林用起重机起吊木捆偏摆系统的动力学模型与仿真

摘要

A study was conducted to establish a dynamic model of log bundle deflection system for gantry crane in forestry. Relationships between swing angle of log bundle in the vertical direction and trolley' s acceleration, rope length and lifting speed of log bundle are obtained by linear simplification, while the horizontal swing angle is related with the torsion coefficient of wire rope and its inertia. Load shimmy differential equations of uniform descent of log bundle after the trolley brake are set up. Moreover, vibration differential equations are simulated by Simulink. Results show that rope length, rate of decline and material length have major impacts on the lifting log bundle deflection system. The simulation results further improve the previous achievements in theoretical research, which make the model more consistent with the actual system by considering the system damping%建立了林用起重机木捆偏摆系统的动力学模型,并经过线性简化得出木捆在垂直方向的摆角主要与其同向的小车加(减)速度和绳长,以及木捆升降速度有关,而水平摆角与自身的转动惯量和钢丝绳的扭转系数有关.建立了小车制动后木捆匀速下降过程的二自由度木捆摆振微分方程,最后采用Simulink对振动微分方程进行仿真,结果表明绳索长度、木捆下降速度以及木捆材长对木捆偏摆系统动力响应有重要影响.所得仿真结果进一步完善了先前理论分析研究成果,理论上考虑了系统阻尼,从而使模型更加与实际系统一致.