CN102629122B - Large-stroke high-speed dual-drive nano positioning system - Google Patents

Abstract

The invention discloses a nano-positioning system with large-stroke and high-speed dual-drive. The nano-positioning system includes a motion trajectory instruction system (101), a main control computer (102), a PMAC motion control board (103), and a servo motion control system (104). ), a positioning platform and a measurement control system (107), wherein the positioning platform includes a macro-motion stage (105) and a micro-motion stage (106), and this nano-positioning system considers three-axis measurement and three-axis control, and can control X, Y _1. Y ₂ is precisely controlled. The positioning platform adopts the motion mode of "long-stroke linear motor + short-stroke planar motor". Feedback, complete small-scale high-precision motion, long-stroke linear motor as the slave control system of short-range motor, use grating ruler to measure feedback, complete long-stroke high-speed coarse motion. The response speed and real-time performance of the system are greatly improved by decoupling the motion of the planar motor and introducing the PMAC motion control board.

Description

A nanopositioning system with large stroke and high speed dual drive

technical field

The invention relates to the technical field of special equipment for microelectronics, in particular to a large-stroke, high-speed, dual-drive nano-positioning system, which is especially suitable for the workpiece stage subsystem of a step-and-scan projection lithography machine.

Background technique

The nano-positioning system with large stroke, high speed and high precision occupies an extremely important position in the field of modern cutting-edge industrial manufacturing and scientific research. With the rapid development of integrated circuit (Integrated circuit) manufacturing, biochip technology, high-precision CNC machining technology and high-speed scanning detection, higher requirements are put forward for the stroke, speed, acceleration and accuracy of the positioning system. The research of precision positioning system is also imminent. IC manufacturing is a typical application field of high-speed and high-precision positioning systems. It is a strategic industry for national economic and social development. It plays an important role in promoting economic development, social progress, improving people's living standards, and ensuring national security. The focus of current international competition and an important symbol to measure the degree of modernization and comprehensive national strength of a country or region.

However, for the ultra-precise nano-positioning system, the positioning accuracy of the system is contradictory to the improvement of the operating speed. The increase of operating speed and acceleration increases the inertial force of the mechanism, and the frequency of inertial force changes also increases. The system is prone to elastic deformation and vibration, which not only destroys the movement accuracy of the mechanism, but also increases the establishment time of mechanical stability. The operation and positioning accuracy of the system are reduced. High-precision positioning requires smooth operation of the mechanism, while high productivity requires the system to reciprocate at high speed and start and stop at high speed. At the same time, the sensor that feeds back position information in the control system is also an important link that limits the improvement of positioning accuracy and movement speed. For example, the resolution of a precision grating ruler used as a displacement sensor can reach the nanometer level, but due to the limitation of the scanning frequency of the signal detection circuit, the maximum allowable moving speed of the grating ruler is inversely proportional to its measurement resolution. On the other hand, the large stroke and high precision of the positioning system are also contradictory. At present, the accuracy of large-stroke driving and transmission methods (precision screw drive, linear motor, voice coil motor, etc.) is generally limited to the micron level; the positioning accuracy of the driver represented by piezoelectric ceramics reaches the nanometer level, but the stroke can only reach the micron level. tens of microns. How to solve these contradictions well and realize a large-travel, high-speed, high-precision positioning system has become an urgent problem to be solved in the current microelectronics industry.

Contents of the invention

The purpose of the present invention is to overcome the above-mentioned shortcoming of prior art, propose a kind of nano-positioning system with double drive of large stroke, high speed, high precision.

In order to solve the above technical problems, the present invention provides a large-stroke high-speed dual-drive nano-positioning system, said nano-positioning system includes a motion trajectory command system, a main control computer, a PMAC motion control board, a servo motion control system, a positioning platform and The measurement control system, wherein the positioning platform includes a macro-motion stage and a micro-motion stage, the macro-motion stage completes high-speed motion, performs rough positioning, and solves the speed problem of the entire nanopositioning system, and then the micro-motion stage completes precise micro-motion Positioning, the nano-positioning system first uses the motion trajectory command system to plan the trajectory of the positioning platform, and then uses the motion trajectory command system to input the trajectory planning command into the main control computer, and the main control computer sends the trajectory planning command to the PMAC motion control board through the PEWIN interface The PMAC motion control board controls the positioning platform to achieve mobile positioning according to the set parameters and trajectory planning instructions. At the same time, the measurement control system continuously detects the actual positions of the macro-motion stage and micro-motion stage of the positioning platform, and transmits the detection signals in real time. For the PMAC motion control board, the PMAC motion control board undergoes sampling processing, error calculation and error compensation, and feeds back to the servo motion control system in real time, so as to ensure the fast tracking response speed and nano-level motion accuracy of the positioning platform.

