CN104181816B

CN104181816B - A kind of vehicle safety and the control method of smooth degree

Info

Publication number: CN104181816B
Application number: CN201410409542.4A
Authority: CN
Inventors: 王伟
Original assignee: Renmin University of China
Current assignee: Renmin University of China
Filing date: 2014-08-19
Publication date: 2016-11-30
Anticipated expiration: 2034-08-19

Abstract

The present invention relates to a control method for vehicle safety and smoothness. Aiming at the characteristics of the vehicle dynamics model and the uncertainty of the vehicle's own parameters and road conditions during operation, the separation method of generalized PID control is used to implement control, which includes: Divide the control input into the integral based on the displacement error, and the input part based on the displacement error, velocity error and acceleration error, introduce the form of variable dynamic adjustment based on the input part of the displacement error integral, and eliminate the uncertain components and external disturbances of the vehicle control system ;Aiming at the controllable ideal mode of the vehicle, select the form of the input part based on the displacement error, velocity error and acceleration error, and determine the coefficients of the displacement error, velocity error and acceleration error, so as to realize the stable control of the ideal mode constituting the system at the origin; Select design parameters to control the safety and ride comfort of the controlled vehicle. The invention can be widely used in the control of vehicle cruise control and unmanned driving.

Description

A control method for vehicle safety and ride comfort

技术领域technical field

本发明涉及一种车辆控制方法，特别是关于一种车辆安全性及平顺度的控制方法。The invention relates to a vehicle control method, in particular to a vehicle safety and ride comfort control method.

背景技术Background technique

随着人们对汽车行驶安全性与舒适性等性能要求的提高，各国对车辆智能驾驶及各种驾驶员辅助系统的研究也逐步深入。作为先进车辆控制安全系统(AVCSS)开发的一个重要方面，汽车自适应巡航控制(以下简称ACC，Adaptive Cruise Control)系统引起了业界的关注。汽车ACC系统是在传统的巡航控制技术基础上发展起来的，汽车ACC系统作为驾驶员辅助系统，其目的是为了在适当的交通工况下，部分地取代驾驶员，对车辆进行合理的纵向控制，以提高车辆的主动安全性与乘坐舒适性。它既保证车辆具有定速巡航的能力，又保证车辆具有应用车载传感器的信息自动调整车辆行驶速度的能力，从而保持本车与前行车辆的安全间距。由于汽车ACC系统对提高车辆主动安全性与乘坐舒适性的巨大潜力，因而得到了国内外研究人员越来越多的重视。此外，2014年5月份，谷歌联合创始人谢尔盖·布林(Sergey Brin)发布了谷歌最新的无人驾驶汽车原型。据相关报道，谷歌的无人驾驶车没有配备方向盘、油门、刹车、后视镜等部件，它是通过车联网系统，按照其输入或接收的地址来接送乘客。该车时速最高25英里(约合40公里)，车辆正中拥有一个液晶屏幕，用户通过屏幕可以完成所有指令。车辆无论在公路还是沙地上均运行得非常稳定。除了谷歌，其他像丰田、奥迪等大型汽车生产商也正在开发他们自己的无人驾驶汽车。可见，在车辆控制系统方面，保证安全和舒适的基础上，实现全自动的操控是当今车辆控制领域的一个热点问题，而其中的基础和关键问题仍旧是车辆的巡航控制问题。With the improvement of people's performance requirements for vehicle driving safety and comfort, the research on vehicle intelligent driving and various driver assistance systems has gradually deepened in various countries. As an important aspect of the development of Advanced Vehicle Control Safety System (AVCSS), Automotive Adaptive Cruise Control (hereinafter referred to as ACC, Adaptive Cruise Control) system has attracted the attention of the industry. The automotive ACC system is developed on the basis of traditional cruise control technology. As a driver assistance system, the automotive ACC system is designed to partially replace the driver under appropriate traffic conditions and to perform reasonable longitudinal control of the vehicle. , to improve the active safety and ride comfort of the vehicle. It not only ensures that the vehicle has the ability to cruise at a constant speed, but also ensures that the vehicle has the ability to automatically adjust the speed of the vehicle using the information from the on-board sensors, so as to maintain a safe distance between the vehicle and the vehicle ahead. Because of the great potential of the automotive ACC system to improve the active safety and ride comfort of the vehicle, more and more researchers at home and abroad have paid more and more attention to it. In addition, in May 2014, Google co-founder Sergey Brin (Sergey Brin) released Google's latest driverless car prototype. According to related reports, Google's self-driving car is not equipped with steering wheel, accelerator, brake, rearview mirror and other components. It uses the Internet of Vehicles system to pick up and drop off passengers according to the address it inputs or receives. The top speed of the car is 25 miles per hour (about 40 kilometers), and there is an LCD screen in the middle of the car, through which the user can complete all instructions. The vehicle is very stable whether on road or sand. In addition to Google, other major car manufacturers such as Toyota and Audi are also developing their own self-driving cars. It can be seen that in terms of vehicle control systems, on the basis of ensuring safety and comfort, realizing fully automatic control is a hot issue in the field of vehicle control today, and the basic and key issue is still the problem of vehicle cruise control.

目前，国内外对ACC系统的研究主要集中在车载传感器及其信息融合技术，以及ACC系统控制策略选取等软硬件技术上，其中如何选取控制策略是实现ACC系统功能及其实用化的关键。而如何应用传感器单元输入的信息来给出适当的系统输出并合理地控制车辆，以实现ACC目的的系统控制技术则是汽车ACC系统应进一步研究及应用的核心。ACC系统的控制技术主要包括车辆理想安全距离的确定，以及系统控制理论与方法的选取等。At present, the research on ACC system at home and abroad is mainly focused on the vehicle sensor and its information fusion technology, and the selection of ACC system control strategy and other software and hardware technologies. How to select the control strategy is the key to realize the function and practicality of the ACC system. How to use the information input by the sensor unit to give the appropriate system output and control the vehicle reasonably to achieve the purpose of ACC system control technology is the core of the further research and application of the automotive ACC system. The control technology of the ACC system mainly includes the determination of the ideal safe distance of the vehicle, and the selection of the system control theory and method.

ACC系统的控制目标是适当地控制车辆的速度，保持车辆间安全距离，提高车辆的乘坐舒适性与主动安全性。为实现这些控制目标，在确定理想的车辆安全距离后，需要选取系统的控制策略、并采用适宜的控制理论建立系统控制算法。目前，PID方法、最优控制理论、滑动模理论以及模糊或智能理论等都被应用于ACC系统控制技术的研究。韩国汉阳大学提出的ACC系统控制算法中，理想减速度的确定方法采用线性二次型(LQ)最优控制理论。其理论分析和仿真计算结果表明，该方法在考虑模型误差与系统控制执行器延迟的情况下仍可以较好地实现ACC系统的性能指标。在汽车ACC系统设计中，采用车辆距离误差与相对速度误差最小为性能指标的最优控制方法，也获得了较好的汽车乘坐的舒适性与车辆队列的稳定性。在ACC理论与方法的选取方面，滑动模控制理论也有一定应用。如美国PATH(Partners for Advanced Transit Highways)项目中车辆ACC的控制器设计方面，采用滑动模控制理论来确定理想加速度。德国斯图加特大学研究的ACC系统，采用非线性车辆系统状态空间线性化与滑动模控制理论相结合的控制方法确定车辆的理想加速度。模糊控制理论在ACC的控制器设计方面也有一定的应用，如美国密歇根大学提出的ACC的控制器采用典型的模糊控制算法，其模糊控制规则为前件的两个条件确定后件的一个行为。前件的两个条件分别为车辆距离和两车相对速度，输出则是加速踏板开度。除上述各种控制理论外，神经网络理论及模型匹配等方法也应用于建立ACC的控制算法。上述各种控制方法基本都可以满足ACC系统的控制目的，但各有其优缺点，实际设计中，往往基于系统需要强化的某些性能指标而选择适宜的控制理论与方法。The control goal of the ACC system is to properly control the speed of the vehicle, maintain a safe distance between vehicles, and improve the ride comfort and active safety of the vehicle. In order to achieve these control objectives, after determining the ideal vehicle safety distance, it is necessary to select a system control strategy and establish a system control algorithm using appropriate control theory. At present, PID method, optimal control theory, sliding mode theory and fuzzy or intelligent theory have all been applied to the research of ACC system control technology. In the ACC system control algorithm proposed by Hanyang University in South Korea, the method of determining the ideal deceleration adopts the linear quadratic (LQ) optimal control theory. Theoretical analysis and simulation calculation results show that this method can still achieve the performance index of ACC system well considering the model error and system control actuator delay. In the design of the automobile ACC system, the optimal control method with the minimum vehicle distance error and relative speed error is used as the performance index, and better car ride comfort and vehicle queue stability are also obtained. In the selection of ACC theory and method, the sliding mode control theory also has certain application. For example, in the controller design of vehicle ACC in the PATH (Partners for Advanced Transit Highways) project in the United States, the sliding mode control theory is used to determine the ideal acceleration. The ACC system studied by the University of Stuttgart in Germany uses a control method combining the state space linearization of the nonlinear vehicle system and the sliding mode control theory to determine the ideal acceleration of the vehicle. Fuzzy control theory also has a certain application in ACC controller design. For example, the ACC controller proposed by the University of Michigan adopts a typical fuzzy control algorithm, and its fuzzy control rule determines a behavior of the latter part for the two conditions of the former part. The two conditions of the front part are the vehicle distance and the relative speed of the two vehicles, and the output is the accelerator pedal opening. In addition to the various control theories mentioned above, methods such as neural network theory and model matching are also used to establish the control algorithm of ACC. The above-mentioned various control methods can basically meet the control purpose of the ACC system, but each has its own advantages and disadvantages. In actual design, the appropriate control theory and method are often selected based on certain performance indicators that the system needs to strengthen.

