Multi-unit rubber-tyred electric train ramp anti-slipping control method and system

Abstract

The application discloses a multi-formation rubber-tyred electric train slope anti-sliding control method and system, which predicts the slope starting torque through the motor feedback torque and the instantaneous acceleration calculation value, and the train does not need a slope sensor, thereby reducing the implementation cost of the anti-sliding slope function; the distributed drive train reduces the motor stall time through the team formation and torque polling control of the control motor, optimizes the motor temperature rise, and improves the service life of the motor. The real-time monitoring of the torque in the anti-sliding slope process determines the minimum starting torque and determines the exit time of the anti-sliding slope. The starting anti-sliding strategy and the out-of-control control strategy of the motor improve the safety of the system.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of rail transit, in particular to a slope anti-slip control method and system for a multi-formation rubber-tyred electric train. BACKGROUND

[0002] Many vehicle enterprises in the field of new energy commercial vehicles and passenger vehicles have their own mature anti-slip slope control functions, which can ensure that the vehicle realizes a short anti-slip slope function on any road surface. The realization of these functions is achieved by increasing related sensors to detect the slope, or by combining the motor torque and the mechanical braking torque, or by only using the motor torque control. The motor is usually in a locked state when the anti-slip slope function is realized by using the motor torque, and the temperature rise is large, so the anti-slip slope time cannot be too long. The existing anti-slip slope related solutions are all around single axle driving, and there is no related research on the anti-slip slope function of multi-formation distributed wheel edge driving trains.

[0003] The SRT vehicle belongs to a road train, and compared with rail transit, it has the characteristics of large slope, short station spacing, complex wet road surface, frequent starting, etc. When entering the station and stopping or stopping on the slope, the driver will usually step on the foot brake to prevent the vehicle from slipping on the slope. This operation method consumes a lot of energy and physical strength of the driver; if the driver locks the vehicle by pulling the hand brake, the series of operation processes are relatively complex, and must be completed in a short time, otherwise the vehicle will slip. In the case of air brake participation, the charging and discharging process not only has noise, but also consumes air and energy, and the customer experience is poor; if the driver does not operate properly, the train will slip a long distance, which is easy to collide with the rear vehicle and cause safety accidents. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a slope anti-slip control method and system for a multi-formation rubber-tyred electric train, which does not require a slope sensor and reduces the implementation cost of the anti-slip slope function.

[0005] To solve the above technical problems, the technical scheme adopted by the present application is as follows: a slope anti-slip control method for a multi-formation rubber-tyred electric train, comprising the following steps:

[0006] S1, when the accelerator, brake and hand brake are not operated, and the train speed is 0, an initial torque is given; the initial torque is represented as:

[0007] F PS =AVE(∑F P (t)-max|F P (t)|-min|F P (t)|);

[0008] Wherein, F P (t) = m T · a(t) - F Z (t) - F T (t), F Z (t) = f · m T · g + C D · A · V(t) 2 / 21.15; a(t) is the acceleration of the train at time t, m T is the total weight of the train, F T (t) is the total electric control torque of the train at time t, F j1 (t) and F j2 (t) are the first motor feedback torque and the second motor feedback torque of the jth axle of the train at time t respectively, n is the number of train nodes, V(t) is the running speed of the train at time t, g is the acceleration of gravity, AVE() represents the average value, C D is the drag coefficient, and A is the wind area of the vehicle.

[0009] S2, detecting whether to slide backward, if yes, then increasing the initial torque by a proportion P% to obtain the motor feedback torque of the corrected motor controller; wherein, Δn is the motor speed difference feedback by the motor controller per unit time;

[0010] S3, judging whether an anti-slip slope exit operation request is received, if yes, then when the traction force is greater than the sliding force, entering a normal traction mode and starting the train.

[0011] The application can predict the slope starting torque through the motor feedback torque and the instantaneous acceleration calculation value, and the train does not need a slope sensor, thereby reducing the implementation cost of the anti-slip slope function.

[0012] When starting the train, the minimum value F Start (t) of the motor feedback torque at time t is calculated by the formula:

[0013]

[0014] The method of the application further comprises:

[0015] S4, judging whether the motor feedback torque reaches balance, if yes, then when the anti-slip slope function exceeds the set duration, distributing the motor feedback torque in proportion.

