An adaptive exposure circuit for a fusion vision sensor

Abstract

The application discloses a kind of adaptive exposure circuits for fusion vision sensor, comprising: event statistics module, event quantity judging module, exposure time control module and grey statistics module;Event statistics module is used to the event data generated by fusion vision sensor is counted, and the statistical result is output to event quantity judging module;Event quantity judging module judges the statistical result, and the judging result is transmitted to exposure time control module;Grey statistics module is used to count grey information, and the statistical result is transmitted to exposure time control module;Exposure time control module will be according to judging result and grey information, corresponding adjustment is carried out to exposure time.The adaptive exposure circuit for fusion vision sensor described in the embodiment of the application realizes the phenomenon such as overexposure or underexposure caused by the change of external light intensity by the cooperation of each module, and then improves the imaging quality of fusion vision sensor.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of fusion visual sensor exposure circuit, and particularly relates to a self-adaptive exposure circuit for a fusion visual sensor. BACKGROUND

[0002] The progress of artificial intelligence and automatic driving has given birth to a new era of intelligent perception, and at the same time has put forward higher requirements for image sensors. In order to face more complex lighting scenes and meet the perception needs of high speed and low power consumption, the visual system puts forward higher requirements for the rate and dynamic range of image sensors. However, the traditional COMS image sensor is limited by the sensing mode, and the performance is difficult to continue to improve.

[0003] In order to solve the above-mentioned problems in the traditional image sensor, people refer to the human neural visual system and propose a new type of image sensor, namely event-based vision sensor (EVS). The event-based vision sensor is a sensor that detects and outputs the change of external light intensity. Each pixel independently perceives the change of light intensity and is discretized into events of light intensity increase and light intensity decrease. Compared with the traditional integral type CMOS sensor, it outputs less data, responds faster and consumes less power. Therefore, the event-based vision sensor has a wide application in high speed, high real-time and high dynamic range occasions. However, the event-based vision sensor generally has poor image visibility due to the lack of absolute light intensity information. Therefore, people embed CIS pixels in the EVS pixels, and get a hybrid event-based vision sensor (RGB Hybrid Event-Based Vision Sensor) that can output gray scale, which can better solve the problems in the field of image processing. In order to better output gray scale and improve the imaging quality of the hybrid event-based vision sensor, the present application provides a self-adaptive exposure circuit for a hybrid event-based vision sensor. SUMMARY

[0004] The technical problem to be solved by the present application is that in order to solve the various deficiencies existing in the existing visual sensor, the present application provides a self-adaptive exposure circuit for a hybrid event-based vision sensor.

[0005] In order to solve the above technical problems, the embodiment of the present application provides a self-adaptive exposure circuit for a hybrid event-based vision sensor, which comprises an event statistics module, an event number judgment module, an exposure time control module and a gray scale statistics module.

[0006] The event statistics module is used for counting the light intensity increase events and light intensity decrease events generated by the hybrid event-based vision sensor, and outputting the counting results to the event number judgment module.

[0007] The event quantity judging module is configured to judge the statistical result and transmit the judging result to the exposure time control module.

[0008] The gray scale statistical module is configured to count the gray scale information of the fusion visual sensor and transmit the statistical result to the exposure time control module.

[0009] The exposure time control module is configured to adjust the exposure time according to the judging result and the gray scale information.

[0010] Preferably, the event quantity judging module comprises a first threshold value and a second threshold value; when the number of the light intensity increasing events minus the number of the light intensity decreasing events is greater than or equal to the first threshold value, the event quantity judging module outputs a first judging result; when the number of the light intensity decreasing events minus the number of the light intensity increasing events is greater than or equal to the second threshold value, the event quantity judging module outputs a second judging result; when the number of the light intensity increasing events minus the number of the light intensity decreasing events is less than the first threshold value and the number of the light intensity decreasing events minus the number of the light intensity increasing events is less than the second threshold value, the event quantity judging module outputs a third judging result.

[0011] Preferably, the gray scale statistical module comprises a third threshold value, a fourth threshold value, a fifth threshold value and a sixth threshold value; when the gray scale information is less than the third threshold value, the gray scale statistical module judges the gray scale information as low gray scale pixel information and counts the number of the low gray scale pixel information; when the gray scale information is greater than the fourth threshold value, the gray scale statistical module judges the gray scale information as high gray scale pixel information and counts the number of the high gray scale pixel information; when the number of the low gray scale pixel information is greater than the fifth threshold value, a first statistical result is outputted; when the number of the high gray scale pixel information is greater than the sixth threshold value, a second statistical result is outputted.

