Rail brake control method and system and rail transit vehicle

Abstract

This invention provides a magnetic track braking control method and system, as well as a rail transit vehicle. The magnetic track braking control method includes: Step A: From time t1 to time t1+ΔT1, controlling the current of the magnetic track braking electromagnet, causing the magnetic track braking electromagnet to move towards the track with uniform acceleration; Step B: From time t1+ΔT1 to time t1+ΔT1+ΔT2, controlling the current of the magnetic track braking electromagnet, causing the magnetic track braking electromagnet to move towards the track with uniform deceleration, and making the velocity of the magnetic track braking electromagnet 0 at time t1+ΔT1+ΔT2; wherein: ΔT1+ΔT2 is the time required from receiving the magnetic track braking command to the braking element contacting the track, and is a preset value; ΔT1 is a predetermined first time interval, and ΔT2 is a predetermined second time interval.

Description

Technical Field

[0001] This invention relates to a magnetic track braking control method and system, and more particularly to a method for controlling the electromagnet current in magnetic track braking control. This invention belongs to the field of magnetic track braking control systems and current control methods. Background Technology

[0002] Magnetic track braking is a technology that uses the friction between a magnetic track electromagnet (or simply electromagnet) and the track to achieve braking. During braking, the electromagnet on the levitation frame is lowered, and the attractive force between the electromagnet and the track generates significant friction, thus slowing the train down and achieving the braking effect. The advantages of magnetic track braking are that its braking force is not affected by the wheel-rail adhesion coefficient, allowing it to work effectively even with insufficient adhesion. Furthermore, due to its large friction area, its braking efficiency is far higher than that of traditional mechanical braking.

[0003] Currently, magnetic track braking systems control the current to the electromagnet by switching relays on and off. This method cannot precisely control the current input to the electromagnet, resulting in a high instantaneous velocity when the electromagnet contacts the track. This causes a significant braking impact on both the vehicle and the track. The resulting enormous inertial force disrupts the force balance of the suspension system, leading to fluctuations or even instability in the suspension gap. This can easily exacerbate vehicle vibrations, posing a safety hazard. Summary of the Invention

[0004] The problem this invention aims to solve is that the instantaneous speed of the magnetic track braking electromagnet when it comes into contact with the track is relatively high, resulting in a large impact on the vehicle and the track. The invention provides a magnetic track braking control method.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A magnetic track braking control method, characterized in that it includes: Step A: From time t1 to time t1+ΔT1, control the current of the magnetic rail braking electromagnet (1) so that the magnetic rail braking electromagnet (1) moves toward the track (6) with uniform acceleration; Step B: From time t1+△T1 to time t1+△T1+△T2, control the current of the magnetic rail braking electromagnet (1) so that the magnetic rail braking electromagnet (1) moves toward the track (6) with uniform deceleration, and so that the speed of the magnetic rail braking electromagnet (1) is 0 at time t1+△T1+△T2. Wherein: △T1+△T2 is the time required from receiving the magnetic track braking command to the braking component (3) contacting the track, and is a preset value; △T1 is a predetermined first time interval, and △T2 is a predetermined second time interval.

[0006] Based on the same inventive concept, the present invention also provides a magnetic track braking control system, including a computer device or processor; the computer device or processor is configured or programmed to perform the steps of the magnetic track braking control method.

[0007] Based on the same inventive concept, the present invention also provides a rail transit vehicle, including the aforementioned magnetic track braking control system.

[0008] According to the technical solution of the present invention, the instantaneous speed of the magnetic rail braking electromagnet when it contacts the track is reduced; the impact of the magnetic rail braking process on the vehicle and the track is reduced; that is, the vertical impact generated when the magnetic rail braking electromagnet contacts the track and the impact on the vehicle are reduced to a certain extent. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 This is a block diagram of a magnetic track braking system according to an embodiment of the present invention; Figure 2 The magnetic track braking controller scheme design diagram of this invention mainly consists of a control circuit board, a chopper, and a connector.

