阅读说明：本技术 一种满足地铁秒级调整的ato巡航速度实时优化方法 (ATO cruising speed real-time optimization method meeting subway second-level adjustment ) 是由 王义惠 朱松巍 魏国栋 孟令云 苗建瑞 周达天 于 2021-08-10 设计创作，主要内容包括：本发明提供了一种满足地铁秒级调整的ATO巡航速度实时优化方法。该方法包括：根据列车运行线路信息的基础参数,基于列车的当前运行状况通过映射函数计算列车的剩余时间映射；根据线路信息与列车信息的基础参数,基于列车的当前运行状况进行列车运行仿真,计算列车的估计剩余时间；根据所述列车的剩余时间映射与所述估计剩余时间通过二分法计算出列车的巡航速度,根据列车的限速条件输出对应的列车的巡航速度。本发明通过计算剩余时间的映射与估计剩余时间,使用二分法实时地优化ATO巡航速度,可以提高列车的准时性,并用惰行代替不必要的制动,起到节能的效果。(The invention provides a real-time optimization method for the ATO cruising speed meeting subway second-level adjustment. The method comprises the following steps: calculating the remaining time mapping of the train through a mapping function based on the current running state of the train according to the basic parameters of the train running line information; according to the basic parameters of the line information and the train information, carrying out train operation simulation based on the current operation condition of the train, and calculating the estimated remaining time of the train; and calculating the cruising speed of the train by bisection according to the remaining time mapping of the train and the estimated remaining time, and outputting the cruising speed of the corresponding train according to the speed limiting condition of the train. The invention can improve the punctuality of the train by calculating the mapping of the remaining time and estimating the remaining time and optimizing the ATO cruising speed in real time by using the dichotomy, and replace unnecessary braking by using coasting to achieve the effect of energy saving.)

1. A real-time optimization method for the ATO cruising speed meeting subway second-level adjustment is characterized by comprising the following steps:

calculating the remaining time mapping of the train through a mapping function based on the current running state of the train according to the basic parameters of the train running line information;

according to the basic parameters of the line information and the train information, carrying out train operation simulation based on the current operation condition of the train, and calculating the estimated remaining time of the train;

and calculating the cruising speed of the train by bisection according to the remaining time mapping of the train and the estimated remaining time, and outputting the cruising speed of the corresponding train according to the speed limiting condition of the train.

2. The method according to claim 1, wherein the calculating the remaining time map of the train through the mapping function based on the current operation condition of the train according to the basic parameter of the train operation line information comprises:

reading basic parameters of train operation line information, wherein the basic parameters comprise line gradient, speed limit, train traction braking characteristics, current train position, speed and residual operation time information;

the mapping function used to calculate the remaining time map based on the current operating conditions of the train is as follows:

wherein, t_aTarget running time, t_uFor the current elapsed time, A and B are the mapping coefficients, s_lIs the distance, s, between the current train and the destination station_tThe station spacing of the train in the current operation (t)_a-t_u) And determining A and B according to an ATO lower layer PID control strategy for the current residual time division.

3. The method of claim 1, wherein said simulating the train operation based on the current operation condition of the train according to the basic parameters of the line information and the train information to calculate the estimated remaining time of the train comprises:

according to the current train position, the train speed, the train cruising speed, the basic line resistance, the additional line resistance, the train dynamic characteristics and the speed limit information, carrying out train operation simulation based on the maximum principle, and calculating the estimated remaining time;

for the train operation simulation, the train dynamics model is as follows

Wherein v and x are respectively the running speed and position of the train, u_fAnd u_bThe percentage of the traction force and the braking force in the maximum traction force and the maximum braking force is respectively selected from 0 to 1, f (v) and b (v) are respectively the maximum traction force and the maximum braking force of the train, w (v) is the basic resistance in the running process of the train, g (x) is the additional resistance in the running process, and the speed v (v) of the starting point of the train is the speed v (v) of the starting point of the train₀End point velocity v_THave an appointmentThe bundling conditions were as follows

v(x₀)＝v₀

v(x_T)＝v_T

Wherein x₀As the start of train operation, x_TFor the end of train operation, the train speed v during train operation must not exceed the limit speed v (x), i.e. the speed v (x) is limited

v≤V(x)

The performance indexes of the train in the running process are as follows:

wherein L is Lagrange multiplier and is greater than 0, constructing the following Hamiltonian

