicted cutting force. Therefore, both the improvement of the machining efficiency and the avoidance of machining problems can be achieved. The instantaneous cutting force model predicts the cutting force. In this system, the work material is represented by the voxel model, and the uncut chip thickness is calculated discretely from the number of voxels removed. Thus, it is possible to predict the cutting force in the case of non-uniform contact between the tool and the work material. In this study, a machining simulation is conducted to validate the proposed method. The results of the simulation show successful tool feed speed adaptation based on the predicted cutting force. The results also show the effective reduction of the machining time. A case study of a custom-made product for dental prosthetics is examined as a good application of both the proposed adaptive control and the Digital Copy Milling system. Through this method, it is possible to improve the machining efficiency and prevent tool breakage.

scholarly journals Selection of numerical compensation model of geometric errors of machine tools

Mechanik ◽  
2018 ◽  
Vol 91 (11) ◽  
pp. 980-983
Author(s):  
Paweł Majda ◽  
Joanna Jastrzębska
Keyword(s):  
Machine Tool ◽  
Experimental Test ◽  
Machine Tools ◽  
Geometric Errors ◽  
Test Program ◽  
Volumetric Error ◽  
Technical Report ◽  
Measuring Machine ◽  
Intensive Work ◽  
Selection Of

After many years of intensive work, experts from ISO TC 39 have published the technical report ISO TR 16907 “Machine tools – numerical compensation of geometric errors”. This document defines the terminology, presents advantages and limitations of numerical compensation of machine tool and measuring machine. This gives machine manufacturers and users important information on the application of numerical compensation. In the context of the compensation types defined in ISO TR 16907, presented principles of selecting volumetric error models for three-axis machine tools. The principles of reducing these models due to the functional tasks of machine tools were also presented. The final result is a table of reduced models for three-axis machine tools. It determines the degree of the model and the experimental test program, which should be done to determine volumetric error.

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