Design method of non-independent chassis steering mechanism

Abstract

The invention provides a design method of a non-independent chassis steering mechanism, which belongs to the technical field of vehicle chassis design, and comprises the following steps: building a vehicle body linear framework according to the overall arrangement of a whole vehicle, decomposing the vehicle body linear framework into independent part linear models by using computer-aided software, and reserving a connection relationship; building a mechanical device model and a kinematic pair model based on a digital model motion module; building a vehicle body motion model; collecting model vehicle parameters; calculating the minimum turning radius of a simulated vehicle, the Ackerman turning angle of the simulated vehicle and the number of turns of a steering wheel of the simulated vehicle; when the design requirement of the vehicle body steering mechanism is met, a chassis steering model is built, the interference condition is detected, and when the chassis steering design condition is met, the chassis steering model is output. According to the method, the chassis steering model is constructed by adjusting the linear frame of the vehicle body, so that hard point arrangement and wireframe adjustment are simpler and more convenient, and the method is suitable for chassis steering mechanism design of different vehicle types.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle chassis design, in particular to a non-independent chassis steering mechanism design method. BACKGROUND

[0002] At present, in the non-independent chassis steering design process, the steering hard point needs to be frequently adjusted to meet the appropriate wheel turning angle and Ackermann angle. If the wheel turning angle is too small, the vehicle passability is poor, and a better turning radius cannot be obtained. If the wheel turning angle is too large, the tire rolling causes the tire wear to be more serious, especially the second axle tire wear of the double front axle chassis is more serious. The too high or too low Ackermann angle will affect the handling and stability. If it is too low, the inner side wheel turning angle is smaller than the outer side wheel turning angle, so that the inner side wheel grip is insufficient, and the tail sliding phenomenon is easy to occur. If it is too high, the inner side wheel turning angle is larger than the outer side wheel turning angle, so that the outer side wheel grip is insufficient, and the head pushing phenomenon is easy to occur. At the same time, the too high Ackermann angle will increase the tire wear and shorten the tire service life.

[0003] In the traditional technology, the Excel table is used for hard point arrangement, the Ackermann angle related parameters are calculated, and the model is completed. However, the table calculation process is complex, there are many numerical variables, which is not conducive to hard point adjustment. When the steering linkage arrangement structure changes, the table formula needs to be re-edited, which is time-consuming and laborious. The calculation process is not intuitive and easy to make mistakes, and the later model adjustment is complex.

[0004] The steering mechanism hard point arrangement relates to the length of the pull rod and the spatial position of the pull rod in the whole vehicle coordinate system, which will affect the stress and surrounding interference of the pull rod. In the forward development process, the construction of the vehicle body three-dimensional model needs to be completed, and then the hard point and structure model are adjusted, which leads to a long model building time period and affects the vehicle development progress.

[0005] Due to various types of vehicle models, the steering linkage arrangement structure and arrangement method of different platforms and different vehicle models are different. The related parameters such as vertical arm swing angle, wheelbase length, axle form and wheel tread size are different. The Excel table method cannot be used to quickly realize the design of the steering mechanism.

[0006] Therefore, a non-independent chassis steering mechanism design method is proposed. SUMMARY

[0007] To solve the above technical problems, the present application provides a non-independent chassis steering mechanism design method to solve the problems that the chassis steering mechanism design time period is long, the model building complexity is high, and it is difficult to meet the chassis steering mechanism design of different vehicle models with different wheelbase in the traditional technology.

[0008] The embodiment of the present application provides a non-independent chassis steering mechanism design method, comprising:

[0009] According to the automobile overall arrangement, a vehicle body linear frame is built based on a vehicle body coordinate system;

[0010] The vehicle body linear frame is decomposed into a plurality of independent part linear models by using computer-aided software, the connection relationship between the part linear models is reserved, and based on a digital model motion module, corresponding mechanical device models and motion pair models are established according to the part linear models and the connection relationship;

[0011] According to the mechanical device models and the motion pair models, a vehicle body motion model is constructed;

[0012] According to the vehicle body motion model, model vehicle parameters are collected, and the minimum turning radius of the simulation vehicle, the Ackerman turning angle of the simulation vehicle and the steering wheel number of the simulation vehicle are calculated;

[0013] According to the minimum turning radius of the simulation vehicle, the Ackerman turning angle of the simulation vehicle and the steering wheel number of the simulation vehicle, whether the vehicle body motion model meets the design requirements of the vehicle body steering mechanism is analyzed, and when the vehicle body motion model meets the design requirements of the vehicle body steering mechanism, a chassis steering model is built according to the vehicle body linear frame;

[0014] The interference of each part model in the chassis steering model is detected, and when the chassis steering design condition is met, the chassis steering model is output.

