Garbage crane control system with automatic weighing function

Abstract

The invention discloses a garbage crane control system with an automatic weighing function. The garbage crane control system comprises a current sensor, an adjusting circuit, an ADC module, a current conversion module and a PLC module. The current sensor, the adjusting circuit and the ADC module are arranged in the traveling mechanism, and the PLC module is arranged in a power distribution control room of the garbage crane; the current sensor is used for acquiring the current of a motor in the vehicle lifting frequency converter and transmitting the current to the adjusting circuit, the adjusting circuit is used for converting the current into a voltage signal, the ADC module is used for converting the voltage signal into a digital signal, the current conversion module is used for converting the digital signal into a current signal, and the current conversion module is used for outputting the current signal. The PLC module collects the current signal output by the current conversion module and calculates the garbage weight according to the current signal. The method is more beneficial to benefit accounting and parameter regulation and control of the power plant.

Description

Technical Field

[0001] The invention belongs to the technical field of garbage cranes, and in particular relates to a garbage crane control system with an automatic weighing function. Background Art

[0002] The amount of energy generated per ton of garbage is a key indicator for refined management, and the accuracy of garbage weight in the grab bucket of a garbage crane is a key factor influencing this. Since garbage crane weighing systems generally utilize traditional sensor transmission, there are many different sensor installation methods, all working in the same principle. However, the transmission of the weighing signal requires several key components, most of which are installed inside the garbage bin. Due to the corrosive gases within the garbage bin, the weighing components have a high failure rate. Traditional measurement methods place sensors on the crane or grab bucket to directly measure the weight change of the grabbed garbage and then record the data. Because cranes are mobile devices and the garbage bin contains high concentrations of corrosive gases, traditional weighing systems experience significant data fluctuations, making long-term stable and reliable operation difficult. The high concentrations of corrosive gases within the garbage bin, particularly HCl, are highly corrosive to cables and electronic equipment, requiring frequent maintenance and inspection, making continuous and stable operation difficult. Summary of the Invention

[0003] Purpose of the invention: In order to solve the problems existing in the above-mentioned prior art, the present invention provides a garbage crane control system with automatic weighing function.

[0004] Technical solution: The present invention provides a garbage crane control system with an automatic weighing function, comprising a current sensor, an adjustment circuit, an ADC module, and a PLC module; the current sensor, the adjustment circuit, and the ADC module are all arranged inside the trolley driving mechanism, and the PLC module is arranged in the trolley hoist inverter control cabinet;

[0005] The current sensor is used to obtain the current of the motor in the lifting inverter of the garbage crane's traveling mechanism and transmit the current to the adjustment circuit. The adjustment circuit is used to convert the current into a voltage signal. The ADC module converts the voltage signal into a digital signal D. The PLC module collects the digital signal of the ADC module and calculates the garbage weight based on the digital signal.

[0006] Furthermore, the PLC module calculates the weight of the garbage according to the following formula:

[0007] G=K*I

[0008] Where K is the calibration coefficient, I is the current, and the expression for I is:

[0009]

[0010] Among them, I min is the lower limit current value of the current sensor, I maxis the upper limit current value of the current sensor, Vmin is I min The corresponding voltage, Vmax is I max The corresponding voltage; V is the voltage obtained by converting the digital signal:

[0011]

[0012] Furthermore, the PLC module can also calculate the weight of the garbage according to the following formula:

[0013]

[0014] in, is the mean value of I.

[0015] Furthermore, the system also includes a weighing calibration module, which is arranged in the garbage crane distribution control room. The weighing calibration module is used to calibrate the calibration coefficient. Specifically, click on the weighing calibration on the touch screen in the garbage crane distribution room, select the corresponding grab to grab an object of known weight, and calculate the weight of the object through the PLC module. If the calculated weight does not match the actual weight of the object, the calibration coefficient K is calibrated.

[0016] Furthermore, the system also includes a distance detection module, which is arranged on the trolley driving mechanism of the garbage crane and is used to detect the distance between the two trolley driving mechanisms. When the distance is less than or equal to a preset distance threshold, the operation of the trolley driving mechanism is stopped.

[0017] Furthermore, the distance detection module uses a light sensor to measure distance.

[0018] Furthermore, the system also includes a confirmation button, which is set at the feeding port. The confirmation button is connected to the PLC module. When the garbage is lifted above the feeding port, the confirmation button is pressed to obtain the accurate garbage input time and the weight of the garbage input into the feeding port.

[0019] Furthermore, the system also includes a state judgment module for monitoring the operating state of the vehicle lifting inverter. If the motor is in a steady-state operation stage, the current collected by the current sensor at this time is used for weight calculation.

[0020] Furthermore, the PLC module transmits data to the host computer via serial communication or Ethernet communication.

[0021] Furthermore, it also includes a report adjustment and optimization module, which is used to count the weight, furnace mouth and furnace entry time of each bucket of garbage entering the furnace; automatically accumulate the weight entering the furnace in a shift, daily weight entering the furnace and monthly weight entering the furnace based on the statistical information, and generate a report.

