喜歡就充值下載吧。。。資源目錄里展示的全都有，，下載后全都有,,請放心下載，原稿可自行編輯修改 【QQ：414951605 可咨詢交流】=====================
喜歡就充值下載吧。。。資源目錄里展示的全都有，，下載后全都有,,請放心下載，原稿可自行編輯修改 【QQ：1304139763 可咨詢交流】=====================
喜歡就充值下載吧。。。資源目錄里展示的全都有，，下載后全都有,,請放心下載，原稿可自行編輯修改 【QQ：1304139763 可咨詢交流】=====================
本科學(xué)生畢業(yè)設(shè)計
基于ADAMS軟件轎車前懸架動態(tài)模擬與仿真
系部名稱： 汽車工程系
專業(yè)班級： 車輛工程 B05-17班
學(xué)生姓名： 李圣明
指導(dǎo)教師： 王慧文
職 稱： 教 授
黑 龍 江 工 程 學(xué) 院
二○○九年六月
The Graduation Design for Bachelor's Degree
Based on ADAMS Software Car Suspension Dynamic Modeling and Simulation
Candidate：Li Shengming
Specialty：Vehicle Engineering
Class：B05-17
Supervisor：Prof. Wang Huiwen
Heilongjiang Institute of Technology
2009-06·Harbin
黑龍江工程學(xué)院本科生畢業(yè)設(shè)計
摘 要
本設(shè)計結(jié)合懸架設(shè)計知識，對麥弗遜懸架進(jìn)行了設(shè)計計算，詳細(xì)分析了懸架導(dǎo)向機(jī)構(gòu)空間關(guān)鍵點坐標(biāo)的計算方法，在此基礎(chǔ)上，應(yīng)用虛擬樣機(jī)技術(shù)，在ADAMS/View中對麥弗遜式懸架進(jìn)行合理簡化并建模，并對模型進(jìn)行了參數(shù)化，設(shè)計輸入初始參數(shù)的功能，即改變初始參數(shù)就能快速生成不同的懸架模型，提高了仿真分析以及優(yōu)化設(shè)計的效率，使平臺具有開放性。分析研究了所需優(yōu)化的目標(biāo)參量(如車輪定位角、車輪側(cè)滑量)及其函數(shù)表達(dá)式。進(jìn)行了懸架動力學(xué)仿真分析，研究懸架各性能參數(shù)在車輪跳動過程中的變化趨勢，并指出需要改進(jìn)的地方。分析每個設(shè)計變量的變化對樣機(jī)性能的影響，提出優(yōu)化設(shè)計的方案。再次進(jìn)行仿真，對比分析了優(yōu)化前后的仿真結(jié)果，并評價了優(yōu)化方案。優(yōu)化后懸架的性能明顯提高，驗證了優(yōu)化方案的可行性，并完成虛擬設(shè)計及試驗。最后運(yùn)用Pro/E軟件對麥弗遜懸架進(jìn)行模型的建立。
本設(shè)計研究的目的和意義為在試制前的階段進(jìn)行設(shè)計和試驗仿真，并且提出改進(jìn)意見，在產(chǎn)品制造出之前，就可以發(fā)現(xiàn)并更正設(shè)計缺陷，完善設(shè)計方案，縮短開發(fā)周期，提高設(shè)計質(zhì)量和效率。并借助此平臺完成了小型觀光旅游車的前懸架設(shè)計工作，驗證了該平臺的實用性和通用性。
關(guān)鍵詞：麥弗遜式懸架；虛擬設(shè)計；仿真；ADAMS；Pro/E
ABSTRACT
On the basis of the Suspension design, this paper calculated a detailed requirements for McPherson suspension structure, analyzed the suspension oriented institutions, prepared a simple calculation procedures for the parameter select of the initial suspension oriented institutions. By virtual prototyping technology, I simplified and built a model of Macperson suspension in ADAMS/View, made the model parameters, then the model was open, and prepared the necessary measuring function. I discussed the performance of the front wheel alignment parameters in a front wheel vehicle positioning. The model was a virtual front suspension test platform. This thesis analyzed the change trend of the suspension performance parameters in the process of flopping the wheel. The impacts of its changes in the trend of design variables are also analyzed, make an optimized design of the program, with the comparative analysis to verify the feasibility of the optimization program before and after the optimization, the suspension’s key data was generated, the virtual design and test were finished. Finally I used Pro/E for McPherson a modeling.