The positioning platform described in the present invention includes: a macro-motion stage and a micro-motion stage, wherein the macro-motion stage is driven by a long-stroke linear motor to realize long-stroke and high-speed motion, and the micro-motion stage is driven by a short-stroke planar motor to realize high-precision fine-tuning ; The long stroke is composed of a permanent magnet linear motor in the X direction and the Y direction, the Y direction motor stator is mechanically connected with the X direction motor mover, and a linear grating scale is used to form a closed-loop feedback control; the short stroke horizontal movement is controlled by Lorentz The planar motor is used for control, and the Lorenz motor is composed of three magnetic motors. The stator coil is mechanically connected to the Y-direction linear motor mover, and a 3-axis laser interferometer is used for position detection to form a closed-loop feedback control.

Among them, the motion decoupling of the planar motor is carried out, because the position command sent by the main control computer to the positioning platform is the set position of the precision workpiece table in the (x _CG , y _CG , θ _CGz ) direction during the system positioning, and the precision workpiece The output of the table drive motor is the position of one x-direction and two y-direction motors, so before controlling the precision workpiece table, it is necessary to perform coordinate conversion on the drive motor to ensure the efficiency of control and improve the control accuracy of the system and response speed.

The control of the positioning platform described in the present invention adopts master-slave control, the short-stroke motor is the main control object, and the laser interferometer is used to measure and feedback to complete small-scale high-precision motion. The long-range motor is used as the slave control system of the short-range motor, and the linear grating scale Measuring feedback to complete long-stroke high-speed coarse motion. The relative position of the tracking movement between long and short strokes is detected by a linear grating scale. When the linear grating scale detects that the workpiece table moves within a set distance from the target position, usually a few microns, such as 1-9 microns, the long-distance motor stops. Movement, switch to short-range motor movement until the micro-motion table reaches the target position, and always try to keep the relative position of the two from zero to ensure high tracking motion accuracy and fast tracking response speed.

Among them, the laser interferometer adopts a three-axis measurement system, which can precisely measure the x, y ₁ and y ₂ of the micro-motion stage; the linear grating scale can precisely measure the X and Y directions of the coarse motion stage, forming a closed-loop feedback; The nano-positioning system is designed with three-axis measurement and three-axis control in mind, and can control x, y ₁ , y ₂ to overcome the error caused by the torsion of the positioning platform.

Principle of the present invention is:

A large-stroke, high-speed, high-precision macro-micro dual-drive nano-positioning system, which includes a motion trajectory command system, a main control computer, a PMAC motion control board, a servo motion control system, and a positioning platform (macro motion stage and micro motion stage) and measurement control system. The nano-positioning system is designed with three-axis measurement and three-axis control in mind, and can control x, y ₁ , y ₂ to overcome the error caused by the torsion of the positioning platform. In terms of mechanical structure, the combined structure of macro-motion stage and micro-motion stage is adopted, that is, the macro-motion stage completes the high-speed movement, performs rough positioning, and solves the speed problem of the entire system; then the micro-motion stage completes precise positioning, so that both Make the positioning system achieve extremely high positioning accuracy and response speed, and the control is reliable. The specific operation process is: the positioning system first performs trajectory planning on the positioning platform, and inputs the trajectory planning instructions into the main control computer, and the main control computer sends the trajectory planning instructions to the PMAC control board through the PEWIN interface, and the PMAC control board follows the set parameters and Trajectory planning instructions are used to control the positioning platform to realize mobile positioning. At the same time, the measurement system continuously detects the actual position of the positioning platform, and transmits the detection signal to the PMAC control card in real time. After sampling processing, error calculation, and error compensation, the PMAC control card gives real-time feedback to the The servo control system ensures the fast tracking response speed and nanometer-level motion accuracy of the positioning platform. The measurement system of the present invention includes: a laser interferometer, a linear grating ruler, a displacement sensor, a speed sensor and the like. Among them, the laser interferometer adopts a three-axis measurement system, which can precisely measure the x, y ₁ and y ₂ of the micro-motion stage; the linear grating scale can precisely measure the X and Y directions of the coarse motion stage, forming a closed-loop feedback; the speed sensor The speed of the positioning platform can be precisely measured to realize speed feedback.

