CN117400737A - Power system risk state monitoring method and device and new energy automobile - Google Patents
Power system risk state monitoring method and device and new energy automobile Download PDFInfo
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
- B60L3/00—Electric devices on electrically-propelled vehicles for safety purposes; Monitoring operating variables, e.g. speed, deceleration or energy consumption
- B60L3/0023—Detecting, eliminating, remedying or compensating for drive train abnormalities, e.g. failures within the drive train
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
- B60L15/00—Methods, circuits, or devices for controlling the traction-motor speed of electrically-propelled vehicles
- B60L15/20—Methods, circuits, or devices for controlling the traction-motor speed of electrically-propelled vehicles for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
- B60L2240/00—Control parameters of input or output; Target parameters
- B60L2240/40—Drive Train control parameters
- B60L2240/42—Drive Train control parameters related to electric machines
- B60L2240/421—Speed
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
- B60L2240/00—Control parameters of input or output; Target parameters
- B60L2240/40—Drive Train control parameters
- B60L2240/42—Drive Train control parameters related to electric machines
- B60L2240/423—Torque
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
- B60L2240/00—Control parameters of input or output; Target parameters
- B60L2240/40—Drive Train control parameters
- B60L2240/46—Drive Train control parameters related to wheels
- B60L2240/461—Speed
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/60—Other road transportation technologies with climate change mitigation effect
- Y02T10/72—Electric energy management in electromobility
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Abstract
The application relates to the field of new energy automobiles and provides a power system risk state monitoring method and device and a new energy automobile. The method comprises the following steps: monitoring the wheel speed of one or two groups of coaxially driven wheels in the whole vehicle power system of the vehicle; calculating a wheel speed difference between the first coaxially driven wheel and the second coaxially driven wheel; if the driving shaft motor is in a risk state based on the wheel rotation speed difference value, calculating a motor rotation speed value of the driving shaft motor; inquiring a maximum electric drive external characteristic torque value corresponding to the motor rotation speed value, and inquiring a driving motor torque limit value corresponding to the wheel rotation speed difference value; and determining an actual request torque value of the driving motor according to the whole vehicle request torque value, the driving motor torque limit value and the maximum electric drive external characteristic torque value, and performing torque limit regulation and control on the driving shaft motor. The method and the device can effectively avoid the safety risk of the vehicle caused by violent driving of the vehicle in a special scene, give consideration to the power performance and the safety performance of the whole vehicle, and simultaneously reduce the hardware cost.
Description
Technical Field
The application relates to the field of new energy automobiles, in particular to a power system risk state monitoring method and device and a new energy automobile.
Background
The new energy automobile has the characteristics of quick power response, strong power and the like. In some special situations (such as the scenes of crossing roads, wet roads and the like), the road adhesion coefficient is low, and if the vehicle is driven on the roads vigorously, the phenomenon of wheel slip of the vehicle is easy to occur. Once the driving wheels of the vehicle slip, the driving torque cannot be effectively output to the driving wheels, and in addition, when the driving wheels on both sides of the driving shaft form a large torque difference, related power hardware is easily damaged, for example, the problems of shaft breakage, motor damage and the like of the driving shaft are easily caused.
The transmission solution is to add a hardware differential to protect the related power hardware of the vehicle, so that on one hand, the hardware cost is increased and the manufacturing cost of the whole vehicle is increased; on the other hand, the safety risk of the vehicle caused by the violent driving of the vehicle in a special scene cannot be well avoided, and the power performance and the safety performance of the whole vehicle are considered.
Disclosure of Invention
In view of this, the embodiment of the application provides a power system risk state monitoring method, a power system risk state monitoring device and a new energy automobile, so as to solve the problem that related power hardware of the automobile is protected by adding a hardware differential mechanism in the prior art, on one hand, the hardware cost is increased, and the manufacturing cost of the whole automobile is increased; on the other hand, the problem that the safety risk of the vehicle caused by the violent driving of the vehicle in a special scene can not be well avoided and the problem of the dynamic performance and the safety performance of the whole vehicle can be considered.
In a first aspect of an embodiment of the present application, a power system risk status monitoring method is provided, including:
monitoring wheel speeds of one or two groups of coaxial driving wheels in a whole vehicle power system of a vehicle, wherein the coaxial driving wheels share a driving shaft motor, and the coaxial driving wheels comprise a first coaxial driving wheel and a second coaxial driving wheel;
calculating a wheel speed difference between the first coaxially driven wheel and the second coaxially driven wheel;
if the driving shaft motor is in a risk state based on the wheel rotation speed difference value, calculating a motor rotation speed value of the driving shaft motor;
inquiring a maximum electric drive external characteristic torque value corresponding to the motor rotation speed value, inquiring a two-dimensional table of wheel rotation speed difference and motor torque limit to obtain a driving motor torque limit value corresponding to the wheel rotation speed difference;
determining an actual request torque value of a driving motor of a whole vehicle power system according to a whole vehicle request torque value of a vehicle, a driving motor torque limit value and a maximum electric drive external characteristic torque value;
and according to the actual torque value of the driving motor, performing torque limiting regulation and control on the driving shaft motor of the whole vehicle power system.
In a second aspect of the embodiments of the present application, there is provided a risk status monitoring device for a power system, including:
A monitoring module configured to monitor wheel speeds of one or two sets of coaxially driven wheels in a whole vehicle powertrain of a vehicle, wherein the one set of coaxially driven wheels share a drive shaft motor, and the one set of coaxially driven wheels includes a first coaxially driven wheel and a second coaxially driven wheel;
a first calculation module configured to calculate a wheel speed difference of the first coaxially driven wheel and the second coaxially driven wheel;
a second calculation module configured to calculate a motor rotational speed value of the drive shaft motor if it is determined that the drive shaft motor is in a risk state based on the wheel rotational speed difference;
the inquiring module is configured to inquire a maximum electric drive external characteristic torque value corresponding to the motor rotating speed value, inquire a two-dimensional table of the wheel rotating speed difference and the motor torque limit, and obtain a driving motor torque limit value corresponding to the wheel rotating speed difference;
the determining module is configured to determine an actual request torque value of the driving motor of the whole vehicle power system according to the whole vehicle request torque value, the driving motor torque limit value and the maximum electric drive external characteristic torque value of the vehicle;
and the regulating and controlling module is configured to regulate and control the torque limitation of the driving shaft motor of the whole vehicle power system according to the actual request torque value of the driving motor.
