LATEST ARTICLES
Details of the latest articles published in the Journal. Includes the most recent InPress papers (uncorrected proofs of accepted papers awaiting publication in a Journal issue).
Date: Thu, 08 Jul 2010 14:52:01 GMT
Excavators comprise a category of construction equipment and are used in a wide range of applications of varying scale. Regarding their usage in digging processes, the relevant literature records few analytical methods which, when combined with the available empirical knowledge, provide certain analytical tools, rules, and guidelines. In the present work, an approach for obtaining optimal initial positioning of excavators in digging processes is proposed. First, constraints and assumptions regarding excavator and dig geometries are stated. The excavator work space is correlated to its kinematics and the geometric locus of optimal positioning points that correspond to maximal length of the boom–arm pair is located. Then the problem of determining the volume of removed soil is analysed and subsequently reduced to the solution of the corresponding two-dimensional problem. Simple mathematical formulae are provided that relate dig and excavator geometries. Finally, Euclidean and/or Manhattan distance calculations are used for locating the point that offers the shortest path to the point of initial location of the excavator.
- Content Type Journal Article
- DOI 10.1243/09596518JSCE982
- Authors
- A Papachristou, Department of Mechanical Engineering and Aeronautics, Unviersity of Patras, Patras, Greece
- V Xaralabos, Department of Mechanical Engineering and Aeronautics, Unviersity of Patras, Patras, Greece
- A Dentsoras, Department of Mechanical Engineering and Aeronautics, Unviersity of Patras, Patras, Greece
Date: Thu, 08 Jul 2010 14:52:01 GMT
Bidens pilosa L (commonly known as cobbler's peg) is an annual broad-leaf weed in tropical and subtropical regions and reportedly needs to be identified and eliminated when farming 31 different crop varieties. This paper presents a multi-modal sensing approach for detecting Bidens leaves within wheat plants. Visual cue-based automatic discrimination of Bidens and wheat leaves is non-trivial owing to the curled-up nature of the wheat leaves. Therefore, spectral responses of Bidens and wheat leaves are first analysed to understand the discriminative spectral bands. Then a multi-modal sensory system consisting of a near infra red and a visual camera set-up is proposed. Information retrieved from the sensory setup is then processed to generate a series of cues that are fed into a classification algorithm. Classification results are validated through experimentation. The proposed technique is able to achieve an accuracy of 88–95 per cent even when there is substantial overlapping between Bidens and wheat leaves. Further, it is also shown that the algorithm is robust enough to discriminate some other commonly available plant species.
- Content Type Journal Article
- DOI 10.1243/09596518JSCE976
- Authors
- S Kodagoda, ARC Centre of Excellence for Autonomous Systems, University of Technology, Sydney, Australia
- Z Zhang, ARC Centre of Excellence for Autonomous Systems, University of Technology, Sydney, Australia
Date: Thu, 08 Jul 2010 14:52:01 GMT
Errors associated with temperature deformation in computer numerically controlled machine elements are of particular concern, especially with multiple sources of heat. The open architecture controller (OAC) offers a way to handle the issue. It has the feature to host several external devices to support full error compensation using various types of sensor that are not conventional in machine tools, such as thermal cameras and wireless temperature sensors in a network. The current paper introduces OAC principles and types as well as innovative techniques including wireless and infrared cameras to acquire spatial temperature on machines. A wide spatial mapping of errors from various sources can be implemented; for example, thermal errors that are difficult to model but could be measured and mapped over the whole machine. The resulting mapped errors are then used for error compensation in a complementary way to other existing techniques. OACs are implemented in recent machine tools to ease the hosting of external devices. This feature helps to improve error compensation, to ease early error detection, and to manage machine failures, with the objective to maintain the machine precision.
- Content Type Journal Article
- DOI 10.1243/09596518JSCE975
- Authors
- S Mekid, Department of Mechanical Engineering, King Fahd University of Petroleum and Minerals, Bldg-22 Room-161, Dhahran 31261, Saudi Arabia, smekid@kfupm.edu.sa
Date: Thu, 08 Jul 2010 14:52:01 GMT
In the present paper, a finite-time continuous gain-scheduled control problem is studied for a class of stochastic Markov jump hyperchaotic systems with state delays. By means of the gradient linearization method, the non-linear jump system is constructed by a series of linear jump models at selected working states. Then, based on the stochastic Lyapunov–Krasovskii functional approach, a new robust stochastic finite-time stabilization criterion is established and the finite-time H∞ controller is formulated for each linear jump model in the form of linear matrix inequalities. Finally, for such stochastic non-linear hyperchaotic system, the continuous gain-scheduled method is adopted and continuous finite-time gain-scheduled H∞ controllers are designed. The simulation example shows the effectiveness of the proposed techniques.
