Anti-collision protection system and method for slewing mechanism of bucket wheel machine

Abstract

The invention discloses an anti-collision protection system and method for a slewing mechanism of a bucket wheel machine. The anti-collision protection system comprises a signal detection unit, a control processing unit, a man-machine interaction unit and a slewing execution unit. The signal detection unit collects position signals through a rotary absolute value encoder and a pitching absolute value encoder; and the control processing unit converts the Gray code signal into a binary code through bit-by-bit XOR, sequentially completes data conversion from a bit type to a word type, an integer type and a floating-point number type, and calculates a real-time pitching height value and a real-time rotation angle value in combination with a linear formula. And when the two values do not exceed the preset height threshold value and the preset angle threshold value respectively, the system triggers a protection mode, only allows the slewing mechanism to run in the direction in which the absolute value of the slewing angle is increased, forbids reverse slewing, and prevents the cantilever from colliding with the foundation building. The man-machine interaction unit can switch on and switch off the protection function, and the requirement for low-material-level small-angle material taking is met while safety is guaranteed.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of automatic control and safety protection, and particularly relates to a bucket wheel machine slewing mechanism anti-collision protection system and method. BACKGROUND

[0002] The slewing mechanism of the bucket wheel machine is used to drive the upper slewing part to realize slewing movement around the slewing center line, and is generally composed of a driving device, a transmission device and a slewing bearing. The slewing angle range of the mechanism is generally ±110°, and the included angle between the boom and the center line of the walking track is within ±60° when it is in the normal working area.

[0003] In the actual operation process, when the bucket wheel machine is in a small slewing angle and the luffing mechanism is lowered to a low material level, if it continues to slewing in the direction of reducing the absolute value of the slewing angle, the cantilever front end may collide with the foundation building on both sides of the walking track, and there is a risk of equipment damage and even safety accidents.

[0004] At present, the protection measures commonly configured for the bucket wheel machine include: the slewing mechanism is provided with a left turning limit switch, a right turning limit switch, a cantilever left side anti-collision sensor and a cantilever right side anti-collision sensor; and the luffing mechanism is provided with an upward limit switch and a downward limit switch. The above protection can only prevent the mechanism from exceeding the stroke limit or directly contacting the fixed obstacle, and cannot identify and intervene in the potential collision risk in the small angle and low luffing combined working condition. When the slewing operation is performed in such a working condition, the system still allows slewing because the cantilever has not triggered the physical limit or anti-collision sensor, which is easy to cause the cantilever to interfere with the foundation building.

[0005] Therefore, the prior art has the problems that it cannot dynamically limit the slewing action in the dangerous direction during the low material level and small angle material taking process, and it is difficult to balance the material taking efficiency and equipment safety. SUMMARY

[0006] In order to solve the problems in the background art, the present application provides a bucket wheel machine slewing mechanism anti-collision protection system and method.

[0007] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows: a bucket wheel machine slewing mechanism anti-collision protection system, comprising: a signal detection unit comprising a slewing absolute value encoder and a luffing absolute value encoder; a control processing unit connected with the signal detection unit; a man-machine interaction unit connected with the control processing unit in communication; a slewing execution unit connected with the control output end of the control processing unit; The control processing unit is configured to: Based on the real-time signal from the signal detection unit, the real-time pitch height and real-time yaw angle values ​​are calculated. When the real-time pitch height value is less than or equal to a preset height threshold, and the absolute value of the real-time yaw angle value is less than or equal to a preset angle threshold, the protection mode is triggered. In protection mode, the rotary actuator is controlled so that the rotary mechanism can only run in a direction away from the foundation building of the travel track; The human-computer interaction unit is used to set the preset height threshold and the preset angle threshold, and to output instructions to enable or disable the protection mode. When the instruction is disabled, the control processing unit does not execute the logic of the protection mode.

[0008] Based on the aforementioned anti-collision protection system for the slewing mechanism of a bucket wheel excavator, this invention further proposes an anti-collision protection method for the slewing mechanism of a bucket wheel excavator, comprising the following steps: The raw signals of rotation angle and pitch height are obtained through the signal detection unit.

[0009] The original signal is processed by the control processing unit to obtain the real-time rotation angle value and the real-time pitch height value.

[0010] The preset height threshold and preset angle threshold can be set through the human-computer interaction unit.

[0011] When the real-time pitch height value is less than or equal to the preset height threshold, and the absolute value of the real-time yaw angle value is less than or equal to the preset angle threshold, the protection mode is activated.

[0012] In protection mode, the control slewing actuator only allows the slewing mechanism to move away from the track foundation building.

[0013] Compared with the prior art, the present invention has the following beneficial effects: by converting the Gray code values ​​output by the pitch height measurement encoder and the slewing angle measurement encoder into binary code, and sequentially performing data type conversion from bit type to word type, word type to integer type, and integer type to floating point type, combined with a preset linear mapping formula, the real-time pitch height value and the real-time slewing angle value can be accurately calculated.

