Driving circuit of laser sensor and laser speed measuring device

Abstract

The invention discloses a driving circuit of a laser sensor and a laser speed measuring device. The driving circuit comprises a constant current source module and a temperature compensation module. The constant current source module is used for outputting stable driving current; and the temperature compensation module is used for compensating the driving current according to the environment temperature. The driving circuit of the laser sensor provided by the invention can provide stable driving current, ensures that the laser sensor can output stable power, improves the stability and reliability of the laser sensor, further improves the measurement result of the laser sensor, and meets the requirement of high-precision measurement.

Description

Technical Field

[0001] This invention relates to the field of laser sensor technology, and in particular to a driving circuit for a laser sensor and a laser velocimetry device. Background Technology

[0002] A laser sensor measures the displacement of a target object by emitting a laser beam and receiving the reflected light, thereby enabling velocity measurement. Due to its advantages such as fast response, high resolution, and high accuracy, it is widely used in various position detection systems.

[0003] When laser sensors measure speed, a driving circuit is required to supply current to the laser sensor. However, the current output stability of existing laser sensor driving circuits is insufficient, affecting the output power and measurement accuracy of the laser diode, thus preventing the laser sensor from meeting higher speed measurement requirements. Summary of the Invention

[0004] This invention provides a driving circuit for a laser sensor and a laser velocimetry device to solve the problem of insufficient current stability in the output of existing driving circuits.

[0005] According to one aspect of the present invention, a driving circuit for a laser sensor is provided, comprising: a constant current source module and a temperature compensation module;

[0006] The constant current source module is used to output a stable drive current;

[0007] The temperature compensation module is used to compensate the drive current according to the ambient temperature.

[0008] Optionally, the driving circuit further includes a driving current output terminal; the temperature compensation module includes a thermistor;

[0009] The first output terminal of the constant current source module is connected to the drive current output terminal;

[0010] The first end of the thermistor is connected to an external power supply or to the second output end of the constant current source module, and the second end of the thermistor is connected to the drive current output end; the thermistor is used to change its resistance value according to the ambient temperature to compensate for the drive current.

[0011] Optionally, the driving circuit further includes a driving current output terminal; the temperature compensation module includes a thermistor; the constant current source module includes a reference voltage source, a first switching unit, and an error determination unit.

[0012] The first output terminal of the reference voltage source is connected to the first input terminal of the first switching unit, and the second output terminal of the reference voltage source is connected to the first input terminal of the error determination unit; the reference voltage source is used to provide the reference voltage to the error determination unit.

[0013] The second input terminal of the error determination unit is connected to the position feedback voltage, the output terminal of the error determination unit is connected to the control terminal of the first switching unit, and the output terminal of the first switching unit is connected to the drive current output terminal; the error determination unit is used to output an error signal based on the position feedback voltage and the reference voltage, and to control the state of the first switching unit based on the error signal;

[0014] The first end of the thermistor is connected to the output end of the error determination unit, and the second end of the thermistor is connected to the control end of the first switching unit; the thermistor is used to change its resistance value according to the ambient temperature to control the conduction state of the first switching unit.

[0015] Optionally, the drive circuit may further include a protection module;

[0016] The control terminal of the protection module is connected to the second output terminal of the reference voltage source; the reference voltage source is also used to provide the reference voltage to the protection module.

[0017] The input terminal of the protection module is connected to the drive current output terminal, and the output terminal of the protection module is connected to the input terminal of the laser diode. The protection module is used to acquire the current and voltage flowing through the laser diode and the temperature of the laser diode, and to determine whether overcurrent, overvoltage, and overtemperature have occurred based on the reference voltage.

[0018] And / or, the drive circuit further includes a feedback module;

[0019] The output terminal of the feedback module is connected to the control terminal of the first switching unit; the feedback module is used to obtain the output power of the laser diode and output a feedback signal according to the output power to control the state of the first switching unit to adjust the driving current.

[0020] Optionally, the drive circuit includes the protection module; the protection module includes an overcurrent protection unit, an overvoltage protection unit, an overtemperature protection unit, a second switching unit, and a voltage comparison unit;

[0021] The input terminal of the overcurrent protection unit is connected to the drive current output terminal, the first output terminal of the overcurrent protection unit is connected to the first input terminal of the second switching unit, and the second output terminal of the overcurrent protection unit is connected to the first input terminal of the voltage comparison unit; the overcurrent protection unit is used to acquire the current flowing through the laser diode and output the current sampling signal to the voltage comparison unit.

[0022] The first terminal of the overvoltage protection unit is connected to the input terminal of the laser diode, the second terminal of the overvoltage protection unit is connected to the output terminal of the laser diode, and the output terminal of the overvoltage protection unit is connected to the second input terminal of the voltage comparison unit; the overvoltage protection unit is used to detect the voltage across the laser diode and output the voltage sampling signal to the voltage comparison unit.

