Unmanned integrated optical remote emissions sensor (RES) for motor vehicles

Abstract

An unmanned integrated RES 12 integrates all of its components except the reflector 22 into a single console 30 that is positioned at the side of a road and has a CPU 36 that controls calibration, verification and data gathering. The RES's source 32 and receiver 34 are preferably stacked one on top of the other such that the IR beam 24 traverses a low and high path as it crosses the road 14. This allows the RES to detect both low and high ground clearance vehicles. To maintain the vehicle processing and identification throughput, the speed sensor 54 and ALPR 48,50 detect the passing vehicles at steep angles, approximately 20 to 35 degrees. In a preferred system, a manned control center 16 communicates with a large number of the unmanned integrated RES to download emissions data, perform remote diagnostics, and, if necessary, dispatch a technician to perform maintenance on a particular RES.

1. An unmanned optical  emissions sensor for sensing a gas mixture composition of an exhaust plume of a motor vehicle travelling along a road , comprising:
 a source for radiating a beam of light  radiation along a path across a road  such that the beam passes through the exhaust plume of a passing vehicle and otherwise passes through ambient air;  
 a receiver for sampling radiation levels at a plurality of predetermined wavelengths from the beam;  
 a canister for emitting a puff of calibration gas in the path of the beam between the source and the receiver, said calibration gas having a known reference composition of gas which absorbs radiation at the predetermined wavelengths;  
 a data processing computer for computing a gas mixture composition from the sensed  sampled radiation levels in accordance with stored calibration curves;  
 a trigger device that produces a trigger signal when a vehicle passes through the beam causing the data processing computer to record the gas mixture composition of the vehicle's exhaust plume for a period of time;  
 an automated control computer that 
 a) calibrates the data processing computer by directing the canister to emit a puff of calibration gas, whereby the data processing computer recomputes  computes the calibration curves in accordance with the known reference composition;  
 b) verifies the calibration by directing the canister to emit a puff of calibration gas, whereby the data processing computer computes a test composition from the radiation levels and accepts the calibration when the test composition is close enough to the known reference composition and otherwise rejects the calibration and initiates recalibration  a new calibration; and  
 c) monitors the gas mixture composition of the ambient air to control recalibration  calibration of the data processing computer; and  
 
 a vehicle identification device that responds to the trigger signal by recording a vehicle identification for the passing vehicle.  
 
     
     
       2. The unmanned optical  emissions sensor of  claim 1 , further comprising:
 a multi-position lens cover on the receiver, said automated control computer indexing the position of the lens cover when the gas mixture composition of the ambient air deviates from an ambient reference level by more than a specified threshold and initiates recalibration  a new calibration if the deviation remains greater than the specified threshold.  
 
     
     
       3. The unmanned optical  emissions sensor of  claim 1 , wherein the automated control computer monitors the gas mixture composition of the vehicle's exhaust plume to control reverification  verification of the calibration and initiation of a new calibration. 
     
     
       4. The unmanned optical  emissions sensor of  claim 1 , wherein the automated control computer monitors a time from the last calibration and when the time exceeds a mandatory recalibration period it initiates another  a new calibration. 
     
     
       5. The unmanned optical  emissions sensor of  claim 1 , wherein the automated control computer monitors the data processing computer and power cycles the emissions sensor when the data processing computer fails to produce gas mixture compositions. 
     
     
       6. The unmanned optical  emissions sensor of  claim 1 , further comprising:
 a manned  control center; and  
 a communications channel for communication between the automated control computer and the manned  control center, said automated control computer responding to repeated calibration rejections by transmitting a help message to the manned  control center, which in turn responds by performing diagnostics to determine a cause for the calibration rejection and then either remedy  remedies the cause remotely or dispatch  dispatches a technician to remedy the cause on site.  
 
     
     
       7. The unmanned optical  emissions sensor of  claim 1 , further comprising:
 a vehicle detector for sensing an oncoming  a vehicle and computing its acceleration, said data processing computer disabling the recordation  a recording of the gas mixture composition of the vehicle's exhaust plume when the acceleration exceeds a threshold.  
 