[0012] Preferably, the third threshold value is less than the fourth threshold value.

[0013] Preferably, the event quantity judging module comprises a first subtractor, a second subtractor, a first comparator, a second comparator and an XOR gate.

[0014] The input ends of the first subtractor and the second subtractor are connected with the event counting module; the output end of the first subtractor is connected with the input end of the first comparator; the output end of the second subtractor is connected with the input end of the second comparator; the output ends of the first comparator and the second comparator are connected with the input end of the XOR gate; the output ends of the first comparator, the second comparator and the XOR gate are connected with the exposure time control module as the output ends of the event quantity judging module.

[0015] Preferably, the other input terminal of the first comparator is connected with a first threshold value; the other input terminal of the second comparator is connected with a second threshold value.

[0016] Preferably, the gray scale statistics module comprises a third comparator, a fourth comparator, a fifth comparator, a sixth comparator, a first D flip-flop, a second D flip-flop, a first adder and a second adder.

[0017] The input terminals of the third comparator and the fourth comparator are connected with the gray scale information; the output terminal of the third comparator and the output terminal of the first D flip-flop are connected with the input terminal of the first adder; the output terminal of the first adder is connected with the input terminal of the first D flip-flop and the input terminal of the fifth comparator; the output terminal of the fourth comparator and the output terminal of the second D flip-flop are connected with the input terminal of the second adder; the output terminal of the second adder is connected with the input terminal of the second D flip-flop and the input terminal of the sixth comparator; the output terminal of the fifth comparator and the output terminal of the sixth comparator output the statistics result as the output terminal of the gray scale statistics module.

[0018] Preferably, the other input terminal of the third comparator is connected with a third threshold value; when the gray scale information is less than the third threshold value, the first D flip-flop increases the stored data by 1; the other input terminal of the fourth comparator is connected with a fourth threshold value; when the gray scale information is greater than the fourth threshold value, the second D flip-flop increases the stored data by 1; the other input terminal of the fifth comparator is connected with a fifth threshold value; the other input terminal of the sixth comparator is connected with a sixth threshold value.

[0019] Preferably, the exposure time control module comprises a third D flip-flop, a right shift register, a left shift register and a selector.

[0020] The output terminal of the third D flip-flop is connected with the input terminal of the right shift register, the input terminal of the left shift register and the input terminal of the selector; the output terminal of the right shift register and the output terminal of the left shift register are connected with the input terminal of the selector; the output terminal of the selector is connected with the input terminal of the third D flip-flop; the selection terminal of the selector is connected with the output terminal of the gray scale statistics module and the input terminal of the event number judgment module as the input terminal of the exposure time control module.

[0021] Preferably, the event statistics module comprises a first event buffer, a first adder group, a first accumulation register, a second event buffer, a second adder group and a second accumulation register.

[0022] The first event buffer is used for storing light intensity increase events generated by the fusion visual sensor, and the output end is connected with the input end of the first adder group; the first adder group is used for accumulating the light intensity increase events, and the output end is connected with the input end of the first accumulation register; the first accumulation register is used for storing the light intensity increase event statistical result, and outputting the light intensity increase event statistical result to the event quantity judgment module.

[0023] Preferably, the second event buffer is used for storing light intensity decrease events generated by the fusion visual sensor, and the output end is connected with the input end of the second adder group; the second adder group is used for accumulating the light intensity decrease events, and the output end is connected with the input end of the second accumulation register; the second accumulation register is used for storing the light intensity decrease event statistical result, and outputting the light intensity decrease event statistical result to the event quantity judgment module.

[0024] The embodiment of the present application has the following beneficial effects:

[0025] (1) The embodiment of the present application, before the next exposure of the fusion visual sensor, the event statistical module is used to count the light intensity increase events (ON events) and the light intensity decrease events (OFF events), and then the event quantity judgment module is used to compare the number of ON events and OFF events and output the comparison result. The gray scale statistical module is used to count the gray scale information of the fusion visual sensor and output the statistical result. Finally, the exposure time control module is used to determine whether to increase the exposure time, reduce the exposure time or keep unchanged according to the output of the event quantity judgment module and the gray scale statistical module, so as to prevent the overexposure or underexposure caused by the change of external light intensity, and improve the imaging quality of the fusion visual sensor. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0027] Figure 1 A self-adaptive exposure circuit structure schematic diagram for a fusion visual sensor is provided for the embodiment of the present application;

[0028] Figure 2 A self-adaptive exposure circuit and pixel array connection structure schematic diagram for a fusion visual sensor is provided for the embodiment of the present application;

[0029] Figure 3A flow chart of an adaptive exposure circuit for a fusion vision sensor is provided for implementation of the present application.

