Device and method for simulating negative acceleration output of aircraft wheel speed sensor

Abstract

A device and method for simulating the negative acceleration output of an aircraft wheel speed sensor. The output shaft of a servo motor 2 is connected to a speed reducer 15, and the output shaft of the speed reducer 15 is connected to a transmission shaft 4; the right end of the transmission shaft 4 is connected to a crank-link mechanism 5 and then connected to a speed increaser 11 through a coupling; the crank-link mechanism 5 transmits the rotation on the transmission shaft 4 to a negative acceleration output shaft 8; the negative acceleration output shaft 8 is controlled by an electric brake 13, and the negative acceleration output shaft 8 is connected to an electric clutch 12 through a coupling and is also connected to the speed increaser 11 through a coupling. The present invention can truly simulate the negative angular acceleration generated by an aircraft wheel speed sensor during an anti-skid braking process, achieve an accurate matching of the braking speed and negative acceleration of the wheel speed sensor, and efficiently conduct ground performance tests on the wheel speed sensor.

Description

Technical Field

[0001] The present invention belongs to the technical field of testing devices, and relates to the ground anti-skid performance testing of an aircraft brake system, in particular to a device and method for simulating the negative acceleration output of an aircraft wheel speed sensor. Background Art

[0002] As an important means of transportation and its important position in the military field, the safety performance of an aircraft is of crucial importance, which requires high reliability of each accessory system of the aircraft. The aircraft wheel anti-skid brake system is an important part of the aircraft, which is related to whether the aircraft can take off and land normally. Therefore, it is quite necessary to detect the aircraft wheel anti-skid brake system.

[0003] There are many testing devices for detecting the aircraft wheel anti-skid brake system. Most of them are for simulating wheel speed signals, brake control signals, and injecting fault signals, etc., and the detection principles are general.

[0004] For the performance detection of a special wheel speed sensor, this kind of wheel speed sensor adopts a pure mechanical working principle. During the skidding process when the average speed of the aircraft is uniform, the change of the internal oil pressure of the sensor is driven by the acceleration and deceleration of the aircraft wheel speed, and then the brake pressure is controlled through the oil pressure and the oil pressure change frequency.

[0005] This requires a simulation device that can simulate the true negative acceleration value of the speed under the condition of uniform average speed. The present invention designs a negative acceleration value simulation device, which can accurately and efficiently simulate the negative acceleration value during the rotation of the wheel, and realize the performance detection of the wheel speed sensor. Summary of the Invention

[0006] In order to solve the problems existing in the above-mentioned prior art, the present invention provides a device and method for simulating the negative acceleration output of an aircraft wheel speed sensor, which can truly simulate the negative angular acceleration generated by the aircraft wheel speed sensor during the anti-skid braking process, realize the accurate matching of the braking speed and negative acceleration of the wheel speed sensor, and efficiently conduct ground performance testing on the wheel speed sensor.

[0007] The technical solution adopted by the present invention to solve its technical problems is:

[0008] A device for simulating the negative acceleration output of an aircraft wheel speed sensor includes a base 1 arranged horizontally;

[0009] A servo motor 2 and a reducer 15 are installed on the right side of the base 1 through a support frame 14; the output shaft of the servo motor 2 is connected to the reducer 15, and the output shaft of the reducer 15 is connected to a transmission shaft 4;

[0010] In the middle of the base 1, a flywheel support 3 is installed. On both sides of the top of the flywheel support 3, bearing seats are provided. The transmission shaft 4 passes through the bearing seats on both sides and then extends out. Two sets of flywheel assemblies 10 are symmetrically and fixedly installed at both ends of the transmission shaft 4. The flywheel assembly 10 on the right end is installed close to the servo drive system 2, and the flywheel assembly 10 on the left end is installed close to the crank - connecting rod mechanism 5; the right end of the transmission shaft 4 is connected to the crank - connecting rod mechanism 5 and then connected to the speed increaser 11 through a coupling; the crank - connecting rod mechanism 5 transfers the rotation on the transmission shaft 4 to the negative acceleration output shaft 8;

