Electric motor grader and high-voltage system, control method and device, medium and product thereof

Abstract

This disclosure provides an electric grader and its high-voltage system, control method, device, medium, and product. The high-voltage system includes: multiple battery packs, multiple first DC-DC converters, a power distribution unit, a first main branch, a second main branch, a second DC-DC converter, and multiple auxiliary branches; wherein, the multiple battery packs are electrically connected one-to-one to the first terminals of the multiple first DC-DC converters, the second terminals of the multiple first DC-DC converters are electrically connected to the power distribution unit, the power distribution unit is electrically connected to the first main branch and the second main branch, the second terminals of the multiple first DC-DC converters are also electrically connected to the first terminals of the second DC-DC converter, the second terminals of the second DC-DC converter are electrically connected to the multiple auxiliary branches, and the second DC-DC converter is an isolated DC-DC converter; wherein, the first main branch is used to drive the walking motor, the second main branch is used to drive the hydraulic motor, and the multiple auxiliary branches are used to supply power to the low-voltage battery and the vehicle auxiliary load.

Description

Technical Field

[0001] This disclosure relates to the field of engineering machinery technology, and in particular to an electric grader and its high-voltage system, control method, device, medium and product. Background Technology

[0002] With the advancement of intelligent and green transformation of mines, traditional fuel-fired mining graders are gradually being replaced by pure electric models. Ultra-large tonnage pure electric mining graders need to operate continuously under high load, strong impact, and multiple obstacle conditions, which places high demands on the reliability and stability of their high-voltage systems, as well as the impact bearing capacity and control precision of their electric drive systems.

[0003] The inventors of this disclosure have discovered that the high-voltage system of pure electric graders for mining has significant bottlenecks in related technologies: these high-voltage systems often adopt a single-voltage-level architecture, the main drive circuit and auxiliary power supply circuit are not completely isolated, and load fluctuations can easily affect the auxiliary system; direct parallel connection of battery packs can easily generate problems such as circulating current and voltage difference, and a single group failure may cause the entire machine to shut down; the walking drive and hydraulic drive are not completely decoupled, which can easily damage core electrical components. This results in low reliability of electric graders in related technologies. Summary of the Invention

[0004] One technical problem addressed by this disclosure is the low reliability of electric graders in related technologies.

[0005] According to one aspect of this disclosure, a high-voltage system for an electric grader is provided, comprising: multiple battery packs, multiple first DC-DC converters, a power distribution unit, a first main branch, a second main branch, a second DC-DC converter, and multiple auxiliary branches; wherein the multiple battery packs are electrically connected to the first terminals of the multiple first DC-DC converters in a one-to-one correspondence, the second terminals of the multiple first DC-DC converters are electrically connected to the power distribution unit, the power distribution unit is electrically connected to the first main branch and the second main branch, the second terminals of the multiple first DC-DC converters are also electrically connected to the first terminals of the second DC-DC converters, the second terminals of the second DC-DC converters are electrically connected to the multiple auxiliary branches, and the second DC-DC converters are isolated DC-DC converters; wherein the first main branch is used to drive a walking motor, the second main branch is used to drive a hydraulic motor, and the multiple auxiliary branches are used to supply power to a low-voltage battery and an on-board auxiliary load.

[0006] In some embodiments, the first main branch includes a first pre-charging circuit and a first DC-AC converter, wherein a first terminal of the first pre-charging circuit is electrically connected to the power distribution unit, a second terminal of the first pre-charging circuit is electrically connected to a first terminal of the first DC-AC converter, and a second terminal of the first DC-AC converter is electrically connected to the walking motor; the second main branch includes a second pre-charging circuit and a second DC-AC converter, wherein a first terminal of the second pre-charging circuit is electrically connected to the power distribution unit, a second terminal of the second pre-charging circuit is electrically connected to a first terminal of the second DC-AC converter, and a second terminal of the second DC-AC converter is electrically connected to the hydraulic motor.

[0007] In some embodiments, the on-board auxiliary load includes a thermal management system and an air conditioning system; the plurality of auxiliary branches include a first auxiliary branch, a second auxiliary branch, and a third auxiliary branch; wherein, the first auxiliary branch includes a third DC-DC converter, wherein the third DC-DC converter is disposed between the second DC-DC converter and the low-voltage battery; the second terminal of the second DC-DC converter is electrically connected to the thermal management system through the second auxiliary branch; the second terminal of the second DC-DC converter is electrically connected to the air conditioning system through the third auxiliary branch.

[0008] According to another aspect of this disclosure, an electric grader is provided, comprising: a high-pressure system as described above.

[0009] According to another aspect of this disclosure, a control method for an electric grader is provided, comprising: obtaining hydraulic pressure information of the blade of the electric grader during operation, torque information output by the electric drive system of the electric grader, and posture information of the blade; calculating a pressure change rate based on the hydraulic pressure information, and calculating a torque change rate based on the torque information; when the pressure change rate is greater than or equal to a first pressure change rate threshold, the torque change rate is greater than or equal to a first torque change rate threshold, and an abnormal posture of the blade is determined based on the posture information of the blade, inputting the pressure change rate, the torque change rate, and the posture information of the blade into a pre-trained impact prediction model, so that the impact prediction model outputs an impact level and an obstacle type; and controlling the electric grader to perform a release control based on the impact level and the obstacle type.

[0010] In some embodiments, the attitude information of the shovel blade includes the tilt angle of the shovel blade and the height of the shovel blade; determining that the attitude of the shovel blade is abnormal based on the attitude information includes: determining that the attitude of the shovel blade is abnormal when the tilt angle of the shovel blade is greater than or equal to a tilt angle threshold, or when the height of the shovel blade is greater than or equal to a height threshold.

[0011] In some embodiments, the impact level includes mild impact and severe impact; wherein, when the pressure change rate is greater than or equal to the first pressure change rate threshold and less than or equal to the second pressure change rate threshold, and the torque change rate is greater than or equal to the first torque change rate threshold and less than or equal to the second torque change rate threshold, the impact level is mild impact; when the pressure change rate is greater than the second pressure change rate threshold, or the torque change rate is greater than the second torque change rate threshold, the impact level is severe impact.

[0012] In some embodiments, the types of obstacles include: small rigid obstacles, large fixed obstacles, and trapping obstacles.

[0013] In some embodiments, based on the impact level and the type of obstacle, controlling the electric grader to perform release control includes: when the impact level is a mild impact and the obstacle is a small rigid obstacle, controlling the electric drive system to reduce the output torque within a first predetermined time period, and after reducing the output torque, gradually increasing the output torque to a set target torque value based on a smooth torque output curve, and simultaneously controlling the hydraulic system to perform unloading operation, and controlling the blade to lift over the obstacle, and resetting after overcoming the obstacle.

[0014] In some embodiments, based on the impact level and the type of obstacle, controlling the electric grader to perform release control includes: when the impact level is a severe impact and the obstacle is a large fixed obstacle, controlling the electric drive system to reduce the output torque by a predetermined amount, simultaneously controlling the electric grader to reduce its travel speed, controlling the hydraulic system to perform a graded unloading operation, controlling the blade to adaptively lift according to the height of the obstacle, and planning a lateral offset path based on the vehicle posture and working boundary data of the electric grader, and controlling the electric grader to travel and bypass the obstacle based on the lateral offset path.

[0015] In some embodiments, based on the impact level and the type of obstacle, controlling the electric grader to perform release control includes: when the impact level is a severe impact and the obstacle is a trapping obstacle, controlling the electric drive system to reduce the output torque within a second predetermined time to relieve the sudden impact load; after reducing the output torque, controlling the electric drive system to output a corresponding torque while the motor is running at a predetermined speed; and controlling the hydraulic system to alternately perform pressurization and unloading operations to drive the blade to reciprocate; and adjusting the tilt angle of the blade and raising the height of the blade to release the blade jamming; wherein the predetermined speed is less than the rated speed of the motor.

[0016] In some embodiments, the control method further includes: obtaining the motor vibration frequency and vehicle position and attitude of the electric grader; and after determining that the electric grader has been freed from the obstacle based on the pressure change rate, the torque change rate, the motor vibration frequency, and the vehicle position and attitude, controlling the electric grader to return to the normal operation control mode.

