CN112526485B - Fault detection method, device, equipment, and storage medium - Google Patents

Abstract

The embodiment of the application discloses a fault detection method, a fault detection device, equipment and a storage medium, wherein the method comprises the following steps: receiving an opening instruction, wherein the opening instruction is used for indicating to open a ranging module of the electronic equipment; responding to the starting instruction, and before controlling a light wave emitter in the ranging module to emit working pulses at first regular intervals, controlling the light wave emitter to emit at least one test pulse so as to perform fault detection on the ranging module and obtain a detection result; the working pulse is used for measuring the distance between the ranging module and the target object; and controlling the working state of the ranging module according to the detection result.

Description

Fault detection method, device, equipment, and storage medium

Technical Field

The embodiments of the present application relate to electronic technology, and relate to but are not limited to fault detection methods and devices, equipment, and storage media.

Background technique

At present, the time of flight (TOF) ranging method is widely used in somatosensory interaction and control, three-dimensional (3D) object recognition and perception, intelligent environment perception, and dynamic map construction. Electronic devices can use the TOF ranging module to determine the distance to the target object. The specific method is: control the laser transmitter in the TOF ranging module to emit laser working pulses, and after receiving the laser reflected by the target object, the distance to the target object is determined by calculating the phase difference between the laser emission time and the reception time.

However, if a component in the TOF ranging module fails, the laser emitted by the laser transmitter may cause certain damage to human eyes and skin. Therefore, it is of great significance to perform fault detection on the TOF ranging module to reduce the risk of TOF ranging module damaging human eyes and skin.

Summary of the invention

In view of this, the embodiments of the present application provide a fault detection method and apparatus, a device, and a storage medium. The technical solution of the embodiments of the present application is implemented as follows:

In a first aspect, an embodiment of the present application provides a fault detection method, the method comprising: receiving a start-up instruction, the start-up instruction being used to instruct to turn on a ranging module of an electronic device; in response to the start-up instruction, before controlling a light wave transmitter in the ranging module to transmit a working pulse at a first regular interval, controlling the light wave transmitter to transmit at least one test pulse to perform fault detection on the ranging module and obtain a detection result; wherein the working pulse is used to measure the distance between the ranging module and a target object; and according to the detection result, controlling the working state of the ranging module.

In a second aspect, an embodiment of the present application provides a fault detection device, comprising: a receiving module, configured to receive a start-up instruction, wherein the start-up instruction is used to instruct to turn on a ranging module of the device; a control module, configured to respond to the start-up instruction, and before controlling the light wave transmitter in the ranging module to transmit a working pulse at a first regular interval, control the light wave transmitter to transmit at least one test pulse to perform fault detection on the ranging module and obtain a detection result; wherein the working pulse is used to measure the distance between the ranging module and a target object; and the control module is further configured to control the working state of the ranging module according to the detection result.

In a third aspect, an embodiment of the present application provides an electronic device, including a memory and a processor, wherein the memory stores a computer program that can be run on the processor, and when the processor executes the program, the steps in the fault detection method provided in the embodiment of the present application are implemented.

In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps in the fault detection method provided in the embodiment of the present application.

In an embodiment of the present application, after receiving the start-up instruction, in response to the start-up instruction, before controlling the light wave transmitter in the ranging module to transmit working pulses at a first regular interval, the light wave transmitter is controlled to transmit at least one test pulse to perform fault detection on the ranging module to obtain a detection result; based on the detection result, the working state of the ranging module is controlled; in this way, the risk of light waves causing damage to human eyes and skin can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1A is a schematic diagram of the structure of a TOF ranging module according to an embodiment of the present application;

FIG1B is a schematic diagram of the structure of an infrared transmitting unit in a TOF ranging module according to an embodiment of the present application;

FIG2 is a schematic diagram of an implementation flow of a fault detection method according to an embodiment of the present application;

FIG3A is a schematic diagram of a pulse signal according to an embodiment of the present application;

FIG3B is a schematic diagram of a signal of transmitting a working pulse according to a first rule in an embodiment of the present application;

FIG4 is a schematic diagram of an implementation flow of another fault detection method according to an embodiment of the present application;

FIG5 is a schematic diagram of an implementation flow of another fault detection method according to an embodiment of the present application;

FIG6 is a schematic diagram of a process flow of implementing yet another fault detection method according to an embodiment of the present application;

FIG7 is a schematic diagram of another pulse signal according to an embodiment of the present application;

FIG8 is a schematic diagram of another pulse signal according to an embodiment of the present application;

FIG9 is a schematic diagram of an implementation flow of another fault detection method according to an embodiment of the present application;

FIG10 is a schematic diagram of another pulse signal according to an embodiment of the present application;

FIG11 is a schematic diagram of a method for detecting whether a diffusion sheet has fallen off according to an embodiment of the present application;

FIG12 is a schematic diagram of the structure of a fault detection device according to an embodiment of the present application;

FIG. 13 is a schematic diagram of a hardware entity of an electronic device according to an embodiment of the present application.

Detailed ways

In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the specific technical scheme of the present application will be further described in detail below in conjunction with the drawings in the embodiments of the present application. The following embodiments are used to illustrate the present application, but are not used to limit the scope of the present application.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

In the following description, reference is made to “some embodiments”, which describe a subset of all possible embodiments, but it will be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

It should be pointed out that the terms "first\second\third" involved in the embodiments of the present application are merely used to distinguish different objects and do not represent a specific ordering of the objects. It can be understood that "first\second\third" can be interchanged in a specific order or sequence where permitted, so that the embodiments of the present application described here can be implemented in an order other than that illustrated or described here.

First, taking the distance measurement module as a TOF distance measurement module as an example, the structure and working principle of the TOF distance measurement module are described. As shown in FIG1A , the module 10 includes an infrared transmitting unit 11, an infrared receiving unit 12 and a controller 15; wherein the controller 15 controls the infrared transmitting unit 11 to emit modulated near-infrared light 13, which is projected onto a target object 14, and is reflected by the target object 14 and received by the infrared receiving unit 12. The controller 15 calculates the time difference or phase difference ΔΦ between the emission time and the reception time of the light, and obtains the distance between the module 10 and the target object 14, thereby generating depth information.

