Motor control method and device, loader and readable storage medium

Abstract

The invention provides a motor control method and device, a loading machine and a readable storage medium, and is applied to the technical field of hydraulic pressure. The method comprises the steps that whether the state of the hydraulic system reaches a target state that pressure reaches a pressure upper limit and the actual rotating speed of a motor reaches a rotating speed upper limit or not is monitored, if yes, the state duration of the hydraulic system in the target state is obtained, and the actual rotating speed of the motor is reduced under the condition that the state duration reaches a preset duration so as to reduce the pressure of the hydraulic system. Thus, when the pressure of the hydraulic system is large and the motor runs for a long time at a large rotating speed, the actual rotating speed of the motor can be reduced in advance so as to prevent abnormal shutdown possibly occurring to the motor, and therefore the fault probability of the hydraulic system can be reduced, and the reliability of the hydraulic system can be improved.

Description

Technical Field

[0001] This application relates to the field of hydraulic technology, and more specifically, to a motor control method, apparatus, loader, and readable storage medium in the field of hydraulic technology. Background Technology

[0002] Electric motor-driven hydraulic systems are not only energy-efficient but also more environmentally friendly. The power source in this type of hydraulic system is the electric motor, which primarily drives the hydraulic pump.

[0003] Motors typically use speed control. When driving a hydraulic pump, if the motor continues to run at a high speed when the hydraulic system pressure is high, the hydraulic resistance in the hydraulic system will cause the hydraulic pump to generate a large resistance to the motor, resulting in a significant increase in the motor torque. When the motor torque increases significantly, the speed may drop significantly, which may cause a large speed deviation in the motor, leading to abnormal motor shutdown and potentially causing hydraulic system failure. Summary of the Invention

[0004] This application provides a motor control method, apparatus, loader, and readable storage medium, which can reduce the failure rate of hydraulic systems.

[0005] Firstly, a motor control method is provided, the method comprising:

[0006] Monitor whether the hydraulic system has reached a target state; wherein, the target state indicates that the pressure of the hydraulic system has reached the upper pressure limit and the actual speed of the motor has reached the upper speed limit, and the motor is used to drive the hydraulic pump in the hydraulic system to operate;

[0007] If so, then obtain the duration of the hydraulic system in the target state;

[0008] If the duration of the state reaches a preset duration, the actual speed of the motor is reduced to decrease the pressure of the hydraulic system.

[0009] In this embodiment, during the operation of the hydraulic system, the system monitors whether it has reached the target state where the pressure reaches the upper limit and the actual speed of the motor reaches the upper limit. If so, the duration of the hydraulic system in the target state is obtained. If the duration reaches a preset time, the actual speed of the motor is reduced to lower the pressure of the hydraulic system. This allows for pre-emptive reduction of the motor's actual speed when the hydraulic system pressure is high and the motor is running at a high speed for an extended period, preventing potential abnormal motor shutdowns and thus reducing the probability of hydraulic system failures and improving its reliability. A lower failure rate enhances the safety and reliability of the hydraulic system. Furthermore, preventing potential abnormal motor shutdowns reduces the probability of such shutdowns, minimizing damage to the motor and extending its lifespan.

[0010] In conjunction with the first aspect, in some possible implementations, reducing the actual speed of the motor includes: determining the target speed of the motor currently input; controlling the motor to operate alternately at the target speed and a first preset speed less than the upper limit of the speed, so as to reduce the average speed of the motor; or, controlling the actual speed gradient of the motor to decrease.

[0011] In this embodiment of the application, during the process of reducing the actual speed of the motor, the motor is controlled to alternate between a first preset speed and a target speed that is lower than the upper limit of the speed, or the actual speed of the motor is controlled to decrease gradually. This can avoid sudden pressure changes in the hydraulic system and thus reduce the failure rate of the hydraulic system.

[0012] In conjunction with the first aspect, in some possible implementations, controlling the actual speed gradient of the motor to decrease includes: if the target speed is less than the upper speed limit, and the current actual speed of the motor is greater than the target speed, then controlling the actual speed gradient of the motor to decrease to the target speed; or, if the target speed is less than the upper speed limit, and the current actual speed of the motor is less than or equal to the target speed, then controlling the motor to operate at the target speed; or, if the target speed is equal to the upper speed limit, controlling the actual speed gradient of the motor to decrease.

[0013] In conjunction with the first aspect, in some possible implementations, controlling the motor to operate at the target speed includes: determining the speed difference between the target speed and the current actual speed of the motor; if the speed difference is greater than a preset speed difference, controlling the actual speed of the motor to gradually increase to the target speed; or, if the speed difference is less than or equal to the preset speed difference, controlling the motor to switch from the current actual speed to the target speed.

[0014] In conjunction with the first aspect, in some possible implementations, the method further includes: if the target speed is equal to the upper speed limit when the actual speed of the motor drops to the lower speed limit, then controlling the motor to maintain the actual speed unchanged; or, if the target speed is less than the upper speed limit when the actual speed of the motor drops to the lower speed limit, then controlling the motor to run at the target speed.

[0015] In conjunction with the first aspect, in some possible implementations, controlling the actual speed gradient of the motor to decrease includes: controlling the motor to operate sequentially at each of a plurality of second preset speeds in a preset order until the actual speed of the motor reaches the minimum speed among the plurality of second preset speeds; wherein, in the preset order, the plurality of second preset speeds are ordered in descending order, and all of the plurality of second preset speeds are less than the upper limit of the speed.