[0015] Preferably, the present application provides a non-independent chassis steering mechanism design method, and the step of building a vehicle body linear frame based on a vehicle body coordinate system according to the automobile overall arrangement comprises:

[0016] The automobile overall arrangement is obtained, including the overall vehicle wheelbase, the front axle track, the frame width and the wheel center height;

[0017] Based on the vehicle body coordinate system, the arrangement positions of each mechanism model of the automobile are determined according to the automobile overall arrangement, and the vehicle body linear frame is built under the fixed axis arrangement constraint condition and the length constraint condition of the rod system.

[0018] Preferably, the present application provides a non-independent chassis steering mechanism design method, and the step of collecting model vehicle parameters, calculating the minimum turning radius of the simulation vehicle, the Ackerman turning angle of the simulation vehicle and the steering wheel number of the simulation vehicle according to the vehicle body motion model comprises:

[0019] According to the vehicle body motion model, the first steering bridge to the instantaneous steering center line distance parameter, the vehicle direction maximum turning angle parameter and the kingpin offset distance parameter are collected, and the minimum turning radius of the simulation vehicle is calculated;

[0020]

[0021] Wherein, R is the minimum turning radius of the simulation vehicle, L is the first steering axle to instantaneous steering centerline distance parameter, Ψ is the maximum turning angle of the vehicle direction parameter, C is the kingpin offset distance parameter.

[0022] Preferably, the present application provides a non-independent chassis steering mechanism design method, said steps: according to the vehicle motion model, collecting model vehicle parameters, calculating the minimum turning radius of the simulation vehicle, the Ackerman angle of the simulation vehicle and the number of steering wheel turns of the simulation vehicle; comprising:

[0023] According to the vehicle motion model, collecting the outer front wheel turning angle parameter, the inner front wheel turning angle parameter, the outer front wheel turning angle parameter, the inner front wheel turning angle parameter, the one axle kingpin axis and ground intersection distance parameter, the two axle kingpin axis and ground intersection distance parameter, the one-two axle distance parameter, the two-three axle distance parameter, the three-four axle distance parameter, calculating the one axle Ackerman angle difference value of the simulation vehicle and the two axle Ackerman angle difference value of the simulation vehicle;

[0024]

[0025] Wherein, e1 is the one axle Ackerman angle difference value of the simulation vehicle, θ1 is the outer front wheel turning angle parameter, θ2 is the inner front wheel turning angle parameter, K1 is the one axle kingpin axis and ground intersection distance parameter, L1 is the one-two axle distance parameter, L2 is the two-three axle distance parameter, L3 is the three-four axle distance parameter;

[0026] Wherein, e2 is the two axle Ackerman angle difference value of the simulation vehicle, θ3 is the outer front wheel turning angle parameter, θ4 is the inner front wheel turning angle parameter, K2 is the two axle kingpin axis and ground intersection distance parameter.

[0027] Preferably, the present application provides a non-independent chassis steering mechanism design method, said steps: according to the vehicle motion model, collecting model vehicle parameters, calculating the minimum turning radius of the simulation vehicle, the Ackerman angle of the simulation vehicle and the number of steering wheel turns of the simulation vehicle; comprising:

[0028] According to the vehicle motion model, collecting the outer front wheel turning angle parameter, the inner front wheel turning angle parameter, the outer front wheel turning angle parameter, the inner front wheel turning angle parameter, the one axle kingpin axis and ground intersection distance parameter, the two axle kingpin axis and ground intersection distance parameter, the one-two axle distance parameter, the two-three axle distance parameter, the three-four axle distance parameter, calculating the one axle Ackerman angle difference value of the simulation vehicle and the two axle Ackerman angle difference value of the simulation vehicle;

[0029]

[0030] Wherein, n is the number of steering wheel turns of the simulation vehicle, θ is the outer front wheel turning angle parameter, i is the steering gear transmission ratio parameter.

