Rapid calculation method for lifting amount and gear-shifting force of automobile door

Abstract

The invention discloses a method for rapidly calculating the lifting amount and the gear-shifting force of an automobile door. The method comprises the steps that S1, the hinge axis position of an automobile door system is determined; s2, the barycentric coordinate position of the vehicle door system is determined, and the lifting amount of the vehicle door system is calculated; s3, component force, a centripetal force arm and a centripetal moment of a gravity vertical hinge axis of the vehicle door system under different opening angles are calculated; s4, calculating the flat ground function torque of each gear of the limiter; and S5, evaluating the hill-holding performance of the vehicle door system. According to the rapid calculation method for the lifting amount and the gear-shifting force of the automobile door, when any parameter of the hinge axis position or the axis inclination angle, the automobile door gravity center position or the weight, the gear angle and the theoretical opening force value changes, the lifting amount and the gear-shifting force are calculated; the method can quickly calculate the flat ground function torque of each gear of the limiter corresponding to a theoretical handle operating force value and judge whether the slope holding performance of a 20% slope (upward / downward inclination of a vehicle head) and a 10% slope (left / right inclination) meets the requirements or not, and improves the calculation efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of automobiles, and in particular to a method for quickly calculating the lifting amount and shifting force of an automobile door. Background Art

[0002] The operating comfort of car doors is receiving more and more attention from users. Reasonable arrangement of door hinge axis, appropriate door lift and shift force are key design elements.

[0003] During the development of the door system, it is necessary to set system development goals, and the theoretical handle operating force value is one of them (usually the external opening handle operating force value is the design target, and the corresponding internal opening handle operating force value can be converted through torque balance). When the theoretical handle operating force target is set, it is necessary to calculate the ground functional torque of each gear of the limiter according to the layout parameters of the door system, such as the center of gravity coordinate position, the weight of the door system, the centripetal torque of the door system at different gear angles, the hinge friction torque, etc. (that is, when the actual shift torque measurement value of the limiter is consistent with the theoretically calculated functional torque of each gear, the actual handle operating force value is the theoretical handle operating force value), and then evaluate whether the hill-holding performance is met at a slope of 20% (the front of the vehicle is tilted up / down) and a slope of 10% (tilted to the left / right) based on the ground functional torque of each gear of the limiter. If hill-holding is feasible, the development target requirements are met; if hill-holding is not feasible, it is necessary to increase the theoretical handle operating force value (the operating comfort deteriorates but does not affect the arrangement of system accessories) or optimize the door system layout (adjust the hinge inclination angle, etc., which does not affect the operating comfort but affects the arrangement of system accessories).

[0004] At each stage of data design release, the arrangement of the hinge axis, the position and weight of the center of gravity of the door system, the setting of the gear angle, etc. may change. When a certain parameter changes, the limiter torque corresponding to the theoretical handle operating force value will change. The hill-holding performance of 20% slope (front of the vehicle tilted up / down) and 10% slope (left / right tilt) needs to be re-evaluated, which requires large amount of calculation and low efficiency.

[0005] It is hoped to provide an improved method for quickly calculating the lift amount and shift force of a vehicle door, particularly with regard to how to improve the calculation efficiency. Summary of the invention

[0006] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a method for quickly calculating the lifting amount and shifting force of a vehicle door, the purpose of which is to improve the calculation efficiency.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is: a method for quickly calculating the lifting amount and shifting force of a car door, comprising the steps of:

[0008] S1. Determine the position of the hinge axis of the door system;

[0009] S2, determining the coordinate position of the center of gravity of the door system and calculating the lifting amount of the door system;

[0010] S3. Calculate the force component, centripetal force arm and centripetal moment of the door system at different opening angles.

[0011] S4. Calculate the ground function torque of each gear of the limiter;

[0012] S5. Evaluate the hill-holding performance of the door system.

[0013] In step S1, when the inward inclination angle of the hinge axis is θ, the normal vector is the first vector (0, cosθ, -sinθ); when the backward inclination angle of the hinge axis is δ, the normal vector is the second vector (cosδ, 0, -sinδ); when the hinge axis is inclined inward and forward or backward at the same time, the direction vector of the hinge axis is the cross product of the first vector and the second vector; when the set position point and direction vector passed by the hinge axis are determined, the position of the hinge axis is determined.

[0014] In the step S1, the coordinates of the projection point of the origin of the coordinate system of the whole vehicle on the hinge axis are calculated, the vector a from the set position point to the origin and the hinge axis direction vector b are calculated, the projection of vector a on vector b is recorded as vector c, and the modulus of vector c is the dot product of vector a and vector b.

