Full repository of all technical papers and presentations on the subject of radio frequency sensing hosted on various publications sites like SAE, ASME, CLEERS, Nanoparticals.ch, and Energy.gov. Our low-power radio frequency (RF) sensors transmit and receive RF signals through the filter. Soot and ash accumulation levels, as well as filter failure symptoms, can be directly measured by the change in response of the RF signal. The sensor provides additional flexibility to engine and aftertreatment system designers when attempting to meet increasingly stringent emissions regulations and fuel efficiency standards.
Technical Papers
2019-Direct Measurement of Ammonia Storage on Passive SCR Systems for Lean Gasoline NOx Reduction Using Radio Frequency Sensing
https://www.sae.org/publications/technical-papers/content/2019-01-0739/
SAE Technical Paper 2019-01-0739
Authors: Sappok, A., Ragaller, P., Guarino, A., Mandelbaum, J. et al.
Lean gasoline engine operation provides clear efficiency benefits relative to conventional stoichiometric combustion approaches. One of the key hurdles to the widespread, practical implementation of lean gasoline combustion remains the challenge of lean NOx control. One of the potential approaches for controlling NOx emission from lean gasoline engines is the so-called passive selective catalytic reduction (SCR) system. In such systems…Continue on SAE website
2018–Continuous Particulate Filter State of Health
Monitoring Using Radio Frequency Sensing
https://www.sae.org/publications/technical-papers/content/2018-01-1260/
SAE Technical Paper 2018-01-1260, 2018.
Authors: Sappok, A., Ragaller, P., Herman, A., Bromberg, L., et al.
Reliable means for on-board detection of particulate filter failures or malfunctions are needed to meet diagnostics (OBD) requirements. Detecting these failures, which result in tailpipe particulate matter (PM) emissions exceeding the OBD limit, over all operating conditions is challenging. Current approaches employ differential pressure sensors and downstream PM sensors, in combination with particulate filter and engine-out soot models. These conventional monitors typically operate over narrowly-defined time windows and do not provide a direct measure of the filter’s state of health. In contrast, radio frequency (RF) sensors, which transmit a wireless signal through the filter substrate provide a direct means for interrogating the condition of the filter itself…Continue reading on the SAE website…
2018–Developing Design Guidelines for an SCR Assembly Equipped
for RF Sensing of NH3 Loading
https://www.sae.org/publications/technical-papers/content/2018-01-1266/
SAE Technical Paper 2018-01-1266, 2018
Authors: Bromberg, L., Harris, T., Sappok, A., Guarino, A. et al.,
With future high-capacity CuZ catalyst designs, it is likely that the accuracy of this NH3 loading estimate will become limiting for NOx conversion efficiency. Therefore, a direct measurement of NH3 loading is needed; RF sensing enables this. Relative to RF sensing of soot in a DPF (which is in commercial production), RF sensing of NH3 adsorbed on CuZ is more challenging. Therefore, more attention must be paid to the “microwave resonance cavity” created within the SCR assembly… Continue reading on the SAE website…
2017–On-Board Particulate Filter Failure Prevention and Failure Diagnostics using Radio Frequency Sensing
https://www.sae.org/publications/technical-papers/content/2017-01-0950/
SAE 2017-01-0950, 2017.
Authors: Sappok, A., Ragaller, P., Bromberg, L., Herman, A., Prikhodko, V., Parks, J., and Storey, J.
The increasing use of diesel and gasoline particulate filters requires advanced on-board diagnostics (OBD) to prevent and detect filter failures and malfunctions. Early detection of upstream (engine-out) malfunctions is paramount to preventing irreversible damage to downstream aftertreatment system components…Continue reading on the SAE website…
2016–Real-Time Engine and Aftertreatment System Control Using Fast Response Particulate Filter Sensors
https://www.sae.org/publications/technical-papers/content/2016-01-0918/
SAE 2016-01-0918, 2016.
Authors: Sappok, A., Ragaller, P., Bromberg, L., Prikhodko, V., Storey, J., and Parks, J.
Radio frequency (RF)-based sensors provide a direct measure of the particulate filter loading state. In contrast to particulate matter (PM) sensors, which monitor the concentration of PM in the exhaust gas stream for on-board diagnostics purposes, RF sensors have historically been applied to monitor and control the particulate filter regeneration process…Continue reading on the SAE website…
2016–Particulate Filter Soot Load Measurements using Radio Frequency Sensors and Potential for Improved Filter Management
https://www.sae.org/publications/technical-papers/content/2016-01-0943/
SAE 2016-01-0943, 2016.
Authors: Ragaller, P., Sappok, A., Bromberg, L., Gunasekaran, N., Warkins, J., and Wilhelm, R.
Efficient aftertreatment management requires accurate sensing of both particulate filter soot and ash levels for optimized feedback control. Currently a combination of pressure drop measurements and predictive models are used to indirectly estimate the loading state of the filter…Continue reading on the SAE website…
2015–Diesel Particulate Filter-Related Fuel Efficiency Improvements using Biodiesel Blends in Conjunction with Advanced Aftertreatment Sensing and Controls
http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=2481726
ASME ICEF 2015-1146, 2015.
Authors: Sappok, A., Prikhodko, V., Ragaller, P., Bromberg, L., Storey, J., and Parks II, J.
