Micro pipeline inspection robot with piezoelectric driven flexible spring and control method thereof

Abstract

The present invention provides a micro-pipeline inspection robot with a piezoelectrically driven flexible spring and a control method thereof. The robot comprises a first to a second supporting shell, a flexible spring, and a first to a second stator; wherein six "V"-shaped driving feet are attached to the supporting shell, and a certain frequency sinusoidal voltage signal is applied to the piezoelectric ceramic sheet to excite a specific mode of the "V"-shaped beam, so that the top end point and the pipeline perform contact, extrusion, and separation reciprocating motion; the size of the flexible spring is slightly larger than the inner diameter of the base, and the spring maintains a radial expansion state when inserted into the stator to provide a certain pre-pressure. The present invention has a simple structure, low cost and is easy to maintain, and is suitable for harsh environments such as magnetic field interference and dust; a detector is installed at its front end, and it can be used for internal defect detection of small pipelines that workers cannot reach in industries such as power generation, refrigeration, and aviation.

Description

Technical Field

[0001] The invention relates to the field of pipeline robots, in particular to a micro pipeline detection robot with a piezoelectrically driven flexible spring. Background Art

[0002] Small industrial pipelines are widely used in power generation, refrigeration, aviation, oil refining, chemical industry and other industries. Under the influence of long-term medium corrosion, mechanical vibration and manufacturing defects, cracks will appear in the pipelines, the pipe wall will be thinned or broken; regular inspections to find defects in time and take corresponding repair or plugging measures are important guarantees for the safe operation of the pipeline system. Due to the frequent presence of toxic and harmful media or media residues, coupled with the inaccessibility of manual inspection, the use of robotic technology to inspect, diagnose and maintain small pipelines has become a focus of attention.

[0003] According to the different driving methods, they can be divided into electromagnetic drive, piezoelectric drive, giant magnetostrictive and other types. Considering some special environments such as strong magnetic fields and humid environments, the working performance of electromagnetic drive and giant magnetostrictive robots will be greatly reduced or even unable to work; there are also safety hazards in dusty environments, which may cause dust explosions. Piezoelectric ceramic material is a functional material with the advantages of small size, light weight, simple structure and fast response speed. Piezoelectric driven robots can overcome magnetic field interference, have good operating stability in dusty and humid environments, and have no safety hazards. Therefore, piezoelectric drive is an ideal driving method for micro pipeline robots.

[0004] In the existing similar technologies, the movement is achieved by relying on the static friction between the micro robot support legs or rollers and the pipe wall. The moving distance is affected by the static friction between the support legs and the pipe wall. At the same time, the friction between the support legs or rollers and the pipe wall is serious. Summary of the invention

[0005] In order to solve the problems of the prior art, the present invention provides a micro-pipeline inspection robot with a piezoelectric driven flexible spring, which can adapt to various strong magnetic fields, dust and humid environments; the movement method does not rely on the friction between the supporting legs or rollers and the pipe wall, but utilizes the contact and extrusion between the supporting shell and the pipe wall, and the stator drives the flexible spring to realize the forward and backward movement of the robot, thereby improving the movement rate of the robot; at the same time, the flexible spring serves as the body of the robot, and the robot can adapt to various curved pipes.

[0006] The present invention provides a micro-pipeline inspection robot with a piezoelectrically driven flexible spring, comprising two supporting shells with stators fixed inside, a flexible spring passing through the two stators to connect the two supporting shells, and the flexible spring and the stator are in a compressed pre-tightened state; a plurality of driving feet are distributed on the outer edge of the supporting shell, and the driving feet realize contact and separation with the pipeline.

[0007] According to a further improvement, the stator comprises a hollow matrix, and the flexible spring passes through the hollow matrix; two ceramic sheets are installed on each side of the outer surface of the matrix.