[0011] On the left side of the base 1, a movable base 7 is provided. On the movable base 7, a speed increaser 11, an electric clutch 12, an electric brake 13, and a shaft support seat 9 are provided. On both sides of the top of the shaft support seat 9, bearing seats are provided. The negative acceleration output shaft 8 passes through the bearing seats on both sides and then extends out. The negative acceleration output shaft 8 is controlled by the electric brake 13. The negative acceleration output shaft 8 is connected to the electric clutch 12 through a coupling and is connected to the speed increaser 11 through a coupling.

[0012] A method for simulating the negative acceleration output of an aircraft wheel speed sensor includes the following steps:

[0013] Step a: Adjust the eccentricity adjustment mechanism 6 so that the eccentricity e between the transmission shaft 4 and the negative acceleration output shaft 8 is greater than 0;

[0014] Step b: The servo motor 2 operates, and through the crank - connecting rod mechanism 5, the rotation on the transmission shaft 4 is transferred to the negative acceleration output shaft 8. Due to the existence of the eccentricity e, when the output shaft 8 rotates one week, a maximum negative acceleration appears once, and a maximum positive acceleration appears once. The speed shows periodic pulsating changes, and the average speed remains unchanged;

[0015] Step c: Connect the input shaft of the flywheel assembly 10 to the negative acceleration output shaft 8. Assume that the input speed of the flywheel assembly 10 is n1 (or ω1, and the angular acceleration is ε1), the speed of the negative acceleration output shaft 8 is n2 (or ω2, and the angular acceleration is ε2), and the input speed of the transmission shaft 4 is n3 (or ω3, and the angular acceleration is ε3). The relationship between positive and negative acceleration changes is obtained. The following is the simplified relationship:

[0016]

[0017] ω3 = iω2;

[0018]

[0019] Among them, e is the eccentricity, and r is the effective length of the connecting rod in the crank - connecting rod mechanism. ω 2max refers to the maximum speed of the output shaft 8, ω1 refers to the input speed of the flywheel assembly 10, ω 2min refers to the minimum speed of the output shaft 8, ε 2maxRefers to the maximum angular acceleration of the output shaft 8, ε1 is the angular acceleration, ε 2min Refers to the minimum angular acceleration of the output shaft 8, ω3 refers to the input speed of the transmission shaft 4, i is the speed ratio of the speed increaser, ω2 refers to the speed of the output shaft 8 with negative acceleration, ε 3max Refers to the maximum angular acceleration of the transmission shaft 4.

[0020] Compared with the prior art, the advantages of the present invention are as follows:

[0021] The present invention can truly simulate the negative angular acceleration generated by the aircraft wheel speed sensor during the anti-skid braking process, achieve the accurate matching of the braking speed and negative acceleration of the wheel speed sensor, and efficiently conduct ground performance tests on the wheel speed sensor.

[0022] The additional aspects and advantages of the present invention will be partially given in the following description, partially become obvious from the following description, or be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0024] Figure 1 Is the schematic diagram of the device for simulating the negative acceleration output of the aircraft wheel speed sensor of the present invention;

[0025] Figures 2 - 3 Is the top view of the device for simulating the negative acceleration output of the aircraft wheel speed sensor of the present invention;

[0026] Figure 4 Is the three-dimensional structure schematic diagram of the device for simulating the negative acceleration output of the aircraft wheel speed sensor of the present invention;

[0027] Figure 5 Is the front view structure schematic diagram of the device for simulating the negative acceleration output of the aircraft wheel speed sensor of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0028] The following will describe in more detail the exemplary embodiments disclosed by the present invention with reference to the drawings. These embodiments are for the purpose of more thoroughly understanding the present invention and being able to completely convey the scope of the present invention to those skilled in the art. Although the exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention should not be limited by the embodiments described herein.

