A driving control method for a vehicle lamp control circuit

Abstract

This invention discloses a drive control method for vehicle lighting control circuits, relating to the field of vehicle lighting drive technology. The drive control method for vehicle lighting control circuits includes: acquiring a preset drive current; collecting electrical signals from each input port to identify the currently requested main LED group as the target LED group; selecting the maximum value of the drive current in the target LED group as the calibration peak current; calculating the calibration PWM duty cycle of each target LED group; determining whether all calibration PWM duty cycles are less than or equal to a preset maximum duty cycle; if yes, marking the calibration PWM duty cycle as the target PWM duty cycle; if no, correcting the calibration peak current based on the maximum duty cycle and recalculating each calibration PWM duty cycle to generate a PWM control signal; and outputting the calibration peak current to control the on / off state of the main switching circuit. Using this invention, the PWM duty cycle and switching sequence of each lamp group can be coordinated, suppressing output voltage fluctuations.

Description

Technical Field

[0001] This invention relates to the field of vehicle lighting drive technology, and in particular to a drive control method for vehicle lighting control circuits. Background Technology

[0002] Existing automotive lighting driver solutions employ an independent driver architecture: each LED light group is equipped with an independent DC-DC converter circuit and switching control module. This architecture results in high material costs, a large PCB footprint, and the independent operation of multiple discrete switching devices makes it difficult to synchronize switching frequencies, increases the probability of electromagnetic interference, and reduces heat dissipation efficiency.

[0003] Another approach uses a series bypass architecture: multiple LED groups are connected in series at the output of a single DC-DC converter circuit. The switching on and off is controlled by the main switching circuits at both ends of each LED group, achieving multiplexing of multiple LED groups from a single current source. While this architecture reduces the number of DC chips, the existing control method has the following drawbacks: the PWM duty cycle of each main switching circuit is set independently, lacking a coordination mechanism, making it difficult to match the peak current on the series path with the actual needs of each LED group, and failing to take into account the target current of different LED groups; furthermore, when all duty cycles are close to 100%, there is a lack of switching gaps within a PWM cycle, and the lack of on / off timing coordination when multiple LED groups are switched together leads to drastic fluctuations in output voltage, generating current surges and electromagnetic interference.

[0004] Therefore, it is urgent to design a drive control method for vehicle lighting control circuits to solve the above problems. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a driving control method for vehicle lighting control circuits, which can coordinate the PWM duty cycle and switching timing of each lamp group and suppress output voltage fluctuations.

[0006] To address the aforementioned technical problems, this invention provides a driving control method for a vehicle lighting control circuit. The vehicle lighting control circuit includes a port module and a main lighting module. The main lighting module includes a main voltage conversion circuit, a main switching unit, and a main LED unit. The main switching unit includes several main switching circuits, and the main LED unit includes several main LED groups connected in series. The port module includes input ports and main output ports corresponding one-to-one with each of the main LED groups. One end of the main voltage conversion circuit is connected to each of the main output ports, and the other end of the main voltage conversion circuit is connected to each of the main LED groups through the main switching unit. The driving control method includes: acquiring a preset driving current in each of the main LED groups; collecting electrical signals from each input port to identify the currently requested main LED group based on the electrical signals, and designating the main LED group as the target LED group; and selecting the target LED group with the largest driving current. The value is used as the calibration peak current; the calibration PWM duty cycle of each target LED group is calculated, where the calibration PWM duty cycle is the ratio of the drive current of the target LED group to the calibration peak current; it is determined whether all the calibration PWM duty cycles are less than or equal to the preset maximum duty cycle. If yes, the calibration PWM duty cycle is marked as the target PWM duty cycle; if no, the calibration peak current is corrected according to the maximum duty cycle, and the calibration PWM duty cycle of each target LED group is recalculated until all the calibration PWM duty cycles are less than or equal to the maximum duty cycle; a PWM control signal is generated according to the target PWM duty cycle, and the PWM control signal outputs of at least two target LED groups have a phase difference; the main voltage conversion circuit is driven to output the calibration peak current, and the on / off state of the main switching circuit is controlled according to the PWM control signal to adjust the working state of the target LED group.

[0007] As an improvement to the above scheme, the step of correcting the calibrated peak current based on the maximum duty cycle includes: according to the formula Correct the calibrated peak current; wherein, This is the corrected calibration peak current. The calibration peak current before correction. This represents the maximum duty cycle.

