New Energy Vehicle Torque Zero-Crossing Control Method, System, New Energy Vehicle and Storage Medium

Abstract

The present invention discloses a torque zero-crossing control method, system, new energy vehicle and storage medium for a new energy vehicle, including: when it is determined that the engine torque zero-crossing enabling condition is met, calculating the actual change rate of the current engine demanded torque and the allowable change rate of the engine demanded torque, and using the allowable change rate of the engine demanded torque to limit the actual change rate of the current engine demanded torque to obtain the torque after engine zero-crossing processing; when it is determined that the motor torque zero-crossing enabling condition is met, calculating the actual change rate of the current motor demanded torque and the allowable change rate of the motor demanded torque, and using the allowable change rate of the motor demanded torque to limit the actual change rate of the current motor demanded torque to obtain the torque after motor zero-crossing processing. The present invention can control the torque of the drive motor or the engine to cross zero precisely and slowly during the TipIn / TipOut process, avoiding the problem of vehicle body shaking caused by tooth impact.

Description

Technical Field

[0001] The present invention relates to the technical field of torque zero-crossing processing control for new energy vehicles, and particularly to a torque zero-crossing control method, system, new energy vehicle and storage medium for new energy vehicles. Background Art

[0002] During driving, the control system generally needs to quickly respond to the driver's intention, that is, the driving torque should follow the driver's (throttle) demand torque as quickly as possible. However, in range-extended hybrid or pure electric vehicles, the clutch or torque converter in the traditional vehicle automatic transmission is cancelled, and the drive motor and the wheels are rigidly connected through a gear set, spline and shaft, etc. to the wheels. The splines, gears, etc. in the hardware connection of the power transmission chain are all clearance fits, and there are inevitably clearances. When the driver performs TipIn / TipOut (quickly step on the accelerator / quickly release the accelerator) operations, the positive and negative switching of the driving torque causes impacts of the splines and gears, resulting in vehicle shock and thus vehicle jitter.

[0003] For example, a method for optimizing the zero-crossing impact of the motor torque of a new energy vehicle disclosed in patent document CN109159673A. In this method, it is proposed that the zero-crossing of the motor torque includes the zero-crossing from positive torque to negative torque and the zero-crossing from negative torque to positive torque of the motor. An zero-crossing detection algorithm is used to detect the zero-crossing point of the torque. After detecting the zero-crossing point of the torque, the slope of the torque rise or fall is restricted to change the original change trajectory of the torque, so as to achieve the purpose of reducing the zero-crossing impact of the torque and improving the driving comfort. However, the above method has three deficiencies: (1) The zero-crossing detection of the torque is too mechanical. It simply judges the zero-crossing point of the input torque based on the different signs of the input torque at the previous and next moments. Such detection is not accurate because the impact does not necessarily occur at the zero point, but may also occur near the zero point; (2) The detection algorithm does not consider safety factors. Because when the vehicle is in an emergency, safety controllers such as ESP (Electronic Stability Program) and AEB (Automatic Emergency Braking System) start to intervene, and the engine and motor must quickly respond to the input torque and cannot perform zero-crossing processing; (3) It does not consider whether the torque after zero-crossing processing exceeds the discharge capacity of the battery. Because the zero-crossing processing of the torque has a delay, resulting in the torque not being able to follow the demand torque in time under the condition of restricting the change rate, which is likely to cause the battery to report a fault and cut off the high voltage, resulting in the vehicle losing power.

[0004] Therefore, it is necessary to develop a torque zero-crossing control method, system, new energy vehicle and storage medium for new energy vehicles. Summary of the Invention

[0005] The purpose of the present invention is to provide a torque zero-crossing control method, system, new energy vehicle and storage medium for new energy vehicles, which can control the torque of the drive motor or engine to accurately and slowly cross zero during TipIn / TipOut, so as to avoid the problem of vehicle body shaking caused by tooth impact.

[0006] In the first aspect, a torque zero-crossing control method for a new energy vehicle according to the present invention includes the following steps:

[0007] When it is judged that the engine torque zero-crossing enabling condition is met, calculate the actual change rate of the current engine demand torque and the allowable change rate of the engine demand torque, and use the allowable change rate of the engine demand torque to limit the actual change rate of the current engine demand torque to obtain the torque after engine zero-crossing processing;

[0008] When it is judged that the motor torque zero-crossing enabling condition is met, calculate the actual change rate of the current motor demand torque and the allowable change rate of the motor demand torque, and use the allowable change rate of the motor demand torque to limit the actual change rate of the current motor demand torque to obtain the torque after motor zero-crossing processing.

