REDUCING PITCH ANGLE AND SUSPENSION JOUNCES OF A TRUCK WHEN BRAKING ON RAILWAY CROSSING BY CONTROL OF SEMI-ACTIVE SUSPENSION

This paper presents pith plane dynamic model of a cargo truck. Numerical simulations for determination of a pitch angle and deflection in front and rear suspension under braking on railway crossing are conducted. The change of the braking force is presented by trapezoidal form, similar to the theoretical law of variation of braking deceleration in the braking diagram of road vehicles. For the railway crossing profile trapezoidal function is used too. The numerical simulations are carried out in program field of MATLAB. After conducting tests for determination of a braking dynamics and braking properties of a truck in road conditions, the pith plane model is validated. Possibilities for pitch angle and suspension jounces reduction are given. A fifth wheel assembly, displacement sensors and data acquisition system are used in the road tests