面向医疗机器人机械臂的自适应LSTM参数标定方法

      Nonlinear Parameters Calibration of Medical Robots Based on Adaptive Long Short-Term Memory Neural Network

      • 摘要: 医疗机器人在标定过程中存在多源、非线性误差,使得传统数学建模方法难以全面刻画其系统误差特性,从而限制了标定精度的进一步提升。该文建立了机器人参数误差辨识模型,并提出一种基于自适应长短时记忆(ALSTM)神经网络的标定方法。该方法引入粒子群优化算法(PSO)对LSTM神经网络的各层权重进行优化,以更有效地拟合机器人运动学误差,进而获得更为准确的D-H参数。在HSR-JR680机器人标定系统中采集110组实验数据进行验证。实验结果表明,ALSTM模型在均方根误差(RMSE)方面较传统标定方法降低了23.07%~80.39%,收敛时间较普通LSTM模型减少了32.44%,所获得的最优D-H参数符合医疗机器人对高精度标定的需求,验证了该方法的有效性。

         

        Abstract: Medical robots often encounter multi-source and nonlinear errors during the calibration process, making it difficult for traditional mathematical modeling methods to fully characterize system error features, thereby limiting further improvement in calibration accuracy. In this study, a robot parameter error identification model is established, and a calibration method based on an adaptive long short-term memory (ALSTM) neural network is proposed. The method incorporates a particle swarm optimization (PSO) algorithm to optimize the weights of each layer of the LSTM neural network, enabling more effective fitting of kinematic errors and ultimately yielding more accurate Denavit–Hartenberg (D-H) parameters. To validate the proposed approach, 110 sets of experimental data are collected using the HSR-JR680 robot calibration system. Experimental results demonstrate that the ALSTM model reduces the root mean square error (RMSE) by 23.07%~80.39% compared to traditional calibration methods, and shortens the convergence time by 32.44% compared to a standard LSTM model. The optimized D-H parameters obtained meet the high-precision calibration requirements of medical robots, confirming the effectiveness of the proposed method.

         

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