A multi-mode piezoelectric nano-motion platform and intelligent control method

Abstract

The present invention provides a multi-mode piezoelectric nano-motion platform and intelligent control method. A preload module is provided on one side of a base module, and a step drive module is provided on the preload module. The preload module provides an adjustable preload force for the step drive module. A slider module is provided on the other side of the base module. The grating scale displacement sensor module and the force sensor module are respectively used to obtain displacement data of the slider in the slider module, as well as force information in the horizontal and vertical directions. The step drive module includes a triangular motion foot, a fixed frame, and a step drive module support frame. Two triangular motion feet are symmetrically arranged side by side in front of the step drive module support frame. The two ends of the step drive module support frame are fixed frames, and piezoelectric ceramics are arranged in the fixed frame. The two triangular motion feet can form contact with the slider module at the front end, driving the slider to achieve stick-slip or inchworm motion. The present invention has the advantages of superior overall performance, strong complementarity between modes, and adaptive mode adjustment.

Description

Technical Field

[0001] The present invention belongs to the field of precision machinery technology, and in particular relates to a multi-mode piezoelectric nano-motion platform and an intelligent control method. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] In recent years, with the continuous improvement of science and technology and industrial level, the fields of integrated circuit equipment manufacturing, photolithography machine preparation, microelectronics manufacturing, micro-robot operation, precision optical instruments and biomedical operation have developed rapidly. The operating environment of high-precision motion platforms has become more and more extreme. There is an urgent need for motion platforms with large stroke, high speed, large load and high precision to meet extreme working conditions.

[0004] Traditional piezoelectric motion platforms are divided into two types: direct-drive and stepper-drive. Direct-drive platforms offer high precision and zero backoff, but their travel is limited, reaching a maximum micrometer range. Stepper-drive platforms offer the advantages of large travel, high speed, and high load capacity, but their motion accuracy is far lower than that of direct-drive platforms. Currently proposed multi-mode piezoelectric actuators still suffer from weak overall performance, poor complementarity between modes, and the inability to adaptively adjust modes, making them difficult to meet the demands of growing industry. Summary of the Invention

[0005] In order to solve the above problems, the present invention proposes a multi-mode piezoelectric nano-motion platform and an intelligent control method. The present invention has the advantages of superior comprehensive performance, strong complementarity between modes and adaptive adjustment of modes.

[0006] According to some embodiments, the present invention adopts the following technical solutions:

[0007] A multi-mode piezoelectric nano-motion platform includes a step drive module, a preload module, a slider module, a grating scale displacement sensor module, a force sensor module and a base module, wherein:

[0008] A pre-tightening module is provided on one side of the base module, a step-drive module is provided on the pre-tightening module, and the pre-tightening module provides an adjustable pre-tightening force for the step-drive module;

[0009] A slider module is provided on the other side of the base module, and the grating scale displacement sensor module and the force sensor module are used to obtain the displacement data of the slider in the slider module, as well as the force information in the horizontal and vertical directions respectively;

[0010] The step drive module includes a triangular motion foot, a fixed frame and a step drive module support frame. The step drive module support frame is connected to the pre-tightening module. The step drive module support frame faces one end of the slider module and has two triangular motion feet symmetrically arranged side by side. The two ends of the step drive module support frame are fixed frames, and piezoelectric ceramics are arranged in the fixed frames. The two triangular motion feet can form contact with the slider module at the front end, driving the slider to achieve stick-slip or inchworm motion.

[0011] As an optional embodiment, it also includes a controller, which is electrically connected to the grating scale displacement sensor module and the force sensor module, and is used to determine the working mode of the multi-mode piezoelectric nano-motion platform according to the displacement of the slider and the force information in the horizontal and vertical directions, and to control the actions of the pre-tightening module and the step drive module.

