A 1-bit electronically controlled metasurface reflectarray is presented to achieve beam steering with multiple polarization manipulations. A metsurface unit cell loaded by two PIN diodes is designed. By switching the ...A 1-bit electronically controlled metasurface reflectarray is presented to achieve beam steering with multiple polarization manipulations. A metsurface unit cell loaded by two PIN diodes is designed. By switching the two PIN diodes between ON and OFF states, the isotropic and anisotropic reflections can be flexibly achieved. For either the isotropic reflection or the anisotropic reflection, the two operation states achieve the reflection coefficients with approximately equal magnitude and 180°out of phase, thus giving rise to the isotropic/anisotropic 1-bit metasurface unit cells. With the 1-bit unit cells, a 12-by-12 metasurface reflectarray is optimally designed and fabricated. Under either y-or x-polarized incident wave illumination, the reflectarray can achieve the co-polarized and cross-polarized beam scanning, respectively, with the peak gains of 20.08 d Bi and 17.26 d Bi within the scan range of about ±50°. With the right-handed circular polarization(RHCP) excitation, the left-handed circular polarization(LHCP) radiation with the peak gain of 16.98 d Bic can be achieved within the scan range of ±50°. Good agreement between the experimental results and the simulation results are observed for 2D beam steering and polarization manipulation capabilities.展开更多
In order to sample the speed signal of electronic diesel engine in real time and make the engine work reliable, the diesel engine control system's speed acquisition was studied and the problem of speed disturbance...In order to sample the speed signal of electronic diesel engine in real time and make the engine work reliable, the diesel engine control system's speed acquisition was studied and the problem of speed disturbance was solved. The control system was based on the 8?bit electronic control unit(ECU) system and the assembly language was used to design the software for controlling the engine fuel quantity and the turbocharger of the variable geometry turbine for the heavy duty diesel engine. By changing the timing method for speed acquisition, the problem of speed disturbance was solved and the reliability of the ECU was improved.展开更多
The current research of air suspension mainly focuses on the characteristics and design of the air spring. In fact, electronically controlled air suspension (ECAS) has excellent performance in flexible height adjust...The current research of air suspension mainly focuses on the characteristics and design of the air spring. In fact, electronically controlled air suspension (ECAS) has excellent performance in flexible height adjustment during different driving conditions. However, the nonlinearity of the ride height adjusting system and the uneven distribution of payload affect the control accuracy of ride height and the body attitude. Firstly, the three-point measurement system of three height sensors is used to establish the mathematical model of the ride height adjusting system. The decentralized control of ride height and the centralized control of body attitude are presented to design the ride height control system for ECAS. The exact feedback linearization method is adopted for the nonlinear mathematical model of the ride height system. Secondly, according to the hierarchical control theory, the variable structure control (VSC) technique is used to design a controller that is able to adjust the ride height for the quarter-vehicle anywhere, and each quarter-vehicle height control system is independent. Meanwhile, the three-point height signals obtained by three height sensors are tracked to calculate the body pitch and roll attitude over time, and then by calculating the deviation of pitch and roll and its rates, the height control correction is reassigned based on the fuzzy algorithm. Finally, to verify the effectiveness and performance of the proposed combined control strategy, a validating test of ride height control system with and without road disturbance is carried out. Testing results show that the height adjusting time of both lifting and lowering is over 5 s, and the pitch angle and the roll angle of body attitude are less than 0.15°. This research proposes a hierarchical control method that can guarantee the attitude stability, as well as satisfy the ride height tracking system.展开更多
Chinese traditional medicine wastewater, rich in macromolecule and easy to foam in aerobic biodegradation such as Glycosides, was treated by two identical bench-scale aerobic submerged membrane bioreactors (SMBRs) o...Chinese traditional medicine wastewater, rich in macromolecule and easy to foam in aerobic biodegradation such as Glycosides, was treated by two identical bench-scale aerobic submerged membrane bioreactors (SMBRs) operated in parallel under the same feed, equipped with the same electronic control backwashing device. One was used as the control SMBR (CSMBR) while the other was dosed with powdered activated carbon (PAC) (PAC-amended SMBR, PSMBR). The backwashing interval was 5 min. One suction period was about 90 min by adjusting preestablished backwashing vacuum and pump frequency. The average flux of CSMBR during a steady periodic state of 24 d (576 h) was 5.87 L/h with average hydraulic residence time (HRT) of 5.97 h and that of PSMBR during a steady periodic state of 30 d (720 h) was 5.85 L/h with average HRT of 5.99 h. The average total chemical oxygen demand (COD) removal efficiency of CSMBR was 89.29% with average