Constrained control of free piston engine generator based on implicit reference governor

Gong, Xun; Kolmanovsky, Ilya; Garone, Emanuele; Zaseck, Kevin; Chen, Hong

doi:10.1007/s11432-017-9337-1

Cited by 13 publications

(8 citation statements)

References 16 publications

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“…Model predictive control (MPC) can be a superior method for the online solution of the optimal trajectory [24], [25]. In MPC methods, the optimal problem can be online solved in a moving predictive horizon [26], [27], which provides great advantages in changing the predictive model, predictive horizon, constraints, performance index, and even the optimal problem form. Different from the current application with MPC-based trajectory planning, firstly, in order to adapt to more scenarios, the model considers more characteristics simultaneously so that it can execute different parameter-based decisions in different scenarios.…”

Section: A State-of-the-art Review and Challengesmentioning

confidence: 99%

A Novel Trajectory Planning Method for Automated Vehicles Under Parameter Decision Framework

et al. 2019

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Decision and control in all stack scenarios comprise a key issue in the design of automated vehicle control systems. Thus, in higher level, automated vehicles, the decision and the form of the decision should be able to adapt to diverse, changeable, and complex scenarios, which increase the complexity of trajectory planning. In this paper, a parameter decision framework in which the decision is described with key parameters, rather than specific behaviors, such as lane-changing or car-following, is considered. Under this framework, a novel trajectory planning method is proposed to implement behavior with integrated longitudinal and lateral control, in which a nonlinear motion control model is established. The nonlinear model predictive control (NMPC) method with terminal constraints without a predefined path form is applied, which presents more flexibility for changeable decisions. Both the trajectory planning controller and the overall framework are verified by simulation. The results show the validity of the controller and the framework. INDEX TERMS Model predictive control, trajectory planning, decision-making, integrated longitudinal and lateral control.

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Section: A State-of-the-art Review and Challengesmentioning

confidence: 99%

A Novel Trajectory Planning Method for Automated Vehicles Under Parameter Decision Framework

et al. 2019

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“…For the mixed control strategy, LEM and combustion parameters will be used to actively control piston motion. X. Gong et al studied nonlinear control scheme and proposed a model predictive control (MPC) strategy of dual-cylinder FPLG [49,[58][59][60][61][62]. The researchers built a nonlinear, discrete- In [37,38], considering the acceleration and deceleration characteristic of piston motion, the ladder-like reference electro-magnetic force control strategy was implemented to control piston dead centers, as shown in Figure 28.…”

Section: The Mixed Control Strategymentioning

confidence: 99%

“…For the mixed control strategy, LEM and combustion parameters will be used to actively control piston motion. X. Gong et al studied nonlinear control scheme and proposed a model predictive control (MPC) strategy of dual-cylinder FPLG [49,[58][59][60][61][62]. The researchers built a nonlinear, discrete- Active LEM control is a reliable and effective strategy for the piston motion control.…”

Section: The Mixed Control Strategymentioning

confidence: 99%

A Review of the Design and Control of Free-Piston Linear Generator

et al. 2018

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The Free-piston linear generator (FPLG) is a novel energy converter which can generate electrical energy and is regarded as a potential technology for solving the restriction of the short driving range of electric vehicles. Getting rid of the crank and flywheel mechanism, FPLG obtains some advantages of a variable compression ratio, compact size, and highly-efficient power generation. Linear electric machine (LEM) design and piston motion control are two key technologies of FPLG. However, they are currently the main obstacles to the favorable performance of FPLG. LEM being used to drive the piston motion or generate electric energy is an integrated design including a motor/generator. Various types of LEMs are investigated, and suitable application scenarios based on advantages and disadvantages are discussed. The FPLG's controller is used to ensure stable operation and highly-efficient output. However, cycle-to-cycle variations of the combustion process and motor/generator switching make it difficult to improve the performance of the piston motion control. Comments on the advantages and disadvantages of different piston motion control methods are also given in this paper.The piston moves freely between TDC and bottom dead center (BDC), and its motion is determined by the resultant force that is acting upon it, including gas pressure force, electro-magnetic force, and rebound force [8][9][10]. The piston motion must be controlled by an electronic control system-an electronic crankshaft, which is an integrated control of combustion parameters or control variables of the LEM and rebound devices [5]. Moreover, there are cycle-to-cycle variations and periodic large disturbances during the combustion process. As a result, piston motion control is still the biggest challenge of FPLG [11]. Besides, LEM is not only used as a power output unit but also a control unit for adjusting the movement of the piston. For the FPLG, LEM requires high reliability, high precision, high efficiency, and so on. Various structures of LEM designed by many teams around the world have been investigated, but none of these meet all of the requirements due to the short stroke, high frequency, and high acceleration.In order to lucubrate the current existing problems, this paper reviews the key technologies of LEM design and FPLG motion control. Firstly, several basic structures of FPLG are introduced, and both their advantages and disadvantages are analyzed. Afterwards, according to the different types of structure, corresponding advantages and disadvantages of LEMs are presented. With respect to the existing LEMs, they are classified according to the different flux path and topology structures in the third section. Finally, different starting methods are introduced based on the FPLG's structure. In terms of power generation stage, piston motion control strategies are divided into three forms and introduced based on their control variables. They include three categories: active combustion parameters control, active LEM control, and the mixed cont...

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“…The predictive horizon in velocity control is normally to the second level, while fuel injection and NH 3 dosing are controlled within tens of milliseconds. It is hard to identify the optimal control variables in the typical NMPC optimal problem [18], [19]. Overall, for achieving high fuel efficiency and low emissions, how to coordinate the multiobjective optimal problem remains a formidable challenge.…”

Section: Introductionmentioning

confidence: 99%

Sequential Optimization of Eco-Driving Taking Into Account Fuel Economy and Emissions

Zhao

Gao

2019

IEEE Access

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The regulations for diesel vehicles are expected to become increasingly more stringent. However, how to coordinate eco-driving, the diesel engine and the urea selective catalytic reduction (urea-SCR) system for fuel economy improvement and emissions reduction remains a formidable challenge. In this paper, a sequential optimization control method with three stages is designed. In stage I, the optimal driving force and braking force are obtained by solving a nonlinear optimization problem of tracking the vehicle velocity profile. In stage II, a real-time reference estimation model is designed to provide the optimal ammonia coverage ratio target. In stage III, to implement the driving force requirement and ammonia coverage ratio target, an integrated engine and urea-SCR system control method and a distributed method are proposed, respectively. The distributed method consists of a fuel injection controller utilizing a data-driven predictive method and a NH 3 dosing controller utilizing nonlinear model predictive control (NMPC). The control model of the integrated method is represented by the first-order ammonia coverage ratio dynamics only. The results show that the fuel consumption is improved by 5.3% and the PM emission is reduced by 11.56% during the partial transient acceleration process, and that the fuel consumption and emissions of the integrated control method can accomplish the level of the distributed method and achieve the trade-off between the multi-objective. However, the integrated control method incurs an average computational time penalty of 15.47%. INDEX TERMS Diesel vehicles, urea selective catalytic reduction (urea-SCR) system, sequential optimization, nonlinear model predictive control (NMPC), Pontryagin's minimum principle (PMP).

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Constrained control of free piston engine generator based on implicit reference governor

Cited by 13 publications

References 16 publications

A Novel Trajectory Planning Method for Automated Vehicles Under Parameter Decision Framework

A Novel Trajectory Planning Method for Automated Vehicles Under Parameter Decision Framework

A Review of the Design and Control of Free-Piston Linear Generator

Sequential Optimization of Eco-Driving Taking Into Account Fuel Economy and Emissions

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