Self-powered accelerometer based on planetary gear structure frictional nanogenerator

Abstract

This invention relates to a self-driven accelerometer based on a planetary gear structure triboelectric nanogenerator. The invention includes a planetary gear structure and a sawtooth-shaped triboelectric nanogenerator. The input end of the planetary gear structure is connected to the axle of a car tire. The sawtooth-shaped triboelectric nanogenerator comprises an upper metal electrode layer, an upper friction layer, and a lower metal electrode layer. When the tire rotates, it drives the slider of the planetary gear structure to reciprocate linearly on the outer casing support. The sawtooth-shaped triboelectric nanogenerator generates triboelectric and induced charges, thereby generating voltage and current. The magnitude of the voltage between the upper and lower metal electrodes is detected. Due to the unique structure of this invention, the obtained voltage data is processed, and the peak and trough points of the output voltage can be used to accurately sense the vehicle's acceleration. Compared with existing technologies, this invention improves sensor sensitivity, increases the sensor's measurement range, and achieves self-driving capability, eliminating the need for an external power supply.

Description

Technical Field

[0001] This invention relates to an accelerometer, specifically to a self-driven accelerometer based on a planetary gear structure triboelectric nanogenerator. Background Technology

[0002] In the automotive field, acceleration sensors have broad application prospects. For example, airbags, autonomous driving, and anti-skid systems all require acceleration signals during vehicle operation as data support. However, currently common piezoelectric, piezoresistive, and capacitive acceleration sensors all require external power. Traditional battery power not only pollutes the environment with discarded batteries but also requires regular battery replacement, limiting the sensor's lifespan.

[0003] Triboelectric nanogenerators are based on Maxwell's displacement current theory and utilize the coupling effect of electrostatic induction and triboelectricity to perform both energy harvesting and signal sensing. Because the output electrical signal of triboelectric nanogenerators is highly sensitive to changes in the environment, this technology has significant advantages in the field of self-driven sensing. Currently, this technology is widely used in self-driven sensing applications for acceleration, pressure, temperature, and other parameters. Summary of the Invention

[0004] The purpose of this invention is to solve the power supply problem of existing accelerometers. By using triboelectric nanogenerator technology as the sensing unit, a self-driven accelerometer based on a planetary gear structure triboelectric nanogenerator is invented, which can achieve accurate sensing of vehicle acceleration without the need for external power supply.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A self-driven accelerometer based on a planetary gear structure triboelectric nanogenerator is characterized by comprising a planetary gear structure A1 and a sawtooth triboelectric nanogenerator A2, wherein the input end of the planetary gear structure is connected to the axle of a car tire.

[0007] Furthermore, when the tire rotates, it drives the slider of the planetary gear structure to reciprocate linearly on the outer shell support. The upper friction layer and the lower metal electrode layer of the sawtooth triboelectric nanogenerator carry equal and opposite charges due to friction. The upper metal electrode generates induced charges due to electrostatic induction, and a potential difference is generated between the upper and lower metal electrodes. The frequency of the potential difference is related to the tire rotation speed.

[0008] Furthermore, the metal electrode layer of the sawtooth triboelectric nanogenerator is made of copper foil, and the friction layer is made of PTFE. Both the metal electrode layer and the friction layer are cut into a sawtooth shape using a laser cutting machine.

[0009] Furthermore, the hollow base, crank, outer shell base serving as the gear ring, and hub gear are made of POM material.

[0010] Furthermore, the connecting rod, slider, and housing support are made of acrylic material.

[0011] Furthermore, the stopper screw, long nut, and bolted bearing are standard parts.

[0012] The vehicle acceleration sensing algorithm is as follows:

[0013] Furthermore, when the slider reciprocates linearly on the outer shell support, the peak voltage output time of the sawtooth triboelectric nanogenerator is t1, and the adjacent valley voltage output time is t2. The slider displacement is constant during the time interval t1~t2, and is the length x of a single unit of the sawtooth electrode. Therefore, the slider sliding speed v is:

[0014] (1)

[0015] Furthermore, for the planetary gear structure, the functional relationship between the slider sliding speed v and the tire rotation speed w is as follows:

[0016] (2)

[0017] Furthermore, by differentiating the tire rotational speed w, the tire rotational angular acceleration α can be obtained.