Where P is the adjoint equation function and M is the complementary relaxation condition for the speed limit, defining the adjoint variable P ═ P/v, and substituting P into the hamiltonian, yields:

to maximize the Hamiltonian，u_fAnd u_bThe values of (A) are as follows:

1. if p > 1, then u_f＝1，u_bThe maximum traction condition is 0;

2. if p is 1, then u_f∈[0，1]，u_bThe working condition is 0, and the partial traction is performed;

3. if 0 < p < 1, then u_f＝0，u_bSetting the working condition as 0 and idling;

4. if p is 0, then u_f＝0，u_b∈[0，1]Partial braking conditions;

5. if p < 0, then u_f＝0，u_bAnd 1, the maximum braking condition is set.

Taking p as a derivative of x yields:

wherein f ', b ', w ' is f (v), b (v), w (v) calculates partial derivatives of v, calculates the traction and braking force of the train based on the maximum value principle, and calculates the estimated remaining time t needed by the train to run to the terminal point through the train running simulation process according to the obtained traction and braking force_es。

4. The method according to claim 3, wherein the calculating the cruising speed of the train by the dichotomy according to the remaining time mapping and the estimated remaining time of the train and outputting the cruising speed of the corresponding train according to the speed limiting condition of the train comprises:

reading the current cruising speed, the station distance, the current position, the current train speed, the current used time, the maximum traction acceleration, the maximum braking acceleration and the initialized estimated residual time t of the train_esWill t_esSet to 0, determine that the current train speed is greater than 0 and does not reach the end? If yes, calculating the position t of the train after 0.2s according to the uniform acceleration motion_es＝t_es+0.2, when the cruising speed at the next moment is greater than the speed limit, the cruising speed at the next moment is setFor limiting the speed, updating the speed of the train after 0.2s based on the maximum principle according to the cruising speed and the maximum acceleration, judging the current train speed to be more than 0 again and not reaching the terminal point until the train reaches the terminal point, and outputting t_es。

5. The method according to claim 3 or 4, wherein the calculating the cruising speed of the train by the dichotomy according to the remaining time mapping and the estimated remaining time of the train and outputting the cruising speed of the corresponding train according to the speed limiting condition of the train comprises:

setting the cruising speed as a preset highest speed, calculating estimated remaining time at the highest speed through train operation simulation, and if the estimated remaining time is greater than the remaining time mapping, setting the cruising speed as the preset highest speed and outputting the cruising speed; if the estimated remaining time is not greater than the remaining time mapping, the cruising speed is not set as the preset highest speed;

setting the cruising speed as a preset lowest speed, carrying out train operation simulation, calculating estimated remaining time at the lowest speed, and if the estimated remaining time is less than the remaining time mapping, setting the cruising speed as the preset lowest speed and outputting the cruising speed; if the estimated remaining time is not less than the remaining time mapping, the cruising speed is not set to be the preset lowest speed;

calculating the average value of the highest speed and the lowest speed, taking the average value as the cruising speed, calculating the estimated remaining time, and if the difference between the estimated remaining time and the remaining time is in a given range, enabling the train to run at the cruising speed to meet the time requirement, and outputting the cruising speed;

if the difference between the estimated remaining time and the remaining time mapping is not in the given range, the cruising speed is modified according to the magnitude relation between the estimated remaining time and the remaining time mapping, if the estimated remaining time is larger than the remaining time mapping, the lowest speed is set as the current cruising speed, the average value of the highest speed and the lowest speed is calculated again, the bisection method is repeated until the difference between the estimated remaining time and the remaining time mapping is in the given range, and the cruising speed is output; and if the estimated remaining time is not greater than the remaining time mapping, setting the highest speed as the current cruising speed, calculating the average value of the highest speed and the lowest speed again, repeating the bisection method until the difference between the estimated remaining time and the remaining time mapping is in a given range, and outputting the cruising speed.

6. The method as claimed in claim 5, wherein the outputting of the cruising speed of the corresponding train according to the speed limit condition of the train comprises:

comparing the cruising speed of the train with the speed limit, and if the cruising speed of the train is greater than the speed limit, setting the cruising speed of the train as the speed limit and outputting the speed limit; and if the cruising speed of the train is not greater than the speed limit, directly outputting the cruising speed.

