Method for optimizing torque fluctuation of a triple cardan joint

Abstract

This invention discloses a method for optimizing torque fluctuation in a three-way universal joint, relating to the field of automotive engineering technology. The method includes the following steps: defining parameters for the transmission relationship of the three-way universal joint; establishing the spatial geometric relationships between the angles between the input shaft and intermediate shaft I, intermediate shaft I and intermediate shaft II, intermediate shaft II and the output shaft, as well as the corresponding phase angles and plane angles; and determining the initial value range of each parameter. This invention, through the three-way universal joint and parameter optimization method, improves the spatial layout flexibility of the steering device, reduces the dependence on axis angle matching, and makes the steering wheel position and column tilt angle more ergonomic; simultaneously, it effectively controls torque fluctuation, reduces limitations of surrounding systems, and improves steering smoothness and overall vehicle handling performance.

Description

Technical Field

[0001] This invention relates to the field of automotive engineering technology, and specifically to a method for optimizing torque fluctuation in a three-way universal joint. Background Technology

[0002] With the rapid development of the automotive industry and the increasing demands of users for vehicle handling stability and driving comfort, the steering system, as a core component of the vehicle chassis, directly affects the vehicle's handling and driving safety. In the steering system, the steering intermediate shaft plays a crucial role in connecting the steering column and the steering gear, transmitting the driver's input torque and steering angle. Due to limited space in the vehicle layout and interference between various components, the steering column and the steering gear input shaft are often arranged in a non-coplanar, non-collinear spatial configuration. Therefore, a universal joint is typically used to achieve variable-angle torque transmission. However, under non-ideal layout conditions, universal joint transmission cannot achieve completely constant velocity, resulting in periodic fluctuations in the output torque relative to the input torque during steering—a phenomenon known as torque ripple—which affects steering feel and overall vehicle NVH performance.

[0003] In existing technologies, a double cross-shaft universal joint structure is commonly used. By satisfying the conditions of equal angles between the input shaft and the intermediate shaft, and matching the phase angle with the plane angle, torque fluctuations can be reduced to some extent. However, this structure has high requirements for spatial arrangement, and it is often difficult to achieve the optimal layout in actual engineering. To adapt to complex spatial conditions, existing solutions use a triple cross-shaft universal joint structure, extending the transmission system to a four-segment structure to improve layout flexibility. However, although this type of solution improves spatial adaptability, the addition of a universal joint significantly increases the number of system parameters (such as multiple angles and phase angles). The lack of systematic theoretical modeling and optimization methods makes it difficult to effectively assess and control torque fluctuations, resulting in a design process that relies on experience, low optimization efficiency, and difficulty in achieving optimal control of torque fluctuations while meeting complex layout conditions.

[0004] The information disclosed in the background section is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a method for optimizing torque fluctuation in a three-way universal joint, in order to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for optimizing torque fluctuation in a three-way universal joint, comprising the following steps: Define the parameters of the three-way universal joint transmission relationship and establish the included angle between the input shaft and intermediate shaft I. The included angle between intermediate axis I and intermediate axis II The angle between intermediate shaft II and output shaft and the corresponding phase angle , and plane angle , Determine the spatial geometric relationship between them and determine the initial range of values ​​for each parameter; Based on spatial geometric relationships, an equivalent analysis model of the three-way universal joint transmission is constructed, transforming the three-way universal joint transmission into one with an equivalent included angle. The single universal joint drive form with initial phase is used to characterize the motion relationship between the input shaft and the output shaft; Based on the equivalent analysis model, combined with , , , , and , The functional relationship between them is used to calculate the equivalent angle. And establish the equivalent included angle The correspondence between the parameters; Obtaining the equivalent included angle Based on the torque fluctuation and the equivalent angle The calculation relationship between them is used to calculate and quantify the torque fluctuation during the transmission process of the three-way universal joint; Based on the calculation results of torque fluctuation, for , , and , Adjustments are made, and the equivalent angle is continuously called during the adjustment process. Iterative analysis of the torque fluctuation calculation results is performed to reduce the equivalent angle. And reduce torque fluctuations.