The purpose and significance of the article lies in establishing a vehicle McPherson suspension of the virtual design platform for virtual simulation test, pioneering a more scientific approach for the design and development of McPherson suspension, combining the automobile design theory, resolving problems in the field of kinematics and dynamics, improving the quality of design. This research will also contribute to enhance the ability to independently develop products for China’s auto mobile industry.
Key words: MacPherson Suspension; Viertual Designing; Simulation; ADAMS; Pro/E
II
黑龍江工程學(xué)院本科生畢業(yè)設(shè)計
目 錄
摘要………………………………………………………………………………………Ⅰ
Abstract …………………………………………………………………………………Ⅱ
第1章 緒論………………………………………………………………………………1
1.1課題研究的目的和意義……………………………………………………………1
1.2汽車懸架技術(shù)研究現(xiàn)狀和發(fā)展趨勢………………………………………………2
1.3設(shè)計的研究內(nèi)容和方法……………………………………………………………4
第2章 麥弗遜懸架的概述……………………………………………………………6
2.1 懸架作用和組成分類………………………………………………………………6
2.1.1懸架的分類……………………………………………………………………6
2.1.2 懸架的組成…………………………………………………………………7
2.2麥弗遜懸架的特點…………………………………………………………………8
2.3麥弗遜懸架的結(jié)構(gòu)分析……………………………………………………………10
2.4本章小結(jié)……………………………………………………………………………11
第3章 懸架設(shè)計計算…………………………………………………………………12
3.1懸架的特性參數(shù)……………………………………………………………………12
3.1.1懸架的彈性特性……………………………………………………………12
3.1.2阻尼特性……………………………………………………………………13
3.1.3非簧載質(zhì)量…………………………………………………………………13
3.2螺旋彈簧的設(shè)計計算………………………………………………………………13
3.2.1螺旋彈簧計算公式…………………………………………………………14
3.2.2螺旋彈簧的計算……………………………………………………………16
3.3減振器的計算………………………………………………………………………17
3.4懸架導(dǎo)向機(jī)構(gòu)設(shè)計分析……………………………………………………………19
3.4.1懸架導(dǎo)向機(jī)構(gòu)空間位置的分析………………………………………19
3.5懸架結(jié)構(gòu)元件的選取………………………………………………………………22
3.6本章小結(jié)……………………………………………………………………………23
第4章 基于ADAMS/View麥弗遜懸架建?！?4
4.1仿真軟件ADAMS的介紹…………………………………………………………24
4.1.1 ADAMS的簡介……………………………………………………………24
4.1.2 ADAMS軟件的優(yōu)點………………………………………………………26
4.2 在ADAMS/View中創(chuàng)建懸架模型………………………………………………27
4.3模型參數(shù)化…………………………………………………………………………30
4.3.1 創(chuàng)建設(shè)計變量………………………………………………………………30
4.3.2 關(guān)鍵點參數(shù)化………………………………………………………………32
4.3.3 實體參數(shù)化…………………………………………………………………34
4.3.4 輸入?yún)?shù)的修改界面………………………………………………………34
4.4本章小結(jié)……………………………………………………………………………35
第5章 基于ADAMS/View麥弗遜懸架的仿真及優(yōu)化分析…………………36
5.1所需優(yōu)化的目標(biāo)參量的分析………………………………………………………36
5.2懸架運(yùn)動仿真………………………………………………………………………39
5.3設(shè)計參數(shù)的研究分析………………………………………………………………47
5.3.1 參數(shù)化分析方法……………………………………………………………47
5.3.2 設(shè)計研究……………………………………………………………………47
5.4目標(biāo)參量的優(yōu)化……………………………………………………………………52
5.4.1 提出優(yōu)化方案………………………………………………………………52
5.4.2 優(yōu)化后結(jié)果…………………………………………………………………53
5.4.3 優(yōu)化結(jié)果的評價……………………………………………………………55
5.5本章小結(jié)……………………………………………………………………………55
第6章 基于Pro/E的懸架模型建立………………………………………………56
6.1 Pro/E軟件的介紹…………………………………………………………………56
6.2懸架模型的建立……………………………………………………………………56
6.2.1零件的三維實體建模………………………………………………………56
6.2.2其它零件的三維實體建?！?0
6.2.3裝配懸架……………………………………………………………………61
6.3本章小結(jié)……………………………………………………………………………62
結(jié)論………………………………………………………………………………………63
參考文獻(xiàn)…………………………………………………………………………………64
致謝………………………………………………………………………………………65
附錄………………………………………………………………………………………66
黑龍江工程學(xué)院本科生畢業(yè)設(shè)計
附 錄
Introduction of vehicle suspension
Vehicle suspension types and working principle
