Engineers at Picatinny Arsenal are applying their expertise in software reliability to an advanced precision airdrop system designed to deliver vital supplies to the warfighter on time and in challenging terrain with minimum damage to cargo.
The Joint Precision Airdrop System, or JPADS, is intended to provide increased tactical maneuverability and enable a sustainment capability to support total Army, multi-service, and multi-national ground forces.
Moreover, JPADS meets a sustaining combat power requirement to provide high altitude, precision airdrop as a direct and theater delivery method into dynamic, dispersed, and unsecured battle scenarios.
The JPADS Air Vehicles are a family of high altitude systems offering weight capabilities of 500, 2,400 and 10,000 pounds.
The JPADS systems provide precision-guided capability for the accurate delivery of Container Delivery System (CDS) loads on to small drop zones from U.S. Air Force C-130 and C-17 aircraft flying at high altitudes and stand-off distances.
JPADS is especially helpful to Special Forces, but also has wider military applicability. The overall program has been a joint effort by the Army, Air Force and Marine Corps since 1997.
“We have worked with program partners to provide software engineering for challenging technologies used by the airdrop systems, resulting in an overall reduced cost and schedule for the program,” said Judy Mazeski, Precision Control Unit Software Branch Chief, Armament Software Engineering Center.
The software support at Picatinny is performed by the Armament Software Engineering Center, which is part of the larger Weapons and Software Engineering Center. Both organizations in turn belong to the Armament Research, Development and Engineering Center, or ARDEC.
ARDEC’s software expertise is in support of the Product Manager Force Sustainment Systems (PM (O-5) FSS) program office, part of the Program Executive Office for Combat Support and Combat Service Support.
The office encompasses the management of airdrop equipment for personnel, supplies and equipment in support of mass airborne assaults, resupply, special operations, deep strike concepts, and humanitarian relief.
The software engineering center at Picatinny focuses its support on the PM (O-5) FSS goals for improved accuracy and reliability of parachutes, increased payloads, improved safety, and increased operational flexibility.
The JPADS leverages and reuses the software application code and, to meet future upgrades, a common software architecture is used across all the JPADS variants.
“Software engineering requires the right solution is designed-in early in the development process,” said Devorah Burger, Team Lead, Armament Software Engineering Center. “It’s not effective to ‘bolt-on’ engineering solutions at the end of system development. Software engineering requires the right solution is designed-in early in the development process.”
JPADS provides Guidance, Navigation and Control (GN&C) capabilities unattainable by simpler airdrop technologies. These modernization efforts encompassed within JPADS include improving the accuracy and performance of JPADS in numerous challenging weather and terrain conditions.
SOFTWARE CREATION CHALLENGES
Some of the challenges of creating this software are:
— Weather conditions: The software must be sophisticated enough to make significant real-time adjustments to its guidance strategy to compensate for high or changing winds.
— Collision Avoidance: The system needs to be able to prevent collisions mid-air such as when multiple bundles are dropped in a single pass.
— Combination Drops: In the case where JPADS is dropped with jumpers in the same pass, the system must fly in a predictable manner, so the jumper can follow it to the point of impact.
— Terrain Avoidance: The software must account for variable terrain conditions. Dropping in a mountainous area is more difficult than dropping in a flat ground.
— Hazard Avoidance and airdrop estimation: The software must be able to determine the level of likelihood of a successful drop with hazardous conditions such as rivers and buildings. Also, the software must be able to adjust its flight path to avoid hitting any hazards within the drop zone.
— GPS-denied environments: Delivering payloads in an area where there is no GPS data available.
JPADS increases aircraft and payload survivability and enables delivery of multiple loads to single or multiple drop zones in a single aircraft pass with an accuracy better than 150 meters for the JPADS 2K system and accuracy better than 250 meters for the JPADS 10K system.
The JPADS airdrop vehicles include an air parafoil, with a glide ratio of 3:1, coupled with a military GPS-based Autonomous Guidance Unit (AGU).
The onboard Guidance, Navigation and Control (GN&C) software in the AGU autonomously steers the parafoil to the designated Impact Point (IP).
Onboard the aircraft, the JPADS 2K AGU is wirelessly integrated with the United States Air Force Mission Planner, which is used to monitor the health of the systems before flight and to determine an appropriate Launch Acceptability Region.
Just prior to landing, the AGU commands the parafoil to perform a flare maneuver and slow the system down for landing to increase load survivability.
The JPADS keeps warfighters and vehicles off the roads for resupply by utilizing Military GPS based, Autonomously Guided Navigation and Control systems, Steerable Parachute Decelerators, and Autonomous Operation and Waypoint Navigation.
WHAT THE SOFTWARE DOES
The JPADS Autonomous Guidance Unit (AGU) houses the battery power pack; GPS receiver; guidance, navigation and control (GN&C) software package; and the hardware required to operate the steering lines.
Prior to deployment, the AGU is programmed with a point of impact (PI), gross rigged weight of the system, Digital Terrain Elevation Data (DTED), canopy type as well as the elevation of the PI. The system uses these inputs to calculate a projected trajectory.
The JPADS 2K AGU continues to calculate its position via the GPS throughout descent, landing near the PI with an accuracy better than 150 meters with an 80 percent confidence
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The steerable parafoil is called a “decelerator,” and gives the JPADS system directional control throughout its descent by means of decelerator control lines attached to the MAGU.
They create drag on either side of the decelerator, which turns the parachute, thus achieving directional control and allows the JPADS system to land near the PI, even though it is released at a high standoff distance.
The Mission Planner software gives the aircrew the ability to plan the mission, in flight if necessary, as well as providing a Computed Air Release Point (CARP), where the load is released.
CONTINUOUS IMPROVEMENTS
JPADS software has been improved throughout the time that ARDEC has supported the program.
In addition to accuracy improvements, the software has been updated to included user selectable flight software navigation strategies.
These strategies allow for normal operations, landing on an IP in a mountainous area, as well as a predictable flight strategy for combination drops when jumpers are going to be following the bundle.
Additionally, the software has helped reduce the chance of collision between bundles and increased payload survivability.
Future research may include camera-based navigation, which can be potentially be extended for use on an autonomous vehicle, manned aircraft, and unmanned aircraft. Vision-based software technologies compares what the camera sees with the latest satellite images of the ground target area to determine the drop zone.
That means a vision-based JPADS could provide a capability that autonomously steers the cargo delivery to the target without requiring outside signals or information, such as GPS.
ARDEC’s Precision Control Unit Software Branch will ensure that every armament solution delivered to the warfighter is designed from the start with the most effective, adaptive and maintainable solutions.
ARDEC expects growth in the Precision Guided Engineering competency due to emerging and evolving threats.
Filed Under: Aerospace + defense