[0016] In this embodiment, multiple different second preset speeds are set, and the motor is controlled to run at each second preset speed in descending order. This not only reduces the average speed of the motor and the pressure of the hydraulic system, but also avoids large changes in the speed of the motor in a short period of time, thereby avoiding large sudden changes in the pressure of the hydraulic system and reducing the failure rate of the hydraulic system.

[0017] In conjunction with the first aspect, in some possible implementations, there are multiple first preset speeds, and controlling the motor to alternately operate at the target speed and a first preset speed less than the upper limit of the speed includes: sorting the target speed and multiple first preset speeds in descending order to obtain a sorting result; cyclically executing a speed reduction step, in which the motor is controlled to operate at each speed in the sorting result in sequence.

[0018] In this embodiment, multiple different first preset speeds are set, and the motor is controlled to run at the speeds in descending order. This not only reduces the average speed of the motor and the pressure of the hydraulic system, but also avoids large changes in the speed of the motor in a short period of time, thereby avoiding large sudden changes in the pressure of the hydraulic system and reducing the failure rate of the hydraulic system.

[0019] Secondly, a motor control device is provided, the device comprising:

[0020] A monitoring module is used to monitor whether the state of the hydraulic system has reached a target state; wherein, the target state indicates that the pressure of the hydraulic system has reached the upper pressure limit and the actual speed of the motor has reached the upper speed limit, and the motor is used to drive the hydraulic pump in the hydraulic system to operate;

[0021] The acquisition module is used to acquire the duration of the hydraulic system being in the target state if the state of the hydraulic system reaches the target state.

[0022] The reduction module is used to reduce the actual speed of the motor when the state duration reaches a preset duration, so as to reduce the pressure of the hydraulic system.

[0023] Thirdly, a loader is provided, the loader comprising:

[0024] Memory, used to store executable program code;

[0025] A processor is configured to call and run the executable program code from the memory, causing the loader to perform the method in any possible implementation of the first aspect described above.

[0026] Fourthly, a motor control device program product is provided, the motor control device program product including: executable program code, which, when run on the motor control device, causes the motor control device to perform the method in any possible implementation of the first aspect.

[0027] Fifthly, a readable storage medium is provided that stores executable program code, which, when run on a motor control device, causes the motor control device to perform the method in any possible implementation of the first aspect described above. Attached Figure Description

[0028] Figure 1 This is a schematic diagram illustrating an application scenario of a motor control method provided in an embodiment of this application;

[0029] Figure 2 This is a flowchart illustrating the steps of a motor control method provided in an embodiment of this application;

[0030] Figure 3 This is a schematic diagram illustrating the principle of a motor control method provided in an embodiment of this application;

[0031] Figure 4 This is a schematic diagram of the structure of a motor control device provided in an embodiment of this application;

[0032] Figure 5 This is a structural schematic diagram of a loader provided in an embodiment of this application. Detailed Implementation

[0033] The technical solutions in this application will be clearly and thoroughly described below with reference to the accompanying drawings. In the description of the embodiments of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B. "And / or" in the text is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, in the description of the embodiments of this application, "multiple" refers to two or more than two.

[0034] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0035] See Figure 1 , Figure 1 This is a schematic diagram illustrating an application scenario of a motor control method provided in an embodiment of this application. The scenario includes an electric loader, whose hydraulic system includes a hydraulic pump driven by the superstructure motor within the electric loader.

[0036] like Figure 1 As shown, the electric loader also includes an operating handle, a Vehicle Control Unit (VCU), and a motor controller. The operating handle is connected to the VCU, allowing the user to input the target motor speed. For example, the opening of the operating handle can be set to be positively correlated with the target speed; the larger the opening of the operating handle, the higher the target speed input to the VCU. The VCU is connected to the motor controller, which in turn is connected to the superstructure motor. In the normal motor control process, the VCU sends the target speed to the motor controller, which then controls the motor to operate at the target speed.

[0037] The hydraulic system also includes a pressure sensor connected to the vehicle controller. The pressure sensor is located in the high-pressure oil circuit of the hydraulic system, and the vehicle controller can detect the pressure in the high-pressure oil circuit through the pressure sensor; this pressure is the hydraulic system pressure. It should be noted that the hydraulic system also includes other components such as hydraulic cylinders, oil tanks, directional valves, pressure relief valves, and filters, which will not be elaborated upon in this embodiment.

[0038] like Figure 1As shown, the vehicle controller controls the operation of the superstructure motor based on the target speed input by the operating handle. When the operating handle is fully open, the target speed reaches the motor's upper speed limit (also known as the maximum speed). At this point, the vehicle controller, through the motor controller, controls the motor to run at its maximum speed, ensuring the motor's actual speed reaches the maximum. In practical applications, users may continuously keep the operating handle at its maximum opening while controlling the hydraulic system, causing the motor to run continuously at its maximum speed.

[0039] During the operation of a hydraulic system, when the pressure is high, if the motor continues to run at its maximum speed, the hydraulic system may experience pressure buildup, resulting in significant hydraulic resistance. This high hydraulic resistance will cause the hydraulic pump to exert significant resistance on the motor, leading to a substantial increase in the motor's torque. When the motor's torque increases significantly, the actual speed may decrease significantly, which may cause a large speed deviation between the actual speed and the target speed. This could lead to abnormal motor shutdown and hydraulic system failure.

[0040] Furthermore, if the motor stops abnormally while the electric loader is loading or unloading heavy goods, it could lead to a safety accident. Moreover, an abnormal motor stop can also damage the motor and shorten its lifespan.

