Self-protection control method of electric driving system, electronic equipment and vehicle

Abstract

The invention provides a self-protection control method of an electric drive system, electronic equipment and a vehicle, and belongs to the technical field of vehicles, when protection control conditions are met, a counter is assigned to be a preset first count value, and a function protection flag bit is assigned to be a default starting parameter value; and the default maximum available torque of the motor is reduced to the preset safe maximum available torque according to the preset first adjustment duration. If the protection control condition is met, the vehicle runs on the bad road in a high-speed and large-torque state, the self-protection function is started by assigning a counter as a preset first count value and assigning a function protection flag bit as a default starting parameter value, the impact stress is reduced by reducing the upper limit of the request torque, the risk of damage to shaft teeth is reduced, and the service life of the vehicle is prolonged. The safety of the electric driving system is guaranteed, meanwhile, torque adjustment is conducted through the first adjustment duration, the smoothness of torque adjustment is guaranteed, and better driving experience is brought to a user.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and in particular to a self-protection control method of an electric drive system, an electronic device and a vehicle. Background Art

[0002] The electric drive system is an important component of new energy vehicles. When the vehicle continuously accelerates through continuous bad roads (such as washboard roads, Belgian roads, bumpy roads, etc.), the wheel-end load of the vehicle will fluctuate violently. The impact caused by the fluctuation will be transmitted to the shaft teeth of the electric drive system. In extreme cases, the impact stress may exceed the yield strength that the shaft tooth material can withstand, causing damage to the shaft teeth and making the vehicle unable to drive normally. Summary of the invention

[0003] In view of this, the purpose of the present application is to propose a self-protection control method of an electric drive system, an electronic device and a vehicle, which are used to protect the electric drive system under bad road conditions.

[0004] Based on the above purpose, the present application provides a self-protection control method for an electric drive system, comprising: Acquiring vehicle operating parameters according to a preset execution cycle, and determining whether a protection control condition is satisfied according to the vehicle operating parameters of two adjacent execution cycles; In response to satisfying the protection control condition, assigning a counter to a preset first count value, and assigning a function protection flag to a default startup parameter value; In response to the value of the function protection flag being the default startup parameter value, the default maximum available torque of the motor is reduced to a preset safe maximum available torque according to a preset first adjustment duration.

[0005] Optionally, the self-protection control method of the electric drive system further includes: In response to the protection control condition not being satisfied, determining a current count value of the counter; In response to the current count value being greater than zero, the current count value is cumulatively decremented once to obtain an updated count value; In response to the updated count value being greater than a zero value, limiting the requested torque of the motor according to a safety upper limit torque; In response to the update count value being equal to zero, the value of the function protection flag is assigned to a shutdown parameter value, and the safe maximum available torque of the motor is restored to the default maximum available torque according to a preset second adjustment duration.

[0006] The torque limit will be cancelled only when it is continuously determined that the protection control conditions are not met, realizing the control strategy of counting delay exit, avoiding frequent switching between the safe maximum available torque and the default maximum available torque, and ensuring the smoothness of the self-protection control process. The control strategy of counting delay exit can avoid the use of too many parameters for control, improve control efficiency, and when the delayed exit control is interrupted, it is also only necessary to change the count value of the counter, and always use the count value of the counter to control exit and start, which is simple and efficient, avoiding the need for repeated timing and clearing of the timing duration when using time for delay control, and saving the cost of the timer in hardware.

[0007] Optionally, after limiting the requested torque of the motor according to the safety upper limit torque, the method further includes: Determine new conditional judgment results; In response to the new condition judgment result being that the protection control condition is satisfied, restoring the update count value to the first count value; In response to the new condition judgment result being that the protection control condition is not satisfied, the update count value is cumulatively decremented once.

[0008] Before the count value of the counter is reduced to the closing parameter value, if the protection control condition is met, the count value of the counter is reassigned to the first count value to ensure that the self-protection function continues to be executed, avoid the self-protection function from exiting due to accidental misjudgment, reduce the risk of damage to the gear shaft, so as to protect the safety of the electric drive system, and when it is determined again that the protection control condition is not met, the first count value is reduced by one, and the delayed exit control is restarted.

[0009] Optionally, the two adjacent execution cycles include a previous execution cycle and a subsequent execution cycle; and determining whether the protection control condition is met according to the vehicle operation parameters of the two adjacent execution cycles includes: determining whether a speed protection condition is met according to a previous motor speed in the vehicle operating parameters of the previous execution cycle and a subsequent motor speed in the vehicle operating parameters of the subsequent execution cycle; determining whether a vehicle speed protection condition is satisfied according to a previous detected vehicle speed in the vehicle operating parameters of the previous execution cycle and a subsequent detected vehicle speed in the vehicle operating parameters of the subsequent execution cycle; determining whether a torque protection condition is satisfied according to a previous output torque in the vehicle operating parameters of the previous execution cycle and a subsequent output torque in the vehicle operating parameters of the subsequent execution cycle; In response to simultaneously satisfying the rotation speed protection condition, the vehicle speed protection condition, and the torque protection condition, determining that the protection control condition is satisfied; In response to a condition among the rotation speed protection condition, the vehicle speed protection condition, and the torque protection condition being not satisfied, it is determined that the protection control condition is not satisfied.

[0010] Only when the speed protection condition, vehicle speed protection condition and torque protection condition are met at the same time can it be determined that the protection control condition is met. Different sub-conditions verify each other to avoid the contingency caused by a single judgment condition.

[0011] Optionally, the previous motor speed includes a detected previous motor actual speed and a previous calculated speed calculated according to vehicle operating parameters, and the next motor speed includes a detected next motor actual speed and a next calculated speed calculated according to vehicle operating parameters; determining whether the speed protection condition is met according to the previous motor speed in the vehicle operating parameters of the previous execution cycle and the next motor speed in the vehicle operating parameters of the next execution cycle includes: Determine a speed difference between the actual speed of the previous motor and the actual speed of the next motor, and determine whether a cross-cycle speed condition is met according to the speed difference; Determine a previous speed error value between the previous motor actual speed and the previous calculated speed, and a subsequent speed error value between the subsequent motor actual speed and the subsequent calculated speed, and determine whether the same-cycle speed condition is met according to the previous speed error value and the subsequent speed error value; In response to simultaneously satisfying the inter-cycle speed condition and the same-cycle speed condition, determining that the speed protection condition is satisfied; In response to a condition between the inter-cycle speed condition and the same-cycle speed condition not being met, it is determined that the speed protection condition is not met.

[0012] The previous motor actual speed and the next motor actual speed are the measured values ​​of the motor output and transmission input ends, the previous calculated speed and the next calculated speed are the calculated values ​​determined based on the transmission output end, and the same-cycle speed condition is to determine whether the vehicle is driving on a bad road based on the difference between the calculated value and the measured value. The cross-cycle speed condition is to determine whether the vehicle is driving on a bad road based on the difference in the measured values ​​between two adjacent execution cycles. By mutual verification between the cross-cycle speed condition and the same-cycle speed condition, the contingency caused by a single judgment condition is avoided, the accuracy of risk judgment based on the speed protection condition is improved, and the erroneous start of self-protection control is avoided.

[0013] Optionally, determining whether the vehicle speed protection condition is met according to a previous detected vehicle speed in the vehicle operating parameters of the previous execution cycle and a subsequent detected vehicle speed in the vehicle operating parameters of the subsequent execution cycle includes: In response to the previous detected vehicle speed being greater than or equal to a preset vehicle speed threshold, and the next detected vehicle speed being greater than or equal to a preset vehicle speed threshold, determining that the vehicle speed protection condition is satisfied; In response to the previous detected vehicle speed being less than a preset vehicle speed threshold, and / or the next detected vehicle speed being less than a preset vehicle speed threshold, it is determined that the vehicle speed protection condition is not satisfied.

