A control system and method for automobile wheel hub wire drawing machine

Abstract

The present invention relates to the technical field of wheel hub wire drawing machines, and specifically to a control system and method for automobile wheel hub wire drawing machines. The present invention comprises an embedded system, a motion control system part, and a multi-axis motion module. The motion control system part comprises a microprocessor chip and a motion control chip that communicate with each other. The motion control chip is connected to a distance measuring component and a tool setting component. The distance measuring component comprises a laser distance measuring sensor. The distance measuring component adopts a special acquisition mode to obtain batch measurement discrete point data, and the batch discrete point data is smoothed by a seven-point linear algorithm twice, and then combined with the chamfering data to obtain the chamfering wire drawing data, and combined with the X-axis start addition and the X-axis end addition to obtain the final execution data. The final execution data drives the multi-axis motion module to complete the wire drawing process. The method of the present invention solves many problems existing in the control system of the wire drawing machine. The smoothing algorithm of the batch discrete data ensures the accuracy of the data, and can significantly improve the wire drawing effect and production efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of wheel hub wire drawing machines, and in particular to a control system and method for an automobile wheel hub wire drawing machine. Background Art

[0002] At present, the automotive wheel hub wire drawing machines on the market have problems such as complex operation, low wire drawing precision, unstable wire drawing effect, and low production efficiency. The reasons are that in addition to problems with mechanical design and assembly, there are also many problems with the control system supporting the wire drawing machine, such as unfriendly function operation and defects in discrete data smoothing algorithms. Therefore, it is necessary to improve the existing wire drawing machine control system to improve the wire drawing effect and production efficiency. Summary of the invention

[0003] The problem to be solved by the present invention is to propose an improvement plan for the existing wire drawing machine control system.

[0004] In view of the deficiencies in the prior art, the technical solution adopted by the present invention to solve the technical problems is: a control system and method for an automobile wheel hub wire drawing machine, comprising an embedded system, a motion control system part, and a multi-axis motion module, the motion control system part comprising a microprocessor chip and a motion control chip that communicate with each other, the microprocessor chip is connected to the embedded system through the communication module, and the microprocessor chip is also connected to the tool holder assembly through the IO module and processes input signals and output signals; the motion control chip is connected to the distance measurement assembly and the tool setting assembly, and the distance measurement assembly comprises a laser distance measurement sensor; the motion control chip controls the action of the multi-axis motion module; the multi-axis motion module comprises an X-axis motor driver, a Y-axis motor driver and a frequency converter, the frequency converter drives the spindle motor to control the contour rotation, the X-axis motor driver and the Y-axis motor driver respectively drive the X-axis motor and the Y-axis motor to perform distance measurement and wire drawing movements, and the X-axis motor and the Y-axis motor are both correspondingly provided with an origin sensor and a positive limit sensor.

[0005] Preferably, the microprocessor chip model is STM32f407, and the motion control chip model is PCL6045B.

[0006] A method for controlling a control system of an automobile wheel hub wire drawing machine comprises the following steps:

[0007] Step 1: Check if the system self-checks the communication to see if it is abnormal. If it is abnormal, handle the abnormality. If it is not abnormal, proceed to the next step. Check if the communication status between the upper software of the embedded system and the motion control system is normal. Check if the connection status between the laser ranging sensor and the motion control system is normal.

[0008] Step 2: Return to the mechanical point. The X-axis and Y-axis move in the negative direction respectively until their respective origin sensors have signals. Returning to the mechanical point is completed.

[0009] Step 3: The laser distance sensor collects data, creates files manually, controls the X-axis and Y-axis positions to adjust the laser distance sensor position so that it can obtain data normally on the inside and outside of the wheel hub; the data collection method is the basic collection mode, specifically defining the collection starting point Collection end point The acquisition step p is the instruction Send it to the motion control system part, and then follow +s indicates the pause collection interval at each position. The pause collection interval ensures the stable value of the laser ranging sensor. The laser ranging sensor completes the collection process and obtains the measurement discrete points [(x0,j0),(x0,j1),...,(x n-1 ,j n-1 ),(x n ,j n )], where j represents the return value of the laser ranging sensor. The acquisition process can be divided into multiple segments (m) to obtain batch measurement discrete points. where (x'0,j'0) means [(x0,j0),(x0,j1),...,(x n-1 ,j n-1 ),(x n ,j n )];

[0010] Step 4: Multiple smoothing calculation of data. The upper software converts the data of the laser ranging sensor in the batch discrete data obtained in step 3 into Y-axis feed data, and then processes it twice with a seven-point linear smoothing algorithm to obtain smoothed wire drawing data. The smoothed wire drawing data curve is plotted next to the original data curve, and whether manual fine-tuning is required is determined based on the comparison results.

