Commercial vehicle steering gear positioning method and system, terminal and medium

Abstract

The invention relates to the technical field of automobile design, and particularly provides a commercial vehicle steering gear positioning method and system, a terminal and a medium, and the method comprises the steps: building a steering gear positioning parameterized three-dimensional motion model; obtaining initially input steering gear positioning design parameters, and calculating current space positioning coordinates of the steering gear according to a positioning rule based on the design parameters; based on the current space positioning coordinates, checking is conducted through the parameterized three-dimensional motion model, and checking comprises the steps that the telescopic safety of the steering transmission shaft is evaluated to generate a first quantitative index, and motion interference of a steering rod system is evaluated to generate a second quantitative index; according to comparison between a checking result and a preset condition, carrying out iterative adjustment on a target component in the current spatial positioning coordinate and a target parameter in the design parameters, and carrying out checking again until the preset condition is met; and outputting a steering gear positioning scheme meeting a preset condition. The design efficiency and quality are improved.

Description

Technical Field

[0001] This invention relates to the field of automotive design technology, specifically to a method, system, terminal, and medium for positioning a steering gear in a commercial vehicle. Background Technology

[0002] The steering system of commercial vehicles is a core assembly that ensures vehicle handling stability and safety. Among them, the spatial positioning of the steering gear, that is, its installation position in the vehicle coordinate system, is one of the most critical aspects of steering system design. The positioning of the steering gear not only directly affects the smoothness and accuracy of steering force transmission, but also relates to whether the cab can be tilted for maintenance, and whether the steering linkage interferes with the movement of surrounding components when the suspension bounces.

[0003] Currently, the positioning design of steering gears generally adopts an experience-based trial-and-error method. The design process typically involves engineers manually setting an initial position for the steering gear in 3D software based on the overall vehicle layout and prior experience. Then, motion simulations are performed under multiple independent operating conditions, such as cab rollover and suspension bounce, checking the driveshaft travel and clearance one by one. If the verification fails, the engineer identifies the root cause and manually adjusts the Z-coordinate of the steering gear or the U-value of the steering knuckle arm. Afterward, all simulations must be re-performed. This process is repeated until all operating conditions meet the requirements. This traditional method is extremely inefficient, relying on manual operation and judgment. A complete positioning design often takes several days or even longer, making it unsuitable for the rapid iteration needs of vehicle development. Furthermore, the design quality is unstable, and the adjustment process relies on experience-based judgment, making it difficult to guarantee that the optimal or near-optimal solution can be found each time. Summary of the Invention

[0004] To address the aforementioned issues, this invention provides a method, system, terminal, and medium for positioning steering gears in commercial vehicles, thereby improving design efficiency and quality.

[0005] In a first aspect, the technical solution of the present invention provides a method for positioning a steering gear in a commercial vehicle, comprising the following steps: Establish a parameterized three-dimensional motion model of the steering gear positioning, including the cab, steering mechanism, frame, and front axle suspension system; Obtain the initial input steering gear positioning design parameters, and calculate the current spatial positioning coordinates of the steering gear based on the design parameters and the positioning rules. Based on the current spatial positioning coordinates, the parametric three-dimensional motion model is used for verification. The verification includes: evaluating the safety of the extension and retraction of the steering drive shaft to generate a first quantitative index, and evaluating the motion interference of the steering linkage to generate a second quantitative index. Based on the comparison between the verification results and the preset conditions, the target components in the current spatial positioning coordinates and the target parameters in the design parameters are iteratively adjusted and re-verified until the preset conditions are met. Output the steering gear positioning scheme when the preset conditions are met. The scheme includes the final steering gear spatial positioning coordinates corresponding to the current iteration and the associated final design parameters.

[0006] Secondly, the technical solution of the present invention provides a commercial vehicle steering gear positioning system, comprising: The 3D motion model construction module is used to create a parametric 3D motion model of the steering gear positioning, including the cab, steering mechanism, frame, and front axle suspension system. The initial spatial positioning parameter determination module is used to obtain the initial input steering gear positioning design parameters, and calculate the current spatial positioning coordinates of the steering gear according to the positioning rules based on the design parameters. The parameter verification module is used to verify the parameterized three-dimensional motion model based on the current spatial positioning coordinates. The verification includes: evaluating the safety of the extension and retraction of the steering drive shaft to generate a first quantitative index, and evaluating the motion interference of the steering linkage to generate a second quantitative index. The iterative optimization module is used to iteratively adjust the target components in the current spatial positioning coordinates and the target parameters in the design parameters based on the comparison between the verification results and the preset conditions, and trigger a re-verification until the preset conditions are met. The positioning scheme output module is used to output the steering gear positioning scheme when the preset conditions are met. The scheme includes the final steering gear spatial positioning coordinates corresponding to the current iteration and the associated final design parameters.

[0007] Thirdly, the technical solution of the present invention provides a terminal, comprising: Memory used to store steering system positioning programs for commercial vehicles; A processor is configured to implement the steps of the commercial vehicle steering gear positioning method as described above when executing the commercial vehicle steering gear positioning program.

[0008] Fourthly, the present invention provides a computer-readable storage medium storing a commercial vehicle steering gear positioning program, wherein the commercial vehicle steering gear positioning program, when executed by a processor, implements the steps of the commercial vehicle steering gear positioning method as described in any of the above claims.