[0014] Based on this, when the real-time pitch height value is less than or equal to a preset height threshold, and the absolute value of the real-time slewing angle value is less than or equal to a preset angle threshold, the system automatically triggers a protection mode. In this mode, the slewing mechanism is only allowed to move in the direction where the absolute value of the slewing angle increases, and is prohibited from rotating in the direction where the absolute value decreases. This control logic effectively avoids the collision risk caused by the cantilever rotating towards the foundation building in a low-altitude, small-angle region.

[0015] Meanwhile, the operator can enable or disable this protection function according to actual operational needs via the rotary interlock activation / deactivation button on the human-machine interface unit: when the protection is enabled, the system automatically implements directional restrictions to ensure equipment safety. When the protection is disabled, full manual operation is allowed to meet special working conditions such as low-level precision material handling or debugging.

[0016] Thus, without altering the original mechanical structure, a balance between safety and operational flexibility is achieved, improving the reliability and material handling efficiency of the bucket wheel excavator under complex boundary conditions. Attached Figure Description

[0017] Figure 1 This is a module connection diagram of an anti-collision protection system for the slewing mechanism of a bucket wheel excavator according to the present invention; Figure 2 This is a wiring diagram of the encoder output to the input card of the present invention; Figure 3 This is a flowchart of the Gray code decoding logic of the present invention; Figure 4 This is a diagram illustrating the data type conversion and calculation process for pitch altitude values ​​in this invention. Figure 5 This is a diagram illustrating the data type conversion and calculation process for the rotation angle value in this invention. Figure 6 This is the control logic diagram for prohibiting the descent of the pitch mechanism under the protection mode of this invention; Figure 7 This is the control logic diagram for limiting the rotation direction under the protection mode of this invention. Detailed Implementation

[0018] 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.

[0019] like Figures 1-7 As shown, the technical solution adopted by the present invention is as follows: A collision protection system for the slewing mechanism of a bucket wheel excavator, comprising: The signal detection unit includes a rotary absolute encoder and a pitch absolute encoder.

[0020] The signal detection unit is used to acquire the position information of the slewing mechanism and pitching mechanism of the bucket wheel excavator in real time. The absolute slewing encoder is installed on the slewing mechanism and is used to output a Gray code signal reflecting the current slewing angle.

[0021] The pitch absolute encoder is mounted on the pitch mechanism and is used to output a Gray code signal reflecting the current pitch height.

[0022] The control processing unit is connected to the signal detection unit.

[0023] The control processing unit is used to receive and process the raw Gray code signals from the rotary absolute encoder and the pitch absolute encoder.

[0024] The control processing unit is equipped with a Gray code decoding function block, which converts the Gray code signal into the corresponding binary code signal through bit-by-bit XOR logic operation.

[0025] Subsequently, the control processing unit calls the data type conversion module to sequentially perform operations of concatenating bit type (BIT) into word type (WORD), converting word type (WORD) into integer type (INT), and converting integer type (INT) into floating-point type (REAL), ultimately generating real-time rotation angle value and real-time pitch height value that can be used for logical comparison.

[0026] The human-computer interaction unit is communicatively connected to the control processing unit.

[0027] The human-computer interaction unit is used to provide an interactive interface for operators.

[0028] The human-computer interaction unit is configured to allow users to set preset height thresholds and preset angle thresholds, and to provide instructions to enable or disable the protection mode.

[0029] When the instruction is disabled, the control processing unit does not perform subsequent protection logic judgments and restriction actions, thereby allowing manual intervention under specific operating conditions.

[0030] The rotary execution unit is connected to the control output terminal of the control processing unit.

[0031] The rotary actuator is connected to the control output terminal of the control processing unit and is used to execute rotary motion.

[0032] The rotary actuator includes a frequency converter, a rotary motor, and a mechanical brake that are connected in sequence.

[0033] The control processing unit outputs its direction control command to the start / stop control terminal and direction control terminal of the frequency converter through the control loop, so as to achieve precise limitation of the rotation direction.

[0034] The control processing unit is configured as follows: Based on the real-time signals from the signal detection unit, the real-time pitch height and real-time slewing angle values ​​are calculated. This calculation process forms the basis for the collision avoidance protection logic and accurately reflects the current spatial attitude of the bucket wheel excavator.

[0035] Specifically, the process by which the control processing unit calculates the real-time value based on the real-time signal from the signal detection unit includes a Gray code conversion step: The control processing unit calls the Gray code decoding function block to convert the Gray code signals output by the slewing absolute encoder and the pitch absolute encoder, respectively.

[0036] The conversion is achieved through bitwise XOR logic operations, which convert the Gray code signal into the corresponding binary code signal.

[0037] The Gray code conversion step is used to eliminate the risk of misreading caused by multiple simultaneous transitions of the absolute encoder output signal during state switching, thereby improving the reliability of raw data acquisition.

[0038] The Gray code signal output by the rotary absolute encoder represents the angle information of the current rotary mechanism relative to the reference position, and the Gray code signal output by the pitch absolute encoder represents the height information of the current pitch mechanism relative to the reference position.

