Abstract
This paper described a control system of mobile navigation robot for precision spraying in greenhouse environment,
which were composed of main control module, motor driving module, ultrasonic detecting module and wirless remote
control module. The hard circuits of control system were built. The main control module used ARM7TDMI-S-based
LPC2210 micro-processing controller. The motor driving module consisted of voltage amplifier circuit based
SN74LS245N and DM74LS244N chips, RC filter circuit, and HM-YZ-30 DC brush motor driver. The ultrasonic
detecting module consisted of four standard ultrasonic ranging modules which were arranged on the four sides around
the mobile navigation robot, and used GM8125 chip to expand serial communication interfaces. An obstacle-avoiding
strategy and its algorithm were proposed and the control programs of mobile navigation robot were programmed. The
mobile navigation robot for spraying can realize the actions such as starting and stopping, forward and backward moving,
accelerate and decelerate motion, and right and left turn. Finally, the functional experiments of the mobile navigation
robot were conducted in the laboratory environment. The results showed that the ultrasonic detecting distance of the
robot was 50.5mm-1832.0mm and detecting blind zone was less than 50mm, the ultrasonic detecting angle of individual
ultrasonic detecting module of robot was similar to U-shaped and its vaule was about 45.66°, and the moving path of
navigation robot was approximately linear.
