[Agricultural Machinery Spotlighted at KIEMSTA] Hanseo Precision’s unmanned autonomous SS sprayer ‘A-Sprayer’ continues spraying even when GPS is lost

The speed sprayer (SS sprayer) used for orchard pest control is essential equipment for farms, but it is also dangerous. In orchards with many slopes, the driver’s seat is exposed as the machine moves, leading to repeated rollover and fall accidents. Operators are also exposed to pesticide spray throughout the job. According to the Rural Development Administration, over the past three years (2022–2024), there were 3,257 agricultural machinery accidents, resulting in 186 deaths and 1,775 injuries.

At the 2026 Korea International Exhibition of Machinery, Equipment, Science and Technology for Agriculture (KIEMSTA), held at EXCO in Daegu from the 4th to the 7th, an SS sprayer that moves through orchards on its own without a human on board attracted the attention of fruit growers. It is an unmanned autonomous SS sprayer released under the autonomous-driving brand ‘A-Sprayer’ by Hanseo Precision Co., Ltd., which has made SS sprayers for decades. After beginning sales in September, the company showcased two models at this exhibition—the 600-liter-class ‘HAS-600MH’ and the 1,000-liter-class ‘HAS-1000ED’—signaling full-scale sales.
 

Development began with farm safety accidents and pesticide exposure

Jang Se-in, head of Hanseo Precision’s Autonomous Driving Research Center, cited farm safety as the reason development began. “While selling SS sprayers, we saw operators become ill from pesticide exposure, and above all there were quite a few safety accidents and fatal accidents,” Jang said. “So I thought we should start with autonomous driving first.” He added that the company prepared early because agricultural machinery also has to keep pace with the trend toward smart farming.

Farmers in the field think the same way. Jung Young-cheol, an apple grower in Yeongcheon, North Gyeongsang Province, who introduced the machine in September, said pesticide inhalation was why an unmanned SS sprayer was needed. “With conventional SS sprayers, even if you wear protective clothing and a mask, in practice you cannot avoid inhaling pesticides, especially in summer or when the wind blows,” Jung said. “There are also many cases where people die in SS sprayer accidents.”

Hanseo Precision did not retrofit an existing SS sprayer; it designed the machine from scratch on the premise of unmanned operation. The work took about seven years. The final hurdle was overcome with patented technology transferred from the Department of Agricultural Engineering at the National Institute of Agricultural Sciences under the Rural Development Administration. It is a technology that applies steering angle, and by integrating it the company completed the core functions in the first half of this year. “Reading from the steering angle was the starting point for everything,” Jang explained. “From a technology developer’s perspective, getting over the last hill is the hardest part, and we got over it with RDA technology.”
 

Continues working even when the GPS signal is lost

The function Jang presents as the biggest differentiator is that the machine does not stop even if the GPS signal is lost. According to Jang, most GPS-based autonomous agricultural machines currently stop in place if the signal is interrupted even briefly. If it is a tractor with a person on board, the driver can respond immediately. But in many cases, people leave an unmanned sprayer to do the job and go off to do other work.

“If you send out a machine claiming it is autonomous but it keeps stopping, farmers become anxious and have to keep watching it, and then it is not fully autonomous,” Jang said. “If the machine is sitting still while spraying pesticides before dawn, time passes without the treatment being done, which is a serious problem.” He added, “We had built the machine long ago, but until this technology was integrated, we could not confidently release it. Now that we have solved the problem, we presented and launched it at this exhibition.”

The specific implementation method was not disclosed. However, the company said it fused several technologies and introduces it as an ‘RTK GPS-based 3MAP route-driving method.’ Jang explained that because work can continue without depending on GPS signals, it can also be used inside vinyl greenhouses.

Jung also cited this as the biggest advantage. There are places in his orchard where mobile phone reception is poor. Even so, he said that in actual use, work was not interrupted. Jung said he also looked at two unmanned sprayers from other companies at the fair, and that this machine was “excellent in those aspects.”

Automatically slows on downhill and turning sections

The operating method is route-learning based. When a farmer drives through the orchard once at the beginning and enters the route, the machine turns it into a map and follows it. “After the route is entered, there may be a difference of about 15 to 20 cm during the second verification run, but once it is corrected, it does not deviate from that route,” Jang said. The 600MH can store 20 routes and the 1000ED can store 30, so they can be used while moving among multiple orchards.

