共查询到19条相似文献,搜索用时 939 毫秒
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大摩擦情况下三轴飞行模拟转台QFT鲁棒控制器的设计 总被引:4,自引:0,他引:4
三轴飞行模拟转台是用于飞行控制系统半实物仿真的高性能位置跟踪和速度跟踪的一个重要设备。摩擦力和不确定性是三轴飞行模拟转台伺服系统的主要特性。在基于转台的动态和静态非线性Stribeck摩擦模型描述的基础上 ,考虑转台伺服系统的实际不确定性 ,设计了QFT鲁棒控制器 ,并给出了仿真和实时控制效果。 相似文献
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模拟转台是飞行器物理仿真实验中的主要仿真设备。随着飞行器性能的不断提高,对于模拟转台诸如:快速性、动态精度等性能指标提出了愈来愈高的要求,而在转台拖动系统设计中,一般延用的经典调节原理的设计方法不易得到一个十分理想的拖动系统。本文对于磁粉离合作为拖动部件的模拟转台提出了一种采用现代控制理论的方法,设计拖动系统的方案,首先建立被控对象的转台的状态方程模型,由于要求拖动系统能使转台运动跟踪给定的动态模型,所以是一个典型的跟踪问题。在此采用增广系统的方法,将状态跟踪问题转化为状态调节问题,然后在稳态二次型指标下进行优化设计,给出系统中的各个返馈与前馈系数,同时提出一种根据系统精度要求而确定二次型指标中的权系数的方法。从初步的系统数学仿真结果看:在快速性及跟踪精度方面都有很大的提高。 相似文献
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提出了一种用于精密转台平滑鲁棒自适应控制器。通过基于σ改进方案的自适应律估计得到未知摩擦参数和非线性项的常值上界,并且利用一种平滑预测算法来改进用于估计不可测摩擦状态的双观测器。为了抑制不确定非线性项,加入了无抖振滑模控制项。通过Lyapunov方法证明了系统的位置跟踪误差是一致最终有界的。仿真研究表明了该控制方案的有效性。 相似文献
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通过摩擦补偿的分析提出了一种基于非线性摩擦模型参数观测器的自适应摩擦补偿方法,从工程实用角度出发采用的是库仑加粘滞的摩擦模型,设计了两个观测器实现对库仑摩擦系数和粘滞摩擦系数的估计,并用MATLAB软件对转台工作状态进行了仿真,结果表明此观测器有良好的自适应补偿性能。 相似文献
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针对转台运动系统中存在的摩擦力环节及其特性提出了一种静态摩擦力模型及其参数辨识方法,该模型克服了库伦摩擦模型的不连续性,并利用该模型对摩擦力在转台伺服系统中的影响,进行了仿真分析及试验对比。结果表明,该摩擦力模型可充分描述摩擦力对转台伺服系统运动性能的影响,为进一步提高系统的运动性能提供了一个研究基础。 相似文献
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基于名义模型的飞行模拟转台反演滑模控制 总被引:7,自引:0,他引:7
针对飞行模拟转台这一实际的不确定伺服系统,提出一种新型控制策略,该控制策略是建立在名义模型基础上的一种新型全鲁棒滑模控制器.控制系统由两种控制器构成,一种是针对实际对象的全鲁棒滑模控制器,另一种是针对名义模型的积分反演滑模控制器.采用名义模型与实际对象之间的建模误差设计全鲁棒滑模控制器,采用积分反演滑模控制器来保证控制精度,全鲁棒性能由全局滑模控制器来保证.采用Lyapunov方法实现了两种控制器的稳定性分析.以飞行模拟转台伺服系统为被控对象,针对正弦和阶跃响应的仿真结果表明,采用所提出的控制方法,可实现全局鲁棒性并保证较高的位置跟踪精度. 相似文献
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为研究球柱联合转台轴承摩擦力矩特性,建立了轴承的力学模型,采用Newton-Raphson法对模型进行求解。分析了轴承摩擦力矩产生机理,建立了摩擦力矩计算模型,利用试验机对模型进行了试验验证,研究了不同结构参数对轴承摩擦力矩的影响。结果表明:所建立的模型可较好的实现轴承摩擦力矩预测,轴承摩擦力矩与轴向载荷、倾覆力矩和轴承转速呈正相关;减小初始轴向游隙可显著降低轴承摩擦力矩;钢球数量存在一个最优值使轴承摩擦力矩最小;沟曲率半径存在合理区间使轴承综合性能最优;适当减小保持架质量可有效降低轴承摩擦力矩。研究结果为球柱联合转台轴承的优化设计提供了理论依据。 相似文献
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To overcome the influence of the nonlinear friction on the gimbaled servo-system of an inertial stabilized platforms(ISPs) with DC motor direct-drive, the methods of modeling and compensation of the nonlinear friction are proposed. Firstly, the inapplicability of LuGre model when trying to interpret the backward angular displacement in the prestiction regime is observed experimentally and the reason is deduced theoretically. Then, based on the dynamic model of direct-drive ISPs, a modified LuGre model is proposed to describe the characteristic of the friction in the prestiction regime. Furthermore, the state switch condition of the three friction regimes including presliding, gross sliding and prestiction is presented. Finally, a composite compensation controller including a nonlinear friction observer and a feedforward compensator based on the novel LuGre model is designed to restrain the nonlinear friction and to improve the control precision. Experimental results indicate that compared with those of the conventional proportion–integration–differentiation(PID) control method and the PID plus LuGre model-based friction compensation method, the dwell-time has decreased from 0.2 s to almost 0 s, the position error decreased to 86.7%and the peak-to-peak value of position error decreased to 80% after the novel compensation controller is added. It concludes that the composite compensation controller can greatly improve the control precision of the dynamic sealed ISPs. 相似文献
