A pulse detection system and method

Abstract

This invention provides a pulse detection system and method. The pulse detection system includes a laser module for emitting laser light, comprising a laser and at least one switch; an average power detection module for detecting the average voltage of multiple pulses and generating a first detection result; a peak power detection module for detecting the peak voltage of a single pulse and generating a second detection result; a control module for processing data based on the first and second detection results and outputting a corresponding signal, which controls the on / off state of the switch; and a power supply module for providing electrical energy for the system's operation. This invention enables simultaneous detection of the peak power and average power of a pulse circuit, improving the safety of the pulse detection system.

Description

Technical Field

[0001] This invention relates to the field of laser technology, and more specifically to a pulse detection system and method. Background Technology

[0002] In existing technologies, lidar systems utilize the time required for pulsed laser light to travel between objects to measure the distance to that target. However, even extremely low laser energy can cause damage to the cornea or retina. Currently, commonly used international safety laser standards include the International Electrotechnical Commission standard (IEC 60825) and the American National Standards Institute standard (ANSI Z136), which specify the following standards in detail: 1. The radiation dose of any single pulse in a pulse sequence shall not exceed the maximum radiation dose of a single pulse; 2. The average radiation dose of multiple pulses over any duration T shall not exceed the maximum radiation dose of a single pulse during continuous irradiation time T within that pulse beam.

[0003] Currently, related products focus more on overall product performance. Considering development costs and failure probability, a common technique is to monitor the average power within a specific time period of a pulse sequence. This works by integrating and sampling the laser's operating current, converting the sampled signal into a DC level signal over a period of time, and finally controlling the main switch to stop laser emission when the DC level exceeds a safety threshold. However, based on eye safety standards, real-time power detection of any pulse is mandatory and represents the future trend. Detecting only the average power may not meet the standards. Existing technologies set fixed safety thresholds, but the photoelectric conversion efficiency, peak current, on-state voltage drop, and on-resistance of switching devices in a laser all change with temperature. For the same emission power, the operating current differs at different temperatures. Therefore, the safety threshold should be adjusted in real-time based on the ambient temperature. Summary of the Invention

[0004] In view of the problems in the prior art, the purpose of this invention is to provide a pulse detection system and method that can simultaneously detect the peak power and average power of a pulse circuit, thereby improving the accuracy and safety of the pulse detection system.

[0005] This invention provides a pulse detection system, comprising: a laser module for emitting laser light, including a laser and at least one switch; an average power detection module for detecting the average voltage of multiple pulses and generating a first detection result; a peak power detection module for detecting the peak voltage of a single pulse and generating a second detection result; a control module for performing data processing based on the first detection result and / or the second detection result and outputting a corresponding signal, the corresponding signal being used to control the on / off state of the switch; and a power supply module for providing power to the detection system.

[0006] In some embodiments, the laser module includes a first switch and a second switch, wherein the first switch is disposed between the power module and a first end of the laser, and the second switch is disposed at a second end of the laser.

[0007] In some embodiments, the corresponding signal includes a first pulse sequence signal and a control signal, wherein the control signal is used to control the on / off state of the first switch, and the first pulse sequence signal is used to control the on / off state of the second switch.

[0008] In some embodiments, the control module includes a first functional unit and a second functional unit. The first functional unit is used to output the first pulse sequence and adjust the duty cycle of the first pulse sequence according to the detection results of the peak power detection module and the average power detection module, so that the laser operates within a safe range. The second functional unit is used to output a control signal of the first switch to turn the laser on or off.

[0009] In some embodiments, a temperature detection module is further included, which is electrically connected to the control module and is used to detect temperature changes around the laser and output the detection results to the control module.

[0010] The control module also includes a fourth functional unit, which is used to read the temperature around the laser and output a power control signal to output a first safety threshold for controlling the average power detection module and a second safety threshold for controlling the peak power detection module.

[0011] In some embodiments, the temperature detection module includes a thermistor or a temperature sensor chip.

[0012] In some embodiments, a current sensor is further included, located between the power supply module and the average power detection module. The current sensor is used to detect changes in current in the circuit and convert the current change into a voltage change, so that the DC level emitted by the power supply module is converted into a pulse signal for the purpose of detecting the average power.

[0013] In some embodiments, the current sensor is a current-sensing resistor.

[0014] In some embodiments, the laser module includes an energy storage capacitor for storing charge to compensate for the charge at the moment the circuit of the laser module is turned on, thereby illuminating the laser in a timely manner.

[0015] In some embodiments, a chopper circuit is further included, which is used to regulate the voltage output by the power module to a level lower than a safe threshold voltage.

[0016] In some embodiments, the control module is configured to generate a second pulse sequence signal based on the first detection result and / or the second detection result, the second pulse sequence signal being used to control the operating state of the chopper circuit;

[0017] The control module also includes a third functional unit, which outputs a second pulse sequence when the peak power and the average power are detected to exceed the safety threshold, so as to reduce the voltage output by the power module to within the safety threshold.

[0018] In some embodiments, the first switch includes a field-effect transistor, a bipolar transistor, or a digital gate circuit.

[0019] In some embodiments, a driving circuit is further included, which is connected to the second switch. The driving circuit is used to increase the voltage and current of the first pulse sequence signal to control the rapid switching on and off of the second switch. The driving circuit includes a digital buffer chip or a transistor driver chip.