[0023] The output terminal of the over-temperature protection unit is connected to the third input terminal of the voltage comparison unit; the over-temperature protection unit is used to acquire the temperature information of the laser diode and output the temperature sampling signal value to the voltage comparison unit.

[0024] The fourth input terminal of the voltage comparison unit serves as the control terminal of the protection module. The output terminal of the voltage comparison unit is connected to the control terminal of the second switching unit, and the output terminal of the second switching unit is connected to the input terminal of the laser diode. The voltage comparison unit is used to control the state of the second switching unit based on the relationship between the current sampling signal and the reference voltage, the relationship between the voltage sampling signal and the reference voltage, and the relationship between the temperature sampling signal and the reference voltage.

[0025] Optionally, the overcurrent protection unit includes a current sampling subunit and a differential amplifier subunit;

[0026] The first terminal of the current sampling subunit serves as the input terminal of the overcurrent protection unit, and the second terminal of the current sampling subunit serves as the first output terminal of the overcurrent protection unit; the current sampling subunit is used to acquire the current flowing through the laser diode;

[0027] The first input terminal of the differential amplifier subunit is connected to the first terminal of the current sampling subunit, the second input terminal of the differential amplifier subunit is connected to the second terminal of the current sampling subunit, and the output terminal of the differential amplifier subunit serves as the second output terminal of the overcurrent protection unit. The differential amplifier subunit is used to amplify the current flowing through the laser diode and output the current sampling signal to the voltage comparison unit.

[0028] Optionally, the overvoltage protection unit includes a voltage sampling subunit;

[0029] The first end of the voltage sampling subunit is connected to the input end of the laser diode, the second end of the voltage sampling subunit is connected to the output end of the laser diode, and the output end of the voltage sampling subunit is connected to the second input end of the voltage comparison unit; the voltage sampling subunit is used to acquire the voltage of the laser diode and output a voltage sampling signal to the voltage comparison unit.

[0030] Optionally, the over-temperature protection unit includes a temperature sampling subunit and a signal conditioning subunit;

[0031] The temperature sampling subunit is attached to the heat sink of the laser diode and is used to obtain the temperature information of the laser diode.

[0032] The input terminal of the signal conditioning subunit is connected to the output terminal of the temperature sampling subunit, and the output terminal of the signal conditioning subunit is connected to the third input terminal of the voltage comparison unit; the signal conditioning subunit is used to output a temperature sampling signal according to the temperature information.

[0033] Optionally, the driving circuit includes the feedback module; the feedback module includes a photoelectric detection unit, a signal processing unit, and a control unit;

[0034] The photoelectric detection unit includes a photodiode and a load resistor;

[0035] The anode of the photodiode is grounded, and the cathode of the photodiode is connected to the first end of the load resistor. The photodiode is used to obtain the output power of the laser diode and output an electrical signal according to the output power.

[0036] The second end of the load resistor is connected to the input end of the signal processing unit; the load resistor is used to convert the electrical signal into a detection signal.

[0037] The signal processing unit includes a first operational amplifier subunit, a filtering subunit, a peak detection subunit, and a second operational amplifier subunit.

[0038] The input terminal of the first operational amplifier subunit is connected to the second terminal of the load resistor, and is used to amplify the detection signal;

[0039] The input terminal of the filtering subunit is connected to the output terminal of the first operational amplification subunit, and is used to filter the amplified detection signal.

[0040] The input terminal of the peak detection subunit is connected to the output terminal of the filtering subunit, and is used to extract the peak voltage of the detection signal after filtering.

[0041] The input terminal of the second operational amplifier subunit is connected to the output terminal of the peak detection subunit, and the output terminal of the second operational amplifier subunit is connected to the input terminal of the control unit; the second operational amplifier subunit is used to amplify the peak voltage output by the peak detection subunit and output the feedback signal to the control unit;

[0042] The output terminal of the control unit serves as the output terminal of the feedback module; the control unit is used to control the state of the first switching unit according to the feedback signal, so as to adjust the drive current.

[0043] According to another aspect of the present invention, a laser velocimetry device is provided, comprising a laser sensor and a driving circuit for the laser sensor as described above.

[0044] The technical solution of this invention provides a stable drive current to the laser sensor through a constant current source module, ensuring that the drive current is unaffected by power supply fluctuations. A temperature compensation module compensates for the temperature drift caused by ambient temperature variations in the drive current output from the constant current source module. By employing both the constant current source module and the temperature compensation module, a stable drive current is provided to the laser sensor, ensuring stable power output, enhancing anti-interference capabilities, improving the stability and reliability of the laser sensor, and ultimately improving the measurement results to meet the requirements of high-precision measurement.