organic loading rate (OLR) at 4.16 kg COD/(m^3.d) while that of PSMBR was 89.79% with average OLR at 5.50 kg COD/(m^3.d). COD concentration in the effluent of both SMBRs achieved the second level of the general wastewater effluent standard GB8978-1996 for the raw medicine material industry (300 mg/L). Hence, SMBR with electronic control backwashing was a viable process for medium-strength Chinese traditional medicine wastewater treatment. Moreover, the increasing rates of preestablished backwashing vacuum, pump frequency, and vacuum and flux loss caused by mixed liquor in PSMBR all lagged compared to those in CSMBR; thus the actual operating time of the PSMBR system without membrane cleaning was extended by up to 1.25 times in contrast with the CSMBR system, and the average total COD removal efficiency of PSMBR was enhanced with higher average OLR.展开更多
The control problems associated with vehicle height adjustment of electronically controlled air suspension (ECAS) still pose theoretical challenges for researchers, which manifest themselves in the publications on t...The control problems associated with vehicle height adjustment of electronically controlled air suspension (ECAS) still pose theoretical challenges for researchers, which manifest themselves in the publications on this subject over the last years. This paper deals with modeling and control of a vehicle height adjustment system for ECAS, which is an example of a hybrid dynamical system due to the coexistence and coupling of continuous variables and discrete events. A mixed logical dynamical (MLD) modeling approach is chosen for capturing enough details of the vehicle height adjustment process. The hybrid dynamic model is constructed on the basis of some assumptions and piecewise linear approximation for components nonlinearities. Then, the on-off statuses of solenoid valves and the piecewise approximation process are described by propositional logic, and the hybrid system is transformed into the set of linear mixed-integer equalities and inequalities, denoted as MLD model, automatically by HYSDEL. Using this model, a hybrid model predictive controller (HMPC) is tuned based on online mixed-integer quadratic optimization (MIQP). Two different scenarios are considered in the simulation, whose results verify the height adjustment effectiveness of the proposed approach. Explicit solutions of the controller are computed to control the vehicle height adjustment system in realtime using an offline multi-parametric programming technology (MPT), thus convert the controller into an equivalent explicit piecewise affine form. Finally, bench experiments for vehicle height lifting, holding and lowering procedures are conducted, which demonstrate that the HMPC can adjust the vehicle height by controlling the on-off statuses of solenoid valves directly. This research proposes a new modeling and control method for vehicle height adjustment of ECAS, which leads to a closed-loop system with favorable dynamical properties.展开更多
The rising number of electronic control units (ECUs) in vehicles and the decreasing time to market have led to the need for advanced methods of calibration. A multi-ECU calibration system was developed based on the ...The rising number of electronic control units (ECUs) in vehicles and the decreasing time to market have led to the need for advanced methods of calibration. A multi-ECU calibration system was developed based on the explicit calibration protocol (XCP) and J1939 communication protocol to satisfy the need of calibrating multiple ECUs simultaneously. The messages in the controller area network (CAN) are defined in the J1939 protocol. Each CAN node can get its own calibration messages and information from other ECUs, and block other messages by qualifying the CAN messages with priority, source or destination address. The data field of the calibration message is designed with the XCP, with CAN acting as the transport layer. The calibration sessions are setup with the event-triggered XCP driver in the master node and the responding XCP driver in the slave nodes. Mirroring calibration variables from ROM to RAM enables the user to calibrate ECUs online. The application example shows that the multi-ECU calibration system can calibrate multiple ECUs simultaneously, and the main program can also accomplish its calculation and send commands to the actuators in time. By the multi-ECU calibration system, the calibration effort and time can be reduced and the variables in ECU can get a better match with the variables of other ECUs.展开更多
In order to improve the cold start performance of heavy duty diesel engine, electronically controlling the preheating of intake air by flame was researched. According to simulation and thermodynamic analysis about th...In order to improve the cold start performance of heavy duty diesel engine, electronically controlling the preheating of intake air by flame was researched. According to simulation and thermodynamic analysis about the partial working processes of the diesel engine, the amount of heat energy, enough to make the fuel self ignite at the end of compression process at different temperatures of coolant and intake air, was calculated. Several HY20 preheating plugs were used to heat up the intake air. Meanwhile, an electronic control system based on 8 bit micro controller unit (MCS 8031) was designed to automatically control the process of heating intake air. According to the various temperatures of coolant and ambient air, one plug or two plugs can automatically be selected to heat intake air. The demo experiment validated that the total system could operate successfully and achieve the scheduled function.展开更多