[0041] To address the aforementioned technical problems, this application provides a motor control method. In this method, during the operation of a hydraulic system, the pressure of the hydraulic system and the actual speed of the motor are monitored. When the pressure of the hydraulic system reaches a preset pressure limit and the actual speed of the motor reaches a preset speed limit, the motor is determined to enter a target state, and the duration of the motor in the target state is obtained. Subsequently, if the state duration reaches the preset duration, it is determined that the motor may abnormally stop. At this time, the actual speed of the motor is reduced to lower the pressure of the hydraulic system, thereby reducing the probability of abnormal motor stoppage. Thus, when the hydraulic system pressure is high and the motor speed is high, potential abnormal motor stoppage can be prevented, thereby reducing the failure rate of the hydraulic system and improving its reliability. A lower failure rate improves the safety and reliability of the hydraulic system. Simultaneously, a reduced probability of abnormal motor stoppage also reduces damage to the motor and extends its service life.

[0042] The upper limit of rotational speed can be the maximum rotational speed of the motor, or a speed value that is less than but close to the maximum rotational speed. The upper limit of pressure can be a pressure value that is less than but close to the maximum pressure of the hydraulic system, determined in advance through experiments. The preset duration can also be determined in advance through experiments. For example, during the testing phase of the hydraulic system, the pressure of the hydraulic system can be brought to the upper limit of pressure first. After the pressure reaches the upper limit of pressure, the motor is controlled to run at the upper limit of rotational speed (i.e., the maximum speed) and timing begins. During the timing process, the pressure of the hydraulic system is controlled to continue to reach the upper limit of pressure, and the motor is controlled to continue to run at the upper limit of rotational speed, until the motor abnormally stops due to a large speed deviation. The timing ends when the motor abnormally stops, and the timing duration is obtained. Then, the preset duration can be set to a duration value that is less than but close to the preset duration.

[0043] It should be understood that the motor control method provided in the embodiments of this application can be applied to... Figure 1 The scenario shown can also be applied to other scenarios. The methods for setting the pressure limit, speed limit, and preset duration can include, but are not limited to, the examples above.

[0044] See Figure 2 , Figure 2 This is a flowchart illustrating the steps of a motor control method provided in an embodiment of this application. The executing entity of this method can be a motor control device in a hydraulic system, for example... Figure 1 The VCU shown is as follows. Figure 2 As shown, the method may include the following steps:

[0045] Step 201: Monitor whether the hydraulic system has reached the target state.

[0046] Step 202: If the hydraulic system reaches the target state, then obtain the duration of the hydraulic system in the target state.

[0047] The target state indicates that the pressure of the hydraulic system has reached the upper pressure limit and the actual speed of the motor has reached the upper speed limit. The motor is used to drive the hydraulic pump in the hydraulic system.

[0048] like Figure 1As shown, after the hydraulic system in the electric loader is started, the VCU can periodically detect the pressure of the high-pressure oil circuit in the hydraulic system through sensors. When the detected pressure is greater than or equal to the preset pressure upper limit, it determines that the hydraulic system pressure has reached the pressure upper limit. Furthermore, after the hydraulic system in the electric loader is started, the user can control the opening degree of the operating handle according to actual needs to control the motor speed. The VCU can pre-store the mapping relationship between the operating handle opening degree and the target speed, ensuring a positive correlation between the opening degree and the target speed. After the hydraulic system is started, the VCU can periodically detect the opening degree of the operating handle and determine the target motor speed based on the detected opening degree and the pre-stored mapping relationship. For example, the mapping relationship between the operating handle opening degree and the target speed can be stored in a table. After detecting the operating handle opening degree, the target speed corresponding to the operating handle opening degree can be determined by looking up the table. After determining the target speed, the VCU can send the target speed to the motor controller, which can directly control the motor speed to achieve the target speed.

[0049] Optionally, after the VCU determines that the target speed is equal to the upper limit of the motor's speed (i.e., the maximum speed) based on the opening degree of the operating handle and sends the target speed to the motor controller, it determines that the actual speed of the motor has reached the maximum speed. Alternatively, the VCU can periodically detect the actual speed of the motor through a speed sensor, and determine that the actual speed of the motor has reached the upper limit when the detected speed is greater than or equal to the upper limit of the speed.

[0050] For example, when the pressure of the hydraulic system reaches the upper pressure limit and the actual speed of the motor reaches the upper speed limit, it can be determined that the hydraulic system has reached the target state, and timing can begin at this time. After timing begins, if the pressure of the hydraulic system is again detected to be lower than the upper pressure limit and / or the actual speed of the motor is detected to be lower than the upper speed limit, it is determined that the hydraulic system has exited the target state, and timing can end. The timing duration during the timing process is the duration of the hydraulic system in the target state.

[0051] Step 203: When the state duration reaches the preset duration, reduce the actual speed of the motor to reduce the pressure of the hydraulic system.

[0052] For example, during the timing process, the timing duration can be periodically compared with a preset duration. If the comparison determines that the timing duration has reached the preset duration, it can be determined that the hydraulic system pressure is high and the motor has been running at a high speed for an extended period, potentially leading to an abnormal shutdown. In this case, the actual motor speed can be controlled to decrease, thereby reducing the hydraulic system pressure. For instance, when the preset duration is reached, the VCU can send a preset safe speed to the motor controller. The safe speed can be a speed value that is less than but close to the upper speed limit. After receiving the safe speed, the motor controller controls the motor to run at the safe speed, reducing the actual motor speed to the safe speed. This keeps the actual motor speed below the upper speed limit, thereby reducing the hydraulic system pressure. When the hydraulic system pressure decreases, the probability of the motor abnormally shutting down decreases.