[0007] Preferably, starting from the completeness of the equivalent angle calculation expression, the coupling relationship of multiple parameters is limited, and the correlation expression between angle combination terms is strengthened. The steps are as follows: right , , Perform a unified angle system conversion and execute squaring operations separately, while constructing an initial data set containing each angle variable; right and Perform difference calculation to generate the first angle difference variable, and input the variable into the cosine and sine function calculation module to obtain the corresponding trigonometric function value sequence; Will and The values ​​are superimposed on the first angle difference variable to generate the second angle difference variable, and then the cosine and sine functions are applied to this variable respectively to form an extended trigonometric function value set. Perform a weighted combination operation on all trigonometric function values, and then perform fourth root processing on the combination result to output the equivalent included angle. The calculation results.

[0008] Preferably, the calculation path revolves around torque fluctuation, constraining the functional relationship between the equivalent angle and the fluctuation amount, and clarifying the calculation expression logic. The steps are as follows: Input equivalent angle Convert to radian representation and construct a single-variable input data structure; right Perform sine function calculation, generate the first intermediate calculated value, and record the corresponding angle position; For the same Perform tangent function calculation to generate a second intermediate calculated value and establish a correspondence between it and the first intermediate calculated value; By multiplying the two intermediate calculated values ​​and amplifying the result using a scaling factor, a numerical expression of torque fluctuation is obtained.

[0009] Preferably, the parameter adjustment strategy is refined by combining the characteristics of multivariate coordinated change, highlighting the linkage relationship between parameters from different perspectives. The steps are as follows: right , , Set the value range and discretize each range according to the preset step size to generate an angle parameter grid set; right and The interval is divided, and multiple phase combination sequences are generated at fixed intervals; the angle parameter grid set and the phase combination sequence are combined by Cartesian product to form a complete parameter combination matrix; Input each parameter combination into the equivalent angle calculation expression one by one to obtain the corresponding... The results are collected and stored.

[0010] Preferably, the equivalent included angles in the parameter combination matrix are... The result set is filtered and sorted according to a preset sorting rule. Arrange the values, extract the subset of parameter combinations that satisfy the minimization trend, and assign the corresponding values ​​of this parameter combination subset to the appropriate values. , , , and Perform association mapping to form a set of constraints for subsequent parameter adjustments.

[0011] Preferably, to ensure consistency in the expression of spatial geometric relationships, supplementary explanations are provided for the angle parameter system, strengthening the logical connections between various angles. The steps are as follows: right , , Perform unified variable numbering and establish an angle index mapping table; Will and Each angle is associated with its corresponding angle index to construct a set of correspondences between plane angles and the angle between the axes; right and Number and classify them, and establish the matching relationship between phase angle and corresponding axis segment; All angle parameters and their relationships are integrated into a unified parameter structure for subsequent calculations.

[0012] Preferably, based on the equivalent model construction process, the transformation path from multi-segment transmission relationships to a single expression form is limited to highlight the uniformity of model expression. The steps are as follows: right , , and , , Perform variable normalization and construct a unified input vector; Substitute the normalized variables into the equivalent angle calculation expression to form a unified calculation interface; An initial phase parameter is introduced during the calculation process to perform phase correction on the input vector; Output a single equivalent included angle through the calculation interface. And form an equivalent expression result.

[0013] Preferably, the angle variables in the unified parameter structure are formatted and standardized, a corresponding mapping rule between angle input and calculation expression is established, the angle index mapping table, the plane angle association set and the phase angle matching relationship are uniformly encapsulated, and the parameter reading and transmission are completed through a standardized interface to maintain the consistent expression and stability of the association relationship of angle parameters in the calculation process.

[0014] Preferably, the iterative optimization mechanism is constrained by combining the dynamic parameter adjustment process, emphasizing the continuous update relationship in the multi-round calculation process, and the steps are as follows: Set the initial parameter combination, perform equivalent angle and torque fluctuation calculations, and record the initial results; Incremental changes are performed on a single variable in the parameter combination, while keeping other variables unchanged, to generate a new set of parameters; The updated parameter set is re-entered into the calculation expression to obtain the new θe and torque fluctuation results, and the data is recorded. The parameter update and calculation process is repeated to form a multi-round data sequence.

