In heavy quarry vehicles, tires represent a considerable investment. Consequently, it is crucial to be able to know the changes in their wear. A tool accomplishing such a task would be a powerful instrument to evaluate investment costs.
Dumpers (see picture) are quarry vehicles known for their impressive size (up to 7 meters high). The most significant cost, regardless of the vehicle itself, is the budget allocated to tire maintenance (for instance, a Liebherr T282B tire (4 meters, 5 tons) is about €30,000). It is the reason why pneumatic suppliers keep this aspect of their products in mind to satisfy their customers.
Acsystème has developed tools (with Matlab, Static Toolbox and Signal Processing toolbox) to process and analyse measurements in order to quantify and qualify tire wear. The two most significant quantities are pneumatic drift and slip. One of the tool’s main purposes is to reconstitute those quantities for each wheel.
The software “cleans” raw signals coming from different sensors: pressure, distance, acceleration, GPS and temperature, then it analyses and processes them to determine other quantities like wheel speed, steering angle, tire slipping and drifting, or even trajectory if there is no GPS data. In order to do that, we use mathematical methods like Kalman filtering, time/frequency filtering methods… Moreover, the tool needs to process a substantial amount of data: hundreds of signals measured over several days, meaning gigabytes of information, involving a particular formatting for algorithm.
By Gilles Gonon, PhD in Computer Science, signal processing expert