In a third aspect of the embodiments of the present application, a new energy automobile is provided,
the system comprises a whole vehicle controller and a whole vehicle power system, wherein the whole vehicle power system comprises a driving motor controller, a driving shaft motor and a transmission system;
the whole vehicle controller is used for realizing the power system risk state monitoring method of the first aspect so as to send the actual request torque value of the driving motor to the driving motor controller;
the driving motor controller is used for carrying out torque limiting regulation and control on the driving shaft motor through the transmission system according to the actual request torque value of the driving motor.
In a fourth aspect of the embodiments of the present application, there is provided a readable storage medium storing a computer program which, when executed by a processor, implements the steps of the above method.
Compared with the prior art, the embodiment of the application has the beneficial effects that: the method comprises the steps of monitoring the wheel speed of one or two groups of coaxial driving wheels in a whole vehicle power system of a vehicle, wherein the coaxial driving wheels share a driving shaft motor, and the coaxial driving wheels comprise a first coaxial driving wheel and a second coaxial driving wheel; calculating a wheel speed difference between the first coaxially driven wheel and the second coaxially driven wheel; if the driving shaft motor is in a risk state based on the wheel rotation speed difference value, calculating a motor rotation speed value of the driving shaft motor; inquiring a maximum electric drive external characteristic torque value corresponding to the motor rotation speed value, inquiring a two-dimensional table of wheel rotation speed difference and motor torque limit to obtain a driving motor torque limit value corresponding to the wheel rotation speed difference; determining an actual request torque value of a driving motor of a whole vehicle power system according to a whole vehicle request torque value of a vehicle, a driving motor torque limit value and a maximum electric drive external characteristic torque value; and according to the actual torque value of the driving motor, performing torque limiting regulation and control on the driving shaft motor of the whole vehicle power system. On one hand, hardware such as a hardware differential mechanism is not required to be additionally added, so that the hardware cost can be reduced, and the manufacturing cost of the whole vehicle can be reduced; on the other hand, the safety risk (such as the occurrence of the problems of broken drive shaft, motor damage and the like) of the vehicle caused by violent driving in a special scene can be effectively avoided, the driving reliability is improved, and meanwhile, the power performance and the safety performance of the whole vehicle can be considered.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following description will briefly introduce the drawings that are needed in the embodiments or the description of the prior art, it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic flow chart of a power system risk status monitoring method according to an embodiment of the present application;
fig. 2 is a graph showing a correspondence between a wheel speed difference value of a front axle power system and a front axle motor torque limit value in a power system risk state monitoring method according to an embodiment of the present application;
fig. 3 is a corresponding relation curve of a motor rotation speed value and a maximum electric drive external characteristic torque value of a front axle motor of a front axle power system in the power system risk state monitoring method provided by the embodiment of the application;
fig. 4 is a schematic structural diagram of a whole vehicle power system in the power system risk status monitoring method provided in the embodiment of the present application;
fig. 5 is a schematic diagram of torque limitation regulation of a drive shaft motor of a whole vehicle power system in the power system risk state monitoring method provided in the embodiment of the present application;
FIG. 6 is a schematic structural diagram of a risk status monitoring device for a power system according to an embodiment of the present disclosure;
fig. 7 is a schematic structural diagram of an electronic device according to an embodiment of the present application.
Detailed Description
In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular system configurations, techniques, etc. in order to provide a thorough understanding of the embodiments of the present application. It will be apparent, however, to one skilled in the art that the present application may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.
The new energy automobile in the embodiment of the application refers to an automobile adopting novel energy (non-traditional petroleum and diesel energy) and having advanced technology. The automobiles adopt a novel power system, so that the automobile emission can be effectively reduced, the influence on the environment is reduced, and the energy utilization efficiency is improved. The new energy automobiles of the embodiments of the present application include, but are not limited to, the following types of automobiles: electric Vehicles (EVs), pure electric vehicles (BEVs), fuel Cell Electric Vehicles (FCEVs), plug-in hybrid electric vehicles (PHEVs), hybrid Electric Vehicles (HEVs), and the like.
A method and apparatus for monitoring risk status of a power system according to embodiments of the present application will be described in detail with reference to the accompanying drawings.
Fig. 1 is a schematic flow chart of a power system risk status monitoring method according to an embodiment of the present application. The power system risk status monitoring method of fig. 1 may be performed by an overall vehicle controller of a new energy vehicle. As shown in fig. 1, the power system risk state monitoring method includes:
in step S101, the wheel speeds of one or two groups of coaxially driven wheels in the whole vehicle power system of the vehicle are monitored, wherein the one group of coaxially driven wheels share a driving shaft motor, and the one group of coaxially driven wheels comprise a first coaxially driven wheel and a second coaxially driven wheel.
Firstly, vehicle configuration parameters of a vehicle can be obtained; and then, determining the type of the whole vehicle power system of the vehicle according to the vehicle configuration parameters. The existing whole vehicle power system of the new energy automobile is mainly divided into a four-driving-force system and a two-driving-force system. The two driving force systems are a front axle power system (front drive vehicle type) or a rear axle power system (rear drive vehicle type).
As an example, assuming that a vehicle is of the front-drive type, its entire vehicle powertrain is a front axle powertrain, and a set of coaxially driven wheels includes a first front axle driven wheel (i.e., a first coaxially driven wheel) and a second front axle driven wheel (i.e., a second coaxially driven wheel), with their common drive axle motor being a front axle motor. The whole vehicle controller monitors wheel speed signals of the first front axle driving wheel and the second front axle driving wheel in real time.
As another example, assuming that a vehicle is of the rear drive type, its entire vehicle powertrain is a rear axle powertrain, and a set of coaxially driven wheels includes a first rear axle driven wheel (i.e., a first coaxially driven wheel) and a second rear axle driven wheel (i.e., a second coaxially driven wheel), with a common drive axle motor being the rear axle motor. The whole vehicle controller monitors wheel speed signals of the first rear axle driving wheel and the second rear axle driving wheel in real time.
