A heavy-load material reversing system based on four-corner synchronous jacking

Abstract

The present application relates to the field of intelligent logistics and material handling equipment, in particular to a heavy load material reversing system based on four-corner synchronous jacking, comprising a jacking reversing device, containing four independent speed-adjusting jacking mechanisms, a bearing frame and a rotary driving mechanism, which completes reversing through synchronous jacking, rotation and descending; a detection device, integrating displacement, pressure, current, vibration, temperature sensors and anti-intrusion switches, which collects multi-dimensional operation records; a control system, wherein the main controller generates reversing instructions according to tasks and collected data, and the bottom controller drives the jacking reversing device and coordinates discharging accordingly; a safety interlocking loop, which is independent of the above-mentioned controllers and is connected in series in the driving power supply circuit, cutting off the driving power supply when triggering the limit or fault; the present application guarantees the safety and execution reliability of the heavy load material reversing process.

Description

Technical Field

[0001] This invention relates to the field of intelligent logistics and material handling equipment, specifically a heavy-duty material reversing system based on four-corner synchronous lifting. Background Technology

[0002] Existing heavy-duty material reversing systems typically use a single lifting mechanism or a simple linkage mechanism to lift, turn, and lower materials.

[0003] In related technologies, in order to achieve the direction switching of materials in the conveyor line, the conveying mechanism first sends the material to the reversing position, and then the lifting mechanism lifts the material off the conveying surface. The rotating mechanism then completes the angle adjustment and sends it back to the discharge side. Such solutions usually rely on single-point position detection or simple positioning signals to determine the timing of the action, and do not adequately consider the linkage control of the four corner synchronization, bearing posture, stable state before rotation, and discharge sequence during the lifting process.

[0004] However, during the reversal process of heavy-loaded materials, off-center-loaded materials, or long-sized materials, a single position judgment can easily lead to asynchronous lifting, tilting of the bearing posture, material slippage during rotation, or even premature action when the workstation is not clear or the discharge conditions are not met, thereby affecting the reversal stability and equipment safety. Therefore, the heavy-load material reversal method in related technologies is difficult to balance synchronous lifting accuracy, stability confirmation before rotation, and overall operational safety. Summary of the Invention

[0005] The purpose of this invention is to provide a heavy-duty material reversing system based on four-corner synchronous lifting, which solves the problems of asynchronous lifting, tilting of the bearing posture, material slippage during rotation, and premature action when the work station is not clear during the reversing of heavy-duty materials, off-center materials, or long-sized materials. It improves the synchronous lifting accuracy, the reliability of stability confirmation before rotation, and the overall operational safety during material reversing.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A heavy-duty material reversing system based on four-corner synchronous lifting is applied to a logistics channel including an inlet conveying mechanism, an outlet channel, an outlet conveying mechanism, a reversing station, and a rotating area, comprising:

[0008] The lifting and reversing device is arranged at the reversing station and includes four independently speed-adjustable lifting mechanisms, a lifting support frame, a rotary drive mechanism, a brake, a limit switch, a driver, and a driver alarm port.

[0009] The detection device, arranged on the reversing station, rotating area and lifting reversing device, includes displacement sensor, pressure sensor, current sensor, vibration sensor, temperature sensor and anti-intrusion detection switch.

[0010] The control system is communicatively connected to the detection device, inlet conveying mechanism, outlet conveying mechanism, and lifting and reversing device. The control system includes a main controller and a lower-level controller.

[0011] The main controller generates a reversing control command containing lifting height, rotation angle and speed control quantities based on the task information of the host computer and the data collected by the detection device, sends it to the bottom controller, and sends a start command to the material conveying mechanism.

[0012] The bottom-level controller receives commutation control commands and outputs drive signals to the lifting commutation device;

[0013] The safety interlock circuit is independent of the main controller and the bottom controller. The input of the safety interlock circuit is connected to the limit switch and the alarm port of the driver, and the output of the safety interlock circuit is connected in series to the power supply circuit of the driver of the lifting reversing device.

[0014] In some possible implementations, the detection device also includes an inlet detection sensor, a workstation detection sensor, a material edge detection sensor, an outlet detection sensor, and a descent position detection switch;

[0015] The detection device uses an inlet detection sensor, a station detection sensor, and a material edge detection sensor to jointly confirm that the front end of the material enters, the main body is located on the lifting support frame, and the tail end passes the inlet detection sensor. It also uses an outlet detection sensor and an anti-intrusion detection switch to confirm that no object is detected in the rotating area and the discharge channel.

[0016] When the detection device detects that the material arrival signal is continuously greater than or equal to the first preset time threshold, the control system controls the inlet conveying mechanism to stop and controls the lifting and reversing device to lift until the pressure detection values ​​of the four lifting mechanisms are all greater than zero.

[0017] In some possible implementations, the main controller is used to determine the lifting speed, rotation speed, lifting acceleration, and settling time based on the material type, material arrival status, reversing station, rotation area, and unobstructed status of the discharge channel in the task information from the host computer, and to generate reversing control commands.

[0018] The underlying controller is used to verify whether the speed and position parameters in the commutation control command are within the preset safety limit range. If the verification is successful, the commutation control command is executed; if the verification fails, the command is rejected and an alarm signal is fed back.

[0019] In some possible implementations, the underlying controller uses the lifting height as the lifting reference for the four lifting mechanisms, calculates the difference between the height value of each lifting mechanism and the average height of the four corners, decelerates the lifting mechanism with a height value greater than or equal to the average height of the four corners, and accelerates the lifting mechanism with a height value less than the average height of the four corners.

[0020] When the pressure detection value of the pressure sensor of the four lifting mechanisms exceeds the preset pressure threshold or the current detection value of the current sensor of the corresponding drive mechanism exceeds the preset current threshold, the bottom controller reduces the acceleration compensation amount for the lifting mechanism whose height value is less than the average height of the four corners.

[0021] In some possible implementations, the underlying controller calculates the maximum height difference at the four corners based on the height values ​​of the four lifting mechanisms, and calculates the diagonal height difference on two sets of diagonals;

[0022] The bottom-level controller outputs a signal allowing the rotary drive mechanism to start only when the four lifting mechanisms reach the lifting height, the maximum height difference at the four corners is less than the first height difference threshold, the diagonal height difference is less than the second height difference threshold, the pressure deviation at the four corners is less than the pressure deviation threshold, the vibration amplitude is less than the vibration threshold, and the vibration amplitude is greater than or equal to the second preset time threshold, and the safety interlock circuit is not triggered to cut off.

[0023] In some possible implementations, after the total pressure of the four lifting mechanisms reaches the pre-configured total load pressure threshold, the bottom-level controller calculates the pressure deviation at the four corners based on the pressure detection values ​​of each lifting mechanism, and determines the off-center load status of the material based on the pressure deviation at the four corners.

[0024] When the total pressure does not reach the total load pressure threshold, if the difference between the pressure change rate and the corresponding displacement change rate of any lifting mechanism is greater than or equal to the preset matching threshold, the bottom controller determines that the pressure detection of the lifting mechanism is abnormal and stops automatic operation.

[0025] In some possible implementations, the underlying controller fits the tilt angle of the lifting support frame based on the height values ​​of the four lifting mechanisms. And based on the friction coefficient of the corresponding material type obtained from the pre-configured control system memory. Rotation radius of the lifting support frame Angular velocity of the rotary drive mechanism and pre-configured system security factor Calculate material slip risk The calculation formula is:

[0026]

[0027] in, The acceleration is due to gravity; a first set threshold and a second set threshold are preset, and the first set threshold is less than the second set threshold; when there is a risk of material slippage. When the first threshold is set, rotate at the current angular velocity;

[0028] When the first set threshold When the second threshold is set, the angular velocity and angular acceleration are reduced; when When the second threshold is set, the speed is reduced and stopped. If the material edge detection sensor detects that the material exceeds the preset boundary of the lifting support frame, the material will reverse slowly and return to the initial position. If the material does not exceed the threshold, the material will remain in the original position.

[0029] In some possible implementations, the underlying controller controls the lifting and reversing device in the following order: synchronous lifting is performed after the material is in place; rotation is started after the target height is reached and stability is confirmed; the brake is triggered to complete braking after the rotation reaches the rotation angle;

[0030] After the rotation is completed, when the outlet detection sensor has not detected an obstruction signal for a period of time greater than or equal to the third preset time threshold, the main controller determines that the discharge channel is empty and issues a start discharge command.

[0031] The bottom-level controller detects that the pressure drop at the four corners is greater than or equal to the set unloading threshold, the displacement at the four corners reaches the preset initial position and the descent is complete, and the detection switch is triggered. After confirming that the load has been transferred and the lifting mechanism has retreated to the preset height range, the controller starts the discharge conveyor mechanism.

[0032] In some possible implementations, the heavy-duty material reversing system also includes an emergency stop switch, an upper limit switch, a lower limit switch, and a rotary limit switch. The safety interlock circuit directly collects signals from the emergency stop switch, the upper limit switch, the lower limit switch, the rotary limit switch, the anti-intrusion detection switch, and the alarm port of the driver.

[0033] When communication between the main controller and the underlying controller is interrupted, the underlying controller is prohibited from entering the next action phase and performs the corresponding action according to the current phase: if it is in the lifting phase, it performs synchronous descent to the initial position; if it is in the rotation phase, it triggers the brake to perform position holding.

[0034] If the device is in the descent phase, it will continue to descend synchronously to the initial position. After the fault is cleared, the material position, mechanism position, and safety conditions must be reconfirmed by the sensors. The device can only be operated after the restart conditions are met.

[0035] In some possible implementations, the main controller adjusts the lifting speed, rotation speed, and settling time for subsequent similar tasks with the same material type and reversing angle based on the recorded historical operation records, including the height difference at the four corners, pressure deviation at the four corners, vibration, drive current, and abnormal records.