The structure of the infrared emitting unit 11 is shown in FIG. 1B . The unit 11 includes a vertical cavity surface laser emitter (VCSEL) 111, a light diffuser 112 and a photodiode 113 (PD) as a detector. The VCSEL 111 is used to emit a laser pulse with a certain energy. After the laser pulse is projected onto the target object 14, it is reflected to the infrared receiving unit 12. The wavelength of the laser pulse is 940 nanometers (nanometer, nm), which belongs to near-infrared light, has a certain amount of energy, and is invisible to the naked eye. According to the definition of human eye safety in the International Electrotechnical Commission standard IEC60825-2014, it is necessary to control the laser energy emitted by the VCSEL 111 to meet the requirements of safety in use.

The PD 113 is used to receive the laser energy reflected back by the emitted laser after passing through the light diffuser 112, and convert the received laser energy into photocurrent, thereby monitoring and judging whether the laser energy changes according to the magnitude of the current.

The embodiment of the present application provides a fault detection method, which can be applied to an electronic device including a ranging module, and the electronic device can be a mobile phone, a tablet computer, a laptop computer, a robot, a drone, or other device with ranging capability. The function implemented by the fault detection method can be implemented by calling a program code by a processor in the electronic device, and of course the program code can be stored in a computer storage medium. It can be seen that the electronic device at least includes a processor and a storage medium.

FIG. 2 is a schematic diagram of an implementation flow of a fault detection method according to an embodiment of the present application. As shown in FIG. 2 , the method at least includes the following steps S201 to S203:

Step S201, receiving an opening instruction, wherein the opening instruction is used to instruct to open the distance measurement module of the electronic device. For example, when the electronic device receives an instruction for instructing to open a camera application, it is determined that the opening instruction is received. For example, a touch instruction is received on the icon of the camera application, or a voice instruction is received to instruct to open the camera application.

Step S202, in response to the start-up instruction, before controlling the light wave transmitter in the ranging module to transmit working pulses at a first regular interval, controlling the light wave transmitter to transmit at least one test pulse to perform fault detection on the ranging module to obtain a detection result; wherein the working pulse is used to measure the distance between the ranging module and the target object.

In the embodiment of the present application, there is no limitation on the type of the light wave transmitter, and the light wave transmitter may be a lamp for transmitting light waves such as ultrasound, infrared, near-infrared, etc. For example, the light wave transmitter is a laser transmitter.

For example, as shown in FIG3A, after receiving the start-up instruction, the electronic device does not directly control the light wave transmitter in the distance measurement module to transmit working pulses 301 to 30M at first regular intervals, where M is an integer greater than 1; instead, the light wave transmitter is first controlled to transmit 4 test pulses 311 to 314 to perform fault detection on the distance measurement module, so that the damage of light waves (such as lasers) to human eyes and skin can be greatly reduced. This is because, after receiving the start-up instruction, if the electronic device directly controls the light wave transmitter to transmit working pulses, a safety test is started on the working pulses emitted by the light wave transmitter during this process. Since the test process takes a certain time (such as 0.5 seconds) to complete, and the width of the working pulse is usually much less than 0.5 seconds (such as the width of the working pulse is 1 to 20 nanoseconds), during this period of time when the electronic device is performing the safety test, the light wave transmitter has already emitted a large number of working pulses. If there is an abnormality in the components in the distance measurement module (for example, the driving circuit is short-circuited or the diffusion sheet falls off), the optical power of these working pulses will be greatly enhanced, which is enough to cause damage to human eyes and skin. It should be noted that the working pulse shown in FIG. 3A is a pulse signal that the electronic device controls the light wave transmitter to emit, under the premise that no obstacles occur to the components of the ranging module.

Based on this, in an embodiment of the present application, after receiving a start-up instruction, the electronic device does not directly emit a working pulse, but instead pre-emits at least one test pulse to perform fault detection on the ranging module, and then controls the working state of the ranging module based on the result of the fault detection; in this way, the risk of harming human eyes and skin health can be greatly reduced.

It should be noted that the first rule defines that the light wave transmitter needs to transmit working pulses according to a specific pulse frequency, pulse width and duty cycle, and the configuration of these parameters is in compliance with the human eye safety specification. For example, as shown in FIG3B , the light wave transmitter is controlled to transmit working pulses intermittently with a pulse frequency of 100 megahertz (MHZ), a duty cycle (DC) of 33%, a phase time of 350 microseconds (microsecond, us), and a frame length of 33.3 milliseconds (millisecond, ms); wherein, according to the pulse frequency and duty cycle, the pulse width of the working pulse can be determined to be 33 nanoseconds (nanosecond, ns).

Step S203: controlling the working state of the ranging module according to the detection result.

Here, different detection results correspond to different working states of the ranging module. For example, through step S505, step S507 or step S509 of the following embodiment, the working state of the ranging module is controlled. That is, when the detection result is that the components in the ranging module are not faulty, the ranging module is controlled to input the working current of the light wave transmitter into the driving circuit, so that the driving circuit drives the light wave transmitter to emit the working pulse at the first regular interval; when the detection result is that the diffuser has fallen off, the ranging module is turned off to prohibit the light wave transmitter from emitting the working pulse; when the detection result is that the driving circuit is short-circuited, the ranging module is turned off, or the ranging module is controlled to input other currents less than the working current into the driving circuit, so that the driving circuit drives the light wave transmitter to emit the working pulse at the second regular interval.

The present application further provides a fault detection method, which at least includes the following steps S301 to S303:

Step S301, receiving an on instruction, wherein the on instruction is used to instruct to turn on a distance measurement module of an electronic device.

Step S302, in response to the start-up instruction, before controlling the light wave transmitter in the ranging module to transmit working pulses at first regular intervals, a plurality of instantaneous currents are sequentially input into the driving circuit in the ranging module, so that the driving circuit drives the light wave transmitter to sequentially transmit the plurality of test pulses to perform fault detection on the ranging module and obtain the detection result; wherein the working pulse is used to measure the distance between the ranging module and the target object.