Technical Field

The invention relates to the technical field of subway Train speed optimization, in particular to a method for optimizing the cruising speed of an ATO (Automatic Train Operation) meeting subway second-level adjustment in real time.

Background

Subways play a very important role in passenger transport in urban traffic. Recently, urban rail transit in China is developed vigorously, and with the improvement of line length and passenger capacity, energy consumed by the urban rail transit is gradually increased, so that pressure is exerted on environment and resources on the one hand, and the operation cost of subway companies is increased on the other hand. The traction energy consumption of the train accounts for a large proportion of the urban rail transit operation energy consumption, and the traction energy consumption of the train is closely related to the automatic driving of the ATO system because the train realizes the automatic driving through the ATO system, so that the traction energy consumption of the train needs to be optimized.

Currently, the ATO system in the prior art mainly uses a PID (proportional, integral and derivative) algorithm to track the cruise speed curve calculated off-line through a speed automatic control module. However, due to the limited control accuracy of the PID algorithm, the train cannot operate according to the cruise speed curve completely and accurately, and the curve calculated off-line cannot be adjusted in real time according to the deviation between the current train operation condition and the cruise speed curve, so that tracking the cruise speed curve calculated off-line may cause the train to repeatedly switch between traction and braking conditions near the stop stage, which may cause unnecessary energy consumption and may have a certain influence on the accuracy of train operation and the comfort of passengers. Therefore, the cruising speed needs to be optimized in real time according to the actual running condition of the train, the punctuality of the train is ensured, the times of unnecessary braking are reduced, the comfort level of passengers is improved, and the energy consumption of train running is reduced.

Disclosure of Invention

The embodiment of the invention provides a real-time optimization method for the ATO cruising speed meeting subway second-level adjustment, so as to meet the requirements of a train on a punctuality and energy conservation.

In order to achieve the purpose, the invention adopts the following technical scheme.

An ATO cruising speed real-time optimization method meeting subway second-level adjustment comprises the following steps:

calculating the remaining time mapping of the train through a mapping function based on the current running state of the train according to the basic parameters of the train running line information;

according to the basic parameters of the line information and the train information, carrying out train operation simulation based on the current operation condition of the train, and calculating the estimated remaining time of the train;

and calculating the cruising speed of the train by bisection according to the remaining time mapping of the train and the estimated remaining time, and outputting the cruising speed of the corresponding train according to the speed limiting condition of the train.

Preferably, the calculating the remaining time map of the train through the mapping function based on the current operation condition of the train according to the basic parameters of the train operation line information includes:

reading basic parameters of train operation line information, wherein the basic parameters comprise line gradient, speed limit, train traction braking characteristics, current train position, speed and residual operation time information;

the mapping function used to calculate the remaining time map based on the current operating conditions of the train is as follows:

wherein, t_aTarget running time, t_uFor the current elapsed time, A and B are the mapping coefficients, s_lIs the distance, s, between the current train and the destination station_tThe station spacing of the train in the current operation (t)_a-t_u) And determining A and B according to an ATO lower layer PID control strategy for the current residual time division.

Preferably, the simulating the train operation based on the current operation condition of the train according to the basic parameters of the line information and the train information to calculate the estimated remaining time of the train includes:

according to the current train position, the train speed, the train cruising speed, the basic line resistance, the additional line resistance, the train dynamic characteristics and the speed limit information, carrying out train operation simulation based on the maximum principle, and calculating the estimated remaining time;

for the train operation simulation, the train dynamics model is as follows

Wherein v and x are respectively the running speed and position of the train, u_fAnd u_bThe percentage of the traction force and the braking force in the maximum traction force and the maximum braking force is respectively selected from 0 to 1, f (v) and b (v) are respectively the maximum traction force and the maximum braking force of the train, w (v) is the basic resistance in the running process of the train, g (x) is the additional resistance in the running process, and the speed v (v) of the starting point of the train is the speed v (v) of the starting point of the train₀End point velocity v_TWith the constraint conditions as follows

v(x₀)＝v₀

v(x_T)＝v_T

Wherein x₀As the start of train operation, x_TFor the end of train operation, the train speed v during train operation must not exceed the limit speed v (x), i.e. the speed v (x) is limited

v≤V(x)

The performance indexes of the train in the running process are as follows:

wherein L is Lagrange multiplier and is greater than 0, constructing the following Hamiltonian

