WO2013134918A1

WO2013134918A1 - Urban tram braking system

Info

Publication number: WO2013134918A1
Application number: PCT/CN2012/072236
Authority: WO
Inventors: 崔晓军; 李培署; 王其伟; 许丰磊
Original assignee: 青岛四方车辆研究所有限公司
Priority date: 2012-03-13
Filing date: 2012-03-13
Publication date: 2013-09-19

Abstract

An urban tram braking system, comprising a brake instruction generation system, a brake control system and an anti-skid system; the brake control system comprises a brake electronic control unit (BECU) and a brake control unit (BCU); the brake instruction generation system transmits a brake instruction to the BECU; according to the brake instruction and the loading force detected by a loading pressure sensor, the BECU calculates and provides a required brake force to a traction control unit; the traction control unit feeds the dynamic brake force signal back to the BECU; the BECU calculates the air brake force to be replenished, and controls the BCU to generate brake cylinder pressure so as to achieve brake control; the brake instruction generation system is provided with a driver controller, an emergency brake switch and a logic control unit connected to the emergency brake switch; the anti-skid system comprises a speed sensor disposed on a wheel axle and an anti-skid exhaust valve located on a brake cylinder tube; the speed sensor detects and transmits a speed signal to the BECU; and the BECU controls the action of the anti-skid exhaust valve according to the speed signal.

Description

Urban tram brake system

Technical field

The present invention relates to a brake control device for an electric train, and more particularly to a tram brake system including a brake command generation system, a brake control system, and an anti-skid system.

Background technique

Looking at the world's modern big cities, all of them are based on the development of urban rail transit. Through the combination of urban rail transit and intercity rail transit, railway trunk passenger transport, highway passenger transport, port maritime transport, and air transport, the formation of a large-scale traffic network is a model of modern large-scale traffic and is also the development direction of China.

With the rapid development of the economy, China has begun to enter the accelerated development stage of urbanization and urban transportation. With its advantages of large volume, high efficiency and low pollution, urban rail transit has quickly become the primary choice for many large cities to solve traffic problems. In China, a diversified development trend based on subway, urban light rail and elevated light rail is formed. By the end of 2008, rail transit systems in more than 10 cities including Beijing, Shanghai, Tianjin, Guangzhou, Changchun, Dalian, Shenzhen, Wuhan, Nanjing, and Chongqing have been put into operation. Currently, rail transit projects in many cities are under construction. According to the rail transit planning of 15 cities in China, by 2010, China plans to build a new urban rail transit project with a total length of nearly 1,300 kilometers. The three cities of Beijing, Shanghai and Guangzhou plan to build rail transit at a speed of 40 kilometers per year. It is also rare. In addition to the increase in mileage, China's rail transit has also been diversified from the form of the subway, such as the Beijing Subway, Dalian Express Light and Tram, Chongqing's straddle monorail, and Shanghai's magnetic levitation.

As part of the modern urban rail transit, the tram has the characteristics of large capacity, low operating and construction costs, no pollution to the environment, fast and comfortable. The low-floor tram also has passengers up and down, and can even take care of the elderly. The characteristics of disabled people. As a supplement to the subway and evacuation vehicles, trams have received increasing attention. Dalian, Changchun and Tianjin have successively opened new trams. Beijing and Shanghai also plan to develop trams.

In urban rail transit vehicles, light rail vehicles such as trams are the most frequently used for braking and mitigation. They often perform braking and mitigation operations every few seconds, and in order to be able to stop at any time, The distance requirement is very short (the Dalian tram requires an emergency braking distance of 30m at a braking speed of 30km/h), which requires a very high sensitivity and very short idling time. At the same time, the tram uses a composite braking method, so it must have good air-electric combined braking performance. At the same time, there must be perfect backup braking measures, because trams are usually equipped with a brake control system. In the event of a fault, it means that the "all" brake system has failed, so there must be a perfect backup brake. Measures to guarantee parking.

Therefore, based on the characteristics of China's urban trams, I have developed a computer-controlled direct-energized air brake system.

Summary of the invention

It is an object of the present invention to provide a city tram brake system that has a composite braking mode, stable braking force, accurate accuracy, short idling time, short braking distance, and automatic adjustment of braking force according to changes in vehicle load.