[0017] According to another aspect of this disclosure, a control device for an electric grader is provided, comprising: a memory; and a processor coupled to the memory, the processor being configured to execute the control method as described above based on instructions stored in the memory.

[0018] According to another aspect of this disclosure, an electric grader is provided, comprising: the control device as described above.

[0019] According to another aspect of this disclosure, a computer-readable storage medium is provided having computer instructions stored thereon that, when executed by a processor, implement the control method as described above.

[0020] According to another aspect of this disclosure, a computer program product is provided, comprising a computer program or instructions that, when executed by a processor, implement the control method as described above.

[0021] In the aforementioned high-voltage system, by using isolated DC-DC converters to isolate the main branch from the auxiliary branch, load fluctuations are less likely to affect the auxiliary system. Multiple battery packs are connected in parallel via multiple first DC-DC converters, rather than directly, which reduces issues such as circulating current and voltage differential, and makes it less likely for a single battery pack failure to cause a complete machine shutdown. Furthermore, by setting up two main branches, the walking drive and hydraulic drive are decoupled, thereby reducing the possibility of damage to core electrical components. This improves the reliability of the electric grader.

[0022] Other features and advantages of this disclosure will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0023] The accompanying drawings, which form part of this specification, illustrate embodiments of this disclosure and, together with the specification, serve to explain the principles of this disclosure.

[0024] This disclosure will become clearer with reference to the accompanying drawings and the following detailed description, wherein: Figure 1 This is a schematic block diagram illustrating the structure of a high-voltage system for an electric grader according to some embodiments of the present disclosure; Figure 2 This is a flowchart illustrating a control method for an electric grader according to some embodiments of the present disclosure; Figure 3 This is a flowchart illustrating a control method for an electric grader according to other embodiments of the present disclosure; Figure 4 This is a structural block diagram illustrating a control device for an electric grader according to some embodiments of the present disclosure; Figure 5 This is a structural block diagram illustrating a control device for an electric grader according to other embodiments of the present disclosure. Detailed Implementation

[0025] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present disclosure.

[0026] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0027] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this disclosure or its application or use.

[0028] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0029] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0030] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0031] Figure 1 This is a schematic block diagram illustrating the structure of a high-voltage system for an electric grader according to some embodiments of the present disclosure.

[0032] like Figure 1 As shown, the high-voltage system includes: multiple battery packs 1 to n (n is a positive integer greater than or equal to 2), multiple first DC-DC converters (Direct Current to Direct Current Converters) 101, a power distribution unit (PDU) 110, a first main branch 21, a second main branch 22, a second DC-DC converter 102, and multiple auxiliary branches (e.g., auxiliary branches 31 to 34).

[0033] The multiple battery packs are electrically connected one-to-one to the first terminals of the multiple first DC-DC converters 101. The second terminals of the multiple first DC-DC converters 101 are electrically connected to the power distribution unit 110. For example, the second terminals of the multiple first DC-DC converters 101 are electrically connected to the first terminals of the power distribution unit 110 via a high-voltage bus. For example, the voltage on the high-voltage bus is not less than 1000V. The power distribution unit (PDU) 110 (e.g., the second terminal of the power distribution unit 110) is electrically connected to the first main branch 21 and the second main branch 22. The second terminals of the multiple first DC-DC converters 101 are also electrically connected to the first terminals of the second DC-DC converter 102. The second terminal of the second DC-DC converter 102 is electrically connected to the multiple auxiliary branches. The second DC-DC converter 102 is an isolated DC-DC converter.

[0034] like Figure 1 As shown, the high-voltage system adopts a multi-branch energy distribution architecture. Multiple battery packs are boosted and combined to a high-voltage bus of no less than 1000V via an independent first DC-DC converter. After distribution by the PDU, the two main branches drive the walking motor and hydraulic motor independently via the pre-charging circuit and DC-AC inverter, respectively. Multiple auxiliary branches supply power to the low-voltage battery, TMS, air conditioning and other systems. Each branch is independently controlled and does not interfere with each other.

[0035] The high-voltage system is equipped with two or more large-capacity power battery packs. Each battery pack is equipped with an independent DC-DC converter. Each converter has voltage regulation, current limiting, protection and communication functions and is electrically isolated from the corresponding battery pack. The outputs of all converters are connected in parallel to a high-voltage bus of not less than 1000V and connected to the PDU unit. A single branch fault can be independently shut down and isolated without affecting the normal power supply of the other battery packs.

[0036] An independent isolated DC / DC converter (second DC-DC converter) is installed, which draws power from the total output of the battery pack, and supplies power to the vehicle's auxiliary bus after isolation and voltage reduction, and is electrically isolated from the main drive high-voltage circuit.

[0037] The first main branch 21 is used to drive the walking motor 213. For example, as Figure 1 As shown, the first main branch 21 includes a first pre-charging circuit 211 and a first DC-AC converter (Direct Current to Alternating Current Converter) 212. A first terminal of the first pre-charging circuit 211 is electrically connected to a power distribution unit (PDU) 110. A second terminal of the first pre-charging circuit 211 is electrically connected to a first terminal of the first DC-AC converter 212. The second terminal of the first DC-AC converter 212 is electrically connected to a walking motor 213.

[0038] The second main branch 22 is used to drive the hydraulic motor 223. For example, as Figure 1 As shown, the second main branch 22 includes a second pre-charging circuit 221 and a second DC-AC converter 222. The first terminal of the second pre-charging circuit 221 is electrically connected to the power distribution unit 110. The second terminal of the second pre-charging circuit 221 is electrically connected to the first terminal of the second DC-AC converter 222. The second terminal of the second DC-AC converter 222 is electrically connected to the hydraulic motor 223.

[0039] Here, the PDU serves as the core of the main high-voltage power distribution and outputs two independent drive branches, each equipped with an independent pre-charging circuit: the walking drive branch consists of a first pre-charging circuit, a first DC-AC inverter, and a walking motor connected in series; the hydraulic drive branch consists of a second pre-charging circuit, a second DC-AC inverter, and a hydraulic motor connected in series. The two drive branches are electrically independent and do not interfere with each other.

[0040] The aforementioned auxiliary branches supply power to the low-voltage battery 41 and the on-board auxiliary load 42. For example, the on-board auxiliary load 42 includes a thermal management system (TMS) 421 and an air conditioning system 422. The input and / or output voltage of the low-voltage battery is lower than the voltage on the high-voltage bus (i.e., the voltage output from the second terminal of the first DC-DC converter). For example, the input and / or output voltage of the low-voltage battery is 24V.

[0041] For example, the plurality of auxiliary branches include a first auxiliary branch 31, a second auxiliary branch 32, and a third auxiliary branch 33. The first auxiliary branch 31 may include a third DC-DC converter 103. The third DC-DC converter 103 is disposed between the second DC-DC converter 102 and the low-voltage battery 41. A first terminal of the third DC-DC converter 103 is electrically connected to a second terminal of the second DC-DC converter 102, and the second terminal of the third DC-DC converter 103 is electrically connected to the low-voltage battery 41. For example, the third DC-DC converter 103 transmits a 24V voltage to the low-voltage battery 41. The second terminal of the second DC-DC converter 102 is electrically connected to a thermal management system (TMS) 421 via the second auxiliary branch 32. The second terminal of the second DC-DC converter 102 is electrically connected to an air conditioning system 422 via the third auxiliary branch 33.

[0042] For example, the vehicle auxiliary load 42 may also include other systems 423, and the plurality of auxiliary branches may also include a fourth auxiliary branch 34. The second terminal of the second DC-DC converter 102 is electrically connected to the other systems 423 through the fourth auxiliary branch 34.

[0043] In other words, the auxiliary power supply unit is powered by an isolated DC-DC converter to supply power to the vehicle's high-voltage auxiliary loads such as the TMS thermal management and air conditioning system, and has no direct electrical connection with the main drive bus; the low-voltage battery supplies power to low-voltage equipment such as the vehicle controller, sensors, instruments and solenoid valves.