[0015] In step S2, after inputting the coordinate position data of the center of gravity of the door system, coordinate transformation is first used to move the hinge axis to a position passing through the coordinate origin, and the coordinates of the center of gravity of the door system are moved in the same way; then the Rodrigo rotation formula is used to obtain the coordinates of the center of gravity of the door system after it is rotated a certain angle around the hinge axis after it is moved; finally, coordinate transformation is performed again to move the obtained coordinates of the center of gravity of the door system after it is rotated a certain angle back to the original position, that is, the coordinate position of the center of gravity of the door system after it is rotated a certain angle around the hinge axis in the vehicle coordinate system.

[0016] The step S3 comprises:

[0017] S301, setting the center of gravity of the door system after rotation as a first position point, calculating the coordinates of a projection point of the first position point on the hinge axis, that is, obtaining the coordinates of the first projection point;

[0018] S302, setting the gravity end point of the center of gravity of the door system after rotation as a second position point, calculating the coordinates of the projection point of the second position point on the hinge axis, that is, obtaining the coordinates of the second projection point;

[0019] S303, calculating the coordinates of the third position point and the component force F of the gravity perpendicular to the hinge axis;

[0020] S304, calculating an angle α between a line connecting the second projection point and the third position point and a line connecting the second position point and the third position point;

[0021] S305: Calculate the centripetal arm L and centripetal moment M of the door system 向心 .

[0022] In the step S303, the coordinate difference between the first projection point and the first position point is calculated, including the coordinate difference Δx in the X direction, the coordinate difference Δy in the Y direction, and the coordinate difference Δz in the Z direction.

[0023] In step S305, the centripetal force arm L=(Δx 2 +Δy 2 +Δz 2 ) 0.5 ·sinɑ, the centripetal moment M 向心 =F·L.

[0024] In step S304, cosɑ is obtained according to the vector dot product formula d·e=|d||e|cosɑ, where vector d is the vector from the third position point to the second projection point, and vector e is the vector from the second position point to the third position point; finally, according to the formula sinɑ=(1-cosɑ 2 ) 0.5 , and obtain sinɑ.

[0025] In step S4, according to formula M 开启 =M 限位器 +M 铰链 +M 向心 and formula M 关闭 =M 限位器 +M 铰链 -M 向心 , the ground function torque of each gear of the limiter is obtained, that is, when the measured torque and the calculated torque of the limiter are equal, the actual handle operating force value is the theoretical handle operating force value.

[0026] The method for quickly calculating the lifting amount and shifting force of a car door of the present invention can quickly calculate the ground-leveling function torque of each gear of the limiter corresponding to the theoretical handle operating force value and judge whether the hill-holding performance of a 20% slope (the front of the vehicle tilts upward / downward) and a 10% slope (tilted to the left / right) meets the requirements when any parameter of the hinge axis position or axis inclination angle, the door center of gravity position or weight, the gear angle, and the theoretical opening force value changes, thereby improving the calculation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic diagram of a calculation model of the present invention;

[0028] Figure 2 is a schematic diagram of the evaluation of the slope-staying performance of the present invention;

[0029] Figure 3 and Figure 4 It is a calculation schematic diagram of the present invention;

[0030] The marks in the above figures are: 5, center of gravity coordinates; 6, hinge axis; 7, first position point; 8, second position point; 9, first projection point; 10, second projection point; 11, third position point; 12, translation line. DETAILED DESCRIPTION

[0031] To facilitate understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. Several embodiments of the present invention are given in the drawings, but the present invention can be implemented in different forms and is not limited to the embodiments described in the text. On the contrary, these embodiments are provided to make the content disclosed in the present invention more thorough and comprehensive.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly connected by technicians in the technical field to which the present invention belongs. The terminology used in the specification of the present invention is for the purpose of describing specific embodiments and is not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0033] like Figures 1 to 4 As shown, the present invention provides a method for quickly calculating the lifting amount and shift force of a car door, comprising the following steps:

[0034] S1. Determine the position of the hinge axis of the door system;

[0035] S2. Calculate the lifting amount of the door system;

[0036] S3. Calculate the force component, centripetal force arm and centripetal moment of the door system at different opening angles.

[0037] S4. Calculate the ground function torque of each gear of the limiter;

[0038] S5. Evaluate the hill-holding performance of the door system.

[0039] Specifically, the present invention provides a rapid design method. When any parameter of the hinge axis position or axis inclination, the door center of gravity position or weight, gear angle, and theoretical opening force value changes, the ground-level function torque of each gear of the limiter corresponding to the theoretical handle operation force value can be quickly calculated, and it can be judged whether the slope holding performance of 20% slope (the front of the car is tilted upward / downward) and 10% slope (the car is tilted to the left / right) meets the requirements, thereby improving the calculation efficiency. The door system is installed on the vehicle body through the door hinge, and the hinge axis is the rotation center line of the door system when it is opened and closed. The function of the limiter is to limit the degree of opening of the door system. On the one hand, it limits the maximum opening of the door system, and on the other hand, it can keep the door system in an open state when needed to prevent the door system from suddenly closing under the action of external force and causing personal injury.

