Macro-micro precise positioning device and control method

Abstract

A macro-micro precision positioning device includes: a base with a linear guide rail and a linear macro drive; a macro platform slidably connected to the linear guide rail, the macro platform having a linear micro drive and a flexible translation mechanism; a micro platform slidably connected to the macro platform via the flexible translation mechanism, the linear micro drive acting on the micro platform to control its movement distance; a relative displacement sensor for detecting the displacement of the micro platform relative to the macro platform; the linear macro drive acting on the macro platform, and determining whether to control the macro platform to respond to the movement of the micro platform based on the feedback signal from the relative displacement sensor. This solution combines the precision displacement of the linear micro drive with the large stroke of the linear macro drive, while reducing the frequent start-stop problem of the linear macro drive through a control strategy that uses the micro platform to drive the macro platform, thus improving work efficiency and operational accuracy. This disclosure also provides a control method for the macro-micro precision positioning device.

Description

Technical Field

[0001] This invention relates to the technical field of precision positioning, specifically to a macro-micro precision positioning device and a control method for the macro-micro precision positioning device. Background Technology

[0002] Macro-micro motion platforms are formed by superimposing a high-precision motion platform onto a low-precision motion platform, leveraging the complementary advantages of the long stroke of the macro platform and the high precision of the micro platform. Linear motors directly drive the platform's motion, achieving a range of motion up to hundreds of millimeters, but with only micrometer-level precision. While air levitation or magnetic levitation can improve the precision to sub-micrometer levels, it still falls short of the micro-nano positioning requirements of precision equipment. Voice coil motors, as a special type of linear motor, offer advantages such as simple structure, small size, fast dynamic response, cogging torque, and high linearity. They can achieve cross-scale motion capabilities with millimeter-level stroke and nanometer-level precision, and are widely used in high-precision positioning servo systems. In addition, piezoelectric ceramic motors are another common type of precision motor used in motion control. Because they lack an internal magnetic field and moving parts, they achieve precision unmatched by linear and rotary motors, reaching the nanometer level. However, the working principle of piezoelectric ceramics utilizes the inverse piezoelectric effect, deforming according to changes in applied voltage, resulting in a limited stroke, only at the hundred-micrometer level. Furthermore, as a polar material, the nonlinear material properties of piezoelectric ceramics, such as hysteresis, temperature, and creep, can affect the precision positioning effect.

[0003] For example, patent CN 203269552 U proposes a high-speed, high-precision macro-micro platform based on piezoelectric ceramics. This invention achieves high-speed feeding through a large-stroke motion driven by a voice coil motor. The piezoelectric ceramic is directly connected to the output shaft of the voice coil motor, driving the micro-platform movement and providing vibration reduction and precise positioning for the high-speed platform. A linear encoder for the voice coil motor provides feedback on the motor's position signal, and an absolute optical grating ruler is used for closed-loop control of the micro-platform. Meanwhile, patent CN 104656682A proposes a two-stage macro-micro drive precision positioning mechanism. This invention designs a two-stage macro-micro drive precision positioning mechanism based on a macro positioning system driven by a linear motor and a micro positioning system driven by piezoelectric ceramics. High-precision linear motion is achieved through the cooperation of air-bearing guides and moving sliders at each stage of motion, as well as closed-loop control using a laser interferometer.

[0004] However, the micro-stage travel of existing macro-micro platforms is only tens of micrometers, and they usually adopt the method of moving the macro stage first and then the micro stage. In the process of precision positioning, the macro stage needs to be started and stopped frequently. Considering that the accuracy of the micro stage is more sensitive to the interference of the macro stage, the stabilization time is long, which reduces the work efficiency. Summary of the Invention

[0005] The purpose of this invention is to provide a macro-micro precision positioning device to reduce the problem of frequent start-stop of the macro stage in the prior art, reduce the interference of the macro stage on the micro stage, and improve the working efficiency and operation accuracy of the macro-micro platform.

