Balancing control method and device for water spraying vehicle and electric water spraying vehicle

Abstract

This disclosure relates to a method, control device, and electric sprinkler vehicle for balance control. The method includes: real-time acquisition of the sprinkler vehicle's speed, motor output torque, driver-required torque, and load value; acquisition of a reference torque for flat roads based on the speed and load value; acquisition of a torque deviation value based on the difference between the motor output torque and the reference torque; determination of the sprinkler vehicle's operating condition based on the torque deviation value, motor output torque, and driver-required torque; acquisition of the sprinkler vehicle's speed change rate when the operating condition is uphill or downhill; if the absolute value of the speed change rate is not less than a first risk threshold, the sprinkler vehicle is determined to be in a swaying condition, and sprinkler vehicle spraying status control and overall torque control are performed. This disclosure can improve the driving stability of sprinkler vehicles.

Description

Technical Field

[0001] This disclosure relates to the field of new energy engineering machinery technology, and in particular to a method, control device and electric sprinkler vehicle for balance control of sprinkler vehicles. Background Technology

[0002] Currently, the mining transportation sector is accelerating its transformation towards green and clean technologies, and new energy mining equipment has entered a period of rapid development characterized by large-scale promotion and technological iteration. Against this backdrop, ultra-large tonnage pure electric sprinkler trucks, as key equipment for dust suppression and environmental governance in mines, still face numerous challenges in overcoming core technological hurdles, among which the contradiction between vehicle dynamic stability and the special operational characteristics of pure electric sprinkler trucks is particularly prominent.

[0003] Mining operations are characterized by numerous slopes and harsh road conditions. The liquid in the extra-large water tank is prone to violent shaking during driving and braking, resulting in significant liquid-solid coupling dynamics. This can cause vehicle pitching, rolling, and longitudinal impact, directly affecting the overall vehicle driving safety. Summary of the Invention

[0004] The embodiments of this disclosure provide a water sprinkler vehicle balance control method, control device, and electric water sprinkler vehicle, which can improve the driving stability of the water sprinkler vehicle.

[0005] According to a first aspect of this disclosure, a method for controlling the balance of a water sprinkler vehicle is proposed, comprising:

[0006] Real-time acquisition of the vehicle speed, motor output torque, driver-required torque, and load value of the sprinkler truck;

[0007] The reference torque for flat roads is obtained based on vehicle speed and load values, and the torque deviation value is obtained based on the difference between the motor output torque and the reference torque for flat roads.

[0008] The driving conditions of the sprinkler truck are determined based on the torque deviation value, the motor output torque, and the torque required by the driver.

[0009] When the water sprinkler truck is in an uphill or downhill driving condition, the speed change rate of the water sprinkler truck is obtained. If the absolute value of the speed change rate is not less than the first risk threshold, the water sprinkler truck is determined to be in an easily swaying condition, and the water sprinkler truck is controlled in terms of water spraying status and overall vehicle torque.

[0010] Among them, the water spraying status control includes at least one of water spraying power control and water spraying direction control, and the vehicle torque control includes at least one of limiting the torque change rate of the motor output torque, applying pitch compensation torque, and distributing torque to the left and right wheels.

[0011] In some embodiments, sprinkler power control includes:

[0012] If the absolute value of the rate of change of vehicle speed is less than the first risk threshold, the water sprinkler truck will spray water at the first power.

[0013] If the absolute value of the rate of change of vehicle speed is not less than the first risk threshold and not greater than the second risk threshold, the water sprinkler vehicle shall spray water at the second power.

[0014] If the absolute value of the rate of change of vehicle speed is greater than the second risk threshold, the water sprinkler truck will spray water at the third power.

[0015] The first risk threshold is less than the second risk threshold, the first power is less than the second power, and the second power is less than the third power.

[0016] In some embodiments, spray direction control includes:

[0017] When the water sprinkler truck is working uphill, the main spraying direction of the water sprinkler truck should be towards the rear.

[0018] When the water sprinkler truck is going downhill, the main spraying direction of the water sprinkler truck should be forward.

[0019] In some embodiments, determining the driving condition of the sprinkler vehicle based on the torque deviation value, the motor output torque, and the driver's required torque includes:

[0020] If the driver's required torque is positive and the torque deviation is greater than the uphill threshold, the sprinkler truck is determined to be in uphill condition.

[0021] When the driver's required torque is positive and the torque deviation is less than the first downhill threshold, the sprinkler truck is determined to be in the first downhill condition. The downhill slope percentage of the first downhill condition is not greater than the preset slope percentage.

[0022] When the driver's required torque is negative, the motor output torque is negative, and the absolute value of the sum of the motor output torque and the flat road reference torque is greater than the second downhill threshold, the sprinkler vehicle is determined to be in the second downhill condition. The downhill slope percentage of the second downhill condition is greater than the preset slope percentage. The downhill condition includes the first downhill condition and the second downhill condition.

[0023] In some embodiments, limiting the rate of change of the motor output torque includes:

[0024] The stringency of the limitation on the rate of change of motor output torque is directly proportional to the magnitude of the absolute value of the torque deviation; and / or

[0025] When the water sprinkler truck is working uphill, the negative torque change rate of the motor output torque is limited; when the water sprinkler truck is working downhill, the positive torque change rate of the motor output torque is limited.

[0026] In some embodiments, limiting the rate of change of the motor output torque includes:

[0027] When the water sprinkler truck is in an uphill or downhill condition, the water sprinkler truck is subjected to a typical slope acceleration / braking test to obtain the torque change rate threshold that keeps the vehicle in balance.

[0028] An interpolation algorithm is used to calculate the torque change rate threshold corresponding to atypical slopes based on the fitting calculation results of the torque change rate threshold of adjacent slopes.

[0029] When the water sprinkler truck is operating uphill or downhill, the torque change rate of the water sprinkler truck shall not exceed the torque change rate threshold.

