阅读说明：本技术 一种缝纫机的布料检测方法及系统 (Cloth detection method and system of sewing machine ) 是由 朱良华 徐永明 于 2018-07-23 设计创作，主要内容包括：本发明公开了一种缝纫机的布料检测方法及系统,该方法包括：当与红外光接收电路中的红外光敏二极管对射的红外发射二极管启动时,接收红外光接收电路发送的第一采样信号；当红外发射二极管关闭时,接收红外光接收电路发送的第二采样信号；生成第一采样信号对应的第一红外光能量和第二采样信号对应的第二红外光能量,并计算第一红外光能量与第二红外光能量的差值；根据差值和预设红外光能量的比较,确定红外光敏二极管的对应位置是否存在布料；本发明可以有效去掉环境中的红外光对布料检测的干扰,且减少布料检测的时间,有利于缝纫机剪线时控制线辫长度；并且通过红外光敏二极管的设置,可以更准确的感应光强度,提高布料检测的准确性。(The invention discloses a cloth detection method and a system of a sewing machine, wherein the method comprises the following steps: when an infrared emitting diode opposite to an infrared photosensitive diode in an infrared light receiving circuit is started, receiving a first sampling signal sent by the infrared light receiving circuit; when the infrared emitting diode is closed, receiving a second sampling signal sent by the infrared light receiving circuit; generating first infrared light energy corresponding to the first sampling signal and second infrared light energy corresponding to the second sampling signal, and calculating a difference value of the first infrared light energy and the second infrared light energy; according to the comparison between the difference value and the preset infrared light energy, determining whether cloth exists at the corresponding position of the infrared photosensitive diode; the invention can effectively remove the interference of infrared light in the environment on the cloth detection, reduce the cloth detection time and facilitate the control of the braid length when the sewing machine cuts the thread; and through the setting of infrared photodiode, the induced light intensity that can be more accurate improves the accuracy that the cloth detected.)

1. A cloth detecting method of a sewing machine is characterized by comprising the following steps:

when an infrared emitting diode opposite to an infrared photosensitive diode in an infrared light receiving circuit is started, receiving a first sampling signal sent by the infrared light receiving circuit;

when the infrared emitting diode is closed, receiving a second sampling signal sent by the infrared light receiving circuit; the first sampling signal and the second sampling signal are sampling signals corresponding to sampling currents generated by the infrared light receiving circuit according to infrared light energy collected by the infrared photosensitive diode;

generating a first infrared light energy corresponding to the first sampling signal and a second infrared light energy corresponding to the second sampling signal, and calculating a difference value between the first infrared light energy and the second infrared light energy;

and determining whether cloth exists at the corresponding position of the infrared photosensitive diode or not according to the comparison between the difference and the preset infrared light energy.

2. The cloth detecting method of a sewing machine according to claim 1, wherein when both the first sampling signal and the second sampling signal are voltage signals, the generating of the first infrared light energy corresponding to the first sampling signal and the second infrared light energy corresponding to the second sampling signal includes:

generating a first sampling current corresponding to the first sampling signal and a second sampling current corresponding to the second sampling signal according to a preset corresponding relation between the voltage signal and the calculation current; wherein the calculated current corresponds to the sampled current, and the first sampled current and the second sampled current are both the calculated current;

and generating first infrared light energy corresponding to the first sampling current and second infrared light energy corresponding to the second sampling current according to the preset corresponding relation between the calculated current and the infrared light energy.

3. The cloth inspecting method of a sewing machine according to claim 1 or 2, characterized by further comprising:

and controlling the starting and the closing of the infrared emitting diode.

4. The cloth detecting method of a sewing machine according to claim 3, wherein the controlling of the activation of the infrared emitting diode includes:

controlling the infrared emitting diode to start according to different preset modes; when the infrared emitting diode is started according to different preset modes, the emitted infrared light has different radiation intensity.

5. The cloth detection method of a sewing machine according to claim 4, wherein the determining whether the cloth exists at the corresponding position of the infrared photodiode according to the comparison between the difference and the preset infrared light energy comprises:

according to the comparison between the difference value and the preset infrared light energy corresponding to the preset mode corresponding to the first sampling signal, determining whether cloth exists at the corresponding position of the infrared photosensitive diode; and the preset mode corresponding to the first sampling signal is a preset mode for controlling the infrared emitting diode to start when the first sampling signal is received.

