An underactuated self-reconfigurable robot and the reconfiguration evolution

•The architecture has the minimum number of fundamental modules, and they can form passive joints and adjustable links, which increases the overall resource utilization.•The reconfiguration and locomotion share the same motor, which reduces the complexity of module design and reduces the energy consumption.•A two-phase self-reconfiguration, reconfiguration planning and reconfiguration scheduling was proposed to achieve the goal configuration from a damaged configuration, which reduces the search time.