[0011] Step 5: Process the chamfering data of the outer side of the wheel hub. The upper software calculates the chamfering data according to the chamfering requirements and the chamfering parameters, and places the chamfering data at the corresponding position to generate chamfering wire drawing data. Specifically, if the acquisition direction is from the inner side to the outer side of the wheel hub, the chamfering data is added to the back end of the wire drawing data after smoothing in step 4, that is, wire drawing is performed first and then chamfering; otherwise, the chamfering data is inserted into the front end of the wire drawing data after smoothing in step 4, that is, chamfering is performed first and then wire drawing;

[0012] Step 6: Generate the final execution data. The upper program combines the chamfering and drawing data obtained in step 5 with the X-axis start addition and X-axis end addition to obtain the final execution data. The final execution data is converted into the number of walking pulses of each axis and sent to the motion control system; at the same time, the spindle rotation speed, spindle opening and closing instructions, task mode and other related parameters in this file are sent to the motion control system;

[0013] Step 7: Tool processing, tool processing includes tool setting and tool replacement. After multiple wire drawing, the tool is damaged. At this time, the tool needs to be replaced or re-set to ensure the accuracy and effect of wire drawing.

[0014] Step 8: Perform brushed chamfering or chamfer brushing.

[0015] Preferably, the laser distance sensor in step 3 performs data acquisition in a special acquisition mode. The special acquisition mode solves the problem that although the light of the laser distance sensor is on the surface of the wheel hub, it may exceed the range of the laser distance sensor and thus fail to obtain correct data. Specifically, the segmented starting point, end point, and step distance setting are different from the basic acquisition mode. The difference is that the Y-axis compensation data Y needs to be added between each segment. Δ , which means that after the first segment of acquisition is completed, the Y axis moves Y independently. Δ Then proceed with the second segment collection.

[0016] Preferably, the multiple smoothing calculation in step 4 collects the number of discrete points

[0017] [(x0,j0),(x0,j1),...,(x n-1 ,j n-1 ),(x n ,j n )] Processing conversion to Y-axis feed value

[0018] [(x0,j'0),(x0,j'1),...,(x n-1 ,j' n-1 ),(x n ,j' n )],

[0019] [(x0,j'0),(x0,j'1),...,(x n-1 ,j' n-1 ),(x n ,j' n )]=[(x0,j0-j0),(x0,j1-j0),...,(x n-1 ,j n-1 -j0),)x n ,j n -j0)],

[0020] Multiple smoothing algorithms to obtain smoothed wire drawing data

[0021] Preferably, the wire drawing data [(x0,y'0),(x0,y'1),...,(x n-1 ,y' n-1 ),(x n ,y'n )] Then combine the chamfering data to get the chamfering wire drawing data: [(x0,y'0),(x0,y'1),...,(x n-1 ,y' n-1 ),(x n ,y' n ),(x dj(1...m) ,y dj(1..m) )], chamfering wire drawing data combined with X axis start additional x s , add x at the end of the X axis e Get the final execution data: [x s ,(x0,y'0),(x0,y'1),...,(x n-1 ,y' n-1 ),(x n ,y' n ),(x dj(1...m) ,y dj(1...m) ),x e ].

[0022] Preferably, the wire drawing performed in step eight includes single wire drawing or multiple wire drawing; in single wire drawing, the operation and control system controls the X-axis to run to the wire drawing starting point and starts wire drawing, and the wire drawing process is: the spindle is turned on, a delay period is set, the X-axis moves first, and the Y-axis moves later to perform wire drawing, and chamfering is performed after the wire drawing is completed. After the chamfering is completed, the spindle stops, and the Y-axis moves to withdraw the knife and stop it in a safe position; in multiple wire drawing, the first process is the same as the single wire drawing, and after the first process is completed, the operation and control system controls the X-axis to run from the end position to the start position, and controls the Y-axis to move from the safe position to the second wire drawing start position, and the second wire drawing start position is the safe position plus the Y-axis cutting depth, and the subsequent process is the same as the first process; and the subsequent process is deduced by analogy

