Multi-objective optimization of nonlinear switched time-delay systems in fed-batch process

Liu, Chongyang; Gong, Zhenfeng; Teo, Kok Lay; Feng, Enmin

doi:10.1016/j.apm.2016.07.010

Cited by 23 publications

(8 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For the multiobjective problems, previous studies suggest the gradient-based solution [24,25]. As described in [25], when the objective function is nondifferentiable, gradientbased optimization techniques are not suitable for dynamic programming models with constraints. Moreover, there are many potential local extrema in the charging model, and the gradient descent algorithm can easily lead to pseudoconvergence.…”

Section: Complexitymentioning

confidence: 99%

The Multiobjective Based Large‐Scale Electric Vehicle Charging Behaviours Analysis

Zhou

Wang

2018

Complexity

View full text Add to dashboard Cite

In the paper, the effect of the charging behaviours of electric vehicles (EVs) on the grid load is discussed. The residential traveling historical data of EVs are analyzed and fitted to predict their probability distribution, so that the models of the traveling patterns can be established. A nonlinear stochastic programming model with the maximized comprehensive index is developed to analyze the charging schemes, and a heuristic searching algorithm is used for the optimal parameters configuration. With the comparison of the evaluation criteria, the multiobjective strategy is more appropriate than the single-objective strategy for the charging, i.e., electricity price. Furthermore, considering the characteristics of the normal batteries and charging piles, user behaviour and EV scale, a Monte Carlo simulation process is designed to simulate the large-scale EVs traveling behaviours in long-term periods. The obtained simulation results can provide prediction for the analysis of the energy demand growth tendency of the future EVs regulation. As a precedent of open-source simulation system, this paper provides a stand-alone strategy and architecture to regulate the EV charging behaviours without the unified monitoring or management of the grid.

show abstract

Section: Complexitymentioning

confidence: 99%

The Multiobjective Based Large‐Scale Electric Vehicle Charging Behaviours Analysis

Zhou

Wang

2018

Complexity

View full text Add to dashboard Cite

show abstract

“…, 10. The initial values of switching instants and terminal time [56] are listed in Table 3. It should be noted that these initial values of switching instants are obtained from Table 2.…”

Section: Phase Start Time (H) End Time (H)mentioning

confidence: 99%

“…Therefore, we just listed these six values and the other values of switching instants are missing entries (denoted by hyphens). The lower and upper bound vectors in (7) [56]. From vectors ρ and δ, we obtained the lower and upper bounds of switching instants and terminal time, which are also listed in Table 3.…”

Section: Phase Start Time (H) End Time (H)mentioning

confidence: 99%

“…Similarly, the missing entries in the column of the lower bound in Table 3 denote that switchings occur after the terminal time. Besides, the Table 3: Initial values, optimal values, and lower and upper bounds for the switching instants and terminal time [56]. Note that the missing entries in the table denote that the switchings occur after the terminal time.…”

Section: Phase Start Time (H) End Time (H)mentioning

confidence: 99%

See 1 more Smart Citation

Robust multi-objective optimal switching control arising in 1,3-propanediol microbial fed-batch process

Liu

Gong

Teo

et al. 2017

Nonlinear Analysis: Hybrid Systems

Self Cite

View full text Add to dashboard Cite

This paper considers optimal control of glycerol producing 1,3-propanediol (1,3-PD) via microbial fed-batch fermentation. The fed-batch process is formulated as a nonlinear switched time-delay system. In general, the time-delay in the fed-batch process cannot be exactly estimated. Our goal is to design an optimal switching control scheme to simultaneously maximize 1,3-PD productivity and 1,3-PD yield under time-delay uncertainty. Accordingly, we propose a robust multi-objective optimal switching control model, in which two objectives, i.e., 1,3-PD productivity and 1,3-PD yield, and their sensitivities with respect to uncertain time-delay are considered in the objective vector. The control variables in this problem are the feeding rate of glycerol, the switching instants and the terminal time of the process. By introducing an auxiliary dynamic system to calculate the objective sensitivities and performing a time-scaling transformation, we obtain an equivalent multi-objective optimal switching control problem in standard form. We then convert the equivalent multi-objective optimal control problem into a sequence of single-objective optimal switching control problems by using a modified normal boundary intersection method. A novel gradient-based single-objective solver combining control parameterization with constraint transcription technique is developed to solve these resulting singleobjective optimal control problems. Finally, numerical results are provided to verify the effectiveness of the proposed solution approach.

show abstract

“…In fact, the optimal control problem considered in this paper has wide applications in the practical engineering; see, for example [10,23]. To solve these engineering problems using our developed computational method is our undergoing studies.…”

mentioning

confidence: 99%

Optimal control of switched systems with multiple time-delays and a cost on changing control

Gong¹,

Liu²,

Wang³

2018

Journal of Industrial &Amp; Management Optimization

Self Cite

View full text Add to dashboard Cite

In this paper, we consider a class of optimal switching control problems with multiple time-delays and a cost on changing control and subject to terminal state constraints. A computational method involving three stages is developed to solve this class of optimal control problems. First, by parameterizing the control function with piecewise-constant functions, the optimal switching control problem is approximated by a sequence of finite-dimensional optimization problems, where the original switching times, the control heights and the control switching times are decision variables. Second, by introducing new variables, the total variation of the control variables is transformed into an equivalently smooth function. Third, we convert the constrained optimization problem into one only with box constraints by an exact penalty function method. The gradients of the cost functional are then derived, which can be combined with any gradient-based optimization method to determine the optimal solution. Finally, a numerical example is given to illustrate the effectiveness of the proposed algorithm.

show abstract

Multi-objective optimization of nonlinear switched time-delay systems in fed-batch process

Cited by 23 publications

References 38 publications

The Multiobjective Based Large‐Scale Electric Vehicle Charging Behaviours Analysis

The Multiobjective Based Large‐Scale Electric Vehicle Charging Behaviours Analysis

Robust multi-objective optimal switching control arising in 1,3-propanediol microbial fed-batch process

Optimal control of switched systems with multiple time-delays and a cost on changing control

Contact Info

Product

Resources

About