A method of brake control for a locomotive

Abstract

The application relates to a brake control method of a locomotive, which comprises the following steps: detecting the level of a home / auxiliary state pressure switch output; detecting the speed of the locomotive; and determining whether brake control is performed according to the detected level of the home / auxiliary state pressure switch output and the speed of the locomotive; wherein the detection of the level of the home / auxiliary state pressure switch comprises the following steps: within N seconds after the completion of the startup of a brake control unit (BCU), if the output of the home / auxiliary state pressure switch is detected as low level, the BCU judges that the brake is in the home position; if the output of the home / auxiliary state pressure switch is detected as high level, the BCU judges that the brake is in the auxiliary position; after N seconds of the completion of the startup of the BCU, if the output of the home / auxiliary state pressure switch is detected as low level, the BCU judges that the brake is in the home position; and when the output of the home / auxiliary state pressure switch is high level and the speed of the locomotive is zero, the BCU judges that the brake is in the auxiliary position. The application solves the problem that the false action of the home / auxiliary state pressure switch influences the accuracy of brake control in the prior art.

Description

Technical Field

[0001] This invention belongs to the field of rail transit technology, and in particular relates to a braking control method for locomotives. Background Technology

[0002] The basic / complementary state settings of brakes are crucial for train braking operations. In railway transportation systems, brakes are typically used to control the braking force of trains to ensure safe operation. The basic / complementary state of brakes determines their behavior during braking operations; therefore, correct basic / complementary state settings are essential for train braking performance.

[0003] The operating reconnection valve is a key component of the braking system, responsible for controlling the primary / secondary status of the brake. The primary / secondary status switch is an important element on the operating reconnection valve, and its state affects the output signal of the primary / secondary status pressure switch. Specifically, when the primary / secondary status switch of the operating reconnection valve is set to the primary position, the primary / secondary status pressure switch outputs a low-level signal; while when the primary / secondary status switch of the operating reconnection valve is set to the secondary position, the primary / secondary status pressure switch outputs a high-level signal. These different signal levels are used to determine the primary / secondary status of the brake.

[0004] The output signal of the pressure switch for the primary / secondary status is not only collected by the brake control unit (BCU) of the brake and used for primary / secondary status judgment, but also input to the rear shut-off valve to ensure that the rear shut-off valve is energized. The purpose of this measure is to prevent pressure reduction in the train pipe when the BCU of the auxiliary brake position experiences abnormal power loss, thereby ensuring that the power loss of the BCU of the auxiliary brake position will not affect train operation.

[0005] However, it is important to note that both the primary / secondary status switch and the primary / secondary status pressure switch of the multiple-connection valve are susceptible to malfunction. If a malfunction occurs, it will affect the brake's primary / secondary status determination and may lead to the disconnection of the train pipe. Therefore, ensuring the reliability and accuracy of these switches is crucial to maintaining the normal operation of the train braking system. Summary of the Invention

[0006] In view of the shortcomings of related technologies, the present invention provides a braking control method for locomotives, which solves the technical problem that the malfunction of the pressure switch in the normal / complementary state affects the accuracy of braking control.

[0007] According to one aspect of this application, a braking control method for a locomotive is provided. The method includes the following steps: detecting the output level of a local / complementary status pressure switch; detecting the locomotive speed; and determining whether braking control should be performed based on the detected output level of the local / complementary status pressure switch and the locomotive speed. Detecting the output level of the local / complementary status pressure switch includes: within N seconds after the brake control unit (BCU) is powered on and completes startup, if the local / complementary status pressure switch outputs a low level, the BCU determines that the brake is in local position; if the local / complementary status pressure switch outputs a high level, the BCU determines that the brake is in supplementary position; after N seconds after the BCU is powered on and completes startup, if the local / complementary status pressure switch outputs a low level, the BCU determines that the brake is in local position; when the local / complementary status pressure switch outputs a high level and the locomotive speed is zero, the BCU determines that the brake is in supplementary position.

[0008] In one possible implementation, based on the above braking control method, it further includes: when the BCU is powered on and completes the start-up for N seconds, if it detects that the output of the local / supplementary state pressure switch changes from low level to high level and the locomotive speed is not zero, then the BCU determines that the locomotive's brake is in local position.

[0009] In one possible implementation, based on the above braking control method, when the BCU is powered on and completes the start-up for N seconds, if it detects that the output of the local / compensation state pressure switch changes from low level to high level and the locomotive speed is not zero, then the BCU determines that the locomotive's brake is in its local position and controls the locomotive's brake to trigger penalty braking.

