标准编号:	GB 17675-2021
中文名称:	汽车转向系 基本要求
英文名称:	Steering system of motor vehicles—Basic requirements
中标分类:	T23    转向与操纵系统
行业分类:	GB    国家标准
ICS分类:	43.040.50 43.040.50    传动装置、悬挂装置 43.040.50
发布机构:	国家市场监督管理总局 国家标准化管理委员会
发布日期:	2021-02-20
实施日期:	2022-1-1
标准状态:	valid
替代旧标准:	GB 17675-1999 汽车转向系 基本要求
翻译语言:	英文
文件格式:	PDF
中文字符数:	26000 字
翻译价格(元):	1610.0
交付时间:	付款后 1 个工作日

Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative. This standard is developed in accordance with the rules given in GB/T 1.1-2009. This standard replaces GB 17675-1999 Steering system of motor vehicles - Basic requirements, with respect to which, the following main technical changes have been made in addition to editorial changes: ——the application scope is modified (see Clause 1; Clause 1 of Edition 1999); ——Clause 2 "Normative references" is added (see Clause 2); ——the contents of Clause 3 are revised: the "terms" is changed to "terms and definitions" (see Clause 3; Clause 2 of Edition 1999); basic terms are added (see 3.1); the definition of "steering system" is modified (see 3.1.1; 2.1 of Edition 1999); the steering parameters are added (see 3.1.2); the types of steering system are added (see 3.1.3); the arrangement of the steered wheels is added (see 3.1.4); the types of steering transmission are added (see 3.1.5); the term and definition of trailers steering electric control line are added (see 3.1.6); and the functional safety terms are added (see 3.2); ——the "basic requirements" is changed to "technical requirements" (see Clause 4; Clause 3 of Edition 1999); ——the requirement that the steering disc must be on the left is deleted (3.1 of Edition 1999); ——the requirement that full-power steering equipment shall not be used is deleted (3.3 of Edition 1999); ——the requirement that the steering system parts and components shall not hook the driver's clothes is deleted (3.13 of Edition 1999); ——the requirements for motor vehicles are added (see 4.1); ——the requirements for portability and safety of the motor vehicle in its maximum design speed range and the steering force when the steering system is in good condition are modified (see 4.1.1; 3.9 and 3.10 of Edition 1999); ——the requirements for steering system for straight-line driving of motor vehicles are revised (see 4.1.2; 3.7 of Edition 1999); ——the requirement that the steering direction shall be consistent with the driving direction of the vehicle is modified (see 4.1.3; 3.4 of Edition 1999); ——the design, manufacturing, assembly and inspection requirements of the steering system are modified (see 4.1.4; 3.5 and 3.6 of Edition 1999); ——the requirement that the electrical control of steering system of motor vehicles shall meet the requirements of electromagnetic compatibility is added (see 4.1.5); ——the requirements for adjustable components in steering system are added (see 4.1.6); ——the requirements for steered wheels are modified (see 4.1.7; 3.2 of Edition 1999); ——the basic requirements for energy supply are modified (see 4.1.8; 3.12 of Edition 1999); ——the functional safety requirements for steering electronic control system are added (see 4.1.9); ——the requirements for trailers are added (see 4.2); ——the requirement that the trailer and tractor travel in the same direction when the vehicle combination travels in straight line is added (see 4.2.1); ——the requirements for steered wheels of semi-trailers are added (see 4.2.2); ——the requirements for steering system in straight-line driving of vehicle combination are added (see 4.2.3); ——the requirements for turning circle when the vehicle combination turns stably at different speeds are added (see 4.2.4); ——the requirements for the out value of vehicle combination when it leaves the turning circle are added (see 4.2.5); ——the requirements for out values of multiple steering axle draw-bar trailers, semi-trailers and center axle trailers with steering axles during straight-line driving and steady-state steering in turning circle and when leaving the turning circle are added; the axle-load ratio conditions are proposed according to whether the trailer with self-tracking steering axle is tested (see 4.2.6); ——the requirements for vehicle combination with purely hydraulic steering transmission are added (see 4.2.7); ——the requirements for trailers and tractors to realize trailer steering by tractor electric energy are added (see 4.2.8); ——the requirements for adjustable components in trailer steering system are added (see 4.2.9); ——the requirement that the electrical control of trailer steering system shall meet the requirements of electromagnetic compatibility is added (see 4.2.10); ——the failure requirements are added (see 4.3); ——the general requirements are added (see 4.3.1); ——the requirements for steering angle and steering control force when the power assisted steering system fails are modified (see 4.3.2; 3.11 of Edition 1999); ——the full-power steering equipment is added (see 4.3.3); ——the alarm signal is added (see 4.4); ——the general requirements are added (see 4.4.1); ——the requirements for alarm signal when the vehicle with full-power steering equipment fails are added (see 4.4.2); ——the requirements for alarm signal of additional steering equipment of trailer are added (see 4.4.3); ——the clause "test conditions" is changed to "test methods" (see Clause 5; Clause 4 of Edition 1999); ——the test conditions are added (see 5.1); ——the requirements for test roads are modified (see 5.1.1; 4.1 of Edition 1999); ——the requirements for loading and tire pressure of test vehicles are modified (see 5.1.2 and 5.1.3; 4.2 of Edition 1999); ——the requirements for simulated power load of test vehicles are added (see 5.1.4); ——the motor vehicle test is added (see 5.2); ——the test on abnormal vibration when the motor vehicle leaves the turning circle is added (see 5.2.1); ——the test of insufficient steering for motor vehicles is added (see 5.2.2); ——the requirements for glitch signal processing in measurement of motor vehicle steering control force are added (see 5.2.3); ——the measurement of steering control force when the steering system of motor vehicle is in good condition is added (see 5.2.4); ——the measurement of steering control force in case of fault in the steering system of motor vehicle is added (see 5.2.5); ——the trailer test is added (see 5.3); ——the straight-line driving and abnormal vibration tests of vehicle combination are added (see 5.3.1); ——the turning circle test of vehicle combination in steady-state steering is added (see 5.3.2); ——the out value test of vehicle combination when leaving the turning circle is added (see 5.3.3); ——the turning clearance width test of vehicle combination is added (see 5.3.4); ——the requirement for test times of vehicle combination is added (see 5.3.5); ——the supplementary requirements for vehicles with auxiliary steering equipment (ASE) are added (see Annex A); ——the functional safety requirements are added (see Annex B); ——the requirements for trailers with purely hydraulic steering transmission equipment are added (see Annex C); ——the special requirements for tractor to provide electric energy to trailer steering system are added (see Annex D). The technical contents of this standard are revised by reference to UN R79 Uniform provisions concerning the approval of vehicles with regard to steering equipment (Revision 4). This standard was proposed by and is under the jurisdiction of the Ministry of Industry and Information Technology of the People's Republic of China. The previous edition of the standard is as follows: ——GB 17675-1999. Steering system of motor vehicles - Basic requirements 1 Scope This standard specifies the terms and definitions, technical requirements and test methods for the steering system of motor vehicles. This standard is applicable to Categories M and N vehicles and Category O trailers specified in GB/T 15089. This standard is not applicable to: ——pneumatic transmission steering system; ——vehicles with autonomous steering system specified in 3.1.1.5. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. GB/T 3730.1 Motor vehicles and trailers - Types - Terms and definitions GB/T 3730.2 Road vehicle - Masses - Vocabulary and codes GB/T 3730.3 Motor vehicles and towed vehicles - Dimensions of vehicles - Terms and definitions GB/T 5053.3 Road vehicles - Connectors for the electrical connection of towing and towed vehicles - Definitions tests and requirements GB/T 5563 Rubber and plastics hoses and hose assemblies - Hydrostatic testing GB/T 7939 Hydraulic fluid power - Hose assemblies - Test methods GB/T 9574 Rubber and plastics hoses and hose assemblies - Ratios of proof and burst pressure to maximum working pressure GB/T 12540 Minimum turning circle diameter, minimum turning clearance circle diameter and out value test method for motor vehicles GB/T 15089 Classification of power-driven vehicles and trailers GB/T 20716.1 Road vehicles - Connectors for the electrical connection of towing and towed vehicles - Part 1: Connectors for braking systems and running gears of vehicles with 24V nominal supply voltage GB/T 20718 Road vehicles - Connectors for the electrical connection of towing and towed vehicles - 13-pole connector for vehicles with 12V nominal supply voltage GB/T 34590 (All parts) Road vehicles - Functional safety GB 34660 Road vehicles - Requirements and test methods of electromagnetic compatibility GB/T 35360 Motor vehicle - Steering system - Terms and definitions ISO 2575: 2010 Road vehicles - Symbols for controls, indicators and telltales 3 Terms and definitions For the purposes of this document, the terms and definitions given in GB/T 3730.1, GB/T 3730.2, GB/T 3730.3, GB/T 12540, GB/T 15089, GB/T 34590 and GB/T 35360 as well as the following apply. 3.1 Basic terms 3.1.1 steering system system for changing or maintaining the driving direction of a vehicle Note: It includes steering control equipment, steering transmission equipment, steered wheels and energy supply equipment (if any). 3.1.1.1 steering control equipment operating mechanism in the steering system that controls the steering with or without the direct intervention of the driver Note: For the steering system in which the steering force is wholly or partially provided by the muscle strength of the driver, the steering control equipment includes all components that convert the steering control force into steering force by mechanical, hydraulic or electric means. 