As yet another example, assuming a vehicle of the four-wheel drive type, its entire vehicle powertrain is a four-drive system that includes two sets of coaxially driven wheels, namely, a set of front axle driven wheels and a set of rear axle driven wheels. A group of front axle drive wheels share a front axle motor and a group of rear axle drive wheels share a rear axle motor. The whole vehicle controller monitors wheel speed signals of the first front axle driving wheel, the second front axle driving wheel, the first rear axle driving wheel and the second rear axle driving wheel in real time.
In step S102, a wheel rotation speed difference between the first coaxially driven wheel and the second coaxially driven wheel is calculated.
Step S103, if it is determined that the drive shaft motor is in a risk state based on the wheel rotation speed difference, a motor rotation speed value of the drive shaft motor is calculated.
And a risk state used for representing the phenomenon that a driving shaft motor of the vehicle is abnormal in torque output (such as overlarge output torque and the like) or damaged.
Step S104, inquiring a maximum electric drive external characteristic torque value corresponding to the motor rotation speed value, and inquiring a two-dimensional table of the wheel rotation speed difference and the motor torque limit to obtain a driving motor torque limit value corresponding to the wheel rotation speed difference.
The maximum electric drive external characteristic torque value is related to the hardware performance of the driving shaft motor, and the maximum electric drive external characteristic torque value under different motor rotating speed values can be obtained through the hardware performance test of the driving shaft motor.
Step S105, determining the actual request torque value of the driving motor of the whole vehicle power system according to the whole vehicle request torque value, the driving motor torque limit value and the maximum electric drive external characteristic torque value of the vehicle.
And step S106, performing torque limiting regulation and control on a driving shaft motor of the whole vehicle power system according to the actual request torque value of the driving motor.
According to the technical scheme provided by the embodiment of the application, the wheel speed of the coaxial driving wheels of the whole vehicle power system of the vehicle is analyzed, and the risk state of the driving shaft motor of the vehicle is determined based on the analysis result; when the driving shaft motor is in a risk state, calculating a motor rotating speed value of the driving shaft motor, further determining a maximum electric drive external characteristic torque value according to the motor rotating speed value, and determining a driving motor torque limit value according to a wheel rotating speed difference value; finally, combining the whole vehicle required torque, the maximum electric drive external characteristic torque value and the driving motor torque limit value to determine the actual required torque value of the driving motor; finally, torque limiting regulation and control are carried out on a driving shaft motor of the whole vehicle power system based on the actual request torque value of the driving motor; on one hand, hardware such as a hardware differential mechanism is not required to be additionally added, so that the hardware cost can be reduced, and the manufacturing cost of the whole vehicle can be reduced; on the other hand, the safety risk (such as the occurrence of the problems of broken drive shaft, motor damage and the like) of the vehicle caused by violent driving in a special scene can be effectively avoided, the driving reliability is improved, and meanwhile, the power performance and the safety performance of the whole vehicle can be considered.
In some embodiments, calculating a wheel speed difference for the first and second coaxially driven wheels includes:
acquiring a first wheel speed value of a first coaxial driving wheel, a second wheel speed value of a second coaxial driving wheel and a tire radius value;
calculating a first wheel speed value of the first coaxially driven wheel according to the first wheel speed value and the tire radius value;
calculating a second wheel speed value of the second coaxially driven wheel based on the second wheel speed value and the tire radius value;
a wheel speed difference of the first coaxially driven wheel and the second coaxially driven wheel is calculated based on the first wheel speed value and the second wheel speed value.
As an example, assuming that a certain vehicle is a front-drive vehicle type and its whole vehicle power system is a front axle power system, a first wheel speed value D of a first front axle driving wheel in the front axle power system can be monitored and collected by the whole vehicle controller fl Second wheel speed value D of second front axle driving wheel fr And a tire radius R; then, a first wheel rotation speed value C of the first coaxially driven wheel is calculated according to the following formulas (1) and (2), respectively fl Second wheel speed value C of second coaxially driven wheel fr 。
In the formula (1), C fl A first wheel rotation speed value representing a first front axle drive wheel (first coaxial drive wheel), D fl A first wheel speed value representing a first front axle driven wheel, R representing a tire radius.
In the formula (2), C fr A second wheel speed value, D, representing a second front axle drive wheel (second coaxial drive wheel) fr A second wheel speed value representing a second front axle driven wheel, R representing a tire radius.
Next, a wheel speed difference between the first coaxially driven wheel and the second coaxially driven wheel is calculated according to the following equation (3).
In formula (3), ΔC f Representing the wheel speed difference of the front axle powertrain.
As another example, assuming that a certain vehicle is of a rear-drive type and its entire vehicle power system is a rear axle power system, the wheel speed difference of the rear axle power system may be calculated with reference to the foregoing method.
That is to say,wherein DeltaC r Representing the difference of the rotational speeds of wheels of a rear axle power system, D rl A third wheel speed value D representing the first rear axle drive wheel rr A fourth wheel speed value representing a second rear axle drive wheel.
As yet another example, assume that a vehicle is of a four-wheel drive type and its entire vehicle powertrain is a four-drive power system, including a front axle powertrain and a rear axle powertrain. The difference between the rotational speeds of the front axle power system and the rear axle power system may be calculated by referring to the foregoing method, and will not be described herein.
In some embodiments, determining that the drive shaft motor is in a risky state based on the wheel speed difference includes:
judging whether a first wheel rotating speed value of the first coaxial driving wheel and a second wheel rotating speed value of the second coaxial driving wheel are effective values or not;
if the first wheel rotating speed value and the second wheel rotating speed value are both effective values, judging whether the wheel rotating speed difference is larger than a preset rotating speed threshold value or not, and the duration time is larger than a preset time threshold value;
and if the wheel rotation speed difference value is larger than the preset rotation speed threshold value and the duration time is larger than the preset time threshold value, determining that the driving shaft motor is in a risk state.
