A gearbox in-the-loop control platform using dSPACE real-time system is designed for the study on the control technology of pneumatic selecting and shifting actuators based on rapid control prototyping.The operational...A gearbox in-the-loop control platform using dSPACE real-time system is designed for the study on the control technology of pneumatic selecting and shifting actuators based on rapid control prototyping.The operational principle of such actuators was analyzed using dSPACE hardware and software,resulting in a better knowledge of the logical relationship among solenoid valves,gear positions of cylinders and system input/output.Based on these,a control model was developed under the Matlab/Simulink environment and rapidly improved to meet requirements through experiments.Relevant tests have shown that analysis efficiency on selecting and shifting actuators could be raised and development of control strategy facilitated.展开更多
In some cases of emergency backfill engineering projects, traditional backfill materials cannot meet the requirements of fast construction due to their long curing time. This study presents a new kind of rapid hardeni...In some cases of emergency backfill engineering projects, traditional backfill materials cannot meet the requirements of fast construction due to their long curing time. This study presents a new kind of rapid hardening controlled low strength material, which utilizes both rapid hardening sulphoaluminate cement and recycled fine aggregate from urban red brick construction waste. Totally, sixteen mixtures were prepared for the experiment with different cement-to-sand ratios and water-to-solid ratios. The flowability and bleeding rate of fresh mixture were measured to evaluate its workability, and the compressive strength of hardened mixture was tested to evaluate its rapid hardening and mechanical properties. Test results indicate that rapid hardening controlled low strength material containing recycled fine aggregate from urban red brick construction waste can achieve the desirable flowability, but the bleeding rate increases with the increase of flowability. In addition, 2-hour compressive strength can reach 0.08 - 0.12 MPa, and 4-hour compressive strength is 0.32 - 1.54 MPa, which can meet the requirements of emergency backfill construction. At last, based on the derived compressive strength, a fitting model for predicting compressive strength evolution of this new rapid hardening backfill material is developed, which fits accurately with these experimental data.展开更多
In this paper the control mechanism of solenoid valve is analyzed,which shows the solenoid valve control is actually the control of coil current.The response characteristic of coil current is related to coil inductanc...In this paper the control mechanism of solenoid valve is analyzed,which shows the solenoid valve control is actually the control of coil current.The response characteristic of coil current is related to coil inductance and resistance.The coil resistance is influenced greatly by the ambient temperature and the self-heating of coil,which affects the control precision of coil current.First,considering the heat dissipation mode of coil,the coil temperature model is established from the perspective of heat conduction,and a temperature compensation algorithm for hydraulic system pressure control is put forward.Then the hardware-in-the-loop testbed is set up by using the dSPACE platform,carrying out wheel cylinder pressurization tests with inlet valve fully opened at-40℃ and 20℃,and testing the actual pressure of wheel cylinder with the target pressures at-40℃ and 6 000 kPa/s(pressurization rate).The results show that the pressure control temperature compensation algorithm proposed in this paper accurately corrects the influence of resistance temperature drift on the response accuracy of wheel cylinder pressure.After the correction,the pressure difference is less than 500 kPa,which can meet the control accuracy requirements of solenoid valve,enriching the linear control characteristic of solenoid valve.展开更多
Four-wheel independently driven electric vehicles(FWID-EV)endow a flexible and scalable control framework to improve vehicle performance.This paper integrates the torque vectoring and active suspension system(ASS)to e...Four-wheel independently driven electric vehicles(FWID-EV)endow a flexible and scalable control framework to improve vehicle performance.This paper integrates the torque vectoring and active suspension system(ASS)to enhance the vehicle’s longitudinal and vertical motion control performance.While the nonlinear characteristic of the tire model leads to a relatively heavier computational burden.To facilitate the controller design and ease the load,a half-vehicle dynamics system is built and simplified to the linear-time-varying(LTV)model.Then a model predictive controller is developed by formulating the objective function by comprehensively considering the safety,energy-saving and comfort requirements.The in-wheel motor efficiency and the power loss of tire slip are treated as optimization indices in this work to reduce energy consumption.Finally,the effectiveness of the proposed controller is verified through the rapid-control-prototype(RCP)test.The results demonstrate the enhancement of the energy-saving as well as comfort on the basis of vehicle stability.展开更多