[0023] The beneficial effects of the present invention are as follows: the present invention proposes a new automobile wheel hub wire drawing machine control system, which integrates an advanced multi-axis motion control system. The distance measurement component adopts a special acquisition mode to solve the problem that the wheel hub surface exceeds the range of the laser distance measurement sensor, ensuring the accuracy of batch measurement of discrete point data; the batch discrete point data is smoothed twice by a seven-point linear algorithm to obtain wire drawing data, and then combined with the chamfering data to obtain chamfering wire drawing data, and the chamfering wire drawing data is combined with the X-axis starting additional x s , add x at the end of the X axis e The final execution data is obtained, and the final execution data drives the corresponding motor to move to complete the wire drawing process. The method involved in the present invention solves many problems existing in the control system of the wire drawing machine. The smoothing algorithm of batch discrete data ensures the accuracy of the data and can significantly improve the wire drawing effect and production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the system structure of the present invention;

[0025] Figure 2 is a flow chart of the method involved in the present invention;

[0026] Figure 3 It is a schematic diagram of the basic acquisition mode of the ranging component involved in the present invention;

[0027] Figure 4 It is a schematic diagram of a special acquisition mode of a distance measurement component involved in the present invention;

[0028] Figure 5 It is a schematic diagram of the cutting principle involved in the present invention. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments of the present invention are provided for the purpose of illustration and description, and are not intended to be exhaustive or to limit the present invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention, and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific uses.

[0030] As described in the background technology, the present invention improves the control system of the automobile wheel hub wire drawing machine, and the wheel hub wire drawing machine control system includes an embedded system, a motion control system part, a multi-axis motion module, a distance measurement component part, a tool holder component part and a tool setting component part. The embedded system communicates with the motion control system part, and the motion control system part controls the multi-axis motion module. The embedded system has upper software and a human-computer interaction screen, and its main functions include device parameter setting and storage; equipment operation status collection, processing, display and storage; workpiece distance measurement control and distance measurement data display; distance measurement data smoothing processing; wire drawing path issuance and operation after processing; tool holder tool change and tool setting control; manual control of each axis. The device parameters include system advanced parameter settings, system parameter settings and general parameter settings. Advanced system parameters include property parameter settings of the X-axis and Y-axis, including the use of the return to origin timeout alarm setting, enabling positive and negative hard limit settings, servo alarm level property settings, positive and negative hard limit level property settings, origin level property settings, etc.; they also include speed settings of the X-axis and Y-axis, including the running speed setting of the two axes, idle speed, reset speed, manual speed, acceleration and deceleration time, acceleration type and other settings. The system parameter settings include basic parameter settings, such as acquisition interval time, return to zero speed, acceleration and deceleration time, maximum moving speed, idle speed, processing speed, tool retraction safety distance, motor maximum speed, continuous moving distance, spindle motor start delay, acquisition speed, X-axis pulse equivalent, Y-axis pulse equivalent, hub rotation direction, etc.; it also includes tool setting parameters and processing parameter settings, such as the distance between processing point and hub, standard tool length, laser range, laser zero distance, first tool setting feed, second tool setting feed, safety tool rotation X position, safety tool rotation Y position, tool tip and laser deviation X value, tool tip and laser deviation Y value, tool setting point compensation X value, tool setting point compensation Y value, tool setting coordinate X value, tool setting coordinate Y value. General parameter settings (set for users) include X-axis point interval, X-axis point correction, X-axis end additional distance, Y-axis cutting depth, Y-axis correction range, linear speed ratio, spindle rotation speed, tool reverse execution time, tool turn waiting time, tool execution timeout time, current tool number, current processing tool number, etc. Before executing wire drawing after collecting data, it involves confirming general parameter settings, including Y-axis cutting depth, linear speed ratio, spindle rotation speed, X-axis end additional, X-axis start additional, spindle rotation direction (forward, reverse), chamfer type (chamfer, fillet), chamfer X-axis amplitude, chamfer Y-axis amplitude, fillet cutting interval, fillet cutting times, continuous task mode (single execution, continuous processing times, continuous processing feed amount), etc.

