Ultrasonic distance measurement obstacle avoidance systemTechnical field
The utility model belongs to ultrasonic distance measurement field, and in particular to a kind of ultrasonic distance measurement obstacle avoidance system.
Background technique
With the development of sensor technology, in distance measuring sensor field, more commonly used technical solution is divided by following three kindsNot are as follows: infrared distance measurement, laser ranging and ultrasonic distance measurement.Infrared distance sensor has low cost, circuit structure simply excellentGesture, but its detection range is compared with close, precision is relatively low；Laser range sensor is detection range and precision in above-mentioned three kinds of sensorsHighest but its use cost is excessively high；The effect of ultrasonic distance-measuring sensor between infrared between two kinds of ranging schemes of laser,It is and higher to the adaptability of environment with the moderate and higher detection accuracy of detection range, particularly with transparent substance (such as glassGlass etc.) it can be carried out effective detection, and detecting transparent substance is not available for optical sensor.Ultrasonic wave is to be relatively more suitable for againA kind of technical solution of miscellaneous application scenarios.
The structural block diagram of existing ultrasonic distance measurement scheme is as shown in Figure 1.The echo processing circuit of existing scheme is using firstAmplify the mode being filtered again, due to measuring the difference of distance, the fluctuating change of echo-signal is caused, but also signal existsBiggish error.As shown in Figure 2；Thus the problem of bringing is that other noise letters are also exaggerated while amplifying echo-signalNumber, so that the difficulty of filtering processing circuit is increased, so that subsequent conditioning circuit is more complicated, so that the speed of response reduces.Therefore bandThe detection blind area lower disadvantage of (common minimum blind area is 20cm~30cm) and sensitivity greatly is carried out；Existing ultrasonic wave simultaneouslyRanging is used as single module to occur more, only retains serial ports and uses as debugging, can not be in the field of longer wired communications distanceScape uses, and is unfavorable for integrating with other systems.
Utility model content
To overcome the above the deficiencies in the prior art, the utility model discloses a kind of ultrasonic distance measurement obstacle avoidance systems.
In order to solve the above-mentioned technical problem, the utility model uses following technical scheme: providing a kind of ultrasonic distance measurement and keeps awayBarrier system, including control processing unit, serial port circuit and power management module, further include multichannel ultrasonic transmission circuit, CANTransmission circuit, the control processing unit be connected separately with ultrasonic transceiver circuit, serial port circuit, power management module andCAN transmission circuit, the ultrasonic transceiver circuit is for detecting barrier and measure distance；The power management module is for surpassingSound wave transmission circuit, CAN transmission circuit and the power supply for controlling processing unit, the control processing unit is for each module of systemOperating control.
As the further improvement of the system, the ultrasonic transceiver circuit by least three independent ultrasonic waves transmittings andCircuit composition is received, each independent circuits are set to the different direction of system.
Inventor proposes, since most of autonomous mobile apparatus volume is larger and the limitation of ultrasonic probe investigative range,Existing ultrasonic distance measurement scheme cannot be detected effectively since blind area is larger and carry out multi-angle avoidance, and the utility model is adoptedThe detection of obstacles to three front of system, left side and right side directions is realized with 6 equally distributed independent probes.
Further, each independent circuits include transceiver ultrasonic probe, transmitting-receiving in the ultrasonic transceiver circuitDriving circuit and echo signal processing circuit；Wherein, processing unit, transmitting-receiving driving circuit, transceiver ultrasonic probe are controlledAnd echo signal processing circuit closed loop connection.
The advantage of the utility model scheme compared with the existing technology be ultrasonic transceiver circuit be effectively isolated drive part,Extra noise is caused so that each section will not generate signal interference in echo signal processing circuit part and CAN transceiver part；Circuit uses energy bleeder resistance, for discharging the dump energy after ultrasonic signal transmitting in coil, using clamp diode,So that the amplitude of echo-signal is limited between positive and negative 0.7V, follow-up signal processing circuit is caused to damage to prevent amplitude excessively highIt is bad；Using 10:1 isolation boosting transformer, driving signal increases to the drive signal amplitude on right side by transformer original10 times, to effectively increase the emissive porwer of ultrasonic signal；Effectively optimization circuit, sufficiently improves efficiency, so that circuit is effectiveImprove detectivity and minimum detection blind area.