[0039] The conversion is achieved through bitwise XOR logic operations, converting the Gray code signal into the corresponding binary code signal: Let the Gray code be... The corresponding binary code is Then there is And for to ,have ,in This represents the XOR operation. This XOR operation ensures that each bit of the binary code is determined by the high-order Gray code and the decoded high-order binary code, thus achieving unambiguous, single-value mapping decoding.

[0040] The calculation process also includes a data type conversion step: The control processing unit calls the data type conversion module to process the binary code signal after Gray code conversion.

[0041] The data processing includes, in sequence: concatenating multiple bit-type data into word-type data, converting the word-type data into integer-type data, and converting the integer-type data into floating-point-type data, ultimately generating the real-time pitch height value and real-time yaw angle value for comparison and calculation.

[0042] The data type conversion step is used to gradually convert the discrete bit signals acquired by the hardware into floating-point values ​​that can be used for engineering quantity calculations and logical comparisons.

[0043] The data processing sequentially includes: concatenating multiple bit-type data into word-type data; in this step, the control processing unit reads several independent bit-type data obtained after Gray code decoding from the signal detection unit. The data is processed and, based on the physical wiring order of the encoder output signals in the input card, combined into a complete word type according to a fixed arrangement rule from high to low or from low to high. The splicing operation aims to restore the complete numerical information of the encoder's original output, ensuring that subsequent processing is based on the complete data frame.

[0044] Subsequently, the character data is converted into integer data; in this step, the control processing unit converts the previously concatenated character data ( ) variables are converted into signed integers according to the system's preset data interpretation rules. ) or unsigned integer ( This transformation converts binary data, which was originally used only to represent state or address, into numerical variables that can be used in mathematical operations, thus enabling them to participate in calculations as input parameters for linear mapping formulas.

[0045] Then convert the integer data to a floating-point data type. In this step, the control processing unit will process integer types ( Variables can be converted to floating-point types through type casting or scaling. The transformation preserves the precision of the decimal part, allowing subsequent calculations based on physical quantities (such as angle or height) to reflect more subtle changes, thus meeting the high precision requirements of the anti-collision protection of the bucket wheel excavator's slewing mechanism for position detection and control response.

[0046] Finally, the real-time pitch height value and real-time yaw angle value are generated for comparison and calculation; wherein, the real-time pitch height value is obtained by formula: ; The calculation shows that, in the formula Alternatively, the lowest elevation (e.g., 0 meters) can be measured on-site. The meter represents the actual distance from the lowest to the highest position of the pitch mechanism, measured on-site. and These are the low-order and high-order code values ​​set for the touchscreen, respectively. This is the current integer value of the pitch encoder after data type conversion.

[0047] The real-time rotation angle value is obtained through the formula: ; The calculation shows that, in the formula and These are the code values ​​set for turning 90° left and 90° right respectively on the touchscreen. This is the current integer value of the rotary encoder after data type conversion. Left turn angle is negative and right turn angle is positive.

[0048] The above formula realizes a linear mapping from the encoder's original code value to physically meaningful engineering quantities (height, angle), ensuring that the real-time pitch height value and the real-time rotation angle value are accurate and comparable, providing a basis for the triggering of subsequent protection modes and directional restrictions.

[0049] When the real-time pitch height value is less than or equal to a preset height threshold, and the absolute value of the real-time yaw angle value is less than or equal to a preset angle threshold, the protection mode is triggered.

[0050] This judgment condition constitutes a dual premise of the protection logic, used to identify dangerous working conditions in which the bucket wheel excavator is prone to collision with the foundation structure of the traveling track.

[0051] The real-time pitch height value is the current cantilever height value calculated by the control processing unit based on the pitch absolute encoder output signal after Gray code conversion and data type conversion. Its unit is meters, reflecting the actual vertical position of the bucket wheel excavator cantilever relative to the reference plane.

[0052] The preset height threshold is a fixed height limit set by the operator through the human-machine interface unit, used to determine whether the low pitch danger zone has been entered. When the real-time pitch height value drops to this threshold or lower, it indicates that the cantilever has approached the top of the foundation building, posing a collision risk.

[0053] The real-time slewing angle value is calculated by the control processing unit based on the output signal of the absolute slewing encoder after Gray code conversion and data type conversion. The unit is degrees, with the track centerline as the reference, left turn is negative and right turn is positive.

[0054] The preset angle threshold is a fixed angle limit set by the operator through the human-machine interface unit, used to define whether the slewing mechanism is in a small angle region close to the foundation building. When the absolute value of the real-time slewing angle does not exceed this threshold, it indicates that the bucket wheel excavator boom is facing or close to the lateral boundary of the foundation building.

[0055] Only when both conditions are met simultaneously—that is, when the bucket wheel excavator is in a low pitch state and within a small slewing angle range—will the control processing unit determine that the equipment has entered a high-risk area and automatically trigger the protection mode. This dual-condition judgment mechanism aims to avoid malfunctions caused by misjudgment based on a single condition, ensuring that the protection mechanism only takes effect when a genuine collision risk exists.

