CN112688649A - Control circuit and control method for automatic gain of photoelectric detection system - Google Patents
Control circuit and control method for automatic gain of photoelectric detection system Download PDFInfo
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Abstract
The invention provides a control circuit and a control method for automatic gain of a photoelectric detection system, wherein the control circuit comprises: the device comprises a four-quadrant detector, a pre-amplification unit, a variable gain amplification unit, an operational amplifier signal conditioning unit, a threshold comparison circuit unit and a peak holding circuit unit which are connected with the operational amplifier signal conditioning unit, an A/D sampling circuit unit connected with the peak holding circuit unit, and a control unit respectively connected with the A/D sampling circuit unit, the peak holding circuit unit and the threshold comparison circuit unit. The variable gain control signal V can be adjusted in real time by the control unit according to the laser energy detected by the four-quadrant detectorCGThereby adjusting the gain G of the variable gain amplification unit1Therefore, the output signal of the variable gain amplification unit is within a reasonable interval range, the unsaturated reception of the system is realized, and the wide-range dynamic detection of the photoelectric detection system is realized.
Description
Technical Field
The invention relates to the technical field of electronics, in particular to a control circuit and a control method for automatic gain of a photoelectric detection system.
Background
At present, in a laser detection system, a four-quadrant detector is generally used as a detection unit for laser tracking, a laser light source irradiates a target, an emission echo of the target is projected onto a photosensitive surface of the four-quadrant detector through an optical system, and the four-quadrant detector converts an optical signal containing angle information into a current signal.
Commonly used photodetectors include PIN four quadrant detectors and APD four quadrant detectors. However, as the distance between the target and the target changes from far to near, the laser signal intensity detected by the four-quadrant photodetector of the PIN or APD changes from weak to strong, and the received energy changes from small to large. When the energy received by the four-quadrant detector is small, the amplitude of four paths of voltage output by the pre-amplification unit of the detector is too low, and the signal-to-noise ratio of a signal is greatly influenced by noise; when the energy received by the four-quadrant detector is large, the amplitude of four paths of voltage output by the pre-amplification unit of the detector is too high, and the output signal may be saturated. Therefore, in the actual use process, the real-time adjustment and control of the gain of the photoelectric detection system are very important. The technique of realizing gain control by adjusting the bias voltage of the detector in the prior art can only be suitable for the situation that the bias voltage of the detector is not fixed and needs to be adjusted and compensated in real time along with the temperature change, such as an APD detector; for the PIN detector, if the detector bias voltage is adjusted, a relatively small dynamic range can be generally obtained, and an ideal gain control effect cannot be achieved.
Disclosure of Invention
In view of the above situation, the present invention provides a control circuit and a control method for automatic gain of a photodetection system, which can adjust a variable gain control signal V in real time by a control unit according to the laser energy detected by a four-quadrant detectorCGThereby adjusting the gain G of the variable gain amplification unit1Therefore, the output signal of the variable gain amplification unit is within a reasonable interval range, the unsaturated reception of the system is realized, and the wide-range dynamic detection of the photoelectric detection system is realized.
