A multiple interlock adaptive safety protection control system and method for a crane

Abstract

A multiple interlock adaptive safety protection control system and method for a crane, comprising a PLC and a forward obstacle detection unit, a reverse obstacle detection unit, a trolley traveling mechanism encoder, a crab traveling mechanism encoder and an altimeter detection and receiving device connected to the PLC. Among them, the altimeter detection and receiving device is connected to an altimeter detection and transmitting device; the altimeter detection and transmitting device includes a rolling door height detection device located at the workshop rolling door. The rolling door height detection device is connected to the transmitting device, and the transmitting device is wirelessly connected to the altimeter detection and receiving device. The present invention has the following beneficial effects: 1. It can implement area protection near the rolling door, and the crane cannot pass through the rolling door when it does not meet the safety passing conditions; 2. It can detect the lifting state of the rolling door in real time, predict the distance from the rolling door in advance to decelerate the crane first, and can make the crane stop urgently in case of area protection failure to avoid collision with the rolling door.

Description

Technical Field

[0001] The invention belongs to the field of crane electrical control, and particularly relates to a multiple interlock adaptive safety protection control system and method for a crane. Background Art

[0002] Large-tonnage cranes are special operating equipment, mostly used for material handling in industrial fields. The working operation distance of the crane is up to several hundred meters. Different working areas are set in the workshop, and rolling doors are installed at the entrances and exits of each area. During the operation of the crane, there is a situation where the rolling door collides with the crane when it has not been fully lifted to a safe height. How to safely, effectively, and reliably ensure the safety interlock between the crane and the rolling door is one of the important issues for ensuring the safe production of the workshop at present.

[0003] For the old crane electric control system, only by the operator observing the lifting state of the rolling door in the driving path of the crane during the operation of the crane for manual intervention to avoid the collision between the crane and obstacles. This method requires the operator to maintain a high degree of attention, but it cannot ensure the 100% safety of the crane during operation. Summary of the Invention

[0004] The technical problem to be solved by the present invention is: how to improve the safety of the crane during operation. The present invention provides a multiple interlock safety protection control method.

[0005] To solve the above problems, the present invention is realized by the following technical solutions:

[0006] A multiple interlock adaptive safety protection control system for a crane, including a PLC, a forward obstacle detection unit, a reverse obstacle detection unit, a trolley running mechanism encoder, a hoist running mechanism encoder, and a height gauge detection and receiving device connected to the PLC. Among them, the height gauge detection and receiving device is connected to a height gauge detection and transmitting device; the height gauge detection and transmitting device includes a rolling door height detection device located at the rolling door of the workshop. The rolling door height detection device is connected to a transmitting device, and the transmitting device is wirelessly connected to the height gauge detection and receiving device.

[0007] The rolling door height detection device is a diffuse reflection sensor. The fact that the sensor is located at the "rolling door of the workshop" means that the sensor is located on the track of the driving direction of the crane trolley; and the installation height of the rolling door height detection device is lower than the highest position of the rolling door lift and higher than the lowest height allowed for the crane to pass.

[0008] The PLC includes a PLC processing unit, the PLC processing unit is connected to a PLC sub-station module, and the PLC sub-station module is connected to a PLC input module A02; the PLC processing unit is connected to a trolley running mechanism encoder, a crab running mechanism encoder, a switch, an altimeter detection receiving device, a forward obstacle detection unit, and a reverse obstacle detection unit.

[0009] The forward obstacle detection unit includes a trolley forward running detection deceleration normally closed contact and a trolley forward running detection stop normally closed contact connected to the input end of the PLC processing unit. Among them, the trolley forward running detection deceleration normally closed contact is connected to a trolley forward running deceleration relay, and the trolley forward running detection deceleration normally open contact is connected to the PLC input module; the trolley forward running detection stop normally closed contact is connected to a trolley forward running stop relay, and the trolley forward running stop normally open contact is connected to the PLC input module;

[0010] The reverse obstacle detection unit includes a trolley reverse running detection deceleration normally closed contact and a trolley reverse running detection stop normally closed contact connected to the input end of the PLC processing unit. Among them, the trolley reverse running detection deceleration normally closed contact is connected to a trolley reverse running deceleration relay, and the trolley reverse running detection deceleration normally open contact is connected to the PLC input module; the trolley reverse running detection stop normally closed contact is connected to a trolley reverse running stop relay, and the trolley reverse running stop normally open contact is connected to the PLC input module.