3.1.1.2 steering transmission equipment combination of parts and components that form a functional connection between the steering control equipment and the steered wheels for realizing control transmission and/or energy transmission Note: According to the control and/or energy transmission mode, it may be divided into mechanical type, hydraulic type, electric type and various combinations thereof. 3.1.1.2.1 control transmission function of transmitting a control signal command to control the action of the steering equipment 3.1.1.2.2 energy transmission function of transmitting energy to steered wheels to control/adjust steering 3.1.1.3 steered wheels wheels whose moving direction can be changed directly or indirectly relative to the longitudinal axis of the motor vehicle, so as to control the driving direction of the motor vehicle Note: Components such as steering knuckle and kingpin are covered. 3.1.1.4 energy supply equipment functional equipment in steering system that is used to provide energy, control energy distribution and store energy Note: It includes storage reservoir, pipeline, wiring harness and medium, but excludes the engine (except the engine supplying energy to the power assisted steering system) and the driving of the engine to the energy source. 3.1.1.4.1 energy source component that provides energy in the required form 3.1.1.4.2 energy reservoir component of the energy supply equipment that stores the energy Note: For example, pressurizable hydraulic accumulator or vehicle battery. 3.1.1.4.3 storage reservoir component for storing working medium with internal pressure at normal pressure Note: For example, steering oil tank. 3.1.1.5 autonomous steering system vehicle integrated composite electronic control system that makes the vehicle travel along the determined or corrected path by responding to the reception and transmission of signals outside the vehicle; wherein, the driver is not required to have dominant control over the vehicle 3.1.1.6 advanced driver assistance steering system system in addition to the main steering equipment of the motor vehicle, used to help the driver steer Note: In this system, the driver still controls the vehicle all the time. 3.1.2 steering parameters 3.1.2.1 steering control force force acting on steering control equipment for vehicle steering 3.1.2.2 steering time time required from the start of the steering control equipment to the moment when the steered wheel reaches the specific steering angle 3.1.2.3 steering angle intersection angle formed by the intersecting line of the longitudinal center symmetry plane of the wheel and the ground and the projection of the longitudinal axis of the vehicle on the ground during steering 3.1.2.4 steering forces all forces transmitted through the steering transmission equipment to drive the steered wheels to rotate 3.1.2.5 mean steering transmission ratio ratio of the steering angle of the steering disc from one limit position to the other limit position to the mean steering angle of the steered wheel (half of the sum of the steering angles of the left and right steered wheels) 3.1.2.6 turning circle maximum circle projected by all points on the vehicle (excluding the external indirect vision equipment and the front direction-indicator lamp) on the ground plane when the vehicle travels in a circle 3.1.2.7 nominal radius of steering control minimum dimension from the rotation center to the rim of steering disc during steered wheel control Note: If other control forms are adopted, it refers to the distance from the rotation center to the steering control force application point. If multiple application points are available, the point with the maximum force shall be taken. 3.1.3 types of steering system 3.1.3.1 Motor vehicles 3.1.3.1.1 main steering equipment equipment in the steering system that mainly determines the driving direction of a vehicle, which may include: ——manual steering equipment equipment of which the steering force comes from the steering control force provided by the driver only ——power assisted steering equipment equipment of which the steering force comes from the steering control force provided by the driver and one or more energy supply equipment Note: It includes the equipment of which the steering force is only provided by one or more energy supply equipment when the steering system is in good condition, and may still be provided by the driver manually when the steering system (with power assisted equipment) is in fault condition, to complete the steering action. ——full-power steering equipment equipment of which the steering force is completely provided by one or more energy supply components 3.1.3.1.2 self-tracking steering equipment equipment that changes the steering angle of one or more non-steered wheels only when the wheels are subjected to forces and/or moments from the ground 3.1.3.1.3 auxiliary steering equipment; ASE equipment added on categories M and N vehicles that makes the steered wheels and/or wheels (front and/or rear) on other axles adjust the same or opposite steering angles in addition to the steering angle provided by the main steering equipment for adjusting the steering quality 3.1.3.2 Trailers 3.1.3.2.1 trailers self-tracking steering