[0011] Figure 3 This is a topology diagram of the control circuit board according to an embodiment of the present invention; Figure 4 This is a chopper topology diagram according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of the magnetic rail braking electromagnet and the track in an embodiment of the present invention.

[0012] Figure 6 The speed-time curve and gap-time curve of the magnetic rail braking electromagnet are shown in the embodiment of the present invention.

[0013] Figure 7 The following are characteristic curves of the current and electromagnetic force of the magnetic rail braking electromagnet under different gap values ​​obtained in the embodiments of the present invention; wherein, (a) is a three-dimensional surface schematic diagram reflecting the relationship between electromagnetic force, current and gap, and (b) is the relationship curve of electromagnetic force and current under different gaps.

[0014] Figure 8 The current of the magnetic rail braking electromagnet from time t2 to the time of receiving the braking release command is obtained in an embodiment of the present invention. I With time t The relationship curve.

[0015] In the above attached diagram: 1. Magnetic rail braking electromagnet; 2. Return spring; 3. Braking component (can be brake pad); 4. Stop washer; 5. Stop nut; 6. Rail; 61. Rail contact surface; 7. Suspension frame; 8. Limiting component; 9. Connecting rod. Detailed Implementation

[0016] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0017] This embodiment provides a magnetic track braking control method, including: Step A: From time t1 to time t1+ΔT1, control the current of the magnetic rail braking electromagnet 1 so that the magnetic rail braking electromagnet 1 moves toward the track 6 with uniform acceleration. Step B: From time t1+△T1 to time t1+△T1+△T2, control the current of the magnetic rail braking electromagnet 1 so that the magnetic rail braking electromagnet 1 moves toward the track 6 with uniform deceleration, and makes the speed of the magnetic rail braking electromagnet 1 0 at time t1+△T1+△T2. Wherein: △T1+△T2 is the time required from receiving the magnetic track braking command to the braking component (3) contacting the track, and is a preset value; △T1 is a predetermined first time interval, and △T2 is a predetermined second time interval.

[0018] In this invention, the values ​​of ΔT1 (the time of the acceleration phase) and ΔT2 (the time of the deceleration phase) can be predetermined according to the actual scenario, as those skilled in the art will understand; preferably, ΔT1 > ΔT2. When the magnetic track braking command is received at time t1, the current is controlled from time t1 to time t1+ΔT1, causing the magnetic track braking electromagnet 1 to move towards the track 6 with uniform acceleration, thereby allowing the magnetic track braking electromagnet 1 to quickly approach the track. The magnetic track braking electromagnet 1 reaches its maximum speed at time t1+ΔT1. After the uniform acceleration phase, from time t1+ΔT1 to time t1+ΔT1+ΔT2, the current is controlled, causing the magnetic track braking electromagnet 1 to move towards the track 6 with uniform deceleration. That is, during this process, the magnetic track braking electromagnet 1 starts to decelerate from its maximum speed, so that the speed is 0 when the braking element of the magnetic track braking device contacts the track, reducing the impact on the track.

[0019] Furthermore, the magnetic track braking control method also includes: Starting from time t1+△T1+△T2, the current controlling the magnetic rail braking electromagnet 1 is not less than the second preset current threshold I.th_1 Until a brake release command is received; When a brake release command is received, the current of the control magnetic rail brake electromagnet 1 is 0A; Among them, I th_1 The range of values ​​is [I max ×p1, I max The first proportionality coefficient p1 ranges from [80%, 100%). max The maximum current value is set for the magnetic rail braking electromagnet (1).

[0020] Furthermore, the rail vehicle body is connected to the bottom end of the return spring 2, the top end of the return spring 2 is connected to the connecting rod 9, and the connecting rod 9 extends downward to below the bottom end of the return spring 2, thereby connecting to the magnetic rail braking electromagnet 1. The bottom end of the magnetic rail braking electromagnet 1 is connected to a braking element 3 for contacting the rail 6.

