Measurement of the kinematic parameters of payload swing using projective correction
Accurate measurement of the kinematic parameters of payload swing is crucial for lifting and transporting dissipative swing control. However,the existing single-image projective correction methods are susceptible to the interference of background and other factors. It is difficult to automatically extract the coplanar straight-line constraints,thus restricting the measurement accuracy. To address this problem,a projective rectification method is proposed that utilizes dynamic line constraints from temporal image sequences. Firstly,dynamic straight lines are extracted from specific temporal images through the integration of background differencing and color thresholding methods. Subsequently,clustering is performed using an improved random sample consensus algorithm,thereby establishing reliable constraint conditions. Secondly,the Levenberg-Marquardt iterative method is used to estimate the vanishing point and the absolute quadratic curve based on the linear constraints. Then,the correction matrix was calculated. Thirdly,the coordinates of the marker points are rectified,which are employed to calculate the swing angle and trolley speed. In the measurement of kinematic parameters of the payload swing,the aforementioned method achieves a root mean square error of 0.1247° in comparison with angle measurement by the inertial measurement unit,and a root mean square error of 0.0036 m/s in comparison with the set trolley speed. Compared with the inverse perspective correction method,the projective correction method with coplanar linear constraints and non-coplanar linear constraints,the angular accuracy is improved by 69.05％,76.35％,and 93.91％,and the velocity accuracy is improved by 42.85％,47.06％,and 59.55％,respectively. The proposed method utilizes the swing string in the payload swing as constraint for projective rectification,aiming to obtain richer and more precise constraint conditions,thereby enabling superior measurement precision of kinematic parameters in the payload swing.
万方数据
维普
