CN111252558B - Contactless dip angle controllable transportation platform and control method - Google Patents

Abstract

The invention discloses a non-contact inclination controllable transport platform, comprising a first table, a second table, an upper plate of an air-floating platform and a lower plate of the air-floating platform, a pair of first supports are installed on the first table, and the first supports A first rotating shaft and a second shaft are installed on it, one end of the first rotating shaft is connected with the first motor, a first circular gear is sleeved on the first rotating shaft, the first circular gear is meshed with the first sector gear, and the first sector gear is sleeved On the second shaft, the second shaft is installed on the second support at the same time, and the second support is fixed on the second table; several position sensors are evenly installed on the side of the upper plate of the air floating platform, the first motor, the second support Both the motor and the position sensor are connected with the controller signal. By controlling the inclination of the air-floating platform, the present invention can realize rapid driving and prevent objects from slipping; the non-contact inclination-controllable air-floating transport platform is mounted on a horizontal guide rail slide or mechanical arm, which is easy to realize a wide range of objects. Contactless transport.

Description

A non-contact inclination controllable transport platform and control method

technical field

The invention relates to a non-contact inclination controllable transportation platform and a control method, and belongs to the field of non-contact transportation of light and thin objects.

Background technique

With the rapid development of the logistics transportation industry and the increasing requirements of the industrial production process, technologies such as precision manufacturing and precision transportation are gradually developing towards the requirements of high precision, high cleanliness and high reliability. The new generation of product manufacturing puts forward higher requirements for the transportation system. The traditional contact transportation positioning method as shown in Figure 1 (using belts, rollers, rubber suction cups, etc.) is easy to cause cracks and scratches on precision objects. It is also easy to cause pollution. Frictionless and non-contact transportation can effectively avoid these problems and meet the technical requirements of some special applications.

At present, there are two main methods of using pneumatic transmission technology to realize non-contact transportation, one is passive driving type, and the other is active driving type. The realization method of passive drive type is to use the principle of aerostatic bearing to form an air film between the platform and the object through the air supply of the platform under the object to achieve a non-contact state, and the air film only provides a supporting force for balancing the weight of the object. , and then use other movable platforms (slides, rollers, etc.) to provide external force to drive the movement of objects, as shown in Figure 2. The main disadvantage of passive driving is that it cannot be completely contactless, that is, the driving device is in contact with the object. The more typical devices are the Chinese patent application "air flotation equipment" (application publication number CN208037535U, application publication date: November 2, 2018), "non-contact transmission device and non-contact transmission system" (application publication number It is CN108698775A, the application publication date is: October 23, 2018), "a non-contact air flotation platform" (application publication number is CN108861590A, the application publication date is: November 23, 2018), "air suspension type" Non-contact automatic conveying device” (application publication number CN103171898A, application publication date: June 26, 2013). The implementation method of active driving is to use the oblique jet between the object and the transport device (the principle is shown in Figure 3) or the method of generating horizontal airflow traction and drag (the principle is shown in Figure 4) to drive the movement of the object. Typical devices are "an air flotation transport device" (application publication number CN104495391A, application publication date: November 7, 2014), "glass substrate non-contact air flotation transport device" (application publication number: CN108910534A, application publication date: July 5, 2018). However, although the active driving method can achieve complete contactless, its disadvantage is that the driving force provided is weak and cannot be adapted to some occasions that require rapid movement. In addition, there are problems of complex platform construction and high cost when realizing large-scale transmission in this way.

SUMMARY OF THE INVENTION

Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a non-contact inclination controllable transport platform and a control method. By controlling the inclination of the air-floating platform, rapid driving can be achieved while preventing round objects Sliding down; the non-contact inclination controllable air-floating transportation platform is mounted on the horizontal rail slide table or mechanical arm, and it is easy to realize the large-scale non-contact transportation of round objects.