The electronic device can implement step S302 through steps S402 to S404 in the following embodiments, that is, input a plurality of instantaneous currents into the driving circuit in sequence, and then determine the detection result based on the relationship between each photocurrent detected and a preset threshold range; the electronic device can also implement step S302 through steps S602 to S608 in the following embodiments, that is, after inputting an instantaneous current into the driving circuit to drive the light wave transmitter to emit a test pulse, first detect whether the photocurrent generated by the photoelectric conversion element under the reflection of the test pulse is within the corresponding threshold range, and if so, continue to input the next instantaneous current into the driving circuit; otherwise, prohibit the light wave transmitter from emitting a test pulse or a working pulse, or input a smaller working current so that the light wave transmitter emits a working pulse with smaller energy.

It should be noted that there is no limitation on the number and size of multiple instantaneous currents. Generally speaking, at least two instantaneous currents are input into the driving circuit in sequence, which can improve the accuracy of the detection results and reduce the probability of misjudgment. In implementation, the sizes of multiple instantaneous currents can be the same or different. However, each instantaneous current must be less than or equal to the maximum operating current of the light wave transmitter to comply with the human eye safety specification and avoid damage to the human eye and skin caused by excessive instantaneous current.

Step S303: Control the working state of the ranging module according to the detection result.

In an embodiment of the present application, in response to a start-up instruction, before controlling the light wave transmitter in the ranging module to transmit working pulses at a first regular interval, a plurality of instantaneous currents are sequentially input into the driving circuit, so that the driving circuit drives the light wave transmitter to sequentially transmit a plurality of test pulses to perform fault detection on the ranging module; in this way, compared with the method of directly inputting a constant current into the driving circuit to drive the light wave transmitter to transmit working pulses, the former can obtain the following technical effects based on the working pulse safety detection method: first, it can reduce damage to human eyes and skin; second, it can save power consumption; third, it can reduce the risk of components being burned out due to abnormalities in components of the ranging module, because when it is not determined whether the components of the ranging module are abnormal, the constant current (i.e., the working current) is directly passed, and there is a risk of burning out the components.

The present application further provides a fault detection method. FIG4 is a schematic diagram of an implementation flow of another fault detection method of the present application. As shown in FIG4 , the method at least includes the following steps S401 to S405:

Step S401: receiving an on instruction, wherein the on instruction is used to instruct to turn on a distance measurement module of an electronic device.

Step S402, in response to the start-up instruction, before controlling the light wave transmitter in the ranging module to transmit working pulses at a first regular interval, a plurality of instantaneous currents are sequentially input into the driving circuit in the ranging module, so that the driving circuit drives the light wave transmitter to transmit the plurality of test pulses sequentially.

Step S403, detecting the photocurrent generated by the photoelectric conversion element in the distance measurement module when each of the test pulses is emitted.

Step S404: determining the detection result according to the relationship between each photocurrent and the corresponding threshold range, so as to implement fault detection on the ranging module.

It can be understood that when the magnitude of the instantaneous current is different, the energy of the test pulse driven by the light wave transmitter is also different, so the photon density reflected by the diffuser to the photoelectric conversion element is also different, and the photocurrent generated by the photoelectric conversion element is also different. Therefore, different instantaneous currents correspond to different threshold ranges, that is, each photocurrent corresponds to a threshold range; of course, different instantaneous currents can also correspond to the same threshold range. For example, when there is no fault in the components of the ranging module, the photocurrent corresponding to the minimum operating current of the light wave transmitter is the lower limit of the threshold range, and the photocurrent corresponding to the maximum operating current is the upper limit of the threshold range. In implementation, the lower limit value can also be set to a current value close to 0.

The electronic device may determine different detection results through steps S504, S506, and S508 of the following embodiments.

Step S405: controlling the working state of the ranging module according to the detection result.

In an embodiment of the present application, a plurality of instantaneous currents are sequentially input into a driving circuit in the ranging module, so that the driving circuit drives the light wave transmitter to sequentially transmit the plurality of test pulses; the photocurrent generated by the photoelectric conversion element in the ranging module when each of the test pulses is transmitted is detected; and the detection result is determined based on the relationship between each of the photocurrents and the corresponding threshold range, so that the electronic device can more quickly perform fault detection on the ranging module.

The present application further provides a fault detection method. FIG5 is a schematic diagram of an implementation flow of another fault detection method of the present application. As shown in FIG5 , the method at least includes the following steps S501 to S509:

Step S501: receiving an on instruction, wherein the on instruction is used to instruct to turn on a distance measurement module of an electronic device.

Step S502, in response to the start-up instruction, before controlling the light wave transmitter in the ranging module to transmit working pulses at a first regular interval, a plurality of instantaneous currents are sequentially input into the driving circuit in the ranging module, so that the driving circuit drives the light wave transmitter to transmit the plurality of test pulses sequentially.

Step S503 , detecting the photocurrent generated by the photoelectric conversion element in the distance measurement module when each of the test pulses is emitted.

Step S504: when each of the photocurrents falls within the corresponding threshold range, it is determined that the detection result is that no failure has occurred in the components of the ranging module, and the process proceeds to step S505.

For example, when an instantaneous current of 2A is input into the driving circuit and there is no fault in the components in the ranging module, the corresponding photocurrent value is 30 microamps (uA). During implementation, the corresponding threshold range can be set to [1uA, 50uA].

Step S505 , controlling the distance measurement module to input the working current of the light wave transmitter into the driving circuit, so that the driving circuit drives the light wave transmitter to transmit the working pulse at the first regular interval.

For example, the operating current of the light wave transmitter is 1 ampere (Ampere, A) to 3A. During implementation, an operating current of 2A is input to the driving circuit.

In other embodiments, during the process of the light wave transmitter emitting working pulses at first regular intervals, the electronic device may also detect the photocurrent generated by the photoelectric conversion element when emitting each working pulse. If at least one photocurrent is greater than a preset threshold, or less than a preset threshold, the current working current may be adjusted according to the difference between the photocurrent and the preset threshold so that the optical power of the working pulse emitted by the light wave transmitter is maintained within a specific range, so as to solve the problem of inconsistent light intensity emitted by multiple electronic devices.

