{"id":41852,"date":"2022-10-11T15:15:38","date_gmt":"2022-10-11T19:15:38","guid":{"rendered":"https:\/\/blogs.sw.siemens.com\/simcenter\/?p=41852"},"modified":"2026-03-26T06:27:21","modified_gmt":"2026-03-26T10:27:21","slug":"dem-lawn-mower","status":"publish","type":"post","link":"https:\/\/blogs.sw.siemens.com\/simcenter\/dem-lawn-mower\/","title":{"rendered":"Robots? Not in my backyard!"},"content":{"rendered":"\n

When the time came to recycle my old gasoline-powered lawn mower, I decided it was time to switch to something more environmentally friendly. Although fascinated by the capabilities of robotic mowers, I rejected this option for three reasons:<\/p>\n\n\n\n

  1. My lawn is littered with fallen twigs, pinecones, and leaves in autumn, which creates challenges for robotic mowers. <\/li>
  2. The higher cost of the robotic mower compared to other battery-powered lawn mowers. <\/li>
  3. I like pushing the lawn mower, and I would miss the activity if I switched to a robotic one.<\/li><\/ol>\n\n\n\n

    After careful consideration of the landscape of my yard, my budget, and the type of lawn mower I was looking for, I settled on a traditional manual-push lawn mower with a long-lasting accumulator.<\/p>\n\n\n\n

    But as I was comparing robotic and manual lawn mowers, I was struck by how much grass-cutting technology has changed over the last century alone. The technological advancements in the last ten years are owed in large part to the exponential growth in computer modelling and the digital twin methods. I hope the trend continues so the robotic lawn mower, more capable and affordable, will be my top choice next time I upgrade.<\/p>\n\n\n\n

    The demand for fast and accurate DEM simulation<\/h2>\n\n\n\n

    But my lawn – in all honesty – is just a playground. And cutting grass may be considered as cosmetics. However, on a global scale, efficiently cutting organic material is critical to feed billions of people. Today, agricultural equipment manufacturers need to make better and faster design and manufacturing decisions in order to meet the demands of feeding the world sustainably.<\/p>\n\n\n\n

    \"\"
    CAMPO VERDE, MATO GROSSO, BRAZIL – MARCH 02, 2008: Mass soybean harvesting at a farm in Campo Verde<\/figcaption><\/figure>\n\n\n\n

    But, before we go big, let me start in my own backyard. So, how do you optimize the grass-cutting process without endless trial and error (I only have one lawn and one new mower)? <\/p>\n\n\n\n

    The key is DEM simulation. <\/p>\n\n\n\n

    Grass and any kind of crop can be treated as particles connected to the ground. Each grass blade is modelled separately using the Discrete Element Method (DEM simulation). They yield when applied defined stress \u2013 which results from the impact of a rigid body moving; in this case, the mower blade. After being cut off, the grass blades. or any other organic fibre, behave like bulk material \u2013 another typical use case for DEM simulation! That way, engineers can even optimize the mower blade to counter the wear of millions of grass blades \u2013 or to withstand tons of pinecones lying on the lawn.<\/p>\n\n\n\n

    To overcome the challenge of designing better agricultural and process engineering products in shorter development cycles several capabilities are required for improving computational time and accuracy of particle simulations. Engineers need to leverage the following features to improve the speed of DEM simulation while maintaining sufficient accuracy:<\/p>\n\n\n\n