Full balance hoist type ship lift emergency brake hard connection redundancy control system and method

Abstract

This invention provides a hard-wired redundant control system and method for emergency braking of a fully balanced winch-type ship lift. It includes an emergency stop hard-wired direct control circuit connected in parallel with the original ship lift's PLC program control circuit; a graded braking hardware delay module electrically connected to the emergency stop hard-wired direct control circuit; and an end-of-line forced braking protection circuit interlocked with the emergency stop hard-wired direct control circuit. Together, these components construct a three-level safety redundancy architecture of "PLC program control + hard-wired direct control + power-off forced braking." This addresses the problem that the emergency braking function of existing ship lifts relies entirely on the normal operation of the PLC hardware and software, lacking a hardware-level control circuit independent of the PLC. This invention belongs to the field of ship lift control technology for water conservancy and navigation engineering.

Description

Technical Field

[0001] This invention belongs to the field of control technology for ship lifts in water conservancy and navigation engineering, specifically involving the braking safety redundancy control technology for heavy-duty lifting equipment with large inertia, and particularly a hard-connected redundant control system and method for emergency braking of a fully balanced winch-type ship lift. Background Technology

[0002] The Wujiang River is the largest tributary on the south bank of the upper reaches of the Yangtze River and a vital waterway connecting Guizhou to the sea. The Shatuo Ship Lift, a key navigation facility in the cascade development of the Wujiang River, is a crucial node for Guizhou's northward entry into the Yangtze River. Its safe and stable operation directly impacts the navigation efficiency and safety of the Wujiang River basin. The Shatuo Ship Lift is a fully balanced wire rope winch type, with a maximum lifting height of 75.38m. The effective dimensions of the ship-carrying chamber are 58.0m × 12.0m × 2.5m, and the effective water area dimensions are also 58.0m × 12.0m × 2.5m (length × width × water depth). The total weight of the chamber structure, equipment, and water is approximately 3300t. The ship-carrying chamber is a high-inertia, heavy-load operating device. The braking system is the core component ensuring normal stopping of the chamber and safe braking in emergency situations; its performance and reliability directly determine the minimum operational safety of the ship lift. The "Design Code for Ship Lifts" (GB51177-2016) clearly requires that the safety braking system should have the core principles of redundant design and fail-safe design.

[0003] In existing technologies, the braking systems of the Shatuo ship lift and similar domestically produced fully balanced winch-type ship lifts generally adopt a normally closed hydraulic braking structure. Emergency braking commands are processed by the PLC program logic in the main engine room before being sent to the brake pump station to activate the brakes. While this design meets operational requirements under normal conditions, it has the following core safety defects:

[0004] 1. PLC failure prevents emergency braking commands from being issued: All emergency stop buttons, motor overspeed protection, and limit position protection signals at the entire site must first be connected to the main control room PLC for program logic judgment before outputting braking commands. If both PLCs in the main control room simultaneously experience malfunctions such as freezing, crashing, power failure, or hardware damage, they will be unable to output the brake activation signal, the brake will fail to perform the braking action, and the ship's carriage will completely lose braking protection, posing a significant risk of carriage slippage, equipment damage, and even personal injury.

[0005] 2. Brake pump station PLC malfunction causing brake command failure: Even if the main control room PLC outputs brake signals normally, if the local PLC of the brake pump station experiences communication failure, program abnormality, or hardware damage, it will be unable to receive and execute the brake activation command, resulting in the brake refusing to operate. The existing system does not have a direct braking channel bypassing the pump station PLC, creating a single point of failure bottleneck in the control link.

[0006] In summary, the implementation of the emergency braking function of existing ship lifts relies entirely on the normal operation of PLC hardware and software, lacking a hardware-level control loop independent of the PLC, which does not conform to the design principle of "fail-safe" for special equipment. Summary of the Invention

[0007] The present invention aims to provide a hard-connected redundant control system and method for emergency braking of a fully balanced winch-type ship lift, in order to solve the problem that the implementation of the emergency braking function of existing ship lifts completely depends on the normal operation of PLC hardware and software, lacks a hardware-level control loop independent of PLC, and does not meet the design principle of "fail-oriented safety" for special equipment.

