A method and system for synchronous control of landing gear retraction and extension of a maglev train
By controlling the landing gear's travel in two stages, the problem of inconsistent landing gear movements during the maglev train's retraction and extension was solved, achieving high-precision synchronous retraction and extension and ensuring the train's safety and stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CRRC CHANGCHUN RAILWAY VEHICLES CO LTD
- Filing Date
- 2026-05-29
- Publication Date
- 2026-07-03
AI Technical Summary
During the retraction and extension of the landing gear of a maglev train, inconsistencies in the hydraulic cylinder's machining precision, sealing condition, pipeline damping, and load distribution can lead to inconsistent movements, affecting the train's stability and safety.
The landing gear travel is controlled in two stages: in the first stage, it moves independently to the segment node at maximum speed, and in the second stage, displacement feedback data is acquired in real time and differential compensation control is performed to ensure that all landing gear reaches the end position synchronously.
It achieves high-precision synchronous retraction and extension of the landing gear, ensuring the safety and stability of train operation, and reducing manufacturing costs and maintenance difficulty.
Smart Images
Figure CN122324072A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of rail transit vehicle control technology, and more specifically, to a method and system for synchronous control of the retraction and extension of the landing gear of a maglev train. Background Technology
[0002] When a maglev train is stationary at a platform, undergoing maintenance, or undergoing emergency braking, it relies on its landing gear to support the train body. During normal operation, the landing gear must retract to reduce air resistance. Therefore, the smooth, reliable, and synchronized retraction and extension of the landing gear is crucial to ensuring train operation safety. If the different landing gears retract or extend at varying speeds or with significant height differences, it could cause the train cars to tilt or even overturn, resulting in a serious accident.
[0003] Landing gear retraction and extension are typically driven by a hydraulic system, with control commands issued centrally by a controller. In traditional designs, the controller usually outputs the same control current to the drive units of the four hydraulic branches, aiming for each landing gear to move at the same speed, thus achieving synchronized retraction and extension. This control method is simple in structure and widely used in the landing gear systems of various rail vehicles.
[0004] However, in practical applications, the machining precision, sealing condition, pipeline damping, and load distribution (such as uneven weight distribution of passengers and cargo within the carriages) of the four landing gears vary. These differences result in different actual moving speeds for each landing gear even when the same control current is input, leading to inconsistent heights during movement and at their final stopping positions. This inconsistency is amplified during high-speed retraction and extension, affecting the stability and safety of the train. Summary of the Invention
[0005] In view of the above, this application provides the following technical solution:
[0006] The first aspect of this application provides a method for synchronous control of the retraction and extension of the landing gear of a magnetic levitation train, including:
[0007] In response to receiving a landing gear retraction / extension command, multiple landing gears are controlled to enter the first movement phase, so that each landing gear moves along the target stroke to a preset segment node;
[0008] Once all landing gears have moved to the segment node, control each landing gear to enter the second movement phase, operating with reference drive parameters lower than those of the first movement phase.
[0009] During the second movement phase, displacement feedback data of each landing gear is acquired in real time, and differential compensation control, such as deceleration or pausing, is performed on the leading landing gear based on the displacement differences between the landing gears, until all landing gears have moved to the end position of the target stroke.
[0010] One possible implementation also includes:
[0011] Once any landing gear reaches the end of the target travel distance, the drive of that landing gear is stopped.
[0012] Once all landing gears have reached the endpoint position, the control process ends.
[0013] In one possible implementation, multiple landing gears are controlled to enter the first movement phase, including:
[0014] The maximum permissible drive signal is output to the drive unit of each landing gear, so that each landing gear moves independently at its own maximum speed;
[0015] When any landing gear is detected to have reached the segment node, the drive of that landing gear is stopped, and the position of the remaining landing gears is continuously monitored until all landing gears have reached the segment node.
[0016] In one possible implementation, differential compensation control, including deceleration or pausing, is performed on the leading landing gear based on the displacement differences between the landing gears, including:
[0017] Calculate the difference between the maximum and minimum values in all current landing gear displacement feedback data to obtain the synchronization deviation value;
[0018] The drive signal strength for the leading landing gear is dynamically adjusted based on the range of the synchronization deviation value.