[0036] When the historical operation record shows an overcurrent abnormality caused by the drive current exceeding the rated value or a slip warning indicating that the risk of material slippage is greater than the first set threshold, the main controller reduces the lifting speed and rotation speed and extends the stabilization time after reaching the target height when generating reversing control commands for subsequent similar tasks. At the same time, it records the speed parameters, time parameters and triggering reasons before and after the adjustment in the memory.

[0037] The beneficial effects of this invention are:

[0038] 1. This invention is based on a heavy-duty material reversing system with four-corner synchronous lifting. The reversing station is equipped with an overall structure including four independent speed-regulating lifting mechanisms, a lifting support frame, a rotary drive mechanism, a detection device, a control system, and an independent safety interlocking circuit. The main controller generates reversing control commands containing lifting height, rotation angle, and speed control values. The lower-level controller performs parameter verification and drive output. It can complete the entire process of material receiving, lifting, rotation, and descent before discharge. This not only improves the clarity of control division in the heavy-duty material reversing process, but also ensures that the drive action is always constrained by the safety interlocking circuit, thereby improving the problem of insufficient overall operational safety in related technologies.

[0039] 2. The present invention is a heavy-duty material reversing system based on four-corner synchronous lifting. The system uses an inlet detection sensor, a station detection sensor, a material edge detection sensor, an outlet detection sensor, and an anti-intrusion detection switch to jointly form the material arrival condition and the area clearance condition. After the material arrival signal lasts for a preset time, the inlet conveying mechanism stops, and then the lifting and reversing device is controlled to lift until the pressure detection values ​​at all four corners are greater than zero to determine that the material is in contact. This can avoid the problems of premature lifting, premature rotation, and malfunction caused by relying on a single position judgment, and improve the reliability of material entry judgment and rotation area clearance judgment.

[0040] 3. The present invention is a heavy-duty material reversing system based on four-corner synchronous lifting. The bottom controller uses the average height of the four corners as a reference, decelerates the lifting mechanism that is higher than the average height, and accelerates the lifting mechanism that is lower than the average height to compensate. It also combines the pressure at the four corners and the driving current to classify and limit the speed compensation coefficient, so that the maximum height difference between the four corners and the diagonal height difference are kept within the preset allowable range. It can continuously control the posture of the bearing frame during the formal lifting process, reduce the bearing tilting problem caused by asynchronous lifting, and thus improve the synchronous lifting accuracy when reversing heavy-duty, off-center, or long-sized materials. Attached Figure Description

[0041] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0042] Figure 1 This is a schematic diagram of a heavy-duty material reversing system based on four-corner synchronous lifting, provided in an embodiment of this application. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] Please see Figure 1 A heavy-duty material reversing system based on four-corner synchronous lifting is applied to a logistics channel including an inlet conveying mechanism, an outlet channel, an outlet conveying mechanism, a reversing station, and a rotating area, comprising:

[0045] The lifting and reversing device is arranged at the reversing station and includes four independently speed-adjustable lifting mechanisms, a lifting support frame, a rotary drive mechanism, a brake, a limit switch, a driver, and a driver alarm port.

[0046] The detection device, arranged on the reversing station, rotating area and lifting reversing device, includes displacement sensor, pressure sensor, current sensor, vibration sensor, temperature sensor and anti-intrusion detection switch.

[0047] The control system is communicatively connected to the detection device, inlet conveying mechanism, outlet conveying mechanism, and lifting and reversing device. The control system includes a main controller and a lower-level controller.

[0048] The main controller generates a reversing control command containing lifting height, rotation angle and speed control quantities based on the task information of the host computer and the data collected by the detection device, sends it to the bottom controller, and sends a start command to the material conveying mechanism.

[0049] The bottom-level controller receives commutation control commands and outputs drive signals to the lifting commutation device;

[0050] The safety interlock circuit is independent of the main controller and the bottom controller. The input of the safety interlock circuit is connected to the limit switch and the alarm port of the driver, and the output of the safety interlock circuit is connected in series to the power supply circuit of the driver of the lifting reversing device.

[0051] In a preferred embodiment of the present invention, the detection device further includes an inlet detection sensor, a workstation detection sensor, a material edge detection sensor, an outlet detection sensor, and a descent position detection switch;

[0052] The detection device uses an inlet detection sensor, a station detection sensor, and a material edge detection sensor to jointly confirm that the front end of the material enters, the main body is located on the lifting support frame, and the tail end passes the inlet detection sensor. It also uses an outlet detection sensor and an anti-intrusion detection switch to confirm that no object is detected in the rotating area and the discharge channel.

[0053] When the detection device detects that the material arrival signal is greater than or equal to the first preset time threshold, the control system controls the inlet conveying mechanism to stop and controls the lifting and reversing device to lift until the pressure detection values ​​of the four lifting mechanisms are all greater than zero.

[0054] The main controller is used to determine the lifting speed, rotation speed, lifting acceleration and settling time based on the material type, material arrival status, reversing station, rotation area and unobstructed status of the discharge channel in the task information from the host computer, and to generate reversing control commands.

[0055] The underlying controller is used to verify whether the speed and position parameters in the commutation control command are within the preset safety limit range. If the verification is successful, the commutation control command is executed; if the verification fails, the command is rejected and an alarm signal is fed back.

[0056] This system is installed in the middle of the roller conveyor line and is used to change the direction of pallet, material frame or tooling plate from the inlet conveying direction to the outlet channel direction;

[0057] A lifting and reversing device is installed at the reversing station. The lifting and reversing device includes four lifting mechanisms driven separately, a lifting support frame located above the four lifting mechanisms, and a rotary drive mechanism that cooperates with the lifting support frame.

[0058] Four lifting mechanisms act on the four support positions of the support frame respectively, so that after the material leaves the inlet conveying mechanism, it is received by the support frame, and then the rotary drive mechanism drives the support frame to rotate to the target angle and descend to the pipe height of the discharge conveying mechanism.

[0059] In the specific implementation, displacement sensors are set for four lifting mechanisms respectively to generate height detection values ​​at the four corners;

[0060] Pressure sensors are installed at the four support positions to obtain pressure detection values ​​at the four corners; current sensors are connected to the lifting drive and rotation drive to record the drive current.

[0061] Vibration and temperature sensors are installed on the lifting and reversing device or its adjacent installation location to record vibration and temperature data during operation; an intrusion detection switch is installed at the boundary of the rotating area to determine whether personnel or foreign objects have entered the rotating area.

[0062] The above-mentioned data collection results are sent to the control system. The main controller stores the task information, station status and material discharge status. After receiving the reversing control command issued by the main controller, the bottom controller outputs the drive signals of each lifting mechanism and rotary drive mechanism according to the corresponding stage.

[0063] The safety interlock circuit does not go through the software judgment link of the main controller and the bottom controller, but is directly connected to the limit switch and the alarm port of the drive. When the upper limit, lower limit, rotation limit or drive fault signal is established, the power supply circuit of the lifting reversing device drive is directly cut off.

[0064] In this embodiment, the four lifting mechanisms are preferably servo electric cylinders. The rated stroke of a single lifting mechanism is 300 mm, the rated lifting speed is 50 mm / s, and the rated load is 10 kN. The lifting support frame is a steel rectangular frame with an external dimension of 1600 mm x 1600 mm. The four support positions are arranged symmetrically in a square, with a spacing of 1200 mm between adjacent support positions and a spacing of approximately 1697 mm between the two sets of diagonal support positions. The rotation drive mechanism is preferably a servo motor that drives the lifting support frame to rotate via a reducer. The rotation radius of the lifting support frame is taken as the maximum horizontal distance from the geometric center of the support frame to the outer edge of the material being carried. In this embodiment, it is taken as 1 meter. The allowable range of the rotation angle is 0 degrees to 180 degrees, and the preset upper limit of the lifting height is 300 mm.

[0065] In this embodiment, the displacement sensors are preferably magnetostrictive displacement sensors or laser displacement sensors, with a range of 0 to 400 mm and a measurement accuracy of ±0.1 mm. They are installed on the four lifting mechanisms and move synchronously with them. The pressure sensors are preferably resistance strain gauge load cells, with a range of 0 to 20 kN and an accuracy class of 0.5. They are installed between the four support positions and the lifting support frame. The current sensors are preferably Hall effect closed-loop current sensors, with a range of 0 to 50 amperes and a measurement accuracy of ±0.5%. They are connected in series in the power supply lines of the lifting drive and rotation drive. The vibration sensors are preferably piezoelectric. An accelerometer with a range of ±50g and a frequency response range of 1 Hz to 5 kHz is installed at the bottom of the lifting support frame. A PT100 platinum resistance temperature sensor with a temperature range of -20°C to 150°C is preferably installed on the driver's heat dissipation unit. Through-beam photoelectric sensors are preferred for the inlet detection, workstation detection, material edge detection, and outlet detection sensors, with a response time of no more than 1 millisecond. A safety light curtain with a beam resolution of 30 mm and a response time of no more than 20 milliseconds is preferred for the intrusion detection switch. An inductive proximity switch is preferred for the descent detection switch.

[0066] In this embodiment, the main controller is preferably a programmable logic controller or an industrial computer, the lower controller is preferably a multi-axis motion controller, and the driver is preferably a servo driver. The main controller and the lower controller preferably communicate via EtherCAT industrial Ethernet with a communication period of 4 milliseconds, but PROFINET or EtherNet / IP fieldbus can also be used. The sampling period of the lower controller is the same as the control period. In this embodiment, the sampling period is 4 milliseconds, and the signal scanning period of the safety interlock circuit is no more than 10 milliseconds.

[0067] During actual operation, the host computer sends task information to the main controller. The task information includes at least the current material reversal direction and target angle.

[0068] The main controller combines the reversing station status, the rotation area status, and the collected detection data to generate a reversing control command that includes lifting height, rotation angle, and speed control values, and writes the command into the task receiving area of ​​the underlying controller.

[0069] After reading the instruction, the underlying controller does not directly change the motion state, but first performs range verification on the speed and position parameters.

[0070] The verification includes whether the lifting height exceeds the preset travel limit, whether the rotation angle is within the allowable angle range, whether the lifting speed and rotation speed are higher than the equipment's allowable values, and whether the lifting acceleration exceeds the preset boundary.