Technical solution: In order to solve the above technical problems, the non-contact inclination controllable transportation platform of the present invention includes a first table, a second table, an upper plate of the air-floating platform and a lower plate of the air-floating platform, and a pair of first table is installed on the first table. Support, a first rotating shaft and a second shaft are installed on the first support, one end of the first rotating shaft is connected with the first motor, a first circular gear is sleeved on the first rotating shaft, and the first circular gear meshes with the first sector gear , the first sector gear is sleeved on the second shaft, the second shaft is simultaneously installed on the second support, the second support is fixed on the second table; a pair of third supports are installed on the second table, and are installed on the third support There are a third rotating shaft and a fourth shaft, one end of the third rotating shaft is connected with the second motor, a second circular gear is sleeved on the third rotating shaft, the second circular gear is meshed with the second sector gear, and the second sector gear is sleeved on the first gear. On the four shafts, the fourth shaft is simultaneously installed on the fourth support, and the fourth support is fixed on the lower board of the air flotation platform; the upper board of the air flotation platform is provided with a plurality of through holes, and the through holes are on the upper board of the air flotation platform Symmetrical distribution, the aperture of the through hole in the center of the upper plate of the air flotation platform is the smallest, and the closer to the edge of the upper plate of the air flotation platform, the larger the aperture, and several position sensors are evenly installed on the side of the upper plate of the air flotation platform. The side of the upper board is also provided with air guide holes, and the lower board of the air flotation platform is provided with grooves and sealing grooves, which are used to form a cavity after the two boards are connected; the first motor, the second motor and the position sensor are all connected with the control signal connection.

Preferably, the diameter of the through hole is 0.5mm˜2mm.

Preferably, the through holes of equal diameter are at the same distance from the central hole.

A control method of the above-mentioned non-contact inclination controllable transport platform, comprising the following steps:

Step (1), set the initial parameters, the main parameters include: judging whether the critical displacement γ of the inclination angle needs to be controlled; the characteristic size (radius or diameter) of the circular object; the reading cycle of the position sensor signal; the transmission of the motor control signal cycle;

Step (2) The controller continuously collects the data of the position sensor for three periods;

Step (3), the controller reads the data of each position sensor, the controller captures the actual position of the circular object through any three position sensors located on the X and Y axes, and sends the position information to the controller;

Step (4), read the value of each position sensor, and determine the maximum displacement △Xmax of the circular object relative to the air floating platform;

Go to step (5), determine whether the maximum displacement change value is less than the critical value, if so, there is no need to control the rotation of the air flotation platform, the air flotation platform itself can realize the movement of the circular object centering trend with the air flotation platform, and go to step (7); No, go to step (6),

Step (6) Determine the two sub-maximum displacements △Xsubmax of the circular object relative to the air floating platform, locate the center position of the circular circular object according to the three-point coordinates, and determine the circular object in the X and Y directions. The amount of movement (Δx and Δy), the direction of movement (±X direction or ±Y direction), and the relative velocity and acceleration a of the circular object are obtained from Gsinθ _x = ma, which gives θ _x , which is determined by θ _y =θ _x Δy/Δx θ _y size, the controller controls the rotation direction and rotation angle of the first motor and the second motor;

Step (7), repeat step (3) until the round object is transported to the designated position.

Beneficial effect: Compared with the prior art, the present invention has the following advantages:

1) By opening radially distributed air outlet holes on the surface of the air flotation platform, the diameter of which increases in the radial direction, the circular object can be suspended in the middle of the air flotation platform under the condition of slight disturbance.

2) By controlling the rotation inclination of the air floating platform, the tilt control of the suspended circular object can be realized, and the oblique component of gravity is used as the driving force to obtain a large motion acceleration, so that the circular object can follow the platform below to move horizontally .

3) By installing a position sensor on the side of the air flotation platform to detect the position change of the circular object, as a feedback input controller to control the inclination of the platform, the precise control of the movement state of the circular object can be achieved.

Description of drawings

Figure 1 is a schematic diagram of the working situation of the contact roller conveying device;

Figure 2 is a schematic diagram of the working situation of a passively driven contactless transport device;

Figure 3 is a schematic diagram of the working principle of the oblique jet active-driven transport device;

Figure 4 is a schematic diagram of the working principle of the horizontal airflow traction towing active drive transport device;

Fig. 5 is the working principle schematic diagram of the present invention;

Fig. 6 is the oblique side view of the mechanical part of the non-contact inclination controllable transport platform;

Figure 7 is a front view of the mechanical part of the non-contact inclination controllable transport platform;

Figure 8 is a top view of the mechanical part of the non-contact inclination controllable transport platform;

Figure 9 is a top view of the air flotation platform;

Fig. 10 is the A-A sectional view of Fig. 9;

Figure 11 is an exploded view of the whole device;

Figure 12 is the control principle diagram of the non-contact inclination controllable transport platform;

Fig. 13 is the program flow chart of the control method of the non-contact inclination controllable transport platform;

FIG. 14 is a schematic diagram of the application of the non-contact inclination controllable transport platform mounted on the two-dimensional sliding table.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

