The security system must detect threats as early as possible - that is a fundamental security rule.If you have an outdoor area around your home, outdoor detectors should be installed there.To detect an intruder before a door is opened or a window is broken, he must activate the sirens and give a head start to the security company or police crew on duty.This significantly increases the chance of preventing damage and protecting people's health and lives.

The protection of a territory can be implemented in two ways.If the house is fenced and the outsiders are not allowed to enter, motion detectors with a wide horizontal viewing angle and detection range are used.This was exactly the device Ajax used to launch its line of outdoor security devices: MotionProtect Outdoor .Otherwise, in the cases where the detection zone needs to be limited, curtain detectors are used.They detect movement in a narrow area so that no one can approach a door or window, enter a terrace or climb onto a balcony unnoticed.They use an invisible curtain to shield the area where people can move freely.

Wireless Ajax MotionProtect Curtain Motion Curtain Detector

In March 2019 we presented Ajax's first curtain - MotionProtect Curtain .In this article we will talk about everything that preceded the release: the decision about the capabilities of the new product; the reasons for the development of two unique optical systems; the possibilities of the ZOE algorithm; and prototyping and testing that ensures the highest accuracy of human detection.

 

MotionProtect curtain

Motion detector for wireless outdoor curtain with anti-masking and pet immunity.

An uncompromising "curtain"

Customers and partners from Italy, Spain, Portugal, France and other countries of Southwestern Europe were the initiators of the release of the new device.In these countries, panoramic windows and terraces that can be used for secret burglaries are very popular.To reduce the risk of burglary, the exterior of a building is protected with small-angle motion detectors.In addition, "curtains" protect the valuables in the buildings: safes, document safes and works of art.We used these solution scenarios as our springboard.

Before we started developing the MotionProtect curtain, we conducted extensive market research: the technologies and capabilities of the leading market players; the expectations of security professionals and users; the areas where a technological or functional breakthrough can be made.

We found that the best representatives of this class of detectors were equipped with anti-masking systems and some of them were able to operate for a long time with batteries.But in terms of range and reliability of communications, no device could compete with Ajax devices.Most curtain detectors were unable to distinguish a pet from a person and could at best ignore natural interferences: heated air currents, swaying leaves, etc. Only one manufacturer offered detectors that were immune to animals.

That was a challenge! Our MotionProtect Curtain Curtain Detector should identify people 100% accurately and prevent them from reacting to interference and reduce reactions to animals as much as possible - regardless of the site conditions, you should be able to rely on the warnings.Effectively identifying masking when the risk of outdoor tampering is high.Have been working together for years on bundled batteries and always maintain a connection - Ajax customers are used to the reliability and ease of maintenance of our equipment.Meanwhile, it should be compact and have a great design that looks nice both outdoors and indoors.

A unique motion detection system

Motion detection system is the most important element of the curtain detector.The simplest detectors use only a single PIR sensor and an optical focusing element: a mirrors or a Fresnel lens.More expensive models are equipped with an additional microwave sensor to filter out natural interference.

We started development by testing the capabilities of these technical solutions.The components of the Ajax motion detectors use MotionProtect and MotionProtect Plus, we have put together test benches.Without the bodies or connection to the hub - just the most essential hardware to collect information about the events happening in a small field of view.In the laboratory we simulated everything a curtain detector might encounter at the actual location: warm air currents, moving animals, birds, bushes and grass swaying in the wind, normal (and even strange) human behavior.We then investigated what triggered our test benches and how they 'saw' these events.The results of a single PIR were deplorable.A system consisting of a single PIR sensor and microwave sensors with a horizontal viewing angle of 6° can provide maximum protection against natural interferences, but may not differ from human to animal.

Our "curtain" had to be able to receive more information about the events in the detection zone.That's why we chose the approach used in the motion detector Outdoor MotionProtect Outdoor : the system consisting of two PIR sensors.Only they were not narrow multidirectional "beams" but rather discrete "fan-shaped" zones:

After assembling new test benches, the developers simulated the behavior of people, animals, birds and all kinds of natural disturbances in the laboratory.They changed the ambient temperature, studied the effect of speed and direction of movement, and then analyzed the data collected by the sensors.The results were promising! We now had a prototype of the optical system that would allow us to develop pet immunity.

Ajax MotionProtect Curtain early prototype

But it was impossible to buy components for it.While curtain detector optical systems based on PIR and microwave sensors were commercially available, paired Fresnel lenses that projected infrared radiation onto two PIR sensors simultaneously were not commercially available.To develop the curtain detector we invented, we had to create a new optical element, and that also meant establishing its production.

We solved this daunting task through Ajax Systems' R&D department.If we had hired a contractor, the project would have been put on hold for several months.Because it was important that the device was compact, we opted for a focusing mirror.We calculated the number, area and orientation of the 10 planes placed on two panels - one for each PIR sensor.We had to walk the entire path from the design of optical elements using specialized software and perfectly polished metal models to batch production of parts with a special mirror coating.We then built test benches using the new optics and tested the system in action: on people, animals and disturbances typically found outside and inside buildings.