[0030] In some embodiments, applying pitch compensation torque includes:

[0031] The pitching moment is calculated based on the vehicle speed change rate, the total mass of the water sprinkler vehicle, and the equivalent cylinder rod arm. The total mass of the water sprinkler vehicle is equal to the sum of the vehicle body mass and the load value.

[0032] The control motor outputs a pitch compensation torque that is equal in magnitude but opposite in direction to the pitch torque.

[0033] In some embodiments, distributing torque between the left and right wheels includes:

[0034] Real-time acquisition of steering wheel angle and lateral acceleration of sprinkler trucks;

[0035] The steering state of the sprinkler vehicle is determined based on the steering wheel angle and lateral acceleration. The torque of the left and right wheels is distributed according to the steering state. The steering state includes at least one of the following: straight driving condition, lateral disturbance condition, and active steering condition.

[0036] In some embodiments, determining the steering state based on the steering wheel angle and lateral acceleration, and distributing torque to the left and right wheels based on the steering state includes:

[0037] When the steering wheel angle is less than the steering threshold and the lateral acceleration is less than the lateral acceleration threshold, the sprinkler vehicle is determined to be in a straight-line driving condition, so that the torque of the left and right wheels is equal and both are the side wheel reference torque. The side wheel reference torque is half of the sum of the torque required by the driver and the pitch compensation torque.

[0038] When the steering wheel angle is less than the steering threshold and the lateral acceleration is not less than the lateral acceleration threshold, the sprinkler vehicle is determined to be in a lateral disturbance condition. The lateral compensation torque is calculated based on the lateral acceleration and load value. The differential torque distribution is performed on the left and right wheels based on the side wheel reference torque and the lateral compensation torque.

[0039] When the steering wheel angle is greater than the steering threshold, the sprinkler vehicle is determined to be in active steering mode. The steering compensation torque is calculated based on the steering wheel angle and vehicle speed, and differential torque is distributed to the left and right wheels based on the side wheel reference torque and the steering compensation torque.

[0040] In some embodiments, before obtaining the reference torque for flat road based on vehicle speed and load value, the method further includes establishing a mapping relationship between the reference torque for flat road driving of the sprinkler vehicle at different vehicle speeds and load values ​​through experiments:

[0041] With the water sprinkler truck on a flat road, the water sprinkler truck was driven at different speeds and the motor output torque required for stable driving was recorded as the reference torque for flat roads.

[0042] Repeat the above test process for typical load conditions to establish a reference torque mapping relationship for flat road driving under different vehicle speeds and load values. Typical load conditions include at least no load, half load and full load.

[0043] For atypical load conditions, an interpolation algorithm is used to obtain the reference torque for different load values ​​under atypical load conditions based on the fitting calculation results of adjacent load values ​​at the same vehicle speed.

[0044] The system includes pre-stored reference torque mapping relationships for flat road driving under typical load conditions and interpolation algorithms for non-typical load conditions.

[0045] In some embodiments, the water sprinkler vehicle balance control method further includes:

[0046] The safe speed threshold for sprinkler vehicles is negatively correlated with the absolute value of torque deviation.

[0047] In some embodiments, the water sprinkler vehicle balance control method further includes:

[0048] The water sprinkler vehicle is balanced under the condition that the vehicle speed is not lower than the preset starting threshold and the rate of change of the driver's pedal opening does not exceed the preset transient threshold.

[0049] According to a second aspect of this disclosure, a water sprinkler vehicle balance control device is proposed to implement the water sprinkler vehicle balance control method of the above embodiments.

[0050] According to a third aspect of this disclosure, an electric sprinkler vehicle is provided, including a vehicle controller and a power system. The vehicle controller includes the sprinkler vehicle balance control device described in the above embodiments, and the power system includes:

[0051] The power supply includes multiple branches connected in parallel, each branch is equipped with a battery pack and a boost converter, and each branch is independently configured with a battery management system, which is communicatively connected to the vehicle controller.

[0052] The AC power supply components include a first drive motor, a second drive motor, and a hydraulic motor, wherein the first drive motor is configured to drive a first wheel, and the second drive motor is configured to drive a second wheel; and

[0053] The high-voltage power distribution unit is electrically connected between the power source and the AC power components via an inverter. The high-voltage power distribution unit is configured to collect and distribute power from the power source.

[0054] In some embodiments, the electric sprinkler vehicle further includes:

[0055] Low-voltage electrical components; and

[0056] An isolated DC-DC converter is electrically connected between the power source and low-voltage electrical components via a step-down converter.

[0057] Based on the above technical solution, the water sprinkler vehicle balance control method of this disclosure determines that the water sprinkler vehicle is in a swaying condition when the water sprinkler vehicle is in an uphill or downhill condition and the absolute value of the vehicle speed change rate is not less than the first risk threshold. At the same time, the water sprinkler vehicle is controlled in terms of water spraying status and vehicle torque. This can effectively suppress the longitudinal disturbance and vehicle pitch phenomenon caused by liquid swaying, improve the driving stability of the water sprinkler vehicle, and ensure the safe operation of the water sprinkler vehicle. Attached Figure Description

[0058] The accompanying drawings, which are included to provide a further understanding of this disclosure and form part of this application, illustrate exemplary embodiments of this disclosure and are used to explain this disclosure, but do not constitute an undue limitation of this disclosure. In the drawings:

[0059] Figure 1 The flowcharts are for some embodiments of the water sprinkler vehicle balance control method disclosed herein.

[0060] Figure 2 Flowcharts showing some other embodiments of the water sprinkler vehicle balance control method disclosed herein.

[0061] Figure 3 This is a partial structural schematic diagram of some embodiments of the fire truck disclosed herein.

