Description

TURTLE is an autonomous robotic deep sea lander, which has been developed by INESC TEC, the Autonomous Systems Laboratory (LSA) of the School of Engineering of the Polytechnic Institute of Porto (ISEP), the Portuguese Navy Research Centre (CINAV), and the companies ply and A. Silva Matos Metalomecânica (the latter was the leader of the consortium). It is operating since 2015.

TURTLE is a hybrid lander, being capable of staying at the bottom of the sea for long periods of time, but also of autonomously relocating itself and surfacing for maintenance operations. It is also able to dive and ascend with high-energy efficiency, and its autonomous capabilities allow for reduced operational costs and flexibility.

TURTLE is the first deep sea robotic system fully developed at Portugal.

Specifications

General

• Vehicle type: autonomous robotic deep sea lander
• Body materials: metal sandwich panels, syntatic foam, stainless steel
• Deployment: four hooks for craning, and capability to be towed
• Length: 1.9 m
• Width: 1.6 m
• Height: 2 m
• Weight in air: 1350 kg
• Power: rechargeable batteries (LiFePO4, 8 kWh, extensible)
• Battery charge time: 6 h
• Payload capacity: 200 kg
• Payload interfaces/ports: ethernet, serial RS232/485, with underwater connectors

Operation

• Maximum depth: 1000 m
• Autonomy: 1 month
• Relocation range: 500 m (without resurfacing)
• Propulsion: variable buoyancy system (VBS), four horizontal and four vertical thrusters (all independent)
• Degrees of freedom: 6DOF
• Communications: underwater acoustic communications; Wi-Fi/RF/GSM and satellite communications at the surface
• Navigation systems: DVL, IMU, USBL, mapping sonars, UW vision, GPS (pop-up and surface nav)
• Modes of operation: transportation to or from the ocean floor, multiple ascend/descend movements and seafloor re-positioning

Sensors

• USBL
• DVL
• INS/GPS
• Multibeam
• Pressure sensors
• Altimeter
• Video camera + lasers
• SLS system
• Seismometer
• Acoustic pinger
• Hydrophone to gather ocean sound data or launch alerts
• Additional payload capability