Laser range finder with self-checking function

Abstract

A laser range finder with a self-checking function comprises a shell, a storage battery, a laser emitting head and a main control circuit board, and the main control circuit board comprises an emitting and receiving module, a photoelectric detector module, a display module, a detection mechanism, a control circuit and a prompt circuit. The transmitting and receiving module comprises a trigger signal source unit; the storage battery, the laser emission head, the main control circuit board, the detection mechanism, the control circuit and the prompt circuit are arranged in the shell; the detection mechanism comprises sliding grooves, a sliding shell and a photoelectric triode, sliding plates are arranged on the front side and the rear side of the rear end of the sliding shell respectively, the two sliding grooves are formed in the front outer side end of the shell, and the two sliding plates of the sliding shell are located in the two sliding grooves respectively; the photoelectric triode is installed in the front end of the sliding shell. According to the invention, the interference signal entering the gain signal can be effectively processed, and the distance measurement effect is ensured; the working performance of the laser emission head can be detected, and when the power of the laser emission head is reduced to a threshold value, an alarm can be given to prompt a worker to carry out maintenance.

Description

Technical Field

[0001] The invention relates to the technical field of measuring equipment, in particular to a laser rangefinder with a self-checking function. Background Art

[0002] Laser rangefinder is an instrument that uses a certain parameter of modulated laser to measure the distance to the target. According to the distance measurement method, it is divided into phase method rangefinder and pulse method rangefinder. The pulse laser rangefinder emits a beam or a series of short pulse laser beams to the target during operation. The laser beam reflected by the target is received by the photoelectric element. The timer measures the time from the emission to the reception of the laser beam and calculates the distance from the observer to the target. The phase method laser rangefinder detects the distance by detecting the phase difference between the emitted light and the reflected light when propagating in space. The laser rangefinder is light in weight, small in size, simple to operate, fast and accurate. Its error is only one-fifth to several hundredths of other optical rangefinders, and has been effectively used in the field of measurement.

[0003] Although the existing laser rangefinder meets the measurement needs to a certain extent, it is limited by the structure and has some technical shortcomings that need to be improved. First, after the internal APD laser receiving circuit module receives the echo light signal and converts it into an electrical signal, the laser pulse echo signal is amplified by the pre-amplifier circuit. Before entering the multi-channel moment identification circuit module, the interference signal after the signal gain is not effectively processed, which will more or less have an adverse effect on the final distance measurement effect. Second, the laser transmitter head of the laser rangefinder is one of the important components. When its own quality is poor or it has been used for a long time or frequently used, the transmission power of the laser transmitter head will be more or less attenuated, and there is a probability that the distance between the measuring point and the object will be wrong; in the prior art, usually, after a period of time, the technician disassembles the shell of the laser rangefinder to detect the performance of the laser transmitter head. The above detection mode requires experienced technicians to use professional instruments to achieve, so the detection is inconvenient and relatively costly (if the operation is improper, it may also cause damage to the transmitter head and other components). Summary of the invention

[0004] In order to overcome the drawbacks of the existing laser rangefinders as described in the background technology due to structural limitations, the present invention provides a laser rangefinder with a self-checking function, which can effectively process the interference signal in the gain signal entering the multi-channel moment identification circuit module under the joint action of relevant mechanisms, and the measurement personnel can detect the working performance of the laser transmitter head at any time period without disassembling the machine. When the power of the laser transmitter head drops to a threshold, the staff can be prompted to perform maintenance in time, thereby ensuring the ranging effect as much as possible.

[0005] The technical solution adopted by the present invention to solve its technical problem is:

[0006] A laser rangefinder with a self-checking function comprises a housing, a storage battery, a laser transmitting head, and a main control circuit board. The main control circuit board comprises a transmitting and receiving module, a photoelectric detector module, and a display module. The laser transmitting head and the main control circuit board are electrically connected. The laser rangefinder is characterized in that it also comprises a detection mechanism, a control circuit, and a prompt circuit. The transmitting and receiving module comprises a trigger signal source unit, a local oscillator optical path modulation drive unit, a signal optical path modulator drive unit, a local oscillator optical path modulation unit, a drive unit, an acousto-optic modulator, an optical amplifier unit, a circulator unit, an array encoding unit, and a beam combiner unit. The photoelectric detector module comprises an APD laser receiving unit, a pre-amplifier unit, a voltage-controlled gain amplifier unit, a collection unit, and a voltage-controlled gain amplifier unit. The display module comprises a denoising suppression unit, a multi-channel time The invention comprises a laser identification unit, a numerical control threshold control unit, a flight time measurement unit, a bus reading unit, a dynamic multi-threshold error correction unit, an APD array unit, a data processing imaging unit, and a data calculation output unit; the battery, the laser transmitter head, the main control circuit board, the detection mechanism, the control circuit, and the prompt circuit are installed in the shell; the detection mechanism includes a slide groove, a sliding shell, and a photoelectric transistor, the rear side end of the sliding shell is an open structure and the front and rear sides are respectively provided with sliding plates, the two slide grooves are installed at the front outer side end of the shell, and the two sliding plates of the sliding shell are respectively located in the two slide grooves; the photoelectric transistor is installed in the front end of the sliding shell; the signal output end of the control circuit is electrically connected to the signal input end of the prompt circuit, and the signal output end of the photoelectric transistor is electrically connected to the signal input end of the control circuit.

[0007] Furthermore, the sliding shell is made of a non-transparent material, and the light-receiving surface of the phototransistor is located at the rear side.

[0008] Furthermore, limit plates are respectively installed on both side ends of the two slide grooves.

[0009] Furthermore, when the sliding shell slides to the middle along the two sliding grooves, the light receiving surface of the phototransistor and the laser emitting head are in a straight line front and back.

[0010] Furthermore, the control circuit includes an adjustable resistor, a phototransistor, and a resistor connected via circuit board wiring, and one end of the first adjustable resistor is connected to one end of the first resistor.

[0011] Furthermore, the prompt circuit includes an adjustable resistor, a resistor, an operational amplifier, an alarm, and a transistor connected via circuit board wiring, one end of the adjustable resistor is connected to the positive power input terminal of the operational amplifier and the positive power input terminal of the alarm, the other end of the adjustable resistor is connected to one end of the resistor and the in-phase input terminal of the operational amplifier, the output end of the operational amplifier is connected to one end of the second resistor, the other end of the second resistor is connected to the base of the transistor, the collector of the transistor is connected to the negative power input terminal of the alarm, and the negative power input terminal of the operational amplifier is connected to the emitter of the transistor.

[0012] Compared with the prior art, the present invention has the following advantages: (1) under the joint action of relevant mechanisms, the present invention can effectively process the interference signal in the gain signal entering the multi-channel time identification circuit module, thereby ensuring the ranging effect; (2) the measurement personnel can slide the sliding shell to the front side end of the laser transmitter head at any time period without disassembling the machine, and can detect the working performance of the laser transmitter head. When the power of the laser transmitter head drops to a threshold value, the alarm can be used to promptly prompt the staff to perform maintenance, so that the equipment as a whole can work stably and reliably. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0014] Figure 1 It is a schematic diagram of the structure of the present invention.

[0015] Figure 2 It is a partial structural schematic diagram of the present invention.

[0016] Figure 3 It is a circuit diagram of the present invention. DETAILED DESCRIPTION