[0030] Figure 4 A flow chart of an adaptive exposure circuit control algorithm for a fusion vision sensor is provided for implementation of the present application.

[0031] Figure 5 A structure diagram of an event number judging module of an adaptive exposure circuit for a fusion vision sensor is provided for implementation of the present application.

[0032] Figure 6 A structure diagram of a gray scale statistics module of an adaptive exposure circuit for a fusion vision sensor is provided for implementation of the present application.

[0033] Figure 7 A structure diagram of an exposure time control module of an adaptive exposure circuit for a fusion vision sensor is provided for implementation of the present application. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0035] As Figures 1-7As shown, the embodiment discloses an adaptive exposure circuit for fusion visual sensor. The adaptive exposure circuit for fusion visual sensor is used to be connected with a fusion visual sensor pixel array. The fusion visual sensor pixel array is a 640x480 pixel array. Each pixel group includes 4 event pixels and 12 RGB pixels, forming a 4x4 structure. The fusion visual sensor pixel array receives external light intensity and generates a series of ON / OFF events according to the relative change of external light intensity under the regulation of the EVS control circuit, and sends the series of ON / OFF events to the column sampling circuit. After receiving the series of ON / OFF events, the column sampling circuit sends them to the EVS signal processing circuit and the adaptive exposure circuit for fusion visual sensor. At the same time, the voltage information of the RGB pixel is transmitted to the RGB signal processing circuit and the adaptive exposure circuit after being sampled by the column ADC. The adaptive exposure circuit for fusion visual sensor will flexibly adjust the exposure time according to the difference between the number of ON / OFF events and the number of gray scale information of the fusion visual sensor, and transmit the adjusted exposure time to the RGB control circuit. Then control the exposure of the fusion visual sensor pixel array, and finally transmit the ON / OFF event data and the gray scale information data together to the off-chip through the output interface circuit.

[0036] Specifically, the adaptive exposure circuit for fusion visual sensor includes an event statistics module 10, an event quantity judgment module 20, a gray scale statistics module 30 and an exposure time control module 40. The event statistics module 10 is used to count the ON events and OFF events generated by the fusion visual sensor, and output the counting result to the event quantity judgment module 20. The event quantity judgment module 20 is used to judge the counting result, and transmit the judgment result to the exposure time control module 40. The gray scale statistics module 30 is used to count the gray scale information of the fusion visual sensor, and transmit the counting result to the exposure time control module 40. The exposure time control module 40 is used to adjust the exposure time according to the judgment result and the gray scale information.

[0037] The event quantity judging module 20 includes a first threshold (Umax_1) and a second threshold (Umax_2). When the ON event quantity minus the OFF event quantity is greater than or equal to the first threshold, the event quantity judging module outputs a first judging result (Flag_ON>>OFF); when the OFF event quantity minus the ON event quantity is greater than or equal to the second threshold, the event quantity judging module outputs a second judging result (Flag_ON<<OFF); and when the ON event quantity minus the OFF event quantity is less than the first threshold and the OFF event quantity minus the ON event quantity is less than the second threshold, the event quantity judging module outputs a third judging result (Flag_ON≈OFF). The first threshold and the second threshold can be set as needed. When the external light is dim, the first threshold can be appropriately increased and the second threshold can be appropriately decreased; when the external light is bright, the first threshold can be appropriately decreased and the second threshold can be appropriately increased.

