Distributed controller design for a class of sparse singular systems with privacy constraints

In the current research on distributed control of interconnected large-scale dynamical systems an often neglected issue is the desire to ensure privacy of subsystems. This gives motivation for the presented distributed controller design method which requires communication and the exchange of model data only with direct neighbors. Thus, no global system knowledge is required. An important property of many large-scale systems is the presence of algebraic conservation constraints, for example in terms of energy or mass flow. Therefore, the presented controller design takes these constraints explicitly into account while preserving the sparsity structure of the distributed system necessary for a distributed design. The computation is based on the simulation of the system states and of adjoint states. The control objective is represented by the finite horizon linear quadratic cost functional

Optimal consensus control of the Cucker-Smale model

We study the numerical realisation of optimal consensus control laws for agent-based models. For a nonlinear multi-agent system of Cucker-Smale type, consensus control is cast as a dynamic optimisation problem for which we derive first-order necessary optimality conditions. In the case of a smooth penalisation of the control energy, the optimality system is numerically approximated via a gradient-descent method. For sparsity promoting, non-smooth l1-norm control penalisations, the optimal controllers are realised by means of heuristic methods. For an increasing number of agents, we discuss the approximation of the consensus control problem by following a mean-field modelling approach

Accelerated Iterative Distributed Controller Synthesis with a Barzilai-Borwein Step Size

Distributed control of large-scale dynamical systems poses a new challenge to the field of control driven by the technological advances of modern communication networks. A particular challenge is the distributed design of such control systems. Here, a distributed iterative controller synthesis method for continuous time linear systems using a gradient descent method is presented. One of the main contributions is the determination of the step size according to a distributed Barzilai-Borwein (BB) method. As the control objective, we treat the finite horizon linear quadratic cost functional. The gradient approach uses communication only with direct neighbors and is based on the forward simulation of the system states and the backwards simulation of adjoint states. The effectiveness of the approach is shown by means of numerical simulations

Pameran Reka Cipta, Penyelidikan dan Inovasi (PRPI) 2009

PRPI 2009 kini telah memasuki tahun penganjurannya yang ke-7. Pameran penyelidikan di UPM telah bermula sejak tahun 1997 semasa Exhibition & Seminar Harnessing for Industry Advantage. Pada tahun 2002, Pameran Reka Cipta dan Penyelidikan (PRP) buat pertama kali telah diadakan dengan menggunakan konsep pertandingan hasil projek penyelidikan yang telah dijalankan oleh para penyelidik UPM. Kejayaan penganjuran PRP 2002 telah merintis usaha untuk menjadikannya sebagai aktiviti tahunan UPM dan ianya terus berkembang sejajar dengan nama baharunya yang ditukar kepada Pameran Reka Cipta, Penyelidikan dan Inovasi yang bermula penganjurannya pada tahun 2005. Sebagai kesinambungan daripada kejayaan penganjuran PRPI 2006, 2007 dan 2008 yang lalu dan status UPM sebagai salah sebuah Universiti Penyelidikan, PRPI 2009 kali ini yang merupakan pameran penyelidikan yang terbesar di UPM terus dilaksanakan dengan aspirasi dan semangat yang lebih jitu. Pameran ini juga menjadi pelantar kepada para penyelidik untuk mengenengahkan hasil penyelidikan yang dijalankan dan penemuan baharu kepada umum. Di samping itu ianya juga menjadi penanda aras terhadap kualiti sesuatu projek penyelidikan bagi melayakkan para penyelidik UPM untuk menyertai pameran di peringkat kebangsaan dan seterusnya antarabangsa. Adalah diharapkan pelaksanaan PRPI 2009 ini akan dapat menyemarakkan budaya penyelidikan di kalangan staf dan juga pelajar UPM sekaligus menjadikan UPM sebagai Universiti Penyelidikan yang cemerlang di negara ini

Materials Coatings and Enhanced Characterisation for Alkaline Water-Splitting Devices

A number of material coatings were investigated, specifically for 316-grade stainlesssteel electrodes, for use with alkaline water-splitting electrolysis. The aim was to enhancelongevity, particularly with respect to the highly intermittent usage that is typical of renewableenergy generation, and to increase activity. Long-term experiments were conductedover many thousands of cycles of on-off accelerated ageing at constant current density. Theeffects of ageing were analysed using chronopotentiometry, cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), scanning electron microscopy, energy dispersivex-ray spectroscopy, x-ray photoelectron spectroscopy and gas chromatography. It was foundthat titanium nitride did not have high activity for the hydrogen evolution reaction (HER),and underwent rapid oxidation and destruction if used as an anode. A new version ofelectrodeposited Raney nickel was developed that demonstrated improved activity, includingan overpotential for the HER at 10mAcm-2 of just 28 mV. As a bifunctional catalystit demonstrated an overpotential at 10mAcm-2 of just 319 mV, making it the second mostactive catalyst known, and certainly the simplest to deposit. This activity was traced to theincreased electrochemical surface area of the coating, which was higher as deposited, andincreased by up to a factor of three after ageing. During surface-area measurements, anapparent anomaly was discovered between results obtained for the same electrode via EISand CV. New methods of equivalent circuit fitting to transient waveforms were developed,and the anomaly was explained by time-domain simulations of the constant-phase elementrepresentation of the double-layer capacitance. A zero-gap electrolyser was constructed inorder to investigate its performance, and it was found that woven stainless-steel mesh couldoperate as a gas-separation membrane

A vision-based optical character recognition system for real-time identification of tractors in a port container terminal

Automation has been seen as a promising solution to increase the productivity of modern sea port container terminals. The potential of increase in throughput, work efficiency and reduction of labor cost have lured stick holders to strive for the introduction of automation in the overall terminal operation. A specific container handling process that is readily amenable to automation is the deployment and control of gantry cranes in the container yard of a container terminal where typical operations of truck identification, loading and unloading containers, and job management are primarily performed manually in a typical terminal. To facilitate the overall automation of the gantry crane operation, we devised an approach for the real-time identification of tractors through the recognition of the corresponding number plates that are located on top of the tractor cabin. With this crucial piece of information, remote or automated yard operations can then be performed. A machine vision-based system is introduced whereby these number plates are read and identified in real-time while the tractors are operating in the terminal. In this paper, we present the design and implementation of the system and highlight the major difficulties encountered including the recognition of character information printed on the number plates due to poor image integrity. Working solutions are proposed to address these problems which are incorporated in the overall identification system.postprin