[0020] In some embodiments, the average power detection module and the peak power detection module are each electrically connected to the control module via an analog-to-digital conversion circuit;

[0021] The control module further includes a fifth functional unit, which is used to adjust the first safety threshold and the second safety threshold in real time, and compare the detection output with the corresponding safety threshold.

[0022] In some embodiments, the average power detection module includes a first part of an RC circuit and an analog-to-digital conversion circuit, the peak power detection module includes a second part of an analog-to-digital conversion circuit, and the first safety threshold and the second safety threshold are set in the control module.

[0023] In some embodiments, the average power detection module and the peak power detection module are each electrically connected to the control module via a comparator circuit.

[0024] In some embodiments, the average power detection module includes an RC circuit and a first comparator, wherein the positive input terminal of the first comparator is connected to the output terminal of the RC circuit, and the negative input terminal of the first comparator is connected to a first safety threshold.

[0025] In some embodiments, the peak power detection module includes a second comparator, the positive input of which is connected to the second switch, and the negative input of which is connected to a second safety threshold.

[0026] In some embodiments, the control module includes a counter unit. When the control module determines that the peak voltage of a single pulse exceeds a preset voltage threshold based on the second detection result, it controls the counter unit to start counting. When the count value of the counter unit is greater than a preset quantity threshold, it controls the first switch to open.

[0027] In some embodiments, the second switch is a high-frequency switching transistor, including an N-MOS transistor, a GaN transistor, a power transistor, or an insulated-gate bipolar transistor.

[0028] This invention provides an embodiment of a pulse detection method, employing the pulse detection system described above, the method comprising the following steps:

[0029] The laser module emits laser light;

[0030] The average power detection module detects the average voltage of multiple pulses and generates a first detection result;

[0031] The peak power detection module detects the peak voltage of a single pulse and generates a second detection result;

[0032] The control module processes the data based on the first and second detection results and outputs corresponding signals.

[0033] In some embodiments, the laser module further includes a first switch and a second switch; the control module outputs a first pulse sequence signal and a control signal; the control module receives a first detection result and a second detection result and performs data processing; the method includes the following steps:

[0034] The control module determines whether the peak voltage in the current pulse exceeds the second safety threshold based on the second detection result; the control module determines whether the average voltage of the laser in multiple pulses exceeds the first safety threshold based on the first detection result.

[0035] When it is determined that the first detection result exceeds the first safety threshold and / or the second detection result exceeds the second safety threshold;

[0036] The control module outputs a first control signal to disconnect the first switch, and the laser is turned off.

[0037] In some embodiments, when it is determined that the peak voltage within the current pulse exceeds a first safety threshold, the method includes the following steps:

[0038] The counter of the control module starts counting;

[0039] When the counter count exceeds the safety pulse count setting, the control module outputs the first control signal, and the laser is turned off.

[0040] In some embodiments, after the laser is turned off, the method further includes the following steps:

[0041] The controller module adjusts the voltage of the first pulse sequence;

[0042] When it is determined that the first detection result is less than the first safety threshold and the second detection result is less than the second safety threshold, the control module outputs a second control signal;

[0043] After receiving the second control signal, the first switch turns off and the circuit of the laser module is turned on, and the laser emits laser light normally.

[0044] In some embodiments, the system further includes a chopper circuit, and after the laser is turned off, the system further includes the following steps:

[0045] The control module outputs a second pulse sequence signal;

[0046] The chopper circuit receives the second pulse sequence signal to adjust the input voltage of the power module;

[0047] When it is determined that the first detection result is less than the first safety threshold and the second detection result is less than the second safety threshold, the control module outputs a second control signal;

[0048] After receiving the second control signal, the first switch turns off and turns on, the circuit of the laser module is turned on, and the laser emits laser normally.

[0049] In some embodiments, the system further includes a temperature detection module, and the method further includes the following steps:

[0050] The temperature detection module detects the temperature of the laser and the circuit board around it, and sends the detection results to the control module.

[0051] After reading the temperature, the control module determines whether the current first safety threshold and second safety threshold are reasonable based on the laser's slope efficiency and the second switch's on-resistance at the current temperature.

[0052] When the judgment is unreasonable, a reasonable first safety threshold and a reasonable second safety threshold are calculated based on the laser slope efficiency at the current temperature and the on-resistance of the second switch, and the current first safety threshold and the second safety threshold are changed.

[0053] The pulse detection system and method provided by this invention have the following advantages:

[0054] This invention provides a method for simultaneously detecting the average power and peak power of a laser in a pulsed circuit, thereby improving the safety of the detection system. Attached Figure Description

[0055] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings.

[0056] Figure 1 This is a schematic diagram of the pulse detection system of Embodiment 1 provided by the present invention;

[0057] Figure 2 This is a schematic diagram of the pulse detection system of Embodiment 2 provided by the present invention;

[0058] Figure 3 This is a schematic diagram of the chopper circuit of the pulse detection system according to Embodiment 2 of the present invention;

[0059] Figure 4 This is a schematic diagram of the chopper circuit adjusting the level signal down to a safe threshold according to Embodiment 2 of the present invention;

[0060] Figure 5 This is a schematic diagram of the pulse detection system of Embodiment 3 provided by the present invention;

[0061] Figure 6 This is a schematic diagram of the pulse detection system of Embodiment 4 provided by the present invention;

[0062] Figure 7 This is a schematic diagram of the comparator in Embodiment 4 provided by the present invention;

[0063] Figure 8 This is a schematic diagram of the pulse detection method of Embodiment 5 provided by the present invention;

[0064] Figure 9 This is a schematic flowchart of the pulse detection method according to Embodiment 6 of the present invention;

[0065] Figure 10 This is a schematic flowchart of the temperature detection and safety threshold adjustment of the pulse detection method in Embodiment 7 of the present invention;

[0066] Figure 11 This is a schematic diagram of the control module of the pulse detection system of Embodiment 8 provided by the present invention. Detailed Implementation

[0067] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that the invention will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore repeated descriptions of them will be omitted. The words “or” and “or” in the specification may mean “and” or “or”.