[0011] A height detection relay is provided in the altimeter detection receiving device, and the normally open contact of the height detection relay is connected to the PLC input module.

[0012] A multiple interlock adaptive safety protection control method for a crane using the above system includes the following control steps:

[0013] Step 1: A trolley running mechanism encoder and a crab running mechanism encoder are configured on the crane. The trolley running mechanism encoder and the crab running mechanism encoder calculate the running positions of the trolley and the crab in real time. When the PLC of the crane does not receive any passable signal, the crane cannot pass through the rolling door and can only run near the rolling door;

[0014] Step 2: The PLC determines whether the current running positions of the trolley and the crab are more than 10 meters away from the position of the rolling door. At the same time, the altimeter detection transmitting device detects the height of the rolling door in real time; when the distance is more than 10 meters, the PLC continues to detect and judge; when the distance is less than 10 meters and the rolling door has not been raised to a safe height, the rolling door height detection sensor will detect the rolling door in front of the crane's running direction, and the PLC uses the forward obstacle detection unit and the reverse obstacle detection unit to make the crane decelerate.

[0015] Step 3: The PLC determines whether the current operating positions of the trolley and the crane are more than 2 meters away from the rolling door. Meanwhile, the height gauge detection transmitter continuously detects the height of the rolling door. When the distance is more than 2 meters, Step 2 is executed. When the distance is less than 2 meters and the rolling door has not been raised to the safe height, the rolling door height detection sensor will detect the rolling door in front of the crane's operation. The PLC uses the forward obstacle detection unit and the reverse obstacle detection unit to stop the crane.

[0016] Step 4: After the height gauge detection transmitter detects that the rolling door has been raised to the safe height and the rolling door height detection sensor can no longer detect the rolling door in front, it indicates that the rolling door has been raised to a height that allows the crane to pass safely, and the crane can pass through the rolling door safely.

[0017] The transmission signal of the height gauge detection transmitter is a continuous signal, that is, the height detection relay is continuously energized. Then, the normally open contact of the height detection relay closes, continuously giving a feedback signal to the PLC input module to ensure that the crane PLC can safely receive the signal status. When the feedback signal is interrupted, the height gauge detection receiver installed on the crane will also immediately be unable to receive the signal. When the signal is interrupted, the PLC controls the forward obstacle detection unit and the reverse obstacle detection unit, and the crane is not allowed to pass through the rolling door.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. It can implement area protection near the rolling door, and the crane cannot pass through the rolling door when it does not meet the safe passing conditions.

[0020] 2. It can continuously detect the lifting state of the rolling door, predict the distance from the rolling door in advance to decelerate the crane. If the area protection fails, it can make the crane stop urgently to avoid collision with the rolling door.

[0021] 3. The lifting height information of the rolling door and the position information of the crane are interconnected in real time, and the area protection can be lifted online.

[0022] 4. When the rolling door is closing or lifting, the crane can still work near the rolling door. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is the topological structure diagram of the present invention;

[0024] Figure 2 is the control circuit diagram of the present invention;

[0025] Figure 3 is the control flow chart of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0026] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0027] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0028] As Figure 1 — Figure 3 As shown, a multiple interlock adaptive safety protection control system for a crane includes a PLC and a forward obstacle detection unit, a reverse obstacle detection unit, a trolley travel mechanism encoder, a hoist travel mechanism encoder, and an altimeter detection and receiving device connected to the PLC. Among them, the altimeter detection and receiving device is connected to the altimeter detection and transmitting device; the altimeter detection and transmitting device includes a rolling door height detection device located at the rolling door of the workshop. The rolling door height detection device is connected to the transmitting device, and the transmitting device is wirelessly connected to the altimeter detection and receiving device.