[0008] To solve the above-mentioned technical problems, the present invention provides an emergency braking hard-connection redundant control system for a fully balanced winch-type ship lift, comprising:

[0009] An emergency stop hard-wired direct control circuit is set in parallel with the original ship lift PLC program control circuit;

[0010] A graded braking hardware delay module electrically connected to the emergency stop hard-wired direct control circuit;

[0011] The end-forced braking protection circuit is interlocked with the emergency stop hard-wired direct control circuit;

[0012] Together, we will construct a three-level safety redundancy architecture consisting of "PLC program control + hard-wiring direct control + power failure forced braking";

[0013] in:

[0014] The emergency stop hard-wired direct control circuit includes a series unit for emergency stop signals across the entire line. This unit consists of emergency stop buttons, motor overspeed switches, and limit position protection contacts at each station of the ship lift connected in series via hard wiring. It is designed to ensure that the entire circuit responds immediately when triggered at any point, thus completely solving the problem that the original signal had to be relayed through the PLC.

[0015] The graded braking hardware delay module includes multiple delay relays. Its input terminal is connected to the emergency stop hard-wired direct control circuit, and its output contact is connected in parallel with the original PLC braking output contact. It is also directly connected to the brake control valve group circuit corresponding to the brake pump station and the brake pump station control valve group drive circuit, which is used to drive the brakes at each stage according to a preset timing sequence.

[0016] The end-of-line forced braking protection circuit includes a forced braking button and an interlocking control unit. The forced braking button is connected to the main control room cabinet via hard wiring. The input terminal of the interlocking control unit is electrically connected to the normally closed contact of the emergency stop hard-wired direct control circuit, which is used to cut off the power supply to the pump station CPU when the brake pump station control fails, thereby achieving forced braking due to pressure loss.

[0017] In the aforementioned control system, the graded braking hardware delay module includes three industrial-grade high-precision delay relays, specifically:

[0018] The first time-delay relay has a delay setting of 0.05 to 0.2 seconds.

[0019] The second time-delay relay has a delay setting of 2 to 6 seconds.

[0020] The third time-delay relay has a delay setting of 6 to 12 seconds.

[0021] These correspond to the control of the lifting brake, safety brake, and working brake, respectively.

[0022] Furthermore, the graded braking hardware delay module includes:

[0023] The first time delay relay has a delay setting of 100ms. Its output contact is connected to the control valve group circuit of the lifting brake and corresponds to the lifting brake's brake-on command.

[0024] The second time delay relay has a delay setting of 4 seconds. Its output contact corresponds to the control valve group circuit of the safety brake and corresponds to the safety brake activation command.

[0025] The third time-delay relay has a delay setting of 8 seconds. Its output contact is connected to the control valve group circuit of the working brake and corresponds to the working brake's braking command.

[0026] When the emergency stop hard-wired direct control circuit is triggered, the three time-delay relays act sequentially according to the set timing sequence, directly driving the control valve group to release pressure and realize the brake's staged engagement, without the need for the PLC in the main control room; under normal operating conditions, the time-delay relay coils are de-energized and the contacts are in the open state, which does not affect the normal control of the original PLC circuit.

[0027] In the aforementioned control system, the coverage sites of the emergency stop signal series unit for the entire line include the control station in the ship lift central control room, the local control station in the main engine room, the local control station in the transmission, and the terminal boxes on the left and right decks of the ship-carrying chamber. The emergency stop hard-wired direct control circuit adopts AC220V safety control voltage, and the cable is selected as ZR-DJYPVP-2×1.5mm² flame-retardant twisted pair double shielded cable, which is laid in galvanized steel pipe throughout to avoid strong electromagnetic interference on site.

[0028] In the aforementioned control system, all contacts of the emergency stop hard-wired direct control circuit are made of gold-plated industrial-grade components, and the circuit current design margin is ≥3 times the rated value; surge protection devices are installed at both ends of the circuit; each braking control branch is equipped with an independent RT18 type fuse protection with a rated fusing current of 2A; the wiring terminals are double-screw crimped industrial-grade terminals.

[0029] In the aforementioned control system, the forced braking button is a mushroom-shaped self-locking button with a mechanical lock and a transparent protective cover, which is located on the control panel in the central control room; the connecting cable between the forced braking button and the main control room control cabinet is a ZR-KVV-4×2.5mm² control cable.

[0030] In the aforementioned control system, the control logic of the interlocking control unit is as follows: when the emergency stop hard-wired direct control circuit is not triggered, the forced braking protection circuit is in a locked state, and triggering the forced braking button only executes the normal shutdown procedure of the ship lift, without cutting off the power supply to the brake pump station CPU; when the emergency stop hard-wired direct control circuit is triggered, the forced braking button is triggered, and the working power supply of the brake pump station CPU unit is immediately cut off through the safety relay.