[0062] Figure 4 This is a schematic diagram illustrating the composition of some embodiments of the power system of the sprinkler vehicle disclosed herein. Detailed Implementation

[0063] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The descriptions of the exemplary embodiments are merely illustrative and are in no way intended to limit the present disclosure or its application or use. The present disclosure may be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided so that the present disclosure will be thorough and complete, and will fully express the scope of the disclosure to those skilled in the art. It should be noted that, unless specifically stated otherwise, the relative arrangement of components and steps, the composition of materials, numerical expressions, and values ​​set forth in these embodiments should be interpreted as exemplary only and not as limiting.

[0064] The terms "first," "second," and similar words used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. Words such as "including" or "contains" mean that the element preceding the word encompasses the element listed after it, and do not exclude the possibility of encompassing other elements as well. Terms such as "above," "below," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, this relative positional relationship may also change accordingly.

[0065] In this disclosure, when a specific device is described as being located between a first device and a second device, an intermediary device may or may not be present between the specific device and the first or second device. When a specific device is described as being connected to other devices, the specific device may be directly connected to the other devices without an intermediary device, or it may be not directly connected to the other devices but have an intermediary device.

[0066] All terms used in this disclosure (including technical or scientific terms) have the same meaning as understood by one of ordinary skill in the art to which this disclosure pertains, unless otherwise specifically defined. It should also be understood that terms defined in a general dictionary, such as a dictionary, should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and not as having an idealized or highly formalized meaning, unless expressly defined herein.

[0067] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0068] Based on the embodiments disclosed above, in the absence of explicit denial or conflict, the technical features of one embodiment may be advantageously combined with one or more other embodiments.

[0069] First, this disclosure provides a method for balancing a sprinkler vehicle, such as... Figures 1 to 3 As shown, the water sprinkler vehicle balance control method includes:

[0070] Step 110: Real-time acquisition of the water sprinkler vehicle's speed, motor output torque, driver's required torque, and load value;

[0071] Step 120: Obtain the reference torque for flat roads based on vehicle speed and load values, and obtain the torque deviation value based on the difference between the motor output torque and the reference torque for flat roads;

[0072] Step 130: Determine the driving conditions of the sprinkler truck based on the torque deviation value, motor output torque, and driver's required torque.

[0073] Step 140: When the water sprinkler vehicle is in an uphill or downhill driving condition, obtain the vehicle speed change rate. If the absolute value of the vehicle speed change rate is not less than the first risk threshold, it is determined that the water sprinkler vehicle is in an easily swaying condition, and the water sprinkler vehicle is controlled in terms of water spraying status and overall vehicle torque.

[0074] Among them, the water spraying status control includes at least one of water spraying power control and water spraying direction control, and the vehicle torque control includes at least one of limiting the torque change rate of the motor output torque, applying pitch compensation torque, and distributing torque to the left and right wheels.

[0075] The required torque for the driver can be obtained by adjusting the opening of the accelerator or brake pedal. The load value of the water sprinkler vehicle is the weight of the water stored in the water tank. The water sprinkler vehicle disclosed here is an ultra-large tonnage pure electric mining water sprinkler vehicle, with a vehicle body mass of not less than 100t and a full-load load value of not less than 100t for the water tank. The absolute value of the torque deviation represents the additional torque demand caused by the additional resistance of the current road slope; the larger the absolute value of the torque deviation, the steeper the current road slope. The first risk threshold can be determined through calibration tests of actual vehicles under conditions such as rapid acceleration and deceleration on slopes, and can be set in grades according to the slope level and load status.

[0076] The vehicle speed, motor output torque, driver-required torque, and load values ​​of the sprinkler truck are all collected in real time during vehicle operation. The collected speed signal is processed using a moving average filter, and the torque signal is processed using a mean filter to suppress sensor noise and instantaneous fluctuations caused by CAN bus signal transitions. A sliding window differentiation is performed on the filtered speed signal, and the average speed change rate within the window is calculated as a criterion for speed stability. Furthermore, the timestamps of each collected signal are aligned to ensure that the speed, torque, and load values ​​used in the calculation within the same calculation cycle correspond to the values ​​at the same physical moment.

[0077] Steps 120 to 150 are executed sequentially. Step 110 can be executed entirely before step 120, and the real-time acquisition of the driver's required torque can also be executed between steps 120 and 130. In step 120, the reference torque for flat roads is obtained based on vehicle speed and load value. This requires querying the historical flat road database based on the current vehicle speed signal and load value. The historical flat road database is established through pre-conducted flat road tests and is pre-stored in the control device. If the current load value is consistent with the calibrated load value, the corresponding reference torque value for flat roads is read directly. If the current load value is between two calibrated load values, linear interpolation or spline interpolation methods are used to fit and calculate the reference torque for flat roads corresponding to the current load value based on adjacent load values.

[0078] In some embodiments, before obtaining the reference torque for flat road based on vehicle speed and load value, the method further includes establishing a mapping relationship between the reference torque for flat road driving of the sprinkler vehicle at different vehicle speeds and load values ​​through experiments:

[0079] With the water sprinkler truck on a flat road, the water sprinkler truck was driven at different speeds and the motor output torque required for stable driving was recorded as the reference torque for flat roads.

[0080] Repeat the above test process for typical load conditions to establish a reference torque mapping relationship for flat road driving under different vehicle speeds and load values. Typical load conditions include at least no load, half load and full load.

[0081] For atypical load conditions, an interpolation algorithm is used to obtain the reference torque for different load values ​​under atypical load conditions based on the fitting calculation results of adjacent load values ​​at the same vehicle speed.

[0082] The system includes pre-stored reference torque mapping relationships for flat road driving under typical load conditions and interpolation algorithms for non-typical load conditions.