[0015] Preferably, to meet the requirements of torque fluctuation control, the performance evaluation method is limited, and the judgment logic in the parameter selection process is clarified. The steps are as follows: Define the target range for torque fluctuation and construct the corresponding set of judgment rules; The calculated torque fluctuation data are compared one by one with the judgment rules, and the data items that meet the conditions are marked. Unlabeled data items are removed, and the data set that meets the criteria is retained; The filtered dataset is associated with the corresponding parameter combinations and output to form the final parameter result set.

[0016] The technical effects and advantages provided by the present invention in the above technical solution are as follows: This invention addresses the adaptability issue of multi-segment universal joint drives in complex spatial arrangements. By introducing a three-cross-shaft universal joint drive system and combining it with torque fluctuation optimization methods, it enables greater flexibility in the spatial layout of the steering control device. Compared to the strict requirements of the traditional double-cross-shaft structure regarding axis angle and phase matching, this solution achieves performance optimization under more relaxed geometric constraints, effectively adapting to the varying spatial requirements of the vehicle layout. Simultaneously, during the steering system design process, the hard point position of the steering wheel and the steering column inclination angle are more aligned with ergonomic requirements, resulting in more natural and comfortable driver operation and an improved overall driving experience.

[0017] This invention optimizes the multi-parameter coupling relationship, enabling effective control of torque fluctuations in the steering transmission path while satisfying layout constraints, thereby reducing performance losses caused by unreasonable spatial arrangement. This solution reduces the restrictions imposed by peripheral systems (such as body structure and powertrain) on the arrangement of steering control devices, allowing for greater design freedom and facilitating the coordinated optimization of the entire vehicle system. Furthermore, while ensuring transmission performance, this optimization method helps improve the smoothness and stability of the steering process, reduces the impact of torque fluctuations on driving feel, and thus enhances the overall vehicle quality and reliability. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0019] Figure 1 This is a schematic diagram of the double cross-shaft universal joint transmission of the present invention.

[0020] Figure 2 This is a schematic diagram of the three-cross universal joint transmission of the present invention.

[0021] Figure 3 This is a schematic diagram of the three-cross universal joint structure of the present invention.

[0022] Figure 4 This is a schematic diagram of the ball bearing support structure of the present invention.

[0023] Illustration: 1. Steering column assembly; 2. Intermediate shaft I; 3. Output shaft; 4. Intermediate shaft II; 5. Front bulkhead support ball bearing sleeve; 5.1. Front bulkhead support ball bearing upper sleeve; 5.2. Front bulkhead support ball bearing lower sleeve; 6. Front bulkhead support ball bearing; 7. Universal joint. Detailed Implementation

[0024] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, they are provided so that the description of this disclosure will be more complete and fully convey the concept of the exemplary embodiments to those skilled in the art.

[0025] This invention provides, for example Figure 1 - Figure 4 The method for optimizing torque fluctuation in a three-way universal joint, as shown, includes the following steps: By defining and parametrically describing the spatial geometric relationships of the multi-segment transmission structure, accurate modeling of complex transmission paths is achieved. The overall structure consists of multiple drive shafts and their connections, with power transmission between the segments achieved through universal joints, thus adapting to steering requirements under different spatial layout conditions.

[0026] In this transmission system, the steering column serves as the power input end, assuming the function of inputting torque and steering angle applied by the driver; intermediate shafts I and II serve as intermediate transmission units, used to achieve torque transition and direction adjustment in space; and the output shaft serves as the power output end, transmitting torque to the subsequent steering actuator. Through the series connection between multiple shafts, the entire system can achieve an effective power transmission path under complex spatial constraints.

[0027] To ensure structural stability and motion reliability during transmission, a support structure is installed at the front bulkhead opening. This support structure includes a ball bearing sleeve and a ball bearing. The ball bearing provides radial support and rotational guidance, while the sleeve is used for bearing mounting, positioning, and protection, thereby ensuring good support rigidity and motion stability of the intermediate drive shaft when passing through the vehicle body structure. This support method effectively avoids vibration and sway problems caused by excessively long shaft cantilever or uneven stress.