[0031] In the aforementioned control system, the power status of the brake pump station CPU and the trigger status of the forced braking button are both connected to the original ship lift PLC system and displayed in real time through the host computer in the central control room. The action signals are also connected to the ship lift event recording system to achieve full traceability.

[0032] In the aforementioned control system, the emergency stop hard-wired direct control circuit and the end forced braking protection circuit are in a passive standby state under normal operating conditions of the ship lift, without changing the original ship lift's normal lifting, stopping braking, status monitoring functions and operating procedures.

[0033] This invention also provides a redundant control method for emergency braking of a fully balanced winch-type ship lift, comprising the following steps:

[0034] S1. Normal operating condition braking control: The normal lifting and lowering of the ship carrying chamber, parking braking and conventional emergency operating condition braking control are completed through the original ship lift PLC program control circuit. The emergency stop hard-wired direct control circuit and the end forced braking protection circuit are in a passive standby state and do not interfere with the operation of the original system.

[0035] S2, Emergency braking mode with main computer room PLC out of control and brake pump station PLC normal: When the main computer room PLC crashes, loses power, or has a program fault, and the brake pump station PLC is normal, the emergency stop button, motor overspeed protection contact, or limit position protection contact at any station is triggered, the emergency stop hard-wired direct control circuit is immediately connected, the staged braking hardware delay module acts in sequence according to the preset timing, and the local PLC of the brake pump station directly drives the brake pump station valve group to release pressure through the brake pump station valve group drive circuit to complete the staged braking;

[0036] S3. Forced braking control under pump station control failure: When the emergency stop hard-wired direct control circuit is triggered, the PLC of the brake pump station fails and the brake does not engage as required. When the operator presses the forced braking button in the central control room, the working power of the brake pump station CPU unit is directly cut off through the end forced braking protection circuit. All solenoid valves of the pump station lose power, the hydraulic circuit is fully depressurized, and all brakes rely on the disc spring force to complete the braking action, thus achieving the final safety guarantee.

[0037] S4. Interlocking protection control: When the emergency stop hard-wired direct control circuit is not triggered, the end forced braking protection circuit is in a locked state. Triggering the forced braking button will only execute the normal shutdown procedure of the ship lift and will not cut off the power supply to the brake pump station CPU to avoid misoperation.

[0038] The present invention has the following advantages:

[0039] 1. Significantly Enhanced Safety: A three-level safety redundancy architecture has been constructed, completely eliminating the original system's sole reliance on the PLC. Even if all PLCs in the entire ship lift system fail, graded emergency braking can be completed through hard-wired circuits; even if the brake pump station control unit completely fails, forced braking can achieve pressure loss braking, fundamentally eliminating the major safety risk of brake failure and fully meeting the mandatory requirements of the "Ship Lift Design Code".

[0040] 2. Significantly Enhanced Reliability: The hard-wired circuit adopts pure hardware logic, eliminating the risks of software-related crashes, program malfunctions, and communication interruptions. The circuit uses industrial-grade high-reliability components, with a mean time between failures (MTBF) ≥ 100,000 hours, far exceeding that of PLC control systems. The redundant design of the dual-circuit parallel connection reduces the probability of emergency braking function failure by two orders of magnitude.

[0041] 3. Shock-free and smooth braking: The graded braking sequence is completely consistent with the original PLC control through hardware time delay relays, with an action timing error of ≤50ms. This avoids the rigid impact of emergency braking on the ship carriage and lifting mechanism, and ensures the service life of the equipment.

[0042] 4. Strong compatibility and scalability: The new circuit is designed to be connected in parallel with the original PLC control circuit. Under normal working conditions, it is in a passive standby state, without changing all functions of the original system such as normal lifting, parking braking, and status monitoring. It does not change the routine operating procedures of the operators. The modification can be completed during the downtime window without affecting normal navigation. It can be directly replicated and promoted to the safety upgrade of braking systems of similar ship lifts and heavy-duty cranes with large inertia in China.

[0043] 5. Excellent maintainability and prevention of misoperation: The hard-wired circuit structure is clear and relatively independent from the original PLC system, making it easy to locate fault points. Maintenance personnel can quickly complete circuit testing and fault handling using conventional tools such as multimeters. The forced braking circuit is equipped with double interlock protection, which only takes effect after the emergency stop circuit is triggered, fundamentally avoiding unplanned shutdowns caused by misoperation, thus balancing safety and operational stability. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of a three-level security redundancy architecture;

[0045] Figure 2 This is the wiring diagram of the emergency stop mechanism brake staged activation control circuit.