Select different criteria, different suspension in accordance with the classification of whether the axle disconnect, can be divided into independent suspension and non-independent suspension, the so-called non-independent suspension, both sides of the wheel axle by a monolithic connected with the wheel axle, together with the suspension and chassis through the flexible connection. Characteristics of the wheel when the side of the road shocks encountered beating, there are bound to lead to the other side of the wheel in the car horizontal swing plane, independent suspension is made axle disconnect, and each side of the wheel can be adopted elastic suspension and frame connections, the structure of the complex than that of non-independent suspension, but the wheels on both sides when beating alone can increase the comfort ride, according to the suspension damping and stiffness of whether changes in driving conditions with the change can be divided into passive suspension, semi-active suspension, full-active suspension. Semi-active suspension damping level can also be divided according to class and there are no two types of class-type, although modern automotive suspension a large variety of different structures, but generally by the elastic element, damping components and component-oriented composition. Vehicle suspension model shown in Figure [1] The working principle is: when the impact on automobile tires, the elastic element of the impact of the buffer to prevent the staff of automotive components and damage, but the impact of flexible parts will be produced by prolonged vibration , easy for the driver fatigue accident, it must be a fast decay component damping vibration, shocks when the wheels were beating, the path should be to meet certain requirements, otherwise they will reduce the vehicle ride comfort and stability-oriented component in the transmission at the same time, the need for direction control.
- Unsprung mass - Body mass 、- Spring vibration isolation c- Damper u- Action device l- Tires
Figure one Three of the model suspension
McPherson independent suspension characteristics
McPherson suspension in part by the under arm, steering knuckle assembly (including the shock absorber lower body, wheel axle, brake plate, etc.), steering cross bar, shock absorber upper body, steering rack, wheel assembly , rigid body composed of a total of seven. Damper on
Body with universal joints A hinge connected with the body, steering and shock absorber assembly upper body section cylindrical hinge with bound B, relative to the first half of the shock absorber for axial and rotational movement; under one arm through the rotating hinge F, G connected with the body (one of them is bound to virtual), relative to body up and down swing, the other side through the ball joints and steering knuckle assembly E phase; turned horizontal rod end ball joints C through the steering knuckle assembly and connected to the other side through the universal joints and steering rack hinge connected H; steering rack by moving hinge I connected with the vehicle can be moved around relative body; wheel assembly and the steering knuckle hinge assembly D through the rotation linked to kinematic analysis, the body together with the ground is fixed McPherson independent suspension with a simple structure, non-sprung mass of small, easy engine and steering arrangement, suitable for various forms of spring in the same match as well as to achieve a high degree of auto-body the advantages of regulation. However, due to the location of the kingpin axis and damper hinge connecting the body and cross arm connected with the steering knuckle hinge connection center, so when the suspension in the deformation, the kingpin axis is also changed, front wheel alignment Tread parameters and will also be changed, and change can be very heavy. Therefore, if the structural design of improper suspension, it will greatly affect the use of performance automotive products (such as turning heavy shimmy, side tire wear, tire life impact, etc.)
