A mine trackless rubber-tyred vehicle road condition adaptive regenerative braking cooperative control method

Abstract

The present application relates to the technical field of mine vehicle braking control, in particular to a mine trackless rubber-tyred vehicle road condition adaptive regenerative braking cooperative control method, which comprises collecting vehicle state, battery, braking and underground road condition information, determining road condition type and selecting braking strategy; calculating road condition safety margin coefficient according to slope, slip rate, wheel speed difference, deceleration error, road surface disturbance and signal reliability; using the coefficient to correct target regenerative braking proportion and maximum available regenerative braking force, realizing double-layer constraint of strategy and execution; distributing regenerative braking and hydraulic or mechanical braking according to total braking force demand, and predicting front downhill recoverable energy for charging margin management. The present application is suitable for complex working conditions in coal mine underground, and can take into account braking safety, battery safety and energy recovery efficiency.

Description

Technical Field

[0001] This invention relates to the field of braking control technology for mining vehicles, specifically a method for adaptive regenerative braking coordinated control of trackless rubber-tired mining vehicles. Background Technology

[0002] Trackless rubber-tired vehicles for mining are essential equipment for transporting personnel, materials, and equipment underground in coal mines. They are characterized by low speed and heavy load, frequent starts and stops, numerous slopes, frequent braking, and limited space. Under conditions such as long downhill slopes, slippery mud, bumpy gravel transport, or heavy-load transport, the vehicle's braking system needs to provide stable and reliable braking force while reducing the thermal load and wear of the friction braking system.

[0003] The drive motor can operate in a generator state during braking, converting the vehicle's kinetic energy or potential energy from a slope into electrical energy to feed back into the power battery, thus improving the overall energy utilization rate of the vehicle. Therefore, the coordinated control of regenerative braking with hydraulic or mechanical braking is an important technical direction for improving the range and braking reliability of mining vehicles.

[0004] Existing technologies include control schemes that adjust the energy recovery intensity based on road condition identification results (e.g., CN113320394B) or provide the main braking torque from the motor supplemented by mechanical braking for downhill conditions (e.g., CN112549977B). However, these schemes are mainly geared towards paved roads or open-pit mines, and do not provide adaptive evaluation for unpaved road adhesion conditions such as water accumulation, mud, gravel, and bumps in coal mines. This makes it difficult to quantify the safe participation level of regenerative braking under low adhesion or disturbance conditions. Furthermore, these schemes primarily control based on current road conditions or slope, without incorporating multiple constraints such as battery SOC, temperature, SOH, and BMS allowable charging power to perform dual-layer correction of the regenerative braking participation level and maximum available regenerative braking force. They also fail to predict and schedule the recoverable energy and battery charging margin for the upcoming slope, resulting in insufficient continuity of total braking force when regenerative braking exits. Therefore, there is an urgent need to propose a road condition-adaptive regenerative braking collaborative control method for trackless rubber-tired mining vehicles. Summary of the Invention

[0005] The purpose of this invention is to provide a method for adaptive regenerative braking and coordinated control of trackless rubber-tired vehicles used in mining, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for adaptive regenerative braking coordinated control of trackless rubber-tired vehicles for mining, comprising the following steps: S1, collecting vehicle status information, battery status information, braking status information and underground road condition information of the trackless rubber-tired vehicle for mining.

[0007] S2. Determine the current underground road condition type and select the corresponding braking control strategy based on the current underground road condition type.

[0008] S3. Calculate the road condition safety margin coefficient based on the underground slope, wheel slip ratio, left and right wheel speed difference, vehicle longitudinal deceleration response error, road disturbance intensity, and sensor signal reliability.

[0009] S4. Determine the basic regenerative braking ratio according to the braking control strategy, and correct the basic regenerative braking ratio using the road condition safety margin coefficient to obtain the target regenerative braking ratio.

[0010] S5. Calculate the maximum available regenerative braking force based on the motor's power generation capacity, the battery's allowable charging capacity, the drive shaft's adhesion capacity, and vehicle stability constraints, and correct the maximum available regenerative braking force using the road condition safety margin coefficient.

[0011] S6. Determine the regenerative braking force command based on the driver's required total braking force, the target regenerative braking ratio, and the corrected maximum available regenerative braking force.

[0012] S7. Determine the hydraulic braking or wet mechanical braking compensation command based on the difference between the total braking force required by the driver and the regenerative braking force command.

[0013] S8 predicts the recoverable energy of the downhill section ahead based on underground positioning information, underground electronic tunnel map, vehicle equivalent mass, and information on the slope ahead, and determines the current charging margin of the power battery based on battery status information; when there is a continuous downhill section ahead of the vehicle, and the current charging margin of the power battery is less than the sum of recoverable energy and safety margin energy, it adjusts the degree of regenerative braking participation, target vehicle speed, or the participation ratio of hydraulic braking / wet mechanical braking.

[0014] As a further aspect of the present invention: the vehicle status information includes vehicle speed, angular velocity of each wheel, longitudinal acceleration, vertical acceleration, brake pedal travel, brake pedal rate of change, motor speed, motor torque, motor temperature, and vehicle equivalent mass; the battery status information includes battery SOC, SOH, maximum cell voltage, battery temperature, BMS allowable charging current, and BMS allowable charging power; the braking status information includes hydraulic braking pressure or wet mechanical braking control pressure; the underground road condition information includes at least one of underground positioning information, roadway number, slope information, slope length, road surface disturbance intensity, and roadway surface condition.

