Evaluation of dynamic quality of lathe machines to categorise them for better productivity and accuracy reducing defects

In this article the causes of elastic deformations of the MFTW (machine tools, jig-fixture, cutting tool and workpiece) system and their influence on diameter obtained after turning operations using lathe machines have been investigated. The major contributing causes on this issue, such as machine tool spindle bearing elastic system, radial deformation of spindle shaft as well as the deformation of workpiece, the influence of cutting forces and the drive system dynamics, elastic deformation of the machine tools components and more other causes are identified. An attempt has been made to model the nature of influences of the above mentioned causes in an example of lathe machines. Also a simple methodology for categorising lathes in a machine shop depending upon their level of accuracies of machined products is briefly proposed. This methodology may be useful for machine shop supervisors and process design engineers to reduce the rate of machining defects for a shop floor yielding higher productivity. This work may perfectly suit the activities of manufacturing engineers handling shop floor scheduling

The development of a mechatronics design course

The paper is devoted to the development and teaching of Mechatronics Design at tertiary level as part of Mechatronic Engineering degrees. General notion about the subject is focused on ideas of uniqueness of intelligent machines and the course curriculum of Mechatronics Design. A general course lay out and proposed subject contents are briefly explained. Mechatronics Design is a core subject dealing with design, development, and manufacturing, as well as, exploring of intelligent machines/systems with high-level hierarchies of intelligence. These intelligent machines or systems are capable of making decision, activating tasks, and carrying responsibilities for the consequences of these actions. Therefore, the contents of the subject Mechatronics Design must consist of a synergistic multidisciplinary approach. These include materials starting from systematic design techniques, development of intelligent control systems, sensibility of the systems, and up-to growing multi-human-like intelligence of machines and systems. Important elements of the subject are actuators, sensors, and versatile robust controllers. Programmable controllers, microcontrollers, micro-electro-mechanical machines, adaptive fuzzy logic controllers based on neural network are found most suitable for the design and development of mechatronics products. One of the main objectives of the subject is to develop the skills of students required for the design of intelligent machines and systems with high levels of hierarchical intelligence

Scattered energy of vibration : a novel parameter for rotating shaft vibration assessment

Shafts mounted on bearings are subjected to vibrations due to many known and unknown causes. In many cases the causes of vibrations of a shaft may be initiated from the bearing parts and their manufacturing qualities. The mechanical vibration of a shaft mounted on bearings can be interpreted as chaotic oscillation of the shaft axis during its rotation and faster translation of mass in a chaotic manner and in unaccountably multiple directions. If we can determine these micro translations of mass-load including their velocity, it is possible to assess the energy created by the process of chaotic oscillations of the shaft-mass. In this article mathematical and physical modelling of scattered energy of vibrations emanated from individual causes of vibrations and the model of total scattered energy of vibrations are presented. The models correlating the total scattered energy of vibrations with the manufacturing and exploitation qualities of bearings can be used for vibration assessment of any rotating unit

Factors that influence reliable object manipulation

This paper presents various factors that influencerobotic object manipulation. Some of these factors are inherentto the object and mostly unavoidable, while others arecontrollable by the grasping and slippage control systemdesigner. Some factors, such as object texture are obviouslyinherent to the object and unavoidable for the purpose of objectmanipulation. However, other factors, such as the choice ofmechanism control resolution depend mostly on the designer. Itis anticipated that this information will be helpful to designers ofrobotic object grasping and slippage control systems, and willcontribute to better design decisions

A depth sensor to control pick-and-place robots for fruit packaging

This paper presents a powerful and inexpensive automated object detection and localization method for pick-and-place robots using a low cost, commercial 3D depth sensor.The robot control application developed for this project extracts relevant information such as the XYZ co-ordinates of an object’s location from a 3D depth map, generated by the depth sensor interface software. This information is then used by the robot control application to control a pick-and-place robot for handling object/fruit. Experiments have proven that object’s projected area and orientation can be extracted from the depth map provided by the 3D depth sensor. This type of depth sensor can be used in robotics research projects for short range environment mapping and navigation and for object detection and locating

An innovative approach for grasping force estimation using tactile and vision sensors

This paper presents a short summary of human tactile sensing, activities involved in robotic object sensing and manipulation, estimation of grasping forces, a short review of sensor integration, and control strategies used for grasping and manipulation. An innovative control model for intelligent grasping has been predicted can be helpful for wider robotic applications

Design of an innovative coal screening system using nonlinear power based electromagnetic vibroexciter: a feasibility study

Vibrating technologies are used in the different engineering fields of industries. These technologies allow to intensify the technological processes in increasing the quality of products and labour productivity. In the paper, the development of a control circuit of the electro-magnetic vibrating exciter (EMVE) has been studied. A new type of mineral screening concept design using EMVEs has been proposed. This paper represents an analysis of the nonlinear automatic oscillation system composed with a single stroke electromagnetic vibrating exciter, a velocity transducer, nonlinear amplifier and an inverter. The results were obtained for the frequency and amplitude of automatic oscillations by the describing function method depending on the parameters of the system. It was established that internal negative feedback was partly stabilized the amplitude of oscillations by the variation of frequency. The results of the paper can be used in designing and developing of Vibration setup for the wide range of frequencies

Parametric optimization of machining Ti-alloys in respect to surface roughness - a review

The uses of Titanium alloys have largely been increased due to the benefits which are very substantial in some specific areas. Their applications are not only limited to in aerospace industries and biomedical implants but also widely introduced in marine and automotive industries. Yet the optimum cutting conditions for those materials are still under investigation. Ti-alloys are inthe group of difficult-to-machine materials due to their poor machinability. The main reasons behind their poor machinability are high chemical reactivity, low modulus of elasticity and low thermal conductivity. Here in this paper a number of literatures related to optimization of machining parameters are reviewed and the problems related to machining of these Ti-alloys including their effects are summarized

Tactile sensor based intelligent grasping system

This paper offers the design and prototype technology of a tactile sensor, based on the principle of surface texture recognition, capable of monitoring slip in robotic grasping. The sensor has been mounted onto a parallel gripper jaw of a robot. The integrated system of tactile sensor, gripper, robot and the system control, in real life experiments, has proven itself capable of slip detection and adjusting adequate grasping force preventing objects from falling down. Several experiments have been carried out with the newly developed system for grasping a number of various object-samples. Success rate of the system for testing in slip detection and adjusting adequate grasping force in experiments was about 85% in average