Method for realizing safety control of tower crane and control system

Abstract

The embodiment of the invention provides a method for realizing safety control of a tower crane and a control system, and the method comprises the following steps: a tower crane controller accumulates and counts synchronous counting variables by taking a first time length as a period, and sends the synchronous counting variables to an on-tower control unit; and when the synchronous counting variables received by the control unit system are all kept unchanged within a second duration, the control unit resets the output of each DO module on the tower crane, and the second duration comprises a plurality of first durations. The technical scheme of the embodiment of the invention is used for detecting the communication state of the tower crane controller and the control unit and the operation state of the tower crane controller, and resetting the output of each DO module of the control unit when the tower crane controller is abnormal or the communication is abnormal, so that the potential safety hazard of the unmanned tower crane control system is reduced or even eliminated to the greatest extent; and the safety of field equipment and personnel is ensured.

Description

Technical Field

[0001] The present invention relates to the field of safe production, and particularly to a method and a control system for realizing safety control of a tower crane. Background Art

[0002] Figure 1 The control system of the current unmanned tower crane is shown, which consists of two parts: a ground system and an aerial system. The ground system mainly consists of a ground linkage console, a ground remote IO module, a ground network switch, a wireless hand-held remote controller, etc., and the modules communicate with each other. The aerial system mainly consists of an aerial edge controller or a PLC controller, an aerial remote IO module, an aerial network switch, etc., and the modules also communicate with each other.

[0003] The operator remotely operates the gears and button signals of the "wireless hand-held remote controller" or the "ground linkage console" on the ground and inputs them to the ground remote IO. The ground remote IO transmits the signals to the aerial PLC or edge controller through optical fibers. After the controller collects the signals, it executes the program algorithm and outputs the results to the aerial remote IO. The aerial IO controls the start and stop of the frequency converter and the given gear speed, and finally drives and controls the motor to complete the motion control of the hoisting, luffing, and slewing three axes (three mechanisms).

[0004] The stability of the communication between the module units of the tower crane control system is the premise for the stable operation of the entire system. However, in actual field applications, due to the large electromagnetic interference generated by the frequent start-stop and speed change of high-power electrical components such as frequency converters and motors in the system surrounding environment, plus various complex wiring environments, the modules are separated, and the distance between the ground and the aerial systems is far, etc., it is difficult to ensure the absolute stability and reliability of the system communication. Occasionally, there will always be communication anomalies or interruptions, and this occasional communication anomaly or interruption cannot be completely eliminated. In addition, due to various reasons, the PLC, edge controller, and remote IO RCM cannot absolutely guarantee that they will not crash during operation.

[0005] In the traditional unmanned tower crane control system, when the RCM on the tower crashes or there is an abnormal or interrupted communication with the controller, or when the controller crashes, the remote IO will not be controlled by the controller. At this time, the remote IO will be in an out-of-control state, and the output of the remote IO will remain in the state at the moment before the communication interruption. The operation of the mechanism will also be in an out-of-control and maintained state, resulting in the mechanism always moving at a constant speed and unable to stop. If this occurs during high-speed movement, it will be extremely dangerous, often leading to the risk of hitting objects or people, and sometimes even causing a huge safety accident of the tower crane being damaged and people being killed.

[0006] In view of the above situation, most traditional unmanned tower crane control systems adopt relatively simple algorithms, and perform some failure detection and safety interlock control in the controller program. For example, in the controller algorithm, simple operations and comparison judgments are performed on the states of each remote IO, and whether the remote IO is abnormal is determined according to the operation results. This method can detect and intervene in most abnormal situations. However, due to the diversity of communication abnormal situations and the large number of instability influencing factors caused by module separation, there is also a small probability that the controller will operate abnormally. The combination of various influencing factors often makes it difficult to accurately and reliably detect and effectively intervene in various different abnormal situations. In some abnormal states, the controller cannot detect accurately or misjudges, and in some abnormal situations, the controller cannot detect, so it cannot intervene. In addition, the controller cannot accurately detect the abnormal operation of the remote IO RCM itself. Therefore, there are still loopholes and deficiencies in the traditional safety guarantee scheme, and there are still uncontrollable safety hazards. Summary of the Invention

[0007] In view of this, the embodiments of the present invention provide a method and a control system for realizing safety control of a tower crane. The technical solution of the embodiments of the present invention is used for the safety control of an unmanned tower crane. By detecting the communication state between the tower crane controller and the on-tower control unit and the operating state of the tower crane controller, and resetting the outputs of each DO module of the on-tower control unit when the tower crane controller is abnormal or the communication is abnormal, the safety hazards of the unmanned tower crane control system are minimized or even eliminated, and the safety of on-site equipment and personnel is guaranteed.