[0071] When the verification passes, the lower-level controller marks the task as executable and then outputs a drive signal to the lifting and reversing device; when the verification fails, the lower-level controller keeps the drive disabled and returns an alarm signal to the main controller, which then stops the current task from being issued.

[0072] If the task is executed directly based on a single task instruction, premature lifting or rotation may occur if the material has not entered the effective carrying area or if there is still obstruction in the rotation area.

[0073] The detection device is further equipped with an inlet detection sensor, a station detection sensor, a material edge detection sensor, and an outlet detection sensor; the inlet detection sensor is used to confirm that the front end of the material has entered the reversing station; the station detection sensor is used to confirm that the main body of the material is above the lifting support frame;

[0074] The material edge detection sensor is used to confirm that the tail end of the material has passed the inlet detection position; the outlet detection sensor and the anti-intrusion detection switch are used together to confirm that there are no obstructions in the rotating area and the discharge channel.

[0075] The control system does not act immediately based on any single detection value, but combines the above detection results into material arrival conditions and area clearance conditions; only when the material arrival signal is continuously maintained until the first preset time threshold, and the rotating area and the discharge channel remain unobstructed, does the control system stop the inlet conveying mechanism and control the lifting and reversing device to lift from the low position upward.

[0076] The initial lifting stage does not immediately enter the formal lifting phase. Instead, it continues to rise for the purpose of contact determination until the pressure detection values ​​of the four lifting mechanisms are all greater than zero. Based on this, the control system determines that the support frame has contacted the material and then enters the subsequent lifting stage.

[0077] In this embodiment, the first preset time threshold is 1 second, preferably ranging from 0.5 seconds to 2 seconds. The adjustment method is to measure the average time required for the material front end to enter the reversing station and for the material posture to stabilize at the rated conveying speed, and take 1.5 times to 2 times the average time as the first preset time threshold. By continuously timing, the short-term false signals caused by the instantaneous shaking of the sensor and the slight bouncing of the material are filtered out.

[0078] If there is a brief inconsistency between the inlet detection sensor, the station detection sensor, and the material edge detection sensor, the control system will not directly confirm the position, but will maintain the original state of the inlet conveying mechanism and continue to wait for the re-collection of results.

[0079] If the outlet detection sensor or anti-intrusion detection switch indicates that the rotating area or the discharge channel is blocked, the main controller will not generate the action conditions that allow the lifting. Through the above judgment logic, the material entry judgment and the rotating area clearance judgment are separated, avoiding false actions caused by single-point false detection.

[0080] After confirming the validity of the task information, the main controller further combines the material type, material arrival status, unobstructed status of the reversing station, unobstructed status of the rotating area, and unobstructed status of the exit to determine the lifting speed, rotation speed, lifting acceleration, and stabilization time to be used in this task.

[0081] For tasks where the mass is greater than or equal to a preset mass threshold, the shape is greater than or equal to a preset size threshold, or the target angle is greater than or equal to a preset angle threshold, the main controller can select a lifting speed and rotation speed lower than the preset reference value and extend the stabilization time.

[0082] For the preset standard operating conditions, the pre-configured standard gear can be used; these parameters are written into the reversing control command and sent to the bottom controller; the bottom controller does not regenerate the process parameters, but is only responsible for checking whether the speed and position parameters given by the main controller are within the preset safety limit range;

[0083] If the parameters fall within the allowable range, the corresponding instruction is executed; if the parameters exceed the allowable range, execution is rejected and an alarm signal is fed back. This separates task selection from on-site execution, with the main controller responsible for determining parameters at the task level and the lower-level controller responsible for boundary verification on the equipment side.

[0084] In this implementation, if communication between the main controller and the underlying controller is interrupted, the underlying controller will not receive new action commands. If the system is in the standby stage at this time, it will remain in the current unstarted state. If the system is already running, it will perform a security degradation action according to the current stage. If the task is still valid after communication is restored, it can re-enter parameter verification.

[0085] If the task has failed, the main controller will regenerate the control command. In this way, the system can complete the basic process of material entry, bearing, reversing and pre-discharge preparation in the middle section of the roller conveyor line, and ensure that the drive action is always constrained by the safety interlock circuit.

[0086] In a preferred embodiment of the present invention, the bottom-level controller uses the lifting height as the lifting reference for the four lifting mechanisms, calculates the difference between the height value of each lifting mechanism and the average height of the four corners, decelerates the lifting mechanism whose height value is greater than or equal to the average height of the four corners, and accelerates the lifting mechanism whose height value is less than the average height of the four corners.

[0087] When the pressure detection value of the pressure sensor of the four lifting mechanisms exceeds the preset pressure threshold or the current detection value of the current sensor of the corresponding drive mechanism exceeds the preset current threshold, the bottom controller reduces the acceleration compensation amount for the lifting mechanism whose height value is less than the average height of the four corners.

[0088] The bottom-level controller calculates the maximum height difference at the four corners based on the height values ​​of the four lifting mechanisms, and also calculates the diagonal height difference between the two sets of diagonals.

[0089] The bottom controller outputs a signal that allows the rotary drive mechanism to start only when the four lifting mechanisms reach the lifting height, the maximum height difference at the four corners is less than the first height difference threshold, the diagonal height difference is less than the second height difference threshold, the pressure deviation at the four corners is less than the pressure deviation threshold and the vibration amplitude is less than the vibration threshold, and the vibration amplitude is greater than or equal to the second preset time threshold, and the safety interlock circuit is not triggered to cut off.

[0090] After the total pressure of the four lifting mechanisms reaches the pre-configured total load pressure threshold, the bottom-level controller calculates the pressure deviation at the four corners based on the pressure detection values ​​of each lifting mechanism, and judges the off-center load status of the material based on the pressure deviation at the four corners.

[0091] When the total pressure does not reach the total load pressure threshold, if the difference between the pressure change rate and the corresponding displacement change rate of any lifting mechanism is greater than or equal to the preset matching threshold, the bottom controller determines that the pressure detection of the lifting mechanism is abnormal and stops automatic operation.

[0092] When the material stops at the reversing station and is contacted by the lifting support frame, the system enters the lifting stage. During the lifting process, the posture of the support frame is controlled to avoid the material tilting due to inconsistent lifting at the four corners.

[0093] The bottom-level controller uses the set target height as the lifting reference that the four lifting mechanisms follow together, and periodically reads the height values ​​corresponding to the four lifting mechanisms. The bottom-level controller first calculates the average height from the height values ​​at the four corners, and then calculates the difference between the height value of each lifting mechanism and the average height at the four corners.

[0094] For lifting mechanisms with a height value greater than the average height of the four corners, it indicates that the lifting progress of the support position is relatively fast, and the bottom controller reduces its driving speed accordingly; for lifting mechanisms with a height value less than the average height of the four corners, it indicates that the lifting progress of the support position is relatively slow, and the bottom controller increases its driving speed.

[0095] Based on the speed compensation configuration described above, although the four lifting mechanisms are driven separately, they maintain a relatively consistent lifting process at the same target height; the average height at the four corners is obtained by averaging the current height values ​​of the four lifting mechanisms.

[0096] The maximum height difference at the four corners is obtained by the difference between the maximum and minimum values ​​among the four height values; the two sets of diagonal height differences are represented by the absolute values ​​of the difference between the height values ​​at the two ends of the first diagonal and the absolute values ​​of the difference between the height values ​​at the two ends of the second diagonal, respectively.

[0097] The underlying controller repeats the above calculations at a fixed sampling period and uses the height difference obtained in each period as the input for speed compensation in the next period.

[0098] Speed ​​compensation is performed according to a preset judgment sequence: first, four height values ​​are read and the average height of the four corners is calculated, and then the height difference corresponding to each lifting mechanism is obtained;

[0099] Each height difference is compared with a pre-configured compensation dead zone. When the absolute value of the height difference of a certain lifting mechanism is less than or equal to the compensation dead zone, the lifting mechanism maintains its current speed.

[0100] When the height difference of a certain lifting mechanism is greater than the compensation dead zone, the lifting mechanism is marked as leading angle and the compensation level is reduced by one gear; when the height difference of a certain lifting mechanism is less than the negative value of the compensation dead zone, the lifting mechanism is marked as lagging angle and the compensation level is increased by one gear.

[0101] The compensation gears preferably include at least a holding gear, a low compensation gear, and a standard compensation gear. The speed correction amount corresponding to each gear is pre-stored in the control system memory. The underlying controller directly calls the corresponding gear according to the current height difference falling into the interval, without temporarily generating new compensation rules.

[0102] For any sampling period, if two or more leading angles or two or more lagging angles occur simultaneously in the four lifting mechanisms, the corresponding gears will still be called according to the interval to which their respective height differences belong, until the next sampling period is recalculated; the fixed sampling period is preferably one control cycle of the control system or an integer multiple thereof, and remains unchanged in the same lifting task;

[0103] The compensation dead zone, the speed correction amount corresponding to each compensation level, and the allowable range of height difference are preferably pre-tuned and written into the memory based on the size of the lifting support frame, the rated stroke, rated speed, and allowable tilt of the four lifting mechanisms; for lifting support frames of different specifications, the corresponding parameter groups can be stored separately.

[0104] At the start of the task, the main controller calls one of the sets according to the current equipment specifications. During the task execution, it does not switch again, so that the average height of the four corners, the maximum height difference of the four corners, the diagonal height difference, the compensation dead zone and the compensation level are calculated and controlled under the same parameter reference.

[0105] In this embodiment, the compensation dead zone is 2 mm, the speed correction corresponding to the holding gear is zero, the speed correction corresponding to the low compensation gear is 5% of the rated speed of the lifting mechanism, the speed correction corresponding to the standard compensation gear is 10% of the rated speed of the lifting mechanism, and the allowable height difference is 8 mm. The number of compensation gears is not limited to three gears, but can also be set to five gears, and the speed correction between adjacent gears increases in an arithmetic progression. The above parameters are tuned through a rated load lifting test, that is, lifting is performed under rated load with different compensation gears, and the gear parameters that make the maximum height difference at the four corners converge the fastest without speed overshoot are selected and written into the memory.