[0029] Among them, the rolling door height detection device is a diffuse reflection sensor. The fact that this sensor is located at the "rolling door of the workshop" means that this sensor is located on the track of the crane's trolley travel direction (bidirectional). Therefore, it is sufficient for this sensor to be located on the trolley travel track, and it can be 10 meters away from the rolling door (adjustable), and it has the function of adjustable detection distance and dual-point output. The installation height of the rolling door height detection device should be lower than the highest position of the rolling door lift and higher than the lowest height allowed for the crane to pass.

[0030] When the rolling door has not been lifted to the safe height, the forward obstacle detection unit will detect the rolling door in front of the crane during operation. At this time, the crane decelerates when it is 10 meters away from the rolling door (adjustable), and during the operation, the area protection failure is avoided. When it is 2 meters away from the rolling door (adjustable), the crane stops running to avoid accidental collision.

[0031] When the rolling door has been lifted to the safe height, the forward obstacle detection unit cannot detect the rolling door in front, indicating that the rolling door has been lifted to the height allowing the crane to pass safely. At this time, theoretically, the crane can pass through the rolling door safely.

[0032] As Figure 2As shown in the figure, the PLC includes a PLC processing unit A00. The PLC processing unit A00 is connected to a PLC sub-station module A01, and the PLC sub-station module A01 is connected to a PLC input module A02. The PLC processing unit A00 is connected to a trolley traveling mechanism encoder, a crab traveling mechanism encoder, a switch, a height gauge detection and receiving device, a forward obstacle detection unit, and a reverse obstacle detection unit. In this system structure, the PLC processing unit A00, the PLC sub-station module A01, and the PLC input module A02 are mainly used for data processing. The trolley traveling mechanism encoder and the crab traveling mechanism encoder are used to realize the position positioning of the trolley and the crab and achieve area protection. The switch is used to expand the interface. The forward obstacle detection unit and the reverse obstacle detection unit are used for the deceleration and stop of the crane. The height gauge detection and receiving device is used to receive the height status information of the lifting door. The above devices are all installed on the crane. The height gauge detection and transmitting device is used to detect the lifting height of the lifting door and feedback the status of the lifting door to the height gauge detection and receiving device, and is installed at the workshop lifting door.

[0033] The forward obstacle detection unit 12 - A02 includes a normally closed contact K03 - 2 for detecting deceleration of the trolley moving forward and a normally closed contact K04 - 2 for detecting stop of the trolley moving forward, both of which are connected to the input end of the PLC processing unit A00 and are located inside the forward obstacle detection unit 12 - A02. Among them, the normally closed contact K03 - 2 for detecting deceleration of the trolley moving forward is connected to a relay K03 for decelerating the trolley moving forward, and a normally open contact K03 - 1 for detecting deceleration of the trolley moving forward is connected to the PLC input module A02. The normally closed contact K04 - 2 for detecting stop of the trolley moving forward is connected to a relay K04 for stopping the trolley moving forward, and a normally open contact K04 - 1 for detecting stop of the trolley moving forward is connected to the PLC input module A02. In this way, when the height detection device of the lifting door detects the distance to an obstacle, for example, when it reaches 10 meters, the state of the normally closed contact K03 - 2 for detecting deceleration of the trolley moving forward changes, and when it reaches 2 meters, the state of the normally closed contact K04 - 2 for detecting stop of the trolley moving forward changes. In this way, the state of the corresponding relay K03 for decelerating the trolley moving forward or the relay K04 for stopping the trolley moving forward changes, so that the state of the normally open contact K03 - 1 for detecting deceleration of the trolley moving forward or the normally open contact K04 - 1 for detecting stop of the trolley moving forward changes, and the PLC input module A02 receives this feedback signal.