Where P is the adjoint equation function and M is the complementary relaxation condition for the speed limit, defining the adjoint variable P ═ P/v, and substituting P into the hamiltonian, yields:

to maximize the Hamiltonian, u_fAnd u_bThe values of (A) are as follows:

1. if p > 1, then u_f＝1，u_bThe maximum traction condition is 0;

2. if p is 1, then u_f∈[0，1]，u_bThe working condition is 0, and the partial traction is performed;

3. if 0 < p < 1, then u_f＝0，u_bSetting the working condition as 0 and idling;

4. if p is 0, then u_f＝0，u_b∈[0，1]Partial braking conditions;

5. if p < 0, then u_f＝0，u_bAnd 1, the maximum braking condition is set.

Taking p as a derivative of x yields:

wherein f ', b ', w ' are f (v), b (v), w (v) are partial derivatives of vCalculating the traction force and the braking force of the train based on the maximum principle, and calculating the estimated remaining time t required by the train to run to the terminal through a train running simulation process according to the obtained traction force and the braking force_es。

Preferably, the calculating the cruising speed of the train by the bisection method according to the remaining time map of the train and the estimated remaining time and outputting the cruising speed of the corresponding train according to the speed limit condition of the train includes:

reading the current cruising speed, the station distance, the current position, the current train speed, the current used time, the maximum traction acceleration, the maximum braking acceleration and the initialized estimated residual time t of the train_esWill t_esSet to 0, determine that the current train speed is greater than 0 and does not reach the end? If yes, calculating the position t of the train after 0.2s according to the uniform acceleration motion_es＝t_es+0.2, when the cruising speed at the next moment is higher than the speed limit, setting the cruising speed at the next moment as the speed limit, updating the speed of the train after 0.2s according to the cruising speed and the maximum acceleration based on the maximum principle, judging the speed of the train at the current moment is higher than 0 and does not reach the terminal point again until the train reaches the terminal point, and outputting t_es。

Preferably, the calculating the cruising speed of the train by the bisection method according to the remaining time map of the train and the estimated remaining time and outputting the cruising speed of the corresponding train according to the speed limit condition of the train includes:

setting the cruising speed as a preset highest speed, calculating estimated remaining time at the highest speed through train operation simulation, and if the estimated remaining time is greater than the remaining time mapping, setting the cruising speed as the preset highest speed and outputting the cruising speed; if the estimated remaining time is not greater than the remaining time mapping, the cruising speed is not set as the preset highest speed;

setting the cruising speed as a preset lowest speed, carrying out train operation simulation, calculating estimated remaining time at the lowest speed, and if the estimated remaining time is less than the remaining time mapping, setting the cruising speed as the preset lowest speed and outputting the cruising speed; if the estimated remaining time is not less than the remaining time mapping, the cruising speed is not set to be the preset lowest speed;

calculating the average value of the highest speed and the lowest speed, taking the average value as the cruising speed, calculating the estimated remaining time, and if the difference between the estimated remaining time and the remaining time is in a given range, enabling the train to run at the cruising speed to meet the time requirement, and outputting the cruising speed;

if the difference between the estimated remaining time and the remaining time mapping is not in the given range, the cruising speed is modified according to the magnitude relation between the estimated remaining time and the remaining time mapping, if the estimated remaining time is larger than the remaining time mapping, the lowest speed is set as the current cruising speed, the average value of the highest speed and the lowest speed is calculated again, the bisection method is repeated until the difference between the estimated remaining time and the remaining time mapping is in the given range, and the cruising speed is output; and if the estimated remaining time is not greater than the remaining time mapping, setting the highest speed as the current cruising speed, calculating the average value of the highest speed and the lowest speed again, repeating the bisection method until the difference between the estimated remaining time and the remaining time mapping is in a given range, and outputting the cruising speed.

Preferably, the outputting the cruising speed of the corresponding train according to the speed limit condition of the train includes:

comparing the cruising speed of the train with the speed limit, and if the cruising speed of the train is greater than the speed limit, setting the cruising speed of the train as the speed limit and outputting the speed limit; and if the cruising speed of the train is not greater than the speed limit, directly outputting the cruising speed.