Hanging at the development's history and current situation
Perfect is the eternal pursuit of mankind. Appears in the carriage, in order to ride more comfortable, humans have been on the coach's suspension - leaf spring carried out tireless explorations, in 1776, with the leaf spring carriage patented, and have been using the 30s to the 20th century, spring before the leaves have been gradually replaced by coil spring, after the car was born, along with in-depth study of the suspension, have a torsion bar springs, gas springs, rubber springs, leaf springs and other elastic parts, emerged in the world in 1934 the first of a the composition of the passive coil spring suspension. Passive suspension model in Figure 1 (a) passive suspension parameters as shown in the light of experience or method to determine the optimum design, moving the process remain unchanged, it is a series of road compromise, it is difficult to adapt to all kinds of complicated traffic, damping the effect of poor, in order to overcome this shortcoming, the use of a non-linear spring stiffness and body height adjustment method, although to a certain extent, but can not eradicate the drawbacks of passive suspension. Mainly used in middle and low passive suspension cars, the modern car with front suspension generally horizontal Stabilizer of McPherson suspension, such as Santana, Charade, Sail and other vehicles, more choice of rear suspension , there are composite longitudinal arm suspension and multi-link suspension, semi-active suspension of the research work started in 1973 by DA Cro sby and DC Karnopp model first put forward, such as 1 (b). semi-active suspension to changes in the main damping suspension, usually less consider changing the stiffness of the suspension. The working principle is: according to the quality of spring on the relative speed of the wheel response to feedback signals, such as acceleration response, in accordance with the laws regulating the control of a certain spring stiffness or the damping force, semi-active suspension force generated with passive suspension, but its damping or stiffness coefficient can be run in accordance with state regulation, which is very similar to active suspension, a class-type semi-active suspension damping is divided into several stages, the damping level by the driver under the "road sense" to choose or automatically by the sensor signals, non-stage semi-active suspension based on road car and driving conditions, the damping of the suspension in a few milliseconds from the smallest to the largest class-free adjustment. Semi-active suspension as a result of simple structure, the work does not require the power consumption of vehicles and can be achieved with the active suspension is similar to the performance, with good development prospects With the continuous development of road traffic, vehicle speed has been very large increase in passive suspension defects has gradually become the bottleneck to improve vehicle performance, for which it was developed taking into account the comfort and stability of the active suspension control. The concept of active suspension in 1954 in the United States General Motors Corp. first proposed suspension design, the active suspension model in Figure 1 (c) below, it is the basis of passive suspension to increase the stiffness and damping adjustable control device, so that in any road vehicle suspension to maintain the best running. Control devices are usually measured by the system, feedback control systems, energy systems and so on. 20th century 80's, world famous automobile companies and manufacturers competing for the research and development of such a suspension, Toyota, Lotus, Volvo, Mercedes-Benz cars, such as in a more successful experiment. Automotive active suspension devices, even in adverse road at high speed, very smooth body, tire noise, steering and braking to maintain the level of the body, and there is a very comfortable ride, but the complex structure of high energy consumption, high cost reliability problems. For various reasons, the vast majority of our used car passive suspension, in the semi-active and active suspension late start of the study, the gap with foreign countries [5]. In Western developed countries, the semi-active suspension in the late 20th century, 80 mature, Ford and Nissan cars on the first application, to obtain good results, in spite of the early-active suspension, but the control of complex, and involves many disciplines, has been very difficult to have a major breakthrough. 20th century 90's, only applies to large displacement of luxury cars, not the domestic automotive products using this technology is reported that only Beijing Institute of Technology and Tongji University, a small number of units, such as active suspension research.