[0031] The motion control system part includes a microprocessor chip and a motion control chip that communicate with each other. The microprocessor chip connects the communication module and the IO module. The communication module is responsible for the information exchange between the embedded system and the microprocessor chip. The IO module mainly processes input information, output control and tool holder assembly control. The input information includes processing start, emergency stop, processing stop, reset, door detection, inverter alarm, automatic tool holder 1-4 sensors, tool setting sensor, tool setting overtravel sensor, X-axis origin, X-axis positive limit, Y-axis origin, Y-axis positive limit, distance measuring sensor, inverter, etc.; output information includes lighting, waiting light, running light, alarm light, inverter forward transmission, inverter reverse transmission, tool holder forward rotation, tool holder reverse rotation, air blowing, etc. The microprocessor chip is an STM32f407 chip, and the motion control chip is a PCL6045B chip; the multi-axis motion module includes an X-axis motor driver, a Y-axis motor driver and a frequency converter. The X-axis motor driver drives the X-axis motor to move, the Y-axis motor driver drives the Y-axis motor to move, and the frequency converter controls the spindle motor. The X-axis motor driver, the Y-axis motor driver and the frequency converter communicate with the microprocessor chip through the IO module to control the operation of the X-axis motor and the Y-axis motor shaft. At the same time, the IO module controls the frequency converter to drive the spindle motor to run; the communication module uses the network TCP / IP protocol to interact with the upper software for data. The X-axis motor and the Y-axis motor perform distance measurement and wire drawing, and the spindle motor controls the contour rotation. At the same time, the X-axis motor is equipped with an origin sensor and a positive limit sensor; the Y-axis motor is also equipped with an origin sensor and a positive limit sensor.

[0032] A method for controlling a control system of an automobile wheel hub wire drawing machine comprises the following steps:

[0033] Step 1: Check if the system self-checks the communication to see if it is abnormal. If it is abnormal, handle the abnormality. If it is not abnormal, proceed to the next step. Check if the communication status between the upper software of the embedded system and the motion control system is normal. Check if the connection status between the laser ranging sensor and the motion control system is normal.

[0034] Step 2: Return to the mechanical point. The X-axis and Y-axis move in the negative direction respectively until their respective origin sensors have signals. Returning to the mechanical point is completed.

[0035] Step 3: The laser ranging sensor collects data, creates files manually, controls the X-axis and Y-axis positions to adjust the laser ranging sensor position so that it can obtain data normally on the inside and outside of the wheel hub; according to the segmentation requirements and combined with the acquisition mode, set the acquisition starting position, acquisition end position, acquisition step, Y-axis compensation data, etc. of each segment; the upper software sends the data to the motion control system, and the motion control system controls the movement of the X-axis and Y-axis to complete the data acquisition process, obtain batch discrete data including the X-axis position and the corresponding laser ranging sensor position, and draw the data curve on the upper software interface;

[0036] Step 4: Multiple smoothing calculation of data. The upper software converts the data of the laser ranging sensor in the batch discrete data obtained in step 3 into Y-axis feed data, and then processes it twice with a seven-point linear smoothing algorithm to obtain smoothed wire drawing data. The smoothed wire drawing data curve is plotted next to the original data curve, and whether manual fine-tuning is required is determined based on the comparison results.

[0037] Step 5: Process the chamfering data of the outer side of the wheel hub. The upper software calculates the chamfering data according to the chamfering requirements and the chamfering parameters, and places the chamfering data at the corresponding position to generate chamfering wire drawing data. Specifically, if the acquisition direction is from the inner side to the outer side of the wheel hub, the chamfering data is added to the back end of the wire drawing data after smoothing in step 4, that is, wire drawing is performed first and then chamfering; otherwise, the chamfering data is inserted into the front end of the wire drawing data after smoothing in step 4, that is, chamfering is performed first and then wire drawing;

[0038] Step 6: Generate the final execution data. The upper program combines the chamfering and drawing data obtained in step 5 with the X-axis start addition and X-axis end addition to obtain the final execution data. The final execution data is converted into the number of walking pulses of each axis and sent to the motion control system; at the same time, the spindle rotation speed, spindle opening and closing instructions, task mode and other related parameters in this file are sent to the motion control system;

[0039] Step 7: Tool processing, tool processing includes tool setting and tool replacement. After multiple wire drawing, the tool is damaged. At this time, the tool needs to be replaced or re-set to ensure the accuracy and effect of wire drawing.