[0009] As can be seen from the above technical solutions, this application has the following advantages: it establishes a parametric three-dimensional motion model and presets positioning rules, verification conditions and adjustment strategies. Based on the constructed model and conditions, it realizes an iterative process from input design parameters to adjustment, improves design efficiency, and can quickly obtain feasible positioning solutions that meet various working condition constraints, thus shortening the development cycle. It uses quantitative indicators and preset conditions to make objective judgments and automatically finds steering gear positioning coordinates and steering gear design parameters that meet safety constraints through iterative optimization, ensuring the reliability and consistency of the design results, thereby guaranteeing the optimality and stability of design quality. Attached Figure Description

[0010] To more clearly illustrate the technical solution of this application, the accompanying drawings used in the description will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a schematic flowchart of a commercial vehicle steering gear positioning method provided in an embodiment of the present invention.

[0012] Figure 2 This is a schematic block diagram of a commercial vehicle steering gear positioning system provided in an embodiment of the present invention.

[0013] Figure 3 This is a schematic diagram of the structure of a terminal provided in an embodiment of the present invention. Detailed Implementation

[0014] To make the purpose, features, and advantages of this application more apparent and understandable, specific embodiments and accompanying drawings will be used to clearly and completely describe the technical solution protected by this application. Obviously, the embodiments described below are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0015] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this application and in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0016] Figure 1 This is a schematic flowchart of a commercial vehicle steering gear positioning method provided by an embodiment of the present invention. Figure 1The executing entity can be a commercial vehicle steering gear positioning system. The commercial vehicle steering gear positioning method provided in this embodiment of the invention is executed by a computer device, and correspondingly, the commercial vehicle steering gear positioning system runs within the computer device. Depending on different requirements, the order of the steps in this flowchart can be changed, and some steps can be omitted.

[0017] like Figure 1 As shown, the method includes the following steps.

[0018] S1. Establish a parameterized three-dimensional motion model of the steering gear positioning, including the cab, steering mechanism, frame, and front axle suspension system.

[0019] S2: Obtain the initial input steering gear positioning design parameters, and calculate the current spatial positioning coordinates of the steering gear according to the positioning rules based on the design parameters.

[0020] S3. Based on the current spatial positioning coordinates, the parametric three-dimensional motion model is used for verification. The verification includes: evaluating the safety of the extension and retraction of the steering drive shaft to generate a first quantitative index, and evaluating the motion interference of the steering linkage to generate a second quantitative index.

[0021] S4. Based on the comparison between the verification results and the preset conditions, iteratively adjust the target components in the current spatial positioning coordinates and the target parameters in the design parameters, and re-verify until the preset conditions are met.

[0022] S5 outputs the steering gear positioning scheme when the preset conditions are met. The scheme includes the final steering gear spatial positioning coordinates corresponding to the current iteration and the associated final design parameters.

[0023] This embodiment first establishes a parametric three-dimensional motion model, providing a unified analysis environment that can automatically and repeatedly perform simulations of cab rollover and suspension bounce to meet subsequent automated verification. Then, it calculates the current spatial positioning coordinates according to the positioning rules, providing the steering gear positioning starting point, reducing meaningless initial iterations and improving convergence speed.

[0024] Furthermore, as a refinement and extension of the specific implementation of the above embodiments, in order to fully illustrate the specific implementation process of this embodiment, another embodiment of a commercial vehicle steering gear positioning method is provided, which includes the following steps.

[0025] S101, construct a parametric 3D motion model.

[0026] A parametric three-dimensional motion model of the steering gear positioning, including the cab, steering mechanism, frame, and front axle suspension system, is established. The parametric three-dimensional motion model in this embodiment is a dynamic digital system with parameter-driven, kinematic simulation, and automatic verification capabilities.

[0027] The model comprises four major systems that are strongly related to steering gear positioning: the cab assembly, the steering control mechanism (including the steering column, intermediate drive shaft, universal joint, etc.), the frame assembly, and the front axle suspension system (including the axle, leaf springs / air springs, shock absorbers, steering knuckle arms, steering linkage, etc.).

[0028] In 3D design software such as CREO and CATIA, the first step is to establish 3D geometric models of each system based on the overall vehicle layout digital model. Specifically, based on the actual mechanical connections and motion constraints, correct assembly constraints and kinematic pairs are defined between each component. For example, between the cab and the frame, a revolute joint around a specific tilting axis is defined to simulate its maintenance state from a leveled state to its maximum tilting angle; between the front axle and the frame, its vertical motion relationship is defined through suspension characteristics to simulate suspension bounce under various load conditions such as no load, full load, and overload; between the segments of the steering mechanism, universal joints and sliding splines are defined to accurately reflect its extension, contraction, and angle changes during the cab tilting process; between the steering linkage and the steering gear rocker arm and the front axle steering knuckle, ball joints are defined to transmit steering motion.

[0029] This model can be parameterized, meaning a series of key design dimensions affecting steering gear positioning are defined as parameters that can be independently modified and drive global changes in the model. The main parameters include: Cab installation parameters: longitudinal coordinate M and lateral coordinate N of the cab floor mounting holes; Chassis geometry parameters: Chassis web height P; Steering system parameters: height U of the center of the steering knuckle arm ball joint, theoretical length W of the steering column fork; Motion range parameters: maximum cab tilt angle, suspension design travel, etc.

[0030] These parameters are linked to and driven by the model's sketches, reference planes, and feature dimensions. For example, parameter P directly controls the height of the upper flange of the frame longitudinal beam from the reference plane, while parameter U directly controls the stretching height of the steering knuckle arm 3D model.