[0012] As an optional embodiment, the pre-tensioning module includes a guide leaf spring, a pre-tensioning module support frame, a pre-tensioning displacement amplification mechanism and a step-drive module receiving platform, wherein the step-drive module receiving platform is arranged at the front end of the pre-tensioning module support frame for fixing the step-drive module, and the guide leaf spring is used to fix the step-drive module receiving platform, while ensuring the horizontality of the output displacement of the pre-tensioning displacement amplification mechanism; the pre-tensioning displacement amplification mechanism adopts a bridge-type displacement amplification structure, the front end of which is connected to the step-drive module receiving platform and the rear end is connected to the pre-tensioning module support frame, and an accommodating space is provided in the middle for fixing the pre-tensioning piezoelectric ceramics to achieve amplification of the output displacement of the pre-tensioning piezoelectric ceramics.

[0013] As a further embodiment, the pre-tightening module support frame is provided with a plurality of fixing holes for fixing the pre-tightening module on the base module.

[0014] As an optional embodiment, the grating scale displacement sensor module includes a grating scale and a grating scale reading head. The grating scale is fixed on the slider, and the grating scale reading head is fixed on the base module for reading the grating scale value to realize the output of the displacement data of the slider.

[0015] As an optional embodiment, the force sensor module includes an output force sensor and a bearing force sensor. The output force sensor is fixed on the slider and is used to measure the force information exerted on the slider in the horizontal direction. The bearing force sensor is fixed on the base module through a sensor fixing plate and is used to measure the force information exerted on the slider in the vertical direction.

[0016] As an optional embodiment, the slider module includes a slider, the top of the slider is provided with an output force sensor fixing groove, the bottom of the slider is provided with a slide rail groove, the slide rail groove is used to be slidably connected with the slide rail provided on the base module, and the side of the slider facing the step drive module is provided with a grating scale fixing groove.

[0017] As an optional embodiment, the base module includes a sensor fixing plate and a base, the upper end of the sensor fixing plate is connected to the load-bearing force sensor, and the lower end is fixed on the base, and the base is provided with a grating scale reading head fixing groove and a base fixing hole, and the base fixing hole is used to fix the entire motion platform.

[0018] The intelligent control method of the multi-mode piezoelectric nano-motion platform comprises the following steps:

[0019] Obtaining displacement data and horizontal and vertical force information of the slider, and determining whether it is necessary to switch the working mode of the multi-mode piezoelectric nano-motion platform based on the displacement data or force information;

[0020] If so, according to the current working mode and the target working mode, the piezoelectric ceramics of different triangular motion feet and / or the piezoelectric ceramics of the preload module are stimulated to realize the execution and switching of stick-slip, inchworm and / or large-stroke scanning motion modes.

[0021] As an optional embodiment, the stick-slip motion mode is achieved by adding a sawtooth wave excitation voltage to the piezoelectric ceramic of the triangular motion foot, so that the triangular motion foot can achieve a slow stick-fast slip motion mode;

[0022] The inchworm motion mode is achieved by the cooperation of the two triangular motion feet of the step drive module. Specifically, the triangular motion foot on one side drives the slider to move forward, and the triangular motion foot on the other side moves backward to press the slider tightly. The triangular motion foot on one side returns to its initial state, and the triangular motion foot on the other side returns to its initial state while driving the slider to move forward for another displacement, thus completing a motion cycle. This mode does not produce a backward displacement.

[0023] The large-stroke scanning motion mode is realized by the cooperation of the triangular motion foot and the pre-tightening module. Specifically, the triangular motion foot moves forward in a single step, and then the piezoelectric ceramic voltage of the pre-tightening module is stimulated to push the slider forward for a certain displacement. The two displacements are accumulated to realize the large-stroke scanning motion mode.

[0024] As an optional implementation, the process of determining whether to switch the working mode of the multi-mode piezoelectric nano-motion platform according to the displacement data or force information includes:

[0025] Based on the switching strategy of the output force sensor data, when there is an output force value, the preload module adjusts the corresponding preload force according to the output force value and adopts the inchworm mode for control; when there is no output force value, the stick-slip mode is used for control;

[0026] The switching strategy is based on the bearing capacity sensor data. When there is a bearing capacity value, it is determined whether the bearing capacity value is greater than the set threshold. If the bearing capacity value is greater than or equal to the threshold, the inchworm mode is used for control. If the bearing capacity value is less than the threshold, the stick-slip mode is used for control. When there is no bearing capacity value, the stick-slip mode is used for control.