In one embodiment, if the first wheel rotation speed value of the first coaxially driven wheel is within the interval range of [0,250] (in rpm), and the communication message of the first wheel rotation speed value is not lost, and the communication message is reported according to a period of 10 ms (or the communication message is not reported according to a period of 10 ms, and the abnormal duration of the non-reporting communication message is 50 ms), the first wheel rotation speed value is determined to be a valid value. If the first wheel speed value is not within the interval of [0,250], or the communication message of the first wheel speed value is lost, or the communication message is not lost but is not reported yet for more than 50 milliseconds, the first wheel speed value can be determined to be an invalid value.
Similarly, it may be determined whether the second wheel rotation speed value of the second coaxial driving wheel is a valid value by referring to the above method, and will not be described herein.
If both the first wheel speed value and the second wheel speed value are valid values, then a determination is continued as to whether the wheel speed difference between the first wheel speed value and the second wheel speed value is greater than a preset speed threshold (which may be set according to the characteristics of the drive shaft motor, typically set at 100 rpm), and the duration is greater than a preset time threshold (which may be flexibly set according to the actual situation, typically set at 500 milliseconds). If the wheel speed difference is greater than a predetermined speed threshold (e.g., 100 rpm) and the duration is greater than a predetermined time threshold (e.g., 500 milliseconds), then the drive axle motor may be determined to be in a risky condition. If the wheel speed difference is less than or equal to a preset speed threshold (e.g., 100 rpm), and/or if the duration is less than or equal to a preset time threshold (e.g., 500 milliseconds), it may be determined that the drive axle motor is not in a risky condition.
If it is determined that the driveshaft motor is not in a risky state, then no subsequent torque limit regulation logic is executed to ensure the power performance of the vehicle.
If the driving shaft motor is judged to be in a risk state, the subsequent torque limiting regulation logic is continuously executed so as to avoid the safety risk of the vehicle (such as the problems of broken shaft of the driving shaft, damage of the motor and the like) caused by violent driving of the vehicle in a special scene, and the reliability of driving and running is improved.
In some embodiments, calculating a motor speed value for the drive shaft motor includes:
acquiring a speed ratio signal of a driving shaft motor;
and calculating the motor rotation speed value of the drive shaft motor according to the first wheel rotation speed value, the second wheel rotation speed value and the speed ratio signal of the drive shaft motor.
As an example, assuming that a vehicle is a front-drive vehicle type, the vehicle controller may collect a speed ratio signal of a front axle motor in a motor system of the vehicle through an in-vehicle sensor. Then, the motor rotation speed value of the drive shaft motor (i.e., the front shaft motor) is converted according to the following formula (4).
A F ＝B F *C F (4)
In the formula (4), A F Representing the motor rotation speed value of the converted front axle motor, B F A speed ratio signal representing the front axle motor, C F The front axle drive wheel rotation speed value is indicated.
As another example, assuming that a certain vehicle type is a rear-drive vehicle type, the motor rotation speed value a of the rear-axle motor may be converted by referring to the conversion method of the motor rotation speed value of the front-axle motor described above R And will not be described in detail herein.
In some embodiments, the two-dimensional table of wheel speeds and motor torque limits is obtained by:
aiming at the same group of coaxial driving wheels, maintaining the wheel rotating speed difference between the first coaxial driving wheel and the second coaxial driving wheel unchanged, gradually increasing the electric driving torque value of a driving shaft motor shared by the first coaxial driving wheel and the second coaxial driving wheel, keeping a preset duration, and monitoring the damage condition of a motor shaft of the driving shaft motor;
Determining a driving motor torque limit value under each wheel rotating speed difference value according to the motor shaft damage condition of the driving shaft motor;
and creating a two-dimensional table of the wheel speed difference and the motor torque limit according to the corresponding relation between each wheel speed difference and the driving motor torque limit value.
As an example, taking a front axle power system as an example, a power bench is mounted, and a load test is performed on a front axle driving link of the whole vehicle power system (front axle power system) to obtain a driving motor torque limit value of the front axle driving link under each wheel rotation speed difference value. Specifically, in the test process, the wheel rotation speed difference between the first coaxial driving wheel (the first front axle driving wheel) and the second coaxial driving wheel (the second front axle driving wheel) is maintained unchanged, the electric driving torque value of the front axle motor is gradually increased, the preset duration (which can be flexibly set according to the actual situation) is maintained, and then whether the front axle driving link has damage signs is observed. Thus, the maximum driving torque limit value of the driving motor at each wheel rotation speed difference value can be measured.
And creating a two-dimensional table of the wheel speed difference and the motor torque limit according to the corresponding relation between each wheel speed difference and the driving motor torque limit value, as shown in table 1.
TABLE 1
| Wheel speed difference | ΔC f1 | ΔC f2 | ... |
| Front axle motor torque limit | T r-Limit1 | T r-Limit2 | ... |
In practical applications, after the wheel speed difference of the front axle power system is calculated, the front axle motor torque limit value corresponding to the wheel speed difference can be determined by looking up table 1.
Exemplary, a graph of the wheel speed difference of the front axle powertrain versus the front axle motor torque limit is shown in fig. 2. In fig. 2, the abscissa represents the wheel speed difference of the front axle power system, and the ordinate represents the front axle motor torque limit value. As can be seen from fig. 2, the wheel speed difference of the front axle power system is in the range of 50-200 rpm, the front axle motor torque limit value of the front axle motor is maximum and tends to be stable, when the wheel speed difference exceeds 200rpm, the front axle motor torque limit value tends to be obviously reduced, and then the front axle motor torque limit value of the front axle motor gradually decreases until approaching 0 along with the gradual increase of the wheel speed difference.
Similarly, the corresponding relation two-dimensional table and the graph of the wheel rotation speed difference value of the rear axle power system and the rear axle motor torque limit value can be obtained by referring to the method, and the description is omitted here. The change relation between the wheel rotating speed difference value of the rear axle power system and the rear axle motor torque limiting value of the rear axle motor is similar to the change relation between the wheel rotating speed difference value of the front axle power system and the front axle motor torque limiting value.
