Design and experiment of variable rate orchard sprayer based on laser scanning sensor

Abstract

During different growth periods, canopy size and density in orchards are variable, which need application conditions (flow rate and air flow) to be adjusted to match the canopy's characteristics. In order to improve orchard sprayer's automatic operating performance, an automatic variable-rate orchard sprayer (VARS) fixed with 40 electromagnetic valves and 8 brushless fans was developed based on the canopy's spatial dimensions. Each solenoid valve and brushless motor can be individually adjusted in real-time through pulse width modulation (PWM) signals emitted by a control system to adjust each nozzle's spout and fan rotation speed. A high-precision laser scanning sensor (light detecting and ranging, LIDAR) was adopted as the detector to measure the canopy volume using the variable rate algorithm principle. Field experiments were conducted in an apple orchard, and conventional air blast sprayer (CABS) and directed air-jet sprayer (DAJS) were tested as a comparison. Results showed that on average, 46% less spraying solution was applied compared to conventional applications, while penetration rate was similar to DAJS. Normalized deposition in the canopy with variable application was higher than that of conventional applications, indicating that electronic sprayers are more efficient than conventional sprayers. It was also observed that VARS could significantly reduce off-target loss. The field experiment showed that the newly developed variable-rate sprayer can greatly reduce pesticide use and protect the environment for the orchard fruit production, and also provide a reference for design and performance optimization for plant protection machinery.

Field assessment of a newly‐designed pneumatic spout to contain spray drift in vineyards: evaluation of canopy distribution and off‐target losses

“…In light of the need described earlier, pesticide application equipment design in recent years has been active. While many developments have focused on sensing module-based precision spraying 15 to maximize treatment efficacy and minimize the risks of pesticide off-target losses, [16][17][18][19][20][21][22][23][24][25][26][27][28][29] very few advances have been made in pesticide application equipment characterized by pneumatic atomization. Despite a reputation for collateral risk from drift and spray losses caused by the fine droplets generated by these sprayers, they remain widely used in the most important wine 30,31 and table grape-producing 32 vineyard areas around the world.…”

Mini-review of application of IoT technology in monitoring agricultural products quality and safety

“…Sensor technology is widely used in the environmental protection and monitoring, disease prevention and treatment, and agricultural products monitoring [44][45][46][47][48] . In recent years, it has been also widely used in agricultural products processing and detecting, greenhouse environment monitoring, fruit and vegetable preservation, precision agriculture and grain storage [49][50][51] . Now, with the rapid development of the IoT technology, sensor technology requirements are increasing.…”

Analyzing and overcoming the effects of GNSS error on LiDAR based orchard parameters estimation

“…Among the new sensing technologies, LiDAR (light detection and range) sensors are used mainly for geometric characterization of groves (Rilling et al 2017;Trochta et al 2017;Rosell and Sanz 2012;Li et al 2018). From the geometric parameters of plants, the crown surface area and volume are of special interest since both combine the width, height, geometric shape and the structure of trees (Auat Cheein et al 2015).…”

“…To do so, we implement previously published techniques (Pfeiffer et al 2018;Trochta et al 2017;Li et al 2018) and evaluate their sensitivity to changes in the error of the GNSS antenna, for two cases: (i) GNSS as a solo localization system and (ii) GNSS with scan matching as localization system.…”