[0046] Figure 3 This is the wiring diagram for the principle of motor overspeed;

[0047] Figure 4 This is the wiring diagram for the emergency stop button in the central control room;

[0048] Figure 5 This is the wiring diagram for the emergency stop signal to the time delay relay (after the emergency stop button is pressed in the main computer room, three time delay relays are connected in parallel for output).

[0049] Figure 6 This is the schematic diagram of the wiring to send commands to the braking station;

[0050] Figure 7 and Figure 8 This is the wiring diagram for the forced braking principle in the central control room;

[0051] Figure 9 This is the wiring diagram for the safety relay connected to the PLC power supply circuit of the brake pump station. Detailed Implementation

[0052] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0053] In the following description, certain specific details are set forth for the purpose of illustrating various disclosed embodiments in order to provide a thorough understanding of the various disclosed embodiments. However, those skilled in the art will recognize that embodiments may be practiced without one or more of these specific details. In other instances, well-known apparatuses, structures, and techniques associated with this application may not have been shown or described in detail to avoid unnecessarily obscuring the description of the embodiments.

[0054] Throughout this specification, references to "an embodiment" or "an embodiment" indicate that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Therefore, the appearance of "in an embodiment" or "an embodiment" in various places throughout the specification does not necessarily refer to the same embodiment. Furthermore, a particular feature, structure, or characteristic may be combined in any manner in one or more embodiments.

[0055] In the following description, in order to clearly demonstrate the structure and working method of the present invention, a number of directional terms will be used. However, terms such as "front", "back", "left", "right", "outside", "inside", "outward", "inward", "up", and "down" should be understood as convenient terms and not as limiting terms.

[0056] See Figures 1 to 9 This embodiment provides an emergency braking hard-connection redundant control system for a fully balanced winch-type ship lift. This embodiment is applied to the Wujiang Shatuo ship lift in Guizhou Province. The system is an optimization and improvement based on the original Wujiang Shatuo ship lift system. The specific improvement measures are as follows:

[0057] a. An emergency stop hard-wired direct control circuit is set in parallel with the original ship lift PLC program control circuit. The emergency stop hard-wired direct control circuit includes a series unit of emergency stop signals for the entire line. The series unit of emergency stop signals for the entire line is formed by connecting the emergency stop buttons, motor overspeed protection contacts and limit position protection contacts of each station of the ship lift through hard wiring. It is used to ensure that the entire circuit responds immediately when triggered at any point, completely solving the problem that the original signal had to be transferred through the PLC.

[0058] b. A graded braking hardware delay module electrically connected to the emergency stop hard-wired direct control circuit, the graded braking hardware delay module including multiple delay relays, the input terminal of which is connected to the emergency stop hard-wired direct control circuit, the output contact is connected in parallel with the original PLC braking output contact, and is directly connected to the brake control valve group circuit corresponding to the brake pump station, for driving the brakes of each stage to operate according to a preset timing sequence.

[0059] c. An end-of-line forced braking protection circuit interlocked with the emergency stop hard-wired direct control circuit, the end-of-line forced braking protection circuit including a forced braking button and an interlocking control unit, the forced braking button being connected to the main control room control cabinet via hard wiring, the input terminal of the interlocking control unit being electrically connected to the normally closed contact of the emergency stop hard-wired direct control circuit, used to cut off the power supply to the pump station CPU and realize pressure loss forced braking when the brake pump station control fails.

[0060] This ship lift is a fully balanced wire rope winch type, with a maximum lifting height of 75.38m. The effective water area dimensions of the ship chamber are 58.0m × 12.0m × 2.5m (length × width × water depth). The total weight of the ship chamber structure, equipment, and water inside the chamber is approximately 3300t. Its original braking system was a normally closed hydraulic braking system, equipped with 4 SHD5-2 type working brakes, 40 SH32-01 type lifting brakes, and 56 SH32-01 type safety brakes, and matched with ST210-100P type brake hydraulic station. The original system adopted dual PLC redundant control in the main engine room, and emergency braking relied entirely on PLC program logic.

[0061] The specific principle is as follows:

[0062] Figure 1 The diagram illustrates the three-level loop and working principle of the improved system in this embodiment.

