Alireza Karimi | EPFL - Academia.edu (original) (raw)
Uploads
Papers by Alireza Karimi
Communications and Control Engineering, 2011
Building an adaptive control system supposes that in the case in which the plant parameters are k... more Building an adaptive control system supposes that in the case in which the plant parameters are known, a controller achieving the desired performances can be designed. Therefore this chapter reviews a number of digital control strategies used for the design of the underlying controller whose parameters will be adapted. Pole placement, tracking and regulation with independent objectives, minimum variance control, generalized predictive control and linear quadratic control are presented in detail.
Communications and Control Engineering, 2011
In this chapter, we will focus on the identification of plant models operating in open loop using... more In this chapter, we will focus on the identification of plant models operating in open loop using recursive parameter estimation.
52nd IEEE Conference on Decision and Control, 2013
Control Engineering Practice, 2015
An iterative controller tuning method based on a frequency criterion is proposed in this paper. T... more An iterative controller tuning method based on a frequency criterion is proposed in this paper. The frequency criterion is defined as the weighted sum of squared errors between the desired and actual value of the modulus margin (inverse of the infinity norm of the sensitivity function), phase margin and crossover frequency. The criterion is minimized using the iterative Gauss-Newton algorithm.
European Journal of Control, 2000
2015 American Control Conference (ACC), 2015
CONFIDENTIAL. Limited circulation. For review only.
Journal of Process Control, 2014
ABSTRACT Performance of any model-based control scheme depends on the quality of model. When thes... more ABSTRACT Performance of any model-based control scheme depends on the quality of model. When these schemes deliver poor loop performance due to model-plant mismatch (MPM), a detection of the same needs to be in place. A recently introduced plant model ratio (PMR) not only detects MPM but also facilitates a unique identification of the source of mismatch, namely, gain, dynamics (time constant) and delay mismatches. The prime objective of this work is to improve the PMR approach in a few key aspects, namely, estimation and experimental effort, and assessment procedure by taking a fresh perspective of PMR and conducting a detailed theoretical study of its signatures. A rigorous assessment procedure based on the theoretical properties of PMR is devised. Three threshold-based hypotheses tests are proposed for significance testing of PMR. A key contribution of this work is the design of set-point with minimal excitation for diagnosis of MPM, based on the features of PMR. The revised methodology is demonstrated and compared with the existing method through simulation examples. The study also demonstrates the potential of the proposed method in serving as a prelude to full/partial model re-identification.
A linear programming approach is proposed to tune fixed-order linearly parameterized gain-schedul... more A linear programming approach is proposed to tune fixed-order linearly parameterized gain-scheduled controllers for stable SISO linear parameter varying (LPV) plants. The method is based on the shaping of the open-loop transfer functions in the Nyquist diagram with ...
... Furthermore, Re = 0 amper--turn'sec' W b is assumed for all radial bearings because... more ... Furthermore, Re = 0 amper--turn'sec' W b is assumed for all radial bearings because of the lamination. For the thrust bearing, Re = 1258.8ampeT$~rn'sec , CY = 0.8318 and h = 531.23pm were identified. 4. Controller Design ...
Communications and Control Engineering, 2011
Building an adaptive control system supposes that in the case in which the plant parameters are k... more Building an adaptive control system supposes that in the case in which the plant parameters are known, a controller achieving the desired performances can be designed. Therefore this chapter reviews a number of digital control strategies used for the design of the underlying controller whose parameters will be adapted. Pole placement, tracking and regulation with independent objectives, minimum variance control, generalized predictive control and linear quadratic control are presented in detail.
Communications and Control Engineering, 2011
In this chapter, we will focus on the identification of plant models operating in open loop using... more In this chapter, we will focus on the identification of plant models operating in open loop using recursive parameter estimation.
52nd IEEE Conference on Decision and Control, 2013
Control Engineering Practice, 2015
An iterative controller tuning method based on a frequency criterion is proposed in this paper. T... more An iterative controller tuning method based on a frequency criterion is proposed in this paper. The frequency criterion is defined as the weighted sum of squared errors between the desired and actual value of the modulus margin (inverse of the infinity norm of the sensitivity function), phase margin and crossover frequency. The criterion is minimized using the iterative Gauss-Newton algorithm.
European Journal of Control, 2000
2015 American Control Conference (ACC), 2015
CONFIDENTIAL. Limited circulation. For review only.
Journal of Process Control, 2014
ABSTRACT Performance of any model-based control scheme depends on the quality of model. When thes... more ABSTRACT Performance of any model-based control scheme depends on the quality of model. When these schemes deliver poor loop performance due to model-plant mismatch (MPM), a detection of the same needs to be in place. A recently introduced plant model ratio (PMR) not only detects MPM but also facilitates a unique identification of the source of mismatch, namely, gain, dynamics (time constant) and delay mismatches. The prime objective of this work is to improve the PMR approach in a few key aspects, namely, estimation and experimental effort, and assessment procedure by taking a fresh perspective of PMR and conducting a detailed theoretical study of its signatures. A rigorous assessment procedure based on the theoretical properties of PMR is devised. Three threshold-based hypotheses tests are proposed for significance testing of PMR. A key contribution of this work is the design of set-point with minimal excitation for diagnosis of MPM, based on the features of PMR. The revised methodology is demonstrated and compared with the existing method through simulation examples. The study also demonstrates the potential of the proposed method in serving as a prelude to full/partial model re-identification.
A linear programming approach is proposed to tune fixed-order linearly parameterized gain-schedul... more A linear programming approach is proposed to tune fixed-order linearly parameterized gain-scheduled controllers for stable SISO linear parameter varying (LPV) plants. The method is based on the shaping of the open-loop transfer functions in the Nyquist diagram with ...
... Furthermore, Re = 0 amper--turn'sec' W b is assumed for all radial bearings because... more ... Furthermore, Re = 0 amper--turn'sec' W b is assumed for all radial bearings because of the lamination. For the thrust bearing, Re = 1258.8ampeT$~rn'sec , CY = 0.8318 and h = 531.23pm were identified. 4. Controller Design ...