[0031] Preferably, the application provides a non-independent chassis steering mechanism design method, the steps: according to the minimum turning radius of the simulation vehicle, the Ackerman angle of the simulation vehicle, the number of turns of the steering wheel of the simulation vehicle, analyze whether the vehicle motion model meets the vehicle steering mechanism design requirements, when the vehicle motion model meets the vehicle steering mechanism design requirements, according to the linear frame of the vehicle body, build a chassis steering model; comprising:

[0032] Analyze whether the vehicle motion model meets the vehicle steering mechanism design requirements, when the vehicle motion model does not meet the vehicle steering mechanism design requirements, rebuild the linear frame of the vehicle body, and rebuild the vehicle motion model through computer-aided software processing;

[0033] According to the secondly constructed vehicle motion model, the minimum turning radius of the simulation vehicle, the Ackerman angle of the simulation vehicle, and the number of turns of the steering wheel of the simulation vehicle are recalculated until the vehicle motion model meets the vehicle steering mechanism design requirements, and the chassis steering model is built.

[0034] Compared with the prior art, the application has the beneficial effects that: a non-independent chassis steering mechanism design method, by adjusting and optimizing the linear frame of the vehicle body, a chassis steering model is constructed, so that the hard point arrangement and the frame adjustment are more convenient, the process of repeated modeling is reduced, the design complexity is reduced, the rapid design of the chassis steering mechanism is realized through the method of combining computer-aided software with numerical calculation, the vehicle motion model obtained by the computer-aided software can accurately simulate the motion state and motion envelope of each part, output the minimum turning radius of the simulation vehicle, the Ackerman angle of the simulation vehicle, and the number of turns of the steering wheel of the simulation vehicle, solve the problem of complex and time-consuming table calculation, when the parameters output by the vehicle motion model meet the design requirements of the steering mechanism, the model is built again, avoiding the problem of unchanged model adjustment and long modeling time period, thereby speeding up the development progress of the vehicle model, and the method of constructing the chassis steering model according to the linear frame of the vehicle body makes the method applicable to the design of steering mechanisms of different platforms and different vehicle models, further improving the applicability of the method in the design of the chassis steering mechanism.

[0035] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the present application. The objects and other advantages of the present application can be realized and attained by the structure particularly pointed out in the written description and claims, and the appended drawings.

[0036] The technical solutions of the present application will be further described in detail below with the help of the drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1Flowchart of the non-independent chassis steering mechanism design method of the present application;

[0038] Figure 2 Vehicle linear frame structure diagram of the non-independent chassis steering mechanism design method of the present application;

[0039] Figure 3 Kinematic pair model structure diagram of the non-independent chassis steering mechanism design method of the present application;

[0040] Figure 4 An example 8x4 non-independent chassis steering model diagram of the non-independent chassis steering mechanism design method of the present application.

[0041] Explanation of reference signs:

[0042] 21 - steered output axis, 22 - drop arm axis, 23 - steering straight link 1 axis, 24 - steering rocker 1 axis, 25 - one axle steering link axis, 26 - one axle knuckle axis, 27 - one axle left kingpin axis, 28 - steering straight link 2 axis, 29 - one axle left trapezoidal arm axis, 210 - one axle tie rod axis, 211 - one axle right trapezoidal arm axis, 212 - one axle right kingpin axis, 213 - steering rocker 2 axis, 214 - two axle steering link axis, 215 - two axle knuckle axis, 216 - two axle left kingpin axis, 217 - two axle left trapezoidal arm axis, 218 - two axle tie rod axis, 219 - two axle right trapezoidal arm axis, 220 - two axle right kingpin axis;

[0043] 31 - rotary joint, 32 - universal joint (U-joint), 33 - spherical joint;

[0044] 41 - steered output assembly, 42 - drop arm assembly, 43 - steering straight link 1 assembly, 44 - steering rocker 1 assembly, 45 - one axle steering link assembly, 46 - one axle left wheel assembly, 47 - steering straight link 2 assembly, 48 - one axle tie rod assembly, 49 - one axle right wheel assembly, 410 - steering rocker 2 assembly, 411 - two axle steering link assembly, 412 - two axle left wheel assembly, 413 - two axle tie rod assembly, 414 - two axle right wheel assembly. DETAILED DESCRIPTION

[0045] The preferred embodiments of the present application are described below in conjunction with the accompanying drawings, it should be understood that the preferred embodiments described here are only used to illustrate and explain the present application, and are not used to limit the present application.

