Piezoelectric inertial crawling robot with extremely simple structure and large load ratio and driving method thereof

Abstract

A piezoelectric inertial crawling robot with a large load-to-weight ratio and a driving method thereof with an extremely simple structure. The robot provides direct power for the robot's linear motion and rotational motion by arranging two piezoelectric inertial impact drive mechanisms on one side as the main power source. The robot has an extremely simple structure, no energy loss and redundant structure, so that it can achieve high-speed linear and rotational motion in a plane. At the same time, the load weight is designed as an inertial mass, so that the load is converted into power, which significantly improves the robot's load capacity. The present invention also provides an actuation method. By applying voltage to each piezoelectric stack, the two piezoelectric inertial impact drive mechanisms generate inertial force, and then by adjusting the input voltage of each piezoelectric stack, the size and direction of the inertial force generated by each drive mechanism can be changed to achieve linear motion and rotational motion in a plane. The two cooperate to achieve large-scale rapid crawling in any direction in the plane.

Description

Technical Field

[0001] The present invention belongs to the technical field of crawling robots, and in particular relates to a piezoelectric inertial crawling robot with a very simple structure and a large load ratio, and a driving method thereof. Background Art

[0002] With the continuous development of science and technology, the demand for micro-robots in various fields such as national defense, aerospace, agriculture, communications, pipeline transportation and other special environments has increased significantly. For example, local area firefighting and emergency repair tasks in space stations are often extremely narrow and difficult to access, which puts higher requirements on micro-robots. Among them, micro-crawling robots have received a lot of attention due to their simple structure and simple driving method. They have been widely used in pipeline detection and other aspects, and are playing an increasingly important role. However, most micro-crawling robots are slow and have low flexibility. Increasing the load will only increase frictional resistance, resulting in large energy loss and low load-bearing capacity. At the same time, the structure is complex and it is difficult to adapt to zero-gravity environments such as space stations, and cannot meet the needs of emergency repairs and other tasks under sudden situations.

[0003] Therefore, there is an urgent need to develop a new type of micro robot with a compact design, simple structure, high flexibility, large load-to-weight ratio, suitable for zero-gravity environment, able to enter the narrow areas inside the space station or satellite warehouse for rapid inspection, emergency fire fighting or structural repair, and perform complex tasks in extreme environments. Summary of the invention

[0004] In order to overcome the technical problems existing in the above-mentioned prior art, the present invention aims to provide a piezoelectric inertial crawling robot with a very simple structure and a large load-to-weight ratio and a driving method thereof. The robot is a micro robot. By arranging four piezoelectric drive mechanisms on both sides of the central body of the robot as the main power source, it can achieve high-speed linear and rotational motion in the plane, and has the characteristics of high speed, high energy efficiency, large load-to-weight ratio, high driving accuracy and fast response.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A piezoelectric inertial crawling robot with a minimalist structure and a large load-to-weight ratio comprises a chassis 1, a base 3 is installed at the bottom of the chassis 1, and two piezoelectric inertial impact drive mechanisms are installed in parallel on one side of the chassis 1, which can accurately control the robot to complete linear motion and rotational motion, and realize high-precision displacement output in all directions in the plane through synthetic motion; the first piezoelectric inertial impact drive mechanism is composed of a first rhombus ring 2-1 and a first piezoelectric stack 4-1 embedded in the first rhombus ring 2-1, and the second piezoelectric inertial impact drive mechanism is composed of a second rhombus ring 2-2 and a second piezoelectric stack 4-2 embedded in the second rhombus ring 2-2, and a first loading platform 5-1 and a second loading platform 5-2 fixedly connected to the chassis 1 are installed above the first piezoelectric inertial impact drive mechanism and the second piezoelectric inertial impact drive mechanism, respectively, and a magnetic support foot 6 is bonded to the bottom of the base 3.

[0007] The legs of the base 3 are arranged in an "H" shape along the surface, and a magnetic foot 6 is bonded to the bottom of the outer end of each leg, so that the robot can adsorb a specific surface in a zero-gravity environment and achieve a large range of crawling in the plane.

[0008] The first loading platform 5-1 and the second loading platform 5-2 are in the shape of a rectangle, so that the two loading platforms form a square as a whole, which can evenly distribute the load mass and keep the robot stable when moving, and is not prone to tilting and losing balance.

[0009] The first piezoelectric stack 4-1 and the second piezoelectric stack 4-2 are made of piezoelectric ceramics. Piezoelectric ceramics have excellent properties such as high temperature resistance, corrosion resistance and oxidation resistance. They can work for a long time in harsh environments and quickly deform when the input voltage changes, thereby enabling the drive mechanism to achieve rapid response and high-precision control.