[0014] The speed protection condition requires that the detected vehicle speed within the execution cycle is greater than or equal to the preset speed threshold. This is because when driving at low speeds, even when driving on bad roads, the pressure between the transmission shaft teeth of the electric drive system is naturally smaller due to the slow speed and less bumps on bad roads. Within the tolerance range of the shaft teeth, no obvious damage will occur to the shaft teeth. Therefore, the self-protection function of the electric drive system needs to be turned on only when driving at high speeds. In order to avoid contingency, the speed of multiple consecutive execution cycles must be greater than the preset speed threshold to meet the speed protection condition, thereby reducing the contingency of the judgment process.

[0015] Optionally, determining whether the torque protection condition is satisfied according to a previous output torque in the vehicle operating parameters of the previous execution cycle and a subsequent output torque in the vehicle operating parameters of the subsequent execution cycle includes: In response to the previous output torque being greater than or equal to a preset torque threshold, and the next output torque being greater than or equal to a preset torque threshold, determining that the torque protection condition is satisfied; In response to the previous output torque being less than a preset torque threshold, and / or the next output torque being less than a preset torque threshold, it is determined that the torque protection condition is not satisfied.

[0016] The torque protection condition requires that the output torque within the execution cycle is greater than or equal to the preset torque threshold. This is because when the vehicle is driving at a low torque, even if it is driving on a bad road, the output torque is small. Even if the impact of driving on a bad road will increase the torque between the shaft teeth, the increased torque is still within the tolerance range of the shaft tooth material and will not cause significant damage to the structure and life of the shaft teeth. Only when a large torque is output, the transmission torque between the shaft teeth is already very large. After the torque generated by the superimposed impact, it may exceed the limit that the shaft tooth material can withstand, causing irreversible damage to the shaft teeth. Therefore, the self-protection function of the electric drive system needs to be turned on only when driving at a high torque. In order to avoid contingency, the output torque of multiple consecutive execution cycles must be greater than the preset torque threshold to meet the torque protection condition, thereby reducing the contingency of the judgment process.

[0017] Optionally, determining whether a same-cycle speed condition is met according to the previous speed error value and the next speed error value includes: In response to the previous speed error value being greater than or equal to a preset error threshold, and the next speed error value being greater than or equal to the preset error threshold, determining that the same-cycle speed condition is met; In response to the previous rotational speed error value being smaller than a preset error threshold, and / or the subsequent rotational speed error value being smaller than a preset error threshold, it is determined that the same-cycle rotational speed condition is not satisfied.

[0018] When the previous speed error value and the next speed error value are both greater than or equal to the preset error threshold, it means that there is a large gap between the measured value and the calculated value of the motor speed in two adjacent execution cycles. It can be determined that there is no misjudgment, the vehicle is traveling on a bad road, and the speed conditions of the same cycle are met, and the self-protection function needs to be turned on.

[0019] Based on the same inventive concept, the present disclosure also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable by the processor, wherein the processor implements the method as described above when executing the computer program.

[0020] Based on the same inventive concept, the present disclosure also provides a vehicle, comprising the above-mentioned electronic device.

[0021] As can be seen from the above, the self-protection control method, electronic device and vehicle of the electric drive system provided by the present application obtain vehicle operating parameters according to a preset execution cycle, and determine whether the protection control condition is met according to the vehicle operating parameters of two adjacent execution cycles; in response to the protection control condition being met, the counter is assigned a preset first count value, and the function protection flag is assigned a default startup parameter value; in response to the function protection flag being taken as the default startup parameter value, the default maximum available torque of the motor is reduced to the preset safe maximum available torque according to the preset first adjustment duration. Whether the vehicle is driving on a bad road is determined by whether the protection control condition is met. If the vehicle is driving on a bad road, it is determined that the vehicle's electric drive system is at risk of damage. The assignment of the function protection flag is used to determine whether to start the self-protection control, and the assignment of the counter is used to determine the degree of damage risk of the electric drive system. When the assignment of the protection flag is the default startup parameter value and the assignment of the counter is the first count value, the default maximum available torque of the motor is reduced to the safe maximum available torque according to the preset first adjustment duration. By lowering the upper limit of the requested torque, the impact stress is reduced, the risk of shaft tooth damage is reduced, and the safety of the electric drive system is ensured. At the same time, the torque is adjusted through the first adjustment duration to ensure the smoothness of the torque adjustment, giving users a better driving experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the present application or related technologies, the drawings required for use in the embodiments or related technical descriptions are briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 This is a flow chart of a self-protection control method of an electric drive system according to an embodiment of the present application; Figure 2 This is a flow chart of shutting down the self-protection function by counting delay in an embodiment of the present application; Figure 3 This is a flowchart of an embodiment of the present application for determining whether a protection control condition is met; Figure 4 This is a schematic diagram of the structure of a self-protection control device for an electric drive system according to an embodiment of the present application; Figure 5 It is a schematic diagram of the structure of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0024] In order to make the objectives, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0025] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present application should be the usual meanings understood by people with ordinary skills in the field to which the present application belongs. The "first", "second" and similar words used in the embodiments of the present application do not represent any order, quantity or importance, but are only used to distinguish different components. "Including" or "comprising" and similar words mean that the elements or objects appearing in front of the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0026] It should be understood herein that any number of elements in the drawings is for illustration rather than limitation, and any naming is only for distinction rather than having any limiting meaning.

[0027] Based on the description of the above background technology, the related technology also has the following situations: The electric drive system is the core of new energy vehicles. It is generally composed of a motor, a controller and a reducer. The electric drive system is responsible for converting electrical energy into mechanical energy to drive the vehicle forward. The electric drive system plays the role of "engine, electronic control unit, and gearbox" in fuel vehicles, and has a great impact on the core indicators of the performance of new energy vehicles, such as power, economy, comfort, and safety. Its structural form directly affects the layout of the new energy vehicle drive system. At present, the three-in-one electric drive system that integrates the motor, controller and reducer has become the mainstream of the development of pure new energy vehicle electric drive systems due to its advantages such as lightweight, space saving and low cost.

[0028] Among them, the motor is generally used together with the electric drive axle, including the following two forms: The motor-drive axle integrated drive system integrates the motor, fixed speed ratio reducer and differential into a whole, and two half-axles are connected to the drive wheels. The motor-drive axle integrated drive system layout has two types: coaxial and dual.

[0029] The motor-drive axle combined drive mode is mainly composed of motor, drive axle, electronic control system and other components. The motor, as the power source of the vehicle, directly drives the drive axle to achieve the driving force of the vehicle; the drive axle, as an important component of the transmission system, is mainly responsible for transmitting the power of the motor to the wheels; the electronic control system is responsible for controlling the working status of the motor and drive axle to achieve intelligent regulation.

[0030] The motor controller is a device that controls the drive motor of new energy vehicles and is the control center of the power system. It receives control information transmitted by the vehicle controller and control mechanisms (brake pedal, accelerator pedal, shift mechanism), converts the DC power of the power battery into the AC power required by the drive motor, and controls the speed, torque, and steering of the drive motor by controlling the voltage and current of the drive motor to achieve the starting, forward and backward speed, climbing intensity and other driving conditions of the new energy vehicle, or controls the output of the power battery accordingly to help the new energy vehicle brake, or recover part of the braking energy into the power battery.

[0031] The main function of the reducer is to reduce the speed, increase the output torque, and reduce the inertia of the load. When the output speed of the motor is input from the driving shaft, it drives the small gear to rotate, and the small gear drives the large gear to move. The large gear has more teeth than the small gear, and the speed of the large gear is slower than that of the small gear. The output is then output by the output shaft of the large gear, thereby playing the role of output reduction. The reducer is an independent closed transmission device between the prime mover and the working machine. It is a relatively precise machine. Its purpose is to reduce the speed and increase the torque.

