A zero-speed fin stabilizer system was developed for rolling control of a marine robot.As a robot steering device near the sea surface with low speed,it will have rolling motion due to disturbance from waves.Based on ...A zero-speed fin stabilizer system was developed for rolling control of a marine robot.As a robot steering device near the sea surface with low speed,it will have rolling motion due to disturbance from waves.Based on the working principle of a zero-speed fin stabilizer and a marine robot’s dynamic properties,a roll damping controller was designed with a master-slave structure.It was composed of a sliding mode controller and an output tracking controller that calculates the desired righting moment and drives the zero-speed fin stabilizer.The methods of input-output linearization and model reference were used to realize the tracking control.Simulations were presented to demonstrate the validity of the control law proposed.展开更多
A novel seedling transplanting mechanism with planetary five-bar was developed in order to solve some problems when transplanting seedlings on mulch film,such as a large cave diameter,a low proportion of upright seedl...A novel seedling transplanting mechanism with planetary five-bar was developed in order to solve some problems when transplanting seedlings on mulch film,such as a large cave diameter,a low proportion of upright seedlings,and inconsistent planting depths,which seriously restrict the development of transplanting equipment used in dryland agriculture.The planetary five-bar structure of transplanting mechanism was designed based on analysis of the seedling transplanter on mulch film.The kinematics model of the transplanting mechanism was established and the optimal parameters of the transplanting mechanism were obtained by satisfying the motion trajectory conditions.Subsequently,the virtual prototype of transplanting mechanism was developed,and the simulation of motion trajectory was illustrated.Finally,the physical prototype of the transplanting mechanism was assembled and tested with the high-speed photography.The simulation results indicated that the desired“spindle”trajectory for the duckbill can be obtained,of which the height was 350 mm,and the diameter of the planting cave was 32 mm.The experimental results showed that the diameter of the planting cave was less than 70 mm,the seedling perpendicularity qualification rate reached 96%,the film injury rate was less than 0.5%,and the hanging membrane phenomenon was avoided.Therefore,the proposed transplanting mechanism can meet the requirements for a mulch-film transplanting machine.展开更多
基金Supported by the National Natural Science Foundation under Grant No50879012
文摘A zero-speed fin stabilizer system was developed for rolling control of a marine robot.As a robot steering device near the sea surface with low speed,it will have rolling motion due to disturbance from waves.Based on the working principle of a zero-speed fin stabilizer and a marine robot’s dynamic properties,a roll damping controller was designed with a master-slave structure.It was composed of a sliding mode controller and an output tracking controller that calculates the desired righting moment and drives the zero-speed fin stabilizer.The methods of input-output linearization and model reference were used to realize the tracking control.Simulations were presented to demonstrate the validity of the control law proposed.
基金the Open Fund of the State Key Laboratory of Mechanical Transmissions(Grant No.SKLMT-KFKT-201516)the National Natural Science Foundation of China(Grant No.51565048)the Chinese Technology Aid Project in Xinjiang(Grant No.2013AB013)。
文摘A novel seedling transplanting mechanism with planetary five-bar was developed in order to solve some problems when transplanting seedlings on mulch film,such as a large cave diameter,a low proportion of upright seedlings,and inconsistent planting depths,which seriously restrict the development of transplanting equipment used in dryland agriculture.The planetary five-bar structure of transplanting mechanism was designed based on analysis of the seedling transplanter on mulch film.The kinematics model of the transplanting mechanism was established and the optimal parameters of the transplanting mechanism were obtained by satisfying the motion trajectory conditions.Subsequently,the virtual prototype of transplanting mechanism was developed,and the simulation of motion trajectory was illustrated.Finally,the physical prototype of the transplanting mechanism was assembled and tested with the high-speed photography.The simulation results indicated that the desired“spindle”trajectory for the duckbill can be obtained,of which the height was 350 mm,and the diameter of the planting cave was 32 mm.The experimental results showed that the diameter of the planting cave was less than 70 mm,the seedling perpendicularity qualification rate reached 96%,the film injury rate was less than 0.5%,and the hanging membrane phenomenon was avoided.Therefore,the proposed transplanting mechanism can meet the requirements for a mulch-film transplanting machine.