[0017] Figure 1 , 2As shown in , 3, a laser rangefinder with a self-checking function comprises a housing 1, a battery G1, a charging socket CZ1, a laser transmitter F, and a main control circuit board W1. The main control circuit board comprises a transmitting and receiving module, a photoelectric detector module, a display module, and a photoelectric detector. The power input end of the laser transmitter F and the main control circuit board W1 are connected via a wire, and also have a detection mechanism and a control circuit 2, and a prompt circuit 3; the transmitting and receiving module comprises a trigger signal source unit, a local oscillator optical path modulation drive unit, a signal optical path modulator drive unit, a local oscillator optical path modulation unit, a drive unit, an acousto-optic modulator, an optical amplifier unit, a circulator unit, a planar array encoding unit, and a beam combiner unit; the photoelectric detector module comprises an APD laser receiving unit, a pre-amplifier unit, a voltage-controlled gain amplifier unit, a collection unit, and a voltage-controlled gain amplifier unit; the display module comprises a denoising suppression unit, a multi-channel time identification unit, a numerical control threshold control unit, a flight time measurement unit, a bus reading unit, a dynamic multi-threshold error correction unit, an APD array unit, a data processing imaging unit, and a data calculation output unit. The battery G1, the charging socket CZ1, the laser emitting head F, the main control circuit board W1, the control circuit 2, and the prompt circuit 3 are installed in the housing 1. The two poles of the battery G1 and the two poles of the charging socket CZ1, the main control circuit board W1, the power input end of the control circuit, one end of the adjustable resistor RP1 and the other end of the resistor R3, the power input end of the prompt circuit, the positive power input end of the alarm B1, and the emitter of the transistor T1 are connected by wires. The detection mechanism includes a slide 41, a rectangular hollow sliding shell 42, and a photoelectric transistor T. The rear side end of the sliding shell 42 is an open structure and the left and right parts of the rear side end are respectively provided with a sliding plate 421. The two slides 41 are installed at a distance from each other in the middle of the front outer side end of the housing 1. The two sliding plates 421 at the rear side end of the sliding shell are respectively located in the two slides 41; the photoelectric transistor T is installed in the front end of the sliding shell 42.

[0018] Figure 1 , 2As shown in FIG. 3 , the sliding shell 42 is made of a non-transparent material, and the light-receiving surface of the phototransistor T is located at the rear side. A limit plate 411 is welded to the left and right ends of the two slide grooves respectively (to prevent the sliding shell from falling out). The two sliding plates 421 of the sliding shell can slide left and right along the two slide grooves 41. When sliding to the middle, the light-receiving surface of the phototransistor T and the front and back of the laser emitting head F are in a straight line. The control circuit includes adjustable resistors RP1 and RP2 and resistor R2 connected by circuit board wiring, and one end of the first adjustable resistor RP2 is connected to one end of the first resistor R2. The prompt circuit includes an adjustable resistor RP3, resistors R3 and R4, an operational amplifier W2, an alarm B1, and a transistor T1 connected via circuit board wiring. One end of the adjustable resistor RP3 is connected to the positive power input terminal 7 of the operational amplifier W2 and the positive power input terminal of the alarm B1. The other end of the adjustable resistor RP3 is connected to one end of the resistor R3 and the in-phase input terminal 3 of the operational amplifier W2. The output terminal 6 of the operational amplifier W2 is connected to one end of the second resistor R4. The other end of the second resistor R4 is connected to the base of the transistor T1. The collector of the transistor T1 is connected to the negative power input terminal of the alarm B1. The negative power input terminal 4 of the operational amplifier W2 is connected to the emitter of the transistor T1. One end of the resistor R2 at the signal output terminal of the control circuit is connected to the inverting input terminal 2 of the operational amplifier W2 at the signal input terminal of the prompt circuit via a wire. The collector and emitter of the phototransistor T are respectively connected to the other end of the adjustable resistor RP1 at the signal input terminal of the control circuit and the other end of the adjustable resistor RP2 via a wire. Figure 3 Among them, the resistance values ​​of adjustable resistors RP1, RP2, and RP3 are 100Ω, 100K, and 100K respectively (adjusted to 47Ω, 27K, and 79K respectively); the resistance values ​​of resistors R2, R3, and R4 are 67K, 41K, and 10K respectively; the transistor T1 is an NPN transistor of model 9013; the alarm B1 is an active continuous sound buzzer alarm of model FR12V; the operational amplifier W2 is UA741; and the phototransistor T is 3DU33.

