In the pipeline industry, it is often necessary to monitor cracks and damage in pipelines, or need to clean the inside of the pipeline regularly, or collect adhesive on the inner wall of the pipe, but the pipe is too narrow and difficult for humans to enter, it is necessary to use a pipe machine to complete the work. In this paper, a newly designed screw-driven in-pipe inspection robot (IPIR) is proposed. Compared with common robots, this robot innovatively designs adapting mechanism. The robot can not only adapt to the change of the inner diameter size of the pipeline by using the bionic principle and the deformation characteristics of flexible components but also can pass smoothly in the horizontal/oblique/vertical pipelines and has a certain ability to cross obstacles. In addition, it can transmit images of the inner wall of the pipeline wirelessly for data analysis. Finally, through theoretical analysis and prototype construction, the performance of the robot is verified. The results show that the prototype robot can not only smoothly pass through the acrylic pipe with inner diameter of 120–138 mm but also pass through boss with a height of 3 mm.

The frog-inspired robots with amphibious locomotion ability have greatest application prospects and practical value in the fields of resource exploration and environmental reconnaissance. Although frog-inspired robots have been of interest over many years, research on frog-inspired amphibious robots is still in its infancy. Since the locomotion mechanism is the basis for the research of frog-inspired amphibious robots, the research methods of the single motion mechanism of frogs are firstly inductive analyzed, and a reference scheme is proposed to inspire the research on the amphibious motion mechanism. Then, we collect and introduce a systematic discussion of the research status of frog-inspired robots according to the locomotion mode. The characteristics of the robots are analyzed from the aspects of design concept, structural characteristics, driving method, and motion performance. Finally, the technical challenges faced by the research on the frog-inspired robots are analyzed, and the development trend is predicted. The authors hope that this study can provide an informative reference for future research in the direction of frog-inspired amphibious robot.

A novel approach to control synthesis of biped locomotion mechanisms is suggested. The synthesis is carried out in two stages: the stage of nominal regimes (the synthesized control has to ensure the realization of gait in the absence of any disturbance), and the stage of perturbed regimes (the control has to eliminate deviations from the nominals under an additional condition of preserving the stability of the overall System). At the level of perturbed regimes, the proposed control synthesis should ensure the compensating movements such to bring the System ot its nominal during the gait. However, the compensating movements can, as a side–effect, induce the undesirable inertial forces which can influence the mechanism overall stability. To avoid this, it is suggested such a control which ensures that the acceleration of compensating movements does not exceed a value given in advance. In addition, the case is considered when an additional correction of the zero moment point ZMP position is accomplished by different mechanism joints.