[0027] Based on the switching strategy of the displacement sensor, after completing the inchworm or stick-slip full-step motion, the slider displacement data is obtained through the grating ruler, and the large-stroke scanning mode is used to achieve precise positioning of the multi-mode piezoelectric actuator.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] (1) The piezoelectric nano-motion platform proposed in the present invention realizes stick-slip, inchworm and large-stroke scanning motion modes through the cooperation of the step drive module and the preload module, taking the advantages of each motion mode, so that the motion platform has unlimited stroke, high speed, large load, high precision, and bidirectional non-retraction motion, meeting the use requirements of extreme working conditions;

[0030] (2) The three working modes of the piezoelectric nano-motion platform proposed in the present invention can be converted into each other, and the shortcomings of each mode can be compensated, such as the stick-slip mode compensates for the shortcomings of the slow movement speed of the inchworm mode, the inchworm mode compensates for the shortcomings of the low load capacity of the stick-slip mode, the large-stroke scanning mode compensates for the shortcomings of the stick-slip and inchworm modes with low positioning accuracy, and the stick-slip and inchworm modes compensate for the shortcomings of the small stroke of the scanning mode;

[0031] (3) The piezoelectric nano-motion platform proposed in the present invention can achieve automatic pre-tightening through the pre-tightening module, with a high degree of automation; at the same time, the motion mode can be adaptively adjusted according to working conditions to meet more engineering application needs.

[0032] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0034] Figure 1 is an overall schematic diagram of a motion platform according to an embodiment;

[0035] Figure 2 This is a schematic diagram of a step-drive module of a motion platform according to an embodiment;

[0036] Figure 3 is a schematic diagram of a motion platform pre-tightening module according to an embodiment;

[0037] Figure 4 is a schematic diagram of a motion platform slider module according to an embodiment;

[0038] Figure 5 is a schematic diagram of a sensor fixing plate according to an embodiment;

[0039] Figure 6 is a schematic diagram of a motion platform base module according to an embodiment;

[0040] Figure 7 is a schematic diagram of a stick-slip motion working mode of a motion platform according to an embodiment;

[0041] Figure 8 This is a schematic diagram of a inchworm motion working mode of a motion platform according to an embodiment;

[0042] Figure 9 This is a schematic diagram of a large-stroke scanning motion working mode of a motion platform according to an embodiment;

[0043] Figure 10 This is an overall block diagram of a motion platform intelligent control method according to an embodiment;

[0044] Figure 11 is a block diagram of a strategy for switching between different modes of a motion platform according to an embodiment;

[0045] In the figure, 1-step drive module, 2-pretightening module, 3-base, 4-grating displacement sensor module, 5-sensor fixing plate, 6-slide rail, 7-load-bearing force sensor, 8-slider, 9-output force sensor, 10-triangular motion foot, 11-triangular motion foot ceramic fixing frame, 12-triangular motion foot ceramic pretightening bolt, 13-step drive module support frame, 14-step drive module support frame fixing hole, 15-guide leaf spring, 16-pretightening module support frame, 17-pretightening module support frame fixing hole, 18-pretightening ceramic pretightening bolt, 19-pretightening displacement amplification mechanism, 20-step drive module receiving platform, 21-output force sensor fixing slot, 22-grating scale fixing slot, 23-slide rail slot, 24-sensor fixing plate fixing hole, 25-load-bearing force sensor fixing slot, 26-base plate fixing hole, 27-grating reading head fixing slot. DETAILED DESCRIPTION

[0046] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0047] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0048] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0049] In the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0050] Example 1

[0051] A multi-mode piezoelectric nano-motion platform that combines the advantages of direct-push and stepper piezoelectric motion platforms. It has the advantages of compact structure, large stroke, high speed, large load, nanometer-level precision, and bidirectional non-retraction. At the same time, it can adaptively adjust the motion mode according to the working conditions to meet the needs of more complex engineering applications.

[0052] Specifically, a multi-mode piezoelectric nano-motion platform includes a step drive module, a pre-tightening module, a slider module, a grating scale displacement sensor module, a force sensor module and a base module.

