Automatic detecting alarm for collision of vehicles
The utility model belongs to a kind of laser detector and common safety detection device of forming of electronic circuit of utilizing, and can be used for preventing the anti-theft alarm of vehicle collision or aspects such as warehouse, door cabinet.
How vehicle, particularly power actuated vehicle prevent to bump against with people, thing in the process of moving, avoid traffic accident, are the major issues that vehicle will solve in making and using.Existing collision prevention of vehicle detection technique adopts ultrasonic fault detection usually, the mode of infrared acquisition and microwave sounding.If adopt main, passive type infrared detection technique, then utilize the infrared radiation (promptly utilizing the heat emission mode) that detects people or object self to realize the passive type infrared acquisition, the device of Shi Xianing in this way, influenced greatly by environment, a little less than the antijamming capability, detection range is short, and then prices are rather stiff as improving.If the active infra-red detecting device that utilizes infrared, principle of reflection to make is subjected to the restriction of infrared tube emissive power, detection range does not satisfy the requirement of self-propelled vehicle stopping distance, and the detectable limit distance can not change with the variation of the speed of a motor vehicle.
The purpose of this utility model is that the employing semiconductor laser that power is big, volume is little, cheap is formed laser emission element as radiated element; Utilize highly sensitive photistor as receiving element, form the receiving element of reflector laser; Adopt optical system, light beam is focused on; And the speed of a motor vehicle is judged, changed detectivity, and then change the detection limit distance.Make to have the stability height by the vehicle automatic collision detecting device of making according to the said technology of the utility model, detect distance, satisfy the desired condition of power actuated vehicle automatic collision.
Collision prevention of vehicle described in the utility model or warning automatic detector are made of feedway, receiving device, signal processing circuit, optical system etc.An oscillating circuit (3) is arranged in feedway, and the input end of signal output part of this oscillating circuit (3) and current amplification circuit (2) links, and the mouth of current amplification circuit (2) and semiconductor laser (1) link; In receiving device, automatically the scanner unit of yaw (a 19) (see figure 4) is arranged, laser pickoff (16) is installed on this scanner unit (19), have the photistor (18) that receives reflected light signal to be placed on the focus of this laser pickoff (16) lens (17) in laser pickoff (16), they constitute receiving optics (5) jointly; The output signal of photistor (18) is delivered to preamplifier (6) input end, this signal is through preamplifier (6), broadband, high speed operation amplifier (7), after emitter-follower (8) amplifies, deliver to shaping circuit (9) shaping, obtain identically, and the signal of certain amplitude is arranged with transmitting frequency, by the decoding circuit (10) of voltage to frequency conversion this frequency signal is decoded at last, obtain a level signal.This level signal can be used as sound, light is reported to the police, or as self-stopping control signal.
In order to realize that detecting distance can change with speed of a motor vehicle variation, the utility model has designed speed of a motor vehicle voltage signal processing circuit (11).This signal processing circuit (11) is the resistance (R by two or more
1, R
2R
i) (i is a natural number) connect in series formation potential-divider network circuit, from vehicle speed detector device, obtain vehicle speed signal V with voltage form
0Deliver to the input end (12) of potential-divider network circuit, and through divider resistance (R
1, R
2R
i) dividing potential drop, obtain V
1, V
2V
j(j is a natural number) individual voltage signal is as the incoming signal of the electronic switching device of being made up of electronic switch (14) (13).Because V
0Size depend on the speed of a motor vehicle, so the different speed of a motor vehicle can obtain different V
1, V
2V
j, thereby the number of switch (14) conducting is also different, with of the input of these on-off signals, with the feedback resistance (R of different resistances as noncontacting switch (15)
' 1, R
' 2R
' j) access band, high speed operation amplifier (7) two ends, thereby change the magnification factor of this amplifier (7), make the sensitivity of this detecting device change with the speed of a motor vehicle, realize that the detectable limit distance changes with the speed of a motor vehicle to change.
Collision prevention of vehicle described in the utility model or warning automatic detector have the following advantages:
1. cheap, the cost of whole device is lower than 200 yuan;
2. detection range is far away, can reach 15~20 meters, and can change its detection range according to stopping distance (speed of a motor vehicle) automatic compensation; When vehicle body was enough wide, one or more than one automatic collision detector were settled in place that can be suitable onboard, to guarantee to cover the hazardous location of vehicle front;
Since technology described in the utility model institute emitted laser wavelength away from visible wavelength, and receiving device only detects this emission wavelength, frequency, differentiates, thus the advantage of good in anti-interference performance is arranged, but all-weather service;
4. this detector applies scope is wider, not only can be used for can also being used for warning, the demonstration of other occasion outside the automatic detection of collision prevention of vehicle, for example is used in the warning in warehouse, antitheft detection alarm or the like aspect.
Fig. 1: automatic collision, Alarm Detector schematic diagram;
Fig. 2: cellular laser pickoff,
(a) cutaway view, (b) end elevation;
Fig. 3: tubular laser pickoff;
Fig. 4: yaw scans the receiving device scheme drawing automatically;
(a) state a, (b) state b.
Further specify principle of work of the present utility model and structure thereof below in conjunction with drawings and Examples.
In collision prevention of vehicle described in the utility model or the warning automatic detector, have an oscillating circuit (3) to produce an output signal in its feedway, this signal is a fixed frequency, and the isoparametric signal of certain pulsewidth, dutycycle and amplitude is arranged, (for example, producing frequency is 1KH
Z, pulsewidth is 0.4 μ s, dutycycle is 0.2%, amplitude is the square wave of 9V); This output signal is delivered to current amplification circuit (2) after electric current amplifies, in order to excite semiconductor laser (1) bright dipping that connects mutually with current amplification circuit (2) mouth, the light beam that laser (1) sends is via the outwards emission of optical system collimation back, when light beam is run into the place ahead obstacle (4), its folded light beam is received optical system (5) and detects, the reflected light signal that is detected, after opto-electronic conversion, produce and the emission light frequency, the small signal that wavelength is identical, after this signal delivered to preamplifier (6), through the broadband, after high speed operation amplifier (7) amplifies, again the output signal of op amp (7) is delivered to shaping circuit (9) shaping by emitter-follower (8), obtain identical subsequently with transmitting frequency, and the signal of certain amplitude arranged, by the decoding circuit (10) of voltage to frequency conversion this frequency signal is decoded at last, obtain a level signal.This level signal can be used as sound, light is reported to the police, or as self-stopping control signal.
The said receiving optics of the utility model (5) is a scanner unit of yaw (19) automatically, on the scanner unit (19) of this automatic yaw laser pickoff (16) is installed, and laser pickoff (16) can be made the different shaped shape.For example, its front end can be spherical shape or approximate many faceted pebbles of sphere type shape (as shown in Figure 2) or tubular (as shown in Figure 3), and one or more than one lens (17) are arranged, its lens (17) can become cellular distribution, also can arrange by fore-and-aft direction to place on the laser pickoff (16); On the focus of each lens or set of lenses, be mounted with the photistor (18) that it receives the reception reflected light signal that wavelength and emission optical maser wavelength is complementary, after photistor (18) receives reflected light signal,, signal is delivered to preamplifier (6) through opto-electronic conversion.
In order to make laser pickoff can in a big way, detect reflected light beam signal, the automatic yaw scanning receiving device (19) of laser pickoff (16) is installed can be realized the yaw action by eccentric wheel (20), make detection range form a fan-shaped territory.
The principle of employed speed of a motor vehicle voltage signal processing circuit (11) constitutes as previously described in the utility model, repeats no more herein.