[0032] It can be seen that the electric drive system is relatively sophisticated. When the vehicle continues to accelerate through continuous bad roads (such as washboard roads, Belgian roads, pothole roads, etc.), the vehicle wheel-end load will fluctuate violently. The impact caused by the fluctuation will be transmitted to the shaft teeth of the electric drive system through the output shaft of the reducer, causing damage to the mechanical structure of the reducer and motor, and reducing the service life of the motor and reducer. In extreme cases, the impact stress may exceed the yield strength that the shaft tooth material can withstand, causing damage to the reducer and motor shaft teeth, making the vehicle unable to drive normally.

[0033] The self-protection control method, electronic device and vehicle of the electric drive system provided in the embodiment of the present application obtain vehicle operating parameters according to a preset execution cycle, and determine whether the protection control condition is met according to the vehicle operating parameters of two adjacent execution cycles; in response to the protection control condition being met, the counter is assigned a preset first count value, and the function protection flag is assigned a default startup parameter value; in response to the function protection flag being taken as the default startup parameter value, the default maximum available torque of the motor is reduced to the preset safe maximum available torque according to the preset first adjustment duration. Whether the vehicle is traveling on a bad road is determined by whether the protection control condition is met. If the vehicle is traveling on a bad road, it is determined that the vehicle's electric drive system is at risk of damage. The assignment of the function protection flag is used to determine whether to start the self-protection control, and the assignment of the counter is used to determine the degree of damage risk of the electric drive system. When the assignment of the protection flag is the default startup parameter value and the assignment of the counter is the first count value, the default maximum available torque of the motor is reduced to the safe maximum available torque according to the preset first adjustment duration. By lowering the upper limit of the requested torque, the impact stress is reduced, the risk of shaft tooth damage is reduced, and the safety of the electric drive system is ensured. At the same time, the torque is adjusted through the first adjustment duration to ensure the smoothness of the torque adjustment, giving users a better driving experience.

[0034] The self-protection control method of the electric drive system provided by the embodiments of the present application is described in detail below with reference to the accompanying drawings.

[0035] In some embodiments, Figure 1 As shown, the self-protection control method of the electric drive system includes: Step 101: Acquire vehicle operating parameters according to a preset execution cycle, and determine whether a protection control condition is satisfied according to the vehicle operating parameters of two adjacent execution cycles.

[0036] During specific implementation, the execution cycle t1 of the self-protection function task of the software is set, the operation flag m1 and counter c1 of the self-protection function are created, and the execution cycle t1, the operation flag m1 and the counter c1 are all initialized to 0. The vehicle operation parameters are collected once in each execution cycle to determine whether there is a risk of damage to the drive system. Among them, the vehicle operation parameters are parameter information generated during the vehicle driving process, including motor speed, output torque, detection speed, and left wheel speed and right wheel speed. There is too much randomness in judging whether the protection control conditions are met based on the vehicle operation parameters in a single cycle, so it is necessary to make a comprehensive judgment based on the vehicle operation parameters in two adjacent execution cycles to reduce the randomness of conditional judgment and improve the accuracy of conditional judgment.

[0037] Among them, the protection control condition is the judgment condition for determining whether the vehicle is traveling on a loop road, that is, when the protection control condition is met, it is determined that the vehicle is traveling on a bad road, and the vehicle's self-protection function needs to be activated. When the protection control condition is not met, it is determined that the vehicle is traveling on a normal road, and the self-protection function needs to be turned off with a delay to avoid protection shutdown caused by misjudgment, avoid the absence of protection control of the electric drive system, and increase the probability of successful protection.

[0038] Among them, the protection control conditions include speed protection conditions, vehicle speed protection conditions and torque protection conditions. Different conditions verify each other to avoid the contingency caused by a single judgment condition.

[0039] The speed protection condition requires that the speed difference between the detected motor speeds in two adjacent execution cycles is greater than or equal to the preset speed difference threshold. This is because, if driving on a normal road, the speed change in two adjacent speed cycles is small or even consistent. If the speed difference in two adjacent execution cycles is greater than or equal to the speed difference, it means that the vehicle is driving on a bad road. The impact of the bad road on the electric drive system causes the speed to fluctuate frequently in a short period of time. Therefore, the speed protection condition can be used as one of the conditions for judging whether the vehicle is driving on a loop road.

[0040] In order to ensure the accuracy of cross-cycle speed judgment, it is necessary to determine whether the speed protection conditions are really met through the fluctuation of the motor speed in the same cycle. Therefore, it is necessary to calculate the corresponding calculated speed through the minimum value of the left wheel speed and the right wheel speed to verify whether there is really a speed fluctuation. If the difference between the calculated speed and the motor speed is greater than the preset error threshold, it means that the motor speed fluctuates greatly and the vehicle may be driving on a bad road, because when driving on a bad road, frequent impacts may cause a large difference between the tire end (corresponding to the output shaft of the motor) and the motor end (corresponding to the input shaft), and this difference is the cause of the damage to the shaft teeth.

[0041] When driving on normal roads, the difference between the motor speed and the calculated speed should be within a certain error. If there is a large difference between the detected value and the calculated value, it means that there is a lack of synchronization when the shaft gear transmits the speed. In order to synchronize the speed, the pressure between the shaft gears will increase, which will lead to excessive wear of the shaft gears and even damage to the shaft gears. Therefore, when the speed difference between the calculated speed and the motor speed in a single execution cycle is large, there may be a risk of damage to the shaft gears. At the same time, in order to avoid misjudgment, only when there is a large difference between two adjacent execution cycles can it be determined that the speed conditions for a single execution cycle are met, and the electric drive system needs to be protected.

[0042] The speed protection condition requires that the detected vehicle speed within the execution cycle is greater than or equal to the preset speed threshold. This is because when driving at low speeds, even when driving on bad roads, the pressure between the transmission shaft teeth of the electric drive system is naturally smaller due to the slow speed and less bumps on bad roads. Within the tolerance range of the shaft teeth, no obvious damage will occur to the shaft teeth. Therefore, the self-protection function of the electric drive system needs to be turned on only when driving at high speeds. In order to avoid contingency, the vehicle speed needs to be greater than the preset speed threshold for multiple consecutive execution cycles to reduce the contingency of the judgment process.

[0043] The torque protection condition requires that the output torque within the execution cycle is greater than or equal to the preset torque threshold. This is because when the vehicle is driving at a low torque, even if it is driving on a bad road, the output torque is small. Even if the impact caused by driving on a bad road will increase the torque between the shaft teeth, the increased torque is still within the tolerance range of the shaft tooth material and will not cause significant damage to the structure and life of the shaft teeth. Only when a large torque is output, the transmission torque between the shaft teeth is already very large. After the torque generated by the superimposed impact, it may exceed the limit that the shaft tooth material can withstand, causing irreversible damage to the shaft teeth. Therefore, the self-protection function of the electric drive system needs to be turned on only when driving at a high torque. In order to avoid contingency, the output torque of multiple consecutive execution cycles needs to be greater than the preset torque threshold to reduce the contingency of the judgment process.

[0044] Whether the vehicle is driving on a bad road is determined by whether the protection control conditions are met. The protection control conditions are divided into multiple sub-conditions, which verify each other, thereby improving the accuracy of the protection control condition judgment and achieving the correct start-up of the self-protection function. While protecting the electric drive system, it is possible to avoid arbitrarily starting the self-protection function and affecting the normal driving of the vehicle.

[0045] Step 102: In response to the protection control condition being met, the counter is assigned a preset first count value, and the function protection flag is assigned a default startup parameter value.

[0046] In specific implementation, if the protection control conditions are met, it means that the impact generated by driving on a bad road has reached a level that can damage the shaft teeth of the electric drive system, and the self-protection function of the electric drive system needs to be turned on. For example, the default startup parameter value is 1. The key to determining whether to start the self-protection function is the assignment of the function protection flag bit, and the parameter that determines the assignment of the function protection flag bit is the count value of the counter. When the count value of the counter is 0, that is, c1=0, the function protection flag bit is assigned to m1=0, indicating that the self-protection function is turned off; when the count value of the counter is not 0, that is, c1≠0, the function protection flag bit is assigned to m1=1, indicating that the self-protection function is started.

