CN103942362A

CN103942362A - Method for designing AMT hydraulic gear shifting mechanism

Info

Publication number: CN103942362A
Application number: CN201410105586.8A
Authority: CN
Inventors: 陈慧岩; 苗成生; 刘海鸥; 丁华荣; 席军强
Original assignee: Beijing Institute of Technology BIT
Current assignee: Beijing Institute of Technology BIT
Priority date: 2014-03-20
Filing date: 2014-03-20
Publication date: 2014-07-23
Anticipated expiration: 2034-03-20
Also published as: CN103942362B

Abstract

The invention proposes a design method of an AMT hydraulic shift mechanism. The AMT hydraulic shift mechanism includes an oil cylinder, and the method includes: constructing a CO model for the oil cylinder in the AMT hydraulic shift mechanism, the CO model including a system-level objective function and three subsystem-level objective functions; through iterative calculation , determine the optimal solution of the CO model, wherein the optimal solution is the size parameter vector of the oil cylinder to be determined; according to the size parameter vector of the oil cylinder, determine the size of the AMT hydraulic shifting mechanism. The present invention obtains the optimal solution by establishing a CO model, and then selects the size parameters of the oil cylinder according to the optimal solution to complete the design of the AMT hydraulic shift mechanism.

Description

Design Method of AMT Hydraulic Shifting Mechanism

技术领域technical field

本发明涉及变速器领域，特别是，涉及AMT（Automated ManualTransmission，机械式自动变速器）液压换档机构的设计方法。The invention relates to the field of transmissions, in particular, to a design method of an AMT (Automated Manual Transmission, mechanical automatic transmission) hydraulic shift mechanism.

背景技术Background technique

AMT作为自动变速器的一种，近年来在重型车辆上得到了广泛的应用。作为实现自动换档操控的重要执行元件，AMT的换档执行机构直接操纵变速器的选位和挂档过程，影响车辆的动力性、平顺性、可靠性。As a kind of automatic transmission, AMT has been widely used in heavy vehicles in recent years. As an important actuator to realize automatic shift control, the shift actuator of AMT directly controls the selection and shifting process of the transmission, which affects the dynamic performance, ride comfort and reliability of the vehicle.

现有的换档执行机构基本分为液压式、气动式和电动式。在重型车辆上，液压执行机构应用最为广泛。在对液压换档机构的设计中，如何确定选位油缸尺寸和换档油缸尺寸，是液压换档机构设计的核心。The existing shift actuators are basically divided into hydraulic, pneumatic and electric. On heavy vehicles, hydraulic actuators are most widely used. In the design of the hydraulic shifting mechanism, how to determine the size of the position selection cylinder and the size of the shifting cylinder is the core of the design of the hydraulic shifting mechanism.

现有的液压换档机构的设计方法，可归结为根据先验知识和单一约束条件，参照机械工程手册初选尺寸参数，然后再进行其它约束条件的验证。如果不满足要求，再重新选择尺寸参数，直到找到满足所有约束条件的尺寸参数。该现有方法至少存在以下三点缺陷：（1）得到的结果只是可行解，并非最优解；（2）需要多次选择参数才能得到需要的解，计算量大，当约束条件增多时会大大加重计算负担，且具有盲目性；（3）设计和加工的产品体积大，成本高，效率低。The existing design method of the hydraulic shifting mechanism can be attributed to the preliminary selection of the size parameters according to the prior knowledge and a single constraint condition, referring to the mechanical engineering manual, and then verifying other constraints. If the requirements are not met, reselect the size parameters until a size parameter that satisfies all constraints is found. This existing method has at least the following three defects: (1) The result obtained is only a feasible solution, not the optimal solution; (2) It needs to select parameters multiple times to obtain the required solution, which requires a large amount of calculation. It greatly increases the calculation burden and is blind; (3) The products designed and processed are large in size, high in cost and low in efficiency.

发明内容Contents of the invention

为了克服以上缺陷，本发明提出了一种AMT液压换档机构的设计方法，能够解决现有方法中所得结果为非最优解的问题。In order to overcome the above defects, the present invention proposes a design method of an AMT hydraulic shift mechanism, which can solve the problem that the result obtained in the existing method is a non-optimal solution.

一方面，一种机械式自动变速器AMT液压换档机构的设计方法，所述AMT液压换档机构包括油缸，所述方法包括：为所述AMT液压换档机构中的油缸构建协同优化CO模型，所述CO模型包括系统级目标函数和至少一个子系统级目标函数；通过迭代计算，确定所述CO模型的最优解，其中所述最优解为所述油缸的所需确定的尺寸参数向量；依据所述油缸的尺寸参数向量，确定所述AMT液压换档机构的尺寸。On the one hand, a method for designing an AMT hydraulic shift mechanism of a mechanical automatic transmission, the AMT hydraulic shift mechanism includes an oil cylinder, and the method includes: constructing a collaborative optimization CO model for the oil cylinder in the AMT hydraulic shift mechanism, The CO model includes a system-level objective function and at least one subsystem-level objective function; through iterative calculations, the optimal solution of the CO model is determined, wherein the optimal solution is the required size parameter vector of the oil cylinder ; Determine the size of the AMT hydraulic shift mechanism according to the size parameter vector of the oil cylinder.

进一步地，所述为所述AMT液压换档机构中的油缸构建CO模型，包括：构建所述油缸的系统目标函数；构建所述油缸的子系统目标函数，其中所述子系统目标函数为所述系统目标函数的一致性约束条件。Further, the constructing the CO model for the cylinder in the AMT hydraulic shift mechanism includes: constructing the system objective function of the cylinder; constructing the subsystem objective function of the cylinder, wherein the subsystem objective function is the Consistency constraints of the system objective function.

进一步地，所述系统目标函数为所述子系统目标函数为其中，l为所述油缸的长度，x_i为子系统设计变量：x₁={d₁,d₂,d₃,d₄},x₂={d₁,d₂,d₃,d₄},x₃={d₁,d₂,d₄,h}，z_j ^*为系统层的优化结果Z中元素，x_ij为第i个子系统的第j个设计变量，d₁为活塞杆的输出端直径、d₂为油缸的B腔的内径、d₃为活塞的内0径、d₄为油缸的A腔的内径或活塞的外径、h为油缸的A腔的缸壁厚度。Further, the system objective function is The objective function of the subsystem is Wherein, l is the length of the oil cylinder, x _i is the subsystem design variable: x ₁ ={d ₁ ,d ₂ ,d ₃ ,d ₄ }, x ₂ ={d ₁ ,d ₂ ,d ₃ ,d ₄ }, x ₃ ={d ₁ ,d ₂ ,d ₄ ,h}, z _j ^* is the element in Z of the optimization result of the system layer, x _ij is the jth design variable of the i-th subsystem, and d ₁ is the piston rod The diameter of the output end, d ₂ is the inner diameter of the B chamber of the oil cylinder, d ₃ is the inner diameter of the piston, d ₄ is the inner diameter of the A chamber of the oil cylinder or the outer diameter of the piston, h is the cylinder wall thickness of the A chamber of the oil cylinder.

进一步地，通过迭代计算，确定所述CO模型的最优解，包括：系统级向三个子系统级分配设计向量期望值Z，所述三个子系统级中的各个子系统在满足其自身约束条件的前提下，分别求取其设计变量与系统级提供给该子系统的目标值之间的差异最小值，并将优化结果X_i（i=1，2，3）返回给系统级；系统级根据子系统级返回的设计向量X_i返构造子系统间一致性等式约束，在其约束条件下，求取系统目标函数的最小值，并将优化结果Z’再次传给子系统级；经过系统级优化和子系统级优化之间的多次迭代，最终确定所述CO模型的最优解。Further, through iterative calculation, the optimal solution of the CO model is determined, including: the system level assigns the design vector expectation value Z to the three subsystem levels, and each subsystem in the three subsystem levels satisfies its own constraints Under the premise, the minimum value of the difference between the design variables and the target value provided by the system level to the subsystem is calculated respectively, and the optimization result Xi ( _i =1, 2, 3) is returned to the system level; the system level is based on The design vector _Xi returned by the subsystem level is returned to construct the consistency equality constraints between subsystems, and under the constraint conditions, the minimum value of the system objective function is obtained, and the optimization result Z' is sent to the subsystem level again; through the system Multiple iterations between level optimization and subsystem level optimization finally determine the optimal solution of the CO model.

进一步的，所述确定所述CO模型的最优解，包括：依据一致性约0束条件，确定所述油缸的系统目标函数的最优解；依据载荷约束条件、时间约束条件和强度约束条件，确定所述油缸的子系统目标函数的最优解。Further, the determining the optimal solution of the CO model includes: determining the optimal solution of the system objective function of the oil cylinder according to the consistency constraint condition; determining the optimal solution according to the load constraint condition, time constraint condition and strength constraint condition , to determine the optimal solution of the cylinder subsystem objective function.