equipment equipment that changes the steering angle of one or more wheels only when the trailer wheels are subjected to forces and/or moments from the ground 3.1.3.2.2 articulated steering equipment that changes the driving direction of tractor and generates the steering force by forming a relative angle between the longitudinal axes of tractor and trailer through the articulated mechanism of tractor and trailer when the vehicle is running 3.1.3.2.3 self-steering equipment that changes the driving direction of tractor and generates the steering force through the angle formed by the longitudinal axis of the trailer frame or substitute load and that of the draw bar and turntable frame when the vehicle is running 3.1.3.2.4 additional steering equipment equipment independent of the main steering equipment of the tractor, which selectively adjusts the steering angle of one or more axles of a trailer according to different control purposes 3.1.3.2.5 full-power steering equipment equipment of which the steering force is completely provided by one or more energy supply components 3.1.4 arrangement of the steered wheels 3.1.4.1 front-wheel steering equipment equipment that only controls all wheels of the front axle to steer in the same direction 3.1.4.2 rear-wheel steering equipment equipment that only controls all wheels of the rear axle to steer in the same direction 3.1.4.3 multi-wheel steering equipment equipment that controls one or more wheels of the front axle and the rear axle to steer 3.1.5 types of steering transmission 3.1.5.1 purely mechanical steering transmission operation in which the steering force is completely transmitted by mechanical mechanism 3.1.5.2 purely hydraulic steering transmission operation in which the steering force is completely transmitted by hydraulic pressure in at least one transmission link 3.1.5.3 purely electric steering transmission operation in which the steering force is completely transmitted by electric power in at least one transmission link 3.1.5.4 hybrid steering transmission operation in which a part of the steering force is transmitted in one of the above ways, while the other part is transmitted in another way Note: However, if the mechanical part used for transmission is only to provide drivers with sense of road, and the steering force transmitted by it may be ignored for the whole system, it shall be regarded as purely hydraulic or purely electric steering transmission. 3.1.6 trailers steering electric control line electric connection part used for trailer steering control Note: It includes data communication cables used for trailer control as well as wires and connectors used for power supply. 3.2 Functional safety terms 3.2.1 functional safety concept functional safety requirements and related information required to achieve safety goals Note: For example, safety measures taken to ensure system integrity and safe operation in fault and non-fault modes. 3.2.2 unit smallest element of a system component that may be identified, analyzed or replaced as a single entity 3.2.3 electronic control system combination of a series of units that cooperatively realize the vehicle control function by means of electronic data processing Note: The system is usually controlled by software and consists of independent functional components such as sensors, controllers and actuators, which are connected by transmission links. The system may include mechanical, electronic-pneumatic and electronic-hydraulic units. 3.2.4 transmission links connection modes of internal units for transmission of signals, operation data or energy supply Note: They are usually electronic, but may also be mechanical, pneumatic or hydraulic. 3.2.5 safety strategy strategy to ensure the safe operation of system functions in specific environmental and operating conditions (such as road conditions, vehicle conditions, traffic participants, weather conditions, etc.) 3.2.6 safety goal highest level of safety requirements obtained from hazard analysis and risk assessment 3.2.7 safety metric quantified value of specific technical parameters given to meet safety goals (not ASIL) 3.28 safety measures activities or technical solutions to avoid or control systematic failures, detect random hardware failures, control random hardware failures or mitigate their adverse effects 3.2.9 controllability capability to avoid specific damages or injuries through the timely response of the personnel involved or the support of external measures 4 Technical requirements 4.1 Requirements for motor vehicles 4.1.1 The steering system shall ensure the portability and safety of steering operation of the motor vehicle within its maximum design speed range. When the steering system is in good condition, the steering control force, steering time and steering radius of the motor vehicle shall meet the requirements of Table 1. If tested according to the method required in 5.2, the motor vehicle shall have the capability of self-returning provided that the steering system is in good condition, and shall meet the requirements of Annex A if it is equipped with the auxiliary steering equipment. The motion around the grid listed in this standard refers to the motion along the steering grid.