[0031] In the model, the spatial position of the steering gear body is not fixed, but dynamically associated with the aforementioned parameters through positioning rules. Specifically, the software defines the installation coordinate system for the steering gear component, and establishes an equation relationship between the coordinate values ​​(X, Y, Z) of this coordinate system and the input parameters to realize the mapping from the design parameter input to the steering gear spatial pose output.

[0032] The model incorporates an automated calibration program that performs simulations under preset conditions and extracts key data. On one hand, the program drives the model, causing the cab to move continuously from a level position to its maximum tilt position. The program monitors the changes in the center distance between the forks at both ends of the intermediate driveshaft in real time, automatically recording and outputting the length A1 in the level position and the length B1 in the maximum tilt position. On the other hand, the program drives the model, simulating the entire process of the suspension from its extreme downward jump to its extreme upward jump. The program continuously calculates the minimum spatial distance between components such as the steering tie rods and lateral tie rods and adjacent components such as the frame, tires, and stabilizer bars, automatically filtering and outputting the global minimum instantaneous distance C1 during this process.

[0033] It should be noted that, based on the parametric 3D motion model, a set of scripts or program modules that can automatically execute simulation tasks, collect data, and complete calculations are written and integrated using the secondary development interface and kinematic analysis module provided by the 3D design software. The automated verification program is integrated or associated with the 3D model file as a set of "macro commands," "relations," "user-defined features (UDFs)," or plugins written via API.

[0034] (1) Implementation of automated verification of cab rollover condition The program first automatically identifies the predefined "cab tilting" mechanism in the model. It then controls the "servo motor" or "driver" of this mechanism via API, driving the cab to move continuously from 0° (flat state) to the maximum tilting angle according to preset step size and speed.

[0035] During motion simulation, the program continuously monitors the effective length of the steering driveshaft using pre-defined measurement features. This measurement is defined as the distance between the center points of the universal joint cross shafts at both ends of the driveshaft. The program reads this measurement value in real time via API.

[0036] The program has built-in logic that records the first measured value as the first extension length A1 at the start of the simulation, and continuously compares it throughout the simulation, recording the value when the measured value reaches its maximum as the second extension length B1. After the simulation ends, the program automatically stores these two key values, A1 and B1, into a specified parameter or external file.

[0037] (2) Implementation of automated verification of suspension bounce condition The system automatically applies a drive to the suspension mechanism that simulates the vertical hop of the wheels, which simulates a complete cycle from the extreme down-hop position to the extreme up-hop position.

[0038] At each simulation step of the suspension bounce, the program automatically calculates the "enveloping body" swept out by the steering linkage during the movement. The steering linkage can be a tie rod. The program automatically performs a clearance analysis on this envelope body and a preset set of inspection objects, including specific areas of the chassis, tire envelopes, stabilizer bars, etc. The program iterates through all clearance analysis results at all time points throughout the entire bounce cycle, automatically finds and records the smallest clearance value, and uses it as the second quantification index C1, i.e., the minimum instantaneous distance. If this value is negative, it indicates that solid-penetration interference has occurred.

[0039] (3) Calculation and output of quantitative indicators After completing the two simulations mentioned above and acquiring the raw data A1, B1, C1, and W, the program automatically calculates the first quantization index Q1 according to a preset formula. The second quantization index Q2 is directly equal to C1. Subsequently, the program compares Q1 and Q2 with preset safety thresholds and provides feedback to the user in the form of a dialog box, report file, or model parameter update.

[0040] The automated verification program is the executor of the entire iterative optimization process. When the upstream step provides new design parameters, the program drives the model to update the geometry, then automatically starts the simulation process described above, and finally outputs a new set of Q1 and Q2 values.

[0041] S102, Initialize spatial positioning coordinates.

[0042] This step provides an initial starting point, specifically obtaining the initial input steering gear positioning design parameters, and calculating the current spatial positioning coordinates of the steering gear based on the design parameters and the positioning rules.

[0043] The design parameters include: longitudinal and lateral parameters related to the cab mounting position, vertical parameters related to the frame height, and steering knuckle arm height parameters related to the steering transmission mechanism. In one specific embodiment, the design parameters are the longitudinal position M and lateral position N of the cab floor hole, the frame web height P, and the steering knuckle arm height U.

[0044] The longitudinal parameter M represents the fore-and-aft position of the hole in the cab floor. This parameter determines the reference point for the upper end of the steering column in the vehicle's X-direction, which is the fore-and-aft direction. The steering gear must be aligned with this reference point in the X-direction to ensure that the angle and length of the steering drive shaft are within a reasonable range.

[0045] The lateral parameter N represents the left and right positions of the holes in the cab floor, and this parameter determines the center plane of the steering system. The steering gear is arranged symmetrically or offset around this center in the Y direction to ensure symmetrical transmission of steering forces.

[0046] The vertical parameter P, related to the chassis web height, determines the steering gear mounting height. The chassis is the main load-bearing and mounting base for the steering gear, and its height determines the possible range of the steering gear in the vertical space of the entire vehicle.

[0047] The steering knuckle arm height parameter U is not directly used to calculate the initial coordinates, but it is included in the design parameter set. The steering knuckle arm is a key component that is directly connected to the output end of the steering gear, and its height is the main variable for subsequent evaluation and optimization of motion interference.

[0048] By selecting these four parameters, the problem of steering gear positioning is simplified from a blind search in three-dimensional space to parameterized determination in these four dimensions.