In order to realize the purpose of the invention, the following scheme is adopted:
a control circuit for the automatic gain of a photodetection system, comprising: the device comprises a four-quadrant detector, a pre-amplification unit, a variable gain amplification unit, an operational amplifier signal conditioning unit, a threshold comparison circuit unit, a peak holding circuit unit, an A/D sampling circuit unit and a control unit, wherein the four-quadrant detector, the pre-amplification unit, the variable gain amplification unit and the operational amplifier signal conditioning unit are sequentially connected;
four-quadrant detector and preamplification unit for converting optical signal into voltage signal V0X(X =1,2,3, 4), and then inputted to the variable gain amplification unit;
a variable gain amplifying unit for controlling the gain according to the gain control signal V generated by the control unitCGFor input voltage signal V0X(X =1,2,3, 4), and a voltage signal V is obtained after enlargement or reduction1X(X =1,2,3, 4) as an input of the operational amplifier signal conditioning unit;
an operational amplifier signal conditioning unit for adjusting the voltage signal V1X(X =1,2,3, 4) and obtaining a voltage signal V after amplitude conditioning2X(X =1,2,3, 4) are input to the threshold comparing circuit unit and the peak holding circuit unit, respectively;
a threshold comparison circuit unit for comparing the voltage signal V2X(X =1,2,3, 4) is compared with a threshold signal TH provided by the control unit and a comparison signal CMP is returned to the control unit according to the comparison result;
a peak hold circuit unit for holding the peak of the output signal according to the GATE signal GATE provided by the control unitX(X =1,2,3, 4), converting the voltage signal V2X(X =1,2,3, 4) widening a predetermined width to obtain a voltage signal V3X(X =1,2,3, 4) and outputs to the a/D sampling circuit unit;
an A/D sampling circuit unit for receiving the voltage signal V3X(X =1,2,3, 4), and starts AD sampling according to a control signal CTRL provided by the control unit, and sends the sampling result to the control unit;
a control unit for providing a threshold signal TH to the threshold comparison circuit unit, receiving a comparison signal CMP returned by the threshold comparison circuit unit, and judging whether to start the peak holding circuit and whether to send out a control signal CTRL according to the comparison signal CMP to enable the peak holding circuit to be startedThe A/D sampling circuit unit starts AD sampling; and receiving AD sampling result, and providing gain control signal V according to sum of four sampled voltagesCGAnd adjusting the gain of the variable gain amplifying unit in real time in reaction to the variable gain amplifying unit.
Further, a four-quadrant detector for converting the optical signal into a current signal IX（X=1,2,3,4）；
A pre-amplifier unit including a transimpedance amplifier for use in accordance with formula V0X（X=1,2,3,4）=-R*IX(X =1,2,3, 4) current signal IX(X =1,2,3, 4) into a voltage signal V0X(X =1,2,3, 4), where R is a transimpedance value of the transimpedance amplifier.
Further, the variable gain amplifying unit comprises an integrated operational amplifier chip and a peripheral resistor capacitor, and is used for generating a variable gain according to the formula V1X（X=1,2,3,4）=G1*V0X(X =1,2,3, 4) pairs V0X(X =1,2,3, 4) is as follows G1Making an adjustment to obtain V1X(X =1,2,3, 4), wherein G1Is the gain of the variable gain amplifying unit controlled by the gain control signal V generated by the control unitCG。
Furthermore, the positive input end of the input stage of the integrated operational amplifier chip is connected with one end of a resistor R1, the other end of the resistor R1 is connected with one end of a capacitor C1, the other end of the capacitor C1 is connected with the positive electrode of the output end of the preamplification unit and used for introducing V0X(X =1,2,3, 4), the negative input end of the input stage of the integrated operational amplifier chip is connected with one end of a resistor R2, the other end of the resistor R2 is connected with GND, and the output end of the output stage of the integrated operational amplifier chip is used for outputting V1X(X =1,2,3, 4), the G + end of the output stage of the integrated operational amplifier chip is connected with the control unit to obtain the gain control signal VCGThe G-end of the output stage of the integrated operational amplifier chip is connected with one end of a resistor R3 and one end of a resistor R4, the other end of the resistor R3 is connected with GND, and the other end of the resistor R4 is connected with VCC.
Furthermore, the operational amplifier signal conditioning unit adopts an in-phase amplifying circuit comprising an operational amplifier and is used for amplifying the voltage signal V1X(X =1,2,3, 4) performing constant gain amplification to obtain a non-saturated voltage V of a desired dynamic range2X(X =1,2,3, 4), then there is V2X=G2*V1X(X =1,2,3, 4), wherein G2The gain of the operational amplifier signal conditioning unit is a fixed value.
Further, the gain of the entire system G = G1*G2。
Further, the threshold comparison circuit unit includes a four-way voltage summing circuit for summing the inputted V and a comparator2X(X =1,2,3, 4) to produce Σ V2X(X =1,2,3, 4), the comparator for comparing Σ V2X(X =1,2,3, 4) and the threshold signal TH: if Σ V2X(X =1,2,3, 4) is greater than the threshold signal TH, returning a comparison signal CMP =1 to the control unit; otherwise, returning a comparison signal CMP =0 to the control unit;
the control unit is used for controlling the start of a peak holding function of the peak holding circuit unit and the start of an AD sampling function of the A/D sampling circuit unit when CMP =1 according to the value of the comparison signal CMP.
