Development and assessment of a novel single-drive variable angle spraying machine

Traditional sprayers are limited to applying spray mixture solely to the upper surfaces of crops. To overcome this limitation, a variable angle spraying machine (VASM) was designed using a linkage system. This machine enables the adjustment of both the spray position and angle through a single input signal, facilitating multi-directional spraying from the top to the bottom of crops. By utilizing ADAMS simulation, the relationship between input signal and output angle of spraying connecting rod was analyzed. The study employs a control variable experimental methodology alongside multiple comparison analysis to investigate various experimental factors, specifically nozzle sweep time (t), spray pump pressure (p), and distance from measurement position to surface (l). The average coverage rate observed in the top, side, and bottom orientations during actual operational conditions serves as the primary evaluation index for experimental analysis. The experimental results indicate that the VASM can achieve comprehensive spraying of crops, effectively covering both the leaf surface and the leaf underside. As the l value increases, the downward spray coverage rate (DSC) gradually rises, while the sideways spray coverage rate (SSC) gradually declines. The upward spray coverage rate (USC) initially decreases before increasing. It was observed that the DSC is lower than both the USC and the SSC due to the influence of gravity, particularly in the surface and middle layers of crops. The VASM can significantly enhance coverage of the underside and inner layers of crop leaves, thereby achieving the objectives of reducing pesticide waste and minimizing environmental pollution.