Characterising the mechanics of rectangular peg-hole disassembly and the effect of the position of the active compliance centre on the extraction force

This paper reports work aimed at facilitating robotised disassembly which is the first step in product remanufacturing. Focusing on the specific task of rectangular peg-hole disassembly, our research aims to contribute to the development of a specialised robotic system for this purpose. The primary objective is to identify and characterise the common disassembly states during the extraction of a rectangular peg from a rectangular hole.The paper explores all potential contact states during the rectangular peg-hole disassembly process and identifies 26 distinct conditions, 16 of which are related to jamming. The contact conditions are categorised into five groups: 1) two-point contact, 2) two-sided contact, 3) combined two-sided and one-plane contact, 4) two-edge contact, and 5) three-edge contact. This paper also provides an in-depth analysis of jamming phenomena during the extraction process, employing both geometrical and quasistatic analyses to establish boundary conditions for jamming. Furthermore, the study explores the efficacy of an active compliance centre position as a strategic solution to prevent jamming. Critical variables are simulated, and key parameters—including the degree of compliance, compliance centre location, and initial position errors—are examined to ascertain their impact on the disassembly process.The outcomes highlight that positioning the compliance centre at the peg’s end is the most effective strategy for further minimising the jamming area and decreasing the required extraction force. Finally, the simulated results are confirmed by experiments.The findings contribute insights into the intricate dynamics of disassembly, revealing potential avenues for optimising automated robotic systems in remanufacturing applications.