在未知环境下面向位控机器人的力/位混合控制

Hybrid force/position control for positional-controlled robotic manipulators in unknown environment

提出了一种面向位控机器人的力/位混合控制策略.通过力反馈信息对未知环境约束进行估计获得位控和力控方向,根据位控和力控方向对机器人终端的运动轨迹进行规划,并采用阻抗控制规律以使机器人获得较好的柔顺性.在该算法中应用一个参考比例因子调节参考轨迹,根据反馈的接触力信息通过模糊推理确定参考比例因子的大小,从而使生成的参考轨迹适应未知环境刚度的变化.仿真试验表明,该策略具有较高的力控制精度和表面跟踪能力,增强了对接触环境参数变化的鲁棒性.

Presented a hybrid force/position control strategy for position-controlled robotic manipulator. On-line force feedback data was employed to estimate the local shape of constraint. The estimated vectors were used to generate the virtual reference trajectory for the target impedance model, which was driven by the force error to produce a command position to the manipulator. By following the commanded position trajectory the robotic manipulator can follow unknown constraint surface while keeping an acceptable force error in a manner depicted by the target impedance model. A reference scaling factor was thus developed to tune the reference trajectory in order to adapt the reference trajectory generated for the changeable unknown stiffness in environment. The reference scaling factor was determined by fuzzy reasoning in accordance to the information feedback on forces in contact. Computer simulation was conducted to verify its force tracking capability.