SBIR Phase I: Microwave Sensing for Monitoring and Controlling Diesel Particulate Filter Operation

This Small Business Innovation Research Phase 1 project will investigate the feasibility of using microwaves to measure the amount, type, and distribution of material collected on filters. Filter Sensing Technologies, Inc. (FST) has targeted diesel particulate filters (DPF) as a promising application. Nearly all 2007 and newer diesel engines are equipped with DPFs to meet increasingly stringent emissions limits. The DPF is a porous ceramic substrate mounted in the exhaust, and traps up to 99% of all soot emissions. Accurate monitoring of material accumulation in the DPF is critical to ensure proper operation, minimize the associated fuel economy penalty, and avoid filter malfunctions. Current DPF monitoring systems measure the pressure drop across the filter together with sophisticated predictive soot emission algorithms. These systems are inaccurate, costly, and complex, resulting in inefficient engine operation. FST will develop an innovative microwave-based soot sensor to monitor DPF loading directly, more accurately, and with increased functionality than the current state-of-the art. The research plan will investigate the ability of this system to simultaneously detect soot and ash in the DPF and the spatial distribution of the material. Phase 1 will result in a prototype system to undergo additional field testing and development in Phase 2. The broader impacts of this research address a significant unmet need to improve filter monitoring and control. Measurement error in the current systems is reported between 30% - 50%, and increases when alternative fuels are used. More accurate DPF monitoring provides annual fuel and maintenance cost savings to the end-user between $750 and $1,350 for a typical heavy-duty truck. OEM's benefit from lower system costs, reduced warranty claims, and improved engine and DPF operation. The US DPF sensor market will generate $45 M in annual revenues in 2008, growing to $90 M by 2012. The European market is five times as large. FST's patent pending RF-sensing technologies offer improved performance and increased functionality at less than half the cost of current systems. This sensor greatly simplifies the use of DPFs in OEM and retrofit applications, significantly reducing harmful soot and greenhouse gas emissions. It increases compatibility with alternative fuels and provides fuel economy benefits to the end-user. This technology is not limited to emission control applications, but a wide range of filtration applications where monitoring the amount, type, and location of materials accumulated on filters is critical. This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).