Fabrication and characterisation of a novel smart suspension for micro-CMM probes

Abstract

Citation: ALBLALAIHID, K., KINNELL, P. and LAWES, S., 2015. Fabrication and characterisation of a novel smart suspension for micro-CMM probes.Sensors and Actuators 232, Additional Information:• This paper was accepted for publication in the journal Sensors and Ac- Abstract: In tactile micro coordinate metrology, miniature probing systems are required to allow geometric measurements of miniature, delicate, high precision components. These probing systems typically comprise of a small stylus of only a few mm in length, with a spherical tip of around 100 µm in diameter or less. The stylus is mounted to a flexible suspension structure which is designed to deflect during measurement, and defines the stiffness of the probing system. Stiffness is of critical importance for optimum measurement performance, and selection of the correct stiffness involves a difficult trade-off. Stiff probes are needed to overcome surface attraction forces which are significant for the small stylus tips, while flexible probes are needed for contact with delicate parts to reduce contact stress and ensure no damage is caused. To eliminate the need for compromise a novel micro tactile probing system with active stiffness control using a novel suspension structure has been designed. This paper presents the initial fabrication and the test of the suspension structure. The stiffness of the structure is assessed by measuring the modal frequencies of the suspension structure that correspond to vertical and lateral probe motion. Using this method results show it is possible to reduce the vertical and torsional frequency by 69% and 33 %, respectively. Using finite element analysis it is shown that this equates to vertical and lateral stiffness reductions to 12% and 46% of their initial value respectively.

Surface-Sensing Principle of Microprobe System for Micro-Scale Coordinate Metrology: A Review

“…The primary point of this probe type is to measure the deformation of the hinge with high sensitivity; therefore, multiple methods, such as optical measurement [60], capacitive sensors [22,60], and silicon membrane sensors [64] have been proposed. This hinge-type probe system has been proposed and developed [70][71][72][73][74][75][76][77][78][79][80][81][82][83][84][85][86], and certain commercially available microprobe systems of this type are available [87][88][89][90][91][92]. By designing structures and materials, hinge-type probe systems can control the stiffness of the probing system.…”

Performance Assessment of a New Variable Stiffness Probing System for Micro-CMMs

“…In the FEM, for simplicity, the effect of the actuator was modelled as a static displacement. For a range of applied actuator displacements, the stiffness and first two resonant modes of the probe were evaluated using a previously validated modelling process [ 11 ]. Figure 4 shows the simulated axial displacement (do), which is introduced by the piezoelectric actuator, plotted against the frequency and the stiffness of the probing system.…”

“…Controlling the magnitude of the compressive force, therefore, allows the probe stiffness to be controlled. A full description of the design and working principle behind the variable stiffness probing system is presented elsewhere [ 11 , 12 ].…”

Burr removal from measurement data of honeycomb core surface based on dimensionality reduction and regression analysis

“…The thin-wall and low-rigidity characteristics make it difficult to measure with contact instruments. Although the contact probe can be adapted by increasing the contact area to locate on cell walls, the deformation of cell walls is hard to be avoided, which bring about the error of measurement results [8,9]. Therefore, non-contact measurement is more suitable for measuring this material.…”