[0068] This invention provides a pulse detection system that combines a peak power detection circuit and an average power detection circuit to detect two failure modes: (1) the system detects failure modes where the radiation of any single pulse in a pulse sequence exceeds the maximum radiation of a single pulse; and (2) the system detects failure modes where the average radiation of multiple pulses over any duration T exceeds the maximum radiation of a single pulse during continuous irradiation time T within that pulse sequence. When the laser emission energy of the pulse detection system is detected to be too high, the laser is promptly shut off to protect the human eye. The invention will be explained and described in detail below with reference to specific embodiments.

[0069] Example 1

[0070] like Figure 1 As shown, the pulse detection system provided by the present invention includes: a laser module M100 for emitting laser light, comprising a laser M120, a first switch M110, and a second switch M130; an average power detection module M200 for detecting the average voltage of multiple pulses and generating a first detection result; a peak power detection module M300 for detecting the peak voltage of a single pulse and generating a second detection result; a control module M400 for processing data based on the first and second detection results and outputting a first pulse sequence signal and a control signal, wherein the control signal controls the on / off state of the first switch M110 and the first pulse sequence signal controls the on / off state of the second switch M130; a power supply module M500 for providing power for the operation of the pulse detection system; and a temperature detection module M600, electrically connected to the control module M400, for detecting temperature changes around the laser M120 and outputting the detection result to the control module M400, wherein the temperature detection module M600 includes a thermistor or a temperature sensor chip. The first switch M110 is located between the power module M500 and the first end of the laser M120, and the second switch M130 is located at the second end of the laser M120. The first end of the laser M120 is the anode end of the laser M120, and the second end of the laser M120 is the cathode end of the laser M120.

[0071] Furthermore, the pulse detection system also includes a current sensor located between the power supply module M500 and the average power detection module M200. The current sensor detects changes in current within the circuit and converts these changes into voltage changes, thus converting the DC level emitted by the power supply module M500 into a pulse signal for average power detection. In this embodiment, the current sensor is a current-sensing resistor. The laser module M100 also includes an energy storage capacitor located between the current-sensing resistor and the first switch M110. This capacitor stores charge to compensate for the instant the laser module M100 is turned on, ensuring timely illumination of the laser M120. The energy storage capacitor is located between the power supply module M500 and the laser M120. The first switch M110 includes a field-effect transistor, a transistor, or a digital gate circuit, etc. Furthermore, the pulse detection system also includes a driving circuit M700, which is connected to the second switch M130. The driving circuit M700 is used to boost the voltage and current of the first pulse sequence signal to control the rapid switching on and off of the second switch M130. The driving circuit M700 includes a data digital buffer chip or a transistor driving chip. The second switch M130 is a high-frequency switching transistor, including an N-MOS transistor, a GaN transistor, a power transistor, or an insulated-gate bipolar transistor, etc. Furthermore, the control module M400 includes a counter unit. When the peak voltage of a single pulse exceeds a preset voltage threshold based on the second detection result, the control module M400 controls the counter unit to start counting, and when the count value of the counter unit exceeds a preset quantity threshold, it controls the first switch M110 to open. By counting failed pulses using the counter unit, the phenomenon of the laser being mistakenly shut down due to brief pulse waveform jumps caused by external interference can be avoided, reducing misjudgments. Specifically, the average power detection module M200 is located between the current sensing resistor and the control module M400, the peak power detection module M300 is located between the second switch M130 and the control module M400, and the drive circuit is located between the control module M400 and the second switch M130.

[0072] In this embodiment, the second switch M130 is an N-MOS transistor. The N-MOS transistor has three pins: drain (D), gate (G), and source (S). The conduction and cutoff of the MOS transistor are determined by the gate voltage (V). GS The voltage controls the gate-source voltage. When the potential difference between the gate and source exceeds the threshold voltage for the MOSFET to turn on, the drain potential V... D Almost the same as the source potential V S When the gate potential V is equal, the circuit is on; conversely, if the gate potential V is equal, the circuit is not on. D With source potential VS When the potential difference between the drain and source is less than the threshold voltage for the MOSFET to turn on, it indicates that the resistance between the drain and source is large and almost no current flows. At this time, the laser M120 is equivalent to an open-circuit circuit; the circuit is disconnected, and the input first pulse sequence thus turns the entire circuit on and off. In other words, when the pulse level is high, i.e., V... GS When the voltage exceeds the threshold voltage required to turn on the MOSFET, the circuit is activated and the laser lights up; when the pulse level is low, i.e., V... GS If the voltage is less than the threshold voltage required to turn on the MOSFET, the circuit is disconnected, the laser is not lit, and it will not emit laser light.

[0073] The working principle of the pulse detection system in this embodiment is as follows:

[0074] The power module M500 provides power to the entire circuit, namely the laser module M100, the average power module M200, the peak power detection module M300, the control module M400, the temperature detection module M600, and the drive circuit M700.

[0075] When the power module M500 is powered on, the laser module M100, the control module M400, the average power module M200, and the peak power module M300 start to work normally. However, at this time, the first switch M110 is in the off state. Therefore, no current is passed into the laser module M100, and the laser M120 is not lit.