目前，国内外车辆ACC系统的研究还存在一些技术问题需要加以完善，主要包括：ACC的控制器软件算法对环境的适应性较差，往往是针对几种典型的行驶工况，而当行车环境发生变化时，算法的有效性有较大程度的降低；人工智能，尤其是神经网络理论与方法在ACC系统中的应用还有待于深入研究开发；系统性能的评价目前没有一个完善的体系，不能综合评价不同ACC系统的性能。从目前国内外ACC系统的研究应用情况来看，应该关注以下技术：多传感器信息融合技术，如车辆雷达测距传感器与计算机视觉信息的融合技术等；通讯技术，包括车内通讯、车辆间的通讯及车辆与控制中心的通讯等；ACC系统与其它车辆纵向控制系统的集成化技术，如ACC系统与车辆停走(S&G)系统，以及与车辆前向防撞、预警系统，及后向防撞、预警系统的集成等。根据上述分析，当前保证车辆的安全行驶的控制方法存在诸多问题：(1)对车辆运行环境(路况)的适应能力有待改进；(2)由于在车辆运行过程中还存在自身的不确定性，如承载量，自身的质量等，现有的控制方法难以适应；(3)原来的方法中很少考虑对车辆加速度的控制，而这正是保证行驶舒适性(平顺度)的重要环节。因此，深入研究ACC系统的控制理论与方法，开发高效、实用的车辆ACC产品，将是今后我国在该领域的研究方向。At present, there are still some technical problems that need to be improved in the research of vehicle ACC systems at home and abroad, mainly including: the ACC controller software algorithm has poor adaptability to the environment, and it is often aimed at several typical driving conditions. When there is a change, the effectiveness of the algorithm will be greatly reduced; the application of artificial intelligence, especially the theory and method of neural network in the ACC system still needs to be further researched and developed; there is no perfect system for system performance evaluation, and cannot Comprehensively evaluate the performance of different ACC systems. Judging from the current research and application of ACC systems at home and abroad, attention should be paid to the following technologies: multi-sensor information fusion technology, such as the fusion technology of vehicle radar ranging sensors and computer vision information; communication technology, including in-vehicle communication, inter-vehicle communication, etc. Communication and communication between the vehicle and the control center, etc.; the integration technology of the ACC system and other vehicle longitudinal control systems, such as the ACC system and the vehicle stop and go (S&G) system, as well as the vehicle's forward collision avoidance, early warning system, and rearward anti-collision Collision, early warning system integration, etc. According to the above analysis, there are many problems in the current control method to ensure the safe driving of vehicles: (1) the adaptability to the vehicle operating environment (road conditions) needs to be improved; Such as load capacity, self-quality, etc., the existing control methods are difficult to adapt; (3) The control of vehicle acceleration is rarely considered in the original method, and this is an important link to ensure driving comfort (smoothness). Therefore, in-depth research on the control theory and methods of ACC systems and the development of efficient and practical vehicle ACC products will be the research direction of our country in this field in the future.

发明内容Contents of the invention

针对上述问题，本发明的目的是提供一种关于车辆安全性及平顺度的控制方法，使得既使面对不同运载量或不同路况等情况，基于本发明给出的控制方法，车辆仍能够在保证安全的同时保证平稳行驶。In view of the above problems, the object of the present invention is to provide a control method for vehicle safety and ride comfort, so that even in the face of different loads or different road conditions, based on the control method provided by the present invention, the vehicle can still run smoothly. Ensure safety while ensuring smooth driving.

为实现上述目的，本发明采取以下技术方案：一种车辆安全性及平顺度的控制方法，其包括以下步骤：1)针对如下形式的具有普遍性的被控车辆系统：In order to achieve the above object, the present invention adopts the following technical solutions: a control method for vehicle safety and ride comfort, which includes the following steps: 1) for the general controlled vehicle system in the following form:

$\{\begin{matrix} {\overset{\cdot &Center Dot;}{x x}}_{11} ((t t)) = = {x x}_{22} ((t t)) \\ {\overset{\cdot &Center Dot;}{x x}}_{22} ((t t)) = = {x x}_{33} ((t t)) \\ {\overset{\cdot &Center Dot;}{x x}}_{33} ((t t)) = = b b [[{x x}_{22} ((t t)),, {x x}_{33} ((t t))]] + + a a [[{x x}_{22} ((t t))]] u u ((t t)) \\ y the y ((t t)) = = {x x}_{11} ((t t)) \end{matrix} - - - - - - ((11))$

式(1)中，x₁(t)、x₂(t)和x₃(t)分别表示被控车辆的位移、速度和加速度；u(t)表示发动机输入，即控制输入；且a[x₂(t)]和b[x₂(t),x₃(t)]分别具有如下形式：In formula (1), x ₁ (t), x ₂ (t) and x ₃ (t) represent the displacement, velocity and acceleration of the controlled vehicle respectively; u(t) represents the engine input, that is, the control input; and a[ x ₂ (t)] and b[x ₂ (t), x ₃ (t)] have the following forms respectively:

$a a [[{x x}_{22} ((t t))]] = = \frac{11}{m m τ τ (({x x}_{22} ((t t))))} - - - - - - ((22))$

$b b [[{x x}_{22} ((t t)),, {x x}_{33} ((t t))]] = = - - \frac{22 {K K}_{d d}}{m m} {x x}_{22} ((t t)) {x x}_{33} ((t t)) - - \frac{11}{τ τ (({x x}_{22} ((t t))))} [[{x x}_{33} ((t t)) + + \frac{{K K}_{d d}}{m m} {x x}_{22}^{22} ((t t)) + + \frac{{d d}_{m m}}{m m}]] - - - - - - ((33))$

式(2)和式(3)中，m表示被控车辆的质量，τ表示发动机的时间常数，K_d表示气动阻力系数，d_m表示被控车辆的机械阻力；假设控制的目标是让车辆的实际位移y(t)＝x₁(t)能跟踪上设定的位移y_r(t)，让车辆的实际速度能跟踪上设定的速度让车辆的实际加速度能跟踪上设定的加速度引入如下位移误差变量e₁(t)、速度误差变量e₂(t)和加速度误差变量e₃(t)：In formulas (2) and (3), m represents the mass of the controlled vehicle, τ represents the time constant of the engine, K _d represents the aerodynamic drag coefficient, and d _m represents the mechanical resistance of the controlled vehicle; it is assumed that the control goal is to make the vehicle The actual displacement y(t)=x ₁ (t) can track the set displacement y _r (t), so that the actual speed of the vehicle Can track the speed set on Let the actual acceleration of the vehicle Ability to track acceleration set on Introduce the following displacement error variable e ₁ (t), velocity error variable e ₂ (t) and acceleration error variable e ₃ (t):

$\{\begin{matrix} {e e}_{11} ((t t)) = = {x x}_{11} ((t t)) - - {y the y}_{r r} ((t t)) \\ {e e}_{22} ((t t)) = = {x x}_{22} ((t t)) - - {\overset{\cdot \cdot}{y the y}}_{r r} ((t t)) \\ {e e}_{33} ((t t)) = = {x x}_{33} ((t t)) - - {\overset{\cdot\cdot \cdot\cdot}{y the y}}_{r r} ((t t)) \end{matrix} - - - - - - ((44))$

根据式(1)和式(4)，则车辆的跟踪控制问题就转换为如下误差系统在原点(0,0,0)的稳定问题：According to formula (1) and formula (4), the tracking control problem of the vehicle is transformed into the stability problem of the error system at the origin (0,0,0) as follows:

$\{\begin{matrix} {\overset{\cdot &Center Dot;}{e e}}_{11} ((t t)) = = {e e}_{22} ((t t)) \\ {\overset{\cdot &Center Dot;}{e e}}_{22} ((t t)) = = {e e}_{33} ((t t)) \\ {\overset{\cdot \cdot}{e e}}_{33} ((t t)) = = b b (({e e}_{22} ((t t)) + + {\overset{\cdot \cdot}{y the y}}_{r r} ((t t)),, {e e}_{33} ((t t)) + + {\overset{\cdot\cdot \cdot\cdot}{y the y}}_{r r} ((t t)))) - - {\overset{\cdot\cdot\cdot \cdot\cdot\cdot}{y the y}}_{r r} ((t t)) + + a a (({e e}_{22} ((t t)) + + {\overset{\cdot \cdot}{y the y}}_{r r} ((t t)))) u u ((t t)) \\ y the y ((t t)) = = {x x}_{11} ((t t)) \end{matrix} - - - - - - ((55))$

