Electric rubber-tired crane and control system thereof

Abstract

The invention relates to an electric rubber-tired crane and a control system thereof, the control system comprises an operation table, a PLC, a lifting frequency converter and a rotary frequency converter, the operation table is provided with a cam controller and a master controller, and the cam controller and the master controller are both used for inputting crane control signals; the PLC is electrically connected with the cam controller and the master controller, and is used for receiving a crane control signal and outputting a corresponding frequency converter control signal; the lifting frequency converter is electrically connected with the PLC and the lifting motor, and is used for controlling the lifting motor, so that a lifting hook of the electric rubber-tyred crane ascends or descends; and the rotary frequency converter is electrically connected with the PLC and the rotary motor and is used for controlling the rotary motor, so that a suspension arm of the electric rubber-tyred crane rotates leftwards or rightwards. Two control modes of the crane are achieved, a loading and unloading driver can select the corresponding control mode for training and learning according to the work type, and the training cost is reduced.

Description

Technical Field

[0001] This application relates to the field of crane technology, and in particular to an electric tire crane and its control system. Background Technology

[0002] Traditional electric tire-mounted cranes use three-phase power, with an electric motor driving the hoisting and slewing mechanisms to achieve free lifting, lowering, and rotating of loads. Electric tire-mounted cranes typically use cam controllers for control. These controllers directly control the main circuit's on / off state through their finger contacts, enabling operations such as starting, braking, changing direction, and connecting / disconnecting resistors. Electric tire-mounted cranes are suitable for loading and unloading operations in ports and docks. However, the control methods of traditional marine cranes are completely different, leading to higher costs in training loading and unloading operators. Summary of the Invention

[0003] Therefore, it is necessary to provide a control system for an electric tire crane that can be used for teaching and training, addressing the aforementioned technical problems.

[0004] In a first aspect, this application provides a control system for an electric tire-mounted crane, comprising:

[0005] The control panel is equipped with a cam controller and a master controller. Both the cam controller and the master controller are used to input crane control signals, which include lifting control signals, lowering control signals, left rotation control signals, and right rotation control signals.

[0006] The PLC is electrically connected to the cam controller and the master controller respectively. It is used to receive the crane control signal, process the crane control signal, and output the corresponding frequency converter control signal. The frequency converter control signal includes the hoisting frequency converter control signal and the rotation frequency converter control signal.

[0007] A lifting frequency converter is electrically connected to the PLC and the lifting motor of the electric tire crane. It is used to control the lifting motor according to the control signal output by the lifting frequency converter from the PLC, so as to raise or lower the hook of the electric tire crane.

[0008] A rotary frequency converter is electrically connected to the PLC and the rotary motor of the electric tire crane. It is used to control the rotary motor according to the rotary frequency converter control signal output by the PLC, so as to make the boom of the electric tire crane rotate left or right.

[0009] In one embodiment, the control system of the electric tire crane further includes a selector switch disposed on the control panel, the selector switch being configured to have a first mode and a second mode; when the selector switch is in the first mode, the PLC is electrically connected to the cam controller for receiving crane control signals input by the cam controller; when the selector switch is in the second mode, the PLC is electrically connected to the master controller for receiving crane control signals input by the master controller.

[0010] In one embodiment, the cam controller includes:

[0011] A first cam controller is located on the first side of the operating panel and is used to input the upward control signal and the downward control signal;

[0012] The second cam controller is located on the second side of the control panel and is used to input the left-hand control signal and the right-hand control signal.

[0013] In one embodiment, the first cam controller is configured to have at least a first upshift and a second upshift along a first direction, and at least a first downshift and a second downshift along a second direction;

[0014] When the first cam controller rotates to the first lifting gear along the first direction, the PLC outputs a corresponding lifting frequency conversion signal to the lifting frequency converter to control the lifting motor to operate, so that the hook of the electric tire crane rises and the lifting speed is the first lifting speed.

[0015] When the first cam controller rotates to the second lifting position along the first direction, the PLC outputs the corresponding lifting frequency conversion signal to the lifting frequency converter to control the lifting motor to operate, so that the hook of the electric tire crane rises and the lifting speed is the second lifting speed.

[0016] When the first cam controller rotates to the first lowering gear along the second direction, the PLC outputs a corresponding lifting frequency conversion signal to the lifting frequency converter to control the lifting motor to operate, so that the hook of the electric tire crane lowers and the lowering speed is the first lowering speed;

[0017] When the first cam controller rotates to the second lowering position along the second direction, the PLC outputs a corresponding lifting frequency converter signal to the lifting frequency converter to control the lifting motor to operate, so that the hook of the electric tire crane lowers at the second lowering speed.

[0018] In one embodiment, the second cam controller is configured to have at least a first left-hand rotation position and a second left-hand rotation position along a first direction, and at least a first right-hand rotation position and a second right-hand rotation position along a second direction.

[0019] When the second cam controller rotates to the first left-hand rotation position along the first direction, the PLC outputs a corresponding rotation frequency converter signal to the rotation frequency converter to control the rotation motor to operate, so that the boom of the electric tire crane rotates to the left and the rotation speed is the first left-hand rotation speed.

[0020] When the second cam controller rotates to the second left-hand rotation position along the first direction, the PLC outputs a corresponding rotation frequency converter signal to the rotation frequency converter to control the rotation motor to operate, so that the boom of the electric tire crane rotates to the left and the rotation speed is the second left-hand rotation speed;

[0021] When the second cam controller rotates to the first right-hand rotation position along the second direction, the PLC outputs a corresponding rotation frequency converter signal to the rotation frequency converter to control the rotation motor to operate, so that the boom of the electric tire crane rotates to the right and the rotation speed is the first right-hand rotation speed;

[0022] When the second cam controller rotates to the second right-hand rotation position along the second direction, the PLC outputs a corresponding rotation frequency converter signal to the rotation frequency converter to control the rotation motor to operate, so that the boom of the electric tire crane rotates to the right and the rotation speed is the second right-hand rotation speed.

[0023] In one embodiment, the master controller includes:

[0024] A first master controller; located on the first side of the control panel, used to input the up control signal and the down control signal;

[0025] The second master controller is located on the second side of the control panel and is used to input the left-hand control signal and the right-hand control signal.

[0026] In one embodiment, the first master controller is configured to have at least a first upshift, a second upshift, a first downshift, and a second downshift.

[0027] When the first master controller is switched to the first lifting position, the PLC outputs the corresponding lifting frequency conversion signal to the lifting frequency converter to control the lifting motor to operate, so that the hook of the electric tire crane rises and the lifting speed is the first lifting speed.

[0028] When the first master controller is switched to the second lifting position, the PLC outputs the corresponding lifting frequency conversion signal to the lifting frequency converter to control the lifting motor to operate, so that the hook of the electric tire crane rises and the lifting speed is the second lifting speed.

