| 1. |
- Andersson, Bengt-Åke, et al.
(författare)
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Use of a conductivity heat-flow meter in fluidised-bed boilers
- 1989
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Ingår i: Transactions of the Institute of Measurement and Control. - : SAGE Publications. - 1477-0369 .- 0142-3312. ; 11:2, s. 108-112
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Tidskriftsartikel (refereegranskat)abstract
- The usefulness of a conductivity type of heat-flow meter for measurements in fluidised-bed boilers is investigated. The design and the calibration of the meter are described. Results from measurements of the local heat tranfer at the walls of fluidised-bed boilers are presented. An error analysis shows that the accuracy of the heat-flow meter is +-9%.
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| 2. |
- Bahraini, Masoud, 1991, et al.
(författare)
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Sliding mode control revisited
- 2020
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Ingår i: Transactions of the Institute of Measurement and Control. - : SAGE Publications. - 1477-0369 .- 0142-3312. ; 42:14, s. 2698-2707
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Tidskriftsartikel (refereegranskat)abstract
- Controller design for nonlinear systems in its general form is complicated and an open problem. Finding a solution to this problem becomes more complicated when unwanted terms, such as disturbance, are taken into account. To provide a robust design for a subclass of nonlinear systems, sliding mode controllers (SMCs) are used. These controllers have a systematic design procedure and can reject bounded disturbances and at the same time guarantee stability. The guaranteed stability is achieved by separating system states into two parts and assuming that the input to state stability (ISS) condition holds for internal dynamics. This condition restricts the applicability of the SMC and limits the system performance when the controller is designed based on that. In order to remove this restriction and improve the performance, the ISS condition has been relaxed in this study. The relaxation is performed by redesigning SMCs based on suggested Lyapunov functions. The proposed idea insures global asymptotic stability of the closed loop system and is used to revise different well-known SMCs such as conventional SMC, terminal SMC, non-singular terminal SMC, integral SMC, super-twisting SMC, and super-twisting integral SMC. Comparisons between conventional and revised versions are made using simulation to demonstrate excellence of the revisited controllers.
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| 3. |
- Farhang, P., et al.
(författare)
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Combined design of VSC-HVDC and PSS controllers for LFO damping enhancement
- 2014
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Ingår i: Transactions of the Institute of Measurement and Control. - : SAGE Publications. - 1477-0369 .- 0142-3312. ; 36:4, s. 529-540
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this paper is to present a novel combined design of the voltage source converter–high voltage direct current (VSC-HVDC) and the power system stabilizer (PSS) controllers to obtain a better dynamical response. The proposed technique is applied to enhance the damping of the power system low-frequency oscillations (LFOs) and results are compared with traditional design. A fuzzy logic controller is designed for PSS (FPSS). Then, a chaotic optimization algorithm, which has a strong ability for finding the most optimistic results, is employed, in presence of FPSS, to search for optimal VSC-HVDC output feedback controller parameters. Moreover, a singular value decomposition method is utilized to select the most effective damping control signal of the VSC-HVDC output feedback controllers. The novel proposed controllers are evaluated on an AC/DC power system. The simulation results demonstrate that the combined controllers have an excellent capability for damping power system LFOs and greatly enhance the dynamic stability of the power system. Also, the system performance analysis under different operating conditions and some performance indices show the effectiveness of the proposed controllers. The benefit of the suggested procedure is greatly improving the dynamic response of the system. In addition, the overshoots, undershoots and the settling times are dramatically reduced by applying the proposed method.
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| 4. |
- Hollnagel, Erik
(författare)
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Modelling the controller of a process
- 1999
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Ingår i: Transactions of the Institute of Measurement and Control. - 0142-3312 .- 1477-0369. ; 21:4-5, s. 163-170
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Tidskriftsartikel (refereegranskat)abstract
- Models of humans (operators, controllers) in human-machine systems have tacitly assumed that humans must have a model of the process in order to control it. Humans have therefore traditionally been described as information processing systems with an internal or mental model of the process as an important component. A more systemic or cybernetic view acknowledges that the human must be a model of the process in order to control it. This suggests a different approach to modelling, which is functional rather than structural, and where the emphasis is on how the joint human-machine system can maintain control of a situation. A specific model, called the Contextual Control Model (COCOM), which is based on the principles of cognitive systems engineering, illustrates the approach, COCOM provides a foundation for analysing controller performance as well as implementing controller needs.
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| 5. |
- Lou, Chuyue, et al.
(författare)
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Recent deep learning models for diagnosis and health monitoring : a review of researches and future challenges
- 2023
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Ingår i: Transactions of the Institute of Measurement and Control. - London : Sage Publications. - 0142-3312 .- 1477-0369.
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Tidskriftsartikel (refereegranskat)abstract
- As an important branch of machine learning, deep learning (DL) models with multiple hidden layer structures have the ability to extract highly representative features from the input. At present, fault detection and diagnosis (FDD) and health monitoring solutions developed based on DL models have received extensive attention in academia and industry along with the rapid improvement of computing power. Therefore, this paper focuses on a comprehensive review of DL model–based FDD and health monitoring schemes in view of common problems of industrial systems. First, brief theoretical backgrounds of basic DL models are introduced. Then, related publications are discussed about the development of DL and graphical models in the industrial context. Afterwards, public data sets are summarized, which are associated with several research papers. More importantly, suggestions on DL model–based diagnosis and health monitoring solutions and future developments are given. Our work will have a positive impact on the selection and design of FDD solutions based on DL and graphical models in the future. © The Author(s) 2023.