Further, the control signal CTRL includes an enable signal CS, a start conversion signal CONVST, and a read/write signal RD, and the a/D sampling circuit unit returns the AD sampling result to the control unit through the 12-bit parallel port bus.
Further, the control unit comprises a single chip microcomputer, an FPGA and an operational amplifier; the single chip microcomputer and the FPGA form a whole, are connected with the A/D sampling circuit unit and the peak value holding circuit unit, are connected with the threshold comparison circuit unit through one operational amplifier, and are connected with the variable gain amplification unit through the other operational amplifier;
the singlechip is used for outputting V through the DA functionDA0The threshold comparison circuit unit is connected with the operational amplifier to generate a threshold signal TH with proper voltage and transmit the threshold signal TH to the threshold comparison circuit unit;
the FPGA is used for receiving the CMP comparison signal returned by the threshold comparison circuit unit; when the returned CMP comparison signal is 1, a peak hold circuit GATE signal GATE is generatedX(X =1,2,3, 4) is transmitted to the peak hold circuit unit to cause the peak hold circuit unit to turn on the peak hold function;
the FPGA is used for generating a control signal CTRL and transmitting the control signal CTRL to the A/D sampling circuit unit;
the singlechip is used for receiving an AD sampling result returned by the A/D sampling circuit unit through a 12-bit parallel port;
the singlechip is used for outputting V through the DA functionDA1Connected with the operational amplifier to generate a gain control signal V with proper voltageCGThe signal is transmitted to a variable gain amplification unit to adjust the gain.
A control method of the automatic gain of a photoelectric detection system is realized by a control circuit of the automatic gain of the photoelectric detection system, and comprises the following steps:
converting an optical signal into a voltage signal V by a four-quadrant detector and a pre-amplification unit0X（X=1,2,3,4）；
By a variable gain amplifying unit according to a gain control signal V generated by a control unitCGFor input voltage signal V0X(X =1,2,3, 4), and a voltage signal V is obtained after enlargement or reduction1X（X=1,2,3,4）；
Voltage signal V is adjusted through operational amplifier signal conditioning unit1X(X =1,2,3, 4) and obtaining a voltage signal V after amplitude conditioning2X（X=1,2,3,4）；
Voltage signal V is compared by threshold value comparison circuit unit2X(X =1,2,3, 4) is compared with a threshold signal TH provided by the control unit and a comparison signal CMP is returned to the control unit according to the comparison result;
through a peak hold circuit unit according to a GATE signal GATE provided by a control unitX(X =1,2,3, 4), converting the voltage signal V2X(X =1,2,3, 4) widening a predetermined width to obtain a voltage signal V3X（X=1,2,3,4）；
Receiving a voltage signal V by an A/D sampling circuit unit3X(X =1,2,3, 4), and starts AD sampling according to a control signal CTRL provided by the control unit, and sends the sampling result to the control unit;
providing a threshold signal TH to the threshold comparison circuit unit through the control unit, receiving a comparison signal CMP returned by the threshold comparison circuit unit, and judging whether to start the peak holding circuit and whether to send a control signal CTRL according to the comparison signal CMP so as to enable the A/D sampling circuit unit to start AD sampling; and pass through and controlThe system unit receives the AD sampling result and provides a gain control signal V according to the sum of four sampled voltagesCGAnd adjusting the gain of the variable gain amplifying unit in real time in reaction to the variable gain amplifying unit.
The invention has the beneficial effects that:
the automatic gain control circuit of the scheme is simple and practical, good in stability and high in precision. The feedback circuit formed by the scheme can adjust the variable gain control signal V in real time by the control unit according to the laser energy detected by the four-quadrant detectorCGThereby adjusting the gain G of the variable gain amplification unit1And then the gain G of the whole system is adjusted, the function that the gain G of the system is automatically adjusted according to the strength of the optical signal is realized, the output signal of the variable gain amplification unit is within a reasonable interval range, the unsaturated reception of the system is realized, the wide-range dynamic detection of the photoelectric detection system is realized, and the working performance of the whole system is improved. The scheme can ensure the detection capability of the whole system without adjusting the bias voltage of the detector, and is suitable for various common photoelectric detectors including PIN four-quadrant detectors and APD four-quadrant detectors.
Drawings
The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.
Fig. 1 is a block diagram of an overall structure of a control circuit for an automatic gain of a photodetection system according to an embodiment of the present application.
