CN204405840U - A kind of high precision distance detector of double channel data acquisition - Google Patents

Abstract

The utility model discloses a high-precision rangefinder for dual-channel data collection, which is characterized in that it includes a microprocessor, a first low-pass filter and a second low-pass filter connected thereto, the microprocessor and a PLL lock Phase circuit connection, PLL phase-locked circuit includes local oscillator signal output terminal and main oscillator signal output terminal, PLL phase-locked circuit local oscillator signal is output to the laser emitting circuit after modulation, and the other is output to the electric mixing circuit, PLL phase-locked One of the output ends of the main vibration signal of the circuit is modulated and output to the diode receiving circuit, and the other is also output to the electric mixing circuit. The electric mixing circuit is connected to the first low-pass filter, and the diode receiving circuit is connected to the transimpedance amplifier. The amplifier is connected with a second low pass filter. The rangefinder of the utility model adopts a dual-channel data acquisition structure, and the local oscillator signal, the main oscillator signal and the echo signal of the rangefinder cancel out the inherent error signal during frequency mixing, which greatly improves the measurement accuracy.

Description

A high-precision rangefinder with dual-channel data acquisition

technical field

The utility model relates to a laser rangefinder, in particular to a high-precision rangefinder for dual-channel data collection.

Background technique

Laser rangefinders are widely used in construction, interior decoration and other fields due to their high measurement accuracy and ease of use. Most general laser ranging devices use avalanche photodiodes as receiving components for receiving reflected beams. Due to its inherent electrical characteristics, avalanche photodiodes will produce changes in electrical parameters, such as changes in multiplication factor and phase, when external conditions change, such as changes in temperature and light intensity, resulting in a decrease in measurement accuracy. At the same time, other reasons such as circuit aging will also cause the reduction of measurement accuracy. For this reason, corresponding measures have been developed at home and abroad to reduce this measurement error. The traditional method is to add a calibration device. One is to use a reflector to reflect a part of the emitted light through a fixed distance inside the machine and then reflect it to another set of avalanche photodiode receiving system. After comparing the measured data with the fixed distance, a correction parameter is generated. Then use this parameter to correct the measurement data of the measured distance, so as to improve the measurement accuracy. The other is to modulate the error signal generated by the avalanche photodiode and the circuit, and emit it together with the laser. After being received by the avalanche photodiode, it will cancel out the inherent error signal during frequency mixing, thereby improving the accuracy.

Utility model content

The technical problem to be solved by the utility model is to provide a high-precision rangefinder for dual-channel data acquisition in view of the above-mentioned deficiencies in the prior art. The rangefinder of the utility model adopts a dual-channel data acquisition structure. The local oscillator signal and the main oscillator signal generated by the PLL phase-locked circuit cancel out the inherent error signal during frequency mixing, thereby improving the accuracy. After the echo signal is optically mixed in the diode receiving circuit, it passes through the transimpedance amplifier, and the low-pass filter obtains the measurement difference frequency signal and inputs it to the microprocessor. The measurement data is corrected by the correction parameters, which further improves the measurement accuracy.

In order to solve the above technical problems, the technical solution adopted by the utility model is: a high-precision rangefinder for dual-channel data acquisition, which is characterized in that it includes a microprocessor and a first low-level sensor connected to the input end of the microprocessor. Pass filter, the second low-pass filter, the output end of the microprocessor is connected with the PLL phase-lock circuit, the output end of the PLL phase-lock circuit includes a local oscillator signal output end and a main oscillator signal output end, and the PLL lock One of the local oscillator signal output terminals of the phase circuit is modulated and then output to the laser transmitting circuit, and the other is output to the electric mixing circuit. Output to the electric frequency mixing circuit, the output end of the electric frequency mixing circuit is connected with the first low-pass filter, the output end of the diode receiving circuit is connected with the transimpedance amplifier, and the output end of the transimpedance amplifier is connected with the second low-pass filter device connection.

The above-mentioned high-precision rangefinder for dual-channel data acquisition is characterized in that: the microprocessor contains two A/D sampling cores.

The above-mentioned high-precision rangefinder for dual-channel data acquisition is characterized in that: the PLL phase-locked circuit is a circuit based on the CDCE925 chip.