[0029] A device for simulating the negative acceleration output of an aircraft wheel speed sensor, including a base 1 arranged horizontally. The base 1 is processed from steel material and is used for the stability and bearing of the whole device.

[0030] On the right side of the base 1, a servo motor 2 and a reducer 15 are installed through a support frame 14; the output shaft of the servo motor 2 is connected to the reducer 15, and the output shaft of the reducer 15 is connected to a transmission shaft 4;

[0031] The servo motor 2 is a high-speed servo motor; the reducer 15 is a planetary reducer 15; the high-speed servo motor and the planetary reducer 15 form a servo motor drive system. The servo motor drive system ensures that the transmission shaft 4 can reach a reasonable speed range on the one hand, and ensures that the servo motor 2 has a high output torque on the other hand.

[0032] In the middle of the base 1, a flywheel support 3 is installed. On both sides of the top of the flywheel support 3, there are bearing seats. The transmission shaft 4 passes through the two bearing seats and extends out. Two groups of flywheel assemblies 10 are symmetrically and fixedly installed at both ends of the transmission shaft 4. The right flywheel assembly 10 is installed close to the servo drive system 2, and the left flywheel assembly 10 is installed close to the crank-link mechanism 5. The crank-link mechanism 5 realizes the transmission of the rotation on the transmission shaft 4 to the negative acceleration output shaft 8. After the right end of the transmission shaft 4 is connected to the crank-link mechanism 5, it is connected to a speed increaser 11 through a coupling; the crank-link mechanism 5 transmits the rotation on the transmission shaft 4 to the negative acceleration output shaft 8;

[0033] The two groups of flywheel assemblies 10 are made of symmetrically installed homogeneous steel materials, aiming to overcome the shaking problem of the crank-link mechanism 5 under high-speed rotation and improve the stability and reliability of the system.

[0034] On the left side of the base 1, a movable base 7 is provided. On the movable base 7, a speed increaser 11, an electric clutch 12, an electric brake 13, and a shaft support seat 9 are provided. On both sides of the top of the shaft support seat 9, there are bearing seats. The negative acceleration output shaft 8 passes through the two bearing seats and extends out. The negative acceleration output shaft 8 is controlled by the electric brake 13. The negative acceleration output shaft 8 is connected to the electric clutch 12 through a coupling and is connected to the speed increaser 11 through a coupling.

[0035] The speed increaser 11, the electric clutch 12, the electric brake 13, and the negative acceleration output shaft 8 are coaxially installed, and the whole forms an output shaft system. The other end of the crank-link mechanism 5 is connected to the speed increaser 11, thereby connecting the servo motor drive system and the output shaft system.

[0036] The crank - connecting rod mechanism 5 includes a crank 5 - a, a connecting rod 5 - b, and a first slider 5 - c; where: the connecting rod 5 - b is a U - shaped chute. The connecting rod 5 - b is driven by the transmission shaft 4 to rotate around the normal center line of the connecting rod 5 - b, and the normal center of the connecting rod 5 - b and the normal center of the transmission shaft 4 are co - axial. The top of the crank 5 - a of the crank - connecting rod mechanism 5 is installed with a first slider 5 - c, and the first slider 5 - c is embedded in the connecting rod 5 - b. When the flywheel rotates, the first slider 5 - c drives the crank 5 - a to rotate along with the rotation of the connecting rod 5 - b; the first slider 5 - c is a deep - groove ball bearing. The U - shaped chute is fixedly installed on the left - end flywheel assembly 10 and is centrosymmetric, and rotates along with the rotation of the left - end flywheel assembly 10.

[0037] The first slider 5 - c is a deep - groove ball bearing, which can greatly reduce the friction between the slider and the U - shaped groove, and improve the stability of the system under high - speed operation.