Foreword i 1 Scope 2 Normative references 3 Terms and definitions 3.1 Basic terms 3.2 Functional safety terms 4 Technical requirements 4.1 Requirements for motor vehicles 4.2 Requirements for trailers 4.3 Requirements for failure 4.4 Alarm signal 5 Test methods 5.1 Test conditions 5.2 Motor vehicle test 5.3 Trailer test 6 Implementation date Annex A (Normative) Supplementary requirements for vehicles with auxiliary steering equipment (ASE) Annex B (Normative) Functional safety requirements Annex C (Normative) Requirements for trailers with purely hydraulic steering transmission equipment Annex D (Normative) Special requirements for power supply of vehicle combination steering system

汽车转向系 基本要求 1 范围 本标准规定了汽车转向系统的术语和定义、技术要求和试验方法。 本标准适用于GB/T 15089规定的M类、N类车辆和O类挂车。 本标准不适用于： ——气压传动转向系统； ——3.1.1.5定义的带自动转向系统的车辆。 2规范性引用文件 下列文件对于本文件的应用是必不可少的。凡是注日期的引用文件，仅注日期的版本适用于本文件。凡是不注日期的引用文件，其最新版本(包括所有的修改单)适用于本文件。 GB/T 3730.1汽车和挂车类型的术语和定义 GB/T 3730.2道路车辆 质量 词汇和代码 GB/T 3730.3 汽车和挂车的术语及其定义 车辆尺寸 GB/T 5053.3道路车辆 牵引车与挂车之间电连接器 定义、试验方法和要求 GB/T 5563橡胶和塑料软管及软管组合件 静液压试验方法 GB/T 7939 液压软管总成 试验方法 GB/T 9574 橡胶和塑料软管及软管组合件 验证压力、爆破压力与最大工作压力的比率 GB/T 12540汽车最小转弯直径、最小转弯通道圆直径和外摆值测量方法 GB/T 15089 机动车辆及挂车分类 GB/T 20716.1道路车辆 牵引车和挂车之间的电连接器 第1部分：24 V标称电压车辆的制动系统和行走系的连接 GB/T 20718道路车辆 牵引车和挂车之间的电连接器 12V13芯型 GB/T 34590(所有部分)道路车辆 功能安全 GB 34660道路车辆 电磁兼容性要求和试验方法 GB/T 35360汽车转向系统术语和定义 ISO 2575：2010道路车辆 控制器、指示器和信号装置用符号(Road vehicles—Symbols for con-trols，indicators and tell-tales) 3术语和定义 GB/T 3730.1、GB/T 3730.2、GB/T 3730.3、GB/T 12540、GB/T 15089、GB/T 34590、GB/T 35360界定的以及下列术语和定义适用于本文件。 3.1 基本术语 3.1.1 转向系统 steering system 用于改变或保持车辆行驶方向的系统。 注：包括转向操纵装置、转向传动装置、转向车轮和供能装置(如果有)。 3.1.1.1 转向操纵装置 steering control equipment 在有或没有驾驶员直接干预的情况下，转向系统中控制转向工作的操作机构。 注：对于转向力全部或部分由驾驶员的肌肉力量提供的转向系统，转向操纵装置包括把转向操纵力通过机械、液压或电动方式转换成转向力的所有部件。 3.1.1.2 转向传动装置 steering transmission equipment 在转向操纵装置和转向车轮之间构成功能性连接、实现信号传输和/或能量传输两种功能的零部件组合。 注：按照信号和/或能量传输方式，可以分为机械式、液压式和电动式及其各种组合形式。 