[0045] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 A schematic diagram of the structure of a driving circuit for a laser sensor provided in an embodiment of the present invention;

[0048] Figure 2 A schematic diagram of the driving circuit for another laser sensor provided in an embodiment of the present invention;

[0049] Figure 3 A schematic diagram of the driving circuit for another laser sensor provided in an embodiment of the present invention;

[0050] Figure 4 A schematic diagram of the driving circuit for another laser sensor provided in an embodiment of the present invention;

[0051] Figure 5 A schematic diagram of the driving circuit for another laser sensor provided in an embodiment of the present invention;

[0052] Figure 6 A schematic diagram of the driving circuit for another laser sensor provided in an embodiment of the present invention;

[0053] Figure 7 This is a schematic diagram of the driving circuit for another laser sensor provided in an embodiment of the present invention. Detailed Implementation

[0054] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0055] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0056] Figure 1 This is a schematic diagram of the driving circuit for a laser sensor provided in an embodiment of the present invention. See also... Figure 1 The drive circuit 100 includes a constant current source module 10 and a temperature compensation module 20; the constant current source module 10 is used to output a stable drive current; the temperature compensation module 20 is used to compensate the drive current according to the ambient temperature.

[0057] Specifically, high-voltage circuit breakers, as the most important switching equipment on high-voltage lines, are used to cut off and connect high-voltage lines. Their opening and closing speed is crucial to the safe operation of the power system. The opening and closing speed of high-voltage circuit breakers can be measured by a laser sensor. The normal operation of the laser sensor requires a drive circuit to output a drive current to drive the laser sensor to emit a laser, thus measuring the opening and closing speed of the high-voltage short circuit. The drive circuit 100 of the laser sensor may include a constant current source module 10 and a temperature compensation module 20. The constant current source module 10 can output a stable current, providing a stable drive current for the laser sensor. Since high-voltage lines are all located outdoors, the ambient temperature varies greatly. The drive current output by the constant current source module 10 will fluctuate due to changes in ambient temperature, causing instability in the drive current of the laser sensor, thereby affecting the measurement results of the laser diode. A temperature compensation module 20 can be set to compensate for the temperature of the drive current output by the constant current source module 10, reducing the impact of temperature changes on the drive current. The laser sensor needs to reach a certain threshold current to emit a laser, and this threshold current increases with increasing ambient temperature. The temperature compensation module 20 can compensate the drive current according to changes in ambient temperature to drive the laser sensor to emit laser light. For example, when the ambient temperature is high, a larger current can be compensated for the drive current; when the ambient temperature is low, a smaller current can be compensated for the drive current, or no compensation may be performed. The temperature compensation module 20 can also change its own resistance according to changes in ambient temperature to adjust the magnitude of the drive current. For example, when the ambient temperature is high, the temperature compensation module 20 reduces its own resistance; when the ambient temperature is low, the temperature compensation module 20 increases its own resistance.

[0058] The laser sensor driving circuit provided in this embodiment of the invention provides a stable driving current to the laser sensor through a constant current source module, ensuring that the driving current is not affected by power supply fluctuations. A temperature compensation module compensates for the temperature drift caused by ambient temperature by compensating for the driving current output from the constant current source module. By employing both the constant current source module and the temperature compensation module, a stable driving current is provided to the laser sensor, ensuring that the laser sensor can output stable power, enhancing anti-interference capabilities, improving the stability and reliability of the laser sensor, and ultimately improving the measurement results of the laser sensor to meet the requirements of high-precision measurement.

[0059] Optional, Figure 2 This is a schematic diagram of the driving circuit for another laser sensor provided in an embodiment of the present invention. Based on the above embodiments, see... Figure 2The driving circuit 100 also includes a driving current output terminal 30; the temperature compensation module 20 includes a thermistor 21; the first output terminal of the constant current source module 10 is connected to the driving current output terminal 30; the first terminal of the thermistor 21 is connected to an external power supply or to the second output terminal of the constant current source module 10, and the second terminal of the thermistor 21 is connected to the driving current output terminal 30; the thermistor 21 is used to change its resistance value according to the ambient temperature to compensate for the driving current.

[0060] Specifically, the drive current output by the constant current source module 10 can be supplied to the laser sensor through the drive current output terminal 30. The temperature compensation module 20 may include a thermistor 21. One end of the thermistor 21 is connected to the drive current output terminal 30, and the other end can be connected to an external power supply. The external power supply provides the current that needs to be compensated to compensate the drive current. The other end of the thermistor 21 can also be connected to the second output terminal of the constant current source module 20, which can provide the current that needs to be compensated to compensate for the influence of ambient temperature on the drive current. The thermistor 21 can change its resistance according to the ambient temperature, thereby adjusting the magnitude of the current that needs to be compensated to compensate the drive current, so that the laser sensor has a stable drive current.

