Type-Approval and Qualification Testing of Air Braking Systems of Agricultural Trailers Under Stationary Conditions

For road safety reasons, agricultural vehicle braking systems must comply with the approval requirements of EU Delegated Regulation 2015/68, which are evaluated during stationary and road testing conditions. For the stationary tests, an algorithm and procedures are developed to test the air braking systems of towed vehicles, including checking for tightness, pushrod strokes of brake chambers (adjustment), response times and the capacity of the compressed air reservoirs. Testing of a single-axle trailer braking system was carried out using a computer-controlled diagnostic device incorporating a simulator of the tractor’s braking system developed by the authors. The trailer test results obtained confirmed the usefulness of the methodology developed and showed high accuracy and repeatability of measurements. The results of this work can be used not only by type-approval bodies, but also by manufacturers of trailers and towed agricultural machinery for quality control or product qualification tests.