[0038] The movable base 7 is driven by the eccentricity - adjusting mechanism 6 to move. The eccentricity - adjusting mechanism 6 includes an electric cylinder 601, a linear guide 603, and a second slider 602; on the surface of the base 1, there are an electric cylinder 601 and a linear guide 603, and on the bottom of the movable base 7, there is a second slider 602; the second slider 602 is installed on the linear guide 603. The linear guide 603 and the second slider 602 form a self - locking trapezoidal screw pair, which can achieve self - locking at any position. The fixed end of the electric cylinder 601 is installed on the surface of the base 1, and the telescopic end of the electric cylinder 601 is installed on the bottom of the movable base 7. The electric cylinder 601 can drive the movable base 7 to make a linear reciprocating motion relative to the base 1 on the linear guide 603, so as to realize the adjustment of the eccentricity between the transmission shaft 4 and the negative - acceleration output shaft 8. A displacement sensor 604 is installed at the telescopic end of the electric cylinder 601. When the electric cylinder 601 controls the movable base 7 to reach the required eccentricity position, the displacement sensor 604 outputs a signal to the control system and stops moving. When the device that simulates the negative - acceleration output runs at high speed, there will be a slight jitter in the system. Because a self - locking trapezoidal screw pair is adopted, the movable base 7 will not move retrogressively and is firmly locked at the control position, realizing the precise control of the eccentricity.

[0039] A method for simulating the negative - acceleration output of an aircraft wheel - speed sensor includes the following steps:

[0040] Step a: Adjust the eccentricity - adjusting mechanism 6 so that the eccentricity e between the transmission shaft 4 and the negative - acceleration output shaft 8 is greater than 0;

[0041] Step b: The servo motor 2 operates, and through the crank - connecting rod mechanism 5, the rotation on the transmission shaft 4 is transmitted to the negative - acceleration output shaft 8. Due to the existence of the eccentricity e, when the output shaft 8 rotates one week, there will be a maximum value of negative acceleration once and a maximum value of positive acceleration once, the speed shows periodic pulsating changes, and the average speed remains unchanged;

[0042] Step c: Connect the input shaft of the flywheel assembly 10 to the negative acceleration output shaft 8. Assume the input speed of the flywheel assembly 10 is n1 or ω1, the angular acceleration is ε1, the speed of the negative acceleration output shaft 8 is n2 or ω2, and the angular acceleration is ε2, and the input speed of the transmission shaft 4 is n3 or ω3, and the angular acceleration is ε3, to obtain the relationship between positive and negative acceleration changes.

[0043] As Figures 3 - 5 shown, the eccentricity of the device can be adjusted from 0 to 45 mm, and this distance is only the adjustment of the axis distance in the horizontal direction. The input shaft and the output axis always remain in the same horizontal position in the longitudinal position, thereby reducing the influence of the error amount on the system simulation accuracy.

[0044] Finally, the speed increaser is used to increase the speed of the output shaft to reach the true operating speed range of the aircraft wheel speed sensor. The clutch is used to disconnect and connect the output shaft and the input shaft of the wheel speed sensor to achieve the free rotation of the wheel speed sensor and simulate the rotation state during aircraft taxiing. The brake is installed between the clutch and the wheel speed sensor and is used to brake the wheel speed sensor after the clutch is disconnected, simulating the braking condition during aircraft taxiing.

[0045] According to the device for simulating negative acceleration output to generate positive and negative accelerations of the wheel speed sensor, and truly simulate the changes in speed and acceleration during aircraft braking in the taxiing state. The implementation method is as follows:

[0046] When the driving servo system rotates at a specified speed, the slider of the crank - connecting rod mechanism will rotate and reciprocate along one side of the U - shaped chute of the flywheel under the drive of the flywheel. Therefore, it shows that the rotation speed of the connecting rod is faster when the slider is closer to the rotation center of the flywheel in the U - shaped chute, and on the contrary, the rotation speed of the connecting rod is slower when it is farther away from the rotation center of the flywheel. And for each rotation of the flywheel, the speed will have a positive angular velocity and a negative angular velocity once. By adjusting the rotation speed and speed ratio parameters of the device, the accurate simulation of the change value and change frequency of the true wheel speed can be achieved.

