scholarly journals Modeling and Control of Combustion Phasing in Dual-Fuel Compression Ignition Engines

2018 ◽  
Vol 141 (5) ◽  
Author(s):  
Wenbo Sui ◽  
Jorge Pulpeiro González ◽  
Carrie M. Hall
Keyword(s):  
Steady State ◽  
Control Method ◽  
Feedforward Control ◽  
Control Strategies ◽  
Combustion Process ◽  
Open Loop ◽  
Integral Model ◽  
Dual Fuel ◽  
Complex Method ◽  
Model Based

Dual-fuel engines can achieve high efficiencies and low emissions but also can encounter high cylinder-to-cylinder variations on multicylinder engines. In order to avoid these variations, they require a more complex method for combustion phasing control such as model-based control. Since the combustion process in these engines is complex, typical models of the system are complex as well and there is a need for simpler, computationally efficient, control-oriented models of the dual-fuel combustion process. In this paper, a mean-value combustion phasing model is designed and calibrated, and two control strategies are proposed. Combustion phasing is predicted using a knock integral model (KIM), burn duration (BD) model, and a Wiebe function, and this model is used in both an adaptive closed loop controller and an open loop controller. These two control methodologies are tested and compared in simulations. Both control strategies are able to reach steady-state in five cycles after a transient and have steady-state errors in CA50 that are less than ±0.1 CA deg (CAD) with the adaptive control strategy and less than ±1.5 CAD with the model-based feedforward control method.

scholarly journals Flatness-Based Control of a Two Degrees-of-Freedom Platform With Pneumatic Artificial Muscles

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
David Bou Saba ◽  
Paolo Massioni ◽  
Eric Bideaux ◽  
Xavier Brun
Keyword(s):  
Degrees Of Freedom ◽  
Control Method ◽  
Sliding Mode ◽  
Feedforward Control ◽  
Volume Ratio ◽  
Open Loop ◽  
Control Technique ◽  
Artificial Muscles ◽  
Two Degrees Of Freedom ◽  
Pneumatic Artificial Muscles

Pneumatic artificial muscles (PAMs) are an interesting type of actuators as they provide high power-to-weight and power-to-volume ratio. However, their efficient use requires very accurate control methods taking into account their complex and nonlinear dynamics. This paper considers a two degrees-of-freedom platform whose attitude is determined by three pneumatic muscles controlled by servovalves. An overactuation is present as three muscles are controlled for only two degrees-of-freedom. The contribution of this work is twofold. First, whereas most of the literature approaches the control of systems of similar nature with sliding mode control, we show that the platform can be controlled with the flatness-based approach. This method is a nonlinear open-loop controller. In addition, this approach is model-based, and it can be applied thanks to the accurate models of the muscles, the platform and the servovalves, experimentally developed. In addition to the flatness-based controller, which is mainly a feedforward control, a proportional-integral (PI) controller is added in order to overcome the modeling errors and to improve the control robustness. Second, we solve the overactuation of the platform by an adequate choice for the range of the efforts applied by the muscles. In this paper, we recall the basics of this control technique and then show how it is applied to the proposed experimental platform. At the end of the paper, the proposed approach is compared to the most commonly used control method, and its effectiveness is shown by means of experimental results.

Optimal Pitch Control Design With Disturbance Rejection for the Controls Advanced Research Turbine

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
David Wenzhong Gao ◽  
Xiao Wang ◽  
Jianhui Wang ◽  
Tianqi Gao ◽  
Margareta Stefanovic ◽  
...  
Keyword(s):  
Steady State ◽  
Wind Turbine ◽  
Feedforward Control ◽  
State Regulation ◽  
Rotor Speed ◽  
Coupled Modes ◽  
Control Approach ◽  
Pitch Control ◽  
Model Based ◽  
The Impact