[0008] Further improvement, when the same frequency sinusoidal voltage is applied to the piezoelectric ceramic, the mode of the substrate is excited; when the voltage phase difference is When mode, at this time, the end face of the stator will do up and down telescopic movement; phase difference Time mode, at this time, the end face of the stator will do left and right expansion and contraction movement; adjust the phase difference of the voltage hour, and All modes are excited, and a traveling wave will be generated around the stator hole. The points on the surface of the traveling wave will produce an elliptical trajectory, driving the flexible spring to move back and forth through contact friction.

[0009] According to a further improvement, radial expansion of the flexible spring provides a contact preload force between the flexible spring and the stator, and the stator drives the flexible spring to move by friction.

[0010] As a further improvement, the supporting shell is a hollow cylindrical structure, and six driving feet are attached to the outer edge of the supporting shell.

[0011] As a further improvement, the driving foot is V-shaped, with a ceramic sheet attached to each side of the driving foot. When powered on, the telescopic mode of the V-shaped beam of the driving foot is stimulated, and the top end point of the V-shaped beam contacts and disengages from the pipeline. When in contact, it is stuck to the pipeline, and the friction force keeps the supporting shell and the stator stable and motionless; when disengaged, the supporting shell and the stator can move freely.

[0012] The present invention also provides a control method for a micro-pipeline inspection robot with a piezoelectrically driven flexible spring, comprising the following steps:

[0013] 1) The second support shell contacts and clamps the pipeline and remains stationary, while the first support shell does not contact the pipeline. At the same time, the second stator works alone to drive the flexible spring, and the flexible spring drags the first stator and the support as a whole forward;

[0014] 2) The first support shell and the second support shell are simultaneously in contact with the pipeline and are stuck, and the first stator and the second stator work simultaneously to drive the flexible spring to move backward;

[0015] 3) The first support shell is stuck in contact with the pipeline, the second support shell is not in contact with the pipeline, the first stator works alone to drive the flexible spring, and the spring drags the second stator and the support as a whole to move forward;

[0016] 4) Repeat steps 1) to 3) to achieve the overall forward movement of the pipeline inspection robot.

[0017] Further improvement, the stator drives the flexible spring to move by applying a sinusoidal voltage to the piezoelectric ceramic, specifically including: when a sinusoidal voltage of the same frequency is applied to the piezoelectric ceramic, the mode of the substrate is excited; when a voltage phase difference of When mode, at this time, the end face of the stator will do up and down telescopic movement; phase difference Time mode, at this time, the end face of the stator will do left and right expansion and contraction movement; adjust the phase difference of the voltage hour, and All modes are excited, and a traveling wave will be generated around the stator hole. The points on the surface of the traveling wave will produce an elliptical trajectory, driving the flexible spring to move back and forth through contact friction.

[0018] The beneficial effects of the present invention are:

[0019] 1. The movement mode of the present invention does not rely on the friction between the supporting legs or rollers and the pipe wall, but utilizes the contact and extrusion between the supporting shell and the pipe wall, and the stator drives the flexible spring to realize the forward and backward movement of the robot, thereby improving the movement speed of the robot.

[0020] 2. The robot of the present invention has the advantages of simple structure, low cost and easy maintenance, and can adapt to various strong magnetic fields, dust and humid environments.

[0021] 3. The robot of the present invention can be miniaturized, and a detector is installed at its front end, so that it can be used to detect internal defects of small pipes that workers cannot reach in industries such as power generation, refrigeration, and aviation. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 It is an overall schematic diagram of the present invention;

[0024] Figure 2 It is a schematic diagram of the supporting shell;

[0025] Figure 3 is a schematic diagram of the structure of the stator;

[0026] Figure 4 It is a schematic diagram of the installation process of the present invention;

[0027] Figure 5 is the stator working mode;

[0028] Figure 6 This is a schematic diagram of the robot's working principle;

[0029] Figure 7 This is the voltage timing diagram of the stator input.