- Content Type Journal Article
- DOI 10.1243/09596518JSCE971
- Authors
- Y Y Yin, Institute of Automation, Jiangnan University, Wuxi, People's Republic of China
- F Liu, Institute of Automation, Jiangnan University, Wuxi, People's Republic of China
- P Shi, Department of Computing and Mathematical Sciences, University of Glamorgan, Pontypridd, UK
Date: Thu, 08 Jul 2010 14:52:00 GMT
It is well known that the casting and rolling processes of strip casting are integrated into a single production step for the manufacture of thin steel strips directly from molten metal. The quality of the strip casting process depends on many process parameters, such as the level of molten steel in the pool, solidification position, and roll gap. Their dynamic relationships are complex and the strip casting process has non-linear uncertainty and time-varying characteristics, so it is difficult to establish an accurate process model for designing a model-based controller to monitor strip quality. Here, a model-free adaptive fuzzy sliding-mode controller, which combines an adaptive rule with fuzzy and sliding-mode control, is proposed to monitor the level of molten metal. The proposed control strategy has online learning ability for responding to the system's non-linear and time-varying behaviours during control of the molten steel level. Since this model-free controller has simple control structure and a small number of control parameters, it is easy to implement. Simulation results based on the dynamic model and parameters of a semi-experimental system are executed to show the control performance of the proposed intelligent controller.
- Content Type Journal Article
- DOI 10.1243/09596518JSCE969
- Authors
- H-Y Chen, Department of Mechanical Engineering, Mingchi University of Technology, Taipei, Taiwan, Republic of China
- S-J Huang, Department of Mechanical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan, Republic of China
Date: Thu, 08 Jul 2010 14:52:00 GMT
A control system is regarded as the vital component of a process loop. For centuries, various control techniques have been employed to control actuators or process parameters in an effective manner to obtain the desired response. The field of control engineering has seen phenomenal changes in the past two decades or so, epitomized by the rise of ever-more sophisticated modern intelligent control techniques. However, despite such massive improvements in control techniques, century-old proportional–integral–derivative (PID) controllers are still widely used in industry and research alike owing to the simplicity of fabricating and tuning such devices. Many studies in the literature have shown that a particular variant of the PID controller, namely a robust PID, is even more effective in achieving better performance of the closed-loop system. This paper investigates the performance enhancement of the response of the auto-focusing mechanism of a surface profile measurement system using a robust PID controller as opposed to a controller tuned using the conventional Ziegler–Nichols (ZN) method. It can be observed through the reported results that the use of the former technique helps achieve the highly desired closed-loop response of fast settling time, reasonable overshoot, loop disturbance rejection, and high system bandwidth of the focusing mechanism.
- Content Type Journal Article
- DOI 10.1243/09596518JSCE966
- Authors
- N Islam, Mechatronics Research Centre, Loughborough University, Loughborough, UK
- R M Parkin, Mechatronics Research Centre, Loughborough University, Loughborough, UK
- M R Jackson, Mechatronics Research Centre, Loughborough University, Loughborough, UK
- S Elmas, Mechatronics Research Centre, Loughborough University, Loughborough, UK
- Z Kesy, Mechatronics Research Centre, Loughborough University, Loughborough, UK
- K-C Fan, Mechatronics Research Centre, Loughborough University, Loughborough, UK
Date: Thu, 08 Jul 2010 14:52:00 GMT
This paper is an extended version of the paper presented in IPROMS 2009, which analysed the effect of the problem of dimensionality on the performance of a basic artificial bee colony, harmony search, and the bees' algorithms on unimodal and multimodal well-known benchmark problems. A comparison of these algorithms was made in terms of the number of control parameters to be tuned. The algorithms considered were applied to proportional–integral–derivative (PID) controller tuning which involves the PID gains to be determined. Responses of the test systems to step input in terms of some metrics such as overshoot percentage, rising time, settling time and error are examined and also the effects of the disturbance on the control system performance and the system stability are analysed.
