Development of controller for digital position sensor and its software

Abstract

For the operation of electric drives control systems, closed on the target coordinate of control – speed or position of actuator, an informational and measuring subsystem, formed by hardware and software to detect, capture and process signals from sensors, is required. The functionally completed and independent elements of such a subsystem are the controllers of each of the sensors, including digital position sensors, also used to measure the speed of motion. When developing such a controller, it is necessary to take into account the requirements for control system, performances of sensors and their signals, the form of position measurement result, the technique of the sensor interfacing with the control system, the features of hardware and software computing resources, including execution time. Thus, the development of a digital position sensor controller and its software is an actual problem. When developing the controller, methods of computational mathematics and system analysis, methods of model-based programming, methods of software developing and debugging, as well as methods of experimental research were applied. An algorithmic description of the digital position sensor controller is proposed for converting the angular position of the electric drive shaft, which changes cyclically within one revolution during rotation, into its rotation angle, which has wide limits of change. Also, the measuring of rotation speed of the electric drive shaft is algorithmically described by calculating the increment of its angular position during the observation interval. The software for this controller has been developed, which can serve as a typical element for microprocessor control systems for electric drives. When developing a controller for a digital position sensor, as well as other elements of the informational and measuring subsystem of closed-loop electric drives, it is necessary to take into account the performances of various technical means and requirements for the control system. Successful development is contributed by the use of modern microcontrollers with built-in specialized modules for detecting, capturing and processing signals, as well as the use of detailed computational algorithms and mathematical methods that are the least expensive in terms of execution time.