The advantage of the present invention compared with prior art is:

The present invention adopts long-stroke linear motor micron-level coarse motion plus short-stroke Lorentz motor nano-level fine-tuning structure, and by introducing a PMAC motion control card with a high-performance DSP chip as the core and decoupling the motion of the planar motor, the positioning system can be adjusted Perform high-speed, high real-time multi-axis control, thereby effectively improving the response speed and positioning accuracy of the positioning system.

Description of drawings

Fig. 1 is a basic schematic diagram of the present invention;

Fig. 2 is a schematic diagram of a three-axis measurement system;

Fig. 3 is a schematic diagram of a multi-loop control block diagram of a servo control system;

Fig. 4 is a schematic diagram of position coordinate decoupling;

Figure 5(a) and Figure 5(b) are schematic diagrams of the decoupling steps of position coordinates.

Detailed ways

The structural principle and working principle of the present invention will be further described in detail below in conjunction with the accompanying drawings.

Fig. 1 is a basic schematic diagram of the present invention, as shown in Fig. 1, a kind of large-stroke high-speed dual-drive nano-positioning system mainly includes motion trajectory command system 101, main control computer 102, PMAC motion control board 103, servo motion control system 104. Positioning platform and measurement control system 107. The positioning platform includes a macro motion stage 105 and a micro motion stage 106 . First, the motion trajectory of the positioning platform (macro-motion stage 105 and micro-motion stage 106) is provided to the main control computer 102 by the motion trajectory instruction system 101, and the main control computer 102 sends the trajectory planning instruction to the PMAC motion control board 103 through the PEWIN interface , the PMAC motion control board 103 controls the macro-motion stage 105 and the micro-motion stage 106 in the positioning platform to realize precise motion and positioning according to the set parameters and trajectory planning instructions, and the measurement control system 107 continuously detects the position of the positioning platform. The actual positions of the macro-motion stage 105 and the micro-motion stage 106 are transmitted to the PMAC motion control board 103 in real time, and the PMAC motion control board 103 is fed back to the servo motion control system 104 in real time after sampling processing, error calculation, and error compensation , so as to ensure the fast tracking response speed of the positioning plane and the motion accuracy of nanometer level.

As shown in Figure 2, it is a laser interferometer three-axis measurement system. The nanopositioning system is designed with three-axis measurement and three-axis control in mind, and can accurately measure the x, _y1 , and _y2 directions of the micro-motion stage (106). control.

As shown in Figure 3, it is a multi-loop control block diagram of the servo control system, which mainly includes a position command 301, a position loop controller 302, a speed loop controller 303, a PWM power amplifier 304, a driving motor 305, a positioning platform 306, and a position feedforward Controller 307 , current feedback 308 , speed feedback 309 , position feedback 310 . The multi-loop control block diagram of the servo system is a traditional three-loop control, that is, a position loop, a speed loop and an acceleration loop, which belongs to the prior art. Since the workbench must not only have high positioning accuracy and motion accuracy, but also have high speed and acceleration, increasing the acceleration will easily cause vibration. Moreover, in order to ensure the high-precision operation of the positioning platform, the support of the workbench generally adopts balanced air bearing components, and the air bearing support components are likely to cause low-frequency oscillations. Based on the above reasons, the workbench adopts the traditional three-loop control strategy, namely position loop, velocity loop and acceleration loop, so that the system can not only suppress vibration, but also have good tracking characteristics. In the three-loop control, the position sensor uses a dual-frequency laser interferometer, and the speed and acceleration feedback in the speed loop and acceleration loop can be estimated by using the speed sensor, acceleration sensor, or the detected displacement. In addition, a position feed-forward compensator is also introduced to compensate the errors caused by damping and inertia, and on this basis, filter technology is used to further suppress the mechanical resonance of the system.