[0056] Once the protection mode is triggered, the system will activate the direction restriction and operation lockout mechanism to prevent the slewing mechanism from moving further toward the foundation building, thereby achieving active collision avoidance.

[0057] In protection mode, the slewing actuator is controlled so that the slewing mechanism can only move in a direction away from the foundation building of the travel track. This control logic dynamically blocks slewing commands in dangerous directions based on the sign of the real-time slewing angle value and its relationship with a preset angle threshold, thereby ensuring that the cantilever movement always tends towards a safe area.

[0058] Specifically, the rotary actuator includes a frequency converter, a rotary motor, and a mechanical brake that are sequentially electrically connected.

[0059] The inverter receives control signals and adjusts the output frequency and voltage to drive the rotary motor to rotate in a specified direction and speed. The rotary motor drives the slewing bearing through the transmission mechanism to realize the slewing motion of the upper structure of the bucket wheel excavator. The mechanical brake automatically engages in the event of power failure or emergency to ensure that the equipment stops stably.

[0060] The output port of the control processing unit is connected to the start / stop control terminal and direction control terminal of the frequency converter through a control loop to output direction control commands.

[0061] This control loop is a hard-wired or programmable logic control path used to accurately transmit the digital signals generated by the control processing unit to the corresponding input terminals of the frequency converter.

[0062] When the real-time slewing angle value is positive and its value is less than or equal to the preset angle threshold, it indicates that the bucket wheel excavator boom is located in the small angle area on the right side of the track. If it continues to turn right (i.e., increase the positive value), it will move away from the foundation building, while turning left (i.e., decrease the absolute value of the angle) will approach the foundation building. Therefore, the control processing unit blocks the control command to turn left and only allows to turn right.

[0063] When the real-time slewing angle value is negative and its absolute value is less than or equal to the preset angle threshold, it indicates that the bucket wheel excavator boom is located in the small angle area on the left side of the track. If it continues to turn left (i.e., more negative), it will move away from the foundation building, while turning right (i.e., reducing the absolute value of the angle) will approach the foundation building. Therefore, the control processing unit blocks the control command for turning right and only allows turning left.

[0064] The direction control command is output to the direction control terminal of the frequency converter through the control processing unit, determining the rotation direction of the rotary motor driven by the frequency converter. Simultaneously, the start / stop control terminal receives start / stop signals, allowing the rotary motion to execute if the rotary conditions are met; otherwise, it forcibly stops the output.

[0065] This control mechanism ensures that during the protection mode activation period, regardless of how the operator operates the slewing handle or button, the slewing actuator cannot perform a slewing action toward the foundation building, fundamentally preventing collision accidents, while retaining the ability to run in a safe direction, balancing material handling efficiency and equipment safety.

[0066] Specifically, the control processing unit's logic for controlling the rotary execution unit in protected mode includes a direction limiting step: If the real-time rotation angle value is positive and its value is less than or equal to the preset angle threshold, then the control command for left rotation is blocked.

[0067] If the real-time rotation angle value is negative and its absolute value is less than or equal to the preset angle threshold, then the control command for right rotation is blocked.

[0068] The direction restriction step is used to dynamically prohibit turning direction commands that may cause a collision, based on the sign and magnitude of the real-time turning angle value.

[0069] If the real-time slewing angle value is positive and its value is less than or equal to the preset angle threshold, it indicates that the bucket wheel excavator boom is currently located to the right of the track centerline and within a small angle range close to the foundation structure. At this time, turning left would reduce the absolute value of the slewing angle, causing the boom to move further towards the foundation structure, posing a collision risk. Therefore, the control processing unit blocks the control command for leftward slewing, i.e., prohibits the output of signals to drive the slewing motor to rotate to the left, thereby preventing dangerous actions.

[0070] If the real-time slewing angle value is negative and its absolute value is less than or equal to the preset angle threshold, it indicates that the bucket wheel excavator boom is currently located to the left of the track centerline and within a small angle range close to the foundation structure. At this time, turning to the right will reduce the absolute value of the slewing angle (even if the negative value approaches zero), which will also cause the boom to move closer to the foundation structure. Therefore, the control processing unit blocks the control command for right slewing, i.e., prohibits the output of signals to drive the slewing motor to rotate to the right, to avoid interference between the equipment and the foundation structure.

[0071] The blocking refers to the control processing unit forcibly setting the control command for the corresponding direction to zero or blocking it at the logic level. Regardless of whether the human-machine interaction unit or the operating handle issues the request for that direction, it will not output a valid level signal to the direction control terminal of the frequency converter, ensuring that the rotary execution unit cannot perform movement in the prohibited direction.

[0072] Specifically, the control processing unit is also configured to execute the protection mode exit step: In protection mode, the real-time pitch height value and real-time yaw angle value are continuously monitored.

[0073] When the real-time pitch height value is detected to be greater than the preset height threshold or the real-time yaw angle value, the protection mode is automatically exited.

[0074] The protection mode exit step is used to automatically restore the omnidirectional operation capability of the slewing mechanism after the dangerous condition is removed, so as to avoid the protection logic continuously restricting the operation of the equipment in unnecessary states.

