Impact-aware task-space quadratic-programming control
Impact-aware task-space quadratic-programming control
复制标题
影响感知任务空间二次规划控制
DOI：
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
A. Kheddar
中科院分区：
文献类型：
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作者：
Yuquan Wang;Niels Dehio;Arnaud Tanguy;A. Kheddar
机器人通常以接近零的相对速度在刚性表面上建立接触。否则，冲击引起的能量在机器人的连杆中传播，并可能对硬件造成不可逆的损坏。此外，任务空间接触速度和峰值冲击力的突然变化也会导致机器人关节速度和扭矩的突然变化;这会损害控制器的稳定性，特别是对于那些基于平滑模型的控制器。实际上，有几项任务需要以适度的高速建立联系。我们建议增强任务空间的多目标控制器制定为一个二次规划是弹性的摩擦影响在三个维度。我们设计了新的约束条件，并重新制定了通常的是强大的突然联合状态变化前面提到的。一旦最优控制搜索空间意识到：（1）硬件可承受的撞击边界和（2）约束撞击后临界状态的分析计算的可行集（多面体），撞击事件就成为受控过程。在目标接触点之前和附近，我们假设，在每个控制周期，影响将发生在下一次迭代。这种一步预览使我们的控制器对影响时间和位置具有鲁棒性。为了评估我们的方法，我们用熊猫机械手实验了它对中等冲击的弹性，并用HRP-4人形机器人实现了快速抓取任务。
Robots usually establish contacts at rigid surfaces with near-zero relative velocities. Otherwise, impact-induced energy propagates in the robot’s linkage and may cause irreversible damage to the hardware. Moreover, abrupt changes in task-space contact velocity and peak impact forces also result in abrupt changes in robot joint velocities and torques; which can compromise controllers’ stability, especially for those based on smooth models. In reality, several tasks would require establishing contact with moderately high velocity. We propose to enhance task-space multi-objective controllers formulated as a quadratic program to be resilient to frictional impacts in three dimensions. We devise new constraints and reformulate the usual ones to be robust to the abrupt joint state changes mentioned earlier. The impact event becomes a controlled process once the optimal control search space is aware of: (1) the hardware-affordable impact bounds and (2) analytically computed feasible set (polyhedra) that constrain post-impact critical states. Prior to and nearby the targeted contact spot, we assume, at each control cycle, that the impact will occur at the next iteration. This somewhat one-step preview makes our controller robust to impact time and location. To assess our approach, we experimented its resilience to moderate impacts with the Panda manipulator and achieved swift grabbing tasks with the HRP-4 humanoid robot.
影响因子：
9.2
作者：
Manchester, Zachary;Doshi, Neel;Kuindersma, Scott
通讯作者：
Kuindersma, Scott