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In order to reduce the energy consumption of pure electric vehicles in actual driving, the gear shift law of the two-speed mechanical automatic transmission is optimized. According to the actual needs of urban, suburban and comprehensive driving cycle in Taiyuan city, the driving motors of the vehicles are matched, and the traditional economic shifting rules are formulated based on the motor efficiency. Then, the optimal gear shifting points under different driving cycle in Taiyuan city are solved by dynamic programming, and the optimal two-parameter shift schedule is discovered. Through Matlab/Simulink modeling and simulation, the energy consumption of the two shifting laws under different Driving cycle is compared. The results show that compared with the traditional economic shift law, the optimized two-parameter shift law can better reduce vehicle energy consumption and improve the endurance mileage.

This paper presents a preview control algorithm (PCA) for hybrid machine tool based on kinematics calculation. HMT (Hybrid Machine Tool) combines the flexibility of parallel structure with the extensibility of series structures. The kinematics are calculated and analyzed as well as the calculation process. Due to the complexity of its structure and kinematics algorithms, a motor PCA is proposed in the situation of calculation failure and used to reduce the corresponding motor vibration. The experimental results shows that the PCA is an effective way to detect and suppress the motor vibration and shock during the motion control of PRS-XY HMT.

In order to solve problem of limited working travel of coal mine detection robot, a coal mine detection robot was designed, which can independently increase its communication distance and automatically return. When wireless control signal is weakened, the robot will use repeater catapulting system to increase wireless communication distance. When wireless signal is suddenly interrupted, the robot will initiate automatic returning function, and return to a safe place automatically according to sensor data memorized in the scouting process. Automatic returning function of robot adopts integration data method between encoders and laser sensor, uses ICP algorithm to do double data matching and adjust position and orientation gradually of the robot, so as to realize high accuracy in the process of automatic returning. Testing results show that the robot has a long working travel distance and automatic returning function, can work stably and safely at the scene of unknown coal mine disaster, and can replace rescue workers to complete early dangerous detection work in coal mine, provide a significant on-site data information for coal mine rescue.

A mathematical model of the joint clearances and the kinematic model of the double push rod manipulators with joint clearances were established. The influences of the position and number of three different joint clearances including single joint clearance A, single joint clearance B, double joint clearance A and B on the trajectory, velocity and acceleration of the ends of the manipulators were analyzed by using simulation, and the absolute errors were used as the evaluation index to quantitatively analyze the influence degree. An experimental platform was built to verify the simulation results. The results show that, joint clearances lead to errors in the X-axis and Y-axis directions of the end motion trajectories of the manipulators, and the track errors caused by double joint clearance A and B are approximately the sum of the track errors of two single joint clearances. The velocity and acceleration curves at the ends of the manipulators are pulse fluctuations due to the existence of clearances. The influence degree of single joint clearances A and single joint clearances B on the curve is similar, and the influence degree of double joint clearances A and B on the curve under coupling is much greater than that of single joint clearances. [ABSTRACT FROM AUTHOR]

In order to study the detection methods of weak transient electromagnetic radiation signals, a detection algorithm integrating generalized cross-correlation and chaotic sequence prediction is proposed in this paper. Based on the dual-antenna test and cross-correlation information estimation method, the detection of aperiodic weak discharge signals under low signal-to-noise ratio is transformed into the estimation of periodic delay parameters, and the noise is reduced at the same time. The feasibility of this method is verified by simulation and experimental analysis. The results show that under the condition of low signal-to-noise ratio, the integrated method can effectively suppress the influence of 10 noise disturbances. It has a high detection probability for weak transient electromagnetic radiation signals, and needs fewer pulse accumulation times, which improves the detection efficiency and is more suitable for long-distance detection of weak electromagnetic radiation sources. [ABSTRACT FROM AUTHOR]

Fast and selective detection of heavy metal ions in the aqueous phase plays a key role in meeting human health and environmental concerns. Herein we report a series of fluorene-based lanthanide metal–organic frameworks ([Ln2(FDC)3DMA(H2O)3]·DMA·4.5H2O, Ln = Sm (1), Eu (2), Gd (3) and Tb (4), H2FDC = 9,9-dimethyl-2,7-fluorenedicarboxylic acid, DMA = dimethylacetamide). Single crystal X-ray diffraction reveals that 1–4 are isostructural and display a 3D neutral framework. 2 exhibits intense characteristic red emission of Eu3+ ions in the solid state and high selectivity for Pb2+ and Fe3+ ions through fluorescence enhancement and the quenching effect in aqueous solutions, respectively. Interestingly, the fluorescence intensity of 2 shows a good linear relationship with Pb2+ concentration in the range of 0.02–0.1 mM. Furthermore, the dynamic and static quenching constants are calculated to be 320 M−1 and 10 680 M−1 by the fluorescence lifetime and titration experiments in low concentration of Fe3+. In addition, 4 exhibits different fluorescence response behaviors in the presence of Sm3+ or Eu3+ in aqueous solution. [ABSTRACT FROM AUTHOR]