Electronic cam control based toothbrush bristle planting system and method

Abstract

The application discloses a toothbrush bristle implanting system and method based on electronic cam control. The toothbrush bristle implanting system comprises an XY work platform, a main shaft, a signal acquisition module and a controller. The toothbrush bristle implanting system has two control intervals in one movement cycle, which are located in a synchronous control interval and a non-synchronous control interval respectively. The main shaft performs one-time lifting reciprocating motion in the movement cycle; in the process that the main shaft moves from the start point of the synchronous control interval to the end point of the synchronous control interval, the XY work platform is driven by the main shaft motion, and in the remaining time, the XY work platform remains stationary. The application provides a reasonable speed change curve when the main shaft enters and exits the synchronous control interval, so that the main shaft speed smoothly transitions between the synchronous control interval and the non-synchronous control interval, cooperates with the electronic cam algorithm to make the moving speed of the XY work platform smoothly transition between holes, suppresses the vibration generated when the XY work platform stops, and makes the bristle implanting process more accurate and the product quality higher.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of servo motor control, and more particularly, to an electronic cam control device and method. BACKGROUND

[0002] With the continuous development of the national economy, people pay more and more attention to maintaining oral health. Having strong and white teeth is the guarantee of healthy life, so the demand for toothbrush products is also increasing. The full-automatic bristle planting machine is a mechanical and electrical integrated equipment for planting bristles on toothbrush handles, which is an important tool in the toothbrush production process. In the traditional bristle planting machine, the cooperation of the main shaft and the XY workbench adopts a mechanical cam mode, which requires a sensor to trigger the signal, which on the one hand increases the manufacturing cost of the equipment, and on the other hand may cause the control system to malfunction due to sensor damage or mechanical cam position offset.

[0003] In terms of control, the traditional bristle planting machine has a start signal for the workbench and the bristle changing mechanism to realize the function of bristle planting. When the rising edge of the start signal is detected, the control system determines the moving distance of the workbench and the bristle changing mechanism by analyzing the pattern file, then plans the motion curve of the related mechanism according to the key parameters of the speed planning, and finally drives the moving of the execution mechanism according to the speed curve. Although this method can realize speed planning of any moving distance, it cannot guarantee the execution time of the speed curve. Therefore, the user needs to set the speed planning parameters according to the main shaft speed and the maximum moving distance of the processing pattern, but in fact the main shaft speed and the maximum moving distance often change, which may cause the speed curve of the related mechanism to not match the actual working condition.

[0004] In addition, the moving speed of the running mechanism of the traditional mechanical cam bristle planting machine is stepwise, and the speed is constant during work. At the same time, in order to ensure the processing efficiency, a larger running speed is also needed. Therefore, in the high-speed and frequent start-stop mechanism of bristle planting, the use of mechanical cam will produce larger working noise and mechanical vibration, reducing the quality of bristle planting. SUMMARY

[0005] The technical problem to be solved by the present application is that the traditional bristle planting machine needs to frequently adjust the bristle planting machine speed planning related parameters due to the change of the main shaft speed and the moving distance during the bristle planting process, and a more concise and better following electronic cam control device and method is proposed.

[0006] The application provides a toothbrush bristle implanting system based on electronic cam control, which comprises an XY work platform, a main shaft, a signal acquisition module and a controller. The XY work platform is used for adjusting the position of the toothbrush, and the main shaft is used for driving the bristles to be implanted in the toothbrush to move. The signal acquisition module is used for acquiring the positions of the XY work platform and the main shaft. The controller is used for controlling the movements of the XY work platform and the main shaft.

[0007] The toothbrush bristle implanting system has two control intervals in one movement cycle, which are respectively located in a synchronous control interval and a non-synchronous control interval. The main shaft performs one-time lifting and reciprocating movement in the movement cycle; in the process that the main shaft moves from the start point of the synchronous control interval to the end point of the synchronous control interval, the XY work platform is driven by the movement of the main shaft, and in the remaining time, the XY work platform remains stationary.

