An Adaptive Steep Slope Descent Control Method and System for Mining Dump Trucks

Abstract

This invention proposes an adaptive steep slope descent control method and system for mining dump trucks. The method collects vehicle data in real time, detects whether the driver operates the downhill descent gear switch, and calculates the final target vehicle speed. Based on preset load ranges and slope ranges, as well as the real-time total vehicle mass and a dual-source slope calculation and verification mechanism, control algorithm parameters are obtained by interval matching. Feedforward torque is obtained based on the control algorithm parameters. Subsequently, a dual-loop cascade PI control structure is used to adjust the output feedback braking torque, which is combined with the feedforward torque to form the final target torque and sent to the motor controller to drive the motor. Under the premise of pure motor braking without intervention of mechanical braking, precise downhill constant speed control is achieved, maximizing energy recovery efficiency, while also ensuring rapid speed adjustment response and smooth driving, making it suitable for mining transportation scenarios.

Description

Technical Field

[0001] This invention relates to the field of electric drive control technology for mining vehicles, and in particular to an adaptive steep slope descent control method and system for mining dump trucks. Background Technology

[0002] In open-pit mining operations, mining dump trucks are the core transportation equipment, characterized by alternating long uphill and downhill sections, steep gradients, and long durations. With the advancement of electrification in mining equipment, electric mining dump trucks can significantly reduce operating energy consumption and costs by recovering downhill potential energy through electric motor braking. In long downhill operations, precise control to achieve constant speed descent using pure electric braking not only maximizes energy recovery efficiency but also significantly reduces wear on mechanical brake pads and driver workload, thereby improving the stability and safety of mining transportation operations.

[0003] Currently, vehicle hill descent control technology has been widely applied in passenger cars, general commercial vehicles, and light electric vehicles, resulting in a variety of mature control solutions. However, existing vehicle hill descent control technologies generally suffer from poor adaptability to operating conditions, low control accuracy, insufficient dynamic response performance, and inability to adapt to extreme load fluctuations and complex mining road conditions. Specifically, these shortcomings are: First, they are not adapted to the extreme load fluctuation characteristics of mining trucks, failing to meet the control requirements of both empty and heavy-load conditions. Furthermore, the control logic does not match the specific operating habits of mining trucks, affecting the driver's operational continuity. Second, the reliability of slope recognition is insufficient. Single-sensor solutions are prone to deviations due to interference from bumpy mining road surfaces, while sensorless solutions have limited estimation accuracy and lack a verification mechanism, especially under long downhill continuous working conditions where the slope recognition result has a large error. Third, the control algorithm architecture is rudimentary. Single-loop PI regulation has an inherent contradiction between response speed and stability, lacks multi-parameter feedforward compensation, and cannot achieve stable constant speed control with pure electric braking and zero mechanical braking intervention.

[0004] Therefore, there is an urgent need to develop an adaptive steep slope descent control technology that is suitable for the characteristics of mining dump trucks, such as large load fluctuations and long slope operations. Summary of the Invention

[0005] To address the aforementioned technical problems, this application proposes an adaptive steep slope descent control method for mining dump trucks, comprising the following steps:

[0006] S1: Collect vehicle data in real time and determine whether the preset activation conditions are met based on the vehicle data; when the preset activation conditions are met, activate the adaptive hill descent control function and allow operation of the downhill descent gear switch.

[0007] The vehicle data includes driving operation signals, vehicle operating status data, and system fault status.

[0008] Furthermore, the preset activation conditions include: the vehicle is in forward gear, and the vehicle speed and gradient in the vehicle operation status data are within the preset downhill working condition range; the driving operation signal satisfies that the brake pedal is not triggered; the system fault status satisfies that the motor system and drive system are fault-free, and the gradient and load detection modules are normal.