Further, reception of the transmitting-receiving driving circuit for ultrasonic signal transmitting and echo-signal, wherein ultrasoundWave transmitting has the pulse signal detection barrier of setting amplitude and frequency.
Inventor points out that energy size when emitting due to pulse number to ultrasonic wave is directly proportional, and pulse number is more, becomesThe energy put aside in transformer coil is more, and the distance that ultrasonic wave is propagated in air is also farther, but can cause remained shock of popping one's head inTime increases, and increases the detection blind area of ultrasonic ranging system indirectly.Transmitting pulse number is controlled according to practical application scene,Detection range is utmostly improved with this and reduces detection blind area.
As a kind of more preferable scheme, echo signal processing circuit includes primary amplifying circuit, filter circuit, secondary amplificationCircuit, detection shaping circuit and level shifting circuit, wherein echo-signal is first by filter circuit after primary amplifying circuit is amplifiedIt is filtered, carries out secondary amplification through secondary amplification circuit again thereafter, most obtain square-wave signal through detection shaping circuit afterwards, pass throughLevel shifting circuit is converted into switching signal.
As a further improvement of the foregoing solution, echo signal processing circuit signal input is connected to first resistor oneEnd, the first resistor other end are connected with first capacitor one end, the inverting input terminal of the other end of first capacitor and the first amplifierIt is connected；The non-inverting input terminal of first amplifier is connected to one end of second resistance, and the other end of second resistance is connected to third electricityOne end of resistance, the other end of 3rd resistor are connected with the output end of the first amplifier；The non-inverting input terminal of first amplifier and secondOne end of capacitor connects, the other end ground connection of the second capacitor；The output end of first amplifier is connected with the 4th resistance one end, and the 4thThe other end of resistance is connected to one end of third capacitor, and the other end of third capacitor is connected to the inverting input terminal of the second amplifier；The non-inverting input terminal of second amplifier is connected with one end of the 5th resistance, and the other end of the 5th resistance is connected to the 6th resistance andThe other end after one end after four capacitors are in parallel, the 6th resistance and the parallel connection of the 4th capacitor is connected with the output end of the second amplifier；The non-inverting input terminal of second amplifier is connected with one end of the second capacitor, the other end ground connection of the second capacitor；Second amplifier it is defeatedOutlet is connected with one end of the 7th resistance, and the other end of the 7th resistance is connected with one end of the 5th capacitor, the 5th capacitorThe other end is connected with the inverting input terminal of third amplifier；The inverting input terminal of third amplifier is connected with one end of the 8th resistanceIt connects, the other end of the 8th resistance is connected to the output end of third amplifier；The non-inverting input terminal one side and the 15th of third amplifierOne end of resistance is connected, on the other hand another termination power of the 15th resistance is connected with one end of the 16th resistance, theThe other end of 16 resistance is grounded；The output end of third amplifier is connected with one end of the 6th capacitor, the other end of the 6th capacitorIt is connected to one end of detector diode, the other end of detector diode is connected to the non-inverting input terminal of four high guaily unit；Four high guaily unitNon-inverting input terminal and the 9th resistance and the 7th capacitor it is in parallel after one end be connected, the 9th resistance and the 7th capacitor it is in parallel afterThe other end is connected to the inverting input terminal of four high guaily unit；On the one hand the inverting input terminal of four high guaily unit connects power supply through the tenth resistance,On the other hand it is grounded through eleventh resistor；The output end of four high guaily unit is connected with one end of zener diode, zener diodeThe other end be connected to the base stage of triode；One end after the base stage of triode is in parallel with twelfth resistor and the 8th capacitor is connectedIt connects, the other end ground connection after twelfth resistor and the parallel connection of the 8th capacitor；The emitter of triode is grounded；The collector of triode withOne end of thirteenth resistor is connected, another termination power of thirteenth resistor；Triode is connected with one end of the 14th resistanceIt connects, the other end of the 14th resistance is connected to signal output end.