[0038] The gray scale statistical module 30 includes a third threshold (Gray_thr1), a fourth threshold (Gray_thr2), a fifth threshold (max_1), and a sixth threshold (max_2). When the gray scale information is less than the third threshold, the gray scale statistical module 30 judges that the gray scale information is low gray scale pixel information and counts the number of the low gray scale pixel information. When the gray scale information is greater than the fourth threshold, the gray scale statistical module 30 judges that the gray scale information is high gray scale pixel information and counts the number of the high gray scale pixel information. When the number of the low gray scale pixel information is greater than the fifth threshold, a first statistical result (Flag_dark) is output. When the number of the high gray scale pixel information is greater than the sixth threshold, a second statistical result (Flag_bright) is output. The third threshold, the fourth threshold, the fifth threshold, and the sixth threshold can be set as needed. In different cases, different sizes can be set. The third threshold is less than the fourth threshold.

[0039] The adaptive exposure circuit for a fusion visual sensor determines how to adjust the exposure time by counting the number of ON and OFF events generated by the pixel array of the fusion visual sensor and the number of high and low gray scale pixel information. The ON and OFF events generated by the EVS pixel carry the change information of the external light intensity, and the time required to generate an event pulse is very short, reaching the nanosecond level, which is much lower than the gray scale information data. Therefore, it is possible to use the ON and OFF event data to help adjust the exposure time. In this way, the fusion visual sensor using the adaptive exposure circuit for a fusion visual sensor has a large dynamic range and can handle exposure problems under various external light conditions.

[0040] See Figure 3The adaptive exposure circuit of the fusion visual sensor specifically comprises the following working steps:

[0041] S1: pixel array response;

[0042] S2: row and column control circuit regulation;

[0043] S3: the event statistics module 10 and the event quantity judgment module 20 cache ON and OFF events and count the number of ON and OFF events;

[0044] S4: the gray scale statistics module 30 counts the gray scale information;

[0045] S5: the exposure time control module 40 adjusts the exposure time according to the number of ON and OFF events and the gray scale information.

[0046] Specifically, after the fusion visual sensor pixel array response to the change of external light intensity generates events, the event data is read into the event buffer by the row and column control circuit. Then, the event statistics module 10 and the event quantity judgment module 20 count the ON and OFF event data, obtain the total number of ON and OFF events and calculate the difference. At the same time, the gray scale statistics module 30 counts the number of high and low gray scale pixel information. The exposure time control module 40 selectively increases or decreases the exposure time or keeps it unchanged according to the number of ON and OFF events and the gray scale statistics information, thereby realizing adaptive exposure.

[0047] Referring to Figure 4 The algorithm flow chart of the adaptive exposure circuit for the fusion visual sensor is specifically as follows: when the addition result of the ON and OFF event data of the event statistics module 10 is transmitted to the event quantity judgment module 20, the event quantity judgment module 20 calculates the difference between the two and compares the operation result with the first threshold value and the second threshold value thereof. At the same time, the gray scale statistics module 30 also compares the number of high and low gray scale pixel information with the sixth threshold value and the fifth threshold value. When the difference between the number of ON and OFF events is greater than or equal to the first threshold value and the number of high gray scale pixel information exceeds the sixth threshold value, the adaptive exposure circuit for the fusion visual sensor reduces the exposure time. When the difference is greater than or equal to the second threshold value and the number of low gray scale pixel information exceeds the fifth threshold value, the adaptive exposure circuit for the fusion visual sensor increases the exposure time. In other cases, the exposure time remains unchanged.

[0048] In the embodiment, Frame 1 generates 4783 ON events and 238 OFF events, and the difference between the number of ON events and OFF events is greater than Umax_1. At this time, if the number of high gray level pixel information has exceeded the sixth threshold, the adaptive exposure circuit for fusion visual sensor will reduce the exposure time, otherwise the exposure time remains unchanged. In this embodiment, the exposure time data is right shifted by one bit to achieve the purpose of reducing exposure. Frame 6 has 2314 ON events and 1984 OFF events, and the difference between the number of ON events and OFF events is not large, so the exposure time remains unchanged. Frame 9 generates 478 ON events and 5874 OFF events, and the number of OFF events is much greater than the number of ON events. At this time, if the number of low gray level pixel information has exceeded the fifth threshold, the adaptive exposure circuit for fusion visual sensor will increase the exposure time, and the exposure time data is left shifted by one bit, otherwise the exposure time remains unchanged.

[0049] Each time the exposure time is updated, the new data is transmitted to the RGB control circuit to control the exposure of the pixel array of the fusion visual sensor. In this way, by flexibly adjusting the exposure time according to the difference between the number of ON events and OFF events and the number of high and low gray level pixel information, the adaptive exposure circuit for fusion visual sensor can solve the problem of exposure time of fusion visual sensor under different external light intensity, and improve the imaging quality.

