The Stability of Self-Propelled Sprayers According to the ISO 16231 Standardized Procedure

Abstract

Tractor rollover and agricultural machinery stability are subjects of interest both to manufacturers and researchers. Agricultural machines often work on rough terrain and sloping ground so instability and rollover events can easily occur. For agricultural tractors the solution adopted at international level was to provide them with Roll-Over Protective Structures (ROPS) to minimize risks for the driver in a rollover event. ROPSs are designed to absorb and sustain values of energy and forces established by the normalized OECD procedure. In the standardized tests it is necessary to evaluate the deformation of the ROPS because a clearance zone has to be maintained for the driver. Self-propelled sprayers currently have to comply with the EC 2006/42 Directive requirements and if recognized as being at risk of potential rollover a protective measure for the driver has to be defined by the manufacturer. The object of this evaluation was to assess the stability of self-propelled sprayers designed for arable crops according to the procedure in the ISO 16231-1/2 standard and evidence critical points in the provisions of the standard procedure. The standard defines a method to measure the Static Overturning Angle (SOA) of agricultural machines to be compared to a Required Static Stability Angle (RSSA) representing the limit for evaluating ROPS fitment on the machine. The measured angles allow it to be understood if such machines require ROPS installation. The stability angles measured were much higher than the required static stability angles so the rollover risk assessment produced a low risk for the sprayers and a ROPS protection was not needed.