[0029] When the first master controller is switched to the first lowering position, the PLC outputs the corresponding lifting frequency conversion signal to the lifting frequency converter to control the lifting motor to operate, so that the hook of the electric tire crane is lowered and the lowering speed is the first lowering speed;

[0030] When the first master controller is switched to the second lowering position, the PLC outputs the corresponding lifting frequency conversion signal to the lifting frequency converter to control the lifting motor to operate, so that the hook of the electric tire crane lowers at the second lowering speed.

[0031] In one embodiment, the second master controller is configured to have at least a first left-hand rotation position, a second left-hand rotation position, a first right-hand rotation position, and a second right-hand rotation position;

[0032] When the second master controller is switched to the first left-hand rotation position, the PLC outputs the corresponding rotation frequency converter signal to the rotation frequency converter to control the rotation motor to operate, so that the boom of the electric tire crane rotates to the left and the rotation speed is the first left-hand rotation speed.

[0033] When the second master controller is switched to the second left-hand rotation position, the PLC outputs the corresponding rotation frequency converter signal to the rotation frequency converter to control the rotation motor to operate, so that the boom of the electric tire crane rotates to the left and the rotation speed is the second left-hand rotation speed;

[0034] When the second master controller is switched to the first right-hand rotation position, the PLC outputs the corresponding rotation frequency converter signal to the rotation frequency converter to control the rotation motor to operate, so that the boom of the electric tire crane rotates to the right and the rotation speed is the first right-hand rotation speed.

[0035] When the second master controller is switched to the second right-hand rotation position, the PLC outputs the corresponding rotation frequency converter signal to the rotation frequency converter to control the rotation motor to operate, so that the boom of the electric tire crane rotates to the right and the rotation speed is the second right-hand rotation speed.

[0036] In one embodiment, the control panel is further equipped with an amplification switch and a reduction switch. The amplification switch is used to input an amplification command, and the reduction switch is used to input a reduction command. Both the amplification switch and the reduction switch are electrically connected to the PLC. When the PLC receives the amplification command, it sends an amplification control signal to the luffing motor of the electric tire crane to make the electric tire crane increase its amplitude. When the PLC receives the reduction command, it sends a reduction control signal to the luffing motor of the electric tire crane to make the electric tire crane decrease its amplitude.

[0037] This application also provides an electric tire-mounted crane, including the control system described above.

[0038] The electric tire-mounted crane control system and the electric tire-mounted crane provided in this application are suitable for upgrading the wiring of old electric tire-mounted cranes. By controlling the working circuit of the motor through PLC, hoisting frequency converter and rotary frequency converter, the impact force on the motor is reduced, the service life of the equipment is extended, the workload of inspection and maintenance is reduced, and the reliability is improved. Furthermore, by combining the cam controller, master controller and PLC, two operation modes of the crane are realized. Loading and unloading drivers can choose the corresponding operation mode according to their job for training, which reduces training costs and meets the needs of green port energy conservation and low carbon initiatives. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is an architecture diagram of the control system of an electric tire crane in one embodiment;

[0041] Figure 2 This is an architecture diagram of the control system of an electric tire-mounted crane in another embodiment;

[0042] Figure 3 This is a schematic diagram of the control panel in one embodiment;

[0043] Figure 4 This is an electrical schematic diagram of an electric tire crane in one embodiment;

[0044] Figure 5 This is a wiring diagram of the PLC in one embodiment;

[0045] Figure 6This is a schematic diagram of the control program flow in one embodiment. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0047] It should be noted that the terms "first," "second," etc., used in this application can be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from the second element. The terms "comprising" and "having," and any variations thereof, used in this application, are intended to cover non-exclusive inclusion. The term "multiple" used in this application refers to two or more. The term "and / or" used in this application refers to one of the embodiments, or any combination of multiple embodiments.

[0048] Electric tire-mounted cranes are lifting devices that combine the mobility of tire travel with electric drive, and are widely used in ports, docks, and other locations requiring frequent relocation and lifting operations. An electric tire-mounted crane consists of two core modules: the upper structure and the lower structure. The upper structure contains the main working mechanisms and the operation control center, while the lower structure provides the traveling mobility and overall support stability during operation.

[0049] In some embodiments, the upper section includes a boom, a working mechanism, a cab, and a control system. The boom is the core load-bearing component, and the cab provides a working space for the operator. The working mechanism includes a hoisting mechanism and a slewing mechanism. The hoisting mechanism includes a hoisting motor and a hook for vertically lifting and lowering heavy objects; the slewing mechanism includes a rotary motor and a slewing bearing for driving the upper section to rotate relative to the lower section. In some embodiments, the working mechanism further includes a luffing mechanism for changing the boom's elevation angle, i.e., adjusting the radius of the electric tire crane.

[0050] The control system of electric tire cranes typically uses a cam controller, which utilizes the series or parallel connection of relay mechanical contacts to form control logic, directly controlling the working circuits of the motors in each working mechanism, thereby controlling the motor's starting, braking, and direction changes. However, using a cam controller to directly control the motor's working circuit puts a significant strain on the power grid. In practical applications, the wiring is numerous and complex, resulting in a large overall control system size and high power consumption. Furthermore, the mechanical contacts suffer from mechanical wear and arc burns during opening and closing, leading to short contact lifespans. Once the control system is configured, it is difficult to modify or add functions, and the failure rate is high, requiring substantial maintenance and repair costs, resulting in poor reliability and maintainability.

[0051] Marine cranes are lifting equipment installed on ship decks for cargo loading and unloading, equipment hoisting, supply operations, personnel transfer, and other special operations. Their design must withstand the harsh marine environment and strict safety regulations. Marine cranes use a master controller as the input device to meet the requirements of precise, smooth, and multi-degree-of-freedom coordinated control. Unlike cam controllers, master controllers output low-power electrical signals to various control elements, indirectly managing the motor's operating circuit through these elements, rather than directly controlling the motor's on / off state. Therefore, the operation methods and control circuits of marine cranes and electric tire-mounted cranes are completely different. Training loading and unloading drivers for different job types requires at least one electric tire-mounted crane and one marine crane, leading to a sharp increase in training costs.

[0052] Based on this, this application provides a control system for an electric tire-mounted crane, suitable for teaching and training, which can significantly reduce training and maintenance costs. Please refer to... Figure 1 , Figure 1 The diagram illustrates the architecture of a control system 100 for an electric tire-mounted crane in some embodiments of this application. The control system 100 provided in this application extends equipment lifespan, reduces maintenance costs, and improves the control system by configuring a PLC (Programmable Logic Controller), frequency converter, cam controller, and master controller. It also enables two crane control modes and enhances reliability.

[0053] Please see Figure 1 The control system 100 includes an operator console 1, a PLC 2, a hoisting frequency converter 3, and a rotary frequency converter 4. The operator console 1 is equipped with a cam controller 11 and a master controller 12. Both the cam controller 11 and the master controller 12 serve as input devices, used to input crane control signals, which can be coded signals. The PLC 2 is electrically connected to the cam controller 11 and the master controller 12 respectively, used to receive the crane control signals, process them, and output corresponding frequency converter control signals. Specifically, the crane control signals include an upward control signal, a downward control signal, a left-hand rotation control signal, and a right-hand rotation control signal. The upward control signal controls the hook of the electric tire crane to rise, the downward control signal controls the hook to fall, the left-hand rotation control signal controls the boom to rotate left, and the right-hand rotation control signal controls the boom to rotate right.

