An electric loader material shovel wheel edge slip control method and system

Abstract

This invention belongs to the field of engineering machinery control technology, specifically a method and system for controlling wheel-side slippage during material loading in an electric loader. The method acquires the accelerator pedal status, overall vehicle direction status, and bucket status of the electric loader. When the bucket matching control conditions are met, the system determines whether slippage tendency exists based on the travel motor speed and torque status, combined with the overall vehicle speed. If slippage tendency exists, the system synchronously executes control based on the current bucket load status: controlling the bucket to rotate a preset angle towards the full bucket angle by a preset unit time, while simultaneously controlling the travel motor to reduce torque by a preset step size until the bucket rotates to the preset full bucket angle and stops. This invention, through the coordinated control of the bucket and travel motor, proactively intervenes before slippage occurs, effectively reducing wheel-side slippage, improving loading efficiency, reducing tire wear and energy consumption, and extending equipment endurance.

Description

Technical Field

[0001] This invention belongs to the field of engineering machinery control technology, specifically a method and system for controlling the slippage of the material loading wheel of an electric loader. Background Technology

[0002] The statements in this section merely refer to the background art related to this invention and do not necessarily constitute prior art.

[0003] Electric loaders are widely used in material handling and bulk loading operations due to their advantages such as fast power response, high energy efficiency, and good comfort. Their walking system uses a battery-powered motor to drive the vehicle's forward and reverse movements, while the working device uses an independent motor to drive a hydraulic system to move the bucket. However, in actual loading operations, operators typically rely on experience to control the accelerator pedal and bucket posture, making it difficult to achieve precise matching under complex and changing material conditions.

[0004] Because the motor output response speed of electric loaders is significantly faster than that of traditional fuel-powered equipment, wheel slippage can easily occur if the travel motor torque and bucket angle are not properly controlled when the bucket cuts into material. Wheel slippage not only accelerates tire wear and shortens tire life, but also reduces work efficiency, increases energy consumption, shortens equipment endurance, and can even affect task completion if the wheels get stuck in the ground. Current technology mainly relies on the operator's long-term experience to avoid slippage, lacking systematic active control methods and making it difficult to adapt to the power matching requirements under different load conditions. Summary of the Invention

[0005] This invention provides a method and system for controlling wheel slippage during material loading in an electric loader. It proactively identifies the "imminent slippage" trend during the loading process, rather than correcting it after slippage occurs, without relying on operator experience. By coordinating the bucket movement with the travel motor torque, it simultaneously adjusts the bucket entry angle and driving force at critical points, and dynamically matches control parameters according to light, medium, and heavy loads, thereby preventing slippage at its source and balancing bucket fullness and energy efficiency.

[0006] The first aspect of this invention discloses a method for controlling the slippage of the material loading wheel of an electric loader, comprising the following steps: Obtain the current accelerator pedal status, overall vehicle direction status, and bucket status of the electric loader; When the bucket matching control conditions are met, the system determines whether there is a slippage trend based on the travel motor speed and torque status, combined with the vehicle speed. The bucket matching control conditions include the bucket being in a horizontal position, the vehicle being in a forward direction, the accelerator pedal being in an acceleration or maintaining an acceleration trend, and the current bucket load status being detected. When a slippage tendency exists, the following control strategy is executed synchronously based on the current bucket load status: The bucket rotates at a preset angle towards the full bucket position within a preset unit of time. The walking motor reduces torque by a preset step size; The bucket stops rotating after reaching the preset full-bucket angle.

[0007] Furthermore, the load condition of the bucket is divided into three ranges: light load, medium load, and heavy load, based on the bucket's rated load capacity.

[0008] Furthermore, depending on the load conditions, the bucket rotates at different angles within a preset unit of time; among them, the bucket rotates fastest in light load mode, slowest in heavy load mode, and between light load mode and heavy load mode in medium load mode.

[0009] Furthermore, the preset step size for reducing the torque of the walking motor varies depending on the load condition; in light load mode, the motor torque step size is the smallest and accompanied by a delay, in medium load mode the motor torque step size is the standard step size, and in heavy load mode the motor torque step size is the largest and has no delay.

[0010] Furthermore, determining the slip trend includes: The measured speed of the walking motor is converted into the theoretical wheel speed through the transmission ratio and compared with the wheel speed measured by the wheel speed sensor. When the theoretical wheel speed exceeds the set percentage of the measured wheel speed, it is determined that there is a slippage trend of the wheel. When there is a tendency for wheel slippage, if the vehicle speed continues to decrease, the torque of the drive motor continues to increase, and the vehicle speed approaches zero, it is determined that wheel slippage is about to occur.

