Method for checking stroke and rotation angle of shock absorber for rail transit

Abstract

The invention discloses a method for checking the stroke and the corner of a shock absorber for rail transit, and relates to the technical field of rail transit, the method for checking the stroke and the corner of the shock absorber for rail transit comprises the following steps: acquiring installation parameters of an oil pressure shock absorber; establishing a three-dimensional coordinate system by taking the center of motion of the vehicle as a reference point, and projecting the spatial relative position of the end joint of the oil damper into a two-dimensional plane; sequentially converting the three-dimensional motion of the oil damper relative to the motion center of the vehicle into two-dimensional feature point motion on each projection plane in a two-dimensional plane; and accumulating and checking the two-dimensional feature point motion on each projection surface to obtain the motion displacement expression of the oil damper, so as to realize the stroke and corner checking of the oil damper. The space relative position of the vehicle and the shock absorber is converted into the two-dimensional plane point projection through the two-dimensional drawing software, the relative motion between the vehicle and the shock absorber is converted into the plane line motion, and the limit stroke of the shock absorber and the limit deflection angle and torsion angle of the joint can be directly and accurately calculated.

Description

Technical Field

[0001] The present invention relates to the technical field of rail transit, and in particular to a method for calibrating the stroke and rotation angle of a shock absorber for rail transit. Background Art

[0002] Hydraulic shock absorbers have good vibration reduction and damping effects. They mainly achieve vibration reduction by forming hydraulic damping force through the reciprocating motion of the stretching and compressing piston rod. They are important vibration reduction components in the suspension system in the rail transit field.

[0003] The selection and design of hydraulic shock absorbers mainly include damping performance parameters and external interface dimensions. Its damping performance parameters play a very critical role in the vehicle's running stability, comfort and safety. Before performance design, the shock absorber must first meet the interface requirements required by the vehicle, such as installation length, maximum stretching length, minimum compression length, end joints, and deflection and torsion angles.

[0004] In the process of rail transit vehicle design, the stroke and installation interface of the oil shock absorber need to be obtained according to the design installation position of the oil shock absorber and the theoretical simulation of the vehicle operating conditions as the design input of the shock absorber. Therefore, for the field of rail transit, it is necessary and important to establish a reliable method for checking the stroke, end joint deflection and torsion angle of the shock absorber. It is the premise of the performance selection and design of the oil shock absorber, and it is also the key to the overall design of rail transit vehicles and to ensure the stability of dynamic performance.

[0005] Currently, no effective solution has been proposed for the problems in the related technologies. Summary of the invention

[0006] In view of the problems in the related art, the present invention proposes a method for calibrating the stroke and rotation angle of a shock absorber for rail transit, so as to overcome the above-mentioned technical problems existing in the existing related art.

[0007] To this end, the specific technical solution adopted by the present invention is as follows: A method for checking the stroke and rotation angle of a shock absorber for rail transit, the method comprising: Acquire installation parameters of the oil pressure shock absorber, and determine actual operating conditions of the oil pressure shock absorber based on the installation parameters of the oil pressure shock absorber; A three-dimensional coordinate system is established with the vehicle's motion center as the reference point, and the spatial relative positions of the hydraulic shock absorber end joints are projected onto a two-dimensional plane; The three-dimensional motion of the oil pressure shock absorber relative to the vehicle motion center is sequentially converted into the two-dimensional characteristic point motion on each projection surface in the two-dimensional plane; The motion of the two-dimensional feature points on each projection surface is accumulated and checked to obtain the motion displacement of the hydraulic shock absorber, so as to realize the stroke and rotation angle verification of the hydraulic shock absorber.

[0008] Preferably, the stroke and rotation angle of the oil shock absorber include the maximum stretching length, the minimum compression length, the joint deflection angle and the joint torsion angle of the oil shock absorber.

[0009] Preferably, the end joints of the oil shock absorber include an upper end joint of the oil shock absorber and a lower end joint of the oil shock absorber.

