The system for remote monitoring and control of industrial robot motions based on the usage of Android device and Wi-Fi communication is developed at the Lola Institute。 Structure of the proposed system is shown in Fig。 1。

The system can operate in two working modes: the control working mode and the monitoring working mode。 In the control working mode the wireless control of industrial robot by using the graphical user interface of Android mobile device is provided。 The control can be performed by “speed dial” motion program selection, by standard motion programming or by manual mode control。 The “speed dial” motion program selection can be obtained within the Android application through the touch screen of the device。 The “speed dial” motion tasks can be define and redefined using desired set of robot motion instructions。 After selection of motion tasks, an execution file, in form of object code (run file), is sent to the real-time system。 The realtime system interprets instructions written in object code Wi-Fi communication and manages the robot motion based on the program content。 Android application contains run file database。 The run file is a motion program which contains parameters obtained by execution of algorithms for industrial robot path planning developed at the Lola Institute。 The run file is generated based on motion instructions that specify motion type, motion speed, motion acceleration and positions represented in internal coordinates, within the robot programming GUI for motion tasks programming and redefining on Android client。 Motion types are PTP – point to point, CIRCLE – circle movement, and LIN – linear movement。 PTP and LIN movement requires one position to be specified for motion execution and CIRCLE movement requires definition of one more auxiliary position。 After motions specification, the user generates an execution file, which can be assigned to the desired “speed dial” button。 The proposed implementation enables speed dialing of previously defined motion tasks on Android device。 The control can also be applied in manual mode, by adjustment of positions displacements of robot’s axes。 Displacements can be in positive and in negative direction。

Fig。 1。 Structure of developed system for remote monitoring and control of industrial robots based on Android device and

The monitoring working mode enables monitoring of robot’s work from the remote user’s location within the Android application。 It is provided through the 3D industrial robot movement or through the robot’s trajectory representation in a 3D coordinate system。 It can be applied in combination with the “speed dial” robot control, or manual robot control, but it can also be applied independently。

The Android mobile device and the real-time control system are connected into the network by using Wi-Fi 802。11 technology。 Communication is implemented using TCP/IPv4 protocol and Socket communication mechanism。 The real-time control system is connected to the robot using MOTENC board。 It performs sending of desired positions to the robot and reading achieved position of the robot from encoders。

3。2 Android Application Development

For the implementation of Android application Android/Java programming language is used。 Eclipse SDK [23] is used as a development environment。 The application is developed for 2。3。3 (API level 10) version of Android operating system。 For experimental testing the Android mobile phone HUAWEI G300 is used。

In the control working mode Android device represents a client。 The client is implemented by using Socket communication mechanism and Java programming language。 It represents the part of Android application。 The graphical user interface is implemented by using Java programming language and XML files。 Events that are generated by clicking on the appropriate button at the graphical user interface are connected to functions for sending commands and data to the server。 Message that can be sent to the server can be control message (defined in ControlActivity), and message for manual positioning of robot (defined in ManualMode Activity)。 Control messages are messages for starting or stopping robot’s work and messages for robot motion tasks execution (run files)。 There are several “speed dial” messages for robot motion tasks execution and each of them is connected to the corresponding run file from the run file database。 Run files contain parameters for the specific robot motion task execution and they are executed within the real-time system。 Parameters from run files are obtained based on algorithms for industrial robot motion (placed within the Interpolator component) which are developed at the Lola Institute。 A new run file with desired instructions, specified motion type, speed, acceleration and positions can be defined within the GUI of ProgramActivity。 The object code compiler translates specified motion parameters into the run file and places it into the run file database。 An appropriate speed dial control button within the ControlActivity GUI can be associated with generated run file。 This implementation enables quick and simple selection and execution of industrial robot motion tasks。 Manual positioning messages contain information about axis number and motion direction, and they are defined within the ManualModeActivity。 During the manual positioning of robot, the current robot positions are displayed within the ManualModeActivity GUI。