[0044] Thus, a high-voltage system for an electric grader according to some embodiments of the present disclosure is provided. The high-voltage system includes: multiple battery packs, multiple first DC-DC converters, a power distribution unit, a first main branch, a second main branch, a second DC-DC converter, and multiple auxiliary branches; wherein the multiple battery packs are electrically connected one-to-one to the first terminals of the multiple first DC-DC converters, the second terminals of the multiple first DC-DC converters are electrically connected to the power distribution unit, the power distribution unit is electrically connected to the first main branch and the second main branch, the second terminals of the multiple first DC-DC converters are also electrically connected to the first terminals of the second DC-DC converters, and the second terminals of the second DC-DC converters are electrically connected to the multiple auxiliary branches, wherein the second DC-DC converter is an isolated DC-DC converter; wherein the first main branch is used to drive a walking motor, the second main branch is used to drive a hydraulic motor, and the multiple auxiliary branches are used to supply power to a low-voltage battery and an onboard auxiliary load. In this high-voltage system, by using isolated DC-DC converters to isolate the main branch from the auxiliary branch, load fluctuations are less likely to affect the auxiliary system. Multiple battery packs are connected in parallel via multiple first DC-DC converters, rather than directly, which reduces issues such as circulating current and voltage differential, and makes it less likely for a single battery pack failure to cause a complete machine shutdown. Furthermore, by setting up two main branches, the walking drive and hydraulic drive are decoupled, thereby reducing the possibility of damage to core electrical components. This improves the reliability of the electric grader.

[0045] In some embodiments of this disclosure, an electric grader is also provided, comprising: a high-pressure system as described above (e.g., as...). Figure 1 (High-voltage system shown).

[0046] The inventors of this disclosure have discovered that mining faces are riddled with obstacles, and the violent impact generated by the rigid contact between the shovel and these obstacles can shorten the lifespan of the electric drive system. Furthermore, electric drive systems in related technologies lack effective impact buffering mechanisms, offering only passive protection and failing to anticipate impact risks. Related technologies either only provide passive shock absorption or lack high-precision prediction models and graded control, resulting in low prediction accuracy, insufficient intelligence, and difficulty in adapting to complex mining conditions.

[0047] In view of this, embodiments of the present disclosure also provide a control method for an electric grader to enable advance prediction of impact level and obstacle type, and combined with release control to extend the service life of the core components of the equipment.

[0048] Figure 2 This is a flowchart illustrating a control method for an electric grader according to some embodiments of the present disclosure. This control method can be executed by a control device of the electric grader. Figure 2 As shown, the control method includes steps S202 to S208.

[0049] In step S202, the hydraulic pressure information of the blade of the electric grader during operation, the torque information output by the electric drive system of the electric grader, and the posture information of the blade are obtained.

[0050] For example, a pressure sensor (e.g., a high-frequency pressure sensor) can be added to the hydraulic circuit of the grader's blade. This sensor collects real-time hydraulic pressure changes during blade operation (as hydraulic pressure information). Alternatively, a torque sensor (e.g., a high-frequency non-contact torque sensor) can be integrated into the output of the electric drive system. This sensor collects real-time torque changes from the electric drive system (as torque information). Another example is a blade attitude sensor. This sensor collects real-time blade tilt and height signals, capturing changes in blade attitude when it contacts an obstacle. Here, the tilt and height signals are used together as blade attitude information. All sensors are connected to the electric grader's main controller (as a control device) via a CAN (Controller Area Network) bus, synchronously transmitting the real-time collected signals to the main controller.

[0051] In some embodiments, GPS (Global Positioning System) positioning sensors and gyroscope sensors can also be installed on the vehicle body to collect signals such as vehicle body tilt angle and driving direction, providing support for obstacle avoidance and obstacle trap detection.

[0052] In step S204, the pressure change rate is calculated based on the hydraulic pressure information, and the torque change rate is calculated based on the torque information.

[0053] For example, the control device (e.g., the main controller) has a built-in signal analysis module that performs real-time analysis on the pressure information (e.g., pressure change signal) and torque information (e.g., torque change signal) transmitted by the sensor, and obtains the pressure change rate and torque change rate through differential calculation.

[0054] In addition, the signal analysis module can also analyze the blade's posture information, capture the blade's posture change characteristics, and simultaneously identify the load impact precursor and obstacle contact signals.

[0055] In step S206, when the pressure change rate is greater than or equal to the first pressure change rate threshold, the torque change rate is greater than or equal to the first torque change rate threshold, and the blade posture is determined to be abnormal based on the blade posture information, the pressure change rate, torque change rate, and blade posture information are input into the pre-trained impact prediction model so that the impact prediction model outputs the impact level and the type of obstacle.

[0056] A preset impact precursor threshold is established, namely, a first pressure change rate threshold α and a first torque change rate threshold β. When the pressure change rate ≥ α, the torque change rate ≥ β, and the blade's posture is determined to be abnormal based on the blade's posture information, it is determined that there is a load impact precursor and the blade is in contact with an obstacle. The control device immediately initiates the impact prediction and obstacle identification process, that is, the pressure change rate, torque change rate, and blade posture information are input into a pre-trained impact prediction model so that the impact prediction model outputs the impact level and the type of obstacle.

[0057] If the above judgment conditions are not met, it is determined that there is no risk of impact and no contact with obstacles. The control device maintains the original control mode of the electric drive system and continues to execute the signal acquisition and analysis process.

[0058] For example, if the rate of change of pressure and the rate of change of torque are greater than or equal to their respective thresholds, but the blade posture is normal, it can be determined that there is no obstacle contact and no signs of impact, and the original control mode can be maintained.

[0059] For example, if only one of the two rates of change, pressure change rate and torque change rate, is greater than or equal to its corresponding threshold, and the other rate of change is less than its corresponding threshold, i.e., the double threshold condition is not met, then it is determined that there is no impact risk and monitoring continues.

[0060] For example, if both rates of change are normal (both rates of change are less than their respective thresholds), and only the blade posture is abnormal, then it is determined that there is a non-load impact type posture deviation, the status is only recorded, and the impact prediction and obstacle recognition process is not initiated.

[0061] In some embodiments, the first pressure change rate threshold α ranges from 1.2 MPa / s to 1.5 MPa / s.

[0062] In some embodiments, the first torque change rate threshold β ranges from 80 N. m / s to 100 N m / s.

[0063] It should be noted that the range of values ​​for α and β here is merely exemplary, and the scope of this disclosure is not limited thereto. Those skilled in the art can set specific values ​​for α and β according to actual needs.

[0064] In some embodiments, the blade's attitude information includes the blade's tilt angle and blade height. Determining an abnormal blade attitude based on the blade's attitude information includes: determining an abnormal blade attitude when the blade's tilt angle is greater than or equal to a tilt angle threshold, or the blade's height is greater than or equal to a height threshold.

[0065] If the tilt angle of the shovel is less than the tilt angle threshold and the height of the shovel is less than the height threshold, the shovel's posture is determined to be normal.

[0066] For example, the tilt angle threshold of the shovel is 8°, and the height threshold of the shovel is 120mm. Of course, these tilt angle and height thresholds are merely exemplary, and the scope of this disclosure is not limited thereto. Those skilled in the art can set specific values ​​for the tilt angle and height thresholds according to actual needs.

[0067] In some embodiments, the impact prediction model can be a hybrid deep learning model of CNN-LSTM (Convolutional Neural Network - Long Short-Term Memory). The control device calls a preset CNN-LSTM hybrid deep learning model, which has both impact prediction and obstacle recognition functions. It integrates real-time operating parameters and historical operation data to accurately predict the load impact level and obstacle type in advance (e.g., t1 time in advance), providing a basis for subsequent coordinated control.

[0068] In embodiments of this disclosure, an impact prediction model can be pre-built and trained. For example, pre-building and training an impact prediction model may include the following steps S1 to S4.

[0069] In step S1, historical data is collected. This involves collecting operational data for various load impact scenarios of the grader in mining operations. For example, operational data may include pressure change rate, torque change rate, soil hardness, blade posture, and obstacle size. Furthermore, this operational data may also include impact duration, electric drive system stress, vehicle displacement data, obstacle distribution data, and terrain data.

[0070] For example, electric drive system stress may include: mechanical stress data generated by the operation of motor or transmission components; obstacle distribution data may include: information on the location, density and arrangement of obstacles in the work area; terrain data may include: information on the slope, flatness, soil quality, and topographic relief of the work surface.