Further, the low-frequency d in echo-signal that the first capacitor receives transceiver ultrasonic probeSignal filtering, so that preamplifying circuit amplifies the AC signal in echo-signal.
Further, after the detection shaping circuit is by being made of low-pass filter processing the 9th resistance and the 7th capacitorRound and smooth envelope signal is formed, then shaped processing is square-wave signal.
Inventor points out, thus the echo processing circuit of existing scheme is brought by the way of first amplifying and being filtered againThe problem of be also be exaggerated other noise signals while amplifying echo-signal, thus increase filtering processing circuit difficultyDegree, so that subsequent conditioning circuit is more complicated, the speed of response reduces.The preamplifying circuit filter capacitor of application scheme will receive and dispatch oneThe low-frequency d signal in echo-signal that body probe receives filters, so that preamplifying circuit is only to the friendship in echo-signalSignal amplification is flowed, is effectively filtered by unlimited gain multiple feedback bandpass filter；Secondary amplification circuit is to filteredSignal carries out secondary amplification to meet the requirement of subsequent processing；The overall gain of amplifying circuit reaches 30dB after two-stage treatment；40kHz high-frequency signal forms round and smooth envelope signal after detecting circuit；Since envelope signal is not easy to processor processing, needEnvelope signal after detection is subjected to shaping；Since the intensity that ultrasonic probe receives echo-signal is arrived barrier by itselfBetween distance and such environmental effects so that signal amplitude after handling shaping has uncertainty, for the ease of processingDevice is handled, and the signal amplitude after needing to carry out detection shaping is converted into the switch that amplitude is 3.3V by level shifting circuitSignal, after above-mentioned processing, the obtained signal of this system effectively reflects detecting distance, so that detection sensitivity is effectively promoted.
Above-mentioned echo signal processing circuit is only the single channel electricity in the ultrasonic distance measurement obstacle avoidance system of the utility modelRoad, whole system are made of 6 identical channels, it is achievable to multiple directions while detect.
Further, CAN transmission circuit one end is connected with control processing unit, and the other end is connected with master controller,For realizing between control processing unit and master controller.
In order to improve the versatility of ultrasonic distance measurement obstacle avoidance system and conducive to the integration of follow-up system, which is kept awayBarrier system realizes the interconnection with other systems unit using CAN communication.Due to CAN bus have real-time is good, long transmission distance,A little convenient for node expansion, strong antijamming capability, low cost, ultrasonic distance measurement obstacle avoidance system, which can according to need, is extendedIt is integrated with other systems, to have high versatility.
The utility model has the following beneficial effects: the utility model is able to achieve multi-faceted detection and avoidance, detection is improvedSensitivity and accuracy；The used isolating transformer of ultrasonic transceiver circuit drives the ultrasonic adaptive transmitting of wave transmitting circuit cooperationPulse control, the interference being effectively isolated between each section reduce probe remained shock, utmostly improve detection range and reduction detection is blindArea, so that the maximum detectable range of the ultrasonic distance measurement obstacle avoidance system is 5m, blind area 10cm；It is real using isolation boosting transformerShow extra-high voltage driving energy converter, effectively increases the emissive porwer of ultrasonic signal；Effectively optimization circuit, sufficiently improves effectRate, so that circuit effectively improves detectivity and minimum detection blind area, maximum drive voltage is up to 160V, so that transmitting is superThe power of sound wave is sufficiently large, to realize detectivity more higher than conventional ADS driving mode；Echo processing circuit design makesSubsequent conditioning circuit processing it is simple and easy, the speed of response is effectively promoted；Remaining module uses 232 serial ports and CAN communication super to realizeChannel of acoustic wave quantity freely configure and the interconnection with other systems unit, can also the interconnection of multiple ultrasonic distance measurement obstacle avoidance systems,The interconnection of at most achievable up to 110 autonomous system units, so as to carry out the extension of ultrasonic system according to actual needsWith the integration with other systems, there is high versatility and practicability.