Step S506: When at least one of the photocurrents is greater than the upper limit of the corresponding threshold range, it is determined that the detection result is that the drive circuit is short-circuited, and the process proceeds to step S507.

It can be understood that if a short circuit occurs in the driving circuit, even if a smaller current is input into the driving circuit, it will cause the driving circuit to output a larger current, thereby triggering the light wave transmitter to emit a very high-energy light wave, thereby increasing the photon density on the photoelectric conversion element and generating a larger photocurrent.

Step S507, turning off the distance measurement module to prohibit the light wave transmitter from emitting the working pulse, thereby preventing the light wave transmitter from emitting a large amount of strong light and damaging human eyes and skin health.

In other embodiments, when the electronic device detects that the driving circuit is short-circuited, it can also control the ranging module to input other currents less than the working current into the driving circuit, so that the driving circuit drives the light wave transmitter to transmit working pulses at intervals according to the second rule. It should be noted here that the second rule can be the same as the first rule or different; when different, the parameters such as pulse frequency, pulse width or duty cycle in the second rule are smaller, so that the light wave transmitter can emit working pulses with lower power.

In other embodiments, when the electronic device detects that the driving circuit is short-circuited, it can also output a prompt message to prompt the user to increase the distance between the ranging module and the target object. For example, when the user opens the camera to take a selfie, a prompt message pops up on the image preview interface to prompt the user to move the camera further away from himself.

Step S508 , when each of the photocurrents is less than the lower limit of the corresponding threshold range, it is determined that the detection result is that the diffusion sheet in the ranging module has fallen off, and the process proceeds to step S509 .

Understandably, if the diffuser falls off, two problems will occur: first, the power density of the emitted pulse signal increases, which can cause damage to human eyes and skin; second, no photons are reflected to the photoelectric conversion element, which will cause the photocurrent generated by the photoelectric conversion element to be very small, almost close to 0. Therefore, when the electronic device is implemented, in order to avoid interference of other optical signals on the detection results, the lower limit value is generally set to a non-zero value, for example, the lower limit value is set to 1uA.

Step S509, turning off the distance measurement module to prohibit the light wave transmitter from emitting the working pulse, thereby reducing the risk of harming human eyes and skin health.

In the embodiment of the present application, a specific detection result is determined based on the relationship between each of the photocurrents and the corresponding threshold range, thereby providing a basis for better controlling the working state of the ranging module in the subsequent process.

The present application further provides a fault detection method. FIG6 is a schematic diagram of an implementation flow of another fault detection method of the present application. As shown in FIG6 , the method at least includes the following steps S601 to S610:

Step S601: receiving an on instruction, wherein the on instruction is used to instruct to turn on a distance measurement module of an electronic device.

Step S602, in response to the start-up instruction, before controlling the light wave transmitter in the ranging module to transmit working pulses at a first regular interval, N instantaneous currents are sequentially input into the driving circuit in the ranging module, so that the driving circuit drives the light wave transmitter to transmit the N test pulses sequentially, where N is an integer greater than 1.

When the electronic device implements step S602, N instantaneous currents can be input into the driving circuit in order from small to large. For example, the minimum operating current Ia of the light wave transmitter is input into the driving circuit as the first instantaneous current, and then after a certain interval, the typical operating current Ityp of the light wave transmitter is input into the driving circuit as the second instantaneous current. In this way, by inputting the two instantaneous currents into the driving circuit in sequence, on the one hand, false detection can be avoided, so that the obtained detection result is more accurate; on the other hand, the second instantaneous current uses the maximum operating current of the light wave transmitter, which can improve the detection sensitivity. In other examples, the first instantaneous current is less than the second instantaneous current, and the second instantaneous current can be less than the maximum operating current of the light wave transmitter.

There is no limitation on the value of N here, that is, in implementation, 2 or 3 or even more instantaneous currents may be input into the driving circuit in sequence.

Step S603, determine whether the characteristics of the transmitted Nth test pulse meet the conditions; if not, execute step S604; if so, execute step S605.

The electronic device can determine whether the characteristics of the Nth test pulse emitted meet the conditions through steps S703, S704, S706 and S708 in the following embodiments. That is, the photocurrent generated by the photoelectric conversion element in the distance measurement module when the Nth test pulse is emitted is detected; when the photocurrent belongs to the corresponding threshold range, it is determined that the characteristics of the Nth test pulse meet the conditions; conversely, when the photocurrent is not within the corresponding threshold range, it is determined that the characteristics of the Nth test pulse do not meet the conditions; when the conditions are not met, it indicates that a certain component of the distance measurement module may be abnormal (for example, the driving circuit is short-circuited, the diffusion sheet falls off, etc.), and step S604 is executed at this time to prohibit the next instantaneous current from being input into the driving circuit, thereby reducing the damage caused to human eyes and skin during the fault detection process.

Step S604, prohibiting the next instantaneous current from being input into the driving circuit to end the fault detection of the ranging module and obtain the detection result, and then executing step S609 or step S610 according to the detection result.

The electronic device may determine the detection result according to the relationship between the photocurrent generated by the photoelectric conversion element when the Nth test pulse is emitted and the corresponding threshold range, for example, by determining the detection result through step S704 or step S706 of the following embodiment.

Step S605 , continue to input the next instantaneous current into the driving circuit, so that the driving circuit drives the light wave transmitter to emit the next test pulse.

When the electronic device implements step S605, it can continue to input the typical working current of the light wave transmitter into the driving circuit; in this way, first, the reliability of the detection result can be increased; second, the detection result is more valuable for reference, because when the working pulse is subsequently emitted, the working current input to the driving circuit is the typical working current. For example, a typical working current of 2A is input into the driving circuit.

Step S606, determining whether the photocurrent generated by the photoelectric conversion element when emitting the next test pulse meets the condition; if so, executing step S607; if not, executing step S608.

Step S607, controlling the distance measurement module to input the working current of the light wave transmitter into the driving circuit, so that the driving circuit drives the light wave transmitter to transmit the working pulse at the first regular interval.