     
     
       8. The unmanned optical  emission sensor of  claim 7 , wherein the vehicle detector compute's  computes the vehicle's speed and computes the time-to-trigger range from the vehicle's measured speed and acceleration, said data processing computer disabling the recordation  a recording of the gas mixture composition of the vehicle's exhaust plume when triggering  the trigger signal occurs outside the time-to-trigger range. 
     
     
       9. The unmanned optical  emissions sensor of  claim 7 , wherein said source and said receiver are placed on the same side of the  a road, further comprising:
 a reflector that is positioned on the other side of the road such that the beam emitted by the source reflects off of the reflector and back to the receiver.  
 
     
     
       10. The unmanned optical  emissions sensor of  claim 9 , further comprising:
 a single console that contains  comprises the source, the receiver, the canister, the data processing computer, the automated control computer, the vehicle identification device, and the vehicle detector.  
 
     
     
       11. The unmanned optical  emissions sensor of  claim 10 , wherein the vehicle identification device comprises an automated license plate reader (ALPR) that reads the vehicle's license at an angle of at least 20 degrees and said vehicle detector senses the oncoming vehicle at an angle of at least 20 degrees to maintain a vehicle throughput . 
     
     
       12. The unmanned optical  emissions sensor of  claim 10 , wherein one of said source and said receiver is positioned above the other so that the beam traverses the road in  a low path in one direction and in  a high path in the other direction so that the trigger device will trigger on both high and low ground clearance vehicles. 
     
     
       13. An integrated optical  emissions sensor for sensing a gas mixture composition of an exhaust plume of a motor vehicle travelling along a road , comprising:
 a single  console that is positioned at one side of the road  a detection space;  
 a vehicle detector in said console for sensing an oncoming  a vehicle and computing its acceleration;  
 a source in said console for radiating a beam of light along a path across the road  such that the beam passes through the exhaust plume of a passing  the vehicle and otherwise passes through ambient air;  
 a reflector that is positioned on the other side of the road  detection space such that the beam reflects off of the reflector and back to the console;  
 a receiver in said console sampling radiation levels at a plurality of predetermined wavelengths from the beam;  
 a data processing computer in said console for computing a gas mixture composition from the sensed  sampled radiation levels in accordance with stored calibration curves;  
 a canister in said console for emitting a puff of calibration gas in the path of the beam between the source and the receiver to recompute  compute the calibration curves;  
 a trigger device in said console that produces a trigger signal when a  the vehicle passes through the beam causing the data processing computer to record the gas mixture composition of the vehicle's exhaust plume for a period of time, said data processing computer disabling the recordation of the composition of the vehicle's exhaust plume when the acceleration exceeds a threshold ; and  
 a vehicle identification device in said console that responds to the trigger signal by recording a vehicle identification for the passing  vehicle.  
 
     
     
       14. The unmanned optical  emissions sensor of  claim 13 , wherein the vehicle identification device comprises an automated license plate reader (ALPR) that reads the vehicle's license at an angle of at least 20 degrees and said vehicle detector senses the oncoming vehicle at an angle of at least 20 degrees to maintain a vehicle throughput . 
     
     
       15. The unmanned optical  emissions sensor of  claim 13 , wherein one of said source and said receiver is positioned above the other so that the beam traverses the road  detection space in a low path in one direction and in a high path in the other direction so that the trigger device will trigger on both high and low ground clearance vehicles . 
     
     
       16. The unmanned optical  emissions sensor of  claim 13 , wherein the vehicle detector compute's  computes the vehicle's speed and computes a time-to-trigger range from the vehicle's measured speed and acceleration, said data processing computer disabling the recordation  a recording of the gas mixture composition of the vehicle's exhaust plume when triggering  the triggering signal occurs outside the time-to-trigger range. 
     
