CN114827467A - Event type image sensor and control method - Google Patents
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Abstract
Description
技术领域technical field
本发明属于计算机视觉技术领域,尤其涉及一种事件型图像传感器及控制方法。The invention belongs to the technical field of computer vision, and in particular relates to an event-type image sensor and a control method.
背景技术Background technique
传统相机,无论是CMOS传感器,还是CCD传感器,或是RGBD相机,是以恒定的频率拍摄获取图像。这样,即使帧率能够达到1KHz,那也具有1ms的延时。所以传统相机存在一定的延迟问题。随着时代的发展,出现了一种事件相机(Event-based Vision,EVS),事件相机是一种动态视觉传感器,其感测入射光的变化并基于光的变化生成事件,输出事件信号,具有帧率快、功率低等优点。Traditional cameras, whether CMOS sensors, CCD sensors, or RGBD cameras, capture images at a constant frequency. In this way, even if the frame rate can reach 1KHz, that also has a delay of 1ms. Therefore, traditional cameras have a certain delay problem. With the development of the times, an event camera (Event-based Vision, EVS) has emerged. The event camera is a dynamic vision sensor that senses changes in incident light and generates events based on changes in light, outputs event signals, and has The advantages of fast frame rate and low power.
然而,现有的事件相机,由于其集成电路生产过程中的工艺偏差,各子电路之间存在一些噪声、失调等因素,会导致事件信号输出错误。However, in the existing event camera, due to the process deviation in the production process of the integrated circuit, there are some factors such as noise and offset among the sub-circuits, which may cause the event signal output error.
发明内容SUMMARY OF THE INVENTION
本发明提供一种事件型图像传感器及控制方法,用以解决现有技术中事件信号输出不准确的技术问题。The present invention provides an event-type image sensor and a control method, which are used to solve the technical problem of inaccurate output of event signals in the prior art.
一方面本发明提供一种事件型图像传感器,应用于事件相机,所述事件型图像传感器包括:输入单元、斩波单元、比较单元以及读出单元,所述输入单元、所述斩波单元、所述比较单元以及所述读出单元依次连接;其中,In one aspect, the present invention provides an event-type image sensor, which is applied to an event camera. The event-type image sensor includes: an input unit, a chopper unit, a comparison unit, and a readout unit, the input unit, the chopper unit, The comparison unit and the readout unit are connected in sequence; wherein,
所述输入单元用于响应于入射光信号获取实时电压;the input unit is used for acquiring real-time voltage in response to the incident light signal;
所述斩波单元用于将所述实时电压与预设参考电压的差值电压作为输入电压,对所述输入电压与噪声电压进行频率分离,然后按照分离后的频率将所述噪声电压过滤后,得到输出电压;The chopper unit is configured to use the difference voltage between the real-time voltage and the preset reference voltage as the input voltage, separate the input voltage from the noise voltage in frequency, and then filter the noise voltage according to the separated frequency. , get the output voltage;
所述比较单元用于将所述输出电压与预设电压范围进行比较;the comparison unit is used for comparing the output voltage with a preset voltage range;
所述读出单元用于根据比较结果输出事件信号。The readout unit is used for outputting an event signal according to the comparison result.
第二方面,本发明提供一种事件型图像传感器控制方法,应用于事件相机,所述方法包括:In a second aspect, the present invention provides an event-based image sensor control method applied to an event camera, the method comprising:
响应于入射光信号获取实时电压;obtaining a real-time voltage in response to an incident light signal;
将所述实时电压与预设参考电压的差值电压作为输入电压,对所述输入电压与噪声电压进行频率分离,然后按照分离后的频率将所述噪声电压过滤后,得到输出电压;The difference voltage between the real-time voltage and the preset reference voltage is used as the input voltage, the frequency of the input voltage and the noise voltage is separated, and then the noise voltage is filtered according to the separated frequency to obtain an output voltage;
将所述输出电压与预设电压范围进行比较;comparing the output voltage to a preset voltage range;
根据比较结果输出事件信号。An event signal is output according to the comparison result.
从上述本发明实施例可知,本发明实施例通过将输入电压与噪声电压进行频率分离,再根据分离后的频率将噪声电压进行过滤,得到去除噪声电压的输出电压;由于输出电压为去除噪声电压后的电压,在根据对比结果输出事件信号时,使得输出的事件信号更加准确。It can be seen from the above-mentioned embodiments of the present invention that in the embodiments of the present invention, the frequency of the input voltage and the noise voltage is separated, and then the noise voltage is filtered according to the separated frequency to obtain an output voltage that removes the noise voltage; since the output voltage is the noise-removed voltage After the voltage, when the event signal is output according to the comparison result, the output event signal is more accurate.
附图说明Description of drawings
为了更清楚地说明本发明实施例或现有技术中的技术方案,下面将对实施例或现有技术描述中所需要使用的附图作简单地介绍,显而易见地,下面描述中的附图仅仅是本发明的一些实施例,对于本领域技术人员来讲,在不付出创造性劳动性的前提下,还可以根据这些附图获得其他的附图。In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention, and for those skilled in the art, other drawings can also be obtained from these drawings without any creative effort.
