Technical Features connection of external three-dimensional acceleration sensor 1 extra channel, e.g. for driving torque CAN channels, e.g. for the speed 50 Hz antialiasing filter 1000 samples/sec per channel 5 frequency bands 1 real and 15 vitual Rainflow channels 2D Time at Level Counting (TaL) 9 - 30 VDC power supply small sized (11cm x 9cm x 6cm) optional: wireless data transfer unlimited measuring time

Various driving conditions result in typical wheel loads, stresses and cutting loads at different areas of the vehicle. The time history of such values cannot be calculated from the acceleration of the vehicles chassis directly. Instead a correlation between the acceleration of the chassis and the damage evolution caused by such loads, stresses and cutting loads especially wheel forces can be derived and determined by the Durability Transfer Concept.

The combined data analyser/data logger OCEAN ONE implements this new Durability Transfer Concept to efficiently perform long-term measurements on vehicles under test or in customers use. It acquires 3-axis acceleration data and analysis the data according to a unique combination of frequency analysis and the Rainflow algorithm. Together with the Durability Transfer Concept it enables the reconstruction of the progressive deterioration caused at the whole vehicle.

The OCEAN ONE System

The OCEAN ONE system is a dedicated hardware and software system for implementing the Durability Transfer Concept. The Durability Transfer Concept is a method of measuring the strain developed in various locations of the vehicle due to acceleration or deceleration. It provides the possibility of long term measurement of forces on the under-carriage and to store and analyse the measured data. The OCEAN (Online Counting and Evaluation System) recorder from SWIFT provides the online system for the process. The data logger, which has been specifically developed for this purpose, performs online data reduction using virtual channels and a Rainflow Matrix over virtually unlimited durations. The data are analysed to identify wheel loads, stresses and cutting loads at various locations of the vehicle. Three of the available four analogue channels are used for connecting an external 3-D accelerometer. The fourth channel can be used for further measurements, e.g. torque. The OCEAN recorder also provides a CAN interface allowing further channels, for example engine speed, to be recorded. The recorder includes a hardware anti-aliasing filter of greater than 50 Hz, and is capable of measuring 1000 samples per sec per channel in 5 frequency bands and to resolve the data into 15 virtual Rainflow channels. In addition, it is also possible to perform a 2-D Time at Level counting. After acquisition, the data (either in the form of a Rainflow Matrix or as a time-stamped series of loads) are processed with the vehicle transfer function to identify any damage and the associated causing events. This allows preventative maintenance of the vehicle to be scheduled and optimised based not only on the mileage of the vehicle but also on its actual stress history. The operating voltage is between 9 – 30 VDC, which can normally be extracted from the on-board power supply. The small dimensions of 11 cm x 9 cm x 6 cm and the option of transferring data via mobile link allows the deployment in the smallest or most un-accessible of vehicles. The efforts and costs related to long-term measurements can be considerably reduced as data from only one 3-D accelerometer are necessary and these can be further reduced in volume on-line by the SWIFT OCEAN recorder, while retaining sufficient useful information to determine the complex loads and strains of the whole vehicle.

OCEAN ONE (Online Counting Evaluation and ANalysis) OCEAN ONE is a joint venture of SWIFT and Prof. Dr.-Ing. Andreas Rupp (FH Kempten) to implement the Durability Transfer Concept