A robust and compliant robotic assembly control strategy for batch precision assembly task with uncertain fit types and fit amounts

In some high -precision industrial applications, robots are deployed to perform precision assembly tasks on mass batches of manufactured pegs and holes. If the peg and hole are designed with transition fit, machining errors may lead to either a clearance or an interference fit for a specific pair of components, with uncertain fit amounts. This paper focuses on the robotic batch precision assembly task involving components with uncertain fit types and fit amounts, and proposes an efficient methodology to construct the robust and compliant assembly control strategy. Specifically, t he batch precision assembly task is decomposed into multiple deterministic subtasks, and a force -vision fusion controller -driven reinforcement learnin g method and a m ulti-task reinforcement learning training method (FVFC -MTRL) are proposed to jointly learn multiple compliance control strategies for these subtasks. Subsequently, the multi-teacher policy distillation approach is designed to integrate multiple trained strategies into a unified student network, thereby establishing a robust control strategy. Real -world experiment s demonstrate that the proposed method successfully constructs the robust control strategy for high -precision assembly task with different fit types and fit amounts. With the development of intelligent manufacturing, deploying robots to replace manual operations in peg -in-hole assembly tasks has greatly enhanced production efficiency and product quality [1]. In the batch assembly process of 3C (computers, communication and consumer electronics) products, h igh-precision assembly tasks are more challenging as the mating components to be assembled are in tight clearance fits (0.01 mm) or even small interference fit s [2 ]. In high-precision industrial scenarios, the fit types of numerous mating components are designed as transition fits, such as mobile phone lenses. To enhance assembly efficiency, the geometric dimensions of the mating components are typically not individually measured prior to the assembly.