[0010] Preferably, establishing a three-dimensional coordinate system with the vehicle motion center as a reference point, and projecting the spatial relative position of the end joint of the hydraulic shock absorber onto a two-dimensional plane includes: A three-dimensional space coordinate system is established by taking the vehicle motion center of the oil pressure shock absorber relative to the vehicle bogie as a reference point; When the lower joint of the oil shock absorber is kept fixed, the limit displacement of the upper joint of the oil shock absorber relative to the vehicle's motion center is analyzed; The spatial relative position of the end joint of the oil shock absorber with respect to the vehicle's motion center is projected onto the xy horizontal plane and the yz horizontal plane respectively.

[0011] Preferably, the limit displacement of the upper joint of the oil shock absorber relative to the vehicle's motion center is the maximum displacement of the upper joint of the oil shock absorber relative to the vehicle's motion center in the longitudinal, lateral and vertical directions respectively.

[0012] Preferably, the motion displacement expression of the oil pressure shock absorber obtained by accumulating and checking the motion of the two-dimensional feature points on each projection surface includes: Calculate the maximum stretching length of the oil shock absorber in the xy horizontal plane and the yz horizontal plane; calculate the minimum compression length based on the actual operating conditions of the oil shock absorber; Calculate the joint deflection angle and joint torsion angle of the end joint of the hydraulic shock absorber when it moves longitudinally, transversely and vertically respectively.

[0013] Preferably, calculating the maximum stretching length of the oil shock absorber in the xy horizontal plane and the yz horizontal plane includes: Adjust the placement position of the oil pressure shock absorber according to the preset conditions, and project the end joint of the oil pressure shock absorber into the same feature point in the xy horizontal plane; Keep the lower end joint of the hydraulic shock absorber fixed, and move the upper end joint of the hydraulic shock absorber along the longitudinal and transverse directions of the vehicle; Connect the joint positions of the ends of the oil shock absorber to obtain the stretched length of the oil shock absorber in the xy horizontal plane; The end joint of the hydraulic shock absorber is projected into the yz horizontal plane, and the stretched length of the hydraulic shock absorber in the xy horizontal plane is accumulated while performing point motion in the yz horizontal plane to obtain the maximum stretched length of the hydraulic shock absorber.

[0014] Preferably, the end joint of the hydraulic shock absorber is projected into the yz horizontal plane, and the stretched length of the hydraulic shock absorber in the xy horizontal plane is accumulated while performing point motion in the yz horizontal plane, and the maximum stretched length of the hydraulic shock absorber is obtained, which includes: Project a line segment of a preset length on the end joint of the oil pressure shock absorber in the yz horizontal plane; Keep the lower joint of the hydraulic shock absorber fixed, and move the upper joint of the hydraulic shock absorber vertically; Combined with the stretching length of the upper joint of the hydraulic shock absorber in the xy horizontal plane, the maximum stretching length of the hydraulic shock absorber is obtained by two-dimensional vector superposition.

[0015] Preferably, when the oil pressure shock absorber moves in the vertical direction, the length of the oil pressure shock absorber at this time is the minimum compression length.

[0016] Preferably, calculating the joint deflection angle and the joint torsion angle of the end joint of the oil pressure shock absorber when the joint moves longitudinally, transversely and vertically respectively includes: Based on the installation parameters of the oil pressure shock absorber, the corresponding relationship between the movement direction of the oil pressure shock absorber and the joint deflection and the joint torsion is determined; When the joint at the end of the oil shock absorber is oriented parallel to the longitudinal direction, the oil shock absorber is moved downward in the longitudinal direction and vertical direction in sequence. At this time, the joint at the end of the oil shock absorber is in a deflected state, and the maximum joint deflection angle of the oil shock absorber is generated; When the oil shock absorber moves downward in the lateral and vertical directions in turn, the end joints of the oil shock absorber are in a torsion state, and a maximum joint torsion angle of the oil shock absorber is generated.

[0017] The beneficial effects of the present invention are: 1. The present invention uses two-dimensional drawing software to convert the spatial relative position of the vehicle and the shock absorber into a two-dimensional plane point projection, and converts the relative motion between the two into a plane line motion, which can directly and accurately calculate the shock absorber limit travel and the joint limit deflection angle and torsion angle.