[0019] In one possible implementation, the drive signal strength for the leading landing gear is dynamically adjusted based on the range of the synchronization deviation value, including:
[0020] When the synchronization deviation value is less than the first preset threshold, the current drive parameters of each landing gear remain unchanged;
[0021] When the synchronization deviation value is greater than or equal to the first preset threshold and less than or equal to the second preset threshold, the drive parameters of the displacement-leading landing gear are reduced.
[0022] When the synchronization deviation value is greater than the second preset threshold, the drive signal of the leading landing gear is cut off.
[0023] One possible implementation also includes:
[0024] After executing the step of cutting off the drive signal of the leading landing gear, if the displacement difference between the other landing gear and the leading landing gear is less than a preset recovery threshold, the drive signal for the leading landing gear is restored.
[0025] In one possible implementation, before entering the second movement phase, the following is also included:
[0026] All landing gear drive parameters were uniformly adjusted to the preset baseline drive parameters.
[0027] The second aspect of this application provides a synchronous control system for the retraction and extension of the landing gear of a magnetic levitation train, including:
[0028] Central controller;
[0029] Multiple independently driven hydraulic circuits, each hydraulic circuit is used to drive a corresponding landing gear;
[0030] Multiple displacement sensors are associated with each landing gear and are used to feed back the displacement data of the corresponding landing gear to the central controller in real time.
[0031] The central controller is configured to execute any of the above-mentioned methods for synchronous control of the landing gear retraction and extension of maglev trains.
[0032] In one possible implementation, the hydraulic branch includes a proportional current drive module and a hydraulic valve, and the central controller changes the driving force of the corresponding hydraulic branch by independently adjusting the control current output to each of the proportional current drive modules.
[0033] In one possible implementation, the central controller is further configured to, after confirming that all landing gears have reached the segment node, uniformly adjust the drive parameters of each hydraulic branch to the reference drive parameters and enter the second movement phase.
[0034] As can be seen from the above technical solutions, the embodiments of this application disclose a method and system for synchronous control of the retraction and extension of the landing gear of a magnetic levitation train. The solution manages the journey in segments, responds quickly in the first stage, and introduces a difference compensation mechanism based on real-time feedback in the second stage. It can achieve high-precision synchronization without completely eliminating individual hardware differences, which not only ensures the efficiency of retraction and extension, but also ensures the consistency of the final retraction and extension height of multiple landing gears, effectively ensuring the safety of train operation. Attached Figure Description
[0035] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.
[0036] Figure 1 This is a flowchart of a synchronous control method for the retraction and extension of the landing gear of a magnetic levitation train disclosed in an embodiment of this application;
[0037] Figure 2 This is a flowchart of the first moving stage disclosed in the embodiments of this application;
[0038] Figure 3 This is a flowchart of the differential compensation control disclosed in an embodiment of this application;
[0039] Figure 4 This is a schematic diagram illustrating the implementation process of the synchronous control method for the retraction and extension of the landing gear of a magnetic levitation train disclosed in this application.
[0040] Figure 5 This is a schematic diagram of the structure of a synchronous control system for the retraction and extension of the landing gear of a magnetic levitation train disclosed in an embodiment of this application. Detailed Implementation
[0041] The technical solutions of 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 of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0042] Figure 1 This is a flowchart illustrating a synchronous control method for the retraction and extension of the landing gear of a magnetic levitation train, as disclosed in an embodiment of this application. See also... Figure 1 As shown, the method may include:
[0043] Step 101: In response to receiving the landing gear retraction and extension command, control multiple landing gears to enter the first movement phase, so that each landing gear moves along the target stroke to the preset segment node.
[0044] When the central controller of the maglev train's landing gear receives the landing gear retraction / extension command, it controls multiple landing gears (typically one central controller can control four landing gears; this article uses four as an example) to enter the first movement phase. In this first movement phase, the controller does not consider synchronization differences between the landing gears, but instead simultaneously outputs the maximum allowable control current (I_max) to the four proportional hydraulic valves driving the four landing gears. At this time, under the action of hydraulic thrust, the four landing gears rush towards node S1 at their maximum achievable speed (V_max) under the current operating conditions. For example, if S_total is 230mm and S1 is set to 120mm, the landing gear will move from the 0mm position to the 120mm position at an extremely fast speed.