[0008] As an improvement to the above scheme, the maximum duty cycle is ≤95%.

[0009] As an improvement to the above scheme, the step of driving the PWM control signal output of at least two target LED groups to have a phase difference includes: determining the cut-in time and cut-out time of each target LED group according to the target PWM duty cycle of each target LED group; and staggering the PWM control signals of at least two target LED groups according to the cut-in time and cut-out time.

[0010] As an improvement to the above scheme, the step of staggering the PWM control signals driving at least two target LED groups includes: before the PWM control signal driving one target LED group is switched out of power supply, the PWM control signal driving the other target LED group is switched into power supply.

[0011] As an improvement to the above scheme, the electrical signal acquisition methods include AD sampling, CAN communication, LIN communication, level logic detection, or duty cycle detection.

[0012] As an improvement to the above solution, the vehicle lighting control circuit further includes a voltage acquisition module for acquiring the electrical signals of the input ports. The voltage acquisition module includes voltage divider and filter acquisition circuits corresponding to each of the input ports.

[0013] As an improvement to the above solution, it also includes: collecting the temperature signal of the main LED group, and when the temperature exceeds a preset threshold, adjusting the target PWM duty cycle of the corresponding target LED group or turning off the output.

[0014] As an improvement to the above solution, the vehicle lighting control circuit also includes an overheat protection module for collecting the temperature signal of the main LED lamp group, and the overheat protection module is connected to the main lighting module.

[0015] As an improvement to the above solution, the main switch unit includes a first switch circuit, a second switch circuit, and a third switch circuit; the main LED unit includes a first main LED group, a second main LED group, and a third main LED group connected in series; one end of the first switch circuit, one end of the second switch circuit, and one end of the first main LED group are all connected to the main voltage conversion circuit; the other end of the first switch circuit is connected to the other end of the first main LED group and one end of the second main LED group; the other end of the second switch circuit is connected to one end of the third switch circuit, the other end of the second main LED group, and one end of the third main LED group; and the other end of the third switch circuit is connected to the other end of the third main LED group and grounded.

[0016] As an improvement to the above solution, both the first and second switching circuits include a first resistor, a first diode, a first capacitor, a first MOSFET, a second capacitor, a third capacitor, a transistor, a second resistor, a fourth capacitor, a third resistor, and a fourth resistor; the source of the first MOSFET is connected to the negative terminal of the first diode; the drain of the first MOSFET is connected to one end of the second capacitor and grounded through the third capacitor; the gate of the first MOSFET is connected to the positive terminal of the first diode, the other end of the second capacitor, and the collector of the transistor; the first diode, the first resistor, and the first capacitor are connected in parallel; the emitter of the transistor is grounded through the fourth resistor; the base of the transistor is connected to the second resistor and grounded through the fourth capacitor; the fourth capacitor is connected in parallel with the third resistor.

[0017] As an improvement to the above solution, the third switching circuit includes a fifth resistor, a sixth resistor, a fifth capacitor, a second MOSFET, and a sixth capacitor; the gate of the second MOSFET is connected to the fifth resistor and grounded through the sixth resistor, and the sixth resistor and the sixth capacitor are connected in parallel; the drain of the second MOSFET is connected to the gate of the second MOSFET through the fifth capacitor; the source of the second MOSFET is grounded.

[0018] The beneficial effects of implementing this invention are as follows: This invention discloses a drive control method for vehicle lighting control circuits. This method dynamically selects the maximum drive current as the calibration peak current based on the currently requested combination of light groups to be illuminated; calculates the calibration PWM duty cycle according to the ratio of the drive current to the peak current for each light group; if the maximum duty cycle is exceeded, the peak current is corrected in reverse; a PWM signal is generated, and the PWM signals of at least two of the target LED light groups are made to have a phase difference; finally, the peak current is output by the drive voltage conversion circuit and the switching circuit is controlled. Using this drive control method for vehicle lighting control circuits, the PWM duty cycle and switching sequence of each light group can be coordinated.

