Measure Engine Movements

September 18th, 2008

Aicon EngineWatch measures engine movements, and the movements of other relevant parts in the engine bay, in six degrees of freedom (6-DOF). It can make measuerments while the vehicle is on a test stand or while it is in motion. It reports the position and orientation of the measured points with absolute values in the vehicle coordinate system.

The optical measuring system EngineWatch works on a non-contact base i.e. without a mechanical connection between sensor and engine block. This, the company claims, allows the system to make reliable measurements under extreme dynamic conditions. The system can make up to 490 measurements per second, and measuring data can be recorded for an unlimited period of time.

EngineWatch is built around the high speed camera TraceCam F. The camera consists of a high resolution CMOS sensor, an integrated high performance flash, and an image analysis processor. TraceCam F features extremely short shutter speeds of just a few micro-seconds that are necessary for long-duration tests. It also ensures the system is robust and stable over time.

Mounted on a fixture, the TraceCam F camera directly focuses the engine block. The measuring principle is based on the detection of relative movements of two solid bodies. Therefore reference targets are placed on the engine block and on the car body in a way that the camera will focus all targets at the same time. Setup and calibration of the system take less than 30 minutes. The position of the camera to the engine block does not need to be stable as EngineWatch recalculates its position continuously using the reference targets. Hence, camera movements cannot influence the measuring results.

The measuring images are analysed in the sensor. Thus only the digital data are transferred to the notebook computer in real time, not the entire images. EngineWatch calculates the positions of the measuring points in X, Y, Z, and the rotation angle (alpha, beta, gamma) as absolute values in the vehicle coordinate system. For the presentation of the results, a path-time-diagram is created showing the X, Y, Z movements in the vehicle coordinate system. In order to visualize the measured movements in a CAD system, the measuring results can be exported to post-processing software via an interface.

Entry Filed under: Environmental/Durability Test, Powertrain Test