The development trend of suspension
Dynamic suspension is a traditional mechanical structure, rigidity and damping are adjustable in accordance with the random vibration theory, it can only guarantee that the road conditions in a particular good result to achieve, but it is a mature theory, simple structure, reliable performance, cost relatively low and no additional energy, which is most widely used, in our country at this stage, there is still a high research value of the performance of passive suspension L focused on three aspects: ① to carry out stress analysis on the car after the establishment of mathematical model, and then use computer simulation techniques or finite element method to find the optimal parameters of the suspension; ② study variable just springs and variable shock absorber damping, so that the vast majority of traffic on the suspension in good working condition ; ③ research-oriented institutions to meet the automotive suspension ride comfort under the premise of the stability of a large increase in L semi-active suspension of the study focused on two aspects: ① the implementation of strategy; ② Research actuator damping L There are two main adjustable shock absorber, and the other is by changing the size of Orifice damping adjustment, and the other is by changing the viscous liquid vibration damping adjustment, Orifice size, generally through the solenoid valve or stepper motor There are no class or regulation, the higher the cost of this method, the structure of the complex, by changing the viscous damping fluid to change the damping coefficient, simple structure, low cost, no noise and the impact of such characteristics, it is the main direction. Abroad, to change the method of viscous fluid damping mainly ER fluids and magneto-rheological fluid in two. Beijing Institute of Technology, Professor Yi-Ming Zhang a damping adjustable semi-active suspension research, forest for the suspension control of adaptive decision-making research, Professor Chen Zhuoru HIT of the adaptive control of vehicles carried out a study, Study on the implementation of the strategy