[0034] The PLC processing unit A00 receives the corresponding status change and outputs an instruction to decelerate the crane forward or backward. At the same time, the encoder of the trolley running mechanism and the encoder of the crab running mechanism send the actual position of the crane to the PLC processing unit, which is compared with the region protection position set in the system. When the system region protection fails and the obstacle forward or backward detection unit detects that the distance to the obstacle is less than 2 meters, it transmits an action signal to the PLC processing unit, and the PLC processing unit outputs an emergency stop instruction to stop the crane.

[0035] The reverse obstacle detection unit 12 - A01 includes a normally - closed contact K01 - 2 for detecting deceleration of the crab running in reverse and a normally - closed contact K02 - 2 for detecting stop of the crab running in reverse, both of which are connected to the input terminal of the PLC processing unit A00 and are located inside the reverse obstacle detection unit 12 - A01. Among them, the normally - closed contact K01 - 2 for detecting deceleration of the crab running in reverse is connected to the reverse running deceleration relay K01 of the crab, and the normally - open contact K01 - 1 for detecting deceleration of the crab running in reverse is connected to the PLC input module A02; the normally - closed contact K02 - 2 for detecting stop of the crab running in reverse is connected to the reverse running stop relay K02 of the crab, and the normally - open contact K02 - 1 for detecting stop of the crab running in reverse is connected to the PLC input module A02. In this way, when the height detection device of the rolling - up door detects the distance to the obstacle, for example, when it reaches 10 meters, the state of the normally - closed contact K01 - 2 for detecting deceleration of the crab running in reverse changes, and when it reaches 2 meters, the state of the normally - closed contact K02 - 2 for detecting stop of the crab running in reverse changes. Thus, the state of the corresponding reverse running deceleration relay K01 or reverse running stop relay K02 of the crab changes, which in turn causes the state of the normally - closed contact K01 - 2 for detecting deceleration of the crab running in reverse or the normally - closed contact K02 - 2 for detecting stop of the crab running in reverse to change, and the PLC input module A02 receives this feedback signal.

[0036] It should be noted that the area protection system also includes trolley running monitoring. The encoder of the trolley running mechanism communicates with the PLC in real - time, transmitting the position information of the trolley to the PLC, which is used to determine whether the position of the trolley is at the origin. If it is not at the origin position, the crane crab running will be stopped. After manually adjusting the trolley to the origin position, the crane crab mechanism resumes operation to meet the condition that the crane can pass through the rolling - up door normally and avoid collisions.

[0037] A height detection relay K05 is provided in the height meter detection and receiving device, and the normally - open contact K05 - 1 of the height detection relay is connected to the PLC input module A02.

[0038] As Figure 3 shown, a multiple - interlock adaptive safety protection control method for a crane includes the following control steps:

[0039] Step 1: Configure an encoder for the trolley traveling mechanism and an encoder for the bridge traveling mechanism on the crane. The encoders of the trolley traveling mechanism and the bridge traveling mechanism calculate the positions of the trolley and the bridge in real time, which are used to set area protection at the return points of the rolling door. When the PLC of the crane does not receive any passable signal, the crane cannot pass through the rolling door and can only run near the rolling door.

[0040] Step 2: The PLC determines whether the current positions of the trolley and the bridge are more than 10 meters away from the position of the rolling door. At the same time, the height gauge detection transmitter detects the height of the rolling door in real time. When the distance is more than 10 meters, the PLC continues to detect and judge. When the distance is less than 10 meters and the rolling door has not been lifted to the safe height, the forward obstacle detection unit and the reverse obstacle detection unit will detect the rolling door in front of the crane's operation. The PLC uses the forward obstacle detection unit and the reverse obstacle detection unit to decelerate the crane during operation to avoid the failure of area protection.