In other embodiments, if it is determined in step S606 that the photocurrent generated by the photoelectric conversion element also meets the conditions when emitting the next test pulse, an instantaneous current continues to be input into the driving circuit, so that the driving circuit drives the light wave transmitter to emit another test pulse, thereby completing the fault detection, which can increase the reliability of the detection results.

Step S608, ending the fault detection of the ranging module and obtaining the detection result, and then executing step S609 or step S610 according to the detection result.

Step S609, when the detection result is that the diffusion sheet has fallen off, shut down the distance measurement module to prohibit the light wave transmitter from emitting the working pulse.

Step S610, when the detection result is that the driving circuit is short-circuited, turn off the ranging module, or control the ranging module to input other currents less than the working current into the driving circuit, so that the driving circuit drives the light wave transmitter to emit working pulses at a second regular interval.

The present application further provides a fault detection method, which at least includes the following steps S701 to S703:

Step S701: receiving an on instruction, wherein the on instruction is used to instruct to turn on a distance measurement module of an electronic device.

Step S702, in response to the start instruction, before controlling the light wave transmitter in the distance measurement module to transmit working pulses at first regular intervals, sequentially inputting N instantaneous currents into the driving circuit in the distance measurement module, so that the driving circuit drives the light wave transmitter to sequentially transmit the N test pulses, where N is an integer greater than 1;

Step S703, detecting the photocurrent generated by the photoelectric conversion element in the ranging module when the Nth test pulse is emitted;

Step S704, at least when the photocurrent is greater than the upper limit value of the corresponding threshold range, it is determined that the characteristics of the Nth test pulse do not meet the conditions, and it is prohibited to continue to input the next instantaneous current into the drive circuit to end the fault detection of the ranging module, and determine that the detection result is that the drive circuit is short-circuited, and enter step S705.

For example, if the photocurrent generated by the photoelectric conversion element when emitting the Nth test pulse is greater than the upper limit of the corresponding threshold range, it is determined that the characteristic of the Nth test pulse does not meet the condition, and it is prohibited to continue to input the next instantaneous current into the drive circuit to end the fault detection of the ranging module, and determine that the detection result is that the drive circuit is short-circuited. For another example, if the photocurrent generated by the photoelectric conversion element when each of the N test pulses is emitted is greater than the upper limit of the corresponding threshold range, the result in step S704 is obtained.

Step S705, turning off the distance measurement module, or controlling the distance measurement module to input other currents smaller than the working current into the driving circuit, so that the driving circuit drives the light wave transmitter to emit working pulses at second regular intervals.

Step S706, at least when the photocurrent is less than the lower limit of the corresponding threshold range, determine that the characteristics of the Nth test pulse do not meet the conditions, and determine that the detection result is that the diffusion sheet in the ranging module has fallen off, and enter step S707.

Step S707, turning off the distance measurement module to prohibit the light wave transmitter from emitting the working pulse.

Step S708, at least when the photocurrent belongs to the corresponding threshold range, continue to input the next instantaneous current into the driving circuit, so that the driving circuit drives the light wave transmitter to emit the next test pulse;

Step S709, determining whether the photocurrent generated by the photoelectric conversion element when emitting the next test pulse meets a condition; if so, executing step S710; if not, executing step S711;

Step S710, controlling the distance measurement module to input the working current of the light wave transmitter into the driving circuit, so that the driving circuit drives the light wave transmitter to transmit the working pulse at the first regular interval.

Step S711, end the fault detection of the ranging module and obtain the detection result, and then execute step S705 or step S707 according to the detection result.

With the development of technologies and markets such as body-sensing interaction and control, 3D object recognition and perception, intelligent environment perception, and dynamic map construction, major application scenarios are now beginning to have an increasing interest in and demand for 3D vision and recognition technologies.

In terms of technology, compared with the other two solutions for 3D depth vision, the advantages of TOF distance measurement in practical applications are self-evident. For example, when calculating the depth of field after the picture is taken, no post-processing is required, which can avoid time delays and save the related costs of using a powerful post-processing system; moreover, TOF distance measurement has a large scale flexibility, and in most cases, the adjustment of the distance measurement scale can be completed by simply changing the light source intensity, optical field of view, and the pulse frequency of the laser transmitter; in addition, because the TOF distance measurement module has multiple advantages such as being not easily affected by external light interference, small size, fast response speed, and high recognition accuracy, the TOF distance measurement module is becoming the preferred technical solution for 3D vision in both mobile and automotive applications.

When the TOF ranging module is used on mobile devices such as mobile phones, it can be used to measure distance and size, make three-dimensional modeling of objects in the scene, blur the camera, play somatosensory games, and cooperate with augmented reality (AR) glasses for corresponding applications.

In the TOF ranging module, the factors that affect the laser energy emitted by the infrared transmitting unit mainly include: power supply current, pulse frequency (Frequency), pulse width and duty cycle; among which:

Pulse frequency: The laser transmitter (i.e., an example of the light wave transmitter) emits a modulated pulse signal. The modulation speed of the signal is the frequency, which is usually between 20 MHZ and 100 MHZ.

Pulse width: The reciprocal of the pulse frequency is called the period, and the period * duty cycle is the pulse width, usually 1-20ns;

Duty cycle: Pulse width/period, usually between 10% and 50%;

Pulse frequency, pulse width and duty cycle are configuration parameters of the TOF sensor and VCSEL drive circuit, which are usually fixed after setting.

The power supply current of the driving circuit is a direct factor affecting the laser energy. Usually, the TOF ranging module has an overcurrent protection mechanism. The specific principle is: the photodiode PD of the infrared emitting unit converts the reflected laser energy into a corresponding photocurrent, and judges whether the laser energy emitted by the laser transmitter has changed based on the size of the photocurrent. For example, the current threshold of the PD is set in advance according to the maximum driving current of the laser transmitter. If the photocurrent of the PD exceeds the current threshold during operation, the protection mechanism will be triggered to shut down the laser transmitter.

The TOF safety detection and protection mechanisms in related technologies are all performed after the laser emitter starts working. If an abnormal situation occurs, such as a short circuit in the driving circuit of the laser emitter, the laser emitter will be at a higher current level when it is just powered on, causing the energy of the initial emitted laser to increase. At this time, using the laser will pose a risk to human eye safety.

