Application of MPC and sliding mode control to IFAC benchmark models

The comparison of Model Predictive Control (MPC) and Sliding Mode Control (SMC) are presented in this paper. This paper investigates the performance of each controller as the navigation system for IFAC benchmark ship models (cargo vessel and oil tanker). In this investigation the navigation system regulates the heading angle of the two types of marine vessel with reference to a desired heading trajectory. In this investigation, the result obtained from MPC is compared with a well-established control methodology, namely Sliding Mode control theory. Wave disturbances and actuator limits are implemented to provide a more realistic evaluation and comparison for the proposed control structure

Modelling and simulation of a biomimetic underwater vehicle

This paper describes work carried out at the University of Glasgow investigating biomimetic fish-like propulsion systems for underwater vehicles. The development of a simple mathematical model is described for a biomimetic fish like vehicle which utilizes a tendon drive propulsion system. This model is then compared with a model of a vehicle of similar size but with a propeller for main propulsion. Simulation results for both models are shown and compared

SoundBar: exploiting multiple views in multimodal graph browsing

In this paper we discuss why access to mathematical graphs is problematic for visually impaired people. By a review of graph understanding theory and interviews with visually impaired users, we explain why current non-visual representations are unlikely to provide effective access to graphs. We propose the use of multiple views of the graph, each providing quick access to specific information as a way to improve graph usability. We then introduce a specific multiple view system to improve access to bar graphs called SoundBar which provides an additional quick audio overview of the graph. An evaluation of SoundBar revealed that additional views significantly increased accuracy and reduced time taken in a question answering task

An ‘on-demand’ Data Communication Architecture for Supplying Multiple Applications from a Single Data Source: An Industrial Application Case Study

A key aspect of automation is the manipulation of feedback sensor data for the automated control of particular process actuators. Often in practice this data can be reused for other applications, such as the live update of a graphical user interface, a fault detection application or a business intelligence process performance engine in real-time. In order for this data to be reused effectively, appropriate data communication architecture must be utilised to provide such functionality. This architecture must accommodate the dependencies of the system and sustain the required data transmission speed to ensure stability and data integrity. Such an architecture is presented in this paper, which shows how the data needs of multiple applications are satisfied from a single source of data. It shows how the flexibility of this architecture enables the integration of additional data sources as the data dependencies grow. This research is based on the development of a fully integrated automation system for the test of fuel controls used on civil transport aircraft engines

Automation of Aircraft Engine Fuel Controls Tests: An Industrial Case Study involving PID Control of a Nozzle Emulator

The test of fuel control systems used on civil aircraft engines is performed with a network of distributed and, by design, isolated systems. The co-ordination of these test systems is performed manually by human operators in order to verify the airworthiness of a fuel control system throughout the products’ lifecycle. The main objective of this study is the automation of an existing network of systems for fuel control tests. The aspect of automation that is considered in this paper is the control of the engine nozzle emulator which is critical to determine the airworthiness of repaired fuel control systems. This system is realized using a model following PID controller design approach. The results from simulation studies and a hardware-in-the-loop test are presented. These demonstrate that this PID control structure provides the necessary level of accuracy and robustness for this engineering process

DOLPHIN: the design and initial evaluation of multimodal focus and context

In this paper we describe a new focus and context visualisation technique called multimodal focus and context. This technique uses a hybrid visual and spatialised audio display space to overcome the limited visual displays of mobile devices. We demonstrate this technique by applying it to maps of theme parks. We present the results of an experiment comparing multimodal focus and context to a purely visual display technique. The results showed that neither system was significantly better than the other. We believe that this is due to issues involving the perception of multiple structured audio sources

MultiVis: improving access to visualisations for visually impaired people

This paper illustrates work undertaken on the MultiVis project to allow visually impaired users both to construct and browse mathematical graphs effectively. We start by discussing the need for such work, before discussing some of the problems of current technology. We then discuss Graph Builder, a novel tool to allow interactive graph construction, and Sound Bar which provides quick overview access to bar graphs

Effect of Communication Delays on the Successful Coordination of a Group of Biomimetic AUVs

In this paper, the influence of delays on the ability of a formation control algorithm to coordinate a group of twelve Biomimetic Autonomous Underwater Vehicles (BAUVs) is investigated. In this study the formation control algorithm is a decentralized methodology based on the behavioural mechanisms of fish within school structures. Incorporated within this algorithm is a representation of the well-known and frequently used communication protocol, Time-Division-Multiple-Access (TDMA). TDMA operates by assigning each vehicle a specific timeslot during which it can broadcast to the remaining members of the group. The size of this timeslot varies depending on a number of operational parameters such as the size of the message being transmitted, the hardware used and the distance between neighbouring vehicles. Therefore, in this work, numerous timeslot sizes are tested that range from theoretical possible values through to values used in practice. The formation control algorithm and the TDMA protocol have been implemented within a validated mathematical of the RoboSalmon BAUV designed and manufactured at the University of Glasgow. The results demonstrate a significant deterioration in the ability of the formation control algorithms as the timeslot size is increased. This deterioration is due to the fact that as the timeslot size is increased, the interim period between successive communication updates increases and as a result, the error between where the formation control algorithm estimates each vehicle to be and where they actually are, increases. As a result, since the algorithm no longer has an accurate representation of the positioning of neighbouring vehicles, it is no longer capable of selecting the correct behavioural equation and subsequently, is unable to coordinate the vehicles to form a stable group structure

Olfoto: designing a smell-based interaction

We present a study into the use of smell for searching digi-tal photo collections. Many people now have large photo libraries on their computers and effective search tools are needed. Smell has a strong link to memory and emotion so may be a good way to cue recall when searching. Our study compared text and smell based tagging. For the first stage we generated a set of smell and tag names from user de-scriptions of photos, participants then used these to tag pho-tos, returning two weeks later to answer questions on their photos. Results showed that participants could tag effec-tively with text labels, as this is a common and familiar task. Performance with smells was lower but participants performed significantly above chance, with some partici-pants using smells well. This suggests that smell has poten-tial. Results also showed that some smells were consistently identified and useful, but some were not and highlighted issues with smell delivery devices. We also discuss some practical issues of using smell for interaction