[0021] Figure 5 This is a schematic diagram of the magnetic track braking electromagnet used in this embodiment of a maglev vehicle. Figure 5 As shown, the suspension frame 7 of the maglev vehicle is installed on the vehicle body (not shown in the figure). The suspension frame 7 is fixed with a limiting member 8; the bottom end of the return spring 2 is fixed to and limited by the limiting member 8; the top end of the return spring 2 is fixedly connected to a stop washer 4; the return spring 2 is sleeved on the outside of the connecting rod 9, and the connecting rod 9 passes through the stop washer 4, the return spring 2, and the limiting member 8 in sequence before extending below the spring, thus being fixedly connected to the magnetic track braking electromagnet 1. A stop nut 5 is provided on the side of the stop washer 4 away from the return spring 2, sleeved on the outside of the connecting rod 9 and abutting against the stop washer 4, thereby connecting the upper part of the connecting rod 9 to the top end of the return spring 2.

[0022] When the magnetic rail brake electromagnet 1 moves up and down, it drives the connecting rod 9, the stop washer 4, and the top of the return spring 2 to move up and down together, thereby causing the return spring 2 to extend or shorten.

[0023] In the initial state, the gravity of the components connected to the top of the return spring 2 (including the connecting rod 9, the magnetic rail braking electromagnet 1, the braking element 3, etc.) causes the return spring 2 to be in its initial state (initial compressed state). At this time, the deformation of the return spring 2 is the initial deformation. x 0, at this point the gap between brake element 3 and track 6 is the initial gap. δ 0. When the magnetic rail braking electromagnet 1 moves downwards until the braking element 3 contacts the rail 6, the deformation of the return spring 2 reaches its maximum. The difference between the maximum deformation and the initial deformation of the return spring 2 is the stroke of the return spring 2, which is also equal to the initial clearance. δ 0.

[0024] When applied to maglev vehicles, track 6 can be as follows: Figure 5 The F rail is shown. Braking element 3 can be a brake pad.

[0025] It should be noted that this solution is applicable not only to maglev vehicles but also to conventional rail vehicles. When applied to conventional rail vehicles, Figure 5 The F track in the text can be replaced with the corresponding track. Figure 5 The suspended frame 7 in the middle can be replaced with the bogie of a regular vehicle.

[0026] Furthermore, based on the expressions for the electromagnetic force from time t1 to time t1+ΔT1 and the gap from time t1 to time t1+ΔT1, and based on the predetermined relationship between the gap, electromagnetic force, and current of the magnetic rail braking electromagnet 1, the required current of the magnetic rail braking electromagnet 1 from time t1 to time t1+ΔT1 is obtained. Based on the expressions for the electromagnetic force from time t1+△T1 to time t1+△T1+△T2, the expression for the gap from time t1+△T1 to time t1+△T1+△T2, and based on the predetermined relationship between the gap, electromagnetic force, and current of magnetic rail braking electromagnet 1, the required current of magnetic rail braking electromagnet 1 from time t1+△T1 to time t1+△T1+△T2 can be obtained. The gap is the gap between the brake element 3 and the track 6, and the electromagnetic force is the electromagnetic force generated by the magnetic track braking electromagnet 1.

[0027] The relationship between the gap, electromagnetic force, and current of the magnetic rail braking electromagnet 1 can be obtained by adjusting the gap and the current of the magnetic rail braking electromagnet 1, measuring the electromagnetic force under different gap-current combinations, and thus obtaining the relationship between the gap, electromagnetic force, and current of the magnetic rail braking electromagnet 1.

[0028] In one embodiment, the relationship between the gap, electromagnetic force, and current of the magnetic rail braking electromagnet 1 is a surface fitted in the oxyz coordinate system, where the ox axis represents the current of the magnetic rail braking electromagnet 1, the oy axis represents the electromagnetic force, and the oz axis represents the gap.