The above-mentioned high-precision rangefinder for dual-channel data acquisition is characterized in that: the electric mixing circuit includes a triode Q1, the base of the triode Q1 is connected to one end of the resistor R2 and one end of the resistor R7, and the other end of the resistor R2 Grounded, the other end of the resistor R7 is the input end of the local oscillator signal, the emitter of the triode Q1 is connected to one end of the resistor R1 and one end of R6, the other end of the resistor R1 is grounded, and the other end of the resistor R6 is the input end of the oscillator signal The collector of the triode Q1 is connected to a 5V power supply through a resistor R4, the collector of the triode Q1 is also connected to the inverting terminal of the operational amplifier U2B through a series connected capacitor C5 and resistor R3, and the non-inverting terminal of the operational amplifier U2B is connected to the resistors R11 and C9. A low-pass filter circuit is connected, and a capacitor C7 and a resistor R9 are connected in parallel between the inverting terminal and the output terminal of the operational amplifier U2B, and the output terminal of the operational amplifier U2B is connected to the first A/D module of the microprocessor. the

The above-mentioned high-precision rangefinder for dual-channel data acquisition is characterized in that: the laser emitting circuit includes a triode Q3, the collector of the triode Q3 is connected to one end of the inductor L6, and the base of the triode Q3 is connected to one end of the resistor R58 The emitter of the triode Q3 is connected to one end of the resistor R59, the other end of the inductor L6 is connected to the negative electrode of the light-emitting diode LD1 and is the input end of the local oscillator signal, and the other end of the resistor R58 is connected to the output end of the operational amplifier U3. A capacitor C55 is connected between the inverting end of the operational amplifier U3 and the output end, the same-phase end of the operational amplifier U3 is connected to the power supply through a resistor R54, and the same-phase end of the operational amplifier U3 is also connected to the collector of the transistor Q2 and one end of the resistor R56. The other end of the resistor R56 and the emitter of the transistor Q2 are grounded, and the base of the transistor Q2 is connected to the resistor R49.

The above-mentioned high-precision rangefinder for dual-channel data acquisition is characterized in that: the diode receiving circuit includes an avalanche diode D1 and a resistor R1 connected to D1, and the other end of the resistor R1 is connected to the inverting end of the operational amplifier U1A connection, parallel resistors R6 and C1 between the inverting terminal and the output terminal of the operational amplifier U1A, the non-inverting terminal of the operational amplifier U1A is connected to a transimpedance amplifier, and the transimpedance amplifier includes a resistor R2 connected to a 5V power supply, and The other end of the resistor R2 is connected to the parallel resistor R12 and the capacitor C8, the output terminal of the operational amplifier U1A is connected to the parallel resistor R5 and the capacitor C10 through the resistor R4, and the output terminal of the operational amplifier U1A is also connected through the serial resistor R3, C5 are connected with the inverting terminal of the operational amplifier U2B, and the parallel connection resistor R9 and capacitor C7 are connected between the inverting terminal and the output terminal of the operational amplifier U2B, and the output terminal of the operational amplifier U2B is connected with the second A/D module connection.

Compared with the prior art, the utility model has the following advantages:

The rangefinder of the utility model adopts a dual-channel data acquisition structure, and the local oscillator signal and the main oscillator signal generated by the PLL phase-locked circuit of the rangefinder cancel out the inherent error signal during frequency mixing, thereby improving the accuracy. After the echo signal is optically mixed in the diode receiving circuit, it passes through the transimpedance amplifier, and the low-pass filter obtains the measurement difference frequency signal and inputs it to the microprocessor. The measurement data is corrected by the correction parameters, which further improves the measurement accuracy.

The technical solutions of the present utility model will be further described in detail through the drawings and embodiments below.

Description of drawings

Fig. 1 is a structural block diagram of a dual-channel data acquisition rangefinder of the present invention;

Fig. 2 is the schematic diagram of the PLL phase-locked circuit of the present utility model;

Fig. 3 is the schematic diagram of the electrical mixing circuit of the present utility model;

Fig. 4 is the schematic diagram of the laser emitting circuit of the present utility model;

Fig. 5 is a schematic diagram of the diode receiving circuit of the present invention.

Detailed ways

As shown in Figure 1, a kind of high-precision range finder of two-channel data acquisition is characterized in that: comprise microprocessor 1 and the first low-pass filter 2 that is connected with described microprocessor 1 input end, the second Low-pass filter 3, the output end of the microprocessor 1 is connected with the PLL phase-locking circuit 4, the output end of the PLL phase-locking circuit 4 includes a local oscillator signal output end and a main oscillation signal output end, and the PLL phase-locking circuit 4. One output terminal of the local oscillator signal is modulated and output to the laser emitting circuit 7, and the other output terminal is output to the electric mixing circuit 5. The main oscillator signal output terminal of the PLL phase-locked circuit 4 is modulated and output to the diode receiving circuit 8. The other road is also output to the electric frequency mixing circuit 5, the output end of the electric frequency mixing circuit 5 is connected with the first low-pass filter 2, and the output end of the diode receiving circuit 8 is connected with the transimpedance amplifier 6, and the transimpedance amplifier 6. The output terminal is connected with the second low-pass filter 3.