基于a[x₂(t)]作为车辆控制输入的增益满足约束条件：其中a_m和a_M均为已知常数，则将式(5)写为：The gain based on a[x ₂ (t)] as the vehicle control input satisfies the constraints: Where a _m and a _M are known constants, then formula (5) can be written as:

$\{\begin{matrix} {\overset{\cdot \cdot}{e e}}_{11} ((t t)) = = {e e}_{22} ((t t)) \\ {\overset{\cdot \cdot}{e e}}_{22} ((t t)) = = {e e}_{33} ((t t)) \\ {\overset{\cdot \cdot}{e e}}_{33} ((t t)) = = b b (({e e}_{22} ((t t)) + + {\overset{\cdot \cdot}{y the y}}_{r r} ((t t)),, {e e}_{33} ((t t)) + + {\overset{\cdot\cdot \cdot\cdot}{y the y}}_{r r} ((t t)))) - - {\overset{\cdot\cdot\cdot \cdot\cdot\cdot}{y the y}}_{r r} ((t t)) + + a a (({e e}_{22} ((t t)) + + {\overset{\cdot &Center Dot;}{y the y}}_{r r} ((t t)))) u u ((t t)) - - {a a}_{m m} u u ((t t)) + + {a a}_{m m} u u ((t t)) \\ y the y ((t t)) = = {x x}_{11} ((t t)) \end{matrix} - - - - - - ((66))$

在式(6)中，将看作式(6)表示的误差系统的总扰动，记为：In formula (6), the As the total disturbance of the error system represented by formula (6), it is recorded as:

$\overset{~ ~}{d d} ((t t)) = = b b (({e e}_{22} ((t t)) + + {\overset{\cdot &Center Dot;}{y the y}}_{r r} ((t t)),, {e e}_{33} ((t t)) + + {\overset{\cdot\cdot \cdot\cdot}{y the y}}_{r r} ((t t)))) - - {\overset{\cdot\cdot\cdot \cdot\cdot\cdot}{y the y}}_{r r} ((t t)) + + a a (({e e}_{22} ((t t)) + + {\overset{\cdot &Center Dot;}{y the y}}_{r r} ((t t)))) u u ((t t)) - - {a a}_{m m} u u ((t t));;$

将控制输入u(t)分为基于位移误差的积分的输入部分u_I(t)，以及基于位移的误差、速度的误差和加速度的误差的输入部分u_GPD(t)，即整个控制输入分成如下两个部分：The control input u(t) is divided into the input part u _I (t) based on the integral of the displacement error, and the input part u _GPD (t) based on the error of the displacement, the error of the velocity and the error of the acceleration, that is, the whole control input is divided into There are two parts as follows:

u(t)＝u_I(t)+u_GPD(t) (7)u(t)＝ _uI (t)+ _uGPD (t) (7)

将式(7)代入式(6)中，则式(6)表示的误差系统简化为：Substituting formula (7) into formula (6), the error system represented by formula (6) is simplified as:

$\{\begin{matrix} {\overset{\cdot \cdot}{e e}}_{11} ((t t)) = = {e e}_{22} ((t t)) \\ {\overset{\cdot \cdot}{e e}}_{22} ((t t)) = = {e e}_{33} ((t t)) \\ {\overset{\cdot &Center Dot;}{e e}}_{33} ((t t)) = = \overset{~ ~}{d d} ((t t)) + + {a a}_{m m} (({u u}_{I I} ((t t)) + + {u u}_{G G P P D D.} ((t t)))) \\ y the y ((t t)) = = {x x}_{11} ((t t)) \end{matrix} - - - - - - ((88))$

2)通过引入一变量μ(t)来动态调节基于位移误差的积分的输入部分u_I(t)的形式，迫使车辆的运动按照理想的可控模式来变化，其具体过程为：①引入如下形式的变量σ(t)：2) By introducing a variable μ(t) to dynamically adjust the form of the input part u _I (t) based on the integral of the displacement error, forcing the movement of the vehicle to change according to the ideal controllable mode, the specific process is: ①Introduce as follows Variable σ(t) of the form:

$σ σ ((t t)) = = \overset{~ ~}{d d} ((t t)) + + {a a}_{m m} {u u}_{I I} ((t t)) - - - - - - ((99))$

②引入变量μ(t)，其由如下动态方程来确定：②Introduce the variable μ(t), which is determined by the following dynamic equation:

$\{\begin{matrix} \overset{\cdot &Center Dot;}{μ μ} ((t t)) = = \{\begin{matrix} - - γ γ s the s i i g g n no ((σ σ ((t t)))),, & | | μ μ ((t t)) | | \leq \leq 11 \\ - - ω ω μ μ ((t t)),, & | | μ μ ((t t)) | | > > 11 \end{matrix} \\ μ μ ((00)) = = s the s i i g g n no ((σ σ ((00)))) \end{matrix} - - - - - - ((1010))$

式(10)中，ω为设计参数，ω＞0；γ表示设计参数，其根据被控车辆的特征进行选取，取正数；sign表示符号函数；③用变量μ(t)来调节基于位移误差的积分的输入部分u_I(t)的形式，基于位移误差的积分的输入部分u_I(t)与变量μ(t)之间的关系式取为：In formula (10), ω is the design parameter, ω>0; γ represents the design parameter, which is selected according to the characteristics of the controlled vehicle, and takes a positive number; sign represents the sign function; ③ use the variable μ(t) to adjust the displacement based on In the form of the input part u _{I (t) of the integral of the error, the relationship between the input part u I} ₍ t) of the integral of the displacement error and the variable μ (t) is taken as:

${u u}_{I I} ((t t)) = = {k k}_{00} μ μ ((t t)) m m i i n no (({&Integral; &Integral;}_{{t t}_{00}}^{t t} | | e e ((s the s)) | | d d s the s,, M m)) - - - - - - ((1111))$

式(11)中，k₀和M均表示设计参数，表示取最小值运算，s表示积分变量；设计参数γ、k₀和M需满足如下条件：In formula (11), k ₀ and M both represent design parameters, Indicates the operation of taking the minimum value, s indicates the integral variable; the design parameters γ, k ₀ and M need to meet the following conditions:

${k k}_{00} γ γ M m &GreaterEqual; &Greater Equal; \underset{t t &GreaterEqual; &Greater Equal; {t t}_{00}}{s the s u u p p} | | \frac{d d}{d d t t} [[\overset{~ ~}{d d} ((t t))]] | | - - - - - - ((1212))$

式(12)中，sup表示取上确界的运算,表示总扰动的广义导数；④通过选取设计参数ω、γ、k₀和M，保证在有限时间内等式σ(t)＝0成立；3)选取基于位移的误差、速度的误差和加速度的误差的输入部分u_GPD(t)的形式，并确定基于位移的误差、速度的误差和加速度的误差的输入部分u_GPD(t)中对应项的系数，其具体过程为：将式(9)代入式(8)中，得到In formula (12), sup represents the operation of taking the supremum, represents the total disturbance The generalized derivative of ; ④ By selecting the design parameters ω, γ, k ₀ and M, the equation σ(t) = 0 is guaranteed to hold in a finite time; 3) Select the input based on the error of displacement, error of velocity and error of acceleration Part u _GPD (t), and determine the coefficients of the corresponding items in the input part u _GPD (t) based on the displacement error, velocity error and acceleration error. The specific process is: Substitute Equation (9) into Equation ( 8), get

$\{\begin{matrix} {\overset{\cdot \cdot}{e e}}_{11} ((t t)) = = {e e}_{22} ((t t)) \\ {\overset{\cdot \cdot}{e e}}_{22} ((t t)) = = {e e}_{33} ((t t)) \\ {\overset{\cdot &Center Dot;}{e e}}_{33} ((t t)) = = σ σ ((t t)) + + {a a}_{m m} {u u}_{G G P P D D.} ((t t)) \\ y the y ((t t)) = = {x x}_{11} ((t t)) \end{matrix} - - - - - - ((1313))$

由于在步骤2)中对基于位移误差积分的输入部分u_I(t)中引入了变量μ(t)，并选取了设计参数ω、γ、k₀和M使得σ(t)＝0，则由式(13)得到：Since the variable μ(t) is introduced into the input part u _I (t) based on displacement error integration in step 2), and the design parameters ω, γ, k ₀ and M are selected so that σ(t)=0, then From formula (13) get:

$\{\begin{matrix} {\overset{\cdot &Center Dot;}{e e}}_{11} ((t t)) = = {e e}_{22} ((t t)) \\ {\overset{\cdot &Center Dot;}{e e}}_{22} ((t t)) = = {e e}_{33} ((t t)) \\ {\overset{\cdot &Center Dot;}{e e}}_{33} ((t t)) = = {a a}_{m m} {u u}_{G G P P D D.} ((t t)) \\ y the y ((t t)) = = {x x}_{11} ((t t)) \end{matrix} - - - - - - ((1414))$

由式(14)可知，基于位移的误差、速度的误差和加速度的误差的输入部分u_GPD(t)只与被控车辆的状态有关，根据被控车辆的状态，选取u_GPD(t)的形式，可直接选取使式(14)表示的动力系统在原点(0,0,0)稳定的系数作为位移误差项的系数k₁，速度误差项的系数k₂和加速度误差项的系数k₃；4)根据步骤2)确定的设计参数γ、k₀和M，以及步骤3)确定的位移误差项的系数k₁、速度误差项的系数k₂和加速度误差项的系数k₃，确定被控车辆的控制系统，亦即通过分离实现方式对被控车辆的位移、速度和加速度进行控制，达到对被控车辆安全性和平顺度的控制目的。From formula (14), it can be seen that the input part u _GPD (t) based on the displacement error, velocity error and acceleration error is only related to the state of the controlled vehicle. According to the state of the controlled vehicle, the value of u _GPD (t) form, the coefficient k 1 of the displacement error term, the coefficient k ₂ of the velocity error term and the coefficient k ₃ of the acceleration error term can be directly selected to make the dynamical system represented by formula (14) stable at the origin (0,0,0 ₎ . ; 4) According to the design parameters γ, k ₀ and M determined in step 2), and the coefficient k 1 of the displacement error term, the coefficient k ₂ of the velocity error term and the coefficient k ₃ of the acceleration error term determined in step ₃ ), it is determined to be The control system of the controlled vehicle, that is, to control the displacement, speed and acceleration of the controlled vehicle by means of separation, so as to achieve the purpose of controlling the safety and smoothness of the controlled vehicle.