[0054] The frequency converter control signals include hoisting frequency converter control signals and rotation frequency converter control signals. The frequency converter control signals can be PWM signals output from PLC 2. Hoisting frequency converter 3 is electrically connected to PLC 2 and the hoisting motor 8 of the electric tire-mounted crane, and is used to control the hoisting motor according to the output hoisting frequency converter control signals to raise or lower the hook of the electric tire-mounted crane. Rotation frequency converter 4 is electrically connected to PLC 2 and the rotation motor 9 of the electric tire-mounted crane, and is used to control the rotation motor according to the rotation frequency converter control signals output from PLC 2 to rotate the boom of the electric tire-mounted crane left or right.

[0055] The control system 100 provided in this application controls the working circuit of the electric tire crane's motor through a PLC, a hoisting frequency converter, and a rotary frequency converter. This reduces the impact on the motor, extends the service life of the equipment, reduces the workload of inspection and maintenance, and improves reliability. By combining the cam controller, master controller, and PLC, two operating modes of the crane are realized. Loading and unloading drivers can choose the appropriate operating mode for training according to their job, reducing training costs and meeting the needs of green port energy conservation and low carbon initiatives. At the same time, the overall architecture is suitable for the circuit renovation of old electric tire cranes.

[0056] In one embodiment, refer to Figure 2 As shown, the control system 100 also includes a selector switch 13 located on the operator console 1. The selector switch 13 is configured to have a first mode and a second mode. When the selector switch 13 is in the first mode, the PLC 2 is electrically connected to the cam controller 11 to receive crane control signals input from the cam controller 11. When the selector switch 13 is in the second mode, the PLC 2 is electrically connected to the master controller 12 to receive crane control signals input from the master controller 12. The loading and unloading operator can select the corresponding mode by operating the selector switch 13, thus choosing to use either the cam controller 11 or the master controller 12 to operate the electric tire crane, enabling training in both modes. Furthermore, if one controller malfunctions, the other controller can be activated via the selector switch 13 to ensure the continuous operation of the control system 100.

[0057] In some embodiments, the changeover switch 13 may be a rotary switch, a toggle switch, a push-button switch, or a rocker switch.

[0058] In some embodiments, please refer to Figure 3As shown, the cam controller 11 includes a first cam controller 111 and a second cam controller 112. The first cam controller 111 is disposed on the first side of the operating table 1 and is used to input upward control signals and downward control signals; the second cam controller 112 is disposed on the second side of the operating table 1 and is used to input left-hand rotation control signals and right-hand rotation control signals. (Illustrative illustration) Figure 3 The first side is the left side, and the second side is the right side.

[0059] When it is necessary to control the lifting of the electric tire crane's hook to rise or fall, the operator can operate the first cam controller 111 located on the first side. For example, rotating the first cam controller 111 counterclockwise causes the hoisting motor to rotate forward, raising the hook of the electric tire crane; rotating the first cam controller 111 clockwise causes the hoisting motor to rotate in reverse, lowering the hook of the electric tire crane. When it is necessary to control the boom of the electric tire crane to rotate left or right, the operator can operate the second cam controller 112 located on the second side. For example, rotating the second cam controller 112 counterclockwise causes the rotary motor to rotate forward, rotating the boom of the electric tire crane to rotate left; rotating the second cam controller 112 clockwise causes the rotary motor to rotate in reverse, rotating the boom of the electric tire crane to rotate right.

[0060] In some embodiments, the first cam controller 111 is configured to have at least a first upward gear and a second upward gear along a first direction, and at least a first downward gear and a second downward gear along a second direction. The first cam controller 111 can implement multiple operating gears through cam group layout and contact system design. For example, when the rotation angle of the first cam controller 111 is 0°, the first cam controller 111 is in the zero position, at which time all contacts of the first cam controller are open. When the first cam controller 111 rotates to the first angle along the first direction, corresponding to the first upward gear SD1, contacts K1 and K2 of the first cam controller 111 are closed, and the first cam controller 111 outputs the encoded signal 0001. When the first cam controller 111 rotates to the second angle along the first direction, corresponding to the second upward gear SD2, an additional contact K3 is closed, that is, at this time contacts K1, K2, and K3 are all closed, and the first cam controller 111 outputs the encoded signal 0011. The gears corresponding to the second direction can be designed symmetrically with those of the first direction, and therefore will not be described in detail.

[0061] In some embodiments, when the first cam controller 111 rotates along the first direction to the first lifting position SD1, the PLC2 outputs a corresponding lifting frequency converter signal to the lifting frequency converter 3 to control the lifting motor 8 to operate, so that the hook of the electric tire crane rises, and the rising speed is a first rising speed VS1. When the first cam controller 111 rotates along the first direction to the second lifting position SD2, the PLC2 outputs a corresponding lifting frequency converter signal to the lifting frequency converter 3 to control the lifting motor 8 to operate, so that the hook of the electric tire crane rises, and the rising speed is a second rising speed VS2.

[0062] Indicatively, the first direction can be counterclockwise. When the first cam controller 111 rotates counterclockwise to the first angle (e.g., 30°, corresponding to the first rising gear SD1), the first cam controller 111 outputs an encoded signal 0001. The PLC2 receives the first encoded signal 0001 and outputs the corresponding PWM signal (corresponding to the lifting frequency converter signal) to the lifting frequency converter 3. The output frequency of the lifting frequency converter 3 is f1 (e.g., 20Hz), which controls the lifting motor 8 to rotate forward so that the hook of the electric tire crane rises at a first rising speed VS1. When the first cam controller 111 rotates counterclockwise to the second angle (e.g., 60°, corresponding to the second rising gear SD2), the first cam controller 111 outputs the encoded signal 0011. The PLC2 receives the second encoded signal 0011 and outputs the corresponding PWM signal to the hoisting frequency converter 3. The output frequency of the hoisting frequency converter 3 is f2 (e.g., 40Hz), which controls the hoisting motor 8 to rotate forward so that the hook of the electric tire crane rises at a first rising speed VS2.

[0063] In some embodiments, when the first cam controller 111 rotates in the second direction to the first lowering position XD1, the PLC2 outputs a corresponding hoisting frequency converter signal to the hoisting frequency converter 3 to control the hoisting motor 8 to operate, so that the hook of the electric tire crane lowers at a first lowering speed VX1. When the first cam controller 111 rotates in the second direction to the second lowering position XD2, the PLC2 outputs a corresponding hoisting frequency converter signal to the hoisting frequency converter 3 to control the hoisting motor 8 to operate, so that the hook of the electric tire crane lowers at a second lowering speed VX2.

