A kind of non-contacted conveyance and locating platform device and control method
Technical field
The present invention relates to non-contacted conveyance and locating platform device and control method, belong to non-contacted conveyance and the field of locating technology of semi-conductor silicon chip.
Background technology
A new generation's silicon chip manufacture requirements its must adopt without the non-contacting mode that rubs to guarantee surface cleaning not damaged producing in transmitting procedure.How realizing transporting safely with location of extremely brittle very thin silicon chip is a very important manufacture mounting technology, is to ensure that key one ring of production efficiency and yields.Traditional contact location mode (adopting the way of contact such as roller, sucker) easily causes surface of semiconductor workpiece and scratch, crackle occurs, there is also the problems such as electrostatic and metallic pollution simultaneously, cannot adapt to the demand of current technological development.Alignment system is proposed the requirement of high accuracy, high-cleanness and high reliability by a new generation's silicon chip manufacture, has great advantage without the non-contacting mode that rubs meeting these technology requesting party masks.
Contactless the transporting with location mode of current popular is to adopt Bernoulli Jacob or flux vacuum cup to implement absorption crawl above silicon chip.But, the mode of this kind of crawl easilys lead to absorption affinity instability in moving process, there is the hidden danger such as wafer is easy to fall off, it is necessary to carrying out spacing by alignment pin or rubber blanket to it, otherwise workpiece very easily occurs sideslip to come off.Separately have and a kind of utilize aerostatic bearing to realize the mode of contactless transmission and location, it is carried out below supply from object by aperture or porous restriction element, between object and device, forming a layer of air pressure film thus reaching to reduce the effect of surface contact, being successfully applied at present on glass substrate production line.Above two air supporting mode has in common that workpiece upper and lower surface pressure differential only plays the effect of balancing gravity, and the movement that workpiece is in the horizontal direction still has to rely on Mechanical Contact to realize.Strictly speaking, this and unrealized truly entirely without contact.As it is shown in figure 1, the air film between device 4 and workpiece 2 only plays a supportive role, workpiece 2 is transported by motor driving rolls 1, owing to contacting with roller 1, and workpiece 2 easy scratch, deformation or damage.As in figure 2 it is shown, utilize Bernoulli vacuum sucker 1 that semiconductor workpiece 3 is captured, workpiece 3 and alignment pin 2 are in contact condition, and otherwise workpiece is susceptible to sideslip and comes off.Additionally, this kind of working method also needs to otherwise designed drives the moveable platform of workpiece motion s, such as mechanical arm, slide unit etc., the existence of guide rail movement parts is added significantly to the weight of integral platform, is also highly vulnerable to breakage the cleannes of working environment.
In existing this suspension transmission equipment, it is comparatively typical that just like Chinese patent application " a kind of air suspension device ", (application publication number is CN201961843U, Shen Qing Publication day is: on JIUYUE 7th, 2011), " air suspension conveyer " (application publication number is CN102363476A, Shen Qing Publication day is: on February 29th, 2012), " float-up device and conveyer device " (application publication number is CN1966371B, Shen Qing Publication day is: on August 15th, 2012), " Non-touch grasping tool " (application publication number is CN102107782A, Shen Qing Publication day is: on June 29th, 2011), " vortex type adult and contact-free transport device " (application publication number is CN102083720A, Shen Qing Publication day is: on June 1st, 2011).
In the prior art, also have a contactless transfer ways of class air supporting, as it is shown on figure 3, offer oblique nozzle 2 on device 1 surface, below workpiece 3, spraying windstream by oblique nozzle 2, utilizing the viscosity draw that air flows thus driving workpiece 2 to move.Although utilizing oblique jet flow can realize object is driven, but, there are the following problems for this technical scheme:
1) air flow rate of nozzle injection is less, and driving force is limited, and workpiece motion s acceleration is little;2) there is horizontal component and vertical component in oblique air-flow, and wherein vertical component easily causes the appearance of workpiece instability disturbing phenomenon;3) easily produce electrostatic when contacting with semiconductor workpiece from the high velocity air of nozzle injection to pollute, near contact point, be easily caused stress simultaneously concentrate.4. nozzle air current direction is limited, is unfavorable for workpiece is carried out motor control.