[0028] In defining spatial geometric relationships, the entire transmission system is precisely described by introducing multiple planes and their interrelationships. Specifically, three key axial planes are defined: Plane SI is formed by the steering column and intermediate shaft I, and this plane reflects the spatial relationship between the input end and the first intermediate drive shaft. Plane SII is formed by intermediate shaft I and intermediate shaft II, and this plane describes the transition relationship in the intermediate transmission path; Plane SIII is formed by intermediate shaft II and output shaft. This plane is used to depict the spatial relationship between the final output direction and the preceding drive.

[0029] By defining the three planes mentioned above, the originally complex three-dimensional spatial transmission relationship can be decomposed into multiple local planar relationships, which facilitates subsequent analysis and calculation.

[0030] Regarding the axial geometry, a quantitative description of the spatial transmission path is achieved by defining the included angles between each segment of the axis. Specifically: This parameter indicates the angle between the steering column and intermediate shaft I, reflecting the degree of deflection between the input transmission direction and the first intermediate shaft. This parameter represents the included angle between the axes of intermediate shaft I and intermediate shaft II. This parameter is used to describe the degree of spatial curvature of the intermediate transmission path. This parameter represents the angle between the intermediate shaft II and the output shaft, reflecting the deflection of the final output direction relative to the intermediate transmission path.

[0031] The three included angle parameters mentioned above together determine the spatial shape of the entire transmission system, and their values ​​directly affect the motion characteristics and torque transmission characteristics of the universal joint.

[0032] Besides the included angle of the axes, the relative relationship between the planes also has a significant impact on the transmission characteristics. Therefore, a plane angle parameter is introduced: It represents the angle between plane SI and plane SII, used to describe the torsional relationship between the input segment and the intermediate segment. It represents the angle between plane SII and plane SIII, used to reflect the spatial torsional relationship between the intermediate section and the output section.

[0033] pass and The definition of a plane can fully describe the spatial relative positional relationship between three planes, thus providing a basis for subsequent analysis of the coupling relationship between universal joints.

[0034] During the installation and assembly of universal joints, the phase relationship is a crucial factor affecting transmission performance. Therefore, a phase angle parameter is introduced to describe the relative position between the universal joint forks. Wherein: This parameter represents the angle between the universal joint fork plane at the output end of intermediate shaft I and the universal joint fork plane of the steering column. This parameter reflects the phase matching relationship between the first set of universal joints. This parameter represents the angle between the universal joint fork plane at the output end of intermediate shaft II and the universal joint fork plane of intermediate shaft I. This parameter is used to describe the phase relationship between the two sets of universal joints.

[0035] Phase angle and The value of directly affects the motion superposition effect between the universal joints at each level, thus having a significant impact on the speed uniformity and torque fluctuation of the overall transmission.

[0036] By establishing the aforementioned parameter system, the three-way universal joint transmission structure can be fully parameterized. Compared to the traditional double universal joint structure, this system introduces more degrees of freedom, making spatial arrangement more flexible, but also increasing system complexity. The parameters do not exist independently, but are coupled together through spatial geometric relationships, jointly determining the overall performance of the transmission system.

[0037] From an engineering perspective, , , It mainly determines the macroscopic spatial shape of the transmission path, while , This further describes the spatial twisting relationship between the segments. , These parameters are used to adjust the phase matching between universal joints. By combining and optimizing these parameters appropriately, the motion characteristics during transmission can be improved while meeting spatial constraints.

[0038] Furthermore, the ball bearing support structure not only enhances the structural rigidity of the system but also reduces vibration and impact during transmission to a certain extent, thus contributing to improved overall system stability. This is particularly important for multi-stage transmission structures, as the system's sensitivity to support conditions increases with the number of transmission stages.

[0039] Overall, this technical solution, by constructing a complete spatial parameter system, accurately describes the three-way universal joint transmission structure, transforming the complex spatial transmission problem into an analyzable and controllable parametric problem. This parametric modeling approach provides the foundation for subsequent torque fluctuation analysis and optimization, and also offers effective theoretical support for the design and layout of complex steering systems.

[0040] The transmission structure of the three-cross universal joint steering control device is as follows: Figure 3 As shown, its core lies in the effective transmission of driver input torque through the series connection of multiple shaft segments and universal joints in a complex spatial path. The entire transmission path unfolds sequentially from the input end to the output end, forming a continuous power transmission chain, thereby ensuring the continuity and reliability of steering operation.