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| 6. |
- Paul, Satyam, 1981-, et al.
(författare)
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Discrete-time sliding mode for building structure bidirectional active vibration control
- 2019
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Ingår i: Transactions of the Institute of Measurement and Control. - : Sage Publications Ltd.. - 0142-3312 .- 1477-0369. ; 41:2, s. 433-446
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Tidskriftsartikel (refereegranskat)abstract
- In terms of vibrations along bidirectional earthquake forces, several problems are faced when modelling and controlling the structure of a building, such as lateral-torsional vibration, uncertainties surrounding the rigidity and the difficulty of estimating damping forces.In this paper, we use a fuzzy logic model to identify and compensate the uncertainty which does not require an exact model of the building structure. To attenuate bidirectional vibration, a novel discrete-time sliding mode control is proposed. This sliding mode control has time-varying gain and is combined with fuzzy sliding mode control in order to reduce the chattering of the sliding mode control. We prove that the closed-loop system is uniformly stable using Lyapunov stability analysis. We compare our fuzzy sliding mode control with the traditional controllers: proportional?integral?derivative and sliding mode control. Experimental results show significant vibration attenuation with our fuzzy sliding mode control and horizontal-torsional actuators. The proposed control system is the most efficient at mitigating bidirectional and torsional vibrations.
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| 7. |
- Qi, Wen, et al.
(författare)
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Multimodal data fusion framework enhanced robot-assisted minimally invasive surgery
- 2022
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Ingår i: Transactions of the Institute of Measurement and Control. - : SAGE Publications. - 0142-3312 .- 1477-0369. ; 44:4, s. 735-743
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Tidskriftsartikel (refereegranskat)abstract
- The generous application of robot-assisted minimally invasive surgery (RAMIS) promotes human-machine interaction (HMI). Identifying various behaviors of doctors can enhance the RAMIS procedure for the redundant robot. It bridges intelligent robot control and activity recognition strategies in the operating room, including hand gestures and human activities. In this paper, to enhance identification in a dynamic situation, we propose a multimodal data fusion framework to provide multiple information for accuracy enhancement. Firstly, a multi-sensors based hardware structure is designed to capture varied data from various devices, including depth camera and smartphone. Furthermore, in different surgical tasks, the robot control mechanism can shift automatically. The experimental results evaluate the efficiency of developing the multimodal framework for RAMIS by comparing it with a single sensor system. Implementing the KUKA LWR4+ in a surgical robot environment indicates that the surgical robot systems can work with medical staff in the future.
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| 8. |
- Sharifi, Maryam
(författare)
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Robust finite-time consensus subject to unknown communication time delays based on delay-dependent criteria
- 2022
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Ingår i: Transactions of the Institute of Measurement and Control. - : SAGE Publications. - 0142-3312 .- 1477-0369. ; 44:6, s. 1205-1216
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, robust finite-time consensus of a group of nonlinear multi-agent systems in the presence of communication time delays is considered. In particular, appropriate delay-dependent strategies which are less conservative are suggested. Sufficient conditions for finite-time consensus in the presence of deterministic and stochastic disturbances are presented. The communication delays don’t need to be time invariant, uniform, symmetric, or even known. The only required condition is that all delays satisfy a known upper bound. The consensus algorithm is appropriate for agents with partial access to neighbor agents’ signals. The Lyapunov–Razumikhin theorem for finite-time convergence is used to prove the results. Simulation results on a group of mobile robot manipulators as the agents of the system are presented.
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| 9. |
- Söderström, Torsten
(författare)
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System identification for the errors-in-variables problem
- 2012
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Ingår i: Transactions of the Institute of Measurement and Control. - : SAGE Publications. - 0142-3312 .- 1477-0369. ; 34:7, s. 780-792
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we give an overview of errors-in-variables methods in system identification. Background and motivation are given. Simple examples illustrate why the identification problem can be difficult. Under general weak assumptions, the systems are not uniquely identifiable, but can be parameterized using one degree of freedom. Examples where identifiability is achieved under additional assumptions are also provided. A number of approaches for parameter estimation of errors-in-variables models are presented. The underlying assumptions and principles for each approach are highlighted.
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| 10. |
- Wang, Lihui
(författare)
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An overview of internet-enabled cloud-based cyber manufacturing
- 2017
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Ingår i: Transactions of the Institute of Measurement and Control. - : SAGE PUBLICATIONS LTD. - 0142-3312 .- 1477-0369. ; 39:4, s. 388-397
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents an overview of the latest advancement of Internet-enabled cloud-based cyber manufacturing and new approaches for hardware-in-the-loop real-time applications, including cloud-based remote monitoring and control of industrial robots, remote assembly in a cyber-physical environment, and a cloud robotic system for energy-efficient operations. Altogether, they form an integrated cloud-based cyber manufacturing system. In terms of enabling technologies, they are the unique combination of virtual 3D models driven by real sensors, and image-to-model based representation of dynamic environment to guide cyber users. The objective of this research is to significantly reduce network traffic over the Internet for cyber manufacturing. This paper includes case studies, the results of which show that the integrated cyber-physical system consumes less than 1% of network bandwidth of traditional camera-based systems with a 30msec latency of real-time operations. They are feasible and practical as cyber manufacturing solutions.
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