In the prior art, also has a kind of device " a kind of air supporting feeding device " (application publication number is 201410626307.2) utilizing air-flow viscous force driving workpiece to do contactless motion, although which is capable of contactless transport, but it is the absence of the pose detection of object and controls function, cannot realize object is accurately positioned, it is significantly increased additionally, driver element adopts the mode of all supply to also lead to air consumption.
Summary of the invention
Goal of the invention: in order to overcome the deficiencies in the prior art, the present invention provides a kind of non-contacted conveyance and locating platform device, can farthest utilize air-flow viscous force drive workpiece motion s, it is thus achieved that bigger acceleration of motion, it is achieved truly entirely without contact.
Technical scheme: for solving above-mentioned technical problem, a kind of non-contacted conveyance of the present invention and locating platform device, including shipping platform, it is positioned at the fixed platform below shipping platform and is positioned at the pedestal below fixed platform, described fixed platform is supported by fixed platform and is connected with pedestal, described shipping platform is provided with several grooves, each groove is provided with air inlet and venthole, described air inlet is connected with air induction hose, air induction hose is connected with malleation source of the gas, described venthole is connected with air-out hose, and air-out hose is connected with negative pressure source of the gas.
As preferably, described malleation source of the gas is connected with malleation air relief valve by connecting flexible pipe, the outfan of malleation air relief valve is connected by the air induction hose of effusion meter, the outfan of effusion meter is connected by the air induction hose of valve seat cylinder manifold and passes through valve seat cylinder manifold and the connection of the first air-operated solenoid valve group, and the first air-operated solenoid valve group is connected with air inlet by flexible pipe.
As preferably, described shipping platform is arranged over high-speed camera, and high-speed camera is connected with input modular converter, and input modular converter is connected with controller, and controller drives module to be connected with output, and output drives module to be connected with air-operated solenoid valve group.
As preferably, described negative pressure source of the gas is vacuum pump, it is connected with negative pressure air relief valve by connecting flexible pipe, the outlet of negative pressure air relief valve is connected with the air-out hose of effusion meter, the entrance of effusion meter is connected with the air-out hose of cylinder manifold, air-out hose is connected with air-operated solenoid valve group, and air-operated solenoid valve is connected with venthole by flexible pipe, and air-operated solenoid valve drives module to be connected with output.
As preferably, described shipping platform is connected with fixed platform by leveling nut.
A kind of above-mentioned non-contacted conveyance and the control method of locating platform device, comprise the following steps:
1) controller obtains the current actual positions of object by high-speed camera shooting shipping platform;
2) coordinate system of the current actual positions substitution control system of the object obtained according to step 1 detects whether to need to change desired motion track, as just, entrance step 3, as negative, entered step 4;
3) reset desired motion track according to mission requirements, desired motion track is carried out trajectory planning and track shaping, enter step 4;
4) obtain the reference state amount of current point in time, calculate ohject displacement deviation e (t) according to reference state amount and virtual condition gauge;
5) offset deviation amount e (t) is as inputting in incoming controller, PID controller calculate controlled quentity controlled variableThe Proportional coefficient K of PID controller in equationP, integration time constant TI, derivative time constant TDPreset to meet system requirements by trial and error procedure;
6) driving the work of electromagnetic valve group according to controlled quentity controlled variable u (t) by output module, object moves under the effect of air stream drives power;
7) detect whether to arrive target location, as being no, then continue to repeat step 1-6;If it has, then enter step 8;
8) detect whether to need to preserve data, if it is, enter step 9, as being no, enter step 10;
9) writing data such as stating the virtual condition amount of real-time sampling, reference state amount and controlled quentity controlled variable to file, file preserves after terminating, and enters step 10;
10) transport task to terminate, stop.
In the present invention, described in transport platform and comprise a ganoid flat board, multiple chase units that planar surface is symmetric, mutually separated by planar surface between each groove.The groove of planar surface can be circular, square, Back Word type or cross, and depth of groove is generally less than 200 microns.Offer air inlet and venthole in inside grooves in pairs, the planar bottom surface residing for air inlet and venthole offers screw thread, be used for connecting gas joint and supply.Air inlet supply normal pressure, venthole supplying negative voltage power.The air inlet of each groove is all connected with source of the gas malleation and negative pressure separately through a two-bit triplet solenoid directional control valve with venthole, can change airflow direction in groove by valve is controlled.