[0018] 2. The calibration method provided by the present invention is suitable for the stroke calibration of shock absorbers in different installation positions, such as lateral shock absorbers, vertical shock absorbers and anti-snaking shock absorbers. Compared with the method of using a three-dimensional model for spatial motion to achieve stroke calibration, the two-dimensional calibration method that converts spatial relative motion into relative motion between plane points can greatly reduce the time for establishing a physical model and improve the efficiency of stroke calibration.

[0019] 3. The accurate shock absorber stroke, joint deflection and torsion angle verification calculation proposed in the present invention can be directly used as the technical input requirement for the performance selection and design of the hydraulic shock absorber, avoiding the problems of shock absorber design difficulties and long cycles caused by unclear requirements, and also contributes to the overall design of rail vehicle bogies. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 is a flow chart of a method for calibrating the stroke and rotation angle of a shock absorber for rail transit according to an embodiment of the present invention; Figure 2 It is a three-dimensional schematic diagram of the relative positions of a rail transit vehicle bogie and a secondary vertical hydraulic shock absorber in a method for calibrating the stroke and rotation angle of a rail transit shock absorber according to an embodiment of the present invention; Figure 3 It is a schematic diagram of vertical shock absorber stroke verification in a method for verifying the stroke and rotation angle of a shock absorber for rail transit according to an embodiment of the present invention; Figure 4 It is a schematic diagram of checking the joint deflection and torsion angle of a vertical shock absorber in a method for checking the stroke and rotation angle of a shock absorber for rail transit according to an embodiment of the present invention.

[0022] In the figure: 1. Vehicle bogie; 2. Hydraulic shock absorber; 3. End joint of hydraulic shock absorber. DETAILED DESCRIPTION

[0023] To further illustrate each embodiment, the present invention provides drawings, which are part of the disclosure of the present invention and are mainly used to illustrate the embodiments. They can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, ordinary technicians in this field should be able to understand other possible implementation methods and advantages of the present invention.

[0024] According to an embodiment of the present invention, a method for calibrating the stroke and rotation angle of a shock absorber for rail transit is provided.

[0025] The present invention will now be further described with reference to the accompanying drawings and specific embodiments. Figure 1 As shown, according to the method for checking the stroke and the rotation angle of the shock absorber for rail transit according to the embodiment of the present invention, the method for checking the stroke and the rotation angle of the shock absorber for rail transit includes: S1. Obtain installation parameters of the oil pressure shock absorber, and determine actual operating conditions of the oil pressure shock absorber based on the installation parameters of the oil pressure shock absorber.

[0026] It should be noted that the installation position of the oil pressure shock absorber 2 is as follows: Figure 2As shown, it includes a vehicle bogie 1, a hydraulic shock absorber 2 and an end joint 3 of the hydraulic shock absorber. The end joint 3 of the hydraulic shock absorber includes an upper joint and a lower joint. The lower joint of the hydraulic shock absorber 2 is connected to the vehicle bogie 1, and the upper joint is connected to the vehicle body. The stroke change of the hydraulic shock absorber 2 is mainly caused by the relative movement between the vehicle body and the vehicle bogie 1. The installation parameters of the hydraulic shock absorber 2 include the installation position, the installation length and the end connection structure; the maximum stretching length and the minimum compression length stroke can be obtained by analyzing the relative positions of the upper and lower joints.

[0027] It should be noted that the installation length of the hydraulic shock absorber 2 and the displacements a, b, and c in the subsequent content are all input parameters for verification. First, the installation position and the limit operating displacement of the hydraulic shock absorber 2 must be clarified, so as to transform and simulate the spatial motion and verify the required stroke and joint torsion angle.

[0028] S2. Establish a three-dimensional coordinate system with the vehicle motion center as a reference point, and project the spatial relative position of the hydraulic shock absorber end joint 3 into a two-dimensional plane.

[0029] Among them, establishing a three-dimensional coordinate system with the vehicle motion center as a reference point and projecting the spatial relative position of the hydraulic shock absorber end joint 3 onto a two-dimensional plane includes: A three-dimensional space coordinate system is established by taking the vehicle motion center of the oil pressure shock absorber 2 relative to the vehicle bogie 1 as a reference point; When the lower joint of the hydraulic shock absorber 2 remains fixed, the limit displacement of the upper joint of the hydraulic shock absorber 2 relative to the vehicle's motion center is analyzed; specifically, the maximum displacement of the upper joint of the hydraulic shock absorber 2 relative to the vehicle's motion center along the longitudinal, lateral and vertical directions.