6. A cloth detecting system of a sewing machine, comprising:

a single chip microcomputer for implementing the steps of the cloth detecting method of the sewing machine according to any one of claims 1 to 5 when being executed;

the infrared light receiving circuit is connected with the singlechip, is provided with an infrared photosensitive diode and is used for converting the sampling current generated by the infrared photosensitive diode into a corresponding sampling signal;

and the infrared emitting diode is arranged opposite to the infrared photosensitive diode and used for emitting infrared light to the infrared photosensitive diode when the infrared photosensitive diode is started.

7. The cloth detection system of a sewing machine according to claim 6, wherein the infrared light receiving circuit includes: the infrared photosensitive diode and the resistor;

the anode of the infrared photosensitive diode is connected with the power supply, the cathode of the infrared photosensitive diode is respectively connected with the first end of the resistor and the AD pin of the single chip microcomputer, and the second end of the resistor is grounded.

8. The cloth detection system of a sewing machine according to claim 6, wherein the infrared light receiving circuit includes: the infrared photosensitive diode and the operational amplifier circuit;

the infrared photosensitive diode is connected with the single chip microcomputer through the operational amplifier circuit.

9. The cloth detection system of a sewing machine according to any one of claims 6 to 8, characterized by further comprising:

and the infrared light emitting circuit is connected with the singlechip, is provided with the infrared emitting diode and is used for starting or closing the infrared emitting diode according to the control of the singlechip.

10. The cloth detection system of a sewing machine according to claim 9, wherein the infrared light emitting circuit is specifically configured to turn on or off the infrared emitting diode in different preset modes according to control of the single chip microcomputer; when the infrared emitting diode is started according to different preset modes, the emitted infrared light has different radiation intensity.

Technical Field

The invention relates to the technical field of sewing machines, in particular to a cloth detection method and system of a sewing machine.

Background

With the development of sewing machine technology, more and more sewing machines are moving towards automation. The sewing machine detects the state of the cloth on the sewing table through the cloth detection sensor, and performs corresponding sewing actions, such as presser foot lifting, thread cutting and the like. In general, a fabric detection sensor of a sewing machine emits infrared light through an infrared light emitting tube, and an infrared phototriode receives the infrared light to sense the fabric state.

Some sewing machines are limited by working conditions and cannot avoid the irradiation of sunlight. The infrared light in the sunlight can influence the work of the cloth detection sensor, and the cloth detection sensor can be out of order when the work is serious, so that the sewing machine generates misoperation.

Disclosure of Invention

The invention aims to provide a cloth detection method and a cloth detection system of a sewing machine, which are used for shortening the sunlight-proof processing time in cloth detection and enhancing the sunlight-proof effect.

In order to solve the above technical problem, the present invention provides a cloth detecting method of a sewing machine, comprising:

when an infrared emitting diode opposite to an infrared photosensitive diode in an infrared light receiving circuit is started, receiving a first sampling signal sent by the infrared light receiving circuit;

when the infrared emitting diode is closed, receiving a second sampling signal sent by the infrared light receiving circuit; the first sampling signal and the second sampling signal are sampling signals corresponding to sampling current generated by the infrared light receiving circuit according to infrared light energy collected by the infrared photosensitive diode;

generating a first infrared light energy corresponding to the first sampling signal and a second infrared light energy corresponding to the second sampling signal, and calculating a difference value between the first infrared light energy and the second infrared light energy;

and determining whether cloth exists at the corresponding position of the infrared photosensitive diode or not according to the comparison between the difference and the preset infrared light energy.

Optionally, when the first sampling signal and the second sampling signal are both voltage signals, the generating a first infrared light energy corresponding to the first sampling signal and a second infrared light energy corresponding to the second sampling signal includes:

generating a first sampling current corresponding to the first sampling signal and a second sampling current corresponding to the second sampling signal according to a preset corresponding relation between the voltage signal and the calculation current; wherein the calculated current corresponds to the sampled current, and the first sampled current and the second sampled current are both the calculated current;

and generating first infrared light energy corresponding to the first sampling current and second infrared light energy corresponding to the second sampling current according to the preset corresponding relation between the calculated current and the infrared light energy.

Optionally, the method further includes:

and controlling the starting and the closing of the infrared emitting diode.

Optionally, the controlling the start of the infrared emitting diode includes:

controlling the infrared emitting diode to start according to different preset modes; when the infrared emitting diode is started according to different preset modes, the emitted infrared light has different radiation intensity.