[0064] Indicatively, the second direction is clockwise. When the first cam controller 111 rotates clockwise to the first angle (e.g., 30°, corresponding to the first descending gear XD1), the first cam controller 111 outputs an encoded signal 1110. The PLC2 receives the encoded signal 1110 and outputs the corresponding PWM signal (corresponding to the hoisting frequency converter signal) to the hoisting frequency converter 3. The output frequency of the hoisting frequency converter 3 is f1 (e.g., 20Hz), which controls the hoisting motor 8 to reverse, so that the hook of the electric tire crane descends at a first descending speed VX1. When the first cam controller 111 rotates clockwise to the second angle (e.g., 60°, corresponding to the second descent gear XD2), the first cam controller 111 outputs an encoded signal 1100. The PLC2 receives the encoded signal 1100 and outputs the corresponding PWM signal to the hoisting frequency converter 3. The output frequency of the hoisting frequency converter 3 is f2 (e.g., 40Hz), which controls the hoisting motor 8 to reverse, so that the hook of the electric tire crane descends at a first descent speed VX2.

[0065] In some embodiments, the second cam controller 112 is configured to have at least a first left-hand rotation position and a second left-hand rotation position along a first direction, and at least a first right-hand rotation position and a second right-hand rotation position along a second direction. The second cam controller 112 can also implement multiple operating positions through cam group layout and contact system design. Illustratively, when the rotation angle of the second cam controller 112 is 0°, the first cam controller 111 is in the zero position, and all contacts of the second cam controller are open. When the second cam controller 112 rotates to a first angle along the first direction, corresponding to the first left-hand rotation position ZD1, contacts K1 and K2 of the second cam controller 112 are closed, and the second cam controller 112 outputs the encoded signal 0001. When the second cam controller 112 rotates to a second angle along the first direction, corresponding to the second left-hand rotation position ZD2, an additional contact K3 is closed, meaning that at this time, contacts K1, K2, and K3 of the second cam controller 112 are all closed, and the second cam controller 112 outputs the encoded signal 0011. The gear positions for the second direction can be designed symmetrically with those for the first direction, so they will not be described in detail.

[0066] In some embodiments, when the second cam controller 112 rotates along the first direction to the first left-hand rotation position ZD1, the PLC2 outputs a corresponding rotation frequency converter signal to the rotation frequency converter 4 to control the rotation motor 9 to operate, so that the boom of the electric tire crane rotates to the left and the rotation speed is the first left-hand rotation speed VZ1. When the second cam controller 112 rotates along the first direction to the second left-hand rotation position ZD2, the PLC2 outputs a corresponding rotation frequency converter signal to the rotation frequency converter 4 to control the rotation motor 9 to operate, so that the boom of the electric tire crane rotates to the left and the rotation speed is the second left-hand rotation speed VZ2.

[0067] Indicatively, the first direction can be counterclockwise. When the second cam controller 112 rotates counterclockwise to the first angle (e.g., 30°, corresponding to the first left-hand rotation gear ZD1), the second cam controller 112 outputs an encoded signal 0001. The PLC2 receives the encoded signal 0001 output by the second cam controller 112 and outputs the corresponding PWM signal (corresponding to the rotary frequency converter signal) to the rotary frequency converter 4. At this time, the output frequency of the rotary frequency converter 4 is f1 (e.g., 20Hz), which controls the rotary motor 9 to rotate clockwise, so that the boom of the electric tire crane rotates counterclockwise and the counterclockwise rotation speed is the first counterclockwise rotation speed VZ1. When the second cam controller 112 rotates counterclockwise to the second angle (e.g., 60°, corresponding to the second left-hand rotation gear ZD2), the second cam controller 112 outputs the encoded signal 0011. The PLC2 receives the encoded signal 0011 output by the second cam controller 112 and outputs the corresponding PWM signal to the rotary inverter 4. At this time, the output frequency of the rotary inverter 4 is f2 (e.g., 20Hz), which controls the rotary motor 9 to rotate clockwise, so that the boom of the electric tire crane rotates to the left and the left rotation speed is the second left rotation speed VZ2.

[0068] In some embodiments, when the second cam controller 112 rotates in the second direction to the first right-hand rotation position YD1, the PLC2 outputs a corresponding rotation frequency converter signal to the rotation frequency converter 4 to control the rotation motor 9 to operate, so that the boom of the electric tire crane rotates to the right and the rotation speed is the first right-hand rotation speed VY1. When the second cam controller 112 rotates in the second direction to the second right-hand rotation position YD2, the PLC2 outputs a corresponding rotation frequency converter signal to the rotation frequency converter 4 to control the rotation motor 9 to operate, so that the boom of the electric tire crane rotates to the right and the rotation speed is the second right-hand rotation speed VY2.

[0069] Indicatively, the second direction can be clockwise. When the second cam controller 112 rotates clockwise to the first angle (e.g., 30°, corresponding to the first right-hand rotation gear YD1), the second cam controller 112 outputs an encoded signal 1110. The PLC2 receives the encoded signal 1110 output by the second cam controller 112 and outputs the corresponding PWM signal (corresponding to the rotary frequency converter signal) to the rotary frequency converter 4. At this time, the output frequency of the rotary frequency converter 4 is f1 (e.g., 20Hz), which controls the rotary motor 9 to reverse so that the boom of the electric tire crane rotates to the right and the right-hand rotation speed is the first left-hand rotation speed VY1. When the second cam controller 112 rotates clockwise to the second angle (e.g., 60°, corresponding to the second right-hand rotation position YD2), the second cam controller 112 outputs an encoded signal 1100. The PLC2 receives the encoded signal 1100 output by the second cam controller 112 and outputs the corresponding PWM signal (corresponding to the rotary frequency converter signal) to the rotary frequency converter 4. At this time, the output frequency of the rotary frequency converter 4 is f2 (e.g., 20Hz), which controls the rotary motor 9 to reverse so that the boom of the electric tire crane rotates to the right and the right rotation speed is the second left rotation speed VY2.

[0070] In some embodiments, see Figure 3 As shown, the master controller 12 includes a first master controller 121 and a second master controller 122. The first master controller 121 is located on the first side of the operator console 1 and is used to input upward control signals and downward control signals. The second master controller 122 is located on the second side of the operator console 1 and is used to input left-hand rotation control signals and right-hand rotation control signals.

[0071] The loading and unloading operator can select different master controllers on both sides of the control panel to achieve different control functions. When it is necessary to control the lifting of the electric tire crane hook, the operator can operate the first master controller 121 located on the first side. For example, when the first master controller 121 is moved upward, the lifting motor 8 rotates forward, and the hook of the electric tire crane rises; when the first master controller 121 is moved downward, the lifting motor 8 rotates in reverse, and the hook of the electric tire crane lowers. When it is necessary to control the boom of the electric tire crane to rotate left or right, the operator can operate the second master controller 122 located on the second side. For example, when the second master controller 122 is moved to the left, the rotary motor rotates forward, and the boom of the electric tire crane rotates left; when the second master controller 122 is moved to the right, the rotary motor rotates in reverse, and the boom of the electric tire crane rotates right.