Segmented mirror of the MotionProtect curtain detector

Four months after developing the new detector, we had a suitable optical system.It offered a horizontal viewing angle of 6° and could detect motion at a distance of 11 meters.And most importantly, it collected enough data to distinguish a human from a pet or a bird and minimize the chance of false alarms caused by natural events.

Professional protection against tampering

In addition to developing the motion detection system, we were also working on combating masking.This is a typical tampering tactic used with outdoor security systems: block the view of motion detectors (by covering or painting the lens) when the system is inactive and then break into the protected premises unnoticed.Our curtain detector had to be able to detect such threats.The small size of the body and the limitations in power consumption did not allow the placement of multiple IR illuminators and mask sensors (there are three in MotionProtect Outdoor), so we had to think outside the box again.

For the MotionProtect Curtain curtain detector, another unique optical system has been developed that separates the infrared radiation from a single source into two streams: one detects the emergence of an object in front of the detector (cover) while the second detects the painting of the body with a transparent varnish.In this way, continuous detection of masking consumes very little electrical power without having a significant effect on the autonomous operating time of the device.

The tamper unit does not allow a disabled detector to be secretly dismantled

The detector was also equipped with two tampers: the first responded to the opening of the body and the second responded to attempts to dislodge the device from the SmartBracket mounting panel.

Combined with frequent polling of the detector by the hub that can identify the loss of communication with the device in less than a minute, these systems provide 100% protection against tampering.

From test bench to detector

The next generation of prototypes can already be called Ajax detectors.Still without a body, but it already had optical and anti-masking systems, a processor, memory and a radio communications module, firmware and the ability to work as part of a security system.This development phase involved several parallel processes.The engineers worked to determine the optimal configuration of the internal components, changed the printed circuit boards and thought through the production and assembly process.The body is developed - the internal design and the exterior.

MotionProtect Curtain components are placed on two circuit boards connected by a loop

MotionProtect Curtain uses a four-layer circuit board with an integrated Jeweler antenna

Ten months into development, we had functional detectors in 3D printed bodies that were as close as possible to the final product in terms of hardware.We were now confident that the design was suitable for large-scale batch production and we could now start developing a new signal analysis algorithm.

MotionProtect Curtain prototype and working device in body printed on a 3D printer

ZOE algorithm

The basis for the development of the new software consisted of the SmartDetect and LISA algorithms used in Ajax's indoor and outdoor motion detectors, as well as the understanding of how the MotionProtect optical system Curtain "sees" people, animals, birds and natural interferences.We collected 30 identical detectors and installed firmware with a draft version of the ZOE algorithm so that the devices could make their own decisions regarding which signal can be considered an alarm to be sent to the hub and which signal should be ignored as interference .And we equipped them with special "black boxes" that retain all the original data in the detector memory when activated.

The prototype detectors were tested in real buildings in Ukraine, Italy, Spain, Greece and Cyprus: urban and suburban land plots, apartments, houses and offices with the most unfavorable conditions that the curtain detectors could encounter.When the sun blinds the lens, the body is filled with rain, trees, shrubs and tall grass appear in the field of view, and animals of different sizes constantly trigger false alarms.Since the summer, the R&D team has been moving into a giant industrial cold store with a temperature of -20 ° C for several days to test the operation of the device under extreme conditions.

MotionProtect curtain in a black housing (indoor use only)

Over the course of a month, we perfected ZOE: we received false alarms, compared the data from the "black boxes" with the detection conditions, made corrections to the code and updated the software of the test devices.Each new version of the algorithm reduced the number of false alarms until we achieved absolute accuracy in human detection and effective interference filtering.

How ZOE works

The motion detection system of the MotionProtect Curtain Curtain Detector offers two modes: with active pet immunity and without.

When pet immunity is enabled, PIR sensors represent independent data sources.Once in the detection zone, a person passes two solar emitters that generate signals from two sensors with the characteristic symmetry and coverage.The ZOE algorithm immediately analyzes the data by comparing the parameters of the signals and making a judgment: intrusion.Animals, looks, leaves fluttering in the wind, air currents trigger signals of different nature and the MotionProtect curtain ignores them as false alarms.In this mode, the curtain detector can work outdoors.

Fourteen months after development, the second street motion detector, MotionProtect Curtain, appeared in the Ajax range.With ultra-precise human detection, effective animal immunity and false alarm protection.Indoor and outdoor use and with anti-masking capabilities.With reliable and safe jeweler technology and excellent autonomy.Can be configured remotely via the app.Ready to secure an apartment, a detached house and commercial or manufacturing facilities.

cutlery

Refer to the device's user manual for more information.