Air/fuel ratio controller and control method
US9206755B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 27, 2012 |
| Grant date | Dec 8, 2015 |
| Priority date | — |
| Expiry date | Sep 6, 2034 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D41/1479
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
An air/fuel ratio controller (6) and a method that uses an upstream control loop to maintain a given optimum air/fuel ratio (λopt), whereas the optimum air/fuel ratio (λopt) is determined in the controller (6) in an downstream control loop by adding incremental offset (Δλ) to the air/fuel ratio set-point (λSP) of an upstream control loop while monitoring a NOx sensor (10) output. The air/fuel ratio set-points (λSP) at two turning points (SP1, SP2) in the NOx sensor (10) output are used to calculate a new optimum air/fuel ratio set-point (λopt) as mean value of the air/fuel ratio set-points (λSP1, λSP2) at the turning points (SP1, SP2).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.