所述步骤2)中，为简化变量μ(t)对基于位移误差的积分的输入部分u_I(t)的形式的调节，基于位移误差的积分的输入部分u_I(t)与变量μ(t)之间的关系式直接取为：In said step 2), in order to simplify the adjustment of the variable μ(t) to the form of the input part u _I (t) based on the integral of the displacement error, the input part u _I (t) based on the integral of the displacement error is related to the variable μ ( The relationship between t) is directly taken as:

u_I(t)＝k₀μ(t)M (15)u _I (t) = k ₀ μ(t)M (15)

设计参数γ、k₀和M需满足如下条件：The design parameters γ, k ₀ and M need to meet the following conditions:

${k k}_{00} γ γ M m &GreaterEqual; &Greater Equal; \underset{t t &GreaterEqual; &Greater Equal; {t t}_{00}}{s the s u u p p} | | \frac{d d}{d d t t} [[\overset{~ ~}{d d} ((t t))]] | | - - - - - - ((1616))$

式(16)中，sup表示取上确界的运算,表示总扰动的广义导数。In formula (16), sup represents the operation of taking the supremum, represents the total disturbance The generalized derivative of .

所述步骤3)中，基于位移的误差、速度的误差和加速度的误差的输入部分u_GPD(t)采用线性形式、非线性形式或最优化形式。In the step 3), the input part u _GPD (t) based on the displacement error, the velocity error and the acceleration error adopts a linear form, a nonlinear form or an optimized form.

所述步骤3)中，基于位移的误差、速度的误差和加速度的误差的输入部分u_GPD(t)采用以下线性形式：In said step 3), the input part u _GPD (t) based on the error of displacement, the error of velocity and the error of acceleration adopts the following linear form:

u_GPD(t)＝k₁e₁(t)+k₂e₂(t)+k₃e₃(t) (17)u _GPD (t) = k ₁ e ₁ (t) + k ₂ e ₂ (t) + k ₃ e ₃ (t) (17)

或以下非线性形式：or the following non-linear form:

u_GPD(t)＝k₁|e₁(t)|^αsign(e₁(t))+k₂|e₂(t)|^αsign(e₂(t))+k₃|e₃(t)|^αsign(e₃(t))(18)u _GPD (t)＝k ₁ |e ₁ (t)| ^α sign(e ₁ (t))+k ₂ |e ₂ (t)| ^α sign(e ₂ (t))+k ₃ |e ₃ ( t)| ^α sign(e ₃ (t))(18)

式(17)和式(18)中，k₁、k₂和k₃分别表示基于位移的误差、速度的误差和加速度的误差的输入部分u_GPD(t)中位移误差项的系数、速度误差项的系数和加速度误差项的系数，α表示非线性的指数，0＜α≤1。In Equation (17) and _Equation (18), k ₁ , k ₂ and k ₃ respectively denote the coefficients of the displacement error term, velocity error The coefficient of the term and the coefficient of the acceleration error term, α represents the nonlinear index, 0<α≤1.

所述步骤3)中，为保证控制输入的连续性，将式(18)中的符号函数用一种扩展形式的饱和函数来代替，即：In the step 3), in order to ensure the continuity of the control input, the sign function in formula (18) is replaced by an extended form of saturation function, namely:

u_GPD(t)＝k₁fal(e₁(t),α,δ)+k₂fal(e₂(t),α,δ)+k₃fal(e₃(t),α,δ) (19)u _GPD (t)＝k ₁ fal(e ₁ (t),α,δ)+k ₂ fal(e ₂ (t),α,δ)+k ₃ fal(e ₃ (t),α,δ) (19)

其中，in,

$f f a a l l ((x x,, α α,, δ δ)) = = \{\begin{matrix} {xδ xδ}^{α α - - 11},, & | | x x | | \leq \leq δ δ \\ | | x x {| |}^{α α} s the s i i g g n no ((x x)),, & | | x x | | > > δ δ \end{matrix} - - - - - - ((2020))$

式(20)中，x为自变量，根据需要分别取为位移误差变量e₁(t)、速度误差变量e₂(t)和加速度误差变量e₃(t)，α和δ均为设计参数，0＜α≤1,0＜δ≤0.1。In formula (20), x is an independent variable, which can be taken as displacement error variable e ₁ (t), velocity error variable e ₂ (t) and acceleration error variable e ₃ (t) according to needs, and α and δ are design parameters , 0<α≤1, 0<δ≤0.1.

当被控车辆的实际测量信号只有位移信号y(t)，或实际测量的位移信号y(t)中含有噪声时，对被控车辆的位移、速度和加速度进行控制，其具体包括以下步骤：1)利用两级跟踪-微分器对实际测量的位移信号y(t)进行预处理，其具体包括：首先，采用第一级跟踪-微分器对实际测量的位移信号y(t)进行处理，得到实测位移的估计信号及实测位移的导数信号，并分别仍记为y(t)和其次，将该位移的导数信号看作是被控车辆的速度信号，对得到的速度信号利用第二级跟踪-微分器，将得到速度的导数信号仍记为并将其看作是被控车辆的加速度信号；最后，用经两级跟踪-微分器处理后的结果，即实际测量的位移信号的估计信号以及实际测量的位移信号的一阶导数、二阶导数，分别代替被控车辆实际的位移、速度和加速度信号；2)采用与步骤1)～4)相同的方法对被控车辆的位移、速度和加速度进行控制。When the actual measurement signal of the controlled vehicle is only the displacement signal y(t), or when the actually measured displacement signal y(t) contains noise, the displacement, velocity and acceleration of the controlled vehicle are controlled, which specifically includes the following steps: 1) Preprocessing the actual measured displacement signal y(t) by using a two-stage tracking-differentiator, which specifically includes: first, using the first-stage tracking-differentiator to process the actually measured displacement signal y(t), The estimated signal of the measured displacement and the derivative signal of the measured displacement are obtained, and they are still recorded as y(t) and Second, the derivative signal of the displacement As the speed signal of the controlled vehicle, use the second-stage tracking-differentiator to obtain the speed signal, and still record the derivative signal of the speed as And regard it as the acceleration signal of the controlled vehicle; finally, use the result processed by the two-stage tracking-differentiator, that is, the estimated signal of the actual measured displacement signal and the first derivative and second order derivative of the actual measured displacement signal Derivatives respectively replace the actual displacement, velocity and acceleration signals of the controlled vehicle; 2) Use the same method as steps 1) to 4) to control the displacement, velocity and acceleration of the controlled vehicle.