3.1.1.2.1 信号传输 control transmission 传送控制信号指令以控制转向装置动作的功能。 3.1.1.2.2 能量传输 energy transmission 传递能量至转向车轮以控制/调节转向的功能。 3.1.1.3 转向车轮 steered wheels 其运动方向相对于汽车纵轴线能够直接或间接改变，从而控制汽车行驶方向的车轮。 注：包括转向节和主销等部件。 3.1.1.4 供能装置 energy supply equipment 转向系统中用于提供能量、控制能量分配及储存能量的功能装置。 注：包括如贮存罐、管路、线束及介质等，但不包含发动机(发动机向助力转向系统提供能量除外)以及发动机对动力源的驱动。 3.1.1.4.1 动力源 energy source 按所需形式提供能量的部件。 3.1.1.4.2 储能器 energy reservoir 供能装置中储存能量的部件。 注：如可加压的液压蓄能器或车辆蓄电池。 3.1.1.4.3 贮存罐 storage reservoir 内部压力为常压的存储工作介质的部件。 注：例如转向油罐。 3.1.1.5 自动转向系统 autonomous steering system 车辆集成复合电子控制系统，通过对车外信号的接收和传递的响应，使车辆沿着确定的或修正的路径行驶。驾驶员不必对车辆有主导控制权。 3.1.1.6 高级驾驶员辅助转向系统 advanced driver assistance steering system 除汽车主转向装置外附加的帮助驾驶员转向的系统。 注：在该系统中驾驶员仍然全时主控车辆。 3.1.2 转向参数 steering parameters 3.1.2.1 转向操纵力 steering control force 为车辆转向而作用在转向操纵装置上的力。 3.1.2.2 转向时间 steering time 从转向操纵装置开始动作到转向车轮达到特定转向角所需的时间。 3.1.2.3 转向角 steering angle 转向过程中车轮纵向中心对称平面与地面交线和车辆纵轴线在地面的投影所形成的交角。 3.1.2.4 转向力 steering forces 经由转向传动装置传输的用以驱动转向车轮转动的所有的力。 3.1.2.5 平均转向传动比 mean steering transmission ratio 转向盘从一侧极限位置到另一侧极限位置时所转过的角度，与转向车轮转过的平均转角(左右转向车轮转角之和的一半)之间的比值。 3.1.2.6 转向圆turning circle 当车辆在一个圆内行驶时，车辆上所有点(不包括外间接视野装置和前转向信号灯)在地平面上的投影的最大的圆。 3.1.2.7 转向操纵输入有效半径 nominal radius of steering control 在操纵转向盘时从转向盘旋转中心到转向盘轮缘的最小尺寸。 注：如果采用其他操纵形式，指从旋转中心到转向操纵力输入点的距离，如果存在多个这样的点，应取作用力最大的点。 3.1.3 转向系统形式types of steering system 3.1.3.1 汽车 3.1.3.1.1 主转向装置 main steering equipment 转向系统中主要确定车辆行驶方向的装置。可包括： ——人力转向manual steering equipment 转向力仅来源于驾驶员提供的转向操纵力的装置。 ——助力转向power assisted steering equipment 转向力来源于驾驶员的操纵力和一个或多个供能装置。 注：包括当转向系统完好时，转向力仅由一个或多个供能装置提供，当转向系统(带助力装置)出现故障后，转向力仍可通过驾驶员人力提供以完成转向动作的情况。 ——全动力转向full-power steering equipment 转向力完全由一个或多个供能组件提供。 3.1.3.1.2 随动转向装置 self-tracking steering equipment 仅当车轮受到来自地面的作用力和/或力矩时才改变某个或多个非转向车轮转向角的装置。 3.1.3.1.3 辅助转向装置 auxiliary steering equipment；ASE M类和N类车辆上，除了主转向装置提供的转向角外，为调整车辆转向品质而附加的另一可以使转向车轮和/或其他车轴上的车轮(前和/或后)调节相同或相反的转向角的装置。 3.1.3.2挂车 3.1.3.2.1 挂车随动转向装置trailers self-iracking steering equipment 仅当挂车车轮受到来自地面的作用力和/或力矩时才改变某个或多个车轮转向角的装置。 