An adaptive variable structure control method based on backstepping is proposed for the attitude maneuver problem of rigid spacecraft with reaction wheel dynamics in the presence of uncertain inertia matrix and extern...An adaptive variable structure control method based on backstepping is proposed for the attitude maneuver problem of rigid spacecraft with reaction wheel dynamics in the presence of uncertain inertia matrix and external disturbances. The proposed control approach is a combination of the backstepping and the adaptive variable structure control. The cascaded structure of the attitude maneuver control system with reaction wheel dynamics gives the advantage for applying the backstepping method to construct Lyapunov functions. The robust stability to external disturbances and parametric uncertainty is guaranteed by the adaptive variable structure control. To validate the proposed control algorithm, numerical simulations using the proposed approach are performed for the attitude maneuver mission of rigid spacecraft with a configuration consisting of four reaction wheels for actuator and three magnetorquers for momentum unloading. Simulation results verify the effectiveness of the proposed control algorithm.展开更多
The electrochemical nitrate reduction reaction(eNO_(3)^(-)RR)is considered an effective approach for converting nitrate-containing wastewater to ammonia.The adsorption and activation of NO_(3)^(-)is the critical step ...The electrochemical nitrate reduction reaction(eNO_(3)^(-)RR)is considered an effective approach for converting nitrate-containing wastewater to ammonia.The adsorption and activation of NO_(3)^(-)is the critical step for many materials and the high energy barrier inhibits the continuation of the reduction reaction.The Co nanoparticles encapsulated in the carbon layer we prepared spontaneously react with NO_(3)^(-)and the resulting Co^(2+)is then reduced by electroreduction to Co^(0),which circulates continuously.This resulted in overcoming the energy input required for NO_(3)^(-)adsorption and conversion,thereby increasing the catalytic activity.At the same time,the morphology of the catalyst reconstructed from a dodecahedron to an interwoven nanosheet structure and the increased surface area also gives it better properties.The obtained Co(OH)_(2)@Co-N-C has an excellent eNO_(3)^(-)RR of 2774.7μg·h^(-1)·cm^(-2)with a Faraday efficiency of 81.4%in neutral solution.At the same time,the material-modified electrode can run stably for more than 100 h.Our work provides a new idea for the design of Co-based catalysts for eNO_(3)^(-)RR.展开更多
基金Sponsored by the National Natural Science Foundation of China(Grant No.60674101)the Research Fund for the Doctoral Program of Higher Educa-tion of China(Grant No.20050213010)
文摘An adaptive variable structure control method based on backstepping is proposed for the attitude maneuver problem of rigid spacecraft with reaction wheel dynamics in the presence of uncertain inertia matrix and external disturbances. The proposed control approach is a combination of the backstepping and the adaptive variable structure control. The cascaded structure of the attitude maneuver control system with reaction wheel dynamics gives the advantage for applying the backstepping method to construct Lyapunov functions. The robust stability to external disturbances and parametric uncertainty is guaranteed by the adaptive variable structure control. To validate the proposed control algorithm, numerical simulations using the proposed approach are performed for the attitude maneuver mission of rigid spacecraft with a configuration consisting of four reaction wheels for actuator and three magnetorquers for momentum unloading. Simulation results verify the effectiveness of the proposed control algorithm.
基金supported by the National Natural Science Foundation of China(No.22175030)the Open Project of State Key Laboratory of Supramolecular Structure and Materials(No.sklssm 202406).
文摘The electrochemical nitrate reduction reaction(eNO_(3)^(-)RR)is considered an effective approach for converting nitrate-containing wastewater to ammonia.The adsorption and activation of NO_(3)^(-)is the critical step for many materials and the high energy barrier inhibits the continuation of the reduction reaction.The Co nanoparticles encapsulated in the carbon layer we prepared spontaneously react with NO_(3)^(-)and the resulting Co^(2+)is then reduced by electroreduction to Co^(0),which circulates continuously.This resulted in overcoming the energy input required for NO_(3)^(-)adsorption and conversion,thereby increasing the catalytic activity.At the same time,the morphology of the catalyst reconstructed from a dodecahedron to an interwoven nanosheet structure and the increased surface area also gives it better properties.The obtained Co(OH)_(2)@Co-N-C has an excellent eNO_(3)^(-)RR of 2774.7μg·h^(-1)·cm^(-2)with a Faraday efficiency of 81.4%in neutral solution.At the same time,the material-modified electrode can run stably for more than 100 h.Our work provides a new idea for the design of Co-based catalysts for eNO_(3)^(-)RR.
基金supported by the Science and Technology Project of Hebei Education Department (Grant No.JZX20230004)National Natural Science Fund of China (Grant No.12172118)+1 种基金Research Program of Local Science and Technology Development under the guidance of Central China (Grant No.216Z4402G)Open Project of the Chongqing Key Laboratory of Green (Grant No.GATRI2021F01005B).
