Safe operation and use of wireless remote control

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Safe operation of crane wireless remote control

now cranes widely use wireless remote control. The use of remote control has the characteristics of improving working conditions and convenient operation. Especially in some slate production enterprises, wireless remote control operation mode is widely used, which avoids the driver's personal accidents that may be caused by crane derailment or heavy objects falling. However, when using wireless remote control, it is different from the traditional cable manual controller in terms of safe use

I. safety requirements for wireless remote control of cranes

1. Cranes using wireless remote control should have various reports of the original crane to make more perfect requirements for the protection of the car interior in terms of aesthetics, safety and charm, such as zero position, overcurrent, travel and other protection. When the remote control adopts a non automatic reset joystick, it is required that all joysticks should be in the zero position before operation, and then the control command can be issued. When the master controller and contactor are under control, the remote controller can connect the main power circuit of the crane only when the master controller must be in the zero position. When the crane is accidentally powered off, the remote control should stop working. When the power supply is restored, the remote controller must pass the correct starting procedure to connect the main power circuit of the crane. When the power supply voltage of the remote controller is insufficient, it should be able to send a stop command through the white control function. The top three export markets are Hong Kong, China, the United States and Vietnam

2. The crane with wireless remote control should be equipped with a main contactor or an air circuit breaker with voltage loss trip to cut off the main power supply of the crane. The power supply of all mechanisms must be led out from the outlet end of the main power contactor. The action of the main power contactor or the circuit breaker with voltage loss tripping line shall be able to cut off the main power supply of all mechanisms and stop the operation of all mechanisms

3. For cranes with wireless remote control, there should be an obvious remote control indicator light on the crane, indicating that the machine is operated with a remote controller

4. When a crane is operated by both remote control and cab, interlocking shall be realized between them. The change-over switch must be set at the population of the cab

5. Relays and contactors in forward and reverse operation shall have electrical interlocking. When necessary, contactors can be added with mechanical interlocking, and the forward and reverse operation codes of the motion mechanism in the receiving processor shall have software interlocking

6. The radio remote control system should have the ability to resist the same frequency interference signal, and no misoperation is allowed when it is interfered by the same frequency. The control receiver is directly connected with the strong current system. There will be many kinds of interference, so its reliability and anti-interference are very important, which is the basis for the system to be put into operation. The output of the system is to drive the relay and contactor to control the motor operation, so weak current and strong current systems must be isolated. Because the interference in the industrial field is too large, pulse interference often occurs. Therefore, attention should be paid to the selection of the receiver chip at the control end. The receiving sensor is connected to the receiver host with cable rope, and the cable shall have good shielding function. The receiving sensor shall be able to work normally when the illumination of sunlight is 80001x and the light is 20001x. When the distance from the welding arc is greater than 6m, it can refuse to act and give an alarm or passive emergency stop, but there is no error action

7. The receiver shell and intermediate relay box shall be reliably connected with the crane steel structure

8. Safety requirements for emergency stop function of wireless remote control device. The emergency stop function includes active emergency stop and passive emergency stop. Active emergency stop means that the driver sends an emergency stop command through the transmitter to cut off the main power supply on the crane. The product standard for stopping lifting shall specify the sample size to be reduced and the corresponding processing method, and the movements of various mechanisms of the crane. Passive emergency stop means that when the receiver fails to detect the normal signal within a certain period of time or the receiver (control system) fails, it can cut off the channel power supply and stop the operation of each mechanism of the crane. First, consider whether the installation of the main body of the experimental machine is vertical. In order to prevent maloperation, the active emergency stop switch should not be reset automatically. The driver sends the active emergency stop command through the transmitter until the control end of the intermediate relay of the receiver outputs the active emergency stop command. The time required should be less than 0.5s. This command cuts off the main power supply and is the highest priority. When the high-frequency carrier wave cannot be detected or the data signal cannot be received, the passive emergency stop function shall be realized, and the total power supply of the channel must be cut off within 1.5s. When the sudden noise interference of the channel exceeds LS or the correct address code cannot be detected in LS, the channel power supply shall be cut off

II. Composition of transmitter and control receiver

now, the composition block diagram of transmitter and controller of a low-power wireless remote control device is given to illustrate its working principle. The device directly adopts the wireless data transmission module hac-up24 of Shenzhen Huaao Communication Technology Co., Ltd., which is based on the modulation method of FSK. The composition block diagram is shown in Figure 1 and Figure 2 respectively

when the key on the remote control is pressed. Through the 80C51 on the transmitter, the data bits and coded address bits corresponding to the keys are converted into serial digital coded pulse signals. Through the hac-up24 data module, the pulse signals are converted into high-frequency amplitude modulated radio signals to radiate electromagnetic waves into the air

the receiver at the control end converts the received electromagnetic wave into pulse signal through the data transmission module. After amplification, mixing and detection. Filter out the interference signal. Output the correct pulse signal for control operation

due to the sliding of traveling crane and electric hoist. The actual power supply will have instantaneous power failure. And because the power supply on the industrial site is not ideal, pulse interference often occurs on the industrial site. In actual use. For the purchased wireless remote control products, we should check whether there is a circuit design to design anti-interference signals of the same frequency in the electrical schematic diagram

III. conclusion

it can be seen from the above introduction. The wireless remote control crane can meet various production environments. Pay attention to the safety of use. Compared with using cable manual operation, it can reduce the labor force. Saving time. Improve production efficiency and avoid personal injury and equipment loss caused by misoperation

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