Development of a Telerobotic Target-Specific Pesticide Applicator: An Intervention for Enhanced Safety and Efficiency

Abstract

Advances in computing and electronics are finding applications in agriculture. These facilitate the automation of farm operations performed manually under greenhouse structures. During chemical application, farm workers are exposed to toxic chemicals and experience fatigue and drudgery with traditional spraying equipment. The traditional application methods apply chemicals uniformly, without considering the spatial variability of the canopy, which adversely impacts the economy and environment. To mitigate these, a telerobotic target-specific pesticide applicator (robot) was designed and developed for real-time application of pesticides based on the presence and height of foliage. It consists of a prime mover, an ultrasonic sensor-based target-specific pesticide application system with electronic control for navigation and spraying systems. The robot is operated from outside the greenhouse by an operator sitting in a safe environment through real-time video. The percentage reduction in pesticide use during greenhouse field evaluation was 24.95% with activation compared to without the activation of sensors. The theoretical field capacity, effective field capacity, and field efficiency of the robot are 0.20 ha h⁻¹, 0.15 ha h⁻¹, and 75% respectively. The maximum range of wireless communication between the operator and the robot was 121 m. The root mean square error of deviation from a straight-line path was 55 mm. In the context of user interface design for human–robot interaction, two display devices (a dashboard display and a first-person view head-mounted display [HMD]) were evaluated, along with peripheral vision (single view and adjustable multiple views). Results showed that adjustable multiple views with the HMD demonstrated statistically significant improvements in effectiveness, efficiency, and system usability scores compared with single view and dashboard display. The potential dermal exposures of the operators with a rechargeable knapsack sprayer (RKP) and with a developed robot during spraying activity were 53.75 ± 0.99 mL h⁻¹ and zero, respectively. This means the developed robot eliminates exposure to the operator. The ergonomic parameters—heart rate, body part discomfort score, and overall discomfort score—using an RKP are 104.1 ± 6 beats min⁻¹, 27.3 ± 2.0, and 3.5 ± 0.2, respectively, while with the developed robot, they were 99 ± 4 beats min⁻¹, 12.1 ± 1.1, and 1.0 ± 0.5, respectively. The operating cost of the developed robot was 1.74 times higher than that of the RKP, but it offers a more precise pesticide application, reducing chemical wastage and environmental impact. The robot completes spraying on a 1500 m² greenhouse in 0.75 h compared with 4 h with a knapsack sprayer, reducing spraying time by 5.3 times and enhancing efficiency, cost savings, and operator well-being.