[0006] To address the above problems, the present invention provides a macro-micro precision positioning device, comprising:

[0007] The base is equipped with linear guides and a linear macro drive.

[0008] A macro-motion platform is slidably connected to the linear guide rail, and the macro-motion platform is equipped with a linear micro-drive component and a flexible translation mechanism;

[0009] The micro-motion platform is slidably connected to the macro-motion platform through the flexible translation mechanism, and the linear micro-drive acts on the micro-motion platform to control the movement distance of the micro-motion platform;

[0010] A macro-motion displacement sensor is mounted on the base and used to detect the displacement of the macro-motion platform;

[0011] A micro-motion displacement sensor is mounted on the base and used to detect the displacement of the micro-motion platform;

[0012] A relative displacement sensor is mounted on the macro-motion platform and used to detect the displacement of the micro-motion platform relative to the macro-motion platform;

[0013] The linear macro actuator acts on the macro platform, and the linear macro actuator determines whether to control the macro platform to respond to the movement of the micro platform based on the feedback signal of the relative displacement sensor.

[0014] Preferably, the linear macro actuator is a linear motor arranged laterally, and the linear micro actuator is a voice coil motor. The stator of the voice coil motor is connected to the macro platform, and the mover is connected to the micro platform. The axis of the voice coil motor is parallel to that of the linear motor. The linear motor has a simple structure, does not require an additional transmission mechanism, and responds quickly; while the voice coil motor can achieve millimeter-level precision movement, enabling precise control of the movement distance of the micro platform.

[0015] Preferably, the base is provided with two stops, which are located at both ends of the linear guide rail for the macro-motion platform to abut against, thereby limiting the maximum stroke of the macro-motion platform and preventing the macro-motion platform from dislodging from the linear guide rail.

[0016] The above solution uses a voice coil motor as a linear micro-actuator to achieve millimeter-level precision displacement and a linear motor as a linear macro-actuator to achieve large-stroke displacement. Simultaneously, the micro-motion platform is slidably connected to the macro-motion platform via a flexible translation mechanism. This flexible translation mechanism provides frictionless motion guidance for the micro-motion platform, ensuring more stable displacement. Compared to existing technologies, this solution combines the precision displacement of linear micro-actuators with the large stroke of linear macro-actuators. Furthermore, it reduces the frequent start-stop issues of the linear macro-actuator through a coordinated motion control strategy that uses the micro-motion platform to drive the macro-motion platform. Feedforward decoupling compensation reduces the impact of coupling force interference on the micro-motion platform and suppresses interference from the macro-motion platform, improving the overall efficiency and accuracy of the positioning device. This enables long-stroke precision positioning for precision manufacturing equipment such as optoelectronic devices and semiconductor chips.

[0017] The present invention also provides a control method for a macro-micro precision positioning device, comprising the following steps:

[0018] S1. The host computer issues a displacement command, and the linear micro-drive responds to the displacement command to control the micro-motion platform to move in the corresponding direction;

[0019] S2. The relative displacement sensor detects the position and displacement of the micro-motion platform relative to the macro-motion platform. The host computer analyzes the feedback signal from the relative displacement sensor: if the value of the displacement command is greater than the idle stroke of the micro-motion platform, the linear macro actuator controls the linear macro actuator to move in the same direction as the micro-motion platform, and feeds forward compensation for the interference of the macro-motion platform on the micro-motion platform based on the coupling identification model, until the macro-motion displacement sensor detects that the macro-motion platform has moved to the required position. Then, the displacement is completed when the micro-motion displacement sensor detects that the micro-motion platform has moved to the required position. If the value of the displacement command is less than the idle stroke of the micro-motion platform, the linear macro actuator remains closed. Attached Figure Description

[0020] Figure 1 This is an isometric schematic diagram of a macro-micro precision positioning device;

[0021] Figure 2 This is a front view schematic diagram of a macro-micro precision positioning device;

[0022] Figure 3 This is a schematic diagram of the macro-motion platform and the micro-motion platform of a macro-micro precision positioning device.

