Throttle Control Research Articles

Application of pressure reducing and throttle control valves for optimal pressure management in water distribution networks

ABSTRACT Advanced pressure control facilitates the smart management of water distribution networks (WDNs). In this study, an optimization-based method is proposed to develop a time-based schedule for pressure reducing valves (PRVs). For this purpose, a single-objective optimization problem is initially delineated, seeking to minimize spatiotemporal variations in the nodal pressures. Then, the application of PRVs is addressed in two scenarios, viz. individual (i.e. employing PRVs) and hybrid (i.e. the combined use of PRVs and throttle control valves [TCVs]). The proposed scenarios are subsequently applied to the hydraulic model of synthetic and real WDNs. A set of hydraulic evaluation indices, including variation index (VI), are further measured to spot the optimal pressure management scenario. The study results establish that the hybrid scenario leads to a larger decrease in the VI along with more efficient pressure control (namely, 39.9% and 11.8% in the synthetic and real WDNs, respectively), compared with the individual one.

Structural Optimization Design of Throttle Valve Core for Intelligent Layered Polymer Injection String Controlled By Cable

Optimization Design of Throttling Valve Core Structure for Wired Intelligent Layered Polymer Injection String : Wired intelligent layered polymer in-jection technology can improve the coverage of polymer flooding, alleviate inter-layer conflicts in reservoir development, and improve crude oil recovery. It is an important component of tertiary oil recovery. However, the layered polymer in-jection technology currently used in most domestic oilfields is still the method of fishing and changing the injection nozzle for testing and adjustment. The alloca-tion efficiency of injection volume testing for each layer is slow, with large er-rors, and it is impossible to monitor polymer injection parameters throughout the process. To this end, research has been carried out on the cable controlled intelli-gent layered polymer injection string. By optimizing a highly efficient and low viscosity loss streamlined layered polymer injection throttling device with contin-uously adjustable gaps, the adjustment stroke is shorter and the measurement and adjustment efficiency is higher. Using finite element simulation, the low shear throttle control unit was studied and optimized. By moving the polymer core up and down slightly in the axial direction, the relative gap between the polymer core and the working cylinder was changed to achieve flow adjustment. At the same time, it is necessary to complete the direct reading measurement and adjustment process to form a single pipe layered polymer injection measurement and adjust-ment integration technology. The cable controlled intelligent layered polymer in-jection matching technology connects with the ground intelligent control system through cables to achieve realtime monitoring and online control of polymer flow, pressure, temperature, and other parameters, improving monitoring accura-cy and efficiency, and providing technical support for the construction of the “Digital Intelligence Oilfield”.

Self-Tuning Backstepping Control with Kalman-like Filter for High-Precision Control of Automotive Electronic Throttle

The automotive electronic throttle (AET) control system has been widely applied in modern automotive engines, and accurate control of AET can improve engine performance as well as reduce pollution emissions. However, the noise in the sensor circuit and the variation in automotive driving conditions seriously affect the control performance of the AET system, making controller designing challenging. This paper proposes a self-tuning backstepping control with a Kalman-like filter (SBCKLF) strategy. First, the noise affecting the position sensor measurement is verified to be non-Gaussian by acquiring and processing the noise signal. To eliminate its influence on control precision, a Kalman-like filter is introduced to estimate the real position of the valve. Then, a self-tuning backstepping controller is designed to automatically adapt to the variation in vehicle driving conditions. A self-tuning algorithm based on fuzzy control is used to tune the parameters of the backstepping controller online, so as to optimize the controller performance. Finally, an experimental platform based on dSPACE for the AET control system is built to perform the controller comprehensive test in a real-time environment. Experimental results and performance analysis demonstrate the effectiveness of the proposed SBCKLF strategy. Compared to the best results of other methods, the proposed method reduces the maximum and root mean square tracking errors by 21.65% and the average error by 12.89%. The steady-state and tracking error bounds are controlled to 0.9° and 2.3°, respectively. It also shows that the SBCKLF strategy has the strongest robustness as well as the best response speed.