Fig. 2 is a circuit configuration diagram of a variable gain amplification unit according to an embodiment of the present application.
Fig. 3 is a circuit configuration diagram of a control unit according to an embodiment of the present application.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings.
The embodiment provides a control circuit and a control method for the automatic gain of a photoelectric detection system. Specifically, the control circuitAs shown in fig. 1, the device comprises a four-quadrant detector, a pre-amplifying unit, a variable gain amplifying unit, an operational amplifier signal conditioning unit, a threshold comparing circuit unit, a peak holding circuit unit, an A/D sampling circuit unit, and a gain control signal VCGThe control unit of (1).
In a four-quadrant detector and preamplifier unit, the four-quadrant detector converts an optical signal into a current signal IX(X =1,2,3, 4), the preamplifier adopts the mode of trans-impedance amplification of an operational amplifier, and converts the current signal into a voltage signal V0X(X =1,2,3, 4), i.e. the input of the four-quadrant detector and the pre-amplification unit is an optical signal, the output of which is V0X(X =1,2,3, 4) is an input of the variable gain amplification unit.
The variable gain amplifying unit receives the voltage signal V output by the four-quadrant detector and the pre-amplifying unit0X(X =1,2,3, 4), a gain control signal V generated by the control unitCGAdjusting gain G of variable gain amplification unit in real time1Will V0X(X =1,2,3, 4) is reduced or enlarged reasonably to realize non-saturated reception, and voltage signal V is obtained1X(X =1,2,3, 4), i.e. the input of the variable gain amplification unit is the output V of the four-quadrant detector and the pre-amplification unit0X(X =1,2,3, 4) and a variable gain control signal V generated by the control unitCGIts output V1XAnd (X =1,2,3, 4) is the input of the operational amplifier signal conditioning unit.
The operational amplifier signal conditioning unit adopts an in-phase amplifying circuit comprising an operational amplifier and receives a voltage signal V output by the variable gain amplifying unit1X(X =1,2,3, 4), performing signal constant gain amplification using formula V2X=G2*V1X(X =1,2,3, 4), wherein G2The gain of the operational amplifier signal conditioning unit is a fixed value, so that a voltage signal V with a proper range is obtained2X(X =1,2,3, 4), i.e. the input of the operational amplifier signal conditioning unit is the output V of the variable gain amplification unit1X(X =1,2,3, 4), the output of which is an input of the peak hold circuit unit and the threshold comparison circuit unit.
Peak hold circuit unit receive op amp conditioningVoltage signal V output by unit2X(X =1,2,3, 4) while receiving a GATE signal GATE for turning on the peak hold function given by the control unitX(X =1,2,3, 4), a narrow pulse voltage signal V is acquired2X(X =1,2,3, 4), and the peak value is appropriately broadened, and the broadened voltage peak value signal V is obtained by holding for a certain time3X(X =1,2,3, 4) is sent to the A/D sampling circuit unit, namely the input of the peak holding circuit unit is the output V of the operational amplifier signal conditioning unit2X(X =1,2,3, 4) and an output GATE of the control unitX(X =1,2,3, 4), the output of which is V3X(X =1,2,3, 4) is an input of the a/D sampling circuit unit.
The threshold comparison circuit unit receives the voltage signal V output by the operational amplifier signal conditioning unit2X(X =1,2,3, 4) and a threshold signal TH given by the control unit, constitute a time discriminating circuit, providing an enable signal for the a/D sampling circuit. When four-circuit summation signal sigma V in threshold comparison circuit unit2XWhen the intensity of (X =1,2,3, 4) exceeds the threshold signal TH, the output comparison signal CMP is high or 1, and when the four-circuit summation signal Σ V2X(X =1,2,3, 4) is less than the threshold TH, the output comparison signal CMP is low or 0, i.e. the input of the threshold comparison circuit unit is the output V of the operational amplifier signal conditioning unit2X(X =1,2,3, 4) and an output TH of the control unit, the output CMP of which is one of the inputs of the control unit.