Optionally, the determining whether a cloth exists at a corresponding position of the infrared photodiode according to the comparison between the difference and the preset infrared light energy includes:

according to the comparison between the difference value and the preset infrared light energy corresponding to the preset mode corresponding to the first sampling signal, determining whether cloth exists at the corresponding position of the infrared photosensitive diode; and the preset mode corresponding to the first sampling signal is a preset mode for controlling the infrared emitting diode to start when the first sampling signal is received.

In addition, the present invention also provides a cloth detecting system of a sewing machine, comprising:

the single chip microcomputer is used for realizing the steps of the cloth detection method of the sewing machine in any one of the above steps when being executed;

the infrared light receiving circuit is connected with the singlechip, is provided with an infrared photosensitive diode and is used for converting the sampling current generated by the infrared photosensitive diode into a corresponding sampling signal;

and the infrared emitting diode is arranged opposite to the infrared photosensitive diode and used for emitting infrared light to the infrared photosensitive diode when the infrared photosensitive diode is started.

Optionally, the infrared light receiving circuit includes: the infrared photosensitive diode and the resistor;

the anode of the infrared photosensitive diode is connected with the power supply, the cathode of the infrared photosensitive diode is respectively connected with the first end of the resistor and the AD pin of the single chip microcomputer, and the second end of the resistor is grounded.

Optionally, the infrared light receiving circuit includes: the infrared photosensitive diode and the operational amplifier circuit;

the infrared photosensitive diode is connected with the single chip microcomputer through the operational amplifier circuit.

Optionally, the system further comprises:

and the infrared light emitting circuit is connected with the singlechip, is provided with the infrared emitting diode and is used for starting or closing the infrared emitting diode according to the control of the singlechip.

Optionally, the infrared light emitting circuit is specifically configured to start or close the infrared emitting diode in different preset modes according to control of the single chip microcomputer; when the infrared emitting diode is started according to different preset modes, the emitted infrared light has different radiation intensity.

The invention provides a cloth detection method of a sewing machine, which comprises the following steps: when an infrared emitting diode opposite to an infrared photosensitive diode in an infrared light receiving circuit is started, receiving a first sampling signal sent by the infrared light receiving circuit; when the infrared emitting diode is closed, receiving a second sampling signal sent by the infrared light receiving circuit; the first sampling signal and the second sampling signal are sampling signals corresponding to sampling current generated by the infrared light receiving circuit according to infrared light energy collected by the infrared photosensitive diode; generating first infrared light energy corresponding to the first sampling signal and second infrared light energy corresponding to the second sampling signal, and calculating a difference value of the first infrared light energy and the second infrared light energy; according to the comparison between the difference value and the preset infrared light energy, determining whether cloth exists at the corresponding position of the infrared photosensitive diode;

therefore, the interference of infrared light in the environment on cloth detection can be effectively eliminated, the cloth detection time is shortened, and the control of the length of the wire braid during the thread cutting of the sewing machine is facilitated; through the setting of infrared photodiode in the infrared light receiving circuit, response luminous intensity that can be more accurate improves the accuracy that the cloth detected. In addition, the invention also provides a cloth detection system of the sewing machine, and the cloth detection system also has the beneficial effects.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a flow chart of a cloth inspection method for a sewing machine according to an embodiment of the present invention;

FIG. 2 is a circuit diagram of a cloth detecting sensor of another cloth detecting method of a sewing machine according to an embodiment of the present invention;

FIG. 3 is a circuit diagram of an infrared light receiving circuit of another cloth detecting method for a sewing machine according to an embodiment of the present invention;

FIG. 4 is a schematic view showing a current driving waveform of an IR emitting diode according to another cloth inspecting method of a sewing machine according to an embodiment of the present invention;

FIG. 5 is a view showing an installation position of an infrared emitting diode and an infrared photodiode in another cloth inspecting method for a sewing machine according to an embodiment of the present invention;

fig. 6 is a structural diagram of a cloth detecting system of a sewing machine according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1, fig. 1 is a flowchart of a cloth detecting method of a sewing machine according to an embodiment of the present invention. The method can comprise the following steps:

step 101: when an infrared emitting diode opposite to an infrared photosensitive diode in the infrared light receiving circuit is started, a first sampling signal sent by the infrared light receiving circuit is received.