[0009] Optionally, using the allowable change rate of the engine demand torque to limit the actual change rate of the current engine demand torque is specifically:

[0010] Compare the allowable change rate of the engine demand torque with the actual change rate of the current engine demand torque, and take the smaller value of the two as the engine torque change rate.

[0011] Optionally, using the allowable change rate of the motor demand torque to limit the actual change rate of the current motor demand torque is specifically:

[0012] Compare the allowable change rate of the motor demand torque with the actual change rate of the current motor demand torque, and take the smaller value of the two as the motor torque change rate.

[0013] Optionally, the judgment of the engine torque zero-crossing enabling condition is specifically:

[0014] When it is judged that there is no intervention from ESP and AEB, the clutch state is in the closed state, and the engine demand torque is near zero, it is judged that the engine torque zero-crossing enabling condition is met.

[0015] Optionally, the judgment of the motor torque zero-crossing enabling condition is specifically:

[0016] When it is judged that there is no intervention from ESP and AEB, and the motor demand torque is near zero, it is judged that the motor torque zero-crossing enabling condition is met.

[0017] Optionally, the actual change rate of the current engine demand torque is specifically:

[0018] Obtain the engine demand torque and the demand torque after the engine crosses zero in the previous cycle;

[0019] Calculate the actual change rate of the current engine demand torque based on the engine demand torque and the demand torque after the engine crosses zero in the previous cycle.

[0020] Optionally, the actual change rate of the current motor demand torque is specifically:

[0021] Obtain the motor demand torque and the demand torque after the motor crosses zero in the previous cycle;

[0022] Calculate the actual change rate of the current motor demand torque based on the motor demand torque and the demand torque after the motor crosses zero in the previous cycle.

[0023] In a second aspect, a new energy vehicle torque zero-crossing control system according to the present invention includes a memory and a controller. The memory stores a computer-readable program, and when the computer-readable program is called, it can execute the steps of the new energy vehicle torque zero-crossing control method according to the present invention.

[0024] In a third aspect, a new energy vehicle according to the present invention adopts the new energy vehicle torque zero-crossing control system according to the present invention.

[0025] In a fourth aspect, a storage medium according to the present invention stores a computer-readable program, and when the computer-readable program is called, it can execute the steps of the new energy vehicle torque zero-crossing control method according to the present invention.

[0026] The present invention has the following advantages: The present invention designs a more accurate and comprehensive input torque zero-crossing detection method, and can accurately limit the change rate of the input torque near zero, ensuring that the torque after zero-crossing processing is within the battery discharge capacity range, fundamentally solving the problems of vehicle body jitter and impact of new energy vehicles (including hybrid and pure electric vehicles). BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0028] Figure 1 is a schematic diagram of the torque zero-crossing processing control method in this embodiment;

[0029] Figure 2 is a schematic diagram of the configuration of a hybrid vehicle in this embodiment;

[0030] Figure 3 It is a schematic diagram of the configuration of a pure electric vehicle in this embodiment;

[0031] Figure 4 It is the control flow chart of this embodiment. Specific implementation manners

[0032] The present invention will be described in detail below with reference to the accompanying drawings.

[0033] As Figure 1 shown, in this embodiment, a method for controlling the torque zero crossing of a new energy vehicle includes the following steps:

[0034] When it is determined that the engine torque zero crossing is enabled, calculate the actual change rate of the current engine demand torque and the allowable change rate of the engine demand torque, and use the allowable change rate of the engine demand torque to limit the actual change rate of the current engine demand torque to obtain the torque after the engine zero crossing processing;

[0035] When it is determined that the motor torque zero crossing is enabled, calculate the actual change rate of the current motor demand torque and the allowable change rate of the motor demand torque, and use the allowable change rate of the motor demand torque to limit the actual change rate of the current motor demand torque to obtain the torque after the motor zero crossing processing.