图1为本申请实施例中事件型图像传感器控制方法的流程示意图;1 is a schematic flowchart of a method for controlling an event-type image sensor in an embodiment of the present application;
图2为本申请实施例中事件型图像传感器的电路结构图;FIG. 2 is a circuit structure diagram of an event-type image sensor in an embodiment of the present application;
图3为本申请实施例中斩波单元的电路结构图;3 is a circuit structure diagram of a chopper unit in an embodiment of the application;
图4为本申请实施例中信号频率/斩波频率、输入电压和噪声电压的关系示意图;4 is a schematic diagram of the relationship between signal frequency/chopping frequency, input voltage and noise voltage in an embodiment of the application;
图5为本申请实施例中信号频率/斩波频率、中间电压信号的关系示意图;5 is a schematic diagram of the relationship between signal frequency/chopping frequency and intermediate voltage signal in an embodiment of the application;
图6为本申请实施例中信号频率/斩波频率、解调电压和噪声电压的关系示意图;6 is a schematic diagram of the relationship between signal frequency/chopping frequency, demodulation voltage and noise voltage in an embodiment of the present application;
图7为本申请实施例中信号频率/斩波频率、输出电压和噪声电压的关系示意图;7 is a schematic diagram of the relationship between signal frequency/chopping frequency, output voltage and noise voltage in an embodiment of the application;
图8为本申请实施例中输入电压与时间的关系示意图;8 is a schematic diagram of the relationship between input voltage and time in an embodiment of the application;
图9为本申请实施例中调制电压与时间的关系示意图;FIG. 9 is a schematic diagram of the relationship between modulation voltage and time in an embodiment of the present application;
图10为本申请实施例中解调电压与时间的关系示意图;10 is a schematic diagram of the relationship between demodulation voltage and time in an embodiment of the application;
图11为本申请实施例中输出电压与时间的关系示意图。FIG. 11 is a schematic diagram of the relationship between output voltage and time in an embodiment of the present application.
具体实施方式Detailed ways
为使得本发明的发明目的、特征、优点能够更加的明显和易懂,下面将结合本发明实施例中的附图,对本发明实施例中的技术方案进行清楚、完整地描述,显然,所描述的实施例仅仅是本发明一部分实施例,而非全部实施例。基于本发明中的实施例,本领域技术人员在没有做出创造性劳动前提下所获得的所有其他实施例,都属于本发明保护的范围。In order to make the purpose, features and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. The embodiments described above are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present invention.
在本发明实施例的描述中,需要理解的是,术语“第一”、“第二”仅用于描述目的,而不能理解为指示或暗示相对重要性或者隐含指明所指示的技术特征的数量。由此,限定有“第一”、“第二”的特征可以明示或者隐含地包括一个或者更多个该特征。在本发明实施例的描述中,“多个”的含义是两个或两个以上,除非另有明确具体的限定。In the description of the embodiments of the present invention, it should be understood that the terms "first" and "second" are only used for description purposes, and should not be interpreted as indicating or implying relative importance or implicitly indicating the indicated technical features. quantity. Thus, a feature defined as "first" or "second" may expressly or implicitly include one or more of that feature. In the description of the embodiments of the present invention, "plurality" means two or more, unless otherwise expressly and specifically defined.
在本发明实施例中,除非另有明确的规定和限定,术语“安装”、“相连”、“连接”、“固定”等术语应做广义理解,例如,可以是固定连接,也可以是可拆卸连接,或成一体;可以是机械连接,也可以是电连接;可以是直接相连,也可以通过中间媒介间接相连,可以是两个元件内部的连通或两个元件的相互作用关系。对于本领域的普通技术人员而言,可以根据具体情况理解上述术语在本发明实施例中的具体含义。In the embodiments of the present invention, unless otherwise expressly specified and limited, terms such as “installation”, “connection”, “connection”, and “fixation” should be understood in a broad sense. For example, it may be a fixed connection or a It can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal communication of the two elements or the interaction relationship between the two elements. Those of ordinary skill in the art can understand the specific meanings of the above terms in the embodiments of the present invention according to specific situations.
参阅图1,示出了本发明实施例的一种事件型图像传感器控制方法,应用于事件相机,所述方法包括:Referring to FIG. 1 , an event-based image sensor control method according to an embodiment of the present invention, applied to an event camera, is shown, and the method includes:
步骤S100、响应于入射光信号获取实时电压。Step S100, acquiring a real-time voltage in response to the incident light signal.
在示例性的实施例中,所述步骤S100具体包括:In an exemplary embodiment, the step S100 specifically includes:
响应于所述入射光信号生成光电流;将所述光电流转换成实时电压。generating a photocurrent in response to the incident light signal; converting the photocurrent to a real-time voltage.
本实施例中,事件相机为事件型图像传感器,事件型图像传感器包括由多个像素组成的像素阵列,像素阵列中每个像素包括有对应的像素传感器,像素传感器可采集入射光信号。通过图像传感器中的像素采集入射光信号,每个像素进行相应的采集,采集后的入射光信号通过光电转换元件进行光电转换,得到对应的电流值,对该电流值通过电流-电压转换元件进行电流-电压的转换,得到对应的实时电压,将光信号转变为电压信号便于数据计算。光电转换元件可以为光电二极管、光电晶体管、钳位光电二极管或任何其他类似进行光电转换的元器件。电流转电压元件的实现电路较常见,可采用分压器方法、霍尔传感器方法、积分电路方法等实现,在此不做赘述。In this embodiment, the event camera is an event-type image sensor, and the event-type image sensor includes a pixel array composed of a plurality of pixels, each pixel in the pixel array includes a corresponding pixel sensor, and the pixel sensor can collect incident light signals. The incident light signal is collected by the pixels in the image sensor, and each pixel is collected accordingly. The collected incident light signal is photoelectrically converted by the photoelectric conversion element to obtain the corresponding current value, and the current value is processed by the current-voltage conversion element. The current-voltage conversion can obtain the corresponding real-time voltage, and convert the optical signal into a voltage signal to facilitate data calculation. The photoelectric conversion element can be a photodiode, a phototransistor, a clamp photodiode, or any other similar components that perform photoelectric conversion. The realization circuit of the current-to-voltage element is relatively common, and can be realized by the voltage divider method, the Hall sensor method, the integrating circuit method, etc., which will not be repeated here.
