Abstract: LiNi0.5Mn1.5O4 powders have been prepared by a solution combustion method at 300-800oC. X-ray diffraction (XRD) and scanning electric microscope (SEM) were used to determine the phase composition and micro morphology of the products. The results indicate that the products with single phase LiNi0.5Mn1.5O4 can be obtained at 400-600oC. The electrochemical performance was tested by a coin-type battery. The product prepared at 600oC has the best electrochemical performance. The maximum capacity of the product prepared at 600oC is 135mAh/g at the current density of 30mA/g, and after 30 cycles, the capacity fades little.
Abstract: Single phase Al3+ doped LiMn2O4 has been prepared by flameless solution combustion synthesis method at 600oC for 1h. X-ray diffraction (XRD) and scanning electric microscope (SEM) were used to determine the phase composition and micro morphology of the products. XRD analysis indicates that the purities increase and the lattice parameters of the products decrease with increasing Al3+ content. Electrochemical test indicates that the cycling performance of the products with Al3+ doping are better than that of the product without Al3+ doping. The product LiAl0.10Mn1.90O4 gets the best electrochemical performance. At the current density of 30mA/g, the initial discharge capacity of LiAl0.10Mn1.90O4 is 124.8mAh/g, and after 20 cycles, the capacity retention is more than 89%. SEM investigation indicates that the particles of LiAl0.10Mn1.90O4 are sub-micron in size and well dispersed.
Abstract: Video processing technology is regarded as a low-cost detection technology in complex environment. Because the placement layer is thin and the surface is complex that causes high detection error and high cost in laser measurement. Two problems must be solved before using it in large-scale composite structures automatic placement. One is to obtain the high-quality and stable image, and the other is to improve efficiency of image processing. In this paper, a method obtaining the high quality placement gap images was studied. It made use of the optical characteristics of composite material’s surface texture. And some parameters were determined by experiments. To reduce the calculation cost of image processing, a placement gap measurement method based on line scanning was also proposed here. The method was effective in our detection experiments on an actual workpiece.
Abstract: This paper presents a texture direction analysis method combing image segmentation and filtering, which makes use of the optical reflection characteristics of composite material’s surface texture. Firstly, segment the image using the centre of mass of the two-dimensional histogram; secondly, the binary image is smoothed by a median filter to improve texture directional information. Experimental results show that the proposed method is outstanding in segmentation quality, so it could meet the stability requirements in automatic placement.
Abstract: Nowadays, the hydraulic straightening presses play an important role in straightening mandrels. For different mandrels, straightening forces and reductions differ. So the proportional position control system under pressure boundary conditions is required. The mathematical model of the system is deduced, and simulation of the system is carried out by MATLAB. The curves of step response and Bode diagram show that the system is steady and quick-response. The error caused by load is analyzed, which meets the straightening requirements and validates its design. The work in this paper can provide a high guidance for presses of similar kinds.
Abstract: Considering the work environment and characteristics of wall-climbing robot, a kind of real-time obstacle avoidance method based on stereovision is proposed. In order to improve veracity and speediness, the mathematical model of parallel binocular stereovision is built, and a homonymy point matching algorithm based on correlation of region and boundary is presented. The results indicate that this method has good characteristics of reducing data processed, improving celerity, which can realize of obstacle avoidance easily and reliably.
Abstract: As a skeletal muscle-like actuator, PAM possesses many unique advantages. They include compliance and high power-to-weight ratio, which make it an ideal actuator for robotic and powered exoskeleton applications. But its flexible braided mesh shell and the compressibility of air make PAM much more difficult to model and control compared to traditional actuators. In this work, the mechanical properties of the McKibben PAM produced by Festo are examined, tested and discussed. The results demonstrate the muscle-like property of PAM and its strong non-linear and hysteresis behaviors. A simple law between the areas of the hysteresis and pressure is proposed, and the relationships of the areas of the hysteresis, external load and the continuous working time are studied. Further, changing the PAM length that is smaller than 0.4 mm may lead to the “crawl” phenomenon. Finally, the empirical results can be used in compensation-based controls of the hysteresis in the McKibben PAM.
Abstract: Photolithography area is usually a bottleneck area in a semiconductor wafer manufacturing system (SWMS). It is difficult to schedule photolithography area on real-time optimally. Here, an Elman neural network (ENN)-based dynamic scheduling method is proposed. An ENN-based sample learning algorithm is proposed for selecting best combination of scheduling rules. To illustrate the feasibility and practicality of the presented method, the simulation experiment is developed. A numerical example is use to evaluate the proposed method. Results of simulation experiments show that the proposed method is effective to schedule a complex wafer photolithography process.