Pesticides Research, 97 – Autonomous Weeder for Christmas Trees – Basic Development and Tests

Autonomous Weeder for Christmas Trees – Basic Development and Tests

10 Perspectives

10.1 Scientific perspectives
10.2 Practical perspectives

The work reported has mainly dealt with development of the concept and the basic functions of the vehicle. Much more work is needed to develop sufficient reliability and safety for real autonomous operation. Still, the work has shown promising results and generated ideas for further work.

10.1 Scientific perspectives

To work reliably and safe enough for practical use the ACW should be able to react sensibly to occurring faults and abnormal conditions inside the machine itself, in relation to the working tool, and in relation to the surroundings. To obtain these abilities it should be able to percept occurrences of such conditions and to behave in an appropriate way.

Better perception reliability can be achieved through sensor redundancy, which means that a parameter or condition should be measured in more than one way. But this requirement does not necessarily mean that all sensors should be duplicated. Many of the measured parameters are mutual related. This means that a systematic comparison of already measured parameter may be sufficient to detect errors not measured directly. One example is that vehicle movement measured by the GPS is related to engine speed, gear ratio, and wheel slip. If for instance the engine is running, and the vehicle not moving something is wrong. A few other examples are discussed in section 8.3.3.

An important future task would therefore be to make a systematic analysis of this type of sensor redundancy to obtain the required level of perception quality and certainty with a minimum number and costs of sensors. This would help vehicle operational reliability and safety. It would also reduce costs.

10.2 Practical perspectives

The used method of individual tree mapping would allow implementation of several new tree specific management practices, e.g. tree growth regulation, tree shaping, monitoring of pests, deceases and nutrient deficiencies, applications of pesticides and fertilisers according to needs, and selective harvest. Also automatic monitoring of quality factors of trees may be used for marketing and sale purposes.

Apart from Christmas trees the ACW could be applied in other cultures like fruit trees, berry bushes, wine and ornamental trees. Down scaled to smaller row distance and plants it may be applied in a range of row crops like vegetables, maize and sugar beets – perhaps with a different weed control tool.

Also the developed autonomous vehicle would be suitable for simpler jobs like grass cutting, which would improve its utilisation and economy. All these potential market areas may contribute to commercial interest and cost reduction because of larger production numbers.