As shown in Figures 4 and 5, when the positioning system is working, the position command sent by the main control computer to the positioning platform is the set position of the x, y, and θ _z directions of the micro-motion table, and the output of the micro-motion table drive motor is It is the position of one x-direction motor and two y-direction motors, so before controlling the micro-motion table, it is necessary to perform position coordinate transformation on its driving motor. Position coordinate transformation refers to the input command position (x _CG , y _CG , θ _CGz ) for coordinate transformation, transforming into direct position input (x, y ₁ , y ₂ ) of the three motors.

As shown in Figure 4, S1 is the distance between the center of gravity of the _y1 motor and the center of mass of the micro-motion table on the x-axis, S2 is the distance between the center of gravity of the _y2 motor and the center of mass of the micro-motion table on the x-axis, and S3 is the center of gravity of the x-motor and the center of mass of the micro-motion table The distances on the y-axis, S1, S2 and S3 are all constant.

As shown in Figure 5, in order to obtain the relationship between the input command position (x _CG , y _CG , θ _CGz ) and the motor input position (x, y ₁ , y ₂ ), the position command can be completed in two steps, Translate the position of the center of mass of the micro-motion stage to the command position (x _CG , y _CG ), and then rotate the micro-motion stage around the z-axis by θ _CGz .

When the center of mass position of the micro-motion table is translated to the command position (x _CG , y _CG ), the relationship between the motor position (x′, y ₁ ′, y ₂ ′) and the command position (x _CG , y _CG , θ _CGz ) for:

$\left\{\begin{array}{c}{\mathrm{<span\; class="notranslate">\; x</span>}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; CG</span>}}\\ {{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; CG</span>}}\\ {{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; CG</span>}}\end{array}\right.$

After the micro-motion stage is rotated by θ _CGz , the position of the x motor is:

x=x'-S3*sinθ _CGz

Since the y ₁ and y ₂ motors are symmetrical about the x motor, the positions of the y ₁ and y ₂ motors are:

$\left\{\begin{array}{c}{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>{{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; *</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; cos</span>}{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; CGz</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; sin</span>}{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; CGz</span>}}\\ {\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span>{{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; *</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; cos</span>}{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; CGz</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; sin</span>}{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; CGz</span>}}\end{array}\right.$

Combining the above formula, we can get,

$\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; CG</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; sin</span>}{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; CGz</span>}}\\ {\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; CG</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; *</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; cos</span>}{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; CGz</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; sin</span>}\\ {\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; CG</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; *</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; cos</span>}{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; CGz</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; sin</span>}{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; CGz</span>}}\end{array},{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; CGz</span>}}\right.$

The above transformation can be obtained,

$\left\{\begin{array}{c}{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; CG</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; -</span>\frac{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 3</span>}}{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>\\ {\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; CG</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; *</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; *</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; *</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; cos</span>}{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; z</span>}}<span\; class="notranslate">\; )</span>\\ {\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; CGz</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; arcsin</span>}\frac{{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}\end{array}\right.$

When θ _CGz is small, the relationship between the motor position (x, y ₁ , y ₂ ) and the command position (x _CG , y _CG , θ _CGz ), that is, the forward position coordinate conversion expression is:

$\left[\begin{array}{c}\mathrm{<span\; class="notranslate">\; x</span>}\\ {\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\\ {\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}\end{array}\right]<span\; class="notranslate">\; =</span>\left[\begin{array}{ccc}\mathrm{<span\; class="notranslate">\; 1</span>}& \mathrm{<span\; class="notranslate">\; 0</span>}& <span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 3</span>}\\ \mathrm{<span\; class="notranslate">\; 0</span>}& \mathrm{<span\; class="notranslate">\; 1</span>}& \mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}\\ \mathrm{<span\; class="notranslate">\; 0</span>}& \mathrm{<span\; class="notranslate">\; 1</span>}& <span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 2</span>}\end{array}\right]\left[\begin{array}{c}{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; CG</span>}}\\ {\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; CG</span>}}\\ {\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; CGz</span>}}\end{array}\right]$

Transformed from the above formula, the reverse position coordinate conversion expression of the driving motor can be obtained as:

$\left[\begin{array}{c}{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; CG</span>}}\\ {\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; CG</span>}}\\ {\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; CGz</span>}}\end{array}\right]<span\; class="notranslate">\; =</span>\left[\begin{array}{ccc}\mathrm{<span\; class="notranslate">\; 1</span>}& \frac{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 3</span>}}{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}& <span\; class="notranslate">\; -</span>\frac{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 3</span>}}{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}\\ \mathrm{<span\; class="notranslate">\; 0</span>}& \frac{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}& \frac{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}\\ \mathrm{<span\; class="notranslate">\; 0</span>}& \frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}& <span\; class="notranslate">\; -</span>\frac{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}\end{array}\right]\left[\begin{array}{c}\mathrm{<span\; class="notranslate">\; x</span>}\\ {\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\\ {\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}\end{array}\right]$

In summary, a large-stroke high-speed dual-drive nano-positioning system of the present invention, through the introduction of a PMAC control board with a high-performance DSP chip as the core, performs multi-axis real-time control of the positioning system, greatly improving the response of the positioning system Speed and real-time; the servo control loop adopts multi-loop feedback control, so that the system can not only suppress vibration, but also has good tracking characteristics, and on this basis, filter technology is used to further suppress the mechanical resonance of the system, reducing the control difficulty; through The simple and easy decoupling of the position and coordinates of the micro-motion stage ensures the high efficiency of system control, thereby improving the control accuracy and response speed of the system.

Claims (1)

1. a large travel high-speed double drive axis Nano-positioners, it is characterized in that: described axis Nano-positioners comprises movement locus order set (101), main control computer (102), PMAC motion control board (103), servo control system (104), locating platform and Measurement and Control System (107), wherein said locating platform comprises grand moving platform (105) and micropositioner (106), by grand moving platform, complete high-speed motion, carry out coarse positioning, solve the speed issue of whole axis Nano-positioners, then by micropositioner, complete accurate Micro-positioning, first this axis Nano-positioners utilizes movement locus order set (101) to carry out trajectory planning to locating platform, recycling movement locus order set (101) is by trajectory planning instruction input main control computer (102), main control computer (102) sends to PMAC motion control board (103) by PEWIN interface by trajectory planning instruction, PMAC motion control board (103) is controlled locating platform by the parameter of setting and trajectory planning instruction and is realized running fix, while Measurement and Control System (107) is grand moving platform (105) and micropositioner (106) physical location of detection and location platform constantly, and by detection signal real-time Transmission to PMAC motion control board (103), PMAC motion control board (103) is through sampling processing, error is calculated and error compensation, Real-time Feedback is to servo control system (104), thereby guarantee the quick tracking response speed of locating platform and nano level kinematic accuracy,

Control to locating platform is specially: grand moving platform is driven by long stroke linear electric motors, realizes long stroke, high-speed motion, and micropositioner is driven by short stroke planar motor, realizes high precision fine tuning; Long stroke is comprised of X-direction and each permanent-magnetism linear motor of Y-direction, and Y-direction motor stator and X-direction electric mover machinery connect firmly, and adopts linear grid ruler to form close-loop feedback and controls; Short stroke level is controlled by Lorentz lorentz's planar motor to motion, and Lorentz lorentz's motor is comprised of 3 magnetic motors, and its stator coil and Y-direction linear motor rotor machinery connect firmly, and adopts 3 axle laser interferometer to make position probing and forms close-loop feedback control;

When planar motor is driven, planar motor is carried out to mobile decoupling, due to when system is located, the position command that main control computer is issued locating platform is micropositioner (x _cG, y _cG, θ _cGz) to desired location, and micropositioner drive motor output be an x to the position of two y to motor, so before being controlled, micropositioner needs first its drive motor to be carried out to coordinate conversion, with the high efficiency that guarantees to control, thus control accuracy and the response speed of raising system;

The control of described locating platform takes principal and subordinate to control, and short stroke motor is main control object, with laser interferometer measurement, feeds back, complete high-precision motion among a small circle, long-range motor as short distance motor from control system, with linear grid ruler, measure feedback, complete long travel high-speed and slightly move; Between length stroke, the relative position of pursuit movement is detected by linear grid ruler, when detecting work stage, linear grid ruler moves to target location when setpoint distance is several microns, stop the motion of long-range motor, be switched to short distance motor movement, until micropositioner reaches target location, and always attempting to keep both relative positions from moving is zero, to guarantee high kinematic accuracy and the quick tracking response speed of following the tracks of;

