AGD SYSTEMS AGD315-207 AGD 315-207-000 Microwave Vehicle Detector User Manual AGD340

AGD SYSTEMS LTD AGD 315-207-000 Microwave Vehicle Detector AGD340

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© AGD Systems Ltd 2010. All rights reserved., the information contained in this document is the property of AGD Systems Ltd., and is supplied without liability for errors or omissions. AGD315 User ManualPage 1 of 12 AGD315-205 and AGD315-207 RADAR USERS MANUAL 1 INTRODUCTION These instructions detail the use and operation of the AGD315-205 and -207 radars. This radar has been specifically designed for the accurate measurement of the speed and range of passing vehicles when mounted at the side of the road for enforcement purposes. The radar is designed to work in conjunction with an AGD340 radar plus a host, photographic based, enforcement system. The host system may be mobile or fixed location in nature. The radar is supplied in a black plastic enclosure which incorporates all the radar circuitry and processing circuitry to perform the speed and range measurement. The connection to the radar is via a 1 metre cable with multi-pin connector, and mounting is provided by fixings on the housing. The AGD315-205 is a 24.2GHz frequency modulated continuous wave (FMCW) radar whereas the AGD315-207 is a 24.125GHz (24.075GHz-24.175GHz) radar which are capable of measuring range and speed. The radar’s integral planar antenna forms a narrow beam which is sited at a predetermined angle across the road. When vehicles pass through the beam the radar accurately measures the speed and range at a frame rate of 40 readings per second via an advanced digitising and tracking technique to a resolution of approximately 1 mph and 2 metres. Details of each vehicle speed measurement are passed to the host system via a high speed serial communications interface. Changes or modifications to this equipment, not expressly approved by AGD Systems Ltd, may void the user’s authority to operate this equipment Contents 1 INTRODUCTION 2 DOCUMENT REVISION 3 FMCW OVERVIEW 4 SPECIFICATIONS 5 SYSTEM HARDWARE OVERVIEW 6 MESSAGE FORMATS 7 RADAR USAGE 8 CABLE CONNECTIONS 9 TEST & CALIBRATION
, © AGD Systems Ltd 2010. All rights reserved., the information contained in this document is the property of AGD Systems Ltd., and is supplied without liability for errors or omissions. AGD315 User Manual Page 2 of 12 2 DOCUMENT REVISION Issue Amendment Details Date of Issue By 1 Initial Draft 23/12/2009 NK 2 DCR3006 – added section relating to test and calibration procedures. Figures and Tables identified using auto-numbered captions. 14/06/2010 SCH 3 FMCW OVERVIEW 3.1 Basic Operating Principles of FMCW Radar In an FMCW radar such as the AGD315-205/207, the following basic operating principles are applied: The transmit signal is frequency modulated, normally by a linear modulation (a chirp) The modulation of the received signal is compared to the modulation of the transmitted signal to determine time delay and therefore range velocity is determined by range differentiation or Doppler processing Consider a signal transmitted from the radar at time t=0 and with frequency fstart. When this signal strikes a target, the signal will be reflected back and received by the radar at a time t=tdelayed. During the time of flight of the reflected signal. the transmit frequency will have increased to a new frequency fdelayed, where fdelayed is given by the chirp rate and amplitude. Hence at any instance in time after tdelayed, there is a difference in frequency between the transmitted and received frequencies. This frequency difference is proportional to the time of flight for the received signal, and since the radar signal travels at the speed of light (a constant), the time of flight is also proportional to the range of the target which reflected the radar signal. In an FMCW system, the transmit and receive signals are compared using an RF Mixer. The mixer is driven by the transmit and receive signals, and the mixer output is the difference between the two input signals. The output signal is referred to as the intermediate frequency (IF). If the IF is sampled into an analogue to digital converter (ADC) at fixed time intervals during a single excursion of the frequency modulation (one period of the chirp) and the resultant digital signal is viewed in the frequency domain, a number of different frequencies will be seen, where each frequency corresponds to a target at a particular range. If data from a number of successive chirps is gathered and processed, speed and range for individual targets can be determined.
, © AGD Systems Ltd 2010. All rights reserved., the information contained in this document is the property of AGD Systems Ltd., and is supplied without liability for errors or omissions. AGD315 User Manual Page 3 of 12 4 SPECIFICATIONS Radar General Items Specification Notes Housing Black UV stabilised polycarbonate Fine spark finish Radar Weight 0.80 Kg Including 1 metre lead and connector External Dimensions 160mm(W) x 130mm(H) x 60mm(D) Mounting Fixings 4 x M4 threaded inserts M16 cable gland Sealing IP66 Radar Connection 9 pin Bulgin Bucanneer (male) attached to end of 1 metre lead Bulgin PX0728/P See section 9 for more information Radar Labelling Manufacturer’s Label LED Red status indicator LED Blue ‘Bluetooth’ indicator LED Radar Power Connection Parameter Specified Tolerance Notes Supply Voltage 24V dc 9-30V Current 263mA 10% At 12Vdc Radar Data Connection Parameter Specified Notes 4 wire RS 422 See extra notes on data connection and BAUD command.