[0053] For example, multiple third preset speeds of different values ​​can be preset, all of which are less than and close to the upper speed limit. When the preset time period is reached, the VCU can alternately send each third preset speed to the motor controller. After receiving each third preset speed, the motor controller controls the motor to run at the received third preset speed. Since multiple third preset speeds are all less than the upper speed limit, the average speed of the motor can be lower than the upper speed limit, thereby reducing the pressure in the hydraulic system. It should be understood that the above is only an exemplary example, and specific methods for reducing the actual speed of the motor may include, but are not limited to, the examples above.

[0054] Optionally, during the reduction of the motor's actual speed, the pressure of the hydraulic system can be monitored in real time. When the hydraulic system pressure drops to a preset pressure threshold, the reduction of the motor's actual speed is stopped. At this point, a normal control procedure can be used, determining the target speed based on the opening of the operating handle and controlling the motor to run at the target speed.

[0055] During the timing process, if the hydraulic system pressure is detected to be lower than the upper pressure limit and / or the actual motor speed is detected to be lower than the upper speed limit before the preset timing duration is reached, the hydraulic system is determined to have exited the target state, and the timing can be terminated. After the timing ends, the motor can be controlled to operate based on the target speed obtained at the current moment, and the motor speed can be controlled using the normal control process.

[0056] In this embodiment, during the operation of the hydraulic system, the system monitors whether it has reached the target state where the pressure reaches the upper limit and the actual speed of the motor reaches the upper limit. If so, the duration of the hydraulic system in the target state is obtained. If the duration reaches a preset time, the actual speed of the motor is reduced to lower the pressure of the hydraulic system. This allows for pre-emptive reduction of the motor's actual speed when the hydraulic system pressure is high and the motor is running at a high speed for an extended period, preventing potential abnormal motor shutdowns and thus reducing the probability of hydraulic system failures and improving its reliability. A lower failure rate enhances the safety and reliability of the hydraulic system. Furthermore, preventing potential abnormal motor shutdowns reduces the probability of such shutdowns, minimizing damage to the motor and extending its lifespan.

[0057] Optionally, reducing the actual speed of the motor includes:

[0058] Determine the target rotational speed for the current input;

[0059] The motor is controlled to alternate between operating at the target speed and a first preset speed below the upper limit of the speed, in order to reduce the average speed of the motor;

[0060] Alternatively, control the actual speed gradient of the motor to decrease.

[0061] In one implementation, during the process of reducing the actual speed of the motor, the currently input target speed can be detected, and then the motor operation can be controlled according to the target speed and a first preset speed to reduce the average speed of the motor. For example, during the process of controlling the actual speed of the motor to decrease, the VCU can continue to periodically detect the opening degree of the operating handle and determine the target speed at the current moment based on the detected opening degree. Then, the first preset speed can be sent to the motor controller, which can control the motor to run at the first preset speed for a first duration. After the first duration, the VCU can send the current target speed to the motor controller, which can control the motor to run at the current target speed for a second duration, which can be less than or equal to the first duration. Then, the first preset speed can be sent to the motor controller again, controlling the motor to run at the first preset speed for a first duration. After the motor runs at the first preset speed for a first duration, the current target speed can be sent to the motor controller again, controlling the motor to run at the target speed for a second duration. This process can be repeated in a similar manner, allowing the motor to alternate between the first preset speed and the target speed, thereby reducing the average speed of the motor.

[0062] Alternatively, the target speed at the current moment can be sent to the motor controller first, controlling the motor to run at the target speed for a second duration. After the second duration, a first preset speed can be sent to the motor controller, controlling the motor to run at the first preset speed for a first duration. Then, the target speed at the current moment can be sent to the motor controller again, controlling the motor to run at the target speed for a second duration. After the motor runs at the target speed for a second duration, the first preset speed can be sent to the motor controller again, controlling the motor to run at the first preset speed for a first duration. This process can be repeated in a cyclical manner to control the motor to alternate between the first preset speed and the target speed at the current moment.

[0063] Since the first preset speed is less than the upper limit of speed, when the control motor runs alternately at the target speed and the preset speed, the average speed of the motor will decrease, which will in turn cause the pressure of the hydraulic system to decrease. When the pressure of the hydraulic system decreases, the hydraulic resistance will decrease, which can alleviate the resistance of the hydraulic system to the motor, thereby reducing the probability of abnormal motor shutdown and reducing the failure rate of the hydraulic system.

[0064] In practical applications, the first preset speed, the first duration, and the second duration can be determined experimentally. By having the motor run at the first preset speed and the actual speed alternately, the pressure of the hydraulic system can be reduced, the resistance of the hydraulic system to the motor can be alleviated, and the probability of abnormal motor shutdown can be reduced.

[0065] Optionally, during the process of controlling the motor to run alternately at the target speed and the first preset speed, the pressure of the hydraulic system can be detected in real time. When the pressure of the hydraulic system drops to the preset pressure threshold, the normal control process can be adopted, and the target speed can be determined according to the opening of the operating handle to control the motor to run at the target speed.

[0066] In another embodiment, during the reduction of the motor's actual speed, the actual speed can be controlled to decrease gradually. For example, the decrease magnitude and step size can be preset, where the decrease magnitude is the amount of time the actual speed decreases each time, and the step size is the interval between two consecutive decreases. For example, the decrease magnitude can be set to 3 revolutions per minute (RPM), and the step size to 100 milliseconds. When starting to reduce the motor's actual speed, starting from the upper speed limit, the actual speed can be controlled to decrease by 3 RPM every 100 seconds. Specifically, after starting to reduce the motor's actual speed, the VCU first sends a speed of N-3 (N being the upper speed limit) to the motor controller, controlling the motor to run at an actual speed of N-3 for 100 milliseconds; after a 100-millisecond interval, it sends a speed of N-6 to the motor controller, controlling the motor to run at an actual speed of N-6 for 100 milliseconds, and so on. Each time the speed sent to the motor controller decreases by 3 RPM, the actual speed of the motor can be controlled to decrease gradually by 3 RPM.