[0022] Beneficial Effects: This invention places the PLC module in the control room rather than in the garbage bin, thereby preventing gas corrosion and extending the service life of the weighing system. Furthermore, the invention provides more stable operation and improved weighing accuracy. The weighing module and signal transmission module in the original system can be omitted, significantly reducing investment and maintenance costs. This invention further facilitates power plant efficiency calculation and parameter control. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a system structure diagram of the present invention.

[0024] Figure 2 This is a report chart generated by the system of the present invention. DETAILED DESCRIPTION

[0025] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0026] The system of the present invention is as follows Figure 1 As shown, this system only adds a sampling PLC to collect the inverter's current signal in real time. This signal is then transmitted to the weighing cabinet using a Modbus communication cable. The weighing module and signal transmission module in the original system can be omitted, significantly reducing investment and maintenance costs. The PLC module is located in the vehicle hoist inverter control cabinet.

[0027] Furnace entry signal judgment and weighing calibration system

[0028] The garbage crane weighing system detects the distance between the two trolley driving mechanisms according to the distance detection system. When the distance is less than the preset threshold, the operation of the trolley driving mechanism is stopped.

[0029] The original garbage crane system used limit switches to detect garbage inlet signals. However, due to severe corrosion within the pit, the limit signals were often unstable, affecting weighing stability. This embodiment incorporates a confirmation button at the feed port. Each confirmation button is connected to a PLC module. When garbage is added, pressing the confirmation button accurately determines the time the garbage was added.

[0030] A weighing calibration button has been added to simulate the grab bucket rising to the rising deceleration position signal. During calibration, the grab bucket does not need to be raised to the feeding port to complete the calibration. Specifically, click on the weighing calibration on the touch screen in the garbage crane distribution room, select the corresponding grab bucket to grab an object of known weight, and calculate the weight of the object through the PLC module. If the calculated weight does not match the actual weight of the object, the calibration coefficient K is calibrated.

[0031] Data statistics and reporting system

[0032] The data statistics and reporting system is based on weighing software, with the built-in data and the corresponding relationship between garbage weight as the core. The weighing software collects data based on the current and speed signals of the inverter to obtain weighing data.

[0033] The motor current analog signal is obtained through a current sensor installed on the output side of the inverter. This analog signal is generally in the milliampere range (e.g., 4-20mA) and needs to be converted into a voltage signal (0-3V) suitable for analog-to-digital conversion (ADC) input through a signal conditioning circuit.

[0034] The ADC converts the analog voltage signal into a digital signal and sends it to the microcontroller (such as PLC, single-chip microcomputer, etc.). Assume that the resolution of the ADC is n bits and the input voltage range is V min to V max， The collected digital quantity is D, and the corresponding actual voltage V is:

[0035] According to the conversion relationship of the current sensor (such as 4-20mA corresponds to 0-3V), the voltage is converted into the current value I. Assume that the lower limit current of the current sensor is I min Corresponding voltage V min， Upper limit current I max Corresponding voltage V max， Then the expression of I is:

[0036]

[0037] The above-mentioned current sensor, adjustment circuit, ADC module and current conversion module are all arranged inside the driving mechanism.

[0038] Weight calculation

[0039] After determining that the motor is in a stable operating state (not in the starting and braking phase), the microcontroller calculates the garbage weight G using the formula G=K*I based on the coefficient K obtained by calibration.

[0040] In order to improve the measurement accuracy, the method of multiple sampling and averaging can be used. For example, within a period of time T, N current values ​​I1, I2...I N , first calculate the average current Recalculate the weight

[0041] Data acquisition and processing is performed through the data acquisition and processing module. The ADC is periodically triggered to acquire voltage signals, ensuring timely and accurate acquisition. Filtering algorithms for the collected raw data include mean filtering and median filtering. For example, mean filtering averages multiple sample values ​​within a data window to smooth the data.

[0042] The status determination module monitors the inverter's operating status signals (such as start, stop, and operating frequency) to determine whether the motor is in the starting, steady-state, or braking phase. Current data collected only during steady-state operation is used for weight calculation, minimizing interference from current fluctuations during the starting and braking phases.

[0043] The weight is calculated using the calibration coefficient K based on the current data collected during stable motor operation. The calculated weight data is stored and output, and can be transmitted to a host computer or other control system via serial communication, Ethernet communication, etc. for display, recording, and further processing.

[0044] Report system optimization and adjustment:

[0045] Run the actual class division sequence, automatically divide the data into classes, record how to divide the data into classes and form a database file.

[0046] Statistics are collected for each bucket of garbage entering the furnace, including weight, furnace mouth, time of entering the furnace, etc., and automatically accumulated as shift weight, daily weight, monthly weight, etc., to form a report system for analysis. Figure 2 shown.

