A cable winding control method for an electric shovel

Abstract

The present application relates to the technical field of electrical control of mine machinery, and discloses a cable winding control method for an electric shovel, which comprises a first-stage state decision: collecting vehicle gear signals and cable guide arm position signals in real time, and following preset state transition logic; and a second-stage parameter adaptive control: after determining a working state, according to the working state, real-time vehicle speed, and cable remaining turns calculated from a rotary encoder signal, querying a preset parameter mapping table or calling a dynamic calculation model, real-time calculation and output of accurate control parameters for driving an execution mechanism. The cable winding control method for the electric shovel combines vehicle gears (driving intention) and guide arm positions (real-time geometric state of the cable) to make joint logic judgment, realizes active prediction and decision of the movement trend of the equipment and the stress risk of the cable, avoids the hysteresis problem of single tension feedback from the source, and makes the cable winding and unwinding action highly synchronized with the actual movement path intention of the vehicle.

Description

Technical Field

[0001] This invention relates to the field of electrical control technology for mining machinery, and in particular to a cable reel control method for an electric loader. Background Technology

[0002] Electric underground loaders are powered by cables wound up and down on a reel and need to move and turn frequently within tunnels. The reliability of cable management directly affects the equipment's continuous operation capability and safety. Current common cable reel control technologies have the following main shortcomings: 1) Simple and crude control method with delayed response: Most systems rely solely on feedback control by detecting cable tension (such as through tension sensors or torque motors). This passive response mode is lagging and cannot adapt to sudden tension changes when the vehicle starts, stops, or turns quickly. This can easily lead to the cable becoming loose and dragging on the ground or being suddenly tightened and impacted, causing the cable to be crushed, broken, or the joint to be damaged.

[0003] 2) Lack of motion trend prediction: Traditional methods do not fully consider the vehicle's own operating intentions (such as gear signals) and real-time attitude (relative to the direction of the cable). For example, if the cable is already under lateral tension (while turning) when the vehicle is moving forward, releasing the cable at this time may cause excessive friction between the cable and the roadway wall or cable accumulation. Existing systems cannot intelligently identify and make decisions for this complex working condition.

[0004] 3) Fixed control parameters and poor adaptability: The driving force for cable winding and unwinding (such as hydraulic system pressure or motor torque) is often a fixed value or only a simple adjustment. It is impossible to make dynamic and precise coordinated adjustments based on multiple variables such as the number of cable turns remaining on the drum (equivalent drum diameter), real-time vehicle speed, and equipment status. This results in insufficient tension and easy loosening at the end of cable winding (when the drum diameter is small), or excessive tension hindering movement at the beginning of cable unwinding.

[0005] 4) Weak fault response capability: When critical sensors (such as position sensors that detect cable deflection) fail, the system can usually only alarm and shut down, lacking a safety redundancy strategy for degraded operation, which affects the continuity of operation. Summary of the Invention

[0006] In view of the problems of existing control methods being simple and crude, having slow response, lacking prediction of motion trends, and having fixed control parameters, poor adaptability and weak fault response capabilities, this invention is proposed.

[0007] Therefore, the purpose of this invention is to provide a cable reel control method for an electric shovel loader, which aims to achieve active predictive control based on state transition and adaptive fine adjustment based on multi-parameter coupling.

[0008] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a cable reel control method for an electric loader, comprising the following steps: Level 1 State Decision: Real-time acquisition of vehicle gear position signal and cable guide arm position signal, and determination of which of the three working states the system should enter at present, namely "cable take-up", "cable release" or "static hold", according to the preset state transition logic; Second-level parameter adaptive control: After determining the working state, based on the working state, real-time vehicle speed, and the number of remaining cable turns calculated from the rotary encoder signal, the system calculates and outputs precise control parameters for driving the actuator in real time by querying a preset parameter mapping table or calling a dynamic calculation model.