The A/D sampling circuit unit receives the voltage signal V after the peak holding circuit unit expands3X(X =1,2,3, 4), and simultaneously receiving the a/D sampling start signal CONVST, the enable signal CS, and the read-write signal RD from the control unit, and sending the conversion result to the control unit through a 12-bit parallel port, that is, the input of the a/D sampling circuit unit is the output V of the peak hold circuit unit3X(X =1,2,3, 4) and an a/D sampling control signal CTRL (including a start signal CONVST, an enable signal CS, and a read/write signal RD) output by the control unit, the output of which is one of the inputs of the control unit.
The control unit receives the output CMP of the threshold comparison circuit unit, and when CMP is high, the GATE signal GATE of the peak hold circuit unit is appliedX(X =1,2,3, 4) is set to the effective stateStarting the peak value holding function, simultaneously providing an A/D sampling starting signal CONVST, an enabling signal CS and a read-write signal RD to the A/D sampling circuit unit, starting the AD sampling function, obtaining the sampling result of the A/D sampling circuit unit, and providing a gain control signal V according to the sum of four voltage values obtained by samplingCGFeeding back to the variable gain amplifying unit for gain G1Adjusting so as to achieve a dynamic adjustment of the detection capability, i.e. the input of the control unit is the output of the threshold comparison circuit unit CMP, the sampling result DATA of the A/D sampling circuit unitX(X = 0-11), an output TH of which is an input of the threshold comparing unit, GATEX(X =1,2,3, 4) is an input of the peak hold circuit, and CONVST, CS, RD are inputs of the a/D sampling circuit.
In this example, the variable gain amplification unit includes gain-adjustable op-amp and peripheral R, C devices, as shown in fig. 2, with gain G1Controlled by V generated by the control unitCGA signal.
Specifically, the positive input end of the input stage of the integrated operational amplifier chip is connected with one end of a resistor R1, the other end of the resistor R1 is connected with one end of a capacitor C1, the other end of the capacitor C1 is connected with the positive electrode of the output end of the pre-amplification unit and used for introducing V0X(X =1,2,3, 4), the negative input end of the input stage of the integrated operational amplifier chip is connected with one end of a resistor R2, the other end of the resistor R2 is connected with GND, and the output end of the output stage of the integrated operational amplifier chip is used for outputting V1X(X =1,2,3, 4), the G + end of the output stage of the integrated operational amplifier chip is connected with the control unit to obtain the gain control signal VCGThe G-end of the output stage of the integrated operational amplifier chip is connected with one end of a resistor R3 and one end of a resistor R4, the other end of the resistor R3 is connected with GND, and the other end of the resistor R4 is connected with VCC.
Output V of variable gain amplification unit1X(X =1,2,3, 4) is connected to the operational amplifier signal conditioning unit, input V0X(X =1,2,3, 4) is provided by a four quadrant detector and a preamplification unit. The embodiment is realized by the design of an integrated operational amplifier chip and peripheral R, C components, and V output by a four-quadrant detector and a preamplification unit0X(X =1,2,3, 4) is inputted by the positive input terminal + of the variable gain amplifier, the negative input terminal-throughResistance to ground, gain G of1Controlled by chip pins G + and G-, wherein the voltage of G-is VG-，VG-Obtained by voltage division through a resistor R3 and a resistor R4, namely
VG-=VCC*R3/(R3+R4)；
Thus the gain adjustment voltage VG：
VG=VG+－VG-= VG+－VCC*R3/(R3+R4)=VCG－VCC*R3/(R3+R4)；
Wherein VCC, R3, R4 are all constant values, the gain G of the variable gain amplifying unit1Controlled by VG+I.e. the gain G of the variable gain amplification unit1Controlled by V generated by the control unitCGA signal. Gain of the whole system G = G1*G2。
In this example, as shown in fig. 3, the control unit includes a single chip, an FPGA, and an operational amplifier. The singlechip outputs a high-precision low-voltage signal V by utilizing a self-contained DAC moduleDA0，VDA0The circuit is connected with the operational amplifier to obtain a voltage threshold signal TH with proper size to act on the threshold comparison circuit unit, and the threshold comparison circuit unit returns a comparison signal CMP to act on the FPGA in the control unit; when the CMP signal is high, i.e. CMP =1, the FPGA outputs the GATE signal GATEX(X =1,2,3, 4) turning on the peak hold function, and simultaneously outputting an a/D sampling control signal CTRL (including an enable signal CS, a start conversion signal CONVST, and a read/write signal RD) to the a/D sampling circuit unit, turning on the a/D sampling; the single chip microcomputer obtains four-way voltage DATA DATA through a 12-bit parallel port busX(X =0 to 11); the singlechip outputs a high-precision low-voltage signal V by utilizing a self-contained DAC module after waiting for the sum of the four paths of voltages according to a sampling resultDA1，VDA1Connected with the operational amplifier and outputting a voltage value V with proper magnitudeCGActing on the variable gain amplifying unit to adjust the gain G of the variable gain amplifying unit1Therefore, the wide dynamic range of the gain G of the whole system can be adjusted, the detection capability of the whole system can be ensured without adjusting the bias voltage of the detector, and the method is suitable for common photoelectric detectors including PIN four-quadrant detectors and APD four-quadrant detectors.
