Gearbox gear shifting control method and system and electric vehicle

Abstract

The invention belongs to the technical field of vehicle transmission control, and relates to a gearbox gear shifting control method and system and an electric vehicle. The method is applied to a gearbox gear shifting control system and comprises the steps that an MCU collects the rotating speed of a gearbox gear and sends the rotating speed to a VCU controller; the VCU controller calculates a theoretical torque value based on the rotational inertia of the gearbox gear and the rotational speed variation, and calculates the maximum lag time from the rotational speed collected by the MCU to the response torque; a maximum estimated inertia torque value is obtained based on the maximum lag time, so that a torque instruction is generated and sent to the MCU; and the MCU controls the motor to respond to the torque instruction until the gearbox is out of gear, so that gear shifting is carried out through the gear shifting mechanism. According to the scheme, the maximum lag time caused by information transmission and data processing between the MCU and the VCU controller is considered, the theoretical torque value is further corrected, and the problem that after the motor torque is controlled based on the theoretical torque value, gear disengaging cannot be achieved is effectively solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle transmission control, in particular to a gearbox shifting control method and system and an electric vehicle. BACKGROUND

[0002] With the development of vehicle automation and intelligent technology, the optimization of gearbox shifting logic has become a core problem to improve driving smoothness and reliability.

[0003] The shifting strategy in the prior art is to collect the speed of the gearbox gear by the MCU in real time, and then calculate the theoretical torque value required for the gearbox to disengage based on the collected speed and the existing inertia torque calculation formula by the VCU controller, and then the MCU controls the torque of the motor based on the theoretical torque value, so as to achieve the purpose of disengagement. However, since the speed of the gearbox gear fluctuates in real time, and the information transmission between the MCU and the VCU controller requires time, these information transmission delays and speed fluctuations will cause the calculated inertia torque to be not the actual torque value required for the gearbox to disengage, and thus the adjusted motor torque still cannot make the gearbox disengage, resulting in disengagement difficulty and inability to shift.

[0004] In summary, the prior art has the problem that the calculated theoretical torque cannot reach the actual torque required for the gearbox to disengage when shifting, which further causes disengagement difficulty and inability to shift. SUMMARY

[0005] Therefore, the technical problem to be solved by the present application is to overcome the problem in the prior art that the calculated theoretical torque cannot reach the actual torque required for the gearbox to disengage when shifting, which further causes disengagement difficulty and inability to shift.

[0006] To solve the above technical problems, the present application provides a gearbox shifting control method applied to a gearbox shifting control system, the gearbox shifting control system comprising an MCU and a VCU controller, comprising: The MCU collects the speed of the gearbox gear in real time and sends it to the VCU controller; The VCU controller calculates a theoretical torque value based on the moment of inertia and the speed change of the gearbox gear, and calculates the maximum lag time from the speed collected by the MCU to the response torque; based on the maximum lag time and the theoretical torque value, a maximum inertia torque value is obtained, so as to generate a torque instruction and send it to the MCU; The MCU controls the motor response torque instruction until the gearbox disengages, so as to shift through the shifting mechanism.

[0007] Preferably, the VCU controller calculates the theoretical torque value based on the moment of inertia and the speed change of the gearbox gear, comprising: The speed variation of the gearbox gear is calculated based on the speed of the gearbox gear collected and transmitted by the MCU in real time. The angular speed variation of the gearbox gear is calculated based on the speed variation of the gearbox gear. The angular acceleration of the gearbox gear is calculated based on the angular speed variation of the gearbox gear. The theoretical torque value is obtained based on the product of the angular acceleration of the gearbox gear and the moment of inertia.

[0008] Preferably, the calculation formula of the theoretical torque value is: , Wherein, represents the theoretical torque value; represents the moment of inertia; represents the angular acceleration; represents the angular speed variation; represents the speed variation of the gearbox gear; represents the time interval.

[0009] Preferably, the maximum lag time of the MCU collecting the speed to the response torque is calculated, including: The maximum lag time is obtained based on the sum of the speed collection time of the MCU, the time for the MCU to transmit the speed to the VCU controller, the calculation time of the maximum inertia torque value, and the time for the VCU controller to transmit the torque instruction to the MCU.