In the present invention, the electromagnetic valve in air-operated solenoid valve group is two-bit triplet electromagnetic valve, and one end of two-position three-way valve is connected with source of the gas malleation, and one end is connected with source of the gas negative pressure, realizes the switching of malleation and negative pressure by controlling electromagnetic valve.Passage is connected by trachea with electromagnetic valve, and compression air inlet flexible pipe is connected with source of the gas malleation and negative pressure by solenoid directional control valve with compression air exhaust flexible pipe.
In the present invention, input modular converter is high-speed camera phase control device or image pick-up card, image information can be converted to positional information and be transferred to controller.During according to image pick-up card, it is necessary to program to obtain the positional information of object by OpenCV.
Described output drives module to be circuit amplification board, it is possible to isolate numeral output card or multichannel non-isolated TTL output card for multichannel, drives electromagnetic valve action for controller signals is amplified output.
Described controller is industrial computer, single-chip microcomputer or Programmable Logic Controller, and its function has: good man machine interface is mutual, and the kinestate of object controls and display, data preservation etc..
When providing the displacement of targets and expected path that transport object, utilize high-speed camera to sample, the physical location of object is substituted in the coordinate system of control system;The expected pose track of object being carried out trajectory planning, obtains with reference to pose track, the design for controller provides reference state amount.The deviation value with target location can be obtained in the position of system coordinate system by object, deduct with attained pose and obtain error state amount e (t) with reference to pose;Pass through PID control systemComputing obtain the controlled quentity controlled variable u (t) of air-operated solenoid valve group, drive electromagnetic valve action by exporting amplification module;For different objects, pid control parameter presets to meet the requirement of system rapidity, Stability and veracity by trial and error procedure.
In the present invention, will be located in the electromagnetic valve Unified coding of same column, switch positive/negative-pressure source of the gas with row or driver element number for basic transformation unit.So can realize the combination in any of row or different driving unit, and different positive/negative-pressure source of the gas combinations can produce different viscous drive power, the impact of object moving state is also different such that it is able to make object reach acceleration, the even static kinestate that slows down meets the requirement that system transports and positions.During original state, all electromagnetic valves are all turned on passing into compression air and form air cushion, make object keep constant suspension;Behind input object target position, high speed camera sensor can obtain object current location and carry out feedback and obtain error amount compared with moving target, PID controller it is also rounded by the controlled quentity controlled variable u that calculates.With row for basic transformation unit be controlled time, controlled quentity controlled variable u and electromagnetic valve group corresponding corresponding regular.When u is 0, all electromagnetic valves are turned on malleation, and now object is not driven power effect;U be+1 to+4 change time, object be subject to below 1 row to 4 row unit in viscosity air stream drives will move right, i.e. u is more big, and driver element columns is more many, and driving force is also more big.On the contrary, u be-1 to-4 change time, object be subject to below 1 row to 4 row unit in viscosity air stream drives will to left movement.Columns or the driver element number of described controlled quentity controlled variable integer and valve are corresponding relations.
Beneficial effect: the non-contacted conveyance of the present invention and locating platform device and control method, has the advantage that
1. owing to air is bottom horizontal flow sheet state in groove, therefore, air-flow viscous force can be farthest utilized to drive workpiece motion s, obtain bigger acceleration of motion, this can realize truly entirely without contact, it is not likely to produce electrostatic when air-flow contacts with semiconductor workpiece to pollute, is not easily caused stress near contact point and concentrates.
2. air-flotation type has cleanliness without any pollution, does not generate heat, the not advantage such as magnetisation, and pneumatic system is easier to maintain, and builds simple.It is absent from guide rail movement parts, significantly reduces the weight of integral platform, also greatly improve the cleannes of working environment.