[0049] Based on the design parameters, the current spatial positioning coordinates of the steering gear are calculated according to the positioning rules. Specifically, the longitudinal component of the spatial positioning coordinates is the value of the longitudinal parameter, the lateral component is the value of the lateral parameter, and the vertical component is the product of the value of the vertical parameter and a preset proportional coefficient. The origin of the coordinates is set at the position of the front suspension hanger.

[0050] Specifically, the longitudinal position M is used as the X-coordinate value of the current spatial positioning coordinates, the lateral position N is used as the Y-coordinate value, and half of the frame height P is used as the Z-coordinate value, with the origin of the coordinates set at the front suspension hanger position. That is, the positioning rule is X=M, Y=N, Z=k*P.

[0051] The horizontal plane positioning is based on the principles of "shortest path" and "minimum torque," i.e., X=M, Y=N. Ideally, the steering driveshaft should be as short and straight as possible to improve rigidity and reduce vibration and wear. Aligning the horizontal projection position (X,Y) of the steering gear directly with the cab input point (M,N) satisfies the ideal condition and provides an initial low-stress, high-efficiency geometry for the driveshaft system.

[0052] Vertical positioning is based on considerations of "torque balance" and "spatial centering," i.e., Z = P / 2. Regarding torque balance, the steering gear pushes the steering knuckle arm via the rocker arm and tie rod. Assuming the center height of the steering knuckle arm ball joint is approximately near the axle center height, the steering gear rocker arm shaft needs to perform an arc motion near this height. Setting the steering gear mounting height Z to half the frame web height P typically allows the rocker arm shaft centerline to be close to or slightly higher than the axle centerline in practice, providing an initial, approximately horizontal, ideal mounting posture for the steering linkage, which helps ensure the symmetry and smoothness of the left and right steering torques. Regarding spatial centering, the frame web height P defines the available vertical space from the suspension hanger (coordinate origin) to the upper wing surface of the frame. Placing the steering gear in the middle of this space, i.e., at position P / 2, provides roughly equal space margins for adjustments in both the up and down directions: adjusting upwards can improve the drive shaft travel when the cab rolls over, while adjusting downwards can optimize the motion clearance when the suspension bounces, so that the initial solution is at an equilibrium point. No matter which aspect of the problem is found in subsequent verification, it can be corrected with a small adjustment amount, thus improving the speed of iterative convergence.

[0053] The origin of the coordinate system is uniformly set at the front suspension hanger position because this point is the physical connection point between the front axle and the vehicle frame, and serves as the kinematic reference for suspension movement. All kinematic analyses are based on this point. Using this point as the origin ensures that all coordinate values ​​have physical meaning directly related to the kinematic analysis, improving the reliability of the positioning.

[0054] S103, based on the current spatial positioning coordinates, uses a parametric 3D motion model for verification.

[0055] The verification includes: evaluating the safety of the extension and retraction of the steering drive shaft to generate a first quantitative index, and evaluating the motion interference of the steering linkage to generate a second quantitative index, specifically including the following steps S103.1 and S103.2.

[0056] S103.1, based on the current spatial positioning coordinates, drive the parametric three-dimensional motion model to simulate the process of the cab changing from a level state to a rollover maintenance state, obtain the extension and retraction data of the steering drive shaft, and generate the first quantitative index on the extension and retraction safety of the steering drive shaft based on the data.

[0057] Specifically, based on the first extension length A1 of the steering drive shaft in the leveled state, the second extension length B1 in the overturned maintenance state, and the steering column fork length W, the first quantitative index Q1 is calculated, where Q1=k1*A1+k2*B1+k3*W, and k1,k2,k3 are coefficients determined according to the vehicle platform.

[0058] During the cab tilting process, the intermediate drive shaft connecting the steering gear and the steering wheel (usually a structure with telescopic splines and universal joints) will be stretched or compressed. The safety design objective is that during the entire process from the flat state to the tilting state, the actual telescopic amount of the drive shaft must always be less than its maximum allowable telescopic amount, and there should be sufficient safety margin to prevent it from being pulled off, jammed, or generating excessive additional stress.

[0059] Through the automated simulation of the parametric model, the lengths of the drive shaft in two extreme states can be directly obtained: the length of the drive shaft during normal vehicle driving, that is, the flat state length A1, and the length of the drive shaft when the cab is tilted to the maximum maintenance angle, that is, the maximum tilting state length B1. Then the telescopic change amount of the drive shaft is |B1 - A1|.

[0060] Just knowing the change amount is not enough to judge the safety margin. It must be compared with the available stroke of the drive shaft system. Define the available stroke: Assume that when the drive shaft is in an ideal neutral position (neither stretched nor compressed), the theoretical overlapping length of its spline sleeve and the shaft is the design value, corresponding to a neutral length L_neutral. Its maximum allowable stretching length is L_max, and the maximum allowable compression length is L_min. Then the total available stroke is S_available=(L_max - L_neutral)+(L_neutral - L_min). In practice, L_neutral is very difficult to measure directly, but it is strongly related to the nominal assembly length W of the steering column joint.

[0061] To construct a safety margin index that does not depend on the absolute neutral length and is expressed only by the measurable parameters A1, B1, and W, the following derivation is carried out: Considering the most unfavorable situation, assume that in the flat state (A1), the drive shaft is in a compressed state, and in the tilting state (B1), it is in a stretched state. Then the used compression stroke is Δ_comp = L_neutral - A1 (assuming A1 < L_neutral), and the used stretching stroke is Δ_stretch = B1 - L_neutral (assuming B1 > L_neutral). To ensure safety, the remaining total stroke margin needs to be greater than zero, that is, [(L_max - L_neutral)-Δ_stretch]+[(L_neutral - L_min)-Δ_comp]>0. After arrangement: The remaining total stroke margin R_total=(L_max - L_min)-(B1 - A1)>0.

