"Robot colleagues" are becoming increasingly common in CNC machining companies. However, in order to be able to perform material handling and other tasks, robots must be integrated into the workflow of machine tools.
Complete solution package
Depending on the application and task, a range of different requirements must be taken into consideration when connecting and integrating robots into machine tools. Perhaps the most common application is when existing machine tools are complemented with robots or existing robot cells are expanded using CNC machines.
The challenge lies in the fact that material-handling robots and machine tools are designed for separate applications by their manufacturers. If they are to work together, they must be connected in the field. It sounds easy, but the two control systems - CNC control and robot control systems - are already engineered, meaning that they speak their own language. As a result, communication between the control systems - and therefore synchronization of the two machines within the production process - must take place via interfaces. It is important that these interfaces be designed in such a way that even external systems integrators, such as machine distributors, can connect the handling robots and machine tools without affecting the applications of the machine tools and robots.
Connecting robots quickly and easily
With SINUMERIK CNC, these connections can be created using the pre-defined SINUMERIK Integrate Run MyRobot / EasyConnect project-planning interface. This interface can be flexibly adapted to meet the needs of the relevant automation solution. The concept is based on PLC handshake signals - a standard defined by the German Machine Tool Builders’ Association / German Engineering Federation for connecting robots or handling systems to machine tools. Working with a standard, as well as pre-defined NC/ PLC interfaces, alarms and diagnostics screens, and carefully documented example applications allows for quick and easy systems integration. Handling robots of different types and from different manufacturers can be quickly connected to machine tools using Run MyRobot / EasyConnect.
Controlling robots through CNC machines in everyday operations
Robots and machine tools are systems from different manufacturers with different architectures and operating philosophies. This poses particular challenges for the everyday operations of manufacturing companies because previously the set-up, programming and maintenance of a handling robot often required additional operating and maintenance personnel, or staff operating the machine tools had to be specially trained on the use of robot control systems. Both cost companies a great deal of time and money. Now, SINUMERIK Integrate Run MyRobot / Handling offers a more elegant solution. Here, the operation, programming and diagnostics of the handling robot are set out in the SINUMERIK operator interface in the machine tool. The great advantage of this is that the entire automation cell, that is, the machine tool and the handling robot, can be operated by machine tool operators without extensive training. Pick-and-place commands are exchanged between the CNC and robot control system through a special interface. The sequence program runs in an additional SINUMERIK machining channel. This means that the robot is programmed in the CNC.
Special Run MyRobot cycles expand the functionality of the CNC control system and mirror the command scope of the robot control system. The robot axes’ jog mode is also set out in the CNC system; that is, it is implemented through the machine control panel of the machine tool. In addition, error and operating messages from the robot are displayed on the CNC’s operator interface. The result: The operation, programming and maintenance of the handling robot become a fixed element of the CNC application, integration is greatly simplified, and the skills of the SINUMERIK operator are enhanced.
Run MyRobot / Handling is currently available for the mxAutomation interface of KUKA robots. Thanks to collaboration between Siemens and KUKA, a broad spectrum of automation solutions for machine tools and industrial robots is opening up with SINUMERIK.
Expanded applications and robots with CNC requirements
Alongside simple pick-and-place tasks, an increasing number of robot applications are requiring the fundamental properties of a CNC control system, such as constant speed, tool management or typical CNC programming. One example is path-controlled handling as a supplement within the machine tool, for instance, for gluing, deburring or polishing component contours. Another - even more sophisticated - example is machine tools with robot kinematics, for example, when milling molded parts made of soft or medium-strength materials.
SINUMERIK Integrate Run MyRobot / Machining meets the needs of these robots. In this case, the SINUMERIK CNC and the robot control system communicate through a realtime position interface. The kinematic transformation for the robot mechanics is computed in the CNC. This means that the entire available SINUMERIK CNC command set can be used to move the robot - from level selection (G17), to path commands (G0, G1, G2 …), to machining cycles. The sophisticated SINUMERIK control algorithms, such as dynamic startup, jerk control, look ahead and dynamic block compression, are also available for machining freeform surfaces. If needed, users can add to these options with another NX CAD/CAM process chain from Siemens PLM that is specialized in robot applications. The highlight here is the simulation of workflows based on real robot kinematics, and a postprocessor that is perfectly tailored to SINUMERIK. Run MyRobot / Machining can also be used in connection with KUKA industrial robots.