The technical solution of the present invention is: an urban tram brake system, including a brake command generation system, a brake control system, and an anti-skid system, the brake control system including a microcomputer control unit BECU and an air brake unit The BCU, the brake command generating system issues a braking command to the microcomputer control unit BECU, and the microcomputer control unit BECU calculates the required braking force according to the braking command and the load force detected by the load pressure sensor, and supplies the traction control unit to the traction control unit. The dynamic braking force signal is fed back to the microcomputer control unit BECU, and the microcomputer control unit BECU calculates the air braking force that needs to be supplemented, controls the air brake unit BCU, generates the brake cylinder pressure, and realizes the brake control; the braking command occurs. The system is provided with a driver controller, an emergency brake switch and a logic control unit connected thereto; the anti-skid system includes a speed sensor disposed on the axle and a non-slip vent valve on the brake cylinder tube, and the speed sensor detects the speed The signal is transmitted to the microcomputer control unit BECU, and the microcomputer control unit BECU is controlled according to the speed signal. The action of the anti-skid exhaust valve.

Preferably, the air brake unit BCU comprises a wind source system, a pneumatic system and a brake cylinder, and the wind source system provides a wind source for the pneumatic system and the brake cylinder through the air duct;

Preferably, the pneumatic system comprises a brake storage cylinder, an air-to-air switching valve, an emergency valve, a weighing valve, a relay valve and a non-slip exhaust valve which are sequentially connected with the air duct, and the relay valve is also configured. The movable storage cylinder and the brake cylinder are connected, the air-to-air switching valve is connected to the emergency valve, the standby relief valve is connected to the control pipeline, and the weighing valve is connected to the air spring through the average valve; the pipeline is provided with a pressure sensor, a pressure sensor Detect wind pressure and transmit the signal to BECU, The BECU is connected to the air-to-air switching valve, the backup relief valve, the emergency valve, and the anti-skid exhaust valve, and controls their working state.

Preferably, the wind source system is provided with an air compressor.

Preferably, the urban tram brake system communicates with the monitoring unit, and the monitoring unit communicates with the microcomputer control unit BECU and the traction control unit via the 485 bus.

Preferably, the tram is a two-motor train plus a trailer group, two motor trains share a brake system, and one trailer uses a brake system.

Preferably, the microcomputer control unit BECU of the two sets of brake systems communicates via a CAN bus; the monitoring units of the two sets of brake systems communicate via a 485 bus.

The beneficial effects of the invention are as follows: (1) A microcomputer-controlled direct-energized air brake system is used.

(2) The composite braking method using dynamic braking and air braking, the power braking is preferred, and the dynamic braking can be automatically compensated when the dynamic braking cannot meet the braking demand. The air brake has good responsiveness to dynamic brake changes, and the response time is ≤0.2s.

(3) The main braking methods include common braking and emergency braking, and emergency braking is pure air braking.

(4) The braking force control during normal braking is stable and accurate. The braking force varies linearly from 1st to 7th and from 7th to 1st. The brake cylinder pressure difference of the same brake does not exceed ±10kPa. The brake response time is short, and the response time of the brake cylinder pressure change to the brake command is ≤0.2s.

(5) The emergency braking time is short, the brake cylinder pressure is increased from 0 to 90% of the maximum pressure ≤ 1 s; the time from the highest pressure to 10% of the maximum pressure is ≤ 2 s.

(6) The braking distance is short, and the emergency braking distance is ≤30m when the initial braking speed is 30km/h.

(7) The braking force can be automatically adjusted according to changes in vehicle load.

(8) It has fault diagnosis and fault information storage, display and communication functions.

DRAWINGS

Figure 1 is a schematic diagram of the present invention.

detailed description

The specific embodiments of the present invention are described below with reference to the accompanying drawings:

An urban tram brake system includes a brake command generation system, a brake control system, and an anti-skid system, the brake control system including a microcomputer control unit BECU and an air brake unit BCU, and a brake command generation system The brake command is issued to the microcomputer control unit BECU, and the microcomputer control unit BECU calculates the required braking force to be supplied to the traction control unit according to the braking command and the load force detected by the load pressure sensor, and the traction control unit feeds back the dynamic braking force signal to The microcomputer control unit BECU, the microcomputer control unit BECU calculates the air braking force that needs to be supplemented, controls the air brake unit BCU, generates the brake cylinder pressure, and realizes the brake control; the brake command generation system is provided with a driver controller, An emergency brake switch and a logic control unit connected thereto; the anti-skid system includes a speed sensor disposed on the axle and a non-slip vent valve on the brake cylinder tube, and the speed sensor detects the speed signal and transmits the signal to the microcomputer control unit BECU, the microcomputer control unit BECU controls the action of the anti-skid exhaust valve according to the speed signal.