The first sampling signal in this step may be a sampling signal corresponding to a sampling current generated by the infrared light receiving circuit according to the infrared light energy collected by the infrared photodiode. That is, after the infrared photodiode receives the corresponding sampling current (photocurrent) generated by the infrared light energy emitted by the infrared emitting diode and the infrared energy in the environment, a processor such as a single chip in the cloth detection sensor obtains a sampling signal corresponding to the sampling current from the infrared receiving circuit.

Specifically, the specific type of the first sampling signal received by the processor may be set by a designer according to a practical scene and a user requirement, and may receive a voltage signal corresponding to a sampling current generated by the infrared photodiode, for example, when the infrared light receiving circuit is configured as the infrared light receiving circuit shown in fig. 2, the processor (single chip microcomputer MCU) may obtain a sampling voltage (first sampling signal) generated on the R7 resistor; for example, when the infrared light receiving circuit adopts the circuit structure shown in fig. 3, the processor can acquire the amplified sampling voltage generated on the R8 resistor after the infrared photodiode (D1) is connected to the operational amplifier circuit; or directly receiving the sampling current generated by the infrared photosensitive diode or the amplified sampling current. The present embodiment does not set any limit to this.

It should be noted that, in this step, after the infrared emitting diode opposite to the infrared photodiode is started, the processor obtains, through the infrared receiving circuit, a sampling signal corresponding to a sampling current generated by the infrared photodiode according to the received infrared light energy (the infrared light energy emitted by the infrared emitting diode and the infrared light energy in the environment).

It is understood that the present embodiment is illustrated by taking the primary cloth detection between the infrared photodiode and the infrared emitting diode arranged in a correlation manner as an example. For the specific mode of multiple fabric detections, the corresponding setting is performed in a manner similar to that in this embodiment, for example, when the infrared emitting diode is continuously started in multiple fabric detections, this step may be to receive a first sampling signal sent by the infrared receiving circuit at a preset time interval when the infrared emitting diode is started, where the preset time interval may be an interval time of each fabric detection set by a designer or a user; for example, when the infrared emitting diode is started at intervals in multiple cloth detections, the step may be to receive the first sampling signal sent by the infrared receiving circuit after the infrared emitting diode is started each time. The present embodiment does not set any limit to this.

Correspondingly, the control of the starting and the closing of the infrared emitting diode arranged at the opposite position of the infrared photosensitive diode can be correspondingly set by designers according to practical scenes and user requirements, for example, when the infrared emitting diode is continuously started in multiple cloth detections, the infrared emitting diode can be controlled by a user or other processors, namely, the infrared emitting diode can be connected with a switch or other processors arranged on the sewing machine; if the infrared emitting diode is started at intervals in multiple cloth detections, the infrared emitting diode can be controlled by a processor such as a single chip in the cloth detection sensor in the embodiment, that is, the infrared emitting diode can be connected with the processor in the embodiment, and the infrared emitting diode is started by the processor at preset time intervals. The present embodiment does not set any limit to this.

Preferably, in order to further improve the applicability of the cloth detection to the cloths with different thicknesses, the processor in this embodiment may control the infrared emitting diode to start up in different preset modes; when the infrared emitting diode is started according to different preset modes, the emitted infrared light has different radiation intensity. Specifically, the processor may control the infrared emitting diode to start up according to a corresponding preset mode according to cloth thickness information set by a user or sent by other processors, as shown in fig. 2, the processor (single chip microcomputer MCU) is connected to an infrared light emitting circuit formed by resistors R1, R2, R3, R4, R5, R6, a triode Q1, Q2, Q3 and an infrared emitting diode D2, and the single chip microcomputer controls the Q1, Q2 and Q3 to be turned on and off by making corresponding pins (ID0, ID1 and ID2) output high and low levels according to the cloth thickness information (thin, medium and thick). When the Q1, the Q2 and the Q3 are all conducted, the driving current of the infrared transmitter tube D2 is the maximum, and the radiation intensity of the infrared transmitter tube D2 is the strongest; when the Q1, the Q2 and the Q3 are all cut off, no driving current is applied to the infrared emission diode D2, and the infrared emission diode D2 does not emit infrared light; when one of the Q1, the Q2 and the Q3 is turned on or off or two of the Q1, the Q2 and the Q3 are turned on or off, the magnitude of the driving current on the infrared-emitting diode D2 can be adjusted, and further the radiation intensity of the infrared-emitting diode D2 can be adjusted. The specific setting of the preset mode for controlling the infrared emitting diode to start by the processor, that is, the specific structure of the infrared emitting circuit, can be set by a designer according to a practical scene and a user requirement, and this embodiment is not limited to this.

