Design of Electric Linear Load Simulator based on LabVIEW+PXI

In order to realize the hardware-in-the-loop (HIL) experiments of a certain type of electric linear actuator in the laboratory, an electric linear load simulator (ELLS) based on LabVIEW+PXI platform was developed to simulate the external force of the actuator under actual working conditions. In structural design, the ball screw is used to convert the PMSM torque into linear force. In hardware design, the system is built using the upper-lower computer system architecture based on PXI bus. In software design, the program is written in LabVIEW, which mainly includes the data processing and display program in the upper computer and the data acquisition program, the loading motor control program and the actuator control program in the lower computer (PXI), in order to ensure the loading accuracy of ELLS, control methods such as force closed-loop PID controller, position feedforward compensation and input feedforward compensation are also introduced in the loading motor program. Finally, the ELLS was built and the signal tracking tests were carried out. The experimental results shows that the loading accuracy can reach 93.5% and 90.3% when ELLS tracks 1000N-2 Hz and 1000N-5 Hz respectively, which proved that the accuracy of ELLS satisfies the “Double Ten Index”

Design of Electric Linear Load Simulator based on LabVIEW+PXI

In order to realize the hardware-in-the-loop (HIL) experiments of a certain type of electric linear actuator in the laboratory, an electric linear load simulator (ELLS) based on LabVIEW+PXI platform was developed to simulate the external force of the actuator under actual working conditions. In structural design, the ball screw is used to convert the PMSM torque into linear force. In hardware design, the system is built using the upper-lower computer system architecture based on PXI bus. In software design, the program is written in LabVIEW, which mainly includes the data processing and display program in the upper computer and the data acquisition program, the loading motor control program and the actuator control program in the lower computer (PXI), in order to ensure the loading accuracy of ELLS, control methods such as force closed-loop PID controller, position feedforward compensation and input feedforward compensation are also introduced in the loading motor program. Finally, the ELLS was built and the signal tracking tests were carried out. The experimental results shows that the loading accuracy can reach 93.5% and 90.3% when ELLS tracks 1000N-2 Hz and 1000N-5 Hz respectively, which proved that the accuracy of ELLS satisfies the “Double Ten Index”

Research on Control Algorithm of Electric Linear Loading System

This paper mainly focused on the problems of low loading accuracy in electric linear loading system, Firstly, the mathematical model is done on loading motor, loading motor driver and ball screw in the system. Then, the current loop proportional control is introduced, which improves the response speed of the load motor; In order to improve the loading accuracy and restrain excess force, a parallel algorithm based on fuzzy PID and repetitive control is designed in the force loop. The fuzzy controller improves the dynamic performance and anti-interference ability of the system. The repetitive controller periodically adjusts the deviation, which reduces the steady-state error of the system. Combination of the two controller results in good dynamic and static characteristics. The simulation results show that the proposed control algorithm is feasible, which has a certain engineering reference value

Research on Control Algorithm of Electric Linear Loading System

This paper mainly focused on the problems of low loading accuracy in electric linear loading system, Firstly, the mathematical model is done on loading motor, loading motor driver and ball screw in the system. Then, the current loop proportional control is introduced, which improves the response speed of the load motor; In order to improve the loading accuracy and restrain excess force, a parallel algorithm based on fuzzy PID and repetitive control is designed in the force loop. The fuzzy controller improves the dynamic performance and anti-interference ability of the system. The repetitive controller periodically adjusts the deviation, which reduces the steady-state error of the system. Combination of the two controller results in good dynamic and static characteristics. The simulation results show that the proposed control algorithm is feasible, which has a certain engineering reference value

