Sensor assembly and method

• US 8,082,807 B2
• Filed: 06/02/2008
• Issued: 12/27/2011
• Est. Priority Date: 06/02/2008
• Status: Active Grant

• Current Assignee: Custom Sensors & Technologies Incorporated (Schneider Electric SE)
• Original Assignee: Custom Sensors & Technologies Incorporated (Schneider Electric SE)
• Inventors: Casey, Gary, Nguyen, Nhan
• Primary Examiner(s): Kirkland, III, Freddie
• Application Number:
  US12/131,879
• Publication Number:
  US 20090293584A1
• Time in Patent Office: 1,303 Days
• Field of Search: 73/16.3, 737/14, 737/18, 738/625.81
• US Class Current: 73/862.581
• CPC Class Codes: G01D 11/245 Housings for sensors
• CPC Class Codes: G01D 3/036 on measuring arrangements themselves
• CPC Class Codes: G01L 15/00 Devices or apparatus for measuring two or more fluid pressure values simultaneously
• CPC Class Codes: G01L 9/125 with temperature compensating means non electric temperature compensating means G01L19/04

Abstract

Described herein is the sensor assembly and method for rapidly obtaining accurate readings of a variable. The sensor assembly comprises a plurality of sensors which are connected to a microcontroller that processes the signals of the individual transducers to the microcontroller. The microcontroller contains software that maximizes the refresh rate and/or minimizes the time it takes to process the outputs of each of the transducers. The microcontroller that is coupled to the sensor assembly selectively measures the outputs of each transducer so as to speed up the refresh rate of the sensor.

Claims

1. A sensor assembly for detecting a required variable, comprising:

a plurality of sensors with digital outputs, each of the plurality of sensors configured to detect an output responsive to a required variable and to detect a reference output representative of a reference characteristic independent of the required variable to compensate for an effect of the reference characteristic on the detected output responsive to the required variable, and

a microcontroller coupled to the output of each sensor, to control whether the reference output or the output responsive to the required variable of at least a selected one of the plurality of sensors is detected and when.

2. The sensor assembly of claim 1, wherein the reference output is used to compensate for one or more environmental effects on the output responsive to the required variable in order to accurately determine the value of the variable.

3. The sensor assembly of claim 1 further comprising an interrupt configured to detect the rising edge of each incoming pulse train representing the output responsive to the required variable of each sensor and further configured to measure the time it takes for a preselected number of incoming pulse trains to be detected and thereafter dividing that time by the preselected number to obtain an average pulse width for the output responsive to the required variable for each sensor, and after a predetermined number of averages has been obtained to repeat the procedure to capture the average reference pulse width for each sensor, and thereafter to repeat the process.

4. The sensor assembly of claim 1 further comprising a first layer having ports therein for exposing the plurality of sensors to the required variable.

5. The sensor assembly of claim 1 further comprising a layer on which the plurality of sensors and the microcontroller is located.

6. The sensor assembly of claim 5 further comprising a top layer having ports therein for exposing the plurality of sensors to the variable and a bottom rigid layer with low thermal expansion on which the sensor layer is mounted.

7. A pressure sensor assembly, comprising:

a plurality of pressure sensors, each capable of detecting a pulse responsive to pressure and a reference pulse representative of one or more environmental effects independent of the pressure; and

a microcontroller configured to measure the two pulses detected by each of the plurality of pressure sensors, such that the reference pulse of a particular sensor is used to compensate for the environmental effects on the pressure pulse detected by that same sensor to determine the pressure on a particular sensor;

wherein the microcontroller is configured to determine which pulses of which sensors are measured.

8. The pressure sensor assembly of claim 7, further comprising an interrupt configured to detect the rising edge of each incoming pulse train representing the pressure output of each sensor and further configured to measure the time it takes for a preselected number of incoming pulse trains to be detected and thereafter to divide that time by the preselected number to obtain an average pulse width for the pressure output for each sensor, and after a predetermined number of averages has been obtained for the pressure output of a sensor to repeat the procedure to capture the average reference pulse width for that sensor, and thereafter to repeat the process.

9. A method for detecting pressure in an automatic transmission having a plurality of clutches and an engine control unit (ECU), the method comprising:

coupling each of the plurality of clutches to a respective sensor of a plurality of sensors located within a pressure assembly comprising the plurality of sensors;

detecting the pressure of each clutch as needed by detecting the pressure on a corresponding sensor a selected number of times and thereafter using a reference output detected by that sensor, the reference output representative of one or more environmental effects independent of the pressure, to compensate for the environmental effects of the detected pressure on that sensor so that a true pressure may be obtained.

10. The method of claim 9, wherein detecting the pressure of each clutch is performed by a microcontroller.

11. The method of claim 9, wherein detecting the pressure of each clutch is performed by the ECU.

12. The method of claim 9, further comprising:

calibrating the measurements of the pressure for each of the plurality of clutches using calibration coefficients for each sensor, and

determining if the reference output needs to be updated.