Mowing the lawn can be tedious, but that could change if an eco-friendly prototype robot is widely adopted.
U.S. students have created an autonomous machine that not only cuts grass in a specified area, but uses the waste cuttings to power itself – saving you both time and money.
The E-Mow is built upon the body of an electric toy car, but the clever vehicle is able to convert grass pellets into fuel, using a small biomass gasifier - a type of furnace that converts organic matter into gas.
HOW DOES E-MOW WORK?
- The machine trims grass using a low-power electrical bar cutter and collects the grass snippets, which are funnelled into a hot and pressurised area where they are turned into dry grass pellets.
- The dry squashed cuttings then pass into a small gasifier where they are converted to gas and this biomass fuel is then cooled, filtered and mixed with air so that it can be used to power the robotic lawnmower’s engine.
- The dried pellets can also be used for other applications such as heating or power generation.
Engineers from George Mason University, Washington D.C. believe their invention could revolutionise the garden chore and more importantly be used as an efficient way to create animal feed.
The machine trims grass using a low-power electrical bar cutter, unlike many mowers that use a rotating blade. This allows the mower to operate without the need to maintain the kinetic energy required in a rotary blade system.
It then collects the grass snippets, which are funnelled into an area where they are turned into dry grass pellets in a manner similar to a meat grinder except that higher pressures and temperatures are used, the engineers explained.
The machine trims grass using a low-power electrical bar cutter and collects the grass snippets, which are funnelled into a hot and pressurised area where they are turned into dry grass pellets
The dry squashed cuttings then pass into a collection bin where they are dried with hot air from the gasifier and are then converted into fuel gas in the gasifier itself.
This biomass fuel is then cooled, filtered and mixed with air so that it can be used to power the robotic lawnmower’s engine.
The dried pellets can also be used for other applications, such as livestock fodder and can be periodically off-loaded to a storage unit.
'The drone harvester processes biomass directly to product form in a single pass without human labour,' said Jason Force, Chief Design Engineer of the project.
He explained that conventional methods for deriving biomass pellets from grassy sources are
inefficient.
Multiple passes are required to harvest and raw biomass must then be trucked to a facility to process into products, but the new invention does all this in one step, he explained.
Users of the lawnmower will not have to push it around their garden, as the useful robot is autonomous thanks to onboard GPS and proximity sensors.
In the future they will be able to program the machine by selecting an area to mow using Google Maps – and tell the mower to avoid certain obstacles so flowerbeds are not cut down too.
The machine will also use its GPS system to watch out for roads and other boundaries, as well as to navigate itself efficiently around a garden.
Mr Force and his team are currently looking to raise investment to bring their lawnmower to market and there is no price for the machine yet.
'We will be designing and operating or own harvesting platforms to produce a range of pellet biomass products. Primary target markets are pellet fuel and livestock fodder.
'Future plans include both commercial and consumer turf-mowing units for sale and licensing pellet fuel system technology for uses in vehicles, heating, and plant power,' he said.
Mr Force also said that E-Mow harvesters 'represent a revolutionary micro-grid solution in developing countries.'
'We plan to use this technology to provide a breakthrough in producing pelletised biomass products,' he added.
The team plans on having a working fuel reactor integrated with an engine in order to demonstrate a complete fuel system by March.