[0050] Please refer to Figure 1 and Figures 5-7 , the event statistics module 10 includes: a first event buffer 110, a first adder group 120, a first cumulative register 130, a second event buffer 140, a second adder group 150 and a second cumulative register 160. The first event buffer 110, the first adder group 120 and the first cumulative register 130 are used to count ON event data. The second event buffer 140, the second adder group 150 and the second cumulative register 160 are used to count OFF event data.

[0051] The first event buffer 110 is used to store the ON event data generated by the fusion visual sensor, and the output end is connected with the input end of the first adder group 120. The first adder group 120 is used to accumulate the ON event data, and the output end is connected with the input end of the first cumulative register 130. The first cumulative register 130 is used to store the ON event data statistics result, and output the ON event data statistics result to the event number judgment module 20.

[0052] The second event buffer 140 is used to store OFF event data generated by the fusion visual sensor, and the output end is connected with the input end of the second adder group 150. The second adder group 150 is used to accumulate the OFF event data, and the output end is connected with the input end of the second accumulation register 160. The second accumulation register 160 is used to store the OFF event data statistics result, and output the OFF event data statistics result to the event number judgment module 20.

[0053] Specifically, the event buffer is in a group of 16 bits, and 16 bits of data are sent to the adder group at a time. The number of "1" in the 16 bits of data, i.e. the number of ON and OFF events, is counted by the adder, so as to obtain a 5-bit statistics data. The 5-bit data will be stored in the accumulation register, reflecting the number of events generated by the pixel array. When the event accumulation of the ON and OFF event data is completed, the accumulation register will transmit the addition result to the event number judgment module 20. The event number judgment module 20 will output a 3-bit flag signal, i.e. the judgment result, according to the size relationship between the difference value of the number of ON and OFF events and the first and second thresholds.

[0054] Please also refer to Figure 5 The event number judgment module 20 includes a first subtractor 210, a second subtractor 220, a first comparator 230, a second comparator 240 and an XOR gate 250. The input ends of the first subtractor 210 and the second subtractor 220 are connected with the event statistics module 10. Specifically, the input ends of the first subtractor 210 and the second subtractor 220 are respectively connected with the output ends of the first accumulation register 130 and the second accumulation register 160. The output end of the first subtractor 210 is connected with the input end of the first comparator 230. The output end of the second subtractor 220 is connected with the input end of the second comparator 240. The output ends of the first comparator 230 and the second comparator 240 are connected with the input ends of the XOR gate 250. The output ends of the first comparator 230, the second comparator 240 and the XOR gate 250 are connected with the exposure time control module 40 as the output ends of the event number judgment module 20, and output the first judgment result, the second judgment result and the third judgment result to the exposure time control module 40 respectively. The other input end of the first comparator 230 is connected with the first threshold. The other input end of the second comparator 240 is connected with the second threshold. The input data of the minuend end and the subtrahend end of the first subtractor 210 is opposite to the input data of the minuend end and the subtrahend end of the second subtractor 220, i.e. the output of the first subtractor 210 is the number of ON events minus the number of OFF events, and the output of the second subtractor 220 is the number of OFF events minus the number of ON events.

[0055] Please see again Figure 6 The grayscale statistics module 30 includes: a third comparator 310, a fourth comparator 320, a fifth comparator 330, a sixth comparator 340, a first D flip-flop 350, a second D flip-flop 360, a first adder 370, and a second adder 380. The input terminals of the third comparator 310 and the fourth comparator 320 are connected to the grayscale information as input terminals of the grayscale statistics module 30. The output terminals of the third comparator 310 and the first D flip-flop 350 are connected to the input terminal of the first adder 370. The output terminal of the first adder 370 is connected to the input terminals of the first D flip-flop 350 and the fifth comparator 330. The output terminals of the fourth comparator 320 and the second D flip-flop 360 are connected to the input terminal of the second adder 380. The output terminal of the second adder 380 is connected to the input terminals of the second D flip-flop 360 and the sixth comparator 340. The output terminals of the fifth comparator 330 and the sixth comparator 340 serve as the output terminals of the grayscale statistics module 30, outputting the first statistical result and the second statistical result.