[0063] Figure 2 In the diagram, the limit switch on the left is an external sensor. Two limit switches are installed diagonally at the highest point and two diagonally at the lowest point of the ship lift body to prevent the ship lift from overshooting or sinking. Normally, the sensor's normally closed output wiring opens upon triggering. This is an essential external safety device for all ship lifts.

[0064] Figure 3 Instructions for motor overspeed switch:

[0065] 1. A motor overspeed switch is a device used to monitor and protect motor speed. Its main functions include speed monitoring, overspeed protection, alarm, or shutdown. When the speed exceeds a set value, it can prevent equipment damage or accidents by cutting off the power supply or issuing an alarm. In the schematic diagram, a normally closed function is used; it immediately disconnects when the speed exceeds the set value. (The four dashed boxes in the diagram represent this.)

[0066] 2. 4KB36, 4KB37, 4KB38, and 4KB39 represent intermediate relays, and terminals 13 and 14 are the relay coils. Regarding relays: Relays have common terminals, normally open terminals, and normally closed terminals. First row (normally closed terminals): 1, 2, 3, 4; Second row (normally open terminals): 5, 6, 7, 8; Third row (common terminals): 9, 10, 11, 12; Fourth row: 13, 14. Among them, 1, 5, and 9 form one group, with 1 and 9 being normally closed terminals and 5 and 9 being normally open terminals. Similarly: 2, 6, and 10 form one group; 3, 7, and 11 form another group; and 4, 8, and 12 form a third group.

[0067] In the diagram, 4KB36, 4KB37, 4KB38, and 4KB39 use relays 7 and 11, which are normally open terminals. However, because the motor overspeed switch is in the closed state, segments 13 and 14 of 4KB36, 4KB37, 4KB38, and 4KB39 are energized, thus energizing relays 7 and 11 in 4KB36, 4KB37, 4KB38, and 4KB39, which are in the closed state.

[0068] Figure 4 In this context, the emergency stop button is the brake pump station's own "mushroom-head" emergency stop button, located on the brake's hydraulic pump station. It has normally closed and normally open terminals, but the industry generally uses the normally closed terminal. It's used to control the brake pump station's emergency stop via PLC control. Other stations, such as the ship's compartment, transmission station, and engine room, also have "emergency stop mushroom-head switches" (SB). SB is a button identifier, such as... Figure 2 2SB5, 2SB12.

[0069] The "limit position + motor overspeed switch + pump station mushroom head switch + central control room mushroom head switch + ship chamber mushroom head switch + transmission mushroom head switch + main engine room mushroom head switch" all trigger the brake pump station PLC through the output of the main engine room PLC, thereby realizing the emergency shutdown of the brake pump station.

[0070] Level 1: PLC program control loop, i.e., the original system loop.

[0071] Level 2: Hard-wired direct control circuit (condition when the PLC in the main control room fails)

[0072] like Figure 5 As shown, after the emergency stop button is pressed in the main control room, 2KBO is activated, and KT1, KT2, and KT3, which are time-delay relays, are activated respectively. Figure 6 The 2KO18, 2KO26, and 2KO22 pumps are connected in parallel to trigger the PLC of the brake pump station, enabling the emergency shutdown of the brake pump station.

[0073] Level 3: Power failure forced braking (condition where both the main control room PLC and the brake pump station PLC fail simultaneously).

[0074] like Figures 7 to 9 As shown, after pressing the emergency brake button in the main control room, the brake pump station PLC has no effect. Then, pressing the forced brake button (2SB10) in the central control room energizes the 2KB3 relay (as shown in the right figure), causing the safety relay KS to become normally open (KS is a safety relay; terminals 1 and 9, and terminals 2 and 10 are connected to the brake pump station PLC power supply circuit). This disconnects terminals 1 and 9 of KS, thus breaking the power supply to the brake pump station PLC and causing the pump station to lose pressure and activate the brake.

[0075] System Implementation Steps

[0076] 1. Design and Preparation Phase

[0077] Complete circuit diagram design, component selection and procurement, organize expert review of design schemes, prepare specialized construction plans and safety technical briefings, and provide specialized training and assessment for construction personnel. The core component selection is as follows:

[0078] ① Delay Relays: Three industrial-grade high-precision time relays are selected as the hardware delay module for graded braking. The operating voltage is AC220V, the delay accuracy is ≤10ms, and the contact capacity is ≥5A. The specific settings are as follows:

[0079] The first time delay relay has a delay setting of 100ms. Its output contact is connected to the control valve group circuit of the lifting brake and corresponds to the lifting brake's brake-on command.

