智能球铰链空间回转角度测量及精度提升技术

发布时间：2018-10-19 12:18

【摘要】：球铰链具有三个回转自由度,可实现任意方向的自由转动,同时具有结构紧凑、刚度较高、运动灵活、承载能力强、工作空间大等特点,广泛应用于机器人、并联机构、并联机床和并联测量机等。球铰链空间回转角度的检测对机构的运动误差预测分析、反馈和姿态控制具有十分重要的意义,目前,球铰链空间回转角度的高精度检测还缺少方法。在不影响球铰链承重能力、回转精度、运动灵活性等关键指标的前提下,本文研制了一种基于磁效应的嵌入式智能球铰链,将永磁体嵌入在球头内、若干霍尔传感器嵌入在球窝中,永磁体随球杆一起转动,传感器检测其所在位置变化的磁场,根据磁场理论知识建模、反解,实现球铰链空间回转角度的辨识和测量。本论文主要做了以下工作:基于等效磁荷模型分别建立了以单个、多个永磁体为磁场源的外部空间磁场分布表达式;结合矩阵旋转理论完成了球铰链空间回转角度测量的理论模型的构建;为单个、多个永磁体模型选定了适当的数值积分算法,也为反解函数fsolve选取了有效的初值设置方法;确定了永磁体的形状和霍尔传感器的放置方式,通过Matlab仿真得出了传感器与永磁体的最佳匹配位置;设计并制作了项目组的第一台嵌入式球铰链样机,经实验比对装置分析了样机的测量精度和分辨率。实验数据表明,在球铰链转角较小时,α和β角度的测量精度较高,量程增大后,测量误差随之增大,在±10°旋转范围以内,α的最大误差为32.34′,最小误差为0.12′,平均误差为11.58′,β的最大误差为26.16′,最小误差为-0.24′,平均误差为12.06′;在±20°范围以内,α和β的平均误差分别为18.84′和20.34′。和前期研究成果相比,该测量方法的量程、测量精度和分辨率都有提高,基本具备在中、低精度要求场合应用的条件。
[Abstract]:The spherical hinge has three degrees of freedom of rotation, can realize free rotation in any direction, and has the characteristics of compact structure, high stiffness, flexible motion, strong bearing capacity, large workspace and so on. It is widely used in robot and parallel mechanism. Parallel machine tool and parallel measuring machine, etc. The detection of spherical hinge space rotation angle is of great significance to the prediction, feedback and attitude control of the motion error of the mechanism. At present, there is still a lack of methods to detect the spherical hinge space rotation angle with high precision. In this paper, a kind of embedded intelligent ball hinge based on magnetic effect is developed, which embeds the permanent magnet into the ball head without affecting the key indexes such as the bearing capacity of the ball hinge, the precision of rotation and the flexibility of movement, and so on, in this paper, a kind of embedded intelligent ball hinge based on magnetic effect is developed. A number of Hall sensors are embedded in the ball nest and the permanent magnet rotates with the ball rod. The sensor detects the magnetic field of its position changes. According to the theory of magnetic field modeling and inverse solution the spherical hinge space rotation angle can be identified and measured. The main work of this thesis is as follows: based on the equivalent magnetic charge model, the expressions of the external magnetic field distribution with single and multiple permanent magnets as magnetic field sources are established respectively; The shape of permanent magnet and the placement mode of Hall sensor are determined. The optimal matching position between the sensor and permanent magnet is obtained by Matlab simulation, and the first embedded spherical hinge prototype of the project team is designed and manufactured. The measuring accuracy and resolution of the prototype are analyzed by the experimental comparison device. The experimental data show that when the angle of spherical hinge is small, the measurement accuracy of 伪 and 尾 angle is higher, and the measurement error increases with the increase of measuring range. In the range of 卤10 掳rotation, the maximum error of 伪 is 32.34, and the minimum error is 0.12. The average error is 11.58, the maximum error of 尾 is 26.16, the minimum error is -0.24 and the average error is 12.060.The average error of 伪 and 尾 is 18.84 'and 20.34' respectively within 卤20 掳. Compared with the previous research results, the measuring range, measuring precision and resolution of this method are improved, and it basically has the conditions of application in the field of medium and low precision.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG82

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