Roaming robots could zap weeds dead say scientists

Share this on social media:

Pesticides may not be needed for clearing weeds after the demonstration of a laser system that could be used by field roaming robots to kill individual plants.

An infrared CO2 laser with a wavelength of 10.6µm is fired at weeds that are identified by a stereo camera system, which also optimises the laser beam position. Researchers have determined how much energy is needed to destroy plants’ sensitive growth centres, known as meristems, making the method very efficient. The researchers expect that large fields could be swept by autonomous field robots that would identify weeds and laser them. Researchers know seedlings can be killed with 35 Joules.

Using image analysis techniques such as threshold level filtering and edge detection, the position of a plant’s leaves can help locate the meristem position. By using a galvanometer scanner with a flexible mirror system, the laser beam can be focused with high precision on the near-surface meristems. Under laboratory conditions, an accuracy of <±1mm could be achieved, and under greenhouse conditions, a laser on a rail carriage achieved accuracies of ±3.4mm. The use of a galvanometer scanner with a flexible mirror system also enables the laser to be moved quickly from plant to plant.

Funded by the German Research Foundation, the work is being carried out by Laser Zentrum Hannover and Leibniz Universität Hannover’s Biosystems and Horticultural Engineering faculty.

Recent News

16 December 2020

Recycleye’s vision system is capable of detecting and classifying items in waste streams, broken down by material, object and brand

10 December 2020

The sensor is based on a thin-film photodetector monolithically integrated on a custom Si-CMOS readout circuit

03 September 2020

Terahertz imaging company, Tihive, has been awarded €8.6m from the European Innovation Council's Accelerator programme to scale up its industrial inspection technology

19 May 2020

The National Institute of Standards and Technology and ASTM Committee E57 have released proceedings on a workshop to define the performance of 3D imaging systems for robots in manufacturing