Advanced and model-based control techniques have become prevalent in modern wind turbine controls in the past decade. These methods are more attractive compared to the commonly used proportional-integral-derivative (PID) controller, as the turbine structural flexibility is increased with multiple and coupled modes. The disturbance accommodating control (DAC) is an effective turbine control approach for the above-rated wind speed region. DAC augments the turbine state-space model with a predefined disturbance waveform model, based on which the controller reduces the impact of wind disturbances on the system output (e.g., rotor speed). However, DAC cannot completely reject the wind disturbance in certain situations, and this results in steady-state regulation errors in the turbine rotor speed and electric power. In this paper, we propose a novel wind turbine pitch control using optimal control theory. The obtained feedback and feedforward control terms function to stabilize the turbine system and reject wind disturbances, respectively, derived systematically based on the Hamilton–Jacobi–Bellman (HJB) equation. Simulation results show that the proposed method achieves desired rotor speed regulation with significantly reduced steady-state errors under turbulent winds, which is simulated on the model of the three-bladed controls advanced research turbine (CART3) using the FAST code.

scholarly journals Combustion phasing modeling and control for compression ignition engines with high dilution and boost levels

2018 ◽  
Vol 233 (7) ◽  
pp. 1834-1850 ◽  
Author(s):  
Wenbo Sui ◽  
Carrie M Hall
Keyword(s):  
Steady State ◽  
Control Strategy ◽  
Internal Combustion Engines ◽  
Integral Model ◽  
Loop Control ◽  
Model Based Control ◽  
Model Based ◽  
Crank Angle Degree ◽  
Crank Angle ◽  
Phasing Control

Because fuel efficiency is significantly affected by the timing of combustion in internal combustion engines, accurate control of combustion phasing is critical. In this paper, a nonlinear combustion phasing model is introduced and calibrated, and both a feedforward model–based control strategy and an adaptive model–based control strategy are investigated for combustion phasing control. The combustion phasing model combines a knock integral model, burn duration model, and a Wiebe function to predict the combustion phasing of a diesel engine. This model is simplified to be more suitable for combustion phasing control and is calibrated and validated using simulations and experimental data that include conditions with high exhaust gas recirculation fractions and high boost levels. Based on this model, an adaptive nonlinear model–based controller is designed for closed-loop control, and a feedforward model–based controller is designed for open-loop control. These two control approaches were tested in simulations. The simulation results show that during transient changes, the CA50 (the crank angle at which 50% of the mass of fuel has burned) can reach steady state in no more than five cycles and the steady-state errors are less than ±0.1 crank angle degree for adaptive control and less than ±0.5 crank angle degree for feedforward model–based control.

EXPLOITING OPTIMAL CONTROL FOR TARGET-ORIENTED MANIPULATION OF (BIO)CHEMICAL SYSTEMS: A MODEL-BASED APPROACH TO SPECIFIC MODIFICATION OF SELF-ORGANIZED DYNAMICS

2005 ◽  
Vol 19 (25) ◽  
pp. 3763-3798 ◽  
Author(s):  
D. LEBIEDZ
Keyword(s):  
Optimal Control ◽  
Control Strategies ◽  
Open Loop ◽  
External Control ◽  
Spatiotemporal Pattern ◽  
Chemical Systems ◽  
Spatiotemporal Pattern Formation ◽  
Model Based ◽  
Self Organized ◽  
Feedback Optimal Control

In this paper we review recent progress in the development and application of advanced optimal control methods for target-oriented manipulation of self-organized dynamics in (bio)chemical reaction systems. We discuss results related to nonlinear model-based external control aimed at forcing and stabilization of spatiotemporal pattern formation and specific driving, phase resetting and annihilation of limit cycle oscillators. We refer to both open-loop and feedback optimal control approaches. Optimal control strategies for self-organized systems may be highly beneficial in applications concerned with steering of technical processes in open non-equilibrium systems and specific manipulation of self-organized cellular dynamics in biomedicine.

scholarly journals Cylinder-specific model-based control of combustion phasing for multiple-cylinder diesel engines operating with high dilution and boost levels