[0067] Alternatively, after starting to reduce the actual motor speed, instead of using the opening of the control handle to determine the target speed, other methods can be used to determine the target speed, causing the target speed gradient to decrease, and thus the actual motor speed gradient to decrease. For example, after starting to reduce the actual motor speed, a hysteresis algorithm can be used to determine the target speed. The target speed determined by the hysteresis algorithm decreases by 3 revolutions per minute every 100 milliseconds. When controlling the motor operation according to this target speed, the actual motor speed can be controlled to decrease by 3 revolutions per minute every 100 milliseconds.

[0068] Optionally, during the process of controlling the actual speed gradient decrease of the motor, the pressure of the hydraulic system can be detected in real time. When the pressure of the hydraulic system drops to the preset pressure threshold, the normal control process can be adopted, and the target speed can be determined according to the opening of the operating handle to control the motor to run at the target speed.

[0069] In practical applications, the descent amplitude and descent step size can be set to smaller values ​​to control the actual speed of the motor to decrease slowly, avoiding a large drop in the pressure of the hydraulic system at one time, thereby reducing the failure rate of the hydraulic system.

[0070] In this embodiment of the application, during the process of reducing the actual speed of the motor, the motor is controlled to alternate between a first preset speed and a target speed that is lower than the upper limit of the speed, or the actual speed of the motor is controlled to decrease gradually. This can avoid sudden pressure changes in the hydraulic system and thus reduce the failure rate of the hydraulic system.

[0071] Optionally, controlling the actual speed gradient of the motor to decrease includes:

[0072] If the target speed is less than the upper speed limit, and the current actual speed of the motor is greater than the target speed, then the actual speed of the motor is controlled to gradually decrease to the target speed.

[0073] Alternatively, if the target speed is less than the upper speed limit, and the current actual speed of the motor is less than or equal to the target speed, then the motor is controlled to run at the target speed.

[0074] Alternatively, when the target speed equals the upper speed limit, the actual speed gradient of the motor can be controlled to decrease.

[0075] For example, during the process of controlling the actual speed gradient decrease of the motor, the VCU can continue to periodically detect the opening degree of the operating handle and determine the target speed at the current moment based on the detected opening degree. Simultaneously, the VCU can detect the actual speed of the motor, and after each time it sends a speed (which can be a preset speed or a target speed) to the motor controller, it can determine the sent speed as the actual speed of the motor. Alternatively, the actual speed of the motor at the current moment can be obtained by detecting the motor speed using a speed sensor.

[0076] After obtaining the target speed at the current moment, it can be compared with the upper speed limit. If the target speed is less than the upper speed limit, it can be determined that the user has adjusted the opening of the control handle, and the current opening of the control handle is less than the maximum opening. In this case, controlling the motor to run according to the target speed corresponding to the current opening will likely prevent the motor from stopping abnormally. Further, the actual speed at the current moment is compared with the target speed. If the actual speed of the motor at the current moment is greater than the target speed, the actual speed of the motor can be controlled to gradually decrease from the current actual speed to the target speed. Afterwards, the normal control process can be adopted, determining the target speed through the opening of the control handle, and controlling the motor to run at the target speed.

[0077] Similarly, after obtaining the target speed at the current moment, it can be compared with the upper speed limit. If the target speed is less than the upper speed limit, it can be determined that the user has adjusted the opening of the control handle, and the current opening of the control handle is less than the maximum opening. In this case, controlling the motor to run according to the target speed corresponding to the current opening will likely prevent the motor from stopping abnormally. Furthermore, comparing the actual speed at the current moment with the target speed, if the actual speed at the current moment is less than or equal to the target speed, the motor can be controlled to run at the target speed. Afterwards, the normal control flow can be adopted, determining the target speed through the opening of the control handle and controlling the motor to run at the target speed. This allows the motor control flow to quickly return to the normal control flow.

[0078] Furthermore, after obtaining the target speed at the current moment, if the target speed is equal to the upper limit of the speed, it can be determined that the user has not adjusted the opening of the operating handle, and the current opening of the operating handle is still the maximum opening. At this time, the motor cannot be controlled according to the target speed at the current moment. Instead, the actual speed gradient of the motor can be controlled to decrease, so as to reduce the probability of abnormal motor shutdown.

[0079] Optionally, controlling the motor to operate at a target speed includes:

[0080] Determine the speed difference between the target speed and the motor's current actual speed;

[0081] When the speed difference is greater than the preset speed difference, the actual speed gradient of the motor is controlled to rise to the target speed;

[0082] Alternatively, if the speed difference is less than or equal to the preset speed difference, the motor can be controlled to switch from the current actual speed to the target speed.

[0083] In one implementation, during the process of controlling the actual speed gradient decrease of the motor, after obtaining the target speed at the current moment, if the target speed is less than the upper speed limit, and the actual speed of the motor at the current moment is less than or equal to the target speed, the speed difference between the target speed and the actual speed can be determined. If the speed difference is greater than a preset speed difference, it is determined that the difference between the target speed and the actual speed at the current moment is large. The actual speed of the motor can then be controlled to increase from the current actual speed gradient to the target speed to avoid large changes in the actual speed of the motor in a short period of time. This can prevent sudden changes in the pressure of the hydraulic system and reduce the failure rate of the hydraulic system.

[0084] Conversely, if the speed difference is less than or equal to the preset speed difference, and the difference between the target speed and the actual speed is small, the motor can be directly controlled to switch from the actual speed at the current moment to the target speed at the current moment, so as to quickly restore the normal control process of the motor.