[0019] Figure 1 , 2As shown in Figure 3, after the power input end of the main control circuit board W1 is turned on, it is powered on and works, and the trigger signal source unit generates a pulse sequence to drive the trigger signal source to transmit the first and second trigger signals respectively. The first trigger signal and the second trigger signal are frequency modulated by the local oscillator optical path modulation driving unit and the signal optical path modulator driving unit respectively. The local oscillator optical path modulation unit receives the first trigger signal and generates a periodic linear frequency modulated optical signal; at the signal optical branch end, the driving unit controlled by the second trigger signal drives the acousto-optic modulator unit to modulate the signal light; then, after being encoded by the optical amplifier unit, the circulator unit and the array encoding unit, the high-power pulse laser is emitted from the lens of the laser transmitter head, and the echo optical signal irradiated on the object to be measured enters the beam combiner unit by the circulator unit after the wavefront distortion is corrected by the adaptive optical system, and is combined with the local oscillator light. After the photodetector responds to the combined light beam, it is converted into an electrical signal by the APD laser receiving unit; the laser pulse echo signal is first amplified by the pre-amplifier unit, and then enters the voltage-controlled gain amplifier unit. The main control circuit collects the pulse peak value through the pulse peak holding circuit through the acquisition unit, and sets the DAC output voltage according to the peak value to output it to the voltage-controlled gain amplifier unit. The DAC voltage controls the gain of the voltage-controlled gain amplifier unit to achieve the purpose of automatic gain control. After the signal is automatically amplified by the gain, the echo signal is denoised by the denoising suppression unit to suppress the interference noise, and the processed pulse signal is output; the multi-channel time identification unit uses a high-speed comparator to perform multi-channel time identification on the pulse signal under different thresholds, wherein the threshold voltage is controlled by the numerical control threshold control unit; the identified multi-channel time pulses are measured by the flight time measurement unit to obtain multiple flight times, and finally the MCU main control circuit reads the multi-threshold flight time data through its own SPI bus reading unit; the MCU main control adopts a dynamic multi-threshold error correction method through the dynamic multi-threshold error correction unit to correct the pulse leading edge time identification error and then project it onto the APD array unit, the data processing imaging unit collects and images the target information obtained by the APD array unit, and calculates the distance to the measurement target according to the flight time through the data calculation output unit, and outputs the distance measurement data through the serial port (and displays the distance of the measured object through the display screen of the main control circuit board). Through the above technical scheme, compared with the prior art in the field, the present invention improves the waveform of the modulation signal, uses a dynamic multi-threshold error correction algorithm to correct the leading edge moment identification error, and completes the denoising of the laser radar echo signal based on wavelet transform, and uses a dual fuzzy adaptive PID control algorithm to suppress wavefront distortion. In order to achieve a longer ranging capability, the echo signal processing correlation is added, and the functions of automatic gain control and autocorrelation detection are realized, thereby achieving the purpose of combining ranging and imaging functions.

[0020] Figure 1 , 2As shown in FIG. 3 , when the staff needs to test the performance of the laser emitting head F, the two sliding plates 421 of the sliding shell slide along the two sliding grooves 41. When sliding to the middle, the light receiving surface of the phototransistor T and the front and back of the laser emitting head F are in a straight line (and the power switch S2 is turned on). The light beam emitted by the laser transmitter F directly irradiates the light receiving surface of the phototransistor T. When the laser transmitter F works normally, the light irradiating the light receiving surface of the phototransistor T is relatively strong (the conduction degree of the phototransistor T is relatively large and the voltage division is small). The power output by the battery G1 passes through the adjustable resistor RP1, the phototransistor T (the emitter outputs a high level to the other end of the adjustable resistor RP2), the adjustable resistor RP2 and the resistor R2, and the voltage division is relatively small. In this way, the voltage at the reverse input terminal 2 pin of the operational amplifier W2 (for example, 4.2V) is greater than the voltage at the non-inverting input terminal 3 pin of the operational amplifier W2 after the power output by the battery G1 passes through the adjustable resistor RP3 and the resistor R3. The voltage is divided, and the 6th pin of the operational amplifier W2 outputs a low level, and the alarm B1 does not sound, which means that the performance of the laser transmitter F is intact. When the laser transmitter F is working abnormally, the light irradiated on the light receiving surface of the phototransistor T is relatively weak (the conduction degree of the phototransistor T is relatively small and the voltage division is large). The power output by the battery G1 is relatively large through the adjustable resistor RP1, the phototransistor T (the emitter outputs a high level to the other end of the adjustable resistor RP2), the adjustable resistor RP2 and the resistor R2. In this way, the voltage at the reverse input terminal 2 pin of the operational amplifier W2 is less than the voltage at the non-inverting input terminal 3 pin of the operational amplifier W2 after the power output by the battery G1 is divided by the adjustable resistor RP3 and the resistor R3. The 6th pin of the operational amplifier W2 outputs a high level, and the high level enters the base of the transistor T1 through the resistor R4 for voltage reduction and current limiting. The transistor T1 is turned on and the collector outputs a low level and enters the negative power input terminal of the alarm B1. The alarm B1 is energized and sounds, indicating that the performance of the laser transmitter F is not good, and the technicians can replace it later. Through the above, the present invention can effectively process the interference signal in the gain signal entering the multi-channel time identification circuit module, thereby ensuring the ranging effect; the measurement personnel can slide the sliding shell to the front side end of the laser transmitter head at any time period and without disassembling the machine, and can detect the working performance of the laser transmitter head. When the power of the laser transmitter head drops to a threshold value, the alarm can be used to promptly prompt the staff to perform maintenance, so that the overall equipment can work stably and reliably.