[0047] When the protection control conditions are met, the counter is assigned a preset first count value, wherein the first count value is a value greater than 0. However, in order to achieve delayed exit from the self-protection function, the first count value is generally set to a value greater than or equal to 5. Taking the first count value equal to 5 as an example, after the protection control conditions are met, no matter what the current count value of the counter is, the counter is assigned a preset first count value, that is, the count value of the counter is assigned to c1=5. At this time, the count value of the counter is not 0, and the function protection flag needs to be assigned to the default startup parameter value 1 to start the self-protection function.

[0048] Step 103: In response to the function protection flag being a default startup parameter value, the default maximum available torque of the motor is reduced to a preset safe maximum available torque according to a preset first adjustment duration.

[0049] During specific implementation, when the value of the function protection flag is the default startup parameter value, it means that the self-protection function is activated and enters the self-protection control process. The default maximum available torque of the motor is reduced to the preset safe maximum available torque according to the preset first adjustment time, and when the value of the function protection flag becomes the closed parameter value (for example, m1=0), the safe maximum available torque is smoothly increased to the default maximum available torque.

[0050] The default maximum available torque is the maximum torque value that the drive motor can output when the motor is not restricted (not considering the overload condition), indicating the maximum output capacity of the motor. The safe maximum available torque is the maximum torque that can be output after the motor is restricted, indicating the maximum torque value that the motor is allowed to output without damaging the shaft gear of the electric drive system.

[0051] The safe maximum available torque is less than the default maximum available torque. By limiting the output capacity of the motor to reduce the upper limit of the output torque of the electric drive system, the torque at the reducer input end is limited to a range less than or equal to the safe maximum available torque, which realizes the reserve of the torque between the shaft teeth, thereby reducing the maximum value of the torque between the shaft teeth inside the electric drive system. Even if the bad road impact increases the torque between the shaft teeth, because there is a certain torque reserve, the increased torque between the shaft teeth will remain below the maximum torque that the shaft gear material can withstand, so that the impact force remains below the yield strength and will not cause irreversible damage to the shaft gear. By reducing the upper limit of the requested torque, the impact stress between the shaft teeth is reduced, the risk of shaft gear damage is reduced, and the safety of the electric drive system is ensured.

[0052] When lowering the default maximum available torque, there is a situation where the user is driving the vehicle with a torque greater than the safe maximum available torque (for example, the default maximum available torque). At this time, if the default maximum available torque is instantly reduced to the safe maximum available torque, it will cause the output torque to change significantly in a very short period of time, causing the vehicle to jerk. Therefore, in order to ensure that there is no jerking during the torque adjustment process, it is necessary to ensure the smoothness of the maximum available torque reduction process.

[0053] The maximum available torque reduction process is as follows: calculate the torque difference between the default maximum available torque and the safe maximum available torque, determine the ratio of the torque difference and the first adjustment duration as the torque reduction rate, and reduce the default maximum available torque to the safe maximum available torque according to the torque reduction rate to ensure the smoothness of the torque upper limit reduction and ensure that when the vehicle outputs the default maximum available torque (or other torques greater than the safe maximum available torque), it will not jerk due to self-protection control. The torque is adjusted by the first adjustment duration to ensure the smoothness of the torque adjustment and bring users a better driving experience.

[0054] In summary, whether the vehicle is traveling on a bad road is determined by whether the protection control conditions are met. If the vehicle is traveling on a bad road, it is determined that the vehicle's electric drive system is at risk of damage. The assignment of the function protection flag is used to determine whether to start the self-protection control, and the assignment of the counter is used to determine the degree of damage risk of the electric drive system. When the assignment of the protection flag is the default startup parameter value and the assignment of the counter is the first count value, the default maximum available torque of the motor is reduced to the safe maximum available torque according to the preset first adjustment time. By reducing the upper limit of the requested torque, the impact stress is reduced, the risk of shaft tooth damage is reduced, and the safety of the electric drive system is ensured. At the same time, the torque is adjusted through the first adjustment time to ensure the smoothness of the torque adjustment, giving users a better driving experience.

[0055] In some embodiments, Figure 2 As shown, the self-protection control method of the electric drive system also includes: Step 201: In response to the protection control condition not being met, determining the current count value of the counter.

[0056] During specific implementation, if the protection control conditions are not met, it means that the current impact force will not damage the shaft teeth of the electric drive system, and you can prepare to exit the self-protection control process, that is, prepare to change the function protection flag from the default startup parameter value to the shutdown parameter value to achieve the shutdown of the self-protection function. However, in order to avoid frequent activation and deactivation of the self-protection function, and at the same time to avoid misjudgment caused by a single detection error, a delayed exit is required when exiting the self-protection function. In this application, a counting delay is used to realize the exit of the self-protection function, rather than a time delay strategy for delayed exit control, because time cannot well reflect the impact judgment of each execution cycle.

[0057] The counting delay control strategy is adopted. Each time it is determined that the protection control condition is not met, the count value of the counter is reduced by one, that is, c1=c1-1, until the count value of the counter is reduced to the closing parameter value 0, the self-protection control is exited, and the safe maximum available torque is smoothly restored to the default maximum available torque to complete the delayed exit of the self-protection function. Before the count value of the counter is reduced to the closing parameter value, if the protection control condition is met, the count value of the counter is reassigned to the first count value to ensure that the self-protection function continues to be executed to protect the safety of the electric drive system. When it is determined again that the protection control condition is not met, the first count value is reduced by one to start the delayed exit control.

[0058] The self-protection function can only be exited if the judgment that the protection control conditions are not met occurs 5 times in a row (the first count value). The control strategy of counting delay exit can avoid using too many parameters for control and improve control efficiency. When the delayed exit control is interrupted, it is also only necessary to change the count value of the counter. The count value of the counter is always used for exit and opening control. It is simple and efficient, avoiding the need for repeated timing and zeroing of the timing duration when using time for delay control, and saving the cost of the timer in hardware. The counting delay strategy avoids frequent switching between the safe maximum available torque and the default maximum available torque, ensuring the smoothness of the self-protection control process.

[0059] Therefore, the premise of counting delay control is that when a judgment that the protection control conditions are not met occurs, the current count value of the counter is first determined, so that the current count value is used as the basis for the cumulative reduction of the count. Generally speaking, if the judgment that the protection control conditions are not met occurs for the first time, the current count value is the first count value.

[0060] Step 202: In response to the current count value being greater than zero, the current count value is cumulatively decremented once to obtain an updated count value.

[0061] In specific implementation, if the current count value is greater than zero, it means that the self-protection function has not been exited at this time, and the current count value needs to be continued to be cumulatively decremented, that is, the updated count value = the current count value - 1. For example, if the current count value is 5, the updated count value = 5-1 = 4. If the judgment that the protection control condition is not met appears again, at this time, the new current count value = the updated count value = 4, the new updated count value = the current count value - 1 = 4-1 = 3, and so on, until the updated count value = 0, the value of the function protection flag is assigned to the shutdown parameter value to turn off the self-protection function.

[0062] Step 203 : In response to the updated count value being greater than the zero value, limiting the requested torque of the motor according to the safety upper limit torque.

