CN2881621Y - Detector for obstacle around vehicle - Google Patents
Detector for obstacle around vehicle Download PDFInfo
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- CN2881621Y CN2881621Y CN 200620019310 CN200620019310U CN2881621Y CN 2881621 Y CN2881621 Y CN 2881621Y CN 200620019310 CN200620019310 CN 200620019310 CN 200620019310 U CN200620019310 U CN 200620019310U CN 2881621 Y CN2881621 Y CN 2881621Y
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Abstract
The utility model relates to a microwave detector, especially to a dynamic or static detection device, which mainly comprises an oscillator (201, 202), a summing circuit (203, 204), an impulse generator (205, 206), a microwave source (207, 208) a frequency mixer (212, 214), an antenna element (211), a frequency measuring unit (216), an arithmetic element (217) and a random signal generator (219). After connected by the circuit, all the components are filled in a housing and installed on the front and back collision bumper of the car or on the car top or in the lateral inside of the car. The objective of the utility model is to get the intermediate frequency echoed signal with various obstacles information through the device and then cheaply and reliably acquire different information about the neighboring obstacles through the information extraction and evaluation unit, such as the distance, speed, orientation and size, etc.
Description
Technical field
The utility model relates to a kind of microwave sounding unit, MSU, especially can be used for dynamic or static sniffer.
Background technology
The detection method that current mobility car, the crashproof sniffer of ship use mainly contains modes such as ultrasound wave, infrared ray, laser, radar Doppler, Continuous Wave with frequency modulation (FMCW) radar, pulsed radar, pattern recognition, but, therefore all can't popularize use because existing variety of way all has weakness.For example, ultrasound wave exists that detection range is near, reaction velocity is slow, have shortcoming such as serious interferences between mutually, uses in low coverage, slow astern radar at present, and under motor vehicle high speed running status, the ultrasound wave inherent defect causes and can't use.Infrared ray, laser mode are subjected to environment, weather effect big, and detecting head is subjected to dust, muddy water to cover and can't work easily, descends performance sharply to descend at severe weather conditions such as mist, rain, snow, and these inclement weathers often need most sniffer and play a role.Radar Doppler is mainly used in and tests the speed, it is relatively poor to be used under the situation of measuring machine motor-car and obstacle distance effect, and it is with high costs, the fatal shortcoming of another one is to be difficult to solve mutual interference problem between the different motor vehicles, the microwave of different motor vehicle emission different frequencies, take a large amount of frequency resources, or can't distinguish the microwave signal of different motor vehicles emission, produce serious the interference between mutually.In the high-grade abroad automobile of frequency modulated continuous wave radar actual employing is arranged, but its high cost has limited its usable range, and this method also is difficult to solve the problem of phase mutual interference between the different motor vehicles, therefore very difficult use on a large scale.Also there is the cost height in existing pulsed radar, does not solve problems such as phase mutual interference.Pattern recognition method operand is huge, and equipment cost is higher, is subjected to environment, weather effect big, descends performance seriously to descend at severe weather conditions such as mist, rain, snow.
Summary of the invention
The purpose of this utility model is intended to overcome the deficiencies in the prior art, provides that a kind of detection range is far away, measuring accuracy is high, is not subjected to environment, the sniffer that is used for peripheral obstacle for motor vehicle of weather effect, no phase mutual interference.
The sniffer that is used for peripheral obstacle for motor vehicle described in the utility model is mainly by forming with lower member: oscillator (201,202), summing circuit (203,204), pulse producer (205,206), microwave source (207,208), frequency mixer (212,214), antenna element (211), frequency measurement unit (216), arithmetic element (217), random signal generator (219), the output terminal of oscillator (201) is connected with the first input end of summing circuit (203), the output terminal of summing circuit (203) is connected with the input end of pulse producer (205), the output terminal of pulse producer (205) is connected with the input end of microwave source (207), be connected with the first input end of frequency mixer (214) simultaneously, the output terminal of frequency mixer (214) is connected with the input end of frequency measurement unit (216), the output terminal of frequency measurement unit (216) is connected with the input end of computing unit (217), the result of calculation of computing unit (217) output time amplification coefficient, output terminal while and summing circuit (203) of random signal generator (219), (204) second input end connects; The output terminal of microwave source (207) is connected with the input end of emitting antenna, transmission antennas transmit microwave pulse signal, receiving antenna receives the reflected signal from peripheral obstacle, the output terminal of receiving antenna is connected with the first input end of frequency mixer (212), the output terminal of oscillator (202) is connected with the first input end of summing circuit (204), the output terminal of summing circuit (204) is connected with the input end of pulse producer (206), the output terminal of pulse producer (206) is connected with the input end of microwave source (208), be connected with second input end of frequency mixer (214) simultaneously, the output terminal of microwave source (208) is connected with second input end of frequency mixer (212), the output terminal output echo signal of intermediate frequency of frequency mixer (212).
Above-mentioned all circuit can be packed in the housing, are installed on bumper before and after the automobile, roof, car side, fix with screw or viscose glue, and the antenna element direction can be installed on the inboard of nonmetal bumper outwardly, also can be installed on the windshield inboard.Requirement antenna element the place ahead does not have the automobile metal housing or parts block, but non-metallic objectsit is not a metal object can be arranged, as plastics or fiberglass bumper, windshield etc.Always be output as two interfaces, an analog interface--output echo signal of intermediate frequency (simulating signal), digital interface result of calculation of--output computing unit (217)--time amplification coefficient (digital quantity), measurement result--differential signal frequency (digital quantity) that also can output frequency measuring unit (216).Above-mentioned all circuit also can be used as other network component and are used.
