Patent ID: 6123146
Filing Date: 2000-09-26
Classification: B60H

Abstract:
An apparatus for regulating the air temperature within a cabin of a vehicle having an engine, comprising:(a) a cooling loop having a compressor, a condenser and an evaporator;(b) a heating loop having a heating radiator and containing engine coolant fluid;(c) a blower unit which supplies air flow to the cabin;(d) an air treatment unit in communication with the evaporator and the heating radiator and having mixing valves for directing the air flow over the evaporator and/or the heating radiator to regulate the temperature of the air supplied to the cabin;(e) an air temperature sensor for detecting the temperature of the air in the cabin;(f) a setting module for selecting a desired temperature value of the air in the cabin;(g) a means for detecting the state of operation of the apparatus; and(h) a control unit for regulating the operation of the mixing valves, the blower unit, the cooling loop and/or the heating loop to achieve and maintain the cabin air temperature at or about the desired cabin air temperature value, the control unit comprising:i) a control module coupled to the setting module and the means for detecting the state of operation of the apparatus, the control module being adapted to determine the required adjustments for regulating the operation of the mixing valves, the blower unit, the cooling loop and/or the heating loop based on the prevailing cabin air temperature, the desired cabin air temperature value of the setting module and an estimated external air temperature; andii) an estimating module comprising(1) a first sub-module coupled to the air temperature sensor and the control module, the first sub-module being adapted to (a) generate an estimated external air temperature (i) when the apparatus is inoperative, (ii) when the apparatus is operative and the air temperature in the cabin is substantially the same as the desired temperature value of the setting module, and (iii) when the apparatus is operative and the air temperature in the cabin is substantially different from the desired temperature value of the setting module, and (b) supply an estimated external air temperature value to the control module;(2) a first sub-memory coupled to the first sub-module and adapted to store an estimated external air temperature value generated by the first sub-module; and(3) a second sub-memory coupled to the first sub-module and adapted to store data representing a differential equation for determining the estimated external air temperature based on the geometrical and structural features of the cabin and the energy flows between the apparatus and the cabin and between the cabin and the external atmosphere, the first sub-module being adapted to solve the differential equation and determine an estimated external air temperature.