[0009] In a preferred embodiment of the cable reel control method for the electric shovel loader described in this invention, the state transition logic specifically comprises: When the gear is forward and the guide arm is in the middle area, the decision is to release the cable. When the gear is forward and the guide arm is at its left or right limit, the decision is to retract the cable. When the gear is reverse and the guide arm is in the middle area, the decision is to retract the cable. When the gear is reverse and the guide arm is at its left or right limit, the decision is to release the cable. When the gear is in neutral or the vehicle is stopped, the decision is to remain in a static state.

[0010] As a preferred embodiment of the cable reel control method for the electric shovel loader described in this invention, in the cable unloading state, the control parameters are calculated by using the remaining number of cable turns as the basic compensation amount, superimposing the fine-tuning amount made according to the current gear position, to generate the cable unloading control amount.

[0011] As a preferred embodiment of the cable reeling control method for the electric shovel loader described in this invention, in the cable reeling state, the control parameters are calculated as follows: the remaining number of cable turns is used as a lookup table compensation amount to offset the influence of changes in the cable diameter, and the real-time vehicle speed is superimposed as the main correction variable for lookup table compensation. The higher the vehicle speed, the greater the control amount is, so as to provide a greater cable reeling force to counteract the cable inertia.

[0012] As a preferred embodiment of the cable reel control method for the electric shovel loader described in this invention, in the static holding state: when the guide arm deviates from the middle position due to external force, the system restores the control quantity with a slowly increasing variable that increases gradually with the square of time, thereby achieving a smooth tensioning from zero tension to the target tension without impact.

[0013] As a preferred embodiment of the cable reel control method for the electric loader described in this invention, the method further includes a fail-safe sub-mode: when a fault is detected in the guide arm position signal, the system switches to a preset constant safety control value to maintain basic cable force to ensure minimum safe operation, and at the same time issues a fault alarm.

[0014] In a preferred embodiment of the cable reel control method for the electric loader described in this invention, the actuator is a proportional control valve and a hydraulic motor driven by the valve. The proportional control valve is used to control the forward and reverse rotation and speed of the hydraulic motor. The precise control parameter is the current or voltage signal of the proportional control valve.

[0015] In a preferred embodiment of the cable reel control method for the electric shovel loader described in this invention, the actuator is a frequency converter and a cable reel motor driven by it, and the precise control parameter is the frequency setpoint signal of the frequency converter.

[0016] As a preferred embodiment of the present invention, a cable reel control system for an electric loader is characterized by comprising: The signal acquisition module is used to acquire vehicle gear position signal, driving speed signal, cable guide arm position signal and cable drum rotary encoder signal in real time; The central control unit is electrically connected to the signal acquisition module and has a pre-set state decision logic and dynamic parameter control model for executing the steps of the method according to any one of claims 1-8; The execution module, controlled by the control signal output by the central control unit, is used to drive the cable reel to rotate in both directions.

[0017] As a preferred embodiment of the present invention, the central control unit includes: The first-level state decision module is used to determine the current working state to be entered based on the vehicle gear position signal and the cable guide arm position signal; The secondary parameter adaptive control module is used to calculate and output the precise control parameters in real time based on the working status, real-time vehicle speed, and the number of remaining cable turns. The fault diagnosis and fault tolerance module is used to detect faults in the guide arm position sensor and switch to safety control mode when a fault occurs.

[0018] Compared with the prior art, the present invention has at least the following beneficial effects: 1. This invention combines vehicle gear position (driving intention) with guide arm position (real-time geometric state of cable) for joint logic judgment, thereby enabling proactive prediction and decision-making on equipment movement trends and cable stress risks. This avoids the lag problem of single tension feedback from the source, and makes the cable winding and unwinding actions highly synchronized with the actual movement path intention of the vehicle.

[0019] 2. This invention proposes a layered, multi-mode dynamic calculation model for control parameters. In cable retrieval mode, real-time vehicle speed is used as the core correction factor for the control quantity, achieving dynamic compensation of the retrieval force for motion inertia, fundamentally solving the industry problem of cables easily slack and drag on the ground during high-speed movement; in cable release mode, "turn compensation + gear fine-tuning" is adopted to achieve adaptive matching of cable release resistance; in static mode, a "gradual square" recovery algorithm is used to achieve extremely smooth, impact-free tensioning, protecting equipment and cables.