This positioning system is in order to obtain the location of instruction (x of input _cG, y _cG, θ _cGz) and motor input position (x, y ₁, y ₂) between relation, position command can be completed in two steps, first micropositioner centroid position is moved to the location of instruction (x _cG, y _cG) locate, then micropositioner is rotated to θ around z axle _cGz;

Micropositioner centroid position moves to the location of instruction (x _cG, y _cG) while locating, now motor position (x ', y ₁', y ₂') and instruction position (x _cG, y _cG, θ _cGz) pass be:

$\left\{\begin{array}{c}{x}^{\&prime;}=x_{\mathrm{CG}}\\ {y_1}^{\&prime;}=y_{\mathrm{CG}}\\ {y_2}^{\&prime;}=y_{\mathrm{CG}}\end{array}\right.$

S1 is y ₁motor center of gravity and micropositioner barycenter are in the distance of x axle, and S2 is y ₂motor center of gravity and micropositioner barycenter be in the distance of x axle, S3 be x motor center of gravity and micropositioner barycenter in the distance of y axle, S1, S2 and S3 are constant;

Micropositioner is rotated to θ _cGzafter, the position of x motor is:

x＝x′-S3*sinθ _CGz

Due to y ₁, y ₂motor is symmetrical about x motor, so y ₁, y ₂the position of motor is:

$\left\{\begin{array}{c}{y}_1={y_1}^{\&prime;}-S3*(1-\cos {\mathrm{\&theta;}}_{\mathrm{CGz}})+S1*\sin {\mathrm{\&theta;}}_{\mathrm{CGz}}\\ y_2={y_2}^{\&prime;}-S3*(1-\cos {\mathrm{\&theta;}}_{\mathrm{CGz}})-S2*\sin {\mathrm{\&theta;}}_{\mathrm{CGz}}\end{array}\right.$

Comprehensive above formula can obtain,

$\left\{\begin{array}{c}x=x_{\mathrm{GC}}-S3*\sin {\mathrm{\&theta;}}_{\mathrm{CGz}}\\ y_1=y_{\mathrm{CG}}-S3*(1-\cos {\mathrm{\&theta;}}_{\mathrm{CGz}})+S1*\sin \\ y_2=y_{\mathrm{CG}}-S3*(1-\cos {\mathrm{\&theta;}}_{\mathrm{CGz}})-S2*\sin {\mathrm{\&theta;}}_{\mathrm{CGz}}\end{array},{\mathrm{\&theta;}}_{\mathrm{CGz}}\right.$

Above formula conversion can obtain,

$\left\{\begin{array}{c}{x}_{\mathrm{CG}}=x-\frac{S3}{S1+S2}(y_1-y_2)\\ y_{\mathrm{CG}}=\frac{1}{S1+S2}(S1*y_2+S2*y_1)+S3*(1-\cos {\mathrm{\&theta;}}_z)\\ {\mathrm{\&theta;}}_{\mathrm{CGz}}=\arcsin \frac{y_1-y_2}{S1+S2}\end{array}\right.$

Work as θ _cGzwhen very little, motor position (x, y ₁, y ₂) and instruction position (x _cG, y _cG, θ _cGz) relation, forward position coordinate conversion expression formula is:

$\left[\begin{array}{c}x\\ y_1\\ y_2\end{array}\right]=\left[\begin{array}{ccc}1& 0& -S3\\ 0& 1& S1\\ 0& 1& -S2\end{array}\right]\left[\begin{array}{c}{x}_{\mathrm{CG}}\\ y_{\mathrm{CG}}\\ {\mathrm{\&theta;}}_{\mathrm{CGz}}\end{array}\right]$

By above formula, converted, the reverse position coordinates converting expressing formula that can obtain drive motor is:

$\left[\begin{array}{c}{x}_{\mathrm{CG}}\\ y_{\mathrm{CG}}\\ {\mathrm{\&theta;}}_{\mathrm{CGz}}\end{array}\right]=\left[\begin{array}{ccc}1& \frac{S3}{S1+S2}& -\frac{S3}{S1+S2}\\ 0& \frac{S2}{S1+S2}& \frac{S1}{S1+S2}\\ 0& \frac{1}{S1+S2}& -\frac{S1}{S1+S2}\end{array}\right]\left[\begin{array}{c}x\\ y_1\\ y_2\end{array}\right].$