[0047] Assume the input speed of the flywheel 10 is n1 (or ω1, and the angular acceleration is ε1), the output speed of the negative acceleration generator is n2 (or ω2, and the angular acceleration is ε2), and the input speed of the product shaft is n3 (or ω3, and the angular acceleration is ε3), to obtain the following simplified relationship:

[0048]

[0049] ω3 = iω2

[0050]

[0051] e is the eccentricity, and r is the effective length of the connecting rod in the crank - connecting rod mechanism. ω2max represents the maximum speed of the output shaft 8, ω1 represents the input rotational speed of the flywheel assembly 10, ω 2min represents the minimum speed of the output shaft 8, ε 2max represents the maximum angular acceleration of the output shaft 8, ε1 is the angular acceleration, ε 2min represents the minimum angular acceleration of the output shaft 8, ω3 represents the input rotational speed of the transmission shaft 4, i is the

[0052] Obviously, with a constant-speed input, after passing through the negative acceleration generator, the average speed remains unchanged, but the speed exhibits periodic pulsations (jittering once per revolution: from the highest to the lowest and then back to the highest), with one maximum value of negative acceleration and one maximum value of positive acceleration. After passing through the speed increaser, the speed and acceleration are further proportionally increased.

[0053]

[0054] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention have been clearly and completely described above in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated in the drawings here can be arranged and designed in various different configurations.

[0055] Therefore, the above detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents the selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0056] In the description of the present invention, it should be noted that the orientation or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, or the orientation or positional relationships in which the products of the invention are customarily placed during use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive distinction and should not be construed as indicating or implying relative importance.

[0057] In the description of the present invention, it should also be noted that, unless otherwise clearly defined and limited, the terms "set", "install", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

Claims

1. A device for simulating the negative acceleration output of an aircraft wheel speed sensor, characterized in that, It includes a base (1) arranged horizontally; A servo motor (2) and a speed reducer (15) are installed on the right side of the base (1) through a support frame (14); the output shaft of the servo motor (2) is connected to the speed reducer (15), and the output shaft of the speed reducer (15) is connected to a transmission shaft (4); A flywheel support (3) is installed in the middle of the base (1). Bearing seats are arranged on both sides of the top of the flywheel support (3). The transmission shaft (4) passes through the bearing seats on both sides and then extends out. Two groups of flywheel assemblies (10) are symmetrically and fixedly installed at both ends of the transmission shaft (4). The flywheel assembly (10) at the right end is installed close to the servo drive system (2), and the flywheel assembly (10) at the left end is installed close to the crank - connecting rod mechanism (5); the right end of the transmission shaft (4) is connected to the crank - connecting rod mechanism (5) and then connected to a speed increaser (11) through a coupling; the crank - connecting rod mechanism (5) transmits the rotation on the transmission shaft (4) to the negative acceleration output shaft (8); An adjustable base (7) is arranged on the left side of the base (1). A speed increaser (11), an electric clutch (12), an electric brake (13), and a shaft support seat (9) are arranged on the adjustable base (7). Bearing seats are arranged on both sides of the top of the shaft support seat (9). The negative acceleration output shaft (8) passes through the bearing seats on both sides and then extends out. The negative acceleration output shaft (8) is controlled by the electric brake (13). The negative acceleration output shaft (8) is connected to the electric clutch (12) through a coupling and is also connected to the speed increaser (11) through a coupling; The crank - connecting rod mechanism (5) includes a crank (5 - a), a connecting rod (5 - b), and a first slider (5 - c); among them: the connecting rod (5 - b) is a U - shaped chute. The connecting rod (5 - b) is driven by the transmission shaft (4) to rotate around the normal center line of the connecting rod (5 - b), and the normal center of the connecting rod (5 - b) and the normal center of the transmission shaft (4) are on the same axis; the top of the crank (5 - a) of the crank - connecting rod mechanism (5) is installed with a first slider (5 - c), and the first slider (5 - c) is embedded in the connecting rod (5 - b). As the connecting rod (5 - b) rotates, it drives the crank (5 - a) to rotate; the first slider (5 - c) is a deep - groove ball bearing.

