基于冗余并联机构的压电式六维加速度传感器研究

发布时间：2018-03-09 15:56

  本文选题：六维加速度传感器　切入点：并联机构　出处：《南京航空航天大学》2013年博士论文　论文类型：学位论文

【摘要】：生物医学、惯性导航、机器人等领域正朝着高、精、尖的性能方向发展,迫切需要六维加速度传感器这类能够同时获取载体多自由度运动信息的测量系统,目前国内外对其研究尚处于原理探索阶段,主要技术瓶颈在于解耦难度与结构复杂度之间存在矛盾。针对该现状,本文提出了一种基于冗余并联机构的压电式六维加速度传感器,拥有自主知识产权,从构型设计、解耦算法、结构优化、参数辨识四个方面对其作了深入的研究和探讨。提出了一种基于四面体构型的9-SPS冗余并联机构,运用螺旋理论、拓扑理论等现代机构学理论对其展开分析,结果表明新型并联机构具有初始位姿空间内零奇异、运动学正解封闭、冗余信息可用于处理次级噪声、解耦特性优越以及拓扑构型紧凑且对称等众多优点。鉴于此,用该构型的并联机构充当六维加速度传感器的弹性体结构,另外,压电陶瓷同时充当敏感元件和移动副,弹性球铰链充当球面副。在上述方案的指导下设计了六维加速度传感器的原理样机,并制作了一台加工成本和安装精度要求都较低的实物样机。分别在位形空间内运用矢量力学方法以及在相空间内运用分析力学方法推导出系统的动力学方程;在同伦思想的启发下,通过引入辅助角速度,解决了牛顿-欧拉方程中输入输出量耦合程度高的问题;通过挖掘出姿态四元数与其对应的广义动量之间“隐藏”着的正交关系,在不破坏原动力学方程平衡性的前提下,解决了涉及到哈密顿约束正则方程的指标-3问题;构建了六维加速度传感器的两类解耦算法,它们均具有解耦效率高和算法适应性强的优点。考虑到两类解耦算法在数值性态上存在较大差异,从定性和定量两个角度进行了全面地对比,并分析了造成两者差异的原因,对比结果可用于指导传感器在具体应用场合下对解耦算法的合理选取。通过以定义出的结构矩阵为乘子的迭代运算,同时获取到系统的基频和一阶主振型,巧妙避开传统算法中需要求解高次方程的复杂工作,具有计算效率高和绝对收敛的优点。通过添加关于构型自身冗余约束关系的协调方程,解算了超静定反向动力学方程,从而推导出灵敏度关于结构参数的解析表达式,同时得出所设计传感器理论灵敏度各向同性的结论。提出并证明了关于误差区间宽度的三个定理,据此揭示并量化了六维加速度传感器的误差传递关系,一定程度上拓展了区间分析法的应用领域。为解决多目标优化过程中普遍存在的三大问题,在基频、灵敏度及误差传递模型的基础上提出了一种综合性能函数,据此绘制了六维加速度传感器的性能图谱,对传感器的结构优化以及定量评价具有较大的参考价值。通过深入剖析解耦算法中间参量的形成机理后发现,在线阈频和角阈频之下分别激励外壳做纯线运动和纯角运动时,系统动力学方程可以简化成只关于部分解耦参数的线性代数方程。据此提出了一种可用于对并联式六维加速度传感器的25个解耦参数实施分组辨识的“四步法”。考虑到目前市场上还没有能够与“四步法”相匹配的外部激励设备,研制了基于双曲柄滑块机构的新型试验平台,且同样拥有自主知识产权。将传感器实物样机安装在试验平台上,并运用自行开发的虚拟仪器控制参数辨识试验的全过程。试验结果显示,参数辨识之后解耦误差降低了1个数量级,表明“四步法”是有效的、可行的。最后,通过软件仿真和样机试验验证了本文所提出设计方案的合理性以及所建立运动学模型、动力学模型的可靠性。本文解决了六维加速度传感器研制过程中涉及到的一些关键技术问题,为促进其仪器化、实用化进程奠定了理论基础;同时,通过对研究结果的进一步扩展或修正,还可为其它类型多维传感器的设计及分析提供理论指导。
[Abstract]:Biomedical, inertial navigation, robotics and other fields toward the high, fine, sharp direction of performance development, the urgent need of six axis accelerometer measurement system which can obtain the support of multi degree of freedom motion information, current research at home and abroad for its principle is still in the stage of exploration, the main technical bottleneck lies in the difficulty and complicated structure decoupling between the degree of conflict. Aiming at this situation, this paper proposes a redundant parallel mechanism of piezoelectric six axis accelerometer based on independent intellectual property rights, from the configuration design, decoupling algorithm, structure optimization, parameter identification of four aspects of the in-depth study and discussion. This paper proposes a redundant parallel 9-SPS mechanism of tetrahedral configuration based on the use of screw theory, topological theory and other modern mechanism theory to analyze the results show that the new parallel mechanism with initial pose space zero singular Closed, kinematics, redundant information can be used to treat the secondary noise, many excellent characteristics and advantages of decoupling topology is compact and symmetrical. In view of this, as the elastic body structure of six axis accelerometer with the configuration of the parallel mechanism in addition, piezoelectric ceramics also act as the sensitive element and the mobile side, elastic ball as spherical hinge deputy. In this program under the guidance of the principle prototype design of six axis accelerometer, and produced a prototype of a machining cost and installation accuracy requirements are lower in vector mechanics respectively. Using the space and using the kinetic equations of analytical mechanics method to derive the system in phase space; inspired homotopy thought, by introducing an auxiliary angular velocity, solve the input and output of the high degree of coupling problem of Newton Euler equations; through mining four yuan and the number