[0008] In a first aspect, an embodiment of the present invention provides a method for realizing safety control of a tower crane, including: the tower crane controller accumulatively counts a synchronous counting variable in a first time period and sends the synchronous counting variable to the on-tower control unit; when the synchronous counting variables received by the on-tower control unit remain unchanged within a second time period, the on-tower control unit resets the outputs of its respective DO modules on the tower crane, and the second time period includes several first time periods.

[0009] Therefore, by detecting the communication state between the tower crane controller and the on-tower control unit and the operating state of the tower crane controller, and resetting the outputs of each DO module of the on-tower control unit when the tower crane controller is abnormal or the communication is abnormal, the safety hazards of the unmanned tower crane control system are minimized or even eliminated, and the safety of on-site equipment and personnel is guaranteed.

[0010] In a possible implementation manner of the first aspect, when the on-tower control unit resets the outputs of its respective DO modules, it specifically includes: the on-tower control unit controls the tower crane relay groups of each axis of the tower crane to lose power and resets the output commands of each gear of the tower crane.

[0011] As described above, one way for the on-tower control unit to reset the outputs of its DO modules is that each DO module in the IO module of the on-tower control unit outputs OFF, causing the relay groups controlling each axis of the tower crane to lose power and resetting the output commands for each tower crane gear of the tower crane, so that each axis of the tower crane gradually stops moving.

[0012] In a possible implementation manner of the first aspect, it further includes: the on-tower control unit generates a square wave signal with a third time period and sends it to the safety controller, and the safety controller is independent of the tower crane controller; when the safety controller determines that the on-tower control unit is abnormal according to the square wave signal, it cuts off the control of the on-tower control unit over each axis of the tower crane, and the stability of the safety controller is greater than that of the on-tower control unit.

[0013] As described above, by adding a safety controller to detect the state of the on-tower control unit and cutting off the control of the on-tower control unit over the tower crane relay group when the on-tower control unit is abnormal, and the safety controller is independent of the tower crane controller and does not affect each other, the control safety of the unmanned tower crane is further improved.

[0014] In a possible implementation manner of the first aspect, when the safety controller cuts off the control of the on-tower control unit over each axis of the tower crane, it includes: the safety controller outputs a safety signal through a DO module, and this safety signal cuts off the control of the on-tower control unit over each axis of the tower crane.

[0015] As described above, when the on-tower control unit is abnormal, a newly added relay is controlled by a safety signal to cut off the control of the on-tower control unit over each axis of the tower crane, and each axis of the tower crane returns to the zero gear and gradually stops moving, reducing the potential danger brought by each axis maintaining the moving state before the abnormality.

[0016] In a possible implementation manner of the first aspect, the preset DO module of the on-tower control unit is connected to the input channel of the safety controller through a physical hard wire.

[0017] As described above, the preset DO module of the on-tower control unit is connected to the input channel of the safety controller, so that the square wave signal is independently and safely transmitted to the safety controller.

[0018] In a possible implementation manner of the first aspect, the square wave signal is not controlled by the tower crane controller.

[0019] As described above, since the square wave signal is not controlled by the tower crane controller, the operation state of the on-tower control unit can be independently detected by detecting the square wave signal, so the safety and reliability of the unmanned tower crane are improved.

[0020] In a possible implementation of the first aspect, the process by which the safety controller determines that the on-tower control unit is abnormal based on the square-wave signal includes: the safety controller accumulatively counts the square-wave signal starting from 0 within each fourth time period, and the fourth time period includes several third time periods; when the count is less than or equal to a set value after one fourth time period, it is determined that the on-tower control unit is abnormal, and this set value is less than the quotient of the fourth time period divided by the third time period.

[0021] As described above, according to the count of the independent square wave received by the independent safety controller, when the change value of the count within the set time is less than the set value, it accurately detects that the on-tower control unit fails to correctly output the square-wave signal and its operation is abnormal.

[0022] In a possible implementation of the first aspect, the safety controller uploads the status of the on-tower control unit to the upper computer, and the status value at least includes the number of times the on-tower control unit has an abnormality.

[0023] As described above, the safety controller uploads the occurrence times of the on-tower control unit to the upper computer for analysis on the upper computer to help find the reasons for the abnormalities of the on-tower control unit.

