The usage of a laser height sensors for estimating road unevenness profile

Abstract

The paper presents results of simulation and experimental tests of proposed algorithm of compensation vehicle vertical and pitch dynamics in laser signals to get an estimation of road unevenness profile. In the beginning of the paper the problem of defining actual road unevenness profile height was described and a method to solve this problem was proposed. The described problem arises from the fact that measurement of the distance between laser height sensor and road is done with a sensor mounted to the vehicle body, which have its own dynamics. The method of compensation laser sensor signal for body movement – pitch and heave – was proposed and tested with simulation and experimental tests. For simulation tests half car model implemented in a Simulink and Matlab was used and for experimental test passenger car Opel Astra was used with algorithm implemented in dSpace electronic control unit prototyping system. Simulation test proved that the idea is correct and allows to fully compensate laser signal for body movement. Experimental test showed that method is easy to implement and fully effective in a simulation environment but is much more complicated with a real application. It is because information about body movement is not accurate as in a simulation and a special signal processing methods need to be added to procedure working with a simulation signals. Acceleration signals must be integrated with use of a special band pass filtering, but with its use it is able to get good results of compensation also with a real car and real sensor signals.