本发明由于采取以上技术方案，其具有以下优点：1、本发明由于将控制输入分为基于位移误差的积分的输入部分，以及基于位移的误差、速度的误差和加速度的误差的输入部分，一方面，通过选择车辆理想运动模式所产生的变量来动态调节基于位移误差的积分的输入部分的形式，以此排除不确定成分或路况及环境的扰动对车辆控制的影响；另一方面，通过选取基于位移的误差、速度的误差和加速度的误差的输入部分的形式，以及位移误差项的系数、速度误差项的系数和加速度误差项的系数，实现对车辆理想运动模式的控制。通过上述两个方面的结合，即以一种广义PID控制的分离实现方法，实现对被控车辆的位移、速度和加速度的控制，本发明既能满足车辆在不同载重量或不同路况下的安全行驶要求，又不需要对被控车辆不确定性和运行环境状况的实时估计，因此省去了对不确定性和扰动进行实时辨识的要求，简化了控制器的结构。2、在现有车辆控制中，通常采用基于PID控制或智能控制的方法，其中往往需要通过“查表”的技术来确定设计参数；本发明则将上述控制技术上升为一种控制理论，使得本发明的控制方法更科学、应用范围更宽，且适应能力更强，同时在相应的位移的误差、速度的误差和加速度的误差所对应输入部分的选取方面，可以充分利用现代控制理论的成果，因而本发明架起了控制理论与实际应用之间的桥梁。3、本发明由于以广义PID控制的分离实现方法实施控制，且基于位移的误差、速度的误差和加速度的误差的输入部分可以采用线性形式、非线性形式或最优化形式等，因此采用本发明能够使得调节过程变得简单、且便于工程实现。4、本发明既可以保证车辆的安全性，又可以对车辆的加速度进行有效地控制，特别是避免车辆行驶中过大的加、减速度所引起的颠簸，以保证乘客的舒适度，减少晕车者的不适，提升车辆控制的品质。基于以上优点，本发明可以广泛应用于车辆的巡航控制、无人驾驶等领域。The present invention has the following advantages due to the adoption of the above technical scheme: 1. The present invention divides the control input into an input part based on the integral of the displacement error, and an input part based on the error of the displacement, the error of the velocity and the error of the acceleration. On the one hand, the form of the input part of the integral based on the displacement error is dynamically adjusted by selecting the variables generated by the vehicle’s ideal motion mode, so as to eliminate the influence of uncertain components or road conditions and environmental disturbances on the vehicle control; on the other hand, by selecting Based on the form of the input part of the displacement error, the velocity error and the acceleration error, and the coefficients of the displacement error item, the velocity error item and the acceleration error item, the control of the ideal motion mode of the vehicle is realized. Through the combination of the above two aspects, that is, a method of separating the generalized PID control to realize the control of the displacement, speed and acceleration of the controlled vehicle, the present invention can meet the safety requirements of the vehicle under different loads or different road conditions. It does not require real-time estimation of the uncertainty of the controlled vehicle and the operating environment, so the requirement for real-time identification of uncertainties and disturbances is omitted, and the structure of the controller is simplified. 2. In the existing vehicle control, the method based on PID control or intelligent control is usually adopted, wherein the technology of "look-up table" is often required to determine the design parameters; the present invention raises the above-mentioned control technology to a kind of control theory, so that The control method of the present invention is more scientific, has a wider application range, and has stronger adaptability. At the same time, in the selection of the input part corresponding to the error of the corresponding displacement, the error of the speed and the error of the acceleration, the achievements of modern control theory can be fully utilized. , thus the present invention builds a bridge between control theory and practical application. 3. The present invention implements control due to the separation of generalized PID control, and the input part based on the error of displacement, the error of velocity and the error of acceleration can adopt linear form, nonlinear form or optimal form etc., therefore adopt the present invention It can make the adjustment process simple and convenient for engineering realization. 4. The present invention can not only ensure the safety of the vehicle, but also effectively control the acceleration of the vehicle, especially avoid the bumps caused by excessive acceleration and deceleration during the driving of the vehicle, so as to ensure the comfort of passengers and reduce motion sickness The discomfort of the operator can improve the quality of vehicle control. Based on the above advantages, the present invention can be widely used in the fields of vehicle cruise control, unmanned driving and the like.

附图说明Description of drawings

图1是采用基于分离实现方法得到的广义PID控制器所对应的车辆控制系统的结构示意图；Fig. 1 is a structural schematic diagram of a vehicle control system corresponding to a generalized PID controller obtained based on a separation implementation method;

图2是当被控车辆的实际输出只有位移信号，或实际测量的位移信号中包含噪声的情况下，采用基于分离实现方法得到的广义PID控制器所对应的车辆控制系统的结构示意图。Fig. 2 is a structural schematic diagram of the vehicle control system corresponding to the generalized PID controller obtained based on the separation implementation method when the actual output of the controlled vehicle is only the displacement signal, or the actual measured displacement signal contains noise.

具体实施方式detailed description

下面结合附图和实施例对本发明进行详细的描述。The present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.

本发明采用基于分离实现方法得到的广义PID控制器对车辆的安全性及平顺度的控制，其基本原理为：首先，将被控车辆看作由“不确定部分”和“理想部分”构成，其中，不确定部分包括“车辆本身质量的变化”和“外来扰动”，其中“外来扰动”包括路况变化和环境变化等。其次，构建广义的PID控制形式，即利用车辆实际位移与设定位移的误差的积分、比例、导数和二阶导数的组合形式作为控制输入。换句话说，以实际位移与设定位移的误差(以下简称：位移的误差)的积分、比例，以及实际速度与设定速度的误差(以下简称：速度的误差)、实际加速度和设定加速度的误差(以下简称：加速度的误差)来构建控制变量。再次，针对车辆运行中的“不确定部分”和“外来扰动”，利用位移误差的积分反馈，通过引入动态环节来调节该反馈部分的形式，以此排除“不确定部分”和“外来扰动”的影响。同时，利用位移的误差、速度的误差和加速度的误差所确定的输入部分对车辆的“理想部分”进行控制。The present invention adopts the generalized PID controller obtained based on the separation realization method to control the safety and smoothness of the vehicle. The basic principle is as follows: firstly, the controlled vehicle is regarded as composed of an "uncertain part" and an "ideal part", Among them, the uncertain part includes "changes in the quality of the vehicle itself" and "external disturbances", where "external disturbances" include changes in road conditions and environmental changes. Secondly, construct a generalized PID control form, that is, use the combination of the integral, proportion, derivative and second-order derivative of the error between the actual displacement of the vehicle and the set displacement as the control input. In other words, the integral and ratio of the error between the actual displacement and the set displacement (hereinafter referred to as: displacement error), as well as the error between the actual speed and the set speed (hereinafter referred to as: speed error), the actual acceleration and the set acceleration The error (hereinafter referred to as: the error of acceleration) is used to construct the control variable. Thirdly, for the "uncertain part" and "external disturbance" in the operation of the vehicle, the integral feedback of the displacement error is used to adjust the form of the feedback part by introducing a dynamic link, so as to eliminate the "uncertain part" and "external disturbance" Impact. At the same time, the "ideal part" of the vehicle is controlled using the input part determined by the error of the displacement, the error of the velocity and the error of the acceleration.

假设对被控车辆进行控制的目的是选择控制输入u(t)，使被控车辆的实际输出能够跟踪上设定的参考输入。其中，被控车辆的实际输出包括实际测量的车辆运行的位移、速度和加速度等，分别记为y(t),设定的参考输入包括对车辆所设定的位移、速度和加速度等，分别记为y_r(t), Assume that the purpose of controlling the controlled vehicle is to select the control input u(t), so that the actual output of the controlled vehicle can track the reference input set above. Among them, the actual output of the controlled vehicle includes the actual measured displacement, velocity and acceleration of the vehicle, which are respectively denoted as y(t), The set reference input includes the displacement, velocity and acceleration set for the vehicle, which are respectively denoted as y _r (t),

如图1所示，本发明车辆安全性及平顺度的控制方法包括以下步骤：As shown in Figure 1, the control method of vehicle safety and ride comfort of the present invention comprises the following steps:

1)针对如下形式的具有普遍性的被控车辆系统：1) Aiming at the generalized charged vehicle system of the following forms:

$\{\begin{matrix} {\overset{\cdot \cdot}{x x}}_{11} ((t t)) = = {x x}_{22} ((t t)) \\ {\overset{\cdot \cdot}{x x}}_{22} ((t t)) = = {x x}_{33} ((t t)) \\ {\overset{\cdot \cdot}{x x}}_{33} ((t t)) = = b b [[{x x}_{22} ((t t)),, {x x}_{33} ((t t))]] + + a a [[{x x}_{22} ((t t))]] u u ((t t)) \\ y the y ((t t)) = = {x x}_{11} ((t t)) \end{matrix} - - - - - - ((11))$

式(2)和式(3)中，m表示被控车辆的质量，τ表示发动机的时间常数，K_d表示气动阻力系数，d_m表示被控车辆的机械阻力。由于a[x₂(t)]和b[x₂(t),x₃(t)]中均包含不确定成分，控制输入的增益a[x₂(t)]是不为零的，因此假设a[x₂(t)]满足如下约束：In formulas (2) and (3), m represents the mass of the controlled vehicle, τ represents the time constant of the engine, K _d represents the aerodynamic drag coefficient, and d _m represents the mechanical resistance of the controlled vehicle. Since both a[x ₂ (t)] and b[x ₂ (t), x ₃ (t)] contain uncertain components, the gain a[x ₂ (t)] of the control input is not zero, so Suppose a[x ₂ (t)] satisfies the following constraints:

$00 < < {a a}_{m m} \leq \leq a a [[{x x}_{22} ((t t))]] = = \frac{11}{m m τ τ (({x x}_{22} ((t t))))} \leq \leq {a a}_{M m} - - - - - - ((44))$

式(4)中，a_m和a_M均为已知常数。In formula (4), a _m and a _M are known constants.