[0062] However, the total physical travel of the driveshaft (L_max - L_min) is a variable that depends on the specific component model, design tolerances, and wear condition. It cannot be accurately known in the early design stages, and this value varies for different vehicle models and components from different suppliers. Therefore, the design does not rely on the unknown absolute value (L_max - L_min), but can determine the safety indicators using only the measurable values ​​A1 and B1 and the known design value W.

[0063] Considering that the travel of the drive shaft is related to its offset relative to the ideal neutral length L_neutral, we define: δ_A = A1 - L_neutral (offset relative to the neutral position when leveling, which can be positive or negative), δ_B = B1 - L_neutral (offset relative to the neutral position when flipping, which can be positive or negative). Therefore, the absolute value of the travel change is |δ_B - δ_A| = |B1 - A1|.

[0064] The available travel margin R of the driveshaft is related to the positions of δ_A and δ_B within the interval [L_min, L_max]. Therefore, a function f(δ_A, δ_B, W) is needed, consisting of δ_A, δ_B, and a known reference W, such that the value of f is strongly correlated with the true margin R, and that R is inevitably insufficient when f is below a certain threshold T. Based on the geometry of the steering system, a linearization assumption is constructed: within a reasonable arrangement range, the travel margin problem mainly manifests as the risk of excessive stretching of the driveshaft at the end of the rollover. The difference between A1 (leveling length) and L_neutral, δ_A, and the difference between B1 and A1, jointly affect the stretching risk. Therefore, Q1 = k1*A1 + k2*B1 + k3*W is constructed, where k1, k2, and k3 are undetermined coefficients, and Q1 reflects the buffer space. If A1 is small (the driveshaft is in a compressed state when leveling), it reserves more space for stretching during rollover, and Q1 should be increased. If B1 is large (stretched out during overturning), the buffer space is small, and Q1 should be reduced. W is used as a reference length for normalization to eliminate the influence of different steering column designs.

[0065] The general construction principle of the first quantitative indicator Q1 is as follows: it is a linear combination function of the steering driveshaft's leveling length A1, overturning length B1, and column fork reference length W. The value of this function is monotonically related to the actual travel safety margin of the driveshaft system, and when the value of this function is lower than a certain threshold obtained through historical data calibration, it indicates insufficient safety margin. k1, k2, and k3 are coefficients determined according to the vehicle platform.

[0066] Collect a sample library containing N known design cases covering the typical design range of the target vehicle platform (such as heavy-duty trucks, medium-sized buses, etc.). For each case i, obtain a set of basic data: A1_i, B1_i, W_i through its 3D model or physical measurement. For each case i, determine its true safety state through physical bench / road testing, including calculating or measuring its true remaining total travel margin R_true_i, i.e., (L_max-L_min)-|B1_i-A1_i|.

[0067] Using multiple linear regression, establish the mapping relationship between Q1 and the actual safety state, solve the following optimization problem, and find the coefficients k1, k2, k3 such that the predicted value Q1_i is as close as possible to the true value R_true_i:

[0068] The optimization problem described above is a least squares problem, which can be solved directly using mathematical software to obtain k1, k2, and k3 that minimize the overall error.

[0069] In a specific implementation, the output regression equation is: R_true≈2.02*A1-1.01*B1-2.05*W+5.3. To make the Q1 formula simpler and directly comparable to R_true, the constant term is incorporated into the threshold consideration, and the coefficients are rounded down. The final formula used for this vehicle platform is: Q1=2*A1-1*B1-2*W.

[0070] Determining the safety threshold T1: Observe the Q1 values ​​calculated from all safe samples, take the minimum value, and then reserve a certain margin based on engineering experience. For example, if the minimum safe sample has Q1=38, set the safety threshold T1 to 40mm. That is, when Q1≥40mm, it is considered safe.

[0071] S103.2, Based on the current spatial positioning coordinates, drive the parameterized three-dimensional motion model to simulate the jumping process of the suspension system under load, obtain the motion relationship data between the steering linkage and surrounding components, and generate a second quantitative index about the motion interference of the steering linkage based on the data.

[0072] Specifically, the minimum instantaneous distance between the steering linkage and surrounding components during the simulated suspension bounce is obtained, and this minimum instantaneous distance is used as the second quantitative indicator Q2.

[0073] During suspension travel, the movement trajectories of components such as the steering tie rods and drag links may spatially interfere with the vehicle frame, tires, stabilizer bars, engine oil pan, etc. The design safety objective is that, throughout the entire travel, the minimum instantaneous distance between the steering linkage and any surrounding components must be greater than zero, while maintaining a certain dynamic safety clearance.

[0074] The most direct and reliable way to determine motion interference is to calculate and monitor the minimum instantaneous distance, i.e., the second quantitative index Q2 = minimum instantaneous distance. Through automated motion simulation and global clearance scanning of the parametric model, the closest distance value between the steering linkage and all preset inspection objects can be found throughout the entire suspension bounce cycle.