[0024] In the second aspect, an embodiment of the present invention provides a tower crane control system, including: a tower crane controller for accumulatively counting a synchronous counting variable in a first time period as a cycle and sending the synchronous counting variable to the on-tower control unit, and the tower crane controller is connected to the on-tower control unit through a network switch; the on-tower control unit is used for resetting the output of each DO module when it detects that the received synchronous counting variables remain unchanged within a second time period, and the second time period includes several first time periods.

[0025] As described above, by detecting the communication status between the tower crane controller and the on-tower control unit and the operating status of the tower crane controller, and resetting the output of each DO module of the on-tower control unit when the tower crane controller is abnormal or the communication is abnormal, the potential safety hazards of the unmanned tower crane control system can be minimized or even eliminated, ensuring the safety of on-site equipment and personnel.

[0026] In a possible implementation of the second aspect, the on-tower control unit specifically resets the output of each DO module by controlling the tower crane relays of each axis of the tower crane to lose power and resetting the output instructions of each gear of the tower crane.

[0027] As described above, one way for the on-tower control unit to reset the output of each DO module is that each DO module in the IO module of the on-tower control unit outputs OFF, causing the relay groups controlling each axis of the tower crane to lose power and resetting the output instructions of each tower crane gear of the tower crane, so that each axis of the tower crane gradually stops moving.

[0028] In a possible implementation of the second aspect, a safety controller is further included; the on-tower control unit generates a square wave signal with a third time period and sends it to the safety controller. The safety controller is independent of the tower crane controller, and the stability of the safety controller is greater than that of the on-tower control unit; when the safety controller determines that the on-tower control unit is abnormal according to the square wave signal, it cuts off the control of the on-tower control unit over each axis of the tower crane.

[0029] As above, by adding a safety controller to detect the state of the on-tower control unit and cutting off the control of the on-tower control unit over the tower crane relay group when the on-tower control unit is abnormal, and the safety controller is independent of the tower crane controller without affecting each other, the control safety of the unmanned tower crane is further improved.

[0030] In a possible implementation of the second aspect, a safety relay is further included, which is used to cut off the connection between each DO module and the tower crane relay group when the safety controller detects that the on-tower control unit is abnormal.

[0031] As above, it is convenient to control the connection between each DO module of the on-tower control unit and the tower crane relay group through the safety relay.

[0032] In a possible implementation of the second aspect, when the safety controller cuts off the control of the on-tower control unit over each axis of the tower crane, specifically, the safety controller outputs a safety signal through a DO module, and this safety signal cuts off the control of the on-tower control unit over each axis of the tower crane through the safety relay.

[0033] As above, when the on-tower control unit is abnormal, a newly added relay is controlled through a safety signal to cut off the control of the on-tower control unit over each axis of the tower crane, and each axis of the tower crane returns to the zero position and gradually stops moving, reducing the potential danger brought by each axis maintaining the motion state before the abnormality.

[0034] In a possible implementation of the second aspect, the square wave signal is not controlled by the tower crane controller.

[0035] As above, since the square wave signal is not controlled by the tower crane controller, the operation state of the on-tower control unit can be independently detected by detecting the square wave signal, thus improving the safety and reliability of the unmanned tower crane.

[0036] In a possible implementation manner of the second aspect, when the safety controller determines that the on-tower control unit is abnormal according to the square wave signal, specifically, it includes: the safety controller accumulatively counts the square wave signal starting from 0 within each fourth time period, and the fourth time period includes several third time periods; when the count is less than or equal to a set value after one fourth time period, it is determined that the on-tower control unit is abnormal, and the set value is less than the quotient of the fourth time period divided by the third time period.

[0037] As described above, according to the count of the independent square wave received by the independent safety controller, when the change value of the count within the set time is less than the set value, it accurately detects that the on-tower control unit does not correctly output the square wave signal and its operation is abnormal.

[0038] In a possible implementation manner of the second aspect, the safety controller is further configured to upload the state of the on-tower control unit to the host computer, and the state value at least includes the number of times the on-tower control unit has an abnormality.

[0039] As described above, the safety controller uploads the occurrence times of the on-tower control unit to the host computer for analysis on the host computer to help find the reasons for the abnormalities of the on-tower control unit.

[0040] In a possible implementation manner of the second aspect, the preset DO module of the on-tower control unit is physically hard-wired to the DI module of the safety controller.