[0083] Water sprinkler vehicles are more prone to swaying when operating on uphill or downhill slopes. Therefore, the water sprinkler vehicle balance control method disclosed herein determines that the water sprinkler vehicle is in a swaying condition when it is operating on an uphill or downhill slope and the absolute value of the rate of change of vehicle speed is not less than a first risk threshold. At the same time, it controls the water spraying state and the overall vehicle torque, which can effectively suppress the longitudinal disturbance and vehicle pitch phenomenon caused by liquid swaying, improve the driving stability of the water sprinkler vehicle, and ensure the operation safety of the water sprinkler vehicle. The active balance control method disclosed herein, which first determines whether the vehicle is in a swaying condition and then, under the premise of the swaying condition, reduces the computational load of the control device and improves the control accuracy.

[0084] Optionally, typical load conditions may also include other load conditions, such as 20% of full load, 40% of full load, 60% of full load, and 80% of full load.

[0085] When the vehicle speed is lower than the preset starting threshold, or when the rate of change of the driver's pedal opening exceeds the preset transient threshold, the vehicle is determined to be in an unstable driving state. The working condition determination logic of this disclosure is not executed, and vehicle balance control is performed after the signal returns to stability.

[0086] Specifically, based on the vehicle speed signal and load value at the current moment, the flat road driving resistance torque reference database is queried. If the current load is consistent with the calibrated load state, the corresponding reference torque value is directly read. If the current load is between two calibrated load states, linear interpolation or spline interpolation methods are used to fit and calculate the theoretical flat road reference torque corresponding to the current load based on the adjacent load reference values.

[0087] In some embodiments, the water sprinkler vehicle balance control method further includes:

[0088] The water sprinkler vehicle is balanced under the condition that the vehicle speed is not lower than the preset starting threshold and the rate of change of the driver's pedal opening does not exceed the preset transient threshold.

[0089] This embodiment determines the vehicle speed and pedal change rate, limiting the balance control of the sprinkler vehicle to a relatively steady driving range. This avoids control misjudgments or overcompensation caused by transient conditions such as just starting or emergency acceleration and deceleration, thereby improving the smoothness and safety of the sprinkler vehicle's balance control.

[0090] In some embodiments, sprinkler power control includes:

[0091] If the absolute value of the rate of change of vehicle speed is less than the first risk threshold, the water sprinkler truck will spray water at the first power.

[0092] If the absolute value of the rate of change of vehicle speed is not less than the first risk threshold and not greater than the second risk threshold, the water sprinkler vehicle shall spray water at the second power.

[0093] If the absolute value of the rate of change of vehicle speed is greater than the second risk threshold, the water sprinkler truck will spray water at the third power.

[0094] The first risk threshold is less than the second risk threshold, the first power is less than the second power, and the second power is less than the third power.

[0095] Optionally, the first power can be a conventional power, the second power can be a medium power, the third power can be the maximum power or peak power, and the second risk threshold can be twice the first risk threshold.

[0096] This embodiment adjusts the water spraying power according to the sway risk level of the water sprinkler vehicle. The higher the sway risk level, the higher the water spraying power. This can offset and reduce the impact of vehicle swaying on the liquid in the water tank, thereby reducing vehicle swaying by reducing liquid swaying. At the same time, increasing the water spraying power can suppress road dust with a denser water mist, stabilize tire adhesion, and also help improve the driving stability of the water sprinkler vehicle.

[0097] In some embodiments, spray direction control includes:

[0098] When the water truck is working uphill, making the main spraying direction of the water truck to the rear can reduce the adverse effects of the water tank's center of gravity shifting backward due to the uphill slope.

[0099] When a water truck is going downhill, making the main spraying direction forward helps to reduce the adverse effects of the water tank's center of gravity shifting forward due to the downhill slope.

[0100] This embodiment changes the water spraying direction according to the uphill and downhill conditions, which can reduce the changes in the center of gravity of the water tank and the center of gravity of the water spraying vehicle caused by the liquid displacement in the water tank, thereby improving the vehicle balance control.

[0101] Optionally, some of the spray nozzles on the water tank can be positioned higher up within the tank to prioritize the discharge of liquid that has shifted above the centerline due to gravity. This further reduces the negative impact of liquid sloshing and improves vehicle balance control. Optionally, the specific spray angle of the water tank nozzles can be determined through center of gravity optimization tests.

[0102] In some embodiments, determining the driving condition of the sprinkler vehicle based on the torque deviation value, the motor output torque, and the driver's required torque includes:

[0103] If the driver's required torque is positive and the torque deviation is greater than the uphill threshold, the sprinkler truck is determined to be in uphill condition.

[0104] When the driver's required torque is positive and the torque deviation is less than the first downhill threshold, the sprinkler truck is determined to be in the first downhill condition. The downhill slope percentage of the first downhill condition is not greater than the preset slope percentage.

[0105] When the driver's required torque is negative, the motor output torque is negative, and the absolute value of the sum of the motor output torque and the flat road reference torque is greater than the second downhill threshold, the sprinkler vehicle is determined to be in the second downhill condition, and the downhill slope percentage of the second downhill condition is greater than the preset slope percentage.

[0106] Downhill driving conditions include a first downhill condition and a second downhill condition. The first downhill condition corresponds to a gentle downhill condition, and the second downhill condition corresponds to a steep downhill condition. Optionally, the preset slope percentage can be 3%, etc. When the sprinkler truck is in the first downhill condition, such as a small slope of 2% or 3%, the forward component of gravity is less than the vehicle's own driving resistance. If the accelerator is not pressed, the vehicle speed will gradually decrease. Therefore, the driver will lightly press the accelerator to output a small positive torque to maintain a stable speed; that is, the torque required by the driver is a positive value.

[0107] When a water truck is on a second downhill slope, the absolute value of the sum of the motor output torque and the reference torque for flat roads exceeds the second downhill threshold. For example, if gravity strongly propels the vehicle, the motor must brake forcefully. The motor output torque is -150 N·m, the reference torque for flat roads is 100 N·m, and the second downhill threshold is 30 N·m. Since |-150+100|>30, it is determined to be a steep downhill slope condition.