[0046] Example 1:

[0047] The embodiment of the present application provides a non-independent chassis steering mechanism design method, referring to Figure 1 , comprising:

[0048] According to the automobile overall arrangement, a vehicle body linear framework is built based on a vehicle body coordinate system;

[0049] The vehicle body linear framework is decomposed into a plurality of independent part linear models by using computer-aided software, the connection relationship between the part linear models is reserved, and a corresponding mechanical device model and a motion pair model are established based on a digital model motion module according to the part linear models and the connection relationship;

[0050] The vehicle body motion model is constructed according to the mechanical device model and the motion pair model;

[0051] According to the vehicle body motion model, model vehicle parameters are collected, and the minimum turning radius of the simulation vehicle, the Ackerman turning angle of the simulation vehicle, and the steering wheel circle number of the simulation vehicle are calculated;

[0052] According to the minimum turning radius of the simulation vehicle, the Ackerman turning angle of the simulation vehicle, and the steering wheel circle number of the simulation vehicle, it is analyzed whether the vehicle body motion model meets the design requirements of the vehicle body steering mechanism, and when the vehicle body motion model meets the design requirements of the vehicle body steering mechanism, a chassis steering model is built according to the vehicle body linear framework;

[0053] The interference of each part model in the chassis steering model is detected, and the chassis steering model is output when the chassis steering design condition is met.

[0054] In the above embodiment, according to the automobile overall arrangement, a vehicle body linear framework is built based on a vehicle body coordinate system, the vehicle body linear framework is decomposed into a plurality of independent part linear models by using computer-aided software, the connection relationship between the part linear models is reserved, and a corresponding mechanical device model and a motion pair model are established based on a digital model motion module according to the part linear models and the connection relationship, and a vehicle body motion model is constructed;

[0055] According to the vehicle body motion model, model vehicle parameters are collected, and the minimum turning radius of the simulation vehicle, the Ackerman turning angle of the simulation vehicle, and the steering wheel circle number of the simulation vehicle are calculated, it is analyzed whether the vehicle body motion model meets the design requirements of the vehicle body steering mechanism, and when the vehicle body motion model meets the design requirements of the vehicle body steering mechanism, a chassis steering model is built according to the vehicle body linear framework, and the interference of each part model in the chassis steering model is detected, and the chassis steering model is output when the chassis steering design condition is met.

[0056] In one embodiment, the vehicle body linear framework built according to the automobile overall arrangement is as shown in Figure 2As shown, the steering gear, the drop arm, the steering straight pull rod 1, the steering rocker arm 1, the front axle steering pull rod, the front axle knuckle, the front axle left kingpin, the steering straight pull rod 2, the front axle left trapezoidal arm, the front axle cross pull rod, the front axle right trapezoidal arm, the front axle right kingpin, the steering rocker arm 2, the rear axle steering pull rod, the rear axle knuckle, the rear axle left kingpin, the rear axle left trapezoidal arm, the rear axle cross pull rod, the rear axle right trapezoidal arm, the rear axle right kingpin in the overall layout of the vehicle are respectively represented by the steering gear output shaft line 21, the drop arm shaft line 22, the steering straight pull rod 1 shaft line 23, the steering rocker arm 1 shaft line 24, the front axle steering pull rod shaft line 25, the front axle knuckle shaft line 26, the front axle left kingpin shaft line 27, the steering straight pull rod 2 shaft line 28, the front axle left trapezoidal arm shaft line 29, the front axle cross pull rod shaft line 210, the front axle right trapezoidal arm shaft line 211, the front axle right kingpin shaft line 212, the steering rocker arm 2 shaft line 213, the rear axle steering pull rod shaft line 214, the rear axle knuckle shaft line 215, the rear axle left kingpin shaft line 216, the rear axle left trapezoidal arm shaft line 217, the rear axle cross pull rod shaft line 218, the rear axle right trapezoidal arm shaft line 219, and the rear axle right kingpin shaft line 220, and a linear frame of the vehicle body is constructed.

[0057] In one embodiment, the kinematic pair model constructed based on the digital model kinematic module is as shown in Figure 3 As shown, the kinematic pair model in the figure includes a rotary joint 31, a general joint (U-shaped joint) 32, and a spherical joint 33.

[0058] In the above embodiment, the computer-aided software can be implemented as CATAI software, and the digital model kinematic module can be implemented as a DMU (digital model accuracy) kinematic module.

[0059] In the above embodiment, the calculation of simulating the minimum turning radius of the vehicle, simulating the Ackerman angle of the vehicle, and simulating the number of turns of the steering wheel is obtained by built-in calculation formulas in the Excel table.

