Attachment_2_to_W912BU-19-B-0012_Reference_Drawings_2.pdf

GENERAL NOTES:

1. CABLE TYPES SHALL BE TNIA ARMORED TYPE MARINE CABLE AND IN ACCORDANCE WITH ABS, USCG, IEEE-45 FOR SHIPBUILDING, AND SECTION C725 c. OF THE SHIPS SPECIFICATION.

2. CABLE IDENTIFICATION MARKINGS SHALL BE IN ACCORDANCE WITH SECTION C702 c. OF THE SHIPS

SPECIFICATION

3. MAXIMUM VOLTAGE DROP FROM THE MAIN SWITCHBOARD TO THE END COMPONENT SHALL BE LESS

THAN 5%.

GENERAL NOTES:

1. CABLE TYPES SHALL BE TNIA ARMORED TYPE MARINE CABLE AND IN ACCORDANCE WITH ABS, USCG, IEEE-45 FOR SHIPBUILDING, AND SECTION C725 c. OF THE SHIPS SPECIFICATION.

2. CABLE IDENTIFICATION MARKINGS SHALL BE IN ACCORDANCE WITH SECTION C702 c. OF THE SHIPS

SPECIFICATION

3. MAXIMUM VOLTAGE DROP FROM THE DC POWER SOURCE TO THE END COMPONENT SHALL BE LESS THAN 5%.

Final Phase 3 Report

Mat Sinking Automation Design

Other Transaction Agreement (OTA) W15QKN-13-09-0001 Prototype Project Agreement (PPA) No. SINIT-16-0010

Prepared for:

United States Army Corps of Engineers Marine Design Center

Philadelphia, PA

Distribution D: Distribution Limited to Department of Defense and U.S. DoD Contractors Only (Critical Technology)

Prepared by:

300 East Lombard Street, Suite 1430 Baltimore, MD 21202 and

Ten 40th Street Pittsburgh, PA 15201

March 1, 2019

Phase 3 Final Report

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TABLE OF CONTENTS Page

1.0 INTRODUCTION

1.1 Objectives

1.2 Brief System Overview

2.0 PLACEMENT ARM PROTOTYPE

2.1 Gantry

2.2 Base Frame

2.3 Arm Beam

2.4 Carriage

2.5 Lifting Frame

2.6 Deck Conveyance

3.0 AUTOMATED TYING PROTOTYPE

3.1 Overview

3.2 Tie Module Operation

3.3 Scarf Box Sensing

3.4 Hopper

3.5 Chute

3.6 Feeder

3.7 Z-Stage

3.8 Tie Head

3.9 Cable Gatherer

4.0 MANUAL TIE GUN

5.0 WINCH CONTROL PROTOTYPE

5.1 Tension Equalization test setup

5.2 Mooring Position test setup

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6.0 CONCLUSION

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1.0 INTRODUCTION

To aid the Department of Defense (DoD), the United States Army Corps of Engineers (USACE) has the mission to support critical activities through the development of innovative strategies and technologies for naval architecture, marine engineering, and navigation. In support of this mission, USACE is seeking technology development to achieve cost reduction and improve schedule and efficiency for navigational waterway maintenance that may be applicable to both US and overseas defense areas.

One operation that the USACE is looking to improve, Mat Sinking, is an antiquated technique used to install concrete mats on the banks of waterways to stabilize the channel. The USACE sought solutions in the form of design, development, and testing of an innovative solution to upgrade this antiquated process. The goal is to identify a new mat sinking technique that utilizes automated technology for greater process efficiency, improved safety, and reduced environmental impacts. The technology solution must be inclusive of the mat laying mechanical, sensing, and control systems, as well as process controls. The USACE has specified that the new techniques must be accomplished in a manner that minimizes impact to the waterway and all associated ecosystems reducing the environmental impact.

This project is being completed in phases, with information from each phase aiding the further system development in subsequent steps. Phases 1 and 2 have previously been completed. Phase 1 included technical evaluation and assessment of viable automated systems for the mat sinking operations. Phase 2 was focused on the design of the automated system(s) selected.

This Final Phase 3 Report presents an overview summary of the prototyping work that was completed during this Phase of the project. Specific test results from the prototype testing will be presented in a separate Phase 3 Functional and Safety Test Report. This document was prepared by the SIA Team, including the Carnegie Mellon University (CMU) National Robotics Engineering Center (NREC), in partial fulfillment of the requirements of Other Transaction Agreement (OTA) W15QKN-13-09-0001, Prototype Project Agreement (PPA) No. SINIT-16-0010 as administered by the Consortium for Energy, Environment, and Demilitarization (CEED). Contracting Officer’s Representative and technical oversight responsibilities for the project were provided by the USACE, Marine Design Center, Philadelphia, Pennsylvania.