[0085] Optionally, the method may further include:

[0086] If the target speed is equal to the upper speed limit when the actual speed of the motor drops to the lower speed limit, then the motor will be controlled to maintain the actual speed unchanged.

[0087] Alternatively, if the target speed is less than the upper speed limit when the actual speed of the motor drops to the lower speed limit, the motor can be controlled to run at the target speed.

[0088] For example, during the process of reducing the actual speed of the motor, when it is detected that the actual speed of the motor at the current moment is less than or equal to the preset lower speed limit, the target speed at the current moment can be compared with the upper speed limit. If the target speed is equal to the upper speed limit, it is determined that the target speed cannot be used to control the motor to run at this time, and the motor can be controlled to run at the actual speed at the current moment to keep the actual speed of the motor unchanged.

[0089] Conversely, if the actual motor speed at the current moment is detected to be less than or equal to the preset lower speed limit, and the target speed at the current moment is less than the upper speed limit, then it is determined that the motor can be controlled to run at the target speed at the current moment, and the motor can be directly controlled to run at the target speed at the current moment to quickly restore normal motor control. Alternatively, if the speed difference between the target speed and the actual speed at the current moment is large, the actual speed of the motor can be controlled to gradually increase to the target speed at the current moment, or gradually decrease to the target speed at the current moment. Afterwards, the normal control process can be used, and the target speed can be determined by the opening of the operating handle to control the motor to run at the target speed.

[0090] Optionally, the step of reducing the actual speed of the motor also includes:

[0091] According to a preset sequence, the motor is controlled to run at each of the multiple second preset speeds in turn until the actual speed of the motor reaches the minimum speed among the multiple second preset speeds; wherein, in the preset sequence, the multiple second preset speeds are arranged in descending order, and all of the multiple second preset speeds are less than the upper limit of the speed.

[0092] In one implementation, multiple second preset speeds lower than the upper speed limit can be preset, and these second preset speeds can be sorted in descending order to obtain a preset sequence. During the actual speed gradient decrease of the controlled motor, the motor can be controlled to run at the first speed in the preset sequence (i.e., the largest second preset speed), then at the second speed, and so on, sequentially controlling the motor to run at each speed in the preset sequence. During the sequential operation of the motor at each speed in the preset sequence, when the pressure of the hydraulic system drops to a preset pressure threshold, a normal control procedure can be adopted, determining the target speed based on the opening of the operating handle, and controlling the motor to run at the target speed.

[0093] Alternatively, after the control motor runs at the last speed in the preset sequence (i.e., the minimum second preset speed), the control motor continues to run at the last speed until the hydraulic system pressure drops to a preset pressure threshold. Once the hydraulic system pressure drops to the preset pressure threshold, the normal control procedure can be used, determining the target speed based on the opening of the operating handle, and controlling the motor to run at the target speed.

[0094] In this embodiment, multiple different second preset speeds are set, and the motor is controlled to run at each second preset speed in descending order. This not only reduces the average speed of the motor and the pressure of the hydraulic system, but also avoids large changes in the speed of the motor in a short period of time, thereby avoiding large sudden changes in the pressure of the hydraulic system and reducing the failure rate of the hydraulic system.

[0095] Optionally, there are multiple first preset speeds, and the motor is controlled to alternate between a target speed and a first preset speed less than the upper limit of the speed, including:

[0096] The target speed and multiple first preset speeds are sorted in descending order to obtain the sorting result;

[0097] The deceleration step is executed cyclically, in which the motor is controlled to run at each speed in the sorted result in turn.

[0098] For example, M different first preset speeds can be set, all of which are less than the upper speed limit. During the process of controlling the motor to alternate between the first preset speed and the target speed, the target speed at the current moment can first be determined based on the opening of the operating handle. Then, the M first preset speeds and the target speed can be sorted in descending order to obtain a sorting result. After obtaining the sorting result, a speed reduction step can be executed cyclically. During each speed reduction step, according to the sorting result, the motor is first controlled to run at the first speed in the sorting result (the first speed is the maximum speed in the sorting result), then the motor is controlled to run at the second speed in the sorting result, and so on, controlling the motor to run at each speed in the sorting result sequentially. After the motor runs at the (M+1)th speed in the sorting result (i.e., the last speed), the speed reduction step is executed again, starting from the first speed in the sorting result and controlling the motor to run at each speed in the sorting result sequentially. During the cyclic execution of the speed reduction step, when the pressure of the hydraulic system drops to a preset pressure threshold, the actual speed reduction of the motor stops. At this point, the normal control procedure can be adopted, and the target speed can be determined according to the opening degree of the operating handle, and the motor can be controlled to run at the target speed.

[0099] In this embodiment, multiple different first preset speeds are set, and the motor is controlled to run at the speeds in descending order. This not only reduces the average speed of the motor and the pressure of the hydraulic system, but also avoids large changes in the speed of the motor in a short period of time, thereby avoiding large sudden changes in the pressure of the hydraulic system and reducing the failure rate of the hydraulic system.

[0100] Optionally, during the process of controlling the actual speed of the motor to decrease, the actual speed of the motor is controlled to be no lower than the idle speed of the motor. For example, during the process of controlling the actual speed of the motor to decrease, the VCU can compare the sent speed with the idle speed each time it sends a speed to the motor controller. If the sent speed is less than the idle speed, the VCU sends the idle speed to the motor controller, so that the motor controller controls the motor to run at idle speed.

