scholarly journals A Dedicated Design Strategy for Active Boring Bar

2019 ◽  
Vol 9 (17) ◽  
pp. 3541 ◽  
Author(s):  
Niccolò Grossi ◽  
Lisa Croppi ◽  
Antonio Scippa ◽  
Gianni Campatelli
Keyword(s):  
Operating Conditions ◽  
Dynamic Characterization ◽  
Control Logic ◽  
Boring Bar ◽  
Actuation System ◽  
Static Equivalence ◽  
And Control ◽  
Cutting System ◽  
Damping Systems ◽  
Critical Aspects

Unstable vibrations (i.e., chatter) onset is one of the main limits to productivity in deep boring bar processes. Active damping systems allow to increase machining stability in different configurations (i.e., tool setup), without requiring cutting system dynamic characterization. Design of an active boring bar involves the development of monitoring system (sensors), actuation system and control logic. While several control logics were evaluated and discussed, few design solutions were presented in the literature, focusing only on building prototypes to demonstrate control logic effectiveness. In the presented work, a deep analysis of the main issues and requirements related to active boring design was carried out and a systematic approach to tackle all the critical aspects was developed. The results of the proposed method are: (i) optimal actuators positioning able to damp vibration along two directions; (ii) preload system design guaranteeing the correct actuator preloading for the operating conditions; (iii) covers design to protect actuators and ensure the dynamic and static equivalence between active and standard boring bar. Following this approach, an active boring bar was designed, realized and tested. The results prove the required equivalence between active and original boring bar and assess the damping effect.

From Research to Didactics: The Course of Dynamics and Control of Fluid Machines for Automation Engineering Students

2008 ◽  
Author(s):  
M. Venturini ◽  
M. Morini
Keyword(s):  
Dynamic Behavior ◽  
Engineering Students ◽  
Student Evaluation ◽  
Operating Conditions ◽  
Student Feedback ◽  
System Control ◽  
Control Logic ◽  
Dynamics And Control ◽  
The University ◽  
And Control

The paper deals with the course “Dynamics and Control of Fluid Machines”, which has been held at the Faculty of Engineering of the University of Ferrara (Italy) since the academic year 2002/2003 for the Second-Level Degree Course in Computer Sciences and Automation Engineering. The aim of the course is the study of fluid machines, by combining base knowledge with physical-mathematical analysis of the unsteady behavior and of off-design operating conditions. The first characteristic aspect of the course is the study of the dynamic behavior of fluid machines. The second relevant aspect is the analysis of system control. In this paper, course characteristics are presented and discussed. In particular, as a part of the final examination, students are asked to develop an individual project, whose results are also reported in this paper. The project consists of the simulation of the dynamic behavior of an industrial system for compressed air production by means of a multistage centrifugal compressor. Students are required to properly design the controller and to discuss the adopted control logic. Student feedback is evaluated by means of a survey conducted to evaluate the quality of the didactic activity. The analysis of student feedback reveals that student evaluation towards the course proves higher than the “average” evaluation for the didactic activity held at the University of Ferrara, at the Faculty of Engineering or within the same Degree Course.

scholarly journals Neoteric Fuzzy control stratagem and design of Chopper fed Multilevel Inverter for enhanced Voltage Output involving Plug-In Electric Vehicle (PEV) applications

Electronics ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1092 ◽  
Author(s):  
Sunddararaj ◽  
Rangarajan ◽  
Gopalan
Keyword(s):  
Electric Vehicle ◽  
New Technologies ◽  
Control Strategies ◽  
Economic Benefits ◽  
Multilevel Inverter ◽  
Control Logic ◽  
Bidirectional Converters ◽  
Hybrid Controller ◽  
And Control ◽  
Novel Design

The utilization of plug-in electric vehicles (PEV) has started to garner more attention worldwide considering the environmental and economic benefits. This has led to the invention of new technologies and motifs associated with batteries, bidirectional converters and inverters for Electric Vehicle applications. In this paper, a novel design and control of chopper circuit is proposed and configured with the series and parallel connection of the power electronic based switches for two-way operation of the converter. The bidirectional action of the proposed converter makes it suitable for plug-in electric vehicle applications as the grid is becoming smarter. The DC–DC converter is further interfaced with the designed multilevel inverter (MLI). The reduced switches associated with the novel design of MLI have overcome the cons associated with the conventional inverters in terms of enhanced performance in the proposed design. Further, novel control strategies have been proposed for the DC–DC converter based on Proportional Integral (PI) and Fuzzy based control logic. For the first time, the performance of the entire system is evaluated based on the comparison of proposed PI, fuzzy, and hybrid controllers. New rules have been formulated for the Fuzzy based controllers that are associated with the Converter design. This has further facilitated the interface of bidirectional DC–DC converter with the proposed MLI for an enhanced output voltage. The results indicate that the proposed hybrid controller provides better performance in terms of voltage gain, ripple, efficiency and overall aspects of power quality that forms the crux for PEV applications. The novelty of the design and control of the overall topology has been manifested based on simulation using MATLAB/SIMULINK.