进一步地，所述依据一致性约束条件，确定所述油缸的系统目标函数的最优解，包括：Further, the determining the optimal solution of the system objective function of the oil cylinder according to the consistency constraint condition includes:

$min min F f ((z z)) = = π π {((\frac{{d d}_{44}}{22} + + h h))}^{22} ((l l + + 0.006 0.006))$

$s the s . . t t . . \{\begin{matrix} {J J}_{11} = = {Σ Σ}_{i i = = 11}^{44} {(({d d}_{i i} - - {d d}_{11 i i}^{* *}))}^{22} \leq \leq δ δ \\ {J J}_{22} = = {Σ Σ}_{i i = = 11}^{44} {(({d d}_{i i} - - {d d}_{22 i i}^{* *}))}^{22} \leq \leq δ δ \\ {J J}_{33} = = {(({d d}_{11} - - {d d}_{3131}^{* *}))}^{22} + + {(({d d}_{22} - - {d d}_{3232}^{* *}))}^{22} + + {(({d d}_{44} - - {d d}_{3434}^{* *}))}^{22} {+ +}^{{((h h - - {h h}_{33}^{* *}))}^{22} \leq \leq δ δ} \end{matrix}$

其中，F(z)为需要优化的系统目标函数；d_i为系统层的设计变量：d₁为活塞杆的输出端直径、d₂为油缸的B腔的内径、d₃为活塞的内径、d₄为油缸的A腔的内径或活塞的外径、h为油缸的A腔的缸壁厚度，l为所述油缸的长度，J₁是第一子系统级的一致性约束，J₂是第二子系统级的一致性约束，J₃是第三子系统级的一致性约束，d_1i ^*为第一子系统级的优化结果X₁中元素，d_2i ^*为第二子系统级的优化结果X₂中元素，d₃₁ ^*、d₃₂ ^*、d₃₄ ^*、h₃ ^*为第三子系统级的优化结果X₃中元素。Among them, F(z) is the system objective function to be optimized; d _i is the design variable of the system layer: d ₁ is the diameter of the output end of the piston rod, d ₂ is the inner diameter of the B cavity of the oil cylinder, d ₃ is the inner diameter of the piston, d ₄ is the inner diameter of the A chamber of the oil cylinder or the outer diameter of the piston, h is the thickness of the cylinder wall of the A chamber of the oil cylinder, l is the length of the oil cylinder, J ₁ is the consistency constraint of the first subsystem level, and J ₂ is The consistency constraint at the second subsystem level, J ₃ is the consistency constraint at the third subsystem level, d _1i ^* is the element in X ₁ of the optimization result at the first subsystem level, and d _2i ^* is the element at the second subsystem level The elements in the optimization result X ₂ , d ₃₁ ^* , d ₃₂ ^* , d ₃₄ ^* , h ₃ ^* are the elements in the optimization result X ₃ of the third subsystem level.

可选地，所述依据载荷约束条件、时间约束条件和强度约束条件，确定所述油缸的子系统目标函数的最优解，包括：Optionally, the determining the optimal solution of the objective function of the subsystem of the oil cylinder according to the load constraint condition, time constraint condition and strength constraint condition includes:

依据载荷约束条件，确定所述油缸的第一子系统目标函数的最优解；Determine the optimal solution of the objective function of the first subsystem of the oil cylinder according to the load constraint condition;

依据时间约束条件，确定所述油缸的第二子系统目标函数的最优解；Determine the optimal solution of the objective function of the second subsystem of the oil cylinder according to the time constraints;

依据强度约束条件，确定所述油缸的第三子系统目标函数的最优解。According to the strength constraint condition, the optimal solution of the objective function of the third subsystem of the oil cylinder is determined.

可选地，所述依据载荷约束条件，确定所述油缸的第一子系统目标函数的最优解，包括：Optionally, the determining the optimal solution of the objective function of the first subsystem of the oil cylinder according to the load constraint condition includes:

$min min {J J}_{11} = = {Σ Σ}_{i i = = 11}^{44} {(({d d}_{11 i i} - - {d d}_{i i}^{* *}))}^{22},, i i = = 1,2,3,4 1,2,3,4$

其中，F_m为油缸各过程输出作用力，m=1,2,3,4，F_m的上标1，2分别表示前后两个过程；S_n为对应过程有效工作面积，n=1,2,3；P为油源主压力，由系统油源决定，不属于AMT液压换档机构本身可控的参数，不在优化范围内，输出油压为一变化值P∈[4,4.5]Mpa，本具体实施例中选油压最小值计算；P₀为油箱油压取为0；F_max为最大换档力1700N。Among them, F _m is the output force of each process of the oil cylinder, m=1, 2, 3, 4, the superscripts 1 and 2 of F _m represent the two processes before and after respectively; S _n is the effective working area of the corresponding process, n=1, 2,3; P is the main pressure of the oil source, which is determined by the oil source of the system. It is not a controllable parameter of the AMT hydraulic shift mechanism itself, and it is not within the optimization range. The output oil pressure is a variable value P∈[4,4.5]Mpa , in this specific embodiment, the minimum value of oil pressure is selected for calculation; P ₀ is taken as 0 for the fuel tank oil pressure; F _max is the maximum shift force of 1700N.

可选地，所述依据时间约束条件，确定所述油缸的第二子系统目标函数的最优解，包括：Optionally, the determining the optimal solution of the objective function of the second subsystem of the oil cylinder according to the time constraints includes:

$\{\begin{matrix} min min {J J}_{22} = = {Σ Σ}_{i i = = 11}^{44} {(({d d}_{22 i i} - - {d d}_{i i}^{* *}))}^{22},, i i = = 1,2,3,4 1,2,3,4 \\ s the s . . t t . . {t t}_{11} = = {t t}_{11}^{11} + + {t t}_{11}^{22} = = 0.8 0.8 {S S}_{11} {l l}_{c c} / / {Q Q}_{11 a a}^{11} + + 0.2 0.2 {S S}_{11} {l l}_{c c} / / {Q Q}_{11 a a}^{22} \\ {t t}_{22} = = {t t}_{22}^{11} + + {t t}_{22}^{22} = = 0.7 0.7 {S S}_{22} {l l}_{c c} / / {Q Q}_{22 b b}^{11} + + 0.3 0.3 {S S}_{22} {l l}_{c c} / / {Q Q}_{22 b b}^{22} \\ {t t}_{33} = = {t t}_{33}^{11} + + {t t}_{33}^{22} = = 0.8 0.8 {S S}_{22} {l l}_{c c} / / {Q Q}_{22 b b}^{11} + + 0.2 0.2 {S S}_{22} {l l}_{c c} / / {Q Q}_{33 b b}^{22} \\ {t t}_{44} = = {t t}_{44}^{11} + + {t t}_{44}^{22} = = 0.7 0.7 {S S}_{33} {l l}_{c c} / / {Q Q}_{44 a a}^{11} + + 0.3 0.3 {S S}_{33} {l l}_{c c} / / {Q Q}_{44 a a}^{22} \end{matrix}$

其中，P_ɑ、P_b分别表示液压缸A、B腔的油压，上标1、2分别表示前后两个工作阶段；t_j表示四个换档行程的换档时间。Among them, P _ɑ and P _b represent the oil pressures of hydraulic cylinders A and B respectively, superscripts 1 and 2 represent the two working stages before and after; t _j represents the shift time of the four shift strokes.

可选地，所述依据强度约束条件，确定所述油缸的第三子系统目标函数的最优解，包括：Optionally, the determining the optimal solution of the objective function of the third subsystem of the oil cylinder according to the strength constraint condition includes:

$\{\begin{matrix} min min {J J}_{33} = = {(({d d}_{3131} - - {d d}_{11}^{* *}))}^{22} {+ +}^{{(({d d}_{3232} - - {d d}_{22}^{* *}))}^{22} + + {(({d d}_{3434} - - {d d}_{44}^{* *}))}^{22}} \\ + + (({h h}_{33} - - {h h}^{* *})) \\ s the s . . t t . . δ δ = = \frac{{P P}_{y the y} D D.}{22 [[σ σ]]} = = \frac{1.5 1.5 P P \times \times {22 d d}_{44}}{22 \times \times (({σ σ}_{b b} / / {n no}_{11}))} \\ {σ σ}_{n no} = = \sqrt{{((\frac{KF KF}{π π {d d}_{00}^{22} / / 44}))}^{22} + + 33 {((\frac{{K K}_{11} KF KF {d d}_{11}}{0.2 0.2 {d d}_{00}^{33}}))}^{22}} \\ h h > > δ δ \\ {σ σ}_{n no} \leq \leq [[σ σ]] \end{matrix}$

其中，δ为缸壁许用厚度；F表示活塞杆的最大拉应力；d₀为活塞杆的端部螺纹内径，d₀=d₁-1.0825e，e为螺距；σ_n表示活塞杆的危险截面处的合成应力；[σ]为许用应力，[σ]=σ_s/n₂，σ_s为螺纹屈服点，n₂为安全系数。Among them, δ is the allowable thickness of the cylinder wall; F represents the maximum tensile stress of the piston rod; d ₀ is the inner diameter of the end thread of the piston rod, d ₀ =d ₁ -1.0825e, e is the pitch; σ _n represents the risk of the piston rod The resultant stress at the section; [σ] is the allowable stress, [σ]=σ _s /n ₂ , σ _s is the thread yield point, and n ₂ is the safety factor.