步骤S120、将所述实时电压与预设参考电压的差值电压作为输入电压,对所述输入电压与对应的噪声电压进行频率分离,按照分离后的频率将所述噪声电压过滤后,得到输出电压。Step S120: Use the difference voltage between the real-time voltage and the preset reference voltage as the input voltage, separate the input voltage from the corresponding noise voltage in frequency, and filter the noise voltage according to the separated frequency to obtain an output Voltage.
本实施例中,通过第一斩波器根据预设调制信号对输入电压进行调制,对噪声电压不进行调制,再将调制后的输入电压与噪声电压一起进行放大,得到中间电压信号,最后通过相应的解调信号将中间电压信号中的调制电压解调,使中间电压信号中的调制电压与噪声电压进行频率分离,噪声电压为高频信号,解调后的调制电压为低频信号;再按照分离后的频率将噪声电压进行低通滤波,得到输出电压。In this embodiment, the first chopper modulates the input voltage according to the preset modulation signal, and does not modulate the noise voltage, and then amplifies the modulated input voltage together with the noise voltage to obtain an intermediate voltage signal. The corresponding demodulation signal demodulates the modulation voltage in the intermediate voltage signal, so that the modulation voltage in the intermediate voltage signal and the noise voltage are separated in frequency, the noise voltage is a high-frequency signal, and the demodulated modulation voltage is a low-frequency signal; The separated frequencies low-pass filter the noise voltage to obtain the output voltage.
本实施例中,所述步骤S120具体包括:In this embodiment, the step S120 specifically includes:
将所述实时电压与预设参考电压的差值电压作为输入电压,对所述输入电压调制后,与所述噪声电压同时进行频率放大,得到中间电压信号;将所述中间电压信号中的调制电压解调后进行低通滤波,将所述噪声电压过滤后得到输出电压。The difference voltage between the real-time voltage and the preset reference voltage is used as the input voltage, and after the input voltage is modulated, frequency amplification is performed simultaneously with the noise voltage to obtain an intermediate voltage signal; the modulation in the intermediate voltage signal is After the voltage demodulation, low-pass filtering is performed, and the output voltage is obtained after filtering the noise voltage.
本实施例中,作为优选的实施方式,所述步骤S120具体包括:In this embodiment, as a preferred implementation manner, the step S120 specifically includes:
将所述实时电压与预设参考电压的差值电压作为输入电压进行调制;将调制后的所述输入电压以及所述噪声电压同时进行频率放大,得到中间电压信号;所述中间电压信号中的调制电压解调;对解调后的所述中间电压信号进行低通滤波,将所述噪声电压过滤后得到输出电压。The difference voltage between the real-time voltage and the preset reference voltage is used as an input voltage for modulation; the modulated input voltage and the noise voltage are simultaneously amplified in frequency to obtain an intermediate voltage signal; Modulation voltage demodulation; low-pass filtering is performed on the demodulated intermediate voltage signal, and an output voltage is obtained after filtering the noise voltage.
本实施例中,输入电压伴随有噪声电压,第一斩波器可以根据预设调制信号对输入电压调制,输出调制后的输入电压。再通过放大器将调制后的输入电压与噪声电压同时进行频率放大,得到中间电压信号,此时噪声电压被放大为高频电压。然后通过第二斩波器将中间电压信号中的调制电压解调,即将调制电压解调为低频信号。最后,通过低通滤波器后将解调后调制电压与噪声电压一起进行低通滤波,滤除噪声电压,得到输出电压。In this embodiment, the input voltage is accompanied by a noise voltage, and the first chopper can modulate the input voltage according to the preset modulation signal, and output the modulated input voltage. Then, the modulated input voltage and the noise voltage are simultaneously amplified in frequency by the amplifier to obtain an intermediate voltage signal. At this time, the noise voltage is amplified into a high-frequency voltage. Then, the modulation voltage in the intermediate voltage signal is demodulated by the second chopper, that is, the modulation voltage is demodulated into a low frequency signal. Finally, after passing through the low-pass filter, low-pass filtering is performed on the demodulated modulation voltage together with the noise voltage, and the noise voltage is filtered out to obtain the output voltage.
步骤S140、将所述输出电压与预设电压范围进行比较。Step S140, compare the output voltage with a preset voltage range.
本实施例中,通过将去除噪声电压的输出电压的电压值与预设电压范围进行比较,以输出较为准确的事件信号。In this embodiment, a more accurate event signal is output by comparing the voltage value of the output voltage from which the noise voltage is removed with a preset voltage range.
步骤S160、根据比较结果输出事件信号。Step S160, output an event signal according to the comparison result.
