PARACHUTE MISSION PLANNING, TRAINING AND REHEARSAL USING A DEPLOYABLE VIRTUAL REALITY SIMULATOR

Jeffrey R. Hogue*R. Wade Allen†

Systems Technology, Inc.Hawthorne, California, USA

Steve Markham††Valentine Technologies, Ltd.

Odiham, Hampshire, UK

Arvid Harmsen‡‡A&A

Huizen, Stuurboord, The Netherlands

Jerry MacDonald‡Cliff Schmucker**

SSK Industries, Inc.Lebanon, Ohio, USA

ABSTRACT

This paper describes a device and method for planning, training, and rehearsing tactical parachute insertion missions. This concept is based on a low cost, virtual reality parachute simulator that has evolved over the years to train a wide range of jumping tasks encountered by smokejumpers and special operations personnel including chute deployment, malfunctions, maneuvering, and landing.

Recent advancements allow for several jumpers to be networked together for coordinated jumps, and the simulated use of a GPS navigational aid system. This paper discusses the evolution of the simulator capabilities for a range of jumping tasks and situations, including recent enhancements for mission rehearsal and networking.

* Principal Specialist, Senior AIAA Member† Technical Director, AIAA Member‡ Project Engineer** President,†† Technical Director‡‡ Technical Director

INTRODUCTION

Parachute simulation began as a method to provide training to improve the safety and performance of smokejumpers (forest fire fighters) more than 15 years ago; Success with this concept led to use by military parachutists 1,2 to teach parachute guidance and control from deployment through to landing. As this training concept has been widely adopted by these units, very widespread adoption and application of this training concept to aircrew emergencies3,4 motivated further improvements.

Developments made to support requirements for these new areas have then been reapplied to simulation systems directed at military operational mission planning and rehearsal and firefighting parachuting5,6. The specifics of these enhancements are addressed in this paper, which also details how the system has advanced from simply teaching parachute flight control to complete operational procedures and mission planning and rehearsal.

Currently a parachute simulation may start in simulated free fall, with a parachute being deployed manually by ripcords, by static line, or by an Automatic Activation Device (AAD) At high altitudes, the Head Mounted Display (HMD) blacks out until oxygen is activated. In Figure 1, the main ripcord for a simulated MT-1X has been deployed.

17th AIAA Aerodynamic Decelerator Systems Technology Conference and Seminar19-22 May 2003, Monterey, California

AIAA 2003-2156

Copyright © 2003 by Jeffrey R. Hogue. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.

The first priority of the jumper is to look up and visually check the canopy for proper deployment; these head motions are detected with a tracking device and the program computes a display that is appropriate for the direction viewed; this then is providing the experience popularly termed virtual reality.

The parachutist can mitigate against various simulated malfunction selections, cutaway the main if required and deploy a reserve parachute (for operational parachutists), then exert guidance (with GPS optional) (Ref 8) using instrumented and force loaded parachute controls through to landing, while operating in conjunction with other jumpers through networking. The results of this synthetic experience are automatically scored and replays are immediately available for critique.

Figure 1. Main Ripcord Deployed

A range of visual databases is available for selection for a given jump, and methods have been developed on a SOCOM Phase II Small Business Innovative Research (SBIR) Contract to allow rapid preparation of visual and wind field databases for rehearsal of specific mission objectives. This process for developing mission rehearsal visual and wind scenarios incorporates available digital terrain profiles, satellite or aerial photographic imagery of ground terrain and weather information. The simulator has also been interfaced with a commercial GPS navigation device designed for parachuting, which allows training in the use of this equipment for guidance and navigation. This simulator to GPS guidance system is described in this paper.

BACKGROUND

A clear distinction can be made between those aircrew forced by circumstances to jump or fly parachutes, and those personnel who make premeditated operational jumps. However In both situations, critical procedures, equipment, control, navigation, and emergency correction skills must be learned, mastered, and then exercised during highly stressful circumstances. These needs have been historically met through lectures in classrooms and while simply hanging in a parachute harness.

Professional aircraft flight simulators have traditionally required complex dedicated systems developed for individual, small-quantity applications. As a consequence, these devices were extremely expensive to acquire and maintain, but are seen as essential for personnel to safely and proficiently operate expensive flight vehicles. Parachutes are extremely inexpensive flight vehicles and thus were seen as not meriting the steep costs of flight simulation based training, despite the large financial burden of aircrew training acquisition and maintenance, and political consequences of losses of aircrew and operational personnel, as well asmission failures.