[0030] The spatial relative position of the oil shock absorber end joint 3 with respect to the vehicle motion center is projected onto the xy horizontal plane and the yz horizontal plane respectively.

[0031] It should be noted that, according to the design plan of rail transit vehicles, the hydraulic shock absorber is clearly defined as point O relative to the motion center of the bogie, and a spatial coordinate system (x-longitudinal, y-lateral, z-vertical) is established, and the installation position of the shock absorber from point O is determined to be (x1, y1) and the installation length L; the lower end joint of the shock absorber is stipulated to be fixed, and according to the operating limits in various directions of the vehicle design, the limit displacement of the upper end joint of the shock absorber relative to the center point O is determined, which are a, b, and c along the x-longitudinal, y-lateral, and z-vertical directions respectively; the three-dimensional spatial positions of the upper and lower end joints of the shock absorber relative to the center of the bogie are projected onto the xy plane and the yz plane respectively.

[0032] S3, sequentially converting the three-dimensional motion of the oil pressure shock absorber 2 relative to the motion center of the vehicle into the two-dimensional feature point motion on each projection surface in the two-dimensional plane; S4. Accumulate and check the motion of the two-dimensional feature points on each projection surface to obtain the motion displacement representation of the oil pressure shock absorber 2, so as to realize the stroke and rotation angle verification of the oil pressure shock absorber 2.

[0033] It should be noted that when selecting and designing the hydraulic shock absorber 2, a preliminary design of the external interface will be carried out based on the product characteristics and on the premise of satisfying the damping performance, such as the theoretical stroke and the angular torsion angle that can be achieved by the joint. For the specific bogie platform and the actual application status of the hydraulic shock absorber 2, it is necessary to carry out a targeted stroke verification of the hydraulic shock absorber 2 to determine whether the provided hydraulic shock absorber 2 can meet the actual application requirements of the platform. The present invention simulates the spatial motion of the hydraulic shock absorber 2 during actual use through the two-dimensional relative motion between plane points, calculates the actual application stroke and the angular torsion angle of the hydraulic shock absorber 2, and thereby realizes the verification of the stroke and angle of the hydraulic shock absorber 2.

[0034] Among them, the stroke and rotation angle of the oil shock absorber 2 include the maximum stretching length, minimum compression length, joint deflection angle and joint torsion angle of the oil shock absorber 2; the end joint 3 of the oil shock absorber includes the upper joint of the oil shock absorber 2 and the lower joint of the oil shock absorber 2.

[0035] The motion displacement of the oil pressure shock absorber 2 obtained by accumulating and checking the motion of the two-dimensional feature points on each projection surface includes: The maximum stretching length of the oil pressure shock absorber 2 is calculated in the xy horizontal plane and the yz horizontal plane; the minimum compression length is calculated according to the actual operating condition of the oil pressure shock absorber 2.

[0036] It should be noted that, assuming that the shock absorber is placed completely vertically without an inclination angle, the upper and lower joints of the shock absorber are projected to the same point (x1, y1) in the xy horizontal plane. The lower joint of the shock absorber remains stationary, and the upper joint moves along the x-longitudinal direction a and along the y-lateral direction b with the vehicle. At this time, the positions of the upper and lower joint points on the line are connected, and the shock absorber is stretched to a length L in the xy plane. xy .

[0037] Similarly, in the yz plane, the projections of the upper and lower joints of the shock absorber can be connected into a line segment of length L. The lower joint of the shock absorber remains stationary, and the upper joint moves along the z-vertical direction c. At the same time, consider that the upper joint moves L in the xy plane. xy The maximum stretching length L of the shock absorber can be obtained by superimposing two-dimensional vectors. max .

[0038] According to the analysis of the operating conditions of the shock absorber, when the shock absorber only moves downward along the z-vertical direction c, the length of the shock absorber is the minimum state, that is, L min .

