HBS Model

HiP-HOPS is a flexible tool and it is capable of analysing models developed with Matlab Simulink or ITI Simulation X, for example. A top level HBS model, relating to the early stages of system design, was built using Simulink. For better illustration, the architecture is simplified and only the braking of one wheel is considered in the model presented here.

Fig. 3 - HBS Simulink Model

 

The system behaviour considered in this model is as follows:

The driver's action on the mechanical pedal is sensed and processed at the electronic pedal. The latter acts as a central control unit that coordinates 4 local wheel controllers according to the pilot's braking intentions. All the referred units are interconnected through a digital communication network. After receiving the braking force demand for the wheel it is responsible for, every local unit calculates the amount of torque to be developed by each actuator and then controls them accordingly through power electronics. When braking is taking place, power flows from the low voltage battery (auxiliary battery) to the EMB and from the IWM to the high voltage battery (powertrain battery). The haptic feedback that should be provided to the driver according the braking action is neglected in this model.