[0080] The second time delay relay has a delay setting of 4 seconds. Its output contact corresponds to the control valve group circuit of the safety brake and corresponds to the safety brake activation command.

[0081] The third time-delay relay has a delay setting of 8 seconds. Its output contact is connected to the control valve group circuit of the working brake and corresponds to the working brake's braking command.

[0082] When the emergency stop hard-wired direct control circuit is triggered, the three time-delay relays act sequentially according to the set timing sequence, directly driving the control valve group to release pressure and realize the brake's staged engagement, without the need for PLC intervention throughout the process; under normal operating conditions, the time-delay relay coils are de-energized and the contacts are in the open state, without affecting the normal control of the original PLC circuit.

[0083] ② Emergency stop button and forced braking button: Select mushroom-shaped self-locking buttons with IP65 protection rating; the forced braking button is equipped with a mechanical lock and a transparent protective cover.

[0084] ③ Cables: The emergency stop circuit uses ZR-DJYPVP-2×1.5mm² flame-retardant twisted pair double shielded cable, and the forced braking circuit uses ZR-KVV-4×2.5mm² control cable;

[0085] ④ Auxiliary components: RT18-32 type fuse (2A), Weidmüller double screw terminal block, and industrial-grade surge protector are selected.

[0086] 2. Hardware installation and wiring construction

[0087] The entire process was completed during the ship lift's downtime window, with power outages and lockouts implemented as safety measures. Specific construction details are as follows:

[0088] ① Lay the emergency stop hard-wired circuit cable for the entire line, and connect the emergency stop buttons, motor overspeed protection normally closed contacts, and limit position protection normally closed contacts in series in the central control room, main engine room, transmission site, and left and right decks of the ship's compartment into a complete circuit, and connect both ends to the main engine room control cabinet.

[0089] ② Install three time delay relays in the main control room cabinet, complete the parallel connection between the time delay relays and the original PLC brake DO output contacts, and directly connect them to the control valve group circuit of the brake pump station lifting, safety, and working brakes;

[0090] ③ Install the forced braking button on the control panel in the central control room, lay hard-wired cables to the main control room control cabinet, and complete the wiring with the normally closed contact of the emergency stop hard circuit and the shunt trip coil of the main power circuit breaker of the brake pump station CPU.

[0091] ④ Complete the labeling of all circuits, and perform a visual inspection after the wiring is completed to ensure that there are no loose or incorrect connections.

[0092] 3. Static Testing

[0093] Complete the circuit insulation resistance test. The test result shows that the insulation value is ≥20MΩ, which meets the specification requirements. Then, complete the circuit continuity test, interlocking logic test, and time delay relay operation timing calibration in sequence to ensure that the circuit wiring is correct, the logic is error-free, and there are no short circuits, loose connections, or other problems. The error between the time delay relay operation timing and the design value is ≤50ms.

[0094] 4. Dynamic debugging and on-site verification

[0095] Restore system power and complete the following full-condition verification in sequence:

[0096] ① PLC power failure / shutdown verification: Disconnect the power supply of the dual PLCs in the main room, press the emergency stop button, the hard-wired circuit is triggered immediately, the three brakes are engaged in sequence at 100ms, 4s, and 8s, and all brakes are engaged accurately with a timing error of ≤50ms.

[0097] ② Brake pump station PLC fault condition verification: Simulate a brake pump station PLC fault, trigger an emergency stop, press the forced braking button, the brake pump station CPU power is immediately cut off, all solenoid valves lose power, and all brakes are engaged within 2 seconds.

[0098] ③ Compatibility verification: After completing 100 full-stroke lifting and lowering cycles of the ship lift and normal parking braking test, all functions of the original system were normal, the control accuracy and response speed remained unchanged, and there were no false triggers or signal interference in the hard-wired circuits.

[0099] ④ Interlocking protection verification: When the emergency stop is not triggered, pressing the forced braking button will only execute the normal stop procedure and will not cut off the power supply to the pump station CPU; after the emergency stop is triggered, pressing the forced braking button will immediately cut off the power supply to the pump station and trigger the braking. The interlocking logic fully meets the design requirements.

[0100] The specific execution flow of the redundancy control method for emergency braking of the ship lift in this embodiment is as follows:

[0101] S1. Normal operating mode: When the ship lift is lifting, stopping and braking normally, the braking command is executed only through the original PLC program control circuit. The time delay relay coil of the hard-wired circuit is de-energized and the contacts are open. The forced braking circuit is in a locked state. The new circuit does not interfere with the operation of the original system at all.

