Bullet train electromagnetic emergency braking system (emergency braking stage II)

Abstract

The invention discloses a bullet train electromagnetic emergency braking system, and belongs to the technical field of rail traffic safety. The system comprises a telescopic electromagnetic braking module, an intelligent control unit, an energy recovery module and a safety protection module. Reverse Lorentz force is generated through interaction of a superconducting coil and an orbit magnetic field to achieve braking, a Sigmoid function is adopted to control the current climbing rate, and in combination with a multi-physics field coupling protection structure, it is ensured that the acceleration change rate is smaller than or equal to 0.3 g / s when 1.5 MN braking force is generated within 0.5 s. The innovation points are as follows: (1) the folding multi-stage telescopic mechanism reduces the equipment volume by 40%; (2) 99.99% reliability is realized by a dual-redundancy control framework; (3) the energy efficiency of the energy recovery system is improved to 80%; and (4) the impact injury of personnel is reduced by 60% through a biomechanical protection strategy. The system can serve as an effective supplement of an existing braking system, and the emergency braking safety performance of the motor train unit is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of rail vehicle braking, and in particular to an EMU emergency braking system (abbreviated as emergency braking stage II) based on the principle of electromagnetic reaction force, which is suitable for a backup braking solution when conventional braking fails. Background Art

[0002] The existing EMU braking system mainly relies on air brakes and electric brakes, which have the following defects under extreme working conditions: 1. Braking response delay (traditional mechanical brake response time > 1 second) 2. The braking force of friction braking is limited by the wheel-rail adhesion coefficient (failure when μ < 0.3) 3. The instantaneous impact acceleration caused by emergency braking is greater than 3m / s², which can easily cause equipment damage and personal injury 4. Braking energy is dissipated in the form of heat energy, and the energy utilization rate is less than 20% Although some studies have attempted to apply electromagnetic braking technology to rail transit, there are problems such as severe magnetic field interference, nonlinear fluctuations in braking force, and excessive equipment size. The innovation of this invention lies in the realization of safe and reliable emergency braking through modular scalable structure design, superconducting material application and multi-physical field coupling protection technology. Summary of the invention

[0003] 1. System composition This system consists of four core modules: 1. Electromagnetic brake module ①Retractable titanium alloy arm (foldable multi-stage telescopic mechanism) equipped with superconducting coil assembly ②Current conduction device made of superconducting material (MgB2 wire) ③ Electromagnetic compatibility design of reverse Helmholtz coil layout 2. Intelligent control unit ① Dual redundant FPGA controller (compliant with ISO 26262 ASIL-D standard) ②Millimeter wave radar + fiber grating composite distance measuring device (±0.1mm accuracy) ③In-vehicle AI dynamic adjustment algorithm (based on LSTM neural network) 3. Energy recovery module ① On-board supercapacitor array (capacity ≥ 120kW·h) ②Regenerative braking feedback circuit (conversion efficiency > 85%) ③Liquid cooling system (heat dissipation power ≥ 3MW) 4. Security protection module ① Progressive force field loading device (Sigmoid function controls current climbing) ②Nanocrystalline alloy + copper mesh composite shielding layer (magnetic shielding efficiency > 40dB) ③ Diamond lattice stress waveguide structure (stress dispersion rate increased by 60%) 2. Working Principle When a normal brake failure is detected, the control unit completes the following actions within 0.5 seconds: 1. The electromagnetic coil group is deployed at a speed of ≥2m / s to the optimal working distance of 150-200mm from the track 2. Apply 0-3000V adjustable DC to generate 1.0-1.5MN reverse Lorentz force 3. Control the current curve through the Sigmoid function to make the acceleration change rate ≤ 0.3g / s 4. Real-time monitoring of seat pressure sensor data, dynamic adjustment of maximum deceleration ≤1.5m / s² 3. Innovation Advantages 1. Improved braking force: Peak braking force is 3 times that of traditional brakes (1.5MN vs 0.5MN) 2. Responsive acceleration: Braking start time is shortened by 60% (0.5 seconds vs. 1.3 seconds) 3. Energy cycle: 80% of kinetic energy is converted into electrical energy and fed back to the grid, increasing energy saving efficiency by 4 times 4. Security: ① The magnetic field strength inside the vehicle is ≤ 0.5μT (lower than the ICNIRP standard limit) ② Impact acceleration reduced by 50% (≤1.5m / s²) ③The stress waveguide structure makes the body deformation less than 3mm DETAILED DESCRIPTION

[0004] The following parameter combinations are used in the embodiment: 1. Superconducting coil group: 12 sets of double-layer Helmholtz coils, each set has an inductance of 25mH 2. Telescopic mechanism: TC4 titanium alloy arm + reaction sintered silicon carbide guide rail 3. Current control: segmented S-curve, initial slope ≤500A / ms 4. Energy recovery: supercapacitor bank (Maxwell 3.0V / 3000F monomer) 5. Safety protection: negative Poisson's ratio material (titanium alloy lattice structure with a porosity of 65%).