[0015] As a further aspect of the present invention: the current underground road condition types include high-adhesion gentle road conditions, normal slope road conditions, long downhill or heavy-load downhill road conditions, low-adhesion road conditions, bumpy road conditions, and unreliable signal road conditions; the corresponding braking control strategies include energy recovery priority strategy, safety and recovery balance strategy, long downhill energy management priority strategy, vehicle stability priority strategy, braking force smoothness priority strategy, and safety degradation priority strategy.

[0016] As a further aspect of the present invention: the road condition safety margin coefficient is obtained by fusing the slope safety factor, adhesion safety factor, road surface disturbance factor, and signal reliability factor, and the value range of the road condition safety margin coefficient is from 0 to 1, and is determined according to the following formula: ;in, For road condition safety margin coefficient, For the slope safety factor, For the adhesion safety factor, This is the road surface disturbance coefficient. This is the signal reliability coefficient.

[0017] The adhesion safety factor is determined based on at least one of wheel slip ratio, left and right wheel speed difference, and vehicle longitudinal deceleration response error. When the wheel slip ratio exceeds a set threshold, the left and right wheel speed difference increases abnormally, or the wheel-end braking force increases and the vehicle longitudinal deceleration response error increases accordingly, the adhesion safety factor is reduced in a manner positively correlated with the degree of exceeding the limit.

[0018] As a further aspect of the present invention: the target regenerative braking ratio is determined according to the following formula: ;in, For the target regenerative braking ratio, This represents the base regenerative braking ratio under the current braking control strategy. The current braking control strategy; the basic regenerative braking ratio According to the current braking control strategy Determined by a preset calibration table, piecewise function, or interpolation function.

[0019] As a further aspect of the present invention: the maximum available regenerative braking force is determined according to the following formula: ;in, This represents the upper limit of regenerative braking force corresponding to the generator's power generation capacity. The upper limit of regenerative braking force corresponding to the battery's allowable charging capacity. This represents the upper limit of regenerative braking force corresponding to the drive shaft's adhesion capability. The upper limit of regenerative braking force corresponding to vehicle stability constraints is determined based on battery SOC, maximum single-cell voltage, battery temperature, SOH, fault state, and BMS allowable charging power.

[0020] As a further aspect of the present invention: the regenerative braking force command is determined according to the following formula: .

[0021] The compensation command for hydraulic braking or wet mechanical braking is determined according to the following formula: ;in, The total braking force required by the driver. It is a hydraulic braking force or a wet mechanical braking force.

[0022] As a further aspect of the present invention: the recoverable energy of the downhill section ahead is determined based on underground positioning information, underground electronic tunnel map, vehicle equivalent mass, length of the slope ahead, and height difference of the downhill section ahead.

[0023] The continuous downhill section refers to a section along the current driving direction of the vehicle where the length of the non-downhill connecting section between adjacent downhill sections is no greater than the preset connecting length, and the total length of the merged downhill section is no less than the preset continuous downhill length, and the absolute value of the average downhill slope is no less than the preset slope threshold.

[0024] As a further aspect of the present invention: when it is predicted that the vehicle will enter a continuous downhill section at a preset forward sight distance or within a preset forward sight time, and the current charging margin of the power battery is less than the sum of the recoverable energy and the safety margin energy of the downhill section ahead, charging margin management control is triggered. Based on the proportional relationship between the current charging margin of the power battery and the sum of the recoverable energy and the safety margin energy of the downhill section ahead, the regenerative braking participation level under the current non-braking or light braking conditions is reduced in advance, the target vehicle speed is adjusted, or the participation ratio of hydraulic braking or wet mechanical braking is increased. The safety margin energy is calibrated based on the power battery capacity, SOC upper limit, BMS allowable charging power, and downhill duration.

[0025] As a further aspect of the present invention: when at least one of the following conditions is met, the vehicle controller enters a safety degradation mode: the battery SOC is higher than the first SOC threshold; the highest voltage of a single cell reaches a set percentage of the single cell overvoltage protection threshold set by the BMS; the battery temperature exceeds the set temperature range; the BMS prohibits charging; the motor controller malfunctions; the wheel slip ratio exceeds the slip ratio threshold and the duration exceeds the set time; the underground positioning signal is lost; the braking pressure response is abnormal; or an emergency braking condition occurs; in the safety degradation mode, the vehicle controller reduces the regenerative braking force to a safe value or zero, and compensates for the remaining braking force through hydraulic braking or wet mechanical braking to maintain continuous total braking force.

[0026] Compared with the prior art, the beneficial effects of the present invention are: (1) The present invention uses the underground road condition identification results to select the braking control strategy, rather than just to switch the degree of regenerative braking participation, which can better adapt to the complex underground working conditions such as low speed heavy load, frequent slopes, wet mud and gravel bumps of trackless rubber-tired vehicles.

[0027] (2) The present invention quantifies the safe participation level of regenerative braking under the current road conditions by using the road condition safety margin coefficient, and uses the coefficient to simultaneously correct the target regenerative braking ratio and the maximum available regenerative braking force, so that the regenerative braking is subject to the dual constraints of the strategy layer participation level and the execution layer safety boundary, avoiding excessive regenerative braking force under low adhesion or bumpy conditions, which may lead to wheel slippage, braking force fluctuation or braking force compensation lag.

[0028] (3) The present invention determines the maximum available regenerative braking force by taking into account the motor power generation capacity, battery charging capacity, drive shaft adhesion capacity and vehicle stability constraints, and can take into account braking safety, battery safety and energy recovery efficiency.

