Capability study of a laser equipped balancing machine and algorithm development for assessing tire geometrical non uniformities

Abstract

Tires are highly engineered products which have to be designed to meet several performances such as ride, handling, traction, etc. Tire subjective evaluation is still the key criteria to get an original equipment manufacturers approval. For this subjective evaluation, it is essential to select assemblies with best uniformities in order to avoid vibrations which could disturb the driver during its subjective assessment. New generations of balancing ma- chines provide capabilities to measure geometrical uniformity. The main goal of this thesis is to assess the measurement capabilities of such a laser equipped machine. This machine is going to be used for quick selection of best uniformity assemblies. For this purpose, measurements of this machine are compared to the measurements of another reference ma- chine. A feasibility study is conducted in this report in order to frame a robust comparison method between the two machines. The second goal of the project is the development of several indicators in order to correctly describe the uniformity of assemblies based on laser measurements. These indicators are extracted directly from the tire con- tour which is obtained after a test on the machine. Speci cally, one of the objective is to develop an algorithm in order to evaluate the lateral tread shift.