Robotic arm design Mike Paton Mechanical Engineer Mike

Robotic arm design Mike Paton Mechanical Engineer Mike Paton Engineering Design Ltd

Marine-i 142 Project • Objective. – Design a RDU robotic arm system and moving target system that can be used to demonstrate and develop the technology of stabilised payload movement between a vessel at sea and a moving target.

Marine-I 142 project • There are four main mechanical parts to the project. – ASSP RDU (Autonomous Synchronised Stabilised Platform Research Development Unit) – new design – MTTR (Moving Target Test Rig) – Modification to existing design. – 6 axis hydraulic motion system – Existing unit. – HPU (Hydraulic Power Unit) – 2 off existing units

HPU (Hydraulic Power Unit) • 2 off units which have a 63 amp input supply to a 30 KW motor with tandem variable displacement vane pumps. • At a pressure setting of 100 bar the flow rate will be about 160 LPM (litres per minute). • One HPU will be used to power the motion system. • Second HPU will power the RDU & MTTR.

Rotec HPU Unit

6 Axis Motion System

6 Axis Hydraulic Motion System • Motion system 6 axis movements and payload. – – – – Pitch = +/- 36 degrees Roll = +/- 33 degrees Yaw = +/- 45 degrees Heave = 960 mm Surge = 1000 mm Sway = 900 mm Payload capacity = 10 Tonnes

6 Axis Motion System Video

MTTR System

MTTR Movement Envelope • • Pitch = +/- 30 degrees Roll = +/- 30 degrees Yaw = +/- 10 degrees Elbow axis = 36 – 125 degrees (can be adjusted)

MTTR System Video

ASSP RDU System

ASSP RDU Movement Envelope • • Slew Axis = +/- 45 degrees Roll Axis = +/- 25 degrees Shoulder Axis = 60 degrees Elbow Axis = 140 degrees Wrist Axis = +/- 60 degrees Horizontal Reach = 4 m Vertical Reach = +4. 5 m -1 m Payload = 125 Kg

ASSP RDU System Video

ASSP RDU Design Objectives • Light weight and stiff arms with a design objective of 10 mm deflection at payload. • Greater than 1 Hz natural frequency. • Optimise hydraulic cylinder size to keep flow rates to a minimum. • Fast acting precision hydraulic system to enable good tracking of target.

RDU Deflections case 1

RDU Deflections case 2

RDU Deflection case 3

RDU Cylinder Loadings Case 1

RDU Cylinder Loadings Case 2

RDU Cylinder Loadings Case 3

RDU Stress Case 1

RDU Stress Case 2

RDU Stress Case 3

ASSP RDU L/H

ASSP RDU R/H

ASSP RDU L/H

RDU Slew Axis

Slew Axis Hose & Transducer

Arm Axis Bearing Design

Electrical Cabinet

Manifold Hydraulic Circuit

RDU Hydraulic Manifold Assembly

RDU Hydraulic Manifold Block

Factory Layout

2 D Interactive Sketch

Designing in a Virtual World • Use of Solid. Works 3 D modelling, FEA simulation and motion analysis. • Simulation of the hydraulic system using Mat. Lab Sim. Scape Fluids (Sim. Hydraulics) • Simulation of the control system using Mat. Lab

Conclusion • The Marine-I 142 project will enable us to test and develop motion compensation with a moving target within a factory environment. • We will be able to test and evolve the simulation models against actual test results. • With a growing confidence in our simulation models we will be able to up scale the design and reduce on very expensive real world testing on-board a vessel at sea.