Said apparatus has used emission, has received a plurality of antennas separately, and promptly antenna element has comprised at least two antennas, and some are used for emission, and some are used for receiving.Also can launch, receive a shared antenna, should increase directional coupler (210) in such cases, the output terminal of microwave source (207) is connected with the input end of directional coupler (210), the coupled end of directional coupler (210) is connected with the input/output terminal of antenna element (211), and the output terminal of directional coupler (210) is connected with the first input end of frequency mixer (212).
The main effect of frequency mixer (214) is differential signal of output, its input end and the nonessential output terminal that connects pulse producer, following three kinds of connected modes can also be arranged, the first input end that is frequency mixer (214) is connected with the output terminal of oscillator (201), and second input end is connected with the output terminal of oscillator (202) simultaneously; Perhaps the first input end of frequency mixer (214) is connected with the output terminal of summing circuit (203), and second input end is connected with the output terminal of summing circuit (204) simultaneously; Perhaps the first input end of frequency mixer (214) is connected with the output terminal of microwave source (207), and second input end is connected with the output terminal of microwave source (208) simultaneously.
Main task of the present utility model is to generate a kind of echo signal of intermediate frequency, can be cheap and estimate the information of barrier reliably by this echo signal of intermediate frequency, as each the corresponding motor vehicle in the position of value on time shaft of echo signal of intermediate frequency and the distance of barrier, the amplitude of each value has or not corresponding to barrier and the size of barrier, each value in time the situation of change on distribution, amplitude, phase place corresponding to information such as the relative velocity of motor vehicle and barrier, directions.By extracting these information, and then accurately assess out the threat that barrier constitutes the motor vehicle security of operation.Task of the present utility model only is to generate this echo signal of intermediate frequency, and extracts from echo signal of intermediate frequency, assesses which information, and how to extract, task that appreciation information is not this patent.Well-known reason, the method for extraction, appreciation information is varied, and is known by the relevant speciality personage, so the change of these methods does not influence the effectiveness of this patent.For simplicity of exposition, unless specialize, in this paper narration, motor vehicle, ship all use motor vehicle one speech to explain, and barrier and close object all use barrier one speech to explain.
Distinctive feature of the present utility model is to utilize this device to generate a kind of echo signal of intermediate frequency, utilize this echo signal of intermediate frequency, anticollision device for vehicle can be by the information that is dirt cheap and mode is extracted barrier reliably, and can guarantee very high measuring accuracy, thereby accurately assess barrier to the threat that vehicle operational safety causes, in time report to the police and/or take workaround.
Description of drawings
Fig. 1 is the sniffer that is installed on the motor vehicle.
Fig. 2 is the utility model circuit side connector block diagram.
Fig. 3 is a kind of specific embodiment of the utility model summing circuit.
Fig. 4 is a kind of specific embodiment of the utility model pulse producer.
Fig. 5 is a kind of specific embodiment of the utility model wave filter.
Fig. 6 is a kind of specific embodiment of the utility model random signal generator.
Fig. 7 is for when oscillator 201,202 being sine-wave oscillator, pulse producer 205,206 when being squarer, the mutual relationship between the output signal 223,224,225,226,227,228,233.
Fig. 8 is the waveform synoptic diagram of the echo signal of intermediate frequency of the utility model generation.
Embodiment
Fig. 1 shows one and is installed on sniffer on the motor vehicle 101, that be used for anticollision of motor vehicles.This device has a circuit unit 102 and an antenna element 103, circuit unit 102 at first produces a kind of microwave pulse signal, launch this microwave pulse signal by the direction 105 that antenna element 103 is measured to needs, when running into barrier 104, the microwave pulse signal of emission produces signal reflex, reflection direction 106 is opposite with transmit direction 105, antenna element 103 receives the microwave pulse signal of reflection, the reflected microwave pulse of 102 pairs of receptions of circuit unit is handled, generate the front and discuss the echo signal of intermediate frequency of mentioning with the various information of barrier, on this basis circuit unit 102 can have but and the nonessential extraction appreciation information that has, and the function of warning and Control of Automobile operation.Arrow shows the travel path of microwave pulse signal among Fig. 1.Antenna element 103 is not that expression has only an antenna among Fig. 1, this antenna element can be to transmit and receive a shared antenna, also can be to transmit and receive the antenna array that two or more antennas are separately formed, the form of antenna can be the known any antennas of industry such as element antenna, shaft-like guided wave antenna, electromagnetic horn, parabola antenna, little band flat plane antenna, the utility model can adopt the independent or combination realization antenna element 103 of wherein any or multiple antenna, there is no special requirement, for example can adopt electromagnetic horn.The realization technology of these antenna is known by industry, and the specific implementation technology maturation does not have the difficulty of realization yet, and therefore adopting which kind of antenna form is not main task of the present utility model, does not influence effectiveness of the present utility model yet.
Fig. 2 shows a kind of form of implementation of the sniffer that is used for motor vehicle that constitutes according to the utility model.This circuit should comprise two oscillators 201,202 at least, two summing circuits 203,204,207,208, two frequency mixer 212,214 of 205,206, two microwave sources of two pulse producers, a frequency measurement unit 216,219, one antenna elements 211 of 217, one random signal generators of a computing unit, antenna element 211 can be made up of emission, a shared antenna of reception, also can be made up of emission, reception several antennas separately.