[0106] If compensation is based solely on height difference, when the off-center load exceeds the first preset off-center load threshold, to prevent local stress from increasing, the bottom-level controller synchronously reads the pressure at the four corners and the drive current, and uses them as the basis for compensation limiting. When any value of the pressure at the four corners or the pressure combination exceeds the preset pressure threshold, or the drive current exceeds the preset current threshold, the bottom-level controller reduces the speed compensation coefficient, so that the acceleration compensation for the lag angle and the deceleration correction for the lead angle both converge to the preset limiting compensation range.

[0107] The speed compensation coefficient can be selected according to a pre-configured grading method: when the four corner pressures and drive current are all within the normal range, the standard compensation level is selected; when any one of them approaches the corresponding threshold, the low compensation level is switched; when any one of them reaches or exceeds the corresponding threshold, the minimum compensation level is maintained and further acceleration is limited.

[0108] The coefficient values ​​for each gear are pre-calibrated by the equipment's rated load, the lifting mechanism's rated current, and the allowable attitude error, and written into the control system's memory. During operation, the underlying controller only calls the corresponding gear according to the detection range.

[0109] The approach to the corresponding threshold is preferably determined according to a fixed comparison rule: when the pressure detection value or drive current detection value is less than the first warning ratio of its corresponding threshold, the standard compensation level is adopted;

[0110] When the pressure detection value or drive current detection value is greater than or equal to the first warning ratio and less than the corresponding threshold, the low compensation level is used; when the pressure detection value or drive current detection value is greater than or equal to the corresponding threshold, the minimum compensation level is used and it is prohibited to increase the compensation level of any hysteresis angle.

[0111] In this embodiment, the first warning ratio is 80%, the preset pressure threshold is 90% of the maximum allowable load capacity of a single support position, and the preset current threshold is 1.2 times the rated current of the driver. When the rated speed of the lifting mechanism is 50 mm / s, the speed compensation coefficient of the standard compensation gear is 1.0, the speed compensation coefficient of the low compensation gear is 0.5, and the speed compensation coefficient of the minimum compensation gear is 0.2. Each coefficient is written into the memory after being pre-calibrated by the rated load of the equipment, the rated current of the lifting mechanism, and the allowable attitude error. During operation, the underlying controller only calls the corresponding gear according to the detection range.

[0112] If the pressure approaches the threshold and the current reaches the threshold simultaneously within the same sampling period, the underlying controller will execute at a more conservative level; the adjusted result will continue to be used for the drive output of subsequent periods to keep the maximum height difference at the four corners and the diagonal height difference within the preset height difference allowable range.

[0113] If the pressure or current abnormality returns to the allowable range in subsequent cycles, the underlying controller can restore the original compensation coefficient; if it continues to exceed the limit, it will maintain a low compensation state and limit further increases; the pressure combination relationship preferably includes the maximum value, minimum value and difference of the four corner pressures, and the underlying controller will call the compensation level based on the comparison result of at least one of them with the corresponding threshold.

[0114] When the pressure detection value and the current detection value fall into different risk ranges, the compensation level corresponding to the highest risk is used as the only execution level in this sampling cycle, thereby avoiding the simultaneous output of conflicting acceleration and limiting commands in the same cycle.

[0115] After the support frame reaches the target height, the bottom controller continuously reads the height values ​​of the four lifting mechanisms at the target height. The material may still be in a state of undiminished local vibration or uneven force at the four corners. In response, the bottom controller continuously reads the height values ​​of the four lifting mechanisms near the target height and calculates the maximum height difference at the four corners and the diagonal height difference on the two sets of diagonals.

[0116] Meanwhile, the underlying controller continues to calculate the corner pressure deviation based on the corner pressure detection values ​​and reads the vibration amplitude output by the vibration sensor;

[0117] Only when all four lifting mechanisms reach the target height, the maximum height difference at the four corners is less than the first height difference threshold, the diagonal height difference is less than the second height difference threshold, the pressure deviation at the four corners is less than the pressure deviation threshold, the vibration amplitude is less than the vibration threshold, and the above conditions continue until the second preset time threshold, and the safety interlock circuit is not triggered to cut off, will the bottom controller generate the start conditions for allowing rotation internally and output the start signal for allowing rotation to the rotation drive mechanism.

[0118] The four-corner pressure deviation is determined by constructing a spatial moment balance matrix using the four-corner pressure detection values ​​and the coordinates of the lifting support frame's support points, and then solving for the equivalent center of gravity's eccentricity relative to the geometric center. The vibration amplitude is calculated using the difference between the peak and valley values ​​of the vibration sensor output within the current stability confirmation window, or by using the root mean square value of the vibration acceleration signal within the current stability confirmation window as a preset amplitude equivalent to the strength of the same vibration. The calculation formula is as follows:

[0119]

[0120] in, Let be the root mean square value of the vibration acceleration signal, and N be the number of sampling points within the window. These are the vibration acceleration values ​​at each sampling point;

[0121] The first height difference threshold, the second height difference threshold, the pressure deviation threshold, the vibration threshold, and the second preset time threshold are all pre-configured based on the size of the support frame, the allowable tilt amount, the rated load, and the allowable disturbance range before rotation, and are fixed and stored after the equipment is debugged. Different parameter groups can be called for different material types, but only one set of selected parameters is used during the execution of the same task to avoid frequently switching the judgment boundary during the stability confirmation period.

[0122] In this embodiment, the first height difference threshold is 5 mm, the second height difference threshold is 5 mm, the pressure deviation threshold is 10% of the arithmetic mean of the four corner pressure detection values, the vibration threshold is 0.5 m / s², and the second preset time threshold is 2 seconds. The calibration method for the above parameters is as follows: first, a no-load lifting test is conducted to measure the inherent vibration of the mechanism and the noise level of height measurement; then, a rotation test is conducted under rated load. The condition that no measurable slippage of the material occurs during rotation is considered as qualified. The steady-state distribution of the maximum height difference at the four corners, the diagonal height difference, the pressure deviation at the four corners, and the vibration amplitude under qualified working conditions is statistically analyzed. The upper limit of the steady-state distribution is taken and a safety margin of one time is retained to determine the corresponding threshold. The vibration amplitude in the vibration threshold and the root mean square formula of vibration amplitude use the same physical quantity, which is the root mean square value of the vibration acceleration signal.

[0123] The start conditions for allowing rotation are generated according to a fixed control flow: the underlying controller sequentially performs target height arrival judgment, attitude difference judgment, pressure deviation judgment, vibration amplitude judgment, and safety interlock status judgment in each sampling period; only when all five judgments are true within the same sampling period will the stable continuous timer be incremented by one sampling period.

[0124] When any judgment is not true, the stable continuous timer is cleared and restarted; when the accumulated value of the stable continuous timer reaches the second preset time threshold, the underlying controller outputs a rotation permission signal; thus, being continuously greater than or equal to the second preset time threshold corresponds to meeting all conditions within multiple consecutive sampling periods, rather than a delayed output after meeting the conditions once.

[0125] If any condition is interrupted during the stability confirmation period, such as a certain angular displacement continuing to change causing the diagonal height difference to increase again, or the vibration amplitude exceeding the vibration threshold again, the bottom controller cancels the rotation permission state for this cycle, continues to maintain the lifting position, and remeasures the stability continuity condition.

[0126] If the safety interlock circuit is triggered to disconnect during this period, the underlying controller will no longer output a rotation permission signal; through this arrangement, the determination of rotation start no longer depends on a single position signal, but is based on the fact that height, attitude, force and vibration all meet the conditions.

[0127] The pressure detection values ​​at the four corners are not only used to confirm stability, but also to distinguish between off-center load and pressure detection anomalies. After the total pressure of the four lifting mechanisms reaches the pre-configured total load pressure threshold, the bottom controller considers that the material has formed an effective load. At this time, the pressure deviation at the four corners is calculated based on the pressure detection values ​​of each lifting mechanism, and the off-center load is determined accordingly.

[0128] If the pressure deviation at the four corners is greater than or equal to the preset deviation threshold, the underlying controller will retain this information as the basis for subsequent lifting speed limit and rotation speed selection.

[0129] The total load pressure threshold is preferably determined by using the sum of the pressures at the four corners measured under no-load conditions as a benchmark, and then superimposing the minimum incremental load used to characterize the effective load-bearing capacity.

[0130] The off-center load condition can be divided into permissible off-center load, restricted off-center load, and prohibited rotational off-center load according to the comparison results of the pressure deviation at the four corners and the preset off-center load classification boundary. Among them, the restricted off-center load is used to trigger subsequent speed reduction control, and the prohibited rotational off-center load is used to prevent entering the rotation stage.

[0131] The determination of the off-center load condition is performed in a fixed order: first, the total pressure at the four corners is calculated and compared with the total load pressure threshold; after the total pressure reaches the total load pressure threshold, the pressure deviation at the four corners is calculated; the pressure deviation at the four corners is compared with the pre-configured first off-center load boundary and second off-center load boundary; when the pressure deviation at the four corners is less than the first off-center load boundary, it is determined to be an allowable off-center load.

[0132] When the pressure deviation at the four corners is greater than or equal to the first off-center load boundary and less than the second off-center load boundary, it is determined to be a restricted off-center load; when the pressure deviation at the four corners is greater than or equal to the second off-center load boundary, it is determined to be a prohibited rotational off-center load.

[0133] The control result corresponding to restricted off-center load is to keep the current task running but call a lower speed gear, and the control result corresponding to prohibited rotation off-center load is to allow the current lifting to be completed safely without generating a rotation permission signal;

[0134] On the other hand, when the total pressure has not yet reached the total load pressure threshold, the bottom controller does not use the four corner pressure deviation to determine the off-center load, but instead matches and checks the pressure change rate of each lifting mechanism with the corresponding displacement change rate.