[0029] (4) When regenerative braking is limited or discontinued, the present invention compensates for the remaining braking force by hydraulic braking or wet mechanical braking to maintain the continuity of total braking force and reduce the risk of sudden changes in braking force.

[0030] (5) This invention combines underground positioning information and underground electronic tunnel map to predict the recoverable energy of the downhill section ahead, and adjusts the participation level of regenerative braking and the participation ratio of hydraulic braking or wet mechanical braking in advance according to the battery charging margin, which can reduce the risk of limited regenerative braking due to insufficient battery charging capacity during long downhill processes. Attached Figure Description

[0031] Figure 1 This is an overall flowchart of the adaptive regenerative braking and energy management coordinated control method based on road condition recognition of the present invention.

[0032] Figure 2 This is a schematic diagram of the information acquisition and controller connection of the present invention.

[0033] Figure 3 This is a logic diagram for selecting the downhole road condition recognition and braking control strategy in this invention.

[0034] Figure 4 This is a logic diagram for calculating the road condition safety margin coefficient in this invention.

[0035] Figure 5 This is a logic diagram for calculating the maximum available regenerative braking force and distributing braking force according to the present invention.

[0036] Figure 6 This is a logic diagram for predicting the forward slope and managing the charging margin of the power battery in this invention.

[0037] Figure 7 This is the logic diagram for safety degradation and hydraulic or wet mechanical braking compensation control under abnormal operating conditions in this invention. Detailed Implementation

[0038] The technical solution of this application will be further described in detail below with reference to specific embodiments.

[0039] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0040] like Figure 1 and Figure 2 As shown, this embodiment provides a collaborative control method for adaptive regenerative braking and energy management of trackless rubber-tired mining vehicles based on road condition recognition, applicable to trackless rubber-tired mining vehicles. The trackless rubber-tired mining vehicle includes a vehicle controller, a drive motor, a motor controller, a power battery, a BMS, a hydraulic braking system or a wet mechanical braking system, wheel speed sensors, longitudinal acceleration sensors, vertical acceleration sensors, brake pedal travel sensors, brake pressure sensors, and an underground positioning unit.

[0041] The method includes the following steps: S1, collecting vehicle status information, battery status information, braking status information, and underground road condition information of the trackless rubber-tired mining vehicle.

[0042] S2. Determine the current underground road condition type and select the corresponding braking control strategy based on the current underground road condition type.

[0043] S3. Calculate the road condition safety margin coefficient based on the underground slope, wheel slip ratio, left and right wheel speed difference, vehicle longitudinal deceleration response error, road disturbance intensity, and sensor signal reliability.

[0044] S4. Determine the basic regenerative braking ratio according to the braking control strategy, and correct the basic regenerative braking ratio using the road condition safety margin coefficient to obtain the target regenerative braking ratio.

[0045] S5. Calculate the maximum available regenerative braking force based on the motor's power generation capacity, the battery's allowable charging capacity, the drive shaft's adhesion capacity, and vehicle stability constraints, and correct the maximum available regenerative braking force using the road condition safety margin coefficient.

[0046] S6. Determine the regenerative braking force command based on the driver's required total braking force, the target regenerative braking ratio, and the corrected maximum available regenerative braking force.

[0047] S7. Determine the hydraulic braking or wet mechanical braking compensation command based on the difference between the total braking force required by the driver and the regenerative braking force command.

[0048] S8 predicts the recoverable energy of the downhill section ahead based on underground positioning information, underground electronic tunnel map, vehicle equivalent mass, and information on the slope ahead, and determines the current charging margin of the power battery based on battery status information; when there is a continuous downhill section ahead of the vehicle, and the current charging margin of the power battery is less than the sum of recoverable energy and safety margin energy, it adjusts the degree of regenerative braking participation, target vehicle speed, or the participation ratio of hydraulic braking / wet mechanical braking.

[0049] The following combination Figures 1 to 7 Each step is explained in detail.

[0050] like Figure 2 As shown, the vehicle controller is connected to the motor controller, BMS, hydraulic brake control unit or wet mechanical brake control unit and underground positioning unit to collect vehicle status information, battery status information, braking status information and underground road condition information, and to determine regenerative braking force command and hydraulic braking or wet mechanical braking compensation command based on the collected information.

[0051] During vehicle operation, the vehicle controller collects real-time data on vehicle speed, wheel angular velocity, longitudinal acceleration, vertical acceleration, brake pedal travel, brake pedal change rate, motor speed, motor torque, motor temperature, and vehicle equivalent mass. Simultaneously, it collects battery SOC, SOH, maximum cell voltage, battery temperature, BMS allowable charging current, and BMS allowable charging power. It also collects hydraulic braking pressure or wet mechanical braking control pressure, underground positioning information, tunnel number, slope information, slope length, road surface disturbance intensity, and tunnel surface condition.

[0052] The tunnel number, slope information, and slope length can be obtained by matching the underground positioning information with the underground electronic tunnel map. The road surface disturbance intensity and tunnel surface condition can be determined by vehicle operation response information or environmental perception information.

[0053] like Figure 3 As shown, the vehicle controller determines the current underground road condition type based on the underground slope, slope length, wheel slip ratio, left and right wheel speed difference, vehicle longitudinal deceleration response error, vertical acceleration, wheel speed fluctuation intensity, and the reliability of the underground positioning signal.

[0054] The current underground road conditions include high-adhesion gentle road conditions, normal slope road conditions, long downhill or heavy-load downhill road conditions, low-adhesion road conditions, bumpy road conditions, and unreliable signal road conditions.