According to the technical scheme provided by the embodiment of the invention, the ATO cruising speed is optimized in real time by calculating the mapping of the remaining time and estimating the remaining time and using the dichotomy, so that the punctuality of the train can be improved, unnecessary braking is replaced by coasting, and the energy-saving effect is achieved.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a processing flow chart of a method for optimizing ATO cruise speed in real time, which satisfies subway second-level adjustment and is provided by an embodiment of the present invention.

Fig. 2 is a schematic diagram of calculating a remaining time map based on current operating conditions according to basic parameters of line information according to an embodiment of the present invention.

Fig. 3 is a flowchart for calculating an estimated remaining time in a simulation of train operation according to an embodiment of the present invention.

Fig. 4 is a flowchart of determining a cruise speed according to a binary method using a preset maximum speed and a preset minimum speed based on a remaining time map and an estimated remaining time calculation according to an embodiment of the present invention.

Fig. 5 is a result diagram of a train operation simulation performed by using the ATO cruise speed real-time optimization scheme provided by the embodiment of the present invention based on the beijing subway data.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may also be present. Further, "connected" or "coupled" as used herein may include wirelessly connected or coupled. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

For the convenience of understanding the embodiments of the present invention, the following description will be further explained by taking several specific embodiments as examples in conjunction with the drawings, and the embodiments are not to be construed as limiting the embodiments of the present invention.

In order to improve the accuracy of a train, reduce the energy consumption of train traction and improve the comfort of passengers, the embodiment of the invention provides a scheme for optimizing the ATO cruising speed in real time according to the actual running condition of the train so as to meet the engineering requirement of ATO second-level adjustment on accurate train control. The second-level adjustment specifically refers to accurate adjustment and control of the running time of the train between stations, for example, 98 seconds are specified, and the ATO reaches the end point in 98 seconds; specifying 102 seconds, the ATO reaches the end 102 seconds.

The processing flow of the method for optimizing the ATO cruising speed in real time meeting the subway second-level adjustment, which is provided by the embodiment of the invention, is shown in figure 1, and comprises the following steps:

step 1, reading various parameters related to train operation, wherein the parameters comprise information such as line gradient, speed limit, train traction and braking characteristics, current train position, speed and residual operation time.

Step 2, calculating the mapping function used by the remaining time mapping as follows:

wherein, t_aTarget running time, t_uFor the current elapsed time, A and B are the mapping coefficients, s_lDistance of current train from destination station, s_tThe station spacing of the train in the current operation (t)_a-t_u) Is the current remaining time division. A and B are determined according to the lower-layer PID control strategy of ATO, A can be a constant value, and the remaining time mapping can be calculated by introducing other functions, such as Sigmoid function.

Fig. 2 shows that in the initial stage of train operation, the remaining time map is smaller than the actual remaining time, and the difference between the actual remaining time and the remaining time map is gradually reduced along with the operation of the train, so that the train has a higher cruising speed in the initial stage of train operation, the train operates at an accelerated speed as much as possible, and the cruising speed is gradually reduced along with the advance of the train, the train is coasting, and finally the train is braked and stopped. Due to the remaining time mapping function, the train can run according to the optimal working condition conversion strategy of 'traction-cruise-coasting-braking' optimized by the maximum value principle, unnecessary braking times are reduced on the premise of meeting the punctuality requirement, and the energy-saving effect is realized.

And 3, performing train operation simulation based on a maximum principle according to the information such as the current train position, the train speed, the train cruising speed, the line basic resistance, the line additional resistance, the train dynamic characteristic, the speed limit and the like, and calculating the estimated remaining time.

For the train operation simulation, the train dynamics model is as follows

Wherein v and x are respectively the running speed and position of the train, u_fAnd u_bThe percentage of the tractive force and the braking force in the maximum tractive force and the maximum braking force is respectively, the value is between 0 and 1, f (v) and b (v) are respectively the maximum tractive force and the maximum braking force of the train, w (v) is the basic resistance in the running process of the train, including friction resistance, air resistance and the like, and g (x) is the additional resistance in the running process, including ramp resistance, bend resistance and the like. The constraint conditions for the speed of the train starting point and the train ending point are as follows:

v(x₀)＝v₀

v(x_T)＝v_T

the train speed v in the running process of the train can not exceed the limit speed V (x)

v≤V(x)