[0019] Furthermore, the drive control method for vehicle lighting control circuits of the present invention also maintains a small fluctuation in the output voltage of the main voltage conversion circuit during load switching by staggering the cut-in / cut-out times, thus suppressing voltage surges and electromagnetic interference; enhances anti-interference capability and vehicle model adaptability through input signal acquisition methods and specific adjustment circuits; and improves system safety by introducing overheat protection, which automatically reduces the duty cycle or shuts down when the threshold is exceeded. Attached Figure Description

[0020] Figure 1 A circuit diagram of a first embodiment of a vehicle lighting control circuit; Figure 2 This is a flowchart of a first embodiment of a drive control method for a vehicle lighting control circuit according to the present invention; Figure 3 A circuit diagram of a second embodiment of a vehicle lighting control circuit; Figure 4 for Figure 3 Circuit diagram of voltage divider filter acquisition circuit; Figure 5 This is a schematic diagram of the PWM duty cycle distribution of the main LED light group without correction based on the maximum duty cycle. Figure 6 This is a schematic diagram of the PWM duty cycle distribution of the main LED light group after correction based on the maximum duty cycle. Figure 7 This is a schematic diagram of the distribution of the PWM duty cycle of the main LED light group after correction based on the maximum duty cycle and with a phase difference; Figure 8 This is a schematic diagram of another distribution of the PWM duty cycle of the main LED light group after correction based on the maximum duty cycle and with a phase difference; Figure 9 This is a flowchart of a second embodiment of a drive control method for a vehicle lighting control circuit according to the present invention; Figure 10 This is a circuit diagram of a third embodiment of a vehicle lighting control circuit; Figure 11 for Figure 10 Circuit diagram of the overheat protection module; Figure 12 This is a circuit diagram of a fourth embodiment of a vehicle lighting control circuit; Figure 13 for Figure 12 The main switch unit circuit diagram. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. It is hereby declared that the directional terms such as up, down, left, right, front, back, inside, and outside used in this text are based solely on the accompanying drawings and are not intended to specifically limit the invention.

[0022] like Figure 1 and Figure 2 As shown, Figure 1The diagram shows a circuit diagram of a first embodiment of a vehicle lighting control circuit in a driving control method for a vehicle lighting control circuit according to the present invention. The vehicle lighting control circuit includes a port module 100 and a main lighting module 200. The main lighting module 200 includes a main voltage conversion circuit 201, a main switch unit 202, and a main LED unit 203. The main switch unit 202 includes a plurality of main switch circuits. The main LED unit 203 includes a plurality of main LED groups connected in series. The port module 100 includes an input port 101 and a main output port 102 corresponding to each of the main LED groups. One end of the main voltage conversion circuit 201 is connected to the main output port 102, and the other end of the main voltage conversion circuit 201 is connected to the main LED groups through the main switch unit 202. Figure 2 The flowchart shown is a first embodiment of a drive control method for a vehicle lighting control circuit according to the present invention, including: S101, Obtain the preset driving current in each of the main LED groups; S102, collect the electrical signals of each input port respectively, so as to identify the main LED group that is currently requested to be lit according to the electrical signals, and use the main LED group as the target LED group; It should be noted that the electrical signal acquisition methods include AD sampling, CAN communication, LIN communication, level logic detection, or duty cycle detection. Preferably, the electrical signal acquisition method is AD sampling. like Figure 3 As shown, Figure 3 The diagram shows a second embodiment of the vehicle lighting control circuit. Correspondingly, the vehicle lighting control circuit also includes a voltage acquisition module 400 for acquiring the electrical signal of the input port 101. The voltage acquisition module 400 includes voltage divider and filter acquisition circuits corresponding to each of the input ports to improve signal anti-interference capability and acquisition accuracy.

[0023] like Figure 4 As shown, preferably, the voltage divider filter acquisition circuit includes a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, and a seventh capacitor C7. One end of the seventh resistor R7 is connected to the input port 101 (connected via the connection port "PWR"), and the other end is connected to one end of the eighth resistor R8 and one end of the ninth resistor R9. The other end of the eighth resistor R8 is connected to one end of the seventh capacitor C7 and connected to the microcontroller (via the connection port "AD_PWR"). The microcontroller is existing technology, and its principle will not be described in detail here. The other end of the ninth resistor R9 is connected to the other end of the seventh capacitor C7 and grounded.

