標準編號:	GB 17675-2021
中文名稱:	汽車轉向系 基本要求
英文名稱:	Steering system of motor vehicles—Basic requirements
中標分類:	T23    轉向與操縱系統
行業分類:	GB    國家標準
ICS分類:	43.040.50 43.040.50    傳動裝置、懸掛裝置 43.040.50
發布機構:	國家市場監督管理總局 國家標準化管理委員會
發布日期:	2021-02-20
實施日期:	2022-1-1
標準狀態:	valid
替代舊標準:	GB 17675-1999 汽車轉向系 基本要求
翻譯語言:	英文
文件格式:	PDF
中文字符數:	26000 字
翻譯價格(元):	1610.0
交付時間:	付款后 1 個工作日

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

汽車轉向系 基本要求 1 范圍 本標準規定了汽車轉向系統的術語和定義、技術要求和試驗方法。 本標準適用于GB/T 15089規定的M類、N類車輛和O類掛車。 本標準不適用于： ——氣壓傳動轉向系統； ——3.1.1.5定義的帶自動轉向系統的車輛。 2規范性引用文件 下列文件對于本文件的應用是必不可少的。凡是注日期的引用文件，僅注日期的版本適用于本文件。凡是不注日期的引用文件，其最新版本(包括所有的修改單)適用于本文件。 GB/T 3730.1汽車和掛車類型的術語和定義 GB/T 3730.2道路車輛 質量 詞匯和代碼 GB/T 3730.3 汽車和掛車的術語及其定義 車輛尺寸 GB/T 5053.3道路車輛 牽引車與掛車之間電連接器 定義、試驗方法和要求 GB/T 5563橡膠和塑料軟管及軟管組合件 靜液壓試驗方法 GB/T 7939 液壓軟管總成 試驗方法 GB/T 9574 橡膠和塑料軟管及軟管組合件 驗證壓力、爆破壓力與最大工作壓力的比率 GB/T 12540汽車最小轉彎直徑、最小轉彎通道圓直徑和外擺值測量方法 GB/T 15089 機動車輛及掛車分類 GB/T 20716.1道路車輛 牽引車和掛車之間的電連接器 第1部分：24 V標稱電壓車輛的制動系統和行走系的連接 GB/T 20718道路車輛 牽引車和掛車之間的電連接器 12V13芯型 GB/T 34590(所有部分)道路車輛 功能安全 GB 34660道路車輛 電磁兼容性要求和試驗方法 GB/T 35360汽車轉向系統術語和定義 ISO 2575：2010道路車輛 控制器、指示器和信號裝置用符號(Road vehicles—Symbols for con-trols，indicators and tell-tales) 3術語和定義 GB/T 3730.1、GB/T 3730.2、GB/T 3730.3、GB/T 12540、GB/T 15089、GB/T 34590、GB/T 35360界定的以及下列術語和定義適用于本文件。 3.1 基本術語 3.1.1 轉向系統 steering system 用于改變或保持車輛行駛方向的系統。 注：包括轉向操縱裝置、轉向傳動裝置、轉向車輪和供能裝置(如果有)。 3.1.1.1 轉向操縱裝置 steering control equipment 在有或沒有駕駛員直接干預的情況下，轉向系統中控制轉向工作的操作機構。 注：對于轉向力全部或部分由駕駛員的肌肉力量提供的轉向系統，轉向操縱裝置包括把轉向操縱力通過機械、液壓或電動方式轉換成轉向力的所有部件。 3.1.1.2 轉向傳動裝置 steering transmission equipment 在轉向操縱裝置和轉向車輪之間構成功能性連接、實現信號傳輸和/或能量傳輸兩種功能的零部件組合。 注：按照信號和/或能量傳輸方式，可以分為機械式、液壓式和電動式及其各種組合形式。 3.1.1.2.1 信號傳輸 control transmission 傳送控制信號指令以控制轉向裝置動作的功能。 3.1.1.2.2 能量傳輸 energy transmission 傳遞能量至轉向車輪以控制/調節轉向的功能。 3.1.1.3 轉向車輪 steered wheels 其運動方向相對于汽車縱軸線能夠直接或間接改變，從而控制汽車行駛方向的車輪。 注：包括轉向節和主銷等部件。 