, © AGD Systems Ltd 2010. All rights reserved., the information contained in this document is the property of AGD Systems Ltd., and is supplied without liability for errors or omissions. AGD315 User Manual Page 4 of 12 Environmental Performance Test Severity Specification Cold (-20 C Operational) IEC 68-2-1 Test Ab Dry Heat +60 C Operational IEC 68-2-2 Test Bb Damp Heat Cyclic 48Hrs 25 C to 40 C 95%RH IEC 68-2-30 Test Db Free Fall Each top rear corner & each top rear face. 1000mm free fall to concrete. IEC 68-2-32 Test Ed Drop and Topple All faces & corners 100mm drop IEC 68-2-31 Test Ec Shock 4000m/S2, 2mS Duration IEC 68-2-27 Test Ea Random Vibration 0.02g2/ Hz (10-50Hz) 0.01g2/ Hz (50-150Hz) 0.002g2/ Hz (150-500Hz) Overall RMS 1.58g 3Hrs on X,Y,Z axes IEC 68-2-34 Test Fd Sinusoidal Vibration 5-7Hz 1.5mm 7-35Hz 10m/S2 IEC 68-2-6 Test Fc Bump 1000 in X,Y,Z axes 100m/S2,16mS IEC 68-2-29 TestEb Immersion Preconditioned to +30 C over ambient before 12Hrs Immersion. IEC 68-2-18 Test R Radar Transceiver Component Specification Notes Antenna Planar patch array Transmitter Quarter wave resonator Receiver Homodyne I Q down converter Radome Black UV stabilised polycarbonate Radar Transmission Parameter Specified Notes Radar Centre Frequency 24.200 GHz UK/EU/AS/NZS 24.125GHz USA Modulation Bandwidth 80MHz Operating Frequency Band 24.150 - 24.250GHz (UK/EU/AS/NZS) 24.075 – 24.175GHz (USAVersion) Modulation bandwidth of ~80MHz plus temperature stability guard bands (+/- 10MHz) Fundamental Frequency Power <20dBm EIRP Fundamental Frequency Field Strength <1000mV/m @3m Frequency Temperature Stability Typically < 1 MHz/ C Uncompensated Polarisation Plane polarised with E-Field vertical Horizontal Beamwidth 7 degrees
, © AGD Systems Ltd 2010. All rights reserved., the information contained in this document is the property of AGD Systems Ltd., and is supplied without liability for errors or omissions. AGD315 User Manual Page 5 of 12 Vertical Beamwidth 28 degrees Spurious < 1 W EIRP (25 to 22000MHz) Emission Code 80M0FXN ITU Designation Antenna Sidelobe Suppression >15dB Radar Detection Parameter Specified Notes FFT size 256 point Tracking window Not Applicable Image Rejection Not Applicable Measurement rate 40 Hz The number of speed \ range measurements made per second Technical Performance Specifications Radio Specifications ETS300.440, AS/NZS4268 FCC 47CFR15.245
, © AGD Systems Ltd 2010. All rights reserved., the information contained in this document is the property of AGD Systems Ltd., and is supplied without liability for errors or omissions. AGD315 User Manual Page 6 of 12 5 SYSTEM HARDWARE OVERVIEW A simplified block diagram of the AGD315-205/207 is shown below: 4k x 18 bitFIFOS12 bit ADCRadar Transceiver ModuleDDS \ DAC Amplifier& FilterSubsystemPIC 18F452 TI C6711 DSP & associatedcomponents (SDRAM,FLASH etc)Power Supplies Figure 1 System Hardware Overview 5.1.1 Serial interface, RS422 A UART interface is provided using RS422 voltage levels, over a 4 wire (full duplex) interface. The default baud rate for this interface is 115200. This may be changed using the BAUD command to speeds of up to 921600. The BAUD command will store the baud rate into non volatile memory of the radar ready for the next time the radar boots. The serial interface default setup during normal operation is shown in Table 1.
