基于运动预测和阻抗控制的未知受限机构操作

Operating Unknown Constrained Mechanisms Based on Motion Prediction and Impedance Control

针对服务机械臂操作各种未知受限运动机构的需要,提出了一种基于运动预测和阻抗控制的控制方法,本方法采用试探-预测-修正的滚动操作策略,通过阻抗控制保证机械臂与未知受限机构交互的柔性.首先试探受限机构的运动能力,根据已有操作臂运动轨迹估计受限机构的运动模型,然后预测受限机构的运动方向,进而修正机械臂的运动轨迹,并根据交互作用强度动态调节运动速率.基于上述连续滚动调节,提高了机械臂对未知受限机构探作的安全性和效率.配置6维腕力/力矩传感器的6自由度辅助机械臂的开门实验,证明了所提方法的有效性.

In order to meet the needs for assistive robot manipulators in operating various constrained mechanisms,a control method based on motion prediction and impedance control is proposed.A rolling manipulation strategy of exploration-prediction -adjustment is employed,through impedance control to provide compliant interaction between the assistive manipulator and unknown constrained mechanisms.Firstly,the motion capability of the constrained mechanism is explored to build its motion model according to the passed motion trajectory of the manipulator.Then,motion direction of the mechanism is predicted based on the motion model.Finally,the trajectory of manipulator is adjusted in alignment with the predicted direction, while the magnitude of the velocity is dynamically adjusted according to the interaction force.Based on this continuous rolling adjustment,safety and efficiency of a manipulator for operating unknown constrained mechanisms are enhanced.Experiments of autonomous door opening utilizing a 6DoF assistive manipulator with a six-dimensional force/torque sensor demonstrate the validity of the proposed method.