[0053] The step-drive module consists of two symmetrical triangular motion feet, a triangular motion foot ceramic mounting bracket, and a step-drive module support bracket. The step-drive module support bracket has mounting holes that are bolted to a lower preload module. The piezoelectric ceramics of the triangular motion feet are fixed to the triangular motion foot ceramic mounting bracket via preload bolts. The two triangular motion feet contact the front slider module, driving the slider to achieve stick-slip and inchworm motion.

[0054] The pre-tightening module includes a guide leaf spring, a pre-tightening module support frame, a pre-tightening displacement amplification mechanism and a step-drive module receiving platform. The step-drive module receiving platform is used to fix the upper step-drive module. The guide leaf spring is used to fix the step-drive module receiving platform and at the same time ensure the horizontality of the output displacement of the pre-tightening displacement amplification mechanism. The pre-tightening displacement amplification mechanism adopts a bridge-type displacement amplification structure, with the front end connected to the step-drive module receiving platform and the rear end connected to the pre-tightening module support frame. After the pre-tightening piezoelectric ceramic is fixed in the middle, the output displacement of the pre-tightening piezoelectric ceramic can be amplified. The pre-tightening module support frame is provided with a fixing hole for fixing the pre-tightening module on the base module.

[0055] The slider module includes an output force sensor fixing slot, a grating ruler fixing slot and a slide rail slot. The slide rail slot is used to connect with the lower end slide rail to realize the movement of the slider module.

[0056] The grating scale displacement sensor module includes a grating scale and a grating scale reading head. The grating scale is fixed on the slider. The grating scale reading head is fixed on the base module to read the grating scale value and realize the output of the slider displacement data.

[0057] The force sensor module includes an output force sensor and a load-bearing force sensor. The output force sensor is fixed to the slider and is used to measure the force information applied to the slider in the horizontal direction. The load-bearing force sensor is fixed to the base module via a sensor fixing plate and is used to measure the force information applied to the slider in the vertical direction.

[0058] The base module includes a sensor mounting plate and a base. The upper end of the sensor mounting plate is connected to the load-bearing sensor, and the lower end is bolted to the base. The base is provided with a grating scale reading head fixing slot and a base fixing hole for fixing the entire motion platform.

[0059] This embodiment also provides an intelligent control method for the above-mentioned multi-mode piezoelectric nano-motion platform, including a multi-mode piezoelectric nano-motion platform working method and a multi-mode piezoelectric nano-motion platform mode intelligent switching strategy method.

[0060] The multi-mode piezoelectric nano-motion platform working method includes three motion modes: stick-slip, inchworm and large-stroke scanning.

[0061] The stick-slip motion mode is achieved by adding a sawtooth wave excitation voltage to the piezoelectric ceramics of the triangular motion foot, so that the triangular motion foot can achieve a slow stick-fast slip motion mode. Since the triangular motion foot has a symmetrical structural design, the forward and reverse stick-slip motion modes can be achieved by simply changing the piezoelectric ceramics that excite different triangular motion feet.

[0062] The inchworm motion mode is achieved through the cooperation of the two triangular motion feet of the step drive module. Specifically, the left triangular motion foot drives the slider forward, the right triangular motion foot moves backward to press the slider, the left triangular motion foot returns to its initial state, and the right triangular motion foot returns to its initial state while driving the slider to move forward for a certain displacement, thus completing a motion cycle. This mode does not produce a backward displacement.

[0063] The large-stroke scanning motion mode is realized by the cooperation of the triangular motion foot and the pre-tightening module. Specifically, the triangular motion foot moves forward in a single step, and then the piezoelectric ceramic voltage of the pre-tightening module is stimulated to push the slider forward for a certain displacement. The two displacements are accumulated to realize the large-stroke scanning motion mode.

[0064] The intelligent switching strategy method between modes of the multi-mode piezoelectric nano-motion platform is as follows:

[0065] The multi-mode piezoelectric driver data information is obtained through displacement and force sensors, and the mode intelligent switching strategy is designed based on the force and displacement data information. After the mode is determined, it is sent to the controller, and the controller controls the multi-mode piezoelectric driver to move based on the transmitted working mode.

[0066] Based on the switching strategy of the output force sensor data, when there is an output force value, the preload module adjusts the corresponding preload force according to the output force value, and the controller adopts the inchworm mode for control; when there is no output force value, the controller adopts the stick-slip mode for control.