A Novel Adaptive Control Scheme for Automotive Electronic Throttle Based on Extremum Seeking

To achieve rapid and high-precision servo control of an electronic throttle, an adaptive control scheme is proposed based on the extremum seeking (ES), which consists of a variable-gain adaptive proportional-integral (ES-API) controller and an adaptive compensator (ES-ACP). The two gains ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${K_p}$</tex-math> </inline-formula> , <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${K_i}$</tex-math> </inline-formula> ) of the ES-API controller are designed as maps with respect to the tracking error, and the parameters of these maps are learned by ES. Additionally, the ES-ACP is applied to compensate for the strong nonlinearity inherent in an electronic throttle control (ETC) system, whose parameters are also learned by ES. During parameter learning, an objective function is utilized to quantify the tracking error of the opening angle of the electronic throttle plate, and then the parameters are learned using a step reference signal and a ramp reference signal. ES optimizes the above parameters by reducing the objective function to achieve a more favorable tracking response. Five reference signals are used to evaluate the learned controller after the parameter learning process is completed. Experiments were performed on a test bench equipped with an electronic throttle, and the experimental results show that the control scheme is capable of tracking multiple reference trajectories quickly and accurately.

Multimode operation control strategy for improving part-load performance of supercritical CO2 Brayton cycle

The recompression supercritical CO2 (S-CO2) Brayton cycle is regarded as one of the most promising energy conversion systems owing to its high efficiency and compactness. Because the recompressor impairs the performance of a system at low loads, the concept of multimode operation by switching the recompressor on or off is proposed to improve the part-load performance. In this study, a dynamic model of the recompression S-CO2 cycle with reheating is developed, and three control strategies, including turbine throttle valve control, turbo-alternator-compressor (TAC) speed control, and inventory control, are selected to follow the part-load. Subsequently, the action mechanism of the multimode operation and the effects of different control strategies on the part-load performance of the system under multimode operation is investigated and compared. Simulation results indicate that the improved thermal efficiency by switching operation modes is due to improvement in the thermal match inside the high-temperature recuperator and reduced degradation of the recompressor. Moreover, switching the system to Mode 2 by switching off the recompressor at 20% load under TAC speed control, turbine throttle valve control, and inventory control can improve thermal efficiency by 1%, 3.5%, and 5.4%, respectively. This result can serve as a guideline for the efficient operation of the recompression cycle under part-load.

Simulation and Regulation of Sustainable Utilization of Water Resources in China Based on Improved Water Resources Ecological Footprint Model

The original ecological footprint model of water resources was improved here to explore the rational policy of water resources development and utilization. Aiming to address the problems of high complexity, weak applicability, and insufficient systematicness and dynamics of the existing water resources ecological footprint model, the grey water footprint was introduced into the model to quantify the water for decontamination. In the calculation of the water resources ecological footprint index, the rainwater collection project, seawater desalination, and water resources regeneration, unconventional water sources were considered, and when combined with the system dynamics simulation technology, the SD model of water resources sustainable utilization in China was established. We carried out research on the regulation and control of sustainable utilization of water resources in China. The results showed that the development and utilization of water resources in China remained within the ecological carrying capacity as a whole from 2000 to 2017, and the development of water resources still had potential, but the supply and demand of water resources were unbalanced. Given this, from the perspective of throttling, open-source, and pollution control, six control schemes for sustainable utilization of water resources in China were set up, including the continuation of the current situation, green throttling, pollution control, strict planning for water source development, and comprehensive treatment. Among them, the comprehensive coordination plan for 2018-2050 could properly solve the problem of water resources supply and demand under the conditions of meeting the ecological sustainability of water resources and reasonable water resources load and was the best regulation plan to realize the sustainable utilization of water resources in China. At present, the development of water resources in China lags, which does not match the growth rate of social and economic development on water resources consumption. It is necessary to further strengthen the efforts of open-source, water-saving, and pollution control based on the original policies, so as to alleviate the ecological stress of water resources.