[0076] When the first switch M110 receives the first control signal output by the control module M400, it is turned on. Simultaneously, after receiving the first pulse sequence signal output by the control module M400, the drive circuit M700 increases the voltage and current of the pulse signal, controlling the rapid opening and closing of the second switch M130, i.e., controlling the rapid on and off of the second switch M130. When the second switch M130 is turned on, the circuit in the laser module M100 is conductive, and the laser M120 is lit. When the second switch M130 is turned off, the circuit in the laser module M100 is disconnected and not flowing, and the laser M120 is off and not lit. Based on the first pulse sequence signal, the laser M120 intermittently lights up and turns off.

[0077] When the laser M120 is working, the average power detection module M200 and the peak power detection module M300 detect the pulse peak voltage and pulse average voltage and transmit the detection results to the control module M400.

[0078] The control module M400 determines whether the laser M120 exceeds the safety threshold based on the detection results.

[0079] If the control module M400 determines that the safety threshold is exceeded, it outputs a corresponding control signal to the first switch M110 to disconnect, turning off the laser M120. Simultaneously, it adjusts the first pulse sequence to stabilize the operating voltage of the laser M120 output by the power module M500 below the safety threshold. Then, it outputs a control signal to turn the first switch M110 back on, and the laser M120 returns to normal operation. By monitoring the average and peak power of the pulse circuit containing the laser in real time, the safety of the pulse detection system is improved, preventing excessive laser energy from causing harm to the human body.

[0080] The pulse detection system in this embodiment also includes a temperature detection module M600, placed around the laser M120, for detecting the temperature around the laser M120. When the pulse detection system operates for a long time, the temperature of the power supply circuit board will rise with the increase of operating time. The temperature detector M600 detects the temperature around the circuit board and transmits the temperature detection result to the control module M400. The control module M400 determines whether the safety threshold setting at the current temperature is reasonable. If it is not reasonable, it resets the reasonable safety threshold to ensure that the laser is not misjudged when the temperature rises, thus preventing it from being turned off when it is operating within the normal power range and failing to work properly, thereby improving the accuracy of the pulse detection system.

[0081] Example 2

[0082] like Figure 2 As shown, the pulse detection system in this embodiment differs from that in Embodiment 1 in that a chopper circuit M800 is provided between the power supply module M500 and the laser M120. The chopper circuit M800 is used to adjust the voltage output by the power supply module M100, reducing the voltage output by the power supply module M500 to below a safe threshold voltage. Specifically, the control module M400 is used to generate a second pulse sequence signal based on the first detection result and the second detection result. This second pulse sequence signal is used to control the operating state of the chopper circuit M800. A schematic diagram of the chopper circuit is shown below. Figure 3 As shown, the chopper circuit M800 includes a high-frequency switching transistor and a capacitor. Figure 3 The high-frequency switching transistor mentioned above is a MOS transistor, and the working principle of the chopper circuit M800 is as follows:

[0083] When the peak power module M300 detects that the peak voltage exceeds the second safety threshold, that is, the power supply voltage of the power module M500 is too high, the control module M400 outputs a second pulse sequence to control the rapid opening and closing of the MOS transistor in the chopper circuit M800, thereby reducing the duty cycle of the peak level and filtering out some level signals.

[0084] Capacitor C performs filtering and integration on the processed level signal, such as... Figure 4 As shown, the principle is to make the shaded part of the pulse sequence the same as the shaded part of the waveform after passing through the capacitor, thereby stabilizing the voltage output by the power module M500 below the second safety threshold, thereby reducing the power supply voltage of the power module M500.

[0085] When the voltage output by the power module M500 stabilizes below the second safety threshold, the control module M400 will output a control signal to turn on the first switch M110, and the laser M120 will light up again and resume normal operation.

[0086] It should be noted that there are generally two reasons for laser failure: 1. Failure of electronic components in the power module, i.e., a sudden increase in the output voltage of the power module; 2. Instability of the first pulse sequence, such as a sudden increase in the duty cycle. By setting up a chopper circuit, the power failure problem caused by the failure of electronic components in the circuit can be solved.

[0087] Example 3

[0088] like Figure 5As shown, the average power detection module M200 includes an RC circuit and a first part of an analog-to-digital converter circuit M910; the peak power detection module M300 includes a second part of the analog-to-digital converter circuit M910; the analog-to-digital converter circuit M910 is electrically connected to the control module M400. Specifically, the portion of the analog-to-digital converter circuit M910 connected to its first input terminal is considered the first part of the circuit; the portion of the analog-to-digital converter circuit M910 connected to its second input terminal is considered the second part. Specifically, in the average power detection module M200, an RC filter circuit is first used to convert the pulse signal output by the current sensor into a DC level signal, which is then connected to the first input terminal of the analog-to-digital converter M910. The DC level signal is then converted into digital information by the analog-to-digital converter M910, and the converted digital information is transmitted to the control module M400. In the peak power detection module M300, the second input terminal of the analog-to-digital converter is connected to the drain of the second switch M130, making the input potential of the analog-to-digital converter the same as the drain potential of the second switch. Generally, after the second switch M130 is turned on, the on-resistance R of the second switch is... DS There is a voltage drop, that is, there is a potential difference between the drain (D) and the source (S), and the on-resistance R obtained by the analog-to-digital converter circuit M910 is... DS The voltage drop is converted by the analog-to-digital converter M910, and the conversion result is transmitted to the control module M400. The control module M400 reads the digital information after analog-to-digital conversion and compares it with the digital value corresponding to the threshold voltage of the corresponding detection module programmed in the program, to determine whether the laser M130 is operating within the safe range. When a temperature detection module is added to the pulse detection circuit in this embodiment, the real-time adjustment of the safe threshold voltage at different temperatures is also implemented by programming within the control module.