[0063] In specific implementation, if the updated count value is greater than zero, it means that the delayed exit control has not ended, the number of consecutive determinations of not meeting the protection control conditions is small, and there may be contingency. Because the judgment of the protection control conditions is relatively strict, data fluctuations are likely to cause a single judgment result that the protection control conditions are not met. It is necessary to continue to keep the self-protection function turned on and continue to limit the output of the motor torque with the safe maximum available torque to protect the safety of the electric drive system. Among them, the safe upper limit torque is the value of the maximum available torque in the cumulative decrease process. When the count value is the first count value, the safe upper limit torque is equal to the safe maximum available torque. As the count value decreases cumulatively, the updated count value / first count value is determined as the available torque compensation coefficient, and the difference between the default maximum available torque and the safe maximum available torque is determined as the releasable torque, the product of the available torque compensation coefficient and the releasable torque is determined as the available compensation torque, and the sum of the available compensation torque and the safe maximum available torque is determined as the safe upper limit torque. Because, as the count value decreases cumulatively, it means that the risk of damage to the gear shaft is getting smaller and smaller, and a part of the upper limit value of the available torque can be released to improve the power performance of the vehicle and ensure the smoothness of the change process of the available torque upper limit.

[0064] In some embodiments, after limiting the requested torque of the motor according to the safety upper limit torque, the method further includes: Step 2031: Determine a new conditional judgment result.

[0065] In specific implementation, after a cumulative decrement, if the updated count value is greater than zero, it means that it is still in the stage of delayed shutdown of the self-protection function. At this time, it is necessary to continue to determine new conditional judgment results to determine whether the vehicle has really left the bad road conditions. It is necessary to continue to judge whether the protection control conditions are met and perform subsequent processing according to the corresponding new conditional judgment results, thereby achieving delayed exit while avoiding the randomness of a single judgment.

[0066] Step 2032: In response to the new conditional judgment result that the protection control condition is satisfied, the update count value is restored to the first count value.

[0067] During specific implementation, if the new condition judgment result is that the protection control condition is met, it means that the vehicle has returned to a bad road and needs to continue to limit the torque and keep the self-protection control turned on. The count value of the counter will be restored to the first count value to ensure that when it is detected again that the protection control condition is not met, the counting delay exit strategy can also be implemented to avoid accidental influences, improve the accuracy of control, avoid the exit of the self-protection function due to accidental misjudgment, and reduce the risk of damage to the gear shaft.

[0068] Step 2033: In response to the new conditional judgment result that the protection control condition is not satisfied, the update count value is cumulatively decremented once.

[0069] In specific implementation, for the counting delay control strategy, for each determination that the protection control condition is not met, the count value of the counter is reduced by one, that is, c1=c1-1, until the count value of the counter is reduced to the shutdown parameter value 0, the self-protection control is exited, and the safe maximum available torque is smoothly restored to the default maximum available torque, and the delayed exit of the self-protection function is completed. Before the count value of the counter is reduced to the shutdown parameter value, if the protection control condition is met, the count value of the counter is reassigned to the first count value to ensure that the self-protection function continues to be executed to protect the safety of the electric drive system, and when it is determined again that the protection control condition is not met, the first count value is reduced by one, and the delayed exit control begins.

[0070] Step 204: In response to the update count value being equal to zero, the function protection flag is assigned a value as a shutdown parameter value, and the safe maximum available torque of the motor is restored to a default maximum available torque according to a preset second adjustment time.

[0071] During specific implementation, if the update count value is equal to zero, it means that the self-protection function can be turned off, and the value of the function protection flag is assigned to the shutdown parameter value 0 to turn off the self-protection function. At this time, it is necessary to lift the restriction on the motor output and restore the motor's safe maximum available torque to the default maximum available torque according to the preset second adjustment time.

[0072] The torque recovery process can be as follows: calculate the torque difference between the default maximum available torque and the safe maximum available torque, determine the ratio of the torque difference and the second adjustment time as the torque recovery rate, and restore the safe maximum available torque to the default maximum available torque according to the torque recovery rate to ensure the smoothness of the torque upper limit recovery and ensure that when the vehicle outputs at the safe maximum available torque, it will not jerk due to the exit control of the restored torque. Performing torque recovery through the second adjustment time ensures the smoothness of the torque recovery and brings a better driving experience to users.

[0073] In some embodiments, two adjacent execution cycles include a previous execution cycle and a subsequent execution cycle; Figure 3 As shown, whether the protection control condition is met is determined according to the vehicle operation parameters of two adjacent execution cycles, including: Step 301: Determine whether a speed protection condition is met based on a previous motor speed in a vehicle operating parameter of a previous execution cycle and a next motor speed in a vehicle operating parameter of a next execution cycle.

[0074] In specific implementation, n11 is used to represent the actual speed of the previous motor in the vehicle operating parameters of the previous execution cycle, and n21 is used to represent the actual speed of the next motor in the vehicle operating parameters of the next execution cycle to determine whether the speed protection condition is met, wherein the previous motor actual speed n11 and the next motor actual speed n21 are both actual speed values ​​of the motor detected by sensors and other detection equipment. Since the impact of driving on bad roads will cause obvious changes in the speed, whether the speed protection condition is met requires more stringent judgment, so the speed protection condition can be divided into two sub-conditions, namely the cross-cycle speed condition and the same-cycle speed condition.

[0075] Among them, the cross-cycle speed condition requires that the speed difference between the previous motor actual speed n11 and the next motor actual speed n21 in two adjacent execution cycles meet certain requirements. The same-cycle speed condition requires that the previous motor actual speed n11 and the next motor actual speed n21 both meet the requirements of accurate speed detection in their respective cycles. The process of determining whether the speed protection condition is met is as follows: In some embodiments, the previous motor speed includes the detected previous motor actual speed and the previous calculated speed calculated according to the vehicle operating parameters, and the next motor speed includes the detected next motor actual speed and the next calculated speed calculated according to the vehicle operating parameters; determining whether the speed protection condition is met according to the previous motor speed in the vehicle operating parameters of the previous execution cycle and the next motor speed in the vehicle operating parameters of the next execution cycle includes: Step 3011: Determine the speed difference between the actual speed of the previous motor and the actual speed of the next motor, and determine whether the cross-cycle speed condition is met based on the speed difference.

[0076] In specific implementation, when driving on normal roads, the motor speeds in two adjacent execution cycles should be similar, so the speed difference between the actual speed of the previous motor and the actual speed of the next motor can be used to determine whether the vehicle is driving on a bad road. If the speed difference is greater than the preset difference threshold, that is, |n11-n21|>difference threshold, it means that the vehicle is driving on a bad road, the speed changes greatly, and it will cause an impact on the electric drive system. It is determined that the cross-cycle speed condition is met and the self-protection function needs to be turned on. If the speed difference is less than or equal to the preset difference threshold, that is, |n11-n21|≤difference threshold, it means that the vehicle is driving on a normal road, the speed changes are small, and it will not cause an impact on the electric drive system. It is determined that the cross-cycle speed condition is not met and there is no need to turn on the self-protection function.

[0077] Step 3012: Determine a previous speed error value between a previous motor actual speed and a previous calculated speed, and a subsequent speed error value between a subsequent motor actual speed and a subsequent calculated speed, and determine whether the same-cycle speed condition is met based on the previous speed error value and the subsequent speed error value.

[0078] In specific implementation, the process of determining the previous calculated speed is: The previous left wheel speed and the previous right wheel speed are determined in the vehicle operating parameters of the previous execution cycle, the minimum value of the previous left wheel speed and the previous right wheel speed is used as the previous target wheel speed, and the previous calculated speed is determined based on the previous target wheel speed and the current transmission ratio.

[0079] Among them, when the driving state (such as gear position) does not change, the transmission ratio between the wheel speed and the motor speed is certain, so the motor speed can be reversed according to the wheel speed and the transmission ratio. Under normal circumstances, the wheel speeds of the left and right wheels of the vehicle are consistent, and when calculating the speed, any speed value of the left wheel speed and the right wheel speed can be selected for calculation. However, the wheel speed may be different for different left and right wheels due to driving conditions such as turning and bumping. For example, when turning left, the left wheel on the inside of the curve has a smaller speed than the right wheel on the outside of the curve. On a bumpy road section, if the right wheel is temporarily vacant and the left wheel is grounded, the speed of the vacant right wheel will be greater than the speed of the grounded left wheel, so before the calculation, it is necessary to determine the previous target wheel speed for the previous calculation speed calculation. Then, since the transmission ratio = motor speed / wheel speed, the previous calculation speed n12 = previous target wheel speed × transmission ratio.