[0010] In one possible implementation, after the locomotive's brakes trigger penalty braking, the pressure in the train pipe is detected. If the pressure in the train pipe is less than the set pressure of 60 kPa, emergency braking is not initiated.

[0011] In one possible implementation, when the pressure in the train pipe is greater than or equal to the constant pressure of 60 kPa, the train pipe pressure P1 and the detection time t1 are recorded; after t1+n seconds, the train pipe pressure P2 is detected; when P1-P2≥30 kPa, the train's brakes are controlled to perform emergency braking and a fault is indicated.

[0012] In one possible implementation, when the train's brakes do not guide emergency braking or after emergency braking has been performed, the train's speed is detected; when the train's speed is zero, the penalty braking of the train's brakes is canceled.

[0013] In one possible implementation, if the train's brakes do not guide emergency braking or after emergency braking, and the train speed is not zero, a fault-free reset is performed and the fault is cleared if the following conditions exist: the train pipe pressure is >450 kPa when the train is in operation, or it is a single unit or a supplementary unit.

[0014] In one possible implementation, when the train's brakes are used for emergency braking, the train pipe is depressurized by 130 kPa.

[0015] In one possible implementation, the BCU filters the acquired local / complementary state pressure switch signal, and the time N seconds is greater than the filtering time of the BCU for the local / complementary state pressure switch signal.

[0016] In one possible implementation, if the local / compensation status pressure switch outputs a low level within N seconds after the brake control unit (BCU) is powered on and starts, and if the local / compensation status pressure switch outputs a high level after N seconds after the BCU is powered on and starts, while the locomotive speed is zero, then it is determined that the local / compensation status pressure switch has malfunctioned; and the output level of the local / compensation status pressure switch within N seconds after power-on and after N seconds is re-detected.

[0017] Based on the above technical solution, the braking control method based on locomotive basic / complementary state judgment of the present invention further confirms the state of the brake by differentiating the interpretation of the basic / complementary state pressure switch signal of the BCU at different time nodes and combining it with the detection of locomotive speed, thereby making a more accurate judgment on the state of the locomotive and improving the control accuracy. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0019] Figure 1 A schematic flowchart of a locomotive braking control method according to one embodiment;

[0020] Figure 2 This is a flowchart illustrating a braking control method for a locomotive according to another embodiment. Detailed Implementation

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0022] In the description of this invention, it should be understood that the terms "center", "lateral", "longitudinal", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0023] The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," or "third" may explicitly or implicitly include one or more of that feature.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] To address the problem of inaccurate braking control caused by malfunctioning pressure switches in existing technologies, this application provides a braking control method for locomotives.

[0026] See Figure 1 In one possible implementation, the method includes the following steps: detecting the output level of the local / complementary state pressure switch; detecting the locomotive speed; and determining whether braking control is performed based on the detected output level of the local / complementary state pressure switch and the locomotive speed; wherein, detecting the output level of the local / complementary state pressure switch includes: within N seconds after the brake control unit (BCU) is powered on and starts up, if the local / complementary state pressure switch outputs a low level, the BCU determines that the brake is in the local position; if the local / complementary state pressure switch outputs a high level, the BCU determines that the brake is in the supplementary position; if the local / complementary state pressure switch outputs a low level after the BCU is powered on and starts up for N seconds, the BCU determines that the brake is in the local position; when the local / complementary state pressure switch outputs a high level and the locomotive speed is zero, the BCU determines that the brake is in the supplementary position.

[0027] In the above scheme, by differentiating the interpretation of the local / complementary state pressure switch signal by the BCU at different time points, the brake's state can be identified more accurately. For example, within N seconds (including N seconds) and after N seconds, the BCU determines the brake's state based on the level changes of the local / complementary state pressure switch, enhancing the system's stability and reliability. Furthermore, combining this with locomotive speed detection can further confirm the brake's state, especially the logic for determining the brake as a supplementary position when the speed is zero, which helps provide more accurate state judgment. Here, N is greater than or equal to 1.

[0028] In one possible implementation, based on the above braking control method, it further includes: when the BCU is powered on and completes the start-up for N seconds, if it detects that the output of the local / supplementary state pressure switch changes from low level to high level and the locomotive speed is not zero, then the BCU determines that the locomotive's brake is in local position.