[0039] The maximum stretching length of the oil pressure shock absorber 2 calculated in the xy horizontal plane and the yz horizontal plane includes: Adjust the placement position of the oil pressure shock absorber 2 according to the preset conditions, and project the end joint 3 of the oil pressure shock absorber into the same feature point in the xy horizontal plane; The joint at the lower end of the oil shock absorber 2 is kept fixed, and the joint at the upper end of the oil shock absorber 2 is moved longitudinally and transversely along with the vehicle respectively; Connect the position of the joint 3 at the end of the oil pressure shock absorber to obtain the stretched length of the oil pressure shock absorber 2 in the xy horizontal plane; The joint 3 at the end of the hydraulic shock absorber is projected into the yz horizontal plane, and the stretched length of the hydraulic shock absorber 2 in the xy horizontal plane is accumulated while performing point motion in the yz horizontal plane to obtain the maximum stretched length of the hydraulic shock absorber 2.

[0040] The joint 3 at the end of the hydraulic shock absorber is projected into the yz horizontal plane, and the stretched length of the hydraulic shock absorber 2 in the xy horizontal plane is accumulated while performing point motion in the yz horizontal plane, and the maximum stretched length of the hydraulic shock absorber 2 is obtained, including: Projecting a line segment of a preset length on the end joint 3 of the oil pressure shock absorber in the yz horizontal plane; Keep the joint at the lower end of the oil shock absorber 2 fixed, and move the joint at the upper end of the oil shock absorber 2 vertically; Combined with the stretching length of the upper joint of the oil shock absorber 2 in the xy horizontal plane, the maximum stretching length of the oil shock absorber 2 is obtained by two-dimensional vector superposition.

[0041] When the oil pressure shock absorber 2 moves in the vertical direction, the length of the oil pressure shock absorber 2 at this time is the minimum compression length.

[0042] The joint deflection angle and joint torsion angle of the end joint 3 of the oil pressure shock absorber when it moves in the longitudinal, transverse and vertical directions respectively.

[0043] The calculation of the joint deflection angle and the joint torsion angle of the end joint 3 of the oil pressure shock absorber when the joint moves longitudinally, transversely and vertically respectively includes: Determine the corresponding relationship between the movement direction of the oil pressure shock absorber 2 and the joint deflection and the joint torsion based on the installation parameters of the oil pressure shock absorber 2; When the joint 3 at the end of the oil shock absorber is oriented parallel to the longitudinal direction, the oil shock absorber 2 is moved downward in the longitudinal direction and vertical direction in sequence. At this time, the joint 3 at the end of the oil shock absorber is in a deflected state, and the maximum joint deflection angle of the oil shock absorber 2 is generated; When the oil shock absorber 2 moves downward in the lateral direction and the vertical direction in sequence, the joint 3 at the end of the oil shock absorber is in a torsion state, and a maximum joint torsion angle of the oil shock absorber 2 is generated.

[0044] It should be noted that for the deflection and torsion angle of the end joint of the shock absorber, the corresponding relationship between the movement direction of the shock absorber and the deflection or torsion of the joint is determined according to the installation position of the joint. Assuming that the end joint is parallel to the x-longitudinal direction, when the shock absorber moves a along the x-longitudinal direction and c along the z-vertical downward direction, the end joint of the shock absorber is deflected, and the maximum deflection angle is α. Similarly, when the shock absorber moves b along the y-lateral direction and c along the z-vertical downward direction, the end joint of the shock absorber is torsion, and the maximum torsion angle is β.

[0045] like Figure 3-Figure 4 As shown, the method for checking the stroke and rotation angle of the shock absorber for rail transit provided by the present invention is further described below in conjunction with specific embodiments: (1) According to the design plan of rail transit vehicles, the motion center of the bogie is point O, and a spatial coordinate system (x-longitudinal, y-lateral, z-vertical) is established. The vertical hydraulic shock absorber is placed completely vertically without an inclination angle. The distance from point O is (500mm, 700mm), and the installation length is 400mm. According to the various limit stops of the bogie, the upper joint of the shock absorber can run 50mm, 40mm, and 80mm along the x-longitudinal, y-lateral, and z-vertical directions, respectively.

