During vehicle development, exact information about engine-to-body clearance is necessary to ensure an optimal design of the available space. For example, the engine must not collide with other parts in the engine bay when the driver changes gear. Aicon's optical measuring system EngineWatch is designed to measure engine movements precisely and acquires engine movements in six degrees of freedom.
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 microseconds, which 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 on 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 such a way that the camera can focus in on all the targets at the same time. 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 images are analysed in the sensor. Thus only the digital data is transferred to the computer in real time, not the entire images. EngineWatch calculates the X, Y, Z positions of the measuring points, as well as 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 visualise the measured movements in a CAD system, the results can be exported to post-processing software via an interface.