SMC for Discrete-Time Networked Semi-Markovian Switching Systems With Random DoS Attacks and Applications

This article concentrates on the discrete-time sliding mode control (DTSMC) problem for uncertain networked semi-Markovian switching systems (S-MSSs) under random denial-of-service (DoS) attacks. The semi-Markovian kernel (SMK) approach is utilized such that the switching among different modes is mutually governed by the transition probability and the sojourn-time distribution function. Considering randomly occurring DoS attacks, a sliding mode function related to the attack probability is constructed to analyze the impact of malicious attacks. Then, sufficient conditions under the equivalent DTSMC law are derived in view of the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sigma $ </tex-math></inline-formula> -error mean square stability criterion. Furthermore, the synthesis problem of the proposed DTSMC law ensures that the resulting closed-loop system dynamics can be driven onto the prespecified sliding region within a limited time. Finally, an electronic throttle control system is shown to validate the proposed algorithm.

Modelling and performance evaluation of a direct steam generation solar power system coupled with steam accumulator to meet electricity demands for a hospital under typical climate conditions in Libya

This study aims to build a dynamic model of a direct steam generation (DSG) solar power system coupled with a steam accumulator to meet electricity demands for a hospital under transient environmental conditions in Libya. The main components of the system are DSG parabolic trough collectors, a steam accumulator, a turbine, a condenser and a circulation pump. The system is modelled via using Simulink\\Simscape software blocks with integrated MATLAB functions to run a dynamic simulation. As the simulation tool reflects the transient operation of the components, advanced control strategies were applied to the model. Using the proportional integral controller (PI controller), safe operation of the system is secured by pump flow rate control, safe turbine operation is provided by pressure control and power output is matched with the demand by using a throttle valve control. 1584 m2 solar collector area and 160 m3 total volume of pressurized steam tank are used in the simulation considering the electricity demand of the hospital and solar radiation in the location. The produced work output was controlled to match the demand profile of the hospital, which needs 200 kW in the peak period and 50 kW at the night. The designed system shows a maximum thermal efficiency of 23.5% for the operation condition.

Modeling and prediction of powered parafoil unmanned aerial vehicle throttle and servo controls through artificial neural networks

This study proposes a framework for developing a realistic model for throttle and servo control algorithms for a powered parafoil unmanned aerial vehicle (PPUAV) using artificial neural networks (ANNs). Two servo motors on an L-shaped platform, control and steer the PPUAV. Six degrees of freedom mathematical model of a dynamic parafoil system is built to test the technique's efficacy using a simulation in which disturbances mimic actual flights. A guiding law is then established, including the cross-track error and the line-of-sight approach. Furthermore, a path-following controller is constructed using the proportional-integral derivative, and a simulation platform was created to evaluate numerical data illustrating the route's validity following the technique. PPUAV was developed, built, and instrumented to collect real-time flight data to test the controller. These dynamic characteristics were sent into the ANN for training. A diverging-converging design was identified to obtain the best consistency between predicted and observed throttle and servo control values. For a comparable flight route, the control signal of the simulated model is compared with those of the actual and ANN-predicted models. The comparative findings show that the ANN-predicted and actual control inputs were almost identical, with an 80%–99% match. However, the simulated response showed deviation from the actual control input, with an accuracy of 50%–80%.

Time-Fuel-Optimal Navigation of a Commercial Aircraft in Cruise With Heading and Throttle Controls Using Pontryagin’s Maximum Principle

In this research, we consider the commercial aircraft trajectory optimization problem for a general cruise model with arbitrary spatial wind fields to be solved using the Pontryagin’s maximum principle. The model features two fundamental controls, namely “throttle setting” (appearing as a singular control) and “heading angle” (appearing as a regular control). For a problem with state-inequality constraints and minimum time-fuel objective, we show that the optimal “heading angle” can be described through the classic Zermelo’s navigation identity. We also demonstrate, by analyzing the switching function, that the singular “throttle setting” can be characterized through a feedback function that relies on both the optimal states and “heading angle”. The switching-point algorithm is employed to solve a case study where we inspect the optimality conditions and graph the optimal controls together with the optimal state and co-state variables.

