长传动链摆头主轴高加速度启停控制策略研究

摆头主轴是高附加值关键功能部件，在航空结构件加工机床中大量采用。摆头主轴的传动链长，对伺服控制系统施加的高加速启停指令响应能力低，造成启停时间长，影响加工效率。在辨识某摆头主轴机械传动环节模态的基础上，建立了机械动力学模型和伺服控制模型，分析发现机械传动环节低频和高频模态限制伺服控制带宽的提高，进而限制了启停加速度的提高。针对低频和高频模态的限制，提出模态滤波器与双T网络陷波滤波器综合控制策略，将伺服控制带宽由12 Hz提高到110 Hz，启动加速度由10 r/s²提高到40 r/s²，启动加速时间由7.05 s下降至1.76 s。

Control Strategy of Long-chain Tilting Head Spindle for High-acceleration Starts and Stops

Tilting head spindles are long-chain mechanical spindles, which are widely used in machine tools for machining aviation parts. Due to the mechanical flexibility of the long transmission chain, the acceleration during starts and stops are usually low. Consequently, the productivity is seriously restricted because of the longtime of starts and stops. The dynamic model of mechanical transmission and its control block diagram are firstly established based on identifying the mechanical modes of a tilting head spindle. Secondly, the reasons for the limitation of the acceleration are analyzed. It is found that the control bandwidth of the tilting head spindle is restricted by the modes of the mechanical transmission, leading to the limitation of the acceleration. Finally, according to the modes of the mechanical transmission, the integrated control strategy combining the modal filter and the dual-T network notch filter are developed. The result show that the control bandwidth is improved significantly from 12 Hz to 110 Hz with the integrated control strategy. As a result, the acceleration is increased from 10 r/s² to 40 r/s², meanwhile the starting time is decreased from 7.05 s to 1.76 s.