Specifically, the specific frequency and period of the driving current of the infrared emitting diode can be set by the designer, for example, as shown in fig. 4, the driving current of the infrared emitting diode (IR LED) has a frequency of 62.5KHz and a period of 16 us. The present embodiment does not set any limit to this.

Step 102: and when the infrared emitting diode is closed, receiving a second sampling signal sent by the infrared light receiving circuit.

The second sampling signal in this step may be a sampling signal corresponding to a sampling current generated by the infrared light receiving circuit according to the infrared light energy collected by the infrared photodiode. That is, after the infrared photodiode generates a corresponding sampling current (photocurrent) according to the received infrared light energy in the environment, the processor acquires a sampling signal corresponding to the sampling current from the infrared light receiving circuit.

Specifically, the specific type of the second sampling signal received by the processor may be the same as the type of the first sampling signal, which is not described in detail in this embodiment.

It should be noted that, in this step, after the infrared emitting diode opposite to the infrared photosensitive diode is turned off or before the infrared emitting diode is turned on, the processor obtains, through the infrared light receiving circuit, a sampling signal corresponding to a sampling current generated by the infrared photosensitive diode according to the received infrared light energy (infrared light energy in the environment).

It is understood that the present embodiment is illustrated by taking the primary cloth detection between the infrared photodiode and the infrared emitting diode arranged in a correlation manner as an example. The specific logic sequence of the step and the step 101 can be set by a designer, the infrared emitting diode can be started to execute the step 101, and then the infrared emitting diode is closed to execute the step; this step may be performed before the ir-emitting diode is turned on (when it is turned off), and then the ir-emitting diode is turned on to perform step 101. The present embodiment does not set any limit to this.

Correspondingly, for the condition of multiple cloth detections, for example, when the infrared emitting diode is continuously started in the multiple cloth detections, the step may be to receive the second sampling signal sent by the infrared receiving circuit before the infrared emitting diode is started; for example, when the infrared emitting diode is started at intervals in multiple cloth detections, the step may be to receive the second sampling signal sent by the infrared receiving circuit before or after the infrared emitting diode is started or turned off each time. The present embodiment does not set any limit to this.

Step 103: and generating first infrared light energy corresponding to the first sampling signal and second infrared light energy corresponding to the second sampling signal, and calculating the difference value of the first infrared light energy and the second infrared light energy.

The purpose of this step may be that the processor generates, according to the first sampling signal and the second sampling signal obtained from the infrared light receiving circuit, a first infrared light energy (an infrared light energy emitted by the infrared emitting diode and an infrared light energy in the environment) and a second infrared light energy (an infrared light energy in the environment) corresponding to each other, and calculates a difference between the first infrared light energy and the second infrared light energy (an infrared light energy emitted by the infrared emitting diode), thereby avoiding an influence of sunlight (an infrared light energy in the environment) on the cloth detection.

Specifically, for the specific manner of generating the first infrared light energy corresponding to the first sampling signal and the second infrared light energy corresponding to the second sampling signal in this step, the designer may set the first sampling signal and the second sampling signal correspondingly according to the specific type, for example, when the first sampling signal and the second sampling signal are both voltage signals, the first sampling current corresponding to the first sampling signal and the second sampling current corresponding to the second sampling signal may be generated according to the preset corresponding relationship between the voltage signals and the calculated currents; the calculation current corresponds to the sampling current, and the first sampling current and the second sampling current are both calculation currents; and generating first infrared light energy corresponding to the first sampling current and second infrared light energy corresponding to the second sampling current according to the preset corresponding relation between the calculated current and the infrared light energy. As long as the processor can generate the first infrared light energy and the second infrared light energy corresponding to the first sampling signal and the second sampling signal obtained from the infrared light receiving circuit, this embodiment does not limit this.

Correspondingly, the specific corresponding relation between the calculated current and the sampling current generated by the infrared light energy collected by the infrared photosensitive diode can be set by a designer according to a practical scene and user requirements, if the calculated current can be equal to the sampling current, the processor can calculate and generate a corresponding current value of the sampling current according to the received voltage signal; the calculated current may also have a corresponding relationship of a preset multiple or a preset increment and decrement with the sampling current, that is, the processor may calculate and generate a current value of the preset multiple or the preset increment and decrement of the corresponding sampling current according to the received voltage signal, as the calculated current. The present embodiment does not set any limit to this.