[0040] The system supports tool change and tool setting of the tool holder to improve the accuracy of the starting point of the tool tip touching the inner side of the wheel hub. The tool change process involves three parameters: tool reverse execution time, tool steering waiting time, and tool execution timeout time. The tool change function is started according to the selected tool number, and the tool holder motor is turned on for forward rotation. During the tool execution timeout, until the target tool sensor has a signal, the tool holder motor is turned off. Since the motor stops slowly, the target tool returns to the over-position. At this time, after waiting for the tool steering waiting time, the tool holder motor is turned on for reverse rotation, and the tool reverse execution time is waited. The tool holder motor is turned off, and after slow stop, it touches the target tool sensor for the second time.

[0041] Step 8: Execute wire drawing chamfering or chamfer wire drawing. During wire drawing, the motion control system performs single wire drawing or multiple wire drawing according to the task mode. In single wire drawing, the motion control system controls the X-axis to run to the wire drawing starting point and starts wire drawing. The wire drawing process is: the spindle is turned on, a delay period is made, the X-axis moves first, and the Y-axis moves later to perform wire drawing. After the wire drawing is completed, chamfering is performed. After the chamfering is completed, the spindle stops, and the Y-axis moves to withdraw the tool and stop it at a safe position. In multiple wire drawing, the first process is the same as single wire drawing. After the first process is completed, the motion control system controls the X-axis to run from the end position to the start position, and controls the Y-axis to move from the safe position to the start position of the second wire drawing. The position before the second wire drawing starts is the safe position plus the Y-axis cutting depth, and the subsequent process is the same as the first process; the subsequent process is analogous.

[0042] The laser ranging sensor in step 3 collects data in a basic collection mode or a special collection mode. The basic collection mode of the ranging component is as follows: Figure 3 As shown: the distance measuring component is installed on the X-axis, and the distance measuring component includes a laser distance measuring sensor; the X-axis is positive from the outer contour of the hub to the inner contour; after successfully returning to the mechanical zero, first, manually move the X-axis to the positive direction and move the laser distance measuring sensor to the center of the hub; secondly, manually move the X-axis to the negative direction, point the laser distance measuring sensor to the edge of the inner contour and obtain the normal value, and then record the X-axis coordinate value as the starting point of data collection. Secondly, manually move the X-axis to the negative direction, point the laser distance sensor to the edge of the outer hub contour, and obtain an abnormal value. Finally, manually move the X-axis to the positive direction, point the laser distance sensor to the edge of the outer contour and obtain a normal value. At this time, record the X-axis coordinate value as the end point of data collection. At the same time, set the distance measurement step p; collect the starting point Collection end point The acquisition step p is the instruction Send it to the motion control system part, which first calculates the number of measurement steps n That is, the distance between the collection starting point and the collection end point is divided into n segments, where n-1 segments are equidistant (p). If is an integer multiple of p, then the distance of the nth segment is p, otherwise Then follow +s indicates the pause collection interval at each position. The pause collection interval ensures the stable value of the laser ranging sensor. The laser ranging sensor completes the collection process and obtains the measurement discrete points [(x0,j0),(x0,j1),...,(x n-1 ,j n-1 ),(x n ,j n)], where j represents the return value of the laser ranging sensor. The acquisition process can be divided into multiple segments (m), and each segment needs to start from the acquisition point. Collection end point Acquisition step (p0, p1, ..., p m-1 ,p m ) is an instruction where (Δx1, Δx2, ..., Δx m-1 ,Δx m ) is the idle shift section between each acquisition. The laser ranging sensor does not collect data during the idle shift section. After the acquisition process is completed, the batch measurement discrete points are obtained. where (x'0,j'0) means [(x0,j0),(x0,j1),...,(x n-1 ,j n-1 ),(x n ,j n )], and so on. If the X-axis point is corrected x s and Y axis correction range Y j If both values ​​are greater than 0, the point correction distance needs to be added at the beginning and end of the acquisition instruction, and the acquisition step distance uses the distance of adjacent segments; take single segment acquisition as an example The calculation method of the correction segment number l is the same as n above, so the acquisition instruction is Add the correction data to get Complete the acquisition process to obtain the measured discrete points [(x s0 ,j s0 ),...,(x sl ,j sl ),(x0,j0),(x0,j1),...,(x n-1 ,j n-1 ),(x n ,j n ),(x s0 ,j s0 ),...,(x sl ,j sl )], and judge (j s0 ,...,j sl ) exceeds Y j, if it exceeds, it will be discarded; this process is to solve the problem of inaccurate processing of the start and end positions of laser acquisition by the human eye. The above situation is called the basic acquisition mode of the ranging component. This mode only requires the movement of the X-axis, and the laser ranging sensor is within the range from the acquisition start point to the acquisition end point. The special acquisition mode of the ranging component is as follows: In view of the curvature of the wheel surface and the range of the laser ranging sensor, during the movement of the X-axis, although the light of the laser ranging sensor is on the wheel surface, it may exceed the range of the laser ranging sensor and fail to obtain correct data. At this time, segmented acquisition is required. The settings of the entire segment start point, end point, and step size are the same as the basic acquisition mode. The difference is that the Y-axis compensation data Y needs to be added between each segment. Δ , which means that after the first segment of acquisition is completed, the Y axis moves Y independently. Δ Then the second segment is collected, and so on. Figure 4 Taking two-segment acquisition as an example, the acquisition instruction is After the acquisition process is completed, the batch measurement discrete points [(x'0,j'0),(x'1,j'1)] are obtained, where (x'0,j'0) represents [(x0,j0),(x0,j1),...,(x n-1 ,j n-1 ),(x n ,j n )]. If the X-axis point is corrected s and Y axis correction range Y j If both values ​​are greater than 0, the processing method is the same as the basic acquisition mode.

