Study on the symmetrical laser displacement sensor for the road surface measurement

The asymmetry imaging spot caused by the CCD saturation and the scattering of uneven road surface usually leads to lower accuracy in the road surface detection. A new method of the symmetric displacement sensor for the road measurement is given. The sensor consists of two symmetrical image systems and two line scan CCDs which are arranged reversely. The centroidal algorithm is adept to calculate the coordinates of the image point of each CCD. The finial displacement is given by the average of the coordinates of the image point of two CCDs. The experimental results indicate that the symmetrical laser displacement sensor can reduce the asymmetry imaging test error and improve the precision of measurement effectively. It is very suitable for the pavement evenness, rut and texture detection.