[0046] (2) Project the three-dimensional spatial positions of the upper and lower joints of the shock absorber relative to the center of the bogie onto the xy plane and yz plane respectively; in the xy horizontal plane, the projection of the upper and lower joints of the shock absorber is (500 mm, 700 mm). The lower joint of the shock absorber remains stationary, and the upper joint moves 50 mm along the x-longitudinal direction and 40 mm along the y-lateral direction with the vehicle. At this time, the positions of the upper and lower joint points on the connecting line can be obtained, and the stretched length of the shock absorber in the xy plane is L xy =64mm.

[0047] (3) Similarly, in the yz plane, the projections of the upper and lower joints of the shock absorber can be connected to form a line segment with a length of L = 400 mm. The lower joint of the shock absorber remains stationary, and the upper joint moves 80 mm along the z-vertical direction. At the same time, consider that the upper joint moves L in the xy plane. xy =64mm displacement, the maximum stretching length L of the shock absorber can be obtained by superposition of two-dimensional vectors. max =484.2mm. When the shock absorber moves only 80mm downward along the z-vertical direction, the length of the shock absorber is at its minimum state, i.e., L min =320mm.

[0048] (4) Targeting Figure 2As shown in the installation position of the vertical shock absorber end joint, when the shock absorber moves 50mm along the x-longitudinal direction and 80mm downward along the z-vertical direction, the end joint of the shock absorber shows deflection, and the maximum deflection angle α is 8.9°; similarly, when the shock absorber moves 40mm along the y-lateral direction and 80mm downward along the z-vertical direction, the end joint of the shock absorber corresponds to torsion, and the maximum torsion angle β is 7.1°.

[0049] To sum up, with the help of the above-mentioned technical scheme of the present invention, the present invention uses two-dimensional drawing software to convert the spatial relative position of the vehicle and the shock absorber into a two-dimensional plane point projection, and converts the relative motion between the two into a plane line motion, which can directly and accurately calculate the shock absorber limit stroke and the joint limit deflection angle and torsion angle; the verification method provided by the present invention is suitable for shock absorber stroke verification of different installation positions, such as lateral shock absorbers, vertical shock absorbers and anti-snaking shock absorbers. Compared with the method of using a three-dimensional model to perform spatial motion to achieve stroke verification, the two-dimensional verification method that converts spatial relative motion into relative motion between plane points can greatly reduce the time for establishing a solid model and improve the efficiency of stroke verification; the accurate shock absorber stroke and joint deflection and torsion angle verification calculation proposed by the present invention can be directly used as the technical input requirement for the performance selection and design of hydraulic shock absorbers, avoiding the problems of shock absorber design difficulties and long cycles caused by unclear requirements, and also helps the overall design of rail vehicle bogies.

[0050] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for calibrating the travel and rotation angle of a shock absorber for rail transit, characterized in that: The verification method of the travel and rotation angle of the rail transit shock absorber includes: Acquire installation parameters of the oil pressure shock absorber, and determine actual operating conditions of the oil pressure shock absorber based on the installation parameters of the oil pressure shock absorber; A three-dimensional coordinate system is established with the vehicle's motion center as the reference point, and the spatial relative positions of the hydraulic shock absorber end joints are projected onto a two-dimensional plane; The three-dimensional motion of the oil pressure shock absorber relative to the vehicle motion center is sequentially converted into the two-dimensional characteristic point motion on each projection surface in the two-dimensional plane; The motion of the two-dimensional feature points on each projection surface is accumulated and checked to obtain the motion displacement of the hydraulic shock absorber, so as to realize the stroke and rotation angle verification of the hydraulic shock absorber.

2. A method for calibrating the travel and rotation angle of a rail transit shock absorber according to claim 1, characterized in that: The oil shock absorber stroke and rotation angle include the maximum stretching length, minimum compression length, joint deflection angle and joint torsion angle of the oil shock absorber.

3. A method for calibrating the travel and rotation angle of a rail transit shock absorber according to claim 2, characterized in that: The end joints of the oil pressure shock absorber include an upper end joint of the oil pressure shock absorber and a lower end joint of the oil pressure shock absorber.