The air brake unit BCU includes a wind source system, a pneumatic system and a brake cylinder, and the wind source system provides a wind source for the pneumatic system and the brake cylinder through the air duct;

The pneumatic system includes a brake storage cylinder, an air-to-air switching valve, an emergency valve, a weighing valve, a relay valve and an anti-skid exhaust valve which are sequentially connected with the air duct, and the relay valve and the brake air storage cylinder The brake cylinder is connected, the air-to-air switching valve is connected to the emergency valve, the standby relief valve is connected to the control pipeline, and the weighing valve is connected to the air spring through the average valve; the pipeline is provided with a pressure sensor, and the pressure sensor detects the wind pressure and Transfer the signal to BECU, The BECU is connected to the air-to-air switching valve, the backup relief valve, the emergency valve, and the anti-skid exhaust valve, and controls their working state.

The wind source system is provided with an air compressor.

The urban tram brake system communicates with the monitoring unit, and the monitoring unit communicates with the microcomputer control unit BECU and the traction control unit via the 485 bus.

The tram is a group of two motor vehicles plus one trailer, two motor cars share a brake system, and one trailer uses a brake system.

The microcomputer control unit BECU of the two sets of brake systems communicates via the CAN bus; the monitoring units of the two sets of brake systems communicate via the 485 bus.

The working process of the present invention is as follows:

The driver controller is the issuing device of the brake command, and the issued brake command is sent to the microcomputer control unit BECU of the motor car and the trailer.

The motor vehicle control unit BECU calculates the required braking force according to the braking command and the load condition, and supplies it to the traction control unit, and then calculates the air braking force that needs to be supplemented according to the dynamic braking force feedback signal, and controls the motor car. BCU, apply air brake. The trailer microcomputer control unit BECU calculates the required braking force according to the braking command and the load condition, controls the trailer BCU, and applies air brake.

The air brake control unit BCU converts the air pressure from the brake storage cylinder into a pre-control pressure corresponding to the analog signal through the air-to-air switching valve according to the electronic analog braking force signal transmitted from the microcomputer control unit BECU, and then pre-controls The pressure reaches the weighing valve through the emergency valve, and is detected and restricted by the weighing valve. The pre-control pressure from the weighing valve to the relay valve opens the passage of the brake storage cylinder and the brake cylinder in the relay valve. Finally, The brake cylinder is given an air pressure that meets the braking force requirements. During emergency braking, the pre-control pressure is not controlled by the air-to-air switching valve. The compressed air from the brake storage cylinder directly reaches the weighing valve via the emergency valve. The pre-control pressure is only controlled by the weighing valve; if the emergency valve fails, Then, according to the emergency braking force set by the microcomputer control unit BECU, the pre-control pressure is controlled by the air-to-air switching valve to perform emergency braking.

When the microcomputer control unit BECU issues a mitigation command, the exhaust valve of the BCU hollow electric switching valve is energized and opened, the intake valve is blocked, the pre-control pressure is exhausted through the exhaust valve, the diaphragm of the BCU relay valve moves, and the storage cylinder is cut off. The brake cylinder passage opens the passage between the brake cylinder and the atmosphere, and the brake cylinder exhausts the atmosphere.

The braking mode of the present invention includes common braking and emergency braking, and the composite braking using dynamic braking (regenerative braking) and air braking during normal braking, and only air braking in emergency braking.

1, braking mode

Braking modes include common braking, emergency braking, and common braking and emergency braking are completely separate. The emergency brake is a pure air brake.

1.1 common brake

Commonly used brakes are the speed at which the vehicle is operating in normal operation and the brake applied each time it enters the station. The braking force can be automatically adjusted according to the vehicle load change during the braking process; the braking process has an anti-impact restriction function.

In the common braking process, when the dynamic brake can not meet the braking force demand, the air brake can automatically compensate, and the total braking force should meet the braking force demand.

The common brake is a 7-stage brake, controlled by the driver controller.

(1) Dynamic braking

In the common braking, the composite brake with dynamic braking and air braking is adopted, and the dynamic braking adopts regenerative braking, which is controlled by the traction control unit according to the braking command value provided by the microcomputer control unit BECU, and the command value is based on the vehicle load. Make compensation, The microcomputer control unit BECU obtains a brake command signal (level 7) from the command line.

(2) Composite brake

When the braking force demand exceeds the dynamic braking capacity, the insufficient braking force is supplemented by the air brake.

The actual dynamic braking force is fed back to the microcomputer control unit BECU by the traction control unit in the form of a PWM signal.

The microcomputer control unit BECU calculates a difference between the braking force command and the actual power braking force, and applies a corresponding air braking force based on the difference.

(3) Switching of air brake during common braking

If the dynamic brake is turned off, it is switched to air brake according to the brake command, and the switching process satisfies the total braking force demand.