[0108] This embodiment determines the driving conditions of the sprinkler vehicle based on the torque deviation value, the motor output torque, and the torque required by the driver, providing an accurate basis for judging the vehicle's driving status during balance control, thereby improving the driving stability of the sprinkler vehicle.

[0109] In some embodiments, determining the driving condition of the sprinkler vehicle based on the torque deviation value, the motor output torque, and the driver's required torque further includes:

[0110] If the absolute value of the torque deviation is less than the flat road determination threshold and the vehicle speed changes gradually, the water sprinkler vehicle is determined to be in flat road condition.

[0111] Specifically, the uphill threshold, the first downhill threshold, the second downhill threshold, and the flat road judgment threshold are all determined through actual vehicle calibration tests, and are calibrated differently according to different load conditions. Under non-typical load conditions, the corresponding thresholds are obtained by interpolation using the same method as the flat road reference torque.

[0112] In some embodiments, limiting the rate of change of the motor output torque includes:

[0113] The stringency of the limitation on the rate of change of motor output torque is directly proportional to the magnitude of the absolute value of the torque deviation; and / or

[0114] When the water sprinkler truck is working uphill, the negative torque change rate of the motor output torque is limited; when the water sprinkler truck is working downhill, the positive torque change rate of the motor output torque is limited.

[0115] The stringency of the limitation on the rate of change of motor output torque is directly proportional to the absolute value of the torque deviation. That is, the larger the absolute value of the torque deviation, the stricter the limitation on the rate of change of torque, which reduces the swaying of the sprinkler truck on steep slopes. The steeper the slope, the more unstable the sprinkler truck is, and the stronger the amplification effect of gravity on the vehicle's dynamics. At this point, any tiny change in torque can be amplified by gravity into a violent impact or swaying. Therefore, the steeper the slope, the stricter the limitation on the rate of change of torque.

[0116] In uphill conditions, the focus is on limiting the rate of torque decrease, i.e., the negative rate of torque change, to prevent violent pitching due to power interruption. In downhill conditions, the focus is on limiting the rate of torque increase, i.e., the positive rate of torque change, to prevent the sprinkler vehicle from accelerating out of control due to the superposition of gravity and motor driving force. This embodiment can smooth the motor output torque, thereby improving the driving stability of the sprinkler vehicle.

[0117] In some embodiments, limiting the rate of change of the motor output torque includes:

[0118] When the water sprinkler truck is in an uphill or downhill condition, the water sprinkler truck is subjected to a typical slope acceleration / braking test to obtain the torque change rate threshold that keeps the vehicle in balance.

[0119] An interpolation algorithm is used to calculate the torque change rate threshold corresponding to atypical slopes based on the fitting calculation results of the torque change rate threshold of adjacent slopes.

[0120] When the water sprinkler truck is operating uphill or downhill, the torque change rate of the water sprinkler truck shall not exceed the torque change rate threshold.

[0121] This embodiment calibrates the torque change rate threshold through slope testing and extends it to the entire slope by combining interpolation algorithms. It can accurately limit the torque change rate of the motor output torque for various slope conditions, effectively reducing the pitching impact caused by acceleration and deceleration on slopes, thereby improving the driving stability of the sprinkler vehicle.

[0122] In some embodiments, applying pitch compensation torque includes:

[0123] The pitching moment is calculated based on the vehicle speed change rate, the total mass of the water sprinkler vehicle, and the equivalent cylinder arm. The total mass of the water sprinkler vehicle is equal to the sum of the vehicle body mass and the load value; the pitching moment is equal to the vehicle speed change rate multiplied by the total mass of the water sprinkler vehicle multiplied by the equivalent lever arm.

[0124] The control motor outputs a pitch compensation torque that is equal in magnitude but opposite in direction to the pitch torque.

[0125] The direction of the pitch compensation torque is opposite to the pitch movement tendency of the sprinkler truck. By actively applying a torque opposite to the pitch tendency, the tendency of the sprinkler truck's front end to nod or rise can be suppressed. The core of the pitch compensation torque calculation is inertial torque compensation. When the vehicle accelerates, the pitch tendency is to tilt backward, and the pitch compensation torque can suppress the front end to rise; when the vehicle decelerates, the pitch tendency is to nod forward, and the pitch compensation torque can suppress the nodning tendency of the sprinkler truck.

[0126] In some embodiments, distributing torque between the left and right wheels includes:

[0127] Real-time acquisition of steering wheel angle and lateral acceleration of sprinkler trucks;

[0128] The steering state of the sprinkler vehicle is determined based on the steering wheel angle and lateral acceleration. The torque of the left and right wheels is distributed according to the steering state. The steering state includes at least one of the following: straight driving condition, lateral disturbance condition, and active steering condition.

[0129] This embodiment determines the steering state of the sprinkler vehicle by using steering wheel angle and lateral acceleration. It can distinguish between lateral disturbances such as straight driving and crosswinds and active turning, and then perform torque distribution to the left and right wheels to improve the steering stability of the sprinkler vehicle.

[0130] In some embodiments, determining the steering state based on the steering wheel angle and lateral acceleration, and distributing torque to the left and right wheels based on the steering state includes:

[0131] When the steering wheel angle is less than the steering threshold and the lateral acceleration is less than the lateral acceleration threshold, the sprinkler vehicle is determined to be in a straight-line driving condition, so that the torque of the left and right wheels is equal and both are the side wheel reference torque. The side wheel reference torque is half of the sum of the torque required by the driver and the pitch compensation torque.

[0132] When the steering wheel angle is less than the steering threshold and the lateral acceleration is not less than the lateral acceleration threshold, the sprinkler vehicle is determined to be in a lateral disturbance condition. The lateral compensation torque is calculated based on the lateral acceleration and load value. The differential torque distribution is performed on the left and right wheels based on the side wheel reference torque and the lateral compensation torque.