[0067] The switching strategy is based on the bearing capacity sensor data. When there is a bearing capacity value, it is determined whether the bearing capacity value is greater than the set threshold. When the bearing capacity value is greater than or equal to the threshold, the controller adopts the inchworm mode for control. When the bearing capacity value is less than the threshold, the controller adopts the stick-slip mode for control. When there is no bearing capacity value, the controller adopts the stick-slip mode for control.

[0068] Based on the switching strategy of the displacement sensor, after completing the inchworm or stick-slip full-step motion, the slider displacement data is obtained through the grating ruler, and the controller adopts the large-stroke scanning mode to achieve precise positioning of the multi-mode piezoelectric actuator.

[0069] Example 2

[0070] A multi-mode piezoelectric nano-motion platform, such as Figure 1 As shown, it includes a step-drive module 1, a preload module 2, a base module 3, a slider module 8, a grating displacement sensor module 4, a load-bearing force sensor module 7, and an output force sensor module 9. The step-drive module 1 and the preload module 2 are connected in series, and the step-drive module 1 and the slider module 8 are connected in parallel, and both are fixed to the base module 3.

[0071] like Figure 2 As shown, the step drive module support frame 13 has two fixing holes 14, which are used to fix the step drive module 1 to the preload module 2 by bolts. The triangular motion foot ceramic is fixed to the triangular motion foot ceramic fixing frame 11 by preload bolts 12, providing power for the triangular motion foot 10.

[0072] like Figure 3 As shown, the step-drive module receiving platform 20 is provided with a through-hole for fixing the step-drive module 1 as a whole. The guide leaf spring 15 is used to fix the step-drive module receiving platform 20, while also ensuring the horizontality of the output displacement of the preload displacement amplification mechanism 19. The preload displacement amplification mechanism 19 adopts a bridge-type displacement amplification structure, with the front end connected to the step-drive module receiving platform 20 and the rear end connected to the preload module support frame 16. The preload ceramic preload bolt 18 is used to fix the preload piezoelectric ceramic in the middle, which can amplify the output displacement of the preload piezoelectric ceramic. The preload module support frame 16 has four fixing holes 17 for fixing the preload module to the base module 3.

[0073] like Figure 4 As shown, the output force sensor fixing groove 21 fixes the output force sensor 9 , the grating scale fixing groove 22 fixes the grating scale, and the slide rail groove 23 is used to connect with the lower end slide rail 6 to realize the movement of the slider module 8 .

[0074] like Figure 5 、 Figure 6 As shown, the base module includes a sensor fixing plate 5 and a base 3. The sensor fixing plate 5 is provided with two load-bearing force sensor fixing grooves 25 and four sensor fixing plate fixing holes 24. The load-bearing force sensor fixing grooves 25 are used to fix the load-bearing force sensor 9, and the sensor fixing plate fixing holes 24 are used to fix the sensor fixing plate 5 to the base 3. The base 3 is provided with a grating scale reading head fixing groove 27 and three base fixing holes 26. The base fixing holes 26 are used to fix the entire motion platform.

[0075] like Figure 7 As shown, the triangle represents the triangular motion foot and the rectangle represents the slider module. From t0 to t1, the triangular motion foot slowly moves the slider module forward by a distance x1. From t1 to t2, the triangular motion foot quickly returns to its original position. Due to friction, the slider module moves backward by a distance x2, completing a stick-slip operating mode cycle. The actual forward distance is Δx = x1 - x2.

[0076] like Figure 8 As shown, when this embodiment is in the inchworm motion working mode, from time 0 to t0, the left triangular motion foot drives the slider module forward by a distance of x3, and then remains stationary until time t3. At this time, from time t1 to t2, the right triangular motion foot moves backward to press against the slider module, and then remains stationary until time t5. From time t3 to t4, the left triangular motion foot is reset. Since the right triangular motion foot has been pressing against the slider module at this moment, the reset of the left triangular motion foot will not cause the slider module to move backward. At time t4, the left triangular motion foot is completely reset. From time t5 to t6, the right triangular motion foot is reset again, and at the same time, it drives the slider module forward by a distance of x4. Therefore, the actual forward distance of the inchworm motion working mode is Δx = x3 + x4. This mode can achieve forward and backward motion without retraction through the cooperation of the two triangular motion feet.