3.1.1.4 供能裝置 energy supply equipment 轉向系統中用于提供能量、控制能量分配及儲存能量的功能裝置。 注：包括如貯存罐、管路、線束及介質等，但不包含發動機(發動機向助力轉向系統提供能量除外)以及發動機對動力源的驅動。 3.1.1.4.1 動力源 energy source 按所需形式提供能量的部件。 3.1.1.4.2 儲能器 energy reservoir 供能裝置中儲存能量的部件。 注：如可加壓的液壓蓄能器或車輛蓄電池。 3.1.1.4.3 貯存罐 storage reservoir 內部壓力為常壓的存儲工作介質的部件。 注：例如轉向油罐。 3.1.1.5 自動轉向系統 autonomous steering system 車輛集成復合電子控制系統，通過對車外信號的接收和傳遞的響應，使車輛沿著確定的或修正的路徑行駛。駕駛員不必對車輛有主導控制權。 3.1.1.6 高級駕駛員輔助轉向系統 advanced driver assistance steering system 除汽車主轉向裝置外附加的幫助駕駛員轉向的系統。 注：在該系統中駕駛員仍然全時主控車輛。 3.1.2 轉向參數 steering parameters 3.1.2.1 轉向操縱力 steering control force 為車輛轉向而作用在轉向操縱裝置上的力。 3.1.2.2 轉向時間 steering time 從轉向操縱裝置開始動作到轉向車輪達到特定轉向角所需的時間。 3.1.2.3 轉向角 steering angle 轉向過程中車輪縱向中心對稱平面與地面交線和車輛縱軸線在地面的投影所形成的交角。 3.1.2.4 轉向力 steering forces 經由轉向傳動裝置傳輸的用以驅動轉向車輪轉動的所有的力。 3.1.2.5 平均轉向傳動比 mean steering transmission ratio 轉向盤從一側極限位置到另一側極限位置時所轉過的角度，與轉向車輪轉過的平均轉角(左右轉向車輪轉角之和的一半)之間的比值。 3.1.2.6 轉向圓turning circle 當車輛在一個圓內行駛時，車輛上所有點(不包括外間接視野裝置和前轉向信號燈)在地平面上的投影的最大的圓。 3.1.2.7 轉向操縱輸入有效半徑 nominal radius of steering control 在操縱轉向盤時從轉向盤旋轉中心到轉向盤輪緣的最小尺寸。 注：如果采用其他操縱形式，指從旋轉中心到轉向操縱力輸入點的距離，如果存在多個這樣的點，應取作用力最大的點。 3.1.3 轉向系統形式types of steering system 3.1.3.1 汽車 3.1.3.1.1 主轉向裝置 main steering equipment 轉向系統中主要確定車輛行駛方向的裝置。可包括： ——人力轉向manual steering equipment 轉向力僅來源于駕駛員提供的轉向操縱力的裝置。 ——助力轉向power assisted steering equipment 轉向力來源于駕駛員的操縱力和一個或多個供能裝置。 注：包括當轉向系統完好時，轉向力僅由一個或多個供能裝置提供，當轉向系統(帶助力裝置)出現故障后，轉向力仍可通過駕駛員人力提供以完成轉向動作的情況。 ——全動力轉向full-power steering equipment 轉向力完全由一個或多個供能組件提供。 3.1.3.1.2 隨動轉向裝置 self-tracking steering equipment 僅當車輪受到來自地面的作用力和/或力矩時才改變某個或多個非轉向車輪轉向角的裝置。 3.1.3.1.3 輔助轉向裝置 auxiliary steering equipment；ASE M類和N類車輛上，除了主轉向裝置提供的轉向角外，為調整車輛轉向品質而附加的另一可以使轉向車輪和/或其他車軸上的車輪(前和/或后)調節相同或相反的轉向角的裝置。 3.1.3.2掛車 3.1.3.2.1 掛車隨動轉向裝置trailers self-iracking steering equipment 僅當掛車車輪受到來自地面的作用力和/或力矩時才改變某個或多個車輪轉向角的裝置。 3.1.3.2.2 鉸接轉向 articulated steering 當車輛行駛時。轉向運動通過牽引車和掛車間鉸接機構，使牽引車和掛車縱軸線之間形成相對角度，來改變牽引車行駛方向而產生轉向力的裝置。 