[0011] Furthermore, the full bucket angle is the angle between the bucket opening plane and the horizontal plane when the bucket is in its normal load-bearing posture after being loaded with material. This angle is pre-stored in the storage unit of the vehicle controller.

[0012] Furthermore, when the bucket matching control conditions are not met, the vehicle controller continuously monitors the accelerator pedal status, direction status, and bucket status, and does not activate the slip control.

[0013] Furthermore, when there is no slippage trend, the vehicle controller accumulates the current state over time and compares it with the preset stall alarm threshold. When the accumulated time exceeds the threshold, a motor stall over-temperature alarm is issued.

[0014] Furthermore, the bucket rotation action is executed by a bucket rotation action solenoid valve, which uses PWM proportional control; the torque control of the travel motor is executed by the travel motor controller.

[0015] A second aspect of the present invention discloses a material loading wheel-side slip control system for an electric loader, comprising: Vehicle controller; The pedal status detection device is electrically connected to the vehicle controller and is used to collect the status of the accelerator pedal; The reversing input device is electrically connected to the vehicle controller and is used to collect the vehicle's directional status. The bucket status detection device is electrically connected to the vehicle controller and is used to collect bucket status data. The motor speed and torque detection device is electrically connected to the vehicle controller and is used to collect the speed and torque status of the walking motor. The bucket rotation solenoid valve is electrically connected to the output of the vehicle controller and is used to control the bucket rotation. The vehicle controller is configured to: when the bucket matching control conditions are met, determine whether there is a slippage trend based on the travel motor speed and torque status and the overall vehicle speed; the bucket matching control conditions include the bucket being in a horizontal position, the overall vehicle direction being forward, the accelerator pedal being in acceleration or maintaining an acceleration trend, and the current bucket load status being detected. When there is a tendency to slip, the vehicle controller synchronously executes the following control according to the current bucket load status: the bucket is controlled to rotate at a preset angle in the direction of full bucket angle by the bucket rotation action solenoid valve, and at the same time the travel motor is controlled to reduce torque by a preset step size until the bucket rotates to the preset full bucket angle and then stops.

[0016] Compared with existing technologies, one or more of the above technical solutions have the following beneficial effects: By uniformly acquiring accelerator pedal position, vehicle direction, bucket posture, and motor status through the vehicle controller, and under loading conditions where the bucket is level, the forward direction is forward, the acceleration trend is known, and the load is known, the system actively identifies the precursory characteristics of slippage: "vehicle speed decreases, torque increases, and vehicle speed approaches zero." Before slippage occurs, it simultaneously executes coordinated control of bucket upward rotation drag reduction and motor torque reduction. This advances the slippage suppression timing from "passive correction after it has occurred" to "active intervention before it is about to occur," balancing the relationship between driving force and driving resistance from the source. Compared to existing control methods that rely on operator experience and where the bucket and drive are independent, this invention automatically suppresses slippage without operator prediction. While ensuring full bucket capacity, it significantly reduces tire wear, lowers operating energy consumption, extends equipment endurance, and reduces operator fatigue, exhibiting excellent power performance, economy, and operational adaptability. Attached Figure Description

[0017] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0018] Figure 1A schematic diagram of the material loading wheel-side sliding control system architecture of an electric loader provided in one or more embodiments of the present invention; Figure 2 A schematic diagram illustrating the working process of the material loading wheel-side slip control system of an electric loader provided in one or more embodiments of the present invention; Figure 3 A schematic flowchart of a material loading wheel-side slip control method for an electric loader provided in one or more embodiments of the present invention. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0021] Terminology Explanation: Electric loader: A device that relies on a power battery to drive a travel motor for movement, and uses a drive motor as a power source to power the hydraulic motors of the working device and the steering hydraulic motor. This equipment has a simple structure and features high work efficiency, good comfort, and low operating and maintenance costs.

[0022] Because the travel motor of an electric loader is directly driven by a power battery, the motor output torque can respond to accelerator pedal commands within milliseconds, without experiencing delays such as engine speed increase and torque converter coupling. This characteristic gives electric loaders advantages such as large starting thrust and fast dynamic response in loading operations, but at the same time, it significantly reduces the operator's window of opportunity to perceive and correct changes in driving force.

[0023] During the material loading process, the bucket cutting into the material pile generates gradually increasing travel resistance. When the wheel-side driving force corresponding to the output torque of the travel motor exceeds the adhesion limit between the tires and the ground, the wheel-side begins to slip. Whether slippage occurs depends on the instantaneous balance of several key factors: motor output torque, bucket cutting resistance, and ground adhesion coefficient.