The foregoing is merely a preferred embodiment of this invention and is not intended to be exhaustive or to limit the invention to the precise form disclosed. It will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention.
Claims (10)
1. A control circuit for automatic gain of a photodetection system, comprising: the device comprises a four-quadrant detector, a pre-amplification unit, a variable gain amplification unit, an operational amplifier signal conditioning unit, a threshold comparison circuit unit, a peak holding circuit unit, an A/D sampling circuit unit and a control unit, wherein the four-quadrant detector, the pre-amplification unit, the variable gain amplification unit and the operational amplifier signal conditioning unit are sequentially connected;
four-quadrant detector and preamplification unit for converting optical signal into voltage signal V0X(X =1,2,3, 4), and then inputted to the variable gain amplification unit;
a variable gain amplifying unit for controlling the gain according to the gain control signal V generated by the control unitCGFor input voltage signal V0X(X =1,2,3, 4), and a voltage signal V is obtained after enlargement or reduction1X(X =1,2,3, 4) as an input of the operational amplifier signal conditioning unit;
an operational amplifier signal conditioning unit for adjusting the voltage signal V1X(X =1,2,3, 4) and obtaining a voltage signal V after amplitude conditioning2X(X =1,2,3, 4) are input to the threshold comparing circuit unit and the peak holding circuit unit, respectively;
a threshold comparison circuit unit for comparing the voltage signal V2X(X =1,2,3, 4) is compared with a threshold signal TH provided by the control unit and a comparison signal CMP is returned to the control unit according to the comparison result;
a peak hold circuit unit for holding the peak of the output signal according to the GATE signal GATE provided by the control unitX(X =1,2,3, 4), converting the voltage signal V2X(X =1,2,3, 4) widening a predetermined width to obtain a voltage signal V3X(X =1,2,3, 4) andoutputting to an A/D sampling circuit unit;
an A/D sampling circuit unit for receiving the voltage signal V3X(X =1,2,3, 4), and starts AD sampling according to a control signal CTRL provided by the control unit, and sends the sampling result to the control unit;
the control unit is used for providing a threshold signal TH for the threshold comparison circuit unit, receiving a comparison signal CMP returned by the threshold comparison circuit unit, and judging whether to start the peak holding circuit and whether to send out a control signal CTRL according to the comparison signal CMP so that the A/D sampling circuit unit starts AD sampling; and receiving AD sampling result, and providing gain control signal V according to sum of four sampled voltagesCGAnd adjusting the gain of the variable gain amplifying unit in real time in reaction to the variable gain amplifying unit.
2. The control circuit for the automatic gain of the photodetection system according to claim 1, characterized in that:
a four-quadrant detector for converting optical signal into current signal IX（X=1,2,3,4）；
A pre-amplifier unit including a transimpedance amplifier for use in accordance with formula V0X（X=1,2,3,4）=-R*IX(X =1,2,3, 4) current signal IX(X =1,2,3, 4) into a voltage signal V0X(X =1,2,3, 4), where R is a transimpedance value of the transimpedance amplifier.