When antenna unit 211 by emission, when reception a plurality of antennas are separately formed, the most basic connected mode is between each parts, the output terminal of oscillator 201 is connected with the first input end of summing circuit 203, the output terminal of summing circuit 203 is connected with the input end of pulse producer 205, the output terminal of pulse producer 205 is connected with the input end of microwave source 207, be connected with the first input end of frequency mixer 214 simultaneously, the output terminal of microwave source 207 is connected with the input end of emitting antenna, transmission antennas transmit microwave pulse signal, receiving antenna receives reflected signal, the output terminal of receiving antenna is connected with the first input end of frequency mixer 212, the output terminal of oscillator 202 is connected with the first input end of summing circuit 204, the output terminal of summing circuit 204 is connected with the input end of pulse producer 206, the output terminal of pulse producer 206 is connected with the input end of microwave source 208, be connected with second input end of frequency mixer 214 simultaneously, the output terminal of microwave source 208 is connected with second input end of frequency mixer 212, the output terminal output echo signal of intermediate frequency of frequency mixer 212, the output terminal of frequency mixer 214 is connected with the input end of frequency measurement unit 216, the output terminal of frequency measurement unit 216 is connected with the input end of computing unit 217, the result of calculation of computing unit 217 output time amplification coefficients, the output terminal of random signal generator 219 is connected with second input end of summing circuit 203, is connected with second input end of summing circuit 204 simultaneously.
When antenna unit 211 by emission, when receiving a shared antenna and forming, must dispose directional coupler 210.In this case, the output terminal of microwave source 207 is connected with the input end of directional coupler 210, and the coupled end of directional coupler is connected with the input/output terminal of antenna element 211, and the output terminal of directional coupler is connected with the first input end of frequency mixer 212.
It is f that this device disposes an oscillation frequency
sOscillator 201, the output terminal of oscillator 201 is connected f with the first input end of summing circuit 203
sScope can be hundreds of KHz to hundreds of MHz, in general be preferably several MHz.This oscillator can be the oscillator of any forms such as sine-wave oscillator, triangular wave oscillator, saw-toothed oscillator, square-wave oscillator, can be a quartz oscillator with high stability for instance.A kind of specific implementation of oscillator 201 is to use VX20 series voltage control crystal oscillator to realize, VX20 series voltage control crystal oscillator has covered 0.5MHz to the 100MHz frequency range, supply voltage is 5V, frequency stability ± 5ppm, this oscillator also disposes a voltage-controlled voltage input end, voltage-controlled voltage range is 2.5 ± 2V, the voltage controlled frequency scope is ± and 30ppm～± 150ppm.The voltage-controlled voltage input end of oscillator 201 can be connected (under the situation that has disposed frequency control unit 218) with the output terminal of frequency control unit 218, and then oscillator frequency can be subjected to output control signal 240 control of frequency control unit 218 within the specific limits and changes, also can connect a fixed voltage, and then produce the vibration of frequency stabilization.The implementation method of oscillator is known by industry, and the various specific implementation method of oscillator does not influence effectiveness of the present utility model.
This device also disposes a summing circuit 203, the first input end of summing circuit 203 is connected with the output terminal of oscillator 201, second input end is connected with the output terminal of random signal generator 219, and the output terminal of summing circuit 203 is connected with the input end of pulse producer 205.Summing circuit 203 is output as the stack of the oscillator signal and the voltage signal at random that random signal generator 219 is exported of oscillator 201 outputs, the output signal frequency of summing circuit 203 is identical with oscillator frequency, only be subjected to the influence of the voltage signal at random of random signal generator 219 outputs, the output signal of summing circuit 203 is compared with the outputting oscillation signal of oscillator 201, and its zero crossing produces small randomized jitter.Summing circuit can be realized by multiple mode.Fig. 3 shows a kind of specific embodiment of summing circuit 203, and this summing circuit comprises an integrated transporting discharging 301 and 5 resistance R
1, R
2, R
3, R
4, R
5, 302 is the summing circuit first input end among the figure, and 303 is summing circuit second input end, and 304 is the summing circuit output terminal.The implementation method of summing circuit is known by industry, and the various specific implementation method of summing circuit does not influence effectiveness of the present utility model.
This device also disposes a pulse producer 205, and the input end of pulse producer 205 is connected with the output terminal of summing circuit 203, and the output terminal of pulse producer 205 is connected with the input end of microwave source 207, is connected with the first input end of frequency mixer 214 simultaneously.This pulse producer produces frequency and is all f under the control of the output signal 223 of summing circuit 203
sBurst pulse, pulse width can for several nanoseconds at zero point between several microseconds, in general be preferably several nanoseconds.Pulse producer can be realized by multiple mode, can be made of the high speed d type flip flop for instance, and then the zero crossing place of the oscillator signal 223 that produces at oscillator 201 produces burst pulse.Fig. 4 shows a kind of specific embodiment of pulse producer 205, and this pulse producer comprises a Schmidt trigger 401 and a d type flip flop 402, and 403 is the input end of pulse producer among the figure, and 405 is the output terminal of pulse producer.Schmidt trigger 401 produces square wave at the zero crossing place of input signal, square wave frequency is identical with frequency input signal, the square wave 404 of Schmidt trigger 401 outputs connects the CLK end of d type flip flop 402, at each square wave rising Yan Chu, d type flip flop produces upset, this moment, the Q output terminal of d type flip flop was output as high level, the Q end of d type flip flop is output as low level, because the Q end directly connects the CLR clear terminal of d type flip flop, therefore the Q output terminal becomes low level at once again, thereby produce very narrow pulse output at the Q output terminal, pulse width depends on that the device of d type flip flop postpones, for the high speed d type flip flop, device postpones generally to have only several nanoseconds, and therefore can produce width only is the ultra-narrow pulse of several nanoseconds.The implementation method of pulse producer is known by industry, and the various specific implementation method of pulse producer does not influence effectiveness of the present utility model.