3.1.3.2.2 铰接转向 articulated steering 当车辆行驶时。转向运动通过牵引车和挂车间铰接机构，使牵引车和挂车纵轴线之间形成相对角度，来改变牵引车行驶方向而产生转向力的装置。 3.1.3.2.3 自转向 self-steering 当车辆行驶时，转向运动通过挂车车架或替代载荷的纵轴线与牵引杆和转盘架纵轴线所形成的角度，来改变牵引车行驶方向而产生转向力的装置。 3.1.3.2.4 附加转向装置 additional steering equipment 根据不同的操纵目的，选择性地对挂车一个或多个车轴的转向角进行调节的独立于牵引车主转向装置的装置。 3.1.3.2.5 全动力转向装置 full-power steering equipment 转向力完全由一个或多个供能组件提供的装置。 3.1.4 转向车轮布置形式 arrangement of the steered wheels 3.1.4.1 前轮转向 front-wheel steering equipment 车辆仅控制前轴所有车轮向同一方向转动的装置。 3.1.4.2 后轮转向 rear-wheel steering equipment 车辆仅控制后轴所有车轮向同一方向转动的装置。 3.1.4.3 多轮转向 multi-wheel steering equipment 车辆控制前轴和后轴的一个或多个车轮进行转向的装置。 3.1.5 转向传动形式types of steering transmission 3.1.5.1 机械转向传动purely mechanical steering transmission 转向力完全由机械机构传递。 3.1.5.2 液压转向传动purely hydraulic steering transmission 转向力至少在某一传递环节中完全由液压传递。 3.1.5.3 电动转向传动purely electric steering transmission 转向力至少在某一传递环节中完全由电动传递。 3.1.5.4 混合转向传动hybrid steering transmission 部分转向力由上述某一种方式传递，而另一部分以另一种方式传递。 注：但如果用于传动的机械部分仅为了提供驾驶员路感，而其传递的转向力对整个系统可以忽略.应视其为液压或电动转向传动。 3.1.6 挂车转向电控线路trailers steering electric control line 用于挂车转向控制功能的电气连接部分。 注：包括用于挂车控制的数据通信电缆及用于电能供应的导线、连接器。 3.2功能安全术语 3.2.1 功能安全概念 functional safety concept 为实现安全目标所需的功能安全要求及相关信息。 注：例如，为确保系统完整性及在故障和非故障模式下安全运行所实施的安全措施。 3.2.2 单元 unit 系统组件中可作为单个实体被识别、分析或替换的最小组成部分。 3.2.3 电子控制系统 electronic control system 通过电子数据处理方式协同实现车辆控制功能的一系列单元的组合。 注：该系统通常通过软件控制.由传感器、控制器和执行器等独立的功能组件构成，并通过传输链相连接。该系统可包括机械、电子-气压、电子-液压单元。 3.2.4 传输链transmission links 为了传输信号、运行数据或能量供给而用于连接内部单元的方式。 注：通常是电子的，也可以是机械、气动或者液压的。 3.2.5 安全策略 safety strategy 确保系统功能在特定环境、运行条件(如路面状况、车辆状态、交通参与者、天气条件等)下安全运行的策略。 3.2.6 安全目标 safety goal 由危害分析和风险评估得出的最高层面的安全要求。 3.2.7 安全度量 safety metric 为符合安全目标而给定的具体技术参数的量化值(安全度量并非ASIL等级)。 3.28 安全措施 safety measures 活动或技术解决方案，用以避免或控制系统性失效、探测随机硬件失效，控制随机硬件失效或减轻它们的有害影响。 3.2.9 可控性 controllability 通过所涉及人员的及时反应，或通过外部措施的支持，避免特定的伤害或损伤的能力。 4 技术要求 4.1对汽车的要求 4.1.1 转向系统应确保车辆在其最大设计车速范围内转向操纵的轻便性和安全性。