It can be understood that, in the present embodiment, after step 101 and step 102, the specific process of generating the first infrared energy corresponding to the first sampling signal and the second infrared energy corresponding to the second sampling signal in this step may generate the first infrared energy and the second infrared energy respectively; or the first infrared energy may be generated after the first performing step 101 and the second infrared energy may be generated after the second performing step 102; it is also possible to generate the second amount of infrared light after the first performed step 102 and then the first amount of infrared light after the second performed step 101. The present embodiment does not set any limit to this.

It should be noted that, for the case of multiple fabric detections, for example, when the infrared emitting diode is continuously started in multiple fabric detections, the step may be to generate the second infrared light energy corresponding to the second sampling signal, generate the corresponding first infrared light energy after receiving the first sampling signal each time, and calculate the difference between the first infrared light energy generated each time and the same second infrared light energy. If the infrared emitting diode is started at intervals in multiple cloth detections, the step may be to generate a first infrared light energy corresponding to the first sampling signal and a second infrared light energy corresponding to the second sampling signal at preset time intervals, and calculate a difference between the first infrared light energy and the second infrared light energy. The present embodiment does not set any limit to this.

Step 104: and determining whether the corresponding position of the infrared photosensitive diode has cloth or not according to the comparison of the difference value and the preset infrared light energy.

The preset infrared light energy in the step is preset infrared light energy which can determine whether a cloth exists between the infrared photosensitive diode and the infrared emitting diode which are arranged in a correlation mode, and if the difference value of the first infrared light energy and the second infrared light energy (infrared light energy emitted by the infrared emitting diode) is larger than the preset infrared light energy, it can be indicated that no cloth is blocked between the infrared photosensitive diode and the infrared emitting diode, and the cloth does not exist at the position; and if the difference value is less than or equal to the preset infrared light energy, the fact that cloth shielding exists between the infrared photosensitive diode and the infrared emitting diode can be indicated, and the cloth exists at the position is determined.

Specifically, the setting of the specific value of the preset infrared energy may be set by a designer according to a practical scene or a user requirement, which is not limited in this embodiment.

It should be noted that, when the processor in this step can control the infrared emitting diode to start according to different preset modes, this step may be to determine whether there is cloth at the corresponding position of the infrared photodiode according to the comparison between the difference and the preset infrared energy corresponding to the preset mode corresponding to the first sampling signal; the preset mode corresponding to the first sampling signal is a preset mode for controlling the infrared emitting diode to start when the first sampling signal is received. That is to say, the preset infrared light energy corresponding to each preset mode for starting the infrared emitting diode is set, so that when the infrared emitting diode is started according to different preset modes, the corresponding preset infrared light energy is used for detecting the cloth. The present embodiment does not set any limit to this.

Specifically, the specific settings of the ir emitting diode and the ir photodiode in the present embodiment on the sewing machine may be set by the designer, as shown in fig. 5, the ir emitting diode (front emitting tube, middle emitting tube, or rear emitting tube) may be installed on the upper portion of the machine head, the corresponding ir photodiode (front receiving tube, middle receiving tube, or rear receiving tube) may be set at the sewing table or the needle plate, as long as it is ensured that the ir emitting diode and the corresponding ir photodiode are set in an opposite manner, which is not limited in this embodiment.

It can be understood that, in this embodiment, for example, the processor of the single chip in the fabric detection sensor performs fabric detection between one infrared photodiode and one infrared emitting diode which are arranged in a direct-emission manner, for fabric detection of a plurality of infrared photodiodes and infrared emitting diodes which are arranged in a direct-emission manner by the processor, the fabric detection may be correspondingly arranged in a manner similar to the method provided in this embodiment, for example, the front receiving tube, the middle receiving tube, and the rear receiving tube in fig. 5 may be connected to the same processor, and the processor performs fabric detection at three positions respectively. The present embodiment does not set any limit to this.