本实施例中,将输出电压与预设电压范围进行比较,当输出电压大于该预设电压范围时,像素采集的入射光信号发生了UP事件,即像素采集的入射光强度变强,产生UP事件信号;当输出电压小于该预设电压范围时,像素采集的入射光信号发生了DN事件,即像素采集的入射光强度变弱,产生DN事件信号。假设预设电压范围为(-0.1V,0.1V),当输出电压为0.2V时,比较结果为(1,0),表示0.2V大于0.1V,则输出UP事件信号;当输出电压为-0.2V时,比较结果为(0,1),表示-0.2V小于-0.1V,则输出DN事件信号;当输出电压为0.05V时,比较结果为(0,0),表示没有生成事件,不输出事件信号,继续采集实时电压。当然,在实际应用中,不排除系统可能出现错误,输出(1,1),这种事件信号通常为噪声信号,而本实施例中去除了噪声电压,减少了系统失误率。由于该输出电压消除了偏移电压,将该输出电压与预设电压范围进行比较时,比较的结果较为准确,提高了输出的事件信号的准确性。In this embodiment, the output voltage is compared with a preset voltage range. When the output voltage is greater than the preset voltage range, an UP event occurs in the incident light signal collected by the pixel, that is, the intensity of the incident light collected by the pixel becomes stronger, resulting in an UP event. Event signal; when the output voltage is less than the preset voltage range, a DN event occurs in the incident light signal collected by the pixel, that is, the intensity of the incident light collected by the pixel becomes weaker, and a DN event signal is generated. Assuming that the preset voltage range is (-0.1V, 0.1V), when the output voltage is 0.2V, the comparison result is (1, 0), indicating that 0.2V is greater than 0.1V, the UP event signal is output; when the output voltage is - When the output voltage is 0.2V, the comparison result is (0, 1), indicating that -0.2V is less than -0.1V, and the DN event signal is output; when the output voltage is 0.05V, the comparison result is (0, 0), indicating that no event is generated, Do not output event signal, continue to collect real-time voltage. Of course, in practical applications, it is not ruled out that the system may have errors and output (1, 1). This event signal is usually a noise signal. In this embodiment, the noise voltage is removed to reduce the system error rate. Since the output voltage eliminates the offset voltage, when the output voltage is compared with the preset voltage range, the comparison result is more accurate, which improves the accuracy of the output event signal.
本实施例中,所述事件型图像传感器控制方法还包括对电容中存储的预设参考电压进行更新,若当前时刻采集的实时电压与预设参考电压根据步骤S120至步骤S160处理后输出了事件信号,将当前时刻的实时电压作为更新的预设参考电压存储在电容中。若在预设采集时间段内采集的实时电压根据步骤S120至步骤S160处理后都没有输出事件信号,则进行开关闭合再断开的操作,重置电容中的预设参考电压;再根据更新的预设参考电压重新执行步骤S100至步骤S160以输出事件信号。In this embodiment, the event-based image sensor control method further includes updating the preset reference voltage stored in the capacitor. If the real-time voltage collected at the current moment and the preset reference voltage are processed according to steps S120 to S160, an event is output signal, the real-time voltage at the current moment is stored in the capacitor as an updated preset reference voltage. If the real-time voltage collected in the preset collection time period does not output an event signal after processing according to steps S120 to S160, the switch is closed and then opened to reset the preset reference voltage in the capacitor; and then according to the updated Steps S100 to S160 are re-executed to output the event signal for the preset reference voltage.
本实施例中,解调后的调制电压经过低通滤波器进行滤波处理后,滤除了噪声电压,有效去除了高频噪声。输入电压在第一斩波器与第二斩波器调制解调后与噪声电压进行频率分离,放大时将噪声电压放大为高频信号,经过低通滤波后进行滤除,失调电压在调制解调处理中也进行消除。In this embodiment, after the demodulated modulation voltage is filtered by a low-pass filter, the noise voltage is filtered out, and the high-frequency noise is effectively removed. The input voltage is frequency separated from the noise voltage after modulation and demodulation by the first chopper and the second chopper. During amplification, the noise voltage is amplified into a high-frequency signal, which is filtered out after low-pass filtering. The offset voltage is modulated and demodulated. It is also eliminated during the adjustment process.
本实施例中,输入电压为实时电压与预设参考电压的差值电压,输入电压在传输过程中伴随有噪声电压,在输入电压进行调制时,没有对噪声电压进行调制处理,噪声电压与调制后的输入电压一起输入至放大器中,调制后的输入电压与噪声电压被放大为高频信号,得到中间电压信号。中间电压信号经过解调处理,由于噪声电压没有经过调制,只对中间电压信号中的调制电压进行解调处理,最后解调后的调制信号与放大后的噪声电压都经过低通滤波,得到输出电压,而此时的噪声电压由于为高频信号,可以通过低通滤波器滤除,从而能够滤除偏移电压和高频噪声。In this embodiment, the input voltage is the difference voltage between the real-time voltage and the preset reference voltage. The input voltage is accompanied by noise voltage during the transmission process. When the input voltage is modulated, the noise voltage is not modulated. The noise voltage and modulation The modulated input voltage and the noise voltage are amplified into a high-frequency signal to obtain an intermediate voltage signal. The intermediate voltage signal undergoes demodulation processing. Since the noise voltage is not modulated, only the modulation voltage in the intermediate voltage signal is demodulated. Finally, the demodulated modulation signal and the amplified noise voltage are subjected to low-pass filtering to obtain the output. Since the noise voltage at this time is a high-frequency signal, it can be filtered out by a low-pass filter, so that the offset voltage and high-frequency noise can be filtered out.