Design and Experimental Analysis of an Adaptive Second-Order Fast Non-Singular Terminal Sliding Mode Controller for Electronic Throttle With Disturbance

Design and Experimental Analysis of an Adaptive Second-Order Fast Non-Singular Terminal Sliding Mode Controller for Electronic Throttle With Disturbance

Разработка математической модели процессов в газогенераторе с унитарным топливом для питания турбины жидкостной ракетной двигательной установки

The article considers the dynamic model of a gas generator with control throttle of liquid rocket engine with pumping supply system and unitary fuel for powering the turbine. The system of dynamic equations describing the processes occurring in a single-component gas generator and a throttle valve is obtained. The mathematical model makes it possible to analyze and identify the main patterns of the influence of input quantities on the controlled quantity.

Аnalysis of energy saving methods servic-ing airfields and airplanes

Problem. The problem is an integral part of developing the concept of forming a standard range of transport and technological hydrophilic modular means for maintenance of airfields and aircraft. Goal. The goal is development of scientifically sound recommendations for determining the rational parameters of the hydraulic system with automation of control and energy saving during operation of modular vehicles for maintenance of airfields and aircraft, taking into account the potential of domestic engineering and critical imports of units and assemblies. Methodology. The methods include analysis of energy saving methods in hydraulic fluid power of mobile machines according to manufacturers' catalogs and industrial examples taking into account the needs of modular vehicles for maintenance of airfields and aircraft, in particular, taking into account the creation of modern hydraulic devices and circuit solutions in hydraulic drives with throttle and machine control and automatic regulators of change of hydraulic fluid power. Results. It is established that in hydraulic drives with throttle control and pumps with unregulated working volume, throttles on parallel flow and three-wire flow regulators or LS and LUDV modern systems are used; automatic pressure and flow regulators are used with pumps with adjustable displacement; in machine-controlled hydraulic drives through the use of pumps and hydraulic motors with adjustable displacement and hydraulic automation; by energy recovery during operation and bench tests of hydraulic drives; at the design stage of hydraulic drives, when the static analysis is performed in terms of efficiency and dynamic to reduce the loads on the starting modes of operation; and also at designing lay the effective circuit technical decisions promoting energy saving; directly in operation due to high-quality working fluids, heat exchange systems and filtration. Originality. The classification of methods of energy saving in volumetric hydraulic drives of mobile machines is made and examples of application of some means which are planned for introduction in transmissions and the technological equipment of cars for service of aerodromes and planes are resulted. Practical value. The possibility of a rational selection of axial-piston domestic hydraulic machines for the development of hydraulic drives for airfields and aircraft is proven.

Analysis of modern technical means for servicing airports and airplanes

Problem. The problem is an integral part of developing the concept of forming a standard range of transport and technological hydrophilic modular means for maintenance of airfields and airplanes. Goal. The goal is development of scientifically sound recommendations for determining the rational parameters of the hydraulic system with automation of control and energy saving during operation of modular vehicles for maintenance of airfields and aircraft, taking into account the potential of domestic engineering and critical imports of units and assemblies. Methodology. The methods include analysis of energy saving methods in hydraulic fluid power of mobile machines according to manufacturers' catalogs and industrial examples taking into account the needs of modular vehicles for maintenance of airfields and aircraft, in particular, taking into account the creation of modern hydraulic devices and circuit solutions in hydraulic drives with throttle and machine control and automatic regulators of change of hydraulic fluid power. Results. It is established that in hydraulic drives with throttle control and pumps with unregulated working volume, throttles on parallel flow and three-wire flow regulators or LS and LUDV modern systems are used; automatic pressure and flow regulators are used with pumps with adjustable displacement; in machine-controlled hydraulic drives through the use of pumps and hydraulic motors with adjustable displacement and hydraulic automation; by energy recovery during operation and bench tests of hydraulic drives; at the design stage of hydraulic drives, when the static analysis is performed in terms of efficiency and dynamic to reduce the loads on the starting modes of operation; and also at designing lay the effective circuit technical decisions promoting energy saving; directly in operation due to high-quality working fluids, heat exchange systems and filtration. Originality. The classification of methods of energy saving in volumetric hydraulic drives of mobile machines is made and examples of application of some means which are planned for introduction in transmissions and the technological equipment of cars for service of aerodromes and planes are resulted. Practical value. The possibility of a rational selection of axial-piston domestic hydraulic machines for the development of hydraulic drives for airfields and aircraft is proven.