[0009] S2: Real-time acquisition of the total vehicle mass, and preset division of multiple load ranges, then matching the corresponding load range according to the total vehicle mass to obtain the matched load range; and also using a dual-source slope calculation and verification mechanism to obtain the current vehicle's running slope, and preset division of multiple slope ranges, then matching the corresponding slope range according to the current vehicle's running slope to obtain the matched slope range.

[0010] Ideally, when dividing the load range, it should be divided into three load ranges: unloaded, half-loaded, and heavily loaded.

[0011] The dual-source slope calculation and verification mechanism comprehensively considers both direct measurement and calculation based on the vehicle's longitudinal dynamics equations to determine the current vehicle's operating slope.

[0012] Furthermore, the first path of the dual-source slope calculation and verification mechanism directly acquires the vehicle's longitudinal tilt angle through a tilt sensor / inertial measurement unit (IMU) and converts it into a directly measured slope value; the second path calculates the dynamic estimated slope value based on the vehicle's longitudinal dynamic equation, combined with the real-time acquired vehicle speed, total vehicle mass, and motor output torque; the difference between the directly measured slope value and the dynamic estimated slope value is verified, and if the difference is within the allowable threshold, the average of the two is taken as the current vehicle's operating slope; if the difference exceeds the allowable threshold, the sensor is determined to be abnormal, the valid operating slope value of the previous frame is used as the current vehicle's operating slope, and a fault is reported.

[0013] Furthermore, the vehicle longitudinal dynamics equation is as follows: ; in, The real-time measured torque is the actual output torque of the motor, m is the real-time measured total mass of the vehicle, and g is the acceleration due to gravity. The slope value is estimated for the dynamics to be solved, where f is the rolling resistance coefficient and r is the wheel rolling radius. For the gearbox speed ratio, Main reduction ratio, For transmission efficiency.

[0014] S3: Detect whether the driver has operated the downhill slow-down gear switch, and calculate the final target speed based on the detection results.

[0015] Furthermore, when the driver is detected operating the downhill descent control switch, the preset target speed corresponding to the current downhill descent control gear is preferentially used as the final target speed; when the driver is not detected operating the downhill descent control switch, the feedforward preset speed is calculated based on the matching load range and the matching slope range, and the feedforward preset speed is linearly fine-tuned within the set range based on the accelerator pedal opening to obtain the final target speed, while setting the upper and lower limit thresholds of the final target speed.

[0016] S4: Based on the matching load range and matching slope range, the feedforward torque is obtained directly from a pre-calibrated two-dimensional parameter table. .

[0017] The feedforward torque The steady-state slope compensation torque is used to counteract the main component of the slope sliding force under the current working condition; the current working condition refers to the combination of the matching slope range and the matching load range matched in step S2.

[0018] Furthermore, the feedforward torque is updated only as the matched load range and matched slope range are updated. During the update, the feedforward torque is updated again by looking up the table according to the pre-calibrated two-dimensional parameter table. When the vehicle does not leave the current working condition, that is, when the matched load range and matched slope range do not change, the feedforward torque remains fixed and does not need to be calculated in real time for each frame.

[0019] S5: A cascaded PI control structure is adopted, and the braking torque is output by the PI controller based on the vehicle operating status data in the collected vehicle data and the final target vehicle speed. .

[0020] Furthermore, the feedback braking torque It includes an outer velocity loop and an inner acceleration loop; The outer speed loop takes the deviation between the final target vehicle speed and the actual collected vehicle speed as input, and outputs the target acceleration through a PI regulator. It is responsible for ensuring the steady-state tracking accuracy of the vehicle speed and realizing constant speed control. The inner acceleration loop takes the deviation between the target acceleration and the vehicle acceleration in the actual collected vehicle operating status data as input, and outputs the feedback braking torque value through the PI regulator. It is responsible for quickly responding to dynamic changes in vehicle speed, limiting the peak values ​​of acceleration and deceleration, avoiding sudden changes in vehicle speed and power shocks, and ensuring driving stability. The control parameters of the PI regulator are switched and matched in real time according to the current operating conditions.