[0024] The typical operating conditions for an electric loader in the initial loading stage are as follows: the vehicle speed decreases from forward to zero, the motor torque continuously increases, and the bucket is in a horizontal cutting position. If the accelerator pedal is pressed further at this point, the motor torque rapidly increases, while the vehicle speed is already close to zero. The margin between the wheel-side driving force and the ground adhesion quickly disappears, and slippage occurs. Traditional operation relies on the operator to "anticipate" slippage by releasing the pedal or adjusting the bucket before feeling it. However, for electric loaders, this time window is extremely short, making operation significantly more difficult than with fuel-powered equipment.

[0025] Most existing electric loaders use torque control for their travel motors, meaning the accelerator pedal opening directly corresponds to the target motor torque. While this mode offers good linear response under stable driving conditions, it lacks closed-loop monitoring of wheel-side adhesion in demanding scenarios like shoveling, which involve high resistance, low speed, and variable loads. The bucket movement and travel drive are independent of each other, making it impossible to proactively adjust their matching before slippage occurs. This results in a passive correction after slippage, achieved only by reducing motor torque, by which time tire wear has already occurred, and operational continuity has been interrupted.

[0026] It is evident that slip control in electric loader loading operations is essentially a multivariate, strongly coupled, short-time-window dynamic matching problem. It requires simultaneously handling multiple variables, including acceleration intent, bucket posture and load, travel motor status, and wheel-side adhesion tendency. Therefore, this solution provides a method and system for controlling wheel-side slip in electric loader material loading. It proactively identifies the "imminent slip" tendency during the loading process, rather than correcting it after slippage occurs, without relying on operator experience. By coordinating the control of bucket movement and travel motor torque, it simultaneously adjusts the bucket entry angle and driving force at critical points, and dynamically matches control parameters according to light, medium, and heavy loads, thereby preventing slippage at its source and balancing bucket fullness and energy efficiency.

[0027] Example 1: The architecture of a material loading wheel-side slip control system for an electric loader is as follows: Figure 1 As shown, it includes a vehicle controller 1, a pedal status detection device 2, a reversing input device 3, a bucket status detection device 4, a motor speed and torque detection device 5, a bucket rotation solenoid valve 6, and an intelligent instrument prompting device 7.

[0028] The pedal status detection device, reversing input device, bucket status detection device, and motor speed and torque detection device are all connected to the input ports of the vehicle controller to collect vehicle status and operational intent information in real time. The bucket rotation solenoid valve is connected to the output port of the vehicle controller to output a PWM proportional control signal based on the calculation results of the vehicle controller, driving the bucket to rotate in set steps. The intelligent instrument display device is connected to the vehicle controller via a communication bus to display system status, alarm information, and allow operators to set control parameters.

[0029] The pedal state detection device is used to collect the current state changes of the accelerator pedal and determine the driver's driving intention. The accelerator pedal state is obtained through an angle sensor installed on the pedal. The driver's driving intention is determined based on the rotation angle of the angle sensor. The value of the pedal rotation angle per unit time can represent the driver's acceleration characteristics, including driving intentions such as rapid acceleration, gradual acceleration, speed maintenance, gradual deceleration, and rapid deceleration.

[0030] The reversing input device is used to collect the forward or reverse status of the electric loader and determine the vehicle's driving direction. The reversing input device is electrically connected to the analog input interface of the vehicle controller, collecting the operator's gear shifting and reversing driving intentions and inputting them to the vehicle controller. This allows it to send motor rotation direction and torque signals to the vehicle controller that controls the travel motor; it can also control the high / low speed switching valve on the travel gearbox to achieve high / low speed changes for the vehicle.

[0031] The bucket status detection device is electrically connected to the analog input interface of the intelligent vehicle controller. It inputs the operator's action signals from the bucket's working device to the vehicle controller to detect the bucket's position, levelness, and contact with the load. After comprehensive calculation, the vehicle controller outputs control to the corresponding valve device, controlling the bucket valve to rotate in specified steps, thus achieving full bucket rate control. The motor speed and torque detection device is used to detect the real-time speed and torque status of the travel motor. After comprehensive calculation by the vehicle controller, it simultaneously outputs control to the travel motor vehicle controller, controlling the corresponding travel motor to achieve torque control according to the preset control curve, so as to avoid slippage.

[0032] The vehicle controller, as a control device, is used to determine the difference between the drive axle wheel speed and the travel motor speed based on the accelerator pedal state, taking into account the above input states and the bucket contact load. It determines whether slippage exists and outputs control to reduce the torque of the travel motor to eliminate slippage. If there is no slippage tendency, it accumulates the state time and compares it with the threshold. If it exceeds the set alarm threshold, it issues a motor stall overheat alarm.