[0072] In some embodiments, the first master controller 121 is configured to have at least a first upshift, a second upshift, a first downshift, and a second downshift.

[0073] When the first master controller 121 is switched to the first ascending position, PLC2 outputs a corresponding hoisting frequency converter signal to the hoisting frequency converter 3, controlling the hoisting motor 8 to operate, so that the hook of the electric tire crane rises at a first ascending speed. When the first master controller 121 is switched to the second ascending position, PLC2 outputs a corresponding hoisting frequency converter signal to the hoisting frequency converter 3, controlling the hoisting motor 8 to operate, so that the hook of the electric tire crane rises at a second ascending speed. When the first master controller 121 is switched to the first descending position, PLC2 outputs a corresponding hoisting frequency converter signal to the hoisting frequency converter 3, controlling the hoisting motor 8 to operate, so that the hook of the electric tire crane descends at a first descending speed. When the first master controller 121 is switched to the second descending position, PLC2 outputs a corresponding hoisting frequency converter signal to the hoisting frequency converter 3, controlling the hoisting motor 8 to operate, so that the hook of the electric tire crane descends at a second descending speed.

[0074] In some embodiments, the first master controller 121 may be a cross switch, which includes a cross handle, a camshaft assembly, and a contact assembly. When the cross handle is rotated, it drives the cam plate in the camshaft assembly to rotate, thereby controlling multiple sets of contacts in the contact assembly to be turned on and off in sequence, thereby forming various control commands.

[0075] In some embodiments, the second master controller 122 is configured to have at least a first left-hand rotation position, a second left-hand rotation position, a first right-hand rotation position, and a second right-hand rotation position.

[0076] When the second master controller 122 is switched to the first left-hand rotation position, the PLC outputs a corresponding rotary frequency converter signal to the rotary frequency converter 4, controlling the rotary motor 9 to operate, so that the boom of the electric tire crane rotates to the left and the rotation speed is the first left-hand rotation speed. When the second master controller 122 is switched to the second left-hand rotation position, the PLC2 outputs a corresponding rotary frequency converter signal to the rotary frequency converter 4, controlling the rotary motor 9 to operate, so that the boom of the electric tire crane rotates to the left and the rotation speed is the second left-hand rotation speed.

[0077] When the second master controller 122 is switched to the first right-hand rotation position, PLC2 outputs a corresponding rotary frequency converter signal to the rotary frequency converter 4, controlling the rotary motor 9 to operate, so that the boom of the electric tire crane rotates to the right at the first right-hand rotation speed. When the second master controller 122 is switched to the second right-hand rotation position, PLC2 outputs a corresponding rotary frequency converter signal to the rotary frequency converter 4, controlling the rotary motor 9 to operate, so that the boom of the electric tire crane rotates to the right at the second right-hand rotation speed.

[0078] In some embodiments, the second master controller 122 may also be a cross switch.

[0079] In some embodiments, still refer to Figure 2 As shown, the control panel 1 is also equipped with an amplification switch 14 and a reduction switch 15. The amplification switch 14 is used to input amplification commands, and the reduction switch 15 is used to input reduction commands. Both the amplification switch 14 and the reduction switch 15 are electrically connected to the PLC2. When the PLC2 receives an amplification command, it sends an amplification control signal to the luffing motor 7 of the electric tire crane to increase the amplification of the crane and increase the boom's elevation angle. When the PLC receives a reduction command, it sends a reduction control signal to the luffing motor 7 of the electric tire crane to decrease the amplification of the crane and reduce the boom's elevation angle. In one embodiment, both the amplification switch 14 and the reduction switch 15 can be push-button switches.

[0080] Figure 4 This is an electrical schematic diagram of an electric tire-mounted crane in one embodiment. Please refer to [link / reference]. Figure 4 As shown, Figure 4 The left side is the main circuit section. L1, L2, and L3 introduce a three-phase 380V power supply, which, via circuit breaker QF, the main contacts of power contactor KM, and then fuses FU1 and FU2, provides power to the hoisting and rotating frequency converters. Each frequency converter's R, S, and T ports are connected to the input power, while U, V, and W are the output ports, connected to the three-phase motor. Motor speed is adjusted by changing the output frequency. PE is the motor ground, ensuring personnel safety in case of leakage. The hoisting frequency converter drives the hoisting motor of the electric tire crane, and the rotating frequency converter drives the rotating motor of the electric tire crane, respectively achieving speed control for hoisting and rotating movements.

[0081] Figure 4 The right side is the control circuit section, supplied with a 36V safety voltage by the control transformer TC. SB1 is the power-on switch; SQ1 is the cab door limit switch, normally closed, and activated when the cab door is closed; SB is the emergency stop button switch, normally closed; SB2 is the power-off switch, normally closed; KM is the power contactor. When SB1 is pressed, SB, SB2, and SQ1 in the control circuit must be closed, energizing the KM coil, closing the KM main contacts, and connecting the main circuit power to the inverter; simultaneously, the KM auxiliary contacts self-lock, maintaining KM's engagement, and power supply remains even after SB1 is released. Pressing SB2 de-energizes the KM coil, cutting off the main circuit power and stopping the equipment's power supply; pressing the emergency stop button SB also cuts off the KM coil circuit, causing an emergency power outage.

[0082] SA1 is the hoisting speed switch. SA1-1 is the first hoisting speed, and SA1-2 is the second hoisting speed. When SA1-1 and SA1-2 are connected, the corresponding KA1 and KA2 relay coil circuits (requiring the KM auxiliary contact to be closed and the power supply to be enabled) output the KA1 or KA2 contact to the control terminals of the hoisting inverter, such as STR and STF, changing the inverter's output frequency to achieve speed switching of the hoisting motor. This allows the hoisting speed of the hook to switch between the first and second hoisting speeds. SA3 is the hoisting direction switching switch. SA3-1 indicates the cam is rising, and SA3-2 indicates the cam is falling. When SA3-1 and SA3-2 are connected, the KA2 and KA1 relay coil circuits control the hoisting inverter's forward and reverse rotation commands through the contacts, driving the motor to rotate forward or in reverse.

[0083] SQ2 and SQ3 are normally closed limit switches. SQ2 is the upper limit switch for hoisting, and SQ3 is the lower limit switch for hoisting. When the corresponding limit switch is touched during hoisting, the corresponding circuit is disconnected, the KA1 or KA2 coil is de-energized, the control signal of the hoisting frequency converter is cut off, and the motor stops running to prevent over-travel during hoisting.

[0084] SA2 is a rotation speed switching switch. SA2-1 represents the first rotation speed, and SA2-2 represents the second rotation speed. When SA2-1 and SA2-2 are connected, the corresponding relay coil circuits KA3 and KA4 are activated. The KA3 and KA4 contacts output to the control terminals of the rotary inverter, such as STR and STF, changing the inverter's output frequency and thus switching the rotation speed of the rotary motor. This allows control of the boom's rotation speed between the first and second rotation speeds. SA4 is a rotation direction switching switch. SA4-1 indicates the cam is rotating left, and SA4-2 indicates the cam is rotating right. When SA4-1 and SA4-2 are connected, the relay coil circuits KA4 and KA3 control the rotary inverter's forward and reverse rotation commands through their contacts, driving the motor to rotate forward or reverse, thereby controlling the boom's left or right rotation.

