TOP-ARM TECHNOLOGY WHITE PAPER
MRD (Motion Recognizable Detection) Driver
- An application precedent for using phased array radar technology in burglar alarm industry.
For a long time, due to various false alarms, Microwave Intrusion Sensor had been forgotten by us. And Passive Infrared (PIR) Sensor and Dual-tech Sensor become the mainstream in burglar alarm industry. But unfortunately, the change of ambient temperature has strong influence on sensitivity, range and accuracy of PIR Sensor. Especially, when the ambient temperature approaches that of human body (approx. 33℃), it will cause almost fatal damage to the detection sensitivity of PIR Sensor, to shorten the detection range even make sensor failed.
Without doubt, Dual-tech Sensor also faces with the same troubles with temperature. That is because Dual-tech Sensor is the combination of PIR and microwave technologies. Due to various false alarms easily caused by microwave element, Dual-tech Sensor relies mainly on PIR element while making microwave element subsidiary. That is to say, when PIR element detects intrusion signal, and microwave element also detects the same intrusion signal simultaneously, then Dual-tech Sensor is triggered. On the other hand, when microwave element detects intrusion signal first, Sensor still needs PIR element to verify. So, it is only when PIR element detects intrusion signal that Dual-tech Sensor is triggered.
Of course, better measures for temperature compensation can be used in Dual-tech Sensor, such as thermo-sensitive resistance and semiconductor circuitry, but they can only improve appreciably the impact of temperature on detector, anyway cannot completely settle the troubles with temperature-the limitation of PIR detection.
To make things worse, because PIR Sensor only detects the temperature difference between intruder and ambient environment, if intruders hide themselves to avoid or reduce infrared radiation, they can easily pass through the protected area and cannot be detected by PIR Sensor. To take a simple test, when we cover ourselves with raincoat or umbrella, then we can successfully pass through the areas protected by such kind of sensors, with no alarm response. That is very dangerous to end users.
In this case, are there any better new ways to completely settle these troubles? Yes, using MRD Sensor, a Dual Microwave Sensor which is based on Digital Phased Array Radar, not conventional Doppler Microwave.
MRD Sensor not only completely performs the advantages of Microwave Sensor such as high sensitivity, hidden installation, anti-mask, and trouble free from temperature, but also drastically settles false alarms caused easily. By using digital phased array radar, MRD Sensor can recognize and analyze the shape and relative displacement of intrusion object, to accurately distinguish the difference from intruder, pet, and ambient swinging objects such as tree, clothe, window curtain, and drafts from outlet of cooling system etc. In this way, it not only can consumedly improve the detecting sensitivity, but also be immune to false alarms. This revolutionary innovation makes a great mean to security and reliability of sensor, even improves accuracy of alarm system and reduces the operating cost for alarm control center.
What is more, MRD Dual Microwave Sensor brings us more benefits in application. With its penetration through masks and blocks, it can be embedded in wall or hidden behind wall, picture frame etc. to furthest protect the sensor against intruder, no impact on house decoration but still achieving optimum performance.
You may know that, the Fresnel lens of PIR Sensor and Dual-tech Sensor is out of housing. It is easily masked by dust, and sprayed intentionally by intruder with some materials such as mousse which can make the detector failed suddenly. These malfunctions cannot be found immediately and may cause great property damage to end user. Contrarily, there are no such troubles with MRD Sensor because of its anti-mask feature (up to 15m, full range). It can save more time, efforts and maintenance cost for end user, and no more troublesome service calls to distributor.
In addition, such Sensor is suitable for environmental extremes, even works well at harsh temperature ranged from -55℃ to +65℃. It is ideal for use in oil field, desert, iceberg, high temperature production area etc.
Overall, MRD Sensor is really best choice for current users. To understand well the advantages of MRD? Sensor compared with conventional Sensor, let’s refer to the following table:
MRD Sensor Conventional Sensor
Anti-False Alarm Index * : ≥95% <4%
Recognize Human & Object: Yes No
Working Temperature Range: -55℃ to +65℃ -30℃ to +55℃
Blind Temperature Range: No Yes (-30℃ to -10℃, +33℃ to +37℃)
Anti-mask: Yes, Full Range No or short Range
Alarm Response: Quickly Slowly
Hidden Installation: Yes No
Power Consumption: 8 to 10mA ≥25mA
Routine Maintenance: No Need Frequently
Notice:
Anti-False Alarm Index * derives from Top-arm laboratory which is specially for R&D of MRD series products. 95% is a composite index of anti-false alarm. It integrates various environmental factors which may cause false alarm, including direct or oblique incidence of sunlight, swinging of big or small trees, rainfall of 1mm to 100mm/h, wind speed of 0 to 40km/h etc. It indicates the capability of anti-false alarm of a sensor. (Under the same conditions, the anti-false alarm index of conventional sensor is less than 4%).