This disparity was originally addressed by Systems Technology, Inc. (STI) using Personal Computer (PC)-based hardware and software originally developed for emulation of dedicated Computer Aided Design (CAD) workstation hardware and software. More recent rapid advances in PC graphics and networking based on OpenGL and DirectX computations have been exploited in parachute simulator versions to provide improved face validity and additional training features. Cost remains the dominant consideration for acquiring and applying these training devices. To satisfy this requirement, costs were minimized by hardware design that adapts existing technologies rather than creating completely new and unique designs as much as possible. This has resulted in a design which is robust and general purpose, benefiting from orders of magnitude cost reduction through economies of large scale application and commercial off the shelf technology.

While software programming has to be specific to the particular training task requirements of parachuting, the tools selected to produce it are again chosen from the large array of general purpose commercial products now available, such as Microsoft Visual Studio, 3D Max, etc. Many computation-intensive graphics techniques that were restricted to a very limited population of high-end, application-particular flight simulation systems are now commonplace in PC-based graphics methodology, and development tools are also readily and inexpensively available on a commercial basis.

SUSPENSION FRAMES

Suspension Frames are a good example of the cost efficiency benefits of adapting large-application based technology to the limited potential parachute simulation market. Riser force inputs for malfunctions clearing and steering control, together with the shock loads from Personnel Lowering Device (PLD) training, and concerns expressed by military unit safety officers, produced the need for a economical but rigid suspension frame design based on extremely sturdy industrial shelving components capable of loads of several tons, as shown in Figure 2.

Figure 2. Suspension Frame Based on Industrial Shelving Components

While this system carries a duty rating of 300 lb., it actually vastly exceeds applicable OHSA Standards29 CFR 1296.451 and 1910.28 requirements, and does not need to be fastened to the floor, wall, or ceiling.

Other frame systems are based on sturdy commercial scaffolding components, as shown in Figure 3, or balcony railing materials. A motorized version of the latter design is shown in Figure 4. and a transportable 2X2X3 meter version that stores in a 2 meter long narrow tube is shown in Figure 5.

Figure 3. Suspension Frame Based on Industrial Scaffolding Components

Figure 4. Motorized Suspension Frame Based on Balcony Railing Components

The transportable version is particularly beneficial in that it can easily be deployed with an operational unit to a site location suitable for staging tactical operations. The rapid production of simulator scenes facilitates simulator scene refinements as data becomes available shortly before an operation.

Figure 5. Tube Transportable Suspension Frame

As can also be seen in Figure 5, the controller box has been reduced to one third the standard size, and the system can be operated from modern laptop computers with advanced NVidia or ATI graphics capability and auxiliary PCMCIA graphics and signal interface cards.

A frame enhancement has been developed which attaches to the bottom of the parachute harness with a standard 3-ring release. For good opening parachutes, one part of a 2 line main ripcord is then routed though this release, and the other part is routed through the main ripcord sensor. The simulator jumper is pulled up to a horizontal position as shown in Fig 6. When the ripcord is pulled, the simulated parachute opens and the jumper feels himself moving to a vertical position.

When a high speed malfunction is selected by the instructor, one part of a 2 line reserve ripcord is then routed though the harness pull-up bottom release, and the other part is routed through the reserve ripcord sensor. Thus in this case, when the jumper pulls the main ripcord, he stays physically horizontal, but when he pulls the reserve, he physically moves from a horizontal to vertical position.

Figure 6. Horizontal Start Frame

Mission Planning and Rehearsal with Geo-Specific Scene Features

Personal Computer (PC) based mission planning software has been improved by the development, acquisition, and open distribution of a large amount of digital terrain data, and aerial and satellite photographic imagery. As this data became available, a number of PC-based software tools have been developed by several companies which automate the rapid development of simulator scene databases. As the time and effort required to develop scenes to simulate specific geographical locations was reduced from man-years to man-hours, it became possible to transition the use of simulators such as the parachute from purely flight control training to mission planning and rehearsal.

This new version has been developed under contract from the US Special Operations Command (SOCOM) to enable the rapid generation of real world scenes based on digital terrain, photos, and weather data. This process has ported the current version to an implementation with a more modern graphics user interface (GUI), much better compatibility with modern PC hardware, and which incorporates networking so that actual (rather than simply pre-recorded) interaction between parachutists will occur. Figure 7 shows ram-air jumpers jumping above a scene replicating a desert area near Yuma Arizona.