[0040] In the above step S1, when the hinge axis inwardly tilts at an angle of θ, the normal vector is the first vector (0, cosθ, -sinθ); when the hinge axis backwardly tilts at an angle of δ, the normal vector is the second vector (cosδ, 0, -sinδ); the hinge axis forwardly tilts at an angle of -δ, which is opposite to the backward tilt direction. When the hinge axis is both inwardly tilted and forwardly tilted or backwardly tilted at the same time, the direction vector of the hinge axis is the cross product of the first vector and the second vector, that is: (-cosθsinδ, -cosδsinθ, -cosδcosθ); when the set position point (x, y, z) and the direction vector through which the hinge axis passes are determined, the position of the hinge axis is determined.

[0041] The set position point is located on the hinge axis. In the above step S1, the coordinates of the projection point of the coordinate origin of the whole vehicle coordinate system on the hinge axis are calculated, and the vector a from the set position point to the coordinate origin and the hinge axis direction vector b are calculated. The projection of vector a on vector b is recorded as vector c, then the modulus of vector c is the dot product of vector a and vector b, and the vector from the projection point of the coordinate origin on the hinge axis to the coordinate origin is ac.

[0042] In the above step S2, by inputting the coordinate position data of the center of gravity of the door system, the center of gravity of the door system and the hinge axis are in the original positions. First, coordinate transformation is used to move the hinge axis to the position passing through the coordinate origin of the whole vehicle coordinate system, so that the coordinate origin is on the hinge axis after the position is moved. The center of gravity of the door system and the hinge axis make the same movement to obtain the coordinates of the center of gravity of the door system after the movement. In this process, the hinge axis moves parallel to the position passing through the coordinate origin, and the center of gravity coordinates also make relative translation, and the relative position between the center of gravity coordinates and the hinge axis remains unchanged; then the Rodrigo rotation formula is used to obtain the center of gravity of the door system after the movement, and the center of gravity of the door system rotates around the hinge axis after the position is moved by a certain angle (set as the set angle) to obtain the center of gravity coordinates of the door system after the rotation by a certain angle; finally, coordinate transformation is performed again to move the center of gravity of the door system after the rotation by a certain angle back to the original position. The center of gravity coordinates of the door system obtained at this time are the coordinate positions of the center of gravity of the door system after the rotation by a certain angle around the hinge axis in the whole vehicle coordinate system.

[0043] Similarly, in the above step S2, by inputting the coordinate position data of the measuring point on the door system, the measuring point is in the original position, and the coordinate transformation is first used to move the hinge axis to the position passing through the coordinate origin of the whole vehicle coordinate system, so that the coordinate origin is on the hinge axis after the position is moved, and the measuring point and the hinge axis make the same movement to obtain the coordinates of the moving measuring point. In this process, the hinge axis moves parallel to the position passing through the coordinate origin, and the coordinates of the measuring point also make a relative translation, and the relative position between the measuring point and the hinge axis remains unchanged; then the Rodriguez rotation formula is used to obtain the measurement point after the movement. Rotate a certain angle around the hinge axis after the position is moved to obtain the coordinates of the measurement point after the rotation; finally, coordinate transformation is performed again to move the obtained measurement point after the rotation of a certain angle back to the original position. The measurement point coordinates obtained at this time are the coordinate positions of the measurement point after the rotation of a certain angle around the hinge axis in the whole vehicle coordinate system, and the final measurement point coordinate positions are determined.

[0044] The measuring point is a position point selected on the car door. The position of the measuring point is generally located at the rear end of the car door (the front end of the car door is rotatably connected to the car body through the door hinge, and the rear end of the door is located at the end of the car door away from the door hinge). The coordinate position can be set. It mainly examines the lifting amount of the rear end when the car door is opened to the maximum angle. If the lifting amount is too small, it is easy to hit the curb when opening. The lifting amount needs to be within a reasonable range.

[0045] In the above step S2, the coordinates of the center of gravity after rotating around the hinge axis at any angle can be quickly obtained by coordinate transformation and using the Rodriguez rotation formula. The coordinates of the measuring points can be calculated in the same way to obtain the coordinates of the measuring points on the door system after rotating at a certain angle, and finally the lifting amount of the door system is calculated. The lifting amount of the door system is the coordinate difference in the Z-axis direction between the measuring point of the door system after rotating at a certain angle and the measuring point at the original position.

[0046] In the above step S3, the vector formula is used to obtain the component of gravity perpendicular to the hinge axis (this component determines the influence of gravity on the hinge rotation), the centripetal force arm and the centripetal moment at different opening angles. When arranging the hinge, it is necessary to consider that the door has a tendency to close by itself. The hinge axis needs to have a certain inward angle, and the gravity of the door system will generate a centripetal force. The gravity of the door system can be decomposed into a component parallel to the hinge axis and a component perpendicular to the hinge axis. The component parallel to the hinge axis does not generate a moment, and the component perpendicular to the hinge axis generates a centripetal moment M. 向心 .