本发明通过建立CO（Collaborative Optimization，协同优化）模型得到最优解，进而依据最优解选择油缸尺寸参数，完成AMT液压换档机构的设计。The present invention obtains the optimal solution by establishing a CO (Collaborative Optimization) model, and then selects the size parameters of the oil cylinder according to the optimal solution to complete the design of the AMT hydraulic shift mechanism.

此外，根据本发明的方法不具有盲目性，可以提高计算效率，有助于提高油缸的工作效率，减小体积和成本。In addition, the method according to the present invention is not blind, can improve calculation efficiency, contribute to improving the working efficiency of the oil cylinder, and reduce volume and cost.

附图说明Description of drawings

为了更清楚地说明本发明实施例的技术方案，下面将对本发明实施例中所需要使用的附图作简单地介绍，显而易见地，下面所描述的附图仅仅是本发明的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the accompanying drawings required in the embodiments of the present invention. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For Those of ordinary skill in the art can also obtain other drawings based on these drawings without making creative efforts.

图1示出了重型车辆九档AMT的档位布置。Figure 1 shows the gear arrangement of a nine-speed AMT for a heavy-duty vehicle.

图2为AMT的结构示意图。Fig. 2 is a schematic diagram of the structure of AMT.

图3为AMT的液压换档机构的结构示意图。FIG. 3 is a schematic structural diagram of the hydraulic shift mechanism of the AMT.

图4为AMT的换档油缸的结构简图。FIG. 4 is a schematic structural diagram of the shift cylinder of the AMT.

图5为换档油缸的CO模型。Figure 5 is the CO model of the shift cylinder.

具体实施方式Detailed ways

下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例是本发明的一部分实施例，而不是全部实施例。基于本发明中的实施例，本领域普通技术人员在没有做出创造性劳动的前提下所获得的所有其他实施例，都应属于本发明保护的范围。The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

本发明的AMT液压换档机构的设计方法，包括以下三个步骤。The design method of the AMT hydraulic shift mechanism of the present invention includes the following three steps.

步骤一，为AMT液压换档机构中的油缸（例如，换挡油缸和/或选位油缸）构建CO模型，该CO模型可以包括系统级目标函数和三个子系统级目标函数。Step 1: Construct a CO model for the cylinders in the AMT hydraulic shift mechanism (for example, shift cylinders and/or position selection cylinders). The CO model may include a system-level objective function and three subsystem-level objective functions.

也就是，构建所述油缸的系统目标函数；构建所述油缸的子系统目标函数，其中所述子系统目标函数为所述系统目标函数的一致性约束条件。That is, constructing the system objective function of the oil cylinder; constructing the subsystem objective function of the oil cylinder, wherein the subsystem objective function is a consistency constraint condition of the system objective function.

步骤二，通过迭代计算，确定所述CO模型的最优解，其中所述最优解为所述油缸的所需确定的尺寸参数向量。Step 2, through iterative calculation, determine the optimal solution of the CO model, wherein the optimal solution is the required size parameter vector of the oil cylinder.

也就是，系统级向三个子系统级分配设计向量期望值Z，所述三个子系统级中的各个子系统在满足其自身约束条件的前提下，分别求取其设计变量与系统级提供给该子系统的目标值之间的差异最小值，并将优化结果X_i（i=1，2，3）返回给系统级，其中；系统级根据所述三个子系统级返回的优化结果X_i构造子系统间一致性约束，在其约束条件下，求取系统目标函数的最小值，并将优化结果Z’再次传给子系统级作为新的设计向量期望值；经过系统级优化和子系统级优化之间的多次迭代，最终确定所述CO模型的最优解。That is, the system level assigns the design vector expected value Z to the three subsystem levels, and each subsystem in the three subsystem levels, under the premise of satisfying its own constraint conditions, respectively obtains its design variables and the system level provides the subsystem The difference between the target values of the system is the minimum value, and the optimization result X _i (i=1, 2, 3) is returned to the system level, wherein; the system level constructs the child according to the optimization result _Xi returned by the three subsystem levels Consistency constraints between systems, under the constraints, find the minimum value of the system objective function, and pass the optimization result Z' to the subsystem level again as the expected value of the new design vector; after the optimization between the system level and the subsystem level Multiple iterations to finally determine the optimal solution of the CO model.

其中，依据一致性约束条件，确定所述油缸的系统目标函数的最优解；依据载荷约束条件、时间约束条件和强度约束条件，确定所述油缸的子系统目标函数的最优解。Wherein, the optimal solution of the system objective function of the oil cylinder is determined according to the consistency constraint condition; the optimal solution of the subsystem objective function of the oil cylinder is determined according to the load constraint condition, time constraint condition and strength constraint condition.

步骤三，依据所述油缸的尺寸参数向量，确定所述AMT液压换档机构的尺寸。Step 3: Determine the size of the AMT hydraulic shift mechanism according to the size parameter vector of the oil cylinder.

在一个具体实施例中，以重型车辆九档机械式自动变速器5S-111GP（爬档C、1～8档和倒档R）为例，其档位布置如图1所示。该AMT由主箱和副箱组成，如图2所示。主箱为三轴式定轴齿轮变速箱，实现1/5、2/6、3/7、4/8、倒档和爬档六个档位的切换。副箱为行星齿轮变速箱，实现高低档两个档位的切换。在主箱中实现各个档位的切换是通过换档轴实现的，即操纵换档轴旋转可实现挂（摘）档，操纵换档轴轴向运动可实现选位。通过两个电磁气阀的控制，在副箱中实现高低档的切换。由于AMT结构简单，在此不作详细介绍。In a specific embodiment, taking a heavy-duty vehicle nine-speed mechanical automatic transmission 5S-111GP (climbing gear C, 1st to 8th gear and reverse gear R) as an example, its gear arrangement is shown in FIG. 1 . The AMT consists of a main box and an auxiliary box, as shown in Figure 2. The main box is a three-shaft fixed-shaft gear transmission, which realizes the switching of six gears: 1/5, 2/6, 3/7, 4/8, reverse gear and climbing gear. The auxiliary box is a planetary gear box, which realizes the switch between high and low gears. The switching of each gear position in the main box is realized through the shift shaft, that is, the rotation of the shift shaft can realize the shifting (removal) of gears, and the axial movement of the shift shaft can realize position selection. Through the control of two electromagnetic valves, the switch between high and low gears is realized in the auxiliary box. Since the structure of the AMT is simple, it will not be introduced in detail here.

AMT的液压换档机构为主箱换档机构，主要包括选位油缸1、换档油缸2、固定箱体3和相应的连接件，如图3所示。选位油缸1和换档油缸2分别控制AMT主箱的换档轴的轴向和旋转运动，实现选位和换档操作。其中，选位油缸1的活塞杆直接与AMT主箱的换档轴4相连，控制其轴向运动，实现选位操作；换档油缸2通过摆臂与该换档轴4相连，经摆臂转换，将活塞杆的直线运动转化为AMT主箱的换档轴4的旋转运动，实现换档操作。The hydraulic shift mechanism of AMT is the main box shift mechanism, which mainly includes position selection cylinder 1, shift cylinder 2, fixed box 3 and corresponding connecting parts, as shown in Figure 3. Position selection cylinder 1 and gear shift cylinder 2 respectively control the axial and rotational movement of the shift shaft of the AMT main box to realize position selection and gear shifting operations. Among them, the piston rod of the position selection cylinder 1 is directly connected with the shift shaft 4 of the AMT main box, and its axial movement is controlled to realize the position selection operation; the shift cylinder 2 is connected with the shift shaft 4 through a swing arm, and Conversion, converting the linear motion of the piston rod into the rotational motion of the shift shaft 4 of the AMT main box to realize the shift operation.

这里，选位油缸1和换档油缸2均为三位油缸，由两组二位三通高速开关电磁阀（例如，一组为选位电磁阀HSV₁和HSV₂，另一组为换档电磁阀HSV₃和HSV₄）控制油缸两端油腔的油液充放，实现活塞杆的三个位置的运动，各档位电磁阀动作逻辑如表1所示，其中N为空档。Here, position selection cylinder 1 and gear shift cylinder 2 are three-position oil cylinders, with two sets of two-position three-way high-speed switching solenoid valves (for example, one set is position selection solenoid valves HSV ₁ and HSV ₂ , and the other set is shift Solenoid valves HSV ₃ and HSV ₄ ) control the oil filling and discharging of the oil chamber at both ends of the cylinder to realize the movement of the three positions of the piston rod. The action logic of the solenoid valves in each gear is shown in Table 1, where N is neutral.

表1电磁阀动作逻辑表Table 1 Solenoid valve action logic table

AMT液压换档机构通过换档轴4直接安装于AMT主箱的箱体上，因而属于AMT的外部附加部件。由于车辆允许安装空间有限，因此要求该AMT液压换档机构的外形尺寸尽量小，以增强其实用性以及与动力系统的匹配性。The AMT hydraulic shift mechanism is directly installed on the case body of the AMT main box through the shift shaft 4, and thus belongs to the external additional parts of the AMT. Due to the limited installation space allowed by the vehicle, the AMT hydraulic shift mechanism is required to be as small as possible in order to enhance its practicability and compatibility with the power system.

