Search

CN-122028252-A - Light intensity power supply feedback method based on broadband pulse modulation

CN122028252ACN 122028252 ACN122028252 ACN 122028252ACN-122028252-A

Abstract

The invention provides a lamplight intensity power supply feedback method based on broadband pulse modulation, which relates to the technical field of power supply control and comprises the steps of dividing each dimming frame into a luminous area, a detection area and a migration area, dividing each dimming frame into continuous micro time slots, generating a front detection pulse group and a rear detection pulse group in the detection area, collecting corresponding light intensity edge response, driving current edge response and power supply bus transient response, constructing a micro time slot disturbance traffic map through mirror image difference and unified time base alignment, determining a limited micro time slot and an admission micro time slot according to a disturbed quantity, a recovered quantity and a transfer lag quantity, migrating luminous tasks in the limited micro time slots to blank micro time slots in the admission micro time slots and the migration area, generating a migration compensation pulse sequence, and realizing lamplight intensity refined power supply feedback control under the condition that the target average brightness is unchanged. The method is suitable for popularization and application in scenes such as industrial illumination, photography light filling, machine vision surface light source and the like.

Inventors

  • WANG LIN
  • Wu Dongkan

Assignees

  • 上海万文科技有限公司

Dates

Publication Date
20260512
Application Date
20260325

Claims (10)

  1. 1. A light intensity power supply feedback method based on broadband pulse modulation is characterized by comprising the following steps: sp1, dividing each dimming frame into a light-emitting area, a detection area and a migration area according to time sequence, dividing the dimming frame into a preset number of continuous micro time slots, generating a reference light-emitting pulse sequence in the light-emitting area, generating a front detection pulse group and a rear detection pulse group in the detection area, and reserving blank micro time slots in the migration area, wherein the total conduction time of the front detection pulse group and the rear detection pulse group is the same, the total light-emitting quantity is the same, and the time distribution is opposite; sp2, synchronously collecting light intensity edge response, driving current edge response and power supply bus transient response corresponding to the front detection pulse group and the rear detection pulse group during the period that the dimming frame acts on the illumination light source, and mapping the collection result to corresponding micro time slots in time sequence; sp3, carrying out front and back detection pulse mirror image difference and unified time base alignment on the light intensity edge response, the driving current edge response and the power supply bus transient response mapped to each micro time slot to obtain the disturbed quantity, the recovered quantity and the transfer lag quantity of each micro time slot, and constructing a micro time slot disturbance traffic map; sp4, determining the micro time slots with the disturbance quantity larger than the limited threshold value as limited micro time slots according to the micro time slot disturbance traffic map, determining the micro time slots with the disturbance quantity smaller than the admission threshold value and the recovery quantity meeting the recovery condition as admission micro time slots, and determining the quantity of the luminous tasks to be migrated in each limited micro time slot according to the reference luminous pulse sequence; sp5, under the conditions that the target average brightness of the current dimming frame is kept unchanged, the total on time of the whole frame is unchanged, the peak driving current does not exceed the safety upper limit, and the adjacent pulse interval is not smaller than the safety interval, migrating the to-be-migrated luminous task quantity in each limited micro time slot to the admission micro time slot and the blank micro time slot in the migration zone, and generating a migration compensation pulse sequence; And sp6, outputting a next dimming frame comprising the reference light-emitting pulse sequence, the front detection pulse group, the rear detection pulse group and the migration compensation pulse sequence, and repeatedly executing sp1 to sp6 in the subsequent dimming frame so as to realize the fine power supply feedback control of the light intensity.
  2. 2. The method of claim 1, wherein the front detection pulse group is disposed in a front half of the detection area, the rear detection pulse group is disposed in a rear half of the detection area, the front detection pulse group and the rear detection pulse group have the same single pulse width, the same single pulse amplitude and the same pulse number at the corresponding positions, and the time distances from the pulses to the boundaries of the corresponding detection areas are mirror images of each other.
  3. 3. The method for feeding back the light intensity power modulated by the broadband pulse according to claim 1, wherein synchronous acquisition in sp2 is completed by adopting a unified trigger time base, a light intensity acquisition channel, a driving current acquisition channel and a power supply bus acquisition channel are started by the same frame trigger signal, and sampling start and sampling end are completed on the same micro time slot boundary, so that the corresponding relation of three types of response data on a time axis is ensured to be fixed.
  4. 4. A light intensity power supply feedback method of broadband pulse modulation as set forth in claim 1, wherein the disturbance variable in sp3 is determined by a light intensity setup delay, a driving current follow delay and a power supply bus voltage drop duration, the recovery variable is determined by a light intensity fall completion time and a power supply bus recovery completion time, the transfer hysteresis variable is determined by a time shift of a light intensity edge response relative to a driving current edge response, and the micro-slot disturbance traffic map is formed by arranging the disturbance variable, the recovery variable and the transfer hysteresis variable of each micro-slot in time sequence.
  5. 5. The method for feeding back the light intensity power modulated by the broadband pulse according to claim 1, wherein in sp4, the limited micro time slots are ordered from large to small according to the disturbed amount, the receiving micro time slots are ordered from small to large according to the disturbed amount and the recovery amount is ordered from large to small, and the light emitting task amount to be migrated is determined according to the actual on time of the reference light emitting pulse sequence in the limited micro time slots.
  6. 6. The method of claim 1, wherein the blank micro-slots in the transition area occupy a fixed proportion of the micro-slot number in each dimming frame, the fixed proportion is written into the controller during system initialization and is kept unchanged during normal operation, and the blank micro-slots are only used for receiving the light-emitting tasks which are migrated from the limited micro-slots and not used for receiving the reference light-emitting tasks.
  7. 7. The method for feeding back the light intensity power modulated by the broadband pulse according to claim 1, wherein the light emitting task in sp5 is migrated by adopting a neighbor priority rule, namely, the amount of the light emitting task to be migrated in the limited micro time slot is migrated to an admission micro time slot with the smallest time distance, and when the receiving capacity of the corresponding admission micro time slot is insufficient, the light emitting task is migrated to a blank micro time slot in the migration area.
  8. 8. The method of claim 1, wherein the shift compensation pulse sequence in sp5 keeps the main frequency frame of the reference light-emitting pulse sequence unchanged, and only performs shifting-out of the local light-emitting tasks in the limited micro-time slots, and performs shifting-in of the local light-emitting tasks in the admission micro-time slots and the blank micro-time slots, so that the whole frame pulse structure is kept continuous.
  9. 9. A light intensity power supply feedback method of broadband pulse modulation as set forth in claim 1 wherein when a minislot at the same location in a continuous preset number of dimming frames is determined to be a limited minislot, the system marks the location as a fixed fragile minislot and decreases the default duty cycle of the fixed fragile minislot while increasing the default receiving duty cycle of the admittance minislot and the migration zone blank minislot adjacent thereto when subsequently generating said reference light pulse sequence.
  10. 10. The method of claim 1, wherein when the receiving micro-slot and the blank micro-slot in the migration area are insufficient to receive all the tasks to be migrated, the system preferably ensures continuous light emission of the visually sensitive section in the light-emitting area, and disperses and migrates the remaining tasks into discontinuous micro-slots with disturbance values lower than a limited threshold and recovery values meeting recovery conditions to suppress perceptible flicker.