[0102] When an emergency stop is triggered under normal operating conditions, the original PLC program control circuit and the hard-wired direct control circuit are triggered simultaneously, and the two parallel output braking commands are used to complete the graded braking according to the preset timing sequence, further improving braking reliability.

[0103] S2, Emergency braking mode with PLC failure in main control room and PLC normal operation in brake pump station: When the PLC in main control room crashes, loses power, or has a program fault, and the PLC in brake pump station is normal, the emergency stop button is triggered, the hard-wired direct control circuit is immediately connected, and the three time delay relays act in sequence at 100ms, 4s, and 8s. The local PLC of brake pump station directly drives the brake pump station valve group to release pressure through the brake pump station valve group drive circuit to complete the staged braking.

[0104] S3, Extreme Working Condition Forced Braking Mode (Main Room PLC Failure, Brake Pump Station PLC Failure): After emergency stop is triggered, if the brake pump station PLC fails and the brake fails to engage, the operator presses the forced braking button in the central control room, directly cutting off the main power supply of the brake pump station CPU unit. All solenoid valves lose power, the hydraulic circuit is fully depressurized, and the brake relies on the disc spring force to engage, achieving the final safety guarantee.

[0105] S4. Interlocking protection control: When the emergency stop hard-wired direct control circuit is not triggered, the end forced braking protection circuit is in a locked state. Triggering the forced braking button will only execute the normal shutdown procedure of the ship lift and will not cut off the power supply to the brake pump station CPU to avoid misoperation.

[0106] After the renovation, the Shatuo ship lift has been operating continuously and stably. During the renovation, it triggered emergency shutdown tests multiple times. The hard-wired circuit operated accurately and in the correct timing, without any failure to operate or malfunction. This completely eliminated the major safety hazards of the original braking system and greatly improved the safety and reliability of the ship lift.

[0107] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A fully balanced winch-type ship lift emergency braking hard-connection redundant control system, including: An emergency stop hard-wired direct control circuit is set in parallel with the original ship lift PLC program control circuit; A graded braking hardware delay module electrically connected to the emergency stop hard-wired direct control circuit; The end-forced braking protection circuit is interlocked with the emergency stop hard-wired direct control circuit; Together, we will construct a three-level safety redundancy architecture consisting of "PLC program control + hard-wiring direct control + power failure forced braking"; in: The emergency stop hard-wired direct control circuit includes a series unit for emergency stop signals across the entire line. This unit consists of emergency stop buttons, motor overspeed switches, and limit position protection contacts at each station of the ship lift connected in series via hard wiring. It is designed to ensure that the entire circuit responds immediately when triggered at any point, thus completely solving the problem that the original signal had to be relayed through the PLC. The graded braking hardware delay module includes multiple delay relays. Its input terminal is connected to the emergency stop hard-wired direct control circuit, and its output contact is connected in parallel with the original PLC braking output contact. It is also directly connected to the brake control valve group circuit corresponding to the brake pump station and the brake pump station control valve group drive circuit, which is used to drive the brakes at each stage according to a preset timing sequence. The end-of-line forced braking protection circuit includes a forced braking button and an interlocking control unit. The forced braking button is connected to the main control room cabinet via hard wiring. The input terminal of the interlocking control unit is electrically connected to the normally closed contact of the emergency stop hard-wired direct control circuit, which is used to cut off the power supply to the pump station CPU when the brake pump station control fails, thereby achieving forced braking due to pressure loss.

2. The control system according to claim 1, characterized in that, The graded braking hardware delay module includes three industrial-grade high-precision delay relays, specifically: The first time-delay relay has a delay setting of 0.05 to 0.2 seconds. The second time-delay relay has a delay setting of 2 to 6 seconds. The third time-delay relay has a delay setting of 6 to 12 seconds. These correspond to the control of the lifting brake, safety brake, and working brake, respectively.