[0021] S6: The vehicle controller adds the feedforward torque and the feedback braking torque to obtain the total target braking torque. Meanwhile, the total target braking torque is limited at both the upper and lower limits to obtain the final target torque, which is then sent to the motor controller to drive the motor to perform regenerative braking, thus achieving constant speed downhill braking under pure motor braking.

[0022] Right now ; Furthermore, the upper and lower limit processing specifically refers to limiting the total target braking torque within the range of the motor's maximum regenerative braking torque and maximum driving torque, ensuring that the command for the final target torque is within the motor's executable range.

[0023] S7: Monitors in real time whether the vehicle meets the exit trigger conditions of the adaptive hill descent control function. If the exit trigger conditions are met, the adaptive hill descent control function will be exited.

[0024] Furthermore, the exit trigger conditions include braking pedal being depressed, accelerator pedal opening exceeding a preset threshold, gear shifting, adaptive hill descent control function being turned off, and system malfunction; when any one of the exit trigger conditions is met, the adaptive hill descent control function is triggered to exit, and at this time the vehicle torque is controlled to smoothly transition to normal driving mode to avoid power shock.

[0025] To address the aforementioned technical problems, this application also proposes an adaptive steep slope descent control system for mining dump trucks, the system comprising a perception layer, a decision control layer, and an execution layer. The perception layer includes a driving intention acquisition unit, a vehicle status acquisition unit, a slope detection unit, and a load detection unit; The driving intention acquisition unit includes a downhill descent gear switch, an accelerator pedal sensor, and a brake pedal sensor, which are used to identify and acquire the driver's driving operation signals. The slope detection unit includes an inertial measurement unit and a tilt sensor, used to collect the longitudinal tilt angle of the vehicle; The load detection unit is an on-board weighing system (suspension pressure type / strain type) used to collect the total mass of the vehicle in real time. The vehicle status acquisition unit is used to acquire vehicle operating conditions, including motor speed and battery status, as well as operating parameters, including vehicle speed and vehicle acceleration.

[0026] The decision control layer is integrated into the vehicle controller (VCU) and is the core of the system. It includes a functional status management unit, a target speed adaptive unit, a load parameter matching unit, a slope verification and parameter matching unit, a cascade PI adjustment unit, and a torque synthesis and limiting unit. The functional status management unit is used for the activation, deactivation, and status switching logic judgment of the adaptive steep slope descent function. The target vehicle speed adaptive unit is used to perform gear-priority driving intention parsing and calculate the final target vehicle speed; The load parameter matching unit is used for dividing and matching the corresponding load ranges; The slope verification and parameter matching unit is used for dual-source slope calculation verification, slope interval division and matching of corresponding slope intervals; The cascaded PI control unit has a built-in dual-loop controller with an outer speed loop and an inner acceleration loop, which outputs feedback braking torque. The torque synthesis and limiting unit is used to synthesize the feedforward torque and the feedback braking torque into a total target braking torque, and to perform upper and lower limiting processing on the total target braking torque to output the final target torque.

[0027] The execution layer consists of a motor controller (MCU) and a drive motor assembly, used to receive the final target torque and perform electric braking; it also includes a mechanically redundant braking execution unit, which intervenes only when the electric braking force is insufficient under extreme operating conditions.

