80-m Range Object Detection With IWR1642 …

1 PC GUIIWR1642 EVMUART port-1 UART port-2RX antennasTX antennasConfiguration FileCopyright 2017, Texas Instruments Incorporated1 TIDUD93 June2017 SubmitDocumentationFeedbackCopyright 2017,TexasInstrumentsIncorporated80-mRan geObjectDetectionWithIWR1642mmWaveSensor ReferenceDesignTI Designs:TIDEP-009480-mRangeObjectDetecti onWithIWR1642mmWaveSensorReferenceDesign DescriptionThe TIDEP-0094providesa foundationto evaluateobjectdetectionusingthe IWR1642evaluationmodule(EVM).This designwill allowthe estimationof theposition(in the azimuthalplane)and the velocityofobjectsin its field of viewup to 84 E2E ExpertsFeatures DetectObjectsup to 84 m WithRangeResolutionof 37 cm AntennaFieldof View 60 WithAngularResolutionof Approximately15 SourceCodefor FastFourierTransform(FFT)Processingand DetectionProvidedby mmWaveSoftwareDevelopmentKit (SDK)

2 IWR1642 EVMD emonstratesDesign RadarFrontEnd and DetectionConfigurationFullyExplainedAppl ications ServiceRobots LogisticsRobots IndustrialRobots IndustrialTransport Forklifts DroneSystemsAn IMPORTANTNOTICEat the end of this TI referencedesignaddressesauthorizeduse, intellectualpropertymattersand otherimportantdisclaimersand June2017 SubmitDocumentationFeedbackCopyright 2017,TexasInstrumentsIncorporated80-mRan geObjectDetectionWithIWR1642mmWaveSensor ReferenceDesign1 SystemDescriptionThe goal of industrialsystemsis to dynamicsurroundingsand the objectsin quicklybeingdeployedas costsarereducedand functionalityis increasedto automatemundaneand ,construction,and heavyvehiclesare increasingin intelligenceto assistin operatorproductivityandenhancethe rapidlyaddingintelligenceto detectobstacles,balanceloads,and disruptingentireindustriesfrompackagedel iveryto of thesesystemsrequirea varietyof sensorsto detectobstaclesin theenvironmentas well as trackobjectvelocitiesand accuratemeasurementof distancesand relativevelocitiesof mmWavesensorsovervisionand LIDAR-basedsensorsare theirrelativelyimmunityto environmentalconditions,suchas rain,dust,smoke,fog, or ,mmWavesensorscan workin completedarknessor in the glareof ,apertures,or sensorsurfaces,the sensorsare 's mmWavesensorsare also small,lightweight.

3 And producedesignsthat are threetimessmallerand half the weightof DesignThe TIDEP-0094is an introductoryapplicationconfiguredto detectobjectsup to a distanceof 84 m aswell as estimatetheirvelocitiesand TI Designcan be usedas a startingpointto designa standalonesensorfor a varietyof rangeof morethan84 m can be achievedwith the designof differentchirpparameters,use of an externallens,or throughdesignof an antennawith highergain thanthe one includedin SystemSpecificationsTable1. Key representsthe maximumdistancethat the radarcan detectan objectrepresentingan RCSof approximately10 m . the abilityof a radarsystemto distinguishbetweentwo or moretargetson the samebearingbut at is the nativemaximumvelocityobtainedusinga two-dimensionalFFT on the specificationwill beimprovedovertime by showinghow higher-levelalgorithmscanextendthe maximummeasurablevelocitybeyondthis parameterrepresentsthe capabilityof the radarsensortodistinguishbetweentwo or moreobjectsat the samerangebutmovingwith GUIIWR1642 EVMUART port-1 UART port-2RX antennasTX antennasConfiguration FileCopyright 2017, Texas Instruments June2017 SubmitDocumentationFeedbackCopyright 2017, IWR1642is an integratedsingle-chip,frequencymodulated continuouswave(FMCW)

4 Sensorcapableof operationin the 76 to 81 deviceis built with TI s low-power,45-nmRFCMOS processorand enablesunprecedentedlevelsof analogand digitalintegrationin an devicehas four receiversand two transmitterswith a closedloop PLL for preciseand sensorincludesa built-inradioprocessor(BIST)for RF calibrationand complexbasebandarchitecture,the sensordevicesupportsan IF bandwidthof 5 MHzwith presenceof ARM Cortex R4F and TexasInstrumentsC674xDSP(fixedand floatingpoint)alongwith MB of VLVDS data and ClKJTAG and traceQSPIF lashEN control from the MCUPGOOD signal to MCU for power sequencing Optional for MCU /DXQFK3DG 60-pin HDXDS110 CANSOPPC Interface through USBBP ConnectorSPI, UART, I2C, Rst, Nerrs, SOPs, Loggers, CAN, and GPIOsControl signals for external MCU interface5-V input from jack and MCUC urrent measurementUART and JTAGP ower and 2 GPIOLED indicators40 MhzXTAL4RX and 2 TX PCBsCopyright 2017, Texas Instruments June2017 SubmitDocumentationFeedbackCopyright 2017, IWR1642has the followingfeatures:1.