LSI Microcomputer and Digital Control

1975 ◽  
Vol 97 (2) ◽  
pp. 149-156 ◽  
Author(s):  
I. Lee
Keyword(s):  
Digital Control ◽  
Historical Background ◽  
Control System Design ◽  
Future Trends ◽  
Digital Control System ◽  
Control Logic ◽  
Present Trend ◽  
Potential Impact ◽  
Microprocessor Technology ◽  
And Control

This paper gives a tutorial presentation and overview of LSI microprocessor technology for control engineers and control logic designers. The historical background, present status and future trends of this dynamic technology are presented, and its enormous potential impact on digital control system design and implementation is explored through examples and extrapolation of the present trend.

Overview of Path-Planning and Obstacle Avoidance Algorithms for UAVs: A Comparative Study

2018 ◽  
Vol 06 (02) ◽  
pp. 95-118 ◽  
Author(s):  
Mohammadreza Radmanesh ◽  
Manish Kumar ◽  
Paul H. Guentert ◽  
Mohammad Sarim
Keyword(s):  
Path Planning ◽  
Comparative Study ◽  
Operating Conditions ◽  
Computational Time ◽  
Safe Operation ◽  
Sense And Avoid ◽  
Planning Algorithms ◽  
And Control ◽  
Global And Local ◽  
Further Development

Unmanned aerial vehicles (UAVs) have recently attracted the attention of researchers due to their numerous potential civilian applications. However, current robot navigation technologies need further development for efficient application to various scenarios. One key issue is the “Sense and Avoid” capability, currently of immense interest to researchers. Such a capability is required for safe operation of UAVs in civilian domain. For autonomous decision making and control of UAVs, several path-planning and navigation algorithms have been proposed. This is a challenging task to be carried out in a 3D environment, especially while accounting for sensor noise, uncertainties in operating conditions, and real-time applicability. Heuristic and non-heuristic or exact techniques are the two solution methodologies that categorize path-planning algorithms. The aim of this paper is to carry out a comprehensive and comparative study of existing UAV path-planning algorithms for both methods. Three different obstacle scenarios test the performance of each algorithm. We have compared the computational time and solution optimality, and tested each algorithm with variations in the availability of global and local obstacle information.

Experimental Investigation on the Rubbing Process of Labyrinth Seals Considering the Material Combination

2020 ◽  
Author(s):  
Lisa Hühn ◽  
Oliver Munz ◽  
Corina Schwitzke ◽  
Hans-Jörg Bauer
Keyword(s):  
Turbine Blades ◽  
Design Guidelines ◽  
Operating Conditions ◽  
Contact Forces ◽  
Experimental Investigations ◽  
Process Data ◽  
Labyrinth Seals ◽  
Material Combination ◽  
Higher Temperature ◽  
And Control

Abstract Labyrinth seals are used to prevent and control the mass flow rate between rotating components. Due to thermally and mechanically induced expansions during operation and transient flight maneuvers, a contact, the so-called rubbing process, between rotor and stator cannot be excluded. A large amount of rubbing process data concerning numerical and experimental investigations is available in public literature as well as at the Institute of Thermal Turbomachinery (ITS). The investigations were carried out for different operating conditions, material combinations, and component geometries. In combination with the experiments presented in this paper, the effects of the different variables on load due to rubbing are compared, and discussed with the focus lying on the material combination. The influence of the material on the loads can be identified as detailed as never before. For example, the contact forces in the current experiments are higher due to a higher temperature resistance of Young’s modulus. The analysis will also be based on the rubbing of turbine blades. Design guidelines are derived for labyrinth seals with improved properties regarding tolerance of rub events. Based on the knowledge obtained, guidelines for designing reliable labyrinth seals for future engines are discussed.

Synergetic Concept of Software Control of Machining Processes on Metal-Cutting Machines

2021 ◽  
pp. 24-36
Author(s):  
V.L. Zakovorotny ◽  
V.E. Gvindzhiliya
Keyword(s):  
Tool Wear ◽  
Metal Cutting ◽  
Wear Testing ◽  
External Control ◽  
Machining Processes ◽  
Cutting Zone ◽  
Output Characteristics ◽  
The Cost ◽  
And Control ◽  
Cutting System

High precision metal-cutting machines ensure that the programmed machine actuator trajectories correspond to the real ones. For lathes these are the trajectories of the longitudinal and transverse calipers of the system, as well as the spindle. The purpose of processing is to produce parts of a given quality while minimizing the manufacturing costs. The condition of the dynamic cutting system, determined by the trajectories of forces and deformations, affects the quality indicators of parts and the cutting efficiency, which depends on the intensity of tool wear. The properties of the system change depending on the phase trajectory of the power of irreversible transformations of the energy supplied to the cutting zone by the work performed. Their changes related with the evolution of the parameters of the dynamic link formed by cutting are manifested in the development of tool wear and changes in the quality of the part. Thus, the power of irreversible energy transformations is one of the internal factors causing changes in the output characteristics of processing and the state of the process. In this regard, when processing on machine tools, there is a problem of synergistic coordination of external control (for example, the CNC program) with internal one, the source of which is the irreversible transformation of the energy supplied to the cutting zone. The article considers the problem of synergetic coordination of external and internal controls during cutting process, the solution of which will allow increasing the efficiency of processing on CNC machines. A mathematical model of a controlled dynamic cutting system and control algorithms are proposed to improve the efficiency of processing parts of a given quality while minimizing the intensity of tool wear. Testing of the developed algorithms has shown that their use reduces the cost of manufacturing parts by 1.2.

Sign in / Sign up

Export Citation Format

Share Document