[0028] The beneficial effects of the adaptive steep slope descent control method and system for mining dump trucks of the present invention are as follows: (1) It conforms to the working conditions of mining trucks. In view of the characteristics of large load fluctuation and complex slope of mining trucks, it realizes the three-dimensional adaptation of driving needs, slope and load. At the driving level, it takes into account both gear speed setting and pedal fine adjustment, which is in line with the operating habits of mining truck drivers; the load is based on real-time recognition and adapts to the mass change of more than one times from empty load to heavy load; the control parameters are optimal under all working conditions to avoid insufficient or excessive braking force; at the same time, the motor capacity limit is set on the torque output, and mechanical braking redundancy is reserved in extreme working conditions, taking into account energy saving and driving safety, and adapting to the harsh working environment of mines; (2) The slope detection adopts a dual-source calculation and verification mechanism to improve the recognition accuracy. When a single sensor fails, it can still maintain the function operation and ensure the reliability of the slope recognition result; (3) The combination of feedforward torque and cascade PI dual-loop control takes into account both response speed and stability. The feedforward torque is updated in real time based on load and slope, which offsets the main component of the downhill force in advance and greatly improves the control response speed. In the cascade PI dual-loop structure, the outer loop speed loop constrains the acceleration impact to ensure smooth driving, and the inner loop acceleration loop accurately tracks the target vehicle speed. The two work together to achieve fast response, no overshoot, and small fluctuation constant speed control, and achieve minimal vehicle speed fluctuation under long downhill conditions. (4) Through precise torque control, under normal downhill conditions, the constant speed downhill is maintained entirely by motor braking, with zero mechanical braking intervention, maximizing the conversion of downhill potential energy into electrical energy to be fed back to the power battery, significantly improving vehicle economy. At the same time, it greatly reduces the wear of mechanical brake friction pads, reducing the operation and maintenance costs of mining vehicles and the labor intensity of drivers. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the overall process of an adaptive steep slope descent control method for mining dump trucks according to the present invention; Figure 2is a schematic diagram of the cascade PI regulation structure and the control logic of the vehicle controller in steps S5 and S6 of the adaptive steep slope downhill control method for a mining dump truck according to the present invention; Figure 3 is an architectural block diagram of the adaptive steep slope downhill control system for a mining dump truck according to the present invention. DETAILED DESCRIPTION

[0030] To further understand the objectives, structure, features and functions of the present invention, the detailed description is given below in conjunction with embodiments.

[0031] Embodiment: The present invention provides an adaptive steep slope downhill control method for a mining dump truck, as Figure 1 shown, which is an overall flow schematic diagram of the method. In this embodiment, an electric mining dump truck with a rated load capacity of 120 tons is taken as the application object, the no-load total vehicle mass is 70 tons, the full-load total vehicle mass is 190 tons, the truck is equipped with a driving motor with a rated power of 1000kW, the maximum regenerative braking torque is 6000N·m, and the maximum driving torque is 7000N·m.

[0032] In this embodiment, let the total vehicle mass be m and the actually measured slope gradient be θ, the following three load intervals are preset: no-load interval (m ≤ 80 tons), half-load interval (80 tons < m < 170 tons), full-load interval (m ≥ 170 tons); and the following three slope gradient intervals are preset: gentle slope interval (3° ≤ θ < 7°), medium slope interval (7° ≤ θ < 12°), steep slope interval (θ ≥ 12°).

[0033] The pre-calibrated two-dimensional parameter table (slope gradient-load two-dimensional parameter table) in this embodiment is as follows (unit: N·m), which reflects the feedforward torque values under the working condition combinations of different slope gradient intervals and load intervals: Unloaded -650 -1080 -1420 Half a year -1120 -1450 -1960 Heavy load -1380 -1800 -2350 the absolute value of the feedforward torque under all working conditions in the table is far lower than the maximum regenerative braking torque of 6000N·m of the motor, there is still sufficient margin after superimposing the dynamic feedback torque, which can ensure the feasibility of pure motor braking under all working conditions, and mechanical braking is not required to intervene on normal slopes.

[0034] For example, when step S1 is executed, the vehicle speed, gear, pedal signal, slope gradient and system fault status are collected in real time. When the following conditions are met: the vehicle is in forward driving condition, the vehicle speed is 5~40km / h, the slope gradient is greater than or equal to 3° in the downhill direction, the opening of the brake pedal is 0, and the motor and the driving system have no faults, the adaptive steep slope downhill function is formally activated.

[0035] For example, when step S2 is executed, the total vehicle mass m is collected in real time by the on-board weighing system.