MRD-Human target moving detection technology based on digital phased array radar, It can collect and recognize the shape and relative displacement of moving object, to quickly distinguish human body and common object according to the law of motion of shape. MRD creates an application precedent for using phased array radar technology in burglar alarm industry.
Continual Working Temperature Range from -55℃ to +65℃
Due to limitation of PIR detection principle, PIR sensor features lower limit of temperature at -30℃ and upper limit at +55℃. To be worse, it exists temperature dead-range i.e. -30℃ to -10℃ and +33℃ to +39℃ within its working temperature range. But MRD sensor features continual working temperature from -55℃ to +65℃, even without dead range.
Dynamic Dual-slope Temperature Compensation
DT928 adopts advanced dynamic and continuous digital dual-slope temperature compensation circuitry which can accurately sense temperature change, then precisely adjust the AGC circuitry to perform gain compensation. This helps to consistently keep the sensor in optimum performance, even when ambient temperature approaches that of human body.
1. Adopts precise temperature sensor which features 1% of deviation rate
2. Adopts dual slope temperature compensation. The Microprocessor can dynamically and continuously adjust the AGC of detector according the ambient temperature. When the ambient temperature approaches that of human body, the gain compensation of circuitry will reach its maximum. So, dual slope temperature compensation can ensure the constant optimum performance for the sensor
3. Usually, ambient temperature is quite different with that of human body. When intruder moves within protected area, the amplitude variation of received signal changes greatly and exceeds the preset alarm threshold, then the sensor triggers an alarm. But if no temperature compensation and, when ambient temperature approaches that of human body, the amplitude variation changes very little and cannot reach the preset alarm threshold, so it may cause alarm failure.
4. As to conventional lineal temperature compensation, when temperature goes up, compensation increases, if the ambient temperature approaches that of human body, it may cause excessive compensation and generate false alarm.
If PIR sensor doesn’t feature temperature compensation circuitry, the gain of circuitry will differ with temperature. When the ambient temperature goes up, the gain of circuitry will come down, the detection range will shorten. When the ambient temperature approaches that of human body, the sensor will fail to function normally. On the other hand, when the ambient temperature comes down, the gain of circuitry will go up, the detector will easily cause false alarms.
Sophisticated Alloy Paraboloidal Reflecting Curtain Mirror Optic
Usually, there are three focusing methods for PIR sensor, i.e. reflecting, transmitting and refracting. Reflecting method features the highest sensitivity and longest range, and the transmitting method features lowest sensitivity and shortest range. It is transmitting method that the Fresnel lens utilizes. But because Fresnel lens is of small size, easy to seal and lower cost, it is widely used in some economic PIR detectors. As to reflecting optics, such as sophisticated alloy paraboloidal reflecting mirror optic, it can more efficiently and uniformly concentrate infrared energy to PIR element than Fresnel lens. So the signal amplifier circuitry can realize lower gain of circuitry and higher Signal to Noise Radio, and the sensor can obtain uniform sensitivity throughout protected area. In this way, the sensor can consumedly prevent false alarm caused by interfering signals.
Resulting of several yeas R&D, Top-arm has developed the most advanced and sophisticated mirror optics for its PIR motion sensor. This, combining with unique intelligent signal processing, makes Top-arm PIR sensors both more stable in harsh environment and more sensitive in reliable detection.
Typical Mirror Beam as above-Use multiple disparate beams that create fingers of detection that leave some areas.
Top-arm Curtain Mirror Optics as shown above
Top-arm PIR sensors use sophisticated paraboloidal alloy curtain mirror optics. Compared with conventional Fresnel lens, it features:
1. More efficient focusing rate for infrared on PIR element
2. High Density Optics (HDO), providing more and wider step-gliding curtains (therefore untraceable gaps).
3. niform sensitivity throughout the protected area, even
4. mooth and continuous automatic target focus
5. More excellent catch capability
6. Resistant to aging and corrosion, suitable for environmental extremes
Artificial Intelligent Verification (AIV)
-To make more accurate alarm decision
By using the principle of fuzzy mathematics logic, the built-in microprocessor can collect and analyze the information of reflected spectrum such as duration, amplitude, holding time and polarity etc., then establish a recognition database to be stored in mass storage unit. By comparing the successive signal patterns, caused by human body and other objects, with the signal patterns in database, microprocessor can quickly verify and make an accurate alarm decision-If the signal matched, it must be an intruder and an alarm is generated; if there is no match, the signal is ignored.
Dynamic Threshold Control Circuitry
-Efficient Resistance to High Frequency Interference
When the sensor is encountered high frequency interference and, with the strength of interfering signal increasing, if the alarm threshold keeps unchanged, the Signal to Noise Radio will come down, then the sensor will easily cause false alarms. By using dynamic threshold control, the microprocessor will dynamically and continuously adjust the alarm threshold, to keep the Signal to Noise Radio unchanged, to assure optimum performance and reduce false alarms caused by high frequency interference.