In some embodiments, determining the actual requested torque value of the drive motor of the vehicle powertrain from the vehicle requested torque value, the drive motor torque limit value, and the maximum electric drive out characteristic torque value of the vehicle includes:
and comparing the whole vehicle required torque value, the driving motor torque limit value and the maximum electric drive external characteristic torque value, and determining the minimum value of the whole vehicle required torque value, the driving motor torque limit value and the maximum electric drive external characteristic torque value as the driving motor actual required torque value of the whole vehicle power system.
As an example, assuming that the whole vehicle power system of a certain vehicle is a front axle power system, an external characteristic curve of the front axle motor may be derived according to a relationship between a motor rotation speed value of the front axle motor and a front axle driving torque, as shown in fig. 3. In fig. 3, the abscissa represents the motor rotation speed value of the front axle motor, and the ordinate represents the maximum electric drive external characteristic torque value of the front axle motor. As can be seen from fig. 3, when the motor rotation speed value of the front axle motor is in the range of 500 to 3000rpm, the maximum electric drive external characteristic torque value of the front axle motor is maximum and tends to be stable, when the motor rotation speed value exceeds 3000rpm, the maximum electric drive external characteristic torque value of the front axle motor has a significant decreasing trend, and then, as the motor rotation speed value gradually increases, the maximum electric drive external characteristic torque value of the front axle motor gradually decreases until approaching 0.
Similarly, the motor rotation speed value of the rear axle motor and the external characteristic curve of the rear axle motor of the rear axle power system can be determined by referring to the above method, and will not be described herein. The change relation between the motor rotation speed value of the rear axle motor and the maximum electric drive external characteristic torque value of the rear axle motor is similar to the change relation between the motor rotation speed value of the front axle motor and the maximum electric drive external characteristic torque value of the front axle motor.
In some embodiments, the entire vehicle powertrain of the vehicle is a four-drive power system, including a front axle powertrain and a rear axle powertrain; the driving motor torque limiting value comprises a front shaft motor torque limiting value corresponding to a front shaft power system and a rear shaft motor torque limiting value corresponding to a rear shaft power system; the maximum electric drive external characteristic torque value includes a front axle maximum electric drive external characteristic torque value corresponding to the front axle power system and a rear axle maximum electric drive external characteristic torque value corresponding to the rear axle power system.
Comparing the whole vehicle required torque value, the driving motor torque limit value and the maximum electric drive external characteristic torque value, and determining the minimum value of the whole vehicle required torque value, the driving motor torque limit value and the maximum electric drive external characteristic torque value as the driving motor actual required torque value of the whole vehicle power system, comprising:
Determining a torque split ratio between a front axle powertrain and a rear axle powertrain;
according to the torque distribution ratio and the whole vehicle required torque, calculating a front axle required torque distributed to a front axle power system and a rear axle required torque distributed to a rear axle power system;
for a front axle power system, comparing the front axle required torque, a front axle motor torque limit value and a front axle maximum electric drive external characteristic torque value, and determining the minimum value as a front axle motor actual required torque value;
for a rear axle power system, the magnitude of the rear axle required torque, the rear axle motor torque limit value and the maximum electric drive external characteristic torque value of the rear axle are compared, and the minimum value is determined as the rear axle motor actual required torque value.
As an example, with reference to fig. 4, assume that the whole vehicle power system of a certain vehicle is a four-drive power system including a front axle power system and a rear axle power system, the front axle power system including a front axle motor controller, a front axle motor controlled by the front axle motor controller, a first front axle drive wheel and a second front axle drive wheel connected to the front axle motor; the rear axle power system comprises a rear axle motor controller, a rear axle motor controlled by the rear axle motor controller, a first rear axle driving wheel and a second rear axle driving wheel which are connected with the rear axle motor.
For the front axle power system, the front axle motor torque limit value and the front axle maximum electric drive external characteristic torque value of the front axle power system can be determined according to the technical scheme provided by the embodiment.
For the rear axle power system, the rear axle motor torque limit value and the rear axle maximum electric drive external characteristic torque value of the rear axle power system can be determined according to the technical scheme provided by the embodiment.
When it is determined that both the front axle motor of the front axle power system and the rear axle motor of the rear axle power system are in a risk state, the front axle motor actual request torque value and the rear axle motor actual request torque value are calculated according to the following formula (5).
In the formula (5), E F-Act The actual request torque value of the front axle motor is represented, E represents the whole vehicle required torque, p represents the torque distribution proportion distributed to the front axle power system, T f-Limit Representing the torque limit value of the front axle motor, T 0-F Indicating the maximum electric drive external characteristic torque value of the front axle, E R-Act Representing the actual torque request value of the rear axle motor, (1-P) representing the torque distribution ratio, T, distributed to the rear axle powertrain r-Limit Represents the torque limit value of the rear axle motor, T 0-R The maximum electric drive external characteristic torque value of the rear axle is shown. E x P represents the front axle demand torque, and E x (1-P) represents the rear axle demand torque. The torque distribution ratio between the front axle power system and the rear axle power system is p: (1-P).
If a vehicle is a front-drive vehicle type, p=1 in the above formula (5); if a certain vehicle is of the rear-drive type, p=0 in the above formula (5).
Through the technical scheme, the vehicle controller can monitor the risk state of the vehicle power system in real time, when determining that the driving shaft motor is in the risk state, the torque limiting regulation and control measures of the embodiment of the application are timely adopted to carry out torque limiting control on the driving shaft motor so as to effectively avoid the vehicle safety risk (such as the occurrence of the problems of broken shaft of the driving shaft, damage of the motor and the like) caused by violent driving of the vehicle in a special scene, improve the reliability of driving and running, and simultaneously can consider the power performance and the safety performance of the vehicle. Meanwhile, the technical scheme of the embodiment of the application does not need to additionally increase hardware such as a hardware differential mechanism, so that the hardware cost can be reduced, and the manufacturing cost of the whole vehicle can be reduced.
Fig. 5 is a schematic diagram of torque limitation regulation and control of a drive shaft motor of a whole vehicle power system in the power system risk state monitoring method provided in the embodiment of the present application.