[0045] When the system detects that the displacement sensor feedback value of a landing gear (e.g., landing gear 3) reaches or exceeds 120mm, the controller immediately resets the drive current of that landing gear to zero, stopping it at 120mm. At this time, the other landing gears may still be moving. The controller continuously polls the status of the four landing gears until it confirms that the displacement of landing gears 1, 2, 3, and 4 is greater than or equal to 120mm.
[0046] Step 102: After all landing gears have moved to the segment node, control each landing gear to enter the second movement stage, and operate with reference drive parameters lower than those of the first movement stage.
[0047] Once all landing gear units have reached the segment node, the second movement phase can begin. To prevent shocks and uncontrollability caused by high speed, the controller first uniformly reduces the drive current of all landing gear units to a lower reference current (I_base), for example, 60% of I_max. The reference current is configurable and has no fixed limit. At this point, the landing gear units continue to move at a lower speed (V_base). The reference current is also known as the reference drive parameter.
[0048] Step 103: In the second movement phase, the displacement feedback data of each landing gear is acquired in real time, and differential compensation control, such as deceleration or pausing, is performed on the landing gear with the leading displacement based on the displacement difference between each landing gear, until all landing gears have moved to the end position of the target stroke.
[0049] During the second movement phase, the controller activates a high-precision synchronization adjustment mode. The controller acquires data (s1, s2, s3, s4) from four displacement sensors in real time at a fixed frequency (e.g., 100Hz). The system calculates the maximum (s_max) and minimum (s_min) of the four displacement values at the current moment, and obtains the synchronization deviation ΔS = s_max - s_min.
[0050] For example, if it is detected that landing gear 1 moves the fastest (s1 = s_max) while landing gear 3 moves the slowest (s3 = s_min), and ΔS exceeds the preset safety threshold, the controller will only adjust landing gear 1: reduce its drive current (decelerate) or cut off the current directly (pause), while maintaining or appropriately increasing the drive force for landing gear 3, thereby reducing the difference in movement distance between different landing gears.
[0051] Once all landing gears have moved to the end position of the target travel distance, the response action of the retraction / extension command is completed, and the control process ends.
[0052] This embodiment divides the physical travel of the landing gear retraction and extension into stages. The first movement stage utilizes the maximum capacity of the equipment, significantly reducing unnecessary waiting time. The second movement stage dynamically compensates for positional deviations between different landing gears through real-time feedback adjustments, thereby achieving a control logic of first rapidly approaching and then synchronously fine-tuning. This control logic does not require perfect hardware matching, but rather compensates for hardware defects through software algorithms, greatly reducing manufacturing costs and maintenance difficulty, while ensuring the consistency of the final height of multiple landing gears and avoiding the safety risks of vehicle tilting.
[0053] In one implementation, the maglev train landing gear retraction and extension synchronization control method may further include: stopping the drive of any landing gear when it reaches the end position of the target travel; and ending the control process when all landing gears have reached the end position.
[0054] Throughout the second movement phase, the controller continuously monitors the endpoint position. Once it detects that the displacement of any landing gear (e.g., No. 2) reaches 230mm (S_total), the controller immediately cuts off the drive current to landing gear No. 2, bringing it to a stop. At this point, due to the synchronization adjustment, the displacements of the remaining landing gears should also be very close to 230mm. When the last landing gear also reaches 230mm, the controller cuts off all outputs, and the control process ends.
[0055] Alternatively, in some implementations, considering the precise and synchronized adjustment between the landing gears during the second movement phase, once one landing gear reaches its endpoint, the displacements of the remaining landing gears are also very close to their respective endpoints. Therefore, "the first landing gear reaching its endpoint" can be used as the termination signal for the entire process, and the drive of all landing gears can be stopped immediately. In this scenario, even if there are some deviations between the final heights of the different landing gears, these deviations will be very small and will not affect the overall balance of the vehicle or cause it to tilt.
[0056] This embodiment provides different end control implementations for the synchronous control process of the landing gear retraction and extension of a maglev train. In practical applications, different implementations can be selected according to the needs of the scenario.
[0057] Figure 2 This is a flowchart illustrating the first moving stage disclosed in an embodiment of this application. (In conjunction with...) Figure 2 As shown, controlling multiple landing gears to enter the first movement phase can include:
[0058] Step 201: Output the maximum permissible drive signal to the drive unit of each landing gear, so that each landing gear moves independently at its own maximum speed.