[0036] In this embodiment, the total mass of the vehicle is m=190 tons, and the matched load range is determined to be the heavy load range.

[0037] The IMU collects the vehicle's longitudinal tilt angle, which is then converted into a directly measurable slope value. ; Real-time data collection of vehicle speed v and motor output torque The total mass of the vehicle is m. Substituting this into the following dynamic equation and solving it inversely, we can obtain the estimated slope. : ; Calculate the difference If the difference If the gradient is ≤1°, then the final gradient of the current vehicle's operation is... If the difference If the slope is greater than 1°, the sensor is determined to be abnormal. The effective slope of the previous frame is retained as the current operating slope of the vehicle, and a fault warning is triggered.

[0038] Then, the current vehicle's running gradient is matched with the defined gradient range to obtain the matched gradient range.

[0039] For example, when performing step S3, the status of the downhill descent gear switch is detected first. In this embodiment, three downhill descent gears, L1, L2 and L3, are set, corresponding to preset target vehicle speeds of 8km / h, 15km / h and 25km / h, respectively.

[0040] If the driver engages any downhill descent gear, the preset target speed corresponding to the downhill descent gear will be used directly as the final target speed. If the driver does not activate the downhill descent control switch, the load correction coefficient and slope correction coefficient are obtained based on the matched load range and matched slope range, and then the feedforward preset speed is calculated. The calculation formula is: ; In the formula, The maximum speed for deceleration is designed to be 30 km / h. The load correction factor is 1.0 for unloaded, 0.8 for half-loaded, and 0.6 for heavy load. The slope correction factor is 1.0 for gentle slopes, 0.7 for medium slopes, and 0.5 for steep slopes.

[0041] In this embodiment, the vehicle is heavily loaded, and the gradient is 10° (medium slope section). The feedforward preset vehicle speed is calculated. = 30 × 0.6 × 0.7 = 12.6 km / h. Based on this, when the accelerator pedal opening is 0%, the feedforward preset speed value is maintained. When the accelerator pedal opening is between 0% and 30%, the feedforward preset speed is linearly adjusted upward as the accelerator pedal opening increases. When the accelerator pedal opening exceeds 30%, the adaptive hill descent control function is deactivated, and normal driving needs are responded to.

[0042] For example, when performing step S4, in this embodiment, the matched load range is the heavy load range, and the matched slope range is the medium slope range. Based on the two-dimensional combination of the heavy load range and the medium slope range, the feedforward torque is obtained by querying a pre-calibrated two-dimensional parameter table. = -1800 N·m; When the load range and the medium-slope range are not exceeded, the feedforward torque value remains unchanged and does not require real-time calculation for each frame.

[0043] For example, when performing step S5, a cascaded PI control structure of an outer loop speed loop and an inner loop acceleration loop is used to output feedback braking torque. Specifically: The input to the outer speed loop is the deviation of the final target vehicle speed (12.6 km / h in this embodiment) obtained by S3 from the actual vehicle speed (13.1 km / h in this embodiment) by 0.5 km / h. Based on the speed loop PI parameters corresponding to the heavy-load medium slope, the PI regulator calculates and outputs the target acceleration as -0.2 m / s² (the negative sign indicates the direction of deceleration).

[0044] The input to the inner acceleration loop is the deviation of the target acceleration of -0.2m / s² from the actual collected acceleration of 0.1m / s², which is -0.3m / s². After calculation by the acceleration loop PI parameters, the output feedback braking torque value is -150N·m, which is used to quickly correct the acceleration deviation and suppress the upward trend of vehicle speed.

[0045] Specifically, each slope range corresponds to different velocity loop and acceleration loop PI parameters.

[0046] By controlling the steady-state accuracy of vehicle speed through the outer ring and the dynamic stability through the inner ring, speed regulation can be both fast and stable.

[0047] For example, when performing step S6, the vehicle controller adds the fixed feedforward torque and the feedback braking torque as the total target braking torque. ,Right now = -1800 + (-150) = -1950 N·m.