Through the technical scheme of the embodiment of the application, the torque of the driving shaft motor of the whole vehicle power system can be controlled below the maximum electric drive external characteristic torque value, the driving shaft motor is protected, the problems of broken driving shaft, motor damage and the like are avoided, the driving reliability can be improved, and the whole vehicle power performance and the safety performance can be considered.
Any combination of the above optional solutions may be adopted to form an optional embodiment of the present application, which is not described herein in detail.
The following are device embodiments of the present application, which may be used to perform method embodiments of the present application. For details not disclosed in the device embodiments of the present application, please refer to the method embodiments of the present application.
Fig. 6 is a schematic diagram of a risk status monitoring device for a power system according to an embodiment of the present application. As shown in fig. 6, the power system risk status monitoring apparatus includes:
a monitoring module 601 configured to monitor wheel speeds of one or two sets of coaxially driven wheels in a whole vehicle powertrain of a vehicle, wherein the one set of coaxially driven wheels shares a drive shaft motor, and the one set of coaxially driven wheels includes a first coaxially driven wheel and a second coaxially driven wheel;
a first calculation module 602 configured to calculate a wheel speed difference of the first and second coaxially driven wheels;
a second calculation module 603 configured to calculate a motor rotational speed value of the drive shaft motor if it is determined that the drive shaft motor is in a risk state based on the wheel rotational speed difference;
a query module 604 configured to query a maximum electric drive external characteristic torque value corresponding to the motor rotation speed value, and query a two-dimensional table of wheel rotation speed difference and motor torque limit to obtain a drive motor torque limit value corresponding to the wheel rotation speed difference;
A determining module 605 configured to determine an actual requested torque value of the driving motor of the whole vehicle power system according to the whole vehicle requested torque value, the driving motor torque limit value and the maximum electric drive external characteristic torque value of the vehicle;
the regulation module 606 is configured to regulate torque limits for a drive shaft motor of the overall vehicle powertrain based on the actual requested torque value for the drive motor.
According to the technical scheme provided by the embodiment of the application, the wheel speed of the coaxial driving wheels of the whole vehicle power system of the vehicle is analyzed, and the risk state of the driving shaft motor of the vehicle is determined based on the analysis result; when the driving shaft motor is in a risk state, calculating a motor rotating speed value of the driving shaft motor, further determining a maximum electric drive external characteristic torque value according to the motor rotating speed value, and determining a driving motor torque limit value according to a wheel rotating speed difference value; finally, combining the whole vehicle required torque, the maximum electric drive external characteristic torque value and the driving motor torque limit value to determine the actual required torque value of the driving motor; finally, torque limiting regulation and control are carried out on a driving shaft motor of the whole vehicle power system based on the actual request torque value of the driving motor; on one hand, hardware such as a hardware differential mechanism is not required to be additionally added, so that the hardware cost can be reduced, and the manufacturing cost of the whole vehicle can be reduced; on the other hand, the safety risk (such as the occurrence of the problems of broken drive shaft, motor damage and the like) of the vehicle caused by violent driving in a special scene can be effectively avoided, the driving reliability is improved, and meanwhile, the power performance and the safety performance of the whole vehicle can be considered.
In some embodiments, the first computing module 602 includes:
an acquisition unit configured to acquire a first wheel speed value of a first coaxially driven wheel, a second wheel speed value of a second coaxially driven wheel, and a tire radius value;
a first calculation unit configured to calculate a first wheel rotation speed value of a first coaxially driven wheel from the first wheel speed value and the tire radius value;
a second calculation unit configured to calculate a second wheel rotation speed value of a second coaxially driven wheel from the second wheel speed value and the tire radius value;
and a third calculation unit configured to calculate a wheel rotation speed difference value of the first coaxially driven wheel and the second coaxially driven wheel based on the first wheel rotation speed value and the second wheel rotation speed value.
In some embodiments, the second calculation module 603 described above includes a state determination unit configured to determine that the drive shaft motor is in a risky state based on the wheel speed difference.
The state determination unit includes:
a first determining component configured to determine whether a first wheel rotational speed value of the first coaxially driven wheel and a second wheel rotational speed value of the second coaxially driven wheel are valid values;
the second judging component is configured to judge whether the wheel rotating speed difference value is larger than a preset rotating speed threshold value or not and the duration time is larger than a preset time threshold value if the first wheel rotating speed value and the second wheel rotating speed value are both effective values;
And the state determining component is configured to determine that the driving shaft motor is in a risk state if the wheel rotation speed difference value is larger than a preset rotation speed threshold value and the duration time is larger than a preset time threshold value.
In some embodiments, the second calculation module 603 further includes a calculation unit configured to calculate a motor speed value of the drive shaft motor.
The calculation unit includes:
a signal acquisition assembly configured to acquire a speed ratio signal of the drive shaft motor;
a rotational speed calculation component configured to calculate a motor rotational speed value of the driveshaft motor based on the first wheel rotational speed value, the second wheel rotational speed value, and the speed ratio signal of the driveshaft motor.
In some embodiments, the two-dimensional table of wheel speeds and motor torque limits is obtained by:
aiming at the same group of coaxial driving wheels, maintaining the wheel rotating speed difference between the first coaxial driving wheel and the second coaxial driving wheel unchanged, gradually increasing the electric driving torque value of a driving shaft motor shared by the first coaxial driving wheel and the second coaxial driving wheel, keeping a preset duration, and monitoring the damage condition of a motor shaft of the driving shaft motor;
determining a driving motor torque limit value under each wheel rotating speed difference value according to the motor shaft damage condition of the driving shaft motor;
And creating a two-dimensional table of the wheel speed difference and the motor torque limit according to the corresponding relation between each wheel speed difference and the driving motor torque limit value.
In some embodiments, the determining module 605 includes:
the torque determining unit is configured to compare the whole vehicle required torque value, the driving motor torque limit value and the maximum electric drive external characteristic torque value, and determine the minimum value of the whole vehicle required torque value, the driving motor torque limit value and the maximum electric drive external characteristic torque value as the driving motor actual required torque value of the whole vehicle power system.