of attitude The orthogonal relationship between "generalized momentum should be hidden, without destroying the original balance of kinetic equation, solving the Hamiltonian constraint equation involves regular index -3; constructed two decoupling algorithms for six dimensional acceleration sensor, has high efficiency and decoupling algorithm adaptability they consider. Two decoupling algorithms are quite different in the value condition, make a comprehensive comparison from two aspects of qualitative and quantitative, and then analyzes the causes of the difference, the results can be used to guide the sensor in the specific applications of decoupling algorithm. Through the reasonable selection of structure matrix to define the multiplication the iterative operation, and access to the system of fundamental frequency and first order vibration mode, cleverly avoiding complex work need high equation in the traditional algorithm has high computational efficiency and absolute convergence. The advantages. By adding the coordination equation about the configuration of its redundant constraints, calculated indeterminate reverse kinetic equation, analytical expressions to derive the sensitivity of structure parameters, at the same time that the design theory of sensor sensitivity isotropy. The conclusion presents and proves three theorems about the error interval width, can be revealed and quantified six axis accelerometer error transfer relationship to a certain extent, expand the application field of interval analysis. Three main problems exist, to solve multi-objective optimization in the process of fundamental frequency, sensitivity and error transfer based on the model proposed an integrated performance function, thus draw the performance atlas of six axis accelerometer, which is valuable for the structure optimization of sensor and quantitative evaluation. Through in-depth analysis of the formation of intermediate parameter decoupling algorithm The mechanism that online under the threshold frequency and angle threshold frequency were pure line movement and shell excitation of pure angular motion, dynamic equations of the system can be simplified into only on the part of decoupling parameter of linear algebraic equations. It can be used to propose a 25 decoupling parameter of parallel type six axis accelerometer packet identification the "four step". Considering the present outside the market has not been able to match with the "four step" incentive device, developed a new test platform based on double crank mechanism, and also has independent intellectual property rights. The prototype sensor installed on the test platform, the whole process is developed by using virtual instrument control the parameter identification test. The test results show that the parameter identification after decoupling error is reduced by 1 orders of magnitude, that the "four step" is effective and feasible. Finally, through the simulation software The prototype test and verify that the rationality of the design scheme and the kinematics model, kinetics model. This paper solves some key technical problems of the six axis accelerometer development involved in the process, in order to promote its instruments, practical process laid a theoretical foundation; at the same time, through further expansion or modification the results of the study, but also provide theoretical guidance for the design and analysis of other types of multi sensors.

【学位授予单位】：南京航空航天大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TP212
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本文编号：1589213