[0033] The intelligent instrument prompt device is connected to the intelligent vehicle controller bus to realize data communication and data exchange. It can serve as an input interface for human-machine interaction. It can transmit the step size data of the corresponding operation feeling to the intelligent vehicle controller through the communication bus, and can also read the step size data stored in the memory of the intelligent vehicle controller in the current state through the communication bus and display it on the interface.

[0034] The communication bus is mainly used to enable communication between the above components.

[0035] The system collects the accelerator pedal status, direction status, and current bucket loading status in real time based on the current working conditions and the object being worked on. It detects the contact load status of the electric loader bucket and determines whether the bucket matching control is met. If the bucket matching control is met, the system further collects and compares the current motor speed with the speed of the drive axle tires based on the current accelerator pedal and load status to determine whether the wheels have a tendency to slip. If so, the system determines whether wheel slippage is about to occur based on changes in vehicle speed and travel motor torque. When slippage is imminent, the system performs matching control on the bucket, controlling it to rotate at a preset angle per unit time. The bucket stops after rotating to the preset full bucket angle to ensure the full bucket rate. Simultaneously, the system controls and reduces the torque of the travel motor to ensure that the equipment does not slippage.

[0036] The above-mentioned control measures reduce and prevent vehicle slippage, thereby solving the problems of easy slippage when shoveling material in existing electric loaders, such as poor power matching, poor operational adaptability, easy operator fatigue, excessive energy consumption, and short tire life.

[0037] like Figure 2 As shown, the system's working process is as follows: The vehicle controller acquires the accelerator pedal status, steering status, and bucket status of the electric loader in real time to determine whether the current loading conditions are met. When the accelerator pedal shows an acceleration trend or maintains acceleration, the reversing device is in the forward state, and the bucket is in a horizontal loading state, the system enters the slip control preparation state.

[0038] Meanwhile, the vehicle controller acquires the real-time speed and torque of the travel motor through the motor speed and torque detection device, and performs a comprehensive analysis in conjunction with changes in the overall vehicle speed. When the system detects a decrease in vehicle speed, a continuous increase in motor torque, and a speed approaching zero, it determines that wheel slippage is imminent. It then outputs a control signal to the bucket rotation solenoid valve, controlling the bucket to rotate a preset angle per unit time until it reaches the full bucket angle and stops. Simultaneously, the vehicle controller outputs a torque adjustment command to the travel motor controller, reducing the motor's output torque.

[0039] Through the above system structure and working process, the active identification of slippage trend and the coordinated control of bucket and motor are realized.

[0040] Example 2: like Figure 3 As shown, this embodiment provides a method for controlling the slippage of the material loading wheel of an electric loader, including the following steps: Step 1: The vehicle controller obtains the current accelerator pedal status and direction status of the electric loader to determine the driver's acceleration intention and driving direction.

[0041] Step 2: The vehicle controller acquires the bucket status in real time and determines whether the bucket is in a horizontal loading position. If the bucket is not horizontal, the slip control process is exited.

[0042] Step 3: The vehicle controller determines whether the bucket matching control conditions are met based on the accelerator pedal status, direction status (referring to the vehicle's forward direction), and bucket status. If met, proceed to the next step; otherwise, continue monitoring.

[0043] Step 4: The vehicle controller collects the speed and torque status of the drive motor and analyzes the vehicle speed changes to determine if there is a slippage trend. If a slippage trend exists and slippage is about to occur, Step 5 is triggered; if no slippage trend exists, the status time is accumulated and compared with a preset threshold. When the threshold is exceeded, a motor stall and overheat alarm is issued.

[0044] Step 5: Control the bucket to rotate at a preset angle per unit time, and simultaneously control the travel motor to reduce torque by a preset step size until the bucket rotates to the preset full angle and then stops.

[0045] This method divides the working conditions into three ranges: light load, medium load, and heavy load, based on the bucket load status. In light load mode, the bucket rotates rapidly, and the motor torque step size decreases and is delayed, making the torque slope gentle. In medium load mode, the bucket rotates at a standard speed, and the motor torque decreases in standard steps. In heavy load mode, the bucket rotates slowly, and the motor torque responds and adjusts quickly.

[0046] Through the above control method, this embodiment simultaneously adjusts the bucket cutting angle and the output torque of the travel motor at the critical point where slippage is about to occur, thereby preventing wheel slippage from the source and taking into account the full bucket rate, operating efficiency and energy economy.

[0047] The control process of this scheme can be divided into a condition judgment stage and a slip control stage. Steps one through three above constitute the condition judgment stage, and steps four through five constitute the slip control stage. Each step is described in detail below.

