Control Engineering of China Special Issue on "Control Systems Engineering"

Control systems contribute to every aspect of modem society.In our life control systems exist in almost everywhere such as toasters,VCRs and smart phones.In science and technology,control systems already have widespread applications,for example,steering ships,guiding missiles and driving driverless cars in the near future.In all the control systems,systems are the key platform where control should be put into.It is at the system level that control shows its values.Extracting and formulating

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Raman Scattering Modification in Monolayer ReS_2 Controlled by Strain Engineering

Regulation of optical properties and electronic structure of two-dimensionM layered ReS2 materials has attracted much attention due to their potential in electronic devices. However, the identification of structure transformation of monolayer ReS2 induced by strain is greatly lacking. In this work, the Raman spectra of monolayer ReS2 with external strain are determined theoretically based on the density function theory. Due to the lower structural symmetry, deformation induced by external strain can only regulate the Raman mode intensity but cannot lead to Raman mode shifts. Our calculations suggest that structural deformation induced by external strain can be identified by Raman scattering.

Evaluation of Environmental Sound Pressure Level,Drawing of Noise-Isosonic Map Using Surfer V.19,and Prioritization of Engineering Noise Control Methods Using the Analytic Hierarchy Process(AHP):A Field Study in CGS Stations

Noise pollution is one of the most significant harmful physical factors in the industrial and occupational environments.Due to the high costs of exposure to excessive noise;continuous sound evaluation,propose and implement noise control plans in occupational environments is necessary.Thus,the present study aimed to review environmental sound measurements,drawing of noise maps,and prioritizing the engineering noise control methods using the Analytic Hierarchy Process(AHP).This study was a descriptive-analytical study that aimed to assess occupational noises and present a control plan in the City Gas Stations(CGSs)of Kerman,Iran in 2021.The present study was done in two phases.In the first phase,six CGSs were investigated to measure and evaluate the noise.In addition,the noise map of a CGS was drawn using the Surfer software.Finally,the AHP was used in the second phase of the research to prioritize the control measures.In this phase,four criteria and ten alternatives were identified.According to first phase results,the sound pressure level(SPL)of the stations varied from 76 to 98 dBA.Besides,the majority of the studied stations had a sound level higher than 85 dBA(danger zone).The second phase of the study showed that out of the four evaluated criteria,the executability criterion had the highest impact and the cost criterion had the lowest impact on the selection of control measures with a weight of 0.587 and 0.052,respectively.Based on the results of prioritization of the alternatives,using a silenced regulator(weight of 0.223)and increasing the thickness of the tube(weight of 0.023)had the highest and lowest priorities among the alternatives,respectively.The use of engineering noise control methods such as using silenced regulators was the best way to control the noises of CGSs.Additionally;it is noteworthy that AHP is a practical method for prioritizing alternatives to achieve the most accurate decision-making.The results of AHP can be of great help to health and safety experts and managers in choosing the sound engineering control measures more precisely.

Optimization of Engine Control Strategies for Low Fuel Consumption in Heavy-Duty Commercial Vehicles

The reduction of fuel consumption in engines is always considered of vital importance.Along these lines,in this work,this goal was attained by optimizing the heavy-duty commercial vehicle engine control strategy.More specifically,at first,a general first principles model for heavy-duty commercial vehicles and a transient fuel consumptionmodel for heavy-duty commercial vehicles were developed and the parameters were adjusted to fit the empirical data.The accuracy of the proposed modelwas demonstrated fromthe stage and the final results.Next,the control optimization problem resulting in low fuel consumption in heavy commercial vehicles was described,with minimal fuel usage as the optimization goal and throttle opening as the control variable.Then,a time-continuous engine management approach was assessed.Next,the factors that influence low fuel consumption in heavy-duty commercial vehicles were systematically examined.To reduce the computing complexity,the control strategies related to the time constraints of the engine were parametrized using three different methods.The most effective solution was obtained by applying a global optimization strategy because the constrained optimization problem was nonlinear.Finally,the effectiveness of the low-fuel consumption engine control strategy was demonstrated by comparing the simulated and field test results.

Fuzzy controller design for networked control system with time-variant delays

Networked control system is new hot-point in control engineering. A new delayed model for networked control systems is presented, based on which an LQR controller is designed. A method of delays estimation online is also given. For the difficulty on implementation of LQR in NCSs with time-variant delays, the Mamdani intelligent logic with LQR controller is addressed. The stability of the networked control system is also given. Simulation results prove that the novel controller can make the system stable and robustly preserve the performance in terms of time-variant delays.