[0075] Determining the safety threshold T2: The static clearance needs to compensate for the elastic deformation of components under dynamic loads, the displacement of bushings and ball joints, dimensional changes caused by thermal expansion, and control and measurement errors. For example, a safety threshold T2 of 2mm can be set. If Q2 < 2mm, it is highly likely to lead to contact, friction, or even collision in actual dynamic operating conditions, requiring design modifications. Q2 ≥ 2mm provides a basic guarantee for safe dynamic operation.

[0076] S104, iterative adjustments are made based on the verification results.

[0077] Based on the comparison between the verification results and preset conditions, the target components in the current spatial positioning coordinates and the target parameters in the design parameters are iteratively adjusted. Specifically, this includes: comparing the first quantitative indicator with the preset first safety condition, and comparing the second quantitative indicator with the preset second safety condition; if the first quantitative indicator does not meet the first safety condition, but the second quantitative indicator meets the second safety condition, then the target parameters in the target components of the current spatial positioning coordinates related to the vertical positioning of the steering gear are adjusted according to the first adjustment strategy; if the second quantitative indicator does not meet the second safety condition, but the first quantitative indicator meets the first safety condition, then the design parameters related to the steering knuckle arm height are adjusted according to the second adjustment strategy; if neither the first nor the second quantitative indicator meets the corresponding safety condition, then the target parameters in the target components of the current spatial positioning coordinates related to the vertical positioning of the steering gear are adjusted according to the first adjustment strategy.

[0078] The first security condition is configured as follows: the first quantitative indicator must be greater than or equal to the preset first security threshold; the second security condition is configured as follows: the second quantitative indicator must be less than the second security threshold.

[0079] Specifically, the iterative adjustment decision is based on decision tree logic, which takes the first quantitative indicator Q1 and the second quantitative indicator Q2 as inputs, uses two preset safety thresholds T1 and T2 as judgment criteria, and outputs specific parameter adjustment instructions.

[0080] If both Q1≥T1 and Q2≤T2 are true, then the current design scheme is determined to satisfy both the transmission shaft stroke safety and linkage motion interference safety requirements, the iteration terminates, and the final scheme is output.

[0081] If the above AND condition is not met, then proceed to one of the following three adjustment branches: a) Only insufficient stroke: If Q1 < T1 and Q2 ≤ T2. This situation indicates that the buffer margin of the drive shaft is insufficient when the cab flips, but the movement clearance of the current steering rod system is safe. The root cause of the problem is diagnosed as that the vertical installation position (Z coordinate) of the steering gear may be too high, resulting in excessive stretching of the drive shaft during flipping; b) Only interference risk exists: If Q1 ≥ T1 and Q2 > T2. This situation indicates that the steering rod system will interfere with surrounding components or the clearance is too small during suspension jounce, but the drive shaft stroke is safe. The root cause of the problem is diagnosed as that the ball head center height (U value) of the steering knuckle arm may be too high, resulting in an upward shift of the movement envelope of the drag link and being too close to components such as the frame; c) Neither is satisfied: If Q1 < T1 and Q2 > T2. It indicates that the current design has both insufficient stroke and movement interference risks.

[0082] Adjust the target parameter in the target component of the current spatial positioning coordinates related to the vertical positioning of the steering gear according to the first adjustment strategy, specifically including: according to the difference between the first quantization index and the first safety threshold, proportionally reduce the vertical component in the current spatial positioning coordinates.

[0083] Adjust the target parameter in the target component of the current spatial positioning coordinates related to the height of the steering knuckle arm according to the second adjustment strategy, specifically including: according to the difference between the second quantization index and the second safety threshold, proportionally reduce the height parameter of the steering knuckle arm.

[0084] For the problem of insufficient stroke, set the first adjustment strategy. The adjustment object of this strategy is the vertical component in the spatial positioning coordinates of the steering gear, that is, the Z coordinate. Lowering the installation height of the steering gear will lower the output end of the steering gear. The drag link connecting the steering gear and the steering knuckle arm will tend to be more horizontal or slightly inclined downward. And due to the geometric relationship between the drag link and the steering knuckle arm, the instantaneous movement trajectory of the ball head center of the steering knuckle arm will change slightly. At the same time, the lowering of the steering gear position will change its relative position relationship with the cab floor hole. During the cab flipping process, this will reduce the stretching amount of the drive shaft at the end of flipping (B1 decreases), and at the same time, the influence on the length (A1) when landing is relatively small. According to the formula Q1 = 2A1 - B1 - 2W, the decrease of B1 will directly lead to an increase in the value of Q1, thus effectively improving the stroke margin.

[0085] [[ID=·17]]According to historical data regression, there is an approximately linear relationship between the stroke margin deviation (T1 - Q1) and the change amount ΔZ of the Z coordinate that needs to be adjusted. In a specific embodiment, ΔZ = (T1 - Q1) * g is adopted, where g is an empirical coefficient, indicating that for every approximately g millimeters the steering gear is lowered, the stroke margin index Q1 can be increased by about 1 millimeter. For example, g = 1.8.

[0086] To address the motion interference issue, a second adjustment strategy is implemented, targeting the steering knuckle arm height U in the design parameters. Lowering the height of the steering knuckle arm ball joint center is the most direct and effective method to resolve motion interference. The steering knuckle arm ball joint is one of the fixed endpoints of the steering linkage; lowering this point reduces the overall spatial position of the steering linkage, increasing the static clearance between the linkage and the upper frame, engine, and other components. Consequently, during suspension movement, its minimum instantaneous distance Q2 will significantly increase.

