Research And Development Of Remote Four-axis Motion Control System Based On Android

In traditional industry, control system is mainly based on industrial PC with RS-485 or PCI bus as the communication method, which has shortcomings such as complex wiring, difficult maintenance, limited communication, non-mobile control and so on. With the rapid development of electronic technologies and equipments, intelligent mobile terminals and varieties of wireless communication technologies, the development of industrial automation and intelligence is promoted. Android has occupied the dominant position in intelligent operating system market due to its good user experience, varieties of control functions, superior performance and low cost since its first release in 2007.Accordingly, for multi-station workpiece automatic assembly system, related technologies of remote four-axis motion control system based on Android are analyzed and studied. And a remote prototype control system of four-axis motion platform is designed and implemented based on Android intelligent operating system. According to the overall structure and function of the system, the design and construction of the hardware and the development and implementation of software are accomplished.Based on the 3D modeling of the four-axis motion platform, the prototype is processed and built. Based on top-down design pattern, the hardware building of the control system is divided into three parts:Android intelligent control terminal, central controller and motor control module. The central controller consists of a microcontroller system and a UART-WIFI communication module, and the motor control module consists of a stepping motor, a stepping motor driver and a power module. The overall construction of hardware platform and design of circuit of the control system are accomplished through the design and selection of each functional modules, thus providing a solid guarantee for software implementation of the system.In the control system, the design and development of software system is the key part in the whole system. The design and development of software system are as follows:(1) The APP of Android smart phone is developed in Android Studio. Based on modular design pattern and using different layouts and components in Android system, the design and implementation of function and UI are accomplished in welcome interface, registering and login module, main interface, system configuration, system control module and other system information.(2) Allowing for the data processing and access in during system operation, the design and development of SQLite database of Android system is completed. Meanwhile, the communication mechanisms of Handler/Message and AsyncTask are adopted to realize the communication among local threads in Android APP.(3) The sophisticated C/S(Client/Server) architecture is used. Based on Socket communication mechanism of TCP/IP protocol, Android smart phone is used as the mobile client to communicate and interact with central controller as the server through remote connection via WIFI. And the detailed communication protocol is designed in the control system.(4) The main program of central controller implements the initialization and configuration of microcontroller, serial communication and motion control of stepping motors’ start/stop, acceleration/deceleration and reversing. Meanwhile, the "Base pulse control method" is proposed to control four stepping motors with one timer.Having accomplished the design and development of software and hardware, the APK package is installed in Android smart phone. The remote four-axis motion control system based on Android has friendly interfaces, flexible and stable operation.