Patent Document ID: 5570838
Application ID: 08363076
Patent Flag: 1

Claim One:
1. A method for automatically controlling a heating, ventilation and air conditioning (HVAC) system for increased comfort of an occupant in a vehicle which discharges a flow of air to a passenger cabin of the vehicle, the system including a variable speed blower, means for varying air temperature, ducting, actuators having various control positions for controlling the direction of air flow, an intake door having varying control positions for controlling the ratio of fresh air to recirculated air, a humidity sensor for sensing relative humidity within the cabin and generating a corresponding humidity signal, and temperature sensors for sensing temperature within the cabin and ambient temperature and an adjustable target temperature, the method comprising the steps of: determining relative humidity based on the humidity signal; determining ambient temperature; determining temperature within the cabin; determining standard effective temperature based on the humidity signal; determining the difference between standard effective temperature (SET) within the cabin and the target temperature to obtain a difference sign; defining membership functions and fuzzy rules between the relative humidity, ambient temperature, the difference signal and the control positions of the intake door; and generating a control signal to control the position of the intake door to cause the system to discharge air into the cabin having a desired ratio of fresh air to recirculated air based on the relative humidity, ambient temperature, the temperature within the cabin, the difference signal, the membership functions and the fuzzy rules.