Gear detection circuit, gear detection method, gear monitoring method, and electronic device

Abstract

The present application relates to gear detection technical field, provide gear detection circuit, gear detection method, gear monitoring method and electronic equipment.The gear detection circuit includes: constant light emitting circuit, for sending light intensity constant light signal;Photoelectric conversion circuit, with constant light emitting circuit between the space for the sawtooth of gear passes, photoelectric conversion circuit includes first detection circuit comprising first photosensitive element, first detection circuit is used for output first photosensitive element sensing light signal, and the first electric signal generated by the tooth thickness profile of sawtooth is shielded;And / or second detection circuit comprising second photosensitive element array, second detection circuit is used for output second photosensitive element array sensing light signal, and the second electric signal generated by the end face projection of sawtooth is shielded.The present application detects the tooth thickness profile and end face projection of sawtooth by photoelectric sensing, judges whether the sawtooth has defects such as wear, displacement, etc., and accurately measures the health status of gear without disassembling gear.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gear detection, in particular to a gear detection circuit, a gear detection method, a gear monitoring method and an electronic device. BACKGROUND

[0002] In the use process, gears are prone to defects such as sawtooth wear and displacement, causing transmission failure. The current method for checking the gear is to disassemble the gear and then observe the sawtooth with the naked eye or measure the sawtooth with a caliper. The current method requires the gear to be disassembled, and the disassembly process not only takes a long time, but also easily causes damage to the gear. In addition, the naked eye observation method cannot objectively evaluate the gear condition, and the caliper measurement method will limit the measurement accuracy due to the accuracy of the caliper.

[0003] It should be noted that the information disclosed in the above background section is only used to strengthen the understanding of the background of the present application, and therefore can include information that does not constitute prior art known to those of ordinary skill in the art. SUMMARY

[0004] Therefore, the present application provides a gear detection circuit, a gear detection method, a gear monitoring method and an electronic device, which detect the tooth thickness profile and end face projection of the sawtooth through photoelectric induction, and determine whether the sawtooth has defects such as wear and displacement, so as to accurately measure the health condition of the gear without disassembling the gear, and provide a basis for protecting the gear transmission performance.

[0005] According to one aspect of the present application, a gear detection circuit is provided, comprising: a constant light emitting circuit comprising a light source for emitting a light signal with constant light intensity; a photoelectric conversion circuit comprising: a first detection circuit comprising at least one first photosensitive element, the first photosensitive element being located in a light range of the light source, a first space for a sawtooth to pass being formed between the first photosensitive element and the light source, the first detection circuit being configured to output a first electric signal generated by the first photosensitive element in response to the light signal and being shielded by a tooth profile of the sawtooth; wherein the first photosensitive element comprises a plurality of first photosensitive elements arranged along a tooth height direction of the sawtooth; when a corresponding sawtooth passes through the first space, the tooth profile of each tooth height position of the sawtooth respectively shields the light signal of the plurality of first photosensitive elements irradiated by the light source, and the first detection circuit outputs a first electric signal representing an inter-tooth profile distance of each tooth height position of the sawtooth; and / or a second detection circuit comprising a second photosensitive element array, the second photosensitive element array being located in the light range of the light source, a second space for the sawtooth to pass being formed between the second photosensitive element array and the light source, the second detection circuit being configured to output a second electric signal generated by the second photosensitive element array in response to the light signal and being shielded by a projection of an end face of the sawtooth; wherein when a corresponding sawtooth passes through the second space, the light source irradiates the end face of the sawtooth and projects to the second photosensitive element array, and the second detection circuit outputs a second electric signal representing an area of the end face of the sawtooth.

[0006] The constant light emitting circuit emits a light signal with constant light intensity, providing stable input for the photoelectric conversion circuit and ensuring the accuracy of the detection results of the photoelectric conversion circuit. The photoelectric conversion circuit and the constant light emitting circuit are arranged to leave a space for the sawtooth to pass, so that the gear can be detected without disassembly during detection. The first photosensitive element is located in the light range of the light source and forms a first space for the sawtooth to pass between the first photosensitive element and the light source; when no sawtooth passes through the first space, the first photosensitive element senses the light signal; when a sawtooth passes through the first space, the tooth profile of the sawtooth shields the light signal, and the first electric signal generated by the first photosensitive element changes; thus, the change of the first electric signal output by the first detection circuit can detect parameters related to the tooth profile of the sawtooth. The second photosensitive element array is located in the light range of the light source and forms a second space for the sawtooth to pass between the second photosensitive element array and the light source; when no sawtooth passes through the second space, the second photosensitive element array completely receives the light signal irradiation; when a sawtooth passes through the second space, the end face of the sawtooth is projected to the second photosensitive element array by the light signal, causing the second electric signal generated by the second photosensitive element shielded by the projection of the end face of the sawtooth to change; thus, the change of the second electric signal output by the second detection circuit can detect parameters related to the projection of the end face of the sawtooth.

[0007] The gear detection circuit detects the tooth thickness profile and the end face projection of the sawtooth through photoelectric induction, and determines whether the sawtooth has defects such as wear and displacement, so as to accurately measure the health condition of the gear without disassembling the gear, and provide a basis for ensuring the gear transmission performance.

[0008] When no sawtooth passes through the first space, the first photosensitive element receives the light signal and outputs the first electric signal with high level; when a sawtooth passes through the first space, the light signal is blocked by the tooth thickness profile of the sawtooth, and the first photosensitive element outputs the first electric signal with low level; when the tooth thickness profile leaves the first space, the first photosensitive element receives the light signal again and outputs the first electric signal with high level. In this way, according to the duration of the first electric signal with low level and the running speed of the gear, the related parameters of the tooth profile distance of the sawtooth can be obtained.

[0009] The plurality of first photosensitive elements are arranged along the tooth height direction of the sawtooth, and can detect the tooth profile distance of different tooth height positions of the sawtooth respectively; the more the number of the first photosensitive elements is, the more accurately the tooth profile shape of the sawtooth can be fed back, and the more precise the detection result is.

[0010] When no sawtooth passes through the second space, each second photosensitive element in the second photosensitive element array receives the light signal and outputs the second electric signal with high level; when a sawtooth passes through the second space, the light signal is partially blocked by the end face projection of the sawtooth, and the second photosensitive element in the second photosensitive element array which is blocked outputs the second electric signal with low level; when the end face projection leaves the second space, each second photosensitive element outputs the second electric signal with high level again. In this way, according to the second photosensitive element outputting the second electric signal with low level, the related parameters of the end face area of the sawtooth can be obtained.

[0011] In some embodiments, the light source is a parallel light source; in the case that the photoelectric conversion circuit includes the first detection circuit: the parallel light source vertically irradiates the first photosensitive element; when the corresponding sawtooth passes through the first space, the parallel light source, the sawtooth and the first photosensitive element are arranged along the tooth width direction of the sawtooth; in the case that the photoelectric conversion circuit includes the second detection circuit: the parallel light source vertically irradiates the second photosensitive element array; when the corresponding sawtooth passes through the second space, the parallel light source, the sawtooth and the second photosensitive element array are arranged along the tooth width direction of the sawtooth.

[0012] The parallel light source vertically irradiates the first photosensitive element, and when detecting the distance between tooth profiles of a sawtooth, the parallel light source, the sawtooth and the first photosensitive element are arranged along the tooth width direction of the sawtooth, so that the detection result accurately reflects the distance between tooth profiles, and whether the sawtooth has defects such as wear and displacement is determined, thereby ensuring the accuracy and reliability of the detection. The parallel light source vertically irradiates the second photosensitive element array, and when detecting the end surface area of a sawtooth, the parallel light source, the sawtooth and the second photosensitive element array are arranged along the tooth width direction of the sawtooth, so that the detection result accurately reflects the end surface area, and whether the sawtooth has defects such as wear and displacement is determined, thereby ensuring the accuracy and reliability of the detection.

[0013] In some embodiments, the constant light emitting circuit comprises a negative feedback circuit, and the light source is connected to an output terminal of the negative feedback circuit.

[0014] The negative feedback circuit can stabilize the output voltage, thereby driving the light source to emit a light signal with constant light intensity.

[0015] In some embodiments, the negative feedback circuit comprises a first operational amplifier, a same-phase input terminal of the first operational amplifier inputs a constant voltage, a first triode, a control terminal of the first triode is connected to an output terminal of the first operational amplifier, and a first output loop comprising the light source, the first triode and a sampling resistor connected in series, and a serial node of the light source and the first triode is connected to an inverse-phase input terminal of the first operational amplifier.