[0023] Explanation of reference numerals in the attached figures.

[0024] 1. Base; 11. Linear guide rail; 12. Stop; 2. Linear macro drive; 3. Macro platform; 4. Linear micro drive; 5. Micro platform; 6. Flexible translation mechanism; 61. Slide; 62. Slide table; 7. Macro displacement sensor; 8. Micro displacement sensor; 9. Relative displacement sensor. Detailed Implementation

[0025] To make the above-mentioned objectives, features, and advantages of the present invention more apparent and understandable, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. It should also be noted that all directional indications (such as up, down, left, right, front, back, inside, outside) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of the components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0026] Example 1

[0027] Please see Figures 1-3 An embodiment of the present invention provides a macro-micro precision positioning device, comprising:

[0028] The base 1 is provided with a linear guide rail 11 and a linear macro drive 2;

[0029] The macro-motion platform 3 is slidably connected to the linear guide rail 11. The macro-motion platform 3 is equipped with a linear micro-drive component 4 and a flexible translation mechanism 6.

[0030] The micro-motion platform 5 is slidably connected to the macro-motion platform 3 through the flexible translation mechanism 6, and the linear micro-drive component 4 acts on the micro-motion platform 5 to control the movement distance of the micro-motion platform 5.

[0031] The macro-motion displacement sensor 7 is mounted on the base 1 and is used to detect the displacement of the macro-motion platform 3;

[0032] A micro-motion displacement sensor 8 is mounted on the base 1 and is used to detect the displacement of the micro-motion platform 5;

[0033] A relative displacement sensor 9 is mounted on the macro-motion platform 3 and is used to detect the displacement of the micro-motion platform 5 relative to the macro-motion platform 3;

[0034] The linear macro actuator 2 acts on the macro platform 3, and the linear macro actuator 2 determines whether to control the macro platform 3 to respond to the movement of the micro platform 5 based on the feedback signal of the relative displacement sensor 9.

[0035] In this embodiment, the linear macro actuator 2 is a linear motor arranged laterally, and the linear micro actuator 4 is a voice coil motor arranged laterally, with the axis of the voice coil motor parallel to that of the linear motor. The stator of the voice coil motor is connected to the macro actuator platform 3, and the mover is connected to the micro actuator platform 5. The linear motor has a simple structure, requires no additional transmission mechanism, and responds quickly; while the voice coil motor can achieve millimeter-level precision movement, enabling precise control of the movement distance of the micro actuator platform 5.

[0036] The flexible translation mechanism 6 includes a slide block 61 and a slide table 62. The slide block 61 is laterally connected to the macro-motion platform 3, and the slide table 62 is slidably connected to the slide block 61. The sliding direction of the slide table 62 relative to the slide block 61 is parallel to the axis of the voice coil motor. The flexible translation mechanism 6 can provide frictionless motion guidance for the micro-motion platform 5, ensuring more stable displacement of the micro-motion platform 5.

[0037] As an optimization of the above embodiment, the base 1 is provided with two baffles 12, which are located at both ends of the linear guide rail 11 for the macro-motion platform 3 to abut against, thereby limiting the maximum stroke of the macro-motion platform 3 and preventing the macro-motion platform 3 from dislodging from the linear guide rail 11.

[0038] The above solution uses a voice coil motor as a linear micro-actuator 4 to achieve millimeter-level precision displacement, and a linear motor as a linear macro-actuator 2 to achieve large-stroke displacement. Simultaneously, the micro-motion platform 5 is slidably connected to the macro-motion platform 3 via a flexible translation mechanism 6. The flexible translation mechanism 6 provides frictionless motion guidance for the micro-motion platform 5, ensuring more stable displacement. Compared with existing technologies, this solution combines the precision displacement of the linear micro-actuator 4 with the large stroke of the linear macro-actuator 2. Furthermore, it reduces the frequent start-stop problem of the linear macro-actuator 2 through a coordinated motion control strategy using the micro-motion platform 5 to drive the macro-motion platform 3, and reduces the impact of coupling force interference on the micro-motion platform 5 through feedforward decoupling compensation, suppressing interference from the macro-motion platform 3 on the micro-motion platform 5. This improves the overall efficiency and accuracy of the positioning device, enabling long-stroke precision positioning for precision manufacturing equipment such as optoelectronic devices and semiconductor chips.