[0055] After determining the current underground road conditions, the vehicle controller selects the corresponding braking control strategy. For high-adhesion, smooth road conditions, an energy recovery priority strategy is adopted; for normal slope road conditions, a safety and recovery balance strategy is adopted; for long downhill or heavily loaded downhill road conditions, a long downhill energy management priority strategy is adopted; for low-adhesion road conditions, a vehicle stability priority strategy is adopted; for bumpy road conditions, a braking force smoothness priority strategy is adopted; and for road conditions with unreliable signals, a safety degradation priority strategy is adopted.

[0056] like Figure 4 As shown, to avoid directly adjusting the regenerative braking participation level solely based on road condition type, this embodiment further calculates a road condition safety margin coefficient. This road condition safety margin coefficient characterizes the safe participation level of regenerative braking under the current road condition, and its value ranges from 0 to 1. A larger value indicates a higher degree of regenerative braking participation; a smaller value indicates that regenerative braking should be reduced or discontinued.

[0057] The road condition safety margin coefficient is obtained by combining the slope safety factor, adhesion safety factor, road surface disturbance factor, and signal reliability factor. ;in, For road condition safety margin coefficient, For the slope safety factor, For the adhesion safety factor, This is the road surface disturbance coefficient. This is the signal reliability coefficient.

[0058] In this embodiment, the slope safety factor, adhesion safety factor, road surface disturbance factor, and signal reliability factor can all be calculated using a normalized limiting function. The normalized limiting function satisfies: .

[0059] like Figure 4 As shown, the slope safety factor It can be determined based on the slope G, the ramp length L, and the vehicle's equivalent mass m: ; ;in, This is the lower limit of the slope safety factor. This is the downhill condition indicator. It is set to 1 when the vehicle is downhill or under heavy load braking conditions, and 0 otherwise. , The slope threshold, , This is the threshold for ramp length. , This refers to the vehicle's equivalent mass threshold. This threshold can be pre-calibrated based on the type of trackless rubber-tired mining vehicle, rated load, and underground roadway slope conditions. When there is a risk of adhesion, insufficient battery charging margin, or continuous braking risk under long downhill or heavy-load downhill conditions, the vehicle controller reduces the corresponding safety factor or adjusts the braking control strategy.

[0060] Adhesion safety factor Based on wheel slip ratio Speed ​​difference between left and right wheels and vehicle longitudinal deceleration response error Sure: ; ;in, This is the lower limit of the adhesion safety factor. , The slip ratio threshold, , The threshold for the speed difference between the left and right wheels. , This is the threshold for the longitudinal deceleration response error of the vehicle.

[0061] When the wheel slip ratio exceeds a set threshold, the difference between the left and right wheel speeds increases significantly, or the wheel-end braking force increases and the vehicle's longitudinal deceleration response error increases accordingly, the adhesion safety factor is reduced in a manner positively correlated with the degree of exceedance. The reduction method includes at least one of continuous monotonous reduction, piecewise linear reduction, or graded reduction.

[0062] Road surface disturbance coefficient Based on the root mean square value of vertical acceleration and wheel speed fluctuation intensity Sure: ; ;in, This is the lower limit of the road surface disturbance coefficient. , The vertical acceleration threshold, , The wheel speed fluctuation intensity threshold. This is the road surface disturbance coefficient when a vehicle travels over gravel, potholes, or bumpy road sections, causing an increase in vertical acceleration or wheel speed fluctuation. reduce.

[0063] Signal reliability coefficient Based on the reliability of the downhole positioning signal Wheel speed signal reliability BMS signal reliability And the reliability of braking pressure signals Sure: ;in, , , and The values ​​range from 0 to 1. When any critical signal fails or its reliability falls below a preset threshold, the vehicle controller enters a safety degradation priority strategy and reduces or cuts off the participation of regenerative braking.

[0064] The aforementioned threshold values ​​for slope, ramp length, vehicle equivalent mass, slip ratio, left and right wheel speed difference, vehicle longitudinal deceleration response error, vertical acceleration, and wheel speed fluctuation intensity can be calibrated based on the type of trackless rubber-tired mining vehicle, rated load, tire-to-underground roadway adhesion test data, braking test data, underground roadway ramp parameters, and sensor reliability statistics.

[0065] As a preferred method, slope threshold A slope of 3° to 5° can be used as the slope threshold. An angle of 6° to 10° can be used; threshold for ramp length. A slope length threshold of 50 m to 100 m can be used. The range can be from 150 m to 500 m; vehicle equivalent mass threshold. The vehicle's equivalent mass threshold can be 0.6 to 0.8 times its rated mass. It can be taken as 1.0 to 1.2 times the vehicle's rated weight.

[0066] As a preferred method, the slip ratio threshold The slip ratio threshold can be between 0.08 and 0.12. The threshold values ​​can be 0.15 to 0.25; the left and right wheel speed difference thresholds can be expressed as the ratio of the left and right wheel speed difference to the average wheel speed, where the first wheel speed difference threshold can be 0.03 to 0.05 and the second wheel speed difference threshold can be 0.08 to 0.15; the vehicle longitudinal deceleration response error thresholds can be expressed as the relative error between the expected deceleration and the actual deceleration, where the first deceleration response error threshold can be 0.10 to 0.20 and the second deceleration response error threshold can be 0.30 to 0.50.

