A piezoelectric inertial impact type micro crawling robot with large load-to-weight ratio and a driving method thereof

Abstract

A large load-to-weight ratio piezoelectric inertial impact type micro-crawling robot and a driving method thereof. The robot realizes large-range crawling in a plane by cooperating with piezoelectric inertial impact type driving mechanisms arranged in three directions at equal angles of 120° in the plane. At the same time, the load weight is designed as 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 three piezoelectric stacks can generate inertial forces in three directions at equal angles of 120°, and then by adjusting the input voltage amplitude of each piezoelectric stack, the inertial forces generated by each driving mechanism can be changed. Finally, through the synthetic effect of the force, the size and direction of the resultant force on the robot in the plane can be adjusted, thereby realizing crawling in any direction in the plane.

Description

Technical Field

[0001] The invention belongs to the technical field of micro-crawling robots, and in particular relates to a large load-to-weight ratio piezoelectric inertial impact type micro-crawling robot 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 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, the increase in weight of most micro crawling robots will only increase frictional resistance, resulting in low load capacity, slow speed, low flexibility, and complex structure, making it difficult to adapt to zero-gravity environments such as space stations.

[0003] Therefore, there is an urgent need to develop a new type of micro robot with a compact design, a large load-to-weight ratio, suitable for zero-gravity environments, able to enter small areas inside space stations or satellite warehouses for inspections, emergency firefighting or structural repairs, 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 large load-to-weight ratio piezoelectric inertial impact type micro-crawling robot and a driving method. The robot is a micro-robot. By arranging a piezoelectric inertial impact drive mechanism in three directions with equal angles of 120° in the plane, it can achieve a large range of crawling in the plane. It has the characteristics of fast speed, 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 high load-to-weight ratio piezoelectric inertial impact micro-crawling robot comprises a disc 1, a base 3 is installed at the bottom of the disc 1, and three piezoelectric inertial impact drive mechanisms are installed on the top, which are arranged in three directions at equal angles of 120° in a plane, and can accurately control the displacement of the robot in three directions, and achieve high-precision displacement output in each direction 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 The second rhombus ring 2-2 is composed of a second piezoelectric stack 4-2 embedded in the second rhombus ring 2-2, and the third piezoelectric inertial impact drive mechanism is composed of a third rhombus ring 2-3 and a third piezoelectric stack 4-3 embedded in the third rhombus ring 2-3. A first stage 5-1, a second stage 5-2 and a third stage 5-3 fixedly connected to the disc 1 are respectively installed above the first piezoelectric inertial impact drive mechanism, the second piezoelectric inertial impact drive mechanism and the third piezoelectric inertial impact drive mechanism, and the magnetic support feet 6 are bonded to the bottom of the base 3.

[0007] The legs of the base 3 are arranged in three directions at equal angles of 120° in the plane, and a magnetic foot 6 is bonded to the bottom of the outer end of each leg, so that the robot can adsorb specific surfaces in a zero-gravity environment and achieve large-scale crawling in the plane.

[0008] The first loading platform 5-1, the second loading platform 5-2 and the third loading platform 5-3 have a central angle of 120°, so that the three loading platforms as a whole form a circle. The symmetrical arrangement can evenly distribute the load mass, so that the robot can remain stable when moving and is not prone to tilting or losing balance.

[0009] The first piezoelectric stack 4-1, the second piezoelectric stack 4-2 and the third piezoelectric stack 4-3 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 impact type micro crawling robot with a large load ratio is as follows: in the initial state, the three piezoelectric stacks in the robot are all in a power-off state. By applying different periodic voltages to the three piezoelectric stacks, high-precision displacement output in all directions within the robot plane is achieved. When the robot moves along the negative direction of the X-axis, the actuation 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 X-axis. Due to the friction of the ground, the disk 1 does not move, while the stage 5 moves along the negative direction of the X-axis as the first rhombus ring 2-1 lengthens.

[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 X-axis direction. At this time, due to the effect of inertia, the inertial force F1 generated by the first stage 5-1 along the negative direction of the X-axis is greater than the friction force of the ground, driving the disk to move along the negative direction of the X-axis by a step length S; by repeating the above steps, a large working stroke can be obtained;

[0014] At the same time, when sawtooth voltage signals with amplitudes of U2 and U3 and symmetry of 0% are applied to the second piezoelectric stack 4-2 and the third piezoelectric stack 4-3, the second piezoelectric stack 4-2 and the third piezoelectric stack 4-3 will generate inertial force F2 and inertial force F3 respectively. The inertial force F2' and the inertial force F3' will become the inertial force F4 along the positive direction of the X-axis after the force synthesis. At this time, driven by the inertial forces F1 and F4, the robot completes the negative movement along the X-axis.