[0008] When the main shaft is in the synchronous control interval, the target speed X speed of the XY work platform in the X-axis direction is controlled by an electronic cam algorithm.

[0009] Z route = Z stop -Z start (1)

[0010] Z movie = Z now -Z start (2)

[0011]

[0012] X err = X target -X now (4)

[0013]

[0014] Wherein, Z route is the total stroke of the main shaft in the synchronous control interval; Z start is the starting position of the main shaft in the synchronous control interval; Z stop is the end position of the main shaft in the synchronous control interval; Z movie is the offset distance of the main shaft relative to the starting position of the synchronous control interval; Z now is the absolute position of the main shaft; X start is the starting position of the XY work platform in the X-axis direction; X stop is the end position of the XY work platform in the X-axis direction; X target is the target position of the XY work platform in the X-axis direction at the current time; X now is the current position of the XY work platform in the X-axis direction; X erris the deviation of the target position and the current position of the XY worktable in the X-axis direction; T1 is the execution period of the electronic cam algorithm.

[0015] As a preference, the movement speed of the spindle in the non-synchronous control interval is set as V o , and the movement speed in the synchronous control interval is V t , the length of the acceleration-deceleration stage is t1, and V o < V t The function of the movement speed V of the spindle in the non-synchronous control interval with respect to time t is as follows:

[0016]

[0017] wherein, Jerk is the jerk value of the acceleration-deceleration stage, t2 is the length of the constant speed movement, and the expression of t2 is t2 = T - 2 * t1; T is the length of the spindle passing through the synchronous control interval;

[0018] The expression of the jerk value Jerk of the acceleration-deceleration stage is as follows:

[0019]

[0020] wherein, V m is the intermediate speed of the acceleration-deceleration, and the expression of V

[0021] The expression of the length T of the spindle passing through the synchronous control interval is as follows:

[0022]

[0023] wherein, S1 is the stroke of the spindle in the acceleration increasing process, and the expression of S1 is S2 is the stroke of the spindle in the acceleration decreasing process, and the expression of S2 is

[0024] As a preference, the toothbrush hair mounting system further comprises a touch screen. The touch screen is used for inputting the toothbrush version and the speed and position information of each motor in the servo motor group, and displaying the working state of each part of the system.

[0025] As a preference, the XY worktable and the spindle are driven by a servo motor group. The servo motor group comprises an X-axis motor, a Y-axis motor and a spindle motor. The XY worktable is driven by the X-axis motor and the Y-axis motor to move horizontally in two degrees of freedom; and the spindle is driven by the Z-axis motor to move vertically.

[0026] As a preference, the signal acquisition module acquires the position information of the X-axis motor, the Y-axis motor and the spindle motor through servo motor encoders to determine the positions of the XY worktable and the spindle.

[0027] The control method of the toothbrush bristle implanting system based on electronic cam control has the steps of:

[0028] Step one: obtaining the coordinates of each bristle implanting hole on the toothbrush.

[0029] Step two: importing the coordinates of each bristle implanting hole into the controller, determining the working area of the XY working platform, and setting the working path of the XY working platform; moving from the adjacent previous bristle implanting hole coordinate to the next bristle implanting hole coordinate is one bristle implanting cycle.

[0030] Step three: the main shaft starts to move, the signal acquisition module collects the position information of the main shaft and the XY working platform in real time and feeds back to the controller.

[0031] Step four: when the main shaft is in the non-synchronous control interval, the XY working platform remains stationary; when the main shaft is in the synchronous control interval, the controller obtains the target speed information of the XY working platform in the X direction through the electronic cam algorithm according to the position of the main shaft. When the main shaft reaches the end of the synchronous control interval, the XY working platform reaches the target position, so that the bristles on the main shaft are aligned with one bristle implanting hole on the workbench, the XY working platform stops moving, the bristle implanting mechanism on the main shaft completes the implanting action, and one bristle implanting cycle is completed.