[0010] The driving method of the piezoelectric inertial crawling robot with a very simple structure and a large load ratio is as follows: in the initial state, the two piezoelectric stacks in the robot are both in a power-off state, and different periodic voltages are applied to the two piezoelectric stacks to achieve high-precision displacement output in all directions within the robot plane. If the two piezoelectric stacks are embedded in the corresponding diamond rings along the X-axis direction, when the robot moves along the positive direction of the Y-axis, the driving method is as follows:

[0011] Step 1: When no voltage is applied to the first piezoelectric inertial impact drive mechanism, the first piezoelectric stack 4 - 1 is not charged, and the first piezoelectric stack 4 - 1 is in the shortest state;

[0012] Step 2: Apply a sawtooth voltage signal with an amplitude of U1 and a symmetry of 100% to the first piezoelectric inertial impact drive mechanism. As the voltage increases, the first piezoelectric stack 4-1 slowly extends, causing the first rhombus ring 2-1 to shorten along the positive direction of the Y axis. Due to the friction of the ground, the chassis 1 does not move, while the stage 5 moves along the positive direction of the Y axis as the first rhombus ring 2-1 shortens.

[0013] Step 3: The applied sawtooth voltage drops sharply to 0 at time t1, at which time the first piezoelectric stack 4-1 suddenly loses power and quickly shrinks to the same minimum length as in step 1, and the first rhombus ring 2-1 expands rapidly along the Y-axis direction. At this time, due to the effect of inertia, the inertial force F1 generated by the first stage 5-1 along the positive direction of the Y-axis is greater than the friction force of the ground, driving the chassis to move along the positive direction of the Y-axis by a step length S; when a sawtooth voltage signal with an amplitude of U1 and a symmetry of 100% is applied to the second piezoelectric inertial impact drive mechanism, the motion state is the same as that of the first piezoelectric inertial impact drive mechanism, and the generated inertial force is F2; ​​by repeating the above steps, a large working stroke can be obtained;

[0014] By changing the voltage amplitude and symmetry of the sawtooth voltage signal and repeating the above steps, the continuous movement of the micro robot in a certain direction can be achieved;

[0015] When rotational motion is required, a sawtooth voltage signal with an amplitude of U1 and a symmetry of 100% is applied to the first piezoelectric inertial impact drive mechanism, and a sawtooth voltage signal with an amplitude of U2 and a symmetry of 0% is applied to the second piezoelectric inertial impact drive mechanism. At this time, the inertial forces generated by the two piezoelectric inertial impact drive mechanisms are F1 and F2' respectively. The inertial force F1 generates a clockwise torque M1 on the center point O of the robot, and the inertial force F2' generates a clockwise torque M2 on the center point O of the robot, causing the robot to rotate at high speed. By controlling the amplitude and symmetry of the sawtooth voltage signals applied by the two piezoelectric inertial impact drive mechanisms, the rotation angle of the robot in the plane can be controlled, and the rotational motion is coordinated with the linear motion to complete a large range of high-speed crawling motion in all directions in the plane.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] 1. The crawling robot of the present invention can change the magnitude and direction of the inertial force generated by the two stages by changing the sawtooth wave signal of the piezoelectric stack, and can achieve high-speed rotation and linear motion in the plane. It has high flexibility and stability. The combination of the two can help the micro robot achieve a large range of crawling motion in any direction in the plane.

[0018] 2. The crawling robot of the present invention is provided with two piezoelectric inertial impact drive mechanisms to provide direct power for the robot's linear motion and rotational motion, without energy loss and redundant structure, which greatly improves the efficiency of the robot, and can achieve high-speed motion while reducing energy loss;

[0019] 3. Different from the current situation that increasing the load of traditional inertial driven robots will only increase the friction resistance and the crawling speed will decrease with the increase of the load, the present invention fixes the load in the square area above the loading platform. Increasing the load also increases the inertial driving force. Within a large load range, the crawling speed of the robot will remain unchanged or even increase with the increase of the load, thereby having a larger load capacity and significantly improving the load ratio of the micro robot;

[0020] 4. Compared with traditional micro robots, the robot of the present invention uses magnetic feet to enable the robot to adsorb specific surfaces in a zero-gravity environment and achieve large-scale crawling in a plane. It also has the characteristics of simple and compact structure, light weight, easy to carry, and small size, which expands the application scenarios of the robot;

[0021] 5. The present invention adopts piezoelectric ceramics as the driving unit and adopts an inertial impact driving method, and has the characteristics of large stroke, high precision, and bidirectional movement. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the assembly of the robot device of the present invention.

