Research on Industrial Robot Monitoring Technology Based on PC SDK

— Around the ABB Industrial robot monitoring technology problem, study elaborated the composition and the application function of PC SDK development Interface Class Library based on Net platform, compared and analyzed the advantages and disadvantages of two development environment (virtual environment and real environment) of the robot Monitoring system under PC SDK. Besides, programmed a ABB robot local multi-machine monitoring system using C # language in the virtual development environment. Finally, connected the virtual controller, and verified the usability of the monitoring system. Some functions of the PC SDK were also realized.

Communication module installed. Regardless of the development method, the PC SDK version used in PC applications must be compatible with the Robotware version used by the controller. The two development environment configurations are shown in Figure 1:

B. PC SDK class library composition and implementation functions
The PC SDK class libraries are organized in the following domains: 1) Controllers The classes used to access robot controller functionality together make up the Controller API (CAPI).
2) ConfigurationDomain The Configuration domain namespace enables access to the configuration database of the controller. Using this domain you can read or write the value of a configuration parameter to the configuration database of the controller.
3) Discovery To create a connection to the controller from a PC SDK application it has to make use of the Netscan functionality of the Discovery namespace. A NetworkScanner object must be created and a scan call must be performed.

4) EventLogDomain
Event log messages may contain information about controller status, RAPID execution, the running processes of the controller, and so on.

5) FileSystemDomain
The File System Domain namespace enables to create, save, load, rename, and delete files in the controller file system. It is also possible to create and delete directories. 6) Hosting This is the main entrypoint for a host into the CAPI internal functions. It can be used to extend and alter the inner workings of the API. 7) IOSystemDomain IO System Domain is a robot system uses input and output signals to control processes. Signals can be of digital, analog, or group signal type. Such I/O signals are accessible using the SDK.

8) Messaging
The Messaging domain of the PC SDK can be used to send and receive data between a PC SDK application and a RAPID task.

9) MotionDomain
The MotionDomain namespace lets you access the mechanical units of the robot system.

10) RapidDomain
The Rapid Domain namespace enables access to RAPID data in the robot system. There are numerous PC SDK classes representing the different RAPID data types. There is also a UserDefined class used for referring to the RECORD structures in RAPID.

11) UserAuthorizationManagement
In the robot controller there is a system controlling user access: the User Authorization System(UAS). If this feature is used each user needs a user name and a password to log on to a robot controller via RobotStudio. If the controller connection for any reason is lost, you need to log on again.

III. ESTABLISH COMMUNICATION
Using the development mode of the virtual environment to develop the monitoring application, the virtual workstation of IRB120 robot is built by using Robotstudio 5.15 simulation software to simulate the real robot working scene, and the virtual controller and PC communication can be realized. The IRB120 robot virtual workstation is shown in Figure 2: The workstation is able to control the robot with the I/O signal to carry out the conveyor.

IV. MULTI-ROBOT MONITORING SYSTEM
Based on the PC SDK in the virtual development environment, this paper develops a local multi-machine monitoring system for ABB IRB120 models, and the initial interface of the system is shown in Figure 5: The multi-machine monitoring system includes the following functions: 1) Scan all robot controller information on the same network. As shown in Figure 6: 2) Select the robot to be monitored according to the controller information in the scan result and create a monitoring window. The function in Figure 9 is described as: 1: Switching between the world coordinate system, the base calibration system, the workpiece coordinate system, the tool coordinate system, and the custom coordinate system.

2:
The running speed ratio of the robot.
3: Input signal status value of the robot workstation.
4: Connection status of the robot controller.

5:
The operating mode of the robot. 6: Robot system time. 7: X, Y, Z are the coordinate values of TCP in different coordinate systems, Q1, Q2, Q3, Q4 are the direction quantities of the robot in different coordinate systems, and Rax_1, Rax_2, Rax_3, Rax_4, Rax_5, Rax_6 are robots 1 to 6-axis joint rotation angle value. 5) always acquire the mechanical unit, work task and routine of the current operating system of the robot, and view the text content of the routine program in the form of text, and can control the start and stop of the routine program. As shown in Figure 10: The features in Figure  3: Some operations on the routine. among them: :Update the information in 1.
:View routine text content.
:Save the module file from the controller to the local computer.
:In automatic mode, start the routine program that is selected in 1.
:Stop the 1 current routine program in automatic mode.
V. MONITORING SYSTEM VERIFICATION The experimental verification of the multi-machine monitoring system was carried out using the established IRB120 robot virtual workstation (shown in Figure 5) in Section 3. The current pose of the robot in the virtual workstation is shown in Figure 11: Query the current I/O system input signal value of the robot in the RoubotStudio simulation I/O module, as shown in Figure 15: The multi-machine monitoring system monitors the current I/O input signal in the robot status information as shown in Figure 16:

VI. CONCLUSIONS
The practicability of the PC SDK secondary development interface reserved by control system of ABB IRB120 robot based on the .Net platform was confirmed in this study. And a set of local multi-machine monitoring system for IRB120 industrial robot is designed.This system realized the local monitoring of IRB120 robot, and lays a practical foundation for the development of ABB Industrial robot remote Monitoring system in the future.