[0077] like Figure 9 As shown, in this embodiment, during the extended-stroke scanning motion mode, from time 0 to t0, the triangular motion foot drives the slider module forward by a single-step displacement of x5. From t1 to t2, the preload module pushes the triangular motion foot, indirectly driving the slider module forward by a further displacement of x6. Therefore, the actual forward distance in the extended-stroke scanning motion mode is Δx = x5 + x6.

[0078] like Figure 10 As shown, the intelligent control method of this embodiment obtains multi-mode piezoelectric driver data information through displacement and force sensors, implements mode intelligent switching strategy design based on force and displacement data information, and sends the mode to the controller after it is determined. The controller controls the multi-mode piezoelectric driver to move based on the transmitted working mode.

[0079] like Figure 11As shown, the different mode switching strategies of this embodiment specifically include:

[0080] (1) Based on the switching strategy of the output force sensor data, when there is an output force value, the preload module adjusts the corresponding preload force according to the output force value, and the controller adopts the inchworm mode for control; when there is no output force value, the controller adopts the stick-slip mode for control.

[0081] (2) The switching strategy is based on the bearing capacity sensor data. When there is a bearing capacity value, it is determined whether the bearing capacity value is greater than the set 20N threshold. When the bearing capacity value is greater than or equal to the 20N threshold, the controller adopts the inchworm mode for control. When the bearing capacity value is less than the 20N threshold, the controller adopts the stick-slip mode for control. When there is no bearing capacity value, the controller adopts the stick-slip mode for control.

[0082] (3) Based on the switching strategy of the displacement sensor, after completing the inchworm or stick-slip full-step motion, the slider displacement data is obtained through the grating ruler, and the controller uses a large-stroke scanning mode to achieve precise positioning of the multi-mode piezoelectric actuator.

[0083] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made by those skilled in the art that fall within the spirit and principles of the present invention and do not require creative effort are intended to be within the scope of protection of the present invention.

Claims

1. A multi-mode piezoelectric nano-motion platform, characterized by: It includes a step drive module, a preload module, a slider module, a grating scale displacement sensor module, a force sensor module and a base module, among which: A pre-tightening module is provided on one side of the base module, a step-drive module is provided on the pre-tightening module, and the pre-tightening module provides an adjustable pre-tightening force for the step-drive module; A slider module is provided on the other side of the base module. The grating scale displacement sensor module and the force sensor module are used to obtain the displacement data of the slider in the slider module, as well as the force information in the horizontal and vertical directions. Based on the displacement data or force information, it is determined whether the multi-mode piezoelectric nano-motion platform needs to switch its working mode. The process includes: Based on the switching strategy of the output force sensor data, when there is an output force value, the preload module adjusts the corresponding preload force according to the output force value and adopts the inchworm mode for control; when there is no output force value, the stick-slip mode is used for control; The switching strategy is based on the bearing capacity sensor data. When there is a bearing capacity value, it is determined whether the bearing capacity value is greater than the set threshold. If the bearing capacity value is greater than or equal to the threshold, the inchworm mode is used for control. If the bearing capacity value is less than the threshold, the stick-slip mode is used for control. When there is no bearing capacity value, the stick-slip mode is used for control. Based on the switching strategy of the displacement sensor, after completing the inchworm or stick-slip full-step motion, the slider displacement data is obtained through the grating ruler, and the large-stroke scanning mode is used to achieve precise positioning of the multi-mode piezoelectric actuator; The step-drive module includes a triangular motion foot, a fixed frame, and a step-drive module support frame. The step-drive module support frame is connected to the preload module. The step-drive module support frame faces one end of the slider module and is symmetrically arranged side by side. Both ends of the step-drive module support frame are fixed frames, and piezoelectric ceramics are arranged in the fixed frames. The two triangular motion feet can form contact with the slider module at the front end, driving the slider to achieve stick-slip or inchworm motion; The pre-tightening module includes a guide leaf spring, a pre-tightening module support frame, a pre-tightening displacement amplifying mechanism and a step-drive module receiving platform, wherein the step-drive module receiving platform is arranged at the front end of the pre-tightening module support frame for fixing the step-drive module, and the guide leaf spring is used to fix the step-drive module receiving platform and ensure the horizontality of the output displacement of the pre-tightening displacement amplifying mechanism; the pre-tightening displacement amplifying mechanism adopts a bridge-type displacement amplifying structure, the front end of which is connected to the step-drive module receiving platform and the rear end is connected to the pre-tightening module support frame, and an accommodating space is provided in the middle for fixing the pre-tightening piezoelectric ceramic to achieve amplification of the output displacement of the pre-tightening piezoelectric ceramic; The pre-tightening module support frame is provided with a plurality of fixing holes for fixing the pre-tightening module on the base module.