[0087] The degree of interference risk is quantified by (Q2-T2). The adjustment amount ΔU is proportional to this deviation. In a specific embodiment, ΔU = (Q2-T2)*m is used, where m is a proportionality coefficient. For example, m = 50 means that for every 0.1 mm deviation of the minimum instantaneous distance, the steering knuckle arm height needs to be reduced by 5 mm to effectively eliminate the interference risk.

[0088] When both Q1 and Q2 exceed the limits, the first adjustment strategy should be prioritized. Lowering the steering gear makes the tie rod more horizontal, which can sometimes simultaneously reduce the movement trajectory of the linkage, thus alleviating some interference. Conversely, if U (the second strategy) is prioritized, while it may improve Q2, it usually does not help improve Q1. That is, adjusting the Z-coordinate may improve Q1 while also potentially having a positive impact on Q2; therefore, the first adjustment strategy should be prioritized.

[0089] S105 outputs the steering gear positioning scheme when preset conditions are met.

[0090] The output scheme includes the final steering gear spatial positioning coordinates corresponding to the current iteration and the associated final design parameters.

[0091] In the final steering gear spatial positioning coordinates (X_final, Y_final, Z_final), X_final and Y_final are consistent with the initial input parameters M (longitudinal) and N (lateral), and Z_final is the vertical installation height of the steering gear after iterative optimization.

[0092] The final steering gear spatial positioning coordinates (X_final, Y_final, Z_final) are generated based on the chassis web height P_final and the steering knuckle arm height U_final. This embodiment uses a model that directly adjusts Z, so P_final is the same as the initial input P. The steering knuckle arm height U_final is the value optimized by the second adjustment strategy.

[0093] The above text provides a detailed description of an embodiment of a commercial vehicle steering gear positioning method. Based on the commercial vehicle steering gear positioning method described in the above embodiment, this invention also provides a commercial vehicle steering gear positioning system corresponding to the method.

[0094] Figure 2 This is a schematic block diagram of a commercial vehicle steering gear positioning system provided in an embodiment of the present invention. In this embodiment, the commercial vehicle steering gear positioning system 200 can be divided into multiple functional modules according to the functions it performs. A module, as referred to in this invention, is a series of computer program segments that can be executed by at least one processor and perform a fixed function, and is stored in memory.

[0095] The 3D motion model construction module 210 is used to establish a parametric 3D motion model of the steering gear positioning, including the cab, steering mechanism, frame, and front axle suspension system.

[0096] The initial spatial positioning parameter determination module 220 is used to obtain the initial input steering gear positioning design parameters and calculate the current spatial positioning coordinates of the steering gear according to the positioning rules based on the design parameters.

[0097] The parameter verification module 230 is used to perform verification based on the current spatial positioning coordinates using the parameterized three-dimensional motion model. The verification includes: evaluating the safety of the extension and retraction of the steering drive shaft to generate a first quantitative index, and evaluating the motion interference of the steering linkage to generate a second quantitative index.

[0098] The iterative optimization module 240 is used to iteratively adjust the target components in the current spatial positioning coordinates and the target parameters in the design parameters based on the comparison between the verification results and the preset conditions, and trigger a re-verification until the preset conditions are met.

[0099] The positioning scheme output module 250 is used to output the steering gear positioning scheme when the preset conditions are met. The scheme includes the final steering gear spatial positioning coordinates corresponding to the current iteration and the associated final design parameters.

[0100] The commercial vehicle steering gear positioning system of this embodiment is used to implement the aforementioned commercial vehicle steering gear positioning method. Therefore, the specific implementation of this system can be found in the embodiment section of the commercial vehicle steering gear positioning method above. Thus, the specific implementation can be referred to the description of the corresponding embodiments, and will not be elaborated here.

[0101] Furthermore, since the commercial vehicle steering gear positioning system of this embodiment is used to implement the aforementioned commercial vehicle steering gear positioning method, its function corresponds to the function of the above method, and will not be repeated here.

[0102] Figure 3 This is a schematic diagram of a terminal 300 provided in an embodiment of the present invention, including: a processor 310, a memory 320, and a communication unit 330. The processor 310 is used to implement the process steps of the above-described commercial vehicle steering gear positioning method embodiment when implementing the commercial vehicle steering gear positioning program stored in the memory 320.

[0103] This invention also provides a computer storage medium, which may be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc. The computer storage medium stores a commercial vehicle steering gear positioning program, which, when executed by a processor, implements the process steps of the above-described commercial vehicle steering gear positioning method embodiment.

[0104] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for positioning a steering gear in a commercial vehicle, characterized in that, Includes the following steps: Establish a parameterized three-dimensional motion model of the steering gear positioning, including the cab, steering mechanism, frame, and front axle suspension system; Obtain the initial input steering gear positioning design parameters, and calculate the current spatial positioning coordinates of the steering gear based on the design parameters and the positioning rules. Based on the current spatial positioning coordinates, the parametric three-dimensional motion model is used for verification. The verification includes: evaluating the safety of the extension and retraction of the steering drive shaft to generate a first quantitative index, and evaluating the motion interference of the steering linkage to generate a second quantitative index. Based on the comparison between the verification results and the preset conditions, the target components in the current spatial positioning coordinates and the target parameters in the design parameters are iteratively adjusted and re-verified until the preset conditions are met. Output the steering gear positioning scheme when the preset conditions are met. The scheme includes the final steering gear spatial positioning coordinates corresponding to the current iteration and the associated final design parameters.