[0071] Impact duration can be used to help calibrate impact strength, refine impact levels, and improve classification accuracy. Vehicle displacement changes can help distinguish between obstacle crossing and obstacle trapping conditions, and identify obstacle types. Stress in the electric drive system can be correlated with the impact on power components, helping to determine severe impacts. Obstacle distribution and terrain data can facilitate the LSTM module to mine temporal patterns, predict impact development trends, and optimize obstacle recognition accuracy.

[0072] In step S2, the job data is preprocessed. For example, the original job data is filtered, distorted data is removed, missing data is supplemented using linear interpolation, and all data is standardized.

[0073] In step S3, model building. A CNN-LSTM hybrid deep learning algorithm architecture can be used to build a hybrid model that combines impact prediction and obstacle recognition: the CNN module is responsible for extracting instantaneous feature information (including change peaks, change slopes, feature inflection points, etc.) of pressure change rate, torque change rate, and blade posture signal, capturing the instantaneous features of load impact and signal features when in contact with obstacles; the LSTM module is responsible for mining the correlation between historical operation data (soil hardness, obstacle size, obstacle distribution, terrain data, etc.) and real-time operating parameters, capturing the dynamic change trend of load impact and the characteristic patterns of obstacles, and simultaneously achieving accurate early prediction of impact level and obstacle type. The model input includes the current pressure change rate, torque change rate, blade posture signal, etc. Optionally, the model input can also include soil hardness. The model output is the impact level and obstacle type.

[0074] In step S4, model training and validation. The preprocessed standardized dataset is divided into training, validation, and test sets. The model is iteratively trained using the training set, and its hyperparameters are dynamically adjusted using the validation set to optimize performance. The model's prediction accuracy is validated using the test set. The model is considered successful when its impact prediction accuracy is greater than or equal to the impact prediction accuracy threshold ε. pth Obstacle recognition accuracy ≥ obstacle recognition accuracy threshold ε ith Furthermore, if the prediction advance time error is less than or equal to the prediction time error threshold t6 (and t6 < t1), the model will be solidified into the embedded storage unit of the control device after the preset performance index is achieved.

[0075] For example, the impact prediction accuracy threshold ε pth The range of values ​​for ε is pth ≥95%. For example, the obstacle recognition accuracy threshold ε ith The range of values ​​for is ε ith ≥93%. For example, the prediction time error threshold t6 has a range of t6≤20 ms (milliseconds). For example, the system's advance prediction duration t1 has a range of t1≥100 ms.

[0076] During training, when historical operational data (including pressure change rate, torque change rate, blade posture information, etc.) are input into the model, the impact level and obstacle type corresponding to each set of historical operational data are also used as ground truth values ​​to train the model. This way, when using the model for impact prediction and obstacle identification later, it can output the impact level and obstacle type.

[0077] In the training process of the impact prediction model in the above embodiment, the CNN module is responsible for extracting instantaneous feature information (including change peaks, change slopes, feature inflection points, etc.) of pressure change rate, torque change rate, and blade posture information. The LSTM module is responsible for mining the correlation between historical operation data (soil hardness, obstacle distribution, terrain data, etc.) and real-time operating parameters (pressure change rate, torque change rate, blade posture information), thereby mining the correlation between impact level and obstacle type and real-time operating parameters (pressure change rate, torque change rate, blade posture information). Therefore, after the impact prediction model is trained, in the actual impact prediction process, only the pressure change rate, torque change rate, and blade posture information need to be input into the impact prediction model. This is because the impact prediction model can combine the correlation between the already mined operation data (soil hardness, obstacle size, obstacle distribution, terrain data, etc.) and real-time operating parameters (pressure change rate, torque change rate, blade posture information), as well as the magnitude of the pressure change rate and the magnitude of the torque change rate, to obtain relevant data on impact level and obstacle, and then output the impact level and obstacle type.

[0078] In some embodiments, the impact level includes mild impact and severe impact. The impact level is mild when the rate of change of pressure is greater than or equal to a first pressure rate of change threshold α and less than or equal to a second pressure rate of change threshold γ, and the rate of change of torque is greater than or equal to a first torque rate of change threshold β and less than or equal to a second torque rate of change threshold δ; the impact level is severe when the rate of change of pressure is greater than the second pressure rate of change threshold, or the rate of change of torque is greater than the second torque rate of change threshold.

[0079] Here, the impact levels are divided into two levels.

[0080] Mild impact: The pressure change rate is in the range of α~γ and the torque change rate is in the range of β~δ. The intensity of this type of impact is low, but it will affect the smoothness and accuracy of equipment operation. It is mostly the contact impact of small rigid obstacles (described later) and can be mitigated by flexible buffering and instantaneous obstacle crossing.

[0081] Severe impact: Pressure change rate > γ (in this case, the torque change rate ≥ β has been determined in step S206), or torque change rate > δ (in this case, the pressure change rate ≥ α has been determined in step S206). This type of impact is of high intensity and causes significant damage to the core components of the electric drive system. It can easily lead to problems such as overheating of the motor windings, accelerated wear of the electric drive axle gears, and even failure of core components. It often corresponds to contact impacts with large fixed obstacles or trap-type obstacles (described later). It can be handled by rigid buffering combined with obstacle bypass / getting out of trouble. The constraint relationship of γ > α and δ > β always holds.

[0082] In some embodiments, the second pressure change rate threshold γ ranges from 3.5 MPa / s to 4.0 MPa / s.

[0083] In some embodiments, the second torque change rate threshold δ ranges from 260 N. m / s to 300 N m / s.

[0084] It should be noted that the range of values ​​for γ and δ here is merely exemplary, and the scope of this disclosure is not limited thereto. Those skilled in the art can set specific values ​​for γ and δ according to actual needs.

[0085] In some embodiments, the types of obstacles include: small rigid obstacles, large fixed obstacles, and trap obstacles.

[0086] Here, obstacles are categorized as follows: Based on their size, characteristics, and impact on the operation, obstacles can be classified into three categories: (1) Small rigid obstacles: including small obstacles whose diameter is ≤ diameter threshold d1 and whose height is ≤ height threshold h1, such as small stones, hard soil blocks, and piles of gravel. These obstacles are small in size and hard, and produce a slight impact when in contact. They can be crossed by slightly lifting them with a shovel without causing equipment to get stuck.

[0087] (2) Large fixed obstacles: including large obstacles with a diameter > d1 or a height > h1, such as large rocks, abandoned structures, large pipes, etc. These obstacles are large in volume and fixed, and generate a heavy impact when in contact. They cannot be lifted and crossed by a shovel, but can be bypassed by lateral offset.

[0088] (3) Obstacles that cause entrapment: These include semi-buried stones, obstacles on soft ground, obstacles in muddy areas, etc. These obstacles can easily cause the shovel blade to get stuck and the vehicle body to get stuck. When they come into contact, they will cause a heavy impact and need to be removed through an escape operation.

[0089] The height threshold h1 is the minimum lift height threshold, and the diameter threshold d1 is the threshold for the horizontal dimension of the obstacle. For example, h1 is 50 mm. For example, h1 < d1. For example, the diameter threshold d1 is 150 mm.

[0090] Of course, the values ​​of the diameter threshold d1 and the height threshold h1 are merely exemplary, and the scope of this disclosure is not limited thereto. Those skilled in the art can set specific values ​​of d1 and h1 according to actual needs.

[0091] In some embodiments, the type of obstacle may include small rigid obstacles and large fixed obstacles. That is, in some embodiments, the type of obstacle may include two categories, namely small rigid obstacles and large fixed obstacles, excluding trap-type obstacles.

[0092] In step S208, based on the impact level and the type of obstacle, the electric grader is controlled to perform release control.

[0093] In this step, the control device issues corresponding control commands based on the impact level and obstacle type output by the hybrid deep learning model, so as to perform graded collaborative flexible buffering and differentiated obstacle avoidance / getting out of trouble linkage control on the electric grader.

