This paper intends to establish a mathematical model based on the relations between “road”, “vehicle”, and “driver” for predicting the braking status on downhill drivings.
Surveys of different road conditions in the mountainous areas in the western as well as eastern districts in China were first carried out as the basis of investigations.
Taking different mountainous roads as composed of combinations of various kinds of short segments of road path with known gradients (it is referred to “element road”), and the vehicle as a moving mass with known parameters, getting the control behavior of drivers through statistics, we establish first the mathematical model of a single segment of road path with known gradient. Using this model as a base, we can establish then a generalized model by calculating through segment by segment for various kinds of hill slopes with different vehicles and braking requirements.
In a word, with known road data and vehicle parameter, the braking load can be easily determined with this model, especially when the computer is to be used.
Results of calculations with model were compared with results of actual tests. The differences between calculated results and test results are less than 20%, that is to say, the accuracy being over 80%.
The author recognizes this method is very useful to the development of the vehicle braking system.