[0023] Figure 2 Schematic diagram of the explosion of the robot device of the present invention.

[0024] Figure 3 It is a side plan view of the robot device of the present invention.

[0025] Figure 4 This is a schematic diagram of the actuation principle of the robot device of the present invention.

[0026] Figure 5a and Figure 5b They are schematic diagrams of the linear movement of the robot device of the present invention along the positive directions of the Y-axis and the X-axis respectively.

[0027] Figure 6 It is a schematic diagram of the robot of the present invention rotating in a clockwise direction.

[0028] Figure 7 This is a timing diagram of the driving voltage when the robot device of the present invention moves linearly along the Y-axis direction. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0030] like Figure 1 , Figure 2 and Figure 3As shown, the present invention describes a piezoelectric inertial crawling robot with a minimalist structure and a large load-to-weight ratio, comprising a chassis 1, a base 3 is installed at the bottom of the chassis 1, and two piezoelectric inertial impact drive mechanisms are installed in parallel on one side of the chassis 1, which can accurately control the robot to complete linear motion and rotational motion, and realize high-precision displacement output in all directions in the plane through synthetic motion; the first piezoelectric inertial impact drive mechanism is composed of a first rhombus ring 2-1 and a first piezoelectric stack 4-1 embedded in the first rhombus ring 2-1, and the second piezoelectric inertial impact drive mechanism is composed of a second rhombus ring 2-2 and a second piezoelectric stack 4-2 embedded in the second rhombus ring 2-2, and a first loading platform 5-1 and a second loading platform 5-2 fixedly connected to the chassis 1 are installed above the first piezoelectric inertial impact drive mechanism and the second piezoelectric inertial impact drive mechanism, respectively, and the magnetic support feet 6 are bonded to the bottom of the base 3.

[0031] like Figure 7 As shown, the specific input signal amplitude is U1, the symmetry is 100% of the sawtooth wave signal and the amplitude is U2, the symmetry is 0% of the sawtooth wave signal. In the initial state, the two piezoelectric stacks in the robot are in the power-off state. By applying different periodic voltages to the two piezoelectric stacks, the high-precision displacement output in all directions of the robot plane is achieved. If the two piezoelectric stacks are embedded in the corresponding diamond rings along the X-axis direction, when the robot moves along the positive direction of the Y-axis, its driving method is as follows Figure 4 As shown, the details are as follows:

[0032] Step 1: When no voltage is applied to the first piezoelectric inertial impact drive mechanism, the first piezoelectric stack 4 - 1 is not charged, and the first piezoelectric stack 4 - 1 is in the shortest state;

[0033] Step 2: Apply a sawtooth voltage signal with an amplitude of U1 and a symmetry of 100% to the first piezoelectric inertial impact drive mechanism. As the voltage increases, the first piezoelectric stack 4-1 slowly extends, causing the first rhombus ring 2-1 to shorten along the positive direction of the Y axis (e.g. Figure 5a Due to the friction of the ground, the chassis 1 does not move, while the loading platform 5 moves along the positive direction of the Y axis as the first rhombus ring 2-1 shortens;

[0034] Step 3: The applied sawtooth voltage drops sharply to 0 at time t1. At this time, the first piezoelectric stack 4-1 suddenly loses power and quickly shrinks to the same minimum length as in step 1. The first diamond ring 2-1 expands rapidly along the Y-axis direction. At this time, due to the inertial effect, the inertial force F1 generated by the first stage 5-1 along the positive direction of the Y-axis is greater than the friction force of the ground, driving the chassis to move along the positive direction of the Y-axis by a step length S as shown in FIG. Figure 5aAs shown; when a sawtooth voltage signal with an amplitude of U1 and a symmetry of 100% is applied to the second piezoelectric inertial impact driving mechanism, the motion state is the same as that of the first piezoelectric inertial impact driving mechanism, and the inertial force generated is F2; ​​by repeating the above steps, a large working stroke can be obtained;

[0035] By changing the voltage amplitude and symmetry of the sawtooth voltage signal and repeating the above steps, the continuous movement of the micro robot in a certain direction can be achieved;

[0036] When it is necessary to realize the movement of the robot along the negative direction of the Y axis, a sawtooth voltage signal with an amplitude of U2 and a symmetry of 0% is applied to the first piezoelectric inertial impact drive mechanism and the second piezoelectric inertial impact drive mechanism, and the first piezoelectric inertial impact drive mechanism and the second piezoelectric inertial impact drive mechanism will generate an inertial force along the negative direction of the Y axis, thereby realizing the movement of the robot along the negative direction of the Y axis;