[0041] As described above, reliable transmission of the square wave signal is achieved through physical hard-wiring. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a schematic structural diagram of the control system of an existing unmanned tower crane;

[0043] Figure 2A It is a schematic flowchart of Embodiment 1 of the method for realizing safety control of a tower crane according to the present invention;

[0044] Figure 2B It is a schematic flowchart of the specific implementation manner of Embodiment 1 of the method for realizing safety control of a tower crane according to the present invention;

[0045] Figure 3 It is a schematic flowchart of the safety control process of the on-tower RCM in Embodiment 2 of the method for realizing safety control of a tower crane according to the present invention;

[0046] Figure 4A It is a schematic flowchart of the specific implementation manner of the safety control of the on-tower RCM in Embodiment 2 of the method for realizing safety control of a tower crane according to the present invention;

[0047] Figure 4BSchematic connection diagram of the tower crane control system according to Embodiment 2 of the method for realizing safety control of a tower crane according to the present invention;

[0048] Figure 5 Schematic structural diagram of Embodiment 1 of a tower crane control system according to the present invention;

[0049] Figure 6 Schematic structural diagram of Embodiment 2 of a tower crane control system according to the present invention. Detailed implementation manners

[0050] In the following description, reference is made to "some embodiments", which describe a subset of all possible embodiments. However, it can be understood that "some embodiments" can be the same subset or different subsets of all possible embodiments, and can be combined with each other without conflict.

[0051] In the following description, the terms "first / second / third, etc." or Module A, Module B, Module C, etc. are only used to distinguish similar objects, or to distinguish different embodiments, and do not represent a specific order for the objects. It can be understood that, where permitted, the specific order or sequence can be interchanged so that the embodiments of the present invention described herein can be implemented in an order other than that illustrated or described herein.

[0052] In the following description, the reference numerals representing steps, such as S110, S120, etc., do not necessarily indicate that these steps will be executed in this order. Where permitted, the order of the front and rear steps can be interchanged, or they can be executed simultaneously.

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used herein are only for the purpose of describing the embodiments of the present invention and are not intended to limit the present invention.

[0054] The embodiments of the present invention provide a method and a control system for realizing safety control of a tower crane. The method includes: the tower crane controller accumulatively counts a synchronous counting variable in a first time period as a cycle, and sends the synchronous counting variable to the on-tower control unit; when the synchronous counting variables received by the on-tower control unit remain unchanged within a second time period, the on-tower control unit resets the outputs of its respective DO modules on the tower crane, and the second time period includes several first time periods.

[0055] The technical solution of the embodiments of the present invention is used to detect the communication status between the tower crane controller and the on-tower control unit and the operating status of the tower crane controller, and reset the outputs of the respective DO modules of the on-tower control unit when the tower crane controller is abnormal or the communication is abnormal, thereby reducing or even eliminating the safety hazards of the unmanned tower crane control system and ensuring the safety of on-site equipment and personnel.

[0056] Among them, the on-tower control unit, hereinafter referred to as the on-tower RCM (Remote Control Module), can be an aerial remote IO module group, which receives control signals from the tower crane control through the control bus and outputs shaft control signals to the tower crane in the form of a DO module.

[0057] The following introduces the embodiments of the present invention with reference to the accompanying drawings.

[0058] First, based on Figures 2A to 2B An embodiment of a method for a tower crane to achieve safety control is introduced.

[0059] Figure 2A The flow of an embodiment of a method for a tower crane to achieve safety control is shown, including steps S110 to S130.

[0060] S110: The tower crane controller accumulatively counts the synchronous counting variable in a first time period and sends the synchronous counting variable to the on-tower RCM.

[0061] Among them, the tower crane controller is a PLC controller or an edge controller. The on-tower RCM is used for communication with the tower crane controller and outputs control commands for the relay groups controlling each axis (each mechanism) of the tower crane and control commands for each gear of the tower crane through its DO module.

[0062] In some embodiments, the tower crane controller is configured with an AO control card, and the AO control card controls the accumulative counting of the synchronous counting variable in a first time period.

[0063] In some embodiments, communication between the on-tower RCM and the tower crane controller is through the ModbusTCP protocol.

[0064] S120: The on-tower RCM receives and saves the synchronous counting variable.

[0065] In some embodiments, the on-tower RCM sets a heartbeat status register to save the received synchronous counting variable, and adds a heartbeat status judgment mechanism for the tower crane controller through this register. In some of these embodiments, the judgment mechanism can be configured to be effective in the configuration interface (such as a WEB interface) for controlling the on-tower RCM.

[0066] S130: When the synchronous counting variables received by the RCM system at the on-tower RCM remain unchanged within a second time period, the on-tower RCM resets the outputs of its respective DO modules.

