Enhancement of accuracy of multi-axis machine tools through error measurement and compensation of errors using laser interferometry technique

Abstract

The present era is witnessing advancement in digital electronics and microprocessor which enables manufacturing sector capable to produce complex components within small tolerance zone in the tune of nanometre and at one machining center. All motion control systems have some form of position feed back system fitted with the machine. Such systems are not generally accurate due to the errors in the positioning performance of the machine tool which will change over time to time due to wear, damage and environmental effects. The complex structure of multi-axis CNC machine tools produce an inaccuracy at the tool tip caused by kinematic parameter deviations resulting in manufacturing errors, assembly errors or quasi-static errors. Analysis of these errors using a laser measurement system provides the manufacturers a way to achieve better accuracy and hence higher quality output from these processes. In this communication, techniques to measure the linear positional errors of axes of CNC machine tools by a laser interferometer calibration system and accuracy enhancement using the data obtained from the calibration cycle by feeding into the machine's controller with the help of linear error compensation package are discussed.

Research on the Novel Hardware Configuration Methods of the Contact R-test Based on the Constraint Models

“…In order to study the propagation of various actual errors in the process of solving the spherical center coordinates, and analyze their influence on the final measurement accuracy, the degree of influence of various influencing factors on the measurement performance of the measuring instrument can be calculated through the Guide to the Expression Uncertainty in Measurement(GUM) and Monte Carlo Method(MCM) based on the Eqs. (6). The analysis of the degree of influence of specific hardware precision parameters on measurement accuracy will be given in section 4.2 and the analysis results will be given in section 5.1 for a specific case.…”

“…Assuming that the three sensors have the same indication precision(ΔL1=ΔL2=ΔL3=ΔL), the method of variable parameters is used to analyze and observe the influence of the precision of the sensor's indication and the ball radius on the final measuring accuracy of the measuring instrument based on the Eqs. (6). And the sensitivity coefficient is used to characterize the degree of influence more intuitively.…”

“…At this stage, there is no unified standard and specification for the measuring method of the axis of rotation error. Although measuring tools such as Double ball-bar(DBB) [1,2] , laser tracker [3][4][5] and laser interferometer [6] can be used for identification and compensation, they all have certain limitations. In recent years, a high-efficiency and high-precision rotary axis error measuring device R-test has been developed.…”

The effect on the tool flank wear width VBmax during turning of Hybrid Mg/(8wt% SiC(p) +2wt% Al2O3(p) +1wt% Gr(p) MMC using PVD coated cermet tool

“…chopped fibres and woven roving, and discovered that as the particle strength and specimen hardness increased, so did the impact strength and specimen hardness. Barman et al [11] investigated the impact of the laser interferometry technique and demonstrated that these laser measurement systems provide higher accuracy and quality. Kumar et al found out the during the turning of nanocomposites Al2219 alloy matrix there is a formation of build up edge at lower cutting speed values.…”

Accurate pressure control of a pneumatic actuator with a novel pulse width modulation–sliding mode controller using a fast switching On/Off valve

“…Recently, growing demand for micromachining with minimal capital investment has inspired further studies for investigating the capabilities of different methods and actuators. 1,2 Since pneumatic systems have many distinguishable features such as energy saving, cleanliness, ease of maintenance, accessibility of air, simple structure and operation, and low cost and high power-to-weight ratio, they have been extensively used for many years in industrial automation (Moor 3 ). Since pneumatic actuators are soft and compliant, their application in rehabilitative robots has been studied by a growing number of researchers.…”