[0037] If two piezoelectric stacks are embedded in corresponding diamond rings along the Y-axis direction, when the robot moves along the positive direction of the X-axis, its driving method is as follows:

[0038] Step 1: When no voltage is applied to the first piezoelectric inertial impact drive mechanism, the first piezoelectric stack 4 - 1 is not charged, and the first piezoelectric stack 4 - 1 is in the shortest state;

[0039] Step 2: Apply a sawtooth voltage signal with an amplitude of U1 and a symmetry of 100% to the first piezoelectric inertial impact drive mechanism. As the voltage increases, the first piezoelectric stack 4-1 slowly extends, causing the first rhombus ring 2-1 to shorten along the positive direction of the X-axis. Due to the friction of the ground, the chassis 1 does not move, while the stage 5 moves along the positive direction of the X-axis as the first rhombus ring 2-1 shortens.

[0040] Step 3: The applied sawtooth voltage drops sharply to 0 at time t1. At this time, the first piezoelectric stack 4-1 suddenly loses power and quickly shrinks to the same minimum length as in step 1. The first diamond ring 2-1 expands rapidly along the X-axis direction. At this time, due to the inertial effect, the inertial force F3 generated by the first stage 5-1 along the positive direction of the X-axis is greater than the friction force of the ground, driving the chassis to move along the positive direction of the X-axis by a step length S (such as Figure 5b When a sawtooth voltage signal with an amplitude of U1 and a symmetry of 100% is applied to the second piezoelectric inertial impact driving mechanism, the motion state is the same as that of the first piezoelectric inertial impact driving mechanism, and the inertial force generated is F4; by repeating the above steps, a large working stroke can be obtained;

[0041] When it is necessary to realize the movement of the robot along the negative direction of the X-axis, a sawtooth voltage signal with an amplitude of U2 and a symmetry of 0% is applied to the first piezoelectric inertial impact drive mechanism and the second piezoelectric inertial impact drive mechanism, and the first piezoelectric inertial impact drive mechanism and the second piezoelectric inertial impact drive mechanism will generate an inertial force along the negative direction of the X-axis, thereby realizing the movement of the robot along the negative direction of the X-axis;

[0042] When rotational motion is required, a sawtooth voltage signal with an amplitude of U1 and a symmetry of 100% is applied to the first piezoelectric inertial impact driving mechanism, and a sawtooth voltage signal with an amplitude of U2 and a symmetry of 0% is applied to the second piezoelectric inertial impact driving mechanism. At this time, the inertial forces generated by the two driving mechanisms are F1 and F2' respectively (such as Figure 6 As shown in the figure, the inertial force F1 generates a clockwise torque M1 on the center point O of the robot, and the inertial force F2' generates a clockwise torque M2 on the center point O of the robot. The torque causes the robot to rotate at high speed. The rotation angle of the robot in the plane can be regulated by controlling the amplitude and symmetry of the sawtooth voltage signal applied by the two piezoelectric inertial impact drive mechanisms. The rotation motion is coordinated with the linear motion to complete a large range of high-speed crawling motion in all directions in the plane.

[0043] After the robot has been working for a long time, the surfaces of the piezoelectric stack and the diamond ring in contact will experience interface wear and the actuation capacity will decrease. At this time, by applying a larger voltage, the diamond ring will be stretched more to maintain the normal operation of the robot.

[0044] The robot of the present invention has two piezoelectric inertial impact drive mechanisms installed in parallel on one side to cooperate with each other to achieve large-range crawling in a plane. At the same time, the load weight is designed to be inertial mass, so that the load is converted into power, which significantly improves the load capacity of the robot. The present invention also provides a driving method. By applying voltage to each piezoelectric stack, the two piezoelectric stacks can generate inertial forces of different magnitudes and directions, and then by adjusting the input voltage amplitude of each piezoelectric stack, the inertial force generated by each drive mechanism can be changed, the magnitude and direction of the resultant force acting on the robot in the plane can be adjusted, and the linear motion is coordinated with the rotational motion, thereby achieving crawling in any direction in the plane.