A hardware-in-the-loop simulating platform is developed to avoid designing defects caused by the complicated logical structure and multiple-functional buildup of the dectronic control unit(ECU)in modem diesel engine...A hardware-in-the-loop simulating platform is developed to avoid designing defects caused by the complicated logical structure and multiple-functional buildup of the dectronic control unit(ECU)in modem diesel engines, and to diminish potential damages on components or human exposure to dangers in R&D en- deavor. This plat-form consists of a computer installed with software Matlab/Simulink/RTW and dSPACE/ ControlDesk; a diesel engine ECU, and a dSPACE autobox which runs a real-time diesel engine model. A typical model of diesel engine with turbocharger and intercooler is presented. Based on this model our research is carried out with a real ECU to test its software control strategies. Results show that by using the diesel engine model downloaded inside, the hardware-in-the-loop platform can simulate diesel engine's working conditions and generate all kinds of sensor signals which ECU needs on a real-time basis. So the ECU control strategies can be validated and relevant parameters roughly calibrated.展开更多
Today’s vehicles use electronic control units(ECU) to control engine/transmission, body and other amenities. All the vehicle performance depends on a lot of physical values and influence factors. This leads to a larg...Today’s vehicles use electronic control units(ECU) to control engine/transmission, body and other amenities. All the vehicle performance depends on a lot of physical values and influence factors. This leads to a large number of control and regulation parameters in the ECU software. The ultimate objective of calibration work is the optimum determination of these parameters. Qualitatively excellent results can only be achieved in a shorter time by using a highly efficient calibration system. This paper provided an overview of a new calibration tool based on KWP2000 and gave an example calibration with this tool.展开更多
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 ...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.展开更多
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 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展开更多
The performance of the electronic unit pump (EUP) diesel engine is studied, it will be used in the integrated powertrain and its multi parameters are controllable. Both the theoretical analysis and experiment research...The performance of the electronic unit pump (EUP) diesel engine is studied, it will be used in the integrated powertrain and its multi parameters are controllable. Both the theoretical analysis and experiment research are taken. A control unit for the fuel quantity and timing in crankshaft domain is designed on this basis and the engine experiment test has been done. For the constant speed camshaft driving EUP system, the fuel quantity will increase as the supply angle goes up and injection timing has no effect. The control precision can reach 1°CA. The full injection timing MAP and engine peak performance curves are made successfully.展开更多
This paper gives the brief view of the electronic control system of SPACE SOLAR TELESCOPE (SST), especially the On Board Data Handling unit (OBDH) on the SST which control the operation of the instrument, acquire data...This paper gives the brief view of the electronic control system of SPACE SOLAR TELESCOPE (SST), especially the On Board Data Handling unit (OBDH) on the SST which control the operation of the instrument, acquire data and make data analysis and storage. In OBDH, the Scientific Data Unit (SDU) is a special unit that requires high speed computer. In this paper gives a brief comparison of two possible choices and discuss selection of electronic parts in the space environment.展开更多
Aiming at the problem of poor uniformity of maize sowing caused by ground wheel slip,an electronic control seed-metering system(ECSMS)for maize single seed precision sowing was designed and a mathematical model for mo...Aiming at the problem of poor uniformity of maize sowing caused by ground wheel slip,an electronic control seed-metering system(ECSMS)for maize single seed precision sowing was designed and a mathematical model for motor control of the ECSMS was determined.The PID parameters were set by Z-N method and fuzzy control.The fuzzy PID control design and Simulink simulation were completed by MATLAB,which reduced response time of the system by 0.23 s and improved the control accuracy.Experiments on the JPS-12 test bench show that the qualification index(QI)of maize seed-metering device with the ECSMS increases by 4.47%,the multiples index(MI)decreases by 1.96%,the miss index(MIX)decreases by 2.81%,and the coefficient of variation(CV)of qualified seed spacing decreases by 5.06%,and the sowing uniformity has been greatly improved.Test results of the soil-tank test bench show that the system has good sowing uniformity and stability.And the QI is 96.74%,the MI is 2.15%,the MIX is 1.10%,and the CV of qualified seed spacing is 16.24%.Under different setting seed spacing and different sowing operation speed,the change range of seeding quality index was within 10%.The results of field sowing test show that the QI was 84.21%,the MI was 2.63%,the MIX was 7.89%,and the CV of qualified seed spacing was 22.15%,which meet the requirements of JB/T 10293-2013‘Specification for single seed planters(precision planters)’and the agronomic requirements for maize precision sowing.The system runs stably and reliably in practical operation and has good operation performance.展开更多