[0085] SQ4 and SQ5 are normally closed limit switches. SQ4 is a left-hand limit switch and SQ5 is a right-hand limit switch. When the boom rotates and touches the limit switch, the corresponding circuit is disconnected, the coils of KA3 and KA4 are de-energized, the control signal of the rotary inverter is cut off, and the rotary motor stops running to prevent overtravel.

[0086] It can be seen that the above control circuit realizes the logic of motor forward rotation, reverse rotation, and multi-speed, and the relays and switches have interlocking functions to avoid malfunctions.

[0087] Figure 5This is a wiring diagram of a PLC in one embodiment. A PLC operates by monitoring input signals and providing output signals. When upgrading the circuitry of an older electric tire-mounted crane, the PLC model and specifications can be selected based on the function and quantity of the original system's input and output signals, combined with the upgrade requirements. (Illustrative example) Figure 5 The PLC shown requires 38 I / O ports. The table below shows the PLC's I / O allocation.

[0088]

[0089] Reference Figure 5 As shown in the table above, in this embodiment, the PLC serves as the core control unit, replacing the traditional pure relay logic. The operation of external components (such as emergency stop button switches, limit switches, related operations of master controllers or cam controllers) and detection signals are all sent to the PLC input port (X port). After the PLC performs internal program calculations, it drives the inverter, contactor, indicator lights and other loads through the output port (Y port).

[0090] To illustrate, when an external component is closed, the PLC input port is energized, and the PLC detects a "1" signal; when it is opened, the input port is de-energized, and the PLC detects a "0" signal.

[0091] In this embodiment, the PLC input ports can be divided into 5 categories according to signal type, and the corresponding wiring logic is explained in detail below.

[0092] 1. Power control input ports

[0093] I / O address X0 corresponds to emergency stop button switch SB. When emergency stop button switch SB is not pressed, the contacts are closed, and X0 is energized (PLC detects 1). When emergency stop button switch SB is pressed, the contacts are opened, X0 is de-energized (PLC detects 0), and PLC immediately triggers the overall shutdown program, resetting all outputs to the highest level of safety signal.

[0094] I / O address X1 corresponds to power disconnect switch SB2. When power disconnect switch SB2 is not pressed, it is closed and X1 is energized; when pressed, it is open and X1 is de-energized. After receiving the PLC, it cuts off the power contactor KM (Y14) and all frequency converter commands.

[0095] I / O address X2 corresponds to the cab door limit switch SQ1. When the cab door is closed, X2 is energized; when the cab door is open, X2 is de-energized, and the PLC locks the power supply. Therefore, KM cannot be started if the cab door is not closed, which is a safety interlock signal.

[0096] I / O address X7 corresponds to the power switch SB1. When pressed, it closes and X7 is energized (the PLC detects 1); when released, it opens and X7 is de-energized, which is the core operation signal for the PLC to start the power contactor KM.

[0097] In addition, the PLC internal program will only respond to the power-on command of X7 when X0, X1, and X2 are all 1; otherwise, it will refuse to start. This interlocking mechanism ensures the safety of power-on from the data acquisition end.

[0098] 2. Lifting control input ports

[0099] The hoisting control input ports correspond to the crane's hoisting mechanism and consist of the contacts of the cam controller (SA1, SA3) and the hoisting limit switches (SQ2, SQ3). The direction and speed contacts are wired independently, and the limit switches are for safety interlocking. When a master controller is used for control, SA1 and SA3 correspond to the respective contacts of the master controller. The following example uses only the cam controller.

[0100] Directional contacts: SA3-1 (X24, cam ascender) and SA3-2 (X25, cam descender) are normally open contacts. When the cam controller rotates to the ascending or descending position, the corresponding contacts close, and the PL acquires the directional signal.

[0101] Speed ​​contacts: SA1-1~SA1-6 (X10~X15) are normally open contacts, corresponding to 3-speed upward and 3-speed downward. When the cam controller is in the upward or downward speed position, it rotates to the corresponding upward or downward speed position, and the corresponding speed contact closes, and the PLC collects the speed signal.

[0102] Limit contacts: SQ2 (X3, upper limit of lifting) and SQ3 (X4, lower limit of lifting) are normally closed contacts. When the lifting exceeds the travel limit, the contacts open. When the PLC detects a 0 signal, it immediately cuts off the inverter command in the lifting direction to achieve hard interlock protection.

[0103] The direction and speed contacts are independently connected to the corresponding input ports of the PLC, without interfering with each other. The PLC program matches the direction and speed, and can also interlock in opposite directions. For example, when X24 is 1, X25 is locked to 0 to ensure operational safety.

[0104] 3. Rotary control input ports

[0105] The rotation control input port corresponds to the crane's rotation mechanism. Rotation control is implemented by SA2 and SA4, and the wiring logic is consistent with the hoisting control, including direction contacts and speed contacts.

[0106] Direction contacts: SA4-1 (X26, left turn) and SA4-2 (X27, right turn) normally open contacts. When the corresponding position is closed, the PLC will collect the corresponding direction signal.

[0107] Speed ​​contacts: SA2-1~SA2-6 (X16~X23) normally open contacts, corresponding to 3 left-hand rotation speed and 3 right-hand rotation speed. When the corresponding speed is closed, the PLC will collect the corresponding speed signal.

[0108] 4. Amplitude control input ports

[0109] The luffing control input ports correspond to the luffing mechanism of the crane, enabling the limit function of the luffing mechanism. Among them, SQ4 (X5, increasing luffing) and SQ5 (X6, decreasing luffing) are normally closed contacts, which open when the luffing exceeds the travel limit, and the PLC immediately cuts off the luffing-related commands.

[0110] 5. Mode switching input port

[0111] I / O address X30 corresponds to control mode switching SA5. In this embodiment, a two-position selector switch can be used. When the switch is turned to the corresponding position, the contact closes, the PLC collects a 1 signal, and switches to electric tire mode or marine crane mode. The internal program matches different control logic, corresponding to the operation mode of the cam controller or the master controller.

[0112] PLC output ports are instruction output terminals that convert the results of internal program calculations into electrical signals to drive external loads. Illustratively, a PLC output of 1 energizes the port and activates the load; an output of 0 de-energizes the port and resets the load. In this embodiment, PLC output ports can be divided into three categories according to load type, and the corresponding wiring logic and control principles are explained in detail below.

[0113] 1. Variable frequency drive control output ports

[0114] In this embodiment, there are two frequency converters. Frequency converter 1# is a hoisting frequency converter used to drive the hoisting mechanism (Y0~Y3), and frequency converter 2# is a rotary frequency converter used to drive the rotary mechanism (Y4~Y7). S1 / S2 / S5 / S6 of each frequency converter are switch command terminals, and the PLC output is directly connected to the corresponding command terminal.