3.1.3.2.3 自轉向 self-steering 當車輛行駛時，轉向運動通過掛車車架或替代載荷的縱軸線與牽引桿和轉盤架縱軸線所形成的角度，來改變牽引車行駛方向而產生轉向力的裝置。 3.1.3.2.4 附加轉向裝置 additional steering equipment 根據不同的操縱目的，選擇性地對掛車一個或多個車軸的轉向角進行調節的獨立于牽引車主轉向裝置的裝置。 3.1.3.2.5 全動力轉向裝置 full-power steering equipment 轉向力完全由一個或多個供能組件提供的裝置。 3.1.4 轉向車輪布置形式 arrangement of the steered wheels 3.1.4.1 前輪轉向 front-wheel steering equipment 車輛僅控制前軸所有車輪向同一方向轉動的裝置。 3.1.4.2 后輪轉向 rear-wheel steering equipment 車輛僅控制后軸所有車輪向同一方向轉動的裝置。 3.1.4.3 多輪轉向 multi-wheel steering equipment 車輛控制前軸和后軸的一個或多個車輪進行轉向的裝置。 3.1.5 轉向傳動形式types of steering transmission 3.1.5.1 機械轉向傳動purely mechanical steering transmission 轉向力完全由機械機構傳遞。 3.1.5.2 液壓轉向傳動purely hydraulic steering transmission 轉向力至少在某一傳遞環節中完全由液壓傳遞。 3.1.5.3 電動轉向傳動purely electric steering transmission 轉向力至少在某一傳遞環節中完全由電動傳遞。 3.1.5.4 混合轉向傳動hybrid steering transmission 部分轉向力由上述某一種方式傳遞，而另一部分以另一種方式傳遞。 注：但如果用于傳動的機械部分僅為了提供駕駛員路感，而其傳遞的轉向力對整個系統可以忽略.應視其為液壓或電動轉向傳動。 3.1.6 掛車轉向電控線路trailers steering electric control line 用于掛車轉向控制功能的電氣連接部分。 注：包括用于掛車控制的數據通信電纜及用于電能供應的導線、連接器。 3.2功能安全術語 3.2.1 功能安全概念 functional safety concept 為實現安全目標所需的功能安全要求及相關信息。 注：例如，為確保系統完整性及在故障和非故障模式下安全運行所實施的安全措施。 3.2.2 單元 unit 系統組件中可作為單個實體被識別、分析或替換的最小組成部分。 3.2.3 電子控制系統 electronic control system 通過電子數據處理方式協同實現車輛控制功能的一系列單元的組合。 注：該系統通常通過軟件控制.由傳感器、控制器和執行器等獨立的功能組件構成，并通過傳輸鏈相連接。該系統可包括機械、電子-氣壓、電子-液壓單元。 3.2.4 傳輸鏈transmission links 為了傳輸信號、運行數據或能量供給而用于連接內部單元的方式。 注：通常是電子的，也可以是機械、氣動或者液壓的。 3.2.5 安全策略 safety strategy 確保系統功能在特定環境、運行條件(如路面狀況、車輛狀態、交通參與者、天氣條件等)下安全運行的策略。 3.2.6 安全目標 safety goal 由危害分析和風險評估得出的最高層面的安全要求。 3.2.7 安全度量 safety metric 為符合安全目標而給定的具體技術參數的量化值(安全度量并非ASIL等級)。 3.28 安全措施 safety measures 活動或技術解決方案，用以避免或控制系統性失效、探測隨機硬件失效，控制隨機硬件失效或減輕它們的有害影響。 3.2.9 可控性 controllability 通過所涉及人員的及時反應，或通過外部措施的支持，避免特定的傷害或損傷的能力。 4 技術要求 4.1對汽車的要求 4.1.1 轉向系統應確保車輛在其最大設計車速范圍內轉向操縱的輕便性和安全性。轉向系統完好時的汽車的轉向操縱力、轉向時間、轉向半徑應滿足表1的要求。