As shown in FIGS. 1 to 14 , the non-contact inclination controllable transport platform of the present invention includes a first table 9 , a second table 13 , an upper deck 1 of an air flotation platform, and a lower deck 3 of the air flotation platform. A pair of first supports are installed, a first shaft and a second shaft 12 are installed on the first supports, one end of the first shaft is connected to the first motor 10 through a coupling 11, and a first circle is sleeved on the first shaft. Gear 8, the first circular gear 8 meshes with the first sector gear 7, the first sector gear 7 is sleeved on the second shaft 12, the second shaft 12 is simultaneously installed on the second support, and the second support is fixed on the second table 13 A pair of third supports are installed on the second table 13, a third shaft and a fourth shaft are installed on the third supports, one end of the third shaft is connected with the second motor, and a second circle is sleeved on the third shaft Gear, the second circular gear meshes with the second sector gear, the second sector gear is sleeved on the fourth shaft, the fourth shaft is simultaneously installed on the fourth support, and the fourth support is fixed on the lower plate 3 of the air-floating platform. The bearing 6 is installed on the corresponding support; the upper plate 1 of the air flotation platform is provided with a plurality of through holes, the through holes are symmetrically distributed on the upper plate 1 of the air flotation platform, and the diameter of the through holes is 0.5mm~ 2mm, the distance between the through holes of equal diameter and the center hole is the same, the hole diameter of the through hole in the center of the upper plate 1 of the air flotation platform is the smallest, and the closer to the edge of the upper plate 1 of the air flotation platform, the larger the hole diameter, and the diameter of the through hole in the upper plate 1 of the air flotation platform is larger. Several position sensors 2 are evenly installed on the side, and there are air guide holes on the side of the upper board 1 of the air flotation platform. The lower board 3 of the air flotation platform is provided with grooves and sealing grooves to form a cavity after the two boards are connected. , the upper board 1 of the air flotation platform and the lower board 3 of the air flotation platform are sealed by the sealing ring 5, and the two boards are connected by screws 14; the first motor 10, the second motor and the position sensor 2 are all connected with the controller signal . The position sensor 2 is a non-contact (infrared, laser, etc.) sensor, which detects the 3-point position of the edge of the circular object, and then calculates the center of the circular object to obtain the position information of the circular object.

A control method of the above-mentioned non-contact inclination controllable transport platform, comprising the following steps:

Step (1), set the initial parameters, the air flotation platform needs to establish x-axis and y-axis, and control the motor to rotate around these two axes to drive the air flotation platform. In addition, the main set parameters also include: the critical displacement γ for judging whether to control the inclination angle; the characteristic size (radius or diameter) of the circular object; the reading cycle of the position sensor signal; the transmission cycle of the motor control signal; the center of the circular object The theoretical trajectory of the motion;

Step (2) The controller continuously collects the data of the position sensor for three cycles, and the controller starts to control from the data of the fourth cycle, which improves the accuracy of the acceleration solution, that is, the control accuracy is improved;

Step (3), the controller reads the data of each position sensor, the controller captures the actual position of the circular object through any three position sensors located on the X and Y axes, and sends the position information to the controller;

Step (4), read the value of each position sensor 2, and determine the maximum displacement △Xmax of the circular object relative to the air floating platform, where △Xmax is the maximum value of the difference between two adjacent data;

Go to step (5), determine whether the maximum displacement change value is less than the critical value, if so, there is no need to control the rotation of the air flotation platform, the air flotation platform itself can realize the movement of the circular object centering trend with the air flotation platform, and go to step (7); No, go to step (6),

Step (6) Determine the two sub-maximum displacements △Xsubmax of the circular object relative to the air floating platform, locate the center position of the circular circular object according to the three-point coordinates, and determine the circular object in the X and Y directions. Movement amount (Δx and Δy), movement direction (±X direction or ±Y direction) (±X or ±Y is the deviation direction of the circular object relative to the air floating platform, and this method is used to determine the rotation direction of the motor. For example : When the circular object has a deviation in the ±X direction relative to the air floating platform, the motor should be controlled to make the air floating platform rotate around the Y axis. When the circular object has a deviation in the ±Y direction relative to the air floating platform, the motor should be controlled to make the air The floating platform rotates around the X-axis) and the relative velocity and acceleration a of the circular object. From Gsinθ _x = ma, θ _x is obtained, the size of θ _y is determined by θ _y =θ _x Δy/Δx, and the first motor 10 is controlled by the controller and the rotation direction and rotation angle of the second motor, θ _x is the desired angle of the first motor, θ _y is the desired angle of the second motor, Δx and Δy are the amount of movement of the circular object in the X and Y directions, and two After tilting, control the motor to rotate to the desired angle; the initial angles of the two desired angles are both zero degrees, and the desired angle refers to the value relative to the initial angle. Since the initial angle is zero degrees, the desired angle is the calculated angle.