[0043] The multi-smoothing calculation process in step 4 is as follows: Taking a single segment as an example, the multi-segment processing method is the same as that of a single segment; the collected discrete point data [(x0, j0), (x0, j1), ..., (x n-1 ,j n-1 ),(x n ,j n )] (including X-axis position information and laser ranging sensor measurement data) is the sample data. The collected values ​​need to be processed and converted into Y-axis feed values ​​for subsequent smoothing algorithms [(x0,j'0),(x0,j'1),...,(x n-1 ,j' n-1 ),(x n ,j' n )]=[(x0,j0-j0),(x0,j1-j0),...,(x n-1 ,j n-1 -j0),(x n ,j n -j0)]. After the automatic multiple smoothing algorithm, the smoothed drawing data [(x0,y'0),(x0,y'1),...,(x n-1 ,y'n-1 ),(x n ,y' n )] and displayed on the human-computer interaction screen. After manual confirmation or fine-tuning, the fitted data is confirmed. The fitted data is combined with the chamfer data. The chamfer data is the chamfer of the outer side of the hub. The collection direction is from the inside and outside of the hub to the outside. The chamfer data is added after the smoothing data. Otherwise, it is added before the smoothing data. Here, it is added after the smoothing data to obtain the chamfering wire drawing data [(x0,y'0),(x0,y'1),...,(x n-1 ,y' n-1 ),(x n ,y' n ),(x dj(1...m) ,y dj(1..m) )], then add X at the beginning of the X axis s , add x at the end of the X axis e , get the final execution data [x s ,(x0,y'0),(x0,y'1),...,(x n-1 ,y' n-1 ),(x n ,y' n ),(x dj(1...m) ,y dj(1...m) ),x e The present invention uses two seven-point linear algorithms for smoothing. The seven-point linear smoothing process is as follows: the smoothed value is obtained by weighted averaging seven adjacent data points. The calculation formula is as follows: but

[0044] y0=j'0

[0045] y1=j'1,

[0046]

