The steel lining of huge facilities is a significant structure,which experiences extreme environments and needs to be inspected periodically after manufacture.However,due to the complexity(crisscross welds,curved surf...The steel lining of huge facilities is a significant structure,which experiences extreme environments and needs to be inspected periodically after manufacture.However,due to the complexity(crisscross welds,curved surface,etc.)of their inside environments,high demands for stable adhesion and curvature adaptability are put forward.This paper presents a novel wheeled magnetic adhesion robot with passive suspension applied in nuclear power containment called NuBot,and mainly focuses on the following aspects:(1)proposing the wheeled locomotion suspension to adapt the robot to the uneven surface;(2)implementing the parameter optimization of NuBot.A comprehensive optimization model is established,and global optimal dimensions are properly chosen from performance atlases;(3)determining the normalization factor and actual dimensional parameters by constraints of the steel lining environment;(4)structure design of the overall robot and the magnetic wheels are completed.Experiments show that the robot can achieve precise locomotion on both strong and weak magnetic walls with various inclination angles,and can stably cross the 5 mm weld seam.Besides,its maximum payload capacity reaches 3.6 kg.Results show that the NuBot designed by the proposed systematic method has good comprehensive capabilities of surface-adaptability,adhesion stability,and payload.Besides,the robot can be applied in more ferromagnetic environments and the design method offers guidance for similar wheeled robots with passive suspension.展开更多
In this paper,we have formulated mathematical models to optimize the bouncing transmissibility of the sprung mass of the half car system with passengers’seat suspensions considering different road conditions.The corr...In this paper,we have formulated mathematical models to optimize the bouncing transmissibility of the sprung mass of the half car system with passengers’seat suspensions considering different road conditions.The corresponding problem has been solved with the help of advanced real coded Genetic Algorithm(GA).The nonlinearity of suspension spring and damper,which are the most important characteristics of the suspension,has been taken into account in order to validate the model to real applications.The nonlinear cubic polynomial has been used to describe the spring characteristic and a quadratic polynomial has been used to describe the damper characteristic.The coefficients of each polynomial represent the design parameters of the suspension system and are to be determined.To find these parameters we have formulated a nonlinear optimization problem in which the bouncing transmissibility of the sprung mass at the center of mass has been minimized with respect to technological constraints and the constraints which satisfy the performance as per ISO 2631 standards.The advanced real coded GA has been used to solve this problem in time domain and the results obtained have been compared to those obtained using the existing design parameters.The objective function and the constraints have been evaluated by simulating the vehicle model over two roads with multiple bumps at uniform velocity.展开更多
The most usual way of using chemical method to protect crop against weed, insects, and fungi is spraying the mixture of chemicals and water onto crop through the nozzles. Sprayers usually moved on the field by tractor...The most usual way of using chemical method to protect crop against weed, insects, and fungi is spraying the mixture of chemicals and water onto crop through the nozzles. Sprayers usually moved on the field by tractor, and tractor induced unwanted vibration to sprayer because of uneven soil or terrain. This oscillation leads to over-doses and under-doses of chemical sprayed on the field. For this reason, many commercial and some theoretical suspension were made to reduce undesirable vibration. Therefore, in this study a finite element based model was established to represent the dynamic behavior of spray boom structure with 8m width. The first tenth natural frequencies were obtained between 9.25 Hz to 1,182.5 Hz. Also, a passive vertical suspension was designed to remove unwanted vibration with 0.5 vibration transmissibility. Finally, the suspension system was simulated to be as certain of its efficiency. The results of simulation have good agreement to the proposed aim.展开更多
基金Supported by Shanghai Nuclear Star Nuclear Power Technology Co.,Ltd,National Natural Science Foundation of China(Grant No.51735009)State Key Lab of Mechanical System and Vibration Project(Grant No.MSVZD202008).
文摘The steel lining of huge facilities is a significant structure,which experiences extreme environments and needs to be inspected periodically after manufacture.However,due to the complexity(crisscross welds,curved surface,etc.)of their inside environments,high demands for stable adhesion and curvature adaptability are put forward.This paper presents a novel wheeled magnetic adhesion robot with passive suspension applied in nuclear power containment called NuBot,and mainly focuses on the following aspects:(1)proposing the wheeled locomotion suspension to adapt the robot to the uneven surface;(2)implementing the parameter optimization of NuBot.A comprehensive optimization model is established,and global optimal dimensions are properly chosen from performance atlases;(3)determining the normalization factor and actual dimensional parameters by constraints of the steel lining environment;(4)structure design of the overall robot and the magnetic wheels are completed.Experiments show that the robot can achieve precise locomotion on both strong and weak magnetic walls with various inclination angles,and can stably cross the 5 mm weld seam.Besides,its maximum payload capacity reaches 3.6 kg.Results show that the NuBot designed by the proposed systematic method has good comprehensive capabilities of surface-adaptability,adhesion stability,and payload.Besides,the robot can be applied in more ferromagnetic environments and the design method offers guidance for similar wheeled robots with passive suspension.
文摘In this paper,we have formulated mathematical models to optimize the bouncing transmissibility of the sprung mass of the half car system with passengers’seat suspensions considering different road conditions.The corresponding problem has been solved with the help of advanced real coded Genetic Algorithm(GA).The nonlinearity of suspension spring and damper,which are the most important characteristics of the suspension,has been taken into account in order to validate the model to real applications.The nonlinear cubic polynomial has been used to describe the spring characteristic and a quadratic polynomial has been used to describe the damper characteristic.The coefficients of each polynomial represent the design parameters of the suspension system and are to be determined.To find these parameters we have formulated a nonlinear optimization problem in which the bouncing transmissibility of the sprung mass at the center of mass has been minimized with respect to technological constraints and the constraints which satisfy the performance as per ISO 2631 standards.The advanced real coded GA has been used to solve this problem in time domain and the results obtained have been compared to those obtained using the existing design parameters.The objective function and the constraints have been evaluated by simulating the vehicle model over two roads with multiple bumps at uniform velocity.
文摘The most usual way of using chemical method to protect crop against weed, insects, and fungi is spraying the mixture of chemicals and water onto crop through the nozzles. Sprayers usually moved on the field by tractor, and tractor induced unwanted vibration to sprayer because of uneven soil or terrain. This oscillation leads to over-doses and under-doses of chemical sprayed on the field. For this reason, many commercial and some theoretical suspension were made to reduce undesirable vibration. Therefore, in this study a finite element based model was established to represent the dynamic behavior of spray boom structure with 8m width. The first tenth natural frequencies were obtained between 9.25 Hz to 1,182.5 Hz. Also, a passive vertical suspension was designed to remove unwanted vibration with 0.5 vibration transmissibility. Finally, the suspension system was simulated to be as certain of its efficiency. The results of simulation have good agreement to the proposed aim.