假设控制的目标是让车辆的实际位移y(t)＝x₁(t)能跟踪上设定的位移y_r(t)，让车辆的实际速度能跟踪上设定的速度让车辆的实际加速度能跟踪上设定的加速度引入如下位移误差变量e₁(t)、速度误差变量e₂(t)和加速度误差变量e₃(t)：Assume that the goal of control is to make the actual displacement of the vehicle y(t)=x ₁ (t) track the set displacement y _r (t), so that the actual speed of the vehicle Can track the speed set on Let the actual acceleration of the vehicle Ability to track acceleration set on Introduce the following displacement error variable e ₁ (t), velocity error variable e ₂ (t) and acceleration error variable e ₃ (t):

$\{\begin{matrix} {e e}_{11} ((t t)) = = {x x}_{11} ((t t)) - - {y the y}_{r r} ((t t)) \\ {e e}_{22} ((t t)) = = {x x}_{22} ((t t)) - - {\overset{\cdot &Center Dot;}{y the y}}_{r r} ((t t)) \\ {e e}_{33} ((t t)) = = {x x}_{33} ((t t)) - - {\overset{\cdot\cdot \cdot\cdot}{y the y}}_{r r} ((t t)) \end{matrix} - - - - - - ((55))$

根据式(1)和式(5)，则车辆的跟踪控制问题就转换为如下误差系统在原点(0,0,0)的稳定问题：According to formula (1) and formula (5), the tracking control problem of the vehicle is transformed into the stability problem of the error system at the origin (0,0,0) as follows:

$\{\begin{matrix} {\overset{\cdot &Center Dot;}{e e}}_{11} ((t t)) = = {e e}_{22} ((t t)) \\ {\overset{\cdot &Center Dot;}{e e}}_{22} ((t t)) = = {e e}_{33} ((t t)) \\ {\overset{\cdot &Center Dot;}{e e}}_{33} ((t t)) = = b b (({e e}_{22} ((t t)) + + {\overset{\cdot &Center Dot;}{y the y}}_{r r} ((t t)),, {e e}_{33} ((t t)) + + {\overset{\cdot\cdot \cdot\cdot}{y the y}}_{r r} ((t t)))) - - {\overset{\cdot\cdot\cdot \cdot\cdot\cdot}{y the y}}_{r r} ((t t)) + + a a (({e e}_{22} ((t t)) + + {\overset{\cdot &Center Dot;}{y the y}}_{r r} ((t t)))) u u ((t t)) \\ y the y ((t t)) = = {x x}_{11} ((t t)) \end{matrix} - - - - - - ((66))$

同时由于a[x₂(t)]的不确定性，根据式(4)可以将式(6)写成如下形式：At the same time, due to the uncertainty of a[x ₂ (t)], according to formula (4), formula (6) can be written as follows:

$\{\begin{matrix} {\overset{\cdot &Center Dot;}{e e}}_{11} ((t t)) = = {e e}_{22} ((t t)) \\ {\overset{\cdot &Center Dot;}{e e}}_{22} ((t t)) = = {e e}_{33} ((t t)) \\ {\overset{\cdot &Center Dot;}{e e}}_{33} ((t t)) = = b b (({e e}_{22} ((t t)) + + {\overset{\cdot &Center Dot;}{y the y}}_{r r} ((t t)),, {e e}_{33} ((t t)) + + {\overset{\cdot\cdot \cdot\cdot}{y the y}}_{r r} ((t t)))) - - {\overset{\cdot\cdot\cdot \cdot\cdot\cdot}{y the y}}_{r r} ((t t)) + + a a (({e e}_{22} ((t t)) + + {\overset{\cdot &Center Dot;}{y the y}}_{r r} ((t t)))) u u ((t t)) - - {a a}_{m m} u u ((t t)) + + {a a}_{m m} u u ((t t)) \\ y the y ((t t)) = = {x x}_{11} ((t t)) \end{matrix} - - - - - - ((77))$

在式(7)中，将看作式(7)表示的误差系统的总扰动，记为：In formula (7), the As the total disturbance of the error system represented by formula (7), it is recorded as:

$\overset{~ ~}{d d} ((t t)) = = b b (({e e}_{22} ((t t)) + + {\overset{\cdot &Center Dot;}{y the y}}_{r r} ((t t)),, {e e}_{33} ((t t)) + + {\overset{\cdot\cdot \cdot\cdot}{y the y}}_{r r} ((t t)))) - - {\overset{\cdot\cdot\cdot \cdot\cdot\cdot}{y the y}}_{r r} ((t t)) + + a a (({e e}_{22} ((t t)) + + {\overset{\cdot &Center Dot;}{y the y}}_{r r} ((t t)))) u u ((t t)) - - {a a}_{m m} u u ((t t)) . .$

为了利用分离实现方式对车辆进行控制，将控制输入u(t)分为基于位移误差的积分的输入部分u_I(t)，以及基于位移的误差、速度的误差和加速度的误差的输入部分u_GPD(t)，其中，u_GPD(t)是一种广义的位移误差的比例和导数组合。即整个广义PID控制输入表示为：In order to control the vehicle using a split implementation, the control input u(t) is divided into an input part u _I (t) based on the integral of the displacement error, and an input part u based on the error of the displacement, the error of the velocity and the error of the acceleration _GPD (t), where u _GPD (t) is a combination of the proportional and derivative of a generalized displacement error. That is, the entire generalized PID control input is expressed as:

u(t)＝u_I(t)+u_GPD(t) (8)u(t)＝ _uI (t)+ _uGPD (t) (8)

将式(8)代入式(7)中，则式(7)可以表示为：Substituting formula (8) into formula (7), then formula (7) can be expressed as:

$\{\begin{matrix} {\overset{\cdot \cdot}{e e}}_{11} ((t t)) = = {e e}_{22} ((t t)) \\ {\overset{\cdot \cdot}{e e}}_{22} ((t t)) = = {e e}_{33} ((t t)) \\ {\overset{\cdot \cdot}{e e}}_{33} ((t t)) = = \overset{~ ~}{d d} ((t t)) + + {a a}_{m m} (({u u}_{I I} ((t t)) + + {u u}_{G G P P D D.} ((t t)))) \\ y the y ((t t)) = = {x x}_{11} ((t t)) \end{matrix} - - - - - - ((99))$

2)为采用基于分离实现方法的广义PID控制器对被控车辆进行跟踪控制，以下将通过引入一变量μ(t)来动态调节基于位移误差的积分的输入部分u_I(t)的形式，迫使被控车辆的运动按照理想的可控模式来变化，其具体过程为：2) In order to use the generalized PID controller based on the separation method to track and control the controlled vehicle, a variable μ(t) will be introduced to dynamically adjust the form of the input part u _I (t) based on the integral of the displacement error, Force the movement of the controlled vehicle to change according to the ideal controllable mode, the specific process is:

①引入如下形式的变量σ(t)：① Introduce a variable σ(t) of the following form:

$σ σ ((t t)) = = \overset{~ ~}{d d} ((t t)) + + {a a}_{m m} {u u}_{I I} ((t t)) - - - - - - ((1010))$

或等价地有or equivalently have

$σ σ ((t t)) = = {\overset{\cdot &Center Dot;}{e e}}_{33} ((t t)) - - {a a}_{m m} {u u}_{G G P P D D.} ((t t)) - - - - - - ((1111))$

②引入变量μ(t)，它由如下动态方程来确定：②Introduce the variable μ(t), which is determined by the following dynamic equation:

$\{\begin{matrix} \overset{\cdot \cdot}{μ μ} ((t t)) = = \{\begin{matrix} - - γ γ s the s i i g g n no ((σ σ ((t t)))),, & | | μ μ ((t t)) | | \leq \leq 11 \\ - - ω ω μ μ ((t t)),, & | | μ μ ((t t)) | | > > 11 \end{matrix} \\ μ μ ((00)) = = s the s i i g g n no ((σ σ ((00)))) \end{matrix} - - - - - - ((1212))$

式(12)中，ω为设计参数，只要取ω＞0即可，为简单起见，ω常取0.5；γ表示设计参数，其根据被控车辆的特征进行选取，可取为一个给定的正数；sign表示符号函数。In formula (12), ω is the design parameter, as long as ω>0 is sufficient, for simplicity, ω is usually 0.5; γ represents the design parameter, which is selected according to the characteristics of the controlled vehicle, and can be taken as a given Number; sign means sign function.

③用变量μ(t)来调节基于位移误差的积分的输入部分u_I(t)的形式，这里取u_I(t)与变量μ(t)之间的关系式为：③Use the variable μ(t) to adjust the form of the input part u _I (t) based on the integral of the displacement error, here the relationship between u _I (t) and the variable μ(t) is:

${u u}_{I I} ((t t)) = = {k k}_{00} μ μ ((t t)) m m i i n no (({&Integral; &Integral;}_{{t t}_{00}}^{t t} | | e e ((s the s)) | | d d s the s,, M m)) - - - - - - ((1313))$

式(13)中，k₀和M均表示设计参数；表示取最小值运算，其作用是防止过大所导致的被控变量的超调或整个车辆控制系统稳定性能的下降；s表示积分变量。In formula (13), _k0 and M both represent design parameters; Represents the operation of taking the minimum value, and its function is to prevent The overshoot of the controlled variable or the decline of the stability of the entire vehicle control system caused by too large; s represents the integral variable.

