Bing Lam Luk

Intelligent legged climbing service robot for remote maintenance applications in hazardous environments

Abstract Wheeled-tracked vehicles are mainly suitable for relatively flat terrain. Legged-vehicles, on the other hand, have the potential to handle wide variety of terrain. Robug IIs is a legged climbing robot designed to work in relatively unstructured and rough terrain. It has the capability of walking, climbing vertical surfaces and performing autonomous floor to wall transfer. The sensing technique used in Robug IIs is mainly tactile and ultrasonic sensing. A set of reflexive rules has been developed for the robot to react to the uncertainty of the working environment. The robot also has the intelligence to seek and verify its own foot-holds.

Digital IIR filter design using particle swarm optimisation

Adaptive infinite-impulse-response (IIR) filtering provides a powerful approach for solving a variety of practical signal processing problems. Because the error surface of IIR filters is typically multimodal, global optimisation techniques are generally required in order to avoid local minima. This contribution applies the particle swarm optimisation (PSO) to digital IIR filter design in a realistic time domain setting where the desired filter output is corrupted by noise. PSO as global optimisation techniques offers advantages of simplicity in implementation, ability to quickly converge to a reasonably good solution and robustness against local minima. Our simulation study involving system identification application confirms that the proposed approach is accurate and has a fast convergence rate and the results obtained demonstrate that the PSO offers a viable tool to design digital IIR filters. We also apply the quantum-behaved particle swarm optimisation (QPSO) algorithm to the same digital IIR filter design and our results do not show any performance advantage of the QPSO algorithm over the PSO, although the former does have fewer algorithmic parameters that require tuning.

Digital IIR Filter Design Using Adaptive Simulated Annealing

Adaptive infinite-impulse-response (IIR) filtering provides a powerful approach for solving a variety of practical problems. Because the error surface of IIR filters is generally multi-modal, global optimisation techniques are required in order to avoid local minima. We apply a global optimisation method, called the adaptive simulated annealing (ASA), to digital IIR filter design. An important advantage of the ASA is the simplicity in software programming. Simulation study involving system identification application shows that the proposed approach is accurate and has a fast convergence rate, and the results obtained demonstrate that the ASA offers a viable tool to digital IIR filter design.

Walking and climbing service robots for safety inspection of nuclear reactor pressure vessels

Nuclear reactor pressure vessels are often required regular inspection and maintenance in order to ensure the safety of the reactors. Failing to carry out proper maintenance could cause severe casualty. The usual way of carrying out inspection in these hazardous environments is using long reach fixed base manipulators. However, these manipulators suffer from low payload capacity and relatively large end point deflections. Also, the installation and the storage of these long manipulators could be costly. An alternative solution is to use walking-climbing robots, which overcome the problems encountered by the long reach manipulators. In this paper, two robots, NERO (Nuclear Electric Robot Operator) and SADIE (Sizewell A Duct Inspection Equipment) which have been applied successfully to inspect two Magnox reactors in the UK are described. The deployment and operational experience of these robots are also explained. Finally the applications and the usefulness of these robots for improving safety inspection of nuclear reactors in general are discussed in this paper.

Tele‐operated climbing and mobile service robots for remote inspection and maintenance in nuclear industry

Purpose – Aims to report on the various types of tele‐operated mobile service robots for remote inspection and maintenance, especially in the field of nuclear industry.Design/methodology/approach – Describes nuclear electric robot operator (NERO), Sizewell A duct inspection equipment (SADIE), Robug‐IIs (all leg‐based) and Roboslave (wheel‐based).Findings – That these robots can handle a significant portion of inspection and maintenance tasks in a typical nuclear plant, though, given that they are primarily tailor‐made, they are still too expensive for ordinary industries.Originality/value – As the interests of health and safety and paramount, this study sees the use of such robots expanding and diversifying, irrespective of cost.

Using genetic algorithms to establish efficient walking gaits for an eight-legged robot

In the design and development of a legged robot, many factors need to be considered. As a consequence, creating a legged robot that can efficiently and autonomously negotiate a wide range of terrains is a challenging task. Many researchers working in the area of legged robotics have traditionally looked towards the natural world for inspiration and solutions, reasoning that these evolutionary solutions are appropriate and effective because they have passed the hard tests for survival over time and generations. This paper reports the use of genetically inspired learning strategies, commonly referred to as genetic algorithms, as an evolutionary design tool for improving the design and performance of an algorithm for controlling the leg stepping sequences of a walking robot. The paper presents a specific case of finding optimal walking gaits for an eightlegged robot called Robug IV and simulated results are provided.

A generic postprocessing technique for image compression

A postprocessing technique is developed for image quality enhancement. In this method, a distortion-recovery model extracts multiresolution edge features from the decompressed image and uses these visual features as input to estimate the difference image between the original uncompressed image and the decompressed image. Coding distortions are compensated by adding the model output to the decompressed image. Unlike many existing postprocessing methods, which smooth blocking artifacts and are designed specifically for transform coding or vector quantization, the proposed technique is generic and can be applied to all of the main coding methods. Experimental results involving postprocessing four coding systems show that the proposed technique achieves significant improvements on the quality of reconstructed images, both in terms of the objective distortion measure and subjective visual assessment.

Fuzzy-logic tuned constant modulus algorithm and soft decision-directed scheme for blind equalisation

This contribution revisits blind equalisation for high-order quadrature amplitude modulation systems using a low-complexity high-performance concurrent constant modulus algorithm (CMA) and soft decision-directed (SDD) scheme. A fuzzy-logic (FL) tuning unit is designed to adjust the step size of the CMA, and the potential benefits of using this adaptive step size approach are investigated. Simulation results obtained confirm that faster convergence can be achieved with this FL assisted CMA and SDD scheme, compared with the previous constant step-size CMA and SDD scheme. Quantitatively, the former requires several thousands fewer samples to converge to the same steady-state solution achieved by the latter.

Application of service robots for building NDT inspection tasks

Purpose – Building inspection tasks usually involve working at life‐threatening height, especially for high‐rise buildings. The purpose of this paper is to introduce two service robots which are designed for high‐rise building inspection applications.Design/methodology/approach – The first service robot, equipped with independent‐climbing capability, is applied to gas pipe inspection. The robot requires very little setup time and is suitable for some small inspection tasks. The second, which shares some similarities of industrial gondolas, is applied to check the health conditions of tile‐walls of high‐rise buildings. This robot requires more initial setup time but can provide faster inspection operations. In addition, it can be programmed to carry out the inspection task automatically. So, it is more suitable for large‐scale inspection tasks.Findings – For tile‐wall inspection, a fast, low‐cost and effective non‐destructive testing technique based on impact acoustic method has been developed for the robo...

An Intelligent Networking and Automation System for Home and SOHO Environments

The ever increasing desires for improvement in efficiency and comfort for individuals’ home and office environments have provided the driving force for the recent development in Home/SOHO automation and networking systems. This paper presents a new Home/SOHO automation system which is designed for handling heterogeneous network systems. The laboratory-built system makes use of OSGi (Open Service Gateway Initiative) open standard to provide a flexible framework for adding and removing devices and appliances in an ad hoc manner. Since end users of the system may not necessarily be very computer literate, UPnP (Universal Plug and Play) open standard is being used to make the network connection of various devices as transparent to the users as possible. The current experimental Home/SOHO system can support Bluetooth wireless network, Lonworks, IR, C-bus, 315MHz, 418MHz and 433MHz ISM band RF, and broadband Internet communication. The proposed system can certainly provide a platform for developing Home/SOHO commercial products and it is also flexible enough for developing and experimenting with other Home/SOHO automation technologies