This device also disposes a microwave source 207, the input end of microwave source 207 is connected with the output terminal of pulse producer 205, the output terminal of microwave source 207 be directly connected to emitting antenna (when use emission, when receiving a plurality of antenna separately), perhaps the input end with directional coupler 210 is connected (when the shared antenna of emission, reception).The output pulse signal 225 controlled microwave sources 207 of pulse producer 205 produce microwave pulses, for instance can be by exciting such as avalanche diode, and then produce microwave pulse.Pulse signal 225 can also be the form of power supply power supply, powers by giving the micro-wave resonator circuit that is made of triode or CMOS pipe etc., and then produces microwave pulse.Pulse signal 225 can also be the form of trigger pip, the conducting in controlled microwave source 207 or disconnection, for instance, microwave source 207 is in oscillatory regime all the time, and dispose a gating circuit, and this gating circuit conducting or disconnection under the control of pulse signal 225.The oscillation frequency f of microwave source 207
hCan for hundreds of MHz between tens GHz, in general be preferably in several GHz between tens GHz.A concrete microwave source realizes that example is, adopt the ultralow directly synthetic microwave source of making an uproar mutually of X-band UDS series, utilize the break-make of a microwave switch of output pulse signal 225 controls of pulse producer 205, and then produce microwave pulse output 227, the microwave pulse carrier frequency is 10.525GHz.The implementation method of microwave source is known by industry, and the various specific implementation method of microwave source does not influence effectiveness of the present utility model.
The microwave pulse that microwave source 207 produces can directly be exported, also can be by exporting behind the filter filtering, and the effect of this wave filter is to reduce high order association wave interference, and this wave filter is also nonessential, and can have not to have yet.A specific embodiment of wave filter is for adopting JEB-X-
*Series of parallel coupling line bandpass filter module realizes that this series wave filter operating frequency range covers 8GHz～12GHz, and the 3dB relative bandwidth is 5%～20%, can satisfy the filtering requirements of the microwave pulse signal of 10.525GHz fully.The implementation method of wave filter is known by industry, and the various specific implementation method of wave filter does not influence effectiveness of the present utility model.
This device also disposes an antenna element 211, antenna element can be made of emission, reception several antennas separately, also can constitute by emission, a shared antenna of reception, the form of antenna can be the known any antennas of industry such as element antenna, shaft-like guided wave antenna, electromagnetic horn, parabola antenna, little band flat plane antenna, the utility model can adopt the independent or combination realization antenna element 103 of wherein any or multiple antenna, there is no special requirement, for example can adopt electromagnetic horn.A kind of specific embodiment of antenna element is, realize as emission, a shared antenna of reception by a HD-100SHA22.1 pattern field electromagnetic horn, this electromagnetic horn frequency of operation is 8.2～12.4GHz, satisfies the need of work of 10.525GHz microwave pulse fully.The specific embodiment of another antenna element is, realized by two HD-100SHA22.1 pattern field electromagnetic horns, and one as emitting antenna, and one as receiving antenna.The implementation method of antenna is known by industry, and the various specific implementation method of antenna does not influence effectiveness of the present utility model.
When antenna unit 211 is by emission, when reception several antennas separately constitute, antenna is penetrated in the microwave pulse output 227 direct sending and receiving that microwave source 207 produces, emitting antenna is transmitted into microwave pulse the direction 231 that needs detection, the microwave pulse of emission forms reflection after running into barrier, reflection direction 232 is opposite with transmit direction, receive the microwave pulse signal that reflects by receiving antenna, output to the first input end of frequency mixer 212 again.
When antenna unit 211 is by emission, when a shared antenna of reception constitutes, this device also disposes a directional coupler 210, the input end of directional coupler 210 is connected with the output terminal of microwave source 207, the coupled end of directional coupler is connected with the input/output terminal of antenna, the coupled end that is directional coupler promptly can be exported the launched microwave pulse signal to antenna, simultaneously also can be from the reflected microwave pulse signal of antenna input reception, the output terminal of directional coupler is connected with the first input end of frequency mixer 212.The launched microwave pulse signal is imported from the input end of directional coupler, and exports from the coupled end of directional coupler, is launched by antenna again.Antenna receives the reflected microwave pulse signal simultaneously, by antenna output, again by the coupled end input of directional coupler, is outputed to the first input end of frequency mixer 212 again by the output terminal of directional coupler.The implementation method of directional coupler is a lot, can be any modes such as microstrip directional coupler, cavity directional coupler, coaxial directional coupler.A kind of concrete directional coupler embodiment is, adopts the AV70701 coaxial directional coupler to implement, and this directional coupler operating frequency range is 2～40GHz, can satisfy the need of work of 10.525GHz microwave pulse fully.The implementation method of directional coupler is known by industry, and the various specific implementation method of directional coupler does not influence effectiveness of the present utility model.
This device can dispose a power amplifier 209, and to increase emissive power and detection range, this power amplifier is also nonessential, and can have not to have yet.When having disposed power amplifier 209, the input end of power amplifier 209 is connected with the output terminal of microwave source 207, the output terminal of power amplifier be directly connected to emitting antenna (when use emission, when receiving a plurality of antenna separately), perhaps the input end with coupling mechanism 210 is connected (when the shared antenna of emission, reception).A specific embodiment of power amplifier is realized for adopting X-band MAAPGM0034-DIE power amplifier module, this power amplifier module operating frequency range is 8～12.5GHz, and satisfying carrier frequency fully is the power amplification requirement of the microwave pulse signal of 10.525GHz.The implementation method of power amplifier is known by industry, and the various specific implementation method of power amplification does not influence effectiveness of the present utility model.