1.1 OBJECTIVES

The basic objectives of this initiative are:

Design, fabricate, and test automated mat laying technology including mechanical, sensing, and control systems for application on a barge vessel platform.

The design shall include process systems to enable control of functional components for placing mat squares onto the assembly barge; successfully connecting the squares; and ultimately placing the mats on the waterway bottom.

The prototype shall be a full-scale, functioning system to demonstrate the form, fit, and function of the technology.

The automated system shall utilize software, computer code, and intellectual property that can be obtained commercially or provided to a contractor for full production.

The final system will stabilize critical navigation waterways and ensure that they are available to complete the DoD’s mission.

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1.2 BRIEF SYSTEM OVERVIEW

The Phase 3 development and testing effort is divided into five distinct systems that were tested and verified independently to be later combined in future phases. These test set-ups are divided into:

Square Placement and Conveyance Automated Tying Traction Winch Tension Equalization Mooring Winch Position Control Manual Tie Gun

The square placement and conveyance test set-up is comprised of all the components needed to locate, lift, place, and convey the squares from their pick-up location onto the deck and then lower past the placement area.

The automated tying test set-up demonstrates the ability for the system to autonomously locate scarf boxes and tie fabric wires along the length of squares for both the side and end locations.

The tension equalization test set-up mimics the use of the traction winches on the mat boat. This test set-up senses an uneven load between a small set of winches and demonstrates the ability for the load to be normalized between them.

The winch positioning test set-up mimics the movement of the overall barge system. For this test, multiple winches are used to demonstrate how motion control can be achieved when there is an outside disturbance load added to the system.

Finally, the manual tie gun demonstrates the usefulness and application of a portable electric version of the pneumatic powered tie guns currently used in the matsinking operation.

2.0 PLACEMENT ARM PROTOTYPE

The design and implementation of the placement arm was focused on lifting and delivering squares onto the mat deck and subsequently proving the conveyance for the squares between the placement and tying zones. The test setup contains the following components:

Test Stand/Gantry Placement Arm Carriage Lifting Frame Mat Deck (representation) Passive Alignment Deck Conveyance Scarf Box Sensing (for conveyance)

The Phase 3 placement arm test setup can be seen in Figure 1. This test setup was erected and implemented on site at the National Robotics Engineering Center facility in Pittsburgh, PA, as seen in Figure 2.

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Figure 1: Overview of placement arm test setup for Phase 3 of the Matsinking program

Figure 2: Site plan of placement arm test setup at NREC facility in Pittsburgh, PA.

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The test gantry and placement arm system were developed with a sub-contractor (TC-American) under the direction of the NREC engineering team. At the end of Phase 2, the contractor provided NREC with a preliminary design for the placement arm that captured its overall design strategy, performance, and sizing. The design at the end of Phase 2, as shown in Figure 3, was continued in Phase 3 to completion and implementation.

Figure 3: Design of placement arm at end of Phase 2.

2.1 GANTRY

The gantry structure provides the linear rail and power distribution lines to allow for y-motion of the placement arm. The contractor, TC American, integrated their proprietary rail system that could hold the desired operational loads of the placement arm. Along the outside of the shore side of the gantry is a set of festoon cables that supply power to the arm (that connects at the base frame). This festoon is a critical component that will constrain cables during the Y-motion. In future phases, multiple sets of festoons will be integrated to supply power to multiple placement arms. Additionally, the gantry features a set of hard stops and limit switch targets that will prevent the placement arm from moving beyond its desired range of motion during testing. The gantry structure was built and installed for preliminary testing at the supplier’s (TC American) production facility and then transported and installed on-site at

NREC.

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Figure 4: Detail of gantry systems developed in Phase 3.

Figure 5: Gantry installed at NREC facility in Pittsburgh, Pa.

2.2 BASE FRAME

At the end of Phase 2, the base frame assembly was designed to a point of mechanical integration. The trolleys, rails, and structure were designed and selected, but much of the supporting equipment was not yet integrated, as shown in Figure 6. During Phase 3, several of the systems required for implementation were added to the base frame assembly.

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Figure 6: Base frame design at the end of Phase 2

Figure 7: Base frame integration for Phase 3

The base frame` structure and trolleys were both carried over and unchanged between Phase 2 and Phase 3. Three electrical cabinets were also added to the assembly: the power box, filter box, and control box as shown in Figure 8.

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Figure 8: Layout of electrical boxes integrated into base frame assembly and internal layout of each box

Two drive assemblies provide the Y-axis motion of the base frame along the gantry length. Both assemblies feature a pivoting motor mount, motor, drive pinion, encoder pinion, and lubrication pinion, as shown in Figure 9. Each Y-axis drive assembly features a vertical adjustment pin that ensures proper engagement between the drive pinion and rack. Additionally, the assemblies were designed to allow for the weight and center of gravity of the assembly to pivot the drive gears into the rack, maintaining engagement.

