阅读说明：本技术 缝纫过程中布边控制方法 (Selvage control method in sewing process ) 是由 卢明安 管建平 黄明学 丁建明 于 2018-06-11 设计创作，主要内容包括：本发明提供一种缝纫过程中布边控制方法,其通过布料检测传感器反馈的信号值是否有明显偏差,以此来判断是否为绒毛或缺口,其判断简便且判断精准,使缝纫过程中布边控制方法的控制算法易于实现；另外该控制方法整体上更加平滑,减少逻辑判断,可靠性更高,并且由于存在平均值回归,布边调节机构速度变化平滑的同时,布边调节机构的振动更小,缝纫的线迹也更加美观。(The invention provides a selvedge control method in a sewing process, which judges whether fluff or a gap exists by judging whether a signal value fed back by a cloth detection sensor has obvious deviation or not, is simple and convenient to judge and is accurate to judge, so that a control algorithm of the selvedge control method in the sewing process is easy to realize; in addition, the control method is smoother on the whole, reduces logic judgment, has higher reliability, and has less vibration of the selvedge adjusting mechanism and more attractive sewing stitches while the speed change of the selvedge adjusting mechanism is smooth due to the existence of mean value regression.)

1. A selvedge control method in a sewing process is characterized in that a control unit executes the selvedge control method in the sewing process, and the method comprises the following steps: the control unit receives and stores a signal value representing the cloth edge distance fed back by the cloth detection sensor in real time, calculates the average value of the current signal value and the adjacent previous N signal values, calculates the deviation value of the current signal value and the average value, judges whether the deviation value is within a preset threshold range, if so, executes the step 1), and otherwise, executes the step 2);

Step 1): the control unit controls the movement of the selvedge adjusting mechanism and continues to execute the selvedge control method;

Step 2): the control unit controls the selvedge adjusting mechanism to stop acting, a delay time t is obtained according to the current cloth feeding speed and the preset identification distance of the fluff or the notch, after the control unit delays the delay time t, the signal value fed back by the cloth detection sensor is read again, the signal value is recorded as a delay signal value, the average value of the delay signal value and the previous N times of signal values is calculated, the average value is recorded as a new average value, the new deviation value of the delay signal value and the new average value is calculated again, whether the new deviation value is within the preset threshold range or not is judged, if not, the current position is judged to be the fluff or the notch, and the control unit enables the selvedge adjusting mechanism to move again and continues to execute the selvedge control method; if yes, judging that the current position is not fluff or a gap but reaches the end part of the cloth, and finishing sewing.

2. The selvedge control method in a sewing process according to claim 1, characterized in that: the specific method for controlling the movement of the selvedge adjusting mechanism by the control unit in the step 1) is as follows: the control unit calculates and obtains the running speed of a driving device in the selvedge adjusting mechanism, and outputs a control command to the driving device to enable the driving device to carry out selvedge adjustment according to the running speed.

3. The selvedge control method in a sewing process according to claim 2, characterized in that: the specific calculation method of the running speed comprises the following steps: the control unit calculates the size and the direction of the cloth edge adjusting speed reference value, and multiplies the cloth feeding speed coefficient by the cloth edge adjusting speed reference value to obtain the running speed of a driving device in the cloth edge adjusting mechanism.

4. The selvedge control method in a sewing process according to claim 3, characterized in that: the selvedge adjusting speed reference value is related to the absolute value of the average value, and when the absolute value of the average value is larger, the selvedge adjusting speed reference value output by the control unit is larger; when the absolute value of the average value is smaller, the selvedge adjusting speed reference value output by the control unit is smaller.

5. The selvedge control method in a sewing process according to claim 1, characterized in that: the method for calculating the delay time t comprises the following steps: the controller obtains the current spindle rotating speed of the sewing machine and the set needle pitch of the sewing machine, the current cloth feeding speed is obtained through calculation, and the delay time is obtained by dividing the preset identification distance of the fluff or the notch by the current cloth feeding speed.

6. The selvedge control method in a sewing process according to claim 1, characterized in that: the control unit calculates the average value by a moving average algorithm.

7. The selvedge control method in a sewing process according to claim 1, characterized in that: in the step 2), when the current position is judged to be fluff or a gap, the control unit filters a signal value returned by the cloth detection sensor when the sewing passes through the fluff or the gap, and then the cloth edge distance control method is continuously executed.

Technical Field

The invention relates to the technical field of sewing, in particular to a selvedge control method in a sewing process.

Background

In a sewing machine, in order to sew two pieces of material to be sewn (cloth) overlapped one on another in a state where their hems are kept uniform, an upper cloth control device and a lower cloth control device for moving the cloth in a direction intersecting a cloth feeding direction are generally provided on an upper surface of a needle plate.