[0016] The first operational amplifier and the first triode constitute a main part of the negative feedback circuit, the sampling resistor feeds back the current of the first output loop in which the light source is located in real time, and the current of the first output loop is made constant through the adjustment of the first operational amplifier and the first triode, thereby driving the light source to emit a light signal with constant light intensity.

[0017] In some embodiments, the constant light emitting circuit further comprises a shaping circuit connected between a pulse signal input terminal and a same-phase input terminal of the first operational amplifier, and the shaping circuit comprises a first resistor and a second resistor connected in parallel, first ends of the first resistor and the second resistor are respectively connected to the pulse signal input terminal, and a second end of the first resistor is grounded; a first capacitor and a second capacitor connected in parallel, first ends of the first capacitor and the second capacitor are respectively connected to a second end of the second resistor and the same-phase input terminal of the first operational amplifier, and second ends of the first capacitor and the second capacitor are respectively grounded.

[0018] The shaping circuit is used to shape the pulse signal into a stable direct current voltage, which is provided to the negative feedback circuit, so that the negative feedback circuit generates a stable current to drive the light source to emit light with constant light intensity.

[0019] In some embodiments, when the photoelectric conversion circuit comprises the first detection circuit, the first detection circuit comprises at least one first sub-detection circuit respectively comprising a first photosensitive element, each of the first sub-detection circuits comprising: a second operational amplifier, the first photosensitive element being connected between two input terminals of the second operational amplifier; and a second output loop comprising a light coupling chip and a second transistor, a light emitting element of the light coupling chip being connected in series with the second transistor, a control terminal of the second transistor being connected to an output terminal of the second operational amplifier, and a photosensitive element of the light coupling chip being connected to an output terminal of the first sub-detection circuit.

[0020] The potential difference generated across the first photosensitive element is amplified by the second operational amplifier, and the change in the electrical signal generated by the first photosensitive element due to the tooth thickness profile of the saw blade when the saw blade passes through the first space is accurately collected, and the light coupling chip is driven to work, so that the second output loop outputs the first electrical signal accurately representing the distance between the tooth profiles of the saw blade.

[0021] In some embodiments, each of the first sub-detection circuits further comprises any of the following electronic elements: a second current-limiting resistor connected in series between the light emitting element of the light coupling chip and the second transistor; a third current-limiting resistor connected in series with the photosensitive element of the light coupling chip; and a pull-up resistor connected between a power supply terminal and the output terminal of the second operational amplifier.

[0022] The current-limiting resistors are used to play a current-limiting protection role in the corresponding loops. The pull-up resistor is used to stabilize the output of the second operational amplifier and avoid oscillation.

[0023] In some embodiments, when the photoelectric conversion circuit comprises the second detection circuit, the second detection circuit comprises a plurality of second sub-detection circuits respectively comprising a second photosensitive element, each of the second sub-detection circuits comprising: a third operational amplifier, the second photosensitive element being connected between two input terminals of the third operational amplifier; and a third output loop comprising a fourth current-limiting resistor and a third transistor connected in series, a control terminal of the third transistor being connected to an output terminal of the third operational amplifier, and a node connected in series between the fourth current-limiting resistor and the third transistor being connected to an output terminal of the second sub-detection circuit.

[0024] The potential difference generated across the second photosensitive element is amplified by the third operational amplifier, and the change in the electrical signal generated by the second photosensitive element due to the end face projection of the saw blade when the saw blade passes through the second space is accurately collected, and the third output loop is driven to work, so that the third output loop outputs the second electrical signal accurately representing the end face area of the saw blade.

[0025] In some embodiments, when the photoelectric conversion circuit comprises the first detection circuit, the first light-sensitive element and the light source are arranged in an enclosed space, and the first space is located in the enclosed space; when the photoelectric conversion circuit comprises the second detection circuit, the second array of light-sensitive elements and the light source are arranged in an enclosed space, and the second space is located in the enclosed space.

[0026] In this way, the transmission of the optical signal between the electronic elements is stable, and the detection of the tooth profile distance and the end face area of the sawtooth is accurate.

[0027] According to another aspect of the present application, a gear detection method is provided, which is implemented based on the gear detection circuit according to any of the above embodiments, and comprises: arranging a gear between the constant light emitting circuit and the photoelectric conversion circuit, and controlling the gear to rotate so that each sawtooth of the gear passes through the light range of the constant light emitting circuit in turn; obtaining the detection result of each sawtooth of the gear according to the electrical signal output by the photoelectric conversion circuit, which comprises: when the photoelectric conversion circuit comprises the first detection circuit, obtaining the first detection data representing the tooth profile distance of each sawtooth according to the first electrical signal output by the first detection circuit, and obtaining the first detection result of whether the corresponding sawtooth is faulty according to the first detection data; when the photoelectric conversion circuit comprises the second detection circuit, obtaining the second detection data representing the end face area of each sawtooth according to the second electrical signal output by the second detection circuit, and obtaining the second detection result of whether the corresponding sawtooth is faulty according to the second detection data.

[0028] The tooth profile distance and the end face area of the sawtooth can effectively reflect the sawtooth, especially whether the tooth surface of the sawtooth has defects such as wear and displacement affecting the transmission performance. The gear detection circuit of the present application detects the tooth thickness profile and the end face projection of the sawtooth through photoelectric sensing, thereby determining whether the sawtooth has defects such as wear and displacement, and accurately measuring the health status of the gear without disassembling the gear, thereby providing a basis for ensuring the transmission performance of the gear.

[0029] In some embodiments, when the gear is a gear rotating, the first detection data representing the tooth profile distance of each sawtooth comprises: calculating the tooth profile distance L AB , of a sawtooth at a tooth height position of the sawtooth, wherein the initial tooth profile distance at the tooth height position of the sawtooth and the center point of the gear form an isosceles triangle, L OB is the leg length of the isosceles triangle, w is the rotational speed of the gear, and t1 is the time when the first light-sensitive element at the corresponding tooth height position is blocked by the tooth thickness profile at the tooth height position.

[0030] In the initial stage of the gear being put into use, the distance between the tooth profiles at each tooth height position of the sawtooth and the center point of the gear forms an isosceles triangle, and the distance between the tooth profiles at each tooth height position is detected by the first photosensitive element arranged at the corresponding tooth height position. OB The distance between the tooth profile point B and the center point O of the gear is a known parameter of the gear; in combination with the rotational speed w of the gear and the time t1 during which the first photosensitive element at the corresponding tooth height position is shielded by the tooth thickness profile at the tooth height position, the distance L between the tooth profiles at the tooth height position of the sawtooth is obtained by using the Pythagorean theorem. AB .

[0031] In some embodiments, the first detection result of whether the corresponding sawtooth is faulty is obtained according to the first detection data, including: comparing the first detection data of each sawtooth with a first abnormal reference range and / or a first fault reference range; when the first detection data of a sawtooth falls within the first abnormal reference range, determining that the sawtooth is abnormal; when a sawtooth is determined to be abnormal for a plurality of times in succession, determining that the sawtooth is faulty; and when the first detection data of a sawtooth falls within the first fault reference range, determining that the sawtooth is faulty.

[0032] When the first detection data of a sawtooth falls within the first abnormal reference range, it indicates that the distance between the tooth profiles of the sawtooth is abnormal, and the sawtooth may be faulty; in order to avoid errors caused by single test, when a sawtooth is determined to be abnormal for a plurality of times in succession, it is determined that the sawtooth is faulty. When the first detection data of a sawtooth falls within the first fault reference range, it indicates that the distance between the tooth profiles of the sawtooth has deviated from the initial value seriously, and thus it is determined that the sawtooth is faulty.

[0033] In some embodiments, the second detection data characterizing the end face area of each sawtooth is obtained, including: when the corresponding sawtooth passes through the second space, determining the second photosensitive elements that are shielded according to the electrical signals output by the second photosensitive elements in the second photosensitive element array; and determining the end face area of the sawtooth according to the shielded second photosensitive elements.

[0034] The light source, the detected sawtooth and the second photosensitive element array can be arranged along the tooth width direction of the detected sawtooth, and the second photosensitive element array can be consistent with the initial size of the sawtooth in the tooth thickness direction, so as to facilitate the detection of the end face area of the sawtooth. When a sawtooth passes through the second space, the end face of the sawtooth is projected to the second photosensitive element array by the light signal, and the end face area of the sawtooth can be determined according to the area of the second photosensitive elements shielded by the end face of the sawtooth.