The relevant laser energy monitoring scheme is carried out after the laser transmitter starts working, and the laser energy emitted initially cannot be monitored. In this case, if the TOF ranging module is used without discovering the abnormality of the laser transmitter's driving circuit, there will be certain risks to human eye safety.

Based on this, an exemplary application of an embodiment of the present application in a practical application scenario will be described below.

In the embodiment of the present application, based on the relevant laser energy monitoring, the laser emitter is driven by different currents to pre-emit several pulse signals (i.e., the test pulses), and the photocurrent of the PD is used to determine whether the driving circuit is normal, so as to realize the monitoring of the initially emitted laser energy.

The specific implementation method is as follows. Taking the 100MHZ TOF ranging module as an example, the implementation method is:

1) According to the safety standards, for the 100MHZ TOF ranging module, calculate the maximum laser current that is acceptable to human eye safety, denoted as Ia;

2) According to the operating current range of the laser transmitter, set the current threshold range of the corresponding PD; for example, the operating current range of the laser transmitter is [Imin, Imax], and the typical value is Ityp; the current value range corresponding to the PD is [imin, imax];

3) 4 drive currents (i.e. instantaneous currents) are set, which are the first current (Imin), the second current (Ia), the third current (Ityp), and the fourth current (Ityp), respectively. As shown in FIG7 , a first pulse signal, a second pulse signal, a third pulse signal, and a fourth pulse signal are generated, respectively. The third pulse signal and the fourth pulse signal are the same, and the purpose is to verify the stability of the third current. Part of the energy of the 4 pulse signals is reflected to the PD through the diffuser, and the PD corresponds to 4 current values.

4) Before starting the phase operation, four low-frequency pulse signals are respectively emitted according to the four-level current drive;

5) If the four drive currents are within the corresponding current thresholds of the PD, it is determined that the drive current of the laser transmitter is normal, and the phase operation is turned on, as shown in FIG7 , and the phase pulse signal (ie, the working pulse) starts to be emitted;

6) As shown in FIG8 , if the PD current value corresponding to the second pulse signal exceeds the upper limit of the current threshold range, it is determined that the current is too large and the phase operation is stopped;

As shown in FIG. 9 , when the electronic device executes the above method, the following steps S901 to S906 may be included:

Step S901, turn on the TOF ranging module, and then go to step S902;

Step S902, driving the laser transmitter to emit four low-frequency pulse signals according to four preset drive current levels;

Step S903, reading out the PD current value corresponding to the pulse signal under the 4-level driving current;

Step S904, determining whether each PD current value is within the corresponding threshold range; if yes, executing step S905; otherwise, executing step S906;

Step S905, driving the laser emitter with the working current of the laser emitter according to the pre-configured parameters to intermittently emit working pulses (i.e., start phase operation);

Step S906: If the PD current value corresponding to the second pulse signal exceeds the upper limit of the current threshold range, it is determined that the current is too large, and the phase operation is stopped.

In the embodiments of the present application, on the one hand, the initial laser energy is monitored, which is conducive to early detection of drive circuit abnormalities and timely triggering of protection mechanisms to shut down the laser emitter; on the other hand, the laser emission energy can be effectively controlled during operation.

In the embodiment of the present application, several pulse signals are pre-emitted by different current driving, and whether the current driving is normal is judged by the current of the PD, so as to realize the monitoring of the laser energy emitted initially.

In other embodiments, four current drives can also be set in sequence as the first current (I0), the second current (I1), the third current (I2) and the fourth current (I3). These four currents increase in sequence, as shown in FIG10, to generate a first pulse signal, a second pulse signal, a third pulse signal and a fourth pulse signal respectively; the amplitudes corresponding to the first pulse signal to the fourth pulse signal are all smaller than the amplitude corresponding to the maximum current.

If the four drive currents are within the corresponding current threshold of the PD, it is determined that the laser drive current is normal, and at this time, as shown in FIG. 10 , the phase operation is turned on; otherwise, the phase operation is not turned on.

In other embodiments, this scheme can also be used to detect in advance whether the diffuser has fallen off; specifically, before using the laser transmitter, the state of the diffuser is unknown. 1) If the diffuser is in a state of falling off at this time, the laser transmitter emits laser according to normal settings. During the period of time when the diffuser is detected and judged to have fallen off, the emitted laser will cause damage to human eyes and skin; 2) If the diffuser has not fallen off at this time, but the driving circuit of the laser transmitter is abnormal, causing the current to increase, the laser transmitter emits laser according to normal settings, and the light pulse power will also increase, and the emitted laser will cause damage to human eyes and skin.

Therefore, the state of the diffuser can be determined by emitting three low-frequency pulse signals, and then whether to start the phase operation can be determined. As shown in Figure 11, after the TOF ranging module is turned on, three low-frequency pulse signals are emitted to determine whether the PD current value is less than the first threshold; if the PD current values of the three times are all less than the first threshold, it is determined that the diffuser is off and the phase operation is not turned on; if the PD current values of the three times are greater than the first threshold and less than the second threshold, it is determined that the diffuser is normal, the laser current is also normal, and the phase operation is turned on.

Based on the foregoing embodiments, an embodiment of the present application provides a fault detection device, which includes the modules included and the units included in the modules, and can be implemented by a processor in an electronic device; of course, it can also be implemented by a specific logic circuit; in the implementation process, the processor can be a central processing unit (CPU), a microprocessor (MPU), a digital signal processor (DSP) or a field programmable gate array (FPGA), etc.

FIG12 is a schematic diagram of the structure of a fault detection device according to an embodiment of the present application. As shown in FIG12 , the device 120 includes a receiving module 121 and a control module 122, wherein:

The receiving module 121 is configured to receive an opening instruction, wherein the opening instruction is used to instruct to open the distance measurement module of the device 120;

The control module 122 is configured to, in response to the start instruction, control the light wave transmitter in the distance measurement module to transmit at least one test pulse before controlling the light wave transmitter in the distance measurement module to transmit working pulses at first regular intervals, so as to perform fault detection on the distance measurement module and obtain a detection result; wherein the working pulse is used to measure the distance between the distance measurement module and the target object;

The control module 122 is further configured to control the working state of the ranging module according to the detection result.