[0101] See Figure 3 , Figure 3 This is a schematic diagram illustrating the principle of a motor control method provided in an embodiment of this application. Figure 3 As shown, the motor control device includes software modules such as a first comparator, a second comparator, an AND gate, a limiter, and a selector. The first target speed is the target speed corresponding to the opening degree of the operating handle, the second target speed is the speed after each preset decrease in the actual speed of the controlled motor during the gradient descent process, and the real-time pressure is the pressure of the hydraulic system monitored at the current moment.

[0102] During the operation of the hydraulic system, the first comparator acquires the real-time pressure of the hydraulic system and compares it with the upper pressure limit. When the real-time pressure is greater than or equal to the upper pressure limit, it inputs a flag of 1 to the AND gate; when the real-time pressure is less than the upper pressure limit, it inputs a flag of 0 to the AND gate. The second comparator acquires the actual speed of the motor in real time and compares it with the upper speed limit. When the real-time speed is greater than or equal to the upper speed limit, it inputs a flag of 1 to the AND gate; when the real-time speed is less than the upper speed limit, it inputs a flag of 0 to the AND gate. The AND gate performs a bitwise AND operation on the flags output by the first and second comparators. When the result of the AND operation is 1 and the duration exceeds a preset duration, it outputs a flag of 1 to the selector; when the result of the AND operation is 0, it outputs a flag of 0 to the selector. It can be understood that when the AND gate outputs a flag of 1, the hydraulic system is in the target state; when the AND gate outputs a flag of 0, the hydraulic system is not in the target state.

[0103] When the received flag bit is 0, the selector selects the first target speed to control the motor, and the actual speed of the controlled motor is the first target speed. When the received flag bit is 1, the selector selects the third target speed output by the limiter to control the motor.

[0104] Specifically, when the flag bit of the AND gate output is 1, the limiter determines the second target speed based on the actual speed of the motor at the current moment. The second target speed is obtained by reducing the actual speed at the current moment by a preset amount each time. At the same time, the limiter determines the third target speed based on the second target speed, the upper speed limit, and the lower speed limit. The third target speed is less than the upper speed limit and greater than the lower speed limit, which can be the motor's idle speed.

[0105] The first comparator can also compare the real-time pressure with the lower pressure limit. During the process of reducing the actual speed of the motor, when the real-time pressure is less than or equal to the lower pressure limit, the first comparator outputs a 0 flag. This flag is used to make the AND gate output a 0 flag, thereby enabling the selector to select the first target speed to control the motor operation.

[0106] See Figure 4 , Figure 4 This is a schematic diagram of the structure of a motor control device provided in an embodiment of this application. Figure 4 As shown, the motor control device 400 may include:

[0107] The monitoring module 401 is used to monitor whether the state of the hydraulic system has reached the target state; wherein, the target state indicates that the pressure of the hydraulic system has reached the upper pressure limit and the actual speed of the motor has reached the upper speed limit, and the motor is used to drive the hydraulic pump in the hydraulic system to run;

[0108] The acquisition module 402 is used to acquire the duration of the hydraulic system being in the target state if the state of the hydraulic system reaches the target state.

[0109] The reduction module 403 is used to reduce the actual speed of the motor when the state duration reaches a preset duration, so as to reduce the pressure of the hydraulic system.

[0110] Optionally, reducing the actual speed of the motor includes: determining the target speed of the motor currently input; controlling the motor to operate alternately at the target speed and a first preset speed less than the upper limit of the speed, so as to reduce the average speed of the motor; or, controlling the actual speed gradient of the motor to decrease.

[0111] Optionally, the reduction module 403 is specifically configured to, when the target speed is less than the upper speed limit, control the actual speed of the motor to decrease to the target speed if the current actual speed of the motor is greater than the target speed; or, when the target speed is less than the upper speed limit, control the motor to run at the target speed if the current actual speed of the motor is less than or equal to the target speed; or, when the target speed is equal to the upper speed limit, control the actual speed of the motor to decrease.

[0112] Optionally, the reduction module 403 is specifically used to determine the speed difference between the target speed and the current actual speed of the motor; if the speed difference is greater than a preset speed difference, control the actual speed gradient of the motor to rise to the target speed; or, if the speed difference is less than or equal to the preset speed difference, control the motor to switch from the current actual speed to the target speed.

[0113] Optionally, the reduction module 403 is further configured to, when the actual speed of the motor drops to the lower speed limit, if the target speed is equal to the upper speed limit, control the motor to maintain the actual speed unchanged; or, when the actual speed of the motor drops to the lower speed limit, if the target speed is less than the upper speed limit, control the motor to run at the target speed.

[0114] Optionally, the reduction module 403 is specifically used to control the motor to operate sequentially at each of a plurality of second preset speeds in a preset order until the actual speed of the motor reaches the minimum speed among the plurality of second preset speeds; wherein, in the preset order, the plurality of second preset speeds are arranged in descending order, and all of the plurality of second preset speeds are less than the upper limit of the speed.

[0115] Optionally, there are multiple first preset speeds, and the reduction module 403 is specifically used to sort the target speed and multiple first preset speeds in descending order to obtain a sorting result; and to perform the speed reduction step cyclically, wherein in the speed reduction step, the motor is controlled to run at each speed in the sorting result in sequence.

[0116] See Figure 5 , Figure 5 This is a structural schematic diagram of a loader provided in an embodiment of this application. Figure 5 As shown, the loader 500 includes a memory 501 and a processor 502. The memory 501 stores executable program code 5011, and the processor 502 is used to call and execute the executable program code 5011 to perform a motor control method.

[0117] Furthermore, embodiments of this application also protect a motor control device, which may include a memory and a processor, wherein the memory stores executable program code, and the processor is used to call and execute the executable program code to perform a motor control method provided in embodiments of this application.