2018 ◽  
Vol 21 (7) ◽  
pp. 1231-1250
Author(s):  
Wenbo Sui ◽  
Carrie M Hall ◽  
Gina Kapadia
Keyword(s):  
Steady State ◽  
Diesel Engines ◽  
Specific Model ◽  
Integral Model ◽  
Loop Control ◽  
Model Based Control ◽  
Model Based ◽  
Crank Angle Degree ◽  
Crank Angle ◽  
The Impact

Accurate control of combustion phasing is indispensable for diesel engines due to the strong impact of combustion timing on efficiency. In this work, a non-linear combustion phasing model is developed and integrated with a cylinder-specific model of intake gas. The combustion phasing model uses a knock integral model, a burn duration model, and a Wiebe function to predict CA50 (the crank angle at which 50% of the mass of fuel has burned). Meanwhile, the intake gas property model predicts the exhaust gas recirculation fraction and the in-cylinder pressure and temperature at intake valve closing for different cylinders. As such, cylinder-to-cylinder variation of the pressure and temperature at intake valves closing is also considered in this model. This combined model is simplified for controller design and validated. Based on these models, two combustion phasing control strategies are explored. The first is an adaptive controller that is designed for closed-loop control and the second is a feedforward model–based control strategy for open-loop control. These two control approaches were tested in simulations for all six cylinders, and the results demonstrate that the CA50 can reach steady-state conditions within 10 cycles. In addition, the steady-state errors are less than ±0.1 crank angle degree with the adaptive control approach and less than ±1.3 crank angle degree with feedforward model–based control. The impact of errors on the control algorithms is also discussed in the article.

scholarly journals Control of functional electrical stimulation for restoration of motor function

2017 ◽  
Vol 30 (3) ◽  
pp. 295-312
Author(s):  
Dejan Popovic
Keyword(s):  
Biological Control ◽  
Electrical Stimulation ◽  
Functional Electrical Stimulation ◽  
Control Method ◽  
Level Structure ◽  
Open Loop ◽  
Model Based Control ◽  
Model Based ◽  
Assistive Systems ◽  
Artificial Control

An injury or disease of the central nervous system (CNS) results in significant limitations in the communication with the environment (e.g., mobility, reaching and grasping). Functional electrical stimulation (FES) externally activates the muscles; thus, can restore several motor functions and reduce other health related problems. This review discusses the major bottleneck in current FES which prevents the wider use and better outcome of the treatment. We present a control method that we continually enhance during more than 30 years in the research and development of assistive systems. The presented control has a multi-level structure where upper levels use finite state control and the lower level implements model based control. We also discuss possible communication channels between the user and the controller of the FES. The artificial controller can be seen as the replica of the biological control. The principle of replication is used to minimize the problems which come from the interplay of biological and artificial control in FES. The biological control relies on an extensive network of neurons sending the output signals to the muscles. The network is being trained though many the trial and error processes in the early childhood, but staying open to changes throughout the life to satisfy the particular needs. The network considers the nonlinear and time variable properties of the motor system and provides adaptation in time and space. The presented artificial control method implements the same strategy but relies on machine classification, heuristics, and simulation of model-based control. The motivation for writing this review comes from the fact that many control algorithms have been presented in the literature by the authors who do not have much experience in rehabilitation engineering and had never tested the operations with patients. Almost all of the FES devices available implement only open-loop, sensory triggered preprogrammed sequences of stimulation. The suggestion is that the improvements in the FES devices need better controllers which consider the overall status of the potential user, various effects that stimulation has on afferent and efferent systems, reflexive responses to the FES and direct responses to the FES by non-stimulated sensory-motor systems, and the greater integration of the biological control.

scholarly journals SI-HCCI Mode Transitions Without Open-Loop Sequence Scheduling: Control Architecture and Experimental Validation

2017 ◽  
Vol 139 (8) ◽  
Author(s):  
Patrick Gorzelic ◽  
Anna Stefanopoulou ◽  
Jeff Sterniak
Keyword(s):  
Control Method ◽  
Open Loop ◽  
Control Architecture ◽  
Load Range ◽  
Operating Condition ◽  
Gasoline Engines ◽  
Model Based ◽  
Transition Strategies ◽  
Feedback Control Method ◽  
Mode Transitions