[0135] To eliminate the influence of the different dimensions of pressure and displacement values ​​on the comparison results, the pressure change rate and displacement change rate are obtained by dividing the change in adjacent sampling periods by the range of the pressure sensor and the effective range of the displacement sensor, respectively, thus converting them into pure dimensionless change rates.

[0136] The underlying controller compares the absolute difference between the two dimensionless rates of change with a preset matching threshold; the pressure sensor range, displacement sensor effective range, sampling period and matching threshold are all pre-stored in the control system memory, and the same conversion and comparison rules are used for the four lifting mechanisms during operation;

[0137] If the absolute difference of any lifting mechanism exceeds the preset matching threshold, it indicates that the pressure feedback of that angle is inconsistent with the change in lifting. The bottom controller will determine that the angle is abnormal in pressure detection and stop automatic operation. In order to avoid misjudgment caused by fluctuation of a single sampling point, it is preferable to determine that the pressure detection is abnormal only when the preset matching threshold is exceeded in multiple consecutive sampling cycles.

[0138] For multiple consecutive sampling periods, a fixed counting method is preferred: the bottom-level controller sets an abnormal count value for each lifting mechanism. When the dimensionless absolute difference between the pressure change rate and the displacement change rate of the lifting mechanism exceeds the preset matching threshold in a certain sampling period, the corresponding abnormal count value is incremented by one; when the difference does not exceed the preset matching threshold, the corresponding abnormal count value is cleared to zero.

[0139] When the abnormal count value of any lifting mechanism reaches the pre-configured number of abnormal confirmations, the bottom controller determines that the pressure detection of the lifting mechanism is abnormal and stops automatic operation; after stopping, the lifting reversing device maintains the current safe state and does not continue to enter the formal lifting or rotation.

[0140] The number of abnormal confirmations, total load pressure threshold, first off-center load boundary and second off-center load boundary are preferably preset according to the pressure sensor resolution, the rated load of the lifting mechanism and the allowable off-center load range of the material.

[0141] For equipment with different rated loads, parameter groups can be stored separately according to the equipment model. During operation, the underlying controller calls the same group as the current equipment to ensure that the same load reference is used for total pressure judgment, off-center load classification and abnormality confirmation.

[0142] In this embodiment, the total load pressure threshold is the sum of the four corner pressures under no-load conditions and the minimum incremental load of 2000 N. The minimum incremental load corresponds to the minimum load increment required for the bottom surface of the material to completely detach from the conveying surface. The first off-center load boundary is 15% of the arithmetic mean of the four corner pressure detection values, and the second off-center load boundary is 30% of the arithmetic mean of the four corner pressure detection values. The preset matching threshold is 0.05, and the number of abnormal confirmations is 3. The pressure deviation threshold, the first off-center load boundary, and the second off-center load boundary all use the same physical quantity, the four corner pressure deviation, for comparison. The four corner pressure deviation is uniformly represented by the equivalent centroid eccentricity obtained by solving the spatial moment balance matrix. The three constitute the same numerical system from small to large, that is, the pressure deviation threshold is less than the first off-center load boundary, and the first off-center load boundary is less than the second off-center load boundary.

[0143] During normal lifting, the weight of the material is gradually transferred to the four lifting mechanisms. The total pressure at the four corners reaches the lifting height and thus the total load pressure threshold before the four lifting mechanisms. Therefore, the off-center load determination is completed before the rotation permission determination. If the four lifting mechanisms have reached the lifting height but the total pressure has not yet reached the total load pressure threshold, it means that the material has failed to form an effective load. At this time, the pressure deviation condition at the four corners in the rotation permission determination does not take effect independently. The bottom controller then performs a matching check of the pressure change rate and the displacement change rate, and uses the pressure detection anomaly determination result as the basis for whether to stop automatic operation.

[0144] A mutual exclusion mechanism is set between the determination of prohibited rotation and the determination of permitted rotation. When the underlying controller determines that the material is in the state of prohibited rotation and unbalanced load, the underlying controller will not output a permission signal for rotation, regardless of whether the five conditions for permission for rotation are met at the same time. That is, the result of the unbalanced load classification takes precedence over the determination of permission for rotation. When the material is in the state of permitted unbalanced load, the determination of permission for rotation is executed normally. When the material is in the state of restricted unbalanced load, the determination of permission for rotation continues to be executed, but the restricted rotation mode is called after the rotation is started.

[0145] In this implementation, the bottom-level controller completes three interconnected processes at the reversing station of the roller conveyor line: first, it adjusts the lifting speed of the four corners using the average height difference; then, it uses the height difference, pressure deviation, and vibration value to determine whether rotation is allowed; and it handles pressure abnormality and off-center load identification before and after effective load formation. Thus, when the reversing station receives heavy materials, it can first complete the posture adjustment of the support frame and then complete the pre-rotation confirmation.

[0146] In a preferred embodiment of the invention, the bottom controller fits the tilt angle of the lifting support frame based on the height values ​​of the four lifting mechanisms. And based on the friction coefficient of the corresponding material type obtained from the pre-configured control system memory. Rotation radius of the lifting support frame Angular velocity of the rotary drive mechanism and pre-configured system security factor Calculate material slip risk The calculation formula is:

[0147]

[0148] in, To mitigate the risk of material slippage, For system safety factor, Angular velocity, The radius of rotation of the lifting support frame. It is the acceleration due to gravity. The coefficient of friction, The tilt angle of the lifting support frame; a first preset threshold and a second preset threshold are preset, and the first preset threshold is less than the second preset threshold;

[0149] Material slip risk When the first set threshold is reached, rotate at the current angular velocity; when the first set threshold is reached... When setting the second threshold, reduce angular velocity and angular acceleration;

[0150] when When the second threshold is set, the speed is reduced and stopped. If the material edge detection sensor detects that the material exceeds the preset boundary of the lifting support frame, the material will reverse slowly and return to the initial position. If the material does not exceed the threshold, the material will remain in the original position.

[0151] The bottom-level controller controls the lifting and reversing device in the following order:

[0152] After the material is in place, synchronous lifting is performed; once the target height is reached and stability is confirmed, rotation is started; once the rotation reaches the rotation angle, the brake is triggered to complete braking.

[0153] After the rotation is completed, when the outlet detection sensor has not detected an obstruction signal for a period of time greater than or equal to the third preset time threshold, the main controller determines that the discharge channel is empty and issues a start discharge command.

[0154] The bottom-level controller detects that the pressure drop at the four corners is greater than or equal to the set unloading threshold, the displacement at the four corners reaches the preset initial position and the descent is complete, and the detection switch is triggered. After confirming that the load has been transferred and the lifting mechanism has retreated to the preset height range, the controller starts the discharge conveyor mechanism.

[0155] The heavy-duty material reversing system also includes an emergency stop switch, an upper limit switch, a lower limit switch, and a rotary limit switch. The safety interlock circuit directly collects signals from the emergency stop switch, the upper limit switch, the lower limit switch, the rotary limit switch, the anti-intrusion detection switch, and the alarm port of the driver.

[0156] When communication between the main controller and the underlying controller is interrupted, the underlying controller is prohibited from entering the next action phase and performs the corresponding action according to the current phase: if it is in the lifting phase, it performs synchronous descent to the initial position; if it is in the rotation phase, it triggers the brake to perform position holding.

[0157] If the device is in the descent phase, it will continue to descend synchronously to the initial position. After the fault is cleared, the material position, mechanism position, and safety conditions must be reconfirmed by the sensors. The device can only be operated after the restart conditions are met.

[0158] Based on historical operation records of corner height differences, corner pressure deviations, vibrations, drive currents, and anomaly records, the main controller adjusts the lifting speed, rotation speed, and stabilization time for subsequent similar tasks with the same material type and reversing angle.

[0159] When the historical operation record shows an overcurrent abnormality caused by the drive current exceeding the rated value or a slip warning indicating that the risk of material slippage is greater than the first set threshold, the main controller reduces the lifting speed and rotation speed and extends the stabilization time after reaching the target height when generating reversing control commands for subsequent similar tasks. At the same time, it records the speed parameters, time parameters and triggering reasons before and after the adjustment in the memory.

[0160] In this embodiment, the underlying controller first reads the height values ​​of the four lifting mechanisms in each sampling period, calculates the average height difference between two sets of opposite sides in a fixed order, and then converts it into an inclination angle. ;

[0161] coefficient of friction Prioritize the use of the basic friction coefficient for the corresponding material type. If there are multiple candidate values ​​for the same material type, take the minimum value as the calculation value for the current task.

[0162] Rotation radius The system safety factor is determined by the structural parameters of the lifting support frame. The coefficients are fixed and greater than 1; the underlying controller first determines the denominator term before calculation. If the value is greater than the preset lower limit, and not greater than the lower limit, then the slippage risk is directly reduced. It is treated as exceeding the second set threshold to avoid denominator distortion;

[0163] The physical meaning of the denominator g·μ·cosθ−g·sinθ is the maximum equivalent frictional constraint acceleration that the material can obtain along the rotational tangential direction on the inclined support frame surface. When the tilt angle increases or the friction coefficient decreases, causing this denominator to approach zero, the material is in a critical slip state, and the slip risk approaches infinity. The preset lower limit value corresponds to this denominator term and is used to identify this critical state. In this embodiment, the preset lower limit value is 0.5 m / s², which is approximately 5% of the gravitational acceleration. The system safety factor is 1.3, with a value range of 1.2 to 1.5. The first set threshold is 0.6, and the second set threshold is 0.9. The friction coefficient is pre-determined based on the combination of the material of the bottom surface of the material and the material of the support frame surface. The typical friction coefficient between the steel support frame and the bottom surface of the wooden pallet is 0.4 to 0.6, and the typical friction coefficient between the steel support frame and the bottom surface of the plastic is 0.2 to 0.4. When there are multiple candidate values ​​for the same material type, the minimum value is taken for calculation to make the slip risk assessment result more conservative.

[0164] The first and second preset thresholds are stored fixedly according to risk levels from low to high. The underlying controller only determines the thresholds based on... The corresponding action level is invoked within the specified interval, and no new threshold is generated temporarily.