, © AGD Systems Ltd 2010. All rights reserved., the information contained in this document is the property of AGD Systems Ltd., and is supplied without liability for errors or omissions. AGD315 User Manual Page 7 of 12 Parameter Value Baud rate 115200 Data bits 8 Parity bits None Stop bits 1 Flow control None Table 1 Default UART Settings The RS422 provides the primary output of the radar in the form of ASCII messages. These messages provide speed and range information. 5.1.2 LED’s No LED’s are visible from the outside of the unit. A number of internal LED’s are provided for test and debug purposes. 5.1.3 Temperature Sensor A digital temperature sensor has been installed on the digitiser board. This allows the processor to monitor environmental conditions. The temperature of the radar may be requested using the TEMP command. 5.1.4 Non Volatile Memory An EEPROM is installed on the board to provide non volatile memory. The primary use of this EEPROM is to store configuration and calibration data. 5.2 Power supply board CB-180 The radar is powered using a DC voltage in the range of 9 to 30 volts. The radar is polarity protected using a diode. The radar can take a very large current doing power up that is of the order of amps. However, this current only lasts for ~1ms and should not affect most applications. 5.2.1 Input Protection A one shot anti-surge (T) fuse with a 630mA rating has been installed to protect against electrical short circuit fault conditions.
, © AGD Systems Ltd 2010. All rights reserved., the information contained in this document is the property of AGD Systems Ltd., and is supplied without liability for errors or omissions. AGD315 User Manual Page 8 of 12 6 MESSAGE FORMATS 6.1 Standard Messages In normal operation, the radar produces a single standard message of the following form <frame number>,<radar mode>,<detection direction>, <cosine correction>:<debug info>#<target information><CR> A sample message sequence from a typical roadside test is shown below: 0001917903,R,A,22: #T0:A,29,11,11.7,70.3 0001917904,R,A,22: #T0:A,29,11,11.7,60.4 0001917905,R,A,22: #T0:A,29,11,11.7,65.5 0001917906,R,A,22: #T0:A,29,12,12.8,61.0 0001917907,R,A,22: #T0:A,29,12,12.8,66.1 0001917908,R,A,22: #T0:A,28,12,12.8,68.4 0001917909,R,A,22: #T0:A,28,13,13.8,65.5 0001917910,R,A,22: #T0:A,28,12,12.8,67.3 0001917911,R,A,22: #T0:A,27,13,13.8,63.0 0001917912,R,A,22: #T0:A,28,13,13.8,71.2 The fields in each message are described in the table below: Field Descriptor Explanation Comments Frame number Increments every frame Reset if detector is rebooted Radar Mode R – ranging mode Factory set by AGD Detection direction Advance, Recede, Bidirectional See section 8 – radar usage Cosine correction Mounting angle to the road Debug into Between : and ! AGD use only Target Information Target number, Direction, Range bin, Doppler Bin, Speed, Power Level Range bin = 2 metres Doppler bin = ~1 mph Speed includes cosine correction and is in either mph or kph Table 2 Message Descriptors Notes: Speed – vehicle speed will be modified by the cosine of the dominant detector mounting angle. Use the *AD<space><angle><cr> command to set the mounting angle of the detector relative to the road surface, and use UNITS<space>MPH<cr> or UNITS<space>KPH<cr> to set the measurement units. The fundamental unit of speed measurement is the Doppler bin, which is approximately equal to 1mph, so the speed resolution of the radar cannot be any better than this, no matter what units are selected.
, © AGD Systems Ltd 2010. All rights reserved., the information contained in this document is the property of AGD Systems Ltd., and is supplied without liability for errors or omissions. AGD315 User Manual Page 9 of 12 7 RADAR USAGE 7.1 Introduction For best detection performance the radar must be setup correctly. Failure to do so can result in inaccurate or false detections. 7.2 System Integration The AGD315-205/207 has been designed to be used in conjunction with the AGD340 and a host system. It is the responsibility of the supplier of the host system to ensure that data fusion \ correlation of the speed and range data from the AGD315-205/207 and speed data from the AGD340 is done in such a manner as to be ‘fit for purpose’. 7.3 Radar Mounting Angle Radars are supplied factory programmed to be used for a specific mounting angle, usually to 22 degrees. This angle is the angle the radar points across the road from the direction of the road, see Error! Reference source not found.. The angle is also reported in all output messages and the command *AD may be used to determine it. This angle is used by the radar to adjust the speed the radar measures to the actual target speed and therefore it is important the radar is setup with the correct angle. If the radar is setup with an angle that is less than the mounting angle then the radar will measure speeds that are larger than the vehicles true speed, while if the angle is greater than the mounting angle the radar will measure speeds that are less than the vehicles true speed. 22o Figure 2 Radar Mounting Angle The radar transmits a radio beam across the road that has a horizontal beam width of ~7 degrees. The vertical beam width of the radar beam is relatively large at 28degrees so although the radar should be made level this is not crucial for correct operation. For a fixed camera installation often the radar is mounted relatively high (~3m) and in this case it is desirable to point the radar more down towards the ground. In this application careful consideration of the radar beam and its shape is required to ensure that all the lanes of the road are covered.