[0047] The above step S3 includes:

[0048] S301, setting the center of gravity of the door system after being rotated by a certain angle as a first position point, calculating the coordinates of a projection point of the first position point on the hinge axis, the projection point of the first position point on the hinge axis is the first projection point, that is, obtaining the coordinates of the first projection point;

[0049] S302, setting the gravity end point of the center of gravity of the door system after rotating by a certain angle as the second position point, calculating the coordinates of the projection point of the second position point on the hinge axis, the projection point of the second position point on the hinge axis is the second projection point, that is, obtaining the coordinates of the second projection point;

[0050] S303, calculating the coordinates of a third position point (the third position point is a projection point from the second position point to a straight line passing through the first position point and parallel to the hinge axis) and the component force F of gravity perpendicular to the hinge axis;

[0051] S304, calculating an angle α between a line connecting the second projection point and the third position point and a line connecting the second position point and the third position point;

[0052] S305: Calculate the centripetal arm L and centripetal moment M of the door system 向心 .

[0053] In the above step S302, if Figure 4As shown, the gravity end point and the center of gravity of the door system after rotation at a certain angle are located in the same gravity direction of the door system, and the gravity end point is located below the center of gravity of the door system after rotation at a certain angle, that is, a straight line is drawn downward along the Z-axis direction through the center of gravity of the door system after rotation at a certain angle, and a point is taken on the straight line, that is, the gravity end point, so that the distance from the gravity end point to the center of gravity after rotation at a certain angle is equal to the gravity of the door system.

[0054] In the above step S303, the third position point is the gravity end point of the center of gravity of the door system after rotating by a certain angle on the auxiliary line ( Figure 4 The projection point on the dotted line in the figure, the auxiliary line is parallel to the hinge axis, and the center of gravity of the door system after rotating a certain angle is located on the auxiliary line. The coordinate relationship between the first projection point and the first position point is the same as the coordinate relationship between the second projection point and the third position point. The coordinates of the third position point can be obtained from the coordinates of the second projection point. The coordinates of the second position point are known, and the straight-line distance between the second position point and the third position point is the component of gravity perpendicular to the hinge axis, which is also the centripetal force.

[0055] In the above step S303, the coordinate difference between the first projection point and the first position point is calculated, including the coordinate difference Δx in the X-axis direction, the coordinate difference Δy in the Y-axis direction, and the coordinate difference Δz in the Z-axis direction.

[0056] In the above step S304, cosɑ is obtained according to the vector dot product formula d·e=|d||e|cosɑ, where vector d is the vector from the third position point to the second projection point, and vector e is the vector from the second position point to the third position point; finally, according to the formula sinɑ=(1-cosɑ 2 ) 0.5 , and obtain sinɑ.

[0057] In the above step S305, the centripetal force arm L=(Δx 2 +Δy 2 +Δz 2 ) 0.5 ·sinɑ, centripetal moment M 向心 =F·L.

[0058] In the above step S4, according to formula M 开启 =M 限位器 +M 铰链 +M 向心 and formula M 关闭 =M 限位器 +M 铰链 -M 向心 , the ground function torque of each gear of the limiter is obtained, that is, when the measured torque and the calculated torque of the limiter are equal, the actual handle operating force value is the theoretical handle operating force value.

[0059] During the door system development process, it is necessary to set system development goals, and the theoretical handle operating force value is one of them. The theoretical handle operating force value is also the shift force.

[0060] In the door opening condition when the door system is open, Figure 1 The 1 in the formula represents the opening force F, i.e. the door opening torque M. 开启 , 2 represents the limiter resistance moment M 限位器 , 3 represents the centripetal resistance moment M 向心 , 4 represents the hinge resistance moment M 铰链 , the torque balance relationship is M 开启 =M 限位器 +M 铰链 +M 向心 In the door closing condition when the door system is closed, Figure 1 The 1 in the figure represents the closing force F, i.e. the closing torque M. 关闭 , 2 represents the limiter resistance moment M 限位器 , 3 represents the centripetal assist moment M 向心 , 4 represents the hinge resistance moment M 铰链 , the torque balance relationship is M 关闭 =M 限位器 +M 铰链 -M 向心 .

[0061] In the above step S5, the hill-holding performance when the front of the vehicle tilts upward or downward with a slope of 20% and the hill-holding performance when the vehicle tilts to the left or right with a slope of 10% are determined.

[0062] When the front of the car is tilted upward at a slope of 20%, at the opening force peak position (the corresponding door opening angle is consistent with the set angle of the center of gravity rotation in step S2), the centripetal force generates a centripetal torque, which is the closing direction of the door system, so the hill-holding performance does not need to be considered.