AMT液压换档机构最主要的组成部分是选位油缸1和换档油缸2。选位油缸1和换档油缸2不仅决定了AMT液压换档机构的体积大小，也直接操控换档过程，影响AMT液压换档机构的平顺性和动力性，且选位油缸1和换档油缸2的使用寿命将决定AMT液压换档机构的可靠性。The most important components of the AMT hydraulic shift mechanism are the position selection cylinder 1 and the shift cylinder 2 . Position selection cylinder 1 and shift cylinder 2 not only determine the size of the AMT hydraulic shift mechanism, but also directly control the shift process, affecting the smoothness and power of the AMT hydraulic shift mechanism, and the position selection cylinder 1 and shift cylinder 2 The service life will determine the reliability of the AMT hydraulic shifting mechanism.

由于选位油缸1和换档油缸2的结构形式完全相同，只是尺寸参数有所不同。为了简化说明，下面将仅以换档油缸2为例详细说明如何通过本发明的方法来确定结构尺寸。Because the structural forms of the position selection oil cylinder 1 and the shift oil cylinder 2 are exactly the same, only the dimension parameters are different. In order to simplify the description, the following will only take the shift cylinder 2 as an example to describe in detail how to determine the structural size through the method of the present invention.

图4为换档油缸2的结构简图。如图所示，换档油缸2主要由活塞杆21（端部加工螺纹）、活塞22、缸体23、缸盖24组成。换档油缸2包括A腔和B腔两个腔，高速开关阀HSV3、HSV4分别控制A、B腔的进出油。FIG. 4 is a schematic structural diagram of the shift cylinder 2 . As shown in the figure, the gear shift cylinder 2 is mainly composed of a piston rod 21 (end processing thread), a piston 22, a cylinder body 23, and a cylinder head 24. The shift oil cylinder 2 includes two chambers, A chamber and B chamber, and the high-speed switching valves HSV3 and HSV4 respectively control the oil in and out of the A and B chambers.

换档油缸2执行以下四个工作过程：Shift cylinder 2 performs the following four work processes:

过程①——中位至右位，即从空档N挂至R/1/3/5/7档的过程，即挂档过程；Process ①—from the middle position to the right position, that is, the process of shifting from neutral gear N to R/1/3/5/7 gear, that is, the gear shifting process;

过程②——右位至中位，即从R/1/3/5/7档摘至空档N的过程，即摘档过程；Process ②—from the right position to the middle position, that is, the process of selecting from R/1/3/5/7 to neutral position N, that is, the process of removing gears;

过程③——中位至左位，即从空档N挂至C/2/4/6/8档的过程，即挂档过程；Process ③—from the middle position to the left position, that is, the process of shifting from the neutral gear N to the C/2/4/6/8 gear, that is, the gear shifting process;

过程④——左位至中位，即从C/2/4/6/8档摘至空档N的过程，即摘档过程。Process ④——from the left position to the middle position, that is, the process from the C/2/4/6/8 gear to the neutral gear N, that is, the gear removal process.

以上，左位、右位和中位均是指活塞杆的运动位置，分别为左极限位置、右极限位置及中间位置。Above, the left position, the right position and the middle position all refer to the movement position of the piston rod, which are respectively the left limit position, the right limit position and the middle position.

根据以上换档油缸2的工作原理以及同步器的工作原理，在各过程中电磁阀HSV₃、HSV₄的动作次序如表2所示：According to the above working principle of the shift cylinder 2 and the working principle of the synchronizer, the action sequence of the solenoid valves HSV ₃ and HSV ₄ in each process is shown in Table 2:

表2各过程电磁阀动作逻辑Table 2 Action logic of solenoid valves in each process

在换档油缸2的设计过程中，最重要的是尺寸参数的选取，即活塞杆21的输出端直径d₁、换档油缸B腔的内径d₂、活塞22的内径d₃、换档油缸A腔的内径（也即活塞22的外径）d₄和换档油缸A腔的缸壁厚度h。使换档油缸2在满足作用力、动作时间和强度的基础上，体积尽可能减小，以满足AMT液压换档机构在换档力、换档时间与可靠性等方面的要求。下表3提供了换档油缸2的其他已知参数。In the design process of the shift cylinder 2, the most important thing is the selection of the size parameters, that is, the diameter d ₁ of the output end of the piston rod 21, the inner diameter d ₂ of the chamber B of the shift cylinder, the inner diameter d 3 of the piston 22, and the diameter d ₃ of the shift cylinder. The inner diameter of the chamber A (that is, the outer diameter of the piston 22) _d4 and the cylinder wall thickness h of the chamber A of the gear shift cylinder. The volume of the shift cylinder 2 is reduced as much as possible on the basis of satisfying the force, action time and strength, so as to meet the requirements of the AMT hydraulic shift mechanism in terms of shift force, shift time and reliability. Table 3 below provides other known parameters for shift cylinder 2 .

表3油缸设计已知参数Table 3 Known parameters of oil cylinder design

以下将具体说明如何通过建立CO模型，确定AMT液压换档机构的尺寸。The following will specifically explain how to determine the size of the AMT hydraulic shift mechanism by establishing a CO model.

1、建立AMT液压换档机构的CO模型1. Establish CO model of AMT hydraulic shift mechanism

作为耦合系统的多级优化方法，CO模型具有系统级和子系统级两级优化结构。顶层的系统级优化器以系统目标函数为优化目标，约束条件为各子系统间一致性约束，从而协调各子系统的优化结果；子系统级优化器采用系统级设计变量期望值与该子系统优化解的差异作为优化目标函数，约束条件为与本子系统相关的约束。As a multi-level optimization method for coupled systems, the CO model has a two-level optimization structure of system level and subsystem level. The top-level system-level optimizer takes the system objective function as the optimization goal, and the constraint conditions are consistency constraints among subsystems, so as to coordinate the optimization results of each subsystem; the subsystem-level optimizer uses the system-level design variable expectation and the subsystem optimization The difference of the solution is used as the optimization objective function, and the constraints are the constraints related to this subsystem.

以下将仍以换档油缸2为例，说明如何建立CO模型，并实现AMT液压换档机构的设计。鉴于选位油缸1与换档油缸2的结构形式完全相同，只是尺寸参数有所不同，在此不再赘述。The following will still take the shift cylinder 2 as an example to illustrate how to establish the CO model and realize the design of the AMT hydraulic shift mechanism. In view of the fact that the position selection cylinder 1 and the gear shift cylinder 2 have the same structural form, only the size parameters are different, so they will not be repeated here.

1.1建立换档油缸2的CO模型1.1 Establish CO model of shift cylinder 2

以换档油缸2为例进行说明，分析CO模型在AMT液压换档机构的设计中的应用，图5示出了换档油缸2的CO模型。Taking the shift cylinder 2 as an example, the application of the CO model in the design of the AMT hydraulic shift mechanism is analyzed. Figure 5 shows the CO model of the shift cylinder 2.

以换档油缸2的体积为优化设计目标；设计要求为油缸满足力、时间、许用强度等约束条件；设计变量为液压缸的内径和壁厚，设为向量x={d₁,d₂,d₃,d₄,h}；各油腔的工作面积如下所示。Taking the volume of the shift cylinder 2 as the optimization design goal; the design requirements are that the cylinder meets the constraint conditions such as force, time, and allowable strength; the design variables are the inner diameter and wall thickness of the hydraulic cylinder, which is set as the vector x={d ₁ ,d ₂ ,d ₃ ,d ₄ ,h}; the working area of each oil chamber is as follows.

表示活塞22的内径d₃所对应的的面积，当活塞杆21由中位向右位移动（或由右位向中位移动）时，A腔内油液对活塞杆21的作用面积； Indicates the area corresponding to the inner diameter _d3 of the piston 22, when the piston rod 21 moves from the neutral position to the right position (or from the right position to the neutral position), the area of action of the oil in the chamber A on the piston rod 21;

表示当活塞杆21由中位向右位移动（或由右位向中位移动）时，B腔内油液对活塞杆21的作用面积； Indicates the action area of the oil in chamber B on the piston rod 21 when the piston rod 21 moves from the middle position to the right position (or from the right position to the middle position);

表示活塞22的外径d₄所对应的面积，当活塞杆21由中位向左位移动（或由左位向中位移动）时，A腔内油液对活塞杆21的作用面积。 Indicates the area corresponding to the outer diameter _d4 of the piston 22, when the piston rod 21 moves from the middle position to the left position (or from the left position to the middle position), the area of action of the oil in the chamber A on the piston rod 21.

由此建立换档油缸2的优化CO模型，如图5所示：系统层为经济性模型，以换档油缸2的体积作为优化目标；子系统层分别为力学模型、动力学模型和可靠性模型，分别代表载荷、时间与许用强度的约束条件。Thus, the optimized CO model of the shift cylinder 2 is established, as shown in Figure 5: the system layer is an economic model, and the volume of the shift cylinder 2 is used as the optimization target; the subsystem layers are the mechanical model, dynamics model and reliability model respectively. model, representing the constraints of load, time, and allowable strength, respectively.