[0061] Optional, Figure 3 This is a schematic diagram of the driving circuit for another laser sensor provided in an embodiment of the present invention. Based on the above embodiments, see... Figure 3 The driving circuit 100 also includes a driving current output terminal 30; the temperature compensation module 20 includes a thermistor 21; the constant current source module 10 includes a reference voltage source 11, a first switching unit 12, and an error determination unit 13: the first output terminal of the reference voltage source 11 is connected to the first input terminal of the first switching unit 12, and the second output terminal of the reference voltage source 11 is connected to the first input terminal of the error determination unit 13; the reference voltage source 11 is used to provide a reference voltage to the error determination unit 13; the second input terminal of the error determination unit 13 is connected to the position feedback voltage, the output terminal of the error determination unit 13 is connected to the control terminal of the first switching unit 12, and the output terminal of the first switching unit 12 is connected to the driving current output terminal 30; the error determination unit 13 is used to output an error signal according to the position feedback voltage and the reference voltage, and control the state of the first switching unit 12 according to the error signal; the first terminal of the thermistor 21 is connected to the output terminal of the error determination unit 13, and the second terminal of the thermistor 21 is connected to the control terminal of the first switching unit 12; the thermistor 21 is used to change its resistance value according to the ambient temperature to control the conduction state of the first switching unit 12.

[0062] Specifically, the reference voltage source 11 in the constant current source module 10 can provide a stable voltage to the laser sensor and also provide a reference voltage to the error determination unit 13. The error determination unit 13 is used to generate an error signal based on the reference voltage and the position feedback voltage. The error signal can adjust the conduction state of the first switching unit 12. The position feedback voltage can be a feedback signal of the actual drive current output by the constant current source module 10. The reference voltage is not specifically limited in this embodiment and can be set according to actual needs. For example, if the drive current output by the constant current source module 10 is small, the feedback voltage is less than the reference voltage. The difference between the reference voltage and the position feedback voltage is used to obtain an error voltage, which is greater than zero. The error determination unit 13 amplifies the error voltage to obtain an error signal. The error signal controls the conduction state of the first switching unit 12 to increase, thereby increasing the drive current. If the drive current output by the constant current source module 10 is large, the difference between the reference voltage and the position feedback voltage is used to obtain an error voltage less than zero. The error determination unit 13 processes the error voltage to obtain an error signal, which reduces the conduction state of the first switching unit 12, thereby reducing the drive current. A thermistor 21 is connected in series between the error determination unit 13 and the control terminal of the first switching unit 12. The thermistor 21 can change its resistance according to changes in ambient temperature, adjusting the magnitude of the error signal and controlling the conduction state of the first switching unit 12 to regulate the drive current. The thermistor 21 can be an NTC thermistor, and the first switching unit can be an IRF540N power transistor. At higher ambient temperatures, the resistance of the thermistor 21 decreases, resulting in a larger error signal, thus a greater conduction state of the first switching unit 12 and a larger output drive current. At lower ambient temperatures, the resistance of the thermistor 21 increases, resulting in a smaller error signal, thus a lesser conduction state of the first switching unit 12 and a smaller output drive current.

[0063] Optional, Figure 4 This is a schematic diagram of the driving circuit for another laser sensor provided in an embodiment of the present invention. Figure 5 This is a schematic diagram of the driving circuit for another laser sensor provided in an embodiment of the present invention. Based on the above embodiments, see... Figure 4 and Figure 5The driving circuit 100 also includes a protection module 40; the control terminal of the protection module 40 is connected to the second output terminal of the reference voltage source 11; the reference voltage source 11 is also used to provide a reference voltage to the protection module 40; the input terminal of the protection module 40 is connected to the drive current output terminal 30, and the output terminal of the protection module 40 is connected to the input terminal of the laser diode 50; the protection module 40 is used to acquire the current flowing through the laser diode 50, the voltage and the temperature of the laser diode, and to determine whether overcurrent, overvoltage and overtemperature have occurred based on the reference voltage; and / or, the driving circuit 100 also includes a feedback module 60; the output terminal of the feedback module 60 is connected to the control terminal of the first switching unit 12; the feedback module 60 is used to acquire the output power of the laser diode 50, and to output a feedback signal based on the output power to control the state of the first switching unit 12 to adjust the drive current.

[0064] Specifically, the driving circuit 100 may include a protection module 40, which can monitor the current and voltage flowing through the laser diode and the temperature of the laser diode in real time. In the event of overcurrent, overvoltage, or overtemperature, the protection module 40 can promptly cut off the circuit to protect the laser diode and prevent damage. The driving circuit 100 may also include a feedback module 60, which can monitor the output power of the laser diode 50 in real time and generate a feedback signal based on the output power. The output terminal of the feedback module 60 is connected to the control terminal of the first switching unit 12, and the feedback signal output by the feedback module 60 can control the conduction state of the first switching unit 12. For example, when the output power of the laser diode 50 is low, the feedback signal can control the conduction state of the first switching unit 12 to increase, thereby increasing the drive current output by the constant current source module 10 and thus increasing the output power of the laser diode 50. When the output power of the laser diode 50 is high, the feedback signal can control the conduction state of the first switching unit 12 to decrease, thereby reducing the drive current output by the constant current source module 10 and thus reducing the output power of the laser diode 50.