Control Algorithm of Electric Vehicle in Coasting Mode Based on Driving Feeling

Coasting in gear is a common driving mode for the conventional vehicle equipped with the internal combustion engine（ICE）, and the assistant braking function of ICE is utilized to decelerate the vehicle in this mode. However, the electric vehicle（EV） does not have this feature in the coasting mode due to the relatively small inertia of the driving motor, so it will cause the driver cannot obtain the similar driving feeling to that of the conventional vehicle, and even a traffic accident may occur if the driver cannot immediately adapt to the changes. In this paper, the coasting control for EV is researched based on the driving feeling. A conventional vehicle equipped with continuously variable transmission（CVT） is taken as the reference vehicle, and the combined simulation model of EV is established based on AVL CRUISE and MATLAB/Simulink. The torque characteristic of the CVT output shaft is measured in coasting mode, and the data are smoothed and fitted to a polynomial curve. For the EV in coasting mode, if the state of charge（SOC） of the battery is below 95%, the polynomial curve is used as the control target for the torque characteristic of the driving motor, otherwise, the required torque is replaced by hydraulic braking torque to keep the same deceleration. The co-simulation of Matlab/Simulink/Stateflow and AVL CRUISE, as well as the hardware-in-loop experiment combined with d SPACE are carried out to verify the effectiveness and the real-time performance of the control algorithm. The results show that the EV with coasting braking control system has similar driving feeling to that of the reference vehicle, meanwhile, the battery SOC can be increased by 0.036% and 0.021% in the initial speed of 100 km/h and 50 km/h, respectively. The proposed control algorithm for EV is beneficial to improve the driving feeling in coasting mode, and it also makes the EV has the assistant braking function.

APPLICATION OF CIRCUIT SIMULATION IN HARDWARE DESIGN FOR ELECTRONIC CONTROL HIGH PRESSURE COMMON-RAIL FUEL SYSTEM OF DIESEL ENGINE

By means of circuit simulation, hardware of electronic control unit （ECU） of high pressure common-rail electronic control fuel system for diesel engine is designed. According to the system requirements for hardware of ECU, signal-processing circuit of variable reluctance （VR） sensor, filter circuit for input signal, high voltage power circuit and driver and protection circuit of solenoid are simulated as emphases. Difficulties of wide scope of VR sensor output signal, efficiency of high voltage power and reliable and swift driver of solenoid are solved. The results of simulation show that the hardware meets the requirement of the fuel system. At the same time, circuit simulation can greatly increase quality of the design, alleviate design labor and shorten design time.

Novel Oxygen Storage Components Promoted Palladium Catalysts for Emission Control in Natural Gas Powered Engines

A three-way catalyst comprised novel oxygen storage components for emission control in natural gas powered engines was prepared. The addition of novel oxygen storage components to the Pd/γ-Al2O3 catalysts resulted in improved activities of the fresh and aged catalyst by lowering the light-off temperature for methane in natural gas engines exhaust.

SIMULATION IN THERMAL DESIGN FOR ELECTRONIC CONTROL UNIT OF ELECTRONIC UNIT PUMP

The high working junction temperature of power component is the most common reason of its failure. So the thermal design is of vital importance in electronic control unit （ECU） design. By means of circuit simulation, the thermal design of ECU for electronic unit pump （EUP） fuel system is applied. The power dissipation model of each power component in the ECU is created and simulated. According to the analyses of simulation results, the factors which affect the power dissipation of components are analyzed. Then the ways for reducing the power dissipation of power components are carried out. The power dissipation of power components at different engine state is calculated and analyzed. The maximal power dissipation of each power component in all possible engine state is also carried out based on these simulations. A cooling system is designed based on these studies. The tests show that the maximum total power dissipation of ECU drops from 43.2 W to 33.84 W after these simulations and optimizations. These applications of simulations in thermal design of ECU can greatly increase the quality of the design, save the design cost and shorten design time

Simulation of VGT control based on charge oxygen concentration

A turbocharged diesel engine model was built with the GT-Power software,and experimentally verified.Then two different control variables for the control of the variable geometry turbocharger（VGT）were described,and their distinct effects on engine performance,i.e.NOxand soot emissions and fuel consumption,were simulated and compared on the basis of this model.The results showed that NOxemissions decreased obviously with the increase of exhaust gas recirculation（EGR）rate at constant boost pressure condition,but soot emissions and fuel consumption considerably increased.It was a good way to reduce NOxemissions without increasing fuel consumption and soot emissions when VGT was controlled to maintain the excess oxygen ratio unchanged as EGR rate increases.