[0041] In actual operation, the driver applies torque and steering angle through the steering wheel, and this input first acts on the steering column. As the input end of the entire system, the steering column not only undertakes the function of torque input, but also serves as the starting reference for transmitting motion; its motion state directly determines the response characteristics of subsequent transmission segments. The rotational motion of the steering column is transmitted to the intermediate shaft I through the first set of universal joints. During this process, due to the included angle of the axes, the universal joints play a role in changing the direction of torque transmission, allowing the torque to continue to be transmitted along different spatial directions.

[0042] Intermediate shaft I, as a crucial transitional component connecting the steering column and intermediate shaft II, primarily serves to receive torque from the input end and further adjust the transmission path direction through its spatial arrangement. Since this shaft segment is typically located within the vehicle body structure, its placement must balance space constraints and transmission efficiency; therefore, its position and angle design have a significant impact on the overall system.

[0043] Subsequently, the torque is transmitted to intermediate shaft II via the second set of universal joints. Compared to the double cross-shaft structure, the triple cross-shaft structure adds intermediate shaft II as a transmission segment, making the entire system a multi-stage transmission. The introduction of this structure significantly improves the system's adaptability in complex spatial environments, enabling the steering system to bypass obstacles or meet specific layout requirements. However, with the increase in the number of transmission segments, the requirements for structural stability during power transmission also increase.

[0044] Intermediate shaft II further transmits torque to the output shaft, which, as the final transmission segment, outputs torque to the steering assembly, thereby driving the wheels to rotate and realizing the vehicle's steering function. The entire transmission path forms a continuous link of steering column—intermediate shaft I—intermediate shaft II—output shaft, with each segment connected by universal joints to achieve multi-angle, multi-directional spatial transmission.

[0045] The addition of intermediate shaft II to this structure increases the overall shaft system length and makes the structure more complex. Without effective support during transmission, it is prone to vibration, swaying, and even localized instability. Therefore, a support structure is installed at the location where the steering control device passes through the front bulkhead hole. Ball bearings are introduced to support the shaft system, thereby improving the overall structural stability.

[0046] Specifically, a ball bearing 6 is installed at the front bore. The ball bearing provides radial support to the intermediate shaft and allows the shaft system to maintain a low-friction state during rotation, thereby ensuring transmission efficiency. The introduction of the ball bearing not only limits the radial displacement of the shaft system but also effectively reduces vibration problems caused by shaft eccentricity or uneven force, thus improving the smoothness of the transmission system.

[0047] To ensure the stability and reliability of the ball bearing during use, a dedicated protective sleeve structure is installed on its exterior. This protective sleeve structure includes an upper sleeve 5.1 and a lower sleeve 5.2, which together form a complete bearing mounting cavity. The upper sleeve is mainly used for upper positioning and fixing of the ball bearing, while the lower sleeve provides lower support. Together, they securely mount the ball bearing at the front bore position.

[0048] The sheathing structure effectively prevents ball bearings from shifting or loosening during long-term use, while also providing some protection against external environmental factors (such as dust and moisture) that could affect bearing performance. Furthermore, the sheathing structure can distribute the stress on the shaft system to a certain extent, improving the overall durability of the structure.

[0049] Under the support of this structure, intermediate shaft I and intermediate shaft II can maintain a stable spatial position during transmission, thereby avoiding additional vibrations or torque fluctuations caused by shaft misalignment. This is especially critical for multi-segment transmission structures, because instability in any segment will be transmitted and amplified through the universal joint, ultimately affecting the performance of the entire system.

[0050] From an overall structural perspective, this three-way universal joint steering control device, by adding an intermediate shaft II, achieves multi-segment decomposition of the transmission path, enabling the system to adapt to more complex spatial layout requirements. Simultaneously, the introduction of ball bearing support structures at key locations significantly improves the system's structural stability and operational reliability.

[0051] Furthermore, the combination of multi-segment shafts and universal joints allows for flexible torque transmission in multiple directions. This structural design not only meets spatial arrangement requirements but also provides more adjustable parameters for subsequent torque fluctuation optimization. The relative positional, angular, and phase relationships between each transmission segment can all be optimized during the design phase to achieve superior transmission performance.