[0059] Step 202: When any landing gear is detected to have reached the segment node, stop driving that landing gear and continue to monitor the position of the remaining landing gears until all landing gears have reached the segment node.
[0060] This implementation describes the specific implementation of the first movement phase. In the first movement phase, the controller's control objective is to "reach the assembly point as quickly as possible," which is the segmentation phase, rather than "maintain formation," meaning that it does not guarantee that the starting distances of each landing gear are strictly the same.
[0061] For example, the controller controls the output of the maximum drive current to each hydraulic branch. Assuming that due to the difference in mechanical friction, although landing gear No. 1 receives the maximum current, its acceleration is slightly lower due to jamming; while landing gear No. 4 accelerates the fastest due to its lighter load.
[0062] At time t1, landing gear #4 is the first to touch segment node S1 (120mm). Upon receiving this signal, the controller immediately executes an "independent stop" command, shutting down the drive channel corresponding to landing gear #4. At this point, landing gears #1, #2, and #3 may be at 118mm, 119mm, and 117mm respectively. The controller does not stop and wait for landing gear #4 to reach its position; instead, it continues to maintain full-current drive for landing gears #1, #2, and #3.
[0063] At time t2, landing gears 3 and 2 arrive at S1 successively, and the controller sequentially cuts off their drive. Finally, by time t3, landing gear 1 has also moved to 120mm. At this point, the controller determines that all landing gears have reached the segment node.
[0064] In this embodiment, during the first movement phase, the controller controls the landing gear to move to the segment node at maximum speed and controls the landing gear that arrives at the segment node first to "wait" for the landing gear that arrives later. This ensures that before the second movement phase begins, all landing gears are on the same starting line (S1 node), providing a unified initial state for subsequent fine-tuning and preventing adjustment difficulties caused by dispersed initial positions, as well as the cumulative amplification of deviations.
[0065] Figure 3 This is a flowchart illustrating the differentiated compensation control disclosed in an embodiment of this application. See also... Figure 3 In one implementation, differential compensation control, which involves decelerating or pausing the landing gear that is leading in displacement, is performed based on the displacement differences between the landing gears. This can include:
[0066] Step 301: Calculate the difference between the maximum and minimum values in the displacement feedback data of all landing gears to obtain the synchronization deviation value.
[0067] Step 302: Based on the range of the synchronization deviation value, dynamically adjust the drive signal strength of the landing gear that leads the displacement.
[0068] For example, if the maximum value is Max and the minimum value is Min, then the synchronization deviation value ΔS = Max – Min. This ΔS value is the core criterion for the entire synchronization control, intuitively reflecting the dispersion of the four landing gears. The controller does not need to know the specific position of each landing gear, only the relative distance between them. Through the extremely simple calculation of the ΔS value, the system can quickly and accurately assess the overall synchronization status. This method has low computational requirements and low computing power requirements for the controller, making it suitable for real-time operation in embedded systems.
[0069] Specifically, dynamically adjusting the drive signal strength of the leading landing gear based on the range of the synchronization deviation value can include: maintaining the current drive parameters of each landing gear unchanged when the synchronization deviation value is less than a first preset threshold; reducing the drive parameters of the leading landing gear when the synchronization deviation value is greater than or equal to the first preset threshold and less than or equal to a second preset threshold; and cutting off the drive signal of the leading landing gear when the synchronization deviation value is greater than the second preset threshold.
[0070] For example, the first preset threshold is 5mm, and the second preset threshold is 10mm.
[0071] Scenario A (Good Synchronization): If ΔS = 3mm (less than 5mm), the system determines that the four landing gears are synchronized and no intervention is required. The controller maintains the current reference current I_base output on all channels without making any adjustments to avoid oscillations caused by frequent adjustments.
[0072] Scenario B (Slight Asynchrony): If ΔS = 8mm (between 5mm and 10mm), the system determines a slight asynchronous trend. In this case, the controller locks the landing gear with the largest displacement value (e.g., C). The controller reduces the drive current corresponding to landing gear C from I_base by 20% (i.e., multiplied by a factor of 0.8). The remaining three landing gears, A, B, and D, maintain their original currents. This slows down landing gear C, giving A, B, and D a chance to catch up.