[0029] In another implementation, the relationship between the gap, electromagnetic force, and the current of the magnetic rail braking electromagnet 1 is presented in tabular form, as shown in Table 1 below. In practice, sampling points can also be supplemented using existing interpolation methods to improve data density.

[0030] Of course, more measurement points can be collected during the measurement to obtain a more accurate relationship.

[0031] The relationship between current I, gap δ, and electromagnetic force F is represented by the function f, then I = f(δ, F); where the current can be obtained through the I-δ-F diagram by looking up a table and interpolation.

[0032] Table 1 shows the actual relationship between the gap, electromagnetic force, and current. In Table 1, the unit of current I is A, the unit of electromagnetic force F is kN, and the unit of gap is... δ The unit is mm.

[0033] Furthermore, the expression for the electromagnetic force from time t1 to time t1+ΔT1 is: ; The method for calculating the expression for the time interval from time t1 to time t1+ΔT1 is as follows: ; in: F tu The electromagnetic force generated by the magnetic rail braking electromagnet 1 at time tu; δ tu Let tu be the gap between the brake element 3 and the track 6 at time tu; tu represents time tu, and the value range of tu is t1≤tu≤t1+△T1; M Let the mass of the magnetic rail braking electromagnet 1 be ; a 加 The vertical acceleration of the magnetic rail braking electromagnet 1 from time t1 to time t1+ΔT1; g It is the acceleration due to gravity; K Stiffness of the reset spring 2; x 0 represents the initial deformation of the reset spring 2; δ 0 represents the initial gap between the braking element 3 and the track 6; Preferably, a 加 The calculation formula is ;in, ; in, v max Let t1 be the vertical velocity of the magnetic rail braking electromagnet 1 at time t1+ΔT1.

[0034] Furthermore, the expression for the electromagnetic force from time t1+ΔT1 to time t1+ΔT1+ΔT2 is: ; The expression for the time interval from t1+△T1 to t1+△T1+△T2 is: ; in: F tv The electromagnetic force generated by the magnetic rail braking electromagnet 1 at time tv; δ tvThe gap between the brake element 3 and the track 6 at time tv; tv represents time tv, and the value range of tv is t1+△T1<tv≤t1+△T1+△T2; M Let the mass of the magnetic rail braking electromagnet 1 be ; a 减 The vertical acceleration of the magnetic rail braking electromagnet from time t1+△T1 to time t1+△T1+△T2; g It is the acceleration due to gravity; K Stiffness of the reset spring 2; x 0 represents the initial deformation of the reset spring 2; δ 0 represents the initial gap between the braking element 3 and the track 6; Preferably, a 减 The calculation formula is ;in, ; in, v max Let t1 be the vertical velocity of the magnetic rail braking electromagnet 1 at time t1+ΔT1.

[0035] Furthermore, the braking element 3 is a brake pad.

[0036] According to the same inventive concept, the present invention also provides a magnetic track braking control system, including a computer device or processor; the computer device or processor is configured or programmed to perform the steps of the magnetic track braking control method described above.

[0037] Based on the same inventive concept, the present invention also provides a rail transit vehicle, including the aforementioned magnetic track braking control system.

[0038] The embodiments of the present invention will be further described in detail below.

[0039] To improve the control accuracy of the electromagnet current in the magnetic track braking system and reduce the instantaneous velocity of the electromagnet upon contact with the track, thereby mitigating the impact of the electromagnet on the vehicle and track, this invention employs a magnetic track braking controller in the magnetic track braking system to achieve precise control of the electromagnet current.

[0040] The present invention provides a magnetic track braking control system and current control strategy, which solves the following problems: (1) Reduce the instantaneous speed of the magnetic rail braking electromagnet when it contacts the rail; (2) Reduce the impact of the magnetic rail braking process on the vehicle and the track; that is, to a certain extent, it reduces the vertical impact and deceleration impact on the vehicle when the magnetic rail braking electromagnet contacts the track. (3) To achieve precise control of the current of the magnetic rail braking electromagnet.