COMPOSITIVE EMISSION CONTROL SYSTEM OF GASOLINE VEHICLE

The working principle of a kind of compositive emission control system is inquired into, which includes exhaust heater, secondary air supplement, exhaust gas recirculation （EGR）, thermal reactor and catalytic converter, etc. The purification effect of CO, HC and NOx emission of the gasoline spark ignite （S.I.） engine is studied. The entire vehicle driving cycle tests based on the national emission standard and a series of the gasoline engine-testing bench tests including full load characteristic experiment, load characteristic experiment and idle speed experiment are done. The results show that the system has a very good emission control effect to CO, HC and NOx of gasoline engine. The construction of the system is very simple and can be mounted on the exhaust pipe conveniently without any alteration of the vehicle-use gasoline engine.

Nonlinear adaptive flight control system:Performance enhancement and validation

The problem of decreasing stability margins in L1 adaptive control systems is discussed and an out-of-loop L1 adaptive control scheme based on Lyapunov’s stability theorem is proposed.This scheme enhances the effectiveness of the adaptation,which ensures that the system has suffi-cient stability margins to achieve the desired performance under parametric uncertainty,additional delays,and actuator faults.The stability of the developed control system is demonstrated through a series of simulations.Compared with an existing control scheme,the constant adjustment of the sta-bility margins by the proposed adaptive scheme allows their range to be extended by a factor of 4–5,bringing the stability margin close to that of variable gain PD control with adaptively scheduled gains.The engineered practicability of adaptive technology is verified.A series of flight tests verify the practicability of the designed adaptive technology.The results of these tests demonstrate the enhanced performance of the proposed control scheme with nonlinear parameter estimations under insufficient stability margins and validate its robustness in the event of actuator failures.

Multiclassification algorithm and its realization based on least square support vector machine algorithm

As a new type of learning machine developed on the basis of statistics learning theory, support vector machine （SVM） plays an important role in knowledge discovering and knowledge updating by constructing non-linear optimal classifter. However, realizing SVM requires resolving quadratic programming under constraints of inequality, which results in calculation difficulty while learning samples gets larger. Besides, standard SVM is incapable of tackling multi-classification. To overcome the bottleneck of populating SVM, with training algorithm presented, the problem of quadratic programming is converted into that of resolving a linear system of equations composed of a group of equation constraints by adopting the least square SVM（LS-SVM） and introducing a modifying variable which can change inequality constraints into equation constraints, which simplifies the calculation. With regard to multi-classification, an LS-SVM applicable in multi-dassiftcation is deduced. Finally, efficiency of the algorithm is checked by using universal Circle in square and twospirals to measure the performance of the classifier.

Controllable Ni/NiO interface engineering on N-doped carbon spheres for boosted alkaline water-to-hydrogen conversion by urea electrolysis

Interface engineering has gradually attracted substantial research interest in constructing active bifunctional catalysts toward urea electrolysis.The fundamental understanding of the crystallinity transition of the components on both sides of the interface is extremely significant for realizing controllable construction of catalysts through interface engineering,but it still remains a challenge.Herein,the Ni/NiO heterogenous nanoparticles are successfully fabricated on the porous N-doped carbon spheres by a facile hydrothermal and subsequent pyrolysis strategy.And for the first time we show the experimental observation that the Ni/NiO interface can be fine-tuned via simply tailoring the heating rate during pyrolysis process,in which the crystalline/amorphous or crystalline/crystalline Ni/NiO heterostructure is deliberately constructed on the porous N-doped carbon spheres(named as CA-Ni/NiO@NCS or CC-Ni/NiO@NCS,respectively).By taking advantage of the unique porous architecture and the synergistic effect between crystalline Ni and amorphous NiO,the well-designed CA-Ni/NiO@NCS displays more remarkable urea oxidation reaction(UOR)and hydrogen evolution reaction(HER)activity than its crystalline/crystalline counterpart of CC-Ni/NiO@NCS.Particularly,the whole assembled two-electrode electrolytic cell using the elaborate CANi/NiO@NCS both as the anode and cathode can realize the current density of 10 mA·cm^(−2)at a super low voltage of 1.475 V(264 mV less than that of pure water electrolysis),as well as remarkable prolonged stability over 63 h.Besides,the H_(2)evolution driven by an AA battery and a commercial solar cell is also studied to enlighten practical applications for the future.