[0047] This embodiment takes a 750t / d garbage incinerator in Tianjin as the research object. The traditional garbage crane weighing system has large weight fluctuations when the garbage crane is raised and lowered. The sensor data is transmitted using optical fiber. The internal distribution box weighs the auxiliary equipment. There is corrosive gas in the warehouse. The internal distribution box cannot be completely sealed. The gas seriously corrodes and interferes with the electronic equipment. The weighing error is about ±10%, which affects the statistical power generation per ton of garbage by about ±10%. The average deviation of the measurement data for each bucket of garbage (8 tons of garbage net weight) is no more than ±10% (deviation of ±800kg). The solution of the present invention was used for transformation. After the transformation, there is no equipment inside, and the weighing error is reduced to ±1%. The average deviation of the measurement data for each bucket of garbage (8 tons of garbage net weight) is no more than ±1% (no more than ±80kg). The statistical power generation per ton of garbage affects about ±1%, reducing the error rate by about ±9%.

[0048] This embodiment uses a 300t / d waste incinerator in Shandong as an example. The traditional waste crane weighing system experiences large weight fluctuations when the crane is raised and lowered. Sensor data is transmitted using hard wiring, and the internal distribution box weighs the auxiliary equipment. Corrosive gases exist in the warehouse, and the internal distribution box cannot be completely sealed, causing severe corrosion and interference to electronic equipment. The weighing error is approximately ±11%, which affects the statistical power generation per ton of waste by approximately ±11%. The average deviation of the measured data per bucket of waste (8 tons of net weight) is no more than ±11% (deviation of ±880kg). The solution of the present invention was used for the modification. After the modification, no internal equipment was required, and the weighing error was reduced to ±1%. The average deviation of the measured data per bucket of waste (8 tons of net weight) is no more than ±1% (no more than ±80kg). The statistical power generation per ton of waste is affected by approximately ±1%, reducing the error rate by approximately ±10%.

[0049] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. To avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A garbage crane control system with automatic weighing function, characterized in that: It includes a current sensor, an adjustment circuit, an ADC module and a PLC module; the current sensor, the adjustment circuit and the ADC module are all arranged inside the trolley driving mechanism, and the PLC module is arranged in the vehicle lifting inverter control cabinet; The current sensor is used to obtain the current of the motor in the lifting inverter of the garbage crane's traveling mechanism and transmit the current to the adjustment circuit. The adjustment circuit is used to convert the current into a voltage signal. The ADC module converts the voltage signal into a digital signal D. The PLC module collects the digital signal of the ADC module and calculates the garbage weight based on the digital signal.

2. A garbage crane control system with automatic weighing function according to claim 1, characterized in that: The PLC module calculates the garbage weight according to the following formula: G=K*I Where K is the calibration coefficient, I is the current, and the expression for I is: Among them, I min is the lower limit current value of the current sensor, I max is the upper limit current value of the current sensor, Vmin is I min The corresponding voltage, Vmax is I max The corresponding voltage; V is the voltage obtained by converting the digital signal:

3. The garbage crane control system with automatic weighing function according to claim 2 is characterized in that: The PLC module can also calculate the weight of garbage according to the following formula: in, is the mean value of I.

4. The garbage crane control system with automatic weighing function according to claim 2 is characterized in that: The system also includes a weighing calibration module, which is arranged in the garbage crane distribution control room. The weighing calibration module is used to calibrate the calibration coefficient. Specifically, click weighing calibration on the touch screen in the garbage crane distribution room, select the corresponding grab to grab an object of known weight, and calculate the weight of the object through the PLC module. If the calculated weight does not match the actual weight of the object, the calibration coefficient K is calibrated.

5. The garbage crane control system with automatic weighing function according to claim 1 is characterized in that: The system also includes a distance detection module, which is arranged on the trolley driving mechanism of the garbage crane and is used to detect the distance between the two trolley driving mechanisms. When the distance is less than or equal to a preset distance threshold, the operation of the trolley driving mechanism is stopped.

6. The garbage crane control system with automatic weighing function according to claim 5, characterized in that: The distance detection module uses a light sensor to measure distance.

7. The garbage crane control system with automatic weighing function according to claim 1 is characterized in that: The system also includes a confirmation button, which is set at the feeding port and connected to the PLC module. When the garbage is lifted above the feeding port, the confirmation button is pressed to obtain the accurate garbage feeding time and the weight of the garbage fed into the feeding port.

8. The garbage crane control system with automatic weighing function according to claim 1 is characterized in that: The system also includes a state judgment module for monitoring the operating state of the vehicle lifting inverter. If the motor is in the steady-state operation stage, the current collected by the current sensor at this time is used for weight calculation.

9. The garbage crane control system with automatic weighing function according to claim 1, characterized in that: The PLC module transmits data to the host computer through serial communication or Ethernet communication.

10. The garbage crane control system with automatic weighing function according to claim 1, characterized in that: It also includes a report adjustment and optimization module, which is used to count the weight, furnace mouth and furnace entry time of each bucket of garbage entering the furnace; based on the statistical information, it automatically accumulates the weight entering the furnace per shift, daily weight entering the furnace and monthly weight entering the furnace, and generates reports.

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