[0056] The third comparator 310 has another input connected to a third threshold, used to determine whether the input grayscale information is low-grayscale pixel information. When the grayscale information is less than the third threshold, the grayscale information is considered low-grayscale pixel information, and the first D flip-flop 350 increments its stored data by 1. The fourth comparator 320 has another input connected to a fourth threshold, used to determine whether the input grayscale information is high-grayscale pixel information. When the grayscale information is greater than the fourth threshold, the grayscale information is considered high-grayscale pixel information, and the second D flip-flop 360 increments its stored data by 1. The fifth comparator 330 has another input connected to a fifth threshold. The sixth comparator 340 has another input connected to a sixth threshold. The fifth comparator 330 and the sixth comparator 340 are used to determine whether the number of high and low grayscale pixel information counted by the first D flip-flop 350 and the second D flip-flop 360 has reached the required number.

[0057] Please see again Figure 7The exposure time control module 40 comprises a third D flip-flop 410, a right shift register 420, a left shift register 430 and a selector 440. The output end of the third D flip-flop 410 is connected with the input end of the right shift register 420, the input end of the left shift register 430 and the input end of the selector 440. The output end of the right shift register 420 and the output end of the left shift register 430 are connected with the input end of the selector 440. The output end of the selector 440 is connected with the input end of the third D flip-flop 410. The selection end of the selector 440 is connected with the output end of the gray scale statistical module 30 and the input end of the event quantity judgment module 20. The right shift register 420 is branch 1. The third D flip-flop 410 is directly connected with the selector 440 as branch 2. The left shift register 430 is branch 3.

[0058] In the embodiment, the selection end of the selector 440 receives 5-bit Flag signal data, which comprises a first judgment result, a second judgment result, a third judgment result, a first statistical result and a second statistical result. The first judgment result, the second judgment result, the third judgment result, the first statistical result and the second statistical result are all 1-bit data. The exposure event control module flexibly controls the exposure time according to the 3-bit judgment result and the 2-bit statistical result, so as to prevent overexposure or underexposure.

[0059] Specifically, when the value of the Flag signal data is 5’b10001, it indicates that the Flag_bright signal and the Flag_ON>>OFF signal are pulled high, and the selector 440 selects the data of branch 1 as the new exposure time data and stores it into the third D flip-flop group 410. When the value of the Flag signal data is 5’b01010, the Flag_dark signal and the Flag_ON<<OFF signal are pulled high, and the selector 440 selects the data of branch 3 as the new exposure time data and stores it into the third D flip-flop group 410. Except for the above two cases, the selector 440 selects the data of branch 2 as the new exposure time data and stores it into the third D flip-flop group 410.

[0060] In summary, the embodiment of the application uses the event statistical module to count ON events and OFF events, and then uses the event quantity judgment module to compare the number of ON events and OFF events and output a comparison result. The gray scale statistical module fuses the gray scale information of the statistical fusion visual sensor and outputs a statistical result. Finally, the exposure time control module determines whether to increase the exposure time, reduce the exposure time or keep unchanged according to the output of the event quantity judgment module and the gray scale statistical module, so as to prevent overexposure or underexposure caused by changes in external light intensity, and improve the imaging quality of the fusion visual sensor.

[0061] The above-described is only a preferred embodiment of the present application, of course, cannot be limited by this to the scope of the present application, the person skilled in the art can understand that the implementation of all or part of the above-mentioned embodiment process, and according to the equivalent changes made by the claims of the present application, still belong to the scope covered by the present application.

Claims

1. An adaptive exposure circuit for a fusion vision sensor, characterized by, include: Event statistics module, event quantity judgment module, exposure time control module, and grayscale statistics module; The event statistics module is used to count the light intensity increase events and light intensity decrease events generated by the fusion vision sensor, and output the statistical results to the event quantity judgment module. The event quantity judgment module is used to judge the statistical results and transmit the judgment results to the exposure time control module; The grayscale statistics module is used to collect grayscale information from the fusion vision sensor and transmit the statistical results to the exposure time control module. The exposure time control module is used to adjust the exposure time accordingly based on the judgment result and grayscale information; The event quantity determination module includes a first subtractor, a second subtractor, a first comparator, a second comparator, and an XOR gate; The first subtractor input and the second subtractor input are connected to the event statistics module; the first subtractor output is connected to the first comparator input; the second subtractor output is connected to the second comparator input; the first comparator output and the second comparator output are connected to the XOR gate input; the first comparator output, the second comparator output, and the XOR gate output are connected to the exposure time control module as the output of the event quantity judgment module.

