The final operating point is the operating point with the minimum impact factor. This strategy improves the overall performance of the HEV drivetrain but is computationally expensive.

State Machine Based

The state machine dictates the operating mode of the HEV such:

1. ENGINE (ICE propelling the vehicle)
2. BOOSTING (both ICE and EM propelling the vehicle)
3. CHARGING (ICE propelling the vehicle and charging the battery)

The transition between the operating modes is decided based on:

1. the change in driver demand
2. a change in vehicle operating condition
3. a system or a subsystem fault.

The various states involved in the control strategy are listed in Table 1 .

Table 1: States of an HEV

Implementation of a vehicle controller through state machines facilitates fault resilient supervisory control of the whole system.

 

 

References:

[1] A. E. Fuhs, Hybrid Vehicles and the Future of Personal Transportation , CRC Press, 2009