1.2 emergency braking

Emergency braking is the braking that is implemented to stop the vehicle as soon as possible when the vehicle encounters an emergency or other unexpected situation. Only air brakes are used, which cannot be relieved before parking.

Emergency braking occurs under the following conditions:

(1) The driver moves the brake handle to the emergency position.

(2) Press the emergency switch or accidentally remove the bow.

(3) The total wind pressure is too low (less than 5 bar).

(4) Loss of power or loss of power in the emergency brake circuit.

2.1 Adjust the braking force according to the load change

In the case of common braking, the load pressure sensor installed in the air spring system detects the load signal and transmits it to the microcomputer control unit BECU in analog form. The microcomputer control unit BECU automatically adjusts the braking force according to the load change, and the microcomputer control unit BECU will load the load signal. Transfer to the traction control unit. During emergency braking, the braking force is adjusted by the weighing valve.

(1) Load signal to the microcomputer control unit BECU

A load pressure sensor mounted in the air spring system detects the load signal. The pressure sensor transmits the analog signal of 4~20mA to the microcomputer control unit BECU, and the corresponding pressure range is 0~10bar.

The load signal is detected at each station stop and is stored when the vehicle is restarted.

The microcomputer control unit BECU performs load compensation of the air brake according to the load, and the total vehicle weight calculated based on the deceleration command of the driver controller is the sum of the actual weight of the vehicle (measured by the pressure sensor) plus the rotation mass.

The required total braking force is obtained by multiplying the total weight of the vehicle by the required deceleration.

Braking power = brake command (driver controller) × (total vehicle weight + vehicle rotation quality)

monitor:

The load signal UT is monitored by comparing with the upper and lower limits of the load in the parking state. If the limit value is exceeded, it indicates a fault, and in the fault state:

The lower limit is 0.7×ULmin, ULmin=empty weight (AW0)

The upper limit is 1.2 x ULmax, and ULmax = overload weight (AW3).

The load sensor signal UL is continuously monitored by comparison with the upper and lower limits. If the following values are exceeded, it indicates that the sensor is faulty. In the fault state, the load sensor signal UL<4mA or UL>20mA.

When the load sensor signal fails, it is replaced by the load AW2.

(2) Load signal to the traction control unit

The load signal to the traction control unit is calculated at the microcomputer control unit BECU and does not include the rotational mass. The traction control unit only needs this load.

The signal is a PWM signal with a voltage of DC22±3V and a frequency of 500±10 Hz. The duty ratio is 0 to 10 t = 10%, and 50 t = 80%.

If the load signal transmitted to the traction control unit is interrupted, the AW2 load is taken.

2.2 Impulse restriction function

The anti-impact limit of the braking force is commonly used during braking, and the rate of change of the control deceleration does not exceed 0.75 m/s3.

2.3 composite brake control

(1) Brake command for dynamic braking

The brake command for dynamic braking is calculated by the microcomputer control unit BECU and transmitted to the traction control unit.

PWM signal, voltage DC22±3V, frequency 500±10Hz,

Duty cycle 0kN = 10% PWM, 50kN = 80% PWM.

The microcomputer control unit BECU output signal is supplied by the traction control unit with a voltage of DC22±3V.

The load compensation is based on the total weight and the corresponding dynamic braking force requirements are:

Dynamic braking force = braking command × (total vehicle weight + rotating mass)

When the emergency brake line is open or the dynamic brake is faulty, the dynamic brake feedback signal represents a braking force of zero. At this time, the dynamic brake is replaced by an air brake.

(2) Dynamic brake feedback value

The dynamic brake PWM feedback signal represents the amount of braking force that the dynamic brake can provide, and is transmitted from the traction control unit to the microcomputer control unit BECU.

PWM signal, voltage 22±3VDC, frequency 500±10Hz,

Duty cycle 0kN = 10% PWM, 50kN = 80% PWM.

(3) Regenerative braking and air brake smooth conversion

During the conversion process of regenerative braking and air braking, the total braking force and deceleration are kept in agreement with the braking command to achieve a smooth transition between the two.

2.4 brake cylinder pressure initial jump

In order to coordinate with the regenerative braking and reduce the brake idling time, the brake cylinder pressure first jump function is provided, that is, as soon as a common brake command is generated, the brake cylinder jumps and maintains an initial pressure, just overcoming the brake The cylinder relieves the spring force, so that when the air brake is combined with the regenerative braking, the coordination performance of the two can be improved, and the delay time generated by the air braking force is reduced, and the idle time is shortened.

