With the wide application of lower limb exoskeleton robots in various fields, problems such as individual motion feature recognition have gradually come to the fore. Therefore, this paper carries out a study on motion pose acquisition and action recognition based on IMU sensors. By using a motion capture system to analyze the motion movements of the human lower limbs and establishing a human lower limb motion dataset, the motion laws of the lower limb joints were extracted. We also used IMU sensors for real-time motion data acquisition. The data obtained from the two acquisition methods were compared to ensure the reliability of the IMU sensor data acquisition. To improve the accuracy of data acquisition, the IMU sensor data were processed using Kalman filtering. Based on the DTW algorithm, we carry out simulation experiments to analyze the motion data collected by IMU in real-time compared with the motion dataset, to achieve the real-time recognition of human motion movements. This research can solve the problem of individual motion feature recognition in the application of lower limb exoskeleton robots and provide strong support for research and application in rehabilitation and assisted walking.

A new type of FT pin-cycloid transmission reducer is widely used in the industrial robot field due to the high transmission accuracy. In addition, the complex working conditions bring about vibration, which affects the transmission accuracy of the robot. Therefore, it is necessary to study the dynamic characteristics of FT reducer at the transmission joint. In this paper, based on the analysis of its transmission principle and structure, the dynamic model of FT transmission is established by necessary assumptions. The stiffness mathematical models of different meshing positions are obtained from the dynamic model, and the differential equations of the system are established by Lagrange method. In order to solve the natural frequency of the system, the stiffness of meshing positions of the system is solved, including input shaft torsional stiffness, involute gear meshing stiffness, bearing stiffness, cycloid gear and pin torsional stiffness. Considering the output of FT transmission, a “3+i” model is proposed to obtain the mesh stiffness between the cycloid gear and output pins. Finally, the correctness of the model is proved by choosing parameters such as transmission ratio and force on parts and components by simulation. The research results will provide theoretical support for the optimal design of FT transmission.

This study presents an optimal control strategy for connected and automated vehicles (CAVs) at unsignalized intersections. A control framework with task-decomposition is designed for the near-intersection area. Firstly, the continuous traffic flow is discretized with a proposed intersection area-division scheme. Then, vehicles in different lanes are regrouped based on longitudinal positions to establish multivehicle cooperative optimal control problems of limited vehicle number. The expected optimal trajectory in the merging zone is obtained through offline simulation, which simplifies the constraints of the optimal control problem and improves the real-time performance of the online trajectory solving. Finally, an ideal capacity model is proposed based on the transit time window of vehicle, so that the capacity of a single lane is increased to 2400veh/h. The simulation results demonstrate that the proposed strategy ensures the driving safety at the unsignalized intersection, and this strategy efficiently reduces planning time for vehicle trajectories.