从上述本发明实施例可知,本发明实施例通过将输入电压进行频率调制,将输入电压与与噪声电压的频率进行分离,以便于去除失调电压;再对调制后的输入电压以及噪声电压进行放大后,将噪声电压转变为高频信号,通过滤波处理可以滤除;然后将中间电压信号进行解调处理,将中间电压信号中的调制电压解调为低频信号,与放大为高频信号的噪声电压进行频率分离,最后经过滤波器将放大为高频信号的噪声电压进行滤除;由于输出电压为去除噪声电压后的电压,在根据对比结果输出事件信号时,使得输出的事件信号更加准确。It can be seen from the above-mentioned embodiments of the present invention that in the embodiments of the present invention, the frequency of the input voltage is modulated to separate the input voltage from the frequency of the noise voltage, so as to facilitate the removal of the offset voltage; and then the modulated input voltage and the noise voltage are amplified. Then, the noise voltage is converted into a high-frequency signal, which can be filtered out by filtering; then the intermediate voltage signal is demodulated, and the modulation voltage in the intermediate voltage signal is demodulated into a low-frequency signal, and the noise amplified into a high-frequency signal The voltage is separated in frequency, and finally the noise voltage amplified into a high-frequency signal is filtered out by a filter; since the output voltage is the voltage after removing the noise voltage, when the event signal is output according to the comparison result, the output event signal is more accurate.
请再次参阅图2,示出了本发明实施例的一种事件型图像传感器20,应用于事件相机,所述事件型图像传感器20包括:输入单元21、斩波单元22、比较单元24以及读出单元25,所述输入单元21、所述斩波单元22、所述比较单元24以及所述读出单元25依次连接。具体描述如下:Please refer to FIG. 2 again, which shows an event-
所述输入单元21用于响应于入射光信号获取实时电压。The input unit 21 is used to acquire real-time voltage in response to the incident light signal.
在示例性地实施例中,所述输入单元21包括转换元件210、开关211与电容212,所述开关211连接于所述转换元件210的第一输出端与所述差分单元23的第一输入端之间,所述开关211与所述差分单元23的第一输入端的连接端连接所述电容212的非接地端,所述转换元件210的第二输出端与所述差分单元23的第二输入端连接;In an exemplary embodiment, the input unit 21 includes a
所述转换元件210用于将入射光信号转换为实时电压;The
所述电容212用于在所述开关211从闭合状态切换到断开状态时更新所述预设参考电压。The
在示例性地实施例中,所述转换元件210包括光电转换元件与电流电压转换元件,所述光电转换元件的输出端与所述电流电压转换元件的输入端连接,所述电流电压转换元件的第一输出端与所述开关211连接,所述电流电压转换元件的第二输出端与述差分单元23的第二输入端连接;In an exemplary embodiment, the
所述光电转换元件用于响应于所述入射光信号生成光电流;the photoelectric conversion element is used to generate a photocurrent in response to the incident light signal;
所述电流电压转换元件用于将所述光电流转换成所述实时电压。The current-to-voltage conversion element is used to convert the photocurrent into the real-time voltage.
所述斩波单元22用于将所述实时电压与预设参考电压的差值电压作为输入电压,对所述输入电压与对应的噪声电压进行频率分离,按照分离后的频率将所述噪声电压过滤后,得到输出电压。The
在示例性地实施例中,所述斩波单元22包括第一斩波单元、第二斩波单元,所述第一斩波单元连接于所述输入单元21与所述第二斩波单元之间;In an exemplary embodiment, the
所述第一斩波单元用于将所述实时电压与预设参考电压的差值电压作为输入电压,对所述输入电压调制后,与所述噪声电压同时进行频率放大,得到所述中间电压信号;The first chopper unit is configured to use the difference voltage between the real-time voltage and the preset reference voltage as the input voltage, and after modulating the input voltage, perform frequency amplification simultaneously with the noise voltage to obtain the intermediate voltage Signal;
所述第二斩波单元用于将所述中间电压信号中的调制电压解调后进行低通滤波,将所述噪声电压过滤后得到输出电压。The second chopper unit is used for demodulating the modulation voltage in the intermediate voltage signal and performing low-pass filtering, and filtering the noise voltage to obtain an output voltage.
在示例性地实施例中,参阅图3,所述第一斩波单元包括第一斩波器221与放大器222,所述第一斩波器221的输入端与所述输入单元21的输出端连接,所述第一斩波器221的输出端与所述放大器222的输入端连接,所述放大器222的输出端连接所述第二斩波单元的输入端;In an exemplary embodiment, referring to FIG. 3 , the first chopper unit includes a
所述第一斩波器221用于将所述实时电压与预设参考电压的差值电压作为输入电压进行调制;The
所述放大器222用于将调制后的所述输入电压以及所述噪声电压同时进行频率放大,得到中间电压信号。The
在示例性地实施例中,所述第二斩波单元包括第二斩波器223与低通滤波器224,所述第二斩波器223的输入端连接所述放大器222的输出端,所述第二斩波器223的输出端连接所述低通滤波器224的输入端,所述低通滤波器224的输出端连接所述比较单元24;In an exemplary embodiment, the second chopper unit includes a
所述第二斩波器223用于将所述中间电压信号中的调制电压解调;the
所述低通滤波器2231用于对解调后的所述中间电压信号进行低通滤波,将所述噪声电压过滤后得到输出电压。The low-pass filter 2231 is used for low-pass filtering the demodulated intermediate voltage signal, and filtering the noise voltage to obtain an output voltage.