Detailed description of the invention
Fig. 1 is the structural block diagram of existing ultrasonic distance measurement scheme；
Fig. 2 is the echo processing circuit of existing ultrasonic distance measurement scheme；
Fig. 3 is the utility model ultrasonic distance measurement obstacle avoidance system block diagram；
Fig. 4 is the utility model ultrasonic distance measurement obstacle avoidance system range-measurement system block diagram；
Fig. 5 is the utility model ultrasonic distance measurement obstacle avoidance system echo processing circuit structural block diagram；
Fig. 6 is the utility model ultrasonic distance measurement obstacle avoidance system echo signal processing circuit diagram；
Fig. 7 is that the utility model ultrasonic distance measurement obstacle avoidance system communicates to connect structural block diagram.
Specific embodiment
As shown in figure 3, the utility model provides a kind of ultrasonic distance measurement obstacle avoidance system, including control processing unit 2, serial portsCircuit 4 and power management module 6 further include multichannel ultrasonic transmission circuit 1, CAN transmission circuit 3, wherein at the controlReason unit 2 is connected separately with ultrasonic transceiver circuit 1, serial port circuit 4, power management module 6 and CAN transmission circuit 3, describedPower management module 6 is for ultrasonic transceiver circuit 1, CAN transmission circuit 3 and the power supply for controlling processing unit 2, at the controlReason unit 2 is used to communicate and control with master controller 5 operating control of each module, and the ultrasonic transceiver circuit 1 is for detectingBarrier simultaneously measures distance, and ultrasonic transceiver circuit 1 is emitted by least three independent ultrasonic waves and received circuit and forms, eachIndependent circuits are set to the different direction of system.In view of the volume of part autonomous mobile apparatus itself is larger and ultrasonic probeThe limitation of investigative range, the probe that the utility model is evenly arranged using 6 realize three directions in front and left and right to equipmentDetection of obstacles；6 channel ultrasonic transmission circuits 1 are emitted by 6 independent ultrasonic waves and are received circuit and form, CAN transmitting-receivingDevice 3 uses TJA1051, and the power management module 6 is for ultrasonic transceiver circuit, CAN transmission circuit 3 and control processing unit2 power supply, it includes the power supply of tri- kinds of voltage of 12V, 5V, 3.3V, the input voltage range of system is 15~36V, the controlProcessing unit 2 uses STM32F103C8T6, for the operating control of each module to be communicated and controlled with master controller 5,
The schematic diagram of ultrasonic distance measurement obstacle avoidance system is as shown in figure 4,11 being transceiver ultrasonic probe in figure, 12 being receiptsHair driving circuit, 13 be echo signal processing circuit, 2 be control processing unit, 3 be CAN transceiver, 5 be master controller, 7 beBarrier.The utility model use 6 groups of independent ultrasonic transceiver circuits, 6 groups of transmission circuits all pass through control processing unit 2 intoThe control of row transmitting and signal operation processing.The advantage of scheme is isolation drive part, echo-signal compared with the existing technologyProcessing circuit part and CAN transceiver part.Reception of the driving circuit 12 for ultrasonic signal transmitting and echo-signal is received and dispatched,Circuit uses energy bleeder resistance, for discharging the dump energy after ultrasonic signal emits in coil；It further include two poles of clampPipe, the amplitude of echo-signal is limited between positive and negative 0.7V, is caused with preventing amplitude excessively high to follow-up signal processing circuitDamage；It is otherwise isolated from step-up transformer, the drive signal amplitude on right side is increased to original 10 by transformer by driving signalTimes, to increase the emissive porwer of ultrasonic signal.
