Multi-mechanism Cooperative Motion Planning In Variable Cross-section Roll Forming

The variable cross-section roll bending process is a new manufacturing mode with coordinated operation of multiple mechanisms.This paper focuses on the multi-mechanism kinematics coordinated operation planning theory in variable-section roll-bending forming equipment,and conducts a systematic study on multi-mechanism cooperative planning,kinematic calibration,cooperative kinematics and roll-slip control for variable-section roll-bending forming equipment.The main research contents are as follows:(1)Based on the kinematics equation,the basic coordinate system of all passes was kinematically calibrated.On the basis of the preliminary calibration,the quaternion constraints were used to orthogonalize the preliminary calibration,and the forming equipment was proposed.The multi-pass precise calibration method obtains a unified pose description of all roll arms in the world coordinate system.(2)A multi-mechanism coordinated motion planning method for variable-section roll bending equipment is proposed.According to different work tasks,the operation process is planned into three modes: independent operation mode,partial cooperative operation mode and cooperative operation mode.Under the three different modes,the motion constraint relationships between the roll arms and between the roll arms and the workpiece establish a universal multi-mechanism cooperative motion constraint relationship expression,which provides a theoretical basis for subsequent cooperative motion planning.(3)Aiming at the problem of cooperative motion planning of multiple mechanisms,trajectory planning is performed for single-pass roll arms and multiple-pass roll arms respectively,and the geometric characteristics of roll paths(position,Tangent vector,curvature)and the machine tool kinematics(feed speed,acceleration)and the functional relationship between.At the same time,through the cooperative movement between passes,the error caused by the slip of the plate is eliminated,and the contour accuracy of the processed workpiece is ensured.