Efficiency Improvement of Nonlinear Compressor System with Robust MIMO Reset Approach

In this study, a control design of the compressor system is analysed in order to demonstrate its characteristics and to improve efficiency. The state space model is constructed by the Moore-Greitzer nonlinear equations. Upstream flow acts as a control loop disorder and the compressor system cannot meet the requirements with flow variance, so it is essential that the controller adapts to the new conditions. Because the control signal is connected to the system output by a nonlinear model, a reset controller is used to control the compressor system. A robust reset controller has designed consistent with the PI + CI method. The robust controller is designed as multi-input-multi-output and uses two throttle control valve and close-coupled valve actuators to apply control signals. Two reset controllers with a harmonious combination in the structure of the compressor system provide the possibility of following the desired pressure and flow states. The proposed controller can stabilize the compressor and increase its efficiency in the event of any disturbance in addition to preventing surge instability. The simulation results show that the reset controller can provide good performance. It is proved that the convergence rate changes with changes in the controller parameters. Finally, the stability of the controller is examined under the most severe conditions.

Virtual Time III, Part 1: Unified Virtual Time Synchronization for Parallel Discrete Event Simulation

Algorithms for synchronization of parallel discrete event simulation have historically been divided between conservative methods that require lookahead but not rollback, and optimistic methods that require rollback but not lookahead. In this paper we present a new approach in the form of a framework called Unified Virtual Time (UVT) that unifies the two approaches, combining the advantages of both within a single synchronization theory. Whenever timely lookahead information is available, a logical process (LP) executes conservatively using an irreversible event handler. When lookahead information is not available the LP does not block, as it would in a classical conservative execution, but instead executes optimistically using a reversible event handler. The switch from conservative to optimistic synchronization and back is decided on an event-by-event basis by the simulator, transparently to the model code. UVT treats conservative synchronization algorithms as optional accelerators for an underlying optimistic synchronization algorithm, enabling the speed of conservative execution whenever it is applicable, but otherwise falling back on the generality of optimistic execution. We describe UVT in a novel way, based on fundamental invariants, monotonicity requirements, and synchronization rules. UVT permits zero-delay messages and pays careful attention to tie-handling using superposition. We prove that under fairly general conditions a UVT simulation always makes progress in virtual time. This is Part 1 of a trio of papers describing the UVT framework for PDES, mixing conservative and optimistic synchronization and integrating throttling control.

3D printed custom gas cam for race bike application using Progrip® lock on grips mod.708

Background: The “drive by wire” mechanism for managing the throttle is not applied to every modern motorcycle, but it is often managed through a steel wire. Here, there is a cam on the throttle control. Its shape allows the throttle opening to be faster or slower and its angle of rotation, required for full opening, to be greater or less. The maximum angle a rider's wrist can withstand depends on numerous musculoskeletal mobility factors, often limited by falls or surgery. Methods: Using a Progrip knob with interchangeable cams allows the customization of a special cam profile, to ensure the best engine response to throttle rotation and ergonomics for the rider. The use of FEA software and lattice structures, allows to realize a lightweight and efficient design, targeted for fabrication with additive manufacturing technologies. Results: The cam was manufactured by exploiting MSLA technology. Finally, a dimensional inspection procedure was performed before assembly. The main result is to have obtained a lighter and cheaper component than the original. Conclusions: This study has allowed the design of a mechanical component consisting of innovative shape, light weight, and ergonomics. Furthermore, it demonstrates the effectiveness in the use of lattice structures to enable weight optimization of a component while minimizing the increase in its compliance.

