Development of a novel mechatronic system for mechanical weed ...

Materials and methods
response speeds associated with automatic calibration type sensors. The
response time can reach 80 µs in mode for fast detection.
The amplifier supports four different detection modes: standard with normal or
increased hysteresis and differentiation method detecting upper or lower edge
of the received light change. The light sensitivity can be calibrated for two digital
channels separately. The sensor and the amplifier are illustrated in the Figure
4.2.
Height detection range of the LV-H47 sensor head is between 55 mm and 85
mm and the corresponding covered width is between 20 mm and 25 mm. As a
light source, a visible red semiconductor laser with 650 nm wavelength is
installed in this head with pulse duration of 3.5 ms.
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Figure 4.2 a) Laser sensor head LV – H47 with appropriate LV-
21AP amplifier b) Sensor head in working position with
illustrated optimal detection range and corresponding
width of the area covered by laser
RGB sensor and the laser sensor were mounted on a joint carrier behind one
another on a 50 mm distance as shown in Figure 4.3. The sensor carrier was
mounted on a toolframe allowing accurate following of the soil surface to keep
the constant distance between the sensors and the soil surface.