Figure 7. Yuma Arizona Desert Scene

Figure 8 Wind Field Data Graphics from Weather Forecasts and Digital Terrain Database

Figure 8 shows an example 3D wind field computed from weather forecast data and the simulator digital data terrain base.

NETWORKED GROUPED OPERATIONS

The networked version of the mission planning system consists of a set of networked Jump Stations, a Master Controller, and a Scenario Developer consisting of a Visual Scene Generator and a Wind-Field Generator. A conceptual sketch of this network is shown in Figure 9. This system provides the ability to simulate group parachute insertions using networked simulators and multiple users. They can operate either independently in a stand-alone mode or in a networked mode for group jump simulations. In stand-alone mode, each Jump Station operates much like the basic training system, running and recording jumps independently of the other stations and the Master Controller. Each station stores its own copies of all data required for independent simulation operation.

In networked mode, large numbers (12 demonstrated) Jump Stations can operate together, controlled by the Master Controller. It receives scenarios and information about other networked

jumpers from the network and displays them in the HMD and the Jump Station display monitors (optional), permitting a jumper to interact with others in a live, networked jump. In this mode, the Jump Station does not require a simulation operator; all operator commands are made at the Master Controller and relayed to the individual stations. Each Jump Station receives graphics updates from the Master Controller during the jump. Fig 9 illustrates the network communications flow.

When a group jump is not in progress, each Jump Station in networked mode is available for distributed computing activities such as wind field calculation and scenario graphics generation. As each Jump Station must be able to run in stand-alone mode, each Station has a simulation computer, keyboard, mouse, display and instructor's monitors, jump harness, head-mounted display and head tracker. Each Jump Station, when in networked mode, receives data from and transmits data to the other networked Stations and the Master Controller, so that jumpers can interact in a single scenario. A jumper at a given station in network mode can “see” all other jumpers currently operating in network mode.

Figure 9. Mission Planning and Rehearsal Network Conceptual Sketch

The key to running multiple Jump Stations in networked group mode is the Master Controller. The Master Controller is able to run the parachute simulator software in stand-alone mode, to allow the mission coordinator to select and verify scenarios and view them for mission planning and rehearsal preparation, as well as for multi-jumper run review. The Master Controller issues commands to available Jump Stations, specifies scenarios and starting conditions, and tracks all data output by each Station. It provides graphics updates to all Stations throughout multi-jumper runs.

The Master Controller is able to review all networked jumps, both by individual Jump Station, and as multi-jumper runs. A variety of real-time viewing options is available to provide the jump coordinator maximum flexibility for mission planning and rehearsal. The Master Controller also has a variety of review modes which can be rerun on the Master Controller' monitor or issued to any or all networked Jump Stations. These reviews include overall group jump review (observer's view of all participating jumpers) and review from any selected Jump Station's perspective. The Master Controller can also replay a jump over the network with each participating Station reviewing the jump from its own perspective.

The Master Controller will select the visual database and an available wind field correlated to the selected scenario terrain. Each scenario will have a unique set of terrain-correlated wind fields. The Master Controller will transmit scenario data to all Jump Stations running in networked mode. This includes the VR environment, the generated wind field, starting altitude, jump order, and other initial scenario conditions.

The Jump Stations and Master Controller can be installed on modern laptop computers, as shown in Figure 10 which together with the Figure 5 transportable frame can be moved to a jump staging area and thus available for last minute tactical reviews, planning, and practice.

Figure 10. 2 Jump Stations and Master Controller Laptop Computers

GPS Guidance and Mission Planning

OPANAS (Operational Parachute Navigation System) is a GPS, altimeter, and magnetic compass based guidance system originally developed by NAVOCAP S.A. and enhanced by SSK Industries for use by HAHO (High Altitude High Opening) jumpers. The parachutist views position, altitude, and relative position to the target. Prior to the mission, the guidance system is programmed with course data derived from target coordinates, forecast wind aloft data and canopy performance information, and displays in moving map format a flight path and the real-time position of the jumper. Figure 11 shows the OPANAS displays.

Figure 11. OPANAS Navigation Display and Compass

Mission Management Planner (MMP) is a SSK software program that runs on a PC computer (typically a laptop which can be attached to the guidance system) that permits complete HAHO mission planning. Mission information is entered into the program, including target coordinates and elevation; forecast wind data and canopy performance. An exit area is calculated and displayed on the mapping program. This program and computer is also used to program the guidance system. Figure 12 shows a typical display.