[0048] The absolute value is much smaller than the motor's maximum regenerative braking torque and maximum driving torque, and is within the safe operating range of the motor, so no amplitude limiting is required.

[0049] The vehicle controller sends the total target braking torque to the motor controller via the CAN bus. The motor then performs regenerative braking, converting mechanical energy into electrical energy to feed back into the power battery.

[0050] During a continuous long downhill process, if the measured gradient and load do not change within a certain range, the feedforward torque remains fixed, and only the feedback braking torque is dynamically adjusted with the vehicle speed. When the measured gradient or load crosses the boundary of the range, the system smoothly updates the feedforward torque value to maintain the vehicle speed within the allowable error range of the target value, without the need for mechanical braking intervention throughout the process.

[0051] The cascade PI control structure in steps S5 and S6 is related to the control logic of the vehicle controller as follows: Figure 2 As shown.

[0052] For example, when performing step S7, if the driver presses the brake pedal or the accelerator pedal with an opening exceeding a preset threshold of 30%, the adaptive hill descent control function is turned off, or a system malfunction occurs, the adaptive hill descent control function is triggered and exited, controlling the vehicle torque to smoothly transition to the torque corresponding to the normal driving mode within 500ms, thus avoiding vehicle jerking or impact.

[0053] This invention also proposes an adaptive steep slope descent control system for mining dump trucks, used to execute the aforementioned adaptive steep slope descent control method for mining dump trucks. The system architecture is as follows: Figure 3 As shown, it is divided into a perception layer, a decision control layer, and an execution layer.

[0054] The perception layer includes the following: The driving intent acquisition unit includes a downhill descent gear switch, an accelerator pedal sensor, a brake pedal sensor, and a descent function button. All signals are connected to the vehicle controller's I / O port or CAN bus. The slope detection unit includes a six-axis inertial measurement unit (IMU), a tilt sensor, and a wheel speed sensor. The IMU is mounted at the center of gravity of the vehicle frame and outputs longitudinal tilt angle and acceleration signals. The load detection unit is a suspension hydraulic cylinder pressure sensor, which is arranged in the front and rear axle suspension cylinders to calculate the total vehicle weight through hydraulic pressure. The vehicle status acquisition unit acquires the motor speed and output torque output by the motor controller, as well as the voltage, current, vehicle speed, and acceleration signals output by the battery management system.

[0055] The decision control layer is integrated within the vehicle controller (VCU) and includes the following: The functional status management unit stores the activation and deactivation logic of the adaptive steep slope descent function, and manages the four states of the adaptive steep slope descent function: standby, running, fault, and deactivation. The target vehicle speed adaptive unit has a built-in downhill descent gear-vehicle speed mapping table and an accelerator pedal opening-vehicle speed linear algorithm to output the final target vehicle speed. The load parameter matching unit performs load range division and determination, and also stores the load range; The slope verification and parameter matching unit performs dual-source slope calculation verification and slope interval division and determination, and also stores the slope intervals; Cascade PI control unit: includes an acceleration loop PI controller and a speed loop PI controller, supporting online parameter switching; The torque synthesis and limiting unit completes the superposition of feedforward torque and feedback braking torque, and performs upper and lower limiting processing on the superimposed total target braking torque.

[0056] The execution layer includes the following: The motor controller and drive motor assembly receive the final target torque and perform electric drive / electric braking on it to achieve energy recovery; The mechanically redundant braking actuator is controlled by the vehicle controller and only intervenes when the electric braking force is insufficient under extreme conditions, serving as a safety redundancy.

[0057] This invention enables constant-speed downhill driving under pure electric braking with zero mechanical braking intervention, maximizing energy recovery efficiency while reducing driver workload and mechanical brake wear, significantly improving the operational economy and reliability of electric mining trucks.