In order to improve the diesel engine emission performance and convert the diesel engine to dual fuel engine, a dual fuel (diesel and compressed natural gas (CNG)) electronic system was developed, in which electromagn...In order to improve the diesel engine emission performance and convert the diesel engine to dual fuel engine, a dual fuel (diesel and compressed natural gas (CNG)) electronic system was developed, in which electromagnetic valves were used to control multi point natural gas injection. The system was designed for type F6L912Q diesel engine and the function of the system was testified on test cell. The test results showed that the system had great advantages in power ability and emission performance. The average CNG substitution at rated load was over 80%. The dual fuel system was practical. To adopt dual fuel system was a good way to improve the engine's emission performance.展开更多
This paper presents the study and application of the electronic device anti-interference techniques underhigh voltage and/or heavy current electro-magnetic circumstance in power system.[
A novel method of matching stiffness and continuous variable damping of an ECAS(electronically controlled air suspension) based on LQG(linear quadratic Gaussian) control was proposed to simultaneously improve the road...A novel method of matching stiffness and continuous variable damping of an ECAS(electronically controlled air suspension) based on LQG(linear quadratic Gaussian) control was proposed to simultaneously improve the road-friendliness and ride comfort of a two-axle school bus.Taking account of the suspension nonlinearities and target-height-dependent variation in suspension characteristics,a stiffness model of the ECAS mounted on the drive axle of the bus was developed based on thermodynamics and the key parameters were obtained through field tests.By determining the proper range of the target height for the ECAS of the fully-loaded bus based on the design requirements of vehicle body bounce frequency,the control algorithm of the target suspension height(i.e.,stiffness) was derived according to driving speed and road roughness.Taking account of the nonlinearities of a continuous variable semi-active damper,the damping force was obtained through the subtraction of the air spring force from the optimum integrated suspension force,which was calculated based on LQG control.Finally,a GA(genetic algorithm)-based matching method between stepped variable damping and stiffness was employed as a benchmark to evaluate the effectiveness of the LQG-based matching method.Simulation results indicate that compared with the GA-based matching method,both dynamic tire force and vehicle body vertical acceleration responses are markedly reduced around the vehicle body bounce frequency employing the LQG-based matching method,with peak values of the dynamic tire force PSD(power spectral density) decreased by 73.6%,60.8% and 71.9% in the three cases,and corresponding reduction are 71.3%,59.4% and 68.2% for the vehicle body vertical acceleration.A strong robustness to variation of driving speed and road roughness is also observed for the LQG-based matching method.展开更多
As a core part of subsea production systems,subsea control modules(SCMs)are costly,difficult,and expensive to install and inconvenient to use in underwater maintenance.Therefore,performance and function tests must be ...As a core part of subsea production systems,subsea control modules(SCMs)are costly,difficult,and expensive to install and inconvenient to use in underwater maintenance.Therefore,performance and function tests must be carried out before launching SCMs.This study developed a testing device and an SCM test by investigating SCMs and their underwater.The testing device includes four parts:a hydraulic station,an SCM test stand,a signal generating device,and an electronic test unit.First,the basic indices of the testing device were determined from the performance and working parameters of the SCM.Second,the design scheme of the testing device for the SCM was tentatively proposed,and each testing device was designed.Finally,a practical measurement of the SCM,in combination with the hydraulic station,SCM test stand,signal generator,electronic unit,and highpressure water tank,was carried out according to the test requirements.The measurement mainly involved equipment inspection before testing and an experimental test for the SCM.The validity and feasibility of the testing device and method were simultaneously verified through an association test.展开更多
Combining with the development of automated manual transmission (AMT), the various throttle control demands are analyzed under different working conditions of AMT such as tracking acceleration pedal, start, shift an...Combining with the development of automated manual transmission (AMT), the various throttle control demands are analyzed under different working conditions of AMT such as tracking acceleration pedal, start, shift and so on. Based on simulation, the responding throttle control strategies are proposed, and a simple but effective throttle control method is presented. The testing results have proved that the strategies are effective for improving the pedal tracking precision and the qualities of start and shift.展开更多
