초록 ▼

A control method for a variable capacity automotive air conditioning compressor in which the compressor operating point is tailored to the nonlinear control characteristics of variable displacement compressors. When the error between the desired and actual values of a specified system parameter is r

A control method for a variable capacity automotive air conditioning compressor in which the compressor operating point is tailored to the nonlinear control characteristics of variable displacement compressors. When the error between the desired and actual values of a specified system parameter is relatively large, the operating point is determined by a coarse gain closed-loop control. When the error is within a fine control range defined in relation to the desired value, the control point is set to one of three predetermined values for effecting small displacement increases, small displacement decreases, or no change in displacement. An adaptive tuning technique is used to update the predetermined control point values to compensate for compressor-to-compressor differences and changes in the operating conditions of a given compressor system. An anticipation technique shortens the transition from coarse control to fine control by minimizing gross overshoots of the specified system parameter.

대표청구항 ▼

In an automotive air conditioning system including a refrigerant compressor having a capacity determined in accordance with the pressure in a control chamber thereof, and a control valve in communication with inlet and outlet ports of the compressor for effecting a ratiometric control of the pressur

In an automotive air conditioning system including a refrigerant compressor having a capacity determined in accordance with the pressure in a control chamber thereof, and a control valve in communication with inlet and outlet ports of the compressor for effecting a ratiometric control of the pressure in said control chamber, control apparatus comprising: means for measuring the value of a specified system parameter; means defining a fine control range of values in relation to a desired value of said specified system parameter and a deadband range of values within said fine control range; closed-loop control means effective when the measured value is outside said fine control range for operating the control valve at a setting determined at least in proportion to the difference between the measured and desired values; and open-loop control means effective when the measured value is within said fine control range for operating the control valve at (1) a first predetermined setting designed to change the capacity of the compressor in a direction to decrease the specified system parameter when the measured value is above said deadband range, (2) at a second predetermined setting designed to change the capacity of the compressor in a direction to increase the specified system parameter when the measured value is below said deadband range, and (3) at a third predetermined setting designed to maintain the current capacity of the compressor if the measured value is within said deadband range.