In the sewing machine with the above functions, in order to avoid the influence of the gaps and the fluff on the sewing effect, the selvage control is realized by adopting the following methods:

As disclosed in japanese patent laid-open No. 6-121887: the device arranges cloth end detection points adopting optical fibers in a direction perpendicular to the cloth feeding direction, and detects the existence of gaps and fuzz on the cloth based on the detected change of the position of the cloth end and a preset fuzzy rule. The method requires a preset fuzzy rule, so the design of the control system is relatively complex, and in addition, the overall cost of the device is higher due to the use of the optical fiber group.

The sewing machine described in application No. 201110005846.0 includes a feed dog, an end adjusting mechanism having a cloth sensor for detecting the presence of a workpiece, and a control unit. Since the control of moving the end of the material to be sewn is not performed until the time or the feed distance for which the state is continued from the detection of the non-cloth state or the cloth-present state exceeds the predetermined width, the operation of moving the end of the material to be sewn is not performed when the detection of the notch and the naps is smaller than the length of the material to be sewn in the feed direction corresponding to the width. In the method, the realized algorithm is complex, the reliability is poor, and the control unit controls the end mechanism to rotate forwards, reversely and stop through a series of settlement and judgment. The judgment is more complicated, the possibility of erroneous judgment is also increased, and the end adjusting mechanism operates intermittently due to the discontinuity of the command, which causes a serious chattering.

Therefore, a selvedge control method is needed, which can accurately judge the gap or the fluff, and the control system and the control algorithm are simple and easy to implement.

disclosure of Invention

In view of the above-mentioned shortcomings of the prior art, the present invention provides a selvedge control method in sewing process, which is used to solve the problem in the prior art that the selvedge fluff or gap is difficult to be accurately judged.

To achieve the above and other related objects, the present invention provides a selvedge controlling method in a sewing process, in which a control unit performs a selvedge controlling method in a sewing process, including: the control unit receives and stores a signal value representing the cloth edge distance fed back by the cloth detection sensor in real time, calculates the average value of the current signal value and the adjacent previous N signal values, calculates the deviation value of the current signal value and the average value, judges whether the deviation value is within a preset threshold range, if so, executes the step 1), and otherwise, executes the step 2); step 1): the control unit controls the movement of the selvedge adjusting mechanism and continues to execute the selvedge control method; step 2): the control unit controls the selvedge adjusting mechanism to stop acting, a delay time t is obtained according to the current cloth feeding speed and the preset identification distance of the fluff or the notch, after the control unit delays the delay time t, the signal value fed back by the cloth detection sensor is read again, the signal value is recorded as a delay signal value, the average value of the delay signal value and the previous N times of signal values is calculated, the average value is recorded as a new average value, the new deviation value of the delay signal value and the new average value is calculated again, whether the new deviation value is within the preset threshold range or not is judged, if not, the current position is judged to be the fluff or the notch, and the control unit enables the selvedge adjusting mechanism to move again and continues to execute the selvedge control method; if yes, judging that the current position is not fluff or a gap but reaches the end part of the cloth, and finishing sewing.

Preferably, the specific method for controlling the movement of the selvedge adjusting mechanism by the control unit in the step 1) is as follows: the control unit calculates and obtains the running speed of a driving device in the selvedge adjusting mechanism, and outputs a control command to the driving device to enable the driving device to carry out selvedge adjustment according to the running speed.

Preferably, the specific calculation method of the operation speed is as follows: the control unit calculates the size and the direction of the cloth edge adjusting speed reference value, and multiplies the cloth feeding speed coefficient by the cloth edge adjusting speed reference value to obtain the running speed of a driving device in the cloth edge adjusting mechanism.

Preferably, the selvedge adjusting speed reference value is related to the absolute value of the average value, and when the absolute value of the average value is larger, the selvedge adjusting speed reference value output by the control unit is larger; when the absolute value of the average value is smaller, the selvedge adjusting speed reference value output by the control unit is smaller.

Preferably, the method for calculating the delay time t includes: the controller obtains the current spindle rotating speed of the sewing machine and the set needle pitch of the sewing machine, the current cloth feeding speed is obtained through calculation, and the delay time is obtained by dividing the preset identification distance of the fluff or the notch by the current cloth feeding speed.

Preferably, the control unit calculates the average value by a moving average algorithm.

Preferably, in the step 2), when the current position is judged to be a fluff or a notch, the control unit filters a signal value returned by the cloth detection sensor when the sewing passes through the position of the fluff or the notch, and then continues to execute the selvedge control method.