is through the identification of performance indicators, and then proceed to the controller's settings. At present, the fuzzy control more applications in this regard. Active suspension research focused on two aspects: ① reliability; ② actuators; active suspension as a result of the use of a large number of sensors, microcontroller, and a variety of input-output interface circuits, components to reduce the suspension to increase the reliability, so increasing the degree of component integration is an insurmountable stage . Research line is mainly used in place of hydraulic devices for electrical devices, aerodynamic system of permanent magnet linear servo motor and DC servo motor with a more straight-line advantages of the future will be the executing agency to replace the hydraulic accumulator L to use the electromagnetic principle, combination of parameter estimation self-tuning controller, is expected to design a high-performance low-power electromagnetic energy storage adaptive active suspension, active suspension so that by the theory into practical application of each technology across all disciplines and related development is closely related to computer technology, automatic control technology, fuzzy control, neural networks, advanced manufacturing technology, such as motion simulation for the suspension of further development of strong security, the development of suspension subject to the relevant requirements of the theory of higher so that a new understanding of humanity, and a higher level 。
69
黑龍江工程學(xué)院本科生畢業(yè)設(shè)計
汽車懸架的介紹
汽車懸架種類和工作原理
選取不同的標(biāo)準(zhǔn), 懸架有不同的分類方法根據(jù)車橋是否斷開, 可分為獨立懸架和非獨立懸架，所謂的非獨立懸架, 兩側(cè)的車輪由一根整體式車橋相連,車輪連同車橋一起通過彈性懸架與車架連接。特點是當(dāng)一側(cè)的車輪遇到路面沖擊而跳動時, 必然導(dǎo)致另一側(cè)車輪在汽車橫向平面內(nèi)擺動，獨立懸架是車橋做成斷開的, 每一側(cè)車輪可以單獨通過彈性懸架與車架連接，結(jié)構(gòu)較非獨立懸架復(fù)雜, 但兩側(cè)的車輪單獨跳動時互不影響, 可以提高乘坐的平順性，根據(jù)懸架的阻尼和剛度是否隨著行駛條件的變化而變化, 可分為被動懸架、半主動懸架、全主動懸架。半主動懸架還可以按阻尼級分為有級式和無級式兩類，雖然現(xiàn)代汽車的懸架種類繁多, 結(jié)構(gòu)差異較大,但一般由彈性元件、減振元件和導(dǎo)向構(gòu)件組成。汽車懸架的模型如圖工作原理是: 當(dāng)汽車輪胎受到?jīng)_擊時, 彈性元件對沖擊進(jìn)行緩沖, 防止對汽車構(gòu)件和人員造成損傷，但彈性件受到?jīng)_擊時會產(chǎn)生長時間持續(xù)的振動, 容易使駕駛員疲勞而發(fā)生車禍, 故減振元件必須快速衰減振動，當(dāng)車輪受到?jīng)_擊而跳動時, 應(yīng)使其運(yùn)動軌跡符合一定的要求, 否則會降低汽車的平順性和穩(wěn)定性，導(dǎo)向構(gòu)件在傳力的同時, 必須對方向進(jìn)行控制。