In some embodiments, the entire vehicle powertrain of the vehicle is a four-drive power system, including a front axle powertrain and a rear axle powertrain; the driving motor torque limiting value comprises a front shaft motor torque limiting value corresponding to a front shaft power system and a rear shaft motor torque limiting value corresponding to a rear shaft power system; the maximum electric drive external characteristic torque value includes a front axle maximum electric drive external characteristic torque value corresponding to the front axle power system and a rear axle maximum electric drive external characteristic torque value corresponding to the rear axle power system.
The torque determination unit includes:
a distribution ratio determining component configured to determine a torque distribution ratio between the front axle powertrain and the rear axle powertrain;
A torque calculation component configured to calculate a front axle demand torque allocated to the front axle power system and a rear axle demand torque allocated to the rear axle power system according to the torque distribution ratio and the vehicle demand torque;
a first torque determination component configured to compare, for a front axle power system, a front axle demand torque, a front axle motor torque limit value, a front axle maximum electric drive external characteristic torque value, and determine a minimum value thereof as a front axle motor actual demand torque value;
and the second torque determining component is configured to compare the magnitudes of the rear axle required torque, the rear axle motor torque limit value and the rear axle maximum electric drive external characteristic torque value for the rear axle power system, and determine the minimum value as the rear axle motor actual required torque value.
It should be understood that the sequence number of each step in the foregoing embodiment does not mean that the execution sequence of each process should be determined by the function and the internal logic of each process, and should not limit the implementation process of the embodiment of the present application in any way.
The embodiment of the application also provides a new energy automobile, which comprises a whole automobile controller and a whole automobile power system, wherein the whole automobile power system comprises a driving motor controller, a driving shaft motor and a transmission system;
The whole vehicle controller is used for realizing the power system risk state monitoring method provided by the embodiment so as to send the actual request torque value of the driving motor to the driving motor controller;
the driving motor controller is used for carrying out torque limiting regulation and control on the driving shaft motor through the transmission system according to the actual torque request value of the driving motor.
Fig. 7 is a schematic diagram of an electronic device 7 provided in an embodiment of the present application. As shown in fig. 7, the electronic device 7 of this embodiment includes: a processor 701, a memory 702 and a computer program 703 stored in the memory 702 and executable on the processor 701. The steps of the various method embodiments described above are implemented by the processor 701 when executing the computer program 703. Alternatively, the processor 701, when executing the computer program 703, performs the functions of the modules/units of the apparatus embodiments described above.
The electronic device 7 may be a desktop computer, a notebook computer, a palm computer, a cloud server, or the like. The electronic device 7 may include, but is not limited to, a processor 701 and a memory 702. It will be appreciated by those skilled in the art that fig. 7 is merely an example of the electronic device 7 and is not limiting of the electronic device 7 and may include more or fewer components than shown, or different components.
The processor 701 may be a central processing unit (Central Processing Unit, CPU) or other general purpose processor, digital signal processor (Digital Signal Processor, DSP), application specific integrated circuit (Application Specific Integrated Circuit, ASIC), field programmable gate array (Field-Programmable Gate Array, FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware components, or the like.
The memory 702 may be an internal storage unit of the electronic device 7, for example, a hard disk or a memory of the electronic device 7. The memory 702 may also be an external storage device of the electronic device 7, for example, a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash Card (Flash Card) or the like provided on the electronic device 7. The memory 702 may also include both internal storage units and external storage devices of the electronic device 7. The memory 702 is used to store computer programs and other programs and data required by the electronic device.
It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-described division of the functional units and modules is illustrated, and in practical application, the above-described functional distribution may be performed by different functional units and modules according to needs, i.e. the internal structure of the apparatus is divided into different functional units or modules to perform all or part of the above-described functions. The functional units and modules in the embodiment may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit, where the integrated units may be implemented in a form of hardware or a form of a software functional unit.
The integrated modules/units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a readable storage medium (e.g., a computer readable storage medium). Based on such understanding, the present application implements all or part of the flow in the methods of the above embodiments, or may be implemented by a computer program to instruct related hardware, and the computer program may be stored in a computer readable storage medium, where the computer program may implement the steps of the respective method embodiments described above when executed by a processor. The computer program may comprise computer program code, which may be in source code form, object code form, executable file or in some intermediate form, etc. The computer readable storage medium may include: any entity or device capable of carrying computer program code, a recording medium, a U disk, a removable hard disk, a magnetic disk, an optical disk, a computer Memory, a Read-Only Memory (ROM), a random access Memory (Random Access Memory, RAM), an electrical carrier signal, a telecommunications signal, a software distribution medium, and so forth.
The above embodiments are only for illustrating the technical solution of the present application, and are not limiting thereof; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application, and are intended to be included in the scope of the present application.
Claims (10)
1. A power system risk status monitoring method, comprising:
monitoring wheel speeds of one or two groups of coaxial driving wheels in a whole vehicle power system of a vehicle, wherein the coaxial driving wheels share a driving shaft motor, and the coaxial driving wheels comprise a first coaxial driving wheel and a second coaxial driving wheel;
calculating a wheel speed difference between the first and second coaxially driven wheels;
if the driving shaft motor is in a risk state based on the wheel rotating speed difference value, calculating a motor rotating speed value of the driving shaft motor;
inquiring a maximum electric drive external characteristic torque value corresponding to the motor rotation speed value, inquiring a two-dimensional table of wheel rotation speed difference and motor torque limit to obtain a driving motor torque limit value corresponding to the wheel rotation speed difference;
determining an actual request torque value of a driving motor of the whole vehicle power system according to the whole vehicle request torque value, the driving motor torque limit value and the maximum electric drive external characteristic torque value of the vehicle;
and according to the actual torque request value of the driving motor, performing torque limiting regulation and control on the driving shaft motor of the whole vehicle power system.
2. The method of claim 1, wherein calculating a wheel speed difference for the first and second coaxially driven wheels comprises:
acquiring a first wheel speed value of the first coaxial driving wheel, a second wheel speed value of the second coaxial driving wheel and a tire radius value;
calculating a first wheel speed value of the first coaxially driven wheel according to the first wheel speed value and the tire radius value;
calculating a second wheel speed value of the second coaxially driven wheel based on the second wheel speed value and the tire radius value;
and calculating a wheel speed difference value of the first coaxial driving wheel and the second coaxial driving wheel according to the first wheel speed value and the second wheel speed value.