[0080] The process of determining the latter calculated speed is: The rear left wheel speed and the rear right wheel speed are determined in the vehicle operating parameters of the rear execution cycle, the minimum value of the rear left wheel speed and the rear right wheel speed is used as the rear target wheel speed, and the rear calculated speed is determined based on the rear target wheel speed and the current transmission ratio.

[0081] Among them, because a smaller speed value represents better contact with the ground, after determining the rear left wheel speed and the rear right wheel speed, the minimum value of the rear left wheel speed and the rear right wheel speed is taken as the rear target wheel speed, and the rear calculated speed n22 = rear target wheel speed × transmission ratio.

[0082] The previous motor actual speed and the next motor actual speed are the measured values ​​of the motor output end and the transmission input end. The previous calculated speed and the next calculated speed are the calculated values ​​determined according to the transmission output end. If driving on a normal road, the difference between the calculated value and the measured value should be small. If driving on a bad road, the difference between the calculated value and the measured value should be large. Therefore, the previous speed error value between the previous motor actual speed and the previous calculated speed, and the next speed error value between the next motor actual speed and the next calculated speed can be used to determine whether driving on a bad road. The determination process is as follows: In response to a previous rotation speed error value being greater than or equal to a preset error threshold, and a subsequent rotation speed error value being greater than or equal to the preset error threshold, it is determined that the same-cycle rotation speed condition is met.

[0083] During specific implementation, if the previous speed error value is greater than or equal to the preset error threshold, that is, |n11-n12|≥error threshold, and the next speed error value is greater than or equal to the preset error threshold, that is, |n21-n22|≥error threshold, it means that in two adjacent execution cycles, there is a large gap between the measured value and the calculated value of the motor speed. The large speed difference will impose additional stress on the transmission gear shaft, increasing the risk of damage to the gear shaft, and the judgment results of two consecutive cycles can be verified with each other to ensure the accuracy of the judgment. It can be determined that there is no misjudgment, that the vehicle is driving on a bad road, and that the speed conditions of the same cycle are met, and the self-protection function needs to be turned on.

[0084] In response to a previous rotational speed error value being smaller than a preset error threshold, and / or a subsequent rotational speed error value being smaller than a preset error threshold, it is determined that the same-cycle rotational speed condition is not satisfied.

[0085] During specific implementation, if the previous speed error value is less than the preset error threshold, and / or the next speed error value is less than the preset error threshold, it means that in the two adjacent execution cycles, the measured value and the calculated value in at least one execution cycle are similar, and the smaller speed difference will not impose greater stress on the transmission gear shaft, and there is no risk of damage to the gear shaft. If the judgment results of two consecutive execution cycles are different, it means that the judgment result of a certain execution cycle may be misjudged, then it is temporarily determined that the vehicle is traveling on a normal road, and it is determined that the same cycle speed condition is not met, and there is no need to turn on the self-protection function. If the judgment results of two consecutive execution cycles are the same, both of which indicate that the vehicle is traveling on a normal road, it is directly determined that there is no risk of damage to the gear shaft, and it is determined that the same cycle speed condition is not met, and there is no need to turn on the self-protection function. After determining that the same cycle speed condition is not met, it is necessary to continue to monitor whether the next two adjacent execution cycles meet the same cycle speed condition at the same time to eliminate the influence of errors.

[0086] Step 3013: In response to simultaneously satisfying the cross-cycle speed condition and the same-cycle speed condition, determining that the speed protection condition is satisfied.

[0087] In specific implementation, if both the cross-cycle speed condition and the same-cycle speed condition are met, it means that regardless of the same-cycle judgment or cross-cycle judgment, the vehicle is considered to be driving on a bad road, and the speed protection condition is determined to be met, and the self-protection function of the electric drive system needs to be turned on. Through mutual verification between the cross-cycle speed condition and the same-cycle speed condition, the contingency caused by a single judgment condition is avoided, the accuracy of risk judgment based on the speed protection condition is improved, and the erroneous activation of the self-protection control is avoided.

[0088] Step 3015: In response to the existence of unsatisfied conditions in the cross-cycle speed condition and the same-cycle speed condition, determining that the speed protection condition is not satisfied.

[0089] In specific implementation, if there are unsatisfied conditions in the cross-cycle speed condition and the same-cycle speed condition, it means that the determination results of the same-cycle determination and the cross-cycle determination are different, and there is a possibility of misjudgment, then it is temporarily determined that the vehicle is driving on a normal road, and it is determined that the speed protection condition is not met, and there is no need to turn on the self-protection function. And continue to monitor whether the next two adjacent execution cycles meet the speed protection condition.

[0090] Step 302: Determine whether a vehicle speed protection condition is satisfied based on a previous detected vehicle speed in a vehicle operating parameter of a previous execution cycle and a next detected vehicle speed in a vehicle operating parameter of a next execution cycle.

[0091] In some embodiments, step 302 includes: Step 3021: In response to the previous detected vehicle speed being greater than or equal to the preset vehicle speed threshold, and the next detected vehicle speed being greater than or equal to the preset vehicle speed threshold, it is determined that the vehicle speed protection condition is satisfied.

[0092] In specific implementation, the vehicle speed protection condition requires that the detected vehicle speed within the execution cycle is greater than or equal to the preset vehicle speed threshold, because when driving at low speed, even when driving on a bad road, due to the slow speed, the bumps on the bad road are small, and the pressure between the transmission shaft teeth of the electric drive system is naturally small. Within the tolerance range of the shaft teeth, no obvious damage will be caused to the shaft teeth, so the self-protection function of the electric drive system needs to be turned on only when driving at high speed. In order to avoid contingency, the vehicle speed needs to be greater than the preset vehicle speed threshold for multiple consecutive execution cycles to reduce the contingency of the judgment process.

[0093] If the previous detected vehicle speed is greater than or equal to the preset vehicle speed threshold, and the next detected vehicle speed is greater than or equal to the preset vehicle speed threshold, it means that the vehicle is in the high-speed driving stage, and the self-protection function is allowed to be turned on to determine whether the vehicle speed protection conditions are met. Step 3022: In response to a previous detected vehicle speed being less than a preset vehicle speed threshold, and / or a subsequent detected vehicle speed being less than a preset vehicle speed threshold, it is determined that the vehicle speed protection condition is not satisfied.

[0094] In specific implementation, if the previous detected vehicle speed is less than the preset vehicle speed threshold, and the next detected vehicle speed is greater than or equal to the preset vehicle speed threshold, the results of two consecutive execution cycles are inconsistent, there may be a misjudgment, and it is determined that the vehicle speed protection condition is not met; similarly, if the previous detected vehicle speed is greater than or equal to the preset vehicle speed threshold, and the next detected vehicle speed is less than the preset vehicle speed threshold, it can also be determined that the vehicle speed protection condition is not met. If the previous detected vehicle speed is less than the preset vehicle speed threshold, and the next detected vehicle speed is less than the preset vehicle speed threshold, it means that the vehicle is traveling at a low speed, there is no need to turn on the self-protection function, and it is determined that the vehicle speed protection condition is not met.

[0095] Step 303: Determine whether a torque protection condition is satisfied according to a previous output torque in the vehicle operating parameters of a previous execution cycle and a subsequent output torque in the vehicle operating parameters of a subsequent execution cycle.

