基于IALA优化算法的机械臂自适应变阻抗恒力控制

Adaptive Variable Impedance Force Control for Manipulators Based on Improved Artificial Lemming Algorithm

  • 摘要: 针对不确定环境下机器人恒力控制存在的阻抗参数自适应能力弱、抗干扰性不足等问题,提出一种融合分数阶自抗扰控制(FOADRC)与径向基神经网络(RBFNN)的柔顺控制方法。首先,在位置控制内环设计FOADRC复合控制器,实时估计并补偿系统总扰动;其次,在外环构建基于RBFNN的自适应变阻抗模型,在神经网络隐含层嵌入卷积操作以加速特征提取,实现力/位误差到阻抗参数的非线性映射;再进一步通过改进人工旅鼠优化算法(IALA)对内外环中的控制器参数进行整定。仿真实验表明:所提方法能更好地实现期望力跟踪,减小了接触时力的超调量及力的波动。

     

    Abstract: To address the issues of weak adaptive capability of impedance parameters and insufficient anti-disturbance ability in robot constant force control under uncertain environments, we propose a compliant control method integrating fractional order active disturbance rejection control (FOADRC) and radial basis function neural network (RBFNN). Firstly, we design a FOADRC composite controller in the inner loop of position control to estimate and compensate the total system disturbance in real time. Secondly, we construct an adaptive variable impedance model based on RBFNN in the outer loop, where convolutional operations are embedded in the hidden layer of the neural network to accelerate feature extraction, realizing the nonlinear mapping from force/position errors to impedance parameters. Furthermore, we use the improved artificial lemming algorithm (IALA) to tune the controller parameters in both the inner and outer loops. Simulation experiments show that the proposed method can better achieve the desired force tracking, reduce the force overshoot and force fluctuations during contact.

     

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