[0029] In the above implementation, the BCU monitors the level change of the pressure switch for the primary / secondary status (from low to high) and combines this information with vehicle speed information to determine the brake status. This step increases the system's dynamic response capability, enabling more accurate determination of whether the brake is in primary or secondary position during operation, especially when the vehicle speed is non-zero. This is crucial for ensuring safe train operation, particularly at high speeds or under complex road conditions, where accurate brake control judgment is essential.

[0030] In one possible implementation, based on the above braking control method, when the BCU is powered on and completes the start-up for N seconds, if it detects that the output of the local / compensation state pressure switch changes from low level to high level and the locomotive speed is not zero, then the BCU determines that the locomotive's brake is in its local position and controls the locomotive's brake to trigger penalty braking.

[0031] In the above implementation, when the BCU determines that the brake is in its correct position, it immediately triggers the penalty brake. This design aims to improve safety. Especially when the locomotive's speed is not zero, the rapid-response penalty brake can effectively avoid potential safety risks. Furthermore, the penalty brake triggering mechanism can respond quickly, ensuring immediate safety control of the train. This rapid response mechanism is particularly important in emergency situations.

[0032] In one possible implementation, after the locomotive's brakes trigger penalty braking, the pressure in the train pipe is detected. If the pressure in the train pipe is less than the set pressure of 60 kPa, emergency braking is not initiated.

[0033] In the above implementation, the detection of train pipe pressure is combined with the penalty braking triggering mechanism, and the key to this process lies in the measurement of train pipe pressure. When the pressure is less than 60 kPa, the braking system will not trigger emergency braking. This logic ensures that unnecessary emergency braking is avoided in non-critical situations, reducing potential impact on the locomotive and passengers. This method ensures safety while also considering passenger comfort and train operational efficiency.

[0034] In one possible implementation, when the pressure in the train pipe is greater than or equal to the constant pressure of 60 kPa, the train pipe pressure P1 and the detection time t1 are recorded; after t1+n seconds, the train pipe pressure P2 is detected; when P1-P2≥30 kPa, the train's brakes are controlled to perform emergency braking and a fault is indicated. Wherein, n is greater than or equal to 1.

[0035] In the above scheme, the continuous monitoring of train pipe pressure and the emergency braking triggering mechanism provide a dynamic and highly responsive safety measure. By recording pressure P1 and the corresponding time t1, and then detecting pressure P2 again after a specified time, the system can determine whether emergency braking is necessary based on pressure changes. When the difference between P1 and P2 reaches or exceeds 30 kPa, emergency braking is triggered and a fault is indicated. This not only ensures passenger safety but also improves the efficiency of fault diagnosis.

[0036] In one possible implementation, when the train's brakes do not guide emergency braking or after emergency braking has been performed, the train's speed is detected; when the train's speed is zero, the penalty braking of the train's brakes is canceled.

[0037] In the above implementation, the combination of speed detection and penalty braking cancellation mechanism provides a flexible safety control strategy. When the train speed drops to zero, the system will automatically cancel the penalty braking. This strategy not only ensures the safety of the train when stationary, but also avoids unnecessary braking force, helping to protect the integrity of the braking system and the stability of long-term operation.

[0038] In one possible implementation, if the train's brakes do not guide emergency braking or after emergency braking, and the train speed is not zero, a fault-free reset is performed and the fault is cleared if the following conditions exist: the train pipe pressure is >450 kPa when the train is in operation, or it is a single unit or a supplementary unit.

[0039] In the above implementation, when the train is running and its speed is not zero, the BCU monitors the train pipe pressure. If the pressure exceeds 450 kPa, or if the train is in a stand-alone or auxiliary engine state, a fault clearing operation will be automatically performed. This design provides an efficient fault management mechanism that can promptly clear fault codes while the train is running, ensuring the normal operation of the train braking system and reducing the safety risks that may be caused by the accumulation of faults.

[0040] In one possible implementation, when the train's brakes are used for emergency braking, the train pipe is depressurized by 130 kPa.

[0041] In the above scheme, when emergency braking is required, the BCU controls the train tube to depressurize to 130 kPa. This depressurization operation can quickly and effectively increase braking force to cope with emergencies. The 130 kPa depressurization amount is precisely calculated to balance the needs of emergency braking and the safety of the system, ensuring rapid deceleration in emergencies while avoiding excessive pressure on the braking system.

[0042] In one possible implementation, the BCU filters the acquired local / complementary state pressure switch signal, and the time N seconds is greater than the filtering time of the BCU for the local / complementary state pressure switch signal.