[0041] Step 3: The PLC determines whether the current positions of the trolley and the bridge are more than 2 meters away from the position of the rolling door. At the same time, the height gauge detection transmitter detects the height of the rolling door in real time. When the distance is more than 2 meters, step 2 is executed. When the distance is less than 2 meters and the rolling door has not been lifted to the safe height, the forward obstacle detection unit and the reverse obstacle detection unit detect the rolling door in front of the crane's operation. The PLC uses the forward obstacle detection unit and the reverse obstacle detection unit to stop the crane, so as to achieve the stop of the crane at 2 meters (adjustable) to avoid accidental collision.

[0042] Step 4: After the height gauge detection transmitter detects that the rolling door has been lifted to the safe height and the rolling door height detection sensor cannot detect the rolling door in front, it indicates that the rolling door has been lifted to the height allowing the crane to pass safely. At this time, theoretically, the crane can pass through the rolling door safely.

[0043] The working principle of the present invention is:

[0044] To ensure the safety between the crane and the rolling door, relying solely on manual judgment whether the crane can pass is a solution with relatively low reliability.

[0045] A height gauge detection transmitter is configured at the rolling door to detect whether the rolling door has been lifted to the highest position. The transmission signal of this height gauge detection transmitter is a continuous signal, that is, when the height detection relay K05 is continuously powered on, the normally open contact K05-1 of the height detection relay closes, continuously giving a feedback signal to the PLC input module A02 to ensure that the crane PLC can safely receive the signal status. When the feedback signal is interrupted, the height gauge detection receiver assembled on the crane will also immediately be unable to receive the signal. When the signal is interrupted, the PLC immediately outputs an instruction to stop the operation of the crane, and the crane is not allowed to pass through the rolling door.

[0046] When the feedback signal is normal, the height gauge detection transmitter is used to detect the lifting height of the rolling door. When the height gauge detection transmitter detects that the rolling door has been lifted to the highest position, its transmitter sends a confirmation signal to the height gauge detection receiver on the crane. After the PLC processes the signal, the area protection is released. After double detection, it is judged that the rolling door has reached the safe height, and the crane can pass through the rolling door.

[0047] The above are only the preferred embodiments of the present invention. It should be noted that for those skilled in the art, without departing from the overall concept of the present invention, several changes and improvements can still be made, and these should also be regarded as the protection scope of the present invention.

Claims

1. A multi-chain adaptive safety protection control method for a crane, characterized in that: It includes a safety protection control system, which includes a PLC and a forward obstacle detection unit, a reverse obstacle detection unit, a trolley traveling mechanism encoder, a crab traveling mechanism encoder, and an altimeter detection receiving device connected to the PLC. Among them, the altimeter detection receiving device is connected to the altimeter detection transmitting device; the altimeter detection transmitting device includes a rolling door height detection device located at the workshop rolling door. The rolling door height detection device is connected to the transmitting device, and the transmitting device is wirelessly connected to the altimeter detection receiving device; The control method includes the following control steps: Step 1: Install a crab traveling mechanism encoder and a trolley traveling mechanism encoder on the crane. The crab traveling mechanism encoder and the trolley traveling mechanism encoder calculate the traveling positions of the crab and the trolley in real time. When the PLC of the crane does not receive any signal allowing passage, the crane cannot pass through the rolling door and can only run near the rolling door; Step 2: The PLC determines whether the current traveling positions of the crab and the trolley are more than 10 meters away from the position of the rolling door. At the same time, the altimeter detection transmitting device detects the height of the rolling door in real time; when the distance is more than 10 meters, the PLC continues to detect and judge; when the distance is less than 10 meters and the rolling door has not been lifted to the safe height, the rolling door height detection device will detect the rolling door in front of the crane's running direction, and the PLC uses the forward obstacle detection unit and the reverse obstacle detection unit to slow down the operation of the crane; Step 3: The PLC determines whether the current traveling positions of the crab and the trolley are more than 2 meters away from the position of the rolling door. At the same time, the altimeter detection transmitting device detects the height of the rolling door in real time; when the distance is more than 2 meters, step 2 is executed; when the distance is less than 2 meters and the rolling door has not been lifted to the safe height, the rolling door height detection sensor will detect the rolling door in front of the crane's running direction, and the PLC uses the forward obstacle detection unit and the reverse obstacle detection unit to stop the operation of the crane; Step 4: After the altimeter detection transmitting device detects that the rolling door has been lifted to the safe height and the rolling door height detection sensor cannot detect the rolling door in front, it indicates that the rolling door has been lifted to the height allowing the crane to pass safely, and the crane can pass through the rolling door safely.

