Agriculture Reference
In-Depth Information
2.5.4 R
OBOT
C
OMBINE
H
ARVESTER
A developed robot combine harvester in NARO, Japan is shown in Figure 2.16. The
base machine was a 26-kW combine harvester (HC350; ISEKI Ltd.). An RTK-GPS
and a GPS compass (V100; Hemisphere) substituting for an IMU are used as navi-
gation sensors. The GPS compass gives absolute heading angle with an accuracy
of 0.3°. Figure 2.17 shows the schematic diagram of the system. Each component
such as the RTK-GPS, the GPS compass, and various actuators are connected to the
ECU, and the PC communicates with all ECUs through the CAN bus. The PC sends
control signals to a Program Logic Controller (PLC) connecting to a controller in the
combine harvester to follow the predetermined path based on the information from
the navigation sensors. The HSTs for changing speed and steering are controlled by
an electrical cylinder and an electrical motor, respectively. The robot has general
functions on a combine harvester such as a speed control, a header height control,
and an auto level system.
Figure 2.18 shows a trajectory of the robot combine harvester on a wheat field.
The field size was 30,000 m
2
, and the work speed was 0.6 m/s. The first three round
paths from the outside of the field were harvested by human drive, and the rest of
the ield was square-harvested with cross land by the robot. A lateral error of the
robot operation was about 7.1 cm. This error was acceptable as guidance perfor-
mance because a row width of wheat is 30 cm.
RTK-GPS antenna
GPS compass
PC and PLC
(Program logic
controller)
RTK-GPS receiver
FIGURE 2.16
Robot combine harvester.
