A novel ε-type solenoid actuator is proposed to improve the dynamic response of electro-pneumatic ejector valves by reducing moving mass weight. A finite element analysis (FEA) model has been developed to describe th...A novel ε-type solenoid actuator is proposed to improve the dynamic response of electro-pneumatic ejector valves by reducing moving mass weight. A finite element analysis (FEA) model has been developed to describe the static and dynamic operations of the valves. Compared with a conventional E-type actuator, the proposed ε-type actuator reduced the moving mass weight by almost 65% without significant loss of solenoid force, and reduced the response time (RT) typically by 20%. Prototype valves were designed and fabricated based on the proposed ε-type actuator model. An experimental setup was also established to investigate the dynamic characteristics of valves. The experimental results of the dynamics of valves agreed well with simulations, indicating the validity of the FEA model.展开更多
The performance of the designed digital electro-pneumatic cabin pressure control system for the cabin pressure schedule of transport aircraft is investigated.For the purpose of this study,an experimental setup consist...The performance of the designed digital electro-pneumatic cabin pressure control system for the cabin pressure schedule of transport aircraft is investigated.For the purpose of this study,an experimental setup consisting of a simulated hermetic cabin and altitude simulation chamber is configured for cabin pressure control system operation.A series of experimental tests are executed to evaluate the performance of the cabin pressure control system.The parameters of the PID controller are optimized.In the optimization process,the variation regularity of the rate of cabin pressure change under various conditions is considered.An approach to prioritize the control of the rate of change of cabin pressure based on the flight status model is proposed and verified experimentally.The experimental results indicate that the proposed approach can be adopted for the designed digital electro-pneumatic cabin pressure control system to obtain a better cabin pressure schedule and rate of cabin pressure change.展开更多
The high-pressure electro-pneumatic servo valve(HESV)is a core element of the high-pressure pneumatic servo system.The annular clearance and the rounded corner of the spool-sleeve can cause the leakage at null positio...The high-pressure electro-pneumatic servo valve(HESV)is a core element of the high-pressure pneumatic servo system.The annular clearance and the rounded corner of the spool-sleeve can cause the leakage at null position,thereby affecting high-precision control and stability of the servo system.This paper investigates the effects of the clearance structure on leakage behavior at null position of the HESV.A numerical approach was employed to evaluate the effects,and then a mathematical model was established to obtain the variation law of leakage flow rate at null position.The results indicate that the leakage flow rate at null position varies linearly with supply pressure and rounded corner radius,and is nonlinear as a quadratic concave function with annular clearance.The leakage flow rate of the annular clearance and the rounded corner varies with the valve opening in an invariable−nonlinear−linear trend.A test rig system of leakage behavior at null position of the HESV was built to confirm the validity of the numerical model,which agrees well with the conducted experimental study.展开更多
Inlet and outlet orifices in an actuation chamber are sources through which the supply and exhaust pressures pass during the actuation process in clutch systems. They are key ingredients in an actuation chamber and ar...Inlet and outlet orifices in an actuation chamber are sources through which the supply and exhaust pressures pass during the actuation process in clutch systems. They are key ingredients in an actuation chamber and are very phenomenal in heavy-duty vehicle operation. It is these pressures that initiate linear or rotary motions in drive systems. The pressure actions are processed in an enclosure termed an actuation chamber. Oftentimes, the forces or pressures produced in an actuation chamber are unknown and immeasurable owing to a lack of precise instruments to accomplish them. This challenge can only be approached via an improvised technique that requires experimentation. This is precisely what this presentation is all about. The knowledge of these parameters is important in the study of the actuation process in electro-pneumatic clutch systems of heavy-duty vehicles. The study was done with a Mercedes Benz Actros Truck Model MP 2, 2031 Actuator chamber. An empirical and analytical approach was adopted. Meter rule, Venire Callipers and Mass Spring Balance were deployed for the experiments. Piston coil or spring, clutch distance in the actuator, the cross-sectional diameter of the actuator, and displacement in the free lengths of the coils among others were measured. The results of the experiments were analysed and used to determine the values of the supply (inlet) and exhaust (outlet) pressures which results stood at 9.61 bars and 11.299 bars, respectively.展开更多