The control problem of trajectory based path following for passenger vehicles is studied. Comprehensive nonlinear vehicle model is utilized for simulation vehicle response during various maneuvers in MATLAB/Simulink. ...The control problem of trajectory based path following for passenger vehicles is studied. Comprehensive nonlinear vehicle model is utilized for simulation vehicle response during various maneuvers in MATLAB/Simulink. In order to follow desired path, a driver model is developed to enhance closed loop driver/vehicle model. Then, linear quadratic regulator(LQR) controller is developed which regulates direct yaw moment and corrective steering angle on wheels. Particle swam optimization(PSO) method is utilized to optimize the LQR controller for various dynamic conditions. Simulation results indicate that, over various maneuvers, side slip angle and lateral acceleration can be reduced by 10% and 15%, respectively, which sustain the vehicle stable. Also, anti-lock brake system is designed for longitudinal dynamics of vehicle to achieve desired slip during braking and accelerating. Proposed comprehensive controller demonstrates that vehicle steerability can increase by about 15% during severe braking by preventing wheel from locking and reducing stopping distance.展开更多
基金Project supported by the National Key Research and Development Program of China (Grant No.2021YFA1401001)the National Natural Science Foundation of China (Grant No.62371355)。
文摘A 1-bit electronically controlled metasurface reflectarray is presented to achieve beam steering with multiple polarization manipulations. A metsurface unit cell loaded by two PIN diodes is designed. By switching the two PIN diodes between ON and OFF states, the isotropic and anisotropic reflections can be flexibly achieved. For either the isotropic reflection or the anisotropic reflection, the two operation states achieve the reflection coefficients with approximately equal magnitude and 180°out of phase, thus giving rise to the isotropic/anisotropic 1-bit metasurface unit cells. With the 1-bit unit cells, a 12-by-12 metasurface reflectarray is optimally designed and fabricated. Under either y-or x-polarized incident wave illumination, the reflectarray can achieve the co-polarized and cross-polarized beam scanning, respectively, with the peak gains of 20.08 d Bi and 17.26 d Bi within the scan range of about ±50°. With the right-handed circular polarization(RHCP) excitation, the left-handed circular polarization(LHCP) radiation with the peak gain of 16.98 d Bic can be achieved within the scan range of ±50°. Good agreement between the experimental results and the simulation results are observed for 2D beam steering and polarization manipulation capabilities.
文摘In order to sample the speed signal of electronic diesel engine in real time and make the engine work reliable, the diesel engine control system's speed acquisition was studied and the problem of speed disturbance was solved. The control system was based on the 8?bit electronic control unit(ECU) system and the assembly language was used to design the software for controlling the engine fuel quantity and the turbocharger of the variable geometry turbine for the heavy duty diesel engine. By changing the timing method for speed acquisition, the problem of speed disturbance was solved and the reliability of the ECU was improved.
基金Supported by National Natural Science Foundation of China(Grant No.51105177)Jiangsu Provincial Natural Science Foundation of China(Grant No.BK20131255)+2 种基金Research Fund for the Doctoral Program of Higher Education of China(Grant No.20113227120015)Qing Lan Project of Jiangsu Province of China,Scientific Research Foundation for Advanced Talents,Jiangsu University,China(Grant No.11JDG047)Hunan Provincial Natural Science Foundation of China(Grant No.12JJ6036)
文摘The current research of air suspension mainly focuses on the characteristics and design of the air spring. In fact, electronically controlled air suspension (ECAS) has excellent performance in flexible height adjustment during different driving conditions. However, the nonlinearity of the ride height adjusting system and the uneven distribution of payload affect the control accuracy of ride height and the body attitude. Firstly, the three-point measurement system of three height sensors is used to establish the mathematical model of the ride height adjusting system. The decentralized control of ride height and the centralized control of body attitude are presented to design the ride height control system for ECAS. The exact feedback linearization method is adopted for the nonlinear mathematical model of the ride height system. Secondly, according to the hierarchical control theory, the variable structure control (VSC) technique is used to design a controller that is able to adjust the ride height for the quarter-vehicle anywhere, and each quarter-vehicle height control system is independent. Meanwhile, the three-point height signals obtained by three height sensors are tracked to calculate the body pitch and roll attitude over time, and then by calculating the deviation of pitch and roll and its rates, the height control correction is reassigned based on the fuzzy algorithm. Finally, to verify the effectiveness and performance of the proposed combined control strategy, a validating test of ride height control system with and without road disturbance is carried out. Testing results show that the height adjusting time of both lifting and lowering is over 5 s, and the pitch angle and the roll angle of body attitude are less than 0.15°. This research proposes a hierarchical control method that can guarantee the attitude stability, as well as satisfy the ride height tracking system.
基金Project supported by the Hi-Tech Research and Development Program(863)of China(No. 2002AA601310).