Figure 9: Y-Drive motor module detail

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The motor that actuates the stowing motion for the arm beam is also installed on the underside of the base frame. This motor is offset to one side of the base frame and, unlike the y-drive motor frames, does not have a pivoting engagement and is mounted in a fixed manner instead.

A set of four custom designed trolleys are installed on the bottom of the base frame that hold the load of the arm beam, carriage, lifting frame, and live load. These trolleys have been designed in a manner to incorporate an engineered roller and guide rail system from Winkle Engineering. These components were selected for their high load capacity and consistent level of tolerance and engagement. The trolleys feature two degrees of freedom to ensure that when they are all engaged on the rail system there is limited binding. The trolleys connecting to the top of the arm beam have a unique feature that clamp onto the winkle rails. This clamping feature has two main functions. First, the clamps are used to transfer the load from the arm beam and attached components from the support wheels more directly onto the support structure. This assists in unloading the support wheels and prevents the point contact of the wheels from permanently wearing into the rail over time. Secondly, the clamps help to maintain the linear position of the rail along with the rack, pinion, and stow motor brake. The clamps are manually engaged onto the rail using a standard socket attachment. A secondary plate is installed on the support structure that maintains the rotation of the clamp screw during operation.

Figure 10: Base frame trolleys that connect to the arm beam rails

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Figure 11: Detail of the rail clamps on the base frame to arm beam trollies.

The construction of the base frame was completed at the TC American facility. Once the base structure was fabricated, NREC worked at their facility to install the electrical and drive components. The assembly can be seen in Figure 12 below.

Figure 12: Base frame undergoing final wiring and assembly at TC American facility.

2.3 ARM BEAM

The arm beam is the main structural component that supports the carriage, lifting frame, and square load for placement operation. Its design allows for the load to move linearly along the length of the arm beam. The arm beam has the primary beam structure, two sets of rails (upper set to connect to the base frame trolleys and a lower set that connect to the carriage trolleys), cable management from the base frame, a festoon support that supports cables to the carriage, and drive racks for both the stow motion and the carriage motion as shown in Figure 13.

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The cable management system used between the base frame and the arm beam is an IGUS brand electrical chain. This system features several connected pivoting links with specified internal shelves and dividers that maintain minimum bend radius requirements for all cables as well as allowing for smooth motion of the cables during the stowing operation.

Figure 13: Arm beam components

The arm beam structure’s design was set at the end of Phase 2 featuring a series of internal diaphragm plates that distribute load while minimizing weight as shown in Figure 14. During Phase 3, the supporting components for the drive system and cable management were added before the arm beam went into fabrication.

Figure 14: Detail of arm beam internal design at culmination of Phase 2

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The design of the arm beam was completed from the Phase 2 preliminary design by NREC along with input from TC American, as shown in Figure 15 below.

Figure 15: Phase 3 design of arm beam along with integration details with carriage and festoon

Figure 16: Arm Beam being welded at TC American facility. Diaphragms can be seen within the arm beam structure.

The arm beam features a lower set of winkle rails that are used to support the load of the carriage, lifting frame, and live load. These rails, which are slightly smaller than the top set of rails that connect to the arm beam components, have their own set of trolleys that ride within the rails that are connected to the carriage. These trolleys are similar to the upper trolleys in operation in that they both have two degrees of freedom in alignment, but do not feature a rail clamping mechanism.

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Figure 17: Trolley for the lower rails connecting the arm beam to the carriage

2.4 CARRIAGE

The carriage contains all the motors and equipment that lift and lower the lifting frame for placement operations as well as the motors that move it linearly along the placement arm beam. The carriage is split into two main structures. The upper carriage contains the attachment point for the trolleys that ride along the arm beam rails, the motor used for linear motion along the arm beam, and the turntable base for the yaw axis of motion (which allows the carriage to be rotated along the vertical axis).

Figure 18: Carriage Overview

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The yaw axis turntable was designed to allow the lower carriage to rotate while holding a maximum two square load. Even though the turntable can rotate over a full 180 degrees in either direction with its turntable bearing, its motion will be limited using hard stops and limit switch sensors. This is to prevent wiring and cables from twisting through multiple rotations. The drive for the yaw axis is mounted onto the lower carriage and interacts through a pinion gear on the outside of a large geared slewing bearing.

Figure 19: Yaw Axis Detail

The lower carriage contains the structural support and drives for the hoists that lift and lower the lifting frame. Two identical hoist assemblies, the yaw drive assembly, cable reeving assemblies, two electrical boxes that contain power distribution and control equipment, and hoist drums are all part of the lower carriage assembly.