[0035] In some embodiments, the obtaining, according to the second detection data, a second detection result of whether a corresponding sawtooth is faulty comprises: comparing the second detection data of each sawtooth with a second abnormality reference range and / or a second fault reference range; when the second detection data of a sawtooth falls within the second abnormality reference range, determining that the sawtooth is abnormal; when a sawtooth is determined to be abnormal for a plurality of times in succession, determining that the sawtooth is faulty; and when the second detection data of a sawtooth falls within the second fault reference range, determining that the sawtooth is faulty.

[0036] When the second detection data of a sawtooth falls within the second abnormality reference range, it indicates that the end surface area of the sawtooth is abnormal, and the sawtooth is likely to be faulty. In order to avoid errors caused by a single test, when a sawtooth is determined to be abnormal for a plurality of times in succession, it is determined that the sawtooth is faulty. When the second detection data of a sawtooth falls within the second fault reference range, it indicates that the end surface area of the sawtooth has deviated from the initial value seriously, and thus it is determined that the sawtooth is faulty.

[0037] In some embodiments, if the first detection result indicates that two or more sawteeth are faulty when the photoelectric conversion circuit comprises the first detection circuit; and / or if the second detection result indicates that two or more sawteeth are faulty when the photoelectric conversion circuit comprises the second detection circuit; and / or if the first detection result and the second detection result indicate that the same sawtooth is faulty when the photoelectric conversion circuit comprises the first detection circuit and the second detection circuit, it is determined that the gear is faulty.

[0038] Two or more sawteeth being faulty, a plurality of parameters of the same sawtooth being seriously abnormal, and the like, can seriously affect the transmission performance of the gear, and thus it is determined that the gear is faulty.

[0039] According to still another aspect of the present application, there is provided a gear monitoring method for an electric power steering system, which is implemented based on the gear detection method according to any of the above embodiments, and comprises: issuing an alarm containing the detection result when the detection result indicates that at least one sawtooth is faulty; and controlling the electric power steering system to refuse to provide assistance when the alarm has not been eliminated at the next ignition of the vehicle.

[0040] The gear of the electric power steering system is detected based on the above gear detection method, the tooth profile and the end surface of the sawtooth during the operation of the gear are detected through photoelectric sensing, whether the sawtooth is worn, displaced or the like is monitored, and the driver is reminded in time to take countermeasures when the sawtooth is faulty, thereby improving the reliability and safety of the electric power steering system.

[0041] According to still another aspect of the present application, there is provided an electronic device, which stores a program, and the program is executed by a processor to implement the method according to any of the above embodiments.

[0042] In some embodiments, the electronic device further comprises a processor for executing the program.

[0043] The present application has at least the following advantages over the prior art:

[0044] The gear detection scheme of the present application detects the tooth profile and end face of the sawtooth through photoelectric sensing, and determines whether the sawtooth has defects such as wear and displacement, so as to accurately measure the health condition of the gear without disassembling the gear, and provide a basis for ensuring the gear transmission performance.

[0045] It should be understood that the foregoing general description and the following detailed description are only exemplary and explanatory, and are not limiting to the present application. BRIEF DESCRIPTION OF DRAWINGS

[0046] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the application. It is to be expressly understood that the drawings are only exemplary and are, therefore, not to be considered as limiting the application as described and claimed. Specifically, the following figures are described herein:

[0047] Figure 1 Fig. 1 shows a schematic diagram of the architecture of the gear detection circuit in the embodiment of the present application;

[0048] Figure 2 Fig. 2 shows a schematic diagram of the structure of the gear;

[0049] Figure 3 Fig. 3 shows a schematic diagram of the structure of the constant light emitting circuit in the embodiment of the present application;

[0050] Figure 4 Fig. 4 shows a schematic diagram of the structure of the first detection circuit in the embodiment of the present application;

[0051] Figure 5 Fig. 5 shows a schematic diagram of the structure of the second detection circuit in the embodiment of the present application;

[0052] Figure 6 Fig. 6 shows a schematic diagram of the steps of the gear detection method in the embodiment of the present application;

[0053] Figure 7 Fig. 7 shows a schematic diagram of the end face shape of the sawtooth;

[0054] Figure 8 Fig. 8 shows a schematic diagram of the steps of the gear monitoring method of the electric power steering system in the embodiment of the present application;

[0055] Figure 9 Fig. 9 shows a schematic diagram of the structure of the electronic device in the embodiment of the present application. DETAILED DESCRIPTION

[0056] Example implementations will now be described more fully with reference to the accompanying drawings. Example implementations may, however, be implemented in many different forms and should not be construed as limited to the implementations set forth herein. Rather, these implementations are provided as example embodiments so that this disclosure will be thorough and complete, and will fully convey the inventive concept to those skilled in the art.

[0057] The accompanying drawings are included to provide a further understanding of the present application, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the present application and, together with the description, serve to explain the principles of the present application. In the drawings:

[0058] The flow charts shown in the drawings are merely examples and do not necessarily include all steps. For example, some steps can be split, some steps can be combined or partially combined, and the actual execution order can be changed according to actual conditions. The terms "first", "second", and similar terms used in the description are not intended to denote any order, number, or importance, but are only used to distinguish different components. In the description of the present application, "a plurality of" means two or more, unless otherwise specifically limited. In addition, when it is said that a device is "connected" to another device, this includes not only the case of direct connection, but also the case of indirect connection through other elements.

[0059] It should be noted that the features of the embodiments of the present application and the features in different embodiments can be combined with each other without conflict.

[0060] Figure 1 The architecture module of the gear detection circuit is shown, referring to Figure 1 The gear detection circuit provided by the embodiments of the present application includes:

[0061] The constant light emitting circuit 110 includes a light source LED1 for emitting a light signal with constant light intensity;

[0062] The photoelectric conversion circuit 120 comprises: a first detection circuit 120a comprising at least one first photosensitive element PD, the first photosensitive element PD being located in the light range of the light source LED1, a first space 100a for the sawtooth to pass being formed between the first photosensitive element PD and the light source LED1, the first detection circuit 120a being configured to output a first photosensitive element PD sensing light signal and a first electric signal generated by the sawtooth profile blocking; and / or a second detection circuit 120b comprising a second photosensitive element PT1 array, the second photosensitive element PT1 array being located in the light range of the light source LED1, a second space 100b for the sawtooth to pass being formed between the second photosensitive element PT1 array and the light source LED1, the second detection circuit 120b being configured to output a second photosensitive element PT1 array sensing light signal and a second electric signal generated by the sawtooth end face projection blocking.

[0063] The constant light emitting circuit 110 emits light signals with constant light intensity, provides stable input for the photoelectric conversion circuit 120, and ensures the accuracy of the detection results of the photoelectric conversion circuit 120. The photoelectric conversion circuit 120 and the constant light emitting circuit 110 are arranged to leave a space for the sawtooth to pass, so that the gear can be detected without disassembly, and the gear can run. The first photosensitive element PD is located in the light range of the light source LED1, and a first space 100a for the sawtooth to pass is formed between the first photosensitive element PD and the light source LED1. When the first space 100a is not passed by the sawtooth, the first photosensitive element PD senses the light signal. When a sawtooth passes through the first space 100a, the tooth profile of the sawtooth blocks the light signal, and the first electric signal generated by the first photosensitive element PD changes. In this way, the change of the first electric signal output by the first detection circuit 120a can detect parameters related to the tooth profile of the sawtooth. For example, according to the duration of the changed first electric signal and the running speed of the gear, the related parameters of the tooth profile distance of the sawtooth can be obtained. The second photosensitive element PT1 array is located in the light range of the light source LED1, and a second space 100b for the sawtooth to pass is formed between the second photosensitive element PT1 array and the light source LED1. When the second space 100b is not passed by the sawtooth, the second photosensitive element PT1 array completely receives the light signal irradiation. When a sawtooth passes through the second space 100b, the end face of the sawtooth is projected to the second photosensitive element PT1 array by the light signal, so that the second electric signal generated by the second photosensitive element PT1 blocked by the end face projection changes. In this way, the change of the second electric signal output by the second detection circuit 120b can detect parameters related to the end face projection of the sawtooth. For example, according to the changed second electric signal, the second photosensitive element PT1 blocked by the end face projection is determined, and then the related parameters of the end face area of the sawtooth are determined according to the blocked second photosensitive element PT1. The tooth profile distance and the end face area related parameters of the sawtooth can effectively reflect the sawtooth, especially whether the tooth surface of the sawtooth has defects such as wear and displacement affecting the transmission performance.