2. The multi-mode piezoelectric nano-motion platform according to claim 1, characterized in that: It also includes a controller, which is electrically connected to the grating scale displacement sensor module and the force sensor module, and is used to determine the working mode of the multi-mode piezoelectric nano-motion platform based on the displacement of the slider and the force information in the horizontal and vertical directions, and to control the actions of the pre-tightening module and the step drive module.

3. The multi-mode piezoelectric nano-motion platform according to claim 1, characterized in that: The grating scale displacement sensor module includes a grating scale and a grating scale reading head. The grating scale is fixed on the slider, and the grating scale reading head is fixed on the base module for reading the grating scale value to realize the output of the displacement data of the slider.

4. The multi-mode piezoelectric nano-motion platform according to claim 1, characterized in that: The force sensor module includes an output force sensor and a bearing force sensor. The output force sensor is fixed on the slider and is used to measure the force information exerted on the slider in the horizontal direction. The bearing force sensor is fixed on the base module through a sensor fixing plate and is used to measure the force information exerted on the slider in the vertical direction.

5. The multi-mode piezoelectric nano-motion platform according to claim 1, characterized in that: The slider module includes a slider, the top of the slider is provided with an output force sensor fixing groove, the bottom of the slider is provided with a slide rail groove, the slide rail groove is used to be slidably connected with the slide rail provided on the base module, and the side of the slider facing the step drive module is provided with a grating scale fixing groove.

6. The multi-mode piezoelectric nano-motion platform according to claim 1, characterized in that: The base module includes a sensor fixing plate and a base. The upper end of the sensor fixing plate is connected to the load-bearing force sensor, and the lower end is fixed to the base. The base is provided with a grating scale reading head fixing groove and a base fixing hole. The base fixing hole is used to fix the motion platform as a whole.

7. The intelligent control method for a multi-mode piezoelectric nano-motion platform according to any one of claims 1 to 6, characterized in that: The following steps are involved: Obtaining displacement data and horizontal and vertical force information of the slider, and determining whether it is necessary to switch the working mode of the multi-mode piezoelectric nano-motion platform based on the displacement data or force information; If so, according to the current working mode and the target working mode, the piezoelectric ceramics of different triangular motion feet and / or the piezoelectric ceramics of the preload module are stimulated to realize the execution and switching of stick-slip, inchworm and / or large-stroke scanning motion modes.

8. The intelligent control method according to claim 7, wherein: The stick-slip motion mode increases the sawtooth wave excitation voltage to the piezoelectric ceramic of the triangular motion foot, so that the triangular motion foot can achieve a slow stick-fast slip motion mode; The inchworm motion mode is achieved by the cooperation of the two triangular motion feet of the step drive module. Specifically, the triangular motion foot on one side drives the slider to move forward, and the triangular motion foot on the other side moves backward to press the slider tightly. The triangular motion foot on one side returns to its initial state, and the triangular motion foot on the other side returns to its initial state while driving the slider to move forward for another displacement, thus completing a motion cycle. This mode does not produce a backward displacement. The large-stroke scanning motion mode is realized by the cooperation of the triangular motion foot and the pre-tightening module. Specifically, the triangular motion foot moves forward in a single step, and then the piezoelectric ceramic voltage of the pre-tightening module is stimulated to push the slider forward for a certain displacement. The two displacements are accumulated to realize the large-stroke scanning motion mode.

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