[0010] Preferably, the maximum inertia torque value is obtained based on the maximum lag time and the theoretical torque value, including: The maximum estimated speed variation value of the gearbox gear is calculated based on the maximum lag time and the speed variation. The maximum angular speed variation of the gearbox gear is calculated based on the maximum estimated speed variation value of the gearbox gear. The maximum angular acceleration of the gearbox gear is calculated based on the maximum angular speed variation of the gearbox gear. The maximum inertia torque value is obtained based on the product of the maximum angular acceleration of the gearbox gear and the moment of inertia.

[0011] Preferably, the calculation formula of the maximum estimated speed variation value of the gearbox gear is: , Wherein, represents the maximum estimated speed variation value of the gearbox gear; represents the speed variation of the gearbox gear; represents the speed collection time of the MCU; represents the time for the MCU to transmit the speed to the VCU controller; a calculation time of a maximum inertia torque value; a time for the VCU controller to transmit the torque instruction to the MCU; a calculation formula of the maximum inertia torque value is: , wherein, a maximum inertia torque value; a theoretical torque value.

[0012] Preferably, the torque instruction comprises: controlling the motor torque to increase from the theoretical torque value according to a preset gradient until the motor torque equals the maximum inertia torque value; controlling the motor torque to decrease from the maximum inertia torque value according to a preset gradient until the motor torque equals the theoretical torque value.

[0013] Preferably, the preset gradient equals a maximum matrix tolerance deviation of the gearshift.

[0014] The application also provides a gearshift control system for realizing the above-mentioned gearshift control method, comprising: an MCU, which is in communication connection with the gearbox, the VCU controller and the motor, is used to collect the rotating speed of the gearbox gear in real time and send it to the VCU controller, control the motor to respond to the torque instruction until the gearbox is out of gear, so as to shift through the gearshift mechanism; a VCU controller, which is used to calculate the theoretical torque value based on the moment of inertia and the rotating speed change of the gearbox gear, and calculate the maximum lag time of the rotating speed collected by the MCU to the response torque; obtain the maximum inertia torque value based on the maximum lag time and the theoretical torque value, so as to generate the torque instruction and send it to the MCU.

[0015] The application also provides an electric vehicle, which comprises the above-mentioned gearshift control system.

[0016] The gearbox shift control method provided in the application considers the maximum lag time caused by information transmission and data processing between the MCU and the VCU controller after calculating the theoretical torque value based on the rotation speed of the gearbox gear, and further calculates the maximum rotation speed value of the gearbox gear within the maximum lag time, thereby correcting the theoretical torque value to obtain the maximum inertia torque value required for the gearbox to shift out of gear under the influence of information transmission processing lag and rotation speed fluctuation. Since the torque required for the gearbox to shift out of gear will be between the theoretical torque value and the maximum inertia torque value, after calculating the maximum inertia torque value, only the motor torque needs to be controlled to change between the theoretical torque value and the maximum inertia torque value, so as to find a value that can meet the torque value required for the gearbox to shift out of gear, thereby achieving the gearbox to shift out of gear, and effectively solving the problem that the motor torque cannot be directly controlled based on the theoretical torque value in the prior art. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to make the content of the application more easily understood, the application will be further described in detail below according to specific embodiments of the application and in conjunction with the drawings, in which: Figure 1 The flow chart of the gearbox shift control method provided in the application; Figure 2 The structural schematic diagram of the gearbox shift control system provided in the application. DETAILED DESCRIPTION

[0018] The application will be further described below in conjunction with the drawings and specific embodiments, so that those skilled in the art can better understand the application and implement it, but the embodiments are not limiting to the application.

[0019] The gearbox needs to be uncoupled before shifting to use the shift mechanism, otherwise the gear will be stuck. The torque required for the gearbox to uncouple is reached by the motor. In the prior art, the VCU controller directly calculates the inertia torque based on the speed of the gearbox gear collected by the MCU, and further controls the motor torque to reach the calculated inertia torque value to uncouple. However, during the calculation of the inertia torque and the control of the motor torque, each link needs a certain time, that is, the information processing and transmission time. During this time, the speed of the gearbox gear may change, especially in uphill and downhill conditions. The gravity of the system (such as an electric vehicle) carried by the gearbox acts on the gearbox gear in the opposite direction through the transmission system, causing the speed of the gearbox gear to change, and the torque required for uncoupling also increases. At this time, the inertia torque is still calculated based on the speed collected by the MCU, which makes the calculated inertia torque value unable to reach the actual torque required for uncoupling, and the uncoupling problem occurs. To solve this problem, the application provides a gearbox shifting control method.