3. The automatic gain control circuit of claim 1, wherein the variable gain amplifier unit comprises an integrated operational amplifier chip and a peripheral resistor capacitor for controlling the automatic gain according to formula V1X（X=1,2,3,4）=G1*V0X(X =1,2,3, 4) pairs V0X(X =1,2,3, 4) is as follows G1Making an adjustment to obtain V1X(X =1,2,3, 4), wherein G1Is the gain of the variable gain amplifying unit controlled by the gain control signal V generated by the control unitCG。
4. The method of claim 3The control circuit of the automatic gain of the photoelectric detection system is characterized in that the positive pole input end of the input stage of the integrated operational amplifier chip is connected with one end of a resistor R1, the other end of the resistor R1 is connected with one end of a capacitor C1, the other end of the capacitor C1 is connected with the positive pole of the output end of the preamplification unit and used for introducing V0X(X =1,2,3, 4), the negative input end of the input stage of the integrated operational amplifier chip is connected with one end of a resistor R2, the other end of the resistor R2 is connected with GND, and the output end of the output stage of the integrated operational amplifier chip is used for outputting V1X(X =1,2,3, 4), the G + end of the output stage of the integrated operational amplifier chip is connected with the control unit to obtain the gain control signal VCGThe G-end of the output stage of the integrated operational amplifier chip is connected with one end of a resistor R3 and one end of a resistor R4, the other end of the resistor R3 is connected with GND, and the other end of the resistor R4 is connected with VCC.
5. The automatic gain control circuit of claim 1, wherein the operational amplifier signal conditioning unit employs an in-phase amplifier circuit including an operational amplifier for the voltage signal V1X(X =1,2,3, 4) performing constant gain amplification to obtain a non-saturated voltage V of a desired dynamic range2X(X =1,2,3, 4), then there is V2X=G2*V1X(X =1,2,3, 4), wherein G2The gain of the operational amplifier signal conditioning unit is a fixed value.
6. The control circuit for the automatic gain of a photodetection system according to claim 5, characterized in that the gain of the whole system is G = G1*G2。
7. The control circuit of the automatic gain of the photo-detection system according to claim 1, wherein the threshold comparison circuit unit comprises a four-way voltage summation circuit and a comparator, the four-way voltage summation circuit is used for summing the input V2X(X =1,2,3, 4) to produce Σ V2X(X =1,2,3, 4), the comparator for comparing Σ V2X(X =1,2,3, 4) and the threshold signal TH: if Σ V2X(X =1,2,3, 4) is greater than the threshold signal TH, returning a comparison signal CMP =1 to the control unit; otherwise, return ratioComparing the signal CMP =0 to the control unit;
the control unit is used for controlling the start of a peak holding function of the peak holding circuit unit and the start of an AD sampling function of the A/D sampling circuit unit when CMP =1 according to the value of the comparison signal CMP.
8. The circuit of claim 1, wherein the control signal CTRL comprises an enable signal CS, a start switching signal CONVST, and a read/write signal RD, and the a/D sampling circuit unit returns the AD sampling result to the control unit through the 12-bit parallel bus.
9. The control circuit for the automatic gain of the photodetection system according to claim 1, characterized in that:
the control unit comprises a single chip microcomputer, an FPGA and an operational amplifier; the single chip microcomputer and the FPGA form a whole, are connected with the A/D sampling circuit unit and the peak value holding circuit unit, are connected with the threshold comparison circuit unit through one operational amplifier, and are connected with the variable gain amplification unit through the other operational amplifier;
the singlechip is used for outputting V through the DA functionDA0The threshold comparison circuit unit is connected with the operational amplifier to generate a threshold signal TH with proper voltage and transmit the threshold signal TH to the threshold comparison circuit unit;
the FPGA is used for receiving the CMP comparison signal returned by the threshold comparison circuit unit; when the returned CMP comparison signal is 1, a peak hold circuit GATE signal GATE is generatedX(X =1,2,3, 4) is transmitted to the peak hold circuit unit to cause the peak hold circuit unit to turn on the peak hold function;
the FPGA is used for generating a control signal CTRL and transmitting the control signal CTRL to the A/D sampling circuit unit;
the singlechip is used for receiving an AD sampling result returned by the A/D sampling circuit unit through a 12-bit parallel port;
the singlechip is used for outputting V through the DA functionDA1Connected with the operational amplifier to generate a gain control signal V with proper voltageCGThe signal is transmitted to a variable gain amplification unit to adjust the gain.