The objective function is:

wherein L is a Lagrangian multiplier and L is greater than 0. The Hamiltonian is:

defining P ═ P/v and substituting it into the hamiltonian, one can obtain

To maximize the Hamiltonian, u_fAnd u_bThe values of (A) are as follows:

1. if p > 1, then u_f＝1，u_bThe maximum traction condition is 0;

2. if p is 1, then u_f∈[0，1]，u_bThe working condition is 0, and the partial traction is performed;

3. if 0 < p < 1, then u_f＝0，u_bSetting the working condition as 0 and idling;

4. if p is 0, then u_f＝0，u_b∈[0，1]Partial braking conditions;

5. if p < 0, then u_f＝0，u_bAnd (5) setting the brake condition as 0 and setting the brake condition as the maximum brake condition.

Taking p as a derivative of x yields:

according to this formula, the following characteristics are provided:

1. part of the braking regime is only used for steep downhill mode in order to meet the speed limit constraint of V ═ V.

2. Under partial traction working condition, the running speed of the train is kept constant, and v is taken as cruising speed v_cAnd the minimum value in the speed limit.

3. Maximum traction condition only applies to (x)₀，x_T) Near a steep uphill or in a region of limited upward speed.

4. The maximum braking condition is applied only to the end of the line or in the area of limited descent, and can be determined by the boundary conditions and v (x).

5. The coasting condition applies to several conditions: a) a region of steep downhill slope, b) before the start of the braking regime, c) steep downhill slope or after the end of partial braking, and the end of the coasting mode is the start of maximum traction or partial traction.

6. Partial traction, partial braking, maximum braking depending on boundary conditions, v_cG (x), v (x), and these four conditions determine the initial position of maximum traction and coasting, but need to be finalized according to the optimality requirements.

FIG. 3 is a diagram illustrating an estimated remaining time t of a train operation simulation according to an embodiment of the present invention_esAs shown in fig. 3, the operation of the train in each ATO control period is regarded as uniform acceleration, based on the maximum principle, the acceleration of the train in each control period is obtained according to parameters such as cruising speed, train information, route information, speed limit, current train position and speed, and the like, and then the estimated remaining time t is calculated_es. The specific treatment process comprises the following steps: reading the current cruising speed, the station spacing, the current position, the current train speed, the current used time, the maximum traction acceleration and the maximum braking acceleration of the train, and initializing and estimating the residual time t_esWill t_esSet to 0, determine that the current train speed is greater than 0 and does not reach the end? If yes, calculating the position t of the train after 0.2s according to the uniform acceleration motion_es＝t_es+0.2. Setting the cruising speed at the next moment as the speed limit when the cruising speed at the next moment is greater than the speed limit, updating the speed of the train after 0.2s according to the cruising speed and the maximum acceleration based on the maximum value principle, judging the speed of the train at the current moment is greater than 0 again and does not reach the terminal point until the train reaches the terminal point, and outputting t_es。

And 4, calculating the cruising speed of the train by using a dichotomy through comparing and estimating the size relation between the remaining time and the remaining time mapping.

The calculation of the train cruising speed is determined using the dichotomy as shown in fig. 4 based on the remaining time map and the estimated remaining time. Firstly, setting the cruising speed as the preset highest speed, and calculating the estimated remaining time under the condition through train operation simulation. If the estimated remaining time is greater than the remaining time map, it is indicated that even if the cruising speed is the highest speed, the time required for the train to travel to the destination station is still greater than the remaining time map, and therefore the cruising speed needs to be set to the preset highest speed, and the cruising speed is output. If the estimated remaining time is not greater than the remaining time map, it is indicated that the cruising speed is the highest speed, the time required for the train to travel to the destination station is not greater than the remaining time map, and therefore the cruising speed does not need to be set to the preset highest speed, and further judgment needs to be carried out.

And setting the cruising speed as the preset lowest speed, carrying out train operation simulation, and calculating the estimated remaining time under the condition. If the estimated remaining time is less than the remaining time map, it is indicated that even if the cruising speed is the preset minimum speed, the required time for the train to travel to the destination station is still less than the remaining time map, and therefore the cruising speed needs to be set to the preset minimum speed, and the cruising speed is output. If the estimated remaining time is not less than the remaining time map, when the cruising speed is the preset lowest speed, the required time for the train to run to the destination station is not less than the remaining time map, so that the cruising speed is not required to be set to the preset lowest speed, and further judgment is required.