[0165] Rotating at the current angular velocity, reducing angular velocity and angular acceleration, and decelerating to stop all correspond to a pre-configured action table. The underlying controller selects only the currently valid gear from the action table in each sampling cycle and keeps the acceleration change continuous when switching angular velocities to avoid sudden changes during the rotation phase.

[0166] like When entering a restricted area from a low-risk area, the underlying controller first maintains the current rotation direction unchanged, only reducing the angular velocity and angular acceleration; if Upon further entering the stopping zone, the deceleration is initially based on the preset maximum anti-slip angle. The formula for calculating angular deceleration during controlled deceleration is:

[0167]

[0168] in, The preset maximum anti-slip angle deceleration, It is the acceleration due to gravity. The coefficient of friction, The tilt angle of the lifting support frame, The radius of rotation of the lifting support frame;

[0169] The underlying controller outputs a braking command corresponding to the deceleration until the angular velocity of the rotary drive mechanism drops to zero, and then locks the output of the rotary drive mechanism.

[0170] Calculate the average height difference between the two sets of opposite sides in a fixed order, and then convert it into an angle of inclination. The preferred method includes: first, calculating the difference between the average height of a pair of support positions on the inlet side and the average height of a pair of support positions on the outlet side; then, calculating the difference between the average height of a pair of support positions on the left side and the average height of a pair of support positions on the right side; and dividing the two height differences by the known distance between the two support positions in the corresponding direction to obtain the inclination in the two directions.

[0171] The underlying controller takes the tilt angle corresponding to the largest absolute value as the tilt angle of the current sampling period. Alternatively, when both are within acceptable limits, the equivalent tilt angle resulting from the combination of the two can be taken as the tilt angle θ of the current sampling period using the space vector synthesis formula. The calculation formula is as follows:

[0172]

[0173] in, This is the equivalent tilt angle after synthesis. and These are the inclination angles from the inlet to the outlet and from the left to the right, calculated based on the support position spacing, respectively;

[0174] The selection of the two tilt angle acquisition paths mentioned above is based on a preset tilt angle limit, which is 3 degrees in this embodiment. When either the tilt angle from the inlet to the outlet side or the tilt angle from the left to the right side is greater than or equal to the preset tilt angle limit, the tilt angle corresponding to the largest absolute value is taken as the tilt angle of the current sampling period to directly reflect the most severe unidirectional tilt state. When both are less than the preset tilt angle limit, the equivalent tilt angle is calculated using the spatial vector synthesis formula to reflect the comprehensive tilt state of the support frame. Under the condition that both are less than the preset tilt angle limit, the calculation results of the two paths deviate by no more than 5%, which does not affect the judgment conclusion of the slip risk classification.

[0175] In this embodiment, the geometric definitions of the four support positions are consistent across the two sets of height difference algorithms. Taking the geometric center of the lifting support frame as the origin, the four support positions are the left support position at the entrance, the right support position at the entrance, the left support position at the exit, and the right support position at the exit. The two sets of diagonals are the lines connecting the left support position at the entrance and the right support position at the exit, and the lines connecting the right support position at the entrance and the left support position at the exit. The rotation permission determination uses the two sets of diagonal height differences, and the slip risk calculation uses the two sets of average height differences of opposite sides. There is a definite conversion relationship between the two: the height difference between the left support position at the entrance and the right support position at the exit is equal to the sum of the average height difference of opposite sides in the entrance and exit directions and the average height difference of opposite sides in the left and right directions; the height difference between the right support position at the entrance and the left support position at the exit is equal to the difference between the average height difference of opposite sides in the entrance and exit directions and the average height difference of opposite sides in the left and right directions. The two sets of diagonal height differences are the absolute values ​​of the calculation results of the above two equations. Therefore, the support frame attitude evaluated by the two algorithms within the same sampling period is the same attitude, and there will be no contradictory evaluation results due to different support position grouping methods.

[0176] The spacing between support positions is a fixed parameter of the lifting support frame structure, which is pre-stored in the control system memory and determined according to the equipment specifications;

[0177] coefficient of friction System security factor The first set threshold, the second set threshold, and the preset lower limit value are preferably pre-set and stored based on the material bottom surface material, the surface material of the support frame, the upper limit of the target rotation speed, and the allowable sliding margin.

[0178] For different material types, there is a set of basic friction coefficients and threshold parameters in the memory. At the start of the task, the main controller selects one of the sets according to the task information and keeps it unchanged in the same rotation task.

[0179] After deceleration and stopping, the underlying controller further calls the detection results of the material edge detection sensor and combines them with the relative position of the current support frame edge and the outer edge of the material to determine whether it has crossed the boundary.

[0180] If the material is detected to exceed the safety boundary of the lifting support frame, the controller will cause the rotary drive mechanism to reverse at low speed and return to the initial position; if it does not exceed the safety boundary, it will remain in the original position and wait for further processing.

[0181] If the material type corresponding to the friction coefficient cannot be obtained from the memory within a certain cycle, the underlying controller will not increase the speed level, but will maintain the current low speed condition or stop accelerating, thereby avoiding continuing to run at the original rotation speed when the material type is unclear; the safety boundary is preferably determined by the minimum safety margin reserved by the outer edge of the material relative to the edge of the lifting support frame;

[0182] When the material edge detection sensor detects any edge position that intrudes into the area corresponding to the minimum safety margin, it is determined that it exceeds the safety boundary of the lifting support frame;

[0183] The low-speed reverse return to the initial position is executed according to a fixed control flow: After the bottom controller outputs the deceleration and stop command, it first maintains the current position detection before braking and reads the status of the material edge detection sensor; when the detection result shows that the material exceeds the safety boundary of the lifting support frame, it calls the pre-stored low-speed reverse gear and switches the target angle to the angle corresponding to the initial position.

[0184] When the detection result shows that the material has not exceeded the safety boundary, the braking state is maintained and the reversal process is not entered again; the initial position corresponds to the starting angle value recorded before the start of the rotation of this task;

[0185] The action table preferably includes at least a normal rotation gear, a restricted rotation gear, a deceleration stop gear, and a reverse low speed gear. Each gear has a pre-stored upper limit of angular velocity, upper limit of angular acceleration, and braking trigger conditions.

[0186] In this embodiment, the upper limit of angular velocity for the normal rotation gear is 30 degrees per second, and the upper limit of angular acceleration is 20 degrees per second squared; the upper limit of angular velocity for the restricted rotation gear is 15 degrees per second, and the upper limit of angular acceleration is 10 degrees per second squared; the deceleration stop gear performs controlled deceleration with the maximum anti-slip angular deceleration; the upper limit of angular velocity for the reverse low speed gear is 5 degrees per second, and the upper limit of angular acceleration is 5 degrees per second squared; the upper limit of angular velocity for each gear is pre-calculated based on the rotation radius, the minimum friction coefficient, and the maximum anti-slip angular deceleration, that is, the upper limit of angular velocity for the normal rotation gear is obtained by inverse solving the angular velocity obtained when the material slip risk equals the first set threshold, and is gradually reduced according to a preset ratio to form the upper limit of angular velocity for the restricted rotation gear and the reverse low speed gear.

[0187] If multiple triggering conditions are met simultaneously within the same sampling period, the action gear with the highest risk level is used as the only output gear for that period, thus creating a clear sequential mapping relationship between slip risk judgment, stop control, and reverse retreat.

[0188] The bottom controller controls the lifting and reversing device in a fixed sequence; synchronous lifting is performed after the material is in place; rotation is started after the target height is reached and stability is confirmed.

[0189] After the rotation reaches the target angle, the brake is triggered to complete the braking. After the rotation is completed, the main controller continuously reads the outlet detection sensor. When the outlet detection sensor does not detect an obstruction signal for a continuous period of time greater than or equal to the third preset time threshold, it determines that the discharge channel is idle and issues a start discharge command.

[0190] After the start discharge command is sent to the bottom controller, the bottom controller does not immediately start the discharge conveyor mechanism. Instead, it first controls the lifting mechanism to descend and comprehensively confirms that the load has been transferred from the lifting support frame to the discharge conveyor mechanism and that the lifting mechanism has retreated to a safe height based on whether the pressure drop at the four corners is greater than the set unloading threshold, whether the displacement at the four corners has reached the initial position, and whether the descent detection switch has been triggered.

[0191] The pressure drop at the four corners is represented by the absolute drop value of the difference between the sum of the pressure at the four corners in the current sampling period and the sum of the pressure at the four corners in the stable bearing stage. The displacement at the four corners reaching the initial position is represented by the fact that the current positions of the four lifting mechanisms have all returned to their respective initial positions within the allowable error band. The descent detection switch is used to provide confirmation of arrival independent of the displacement sensor.

[0192] Only when the above conditions are met will the bottom controller start the discharge conveyor mechanism to make the material leave the reversing station; the third preset time threshold is used to filter out short-term fluctuation signals from the outlet detection sensor, and its value is preset according to the length of the discharge channel, the running cycle of the discharge conveyor mechanism and the sensor response time.

[0193] The unloading threshold is set according to the difference between the total pressure at the four corners recorded during the stable bearing stage and the total pressure at the four corners during the no-load stage, which is determined as a preset proportion to confirm that the weight of the material has been mainly transferred to the discharge conveyor mechanism.

[0194] In this embodiment, the third preset time threshold is 2 seconds, preferably ranging from 1 to 5 seconds. Specifically, it is determined by dividing the length of the discharge channel by the rated linear speed of the discharge conveying mechanism, and is not less than ten times the response time of the outlet detection sensor. The preset ratio in the unloading threshold is set to 80%, that is, when the pressure drop at the four corners reaches 80% of the total pressure difference between the four corners in the stable bearing stage and the no-load stage, it is determined that the weight of the material has been mainly transferred to the discharge conveying mechanism.

[0195] Retreating to a safe height means that all four lifting mechanisms have descended to a preset height range that does not interfere with the material discharge process. This height range is defined by the position of the descent detection switch and the clearance between the mechanisms.

