Chassis design is very important to new car development as it ensures optimal driving characteristics. Choosing the right design parameters requires extensive testing. For example, wheel housing design must allow sufficient clearance for various types of tires and their particular movements, and each wheel must be monitored to see how it behaves under extreme driving conditions or on bad pavements. Past studies have relied on mechanical monitoring devices which are complex in handling and may influence the driving behavior.
For the measurement of wheel movements, one camera for each wheel is mounted so that the wheel as well as part of the surrounding fender is visible. Special optical targets applied to the fender define the vehicle coordinate system. A lightweight carbon fiber wheel adapter is fixed to the wheel.
The position of the camera does not have to be stable as WheelWatch recalculates its position continuously using the reference targets on the vehicle fender. The wheel movement measurements are always provided in the vehicle coordinate system. Movements of the camera or camera mount do not influence measurement results, making the system inherently more stable than competing systems.
The driver manually triggers the beginning and end of a measurement session. No other interaction with WheelWatch is required. The high-speed camera collects wheel measurements at a rate of up to 490 times per second.
The image processor analyzes the digital images in real time and passes the measurement values to the notebook computer. Wheel target positions and target trajectories are available shortly after the image acquisition. In addition, WheelWatch computes all six degrees of freedom of the wheel in the vehicle coordinate system.
WheelWatch - Non-Contact, High Speed monitoring of wheel motion