Search results

Articulated robots are widely used in industrial applications owing to their high repeatability accuracy. In terms of new applications such as robot-based inspection systems, the limitation is a lack of pose accuracy. Mostly, robot calibration approaches are used for the improvement of the pose accuracy. Such approaches however require a profound understanding of the determining effects. This paper aims to provide a non-destructive analysis method for the identification and characterisation of non-geometric accuracy effects in relation to the kinematic structure for the purpose of an accuracy enhancement.

The analysis is realised by a non-destructive method for rotational, uncoupled robot axes with the use of a 3D lasertracker. For each robot axis, the lasertracker position data for multiple reflectors are merged with the joint angles given by the robot controller. Based on this, the joint characteristics are determined. Furthermore, the influence of the kinematic structure is investigated.

This paper analyses the influence of the kinematic structure and non-geometric effects on the pose accuracy of standard articulated robots. The provided method is shown for two different industrial robots and presented effects incorporate tilting of the robot, torsional joint stiffness, hysteresis, influence of counter balance systems, as well as wear and damage.

Based on these results, an improved robot model for a better match between the mathematical description and the real robot system can be achieved by characterising non-geometric effects. In addition, wear and damages can be identified without a disassembly of the system.

The presented method for the analysis of non-geometric effects can be used in general for rotational, uncoupled robot axes. Furthermore, the investigated accuracy influencing effects can be taken into account to realise high-accuracy applications.

‘As Gregor Samsa awoke one morning from uneasy dreams, he found himself transformed in his bed into a gigantic insect. He was laying on his hard, as it were armour-plated, back and when he lifted his head a little, he could see his domelike brown belly divided into stiff arched segments on top of which the bed quilt could hardly keep in position and was about to slide off completely. His numerous legs, which were pitifully thin compared to the rest of his bulk, waved helplessly before his eyes’ (Kafka, The Metamorphosis, 1915, p. 19).

Kafka's The Metamorphosis (1915) appears in disability theory to aid explanation for those who experience acquired disability. This allegory offers a visceral picture of what a person can go through; there is a before and an after, a death and a life. I was able-bodied, capable, bursting with energy and then I woke up one morning utterly transformed. I no longer recognise myself; my consciousness mourns my previous existence, and I must come to terms with my reconstituted self.

It is that ‘other’ that I identify with now and, to discover what that means, I began composing a Requiem Mass. I have a long love affair with them; I have sung and conducted them and their ability to pierce the veil between life and death is of particular significance to me. This chapter examines the ways in which my acquired disability, this mystical death, impacts and informs my composition.

Before the appearance of our next issue, the Annual Meeting of the Library Association will have taken place. In many ways, as indicated last month, it will be an interesting meeting, largely because it is in the nature of an experiment. International conditions, the state of national and municipal finance, the absence of library workers with the colours, and the omission of social events, all tend to influence its character. It is possible, however, that these very circumstances may increase the interest in the actual conference business, especially as the programme bears largely upon the War. The programme itself is formidable, and it will be interesting to see how the section on the literature of the war, for example, will be treated. Probably the Publications' Committee have in mind the book symposia which are a feature of the meetings of various library associations in the United States. These consist of a few minutes' characterisation, by an opener, of a certain book or type of literature, and a discussion after it. The experiment was attempted in London last year at one of the monthly meetings, but owing to a misapprehension the speaker gave an excellent lecture on Francis Thompson of more than an hour's duration, when he had been expected to give a brief description of Francis Meynell's biography of that poet. If any gatherings for a similar purpose are arranged, we hope the speakers will be primed sufficiently to avoid that error. As for social events, their omission is less likely to be felt in London than anywhere else in the Kingdom. London is a perennial source of social amusement in itself, and the evenings can readily be filled there—“chacun à son goût”—really better than by attending pre‐arranged gatherings.

A configurable reference model can be used to assist in the development and management of business processes in complex, multi-stakeholder environments. The purpose of this paper is to demonstrate a process design in such environments via configurable process reference modelling, using airports as an example.

Existing reference modelling methods around process modelling, merging and configuration are extended to include contextual and spatial factors using the design science methodology. The approach is empirically based on a set of business process management notation (BPMN) models for international passenger departures, consolidated from five Australian airport case studies via document analysis, interviews and observation.

The use of contextual factors and operational scenarios, structured using the proposed approach, facilitated efficient cross-organisational comparison for configuring processes to suit the needs of a target organisation. The resulting configurable model integrates the perspectives of organisational stakeholder groups with that of the customer in a transparent and unambiguous graphical representation. It is a reusable tool with low data collection needs for each use.

Future research should include: version management; how to keep the model current; configurability via modelling objects other than gateways; and cross-discipline application (e.g. as a foundation for quantitative decision-making models).

This is the first reported application of configurable reference modelling to airport passenger facilitation. Methodological contributions include the addition of space-sensitive process elements and notation to BPMN; guidelines for systematically deriving contextual factors associated with process variants across similar organisations; and overall normative guidelines for inductively developing a configurable process reference model.