[0024] S103, Select the maximum value of the driving current in the target LED group as the calibration peak current; S104, calculate the calibration PWM duty cycle of each target LED group respectively; It should be noted that the calibrated PWM duty cycle is the ratio of the driving current of the target LED group to the calibrated peak current; S105, determine whether all the calibrated PWM duty cycles are less than or equal to the preset maximum duty cycle. If the determination is yes, the calibrated PWM duty cycle is marked as the target PWM duty cycle. If the determination is negative, the calibrated peak current is corrected according to the maximum duty cycle and the calibrated PWM duty cycle of each target LED group is recalculated until all the calibrated PWM duty cycles are less than or equal to the maximum duty cycle. The step of correcting the calibrated peak current based on the maximum duty cycle includes: (1) According to the formula Correct the calibrated peak current; in, This is the corrected calibration peak current. The calibration peak current before correction. The maximum duty cycle is defined as follows. The maximum duty cycle can be selected according to actual needs; preferably, it is ≤95%, and more preferably 95%. By providing a simple and efficient reverse correction algorithm, the calibrated peak current is corrected using the maximum duty cycle, and the calibrated PWM duty cycle of each main LED group is recalculated. This adjusts the original PWM duty cycle of each main LED group while maintaining the average current of each group unchanged. The computational load is small, and it is easy to implement.

[0025] like Figures 5-7 As shown, it should be noted that, as an example, several main LED light groups connected in series are the low beam LED light group LB, the high beam LED light group HB, and the position LED light group PL; for example, when the driving current of the low beam LED light group LB is 0.9A, the driving current of the high beam LED light group HB is 0.81A, the driving current of the position LED light group PL is 0.7A, and the low beam LED light group LB, the high beam LED light group HB, and the position LED light group PL are all the target LED light groups: like Figure 5 As shown, the calibration peak current before correction The rated PWM duty cycle of the low beam LED light assembly LB is 0.9A, LB duty is 0.9 / 0.9=100%, the rated PWM duty cycle of the high beam LED light assembly HB is 0.81 / 0.9=90%, and the rated PWM duty cycle of the position LED light assembly PL is 0.7 / 0.9=78%. like Figure 6 As shown, in order to create the necessary time window for phase shift and complementary switching, while taking into account brightness accuracy, system reliability, and electromagnetic compatibility, it is necessary to follow the formula... The calibrated peak current was corrected to 0.9 / 95%≈0.947A. This is because the duty cycle was reduced from 100% to 95% (i.e., in one control cycle T, the low beam LED group LB was lit for T before correction, and 0.95T after correction). To prevent a decrease in brightness, the calibrated peak current needed to be increased accordingly. The calibrated PWM duty cycles were recalculated: the target PWM duty cycle for the low beam LED group LB was LB duty=95%, the target PWM duty cycle for the high beam LED group HB was HB duty=0.81 / 0.947≈85.5%, and the target PWM duty cycle for the position LED group PL was PL duty=0.7 / 0.947≈73.8%. S106, Generate a PWM control signal according to the target PWM duty cycle, and drive at least two target LED groups to output PWM control signals with a phase difference; like Figure 7 and Figure 8 As shown, each main LED group has a certain phase difference, so that during the interval time T dead The main LED lights inside remain lit.

[0026] Preferably, in step S106, the step of driving the PWM control signal output of at least two of the target LED groups to have a phase difference includes: (1) Determine the cut-in time and cut-out time of each target LED group according to the target PWM duty cycle of each target LED group; (2) Based on the cut-in time and cut-out time, drive at least two of the main target LED groups to stagger their PWM control signals.

[0027] Specifically, the step of staggering the PWM control signals driving at least two of the target LED groups includes: Before the PWM control signal driving one of the target LED groups is switched off, the PWM control signal driving the other target LED group is switched on; for example... Figure 7When the low beam LED headlight assembly (LB) switches off power, the high beam LED headlight assembly (HB) switches on power. Figure 8 Before the low beam LED light group LB switches off power, the high beam LED light group HB has already switched off power.

[0028] Step S106 provides a clear timing design method by specifying the "phase difference" as the staggered "cut-in / cut-out time", so that the conduction periods of multiple lamp groups partially overlap or switch sequentially, realizing "complementary switching", so that the change in total load (number of lamp groups in operation) during switching reduces output voltage fluctuations and suppresses current surges.

[0029] S107, drive the main voltage conversion circuit to output the calibrated peak current, and control the on / off state of the main switch circuit according to the PWM control signal to adjust the working state of the target LED group.