3. air inlet and steam vent adopt the mode of independent gas supply, and control mode is flexible.Driver element and support unit are arranged and are easily achieved, it is possible to achieve high-precision contactless transport workpiece, meet the requirement of semiconductor element transmission.It is strong which has driving force, and control performance is excellent, is not easily introduced the advantages such as disturbance.
4. design PID controller based on many valves co-ordination principle, solve that systematic parameter is uncertain, model is excessively complicated and control performance is affected problem by interference, semi-conductor silicon chip is suppressed to transport and the generation of unstable vibration phenomenon in position fixing process, thus the high accuracy realizing kinestate controls.
Accompanying drawing explanation
Fig. 1 is the schematic diagram of one of existing air supporting feeding device operative scenario;
Fig. 2 is the schematic diagram of the two of existing air supporting feeding device operative scenario;
Fig. 3 is the schematic diagram of the three of existing air supporting feeding device operative scenario;
Fig. 4 is the structural representation of the present invention;
Fig. 5 is the axonometric drawing of mechanical part of the present invention;
Fig. 6 is the front view of mechanical part of the present invention;
Fig. 7 is the top view of mechanical part of the present invention;
Fig. 8 is the left view of mechanical part of the present invention;
Fig. 9 is the object transportation state schematic diagram of the present invention;
Figure 10 is the partial sectional view of mechanical part of the present invention;
Figure 11 is using row as the controlled quentity controlled variable input mode figure of basic transformation unit;
Figure 12 is using driver element number as the controlled quentity controlled variable input mode figure of basic transformation unit;
The contactless air supporting of Figure 13 transports the program flow diagram transporting PID control method of parametric controller.
Detailed description of the invention
As shown in Fig. 4 to Figure 10, in the non-contacted conveyance of the present invention and locating platform device, transporting platform 2 and be supported in above fixed platform 4 by leveling nut 3, leveling nut 3 scalable transports platform 2 levelness;Fixed platform 4 supports 15 with pedestal 8 by threaded fixed platform and is rigidly connected, forming a space installing air-operated solenoid valve group 7 and pipeline, air-operated solenoid valve group 7, effusion meter 6a, 6b, valve seat cylinder manifold 9a, 9b, air relief valve 5a, 5b are arranged on pedestal 8.
Described malleation source of the gas is connected with malleation air relief valve 5a by connecting flexible pipe 15a, the outfan of malleation air relief valve 5a is connected by the air induction hose 14a of effusion meter, and the outfan of effusion meter 6a is connected by the air induction hose 13a of valve seat cylinder manifold 9a and is passed through valve seat cylinder manifold 9b and is connected with air-operated solenoid valve group 7;Negative pressure source of the gas is vacuum pump, is connected with negative pressure air relief valve 5b by connecting flexible pipe 15b, and the outlet of air relief valve 5b is connected with the air-out hose 14b of effusion meter 6b, and the entrance of effusion meter 6b is connected with the air-out hose 13b of cylinder manifold.
The port that controls of described air-operated solenoid valve group 7 electrically connects with the output port of output modular converter 10, the input port of output modular converter 10 is connected with the output port of controller 11, the transmission port of high-speed camera 1 is connected with the input port of input modular converter 12, and the output port of input modular converter 12 is connected with the input port of controller 11.
The electric control part that described contactless air supporting transports parametric controller is divided and is included output conversion module 10, controller 11, input conversion module 12.Output conversion module 10 is made up of multi-channel digital output card and interlock circuit, for the controlled quentity controlled variable of conveying gas moving electromagnetic valve group.Input conversion module 12 is formed the collection for ohject displacement by high-speed camera and supporting processor thereof.Controller 11 is industrial computer, single-chip microcomputer or Programmable Logic Controller.Transport and control the Bit andits control of the system ohject displacement according to Real-time Collection with locating platform, substitute into and coordinate system obtains error amount, according to certain control requirement and control algolithm, the control variable of output air-operated solenoid valve group, thus changing direction and the size of gas viscosity power in driver element, finally realize the control to ohject displacement.