[0064] The gear detection circuit of the present application detects the tooth thickness profile and end face projection of the sawtooth by photoelectric induction, and determines whether the sawtooth has defects such as wear and displacement, thereby accurately measuring the health condition of the gear without disassembling the gear, and providing a basis for ensuring the gear transmission performance.

[0065] Figure 2 The structure of the gear is shown. In combination with Figure 1 and Figure 2 As shown, the gear 200 includes a body 210 and a sawtooth 220 formed on the body 210, and the sawtooth 220 has parameters such as tooth surface, tooth profile, tooth thickness, tooth height, tooth width, end face, etc. The tooth thickness profile refers to the profile line of the tooth thickness of the sawtooth 220, and the tooth profile distance refers to the straight line distance between the tooth profiles of the sawtooth 220. During detection, the light source LED1, the detected sawtooth 220 and the first photosensitive element PD / second photosensitive element PT1 array can form a structure arranged along the tooth width direction of the detected sawtooth 220, so as to realize accurate detection of the tooth thickness profile and end face projection of the sawtooth 220. It should be noted that the middle part of the body 210 of the gear 200 also has a shaft hole, Figure 2 which is not specifically shown in the figure.

[0066] The gear detection scheme of the present application is suitable for detecting spur gears and slightly inclined helical gears. If the sawtooth inclination is too large, it may not be possible to accurately measure due to the mutual interlacing of the teeth at the end face, but it can also be used as an auxiliary measurement if necessary. The gear referred to in the present application includes internal gear and external gear, and is not limited to Figure 2 the gear shown in the figure, which forms a sawtooth on the rim, but also includes special gears such as racks, worm gears, and worm shafts.

[0067] In combination with Figure 1 and Figure 2 As shown, in some embodiments, in the case where the photoelectric conversion circuit 120 includes a first detection circuit 120a: when the corresponding sawtooth 220 passes through the first space 100a, the tooth thickness profile of the sawtooth 220 blocks the light signal of the light source LED1 irradiating the first photosensitive element PD, and the first detection circuit 120a outputs a first electric signal representing the tooth profile distance of the sawtooth 220.

[0068] The running track of the gear 200 is, for example, along a circumference R0. When no sawtooth 220 passes through the first space 100a, the first photosensitive element PD receives the light signal and outputs a high-level first electric signal; when a sawtooth 220 passes through the first space 100a, the light signal is blocked by the tooth thickness profile of the sawtooth 220, and the first photosensitive element PD outputs a low-level first electric signal; when the tooth thickness profile leaves the first space 100a, the first photosensitive element PD receives the light signal again and outputs a high-level first electric signal. In this way, according to the duration of the low-level first electric signal and the running speed of the gear 200, the related parameters of the tooth profile distance of the sawtooth 220 can be obtained.

[0069] The first detection circuit 120a can directly output the first electric signal generated by the first photosensitive element PD, or can output the first electric signal generated by the first photosensitive element PD after processing.

[0070] In some embodiments, the first photosensitive element PD includes a plurality of first photosensitive elements PD arranged along the tooth height direction of the sawtooth 220; when the corresponding sawtooth 220 passes through the first space 100a, the tooth thickness profile of each tooth height position of the sawtooth 220 respectively blocks the light signal of the plurality of first photosensitive elements PD irradiated by the light source LED1, and the first detection circuit 120a outputs the first electric signal representing the tooth profile distance of each tooth height position of the sawtooth 220.

[0071] The plurality of first photosensitive elements PD arranged along the tooth height direction of the sawtooth 220 can respectively detect the tooth profile distance of different tooth height positions of the sawtooth 220; the more the number of the first photosensitive elements PD, the more accurately the tooth profile shape of the sawtooth 220 can be fed back, and the more precise the detection result is.

[0072] Continuing to combine Figure 1 and Figure 2 As shown in FIGS. 1, 2 and 3, in some embodiments, when the photoelectric conversion circuit 120 includes a second detection circuit 120b: when the corresponding sawtooth 220 passes through the second space 100b, the light source LED1 irradiates the end face of the sawtooth 220 and projects to the second photosensitive element PT1 array, and the second detection circuit 120b outputs a second electric signal representing the area of the end face of the sawtooth 220.

[0073] When no tooth 220 passes through the second space 100b, each second photosensitive element PT1 in the second photosensitive element PT1 array receives the light signal and outputs a high-level second electric signal; when a tooth 220 passes through the second space 100b, the light signal is partially blocked by the end face projection of the tooth 220, and the blocked second photosensitive element PT1 in the second photosensitive element PT1 array outputs a low-level second electric signal; when the end face projection leaves the second space 100b, each second photosensitive element PT1 again outputs a high-level second electric signal. In this way, according to the second photosensitive element PT1 outputting a low-level second electric signal, the relevant parameters of the end face area of the tooth 220 can be obtained.

[0074] The second detection circuit 120b can directly output the second electric signal generated by the second photosensitive element PT1, or can output the second electric signal generated by the second photosensitive element PT1 after processing.

[0075] The principle of detecting the tooth profile distance of the tooth 220 by the first detection circuit 120a is similar to the principle of detecting the end face area of the tooth 220 by the second detection circuit 120b, and the difference lies in that each first photosensitive element PD forms a “detection point”, and when the tooth 220 passes through the first space 100a, the light signal of the first photosensitive element PD is blocked by the tooth thickness profile of the tooth 220, so that the first detection circuit 120a detects the linear tooth profile distance; the second photosensitive element PT1 array forms a “detection surface”, and when the tooth 220 passes through the second space 100b, part of the light signal received by the second photosensitive element PT1 is blocked by the end face projection of the tooth 220, so that the second detection circuit 120b detects the area of the surface-shaped end face.

[0076] In some embodiments, the light source LED1 is a parallel light source; in the case where the photoelectric conversion circuit 120 includes the first detection circuit 120a: the parallel light source vertically irradiates the first photosensitive element PD; when the corresponding tooth 220 passes through the first space 100a, the parallel light source, the tooth 220 and the first photosensitive element PD are arranged along the tooth width direction of the tooth 220; in the case where the photoelectric conversion circuit 120 includes the second detection circuit 120b: the parallel light source vertically irradiates the second photosensitive element PT1 array; when the corresponding tooth 220 passes through the second space 100b, the parallel light source, the tooth 220 and the second photosensitive element PT1 array are arranged along the tooth width direction of the tooth 220.

[0077] The parallel light source vertically irradiates the first photosensitive element PD / second photosensitive element PT1 array, and when detecting the tooth profile distance / end surface area of a sawtooth 220, the parallel light source, the sawtooth 220 and the first photosensitive element PD / second photosensitive element PT1 array are arranged along the tooth width direction of the sawtooth 220, so that the detection result accurately reflects the tooth profile distance / end surface area, and whether the sawtooth 220 has defects such as wear and displacement is determined according to the detection result, thereby ensuring the accuracy and reliability of the detection.

[0078] Figure 1 The gear detection circuit of the present application shown can be assembled together with the gear in the transmission system. In the initial stage of use of the gear, the initial first electrical signal representing the tooth profile distance of each sawtooth / the initial second electrical signal representing the end surface area of each sawtooth can be recorded; and as the use goes on, when the change of the first electrical signal representing the tooth profile distance of a sawtooth / the second electrical signal representing the end surface area of a sawtooth exceeds the set range, it can be considered that the sawtooth has defects such as wear and displacement that affect its transmission performance.

[0079] In some implementation scenarios, the light source LED1 can also obliquely irradiate the first photosensitive element PD / second photosensitive element PT1 array due to the limitation of space arrangement; at this time, the obtained detection result does not directly reflect the tooth profile distance / end surface area of the sawtooth, but the determination of whether the sawtooth has defects such as wear and displacement that affect its transmission performance can still be made through the judgment of whether the change of the first electrical signal representing the tooth profile distance of a sawtooth / the second electrical signal representing the end surface area of a sawtooth exceeds the set range.

[0080] Figure 3 The structure of the constant light emitting circuit is shown; in combination with Figure 1 and Figure 3 As shown, in some embodiments, the constant light emitting circuit 110 includes a negative feedback circuit 111, and the light source LED1 is connected with the output end of the negative feedback circuit 111.

[0081] The negative feedback circuit 111 can stabilize the output voltage, and then drive the light source LED1 to emit a light signal with constant light intensity. In other embodiments, in addition to the negative feedback circuit 111, a filter circuit, a voltage stabilizing circuit, etc. can also be used to drive the light source LED1 to emit a light signal with constant light intensity.