Step (7), repeat step (3) until the round object is transported to the designated position.

As shown in Figure 5, which is a schematic diagram of the working principle of the device of the present invention, the circular object is initially suspended in the center of the surface of the air flotation platform. The center is offset from the center of the air flotation platform. Due to the large aperture on the outside of the surface of the air flotation platform and the large air flow out of the outside hole, when the circular object moves to the outside to cover the large-diameter air hole, the circular object is unevenly affected by the air pressure, causing the circular object to tilt slightly and return to the center. The design scheme of gradually increasing the outer aperture can ensure that the circular object can still be automatically centered when it is subjected to minor disturbances. When the air-floating platform is driven below to move rapidly, the circular object deviates from the center of the air-floating platform and approaches the edge of the air-floating platform, and the position sensor 2 detects the position change of the circular object and feeds this signal back to the controller (the controller can be an industrial computer, PLC, single-chip microcomputer, etc.), control the motor to drive the air-floating platform to generate inclination, and the degree of inclination is determined by the feedback signal of the position sensor 2. After the circular object tilts with the air-floating platform, its gravity component can provide the driving force to ensure that the circular object can follow the driving air-floating platform below to move.

As shown in Figures 6 to 8, the non-contact inclination controllable transport platform device mainly includes an upper plate 1 of an air flotation platform, a position sensor 2, a lower plate 3 of the air flotation platform, an air intake joint 4, and a driving air The floating platform produces an inclined air-floating platform. The air flotation platform consists of two upper and lower layers with the same structure, namely the upper air flotation platform and the lower air flotation platform, which are used to realize two rotational degrees of freedom. The lower air floating platform is driven by the first motor 10 to drive the first circular gear 8 to drive the first sector gear 7 to drive the first table 9 to rotate. In the transport platform device, the position sensor 2 is installed on the side of the upper deck 1 of the air-floating platform. The air source is connected with the air inlet joint 4 through the connecting hose, the signal output port of the position sensor 2 is connected with the input conversion module, the input conversion module is connected with the data acquisition module, and the data acquisition module is connected with the controller. The input conversion module is a signal conditioning circuit, which can transmit the analog current and voltage signals output by the position sensor 2 to the data acquisition module. The data acquisition module is an A/D conversion circuit, which is used to convert the analog signal output by the position sensor 2 into a digital signal. The controller can be an industrial computer, or a single-chip computer or a programmable controller. According to the set control algorithm, the final drive motor realizes the change of the inclination of the air floating platform.

As shown in Figure 9 and Figure 10, the surface of the upper plate 1 of the air flotation platform is a smooth plane, and there are radially symmetrical ventilation holes (1-1), and the diameter of the air holes gradually increases from the inside of the platform to the outside, and the diameter range is 0.5mm ~2mm. There are threaded holes on the side of the upper plate 1 of the air flotation platform for connecting the position sensor 2 . In FIG. 10 , the lower board 3 of the air flotation platform is connected with the upper board 1 of the air flotation platform, and the two are sealed by a sealing ring. The lower plate 3 of the air flotation platform has a groove cavity inside, and the outer side is provided with a threaded hole to communicate with the groove cavity.

In Figure 11, the air-floating platform is composed of upper and lower layers with the same structure. The lower air-floating platform is rotated by the first motor 10 to drive the shaft. The table top 9 rotates.

As shown in Figure 12, by reading the signal of the position sensor 2, the maximum displacement △Xmax is obtained. If the maximum displacement is less than γ, it indicates that the circular object can remain stable under the action of the automatic centering trend of the air floating platform; if the maximum displacement is less than γ If the displacement is greater than γ, it indicates that the air-floating platform needs to be tilted by controlling the air-floating platform. At this time, at least two sub-maximum displacements ΔXsubmax are obtained by reading the signal of the position sensor 2, and the center position of the circular object is located according to the three-point coordinates, thereby determining the movement of the circular object in the X and Y directions. amount (Δx and Δy), direction of movement (±X direction or ±Y direction), and relative velocity and acceleration of circular objects. The two-axis rotation direction of the air-floating platform is determined by the moving direction of the circular object, and the x-axis rotation inclination is determined by the relative acceleration of the circular object. The method to determine the rotational inclination of the x-axis is that the gravity component it can generate should be equal to the force that causes the acceleration of the circular object. By analyzing the force relationship of the inclined circular object, that is, Gsinθ _x = ma, the x-axis can be obtained. Rotate the inclination angle θ _x , and then determine the y-axis rotation inclination angle θ _y according to the proportional relationship between the inclination angle and the displacement increment θ _y =θ _x Δy/Δx, and drive the motor to control according to the rotation direction and angle of the shaft.