[0060] In one embodiment, referring to Figure 4 The 8x4 non-independent chassis steering model generated by the non-independent chassis steering mechanism design method includes a steering gear assembly 41, a drop arm assembly 42, a steering straight pull rod 1 assembly 43, a steering rocker arm 1 assembly 44, a front axle steering pull rod assembly 45, a front axle left wheel assembly 46, a steering straight pull rod 2 assembly 47, a front axle cross pull rod assembly 48, a front axle right wheel assembly 49, a steering rocker arm 2 assembly 410, a rear axle steering pull rod assembly 411, a rear axle left wheel assembly 412, a rear axle cross pull rod assembly 413, and a rear axle right wheel assembly 414.

[0061] The beneficial effects of the above technology are that: by building a vehicle body linear frame, a vehicle body motion model is generated by computer-aided software, and the detection of the design requirements of the vehicle body steering mechanism is performed by outputting the minimum turning radius of the simulated vehicle, the Ackerman turning angle of the simulated vehicle, and the number of steering wheel turns of the simulated vehicle. When the vehicle body motion model meets the design requirements of the vehicle body steering mechanism, a chassis steering model is built, realizing the rapid construction of the chassis steering model. When the design requirements of the vehicle body steering mechanism are not met, the frame line of the vehicle body linear frame can be adjusted to solve the inconvenience of rebuilding the model in the traditional technology. After obtaining the chassis steering model, the interference of each part model is detected by the digital model motion module to obtain a chassis steering model that meets the design conditions of the chassis steering. Compared with the traditional technology, a non-independent chassis steering mechanism design method adjusts and optimizes the vehicle body linear frame to build a chassis steering model, making the hard point arrangement and line frame adjustment more convenient, reducing the process of repeated modeling, and reducing the design complexity. By combining computer-aided software with numerical calculation, the chassis steering mechanism is quickly designed. The vehicle body motion model obtained by the computer-aided software can accurately simulate the motion state and motion envelope of each part, output the minimum turning radius of the simulated vehicle, the Ackerman turning angle of the simulated vehicle, and the number of steering wheel turns of the simulated vehicle, solving the problem of complex and time-consuming table calculation. When the parameters output by the vehicle body motion model meet the design requirements of the steering mechanism, the model is built again, avoiding the problem of model adjustment and long modeling time period, thereby speeding up the development progress of the vehicle model. Furthermore, the above method builds a chassis steering model based on the vehicle body linear frame, making the method applicable to the design of steering mechanisms of different platforms and different vehicle models, and further improving the applicability of the method in the design of the chassis steering mechanism.

[0062] Embodiment 2:

[0063] The embodiment of the present application provides a non-independent chassis steering mechanism design method, comprising the steps of: building a vehicle body linear frame based on a vehicle body coordinate system according to a vehicle overall arrangement; comprising:

[0064] Obtaining a vehicle overall arrangement, including: vehicle wheelbase, front axle track, vehicle frame width, wheel center height;

[0065] Based on the vehicle body coordinate system, the arrangement positions of each mechanism model of the vehicle are determined according to the vehicle overall arrangement, and the vehicle body linear frame is built under the constraints of fixed axis arrangement and linkage length.

[0066] In the above embodiment, the vehicle body linear frame is built based on the vehicle body coordinate system according to the vehicle overall arrangement. A simple line frame representing each part is established in the vehicle body coordinate system without establishing a three-dimensional model.

[0067] The beneficial effect of the above technology is that by acquiring the vehicle body linear frame built by the overall arrangement of the vehicle, the adjustment of the linear frame position in the vehicle body linear frame is facilitated when the steering mechanism design requirement is not met, the problem of needing to rebuild a three-dimensional model for adjustment in the traditional technology is solved, the convenience of adjusting the vehicle body linear frame is improved, and the efficiency of the chassis steering mechanism design is improved.

[0068] Embodiment 3:

[0069] The embodiment of the present application provides a non-independent chassis steering mechanism design method, steps: acquiring model vehicle parameters according to a vehicle body motion model, calculating a simulated vehicle minimum turning radius, a simulated vehicle Ackerman angle and a simulated vehicle steering wheel number of turns; comprising:

[0070] According to the vehicle body motion model, the first steering bridge to the instantaneous steering center line distance parameter, the vehicle direction maximum turning angle parameter and the kingpin offset distance parameter are collected, and the simulated vehicle minimum turning radius is calculated.

[0071]

[0072] Wherein, R is the simulated vehicle minimum turning radius, L is the first steering bridge to the instantaneous steering center line distance parameter, Ψ is the vehicle direction maximum turning angle parameter, and C is the kingpin offset distance parameter.

[0073] In the above embodiment, the first steering bridge to the instantaneous steering center line distance parameter, the vehicle direction maximum turning angle parameter and the kingpin offset distance parameter in the model vehicle parameters are acquired to calculate the simulated vehicle minimum turning radius.