[0082] In some embodiments, the negative feedback circuit 111 includes: a first operational amplifier U1, the non-inverting input end of the first operational amplifier U1 inputs a constant voltage; a first triode Q1, the control end of the first triode Q1 is connected with the output end of the first operational amplifier U1; and a first output loop including the light source LED1, the first triode Q1 and a sampling resistor R3 connected in series, and the series connection node of the sampling resistor R3 and the first triode Q1 is connected with the inverting input end of the first operational amplifier U1.

[0083] The first operational amplifier U1 and the first triode Q1 constitute a main part of the negative feedback circuit 111, and the sampling resistor R3 feeds back the current of the first output loop in which the light source LED1 is located in real time (the power supply voltage of the first output loop is Vcc). The current of the first output loop is kept constant through the adjustment of the first operational amplifier U1 and the first triode Q1, so that the light source LED1 emits light signals with constant light intensity. The light source LED1 can be a light-emitting diode, but is not limited thereto. When the current of the first output loop increases, the voltage at the inverting input terminal of the first operational amplifier U1 increases, and the difference between the inverting input terminal and the non-inverting input terminal decreases, so that the differential voltage output by the first operational amplifier U1 decreases, resulting in a decrease in the current at the base of the first triode Q1, so that the internal resistance of the first triode Q1 increases, the voltage drop between the emitter and the collector increases, and the current of the first output loop decreases. When the current of the first output loop decreases, the voltage at the inverting input terminal of the first operational amplifier U1 decreases, and the difference between the inverting input terminal and the non-inverting input terminal increases, so that the differential voltage output by the first operational amplifier U1 increases, resulting in an increase in the current at the base of the first triode Q1, so that the internal resistance of the first triode Q1 decreases, the voltage drop between the emitter and the collector decreases, and the current of the first output loop increases. In this way, the current of the first output loop is fed back in real time through the sampling resistor R3 and adjusted by the first operational amplifier U1 and the first triode Q1, and finally reaches a constant stable current.

[0084] In some embodiments, the negative feedback circuit 111 further comprises a first current-limiting resistor R4 connected in series between the output terminal of the first operational amplifier U1 and the base, i.e., the control terminal, of the first triode Q1. The first current-limiting resistor R4 plays a current-limiting protection role for the first triode Q1.

[0085] In some embodiments, the constant light-emitting circuit 110 further comprises a shaping circuit 112 connected between the pulse signal input terminal IN and the non-inverting input terminal of the first operational amplifier U1. The shaping circuit 112 comprises: first and second resistors R1 and R2 connected in parallel, the first ends of the first and second resistors R1 and R2 being connected to the pulse signal input terminal IN, and the second end of the first resistor R1 being grounded; and first and second capacitors C1 and C2 connected in parallel, the first ends of the first and second capacitors C1 and C2 being connected to the second end of the second resistor R2 and the non-inverting input terminal of the first operational amplifier U1, respectively, and the second ends of the first and second capacitors C1 and C2 being grounded.

[0086] The shaping circuit 112 is used to shape the pulse signal into a stable direct current voltage, which is provided to the negative feedback circuit 111, so that the negative feedback circuit 111 adjusts the stable current to generate a constant light of the light source LED1. The shaping circuit 112 can quickly and stably shape the pulse signal inputted from the pulse signal input end IN into a direct current voltage through the large-capacitance charging and discharging characteristics of the first capacitor C1 and the second capacitor C2, in cooperation with the first resistor R1 and the second resistor R2. Wherein, when the gear detection scheme is applied to the vehicle, the pulse signal can be a rectangular wave with a duty cycle of N and a peak value of U transmitted from the central processing unit (CPU) port; after the shaping processing of the shaping circuit 112, the rectangular wave gradually becomes direct current, and the direct current voltage amplitude is (U×N) V. The direct current voltage is output to the above-mentioned negative feedback circuit 111, and then the current for driving the light source LED1 to generate constant light can be obtained as follows: I=(U×N)÷R3.

[0087] Figure 4 The structure of the first detection circuit is shown; in combination with Figure 1 and Figure 4 In some embodiments, in the case that the photoelectric conversion circuit 120 includes the first detection circuit 120a, the first detection circuit 120a includes at least one first sub-detection circuit 122 including each first photosensitive element PD, and each first sub-detection circuit 122 includes: a second operational amplifier U2, the first photosensitive element PD is connected between the two input ends of the second operational amplifier U2; a second output circuit including an optocoupler chip and a second transistor Q2, the light emitting element LED2 of the optocoupler chip is connected in series with the second transistor Q2, the control end of the second transistor Q2 is connected to the output end of the second operational amplifier U2, and the photosensitive element PT2 of the optocoupler chip is connected to the output end OUT1 of the first sub-detection circuit 122.

[0088] The potential difference generated across the first photosensitive element PD is amplified by the second operational amplifier U2, the change of the electric signal generated by the first photosensitive element PD due to the tooth profile of the sawtooth 220 when the sawtooth 220 passes through the first space 100a is accurately collected, and the optocoupler chip is driven to work, so that the second output circuit outputs the first electric signal accurately representing the distance between the tooth profiles of the sawtooth 220.

[0089] The first light-sensitive element PD can include a plurality of elements arranged along the tooth height direction of the sawtooth 220. Each first light-sensitive element PD is located in a first sub-detection circuit 122 for detecting the tooth profile distance of the corresponding tooth height position of the sawtooth 220. In each first sub-detection circuit 122: when the light signal transmitted by the light source LED1 is not blocked by the sawtooth 220, the first light-sensitive element PD is turned on, a potential difference is generated between the two ends, the second operational amplifier U2 outputs a high level, and the second transistor Q2 is turned on. The current flows from the power supply terminal Vcc through the light-emitting element LED2 of the optocoupler chip to the ground. The light-sensitive element PT2 in the optocoupler chip senses the light emitted by the light-emitting element LED2 and works in the on state. The output terminal OUT1 of the first sub-detection circuit 122 outputs a high level. When the light signal transmitted by the light source LED1 is blocked by the sawtooth 220, the first light-sensitive element PD is turned off, and no potential difference is generated between the two ends. The second operational amplifier U2 outputs a low level, and the second transistor Q2 works in the off state. The light-emitting element LED2 in the optocoupler chip does not work. At this time, the light-sensitive element PT2 in the optocoupler chip is in the off state, and the output terminal OUT1 of the first sub-detection circuit 122 outputs a low level.

[0090] It should be noted that in the specific circuit implementation, the "light source" and "light-emitting element" described in the above embodiments and to be described in the following embodiments can be a light-emitting diode or any electronic element capable of emitting light and capable of being applied in the corresponding circuit module to realize the functions as described in the present application. Similarly, the "light-sensitive element" can be a light-sensitive diode, a light-sensitive transistor, and any electronic element with light-sensitive effect and capable of being applied in the corresponding circuit module to realize the functions as described in the present application. In addition, the "transistor" can be an NPN transistor, a PNP transistor, a crystal transistor, or any suitable transistor device capable of being applied in the corresponding circuit module to realize the functions as described in the present application.

[0091] In some embodiments, each first sub-detection circuit 122 further includes any of the following electronic elements: a second current-limiting resistor R5 connected in series between the light-emitting element LED2 of the optocoupler chip and the second transistor Q2; a third current-limiting resistor R6 connected in series with the light-sensitive element PT2 of the optocoupler chip; and a pull-up resistor R7 connected between the power supply terminal Vcc and the output terminal of the second operational amplifier U2.

[0092] The second current-limiting resistor R5 and the third current-limiting resistor R6 are respectively used for current-limiting protection in the corresponding circuit. The pull-up resistor R7 is used to stabilize the output of the second operational amplifier U2 and avoid oscillation.

[0093] Further, in some embodiments, in the case that the photoelectric conversion circuit 120 comprises the first detection circuit 120a: the first light-sensitive element PD and the light source LED1 are arranged in an enclosed space, and the first space 100a is located in the enclosed space. In this way, the transmission of the light signal between the light source LED1 and the first light-sensitive element PD is ensured to be stable, thereby ensuring accurate detection of the distance between the tooth profiles of the saw blade 220.

[0094] Figure 5 The structure of the second detection circuit is shown; in combination with Figure 1 and Figure 5 In some embodiments, in the case that the photoelectric conversion circuit 120 comprises the second detection circuit 120b, the second detection circuit 120b comprises a plurality of second sub-detection circuits 124 each comprising a respective second light-sensitive element PT1, and each second sub-detection circuit 124 comprises: a third operational amplifier U3, the second light-sensitive element PT1 being connected between the two input terminals of the third operational amplifier U3; and a third output loop comprising a fourth current-limiting resistor R8 and a third transistor Q3 connected in series, the control terminal of the third transistor Q3 being connected to the output terminal of the third operational amplifier U3, and the node of the fourth current-limiting resistor R8 and the third transistor Q3 being connected to the output terminal OUT2 of the second sub-detection circuit 124.