[0067] Among them, the second time period includes several first time periods, and the length of the second time period can both detect abnormalities in a timely manner and avoid misjudgment. In some embodiments, the second time period is 6 times the first time period.

[0068] In some embodiments, the heartbeat status judgment mechanism of the RCM on the tower crane for the tower crane controller is as follows: it judges whether the synchronous counting variable received by the RCM system on the tower crane remains unchanged within the second time period. If it remains unchanged, it is considered that there is an abnormality in the communication status between the tower crane controller and the RCM on the tower crane or the operating status of the tower crane controller. Thus, the RCM on the tower crane judges the abnormality through the received synchronous counting variable, so as to solve the problem that in the complex electromagnetic environment during the operation of the tower crane, the abnormal communication status between the tower crane controller and the RCM on the tower crane and the abnormal operating status of the tower crane controller itself can be detected. Compared with only detecting the abnormality of the IO ports of the RCM on the tower crane, more abnormalities can be detected.

[0069] In some embodiments, when there is an abnormality in the communication status between the tower crane controller and the RCM on the tower crane or the operating status of the tower crane controller, each DO module in the IO module of the RCM on the tower crane outputs OFF, causing the relay groups controlling each axis of the tower crane to lose power and the output commands for each tower crane gear of the tower crane to be reset. Thus, by each DO module in the IO module of the RCM on the tower crane outputting OFF, the relay groups controlling each axis of the tower crane lose power and the output commands for each tower crane gear of the tower crane are reset, so that each axis of the tower crane gradually stops moving, which is safer than only maintaining the movement state of each axis of the tower crane before the abnormality.

[0070] Figure 2B The flow of a specific implementation manner of the first embodiment of a method for realizing safety control of a tower crane is shown, including steps S210 to S230.

[0071] S210: Define an AO control card in the tower crane controller, control the synchronous counting variable to perform cumulative counting with the first time period as the cycle, and send the synchronous counting variable to the RCM on the tower crane.

[0072] Among them, add a custom AO card in the configuration of the tower crane controller. This card is actually not any hardware control device on the IO device, but a holding register used to judge whether the working status of the tower crane controller in the PLC application layer is normal.

[0073] Exemplarily, the Modbus address of this register is set to 430216, and TX_JIANCE_PLC is used to represent the synchronous counting variable saved in this register. This variable is a global variable that can perform Modbus TCP two-way communication with the RCM on the tower crane. In the POU of the tower crane controller, an automatic increment operation of adding 1 to the variable TX_JIANCE_PLC.enginValue is performed with the first time period as the cycle.

[0074] S220: The RCM on the tower crane enables the heartbeat status judgment mechanism of the tower crane controller, and receives and saves the synchronous counting variable through the heartbeat register.

[0075] Among them, the RCM on the tower sets a heartbeat register, enables the heartbeat status judgment mechanism of the tower crane controller on the WEB. The Modbus address of this register is the same as the Modbus address of the TX_JIANCE_PLC.enginValue address in the tower crane controller. The heartbeat register on the RCM on the tower reads the TX_JIANCE_PLC.enginValue data sent by the controller in real time.

[0076] S230: When the heartbeat status judgment mechanism of the RCM on the tower determines that the value of the heartbeat register remains unchanged within the second time period, all DO channels output OFF.

[0077] Among them, on the WEB of the RCM on the tower, the second time period is set to 6 first time periods. If the value of the RCM heartbeat register remains unchanged within the second time period, that is, the synchronous counting variable remains unchanged, then the RCM on the tower determines that the operating state of the tower controller is abnormal or the communication state with the tower controller is abnormal. At this time, the RCM on the tower automatically turns off all DO outputs of the aerial remote IO module, causing all the relay group coils to lose power, gradually stopping the movements of the hoisting, slewing, and luffing axes, and also resetting the output instructions of each gear of the tower crane. The gears of the hoisting, slewing, and luffing return to the zero position, thus avoiding potential dangers caused by the tower crane axes maintaining the movement state before the abnormality and further ensuring the safety of the system.

[0078] In summary, the technical solution of the first embodiment of a method for realizing safety control of a tower crane is used to detect the communication state between the tower crane controller and the RCM and the operating state of the tower crane controller, and reset the outputs of each DO module of the RCM on the tower when the tower crane controller is abnormal or the communication is abnormal, causing all the relay group coils to lose power and resetting the output instructions of each gear of the tower crane, thus avoiding potential dangers caused by the tower crane axes maintaining the movement state before the abnormality and improving the control safety of the unmanned tower crane.