Figure 12. Mission Management Planner Display

Field reports from HAHO troops had indicated that the logistics and expense of practicing HAHO jumps limit the training available. Less than acceptable results are obtained when the jumps are performed in practice or actual insertion activities. STI and SSK addressed this problem by developing a system, which combines the OPANAS and Mission Management Planner with the STI ParaSimparachute training simulator to enable HAHO troops to fly simulated missions using realistic wind, meteorological and terrain information. Figure 13 shows the data flow between the components of this combined system. Figure 14 shows the OPANAS in use and attached to a parachutist participating a simulated rehearsal mission based on the parachute simulator.

This system permits multiple practice flights to be completed prior to an actual practice jump or

mission. In the case of mission training, the MMP also programs the parachute simulator. The MMP is used as a control panel during simulated training missions; this allows the instructor to vary certain simulated conditions during mission planning, such as adjusting the winds aloft from the forecast values. The instructor can also monitor on the MMP the path followed by the jumper in real time during simulation.

Conclusions

Use of a parachute simulator has progressed from its origins as a part task flight control training device

to a complete mission planning and rehearsal system capable of using digital terrain data, aerial and satellite photography, and weather forecasts to generate synthetic scenes which replicate operational situation predicted to be encountered. As much as possible, this system is designed with readily available Commercial-Off-The-Shelf (COTS) technology to minimize costs. Versions can be readily field deployed.

MMPComputer OPANAS

ParaSimComputerJumper

TogglesRisers

RipcordsHead Tracker

3D Scene

TimePositionHeading Programming,

Simulated Data:GPS, Altimeter,Magnetometer

Exit PointTarget Location

Winds AloftCanopy Performance

HeadingMoving Map

Figure 13. Combined System Data Flow Diagram

Fig 14. OPANAS in Use During an Parachute Simulation

REFERENCES

1. Hogue, Jeffrey R., Johnson, Walter A., Allen, R. Wade, Pierce, Dave, A Smokejumpers' Parachute Maneuvering Training Simulator, AIAA-91-0829, American Institute of Aeronautics and Astronautics 11th Aerodynamic Decelerator Systems Technology Conference, San Diego, California, April 9-11, 1991

2. Hogue, Jeffrey R., Johnson, Walter A., Allen, R. Wade, Pierce, Dave, Parachute Canopy Control and Guidance Training Requirements and Methodology, AIAA-93-1255, RAes/AIAA 12th Aerodynamic Decelerator Systems Technology Conference, 10-13 May 1993, London UK

3. Hogue, Jeffrey R., Frederick G. Anderson, Cecy A. Pelz, R. Wade Allen, Steve Markham, Arvid Harmsen, Parachute Simulation Enhancements for Post-Ejection/Egress Training, 36th Annual SAFE Symposium, September 14-16, 1998, Phoenix, AZ.

4. Hogue, Jeffrey R., R. Wade Allen, Cecy A. Pelz, Steve Markham, Arvid Harmsen, Methodology and Improvements in Aircrew Parachute Descent Virtual Reality Simulation Training, 39th Annual SAFE Association Symposium, October 9-11, 2000, Reno, Nevada.

5. Hogue, Jeffrey R., R. Wade Allen, Jerry MacDonald, Cliff Schmucker, Steve Markham, Arvid Harmsen, Virtual Reality Parachute Simulation for Training and Mission Rehearsal, AIAA2001-2061, 16th AIAA Aerodynamic Decelerator Systems Seminar and Conference, May 21-24, 2001, Boston, Massachusetts.

6. Hogue, Jeffrey R., R. Wade Allen, Cecy A. Pelz, Jerry MacDonald, Steve Markham, Arvid Harmsen, Virtual Reality Parachute Simulation for Training and Beyond, STI P575, Parachute Industry Association Symposium, January 30 -February 2, 2001, San Diego, California.

7. Jerry MacDonald, On-Target System for HAHO Jumpers, presented at the Parachute Industry Association Symposium, January 30 - February 2, 2001, San Diego, California.

9. Brown, Glen, Haggard, Roy, Almassy, Richard, Benney, Richard, Dellicker, Scott, The Affordable Guided Airdrop System (AGAS), AIAA-99-1742, 1999 Parachute Industry Association International Symposium, January 10-14, 1999, San Diego, California.

10. Headquarters, Department of the Army, Special Forces Military Free-Fall Parachuting, US Army Training Circular No. 31-19, 9 September 1988