文摘Chinese traditional medicine wastewater, rich in macromolecule and easy to foam in aerobic biodegradation such as Glycosides, was treated by two identical bench-scale aerobic submerged membrane bioreactors (SMBRs) operated in parallel under the same feed, equipped with the same electronic control backwashing device. One was used as the control SMBR (CSMBR) while the other was dosed with powdered activated carbon (PAC) (PAC-amended SMBR, PSMBR). The backwashing interval was 5 min. One suction period was about 90 min by adjusting preestablished backwashing vacuum and pump frequency. The average flux of CSMBR during a steady periodic state of 24 d (576 h) was 5.87 L/h with average hydraulic residence time (HRT) of 5.97 h and that of PSMBR during a steady periodic state of 30 d (720 h) was 5.85 L/h with average HRT of 5.99 h. The average total chemical oxygen demand (COD) removal efficiency of CSMBR was 89.29% with average organic loading rate (OLR) at 4.16 kg COD/(m^3.d) while that of PSMBR was 89.79% with average OLR at 5.50 kg COD/(m^3.d). COD concentration in the effluent of both SMBRs achieved the second level of the general wastewater effluent standard GB8978-1996 for the raw medicine material industry (300 mg/L). Hence, SMBR with electronic control backwashing was a viable process for medium-strength Chinese traditional medicine wastewater treatment. Moreover, the increasing rates of preestablished backwashing vacuum, pump frequency, and vacuum and flux loss caused by mixed liquor in PSMBR all lagged compared to those in CSMBR; thus the actual operating time of the PSMBR system without membrane cleaning was extended by up to 1.25 times in contrast with the CSMBR system, and the average total COD removal efficiency of PSMBR was enhanced with higher average OLR.
基金Supported by National Natural Science Foundation of China(Grant No.51375212)Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions of China+1 种基金Research Fund for the Doctoral Program of Higher Education of China(Grant No.20133227130001)China Postdoctoral Science Foundation(Grant No.2014M551518)
文摘The control problems associated with vehicle height adjustment of electronically controlled air suspension (ECAS) still pose theoretical challenges for researchers, which manifest themselves in the publications on this subject over the last years. This paper deals with modeling and control of a vehicle height adjustment system for ECAS, which is an example of a hybrid dynamical system due to the coexistence and coupling of continuous variables and discrete events. A mixed logical dynamical (MLD) modeling approach is chosen for capturing enough details of the vehicle height adjustment process. The hybrid dynamic model is constructed on the basis of some assumptions and piecewise linear approximation for components nonlinearities. Then, the on-off statuses of solenoid valves and the piecewise approximation process are described by propositional logic, and the hybrid system is transformed into the set of linear mixed-integer equalities and inequalities, denoted as MLD model, automatically by HYSDEL. Using this model, a hybrid model predictive controller (HMPC) is tuned based on online mixed-integer quadratic optimization (MIQP). Two different scenarios are considered in the simulation, whose results verify the height adjustment effectiveness of the proposed approach. Explicit solutions of the controller are computed to control the vehicle height adjustment system in realtime using an offline multi-parametric programming technology (MPT), thus convert the controller into an equivalent explicit piecewise affine form. Finally, bench experiments for vehicle height lifting, holding and lowering procedures are conducted, which demonstrate that the HMPC can adjust the vehicle height by controlling the on-off statuses of solenoid valves directly. This research proposes a new modeling and control method for vehicle height adjustment of ECAS, which leads to a closed-loop system with favorable dynamical properties.
文摘The rising number of electronic control units (ECUs) in vehicles and the decreasing time to market have led to the need for advanced methods of calibration. A multi-ECU calibration system was developed based on the explicit calibration protocol (XCP) and J1939 communication protocol to satisfy the need of calibrating multiple ECUs simultaneously. The messages in the controller area network (CAN) are defined in the J1939 protocol. Each CAN node can get its own calibration messages and information from other ECUs, and block other messages by qualifying the CAN messages with priority, source or destination address. The data field of the calibration message is designed with the XCP, with CAN acting as the transport layer. The calibration sessions are setup with the event-triggered XCP driver in the master node and the responding XCP driver in the slave nodes. Mirroring calibration variables from ROM to RAM enables the user to calibrate ECUs online. The application example shows that the multi-ECU calibration system can calibrate multiple ECUs simultaneously, and the main program can also accomplish its calculation and send commands to the actuators in time. By the multi-ECU calibration system, the calibration effort and time can be reduced and the variables in ECU can get a better match with the variables of other ECUs.
文摘In order to improve the cold start performance of heavy duty diesel engine, electronically controlling the preheating of intake air by flame was researched. According to simulation and thermodynamic analysis about the partial working processes of the diesel engine, the amount of heat energy, enough to make the fuel self ignite at the end of compression process at different temperatures of coolant and intake air, was calculated. Several HY20 preheating plugs were used to heat up the intake air. Meanwhile, an electronic control system based on 8 bit micro controller unit (MCS 8031) was designed to automatically control the process of heating intake air. According to the various temperatures of coolant and ambient air, one plug or two plugs can automatically be selected to heat intake air. The demo experiment validated that the total system could operate successfully and achieve the scheduled function.
