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.

Nano Scale Material Property Measurement of MEMS Material Using Piezo Actuated Material Testing Machine

2006 ◽  
Vol 510-511 ◽  
pp. 734-737
Author(s):  
Hye Jin Lee ◽  
Nak Kyu Lee ◽  
Hyoung Wook Lee ◽  
Hoon Jae Park ◽  
Tae Hoon Choi
Keyword(s):  
Material Properties ◽  
Control Method ◽  
Testing Machine ◽  
Open Loop ◽  
Research Field ◽  
Piezo Actuator ◽  
Loop Control ◽  
Nano Scale ◽  
Feedback Control Method ◽  
Material Testing Machine

Many micro technology researches have been concentrated in the field of materials and a process field. But the properties of micro materials should be understood to give still more advanced results. Among the various material properties, mechanical material properties such as tensile strength, elastic modulus, etc., is the basic property. To measure mechanical properties in micro or nano scale, actuating must be very precise. Piezo is a famous actuator, frequently used to measure very precise mechanical properties in micro research field. But piezo has a nonlinearity called hysteresis. Not precision result is caused because of this hysteresis property in piezo actuator. Therefore feedback control method is used in many researches to prevent this hysteresis of piezo actuator. Feedback control method produces a good result in processing view, but causes a loss in a resolution view. In this paper, hysteresis is compensated by using an open loop control method. To apply the open loop control method to piezo actuated nano scale material testing machine, hysteresis property is modeled in a mathematical function, and a compensated control input is constructed using inverse function of original data. The reliability of this control method can be confirmed by testing nickel, aluminum, and copper micro thin foil that is used in MEMS material broadly. If these MEMS material properties are used in a MEMS research field, more economical and high performance MEMS materials can be obtained.

A Low-Order HCCI Model Extended to Capture SI-HCCI Mode Transition Data With Two-Stage Cam Switching

2014 ◽  
Author(s):  
Patrick Gorzelic ◽  
Prasad Shingne ◽  
Jason Martz ◽  
Anna Stefanopoulou ◽  
Jeff Sterniak ◽  
...  
Keyword(s):  
Steady State ◽  
Extreme Conditions ◽  
Mode Transition ◽  
Two Stage ◽  
Model Based Control ◽  
Model Based ◽  
Hcci Combustion ◽  
Transition Strategies ◽  
Mode Transitions ◽  
Low Order

A low-order homogeneous charge compression ignition (HCCI) combustion model to support model-based control development for spark ignition (SI)/HCCI mode transitions is presented. Emphasis is placed on mode transition strategies wherein SI combustion is abruptly switched to recompression HCCI combustion through a change of the cam lift and opening of the throttle, as is often employed in studies utilizing two-stage cam switching devices. The model is parameterized to a steady-state dataset which considers throttled operation and significant air-fuel ratio variation, which are pertinent conditions to two-stage cam switching mode transition strategies. Inspection and simulation of transient SI to HCCI (SI-HCCI) mode transition data shows that the extreme conditions present when switching from SI to HCCI can cause significant prediction error in the combustion performance outputs even with the model’s adequate steady-state fit. When a correction factor related to residual gas temperature is introduced to account for these extreme conditions, it is shown that the model reproduces transient performance output time histories in SI-HCCI mode transition data. The model is thus able to capture steady-state data as well as transient SI-HCCI mode transition data while maintaining a low-order cycle to cycle structure, making it tractable for model-based control of SI-HCCI mode transitions.

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 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.

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.

scholarly journals SI–HCCI Mode Transitions Without Open-Loop Sequence Scheduling: Online Parameter Adaptation

2017 ◽  
Vol 139 (8) ◽  
Author(s):  
Patrick Gorzelic ◽  
Anna Stefanopoulou ◽  
Jeff Sterniak
Keyword(s):  
Adaptive Method ◽  
Open Loop ◽  
Model Parameters ◽  
Parameter Adaptation ◽  
Transition Control ◽  
Model Based ◽  
Loop Sequence ◽  
Before And After ◽  
Mode Transition Control ◽  
Mode Transitions

A parameter adaptation method for a previously developed spark ignition (SI) to homogeneous charge compression ignition (HCCI) combustion mode transition control architecture is described. The goal of the adaptive method is to use transient SI–HCCI transition data gathered in online operation to tune the controller model parameters on a cylinder individual basis, in order to improve the accuracy of the controller's model-based calculations and account for cylinder to cylinder variability and drifts over time. The parameter adaptation is implemented on an experimental engine in an indirect adaptive control structure where the model parameters of the SI–HCCI transition controller are updated based on real-time measurements and used in subsequent model-based calculations. Comparison of SI–HCCI transition responses before and after adaptation at a single operating condition shows notable benefits from use of the adaptive method. When tested at differing operating points, the performance of the adapted controller remains overwhelmingly favorable to that of the baseline controller even when conditioned on data from only a single operating point.

Model-based control of the substrate concentration in an aeration basin using the wastewater level

1998 ◽  
Vol 37 (12) ◽  
pp. 335-342 ◽  
Author(s):  
Jacek Czeczot
Keyword(s):  
Substrate Concentration ◽  
Consumption Rate ◽  
Least Square Method ◽  
Estimation Procedure ◽  
Adaptive Controller ◽  
Open Loop ◽  
Least Square ◽  
Substrate Consumption ◽  
Model Based ◽  
Effluent Flow Rate

This paper deals with the minimal-cost control of the modified activated sludge process with varying level of wastewater in the aerator tank. The model-based adaptive controller of the effluent substrate concentration, basing on the substrate consumption rate and manipulating the effluent flow rate outcoming from the aerator tank, is proposed and its performance is compared with conventional PI controller and open loop behavior. Since the substrate consumption rate is not measurable on-line, the estimation procedure on the basis of the least-square method is suggested. Finally, it is proved that cooperation of the DO concentration controller with the adaptive controller of the effluent substrate concentration allows the process to be operated at minimum costs (low consumption of aeration energy).

scholarly journals Design of a Laparoscopic Robot System Based on Spherical Magnetic Field

2019 ◽  
Vol 9 (10) ◽  
pp. 2070
Author(s):  
Hongxing Wei ◽  
Kaichao Li ◽  
Dong Xu ◽  
Wenshuai Tan
Keyword(s):  
Magnetic Field ◽  
Control Method ◽  
Open Loop ◽  
Surgical Instruments ◽  
Prototype System ◽  
Single Incision Laparoscopic Surgery ◽  
Robot System ◽  
Surgical Incision ◽  
Spherical Motor ◽  
External Driving

In single incision laparoscopic surgery (SILS), because the laparoscope and other surgical instruments share the same incision, the interferences between them constrain the dexterity of surgical instruments and affect the field of views of the laparoscope. Inspired by the structure of the spherical motor and the driving method of an intraocular micro robot, a fully inserted laparoscopic robot system is proposed, which consists of an inner laparoscopic robot and external driving device. The position and orientation control of the inner laparoscopic robot are controlled by a magnetic field generated by the driving device outside the abdominal wall. The instrumental interferences can be alleviated and better visual feedback can be obtained by keeping the laparoscopic robot away from the surgical incision. To verify the feasibility of the proposed structure and explore its control method, a prototype system is designed and fabricated. The electromagnetism model and the mechanical model of the laparoscopic robot system are established. Finally, the translational, rotational, and deflection motion of the laparoscopic robot are demonstrated in practical experiment, and the accuracy of deflection motion of the laparoscopic robot is verified in open-loop condition.

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