As mentioned above, the selvage control method in the sewing process has the following beneficial effects: whether the signal value fed back by the cloth detection sensor has obvious deviation or not is judged to be fluff or a gap, the judgment is simple and convenient, the judgment is accurate, and a control algorithm of a selvedge control method in the sewing process is easy to realize; in addition, the control method is smoother on the whole, reduces logic judgment, has higher reliability, and has less vibration of the selvedge adjusting mechanism and more attractive sewing stitches while the speed change of the selvedge adjusting mechanism is smooth due to the existence of mean value regression.

Drawings

FIG. 1 is a schematic view showing a flow of a selvage control method in a sewing process according to the present invention.

FIG. 2 is a graph showing the relationship between the curve of the edge shape of the cloth according to the present invention and the curve of the signal value fed back from the cloth detecting sensor.

Fig. 3 is a view showing an example of a sewing machine which can be used in the present invention.

Fig. 4 is a diagram of an embodiment of a control system that can be used in the present invention.

Description of the element reference numerals

1 Sewing machine

2 upper cloth aligning wheel

3 upper cloth

4 splitter plate

5 lower layer cloth

6 lower pushing device

6-1 lower push electromagnet

7 driving wheel

8. 10 leather belt

9 lower cloth aligning wheel

11 upper driving motor

12 machine needle

13 upper pushing device

14 lower driving motor

13-1 upper driving electromagnet

100 control unit

200 upper side cloth detecting sensor

300 lower side cloth detection sensor

400 operating panel

Dial with 500 needle pitches

600 spindle motor encoder

700 display panel

Detailed Description

The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure.

Please refer to fig. 1 to 4. It should be understood that the structures, ratios, sizes, and the like shown in the drawings are only used for matching the disclosure of the present disclosure, and are not used for limiting the conditions that the present disclosure can be implemented, so that the present disclosure is not limited to the technical essence, and any structural modifications, ratio changes, or size adjustments should still fall within the scope of the present disclosure without affecting the efficacy and the achievable purpose of the present disclosure. In addition, the terms "upper", "lower", "left", "right", "middle" and "one" used in the present specification are for clarity of description, and are not intended to limit the scope of the present invention, and the relative relationship between the terms and the terms is not to be construed as a scope of the present invention.

the invention provides a selvedge control method in a sewing process, wherein a control unit executes the selvedge control method in the sewing process, and the method comprises the following steps: as shown in fig. 1, the control unit receives and stores a signal value representing a cloth edge distance fed back by the cloth detection sensor in real time, calculates an average value of a current signal value and a previous N adjacent signal values, calculates a deviation value between the current signal value and the average value, and determines whether the deviation value is within a preset threshold range, if so, executes step 1), otherwise, executes step 2);

step 1): the control unit controls the movement of the selvedge adjusting mechanism and continues to execute the selvedge control method;

Step 2): the control unit controls the selvedge adjusting mechanism to stop moving, a delay time t is obtained according to the current cloth feeding speed and the preset identification distance of the fluff or the notch, after the control unit delays the delay time t, the signal value fed back by the cloth detection sensor is read again, the signal value is recorded as a delay signal value, the average value of the delay signal value and the previous N times of signal values is calculated, the average value is recorded as a new average value, the new deviation value of the delay signal value and the new average value is calculated again, whether the new deviation value is within the preset threshold range or not is judged, if not, the current position is judged to be the fluff or the notch, and the control unit enables the selvedge adjusting mechanism to move again and continues to execute the selvedge control method; if yes, judging that the current position is not fluff or a gap but reaches the end part of the cloth, and finishing sewing.

According to the invention, whether the signal value fed back by the cloth detection sensor has obvious deviation or not is judged to be fluff or a gap, the judgment is simple and convenient, and the judgment is accurate, so that the control algorithm of the selvedge control method in the sewing process is easy to realize; in addition, the control method is smoother on the whole, reduces logic judgment, has higher reliability, and has less vibration of the selvedge adjusting mechanism and more attractive sewing stitches while the speed change of the selvedge adjusting mechanism is smooth due to the existence of mean value regression.

In this embodiment, the cloth detection sensor may be used to detect the edge positions of the upper layer cloth and the lower layer cloth in real time during the sewing process, convert the edge positions into sensor signals and feed the sensor signals back to the control unit, and the control unit converts the sensor signals into return values of the cloth detection sensor (i.e., signal values representing the edge distances of the cloth) and stores the return values in the storage unit. The control unit calculates the average value of the returned values of the cloth detection sensors for the last N times through a moving average algorithm, in the embodiment, the average value of the current signal value and the adjacent previous N times signal value is calculated through the moving average algorithm, namely the average value A_t：

Wherein, F_tThe signal value fed back by the cloth detection sensor at the time t.