[0065] Optional, Figure 6 This is a schematic diagram of the driving circuit for another laser sensor provided in an embodiment of the present invention. Based on the above embodiments, see... Figure 6The driving circuit 100 includes a protection module 40; the protection module 40 includes an overcurrent protection unit 41, an overvoltage protection unit 42, an overtemperature protection unit 43, a second switching unit 44, and a voltage comparison unit 45; the input terminal of the overcurrent protection unit 41 is connected to the driving current output terminal 30, the first output terminal of the overcurrent protection unit 41 is connected to the first input terminal of the second switching unit 44, and the second output terminal of the overcurrent protection unit 41 is connected to the first input terminal of the voltage comparison unit 45; the overcurrent protection unit 41 is used to acquire the current flowing through the laser diode 50 and output the current sampling signal to the voltage comparison unit 45; the first terminal of the overvoltage protection unit 42 is connected to the input terminal of the laser diode 50, the second terminal of the overvoltage protection unit 42 is connected to the output terminal of the laser diode 50, and the output terminal of the overvoltage protection unit 42 is connected to the voltage comparison unit 45. The second input terminal is connected; the overvoltage protection unit 42 is used to detect the voltage across the laser diode 50 and output the voltage sampling signal to the voltage comparison unit 45; the output terminal of the overtemperature protection unit 43 is connected to the third input terminal of the voltage comparison unit 45; the overtemperature protection unit 43 is used to acquire the temperature information of the laser diode and output the temperature sampling signal value to the voltage comparison unit 45; the fourth input terminal of the voltage comparison unit 45 serves as the control terminal of the protection module 40, the output terminal of the voltage comparison unit 45 is connected to the control terminal of the second switching unit 44, and the output terminal of the second switching unit 44 is connected to the input terminal of the laser diode 50; the voltage comparison unit 45 is used to control the state of the second switching unit 44 according to the relationship between the current sampling signal and the reference voltage, the relationship between the voltage sampling signal and the reference voltage, and the relationship between the temperature sampling signal and the reference voltage.

[0066] Specifically, the overcurrent protection unit 41 in the protection module 40 is located between the laser diode 50 and the drive current output terminal 30. It can monitor the magnitude of the drive current flowing through it, generate a current sampling signal, and output the current sampling signal to the voltage comparison unit 45. The voltage comparison unit 45 determines the state of the second switching unit 44 based on the relationship between the current sampling signal and the reference voltage. When the current sampling signal is greater than the reference voltage, the second switching unit 44 is controlled to be in the off state to prevent overcurrent damage to the laser diode 50. The overvoltage protection unit 42 is connected in parallel across the laser diode 50 to monitor the voltage across the laser diode 50 and outputs the voltage sampling signal to the voltage comparison unit 45. The voltage comparison unit 50 can control the state of the second switching unit 44 based on the relationship between the voltage sampling signal and the reference voltage. The overtemperature protection unit 43 can acquire the temperature information of the laser diode 50 and generate a temperature sampling signal. The voltage comparison unit 45 can also control the state of the second switching unit 44 based on the relationship between the temperature sampling signal and the reference voltage. In the event of overcurrent, overvoltage, or overtemperature, the second switching unit 44 will be in the off state to prevent damage to the laser diode. The second switching unit 44 can use an IRF540N MOSFET switch. The voltage comparison unit 45 can use an LM311 high-speed voltage comparator.

[0067] Optionally, based on the above embodiments, see also... Figure 6 The overcurrent protection unit 41 includes a current sampling subunit 411 and a differential amplifier subunit 412. The first terminal of the current sampling subunit 411 serves as the input terminal of the overcurrent protection unit 411, and the second terminal of the current sampling subunit 411 serves as the first output terminal of the overcurrent protection unit 411. The current sampling subunit 411 is used to acquire the current flowing through the laser diode. The first input terminal of the differential amplifier subunit 412 is connected to the first terminal of the current sampling subunit 411, and the second input terminal of the differential amplifier subunit 412 is connected to the second terminal of the current sampling subunit 411. The output terminal of the differential amplifier subunit 412 serves as the second output terminal of the overcurrent protection unit 411. The differential amplifier subunit 412 is used to amplify the current flowing through the laser diode 50 and output the current sampling signal to the voltage comparison unit 45.