[0041] The distance between the magnetic rail braking electromagnet and the track Given, T1 and T2 is known and can be determined in advance; It can be obtained ; Thus obtain , ; To ensure uniform motion during the acceleration phase, the electromagnetic force required during the acceleration phase... ; In the formula, the spring force Real-time deformation of the spring ; That is, the electromagnetic force required during the acceleration phase. ; Real-time gap value ; The current value to be applied during the acceleration phase can be obtained by looking up a table and interpolating.

[0042] To ensure uniform motion during the deceleration phase, the required electromagnetic force during the deceleration phase is... ; In the formula, the spring force ; Real-time deformation of the spring ; Similarly, the current value to be applied during the deceleration phase can ultimately be obtained by looking up a table and interpolating.

[0043] Considering that during the downward movement of the magnetic rail braking electromagnet, its acceleration can be precisely controlled in real time by the current, but the maximum deceleration is only determined by... F N ( F N The force generated by the return spring determines the deformation. When the deformation of the return spring is minimal, only the initial deformation exists. x 0.

[0044] During current control, while ensuring the response speed of the magnetic rail braking system (the time it takes for the system to generate the corresponding braking force after the command is issued), the current value and the current application time can be optimized and adjusted to a certain extent to avoid generating large vertical impacts and impacts on vehicle deceleration.

[0045] Since the magnetic track braking electromagnet cannot provide feedback on position, velocity, and acceleration, a design is needed to accurately control its velocity to approach zero upon contact with the track. Figure 6 The speed-time curve and gap-time curve of the magnetic rail braking electromagnet are shown.

[0046] The diagram assumes that the downward motion of the magnetic rail braking electromagnet consists only of uniform acceleration and uniform deceleration.

[0047] Based on actual needs, and according to design requirements and actual needs, it is determined that at time t1+△T1+△T2, the electromagnet contacts the track to form a positive pressure, and begins to generate braking friction. When the return spring 2 is in its initial deformation x At time 0, the gap between the magnetic rail braking electromagnet 1 and the track 6 is the initial gap value. δ 0; T is the time required from receiving the magnetic rail braking command to the magnetic rail braking electromagnet contacting the rail, and is a preset value; F The electromagnetic force generated by the magnetic rail braking electromagnet; M The mass of the magnetic rail braking electromagnet; g It is the acceleration due to gravity; a The vertical acceleration of the magnetic rail braking electromagnet; t 1 represents the moment when the electromagnet begins to move downwards. t vmax The moment when the magnetic rail braking electromagnet reaches its maximum speed during downward movement (i.e., t1+ΔT1). t 2 represents the moment when the electromagnet comes into contact with the track; K For the stiffness of the reset spring; Δ x To reset the spring deformation, x 0 represents the initial shape variable. v max This represents the maximum speed of the magnetic rail braking electromagnet during its downward movement. δ This refers to the gap value of the magnetic rail braking electromagnet; t 1 represents the moment when the electromagnet begins to move downwards. t 2 represents the moment when the electromagnet comes into contact with the track; δ This is the gap value of the magnetic rail braking electromagnet.

[0048] in, t 1~ t vmax The electromagnet's motion is uniformly accelerated. t vmax ~ t 2. The electromagnet's motion is a uniformly decelerated motion. t vmax At any given moment, the speed of the electromagnet is measured using... v max express.