The cruise speed is determined using the bisection method, the average of the highest speed and the lowest speed is calculated, the average is taken as the cruise speed, and the estimated remaining time is calculated. And if the difference between the estimated remaining time and the remaining time map is in a given range, the cruising speed enables the train to run to meet the time requirement, and the cruising speed is output. If the difference between the estimated remaining time and the remaining time map is not within the given range, the cruising speed is modified according to the magnitude relation between the estimated remaining time and the remaining time map. If the estimated remaining time is larger than the remaining time mapping, the cruising speed is lower, the lowest speed is set as the current cruising speed, the average value of the highest speed and the lowest speed is calculated again, the bisection method is repeated until the difference between the estimated remaining time and the remaining time mapping is in a given range, and the cruising speed is output. If the estimated remaining time is not greater than the remaining time map, the cruising speed is higher, the highest speed is set as the current cruising speed, the average value of the highest speed and the lowest speed is calculated again, the bisection method is repeated until the difference between the estimated remaining time and the remaining time map is within a given range, and the cruising speed is output.

And 5, outputting the cruising speed of the train.

When outputting the cruising speed of the train, the cruising speed of the train needs to be compared with the speed limit, if the cruising speed of the train is greater than the speed limit, the cruising speed of the train is set as the speed limit and is output, and if the cruising speed of the train is not greater than the speed limit, the cruising speed is directly output.

In the process of optimizing the cruise speed of the ATO in real time by using the embodiment of the invention, a proper cruise speed calculation scheme needs to be selected according to the operational capability of the vehicle-mounted ATO. Updating the recommended cruise speed per cycle with a surplus of computing power; and under the condition of limited computing capacity, starting an additional thread, and updating the cruise speed once in multiple cycles in an asynchronous updating mode.

In conclusion, the invention can improve the punctuality of the train by calculating the mapping of the remaining time and estimating the remaining time and optimizing the ATO cruising speed in real time by using the bisection method, and replace unnecessary braking by using coasting to achieve the effect of energy saving.

The method for optimizing the cruise speed of the ATO in real time based on the embodiment of the invention can calculate the cruise speed in real time, simulate the PID control strategy of the ATO and simulate the running of a train between different stations. Fig. 5 is a running curve obtained by using an ATO cruise speed real-time optimization method when the planned running time is 150s based on the simulation performed by the beijing subway data, wherein the abscissa is the train position (in m) and the ordinate is the speed (in km/h). The simulation gave a run time of 149.70s and an energy consumption of 19.49 kW.h. The result shows that the embodiment of the invention can ensure the punctuality of the train.

In summary, the embodiment of the invention realizes the real-time optimization of the ATO cruise speed, and has the following advantages:

1. and calculating the residual running time mapping according to the line condition in the running process, calculating the estimated residual time through train running simulation according to the current train position, speed, residual running time, line gradient, speed limit, train traction braking characteristics and other information, and calculating the proper cruising speed by using a dichotomy method. Due to the introduction of the remaining time mapping, the train operation process can be represented as a 'fast-slightly fast-punctual' traveling process, and the requirement of operation time division can be met more accurately.

2. According to the performance of the vehicle-mounted ATO, different cruise speed updating modes can be used, and the feasibility of the scheme on different vehicle-mounted computers is ensured.

3. By pre-judging the descending steep slope and the speed-limiting descending point, the vehicle coasts in advance, braking is avoided, the comfort level of passengers is improved, and according to the maximum principle, the working condition conversion mode has a better energy-saving effect.

Those of ordinary skill in the art will understand that: the figures are merely schematic representations of one embodiment, and the blocks or flow diagrams in the figures are not necessarily required to practice the present invention.

From the above description of the embodiments, it is clear to those skilled in the art that the present invention can be implemented by software plus necessary general hardware platform. Based on such understanding, the technical solutions of the present invention may be embodied in the form of a software product, which may be stored in a storage medium, such as ROM/RAM, magnetic disk, optical disk, etc., and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the method according to the embodiments or some parts of the embodiments.

The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for apparatus or system embodiments, since they are substantially similar to method embodiments, they are described in relative terms, as long as they are described in partial descriptions of method embodiments. The above-described embodiments of the apparatus and system are merely illustrative, and the units described as separate parts may or may not be physically separate, and the parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.