系统的目标函数，即换档油缸2的简化模型的体积F(z)为：The objective function of the system, that is, the volume F(z) of the simplified model of the shift cylinder 2 is:

$F f ((z z)) = = π π {((\frac{{d d}_{44}}{22} + + h h))}^{22} ((l l + + 0.006 0.006)) - - - - - - ((11))$

约束条件（即系统级一致性约束）J_i为：Constraints (that is, system-level consistency constraints) J _i are:

${J J}_{i i} ((z z)) = = {Σ Σ}_{j j = = 11}^{55} {(({z z}_{j j} - - {x x}_{ij ij}^{* *}))}^{22} = = 00 - - - - - - ((22))$

这里，l为液压换档油缸2的长度，由换档行程lx和电磁阀（HSV₃和HSV₄）的间距决定，即l＝lx+l₁+2l₀。约束条件Ji也是第i（其中i=1,2,3）个子系统的目标函数；z_j，x_ij ^*分别是系统级和子系统级的设计变量向量。Here, l is the length of the hydraulic shift cylinder 2, which is determined by the distance between the shift stroke lx and the solenoid valves (HSV ₃ and HSV ₄ ), that is, l=lx+l ₁ +2l ₀ . Constraints Ji are also the objective function of the i-th (where i=1,2,3) subsystem; z _j , x _ij ^* are design variable vectors at the system level and subsystem level, respectively.

子系统的目标函数为：The objective function of the subsystem is:

${J J}_{i i} (({x x}_{i i})) = = {Σ Σ}_{j j = = 11}^{44} {(({x x}_{ij ij} - - {z z}_{j j}^{* *}))}^{22} - - - - - - ((33))$

子系统需满足的约束条件为：The constraints that the subsystem needs to satisfy are:

c_i(x_i)≤0 （4）c _i (x _i )≤0 (4)

这里，x_i为子系统设计变量：x₁={d₁,d₂,d₃,d₄},x₂={d₁,d₂,d₃,d₄},x₃={d₁,d₂,d₄,h}，z_j ^*为系统层的优化结果中元素，x_ij为第i个子系统的第j个设计变量，c₁，c₂，c₃分别对应载荷、时间、强度要求下的相关约束条件。首先，系统级向子系统级分配设计向量期望值Z，子系统i在满足其自身约束条件c_i(x_i)≤0的前提下，求取其设计变量与系统级提供给该子系统的目标值之间的差异最小值，并将优化结果X_i返回给系统级。系统级根据子系统级返回的设计向量X_i构造子系统间一致性等式约束J_i(z)，在其约束条件下，求取系统目标函数F(z)的最小值，并将优化结果Z’再次传给子系统级。经过系统级优化和子系统级优化之间的多次迭代，最终得到一个最优的系统设计方案。Here, _xi is the subsystem design variable: x ₁ ={d ₁ ,d ₂ ,d ₃ ,d ₄ }, x ₂ ={d ₁ ,d ₂ ,d ₃ ,d ₄ },x ₃ ={d ₁ ,d ₂ ,d ₄ ,h}, z _j ^* is the element in the optimization result of the system layer, x _ij is the jth design variable of the i-th subsystem, c ₁ , c ₂ , c ₃ correspond to load, time, Relevant constraints under strength requirements. First, the system level assigns the design vector expectation value Z to the subsystem level, and subsystem i obtains its design variables and the target provided to the subsystem by the system level under the premise of satisfying its own constraint condition c _i (xi ₎ ≤0 The difference between the values is the minimum value, and the optimization result _Xi is returned to the system level. The system level constructs the consistency equality constraints J _i (z) between subsystems according to the design vector _Xi returned by the subsystem level. Z' is again passed to the subsystem level. After several iterations between system-level optimization and subsystem-level optimization, an optimal system design scheme is finally obtained.

以上，X为各子系统每步迭代计算后的优化结果。子系统设计变量x={d₁,d₂,d₃,d₄,h}经过子系统的优化计算得到的优化结果，即子系统一组单步最优值{d₁,d₂,d₃,d₄,h}记为X。Above, X is the optimization result of each subsystem after each step of iterative calculation. The subsystem design variable x={d ₁ ,d ₂ ,d ₃ ,d ₄ ,h} is the optimization result obtained through the optimization calculation of the subsystem, that is, a set of single-step optimal values of the subsystem {d ₁ ,d ₂ ,d ₃ ,d ₄ ,h} is denoted as X.

以上，Z为系统层每步迭代计算后的优化结果。系统层设计变量z={d₁,d₂,d₃,d₄,h}经过系统层的优化计算得到的优化结果，即系统层一组单步最优值{d₁,d₂,d₃,d₄,h}记为Z。Above, Z is the optimization result after each step of iterative calculation at the system level. The system-level design variable z={d ₁ ,d ₂ ,d ₃ ,d ₄ ,h} is the optimization result obtained through system-level optimization calculation, that is, a set of single-step optimal values at the system level {d ₁ ,d ₂ ,d ₃ ,d ₄ ,h} is denoted as Z.

在本具体实施例中，根据上述优化的CO模型，具体说明系统层与子系统层是如何确定换挡油缸2的尺寸参数向量x={d₁,d₂,d₃,d₄,h}的。In this specific embodiment, according to the above-mentioned optimized CO model, how the system layer and the subsystem layer determine the size parameter vector x={d ₁ ,d ₂ ,d ₃ ,d ₄ ,h} of the shift cylinder 2 of.

1.2系统层（sys）优化CO模型1.2 System layer (sys) optimization CO model

系统层优化CO模型为经济性模型，以换挡油缸的体积为设计目标，其数学优化模型包括两部分：优化的系统目标函数和子系统一致性约束，如以下表达式所示：The CO model optimized at the system level is an economic model, with the volume of the shift cylinder as the design target. Its mathematical optimization model includes two parts: the optimized system objective function and the subsystem consistency constraints, as shown in the following expression:

$s the s . . t t . . \{\begin{matrix} {J J}_{11} = = {Σ Σ}_{i i = = 11}^{44} {(({d d}_{i i} - - {d d}_{11 i i}^{* *}))}^{22} \leq \leq δ δ \\ {J J}_{22} = = {Σ Σ}_{i i = = 11}^{44} {(({d d}_{i i} - - {d d}_{22 i i}^{* *}))}^{22} \leq \leq δ δ \\ {J J}_{33} = = {(({d d}_{11} - - {d d}_{3131}^{* *}))}^{22} + + {(({d d}_{22} - - {d d}_{3232}^{* *}))}^{22} + + {(({d d}_{44} - - {d d}_{3434}^{* *}))}^{22} {+ +}^{{((h h - - {h h}_{33}^{* *}))}^{22} \leq \leq δ δ} \end{matrix} - - - - - - ((55))$

这里，F(z)为需要优化的系统目标函数；l为液压换档油缸2的长度，由换档行程lx和电磁阀（HSV₃和HSV₄）的间距决定；J_i是一致性约束，也是第i个子系统的目标函数。d_i为系统层的设计变量，d_1i ^*为第一子系统级的优化结果X₁中元素，d_2i ^*为第二子系统级的优化结果X₂中元素，d₃₁ ^*、d₃₂ ^*、d₃₄ ^*、h₃ ^*为第三子系统级的优化结果X₃中元素。Here, F(z) is the system objective function to be optimized; l is the length of the hydraulic shift cylinder 2, which is determined by the shift stroke lx and the distance between the solenoid valves (HSV ₃ and HSV ₄ ); J _i is the consistency constraint, It is also the objective function of the i-th subsystem. d _i is the design variable at the system level, d _1i ^* is the element in the optimization result X ₁ of the first subsystem level, d _2i ^* is the element in the optimization result X ₂ of the second subsystem level, d ₃₁ ^* , d ₃₂ ^* , d ₃₄ ^* and h ₃ ^* are elements in the optimization result X ₃ of the third subsystem level.

系统层的优化实质是寻找新向量Z，使其较前一个向量Z’更接近原问题的最优解，这使得各子系统根据向量Z优化得到的子系统的期望设计向量X₁，X₂，X₃之间的不一致度逐渐降低，因此在系统级优化问题中采用的一致性等式约束，即J_i（z）=0。这是种理想状态，只有当向量Z接近原问题的最优解时才满足。而在一般情况下，是不满足库恩-塔克（Kuhn-Tucker）条件，系统级等式约束拉格朗日（Lagrange）乘子不存在，是无解的。The essence of optimization at the system level is to find a new vector Z to make it closer to the optimal solution of the original problem than the previous vector Z', which makes the expected design vectors X ₁ and X ₂ of the subsystem obtained by optimizing the vector Z for each subsystem , the degree of inconsistency between X ₃ decreases gradually, so the consistency equality constraint adopted in the system-level optimization problem, that is, J _i (z)=0. This is an ideal state, which is satisfied only when the vector Z is close to the optimal solution of the original problem. In general, the Kuhn-Tucker condition is not satisfied, and the system-level equality constraint Lagrange multiplier does not exist, so there is no solution.