[0030] This invention discloses a drive control method for vehicle lighting control circuits. This method dynamically selects the maximum drive current as the calibration peak current based on the currently requested combination of light groups to be illuminated; calculates the calibration PWM duty cycle according to the ratio of the drive current of each light group to the peak current; if the maximum duty cycle is exceeded, the peak current is corrected in reverse; a PWM signal is generated, and the PWM signals of at least two of the target LED light groups are made to have a phase difference; finally, the peak current is output by the drive voltage conversion circuit and the switching circuit is controlled. Using this drive control method for vehicle lighting control circuits, the PWM duty cycle and switching sequence of each light group can be coordinated, suppressing output voltage fluctuations.

[0031] like Figure 8 As shown, Figure 8 The flowchart shown is a second embodiment of a drive control method for a vehicle lighting control circuit according to the present invention, including: S201, Obtain the preset driving current in each of the main LED groups; S202, collect the electrical signals of each input port respectively, so as to identify the main LED group that is currently requested to be lit according to the electrical signals, and use the main LED group as the target LED group; S203, Select the maximum value of the driving current in the target LED group as the calibration peak current; S204, calculate the calibrated PWM duty cycle of each target LED group respectively; S205, determine whether all the calibrated PWM duty cycles are less than or equal to the preset maximum duty cycle. If the determination is yes, the calibrated PWM duty cycle is marked as the target PWM duty cycle. If the determination is negative, the calibrated peak current is corrected according to the maximum duty cycle and the calibrated PWM duty cycle of each target LED group is recalculated until all the calibrated PWM duty cycles are less than or equal to the maximum duty cycle. S206, Generate a PWM control signal according to the target PWM duty cycle, and drive at least two of the target LED groups to output PWM control signals with a phase difference; S207, drives the main voltage conversion circuit to output the calibrated peak current, and controls the on / off state of the main switching circuit according to the PWM control signal; S208: Collect the temperature signal of the main LED group. When the temperature exceeds the preset threshold, adjust the target PWM duty cycle of the corresponding target LED group or turn off the output.

[0032] Step S208 implements overheat protection to prevent LEDs from light decaying or burning out due to high temperatures, thereby extending the life of the lamps and improving driving safety.

[0033] like Figure 9 As shown, Figure 9 The diagram shows a third embodiment of the vehicle lighting control circuit. In this third embodiment, the vehicle lighting control circuit further includes an overheat protection module 300 for collecting the temperature signal of the main LED lamp group. The overheat protection module 300 is connected to the main lighting module 200.

[0034] like Figure 10 As shown, specifically, the overheat protection module 300 includes a tenth resistor R10, an eleventh resistor R11, an eighth capacitor C8, and a ninth capacitor C9. One end of the tenth resistor R10 is connected to the main lighting module 200 (via the connection port "NTC_LED") and to one end of the eighth capacitor C8 and one end of the eleventh resistor R11. The other end of the tenth resistor R11 is connected to the power supply (via the connection port "VCC_SYS"), and the other end of the eighth capacitor C8 is grounded. The other end of the eleventh resistor R11 passes through one end of the ninth capacitor C9 and is connected to the microcontroller (via the connection port "AD_NTC_LED"). The other end of the ninth capacitor C9 is grounded. like Figure 11 As shown, Figure 11The diagram shows a fourth embodiment of the vehicle lighting control circuit. In the fourth embodiment of the vehicle lighting control circuit, the main switch unit 202 includes a first switch circuit 202a, a second switch circuit 202b, and a third switch circuit 202c. The main LED unit 203 includes a first main LED light group 203a, a second main LED light group 203b, and a third main LED light group 203c connected in series. One end of the first switching circuit 202a, one end of the second switching circuit 202b, and one end of the first main LED light group 203a are all connected to the main voltage conversion circuit 201. The other end of the first switching circuit 202a is connected to the other end of the first main LED light group 203a and one end of the second main LED light group 203b. The other end of the second switching circuit 202b is connected to one end of the third switching circuit 202c, the other end of the second main LED light group 203b, and one end of the third main LED light group 203c. The other end of the third switching circuit 202c is connected to the other end of the third main LED light group 203c and grounded.