[0133] When the steering wheel angle is greater than the steering threshold, the sprinkler vehicle is determined to be in active steering mode. The steering compensation torque is calculated based on the steering wheel angle and vehicle speed, and differential torque is distributed to the left and right wheels based on the side wheel reference torque and the steering compensation torque.

[0134] The steering threshold and lateral acceleration threshold are statistically calibrated using actual driving data.

[0135] When the sprinkler truck is traveling straight, the torque is symmetrically distributed to the left and right wheels. When the sprinkler truck is experiencing lateral disturbance, based on the symmetrical distribution, the lateral compensation torque is calculated according to the estimated lateral acceleration and load, and the left and right wheels are differentially distributed. For example, first, the average torque is calculated as a reference according to the symmetrical mode, and then the lateral compensation torque is calculated as f(lateral acceleration, estimated load). If an external force forces the vehicle to turn right, the control device will calculate a compensation value that makes the torque of the left wheel slightly less than that of the right wheel, generating a yaw moment to the left to counteract the crosswind. Finally, the torque is distributed as follows: left wheel torque = side wheel reference torque (reference value) - lateral compensation torque / 2, right wheel torque = side wheel reference torque (base value) + lateral compensation torque / 2.

[0136] When the sprinkler truck is under lateral disturbance conditions, the steering compensation torque is calculated based on the steering wheel angle and vehicle speed, and differential distribution is performed on the left and right wheels. For example, the average torque is calculated as a reference according to the symmetrical mode, and then the steering compensation torque is calculated as g(steering wheel angle, vehicle speed). If turning left, the control device will calculate a compensation value that makes the torque of the right wheel greater than that of the left wheel, generating a yaw moment to assist steering. Finally, the torque is distributed as follows: left wheel torque = side wheel reference torque (base value) - steering compensation torque / 2, right wheel torque = side wheel reference torque (base value) + steering compensation torque / 2.

[0137] This embodiment distributes torque evenly under straight driving conditions without steering or sideslip; under lateral disturbance conditions such as crosswinds, it calculates lateral compensation torque based on load value and lateral acceleration to actively correct deviation; during active turning, it calculates steering compensation torque based on vehicle speed and steering wheel angle to assist in cornering, which can suppress unexpected yaw, enhance assisted steering, and improve the steering stability of the sprinkler vehicle.

[0138] In some embodiments, the water sprinkler vehicle balance control method further includes:

[0139] The safe speed threshold for sprinkler vehicles is negatively correlated with the absolute value of torque deviation.

[0140] The absolute value of the torque deviation reflects the steepness of the slope. The safe speed threshold is dynamically adjusted based on the torque deviation value, so that the steeper the slope, the lower the permissible safe speed threshold, thus improving the driving safety and stability of the sprinkler truck. The safe speed threshold can be calibrated through testing.

[0141] Secondly, this disclosure also provides a water sprinkler vehicle balance control device for implementing the water sprinkler vehicle balance control method of the above embodiments.

[0142] The water sprinkler vehicle balancing control device can be a general-purpose processor, programmable logic controller (PLC), digital signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, or any suitable combination thereof, for performing the functions described in this disclosure. The water sprinkler vehicle balancing control device can also be a control device integrating a programmable, read-and-store computer system, and can be integrated into the vehicle controller.

[0143] During their research, the inventors also discovered a conflict between the demands of engineering operations and the compatibility of the power system. To meet the requirements of heavy-duty, long-range, and continuous high-intensity operations in mines, electric sprinkler vehicles need to be equipped with large-capacity battery packs and high-power electric drive systems, which brings about multiple technical challenges, such as high-voltage electrical architecture integration design, vehicle energy consumption optimization, and battery and motor thermal management under complex working conditions.

[0144] To address at least one of the aforementioned problems, this disclosure also proposes an electric sprinkler vehicle, including a vehicle controller and a power system. The vehicle controller includes the sprinkler vehicle balance control device described in the above embodiments, such as... Figure 4 As shown, the power system includes:

[0145] The power supply 1 includes multiple branches connected in parallel. Each branch is equipped with a battery pack 11 and a boost converter 12, and each branch is independently configured with a battery management system. The battery management system is communicatively connected to the vehicle controller.

[0146] AC power component 2 includes a first drive motor 21, a second drive motor 22, and a hydraulic motor 23. The first drive motor 21 is configured to drive a first wheel, and the second drive motor 22 is configured to drive a second wheel.

[0147] The high-voltage power distribution unit 3 is electrically connected between the power source and the AC power components via the inverter 4. The high-voltage power distribution unit 3 is configured to collect and distribute the power from the power source 1.

[0148] Both the first drive motor 21 and the second drive motor 22 are wheel-side drive motors, which can improve the power response speed and provide a hardware basis for differential torque distribution between the left and right wheels. The boost converter 12 can be a DC-DC converter, which can boost the voltage of the battery pack 11 to over 1000 volts and aggregate it to the high-voltage distribution unit (PDU). The inverter 4 is also known as a DC-AC converter.

[0149] Each branch is equipped with an independent battery management system, which can communicate with the vehicle controller in real time via the CAN bus to achieve independent monitoring and rapid fault isolation control of each branch's battery pack. For example, based on the status data of each branch's battery pack collected by the battery management system and combined with historical fault data, the vehicle controller determines the branch that has reached the fault threshold, immediately executes voltage reduction, disconnection, and fault reporting for the faulty branch, and quickly implements the voltage balancing strategy for the remaining healthy branch's battery packs to ensure that the power source still has enough energy to support the vehicle's return to the repair point.