[0067] As a preferred method, the root mean square threshold of vertical acceleration The value can be taken as 0.15g to 0.30g, the root mean square threshold of vertical acceleration. The dosage can be 0.35g to 0.60g; wheel speed fluctuation intensity threshold. The threshold value can be between 0.05 and 0.10, representing the wheel speed fluctuation intensity. The value can be between 0.12 and 0.25. The above numerical range is only used to illustrate the calibration method of the present invention and does not constitute a limitation on the scope of protection of the present invention.

[0068] like Figure 4 and Figure 5As shown, after determining the braking control strategy and road condition safety margin coefficient, the vehicle controller determines the basic regenerative braking ratio based on the current braking control strategy, and then corrects the basic regenerative braking ratio using the road condition safety margin coefficient. ;in, For the target regenerative braking ratio, This represents the base regenerative braking ratio under the current braking control strategy. This is the current braking control strategy.

[0069] Furthermore, the basic regenerative braking ratio According to the current braking control strategy Determined by a preset calibration table, piecewise function, or interpolation function.

[0070] As a preferred method, when When the energy recovery priority strategy is adopted, Take the first basic ratio , The value range is from 0.65 to 0.90; when When a safety and recycling balance strategy is adopted, Take the second basic ratio , The value range is from 0.45 to 0.70; when When prioritizing energy management strategies for long downhill slopes, Take the third basic ratio , The value range is from 0.30 to 0.65; when When prioritizing vehicle stability, Take the fourth basic ratio , The value range is from 0.15 to 0.40; when When prioritizing braking smoothness, Take the fifth basic ratio , The value range is from 0.20 to 0.45; when When prioritizing security downgrade strategies, Take the sixth basic ratio , The value range is from 0 to 0.20.

[0071] Under the long downhill energy management priority strategy, when the charging margin management trigger condition is met, the vehicle controller reduces the third basic ratio. Or further reduce the target regenerative braking ratio In addition, the participation rate of hydraulic braking or wet mechanical braking should be increased to avoid a sudden decrease or disengagement of regenerative braking due to limited battery charging capacity when the vehicle enters a long downhill section.

[0072] Furthermore, the target regenerative braking ratio is subjected to amplitude limiting and rate of change constraint processing to ensure that the target regenerative braking ratio changes smoothly within adjacent control cycles.

[0073] like Figure 5 As shown, the vehicle controller further calculates the maximum available regenerative braking force. This maximum available regenerative braking force is jointly limited by the motor's power generation capacity, the battery's allowable charging capacity, the drive shaft's adhesion capacity, and vehicle stability constraints, and is corrected by a road condition safety margin coefficient. ;in, This represents the upper limit of regenerative braking force corresponding to the generator's power generation capacity. The upper limit of regenerative braking force corresponding to the battery's allowable charging capacity. This represents the upper limit of regenerative braking force corresponding to the drive shaft's adhesion capability. The upper limit of regenerative braking force corresponding to vehicle stability constraints is determined based on battery SOC, maximum single-cell voltage, battery temperature, SOH, fault state, and BMS allowable charging power.

[0074] Specifically, the battery's allowable charging power can be expressed as: ;in, The allowable charging power is determined based on the battery's state of charge (SOC). The allowable charging power is determined based on battery temperature. The allowable charging power is determined based on the highest voltage of the individual cell. The allowable charging power is determined based on the battery's state of health. These are the limits under fault conditions. The battery's allowed charging power is defined by the BMS. The vehicle controller calculates the upper limit of regenerative braking force under battery constraints based on the allowed charging power of the battery.

[0075] When the driver presses the brake pedal, the vehicle controller calculates the total braking force required by the driver based on the brake pedal travel, brake pedal change rate, vehicle speed, and vehicle equivalent mass. The regenerative braking force command is determined according to the following formula: .

[0076] The compensation command for hydraulic braking or wet mechanical braking is determined according to the following formula: .

[0077] In the above control process, the road condition safety margin coefficient Acting on the target regenerative braking ratio respectively and maximum available regenerative braking force This creates a two-tiered constraint at both the braking allocation strategy level and the execution capability boundary level. Among these, the target regenerative braking ratio... This is used to characterize the target proportion of current braking demand borne by regenerative braking, and belongs to the strategy-level adjustment of the regenerative braking participation level; maximum available regenerative braking force. This is used to characterize the upper limit of regenerative braking that can be safely output under constraints of motor power generation capacity, battery charging capacity, drive shaft adhesion, and vehicle stability; it belongs to the boundary layer correction of regenerative braking execution capability. By making... Simultaneously correct and When the underground road conditions are low adhesion, bumpy, long downhill, heavy-load downhill, or reduced signal reliability, on the one hand, the target proportion of regenerative braking in the total braking force is reduced, and on the other hand, the safe output limit of regenerative braking force is reduced. This avoids insufficient safety boundary due to only adjusting the regenerative braking ratio, and also avoids braking force command saturation, compensation lag, or sudden braking force changes due to only limiting the maximum available regenerative braking force.

[0078] In this way, when the road safety margin decreases, the battery's charging capacity decreases, or the motor's power generation capacity is insufficient, the regenerative braking force decreases accordingly. The hydraulic braking or wet mechanical braking compensates for the remaining braking force in real time, so that the sum of regenerative braking and hydraulic braking or wet mechanical braking continuously meets the driver's braking needs.

[0079] like Figure 6 As shown, this embodiment also includes forward slope prediction and charging margin management. The vehicle controller predicts the recoverable energy of the forward downhill section based on the underground positioning information, the underground electronic tunnel map, the vehicle's equivalent mass, and the forward slope information.