[0196] The main controller uses a continuous timing method to determine whether the discharge channel is idle: when the outlet detection sensor outputs an unobstructed signal, the main controller increments the idle duration; when the outlet detection sensor outputs an obstruction signal again, the idle duration is reset to zero and the timing restarts.

[0197] The main controller issues a start-up command for material discharge only when the idle duration reaches the third preset time threshold; the underlying controller also confirms the load transfer in a fixed sequence.

[0198] First, compare whether the pressure drop at the four corners is greater than the set unloading threshold, then determine whether the displacement at the four corners has reached the initial position, and then determine whether the descent detection switch has been triggered; only when all three conditions mentioned above are met will the control signal to start the discharge conveyor be output.

[0199] If the outlet detection sensor detects an obstruction again while waiting for the discharge authorization, the main controller will maintain the discharge prohibition state and will not issue a discharge start command; if the pressure drop at the four corners does not reach the set unloading threshold during the descent, it means that the load has not been transferred. The bottom controller will continue to maintain the descent control or pause at the current position until the conditions are met again.

[0200] The pressure drop at the four corners is calculated using the sum of the pressure at the four corners or the pressure values ​​at each corner recorded during the stable bearing stage at the previous moment as a comparison benchmark. This is used to reflect the degree of load reduction after the load is transferred from the lifting bearing frame to the discharge conveying mechanism.

[0201] In this embodiment, the discharge channel and the discharge conveying mechanism respectively represent the channel space area and the corresponding conveying equipment. The former is used to determine whether it is empty or obstructed, and the latter is used to perform the conveying action. Both are used according to this fixed meaning; this can avoid starting the discharge prematurely before the material has fallen correctly into the discharge conveying mechanism.

[0202] The safety interlock circuit directly collects signals from the emergency stop switch, upper limit switch, lower limit switch, rotary limit switch, anti-intrusion detection switch, and driver fault output terminal; the signals of this circuit can take effect without depending on the communication status between the main controller and the underlying controller;

[0203] Meanwhile, if a communication interruption occurs between the main controller and the underlying controller, the underlying controller will be prohibited from entering the next action phase and will perform the corresponding processing according to the current phase. If the communication interruption occurs in the lifting phase, the synchronous descent to the initial position will be executed. If it occurs in the rotation phase, the brake will be triggered to maintain the position. If it occurs in the descent phase, the synchronous descent to the initial position will continue.

[0204] Prohibiting entry into the next action phase means that the underlying controller stops receiving or executing new phase switching commands, but continues to execute the safety handling actions already determined in the current phase until the corresponding safety state is reached;

[0205] The position holding of the rotation link is preferably achieved by the brake action in conjunction with the zero speed setting or the brake holding after the drive is deactivated. The synchronous descent of the lifting link and the lowering link is continuously executed based on the four corner position feedback valid in the previous sampling period as the closed loop basis.

[0206] In this embodiment, the safety interlock circuit is preferably constructed using a safety relay. The normally closed contacts of the emergency stop switch, upper limit switch, lower limit switch, rotary limit switch, and anti-intrusion detection switch are connected in series and then connected to the input circuit of the safety relay. The driver alarm port is connected in series with the same input circuit in the form of a normally closed contact. The output contacts of the safety relay are connected in series in the coil circuit of the main power supply contactor of each driver. When any normally closed contact is opened, the safety relay is activated, the contactor coil is de-energized, and the power supply to the drivers of the four lifting mechanisms and the rotary drive mechanism is directly cut off. The safety interlock circuit is powered by a 24V DC independent power supply, which is isolated from the power supply circuits of the main controller and the bottom controller. The brake is preferably an electromagnetic de-energized brake with a brake response time of no more than 100 milliseconds, which automatically engages when power is cut off or the enable is deactivated.

[0207] After the fault is cleared, the system does not resume operation directly from the steps before the interruption. Instead, it reconfirms the material position, mechanism position, and safety conditions through sensors. The restart conditions are met only when it is confirmed that the material is still in a processable position, the lifting mechanism and rotating mechanism are in an allowable state, and the safety interlock circuit is not triggered. If the reconfirmation fails, the system remains in a stopped state, waiting for manual handling or a new task process.

[0208] The main controller adjusts parameters for similar tasks based on historical operation records; the main controller saves records of the four corner height differences, four corner pressure deviations, vibrations, drive currents and abnormalities from previous tasks, and categorizes them according to material type and reversing angle;

[0209] For subsequent tasks with the same material type and the same reversing angle, the main controller retrieves similar historical records when generating reversing control commands. If the historical operation record records an overcurrent abnormality caused by the drive current exceeding the rated value, or a slip warning record that the material slip risk is greater than the first set threshold, the main controller will reduce the lifting speed and rotation speed in subsequent similar tasks and extend the stabilization time after reaching the target height.

[0210] The adjusted speed parameters, time parameters, and corresponding triggering reasons are written into the memory as a reference for generating control instructions for the next similar task; similar tasks are preferably limited to a set of tasks with the same material type, the same target angle, and the same preset weight range.

[0211] When the main controller recalls historical operation records, it prioritizes selecting the most recent consecutive valid task records as the basis for adjustment; the lifting speed and rotation speed, and the stabilization time can be reduced by adjusting the preset parameter levels one by one, each time reducing the speed level or extending the time level by one.

[0212] If no overcurrent anomaly or slip warning occurs in subsequent tasks, the main controller maintains the adjusted parameters and does not immediately reverse back to the previous gear.

[0213] For subsequent adjustments to similar tasks, a fixed filtering and generation rule is adopted: the main controller first filters out task records with the same material type and the same reversing angle from the historical operation records, and then determines whether there are overcurrent abnormalities or slip warnings in these records;

[0214] If present, lower the current task's lifting speed setting by one level, lower the rotation speed setting by one level, and raise the stabilization time setting by one level.

[0215] If it does not exist, the current parameter level will be maintained; the level adjustment will be based on the parameter level used in the effective control command of the previous version and will be changed step by step, and the level adjustment judgment will be performed only once each time a control command is generated for a task.

[0216] In this embodiment, the lifting speed and rotation speed are each set to five levels, with the speed difference between adjacent levels being 10% of the base speed. The stabilization time is also set to five levels, with a difference of 0.5 seconds between adjacent levels. Each gear adjustment involves lowering both the lifting speed and rotation speed by one level and raising the stabilization time by one level. The adjusted lifting speed is not less than 50% of the rated lifting speed, and the rotation speed is not less than 50% of the upper limit of the normal rotation speed angular velocity. The most recent consecutive effective task records are selected first, being the last ten.

[0217] The abnormal records in the historical operation records preferably include at least one or more of the following: overcurrent abnormality, slip warning, prohibition of rotational off-center load, and stability confirmation timeout;

[0218] Among them, only task records that are completed and whose sensor status is valid are counted as valid task records. Task records that are terminated due to communication interruption or safety interlock triggering are only used for fault tracing and not as the basis for parameter adjustment. The preset weight range is preferably divided according to the rated weight range corresponding to the material type and selected by the host computer task information or the input weighing result.

[0219] When the same material type and reversing angle correspond to multiple weight ranges, the main controller only calls the historical records consistent with the current weight range to adjust the parameters, so as to avoid mixing the speed and settling time under different load conditions.

[0220] If no similar task record exists in the historical operation records, the main controller generates control commands using pre-configured basic parameters; if a similar record exists but there are no overcurrent anomalies or slip warnings in the record, the current parameter level is maintained and no additional speed reduction is performed.

[0221] With this arrangement, the main controller selects parameters for subsequent tasks based on existing operating records, while not changing the on-site decision-making responsibilities of the underlying controller in the current task.

[0222] The following is a complete numerical example, taking a reversing task with a rated load of 2000 kg, a material of 1200 mm x 1200 mm wooden pallet, and a reversing angle of 90 degrees as an example. The main system parameters are as follows: lifting height 150 mm, lifting speed baseline 40 mm / s, lifting acceleration 20 mm / s², rotation angle 90 degrees, normal rotation angle speed upper limit 30 degrees / s, stabilization time baseline 2 seconds, sampling period 4 milliseconds, first preset time threshold 1 second, second preset time threshold 2 seconds, third preset time threshold 2 seconds, compensation dead zone 2 mm, first height difference threshold 5 mm, second height difference threshold 5 mm, and pressure deviation threshold. The parameters are: 10% of the arithmetic mean of the four corner pressure detection values; vibration threshold: 0.5 m / s²; total load pressure threshold: the sum of the four corner pressures under no-load conditions plus 2000 N; first off-center load boundary: 15% of the arithmetic mean of the four corner pressure detection values; second off-center load boundary: 30% of the arithmetic mean of the four corner pressure detection values; preset matching threshold: 0.05; abnormal confirmation count: 3 times; first warning ratio: 80%; system safety factor: 1.3; first set threshold: 0.6; second set threshold: 0.9; preset lower limit: 0.5 m / s²; rotation radius: 1 meter; friction coefficient: 0.4. The above parameters are written into the control system memory after being measured by no-load calibration and rated load test.

[0223] In this numerical embodiment, when the support frame tilt angle is 1 degree and the rotational angular velocity is 30 degrees per second (0.52 radians per second), the denominator g·μ·cosθ-g·sinθ is approximately 3.75 meters per square second, which is greater than the preset lower limit. The material slippage risk S is approximately 0.094, which is less than the first set threshold of 0.6. The underlying controller calls the normal rotation mode and rotates at the current angular velocity. When the tilt angle increases to 3 degrees due to disturbance, the denominator is approximately 3.40 meters per square second, and the material slippage risk S is approximately... 0.103, still less than the first set threshold; if the friction coefficient drops to 0.2 due to the wet bottom of the material and the tilt angle is 3 degrees, the denominator is about 1.44 meters per second squared, and the material slippage risk S is about 0.243, still below the first set threshold; when the angular velocity increases to 60 degrees per second, or 1.05 radians per second, due to the change in task parameters, and the friction coefficient is 0.2 and the tilt angle is 3 degrees, the material slippage risk S is about 0.99, which is greater than the second set threshold of 0.9, and the bottom controller performs deceleration and stops.