[0048] Step 1: The vehicle controller acquires the current accelerator pedal and direction status of the electric loader. Specifically, the vehicle controller uses a pedal status detection device to collect real-time changes in the accelerator pedal angle to determine the driver's acceleration intention, including rapid acceleration, gradual acceleration, speed maintenance, gradual deceleration, or rapid deceleration. Simultaneously, it obtains the current driving direction (forward or backward) through the reversing input device.

[0049] Step Two: The vehicle controller acquires the bucket status in real time to determine if the bucket is in a horizontal position. Specifically, the vehicle controller obtains the current angle of the bucket through the bucket status detection device to determine if the bucket is in a horizontal loading position. If the bucket is not in a horizontal position, the slip control process exits; if the bucket is in a horizontal position, the next step is performed.

[0050] Step 3: The vehicle controller determines whether the "bucket matching control conditions" are met.

[0051] In this scheme, "bucket matching control condition" refers to the state in which the following four sub-conditions are satisfied simultaneously: Condition A: The bucket is in a horizontal shoveling position; Condition B: The commutation input device detects that the device is in a forward state; Condition C: The accelerator pedal is in an acceleration trend or maintaining the current acceleration state, i.e., it is not decelerating or released; Condition D: The vehicle controller has detected and confirmed the current bucket load status (light load, medium load, or heavy load) through the hydraulic cylinder pressure sensor.

[0052] When all conditions A through D are met, the "bucket matching control condition" is deemed met, and the system enters the skid control preparation state; if any condition is not met, the control process is exited or monitoring continues.

[0053] Step 4: The vehicle controller determines the slippage trend and the state of impending slippage.

[0054] The vehicle controller obtains the real-time speed of the drive motor through a motor speed and torque detection device, and compares it with the wheel-side speed measured by the wheel speed sensor after the transmission ratio is converted. When the theoretical wheel-side speed is significantly higher than the measured wheel-side speed, it is determined that there is a tendency for wheel-side slippage.

[0055] For example, suppose the measured speed of the walking motor is n m The drive axle transmission ratio is i The theoretical wheel-side rotation speed is n m / i If the ratio of the difference between the theoretical wheel-side speed and the measured wheel-side speed to the theoretical wheel-side speed is greater than 5%, it is determined that the wheel-side has a slipping tendency.

[0056] Given the presence of a slippage trend, the vehicle controller further checks whether the following three conditions are met simultaneously: (1) The vehicle speed continues to decrease, specifically: within M consecutive sampling periods (e.g., M=10, corresponding to 0.2s), the vehicle speed in each sampling period is lower than that in the previous sampling period; (2) The torque of the walking motor continues to increase, specifically: within M consecutive sampling periods, the torque of each sampling period is higher than that of the previous sampling period; (3) The vehicle speed approaches zero.

[0057] When all three conditions above are met, it is determined that the wheel edge is about to slip, triggering step five.

[0058] This scheme uses the conditions shown in Table 1 to determine when slippage is imminent, where t is time, v(t) is vehicle speed, and T(t) is the torque of the travel motor. If all three conditions are met consecutively and exceed a preset time threshold (e.g., M consecutive sampling periods), slippage can be determined to be imminent.

[0059] Table 1. Criteria for Judging Slippage Trend

[0060] If there is no slippage trend, or if there is a trend but the above three conditions are not met, the system will continue monitoring without triggering coordinated control. During continuous monitoring, the state time is accumulated and compared with a preset threshold. When the threshold is exceeded, a motor stall over-temperature alarm is issued.

[0061] For example, when the vehicle speed is <0.5km / h, the motor torque is >90% of the rated torque, and the motor speed is <50r / min for 5 seconds, a stall alarm will be issued.

[0062] Step 5: The vehicle controller performs coordinated matching control between the bucket and the travel motor. Specifically, the vehicle controller synchronously executes the following controls based on the current load mode (light load, medium load, or heavy load): Control Strategy A: Control the solenoid valve for bucket rotation to make the bucket rotate a set angle at a preset unit time. In light load mode, it rotates quickly; in medium load mode, it rotates at a standard speed; and in heavy load mode, it rotates slowly. Control Strategy B: Synchronous control of the walking motor reduces torque by a preset step size. In light load mode, the torque step size decreases and is delayed with a gentle slope. In medium load mode, the torque decreases by a standard step size. In heavy load mode, the torque is adjusted quickly in response.

[0063] For example, “In light load mode, the torque adjustment step size in each control cycle (20ms) does not exceed 1% of the rated torque, and it is adjusted once every 5 control cycles (100ms).

[0064] The bucket rotation and motor torque adjustment are synchronized until the bucket rotates to the preset full angle and then stops, ending the slip control process.