[0016] The application drives the train in a distributed manner, reduces the locked-rotor time of the motor through the teaming and torque polling control of the control motor, optimizes the motor temperature rise, and improves the service life of the motor.

[0017] In the application, the axles are divided into groups in a two-in-a-group manner, and the motor feedback torque is evenly distributed to each group; the calculation formula of the torque in a group is:

[0018]

[0019] F j (t) and F j+1 (t) represent a group torque, C const represents the total torque, F Max is the maximum torque.

[0020] When the temperature of the axle with a larger torque in a group of axles rises by more than a set number of degrees in a unit of time, or the axle with a larger torque maintains a larger torque for a duration of time that exceeds a set value, the torque of the axle with a larger torque is reduced.

[0021] Before the calculation of the initial torque, the operation including the following steps is performed:

[0022] 1) Determine whether the train is in a braking working condition, if yes, determine whether the train is in a deceleration process when the train speed is lower than a set value, if yes, when the train does not have friction braking, compare the current value of the motor feedback torque with the maximum and minimum values of the motor feedback torque in real time, if the current value of the motor feedback torque is greater than the maximum value of the motor feedback torque, set the current value of the motor feedback torque as the maximum value of the motor feedback torque, if the current value of the motor feedback torque is less than the minimum value of the motor feedback torque, set the current value of the motor feedback torque as the minimum value of the motor feedback torque.

[0023] 2) Determine whether the train speed is lower than a set value, if yes, calculate the initial torque.

[0024] As an inventive concept, the application further provides a multi-formation rubber-tyre electric train, comprising a plurality of cars, wherein the axles of the first car and the last car are non-driving axles, and the remaining axles are driving axles; the torque of the driving axles is determined according to the steps of the above method.

[0025] As an inventive concept, the application further provides a slope anti-slip control system for a multi-formation rubber-tyre electric train, comprising a memory and a processor; the memory stores a computer program, and the computer program is executed by the processor to implement the steps of the above method.

[0026] Compared with the prior art, the application has the beneficial effects that: the application can predict the slope starting torque through the motor feedback torque and the instantaneous acceleration calculation value, the train does not need a slope sensor, and the implementation cost of the anti-slip slope function is reduced; the distributed drive train reduces the locked-rotor time of the motor, optimizes the motor temperature rise, and improves the service life of the motor through the team control and torque polling control of the control motor; the real-time monitoring of the torque in the anti-slip process determines the minimum starting torque and the anti-slip exit timing; and the starting anti-slip strategy and the out-of-control control strategy of the motor improve the safety of the system. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The distributed drive train topology for the embodiment of the application;

[0028] Figure 2 The initial torque calculation method of the anti-slip slope torque (motor feedback torque) for the embodiment of the application;

[0029] Figure 3 The anti-slip control process for the embodiment of the application;

[0030] Figure 4 The torque switching control process for the embodiment of the application;

[0031] Figure 5 The in-group torque switching method principle for the embodiment of the application;

[0032] Figure 6 The train rear slip out-of-control determination process for the embodiment of the application. DETAILED DESCRIPTION

[0033] To make the purposes, technical solutions and advantages of the embodiments of the application clearer, the technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are some of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0034] In the embodiment of the present application, all the shafts are set as driving shafts except the first shaft and the last shaft which are non-driving shafts. The motor controller MCU on all the shafts is connected with the train traction controller DCU through CAN bus, and the DCU realizes the coordinated management control of the traction torque of each shaft. The vehicle controller VCU is connected with the DCU through CAN bus, and the VCU realizes the control of the traction mode and the total torque of the train by collecting the state of the whole vehicle. The ECAS is the suspension controller of the vehicle, mainly collects the air pressure of the air suspension of the axle, adjusts the floor height, and multiple ECASs are networked with the VCU through CAN bus. The load of the train is calculated by the pressure change in the air spring, and the load is usually locked after the first traction instruction is given when the doors are closed, which is used for the calculation of the train traction and braking force.

[0035] The calculation strategy of the anti-slope sliding torque initial torque is proposed by analyzing the running conditions of the train. The calculation of the anti-slope sliding torque initial torque adopts the following calculation method.

[0036] The total mass of the train is m oi The empty car mass of the ith section is k, the air spring mass conversion coefficient is Δp i The air spring pressure change amount relative to the empty air spring pressure value is n, and the number of sections of the train is n.