[0020] Please refer to Figure 1 , Figure 1 The gearbox shifting control method provided by the application is shown in the flow chart. The method is applied to a gearbox shifting control system, as shown in Figure 2 The gearbox shifting control system MCU and VCU controller are connected to the motor, used to collect the speed of the gearbox gear in real time and transmit the collected information to the VCU controller. The VCU control receives the speed of the gearbox gear, executes the torque calculation logic, and generates a torque instruction based on the calculated torque value required for shifting, and transmits it to the MCU. The MCU controls the motor to respond to the torque instruction and reaches the torque required for shifting, so that the gearbox is uncoupled, and then the shift mechanism is used for shifting.

[0021] The gearbox shifting control method provided by the application specifically includes S10~S30: S10: The MCU collects the speed of the gearbox gear in real time and sends it to the VCU controller.

[0022] It should be noted that the speed of the gearbox gear is the motor speed.

[0023] S20: The VCU controller calculates a theoretical torque value based on the moment of inertia of the gearbox gear and the change in rotational speed, and calculates the maximum hysteresis time for the MCU to collect the rotational speed to the response torque; based on the maximum hysteresis time and the theoretical torque value, the maximum inertial torque value is obtained, thereby generating a torque instruction and sending it to the MCU.

[0024] S30: The MCU controls the motor to respond to the torque instruction until the gearbox is out of gear, thereby shifting through the shift mechanism.

[0025] Further, the VCU controller calculates the theoretical torque value based on the moment of inertia of the gearbox gear and the change in rotational speed, including steps 1-1~1-4: Step 1-1: Based on the rotational speed of the gearbox gear collected and transmitted by the MCU in real time, the change in rotational speed of the gearbox gear is calculated.

[0026] Step 1-2: Calculate the angular velocity change of the gearbox gear based on the change in rotational speed of the gearbox gear.

[0027] Step 1-3: Calculate the angular acceleration of the gearbox gear based on the angular velocity change of the gearbox gear.

[0028] Step 1-4: Based on the product of the angular acceleration of the gearbox gear and the moment of inertia, the theoretical torque value is obtained.

[0029] Specifically, the calculation formula of the theoretical torque value is: , Wherein, represents the theoretical torque value; represents the moment of inertia; represents the angular acceleration; represents the angular velocity change; represents the change in rotational speed of the gearbox gear; represents the time interval.

[0030] Further, the maximum hysteresis time for the MCU to collect the rotational speed to the response torque is calculated, including: Based on the sum of the rotational speed collection time of the MCU, the time for the MCU to transmit the rotational speed to the VCU controller, the calculation time of the maximum inertial torque value, and the time for the VCU controller to transmit the torque instruction to the MCU, the maximum hysteresis time is obtained.

[0031] Specifically, since the deviation between the actual required torque value and the calculated theoretical torque value is caused by the information transmission time between the MCU and the VCU controller, the application modifies the calculated theoretical torque value by considering the information interaction time between the MCU and the VCU controller, so that the modified torque value is close to the actual required torque value. For example, the speed acquisition time of the MCU is generally 2ms, which is a short process time and can be ignored in actual calculation. The speed transmission time, the maximum inertia torque calculation time and the maximum inertia torque transmission time are generally about 10ms, and during this period of time, if the speed of the gearbox gear changes, the torque value required for the gear to disengage will change. If this error is not considered and the motor torque is directly adjusted to the theoretical torque value, the inertia torque caused by the transmission change of the gearbox gear will cause the gearbox to disengage.

[0032] Further, the maximum inertia torque value is obtained based on the maximum lag time and the theoretical torque value, including steps 2-1 to 2-4: Step 2-1: based on the maximum lag time and the speed change, the maximum estimated speed change value of the gearbox gear is calculated.

[0033] Step 2-2: based on the maximum estimated speed change value of the gearbox gear, the maximum angular speed change of the gearbox gear is calculated.

[0034] Step 2-3: based on the maximum angular speed change of the gearbox gear, the maximum angular acceleration of the gearbox gear is calculated.

[0035] Step 2-4: based on the product of the maximum angular acceleration of the gearbox gear and the moment of inertia, the maximum inertia torque value is obtained.

[0036] Specifically, the calculation formula of the maximum estimated speed change value of the gearbox gear is: , wherein, represents the maximum estimated speed change value of the gearbox gear; represents the speed change of the gearbox gear; represents the speed acquisition time of the MCU; represents the time for the MCU to transmit the speed to the VCU controller; represents the calculation time of the maximum inertia torque value; represents the time for the VCU controller to transmit the torque instruction to the MCU.

