William Thompson

Non-contact, optically based measurement of surface roughness of ceramics

Examination of various research efforts has revealed that optical techniques best satisfy the requirements of on-line, non-contact inspection; other methods are usually deficient with regard to speed, flexibility and ability to perform non-contact measurement. Of the optical methods considered, techniques based on statistical analysis of scattered light from the sample are best suited for the purpose of surface inspection. A general scheme for an on-line, non-contact, optically based inspection machine has been developed. The system has the important attributes of fast measurement, simplicity and flexibility. The systems roughness measurement capability was successfully tested on ceramic components of varying surface finish.

A new type of machine control system to replace traditional CNC

This paper discusses the rationale behind a new form of machine tool control system which has been developed at the Key Centre for Computer Integrated Manufacture (CIM Centre) in Melbourne Australia. The new control system is based upon standard computer hardware and is intended as a replacement for computer numerical control (CNC), which has severe limitations in the CIM environment. The paper also outlines the new CIM possibilities which are now available as a result of this development.

Three‐dimensional measurement using a single image

The instant invention relates to high surface area multilayered oxide supports coated with ruthenium of the type Ru-MgO-MgAl2O4-MgAl2O4+Mg2SiO4-Core. The system comprises ruthenium on a critical amount of free MgO, i.e., at least 2 wt. % minimum, on pre-reacted Al2O3 which itself is on a monolithic ceramic substrate. This combination demonstrates the desirable, and previously unachievable characteristic of resistance to ruthenium volatilization and agglomeration, coupled with high catalytic activity. The high surface area oxides (MgO+Al2O3) are strongly bonded to and reacted with the monolithic core substructure so as to possess physical strength. Ruthenium catalyst systems prepared utilizing the supported support (multilayered mixed oxides) method disclosed by the instant invention are useful for the treatment of waste gases, particularly exhaust gases from internal combustion engines and stationary sources and the removal of oxides of nitrogen therefrom.

A methodology for investigating effects of cell size on operational flexibility in flexible manufacturing systems

There are two aspects to cell formation in flexible manufacturing systems, cell sizing or deciding on the optimum number of machines to be allocated to each cell, and then allocation of specific machines to each cell. Although the latter problem has been investigated extensively there is a paucity of published work on the former. This paper discusses the effects of cell sizing on operational flexibility.Operational flexibility is that aspect of flexibility that enables manufacturing systems to respond with speed and efficiency to changes in the manufacturing environment while maintaining an effective level of control.

Detection and modeling of rough component envelopes

This paper describes an imaging technique for the determination of rough component envelopes of cast and forged components. The paper includes several image acquisition methods currently used in this area but concentrates in detail on the method known as the light stripe method. Results presented show the advantages of the light stripe method to obtain a fast and accurate 3D description of the cast and forged components. The research is part of a larger project on intelligent manufacturing systems and is being conducted at the CIM Centre, Swinburne University of Technology, Hawthorn, Victoria, Australia.

Intelligent machining of rough components from optimized CAD models

This paper describes a technique for automatically generating NC machine programs from CAD images of a rough work piece and an optimally positioned component. The paper briefly compares the generative and variant methods of automatic machine program development and then presents a technique based on the variant method where a reference machine program is transformed to machine the optimized component. The transformed machine program is examined to remove any redundant cutter motions and correct any invalid cutter motions. The research is part of a larger project on intelligent manufacturing systems and is being conducted at the CIM Centre, Swinburne University of Technology, Hawthorn, Australia.

Survey of methodologies for the real time non-contact inspection of internal defects within thick high-density components

The purpose of this paper is to identify the most promising methodology for an application involving real time component inspection. The components which are of a thick high density nature are to be inspected for internal defects such as cracks, cavities and voids. The alternative methodologies to be evaluated include x-radiology, ultrasonic testing and neutron radiology. The authors of this paper contend that, due to the lengthy exposure times and the high cost of suitable generators, neutron techniques are incapable of satisfying the real time component of this application. Although ultrasonic techniques are very sensitive to the presence of defects, it is much more difficult to accurately and reliably determine their size. The authors have found that in light of the highly sensitive nature of ultrasound, it maybe suitable for the application. The paper also examines x-radiological methods in terms of hardware limitations and techniques used to overcome these problems. In terms of detecting and evaluating in real time, the extent of defects within thick high density components, the most suitable techniques have been evaluated.

Investigation of surface texture of unsintered machined zirconia using laser light

Laser light is used to investigate the surface texture of unsintered machined zirconia. Unsintered zirconia is a chalkylike material and when machined the resultant surface texture cannot be measured using conventional stylus techniques because the stylus damages the surface. Therefore the surface must be inspected in a noncontact fashion to reveal the surface texture. Laser scattering methods are well known to provide good surface texture characterisation so this approach was pursued. Zirconia samples were machined with varying feedrates and illuminated with a laser beam. The resultant scattering distributions for each of the surfaces did not differ in any significant way (regardless of the machining feedrate used) suggesting that the size of the microscopic irregularities of the surface are significantly greater than the illuminating wavelength. SEM photographs of the surfaces showed this to be true. Surface texture characterisation of unsintered machined zirconia using laser scattering was thus not possible. The properties of the material are such that the roughness of the machined zirconia is beyond the range measurable with most laser techniques.