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空间机械臂关节具有大惯量、高精度的特点,针对空间机械臂关节低速、高精度控制要求,提出一种基于摩擦补偿的双位置闭环控制策略。建立了考虑摩擦和惯量变化等因素的一体化关节动力学模型,分析了全位置闭环系统的稳定性,在此基础上提出了一种基于双位置传感器信息的闭环伺服控制策略,并引入自适应率辨识未知摩擦和惯量变化,利用Lyapunov函数证明闭环系统的稳定性和跟踪误差的渐进收敛性。在测试平台上的试验结果表明,提出的空间机械臂一体化关节伺服控制策略能够有效地提高关节伺服控制精度和系统鲁棒性。 相似文献
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The real dynamic thrust measurement system usually tends to be nonlinear due to the complex characteristics of the rig, pipes connection, etc. For a real dynamic measuring system,the nonlinearity must be eliminated by some adequate methods. In this paper, a nonlinear model of dynamic thrust measurement system is established by using radial basis function neural network(RBF-NN), where a novel multi-step force generator is designed to stimulate the nonlinearity of the system, and a practical compensation method for the measurement system using left inverse model is proposed. Left inverse model can be considered as a perfect dynamic compensation of the dynamic thrust measurement system, and in practice, it can be approximated by RBF-NN based on least mean square(LMS) algorithms. Different weights are set for producing the multi-step force, which is the ideal input signal of the nonlinear dynamic thrust measurement system. The validity of the compensation method depends on the engine’s performance and the tolerance error0.5%, which is commonly demanded in engineering. Results from simulations and experiments show that the practical compensation using left inverse model based on RBF-NN in dynamic thrust measuring system can yield high tracking accuracy than the conventional methods. 相似文献
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Friction compensation for low velocity control of hydraulic flight motion simulator: A simple adaptive robust approach 总被引:1,自引:1,他引:0
Low-velocity tracking capability is a key performance of flight motion simulator (FMS), which is mainly affected by the nonlinear friction force. Though many compensation schemes with ad hoc friction models have been proposed, this paper deals with low-velocity control without friction model, since it is easy to be implemented in practice. Firstly, a nonlinear model of the FMS middle frame, which is driven by a hydraulic rotary actuator, is built. Noting that in the low velocity region, the unmodeled friction force is mainly characterized by a changing-slowly part, thus a simple adaptive law can be employed to learn this changing-slowly part and compensate it. To guarantee the boundedness of adaptation process, a discontinuous projection is utilized and then a robust scheme is proposed. The controller achieves a prescribed output tracking transient performance and final tracking accuracy in general while obtaining asymptotic output tracking in the absence of modeling errors. In addition, a saturated projection adaptive scheme is proposed to improve the globally learning capability when the velocity becomes large, which might make the previous proposed projection-based adaptive law be unstable. Theoretical and extensive experimental results are obtained to verify the high-performance nature of the proposed adaptive robust control strategy. 相似文献