[0089] The following example illustrates the working principle of an analog-to-digital converter (ADC): When the peak detection circuit detects a peak voltage, such as 4V, this result is input to the ADC. The ADC converts the 4V analog voltage into the corresponding digital value 0x0333 and outputs it to the control module. The control module internally sets the safety threshold for the peak voltage to 0x0399, corresponding to 4.5V. The control module is programmed to correlate the numerical and analog values: 0x0333 -> 4V, 0x0399 -> 4.5V. By comparing the digital values, it can be determined whether the peak voltage exceeds the safety threshold. When the safety threshold voltage needs to be modified, the corresponding digital value can be directly modified within the program, without the need for an external power supply.

[0090] Example 4

[0091] like Figure 6 As shown, the average power detection module M200 includes an RC circuit and a first comparator M921, and the peak power detection module M300 includes a second comparator M922. The control module M400 is electrically connected to the first comparator M921 and the second comparator M922, respectively. Specifically, the average power detection module M200 converts the pulse signal into a DC level signal through an RC filter circuit, and connects it to the positive input terminal of the first comparator M921. The negative input terminal of the first comparator M921 is connected to a first safety threshold voltage. The positive input terminal of the second comparator M922 is connected to the drain of the second switch, i.e., the voltage after the second switch M130 is turned on. The negative input terminal of the second comparator M922 is connected to a second safety threshold voltage. The positive input terminals of the comparators receive the average voltage and the peak voltage, and the negative input terminals receive the first safety threshold voltage and the second safety threshold voltage, i.e., the safety threshold voltages for the average voltage and the peak voltage, respectively. The safety threshold voltages are provided by the power supply module and can be controlled by the control module to change the threshold voltages in real time. The comparator works as follows: it outputs a result of "1" or "0" to the control module, which then determines whether the laser is operating within a safe range based on the input "1" or "0" signal. The control module can distinguish between high and low level signals; for example, a comparator output greater than 1.8V is considered a high level ("1"), and a value less than 0.3V is considered a low level ("0").

[0092] like Figure 7 As shown, the comparator has a positive input terminal V+ and a negative input terminal V-. When the V+ input voltage is greater than the V- input voltage, the output terminal Vout outputs a high level, which is the power supply voltage VCC of the comparator chip. When the V+ input voltage is less than the V- input voltage, the output is a low level, i.e., 0V. As for the identification of the digital quantity "1" or "0", the output terminal of the comparator is connected to the control module. For the control module, when the input voltage is greater than a certain value (such as 2V), it is identified as "1", and when the input voltage is less than a certain value (such as "0.7V"), it is identified as "0".

[0093] The following example will further illustrate the working principle of a comparator. For instance, if the comparator's supply voltage is 3.3V, the peak voltage at its positive input terminal V+ is 4V, and the second safety threshold voltage at its negative input terminal V- is 4.5V, then by comparing 4V and 4.5V, the comparator outputs 0V (less than the 0.7V low-level voltage recognized by the control module), i.e., a digital signal "0," which is transmitted to the control module. Upon recognizing "0," the control module determines that the voltage is within the safe range. Conversely, if the peak voltage at the positive input terminal V+ is 5V, and the second safety threshold voltage at the negative input terminal V- is 4.5V, then by comparing 5V and 4.5V, the comparator outputs a supply voltage of 3.3V, which is greater than the 2V high-level voltage recognized by the control module, i.e., a digital signal "1," which is transmitted to the control module. Upon recognizing "1," the control module determines that the peak voltage exceeds the safe range. Subsequently, the control module can output a first pulse sequence signal with a smaller pulse width to adjust the on / off state of the second switch, thereby reducing the peak voltage.

[0094] Example 5

[0095] like Figure 8 As shown, this embodiment of the invention provides a pulse detection method, which includes the following steps:

[0096] S100: The laser module emits a laser beam;

[0097] S200: The average power detection module detects the average voltage of multiple pulses and generates a first detection result;

[0098] S300: The peak power detection module detects the peak voltage of a single pulse and generates a second detection result;

[0099] S400: The control module processes the data based on the first detection result and the second detection result, and outputs a first pulse sequence signal and a control signal. The control signal is used to control the on / off state of the first switch, and the first pulse sequence signal is used to control the on / off state of the second switch.

[0100] Example 6

[0101] Figure 9 A flowchart of a pulse detection method according to one embodiment of the present invention is provided. Figure 9 It can be seen that the pulse detection method includes the following steps:

[0102] The power module supplies power to the detection system. When the power module is powered on, the detection system starts to work normally. The control module (MCU) outputs a first pulse sequence signal and a circuit signal indicating that the first switch is turned off and on, which lights up the laser and makes it emit laser light. At the same time, the average power detection module and the peak power detection module detect the average power and peak power of the entire circuit, respectively. The average power detection module generates a first detection result and sends it to the control module, and the peak power detection module generates a second detection result and sends it to the control module.