为此根据子系统间的不一致信息，构建系统级动态松弛算法，如下：Therefore, according to the inconsistency information between subsystems, a system-level dynamic relaxation algorithm is constructed, as follows:

定义Δ为子系统间的不一致信息：Define Δ as inconsistent information between subsystems:

Δ＝||X₁-X₂||+||X₂-X₃||+||X₃-X₁|| （6）Δ＝||X ₁ -X ₂ ||+||X ₂ -X ₃ ||+||X ₃ -X ₁ || (6)

令松弛量：δ＝(λ×Δ)²，其中0.5＜λ＜1 （7）Let the amount of relaxation: δ=(λ×Δ) ² , where 0.5<λ<1 (7)

则原系统层约束条件转化为：Then the original system layer constraints are transformed into:

$s the s . . t t . . \{\begin{matrix} {J J}_{11} = = {Σ Σ}_{i i = = 11}^{44} {(({d d}_{i i} - - {d d}_{11 i i}^{* *}))}^{22} \leq \leq δ δ \\ {J J}_{22} = = {Σ Σ}_{i i = = 11}^{44} {(({d d}_{i i} - - {d d}_{22 i i}^{* *}))}^{22} \leq \leq δ δ \\ {J J}_{33} = = {(({d d}_{11} - - {d d}_{3131}^{* *}))}^{22} + + {(({d d}_{22} - - {d d}_{3232}^{* *}))}^{22} + + {(({d d}_{44} - - {d d}_{3434}^{* *}))}^{22} {+ +}^{{((h h - - {h h}_{33}^{* *}))}^{22} \leq \leq δ δ} \end{matrix} - - - - - - ((88))$

原一致性等式约束变为不等式约束，δ是个动态量，会随着子系统间的不一致信息Δ不断变化，且随Δ变小，δ减小，为设计向量的下一步寻优提供合适的范围，使X₁、X₂、X₃逐步趋向一致。The original consistency equality constraint becomes an inequality constraint, and δ is a dynamic quantity, which will continue to change with the inconsistency information Δ between subsystems, and as Δ becomes smaller, δ decreases, providing a suitable value for the next step of optimization of the design vector range, so that X ₁ , X ₂ , and X ₃ tend to be consistent gradually.

1.3子系统1（sub1）优化模型1.3 Subsystem 1 (sub1) optimization model

子系统1的优化CO模型为力学模型，即换档油缸2的设计应满足力学要求，换档油缸2作用于活塞杆21上的力应能够克服各个换档过程所对应的换档力。过程1和过程3为挂档过程，换档油缸2的输出作用力应能克服其最大挂档力，过程2和过程4为摘档过程，该过程阻力小，取最大换档力的20%。最大换档力由原手动模式中的参数获得，换档手柄的挂档作用力最大为250N，经原手动机械结构转换到换挡油缸2的活塞杆21的作用点的作用力为1700N，即所需克服的最大换档力。根据表2的各过程中电磁阀的动作逻辑表，将摘档过程分为2个阶段：前70%需克服摘档力，后30%只要能保证活塞22往中位移动即可，在此选取克服阻力为50N。根据各过程的力学关系，建立如下所示的数学模型：The optimized CO model of subsystem 1 is a mechanical model, that is, the design of the shift cylinder 2 should meet the mechanical requirements, and the force of the shift cylinder 2 acting on the piston rod 21 should be able to overcome the shift force corresponding to each shift process. Process 1 and process 3 are gear-engaging processes, and the output force of shift cylinder 2 should be able to overcome its maximum gear-engaging force. Process 2 and process 4 are gear-removing processes. The resistance of this process is small, and take 20% of the maximum shifting force . The maximum shifting force is obtained from the parameters in the original manual mode. The gear shifting force of the shift handle is at most 250N, and the force transferred to the action point of the piston rod 21 of the shifting cylinder 2 through the original manual mechanical structure is 1700N, namely The maximum shifting force to overcome. According to the action logic table of the electromagnetic valve in each process in Table 2, the shifting process is divided into two stages: the first 70% needs to overcome the shifting force, and the last 30% only needs to ensure that the piston 22 moves to the neutral position. Here Select the overcoming resistance as 50N. According to the mechanical relationship of each process, the following mathematical model is established:

1.4子系统2（sub2）优化模型1.4 Subsystem 2 (sub2) optimization model

子系统2的优化CO模型为动力性模型。动力性主要通过换档时间进行体现，时间过长，动力中断过长，动力性能下降；时间过短，容易产生换档冲击，影响换档平顺性，因此要求换档时间应满足合适的取值范围，根据大量实车实验，换档时间t应控制在0.3s以内。The optimized CO model of subsystem 2 is a dynamic model. The power performance is mainly reflected by the shift time. If the time is too long, the power interruption is too long, and the power performance will decrease; if the time is too short, the shift shock will easily occur, which will affect the smoothness of the shift. Therefore, the shift time should meet an appropriate value. range, according to a large number of real vehicle experiments, the shift time t should be controlled within 0.3s.

换档过程为动态非线性过程，油压、流量等都是时变参量，无法精确求其换档时间，本具体实施例将其简化为匀速过程进行近似计算。过程1和过程3为挂档过程，只需控制单侧油腔充油即可，且前80％行程为消除空行程，负载较小取340N；过程2和过程4为摘空档过程，为实现快速摘档，前70％行程单侧油腔充油，后30％行程两侧油腔同时充油。以过程2为例进行换档时间求解说明，由平衡方程得：The shifting process is a dynamic nonlinear process, and the oil pressure and flow are all time-varying parameters, and the shifting time cannot be accurately calculated. This specific embodiment simplifies it into a uniform speed process for approximate calculation. Process 1 and process 3 are the process of shifting gears, only need to control the oil filling of one side of the oil chamber, and the first 80% of the stroke is to eliminate the idle stroke, and the load is small and take 340N; process 2 and process 4 are the process of removing the neutral gear, for Realize quick gear removal, the first 70% of the stroke is filled with oil on one side, and the oil chambers on both sides of the rear 30% of the stroke are filled with oil at the same time. Taking process 2 as an example to explain the solution of the shift time, the balance equation can be obtained:

由于活塞运动速度相等，即：Q_a/S₁＝Q_b/S₂ （11）Since the moving speed of the piston is equal, that is: Q _a /S ₁ = Q _b /S ₂ (11)

同时，根据流量和压差关系可得：At the same time, according to the relationship between flow and pressure difference:

前 $\{\begin{matrix} Q_{a}^{1} = C_{v} \sqrt{p_{a}^{1}} \\ Q_{b}^{1} = C_{v} \sqrt{p - p_{b}^{1}} \end{matrix},$ 后 $\{\begin{matrix} Q_{a}^{2} = C_{v} \sqrt{p_{a}^{2} - p} \\ Q_{b}^{2} = C_{v} \sqrt{p - p_{b}^{2}} \end{matrix} - - - (12)$ forward $\{\begin{matrix} Q_{a}^{1} = C_{v} \sqrt{p_{a}^{1}} \\ Q_{b}^{1} = C_{v} \sqrt{p - p_{b}^{1}} \end{matrix},$ back $\{\begin{matrix} Q_{a}^{2} = C_{v} \sqrt{p_{a}^{2} - p} \\ Q_{b}^{2} = C_{v} \sqrt{p - p_{b}^{2}} \end{matrix} - - - (12)$

联立式（7）、（8）、（9）可求得油缸工作过程中A腔内的油压：Simultaneous (7), (8), (9) can obtain the oil pressure in cavity A during the working process of the oil cylinder:

其中，τ＝S₁/S₂,F¹＝340N。Wherein, τ=S ₁ /S ₂ , F ¹ =340N.

联立式（12）和（13）即可获得过程2的动作时间：The action time of process 2 can be obtained by combining (12) and (13):

${t t}_{22} = = {t t}_{22}^{11} + + {t t}_{22}^{22} = = 0.7 0.7 {S S}_{22} {l l}_{c c} / / {Q Q}_{b b}^{11} + + 0.3 0.3 {S S}_{22} {l l}_{c c} / / {Q Q}_{b b}^{22} - - - - - - ((1414))$

同理，可求得其它三个过程的腔内油压，建立时间为约束的数学模型，如下：In the same way, the oil pressure in the cavity of the other three processes can be obtained, and a mathematical model constrained by time can be established, as follows:

$\{\begin{matrix} min min {J J}_{22} = = {Σ Σ}_{i i = = 11}^{44} {(({d d}_{22 i i} - - {d d}_{i i}^{* *}))}^{22},, i i = = 1,2,3,4 1,2,3,4 \\ s the s . . t t . . {t t}_{11} = = {t t}_{11}^{11} + + {t t}_{11}^{22} = = 0.8 0.8 {S S}_{11} {l l}_{c c} / / {Q Q}_{11 a a}^{11} + + 0.2 0.2 {S S}_{11} {l l}_{c c} / / {Q Q}_{11 a a}^{22} \\ {t t}_{22} = = {t t}_{22}^{11} + + {t t}_{22}^{22} = = 0.7 0.7 {S S}_{22} {l l}_{c c} / / {Q Q}_{22 b b}^{11} + + 0.3 0.3 {S S}_{22} {l l}_{c c} / / {Q Q}_{22 b b}^{22} \\ {t t}_{33} = = {t t}_{33}^{11} + + {t t}_{33}^{22} = = 0.8 0.8 {S S}_{22} {l l}_{c c} / / {Q Q}_{22 b b}^{11} + + 0.2 0.2 {S S}_{22} {l l}_{c c} / / {Q Q}_{33 b b}^{22} \\ {t t}_{44} = = {t t}_{44}^{11} + + {t t}_{44}^{22} = = 0.7 0.7 {S S}_{33} {l l}_{c c} / / {Q Q}_{44 a a}^{11} + + 0.3 0.3 {S S}_{33} {l l}_{c c} / / {Q Q}_{44 a a}^{22} \\ {t t}_{j j} \leq \leq 0.3 0.3 s the s,, j j = = 1,2,3,4 1,2,3,4 \end{matrix} - - - - - - ((1515))$

其中，P_ɑ、P_b分别表示液压换挡油缸A、B腔的油压，上标1、2分别表示前后两个工作阶段；t_j表示四个换档行程的换档时间。Among them, P _ɑ and P _b represent the oil pressures of hydraulic shift cylinders A and B respectively, and the superscripts 1 and 2 represent the front and rear working stages respectively; t _j represents the shift time of the four shift strokes.

