Excavators are crucial heavy equipment on construction sites, performing diverse earthwork tasks. The construction worksite is experiencing a labor shortage due to an aging workforce. Training new operators requires significant time and resources. Furthermore, the construction environment is hazardous, with a higher rate of excavator-related accidents. Autonomous excavators offer an effective solution by reducing the need for operators in risky environments and substituting skilled workers. Trajectory planning algorithms are vital for autonomous excavators, with skilled operators’ paths serving as important references. However, many studies do not adequately consider skilled operators’ methods or the actual excavation environment. This paper introduced a rule-based algorithm for excavation trajectory planning using terrain data. Based on analysis results of skilled operators’ paths, the proposed algorithm categorizes the excavation process into three stages, depending on the usage rate of the excavator"s joints. Terrain data were derived by projecting point clouds from a stereo depth camera onto a side plane. The path was modified if the excavation volume exceeded a set limit to avoid excessive load. The algorithm was tested with a 30-ton excavator, demonstrating validation of operability and efficiency similar to that of skilled operators.

To schedule a Reconfigurable Manufacturing Cell (RMC), reconfiguration and setting decisions should be made first. Those decisions, together with characteristics of production orders, affect attainable performance of a system. So an integrative approach is required considering all decisions and characteristics rather than dealing with each of them separately. Pallet-fixture allocation, as a decision problem in setting, which determines the number of pallets to be equipped with each fixture type to produce different types of products, has rarely been investigated. In this study, several pallet-fixture allocation rules are proposed including both simple and novel ones. Then system performance is investigated through various combinations of setting and scheduling decisions (rules) for given system configurations and production orders, via simulation. The result shows that one of proposed pallet-fixture allocation rules which considers both configuration and order characteristic outperforms the others, justifying the necessity of an integrative approach in the RMC operation