Experimental investigation on the start-up behaviors of a Joule–Thomson refrigeration system with pressure control

• Start-up behaviors of the J-T refrigeration system with pressure control were explored. • Reducing the pressure control time could accelerate pull-down rate. • Increasing control pressure and expansion valve opening decreases pull-down time. • Reducing compressor speed and R1150 concentration could reduce pull-down time. The excessively high discharge pressure of mixture-based Joule–Thomson (J–T) refrigeration system for low-temperature freezers at the start-up process without active control leads to the reduction of operation reliability of compressors. Start-up characteristics of a J–T refrigeration system with an expansion tank for pressure control were investigated in this study. The binary mixture R1150/R600a was selected as the working fluid, and influences of the control pressure, compressor speed, throttle valve opening, and mixture concentration on the system’s dynamic performances were experimentally explored. Results demonstrated that the discharge pressure could be effectively limited below the compressor’s safety pressure with an expansion tank. Meanwhile, the close relationship between pull-down rate and time of the pressure control phase was associated with the control pressure, compressor speed, throttle valve opening, and mixture concentration. The pull-down rate can be accelerated by increasing the control pressure and throttle valve opening and reducing the compressor speed and the R1150 concentration at the start-up process. The excessively rich R1150 concentration caused the continuous action of the pressure switch and the malfunction of the low-temperature freezing at an acceptable time range. The build-up of the heat recuperation played a significant role in pressure control time and freezing temperature reduction rate.

Real time hardware implementation of discrete sliding mode fuzzy controlled buck converter using digital signal processor

This paper deals with the real time hardware implementation of discrete sliding mode fuzzy control (DSMFC) for buck converter using digital signal processor (DSP). Applications like electric vehicle suspension control, flight dynamic control, robot position control and engine throttle position control; sliding mode control (SMC) plays a major role. Hardware realization is difficult with SMC strategy due to the continuous gain change results in chattering problem and actuator or contact may break. To resolve this problem the fuzzy logic (FL) approach has combined with the robust technique discrete sliding mode control (DSMC) to develop a new strategy for DSMFC. The mathematical modeling of the controller is done using MATLAB/Simulink software and practical design of the converter is also realized. The robustness of the controller is proved by introducing sudden change in input voltage as well as load with the help of switching circuit in hardware realization. The obtained practical results are verified by comparing with the simulation output and reference value.

Investigation of Motorcycle Handle Vibration Attenuation using a Suspended Handlebar with Different Rubber Mount Characteristics

Motorcycle riders are exposed to prolonged hand-transmitted vibration that can lead to hand numbness and trembling and, in extreme cases, disorders such as the Hand-arm Vibration syndrome (HAVs). The vibration of a motorcycle handle is the result of two major excitation forces, namely the engine vibration and the road-tire vibration. Operating the engine throttle control requires the rider to grip and twist the throttle handle which in turn provides a good vibration transmission path from the handle to the hand. The on-road measurement of hand-arm vibration (HAV) in a rider of an underbone single-cylinder motorcycle show a relatively high value of HAV, with a_hv of 8.28m/s^2. One feasible solution is to attenuate the handlebar vibration transmissibility, by using rubber mounts to create a suspended handlebar. In this study, based on Experimental Modal Analysis (EMA), a hand gripped modal model of the handlebar is developed, and the evaluation is done on the frequency responses of different handlebar designs. The selection criterion is based on the frequency response function (FRF) synthesis index (area under curve) and in this work the area under FRF curve is taken for frequency range of 0 ? 200Hz based on the HAV system. Order analysis of the handle vibration showed higher acceleration level in the z-axis (vertical) compared to the y-axis (horizontal) and for the on-road testing produces, much higher vibration level is determined compared to engine-related vibration due to the tire-road interaction. The suspended handlebar with the best performance is selected for actual on-the-road test, and the result shows a lower a_hv value of 4.08m/s^2 (51% reduction), which significantly increases the vibration exposure limit value (EAV) time from 44 minutes to 3 hours.