[0080] The recoverable energy of the downhill section ahead is determined based on underground positioning information, underground electronic tunnel map, vehicle equivalent mass, length of the slope ahead, and the height difference of the downhill section. The recoverable energy is estimated using the following formula: ;in, Energy can be recovered on the downhill section ahead. To improve overall recycling efficiency, The equivalent mass of the vehicle. It is the acceleration due to gravity. This represents the elevation difference of the downhill section ahead.

[0081] The vehicle controller determines the current charging margin of the power battery based on the battery SOC, maximum cell voltage, battery temperature, SOH, and BMS allowable charging power. As a preferred approach, the current charging margin of the power battery... The rechargeable energy margin can be determined jointly based on SOC, the highest voltage of a single cell, the battery temperature, SOH, and the BMS-permitted charging power. ;in, The rechargeable energy margin is determined based on the battery's state of charge (SOC). This is the rechargeable energy margin determined based on the highest voltage of the individual cell. This refers to the rechargeable energy margin determined based on battery temperature. This refers to the rechargeable energy margin determined based on the battery's state of health. This is the rechargeable energy margin determined based on the BMS's allowed charging power.

[0082] like Figure 6 As shown, when the charging margin management trigger condition is met, it is determined that there is a risk of insufficient battery charging capacity after the vehicle enters a long downhill section. Under such circumstances, the vehicle controller reduces the regenerative braking participation level in the current non-braking or light braking conditions in advance, adjusts the vehicle's target speed, or increases the participation ratio of hydraulic braking or wet mechanical braking to avoid a sudden decrease or disengagement of regenerative braking due to limited battery charging capacity after the vehicle enters a long downhill section.

[0083] In this embodiment, "advance" refers to the vehicle controller operating at a preset forward sight distance before the vehicle enters the continuous downhill section ahead. Or preset forward viewing time The judgment and control adjustment are completed internally. Among them, A range of 50m to 200m can be taken. The timeframe can be 5s to 20s. The continuous downhill section is determined along the vehicle's current direction of travel: when the length of the non-downhill connecting section between adjacent downhill sections is not greater than a preset connecting length, the adjacent downhill sections are merged; when the total length of the merged downhill section is not less than a preset continuous downhill length, and the absolute value of the average downhill gradient is not less than a preset gradient threshold, it is determined to be a continuous downhill section. As a preferred method, the preset connecting length can be 10m to 20m, the preset continuous downhill length can be 100m to 300m, and the preset gradient threshold can be 3° to 5°. When the underground positioning information and the underground electronic tunnel map determine that the vehicle will enter the continuous downhill section at the preset forward sight distance or preset forward sight time, and the current charging margin of the power battery... Less than the energy recoverable on the downhill section ahead With safety margin energy When the sum is equal, the charging margin management control is triggered: ;in, To reserve a safety margin of energy, calibration can be performed based on the power battery capacity, SOC limit, BMS allowable charging power, and downhill duration.

[0084] Furthermore, the vehicle controller can determine the adjustment amount based on the degree of insufficient charging margin. As a preferred approach, a charging margin ratio is defined. for: .

[0085] when When the value is less than 1, the vehicle controller follows the procedure. Reduce the base regenerative braking ratio or target regenerative braking ratio under the long downhill energy management priority strategy. For example, the adjusted base regenerative braking ratio can be determined as follows: Alternatively, the adjusted target regenerative braking ratio can be determined as follows: .

[0086] Simultaneously, the vehicle controller increases the engagement ratio of hydraulic braking or wet mechanical braking based on the braking force gap caused by the reduced regenerative braking participation; when When the speed is below a preset threshold, the vehicle's target speed can be reduced to decrease the continuous braking demand after the vehicle enters a continuous downhill section.

[0087] As a specific embodiment, the vehicle is in a low-adhesion, heavy-load downhill braking condition with a current slope of 6°, an equivalent vehicle mass of 12,000 kg, a vehicle speed of 10 km / h, and a power battery SOC of 85%. The vehicle controller calculates the slope safety factor based on wheel slip ratio, left and right wheel speed difference, vertical acceleration, and the reliability of the underground positioning signal. Adhesion safety factor Road surface disturbance coefficient Signal reliability coefficient The road condition safety margin coefficient is then: .

[0088] When the current braking control strategy is a balance between safety and regeneration, the basic regenerative braking ratio is... If we take 0.60, then the target regenerative braking ratio is: .

[0089] Under this condition, the vehicle controller reduces the regenerative braking target participation rate to 24% to avoid excessive regenerative braking force under conditions of low adhesion or slippage risk. If the driver requires total braking force... If the value is 30 kN, then the regenerative braking force requirement calculated according to the target regenerative braking ratio is: .

[0090] Meanwhile, if the upper limits of regenerative braking force corresponding to the motor's power generation capacity, battery's allowable charging capacity, drive shaft adhesion capacity, and vehicle stability constraints are 30 kN, 18 kN, 22 kN, and 25 kN, respectively, then the maximum available regenerative braking force is: .

[0091] Therefore, the regenerative braking force command is: .

[0092] The compensation command for hydraulic braking or wet mechanical braking is as follows: .

[0093] Therefore, under low-adhesion heavy-load downhill conditions, the present invention can simultaneously limit the target regenerative braking ratio and the maximum available regenerative braking force through the road condition safety margin coefficient, and compensate for the remaining braking force through hydraulic braking or wet mechanical braking, thereby maintaining the continuity of total braking force.