[0068] Specifically, the current sampling subunit 411 is connected in series between the drive current output terminal 30 and the second switching unit 44. The current sampling subunit 411 can acquire the drive current flowing through it. The current sampling subunit 411 can be a low-resistance, high-precision sampling resistor, which will not have a significant impact on the drive current, and can also convert the drive current into a voltage signal. The differential amplifier subunit 412 can amplify the voltage signal and generate a current sampling signal, which is output to the voltage comparison unit 45. The differential amplifier subunit 412 can be an OPA2188 operational amplifier. The amplification factor is not specifically limited in this embodiment of the invention and can be set according to actual needs.

[0069] Optionally, based on the above embodiments, see also... Figure 6 The overvoltage protection unit 42 includes a voltage sampling subunit 421; the first end of the voltage sampling subunit 421 is connected to the input end of the laser diode 50, the second end of the voltage sampling subunit 421 is connected to the output end of the laser diode 52, and the output end of the voltage sampling subunit 421 is connected to the second input end of the voltage comparison unit 45; the voltage sampling subunit 421 is used to acquire the voltage of the laser diode 50 and output a voltage sampling signal to the voltage comparison unit 45.

[0070] Specifically, the voltage sampling subunit 421 is connected in parallel across the laser diode 50 to acquire the voltage across the laser diode 50. The voltage sampling subunit 421 can be a high-precision resistor network that divides the voltage across the laser diode 50. The divided voltage is the voltage sampling signal, which is output to the voltage comparison unit 45. The voltage division ratio is not specifically limited in this embodiment and can be set according to actual needs. The voltage comparison unit 45 can control the second switching unit 44 to turn on or off based on the relationship between the voltage sampling signal and the reference voltage. When the voltage sampling signal is greater than the reference voltage, the second switching unit 44 can be turned off to prevent overvoltage damage to the laser diode 50.

[0071] Optionally, based on the above embodiments, see also... Figure 6 The over-temperature protection unit 43 includes a temperature sampling subunit 431 and a signal conditioning subunit 432. The temperature sampling subunit 431 is attached to the heat sink of the laser diode 50 and is used to acquire the temperature information of the laser diode 50. The input terminal of the signal conditioning subunit 432 is connected to the output terminal of the temperature sampling subunit 431, and the output terminal of the signal conditioning subunit 432 is connected to the third input terminal of the voltage comparison unit 45. The signal conditioning subunit 432 is used to output a temperature sampling signal according to the temperature information.

[0072] Specifically, the temperature sampling subunit 431 is used to acquire the temperature information of the laser diode 50 in real time. The temperature sampling subunit 431 can be an NTC thermistor, and its resistance changes according to the temperature of the laser diode 50, decreasing as the temperature of the laser diode 50 increases. The signal conditioning subunit 432 converts the resistance of the temperature sampling subunit 431 into a temperature sampling signal and outputs it to the voltage comparison unit 45. The signal conditioning subunit 432 can use an OPA2188 operational amplifier to form a signal conditioning circuit, and the output temperature sampling signal is proportional to the temperature acquired by the temperature sampling subunit 431. The voltage comparison unit 45 can then determine whether the laser diode 50 is overheating based on the relationship between the temperature sampling signal and the reference signal. When the temperature sampling signal is greater than the reference voltage, it indicates that the laser diode 50 has overheated, and the second switching unit 44 is turned off to prevent damage to the laser diode 50.

[0073] Optional, Figure 7 This is a schematic diagram of the driving circuit for another laser sensor provided in an embodiment of the present invention. Based on the above embodiments, see... Figure 7The driving circuit 100 includes a feedback module 60; the feedback module 60 includes a photoelectric detection unit 61, a signal processing unit 62, and a control unit 63; the photoelectric detection unit 61 includes a photodiode 611 and a load resistor 612; the anode of the photodiode 611 is grounded, and the cathode of the photodiode 611 is connected to the first end of the load resistor 612. The photodiode 611 is used to acquire the output power of the laser diode 50 and output an electrical signal according to the output power; the second end of the load resistor 612 is connected to the input end of the signal processing unit 62; the load resistor 612 is used to convert the electrical signal into a detection signal; the signal processing unit 62 includes a first operational amplifier subunit 621, a filter subunit 622, a peak detection subunit 623, and a second operational amplifier subunit 624; the input end of the first operational amplifier subunit 621 is connected to the second end of the load resistor 612 for... The detection signal is amplified; the input of the filtering subunit 622 is connected to the output of the first operational amplifier subunit 621, and is used to filter the amplified detection signal; the input of the peak detection subunit 623 is connected to the output of the filtering subunit 622, and is used to extract the peak voltage of the filtered detection signal; the input of the second operational amplifier subunit 624 is connected to the output of the peak detection subunit 623, and the output of the second operational amplifier subunit 624 is connected to the input of the control unit 63; the second operational amplifier subunit 624 is used to amplify the peak voltage output by the peak detection subunit 623, and outputs a feedback signal to the control unit 63; the output of the control unit 63 serves as the output of the feedback module 60; the control unit 63 is used to control the state of the first switching unit 12 according to the feedback signal to adjust the drive current.

