US Patent No. 10,558,227

SYSTEM AND METHOD FOR OUTPUT COMPENSATION IN FLOW SENSORS USING PULSE WIDTH MODULATION


Patent No. 10,558,227
Issue Date February 11, 2020
Title System And Method For Output Compensation In Flow Sensors Using Pulse Width Modulation
Inventorship Carlos Felipe Alcala Perez, Milwaukee, WI (US)
Kirk H. Drees, Cedarburg, WI (US)
Timothy I. Salsbury, Mequon, WI (US)
Assignee Johnson Controls Technology Company, Auburn Hills, MI (US)

Claim of US Patent No. 10,558,227

1. A system for monitoring and controlling flow rate of a fluid through a valve, the system comprising:a flow rate sensor configured to measure the flow rate of the fluid through the valve; and
a controller in communication with the flow rate sensor and configured to:
receive the measured flow rate from the flow rate sensor;
determine if the measured flow rate is equal to a predetermined flow rate value; and
in response to a determination that the measured flow rate is equal to the predetermined flow rate value:
determine a minimum valve position threshold (xmin);
determine a minimum flow rate threshold (ymin) corresponding to xmin;
generate a pulse-width modulated (PWM) signal;
calculate a corrected flow rate (?f) using the PWM signal; and
control a valve operation using the corrected flow rate (?f);
wherein the PWM signal is configured to switch between zero and ymin.