[0058] The present invention has been described in the above-described embodiments; however, these embodiments are merely examples for implementing the present invention. It must be noted that the disclosed embodiments do not limit the scope of the present invention. Conversely, any modifications and refinements made without departing from the spirit and scope of the present invention are within the scope of patent protection of the present invention.

[0059] The contents of this invention not described in detail are existing technologies known to those skilled in the art.

Claims

1. A method for adaptive steep slope descent control of mining dump trucks, characterized in that, Includes the following steps: S1: Collect vehicle data in real time and determine whether the preset activation conditions are met based on the vehicle data; when the preset activation conditions are met, activate the adaptive hill descent control function and allow operation of the downhill descent gear switch. The vehicle data includes driving operation signals, vehicle operating status data, and system fault status. S2: Real-time acquisition of the total vehicle mass, and preset division of multiple load ranges, then matching the corresponding load range according to the total vehicle mass to obtain the matched load range; and also using a dual-source slope calculation and verification mechanism to obtain the current vehicle's running slope, and preset division of multiple slope ranges, then matching the corresponding slope range according to the current vehicle's running slope to obtain the matched slope range. The dual-source slope calculation and verification mechanism comprehensively considers both direct measurement and calculation based on the vehicle's longitudinal dynamics equations to determine the current vehicle's operating slope. S3: Detect whether the driver has operated the downhill slow-down gear switch, and calculate the final target speed based on the detection results; S4: Based on the matching load range and matching slope range, the feedforward torque is obtained directly from a pre-calibrated two-dimensional parameter table. ; S5: A cascaded PI control structure is adopted, and the braking torque is output by the PI controller based on the vehicle operating status data in the collected vehicle data and the final target vehicle speed. ; S6: The vehicle controller adds the feedforward torque and the feedback braking torque to obtain the total target braking torque. Meanwhile, the total target braking torque is subjected to upper and lower limit processing to obtain the final target torque, and the final target torque is sent to the motor controller to drive the motor to perform regenerative braking, thereby achieving constant speed downhill under pure motor braking. S7: Monitors in real time whether the vehicle meets the exit trigger conditions of the adaptive hill descent control function. If the exit trigger conditions are met, the adaptive hill descent control function will be exited.

2. The method according to claim 1, characterized in that, The preset activation conditions include: the vehicle is in forward gear, and the vehicle speed and gradient in the vehicle operation status data are within the preset downhill working condition range; the driving operation signal satisfies that the brake pedal is not triggered; the system fault status satisfies that the motor system and drive system are fault-free, and the gradient and load detection modules are normal.

3. The method according to claim 1, characterized in that, The first path of the dual-source slope calculation and verification mechanism directly collects the vehicle's longitudinal tilt angle and converts it into a directly measured slope value; the second path is based on the vehicle's longitudinal dynamic equation, combined with the real-time collected vehicle speed, total vehicle mass, and motor output torque to calculate a dynamically estimated slope value; the directly measured slope value and the dynamically estimated slope value are checked for difference, and if the difference is within the allowable threshold, the average of the two is taken as the current vehicle's operating slope; If the difference exceeds the allowable threshold, the sensor is determined to be abnormal. The valid running slope value of the previous frame is used as the current running slope of the vehicle, and the fault is reported.

4. The method according to claim 1, characterized in that, In step S3, when it is detected that the driver operates the downhill descent gear switch, the preset target speed corresponding to the current downhill descent gear is preferentially used as the final target speed; when it is not detected that the driver operates the downhill descent gear switch, the feedforward preset speed is calculated based on the matching gradient range and the matching load range, and the feedforward preset speed is linearly fine-tuned within the set range based on the accelerator pedal opening to obtain the final target speed, while setting the upper and lower limit thresholds of the final target speed.

5. The method according to claim 3, characterized in that, The vehicle longitudinal dynamics equation is: ； In the formula, The real-time measured torque is the actual output torque of the motor, m is the real-time measured total mass of the vehicle, and g is the acceleration due to gravity. The slope value is estimated for the dynamics to be solved, where f is the rolling resistance coefficient and r is the wheel rolling radius. For the gearbox speed ratio, Main reduction ratio, For transmission efficiency.