Figure 20: Lower Carriage Assembly

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The hoist drive assembly contains the drive motor, safety brake, gearbox, and two connected grooved drums. Each drum has an encoder measuring its output rotation. The hoist drive assembly and drums were designed and sized to allow for the lifting frame to be raised at full operational speeds (as determined in Phase 2), with full loading, using only a single wrap of cable around the drum (along with safety wraps on the drum). The whole hoist drive assembly itself is a modular component that could be removed and replaced as needed for maintenance.

The frame alignment rollers interact with features on the lifting frame that constrain the motion of the lifting frame when fully retracted. These help to keep the lifting frame and carriage together when it is fully retracted and reduce the overall sway of the lifting frame when at fully retracted height.

The reeving assembly provides a proper path for the cable to exit the drum and loop around the lifting frame connection pulley. One of the key interaction points for the reeving assembly is to ensure that proper fleet angle is maintained between the cable exiting the drum and where it enters the first eight-inch pulley for the reeving assembly. The design maintains the proper reeving angle for this application no matter where the cable is being paid out from the hoist drum. The reeving assembly also features a tension arm that takes up any slack in the cable during operation. At the end of the reeving assembly, the lifting cable is attached to a heavy spring assembly (that takes up any shock loading during pick-up) and a load cell that monitors the engagement and lifting load on the cable.

Figure 21: Reeving Assembly

2.5 LIFTING FRAME

The lifting frame sub-system contains all the mechanisms required to align to and lift squares. The major components are the lifting frame structure, square grabbers, side active alignment, end active alignment, passive retraction, and carriage alignment systems. There were substantial updates to the design of the lifting frame and included systems between Phase 2 and Phase 3 as can be seen in the images below.

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Figure 22: Design of lifting frame at the end of Phase 2

Figure 23: Design of lifting frame for Phase 3

At the beginning of Phase 3, four square grabbers were combined onto a surrogate assembly to confirm their operation. This assembly was used to test the control and load capability of the square grabbers as well as verify preliminary operation of the height sensors. This system proved the capability of the square grabber mechanism, but the design still needed to be updated to integrate with the overall lifting frame assembly.

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Figure 24: Four Square Grabber Assembly and Testing

The design of the overall lifting frame was intentionally modular to allow for replacement and maintenance of components. The square grabber casing that holds the linear rails and chain was designed to maintain modularity while still having a high level of strength. The Phase 3 square grabber assembly also features components added for debris protection and maintainability. A debris cover was added to protect the chain assembly as well as keep it safe around any operators during maintenance.

Also, wipers were added to the linear rails to ensure dust and debris is kept clear of the moving components.

Figure 25: Phase 3 square grabber assembly installed on the lifting frame

The active alignment system underwent significant design updates between the end of Phase 2 and Phase 3. In Phase 2 the active alignment system used linear actuation for both the side and end locations. During Phase 3 the active alignment system was revised to feature 4-bar actuation mechanisms to reduce the overall complexity and number of moving parts. These actuation arms are

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able to accommodate +/- six inches of misalignment to allow for a maximum 10” clearance to adjacent stacks on pickup.

Figure 26: Active alignment system at end of Phase 2 featuring linear actuation

Figure 27: Preliminary build of side (left) and end (right) active alignment arms for the lifting frame

The actuator that was designed and used in Phase 2 for the active alignment was retained and revised for use on the Phase 3 components. Its stroke was reduced to decrease actuation time as well as having its bore increased to provide more actuation force. When in use, the actuator can provide 585 pounds of holding force (at maximum arm extension) for the side assemblies and 260 pounds of holding force on the end assemblies.

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Figure 28: Active alignment actuator assembly

The lifting frame also features a set of passive alignment structures that interface with the deck to ensure squares are placed on the deck in a controlled fashion with proper clearance. Since these structures protrude out under the lowest point of the lifting frame structure, it is possible that they could interfere with the supply barge when picking up the last few squares of the stack. Because of this, they are required to retract out of the way to ensure clear operation. The retraction mechanism used features an over-center locking linkage. This ensures that when the passive alignment structure is in its deployed position, it is locked in place and can withstand any side loading that can be present during operation.

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Figure 29: Detail of passive alignment assembly installed on end of lifting frame structure

Figure 30: Passive alignment assembly shown in both deployed and retracted states of operation

In addition to the active components, the assembly has a single electrical control box that distributes power and control to all the actuators and sensors on the lifting frame, a pneumatic system that has several high- and low-pressure reservoirs and an on-board compressor, and passive alignment structures that align with the carriage pockets as noted in previous sections. The completed lifting frame assembly can be seen in Figure 31.