[0032] Step five: repeating steps three and four until a row of bristle implanting holes on the toothbrush are completed.

[0033] The beneficial effects of the present application are:

[0034] 1、The electronic cam algorithm provided by the present application is highly related to the motion control mode of the main shaft, that is, the speed curve of the XY working platform is similar to the speed curve of the main shaft; on this basis, the present application provides a reasonable speed change curve when the main shaft enters and exits the synchronous control interval, so that the speed of the main shaft smoothly transitions between the synchronous control interval and the non-synchronous control interval, and the movement speed of the XY working platform smoothly transitions between the holes and the holes through the electronic cam algorithm, which suppresses the vibration generated when the XY working platform stops, makes the bristle implanting process more accurate, and the product quality is higher.

[0035] 2、The present application uses an electronic cam instead of a mechanical cam, which reduces the cost of the mechanical cam and the proximity switch, and avoids the failure caused by the mechanical cam bias, and improves the working stability of the entire system.

[0036] 3、The traditional control scheme needs to set corresponding speed planning parameters according to different toothbrush versions, and the control algorithm provided by the application reads the position information of each motor in each execution cycle, automatically adjusts the moving speed of the running mechanism according to the rotating speed of the main shaft and the distance between the holes, and does not need to set the speed planning parameters, which not only ensures that the speed curve of the mechanism matches the actual working condition, so that the running mechanism can smoothly and quickly reach the target position, but also can handle more version toothbrush processing work. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 is the implementation schematic diagram of the electronic cam control system of the application.

[0038] Figure 2 is the work flow chart of the embodiment of the application.

[0039] Figure 3 is the step schematic diagram of the electronic cam algorithm of the application. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical scheme and advantages of the application more clear and clear, the application will be further described in detail below in combination with the drawings and examples.

[0041] As Figure 1 shown, a toothbrush bristle planting system based on electronic cam control virtually moves the fourth axis electronic cam under the three-axis motion platform of the space rectangular coordinate system; the toothbrush bristle planting system comprises an XY work platform, a main shaft, a touch screen 11, a signal acquisition module 12, a controller 13, a servo drive module 14 and a servo motor group 15. The controller adopts an ARM processor. Under the driving of the servo motor group 15, the XY work platform moves horizontally with two degrees of freedom, and the main shaft moves vertically. The servo motor group 15 comprises an X-axis motor 16, a Y-axis motor 17 and a main shaft motor 18. The XY work platform is driven by the X-axis motor 16 and the Y-axis motor 17; the main shaft is driven by the Z-axis motor 18.

[0042] The touch screen 11 is used for inputting the toothbrush version and the speed and position information of each motor in the servo motor group 15, and displaying the working state of each part of the system. The signal acquisition module 12 is used for acquiring the position information of the X-axis motor 16, the Y-axis motor 17 and the main shaft motor 18 through the servo motor encoder, and then determining the position of the toothbrush on the XY work platform and the height of the bristles on the main shaft. The controller 11 is used for calculating the speed that the X-axis motor 16 and the Y-axis motor 17 must reach and sending a control signal to the servo drive module 14, and the drive module 14 is used for driving the X-axis motor 16 and the Y-axis motor 17 to reach the reference speed and the reference position. The controller is used for calculating the real-time speed and sending the control signal, forming an electronic cam system of the XY work platform moving with the main shaft.

[0043] The toothbrush bristle implanting system has two control intervals in one motion cycle, which are located in the synchronous control interval and the non-synchronous control interval. In the main shaft operation, the end position of the non-synchronous control interval of the last operation cycle is the starting position of the synchronous control interval of the next operation cycle. The XY work platform as a controlled object has the synchronous control interval driven by the main shaft motion and the non-synchronous control interval not driven by the main shaft motion. Among them, the synchronous control interval needs to obtain the main shaft reference position, when the main shaft reaches the starting point of the synchronous control interval, the XY axis motion platform starts to move, when the main shaft reaches the end point of the synchronous control interval, the XY work platform ends to move. The non-synchronous control interval is used for the main shaft to move from the end point of the synchronous control interval to the starting point of the next synchronous control interval.