It is f that this device also disposes an oscillation frequency
rOscillator 202, the output terminal of oscillator 202 is connected with the input end of summing circuit 204.The surge frequency range of oscillator 202 is identical with the surge frequency range of oscillator 201, but with the oscillation frequency f of oscillator 201
sDifference on the frequency Δ f, wherein a Δ f=f are arranged
s-f
r, Δ f can be tens Hz for instance.Identical with oscillator 201, oscillator 202 also can have multiple specific implementation form.A kind of specific embodiment of oscillator 202 is with oscillator 201.The oscillation frequency of oscillator 202 can but and nonessential suspension control signal 240 controls.
This device also disposes a summing circuit 204, the first input end of summing circuit 204 is connected with the output terminal of oscillator 202, second input end is connected with the output terminal of random signal generator 219, and the output terminal of summing circuit 204 is connected with the input end of pulse producer 206.Identical with summing circuit 203, summing circuit 204 also can have multiple specific implementation form.A kind of specific embodiment of summing circuit 204 is with summing circuit 203.
This device also disposes a pulse producer 206, and the input end of pulse producer 206 is connected with the output terminal of summing circuit 204, and output terminal is connected with the input end of microwave source 208, is connected with second input end of frequency mixer 214 simultaneously.Pulse producer 206 forms frequency and is all f under the control of the output signal 224 of summing circuit 204
rBurst pulse.Identical with pulse producer 205, pulse producer 206 also can have multiple way of realization.A kind of specific embodiment of pulse producer 206 is with pulse producer 205.
This device also disposes a microwave source 208, and the input end of microwave source 208 is connected with the output terminal of pulse producer 206, and output terminal is connected with second input end of frequency mixer 212.Microwave source 208 produces microwave pulse 228 under the control of the pulse output 226 of pulse producer 206.Identical with microwave source 207, microwave source 208 also can have multiple way of realization.A kind of specific embodiment of microwave source 208 is with microwave source 207.
This device also disposes a frequency mixer 212, the first input end of frequency mixer 212 is connected (when the use emission, when receiving a plurality of antenna that separates) with receiving antenna, perhaps the output terminal with directional coupler 210 is connected (when emission, when receiving a shared antenna), second input end of frequency mixer 212 is connected with the output terminal of microwave source 208, the output terminal output echo signal of intermediate frequency of frequency mixer 212.The microwave pulse signal 228 of reflected microwave pulse signal that antenna receives and microwave source 208 outputs produces intermediate-freuqncy signal output 234, the centre frequency f of intermediate-freuqncy signal 234 in frequency mixer 212 mixing
zOscillation frequency f with oscillator 201
s, oscillator 202 oscillation frequency f
rAnd the carrier frequency f of microwave source 207
hRelevant, computing formula is:
By appropriate design f
r, f
s, f
h, can produce the centre frequency f of suitable intermediate-freuqncy signal
z, be generally tens to hundreds of KHz for instance.Frequency mixer has multiple way of realization, can be any forms such as double balanced mixer, three balanced mixers, analog multiplier.A kind of specific embodiment of frequency mixer 212 realizes that for adopting the JDM-0711 double balanced mixer this frequency mixer operating frequency range is 6GHz～11GHz, and mixing is output as DC～2GHz, satisfies the need of work of 10.525GHz microwave pulse fully.The implementation method of frequency mixer is known by industry, and the various specific implementation method of frequency mixer does not influence effectiveness of the present utility model.
This equipment can dispose a wave filter 213, and with the association of the high order in the intermediate-freuqncy signal 234 that reduces frequency mixer 212 outputs wave interference, this wave filter is also nonessential, and can have not to have yet.When having disposed wave filter 213, the input end of wave filter 213 is connected with the output terminal of frequency mixer 212, the output terminal output intermediate-freuqncy signal 235 of wave filter 213.Wave filter 213 can be bandpass filter, also can be low-pass filter, and when being bandpass filter, the filter center frequency should be f
z, when being low-pass filter, wave filter should be greater than f by frequency
z, f here
zBe the centre frequency of the intermediate-freuqncy signal 234 of frequency mixer 212 output, the centre frequency of the intermediate-freuqncy signal 235 of wave filter 213 outputs still is f
zWave filter 213 can have the implementation method of various ways, can be any forms such as LC wave filter, active RC filter, quartz-crystal filter, Surface Acoustic Wave Filter.Fig. 5 shows a kind of specific embodiment of wave filter 213, the Active RC low-pass filter that this wave filter is made up of integrated transporting discharging 501 and R, C network, and 502 is the input end of wave filter among the figure, and 503 is the output terminal of wave filter, and it is f by frequency
0=1/2 π R
7C
1, enlargement factor is A=1+R
8/ R
6, suitably design R according to the centre frequency of intermediate-freuqncy signal
6, R
7, R
8And C
1, the requirement of the frequency filtering that wave filter is satisfied discuss above, and suitable enlargement factor A is set as required gets final product.The implementation method of wave filter is known by industry, and the various implementation method of wave filter does not influence effectiveness of the present utility model.
Intermediate-freuqncy signal 235 and/or intermediate-freuqncy signal 234 are that the utility model will generate has the various information of barrier as the echo signal of intermediate frequency of distance, speed, orientation, size etc.