The large longitudinal impact of heavy-haul trains is the main factor limiting their development,and the asynchronous nature of train-braking systems is the main cause of this longitudinal impact.In this paper,a segme...The large longitudinal impact of heavy-haul trains is the main factor limiting their development,and the asynchronous nature of train-braking systems is the main cause of this longitudinal impact.In this paper,a segmented electro-pneumatic braking solution fully compatible with the existing freight-train braking system in China is proposed to improve the synchrony of train-braking systems.A simulation model for this braking system is developed based on air-flow theory,the 120 distribution valve and electronic control devices.The braking characteristics obtained from simulations are compared to those from the train-brake testing platform,and show high fidelity.On this basis,the effects of the new braking system on the braking capacity and longitudinal impact of a 20000 t heavy-haul train are analysed by further simulation.The results show that during service brakes,the segmented electro-pneumatic braking system can increase the braking capacity by 4.2–24.7%and reduce the coupler force by 21.6–68.0%.Therefore,it can be seen that the segmented electro-pneumatic braking system is a new type of electro-pneumatic brake that meets the needs of the Chinese railway network.It solves the problem of the longitudinal impact of heavy-haul trains satisfactorily,and its compatibility with the existing braking system(resulting in a reduced modification workload)makes it possible to maintain normal operations on heavy-haul lines while trains undergo modification.展开更多
Precise position tracking control of the single-rod pneumatic actuator is considered and a nonlinear cascade controller is developed.The proposed controller comprises an extended disturbance observer(EDOB)and a nonlin...Precise position tracking control of the single-rod pneumatic actuator is considered and a nonlinear cascade controller is developed.The proposed controller comprises an extended disturbance observer(EDOB)and a nonlinear robust control law synthesized by the backstepping method.The EDOB is designed to estimate not only the influence of disturbances but also the parameter uncertainties.With the use of parameter and disturbance estimates,the nonlinear cascade controller,which consists of an outer position tracking loop and an inner load pressure loop,is further designed to attenuate the effects of parameter and disturbance estimation errors.The stability of the closed-loop system is proven by means of Lyapunov theory.Extensive comparative experimental results obtained verify the effectiveness of the proposed nonlinear cascade controller and its performance robustness to parameter and external disturbance variations in practical implementation.展开更多
For the current robotic grasping scenario,the market for single gripper grippers to grasp items is limited,expensive,difficult to use,after-sales cumbersome,and other problems.This paper designs a multi-functional gri...For the current robotic grasping scenario,the market for single gripper grippers to grasp items is limited,expensive,difficult to use,after-sales cumbersome,and other problems.This paper designs a multi-functional gripper,integrating electro-pneumatic functions and designing multi-functional flanges,which can be used for all kinds of robots and multi-angle mounting,and designs multiple suction cups on the basis of the electric gripper to solve the problem that some items cannot be grasped,and designs various finger grippers at the end of the gripper to solve the problem of grasping items of different shapes.In this paper,the jaws are analyzed using the ANSYS Workbench for static simulations and also tested for gripping stability with a dozen terms.The versatile gripper has the advantages of compact design,reliable grip,easy maintenance,high-cost performance,and multi-scene use.展开更多
基金Project supported by the Doctoral Fund of Ministry of Education of China (No. 20070335133)the Educational Commission of Zhejiang Province (No. 20070057), China
文摘A novel ε-type solenoid actuator is proposed to improve the dynamic response of electro-pneumatic ejector valves by reducing moving mass weight. A finite element analysis (FEA) model has been developed to describe the static and dynamic operations of the valves. Compared with a conventional E-type actuator, the proposed ε-type actuator reduced the moving mass weight by almost 65% without significant loss of solenoid force, and reduced the response time (RT) typically by 20%. Prototype valves were designed and fabricated based on the proposed ε-type actuator model. An experimental setup was also established to investigate the dynamic characteristics of valves. The experimental results of the dynamics of valves agreed well with simulations, indicating the validity of the FEA model.
文摘The performance of the designed digital electro-pneumatic cabin pressure control system for the cabin pressure schedule of transport aircraft is investigated.For the purpose of this study,an experimental setup consisting of a simulated hermetic cabin and altitude simulation chamber is configured for cabin pressure control system operation.A series of experimental tests are executed to evaluate the performance of the cabin pressure control system.The parameters of the PID controller are optimized.In the optimization process,the variation regularity of the rate of cabin pressure change under various conditions is considered.An approach to prioritize the control of the rate of change of cabin pressure based on the flight status model is proposed and verified experimentally.The experimental results indicate that the proposed approach can be adopted for the designed digital electro-pneumatic cabin pressure control system to obtain a better cabin pressure schedule and rate of cabin pressure change.