[0096] In some embodiments, step 303 includes: Step 3031: In response to the previous output torque being greater than or equal to a preset torque threshold, and the next output torque being greater than or equal to the preset torque threshold, determining that a torque protection condition is satisfied; In specific implementation, the torque protection condition requires that the output torque within the execution cycle is greater than or equal to the preset torque threshold. This is because when the vehicle is driving at a small torque, even if it is driving on a bad road, the output torque is small. Even if the impact caused by driving on a bad road will increase the torque between the shaft teeth, the increased torque is still within the tolerance range of the shaft tooth material and will not have a significant impact on the structure and life of the shaft teeth. Only when a large torque is output, the transmission torque between the shaft teeth is already very large. After the torque generated by the superimposed impact, it may exceed the limit that the shaft tooth material can withstand, causing irreversible damage to the shaft teeth. Therefore, the self-protection function of the electric drive system needs to be turned on only when driving at a large torque. In order to avoid contingency, the output torque of multiple consecutive execution cycles needs to be greater than the preset torque threshold to reduce the contingency of the judgment process.

[0097] If the previous output torque is greater than or equal to the preset torque threshold, and the subsequent output torque is greater than or equal to the preset torque threshold, it means that there is no misjudgment, and the vehicle continues to output large torque. The impact may cause damage to the electric drive system, and the self-protection function is allowed to be turned on.

[0098] Step 3032: In response to the previous output torque being less than a preset torque threshold, and / or the next output torque being less than a preset torque threshold, determining that the torque protection condition is not satisfied.

[0099] In specific implementation, if the previous output torque is less than the preset torque threshold, and the subsequent output torque is greater than or equal to the preset torque threshold, and the results of two adjacent continuous execution cycles are inconsistent, it means that there is a misjudgment, and the data cannot be used as a basis for judgment, and it is temporarily determined that the vehicle speed protection condition is not met; similarly, when the previous output torque is greater than or equal to the preset torque threshold and the subsequent output torque is less than the preset torque threshold, it can also be temporarily determined that the vehicle speed protection condition is not met.

[0100] Step 304: In response to the rotation speed protection condition, the vehicle speed protection condition and the torque protection condition being satisfied at the same time, determining that the protection control condition is satisfied.

[0101] During specific implementation, if the speed protection condition, vehicle speed protection condition and torque protection condition are met at the same time, it means that the vehicle is traveling on a bad road at a high speed and high torque, which will cause greater damage to the shaft teeth of the electric drive system. It is necessary to turn on the self-protection function to protect the safety of the electric drive system. After determining that the protection control conditions are met, the default maximum available torque can be reduced to the safe maximum available torque to ensure that the impact will not cause damage to the shaft teeth.

[0102] Step 305: In response to the rotation speed protection condition, the vehicle speed protection condition, and the torque protection condition being unsatisfied, determining that the protection control condition is not satisfied.

[0103] During specific implementation, if the speed protection condition is not met, it means that the vehicle is not driving on a bad road and there is no bad road impact. There is no need to turn on self-protection, and it is determined that the protection control condition is not met; if the vehicle speed protection condition is not met, it means that the vehicle is driving at a low speed and the impact will not cause damage to the shaft teeth, and it is determined that the protection control condition is not met; if the torque protection condition is not met, it means that the vehicle is driving at a low torque and the impact will not cause damage to the shaft teeth, and it is determined that the protection control condition is not met.

[0104] The vehicle driving parameters of two consecutive execution cycles are used to determine whether the vehicle is driving on a bad road at a high speed and high torque, and then determine whether to turn on the self-protection function. This ensures that the impact of the bad road impact can be alleviated after the self-protection function is turned on, thereby protecting the electric drive system.

[0105] It should be noted that the method of the embodiment of the present application can be performed by a single device, such as a computer or server. The method of this embodiment can also be applied to a distributed scenario and completed by multiple devices cooperating with each other. In the case of such a distributed scenario, one of the multiple devices can only perform one or more steps in the method of the embodiment of the present application, and the multiple devices will interact with each other to complete the described method.

[0106] It should be noted that the above describes some embodiments of the present application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the above embodiments and still achieve the desired results. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0107] Based on the same inventive concept, corresponding to any of the above-mentioned embodiment methods, the present application also provides a self-protection control device for an electric drive system.

[0108] refer to Figure 4 , the self-protection control device of the electric drive system comprises: The condition judgment module 10 is configured to: obtain vehicle operation parameters according to a preset execution cycle, and determine whether the protection control condition is met according to the vehicle operation parameters of two adjacent execution cycles; The value assignment control module 20 is configured to: in response to the protection control condition being met, assign the counter to a preset first count value, and assign the function protection flag bit to a default startup parameter value; The self-protection control module 30 is configured to: in response to the value of the function protection flag being a default startup parameter value, reduce the default maximum available torque of the motor to a preset safe maximum available torque according to a preset first adjustment time.

[0109] For the convenience of description, the above device is described in terms of functions divided into various modules. Of course, when implementing the present application, the functions of each module can be implemented in the same or multiple software and / or hardware.

[0110] The device of the above embodiment is used to implement the self-protection control method of the electric drive system corresponding to any of the above embodiments, and has the beneficial effects of the corresponding method embodiment, which will not be repeated here.

[0111] Based on the same inventive concept, corresponding to any of the above-mentioned embodiments and methods, the present application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the self-protection control method of the electric drive system described in any of the above embodiments is implemented.

[0112] Figure 5 A more specific schematic diagram of the hardware structure of an electronic device provided in this embodiment is shown, and the device may include: a processor 1010, a memory 1020, an input / output interface 1030, a communication interface 1040, and a bus 1050. The processor 1010, the memory 1020, the input / output interface 1030, and the communication interface 1040 are connected to each other through the bus 1050 in the device.

[0113] The processor 1010 can be implemented by a general-purpose CPU (Central Processing Unit), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this specification.

[0114] The memory 1020 may be implemented in the form of ROM (Read Only Memory), RAM (Random Access Memory), static storage device, dynamic storage device, etc. The memory 1020 may store an operating system and other application programs. When the technical solutions provided in the embodiments of this specification are implemented by software or firmware, the relevant program codes are stored in the memory 1020 and are called and executed by the processor 1010.

[0115] The input / output interface 1030 is used to connect the input / output module to realize information input and output. The input / output module can be configured in the device as a component (not shown in the figure), or it can be externally connected to the device to provide corresponding functions. The input device may include a keyboard, a mouse, a touch screen, a microphone, various sensors, etc., and the output device may include a display, a speaker, a vibrator, an indicator light, etc.

[0116] The communication interface 1040 is used to connect a communication module (not shown) to realize communication interaction between the device and other devices. The communication module can realize communication through wired means (such as USB, network cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.).

[0117] The bus 1050 includes a path that transmits information between the various components of the device (eg, the processor 1010 , the memory 1020 , the input / output interface 1030 , and the communication interface 1040 ).

[0118] It should be noted that, although the above device only shows the processor 1010, the memory 1020, the input / output interface 1030, the communication interface 1040 and the bus 1050, in the specific implementation process, the device may also include other components necessary for normal operation. In addition, it can be understood by those skilled in the art that the above device may also only include the components necessary for implementing the embodiments of the present specification, and does not necessarily include all the components shown in the figure.

[0119] The electronic device of the above embodiment is used to implement the self-protection control method of the corresponding electric drive system in any of the above embodiments, and has the beneficial effects of the corresponding method embodiment, which will not be repeated here.

[0120] Based on the same inventive concept, corresponding to any of the above-mentioned embodiment methods, the present application also provides a non-transitory computer-readable storage medium, wherein the non-transitory computer-readable storage medium stores computer instructions, and the computer instructions are used to enable the computer to execute the self-protection control method of the electric drive system as described in any of the above embodiments.

[0121] The computer-readable medium of this embodiment includes permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, read-only compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, tape disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device.

[0122] The computer instructions stored in the storage medium of the above embodiments are used to enable the computer to execute the self-protection control method of the electric drive system as described in any of the above embodiments, and have the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0123] Based on the same inventive concept, corresponding to any of the above-mentioned embodiments and methods, the present application also provides a vehicle, including the electronic device or the self-protection control device of the electric drive system of the above-mentioned embodiments, and the self-protection control method of the electric drive system as described in any of the above embodiments is executed through the electronic device or the self-protection control device of the electric drive system of the above-mentioned embodiments, and has the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0124] It is understandable that before using the technical solutions of each embodiment of the present disclosure, the type, scope of use, usage scenarios, etc. of the personal information involved will be informed to the user in an appropriate manner, and the user's authorization will be obtained.