[0049] To minimize the vertical impact and vehicle deceleration caused by the contact between the magnetic track braking electromagnet and the track, the current control scheme within the magnetic track braking electromagnet is implemented for real-time and precise control. This can be achieved by combining the experimental results of the magnetic track braking electromagnet's characteristics with... Figure 7 electromagnetic force F-current I -gap δ From the relationship curve, the current required for the electromagnet to accelerate is derived, and thus the current of the magnetic rail braking electromagnet is obtained. I With time t The relationship curve. Figure 7 To establish a simulation model of the magnetic track braking electromagnet based on the experimental results and relevant parameters, and to analyze the characteristic curves of the current and electromagnetic force of the magnetic track braking electromagnet under different gap values, the current variation law during the movement of the magnetic track braking electromagnet is as follows: (1) t 1 moment~ t vmax Within a time (i.e.) t 1 moment~ t At time 1+ΔT1, the output current value of the magnetic track brake controller I = f ( δ , F The electromagnet is braked by the magnetic track, resulting in uniform acceleration during this phase, and the electromagnet rapidly approaches the track at this time. (2) t vmax Moment~ t Within 2 time periods (i.e.) t 1+△T1 time~ t At time 1+△T1+△T2, the output current value of the magnetic track brake controller I = f ( δ , F The magnetic rail brake electromagnet causes uniform deceleration during this phase, and t At time 2, the electromagnet contacts the track at zero speed; (3) t At time 2, upon receiving the brake release command, the magnetic rail brake controller outputs the maximum current value to the magnetic rail brake electromagnet, and the vehicle is in a parking state. Figure 8 As shown; (4) Upon receiving the brake release command, the magnetic track brake controller outputs OA to the magnetic track brake electromagnet, at which point the brake is released, as shown below. Figure 8 As shown.

[0050] This invention provides a magnetic track braking control system, comprising: a power supply, a microcomputer control unit, a magnetic track braking controller, and a magnetic track braking electromagnet.

[0051] In this embodiment, Figure 1The diagram shows a block diagram of a magnetic track braking system. The inputs to the magnetic track braking system are the power supply voltage, braking application and release commands, the levitation system's levitation and descent status, and network communication information. The output is a controllable current to the magnetic track braking electromagnet, which generates an electromagnetic attraction with the track, ultimately achieving control of the braking force. Figure 2 This is a design diagram for a magnetic track braking controller, which mainly consists of a control circuit board, a chopper, and connectors. Figure 3 To control the circuit board topology, it mainly consists of the circuit board's power supply circuit, analog signal processing circuit, microprocessor, digital signal processing circuit, communication circuit, and circuit board connectors. Figure 4 This is a chopper topology diagram. Its main functions are: to receive the PWM control signal output from the control circuit board, condition it into a control signal suitable for the gate of the MOSFET, control the MOSFET's on and off states, control the voltage applied to the electromagnet coil, and ultimately control the current output to the electromagnet.

[0052] The magnetic track brake controller outputs controllable current to two braking electromagnets and collects the feedback current values ​​of the two electromagnets in real time. The magnetic track brake controller can receive externally transmitted ID code signals, brake application / release hard-wire signals, and suspension / landing status hard-wire signals of the suspension system. At the same time, it feeds back the application / release status of the magnetic track brake system to the vehicle via hard wires. The magnetic track brake controller has the functions of uploading the status of the magnetic track brake system, self-diagnostic function of the system status, and communication with the vehicle network.

[0053] The magnetic track brake controller includes a control circuit board, a chopper, and three connectors.

[0054] The control circuit board includes a power supply circuit, an analog signal processing circuit, a microprocessor, a digital signal processing circuit, a communication circuit, and circuit board connectors. The power supply circuit converts the input power (110VDC) of the magnetic track braking system into the voltage level (5V, 12V) required by the control circuit board. The analog signal processing circuit collects the current of electromagnet 1 and electromagnet 2 in real time, filters and conditions the collected current signals, and converts them into digital signals that can be recognized by the microprocessor through an analog-to-digital converter (ADC). The microprocessor executes algorithm calculations and logic control processes based on the received current signal values, control command status, suspension system status, and other signals, and outputs a current control signal (PWM signal) to the digital processing circuit, which outputs it to the chopper after circuit conditioning. The digital signal processing circuit receives the vehicle's brake application / release hardline control commands, suspension system levitation / landing hardline signals, controller ID codes, etc., and sends magnetic track braking system status feedback. The circuit board microprocessor performs self-diagnosis of the magnetic track braking system by receiving digital signals, analog signals, and network information, and sends the self-diagnosis results to the vehicle network through the communication circuit (CAN bus).