[0065] The above five steps constitute the closed-loop active control method for wheel-side slippage during the loading process of electric loaders. Its purpose is to advance the timing of slippage suppression from "passive correction after it has occurred" to "active intervention before it is about to occur," and to balance the relationship between driving force and travel resistance from the source through the coordinated control of the bucket and travel motor.

[0066] In traditional control methods, bucket movement and travel drive are independent of each other. Operators must rely on experience to judge when to release the pedal or adjust the bucket in a very short time. However, the response speed of electric loader motors is much faster than that of fuel-powered systems, leaving the driver with a very short reaction window. This solution uses the vehicle controller to uniformly acquire information on the accelerator pedal, direction, bucket posture, load, and motor status. Under the premise that multiple conditions are met simultaneously, it can identify the typical pre-slip characteristics of "vehicle speed decreases, torque increases, and vehicle speed approaches zero" in advance, thereby initiating coordinated control before slippage occurs.

[0067] Specifically, the active adjustment of the bucket angle in this solution not only completes the loading action but also serves as an "active drag reduction method" to suppress slippage. When the system detects impending slippage, it controls the bucket to rotate upwards at a set speed, effectively reducing the angle at which the bucket cuts into the material, thereby lowering travel resistance. Simultaneously, the travel motor torque is adjusted and reduced according to the load mode to avoid excessive driving force. These two actions are executed synchronously, preventing the tires from losing contact with the ground while ensuring uninterrupted loading.

[0068] Furthermore, this solution matches different control parameters for light, medium, and heavy load modes, solving the problem that a single control strategy cannot accommodate different working conditions. Under light load, the bucket rotates rapidly while the motor torque changes smoothly, allowing for quick loading and avoiding power waste. Under heavy load, the bucket rotates slowly while the motor torque responds quickly, prioritizing sufficient thrust while preventing slippage. This tiered matching strategy enables the electric loader to achieve stable loading performance under different material densities and ground conditions.

[0069] Taking a certain model of loader as an example, the total angle of the bucket rotation from the horizontal position to the full bucket position is 50 degrees. In this scheme, the bucket rotation speed in the standard load mode is preset to Vi = 5° / s, so the theoretical time to rotate to the full bucket position in one go is 50 / Vi = 10 seconds. The bucket rotation speed can be dynamically adjusted according to different load modes. In standard mode (equivalent to medium load), the motor torque adjustment step size is set to △t_std, △t_std≤2%T_rated (motor rated torque), and the control cycle T=20ms.

[0070] In light load mode, the maximum speed of bucket rotation is (Vi+Ap)° / s = 7° / s, with Ap = 2° / s as the adjustment amount. In light load mode, the motor torque adjustment step size is set to Δt_lit, where Δt_lit ≤ 1%T_rated (motor rated torque). The control cycle T = 20ms ensures smooth torque changes, minimizing motor issues and avoiding impact and power waste.

[0071] In heavy-load mode, the maximum rotation speed of the bucket is (Vi-Ap)° / s = 3° / s, and Ap = 2° / s is the adjustment amount. In heavy-load mode, the motor torque adjustment step size is set to △t_hev, △t_hev ≤ 3%T_rated (motor rated torque), and the control cycle is T = 20ms. The torque rises rapidly to prioritize lifting force, while simultaneously using limited-slip control to prevent tire slippage.

[0072] Through the above design, this solution effectively avoids reliance on operator experience and reduces tire wear and increased energy consumption caused by wheel slippage; while suppressing slippage, it ensures full bucket rate and does not sacrifice work efficiency due to reduced power; the coordinated control of the bucket and motor reduces operational intensity and improves driving comfort; at the same time, due to reduced slippage and power waste, the equipment's endurance is extended, achieving a good balance between power, economy, and operational adaptability.

[0073] In this embodiment, the accelerator pedal state is obtained by using an angle sensor installed on the pedal. The driver's driving intention is determined based on the rotation angle of the angle sensor. The rotation angle value of the pedal pressed per unit time can represent the driver's acceleration characteristics, including driving intentions such as rapid acceleration, gradual acceleration, speed maintenance, gradual deceleration, and rapid deceleration.

[0074] The slip control entry condition is met only when the accelerator pedal has an acceleration tendency and maintains the current acceleration state, and the state detected by the reversing input device is forward.

[0075] The vehicle controller obtains the current bucket angle of the electric loader in real time through the angle sensor on the working device and determines whether the bucket is level. Only when the bucket is level and shoveling material is the slip control entry condition met. The working load is obtained by the vehicle controller through the working cylinder pressure sensor, which monitors the load pressure signal of the actuator to determine the current bucket load status.

