重载并联稳定平台构型综合与轨迹规划研究

发布时间：2017-12-31 21:38

本文关键词：重载并联稳定平台构型综合与轨迹规划研究　出处：《燕山大学》2015年博士论文　论文类型：学位论文

【摘要】：火箭在海洋运输过程中,受到海浪扰动的影响,会产生较大的倾斜和振动。稳定平台可以隔离船体摇荡对箭体的作用,保证箭体及箭载设备的运输安全。本文针对现有稳定平台产品载荷小,难以用于火箭运输的问题开展研究,主要内容如下:对并联机构的力传递性和承载能力进行了分析。给出并联机构力传递性的概念,定义了力传递性评价指标,提出一种计算标准化模型所能承受最大外力极值的方法。根据运动形式的不同,将并联机构的承载能力分为静态承载能力和动态承载能力,并给出计算方法。力传递性和承载能力相结合,可为重载并联机构的设计和评价提供指导。对适用于重载的并联机构多输入驱动方式进行了研究。首先根据冗余驱动力性质和对动平台作用效果的不同,提出两种冗余驱动的分类方法。基于不同类型的冗余驱动,综合出动平台静载平衡伴随冗余驱动、关节静载平衡伴随冗余驱动、重力平衡主动冗余驱动三种适用于重载的冗余驱动方式。提出一种多输入非冗余驱动方式,综合出多输入非冗余驱动单元和驱动分支。以上述驱动方式为基础构造了六种并联机构,对于其中分支自由度大于6的3(2UPS-R)/PU机构进行了详细分析。基于旋量理论开展非惯性系下并联机构跃度的研究。定义了刚体的空间跃度、物体跃度和耦合物体跃度,并证明空间跃度和耦合物体跃度是旋量,而物体跃度不是旋量。推导出多刚体系统的跃度伴随变换和伴随映射表达式,得到了稳定平台系统各刚体间的跃度变换关系。建立了并联机构跃度映射模型,得到表征这种映射的三阶影响系数矩阵。结合稳定平台系统刚体之间跃度变换和并联机构跃度映射,得到了非惯性系下并联机构的跃度映射模型。根据刚体角速度与欧拉角时间导数的关系,建立了刚体角跃度与欧拉角三阶时间导数的映射。研究了非惯性系下稳定平台的轨迹规划方法。利用准均匀分布B样条曲线的特点,建立了动平台运动参数的线性约束,以动平台跃度与稳定平台主动关节跃度的加权平方和最小为目标求解样条曲线的控制顶点,进而得到运输过程中动平台相对惯性系的运动规律。介绍了稳定平台地面试验系统的电气和软件控制系统。参与研制了地面试验系统,在此基础上开展实验研究,验证了增加配重可以有效的提高机构的承载能力。将稳定平台动平台在惯性系中的等效运动在地面试验系统上实现,验证了所得运动轨迹的可行性。
[Abstract]:In the process of ocean transportation, the rocket will be inclined and vibrated by the wave disturbance, and the stable platform can isolate the effect of the ship rocking on the arrow body. In order to ensure the transportation safety of arrows and arrow-borne equipment, this paper aims at the problem that the product of the existing stable platform has small load and is difficult to be used in rocket transportation. The main contents are as follows: the force transfer and bearing capacity of parallel mechanism are analyzed, the concept of force transfer of parallel mechanism is given, and the evaluation index of force transfer is defined. A method for calculating the maximum external force extremum of the standardized model is proposed. According to the different motion forms, the bearing capacity of the parallel mechanism is divided into static bearing capacity and dynamic bearing capacity. The calculation method, the combination of force transitivity and bearing capacity are also given. It can provide guidance for the design and evaluation of heavy-load parallel mechanism. The multi-input drive mode suitable for heavy load parallel mechanism is studied. Firstly, according to the nature of redundant driving force and the different effect on moving platform. Two kinds of redundant driving classification methods are proposed. Based on different types of redundant drivers, combined platform static load balance accompanied by redundant drive, joint static load balance accompanied with redundant drive. There are three redundant driving modes for heavy-duty gravity balancing active redundancy drive. A multi-input non-redundant drive mode is proposed. The multi-input non-redundant drive units and driving branches are synthesized and six kinds of parallel mechanisms are constructed based on the above driving modes. Based on spinor theory, the jump degree of parallel mechanism under non-inertial frame is studied in detail. The spatial hopping of rigid body is defined. It is proved that the spatial hops and coupled hops are spinor, but the hops are not spinor. The expressions of the adjoint transformation and adjoint mapping for multi-rigid body systems are derived. The hops transformation relationship among the rigid bodies of the stable platform system is obtained, and the jump mapping model of the parallel mechanism is established. The third-order influence coefficient matrix representing this mapping is obtained, which combines the hop transformation between rigid bodies of stable platform system and the hop mapping of parallel mechanism. Based on the relationship between angular velocity of rigid body and time derivative of Euler angle, the jump mapping model of parallel mechanism under non-inertial system is obtained. The mapping between angular hops of rigid body and the third order time derivative of Euler angle is established. The trajectory planning method of stable platform under non-inertial frame is studied. The characteristic of quasi-uniform distribution B-spline curve is used. The linear constraint of the moving platform motion parameters is established, and the control points of the spline curve are solved with the minimum of the weighted square sum of the moving platform jump and the stable platform active joint jump. Then the motion law of the moving platform relative to the inertial system is obtained. The electrical and software control system of the ground test system of the stabilized platform is introduced and the ground test system is developed. On this basis, the experimental research is carried out, which proves that increasing the counterweight can effectively improve the bearing capacity of the mechanism. The equivalent motion of the stable platform in the inertial system is realized on the ground test system. The feasibility of the motion trajectory is verified.
【学位授予单位】：燕山大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TB535;V553.19

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