, © AGD Systems Ltd 2010. All rights reserved., the information contained in this document is the property of AGD Systems Ltd., and is supplied without liability for errors or omissions. AGD315 User Manual Page 10 of 12 7.4 Maximum Speed Measurement Normally, the radar can detect targets travelling in both directions simultaneously (if required) at speeds of up to 128mph. The radar can resolve the speed to the nearest Doppler bin, which is approximately equal to 1mph. In some situations, it may be required that the radar measure higher target speeds than 128mph. It is possible to configure the radar to measure targets up to 255mph, but with the caveat that the radar must be set into either advance or recede mode (not bidirectional), and targets travelling in the wrong direction at sufficient speed will generate erroneous speed readings which appear to have come from the required direction. For example, if the radar is set into advance mode, and the command *RV<space>150<cr> is sent to the radar, the following behaviour will be seen: Vehicle Speed (mph) Vehicle Direction Radar Operation 0 – 10 Approach Vehicle not detected, speed is below the low speed cutoff 10 – 150 Approach Vehicle detected, speed and direction measured correctly, message sent 150+ Approach Vehicle not detected, speed is above upper limit set by *RV 0 – 10 Recede Vehicle not detected, speed is below the low speed cutoff 10-105 Recede Vehicle detected, speed and direction measured correctly, no message 105+ Recede Vehicle detected, speed and direction measured incorrectly, message sent Table 3 Maximum Speed Behaviour So, the *RV command is used to set the maximum speed measurable in the required direction. Under most situations, the erroneous speed measured can be filtered out because the range measurement will be incorrect. One situation where the range cannot be used to filter out erroneous targets is for a vehicle driving the wrong way down the road at excessive speed (for example, a vehicle driving the wrong way down a dual carriageway or motorway). However, two radars deployed at the same position, one set to approach and one set to recede, both with the same *RV setting could be used under these circumstances, which would give the capability to measure up to ±255mph (255mmph approach with one radar, 255mph recede with the other). Under most normal situations however, a single radar will the capability for ±128mph should be sufficient.
, © AGD Systems Ltd 2010. All rights reserved., the information contained in this document is the property of AGD Systems Ltd., and is supplied without liability for errors or omissions. AGD315 User Manual Page 11 of 12 8 CABLE CONNECTIONS The AGD315-205/207 connections are shown in the table below: Pin No. Wire Colour Function Power Off Power On - No Detect Power On - Detect 1 Orange \ White 24v ac or 12-24v dc 2 White \ Orange 24v ac or 0v dc 3 Green Earth / Ground 4 Blue \ White Detector RS422 Y 5 Brown \ White Relay Common 6 White \ Brown Relay Contact N/C N/O N/C 7 White \ Blue Detector RS422 Z 8 White \ Green Detector RS422 B 9 Green \ White Detector RS422 A Table 4 Cable Connections 9 TEST & CALIBRATION 9.1 Overview The AGD315-205207 is subjected to rigorous build, calibration and test procedures. These procedures are designed to provide a simple set of pass and fail criteria for production operatives to ensure standardisation in the delivered product, isolate faults so they can be identified and fixed prior to unit shipment, and to weed out infant mortality failures in components. 9.2 Configuration Of User Settings Once a unit has been calibrated, a number of specified settings are adjusted, and further tests are carried out to ensure the unit is operating within acceptable limits (please refer to Figure 3 overleaf). Table 5 summarises the user settings which are adjusted, showing the tests carried out, and the pass \ fail criteria applied to each test. Test Description Pass \ Fail Limits Comments 11 Check for correct operation of RS422 Receive OK Transmit OK At 115200 baud 12 Check serial number via RS422 port Same as serial number set previously Serial number cannot be adjusted via RS422 for security 13 Message OK Frame rate 40FPS Cosine set to 22º Message should start automatically on power up Table 5 User Settings
, © AGD Systems Ltd 2010. All rights reserved., the information contained in this document is the property of AGD Systems Ltd., and is supplied without liability for errors or omissions. AGD315 User Manual Page 12 of 12 Figure 3 shows the process by which the user settings are configured: Set ranging modeSet 40 FPSSet 22 degrees(via LW port)Enter serialnumberxxxxx-yyyyy(via LW port)Reboot unitRS422 OK ?YESNOSTARTUnitcalibrated ? Calibrate unitYESNOValues stored inparameterEEPROMConnect to unit viaLivewire portValues stored insecureEEPROMEnableRS422 portSet baud rate(115200)Checkserial number(via RS422 port)FAIL (TEST 11)xxxxx-yyyyy fromsecure EEPROMSerialnumber OK?YESNO FAIL (TEST 12)Enable rangingdiagnosticmessageReboot unitMessage OK ?YESNO FAIL (TEST 13)ENDTEST11TEST12TEST13 Figure 3 Configuration Of User Settings

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