[0037] The total electric control torque of the train at time t is F j1 (t) and F j2 (t) are respectively the feedback torques of the first and second motors of the jth shaft, and their sum is defined as F j (t).

[0038] F Z (t) = f · m T · g + C D · A · V(t) 2 / 21.15 is the basic resistance formula of the train at time t, wherein V(t) is the running speed of the train at time t, m T is the total weight of the train, and the others are parameters, which are the coefficients measured according to the basic resistance test.

[0039] The acceleration of the train at time t is a(t).

[0040] When the motor feedback torque of the train is the braking torque, the vehicle speed is less than the set value (such as less than 10 km / h), and the calculated acceleration is negative, the slope force calculation of the train stopping process is triggered.

[0041] F P (t) = m T · a(t) - F Z (t) - FT (t) is the ramp down force at time t for train t.

[0042] F PS =AVE(∑F P (t)-max|F P (t)|-min|F P (t)|) is the initial anti-rolling ramp force moment, which is calculated by removing the maximum and minimum values and averaging the ramp resistance.

[0043] The first anti-rolling ramp moment is calculated by the motor feedback moment. When the vehicle still rolls backward after the moment is given, the motor feedback moment is increased by a certain percentage P%.

[0044] The value of P% is determined by the motor speed difference Δn in a unit time (e.g., the last 10 communication periods) after the previous motor feedback moment is given. The given principle is as follows:

[0045]

[0046] If the feedback direction is backward, the motor feedback moment is increased by P%. If the feedback direction is forward, the motor feedback moment is decreased by P%. The given principle of P% is calibrated by test for different vehicle models.

[0047] The anti-rolling ramp control process is as follows Figure 3 .

[0048] The anti-rolling ramp condition should meet the following conditions: when the accelerator pedal and brake pedal are not operated, the hand brake is not applied, the train speed is 0, the software RS triggers the anti-rolling ramp mode, and the initial moment calculated above is given.

[0049] The VCU monitors the motor speed, rotation direction, and moment in real time through communication with the DCU. When it is detected that there is still a threshold movement in a unit time, the moment is adjusted according to the P% correction moment parameter.

[0050] The current calibrated moment value is recorded and compared with the previous moment value. When the feedback speed v(t) is less than or equal to 0, it indicates backward rolling, and when it is greater than 0, it indicates forward rolling. When the feedback is backward rolling, the maximum value is cached, and when the feedback is forward rolling, the minimum value is recorded. This detection is performed throughout the anti-rolling ramp process until the anti-rolling ramp exits. The recorded moment F Start (t) is used as the minimum moment for subsequent start.

[0051]

[0052] When the motor feedback torque searches for the best torque, or the anti-slip function reaches the set value (such as 10 seconds), in order to ensure that the motor generates the least heat, the efficiency is the highest, and the aging of the motor is reduced, the motor torque of the distributed drive shaft is polled and controlled.

[0053] The motor feedback torque is distributed in time and is distributed to each pair of shafts in percentage. For example, a three-module train, the first shaft and the last shaft are non-driven shafts, so there is no motor torque, and the available motor torque shafts are shaft 2, shaft 3, shaft 4, and shaft 5. Among them, shaft 2 and shaft 3 form a group and bear 50% of the total anti-slip torque, and shaft 5 and shaft 4 form a group and bear the other 50% of the total anti-slip torque. Similarly, for other four-formation trains, they can be divided into three groups, and each group bears 34% of the size, and the same applies to multi-formation trains. j (t) and F j+1 (t) represents a group of torques, and the torque in the group satisfies the following functional relationship.

[0054]

[0055] The distribution between the motors on the two shafts in the same group is distributed according to the motor characteristics to ensure that the motor stall torque does not exceed the maximum torque F Max . At the same time, the torque of the minimum torque shaft cannot be zero in any working condition. The sum of the torques of the two shafts in the same group is the total torque C const

[0056] The prerequisite for alternating polling of torque size is that when the temperature of the shaft with large torque rises significantly (such as an increase of more than 5 degrees per unit time), or the duration of the shaft with large torque exceeds the set value (such as 5s), the torque will be reduced by a certain percentage, and the torque of the other shaft paired with it will be increased by the same percentage. In the process of torque switching, the total torque is kept unchanged. As shown in Figure 5 . In this way, the motor will not be continuously large torque, which will cause the motor to overheat.

