Pavement Macrotexture Evaluation for Tire Test Benches using Surface Profile Measurements

This paper presents a new approach to evaluating the characteristics of structured metal strips used to simulate road surfaces during the testing of car tires. The new computation procedure yields more realistic and reliable results than the methods proposed in the ISO 13473-1. The proposed virtual volumetric patch method (VVPM) takes advantage of the fact that the instrument yields measurement data on a regular grid, corresponding to a patch of the surface. This permits the implementation of the primary computations as tensors, yielding a simple and numerically efficient solution. Tensor polynomials are used to eliminate low frequency distortions of the strip, resulting from inner tensions, which would otherwise negatively influence the computed characteristics. The VVPM estimates the equivalent volume of water that could be embedded in the road surface, prior to the surface becoming submerged. This also yields an estimate for the true texture depth. The new approach, with the gridded nature of the data, also enables the computation of texture randomness and coherence wavelengths. Yielding additional valuable information about the structure of the surface. Real-world measurement data were acquired from a test bench; one such data set is used throughout the paper to demonstrate the effectiveness of the proposed processing.