[0063] When the front of the car is tilted downward at a slope of 20%, at the opening force peak position (the corresponding door opening angle is consistent with the set angle of the center of gravity rotation in step S2), for this model, the centripetal force at this time produces a centripetal torque, which is the closing direction of the door system, so there is no problem with the hill-holding performance.

[0064] When the door opening angle increases, the torque generated by the component force of gravity perpendicular to the hinge axis gradually changes from the door closing direction to the door opening direction, so it is necessary to evaluate the hill holding performance of outward opening one (corresponding to the first gear state after the door is opened), outward opening two (corresponding to the second gear state after the door is opened), and outward opening three (corresponding to the third gear state after the door is opened).

[0065] When the front of the car tilts to the right with a slope of 10%, at the opening force peak position (the corresponding door opening angle is consistent with the set angle of center of gravity rotation in step S2), the centripetal force generates a centripetal torque, which is the closing direction of the door system, so the hill-holding performance does not need to be considered.

[0066] Figure 2 This is a schematic diagram for evaluating hill-holding performance; when the front of the vehicle tilts up / down at a slope of 20%, the door must be able to remain open in each gear position; when the left / right side tilts at a slope of 10%, it is recommended that the door be able to remain open in each gear position.

[0067] The method for quickly calculating the lifting amount and shifting force of a vehicle door of the present invention has the following advantages:

[0068] 1. Input the coordinates and inclination angle of the hinge passing point, the center of gravity and weight parameters of the door, and quickly calculate the door's lifting amount, centripetal moment and gravitational potential energy;

[0069] 2. Input the gear angle and theoretical handlebar operating force value, input the coordinates of the force application points of the inner and outer handlebars, quickly calculate the flat ground function torque of the corresponding limiter, and automatically determine whether the hill-holding performance of a 20% slope (the front of the vehicle tilts up / down) and a 10% slope (tilted to the left / right) meets the requirements;

[0070] 3. High computational efficiency;

[0071] Example

[0072] Taking a certain vehicle model as an example, the coordinates of the set position point through which the hinge axis passes are (558.959, -909.181, 434.958), the inclination angle of the hinge axis is 2° (the angle between the hinge axis and the ZX plane in the vehicle coordinates), and the rearward tilt angle of the hinge axis is 1° (the angle between the hinge axis and the YZ plane in the vehicle coordinates).

[0073] In step S1, the coordinates of the projection point of the coordinate origin of the whole vehicle coordinate system on the hinge axis are first calculated;

[0074] like Figure 3 As shown, the vector from the position point to the origin is set to (-558.959, 909.181, -434.958), which is recorded as vector a.

[0075] The hinge axis direction vector (-cos2°sin1°, -cos1°sin2°, -cos1°cos2°) is denoted as vector b.

[0076] The projection of vector a on vector b is denoted as vector c. Then the magnitude of c is the dot product of vector a and vector b. That is:

[0077] ab=(-558.959)·(-cos2°sin1°)+909.181·(-cos1°sin2°)+(-434.958)·(-cos1°cos2°)=412.651;

[0078] Vector c is (-412.651·cos2°sin1°, -412.651·cos1°sin2°, -412.651·cos1°cos2°), which is (-7.197, -14.399, -412.337).

[0079] The vector from the coordinate origin to the projection point of the hinge axis to the origin is ac = (-558.959 + 7.197, 909.181 + 14.399, -434.958 + 412.337) = (-551.762, 923.580, -22.621), so the coordinates of the projection point of the coordinate origin on the hinge axis are (551.762, -923.580, 22.621).

[0080] In step S2, the coordinates of the center of gravity after rotating around the hinge axis by a certain angle and the lifting amount of the door system are calculated.

[0081] Rodriguez rotation formula: Assume that we want to rotate point P (x, y, z) around vector V (a, b, c) with a rotation angle of θ. Then the new coordinates of point P after rotation around the axis can be expressed by the following formula:

[0082] P ’ =Pcosθ+(V╳P)sinθ+V(VP)(1-cosθ)

[0083] Among them, ╳ represents the cross product of vectors, and . represents the dot product of vectors.

[0084] Since the center of gravity coordinates and the hinge axis are in the vehicle coordinates, the hinge axis needs to be translated to the origin, and the center of gravity coordinates also need to be translated in the same way.