[0044] The control method of the toothbrush bristle implanting system based on electronic cam control has the following steps:

[0045] Step S1: Obtain the coordinates of each bristle implanting hole on the toothbrush.

[0046] Step S2: Import each bristle implanting hole coordinate into the controller 11, determine the working area of the XY work platform, and set the working path of the XY work platform; moving from the previous adjacent bristle implanting hole coordinate to the next bristle implanting hole coordinate is a bristle implanting cycle, thereby obtaining the bristle implanting cycle of the system.

[0047] Step S3: Set the speed of the main shaft motor 18 and drive the main shaft to start moving. The position information of each motor is read through the encoders on the X-axis motor, the Y-axis motor and the main shaft motor, and the position information is fed back to the controller 11.

[0048] Step S4: When the main shaft is in the non-synchronous control interval, the X-axis motor 16 remains stationary; when the main shaft is in the synchronous control interval, the controller 11 obtains the target speed information of the X-axis motor 16 and the Y-axis motor 17 through the electronic cam algorithm according to the position of the main shaft motor, and sends the target speed information to the servo drive module 14. The servo drive module 14 generates corresponding pulse to drive the X-axis motor 16 and the Y-axis motor 17 according to the speed information. When the main shaft reaches the end point of the synchronous control interval, the XY work platform reaches the target position, so that the bristles on the main shaft are aligned with a bristle implanting hole on the workbench, the XY work platform stops moving, the bristle implanting mechanism on the main shaft completes the implanting action, and a bristle implanting cycle is completed.

[0049] Step S5: Repeat steps S3-S4 until a row of bristle implanting holes on the toothbrush are completed. Then, the XY work platform moves along the Y-axis direction to align the main shaft with the next row of bristle implanting holes, and the implanting operation continues.

[0050] The electronic cam algorithm in step S4 has the following specific process:

[0051] In each execution cycle T1 of the electronic cam algorithm, the controller updates the target speed X of the XY work platform in the X-axis direction according to the change of the Z-axis position parameter. speed , as follows:

[0052] Z route =Z stop -Z start (1)

[0053] Z movie =Z now -Z start (2)

[0054]

[0055] X err =X target -X now (4)

[0056]

[0057] Among them, Z start The starting position of the synchronous control section of the main axis; Z stop The end position of the synchronous control section of the main axis; Z movie The offset distance of the main axis relative to the starting position of the synchronous control zone; Z now The current absolute position of the spindle; Z route X is the total movement distance of the main axis in the synchronous control range; start It is the starting position of the XY working platform in the X-axis direction in the current hair planting cycle; stop The end position of the XY working platform in the X-axis direction; target The target position of the XY work platform in the X-axis direction at the current moment; now The current position of the XY work platform in the X-axis direction; err is the deviation between the target position and the current position of the XY work platform in the X-axis direction; T1 is the execution cycle of the electronic cam algorithm.

[0058] like Figure 3 Figure 2 shows a schematic diagram of the steps in the electronic cam algorithm of the present invention. The algorithm first obtains the spindle encoder's angle information and then determines whether the spindle is within the synchronous control range. Furthermore, based on the spindle position and its changing trend, it determines whether the spindle has passed through the start or end of the synchronous control range, as well as the direction of the pass. Different processing methods are required depending on the analysis results.