[0074] Specifically, photodiode 611 requires a reverse bias voltage during normal operation. The anode of photodiode 611 can be grounded, and the cathode can be connected to the load resistor 612 and the bias voltage. The bias voltage can be provided by an external power supply. Photodiode 611 receives the laser emitted by laser diode 50 and converts it into an electrical signal using the photoelectric effect. The electrical signal is then converted into a voltage-type detection signal via the load resistor 612. The first operational amplifier subunit 621 amplifies the detection signal; the amplification factor is not specifically limited in this embodiment and can be set according to actual needs. The filtering subunit 622 filters the amplified detection signal to remove high-frequency noise and interference signals. The peak detection subunit 623 extracts the peak voltage of the amplified and filtered detection signal. The second operational amplifier subunit 624 further amplifies the extracted peak voltage to generate a feedback signal, which the control unit 63 uses to control the first switching unit 12. The control unit 63 can calculate the output power of the laser diode 50 based on the feedback signal and compare it with the target power. It then adjusts the state of the first switching unit 12 to control the drive current output by the constant current source module 10. When the output power of the laser diode 50 is lower than the target power, the control unit 12 is increased in conduction state, resulting in a larger drive current and thus increasing the output power of the laser diode 50. When the output power of the laser diode 50 is higher than the target power, the control unit 12 is decreased in conduction state, resulting in a smaller drive current and thus decreasing the output power of the laser diode 50.

[0075] The driving current provided by this invention is temperature-compensated by a temperature compensation circuit, avoiding the impact of temperature changes on the driving current. A protection module provides overcurrent, overvoltage, and overtemperature protection for the laser diode, effectively preventing damage due to abnormal conditions and improving the reliability and lifespan of the laser sensor. A feedback module enables closed-loop control of the laser diode, adjusting its output power in real time, thus improving measurement accuracy.

[0076] This invention also provides a laser velocimetry device. This laser velocimetry device includes a laser sensor and a driving circuit for the laser sensor provided in any of the above embodiments. Since the laser velocimetry device provided in this invention includes the driving circuit for the laser sensor provided in this invention, it also has the same beneficial effects, and will not be described again here.

[0077] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A driving circuit of a laser sensor, characterized by, The drive circuit comprises a constant current source module and a temperature compensation module. The constant current source module is configured to output a stable driving current. The temperature compensation module is configured to compensate the driving current according to an ambient temperature. The drive circuit further comprises a driving current output terminal; the temperature compensation module comprises a thermistor; 2. The drive circuit according to claim 1, characterized by a first output terminal of the constant current source module is connected with the driving current output terminal; a first terminal of the thermistor is connected with an external power supply or a second output terminal of the constant current source module, and a second terminal of the thermistor is connected with the driving current output terminal; the thermistor is configured to change its resistance value according to the ambient temperature, so as to compensate the driving current. The drive circuit further comprises a driving current output terminal; the temperature compensation module comprises a thermistor; the constant current source module comprises a reference voltage source, a first switch unit and an error determination unit:

3. The drive circuit according to claim 1, characterized by a first output terminal of the reference voltage source is connected with a first input terminal of the first switch unit, and a second output terminal of the reference voltage source is connected with a first input terminal of the error determination unit; the reference voltage source is configured to provide the reference voltage to the error determination unit; a second input terminal of the error determination unit is connected with a position feedback voltage, an output terminal of the error determination unit is connected with a control terminal of the first switch unit, and an output terminal of the first switch unit is connected with the driving current output terminal; the error determination unit is configured to output an error signal according to the position feedback voltage and the reference voltage, and control a state of the first switch unit according to the error signal; a first terminal of the thermistor is connected with the output terminal of the error determination unit, and a second terminal of the thermistor is connected with the control terminal of the first switch unit; the thermistor is configured to change its resistance value according to the ambient temperature, so as to control a conduction state of the first switch unit. The drive circuit further comprises a protection module; 4. The drive circuit according to claim 3, characterized in that, a control terminal of the protection module is connected with the second output terminal of the reference voltage source; the reference voltage source is further configured to provide the reference voltage to the protection module; an input terminal of the protection module is connected with the driving current output terminal, and an output terminal of the protection module is connected with an input terminal of a laser diode; the protection module is configured to acquire a current flowing through the laser diode, a voltage and a temperature of the laser diode, and determine whether overcurrent, overvoltage and overtemperature occur according to the reference voltage; And / or, the drive circuit further comprises a feedback module; an output terminal of the feedback module is connected with the control terminal of the first switch unit; the feedback module is configured to acquire an output power of the laser diode, and output a feedback signal according to the output power, so as to control a state of the first switch unit for adjusting the driving current. The drive circuit comprises the protection module; the protection module comprises an overcurrent protection unit, an overvoltage protection unit, an overtemperature protection unit, a second switch unit and a voltage comparison unit; 5. The drive circuit according to claim 4, characterized in that, ​ The input end of the overcurrent protection unit is connected with the driving current output end, the first output end of the overcurrent protection unit is connected with the first input end of the second switch unit, and the second output end of the overcurrent protection unit is connected with the first input end of the voltage comparison unit; The overcurrent protection unit is used for acquiring the current flowing through the laser diode and outputting a current sampling signal to the voltage comparison unit; The first end of the overvoltage protection unit is connected with the input end of the laser diode, the second end of the overvoltage protection unit is connected with the output end of the laser diode, and the output end of the overvoltage protection unit is connected with the second input end of the voltage comparison unit; the overvoltage protection unit is used for detecting the voltage across the laser diode and outputting a voltage sampling signal to the voltage comparison unit; The output end of the over-temperature protection unit is connected with the third input end of the voltage comparison unit; the over-temperature protection unit is used for acquiring the temperature information of the laser diode and outputting a temperature sampling signal to the voltage comparison unit; The fourth input end of the voltage comparison unit is used as the control end of the protection module, the output end of the voltage comparison unit is connected with the control end of the second switch unit, and the output end of the second switch unit is connected with the input end of the laser diode; the voltage comparison unit is used for controlling the state of the second switch unit according to the relationship between the current sampling signal and the reference voltage, the relationship between the voltage sampling signal and the reference voltage, and the relationship between the temperature sampling signal and the reference voltage.