[0085] The coordinates of the center of gravity of the vehicle model are (1071.307, -813.955, 439.784). From step S1, the coordinates of the projection point of the coordinate origin of the vehicle coordinate system on the hinge axis are known. The center of gravity is transformed to obtain the coordinates of the center of gravity point P after the movement (519.545, 109.625, 417.163). The coordinates of the center of gravity after the movement are rotated around the hinge axis after the position is moved by a certain angle (for example, 16.5°, which corresponds to the peak value of the opening force). ’ The coordinates are:

[0086] P ’ X=519.545·cos16.5°+((-cos1°sin2°)·417.163-109.625·(-cos1°cos2°))

[0087] ·sin16.5°+(-cos2°sin1°)·((519.545·(-cos2°sin1°))+109.625·(-cos1°sin2°)+417.163·(-cos1°cos2°))·(1-cos16.5°)=525.436;

[0088] P ’ Y =109.625·cos16.5°-((-cos2°sin1°)·417.163-519.545·(-cos1°cos2°))

[0089] ·sin16.5°+(-cos1°sin2°)·((519.545·(-cos2°sin1°))+109.625·(-cos1°sin2°)+417.163·(-cos1°cos2°))·(1-cos16.5°)=-39.652;

[0090] P ’ Z =417.163·cos16.5°+((-cos2°sin1°)·109.625-519.545·(-cos1°sin2°))

[0091] ·sin16.5°+(-cos1°cos2°)·((519.545·(-cos2°sin1°))+109.625·(-cos1°sin2°)+417.163·(-cos1°cos2°))·(1-cos16.5°)=422.273;

[0092] Then the P obtained above is ’ Point coordinates (P ’ X , P ’ Y , P ’ Z ), perform coordinate transformation again, transform the coordinates back, and get P ’ 2 The point coordinates are (525.436+551.762, -39.652-923.580, 422.273+22.621), which is (1077.198, -963.232, 444.894). ’2 The point coordinates are the coordinate positions of the door system's center of gravity after rotating around the hinge axis by a certain angle (eg, 16.5°) in the vehicle coordinates.

[0093] Through the above coordinate transformation and Rodriguez rotation formula, the coordinates of the center of gravity after rotating around the hinge axis at any angle can be quickly obtained. The coordinates of the measuring point can be calculated in the same way to obtain the coordinates of the measuring point on the door system after rotating at a certain angle, and finally the lifting amount of the door system is calculated. The lifting amount of the door system is the coordinate difference in the Z-axis direction between the measuring point of the door system after rotating at a certain angle and the measuring point at the original position.

[0094] In step S3 , the centripetal force and centripetal moment of the door system at different opening angles are calculated.

[0095] When arranging hinges, it is necessary to consider that the door has a tendency to close by itself. The hinge axis needs to have a certain inward inclination angle, and the gravity of the door will generate a centripetal force. The gravity of the door can be decomposed into a force component parallel to the hinge axis and a force component perpendicular to the hinge axis. The force component parallel to the hinge axis does not generate a moment, and the force component perpendicular to the hinge axis generates a centripetal moment Mcentripetal.

[0096] In this embodiment, the weight of the front door of the vehicle door system is 36.735 kg, and the gravity on the door system is 36.735·9.8=360.003 N. Figure 4 As shown, taking the door opening 16.5° as an example (the coordinates of the center of gravity after rotating 16.5° around the hinge axis have been calculated in step S2 (1077.198, -963.232, 444.894)), a straight line in the Z direction is made downward through the center of gravity coordinates after the rotation, and the length of the straight line is 360.003 mm, then the coordinates of the end point of the center of gravity are (1077.198, -963.232, 444.894-360.003), that is, (1077.198, -963.232, 84.891).

[0097] The calculation idea is as follows:

[0098] ⑴ Find the coordinates of the projection point from the center of gravity to the hinge axis after rotating a certain angle, that is, the coordinates of the first projection point;

[0099] The coordinates of the projection point of the origin of the coordinate system on the original hinge axis can be obtained by using the relationship between vectors. The coordinates of the first projection point 1 are (559.257, -908.585, 452.026) and are calculated similarly to the method of calculating the coordinates of the projection point of the origin of the coordinate system on the original hinge axis in step S1.

[0100] (2) Find the coordinates of the projection point of the gravity end point of the center of gravity of the door system after rotation by a certain angle on the original hinge axis, that is, the coordinates of the second projection point;

[0101] The coordinates of the second projection point can be obtained by using the relationship between vectors, which is similar to the method of calculating the coordinates of the projection point of the coordinate origin on the original hinge axis in step S1. The details will not be repeated here. The coordinates of the second projection point are (552.983, -921.137, 92.571).

[0102] ⑶ The coordinate relationship between the first projection point and the first position point is the same as the coordinate relationship between the second projection point and the third position point. The coordinate difference between the first projection point and the first position point in the X direction is -517.941, the coordinate difference in the Y direction is 54.647, and the coordinate difference in the Z direction is 7.132.

[0103] The coordinates of the third point can be obtained from the coordinates of the second projection point: (1070.924, -975.784, 85.439). The coordinates of the second point are known. The straight-line distance between the second point and the third point is the component of gravity perpendicular to the hinge axis, which is also the centripetal force. It can be obtained according to the two-point coordinate formula, which is 14.044N.

[0104] (4) Find the angle ɑ, which is the angle between the line connecting the second projection point and the third position point and the line connecting the second position point and the third position point.