[0074] In one embodiment, the instantaneous turning center of the double rear axle vehicle type is half of the rear track, because in the actual steering process, the inner and outer wheel turning angles cannot be 100% converged on the instantaneous steering center line, and because of this, the average value of the minimum radii obtained by each inner and outer tire is taken according to the trigonometric function when calculating the actual minimum turning radius.

[0075] The beneficial effect of the above technology is that by acquiring the first steering bridge to the instantaneous steering center line distance parameter, the vehicle direction maximum turning angle parameter and the kingpin offset distance parameter in the model vehicle parameters, the simulated vehicle minimum turning radius is calculated, the design detection of the vehicle body steering mechanism based on the current vehicle body motion model is realized, and the simulated vehicle minimum turning radius of the designed vehicle body motion model is ensured to be within the error allowable range.

[0076] Embodiment 4:

[0077] The embodiment of the present application provides a non-independent chassis steering mechanism design method, steps: acquiring model vehicle parameters according to a vehicle body motion model, calculating a simulated vehicle minimum turning radius, a simulated vehicle Ackerman angle and a simulated vehicle steering wheel number of turns; comprising:

[0078] According to the vehicle body motion model, the outer front wheel rotation angle parameter, the inner front wheel rotation angle parameter, the outer front second wheel rotation angle parameter, the inner front second wheel rotation angle parameter, the one-axle kingpin axis and ground intersection distance parameter, the two-axle kingpin axis and ground intersection distance parameter, the one-two axle distance parameter, the two-three axle distance parameter, and the three-four axle distance parameter are collected, and the simulation vehicle one-axle Ackerman angle difference value and the simulation vehicle two-axle Ackerman angle difference value are calculated.

[0079]

[0080] Wherein, e1 is the simulation vehicle one-axle Ackerman angle difference value, θ1 is the outer front wheel rotation angle parameter, θ2 is the inner front wheel rotation angle parameter, K1 is the one-axle kingpin axis and ground intersection distance parameter, L1 is the one-two axle distance parameter, L2 is the two-three axle distance parameter, and L3 is the three-four axle distance parameter.

[0081] Wherein, e2 is the simulation vehicle two-axle Ackerman angle difference value, θ3 is the outer front second wheel rotation angle parameter, θ4 is the inner front second wheel rotation angle parameter, and K2 is the two-axle kingpin axis and ground intersection distance parameter.

[0082] In the above embodiment, the outer front wheel rotation angle parameter, the inner front wheel rotation angle parameter, the outer front second wheel rotation angle parameter, the inner front second wheel rotation angle parameter, the one-axle kingpin axis and ground intersection distance parameter, the two-axle kingpin axis and ground intersection distance parameter, the one-two axle distance parameter, the two-three axle distance parameter, and the three-four axle distance parameter in the model vehicle parameter are acquired, and the simulation vehicle one-axle Ackerman angle difference value and the simulation vehicle two-axle Ackerman angle difference value are calculated.

[0083] In one embodiment, the instantaneous rotation center of the double rear axle vehicle type is half of the rear axle distance. In the actual design process, due to the limitation of the axle distance and the trapezoidal vehicle bridge, there is a certain difference between the actual and theoretical Ackerman angles, so that the difference is less than 2° at the limit position, and the difference is less than 1° at the intermediate position.

[0084] The above technology has the beneficial effect that by collecting the model vehicle parameters, the simulation vehicle one-axle Ackerman angle difference value and the simulation vehicle two-axle Ackerman angle difference value in the simulation vehicle Ackerman rotation angle are calculated, the design detection of the vehicle body steering mechanism based on the current vehicle body motion model is realized, and the simulation vehicle Ackerman rotation angle of the designed vehicle body motion model is ensured to be within the error allowable range.

[0085] Embodiment 5:

[0086] The embodiment of the present application provides a non-independent chassis steering mechanism design method, comprising the following steps:

[0087] According to the vehicle body motion model, the vertical arm rotation angle parameter and the steering gear transmission ratio parameter are collected, and the simulated vehicle steering wheel number of turns is calculated.

[0088]

[0089] Wherein, n is the simulated vehicle steering wheel number of turns, θ is the vertical arm rotation angle parameter, and i is the steering gear transmission ratio parameter.

[0090] In the above embodiment, the simulated vehicle steering wheel number of turns is calculated through the vertical arm rotation angle parameter and the steering gear transmission ratio parameter.