[0075] In protection mode, the real-time pitch height and real-time slewing angle values ​​are continuously monitored. The control processing unit continuously reads and updates these two key parameters at a set scanning cycle (such as the PLC program cycle) to ensure real-time perception of the bucket wheel excavator's spatial attitude and provide an accurate basis for exit judgment.

[0076] When the real-time pitch height value is detected to be greater than the preset height threshold or the real-time yaw angle value, the protection mode is automatically exited. This judgment uses an "OR" logic relationship, meaning that as long as either condition is met, the collision risk is considered to have been eliminated.

[0077] If the real-time pitch height value is greater than the preset height threshold, it indicates that the cantilever has been raised to a safe height above the foundation building. Even if the rotation angle is small, structural interference will not occur, and therefore directional restrictions are no longer required.

[0078] If the absolute value of the real-time rotation angle is greater than the preset angle threshold, it indicates that the cantilever has rotated to a region far away from the foundation building (for example, the rotation angle exceeds ±30°, while the preset angle threshold is set to ±25°). At this time, regardless of the pitch height, it will not collide with the foundation building, so the protection can be released.

[0079] Automatically exiting the protection mode means that the control processing unit immediately stops executing the direction restriction steps, restores the omnidirectional control command output authority to the slewing execution unit, and allows the operator to freely control left or right turns according to actual needs.

[0080] Specifically, it also includes a hydraulic control system for the pitch mechanism connected to the control processing unit. This hydraulic control system is used to drive the bucket wheel excavator boom to perform pitch movements, and its actuators include hydraulic cylinders, proportional valves, or solenoid directional valves, controlled by command signals from the upper-level control system.

[0081] The control processing unit is further configured to output a control signal to prevent the pitch mechanism hydraulic control system from performing a descent operation when the protection mode is triggered. This control signal is a digital output signal, transmitted via hardwiring or a communication interface to the enable terminal or descent control loop of the pitch mechanism hydraulic control system.

[0082] When the protection mode is triggered, it indicates that the bucket wheel excavator is currently in a high-risk state with a low pitch height and a small slewing angle. If the descent operation is continued at this time, it will further reduce the vertical clearance between the cantilever and the foundation structure of the traveling track, significantly increasing the risk of collision or scratch.

[0083] Therefore, the control processing unit actively cuts off or blocks control commands in the descent direction, so that the pitch mechanism hydraulic control system cannot respond to any descent requests from the operating handle, automatic program or other sources, and only allows the execution of ascent operations or maintaining the current position.

[0084] This prohibition mechanism is implemented by setting a descent enable condition in the control logic: the descent operation is only allowed when the protection mode is not activated. Once the protection mode is activated, the descent enable signal is forcibly set to an invalid state, thereby physically blocking the execution path of the descent action at the hydraulic control level.

[0085] Specifically, before outputting control commands to the slewing execution unit, the control processing unit performs a slewing condition determination step to verify whether the slewing conditions are met.

[0086] The slewing conditions include: both the slewing power switch and the brake fan power switch are in the closed state, and there is no fault signal from the slewing inverter; and the slewing motor is not overloaded or the operation mode selection switch is in adjustment.

[0087] The slewing condition determination step is a safety pre-verification mechanism for slewing operations, used to ensure that the equipment is only allowed to start slewing operations if the electrical, mechanical and control conditions all meet the safety operation requirements.

[0088] The rotary power switch is the main circuit breaker or contactor auxiliary contact that supplies power to the rotary actuator. Its closed state indicates that the rotary drive system is energized. The brake fan power switch is the power supply switch for the fan required to release the mechanical brake. Its closed state ensures that the brake can be released normally, avoiding equipment damage or overload caused by forcibly starting the motor while the brake is not released.

[0089] The fault-free signal of the slewing inverter is generated by the internal self-diagnostic module of the slewing inverter and fed back to the control processing unit through the digital output port. When the inverter detects abnormalities such as overvoltage, overcurrent, overheating, short circuit, or communication interruption, it will output a fault signal. If a fault signal is present, it indicates that there is a potential risk in the slewing drive system, and slewing operation is prohibited to prevent the accident from escalating.

[0090] Furthermore, the rotary motor is not overloaded, or the operating mode selection switch is in the adjustment position. Meeting either of these two sub-conditions is sufficient for the rotary motor to be considered ready for startup.

[0091] Among them, "the rotary motor is not overloaded" means that the motor current detected by the thermal relay, current sensor or the built-in protection function of the frequency converter does not exceed the set threshold, indicating that the motor is within the normal load range.

[0092] When the operation mode selection switch is in the adjustment position, it means that the equipment is currently in maintenance or debugging mode. In this mode, even if there is a slight overload on the rotary motor, manual intervention is allowed to perform jogging or fine-tuning operations to meet the needs of on-site installation, maintenance or calibration.

[0093] Only when all the above-mentioned turning conditions are met simultaneously will the control processing unit determine that the turning conditions are met and continue to output direction and start / stop control commands to the turning execution unit; otherwise, even if the operator issues a turning request, the control processing unit will not output a valid control signal, thereby realizing the safety design of prohibiting action if the conditions are not met.