[0150] In some embodiments, such as Figure 4 As shown, the first drive motor 21 and / or the second drive motor 22 are connected to the braking resistor 24, which is configured to recover energy to charge the battery pack 11 during vehicle braking. This embodiment reduces energy consumption by charging the battery pack 11 through the braking resistor.

[0151] In some embodiments, such as Figure 4 As shown, the power system also includes:

[0152] Low-voltage electrical components 5; and

[0153] An isolated DC-DC converter 6 is electrically connected between the power supply 1 and the low-voltage electrical component 5 via a step-down converter 7.

[0154] Low-voltage electrical components 5 may include fans and low-voltage batteries, etc. The step-down converter 7 may be a DC-DC converter.

[0155] This embodiment achieves electrical isolation by setting an isolated DC-DC converter 6, which can prevent low-voltage electrical components 5 from directly contacting the high voltage of the power grid and ensure electrical safety.

[0156] In some specific embodiments, the power system disclosed herein includes a multi-branch battery pack, a DC-DC converter, a PDU distribution unit, a DC-AC, a drive motor, a hydraulic motor, and a fan.

[0157] The vehicle's power source consists of multiple battery packs connected in parallel, with each battery pack branch also having an independent DC-DC converter connected in series. These DC-DC converters boost the battery pack voltage to over 1000 volts and aggregate it to the PDU distribution unit, which then centrally supplies power to the drive and hydraulic systems. Each battery pack branch is equipped with an independent BMS, communicating in real-time with the vehicle control unit (VCU) via a CAN bus to achieve independent monitoring of each battery pack branch and rapid fault isolation control.

[0158] The drive system is a wheel-side drive architecture, consisting of two independent drive motors and wheel-side reducers. Each drive motor is equipped with a DC-AC converter, which converts the high-voltage DC power from the PDU into AC power to drive the vehicle. In addition, each drive motor also has a braking resistor, which recovers energy during vehicle braking to charge the battery, thereby reducing energy consumption.

[0159] The DCAC hydraulic system converts the high-voltage DC power from the PDU into AC power via an integrated DCAC converter, which is used to drive lifting and steering operations. The drive system and hydraulic system are decoupled, enabling power distribution and coordinated control between the two systems. The power boosted by each branch DC-DC converter is then transmitted via an isolated DC-DC converter to power the fan and low-voltage power supply, among other things.

[0160] This embodiment utilizes a dual-wheel drive pure electric power architecture, which not only completely eliminates dependence on fossil fuels and achieves zero emissions, but also improves power response efficiency through an integrated driving and braking design, and further optimizes energy consumption performance with the braking energy recovery function; the use of hydraulic motors for independent steering and lifting effectively solves the conflict between driving and operating power, and is specifically adapted to the use needs of ultra-large tonnage mining sprinkler trucks; the innovative design of a multi-branch battery system not only meets the installation requirements in mining scenarios and improves spatial adaptability, but also ensures the voltage consistency of each branch cell through equalization control technology, extending battery life.

[0161] The foregoing has provided a detailed description of a water sprinkler vehicle balance control method, control device, and electric water sprinkler vehicle. Specific embodiments have been used to illustrate the principles and implementation methods of this disclosure. These embodiments are merely illustrative and are intended to aid in understanding the method and its core concepts. It should be noted that those skilled in the art can make various improvements and modifications to this disclosure without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims of this disclosure.

Claims

1. A method of balancing a water-sprinkling vehicle, characterized by, include: The vehicle speed, motor output torque, driver-required torque, and load value of the sprinkler vehicle are acquired in real time. The reference torque for flat road is obtained based on the vehicle speed and the load value, and the torque deviation value is obtained based on the difference between the motor output torque and the reference torque for flat road. The driving conditions of the sprinkler vehicle are determined based on the torque deviation value, the motor output torque, and the driver's required torque. When the water sprinkler vehicle is in an uphill or downhill driving condition, the vehicle speed change rate of the water sprinkler vehicle is obtained. If the absolute value of the vehicle speed change rate is not less than the first risk threshold, the water sprinkler vehicle is determined to be in an easily swaying condition, and the water sprinkler vehicle is controlled in terms of water spraying status and overall vehicle torque. The water spraying status control includes at least one of water spraying power control and water spraying direction control, and the vehicle torque control includes at least one of limiting the torque change rate of the motor output torque, applying pitch compensation torque, and distributing torque to the left and right wheels.

2. The method of claim 1, wherein, The sprinkler power control includes: If the absolute value of the rate of change of vehicle speed is less than the first risk threshold, the water sprinkler vehicle is made to spray water at the first power. If the absolute value of the rate of change of vehicle speed is not less than the first risk threshold and not greater than the second risk threshold, the water sprinkler vehicle is made to sprinkle water at the second power. If the absolute value of the rate of change of vehicle speed is greater than the second risk threshold, the water sprinkler vehicle will spray water at the third power. The first risk threshold is less than the second risk threshold, the first power is less than the second power, and the second power is less than the third power.

3. The method of claim 1, wherein, The spray direction control includes: When the water sprinkler truck is in the uphill condition, the main water spraying direction of the water sprinkler truck is rearward. When the water sprinkler vehicle is in the downhill condition, the main water spraying direction of the water sprinkler vehicle is forward.

4. The method of claim 1, wherein, Determining the driving condition of the sprinkler vehicle based on the torque deviation value, the motor output torque, and the driver's required torque includes: If the required torque for the driver is positive and the torque deviation is greater than the uphill threshold, it is determined that the sprinkler vehicle is in an uphill condition. When the required torque for the driver is positive and the torque deviation is less than the first downhill threshold, the sprinkler vehicle is determined to be in the first downhill condition, and the downhill slope percentage of the first downhill condition is not greater than the preset slope percentage. When the driver's required torque is negative, the motor output torque is negative, and the absolute value of the sum of the motor output torque and the flat road reference torque is greater than the second downhill threshold, the sprinkler vehicle is determined to be in the second downhill condition. The downhill slope percentage of the second downhill condition is greater than the preset slope percentage. The downhill condition includes the first downhill condition and the second downhill condition.