[0091] In the above embodiment, the simulated vehicle right-turn steering wheel number of turns is calculated by obtaining the right-turn limit vertical arm rotation angle parameter and the steering gear transmission ratio parameter, and the simulated vehicle left-turn steering wheel number of turns is calculated by obtaining the left-turn limit vertical rotation angle parameter and the steering gear transmission ratio parameter, to detect the consistency of the simulated vehicle steering wheel number of turns.

[0092] In the above embodiment, through the calculation and analysis of the simulated vehicle steering wheel number of turns, the difference between the right-turn limit vertical arm rotation angle and the left-turn limit vertical rotation angle should be less than 1.5°, which meets the design requirements of the vehicle body steering mechanism.

[0093] The beneficial effects of the above technology are that the simulated vehicle steering wheel number of turns is calculated by obtaining the vertical arm rotation angle parameter and the steering gear transmission ratio parameter in the model vehicle parameter, which realizes the design detection of the vehicle body steering mechanism based on the current vehicle body motion model, and further ensures the consistency of the simulated vehicle steering wheel number of turns.

[0094] Embodiment 6:

[0095] The embodiment of the present application provides a non-independent chassis steering mechanism design method, comprising the steps of: analyzing whether the vehicle body motion model meets the design requirements of the vehicle body steering mechanism according to the simulated vehicle minimum turning radius, the simulated vehicle Ackerman rotation angle, and the simulated vehicle steering wheel number of turns; when the vehicle body motion model meets the design requirements of the vehicle body steering mechanism, building a chassis steering model according to the vehicle body linear frame; comprising:

[0096] analyzing whether the vehicle body motion model meets the design requirements of the vehicle body steering mechanism, and when the vehicle body motion model does not meet the design requirements of the vehicle body steering mechanism, reconstructing the vehicle body linear frame and rebuilding the vehicle body motion model through computer-aided software;

[0097] According to the secondly constructed vehicle body motion model, the simulated vehicle minimum turning radius, the simulated vehicle Ackerman rotation angle, and the simulated vehicle steering wheel number of turns are recalculated until the vehicle body motion model meets the design requirements of the vehicle body steering mechanism, and the chassis steering model is built.

[0098] The above embodiment, according to the obtained simulation vehicle minimum turning radius, simulation vehicle Ackerman angle, simulation vehicle steering wheel number of turns, analyzes whether the vehicle body motion model meets the design requirements of the vehicle body steering mechanism, and when the vehicle body motion model does not meet the design requirements of the vehicle body steering mechanism, the vehicle body linear frame is reconstructed, the vehicle body motion model is reconstructed by using computer-aided software, the simulation vehicle minimum turning radius, the simulation vehicle Ackerman angle, and the simulation vehicle steering wheel number of turns are calculated, until the vehicle body motion model meets the design requirements of the vehicle body steering mechanism, and the chassis steering model is built according to the vehicle body linear frame.

[0099] The beneficial effects of the above technology are that when the designed vehicle body motion model does not meet the design requirements of the vehicle body steering mechanism, the vehicle body motion model is generated by reconstructing the vehicle body linear frame until the vehicle body motion model that meets the design requirements of the vehicle body steering mechanism is obtained, thereby realizing rapid adjustment and detection of the constructed vehicle body linear frame without consuming computing resources to rebuild the model, and thereby improving the construction efficiency of the chassis steering model.

[0100] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application belong to the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

Claims

1. A method of designing a non-independent chassis steering mechanism, characterized by, The method comprises the following steps: a vehicle body linear frame is built based on a vehicle body coordinate system according to a vehicle overall layout; the vehicle body linear frame is decomposed into a plurality of independent part linear models by using computer-aided software, the connection relationship between the part linear models is reserved, and a corresponding mechanical device model and a motion pair model are established based on a digital model motion module and according to the part linear models and the connection relationship; a vehicle body motion model is constructed according to the mechanical device model and the motion pair model; model vehicle parameters are collected according to the vehicle body motion model, and the minimum turning radius of a simulation vehicle, the Ackerman turning angle of the simulation vehicle and the steering wheel circle number of the simulation vehicle are calculated; whether the vehicle body motion model meets the design requirements of a vehicle body steering mechanism is analyzed according to the minimum turning radius of the simulation vehicle, the Ackerman turning angle of the simulation vehicle and the steering wheel circle number of the simulation vehicle, and when the vehicle body motion model meets the design requirements of the vehicle body steering mechanism, a chassis steering model is built according to the vehicle body linear frame; the interference of each part model in the chassis steering model is detected, and the chassis steering model is output when the chassis steering design conditions are met.