[0030] Among them: 1 is the first supporting shell; 2 is the second supporting shell; 3 is the flexible spring; 4 is the first stator; 4.1 is the first group of piezoelectric ceramic sheets; 4.2 is the second group of piezoelectric ceramic sheets; 4.3 is the metal matrix; and 5 is the second stator. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] The present invention provides a piezoelectric driven flexible spring micro-pipeline detection robot, the overall structure of which is shown in the figure, and includes a first stator 1, a second stator 2, a flexible spring 3, a first stator 4, and a second stator 5.

[0033] The first to second stators are fixedly installed in the first to second supporting shells, and the flexible spring passes through the two metal stators; the top end of the supporting shell contacts the pipeline and will undergo a reciprocating process of contact-extrusion with the pipeline under piezoelectric drive.

[0034] The supporting shell structure is as follows Figure 2 As shown, it is a hollow cylindrical structure with 6 driving feet attached to the outer edge of the supporting shell.

[0035] The driving foot is V-shaped, with a ceramic sheet attached to each side of the driving foot. When powered on, the telescopic mode of the V-shaped beam of the driving foot is stimulated, and the top end point of the V-shaped beam contacts and disengages from the pipeline. When in contact, it is stuck with the pipeline, and the friction force keeps the supporting shell and the stator stable and motionless; when disengaged, the supporting shell and the stator can move freely.

[0036] The stator structure is as follows Figure 3 As shown, it includes a substrate with a hollow interior, and a flexible spring passes through the hollow interior of the substrate; two ceramic sheets are installed on each side of the outer surface of the substrate.

[0037] like Figure 5 The figure shows the working mode of the stator. When the same frequency sinusoidal voltage is applied to the first group of piezoelectric ceramics 4.1 and the second group of piezoelectric ceramics 4.2, the mode of the substrate 2 is excited. When the same frequency sinusoidal voltage is applied to the piezoelectric ceramics, the mode of the substrate is excited. When the voltage phase difference is When mode, at this time, the end face of the stator will do up and down telescopic movement; phase difference Time mode, at this time, the end face of the stator will do left and right expansion and contraction movement; adjust the phase difference of the voltage hour, and All modes are excited, and a traveling wave will be generated around the stator hole. The points on the surface of the traveling wave will produce an elliptical trajectory, driving the flexible spring to move back and forth through contact friction.

[0038] like Figure 4 In the installation process shown, the stator is designed with ease of installation in mind, and a certain inclination angle is designed at the opening to facilitate the installation of the spring. At the same time, the diameter of the flexible spring is slightly larger than the inner diameter of the stator, and the pre-pressure of the drive is provided through the extrusion of the spring, thereby improving the robot's motion performance.

[0039] like Figure 6 and Figure 7 The working principle of the robot shown in the figure; assuming that the robot is moving to the right at this time, the principle is similar when the movement direction is to the left, and the robot will repeat the four stages Ⅰ to Ⅳ; in stage Ⅰ, the second support shell is in contact with the pipeline and remains motionless, the first support is not in contact with the pipeline, and the second stator works alone to drive the flexible spring, and the spring drags the first stator and the support as a whole forward; in stage Ⅱ, the first to second support shells are in contact with the pipeline and stuck at the same time, and the first to second stators work at the same time to drive the flexible spring to move backward; in stage Ⅲ, the first support shell is in contact with the pipeline and stuck, the second support shell is not in contact with the pipeline, the first stator works alone to drive the flexible spring, and the spring drags the second stator and the support as a whole forward; stage Ⅳ repeats the movement of stage Ⅰ, and the movement displacement is ; Figure 7 It is a timing diagram of the input voltage of the first stator and the second stator.