[0095] The potential difference generated across the second light-sensitive element PT1 is amplified by the third operational amplifier U3, and the change in the electrical signal generated by the second light-sensitive element PT1 when the saw blade 220 passes through the second space 100b due to the projection of the end face of the saw blade 220 is accurately collected, and the third output loop is driven to work, so that the third output loop outputs a second electrical signal accurately representing the area of the end face of the saw blade 220.

[0096] In some embodiments, in the case that the photoelectric conversion circuit 120 comprises the second detection circuit 120b, the second detection circuit 120b comprises a plurality of second sub-detection circuits 124 each comprising a respective second light-sensitive element PT1, and each second sub-detection circuit 124 comprises: a third operational amplifier U3, the second light-sensitive element PT1 being connected between the two input terminals of the third operational amplifier U3; and a third output loop comprising a fourth current-limiting resistor R8 and a third transistor Q3 connected in series, the control terminal of the third transistor Q3 being connected to the output terminal of the third operational amplifier U3, and the node of the fourth current-limiting resistor R8 and the third transistor Q3 being connected to the output terminal OUT2 of the second sub-detection circuit 124. C OUT2 In some embodiments, in the case that the photoelectric conversion circuit 120 comprises the second detection circuit 120b, the second detection circuit 120b comprises a plurality of second sub-detection circuits 124 each comprising a respective second light-sensitive element PT1, and each second sub-detection circuit 124 comprises: a third operational amplifier U3, the second light-sensitive element PT1 being connected between the two input terminals of the third operational amplifier U3; and a third output loop comprising a fourth current-limiting resistor R8 and a third transistor Q3 connected in series, the control terminal of the third transistor Q3 being connected to the output terminal of the third operational amplifier U3, and the node of the fourth current-limiting resistor R8 and the third transistor Q3 being connected to the output terminal OUT2 of the second sub-detection circuit 124.​C Conversely, if the second photosensitive element PT1 generates a low-level signal, the third triode Q3 works in the cutoff state, and the output end OUT2 of the third output circuit outputs a low-voltage signal. The controller can determine whether the overall shape of the end face of the sawtooth 220 changes by detecting the signal of the output end OUT2 of the third output circuit of each second sub-detection circuit 124.

[0097] Further, in some embodiments, in the case where the photoelectric conversion circuit 120 comprises the second detection circuit 120b: the array of second photosensitive elements PT1 and the light source LED1 are arranged in an enclosed space, and the second space 100b is located in the enclosed space. In this way, the stable transmission of light signals between the light source LED1 and the second photosensitive element PT1 is ensured, and in turn, the accurate detection of the end face area of the sawtooth 220 is ensured.

[0098] The embodiments of the present application also provide a gear detection method, which is implemented based on the gear detection circuit described in any of the above embodiments. The features and principles of the gear detection circuit described in any of the above embodiments can be applied to the following embodiments of the gear detection method.

[0099] Figure 6 The main steps of the gear detection method are illustrated; referring to Figure 6 , and in combination with Figures 1 to 5 , the gear detection method provided by the embodiments of the present application comprises:

[0100] S610, the gear is arranged between the constant light emitting circuit and the photoelectric conversion circuit, and the gear is controlled to run so that each sawtooth of the gear passes through the light range of the constant light emitting circuit in turn;

[0101] S620, according to the electrical signal output by the photoelectric conversion circuit, the detection result of each sawtooth of the gear is obtained, comprising: S620a, in the case where the photoelectric conversion circuit comprises the first detection circuit: according to the first electrical signal output by the first detection circuit, the first detection data representing the distance between the tooth profiles of each sawtooth is obtained, and according to the first detection data, the first detection result of whether the corresponding sawtooth is faulty is obtained; S620b, in the case where the photoelectric conversion circuit comprises the second detection circuit: according to the second electrical signal output by the second detection circuit, the second detection data representing the end face area of each sawtooth is obtained, and according to the second detection data, the second detection result of whether the corresponding sawtooth is faulty is obtained.

[0102] The tooth profile distance of the sawtooth and the end surface area related parameter can effectively reflect the sawtooth, and especially whether the tooth surface of the sawtooth has defects such as wear and displacement affecting the transmission performance. The gear detection circuit detects the tooth thickness profile and the end surface projection of the sawtooth through photoelectric induction, and determines whether the sawtooth has defects such as wear and displacement, so that the health condition of the gear is accurately measured without disassembling the gear, and a basis for ensuring the transmission performance of the gear is provided.

[0103] In some embodiments, when the gear is a gear rotating, the first detection data characterizing the tooth profile distance of each sawtooth is obtained by calculating the tooth profile distance L AB , of a tooth height position of a sawtooth, wherein the initial tooth profile distance of the tooth height position of the sawtooth and the center point of the gear form an isosceles triangle, L OB is the leg length of the isosceles triangle, w is the rotating speed of the gear, and t1 is the time when the first photosensitive element at the corresponding tooth height position is blocked by the tooth thickness profile at the tooth height position.

[0104] Figure 7 The end surface shape of the sawtooth is schematically shown. Figure 2 The end surface shape of the sawtooth of the gear is schematically shown as Figure 7 . In the initial stage of use of the gear 200, the tooth profile distance of each tooth height position of the sawtooth 220 and the center point O of the gear 200 form an isosceles triangle, and the tooth profile distance of each tooth height position is detected by the first photosensitive element corresponding to each tooth height position. For example, the tooth profile distance L AB of the top tooth height position and the center point O of the gear 200 form an isosceles triangle, and the tooth profile distance L AB is detected by the first photosensitive element arranged at the top tooth height position; the tooth profile distance L CD of the middle tooth height position and the center point O of the gear 200 form an isosceles triangle, and the tooth profile distance L CD is detected by the first photosensitive element arranged at the middle tooth height position; the tooth profile distance L EF of the bottom tooth height position and the center point O of the gear 200 form an isosceles triangle, and the tooth profile distance L EF is detected by the first photosensitive element arranged at the bottom tooth height position. The leg length L OB of the isosceles triangle, that is, the distance between the tooth profile top point B and the center point O of the gear 200, is a known parameter of the gear 200; in combination with the rotating speed w of the gear 200 and the time t1 when the first photosensitive element at the corresponding tooth height position is blocked by the tooth thickness profile at the tooth height position, the tooth profile distance L AB of the sawtooth 220 at the tooth height position is calculated by using the Pythagorean theorem.

[0105] The tooth profile distance LCD and L EF The calculation process is the same. wherein L OD is the leg length of the isosceles triangle of the middle tooth height position, i.e. the distance between the middle tooth profile point D and the center point O of the gear 200, which is a known parameter of the gear 200; t2 is the time for the first photosensitive element at the middle tooth height position to be shielded by the tooth thickness profile at the tooth height position. wherein L OF is the leg length of the isosceles triangle of the bottom tooth height position, i.e. the distance between the bottom tooth profile point F and the center point O of the gear 200, which is a known parameter of the gear 200; t3 is the time for the first photosensitive element at the bottom tooth height position to be shielded by the tooth thickness profile at the tooth height position.

[0106] When the gear is a gear for linear motion, the tooth profile distance of the sawtooth at the tooth height position can be directly obtained according to the running speed of the gear and the time for the first photosensitive element at the corresponding tooth height position to be shielded by the tooth thickness profile of the sawtooth at the tooth height position.

[0107] In some embodiments, obtaining the first detection result of whether the corresponding sawtooth is faulty according to the first detection data comprises: comparing the first detection data of each sawtooth with a first abnormal reference range and / or a first fault reference range; determining that a sawtooth is abnormal when the first detection data of the sawtooth falls within the first abnormal reference range; determining that a sawtooth is faulty when the sawtooth is determined to be abnormal continuously for multiple times; and determining that a sawtooth is faulty when the first detection data of the sawtooth falls within the first fault reference range.

[0108] When the first detection data of a sawtooth falls within the first abnormal reference range, it indicates that the tooth profile distance of the sawtooth is abnormal (for example, the tooth surface of the sawtooth is notched or the gear is displaced), and the sawtooth may be faulty. To avoid errors caused by single test, when a sawtooth is determined to be abnormal continuously for multiple times (for example, 10-40 times), it is determined that the sawtooth is faulty. When the first detection data of a sawtooth falls within the first fault reference range, it indicates that the tooth profile distance of the sawtooth has deviated from the initial value seriously (for example, the sawtooth is seriously damaged or even falls off), and thus it is determined that the sawtooth is faulty.