[0018] Furthermore, the functional relationship between the vehicle's acceleration *a* and the tire's rotational angular acceleration *α* is:

[0019] (3)

[0020] Where D is the outer diameter of the tire.

[0021] Furthermore, the output voltage data of the sawtooth triboelectric nanogenerator is processed to accurately fit the vehicle's acceleration.

[0022] The crank, gear, gear ring, and connecting rod combine to form a planetary gear structure, which converts the rotational motion of the tire into the reciprocating linear motion of the slider. The crank angular displacement... With slider displacement The following functional relationship exists: R = 0.06cos θ (m).

[0023] The sawtooth-shaped triboelectric nanogenerator transforms the characteristics of reciprocating linear motion into easily measurable voltage signals. By processing the voltage data, the change in the number of voltage peaks enables precise sensing of acceleration.

[0024] The sawtooth triboelectric nanogenerator employs a structure with unequal lengths of the upper and lower triboelectric plates, resulting in better periodicity and symmetry in the output electrical signal.

[0025] The serrated triboelectric nanogenerator has a serrated structure for both its electrode layer and dielectric layer, which can greatly improve energy harvesting efficiency.

[0026] This invention addresses the problems and needs of existing technologies by utilizing a triboelectric nanogenerator as the sensing unit to design a self-driven sensor capable of accurately measuring vehicle acceleration. Compared with existing technologies, this invention has the following advantages:

[0027] 1. The self-driven accelerometer designed in this invention uses the output voltage signal of a triboelectric nanogenerator as the data basis to accurately fit the vehicle's acceleration. The designed sawtooth triboelectric nanogenerator improves the frequency of the output voltage signal, which greatly improves the accuracy of sensing the vehicle's acceleration.

[0028] 2. The self-driven accelerometer designed in this invention based on a planetary gear structure triboelectric nanogenerator does not require external power supply, thus achieving self-driving capability. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of the present invention;

[0030] Figure 2 for Figure 1 Exploded view (including: planetary gear structure A1, sawtooth triboelectric nanogenerator A2);

[0031] Figure 3 This is a schematic diagram of the assembly of crank A1-2;

[0032] Figure 4 This is a schematic diagram of the open-circuit voltage output of the triboelectric nanogenerator at 50 RPM in an embodiment of the present invention;

[0033] Figure 5 This is a schematic diagram illustrating the perception of vehicle speed in an embodiment of the present invention.

[0034] Figure 6 This is a schematic diagram illustrating the perception of vehicle acceleration according to an embodiment of the present invention;

[0035] In the diagram: planetary gear structure A1, hollow base A1-1, crank A1-2, outer shell base A1-3 as gear ring, bearing A1-4, hub gear A1-5, connecting rod A1-6, bolted bearing A1-7, angle bracket A1-8, long nut A1-9, outer shell support A1-10, slider A1-11, plug screw A1-12, sawtooth triboelectric nanogenerator A2; upper metal electrode layer A2-1, upper friction layer A2-2, lower metal electrode layer A2-3. Detailed Implementation

[0036] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0037] like Figure 1 As shown, a self-driven accelerometer based on a planetary gear structure triboelectric nanogenerator comprises a planetary gear structure A1 and a sawtooth triboelectric nanogenerator A2, wherein...

[0038] The planetary gear structure A1 includes a hollow base A1-1, a crank A1-2, a housing base A1-3 serving as the gear ring, a bearing A1-4, a hub gear A1-5, a connecting rod A1-6, a bolted bearing A1-7, a corner bracket A1-8, a long nut A1-9, a housing support A1-10, a slider A1-11, and a plug screw A1-12; the sawtooth triboelectric nanogenerator includes an upper metal electrode layer A2-1, an upper friction layer A2-2, and a lower metal electrode layer A2-3, wherein the upper metal electrode layer A2-1 is a 30mm×30mm sawtooth copper foil, the upper friction layer A2-2 is a 30mm×120mm sawtooth PTFE, and the lower metal electrode layer A2-3 is a 30mm×120mm sawtooth copper foil.

[0039] The self-driven accelerometer is connected to the tire axle via crank A1-2 in the planetary gear structure A1.