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Figure 31: Lifting frame full assembly with wiring and pneumatic system installed lifting two squares

2.6 DECK CONVEYANCE

The conveyance system underwent significant design updates between Phase 2 and the implementation in Phase 3. The main improvement to the conveyance system was updating the drive system used to move the squares. The preliminary design in Phase 2 featured a conveyor system that would move the squares between placement and tying zones. Based on a matsinking unit site visit, it was determined that several design factors needed to be considered for the implementation. First, the overall weight of the conveyance system needed to be reduced. Since there are 35 of these assemblies on the final implementation, a reduction in weight on the drive assembly would greatly benefit the overall weight of the vessel. Next, the overall mechanical complexity of the deck conveyance assembly needed to be reduced to allow for more reasonable maintenance. Finally, the decision to move away from the conveyor to the driven wheel system was to allow for better debris handling with the conveyance mechanism. The design update resulted in a 31% reduction in part count and a 68% reduction in weight.

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Figure 32: Multiple design approaches for deck conveyance- Conveyors and Driven Wheels

Figure 33: Conveyance drive module for Phase 3 implementation

The square conveyance system is divided into two primary zones: placement and tying. In the placement zone, each row of active drives is independently actuated, allowing for neighboring squares to be moved without affecting one another. To assist with the alignment of the lifting frame and squares in the placement area, passive alignment pockets (similar to those featured on the carriage) are installed at a set distance apart. Each row has seven pairs of drive wheels all driven off a common motor connected by chain. On the outside of the drive wheels are sets of passive roller wheels where the majority of square load is maintained.

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Figure 34: Conveyance Zones

The tying zone features the same mechanisms as the placement zone conveyance system but does not have alignment pockets. For Phase 3, each row of the conveyance equipment is driven off its own motor, but in use all rows for the trying zone conveyance will be actuated in unison to simulate operation on the final system where there will be linked motion between all rows in the tying zone.

The drive rollers were custom designed to ensure proper engagement and friction with the squares.

The wheels have a passively compliant structure to allow for deformation along the square to ensure contact pressure at all times. The drive system was tested using a sub-set of drive rollers and square blocks.

Figure 35: Active conveyance drive rollers interacting with the square bottom surface

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Figure 36: Test set-up for single drive roller conveying four square blocks at deck angle

For the Phase 3 placement test setup a deck structure was designed to support the deck conveyance equipment and provide a structure for square placement. This structure’s size was modeled after the placement deck that will be implemented on the final system. This structure was welded off-site at a contractor’s facility and shipped in a single piece to the NREC test site.

Figure 37: Placement deck arriving on a flatbed trailer on-site at NREC

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Figure 38: Deck installed on footers at the NREC test site

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Figure 39: Conveyance system installed onto the deck structure

3.0 AUTOMATED TYING PROTOTYPE

3.1 OVERVIEW

The automated tying system prototype verifies the automated motion of the tie gantry and tie modules as well as verifying the automated automation of the side and end time modules. Each of the side and end tie module has the capability to singulate, feed, and tie the fabric wire of the squares as well as gather the fabric wire to assist with the tying process. For this prototype there is no method of square placement or alignment. Instead, squares were placed as needed using auxiliary support equipment.

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Figure 40: Rendering of automated tying test set up

3.2 TIE MODULE OPERATION

The tie module is composed of a series of custom designed automated components as shown in Figure 42. The redundant motion frame serves as a base structure for all the components for the automated tying process. The rods are loaded into the hopper before operation. The hopper is then used to singulate the rods one by one. The rods are then fed through a chute which orients them to the entry of the feeder mechanism. Once the feeder advances the rod to the tip of the tie head the system plunges the tie head and gatherer fingers into the scarf box. During the plunge motion the cable gatherer moves the fabric wires inward towards the tie head. Once it is fully plunged within the scarf box, the feeder then advances the remainder of the tie rod to ensure a proper tie. Finally, the tie head is then actuated to complete the tie and the tie head is retracted. The tie module then moves to the next scarf box and this process is repeated.

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Figure 41: Image of the full automated tie module system

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Figure 42: Automated tie module and components

3.3 SCARF BOX SENSING

A set of cameras is integrated onto the tie module to sense the location of the scarf box and determine if it is clear for the tying operation. The visual data from the scarf box sensors is used to classify the components within the scarf box into square edges, launch wire, fabric wire, and tie (if it has already been completed). The algorithm is then used to determine if a tie is likely to succeed in that scarf box.

After the tie is completed with the automated tie system, the algorithm is then used to determine the quality of the tie.

Figure 43: “Quadcam” stereo vision sensor installed on the tie module

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Figure 44: Scarf box sensing output showing classification of components

The scarf box sensors are also used in other processes for mat tying. When a square is being conveyed between the placement and tying zone, the scarf box sensors can be used to ensure proper alignment of the squares. In Figure 45, the process for scarf box detection for alignment is highlighted. First, the system reads the left and right images files as well as the left and right side calibration information. Next, the system computes a disparity image. After extracting the top plane of the disparity image, the scarf boxes are located used template matching. This allows the system to compare scarf box locations and then servo the deck conveyance as needed.