Digital valve control servo system is studied in this paper. In order to solve the system problems of poor control precision and slow response time,a CMAC-PID( cerebellar model articulation controller-PID) compound co...Digital valve control servo system is studied in this paper. In order to solve the system problems of poor control precision and slow response time,a CMAC-PID( cerebellar model articulation controller-PID) compound control method is proposed. This compound controller consists of two components: one is a traditional PID for the feedback control to guarantee stability of the system; the other is the CMAC control algorithm to form a feed-forward control for achieving high control precision and short response time of the controlled plant. Then the CMAC-PID compound control method is used in the digital valve control servo system to improve its control performance. Through simulation and experiment,the proposed CMAC-PID compound control method is superior to the traditional PID control for enhancing stability and robustness,and thus this compound control can be used as a new control strategy for the digital valve control servo system.展开更多
Although intelligent hydrogels have shown bright potential application in biomedical fields,they were prepared by conventional methods and still face many serious challenges,such as uncontrollable stimulus-response an...Although intelligent hydrogels have shown bright potential application in biomedical fields,they were prepared by conventional methods and still face many serious challenges,such as uncontrollable stimulus-response and low response sensitivity.Recently,RAFT polymerization provides a versatile strategy for the fabrication of intelligent hydrogels with improved stimulus-response properties,owing to the ability to efficiently construct hydrogel precursors with well-defined structure,such as block copolymer,graft copolymer,star copolymer.In this review,we summarized the recent progress on intelligent hydrogels based on RAFT polymerization with emphasis on their fabrication strategies and applications for controlled drug delivery.展开更多
Under India’s National AIDS Control Program (NACP), WHO recommended strategy of using three rapid tests is adopted for diagnosis of HIV in an asymptomatic individual. Since the NACP has a stringent kit evaluation pro...Under India’s National AIDS Control Program (NACP), WHO recommended strategy of using three rapid tests is adopted for diagnosis of HIV in an asymptomatic individual. Since the NACP has a stringent kit evaluation procedure and due to the availability of newer third generation Rapid Diagnostic Tests (RDTs) it may be possible to adapt two test strategy for HIV diagnosis instead of the recommended three test strategy. The authors reviewed programmatic data on HIV testing to explore whether use of two rapid tests for HIV diagnosis as against three tests could be a feasible approach without compromising the quality and readability of testing. Data on the HIV diagnosis performed on serum specimens collected for the period of one year (2011-12) from 82 Integrated Testing and Counselling Centers (ICTCs) or Prevention of Parent to Child Transmission Centers (PPTCTs) associated with State reference Laboratories (SRLs) was analysed. Out of 654258 results that were analysed 25168 (3.84%) specimens were positives. It was observed that both two and three test algorithms provided similar results for majority (>99%) of the HIV positive specimens. Discordance was observed in labelling of specimen with inconclusive status (N = 21), however the true status of these samples could not be obtained. The analysis indicated that the use of two test algorithm will have programmatic benefits in terms of reduced financial burden to the programme and ease of procurement, shipment and storage before and after distribution without comprising the quality of the testing. The prospective study would confirm this observation.展开更多
文摘A gearbox in-the-loop control platform using dSPACE real-time system is designed for the study on the control technology of pneumatic selecting and shifting actuators based on rapid control prototyping.The operational principle of such actuators was analyzed using dSPACE hardware and software,resulting in a better knowledge of the logical relationship among solenoid valves,gear positions of cylinders and system input/output.Based on these,a control model was developed under the Matlab/Simulink environment and rapidly improved to meet requirements through experiments.Relevant tests have shown that analysis efficiency on selecting and shifting actuators could be raised and development of control strategy facilitated.