[0073] Scenario C (Severe Asynchrony): If ΔS = 15mm (greater than 10mm), the system determines the asynchrony is severe and poses a safety risk. The controller immediately performs an "emergency stop" operation on landing gear C, which has the largest displacement, directly cutting off its drive current to 0. Landing gear C stops moving, while landing gears A, B, and D continue to move. Only when A, B, and D catch up, causing ΔS to fall back to the safe range, will C be reauthorized to move.
[0074] The graded adjustment mechanism disclosed in this embodiment achieves adaptive matching between control intensity and deviation degree. For minor deviations, no intervention is required to maintain stability; for moderate deviations, slight deceleration is used to correct them; for large deviations, the system is decisively stopped to avoid risks. This strategy ensures both rapid adjustment and avoids system jitter caused by "one-size-fits-all" control, significantly improving the ride comfort and equipment lifespan of the maglev train.
[0075] Based on the aforementioned disclosure, the solution may further include: after executing the step of cutting off the drive signal of the leading landing gear, if the displacement difference between the other landing gear and the leading landing gear is detected to be less than a preset recovery threshold, then the drive signal for the leading landing gear is restored.
[0076] Continuing with scenario C of the aforementioned embodiment, when landing gear C is brought to an emergency stop, its displacement is 160mm, while the other three are at 145mm. As landing gears A, B, and D move, at time t4, A reaches 159mm, B reaches 158.5mm, and D reaches 158mm. At this point, the maximum difference ΔS decreases to 2mm (160-158), which is less than the first preset threshold of 5mm.
[0077] At this point, if landing gear C remains stationary, it is safe but inefficient. Therefore, the controller can reactivate the drive signal for landing gear C when the distance between the "fastest" and "slowest" landing gears is less than the recovery threshold (e.g., 3mm). To prevent landing gear C from suddenly lurching forward again, the current supplied to landing gear C during recovery is not I_base, but is set based on the fastest current value among the other three paths, ensuring that landing gear C moves at a suitable speed instead of widening the gap again.
[0078] This embodiment provides a method for resuming movement of the landing gear after it has been stopped by a flow interruption. This ensures that after correcting a serious deviation of an individual landing gear, the stopped landing gear can quickly return to a normal state of synchronous operation with other landing gears. This prevents the system from being hindered by a single emergency stop and optimizes the overall landing gear retraction and extension time.
[0079] In one implementation, the landing gear retraction and extension synchronization control scheme of a maglev train may include, before entering the second movement stage, adjusting all landing gear drive parameters to a preset reference drive parameter.
[0080] In practical applications, the arrival times of multiple landing gears controlled by the controller at the segment nodes may differ. For example, landing gear #4 may arrive earliest, while landing gear #1 may arrive latest, with a time difference of several hundred milliseconds between them. To ensure fairness in the second movement phase, once the system detects that all landing gears have reached the segment node, the controller will forcibly perform a "normalization" operation. That is, regardless of the previous current values of each circuit (which could be I_max or 0), the controller will forcibly adjust the drive parameters of each hydraulic branch to the preset reference drive parameters.
[0081] This implementation ensures that the driving force on each landing gear is completely consistent at the start of the second movement phase, eliminating the asymmetry of the initial conditions and laying the foundation for subsequent high-precision synchronous adjustment.
[0082] Figure 4 This is a schematic diagram illustrating the implementation process of the synchronous control method for the retraction and extension of the landing gear of a maglev train disclosed in this application, which includes the contents of the aforementioned embodiments and can be combined with... Figure 4 Understand the relevant content of the previous embodiments.
[0083] In summary, the main technical contents of this application are as follows:
[0084] 1. Dynamic difference compensation based on real-time displacement comparison: Instead of relying on establishing a complex and accurate uniform model for each actuator, it directly implements targeted deceleration or pausing control on the "fastest" individual by comparing the feedback values of four displacement sensors in real time. The method is direct, effective and robust.
[0085] 2. Graded threshold adjustment mechanism: During the synchronous fine-tuning stage, two displacement difference thresholds (5mm and 10mm) are set, and corresponding to two different intensity compensation measures, namely "deceleration fine-tuning" and "emergency stop waiting", which realizes the adaptive matching between control response and deviation degree. It can quickly correct deviation and avoid over-adjustment or frequent start-stop.