为简化变量μ(t)对基于位移误差的积分的输入部分u_I(t)形式的调节，可以将基于位移误差的积分的输入部分u_I(t)与变量μ(t)之间的关系式直接取为：In order to simplify the adjustment of the variable μ(t) to the input part u _I (t) of the integral based on the displacement error, the relationship between the input part u _I (t) of the integral based on the displacement error and the variable μ(t) can be The formula is directly taken as:

u_I(t)＝k₀μ(t)M (14)u _I (t) = k ₀ μ(t)M (14)

式(13)和式(14)中，有关设计参数γ、k₀和M的选取，需满足如下条件：In formula (13) and formula (14), the selection of design parameters γ, k ₀ and M must meet the following conditions:

${k k}_{00} γ γ M m &GreaterEqual; &Greater Equal; \underset{t t &GreaterEqual; &Greater Equal; {t t}_{00}}{s the s u u p p} | | \frac{d d}{d d t t} [[\overset{~ ~}{d d} ((t t))]] | | - - - - - - ((1515))$

式(15)中，sup表示取上确界的运算,表示总扰动的广义导数。In formula (15), sup represents the operation of taking the supremum, represents the total disturbance The generalized derivative of .

④通过选取设计参数ω、γ、k₀和M，可保证在有限时间内使式(10)或(11)中σ(t)＝0。④ By selecting the design parameters ω, γ, k ₀ and M, it can be ensured that σ(t) = 0 in formula (10) or (11) within a limited time.

3)选取基于位移的误差、速度的误差和加速度的误差的输入部分u_GPD(t)的形式，并确定基于位移的误差、速度的误差和加速度的误差的输入部分u_GPD(t)中的系数，其具体过程为：3) Select the form of the input part u _GPD (t) based on displacement error, velocity error and acceleration error, and determine the input part u _GPD (t) based on displacement error, velocity error and acceleration error coefficient, the specific process is:

将式(10)代入式(9)中，得到Substituting formula (10) into formula (9), we get

$\{\begin{matrix} {\overset{\cdot &Center Dot;}{e e}}_{11} ((t t)) = = {e e}_{22} ((t t)) \\ {\overset{\cdot &Center Dot;}{e e}}_{22} ((t t)) = = {e e}_{33} ((t t)) \\ {\overset{\cdot &Center Dot;}{e e}}_{33} ((t t)) = = σ σ ((t t)) + + {a a}_{m m} {u u}_{G G P P D D.} ((t t)) \\ y the y ((t t)) = = {x x}_{11} ((t t)) \end{matrix} - - - - - - ((1616))$

由于在步骤2)中对基于位移误差的积分的输入部分u_I(t)中引入了变量μ(t)，并选取了设计参数ω、γ、k₀和M使得σ(t)＝0，则由式(16)得到：Since the variable μ(t) is introduced in the input part u _I (t) of the integral based on the displacement error in step 2), and the design parameters ω, γ, k ₀ and M are selected so that σ(t)=0, Then it is obtained from formula (16):

$\{\begin{matrix} {\overset{\cdot &Center Dot;}{e e}}_{11} ((t t)) = = {e e}_{22} ((t t)) \\ {\overset{\cdot &Center Dot;}{e e}}_{22} ((t t)) = = {e e}_{33} ((t t)) \\ {\overset{\cdot &Center Dot;}{e e}}_{33} ((t t)) = = {a a}_{m m} {u u}_{G G P P D D.} ((t t)) \\ y the y ((t t)) = = {x x}_{11} ((t t)) \end{matrix} - - - - - - ((1717))$

由式(17)可知，基于位移的误差、速度的误差和加速度的误差的输入部分u_GPD(t)只与被控车辆的状态有关。因此，可根据被控车辆的状态，选取u_GPD(t)的形式，对此可以充分利用现代控制理论的结论来实现，如采用线性形式、非线性形式或最优化形式等。通常，该输入部分u_GPD(t)可以采用以下线性形式：It can be known from formula (17) that the input part _uGPD (t) based on displacement error, velocity error and acceleration error is only related to the state of the controlled vehicle. Therefore, according to the state of the controlled vehicle, the form of u _GPD (t) can be selected, which can be realized by making full use of the conclusions of modern control theory, such as linear form, nonlinear form or optimal form. In general, this input part u _GPD (t) can take the following linear form:

u_GPD(t)＝k₁e₁(t)+k₂e₂(t)+k₃e₃(t) (18)u _GPD (t) = k ₁ e ₁ (t) + k ₂ e ₂ (t) + k ₃ e ₃ (t) (18)

或以下非线性形式：or the following non-linear form:

u_GPD(t)＝k₁|e₁(t)|^αsign(e₁(t))+k₂|e₂(t)|^αsign(e₂(t))+k₃|e₃(t)|^αsign(e₃(t))(19)u _GPD (t)＝k ₁ |e ₁ (t)| ^α sign(e ₁ (t))+k ₂ |e ₂ (t)| ^α sign(e ₂ (t))+k ₃ |e ₃ ( t)| ^α sign(e ₃ (t))(19)

式(18)和式(19)中，k₁、k₂和k₃分别表示基于位移的误差、速度的误差和加速度的误差的输入部分u_GPD(t)的系数，α表示非线性的指数，通常0＜α≤1。In formula (18) and formula (19), k ₁ , k ₂ and k ₃ represent the coefficients of the input part u _GPD (t) based on displacement error, velocity error and acceleration error respectively, and α represents the nonlinear exponent , usually 0<α≤1.

为保证控制输入的连续性，可以将式(19)中的符号函数用一种扩展形式的饱和函数代替，即：In order to ensure the continuity of the control input, the sign function in formula (19) can be replaced by an extended form of saturation function, namely:

u_GPD(t)＝k₁fal(e₁(t),α,δ)+k₂fal(e₂(t),α,δ)+k₃fal(e₃(t),α,δ) (20)u _GPD (t)＝k ₁ fal(e ₁ (t),α,δ)+k ₂ fal(e ₂ (t),α,δ)+k ₃ fal(e ₃ (t),α,δ) (20)

其中，in,

$f f a a l l ((x x,, α α,, δ δ)) = = \{\begin{matrix} {xδ xδ}^{α α - - 11},, & | | x x | | \leq \leq δ δ \\ | | x x {| |}^{α α} s the s i i g g n no ((x x)),, & | | x x | | > > δ δ \end{matrix} - - - - - - ((21 twenty one))$

式(21)中，x为自变量，x可以根据需要分别取为位移误差变量e₁(t)、速度误差变量e₂(t)和加速度误差变量e₃(t)，α和δ均为设计参数，通常取0＜α≤1,0＜δ≤0.1。In formula (21), x is an independent variable, and x can be taken as displacement error variable e ₁ (t), velocity error variable e ₂ (t) and acceleration error variable e ₃ (t) according to needs, and α and δ are both Design parameters, usually 0<α≤1, 0<δ≤0.1.

直接选取使式(17)表示的动力系统在原点(0,0,0)稳定的系数作为位移误差项的系数k₁、速度误差项的系数k₂和加速度误差项的系数k₃。Directly select the coefficients that make the dynamical system represented by formula (17) stable at the origin (0,0,0) as the coefficient k 1 of the displacement error term, the coefficient k ₂ of the velocity error term, and the coefficient k ₃ _of the acceleration error term.

4)根据步骤2)确定的设计参数γ、k₀和M，以及步骤3)确定的位移误差项的系数k₁、速度误差项的系数k₂和加速度误差项的系数k₃，确定被控车辆的控制系统，亦即通过对广义PID控制器的上述分离实现方式来对被控车辆的位移、速度和加速度进行控制，达到对被控车辆安全性和平顺度的控制目的。 ₄ ₎ _Determine the _controlled The control system of the vehicle controls the displacement, speed and acceleration of the controlled vehicle through the above-mentioned separate implementation of the generalized PID controller, so as to achieve the purpose of controlling the safety and smoothness of the controlled vehicle.

上述基于广义PID控制器分离实现方法对车辆的安全性及平顺度的控制中，如图2所示，若被控车辆的实际测量信号只有位移信号y(t)，或实际测量的位移信号y(t)中含有噪声，则先利用两级跟踪-微分器对实际测量的位移信号y(t)进行预处理，再采用与前述步骤1)～4)相同的方法对被控车辆的位移、速度和加速度进行控制。其中，利用两级跟踪-微分器对实际测量的位移信号y(t)进行预处理的过程具体包括：首先，采用第一级跟踪-微分器对实际测量的位移信号y(t)进行处理，得到实测位移信号的估计信号及实测位移的导数信号，分别仍记为y(t)和其次，将该位移的导数信号看作是被控车辆的速度信号，对得到的速度信号利用第二级跟踪-微分器，将获得的速度的导数信号仍记为并将其看作是被控车辆的加速度信号；最后用经两级跟踪-微分器处理后的结果，即实际测量的位移信号的估计信号，以及实际测量的位移信号的一阶导数、二阶导数，分别代替前述步骤1)～4)中被控车辆实际的位移、速度和加速度信号。采用与前述步骤1)～4)相同的方法对被控车辆的位移、速度和加速度进行控制。In the control of the safety and smoothness of the vehicle based on the separation of the generalized PID controller, as shown in Figure 2, if the actual measurement signal of the controlled vehicle is only the displacement signal y(t), or the actual measured displacement signal y (t) contains noise, first use the two-stage tracking-differentiator to preprocess the actual measured displacement signal y(t), and then use the same method as the previous steps 1) to 4) to control the displacement of the controlled vehicle, Speed and acceleration are controlled. Wherein, the process of using the two-stage tracking-differentiator to preprocess the actually measured displacement signal y(t) specifically includes: firstly, using the first-stage tracking-differentiator to process the actually measured displacement signal y(t), Obtain the estimated signal of the measured displacement signal and the derivative signal of the measured displacement, which are still recorded as y(t) and Second, the derivative signal of the displacement As the speed signal of the controlled vehicle, use the second-level tracking-differentiator for the obtained speed signal, and still record the obtained speed derivative signal as And regard it as the acceleration signal of the controlled vehicle; finally use the result processed by the two-stage tracking-differentiator, that is, the estimated signal of the actual measured displacement signal, and the first derivative and second order derivative of the actually measured displacement signal Derivatives respectively replace the actual displacement, velocity and acceleration signals of the controlled vehicle in steps 1) to 4). The displacement, speed and acceleration of the controlled vehicle are controlled by the same method as the aforementioned steps 1) to 4).