[0040] like Figure 2 As shown, the assembly process of the self-driven accelerometer based on the planetary gear structure triboelectric nanogenerator of this invention is as follows:

[0041] Furthermore, such as Figure 1 , Figure 2 , Figure 3 As shown, the input end of the crank A1-2 is connected to the tire axle via a light hole, the output end of the crank A1-2 is fitted with the inner ring of the bearing A1-4, the outer ring of the bearing A1-4 is fitted with the hub gear A1-5, and the bolt is connected to the internal threaded hole of the hub gear A1-5 through the through hole of the output end of the crank A1-2.

[0042] Furthermore, the hub gear A1-5 meshes with the inner gear ring of the outer shell base A1-3, which serves as the gear ring.

[0043] Furthermore, the outer shell base A1-3, which serves as the gear ring, is connected to the hollow base A1-1 by bolts, thereby restricting the degree of freedom of the crank A1-2 to enhance its motion stability.

[0044] Furthermore, the outer shell base A1-3, which serves as the gear ring, is connected to the outer shell support A1-10 via corner bracket A1-8.

[0045] Furthermore, the input end of the connecting rod A1-6 is connected to the hub gear A1-5 via a bolted bearing A1-7, and the output end is connected to the long nut A1-9 via a bolted bearing A1-7.

[0046] Furthermore, a plug screw A1-12 is used to pass through the through hole at the center of the slider A1-11 and connect to the long nut A1-9, thereby fixing the slider A1-11 to the outer casing bracket A1-10.

[0047] Furthermore, after the upper metal electrode layer A2-1 is bonded to the upper friction layer A2-2, the upper metal electrode layer A2-1 is bonded to the lower part of the slider A1-11.

[0048] Furthermore, the lower metal electrode layer A2-3 is bonded to the upper part of the outer casing support A1-10.

[0049] Furthermore, the normal pressure between the two friction layers of the triboelectric nanogenerator can be adjusted by screwing the stopper screw A1-12 into the long nut A1-9.

[0050] As an example, and not a limitation, the bolt is M4×20.

[0051] Figure 1 In the process, when the tire rotates, it drives the slider A1-11 of the planetary gear structure to perform reciprocating linear motion on the outer shell support A1-10. The upper friction layer A2-2 and the lower metal electrode layer A2-1 of the sawtooth triboelectric nanogenerator carry equal and opposite charges due to friction. The upper metal electrode A2-1 generates induced charges due to electrostatic induction. The magnitude of the voltage between the upper and lower metal electrode layers is detected by external equipment, and the obtained voltage data is processed based on the vehicle driving acceleration sensing algorithm. The vehicle driving acceleration is accurately sensed by relying on the peak and valley points of the output voltage.

[0052] like Figure 4 As shown, when the tire angular velocity is 50 RPM, the peak voltage of the triboelectric nanogenerator remains basically unchanged. By accurately capturing the moments of all peak and valley points, the sliding speed v of the slider is obtained by substituting it into equation (1), the tire rotation speed w is obtained by substituting v into equation (2), and the derivative of w is substituting it into equation (3) to obtain the vehicle acceleration.

[0053] Example 1

[0054] In this embodiment, a specific scenario is set: from 0 to 6 seconds, the car's speed is 3.2 m / s (11.4 km / h); from 6 to 10 seconds, the car obtains a constant acceleration of 0.789 m / s², undergoing uniform acceleration motion. Under this scenario, the feasibility and accuracy of the invented self-driven accelerometer based on a planetary gear structure triboelectric nanogenerator are preliminarily verified.

[0055] like Figure 5 As shown, the dashed line represents the set change in car speed, and the solid line represents the measurement results of the accelerometer based on the planetary gear structure friction nanogenerator of this invention. The measurement results are basically consistent with the actual situation, with small errors. Figure 6 As shown, the dashed line represents the set changes in vehicle acceleration, while the solid line represents the measurement results of the accelerometer based on the planetary gear friction nanogenerator of this invention. The results demonstrate that this invention can accurately measure the acceleration of a vehicle during driving over a wide range.