This study investigated the use of neat biodiesel, as well as blends, with a light-duty diesel engine equipped with a catalyzed diesel particulate filter (DPF) and radio frequency particulate filter sensor. The results show a reduction in engine-out PM emissions with increasing biodiesel blend levels and a corresponding increase in the duration between DPF regenerations…Continue reading on the ASME website…
2015–Advanced RF Particulate Filter Sensing and Controls for Efficient Aftertreatment Management and Reduced Fuel Consumption
https://www.sae.org/publications/technical-papers/content/2015-01-0996/
SAE 2015-01-0996, 2015.
Authors: Nanjundaswamy, H., Nagaraju, V., Wu, Y., Koehler, E., Sappok, A., Ragaller, P., and Bromberg, L.
Although designed for the purpose of reducing engine-out Particulate Matter (PM) emissions to meet or exceed mandated emissions regulations, the particulate filter also incurs a fuel economy penalty. This fuel penalty is due to the increased exhaust flow restriction attributed to the PM accumulated in the filter, in addition to fuel consumed for active regeneration…Continue reading on the SAE website…
2014–Vibration-Induced Ash Removal from Diesel Particulate Filters
http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=2022897
ASME Technical Paper, ICEF2014-5570, 2014.
Authors: Sappok, A., Constanzo, V., Bromberg, L., Waldo, C., and Salsgiver, R.
Ceramic, honeycomb-type diesel particulate filters (DPF) are commonly used in a wide range of on- and off-road diesel-powered vehicles and equipment to reduce particulate matter (PM) emissions to mandated levels. While the majority of the trapped PM can be removed from the filter through regeneration, incombustible ash builds up in the filter over time…Continue reading on the ASME website…
2014–Radio Frequency Diesel Particulate Filter Soot and Ash Level Sensors: Enabling Adaptive Controls for Heavy-Duty Diesel Applications
https://www.sae.org/publications/technical-papers/content/2014-01-2349/
SAE Int. J. Commer. Veh. 7(2):468-477, 2014.
Authors: Sappok, A. and Bromberg, L.
Diesel Particulate Filters (DPF) are a key component in many on- and off-road aftertreatment systems to meet increasingly stringent particle emissions limits. Efficient thermal management and regeneration control is critical for reliable and cost-effective operation of the combined engine and aftertreatment system…Continue reading on the SAE website…
2013–Development of Radio Frequency Sensing fro In-Situ Diesel Particulate Filter State Monitoring and Aftertreatment System Control
http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=1837776
ASME ICEF2013-19199, ASME ICED Fall Technical Conference, April 2013.
Authors: Sappok, A., Bromberg, L.
Diesel particulate filters (DPF) have seen widespread application in the United States and Europe to meet stringent diesel particulate matter (PM) emissions regulations. Now commonplace on most on-road diesel vehicles, DPFs are being increasingly applied to diesel-powered off-road equipment as additional regulations are phased in…Continue reading on the ASME website…
2010–Loading and Regeneration Analysis of a Diesel Particulate Filter with a Radio Frequency-Based Sensor
https://www.sae.org/publications/technical-papers/content/2010-01-2126/
Society of Automotive Engineers, SAE 2010-01-2126, 2010.
Authors: Sappok, A., Bromberg, L., Parks, J., and Prikhodko, V.
Accurate knowledge of diesel particulate filter (DPF) particulate matter (PM) loading is critical for robust and efficient operation of the combined engine-exhaust aftertreatment system. Furthermore, upcoming on-board diagnostics regulations require on-board technologies to evaluate the status of the DPF…Continue reading on the SAE website…
Presentations
ETH Nanoparticle Conference:
In-Use Particulate Filter State of Health Monitoring: Prognostics and Diagnostics using Radio Frequency Sensing
Author: Alexander Sappok
PM Sensing Approaches, RF Sensor Description and Operation Examples: Applications for Filter Control Case Studies: Particulate Filter Diagnostics
Real-Time Particulate Filter Soot and Ash Measurements via Radio Frequency Sensing
Author: Alexander Sappok
Determination of Filter/Catalyst State
CLEERS:
Real-Time Catalyst Monitoring and Diagnostics using Radio Frequency Sensors
Authors: Paul Ragaller, Alexander Sappok, Leslie Bromberg,
Real-Time Particulate Filter Soot and Ash Measurements, Optimized Control, and Diagnostics via Radio Frequency Sensing
Authors: Alexander Sappok, Paul Ragaller, Leslie Bromberg
United States Dept. of Energy Annual Merit Review Presentations:
2017–Improved Fuel Efficiency through Adaptive Radio Frequency Controls and Diagnostics for Advanced Catalyst Systems
DOE Merit Review, Washington DC June 2017
Authors: Alexander Sappok (PI), Paul Ragaller, Leslie Bromberg
2016–Improved Fuel Efficiency through Adaptive Radio Frequency Controls and Diagnostics for Advanced Catalyst Systems
DOE Merit Review, Washington DC June 2016
Authors: Alexander Sappok (PI), Paul Ragaller, Leslie Bromberg
2015–Development of Radio Frequency Diesel Particulate Filter Sensor and Controls for Advanced Low-Pressure Drop Systems to Reduce Engine Fuel Consumption (06B)
DOE Merit Review, Washington DC June 2015
Authors: Alexander Sappok (PI), Paul Ragaller, Leslie Bromberg