[0035] like Figure 12 As shown, both the first switching circuit 202a and the second switching circuit 202b include a first resistor R1, a first diode D1, a first capacitor C1, a first MOSFET Q1, a second capacitor C2, a third capacitor C3, a transistor Q2, a second resistor R2, a fourth capacitor C4, a third resistor R3, and a fourth resistor R4. The source of the first MOSFET Q1 is connected to the negative terminal of the first diode C1; The drain of the first MOS transistor Q1 is connected to one end of the second capacitor C2, and is grounded through the third capacitor C3; The gate of the first MOS transistor Q1 is connected to the positive terminal of the first diode C1, the other end of the second capacitor C2, and the collector of the transistor Q2. The first diode C1, the first resistor R1, and the first capacitor C1 are connected in parallel. The emitter of transistor Q2 is grounded through the fourth resistor R4, and the base of transistor Q2 is connected to the microcontroller through the second resistor R2 (connected through the connection port "PWM") and grounded through the fourth capacitor C4. The fourth capacitor C4 is connected in parallel with the third resistor R3.

[0036] The third switching circuit 202c includes a fifth resistor R5, a sixth resistor R6, a fifth capacitor C5, a second MOSFET Q3, and a sixth capacitor C6. The gate of the second MOSFET Q3 is connected to the microcontroller via the fifth resistor R5 (connected via the "PWM" connection port) and grounded via the sixth resistor R6, which is connected in parallel with the sixth capacitor C6; The drain of the second MOSFET Q3 is connected to the gate of the second MOSFET Q3 through the fifth capacitor C5; The source of the second MOSFET Q3 is grounded.

[0037] It should be noted that, Figure 7 In the diagram, connection endpoint "203a" indicates connection to one end of the first main LED light group 203a, connection endpoint "203a / 203b" indicates connection to the other end of the first main LED light group 203a and one end of the second main LED light group 203b, and connection endpoint "203b / 203c" indicates connection to the other end of the second main LED light group 203b and one end of the third main LED light group 203c.

[0038] In summary, the driving control method for vehicle lighting control circuits of this invention dynamically selects the maximum driving current as the calibration peak current based on the currently requested combination of lamp groups; calculates the calibration PWM duty cycle according to the ratio of the driving current of each lamp group to the peak current; if the maximum duty cycle is exceeded, the peak current is corrected in reverse; a PWM signal is generated and the PWM signals of at least two of the target LED lamp groups have a phase difference; finally, the driving voltage conversion circuit outputs the peak current and controls the switching circuit. Using the driving control method for vehicle lighting control circuits of this invention, the PWM duty cycle and switching sequence of each lamp group can be coordinated, suppressing output voltage fluctuations. Furthermore, by staggering the input / output times, the output voltage of the main voltage conversion circuit can maintain small fluctuations during load switching, suppressing voltage surges and electromagnetic interference; the anti-interference capability and vehicle model adaptability are enhanced through the input signal acquisition method and specific adjustment circuit; and the system safety is improved by introducing overheat protection, automatically reducing the duty cycle or shutting down when the threshold is exceeded.

[0039] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A drive control method for a vehicle lighting control circuit, characterized in that, The vehicle lighting control circuit includes a port module and a main lighting module. The main lighting module includes a main voltage conversion circuit, a main switching unit, and a main LED unit. The main switching unit includes several main switching circuits. The main LED unit includes several main LED groups connected in series. The port module includes an input port and a main output port corresponding to each of the main LED groups. One end of the main voltage conversion circuit is connected to the main output port, and the other end of the main voltage conversion circuit is connected to the main LED group through the main switching unit. The drive control method includes: Obtain the preset driving current in each of the main LED groups; The electrical signals of each input port are collected respectively, so as to identify the main LED group that is currently requested to be lit based on the electrical signals, and the main LED group is used as the target LED group; The maximum value of the driving current in the target LED group is selected as the calibration peak current; Calculate the calibrated PWM duty cycle for each target LED group, where the calibrated PWM duty cycle is the ratio of the drive current of the target LED group to the calibrated peak current. Determine whether all the calibrated PWM duty cycles are less than or equal to the preset maximum duty cycle. If the determination is yes, the calibrated PWM duty cycle is marked as the target PWM duty cycle. If the determination is negative, the calibrated peak current is corrected according to the maximum duty cycle and the calibrated PWM duty cycle of each target LED group is recalculated until all the calibrated PWM duty cycles are less than or equal to the maximum duty cycle. A PWM control signal is generated based on the target PWM duty cycle, and the PWM control signal outputs of at least two of the target LED groups are driven to have a phase difference. The main voltage conversion circuit is driven to output the calibrated peak current, and the on / off state of the main switching circuit is controlled according to the PWM control signal to adjust the working state of the target LED group.