基金Project(51705164)supported by the National Natural Science Foundation of China。
文摘The high-pressure electro-pneumatic servo valve(HESV)is a core element of the high-pressure pneumatic servo system.The annular clearance and the rounded corner of the spool-sleeve can cause the leakage at null position,thereby affecting high-precision control and stability of the servo system.This paper investigates the effects of the clearance structure on leakage behavior at null position of the HESV.A numerical approach was employed to evaluate the effects,and then a mathematical model was established to obtain the variation law of leakage flow rate at null position.The results indicate that the leakage flow rate at null position varies linearly with supply pressure and rounded corner radius,and is nonlinear as a quadratic concave function with annular clearance.The leakage flow rate of the annular clearance and the rounded corner varies with the valve opening in an invariable−nonlinear−linear trend.A test rig system of leakage behavior at null position of the HESV was built to confirm the validity of the numerical model,which agrees well with the conducted experimental study.
文摘Inlet and outlet orifices in an actuation chamber are sources through which the supply and exhaust pressures pass during the actuation process in clutch systems. They are key ingredients in an actuation chamber and are very phenomenal in heavy-duty vehicle operation. It is these pressures that initiate linear or rotary motions in drive systems. The pressure actions are processed in an enclosure termed an actuation chamber. Oftentimes, the forces or pressures produced in an actuation chamber are unknown and immeasurable owing to a lack of precise instruments to accomplish them. This challenge can only be approached via an improvised technique that requires experimentation. This is precisely what this presentation is all about. The knowledge of these parameters is important in the study of the actuation process in electro-pneumatic clutch systems of heavy-duty vehicles. The study was done with a Mercedes Benz Actros Truck Model MP 2, 2031 Actuator chamber. An empirical and analytical approach was adopted. Meter rule, Venire Callipers and Mass Spring Balance were deployed for the experiments. Piston coil or spring, clutch distance in the actuator, the cross-sectional diameter of the actuator, and displacement in the free lengths of the coils among others were measured. The results of the experiments were analysed and used to determine the values of the supply (inlet) and exhaust (outlet) pressures which results stood at 9.61 bars and 11.299 bars, respectively.
文摘The large longitudinal impact of heavy-haul trains is the main factor limiting their development,and the asynchronous nature of train-braking systems is the main cause of this longitudinal impact.In this paper,a segmented electro-pneumatic braking solution fully compatible with the existing freight-train braking system in China is proposed to improve the synchrony of train-braking systems.A simulation model for this braking system is developed based on air-flow theory,the 120 distribution valve and electronic control devices.The braking characteristics obtained from simulations are compared to those from the train-brake testing platform,and show high fidelity.On this basis,the effects of the new braking system on the braking capacity and longitudinal impact of a 20000 t heavy-haul train are analysed by further simulation.The results show that during service brakes,the segmented electro-pneumatic braking system can increase the braking capacity by 4.2–24.7%and reduce the coupler force by 21.6–68.0%.Therefore,it can be seen that the segmented electro-pneumatic braking system is a new type of electro-pneumatic brake that meets the needs of the Chinese railway network.It solves the problem of the longitudinal impact of heavy-haul trains satisfactorily,and its compatibility with the existing braking system(resulting in a reduced modification workload)makes it possible to maintain normal operations on heavy-haul lines while trains undergo modification.
基金Project(51505474)supported by the National Natural Science Foundation of ChinaProject(2015XKMS020)supported by the Fundamental Research Funds for the Central Universities,China+1 种基金Project(2016T90520)supported by the China Postdoctoral Science FoundationProject supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘Precise position tracking control of the single-rod pneumatic actuator is considered and a nonlinear cascade controller is developed.The proposed controller comprises an extended disturbance observer(EDOB)and a nonlinear robust control law synthesized by the backstepping method.The EDOB is designed to estimate not only the influence of disturbances but also the parameter uncertainties.With the use of parameter and disturbance estimates,the nonlinear cascade controller,which consists of an outer position tracking loop and an inner load pressure loop,is further designed to attenuate the effects of parameter and disturbance estimation errors.The stability of the closed-loop system is proven by means of Lyapunov theory.Extensive comparative experimental results obtained verify the effectiveness of the proposed nonlinear cascade controller and its performance robustness to parameter and external disturbance variations in practical implementation.
文摘For the current robotic grasping scenario,the market for single gripper grippers to grasp items is limited,expensive,difficult to use,after-sales cumbersome,and other problems.This paper designs a multi-functional gripper,integrating electro-pneumatic functions and designing multi-functional flanges,which can be used for all kinds of robots and multi-angle mounting,and designs multiple suction cups on the basis of the electric gripper to solve the problem that some items cannot be grasped,and designs various finger grippers at the end of the gripper to solve the problem of grasping items of different shapes.In this paper,the jaws are analyzed using the ANSYS Workbench for static simulations and also tested for gripping stability with a dozen terms.The versatile gripper has the advantages of compact design,reliable grip,easy maintenance,high-cost performance,and multi-scene use.