文摘In some cases of emergency backfill engineering projects, traditional backfill materials cannot meet the requirements of fast construction due to their long curing time. This study presents a new kind of rapid hardening controlled low strength material, which utilizes both rapid hardening sulphoaluminate cement and recycled fine aggregate from urban red brick construction waste. Totally, sixteen mixtures were prepared for the experiment with different cement-to-sand ratios and water-to-solid ratios. The flowability and bleeding rate of fresh mixture were measured to evaluate its workability, and the compressive strength of hardened mixture was tested to evaluate its rapid hardening and mechanical properties. Test results indicate that rapid hardening controlled low strength material containing recycled fine aggregate from urban red brick construction waste can achieve the desirable flowability, but the bleeding rate increases with the increase of flowability. In addition, 2-hour compressive strength can reach 0.08 - 0.12 MPa, and 4-hour compressive strength is 0.32 - 1.54 MPa, which can meet the requirements of emergency backfill construction. At last, based on the derived compressive strength, a fitting model for predicting compressive strength evolution of this new rapid hardening backfill material is developed, which fits accurately with these experimental data.
基金Supported by the National High Technology Research and Development Program of China(863 Program)(2012AA110903)Jilin Key Scientific and Technological Project(20170204085GX)Jilin Industrial Technology Innovation Strategic Alliance Program(20150309013GX)
文摘In this paper the control mechanism of solenoid valve is analyzed,which shows the solenoid valve control is actually the control of coil current.The response characteristic of coil current is related to coil inductance and resistance.The coil resistance is influenced greatly by the ambient temperature and the self-heating of coil,which affects the control precision of coil current.First,considering the heat dissipation mode of coil,the coil temperature model is established from the perspective of heat conduction,and a temperature compensation algorithm for hydraulic system pressure control is put forward.Then the hardware-in-the-loop testbed is set up by using the dSPACE platform,carrying out wheel cylinder pressurization tests with inlet valve fully opened at-40℃ and 20℃,and testing the actual pressure of wheel cylinder with the target pressures at-40℃ and 6 000 kPa/s(pressurization rate).The results show that the pressure control temperature compensation algorithm proposed in this paper accurately corrects the influence of resistance temperature drift on the response accuracy of wheel cylinder pressure.After the correction,the pressure difference is less than 500 kPa,which can meet the control accuracy requirements of solenoid valve,enriching the linear control characteristic of solenoid valve.
基金Supported by National Natural Science Foundation of China(Grant Nos.51975118,52025121)Foundation of State Key Laboratory of Automotive Simulation and Control of China(Grant No.20210104)+1 种基金Foundation of State Key Laboratory of Automobile Safety and Energy Saving of China(Grant No.KFZ2201)Special Fund of Jiangsu Province for the Transformation of Scientific and Technological Achievements of China(Grant No.BA2021023).
文摘Four-wheel independently driven electric vehicles(FWID-EV)endow a flexible and scalable control framework to improve vehicle performance.This paper integrates the torque vectoring and active suspension system(ASS)to enhance the vehicle’s longitudinal and vertical motion control performance.While the nonlinear characteristic of the tire model leads to a relatively heavier computational burden.To facilitate the controller design and ease the load,a half-vehicle dynamics system is built and simplified to the linear-time-varying(LTV)model.Then a model predictive controller is developed by formulating the objective function by comprehensively considering the safety,energy-saving and comfort requirements.The in-wheel motor efficiency and the power loss of tire slip are treated as optimization indices in this work to reduce energy consumption.Finally,the effectiveness of the proposed controller is verified through the rapid-control-prototype(RCP)test.The results demonstrate the enhancement of the energy-saving as well as comfort on the basis of vehicle stability.