[0086] 3. Segmented control strategy: The entire process is divided into two stages: "high-speed approach" and "synchronous fine adjustment". This creates conditions for achieving high-precision synchronization while ensuring overall efficiency.
[0087] 4. Final Consistency Guarantee: The control process involves cutting off the drive of the corresponding landing gear after reaching the endpoint position, until all landing gears have reached the endpoint position, effectively ensuring the consistency of the final height of each landing gear.
[0088] For the foregoing method embodiments, in order to simplify the description, they are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, because according to this application, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to this application.
[0089] Figure 5 This is a schematic diagram of the structure of a synchronous control system for the retraction and extension of the landing gear of a magnetic levitation train, as disclosed in an embodiment of this application. See also... Figure 5 As shown, the maglev train landing gear retraction and extension synchronization control system may include:
[0090] Central controller 51;
[0091] Multiple independently driven hydraulic circuits 52, each hydraulic circuit is used to drive a corresponding landing gear;
[0092] Multiple displacement sensors 53 are associated with each landing gear and are used to feed back the displacement data of the corresponding landing gear to the central controller in real time.
[0093] The central controller is configured to execute any of the magnetic levitation train landing gear retraction and extension synchronization control methods described in the foregoing embodiments.
[0094] Figure 5 In this paper, the number of hydraulic branches, displacement sensors and landing gear is shown as 4. In actual applications, the number of landing gear controlled by a central control unit, as well as the corresponding number of hydraulic branches and displacement sensors, can be other values. This application does not impose any fixed restrictions on this.
[0095] The central controller can be an industrial PLC or a microcontroller, has multiple input and output interfaces, and is responsible for running control algorithms and processing logical judgments.
[0096] The hydraulic branch circuit may include a proportional current drive module and a hydraulic valve. The central controller changes the driving force of the corresponding hydraulic branch circuit by independently adjusting the control current output to each of the proportional current drive modules.
[0097] In one implementation, the central controller is further configured to, after confirming that all landing gears have reached the segment node, uniformly adjust the drive parameters of each hydraulic branch to the reference drive parameters and enter the second movement phase.
[0098] The maglev train landing gear retraction and extension synchronization control system disclosed in this application adopts a "one-control-many" distributed drive mode, with each hydraulic drive branch operating independently without interference. The central controller can coordinate the control of multiple hydraulic drive branches, enabling the control to utilize the maximum capacity of the equipment during the first movement phase, significantly reducing ineffective waiting time. During the second movement phase, control uses real-time feedback adjustment to dynamically compensate for positional deviations between different landing gears, thus achieving a control logic of rapid convergence followed by precise synchronization. This scheme ensures the consistency of the final height of multiple landing gears, avoiding the safety risks of train tilting.
[0099] This application also discloses a synchronous control device for the retraction and extension of the landing gear of a magnetic levitation train, including:
[0100] The first control module is used to respond to the received landing gear retraction and extension command, control multiple landing gears to enter the first movement stage, so that each landing gear moves along the target stroke to the preset segment node;
[0101] The second control module is used to control each landing gear to enter a second movement phase after all landing gears have moved to the segment node, and to operate with reference drive parameters lower than those of the first movement phase; during the second movement phase, it is used to acquire displacement feedback data of each landing gear in real time, and to perform differential compensation control to decelerate or pause the leading landing gear according to the displacement difference between the landing gears, until all landing gears have moved to the end position of the target stroke.
[0102] The magnetic levitation train landing gear retraction and extension synchronization control device described in the above embodiments includes a processor and a memory. The first control module and the second control module in the above embodiments are both stored as program modules in the memory, and the processor executes the program modules stored in the memory to realize the corresponding functions.
[0103] The processor contains a kernel, which retrieves the corresponding program modules from memory. One or more kernels can be configured, and the processing of backtracking data can be achieved by adjusting kernel parameters.
[0104] The memory may include non-permanent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.
[0105] In an exemplary embodiment, a computer-readable storage medium is also provided, which can be directly loaded into the internal memory of a computer and contains software code. After being loaded and executed by the computer, the computer program can realize the steps shown in any embodiment of the above-described synchronous control method for the retraction and extension of the landing gear of a magnetic levitation train.