基金Sponsored by the Ministerial Level Advanced Research(10660060220)
文摘A hardware-in-the-loop simulating platform is developed to avoid designing defects caused by the complicated logical structure and multiple-functional buildup of the dectronic control unit(ECU)in modem diesel engines, and to diminish potential damages on components or human exposure to dangers in R&D en- deavor. This plat-form consists of a computer installed with software Matlab/Simulink/RTW and dSPACE/ ControlDesk; a diesel engine ECU, and a dSPACE autobox which runs a real-time diesel engine model. A typical model of diesel engine with turbocharger and intercooler is presented. Based on this model our research is carried out with a real ECU to test its software control strategies. Results show that by using the diesel engine model downloaded inside, the hardware-in-the-loop platform can simulate diesel engine's working conditions and generate all kinds of sensor signals which ECU needs on a real-time basis. So the ECU control strategies can be validated and relevant parameters roughly calibrated.
文摘Today’s vehicles use electronic control units(ECU) to control engine/transmission, body and other amenities. All the vehicle performance depends on a lot of physical values and influence factors. This leads to a large number of control and regulation parameters in the ECU software. The ultimate objective of calibration work is the optimum determination of these parameters. Qualitatively excellent results can only be achieved in a shorter time by using a highly efficient calibration system. This paper provided an overview of a new calibration tool based on KWP2000 and gave an example calibration with this tool.
文摘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.
文摘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
文摘The performance of the electronic unit pump (EUP) diesel engine is studied, it will be used in the integrated powertrain and its multi parameters are controllable. Both the theoretical analysis and experiment research are taken. A control unit for the fuel quantity and timing in crankshaft domain is designed on this basis and the engine experiment test has been done. For the constant speed camshaft driving EUP system, the fuel quantity will increase as the supply angle goes up and injection timing has no effect. The control precision can reach 1°CA. The full injection timing MAP and engine peak performance curves are made successfully.
文摘This paper gives the brief view of the electronic control system of SPACE SOLAR TELESCOPE (SST), especially the On Board Data Handling unit (OBDH) on the SST which control the operation of the instrument, acquire data and make data analysis and storage. In OBDH, the Scientific Data Unit (SDU) is a special unit that requires high speed computer. In this paper gives a brief comparison of two possible choices and discuss selection of electronic parts in the space environment.
基金supported by Hebei Agriculture Research System(HBCT2024020205)The State Key Laboratory of North China Crop Improvement and Regulation(Grant No.NCCIR2024ZZ-12)+1 种基金The Sci-Tech Program of Hebei(Grant No.23567601H)The Central Government Guides Local Funds for Scientific and Technological Development(Grant No.236Z7202G).
文摘Aiming at the problem of poor uniformity of maize sowing caused by ground wheel slip,an electronic control seed-metering system(ECSMS)for maize single seed precision sowing was designed and a mathematical model for motor control of the ECSMS was determined.The PID parameters were set by Z-N method and fuzzy control.The fuzzy PID control design and Simulink simulation were completed by MATLAB,which reduced response time of the system by 0.23 s and improved the control accuracy.Experiments on the JPS-12 test bench show that the qualification index(QI)of maize seed-metering device with the ECSMS increases by 4.47%,the multiples index(MI)decreases by 1.96%,the miss index(MIX)decreases by 2.81%,and the coefficient of variation(CV)of qualified seed spacing decreases by 5.06%,and the sowing uniformity has been greatly improved.Test results of the soil-tank test bench show that the system has good sowing uniformity and stability.And the QI is 96.74%,the MI is 2.15%,the MIX is 1.10%,and the CV of qualified seed spacing is 16.24%.Under different setting seed spacing and different sowing operation speed,the change range of seeding quality index was within 10%.The results of field sowing test show that the QI was 84.21%,the MI was 2.63%,the MIX was 7.89%,and the CV of qualified seed spacing was 22.15%,which meet the requirements of JB/T 10293-2013‘Specification for single seed planters(precision planters)’and the agronomic requirements for maize precision sowing.The system runs stably and reliably in practical operation and has good operation performance.
文摘In order to improve the diesel engine emission performance and convert the diesel engine to dual fuel engine, a dual fuel (diesel and compressed natural gas (CNG)) electronic system was developed, in which electromagnetic valves were used to control multi point natural gas injection. The system was designed for type F6L912Q diesel engine and the function of the system was testified on test cell. The test results showed that the system had great advantages in power ability and emission performance. The average CNG substitution at rated load was over 80%. The dual fuel system was practical. To adopt dual fuel system was a good way to improve the engine's emission performance.