3. The method of claim 2, wherein determining that the drive shaft motor is in a risky state based on the wheel speed difference comprises:
judging whether a first wheel rotation speed value of the first coaxial driving wheel and a second wheel rotation speed value of the second coaxial driving wheel are effective values or not;
if the first wheel rotating speed value and the second wheel rotating speed value are both effective values, judging whether the wheel rotating speed difference value is larger than a preset rotating speed threshold value or not and the duration time is larger than a preset time threshold value;
And if the wheel rotation speed difference value is larger than a preset rotation speed threshold value and the duration time is larger than a preset time threshold value, determining that the driving shaft motor is in a risk state.
4. A method according to claim 2 or 3, wherein calculating a motor speed value of the drive shaft motor comprises:
acquiring a speed ratio signal of the driving shaft motor;
and calculating the motor rotating speed value of the driving shaft motor according to the first wheel rotating speed value, the second wheel rotating speed value and the speed ratio signal of the driving shaft motor.
5. The method of claim 1, wherein the two-dimensional table of wheel speeds and motor torque limits is obtained by:
aiming at the same group of coaxial driving wheels, maintaining the wheel rotating speed difference between the first coaxial driving wheel and the second coaxial driving wheel unchanged, gradually increasing the electric driving torque value of a driving shaft motor shared by the first coaxial driving wheel and the second coaxial driving wheel, maintaining a preset duration, and monitoring the damage condition of a motor shaft of the driving shaft motor;
determining a driving motor torque limit value under each wheel rotating speed difference value according to the motor shaft damage condition of the driving shaft motor;
And creating a two-dimensional table of the wheel speed difference and the motor torque limit according to the corresponding relation between each wheel speed difference and the driving motor torque limit value.
6. The method of claim 1, wherein determining the actual requested torque value for the drive motor of the vehicle powertrain based on the vehicle demand torque value, the drive motor torque limit value, and the maximum electric drive out characteristic torque value comprises:
and comparing the whole vehicle required torque value, the driving motor torque limit value and the maximum electric drive external characteristic torque value, and determining the minimum value of the whole vehicle required torque value, the driving motor torque limit value and the maximum electric drive external characteristic torque value as the driving motor actual required torque value of the whole vehicle power system.
7. The method of claim 6, wherein the vehicle's entire vehicle powertrain is a four-drive power system, the four-drive power system comprising a front axle powertrain and a rear axle powertrain; the driving motor torque limiting value comprises a front shaft motor torque limiting value corresponding to the front shaft power system and a rear shaft motor torque limiting value corresponding to the rear shaft power system; the maximum electric drive external characteristic torque value comprises a front axle maximum electric drive external characteristic torque value corresponding to the front axle power system and a rear axle maximum electric drive external characteristic torque value corresponding to the rear axle power system;
Comparing the whole vehicle required torque value, the driving motor torque limit value and the maximum electric drive external characteristic torque value, and determining the minimum value of the whole vehicle required torque value, the driving motor torque limit value and the maximum electric drive external characteristic torque value as the driving motor actual required torque value of the whole vehicle power system, wherein the method comprises the following steps:
determining a torque split ratio between the front axle powertrain and the rear axle powertrain;
according to the torque distribution ratio and the whole vehicle required torque, calculating a front axle required torque distributed to the front axle power system and a rear axle required torque distributed to the rear axle power system;
comparing the required torque of the front axle, the torque limit value of the front axle motor and the maximum electric drive external characteristic torque value of the front axle aiming at the front axle power system, and determining the minimum value as the actual required torque value of the front axle motor;
and comparing the rear axle required torque, the rear axle motor torque limit value and the rear axle maximum electric drive external characteristic torque value aiming at the rear axle power system, and determining the minimum value as the rear axle motor actual required torque value.
8. A power system risk status monitoring device, comprising:
A monitoring module configured to monitor wheel speeds of one or two sets of coaxially driven wheels in a whole vehicle powertrain of a vehicle, wherein the one set of coaxially driven wheels share a drive shaft motor, and the one set of coaxially driven wheels includes a first coaxially driven wheel and a second coaxially driven wheel;
a first calculation module configured to calculate a wheel speed difference of the first and second coaxially driven wheels;
a second calculation module configured to calculate a motor rotational speed value of the drive shaft motor if it is determined that the drive shaft motor is in a risk state based on the wheel rotational speed difference;
the inquiring module is configured to inquire a maximum electric drive external characteristic torque value corresponding to the motor rotating speed value, inquire a two-dimensional table of wheel rotating speed difference and motor torque limit, and obtain a driving motor torque limit value corresponding to the wheel rotating speed difference;
the determining module is configured to determine an actual request torque value of a driving motor of the whole vehicle power system according to the whole vehicle request torque value, the driving motor torque limit value and the maximum electric drive external characteristic torque value of the vehicle;
and the regulation and control module is configured to regulate and control the torque limitation of the driving shaft motor of the whole vehicle power system according to the actual request torque value of the driving motor.
9. The new energy automobile is characterized by comprising a whole automobile controller and a whole automobile power system, wherein the whole automobile power system comprises a driving motor controller, a driving shaft motor and a transmission system;
the whole vehicle controller is used for realizing the power system risk state monitoring method according to any one of claims 1 to 7 so as to send the actual request torque value of the driving motor to the driving motor controller;
the driving motor controller is used for carrying out torque limiting regulation and control on the driving shaft motor through the transmission system according to the actual torque request value of the driving motor.
10. A readable storage medium storing a computer program, characterized in that the computer program when executed by a processor implements the steps of the method according to any one of claims 1 to 7.
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| CN202311567830.8A CN117400737A (en) | 2023-11-21 | 2023-11-21 | Power system risk state monitoring method and device and new energy automobile |
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| CN202311567830.8A CN117400737A (en) | 2023-11-21 | 2023-11-21 | Power system risk state monitoring method and device and new energy automobile |
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