[0106] In an exemplary embodiment, a computer program product is also provided, which can be directly loaded into the internal memory of a computer and contains software code. After being loaded and executed by the computer, the computer program can realize the steps shown in any embodiment of the above-described synchronous control method for the retraction and extension of the landing gear of a magnetic levitation train.
[0107] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.
[0108] It should also be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0109] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.
[0110] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A method for synchronous control of the retraction and extension of the landing gear of a magnetic levitation train, characterized in that, include: In response to receiving a landing gear retraction / extension command, multiple landing gears are controlled to enter the first movement phase, so that each landing gear moves along the target stroke to a preset segment node; Once all landing gears have moved to the segment node, control each landing gear to enter the second movement phase, operating with reference drive parameters lower than those of the first movement phase. During the second movement phase, displacement feedback data of each landing gear is acquired in real time, and differential compensation control, such as deceleration or pausing, is performed on the leading landing gear based on the displacement differences between the landing gears, until all landing gears have moved to the end position of the target stroke.
2. The method for synchronous control of landing gear retraction and extension of a maglev train according to claim 1, characterized in that, Also includes: Once any landing gear reaches the end of the target travel distance, the drive of that landing gear is stopped. Once all landing gears have reached the endpoint position, the control process ends.
3. The method for synchronous control of landing gear retraction and extension of a magnetic levitation train according to claim 1, characterized in that, Controlling multiple landing gears to enter the first movement phase includes: The maximum permissible drive signal is output to the drive unit of each landing gear, so that each landing gear moves independently at its own maximum speed; When any landing gear is detected to have reached the segment node, the drive of that landing gear is stopped, and the position of the remaining landing gears is continuously monitored until all landing gears have reached the segment node.
4. The method for synchronous control of landing gear retraction and extension of a magnetic levitation train according to claim 1, characterized in that, Based on the displacement differences between the landing gears, differentiated compensation control is implemented for the leading landing gear to decelerate or pause, including: The difference between the maximum and minimum values in the displacement feedback data of all landing gears is calculated to obtain the synchronization deviation value; The drive signal strength for the leading landing gear is dynamically adjusted based on the range of the synchronization deviation value.
5. The method for synchronous control of landing gear retraction and extension of a maglev train according to claim 4, characterized in that, Based on the range of the synchronization deviation value, the drive signal strength of the leading landing gear is dynamically adjusted, including: When the synchronization deviation value is less than the first preset threshold, the current drive parameters of each landing gear remain unchanged; When the synchronization deviation value is greater than or equal to the first preset threshold and less than or equal to the second preset threshold, the drive parameters of the displacement-leading landing gear are reduced. When the synchronization deviation value is greater than the second preset threshold, the drive signal of the leading landing gear is cut off.
6. The method for synchronous control of landing gear retraction and extension of a maglev train according to claim 5, characterized in that, Also includes: After executing the step of cutting off the drive signal of the leading landing gear, if the displacement difference between the other landing gear and the leading landing gear is less than a preset recovery threshold, the drive signal for the leading landing gear is restored.
7. The method for synchronous control of landing gear retraction and extension of a maglev train according to claim 1, characterized in that, Before entering the second movement phase, it also includes: All landing gear drive parameters were uniformly adjusted to the preset baseline drive parameters.
8. A synchronous control system for the retraction and extension of landing gear of a magnetic levitation train, characterized in that, include: Central controller; Multiple independently driven hydraulic circuits, each hydraulic circuit is used to drive a corresponding landing gear; Multiple displacement sensors are associated with each landing gear and are used to feed back the displacement data of the corresponding landing gear to the central controller in real time. The central controller is configured to perform the synchronous control method for the retraction and extension of the landing gear of a maglev train as described in any one of claims 1-7.
9. The magnetic levitation train landing gear retraction and extension synchronous control system according to claim 8, characterized in that, The hydraulic branch circuit includes a proportional current drive module and a hydraulic valve. The central controller changes the driving force of the corresponding hydraulic branch circuit by independently adjusting the control current output to each of the proportional current drive modules.
10. The magnetic levitation train landing gear retraction and extension synchronous control system according to claim 8, characterized in that, The central controller is also used to adjust the drive parameters of each hydraulic branch to the reference drive parameters after confirming that all landing gears have reached the segment node, and then enter the second movement stage.