[0109] In some embodiments, the second detection data characterizing the end face area of each sawtooth is obtained by: when the corresponding sawtooth passes through the second space, determining the shielded second photosensitive elements according to the electrical signals output by the second photosensitive elements in the second photosensitive element array; and determining the end face area of the sawtooth according to the shielded second photosensitive elements.

[0110] The light source, the detected sawtooth and the second photosensitive element array can be arranged along the tooth width direction of the detected sawtooth, and the second photosensitive element array can be consistent with the initial size of the sawtooth in the tooth thickness direction, so as to facilitate the detection of the end face area of the sawtooth. When a sawtooth passes through the second space, the end face of the sawtooth is projected onto the second photosensitive element array by the light signal, and according to the area of the second photosensitive element blocked by the projection of the end face of the sawtooth, the end face area of the sawtooth can be determined.

[0111] In some embodiments, the second detection result of whether the corresponding sawtooth is faulty is obtained according to the second detection data, including: comparing the second detection data of each sawtooth with the second abnormal reference range and / or the second fault reference range; when the second detection data of a sawtooth falls within the second abnormal reference range, determining that the sawtooth is abnormal; when a sawtooth is determined to be abnormal for a plurality of times in succession, determining that the sawtooth is faulty; and when the second detection data of a sawtooth falls within the second fault reference range, determining that the sawtooth is faulty.

[0112] When the second detection data of a sawtooth falls within the second abnormal reference range, it indicates that the end face area of the sawtooth is abnormal (for example, the tooth surface of the sawtooth has a notch or the gear has a displacement), and the sawtooth may be faulty. In order to avoid errors caused by single test, when a sawtooth is determined to be abnormal for a plurality of times in succession (for example, 10-40 times in succession), it is determined that the sawtooth is faulty. When the second detection data of a sawtooth falls within the second fault reference range, it indicates that the end face area of the sawtooth has deviated from the initial value seriously (for example, the sawtooth has a shedding or a serious defect), and thus it is determined that the sawtooth is faulty.

[0113] In some embodiments, if the first detection result indicates that two or more sawteeth are faulty when the photoelectric conversion circuit includes the first detection circuit; and / or, if the second detection result indicates that two or more sawteeth are faulty when the photoelectric conversion circuit includes the second detection circuit; and / or, if the first detection result and the second detection result indicate that the same sawtooth is faulty when the photoelectric conversion circuit includes the first detection circuit and the second detection circuit, it is determined that the gear is faulty.

[0114] Two or more sawteeth are faulty, a plurality of parameters of the same sawtooth are seriously abnormal, and the like, which can seriously affect the transmission performance of the gear, and thus it is determined that the gear is faulty.

[0115] The embodiments of the present application also provide a gear monitoring method of an electric power steering system, which is implemented based on the gear detection method described in any of the above embodiments. The features and principles of the gear detection method described in any of the above embodiments can be applied to the following embodiments of the gear monitoring method of the electric power steering system.

[0116] Figure 8 The main steps of the gear monitoring method of the electric power steering system are illustrated; refer to Figure 8 , and combineFigures 1 to 7 The gear monitoring method of the electric power steering system provided by the embodiment of the application comprises:

[0117] S810, when the detection result indicates at least one sawtooth fault, issuing an alarm containing the detection result;

[0118] S820, when the vehicle is next started, if the alarm is not eliminated, controlling the electric power steering system to refuse to provide assistance.

[0119] The detection result comprises a first detection result of whether the sawtooth is faulty detected by the first detection circuit based on the tooth profile distance of the sawtooth, and / or a second detection result of whether the sawtooth is faulty detected by the second detection circuit based on the end surface area of the sawtooth. The gear detection method is used to detect the gear of the electric power steering system, the tooth profile and the end surface of the sawtooth during the operation of the gear are detected through photoelectric sensing, whether the sawtooth is worn or displaced is monitored, and the driver is reminded to take measures in time when the sawtooth is faulty, thereby improving the reliability and safety of the electric power steering system.

[0120] The gear monitoring method of the electric power steering system can be executed by the controller of the electric power steering system or the controller of the whole vehicle. During the operation of the electric power steering system, the gear detection circuit works continuously, and the controller can calculate the tooth profile distance / end surface area of each sawtooth of the gear according to the set frequency (for example, 10-10000 times / s, preferably 100-1000 times / s), and determine whether the corresponding sawtooth is abnormal / faulty and whether the gear is faulty; when it is determined that there are two or more sawtooth faults, multiple parameters of the same sawtooth are seriously abnormal, or the like, the controller issues an alarm to remind the driver to check the gear condition of the electric power steering system; when the vehicle is next started, if the controller checks that the gear state has been improved, the electric power steering system normally provides assistance, and if the alarm is not eliminated or the controller checks that the gear state has not been improved, the electric power steering system is controlled to refuse to provide assistance.

[0121] The embodiment of the application further provides an electronic device which stores a program, and when the program is executed by a processor, the gear detection method described in any of the embodiments and / or the gear monitoring method of the electric power steering system described in any of the embodiments is implemented.

[0122] When the gear detection scheme is applied to the electric power steering system, the electronic device can be communicatively connected with the controller of the electric power steering system or the controller of the whole vehicle, so as to monitor the health condition of the gear of the electric power steering system.

[0123] When implemented specifically, the electronic device can have the following three forms.

[0124] The gear detection method / epas gear monitoring method described in any of the above embodiments can be formed in the form of a function (program) module architecture, which can include modules respectively implementing each step of the gear detection method / epas gear monitoring method described above, such as function modules for implementing steps S610, S620, S810, and S820.

[0125] The gear detection method / epas gear monitoring method described in any of the above embodiments can be formed in the form of a computer program product, which includes a computer program that is executed by a processor to implement the gear detection method / epas gear monitoring method described in any of the above embodiments.

[0126] The gear detection method / epas gear monitoring method described in any of the above embodiments can be formed in the form of a computer program product, which includes a computer program that is executed by a processor to implement the gear detection method / epas gear monitoring method described in any of the above embodiments.

[0127] In some embodiments, the electronic device further includes a processor for executing the program.

[0128] When the gear detection scheme is applied to an epas, the electronic device can be a controller of the epas or a controller of the whole vehicle, which can detect the tooth profile and end face of the sawtooth during the operation of the gear through photoelectric sensing, monitor whether the sawtooth has defects such as wear and displacement, and timely remind the driver to take countermeasures when the sawtooth fault is detected, thereby improving the reliability and safety of the epas.

[0129] Figure 9 The structure of the electronic device in the embodiment is shown schematically; refer to Figure 9As shown, the electronic device 900 can be formed in the form of a general computing device, which includes a processing unit 910 and a storage unit 920 in which executable instructions are stored, and the executable instructions are executed by the processing unit 910 to implement the gear detection method / electric power steering system gear monitoring method described in any of the embodiments. The storage unit 920 can include programs / utilities with one or more program modules, including but not limited to: an operating system, one or more application programs, other program modules, and program data. The general computing device also includes a bus 930 connecting the processing unit 910 and the storage unit 920, and other platform components, which can include a storage unit bus, a peripheral bus, a graphics acceleration port, a processing unit bus, and the like. The general computing device can also communicate with one or more external devices, other computing devices of the vehicle, networks (such as a local area network LAN, a wide area network WAN, and / or a public network such as the Internet), and the like.

[0130] The above is a further detailed description of the present application in combination with specific preferred embodiments, and cannot be considered as limiting the specific implementation of the present application to these descriptions. For those of ordinary skill in the art to which the present application belongs, without departing from the concept of the present application, a number of simple deductions or substitutions can also be made, which should be considered as falling within the protection scope of the present application.