As the optimization of above scheme, the driving signal of ultrasonic wave transmitting uses amplitude for 3.3V, and frequency is the arteries and veins of 40kHzSignal driving is rushed, 4~8 pulses are emitted, specific pulse number is determined according to actual use scene.Due to pulse number and ultrasoundEnergy size when wave emits is directly proportional, and pulse number is more, and the energy put aside in transformer coil is more, and ultrasonic wave is in skyThe distance propagated in gas is also farther, but can cause the increase of probe remained shock time, increases the spy of ultrasonic ranging system indirectlyBlind area is surveyed, detection range is utmostly improved using the program and is minimized detection blind area.
Echo signal processing circuit block diagram as shown in figure 5, its by primary amplifying circuit, filter circuit, secondary amplification circuit,Detection shaping circuit and five part of level shifting circuit composition.Physical circuit schematic diagram is as shown in fig. 6, transceiver ultrasonic wave is visitedHead be connected to 1 one end of first resistor, 21 other end of first resistor is connected with 22 one end of first capacitor, first capacitor 22 it is anotherEnd is connected with the inverting input terminal of the first amplifier 24；The non-inverting input terminal of first amplifier 24 is connected to the one of second resistance 23End, the other end of second resistance 23 are connected to one end of 3rd resistor 27, the other end of 3rd resistor 27 and the first amplifier 24Output end is connected；The non-inverting input terminal of first amplifier 24 is connect with one end of the second capacitor 54, the other end of the second capacitor 54Ground connection；The output end of first amplifier 24 is connected with 26 one end of the 4th resistance, and the other end of the 4th resistance 26 is connected to third electricityHold 28 one end, the other end of third capacitor 28 is connected to the inverting input terminal of the second amplifier 29；Second amplifier 29 it is same mutually defeatedEnter end to be connected with one end of the 5th resistance 27, the other end of the 5th resistance 27 is connected to the 6th resistance 30 and the 4th capacitor 31 simultaneouslyOne end after connection, the other end after the 6th resistance 30 and 31 parallel connection of the 4th capacitor are connected with the output end of the second amplifier 29；TheThe non-inverting input terminal of two amplifiers 29 is connected with one end of the second capacitor 54, the other end ground connection of the second capacitor 54；Second amplifier29 output end is connected with one end of the 7th resistance 32, and the other end of the 7th resistance 32 is connected with one end of the 5th capacitor 33It connects, the other end of the 5th capacitor 33 is connected with the inverting input terminal of third amplifier 34；The inverting input terminal of third amplifier 34 withOne end of 8th resistance 35 is connected, and the other end of the 8th resistance 35 is connected to the output end of third amplifier 34；Third amplifier 34Non-inverting input terminal on the one hand be connected with one end of the 15th resistance 52, another termination power of the 15th resistance 52 is anotherAspect is connected with one end of the 16th resistance 53, the other end ground connection of the 16th resistance 53；The output end of third amplifier 34 withOne end of 6th capacitor 36 is connected, and the other end of the 6th capacitor 36 is connected to one end of detector diode 37, detector diode37 other end is connected to the non-inverting input terminal of four high guaily unit 50；The non-inverting input terminal of four high guaily unit 50 and the 9th resistance 38 and theOne end after seven capacitors, 39 parallel connection is connected, and the other end after the 9th resistance 38 and 39 parallel connection of the 7th capacitor is connected to four high guaily unit50 inverting input terminal；On the one hand the inverting input terminal of four high guaily unit 50 connects power supply through the tenth resistance 43, on the other hand through the tenthOne resistance 42 ground connection；The output end of four high guaily unit 20 is connected with one end of zener diode 44, zener diode 44 it is anotherEnd is connected to the base stage of triode 47；One end phase after the base stage of triode 47 is in parallel with twelfth resistor 46 and the 8th capacitor 45Connection, the other end ground connection after 45 parallel connection of twelfth resistor 46 and the 8th