Experimental Study on In Situ Storage of Grease-Lubricated Ball Screws

Lubricating grease plays an important role in the rolling screw transmission of the actuation system and is particularly concerned with the performance stability of long-term storage in aerospace applications. In this article, a batch of ball screws that were lying flat in the warehouse for about eight years were selected to extract lubricating grease from the screw raceway after being stored in situ. The oxidation performance, friction performance and rheological properties of lubricating grease were tested and compared to those of fresh grease to analyze and summarize the performance changes in lubricating grease. The transmission efficiency, friction torque, and temperature rise of ball screws without removing the original grease and those filled with fresh grease after cleaning were tested and compared. The impact of grease degradation on the transmission performance of ball screws was analyzed to provide a reference for ball screw lubrication schemes and further accelerated storage experimental design

Exploring a chemical input free advanced oxidation process based on nanobubble technology to treat organic micropollutants

Advanced oxidation processes (AOPs) are increasingly applied in water and wastewater treatment, but their energy consumption and chemical use may hinder their further implementation in a changing world. This study investigated the feasibility and mechanisms involved in a chemical-free nanobubble-based AOP for treating organic micropollutants in both synthetic and real water matrices. The removal efficiency of the model micropollutant Rhodamine B (RhB) by oxygen nanobubble AOP (98%) was significantly higher than for air (73%) and nitrogen nanobubbles (69%). The treatment performance was not significantly affected by pH (3–10) and the presence of ions (Ca2+, Mg2+, HCO3 −, and Cl−). Although a higher initial concentration of RhB (10 mg/L) led to a slower treatment process when compared to lower initial concentrations (0.1 and 1 mg/L), the final removal performance reached a similar level (∼98%) between 100 and 500 min. The coexistence of organic matter (humic acid, HA) resulted in a much lower reduction (70%) in the RhB removal rate. Both qualitative and quantitative analysis of reactive oxygen species (ROSs) using fluorescent probe, electron spin resonance, and quenching experiments demonstrated that the contributions of ROSs in RhB degradation followed the order: hydroxyl radical (•OH) > superoxide radical (•O2 −) > singlet oxygen (1O2). The cascade degradation reactions for RhB were identified which involve N-de-ethylation, hydroxylation, chromophore cleavage, opening-ring and final mineralisation processes. Moreover, the treatment of real water samples spiked with RhB, including natural lake water and secondary effluent from a sewage works, still showed considerable removals of the dye (75.3%–90.8%), supporting its practical feasibility. Overall, the results benefit future research and application of chemical free nanobubble-based AOP for water and wastewater treatment

Exploring a chemical input free advanced oxidation process based on nanobubble technology to treat organic micropollutants

Advanced oxidation processes (AOPs) are increasingly applied in water and wastewater treatment, but their energy consumption and chemical use may hinder their further implementation in a changing world. This study investigated the feasibility and mechanisms involved in a chemical-free nanobubble-based AOP for treating organic micropollutants in both synthetic and real water matrices. The removal efficiency of the model micropollutant Rhodamine B (RhB) by oxygen nanobubble AOP (98%) was significantly higher than for air (73%) and nitrogen nanobubbles (69%). The treatment performance was not significantly affected by pH (3–10) and the presence of ions (Ca2+, Mg2+, HCO3−, and Cl−). Although a higher initial concentration of RhB (10 mg/L) led to a slower treatment process when compared to lower initial concentrations (0.1 and 1 mg/L), the final removal performance reached a similar level (∼98%) between 100 and 500 min. The coexistence of organic matter (humic acid, HA) resulted in a much lower reduction (70%) in the RhB removal rate. Both qualitative and quantitative analysis of reactive oxygen species (ROSs) using fluorescent probe, electron spin resonance, and quenching experiments demonstrated that the contributions of ROSs in RhB degradation followed the order: hydroxyl radical (•OH) > superoxide radical (•O2−) > singlet oxygen (1O2). The cascade degradation reactions for RhB were identified which involve N-de-ethylation, hydroxylation, chromophore cleavage, opening-ring and final mineralisation processes. Moreover, the treatment of real water samples spiked with RhB, including natural lake water and secondary effluent from a sewage works, still showed considerable removals of the dye (75.3%–90.8%), supporting its practical feasibility. Overall, the results benefit future research and application of chemical free nanobubble-based AOP for water and wastewater treatment