[0076] When the vehicle controller detects that the accelerator pedal has an acceleration trend and maintains the current acceleration state, the vehicle speed decreases and the torque of the travel motor increases until the vehicle speed approaches 0. It can be determined that the wheel is about to slip, and the bucket is matched and controlled according to this slip state.

[0077] Furthermore, based on the current accelerator pedal status, direction status, and current bucket loading status, it is determined whether the bucket matching control is met. If the bucket matching control is met, the speed and torque status of the travel motor are further collected to determine whether slippage has occurred. When slippage is about to occur, the bucket is matched and controlled to rotate at a preset angle per unit time. After rotating to the preset full bucket angle, it stops. Through the above control, the occurrence of vehicle slippage is reduced and avoided, thus solving the problems of easy slippage when loading material, rough power matching, poor operational adaptability, easy operator fatigue, high energy consumption, and short tire life in existing electric loaders.

[0078] The full bucket angle in this scheme, taking a certain model of loader bucket as an example, is defined as follows: the bucket bottom is placed on a horizontal plane, and the bucket bottom rotates 50° around the horizontal axis under the action of a hydraulic cylinder. This is the full bucket angle, and at this time the ratio of actual loading volume to rated stacking bucket capacity is the largest.

[0079] Based on the load of the equipment's working device, it can be determined that the current load is in one of the three ranges: light load, medium load, or heavy load.

[0080] Light load, medium load, and heavy load are classified according to the rated load capacity of the bucket of the electric loader's working device; for example: A load capacity of less than or equal to 60% of the bucket's rated load capacity is considered a light load. The load capacity is defined as 60% to 85% of the rated load capacity of the bucket, which is considered a medium load. The load capacity exceeding 85% of the bucket's rated load capacity is considered a heavy load, which includes overload conditions.

[0081] The above three loads correspond one-to-one with the rated load capacity of the bucket for electric loaders of different tonnages, and the load loading is pre-stored in the vehicle controller.

[0082] In this embodiment, the rated load capacity of the bucket is the maximum permissible load mass specified on the bucket nameplate.

[0083] If the current load is in light load mode and the bucket matching control is satisfied, the system will further collect and determine whether slippage has occurred based on the travel motor speed and torque status. When slippage is about to occur, the system will perform matching control on the bucket, controlling the bucket to rotate rapidly at a preset angle per unit time. After rotating to the preset full bucket angle, the bucket will stop. Simultaneously, the motor torque change step size will be reduced and delayed according to the preset light load mode, making the torque slope smoother, thereby improving the full bucket rate and control responsiveness of the electric loader.

[0084] If the current load is in standard mode and the bucket matching control is met, the system will further collect and determine whether slippage has occurred based on the travel motor speed and torque status. When slippage is about to occur, the system will perform matching control on the bucket, controlling the bucket to rotate a set angle according to a preset unit time standard. The bucket will stop after rotating to the preset full bucket angle. At the same time, the travel motor torque change step size will also decrease according to the standard step size, thereby improving the full bucket rate and operating efficiency of the electric loader.

[0085] If the current load is in heavy-load mode and the bucket matching control is satisfied, the system will further collect and determine whether slippage has occurred based on the travel motor speed and torque status. When slippage is about to occur, the system will perform matching control on the bucket, controlling the bucket to slowly rotate a set angle according to a preset unit time. After rotating to the preset full bucket angle, the system will stop. Simultaneously, the system will match the travel motor torque correspondence with the throttle pedal travel distance, so that the motor torque is adjusted according to the rapid step size, improving the motor torque response, thereby increasing the full bucket rate of the electric loader and reducing slippage.

[0086] This makes the power matching of the electric loader more suitable for the load, which not only ensures the full bucket rate and operating efficiency of the equipment, but also ensures the power output responsiveness of the equipment, reduces and avoids slippage, improves the operating efficiency of the equipment, saves power consumption, and extends the equipment's endurance and tire life.

[0087] The step size for motor torque variation is designed and stored in the vehicle controller. Operators can manually set this step size according to their needs and to meet different operating conditions, thereby achieving the best control effect that matches the power required for the operating conditions.

[0088] Different step size data can be retrieved through different modes set in the interface of the intelligent instrument prompt device, making it convenient for operators to operate.

[0089] The vehicle controller can be a readable storage medium that stores the vehicle control program and various preset data values, as well as data collected by various sensors, and the output control of the bucket rotation solenoid valve and the travel motor vehicle controller.

[0090] The above are merely preferred embodiments of this solution and are not intended to limit the solution. Various modifications and variations can be made to this solution by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this solution should be included within the scope of protection of this solution.