[0115] Indicatively, when the PLC detects X24 (ascending direction) as 1, Y0 outputs 1, sending an ascending direction command to inverter #1; when the PLC detects X25 (descending direction) as 1, Y1 outputs 1, sending a descending direction command to inverter #1; when the PLC detects the high-speed hoisting signal (X12 / X11) as 1, Y2 outputs 1, and inverter #1 switches to high speed; when the PLC detects the low-speed hoisting signal (X10) as 1, Y3 outputs 1, and inverter #1 switches to low speed; when the PLC detects X26 (left-hand rotation) as 1, Y4 outputs 1, sending a left-hand rotation command to inverter #2; when the PLC detects X27 (right-hand rotation) as 1, Y5 outputs 1, sending a right-hand rotation command to inverter #2; when the PLC detects the high-speed rotation signal (X20 / X17) as 1... When Y6 outputs 1, inverter #2 switches to high speed; when the PLC detects that the low speed rotation signal (X16) is 1, Y7 outputs 1, and inverter #2 switches to low speed.

[0116] The direction commands (Y0 / Y1, Y4 / Y5) and speed commands (Y2 / Y3, Y6 / Y7) are output independently. The inverter works with the PLC commands to achieve combined control of direction and speed. The PLC program can also strictly implement interlocking of outputs in opposite directions. For example, if Y0 is 1, Y1 is locked to 0, and if Y4 is 1, Y5 is locked to 0, to prevent the inverter from receiving the opposite direction command and causing a fault.

[0117] 2. Contactor drive output ports

[0118] I / O address Y14 corresponds to power contactor KM. When the PLC determines that X0 / X1 / X2 is 1 and X7 is also 1, Y14 outputs 1, KM is energized, and the main circuit supplies power to the frequency converter. When any safety signal is de-energized (X0 / X1 / X2 is 0), Y14 immediately resets, KM is de-energized, and the main power supply is cut off.

[0119] 3. Indicator light output ports

[0120] In this embodiment, HL1, HL2, HL3, and HL4 are all status indicator lights, which can be directly driven by the PLC output. They are connected to the corresponding power supply; when the PLC outputs 1, the light illuminates, and when it outputs 0, the light goes out, providing visual feedback on the equipment status. Specifically, Y10 corresponds to HL1. When Y14 (KM) is 1, Y10 outputs 1 synchronously, and HL1 illuminates, indicating that the main power supply is on. Y11 corresponds to HL2. When the PLC detects an emergency stop (X0 is 0), limit overtravel (X3 / X4 / X5 / X6 are 0), or inverter fault (if a signal is input), Y11 outputs 1, and HL2 illuminates, indicating a equipment fault. Y12 corresponds to HL3 and is used to indicate the electric tire mode. When SA5 (X30) switches to this mode, and the PLC detects X30 as 1, Y12 outputs 1, and HL3 illuminates. Y13 corresponds to HL4 and is used to indicate the marine crane mode. When SA5 (X30) switches to this mode, the PLC detects that X30 is 0, Y13 outputs 1, and HL4 lights up.

[0121] Figure 6 This is a schematic diagram of the control program flow in one embodiment. By modularly writing the control program, control of various parts of the electric tire crane can be achieved, including power supply, hoisting, luffing, rotation, and travel, while also facilitating maintenance. It should be noted that, for ease of description, Figure 6 The document simplifies some component names and operating procedures. For example, Figure 6 The "cam mechanism" mentioned above refers to a cam controller, while the "cross switch" is a type of master controller. Therefore, Figure 6 The simplified description in this application should not limit the scope of protection of this application.

[0122] In one embodiment, the hoisting motor 8 is a variable frequency motor, the rotary motor 9 is a wound-rotor motor, and the rotor winding tap terminals of the wound-rotor motor are short-circuited.

[0123] Although wound-rotor motors and variable frequency motors (VFM) are both AC asynchronous motors, they typically differ fundamentally in their design intent, core structure, speed control method, and applicable scenarios. Wound-rotor motors primarily improve starting performance and achieve speed control by altering rotor circuit parameters, while VFM motors are specifically designed to work with frequency converters to achieve wide-range, efficient speed control. The rotor windings of wound-rotor motors are made of copper wire, with the winding ends connected to slip rings on the shaft and to external resistors or other devices via brushes. Therefore, their structure includes slip rings and brushes, two easily worn components. VFM motors, on the other hand, often employ a squirrel-cage rotor structure, consisting of copper or aluminum bars short-circuited with end rings. This design is simple, robust, and eliminates slip rings and brushes.

[0124] This embodiment fully considers the characteristics of different motors and their adaptability in various mechanisms when using frequency converter speed regulation. The core of the crane is the hoisting mechanism, which is a potential energy load, requiring the system to have good dynamic performance to ensure smooth, safe, and reliable lifting of goods. During the retrofitting of electric tire cranes, continuing to use the original wound-rotor motor for frequency conversion speed regulation would be insufficient to meet the above performance requirements. Therefore, this embodiment replaces the hoisting motor with a high-performance dedicated frequency converter motor, for example, a 132kW dedicated frequency converter motor, adapted to a D700 frequency converter.

[0125] For rotating mechanisms, traditional electric tire-mounted cranes typically use wound-rotor motors (e.g., a 22kW wound-rotor motor). To adapt it to a rotary frequency converter, this embodiment short-circuit the rotor winding tap terminals of the wound-rotor motor. In standard wound-rotor motor operation, the rotor winding is connected in series with an external resistor via slip rings and brushes; in this embodiment, by short-circuiting the rotor winding tap terminals, the external resistor is effectively removed, leaving only the rotor winding's own resistance. At this point, the rotor circuit structure of the wound-rotor motor is physically equivalent to the rotor structure of a squirrel-cage induction motor, and electrically transformed into a squirrel-cage motor with relatively high rotor resistance. This satisfies the requirements of frequency conversion speed regulation while effectively saving on crane modification costs.

[0126] In one embodiment, an electric tire-mounted crane is also provided, including the aforementioned control system. This electric tire-mounted crane controls the motor's operating circuit via a PLC, a hoisting frequency converter, and a rotation frequency converter, reducing the impact on the motor, extending the equipment's service life, reducing maintenance workload, and improving reliability. Furthermore, the combination of a cam controller, a master controller, and a PLC enables two crane operation modes, allowing loading and unloading drivers to choose the appropriate mode for their job during training, thus reducing training costs.

[0127] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0128] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A control system for an electric tyre crane, characterised in that The utility model relates to a kind of crane control system, including: Operation platform, the operation platform is equipped with cam controller and master controller, the cam controller and the master controller are used to input crane control signal, the crane control signal includes ascending control signal, descending control signal, left rotation control signal and right rotation control signal; PLC, respectively electrically connected the cam controller and the master controller, for receiving the crane control signal, and the crane control signal is handled, corresponding frequency converter control signal is output, the frequency converter control signal includes hoisting frequency converter control signal and rotating frequency converter control signal; Hoisting frequency converter, electrically connected the PLC and the hoisting motor of electrically-driven rubber-tired crane, for according to the hoisting frequency converter control signal that the PLC outputs hoisting motor is controlled, to make the hook of the electrically-driven rubber-tired crane ascend or descend; Rotating frequency converter, electrically connected the PLC and the rotating motor of the electrically-driven rubber-tired crane, for according to the rotating frequency converter control signal that the PLC outputs rotating motor is controlled, to make the boom of the electrically-driven rubber-tired crane left rotation or right rotation.