5. The method of claim 1, wherein The rate of change of torque that limits the output torque of the motor includes: The stringency of the limitation on the rate of change of the motor output torque is proportional to the magnitude of the absolute value of the torque deviation; and / or When the water sprinkler vehicle is operating uphill, the negative torque change rate of the motor output torque is limited; when the water sprinkler vehicle is operating downhill, the positive torque change rate of the motor output torque is limited.

6. The water sprinkler vehicle balance control method according to claim 1, characterized in that, The rate of change of torque that limits the output torque of the motor includes: When the water sprinkler vehicle is in an uphill or downhill condition, the water sprinkler vehicle is subjected to a typical slope acceleration / braking test to obtain the torque change rate threshold that keeps the vehicle in balance. An interpolation algorithm is used to calculate the torque change rate threshold corresponding to atypical slopes based on the fitting calculation results of the torque change rate threshold of adjacent slopes. When the water sprinkler vehicle is operating on an uphill or downhill slope, the torque change rate of the water sprinkler vehicle shall not exceed the torque change rate threshold.

7. The water sprinkler vehicle balance control method according to claim 1, characterized in that, The applied pitch compensation torque includes: The pitching moment is calculated based on the vehicle speed change rate, the total mass of the water sprinkler vehicle, and the equivalent cylinder arm. The total mass of the water sprinkler vehicle is equal to the sum of the vehicle body mass and the load value. The control motor outputs a pitch compensation torque that is equal in magnitude but opposite in direction to the pitch torque.

8. The water sprinkler vehicle balance control method according to claim 7, characterized in that, The distribution of torque to the left and right wheels includes: The steering wheel angle and lateral acceleration of the sprinkler vehicle are acquired in real time. The steering state of the sprinkler vehicle is determined based on the steering wheel angle and the lateral acceleration, and the torque of the left and right wheels is distributed according to the steering state. The steering state includes at least one of the following: straight driving condition, lateral disturbance condition, and active steering condition.

9. The water sprinkler vehicle balance control method according to claim 8, characterized in that, The steering state is determined based on the steering wheel angle and the lateral acceleration, and the torque is distributed to the left and right wheels based on the steering state, including: When the steering wheel angle is less than the steering threshold and the lateral acceleration is less than the lateral acceleration threshold, the sprinkler vehicle is determined to be in the straight-going condition, so that the torque of the left and right wheels is equal and both are the side wheel reference torque. The side wheel reference torque is half of the sum of the driver's required torque and the pitch compensation torque. When the steering wheel angle is less than the steering threshold and the lateral acceleration is not less than the lateral acceleration threshold, it is determined that the sprinkler vehicle is in the lateral disturbance condition. The lateral compensation torque is calculated based on the lateral acceleration and the load value. The differential torque distribution is performed on the left and right wheels based on the side wheel reference torque and the lateral compensation torque. When the steering wheel angle is greater than the steering threshold, the sprinkler vehicle is determined to be in the active steering condition. The steering compensation torque is calculated based on the steering wheel angle and the vehicle speed. The differential torque distribution is performed on the left and right wheels based on the side wheel reference torque and the steering compensation torque.

10. The water sprinkler vehicle balance control method according to any one of claims 1 to 9, characterized in that, Before obtaining the reference torque for flat road based on the vehicle speed and the load value, the process also includes establishing a mapping relationship between the reference torque for flat road driving of the sprinkler vehicle under different vehicle speeds and load values ​​through experiments: With the water sprinkler vehicle on a flat road, the water sprinkler vehicle was driven stably at different speeds, and the motor output torque required for stable driving was recorded as the reference torque for flat roads. Repeat the above test process for typical load conditions to establish a reference torque mapping relationship for flat road driving under different vehicle speeds and load values. The typical load conditions include at least no load, half load and full load. For atypical load conditions, an interpolation algorithm is used to obtain the reference torque for different load values ​​under atypical load conditions based on the fitting calculation results of adjacent load values ​​at the same vehicle speed. The reference torque mapping relationship for flat road driving under typical load conditions and the interpolation algorithm under atypical load conditions are pre-stored.

11. The water sprinkler vehicle balance control method according to any one of claims 1 to 9, characterized in that, Also includes: The safe speed threshold of the sprinkler vehicle is negatively correlated with the absolute value of the torque deviation.

12. The water sprinkler vehicle balance control method according to any one of claims 1 to 9, characterized in that, Also includes: The water sprinkler vehicle is balanced under the condition that the vehicle speed is not lower than the preset starting threshold and the rate of change of the driver's pedal opening does not exceed the preset transient threshold.

13. A water sprinkler vehicle balance control device, characterized in that, Used to implement the water sprinkler vehicle balance control method as described in any one of claims 1 to 12.

14. An electric sprinkler vehicle, characterized in that, The system includes a vehicle controller and a power system, wherein the vehicle controller includes the water sprinkler vehicle balance control device as described in claim 13, and the power system includes: The power supply includes multiple branches connected in parallel, each branch is equipped with a battery pack and a boost converter, and each branch is independently configured with a battery management system, which is communicatively connected to the vehicle controller. An AC power supply component includes a first drive motor, a second drive motor, and a hydraulic motor, wherein the first drive motor is configured to drive a first wheel, and the second drive motor is configured to drive a second wheel; and A high-voltage power distribution unit is electrically connected between the power source and the AC power-consuming components via an inverter. The high-voltage power distribution unit is configured to collect and distribute power from the power source.

15. The electric sprinkler vehicle according to claim 14, characterized in that, The power system also includes: Low-voltage electrical components; and An isolated DC-DC converter is electrically connected between the power source and the low-voltage electrical components via a step-down converter.

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