Tag Archives: electrical field

1088–1098 V. Osadcuks and A. PeckaV. Osadcuks and A. Pecka
Electrical field based detection of fruits and vegetables for robotized horticulture
Abstract |
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Electrical field based detection of fruits and vegetables for robotized horticulture

V. Osadcuks* and A. PeckaV. Osadcuks* and A. Pecka

Latvia University of Agriculture, Faculty of Engineering, Department of Energetics, Cakstes blvd. 5, LV-3001 Jelgava, Latvia; *Correspondence: vtl@tvnet.lv

Abstract:

In this research authors study possibilities of using transmitting-type electric field based sensors for recognition of fruits and vegetables. The main idea is to detect distortions of electrical field between electrodes of sensors by measuring capacitance changes for these electrodes. Electrical field is strongly affected by relative permittivity of medium, which is several times larger for fruits and vegetables consisting mainly of water than for surrounding air, leaves and other low-mass non-conductive objects. This could help to develop electrical field sensing device with number of electrodes for detection of fruits or vegetables and determining their position thus serving as additional sensor in multi sensor system with optical camera or as stand alone device. The research covers both theoretical aspect of proposed approach and experimental evaluation of prototype device based on mixed signal controller MGC3130 originally intended for electrical field based gesture sensing periphery for consumer electronics. Main results show that in worst condition when an electrode is fully covered with a physical model of leaf 43% of signal value in comparison to sensor output without obstacle is still usable. Thus this type of sensors potentially can be an integral part of complex fruit or vegetable recognition system in robotized horticulture applications. 

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485–494, J. Lev and M. Wohlmuthová
Segmented capacitance sensor and first tests of inverse problem solution
Abstract |

Segmented capacitance sensor and first tests of inverse problem solution

J. Lev¹* and M. Wohlmuthová²

¹Czech University of Life Sciences Prague, Faculty of Engineering, Department of
Physics, Kamýcká 129, CZ 165 21 Prague 6, Czech Republic
²Czech University of Life Sciences Prague, Faculty of Engineering, Department of
Mathematics, Kamýcká 129, CZ 16

Abstract:

 The segmented capacitance sensor (SCS) is developed for the purpose of material throughput measurement. SCS can be used in precise agriculture (e.g. yield maps creation) or for controlling of mass flow in stationary lines. This sensor is a compromise between simple capacitance throughput sensor which has been developed at the Department of Agricultural Machines Faculty of Engineering of Czech University of Life Sciences Prague and electrical capacitance tomography sensor. The SCS consists of the bottom plate (bottom electrode) and several upper electrodes which are placed parallel above the bottom plate. The upper electrodes are sometimes called segments of an upper plate. The bottom plate is undivided and it is assumed that it will be stored under measured material. During the measurement process the electric capacitance between one upper electrode and the bottom plate is measured every time. The sensor should be able to determine the distribution of material between upper electrodes and the bottom plate. This paper presents the algorithm of inverse problem solution. The algorithm was tested in two phases. The testing during the first phase was done via mathematical model which was presented in previous papers. Results show that the presented algorithm can be used for the inverse problem solution. For the purpose of the second testing phase a simple SCS was made. Electrical capacitances were measured by precise LCR meter. In the second testing phase, the inverse problem algorithm was tested using the actually measured data.

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