[0057] When the paired motor group has a motor failure and cannot generate torque, the motor of the non-fault shaft generates torque according to the predefined torque. The excess torque is evenly distributed to other groups. When more than two shafts have motor failures, the system will prompt that it cannot enter the anti-slip mode.

[0058] In the rear slip detection process, due to special reasons, the anti-slip fails, the train loses control, and the vehicle always slips backward. In order to avoid such situations and ensure safety, the control system provides real-time detection, and once the rear distance exceeds the specified value (such as 1 meter), the control system will automatically apply the parking brake to ensure that the train does not slip backward.

[0059] The anti-runaway mode exit and train start control strategy is very important. When the driver presses the accelerator or the driving assistance system requests to start the train, the anti-runaway mode request does not immediately exit. Instead, it exits only when the total torque driven by the request calculated by the VCU is greater than the aforementioned F. Start (t), and in fact the total torque F fed back by the motor T (t) is greater than F Start When (t), the anti-slippage mode is deactivated, and the train enters normal traction mode, thus avoiding slippage during startup.

[0060] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0061] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A method for preventing a multi-formation rubber-tyred electric train from sliding on a ramp, characterized in that, The method comprises the following steps: S1, when the accelerator, brake and handbrake are not operated, and the train speed is 0, an initial torque is given; the initial torque is represented as: F PS =AVE(∑F P (t)-max|F P (t)|-min|F P (t)|) wherein F P (t) = m T · a(t) - F Z (t) - F T (t), F Z (t) = f · m T · g + C D · A · V(t) 2 / 21.15; a(t) is the acceleration of the train at time t, m T is the total weight of the train, F T (t) is the total electric control torque of the train at time t, F j1 (t) and F j2 (t) are respectively the first motor feedback torque and the second motor feedback torque of the jth axle of the train at time t, n is the number of axles of the train, V(t) is the running speed of the train at time t, g is the acceleration of gravity, AVE() represents the average value, C D is the drag coefficient, and A is the windward area of the vehicle. S2, whether the train is sliding backward is detected, if yes, the initial torque is increased by a proportion P%, and a corrected motor feedback torque of each motor controller is obtained; wherein, Δn is the motor speed difference fed back by the motor controller per unit time; S3, whether an anti-slip function exit operation request is received is judged, if yes, when the traction force is greater than the sliding force, a normal traction mode is entered, and the train is started; The minimum motor feedback torque F at time t when starting the train Start (t) The calculation formula is: S4, whether the motor feedback torque reaches a balance is judged, if yes, when the anti-slip function exceeds a set duration, the motor feedback torque is proportionally distributed; The axles are divided into groups in a two-by-two manner, and the motor feedback torque is evenly distributed to each group; The calculation formula of the torque in a group is: where F j (t) represents a set of torques, C j+1 (t) represents a set of torques, C const represents the total torque, F Max is the maximum torque.

2. The control method according to claim 1, wherein When the temperature of the axle with greater torque in a group rises by more than a set number of degrees in a unit time, or the axle with greater torque maintains a greater torque for a duration exceeding a set value, the torque of the axle with greater torque is reduced.

3. The control method of claim 1, wherein, Before the initial torque is calculated, the following steps are performed: 1) whether the train is in a braking working condition is judged, if yes, when the train speed is lower than a set value, whether the train is in a deceleration process is judged, if yes, when the train does not have friction braking, the size relationship between the current value of the motor feedback torque and the maximum and minimum values of the motor feedback torque is compared in real time, if the current value of the motor feedback torque is greater than the maximum value of the motor feedback torque, the current value of the motor feedback torque is set as the maximum value of the motor feedback torque, if the current value of the motor feedback torque is less than the minimum value of the motor feedback torque, the current value of the motor feedback torque is set as the minimum value of the motor feedback torque; 2) whether the train speed is lower than a set value is judged, if yes, the initial torque is calculated.

4. A multiple unit rubber-tyred electric train, characterized by The train comprises multiple cars, wherein the axles of the first car and the last car are non-driving axles, and the remaining axles are driving axles; the torque of the driving axles is determined according to the steps of the method of any one of claims 1-3.

5. A slope anti-slip control system for a multi-unit rubber-tyred electric train, characterized in that, The device comprises a memory and a processor; the memory stores a computer program, and the computer program is executed by the processor to realize the steps of the method of any one of claims 1-3.

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