5 IWR1642mmWavesensordevice2. Powermanagementcircuitto provideall the requiredsupplyrails froma single5-V input3. Two onboardTX antennasand four RX antennas4. OnboardXDS110that providesa JTAG interface,UART1for loadingthe mmWavesensorconfigurationon the IWR1642device,and UART2to sendthe objectdatabackto the PCFigure2. IWR1642 For moredetailson the hardware,see theIWR1642 EvaluationModule( IWR1642 BOOST)Single-ChipmmWaveSensingSolution[1 ]. The schematicsand designdatabasecan be foundin the followingdocuments: IWR1642 BOOSTD esignDatabase[5] andIWR1642 BOOSTS chematic,Assembly,and BOM[6].xxxxxxxxxxxxRx1Rx2Rx3Rx4Rx1Rx2Rx3 Rx4Tx1Tx2xxxxReal AntennasVirtual AntennasTx2Tx1 FrequencyTimeCopyright 2017, Texas Instruments June2017 SubmitDocumentationFeedbackCopyright 2017, TIDEP-0094usesfour receiversand the two transmittersin the time divisionmultiplexedMIMO configuration(thatis, alternatechirpsin a frametransmiton TX1 and TX2 respectively.)

6 The MIMO configurationsynthesizesan arrayof eightvirtualRX antennas,as shownin Figure3. This techniqueimprovesthe angleresolutionby a factorof two (comparedto a singleTX configuration).Figure3. June2017 SubmitDocumentationFeedbackCopyright 2017, SystemPerformanceTo achievethe specificuse casewith a visibilityrangeof approximately80 m and memoryavailabilityofIWR1642,the chirpconfigurationin Table2 is ChirpConfigurationPARAMETERSPECIFICATION SIdle time ( s)3 ADCstarttime ( s)3 Rampend time ( s)56 Numberof ADCsamples256 Frequencyslope(MHz/ s)8 ADCsamplingfrequency(ksps)5000 MIMO(1 yes)1 Numberof chirpsper profile64 Effectivechirptime (usec) (MHz) (ms) (KB)512(1)Thoughnot implementedin the currentdesign,notethat thereare severalapproachesthat can improvethe maximumdetectablevelocityseveralmultiple sbeyondthis Table2 configurationis selectedto achievethe systemperformanceshownin Table3.

7 The primarygoal was to achievea maximumdistanceof about85 m. Notethat the productof the frequencyslopeandthe maximumdistanceis limitedby the availableIF bandwidth(5 MHzfor the IWR1642 ).Thus,amaximumdistanceof 85 m locksdownthe frequencyslopeof the chirpto about8 MHz/ s. See theProgrammingChirpParametersin TI RadarDevices[2] applicationreportfor choiceofthe chirpperiodicityis a trade-offbetweenrangeresolutionand designusesarange-resolutionof m, whichleavesa nativemaximumvelocityof about30 kmph(1). For detailson the connectionbetweenthe systemperformanceand the chirpparameters,see theProgrammingChirpParametersin TI RadarDevices[2] ,the maximumunambiguousvelocitythat can be detectedis 90 largermaximumdistancetranslatesto a lowerrangeresolution(dueto limitationson boththe L3memoryand the IF bandwidth).

8 A usefultechniqueto workaroundthis trade-offis to havemultipleconfigurationswith eachtailoredfor a example,it is typicalto havethemmWavesensoralternatebetweentwo modes:a low resolutionmodetargetinga largermaximumdistance(suchas 85 m with )and a high resolutionmodetargetinga shorterdistance(suchas 20 m with 4-cmresolution).This multi-modecapabilityis not implementedin the currentTIdesignbut is targetedfor a SystemPerformanceParametersPARAMETERSPEC IFICATIONSR angeresolution(m) (m) (kmph) FirmwaremmWaveFront EndRadar DataCapture1st dim FFT2nd dim FFTO bject Detection (CFAR)Direction of ArrivalEstimationSend out detected Object data to UART portDSSC opyright 2017, Texas Instruments June2017 SubmitDocumentationFeedbackCopyright 2017, examplein the distributionthat representsthe TI Designallowsthe userto pushthe 'sGuide[7]

9 Describesthe semanticsof the followingcommandsin commandsrepresentthe configurationchoicesdescribedin 3 0adcCfg2 1adcbufCfg0 0 1 1profileCfg0 77 3 3 56 0 0 8 1 256 50000 0 30chirpCfg0 0 0 0 0 0 0 1chirpCfg1 1 0 0 0 0 0 2frameCfg0 1 64 0 100 1 0lowPower0 0guiMonitor1 1 1 0 0 1cfarCfg0 0 8 4 4 0 5000cfarCfg1 0 8 4 4 0 5000peakGrouping1 0 1 1 224multiObjBeamForming0 -5 8 256sensorStartThe profileconfigurationdefinesthe profileof a singlechirp(as per Table1). Subsequently,two chirpconfigurationsare definedeachone inheritingthe sameprofilebut associatedwith Tx1 and frameconfigurationmessageconstructsa framewith transmissionsalternatingbetweenTx1 and blockdiagramin Figure4 showsthe processingdatapart to the ProcessingChainAcquisition PeriodFrame Period Acquisition and 1st D FFT2nd D FFTCFAR detectionPost processingAzimuth and (X,Y)estimationAcquisition and 1st D FFTDSS: Inter frame processing time Send out dataMSS.

10 Copyright 2017, Texas Instruments June2017 SubmitDocumentationFeedbackCopyright 2017, showsthe timingof the chirpsand subsequentprocessingin the Top LevelDataPathTimingAs seenin Figure5, the datapathprocessingis describedbelow. The RF frontend is configuredby the BIST subsystem(BSS).The raw dataobtainedfromthe variousfrontend channelsis takenby the C674xDSPsubsystem(DSS)for processing. Processingduringthe chirpsas seenin Figure5 consistsof: 1D ( Range )FFT processingperformedby the C674xthat takesinputfrommultiplereceiveantennaefro mthe ADCbufferfor everychirp(correspondingto the chirpingpatternon the transmitantennae) Transferringtransposedoutputinto the L3 RAMby EDMA Processingduringthe idle or cool downperiodof the RF circuitryfollowingthe chirpsuntil the nextchirpingperiod,shownasInterframeproc essingtimein Figure5.