10. A method for controlling the automatic gain of a photodetecting system, which is implemented by the circuit for controlling the automatic gain of a photodetecting system according to any one of claims 1 to 9, the method comprising the steps of:
converting an optical signal into a voltage signal V by a four-quadrant detector and a pre-amplification unit0X（X=1,2,3,4）；
By a variable gain amplifying unit according to a gain control signal V generated by a control unitCGFor input voltage signal V0X(X =1,2,3, 4), and a voltage signal V is obtained after enlargement or reduction1X（X=1,2,3,4）；
Voltage signal V is adjusted through operational amplifier signal conditioning unit1X(X =1,2,3, 4) and obtaining a voltage signal V after amplitude conditioning2X（X=1,2,3,4）；
Voltage signal V is compared by threshold value comparison circuit unit2X(X =1,2,3, 4) is compared with a threshold signal TH provided by the control unit and a comparison signal CMP is returned to the control unit according to the comparison result;
through a peak hold circuit unit according to a GATE signal GATE provided by a control unitX(X =1,2,3, 4), converting the voltage signal V2X(X =1,2,3, 4) widening a predetermined width to obtain a voltage signal V3X（X=1,2,3,4）；
Receiving a voltage signal V by an A/D sampling circuit unit3X(X =1,2,3, 4), and starts AD sampling according to a control signal CTRL provided by the control unit, and sends the sampling result to the control unit;
providing a threshold signal TH to the threshold comparison circuit unit through the control unit, receiving a comparison signal CMP returned by the threshold comparison circuit unit, and judging whether to start the peak holding circuit and whether to send a control signal CTRL according to the comparison signal CMP so as to enable the A/D sampling circuit unit to start AD sampling; and receiving the AD sampling result through the control unit, and giving out a gain control signal V according to the sum of four sampled voltagesCGAnd adjusting the gain of the variable gain amplifying unit in real time in reaction to the variable gain amplifying unit.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113890497A (en) * | 2021-12-07 | 2022-01-04 | 江苏雷华防务科技有限公司 | Laser pulse signal regulation control circuit and control method for laser guidance |
| CN115372942A (en) * | 2022-10-21 | 2022-11-22 | 北京微厘光电技术有限公司 | Echo processing circuit of laser range finder |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4982078A (en) * | 1989-12-19 | 1991-01-01 | Spectra-Physics, Inc. | Beam position sensor with time shared normalizing circuit |
| CN101158590A (en) * | 2007-11-13 | 2008-04-09 | 长春理工大学 | Complete digitisation 4 quadrant detector detecting laser beam deflection angle device and method |
| CN101420209A (en) * | 2008-11-21 | 2009-04-29 | 北京时代民芯科技有限公司 | High speed large dynamic range digital automatic gain control circuit |
| CN103499819A (en) * | 2013-09-22 | 2014-01-08 | 中国科学院光电技术研究所 | Measuring device and method for target line-of-sight angel offset and distance |
| CN107229042A (en) * | 2017-05-11 | 2017-10-03 | 湖北三江航天万峰科技发展有限公司 | A kind of laser signal detection means and control method based on DSP embedded systems |
-
2021
- 2021-01-08 CN CN202110025016.8A patent/CN112688649B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4982078A (en) * | 1989-12-19 | 1991-01-01 | Spectra-Physics, Inc. | Beam position sensor with time shared normalizing circuit |
| CN101158590A (en) * | 2007-11-13 | 2008-04-09 | 长春理工大学 | Complete digitisation 4 quadrant detector detecting laser beam deflection angle device and method |
| CN101420209A (en) * | 2008-11-21 | 2009-04-29 | 北京时代民芯科技有限公司 | High speed large dynamic range digital automatic gain control circuit |
| CN103499819A (en) * | 2013-09-22 | 2014-01-08 | 中国科学院光电技术研究所 | Measuring device and method for target line-of-sight angel offset and distance |
| CN107229042A (en) * | 2017-05-11 | 2017-10-03 | 湖北三江航天万峰科技发展有限公司 | A kind of laser signal detection means and control method based on DSP embedded systems |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113890497A (en) * | 2021-12-07 | 2022-01-04 | 江苏雷华防务科技有限公司 | Laser pulse signal regulation control circuit and control method for laser guidance |
| CN113890497B (en) * | 2021-12-07 | 2022-04-05 | 江苏雷华防务科技有限公司 | Laser pulse signal regulation control circuit and control method for laser guidance |
| CN115372942A (en) * | 2022-10-21 | 2022-11-22 | 北京微厘光电技术有限公司 | Echo processing circuit of laser range finder |
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