In the last post we had a look at co-simulation using MATLAB/Simulink with MotionSolve from Altair. With a co-simulation interface between the models, it is possible to take advantage of the strengths in each software, synchronizing the models and providing them with the means to communicate. However, at the conference in Sälen I gave a short presentation of a different approach – TCP/IP communication. This approach was investigated in a master thesis project carried out at the Combine office in Lund.
The process studied in the master thesis was a Gantry crane with the objective to pick up boxes and load them onto a truck. The Gantry crane model was created in IndustrialPhysics, a modelling software developed for HIL simulations. Some of the major IndustrialPhysics features are:
- Real time 3D simulations
- CAD model import
- Rigid body physics (enabling interaction between components for example)
- HIL solution
IndustrialPhysics has also been used in other projects carried out by Combine for customers within the industrial automation field, in which the models are executed on a real time target only (i.e. in a HIL setup). What makes the master thesis project interesting, is that it spanned the whole MBD process and included not only a HIL setup, but also the use of IndustrialPhysics and MATLAB/Simulink in a MIL setup.
In the MIL setup, a Simulink model is used to control the plant model running in IndustrialPhysics. The Simulink model contains control logic for the motion of the crane, with both a fully automatic mode and a manual mode, as well as a graphical interface (made to resemble actual control panel in rig) allowing the user to interact with the plant model when in manual mode. Interface blocks create a TCP/IP client object, allowing the Simulink model to read and write data to/from an IP address, and by defining an interface in the plant model for the same address the communication is established. The developer can now test and verify the controller before generating and deploying the code to the target hardware (in this case a PLC). By switching IP address in the plant model to that of the target, a HIL setup is achieved. This makes it possible to test the generated code when running on the hardware, using the same communication that may be used in the final product.
For more information, have a look at the master thesis report and let me know if you have any questions.