2. The control system of claim 1, wherein, Further including switch-over switch arranged in the operation platform, the switch-over switch is configured to have first mode and second mode;When switch-over switch is placed in first mode, the PLC is electrically connected with the cam controller, for receiving the crane control signal that the cam controller input;When switch-over switch is placed in second mode, the PLC is electrically connected with the master controller, for receiving the crane control signal that the master controller input.

3. The control system of claim 1 or 2, wherein, The cam controller includes: First cam controller, arranged in the first side of the operation platform, for input the ascending control signal and the descending control signal; Second cam controller, arranged in the second side of the operation platform, for input the left rotation control signal and the right rotation control signal.

4. The control system of claim 3, wherein, The first cam controller is configured to have at least first ascending gear and second ascending gear along first direction, have at least first descending gear and second descending gear along second direction; When the first cam controller rotates to first ascending gear along the first direction, the PLC outputs corresponding hoisting frequency signal to the hoisting frequency converter, controls the hoisting motor to run, to make the hook of the electrically-driven rubber-tired crane ascend and ascending speed is first ascending speed; When the first cam controller rotates to second ascending gear along the first direction, the PLC outputs corresponding hoisting frequency signal to the hoisting frequency converter, controls the hoisting motor to run, to make the hook of the electrically-driven rubber-tired crane ascend and ascending speed is second ascending speed; When the first cam controller rotates to the first descending gear along the second direction, the PLC outputs corresponding hoisting frequency signal to the hoisting frequency converter, controls the hoisting motor to run, to make the hook of the electrically-driven rubber-tired crane descend and descending speed is first descending speed; When the first cam controller rotates to the second descending gear along the second direction, the PLC outputs corresponding hoisting frequency signal to the hoisting frequency converter, controls the hoisting motor to run, to make the hook of the electrically-driven rubber-tired crane descend and descending speed is second descending speed. When the first cam controller rotates to the second lowering position along the second direction, the PLC outputs a corresponding lifting frequency converter signal to the lifting frequency converter to control the lifting motor to operate, so that the hook of the electric tire crane lowers at the second lowering speed.

5. The control system of claim 3, wherein, The second cam controller is configured to have at least a first left-hand rotation position and a second left-hand rotation position in a first direction, and at least a first right-hand rotation position and a second right-hand rotation position in a second direction; When the second cam controller rotates to the first left-hand rotation position along the first direction, the PLC outputs a corresponding rotation frequency converter signal to the rotation frequency converter to control the rotation motor to operate, so that the boom of the electric tire crane rotates to the left and the rotation speed is the first left-hand rotation speed; When the second cam controller rotates to the second left-hand rotation position along the first direction, the PLC outputs a corresponding rotation frequency converter signal to the rotation frequency converter to control the rotation motor to operate, so that the boom of the electric tire crane rotates to the left and the rotation speed is the second left-hand rotation speed; When the second cam controller rotates to the first right-hand rotation position along the second direction, the PLC outputs a corresponding rotation frequency converter signal to the rotation frequency converter to control the rotation motor to operate, so that the boom of the electric tire crane rotates to the right and the rotation speed is the first right-hand rotation speed; When the second cam controller rotates to the second right-hand rotation position along the second direction, the PLC outputs a corresponding rotation frequency converter signal to the rotation frequency converter to control the rotation motor to operate, so that the boom of the electric tire crane rotates to the right and the rotation speed is the second right-hand rotation speed.

6. The control system of claim 1 or 2, wherein, The master controller includes: A first master controller; located on the first side of the control panel, used to input the up control signal and the down control signal; The second master controller is located on the second side of the control panel and is used to input the left-hand control signal and the right-hand control signal.

7. The control system of claim 6, wherein, The first master controller is configured to have at least a first up gear, a second up gear, a first down gear, and a second down gear; When the first master controller is switched to the first lifting position, the PLC outputs the corresponding lifting frequency conversion signal to the lifting frequency converter to control the lifting motor to operate, so that the hook of the electric tire crane rises and the lifting speed is the first lifting speed. When the first master controller is switched to the second lifting position, the PLC outputs the corresponding lifting frequency conversion signal to the lifting frequency converter to control the lifting motor to operate, so that the hook of the electric tire crane rises and the lifting speed is the second lifting speed. When the first master controller is switched to the first lowering position, the PLC outputs the corresponding lifting frequency conversion signal to the lifting frequency converter to control the lifting motor to operate, so that the hook of the electric tire crane is lowered and the lowering speed is the first lowering speed; When the first master controller is switched to the second lowering position, the PLC outputs the corresponding lifting frequency conversion signal to the lifting frequency converter to control the lifting motor to operate, so that the hook of the electric tire crane lowers at the second lowering speed.

8. The control system of claim 6, wherein, The second master controller is configured to have at least a first left-hand rotation position, a second left-hand rotation position, a first right-hand rotation position, and a second right-hand rotation position; When the second master controller is switched to the first left-hand rotation position, the PLC outputs the corresponding rotation frequency converter signal to the rotation frequency converter to control the rotation motor to operate, so that the boom of the electric tire crane rotates to the left and the rotation speed is the first left-hand rotation speed. When the second master controller is switched to the second left-hand rotation position, the PLC outputs the corresponding rotation frequency converter signal to the rotation frequency converter to control the rotation motor to operate, so that the boom of the electric tire crane rotates to the left and the rotation speed is the second left-hand rotation speed; When the second master controller is switched to the first right-hand rotation position, the PLC outputs the corresponding rotation frequency converter signal to the rotation frequency converter to control the rotation motor to operate, so that the boom of the electric tire crane rotates to the right and the rotation speed is the first right-hand rotation speed. When the second master controller is switched to the second right-hand rotation position, the PLC outputs the corresponding rotation frequency converter signal to the rotation frequency converter to control the rotation motor to operate, so that the boom of the electric tire crane rotates to the right and the rotation speed is the second right-hand rotation speed.

9. The control system of claim 1, wherein, The control panel is also equipped with an amplification switch and a reduction switch. The amplification switch is used to input an amplification command, and the reduction switch is used to input a reduction command. Both the amplification switch and the reduction switch are electrically connected to the PLC. When the PLC receives the amplification command, it sends an amplification control signal to the luffing motor of the electric tire crane to make the electric tire crane increase its amplitude. When the PLC receives the reduction command, it sends a reduction control signal to the luffing motor of the electric tire crane to make the electric tire crane decrease its amplitude.

10. An electric tyre crane, characterized in that The control system includes any one of claims 1-9.

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