[0037] The calculation formula of the maximum inertia torque value is: , wherein, represents a maximum inertia torque value; represents a theoretical torque value.

[0038] Further, since the maximum change amount of the speed of the gearbox gear exists within the information transmission lag time, that is, the change amount of the speed of the gearbox gear will exist between ~ and the torque required for the gearshift will exist between the theoretical torque value and the maximum inertia torque value, therefore, after the maximum inertia torque value is calculated, the motor torque only needs to be controlled to change between the theoretical torque value and the maximum inertia torque value, that is, a value can be found to meet the torque value required for the gearshift of the gearbox, so as to realize the gearshift of the gearbox.

[0039] In some embodiments of the present application, the motor torque is controlled in a gradual manner, so that the torque required for the gearshift of the gearbox can be found more quickly and efficiently. Specifically, the torque instruction includes: controlling the motor torque to increase from the theoretical torque value according to a preset gradient until the motor torque is equal to the maximum inertia torque value; controlling the motor torque to decrease from the maximum inertia torque value according to the preset gradient until the motor torque is equal to the theoretical torque value.

[0040] Specifically, the preset gradient is equal to the maximum matrix tolerance deviation of the gearshift of the gearbox.

[0041] Optionally, in some embodiments, the motor torque can also be controlled in a waveform control manner, for example, a triangular wave with a preset gradient can be generated, so as to control the motor torque to gradually increase and then decrease between the theoretical torque value and the maximum inertia torque value.

[0042] It should be noted that since the gearshift difficulty problem may occur when the gearbox is shifted, in actual application scenarios, the gearbox shift control method provided by the present application can also be used to control the motor torque after the gearshift difficulty is tried, and the gearbox shift control method provided by the present application can be applied to various motor and gearbox configuration systems.

[0043] Based on the gearbox shift control method provided in the above embodiments, the present application further provides a gearbox shift control system, which includes an MCU and a VCU control. In actual application scenarios, the MCU is in communication connection with the gearbox, the VCU controller and the motor.

[0044] The MCU is used to collect the speed of the gearbox gear in real time and send it to the VCU controller, control the motor to respond to the torque instruction, and until the gearbox is shifted, so as to shift through the shift mechanism.

[0045] The VCU controller is configured to calculate a theoretical torque value based on the moment of inertia of the gearbox gear and the speed change amount, and calculate a maximum hysteresis time of the MCU in collecting the speed to the response torque; based on the maximum hysteresis time and the theoretical torque value, a maximum inertia torque value is obtained, so as to generate a torque instruction and send it to the MCU.

[0046] Further, the embodiment of the present application also provides an electric vehicle, which comprises the gearbox shift control system provided by the above embodiment, and is used for controlling the motor torque during the shift of the vehicle, so as to prevent the gear from being stuck.

[0047] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system or a computer program product. Therefore, the present application can adopt a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware aspects. Moreover, the present application can adopt a computer program product implemented on one or more computer usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer usable program codes.

[0048] The present application is described with reference to flowcharts and / or block diagrams of the methods, devices (systems) and computer program products according to the embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of the flows and / or blocks in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing devices to produce a machine, so that the instructions executed by the computer or other programmable data processing devices produce a device implemented in the flowcharts and / or block diagrams. Figure 1 The device that implements the function specified in one or more flows and / or blocks. Figure 1 The device that implements the function specified in one or more flows and / or blocks.

[0049] These computer program instructions can also be stored in a computer readable storage medium capable of guiding the computer or other programmable data processing devices to work in a specific way, so that the instructions stored in the computer readable storage medium produce a manufactured product including instruction devices, which implement the flowcharts and / or block diagrams. Figure 1 The device that implements the function specified in one or more flows and / or blocks. Figure 1 The device that implements the function specified in one or more flows and / or blocks.

[0050] These computer program instructions can also be loaded into the computer or other programmable data processing devices, so that a series of operation steps are performed on the computer or other programmable devices to produce a computer implemented process, so that the instructions executed on the computer or other programmable devices provide a process for implementing the flowcharts and / or block diagrams. Figure 1 The device that implements the function specified in one or more flows and / or blocks.Figure 1 the steps of the functions specified in the one or more blocks.