2.5 brake cylinder pressure hysteresis correction

The brake cylinder pressure is controlled by the relay valve. Due to the characteristics of the relay valve itself, when the brake is relieved or the brake is relieved, it is easy to cause the brake cylinder pressure under the same brake command to be different, which affects the control accuracy. Therefore, corresponding corrective measures are taken to make the brake cylinder pressure formed by the same brake command value the same during braking and mitigation.

2.6 Communication function

The microcomputer control unit BECU can realize two kinds of communication methods, RS232 local communication and RS485 remote communication.

(1) RS232 local communication

RS232 is used for local communication with the host computer (PC) to realize the test detection function.

(2) RS485 remote communication

RS485 is used for remote communication with the vehicle monitoring device (Monitor) to realize online network monitoring.

In the case of the vehicle, the 485 serial port communicates with the vehicle monitor according to the communication protocol. Every 200 ms, the Monitor requests the microcomputer control unit BECU to receive the brake system status information or to request the fault history data stored by the microcomputer control unit BECU. Monitor can display the braking system dynamic information in real time, and can also query the latest four types of faults and their braking status information at the adjacent moments.

The microcomputer control unit BECU transmits the brake system status information to the Monitor according to the periodic status request command of the Monitor. The microcomputer control unit BECU records the brake system state information 1 second (50 ms interval) 3 seconds after the failure time at the time of the failure occurrence. Brake system status information at any 50 ms time in the fault data, as described above. This information also includes: fault code, when the fault occurred. After the microcomputer control unit BECU receives the fault history request information transmitted by the Monitor, it returns a specified fault information data record.

The upper computer can simulate the communication between the monitor and the 485 port of the BECU of the microcomputer control unit through the 485-transfer interface to complete the above functions.

2.7 Monitoring and failure assessment

The monitoring function is completed by each circuit board and peripheral components such as solenoid valves, pressure sensors, emergency brake valves and pressure switches inside the microcomputer control unit BECU. The fault information can be displayed and communicated with the monitoring device.

Claims

1. An urban tram brake system includes a brake command generation system, a brake control system, and an anti-skid system, wherein the brake control system includes a microcomputer control unit BECU and an air brake unit BCU. The motion command generation system issues a brake command to the microcomputer control unit BECU, and the microcomputer control unit BECU calculates the required braking force to be supplied to the traction control unit according to the braking command and the load force detected by the load pressure sensor, and the traction control unit drives the power system. The power signal is fed back to the microcomputer control unit BECU, and the microcomputer control unit BECU calculates the air braking force that needs to be supplemented, controls the air brake unit BCU, generates the brake cylinder pressure, and realizes the brake control; the brake command generation system is provided with a driver controller, an emergency brake switch, and a logic control unit connected thereto; the anti-skid system includes a speed sensor disposed on the axle and a non-slip vent valve on the brake cylinder tube, and the speed sensor detects the speed signal and transmits To the microcomputer control unit BECU, the microcomputer control unit BECU controls the defense according to the speed signal Operation of the exhaust valve.

2. The urban tram brake system according to claim 1, wherein said air brake unit BCU comprises a wind source system, a pneumatic system and a brake cylinder, and the wind source system is a pneumatic system through the air duct. The moving cylinder provides a source of wind.

3. The urban tram brake system of claim 2, wherein the pneumatic system comprises a brake storage cylinder, an air-to-electricity switching valve, an emergency valve, a weighing valve, and a pneumatic switch. Relay valve and anti-skid exhaust valve, relay valve is also connected with brake storage cylinder and brake cylinder, air-to-air switching valve is connected to emergency valve, spare relief valve is connected to control line, and weighing valve passes through average valve It is connected to the air spring; a pressure sensor is arranged on the pipeline, and the pressure sensor detects the wind pressure and transmits the signal to the BECU. The BECU is connected to the air-to-air switching valve, the backup relief valve, the emergency valve, and the anti-skid exhaust valve, and controls their working state.

4. The urban tram brake system of claim 1 wherein said wind source system is provided with an air compressor.

5. The urban tram brake system according to claim 1, wherein said urban tram brake system communicates with a monitoring unit, and the monitoring unit communicates with the microcomputer control unit BECU and the traction control unit via the 485 bus. .

6. The urban tram brake system according to any one of claims 1 to 5, characterized in that: the tram is two motor vehicles plus one trailer group, and two motor cars share a brake system. A trailer uses a brake system.

7. The urban tram brake system according to claim 6, wherein the microcomputer control unit BECU of the two sets of brake systems communicates via a CAN bus; and the monitoring units of the two brake systems pass between 485 bus communication.