[0036] As Figure 2 shown, in this embodiment, a method for controlling the torque zero crossing of a new energy vehicle includes: working condition identification (i.e., calculation of torque zero crossing function enabling), calculation of torque change rate capability, and torque change rate limiting algorithm. The working condition identification is the enabling condition of the torque change rate limiting algorithm. Among them, it is judged whether there is a safety protection intervention through the safety protection enabling signal of ESP / AEB, and it is judged whether the engine is participating in driving through the clutch state. The calculation of the torque change rate capability is to calculate the allowable change rate of the engine / motor demand torque according to the engine / motor demand torque requirement and the vehicle speed. The torque change rate limiting algorithm is to detect the current actual torque change rate and use the allowable torque change rate to limit the torque change rates of the motor and the engine; that is, compare the allowable change rate of the engine demand torque with the actual change rate of the current engine demand torque, and take the smaller value of the two as the engine torque change rate; compare the allowable change rate of the motor demand torque with the actual change rate of the current motor demand torque, and take the smaller value of the two as the motor torque change rate.

[0037] As Figure 4 shown, in this embodiment, a method for controlling the torque zero crossing of a new energy vehicle includes the following steps:

[0038] S1: Enter the state where the vehicle startup is successful. In this state, the power system is activated, and the vehicle enters the drivable state.

[0039] S2: Determine whether there is ESP or AEB intervention. If so, return to step S1; otherwise, proceed to step S3.

[0040] S3: Determine the clutch state. If the clutch is disengaged, proceed to step S5; otherwise, proceed to steps S4 and S5. Here, the clutch being disengaged represents that the system is in the extended - range hybrid mode, and the clutch being engaged represents that the system is in the hybrid drive mode.

[0041] S4: Determine whether the engine demand torque is near zero. If so, proceed to step S6; otherwise, return to step S1. Here, the interval [X1, X2] is defined as near zero, where X1 and X2 are calibration values.

[0042] S5: Determine whether the motor demand torque is near zero. If so, proceed to step S7; otherwise, return to step S1. Here, the interval [X3, X4] is defined as near zero, where X3 and X4 are calibration values.

[0043] S6: Enable the engine torque to cross zero and proceed to step S10.

[0044] S7: Enable the motor torque to cross zero and proceed to step S11.

[0045] S8: Calculate the allowable engine demand torque change rate, that is, dynamically calculate the allowable engine demand torque change rate based on the vehicle speed and the engine demand torque, and proceed to step S12.

[0046] S9: Calculate the allowable motor demand torque change rate, that is, dynamically calculate the allowable motor demand torque change rate based on the vehicle speed and the motor demand torque, and proceed to step S13.

[0047] S10: Calculate the actual change rate of the current engine demand torque and proceed to step S12.

[0048] The formula for calculating the actual change rate of the current engine demand torque is as follows:

[0049] Actual change rate of current engine demand torque = (engine demand torque - engine demand torque after zero - crossing in the previous cycle) * 100;

[0050] Where, one cycle is 10 ms.

[0051] S11: Calculate the actual change rate of the current motor demand torque and proceed to step S13.

[0052] The formula for calculating the actual change rate of the current motor demand torque is as follows:

[0053] Actual change rate of current motor demand torque = (motor demand torque - motor demand torque after zero - crossing in the previous cycle) * 100;

[0054] Among them, one cycle is 10 ms.

[0055] S12: Compare the engine demand torque change rate, that is, compare the actual change rate of the current engine demand torque with the allowable engine demand torque change rate, and enter step S14.

[0056] S13: Compare the motor demand torque change rate, that is, compare the actual change rate of the current motor demand torque with the allowable motor demand torque change rate, and enter step S15.

[0057] S14: Limit the engine demand torque change rate, that is, use the allowable engine demand torque change rate to limit the actual change rate of the current engine demand torque, and enter step S16.

[0058] S15: Limit the motor demand torque change rate, that is, use the allowable motor demand torque change rate to limit the actual change rate of the current motor demand torque, and enter step S17.

[0059] S16: Obtain the torque after the engine zero-crossing processing, and enter step S19.

[0060] S17: Obtain the torque after the motor zero-crossing processing, and enter step S18.

[0061] S18: Use the battery discharge capacity to perform boundary limit on the torque after the motor zero-crossing processing, and enter step S19.

[0062] S19: End.

[0063] In this embodiment, a torque zero-crossing control system for a new energy vehicle includes a memory and a controller. The memory stores a computer-readable program. When the computer-readable program is called, it can execute the steps of the torque zero-crossing control method for a new energy vehicle as described in this embodiment.

[0064] In this embodiment, a new energy vehicle adopts the torque zero-crossing control system for a new energy vehicle as described in this embodiment.