當按照5.2所要求的方法進行試驗時，在轉向系統完好的前提下，汽車應具有自動回正能力，如果車上安裝了輔助轉向裝置，還應滿足附錄A的要求。本標準所列的網周運動均指沿轉向網運動。 表1 轉向系統完好時轉向操縱力要求 車輛類別 轉向操縱力 N 轉向時間 s 轉向半徑 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 在汽車的最大設計速度范圍內，當駕駛員無異常轉向修正行為和轉向系統無異常振動時，不應因轉向系統影響汽車直線行駛性能。 4.1.3汽車轉向操縱的方向應與其行駛方向相一致，且轉向角應與轉向操縱裝置的偏轉連續對應。 對于ASE，本條款要求不適用。 對于全動力轉向系統，當車輛處于靜止時、或在車速不超過15 km/h的條件下行駛、或系統沒有啟動時，可以不必滿足本條款要求。 4.1.4轉向系統的設計、制造和裝配應能承受車輛或車輛組合正常使用狀態下的載荷，應保證在無需拆卸的情況下能夠借助常規的測量裝置、檢查方法或試驗方法檢查其工作狀態。除非專門設計，否則轉向傳動裝置的任何部分不應限制最大轉向角。 4.1.5 與汽車轉向相關的車輛電氣控制系統不得因電磁干擾而影響轉向功能，并應滿足GB 34660中的技術要求。 4.1.6轉向傳動系統中的可調節部件應能鎖止。 4.1.7汽車的轉向車輪不應僅是后車輪。 4.1.8轉向系統可以和其他系統共用同一能源供應。但如果任何與轉向系統共用相同能源的系統發生故障，轉向系統仍應滿足4.3中故障時的相關轉向功能。 4.1.9 轉向電子控制系統的功能安全要求，應按照GB/T 34590(所有部分)制定，并滿足附錄B的要求。 4.2對掛車的要求 4.2.1 當汽車列車向前直行，掛車應與牽引車行駛方向一致，如掛車無法自動保持直線行駛，應配備相應的調節裝置。 4.2.2半掛車的后車輪可以是轉向車輪。 4.2.3牽引車在水平路面上直線行駛，在最大設計速度范圍內.當駕駛員無轉向修正行為和轉向系統無異常振動時，掛車不應因其轉向系統影響車輛直線行駛性能。 4.2.4汽車列車以(25±1)km/h和5 km//h的車速勻速沿25 m半徑的轉向圓進行穩態轉向，分別測量掛車最后面的外邊緣所劃過的軌跡圓半徑，(25±1)km/h和5 km/h車速時的軌跡圓半徑之差應不大于0.7 m。 4.2.5汽車列車以25 km/h的速度駛離25 m半徑的轉向圓時，牽引車沿駛離起點為切點的切線40 m的范圍內(掛車尾端計)，掛車的任何部位在地面的投影都不得超出半徑25 m轉向圓的切線0.5 m，如圖1。繼續直線行駛，掛車應滿足4.2.3的規定。 注：掛車駛離轉向圓時的外擺值T≤0.5 m。 圖1 掛車駛離時外擺值要求 4.2.6對于具有多個轉向車軸的牽引桿掛車和半掛車以及至少有一個轉向車軸的中置軸掛車，應滿足4.2.3、4.2.4、4.2.5的規定。對于裝有隨動轉向裝置的掛車，滿載條件下，非轉向或自轉向的車軸與隨動轉向車軸之間的軸荷比至少應大于1，如非轉向或自轉向的車軸與隨動轉向車軸的軸荷比大于或等于1.6，則不必進行5.3的試驗。 4.2.7掛車轉向系統，如采用液壓轉向傳動，應滿足附錄C的要求。 4.2.8 向掛車轉向系統提供電能的汽車和利用汽車的電能實施轉向的掛車，應滿足附錄D的相關要求。 4.2.9掛車轉向傳動系統中的可調節部件應能鎖止。對于半掛列車，當需要斷開轉向傳動時，系統應設有鎖止機構，保證零部件的正確定位連接；如果采用自動鎖止，則應設置額外的手動鎖止機構。 4.2.10 與掛車轉向相關的車輛電氣控制系統不得因電磁干擾而影響轉向功能，并應滿足GB 34660中的技術要求。 4.3 失效規定 4.3.1 一般規定 4.3.1.1 轉向車輪、轉向操縱及轉向傳動機構的所有機械部件，應不易損壞，且易于維護，安全特性不低于安裝于車輛上的其他關鍵部件(如制動系統)。如果這些部件出現故障會使車輛失控，則這些部件應為金屬或具有同等特性材質制成，且在轉向系統正常下作時不得出現顯著變形。 4.3.1.2如果轉向系統存在故障，則假設任何時候都只存在一個故障，同一個轉向機構上的兩個車軸視為一個車軸。 4.3.1.3車輛即使出現轉向系統故障，也應滿足4.1.2、4.1.3的相應要求。 4.3.1.4除機械傳動機構外的任何傳動失效，應按4.4的規定提示駕駛員。當出現故障時，允許平均轉向傳動比出現變化，但不準許轉向操縱力超出表2所規定的值。