Protection against water or mud inrush in tunnels by grouting:A review

Grouting is a major method used to prevent water and mud inrush in tunnels and underground engineering. In this paper, the current situation of control and prevention of water and mud inrush is summarized and recent advances in relevant theories, grout/equipment, and critical techniques are introduced. The time-variant equations of grout viscosity at different volumetric ratios were obtained based on the constitutive relation of typical fast curing grouts. A large-scale dynamic grouting model testing system （4000 mm × 2000 mm × 5 mm） was developed, and the diffusions of cement and fast curing grouts in dynamic water grouting were investigated. The results reveal that the diffusions of cement grouts and fast curing grouts are U-shaped and asymmetric elliptical, respectively. A multi-parameter real-time monitoring system （＆#981; = 1.5 m, h = 1.2 m） was developed for the grouting process to study the diffusion and reinforcement mechanism of grouting in water-rich faulted zone. A high early strength cream-type reinforcing/plugging grout, a high permeability nano-scale silica gel grout, and a high-expansion filling grout were proposed for the control of water hazards in weak water-rich faulted zone rocks, water inrush in karst passages, and micro-crack water inrush, respectively. Complement technologies and equipment for industrial applications were also proposed. Additionally, a novel full-life periodic dynamic water grouting with the critical grouting borehole as the core was proposed. The key techniques for the control of water inrush in water-rich faulted zone, jointed fissures and karst passages, and micro-crack water inrush were developed.

STRATEGY FOR DIESEL ROTARY ENGINE WITH COMMON RAIL INJECTION SYSTEM

A direct injection low compression ratios diesel rotary engine is designed and studied to find the appropriate application of the electronic controlled high pressure common rail injection system. Current development focuses on the applied fuel injection and ignition strategies, especially concerning the combustion configurations of injectors, ignition source, and combustion chamber. The prototype engine, equipped with Bosch common rail system and high performance electronic control unit （ECU）, is designed correspondingly. Studies show that the integration of a common rail injection system and the main and pilot duel injectors configurations, assisted with glow plug ignition device and flexible ECU, represents a promising approach to improve the potential of the low compression ratios diesel rotary engine. Currently the engine can run at 6 kr · min^-1 steadily and the power is about 68 kW/（4 kr ·min^- 1）.

姿控发动机开机过程瞬态流动特性研究

Liquid bipropellant attitude control rocket engines are widely used in satellites,manned spaceships,deep space probes and other spacecraft.The performance of an attitude control engine is directly related to the lifetime,control precision and safety of a spacecraft.The study of flow characteristics of an engine transient process is important to improve its performance.In this paper,the transient flow test of a transparent test piece was carried out during the starting process of the attitude control engine.Then the transient process of the test piece was simulated and compared with the test results to verify the rationality of the simulation model.Transient flow simulation was carried out for the starting process of the real engine injector.The results show that the filling of the outer ring of the oxidant circuit is slower than that of the central collecting cavity,and the filling of the second layer of the outer ring is slower than that of the first layer.The filling process in the fuel path starts from the cooling hole near the inlet side and the fuel flows out in the circumferential direction.Installation direction has little influence on engine starting flow process in the ground state.The filling time of the engine in its vacuum state is longer than that in the ground state,the filling time of oxidizer is 31%longer than that in ground state,and the filling time of fuel is 57%longer than that in ground state.

Assessment of Lead Exposures during Abrasive Blasting and Vacuuming in Ventilated Field Containments: A Case Study

Painting contractors have struggled with implementation and assessment of lead exposure controls leading to persistently elevated blood lead levels in this high-risk group of workers. The objective of this study was to assess the intensity of lead exposures based on commonly used air velocities inside field containment structures during abrasive blasting and vacuuming. Exposures were assessed over 14 days from April to July 2021 at a tainter gate and bridge lead paint removal project. Personal air samples, skin wipes, air velocity readings, and blood lead samples were collected. The geometric mean (GM) lead exposure for abrasive blasters and vacuumers was ≥4 × the OSHA Lead Permissible Exposure Limit (PEL) of 50 μg/m3. There was high variability in the personal lead exposures (Geometric standard deviation (GSD) 4.0 - 5.0). The GM hand wipe exposures exceeded a Dermal PEL of 500 μg/wipe (abrasive blaster 564 μg/wipe and vacuumer 754 μg/wipe). Residual lead was measured on workers’ hands in 67% of the post hand washing samples. Air velocities measured inside of the field containments ranged from 107 feet per minute to 229 feet per minute. The effect of air velocity on the concentration of lead on workers’ hands after work (F = 0.58, p = 0.35) and airborne lead concentration was not significant (F = 0.36, p = 0.48). Six of the eight workers’ blood lead levels increased after exposure to lead. There was a non-statistically significant relationship between lead remaining on workers’ hands after handwashing and an increase in blood lead level. This is the first study that assessed both ventilation flow rates used in the industrial painting industry and measurements of airborne and dermal (hands) lead exposures. For the projects evaluated, the collected exposure data indicate that air velocities frequently used in the industrial painting industry to ventilate field containment structures did not tend to prevent an increase in worker blood lead and were ineffective for adequately controlling elevated concentrations of airborne lead and preventing contact with workers’ hands.