[0105] The vector d from the third position point to the second projection point is expressed as (552.983-1070.924, -921.137+975.784, 92.571-85.439), that is, (-517.941, 54.647, 7.132).

[0106] The vector e from the second position point to the third position point is expressed as (1070.924-1077.198, -975.784+963.232, 85.439-84.891), that is, (-6.274, -12.552, 0.548).

[0107] Using the vector dot product formula, d·e=|d||e|cosɑ, we can get cosɑ=(517.941·6.274-54.647·12.552+7.132·0.548) / ((517.941 2 +54.647 2 +7.132 2 ) 0.5 (6.274 2 +12.552 2 +0.548 2 ) 0.5 )=0.351.

[0108] sinɑ=(1-0.351 2 ) 0.5 =0.9364.

[0109] ⑸Calculate the centripetal force arm and centripetal moment;

[0110] Centripetal force arm L = (517.941 2 +54.647 2 +7.132 2 ) 0.5 ·sinɑ=487.721mm;

[0111] M 向心 =F·L=14.044·487.721 / 1000=6.850Nm.

[0112] In step S4, the limiter leveling function torque of each gear is calculated;

[0113] Assuming that the outward opening target value of the outward opening handle of the door system is 30N, the coordinates of the force point of the outward opening handle are (1367, -950, 620), and the coordinates of the force point of the inward opening handle of the door system are (1150, -716, 522). The coordinates of the projection point of the force point of the outward opening handle on the hinge axis and the coordinates of the projection point of the force point of the inward opening handle on the hinge axis can be calculated respectively, and the force arm of the outward opening handle is 806.103mm and the force arm of the inward opening handle is 619.195mm respectively.

[0114] The friction resistance torque of the handle is about 2N.m. According to the formula M 开启 =M 限位器 +M 铰链 +M 向心 , find M 限位器 =30·806.103 / 1000-2-6.850=15.333Nm, which is the ground function torque of the limiter corresponding to the external opening force value target, and the corresponding internal opening force F 内开一 for:

[0115] F 内开一 =(30·806.103 / 1000) / (619.195 / 1000)=39.056N.

[0116] In step S5, the hill-holding performance when the front of the vehicle is tilted upward / downward by 20% is determined;

[0117] When the front of the vehicle is tilted upward at a slope of 20%, at the opening force peak position (corresponding to the door opening position of 16.5°), the centripetal force generates a centripetal torque in the direction of door closing, so the hill-holding performance does not need to be considered.

[0118] When the front of the vehicle tilts downward at a slope of 20%, at the opening force peak position (corresponding to the door opening position of 16.5°), for this model, the centripetal force at this time produces a centripetal moment in the direction of door closing, so there is no problem with the hill-holding performance.

[0119] When the angle of 16.5° increases, the torque generated by the component of gravity perpendicular to the hinge axis gradually changes from the door closing direction to the door opening direction, so it is necessary to evaluate the slope retention performance of outward opening one, outward opening two, and outward opening three.

[0120] Taking the door opening 16.5° as an example, it can be known from step S2 that the coordinates of the center of gravity (1071.307, -813.955, 439.784) after rotating 16.5° around the hinge axis are (1077.198, -963.232, 444.894), which is the center of gravity position after the door is opened 16.5°. When the front of the car tilts downward at a slope of 20% (the corresponding inclination angle of 20% slope is 11.31°), the corresponding gravity end point coordinates are (1077.19 8-360.003·sin11.31°, -963.232, 444.894-360.003·cos11.31°), that is, (1006.595, -963.232, 91.882), the centripetal moment is calculated by the calculation method in step S3 to be 2.879Nm. Assuming that the opening force applied to the external opening handle under this working condition is F, F=25.070N can be obtained according to the moment balance, which meets the hill-staying requirement of a 20% downward slope of the front of the vehicle.

[0121] In step S5, the hill-holding performance when the left / right side is inclined at a slope of 10% is determined;

[0122] When the left side is tilted at a slope of 10%, taking the door opening 16.5° as an example, it can be seen from step S2 that the coordinates of the center of gravity (1071.307, -813.955, 439.784) after rotating 16.5° around the hinge axis are (1077.198, -963.232, 444.894), which is the center of gravity position after the door is opened 16.5°. When the left side of the car body is tilted at a slope of 10% (the corresponding inclination angle of 10% slope is 5.7106°), the corresponding gravity end point coordinates are (1077.198, -963.2 32-360.003·sin5.7106°, 444.894-360.003·cos5.7106°), that is, (1077.198, -999.053, 86.678). The centripetal moment is obtained by the calculation method in step S3 as -11.728Nm (the negative sign represents that the gravity perpendicular to the hinge axis force produces the door opening moment). Assuming that the opening force applied to the external opening handle under this condition is F', according to the moment balance, F'=6.953N can be obtained, which meets the slope requirement of 10% slope on the left side.