- 簧下質(zhì)量 - 車身質(zhì)量 、- 隔振彈簧 c- 阻尼器
u- 作動器 l- 輪胎
圖1 三種懸架的模型圖
麥弗遜獨立懸架的特點
麥弗遜懸架部分由下擺臂、轉(zhuǎn)向節(jié)總成（包括減振器下體、輪轂軸、制動底板等）、轉(zhuǎn)向橫拉桿、減振器上體、轉(zhuǎn)向器齒條、車輪總成、車身共7 個剛體組成。 減振器上
體用萬向節(jié)鉸A 與車身相連，轉(zhuǎn)向節(jié)總成與減振器上體用圓柱鉸B 約束，相對減振器上半部分可以進(jìn)行軸向移動和轉(zhuǎn)動；下擺臂一端通過轉(zhuǎn)動鉸F,G 與車身相連（其中一個為虛約束），可相對車身上下擺動，另一端通過球鉸E 與轉(zhuǎn)向節(jié)總成相接；轉(zhuǎn)向橫拉桿一端通過球鉸C 與轉(zhuǎn)向節(jié)總成相連，另一端通過萬向節(jié)鉸H 與轉(zhuǎn)向齒條相連；轉(zhuǎn)向齒條通過移動鉸I 與車相連，可相對車身左右移動；車輪總成和轉(zhuǎn)向節(jié)總成通過轉(zhuǎn)動鉸鏈D 相連，進(jìn)行運(yùn)動學(xué)分析時，車身與地面是固定在一起的[麥弗遜獨立懸架具有結(jié)構(gòu)簡單、非簧載質(zhì)量小、發(fā)動機(jī)及轉(zhuǎn)向系易于布置、適合于同多種形式的彈簧相匹配以及能實現(xiàn)車身高度的自動調(diào)節(jié)等優(yōu)點。但是,由于主銷軸線位置在減振器與車身連接鉸鏈中心和橫擺臂與轉(zhuǎn)向節(jié)連接鉸鏈中心的連線上,因此當(dāng)懸架在變形時,主銷軸線也隨之改變,前輪定位參數(shù)和輪距也都會相應(yīng)改變,且變化量可能很大。因此,如果懸架結(jié)構(gòu)設(shè)計不當(dāng),就會大大影響汽車產(chǎn)品的使用性能(如轉(zhuǎn)向沉重、擺振、輪胎偏磨、影響輪胎使用壽命等)
懸價的發(fā)展的歷史和現(xiàn)狀
完美是人類永恒的追求。在馬車出現(xiàn)的時候, 為了乘坐更舒適, 人類就開始對馬車的懸架——葉片彈簧進(jìn)行孜孜不倦的探索,在1776 年, 馬車用的葉片彈簧取得了專利, 并且一直使用到20 世紀(jì)30 年代, 葉片彈簧才逐漸被螺旋彈簧代替， 汽車誕生后,隨著對懸架研究的深入, 相繼出現(xiàn)了扭桿彈簧、氣體彈簧、橡膠彈簧、鋼板彈簧等彈性件，1934 年世界上出現(xiàn)了第一個由螺旋彈簧組成的被動懸架。 被動懸架的模型如圖1 (a) 所示被動懸架的參數(shù)根據(jù)經(jīng)驗或優(yōu)化設(shè)計的方法確定, 在行駛過程中保持不變，它是一系列路況的折中, 很難適應(yīng)各種復(fù)雜路況, 減振的效果較差，為了克服這種缺陷, 采用了非線性剛度彈簧和車身高度調(diào)節(jié)的方法, 雖然有一定成效, 但無法根除被動懸架的弊端。被動懸架主要應(yīng)用于中低檔轎車上, 現(xiàn)代轎車的前懸架一般采用帶有橫向穩(wěn)定桿的麥弗遜式懸架, 比如桑塔納、夏利、賽歐等車, 后懸架的選擇較多, 主要有復(fù)合式縱擺臂懸架和多連桿懸架，半主動懸架的研究工作開始于1973 年, 由D.A. Cro sby 和D. C. Karnopp 首先提出模型如1 (b).半主動懸架以改變懸架的阻尼為主, 一般較少考慮改變懸架的剛度。工作原理是: 根據(jù)簧上質(zhì)量相對車輪的速度響應(yīng)、加速度響應(yīng)等反饋信號, 按照一定的控制規(guī)律調(diào)節(jié)彈簧的阻尼力或者剛度，半主動懸架產(chǎn)生力的方式與被動懸架相似, 但其阻尼或剛度系數(shù)可根據(jù)運(yùn)行狀態(tài)調(diào)節(jié), 這和主動懸架極為相似，有級式半主動懸架是將阻尼分成幾級, 阻尼級由駕駛員根據(jù)“路感”選擇或由傳感器信號自動選擇，無級式半主動懸架根據(jù)汽車行駛的路面條件和行駛狀態(tài), 對懸架的阻尼在幾毫秒內(nèi)由最小到最大進(jìn)行無級調(diào)節(jié)。由于半主動懸架結(jié)構(gòu)簡單, 工作時不需要消耗車輛的動力, 而且可取得與主動懸架相近的性能,具有很好的發(fā)展前景[ 4 ]隨著道路交通的不斷發(fā)展, 汽車車速有了很大的提高, 被動懸架的缺陷逐漸成為提高汽車性能的瓶頸, 為此人們開發(fā)了能兼顧舒適和操縱穩(wěn)定的主動懸架。