Variable valve lift diagnostic techniques based on camshaft speed
US9175582B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 23, 2014 |
| Grant date | Nov 3, 2015 |
| Priority date | — |
| Expiry date | Jul 23, 2034 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
An engine system and method for variable valve lift (VVL) diagnostic techniques are provided. In one exemplary implementation, the techniques include receiving, at a controller, a camshaft position signal indicative of detected edges of teeth of a camshaft toothed member that is coupled to a camshaft of an engine. The camshaft is configured to actuate a VVL system, which is configured to control a lift of a valve of the engine. The techniques also include calculating, at the controller, a camshaft speed signal indicative of a rotational speed of the camshaft based on the camshaft position signal. A valve stuck index (VSI) value is then calculated, at the controller, based on the camshaft speed signal. The techniques also include determining, at the controller, whether the valve is stuck based on a comparison of the VSI value to a predetermined threshold.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.