Drilling a hole on a curved surface with a desired angle is prone to failure when done manually, due to the difficulties in drill alignment and also inherent instabilities of the task, potentially causing injury and fatigue to the workers. On the other hand, it can be impractical to fully automate such a task in real manufacturing environments because the parts arriving at an assembly line can have various complex shapes where drill point locations are not easily accessible, making automated path planning difficult. In this work, an adaptive admittance controller with 6 degrees of freedom is developed and deployed on a KUKA LBR iiwa 7 cobot such that the operator is able to manipulate a drill mounted on the robot with one hand comfortably and open holes on a curved surface with haptic guidance of the cobot and visual guidance provided through an AR interface. Real-time adaptation of the admittance damping provides more transparency when driving the robot in free space while ensuring stability during drilling. After the user brings the drill sufficiently close to the drill target and roughly aligns to the desired drilling angle, the haptic guidance module fine tunes the alignment first and then constrains the user movement to the drilling axis only, after which the operator simply pushes the drill into the workpiece with minimal effort. Two sets of experiments were conducted to investigate the potential benefits of the haptic guidance module quantitatively (Experiment I) and also the practical value of the proposed pHRI system for real manufacturing settings based on the subjective opinion of the participants (Experiment II).
翻译:以理想角度在弯曲表面钻洞,如果手工操作,容易发生故障,因为钻孔调整困难,而且任务固有的不稳定性,可能会对工人造成伤害和疲劳。另一方面,在实际制造环境中完全自动化这种任务可能是不切实际的,因为到达组装线的部件可能具有各种复杂的形状,钻点位置不易进入,使自动路径规划困难。在这项工作中,开发了一个具有6度自由的适应性接纳控制器,并将其安装在KUKA LBRIiwa 7 cobot上,使操作员能够操作在机器人上安装的钻头,用一只手舒适和开的洞在曲线表面操作,给工人造成伤害和疲劳。另一方面,在通过AR接口提供的对cobot 和视觉指导完全自动自动自动自动自动自动化,使机器人在自由空间驾驶机器人时更加透明,同时确保钻孔期间的稳定。在用户将钻孔的钻孔足够接近钻孔目标,并大致与理想的钻孔角度相匹配之后,机制制制导模制模块调整了第一个方向的精确调整系统,然后将精度限制在一个弯式的钻机操作器的深度上进行钻动。