A novel wear angle determination algorithm for wear image based on direction correlation of wear scar

A lubricant is a substance that lessens friction and wear between mechanical parts. A good quality lubricating oil is required for protecting the mechanical equipment and reducing energy consumption. Its performance index (friction coefficient) could be measured by the four-ball wear test. For the morphological analysis of testing data from the four-ball wear test, determination of wear angle is very important for measuring the wear spot diameter, validity of the four-ball wear test and recognition of abnormal wear scar. On the basis of character analysis and image processing technology, a novel wear angle determination algorithm for wear scar is presented in this article. The direction of the wear scar (wear angle) is determined based on angle transformation and grey consistency (the smallest change of grey level). Simulation results show that the algorithm has high precision, good robustness and less time consuming. The average absolute error of our method is 0.8° and the absolute error of 95% of samples is <4°. The average runtime per frame is 3.896 s in the simulation platform.

Correlation study of fuel injection strategies on engine emission and lubricating oil performance

Based on different fuel injection strategies, this paper analyzes the factors such as engine original emission smoke, exhaust temperature, soot content, wear spot diameter and kinematic viscosity. The study found that delaying injection timing, increased afterburn, engine original soot emissions, exhaust gas temperature increase, but will increase the thermal load of the parts. At the same time, the growth rate of lubricant soot and kinematic viscosity increased; The wear spot diameter at the same soot content is reduced, and the wear is reduced. In the end, the paper finally selects 1°CA BTDC as the optimal fuel injection strategy to achieve rapid aging of engine lubricating oil in order to complete the assessment of the anti-wear performance of lubricating oil.