2. The drive control method for a vehicle lighting control circuit according to claim 1, characterized in that, The step of correcting the calibrated peak current based on the maximum duty cycle includes: According to the formula Correct the calibrated peak current; in, This is the corrected calibration peak current. The calibration peak current before correction. This represents the maximum duty cycle.

3. The drive control method for a vehicle lighting control circuit according to claim 2, characterized in that, The maximum duty cycle is ≤95%.

4. The drive control method for a vehicle lighting control circuit according to claim 1, characterized in that, The step of driving at least two of the target LED groups to output PWM control signals with a phase difference includes: Based on the target PWM duty cycle of each target LED group, determine the cut-in time and cut-out time of each target LED group; The PWM control signals driving at least two of the target LED groups are staggered according to the cut-in and cut-out times.

5. The drive control method for a vehicle lighting control circuit according to claim 4, characterized in that, The step of staggering the PWM control signals driving at least two of the target LED groups includes: Before the PWM control signal driving one of the target LED groups is switched off, the PWM control signal driving the other target LED group is switched on.

6. The drive control method for a vehicle lighting control circuit according to claim 1, characterized in that, The electrical signals are acquired through methods including AD sampling, CAN communication, LIN communication, level logic detection, or duty cycle detection.

7. The drive control method for a vehicle lighting control circuit according to claim 6, characterized in that, The vehicle lighting control circuit also includes a voltage acquisition module for acquiring electrical signals from the input ports. The voltage acquisition module includes voltage divider and filter acquisition circuits corresponding to each of the input ports.

8. The drive control method for a vehicle lighting control circuit according to claim 1, characterized in that, Also includes: The temperature signal of the main LED group is collected. When the temperature exceeds the preset threshold, the target PWM duty cycle of the corresponding target LED group is adjusted or the output is turned off.

9. The drive control method for a vehicle lighting control circuit according to claim 8, characterized in that, The vehicle lighting control circuit also includes an overheat protection module for collecting the temperature signal of the main LED light group, and the overheat protection module is connected to the main lighting module.

10. The drive control method for a vehicle lighting control circuit according to claim 1, characterized in that, The main switch unit includes a first switch circuit, a second switch circuit, and a third switch circuit, and the main LED unit includes a first main LED light group, a second main LED light group, and a third main LED light group connected in series. One end of the first switching circuit, one end of the second switching circuit, and one end of the first main LED group are all connected to the main voltage conversion circuit. The other end of the first switching circuit is connected to the other end of the first main LED group and one end of the second main LED group. The other end of the second switching circuit is connected to one end of the third switching circuit, the other end of the second main LED group, and one end of the third main LED group. The other end of the third switching circuit is connected to the other end of the third main LED group and grounded.

11. The drive control method for a vehicle lighting control circuit according to claim 10, characterized in that, Both the first and second switching circuits include a first resistor, a first diode, a first capacitor, a first MOSFET, a second capacitor, a third capacitor, a transistor, a second resistor, a fourth capacitor, a third resistor, and a fourth resistor. The source of the first MOSFET is connected to the negative terminal of the first diode; The drain of the first MOS transistor is connected to one end of the second capacitor and grounded through the third capacitor; The gate of the first MOS transistor is connected to the anode of the first diode, the other end of the second capacitor, and the collector of the transistor. The first diode, the first resistor, and the first capacitor are connected in parallel. The emitter of the transistor is grounded through the fourth resistor, the base of the transistor is connected to the second resistor and grounded through the fourth capacitor, and the fourth capacitor is connected in parallel with the third resistor.

12. The drive control method for a vehicle lighting control circuit according to claim 11, characterized in that, The third switching circuit includes a fifth resistor, a sixth resistor, a fifth capacitor, a second MOSFET, and a sixth capacitor; The gate of the second MOS transistor is connected to the fifth resistor and grounded through the sixth resistor, which is connected in parallel with the sixth capacitor; The drain of the second MOS transistor is connected to the gate of the second MOS transistor through the fifth capacitor; The source of the second MOSFET is grounded.

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