所述比较单元24用于将所述输出电压与预设电压范围进行比较。The comparison unit 24 is used for comparing the output voltage with a preset voltage range.
本实施例中,比较单元24可以为处理器或控制器,通过处理器将输出电压与预设电压范围进行比较。In this embodiment, the comparison unit 24 may be a processor or a controller, and the processor compares the output voltage with a preset voltage range.
所述读出单元25用于根据比较结果输出事件信号。The readout unit 25 is used for outputting an event signal according to the comparison result.
本实施例中,当输出电压大于该预设电压范围时,像素采集的入射光信号发生了UP事件,即像素采集的入射光强度变强,产生UP事件信号;当输出电压小于该预设电压范围时,像素采集的入射光信号发生了DN事件,即像素采集的入射光强度变弱,产生DN事件信号。由于该输出电压消除了噪声电压,将该输出电压与预设电压范围进行比较时,比较的结果较为准确,提高了输出的事件信号的准确性。In this embodiment, when the output voltage is greater than the preset voltage range, an UP event occurs in the incident light signal collected by the pixel, that is, the intensity of the incident light collected by the pixel becomes stronger, and an UP event signal is generated; when the output voltage is less than the preset voltage When the range is in the range, a DN event occurs in the incident light signal collected by the pixel, that is, the intensity of the incident light collected by the pixel becomes weaker, and a DN event signal is generated. Since the output voltage eliminates the noise voltage, when the output voltage is compared with the preset voltage range, the comparison result is more accurate, which improves the accuracy of the output event signal.
在示例性地实施例中,所述事件型图像传感器还包括:控制器,控制器也可以为比较单元中的处理器。控制器发送控制信号给输入单元21、斩波单元22、比较单元24以及读出单元25,以使输入单元21、斩波单元22、比较单元24以及读出单元25分别根据控制信号进行相应的操作。In an exemplary embodiment, the event-type image sensor further includes: a controller, which may also be a processor in the comparison unit. The controller sends control signals to the input unit 21 , the
本实施例中,输入电压在传输过程中伴随有低频的噪声电压,在输入电压输入至第一斩波器中进行调制,噪声电压不进行调制,噪声电压、调制后的输入电压一起输入至放大器中,噪声电压与调制后的输入电压被放大为高频信号,即中间电压信号。中间电压信号经第二斩波器进行解调,对中间电压信号的调制电压进行解调,而放大后的噪声电压不需要进行解调,将调制电压解调为低频信号,从而将调制电压的频率与放大后的噪声电压的频率进行分离;最后经过低通滤波,得到输出电压,滤波前的噪声电压由于为高频信号,可以通过低通滤波器滤除,从而能够滤除高频噪声。In this embodiment, the input voltage is accompanied by a low-frequency noise voltage during the transmission process, and the input voltage is input to the first chopper for modulation, the noise voltage is not modulated, and the noise voltage and the modulated input voltage are input to the amplifier together , the noise voltage and the modulated input voltage are amplified into a high-frequency signal, that is, an intermediate voltage signal. The intermediate voltage signal is demodulated by the second chopper, and the modulation voltage of the intermediate voltage signal is demodulated, and the amplified noise voltage does not need to be demodulated, and the modulation voltage is demodulated into a low-frequency signal, so that the modulation voltage is demodulated. The frequency is separated from the frequency of the amplified noise voltage; finally, the output voltage is obtained through low-pass filtering. Since the noise voltage before filtering is a high-frequency signal, it can be filtered by a low-pass filter, so that high-frequency noise can be filtered out.
在示例性地实施例中,所述事件型图像传感器还包括:差分单元23,所述差分单元23的输入端与所述输入单元21的输出端连接,所述差分单元23的输出端与所述斩波单元22的输入端连接;In an exemplary embodiment, the event-type image sensor further includes: a
所述差分单元23用于将所述实时电压与预设参考电压作差,得到所述差值电压。The
在示例性地实施例中,应用于事件相机,所述事件型图像传感器包括:输入单元21、差分单元23、斩波单元22、比较单元24以及读出单元25,所述输入单元21、所述差分单元23、所述斩波单元22、所述比较单元24以及所述读出单元25依次连接;其中,In an exemplary embodiment, applied to an event camera, the event-type image sensor includes: an input unit 21 , a
所述输入单元21用于响应于入射光信号获取实时电压;The input unit 21 is used for acquiring real-time voltage in response to the incident light signal;
所述差分单元23用于将所述实时电压与预设参考电压作差,得到所述差值电压;The
所述斩波单元22用于将所述差值电压作为输入电压,对所述输入电压与对应的噪声电压进行频率分离,按照分离后的频率将所述噪声电压过滤后,得到输出电压;The
所述比较单元24用于将所述输出电压与预设电压范围进行比较;The comparison unit 24 is used for comparing the output voltage with a preset voltage range;
所述读出单元25用于根据比较结果输出事件信号。The readout unit 25 is used for outputting an event signal according to the comparison result.
在本实施例中,输出电压的电压值处于预设电压范围内,表示没有输出事件信号,需要再继续采集实时电压,输出的是有效的事件信号时,将当前的实时电压存入电容中作为预设参考电压,此时开关处于断开状态,重新执行步骤S100至步骤S160的操作。In this embodiment, the voltage value of the output voltage is within the preset voltage range, indicating that no event signal is output, and it is necessary to continue to collect real-time voltage. When the output is a valid event signal, the current real-time voltage is stored in the capacitor as The reference voltage is preset, and the switch is in an off state at this time, and the operations from step S100 to step S160 are performed again.