[0052] In summary, this structure, through the rational configuration of the connection between the multi-segment drive shaft and the universal joint, and combined with the support structure design at the front hole, not only ensures the realization of the steering function, but also improves the system's adaptability and operational stability under complex spatial conditions, providing a reliable structural foundation for the engineering application of multi-segment universal joint drive systems.

[0053] In spatial transmission systems, the motion characteristics of universal joints directly determine the consistency of speed between input and output, as well as the stability of torque transmission. Different types of universal joints exhibit significantly different motion patterns under different spatial conditions; therefore, their transmission characteristics need to be constrained and analyzed through explicit geometric conditions.

[0054] For a single universal joint, the prerequisite for achieving constant velocity motion is that there is no spatial angle between the input and output shafts, meaning the two shafts remain collinear or coplanar. Under this condition, no angular velocity fluctuations occur during universal joint transmission, thus ensuring consistency in motion between the input and output. This condition can be expressed as: in, This indicates the angle between the input and output axes. When the value is zero, it means that the two shafts are fully aligned. At this time, the universal joint no longer produces non-uniform velocity effects, and the transmission process is in an ideal state.

[0055] However, in practical engineering applications, due to space constraints, the input and output shafts often have a certain angle, making a single universal joint insufficient for practical needs. Therefore, a double universal joint transmission is introduced. By combining two universal joints, approximately constant velocity transmission can be achieved under certain conditions. This constant velocity condition requires satisfying the following two constraints: in: This indicates the phase angle between the universal joint forks at both ends of the intermediate shaft; This represents the angle between the plane formed by the input shaft and the intermediate shaft and the plane formed by the output shaft and the intermediate shaft.

[0056] The above two conditions constrain the transmission system from the perspectives of axial geometry and phase matching, respectively. When and When they are equal, the spatial deflection of the two transmission paths remains consistent; when equal At this time, the phase relationship between the two sets of universal joints can achieve mutual cancellation of velocity fluctuations. When both of these conditions are met, the dual universal joint system can be approximately equivalent to a single universal joint with a fixed included angle, and its motion tends to be uniform.

[0057] In situations with more complex spatial conditions, a three-way universal joint transmission is adopted. This design adds an extra transmission link to the double universal joint system, enabling it to adapt to more complex spatial paths. However, due to the increased number of transmission segments, the number of angular parameters involved in the system increases significantly, making motion law analysis more complex.

[0058] To unify the analysis of the motion characteristics of multi-segment universal joint systems, an equivalent included angle is introduced. The concept of a universal joint. Using this parameter, a three-way cross-shaped universal joint can be equivalent to a single universal joint, thus transforming a complex problem into a single-parameter problem for processing. Equivalent angle. The calculation formula is as follows: As can be seen from the formula structure, the equivalent included angle It consists of two parts: the first part is a combination of cosine terms, and the second part is a combination of sine terms. These two parts reflect the influence of different angular relationships on the system's motion characteristics. The coupling relationship between multiple angular parameters is expressed through the combination of square terms and trigonometric functions.

[0059] Obtaining the equivalent included angle Next, the torque fluctuation can be calculated, and its expression is as follows: This formula shows that the torque fluctuation is related to the equivalent angle. There is a non-linear relationship between them. Specifically: It reflects the fundamental impact of angle changes on velocity fluctuations; This reflects the contribution of perspective change to the nonlinear magnification effect; multiplying by 100 converts the result to a percentage. when When approaching zero, and All tend to zero, at which point the torque fluctuation is close to zero, and the transmission state is close to an ideal constant velocity state; as As the torque increases, torque fluctuations will increase significantly, indicating that there is a large speed non-uniformity in the transmission process.

[0060] As can be seen from the above formula, the magnitude of torque fluctuation mainly depends on ,and And from , , , , , , These parameters are jointly determined. Therefore, by making reasonable adjustments to these parameters, torque fluctuations can be controlled.

[0061] In practical applications, due to limitations in space layout, It is usually difficult to make it exactly zero, therefore it is necessary to make it equal to zero while satisfying the layout constraints. Minimize it as much as possible. In general engineering, torque fluctuations are controlled within the following range: Under this constraint, by adjusting 、 、 as well as 、 The combination of these parameters allows for optimized control of torque fluctuations. Because of the coupling relationship between these parameters, the interaction between multiple variables needs to be comprehensively considered during the adjustment process.