capacitor；The emitter of triode 47 is grounded；Triode 47Collector be connected with one end of thirteenth resistor 48, another termination power of thirteenth resistor 48；Triode 47 and the tenthOne end of four resistance 49 is connected, and the other end of the 14th resistance 49 is connected to signal output end.Wherein amplifier 24,29,34,50For single supply op, it is all made of 12V power supply power supply；Power supply 41,51 is 12V power supply；Resistance 52,53 is bias bleeder resistance, isAmplifier 24,29,34 provides forward bias voltage in figure, and 54 be decoupling capacitor.21~25 constitute preamplifying circuit, and 21 be inputResistance, 22 be capacitance, and 23 be input signal pull-up resistor, and 24 be single supply op, and 25 be feedback resistance；Prime amplificationGain is determining by resistance 21 and resistance 25, forward gain 8dB；Filter capacitor 22 receives transceiver ultrasonic probeEcho-signal in low-frequency d signal filter so that preamplifying circuit only in echo-signal AC signal amplify.26~31 constitute unlimited gain multiple feedback bandpass filter, and centre frequency and pass band width pass through resistance 26,27,30 and electricityHold 28,31 to determine；The centre frequency of design is 40.1kHz, and passband gain 7dB, bandwidth is 36.918kHz~43.283kHz；32~35 constitute secondary amplification circuit, carry out secondary amplification to filtered signal to meet the requirement of subsequent processing；Circuit knotStructure is consistent with primary amplifying circuit, and the signal due to entering secondary amplifier section has been subjected to filtering, and only needing will be filteredSignal, which is amplified to, meets subsequent processing requirement；The gain of secondary amplification circuit is 15dB；Therefore amplifying circuit after treatmentOverall gain be 30dB.36~45 constitute detection shaping circuit, wherein 36~39 be detecting circuit, 41~45 be shaping circuit；36 be capacitance in detecting circuit, and 37 be detector diode, and resistance 38 and capacitor 39 constitute low-pass filter；40kHz high frequencySignal forms round and smooth envelope signal after detecting circuit；Since envelope signal is not easy to processor processing, need detectionEnvelope signal afterwards carries out Shape correction and obtains switching signal；Practical shaping circuit is 41~45 voltage comparators constituted, fortuneThe reverse side for putting 50 obtains the reference voltage of 6V by resistance 42 and the partial pressure of resistance 43, and envelope signal obtains one after comparatorDetermine the square-wave signal of pulsewidth；Zener diode 44 is for filtering out the lower interference signal of amplitude.
Since ultrasonic probe receives the intensity of echo-signal by itself to the distance and environmental factor shadow between barrierIt rings, so that the signal amplitude after handling shaping has uncertainty, is handled, examined for the ease of processorSignal amplitude after wave shaping is converted into the range that processor can use.46~50 be level shifting circuit in figure, and 46 be baseGrade pull down resistor, 47 be NPN triode, and 48 be collector pull-up resistor, and 49 be processor I/O mouthfuls of current-limiting resistance, and 50 be 3.3VPower supply；After level shifting circuit, the signal after detection shaping is converted into the switching signal that amplitude is 3.3V.Above-mentioned echo letterNumber processing circuit is only the single channel circuit in the ultrasonic distance measurement obstacle avoidance system of the utility model, and whole system is by 6 phasesWith channel composition, it is achievable to multiple directions while detect.
In order to improve the versatility of ultrasonic distance measurement obstacle avoidance system and conducive to the integration of follow-up system, which is kept awayIt is the interconnection (being not limited to robot system) of same unit that barrier system, which uses CAN communication to realize with other,.Since CAN bus hasReal-time is good, long transmission distance, convenient for node expansion, strong antijamming capability, the advantage of low cost, ultrasonic distance measurement obstacle avoidance systemIt can according to need and be extended and integrated with other systems, to have high versatility.The utility model is answeredIt is the detection of obstacles (but not limited to this) of autonomous mobile robot during the motion with scene；Master controller and ultrasoundConnection schematic diagram away from obstacle avoidance system is as shown in Figure 7.