[0079] Next, based on Figures 3 to 5 introduce the second embodiment of a method for realizing safety control of a tower crane.

[0080] On the basis of the first embodiment of a method for realizing safety control of a tower crane, the second embodiment of a method for realizing safety control of a tower crane adds a safety controller to detect the state of the RCM on the tower and cut off the control of the RCM on the tower over the tower crane relay group when the RCM on the tower is abnormal, further improving the control safety of the unmanned tower crane.

[0081] Figure 3 Shows the safety control flow of the RCM on the tower in the second embodiment of a method for realizing safety control of a tower crane, including steps S310 to S320.

[0082] S310: The RCM on the tower generates a square wave signal with a third time period as the cycle and sends it to the safety controller.

[0083] Among them, the safety controller is independent of the tower crane controller, so as to independently detect the operating state of the RCM on the tower. The safety controller and the original system are combined to form a closed-loop control system, thus improving the safety and reliability of the original system.

[0084] Exemplarily, the safety controller is a PLC, and its stability is greater than that of the RCM on the tower.

[0085] Among them, the square wave signal is not controlled by the tower crane controller and is directly connected to the input section of the safety controller, so that the counting of the square wave signal received by the safety controller accurately reflects the state of the RCM on the tower to detect whether the RCM on the tower is abnormal.

[0086] In some embodiments, the preset DO module of the control unit on the tower is connected to the DI module of the safety controller through a physical hard wire. The reliable transmission of the square wave signal is realized through the hard wire connection.

[0087] In some embodiments, the RCM on the tower is preconfigured to continuously output a square wave signal on a certain fixed DO channel, and the square wave period can be set on the WEB of the RCM on the tower.

[0088] When the S320 safety controller determines that the RCM on the tower is abnormal according to the square wave signal, it cuts off the control of the RCM on the tower over each axis of the tower crane.

[0089] Among them, the safety controller cuts off the control of the RCM on the tower over each axis of the tower crane, including: the safety controller outputs a safety signal through a DO module, and this safety signal cuts off the control of the RCM on the tower over each axis of the tower crane by driving a safety relay. This safety relay is an added relay and controls the connection between the common end of each DO module of the RCM on the tower and the tower crane relay group. Thus, when the RCM on the tower is abnormal, the control of the RCM on the tower over each axis of the tower crane is cut off, and each axis of the tower crane returns to the zero position and gradually stops moving, reducing the potential danger brought by each axis maintaining the motion state before the abnormality.

[0090] In some embodiments, the process by which the safety controller determines that the RCM on the tower is abnormal according to the counting includes: the safety controller starts counting from 0 for the received square wave signal within each fourth time period. The fourth time period includes several third time periods. The length of the fourth time period can detect the abnormality of the RCM on the tower in time and avoid misjudgment. Exemplarily, the fourth time period includes 6 third time periods; when the square wave count is less than or equal to the set value after passing through a fourth time period, it is determined that the RCM on the tower does not correctly output the square wave signal, and it is determined that the RCM on the tower is abnormal. The set value is the quotient of the fourth time period divided by the third time period, and it is generally set to 1. Thus, the independent safety controller accurately detects the abnormality of the RCM on the tower according to the received independent square wave signal.

[0091] The following combines Figure 4A andFigure 4B This describes the specific implementation of the safety control of the on-tower RCM in the second embodiment of the method for a tower crane to achieve safety control.

[0092] Figure 4A The figure shows the process of the specific implementation of the safety control of the on-tower RCM in the second embodiment of the method for a tower crane to achieve safety control, including steps S410 to S440.

[0093] Figure 4B The figure shows the wiring diagram of the tower crane control system applying the second embodiment of the method for a tower crane to achieve safety control. The safety controller is a PLC, and the upper computer is the upper computer of this PLC for managing this PLC. Relay 2 is a safety relay for connecting the common end of the relay group of the tower crane and each DO module of the on-tower RCM. The newly added PLC, upper computer, and relay 2 form a safe closed-loop control system with the on-tower RCM to detect the state of the on-tower RCM and control the tower crane relay group.

[0094] S410: The on-tower RCM outputs a square wave signal with a period of 100 ms through a preset DO channel.

[0095] Among them, one DI channel of the DO module of the on-tower RCM is locally connected to the safety controller PLC through hard wires.

[0096] Among them, the square wave period is set to 100 ms on the WEB interface of the on-tower RCM.

[0097] S420: The safety controller counts from 0 for the received square wave signal within 600 ms.