- Content Type Journal Article
- DOI 10.1243/09596518JSCE954
- Authors
- D Karaboga, Department of Computer Engineering, Erciyes Unviersity, Kayseri, Turkey
- B B Akay, Department of Computer Engineering, Erciyes Unviersity, Kayseri, Turkey
Date: Thu, 08 Jul 2010 14:52:00 GMT
In this paper the problem of swing-up control of an under-actuated, three-link robot gymnast (Robogymnast) is discussed. Robogymnast mimics the human acrobat who hangs from a high bar and tries to swing-up to an upside-down position with his/her hands still on the bar. Unlike human acrobats, Robogymnast's hands are firmly attached to a freely rotating high bar mounted on ball bearings. Although this helps during the swing-up phase, it poses a great challenge to balancing the robot at the upright position. The motion of Robogymnast was initiated by applying regularly changing sinusoidal torques to the two motors located respectively at its shoulder and hip joints. As the swing angle increases, the amplitudes of the applied sinusoidal torques were increased while their respective frequency was reduced proportionately. Experimental results showed successful swing-up of Robogymnast from the stable downwards position to the inverted configuration.
- Content Type Journal Article
- DOI 10.1243/09596518JSCE948
- Authors
- E E Eldukhri, Manufacturing Engineering Centre, Cardiff University, Cardiff, UK
- D Pham, Manufacturing Engineering Centre, Cardiff University, Cardiff, UK
Date: Thu, 08 Jul 2010 14:51:59 GMT
This paper presents an adaptive selection scheme for use in evolutionary algorithms (EAs). The proposed algorithm adjusts the stochastic noise level in the determination of the mating pool in order to regulate the selection pressure. This eliminates the fitness scaling problem and allows optimization of the selection pressure throughout the learning phase, overcoming the major pitfalls of most popular EA selection procedures. Experimental evidence is given to prove the superior performance of the proposed technique compared with conventional EA procedures. The results also highlight how the application of windowing techniques to the roulette wheel procedure can increase the likelihood of premature convergence.
- Content Type Journal Article
- DOI 10.1243/09596518JSCE942
- Authors
- D T Pham, Manufacturing Engineering Centre, Cardiff University, Cardiff, UK
- M Castellani, Manufacturing Engineering Centre, Cardiff University, Cardiff, UK
Date: Thu, 08 Jul 2010 14:51:59 GMT
It has been well documented that multivariate systems will benefit from application of advanced control strategies. The application of these methods has thus far been hindered for a variety of reasons which range from complexity of the design methodologies to the cost associated with implementation of these solutions. This paper shows that there exist alternative means by which existing control strategies of a multivariate system could be extended, thereby leading to increased efficiency, without the need to remove and implement a new control system installation. A realistic model of an entire pulping mill is used in this paper to show that by careful selection of only a few additional control loops which are added to the existing structure, sizeable profitability and operational gains may be achieved.
- Content Type Journal Article
- DOI 10.1243/09596518JSCE877
- Authors
- A Nobakhti, Electrical Engineering, Sharif University of Technology, Room 614, Tehran, Iran, a.nobakhti@ieee.org
Date: Thu, 08 Jul 2010 14:51:59 GMT
In the coming decade, cost reduction and energy efficiency will be the dominating success factors for any industry. Currently, the hydraulic industry is not fit to meet these demands: hydraulic systems and components are simply too expensive and too inefficient. It is important to mention that there are no fundamental reasons for the poor performance and high manufacturing, production, and engineering cost. Without doubt, hydraulics can be efficient and low-cost. However, the niche market in which the hydraulic industry operates simply does not have an alternative for the hydraulic cylinder. Without feeling the heat of competition, the hydraulic industry has not had enough incentive to invest in new products and technologies. However, changes are apparent. Relatively high labour cost already threatens the production industry in Europe and North America. Moreover, the uncertainty about future fuel and energy prices, and CO2 emission demands, will force the industry to change. If it does, it will create unprecedented market opportunities, utilizing the full potential of high power, torque, and force densities, combined with flexibility in control and power management. The fluid power industry really does not have an alternative. It is convicted to innovation.
- Content Type Journal Article
- DOI 10.1243/09596518JSCE1026
- Authors
- P Achten, Innas BV, Nikkelstr. 15, Breda 4823AE, The Netherlands, pachten@innas.com
Date: Thu, 08 Jul 2010 14:51:59 GMT
This paper presents a reconfiguration control strategy for network control systems that makes use of a fuzzy Takagi–Sugeno model for predictive control. The dynamic behaviour of a network control system is modelled by using a real-time implementation of the scheduling algorithm. Here, this is applied for a magnetic levitation system, as a plant that is also modelled using a fuzzy Takagi–Sugeno approach. Thus this paper covers several design issues, such as how to model a computer network, a plant, and a reconfiguration control strategy, as well as how the reconfiguration control strategy is modified using the fuzzy approach.
