VIRTALIS created Virtual Reality (VR) trainers for the Royal Navy’s 7.62 mm General Purpose Machine Gun (GPMG) and the 20mm GAM BO1 and 30mm MKI weapons.
GUNNERY SIMULATOR
The amount of training necessary to ensure that weapon systems are used efficiently and correctly is considerable. However, there are pressures on training establishments in the UK to justify increasing manpower resources and counteract the spiralling cost of ammunition.
Following the closure of the coastal firing range at HMS Cambridge near Plymouth (UK) in March 2001, 20/30mm and GPMG naval weapons students are trained using a simulation facility at HMS Collingwood near Portsmouth. Using VR techniques, including the latest head-mounted display technology, weapons students are able to undertake realistic firing exercises, engaging targets as if located on an actual Royal Navy vessel.
THE VR GPMG TRAINER
The VR GPMG trainers utilise an inert version of the actual weapon, so students continue to handle equipment that has a “look and feel” of the real operational setting. Even the sounds of the weapons are similar to those experienced in reality, as the student is played real-time recordings of ordnance discharge from stereo speakers. Perhaps the only difference between VR and real life firing is the lack of recoil, although this is simulated visually.
The focus of the trainers is not only accuracy, but safety and the observance of the correct rules of engagement. However, the accuracy of the ballistics within a target range of 50 to 200 metres and at a rate of fire of between 700 to 900 rounds per minute, means that the students’ marksmanship has demonstrably improved. Unlike real-life practice, the PC-hosted VR trainers have a playback feature, which enables the instructor to analyse the students’ performance.
TRAINING SCENARIOS
The GPMG VR trainer has two modes – transit and stationary. The transit version takes the form of the view from a ship sailing down what is described as a “Suez Canal-type environment” for about six minutes.
During this time, up to 50 animated figures can appear, together with moving trucks and speedboats. The students must use the visual information presented to them to decide whether to open fire or not. All the figures are animated. They fall to the ground when hit and the sound of their weapons can be heard when they return fire.
The VR GPMG closely represents of the ballistics of the gun, its speed, direction and rate of fire. All the visuals are projected onto a screen 3.6m wide and 2.7m high positioned about 7m in front of a fully operational GPMG. Virtalis developed its own especially rugged tracking system for the VR GPMG in order that the movements of the gun are followed accurately.
By means of a specially designed computer interface, Close-Range Weapons Simulator instructors can design and save a variety of training scenarios by using simple mouse and keyboard inputs. Hostile platforms (aircraft, surface vessels and missiles) can be programmed to approach the student’s “own ship” from different bearings and ranges, and at different heights and speeds.
Friendly and neutral aircraft or vessels can also be introduced into each scenario. Once the instructor has introduced a particular threat, it is then possible to program its future route or profile by inserting one or more waypoints.
Each waypoint can be associated with a change in direction, height or speed, thereby endowing the platforms with realistic behaviours. Quite complex scenarios can be generated in this fashion, with aircraft and ships even releasing missiles at certain points during their pre-programmed profiles.
SPECIAL EFFECTS
During the training exercise, these pre-programmed behaviours are displayed via Head Mounted Displays to the student 20/30mm weapon aimers and, for simple tracking training, via a video projector to students manning a general-purpose machine gun (GPMG).
The view through the aimer’s HMD is that of a virtual weapon emplacement on the starboard side of their own ship. The environment in which the scenario takes place can itself be programmed to include sea states from zero (calm) to six, mist and fog levels, time of day and rain effects.
In addition to the weapon aimer’s position, two trainee Weapon Directors Visual (WDVs) stand on a purpose-built Gunner Director’s Platform (GDP) within the HMS Collingwood simulator facility. The WDVs are also equipped with HMDs, each having been modified by the addition of a small switch.
Pressing the switch magnifies the view available to the WDV, thereby simulating the use of binoculars. Calling out and acting on instructions, the WDV and weapons aimers interact to engage incoming targets. The position and orientation of the weapons and HMDs are tracked in real time using InterSense’s IS-900 tracking systems.
On firing the virtual 20/30mm weapon, realistic barrel motions can be seen, together with smoke, tracer and ammunition belt feed effects. Successfully destroyed aircraft explode and fall into the sea. Sound effects have also been provided, including weapons discharge and an ambient, background naval vessel noise. Once a scenario has been run as a training exercise, it can be replayed by the instructors for debrief purposes.
THE BENEFITS OF THE VR TRAINER
Warrant Officer Bob Bainbridge of HMS Collingwood commented: “The advantages of VR training are numerous. Not only can we help to reduce the environmental pollution caused by spent ammunition, but there are other major benefits, including a major reduction in expenditure on live ammunition, no need to air-tow targets and no reliance on the weather. In the year prior to the inception of the 20 and 30 mm VR trainers, the Royal Navy spent £1.5 million on live rounds. Naturally, as there is almost no cost associated with the use of Virtalis’s trainers, we were able to fire approximately 30 times more rounds in the first year of operation and this is set to rise with the addition of the VR GPMG trainer. This kind of intensive training is no longer seen as extravagant, but good, cost-effective practice.”