基金Supported by the National Natural Science Foundation of China(No.51505412)the Independent Study Program for Young Teachers in Yanshan University(No.14LGB004)
文摘Digital valve control servo system is studied in this paper. In order to solve the system problems of poor control precision and slow response time,a CMAC-PID( cerebellar model articulation controller-PID) compound control method is proposed. This compound controller consists of two components: one is a traditional PID for the feedback control to guarantee stability of the system; the other is the CMAC control algorithm to form a feed-forward control for achieving high control precision and short response time of the controlled plant. Then the CMAC-PID compound control method is used in the digital valve control servo system to improve its control performance. Through simulation and experiment,the proposed CMAC-PID compound control method is superior to the traditional PID control for enhancing stability and robustness,and thus this compound control can be used as a new control strategy for the digital valve control servo system.
基金基金项目：国家重点基础研究发展计划（973计划）资助项目（2011CB933202）中围科学院战略性先导科技专项课题资助项目（XDA06020101）+3 种基金国家杰出青年自然基金资助项目（61125105）国家高技术研究发展计划（863计划）资助项目（2009AA03Z411）中国科学院科研装备研制资助项目（Y2010015）国家自然科学基金资助项目（61027001,61002037）.Acknowledgements This work was supported by the Major National Scientific Research Plan （No.2011CB933202）, ＂Strategic Priority Research Program＂ of the Chinese Academy of Sciences （No.XDA06020101）, the National Science Fund for Distinguished Young Scholar （No. 61125105）, the Hi-Tech R＆D Program of China （No. 2009AA03Z411）, the CAS Program （No.Y2010015） and the National Natural Science Foundation of China （No. 61027001, No. 61002037）.
基金supported by National Science and Technology Major Project of the Ministry of Science and Technology of China (No. 2018ZX10301402)International Cooperation and Exchange of the National Natural Science Foundation of China (No. 51820105004)+2 种基金the Science and Technology Program of Guangzhou (No. 201707010094)Guangdong Innovative and Entrepreneurial Research Team Program (Nos. 2013S086 and 2016ZT06S029)the Science and Technology Planning Project of Shenzhen (No. JCYJ20170307141438157)
文摘Although intelligent hydrogels have shown bright potential application in biomedical fields,they were prepared by conventional methods and still face many serious challenges,such as uncontrollable stimulus-response and low response sensitivity.Recently,RAFT polymerization provides a versatile strategy for the fabrication of intelligent hydrogels with improved stimulus-response properties,owing to the ability to efficiently construct hydrogel precursors with well-defined structure,such as block copolymer,graft copolymer,star copolymer.In this review,we summarized the recent progress on intelligent hydrogels based on RAFT polymerization with emphasis on their fabrication strategies and applications for controlled drug delivery.
文摘Under India’s National AIDS Control Program (NACP), WHO recommended strategy of using three rapid tests is adopted for diagnosis of HIV in an asymptomatic individual. Since the NACP has a stringent kit evaluation procedure and due to the availability of newer third generation Rapid Diagnostic Tests (RDTs) it may be possible to adapt two test strategy for HIV diagnosis instead of the recommended three test strategy. The authors reviewed programmatic data on HIV testing to explore whether use of two rapid tests for HIV diagnosis as against three tests could be a feasible approach without compromising the quality and readability of testing. Data on the HIV diagnosis performed on serum specimens collected for the period of one year (2011-12) from 82 Integrated Testing and Counselling Centers (ICTCs) or Prevention of Parent to Child Transmission Centers (PPTCTs) associated with State reference Laboratories (SRLs) was analysed. Out of 654258 results that were analysed 25168 (3.84%) specimens were positives. It was observed that both two and three test algorithms provided similar results for majority (>99%) of the HIV positive specimens. Discordance was observed in labelling of specimen with inconclusive status (N = 21), however the true status of these samples could not be obtained. The analysis indicated that the use of two test algorithm will have programmatic benefits in terms of reduced financial burden to the programme and ease of procurement, shipment and storage before and after distribution without comprising the quality of the testing. The prospective study would confirm this observation.