[0123] When the right side is tilted at a slope of 10%, at the opening force peak position (corresponding to the door opening position of 16.5°), the centripetal force generates a centripetal torque in the direction of door closing, so the hill-holding performance does not need to be considered.

[0124] The above describes the idea and process of the calculation method in detail, taking the first gear of a certain car model as an example. The calculation of other gears is similar and will not be repeated here.

[0125] From the above calculation method, it can be seen that through the calculation model, when a certain parameter changes, the result can be obtained quickly and the efficiency is greatly improved.

[0126] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A method for quickly calculating the lifting amount and shifting force of a car door, characterized in that: Includes steps: S1. Determine the position of the hinge axis of the door system; S2. Calculate the lifting amount of the door system; S3. Calculate the force component, centripetal force arm and centripetal moment of the door system perpendicular to the hinge axis; S4. Calculate the ground function torque of each gear of the limiter; S5. Evaluate the hill-holding performance of the door system.

2. The method for quickly calculating the lifting amount and shift force of a vehicle door according to claim 1, characterized in that: In step S1, when the inward inclination angle of the hinge axis is θ, the normal vector is the first vector (0, cosθ, -sinθ); when the backward inclination angle of the hinge axis is δ, the normal vector is the second vector (cosδ, 0, -sinδ); when the hinge axis is inclined inward and forward or backward at the same time, the direction vector of the hinge axis is the cross product of the first vector and the second vector; when the set position point and direction vector passed by the hinge axis are determined, the position of the hinge axis is determined.

3. The method for quickly calculating the lifting amount and shift force of a vehicle door according to claim 1, characterized in that: In the step S1, the coordinates of the projection point of the origin of the coordinate system of the whole vehicle on the hinge axis are calculated, the vector a from the set position point to the origin and the hinge axis direction vector b are calculated, the projection of vector a on vector b is recorded as vector c, and the modulus of vector c is the dot product of vector a and vector b.

4. The method for quickly calculating the lifting amount and shift force of a vehicle door according to any one of claims 1 to 3, characterized in that: In step S2, after inputting the coordinate position data of the center of gravity of the door system, coordinate transformation is first used to move the hinge axis to a position passing through the coordinate origin, and the coordinates of the center of gravity of the door system are moved in the same way; then the Rodrigo rotation formula is used to obtain the coordinates of the center of gravity of the door system after it is rotated a certain angle around the hinge axis after it is moved; finally, coordinate transformation is performed again to move the obtained coordinates of the center of gravity of the door system after it is rotated a certain angle back to the original position, that is, the coordinate position of the center of gravity of the door system after it is rotated a certain angle around the hinge axis in the vehicle coordinate system.

5. The method for quickly calculating the lifting amount and shift force of a vehicle door according to any one of claims 1 to 4, characterized in that: The step S3 comprises: S301, setting the center of gravity of the door system after rotation as a first position point, calculating the coordinates of a projection point of the first position point on the hinge axis, that is, obtaining the coordinates of the first projection point; S302, setting the gravity end point of the center of gravity of the door system after rotation as a second position point, calculating the coordinates of the projection point of the second position point on the hinge axis, that is, obtaining the coordinates of the second projection point; S303, calculating the coordinates of the third position point and the component force F of the gravity perpendicular to the hinge axis; S304, calculating an angle α between a line connecting the second projection point and the third position point and a line connecting the second position point and the third position point; S305: Calculate the centripetal arm L and centripetal moment M of the door system 向心 .

6. The method for quickly calculating the lifting amount and shift force of a vehicle door according to claim 5, characterized in that: In the step S303, the coordinate difference between the first projection point and the first position point is calculated, including the coordinate difference Δx in the X direction, the coordinate difference Δy in the Y direction, and the coordinate difference Δz in the Z direction.

7. The method for quickly calculating the lifting amount and shift force of a vehicle door according to claim 6, characterized in that: In step S305, the centripetal force arm L=(Δx 2 +Δy 2 +Δz 2 ) 0.5 ·sinɑ, the centripetal moment M 向心 =F·L.

8. The method for quickly calculating the lifting amount and shift force of a vehicle door according to claim 7, characterized in that: In step S304, cosɑ is obtained according to the vector dot product formula d·e=|d||e|cosɑ, where vector d is the vector from the third position point to the second projection point, and vector e is the vector from the second position point to the third position point; finally, according to the formula sinɑ=(1-cosɑ 2 ) 0.5 , and obtain sinɑ.

9. The method for quickly calculating the lifting amount and shift force of a vehicle door according to any one of claims 1 to 8, characterized in that: In step S4, according to formula M 开启 =M 限位器 +M 铰链 +M 向心 and formula M 关闭 =M 限位器 +M 铰链 -M 向心 , the ground function torque of each gear of the limiter is obtained, that is, when the measured torque and the calculated torque of the limiter are equal, the actual handle operating force value is the theoretical handle operating force value.

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