6. The method according to claim 1, characterized in that, The feedforward torque is updated only as the matched load range and matched slope range are updated. During the update, the feedforward torque is updated again by looking up the table according to the pre-calibrated two-dimensional parameter table. When the vehicle does not leave the current working condition, that is, when the matched load range and matched slope range do not change, the feedforward torque remains fixed and does not need to be calculated in real time for each frame.

7. The method according to claim 1, characterized in that, The feedback braking torque includes an outer velocity loop and an inner acceleration loop; The outer speed loop takes the deviation between the final target vehicle speed and the actual collected vehicle speed as input, and outputs the target acceleration through a PI regulator. It is responsible for ensuring the steady-state tracking accuracy of the vehicle speed and realizing constant speed control. The inner acceleration loop takes the deviation between the target acceleration and the vehicle acceleration in the actual collected vehicle operating status data as input, and outputs the feedback braking torque value through the PI regulator. It is responsible for quickly responding to dynamic changes in vehicle speed, limiting the peak values ​​of acceleration and deceleration, avoiding sudden changes in vehicle speed and power shocks, and ensuring driving stability. The control parameters of the PI regulator are switched and matched in real time according to the current operating conditions.

8. The method according to claim 1, characterized in that, In step S6, the upper and lower limit processing specifically refers to limiting the total target braking torque within the range of the motor's maximum regenerative braking torque and maximum driving torque, ensuring that the command for the final target torque is within the motor's executable range.

9. The method according to claim 1, characterized in that, The exit trigger conditions include braking pedal being depressed, accelerator pedal opening exceeding a preset threshold, gear shifting, adaptive hill descent control function being turned off, and system malfunction. When any one of the exit trigger conditions is met, the adaptive hill descent control function is triggered to exit, and the vehicle torque is smoothly transitioned to normal driving mode to avoid power shock.

10. An adaptive steep slope descent control system for a mining dump truck, characterized in that, It includes the perception layer, the decision control layer, and the execution layer; The perception layer includes a driving intention acquisition unit, a vehicle status acquisition unit, a slope detection unit, and a load detection unit; The driving intention acquisition unit includes a downhill descent gear switch, an accelerator pedal sensor, and a brake pedal sensor, which are used to identify and acquire the driver's driving operation signals. The slope detection unit includes an inertial measurement unit and a tilt sensor, used to collect the longitudinal tilt angle of the vehicle; The load detection unit is an on-board weighing system used to collect the total mass of the vehicle in real time; The vehicle status acquisition unit is used to acquire vehicle operating conditions including motor speed and battery status, as well as operating parameters including vehicle speed and vehicle acceleration. The decision control layer is integrated into the vehicle controller and is the core of the system. It includes a functional status management unit, a target speed adaptive unit, a load parameter matching unit, a slope verification and parameter matching unit, a cascade PI adjustment unit, and a torque synthesis and limiting unit. The functional status management unit is used for the activation, deactivation, and status switching logic judgment of the adaptive steep slope descent function. The target vehicle speed adaptive unit is used to perform gear-priority driving intention parsing and calculate the final target vehicle speed; The load parameter matching unit is used for dividing and matching the corresponding load ranges; The slope verification and parameter matching unit is used for dual-source slope calculation verification, slope interval division and matching of corresponding slope intervals; The cascaded PI control unit has a built-in dual-loop controller consisting of an outer acceleration loop and an inner speed loop, which outputs feedback braking torque. The torque synthesis and limiting unit is used to synthesize the feedforward torque and the feedback braking torque into a total target braking torque, and to perform upper and lower limiting processing on the total target braking torque to output the final target torque. The execution layer consists of a motor controller and a drive motor assembly, used to receive the final target torque and perform electric braking; it also includes a mechanically redundant braking execution unit, which intervenes only when the electric braking force is insufficient under extreme operating conditions.

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