4. A method for calibrating the travel and rotation angle of a rail transit shock absorber according to claim 3, characterized in that: The method of establishing a three-dimensional coordinate system with the vehicle motion center as a reference point and projecting the spatial relative position of the end joint of the hydraulic shock absorber onto a two-dimensional plane includes: A three-dimensional space coordinate system is established by taking the vehicle motion center of the oil pressure shock absorber relative to the vehicle bogie as a reference point; When the lower joint of the oil shock absorber is kept fixed, the limit displacement of the upper joint of the oil shock absorber relative to the vehicle's motion center is analyzed; The spatial relative position of the end joint of the oil shock absorber with respect to the vehicle's motion center is projected onto the xy horizontal plane and the yz horizontal plane respectively.

5. A method for calibrating the travel and rotation angle of a rail transit shock absorber according to claim 4, characterized in that: The limit displacement of the upper joint of the oil shock absorber relative to the vehicle's motion center is the maximum displacement of the upper joint of the oil shock absorber relative to the vehicle's motion center along the longitudinal, transverse and vertical directions respectively.

6. A method for calibrating the travel and rotation angle of a rail transit shock absorber according to claim 5, characterized in that: The motion displacement expression of the oil pressure shock absorber obtained by accumulating and checking the motion of the two-dimensional feature points on each projection surface includes: Calculate the maximum stretching length of the oil shock absorber in the xy horizontal plane and the yz horizontal plane; calculate the minimum compression length based on the actual operating conditions of the oil shock absorber; Calculate the joint deflection angle and joint torsion angle of the end joint of the hydraulic shock absorber when it moves longitudinally, transversely and vertically respectively.

7. A method for calibrating the travel and rotation angle of a rail transit shock absorber according to claim 6, characterized in that: The calculation of the maximum stretching length of the oil shock absorber in the xy horizontal plane and the yz horizontal plane includes: Adjust the placement of the oil shock absorber according to the preset conditions, and project the end joints of the oil shock absorber into the same feature points in the xy horizontal plane; Keep the joint at the lower end of the oil shock absorber fixed, and move the joint at the upper end of the oil shock absorber along the longitudinal and transverse directions of the vehicle; Connect the joint positions of the ends of the oil shock absorber to obtain the stretched length of the oil shock absorber in the xy horizontal plane; The end joint of the hydraulic shock absorber is projected into the yz horizontal plane, and the stretched length of the hydraulic shock absorber in the xy horizontal plane is accumulated while performing point motion in the yz horizontal plane to obtain the maximum stretched length of the hydraulic shock absorber.

8. A method for checking the stroke and rotation angle of a rail transit shock absorber according to claim 7, characterized in that: The projecting of the end joint of the hydraulic shock absorber into the yz horizontal plane, performing point motion in the yz horizontal plane and accumulating the stretched length of the hydraulic shock absorber in the xy horizontal plane to obtain the maximum stretched length of the hydraulic shock absorber includes: Project a line segment of a preset length on the end joint of the oil pressure shock absorber in the yz horizontal plane; Keep the lower joint of the hydraulic shock absorber fixed, and move the upper joint of the hydraulic shock absorber vertically; Combined with the stretching length of the upper joint of the hydraulic shock absorber in the xy horizontal plane, the maximum stretching length of the hydraulic shock absorber is obtained by two-dimensional vector superposition.

9. A method for calibrating the travel and rotation angle of a rail transit shock absorber according to claim 8, characterized in that: When the oil pressure shock absorber moves in the vertical direction, the length of the oil pressure shock absorber at this time is the minimum compression length.

10. A method for calibrating the travel and rotation angle of a rail transit shock absorber according to claim 9, characterized in that: The calculation of the joint deflection angle and the joint torsion angle of the end joint of the oil pressure shock absorber when the end joint moves longitudinally, transversely and vertically respectively includes: Based on the installation parameters of the oil pressure shock absorber, the corresponding relationship between the movement direction of the oil pressure shock absorber and the joint deflection and the joint torsion is determined; When the joint at the end of the oil shock absorber is oriented parallel to the longitudinal direction, the oil shock absorber is moved downward in the longitudinal direction and vertical direction in sequence. At this time, the joint at the end of the oil shock absorber is in a deflected state, and the maximum joint deflection angle of the oil shock absorber is generated; When the oil shock absorber moves downward in the lateral and vertical directions in turn, the end joints of the oil shock absorber are in a torsion state, and a maximum joint torsion angle of the oil shock absorber is generated.

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