[0094] As another specific embodiment, the vehicle identifies a continuous downhill section ahead based on underground positioning information and an underground electronic tunnel map. The downhill elevation difference ahead is 25 m, the vehicle's equivalent mass is 12,000 kg, and the energy recovery efficiency coefficient is... Taking 0.60, the recoverable energy of the downhill section ahead is: ; .

[0095] If the battery's SOC is 92% at this time, and the highest voltage of a single cell is close to the protection threshold, the BMS allows a reduction in charging power. The vehicle controller calculates the current charging margin of the battery as follows: ;because And safety margin energy Greater than zero, therefore satisfies This means that the charging margin management trigger conditions are met.

[0096] Therefore, it was determined that there was a risk of insufficient battery charging margin after the vehicle entered the continuous downhill section ahead. At this time, the vehicle controller reduced the base regenerative braking ratio under the long downhill energy management priority strategy in advance, for example, by setting the third base ratio. The safety margin coefficient for the current road conditions is reduced from 0.50 to 0.30. If the value is 0.70, then the target regenerative braking ratio is determined by: .

[0097] Adjusted to: .

[0098] At the same time, the vehicle controller increases the participation ratio of hydraulic braking or wet mechanical braking to compensate for the braking force gap corresponding to the reduced participation of regenerative braking, and avoids the sudden decrease or withdrawal of regenerative braking due to insufficient battery charging capacity after the vehicle enters a long downhill.

[0099] The above values ​​are only used to illustrate the control logic of the present invention and do not constitute a limitation on the scope of protection of the present invention; the relevant thresholds, ratios and coefficients can be calibrated according to the vehicle model, rated load, motor capacity, battery capacity and underground roadway conditions.

[0100] like Figure 7As shown, when the battery SOC is detected to be higher than the set threshold, the highest voltage of a single cell is close to the protection threshold, the battery temperature is abnormal, the BMS prohibits charging, the motor controller malfunctions, the wheel slip ratio exceeds the limit, the underground positioning signal is lost, the braking pressure response is abnormal, or an emergency braking condition is encountered, the vehicle controller enters the safety degradation mode, reduces the regenerative braking force to a safe value or zero, and compensates for the remaining braking force through hydraulic braking or wet mechanical braking.

[0101] Further, in this embodiment, the battery SOC exceeding the set threshold means that the battery SOC is greater than or equal to 85% to 95%, preferably 90%; the single-cell maximum voltage approaching the protection threshold means that the single-cell maximum voltage reaches 95% to 99% of the single-cell overvoltage protection threshold set by the BMS; the battery temperature abnormality means that the battery temperature is below 0°C to 5°C, or above 45°C to 55°C; the wheel slip rate exceeding the limit means that the wheel slip rate is above 0.15 to 0.25 for 200ms to 500ms continuously, preferably above 0.20. The above thresholds can be calibrated according to the vehicle model, power battery chemical system, rated load, BMS charging limit curve, tire and underground roadway surface adhesion test data, braking test data, and sensor sampling period.

[0102] The adaptive regenerative braking collaborative control method for trackless rubber-tired vehicles in mines selects braking control strategies by identifying underground road conditions, quantifies the degree of regenerative braking safety participation by using a road condition safety margin coefficient, and uses this coefficient to simultaneously correct the target regenerative braking ratio and the maximum available regenerative braking force. At the same time, it combines the current battery charging margin and the prediction of the slope ahead to manage the charging margin, so that the trackless rubber-tired vehicles in mines can take into account braking safety, battery safety and energy recovery efficiency under complex underground road conditions.

[0103] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these should also be considered within the scope of protection of the present invention. These will not affect the effectiveness of the implementation of the present invention or the practicality of the patent.

Claims

1. A method for adaptive regenerative braking coordinated control of trackless rubber-tired vehicles used in mining, characterized in that, Includes the following steps: S1. Collect vehicle status information, battery status information, braking status information, and underground road condition information of the trackless rubber-tired mining vehicle; S2. Determine the current underground road condition type and select the corresponding braking control strategy based on the current underground road condition type; S3. Calculate the road condition safety margin coefficient based on the underground slope, wheel slip ratio, left and right wheel speed difference, vehicle longitudinal deceleration response error, road disturbance intensity and sensor signal reliability. S4. Determine the basic regenerative braking ratio according to the braking control strategy, and correct the basic regenerative braking ratio using the road condition safety margin coefficient to obtain the target regenerative braking ratio. S5. Calculate the maximum available regenerative braking force based on the motor's power generation capacity, the battery's allowable charging capacity, the drive shaft's adhesion capacity, and vehicle stability constraints, and correct the maximum available regenerative braking force using the road condition safety margin coefficient. S6. Determine the regenerative braking force command based on the driver's required total braking force, the target regenerative braking ratio, and the corrected maximum available regenerative braking force; S7. Determine the hydraulic braking or wet mechanical braking compensation command based on the difference between the total braking force required by the driver and the regenerative braking force command. S8. Based on the underground positioning information, underground electronic tunnel map, vehicle equivalent mass and the information of the slope ahead, predict the recoverable energy of the downhill section ahead, and determine the current charging margin of the power battery based on the battery status information. When there is a continuous downhill section in front of the vehicle, and the current charging margin of the power battery is less than the sum of the recoverable energy and the safety margin energy, adjust the degree of regenerative braking participation, the target vehicle speed, or the participation ratio of hydraulic braking / wet mechanical braking. The recoverable energy of the downhill section ahead is determined based on underground positioning information, underground electronic tunnel map, vehicle equivalent mass, length of the slope ahead, and height difference of the downhill section ahead. The continuous downhill section refers to a section along the current driving direction of the vehicle, in which the length of the non-downhill connecting section between adjacent downhill sections is no greater than the preset connecting length, and the total length of the merged downhill section is no less than the preset continuous downhill length, and the absolute value of the average downhill slope is no less than the preset slope threshold. When it is predicted that the vehicle will enter a continuous downhill section at a preset forward sight distance or within a preset forward sight time, and the current charging margin of the power battery is less than the sum of the recoverable energy and the safety margin energy of the downhill section ahead, the charging margin management control is triggered. Based on the ratio between the current charging margin of the power battery and the sum of the recoverable energy and the safety margin energy of the downhill section ahead, the regenerative braking participation level under the current non-braking or light braking conditions is reduced in advance, the target vehicle speed is adjusted, or the participation ratio of hydraulic braking or wet mechanical braking is increased. The safety margin energy is calibrated based on the power battery capacity, SOC limit, BMS allowable charging power, and downhill duration.