The microprocessor 1 contains two A/D sampling cores.

As shown in FIG. 2 , the PLL phase-locking circuit 4 is a circuit based on a CDCE925 chip.

As shown in Figure 3, the electrical mixing circuit 5 includes a triode Q1, the base of the triode Q1 is connected to one end of the resistor R2 and one end of the resistor R7, the other end of the resistor R2 is grounded, and the other end of the resistor R7 is a local oscillator signal The input terminal, the emitter of the triode Q1 is connected to one end of the resistor R1 and one end of the resistor R6, the other end of the resistor R1 is grounded, the other end of the resistor R6 is an input terminal of the vibration signal, and the collector of the triode Q1 is connected to 5V through the resistor R4 power supply, the collector of the triode Q1 is also connected to the inverting terminal of the operational amplifier U2B through the capacitor C5 and the resistor R3 connected in series, and the non-inverting terminal of the operational amplifier U2B is connected to the low-pass filter circuit composed of the resistors R11 and C9, and the operational amplifier U2B is inverting A capacitor C7 and a resistor R9 are also connected in parallel between the phase terminal and the output terminal, and the output terminal of the operational amplifier U2B is connected to the first A/D module of the microprocessor 1 . the

As shown in Figure 4, the laser emitting circuit 7 includes a triode Q3, the collector of the triode Q3 is connected to one end of the inductor L6, the base of the triode Q3 is connected to one end of the resistor R58, and the emitter of the triode Q3 is connected to one end of the resistor R59. connected, the other end of the inductor L6 is connected to the negative pole of the light-emitting diode LD1 and is the input end of the local oscillator signal, the other end of the resistor R58 is connected to the output end of the operational amplifier U3, and the inverting end and the output end of the operational amplifier U3 are connected Connect the capacitor C55, the non-inverting terminal of the operational amplifier U3 is connected to the power supply through the resistor R54, the non-inverting terminal of the operational amplifier U3 is also connected to the collector of the triode Q2 and one end of the resistor R56, and the other end of the resistor R56 and the emitter of the triode Q2 are grounded. The base of the transistor Q2 is connected to the resistor R49.

As shown in Figure 5, the diode receiving circuit 8 includes an avalanche diode D1 and a resistor R1 connected to D1, the other end of the resistor R1 is connected to the inverting terminal of the operational amplifier U1A, and the inverting terminal of the operational amplifier U1A is connected to the inverting terminal of the operational amplifier U1A Resistors R6 and C1 are connected in parallel between the output terminals, and the non-inverting terminal of the operational amplifier U1A is connected to a transimpedance amplifier 6, which includes a resistor R2 connected to a 5V power supply, and a resistor R2 connected in parallel with the other end of the resistor R2 R12 and capacitor C8, the output terminal of the operational amplifier U1A is connected with the resistor R5 and the capacitor C10 connected in parallel through the resistor R4, the output terminal of the operational amplifier U1A is also connected with the inverting phase of the operational amplifier U2B through the resistors R3 and C5 connected in series The parallel connection resistor R9 and capacitor C7 are connected between the inverting terminal and the output terminal of the operational amplifier U2B, and the output terminal of the operational amplifier U2B is connected to the second A/D module of the microprocessor 1 .

In this embodiment, the microprocessor includes two A/D sampling cores, which can simultaneously sample two channels of difference frequency signals. The microprocessor plays the role of phase discrimination at the same time, and can compare the two signals and calculate the distance value. The PLL phase-locked circuit can output the local oscillator signal and the main oscillator signal with a fixed frequency difference through the control of the microprocessor. One of the local oscillator signals is modulated and output to the laser emission, and the other is output to the electric mixing circuit. One of the main oscillator signals is modulated and then output to the avalanche photodiode, and the other is also output to the electric frequency mixing circuit, which mixes the local oscillator signal and the main oscillator signal to obtain a reference difference frequency signal. The electric frequency mixing circuit mixes the signals and outputs the reference difference frequency signal of the local oscillator signal and the main oscillator signal through the first low-pass filter circuit and inputs it to the A/D sampling port of the microprocessor. After the echo signal is optically mixed in the diode receiving circuit, it is mixed with the main vibration signal to obtain the measurement difference frequency signal, and the current signal is converted into a voltage signal through the transimpedance amplifier, and the second low-pass filter is used to obtain the measurement difference frequency signal output. into another A/D sampling port of the microprocessor. The local oscillator signal and the main oscillator signal generated by the PLL phase-locked circuit of the range finder cancel out the inherent error signal during frequency mixing, thereby improving the accuracy. After the echo signal is optically mixed in the diode receiving circuit, it passes through the transimpedance amplifier, and the low-pass filter obtains the measurement difference frequency signal and inputs it to the microprocessor. The measurement data is corrected by the correction parameters, which further improves the measurement accuracy.