Patented Vector Verification
-Selectable Trigger Direction
When a conventional optic sees a thermal source within the protected area, it will generate a one-dimensional signal (value) then the presence of the thermal source can be detected. However, due to the unique construction, the patented mirror optics can generate a multi-dimensional signal (vector), allowing the detector to recognize not only the presence but also the moving direction of the thermal source.
Thanks to this optic, the EL-380 features selectable trigger direction which allows you to determine, by using the jumper, the trigger direction of intruder across the protected area. It can trigger an alarm when an intruder walks from left to right and differentiate intruder movement from right to left, and vice versa.
Selectable Trigger Delay Period
The EL-380 features 4 selectable trigger delay periods: 0sec, 40sec, 180sec and 360sec. Within the selected trigger delay period, though the target moves along the configured trigger direction, it will not trigger an alarm. In addition, with the count-down timer and in the last 30 seconds, the green LED indicator will light up to caution. If over the selected trigger delay period, the sensor will trigger an alarm.
Optional Curtain Mode and Wide-angle Detection Mode
EL380 features Curtain Detection Mode and Wide-angle Detection Mode for option. If the curtain optic is uninstalled and the trigger delay period is configured as 0sec, it will become a wide-angle sensor, with detection range up to 10*10m.
Auto Photosensitivity Adjustment
-Selectable Day/Night Working Mode
As lighting conditions change greatly from day to night, if the outdoor sensor works all the times, its working attribute will also change greatly. By using the characteristic of photosensitive resistance which resistance value varies with lighting conditions, the sensor circuitry will automatically adjust sensitivity according to lighting condition and working time period, to confirm day or night working mode, so it can efficiently prevent false alarms caused by bright light in day.
IRC Dual-tech Auto Shift
-Ensure normal working even with one technology, PIR or Microwave
The supervision circuitry controlled by microprocessor supervises in real time the working status of PIR and microwave element. If one of them fails to function, the sensor can automatically shift to another to ensure normal working.
Environmental Discrimination Circuitry-EDC
-Efficiently Prevent Environmental Disturbance and Intentional Interference
Environmental Discrimination Circuitry is designed to analyze and discriminate environment interference. When the received signal attenuates due to environment interference, or is interfered by other infrared source, it will trigger EDC relay to generate an alarm signal. So Environmental Discrimination Circuitry can prevent intentional damage because it can recognize:
1. Interference from other brand’s transmitter, even
2. Interference from the same model’s transmitter
3. Interference from IR remote control
4. Other environmental disturbances such as fog, rain, snow etc.
When the receiver is artificially interfered and masked by intruder, EDC will immediately generate an alarm to caution the user. This function can consumedly improve security of alarm system.
ASK High Frequency Modulation
-Efficiently Eliminate High Frequency Disturbance
Top-arm photoelectric beam product adopts professional ASK (Amplitude Shift Keying) high frequency modulation technology. Compared with traditional frequency modulation (with 1KHz transmitting frequency), it features:
1. Efficiently avoiding environmental disturbances; 10 times of anti-interference capability than traditional modulation
2. Stable signal transmitting, allowing the photoelectric beam to feature higher sensitivity and 6 time power surplus, to ensure the beam sensor working normally on harsh environmental extremes such as big snow, rain and fog etc.
3. As to traditional frequency modulation, due to 1KHz transmitting frequency, its signal is easily interfered by environmental disturbances. So on harsh environmental conditions above, the beam sensor will loss signal or cause missed alarm.
Anti-Crawl Function
-Efficiently eliminate intentional intrusion
The height from the ground to the upper beam is often enough for an intruder to crawl through. If no anti-crawl function, only when the upper plus lower beams are interrupted simultaneously, the beam sensor is triggered. So it is easy for an intruder to crawl through the protected area without alarm response, only interrupted the lower beams. With anti-crawl function, when the lower beams are intercepted for 4 seconds, then the beam sensor is triggered. In this way, the anti-crawl function efficiently improves the security for the user, to eliminate intrusion damage.
Nanometer Material Coating
-Ensure optimum performance in outdoor application
Nanometer material coating prevents mould and corrosion, and makes product surface no water blobs and dust left, suitable for long-time outdoor application, even at harsh environment extremes such as rain, humidity, frost and icing etc.
Multiple Alignment Methods
-Easily align while installation
Provide alignment methods such as multi-lever LED indicator, buzzer, traditional telescope and voltage test.
Power Filter
-filter out the disturbed wave clutter of A.C. frequency
The electronic filter can efficiently filter out the wave clutter, mainly 50Hz/60Hz A.C. frequency wave and its harmonic wave, which may disturb the circuitry and cause false alarms.
* The technical information above is only for reference, we reserve all rights including explanation.
