Abstract:

An analytical co-relationship between the steering angles of the steering wheels in a double front axle steering vehicle was deduced by using space coordinate transformation theory to optimize a steering mechanism. A design problem of the steering mechanism was optimized and improved mathematically in a double front axle steering vehicle according to the Ackermann′s principle, by taking the maximum absolute value of steering error as the objective function, with the help of visualization technology such as contour maps of the maximum absolute steering errors of wheels and the minimum transmission angles in steering mechanism. The results show that the absolute steering errors on all steering wheels are less than 1.18° in allowable range of the wheel steering motion, and the steering trapeziums have a suitable minimum transmission angles. This method avoids the blindness in optimization process, and is easy to get suitable trapezoidal parameters that meet actual conditions. The suggestions are taking suitable steering trapezium arm length as the lower limit of optimization, and ensuring the steering wheels exactly fulfill the pure rolling at three positions when vehicle travelling.

Key words: vehicle engineering , steering systems ,  double-axle steering mechanism , Ackermann steering principle ,  kinematics analysis , optimization design , visualizing synthesis.