2. The adaptive regenerative braking coordinated control method for trackless rubber-tired mining vehicles according to claim 1, characterized in that, The vehicle status information includes vehicle speed, angular velocity of each wheel, longitudinal acceleration, vertical acceleration, brake pedal travel, brake pedal rate of change, motor speed, motor torque, motor temperature, and vehicle equivalent mass; the battery status information includes battery SOC, SOH, maximum single-cell voltage, battery temperature, BMS allowable charging current, and BMS allowable charging power; the braking status information includes hydraulic braking pressure or wet mechanical braking control pressure; the underground road condition information includes at least one of the following: underground positioning information, roadway number, slope information, slope length, road surface disturbance intensity, and roadway surface condition.

3. The adaptive regenerative braking coordinated control method for trackless rubber-tired mining vehicles according to claim 1, characterized in that, The current underground road conditions include high-adhesion gentle road conditions, normal slope road conditions, long downhill or heavy-load downhill road conditions, low-adhesion road conditions, bumpy road conditions, and unreliable signal road conditions; the corresponding braking control strategies include energy recovery priority strategy, safety and recovery balance strategy, long downhill energy management priority strategy, vehicle stability priority strategy, braking force smoothness priority strategy, and safety degradation priority strategy.

4. The adaptive regenerative braking coordinated control method for trackless rubber-tired mining vehicles according to claim 1, characterized in that, The road condition safety margin coefficient is obtained by fusing the slope safety factor, adhesion safety factor, road surface disturbance factor, and signal reliability factor, and the value of the road condition safety margin coefficient ranges from 0 to 1, and is determined according to the following formula: ； in, For road condition safety margin coefficient, For the slope safety factor, For the adhesion safety factor, This is the road surface disturbance coefficient. The signal reliability coefficient; The adhesion safety factor is determined based on at least one of wheel slip ratio, left and right wheel speed difference, and vehicle longitudinal deceleration response error. When the wheel slip ratio exceeds a set threshold, the left and right wheel speed difference increases abnormally, or the wheel-end braking force increases and the vehicle longitudinal deceleration response error increases accordingly, the adhesion safety factor is reduced in a manner positively correlated with the degree of exceeding the limit.

5. The adaptive regenerative braking coordinated control method for trackless rubber-tired mining vehicles according to claim 1, characterized in that, The target regenerative braking ratio is determined according to the following formula: ； in, For the target regenerative braking ratio, This represents the base regenerative braking ratio under the current braking control strategy. The current braking control strategy; the basic regenerative braking ratio According to the current braking control strategy Determined by a preset calibration table, piecewise function, or interpolation function.

6. The adaptive regenerative braking coordinated control method for trackless rubber-tired mining vehicles according to claim 1, characterized in that, The maximum available regenerative braking force is determined according to the following formula: ； in, This represents the upper limit of regenerative braking force corresponding to the generator's power generation capacity. The upper limit of regenerative braking force corresponding to the battery's allowable charging capacity. This represents the upper limit of regenerative braking force corresponding to the drive shaft's adhesion capability. The upper limit of regenerative braking force corresponding to vehicle stability constraints is determined based on battery SOC, maximum single-cell voltage, battery temperature, SOH, fault state, and BMS allowable charging power.

7. The adaptive regenerative braking coordinated control method for trackless rubber-tired mining vehicles according to claim 1, characterized in that, The regenerative braking force command is determined according to the following formula: ； The compensation command for hydraulic braking or wet mechanical braking is determined according to the following formula: ； in, The total braking force required by the driver. It is a hydraulic braking force or a wet mechanical braking force.

8. The adaptive regenerative braking coordinated control method for trackless rubber-tired mining vehicles according to claim 1, characterized in that, The vehicle controller enters a safety degradation mode when at least one of the following conditions is met: the battery SOC is higher than the first SOC threshold. The highest voltage of a single cell reaches the set percentage of the single cell overvoltage protection threshold set by the BMS; the battery temperature exceeds the set temperature range; the BMS prohibits charging; the motor controller malfunctions; the wheel slip rate exceeds the slip rate threshold and the duration exceeds the set time. Downhole positioning signal lost; abnormal braking pressure response; Or emergency braking conditions; In the safety degradation mode, the vehicle controller reduces the regenerative braking force to a safe value or zero, and compensates for the remaining braking force through hydraulic braking or wet mechanical braking to maintain continuous total braking force.

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