文摘This paper presents the study and application of the electronic device anti-interference techniques underhigh voltage and/or heavy current electro-magnetic circumstance in power system.[
基金Projects(51305117,51178158)supported by the National Natural Science Foundation of ChinaProject(20130111120031)supported by the Specialized Research Fund for the Doctoral Program of Higher Education+1 种基金Project(2013M530230)supported by the China Postdoctoral Science FoundationProjects(2012HGQC0015,2011HGBZ0945)supported by the Fundamental Research Funds for the Central Universities,China
文摘A novel method of matching stiffness and continuous variable damping of an ECAS(electronically controlled air suspension) based on LQG(linear quadratic Gaussian) control was proposed to simultaneously improve the road-friendliness and ride comfort of a two-axle school bus.Taking account of the suspension nonlinearities and target-height-dependent variation in suspension characteristics,a stiffness model of the ECAS mounted on the drive axle of the bus was developed based on thermodynamics and the key parameters were obtained through field tests.By determining the proper range of the target height for the ECAS of the fully-loaded bus based on the design requirements of vehicle body bounce frequency,the control algorithm of the target suspension height(i.e.,stiffness) was derived according to driving speed and road roughness.Taking account of the nonlinearities of a continuous variable semi-active damper,the damping force was obtained through the subtraction of the air spring force from the optimum integrated suspension force,which was calculated based on LQG control.Finally,a GA(genetic algorithm)-based matching method between stepped variable damping and stiffness was employed as a benchmark to evaluate the effectiveness of the LQG-based matching method.Simulation results indicate that compared with the GA-based matching method,both dynamic tire force and vehicle body vertical acceleration responses are markedly reduced around the vehicle body bounce frequency employing the LQG-based matching method,with peak values of the dynamic tire force PSD(power spectral density) decreased by 73.6%,60.8% and 71.9% in the three cases,and corresponding reduction are 71.3%,59.4% and 68.2% for the vehicle body vertical acceleration.A strong robustness to variation of driving speed and road roughness is also observed for the LQG-based matching method.
基金supported by the National Key R&D Program of China(2018YFC0310500)High-Tech Ship Research Projects sponsored by the Ministry of Industry and Information Technology(2018GXB01)Yantai City school land integration development project(2019XDRHXMPT29)research and development and test platform of underwater production system。
文摘As a core part of subsea production systems,subsea control modules(SCMs)are costly,difficult,and expensive to install and inconvenient to use in underwater maintenance.Therefore,performance and function tests must be carried out before launching SCMs.This study developed a testing device and an SCM test by investigating SCMs and their underwater.The testing device includes four parts:a hydraulic station,an SCM test stand,a signal generating device,and an electronic test unit.First,the basic indices of the testing device were determined from the performance and working parameters of the SCM.Second,the design scheme of the testing device for the SCM was tentatively proposed,and each testing device was designed.Finally,a practical measurement of the SCM,in combination with the hydraulic station,SCM test stand,signal generator,electronic unit,and highpressure water tank,was carried out according to the test requirements.The measurement mainly involved equipment inspection before testing and an experimental test for the SCM.The validity and feasibility of the testing device and method were simultaneously verified through an association test.
基金This project is supported by Provincial Open Foundation of Key Lab forAutomobile of Jiangsu, China (No.KJS02076) and 985 Project of AutomotiveEngineering Innovation Platform of Jilin University, China.
文摘Combining with the development of automated manual transmission (AMT), the various throttle control demands are analyzed under different working conditions of AMT such as tracking acceleration pedal, start, shift and so on. Based on simulation, the responding throttle control strategies are proposed, and a simple but effective throttle control method is presented. The testing results have proved that the strategies are effective for improving the pedal tracking precision and the qualities of start and shift.
文摘The control problem of trajectory based path following for passenger vehicles is studied. Comprehensive nonlinear vehicle model is utilized for simulation vehicle response during various maneuvers in MATLAB/Simulink. In order to follow desired path, a driver model is developed to enhance closed loop driver/vehicle model. Then, linear quadratic regulator(LQR) controller is developed which regulates direct yaw moment and corrective steering angle on wheels. Particle swam optimization(PSO) method is utilized to optimize the LQR controller for various dynamic conditions. Simulation results indicate that, over various maneuvers, side slip angle and lateral acceleration can be reduced by 10% and 15%, respectively, which sustain the vehicle stable. Also, anti-lock brake system is designed for longitudinal dynamics of vehicle to achieve desired slip during braking and accelerating. Proposed comprehensive controller demonstrates that vehicle steerability can increase by about 15% during severe braking by preventing wheel from locking and reducing stopping distance.