[0098] Among them, this 600 ms is set on the upper computer of the safety controller. On the one hand, it can timely detect the abnormality of the on-tower RCM, and on the other hand, it can avoid false detection.

[0099] Among them, a counter for counting the square wave signal output by the on-tower RCM is configured in the safety controller PLC through a ladder diagram. Its period is 6 * 100 ms. It is defined that the counter in the safety controller PLC adds 1 for each received square wave signal within the 600 ms counting period, and the counter is cleared to 0 when 600 ms arrives.

[0100] S430: When the square wave count within 600 ms is always less than or equal to 1, the safety controller cuts off the connection between the tower crane relay group and the common end of each DO module of the on-tower RCM through the newly added safety relay.

[0101] Among them, when the square wave count within 600 ms is always less than or equal to 1, it can be considered that the RCM on the tower has an abnormality, and the connection between the tower crane relay group and the common terminal of each DO module of the RCM on the tower is cut off, so that each axis of the tower crane returns to the zero position and gradually stops moving.

[0102] Among them, through the ladder diagram, it is defined in the safety controller that when the count of the counter (i.e., the square wave count) in the safety controller PLC within the 600 ms counting cycle is less than or equal to 1, a safety signal is output and self-locked by a DO channel of the safety controller PLC to cut off the connection between the tower crane relay group and the common terminal of each DO module of the RCM on the tower.

[0103] S440: The safety controller uploads the status of the RCM on the tower to the upper computer for display and analysis.

[0104] Among them, the status value of the RCM on the tower includes the number of times the RCM on the tower has an abnormality.

[0105] Among them, through the ladder diagram, it is defined in the safety controller that the safety controller PLC communicates with its upper computer through the MODBUS TCP protocol.

[0106] In summary, based on Embodiment 1 of the method for realizing safety control of a tower crane, Embodiment 2 of the method for realizing safety control of a tower crane adds a safety controller to detect the status of the RCM on the tower and cuts off the control of the tower crane relay group by the RCM on the tower when the RCM on the tower has an abnormality, further improving the control safety of the unmanned tower crane.

[0107] Next, in combination with Figure 5 introduce Embodiment 1 of a tower crane control system.

[0108] Embodiment 1 of a tower crane control system runs the method described in Embodiment 1 of the method for realizing safety control of a tower crane and has all the advantages of Embodiment 1 of the method for realizing safety control of a tower crane.

[0109] Figure 5 The structure of Embodiment 1 of a tower crane control system is shown, including: a tower crane controller 10, an RCM 20 on the tower, and a tower crane relay group 30.

[0110] The tower crane controller 10 is used to accumulate and count the synchronous counting variable in the tower crane controller at a first time period as a cycle and send the synchronous counting variable to the RCM on the tower. Among them, the tower crane controller 10 is connected to the RCM 20 on the tower through a network switch. For its working principle and advantages, please refer to step S110 of Embodiment 1 of the method for realizing safety control of a tower crane.

[0111] The RCM 20 on the tower is used to reset the outputs of its respective DO modules when the received synchronization count variables remain unchanged within the second time period, and the second time period includes several first time periods. For its working principle and advantages, please refer to steps S120 and S130 of Embodiment 1 of a method for realizing safety control of a tower crane.

[0112] The tower crane relay group 30 is used to control the tower crane by using the signals output by the DO modules of the RCM 20 on the tower, and is connected to the tower crane through an aviation plug.

[0113] The following combines Figure 6 to introduce Embodiment 2 of a tower crane control system.

[0114] Embodiment 2 of a tower crane control system runs the method described in Embodiment 2 of a method for realizing safety control of a tower crane, and has all the advantages of Embodiment 2 of a method for realizing safety control of a tower crane.

[0115] Figure 6 The structure of Embodiment 2 of a tower crane control system is shown, including: a tower crane controller 10, an RCM 20 on the tower, a tower crane relay group 30, a safety controller 40, a safety relay 50, and a host computer 60.

[0116] For the working principle and advantages of the tower crane controller 10, please refer to Embodiment 1 of a tower crane control system.

[0117] On the basis of Embodiment 1 of a tower crane control system, the RCM 20 on the tower is further used to generate a square wave signal and output it to a DI channel of the safety controller 40 through a preset DO channel. For the working principle and advantages of the added part, please refer to step S310 of the safety control of the RCM on the tower in Embodiment 2 of a tower crane control system.

[0118] On the basis of Embodiment 1 of a tower crane control system, for the working principle and advantages of the tower crane relay group 30, the common terminal of each DO module of the RCM 20 on the tower is connected to the tower crane relay group 30 through the safety relay 50.