[0125] For example, in response to receiving an active request from a user, a prompt message is sent to the user to clearly remind the user that the operation requested to be performed will require obtaining and using the user's personal information. Thus, the user can independently choose whether to provide personal information to software or hardware such as an electronic device, application, server, or storage medium that performs the operation of the technical solution of the present disclosure according to the prompt message.

[0126] As an optional but non-limiting implementation, in response to receiving the user's active request, the prompt information may be sent to the user in the form of a pop-up window, in which the prompt information may be presented in text form. In addition, the pop-up window may also carry a selection control for the user to choose "agree" or "disagree" to provide personal information to the electronic device.

[0127] It is understandable that the above notification and the process of obtaining user authorization are merely illustrative and do not constitute a limitation on the implementation of the present disclosure. Other methods that meet relevant laws and regulations may also be applied to the implementation of the present disclosure.

[0128] A person skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present application is limited to these examples. In line with the concept of the present application, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the embodiments of the present application as described above, which are not provided in detail for the sake of simplicity.

[0129] In addition, to simplify the description and discussion, and in order not to make the embodiments of the present application difficult to understand, the known power / ground connections to the integrated circuit (IC) chip and other components may or may not be shown in the provided drawings. In addition, the device may be shown in the form of a block diagram to avoid making the embodiments of the present application difficult to understand, and this also takes into account the fact that the details of the implementation of these block diagram devices are highly dependent on the platform on which the embodiments of the present application are to be implemented (that is, these details should be fully within the scope of understanding of those skilled in the art). Where specific details (e.g., circuits) are set forth to describe exemplary embodiments of the present application, it is obvious to those skilled in the art that the embodiments of the present application can be implemented without these specific details or with changes in these specific details. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0130] Although the present application has been described in conjunction with specific embodiments of the present application, many alternatives, modifications and variations of these embodiments will be apparent to those skilled in the art from the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) may use the discussed embodiments.

[0131] The embodiments of the present application are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the present application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present application should be included in the protection scope of the present application.

Claims

1. A self-protection control method for an electric drive system, characterized in that: include: Acquiring vehicle operating parameters according to a preset execution cycle, and determining whether a protection control condition is satisfied according to the vehicle operating parameters of two adjacent execution cycles; In response to satisfying the protection control condition, assigning a counter to a preset first count value, and assigning a function protection flag to a default startup parameter value; In response to the value of the function protection flag being the default startup parameter value, the default maximum available torque of the motor is reduced to a preset safe maximum available torque according to a preset first adjustment duration.

2. The self-protection control method of the electric drive system according to claim 1, characterized in that: Also includes: In response to the protection control condition not being satisfied, determining a current count value of the counter; In response to the current count value being greater than zero, the current count value is cumulatively decremented once to obtain an updated count value; In response to the updated count value being greater than a zero value, limiting the requested torque of the motor according to a safety upper limit torque; In response to the update count value being equal to zero, the value of the function protection flag is assigned to a shutdown parameter value, and the safe maximum available torque of the motor is restored to the default maximum available torque according to a preset second adjustment duration.

3. The self-protection control method of the electric drive system according to claim 2, characterized in that: After limiting the requested torque of the motor according to the safety upper limit torque, the method further includes: Determine new conditional judgment results; In response to the new condition judgment result being that the protection control condition is satisfied, restoring the update count value to the first count value; In response to the new condition judgment result being that the protection control condition is not satisfied, the update count value is cumulatively decremented once.

4. The self-protection control method of the electric drive system according to claim 1, characterized in that: The two adjacent execution cycles include a previous execution cycle and a subsequent execution cycle; the determining whether the protection control condition is met according to the vehicle operation parameters of the two adjacent execution cycles includes: determining whether a speed protection condition is met according to a previous motor speed in the vehicle operating parameters of the previous execution cycle and a subsequent motor speed in the vehicle operating parameters of the subsequent execution cycle; determining whether a vehicle speed protection condition is satisfied according to a previous detected vehicle speed in the vehicle operating parameters of the previous execution cycle and a subsequent detected vehicle speed in the vehicle operating parameters of the subsequent execution cycle; determining whether a torque protection condition is satisfied according to a previous output torque in the vehicle operating parameters of the previous execution cycle and a subsequent output torque in the vehicle operating parameters of the subsequent execution cycle; In response to simultaneously satisfying the rotation speed protection condition, the vehicle speed protection condition, and the torque protection condition, determining that the protection control condition is satisfied; In response to a condition among the rotation speed protection condition, the vehicle speed protection condition, and the torque protection condition being not satisfied, it is determined that the protection control condition is not satisfied.

5. The self-protection control method of the electric drive system according to claim 4, characterized in that: The previous motor speed includes the detected previous motor actual speed and the previous calculated speed calculated according to the vehicle operating parameters, and the next motor speed includes the detected next motor actual speed and the next calculated speed calculated according to the vehicle operating parameters; the determining whether the speed protection condition is met according to the previous motor speed in the vehicle operating parameters of the previous execution cycle and the next motor speed in the vehicle operating parameters of the next execution cycle includes: Determine a speed difference between the actual speed of the previous motor and the actual speed of the next motor, and determine whether a cross-cycle speed condition is met according to the speed difference; Determine a previous speed error value between the previous motor actual speed and the previous calculated speed, and a subsequent speed error value between the subsequent motor actual speed and the subsequent calculated speed, and determine whether the same-cycle speed condition is met according to the previous speed error value and the subsequent speed error value; In response to simultaneously satisfying the inter-cycle speed condition and the same-cycle speed condition, determining that the speed protection condition is satisfied; In response to a condition between the inter-cycle speed condition and the same-cycle speed condition not being met, it is determined that the speed protection condition is not met.

6. The self-protection control method of the electric drive system according to claim 4, characterized in that: The determining whether the vehicle speed protection condition is met according to the previous detected vehicle speed in the vehicle operation parameters of the previous execution cycle and the next detected vehicle speed in the vehicle operation parameters of the next execution cycle includes: In response to the previous detected vehicle speed being greater than or equal to a preset vehicle speed threshold, and the next detected vehicle speed being greater than or equal to a preset vehicle speed threshold, determining that the vehicle speed protection condition is satisfied; In response to the previous detected vehicle speed being less than a preset vehicle speed threshold, and / or the next detected vehicle speed being less than a preset vehicle speed threshold, it is determined that the vehicle speed protection condition is not satisfied.

7. The self-protection control method of the electric drive system according to claim 4, characterized in that: The determining whether the torque protection condition is satisfied according to the previous output torque in the vehicle operation parameters of the previous execution cycle and the next output torque in the vehicle operation parameters of the next execution cycle comprises: In response to the previous output torque being greater than or equal to a preset torque threshold, and the next output torque being greater than or equal to a preset torque threshold, determining that the torque protection condition is satisfied; In response to the previous output torque being less than a preset torque threshold, and / or the next output torque being less than a preset torque threshold, it is determined that the torque protection condition is not satisfied.

8. The self-protection control method of the electric drive system according to claim 5, characterized in that: The determining whether the same-cycle speed condition is met according to the previous speed error value and the next speed error value includes: In response to the previous speed error value being greater than or equal to a preset error threshold, and the next speed error value being greater than or equal to the preset error threshold, determining that the same-cycle speed condition is met; In response to the previous speed error value being smaller than a preset error threshold, and / or the next speed error value being smaller than a preset error threshold, it is determined that the same-cycle speed condition is not met.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the program, the method according to any one of claims 1 to 8 is implemented.

10. A vehicle, characterized in that: Comprising the electronic device as claimed in claim 9.

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