[0020] 3. This invention designs a dedicated fail-safe sub-mode. When a sensor fails, the system does not immediately shut down, but instead switches to a conservative control mode with fixed safety parameters. This allows the equipment to be temporarily moved to a safe position under restricted conditions, thereby enhancing the robustness and operational continuity of the system.

[0021] 4. This invention provides a complete and systematic control scheme that integrates state perception, intelligent decision-making, mode division, and parameter adaptation. All aspects work together to achieve the ultimate goal of constant cable tension management, significantly improving the intelligence level and overall reliability of electric loaders. Attached Figure Description

[0022] Figure 1 This is a flowchart illustrating the cable reel control method for the electric shovel loader of the present invention. Detailed Implementation

[0023] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0024] System Overall Architecture The electric shovel loader cable reel control system provided by the present invention mainly includes: a signal acquisition module, a central control unit, and an execution module.

[0025] The signal acquisition module includes: a gear position sensor for acquiring the vehicle's forward / reverse / neutral gear signals; a vehicle speed sensor (such as a gearbox output shaft speed sensor or radar speed sensor) for acquiring real-time driving speed; a guide arm position sensor (such as an angle sensor or proximity switch) for detecting the deflection position (left limit, middle, right limit) of the cable guide arm relative to the vehicle body; and a rotary encoder, installed at the cable reel shaft, for detecting the number of rotations and direction of the reel, thereby calculating the remaining number of cable turns.

[0026] The central control unit adopts a programmable logic controller (PLC) or an embedded microcontroller (MCU), which has pre-built state decision logic and dynamic parameter control model to execute the two-level control process of the present invention.

[0027] The execution module includes a proportional control valve (such as a proportional solenoid valve) and a hydraulic motor driven by it. The proportional control valve is controlled by the current or voltage signal output by the central control unit. By adjusting the hydraulic oil flow, it controls the forward and reverse rotation and speed of the hydraulic motor, thereby driving the cable reel to perform cable winding or unwinding actions.

[0028] Example 1: System Initialization and State Decision After the vehicle is powered on and started, the central control unit first performs a system self-test to check whether the signals from each sensor are normal and whether communication is smooth. After the self-test passes, the system enters standby mode, waiting for vehicle operation commands.

[0029] The system reads sensor data in real time at a sampling frequency of no less than 50Hz: gear position signal (forward / reverse / neutral), guide arm position signal (left limit / middle / right limit), vehicle speed signal (0~10V corresponds to 0~20km / h), and rotary encoder pulse count (calculates drum speed and direction by the number of pulses per unit time).

[0030] The central control unit inputs the above signals into the first-level state decision module, which then makes a judgment according to the preset state transition logic: Cable release status determination: When the gear is "forward" (vehicle driving forward away from the power supply point) and the guide arm is in the "middle" area, the system decides to release the cable. Cable retraction status determination: When the gear is "forward" and the guide arm is at the "left limit" or "right limit", it is determined that although the vehicle is moving forward, the cable has been tucked laterally (possibly during turning or attitude adjustment), and the system decides to be in the "cable retraction" state. Cable retraction status determination: When the gear is "reverse" (vehicle is approaching the power supply point in the forward direction) and the guide arm is in the "middle" area, the system decides to "retract cable" status; Cable release status determination: When the gear is "reverse" and the guide arm is at the "left limit" or "right limit", the system decides to release the cable. Static hold determination: When the gear is in "neutral" or the vehicle speed is zero, the system decides to enter the "static hold" state.

[0031] This state transition logic enables proactive prediction of equipment movement trends and cable stress risks, thus avoiding the lag problem of single tension feedback from the source.

[0032] Example 2: Adaptive Parameter Control in Cable Laying Mode When the primary state decision determines the "cable release" state, the system enters the cable release mode and executes secondary parameter adaptive control. The control quantity is calculated using a "revolving compensation + gear fine-tuning" strategy.