In other embodiments, the control module 122 is configured to respond to the start-up instruction and, before controlling the light wave transmitter in the ranging module to transmit working pulses at first regular intervals, sequentially input a plurality of instantaneous currents into the driving circuit in the ranging module, so that the driving circuit drives the light wave transmitter to transmit the plurality of test pulses sequentially to perform fault detection on the ranging module and obtain the detection result.

In other embodiments, the control module 122 includes: a first driving unit, configured to input multiple instantaneous currents into the driving circuit in the ranging module in sequence, so that the driving circuit drives the light wave transmitter to sequentially emit the multiple test pulses; a first detection unit, configured to detect the photocurrent generated by the photoelectric conversion element in the ranging module when each of the test pulses is emitted; and a first determination unit, configured to determine the detection result based on the relationship between each of the photocurrents and the corresponding threshold range, so as to realize fault detection of the ranging module.

In other embodiments, the first determination unit is configured to: when each of the photocurrents belongs to the corresponding threshold range, determine that the detection result is that there is no failure in the components of the ranging module; when at least one of the photocurrents is greater than the upper limit value of the corresponding threshold range, determine that the detection result is that the driving circuit is short-circuited; when each of the photocurrents is less than the lower limit value of the corresponding threshold range, determine that the detection result is that the diffusion sheet in the ranging module has fallen off.

In other embodiments, the control module 122 includes: a second driving unit, configured to input N instantaneous currents into the driving circuit in the ranging module in sequence, so that the driving circuit drives the optical wave transmitter to transmit the N test pulses in sequence, where N is an integer greater than 1; a second determining unit, configured to prohibit the next instantaneous current from being input into the driving circuit when the characteristics of the transmitted Nth test pulse do not meet the conditions, so as to end the fault detection of the ranging module and obtain the detection result.

In other embodiments, the second determination unit is configured to: detect the photocurrent generated by the photoelectric conversion element in the ranging module when the Nth test pulse is emitted; at least when the photocurrent is greater than the upper limit value of the corresponding threshold range, determine that the characteristics of the Nth test pulse do not meet the conditions, and determine that the detection result is that the driving circuit is short-circuited; at least when the photocurrent is less than the lower limit value of the corresponding threshold range, determine that the characteristics of the Nth test pulse do not meet the conditions, and determine that the detection result is that the diffusion sheet in the ranging module has fallen off.

In other embodiments, the control module 122 is configured to: when the detection result is that there is no failure in the components of the ranging module, control the ranging module to input the working current of the light wave transmitter into the driving circuit, so that the driving circuit drives the light wave transmitter to emit the working pulse at the first regular interval; when the detection result is that the diffuser has fallen off, turn off the ranging module to prohibit the light wave transmitter from emitting the working pulse; when the detection result is that the driving circuit is short-circuited, turn off the ranging module, or control the ranging module to input other currents less than the working current into the driving circuit, so that the driving circuit drives the light wave transmitter to emit working pulses at second regular intervals.

The description of the above device embodiment is similar to the description of the above method embodiment, and has similar beneficial effects as the method embodiment. For technical details not disclosed in the device embodiment of the present application, please refer to the description of the method embodiment of the present application for understanding.

It should be noted that in the embodiment of the present application, if the above-mentioned fault detection method is implemented in the form of a software function module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the embodiment of the present application is essentially or the part that contributes to the relevant technology can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including several instructions to enable an electronic device (which can be a mobile phone, a tablet computer, a laptop computer, a robot, a drone, etc.) to execute all or part of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a U disk, a mobile hard disk, a read-only memory (ROM), a disk or an optical disk. In this way, the embodiment of the present application is not limited to any specific combination of hardware and software.

Correspondingly, an embodiment of the present application provides an electronic device, and Figure 13 is a schematic diagram of a hardware entity of the electronic device of the embodiment of the present application. As shown in Figure 13, the hardware entity of the electronic device 130 includes: a memory 131 and a processor 132, the memory 131 stores a computer program that can be run on the processor 132, and the processor 132 implements the steps in the fault detection method provided in the above embodiment when executing the program.

The memory 131 is configured to store instructions and applications executable by the processor 132, and can also cache data to be processed or processed by the processor 132 and various modules in the electronic device 130 (for example, image data, audio data, voice communication data, and video communication data), which can be implemented through flash memory (FLASH) or random access memory (Random Access Memory, RAM).

Correspondingly, an embodiment of the present application provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps in the fault detection method provided in the above embodiment are implemented.

It should be noted here that the description of the above storage medium and device embodiments is similar to the description of the above method embodiments, and has similar beneficial effects as the method embodiments. For technical details not disclosed in the storage medium and device embodiments of this application, please refer to the description of the method embodiments of this application for understanding.

It should be understood that "one embodiment" or "an embodiment" mentioned throughout the specification means that specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in various embodiments of the present application, the size of the sequence number of the above-mentioned processes does not mean the order of execution, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application. The above-mentioned sequence numbers of the embodiments of the present application are only for description and do not represent the advantages and disadvantages of the embodiments.

It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as: multiple units or components can be combined, or can be integrated into another system, or some features can be ignored, or not executed. In addition, the coupling, direct coupling, or communication connection between the components shown or discussed can be through some interfaces, and the indirect coupling or communication connection of the devices or units can be electrical, mechanical or other forms.

The units described above as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units; they may be located in one place or distributed on multiple network units; some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

In addition, all functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may be a separate unit, or two or more units may be integrated into one unit; the above-mentioned integrated units may be implemented in the form of hardware or in the form of hardware plus software functional units.

A person of ordinary skill in the art can understand that: all or part of the steps of implementing the above-mentioned method embodiment can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above-mentioned method embodiment; and the aforementioned storage medium includes: various media that can store program codes, such as mobile storage devices, read-only memories (ROM), magnetic disks or optical disks.

Alternatively, if the above-mentioned integrated unit of the present application is implemented in the form of a software function module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application can essentially or in other words, the part that contributes to the relevant technology can be embodied in the form of a software product, which is stored in a storage medium, including several instructions for an electronic device (which can be a mobile phone, tablet computer, laptop computer, robot, drone, etc.) to execute all or part of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as mobile storage devices, ROM, magnetic disks or optical disks.