[0055] The control chopper includes MOSFETs, drive circuits, and current-isolated sampling circuits.

[0056] The MOSFET is controlled by a PWM signal to achieve high-speed turn-on and turn-off of the drain and source terminals. The drive circuit isolates and boosts the PWM control signal output from the microcomputer control unit, boosting the 3.3V control signal level to 10~15V, which is used as a pulse signal to control the gate input of the MOSFET. The current isolation sampling circuit is a reserved circuit to sample the current, which is convenient for subsequent research on the current control algorithm.

[0057] The three connectors are a power supply and hard-wired signal connector, an output current connector, and a communication connector.

[0058] The power supply and hard-wired signal connectors are used for 110V power supply, levitation system status (hard-wired signal), controller ID encoding signal, hard-wired control command and hard-wired feedback command of the magnetic rail braking system, etc.; the output current connector is used for the interface of the controller output current to the electromagnet; the communication connector is used for the controller's communication interface with external devices.

[0059] The electromagnetic force of a magnetic rail braking electromagnet can be expressed as: F = h ( t , a That is, the electromagnet in t 1~ t The motion process within a time period, electromagnetic force F The above formula should be satisfied. Clearly, the electromagnetic force of an electromagnet is mainly determined by the current flowing through it and the gap; therefore, the electromagnet... t 1~ t The current corresponding to the motion process within the 2 time periods I satisfy: I = f ( δ , F ).

[0060] Electric current can be obtained by experimenting with electromagnets to obtain electromagnetic force. F -gap δ -current I The relative relationship among the three, such as Figure 7 (a) Figure 7 As shown in (b). Based on the test results, the gap was adjusted. δ The experimental data of electromagnetic force F and current I were fitted to obtain... I = f ( δ , F ).

[0061] The apparatus and methods for measuring electromagnetic force and gap in this field are common and can be understood by those skilled in the art.

[0062] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0063] The embodiments of the present invention have been described in detail above, but the content described is only a preferred embodiment of the present invention and should not be considered as limiting the scope of the present invention. All equivalent changes and modifications made within the scope of the present invention should still fall within the scope of the present invention. After reading this invention, those skilled in the art will understand that various equivalent modifications to the present invention fall within the scope defined by the appended claims. Unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

Claims

1. A magnetic track braking control method, characterized in that, include: Step A: From time t1 to time t1+ΔT1, control the current of the magnetic rail braking electromagnet (1) so that the magnetic rail braking electromagnet (1) moves toward the track (6) with uniform acceleration; Step B: From time t1+△T1 to time t1+△T1+△T2, control the current of the magnetic rail braking electromagnet (1) so that the magnetic rail braking electromagnet (1) moves toward the track (6) with uniform deceleration, and so that the speed of the magnetic rail braking electromagnet (1) is 0 at time t1+△T1+△T2. Wherein: △T1+△T2 is the time required from receiving the magnetic track braking command to the braking component (3) contacting the track, and is a preset value; △T1 is a predetermined first time interval, and △T2 is a predetermined second time interval.

2. The magnetic track braking control method according to claim 1, characterized in that, Also includes: Starting from time t1+△T1+△T2, the current of the control rail braking electromagnet (1) is not less than the first preset current threshold I. th_1 Until a brake release command is received; When a brake release command is received, the current of the control magnetic rail brake electromagnet (1) is 0A; Among them, I th_1 The range of values ​​is [I max ×p1, I max The first proportionality coefficient p1 ranges from [80%, 100%). max The maximum current value is set for the magnetic rail braking electromagnet (1).

3. The magnetic track braking control method according to claim 1, characterized in that, The rail vehicle body is connected to the bottom end of the return spring (2), the top end of the return spring (2) is connected to the connecting rod (9), the connecting rod (9) extends downward to below the bottom end of the return spring (2), thereby connecting to the magnetic rail braking electromagnet (1), and the bottom end of the magnetic rail braking electromagnet (1) is connected to a braking element (3) for contacting the rail (6).

