Simulator: AnyLogic is a general-purpose simulation environment for discrete, continuous and hybrid systems. It employs UML-RT structure diagrams for building hierarchical models in object-oriented way and hybrid statecharts for behaviour specification. The generated model is Java and can be extended with user’s Java code. The simulation engine handles discrete events and dynamically changing sets of algebraic-differential equations. It automatically detects “change” (or “state”) events. Debugging and visualization facilities are present.
Model: The model was intuitively decomposed into the following blocks: crane, control and sensors. The crane object consists of the crane- mechanics and the DC-motor. The mechanics of linear and nonlinear systems, as well as the DC-motor were implemented plainly using given equations. The control block generates voltage for the motor and switches on/off brakes, whereby discretisation is implemented by triggering the block with the sampling time. This object receives information about car status and car desired position. The sensors object implements checking and control of any emergency modes.