[0015] Repeating the above steps can realize the continuous movement of the micro robot in a certain direction;

[0016] When it is necessary to achieve displacement output in other directions, the voltage amplitude and symmetry applied to the first piezoelectric stack 4-1, the second piezoelectric stack 4-2 and the third piezoelectric stack 4-3 are changed, so that the three piezoelectric inertial impact drive mechanisms generate forces of different magnitudes in three directions. Through the synthesis of forces, the direction and magnitude of the resultant force acting on the robot are changed, thereby achieving displacement translation in different directions.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] 1. Different from the current situation that the increase of load in traditional inertial driven robots will only increase friction resistance and the crawling speed will decrease with the increase of load, the present invention fixes the load in the fan-shaped area above the stage, and the inertial driving force generated by the stage during the operation also increases with the increase of load. Within a wide load range, the crawling speed of the robot will remain unchanged or even increase with the increase of load, thereby having a greater load capacity and significantly improving the load ratio of the micro robot;

[0019] 2. The microrobot of the present invention can change the magnitude and direction of the inertial force generated by the three stages by changing the sawtooth wave signal of the piezoelectric stack, thereby utilizing the synthetic effect of the force to help the microrobot achieve displacement movement in any direction within the plane, and has high flexibility and stability;

[0020] 3. 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] 4. The present invention adopts piezoelectric ceramic piezoelectric stack as the driving unit and adopts 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 respectively a schematic diagram of the movement of the robot device of the present invention along the negative direction of the X-axis and a schematic diagram of the synthesis of the force.

[0027] Figure 6 This is a timing diagram of the driving voltage when the robot of the present invention moves along the X-axis direction. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0029] like Figure 1 , Figure 2 and Figure 3As shown, a large load-to-weight ratio piezoelectric inertial impact micro-crawling robot described in the present invention comprises a disc 1, a base 3 is installed at the bottom of the disc 1, and three piezoelectric inertial impact drive mechanisms are installed on the upper part, which are arranged in three directions at equal angles of 120° in the plane, and can accurately control the displacement of the robot in three directions, and realize high-precision displacement output in each direction 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 first rhombus ring 2-1 and a first piezoelectric stack 4-1 embedded in the first rhombus ring 2-1. The driving 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 the third piezoelectric inertial impact driving mechanism is composed of a third rhombus ring 2-3 and a third piezoelectric stack 4-3 embedded in the third rhombus ring 2-3. A first loading platform 5-1, a second loading platform 5-2 and a third loading platform 5-3 fixedly connected to the disc 1 are respectively installed above the first piezoelectric inertial impact driving mechanism, the second piezoelectric inertial impact driving mechanism and the third piezoelectric inertial impact driving mechanism, and the magnetic support feet 6 are bonded to the bottom of the base 3.

[0030] like Figure 6 As shown, the specific input signal amplitudes are U1, U2 and U3, and the symmetry is a sawtooth wave signal of 100% and 0%. In the initial state, the three piezoelectric stacks in the robot are all in a power-off state. By applying different periodic voltages to the three piezoelectric stacks, high-precision displacement output in all directions within the robot plane is achieved. When the robot moves along the negative direction of the X-axis, its driving method is as follows Figure 4 As shown, the details are as follows:

[0031] 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.

[0032] 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 (e.g. Figure 5a Due to the friction of the ground, the disk 1 does not move, while the stage 5 moves along the negative direction of the X-axis as the first rhombus ring 2-1 extends.

[0033] 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 F1 generated by the first stage 5-1 along the negative direction of the X-axis is greater than the friction force of the ground, driving the disk to move along the negative direction of the X-axis by a step length S (such as Figure 5aBy repeating the above steps, a large working stroke can be obtained;

[0034] At the same time, when sawtooth voltage signals with amplitudes of U2 and U3 and 0% symmetry are applied to the second piezoelectric stack 4-2 and the third piezoelectric stack 4-3, the second piezoelectric stack 4-2 and the third piezoelectric stack 4-3 will generate inertial force F2 and inertial force F3 respectively. The inertial force F2' and the inertial force F3' are synthesized to become the inertial force F4 along the positive direction of the X-axis (such as Figure 5b As shown in the figure, at this time, driven by the inertial forces F1 and F4, the robot completes negative motion along the X-axis.

[0035] Repeating the above steps can realize the continuous movement of the micro robot in a certain direction;

[0036] When it is necessary to achieve displacement output in other directions, the voltage amplitude and symmetry applied to the first piezoelectric stack 4-1, the second piezoelectric stack 4-2 and the third piezoelectric stack 4-3 are changed, so that the three piezoelectric inertial impact drive mechanisms generate forces of different magnitudes in three directions. Through the synthesis of forces, the direction and magnitude of the resultant force acting on the robot are changed, thereby achieving displacement translation in different directions.