[0039] Example 2

[0040] Embodiment 2 of the present invention provides a control method for a macro-micro precision positioning device, applied as in Embodiment 1, and specifically includes the following steps:

[0041] S1. The host computer issues a displacement command, and the linear micro-drive 4 responds to the displacement command to control the micro-motion platform 5 to move in the corresponding direction;

[0042] S2. The relative displacement sensor 9 detects the position and displacement of the micro-motion platform 5 relative to the macro-motion platform 3. The host computer analyzes the feedback signal from the relative displacement sensor 9: If the value of the displacement command is greater than the free travel of the micro-motion platform 5, the linear macro drive 2 controls the linear macro drive 2 to move in the same direction as the micro-motion platform 5, and feeds forward to compensate for the interference of the macro-motion platform 3 on the micro-motion platform 5 based on the coupling identification model, until the macro-motion displacement sensor 7 detects that the macro-motion platform 3 has moved to the required position, and then waits for the micro-motion displacement sensor 8 to detect that the micro-motion platform 5 has moved to the required position, and the displacement is completed; if the value of the displacement command is less than the free travel of the micro-motion platform 5, the linear macro drive 2 remains closed.

[0043] While the disclosure is as stated above, its scope of protection is not limited thereto. Those skilled in the art will be able to make various changes and modifications without departing from the spirit and scope of this disclosure, and all such changes and modifications will fall within the scope of protection of the invention.

Claims

1. A control method for a macro-micro precision positioning device, applied to the macro-micro precision positioning device, the macro-micro precision positioning device comprising: The base (1) is provided with a linear guide rail (11) and a linear macro drive (2); The macro-motion platform (3) is slidably connected to the linear guide rail (11), and the macro-motion platform (3) is provided with a linear micro-drive component (4) and a flexible translation mechanism (6); The micro-motion platform (5) is slidably connected to the macro-motion platform (3) through the flexible translation mechanism (6), and the linear micro-drive (4) acts on the micro-motion platform (5) to control the movement distance of the micro-motion platform (5); A macro-motion displacement sensor (7) is mounted on the base (1) and used to detect the displacement of the macro-motion platform (3); A micro-motion displacement sensor (8) is mounted on the base (1) and used to detect the displacement of the micro-motion platform (5); A relative displacement sensor (9) is installed on the macro-motion platform (3) and used to detect the displacement of the micro-motion platform (5) relative to the macro-motion platform (3); The linear macro actuator (2) acts on the macro platform (3), and the linear macro actuator (2) determines whether to control the macro platform (3) to respond to the movement of the micro platform (5) based on the feedback signal of the relative displacement sensor (9); Its features are, Includes the following steps: S1. The host computer issues a displacement command, and the linear micro-drive (4) responds to the displacement command to control the micro-motion platform (5) to move in the corresponding direction; S2. The relative displacement sensor (9) detects the position and displacement of the micro-motion platform (5) relative to the macro-motion platform (3). The host computer analyzes the feedback signal of the relative displacement sensor (9): If the value of the displacement command is greater than the idle stroke of the micro-motion platform (5), the linear macro drive (2) controls the macro-motion platform (3) to move in the same direction as the micro-motion platform (5), and feeds forward to compensate for the interference of the macro-motion platform (3) on the micro-motion platform (5) based on the coupling identification model, until the macro-motion displacement sensor (7) detects that the macro-motion platform (3) has moved to the required position, and then waits for the micro-motion displacement sensor (8) to detect that the micro-motion platform (5) has moved to the required position, and the displacement is completed; if the value of the displacement command is less than the idle stroke of the micro-motion platform (5), the linear macro drive (2) remains closed.

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