2. The multi-chain adaptive safety protection control method for a crane according to claim 1, wherein: The rolling door height detection device is a diffuse reflection sensor. The statement that the sensor is located at the "workshop rolling door" means that the sensor is located on the track of the crane's crab traveling direction; and the installation height of the rolling door height detection device should be lower than the highest position of the rolling door lifting and higher than the lowest height allowing the crane to pass.

3. The multiple interlock adaptive safety protection control method for a crane according to claim 1, wherein: The PLC includes a PLC processing unit (A00). The PLC processing unit (A00) is connected to a PLC sub-station module (A01), and the PLC sub-station module (A01) is connected to a PLC input module (A02); the PLC processing unit (A00) is connected to the crab traveling mechanism encoder, the trolley traveling mechanism encoder, a switch, the altimeter detection receiving device, the forward obstacle detection unit, and the reverse obstacle detection unit.

4. The multiple interlock adaptive safety protection control method for a crane according to claim 3, characterized in that: The described forward obstacle detection unit includes a normally closed contact (K03-2) for detecting deceleration during the forward movement of the cart and a normally closed contact (K04-2) for detecting stop during the forward movement of the cart, both of which are connected to the input end of the PLC processing unit (A00). Among them, the normally closed contact (K03-2) for detecting deceleration during the forward movement of the cart is connected to the forward movement deceleration relay (K03) of the cart, and the normally open contact (K03-1) for detecting deceleration during the forward movement of the cart is connected to the PLC input module (A02); the normally closed contact (K04-2) for detecting stop during the forward movement of the cart is connected to the forward movement stop relay (K04) of the cart, and the normally open contact (K04-1) for detecting stop during the forward movement of the cart is connected to the PLC input module (A02). The described reverse obstacle detection unit includes a normally closed contact (K01-2) for detecting deceleration during the reverse movement of the cart and a normally closed contact (K02-2) for detecting stop during the reverse movement of the cart, both of which are connected to the input end of the PLC processing unit (A00). Among them, the normally closed contact (K01-2) for detecting deceleration during the reverse movement of the cart is connected to the reverse movement deceleration relay (K01) of the cart, and the normally open contact (K01-1) for detecting deceleration during the reverse movement of the cart is connected to the PLC input module (A02); the normally closed contact (K02-2) for detecting stop during the reverse movement of the cart is connected to the reverse movement stop relay (K02) of the cart, and the normally open contact (K02-1) for detecting stop during the reverse movement of the cart is connected to the PLC input module (A02).

5. A multiple interlock adaptive safety protection control method for a crane according to claim 1, characterized in that: A height detection relay (K05) is provided in the described height gauge detection and receiving device, and the normally open contact (K05-1) of the height detection relay is connected to the PLC input module (A02).

6. The multi-chain adaptive safety protection control method for a crane according to claim 1, characterized in that: The transmission signal of the height gauge detection and transmitting device is a continuous signal, that is, when the height detection relay (K05) is continuously powered on, the normally open contact (K05-1) of the height detection relay is closed, continuously giving a feedback signal to the PLC input module (A02) to ensure that the crane PLC can safely receive the signal status. When the feedback signal is interrupted, the height gauge detection and receiving device assembled on the crane will immediately be unable to receive the signal. When the signal is interrupted, the PLC controls the forward obstacle detection unit and the reverse obstacle detection unit, and the crane is not allowed to pass through the lifting door.

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