Claims

1. A method for controlling the slippage of the material loading wheel of an electric loader, characterized in that, Includes the following steps: Obtain the current accelerator pedal status, overall vehicle direction status, and bucket status of the electric loader; When the bucket matching control conditions are met, the presence of slippage trend is determined based on the travel motor speed and torque status, combined with the overall vehicle speed. The bucket matching control conditions include the bucket being in a horizontal position, the vehicle being in a forward direction, the accelerator pedal being in an acceleration or maintaining an acceleration trend, and the current load status of the bucket being detected. When a slippage tendency exists, the following control strategy is executed synchronously based on the current bucket load status: The bucket rotates at a preset angle towards the full bucket position within a preset unit of time. The walking motor reduces torque by a preset step size; The bucket stops rotating after reaching the preset full-bucket angle.

2. The method for controlling the slippage of the material loading wheel of an electric loader as described in claim 1, characterized in that, The load conditions of the bucket are divided into three ranges: light load, medium load, and heavy load, based on the rated load capacity of the bucket.

3. The method for controlling the slippage of the material loading wheel of an electric loader as described in claim 2, characterized in that, Depending on the load conditions, the bucket rotates at different angles within a preset unit of time; the bucket rotates fastest in light load mode, slowest in heavy load mode, and between light load and heavy load mode in medium load mode.

4. The method for controlling the slippage of the material loading wheel of an electric loader as described in claim 4, characterized in that, Depending on the load conditions, the preset step size for reducing the torque of the walking motor varies; in light load mode, the motor torque step size is the smallest and accompanied by a delay; in medium load mode, the motor torque step size is the standard step size; and in heavy load mode, the motor torque step size is the largest and there is no delay.

5. The method for controlling the slippage of the material loading wheel of an electric loader as described in claim 1, characterized in that, Determining the slip trend includes: The measured speed of the walking motor is converted into the theoretical wheel speed through the transmission ratio and compared with the wheel speed measured by the wheel speed sensor. When the theoretical wheel speed exceeds the set percentage of the measured wheel speed, it is determined that there is a slippage trend of the wheel. When there is a tendency for wheel slippage, if the vehicle speed continues to decrease, the torque of the drive motor continues to increase, and the vehicle speed approaches zero, it is determined that wheel slippage is about to occur.

6. The method for controlling the slippage of the material loading wheel of an electric loader as described in claim 1, characterized in that, The full bucket angle is the angle between the bucket opening plane and the horizontal plane when the bucket is in its normal load-bearing posture after being loaded with material. This angle is pre-stored in the storage unit of the vehicle controller.

7. The method for controlling the slippage of the material loading wheel of an electric loader as described in claim 1, characterized in that, When the bucket matching control conditions are not met, the vehicle controller continuously monitors the accelerator pedal status, direction status, and bucket status, and does not activate the slip control.

8. The method for controlling the slippage of the material loading wheel of an electric loader as described in claim 1, characterized in that, When there is no slippage trend, the vehicle controller accumulates the current state over time and compares it with the preset stall alarm threshold. When the accumulated time exceeds the threshold, a motor stall over-temperature alarm is issued.

9. The method for controlling the slippage of the material loading wheel of an electric loader as described in claim 1, characterized in that, The bucket rotation action is executed by a bucket rotation action solenoid valve, which uses PWM proportional control; the torque control of the travel motor is executed by the travel motor controller.

10. A material loading wheel-side slip control system for an electric loader, used to implement the material loading wheel-side slip control method for an electric loader as described in claim 1, characterized in that, include; Vehicle controller; The pedal status detection device is electrically connected to the vehicle controller and is used to collect the status of the accelerator pedal; The reversing input device is electrically connected to the vehicle controller and is used to collect the vehicle's directional status. The bucket status detection device is electrically connected to the vehicle controller and is used to collect bucket status data. The motor speed and torque detection device is electrically connected to the vehicle controller and is used to collect the speed and torque status of the walking motor. The bucket rotation solenoid valve is electrically connected to the output of the vehicle controller and is used to control the bucket rotation. The vehicle controller is configured to: when the bucket matching control conditions are met, determine whether there is a slippage trend based on the travel motor speed and torque status and the overall vehicle speed; The bucket matching control conditions include the bucket being in a horizontal position, the vehicle being in a forward direction, the accelerator pedal being in an acceleration or maintaining an acceleration trend, and the current load status of the bucket being detected. When there is a tendency to slip, the vehicle controller synchronously executes the following control according to the current bucket load status: the bucket is controlled to rotate at a preset angle in the direction of full bucket angle by the bucket rotation action solenoid valve, and at the same time the travel motor is controlled to reduce torque by a preset step size until the bucket rotates to the preset full bucket angle and then stops.

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