[0224] The overall control process is executed cyclically in the following order: First, the bottom-level controller collects the height values, pressure detection values, drive current, vibration data, and temperature data at a sampling period of 4 milliseconds. Second, the main controller generates reversing control commands based on the task information and collected data, and the bottom-level controller verifies the speed and position parameters in the commands against safety limits. Third, after the material arrival signal continuously reaches the first preset time threshold and the rotation area and discharge channel are cleared, the inlet conveyor mechanism stops and contact judgment lifting is performed. Fourth, formal lifting begins, and the speeds of the four lifting mechanisms are adjusted according to the differential speed compensation strategy. Fifth, after reaching the target height, stability confirmation of five conditions is performed. Sixth, after stability confirmation, rotation is started, and the action gear is called according to the material slippage risk level. Seventh, after rotation is completed, the brake is triggered, and the discharge channel is confirmed to be clear. Eighth, synchronous descent is performed, and the discharge conveyor mechanism is started after load transfer is confirmed. If the safety interlock circuit is triggered in any step, the power supply to the driver is directly cut off and the current process is terminated.

[0225] Comparative tests were conducted on the above numerical embodiments. Under the same 2000 kg off-center load condition, without differential speed compensation and multi-sensor fusion confirmation, the maximum height difference at the four corners during the lifting process reached 12 mm. Material slippage warnings occurred an average of 17 times every 500 reversals during the rotation phase, and premature shutdowns due to single-point false detections occurred an average of 9 times every 500 reversals. After enabling differential speed compensation, multi-sensor fusion confirmation of position and clearance, and slippage risk classification control in this embodiment, the maximum height difference at the four corners converged to within 3 mm with a convergence time of no more than 2 seconds. Material slippage warnings decreased to an average of 2 times every 500 reversals, premature shutdowns decreased to 0 times, and no false starts occurred during the recovery confirmation process after communication interruption and safety interlock triggering.

Claims

1. A heavy-duty material reversing system based on four-corner synchronous lifting, applied to a logistics channel including an inlet conveying mechanism, an outlet channel, an outlet conveying mechanism, a reversing station, and a rotating area, characterized in that, include: The lifting and reversing device is arranged at the reversing station and includes four independently speed-adjustable lifting mechanisms, a lifting support frame, a rotary drive mechanism, a brake, a limit switch, a driver, and a driver alarm port. The detection device, arranged on the reversing station, the rotating area and the lifting reversing device, includes a displacement sensor, a pressure sensor, a current sensor, a vibration sensor, a temperature sensor and an anti-intrusion detection switch. The control system is communicatively connected to the detection device, the inlet conveying mechanism, the outlet conveying mechanism, and the lifting and reversing device. The control system includes a main controller and a lower-level controller. The main controller generates a reversing control command containing lifting height, rotation angle and speed control quantities based on the task information of the host computer and the data collected by the detection device, sends it to the bottom controller, and sends a start command to the material conveying mechanism. The bottom-level controller receives the commutation control command and outputs a drive signal to the lifting commutation device; The safety interlock circuit is independent of the main controller and the bottom controller. The input terminal of the safety interlock circuit is connected to the limit switch and the alarm port of the driver. The output terminal of the safety interlock circuit is connected in series with the power supply circuit of the driver of the lifting reversing device.

2. The heavy-duty material reversing system based on four-corner synchronous lifting according to claim 1, characterized in that, The detection device also includes an inlet detection sensor, a workstation detection sensor, a material edge detection sensor, an outlet detection sensor, and a descent position detection switch; The detection device uses the inlet detection sensor, the station detection sensor, and the material edge detection sensor to jointly confirm that the front end of the material enters, the main body is located on the lifting support frame, and the tail end passes the inlet detection sensor. It also uses the outlet detection sensor and the anti-intrusion detection switch to confirm that no object is detected in the rotating area and the discharge channel. When the detection device detects that the material arrival signal is continuously greater than or equal to the first preset time threshold, the control system controls the inlet conveying mechanism to stop and controls the lifting and reversing device to lift until the pressure detection values ​​of the four lifting mechanisms are all greater than zero.

3. The heavy-duty material reversing system based on four-corner synchronous lifting according to claim 1, characterized in that, The main controller is used to determine the lifting speed, rotation speed, lifting acceleration, and stabilization time based on the material type, material arrival status, the reversing station, the unobstructed state of the rotating area and the discharge channel in the upper computer task information, and to generate the reversing control command. The underlying controller is used to verify whether the speed and position parameters in the commutation control command are within the preset safety limit range. If the verification is successful, the commutation control command is executed; if the verification fails, the command is rejected and an alarm signal is fed back.

4. The heavy-duty material reversing system based on four-corner synchronous lifting according to claim 1, characterized in that, The underlying controller uses the lifting height as the lifting reference for the four lifting mechanisms, calculates the difference between the height value of each lifting mechanism and the average height of the four corners, decelerates the lifting mechanism with a height value greater than or equal to the average height of the four corners, and accelerates the lifting mechanism with a height value less than the average height of the four corners. When the pressure detection value of the pressure sensor of the four lifting mechanisms exceeds the preset pressure threshold or the current detection value of the current sensor of the corresponding drive mechanism exceeds the preset current threshold, the bottom controller reduces the acceleration compensation amount for the lifting mechanism whose height value is less than the average height of the four corners.

5. The heavy-duty material reversing system based on four-corner synchronous lifting according to claim 4, characterized in that, The bottom-level controller calculates the maximum height difference at the four corners based on the height values ​​of the four lifting mechanisms, and calculates the diagonal height difference on the two sets of diagonals; The bottom-level controller outputs a signal allowing the rotary drive mechanism to start only when the four lifting mechanisms reach the lifting height, the maximum height difference between the four corners is less than the first height difference threshold, the diagonal height difference is less than the second height difference threshold, the pressure deviation at the four corners is less than the pressure deviation threshold and the vibration amplitude is less than the vibration threshold, and these conditions are continuously greater than or equal to the second preset time threshold, and the safety interlock circuit is not triggered to cut off.

6. The heavy-duty material reversing system based on four-corner synchronous lifting according to claim 1, characterized in that, After the total pressure of the four lifting mechanisms reaches the pre-configured total load pressure threshold, the bottom-level controller calculates the pressure deviation at the four corners based on the pressure detection values ​​of each lifting mechanism, and determines the off-center load state of the material based on the pressure deviation at the four corners. When the total pressure does not reach the total load pressure threshold, if the difference between the pressure change rate and the corresponding displacement change rate of any lifting mechanism is greater than or equal to a preset matching threshold, the bottom-level controller determines that the pressure detection of the lifting mechanism is abnormal and stops automatic operation.

7. The heavy-duty material reversing system based on four-corner synchronous lifting according to claim 2, characterized in that, The bottom-level controller fits the tilt angle of the lifting support frame based on the height values ​​of the four lifting mechanisms. And based on the friction coefficient of the corresponding material type obtained from the pre-configured control system memory. The rotation radius of the lifting support frame Angular velocity of the rotary drive mechanism and pre-configured system security factor Calculate material slip risk The calculation formula is: ； in, The acceleration is due to gravity; a first preset threshold and a second preset threshold are set, and the first preset threshold is less than the second preset threshold; when the material slippage risk... When the first set threshold is reached, rotate at the current angular velocity; When the first set threshold When the second threshold is set, the angular velocity and angular acceleration are reduced; when When the second set threshold is reached, the deceleration stops. If the material edge detection sensor detects that the material exceeds the preset boundary of the lifting support frame, the material reverses at low speed and returns to the initial position. If the material does not exceed the threshold, the material remains in its original position.

8. The heavy-duty material reversing system based on four-corner synchronous lifting according to claim 2, characterized in that, The underlying controller controls the lifting and reversing device in the following order: After the material is in place, synchronous lifting is performed; once the target height is reached and stability is confirmed, rotation is started; once the rotation reaches the specified rotation angle, the brake is triggered to complete braking. After the rotation is completed, the main controller determines that the discharge channel is idle and issues a start discharge command when the outlet detection sensor has not detected an obstruction signal for a continuous period of time greater than or equal to a third preset time threshold. The underlying controller controls the start of the discharge conveyor mechanism after the load transfer is confirmed and the lifting mechanism has retreated to the preset height range, based on the detection switch being triggered when the pressure drop at the four corners is greater than or equal to the set unloading threshold, the displacement at the four corners reaches the preset initial position, and the descent is completed.

9. The heavy-duty material reversing system based on four-corner synchronous lifting according to claim 1, characterized in that, The heavy-duty material reversing system also includes an emergency stop switch, an upper limit switch, a lower limit switch, and a rotary limit switch. The safety interlocking circuit directly collects signals from the emergency stop switch, the upper limit switch, the lower limit switch, the rotary limit switch, the anti-intrusion detection switch, and the driver alarm port. When communication between the main controller and the underlying controller is interrupted, the underlying controller is prohibited from entering the next action phase and performs the corresponding action according to the current phase: if it is in the lifting phase, it performs synchronous descent to the initial position; if it is in the rotation phase, it triggers the brake to perform position holding. If the device is in the descent phase, it will continue to descend synchronously to the initial position. After the fault is cleared, the material position, mechanism position, and safety conditions must be reconfirmed by the sensors. The device can only be operated after the restart conditions are met.

10. The heavy-duty material reversing system based on four-corner synchronous lifting according to claim 7, characterized in that, The main controller adjusts the lifting speed, rotation speed, and stabilization time for subsequent similar tasks with the same material type and reversing angle based on the recorded historical operation records, including the height difference at the four corners, pressure deviation at the four corners, vibration, drive current, and abnormal records. When the historical operation record shows an overcurrent abnormality caused by the drive current exceeding the rated value or a slip warning indicating that the risk of material slippage is greater than the first set threshold, the main controller reduces the lifting speed and rotation speed and extends the stabilization time after reaching the target height when generating reversing control commands for subsequent similar tasks. At the same time, it records the speed parameters, time parameters and triggering reasons before and after the adjustment in the memory.

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