[0094] As mentioned earlier, mild impacts generally correspond to small rigid obstacles, while severe impacts generally correspond to large fixed obstacles or trap-like obstacles. Therefore, in some embodiments of this disclosure, obstacle avoidance / getting out of trouble control can be performed for the three working conditions of "mild impact + small rigid obstacle", "severe impact + large fixed obstacle" and "severe impact + trap-like obstacle", without controlling other working conditions, because other working conditions are basically non-existent or rarely exist.

[0095] In other embodiments, obstacle avoidance or escape control can also be performed for two working conditions: "mild impact + small rigid obstacle" and "severe impact + large fixed obstacle".

[0096] (1) Mild impact + small rigid obstacle

[0097] In some embodiments, step S208 may include: when the impact level is a mild impact and the obstacle is a small rigid obstacle, controlling the electric drive system to reduce the output torque within a first predetermined time (e.g., 0.3s), and after reducing the output torque, gradually increasing the output torque to a set target torque value (e.g., 90% of the rated operating torque of the electric drive system) based on a smooth torque output curve, and simultaneously controlling the hydraulic system to perform an unloading operation, and controlling the blade to lift over the obstacle, and then resetting after overcoming the obstacle. This achieves the purpose of obstacle avoidance or escape control for working conditions where the impact level is a mild impact and the obstacle is a small rigid obstacle. Here, the values ​​of the first predetermined time and the target torque value are merely exemplary, and the scope of this disclosure is not limited thereto. Those skilled in the art can set specific values ​​of the first predetermined time and the target torque value according to actual needs.

[0098] For example, if the current impact level is determined to be a minor impact and the obstacle ahead is a small, rigid obstacle, the control device will control the electric grader to prioritize short-term torque reduction for buffering. The control device can momentarily and slightly reduce the drive torque to offset the instantaneous impact of the obstacle and prevent damage to the transmission gears; during the obstacle-crossing cycle, the original linear steep torque increase strategy is abandoned, and a smooth curve is used to gradually increase the torque to the set target torque value to avoid secondary impacts caused by sudden power changes. Simultaneously, the hydraulic system is moderately unloaded to reduce the cutting load on the blade; the blade is controlled to briefly and slightly rise to cross the obstacle and quickly return to its original position upon landing. After the obstacle is cleared, the electric drive, hydraulic system, and blade all return to normal control, and the equipment operates without interruption.

[0099] For example, the control device (i.e., the main controller) can regulate the electric drive system to perform a short-term torque reduction operation, that is, to momentarily and slightly reduce the drive torque. The torque reduction range is set to η1 (consistent with the minimum torque reduction range of a slight impact, for example, η1=0.2 (minimum torque reduction ratio)), and the maintenance time (i.e. the first predetermined time mentioned above) is t2. This avoids the electric drive axle gear wear and motor speed fluctuation caused by obstacle impact, while reserving time for the blade to be lifted.

[0100] After performing a short-term torque reduction operation, the control device can further regulate the electric drive system, changing the original linear torque output curve into a smooth curve, such as the curve constructed by the improved logistic function, whose expression is: (1) Where T(t) is the real-time torque output value of the electric drive system at a certain time t, T0 is the target torque value, k is the curve slope adjustment coefficient, and t0 is the midpoint of the buffer time. Through this expression (1), the torque output can be smoothly increased, effectively avoiding the impact superposition effect caused by rigid torque output, and further improving the buffering effect. For example, a buffer period (i.e., buffer time) can be set. During this period, the torque of the electric drive system increases smoothly from the current value according to the curve of expression (1), gradually approaching the target torque value T0, ensuring that the torque change is stable and effectively mitigating impact vibration.

[0101] The control device synchronously regulates the relief valve of the hydraulic system to achieve graded unloading control. The pressure after unloading can be controlled between the first pressure threshold P1 and the second pressure threshold P2, reducing the cutting resistance of the blade, avoiding blade damage caused by hard contact between the blade and obstacles, and mitigating the instantaneous force of load impact on the electric drive system.

[0102] The control device synchronously regulates the blade mechanism to perform small, rapid lifting and lowering actions. For example, the lifting height is set to h1 (which is consistent with the minimum lifting height for a light impact), the lifting time is t3, and the lowering time is t4 (both t3 and t4 are less than t2). This enables rapid lifting to overcome obstacles and a quick drop back to the original working height, avoiding bumps or depressions on the working surface and ensuring operational accuracy.

[0103] For example, t3 and t4 are both 0.1s. Of course, the values ​​of t3 and t4 here are merely exemplary, and the scope of this disclosure is not limited thereto. Those skilled in the art can set specific values ​​of t3 and t4 according to actual needs.

[0104] After overcoming the obstacle, the electric drive system and hydraulic system return to normal operation; the blade maintains its original working posture to ensure uninterrupted operation and prevent deviation, minimizing the impact on work efficiency.

[0105] (2) Severe impact + large fixed obstacle

[0106] In some embodiments, step S208 may include: when the impact level is severe and the obstacle is a large, fixed obstacle, controlling the electric drive system to reduce the output torque by a predetermined amount, simultaneously controlling the electric grader to reduce its travel speed, controlling the hydraulic system to perform a graded unloading operation, controlling the blade to adaptively lift according to the height of the obstacle, and planning a lateral offset path based on the electric grader's vehicle posture and work boundary data, and controlling the electric grader to travel and bypass the obstacle based on the lateral offset path. This achieves the purpose of obstacle avoidance or escape control in situations where the impact level is severe and the obstacle is a large, fixed obstacle.

[0107] For example, if the current impact level is determined to be a severe impact and the obstacle ahead is a large, fixed obstacle, the control device immediately reduces the torque of the electric drive system by significantly decreasing the load, simultaneously reducing the vehicle speed. This low load helps avoid potential damage to the motor and transmission components caused by the hard-top obstacle. Simultaneously, the hydraulic system is unloaded in stages, and the blade is adaptively raised according to the obstacle's height to avoid its top surface. Then, based on the vehicle's posture and work boundary data, a slightly lateral deviation path is planned to complete the obstacle avoidance. After the obstacle avoidance is complete and the impact has subsided, the control device smoothly and gradually increases the torque to normal values, and the blade, hydraulic system, and vehicle speed are reset sequentially. If there is insufficient working space to avoid the obstacle laterally, the machine stops smoothly and an audible and visual alarm is triggered, prompting manual obstacle removal.

[0108] For example, the control device rapidly adjusts the electric drive system to achieve instantaneous attenuation of the output torque, with the attenuation amplitude adaptively adjusted based on the real-time impact intensity. For instance, when the pressure change rate > γ1 and / or the torque change rate > δ1, the torque attenuation amplitude is adjusted to the maximum value η2; when the pressure change rate is between γ and γ1 and the torque change rate is between δ and δ1, the torque attenuation amplitude is adjusted to between η1 and η2, maintaining a stable torque t5 time after attenuation (e.g., t5 is 0.5s to 0.7s), allowing sufficient operation time for obstacle avoidance. Simultaneously, the equipment's travel speed is reduced to allow time for obstacle avoidance path planning and execution. γ1 is the high pressure change rate threshold, δ1 is the high torque change rate threshold, and γ1 > γ, δ1 > δ. η1 is the minimum torque attenuation amplitude threshold (i.e., the minimum torque reduction ratio mentioned above), and η2 is the maximum torque attenuation amplitude threshold, and 0 < η1 < η2 < 1. For example, η1 = 0.2, η2 = 0.6.

[0109] In some embodiments, the high pressure change rate threshold γ1 ranges from 5 MPa / s to 6 MPa / s. In some embodiments, the high torque change rate threshold δ1 ranges from 3300 N. m / s to 3900N m / s. For example, the high torque change rate threshold δ1 is 3600 N. m / s. Of course, the ranges of values ​​for γ1 and δ1 here are merely exemplary, and the scope of this disclosure is not limited thereto. Those skilled in the art can set specific values ​​for γ1 and δ1 according to actual needs.

[0110] The control device synchronously regulates the hydraulic system to perform staged unloading. The unloading pressure is adaptively adjusted according to the impact intensity, which further alleviates the impact load on the electric drive system and provides hydraulic power support for lifting the blade.