6. The drive circuit according to claim 5, characterized in that, The overcurrent protection unit comprises a current sampling subunit and a differential amplification subunit; The first end of the current sampling subunit is used as the input end of the overcurrent protection unit, and the second end of the current sampling subunit is used as the first output end of the overcurrent protection unit; The current sampling subunit is used for acquiring the current flowing through the laser diode; The first input end of the differential amplification subunit is connected with the first end of the current sampling subunit, the second input end of the differential amplification subunit is connected with the second end of the current sampling subunit, and the output end of the differential amplification subunit is used as the second output end of the overcurrent protection unit; the differential amplification subunit is used for amplifying the current flowing through the laser diode and outputting the current sampling signal to the voltage comparison unit.

7. The drive circuit according to claim 5, characterized by The overvoltage protection unit comprises a voltage sampling subunit; The first end of the voltage sampling subunit is connected with the input end of the laser diode, the second end of the voltage sampling subunit is connected with the output end of the laser diode, and the output end of the voltage sampling subunit is connected with the second input end of the voltage comparison unit; the voltage sampling subunit is used for acquiring the voltage of the laser diode and outputting a voltage sampling signal to the voltage comparison unit.

8. The drive circuit of claim 5, wherein, The over-temperature protection unit comprises a temperature sampling subunit and a signal conditioning subunit; The temperature sampling subunit is attached to the heat sink of the laser diode and is used for acquiring the temperature information of the laser diode; The input end of the signal conditioning sub-unit is connected with the output end of the temperature sampling sub-unit, and the output end of the signal conditioning sub-unit is connected with the third input end of the voltage comparison unit; the signal conditioning sub-unit is used for outputting a temperature sampling signal according to the temperature information.

9. The drive circuit according to claim 4, characterized by The driving circuit comprises the feedback module; the feedback module comprises a photoelectric detection unit, a signal processing unit and a control unit; The photoelectric detection unit comprises a photodiode and a load resistor; The anode of the photodiode is grounded, the cathode of the photodiode is connected with the first end of the load resistor, and the photodiode is used for acquiring the output power of the laser diode and outputting an electric signal according to the output power; The second end of the load resistor is connected with the input end of the signal processing unit; the load resistor is used for converting the electric signal into a detection signal; The signal processing unit comprises a first operational amplification sub-unit, a filtering sub-unit, a peak value detection sub-unit and a second operational amplification sub-unit; The input end of the first operational amplification sub-unit is connected with the second end of the load resistor, and the first operational amplification sub-unit is used for amplifying the detection signal; The input end of the filtering sub-unit is connected with the output end of the first operational amplification sub-unit, and the filtering sub-unit is used for filtering the amplified detection signal; The input end of the peak value detection sub-unit is connected with the output end of the filtering sub-unit, and the peak value detection sub-unit is used for extracting the peak voltage of the filtered detection signal; The input end of the second operational amplification sub-unit is connected with the output end of the peak value detection sub-unit, and the output end of the second operational amplification sub-unit is connected with the input end of the control unit; The second operational amplification sub-unit is used for amplifying the peak voltage output by the peak value detection sub-unit and outputting the feedback signal to the control unit; The output end of the control unit serves as the output end of the feedback module; The control unit is used for controlling the state of the first switch unit according to the feedback signal, so as to adjust the driving current.

10. A laser velocimeter device, characterized by Comprise: A laser sensor and a driving circuit of the laser sensor according to any one of claims 1-9.

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