主動懸架的概念是1954 年美國通用汽車公司在懸架設(shè)計中率先提出的，主動懸架的模型如圖1 (c) 所示，它在被動懸架的基礎(chǔ)上, 增加可調(diào)節(jié)剛度和阻尼的控制裝置, 使汽車懸架在任何路面上保持最佳的運(yùn)行狀態(tài)?？刂蒲b置通常由測量系統(tǒng)、反饋控制系統(tǒng)、能源系統(tǒng)等組成。20 世紀(jì)80 年代, 世界各大著名的汽車公司和生產(chǎn)廠家競相研制開發(fā)這種懸架，豐田、洛特斯、沃爾沃、奔馳等在汽車上進(jìn)行了較為成功的試驗。裝置主動懸架的汽車, 即使在不良路面高速行駛時, 車身非常平穩(wěn), 輪胎的噪音小, 轉(zhuǎn)向和制動時車身保持水平，特點是乘坐非常舒服, 但結(jié)構(gòu)復(fù)雜、能耗高, 成本昂貴, 可靠性存在問題。由于種種原因, 我國的汽車絕大部分采用被動懸架，在半主動和主動懸架的研究方面起步晚, 與國外的差距大[5]。在西方發(fā)達(dá)國家, 半主動懸架在20 世紀(jì)80 年代后期趨于成熟, 福特公司和日產(chǎn)公司首先在轎車上應(yīng)用, 取得了較好的效果，主動懸架雖然提出早, 但由于控制復(fù)雜, 并且牽涉到許多學(xué)科, 一直很難有大的突破。進(jìn)入20 世紀(jì)90 年代, 僅應(yīng)用于排氣量大的豪華汽車, 未見國內(nèi)汽車產(chǎn)品采用此技術(shù)的報道, 只有北京理工大學(xué)和同濟(jì)大學(xué)等少數(shù)幾個單位對主動懸架展開研究。
懸架的發(fā)展趨勢
被動懸架是傳統(tǒng)的機(jī)械結(jié)構(gòu), 剛度和阻尼都是不可調(diào)的, 依照隨機(jī)振動理論, 它只能保證在特定的路況下達(dá)到較好效果，但它的理論成熟、結(jié)構(gòu)簡單、性能可靠, 成本相對低廉且不需額外能量, 因而應(yīng)用最為廣泛，在我國現(xiàn)階段, 仍然有較高的研究價值L被動懸架性能的研究主要集中在三個方面: ①通過對汽車進(jìn)行受力分析后, 建立數(shù)學(xué)模型, 然后再用計算機(jī)仿真技術(shù)或有限元法尋找懸架的最優(yōu)參數(shù); ②研究可變剛彈簧和可變阻尼的減振器, 使懸架在絕大部分路況上保持良好的運(yùn)行狀態(tài); ③研究導(dǎo)向機(jī)構(gòu), 使汽車懸架在滿足平順性的前提下, 穩(wěn)定性有大的提高L半主動懸架的研究集中在兩個方面: ①執(zhí)行策略的研究; ②執(zhí)行器的研究L阻尼可調(diào)減振器主要有兩種, 一種是通過改變節(jié)流孔的大小調(diào)節(jié)阻尼, 一種是通過改變減振液的粘性調(diào)節(jié)阻尼，節(jié)流孔的大小一般通過電磁閥或步進(jìn)電機(jī)進(jìn)行有級或無級的調(diào)節(jié), 這種方法成本較高, 結(jié)構(gòu)復(fù)雜，通過改變減振液的粘性來改變阻尼系數(shù), 具有結(jié)構(gòu)簡單、成本低、無噪音和沖擊等特點, 因此是目前發(fā)展的主要方向。在國外, 改變減振液粘性的方法主要有電流變液體和磁流變液體兩種。北京理工大學(xué)的章一鳴教授進(jìn)行了阻尼可調(diào)節(jié)半主動懸架的研究, 林野進(jìn)行了懸架自適應(yīng)調(diào)節(jié)的控制決策研究, 哈工大的陳卓如教授對車輛的自適應(yīng)控制方面進(jìn)行了研究，執(zhí)行策略的研究是通過確定性能指標(biāo), 然后進(jìn)行控制器的設(shè)定。目前, 模糊控制在這方面應(yīng)用較多。主動懸架研究也集中在兩個方面: ①可靠性; ②執(zhí)行器；由于主動懸架采用了大量的傳感器、單片機(jī)、輸出輸入電路和各種接口, 元器件的增加降低了懸架的可靠性, 所以加大元件的集成程度, 是一個不可逾越的階段。行器的研究主要是用電動器件代替液壓器件，氣動力系統(tǒng)中的直線伺服電機(jī)和永磁直流直線伺服電機(jī)具有較多的優(yōu)點, 今后將會取代液壓執(zhí)行機(jī)構(gòu)L運(yùn)用電磁蓄能原理, 結(jié)合參數(shù)估計自校正控制器, 可望設(shè)計出高性能低功耗的電磁蓄能式自適應(yīng)主動懸架, 使主動懸架由理論轉(zhuǎn)化為實際應(yīng)用，技術(shù)的每次跨越, 都和相關(guān)學(xué)科的發(fā)展密切相關(guān)，計算機(jī)技術(shù)、自動控制技術(shù)、模糊控制、神經(jīng)網(wǎng)絡(luò)、先進(jìn)制造技術(shù)、運(yùn)動仿真等為懸架的進(jìn)一步發(fā)展提供了有力的保障，懸架的發(fā)展也給相關(guān)學(xué)科提出更高的理論要求, 使人類的認(rèn)識邁向新的、更高的境界。
73