The utility of tactile force to autonomous learning of in-hand manipulation is task-dependent
The utility of tactile force to autonomous learning of in-hand manipulation is task-dependent
复制标题
触觉力对自主学习手动操作的效用取决于任务
DOI：
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
F. Cuevas
中科院分区：
文献类型：
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作者：
Romina Mir;Ali Marjaninejad;F. Cuevas
触觉传感器提供可用于学习和执行操纵任务的信息。然而，不同的任务可能需要不同水平的感官信息，这反过来又可能影响学习速度和表现。本文评估了触觉信息的作用，自主学习的操作与模拟3指肌腱驱动的手。我们比较了相同的学习算法（近端策略优化，PPO）学习两个操作任务（在有和没有旋转刚度的情况下绕水平轴滚动球）的能力，以及三个级别的触觉传感：无感测，1D法向力和3D力矢量。令人惊讶的是，与最近的操纵工作相反，与没有感知相比，添加1D力感知并不总是提高学习率-可能是由于正常力是否与任务相关。尽管如此，尽管3D力感测增加了感觉输入的维度--这通常会阻碍算法收敛--但它会导致更快的学习速度和更好的性能。我们的结论是，在一般情况下，感官输入是有用的学习，只有当它是相关的任务-是3D力感测的情况下，手操纵重力。此外，3D力感测的效用甚至可以抵消使用更高维的感觉输入学习所增加的计算成本。
Tactile sensors provide information that can be used to learn and execute manipulation tasks. Different tasks, however, might require different levels of sensory information; which in turn likely affect learning rates and performance. This paper evaluates the role of tactile information on autonomous learning of manipulation with a simulated 3-finger tendon-driven hand. We compare the ability of the same learning algorithm (Proximal Policy Optimization, PPO) to learn two manipulation tasks (rolling a ball about the horizontal axis with and without rotational stiffness) with three levels of tactile sensing: no sensing, 1D normal force, and 3D force vector. Surprisingly, and contrary to recent work on manipulation, adding 1D force-sensing did not always improve learning rates compared to no sensing---likely due to whether or not normal force is relevant to the task. Nonetheless, even though 3D force-sensing increases the dimensionality of the sensory input---which would in general hamper algorithm convergence---it resulted in faster learning rates and better performance. We conclude that, in general, sensory input is useful to learning only when it is relevant to the task---as is the case of 3D force-sensing for in-hand manipulation against gravity. Moreover, the utility of 3D force-sensing can even offset the added computational cost of learning with higher-dimensional sensory input.