3. The control system according to claim 2, characterized in that, The graded braking hardware delay module includes: The first time delay relay has a delay setting of 100ms. Its output contact is connected to the control valve group circuit of the lifting brake and corresponds to the lifting brake's brake-on command. The second time delay relay has a delay setting of 4 seconds. Its output contact corresponds to the control valve group circuit of the safety brake and corresponds to the safety brake activation command. The third time delay relay has a delay setting of 8s. Its output contact corresponds to the control valve group circuit of the working brake and corresponds to the working brake braking command. When the emergency stop hard-wired direct control circuit is triggered, the three time-delay relays act sequentially according to the set timing sequence, directly driving the control valve group to release pressure and realize the brake's staged engagement, without the need for the PLC in the main control room; under normal operating conditions, the time-delay relay coils are de-energized and the contacts are in the open state, which does not affect the normal control of the original PLC circuit.

4. The control system according to claim 1, characterized in that: The coverage sites of the emergency stop signal series unit for the entire line include the control station in the ship lift central control room, the local control station in the main engine room, the local control station in the transmission, and the terminal boxes on the left and right decks of the ship carrying compartment. The emergency stop hard-wired direct control circuit adopts AC220V safe control voltage, and the cable is selected as ZR-DJYPVP-2×1.5mm² flame-retardant twisted pair double shielded cable, which is laid in galvanized steel pipe throughout to avoid strong electromagnetic interference on site.

5. The control system according to claim 1, characterized in that: All contacts of the emergency stop hard-wired direct control circuit are made of gold-plated industrial-grade components, and the circuit current design margin is ≥3 times the rated value; surge protection devices are set at both ends of the circuit; each braking control branch is equipped with an independent RT18 type fuse protection with a rated fusing current of 2A; the wiring terminals are double screw crimping industrial-grade terminals.

6. The control system according to claim 1, characterized in that: The forced braking button is a mushroom-shaped self-locking button with a mechanical lock and a transparent protective cover, and is located on the control panel in the central control room; the connecting cable between the forced braking button and the main control room control cabinet is a ZR-KVV-4×2.5mm² control cable.

7. The control system according to claim 1, characterized in that, The control logic of the interlocking control unit is as follows: when the emergency stop hard-wired direct control circuit is not triggered, the forced braking protection circuit is in a locked state. Triggering the forced braking button only executes the normal shutdown procedure of the ship lift and does not cut off the power supply of the brake pump station CPU. When the emergency stop hard-wired direct control circuit is triggered, triggering the forced braking button immediately cuts off the working power supply of the brake pump station CPU unit through the action of the relay.

8. The control system according to claim 1, characterized in that, The power status of the brake pump station CPU and the trigger status of the forced braking button are both connected to the original ship lift PLC system and displayed in real time through the host computer in the central control room. The action signals are also connected to the ship lift event recording system to achieve full traceability. The emergency stop hard-wired direct control circuit and the end forced braking protection circuit are in a passive standby state under normal operating conditions of the ship lift, without changing the original ship lift's normal lifting, stopping braking, status monitoring functions and operating procedures.

9. A redundant control method for emergency braking of a fully balanced winch-type ship lift, characterized in that: This method, implemented based on the system described in any one of claims 1-8, includes the following steps: S1. Normal operating condition braking control: The normal lifting and lowering of the ship carrying chamber, parking braking and conventional emergency operating condition braking control are completed through the original ship lift PLC program control circuit. The emergency stop hard-wired direct control circuit and the end forced braking protection circuit are in a passive standby state and do not interfere with the operation of the original system. S2, Emergency braking mode with main computer room PLC out of control and brake pump station PLC normal: When the main computer room PLC crashes, loses power, or has a program fault, and the brake pump station PLC is normal, the emergency stop button, motor overspeed protection contact, or limit position protection contact at any station is triggered, the emergency stop hard-wired direct control circuit is immediately connected, the staged braking hardware delay module acts in sequence according to the preset timing, and the local PLC of the brake pump station directly drives the brake pump station valve group to release pressure through the brake pump station valve group drive circuit to complete the staged braking; S3. Forced braking control under pump station control failure: When the emergency stop hard-wired direct control circuit is triggered, the PLC of the brake pump station fails and the brake does not engage as required. When the operator presses the forced braking button in the central control room, the working power of the brake pump station CPU unit is directly cut off through the end forced braking protection circuit. All solenoid valves of the pump station lose power, the hydraulic circuit is fully depressurized, and all brakes rely on the disc spring force to complete the braking action, thus achieving the final safety guarantee. S4. Interlocking protection control: When the emergency stop hard-wired direct control circuit is not triggered, the end forced braking protection circuit is in a locked state. Triggering the forced braking button will only execute the normal shutdown procedure of the ship lift and will not cut off the power supply to the brake pump station CPU to avoid misoperation.

Images