[0111] Furthermore, the control device also sends commands to the hydraulic lifting mechanism of the shovel blade, driving the blade to adaptively lift. The lifting height is precisely matched according to the predicted size of the obstacle. When the predicted obstacle height is greater than h3, the blade lifting height is adjusted to between h4 and h2; when the predicted obstacle height is less than or equal to h3, the blade lifting height is adjusted to between h1 and h3. The blade lift avoids the top of the obstacle, preventing blade deformation and damage to the hydraulic mechanism caused by scraping or colliding with the obstacle. Here, h2 is the maximum lifting height threshold, h4 is the lifting height dividing threshold, and h1 < h3 < h4 < h2. For example, h1 is 50 mm.

[0112] The control device also sends lateral offset avoidance commands to the grader's travel control system. Based on the vehicle tilt angle and travel direction signals fed back by the vehicle attitude sensors, as well as the working boundary parameters (e.g., working width, road edge position), it automatically plans a small lateral offset path. The offset distance is set between the minimum offset distance s1 and the maximum offset distance s2 (s1 and s2 are adaptively set according to the working width to ensure that the offset does not exceed the working range). The grader is then controlled to slightly offset along the side of the obstacle to achieve obstacle avoidance. During the obstacle avoidance process, the vehicle attitude and obstacle position are monitored in real time to improve the accuracy of the obstacle avoidance path and avoid secondary collisions.

[0113] After the obstacle avoidance is completed and the impact is fully relieved, the control device regulates the torque of the electric drive system to gradually increase. The increase rate is set to ν×T0 / s (i.e., the torque increase per second is ν×T0), where ν is the speed coefficient, for example, ν is 0.3, T0 is the set target torque value, and s is seconds (time unit). This avoids a secondary impact caused by a rapid increase in torque and ensures that the electric drive system smoothly transitions to normal working conditions. The vehicle body posture is adjusted to the original working route, and the blade is slowly lowered to the original working height. The hydraulic system stops unloading, and the equipment travel speed returns to the normal working speed. Normal operation continues, ensuring that the working surface before and after the obstacle avoidance is continuous and the accuracy is consistent.

[0114] If a large fixed obstacle is located directly in front of the work route and it is impossible to bypass it laterally (e.g., due to limited work width), the control device can adjust the equipment to stop slowly and simultaneously issue an audible and visual alarm signal to remind the driver to manually clear the obstacle or adjust the work route to avoid equipment damage caused by forcibly bypassing the obstacle.

[0115] (3) Severe impact + trapping obstacles

[0116] In some embodiments, step S208 may include: when the impact level is severe and the obstacle is a trapping obstacle, controlling the electric drive system to reduce the output torque within a second predetermined time (e.g., 0.4s to 0.6s) to relieve the sudden impact load; after reducing the output torque, controlling the electric drive system to output a corresponding torque while the motor operates at a predetermined speed (e.g., 35% to 55% of the motor's rated speed); and controlling the hydraulic system to alternately perform pressurization and unloading operations to drive the blade to reciprocate; and adjusting the blade's tilt angle and lifting height to release blade jamming, with the predetermined speed being less than the motor's rated speed. Here, the values ​​of the second predetermined time and the predetermined speed are merely exemplary, and the scope of this disclosure is not limited thereto. Those skilled in the art can set specific values ​​for the second predetermined time and the predetermined speed according to actual needs.

[0117] For example, if the current impact level is determined to be a severe impact and the vehicle is stuck in an obstacle-prone area, the control device first momentarily reduces the output torque to relieve the sudden impact load; then it switches to a low-speed, high-torque mode, providing stable power at low speed to prevent the wheels from spinning at high speed and further sinking. The hydraulic system is intermittently started and stopped to pressurize and unload, causing the blade to swing back and forth slightly to break the ground's adhesion, while simultaneously fine-tuning the blade's tilt angle and raising its height to release any blade jamming. The system monitors the vehicle's displacement, torque pressure, and motor temperature in real time, and after confirming that the vehicle is out of trouble and the impact has been eliminated, all parameters gradually return to normal operating conditions. If the electric grader cannot get out of trouble for an extended period, the entire machine will activate an audible and visual alarm to alert the driver for manual assistance.

[0118] For example, the control device rapidly adjusts the electric drive system to achieve instantaneous attenuation of the output torque, with the attenuation range controlled between η1 and η2, maintaining a stable torque t5 after attenuation, quickly alleviating the impact of instantaneous shock loads on the core components of the electric drive system. Furthermore, the control device immediately switches the electric drive system to a low-speed, high-torque-to-get-out-of-traps mode, maintaining the output torque between T0×(1-η3) and T0×(1-η1) (adaptively adjusted according to the severity of trapping; the more severe the trapping, the greater the torque), and reducing the speed to ν1 to ν2 times the normal operating speed, avoiding secondary trapping caused by high-speed slippage, while simultaneously reducing the load on the electric drive system and preventing overheating of the motor due to prolonged trapping. Here, η3 is the extreme torque attenuation threshold, η3 < η1. For example, η3 = 0.1. ν1 is the first speed adjustment coefficient, and ν2 is the second speed adjustment coefficient, 0 < ν1 < ν2 < 1. For example, ν1 = 0.3, ν2 = 0.5, meaning the trapping speed is 0.3 to 0.5 times the normal speed.

[0119] The control device synchronously controls the hydraulic system to perform intermittent unloading and pressurization, driving the blade to swing up and down slightly (the swing amplitude is h1, and the swing frequency of the blade is in the range of f1 to f2, for example, f1=0.5 Hz, f2=1.5 Hz). The swing of the blade breaks the ground adhesion force, assisting the equipment to get out of the stuck area. At the same time, if there are hydraulic outriggers, they are controlled to provide slight support, increasing the ground clearance of the vehicle body, further assisting in getting out of trouble.

[0120] The control device can also adjust the blade mechanism, performing fine-tuning of the forward tilt angle (the adjustment angle is θ1 to θ2, where θ1 is the first tilt angle adjustment threshold and θ2 is the second tilt angle adjustment threshold, and 0° < θ1 < θ2 < 10°, for example, θ1 = 3°, θ2 = 8°), and raising the blade height (lifting height is h3 to h4), adjusting the blade posture, releasing the blade from the scraping state with obstacles, and reducing ground adhesion. θ1 and θ2 can be preset according to the blade model and working conditions to ensure that fine-tuning does not affect the accuracy of subsequent operations.

[0121] During the extrication process, the control device can monitor the torque change rate, pressure change rate, vehicle displacement signal, and electric drive system temperature signal in real time, establishing a dynamic monitoring mechanism for the extrication status: when the vehicle body begins to move smoothly, the torque change rate and pressure change rate drop to the normal range (pressure change rate < α, torque change rate < β), and the electric drive system temperature is within the normal range, it is determined that the extrication is successful and the impact is completely eliminated. Then, the electric drive system is gradually adjusted to the normal operating mode, the extrication torque mode is stopped, and the torque slowly recovers to the target torque value T0; the blade returns to its original working posture, the hydraulic system stops intermittent unloading and pressurization, and returns to normal operating status.

[0122] If the time spent stuck is greater than or equal to t7 (t7 is the timeout threshold for stuckness, for example, t7 is 10s), an audible and visual alarm signal will be issued simultaneously to remind the driver to intervene (such as clearing obstacles or assisting with traction) to avoid the electric drive system overheating and being damaged due to prolonged time spent getting out of trouble.

[0123] In this way, the control device can perform coordinated control of electric drive, hydraulic system, blade, and travel in three working conditions based on the impact level and obstacle type output by the model.

[0124] This provides a control method for an electric grader according to some embodiments of the present disclosure. The control method includes: obtaining hydraulic pressure information of the electric grader's blade during operation, torque information output by the electric drive system of the electric grader, and blade posture information; calculating a pressure change rate based on the hydraulic pressure information and a torque change rate based on the torque information; when the pressure change rate is greater than or equal to a first pressure change rate threshold, the torque change rate is greater than or equal to a first torque change rate threshold, and an abnormal blade posture is determined based on the blade posture information, inputting the pressure change rate, torque change rate, and blade posture information into a pre-trained impact prediction model, so that the impact prediction model outputs the impact level and obstacle type; and controlling the electric grader to perform release control based on the impact level and obstacle type. This control method can achieve advance prediction of impact level and obstacle type, and combined with release control (e.g., graded buffer control and obstacle crossing), extend the service life of the core components of the equipment.