[0047] y n-2 =j' n-2 y n-1 =j' n-1 y n =j' n

[0048] The second smoothing is done the same as the first. Finally get

[0049] Due to the inaccurate data collection of the outer side of the wheel hub, the part that needs to be chamfered is not collected during data collection. This part needs to be chamfered separately. The chamfering process is divided into chamfering and rounding. The processing process is as follows: given four parameters: chamfering X amplitude, chamfering Y amplitude, rounding cutting interval m, rounding cutting times n. Among them, the chamfering X amplitude and chamfering Y amplitude determine the size of the chamfer, and the rounding cutting interval and rounding cutting times determine the processing method. The chamfering path is approximately 1 / 4 ellipse. With the help of the parametric equation of the ellipse x = acos(θ), y = bsin(θ), but because the parametric equation is based on radians, the angle must be converted into radians, θ (radians) = θ (angle) × 180 / π, and then with the help of the above parametric equation of the ellipse, the chamfering path divided into equal angles can be obtained. For example, the second point calculation, xdj2 = a cos(2*Δθ), ydj2 = b sin(2*Δθ), where Δθ represents the radian corresponding to the equally divided angle, and 2 represents the cumulative number of times. When processing chamfers, it is easy to have a large chamfer amplitude and cannot be completed in one go. Therefore, the number of rounding cuts n is introduced. The cutting principle diagram takes the number of cuts of 3 as an example. The chamfer X amplitude / the number of chamfer cuts is calculated. If there is a remainder, add 1 to get the chamfer of this processing and the distance traveled to the x-axis (for example: the chamfer X amplitude is 9, the number of cuts is 3, 9 / 3=3, which means that every time it travels 3 to x, it is cut once). The upper software sends the final execution data [xs, (x0, y'0), (x0, y'1), ..., (xn-1, y'n-1), (xn, y'n), (xdj (1...m), y'dj (1...m)), xe] and the spindle rotation data to the motion control system part, where the spindle rotation data includes the spindle opening command, spindle rotation speed, spindle closing command, etc. Drive the corresponding motor to move to complete the wire drawing process.

Claims

1. A control system for an automobile wheel hub wire drawing machine, characterized in that: It includes an embedded system, a motion control system part, and a multi-axis motion module. The motion control system part includes a microprocessor chip and a motion control chip that communicate with each other. The microprocessor chip is connected to the embedded system through the communication module. The microprocessor chip is also connected to the tool holder component through the IO module and processes input signals and output signals; the motion control chip is connected to the distance measurement component and the tool setting component, and the distance measurement component includes a laser distance measurement sensor; the motion control chip controls the action of the multi-axis motion module; the multi-axis motion module includes an X-axis motor driver, a Y-axis motor driver and a frequency converter. The frequency converter drives the spindle motor to control the contour rotation, and the X-axis motor driver and the Y-axis motor driver respectively drive the X-axis motor and the Y-axis motor to perform distance measurement and wire drawing movements. The X-axis motor and the Y-axis motor are both provided with origin sensors and positive limit sensors.

2. The control system of the automobile wheel hub wire drawing machine according to claim 1, characterized in that: The microprocessor chip model is STM32f407 and the motion control chip model is PCL6045B.

3. A method for controlling a control system of an automobile wheel hub wire drawing machine, characterized in that: The following steps are included: Step 1: Check if the system self-checks the communication to see if it is abnormal. If it is abnormal, handle the abnormality. If it is not abnormal, proceed to the next step. Check if the communication status between the upper software of the embedded system and the motion control system is normal. Check if the connection status between the laser ranging sensor and the motion control system is normal. Step 2: Return to the mechanical point. The X-axis and Y-axis move in the negative direction respectively until their respective origin sensors have signals. Returning to the mechanical point is completed. Step 3: The laser distance sensor collects data, creates files manually, controls the X-axis and Y-axis positions to adjust the laser distance sensor position so that it can obtain data normally on the inside and outside of the wheel hub; the data collection method is the basic collection mode, specifically defining the collection starting point Collection end point The acquisition step p is the instruction Send it to the motion control system part, and then follow +s indicates the pause collection interval at each position. The pause collection interval ensures the stable value of the laser ranging sensor. The laser ranging sensor completes the collection process and obtains the measurement discrete points [(x0,j0),(x0,j1),...,(x n-1 ,j n-1 ),(x n ,j n )], where j represents the return value of the laser ranging sensor. The acquisition process can be divided into multiple segments (m) to obtain batch measurement discrete points [(x'0,j'0),(x'1,j1'),...,(x' m-1 ,j' m-1 ),(x' m ,j' m )], where (x'0,j'0) means [(x0,j0),(x0,j1),...,(x n-1 ,j n-1 ),(x n ,j n )]; Step 4: Multiple smoothing calculation of data. The upper software converts the data of the laser ranging sensor in the batch discrete data obtained in step 3 into Y-axis feed data, and then processes it twice with a seven-point linear smoothing algorithm to obtain smoothed wire drawing data. The smoothed wire drawing data curve is plotted next to the original data curve, and whether manual fine-tuning is required is determined based on the comparison results. Step 5: Process the chamfering data of the outer side of the wheel hub. The upper software calculates the chamfering data according to the chamfering requirements and the chamfering parameters, and places the chamfering data at the corresponding position to generate chamfering wire drawing data. Specifically, if the acquisition direction is from the inner side to the outer side of the wheel hub, the chamfering data is added to the back end of the wire drawing data after smoothing in step 4, that is, wire drawing is performed first and then chamfering; otherwise, the chamfering data is inserted into the front end of the wire drawing data after smoothing in step 4, that is, chamfering is performed first and then wire drawing; Step 6: Generate the final execution data. The upper program combines the chamfering and drawing data obtained in step 5 with the X-axis start addition and X-axis end addition to obtain the final execution data. The final execution data is converted into the number of walking pulses of each axis and sent to the motion control system; at the same time, the spindle rotation speed, spindle opening and closing instructions, task mode and other related parameters in this file are sent to the motion control system; Step 7: Tool processing, tool processing includes tool setting and tool replacement. After multiple wire drawing, the tool is damaged. At this time, the tool needs to be replaced or re-set to ensure the accuracy and effect of wire drawing. Step 8: Perform brushed chamfering or chamfer brushing.