Figure 45: Image processing for scarf box sensors to detect proper square alignment

3.4 HOPPER

The hopper mechanism underwent significant updates from the end of Phase 2. The mechanism in Phase 2 used a rotating drum to singulate rods from the hopper. For Phase 3, the design was updated to increase reliability. The updated design used a single linear actuator to move a set of steps. As the steps are moved upward it moves a single rod up onto an intermediate ledge. When the step retracts, the rod gets seated into place on the ledge. On the next actuation of the step, the rod which is in the first ledge gets moved up further until it is pushed over the ledge out of the mechanism towards the chute. The hopper singulation system relies on the geometry of the steps and the rods to ensure only a

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single rod is ever fed into the chute. A series of sensors are also integrated into the hopper to notify the automation system of a few conditions. First, there is a sensor that detects the level of rods in the hopper. This sensor can be used in future implementations to notify the system operator to refill the hopper.

Figure 46: Example operation of the hopper singulation system

Figure 47: CAD model (left) and physical build (right) of hopper and singulation system

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3.5 CHUTE

Once the rod is singulated from the hopper it is transferred into the chute. The main purpose of the chute is to reorient the singular rod from a horizontal position to a near vertical position. The chute does this passively by having the rods follow a curved surface. As the rod interacts with the curved surface it rotates and becomes aligned with the exit of the chute. A sensor at the entry to the chute lets the automation system know when a rod has been singulated so that the singulation system waits until it is fed through the tie head before feeding the next rod.

There are also features included on the chute that assist with the case where a rod does get stuck into the chute. A simple pin is removed which allows for the chute spacer to be rotated out. This allows an operator to clear out any jam and quickly reset the mechanism for continued use.

Figure 48: Motion of the rod within the chute

3.6 FEEDER

The automated feeding assembly captures and moves a singulated rod into the tie head assembly. The feeding assembly has a motor that actuates a grooved drive wheel that acts against the tie rods to move it linearly into the tie head. A sensor is integrated into the assembly that detects when a rod is fed into the system. Additionally, an encoder is incorporated into the assembly to measure the rotation of the feeder wheels. This is critical to ensure the rod is fed to the proper depth into the tie head.

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Figure 49: Feeder mechanism CAD model (left) and physical build (right)

The feeder mechanism, like many of the other assemblies in the tie system, is completely modular and can be replaced on its own for maintenance needs.

3.7 Z-STAGE

The z-stage assembly moves all of the components that are required for the tying operation into the scarf box. These components include the feeder, the tie head, and the cable gatherer. Two pneumatic actuators are used to move the assembly vertically towards and away from the scarf box. The z-stage also has a set of compliant springs that allow for the tie module to self-adjust and align into the scarf box during the plunge motion. When fully retracted, the z-stage is constrained against the rest of the redundant stage structure to ensure it is captured during non-plunging motions.

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Figure 50: 3D model of the z-stage assembly (with cover and cable gatherer removed)

3.8 TIE HEAD

The tie head for the automated tie system is based on technology that has been used on the matsinking barge in its current operation. Several modifications have been completed though, to assist with the automated operation and to make fabrication of the mechanism more efficient. Firstly, a critical sensing component was added to the assembly to allow for the counter-rotating tie gears to be properly homed in between ties. A hall effect sensor and magnet were integrated into the tie head assembly to measure the rotation of the tie gears and indicate when the gears are aligned.

An additional feature added to the tie head is an ejection system that allows for the side shrouds and tie gears to be released in the case when the tie head is jammed on the fabric wire during automatic operation. Even though this is expected be needed rarely, it is a critical feature that lets the tie module release from the jammed components so that the other tie modules on the gantry can continue their operation. The release mechanism for the side shields (which in turn hold the tying gears) is contained within the z-stage assembly. The actuation solenoid actuates linkages that release a pin from the side shields. There are sensors on the tie head assembly that monitor the pin that retains the side shields and confirm that it is locked in place for regular operation.

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Figure 51: CAD model of tie head showing internal mechanisms

3.9 CABLE GATHERER

The cable gatherer mechanism is used to ensure that the fabric wires are within range of the tie head to have successful ties. The mechanism is attached to the front of the z-stage assembly. It features two degrees of freedom of motion – a pinching motion that moves fabric wires towards the center between the two squares and a lifting motion that moves the fabric up towards the tie head gear center. The pinching motion in the preliminary Phase 2 design as well as the lifting motion were both initially actuated passively when the z-stage was pushed onto the top surface of the squares. This passive actuation used a rack and pinion set along with a set of linkages to couple the z motion into motion of the grabber fingers.