Claims

1. An electromagnetic emergency braking system for a motor vehicle, comprising: ① Electromagnetic brake module, installed on the roof of the power compartment at the front and rear of the vehicle, including a retractable electromagnetic coil group and a current conduction device made of superconducting material; ② A control unit is used to activate the electromagnetic brake module and control the braking force by adjusting the DC power intensity when a failure of the conventional brake system is detected; ③ Energy recovery module, used to feed back the electrical energy generated during braking to the on-board power grid or energy storage device; ④Safety protection module, including a progressive force field loading device and a multi-physical field coupling protection structure, which is used to reduce the impact on trains and personnel during braking.

2. The electromagnetic emergency brake system for a motor vehicle according to claim 1, characterized in that: The electromagnetic brake module generates braking force through the principle of electromagnetic reaction force, specifically including: ① The magnetic field between the electromagnetic coil group and the track or special induction plate interacts to generate a reverse Lorentz force; ②By adjusting the DC power intensity (0-3000V adjustable), a peak braking force of up to 1.5MN is generated within 0.3 seconds.

3. The electromagnetic emergency brake system for a motor vehicle according to claim 1, characterized in that: The control unit comprises: ① Dual redundant FPGA controller, supporting ISO 26262 ASIL-D functional safety; ② Real-time monitoring system, which is used to detect the status of the conventional braking system and activate the electromagnetic braking module within 0.5 seconds when failure is detected.

4. The electromagnetic emergency brake system for a motor vehicle according to claim 1, characterized in that: The energy recovery module comprises: ① On-board supercapacitor array, used to store electrical energy generated during braking; ② Regenerative braking feedback circuit, used to convert 80% of the kinetic energy into electrical energy and feed it back to the grid.

5. The electromagnetic emergency brake system for a motor vehicle according to claim 1, characterized in that: The security protection module comprises: ① Progressive force field loading device, using Sigmoid function to control the current climbing rate, ensuring that the acceleration change rate is ≤0.3g / s; ② Multi-physical field coupling protection structure, including nanocrystalline alloy + copper mesh composite shielding layer and hydraulic damper + negative Poisson's ratio material energy absorption structure.

6. The electromagnetic emergency brake system for a motor vehicle according to claim 1, characterized in that: The retractable structure of the electromagnetic brake module comprises: ① Titanium alloy telescopic arm and silicon carbide guide rail, deployment speed ≥ 2m / s; ② The foldable multi-stage telescopic mechanism is hidden in the roof air deflector when not in operation to reduce wind resistance.

7. The electromagnetic emergency brake system for a motor vehicle according to claim 1, characterized in that: The control unit also includes: ①Millimeter wave radar + fiber grating composite distance measuring device, used to monitor the distance between the electromagnetic coil group and the track in real time, with an accuracy of ±0.1mm; ②On-board AI algorithm, used to dynamically adjust the braking force curve to match the optimal braking effect.

8. The electromagnetic emergency brake system for a motor vehicle according to claim 1, characterized in that: The energy recovery module also includes: ① Liquid cooling system, used to dissipate the remaining 20% ​​of kinetic energy; ②Energy management unit, used to optimize power distribution and storage.

9. The electromagnetic emergency brake system for electric vehicles according to claim 1, characterized in that: The security protection module also includes: ① Biomechanical protection strategy, dynamically adjust the maximum deceleration through the seat pressure sensor + visual analysis system to ensure ≤1.5m / s²; ② Stress waveguide design: a diamond lattice structure is set on the vehicle body frame to guide the stress wave generated by the electromagnetic braking force to the longitudinal reinforcement beam.

10. The electromagnetic emergency brake system for a motor vehicle according to claim 1, characterized in that: The electromagnetic compatibility design of the electromagnetic brake module includes: ① The reverse Helmholtz coil layout makes the external magnetic field strength decay exponentially with distance; ②Electromagnetic shielding layer, ensuring the magnetic field strength inside the vehicle is ≤0.5μT, in line with ICNIRP standards.