Launch and Recovery System

For Rolls-Royce Marine a simulator was developed replacing a full scale launch and recovery system. This is a system used on vessels during subsea operations for handling remotely operated vehicles from deck to working depth, mainly consisting of a hydraulic power unit, a winch and a handling unit; typically an A-frame.

LARS Rolls Royce


The original control system was running on a Siemens PLC. Direct access to the controller using a fieldbus was not possible. Therefore the HIL simulator had to be "hard wired" to the control system. To facilitate this a Bachmann M1 system was used to run the plant model as C-code.

Lars HIL Simulator

Plant Model

A numeric model was developed for the system including a hydraulic power unit, winch and A-frame. The numeric model comprised the hydraulic and mechanical dynamics of the system, and in addition an interface to the control system was implemented. For the mechanical domain, models representing a remotely operated vehicle and the umbilical connecting it to the winch were also created.


Several tests were performed to check if the developed solution was fit for purpose. The results from testing the simulator concept verified that it can be used for control system testing with respect to both hardware and software. Data logged during testing showed it can be also used for benchmarking as regards to system performance, as results from simulation corresponded well to previously measured performance of the real system in operation at sea. An example of data logged by the simulator during an active heave compensation performance test is shown in the figure below.

Lars Simulation