This paper proposes a stiff and safe task-space position and attitude control scheme for robotic manipulators. This study extends the work of Kikuuwe et al’s. (2006) velocity-bounding proxy-based sliding mode control by explicitly addressing the attitude part. The proposed controller has a Jacobian-based structure, which realizes smooth trajectories when the desired attitude is far rotated from the actual attitude. It also imposes arbitrary magnitude limits on the end-effector velocity, angular velocity, and each actuator force without sacrificing a stiffness, which is the same level as a high-gain PID position control below the limits. The benefit of the proposed controller becomes apparent after the robot yields to external forces due to force saturations, when the robot makes contact with obstacles. In such a situation, if the external forces disappear, the controller generates overdamped resuming motion from large tracking errors. The proposed controller can be expected to enhance the safety of robotic applications for the human–robot interaction. The proposed method is validated by experiments employing a six-degree of freedom industrial manipulator.

中文翻译：

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机器人操纵器的刚性且安全的任务空间位置和姿态控制器

本文提出了一种僵化，安全的机器人空间任务空间位置和姿态控制方案。这项研究扩展了Kikuuwe等人的工作。（2006年）通过明确解决姿态部分基于速度限制代理的滑模控制。所提出的控制器具有基于雅可比关系的结构，当所需姿态与实际姿态相差很远时，该结构可实现平滑的轨迹。它还在不牺牲刚度的情况下对端部执行器速度，角速度和每个执行器力施加了任意大小限制，该刚度与低于该限制的高增益PID位置控制相同。当机器人与障碍物接触时，由于力饱和而使机器人屈服于外力后，所提出的控制器的优势变得显而易见。在这种情况下 如果外力消失，则控制器会因较大的跟踪误差而产生过阻尼的恢复运动。预期所提出的控制器可以提高人机交互中机器人应用程序的安全性。通过使用六自由度工业机械手的实验验证了所提出的方法。