[0037] 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.

[0038] The robot of the present invention realizes large-range crawling in a plane by cooperating with each other through piezoelectric inertial impact drive mechanisms arranged in three directions at equal angles of 120° in the 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 three piezoelectric stacks can generate inertial forces in three directions at equal angles of 120°, and then the inertial forces generated by each driving mechanism can be changed by adjusting the input voltage amplitude of each piezoelectric stack. Finally, through the synthetic effect of force, the size and direction of the resultant force acting on the robot in the plane can be adjusted, thereby realizing crawling in any direction in the plane.

Claims

1. A piezoelectric inertial impact micro crawling robot with a large load ratio, characterized in that: The invention comprises a disk (1), wherein a base (3) is installed at the bottom of the disk (1), and three piezoelectric inertial impact drive mechanisms are installed at the top, which are arranged in three directions at equal angles of 120° in a plane, and can accurately control the displacement of the robot in three directions, and realize high-precision displacement output in each direction 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), 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 the third 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). The three piezoelectric inertial impact drive mechanisms are composed of a third rhombus ring (2-3) and a third piezoelectric stack (4-3) embedded in the third rhombus ring (2-3). A first loading platform (5-1), a second loading platform (5-2) and a third loading platform (5-3) fixedly connected to the disc (1) are respectively installed above the first piezoelectric inertial impact drive mechanism, the second piezoelectric inertial impact drive mechanism and the third piezoelectric inertial impact drive mechanism. The first loading platform (5-1), the second loading platform (5-2) and the third loading platform (5-3) are separated, that is, the three are not in contact with each other, and the magnetic support feet (6) are bonded to the bottom of the base (3).

2. The high load-to-weight ratio piezoelectric inertial impact micro-crawling robot according to claim 1, characterized in that: The legs of the base (3) are arranged in three directions at equal angles of 120° in the plane, and a magnetic support foot (6) is bonded to the bottom of the outer end of each leg.

3. The high load-to-weight ratio piezoelectric inertial impact micro-crawling robot according to claim 1, characterized in that: The first loading platform (5-1), the second loading platform (5-2) and the third loading platform (5-3) have a central angle of 120°, so that the three loading platforms form a circle as a whole.

4. The high load-to-weight ratio piezoelectric inertial impact micro-crawling robot according to claim 1, characterized in that: The first piezoelectric stack (4-1), the second piezoelectric stack (4-2) and the third piezoelectric stack (4-3) are made of piezoelectric ceramics.

5. The driving method of a high load-to-weight ratio piezoelectric inertial impact micro-crawling robot according to any one of claims 1 to 4, characterized in that: In the initial state, the three piezoelectric stacks in the robot are all in the power-off state. By applying different periodic voltages to the three piezoelectric stacks, high-precision displacement output in all directions within the robot plane is achieved. When the robot moves along the negative direction of the X-axis, its actuation 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 X-axis; due to the friction force of the ground, the disk (1) does not move at all, while the stage (5) moves along the negative direction of the X-axis as the first rhombus ring (2-1) extends; Step 3: The applied sawtooth wave 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 X-axis direction. At this time, due to the effect of inertia, the inertial force F1 generated by the first stage (5-1) along the negative direction of the X-axis is greater than the friction force of the ground, driving the disk to move along the negative direction of the X-axis by a step length S; by repeating the above steps, a large working stroke can be obtained; At the same time, when sawtooth voltage signals with amplitudes of U2 and U3 and a symmetry of 0% are applied to the second piezoelectric stack (4-2) and the third piezoelectric stack (4-3), the second piezoelectric stack (4-2) and the third piezoelectric stack (4-3) will generate inertial force F2 and inertial force F3 respectively. After the inertial force F2' and the inertial force F3' are synthesized, they become inertial force F4 along the positive direction of the X-axis. At this time, driven by the inertial forces F1 and F4, the robot completes negative movement along the X-axis. Repeating the above steps can realize the continuous movement of the micro robot in a certain direction; When it is necessary to realize displacement output in other directions, the voltage amplitude and symmetry applied to the first piezoelectric stack (4-1), the second piezoelectric stack (4-2) and the third piezoelectric stack (4-3) are changed so that the three piezoelectric inertial impact drive mechanisms generate forces of different magnitudes in three directions. By synthesizing the forces, the direction and magnitude of the resultant force acting on the robot are changed, thereby realizing displacement translation in different directions.

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