A-LARS

Autonomous Launch and Recovery Systems

Launch and recovery is one of the highest risk operations undertaken in the application of towed or autonomous underwater vehicles. The primary function of an autonomous launch and recovery system is to enable an unmanned vehicle and its payloads to be brought aboard a host ship safely, efficiently and without damage.

 

Next-generation surface vessels will carry a variety of unmanned vehicles and modular mission packages that will require specialized launch and recovery equipment. With the establishment of Kraken’s Handling Systems Division (HSD) in Dartmouth, Nova Scotia, Kraken now has in-house capability to design and manufacture Autonomous Launch and Recovery Systems (A-LARS) for Unmanned Maritime Vehicles. Kraken’s team in Nova Scotia has  designed a LARS system for both the KATFISH as well as the THUNDERFISH products and also will do custom design work for third parties.

The HSD group is led by Bill Spencer who brings extensive experience in the aerospace and ocean engineering fields. Bill was recently the Engineering Manager at Rolls-Royce Naval Marine Canada and responsible for the development of advanced launch and recovery systems used by a wide variety of military, commercial and ocean science customers. The other members of the HSD are also ex-Rolls-Royce engineers and designers and have considerable expertise in ocean engineering.

The HSD group has designed the Kraken Tentacle Winch™ to tow the KATFISH™ (Kraken’s Active Towfish) and when coupled with our over boarding system it transforms into a complete, robust Autonomous Launch and Recovery System (A-LARS) making deployment and recovery of your assets as safe and easy as possible.

The Tentacle Winch is constructed of non-welded aluminum for high strength, low weight, and low magnetic signature. These properties are important for small host vehicles such as Unmanned Surface Vehicles (USVs) and mine counter measures (MCM) vessels.

The Tentacle Winch is a fully electric system which offers significant benefits compared to a hydraulic system in terms of system response and repeatability of winch motions, as well as environmental and efficiency benefits compared to similar hydraulic winches.

Advanced control features come standard on each winch and include:

  • Active Terrain Following (ATF) functionality that allows the Mission Control Computer to adjust cable scope to assist the KATFISH in active terrain following and obstacle avoidance.
  • Auto Tension (AT) keeps a constant specified tension on the tow cable allowing the Tentacle Winch to hold the KATFISH in the docking head during L&R phase without an additional capture mechanism.
  • Auto Render (AR) automatically pays out cable if the cable load exceeds a pre-set threshold.

When paired with the Tentacle Winch, Kraken’s A-LARS system turns your winch system into a launch and recovery system without the need for personnel on deck, keeping your crew safe.

The A-LARS has been designed and tested to recover the KATFISH in up to sea state 4 at a speed of 6 knots. This process can be conducted from the vessel locally or remotely via the remote link system.

The entire launch and recovery process of the vehicle is continuously monitored through sensors and video link. Video streaming of the docking head and winch are provided to ensure that all functions are operating within acceptable parameters. Furthermore, the A-LARS and Tentacle Winch leverages the dynamic motion compensation capability to provide smooth, safe, and robust launch and recovery for remote operations.

These video feeds work in parallel with the Tentacle Winch’s intelligent Active Motion Compensation system which compensates for the motion of the vessel and the A-frame during launch and recovery procedures.

This system mitigates risk and human error during high sea-states, wave action, and dynamic vessel movements by continuously monitoring vessel motion, using a predictive controller to vary tension on the tow cable ensuring safe and secure launch and recovery of the KATFISH.

The A-frame is driven with hydraulic cylinders powered by a dedicated marine hydraulic power unit. The cylinders are trunnion mounted to better withstand shock. The A-frame has three positions, stow, launch and recovery, and tow. The docking head is controlled in pitch by pantograph arms and controlled in roll by dampers