[0125] In some embodiments, the control method may further include: obtaining the motor vibration frequency and vehicle position and attitude of the electric grader; and, after determining that the electric grader has detached from the obstacle based on the pressure change rate, torque change rate, motor vibration frequency, and vehicle position and attitude, controlling the electric grader to return to the normal operation control mode. That is, whether the electric grader has successfully detached can be determined by the pressure change rate, torque change rate, motor vibration frequency, and vehicle position and attitude, and after determining that it has detached from the obstacle, controlling the electric grader to return to the normal operation control mode.

[0126] The above embodiments realize the determination of impact elimination and obstacle handling completion and parameter adaptive recovery. By collecting four types of signals in real time, namely hydraulic pressure change rate, drive torque change rate, motor vibration frequency and vehicle position and attitude, multiple conditions are jointly used to determine whether the operation obstacle has been handled.

[0127] The impact is considered completely eliminated when the following conditions are met: the rate of change of pressure and the rate of change of torque return to the normal impact-free range; the motor vibration frequency stabilizes within the normal operating range and remains stable for a fixed period of time (i.e., exceeding the vibration stability duration threshold t8); and the vehicle body is determined to be free from obstacles and without jamming or entrapment based on its position and attitude. After the criteria are met, the control device gradually restores the drive torque, hydraulic pressure, blade height, and overall vehicle driving parameters, and the machine returns to the normal operation control mode.

[0128] For example, the normal operating range of the motor vibration frequency is f3 to f4. f3 is the lowest normal vibration frequency threshold, and f4 is the highest normal vibration frequency threshold. For example, f3 = 15 Hz, f4 = 35 Hz. Here, f3 and f4 can be set according to actual needs.

[0129] For example, the vibration stabilization duration threshold t8 is ≥ 300 ms, and t8 < t9, where t9 is the total duration for determining the completion of impact elimination and obstacle handling. For example, t9 ≥ 500 ms.

[0130] The vehicle's position and attitude can include information such as the electric grader's tilt angle and direction of travel. If the tilt angle is within the normal range and the direction of travel matches the predetermined target direction, then it is determined that the electric grader has cleared the obstacle without getting stuck or impeded.

[0131] Figure 3 This is a flowchart illustrating a control method for an electric grader according to some other embodiments of the present disclosure.

[0132] like Figure 3 As shown, the first step is signal acquisition. This involves real-time acquisition of signals such as hydraulic pressure changes during blade operation, torque changes from the electric drive system, blade tilt angle and height, and vehicle tilt angle and direction of travel. The blade tilt angle and height signals serve as the blade's attitude information.

[0133] Next, impact recognition is performed. When the pressure change rate is ≥ α, the torque change rate is ≥ β, and the blade's posture is determined to be abnormal based on the blade's posture information, it is determined that there is a precursor to load impact and the blade is in contact with an obstacle. The control device immediately starts the impact prediction and obstacle recognition process, that is, the pressure change rate, torque change rate, and blade posture information are input into the pre-trained impact prediction model.

[0134] If the above judgment conditions are not met, it is determined that there is no risk of impact, and the control device maintains the original control mode of the electric drive system and continues to execute the signal acquisition and analysis process.

[0135] Next, after inputting the pressure change rate, torque change rate, and blade attitude information into the pre-trained impact prediction model, the impact prediction model outputs the impact level and obstacle type.

[0136] Next, for minor impacts and small rigid obstacles, implement flexible buffering and instantaneous obstacle crossing control; for severe impacts and large fixed obstacles, implement rigid buffering and active obstacle crossing control; for severe impacts and trap-type obstacles, implement rigid buffering and escape and anti-trapping control.

[0137] Next, the determination of whether the impact elimination and obstacle handling are completed and the parameter adaptive recovery are performed.

[0138] The control device (e.g., the main controller) establishes a multi-parameter collaborative judgment mechanism to simultaneously monitor the impact elimination status and obstacle handling completion status. This ensures that parameter recovery is performed only after both buffer control and obstacle handling meet the standards, avoiding equipment damage or decreased operational accuracy due to misjudgment. The control device can monitor the pressure change rate, torque change rate, electric drive system vibration frequency (i.e., motor vibration frequency), and vehicle body displacement and attitude signals in real time. It determines that the load impact has been completely eliminated and obstacle handling is complete when the following four conditions are met simultaneously: (1) Pressure change rate < α, that is, the pressure change rate returns to the normal operating range; (2) The torque change rate is less than β, that is, the torque change rate returns to the normal operating range; (3) The vibration frequency of the electric drive system is stable within the normal operating vibration range of f3 to f4, and the duration exceeds the vibration stability duration threshold t8; (4) The vehicle body is not stuck and has left the obstacle area, and the vehicle body posture has returned to normal (obstacle avoidance scenario) or the shovel blade is not scratched and the vehicle body moves smoothly (getting out of trouble scenario).

[0139] Once the above conditions are met, the control device immediately issues a parameter recovery command to ensure that the equipment returns to normal operating status.

[0140] Next, iterative optimization of the model is performed. This involves iteratively updating the job data and adaptively optimizing the model.

[0141] After each closed-loop control operation is completed, the control device can synchronously update the data of this operation to the historical operation database. Local parameter adjustments and optimizations are performed on the model's feature extraction module (CNN module) and prediction output module (LSTM module).

[0142] For example, after a single obstacle crossing / getting out of trouble closed-loop operation is completed, the vehicle controller stores the data of this operation (sensor-collected data, control execution parameters, and impact handling results) into the historical database. It then uses newly added measured data to fine-tune the CNN-LSTM prediction model online, optimizes the CNN feature extraction weights and LSTM time-series prediction parameters, and continuously improves the accuracy of subsequent impact prediction and obstacle classification, enabling the control model to autonomously iterate and optimize according to the on-site conditions.

[0143] In the above embodiments, the impact level and obstacle type are predicted in advance by using a CNN-LSTM hybrid deep learning model in collaboration with multiple sensors. Combined with graded buffer control and obstacle crossing, the service life of the core components of the equipment is extended.

[0144] In some cases, different input feature parameters are selected for model training, depending on the type of engineering machinery.

[0145] This disclosure presents a high-voltage system for an ultra-large tonnage pure electric grader and an obstacle-crossing control method based on impact prediction. The high-voltage system employs a multi-branch energy distribution architecture. Multiple battery packs are boosted and combined to a high-voltage bus of no less than 1000V via independent DC-DC converters. After distribution by the PDU, two main branches independently drive the walking motor and hydraulic motor via pre-charging circuits and DC / AC inverters, respectively. Multiple auxiliary branches supply power to the low-voltage battery, TMS, air conditioning, and other systems. Each branch is independently controlled and does not interfere with others. Based on this, a CNN-LSTM hybrid deep learning prediction model is established. Through multi-dimensional sample training, accurate prediction of impact level and obstacle type is achieved. Based on this, graded buffering and differentiated obstacle avoidance / getting out of trouble strategies are executed. The model parameters are iteratively optimized through closed-loop operation data, enabling the grader to adapt to complex mining operation scenarios.

[0146] Figure 4 This is a structural block diagram illustrating a control device for an electric grader according to some embodiments of the present disclosure. The control device includes a memory 510 and a processor 520. Wherein: The memory 510 can be a disk, flash memory, or any other non-volatile storage medium. The memory is used for storage. Figure 2 and / or Figure 3 The instructions in the corresponding embodiment.

[0147] Processor 520 is coupled to memory 510 and can be implemented as one or more integrated circuits, such as a microprocessor or microcontroller. Processor 520 executes instructions stored in memory, enabling advance prediction of impact levels and obstacle types, and, combined with release control, extends the lifespan of core equipment components.

[0148] In some embodiments, it may also be as follows Figure 5As shown, the control device 500 includes a memory 510 and a processor 520. The processor 520 is coupled to the memory 510 via a BUS bus 530. The control device 500 can also be connected to an external storage device 550 via a storage interface 540 to access external data, and can also be connected to a network or another computer system (not shown) via a network interface 560, which will not be described in detail here.