[0056] Furthermore, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. All equivalent or simple variations made based on the structure, features, and principles of the present invention are included within the protection scope of the present invention. Those skilled in the art can modify the technical solutions of each embodiment, or make equivalent substitutions for some or all of the technical features, as long as they do not deviate from the structure of the present invention or exceed the scope defined by the claims, and all such modifications should fall within the protection scope of the present invention.

Claims

1. A self-driven accelerometer based on a planetary gear structure frictional nanogenerator, characterized in that, The self-driving accelerometer comprises a planetary gear structure (A1) and a sawtooth-shaped friction nanometer generator (A2), and the input end of the planetary gear structure is connected with the axis of the tire. The planetary gear structure (A1) comprises a hollow base (A1-1), a crank (A1-2), a shell base (A1-3) as a gear ring, a bearing (A1-4), a hub gear (A1-5), a connecting rod (A1-6), a bolt bearing (A1-7), an angle code (A1-8), a long nut (A1-9), a shell support (A1-10), a sliding block (A1-11) and a plug screw (A1-12). The sawtooth-shaped friction nanometer generator comprises an upper metal electrode layer (A2-1), an upper friction layer (A2-2) and a lower metal electrode layer (A2-3). The self-driving accelerometer is connected with the tire axis through the crank (A1-2) in the planetary gear structure (A1). The input end of the crank (A1-2) is connected with the tire axis, the output end of the crank (A1-2) is matched with the inner ring of the bearing (A1-4), the outer ring of the bearing (A1-4) is matched with the hub gear (A1-5), the hub gear (A1-5) is engaged with the internal gear ring of the shell base (A1-3) as a gear ring, the shell base (A1-3) is connected with the hollow base (A1-1) to form a shell structure for protecting the gear ring and the tire and ensuring the isolation between them, the shell base (A1-3) as a gear ring is connected with the shell support (A1-10) through the angle code (A1-8), the input end of the connecting rod (A1-6) is connected with the hub gear (A1-5), and the output end is connected with the long nut (A1-9), the plug screw (A1-12) passes through the central through hole of the sliding block (A1-11) and is connected with the long nut (A1-9) to fix the sliding block (A1-11) and the shell support (A1-10), the upper metal electrode layer (A2-1) is adhered to the lower side of the sliding block (A1-11) after being adhered to the upper friction layer (A2-2), and the lower metal electrode layer (A2-3) is adhered to the upper side of the shell support (A1-10). 2.The self-driven accelerometer based on the planetary gear structure friction nanogenerator of claim 1, wherein, The upper metal electrode layer (A2-1) is a 30mm×30mm sawtooth-shaped copper foil, the upper friction layer (A2-2) is a 30mm×120mm sawtooth-shaped PTFE, and the lower metal electrode layer (A2-3) is a 30mm×120mm sawtooth-shaped copper foil. 3.The self-driven accelerometer based on the planetary gear structure friction nanogenerator of claim 1, wherein, The normal pressure between the two friction layers of the friction nanometer generator can be adjusted by adjusting the length of the plug screw (A1-12) screwed into the long nut (A1-9). 4.The self-driven accelerometer based on the planetary gear structure friction nanogenerator of claim 1, wherein, The crank, gear, gear ring and connecting rod are combined to form a planetary gear structure, so as to convert the rotating motion of the tire into the reciprocating linear motion of the sliding block, wherein the crank angular displacement and the sliding block displacement have the following functional relationship: R=0.06cos The sawtooth-shaped friction nanometer generator converts the characteristics of reciprocating linear motion into an easily measured voltage signal, and realizes accurate perception of acceleration by processing voltage data and relying on the change of the number of voltage peaks. (m). 5.The self-driven accelerometer based on the frictional nanogenerator with a planetary gear structure according to claim 1, wherein, The sawtooth-shaped friction nanometer generator adopts an unequal structure of the upper and lower friction layer plates, and the output electric signal shows better periodicity and symmetry. 6.The self-driven accelerometer based on the planetary gear structure friction nanogenerator of claim 1, wherein, ​ 7.The self-driven accelerometer based on the planetary gear structure friction nanogenerator of claim 1, wherein, A voltage data processing algorithm is developed to capture the peak and valley points of the sawtooth-shaped output voltage signal of the nanogenerator, so as to accurately fit the time points of the peak and valley points with the estimated points of the automobile driving acceleration.

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