2. The commercial vehicle steering gear positioning method according to claim 1, characterized in that, The design parameters include: longitudinal and lateral parameters related to the cab mounting position, vertical parameters related to the chassis height, and steering knuckle arm height parameters related to the steering transmission mechanism.

3. The commercial vehicle steering gear positioning method according to claim 2, characterized in that, Based on the design parameters, the current spatial positioning coordinates of the steering gear are calculated according to the positioning rules. Specifically, the longitudinal component of the spatial positioning coordinates is the value of the longitudinal parameter, the lateral component is the value of the lateral parameter, and the vertical component is the product of the value of the vertical parameter and a preset proportional coefficient. The origin of the coordinates is set at the position of the front suspension hanger.

4. The commercial vehicle steering gear positioning method according to any one of claims 1 to 3, characterized in that, Based on the current spatial positioning coordinates, the parametric 3D motion model is used for verification, specifically including: Based on the current spatial positioning coordinates, the parametric three-dimensional motion model is driven to simulate the process of the cab changing from a level state to a tilted maintenance state, and the extension and retraction data of the steering drive shaft is obtained. Based on this data, the first quantitative index on the extension and retraction safety of the steering drive shaft is generated. Based on the current spatial positioning coordinates, the parametric three-dimensional motion model is driven to simulate the jumping process of the suspension system under load, obtain the motion relationship data between the steering linkage and surrounding components, and generate a second quantitative index about the motion interference of the steering linkage based on the data.

5. The commercial vehicle steering gear positioning method according to claim 4, characterized in that, Based on this data, a first quantitative indicator for the safety of steering driveshaft extension and retraction was generated, specifically including: Based on the first extension length A1 of the steering drive shaft in the leveled state, the second extension length B1 in the overturned maintenance state, and the steering column fork length W, the first quantitative index Q1 is calculated, where Q1=k1*A1+k2*B1+k3*W, and k1,k2,k3 are coefficients determined according to the vehicle platform. Based on this data, a second quantitative index regarding the motion interference of the steering linkage is generated, specifically including: The minimum instantaneous distance between the steering linkage and surrounding components during the simulated suspension bounce is obtained, and this minimum instantaneous distance is used as the second quantitative indicator Q2.

6. The commercial vehicle steering gear positioning method according to claim 4, characterized in that, Based on the comparison between the verification results and the preset conditions, the target components in the current spatial positioning coordinates and the target parameters in the design parameters are iteratively adjusted, specifically including: The first quantitative indicator is compared with the preset first security condition, and the second quantitative indicator is compared with the preset second security condition. If the first quantitative indicator does not meet the first safety condition, and the second quantitative indicator meets the second safety condition, then the target parameters in the target components of the current spatial positioning coordinates related to the vertical positioning of the steering gear are adjusted according to the first adjustment strategy. If the second quantitative indicator does not meet the second safety condition, while the first quantitative indicator meets the first safety condition, then the design parameters related to the steering knuckle arm height are adjusted according to the second adjustment strategy. If neither the first quantitative indicator nor the second quantitative indicator meets the corresponding safety conditions, the target parameters in the target components of the current spatial positioning coordinates related to the vertical positioning of the steering gear will be adjusted according to the first adjustment strategy. The first security condition is configured as follows: the first quantitative indicator must be greater than or equal to the preset first security threshold; the second security condition is configured as follows: the second quantitative indicator must be less than the second security threshold.

7. The commercial vehicle steering gear positioning method according to claim 6, characterized in that, The target parameters in the target components of the current spatial positioning coordinates related to the vertical positioning of the steering gear are adjusted according to the first adjustment strategy, specifically including: Based on the difference between the first quantitative index and the first safety threshold, the vertical component in the current spatial positioning coordinates is reduced proportionally. The target parameters in the target components of the current spatial positioning coordinates related to the steering knuckle arm height are adjusted according to the second adjustment strategy, specifically including: Based on the difference between the second quantitative indicator and the second safety threshold, the steering knuckle arm height parameter is reduced proportionally.

8. A commercial vehicle steering gear positioning system, characterized in that, include: The 3D motion model construction module is used to create a parametric 3D motion model of the steering gear positioning, including the cab, steering mechanism, frame, and front axle suspension system. The initial spatial positioning parameter determination module is used to obtain the initial input steering gear positioning design parameters, and calculate the current spatial positioning coordinates of the steering gear according to the positioning rules based on the design parameters. The parameter verification module is used to verify the parameterized three-dimensional motion model based on the current spatial positioning coordinates. The verification includes: evaluating the safety of the extension and retraction of the steering drive shaft to generate a first quantitative index, and evaluating the motion interference of the steering linkage to generate a second quantitative index. The iterative optimization module is used to iteratively adjust the target components in the current spatial positioning coordinates and the target parameters in the design parameters based on the comparison between the verification results and the preset conditions, and trigger a re-verification until the preset conditions are met. The positioning scheme output module is used to output the steering gear positioning scheme when the preset conditions are met. The scheme includes the final steering gear spatial positioning coordinates corresponding to the current iteration and the associated final design parameters.

9. A terminal, characterized in that, include: Memory used to store steering system positioning programs for commercial vehicles; A processor, configured to implement the steps of the commercial vehicle steering gear positioning method as described in any one of claims 1 to 7 when executing the commercial vehicle steering gear positioning program.

10. A computer-readable storage medium, characterized in that, The readable storage medium stores a commercial vehicle steering gear positioning program, which, when executed by a processor, implements the steps of the commercial vehicle steering gear positioning method as described in any one of claims 1 to 7.

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