[0021] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claim involved.

[0022] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in the embodiments may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A laser rangefinder with a self-checking function, comprising a housing, a battery, a laser transmitter head, and a main control circuit board, wherein the main control circuit board comprises a transmitting and receiving module, a photoelectric detector module, and a display module, and the laser transmitter head and the main control circuit board are electrically connected, characterized in that: It also has a detection mechanism, a control circuit and a prompt circuit; the transmitting and receiving module includes a trigger signal source unit, a local oscillator optical path modulation driving unit, a signal optical path modulator driving unit, a local oscillator optical path modulation unit, a driving unit, an acousto-optic modulator, an optical amplifier unit, a circulator unit, a planar array encoding unit, and a beam combiner unit; the photoelectric detector module includes an APD laser receiving unit, a pre-amplifier unit, a voltage-controlled gain amplifier unit, a collection unit, and a voltage-controlled gain amplifier unit; the display module includes a denoising suppression unit, a multi-channel time identification unit, a digital control threshold control unit, a flight time measurement unit, a bus reading unit, and a dynamic multi-threshold error correction unit , APD array unit, data processing imaging unit, data calculation output unit; the battery, laser transmitter head, main control circuit board, detection mechanism, control circuit, and prompt circuit are installed in the shell; the detection mechanism includes a slide groove, a sliding shell, and a photoelectric triode. The rear end of the sliding shell is an open structure and the front and rear sides are respectively provided with sliding plates. The two slide grooves are installed at the front outer end of the shell, and the two sliding plates of the sliding shell are respectively located in the two slide grooves; the photoelectric triode is installed in the front end of the sliding shell; the signal output end of the control circuit is electrically connected to the signal input end of the prompt circuit, and the signal output end of the photoelectric triode is electrically connected to the signal input end of the control circuit.

2. A laser rangefinder with a self-checking function according to claim 1, characterized in that: The sliding shell is made of non-transparent material, and the light-receiving surface of the phototransistor is located at the rear side.

3. A laser rangefinder with a self-checking function according to claim 1, characterized in that: Limiting plates are respectively installed on both side ends of the two slideways.

4. A laser rangefinder with a self-checking function according to claim 1, characterized in that: When the sliding shell slides to the middle along the two sliding grooves, the light receiving surface of the photoelectric triode and the front and back of the laser emitting head are in a straight line.

5. A laser rangefinder with a self-checking function according to claim 1, characterized in that: The control circuit comprises an adjustable resistor, a phototransistor and a resistor which are connected via circuit board wiring. One end of the first adjustable resistor is connected to one end of the first resistor.

6. A laser rangefinder with a self-checking function according to claim 1, characterized in that: The prompt circuit includes an adjustable resistor, a resistor, an operational amplifier, an alarm, and a transistor connected through circuit board wiring. One end of the adjustable resistor is connected to the positive power input end of the operational amplifier and the positive power input end of the alarm. The other end of the adjustable resistor is connected to one end of the resistor and the in-phase input end of the operational amplifier. The output end of the operational amplifier is connected to one end of the second resistor. The other end of the second resistor is connected to the base of the transistor. The collector of the transistor is connected to the negative power input end of the alarm. The negative power input end of the operational amplifier is connected to the emitter of the transistor.

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