[0065] As Figure 2 shown, it is a vehicle with a hybrid configuration. The power system of this configuration includes, but is not limited to, components such as a PCU, an engine, a first motor, a second motor, a battery, a clutch, a first controller, and a second controller. This power system can achieve modes such as hybrid power, pure electric, and range-extended drive.

[0066] As Figure 3 shown, it is a vehicle with a pure electric configuration. The power system of this configuration includes, but is not limited to, components such as a drive motor, a reducer, and a main reducer. This power system can achieve modes such as pure electric.

[0067] In this embodiment, a storage medium stores a computer-readable program, and when the computer-readable program is called, it can execute the steps of the new energy vehicle torque zero-crossing control method described in this embodiment.

[0068] It should be noted that the storage medium described in this embodiment can be a computer-readable signal medium, a computer-readable storage medium, or any combination of the two. A computer-readable storage medium can be, for example, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. More specific examples of the computer-readable storage medium may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a flash memory, an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this embodiment, the computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, which carries the computer-readable computer program. Such a propagated data signal can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. The computer-readable signal medium can also be any computer-readable medium other than the computer-readable storage medium, which can send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device. The computer program contained on the computer-readable medium can be transmitted by any suitable medium, including but not limited to: wireless, wired, etc., or any suitable combination of the above.

[0069] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A method for controlling the torque of a new energy vehicle to cross zero, comprising the following steps: When it is determined that the engine torque zero-crossing enabling condition is met, calculate the actual change rate of the current engine demand torque and the allowable change rate of the engine demand torque, and use the allowable change rate of the engine demand torque to limit the actual change rate of the current engine demand torque to obtain the torque after the engine zero-crossing processing; When it is determined that the motor torque zero-crossing enabling condition is met, calculate the actual change rate of the current motor demand torque and the allowable change rate of the motor demand torque, and use the allowable change rate of the motor demand torque to limit the actual change rate of the current motor demand torque to obtain the torque after the motor zero-crossing processing; The actual change rate of the current engine demand torque is specifically: Obtain the engine demand torque and the engine demand torque after zero-crossing in the previous cycle; Calculate the actual change rate of the current engine demand torque based on the engine demand torque and the engine demand torque after zero-crossing in the previous cycle; The actual change rate of the current motor demand torque is specifically: Obtain the motor demand torque and the motor demand torque after zero-crossing in the previous cycle; Calculate the actual change rate of the current motor demand torque based on the motor demand torque and the motor demand torque after zero-crossing in the previous cycle.

2. The new energy vehicle torque zero-crossing control method according to claim 1, characterized in that: Using the allowable change rate of the engine demand torque to limit the actual change rate of the current engine demand torque is specifically: Compare the allowable change rate of the engine demand torque with the actual change rate of the current engine demand torque, and take the smaller value of the two as the engine torque change rate.

3. The torque zero-crossing control method for new energy vehicles according to claim 1, characterized in that: Using the allowable change rate of the motor demand torque to limit the actual change rate of the current motor demand torque is specifically: Compare the allowable change rate of the motor demand torque with the actual change rate of the current motor demand torque, and take the smaller value of the two as the motor torque change rate.

4. The new energy vehicle torque zero-crossing control method according to claim 1, wherein: The determination of the engine torque zero-crossing enabling condition is specifically: When it is determined that there is no intervention from ESP and AEB, the clutch state is in the closed state, and the engine demand torque is near zero, it is determined that the engine torque zero-crossing enabling condition is met.

5. The torque zero-crossing control method for a new energy vehicle according to claim 1, characterized in that: The determination of the motor torque zero-crossing enabling condition is specifically: When it is determined that there is no intervention from ESP and AEB, and the motor demand torque is near zero, it is determined that the motor torque zero-crossing enabling condition is met.

6. A torque zero-crossing control system for a new energy vehicle, characterized in that: It includes a memory and a controller. The memory stores a computer-readable program, and when the computer-readable program is called, it can execute the steps of the method for controlling the torque of a new energy vehicle to cross zero according to any one of claims 1 to 5.

7. A new energy vehicle, characterized in that: Adopt the new energy vehicle torque zero-crossing control system according to claim 6.

8. A storage medium, characterized in that: It stores a computer-readable program, and when the computer-readable program is called, it can execute the steps of the method for controlling the torque of a new energy vehicle to cross zero according to any one of claims 1 to 5.

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