[0059] The first case: the spindle is currently running in the synchronization control interval, the running direction is from the start position to the end position of the synchronization control interval, and the distance from the end position of the synchronization control interval is greater than the preset value; first, the position of the X-axis motor is updated, then the distance between the XY worktable and the target position in the X-axis direction and the target speed X of the XY worktable in the X-axis direction are calculated according to formula (1) and formula (2) speed ; then, the controller sends the PWM wave corresponding to the target speed X speed to the X-axis motor; finally, the encoder detection value corresponding to the spindle motor is taken as the current absolute position Z of the spindle in the next execution cycle now

[0060] The second case: the spindle is currently running in the synchronization control interval, the running direction is from the end position to the start position of the synchronization control interval, and the distance from the end position of the synchronization control interval is less than or equal to the preset value, at this time it is considered that the spindle will soon pass through the end position of the synchronization control interval in the positive direction. First, the X-axis moving speed is updated, then the distance between the X-axis and the target position and the X-axis moving speed are calculated according to formula (1) and formula (2), and then the MCU is controlled to send the PWM wave with the specified number and frequency. Finally, the position of the spindle in the previous sampling period is updated to the current value of the encoder and the values of the current hole and the target hole are increased by one.

[0061] The third case: the spindle is currently running in the non-synchronization control interval, the running direction is from the start position to the end position of the synchronization control interval, and the distance from the end position of the synchronization control interval is less than or equal to the preset value, at this time it is considered that the spindle will soon pass through the end position of the synchronization control interval in the reverse direction (only when manually debugging, this case may occur). First, the hole numbers of the current hole and the target hole are reduced by one, the current position of the worktable X-axis is updated, then the distance between the X-axis and the target position and the X-axis moving speed are calculated according to formula (1) and formula (2), and then the MCU is controlled to send the PWM wave with the specified number and frequency. Finally, the value of the position of the spindle in the previous sampling period is updated to the current value of the encoder.

[0062] The fourth case: the spindle is currently running in the non-synchronization control interval and has not passed through the end position of the synchronization control interval. The position of the spindle in the previous sampling period is updated to the current value of the encoder. After the task processing is completed, the interrupt program is exited.

[0063] Next, example two is used to illustrate how to plan the speed curve of the spindle, so that the spindle speed smoothly transitions between the synchronization control interval and the non-synchronization control interval.

[0064] In the actual operation of the hair transplanting machine, it is possible to determine the speed of the spindle when it passes through the starting position and the end position of the synchronous control area, and it is also necessary to determine the total time of the spindle from the starting position to the end position of the synchronous control area. The following parameters are involved in calculating the speed curve of the spindle: the speed V of the spindle passing through the starting position and the end position of the synchronous control area o , the maximum speed of the spindle at uniform speed V t , V o and V t The intermediate speed V m , jerk, total stroke Z route When the jerk is positive (the spindle acceleration increases), the travel distance is S1; when the jerk is negative (the spindle acceleration decreases), the travel distance is S2. o Accelerate to V t The time is t1, the uniform motion time is t2, and the synchronous control time is T.

[0065] The speed V of the spindle passing through the starting position and the end position of the synchronous control area o , the maximum speed of the spindle at uniform speed V t , total stroke Z route , from V o Accelerate to V t The time t1 is a known parameter, and the rest are calculated parameters.

[0066]

[0067]

[0068]

[0069]

[0070]

[0071] t2=T-2*t1 (11)

[0072] The above formula is used to determine the jerk during the S-shaped acceleration start and the required travel distance at each stage. The speed curve is determined by the function.

[0073]