In the embodiment, by generating the first infrared light energy corresponding to the first sampling signal and the second infrared light energy corresponding to the second sampling signal and calculating the difference value between the first infrared light energy and the second infrared light energy, the interference of infrared light in the environment on cloth detection can be effectively eliminated, the cloth detection time is reduced, and the control of the length of a wire braid during the thread cutting of the sewing machine is facilitated; through the setting of infrared photodiode in the infrared light receiving circuit, response luminous intensity that can be more accurate improves the accuracy that the cloth detected.

Referring to fig. 6, fig. 6 is a structural diagram of a cloth detecting system of a sewing machine according to an embodiment of the present invention. The system may include:

the single chip microcomputer 100 is used for implementing the steps of the cloth detection method of the sewing machine provided by the embodiment when being executed;

the infrared light receiving circuit 200 is connected with the single chip microcomputer 100 and provided with an infrared photosensitive diode 210, and is used for converting the sampling current generated by the infrared photosensitive diode 210 into a corresponding sampling signal;

and an infrared emitting diode 300 disposed opposite to the infrared photodiode 210, for emitting infrared light to the infrared photodiode 210 when activated.

Alternatively, as the infrared light receiving circuit in fig. 2, the infrared light receiving circuit 200 may include: an infrared photodiode 210(D1) and a resistor (R7);

the anode of the infrared photodiode 210 is connected to the power supply, the cathode of the infrared photodiode 210 is connected to the first end of the resistor and the AD pin of the single chip 100, and the second end of the resistor is grounded.

Optionally, the infrared light receiving circuit 200 may include: an infrared photodiode 210 and an operational amplifier circuit; wherein, the infrared photosensitive diode 210 is connected with the singlechip 100 through an operational amplifier circuit.

The specific circuit structure can be as shown in fig. 3, so that the single chip microcomputer 100 can acquire the amplified sampling voltage generated on the R8 resistor after the infrared photodiode 210(D1) is connected to the operational amplifier circuit.

Optionally, the system may further include:

and an infrared light emitting circuit of the infrared emitting diode 300 is connected to the single chip microcomputer 100, and is configured to turn on or off the infrared emitting diode 300 according to control of the single chip microcomputer 100.

Optionally, the infrared light emitting circuit may be specifically configured to start or close the infrared emitting diode 300 according to different preset modes according to control of the single chip microcomputer 100; when the infrared emitting diode 300 is started according to different preset modes, the emitted infrared light has different radiation intensity.

Specifically, as shown in fig. 2, the single chip microcomputer 100(MCU) is connected to an infrared light emitting circuit composed of resistors R1, R2, R3, R4, R5, R6, transistors Q1, Q2, Q3, and an infrared emitting diode 300(D2), and the single chip microcomputer 100 controls corresponding pins (ID0, ID1, and ID2) to output high and low levels to control on and off of Q1, Q2, and Q3. When the Q1, the Q2 and the Q3 are all turned on, the driving current of the infrared transmitter tube 300 is the maximum, and the radiation intensity of the infrared transmitter tube 300 is the strongest at the moment; when Q1, Q2 and Q3 are all turned off, no driving current is applied to the ir-emitting diode 300, and no infrared light is emitted from the ir-emitting diode 300; when one of Q1, Q2 and Q3 is turned on and off or two of Q1, Q2 and Q3 are turned on and off, the magnitude of the driving current on the ir-emitter tube 300 can be adjusted, and further the radiation intensity of the ir-emitter tube 300 can be adjusted. The specific structure of the infrared light emitting circuit can be set by a designer according to a practical scene and user requirements, and the embodiment does not limit the structure.

In the embodiment of the invention, the single chip microcomputer 100 can effectively remove the interference of infrared light in the environment on the cloth detection, reduce the cloth detection time and facilitate the control of the braid length when the sewing machine cuts the thread; through the arrangement of the infrared photosensitive diode 210 in the infrared light receiving circuit 200, the light intensity can be more accurately sensed, and the cloth detection accuracy is improved.

The embodiments are described in a progressive manner in the specification, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. For the system disclosed by the embodiment, the description is relatively simple because the system corresponds to the method disclosed by the embodiment, and the relevant points can be referred to the method part for description.

Those of skill would further appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the various illustrative components and steps have been described above generally in terms of their functionality in order to clearly illustrate this interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

The steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in Random Access Memory (RAM), memory, Read Only Memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

The present invention provides a method and a system for detecting cloth of a sewing machine. The principles and embodiments of the present invention are explained herein using specific examples, which are presented only to assist in understanding the method and its core concepts. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.