1.5子系统3（sub3）优化模型1.5 Subsystem 3 (sub3) optimization model

子系统3的优化CO模型为可靠性模型。由机械设计手册可得，其可靠性主要体现在强度的校核，即壁厚校核和活塞杆21的强度校核，活塞杆21采用螺纹联接时，活塞杆21的危险截面为螺纹退刀槽处。根据机械设计手册，可得其数学优化模型为：The optimized CO model of subsystem 3 is a reliability model. It can be obtained from the mechanical design manual that its reliability is mainly reflected in the strength check, that is, the wall thickness check and the strength check of the piston rod 21. When the piston rod 21 is threaded, the dangerous cross section of the piston rod 21 is thread retraction. slot. According to the mechanical design manual, the mathematical optimization model can be obtained as:

$\{\begin{matrix} min min {J J}_{33} = = {(({d d}_{3131} - - {d d}_{11}^{* *}))}^{22} {+ +}^{{(({d d}_{3232} - - {d d}_{22}^{* *}))}^{22} + + {(({d d}_{3434} - - {d d}_{44}^{* *}))}^{22}} \\ + + (({h h}_{33} - - {h h}^{* *})) \\ s the s . . t t . . δ δ = = \frac{{P P}_{y the y} D D.}{22 [[σ σ]]} = = \frac{1.5 1.5 P P \times \times {22 d d}_{44}}{22 \times \times (({σ σ}_{b b} / / {n no}_{11}))} \\ {σ σ}_{n no} = = \sqrt{{((\frac{KF KF}{π π {d d}_{00}^{22} / / 44}))}^{22} + + 33 {((\frac{{K K}_{11} KF KF {d d}_{11}}{0.2 0.2 {d d}_{00}^{33}}))}^{22}} \\ h h > > δ δ \\ {σ σ}_{n no} \leq \leq [[σ σ]] \end{matrix} - - - - - - ((1616))$

其中，δ为缸壁许用厚度；F表示活塞杆21的最大拉应力，对应过程3的活塞杆21的作用力；d₀为活塞杆21的端部螺纹内径d₀=d₁-1.0825e，e为螺距；σ_n表示活塞杆21的危险截面处（螺纹退刀槽处）的合成应力；[σ]为许用应力，[σ]=σ_s/n₂，σ_s为螺纹屈服点，n₂为安全系数。Among them, δ is the allowable thickness of the cylinder wall; F represents the maximum tensile stress of the piston rod 21, corresponding to the force of the piston rod 21 in process 3; d ₀ is the inner diameter of the end thread of the piston rod 21 d ₀ =d ₁ -1.0825e , e is the thread pitch; σ _n represents the resultant stress at the dangerous section of the piston rod 21 (thread undercut); [σ] is the allowable stress, [σ]=σ _s /n ₂ , σ _s is the thread yield point , n ₂ is the safety factor.

可以利用Optimization和Matlab两种组件建立CO模型。计算过程需在系统层Optimization组件中给初始变量值赋值。可根据载荷F₁选择d₃的尺寸，再根据各尺寸之间的大小关系（h<d₁<d₃<d₂<d₄），选择一组初值。Two components, Optimization and Matlab, can be used to build CO models. The calculation process needs to assign initial variable values in the Optimization component of the system layer. The size of d ₃ can be selected according to the load F ₁ , and then a set of initial values can be selected according to the size relationship between each size (h<d ₁ <d ₃ <d ₂ <d ₄ ).

本具体实施例中，选择各变量初始值依次为10、20、35、40、50mm。系统层和子系统层的模型优化算法均选择遗传算法GA，经过1494次计算，得到表4所示结果。由于液压缸为标准件，其尺寸参数有标准的取值范围。因此采用以下方法得到优化设计参数：依据机械设计手册选择与优化结果相近的两组变量取值，通过子系统层数学模型的验证，选择满足条件的较优值，得到优化后的设计结果（见表4）。In this specific embodiment, the initial values of each variable are selected as 10, 20, 35, 40, and 50 mm in turn. Both the model optimization algorithms of the system layer and the subsystem layer choose the genetic algorithm GA, and after 1494 calculations, the results shown in Table 4 are obtained. Since the hydraulic cylinder is a standard part, its size parameters have a standard range of values. Therefore, the following method is used to obtain the optimized design parameters: according to the mechanical design manual, select two groups of variable values that are similar to the optimized results, and through the verification of the subsystem layer mathematical model, select the optimal value that meets the conditions, and obtain the optimized design results (see Table 4).

表4设计变量的优化结果Table 4 Optimization results of design variables

选位油缸的设计同样也需要考虑选位时间、选位力、可靠性等约束条件，因此也采用与换挡油缸类似的设计方法。由于选位油缸的设计参数及方法均与换档油缸类似，不再重复说明。The design of the position selection cylinder also needs to consider constraints such as position selection time, position selection force, and reliability, so a design method similar to that of the gear shift cylinder is also adopted. Since the design parameters and methods of the position selection cylinder are similar to those of the shift cylinder, the description will not be repeated.

从上表4优化前后数据可以看出：通过本发明的方法获得的结果与之前的结构相比，油缸尺寸明显减小，从而减小了AMT液压换挡机构的体积，降低了成本。由于油缸内腔尺寸相应减小，那么单次挂档过程中使用的液压油体积也减少，进而降低油液损失，提高了油缸的工作效率。From the data before and after optimization in Table 4 above, it can be seen that compared with the previous structure, the size of the oil cylinder is significantly reduced by the method of the present invention, thereby reducing the volume of the AMT hydraulic shifting mechanism and reducing the cost. Since the size of the inner cavity of the oil cylinder is correspondingly reduced, the volume of hydraulic oil used in a single shifting process is also reduced, thereby reducing oil loss and improving the working efficiency of the oil cylinder.

从表5数据可以看出，优化前后的油缸输出作用力均能满足换档力要求，优化后力相对较小，提高油缸的有效利用率；优化后各过程动作时间较优化前总体减小均能保证在250ms内，缩短换档时间，减少动力中断的时间，提高了车辆的动力性。From the data in Table 5, it can be seen that the output force of the oil cylinder before and after optimization can meet the shift force requirements, and the force after optimization is relatively small, which improves the effective utilization of the oil cylinder; the action time of each process after optimization is generally reduced compared with that before optimization. It can guarantee that within 250ms, the shifting time is shortened, the power interruption time is reduced, and the dynamic performance of the vehicle is improved.

表5优化前后油缸换档力和动作时间的对比Table 5 Comparison of cylinder shift force and action time before and after optimization

由上可见，本发明的设计方法为正向设计方法，依据协同优化方法，确定目标函数，在满足约束条件下通过迭代方法逐步收敛到最优解。与传统设计的试凑验证法相比，目标明确避免盲目性。It can be seen from the above that the design method of the present invention is a forward design method. According to the collaborative optimization method, the objective function is determined, and the optimal solution is gradually converged to the optimal solution through an iterative method under satisfying constraint conditions. Compared with the trial and error method of traditional design, the goal is clear and blindness is avoided.

以上所述，仅为本发明的具体实施方式，但本发明的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本发明揭露的技术范围内，可轻易想到变化或替换，都应涵盖在本发明的保护范围之内。因此，本发明的保护范围应所述以权利要求的保护范围为准。The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Anyone skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present invention. Should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. a design method of mechanical automatic transmission AMT hydraulic shift mechanism, described AMT hydraulic shift mechanism comprises oil cylinder, it is characterized in that, described method comprises:

Constructing a collaborative optimization CO model for the oil cylinder in the AMT hydraulic shift mechanism, the CO model includes a system-level objective function and three subsystem-level objective functions;

Through iterative calculation, determine the optimal solution of the CO model, wherein the optimal solution is the required size parameter vector of the oil cylinder;

The size of the AMT hydraulic shift mechanism is determined according to the size parameter vector of the oil cylinder.

2. method according to claim 1, is characterized in that, described for the oil cylinder in the described AMT hydraulic shifting mechanism builds CO model, comprises:

Construct the system objective function of the oil cylinder;

A subsystem objective function of the oil cylinder is constructed, wherein the subsystem objective function is a consistency constraint condition of the system objective function.