Figure 13 shows the flow chart of the control program of the non-contact inclination controllable transport platform. The program starts. After completing the parameter and state initialization settings, go to step 2. Position sensors 2 such as infrared and grating capture the actual position of the circular object and transmit it to the control system through the data acquisition module. Go to step 3, and determine the maximum displacement △Xmax of the circular object relative to the air floating platform. Go to step 4, judge whether the maximum displacement change value is less than the critical value, if so, go to step 5, without controlling the rotation of the air flotation platform, go to step 6, the air flotation platform itself can realize the movement of the circular object centering trend with the air flotation platform; If no, go to step 7, determine the 2 sub-maximum positions △Xsubmax of the circular object relative to the air floating platform, go to steps 8 and 9, calculate the trajectory trend of the circular object relative to the air floating platform and calculate the circle from the three-point positioning The relative velocity of the shaped object. Go to step 10 and step 11, respectively calculate the rotation direction of the air flotation platform from the trajectory trend obtained in step 8, and calculate the rotation angle of the air flotation platform according to the gravity component of the circular object from the relative air flotation platform speed obtained in step 9. Then enter step 12, control the motor to drive the air floating platform to move. In step 13, it is judged whether the circular object is synchronized with the platform according to the data of the position sensor 2, if not, return to step 2 to repeat the above process; if so, keep the current pose state of the platform.

Figure 14 is a schematic diagram of an application case where a non-contact inclination controllable transport platform is mounted above a two-dimensional horizontal slide. By controlling the inclination of the air-floating platform, it can ensure that the circular objects move with the air-floating platform, so as to realize the complete non-contact and large-scale transportation of the circular objects.

The above is only the preferred embodiment of the present invention, it should be pointed out that: for those skilled in the art, without departing from the principle of the present invention, several improvements and modifications can also be made, and these improvements and modifications are also It should be regarded as the protection scope of the present invention.

Claims (3)

1. a non-contact inclination controllable transport platform is characterized in that: comprise the first table, the second table and the upper deck of the air-floating platform and the lower deck of the air-floating platform, a pair of first supports are installed on the first deck, and a pair of first supports are installed on the first deck. A first rotating shaft and a second shaft are installed on a support, one end of the first rotating shaft is connected with the first motor, a first circular gear is sleeved on the first rotating shaft, the first circular gear meshes with the first sector gear, and the first sector The gear is sleeved on the second shaft, the second shaft is simultaneously installed on the second support, and the second support is fixed on the second table; a pair of third supports are installed on the second table, and a third rotating shaft is installed on the third support and the fourth shaft, one end of the third shaft is connected with the second motor, a second circular gear is sleeved on the third shaft, the second circular gear is meshed with the second sector gear, and the second sector gear is sleeved on the fourth shaft, The fourth shaft is simultaneously installed on the fourth support, and the fourth support is fixed on the lower board of the air flotation platform; the upper board of the air flotation platform is provided with a plurality of through holes, and the through holes are symmetrically distributed on the upper board of the air flotation platform, The diameter of the through hole in the center of the upper plate of the air flotation platform is the smallest, and the closer to the edge of the upper plate of the air flotation platform, the larger the hole diameter. Several position sensors are evenly installed on the side of the upper plate of the air flotation platform. There is also an air guide hole, the lower plate of the air flotation platform is provided with a groove and a sealing groove, and a cavity is formed after the upper plate of the air flotation platform and the lower plate of the air flotation platform are connected; the first motor, the second motor and the position sensor are all Connect to the controller signal. 2 . The non-contact inclination controllable transport platform according to claim 1 , wherein the diameter of the through hole is 0.5 mm to 2 mm. 3 . 3 . The non-contact inclination controllable transport platform according to claim 1 , wherein the distances between the through holes of equal diameter and the central hole are equal. 4 .

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