Based on rational behavior model of three layers, a tracking control system is designed for straight line tracking which is commonly used in underwater survey missions. An intelligent PID control law implemented as pl...Based on rational behavior model of three layers, a tracking control system is designed for straight line tracking which is commonly used in underwater survey missions. An intelligent PID control law implemented as planning level during the control system using transverse deviation is came up with. Continuous tracking of path expressed by a point sequence can be realized by the law. Firstly, a path tracking control system based on rational behavior model of three layers is designed, mainly satisfying the needs of underactuated AUV. Since there is no need to perform spatially coupled maneuvers, the 3D path tracking control is decoupled into planar 2D path tracking and depth or height tracking separately. Secondly, planar path tracking controller is introduced. For the reason that more attention is paid to comparing with vertical position control, transverse deviation in analytical form is derived. According to the Lyapunov direct theory, control law is designed using discrete PID algorithm whose parameters obey adaptive fuzzy adjustment. Reference heading angle is given as an output of the guidance controller conducted by lateral deviation together with its derivative. For the purpose of improving control quality and facilitating parameter modifying, data normalize modules based on Sigmoid function are applied to input-output data manipulation. Lastly, a sequence of experiments was carried out successfully, including tests in Longfeng lake and at the Yellow sea. In most challenging sea conditions, tracking errors of straight line are below 2 m in general. The results show that AUV is able to compensate the disturbance brought by sea current. The provided test results demonstrate that the designed guidance controller guarantees stably and accurately straight route tracking. Besides, the proposed control system is accessible for continuous comb-shaped path tracking in region searching.展开更多
太阳跟踪器推杆产生的冲击载荷会引起结构振动,由振动变形导致的跟踪偏差对系统的发电效率影响十分显著。作者采用ANSYS软件对20 k W级双轴太阳跟踪器进行结构动力学分析,讨论了太阳跟踪器前6阶的模态参数,并计算了太阳跟踪器在冲击载...太阳跟踪器推杆产生的冲击载荷会引起结构振动,由振动变形导致的跟踪偏差对系统的发电效率影响十分显著。作者采用ANSYS软件对20 k W级双轴太阳跟踪器进行结构动力学分析,讨论了太阳跟踪器前6阶的模态参数,并计算了太阳跟踪器在冲击载荷作用下的振动响应特性。研究结果表明:太阳跟踪器的固有频率随高度角的变化不明显,第2阶、第5阶振型对结构的振动变形影响较大;在冲击载荷作用下,结构的最大振动位移为26 mm,对应的偏差角为0.33°,小于控制要求的0.5°,结构振动对跟踪器的发电效率影响较小。展开更多
基金Projects(51179035,51279221) supported by the National Natural Science Foundation of ChinaProject(2014M561333) supported by Postdoctoral Science Foundation of China
文摘Based on rational behavior model of three layers, a tracking control system is designed for straight line tracking which is commonly used in underwater survey missions. An intelligent PID control law implemented as planning level during the control system using transverse deviation is came up with. Continuous tracking of path expressed by a point sequence can be realized by the law. Firstly, a path tracking control system based on rational behavior model of three layers is designed, mainly satisfying the needs of underactuated AUV. Since there is no need to perform spatially coupled maneuvers, the 3D path tracking control is decoupled into planar 2D path tracking and depth or height tracking separately. Secondly, planar path tracking controller is introduced. For the reason that more attention is paid to comparing with vertical position control, transverse deviation in analytical form is derived. According to the Lyapunov direct theory, control law is designed using discrete PID algorithm whose parameters obey adaptive fuzzy adjustment. Reference heading angle is given as an output of the guidance controller conducted by lateral deviation together with its derivative. For the purpose of improving control quality and facilitating parameter modifying, data normalize modules based on Sigmoid function are applied to input-output data manipulation. Lastly, a sequence of experiments was carried out successfully, including tests in Longfeng lake and at the Yellow sea. In most challenging sea conditions, tracking errors of straight line are below 2 m in general. The results show that AUV is able to compensate the disturbance brought by sea current. The provided test results demonstrate that the designed guidance controller guarantees stably and accurately straight route tracking. Besides, the proposed control system is accessible for continuous comb-shaped path tracking in region searching.
文摘太阳跟踪器推杆产生的冲击载荷会引起结构振动,由振动变形导致的跟踪偏差对系统的发电效率影响十分显著。作者采用ANSYS软件对20 k W级双轴太阳跟踪器进行结构动力学分析,讨论了太阳跟踪器前6阶的模态参数,并计算了太阳跟踪器在冲击载荷作用下的振动响应特性。研究结果表明:太阳跟踪器的固有频率随高度角的变化不明显,第2阶、第5阶振型对结构的振动变形影响较大;在冲击载荷作用下,结构的最大振动位移为26 mm,对应的偏差角为0.33°,小于控制要求的0.5°,结构振动对跟踪器的发电效率影响较小。
