Technical Requirements and Test Methods for Passenger Vehicle Braking Systems
Published by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China and the Standardization Administration of the People's Republic of China
Release Date: 2008-04-25
Effective Date: 2008-11-01
1. Scope
This standard specifies the structure, performance requirements, and test methods for passenger vehicle braking systems.
Applies to: M₁ category vehicles as defined in GB/T 15089.
2 - Normative References
- GB 4094: Symbols for controls, indicators, and signals
- GB/T 5620*: Road vehicle braking terminology (≡ ISO 611:1994)
- GB 12981: Motor vehicle brake fluid (≈ ISO 4925:1978)
- GB/T 17619*: EMC immunity for electronic components
- GB 18655: Radio disturbance suppression (≡ CISPR 25)
3. Critical Terminology & Definitions
Based on GB/T 5620 with additions
3.1 Core Brake System Terms
Vehicle Type ▸ Identical in:
- Max design mass • Axle load distribution • Top speed
- Brake type (e.g., trailer/E-brake compatibility)
- Axle count/layout • Engine type • Gear ratios
- Final drive ratio • Tire size
🔧Braking Equipment --Combination of components enabling:
- Vehicle deceleration/stopping
- Keeping stationary vehicle at rest,Comprises: Control + Transmission devices + Brakes
Control Device：Driver-operated component initiating braking energy (manual, powered, or hybrid).
⚙️Transmission Device --Mechanical/hydraulic/pneumatic/electric components linking control to brakes.
- Control Transmission: Manages brake operation
- Energy Transmission: Delivers force (includes accumulators)
🛑Brake Types
- Friction (mechanical resistance)
- Electric (electromagnetic force)
- Hydraulic (fluid resistance)
- Engine retarder (augmented engine braking)
📶Progressive Braking--Linear brake force modulation via driver input (monotonic function).
⚖️Loading States
- Unladen: Curb weight + 110 kg
- Laden: Max design mass (unless specified)
Axle/Wheel Load--Vertical static reaction force per axle/wheel at road surface.
- Max Static Load: Value at laden condition
3.1.14 Energy-Storing Hydraulic Brakes
Systems powered by pressurized fluid from accumulators (pressure limited per OEM specs).
3.1.16 Electric Regenerative Braking (RBS) ⚡
Kinetic energy → electrical energy conversion during deceleration.
- Type A: Independent of service brakes
- Type B: Part of service brakes
3.1.19-21 Advanced Braking Concepts
- Phased Braking: Priority activation for specific brakes
- Automatic Control: System-triggered braking without driver input
- Selective Braking: ECU-controlled individual wheel braking
3.1.23 Wheel Locking 🔒
Wheel rotation = 0 or 100% slip for:
- ≥100 ms (speed >15 km/h)
- ≥500 ms (ABS tests on low-μ surfaces)
3.1.25 Anti-lock Braking System (ABS) 🛡️
System preventing wheel lock by automatically modulating brake force.
Components:
- Sensors (wheel motion data)
- Controller (processes data → commands)
- Modulator (adjusts brake pressure)
3.1.29-30 Wheel Control Types
- Direct Control: Uses own sensor data
- Indirect Control: Uses other wheels' sensor data
3.1.31 Full Cycling
ABS repeatedly modulates force to prevent lockup (single adjustment ≠ full cycling).
3.1.32-33 Pressure Thresholds
- Cut-in: System replenishes energy
- Cut-out: Energy supply disconnects
3.2 Electronic Control Systems 💻
- Safety Concept: Fail-operational design (redundancy/backups)
- Complex Electronic Control: Hierarchical system with override capability
- Functional Boundary: Operational limits under control
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