Contact can be conceptualized as a set of constraints imposed on two bodies that are interacting with one another in some way. The nature of a contact, whether a point, line, or surface, dictates how these bodies are able to move with respect to one another given a force, and a set of contacts can provide either partial or full constraint on a body's motion. Decades of work have explored how to explicitly estimate the location of a contact and its dynamics, e.g., frictional properties, but investigated methods have been computationally expensive and there often exists significant uncertainty in the final calculation. This has affected further advancements in contact-rich tasks that are seemingly simple to humans, such as generalized peg-in-hole insertions. In this work, instead of explicitly estimating the individual contact dynamics between an object and its hole, we approach this problem by investigating compliance-enabled contact formations. More formally, contact formations are defined according to the constraints imposed on an object's available degrees-of-freedom. Rather than estimating individual contact positions, we abstract out this calculation to an implicit representation, allowing the robot to either acquire, maintain, or release constraints on the object during the insertion process, by monitoring forces enacted on the end effector through time. Using a compliant robot, our method is desirable in that we are able to complete industry-relevant insertion tasks of tolerances <0.25mm without prior knowledge of the exact hole location or its orientation. We showcase our method on more generalized insertion tasks, such as commercially available non-cylindrical objects and open world plug tasks.
翻译:接触可以被概念化为对两个以某种方式相互互动的机构施加的一系列限制。接触的性质,无论是一个点、线或表面,决定着这些机构如何能够相互移动,而一组接触可以提供部分或完全限制一个机构的运动。 几十年的工作探索了如何明确估计接触的地点及其动态,例如摩擦性质,但所调查的方法是计算成本高昂的,最后计算时往往存在很大的不确定性。这影响到接触程度高、对人来说似乎简单易懂的接触目标的进一步进展,例如普遍的嵌入洞插入。在这项工作中,我们不是明确估计一个目标及其洞之间的个别接触动态,而是提供部分或全部限制。 十年的工作探索了如何明确估计接触地点及其动态,例如摩擦性质,但调查的方法是计算成本昂贵的,在最后计算中往往存在很大的不确定性。 这使得机器人能够获取、保持或释放对一个目标的直径直的插入点的自我定位。 在插入过程中,我们通过一种正确的方法,通过一种正确的方式,我们通过一种正确的方式,对一个稳定的插入方式,对一个稳定的插入方式进行我们的工具进行控制。</s>