Near-Optimal Control Strategy in Leader-Follower Networks: A Case Study for Linear Quadratic Mean-Field Teams

The effect of fuel topology and control on thermal endurance of aircraft using fuel as a heat transfer agent was studied using an optimal dynamic solver (OPT). The dynamic optimal solutions of the differential equations governing the heat transfer of recirculated fuel flows for single- and dual-tank arrangements were obtained. The method can handle sudden jumps of operating conditions across different operating zones during mission and/or situations when control parameters have reached their physical limits. Although this method is robust in providing an optimal control strategy to prolong thermal endurance of aircrafts, it is not ideal for practical application because the method required iterative procedures to solve expensive nonlinear equations. The linear quadratic regulator (LQR), the feedback controller, can be derived by linearizing the adjoint equations at trim points to offer a simple control strategy, which can then be implemented directly in the feedback control hardware. The solutions obtained from both OPT and LQR were compared, and it was found two solutions were almost identical except in regions having sudden jump of operation conditions. Finally, a comparison between single- and dual-tank arrangements was made to demonstrate the importance of the flow topology. The study shows the dual-tank arrangement allows flexibility in how energy is managed and can release energy faster than a single-tank topology and hence provides improved aircraft thermal endurance.

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Modeling and Optimal Shift Control of a Planetary Two-Speed Transmission

World Electric Vehicle Journal ◽

10.3390/wevj10030053 ◽

2019 ◽

Vol 10 (3) ◽

pp. 53

Author(s):

Zhao ◽

Tang

Keyword(s):

Optimal Control ◽

Control Strategy ◽

Linear Quadratic Regulator ◽

Gear Ratio ◽

Bench Test ◽

Bldc Motor ◽

Linear Quadratic ◽

Optimal Control Strategy ◽

Rotation Direction ◽

Engagement Process

To improve the efficiency of electric vehicles (EVs), a planetary two-speed transmission is proposed, which consists of a brushless direct current (BLDC) motor, a turbo-worm reducer, two multi-disc wet brakes, and a Simpson planetary gearset. Based on the devised electronic actuator for shifting, the rotation direction of the BLDC shaft determines the gear ratio of the transmission. For acquiring smooth shift, the state-space equations with control variables of transmission are derived, and a three-stage algorithm is suggested. During the brake engagement process, the optimal control strategy has been developed using linear quadratic regulator control, considering the jerk and friction work of the brake. The simulation results show that the proposed optimal control strategy could reduce the slipping friction work of the brake and improve the shifting quality of EVs. The optimal control trajectory of the BLDC motor was conducted on the electronic shifting actuator bench test.

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Linear–quadratic optimal control strategy for periodic-review inventory systems

Automatica ◽

10.1016/j.automatica.2010.09.010 ◽

2010 ◽

Vol 46 (12) ◽

pp. 1982-1993 ◽

Cited By ~ 45

Author(s):

Przemysław Ignaciuk ◽

Andrzej Bartoszewicz

Keyword(s):

Optimal Control ◽

Control Strategy ◽

Inventory Systems ◽

Periodic Review ◽

Linear Quadratic ◽

Optimal Control Strategy ◽

Linear Quadratic Optimal Control ◽

Quadratic Optimal Control ◽

Periodic Review Inventory

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Control system of magnetic bearings based on linear quadratic method of optimal control strategy

Chinese Journal of Mechanical Engineering ◽

10.3901/cjme.2005.02.237 ◽

2005 ◽

Vol 18 (02) ◽

pp. 237

Author(s):

Huangqiu Zhu

Keyword(s):

Optimal Control ◽

Control System ◽

Control Strategy ◽

Magnetic Bearings ◽

Linear Quadratic ◽

Optimal Control Strategy

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On closed-loop equilibrium strategies for mean-field stochastic linear quadratic problems

ESAIM Control Optimisation and Calculus of Variations ◽

10.1051/cocv/2019057 ◽

2020 ◽

Vol 26 ◽

pp. 41

Author(s):

Tianxiao Wang

Keyword(s):

Optimal Control ◽

Closed Loop ◽

Optimal Control Problems ◽

Mean Field ◽

Open Loop ◽

Time Inconsistency ◽

Control Problems ◽

Linear Quadratic ◽

Linear Quadratic Optimal Control ◽

Equilibrium Strategies

This article is concerned with linear quadratic optimal control problems of mean-field stochastic differential equations (MF-SDE) with deterministic coefficients. To treat the time inconsistency of the optimal control problems, linear closed-loop equilibrium strategies are introduced and characterized by variational approach. Our developed methodology drops the delicate convergence procedures in Yong [Trans. Amer. Math. Soc. 369 (2017) 5467–5523]. When the MF-SDE reduces to SDE, our Riccati system coincides with the analogue in Yong [Trans. Amer. Math. Soc. 369 (2017) 5467–5523]. However, these two systems are in general different from each other due to the conditional mean-field terms in the MF-SDE. Eventually, the comparisons with pre-committed optimal strategies, open-loop equilibrium strategies are given in details.

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