[0062] In summary, by establishing the equivalent included angle The computational model, combined with the torque fluctuation calculation formula, can transform the complex three-way universal joint transmission problem into a quantifiable analysis problem, thus providing a theoretical basis for subsequent optimization and effective guidance for transmission design under complex spatial conditions.

[0063] This invention addresses the adaptability issue of multi-segment universal joint drives in complex spatial arrangements. By introducing a three-cross-shaft universal joint drive system and combining it with torque fluctuation optimization methods, it enables greater flexibility in the spatial layout of the steering control device. Compared to the strict requirements of the traditional double-cross-shaft structure regarding axis angle and phase matching, this solution achieves performance optimization under more relaxed geometric constraints, effectively adapting to the varying spatial requirements of the vehicle layout. Simultaneously, during the steering system design process, the hard point position of the steering wheel and the steering column inclination angle are more aligned with ergonomic requirements, resulting in more natural and comfortable driver operation and an improved overall driving experience.

[0064] This invention optimizes the multi-parameter coupling relationship, enabling effective control of torque fluctuations in the steering transmission path while satisfying layout constraints, thereby reducing performance losses caused by unreasonable spatial arrangement. This solution reduces the restrictions imposed by peripheral systems (such as body structure and powertrain) on the arrangement of steering control devices, allowing for greater design freedom and facilitating the coordinated optimization of the entire vehicle system. Furthermore, while ensuring transmission performance, this optimization method helps improve the smoothness and stability of the steering process, reduces the impact of torque fluctuations on driving feel, and thus enhances the overall vehicle quality and reliability. The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A method for optimizing torque fluctuation in a three-way universal joint, characterized in that, Includes the following steps: Define the parameters of the three-way universal joint transmission relationship and establish the included angle between the input shaft and intermediate shaft I. The included angle between intermediate axis I and intermediate axis II The angle between intermediate shaft II and output shaft and the corresponding phase angle , and plane angle , Determine the spatial geometric relationship between them and determine the initial range of values ​​for each parameter; Based on spatial geometric relationships, an equivalent analysis model of the three-way universal joint transmission is constructed, transforming the three-way universal joint transmission into one with an equivalent included angle. The single universal joint drive form with initial phase is used to characterize the motion relationship between the input shaft and the output shaft; Based on the equivalent analysis model, combined with , , , , and , The functional relationship between them is used to calculate the equivalent angle. And establish the equivalent included angle The correspondence between the parameters; Obtaining the equivalent included angle Based on the torque fluctuation and the equivalent angle The calculation relationship between them is used to calculate and quantify the torque fluctuation during the transmission process of the three-way universal joint; Based on the calculation results of torque fluctuation, for , , and , Adjustments are made, and the equivalent angle is continuously called during the adjustment process. Iterative analysis of the torque fluctuation calculation results is performed to reduce the equivalent angle. And reduce torque fluctuations.

2. The method for optimizing torque fluctuation in a three-way universal joint according to claim 1, characterized in that, To ensure the completeness of the equivalent angle calculation, and to limit the multi-parameter coupling relationship, the steps to strengthen the correlation between angle combination terms are as follows: right , , Perform a unified angle system conversion and execute squaring operations separately, while constructing an initial data set containing each angle variable; right and Perform difference calculation to generate the first angle difference variable, and input the variable into the cosine and sine function calculation module to obtain the corresponding trigonometric function value sequence; Will and The values ​​are superimposed on the first angle difference variable to generate the second angle difference variable, and then the cosine and sine functions are applied to this variable respectively to form an extended trigonometric function value set. Perform a weighted combination operation on all trigonometric function values, and then perform fourth root processing on the combination result to output the equivalent included angle. The calculation results.