[0051] Obviously, the above-described embodiments are only examples for the purpose of clarity and are not intended to limit the implementation. Based on the above description, other different forms of changes or variations can also be made by those of ordinary skill in the art. Here, it is not necessary and impossible to exhaust all the implementations. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A gearbox shift control method, characterized in that, Applied to a transmission shift control system, the transmission shift control system includes an MCU and a VCU controller, including: The MCU collects the rotational speed of the gearbox gears in real time and sends it to the VCU controller; The VCU controller calculates the theoretical torque value based on the rotational inertia of the gearbox gears and the change in rotational speed, and calculates the maximum lag time from the MCU acquiring the rotational speed to the response torque; based on the maximum lag time and the theoretical torque value, it obtains the maximum inertial torque value, thereby generating a torque command and sending it to the MCU; The MCU controls the motor to respond to torque commands until the gearbox disengages, thereby shifting gears through the shifting mechanism.

2. The gearbox shift control method according to claim 1, characterized in that, The VCU controller calculates the theoretical torque value based on the rotational inertia of the gearbox gears and the change in rotational speed, including: The change in gear speed is calculated based on the real-time acquisition and transmission of gear speed by the MCU. Calculate the change in angular velocity of the gearbox gears based on the change in rotational speed of the gearbox gears; Calculate the angular acceleration of the gearbox gears based on the change in angular velocity of the gearbox gears; The theoretical torque value is obtained by multiplying the angular acceleration and rotational inertia of the gearbox gears.

3. The gearbox shift control method according to claim 2, characterized in that, The formula for calculating the theoretical torque value is: ， in, This represents the theoretical torque value; Indicates the moment of inertia; Indicates angular acceleration; Indicates the change in angular velocity; This indicates the change in rotational speed of the gearbox gears; Indicates a time interval.

4. The gearbox shift control method according to claim 1, characterized in that, Calculate the maximum lag time from the MCU acquiring the rotational speed to the response torque, including: The maximum lag time is obtained by summing the rotational speed acquisition time of the MCU, the time for the MCU to transmit the rotational speed to the VCU controller, the calculation time of the maximum inertial torque value, and the time for the VCU controller to transmit the torque command to the MCU.

5. The gearbox shift control method according to claim 4, characterized in that, The maximum inertial torque value is obtained based on the maximum lag time and the theoretical torque value, including: Based on the maximum lag time and the change in speed, the maximum estimated change in speed of the gearbox gear is calculated. Calculate the maximum angular velocity change of the gearbox gears based on the maximum estimated speed change of the gearbox gears. Calculate the maximum angular acceleration of the gearbox gears based on the maximum angular velocity change of the gearbox gears; The maximum inertial torque value is obtained by multiplying the maximum angular acceleration of the gearbox gear by its moment of inertia.

6. The gearbox shift control method according to claim 5, characterized in that, The formula for calculating the maximum estimated speed change of the gearbox gears is as follows: ， in, This indicates the maximum estimated speed change of the gearbox gears; This indicates the change in rotational speed of the gearbox gears; This indicates the rotational speed acquisition time of the MCU; This indicates the time it takes for the MCU to transmit the rotational speed to the VCU controller; Indicates the calculation time for the maximum inertial torque value; This indicates the time it takes for the VCU controller to transmit torque commands to the MCU; The formula for calculating the maximum inertial torque is: ， in, This represents the maximum inertial torque value; This represents the theoretical torque value.

7. The gearbox shift control method according to claim 1, characterized in that, Torque commands include: The motor torque is controlled to increase from the theoretical torque value according to a preset gradient until the motor torque equals the maximum inertial torque value; The motor torque is controlled to decrease from the maximum inertial torque value according to a preset gradient until the motor torque equals the theoretical torque value.

8. The gearbox shift control method according to claim 7, characterized in that, The preset gradient is equal to the maximum matrix tolerance deviation of the gearbox disengagement.

9. A gearbox shift control system, characterized in that, The method for implementing the gearbox shift control method according to any one of claims 1 to 8 includes: The MCU communicates with the gearbox, VCU controller, and motor to collect the speed of the gearbox gears in real time and send it to the VCU controller to control the motor to respond to torque commands until the gearbox disengages, thereby shifting gears through the shifting mechanism. The VCU controller is used to calculate the theoretical torque value based on the rotational inertia of the gearbox gears and the change in rotational speed, and to calculate the maximum lag time from the rotational speed acquired by the MCU to the response torque; based on the maximum lag time and the theoretical torque value, the maximum inertial torque value is obtained, thereby generating a torque command and sending it to the MCU.

10. An electric vehicle, characterized in that, The electric vehicle includes the gearbox shift control system as described in claim 9.

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