Electric device with linear motor for robot-weeding

Abstract

The goal of decreasing herbicide usage has so far focused on reducing the herbicide dosage or replacing chemical weed control by hoeing and harrowing. The conventional weed control strategy is to apply the same dose rate of herbicide or the same intensity of physical treatments to the whole field. This strategy may be changed in the coming years, because several investigations have shown that site specific weed management can reduce herbicide usage significantly. One of the promising technologies within site specific weed management is robotic weeding. Today the most challenging problem is still to remove weeds within the rows and close to crop plants. So far, no commercial selective mechanical methods have been developed for the intra-row or close-to-crop areas, thus, 10% to 20% of a field has to be controlled by band spraying or manual weeding. Novel mechanical or chemical weeding methods therefore have to be developed in order to achieve further reduction in the herbicide usage. A new idea is to combine computer vision and seed mapping to obtain improved overall accuracy, reliability and efficiency in geo-referencing the crop and weed seedlings. Unfortunately, oscillating and rotating tillage devices cannot be used in the close-to-crop area due to the high risk of root or leaf damage of crop seedlings. Therefore, the close-to-crop area has to be treated with highly accurate operating tools. The most appropriate tool should avoid root damage and therefore operate above-ground (not tilling). Promising tools could be very small spinning blades, a laser or a picking device. An alternative method to physical weeding in the close-to-crop area could be the micro-spray system that deposits micro-volumes of a herbicide on single weed plants. In this paper, a design of highly accurate operating robot arm based on linear motor is presented.