- Content Type Journal Article
- DOI 10.1243/09596518JSCE1017
- Authors
- H Benitez-Pérez, DISCA-IIMAS, Universidad Nacional Autonoma de Mexico, Mexico, Mexico
- J Ortega-Arjona, DISCA-IIMAS, Universidad Nacional Autonoma de Mexico, Mexico, Mexico
- F Cardenas-Flores, DISCA-IIMAS, Universidad Nacional Autonoma de Mexico, Mexico, Mexico
- P Quiñones-Reyes, DISCA-IIMAS, Universidad Nacional Autonoma de Mexico, Mexico, Mexico
Date: Thu, 08 Jul 2010 14:51:58 GMT
This paper deals with the problem of multi-objective fault-tolerant output tracking control for the longitudinal model of a flexible air-breathing hypersonic vehicle (FAHV). There exist some challenges for control design for the vehicles due to the inherent couplings between the propulsion system, the airframe dynamics and the presence of strong flexibility effects. This paper addresses the problem of guaranteed cost fault-tolerant output tracking control with regional poles constraints against actuator faults for the FAHV system. A nonlinear longitudinal model is adopted for control design because of the complexity of the FAHV systems. Firstly, a linearized model is established around the trim point including the state of altitude, velocity, angle of attack, pitch angle and pitch rate etc. for a nonlinear, dynamically coupled simulation model of the FAHV with the aim of multi-objective fault-tolerant output tracking control problem. Secondly, the control objective and models of actuator faults are presented. Thirdly, by utilizing Lyapunov functional approach, multi-objective analysis condition is proposed in terms of convex optimization problems, which can be easily solved via standard numerical software. Then, multi-objective fault-tolerant controller is designed such that the resulting closed-loop system is asymptotically stable and satisfies a prescribed performance cost with the simultaneous consideration of poles assignment in spite of the possible actuator failures. Finally, the simulation results are given to show the effectiveness of the proposed method, which is verified by excellent reference altitude and velocity tracking performance.
- Content Type Journal Article
- DOI 10.1243/09596518JSCE1002
- Authors
- H Li, Space Control and Inertial Technology Research Center, Harbin Institute of Technology, Harbin, People's Republic of China
- L Wu, Space Control and Inertial Technology Research Center, Harbin Institute of Technology, Harbin, People's Republic of China
- Y Si, Space Control and Inertial Technology Research Center, Harbin Institute of Technology, Harbin, People's Republic of China
- H Gao, Space Control and Inertial Technology Research Center, Harbin Institute of Technology, Harbin, People's Republic of China
- X Hu, Space Control and Inertial Technology Research Center, Harbin Institute of Technology, Harbin, People's Republic of China
Date: Wed, 23 Jun 2010 13:43:59 GMT
A fuzzy dynamical system approach is applied to the observer design of uncertain systems. In the fuzzy dynamical system, the uncertainty lies within a fuzzy set. The desirable system performance is twofold: one deterministic and one fuzzy. While the deterministic performance ensures the bottom line, the fuzzy performance enhances the cost consideration. Based on the output, an observer is proposed in order to estimate the state. The observer design is deterministic and is not IF-THEN rules-based. To improve the performance, a constrained optimization problem associated with the design is formulated. The problem can be solved analytically and its solution exists and is unique. The closed forms of the solution and the resulting minimum cost are presented.
- Content Type Journal Article
- DOI 10.1243/09596518JSCE994
- Authors
- Y-H Chen, The George W. Woodruff School, of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0405, USA, yehwa.chen@me.gatech.edu
Date: Wed, 23 Jun 2010 13:43:59 GMT
An improved robust global stability criterion is developed for uncertain neural networks with fast time-varying delays. The networks have norm-bounded parametric uncertainties. The relationship between the time-varying delay and associated extreme bounds (lower and upper) is appropriately exploited when dealing with the Lyapunov functional derivative. The developed stability criterion is delay dependent and is characterized by linear-matrix-inequality-based conditions. Numerical examples are presented to illustrate the benefits and lower conservativeness of the developed method.