[0094] The slewing condition determination step is independent of the protection mode logic and belongs to the basic operation permission mechanism, ensuring that the slewing operation is always based on the premise that the equipment itself is safe and controllable, regardless of whether it is in anti-collision protection state.

[0095] The human-computer interaction unit is used to set the preset height threshold and the preset angle threshold, and to output the enable or disable command of the protection mode. When the command is disabled, the control processing unit does not execute the logic of the protection mode.

[0096] The human-machine interaction unit is used to set the preset height threshold and preset angle threshold. This function is implemented through the parameter input interface on the touch screen or operation panel, allowing operators to flexibly configure the critical conditions for triggering the protection mode according to the actual spatial layout of the bucket wheel excavator and the foundation of the traveling track, the material stacking shape, and the operation requirements.

[0097] The preset height threshold is a floating-point number in meters, representing the upper limit of the vertical height of the cantilever pitch mechanism relative to the reference plane. When the real-time pitch height value is less than or equal to this value, the system determines that the equipment has entered a low-altitude danger zone. This preset height threshold needs to be set in conjunction with the actual elevation of the highest point of the foundation structure (such as track beams, cable trench covers, or supporting structures), and is usually slightly higher than this physical height to allow for a safety margin.

[0098] The preset angle threshold is a positive number in degrees, representing the maximum absolute value of the angle at which the slewing mechanism is allowed to approach the foundation structure. When the absolute value of the real-time slewing angle is less than or equal to this value, the system determines that the cantilever is within the small-angle danger sector. This preset angle threshold is calculated based on the horizontal distance from the slewing center of the bucket wheel excavator to the edge of the foundation structure and the cantilever length, ensuring that slewing within this angle range may cause structural interference.

[0099] The enable or disable command is implemented through the rotary interlocking enable / disable button or switch on the human-machine interface. The operator can manually select the enable or disable state, and the corresponding digital signal is generated and sent to the control processing unit.

[0100] When the instruction is disabled, the control processing unit does not execute the logic of the protection mode. That is, regardless of whether the real-time pitch height value and the real-time yaw angle value meet the trigger conditions, the control processing unit skips the direction restriction step, the pitch descent prohibition step, and the protection mode exit judgment, and fully opens the normal operating permissions of the yaw actuator and the hydraulic control system of the pitch mechanism.

[0101] This disabling mechanism is specifically designed for special operating conditions, such as when the material picking position needs to be finely adjusted at a small angle and low height at the end of the low material level picking process, or when the protection logic needs to be temporarily bypassed during the equipment debugging and calibration phase; however, the operational risk in the disabled state is borne by the operator, and the system no longer provides automatic anti-collision intervention.

[0102] Based on the aforementioned anti-collision protection system for the slewing mechanism of a bucket wheel excavator, this invention further proposes an anti-collision protection method for the slewing mechanism of a bucket wheel excavator, comprising the following steps: The raw signals of rotation angle and pitch height are obtained through the signal detection unit.

[0103] The original signal is processed by the control processing unit to obtain the real-time rotation angle value and the real-time pitch height value.

[0104] Thresholds are set through the human-computer interaction unit.

[0105] When the real-time pitch height value is less than or equal to the preset height threshold, and the absolute value of the real-time yaw angle value is less than or equal to the preset angle threshold, the protection mode is activated.

[0106] In protection mode, the control slewing actuator only allows the slewing mechanism to move away from the track foundation building.

[0107] Specifically, the process of processing the original signal includes: The original signal in Gray code format is converted into binary code by performing bitwise XOR logic operations. Then, data type conversions are performed sequentially, such as concatenating multiple bit data types into word data, converting word data types into integer data types, and converting integer data types into floating-point data types.

[0108] Finally, the real-time rotation angle value and real-time pitch height value are generated for comparison calculation.

[0109] like Figure 2 As shown in the figure, this is a schematic diagram of the electrical connection between the rotary absolute encoder and the pitch absolute encoder and the input module of the control processing unit. The figure shows that multiple signal lines (D0~Dn) of the encoder output port are respectively connected to the corresponding digital input points of the programmable logic controller (PLC) input card. All signal lines transmit parallel binary signals in Gray code format, used to send mechanical position information into the control system in Gray code form with strong anti-interference capabilities.

[0110] like Figure 3 As shown, this diagram is a functional block diagram or program flowchart of the Gray code decoding logic. The diagram illustrates the process by which the control processing unit calls the Gray code decoding function block to perform a bit-by-bit XOR operation on the input Gray code signal. Specifically, the highest-order binary code is equal to the highest-order bit of the Gray code, and the remaining binary codes are obtained by XORing their higher-order binary codes with the current Gray code. Finally, a complete binary code signal is output for subsequent data processing.

[0111] like Figure 4 As shown in the diagram, this illustrates the complete calculation chain for pitch height. The left side displays the binary signal after Gray code conversion, which sequentially passes through three data type conversion modules: "BIT concatenation to WORD," "WORD to INT," and "INT to REAL." The right side is the linear mapping calculation module, which receives the converted floating-point number and parameters such as the low-order bit value, high-order bit value, and altitude range set by the human-machine interface unit, and outputs the real-time pitch height value according to the formula. .