[0033] The central control unit first calculates the remaining number of cable turns based on the cumulative pulse count of the rotary encoder. The specific calculation method is as follows: when the encoder is unloaded (the cable is fully unloaded), it records the initial pulse count. The difference between the current pulse count and the initial pulse count is divided by the number of pulses corresponding to each turn of the drum to obtain the current number of cable turns on the drum.

[0034] In cable release mode, the system generates a basic braking force control value based on the number of remaining turns of the cable: when there are many remaining turns, the basic braking force is set to a smaller value to allow the cable to be released smoothly; when there are few remaining turns, the basic braking force is set to a larger value to prevent the cable from being released too much due to inertia at the end of the drum, which could cause it to become tangled.

[0035] The basic braking force control quantity is further superimposed with a gear fine-tuning quantity: when the current gear is forward, the fine-tuning quantity is positive (to increase cable release resistance and prevent the cable from being released too quickly due to vehicle acceleration); when the current gear is neutral or reverse, the fine-tuning quantity is zero or negative. The final output current or voltage signal to the proportional control valve is the value of the sum of the basic braking force control quantity and the gear fine-tuning quantity. This signal is output to the proportional control valve through a pulse width modulation or digital-to-analog converter module to control the output torque of the hydraulic motor, achieving adaptive matching to the cable release resistance.

[0036] Example 3: Adaptive Parameter Control in Cable Retrieval Mode When the primary state decision determines the "reel-in" state, the system enters the reel-in mode. The calculation of the control quantity adopts a "lap count compensation + vehicle speed correction" strategy.

[0037] In cable winding mode, real-time vehicle speed serves as the core correction factor for the control input. The central control unit calculates the real-time vehicle speed based on the vehicle speed sensor signal. The basic component of the control input is compensated using a lookup table based on the remaining cable turns to offset the impact of changes in cable diameter: when there are many remaining turns (larger cable diameter), the winding torque requirement is high, and the basic control input takes a large value; when there are few remaining turns (smaller cable diameter), the winding torque requirement is low, and the basic control input takes a small value.

[0038] The control quantity correction is a dynamic compensation based on vehicle speed: the higher the vehicle speed, the greater the control quantity, to provide a greater cable retrieval force to counteract cable inertia and ensure the cable remains taut during high-speed movement. As the vehicle speed decreases, the cable retrieval force decreases synchronously to avoid excessive cable pulling. This speed compensation proportional coefficient is pre-calibrated according to the vehicle model and cable specifications and stored in the parameter mapping table of the central control unit.

[0039] Example 4: Shock-free tension control in static holding mode When the first-level state decision determines the "static hold" state, the system enters the static hold mode. In this mode, when the guide arm deviates from the center position due to external force (such as slight pulling of the cable), the system restores the cable tension in an extremely smooth manner.

[0040] Specifically, the central control unit monitors the deviation of the guide arm from its center position in real time. When the deviation exceeds the preset dead zone range, the system initiates the tension recovery procedure. The rate of change of the recovery control quantity gradually increases with the square of time, causing the control quantity to slowly increase from zero and accelerate towards the target value over time. This achieves a smooth, shock-free tensioning process from zero tension to the target tension, effectively avoiding damage to the cable joint and drum drive mechanism from mechanical impact. When the guide arm returns to the dead zone range of the center position, the control quantity maintains its current value, and the system enters a static holding state.

[0041] Example 5: Fail-Safe Submode When the central control unit detects an abnormality in the guide arm position sensor signal (such as the signal being outside the normal range, the signal fluctuating drastically, or the sensor being disconnected), the system automatically switches to fail-safe sub-mode.

[0042] In fail-safe sub-mode, the system no longer relies on the guide arm position signal for state decision-making. Instead, it controls the execution module according to preset constant safety parameters. Specifically, the system outputs a medium-low safety control quantity to maintain basic cable tension and ensure that the cable does not loosen or drag on the ground under minimum safety conditions.