Description

Light intensity power supply feedback method based on broadband pulse modulation Technical Field The invention relates to the technical field of power control, in particular to a broadband pulse modulation lamplight intensity power supply feedback method. Background Semiconductor lighting devices are widely used in scenes such as industrial lighting, commercial lighting, photographic light filling, machine vision surface light source, medical lighting, and precision inspection lighting. Existing lighting systems typically employ constant current drive, linear dimming, pulse width modulation dimming, or average current closed loop based brightness control schemes to achieve light output adjustment by varying the drive current magnitude, turn-on duty cycle, or pulse repetition frequency. In the scene of stable power supply condition and small load disturbance, the control mode can meet the general lighting requirement. In practical applications, the power supply bus to which the lighting device is connected often carries a motor, a frequency converter, an electric welding machine, an air compressor, a heating device, a camera system, a communication device or other periodic switching loads at the same time, and these loads may cause voltage drop, ripple enhancement, short-time lifting, repetitive current impact and transient recovery delay of the power supply bus during start-stop, switching and impact. For led light sources, the above-mentioned variations in the supply bus are transferred to the drive loop, which shifts the drive current build-up, sustain and turn-off processes, resulting in light output build-up delays, light output fall-back anomalies and local period brightness fluctuations. Especially in high power illumination, photography light filling and machine vision scenes, short-time instabilities in the light output can manifest themselves directly as brightness jitter, local flicker, exposure non-uniformities, imaging fringes or detection errors. Common improvements in the prior art include adding a filter device on the driving side, compensating by adjusting the duty cycle by software, establishing a correspondence between the average current and the average light intensity, or maintaining overall brightness stability by feedback control. Such approaches are primarily directed to correcting for variations in the average brightness or longer time scale of the entire frame, and lack fine-grained recognition of the differential response of the power supply disturbance at different time locations within a single frame. When the situation that the local period is severely disturbed and the local period is quickly recovered exists in the same dimming frame, it is difficult to judge which time positions are suitable for bearing the light-emitting task and which time positions should avoid the main light-emitting task only by means of average value feedback, so that finer compensation cannot be completed under the condition that the average conduction proportion of the whole frame is not improved. . Disclosure of Invention Technical problem to be solved Aiming at the defects of the prior art, the invention provides a broadband pulse modulation light intensity power supply feedback method, which solves the problems of the prior art. Technical proposal The invention is realized by the following technical scheme that the light intensity power supply feedback method for broadband pulse modulation comprises the following steps: sp1, dividing each dimming frame into a light-emitting area, a detection area and a migration area according to time sequence, dividing the dimming frame into a preset number of continuous micro time slots, generating a reference light-emitting pulse sequence in the light-emitting area, generating a front detection pulse group and a rear detection pulse group in the detection area, and reserving blank micro time slots in the migration area, wherein the total conduction time of the front detection pulse group and the rear detection pulse group is the same, the total light-emitting quantity is the same, and the time distribution is opposite; sp2, synchronously collecting light intensity edge response, driving current edge response and power supply bus transient response corresponding to the front detection pulse group and the rear detection pulse group during the period that the dimming frame acts on the illumination light source, and mapping the collection result to corresponding micro time slots in time sequence; sp3, carrying out front and back detection pulse mirror image difference and unified time base alignment on the light intensity edge response, the driving current edge response and the power supply bus transient response mapped to each micro time slot to obtain the disturbed quantity, the recovered quantity and the transfer lag quantity of each micro time slot, and constructing a micro time slot disturbance traffic map; sp4, determining the micro time slots with the disturb