[0040] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, the above is only a preferred embodiment of the present invention. Since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited to this. Any technician familiar with the technical field is within the technical scope disclosed by the present invention. For ordinary technicians in the technical field, changes or replacements that can be easily thought of should be covered within the protection scope of the present invention without departing from the principle of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A micro pipeline inspection robot with a piezoelectrically driven flexible spring, characterized in that: It includes two supporting shells with stators fixed inside, a flexible spring passes through the two stators to connect the two supporting shells, the flexible spring and the stator are in a compressed pre-tightened state, and the stator is driven by piezoelectricity; a plurality of driving feet are distributed on the outer edge of the supporting shell, and the driving feet realize contact and separation with the pipeline.

2. The micro pipeline inspection robot with piezoelectric driven flexible spring according to claim 1 is characterized in that: The stator comprises a hollow matrix, and a flexible spring passes through the hollow matrix; two ceramic sheets are installed on each side of the outer surface of the matrix.

3. The micro pipeline inspection robot with piezoelectric driven flexible spring according to claim 2 is characterized in that: When a sinusoidal voltage of the same frequency is applied to the piezoelectric ceramic, the mode of the substrate is excited; when a voltage with a phase difference of When mode, at this time, the end face of the stator will do up and down telescopic movement; phase difference Time mode, at this time, the end face of the stator will do left and right expansion and contraction movement; adjust the phase difference of the voltage hour, and All modes are excited, and a traveling wave will be generated around the stator hole. The points on the surface of the traveling wave will produce an elliptical trajectory, driving the flexible spring to move back and forth through contact friction.

4. The micro pipeline inspection robot with piezoelectric driven flexible spring according to claim 1 or 2, characterized in that: The radial expansion of the flexible spring provides a contact preload force between the flexible spring and the stator, and the stator drives the flexible spring to move by friction.

5. The micro pipeline inspection robot with piezoelectric driven flexible spring according to claim 1 is characterized in that: The supporting shell is a hollow cylindrical structure, and 6 driving feet are attached to the outer edge of the supporting shell.

6. The micro pipeline inspection robot with piezoelectric driven flexible spring according to claim 1 or 5, characterized in that: The driving foot is V-shaped, with a ceramic sheet attached to each side of the driving foot. When powered on, the telescopic mode of the V-shaped beam of the driving foot is stimulated, and the top end point of the V-shaped beam contacts and disengages from the pipeline. When in contact, it is stuck with the pipeline, and the friction force keeps the supporting shell and the stator stable and motionless; when disengaged, the supporting shell and the stator can move freely.

7. A control method for a micro-pipeline inspection robot with a piezoelectrically driven flexible spring, characterized in that The following steps are involved: 1) The second support shell contacts and clamps the pipeline and remains stationary, while the first support shell does not contact the pipeline. At the same time, the second stator works alone to drive the flexible spring, and the flexible spring drags the first stator and the support as a whole forward; 2) The first support shell and the second support shell are simultaneously in contact with the pipeline and are stuck, and the first stator and the second stator work simultaneously to drive the flexible spring to move backward; 3) The first support shell is stuck in contact with the pipeline, the second support shell is not in contact with the pipeline, the first stator works alone to drive the flexible spring, and the spring drags the second stator and the support as a whole to move forward; 4) Repeat steps 1) to 3) to achieve the overall forward movement of the pipeline inspection robot.

8. The control method of the micro-pipeline inspection robot with piezoelectrically driven flexible spring according to claim 7, characterized in that: The stator drives the flexible spring to move by applying a sinusoidal voltage to the piezoelectric ceramic, specifically including: when a sinusoidal voltage of the same frequency is applied to the piezoelectric ceramic, the mode of the substrate is excited; when a voltage phase difference of When mode, at this time, the end face of the stator will do up and down telescopic movement; phase difference Time mode, at this time, the end face of the stator will do left and right expansion and contraction movement; adjust the phase difference of the voltage hour, and All modes are excited, and a traveling wave will be generated around the stator hole. The points on the surface of the traveling wave will produce an elliptical trajectory, driving the flexible spring to move back and forth through contact friction.

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