This paper describes a model-based feedback control method to transition from spark ignition (SI) to homogeneous charge compression ignition (HCCI) combustion in gasoline engines. The purpose of the control structure is to improve robustness and reduce calibration complexity by incorporating feedback of the engine variables into nonlinear model-based calculations that inherently generalize across operating points. This type of structure is sought as an alternative to prior SI-HCCI transition approaches that involve open-loop calibration of input command sequences that must be scheduled by operating condition. The control architecture is designed for cam switching type SI-HCCI mode transition strategies with practical two-stage cam profile hardware, which previously have only been investigated in a purely open-loop framework. Experimental results on a prototype engine show that the control architecture is able to carry out SI-HCCI transitions across the HCCI load range at 2000 rpm engine speed while requiring variation of only one major set point and three minor set points with operating condition. These results suggest a noteworthy improvement in controller generality and ease of calibration relative to previous SI-HCCI transition approaches.

Steady-state and transient control strategies for a two-stage turbocharged diesel engine

2017 ◽  
Vol 232 (9) ◽  
pp. 1167-1179 ◽  
Author(s):  
Zhilong Hu ◽  
Kangyao Deng ◽  
Yi Cui ◽  
Xinxin Yang ◽  
Baochuan Zhang
Keyword(s):  
Steady State ◽  
Transient Response ◽  
Closed Loop ◽  
Control Strategies ◽  
Open Loop ◽  
Two Stage ◽  
Loop Control ◽  
Turbocharging System ◽  
Transient Control ◽  
Response Performance

Two-stage turbocharging technology is widely used to achieve higher engine power density and lower exhaust emissions. To solve a series of contradictions in matching, a regulated two-stage (RTS) turbocharging system is applied to reasonably control boost pressure. This paper investigated steady-state and transient control strategies for an RTS turbocharging system to achieve optimum fuel economy in steady-state conditions and better performance in transient conditions. The economic control strategies for steady-state operational conditions were based on an economic regulation law, which was established by a steady-state test of an engine with an RTS turbocharging system under all operating conditions. To optimize the transient performance, open-loop and closed-loop control systems (the latter with dynamic judgement) for the RTS system were designed and validated with experiments on a heavy-duty diesel engine. The experimental results demonstrated that the open-loop control strategy and the closed-loop strategy with dynamic judgement could improve the transient response performance. The optimum transient response performance was achieved by the closed-loop control system with dynamic judgement. Additionally, the combination of steady-state and transient control strategies could achieve the best fuel economy in steady-state conditions and good transient response performances.

Model-Based Control of a Pressure-Compensated Directional Valve With Significant Dead-Zone

2019 ◽  
Author(s):  
Santeri Lampinen ◽  
Janne Koivumäki ◽  
Jouni Mattila ◽  
Jouni Niemi
Keyword(s):  
Control Method ◽  
Dead Zone ◽  
Open Loop ◽  
Mobile Manipulators ◽  
Hydraulic Systems ◽  
Loop Control ◽  
Model Based Control ◽  
Control Valves ◽  
Model Based ◽  
Directional Control

Abstract Hydraulic systems on mobile manipulators and industrial systems often come equipped with pressure-compensated proportional directional control valves with significant dead-zone. These kind of hydraulic valves are well suited for open-loop applications with an operator in control. However, designing closed-loop control for such systems is a challenging task. In this study, we propose a model-based control method for such valves to increase the performance of the current state-of-the-art in industrial robotic manipulator control. The proposed control method rigorously addresses the dynamics of a hydraulic manipulator system with dead-zone compensation for pressure-compensated directional control valves. The proposed method is evaluated with experiments on a commercial heavy-duty breaker boom with Sauer-Danfoss PVG 120 valves. The experimental results show accurate control of the manipulator despite the used slow-response load sensing valves.

Sign in / Sign up

Export Citation Format

Share Document