Abstract: The apparatus is of the kind comprising detectors (21,23) of deviation of vehicle positional parameters from a path which is fixed in advance providing electrical data which actuates a control device (14) connected to a steering device (7) for steering the steered wheels (2) of the vehicle. The problem to be solved is to avoid the influence of shocks and vibrations and reduce the interventions of the driver. To this end, the detectors comprise a travelled distance detector (21) and a detector (23) of the steered angle of a steered wheel that provide data to a comparator (28) which is also connected to a memory (30) storing positional data relating to a path to be followed, including a manually set device (43) for introducing the desired spacing between parallel passes.The invention is especially applicable to agricultural machines.

Abstract: A method and device are disclosed for calibrating a regulated flow spraying apparatus of the type including a source of spraying fluid under pressure, and spray nozzles, the flow rate of the spray nozzles being regulated by varying the pressure of the liquid delivered thereto, the regulation being controlled as a function of at least one external parameter and a calibration parameter. Fluid from the source is conveyed to a calibration circuit comprising a flow rate sensor and at least one calibration nozzle. The flow rate and the pressure of the fluid are measured in the claibration circuit. The calibration parameter is calculated from the measured values of the flow rate and pressure.