System and method for quantifying source and component emission rates from a body in a flow field
A system and method that remotely quantifies mass emission rates of emission material emitted from moving vehicles as they operate in real-time. Release locations of these emission materials may or may not coincide, and plumes generated from the releases may be spatially overlapping or distinct. The method can quantify both distance-based mass emission rates (grams/mile) and time-based emission rates (gram/hour). Exemplary approaches can be used to measure vehicle emissions as they move whether the emissions are released from the tailpipe or elsewhere on the vehicle and without touching the vehicle. The approaches might also be used in other situations where material is emitted from a body in a flow field, such as an aircraft or marine vessel moving through air, a stationary source in a wind field, or brake or tire wear particulate material of a heavy-duty truck driving on the road.
1. A system for quantifying an object's mass emissions, comprising:
a first sensor configured to measure a portion of a mass of an emitted emission material surrounding an object in motion relative to a surrounding medium;
a second sensor configured to estimate a first relative velocity of the object in motion with respect to the first sensor;
a third sensor configured to estimate a velocity of the surrounding medium;
a vortex shape calculation device configured to estimate a second relative velocity of the object in motion with respect to the surrounding medium based on the first relative velocity and the estimated velocity of the surrounding medium; and
an emission calculation device configured to determine the mass of the emitted emission materials surrounding the object per unit time or per unit distance travelled by the object based on the measured portion, the estimated first relative velocity and the estimated second relative velocity.
2. The system of claim 1 , wherein the motion of the object relative to the surrounding medium produces a vortex that temporarily stores the portion of the mass of the emitted emission materials.
3. The system of claim 2 , wherein the determined mass of one of the emitted emission materials per unit time is proportional to the first sensor measurement of the portion of the mass of the one emitted emission material in the vortex and inversely proportional to a vortex entrainment time.
4. The system of claim 3 , wherein the object has a dimension, and the vortex entrainment time is a function of at least one of the second relative velocity of the object in motion with respect to the surrounding medium, an estimated source location on the object, and the dimension of the object.
5. The system of claim 3 , wherein the determined mass of one of the emitted emission materials per unit distance is proportional to the determined mass of the one emitted emission material per unit time and inversely proportional to the first relative velocity of the object in motion.
6. The system of claim 1 , wherein the determined mass of the emitted emission materials surrounding the object per unit time or per unit distance travelled by the object enables real world profiling or characterizations of the emitted emission materials.
7. A system for quantifying an object's mass emissions, comprising
a sensor that measures one of spatial distributions and temporal distributions of a mass of a plurality of emitted emission materials surrounding an object in motion relative to a surrounding medium; and
an emission calculation device configured to combine the measured distributions of the plurality of emitted emission materials from the sensor,
wherein portions of the masses of the emitted emission materials have different source locations on the object, the emission calculation device further configured to determine a collective mass of the portions of masses of the emitted emission materials having the different source locations.
8. The system of claim 7 , wherein the emission calculation device is further configured to apply a blind source separation technique to combine the measurements of the plurality of emitted emission materials surrounding the object to produce separated patterns of the relative masses of the emitted emission materials.
9. The system of claim 8 , wherein the blind source separation technique includes an independent component analysis technique applied to at least two of the measurements of the plurality of emitted emission materials surrounding the object to produce a pattern of the relative masses of the emitted emission materials as an output.
10. The system of claim 8 , wherein the blind source separation technique is applied to at least two of the measurements of the plurality of emitted emission materials surrounding the object to produce at least two patterns of the relative masses of the emitted emission materials as outputs of the technique.
11. The system of claim 8 , wherein the blind source separation technique specifies an association between the separated patterns of the relative masses of the emitted emission materials.
12. The system of claim 8 , further comprising applying an estimation technique to combine the measurements of the one of the spatial distributions and the temporal distributions of the masses of the plurality of emitted emission materials surrounding the object with a plurality of separated patterns of the relative masses of the emitted emission materials to determine portions of the masses of the emitted emission materials having different source locations.
13. The system of claim 12 , further comprising:
a second sensor configured to estimate a first relative velocity of the object in motion with respect to the first sensor;
a third sensor configured to estimate a velocity of the surrounding medium;
a vortex shape calculation device configured to estimate a second relative velocity of the object in motion with respect to the surrounding medium based on the first relative velocity and the estimated velocity of the surrounding medium; and
the emission calculation device further configured to determine the mass of the emitted emission materials surrounding the object per unit time or per unit distance travelled by the object based on the measured mass, the first relative velocity and the estimated second relative velocity.
14. The system of claim 13 , wherein the motion of the object relative to the surrounding medium produces a vortex that temporarily stores a portion of the mass of the emitted emission materials.
15. The system of claim 14 , wherein the determined mass of one of the emitted emission materials per unit time is proportional to the first sensor measurement of a portion of the measured mass of the one emitted emission material in the vortex and inversely proportional to a vortex entrainment time.
16. The system of claim 15 , wherein the object has a dimension, and the vortex entrainment time is a function of at least one of the second relative velocity of the object in motion with respect to the surrounding medium, an estimated source location on the object, and the dimension of the object.
17. The system of claim 15 , wherein the determined mass of one of the emitted emission materials per unit distance is proportional to the determined mass of the one emitted emission material per unit time and inversely proportional to the first relative velocity of the object in motion.
18. The system of claim 7 , wherein the determined collective mass of the portions of masses of the emitted emission materials having the different source locations enables real world profiling or characterizations of the emitted emission materials.
19. A method for quantifying an object's mass emissions, comprising:
measuring a portion of a mass of an emitted emission material surrounding an object in motion relative to a surrounding medium via a first sensor;
estimating a first relative velocity of the object in motion with respect to the first sensor via a second sensor;
a third sensor configured to estimating a velocity of the surrounding medium via a third sensor;
estimating a second relative velocity of the object in motion with respect to the surrounding medium based on the first relative velocity and the estimated velocity of the surrounding medium via a vortex shape calculation device; and
determining the mass of the emitted emission materials surrounding the object per unit time or per unit distance travelled by the object via an emission calculation device based on the measured portion, the estimated first relative velocity and the estimated second relative velocity.
20. The method of claim 19 , further comprising:
measuring one of spatial distributions and temporal distributions of the mass of a plurality of the emitted emission materials surrounding the object in motion relative to the surrounding medium via the first sensor;
aggregating the measured distributions of each of the emitted emission materials via an emission calculation device,
wherein portions of the masses of the emitted emission materials have different source locations on the object; and
determining a collective mass of the portions of masses of the emitted emission materials having the different source locations via the emission calculation device.