在本实施例中,若在预设采集时间段内采集的实时电压根据步骤S120至步骤S160处理后都没有输出事件信号,则进行开关闭合再断开的操作,重置电容中的预设参考电压;再根据更新的预设参考电压重新执行步骤S100至步骤S160输出事件信号。In this embodiment, if no event signal is output after the real-time voltage collected in the preset collection time period is processed according to steps S120 to S160, the switch is closed and then opened to reset the preset reference in the capacitor. voltage; and then perform steps S100 to S160 again to output an event signal according to the updated preset reference voltage.
请再次参阅图2,示出了本发明实施例的一种事件型图像传感器30的电路图。该电路图包括:差分单元23、转换元件210、开关211、电容212、斩波单元22、比较单元24、读出单元25。Please refer to FIG. 2 again, which shows a circuit diagram of an event-type image sensor 30 according to an embodiment of the present invention. The circuit diagram includes: a
差分单元23的输入端与转换元件210的输出端连接,差分单元23的输出端与斩波单元22的输入端连接;转换元件210用于对入射光信号对应的电流进行转换,得到入射光信号对应的实时电压;差分单元23用于将实时电压与预设参考电压作差,得到差值电压。The input end of the
请参阅图3,斩波单元22包括第一斩波器221、第二斩波器223、放大器222与低通滤波器224。在t1时刻进行入射光信号的采样,入射光信号对应的电压为V1,将开关211断开,电压V1存入电容212中记入为预设参考电压V1(即,节点A的电压为V1);在t2时刻采集的入射光信号对应的实时电压为V2(即,节点B的电压为V2),即输入电压为V2-V1。Please refer to FIG. 3 , the
转换元件210的第二输出端B连接差分单元23的第二输入端,差分单元23的输出端连接第一斩波器221的输入端,转换元件210的第一输出端连接开关211的一端,开关211的另一端连接电容212的一端与差分单元23的第一输入端,电容212的另一端接地。第一斩波器221的输出端连接放大器222,放大器222的输出端连接第二斩波器223的输入端,第二斩波器223的输出端连接低通滤波器224,低通滤波器224的输出端连接处理器或者控制器(图中未示出)。The second output end B of the
本实施例中,第一斩波器221对差分单元23的输出的差值电压作为输入电压进行调制,以将输入电压与噪声电压的频率进行分离。In this embodiment, the
放大器222对调制后的输入电压与噪声电压一起进行放大,得到中间电压信号。再通过第二斩波器223根据预设解调信号对中间电压信号进行解调处理。低通滤波器224对解调后的调制信号与放大后的噪声电压进行低通滤波,以去除噪声电压,得到输出电压。第一斩波器221与第二斩波器223的调制解调处理,用以去除偏移电压。The
本实施例中,示例性的描述斩波单元22的原理,具体如下:In this embodiment, the principle of the
假设当前信号电压(Vsignal)和噪声电压(Vnoise)分别与信号频率(f)/斩波频率(fchop)的关系如图4所示,斩波频率(fchop)为斩波器的工作频率,信号频率(f)为信号电压(Vsignal)的频率,可以理解为,当前信号电压为实时电压。通过第一斩波器221对输入电压进行调制处理,而噪声没有经过调制只经过放大器222,调制后的输入电压与噪声电压一起经过放大器222进行放大,信号电压(Vsignal)和噪声电压(Vnoise)的关系如图5所示,可以理解为,信号电压为中间电压信号,斩波频率为第一斩波器的工作频率。而后信号电压(Vsignal)噪声电压(Vnoise)一起经过第二斩波器223,信号电压(Vsignal)和噪声电压(Vnoise)的关系如图6所示,可以理解为,信号电压为经过解调后的调制信号。最后信号电压(Vsignal)和噪声电压(Vsignal)经过低通滤波器,其噪声电压(Vnoise)由于是高频信号,可以通过低通滤波器224滤除,输出电压Vout,如图7所示,可以理解为,输入电压为解调电压,斩波频率为第二斩波器的工作频率。由此实现了斩波单元22的对电压的调制与解调,从而能够交替改变信号电压(Vsignal)和噪声电压(Vnoise)的频率,以滤除信号电压中的偏移电压和高频噪声。Assume that the relationship between the current signal voltage (V signal ) and the noise voltage (V noise ) and the signal frequency (f)/chopping frequency (f chop ) are shown in FIG. 4 , and the chopping frequency (f chop ) is the The working frequency, the signal frequency (f) is the frequency of the signal voltage (V signal ), which can be understood as the current signal voltage is the real-time voltage. The input voltage is modulated by the
示例性地说明时间(t)与输入电压(Vin)的关系,当输入电压(Vin)经过第一斩波器,其输入电压(Vin)调制后,时间(t)与输入电压(Vin)如图8所示,此时的输入电压为调制后的输入电压。然后输入电压(Vin)经过放大器,其输入电压(Vin)被放大后,时间(t)与输入电压(Vin),如图9所示,该输入电压为调制电压。接着输入电压(Vin)经过第二斩波器,其输入电压(Vin)解调后,时间(t)与输入电压(Vin)如图10所示,该输入电压为解调后的调制信号,即解调电压。最后输入电压(Vin)通过低通滤波器,时间(t)与输入电压(Vin)如图11所示,从而输出如图11所示的输出电压Vout。The relationship between the time (t) and the input voltage (V in ) is exemplarily explained. When the input voltage (V in ) is modulated by the first chopper, the time (t) is related to the input voltage (V in ) after the input voltage (V in ) is modulated. V in ) as shown in Figure 8, the input voltage at this time is the modulated input voltage. Then the input voltage (V in ) passes through the amplifier, and after the input voltage (V in ) is amplified, time (t) and the input voltage (V in ), as shown in FIG. 9 , the input voltage is the modulation voltage. Then the input voltage (V in ) passes through the second chopper, and after the input voltage (V in ) is demodulated, the time (t) and the input voltage (V in ) are shown in FIG. 10 , and the input voltage is the demodulated Modulate the signal, i.e. the demodulated voltage. Finally, the input voltage (V in ) passes through the low-pass filter, and the time (t) and the input voltage (V in ) are shown in FIG. 11 , thereby outputting the output voltage V out shown in FIG. 11 .