[0043] In the above implementation, the BCU filters the pressure switch signal for the primary / secondary state to improve signal reliability and accuracy. The filtering time is crucial; it needs to be longer than N seconds to ensure the signal has been properly smoothed before being read and analyzed by the BCU, reducing the impact of spurious signals or noise. This filtering is essential for accurately identifying the brake's state, especially in complex or changing operating environments.

[0044] In one possible implementation, if a low-level output is detected from the local / complementary state pressure switch within N seconds after the brake control unit (BCU) has been powered on and started, and if a low-level output is detected from the local / complementary state pressure switch N seconds after the BCU has been powered on and started, then the local / complementary state pressure switch is determined to have malfunctioned. After the malfunction, the output level of the local / complementary state pressure switch within N seconds after power-on and N seconds after the malfunction is detected again.

[0045] In the above implementation, when the BCU detects that the pressure switch in both the primary and secondary states is outputting a low level at different time points (within N seconds and after N seconds after power-on), the system will determine that this is an abnormal situation. This design improves the system's fault detection capability, enabling timely identification and response to abnormal actions of the pressure switch. Once an abnormality is detected, the system will re-check the state within N seconds and after N seconds after power-on to ensure accuracy and reliability. This redundant detection mechanism increases the system's robustness and ensures reliable operation in complex environments.

[0046] See Figure 2 The locomotive control method of this application performs braking control based on the locomotive's local state judgment, and the control logic is as follows:

[0047] (1) Within N seconds after the BCU is powered on and starts up, if the pressure switch of the local / compensation state outputs a low level, the BCU will determine that the brake is in the local position; if the pressure switch of the local / compensation state outputs a high level, the BCU will determine that the brake is in the compensation position.

[0048] (2) After the BCU is powered on and completes the start-up for N seconds, the pressure switch of the local / compensation state outputs a low level, and the BCU determines that the brake is in the local position; when the locomotive is at zero speed and the pressure switch of the local / compensation state outputs a high level, the BCU determines that the brake is in the compensation position.

[0049] (3) When the brake is in its original position and the locomotive is not at zero speed, the output signal of the original / compensation pressure switch changes from low level to high level. The brake actively generates penalty braking, and the pressure in the guide train pipe is reduced by 130 kPa.

[0050] (4) When point (3) occurs, record the train pipe pressure P1 at this time (record only once). If P1 < (constant pressure - 60), there is no guidance (no guidance emergency braking); otherwise, record the train pipe pressure P2 after 7 seconds. When P1 < 30 + P2 kPa, guide emergency braking and indicate the fault.

[0051] (5) If point (3) is not met, the penalty source disappears. When the train pipe pressure in the operating position is >450kPa or when the machine is running alone or as a supplementary machine, the fault is cleared.

[0052] (6) Regarding point (1), the BCU performs filtering on the collected local / supplementary state pressure switch signal, so the time of point (1) must be greater than the filtering time of the BCU on the collected local / supplementary state pressure switch signal.

[0053] (7) Regarding point (2), if the locomotive is in a non-zero speed state while running, and the output signal of the local / supplementary state pressure switch changes from low level to high level, then the brake will remain in its original position. Since the brake state change needs to be implemented when the locomotive is in a zero speed state, it is considered that the output signal of the local / supplementary state pressure switch changes from low level to high level at this time as an abnormal action.

[0054] (8) When the auxiliary brake is abnormally powered off and restarted during operation, if the locomotive is still not at zero speed after the BCU is fully started, the brake cannot be set as the auxiliary brake according to point (2). Therefore, point (1) is required to close the condition. Within N seconds after the BCU starts, the local / auxiliary status is determined according to the pressure switch signal of the local / auxiliary status.

[0055] (9) According to point (7), if the pressure switch of the main / supplementary state changes from low level to high level under non-zero speed conditions and the brake machine's own state, it is considered to be an abnormal situation and may block the train pipe, making the train pipe unable to depressurize, causing safety hazards. Therefore, the brake machine triggers penalty braking to actively depressurize. If it cannot depressurize, it triggers emergency braking.

[0056] (10) According to point (4), if P1 < (constant pressure - 60), then it is considered that condition (3) occurred after the train pipe was depressurized by 60 kPa, the train pipe has been depressurized and there is no safety hazard, so there is no need to trigger emergency braking at this time.

