The adoption of the electronic controlled steering systems with new technologies has been extended in recent years. They have interactions with other complex vehicle subsystems and it is a hard task for the vehicle developer to find the best solution from huge number of the combination of parameter settings with track tests.
In order to improve the efficiency of the steering system development, the authors had developed a steering bench test method for steering system using a Hardware-In-the-Loop Simulation (HILS). In the steering HILS system, vehicle dynamics simulation and the tie rod axial force calculation are required at the same time in the real-time simulation environment. The accuracy of the tie rod axial force calculation is one of the key factors to reproduce the vehicle driving condition. But the calculation cannot be realized by a commercial software for the vehicle dynamics simulation. A multibody kinematics model of strut suspension was developed for the tie rod axial force calculation.
In this study, a new kinematics model of a double wishbone suspension system was developed for the tie rod axial force calculation. The evaluation of developed kinematics model was carried out by comparing the results of a kinematic analysis and the tie rod axial force calculation to those of ADAMS. Then the evaluation of the reproducibility of the vehicle driving condition in the steering HILS system was carried out by comparing the calculated vehicle behavior, measured tie rod axial force and measured steering torque to those of a track test using a prototype vehicle.