The methods disclosed in several method embodiments provided in this application can be arbitrarily combined without conflict to obtain new method embodiments.

The features disclosed in several product embodiments provided in this application can be arbitrarily combined without conflict to obtain new product embodiments.

The features disclosed in several method or device embodiments provided in this application can be arbitrarily combined without conflict to obtain new method embodiments or device embodiments.

The above is only an implementation method of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims (9)

1. A fault detection method, characterized in that the method comprises: receiving an opening instruction, wherein the opening instruction is used to instruct to open a distance measurement module of an electronic device; In response to the start-up instruction, before controlling the light wave transmitter in the distance measurement module to transmit working pulses at first regular intervals, controlling the light wave transmitter to transmit at least one test pulse to perform fault detection on the distance measurement module to obtain a detection result; wherein the working pulse is used to measure the distance between the distance measurement module and the target object; According to the detection result, controlling the working state of the ranging module; Wherein, controlling the working state of the ranging module according to the detection result includes: when the detection result shows that there is no failure in the components of the ranging module, controlling the ranging module to input the working current of the light wave transmitter into the driving circuit, so that the driving circuit drives the light wave transmitter to transmit the working pulse at the first regular interval; If the detection result shows that the diffusion sheet has fallen off, shutting down the distance measurement module to prohibit the light wave transmitter from emitting the working pulse; or When the detection result shows that the driving circuit is short-circuited, the ranging module is turned off, or the ranging module is controlled to input other currents less than the working current into the driving circuit, so that the driving circuit drives the light wave transmitter to emit working pulses at a second regular interval. 2. The method according to claim 1, characterized in that the step of controlling the optical wave transmitter to transmit at least one test pulse to perform fault detection on the ranging module and obtain a detection result comprises: Multiple instantaneous currents are sequentially input into the driving circuit in the ranging module, so that the driving circuit drives the light wave transmitter to sequentially transmit multiple test pulses to perform fault detection on the ranging module and obtain the detection result. 3. The method according to claim 2, characterized in that the step of sequentially inputting a plurality of instantaneous currents into a driving circuit in the ranging module so that the driving circuit drives the optical wave transmitter to sequentially transmit a plurality of the test pulses to perform fault detection on the ranging module and obtain a detection result comprises: Inputting a plurality of instantaneous currents sequentially into a driving circuit in the distance measurement module, so that the driving circuit drives the light wave transmitter to sequentially transmit the plurality of test pulses; Detecting the photocurrent generated by the photoelectric conversion element in the ranging module when each of the test pulses is emitted; The detection result is determined according to the relationship between each photocurrent and the corresponding threshold range to implement fault detection of the ranging module. 4. The method according to claim 3, characterized in that the determining the detection result according to the relationship between each photocurrent and the corresponding threshold range comprises: In the case where each of the photocurrents falls within the corresponding threshold range, determining that the detection result is that no failure has occurred in a component in the ranging module; In the case where at least one of the photocurrents is greater than an upper limit value of a corresponding threshold range, determining that the detection result is that the drive circuit is short-circuited; In the case where each of the photocurrents is less than the lower limit of the corresponding threshold range, it is determined that the detection result is that the diffusion sheet in the ranging module has fallen off. 5. The method according to claim 2, characterized in that the step of sequentially inputting a plurality of instantaneous currents into a driving circuit in the ranging module so that the driving circuit drives the optical wave transmitter to sequentially transmit the plurality of test pulses to perform fault detection on the ranging module and obtain the detection result comprises: Inputting N instantaneous currents sequentially into the driving circuit in the ranging module, so that the driving circuit drives the light wave transmitter to sequentially transmit N test pulses, where N is an integer greater than 1; When the characteristics of the Nth test pulse transmitted do not meet the conditions, it is prohibited to continue to input the next instantaneous current into the driving circuit to end the fault detection of the ranging module and obtain the detection result. 6. The method according to claim 5, characterized in that, when the characteristic of the transmitted Nth test pulse does not meet the condition, obtaining the detection result comprises: detecting a photocurrent generated by a photoelectric conversion element in the ranging module when the Nth test pulse is emitted; At least when the photocurrent is greater than an upper limit value of the corresponding threshold range, it is determined that the characteristic of the Nth test pulse does not meet the condition, and the detection result is determined to be that the drive circuit is short-circuited. 7. The method according to claim 6, characterized in that the method further comprises: At least when the photocurrent is less than the lower limit of the corresponding threshold range, it is determined that the characteristic of the Nth test pulse does not meet the condition, and the detection result is determined to be that the diffusion sheet in the ranging module has fallen off. 8. A fault detection device, characterized in that the device comprises: A receiving module, configured to receive an opening instruction, wherein the opening instruction is used to instruct to open the distance measurement module of the device; The control module is configured to, in response to the start instruction, control the light wave transmitter in the distance measurement module to transmit at least one test pulse before controlling the light wave transmitter in the distance measurement module to transmit working pulses at first regular intervals, so as to perform fault detection on the distance measurement module and obtain a detection result; wherein the working pulse is used to measure the distance between the distance measurement module and the target object; The control module is further configured to control the working state of the ranging module according to the detection result; wherein, controlling the working state of the ranging module according to the detection result includes: when the detection result shows that there is no failure in the components of the ranging module, controlling the ranging module to input the working current of the light wave transmitter into the driving circuit, so that the driving circuit drives the light wave transmitter to transmit the working pulse at the first regular interval; If the detection result shows that the diffusion sheet has fallen off, shutting down the distance measurement module to prohibit the light wave transmitter from emitting the working pulse; or When the detection result shows that the driving circuit is short-circuited, the ranging module is turned off, or the ranging module is controlled to input other currents less than the working current into the driving circuit, so that the driving circuit drives the light wave transmitter to emit working pulses at a second regular interval. 9. An electronic device comprising a memory and a processor, wherein the memory stores a computer program that can be run on the processor, wherein the processor implements the steps of the fault detection method according to any one of claims 1 to 7 when executing the program.