US 5,489,777 A · Apparatus for remote analysis of vehicle emissions using reflective thermography

Abstract

A system for remote analysis of vehicle emissions also determines whether each vehicle's engine and exhaust system are hot or cold by measuring infrared radiation reflected by the roadway beneath the vehicle. A source transmits a beam of radiation through at least a portion of the motor vehicle exhaust to a number of sensors. Each sensor generates a signal indicative of the absorption of the beam in a wavelength band indicative of a corresponding exhaust gas (e.g., CO, CO.sub.2, HC, NO.sub.x and H.sub.2 O). An infrared detector measures infrared radiation within a field of view including at least a portion of the roadway beneath each passing vehicle. A processor then computes the concentrations of each exhaust gas from the sensor signals, and determines whether the vehicle is hot or cold by measuring the intensity of infrared radiation detected by the infrared detector. Because cold vehicles can temporarily produce abnormally high pollution emissions, the processor can be programmed to separately identify hot vehicles having exhaust emissions that exceed air pollution limits. The system can also include a video camera and recorder to record the license plate and emissions data for each vehicle identified as failing to meet emissions limits.

Claims25

Dependent claims

A system for remotely identifying the thermal state of motor vehicles on a roadway, each vehicle having an engine and exhaust system components (the "components") which may initially be cold after said engine is first started (the "cold state") and which become hot after a period of operation (the "hot state");

wherein said components in said hot state emit substantially more infrared radiation than components in said cold state, with at least a portion of said infrared radiation being directed toward said roadway;
said system comprising:
an infrared detector for detecting infrared radiation within a field of view including at least a portion of said roadway beneath said vehicle;
and
a processor for determining whether said vehicle is in said hot state by measuring the intensity of infrared radiation detected by said infrared detector while said vehicle is within said field of view.

2 more elements

A gas analysis system for remotely identifying moving motor vehicles on a roadway having concentrations of exhaust gases above predetermined limits, each of said vehicles having an engine and exhaust system components (the "components") that may initially be cold after said engine is first started (the "cold state") and that become hot after a period of operation (the "hot state");

wherein said components in said hot state emit substantially more infrared radiation than components in said cold state, with at least a portion of said infrared radiation being directed toward said roadway;
said system comprising:
a source for producing and transmitting a beam of radiation through at least a portion of the exhaust of a motor vehicle;
and
a plurality of sensors for receiving said beam, each sensor generating a signal indicative of the absorption of said beam in a wavelength band indicative of a corresponding one of said exhaust gases;
an infrared detector for detecting infrared radiation within a field of view including at least a portion of said roadway beneath said vehicle;
and
a processor responsive to said sensors for computing the concentrations of said exhaust gases in the path of said beam through said exhaust, and for determining whether said vehicle is in said hot state by measuring the intensity of infrared radiation detected by said infrared detector while said vehicle is within said field of view, said processor identifying each vehicle for which said concentrations of said exhaust gases exceed said predetermined limits if said vehicle is determined to be in said hot state.

5 more elements

A gas analysis system for remotely identifying moving motor vehicles on a roadway having concentrations of exhaust gases above predetermined limits, each of said vehicles having an engine and exhaust system components ("components") that may initially be cold after said engine is first started (the "cold state") and that become hot after a period of operation (the "hot state");

wherein said components in said hot state emit substantially more infrared radiation than components in said cold state, with at least a portion of said infrared radiation being directed toward said roadway;
said system comprising:
a source for producing and transmitting a beam of radiation through at least a portion of the exhaust of a motor vehicle;
a plurality of sensors for receiving said beam, each sensor generating a signal indicative of the absorption of said beam in a wavelength band indicative of a corresponding one of said exhaust gases;
an infrared detector for detecting infrared radiation within a field of view including at least a portion of said roadway beneath said vehicle;
a visible light detector for detecting visible light within a field of view that at least partially overlaps said field of view of said infrared detector;
and
a processor responsive to said signals from said sensors for computing the concentrations of said exhaust gases in the path of said beam through said exhaust, and for determining whether said vehicle is in said hot state by measuring whether the intensity of infrared radiation detected by said infrared detector exceeds a first predetermined limit and the intensity of visible light detected by said visible light detector does not exceed a second predetermined limit while said vehicle is within said field of view, said processor identifying each vehicle for which said concentrations of said exhaust gases exceed said predetermined limits if said vehicle is determined to be in said hot state.

5 more elements

wherein said components in said hot state emit substantially more infrared radiation than components in said cold state, with at least a portion of said infrared radiation being directed toward said roadway;
said system comprising:
a source for producing and transmitting a beam of radiation through at least a portion of the exhaust of a motor vehicle;
and
a plurality of sensors for receiving said beam, each sensor generating a signal indicative of the absorption of said beam in a wavelength band indicative of a corresponding one of said exhaust gases;
an infrared detector for detecting infrared radiation within a field of view including at least a portion of said roadway beneath said vehicle;
a processor responsive to said sensors for computing the concentrations of said exhaust gases in the path of said beam through said exhaust, and for determining whether said vehicle is in said hot state by measuring the intensity of infrared radiation detected by said infrared detector while said vehicle is within said field of view, said processor identifying each vehicle for which said concentrations of said exhaust gases exceed said predetermined limits if said vehicle is determined to be in said hot state;
a camera aligned to record an image of each vehicle identified by said processor, including any vehicle identification material displayed on said vehicle;
and
storage means for storing said vehicle image together with data regarding said exhaust gas concentrations measured for said vehicle.

7 more elements

Dependencies are inferred from the claim text.

Apparatus for remote analysis of vehicle emissions using reflective thermography

Life of this patent

Apparatus for remote analysis of vehicle emissions using reflective thermography

Life of this patent

Abstract

Claims25