Twin fan control system and method

A control system for controlling the speed of two fans for cooling four fluids in a work machine, each fluid being associated with a particular heat transfer core and each fluid being operable between a predetermined minimum threshold temperature and a predetermined maximum threshold temperature, the control system comprising:

• a first sensor positioned to sense the temperature of the first fluid and to output a signal indicative thereof;
• a second sensor positioned to sense a temperature of the second fluid and to output a signal indicative thereof;
• a third sensor positioned to sense a temperature of the third fluid and to output a signal indicative thereof;
• a fourth sensor positioned to sense a temperature of the fourth fluid and to output a signal indicative thereof;
• an electronic controller coupled with said first, second, third and fourth sensors for receiving signals therefrom, said controller being operable to receive a signal from each of said sensors indicative of the temperature of said first, second, third and fourth fluids respectively;
• said controller being further operable to determine a first temperature error for the signal received from said first sensor, a second temperature error for the signal received from said second sensor, a third temperature error for the signal received from said third sensor, and a fourth temperature error for the signal received from said fourth sensor, each of said temperature errors being computed based upon a difference between a predetermined desired threshold temperature for that particular fluid and the temperature of that particular fluid as indicated by the signal received from that fluid's sensor;
• said controller being further operable to determined a fan speed for said first and second fans based upon a comparison of at least some of the temperature errors determined from said first, second, third and fourth sensors;
• and
• said controller being further coupled to the drive motor of said first fan and to the drive motor of said second fan and outputting a signal respectively thereto to control the speed of said first and second fans, each output signal being indicative of a desired fan speed for that particular fan.

A method for controlling the speed of a plurality of fans for cooling a plurality of fluids in a work machine, each of said plurality of fluids being operative between a predetermined minimum threshold temperature and a predetermined maximum threshold temperature, said method comprising the steps of:

• positioning a plurality of sensors to sense the temperature of each of the plurality of fluids, each sensor being operable to output a signal indicative of the temperature of that particular fluid;
• coupling an electronic controller with said plurality of sensors for receiving signals therefrom, said controller being operable to receive a signal from each of said plurality of sensors indicative of a temperature for each of the plurality of fluids;
• operably determining a desired fan speed for each of said plurality of fans based upon signals received from said plurality of sensors utilizing said controller;
• and
• outputting a signal to each of said plurality of fans to individually control the speed thereof utilizing said controller, each output signal being indicative of a desired fan speed for a particular fan and each output signal being based upon a comparison of at least some of the signals received from said plurality of sensors.