This device also disposes a frequency mixer 214, the first input end of frequency mixer 214 is connected with the output terminal of pulse producer 205, second input end of frequency mixer 214 is connected with the output terminal of pulse producer 206, and the output terminal of frequency mixer 214 is connected with the input end of frequency measurement unit 237.The output signal 225 of pulse producer 205 and the output signal 226 of pulse producer 206 are in frequency mixer 214 mixing, produce a differential signal 236 that frequency is Δ f, Δ f is the difference frequency of the oscillation frequency of the oscillation frequency of oscillator 201 and oscillator 202, i.e. Δ f=f
s-f
rThe connected mode of frequency mixer 214 can also be following three kinds of modes, the first input end of frequency mixer 214 is connected with the output terminal of oscillator 201, second input end is connected with the output terminal of oscillator 202 simultaneously, perhaps the first input end of frequency mixer 214 is connected with the output terminal of summing circuit 203, second input end is connected with the output terminal of summing circuit 204 simultaneously, perhaps the first input end of frequency mixer 214 is connected with the output terminal of microwave source 207, second input end is connected with the output terminal of microwave source 208 simultaneously, and these connected modes also can produce the differential signal 236 that frequency is Δ f.Frequency mixer 214 can have the implementation of various ways, can be Analogue mixer, also can be digital mixer, for instance, can be a digital AND circuit, or the digital circuit that is made of trigger circuit such as d type flip flops.A specific embodiment of frequency mixer 214 is to realize with door with one the two single output numeral of input, numeral is connected with the output terminal of pulse producer 205 with the first input end of door, second input end is connected with the output terminal of pulse producer 206, only when two input signals of frequency mixer 214 are high level simultaneously, frequency mixer output just is high level, and then realizes the digital mixing function.The implementation method of Analogue mixer and digital mixer is known by industry, and the different specific implementation methods of frequency mixer do not influence effectiveness of the present utility model.
This device can dispose a wave filter 215, and to reduce the high order association wave interference in the differential signal 236, this wave filter is also nonessential, and can have not to have yet.When having disposed wave filter 215, the input end of wave filter 215 is connected with the output terminal of frequency mixer 214, and output terminal is connected with the input end of frequency measurement unit 216.Wave filter 215 can have the implementation method of various ways, can be any forms such as LC wave filter, active RC filter, quartz-crystal filter, Surface Acoustic Wave Filter.A kind of specific embodiment of wave filter 215 is with wave filter 213.
This device also disposes a frequency measurement unit 216, the input end of frequency measurement unit 216 is connected (when not disposing wave filter 215) with the output terminal of frequency mixer 214, perhaps the output terminal with wave filter 215 is connected (when configuration wave filter 215), and the output terminal of frequency measurement unit 216 is connected with the input end of arithmetic element 217.Frequency measurement unit 216 is used to measure the frequency Δ f of differential signal.Frequency measurement unit 216 can be by implemented in many forms such as frequency discriminator or FFT computing or counting circuits.Specific embodiment realizes for the timer that uses single-chip microcomputer 243 generally to have, and by the time timing between continuous two risings are prolonged to differential signal, and then calculates the frequency of differential signal.The implementation method of frequency measurement is known by industry, and the different specific implementation methods of frequency measurement unit do not influence effectiveness of the present utility model.
This device also disposes an arithmetic element 217, and the input end of arithmetic element 217 is connected with the output terminal of frequency measurement unit 216, the time amplification coefficient that output terminal output is calculated.Arithmetic element 217 is according to the oscillation frequency f of known oscillator 201
sAnd the differential signal frequency Δ f that measures of frequency measurement unit 216, calculating a parameter beta that is called the time amplification coefficient, computing formula is β=f
s/ Δ f, time magnificationfactor will be used for the information extraction and the assessment of echo signal of intermediate frequency.Arithmetic element can realize with a computing circuit, also can realize with software.A specific embodiment of arithmetic element is for using single-chip microcomputer 243 programmings and then realizing by software.The implementation method of arithmetic element is known by industry, and the different specific implementation methods of arithmetic element do not influence effectiveness of the present utility model.
This device can dispose a frequency control unit 218, and with the oscillation frequency of control generator 202, frequency control unit is also nonessential, and can have not to have yet.The input end of frequency control unit 218 is connected with the output terminal of arithmetic element 217, and perhaps the output terminal with frequency measurement unit 216 is connected, and output terminal is connected with the voltage-controlled voltage input end of oscillator 202.Frequency control unit 218 time magnificationfactor that 217 computings obtain according to arithmetic element or the differential frequency Δ f that measures according to frequency measurement unit 216 produce with the time magnificationfactor or with differential frequency Δ f and are the control signal output 240 of proportionate relationship.The oscillation frequency of control signal 240 control generators 202 makes the oscillation frequency of oscillator 202 keep within limits and/or variation as required, and then differential frequency Δ f is kept within limits and/or variation as required.For instance, oscillator 202 is voltage controlled oscillators, the output of frequency control unit 218 is a voltage signal at this moment, and voltage is magnificationfactor or differential frequency Δ f linear change in time, and the oscillation frequency of oscillator 202 is subjected to this Control of Voltage and changes.Control signal 240 is control generator 202 not also, and is used for control generator 201, and mode is identical with control generator 202.Frequency control unit 218 can be realized by multiple mode, D/A converter or the PWM function that can utilize single-chip microcomputer 243 generally to have for instance realize, also can discharge and recharge control signal, and then control outside charge-discharge circuit and realize by exporting by single-chip microcomputer 243.A specific embodiment is that the D/A converter that utilizes single-chip microcomputer generally to have is realized, Single Chip Microcomputer (SCM) program is according to the time magnification β that calculates, by the certain control voltage of D/A converter output, the D/A converter output terminal is connected with the voltage-controlled voltage input end of previously described VX20 series voltage control crystal oscillator, and then reaches the purpose of control generator frequency.Control method for frequency is known by industry, and the specific implementation of different frequency control method does not influence effectiveness of the present utility model.