2. The non-independent chassis steering mechanism design method of claim 1, wherein, The step of building a vehicle body linear frame based on a vehicle body coordinate system according to a vehicle overall layout comprises the following steps: an overall layout of a vehicle is obtained, including the wheelbase of the vehicle, the wheel track of the front axle, the width of the vehicle frame and the wheel center height; the arrangement positions of each mechanism model of the vehicle are determined based on the vehicle body coordinate system and the overall layout of the vehicle, and a vehicle body linear frame is built under the constraints of fixed axis arrangement and length of the linkage.

3. The non-independent chassis steering mechanism design method of claim 1, wherein, The step of collecting model vehicle parameters according to the vehicle body motion model, and calculating the minimum turning radius of a simulation vehicle, the Ackerman turning angle of the simulation vehicle and the steering wheel circle number of the simulation vehicle comprises the following steps: the minimum turning radius of the simulation vehicle is calculated according to the first turning bridge to the instantaneous turning center line distance parameter, the maximum turning angle parameter of the vehicle direction and the kingpin offset distance parameter collected according to the vehicle body motion model. Wherein, R is the minimum turning radius of the simulation vehicle, L is the first turning bridge to the instantaneous turning center line distance parameter, and Ψ is the maximum turning angle parameter of the vehicle direction. C is the kingpin offset distance parameter.

4. The non-independent chassis steering mechanism design method of claim 1, wherein, The step of collecting model vehicle parameters according to the vehicle body motion model, and calculating the minimum turning radius of a simulation vehicle, the Ackerman turning angle of the simulation vehicle and the steering wheel circle number of the simulation vehicle comprises the following steps: the first bridge Ackerman angle difference value of the simulation vehicle and the second bridge Ackerman angle difference value of the simulation vehicle are calculated according to the outer front one wheel turning angle parameter, the inner front one wheel turning angle parameter, the outer front two wheel turning angle parameter, the inner front two wheel turning angle parameter, the first bridge kingpin axis to ground intersection distance parameter, the second bridge kingpin axis to ground intersection distance parameter, the one-two axle distance parameter, the two-three axle distance parameter and the three-four axle distance parameter collected according to the vehicle body motion model. Wherein, e1 is the first bridge Ackerman angle difference value of the simulation vehicle, θ1 is the outer front one wheel turning angle parameter, θ2 is the inner front one wheel turning angle parameter, K1 is the first bridge kingpin axis to ground intersection distance parameter, L1 is the one-two axle distance parameter, L2 is the two-three axle distance parameter, and L3 is the three-four axle distance parameter. Wherein, e2 is the simulation vehicle two-axle Ackerman angle difference value, θ3 is the outer front two-wheel rotation angle parameter, θ4 is the inner front two-wheel rotation angle parameter, K2 is the two-axle kingpin axis and ground intersection distance parameter.

5. The non-independent chassis steering mechanism design method of claim 1, wherein, The step of collecting model vehicle parameters according to the vehicle body motion model, calculating the simulation vehicle minimum turning radius, simulation vehicle Ackerman rotation angle and simulation vehicle steering wheel number of turns; comprising: According to the vehicle body motion model, collecting the vertical arm rotation angle parameter and the steering gear transmission ratio parameter, calculating the simulation vehicle steering wheel number of turns; Wherein, n is the simulation vehicle steering wheel number of turns, θ is the vertical arm rotation angle parameter, i is the steering gear transmission ratio parameter.

6. The non-independent chassis steering mechanism design method of claim 1, wherein, The step of analyzing whether the vehicle body motion model meets the vehicle body steering mechanism design requirements according to the simulation vehicle minimum turning radius, simulation vehicle Ackerman rotation angle, simulation vehicle steering wheel number of turns, when the vehicle body motion model meets the vehicle body steering mechanism design requirements, building a chassis steering model according to the vehicle body linear frame; comprising: Analyzing whether the vehicle body motion model meets the vehicle body steering mechanism design requirements, when the vehicle body motion model does not meet the vehicle body steering mechanism design requirements, re-building the vehicle body linear frame, and re-building the vehicle body motion model through computer aided software processing; According to the secondly built vehicle body motion model, re-calculating the simulation vehicle minimum turning radius, simulation vehicle Ackerman rotation angle and simulation vehicle steering wheel number of turns, until the vehicle body motion model meets the vehicle body steering mechanism design requirements, building a chassis steering model.

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