在现有的去除失调的方案中,由于在传统的事件相机中,通过放大器输入等效失调校正后电压余量表达式如下:In the existing offset removal scheme, since in the traditional event camera, the voltage headroom expression after the equivalent offset correction through the amplifier input is as follows:
其中,Voffset-residue表示校正后的电压余量,A表示放大倍数。Among them, V offset-residue represents the voltage margin after correction, and A represents the magnification.
这种方案会需要高增益的放大器,才能减小随机失调电压的影响,而在图像传感器的每个像素内集成一个高增益放大器是非常难以实现的,另外高增益放大器会导致功耗高,采样速率低。在本申请中,通过利用斩波单元的调制解调原理简化了消去固有随机失调存储的步骤,具体为,通过斩波单元将输入电压与伴随的噪声电压进行频率分离,并按照分离后的频率将噪声电压过滤,得到输出电压,即无需使用高增益放大器,实现集成大规模高质量、高分辨率、功耗低、帧率高的事件型像素。This solution requires a high-gain amplifier to reduce the effect of random offset voltage, and it is very difficult to integrate a high-gain amplifier in each pixel of the image sensor. In addition, a high-gain amplifier will lead to high power consumption, sampling rate is low. In the present application, the step of eliminating inherent random offset storage is simplified by using the modulation and demodulation principle of the chopper unit. Specifically, the frequency of the input voltage and the accompanying noise voltage is separated by the chopper unit, and the frequency after separation Filter the noise voltage to obtain the output voltage, that is, without using a high-gain amplifier, to realize the integration of large-scale event-type pixels with high quality, high resolution, low power consumption, and high frame rate.
以上为对本发明所提供的事件型图像传感器及控制方法的描述,对于本领域的技术人员,依据本发明实施例的思想,在具体实施方式及应用范围上均会有改变之处,综上,本说明书内容不应理解为对本发明的限制。The above is a description of the event-type image sensor and the control method provided by the present invention. For those skilled in the art, according to the idea of the embodiment of the present invention, there will be changes in the specific implementation and application scope. In conclusion, The contents of this specification should not be construed as limiting the present invention.
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CN115480178A (en) * | 2022-10-20 | 2022-12-16 | 迈巨微(上海)电子技术有限公司 | High-voltage series battery management system and chip |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH09261474A (en) * | 1996-03-19 | 1997-10-03 | Sharp Corp | Image reader and adjusting method for the same |
US20150069255A1 (en) * | 2013-09-06 | 2015-03-12 | Analogic Corporation | Noise discrimination in photon counting system |
JP2017191518A (en) * | 2016-04-14 | 2017-10-19 | 旭化成エレクトロニクス株式会社 | Reference voltage generation circuit and signal processing system |
CN109239403A (en) * | 2018-10-17 | 2019-01-18 | 西北工业大学 | A kind of single device virtual accelerometer and its implementation based on time measurement |
CN113647095A (en) * | 2019-03-27 | 2021-11-12 | 苹果公司 | Sensor system architecture with feedback loop and multiple power states |
CN114252160A (en) * | 2020-09-22 | 2022-03-29 | 无锡华润上华科技有限公司 | Analog-to-digital converter and thermopile array |
-
2022
- 2022-04-22 CN CN202210432649.5A patent/CN114827467B/en active Active
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH09261474A (en) * | 1996-03-19 | 1997-10-03 | Sharp Corp | Image reader and adjusting method for the same |
US20150069255A1 (en) * | 2013-09-06 | 2015-03-12 | Analogic Corporation | Noise discrimination in photon counting system |
JP2017191518A (en) * | 2016-04-14 | 2017-10-19 | 旭化成エレクトロニクス株式会社 | Reference voltage generation circuit and signal processing system |
CN109239403A (en) * | 2018-10-17 | 2019-01-18 | 西北工业大学 | A kind of single device virtual accelerometer and its implementation based on time measurement |
CN113647095A (en) * | 2019-03-27 | 2021-11-12 | 苹果公司 | Sensor system architecture with feedback loop and multiple power states |
CN114252160A (en) * | 2020-09-22 | 2022-03-29 | 无锡华润上华科技有限公司 | Analog-to-digital converter and thermopile array |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN115480178A (en) * | 2022-10-20 | 2022-12-16 | 迈巨微(上海)电子技术有限公司 | High-voltage series battery management system and chip |
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