This device also disposes a random signal generator 219, and the output terminal of random signal generator 219 is connected with second input end of summing circuit 203, is connected with second input end of summing circuit 204 simultaneously.The control signal 241 of the output of random signal generator 219 can be so that the phase place of the outputting oscillation signal 221,222 of oscillator 201,202 or zero crossing produce identical small randomized jitter, and then the position of pulse signal on time shaft that pulse producer 205,206 is produced produces identical small randomized jitter.For instance, control signal 241 is a small voltage at random, with this at random voltage be added to simultaneously on the oscillator signal of oscillator 201,202, and then make the zero crossing of oscillator signal produce small randomized jitter.Random signal generator 219 can be realized by multiple mode, can produce pseudorandom M sequence by single-chip microcomputer 243 programmings or by the external shift register circuit for instance, this pseudorandom M sequence is by the small at random voltage of outside integrating circuit generation with the M sequence variation.Because the probability of the random series that overlaps fully on the different device generation time is very low, therefore this mechanism can be cheap and eliminate phase mutual interference between the collision avoidance system that is installed on the different motor vehicles reliably.Fig. 6 shows a kind of specific embodiment of random signal generator 219, and 602 is the output terminal of random signal generator 219 among the figure.The M random series that an I/O mouth of single-chip microcomputer 243 prestores according to program, serial 0,1 random series of circular order ground output regularly, 0 level accordingly, 1 corresponding high level, this output sequence is through by R
9And C
2The integrating circuit that constitutes is created in the voltage signal at random of random fluctuation between ground level and the high level, this emitter follower output of constituting through integrated transporting discharging 601 of voltage signal at random.The production method of random signal is known by industry, and the specific implementation of distinct methods does not influence effectiveness of the present utility model.
The final echo signal of intermediate frequency 235 or 234 that produces is sent into an information extraction assessment unit 220, information extraction assessment unit 220 binding time magnificationfactors and/or differential frequency Δ f, extract and assess the information of barrier, and output alarm and/or control signal 242.Information extraction assessment unit 220 can utilize single-chip microcomputer 243 programmings to realize, also can realize that this is not to be required finishing of the task of the utility model by certain circuit.
Fig. 7 show when oscillator 201,202 for sine-wave oscillator, pulse producer 205,206 during for squarer, the mutual relationship between the output signal 223,224,225,226,227,228,233.X axle express time wherein, the y axle is represented signal amplitude.701 is the waveform signal of the output 223 of summing circuit 203,702 is the waveform signal of the output 224 of summing circuit 204,703 is the waveform signal of the output 225 of pulse producer 205,704 is the waveform signal of the output 226 of pulse producer 206,705 is the waveform signal of the output 227 of microwave source 207,706 is the waveform signal of the output 228 of microwave source 208, and 707 is the waveform signal of the output 233 of directional coupler 210.708,709 is the launched microwave pulse leaks into output terminal by the input end of directional coupler 210 microwave pulse signal, this be since actual directional coupler can not accomplish input and output isolate fully cause, microwave pulse 708,709 is littler than the microwave pulse of emission, but significantly greater than reflected microwave pulse 710,711.710,711 microwave pulse signals, reflected signal for the reflection of the barrier that receives generally all a little less than.T
sBeing the oscillation period of oscillator 201, is the oscillation frequency f of oscillator 201
sInverse, T
rBeing the oscillation period of oscillator 202, is the oscillation frequency f of oscillator 202
rInverse, Δ T is the difference DELTA T=T of the oscillation period of two oscillators
r-T
s, Δ T is generally very little.Δ t is a microwave pulse from the time that barrier reflects.As everyone knows, electromagnetic wave is constantly equal to light velocity C in the velocity of propagation of free space, if can accurately measure Δ t, the distance that just can calculate between barrier 104 and the motor vehicle is l=Δ t * C/2, and wherein C is the light velocity.The barrier of calculating by double surveymeter and the variation of motor vehicle distance just can calculate the relative velocity of barrier and motor vehicle.But in actual conditions, because the light velocity is very fast, so Δ t is very little, is very difficult so directly measure Δ t and will keep certain measuring accuracy.For instance, the distance of supposing barrier and motor vehicle is 10 meters, this moment, Δ t only was 66.667 nanoseconds, if require measuring accuracy to reach 1 millimeter, the minute differences that needs 0.006 nanosecond of device energy measurement Δ t so, this measurement is very difficult, enables promptly to accomplish that equipment cost also can be very high.
Fig. 8 shows the signal of the echo signal of intermediate frequency of the utility model generation.X axle express time wherein, the y axle is represented signal amplitude.801 corresponding directional couplers leak into the launched microwave pulse signal 708 of output terminal or the microwave pulse signal 710 or 711 of 709,802 corresponding barrier reflections, Δ t among the figure
zCorresponding microwave pulse is from the time Δ t that barrier reflects, Δ t
zWith the corresponding relation of Δ t be Δ t
z=β * Δ t, wherein β is the time amplification coefficient, be equivalent to Δ t and in the echo signal of intermediate frequency that the utility model generates, be exaggerated β doubly, since the equivalent time amplification, Δ t
zBe easy to measuredly, and then calculate Δ t, and then calculate the distance between motor vehicle and the barrier.Utilize the utility model, the direct measurement to Δ t can be converted to Δ t
zIndirect measurement, this indirect measurement can be dirt cheap and realize reliably.For instance, if time magnificationfactor=10
5, the distance of supposing barrier and motor vehicle is 10 meters, at this moment Δ t
zBe 6.667 milliseconds,, only need measurement mechanism energy measurement Δ t if require measuring accuracy to reach 1 millimeter
zThe difference of 0.6 microsecond, this measurement just can be easily with low speed very and cheap device is realized, and can guarantee very high measuring accuracy.Simultaneously amplitude, the phase place of 802 amplitude, phase place and actual reflected microwave pulse signal 710 or 711 also have linear corresponding relation, owing to the equivalent time amplification, the measurement of reflected signal amplitude, phase place are also become easy.
