控制-传感信号时滞补偿下柔性机械臂控制方法设计

Design of Control Method for Flexible Manipulator Under Control Sensor Signal Delay Compensation

相比于刚性机械臂,柔性机械臂因其结构及材料具有抗弯曲、刚度较低的特性,会产生信号延迟。目前,描述柔性机械臂控制大多基于时域信号分析建立,而时域分析模型忽略了控制与传感信号之间产生的不同高阶模态特征,导致二者存在时间滞后差。设计一种控制-传感信号时滞补偿下柔性机械臂控制方法。采用奇异谱分析对经过去噪处理的控制信号进行时频分解,以获得控制信号在时频域上的分布情况。使用Hilbert-Huang变换方法对传感信号进行频域变换,获取传感信号在频率空间上时间和幅值的变化规律。将控制-传感信号同步压缩后,生成替代数据边际谱,根据对边际谱生成信号的统计规律和非平稳数据辨别,完成控制-传感信号的延迟补偿,优化柔性机械臂的控制过程。实验结果表明:该方法的控制信号与传感信号延迟的很小,同时柔性机械臂的运动范围在正常范围之内。这些结果表明该方法具有良好的柔性机械臂控制效果。

Compared to rigid robotic arms,flexible robotic arms generate signal delays due to their structural and material characteristics of bending resistance and low stiffness.At present,the description of flexible robotic arm control is mostly based on time-domain signal analysis,which ignores the different high-order modal features generated between the control and sensing signals,resulting in a time lag difference between the two.In this work,a control method for flexible robotic arms with time-delay compensation of control sensing signals is designed.Singular spectrum analysis is used to perform time-frequency decomposition on the denoised control signal,in order to obtain the distribution of the control signal in the time-frequency domain.The Hilbert Huang transform method is used to perform frequency domain transformation on the sensing signal,and the temporal and amplitude changes of the sensing signal in the frequency space is obtained.After synchronously compressing the control sensing signal,a substitute data marginal spectrum is generated.Based on the statistics of the generated signal from the marginal spectrum and the identification of non-stationary data,the delay compensation of the control sensing signal is completed,and the control process of the flexible robotic arm is optimized.The experimental results show that the delay between the control signal and the sensing signal of this method is very small,and the motion range of the flexible robotic arm is within the normal range.These results indicate that the method has good control performance for flexible robotic arms.