[0057] (11) According to point (4), if P1 ≥ (constant pressure - 60), it is considered that when condition (3) occurs, the train pipe has not reached the pressure reduction of 60 kPa, and there is a safety hazard of insufficient braking force. Record the train pipe pressure P2 after 7 seconds. If P1 < 30 + P2 kPa, it is considered that the train pipe has indeed been cut off, and the emergency braking is guided to reduce the train pipe pressure to 0 kPa through the emergency braking path.

[0058] This application provides a locomotive that applies the braking control method of any of the above embodiments.

[0059] The locomotive braking control method of this application performs braking control based on the locomotive's basic / complementary status and speed judgment. It addresses the basic / complementary status settings of the brake system at startup and after startup, as well as the basic / complementary status setting scheme during operation, to avoid the impact on the basic / complementary status judgment of the brake system when the multiple-connection valve basic / complementary status switch and basic / complementary status pressure switch malfunction.

[0060] Furthermore, in response to the malfunction of the primary / secondary state switch and the primary / secondary state pressure switch of the multiple-connection valve, a safety guidance logic is designed to prevent major safety hazards caused by the inability of the train pipe to depressurize.

[0061] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0062] The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A braking control method for a locomotive, characterized in that, Includes the following steps: Detect the output level of the pressure switch in the current / complementary state; To detect the speed of the locomotive; and, Whether to control braking is determined based on the level output of the pressure switch in the detected local / supplementary state and the locomotive speed; The detection level of the pressure switch output for the local / complementary status includes: within N seconds after the brake control unit (BCU) is powered on and starts up, if the pressure switch outputs a low level, the BCU determines that the brake is in the local position; if the pressure switch outputs a high level, the BCU determines that the brake is in the supplementary position. After the BCU is powered on and completes startup for N seconds, if the local / compensation status pressure switch is detected to be low, the BCU determines that the brake is in local position; if the local / compensation status pressure switch is high and the locomotive speed is zero, the BCU determines that the brake is in compensation position.

2. The braking control method according to claim 1, characterized in that, Also includes: After the BCU is powered on and completes startup for N seconds, if it detects that the output of the local / supplementary status pressure switch changes from low level to high level and the locomotive speed is not zero, then the BCU determines that the locomotive's brake is in local position.

3. The braking control method according to claim 2, characterized in that, After the BCU is powered on and completes startup for N seconds, if it detects that the output of the local / compensation status pressure switch changes from low level to high level and the locomotive speed is not zero, then the BCU determines that the locomotive's brake is in local position and also controls the locomotive's brake to trigger penalty braking.

4. The braking control method according to claim 3, characterized in that, After the locomotive's brakes trigger the penalty braking, the system also includes: detecting the pressure of the train pipe; if the pressure of the train pipe is less than the set pressure of 60 kPa, then emergency braking is not initiated.

5. The braking control method according to claim 4, characterized in that, When the pressure in the train pipe is greater than or equal to the constant pressure of 60 kPa, record the train pipe pressure P1 and the detection time t1 at this time. The train pipe pressure P2 is detected after t1+n seconds; When P1-P2≥30kPa, the train's brakes will be activated for emergency braking, and a fault will be indicated.

6. The braking control method according to claim 4 or 5, characterized in that, When the train's brakes do not guide to emergency braking or after emergency braking is performed, the train's speed is detected. When the train speed is zero, the penalty braking of the train brakes is canceled.

7. The braking control method according to claim 6, characterized in that, If the train's brakes fail to guide emergency braking or after emergency braking, and the train speed is not zero, a fault-free reset will be performed and the fault cleared if the following conditions exist: the train pipe pressure is >450kPa when the train is in operation, or when it is a single machine or a supplementary machine.

8. The braking control method according to claim 6, characterized in that, The train's brakes are controlled to apply emergency braking, reducing the pressure in the train pipe by 130 kPa.

9. The braking control method according to claim 7, characterized in that, The BCU filters the acquired local / complementary state pressure switch signal, and the time N seconds is greater than the BCU's filtering time for the local / complementary state pressure switch signal.

10. The braking control method according to claim 1, characterized in that, If the output level of the local / compensation status pressure switch is detected to be low within N seconds after the brake control unit (BCU) is powered on and starts, and if the output level of the local / compensation status pressure switch is detected to be high after N seconds after the BCU is powered on and starts, and the locomotive speed is zero, then it is determined that the local / compensation status pressure switch has malfunctioned; the output level of the local / compensation status pressure switch within N seconds after power-on and N seconds after starting is re-detected.

Images