A novel rigid–flexible combined sampler for lunar exploration

•The study of this paper is based on a 4-DOF sampler which consists of 3 rigid arms and 1 flexible arm.•The working principle and driving mechanism of the flexible arm is illustrated.•The kinematic control is modified due to the flexible factor.•Lab-based experiments verify the feasibility of the proposed sampler and some critical data are given.

Subsurface sampling systems for future lunar robotic missions, which include reliable methods of acquiring and delivering samples to scientific instruments or return capsules for further analysis, are of extreme significance to the success of future in-situ and sample return explorations. Thus, this paper presents a novel multi-DOF sampler, which is designed to perform subsurface regolith sampling for lunar or planetary subsurface exploration in the near future. The sampler is mainly composed of three rigid links and one flexible link. Compared to most of conventional samplers, the developed sampler has several significant merits, e.g. small shrinking volume, large working space and low power consumption. Considering the influence brought from flexible links, the modified kinematic control theory is analyzed and applied to the sampler. At last, the lab-based experiments show the effectiveness of the proposed mechanisms and the feasibility of the sampler.