[0043] Meanwhile, the system issues a continuous fault alarm through the audible and visual alarm device in the cab to remind the operator of sensor malfunctions; the system allows the equipment to be moved to a safe location at a low speed and short distance for maintenance under restricted conditions without immediate shutdown, which enhances the robustness and continuity of operation of the system; when the sensor signal returns to normal, the system automatically exits the fail-safe sub-mode and resumes the normal secondary control process.

[0044] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A cable reel control method for an electric loader, characterized in that, Includes the following steps: Level 1 State Decision: Real-time acquisition of vehicle gear position signal and cable guide arm position signal, and determination of which of the three working states the system should enter: "cable winding", "cable unwinding" or "static holding" according to the preset state transition logic; Second-level parameter adaptive control: After determining the working state, based on the working state, real-time vehicle speed, and the number of remaining cable turns calculated from the rotary encoder signal, the system calculates and outputs precise control parameters for driving the actuator in real time by querying a preset parameter mapping table or calling a dynamic calculation model.

2. The cable reel control method for an electric loader according to claim 1, characterized in that: The state transition logic is specifically as follows: When the gear is forward and the guide arm is in the middle area, the decision is to release the cable. When the gear is forward and the guide arm is at its left or right limit, the decision is to retract the cable. When the gear is reverse and the guide arm is in the middle area, the decision is to retract the cable. When the gear is reverse and the guide arm is at its left or right limit, the decision is to release the cable. When the gear is in neutral or the vehicle is stopped, the decision is to remain in a static state.

3. The cable reel control method for an electric loader according to claim 2, characterized in that: In the cable laying state, the control parameters are calculated as follows: the remaining number of cable turns is used as the basic compensation amount, and the fine-tuning amount made according to the current gear position is added to generate the cable laying control amount.

4. The cable reel control method for an electric loader according to claim 3, characterized in that: In the cable winding state, the control parameters are calculated as follows: the remaining number of cable turns is used as a lookup table compensation amount to offset the influence of the change in cable diameter, and the real-time vehicle speed is superimposed as the main correction variable for lookup table compensation. The higher the vehicle speed, the greater the control amount is, so as to provide a greater winding force to counteract the cable inertia.

5. The cable reel control method for an electric loader according to claim 4, characterized in that: In the static holding state: when the guide arm deviates from the middle position due to external force, the system restores the control quantity with a slowly increasing variable that increases gradually with the square of time, so as to achieve smooth tensioning from zero tension to the target tension without impact.

6. The cable reel control method for an electric loader according to claim 1, characterized in that: The system also includes a fail-safe sub-mode: when a fault is detected in the guide arm position signal, the system switches to a preset constant safety control value to maintain basic cable force to ensure minimum safe operation, and at the same time issues a fault alarm.

7. The cable reel control method for an electric loader according to any one of claims 1-6, characterized in that, The actuator is a proportional control valve and a hydraulic motor driven by it. The proportional control valve is used to control the forward and reverse rotation and speed of the hydraulic motor. The precise control parameter is the current or voltage signal of the proportional control valve.

8. The cable reel control method for an electric loader according to any one of claims 1-6, characterized in that, The actuator is a frequency converter and a cable reel motor driven by it, and the precise control parameter is the frequency setpoint signal of the frequency converter.

9. A cable reel control system for an electric loader, characterized in that, include: The signal acquisition module is used to acquire vehicle gear position signal, driving speed signal, cable guide arm position signal and cable drum rotary encoder signal in real time; The central control unit is electrically connected to the signal acquisition module and has a pre-set state decision logic and dynamic parameter control model for executing the steps of the method according to any one of claims 1-8; The execution module, controlled by the control signal output by the central control unit, is used to drive the cable reel to rotate in both directions.

10. The system according to claim 9, characterized in that, The central control unit includes: The first-level state decision module is used to determine the current working state to be entered based on the vehicle gear position signal and the cable guide arm position signal; The secondary parameter adaptive control module is used to calculate and output the precise control parameters in real time based on the working status, real-time vehicle speed, and the number of remaining cable turns. The fault diagnosis and fault tolerance module is used to detect faults in the guide arm position sensor and switch to safety control mode when a fault occurs.

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