     
       17. The unmanned optical  emissions sensor of  claim 13 , wherein said calibration gas has a known reference composition of gas which absorbs radiation at the predetermined wavelengths, further comprising an automated control computer that
 a) calibrates the data processing computer by directing the canister to emit a puff of calibration gas, whereby the data processing computer recomputes  computes the calibration curves in accordance with the known reference composition;  
 b) verifies the calibration by directing the canister to emit a puff of calibration gas, whereby the data processing computer computes a test composition from the radiation levels and accepts the calibration when the test composition is close enough to the known reference composition and otherwise rejects the calibration and initiates recalibration  a new calibration; and  
 c) monitors the gas mixture composition of the ambient air to control recalibration  calibration of the data processing computer.  
 
     
     
       18. A remote emissions sensing system sensing gas mixture compositions of exhaust plumes for motor vehicles traveling along a network of roads, comprising:
 a plurality of unmanned integrated optical  emissions sensors positioned at different places in the network on a side of the road, each emissions sensor comprising: 
 a console;  
 a vehicle detector in said console for sensing an oncoming  a vehicle and computing its acceleration;  
 a source in said console for radiating a beam of light along a path across the road such that the beam passes through the exhaust plume of a passing  the vehicle and otherwise passes through ambient air;  
 a reflector that is positioned on the other side of the road such that the beam reflects off of the reflector and back to the console;  
 a receiver in said console that samples radiation levels at a plurality of predetermined wavelengths from the beam;  
 a data processing computer in said console for computing a gas mixture composition from the sensed  sampled radiation levels in accordance with stored calibration curves;  
 a canister in said console for emitting a puff of calibration gas in the path of the beam between the source and the receiver, said calibration gas having a known reference composition of gas which absorbs radiation at the predetermined wavelengths;  
 a trigger device in said console that produces a trigger signal when a  the vehicle passes through the beam causing the data processing computer to record the gas mixture composition of the vehicle's exhaust plume for a period of time, said data processing computer invalidating the recordation of the composition of the vehicle's exhaust plume when the acceleration exceeds a threshold ;  
 an automated control computer that 
 a) calibrates the data processing computer by directing the canister to emit a puff of calibration gas, whereby the data processing computer recomputes  computes the calibration curves in accordance with the known reference composition;  
 b) verifies the calibration by directing the canister to emit a puff of calibration gas, whereby the data processing computer computes a test composition from the radiation levels and accepts the calibration when the test composition is close enough to the known reference composition and otherwise rejects the calibration and initiates recalibration  a new calibration; and  
 c) monitors the gas mixture composition of the ambient air to control recalibration  calibration of the data processing computer; and  
 
 a vehicle identification device in said console that responds to the trigger signal by recording a vehicle identification for the passing  vehicle;  
 
 a manned  control center; and  
 a communications channel for communication between the emissions sensors and the manned  control center, said emissions sensors responding to repeated calibration rejections by transmitting a help message to the manned  control center, which in turn responds by performing diagnostics to determine a cause for the calibration rejection and then either remedy  remedies the cause remotely or dispatch  dispatches a technician to remedy the cause on site.  
 
     
     
       19. The unmanned optical emissions sensor  system of  claim 18 , wherein the vehicle detector compute's  of the emissions sensors computes the vehicle's speed and computes a time-to-trigger range from the vehicle's measured speed and acceleration, said data processing computer disabling the recordation  a recording of the gas mixture composition of the vehicle's exhaust plume when triggering  the trigger signal occurs outside the time-to-trigger range. 
     
     
       20. The unmanned optical emissions sensor  system of  claim 18 , wherein the vehicle identification device of the emissions sensors comprises an automated license plate reader (ALPR) that reads the vehicle's license at an angle of at least 20 degrees and said vehicle detector senses the oncoming vehicle at an angle of at least 20 degrees to maintain a vehicle throughput . 
     
     
       21. The unmanned optical emissions sensor  system of  claim 18 , wherein one of said source and said receiver of said emission sensors is positioned above the other so that the beam traverses the road in a low path in one direction and in a high path in the other direction so that the trigger device will trigger on both high and low ground clearance vehicles .