3. The method for optimizing torque fluctuation in a three-way universal joint according to claim 2, characterized in that, The calculation path for torque fluctuation is developed by constraining the functional relationship between the equivalent angle and the fluctuation amount, and clarifying the calculation expression logic. The steps are as follows: Input equivalent angle Convert to radian representation and construct a single-variable input data structure; right Perform sine function calculation, generate the first intermediate calculated value, and record the corresponding angle position; For the same Perform tangent function calculation to generate a second intermediate calculated value and establish a correspondence between it and the first intermediate calculated value; By multiplying the two intermediate calculated values ​​and amplifying the result using a scaling factor, a numerical expression of torque fluctuation is obtained.

4. The method for optimizing torque fluctuation in a three-way universal joint according to claim 3, characterized in that, Based on the characteristics of multivariate coordinated change, the parameter adjustment strategy is refined to highlight the linkage between parameters from different perspectives. The steps are as follows: right , , Set the value range and discretize each range according to the preset step size to generate an angle parameter grid set; right and The interval is divided, and multiple phase combination sequences are generated at fixed intervals; the angle parameter grid set and the phase combination sequence are combined by Cartesian product to form a complete parameter combination matrix; Input each parameter combination into the equivalent angle calculation expression one by one to obtain the corresponding... The results are collected and stored.

5. The method for optimizing torque fluctuation in a three-way universal joint according to claim 4, characterized in that, The equivalent angles in the parameter combination matrix The result set is filtered and sorted according to a preset sorting rule. Arrange the values, extract the subset of parameter combinations that satisfy the minimization trend, and assign the corresponding values ​​of this parameter combination subset to the appropriate values. , , , and Perform association mapping to form a set of constraints for subsequent parameter adjustments.

6. The method for optimizing torque fluctuation in a three-way universal joint according to claim 4, characterized in that, To ensure consistency in the expression of spatial geometric relationships, the angular parameter system is further explained, and the logical connections between various angles are strengthened. The steps are as follows: right , , Perform unified variable numbering and establish an angle index mapping table; Will and Each angle is associated with its corresponding angle index to construct a set of correspondences between plane angles and the angle between the axes; right and Number and classify them, and establish the matching relationship between phase angle and corresponding axis segment; All angle parameters and their relationships are integrated into a unified parameter structure for subsequent calculations.

7. The method for optimizing torque fluctuation in a three-way universal joint according to claim 6, characterized in that, Based on the equivalent model construction process, the transformation path from multi-segment transmission relationships to a single expression is limited, highlighting the uniformity of model expression. The steps are as follows: right , , and , , Perform variable normalization and construct a unified input vector; Substitute the normalized variables into the equivalent angle calculation expression to form a unified calculation interface; An initial phase parameter is introduced during the calculation process to perform phase correction on the input vector; Output a single equivalent included angle through the calculation interface. And form an equivalent expression result.

8. The method for optimizing torque fluctuation in a three-way universal joint according to claim 7, characterized in that, The format of each angle variable in the unified parameter structure is standardized, a corresponding mapping rule between angle input and calculation expression is established, the angle index mapping table, the plane angle association set and the phase angle matching relationship are uniformly encapsulated, and the parameter reading and transmission are completed through a standardized interface to maintain the consistent expression and stability of the association relationship of angle parameters in the calculation process.

9. The method for optimizing torque fluctuation in a three-way universal joint according to claim 7, characterized in that, By incorporating the dynamic parameter adjustment process, constraints are imposed on the iterative optimization mechanism, emphasizing the continuous update relationship in multiple rounds of computation. The steps are as follows: Set the initial parameter combination, perform equivalent angle and torque fluctuation calculations, and record the initial results; Incremental changes are performed on a single variable in the parameter combination, while keeping other variables unchanged, to generate a new set of parameters; The updated parameter set is re-entered into the calculation expression to obtain the new θe and torque fluctuation results, and the data is recorded. The parameter update and calculation process is repeated to form a multi-round data sequence.

10. The method for optimizing torque fluctuation in a three-way universal joint according to claim 7, characterized in that, To address the requirements for torque fluctuation control, the performance evaluation method is limited, and the judgment logic in the parameter selection process is clarified. The steps are as follows: Define the target range for torque fluctuation and construct the corresponding set of judgment rules; The calculated torque fluctuation data are compared one by one with the judgment rules, and the data items that meet the conditions are marked. Unlabeled data items are removed, and the data set that meets the criteria is retained; The filtered dataset is associated with the corresponding parameter combinations and output to form the final parameter result set.

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