[0119] The safety controller 40 is used to cut off the control of the RCM on the tower for each axis of the tower crane when it determines that the RCM on the tower is abnormal according to the square wave signal. For its working principle and advantages, please refer to step S320 of the safety control of the RCM on the tower in Embodiment 2 of a tower crane control system.

[0120] The safety relay 50 is used to disconnect the common terminal of each DO module of the RCM 20 on the tower from the tower crane relay group 30 under the control of the safety signal output when the safety controller 40 determines that the RCM on the tower is abnormal, so as to disconnect the control of each DO module of the RCM 20 on the tower crane relay group 30.

[0121] The host computer 60 is used to receive the status uploaded by the RCM 20 on the tower and display and analyze it.

[0122] Among them, the tower crane controller 10 is connected to the RCM 20 on the tower through a network switch to achieve signal transmission at a flexible distance; the host computer 60 is connected to the safety controller 40 through a network switch, which is also convenient for the flexible placement of the host computer 60; the preset DO module of the RCM 20 on the tower is connected to the DI module of the safety controller 40 through a physical hard wire to achieve reliable transmission of square wave signals.

[0123] Note that the above is only the preferred embodiment of the present invention and the applied technical principles. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described here, and various obvious changes, re-adjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments. Without departing from the concept of the present invention, more other equivalent embodiments can be included, all of which belong to the protection scope of the present invention.

Claims

1. A method for realizing safety control of a tower crane, characterized in that, Including: The tower crane controller accumulatively counts the synchronization count variable in a cycle with the first time period, and sends the synchronization count variable to the on-tower control unit; When the synchronization count variables received by the on-tower control unit remain unchanged within the second time period, the on-tower control unit resets the outputs of its respective DO modules, and the second time period includes several first time periods.

2. The method according to claim 1, characterized in that, The on-tower control unit resets the outputs of its respective DO modules, specifically including: The on-tower control unit controls the tower crane relays of each axis of the tower crane to lose power and resets the output commands of each gear of the tower crane.

3. The method according to claim 1, characterized in that, Also including: The on-tower control unit generates a square wave signal with a third time period as the cycle and sends it to the safety controller. The safety controller is independent of the tower crane controller, and the stability of the safety controller is greater than that of the on-tower control unit; When the safety controller determines that the on-tower control unit is abnormal according to the square wave signal, it cuts off the control of the on-tower control unit over each axis of the tower crane.

4. The method according to claim 3, characterized in that, The safety controller cuts off the control of the on-tower control unit over each axis of the tower crane, including: The safety controller outputs a safety signal through a DO module, and this safety signal cuts off the control of the on-tower control unit over each axis of the tower crane.

5. The method according to claim 3, characterized in that, The process by which the safety controller determines that the on-tower control unit is abnormal according to the square wave signal includes: The safety controller accumulatively counts the square wave signal starting from 0 within each fourth time period, and the fourth time period includes several third time periods; When the count is less than or equal to the set value after passing through one fourth time period, it is determined that the on-tower control unit is abnormal, and this set value is less than the quotient of the fourth time period divided by the third time period.

6. The method according to claim 5, characterized in that, The safety controller uploads the status of the on-tower control unit to the upper computer, and the status at least includes the number of times the on-tower control unit has an abnormality.

7. A tower crane control system, characterized in that, Including: A tower crane controller, which is used to accumulatively count the synchronization count variable in a cycle with the first time period and send the synchronization count variable to the on-tower control unit. The tower crane controller is connected to the on-tower control unit through a network switch; An on-tower control unit, which is used to reset the outputs of its respective DO modules when it detects that the received synchronization count variables remain unchanged within the second time period. The second time period includes several first time periods.

8. The system according to claim 7, characterized in that, Also including: The on-tower control unit is also used to generate a square wave signal with a third time period as the cycle and send it to the safety controller; A safety controller, which is used to cut off the control of the on-tower control unit over each axis of the tower crane when it determines that the on-tower control unit is abnormal according to the square wave signal. The safety controller is independent of the tower crane controller, and the stability of the safety controller is greater than that of the on-tower control unit.

9. The system according to claim 8, characterized in that, Also including: A safety relay, which is used to cut off the connection between each DO module and the tower crane relay group when the safety controller detects that the on-tower control unit is abnormal.

10. The system according to claim 8, characterized in that, The preset DO module of the on-tower control unit is connected to the DI module of the safety controller through a physical hard wire.

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