| 1. |
|
|
| 2. |
- Bauer, Margret, et al.
(författare)
-
What control engineers should know about industry 4.0
- 2023
-
Ingår i: InTech. - 0192-303X. ; :October 2023, s. 13-23
-
Tidskriftsartikel (refereegranskat)abstract
- Control engineering is a well-established discipline with a long and prominent his-tory1. It is diverse in its applications but has a strong unifying core to it: the notion ofdynamic systems and control theory. Many engineers will have encountered it as partof their education, as control engineering courses are taught to electrical, mechanical,chemical, aerospace, and industrial engineers. Quite often, though, this is the onlytime that engineers consciously encounter the subject of control systems.While control engineering is rooted in mathematical theory and tools, Industry 4.0relies on a variety of technologies. Industry 4.0 is a new and still-evolving paradigm inwhich digitalization is expected to revolutionize industry and core technologies arestill emerging. The term was coined in 2011.
|
|
| 3. |
- Berner, Josefin, et al.
(författare)
-
An experimental comparison of PID autotuners
- 2018
-
Ingår i: Control Engineering Practice. - : Elsevier BV. - 0967-0661. ; 73, s. 124-133
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper two novel autotuners are compared with two industrially available ones. The aim is to see if the research frontline can improve the industry standard of today. Experiments are made on three laboratory processes with different characteristics. Two lag-dominated processes of which one is a level control problem with fast dynamics, and one a temperature control problem with slow dynamics, as well as one delay-dominated level control process. Both the experiments and the obtained controller performances are evaluated and discussed. The results show that the performance of the stateof-the-art industrial autotuners can be significantly improved.
|
|
| 4. |
- Berner, Josefin, et al.
(författare)
-
Autotuner identification of TITO systems using a single relay feedback experiment
- 2017
-
Ingår i: IFAC-PapersOnLine. - : Elsevier BV. - 2405-8963. ; 50:1, s. 6619-6623
-
Tidskriftsartikel (refereegranskat)abstract
- Relay autotuning has proven very successful for single-input single-output systems. This paper proposes an identification method for relay autotuning of systems with two inputs and two outputs (TITO systems). The combination of asymmetric relay feedback and output error identification admits short tuning time, without the need for limit cycle convergence. The method is successfully demonstrated on relevant system models, including the Wood-Berry distillation column.
|
|
| 5. |
- Berner, Josefin, et al.
(författare)
-
Practical Evaluation of a Novel Multivariable Relay Autotuner with Short and Efficient Excitation
- 2017
-
Ingår i: IEEE Conference on Control Technology and Applications, CCTA 2017. ; , s. 1505-1510
-
Konferensbidrag (refereegranskat)abstract
- In this paper we propose an autotuning method that combines a setup for decentralized relay autotuning of two-input two-output systems with an identification method that uses short experiments to estimate up to second-ordertime-delayed systems. A small modification of the experiment gives better low-frequency excitation and improved models. The method is successfully demonstrated in simulations and on a quadruple tank process.
|
|
| 6. |
- Berner, Josefin, et al.
(författare)
-
Short and Robust Experiments in Relay Autotuners
- 2017
-
Ingår i: Proceedings of the 2017 22nd IEEE International Conference on Emerging Technologies and Factory Automation; ETFA2017. - 9781509065059 ; , s. 1-8
-
Konferensbidrag (refereegranskat)abstract
- This paper demonstrates how second-order time-delayed models adequate for PID controller synthesis can be identified from significantly shorter relay experiments, than used in previous publications to obtain first-order time-delayed models. Apart from having good noise robustness properties, the proposed method explicitly addresses non-stationary initial states of the dynamics to be identified, and handles constant load disturbances.
|
|
| 7. |
- Cava, José Manuel Gonzáles, et al.
(författare)
-
Robust PID control of propofol anaesthesia: uncertainty limits performance, not PID structure
- 2021
-
Ingår i: Computer Methods and Programs in Biomedicine. - : Elsevier BV. - 0169-2607. ; 198, s. 1-1
-
Tidskriftsartikel (refereegranskat)abstract
- Background and objective: New proposals to improve the regulation of hypnosis in anaesthesia based on the development of advanced control structures emerge continuously. However, a fair study to analyse the real benefits of these structures compared to simpler clinically validated PID-based solutions has not been presented so far. The main objective of this work is to analyse the performance limitations associated with using a filtered PID controller, as compared to a high-order controller, represented through a Youla parameter.Methods: The comparison consists of a two-steps methodology. First, two robust optimal filtered PID controllers, considering the effect of the inter-patient variability, are synthesised. A set of 47 validated paediatric pharmacological models, identified from clinical data, is used to this end. This model set provides representative inter-patient variability Second, individualised filtered PID and Youla controllers are synthesised for each model in the set. For fairness of comparison, the same performance objective is optimised for all designs, and the same robustness constraints are considered. Controller synthesis is performed utilising convex optimisation and gradient-based methods relying on algebraic differentiation. The worst-case performance over the patient model set is used for the comparison.Results: Two robust filtered PID controllers for the entire model set, as well as individual-specific PID and Youla controllers, were optimised. All considered designs resulted in similar frequency response characteristics. The performance improvement associated with the Youla controllers was not significant compared to the individually tuned filtered PID controllers. The difference in performance between controllers synthesized for the model set and for individual models was significantly larger than the performance difference between the individual-specific PID and Youla controllers. The different controllers were evaluated in simulation. Although all of them showed clinically acceptable results, the robust solutions provided slower responses.Conclusion: Taking the same clinical and technical considerations into account for the optimisation of the different controllers, the design of individual-specific solutions resulted in only marginal differences in performance when comparing an optimal Youla parameter and its optimal filtered PID counterpart. The inter-patient variability is much more detrimental to performance than the limitations imposed by the simple structure of the filtered PID controller.
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
- Gustafsson, Fredrik, 1964-, et al.
(författare)
-
Identifiability issues in estimating the impact of interventions on Covid-19 spread
- 2020. - 5
-
Ingår i: 3rd IFAC Workshop on Cyber-Physical & Human Systems CPHS 2020. - : Elsevier BV. - 2405-8963. ; 53, s. 829-832
-
Konferensbidrag (refereegranskat)abstract
- The Covid-19 pandemic has spawned numerous dynamic modeling attempts aimed at estimation, prediction, and ultimately control. The predictive power of these attempts has varied, and there remains a lack of consensus regarding the mechanisms of virus spread and the effectiveness of various non-pharmaceutical interventions that have been enforced regionally as well as nationally. Setting out in data available in the spring of 2020, and with a now-famous model by Imperial College researchers as example, we employ an information-theoretical approach to shed light on why the predictive power of early modeling approaches have remained disappointingly poor.
|
|