Jang described the machine as a “thinking machine.” This means it follows the map while making its own judgments according to the terrain. The spraying speed on flat ground is 1.9 to 2.1 km/h, but on downhill slopes it automatically slows to about 1.3 km/h. “Unmanned vehicles gain speed on downhill sections because of gravity, and if they are not slowed this much, momentum builds up and becomes dangerous,” Jang said. It also reduces speed on turning sections compared with straight sections. In areas without trees, it stops spraying and sprays only where trees are present. The spray position is also controlled by dividing it into left, center and right. When the spray liquid runs low, the machine returns to the starting point; after the liquid is replenished, it returns to where it stopped and continues the job.

Jung said, “Even when a person drives an SS sprayer, they slow down on turns. If you give the command while entering the route, it slows down and turns on its own in turning sections and goes at normal speed on straight sections, which was good.” He said it was not difficult to use even the first time.

Collision prevention was deliberately designed simply. If obstacle-detection sensors are installed, malfunctions occur frequently in orchard environments with lots of grass or on turns close to trees, causing the work to stop often. Instead, the company chose a method in which the machine stops immediately if the front part hits something and is pushed back. “It is an advanced machine, but collision prevention is analog,” Jang explained. “If a sensor catches on grass and malfunctions, the work itself becomes difficult.”
 

Field-proven for 3 years in grapes and 4 years in apples…farmers feel pesticide use cut by one-fourth

Field verification was conducted in grape orchards for three years and apple orchards for four years in Gyeongsan and Yeongcheon, North Gyeongsang Province. Tests were repeated on slopes, rough terrain and slippery pear orchards after rain. “If you do not do that much field testing, the risk after sales is too high,” Jang said. “We could not sell it until we thought it was complete.”
Jung’s orchard was also one of the verification sites. The company repeatedly test-operated the machine at Jung’s farm and fixed problems when they appeared, while Jung also directly conveyed points to improve from a farmer’s perspective. “At first, the atmosphere was probably that everyone wondered, ‘Will that really work?’” Jung said. “Watching the development process built trust, and now I felt it was good enough, so I signed a contract.” Even so, when he first entrusted the work to it, he could not fully relax, and after the purchase he ran it three or four times while watching from beside it.

In addition to freedom from pesticide exposure and reduced work burden, pesticide cost savings are also expected. The 600MH can work for 7 to 8 hours on a single charge. “A person cannot work for seven hours while being exposed to pesticides,” Jang said. Because it sprays a fixed amount at a constant speed and turns off spraying in areas without trees, total pesticide use decreases. “We can confidently say it is about 30% less than the existing method,” Jang said. He explained that it is not the number of spraying operations that is reduced, but the amount sprayed per operation. Jung also said that compared with spraying the same orchard with a conventional SS sprayer, it seems to save about one-fourth.

Because it is an autonomous model, the price is higher than that of a conventional SS sprayer of the same capacity. It is registered as a model eligible for government support. “The initial amount is burdensome, but after using it for about two years, even after depreciation, you can save a lot through labor and pesticide reductions,” Jang said.

600-liter rear-riding type and 1,000-liter integrated-engine type

The HAS-600MH (overall length 3,100 mm, weight 1,387 kg) uses a lithium iron phosphate battery (capacity 120 Ah) and a 2.2 kW motor for driving, while a Honda GX690 gasoline engine (13.7 kW output based on company specifications) handles blowing. A self-charging hybrid type can be selected. With a ‘rear-riding’ structure in which a person rides at the back, it can be driven directly when moving between orchards.

The HAS-1000ED (overall length 3,300 mm, weight 1,600 kg) is an integrated-engine type in which a single diesel engine (40.6 kW) handles both driving and blowing. It has four-wheel steering, four-wheel drive and an HST drive unit, and the company introduces it as Korea’s first 1,000-liter-class wheeled autonomous SS sprayer. Both models support manual operation via touchscreen and remote control. Routes can be adjusted on a PC, and when connected by Bluetooth, the machine’s location and work status can be checked.
 

The next task is precision spraying with physical AI

Jang assessed that autonomous SS sprayers for orchards have essentially reached the completion stage. His view is that adding more functions only increases price and the risk of breakdowns. “Our company’s concept is to operate with the smallest amount of the latest technology,” Jang said, emphasizing that it is “a simple but thinking machine.” As the next step, the company is researching precision spraying based on physical AI and related technologies.

Expectations in the field are focused on wider adoption. “This machine is necessary and made for farmers,” Jung said, adding that he expects the price to fall as more farms purchase it. He stressed that it is “a path to freedom from pesticides and safety accidents.”