2. The adaptive exposure circuit for a fusion vision sensor of claim 1, wherein, The event quantity judgment module includes a first threshold and a second threshold; when the number of light intensity increase events minus the number of light intensity decrease events is greater than or equal to the first threshold, the event quantity judgment module outputs a first judgment result; when the number of light intensity decrease events minus the number of light intensity increase events is greater than or equal to the second threshold, the event quantity judgment module outputs a second judgment result; when the number of light intensity increase events minus the number of light intensity decrease events is less than the first threshold and the number of light intensity decrease events minus the number of light intensity increase events is less than the second threshold, the event quantity judgment module outputs a third judgment result.

3. The adaptive exposure circuit for a fusion vision sensor of claim 1, wherein, The grayscale statistics module includes a third threshold, a fourth threshold, a fifth threshold, and a sixth threshold; when the grayscale information is less than the third threshold, the grayscale statistics module will determine that the grayscale information is low grayscale pixel information and count the number of low grayscale pixels. When the grayscale information is greater than the fourth threshold, the grayscale statistics module will determine that the grayscale information is high grayscale pixel information and count the number of low grayscale pixels. When the number of low grayscale pixels is greater than the fifth threshold, the first statistical result is output; when the number of high grayscale pixels is greater than the sixth threshold, the second statistical result is output. The third threshold is less than the fourth threshold.

4. The adaptive exposure circuit for a fusion vision sensor of claim 1, wherein, The other input of the first comparator is connected to the first threshold; the other input of the second comparator is connected to the second threshold.

5. The adaptive exposure circuit for a fusion vision sensor of claim 1, wherein, The grayscale statistics module includes: a third comparator, a fourth comparator, a fifth comparator, a sixth comparator, a first D flip-flop, a second D flip-flop, a first adder, and a second adder; The third comparator and the fourth comparator input end are connected with the gray information as the gray statistical module input end; the third comparator output end and the first D flip-flop output end are connected with the first adder input end; the first adder output end is connected with the first D flip-flop input end and the fifth comparator input end; the fourth comparator output end and the second D flip-flop output end are connected with the second adder input end; the second adder output end is connected with the second D flip-flop input end and the sixth comparator input end; the fifth comparator output end and the sixth comparator output end output the statistical result as the gray statistical module output end.

6. The adaptive exposure circuit for a fusion vision sensor of claim 5, wherein, The third comparator other input end is connected with the third threshold value; when the gray information is less than the third threshold value, the first D flip-flop storage data increases by 1; the fourth comparator other input end is connected with the fourth threshold value; when the gray information is greater than the fourth threshold value, the second D flip-flop storage data increases by 1; the fifth comparator other input end is connected with the fifth threshold value; the sixth comparator other input end is connected with the sixth threshold value.

7. The adaptive exposure circuit for a fusion vision sensor of claim 1, wherein, The exposure time control module comprises a third D flip-flop, a right shift register, a left shift register and a selector; The third D flip-flop output end is connected with the right shift register input end, the left shift register input end and the selector input end; the right shift register output end and the left shift register output end are connected with the selector input end; the selector output end is connected with the third D flip-flop input end; the selector selection end is connected with the gray statistical module output end and the event quantity judgment module input end as the exposure time control module input end.

8. The adaptive exposure circuit for a fused vision sensor of claim 1, wherein, The event statistical module comprises a first event buffer, a first adder group, a first accumulation register, a second event buffer, a second adder group and a second accumulation register; The first event buffer is used for storing the light intensity increase event generated by the fusion visual sensor, and the output end is connected with the first adder group input end; the first adder group is used for accumulating the light intensity increase event, and the output end is connected with the first accumulation register input end; the first accumulation register is used for storing the light intensity increase event statistical result and outputting the light intensity increase event statistical result to the event quantity judgment module.

9. The adaptive exposure circuit for a fusion vision sensor of claim 8, wherein, The second event buffer is used for storing the light intensity decrease event generated by the fusion visual sensor, and the output end is connected with the second adder group input end; the second adder group is used for accumulating the light intensity decrease event, and the output end is connected with the second accumulation register input end; the second accumulation register is used for storing the light intensity decrease event statistical result and outputting the light intensity decrease event statistical result to the event quantity judgment module.

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