3. The method of claim 2, wherein,

The objective function of the system is

f (z) = π {(\frac{d_{4}}{2} + h)}^{2} (l + 0.006);

The objective function of the subsystem is

J_{i} (x_{i}) = Σ_{j}^{4} {(x_{ij} - z_{j}^{*})}^{2}, i = 1,2,3;

Wherein, l is the length of the oil cylinder, x _i is the subsystem design variable: x ₁ ={d ₁ ,d ₂ ,d ₃ ,d ₄ }, x ₂ ={d ₁ ,d ₂ ,d ₃ ,d ₄ }, x ₃ ={d ₁ ,d ₂ ,d ₄ ,h}, z _j ^* is the element in the optimization result of the system layer, x _ij is the jth design variable of the i-th subsystem, d ₁ is the The diameter of the output end, d ₂ is the inner diameter of the B chamber of the oil cylinder, d ₃ is the inner diameter of the piston, d ₄ is the inner diameter of the A chamber of the oil cylinder or the outer diameter of the piston, and h is the cylinder wall thickness of the A chamber of the oil cylinder.

4. The method according to any one of claims 1 to 3, characterized in that, by iterative calculation, determining the optimal solution of the CO model comprises:

The system level assigns the design vector expectation value Z to the three subsystem levels, and each subsystem in the three subsystem levels, under the premise of satisfying its own constraints, respectively obtains its design variables and the target provided by the system level to the subsystem The difference between the values is the minimum value, and the optimization result X _i is returned to the system level, where i=1, 2, 3;

The system level constructs consistency constraints between subsystems according to the optimization results Xi _returned by the three subsystem levels, and under the constraints, finds the minimum value of the system objective function, and passes the optimization result Z' to the subsystem level again as the new design vector expectation;

After multiple iterations between system-level optimization and subsystem-level optimization, the optimal solution of the CO model is finally determined.

5. The method according to claim 4, wherein the determining the optimal solution of the CO model comprises:

Determine the optimal solution of the system objective function of the oil cylinder according to the consistency constraint condition;

According to the load constraint condition, the time constraint condition and the strength constraint condition, the optimal solution of the objective function of the subsystem of the oil cylinder is determined.

6. The method according to claim 5, wherein the determining the optimal solution of the system objective function of the oil cylinder according to the consistency constraint condition comprises:

min min F f ((z z)) = = π π {((\frac{{d d}_{44}}{22} + + h h))}^{22} ((l l + + 0.006 0.006))

s the s . . t t . . \{\begin{matrix} {J J}_{11} = = {Σ Σ}_{i i = = 11}^{44} {(({d d}_{i i} - - {d d}_{11 i i}^{* *}))}^{22} \leq \leq δ δ \\ {J J}_{22} = = {Σ Σ}_{i i = = 11}^{44} {(({d d}_{i i} - - {d d}_{22 i i}^{* *}))}^{22} \leq \leq δ δ \\ {J J}_{33} = = {(({d d}_{11} - - {d d}_{3131}^{* *}))}^{22} + + {(({d d}_{22} - - {d d}_{3232}^{* *}))}^{22} + + {(({d d}_{44} - - {d d}_{3434}^{* *}))}^{22} {+ +}^{{((h h - - {h h}_{33}^{* *}))}^{22} \leq \leq δ δ} \end{matrix}

Among them, F(z) is the system objective function to be optimized; d _i is the design variable of the system layer: d ₁ is the diameter of the output end of the piston rod, d ₂ is the inner diameter of the B cavity of the oil cylinder, d ₃ is the inner diameter of the piston, d ₄ is the inner diameter of the A cavity of the oil cylinder or the outer diameter of the piston, h is the thickness of the cylinder wall of the A cavity of the oil cylinder, l is the length of the oil cylinder, J ₁ is the objective function of the first subsystem level, J ₂ is the first subsystem level The objective function of the second subsystem level, J ₃ is the objective function of the third subsystem level, d _1i ^* is the element in the optimization result X of the _first subsystem level, and d _2i ^* is the optimization result X of the second subsystem level ₂ , d ₃₁ ^* , d ₃₂ ^* , d ₃₄ ^* , h ₃ ^* are elements in X ₃ of the optimization result of the third subsystem level.

7. The method according to claim 5, wherein the determining the optimal solution of the subsystem objective function of the oil cylinder according to the load constraint condition, time constraint condition and strength constraint condition comprises:

Determine the optimal solution of the objective function of the first subsystem of the oil cylinder according to the load constraint condition;

Determine the optimal solution of the objective function of the second subsystem of the oil cylinder according to the time constraints;

According to the strength constraint condition, the optimal solution of the objective function of the third subsystem of the oil cylinder is determined.

8. The method according to claim 7, wherein the determining the optimal solution of the first subsystem objective function of the oil cylinder according to the load constraint condition comprises:

min min {J J}_{11} = = {Σ Σ}_{i i = = 11}^{44} {(({d d}_{11 i i} - - {d d}_{i i}^{* *}))}^{22},, i i = = 1,2,3,4 1,2,3,4

Among them, F _m is the output force of each process of the oil cylinder, m=1, 2, 3, 4, the superscripts 1 and 2 of F _m represent the two processes before and after respectively; S _n is the effective working area of the corresponding process, n=1, 2,3; P is the main pressure of the oil source, which is determined by the oil source of the system. It is not a controllable parameter of the AMT hydraulic shift mechanism itself, and it is not within the optimization range. The output oil pressure is a variable value P∈[4,4.5]Mpa , in this specific embodiment, the minimum value of oil pressure is selected for calculation; P ₀ is taken as 0 for the fuel tank oil pressure; F _max is the maximum shift force of 1700N.

9. The method according to claim 7, wherein the determining the optimal solution of the second subsystem objective function of the oil cylinder according to the time constraints comprises:

\{\begin{matrix} min min {J J}_{22} = = {Σ Σ}_{i i = = 11}^{44} {(({d d}_{22 i i} - - {d d}_{i i}^{* *}))}^{22},, i i = = 1,2,3,4 1,2,3,4 \\ s the s . . t t . . {t t}_{11} = = {t t}_{11}^{11} + + {t t}_{11}^{22} = = 0.8 0.8 {S S}_{11} {l l}_{c c} / / {Q Q}_{11 a a}^{11} + + 0.2 0.2 {S S}_{11} {l l}_{c c} / / {Q Q}_{11 a a}^{22} \\ {t t}_{22} = = {t t}_{22}^{11} + + {t t}_{22}^{22} = = 0.7 0.7 {S S}_{22} {l l}_{c c} / / {Q Q}_{22 b b}^{11} + + 0.3 0.3 {S S}_{22} {l l}_{c c} / / {Q Q}_{22 b b}^{22} \\ {t t}_{33} = = {t t}_{33}^{11} + + {t t}_{33}^{22} = = 0.8 0.8 {S S}_{22} {l l}_{c c} / / {Q Q}_{22 b b}^{11} + + 0.2 0.2 {S S}_{22} {l l}_{c c} / / {Q Q}_{33 b b}^{22} \\ {t t}_{44} = = {t t}_{44}^{11} + + {t t}_{44}^{22} = = 0.7 0.7 {S S}_{33} {l l}_{c c} / / {Q Q}_{44 a a}^{11} + + 0.3 0.3 {S S}_{33} {l l}_{c c} / / {Q Q}_{44 a a}^{22} \end{matrix}

Among them, P _ɑ and P _b represent the oil pressures of hydraulic cylinders A and B respectively, superscripts 1 and 2 represent the two working stages before and after; t _j represents the shift time of the four shift strokes.

10. The method according to claim 7, wherein the determination of the optimal solution of the objective function of the third subsystem of the oil cylinder according to the strength constraint condition comprises:

\{\begin{matrix} min min {J J}_{33} = = {(({d d}_{3131} - - {d d}_{11}^{* *}))}^{22} {+ +}^{{(({d d}_{3232} - - {d d}_{22}^{* *}))}^{22} + + {(({d d}_{3434} - - {d d}_{44}^{* *}))}^{22}} \\ + + (({h h}_{33} - - {h h}^{* *})) \\ s the s . . t t . . δ δ = = \frac{{P P}_{y the y} D D.}{22 [[σ σ]]} = = \frac{1.5 1.5 P P \times \times {22 d d}_{44}}{22 \times \times (({σ σ}_{b b} / / {n no}_{11}))} \\ {σ σ}_{n no} = = \sqrt{{((\frac{KF KF}{π π {d d}_{00}^{22} / / 44}))}^{22} + + 33 {((\frac{{K K}_{11} KF KF {d d}_{11}}{0.2 0.2 {d d}_{00}^{33}}))}^{22}} \\ h h > > δ δ \\ {σ σ}_{n no} \leq \leq [[σ σ]] \end{matrix}

Among them, δ is the allowable thickness of the cylinder wall; F represents the maximum tensile stress of the piston rod; d ₀ is the inner diameter of the end thread of the piston rod, d ₀ =d ₁ -1.0825e, e is the pitch; σ _n represents the risk of the piston rod The resultant stress at the section; [σ] is the allowable stress, [σ]=σ _s /n ₂ , σ _s is the thread yield point, and n ₂ is the safety factor.