System and method for estimating ambient humidity

Patent metadata

Field	Value
Publication number	US-9863336-B2
Application number	US-201414286631-A
Country	US
Kind code	B2
Filing date	May 23, 2014
Priority date	May 23, 2014
Publication date	Jan 9, 2018
Grant date	Jan 9, 2018

Abstract

Methods and systems are provided for estimating ambient humidity based on a wet bulb temperature and a dry bulb temperature during precipitation, and estimating ambient humidity based on the dry bulb temperature and not based on wet bulb temperature when precipitation is absent.

First claim

The invention claimed is:

1. A method for an engine of a road vehicle having wheels, comprising:
during a first condition when a difference between a first temperature of a first sensor positioned at an exterior surface of the vehicle and exposed to weather and a second temperature of a second sensor shielded from weather is greater than a threshold temperature, estimating a first humidity based on the second temperature and the first temperature, and adjusting operation of the engine based on the first humidity; and
during a second condition when the difference between the first temperature and the second temperature is less than the threshold temperature, estimating a second humidity based on the second temperature and not based on the first temperature, and adjusting operation of the engine based on the second humidity.

2. The method of claim 1 , wherein the first temperature is a temperature of rain measured by a first temperature sensor located at one of a vehicle grille shutter, a side view mirror, or a base of a windshield, and wherein the second temperature is measured by a second temperature sensor located in an intake passage of the engine.

3. The method of claim 1 , wherein adjusting operation of the engine includes one or more of adjusting a mass air flow, spark timing, variable valve timing, or exhaust gas air-fuel ratio.

4. The method of claim 1 , further comprising inferring rain based on the first condition.

5. The method of claim 4 , further comprising determining a dew point temperature based on the first temperature and the second temperature, and determining fog in an environment surrounding the vehicle based on a difference between the dew point temperature and the second temperature being less than a threshold fog temperature.

6. The method of claim 5 , further comprising determining black ice in the environment surrounding the vehicle based on a difference between the dew point temperature and the second temperature being less than a threshold black ice temperature, and further based on the second temperature being less than a black ice temperature.

7. The method of claim 6 , further comprising transmitting information based on the determined rain, fog, and black ice from a controller of the engine to an off-board network via a wireless network.

Assignees

• Ford Global Tech Llc

Inventors

• Macneille Perry Robinson
• Weber David Charles

Classifications

• F02P5/1514

  with means for optimising the use of registers or of memories, e.g. interpolation · CPC title

• F02D2041/001

  for engines with variable valve actuation · CPC title

• F02D2200/703

  Atmospheric pressure · CPC title

• F02D2200/0414

  Air temperature · CPC title

• F02D41/1401

  characterised by the control or regulation method (F02D41/1473, F02D41/1477 take precedence) · CPC title