During Phase 3, it was determined that this passive motion required too much downward force to reliably actuate and that there was an inherently high level of friction in the mechanism. The updated design for Phase 3 separates out these two motions with the pinching motion being accomplished with its own small linear pneumatic actuator while the lifting motion continued to be accomplished along with the plunge actuation.

USACE, Marine Design Center

35 March 19

Figure 52: Cable gatherer CAD design (left) and physical build (right)

4.0 MANUAL TIE GUN

The automated tying system’s goal is to have a highly reliable and consistent tying process for use in the matsinking operation. For any automated system, though, it is important to plan for the cases where the automated system is either unable to perform a tie (due to either square quality issues or fabric wire location) or the system detects that a tie that was performed needs to be re-done. Because of this, a critical part of the system is the development of an updated manual tie gun that human workers can use to assist the automated tying process.

In the current matsinking operation, manual tie guns are pneumatically powered and rely on mechanical timing mechanisms to control the timing process. The NREC team developed an updated manual tie gun that is electrically powered which reduces the infrastructure need for pneumatic cables along the mat deck.

The electric manual tie gun was developed to run off interchangeable batteries and have a weight comparable to the current tie guns in operation. The tie head components used for the manual tie gun are the same as what is used in the automated tie system with the exception that the rods are manually loaded into the tie head. Similar to the automated tie system, the manual tie system has sensors in the tie head to ensure that the tying mechanism is homed to a position in which the gears are open for fabric wires to enter the mechanism.

USACE, Marine Design Center

36 March 19

Figure 53: Manual Tie Gun in use on current matsinking barge along with current generation manual tie guns

The manual tie gun has been designed to drive the tie head assembly electrically. One of the larger challenges for the mechanism was understanding how to manage the heat dissipated when a tie is performed. In the legacy tie head, there was no need to dissipate heat energy since it was pneumatically operated and controlled. With the new design, the flow of heat was analyzed and managed using an internal fan to prevent air from being trapped within the protective case under continuous operation. The manual tie head design, as can be seen in Figure 54, manages the thermal load using a centralized fan. The airflow path, as can be seen in Figure 55, pulls in air from the center of the assembly and distributes air flow across the two hottest components – the motor/gearbox and the battery – since each have their own operational thermal limit.

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37 March 19

Figure 54: Internal design of the manual tie gun

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38 March 19

Figure 55: Airflow design within the manual tie gun

The tie gun was taken onsite to the matsinking unit to verify its operation before the final units for Phase 3 were fabricated and assembled. During these tests, the operation of the manual tie gun was verified to perform ties in four seconds over the course of performing 500 ties on site.

5.0 WINCH CONTROL PROTOTYPE

Two test setups were designed to confirm the control operation of the winches for operation on the matsinking unit. The first test setup confirms that tension between multiple traction winches can be equalized to mitigate high tension on a single launch cable. With all of the traction winches being connected with a common drive shaft on the current barge when there is a launch cable that undergoes high tension load there is no option to distribute that tension to neighboring winches to prevent a break of the overloaded cable. The second test setup simulates the mooring winches and confirms that the control system can move and position along a path even when having an external disturbance (simulating current).

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39 March 19

SIA OTA W15QKN-13-09-0001

5.1 TENSION EQUALIZATION TEST SETUP

The tension equalization test setup simulates how adjacent traction winches would operate under several loading conditions. For this test, a set of scaled winches were selected to confirm operation in place of full-size traction winches. These scaled winches are capable of full motion control and are able to handle a scaled load of up to 1000 lbs. Since winches have fleeting angle requirements that impact the design, an automatic spooling device was incorporated to reduce the angle requirement.

The full test setup features a total of five scaled winches. Three of the winches are used to mimic the operation of traction winches for launching operation. Those three winches have cables connected to a free moving sled. The connection point for the cable to the sled has a compliant spring in line that prevents the system from shock loading. This spring also dampens the response of the winches and more closely mimics the operational mode of the real traction winches since there will be a small delay in mechanical response between controlling the winches to reduce or increase tensions and when it is applied onto the system. Additionally, each winch has a tensionometer installed in line with the cable.

The winch cable is fed through this device which gives an output reading of both tensions and payout length.

The sled was designed to move freely on the ground. It has rails that interact with the ground and a sloped front edge that ensures that any dirt or rocks are moved out of the way as it is moved by the winches. A large water tank is installed onto the sled to allow for its weight to be varied. Increasing the weight in the sled will in turn increase the friction force that the winches need to overcome. At full load, the sled and water tank will require up to 800 pounds of pull force (assuming steel acting on gravel).

This is well within the capability of even a single scaled winch.