2. The device for simulating the negative acceleration output of an aircraft wheel speed sensor according to claim 1, characterized in that: The U - shaped chute is fixedly installed on the left - end flywheel assembly (10) and is centrosymmetric, and rotates as the left - end flywheel assembly (10) rotates.

3. The device for simulating the negative acceleration output of an aircraft wheel speed sensor according to claim 1, characterized in that: The adjustable base (7) is driven by an eccentricity - adjusting mechanism (6) to move. The eccentricity - adjusting mechanism (6) includes an electric cylinder (601), a linear guide rail (603), and a second slider (602); an electric cylinder (601) and a linear guide rail (603) are arranged on the surface of the base (1), and a second slider (602) is arranged at the bottom of the adjustable base (7); the second slider (602) is installed on the linear guide rail (603). The fixed end of the electric cylinder (601) is installed on the surface of the base (1), and the telescopic end of the electric cylinder (601) is installed at the bottom of the adjustable base (7). The electric cylinder (601) can drive the adjustable base (7) to perform a linear reciprocating motion relative to the base (1) on the linear guide rail (603), so as to realize the adjustment of the eccentricity between the transmission shaft (4) and the negative acceleration output shaft (8).

4. The device for simulating the negative acceleration output of an aircraft wheel speed sensor according to claim 1, characterized in that: A displacement sensor (604) is installed at the telescopic end of the electric cylinder (601).

5. The device for simulating the negative acceleration output of an aircraft wheel speed sensor according to claim 3, wherein: The linear guide rail (603) and the second slider (602) form a self-locking trapezoidal lead screw pair.

6. The device for simulating the negative acceleration output of an aircraft wheel speed sensor according to claim 1, characterized in that: The servo motor (2) is a high-speed servo motor; the reducer (15) is a planetary reducer; the high-speed servo motor and the planetary reducer (15) form a servo motor drive system.

7. A method for simulating the negative acceleration output of an aircraft wheel speed sensor based on the device for simulating the negative acceleration output of an aircraft wheel speed sensor according to claim 1, characterized in that, It includes the following steps: Step a: Adjust the eccentricity adjusting mechanism (6) so that the eccentricity e between the transmission shaft (4) and the negative acceleration output shaft (8) is greater than 0; Step b: The servo motor (2) operates, and through the crank and connecting rod mechanism (5), the rotation on the transmission shaft (4) is transmitted to the negative acceleration output shaft (8). Due to the existence of the eccentricity e, the output shaft (8) will have a maximum negative acceleration once every rotation, and a maximum positive acceleration once, the speed shows periodic pulsating changes, and the average speed remains unchanged; Step c: Connect the input shaft of the flywheel assembly (10) to the negative acceleration output shaft (8). Assuming that the input speed of the flywheel assembly (10) is ω1, the speed of the negative acceleration output shaft (8) is ω2, and the input speed of the transmission shaft (4) is ω3, the relationship between positive and negative acceleration changes is obtained. The following is the simplified relationship: ω3 = iω2; where, e is the eccentricity, r is the effective length of the connecting rod in the crank connecting rod mechanism; ω 2max refers to the maximum speed of the output shaft (8), ω1 refers to the input speed of the flywheel assembly (10), ω 2min refers to the minimum speed of the output shaft 8, ε 2max refers to the maximum angular acceleration of the output shaft (8), ε1 is the angular acceleration, ε 2min refers to the minimum angular acceleration of the output shaft (8), ω3 refers to the input speed of the transmission shaft (4), i is the speed ratio of the speed increaser, ω2 refers to the speed of the output shaft (8) with negative acceleration, ε 3max refers to the maximum angular acceleration of the transmission shaft (4).

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