4. The method of controlling the automobile wheel hub wire drawing machine system according to claim 3, characterized in that: Step 3 The laser distance sensor collects data in a special collection mode. The special collection mode solves the problem that although the light of the laser distance sensor is on the wheel surface, it may exceed the range of the laser distance sensor and thus fail to obtain correct data. Specifically, the segmented starting point, end point, step distance setting and basic collection mode are different in that the Y-axis compensation data Y needs to be added between each segment. Δ , which means that after the first segment of acquisition is completed, the Y axis moves Y independently. Δ Then proceed with the second segment collection.

5. The method of controlling the automobile wheel hub wire drawing machine system according to claim 4, characterized in that: The multiple smoothing calculation in step 4 will collect the discrete points [(x0,j0),(x0,j1),...,(x n-1 ,j n-1 ),(x n ,j n )] is converted into the Y-axis feed value [(x0,j'0),(x0,j'1),...,(x n-1 ,j' n-1 ),(x n ,j' n )], [(x0,j'0),(x0,j'1),...,(x n-1 ,j' n-1 ),(x n ,j' n )]=[(x0,j0-j0),(x0,j1-j0),...,(x n-1 ,j n-1 -j0),(x n ,j n -j0)], multiple smoothing algorithms are used to obtain smoothed wire drawing data 6. The method of controlling the automobile wheel hub wire drawing machine system according to claim 5, characterized in that: The wire drawing data after smoothing in step 4 Then, the chamfering data is combined to obtain the chamfering wire drawing data: [(x0,y'0),(x0,y'1),...,(x n-1 ,y' n-1 ),(x n ,y' n ),(x dj(1...m) ,y dj(1..m) )], chamfering wire drawing data combined with X axis start additional x s , add x at the end of the X axis e Get the final execution data: [x s ,(x0,y'0),(x0,y'1),...,(x n-1 ,y' n-1 ),(x n ,y' n ),(x dj(1...m) ,y dj(1...m) ),x e ].

7. The method of controlling the automobile wheel hub wire drawing machine system according to claim 3, characterized in that: The wire drawing executed in step eight includes single wire drawing or multiple wire drawing; in single wire drawing, the operation control system controls the X-axis to run to the wire drawing starting point and starts wire drawing. The wire drawing process is: the spindle is turned on, a delay period is set, the X-axis moves first, and the Y-axis moves later to perform wire drawing. After the wire drawing is completed, chamfering is performed. After the chamfering is completed, the spindle stops, and the Y-axis moves to withdraw the tool and stop it at a safe position; in multiple wire drawing, the first process is the same as single wire drawing. After the first process is completed, the operation control system controls the X-axis to run from the end position to the start position, and controls the Y-axis to move from the safe position to the second wire drawing start position. The second wire drawing start position is the safe position plus the Y-axis cutting depth, and the subsequent process is the same as the first process; the subsequent process is analogous.

Images