Inter-vehicle distance estimation considering camera attitude angles based on monocular vision

Perceiving the distance between vehicles is a crucial issue for advanced driving assistance systems. However, most vision-based distance estimation methods do not consider the influence of the change in camera attitude angles during driving or only use the vanishing point detected by lane lines to correct the pitch angle. This paper proposed an improved pinhole distance estimation model based on the road vanishing point without the lane line information. First, the road vanishing point is detected based on the dominant texture orientation, and the yaw and pitch angles of the camera are estimated. Then, a distance estimation model considering attitude angle compensation is established. Finally, the experimental results show that the proposed method can effectively correct the influence of the camera attitude angle on the distance estimation results.

Effect of Drawing Pass on Softening or Plasticizing of Q235 Steel Bar during Electrochemical Cold Drawing

In this work, the effect of drawing pass on the surface layer softening or plasticizing of Q235 steel bar during electrochemical cold drawing (ECD) was studied, as well as cold drawing in air (DIA) for comparison. The results indicate that the softening or plasticizing degree gradually decreases with increasing drawing pass. The reason for this should be that dislocations generated in surface layer are only partially overflowed from the surface in the form of additional dislocation flux. The general dislocation density thereby gradually increases with the increase in drawing pass, resulting in the increase in the work hardening degree of the surface layer, and thus, the drawing stress. In this case, the texture orientation of the bar surface layer is gradually enhanced. In contrast, the dislocation density, and thus the work hardening degree of DIA bar, are higher than those of the ECD partner, resulting in larger drawing stress. ECD can obtain a product with excellent comprehensive mechanical properties compared with DIA, and there are no cracks on the fracture surface of ECD bar drawn for at least seven passes.

Changer in the texture orientation of electrolytic nickel by cold air plasma

The effects of cold air plasma influence on the change in the microstructure, stress state and texture of the cathode nickel brand H-1 were studied. By the method of target metallography it has been established that the microstructure does not change under exposure to the cold air plasma. A decrease in the level of micro- and macrostress is shown. By the method of inverse pole figures it has been established that the pole density of the orientations (111), (200) and (311) decreases when exposed to plasma; orientation (311) changes the least intensively. The pole density of the orientation (220) increases from 4.42 in the initial state to 13.3 after plasma treatment, which means an increase in the electrolytic deposition texture. The causes of the observed effects are being discussed. It is assumed that the changes introduced by the plasma occur at a scale level that is much smaller than the size of the coherent scatter blocks.

Substrate curvature governs texture orientation in thin films of smectic block copolymers

An effective field theory of finite-thickness block copolymer films shows how curvature can control texture formation.

Influence of Nanoscale Textured Surfaces and Subsurface Defects on Friction Behaviors by Molecular Dynamics Simulation

In nanomaterials, the surface or the subsurface structures influence the friction behaviors greatly. In this work, nanoscale friction behaviors between a rigid cylinder tip and a single crystal copper substrate are studied by molecular dynamics simulation. Nanoscale textured surfaces are modeled on the surface of the substrate to represent the surface structures, and the spacings between textures are seen as defects on the surface. Nano-defects are prepared at the subsurface of the substrate. The effects of depth, orientation, width and shape of textured surfaces on the average friction forces are investigated, and the influence of subsurface defects in the substrate is also studied. Compared with the smooth surface, textured surfaces can improve friction behaviors effectively. The textured surfaces with a greater depth or smaller width lead to lower friction forces. The surface with 45° texture orientation produces the lowest average friction force among all the orientations. The influence of the shape is slight, and the v-shape shows a lower average friction force. Besides, the subsurface defects in the substrate make the sliding process unstable and the influence of subsurface defects on friction forces is sensitive to their positions.