- Content Type Journal Article
- DOI 10.1243/09596518JSCE943
- Authors
- M S Mahmoud, Systems Engineering Department, King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia
- A Y Al-Rayyan, Systems Engineering Department, King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia
- Y Xia, Department of Automatic Control, Beijing Institute of Technology, Beijing, People's Republic of China
Date: Wed, 23 Jun 2010 13:43:58 GMT
Non-linearity of the engine system creates a challenge in building a reliable control-oriented model (COM). The main source of non-linearity is the complex nature of the combustion process. Modern engine system configurations are increasingly complex and predicting their transient response poses additional difficulty. In the present paper, a COM is developed to address the challenges and capture the behaviour of a high-degree-of-freedom engine system. Engine combustion models are created by utilizing the high-fidelity engine cycle simulation to characterize the effects of main parameters, such as turbulence, air–fuel ratio, and residual fraction, and subsequently capturing the interrelationships with artificial neural networks. Then, system dynamics are accounted for by adding linear dynamics models. The capabilities of the proposed COM are demonstrated using a spark-ignition engine with a dual-independent cam phasing as a test case. The results indicate the model's ability to accurately predict engine responses to an arbitrary schedule of engine control inputs over the feasible operating range.
- Content Type Journal Article
- DOI 10.1243/09596518JSCE908
- Authors
- T-K Lee, Department of Mechanical Engineering, The University of Michigan, Ann Arbor, Michigan, USA
- D Kramer, US Army RDECOM TARDEC, Warren, Michigan, USA
- Z Filipi, Department of Mechanical Engineering, The University of Michigan, Ann Arbor, Michigan, USA
Date: Wed, 23 Jun 2010 13:43:58 GMT
This paper presents a framework for actuator fault accommodation using a multiple-model-based direct adaptive control approach that does not include explicit fault detection and isolation. This approach does not require exact information about the controlled system and persistent input excitations. The method can increase robustness and provides stable adaptation of unknown faults. Asymptotic model following conditions and adaptive rules are derived and system stability is guaranteed, while appropriate switching of the multiple models ensures asymptotic tracking for system outputs. An aircraft model is given to illustrate the efficiency of the proposed method.
- Content Type Journal Article
- DOI 10.1243/09596518JSCE894
- Authors
- B Jiang, College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Jiangsu, People's Republic of China
- Y Guo, College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Jiangsu, People's Republic of China
- P Shi, Department of Computing and Mathematical Sciences, University of Glamorgan, Pontypridd, UK
Date: Wed, 23 Jun 2010 13:43:58 GMT
This paper proposes new stability conditions for linear systems with a time-varying state delay. The time-varying delay is treated as a polytopic uncertainty parameter, and a Lyapunov functional that is dependent on the delay parameter is constructed. Linear matrix inequality conditions of system stability and robust stability are derived. Numerical and practical examples are given to show the effectiveness and non-conservativeness of the proposed conditions.
- Content Type Journal Article
- DOI 10.1243/09596518JSCE875
- Authors
- I-K Fong, Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan, Republic of China
- C-P Lin, Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan, Republic of China
- J-S Huang, Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan, Republic of China
Date: Wed, 23 Jun 2010 13:43:57 GMT
A modelling approach for neuro-fuzzy control of a single-link flexible robot manipulator that uses a computer-aided design (CAD) program is proposed. Initially, a CAD model of the flexible link is created using experimentally determined values of system parameters. This CAD model is then exported to MATLAB software and the Simulink/SimMechanics toolbox. An adaptive-network-based fuzzy logic controller is used for position and vibration control of the flexible link.
Experimental and simulation results are presented that validate the proposed approach.
- Content Type Journal Article
- DOI 10.1243/09596518JSCE785
- Authors
- M Tınkır, Department of Mechanical Engineering, University of Selçuk, Konya, Turkey
- Ü Önen, Department of Mechanical Engineering, University of Selçuk, Konya, Turkey
- M Kalyoncu, Department of Mechanical Engineering, University of Selçuk, Konya, Turkey
Date: Wed, 23 Jun 2010 13:43:57 GMT
This paper deals with a convex optimization approach to the problem of robust network-based H∞ control for linear systems connected over a common digital communication network with static quantizers. Both the polytopic and the norm-bounded uncertainties are taken into consideration separately. First, the effect of both the output quantization levels and the network conditions under static quantizers is investigated. Second, by introducing a descriptor technique, using a Lyapunov–Krasovskii functional and a suitable change of variables, new required sufficient conditions are established in terms of delay-range-dependent linear matrix inequalities for the existence of the desired network-based quantized controllers with simultaneous consideration of network-induced delays and measurement quantization. The explicit expression of the controllers is derived to satisfy both asymptotic stability and a prescribed level of disturbance attenuation for all admissible norm-bounded uncertainties. Two examples are utilized to illustrate the design procedure proposed in this paper.
- Content Type Journal Article
- DOI 10.1243/09596518JSCE1027
- Authors
- H R Karimi, Department of Engineering, University of Agder, Faculty of Engineering and Science, Serviceboks 509, Grimstad 4898, Norway, hamid.r.karimi@uia.no