The above are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any simple modifications, changes and equivalent structural changes made to the above embodiments according to the technical essence of the present utility model still belong to Within the scope of protection of the technical solution of the utility model.

Claims (6)

1. the high precision distance detector of a double channel data acquisition, it is characterized in that: the first low-pass filter (2) comprising microprocessor (1) and be connected with described microprocessor (1) input end, second low-pass filter (3), described microprocessor (1) output terminal is connected with PLL phase lock circuitry (4), described PLL phase lock circuitry (4) output terminal comprises local oscillation signal output terminal and the main signal output part that shakes, laser transmission circuit (7) is exported in described PLL phase lock circuitry (4) local oscillation signal output terminal one tunnel after modulation, electric mixting circuit (5) is exported on another road, diode receiving circuit (8) is exported in main signal output part one tunnel that shakes of described PLL phase lock circuitry (4) after modulation, electric mixting circuit (5) is also exported on another road, described electric mixting circuit (5) output terminal is connected with the first low-pass filter (2), described diode receiving circuit (8) output terminal is connected with trans-impedance amplifier (6), described trans-impedance amplifier (6) output terminal is connected with the second low-pass filter (3).

2. according to the high precision distance detector of a kind of double channel data acquisition according to claim 1, it is characterized in that: described microprocessor (1) includes 2 A/D sampling kernels.

3. according to the high precision distance detector of a kind of double channel data acquisition according to claim 1, it is characterized in that: described PLL phase lock circuitry (4) is the circuit based on CDCE925 chip.

4. according to the high precision distance detector of a kind of double channel data acquisition according to claim 1, it is characterized in that: described electric mixting circuit (5) comprises triode Q1, described triode Q1 base stage and resistance R2 one end, R7 one end connects, described resistance R2 other end ground connection, the described resistance R7 other end is local oscillation signal input end, described triode Q1 emitter-base bandgap grading and resistance R1 one end, R6 one end connects, described resistance R1 other end ground connection, the described resistance R6 other end is the main signal input part that shakes, described triode Q1 collector connects 5V power supply by resistance R4, described triode Q1 collector is also by the electric capacity C5 of series connection, resistance R3 is connected with operational amplifier U2B end of oppisite phase, operational amplifier U2B in-phase end and resistance R11, the low-pass filter circuit of C9 composition connects, electric capacity C7 and resistance R9 is also parallel with between described operational amplifier U2B end of oppisite phase and output terminal, one A/D model calling of described operational amplifier U2B output terminal and microprocessor (1).

5. according to the high precision distance detector of a kind of double channel data acquisition according to claim 1, it is characterized in that: described laser transmission circuit (7) comprises triode Q3, described triode Q3 collector is connected with inductance L 6 one end, described triode Q3 base stage is connected with resistance R58 one end, described triode Q3 emitter-base bandgap grading is connected with resistance R59 one end, the other end of described inductance L 6 is connected with light emitting diode LD1 negative pole and is local oscillation signal input end, the described resistance R58 other end is connected with operational amplifier U3 output terminal, described operational amplifier U3 end of oppisite phase be connected electric capacity C55 between output terminal, described operational amplifier U3 in-phase end is connected with power supply by resistance R54, described operational amplifier U3 in-phase end also with triode Q2 collector, resistance R56 one end connects, the described resistance R56 other end and triode Q2 emitter grounding, described triode Q2 base stage is connected with resistance R49.

6. according to the high precision distance detector of a kind of double channel data acquisition according to claim 1, it is characterized in that: the resistance R1 that described diode receiving circuit (8) comprises avalanche diode D1 and is connected with D1, the described resistance R1 other end is connected with the end of oppisite phase of operational amplifier U1A, parallel resistance R6 and C1 between the end of oppisite phase of described operational amplifier U1A and output terminal, the in-phase end of described operational amplifier U1A connects trans-impedance amplifier (6), described trans-impedance amplifier (6) comprises the resistance R2 be connected with 5V power supply, the resistance R12 be in parallel be connected with the resistance R2 other end and electric capacity C8, the output terminal of described operational amplifier U1A is connected with the resistance R5 be in parallel and electric capacity C10 by resistance R4, the output terminal of described operational amplifier U1A is also by the resistance R3 of series connection, C5 is connected with the end of oppisite phase of operational amplifier U2B, the end of oppisite phase of described operational amplifier U2B be connected parallel resistance R9 and electric capacity C7 between output terminal, the output terminal of described operational amplifier U2B and the 2nd A/D model calling of microprocessor (1).