Picking pecks of peppers by robot

A boxy yellow robot rolls through rows of yellow pepper plants... it pauses when it detects a ripe pepper and then with a quick move of a blade, it cuts the stem and grabs the fruit with a palm-like catcher. The harvesting arm, called a gripper or manipulator, went through many integrations, including pulling, cutting and dropping the fruit into a bag, as well as other harvesting variations, to devise the most efficient and safest model.

SWEEPER, a result of a collaboration between Israeli, Dutch, Swedish and Belgian scientists, is a complex piece of equipment aimed to help farmers and agricultural workers in the harvesting process. With some modifications, robots similar to SWEEPER can be taught to gather apples or tomatoes and the like.

You would think it straightforward to have a robot harvest peppers wouldn’t you? After all Peter Piper could pick pecks of pickled peppers quite easily. But teaching a robot to pick peppers isn’t for the faint-hearted.

To teach SWEEPER to identify peppers and harvest them gently without damaging them or the plant they grew on required artificial intelligence and machine learning. Unlike humans, who can discern the colourful fruit among the green foliage quite easily, even in somewhat dim lighting, robots have a much more difficult time doing so. SWEEPER was shown thousands of pictures of peppers just to be able to identify the vegetables. It took the team about three and a half years to arrive at the current SWEEPER model, which has just passed its greenhouse test.

Some argue that these robots may cause job losses for agricultural workers, but the reality is more complex. As the climate changes, heat waves intensify and humidity increases, working long hours in the field is becoming more unhealthy, and in some cases dangerous, for humans. Even greenhouse conditions, tailored to the plants’ needs, may in some cases be too hot or humid for people.

According to reported data from 1992 to 2006, 68 crop workers in the US died from exposure to environmental heat. In essence, toiling in the fields is a hard job that will become even more difficult as climate change progresses, so humans will likely have to rely on robots to do some farming. “We don’t expect these robots to replace people,” said Prof Yael Edan, head of BGU’s ABC Robotics Initiative, whose team worked on the SWEEPER robot. “We think they would help with tasks that are difficult for people to do.”

The BGU team is developing other agricultural innovations too. One of them is a smart pesticide sprayer that would calculate the exact amount of chemicals needed to keep plants healthy. Rather than spraying abundantly, the machine would target the chemicals, thereby reducing people’s exposure to them.