Transmission error (TE) and backlash are important parameters used to evaluate the transmission accuracy of cycloid-pin drives. Existing calculation methods are mostly based on two-dimensional tooth profile models, and these methods ignore the influence of some abnormal meshing phenomena caused by profile modifications (PMs), manufacturing errors (MEs), and assembly errors (AEs), such as the instantaneous mesh-apart of tooth pairs and the eccentric load on the tooth surface. To fill this gap, a novel approach to accurately calculating the TE and backlash of a cycloid-pin gear pair based on the error tooth surfaces is proposed, and its feasibility and effectiveness are validated by comparison with the theoretical analyses and the results from the literature. Based on this, the effects of the PMs, MEs, and AEs on the transmission accuracy are studied, which will be helpful in optimizing the tooth profile design of a cycloid gear and the tolerance allocation during the installation of a gear pair. The proposed method is also expected to provide accurate error excitation data for the dynamic analysis of cycloid-pin drives.

As a core component of industrial robots, the transmission accuracy life (TAL) of rotary vector (RV) reducers constitutes a primary factor determining the high-precision operation of robotic systems. However, current life evaluation methods for RV reducers predominantly rely on conventional bearing strength life calculations, while neglecting its transmission accuracy degradation during operation. To address this limitation, a static analysis model of RV reducers is established, through which a calculation method for transmission accuracy and TAL is presented. Simultaneously, tooth surface and bearing wear models are developed based on Archard’s wear theory. Through coupled analysis of the aforementioned models, the transmission accuracy degradation law of RV reducers is revealed. The results show that during the operation of the RV reducer, the transmission error (TE) maintains relative stability over time, whereas the lost motion (LM) exhibits a continuous increase. Based on this observation, LM is defined as the evaluation metric for TAL, and a novel TAL estimation model is proposed. The feasibility of the developed TAL estimation model is ultimately validated through accelerated transmission accuracy degradation tests on RV reducers. The error between the predicted and experimental results is 11.06%. The proposed TAL estimation model refines the life evaluation methodology for RV reducers, establishing a solid foundation for real-time transmission accuracy compensation in reducer operation.

Deep-sea underwater connection and information interaction technology, including core technologies such as electromechanical hydraulic interface connection and underwater signal interactive transmission, is an effective technical means to solve the problem of information interaction and collaborative operation between underwater multi-platform and sensor nodes. With a large number of deep-sea vehicles in service in China, the energy, signal, data and other interfaces of the vehicles have not been unified, which leads to the difficulty in realizing multi-platform collaborative operations, so it is urgent to carry out corresponding research. In this paper, based on the analysis of the current situation of the information interaction technology of Jiaolong manned submersible, we carried out the research and summary of the multi-platform information technology of the deep-sea vehicle, and focused on the requirements of the exploration of the complex terrain and the detection of the morphology of accumulation body in the deep-sea hydrothermal region, proposed the design idea of the underwater multi-platform information interaction based on acoustic optic and electromagnetic transmission technology with Jiaolong manned submersible as the carrier, and completed the scheme design of the information interaction system of acoustic, optic and electromagnetic, which will provide technical support for the realization of the cooperative operation and high-efficiency application of the deep-sea vehicle cooperative operation.