TECHNICAL TASK (written by six)
Development of a turnkey interactive projection system with software for 6 mm Airsoft shooting
(similar to the airsoft digital target system Arcada; https://youtu.be/3HwgDuesDTU?si=vZCKD4pZDXtL3kZl)
An engineer or a small team with experience in DSP / DAQ / acoustics / vibration measurements / piezoelectric sensors / impact localization is needed.
1. Overall project goal
A prototype of an interactive shooting game system is to be developed for use in entertainment centers.
Operating principle:
An interactive image or game is projected onto a physical screen by a projector. The user shoots at the screen with standard Airsoft guns using 6 mm BB plastic balls.
The system must determine the coordinates of each physical hit on the screen in real-time and transmit the X/Y coordinates to the software.
The software matches the physical hit point with the object currently displayed by the projector, after which the game responds accordingly to the shot.
The main task of the first stage is to create a reliable technology for determining hit coordinates.
2. Size of the first prototype
Working area:
1000 × 1000 mm.
After successful testing, the technology should be scalable to larger screens, approximately:
2000 × 1200 mm;
2400 × 1350 mm;
or other commercial formats.
Therefore, the system architecture must consider further scaling.
3. Type of ammunition
Main type:
Airsoft BB — plastic balls of 6 mm caliber.
The system must operate with standard Airsoft guns within a safe energy range for the entertainment venue.
The specific allowable range of speed and energy of the BBs must be determined experimentally during development.
4. System operation principle
Basic concept:
Shot → BB impact on the screen → impact registration by sensors → signal processing → X/Y coordinate determination → event transmission to the game software.
For example:
SHOT #00125
X = 643 mm
Y = 271 mm
Timestamp = ...
Confidence = ...
The coordinates must be transmitted to the software via API, SDK, TCP/UDP, WebSocket, or another stable interface.
5. Screen design
A metal impact surface is considered for the first prototype:
an aluminum or polycarbonate panel approximately 1000 × 1000 × 1 mm.
Thickness, alloy, and mounting design are NOT final.
The engineer must experimentally determine the optimal:
material;
thickness;
tension/fixing method;
damping;
frame design;
sensor placement.
It is important to ensure:
stable propagation of mechanical/acoustic waves;
sufficient durability under repeated impacts;
the possibility of quick replacement of the impact panel;
minimal impact of the mounting on the accuracy of coordinate determination.
6. Sensor system
Approximately 4–8 or more sensors are planned for use.
Possible technologies:
IEPE/ICP piezoelectric accelerometers;
contact acoustic sensors;
piezoelectric sensors;
ultrasonic methods;
other technologies proposed by the engineer.
The number and type of sensors should be determined not formally, but based on the best accuracy, speed, reliability, and cost of the serial system.
Preference is given to ready-made professional components from existing manufacturers.
There are no plans to develop proprietary electronic boards if the task can be reliably solved with ready-made serial equipment.
7. Coordinate determination
An algorithm for determining the coordinates of physical hits must be developed.
Possible methods:
Time Difference of Arrival (TDOA);
wave arrival time analysis;
amplitude analysis;
signal shape analysis;
frequency analysis;
correlation methods;
calibration surface map;
machine learning;
combination of several methods.
The engineer may propose another technology if it provides better results.
8. Accuracy
The desired final accuracy of coordinate determination:
approximately ±5–10 mm across the entire working surface.
For the first prototype, an acceptable intermediate result may be:
up to ±20 mm, if there is a clear technical path to further improve accuracy.
It is necessary to measure:
average error;
maximum error;
error near the edges;
repeatability of results.
9. Speed of operation
Hit determination must occur almost instantaneously.
Desired latency:
less than 10–20 ms from physical impact to coordinate transmission to the game, if technically possible.
The system must recognize a series of rapid consecutive shots.
In the future, support for multiple players and high shooting intensity is required.
10. Simultaneous and close hits
The possibility of correctly processing must be investigated:
rapid consecutive shots;
two hits with a small time interval;
potentially simultaneous shooting by two players.
The algorithm must not mistakenly combine two different shots into one hit.
11. Calibration
The system must have a procedure for automatic or semi-automatic calibration.
For example:
a grid of control coordinates is set on the screen.
A series of test shots is performed at known points.
The system records signals from all sensors and creates an individual calibration model for the specific screen.
Calibration must compensate for:
differences between panels;
mounting features;
wave reflections from edges;
differences between sensors;
temperature and mechanical changes, if they significantly affect accuracy.
12. Self-diagnosis
It is desirable to provide for automatic checks of:
the operability of each sensor;
signal level;
absence of cable break;
the need for recalibration.
In case of malfunction, the system should report which specific component needs checking.
13. Projector
At the next stage, a projector will be connected to the system.
The projector will display:
moving targets;
arcade games;
training scenarios;
scoring system;
multiplayer scenarios.
Hits must accurately correspond to the projection coordinates.
Software calibration must be provided:
physical screen coordinates ↔ projector image coordinates.
14. Game software
At the first stage, it is not necessary to develop full-fledged games.
A test program is needed that shows after a shot:
hit point;
X/Y coordinates;
shot number;
time;
error relative to the control point;
service information about sensor signals.
In the future, the system should have the capability to integrate with a game engine, such as Unity or Unreal Engine.
15. Equipment
Priority:
use of ready-made professional serial components.
It is necessary to avoid developing proprietary complex electronics if reliable ready-made solutions exist.
Components from manufacturers of the level are considered:
professional data acquisition systems DAQ;
IEPE/ICP and other industrial sensors;
ready USB/Ethernet interfaces;
serial cables and connectors.
No specific manufacturer is fixed.
The engineer may propose optimal components.
16. Prototype budget
The estimated budget for the sensor system and main equipment of the first prototype:
up to 5,000 USD.
PC and professional projector may be considered separately.
It is important to find a balance between:
accuracy + speed + reliability + possibility of serial production.
17. Commercial operation
The final system is intended not for a laboratory but for daily commercial operation in an entertainment center.
Therefore, the equipment must:
operate many hours daily;
withstand a large number of shots
We can provide premises for the development and release of this project in the city of Lviv with the prospect of continuing activities as a partner
