Smart wearable robotic system, such as exoskeleton assist device and powered lower limb prostheses can rapidly and accurately realize man–machine interaction through locomotion mode recognition system. However, previous locomotion mode recognition studies usually adopted more sensors for higher accuracy and effective intelligent algorithms to recognize multiple locomotion modes simultaneously. To reduce the burden of sensors on users and recognize more locomotion modes, we design a novel decision tree structure (DTS) based on using an improved backpropagation neural network (IBPNN) as judgment nodes named IBPNN-DTS, after analyzing the experimental locomotion mode data using the original values with a 200-ms time window for a single inertial measurement unit to hierarchically identify nine common locomotion modes (level walking at three kinds of speeds, ramp ascent/descent, stair ascent/descent, Sit, and Stand). In addition, we reduce the number of parameters in the IBPNN for structure optimization and adopted the artificial bee colony (ABC) algorithm to perform global search for initial weight and threshold value to eliminate system uncertainty because randomly generated initial values tend to result in a failure to converge or falling into local optima. Experimental results demonstrate that recognition accuracy of the IBPNN-DTS with ABC optimization (ABC-IBPNN-DTS) was up to 96.71% (97.29% for the IBPNN-DTS). Compared to IBPNN-DTS without optimization, the number of parameters in ABC-IBPNN-DTS shrank by 66% with only a 0.58% reduction in accuracy while the classification model kept high robustness.

In this article, a new hydraulic semi-active knee (HSAK) prosthesis is proposed. Compared with knee prostheses driven by hydraulic-mechanical coupling or electromechanical systems, we novelly combine independent active and passive hydraulic subsystems to solve the incompatibility between low passive friction and high transmission ratio of current semi-active knees. The HSAK not only has the low friction to follow the intentions of users, but also performs adequate torque output. Moreover, the rotary damping valve is meticulously designed to effectively control motion damping. The experimental results demonstrate the HSAK combines the advantages of both passive and active prostheses, including the flexibility of passive prostheses, as well as the stability and the sufficient active torque of active prostheses. The maximum flexion angle in level walking is about 60°, and the peak output torque in stair ascent is greater than 60Nm. Relative to the daily use of prosthetics, the HSAK improves gait symmetry on the affected side and contributes to the amputees better maintain daily activities.

This paper mainly focuses on the dispatching problem of trains in case of segment blockage caused by emergency in the daily operation of high-speed railway. We further incorporate the speed adjustment by considering the additional safety constraints caused by changing speeds, then construct a mixed integer nonlinear programming model with optimized speed. The model can be directly solved by using commercial optimization software CPLEX. Finally, we set the segment blockage on the Hefei-Shanghai high-speed railway in the simulation, the simulation verifies the effectiveness and rationality of our model.