[0103] The control module reads the information of the first detection result and determines whether the average voltage of the laser in multiple pulses exceeds the first safety threshold based on the information of the first detection result; the control module reads the information of the second detection result and determines whether the peak voltage in the current pulse exceeds the second safety threshold based on the information of the second detection result; the first safety threshold is the maximum voltage value that the average voltage in multiple pulses can allow to work, and the second safety threshold is the maximum voltage value that the peak voltage in the current pulse can allow to work.

[0104] When it is determined that the first detection result and the second detection result do not exceed the corresponding safety threshold, the laser remains in normal working condition;

[0105] When it is determined that the first detection result exceeds the first safety threshold and / or the second detection result exceeds the second safety threshold;

[0106] The control module outputs a first control signal to disconnect the first switch, and the laser is turned off.

[0107] When it is determined that the peak voltage within the current pulse exceeds the second safety threshold, the method further includes the following steps:

[0108] The counter of the control module starts counting;

[0109] Once the counter count value does not exceed the safety pulse count setting value, the laser continues to maintain normal operation.

[0110] When the counter count exceeds the safety pulse count setting, the control module outputs the first control signal, and the laser is turned off.

[0111] After the laser is turned off, the method further includes the following steps:

[0112] The controller module adjusts the voltage of the first pulse sequence, that is, reduces the duty cycle of the first pulse sequence and reduces the peak voltage within a single pulse period.

[0113] The peak power detection module and the average power detection module continue to detect the peak power and average power of the circuit;

[0114] When the first detection result generated by the average power module is less than the first safety threshold and the second detection result generated by the peak power detection module is less than the second safety threshold, the control module outputs a second control signal.

[0115] After receiving the second control signal, the first switch turns off and the circuit of the laser module is turned on, and the laser emits laser light normally.

[0116] When the detection system also includes a chopper circuit, after the laser is turned off, the following steps are also included:

[0117] The control module outputs a second pulse sequence signal;

[0118] The chopper circuit receives the second pulse sequence signal to adjust the input voltage of the power module, that is, to adjust and reduce the input voltage of the power supply.

[0119] The peak power detection module and the average power detection module continue to detect the peak power and average power of the circuit;

[0120] When the first detection result generated by the average power detection module is less than the first safety threshold and the second detection result generated by the peak power detection module is less than the second safety threshold, the control module outputs a second control signal.

[0121] After receiving the second control signal, the first switch turns off and turns on, the circuit of the laser module is turned on, and the laser emits laser normally.

[0122] When the laser fails to operate, if the cause is found to be a failure of the average power or peak power in the circuit, the voltage can be adjusted by filtering the power signal through a chopper circuit, or the voltage can be adjusted by adjusting the pulse signal width through the control module, so that the laser can work normally.

[0123] By using the pulse detection method described above, the average power and peak power of the pulse circuit can be detected simultaneously, ensuring that the laser operates within a safe range and improving the safety of laser operation.

[0124] Example 7

[0125] This embodiment provides a pulse detection system with a temperature detection module. For example... Figure 10 As shown, when the pulse detection system is equipped with a temperature detection module, the pulse detection method further includes the following steps:

[0126] The temperature detection module detects the temperature of the laser and the circuit board around it, and sends the detection results to the control module.

[0127] After reading the temperature, the control module determines whether the current first safety threshold and second safety threshold are reasonable based on the laser's slope efficiency and the second switch's on-resistance at the current temperature.

[0128] When the judgment is unreasonable, a reasonable first safety threshold and a reasonable second safety threshold are calculated based on the laser slope efficiency at the current temperature and the on-resistance of the second switch, and the current first safety threshold and the second safety threshold are changed.

[0129] Specifically, the temperature detection module operates on the following principle: When the laser is lit, the temperature of the circuit board responsible for power supply rises as the lighting time and ambient temperature increase. As the circuit board temperature rises, the laser's slope efficiency decreases, requiring a larger current to emit the same power laser light. The internal resistance of the second switch also increases with temperature. As the power output current and the internal resistance of the second switch increase, according to U=IR, the resistance across the second voltage also increases. Therefore, the set safety threshold no longer meets the requirements at the current temperature. Consequently, the control module adjusts the safety threshold at the current temperature: when the temperature rises, the safety threshold voltage is increased, and vice versa, achieving high-precision laser detection.

[0130] The following example illustrates the principle of threshold voltage adjustment in the temperature detection module. For instance, when the circuit board temperature is 25℃, based on the laser's slope efficiency of 2W / A, an 8W laser requires 4A of current from the power supply. If the on-resistance of the second switch is 100mΩ, the voltage across the second switch when the laser is operating is 0.4V. If the peak power module's safety threshold is 0.5V, then 0.4V < 0.5V, meaning the laser operates within a safe range and emits light normally. If the circuit board temperature is 85℃, the laser's slope efficiency drops to 1.5W / A, and the 8W laser requires 5.4A of current from the power supply. At this point, the on-resistance of the second switch is 150mΩ, and the voltage across the second switch is 0.81V. If the safety threshold voltage of 0.5V from 25℃ is still used, an alarm will sound and the laser will stop emitting light, even though the laser is still operating within a safe power range. Therefore, by adding a temperature detection module, the system can detect in real time whether the safety threshold is within the safe range. When the temperature changes, a reasonable safety threshold will be set according to the current temperature to reduce false alarms that the laser is not working within the reasonable range. The pulse detection system achieves the goal of high-precision detection.

