基于六自由度并联机构的动态倾角校准方法研究

Tilt sensors measure angular tilt in reference to gravity and are used in a wide variety of applications of buildings, aviation, aerospace and automation fields. Recently, demand for high-performance and multi-component tilt sensors is becoming higher. In order to acquire actual response performance of the tilt sensor, it’s necessary to develop the actual measurement environment tilt calibration technique. The purpose of this project is to study the dynamic tilt calibration method based on the 6-DOF parallel manipulator. Firstly, the motion trajectory control strategy of the 6-DOF parallel manipulator is presented. The mutual coupling and interference between the driving joints is compensated. Accurately control for all the degree of freedom sinusoidal motion of the terminal platform is realized. Based upon, high-precision standard position and posture motion trajectory is synthesized. Then, the 6 dimensional sensitive model of the tilt sensor is established. The parameters of the established sensitive model are identified by setting up the standard position and posture motion trajectory library. The 6 dimensional dynamic calibration method of the tilt sensor is put forward. The proposed method is beneficial to acquire the actual response performance of the tilt sensor for the validity and reliability of tilt measurement system and satisfy the urgent demand for the high-performance tilt sensor in various fields.

倾角传感器用于测量安装面相对于水平面的夹角，广泛应用于建筑、航空、航天及自动化领域。随着各种高性能、多分量倾角传感器的日益增多，为了获得倾角传感器的真实响应特性，需要大力发展接近实际测量环境的倾角校准技术。本项目拟对基于六自由度并联机构的动态倾角校准技术进行研究。研究六自由度校准并联机构的运动轨迹控制策略，补偿各驱动关节的相互耦合与干扰，精确控制终端平台各自由度正弦运动的幅值和相位，实现高精度标准位置和姿态运动轨迹的合成。建立倾角传感器的六维空间敏感模型，通过创建标准位姿运动轨迹库，实现六维空间敏感模型的参数识别，建立倾角传感器六维空间的动态校准方法，获取传感器实际测量环境的响应特性，保证倾角测量系统的有效性和可靠性，满足各工程应用领域对高性能倾角传感器的迫切需求。

动态倾角传感器由三轴向加速度计和三轴向陀螺仪组成，通过数据融合算法实时输出动态倾角。本项目围绕倾角传感器的动态校准问题，对多自由度运动轨迹控制和基于空间运动轨迹的动态校准方法进行了深入研究。提出多点激励正弦运动轨迹控制方法，实现了各轴振动幅值和相位精确控制，建立了空间运动轨迹与各轴运动分量的函数映射关系。提出多点激励随机振动设置参考谱矩阵复相干系数的约束圆方法，明确复相干系数的取值范围，解决了参考谱矩阵正定性判断的缺点。提出加速度灵敏度矢量的椭圆运动轨迹测试方法，通过不同姿态和形状的椭圆运动轨迹实现校准，避免传感器重新安装引起的基座应力改变、重力对传感器机械部件的影响、降低校准效率等不足。提出倾角传感器基于Stewart平台的圆锥运动轨迹测试方法，通过圆锥运动轨迹和位置运动轨迹测，分别测试倾角传感器的动态跟踪特性和交叉耦合影响。