[0149] In this embodiment, by storing data instructions in a memory and then processing the instructions by a processor, it is possible to predict the impact level and obstacle type in advance. Combined with release control, this extends the service life of the core components of the equipment.

[0150] In some embodiments of this disclosure, an electric grader is also provided, comprising: a control device as described above (e.g., as...). Figure 4 or Figure 5 The control device shown.

[0151] In some embodiments, the electric grader described above may also include the high-pressure system described above (e.g., such as...). Figure 1 (High-voltage system shown).

[0152] In some embodiments of this disclosure, a computer-readable storage medium (e.g., a non-transitory computer-readable storage medium) is also provided, having stored thereon computer program instructions that are implemented when executed by a processor. Figure 2 and / or Figure 3 The steps of the method in the corresponding embodiments are described. Those skilled in the art will understand that embodiments of this disclosure can be provided as methods, apparatus, or computer program products. Therefore, this disclosure can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this disclosure can take the form of a computer program product embodied on one or more computer-usable non-transitory storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0153] This disclosure is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create a machine for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1A device that provides the functions specified in one or more boxes.

[0154] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0155] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0156] In some embodiments of this disclosure, a computer program product is also provided, which includes a computer program or instructions that, when executed by a processor, implement the control method as described above.

[0157] In some embodiments of this disclosure, a computer program is also provided, comprising: instructions that, when executed by a processor, cause the processor to perform the control method as described above.

[0158] This concludes the detailed description of the present disclosure. To avoid obscuring the concept of the disclosure, some details known in the art have not been described. Those skilled in the art will fully understand how to implement the technical solutions disclosed herein based on the above description.

[0159] While specific embodiments of this disclosure have been described in detail by way of example, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of this disclosure. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this disclosure. The scope of this disclosure is defined by the appended claims.

Claims

1. A high-voltage system for an electric grader, comprising: Multiple battery packs, multiple first DC-DC converters, a power distribution unit, a first main branch, a second main branch, a second DC-DC converter, and multiple auxiliary branches; The plurality of battery packs are electrically connected to the first terminals of the plurality of first DC-DC converters in a one-to-one correspondence. The second terminals of the plurality of first DC-DC converters are electrically connected to the power distribution unit. The power distribution unit is electrically connected to the first main branch and the second main branch. The second terminals of the plurality of first DC-DC converters are also electrically connected to the first terminals of the second DC-DC converter. The second terminals of the second DC-DC converters are electrically connected to the plurality of auxiliary branches. The second DC-DC converter is an isolated DC-DC converter. The first main branch is used to drive the walking motor, the second main branch is used to drive the hydraulic motor, and the multiple auxiliary branches are used to supply power to the low-voltage battery and the vehicle auxiliary load.

2. The high-voltage system according to claim 1, wherein: The first main branch includes a first pre-charging circuit and a first DC-AC converter, wherein a first terminal of the first pre-charging circuit is electrically connected to the power distribution unit, a second terminal of the first pre-charging circuit is electrically connected to a first terminal of the first DC-AC converter, and a second terminal of the first DC-AC converter is electrically connected to the walking motor. The second main branch includes: a second pre-charge circuit and a second DC-AC converter, wherein the first terminal of the second pre-charge circuit is electrically connected to the power distribution unit, the second terminal of the second pre-charge circuit is electrically connected to the first terminal of the second DC-AC converter, and the second terminal of the second DC-AC converter is electrically connected to the hydraulic motor.

3. The high-voltage system according to claim 1 or 2, wherein: The on-board auxiliary loads include a thermal management system and an air conditioning system; The plurality of auxiliary branches include a first auxiliary branch, a second auxiliary branch, and a third auxiliary branch; The first auxiliary branch includes a third DC-DC converter, wherein the third DC-DC converter is disposed between the second DC-DC converter and the low-voltage battery; The second terminal of the second DC-DC converter is electrically connected to the thermal management system via the second auxiliary branch; The second terminal of the second DC-DC converter is electrically connected to the air conditioning system via the third auxiliary branch.

4. An electric motor grader comprising: The high-voltage system as described in any one of claims 1 to 3.

5. A control method for an electric grader as described in claim 4, comprising: The hydraulic pressure information of the blade of the electric grader during operation, the torque information output by the electric drive system of the electric grader, and the attitude information of the blade are obtained. The pressure change rate is calculated based on the hydraulic pressure information, and the torque change rate is calculated based on the torque information. When the pressure change rate is greater than or equal to a first pressure change rate threshold, the torque change rate is greater than or equal to a first torque change rate threshold, and the attitude of the shovel blade is determined to be abnormal based on the attitude information of the shovel blade, the pressure change rate, the torque change rate, and the attitude information of the shovel blade are input into a pre-trained impact prediction model so that the impact prediction model outputs the impact level and the type of obstacle. and Based on the impact level and the type of obstacle, the electric grader is controlled to perform a release control.

6. The control method according to claim 5, in, The attitude information of the shovel includes the tilt angle and the height of the shovel; Determining that the shovel's posture is abnormal based on its posture information includes: determining that the shovel's posture is abnormal when the shovel's tilt angle is greater than or equal to a tilt angle threshold, or when the shovel's height is greater than or equal to a height threshold.

7. The control method according to claim 5, wherein, The impact levels include mild impact and severe impact; Wherein, if the pressure change rate is greater than or equal to the first pressure change rate threshold and less than or equal to the second pressure change rate threshold, and the torque change rate is greater than or equal to the first torque change rate threshold and less than or equal to the second torque change rate threshold, the impact level is a mild impact. If the pressure change rate is greater than the second pressure change rate threshold, or the torque change rate is greater than the second torque change rate threshold, the impact level is a severe impact.

8. The control method according to claim 7, wherein, The types of obstacles include: small rigid obstacles, large fixed obstacles, and trap obstacles.

9. The control method according to claim 8, wherein, Based on the impact level and the type of obstacle, the electric grader is controlled to perform release control, including: When the impact level is mild and the obstacle is a small rigid obstacle, the electric drive system is controlled to reduce the output torque within a first predetermined time. After reducing the output torque, the output torque is gradually increased back to the set target torque value based on a smooth torque output curve. Simultaneously, the hydraulic system is controlled to perform unloading operation and the blade is controlled to lift over the obstacle and reset after overcoming the obstacle.

10. The control method according to claim 8, wherein, Based on the impact level and the type of obstacle, the electric grader is controlled to perform release control, including: When the impact level is severe and the obstacle is a large, fixed obstacle, the electric drive system is controlled to reduce the output torque by a predetermined amount, the electric grader is controlled to reduce its travel speed, the hydraulic system is controlled to perform a graded unloading operation, the blade is controlled to adaptively lift according to the height of the obstacle, and a lateral offset path is planned based on the vehicle posture and working boundary data of the electric grader. Based on the lateral offset path, the electric grader is controlled to travel and bypass the obstacle.

11. The control method according to claim 8, wherein, Based on the impact level and the type of obstacle, the electric grader is controlled to perform release control, including: When the impact level is severe and the obstacle is a trapping obstacle, the electric drive system is controlled to reduce the output torque within a second predetermined time to relieve the sudden impact load. After reducing the output torque, the electric drive system is controlled to output the corresponding torque while the motor is running at a predetermined speed, and the hydraulic system is controlled to alternately perform pressurization and unloading operations to drive the blade to swing back and forth, and to adjust the tilt angle of the blade and raise the height of the blade to release the blade jamming. The predetermined speed is less than the rated speed of the motor.

12. The control method according to claim 5, further comprising: Obtain the motor vibration frequency and vehicle position and attitude of the electric grader; and After determining that the electric grader has detached from the obstacle based on the pressure change rate, the torque change rate, the motor vibration frequency, and the vehicle body position and attitude, the electric grader is controlled to return to the normal operation control mode.

13. A control device for an electric grader, comprising: Memory; as well as A processor coupled to the memory, the processor being configured to execute the control method as described in any one of claims 5 to 12 based on instructions stored in the memory.

14. An electric grader, comprising: The control device as described in claim 13.

15. A computer-readable storage medium having stored thereon computer instructions that, when executed by a processor, implement the control method as described in any one of claims 5 to 12.

16. A computer program product comprising a computer program or instructions that, when executed by a processor, implement the control method as described in any one of claims 5 to 12.

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