Claims (9)
1, a kind of sniffer that is used for peripheral obstacle for motor vehicle, it is characterized in that mainly by forming: oscillator (201 with lower member, 202), summing circuit (203,204), pulse producer (205,206), microwave source (207,208), frequency mixer (212,214), antenna element (211), frequency measurement unit (216), arithmetic element (217) and random signal generator (219), the output terminal of oscillator (201) is connected with the first input end of summing circuit (203), the output terminal of summing circuit (203) is connected with the input end of pulse producer (205), the output terminal of pulse producer (205) is connected with the input end of microwave source (207), be connected with the first input end of frequency mixer (214) simultaneously, the output terminal of frequency mixer (214) is connected with the input end of frequency measurement unit (216), the output terminal of frequency measurement unit (216) is connected with the input end of computing unit (217), the result of calculation of computing unit (217) output time amplification coefficient, output terminal while and summing circuit (203) of random signal generator (219), (204) second input end connects; The output terminal of microwave source (207) is connected with the input end of emitting antenna, transmission antennas transmit microwave pulse signal, receiving antenna receives the reflected signal from peripheral obstacle, the output terminal of receiving antenna is connected with the first input end of frequency mixer (212), the output terminal of oscillator (202) is connected with the first input end of summing circuit (204), the output terminal of summing circuit (204) is connected with the input end of pulse producer (206), the output terminal of pulse producer (206) is connected with the input end of microwave source (208), be connected with second input end of frequency mixer (214) simultaneously, the output terminal of microwave source (208) is connected with second input end of frequency mixer (212), the output terminal output echo signal of intermediate frequency of frequency mixer (212).
2, the sniffer that is used for peripheral obstacle for motor vehicle as claimed in claim 1, it is characterized in that emission, receive a shared antenna, directional coupler (210) is being set in such cases, the output terminal of microwave source (207) is connected with the input end of directional coupler (210), the coupled end of directional coupler (210) is connected with the input/output terminal of antenna element (211), and the output terminal of directional coupler (210) is connected with the first input end of frequency mixer (212).
3, the sniffer that is used for peripheral obstacle for motor vehicle as claimed in claim 1 is characterized in that the first input end of frequency mixer (214) is connected with the output terminal of oscillator (201), and second input end is connected with the output terminal of oscillator (202) simultaneously.
4, the sniffer that is used for peripheral obstacle for motor vehicle as claimed in claim 1 is characterized in that the first input end of frequency mixer (214) is connected with the output terminal of summing circuit (203), and second input end is connected with the output terminal of summing circuit (204) simultaneously.
5, the sniffer that is used for peripheral obstacle for motor vehicle as claimed in claim 1 is characterized in that the first input end of frequency mixer (214) is connected with the output terminal of microwave source (207), and second input end is connected with the output terminal of microwave source (208) simultaneously.
6, the sniffer that is used for peripheral obstacle for motor vehicle as claimed in claim 1 is characterized in that the output terminal of the output terminal of output terminal, frequency mixer (214) in frequency mixer (212) or microwave source (207), (208) is provided with wave filter.
7, the sniffer that is used for peripheral obstacle for motor vehicle as claimed in claim 1, it is characterized in that being provided with power amplifier, to increase emissive power and detection range, in such cases, the output terminal of microwave source (207) is connected with the input end of power amplifier (209), and the output terminal of power amplifier (209) directly is connected with emitting antenna or is connected with the input end of directional coupler (210).
8, the sniffer that is used for peripheral obstacle for motor vehicle as claimed in claim 1, it is characterized in that being provided with frequency control unit (218), the input end of frequency control unit (218) is connected with the output terminal of arithmetic element (217), perhaps the output terminal with frequency measurement unit (216) is connected, the output terminal of frequency control unit (218) is connected with the voltage-controlled voltage input end of oscillator (201) or oscillator (202), with the oscillation frequency of control generator (201) or oscillator (202).
9, as the described sniffer that is used for peripheral obstacle for motor vehicle of claim 1-8, it is characterized in that all circuit pack in the housing, be installed on before and after the automobile in bumper or roof, the car side.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200620019310 CN2881621Y (en) | 2006-02-28 | 2006-02-28 | Detector for obstacle around vehicle |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200620019310 CN2881621Y (en) | 2006-02-28 | 2006-02-28 | Detector for obstacle around vehicle |
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| Publication Number | Publication Date |
|---|---|
| CN2881621Y true CN2881621Y (en) | 2007-03-21 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200620019310 Expired - Fee Related CN2881621Y (en) | 2006-02-28 | 2006-02-28 | Detector for obstacle around vehicle |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102841383A (en) * | 2011-06-21 | 2012-12-26 | 通用电气公司 | Sensor assemblies used to detect proximity of a material to a microwave element |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102841383A (en) * | 2011-06-21 | 2012-12-26 | 通用电气公司 | Sensor assemblies used to detect proximity of a material to a microwave element |
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Granted publication date: 20070321 |