Improved Mass Air Flow Sensor for Automotive Applications
Competition in the automotive industry has increased the need for superior engines. Electronic monitoring and microsecond control systems enable a level of sophistication and performance that has previously not been available. Accurate input to engine control systems has become a priority. Combustion air flow control is as important as control of the air-fuel ratio, where the measurement of this air flow is commonly done with a mass air flow sensor (MAFS).
Description of Technology
The technology is an air flow sensor for automotive engines. In particular, it can measure air mass flow when the flow is unsteady and has direction reversals. The sensor, mounted in a conduit, has two cone-shaped nozzles, each containing a hot wire probe. One of the nozzles faces forward and the other backward to respectively measure air flow in the normal and reversed directions. The additional sensor information on reversed air flow makes possible improved engine control systems in the future. Such a sensor can promote enhanced control of air-fuel ratios in the combustion chamber, with particular significance for: (1) premix gasoline engines operating above mid-throttle position; (2) diesel engines especially during transients (e.g. accelerations); (3) stratified charge spark ignition engines; and (4) engines with variable cam timing.
- Improved engine performance: Additional information on reversed air flow volumes is made available to future engine control software, with resulting improved engine performance.
- Superior engine control: This technology capability has natural applications in "next generation" engine control systems by providing intrinsically superior engine control.
- Potential use in other airflow systems: Such systems may include medical respirators and controlled breathing apparatus, where there is two-way air flow.
- Advantages of hot-wire mass air flow sensors: This includes fast response times, low airflow restriction, no moving parts, and improved durability.
Improved automotive air measurement sensors. There are also potential applications in other air flow systems, e.g. respirators for medical applications, controlled breathing apparatus and non-automotive combustion systems such as aircraft engines and energy systems.
1 U.S. patent issued: 7,555,945
Ahmed Naguib, Harold Schock, Antonius Aditjandra, Thomas Stuecken, Barry Trosin, Edward Timm
For Information, Contact:
Michigan State University