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Robotic mowers, a growing market

Lawn mower manufacturers have an ongoing commitment to research and development to bring to the market mowers with increasingly improved performance as regards power, precision and accuracy in cutting. The number of them producing robotic mowers has increased in recent years and the market is continuing to grow. An example is France where the sales of these mowers virtually doubled in 2014

by Pietro Piccarolo
May - June 2015 | Back


The selection of species for creating lawns has become so advanced that it is possible to lay out a lawn which performs well under all conditions. A leading problem has always been shade tolerance and this becomes especially difficult for a lawn which includes  considerable shrubbery and a large numbers of trees. Other than the reduction of sunlight and less circulation of air, this means that following rain the rainwater can stagnate and the humidity can damage the vegetation. Thanks to years of research there are now seed varieties and mixes capable of adapting to shady conditions and even heavy shade. Another situation to cope with is a dry environment or areas with little water availability. Also in this case there is a selection of grasses which adapt to these conditions. For lawns open to the public the aesthetic features is not overly important but to ensure that the lawn performs well the selection of the variety and mix must be done carefully before planting. A totally different issue is the prestige lawn for which research has led to the production of varieties and seed mixes for high quality ornamental covers. Varieties and seed mixes are available for all situations.

Along with this progress is the advance in innovative lawn mower technologies. Manufacturers are committed to research and development to bring to the market mowers with increasingly greater performance, motorization improvements, precision and accuracy of cut and produce systems for comfortable and ergonomic driving. These developments have also been driven by European Union legislation requiring more ecologically friendly engines as regards exhaust emissions and decibel levels for reduced noise pollution.

In coping with this progress for bringing in general as well as technological improvements, the end-user is not always up to the job of choosing the right mower. The most noteworthy shortcomings in this connection involve: a mower too small for the size of the lawn frequency of mowing generally insufficient by cutting the grass when it is too high. The well-known basic principle is to remove no more than one-third of the height of the grass so when this is not applied the lawn loses quality. improper maintenance of the mower which leads to worsening the quality of mowing.

The results could be that the commitment to work might discourage proper management of the law and especially mowing which, on the other hand, requires continuous attention and timely operations. Autonomous robot mowers which are silent and do not pollute can be the right solution for the correct maintenance of lawns.


A growing market

The users of lawn mowers can be divided into two categories, those who require a low price machine without considering longevity or the quality of work as opposed to demanding users as regards performance and the quality of work who are willing to invest to a substantial degree. In the latter category are those who go for robotic mowers.

Robots for mowing lawns form a market which is growing. In France, for example, the number of this type of mower sold more or less doubled in 2014. From September 2014 to August 2014, 6,400 of these units were sold for an 83% increase over the previous period for a value of more than € 12 million, equal to a gain of 67%. In terms of the numbers, this value was far ahead of push mowers as well as ride-on mowers at 12% and 4% respectively.

The number of manufacturers of robotic mowers is on the increase because the brand names most accredited on the market already, including important Italian companies, have recently been added to by new players in such emerging countries as China. At present, the offers of these robots come to about eighty models. The differentian among these models is strong and this means it will be necessary for the buyer to gather precise information on characteristics, quality and the reliability of the mower. Overall, this is a market which can meet all requirements with models suitable for areas ranging from 400 m² up to 30,000 m².


The types

In general terms, the initial classification of the various models can be made according to the lawn areas to be mowed to distinguish them in four categories: from 400 to 1,000 m²; 1,000 to 3,000 m²; 3,000 to 6,000 m² ; greater than 6,000 m². The characteristics shared are mulch cutting and power provided by lithium-ion batteries with capacities which range from 5 Ah for the first class to 30-60 Ah for the latter. Also size in relation to work capacity is diversified: mowers under 10 kg go into the first category and those at 20 to 50 kg move to the fourth. According to the model, the time allowed for mowing before recharging the batteries moves from the most frequent 1-2 hours to more than 8 hours. For these robots, the most widespread solution is automatic recharging when battery power sinks below a predetermined level to automatically send the mow to the charging station. The forward speed is 1.5-2 km/hr with some models working at greater speeds. These robots are virtually silent, producing noise levels below 80 dB(A). The electric motors powering these mowers have power of values in the area of 150-200 W for the smallest models.

The cutting blade can be a 4 or 8 point star or a disc with projecting blades around the edge of the disc. The rotation regime is about 3000 rpm.

The width of the cut is between 20 and 35 cm. The length of the work, according to the model, extends from 20-25 cm with a single blade to 120 cm with multiple blades, up to 5. In this case, the cutting deck is tilts for allowing the mower to better follow the profile of the lawn. The height of the cut can be regulated from 20 to 60 mm.

Most robotic mowers require fencing the area to be mowed with electrified perimeter wiring. The most advanced models can be remotely controlled with a touchscreen, Bluetooth or GPD and are equipped with a compass, a smartphone app and a system for programming the cutting area without the use of the perimeter wiring. Traction can be provided by 2WD, 4WD or tracked.

The slopes that can be handled by these robots are generally 30-35° and 20° close to the perimeter wire. Large wheel and tracked models can work on slopes of up to 45°.

Other than a PIN for security, the sensors with which these mowers are equipped determine the technological level of the machine. Aside from obstacle sensors, the most sophisticated models are fitted with sensors for detecting rain and capable of memorizing the lawn area already mowed to avoid damage due to rain or a repetition of mowing these areas. Sensors can also detect the height of the grass and can be set to control the variation of blade rpm to increase rotation in high grass. 

Robotic mowers can provide the option of programming cutting by prior setting of the course to follow rather than a random normal course and can signal malfunction on a cellphone via an SMS or a remote control tablet.

The body of these robots are made of different materials. For the technologically advanced models with high work capacities the body work can be in light and resistant carbon fiber.

Faced with this vast range of offers the purchaser must base choice not only on the size of the lawn, the point of departure, but evaluate the mower’s construction and functional features as well as price and the technical assistance to be guaranteed.  


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