Spherical coordinates control system for accurate orientation of directional antennas

In this paper is presented a novel implementation of a spherical coordinates control system intended to be used for dynamic orientation of communication antennas. The proposed control system is composed by three electronic modules: the interface with the computer, the motor drivers and the stepper motors with mechanical elements for antenna orientation. The control algorithm is implemented as a LabVIEW software application that runs on the computer and sends periodic commands to the external modules. The connection between the external modules and the computer is realized through the parallel port. Also, the interface of the external modules ensures galvanic insulation for proper protection of the computer. In the presented implementation an angular resolution of 3,25 degrees was obtained using half-step command of motors but the accuracy can be easy improved with minor changes in hardware and software structure of the system. By programming the control application using LabVIEW environment are obtained important advantages as: intuitive interface for the user, modularity of the program, simple implementation, and flexibility in developing new features for the proposed system.