4. The magnetic track braking control method according to claim 3, characterized in that, Based on the expression of the electromagnetic force from time t1 to time t1+△T1, the expression of the gap from time t1 to time t1+△T1, and based on the predetermined relationship between the gap, electromagnetic force, and current of the magnetic rail braking electromagnet (1), the required current of the magnetic rail braking electromagnet (1) from time t1 to time t1+△T1 is obtained. Based on the expression of the electromagnetic force from time t1+△T1 to time t1+△T1+△T2, the expression of the gap from time t1+△T1 to time t1+△T1+△T2, and based on the predetermined relationship between the gap, electromagnetic force, and current of the magnetic rail braking electromagnet (1), the required current of the magnetic rail braking electromagnet (1) from time t1+△T1 to time t1+△T1+△T2 is obtained. Among them, the gap is the gap between the brake (3) and the track (6), and the electromagnetic force is the electromagnetic force generated by the magnetic track brake electromagnet (1); Preferably, △T1 > △T2.

5. The magnetic track braking control method according to claim 4, characterized in that, The relationship between the gap, electromagnetic force, and current of the rail brake electromagnet (1) is a surface fitted in the oxyz coordinate system, where the ox axis represents the current of the rail brake electromagnet (1), the oy axis represents the electromagnetic force, and the oz axis represents the gap; or The relationship between the gap, electromagnetic force, and magnetic rail braking electromagnet (1) current is presented in tabular form.

6. The magnetic track braking control method according to claim 4, characterized in that, The expression for the electromagnetic force from time t1 to time t1+ΔT1 is: ； The method for calculating the expression for the time interval from time t1 to time t1+ΔT1 is as follows: ； in: F tu Let tu be the electromagnetic force generated by the magnetic rail braking electromagnet (1); δ tu Let tu be the gap between the brake (3) and the track (6) at time tu; the range of tu is t1≤tu≤t1+△T1; M Mass of the magnetic rail braking electromagnet (1); a 加 Let be the vertical acceleration of the magnetic rail braking electromagnet (1) from time t1 to time t1+ΔT1; g It is the acceleration due to gravity; K Stiffness of the reset spring (2); x 0 represents the initial deformation of the reset spring (2); δ 0 represents the initial gap between the brake element (3) and the track (6); Preferably, a 加 The calculation formula is ;in, ; in, v max Let t1 be the vertical velocity of the magnetic rail braking electromagnet (1) at time t1+△T1.

7. The magnetic track braking control method according to claim 4, characterized in that, The expression for the electromagnetic force from time t1+ΔT1 to time t1+ΔT1+ΔT2 is: ； The expression for the time interval from t1+△T1 to t1+△T1+△T2 is: ； in: F tv The electromagnetic force generated by the magnetic rail braking electromagnet (1) at time tv; δ tv The gap between the brake (3) and the track (6) at time tv; the range of tv is t1+△T1<tv≤t1+△T1+△T2; M Mass of the magnetic rail braking electromagnet (1); a 减 The vertical acceleration of the magnetic rail braking electromagnet from time t1+△T1 to time t1+△T1+△T2; g It is the acceleration due to gravity; K Stiffness of the reset spring (2); x 0 represents the initial deformation of the reset spring (2); δ 0 represents the initial gap between the brake element (3) and the track (6); Preferably, a 减 The calculation formula is ;in, ; in, v max Let t1 be the vertical velocity of the magnetic rail braking electromagnet (1) at time t1+△T1.

8. The magnetic track braking control method according to claim 4, characterized in that, The braking component (3) is a brake pad.

9. A magnetic track braking control system, characterized in that, Includes a computer device or processor; said computer device or processor is configured or programmed to perform the steps of the magnetic track braking control method according to any one of claims 1-8.

10. A rail transit vehicle, characterized in that, Includes the magnetic track braking control system as described in claim 9.

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