Asperge-oogstrobot - Saxion | Hogeschool Saxion

White asparagus are one of the most popular vegetables in the Netherlands and in a large part of Europe. Asparagus grow on sandy soils, which mainly occur in Noord-Brabant, Limburg and Overijssel. Every spring there is a harvest time of about 10 weeks when asparagus can be harvested. To date, however, this has mainly been manual work, which makes the asparagus harvest labor-intensive.

Asparagus are white as long as it is under the ground and turns green or purple when it rises above the ground. Some asparagus varieties are grown above the ground and are therefore eaten green or purple, but the white variety becomes very hard and stringy if it grows too far, so this is very undesirable. An asparagus is ideally cut just before it rises above the ground. This provides the best quality - and therefore the best price for the farmer. However, this means that a row has to be “visited” by the cutters approximately every two days, to see which asparagus are ready for cutting.

project approach

The asparagus plant is a perennial plant (8-10 years) that is planted in special beds, to ensure that they can be harvested properly, but also to ensure that the temperature in the bed can be regulated. This is done with a foil that is colored white on one side and black on the other. If the bed needs to be warmed up (beginning of the season), the black side will be up and if growth needs to be slowed down (mid season), the white side will be up.

Due to this method of harvesting, it has so far proven to be very difficult to make a good automation step that can reduce the cost price while the quality of the harvested asparagus remains at least the same. In recent years, a number of products have been developed, both fully autonomous robots that turned out to be far too slow, and drawn systems that significantly lower the quality of the harvested asparagus.

project goal

The desired overall project goal is to demonstrate that the use of robotic harvesting machines is technically and economically feasible for asparagus cultivation. To this end, the aim within the scope of this project is to design and build a proof of concept (working model) of the positioning subsystem of the asparagus growing robot. This positioning system is a moving platform with a mechanism capable of reaching the asparagus in the bed.