Whole Body Vibration Transmission to the Human Rachis in Agricultural Tractors

Abstract

The seat has always been an element to intervene on, to improve the vibrational comfort on agricultural tractors. There are several methodologies for assessing the level of exposure to Whole Body Vibration (WBV) such as ISO 2631, ISO 5008 (in an agricultural wheeled tractor) and evaluation of the seat efficiency to reduce the vibration. In this paper, the transmission of vibrations along the rachis was measured in one driver of agricultural tractor to evaluate whether the only measurements carried out according to ISO 2631 were adequate to describe the effective level of exposure. An acquisition system based on ADXL345 MEMS accelerometers and ESP32 microcontroller was suitably developed to acquire the vibrations in several points along the spinal column in addition to those indicated by the reference standards. Specifically, five MEMS accelerometers were placed at the seat attachment point, the seat-buttock interface, and along the drivers’ column. The tests were performed on tractor used on paved road to different velocity. The results indicated that assessing the level of exposure to Whole Body Vibration (WBV) based on the ISO 2631 standard may not consistently capture all the stresses experienced by the entire spine. Indeed, in certain instances, the highest accelerations were observed in the cervical area and the head. Despite not being a formal measurement system, low-cost systems like the one developed, after appropriate verifications, can serve as a viable means to monitor the vibration exposure levels of agricultural tractor drivers. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.