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JT/T 1358-2020 PDF in English


JT/T 1358-2020 (JT/T1358-2020, JTT 1358-2020, JTT1358-2020)
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JT/T 1358-2020: PDF in English (JTT 1358-2020)

JT/T 1358-2020
JT
TRANSPORTATION INUDSTRY STANDARD
OF THE PEOPLE’S REPUBLIC OF CHINA
ICS 43.080.20
T 42
Performance Requirements and Test Methods for
Lane Keeping Assist System of Bus
ISSUED ON: DECEMBER 30, 2020
IMPLEMENTED ON: APRIL 01, 2021
Issued by: Ministry of Transport of the PRC
Table of Contents
Foreword ... 3
Introduction ... 4
1 Scope ... 5
2 Normative References ... 5
3 Terms and Definitions ... 5
4 System Requirements ... 6
5 Test Method ... 10
Appendix A (Informative) Lane for Curved Line Test ... 14
Bibliography ... 15
Performance Requirements and Test Methods for
Lane Keeping Assist System of Bus
1 Scope
This Standard specifies the performance requirements and test methods for lane
keeping assist systems of bus.
This Standard is applicable to the lane keeping assist function (system) of Class-B and
Class-III M2, M3 categories of bus driving on road sections with standardized lane
markings.
2 Normative References
The following documents are essential to the application of this document. For the
dated documents, only the versions with the dates indicated are applicable to this
document; for the undated documents, only the latest version (including all the
amendments) is applicable to this document.
GB/T 3730.2 Road Vehicle – Masses - Vocabulary and Codes
GB 5768.3 Road Traffic Signs and Markings - Part 3: Road Traffic Markings
GB/T 15089 Classification of Power-Driven Vehicles and Trailers
GB/T 26773-2011 Intelligent Transport Systems - Lane Departure Warning
Systems - Performance Requirements and Test Procedures
JT/T 883-2014 Driving Danger Warning System for Commercial Vehicles -
Technical Requirements and Test Method
ISO 2575:2010 Road Vehicles – Symbols for Controls, Indicators and Tell-Tales
3 Terms and Definitions
For the purposes of this Document, the terms and definitions given in GB/T 3730.2,
GB 5768.3, GB/T 15089 and GB/T 26773 and the following apply.
3.1 Lane keeping assistance system
m/s (100 km/h) or the maximum design speed (the smaller value between the two).
4.2.2 The radius of curvature for the smallest bending line adapted to the LKAS shall
be no greater than 500m.
4.2.3 Allow different types of execution methods to achieve lane keeping assist
functions. Execution methods include controlling steering or braking, etc.
4.3 System status and switching
4.3.1 Status description
4.3.1.1 On and off of LKAS
When both the ignition switch and the LKAS switch are turned on and the system has
no faults, the system is turned on.
LKAS shall be turned off manually by the driver or automatically turned off by the
system. It can be turned off automatically when the ignition switch of the vehicle is
turned off; or the driver can turn it off manually through the "LKAS switch" [see the
requirements of item a) in 4.4.1].
4.3.1.2 Standby and activation of LKAS
After LKAS is turned on, the self-checking is normal, but when the system activation
conditions are not met, the system shall enter the standby state.
The conditions for LKAS activation shall at least include: detecting the markings of the
lane where the vehicle is on; determining the location of the subject vehicle in the lane,
and the subject vehicle speed in the normal operating range, etc. When all activation
conditions are met, the system shall automatically enter the activation state.
4.3.2 State switching process
The state switching process and necessary conditions of LKAS in the working process
are shown in Figure 1.
4.4 Alarm prompt
A lane departure warning prompt that meets the requirements of 5.4 in JT/T 883-2014
shall be provided.
4.5 Lane keeping
LKAS shall be designed so that the driver can use it safely in any state, and the vehicle
behaviour caused by lane keeping should be controlled. LKAS shall meet the following
operating restrictions:
4.8.1 The user manual shall specify the minimum vehicle speed required for system
operation and system failure conditions.
4.8.2 The user manual shall inform the driver of the conditions for system activation
and deactivation.
5 Test Method
5.1 Test conditions
5.1.1 Test environment conditions
The test environment requirements are:
a) Test location: asphalt or concrete pavement;
b) Ambient temperature: -20°C ~ 40°C;
c) The wind speed shall be less than or equal to 3 m/s;
d) The horizontal visibility range shall be greater than 1 km;
e) The visible lane markings on the test road shall be clearly marked, in good
condition, and comply with the provisions of GB 5768.3.
5.1.2 Test road-section conditions
The test road-section shall be dry and flat, with sufficient length to meet the
requirements of the test speed (no less than 20m/s) when the vehicle leaves the lane
at a low deviation speed.
The lane width of the test section is 3.75m; and the width and colour of the test lane
marking shall comply with the provisions of GB 5768.3.
5.1.3 Test vehicle conditions
The mass of the test vehicle shall be BETWEEN the curb weight of the vehicle plus
the total mass of the driver and the test equipment (the total mass of the driver and the
test equipment is 150kg) AND the maximum allowable total mass. The conditions of
the test vehicle shall not be changed after the start of the test.
5.2 Test content and procedures
5.2.1 Test items
Departure warning prompts and lane keeping tests on straight line and curved line.
the lane at a departure rate of 0.4 m/s ± 0.2 m/s; and then release the steering wheel,
make the subject vehicle deviate from the lane freely. A total of 8 tests were performed
in two groups (4 departures to the left in the first group and 4 departures to the right in
the second group).
The vehicle manufacturer shall give the shortest time interval between two consecutive
tests to avoid the unavailability of the lane keeping function.
5.2.4.2 Test judgment
During the single test process in each group, if the outer edge of the front tire on the
side of the subject vehicle deviates from the direction of the lane and the distance
across the lane boundary is no more than 1.1 m, the test is successful. If all 8 tests are
successful, the lane keeping function test on the straight line is qualified.
5.2.5 Test of lane keeping on curved line
5.2.5.1 Requirements for curved test line
The curved test line consists of a straight line and a curved line. The curved line is a
variable curvature curve; and the rate of curvature change shall be continuous and no
greater than 4 × 10-51/m2. For examples of test lanes on curved line, see Appendix A.
When the subject vehicle continues to drive near the centreline of the lane, the road
alignment of the curved line shall be able to ensure that the lateral acceleration of the
subject vehicle does not exceed 1.0 m/s2; or at least within the last 1s of the test, the
road alignment of the curved line shall ensure that the lateral acceleration of the vehicle
remains within the range of 0.5 m/s2 ~ 1.0 m/s2.
5.2.5.2 Test procedures
The test shall be carried out on a road that changes from a straight line to a curved
line. The vehicle speed shall be maintained at 20 m/s ± 0.5 m/s during the entire test
period.
On straight line, the subject vehicle shall be kept straight in the middle of the lane.
When the vehicle is stable, release the steering wheel before entering the curved line.
After the vehicle enters the curved line, the test time shall last for 5s.
The test shall be carried out for twice, once entering into the left curved line, and once
entering into the right curved line, as shown in Figure 3.
......
 
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.