[0074] The above is a specific description of the implementation of the present invention, but the invention is not limited to the embodiments. Those skilled in the art can make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. An electronic cam control-based toothbrush bristle implanting system, comprising an XY work platform, a main shaft, a signal acquisition module (12) and a controller (13); characterized in that: The XY worktable is used to adjust the position of the toothbrush, and the main shaft is used to drive the brush hair which needs to be implanted to move; the signal acquisition module (12) acquires the position of the XY worktable and the main shaft; the controller (11) is used for the movement of the XY worktable and the main shaft; the signal acquisition module (12) obtains the position information of the X-axis motor (16), the Y-axis motor (17) and the main shaft motor (18) through the servo motor encoder, and determines the position of the XY worktable and the main shaft; The toothbrush implanting system has two control intervals in one movement cycle, which are located in the synchronous control interval and the non-synchronous control interval respectively; the main shaft performs one-time lifting reciprocating motion in the movement cycle; in the process that the main shaft moves from the start point of the synchronous control interval to the end point of the synchronous control interval, the XY worktable is driven by the main shaft motion, and in the remaining time, the XY worktable remains stationary; When the spindle is in the synchronous control interval, the target speed X of the XY worktable in the X-axis direction is controlled by an electronic cam algorithm speed As follows: Z route = Z stop - Z start (1) Z movie = Z now - Z start (2) X err = X target - X now (4) wherein, Z route is the total stroke of the spindle in the synchronization control interval; Z start is the starting position of the spindle in the synchronization control interval; Z stop is the ending position of the spindle in the synchronization control interval; Z movie is the offset distance of the spindle from the starting position of the synchronization control interval; Z now is the current absolute position of the spindle; X start is the starting position of the XY worktable in the X-axis direction movement; X stop is the ending position of the XY worktable in the X-axis direction movement; X target is the target position of the XY worktable in the X-axis direction at the current time; X now is the current position of the XY worktable in the X-axis direction; X err is the deviation of the target position and the current position of the XY worktable in the X-axis direction; T1 is the execution period of the electronic cam algorithm; The movement speed of the main shaft in the non-synchronous control interval is V o The movement speed in the synchronous control interval is V t The acceleration / deceleration phase duration t1; V o <V t The function of the movement speed V of the main shaft in the synchronous control interval with time t is as follows: Wherein, Jerk is the jerk value of the acceleration and deceleration stage; t2 is the uniform speed movement time, and its expression is t2=T-2*t1; T is the time length of the main shaft through the synchronous control interval; The expression of the jerk value Jerk of the acceleration and deceleration stage is as follows: V m is the intermediate speed of acceleration and deceleration, and its expression is The expression of the time length T of the main shaft through the synchronous control interval is as follows: Wherein, S1 is the stroke of the main shaft in the acceleration increasing process, and its expression is S2 is the stroke of the main shaft in the acceleration decreasing process, and its expression is 2. The electronic cam controlled toothbrush bristle planting system according to claim 1, wherein: The toothbrush implanting system further comprises a touch screen (11); the touch screen (11) is used for inputting the toothbrush version and the speed and position information of each motor in the servo motor group (15), and displaying the working state of each part of the system.

3. The electronic cam controlled toothbrush bristle planting system according to claim 1, wherein: The XY worktable and the main shaft are driven by the servo motor group (15); the servo motor group (15) comprises an X-axis motor (16), a Y-axis motor (17) and a main shaft motor (18); the XY worktable is driven by the X-axis motor (16) and the Y-axis motor (17) to move horizontally in two degrees of freedom; the main shaft is driven by the Z-axis motor (18) to move vertically.

4. An electronic cam-controlled toothbrush bristle implanting method, characterized by: The toothbrush implanting system as claimed in claim 1 is adopted; the toothbrush implanting method comprises the following steps: step one: obtaining the coordinates of each implanting hole on the toothbrush; Step two: importing the coordinates of each implanting hole into the controller, determining the working area of the XY worktable, and setting the working path of the XY worktable; moving from an adjacent previous implanting hole coordinate to a next implanting hole coordinate is one implanting period; Step three: the main shaft starts to move, and the signal acquisition module (12) acquires the position information of the main shaft and the XY worktable in real time and feeds back to the controller; Step four: when the main shaft is in the non-synchronous control interval, the XY worktable remains stationary; when the main shaft is in the synchronous control interval, the controller obtains the target speed information of the XY worktable in the X direction through the electronic cam algorithm according to the position of the main shaft; when the main shaft reaches the end point of the synchronous control interval, the XY worktable reaches the target position, so that the brush hair on the main shaft is aligned with one implanting hole of the toothbrush on the worktable, the XY worktable stops moving, the implanting mechanism on the main shaft completes the implanting action, and one implanting period is completed; Step five: repeating steps three and four until one row of implanting holes on the toothbrush are all implanted.

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