[0131] Example 8

[0132] like Figure 11 As shown, this embodiment of the invention provides a control module in a pulse detection system. The control module includes: a first functional unit M410, a second functional unit M420, a third functional unit M430, a fourth functional unit M440, and a fifth functional unit M450. The first functional unit M410 is used to output the first pulse sequence and, based on the detection results of the peak power and average power, adjust the duty cycle of the first pulse sequence in real time to ensure that the laser operates within a safe range. For example, when the laser emits laser light for too long, the first functional unit M410 can reduce the duty cycle of the first pulse sequence signal to ensure that the laser operates within a safe range.

[0133] The second functional unit M420 is used to output a control signal for the first switch to turn the laser on or off. For example, after the power module powers on the entire pulse detection system, when the laser is operating within a safe threshold, the second functional unit M420 outputs a high level to control the first switch to remain closed, ensuring that the laser is lit. If, during the laser's lighting process, the monitoring results of the peak power and average power exceed the safe threshold, the second functional unit M420 outputs a low level to control the first switch to open, and the laser stops emitting light.

[0134] The third functional unit M430, when detecting that the peak power and / or the average power exceed the safety threshold, outputs a second pulse sequence to the chopper circuit to reduce the voltage output by the power module to within the safety threshold. When the peak level output by the power module drops below the safety threshold, the laser can safely emit light. When the laser is operating within the safety threshold, the third functional unit M430 does not output the second pulse sequence. If, during the laser's illumination process, the peak power and average power detection results exceed the safety threshold, the third functional unit M430 outputs a second pulse sequence to the chopper circuit module to control its operation, reducing the peak level output by the power module to within the safety threshold, thereby ensuring the laser emits light safely.

[0135] The fourth functional unit M440 is used to read the temperature around the laser and output a power control signal to output a first safety threshold for controlling the average power detection module and a second safety threshold for controlling the peak power detection module. The fourth functional unit M440 is installed in a detection system with a comparator. When the laser is working normally, the temperature detection module detects a rise in the temperature around the circuit board and outputs the detection result to the control module. After the control module reads the temperature, the fourth functional unit M440 outputs a power control signal to control the power module to output a reasonable first safety threshold and a second safety threshold at the current temperature.

[0136] The fifth functional unit M450 is used to adjust the first and second safety thresholds in real time, and compares the output result of the detection with the corresponding safety threshold. The fifth functional unit M450 is installed in a detection system containing analog-to-digital conversion. When the laser is working normally, the temperature detection module outputs the detected temperature result to the control module. After reading the temperature, if the control module determines that the safety threshold at the current temperature is not within a reasonable range, the fifth control unit M450 adjusts the safety threshold internally to set it to a reasonable value at the current temperature. The total input of the control module is from the power supply module.

[0137] The pulse detection system and method provided by this invention have the following advantages:

[0138] This invention provides a pulse detection system that can simultaneously detect the average power and peak power of a laser in a pulse circuit, meeting the detection requirements of international safety laser standards and improving the safety of the pulse detection system. The addition of a temperature detection module allows for real-time adjustment of a suitable safety threshold based on the ambient temperature around the laser, achieving high-precision detection.

[0139] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A pulse detection system, characterized in that, include: A laser module for emitting laser light includes a laser, a first switch, and a second switch. The average power detection module is used to detect the average voltage of multiple pulses and generate a first detection result. The peak power detection module is used to detect the peak voltage of a single pulse and generate a second detection result; The control module is used to process data based on the first detection result and / or the second detection result and output corresponding signals; The power module is used to provide electrical energy for the operation of the detection system; The first switch is located between the power module and the first end of the laser, and the second switch is located at the second end of the laser; The corresponding signal includes a first pulse sequence signal and a control signal, wherein the control signal is used to control the on / off state of the first switch, and the first pulse sequence signal is used to control the on / off state of the second switch; or... The corresponding signals include a first pulse sequence signal, a second pulse sequence signal, and a control signal. The control signal is used to control the on / off state of the first switch, and the first pulse sequence signal is used to control the on / off state of the second switch. The second pulse sequence signal is used to control the working state of the chopper circuit; the chopper circuit is used to adjust the voltage output by the power module to a level lower than the safety threshold voltage.

2. The pulse detection system according to claim 1, characterized in that, The control module includes a first functional unit and a second functional unit. The first functional unit is used to output the first pulse sequence and adjust the duty cycle of the first pulse sequence according to the detection results of the peak power detection module and the average power detection module, so that the laser operates within a safe range. The second functional unit is used to output the control signal of the first switch to turn the laser on or off.

3. The pulse detection system according to claim 1, characterized in that, It also includes a temperature detection module, which is electrically connected to the control module and is used to detect temperature changes around the laser and output the detection results to the control module; The control module also includes a fourth functional unit, which is used to read the temperature around the laser and output a power control signal to output a first safety threshold for controlling the average power detection module and a second safety threshold for controlling the peak power detection module.

4. The pulse detection system according to claim 3, characterized in that, The temperature detection module includes a thermistor or a temperature sensor chip.

5. The pulse detection system according to claim 1, characterized in that, It also includes a current sensor located between the power supply module and the average power detection module. The current sensor is used to detect changes in current in the circuit and convert the current change into a voltage change, so that the DC level emitted by the power supply module is converted into a pulse signal for the purpose of detecting the average power.

6. The pulse detection system according to claim 5, characterized in that, The current sensor is a current-sensing resistor.

7. The pulse detection system according to claim 1, characterized in that, The laser module includes an energy storage capacitor for storing charge to compensate for the charge at the moment the circuit of the laser module is turned on, so as to light up the laser in time.

