ICS 43.040.40
CCS T 24
National Standard of the People’s Republic of China
GB/T 13594-2025
Replaces GB/T 13594-2003
Performance requirements and test methods of anti-lock braking system for commercial vehicle and trailer
(English Translation)
Issue date: 2025-04-25 Implementation date: 2025-08-01
Issued by the State Administration for Market Regulation of the People's Republic of China
the Standardization Administration of the People's Republic of China
Contents
Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols
5 Classification
6 Performance requirements and test methods
7 Test procedures
Annex A (Normative) Adhesion coefficient utilization ratio
Annex B (Normative) Braking performance on road surfaces (split-mu road surfaces) with different adhesion coefficients 21
Annex C (Normative) Selection method of road surfaces with low adhesion coefficients
Annex D (Informative) Test procedure for vehicles fitted with ABS
Bibliography
Performance requirements and test methods of anti-lock braking system for commercial vehicle and trailer
1 Scope
This document specifies the classification and performance requirements of anti-lock braking systems (hereinafter referred to as “ABS”) for commercial vehicles and trailers, and describes the test methods and test procedures of ABSs.
This document is applicable to Category M2, Category M3, Category N and Category O vehicles equipped with ABSs in accordance with the requirements of GB/T 15089.
2 Normative references
The following documents contain requirements which, through reference in this text, constitute provisions 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 4094 Symbols for controls, indicators and tell-tales of motor vehicles
GB/T 5620 Road vehicles - Braking of automotive vehicles and their trailers - Vocabulary
GB 12676-2014 Technical requirements and testing methods for commercial vehicle and trailer braking systems
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 34660 Road vehicles - Requirements and test methods of electromagnetic compatibility
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 5620 and the following apply.
3.1
full cycling
an ABS repeatedly adjusts the braking force to prevent directly controlling the control state of wheels locking
Note 1: This definition is not applicable to one-time adjustment performed during braking to stop.
Note 2: For air-braked trailers, ABS may be confirmed as full cycling only when the pressure directly controlled at each brake chamber of the wheel exceeds the maximum cycle pressure by 0.1 MPa during the whole braking process.
4 Symbols
For the purposes of this document, the following symbols apply.
E: Wheel base.
ER: The distance between the traction pin and the center of the semi-trailer axle or each axle (or the distance between the hook and the center of the mid-axle trailer axle or each axle).
F: Force.
FbR: The braking force of the trailer ABS when it's not working.
FbRAL: The braking force of the trailer ABS when it's working.
FbRmax: The maximum value of FbR.
FbRmaxi: The FbRmax when the i-th axis of the trailer is braked.
FCd: The total of static normal reaction forces acted by the road surface on the unbaked drive wheels of the train.
FCnd: The total of static normal reaction forces acted by the road surface on the unbaked driven wheels of the train.
Fdyn: The dynamic normal reaction force of the road surface when ABS works.
Fi: The static normal reaction force acted by the road surface on the i-th axis.
Fidyn: Fdyn on the i-th axle of the commercial vehicle or full-trailer.
FM: The total of static normal reaction forces acted by the road surface on the wheels of the vehicle or tractor.
FMd: The total of static normal reaction forces acted by the road surface on the unbaked drive wheels of the vehicle.
FMnd: The total of static normal reaction forces acted by the road surface on the unbaked driven wheels of the vehicle.
FR: The total of static normal reaction forces acted by the road surface on the wheels of the trailer.
FRdyn: The total of dynamic normal reaction forces acted by the road surface on the wheels of the semi-trailer or mid-axle trailer when braking.
FWM: 0.01FMnd+0.015FMd.
g: The gravitational acceleration, taking 9.81 m/s2.
h: The height of mass center specified by the manufacturer and approved by the technical division conducting the verification test.
hD: The height of the drawbar (height of trailer hook).
hk: The height of the saddle (king pin).
hR: The height of mass center of the trailer.
k: The adhesion coefficient between the tyre and the road surface.
kf: The k value of one front axle.
kH: The k value measured on a road surface with a high adhesion coefficient.
ki: The k value measured on the i-th axis of the vehicle equipped with Class 3 ABS.
kL: k value measured on a road surface with a low adhesion coefficient.
klock: The adhesion coefficient when the slip rate is 100%.
kM: The k value of the vehicle.
kpeak: The maximum value of the "adhesion coefficient - slip rate" curve.
kr: The k value of one rear axle.
kR: The k value of the trailer.
P: The mass of the single vehicle.
R: The ratio of kpeak and klock.
t: The time interval.
tm: The average of t.
tmin: The minimum of t.
z: The brake strength.
zAL: The brake strength (z) of the vehicle when the ABS works.
zC: The brake strength (z) of the train when only the trailer brakes but the ABS does not work.
zCAL: The brake strength (z) of the train when only the trailer brakes and the ABS works.
zCmax: The maximum of zC.
zCmaxi: The maximum of zC when the i-th axis of trailer is braked.
zm: The average brake strength.
zmax: The maximum of z.
zMALS: zAL for the split-mu road surface.
zR: The brake strength (z) of the trailer when the ABS does not work.
zRAL: zAL when the tractor does not brake, the engine is disengaged, and all the axles of the trailer are braked.
zRALH: zRAL measured on a road surface with a high adhesion coefficient.
zRALL: zRAL measured on a road surface with a low adhesion coefficient.
zRALS: zAL for the trailer on the split-mu road surface.
zRH: zR measured on a road surface with a high adhesion coefficient.
zRHmax: The maximum of zRH.
zRL: zR measured on a road surface with a low adhesion coefficient.
zRLmax: The maximum of zRL.
zRmax: The maximum of zR.
ε: the adhesion coefficient utilization ratio, as the quotient of the largest brake strength (zAL) and the adhesion coefficient (k) when the ABS works.
εH: ε value measured on a road surface with a high adhesion coefficient.
εi: ε value measured on the i-th axis of the vehicle equipped with Class 3 ABS.
εL: ε value measured on a road surface with a low adhesion coefficient.
Note: FMnd and FmdMd for two-axle vehicles are simplified to Fi.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols
5 Classification
6 Performance requirements and test methods
7 Test procedures
Annex A (Normative) Adhesion coefficient utilization ratio
Annex B (Normative) Braking performance on road surfaces (split-mu road surfaces) with different adhesion coefficients
Annex C (Normative) Selection method of road surfaces with low adhesion coefficients
Annex D (Informative) Test procedure for vehicles fitted with ABS
Bibliography