转向系统完好时的汽车的转向操纵力、转向时间、转向半径应满足表1的要求。当按照5.2所要求的方法进行试验时，在转向系统完好的前提下，汽车应具有自动回正能力，如果车上安装了辅助转向装置，还应满足附录A的要求。本标准所列的网周运动均指沿转向网运动。 表1 转向系统完好时转向操纵力要求 车辆类别 转向操纵力 N 转向时间 s 转向半径 m M1 ≤150 ≤4 12 M2 ≤150 ≤4 12 M3 ≤200 ≤4 12 N1 ≤200 ≤4 12 N2 ≤250 ≤4 12 N3 ≤200 ≤4 12 4.1.2 在汽车的最大设计速度范围内，当驾驶员无异常转向修正行为和转向系统无异常振动时，不应因转向系统影响汽车直线行驶性能。 4.1.3汽车转向操纵的方向应与其行驶方向相一致，且转向角应与转向操纵装置的偏转连续对应。 对于ASE，本条款要求不适用。 对于全动力转向系统，当车辆处于静止时、或在车速不超过15 km/h的条件下行驶、或系统没有启动时，可以不必满足本条款要求。 4.1.4转向系统的设计、制造和装配应能承受车辆或车辆组合正常使用状态下的载荷，应保证在无需拆卸的情况下能够借助常规的测量装置、检查方法或试验方法检查其工作状态。除非专门设计，否则转向传动装置的任何部分不应限制最大转向角。 4.1.5 与汽车转向相关的车辆电气控制系统不得因电磁干扰而影响转向功能，并应满足GB 34660中的技术要求。 4.1.6转向传动系统中的可调节部件应能锁止。 4.1.7汽车的转向车轮不应仅是后车轮。 4.1.8转向系统可以和其他系统共用同一能源供应。但如果任何与转向系统共用相同能源的系统发生故障，转向系统仍应满足4.3中故障时的相关转向功能。 4.1.9 转向电子控制系统的功能安全要求，应按照GB/T 34590(所有部分)制定，并满足附录B的要求。 4.2对挂车的要求 4.2.1 当汽车列车向前直行，挂车应与牵引车行驶方向一致，如挂车无法自动保持直线行驶，应配备相应的调节装置。 4.2.2半挂车的后车轮可以是转向车轮。 4.2.3牵引车在水平路面上直线行驶，在最大设计速度范围内.当驾驶员无转向修正行为和转向系统无异常振动时，挂车不应因其转向系统影响车辆直线行驶性能。 4.2.4汽车列车以(25±1)km/h和5 km//h的车速匀速沿25 m半径的转向圆进行稳态转向，分别测量挂车最后面的外边缘所划过的轨迹圆半径，(25±1)km/h和5 km/h车速时的轨迹圆半径之差应不大于0.7 m。 4.2.5汽车列车以25 km/h的速度驶离25 m半径的转向圆时，牵引车沿驶离起点为切点的切线40 m的范围内(挂车尾端计)，挂车的任何部位在地面的投影都不得超出半径25 m转向圆的切线0.5 m，如图1。继续直线行驶，挂车应满足4.2.3的规定。 注：挂车驶离转向圆时的外摆值T≤0.5 m。 图1 挂车驶离时外摆值要求 4.2.6对于具有多个转向车轴的牵引杆挂车和半挂车以及至少有一个转向车轴的中置轴挂车，应满足4.2.3、4.2.4、4.2.5的规定。对于装有随动转向装置的挂车，满载条件下，非转向或自转向的车轴与随动转向车轴之间的轴荷比至少应大于1，如非转向或自转向的车轴与随动转向车轴的轴荷比大于或等于1.6，则不必进行5.3的试验。 4.2.7挂车转向系统，如采用液压转向传动，应满足附录C的要求。 4.2.8 向挂车转向系统提供电能的汽车和利用汽车的电能实施转向的挂车，应满足附录D的相关要求。 4.2.9挂车转向传动系统中的可调节部件应能锁止。对于半挂列车，当需要断开转向传动时，系统应设有锁止机构，保证零部件的正确定位连接；如果采用自动锁止，则应设置额外的手动锁止机构。 4.2.10 与挂车转向相关的车辆电气控制系统不得因电磁干扰而影响转向功能，并应满足GB 34660中的技术要求。 4.3 失效规定 4.3.1 一般规定 4.3.1.1 转向车轮、转向操纵及转向传动机构的所有机械部件，应不易损坏，且易于维护，安全特性不低于安装于车辆上的其他关键部件(如制动系统)。如果这些部件出现故障会使车辆失控，则这些部件应为金属或具有同等特性材质制成，且在转向系统正常下作时不得出现显著变形。 4.3.1.2如果转向系统存在故障，则假设任何时候都只存在一个故障，同一个转向机构上的两个车轴视为一个车轴。 4.3.1.3车辆即使出现转向系统故障，也应满足4.1.2、4.1.3的相应要求。 4.3.1.4除机械传动机构外的任何传动失效，应按4.4的规定提示驾驶员。当出现故障时，允许平均转向传动比出现变化，但不准许转向操纵力超出表2所规定的值。