On the other side of the sled, two scaled winches are connected in a similar fashion. To mimic the actual operation of the traction winches on the barge, these two winches apply a tension load onto the sled to mimic the actual launching motion. The tension between these two winches can be varied to apply an uneven load on the three winches acting as surrogate traction winches. As the load winches pull the sled towards them, the control system will monitor the tension for each traction winch cable and normalize the load between the three traction winches, which are only able to payout their load.

USACE, Marine Design Center

40 March 19

Figure 56: Scaled winch assembly with auto spool used for both winch test setup

Figure 57: Design of tension equalization test set up

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41 March 19

SIA OTA W15QKN-13-09-0001

5.2 MOORING POSITION TEST SETUP

The mooring test setup uses the same scaled winches as the tension equalization setup. For this test setup three winches are spaced equally at three points of a triangle structure. The winch cable for each is connected to a center ring. The position of this ring can be controlled through the motion of each winch anywhere within a twenty-five-foot circle. A fourth winch will be used in one of several operating positions to add a load onto the center ring, mimicking current acting on the barge. The goal of the test is to move the ring in a way that can perform a desired motion path while compensating for the additional load of the fourth load winch.

Figure 58: Mooring winch positioning test setup design

6.0 CONCLUSION

This Final Phase 3 Report provided an overview of the prototyping work that was performed during this Phase of the project. The prototype systems that were described in this report were developed to analyze the high-risk areas of the Phase 2 design and to begin development of the control systems that are required for the final system implementation. All test results from the prototype testing will be presented under separate cover of a Phase 3 Functional and Safety Test Report. The test results will inform any design changes that are required for the Phase 4 prototype system that will be developed and tested.

USACE, Marine Design Center

Mat Plant Locating/Sensor Equipment Layout

LOAD CELL FOR

WIRE TENSION

FEEDBACK

4"

2"

4"

4"

NEMA 4

CONTROL

ENCLOSURE

31 2"

45 8"

4"

IN FEED FROM

WIRE ROPE SPOOL

WIRE ROPE

OUT FEED

THE DAVID ROUND COMPANY

CUSTOM TRACTION WINCH SYSTEM

MODEL: TWS-25-100

RUNNING LINE PULL: 25,000 LBS

RATED STARTING PULL: 31,000 LBS

SPEED: 10-100 FPM (2 - 20 IPS)

SYSTEM DETAILS:

LINE TENSION MONITORING UNIT •

(RESOLUTION T.B.D.)

INVERTER DUTY MOTOR WITH •

MOTOR BRAKE, INTERNALLY

MOUNTED ENCODER, AND

CONTINUOUS BLOWER

INCREMENTAL OR ABSOLUTE •

ENCODER AVAILABLE.

AVAILABLE ENCODER •

RESOLUTIONS (DEPENDING ON

ENCODER TYPE): 1024, 2048, OR

4096 PPR

VARIABLE FREQUENCY DRIVE •

WITH ANALOG AND DIGITAL

INPUTS & OUTPUTS. SUPPLIED

WITH ETHERNET IP

COMMUNICATIONS CARD

(OTHER OPTIONS AVAILABLE)

UNIT MOUNTED NEMA 4 •

CONTROL ENCLOSURE

DIRECTION & SPEED CONTROL •

SIGNALS BY OTHERS

SYSTEM INTEGRATION BY OTHERS•

CONCEPT DRAWING ONLY

ALL DIMENSIONS ARE FOR REFERENCE ONLY

DIM'S SUBJECT TO CHANGE

D

C

B

AA

B

C

D

12345678

8 7 6 5 4 3 2 1

THE INFORMATION CONTAINED IN THIS

DRAWING IS THE SOLE PROPERTY OF

THE DAVID ROUND CO. ANY

REPRODUCTION IN PART OR AS A WHOLE

WITHOUT THE WRITTEN PERMISSION OF

THE DAVID ROUND CO. IS PROHIBITED.

PROPRIETARY AND CONFIDENTIAL

DIMENSIONS ARE IN INCHES

TOLERANCES:

FRACTIONAL 1/64

ANGULAR: MACH 1 BEND 1

TWO PLACE DECIMAL 0.010

THREE PLACE DECIMAL 0.005

INTERPRET GEOMETRIC

TOLERANCING PER:

MATERIAL

FINISH

DRAWN

CHECKED

ENG APPR.

MFG APPR.

Q.A.

COMMENTS:

DATENAME

TITLE:

SIZE

B

DWG. NO. REV

WEIGHT:6790 LBSSCALE: 1:24

UNLESS OTHERWISE SPECIFIED:

WWD 6/21/2017

SHEET 1 OF 1

BRISTOL HARBOR

TRACTION WINCH

CONCEPT

DO NOT SCALE DRAWING

CONCEPT DRAWING