Robotic lawnmowers are big business at the moment, with the market set to be worth $2 billion by 2021. Europe accounts for more than 60% of the market share of robotic lawnmowers, with the USA coming in second. They are great for time-poor homeowners and people who have several properties (such as holiday rentals or second homes) who want to cut down on the maintenance costs for gardens that are not used very often. Although they are still relatively expensive compared to manual or self-propelled lawnmowers, they are proving popular with people who want to cut down the time they spend mowing and use that time for something more enjoyable.
Thank you for reading this post, don't forget to subscribe!Robotic lawnmowers do take some time to set up, and rely on the Hall Effect to keep them within the designated mowing area. A guide wire is staked into the lawn at the edges, through which a small current is passed. Although the current is not strong enough to cause a shock to people or pets, it is strong enough for the sensors on the mower to detect; they use that feedback to ensure they stay within the perimeter. This same guide wire allows the mower to return to its charging station when the battery starts to get low.
Using Hall Effect sensors means the robotic mower can operate even in the dark, and they are very quiet compared to a traditional electric or petrol powered lawnmower – making about as much noise as an air conditioner. The robots can be set to mow at certain times only, so if the garden is frequently in use during the day (especially over school holidays) then the lawnmower can be set to run early in the morning, or overnight. This means there is no disruption, no danger of children being injured by the lawnmower and the garden can be kept neat and tidy with minimal human intervention.
Although robotic lawnmowers use sensors to keep them within the confines of the area to be mown, there are still some areas where sensors can be used to make the mowers more efficient in their mowing capabilities. Currently, robotic lawnmowers go in a random pattern, often going over the same patches several times while others only get one pass. They also cannot detect when grass is brown and needs a little more length to stay healthy. They are able to detect the presence of an obstacle, so will turn around and go in a different direction when faced with lawn furniture, toys and other items commonly found in the garden, but there is still some way to go before they can completely replace human intervention in lawn care.
If sensors can be fitted to ensure the mower cuts each section of the lawn at the same rate (i.e. not going over the same parts too often) this will lead to better overall mowing; although the fact that they go at different angles does help improve the health of the grass. Similarly, if sensors can be deployed to detect the colour of the grass and set to not mow anything that is dry, brown and in need of more length, this will prevent over-mowing of bare patches. Grass needs blade length to reduce evaporation from the soil, as well as to increase the surface area for photosynthesis, so it is vital not to mow too aggressively when the lawn needs time to grow. As the industry booms there are many opportunities for more efficient sensor use and the development of sensor technology to improve efficiency in automated equipment of this type.