[0112] like Figure 5 As shown in the figure, this diagram illustrates the complete calculation chain for the rotation angle value. (Structure and appendix) Figure ThreeSimilarly: The input is a binary signal converted from a rotary absolute encoder to Gray code, which is then sequentially converted through BIT, WORD, INT, and REAL data types; subsequently, it enters the angle calculation module, which, combined with the left turn 90° code value and right turn 90° code value set by the human-machine interaction unit, outputs the real-time rotary angle value according to the formula. The left turn angle is negative, and the right turn angle is positive.

[0113] like Figure 6 As shown in the figure, this is a schematic diagram of the pitch control logic in protection mode. The figure includes a comparison and judgment module, which is used to detect whether the real-time pitch height value is less than or equal to a preset height threshold. When the protection mode is triggered, the logic output sends a prohibition signal to the hydraulic control system of the pitch mechanism, cutting off the enable condition for the descent operation, allowing only the ascent or hold action, thereby preventing further reduction of the cantilever height in the danger zone.

[0114] like Figure 7 As shown in the figure, this is a schematic diagram of the direction control logic of the slewing mechanism in protection mode. The figure includes the following functional modules: Real-time rotation angle value input terminal.

[0115] The preset angle threshold comparison module is used to determine whether the absolute value of the real-time rotation angle is less than or equal to the preset angle threshold.

[0116] The sign discrimination module is used to identify whether the real-time rotation angle value is positive or negative.

[0117] The direction command blocking logic unit, when the protection mode is activated and the small angle condition is met, if the real-time rotation angle value is positive, then the control command output for left rotation is blocked; if the real-time rotation angle value is negative, then the control command output for right rotation is blocked.

[0118] The direction command output terminal is connected to the control input terminal of the slewing actuator, and only outputs direction commands in the direction where the absolute value of the slewing angle increases, ensuring that the cantilever moves away from the foundation building of the travel track.

[0119] In a specific embodiment, the bucket wheel excavator has anti-collision protection under low material level and small angle operating conditions.

[0120] The rotary absolute encoder and pitch absolute encoder in the signal detection unit continuously output raw signals in Gray code format. These raw signals are then transmitted to the control processing unit.

[0121] The control processing unit calls the Gray code decoding function block to perform a bit-by-bit XOR logic operation on the original Gray code format signal, converting it into the corresponding binary code signal.

[0122] Subsequently, the control processing unit calls the data type conversion module to process the binary code signal after Gray code conversion: first, multiple bit type data are concatenated into word type data according to the encoder data bit order; second, the word type data is converted into integer type data; finally, the integer type data is converted into floating-point type data.

[0123] Based on the converted floating-point data and the parameters preset by the human-computer interaction unit, the control processing unit calculates the real-time pitch height and real-time rotation angle values.

[0124] Among them, real-time pitch height value Calculate using the following formula: The calculation yielded the result.

[0125] Real-time rotation angle value ( From the formula The calculation yielded the result.

[0126] The operator sets the preset height threshold to 6 meters and the preset angle threshold to 13° through the human-machine interface unit, and sets the protection mode enable command to the enabled state.

[0127] The control processing unit continuously compares the real-time pitch height value with a preset height threshold and the absolute value of the real-time yaw angle value with a preset angle threshold. When the real-time pitch height value is less than or equal to 6 meters and the absolute value of the real-time yaw angle value is less than or equal to 13°, the control processing unit triggers the protection mode.

[0128] In protected mode, the control processing unit performs the direction restriction step: If the real-time rotation angle value is positive and its value is less than or equal to 13°, then the control command for left rotation is blocked. If the real-time rotation angle value is negative and its absolute value is less than or equal to 13°, then the control command for right rotation is blocked.

[0129] The control processing unit outputs the permitted direction control commands to the control output terminal of the slewing actuator. The slewing actuator, based on the received commands, drives the slewing mechanism to move only in the direction away from the foundation structure of the travel track.

[0130] At the same time, the control processing unit outputs a control signal to the hydraulic control system of the pitch mechanism to prohibit it from performing the descent operation.

[0131] Before outputting any slewing control command, the control processing unit performs a slewing condition determination step to verify whether the following conditions are met: both the slewing power switch and the brake fan power switch are in the closed state, the slewing inverter has no fault signal, and the slewing motor is not overloaded or the operating mode selection switch is in adjustment. Only when all of the above conditions are met is the output of the slewing control command permitted.

[0132] In protection mode, the control processing unit continuously monitors the real-time pitch height and real-time yaw angle values. When the real-time pitch height value is greater than 6 meters, or the absolute value of the real-time yaw angle value is greater than 13°, the control processing unit automatically exits the protection mode, removing the restriction on the yaw direction and the prohibition on pitch descent.

