Development of DGPS Guidance System for Agricultural Machinery

The purpose of this research was to develop a kind of light bar parallel guidance system based on DGPS for small agriculture machinery. This system consists of field computer, light bar and DGPS. The field computer is developed using PC/104 CPU module, running on which the embedded realtime operation system was customized by a special development tool. Single chip and CAN controller was selected for guidance light bar design, which use a row of indicator LEDs to guide drivers. Field computer and guidance light bar communicate with each other by using CAN bus. The guidance software running on the field computer was designed in object-oriented manner by integrating embedded GIS development kit. Field-testing and experiments have been done to evaluate the accuracy of the system with Trimble AgGPS 132 under different speeds, application width and light bar sensitivity, and the average of offline distance was 0.4517 meter. Results show this kind of guidance system is suitable for small-size machinery and can meet the need for parallel swath guidance for different kinds of field operation.