Shown in Fig. 9 and Figure 10 it is one to comprise 36 air supportings with mutually isostructural groove driver element and transport and positioning device structure schematic diagram and partial sectional view thereof.With reference to Figure 10, planar surface offers the square indentations 1-1 being symmetric, and the groove 1-1 length of side is 13 millimeters, the degree of depth 200 microns.Offering air inlet 1-2 and venthole 1-3 inside groove 1-1 in pairs, diameter is 2 millimeters, air inlet 1-2 and offer screw thread in the planar bottom surface residing for venthole 1-3, for connecting with air induction hose and exhaust hose.Air inlet 1-2 supplies normal pressure, venthole 1-3 supplying negative voltage power.Mutually separated by guide rail surface 1-4 between each groove 1-1.If apparatus surface is placed with workpiece 20, when compressing air and inputting from air inlet 1-2 and 1-5, the runner formed due to groove 1-1 bottom surface and workpiece 20 lower surface is wider, flow resistance is little, overwhelming majority air is just discharged from venthole 1-3 and 1-6, a small amount of air is flowed in the gap that workpiece 20 and planar surface are constituted, and forms a layer of air pressure film, makes workpiece 20 that any contact not occur with platform surface.When air flows from air inlet 1-2 to gas outlet 1-3 in groove 1-1, its quasi-viscous effect can make workpiece 20, and forces are applied, so that workpiece 20 moves.Each air inlet is connected with source of the gas malleation and negative pressure each through two-bit triplet electromagnetic valve with venthole.The air-flow viscous force direction in each chase unit can be changed by controlling the break-make of electromagnetic valve, make workpiece 20 move towards certain direction.
Figure 11 show using row as basic transformation unit be controlled time, the rule of correspondence of controlled quentity controlled variable u and electromagnetic valve group.When u is 0, all electromagnetic valves are turned on malleation, and now object is not driven power effect;U be+1 to+4 change time, object be subject to below 1 row to 4 row unit in viscosity air stream drives will move right, i.e. u is more big, and driver element columns is more many, and driving force is also more big.In figure, solid black round dot represents and passes into negative pressure, hollow for malleation.On the contrary, u be-1 to-4 change time, object be subject to below 1 row to 4 row unit in viscosity air stream drives will to left movement.
It also it is the rule of correspondence of controlled quentity controlled variable u and electromagnetic valve group shown in Figure 12.It and Figure 11 are the difference is that being controlled using driver element number as basic transformation unit.When u is 0, all electromagnetic valves are turned on malleation, and now object is not driven power effect;When u is+1 to+8 change, driver element number is more many, and driving force is also more big.On the contrary, when u is-1 to-8 change, the number of unit of reverse drive is more many.
As shown in figure 13, the control method of a kind of non-contacted conveyance and locating platform device, comprise the following steps:
1 controller obtains the current actual positions of object by high-speed camera shooting shipping platform;
The coordinate system of the current actual positions substitution control system of 2 objects obtained according to step 1 detects whether to need to change desired motion track, as just, entrance step 3, as negative, entered step 4;
3 reset desired motion track according to mission requirements, and desired motion track carries out trajectory planning and track shaping, enter step 4;
The 4 reference state amounts obtaining current point in time, calculate ohject displacement deviation e (t) according to reference state amount and virtual condition gauge;
5 offset deviations amount e (t), as inputting in incoming controller, are calculated controlled quentity controlled variable by PID controllerThe Proportional coefficient K of PID controller in equationP, integration time constant TI, derivative time constant TDPreset to meet system requirements by trial and error procedure;
6 drive the work of electromagnetic valve group according to controlled quentity controlled variable u (t) by output module, and object moves under the effect of air stream drives power;
7 detect whether to arrive target location, as being no, then continue to repeat step 1-6;If it has, then enter step 8;
8 detect whether to need to preserve data, if it is, enter step 9, as being no, enter step 10;
9 write, to file, data such as stating the virtual condition amount of real-time sampling, reference state amount and controlled quentity controlled variable, and file preserves after terminating, and enters step 10;
10 transport task terminates, and stops.
The above is only the preferred embodiment of the present invention; it is noted that, for those skilled in the art; under the premise without departing from the principles of the invention, it is also possible to make some improvements and modifications, these improvements and modifications also should be regarded as protection scope of the present invention.