[0133] If the operator outputs a command to disable the protection mode through the human-machine interface unit, the control processing unit will not execute the protection mode triggering, direction restriction, pitch descent prohibition and exit logic, and the slewing execution unit and the hydraulic control system of the pitch mechanism will operate according to the normal logic.

[0134] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A collision protection system for the slewing mechanism of a bucket wheel excavator, characterized in that, include: The signal detection unit includes a rotary absolute encoder and a pitch absolute encoder; The control processing unit is signal-connected to the signal detection unit; The human-computer interaction unit is communicatively connected to the control processing unit. A rotary execution unit is connected to the control output terminal of the control processing unit; The control processing unit is configured as follows: Based on the real-time signal from the signal detection unit, the real-time pitch height and real-time yaw angle values ​​are calculated. When the real-time pitch height value is less than or equal to a preset height threshold, and the absolute value of the real-time yaw angle value is less than or equal to a preset angle threshold, the protection mode is triggered. In protection mode, the rotary actuator is controlled so that the rotary mechanism can only run in a direction away from the foundation building of the travel track; The human-computer interaction unit is used to set the preset height threshold and the preset angle threshold, and to output instructions to enable or disable the protection mode. When the instruction is disabled, the control processing unit does not execute the logic of the protection mode.

2. The anti-collision protection system for the slewing mechanism of a bucket wheel excavator according to claim 1, characterized in that, The process by which the control processing unit calculates the real-time value based on the real-time signal from the signal detection unit includes a Gray code conversion step: The control processing unit calls the Gray code decoding function block to convert the Gray code signals output by the rotary absolute encoder and the pitch absolute encoder respectively; The conversion is achieved through bitwise XOR logic operations, which convert the Gray code signal into the corresponding binary code signal.

3. The anti-collision protection system for the slewing mechanism of a bucket wheel excavator according to claim 2, characterized in that, The calculation process also includes a data type conversion step: The control processing unit calls the data type conversion module to process the binary code signal after Gray code conversion. The data processing includes, in sequence: concatenating multiple bit-type data into word-type data, converting the word-type data into integer-type data, and converting the integer-type data into floating-point-type data, ultimately generating the real-time pitch height value and real-time yaw angle value for comparison and calculation.

4. The anti-collision protection system for the slewing mechanism of a bucket wheel excavator according to claim 1, characterized in that, The specific logic by which the control processing unit controls the rotary execution unit in protected mode includes a direction limiting step: If the real-time rotation angle value is positive and its value is less than or equal to the preset angle threshold, then the control command for left rotation is blocked. If the real-time rotation angle value is negative and its absolute value is less than or equal to the preset angle threshold, then the control command for right rotation is blocked.

5. The anti-collision protection system for the slewing mechanism of a bucket wheel excavator according to claim 1, characterized in that, The control processing unit is also configured to perform the protection mode exit procedure: In protection mode, the real-time pitch height value and real-time yaw angle value are continuously monitored; When the real-time pitch height value is detected to be greater than the preset height threshold, or the absolute value of the real-time yaw angle value is greater than the preset angle threshold, the protection mode is automatically exited.

6. The anti-collision protection system for the slewing mechanism of a bucket wheel excavator according to claim 1, characterized in that, It also includes a pitch mechanism hydraulic control system connected to the control processing unit; The control processing unit is further configured to output a control signal to prohibit the pitch mechanism hydraulic control system from performing a descent operation when the protection mode is triggered.

7. The anti-collision protection system for the slewing mechanism of a bucket wheel excavator according to claim 1, characterized in that, Before outputting control commands to the rotary execution unit, the control processing unit performs a rotary condition determination step to verify whether the rotary conditions are met. The slewing conditions include: both the slewing power switch and the brake fan power switch are in the closed state, and there is no fault signal from the slewing inverter; and the slewing motor is not overloaded or the operation mode selection switch is in adjustment.

8. The anti-collision protection system for the slewing mechanism of a bucket wheel excavator according to claim 1, characterized in that, The rotary actuator includes a frequency converter, a rotary motor, and a mechanical brake that are sequentially electrically connected. The output port of the control processing unit is connected to the start / stop control terminal and direction control terminal of the frequency converter through a control loop to output direction control commands.

9. A method for preventing collisions in the slewing mechanism of a bucket wheel excavator, characterized in that, include: The raw signals of rotation angle and pitch height are obtained through the signal detection unit; The original signal is processed by the control processing unit to obtain the real-time rotation angle value and the real-time pitch height value. The preset height threshold and preset angle threshold can be set through the human-computer interaction unit; When the real-time pitch height value is less than or equal to the preset height threshold, and the absolute value of the real-time yaw angle value is less than or equal to the preset angle threshold, the protection mode is activated. In protection mode, the control slewing actuator only allows the slewing mechanism to move away from the track foundation building.

10. A method for preventing collisions in the slewing mechanism of a bucket wheel excavator according to claim 9, characterized in that, The process of processing the original signal includes: The original signal in Gray code format is converted into binary code by performing bitwise XOR logic operations. Then, multiple bit data types are concatenated into word data, word data is converted into integer data, and integer data is converted into floating-point data.

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