Bayonet camera

Abstract

The invention provides a bayonet camera which comprises a rectifier unit, a synchronous control unit and a sensitization control unit, wherein the rectifier unit is used for generating a power frequency square wave according to an electric supply alternating current; the synchronous control unit is used for generating a synchronous control signal in a power frequency square wave period needing to generate the synchronous control signal, wherein the rising edge of the synchronous control signal is less than the rising edge in the power frequency square wave period by one preset time difference; and the sensitization control unit is used for generating a sensitization device time sequence control signal according to the synchronous control signal output by the synchronous control unit and outputting the sensitization device time sequence control signal to a sensitization device. Compared with the prior art, the bayonet camera has the advantages that a phaselocked loop frequency multiplier circuit is avoided, possible synchronization of a power frequency alternating current time domain and a bayonet direct current clock domain is realized inside an FPGA (Field Programmable Gate Array), a veneer circuit is simple in design; the step length is more accurately regulated in an exposure time point and has the order of magnitude of reaching an ns level.

Description

technical field [0001] The invention relates to security technology, in particular to a bayonet camera capable of simple and efficient power frequency synchronization. Background technique [0002] Traffic checkpoints usually use advanced photoelectric, computer, image processing, pattern recognition, remote data access and other technologies to monitor the motor vehicle lanes and non-motor vehicle lanes of the monitored road section in real time around the clock and record relevant image data. The front-end processing system analyzes the captured images, and automatically obtains the passing time, location, driving direction, license plate number, license plate color, body color and other data of the vehicle. And the acquired information is transmitted to the database of the bayonet system control center through the computer network for data storage, query, comparison and other processing. When a hit-and-run, violation or suspicious vehicle is found, the system will automat...

AI Technical Summary

Problems solved by technology

[0007] 1) 100Hz is used as the input of the phase-locked loop, and the analog scheme is usually considered, so an additional analog phase-locked loop circuit needs to be added on the circuit board, which will increase the complexity and cost of the circuit board accordingly

Even if a digital PLL solution is available (digital solutions are often hard to find), it is still an additional overhead on hardware resources

[0008] 2) After the phase-locked loop multiplies the power frequency square wave by 360 times, the exposure time point adjustment step value accounts for 1 / 360 of the entire traffic light energy cycle, and the order of magnitude in time is us level (1 / 360×10ms). The multiplier of the ring is usually limited to a certain extent, so the change of the exposure time point adjustment step value is limited to a certain extent

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