Compliance is good. However, it is challenging for one compliant continuum robot to finish both high precision manipulation and environmental-adapted motions. In this paper, a modular continuum robot with the alterable compliance characteristic is proposed. Besides, an actuation module is also proposed using a tubular-screw mechanism for non-slippage transmission. Kinematic analyses and dynamic co-simulation are performed to study the continuum robot. Furthermore, two potential application scenarios of pick-and-place manipulation and confined space navigating are carried out to demonstrate the advantages of the alterable compliance design. This study presents a capable continuum robotic solution for non-structural inspection tasks, with potential for in-situ applications in restricted and hazardous environments.

Regular maintenance of pipelines is an important task to ensure oil transportation and other operation (sewers, nature gas). Precise localization of pipeline damage can greatly improve the efficiency of maintenance work. Since the texture similarity and illumination change of pipe, traditional local descriptors for image matching like SIFT, SURF and ORB are easy to suffer from false correspondences. As to remove the false matches, the local neighborhood constraints (LNC) that contain spatial constructs around feature points are proposed. Good correspondences are essential for the high-accuracy localization and mapping solution given the limited textures and illumination in the pipes. The LNC method is also integrated into the state-of-the-art visual SLAM system. The proposed LNC image matching method and the SLAM system are evaluated on datasets gathered from the pipe environment. Compared with other state-of-the-art methods, our LNC image matching method achieves similar or better performance in precision, recall and runtime. The SLAM system provides state estimation and map reconstruction of the pipe in real-time, and the localization error is within 1%.

To cope with the requirements on efficiency and labour-saving of the out-pipe surface grinding tasks in the wild, several proposals are revealed and discussed. The one benefiting from the characteristics of planetary gear transmission and friction actuating mechanism are expatiated. To realize full coverage of out-pipe surface, the self-rotation and revolution motions of every polishing tool (cutter) are actuated by the same motor, and the friction force produced in grinding process acts as suitable tractive force for the forward travel of the grinding system. The friction statics analysis is established to illustrate the force transmission. Compression spring system are utilized to realize force equilibrium and support passive diameter adaptability. The proposed robotic grinding system is characterized by less actuator, online grinding capability and high working efficiency. It has clear advantages regarding manufacturing costs and control complexity. As the result of prototype experiments, performance of smooth grinding the out-pipe surface is confirmed.