8. The pulse detection system according to claim 1, characterized in that, The control module further includes a third functional unit, which outputs a second pulse sequence signal when the peak power and / or average power exceed the safety threshold, so that the voltage output by the power module drops to within the safety threshold.

9. The pulse detection system according to claim 1, characterized in that, The first switch includes a field-effect transistor, a transistor, or a digital gate circuit.

10. The pulse detection system according to claim 1, characterized in that, It also includes a driving circuit, which is connected to the second switch. The driving circuit is used to increase the voltage and current of the first pulse sequence signal to control the rapid switching on and off of the second switch. The driving circuit includes a digital buffer chip or a transistor driver chip.

11. The pulse detection system according to claim 1, characterized in that, The average power detection module and the peak power detection module are each electrically connected to the control module via an analog-to-digital conversion circuit. The control module further includes a fifth functional unit, which is used to adjust the first safety threshold and the second safety threshold in real time, and compare the detection output with the corresponding safety threshold.

12. The pulse detection system according to claim 11, characterized in that, The average power detection module includes a first part of an RC circuit and an analog-to-digital conversion circuit, and the peak power detection module includes a second part of an analog-to-digital conversion circuit. The first safety threshold and the second safety threshold are set in the control module.

13. The pulse detection system according to claim 1, characterized in that, The average power detection module and the peak power detection module are each electrically connected to the control module through a comparator circuit.

14. The pulse detection system according to claim 13, characterized in that, The average power detection module includes an RC circuit and a first comparator. The positive input terminal of the first comparator is connected to the output terminal of the RC circuit, and the negative input terminal of the first comparator is connected to a first safety threshold.

15. The pulse detection system according to claim 13, characterized in that, The peak power detection module includes a second comparator, the positive input terminal of which is connected to the second switch, and the negative input terminal of which is connected to a second safety threshold.

16. The pulse detection system according to claim 1, characterized in that, The control module includes a counter unit. When the peak voltage of a single pulse exceeds a preset voltage threshold based on the second detection result, the control module controls the counter unit to start counting. When the count value of the counter unit is greater than a preset quantity threshold, the control module controls the first switch to open.

17. The pulse detection system according to claim 1, characterized in that, The second switch is a high-frequency switching transistor, including an N-MOS transistor, a GaN transistor, a power transistor, or an insulated-gate bipolar transistor.

18. A pulse detection method, characterized in that, The pulse detection system according to any one of claims 1-17, the method comprising the following steps: The laser module emits laser light; The average power detection module detects the average voltage of multiple pulses and generates a first detection result; The peak power detection module detects the peak voltage of a single pulse and generates a second detection result; The control module processes the data based on the first detection result and / or the second detection result, and outputs a corresponding signal. The corresponding signal includes a first pulse sequence signal and a control signal; the control signal is used to control the on / off state of the first switch, and the first pulse sequence signal is used to control the on / off state of the second switch; or... The corresponding signals include a first pulse sequence signal, a second pulse sequence signal, and a control signal. The control signal is used to control the on / off state of the first switch, and the first pulse sequence signal is used to control the on / off state of the second switch. The second pulse sequence signal is used to control the working state of the chopper circuit; the chopper circuit is used to adjust the voltage output by the power module to a level lower than the safety threshold voltage.

19. The pulse detection method according to claim 18, characterized in that, The control module receives the first detection result and the second detection result and processes the data. The method includes the following steps: The control module determines, based on the second detection result, whether the peak voltage in the current pulse exceeds the second safety threshold. The control module determines, based on the first detection result, whether the average voltage of the laser in multiple pulses exceeds a first safety threshold. When it is determined that the first detection result exceeds the first safety threshold and / or the second detection result exceeds the second safety threshold; The control module outputs a first control signal to disconnect the first switch, and the laser is turned off.

20. The pulse detection method according to claim 19, characterized in that, When it is determined that the peak voltage within the current pulse exceeds the first safety threshold, the method includes the following steps: The counter of the control module starts counting; When the counter count exceeds the safety pulse count setting, the control module outputs the first control signal, and the laser is turned off.

21. The pulse detection method according to claim 19, characterized in that, After the laser is turned off, the method further includes the following steps: The control module adjusts the voltage of the first pulse sequence; When it is determined that the first detection result is less than the first safety threshold and the second detection result is less than the second safety threshold, the control module outputs a second control signal; After receiving the second control signal, the first switch turns off, the circuit of the laser module is turned on, and the laser emits laser light normally.

22. The pulse detection method according to claim 19, characterized in that, The system also includes a chopper circuit, and after the laser is turned off, the following steps are also included: The control module outputs a second pulse sequence signal; The chopper circuit receives the second pulse sequence signal to adjust the input voltage of the power module; When it is determined that the first detection result is less than the first safety threshold and the second detection result is less than the second safety threshold, the control module outputs a second control signal; After receiving the second control signal, the first switch turns off and conducts, the circuit of the laser module is turned on, and the laser emits laser light normally.

23. The pulse detection method according to claim 18, characterized in that, The system further includes a temperature detection module, and the method further includes the following steps: The temperature detection module detects the temperature of the laser and the circuit board around it, and sends the detection results to the control module. After reading the temperature, the control module determines whether the current first safety threshold and second safety threshold are reasonable based on the laser's slope efficiency and the second switch's on-resistance at the current temperature. When the judgment is unreasonable, a reasonable first safety threshold and a reasonable second safety threshold are calculated based on the laser slope efficiency at the current temperature and the on-resistance of the second switch, and the current first safety threshold and the second safety threshold are changed.

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