[0118] This embodiment can divide the device into functional modules according to the above method example, or it can integrate two or more functions into one processing module. The integrated module can be implemented in hardware. It should be noted that the module division in this embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods.

[0119] When the functional modules are divided according to their respective functions, the device may also include a determining module, a replacing module, and a controlling module. It should be noted that all relevant content regarding the steps involved in the above method embodiments can be referenced to the functional descriptions of the corresponding functional modules, and will not be repeated here.

[0120] It should be understood that the device provided in this embodiment is used to execute the above-described motor control method, and therefore can achieve the same effect as the above-described implementation method.

[0121] When using an integrated unit, the device may include a determining module and an adjusting module. When applied to a loader, the processing module can be used to control and manage the loader's movements. The storage module can be used to support the loader in executing relevant program code, etc.

[0122] The processing module can be a processor or a vehicle body module, which can implement or execute various exemplary logic blocks, modules, and circuits shown in conjunction with the disclosure of this application. The processor can also be a combination of functions that implement computing capabilities, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and a microprocessor, etc., and the storage module can be a memory.

[0123] This embodiment also provides a readable storage medium storing executable program code. When the executable program code is run on the motor control device, the motor control device performs the above-mentioned related method steps to implement the motor control method provided in the above embodiment.

[0124] This embodiment also provides a motor control device program product. When the motor control device program product is run on the motor control device, the motor control device performs the above-mentioned related steps to realize the motor control method provided in the above embodiment.

[0125] In this embodiment, the device, readable storage medium, motor control device program product or chip are all used to execute the corresponding methods provided above. Therefore, the beneficial effects that can be achieved can be referred to the beneficial effects in the corresponding methods provided above, and will not be repeated here.

[0126] Through the above description of the embodiments, those skilled in the art will understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0127] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0128] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A motor control method, characterized in that, The method includes: Monitor whether the hydraulic system has reached a target state; wherein, the target state indicates that the pressure of the hydraulic system has reached the upper pressure limit and the actual speed of the motor has reached the upper speed limit, and the motor is used to drive the hydraulic pump in the hydraulic system to operate; If so, then obtain the duration of the hydraulic system in the target state; When the duration of the state reaches a preset duration, the actual speed of the motor is reduced to reduce the pressure of the hydraulic system.

2. The method as described in claim 1, characterized in that, The reduction of the actual speed of the motor includes: Determine the target speed of the motor currently input; The motor is controlled to operate alternately at the target speed and a first preset speed lower than the upper limit of the speed, so as to reduce the average speed of the motor; Alternatively, the actual speed gradient of the motor can be controlled to decrease.

3. The method as described in claim 2, characterized in that, The control of the actual speed gradient decrease of the motor includes: If the target speed is less than the upper speed limit, and the current actual speed of the motor is greater than the target speed, then the actual speed of the motor is controlled to gradually decrease to the target speed. Alternatively, if the target speed is less than the upper speed limit, and the current actual speed of the motor is less than or equal to the target speed, then the motor is controlled to run at the target speed. Alternatively, if the target speed is equal to the upper speed limit, the actual speed gradient of the motor is controlled to decrease.

4. The method as described in claim 3, characterized in that, Controlling the motor to operate at the target speed includes: Determine the speed difference between the target speed and the current actual speed of the motor; When the speed difference is greater than the preset speed difference, the actual speed gradient of the motor is controlled to increase to the target speed; Alternatively, if the speed difference is less than or equal to the preset speed difference, the motor is controlled to switch from the current actual speed to the target speed.

5. The method as described in claim 3, characterized in that, The method further includes: If the target speed is equal to the upper speed limit when the actual speed of the motor drops to the lower speed limit, then the motor is controlled to maintain the actual speed unchanged. Alternatively, if the actual speed of the motor drops to the lower speed limit, and the target speed is less than the upper speed limit, then the motor is controlled to run at the target speed.

6. The method according to any one of claims 2-5, characterized in that, The control of the actual speed gradient decrease of the motor includes: According to a preset sequence, the motor is controlled to run at each of a plurality of second preset speeds in sequence until the actual speed of the motor reaches the minimum speed among the plurality of second preset speeds; wherein, in the preset sequence, the plurality of second preset speeds are arranged in descending order, and all of the plurality of second preset speeds are less than the upper limit of the speed.

7. The method as described in claim 2, characterized in that, The first preset speed can be multiple, and controlling the motor to alternate between the target speed and a first preset speed less than the upper limit of the speed includes: The target rotational speed and multiple first preset rotational speeds are sorted in descending order to obtain the sorting result; The deceleration step is executed cyclically, in which the motor is controlled to run at each speed in the sorting result in sequence.

8. A motor control device, characterized in that, The device includes: A monitoring module is used to monitor whether the state of the hydraulic system has reached a target state; wherein, the target state indicates that the pressure of the hydraulic system has reached the upper pressure limit and the actual speed of the motor has reached the upper speed limit, and the motor is used to drive the hydraulic pump in the hydraulic system to operate; The acquisition module is used to acquire the duration of the hydraulic system being in the target state if the state of the hydraulic system reaches the target state. The reduction module is used to reduce the actual speed of the motor when the state duration reaches a preset duration, so as to reduce the pressure of the hydraulic system.

9. A loader, characterized in that, The loader includes: Memory, used to store executable program code; A processor for calling and running the executable program code from the memory, causing the loader to perform the method as described in any one of claims 1 to 7.

10. A readable storage medium, characterized in that, The readable storage medium stores executable program code that, when executed on the motor control device, causes the motor control device to perform the method as described in any one of claims 1 to 7.

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