上述各实施例仅用于说明本发明，其中各部件的结构、连接方式和方法步骤等都是可以有所变化的，凡是在本发明技术方案的基础上进行的等同变换和改进，均不应排除在本发明的保护范围之外。The above-mentioned embodiments are only used to illustrate the present invention, wherein the structure, connection mode and method steps of each component can be changed, and any equivalent transformation and improvement carried out on the basis of the technical solution of the present invention should not be used. excluded from the protection scope of the present invention.

Claims

1. A control method for vehicle safety and smoothness comprises the following steps:

1) the following forms of controlled vehicle systems are targeted:

in the formula (1), x₁(t)、x₂(t) and x₃(t) respectively representing the displacement, speed and acceleration of the controlled vehicle; u (t) represents engine input, i.e.A control input; and a [ x ]₂(t)]And b [ x ]₂(t),x₃(t)]Respectively have the following forms:

in equations (2) and (3), m represents the mass of the controlled vehicle, τ represents the time constant of the engine, and K_dRepresenting the aerodynamic drag coefficient, d_mRepresenting the mechanical resistance of the controlled vehicle;

assume that the target of control is to let the actual displacement y (t) of the vehicle be x₁(t) trackable Up set Displacement y_r(t) letting the actual speed of the vehicleCapable of tracking the set speedLet the actual acceleration of the vehicleCapable of tracking an upper set accelerationIntroduce the following displacement error variable e₁(t), speed error variable e₂(t) and an acceleration error variable e₃(t)：

According to equations (1) and (4), the tracking control problem of the vehicle is converted into a stability problem of the following error system at the origin (0,0, 0):

based on a [ x ]₂(t)]The gain as a vehicle control input satisfies a constraint:wherein a is_mAnd a_MAll known constants, then equation (5) is written as:

in the formula (6), theThe total disturbance of the error system, which is considered as expressed by equation (6), is noted as:

splitting the control input u (t) into an input part u based on an integral of the displacement error_I(t) and an input section u based on the error of the displacement, the error of the velocity and the error of the acceleration_GPD(t), i.e., the entire control input is divided into two parts:

u(t)＝u_I(t)+u_GPD(t) (7)

when equation (7) is substituted for equation (6), the error system represented by equation (6) is simplified as follows:

2) dynamic adjustment of the input part u based on the integral of the displacement error by introducing a variable mu (t)_I(t) the movement of the vehicle is forced to change according to an ideal controllable mode, and the specific process is as follows:

introducing a variable σ (t) of the form:

introducing a variable mu (t), which is determined by the following dynamic equation:

in the formula (10), omega is a design parameter, and omega is more than 0; gamma represents a design parameter, which is selected according to the characteristics of the controlled vehicle and takes a positive number; sign represents a sign function;

③ use the variable μ (t) to adjust the input part u based on the integral of the displacement error_I(t) form, input part u based on integral of displacement error_IThe relationship between (t) and the variable μ (t) is taken as:

in formula (11), k₀And M each represents a design parameter,the minimum value is taken for operation, and s represents an integral variable;

design parameters gamma, k₀And M is required to satisfy the following conditions:

in the formula (12), sup represents an operation of taking a supremum limit,representing total disturbanceThe generalized derivative of (a);

④ by selecting the design parameters omega, gamma and k₀And M, guaranteed for a limited timeThe inner equation σ (t) holds 0;

3) selecting an input part u based on the error of the displacement, the error of the velocity and the error of the acceleration_GPD(t) and determining an input part u based on the error of the displacement, the error of the velocity and the error of the acceleration_GPDThe coefficient of the corresponding item in (t) is specifically processed as follows:

substituting formula (9) into formula (8) to obtain

Due to the fact that in step 2) the input part u based on the displacement error integral is integrated_I(t) introducing variable mu (t) and selecting design parameters omega, gamma and k₀And M is such that σ (t) becomes 0, then it is obtained from formula (13):

from the equation (14), the input part u based on the displacement error, the velocity error and the acceleration error_GPD(t) is dependent only on the state of the controlled vehicle, and u is selected according to the state of the controlled vehicle_GPDIn the form of (t), a coefficient for stabilizing the power system represented by the formula (14) at the origin (0,0,0) may be directly selected as the coefficient k of the displacement error term₁Coefficient k of the velocity error term₂And coefficient k of the acceleration error term₃；

4) The design parameters gamma and k determined according to the step 2)₀And M, and the coefficient k of the displacement error term determined in step 3)₁Coefficient k of the velocity error term₂And coefficient k of the acceleration error term₃And determining a control system of the controlled vehicle, namely controlling the displacement, the speed and the acceleration of the controlled vehicle through a separation implementation mode to achieve the aim of controlling the safety and the smoothness of the controlled vehicle.

2. A method of controlling vehicle safety and smoothness as claimed in claim 1, wherein said method further comprises the step of controlling the vehicle safety and smoothnessIn the following steps: in said step 2), the input part u of the displacement error-based integral of the variable μ (t) is simplified_I(t) adjustment based on the input part u of the integral of the displacement error_IThe relation between (t) and the variable μ (t) is taken directly as:

u_I(t)＝k₀μ(t)M (15)

in the formula (16), sup represents an operation for taking the supremum limit,representing total disturbanceThe generalized derivative of (a).

3. A vehicle safety and smoothness control method as claimed in claim 1 or 2, wherein: in said step 3), an input section u based on the error of the displacement, the error of the velocity and the error of the acceleration_GPD(t) takes a linear form or a non-linear form.

4. A vehicle safety and smoothness control method as claimed in claim 1 or 2, wherein: in said step 3), an input section u based on the error of the displacement, the error of the velocity and the error of the acceleration_GPD(t) takes the following linear form:

u_GPD(t)＝k₁e₁(t)+k₂e₂(t)+k₃e₃(t) (17)

or the following non-linear form:

u_GPD(t)＝k₁|e₁(t)|^αsign(e₁(t))+k₂|e₂(t)|^αsign(e₂(t))+k₃|e₃(t)|^αsign(e₃(t))(18)

in formulae (17) and (18), k₁、k₂And k₃Input section u representing displacement-based error, velocity-based error, and acceleration-based error, respectively_GPD(t) coefficients of the displacement error term, the velocity error term, and the acceleration error term, α representing an exponent of the nonlinearity, 0 < α ≦ 1.

5. A method of controlling vehicle safety and smoothness as claimed in claim 4, wherein: in the step 3), to ensure the continuity of the control input, the sign function in the equation (18) is replaced by an extended saturation function, that is:

u_GPD(t)＝k₁fal(e₁(t),α,)+k₂fal(e₂(t),α,)+k₃fal(e₃(t),α,) (19)

wherein,

in the formula (20), x is an independent variable and is taken as a displacement error variable e respectively according to needs₁(t), speed error variable e₂(t) and an acceleration error variable e₃(t) and α are design parameters, 0 is more than α and less than or equal to 1, and 0 is less than or equal to 0.1.

6. A vehicle safety and smoothness control method as claimed in claim 1, 2 or 5, wherein: when the actual measurement signal of the controlled vehicle only contains the displacement signal y (t) or the actual measurement displacement signal y (t) contains noise, the displacement, the speed and the acceleration of the controlled vehicle are controlled, and the method specifically comprises the following steps:

1) utilizing a two-stage tracking-differentiator to preprocess the actually measured displacement signal y (t), which specifically comprises:

first, a first level of tracking is employed-the differentiator processes the actually measured displacement signal y (t) to obtain an estimated signal of the actually measured displacement and a derivative signal of the actually measured displacement, which are still denoted as y (t) andsecondly, the derivative signal of the displacement is measuredRegarding the speed signal of the controlled vehicle, the obtained speed signal is subjected to a second-stage tracking-differentiator, and the derivative signal of the obtained speed is recorded asAnd regarding the acceleration signal as the acceleration signal of the controlled vehicle; finally, the result processed by the two-stage tracking-differentiator, namely the estimation signal of the displacement signal which is actually measured and the first derivative and the second derivative of the displacement signal which is actually measured are used for respectively replacing the actual displacement, speed and acceleration signals of the controlled vehicle;

2) and controlling the displacement, the speed and the acceleration of the controlled vehicle by adopting the same method as the steps 1) to 4).