Claims

1. An electric power assisted steering system comprising a gear detection circuit, characterised in that, The gear detection circuit comprises: The constant light emitting circuit comprises a parallel light source for emitting a light signal with constant light intensity; The photoelectric conversion circuit comprises: The first detection circuit comprises a plurality of first photosensitive elements, the first photosensitive elements are located in the light range of the parallel light source, the parallel light source vertically irradiates the first photosensitive elements, a first space for the sawtooth of the gear to pass through is formed between the parallel light source and the first photosensitive elements, and the first detection circuit is used for outputting the first electric signal generated by the first photosensitive elements sensing the light signal and being shielded by the tooth thickness profile of the sawtooth; Wherein, the plurality of first photosensitive elements are arranged along the tooth height direction of the sawtooth to respectively detect the tooth profile distance of different tooth height positions of the sawtooth; when the corresponding sawtooth passes through the first space, the parallel light source, the sawtooth and the first photosensitive elements are arranged along the tooth width direction of the sawtooth, the tooth thickness profile of each tooth height position of the sawtooth respectively shields the light signal of the parallel light source irradiating the plurality of first photosensitive elements, and the first detection circuit outputs the first electric signal representing the tooth profile distance of each tooth height position of the sawtooth; The second detection circuit comprises a second photosensitive element array, the second photosensitive element array is located in the light range of the parallel light source, the parallel light source vertically irradiates the second photosensitive element array, a second space for the sawtooth to pass through is formed between the second photosensitive element array and the parallel light source, and the second detection circuit is used for outputting the second electric signal generated by the second photosensitive element array sensing the light signal and being shielded by the end face projection of the sawtooth; Wherein, the second photosensitive element array is consistent with the initial size of the sawtooth in the tooth thickness direction of the sawtooth; when the corresponding sawtooth passes through the second space, the parallel light source, the sawtooth and the second photosensitive element array are arranged along the tooth width direction of the sawtooth, the parallel light source irradiates the end face of the sawtooth and projects to the second photosensitive element array, and the second detection circuit outputs the second electric signal representing the end face area of the sawtooth; Wherein, the gear of the electric power steering system is arranged between the constant light emitting circuit and the photoelectric conversion circuit, and in the running process of the electric power steering system: each sawtooth of the gear passes through the light range of the constant light emitting circuit in turn, and the first detection circuit and the second detection circuit respectively output the first electric signal and the second electric signal; when the first electric signal represents the failure of two or more sawteeth, and / or the second electric signal represents the failure of two or more sawteeth, and / or the first electric signal and the second electric signal represent the failure of the same sawtooth, it is determined that the gear is faulty.

2. The electric power assisted steering system of claim 1, wherein, The constant light emitting circuit comprises a negative feedback circuit, and the parallel light source is connected with the output end of the negative feedback circuit.

3. An electric power assisted steering system as claimed in claim 2, characterised in that, The negative feedback circuit comprises: A first operational amplifier, a constant voltage is input to the non-inverting input end of the first operational amplifier; A first triode, the control end of the first triode is connected with the output end of the first operational amplifier; The first output circuit comprises the parallel light source, the first triode and a sampling resistor connected in series, and the sampling resistor is connected to the inverting input terminal of the first operational amplifier at the series node of the first triode.

4. An electric power assisted steering system as claimed in claim 3, characterised in that, The constant light emitting circuit further comprises a shaping circuit connected between the pulse signal input terminal and the non-inverting input terminal of the first operational amplifier, and the shaping circuit comprises: a first resistor and a second resistor connected in parallel, first ends of the first resistor and the second resistor are connected to the pulse signal input terminal, and a second end of the first resistor is grounded; a first capacitor and a second capacitor connected in parallel, first ends of the first capacitor and the second capacitor are connected to the second end of the second resistor and the non-inverting input terminal of the first operational amplifier, and second ends of the first capacitor and the second capacitor are grounded.

5. The electric power assisted steering system of claim 1 wherein, In the case that the photoelectric conversion circuit comprises the first detection circuit, the first detection circuit comprises at least one first sub-detection circuit comprising a first photosensitive element respectively, each first sub-detection circuit comprises: a second operational amplifier, the first photosensitive element is connected between two input terminals of the second operational amplifier; a second output circuit comprising an optocoupler chip and a second triode, the light emitting element of the optocoupler chip is connected in series with the second triode, the control terminal of the second triode is connected to the output terminal of the second operational amplifier, and the photosensitive element of the optocoupler chip is connected to the output terminal of the first sub-detection circuit.

6. An electric power assisted steering system as claimed in claim 5, characterised in that, Each first sub-detection circuit further comprises any of the following electronic elements: a second current limiting resistor connected in series between the light emitting element of the optocoupler chip and the second triode; a third current limiting resistor connected in series with the photosensitive element of the optocoupler chip; a pull-up resistor connected between the power supply terminal and the output terminal of the second operational amplifier.

7. The electric power assisted steering system of claim 1 wherein, In the case that the photoelectric conversion circuit comprises the second detection circuit, the second detection circuit comprises a plurality of second sub-detection circuits comprising a second photosensitive element respectively, each second sub-detection circuit comprises: a third operational amplifier, the second photosensitive element is connected between two input terminals of the third operational amplifier; a third output circuit comprising a fourth current limiting resistor and a third triode connected in series, the control terminal of the third triode is connected to the output terminal of the third operational amplifier, and the fourth current limiting resistor is connected to the output terminal of the second sub-detection circuit at the series node of the third triode.

8. A gear inspection method characterized by, The electric power steering system is implemented based on any one of claims 1-7, comprising: a gear is arranged between the constant light emitting circuit and the photoelectric conversion circuit, and the gear is controlled to operate so that each sawtooth of the gear passes through the light range of the constant light emitting circuit in turn; the detection results of each sawtooth of the gear are obtained according to the electrical signals output by the photoelectric conversion circuit, comprising: first detection data representing the distance between tooth profiles of each sawtooth are obtained according to the first electrical signals output by the first detection circuit, and first detection results of whether the corresponding sawtooth is faulty are obtained according to the first detection data; According to the second electrical signal output by the second detection circuit, second detection data representing the end surface area of each sawtooth is obtained, and a second detection result indicating whether the corresponding sawtooth is faulty is obtained according to the second detection data; If the first detection result indicates that two or more sawteeth are faulty, and / or if the second detection result indicates that two or more sawteeth are faulty, and / or if the first detection result and the second detection result indicate that the same sawtooth is faulty, it is determined that the gear is faulty.

9. The gear inspection method of claim 8, wherein, When the gear is a gear that rotates, the first detection data representing the distance between tooth profiles of each sawtooth is obtained by: calculating a tooth profile distance L at a tooth height position of a sawtooth AB , wherein an initial tooth profile distance at the tooth height position of the sawtooth and a gear center point form an isosceles triangle, L OB is a leg length of the isosceles triangle, w is a rotational speed of the gear, and t1 is a time for a first photosensitive element at a corresponding tooth height position to be shielded by a tooth thickness profile at the tooth height position.

10. The gear inspection method of claim 8, wherein, The first detection result indicating whether the corresponding sawtooth is faulty is obtained according to the first detection data by: The first detection data of each sawtooth is compared with a first abnormal reference range and / or a first fault reference range; When the first detection data of a sawtooth falls within the first abnormal reference range, it is determined that the sawtooth is abnormal; when a sawtooth is determined to be abnormal for multiple times in succession, it is determined that the sawtooth is faulty; When the first detection data of a sawtooth falls within the first fault reference range, it is determined that the sawtooth is faulty.

11. The gear inspection method of claim 8, wherein, The second detection data representing the end surface area of each sawtooth is obtained by: When the corresponding sawtooth passes through the second space, the second photosensitive elements that are blocked are determined according to the electrical signals output by the second photosensitive elements in the second photosensitive element array; The end surface area of the sawtooth is determined according to the second photosensitive elements that are blocked.

12. The gear inspection method of claim 8, wherein, The second detection result indicating whether the corresponding sawtooth is faulty is obtained according to the second detection data by: The second detection data of each sawtooth is compared with a second abnormal reference range and / or a second fault reference range; When the second detection data of a sawtooth falls within the second abnormal reference range, it is determined that the sawtooth is abnormal; when a sawtooth is determined to be abnormal for multiple times in succession, it is determined that the sawtooth is faulty; When the second detection data of a sawtooth falls within the second fault reference range, it is determined that the sawtooth is faulty.

13. A method of monitoring a gear of an electric power assisted steering system, characterized in that, Based on the gear detection method as claimed in any one of claims 8-12, comprising: When the detection result indicates that at least one sawtooth is faulty, an alarm containing the detection result is sent out; If the alarm has not been eliminated when the vehicle is next started, the electric power steering system is controlled to refuse to provide assistance.

14. An electronic device, comprising: The electronic device stores a program, and the program is executed by a processor to implement the method as claimed in any one of claims 8-13.

15. The electronic device of claim 14, wherein, The electronic device further comprises a processor for executing the program. The electronic device stores a program, and the program is executed by a processor to implement the method as claimed in any one of claims 8-13.

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