Claims

1. A piezoelectric inertial crawling robot with a very simple structure and a large load ratio, characterized in that: The invention comprises a chassis (1), wherein a base (3) is installed at the bottom of the chassis (1); and two piezoelectric inertial impact drive mechanisms are installed in parallel on one side of the chassis (1), which can accurately control the robot to complete linear motion and rotational motion, and realize high-precision displacement output in all directions in a plane through synthetic motion; the first piezoelectric inertial impact drive mechanism is composed of a first rhombus ring (2-1) and a first piezoelectric stack (4-1) embedded in the first rhombus ring (2-1); and the second piezoelectric inertial impact drive mechanism is composed of a second rhombus ring (2-2) and a second piezoelectric stack (4-2) embedded in the second rhombus ring (2-2). A first loading platform (5-1) and a second loading platform (5-2) are respectively mounted above the first piezoelectric inertial impact drive mechanism and the second piezoelectric inertial impact drive mechanism; the first loading platform (5-1) and the second loading platform (5-2) are separated, i.e., they are not in contact with each other; the chassis (1) is connected to the first loading platform (5-1) and the second loading platform (5-2) respectively through the first piezoelectric inertial impact drive mechanism and the second piezoelectric inertial impact drive mechanism, but the chassis (1) is not in contact with the first loading platform (5-1) and the second loading platform (5-2); and the magnetic support feet (6) are bonded to the bottom of the base (3).

2. According to claim 1, a piezoelectric inertial crawling robot with a very simple structure and a large load ratio, characterized in that: The legs of the base (3) are arranged in an "H" shape along the inner surface, and a magnetic support foot (6) is bonded to the bottom of the outer end of each leg.

3. The piezoelectric inertial crawling robot with a very simple structure and a large load ratio according to claim 1, characterized in that: The first loading platform (5-1) and the second loading platform (5-2) are rectangular, so that the two loading platforms form a square as a whole.

4. The piezoelectric inertial crawling robot with a very simple structure and a large load ratio according to claim 1, characterized in that: The first piezoelectric stack (4-1) and the second piezoelectric stack (4-2) are made of piezoelectric ceramics.

5. A driving method for a piezoelectric inertial crawling robot with a very simple structure and a large load ratio as claimed in any one of claims 1 to 4, characterized in that: In the initial state, the two piezoelectric stacks in the robot are both in the power-off state. By applying different periodic voltages to the two piezoelectric stacks, high-precision displacement output in all directions within the robot plane is achieved. If the two piezoelectric stacks are embedded in the corresponding diamond rings along the X-axis direction, when the robot moves along the positive direction of the Y-axis, its driving method is as follows: Step 1: when no voltage is applied to the first piezoelectric inertial impact drive mechanism, the first piezoelectric stack (4-1) is not charged, and at this time the first piezoelectric stack (4-1) is in the shortest state; Step 2: applying a sawtooth voltage signal with an amplitude of U1 and a symmetry of 100% to the first piezoelectric inertial impact drive mechanism, and as the voltage increases, the first piezoelectric stack (4-1) slowly extends, causing the first rhombus ring (2-1) to shorten along the positive direction of the Y axis; due to the friction of the ground, the chassis (1) does not move, while the first loading platform (5-1) moves along the positive direction of the Y axis as the first rhombus ring (2-1) shortens; Step 3: The applied sawtooth voltage drops sharply to 0 at time t1, at which time the first piezoelectric stack (4-1) suddenly loses power and quickly shrinks to the same minimum length as in step 1, and the first rhombus ring (2-1) expands rapidly along the Y-axis direction. At this time, due to the effect of inertia, the inertial force F1 generated by the first stage (5-1) along the positive direction of the Y-axis is greater than the friction force of the ground, driving the chassis to move along the positive direction of the Y-axis by a step length S; when a sawtooth voltage signal with an amplitude of U1 and a symmetry of 100% is applied to the second piezoelectric inertial impact drive mechanism, the motion state is the same as that of the first piezoelectric inertial impact drive mechanism, and the inertial force generated is F2; ​​by repeating the above steps, a large working stroke can be obtained; By changing the voltage amplitude and symmetry of the sawtooth voltage signal and repeating the above steps, the continuous movement of the micro robot along a certain direction can be achieved; When rotational motion is required, a sawtooth voltage signal with an amplitude of U1 and a symmetry of 100% is applied to the first piezoelectric inertial impact drive mechanism, and a sawtooth voltage signal with an amplitude of U2 and a symmetry of 0% is applied to the second piezoelectric inertial impact drive mechanism. At this time, the inertial forces generated by the two piezoelectric inertial impact drive mechanisms are F1 and F2' respectively. The inertial force F1 generates a clockwise torque M1 on the center point O of the robot, and the inertial force F2' generates a clockwise torque M2 on the center point O of the robot, causing the robot to rotate at high speed. By controlling the amplitude and symmetry of the sawtooth voltage signals applied by the two piezoelectric inertial impact drive mechanisms, the rotation angle of the robot in the plane can be controlled, and the rotational motion is coordinated with the linear motion to complete a large range of high-speed crawling motion in all directions in the plane.

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