In the aerospace field, electromechanical actuators are increasingly being implemented in place of conventional hydraulic actuators. For safety-critical embedded actuation applications like flight controls, the use of...In the aerospace field, electromechanical actuators are increasingly being implemented in place of conventional hydraulic actuators. For safety-critical embedded actuation applications like flight controls, the use of electromechanical actuators introduces specific issues related to thermal balance, reflected inertia, parasitic motion due to compliance and response to failure. Unfortunately, the physical effects governing the actuator behaviour are multidisciplinary, coupled and nonlinear. Although numerous multi-domain and system-level simulation packages are now available on the market, these effects are rarely addressed as a whole because of a lack of scientific approaches for model architecting, multi-purpose incremental modelling and judicious model implementation. In this publication, virtual prototyping of electromechanical actuators is addressed using the Bond-Graph formalism. New approaches are proposed to enable incremental modelling,thermal balance analysis, response to free-run or jamming faults, impact of compliance on parasitic motion, and influence of temperature. A special focus is placed on friction and compliance of the mechanical transmission with fault injection and temperature dependence. Aileron actuation is used to highlight the proposals for control design, energy consumption and thermal analysis, power network pollution analysis and fault response.展开更多
绝缘子检测是保障输电系统安全稳定的重要措施,绝缘子定位是进行检测的前提。针对目前电力巡检中绝缘子定位速度慢、精度低的问题,提出了一种基于GDIoU(Gaussian Distance Intersection over Union)损失函数的YOLOv4深度学习框架。该方...绝缘子检测是保障输电系统安全稳定的重要措施,绝缘子定位是进行检测的前提。针对目前电力巡检中绝缘子定位速度慢、精度低的问题,提出了一种基于GDIoU(Gaussian Distance Intersection over Union)损失函数的YOLOv4深度学习框架。该方案通过设计GDIoU损失函数来提高YOLOv4的定位精度和收敛速度,利用二维高斯模型提高了网络的收敛能力,增强了YOLOv4的性能,进而提高了绝缘子的定位精度与速度。同时提出绝缘子自适应旋转矫正算法,通过对单个绝缘子图像进行旋转矫正,提升了在不同空间状态下的绝缘子识别精度。实验结果表明,与朴素YOLOv4相比,所提算法的定位精度提高了7.37%。在同水平的精度下,基于GDIoU的YOLOv4绝缘子定位方法比其他绝缘子定位算法速度快了3倍以上。所提方法在精度与速度上做了较好的平衡,其性能完全满足电力巡检中绝缘子的在线定位要求。展开更多
基金supported by the Aeronautical Science Foundation of China (No. 2012ZD51)the support of the China Scholarship Council (CSC)
文摘In the aerospace field, electromechanical actuators are increasingly being implemented in place of conventional hydraulic actuators. For safety-critical embedded actuation applications like flight controls, the use of electromechanical actuators introduces specific issues related to thermal balance, reflected inertia, parasitic motion due to compliance and response to failure. Unfortunately, the physical effects governing the actuator behaviour are multidisciplinary, coupled and nonlinear. Although numerous multi-domain and system-level simulation packages are now available on the market, these effects are rarely addressed as a whole because of a lack of scientific approaches for model architecting, multi-purpose incremental modelling and judicious model implementation. In this publication, virtual prototyping of electromechanical actuators is addressed using the Bond-Graph formalism. New approaches are proposed to enable incremental modelling,thermal balance analysis, response to free-run or jamming faults, impact of compliance on parasitic motion, and influence of temperature. A special focus is placed on friction and compliance of the mechanical transmission with fault injection and temperature dependence. Aileron actuation is used to highlight the proposals for control design, energy consumption and thermal analysis, power network pollution analysis and fault response.
文摘绝缘子检测是保障输电系统安全稳定的重要措施,绝缘子定位是进行检测的前提。针对目前电力巡检中绝缘子定位速度慢、精度低的问题,提出了一种基于GDIoU(Gaussian Distance Intersection over Union)损失函数的YOLOv4深度学习框架。该方案通过设计GDIoU损失函数来提高YOLOv4的定位精度和收敛速度,利用二维高斯模型提高了网络的收敛能力,增强了YOLOv4的性能,进而提高了绝缘子的定位精度与速度。同时提出绝缘子自适应旋转矫正算法,通过对单个绝缘子图像进行旋转矫正,提升了在不同空间状态下的绝缘子识别精度。实验结果表明,与朴素YOLOv4相比,所提算法的定位精度提高了7.37%。在同水平的精度下,基于GDIoU的YOLOv4绝缘子定位方法比其他绝缘子定位算法速度快了3倍以上。所提方法在精度与速度上做了较好的平衡,其性能完全满足电力巡检中绝缘子的在线定位要求。
