阅读说明：本技术 一种混动车辆的驱动控制方法、系统 (Drive control method and system for hybrid vehicle ) 是由 孙国安 徐雷 李建辉 王昫 王长青 章宏文 刘新强 刘烨 于 2020-04-30 设计创作，主要内容包括：本发明涉及车辆驱动控制领域,提供一种混动车辆的驱动控制方法、系统,混动车辆包括配置有发动机的前桥动力系统和配置有驱动电机以及绝对位置传感器的后桥动力系统,包括：实时获取来自绝对位置传感器的其所测得的示出拨叉的当前位置的当前脉宽调制信号；以及根据实时获取到的当前脉宽调制信号,确定拨叉的当前位置,并根据当前位置,控制拨叉移动至一位置以使得驱动电机的输出挡位为空挡,其中驱动电机处于空挡时,混动车辆在前桥动力系统的发动机的驱动下跛行。本发明的混动车辆的驱动控制方法在后桥动力系统出现故障时控制车辆继续行驶,增加了车辆的可用性。(The invention relates to the field of vehicle drive control, and provides a drive control method and a system for a hybrid vehicle, wherein the hybrid vehicle comprises a front axle power system provided with an engine and a rear axle power system provided with a drive motor and an absolute position sensor, and the drive control method comprises the following steps: acquiring a current pulse width modulation signal showing the current position of the shift fork measured by the absolute position sensor in real time; and determining the current position of the shifting fork according to the current pulse width modulation signal acquired in real time, and controlling the shifting fork to move to a position according to the current position so as to enable the output gear of the driving motor to be a neutral gear, wherein when the driving motor is in the neutral gear, the hybrid vehicle limps under the driving of an engine of a front axle power system. The driving control method of the hybrid vehicle controls the vehicle to continuously run when the rear axle power system fails, so that the usability of the vehicle is increased.)

1. A drive control method of a hybrid vehicle, characterized in that the hybrid vehicle includes a front axle power system provided with an engine and a rear axle power system provided with a drive motor and an absolute position sensor, the drive control method of the hybrid vehicle comprising:

acquiring a current pulse width modulation signal from the absolute position sensor in real time, wherein the current pulse width modulation signal shows the current position of the shifting fork measured by the absolute position sensor; and

and determining the current position of the shifting fork according to the current pulse width modulation signal acquired in real time, and controlling the shifting fork to move to a position according to the current position so as to enable the output gear of the driving motor to be a neutral gear, wherein when the driving motor is in the neutral gear, the hybrid vehicle limps under the driving of an engine of the front axle power system.

2. The drive control method of a hybrid vehicle according to claim 1,

the absolute position sensor is provided with a shifting fork sensor and magnetic steel which is arranged on the shifting fork and can generate a magnetic field;

the acquiring in real time a current pulse width modulation signal from the absolute position sensor showing a current position of a shift fork comprises:

acquiring a current magnetic field signal generated by the shifting fork sensor sensing the magnetic field; and

and acquiring a current magnetic field signal converted into a current pulse width modulation signal showing the current position of the shifting fork by the shifting fork sensor.

3. The drive control method of a hybrid vehicle according to claim 1, wherein the determining the current position of the shift fork according to the current pulse width modulation signal acquired in real time includes:

acquiring the duty ratio of the current pulse width modulation signal; and

and determining the current position of the shifting fork according to the duty ratio of the current pulse width modulation signal and the preset corresponding relation between the duty ratio of each pulse width modulation signal and each absolute position.

4. The drive control method of a hybrid vehicle according to claim 3, wherein the controlling of the shift fork to move to a position such that the output gear of the drive motor is neutral according to the current position includes:

in the process of controlling the shifting fork to move towards a position according to the current position, acquiring a difference value between the duty ratio of the current pulse width modulation signal and a preset duty ratio threshold value in real time, wherein the duty ratio threshold value is configured to be the duty ratio of the pulse width modulation signal corresponding to the neutral gear; and

and when the difference value is smaller than a preset threshold value, judging that the shifting fork moves to a position so that the output gear of the driving motor is a neutral gear.

5. The drive control method of a hybrid vehicle according to claim 1,

the rear axle power system is provided with a relative position sensor which determines the current absolute position of the shifting fork through the initial position and the relative displacement of the shifting fork;

before the obtaining the current pulse width modulation signal in real time, the method for controlling the driving of the hybrid vehicle further comprises:

and judging whether the relative position sensor is in a normal working state, wherein the normal working state is configured to be capable of identifying the initial position of the shifting fork, and if not, controlling the hybrid vehicle to execute the step of acquiring the current pulse width modulation signal showing the current position of the shifting fork from the absolute position sensor in real time.

6. The drive control method of a hybrid vehicle according to claim 5, characterized in that before the acquiring of the current pulse width modulation signal in real time and after the determining whether the relative position sensor is in a normal operating state, the drive control method of a hybrid vehicle further comprises:

and continuously judging whether the absolute position sensor can work normally, if so, controlling the hybrid vehicle to execute the step of acquiring the current pulse width modulation signal which is from the absolute position sensor and shows the current position of the shifting fork in real time.

7. A drive control system of a hybrid vehicle, characterized by comprising a front axle power system provided with an engine and a rear axle power system provided with a drive motor and an absolute position sensor, comprising:

the absolute position sensor is used for sending a current pulse width modulation signal showing the current position of the shifting fork measured by the absolute position sensor in real time; and

and the actuator control unit is used for determining the current position of the shifting fork according to the acquired current pulse width modulation signal sent by the absolute position sensor in real time, and controlling the shifting fork to move to a position so as to enable the output gear of the driving motor to be a neutral gear according to the current position, wherein when the driving motor is in the neutral gear, the hybrid vehicle limps under the driving of an engine of the front axle power system.

8. The drive control system of a hybrid vehicle according to claim 7,

the absolute position sensor comprises a shifting fork sensor and magnetic steel which is arranged on the shifting fork and can generate a magnetic field, and the shifting fork sensor is used for sensing a current magnetic field signal generated by the magnetic field and converting the current magnetic field signal into a current pulse width modulation signal showing the current position of the shifting fork.

9. The drive control system of a hybrid vehicle according to claim 8, characterized in that the actuator control unit includes:

a duty ratio obtaining module, configured to obtain a duty ratio of the current pulse width modulation signal; and

and the position determining module is used for determining the current position of the shifting fork according to the duty ratio of the current pulse width modulation signal and the preset corresponding relation between the duty ratio of each pulse width modulation signal and each absolute position.

10. A computer-readable storage medium having stored thereon computer program instructions for causing a machine to execute the drive control method of a hybrid vehicle according to any one of claims 1 to 6.

Technical Field

The invention relates to the technical field of vehicle drive control, in particular to a drive control method and a drive control system for a hybrid vehicle.

Background

In a power assembly of the hybrid vehicle, a front axle adopts a traditional power system driven by an engine, a rear axle adopts a power system driven by a driving motor, and the power systems of the front axle and the rear axle are completely independent. The power system of the rear axle comprises a driving motor, a gear shifting executing mechanism, a controller and the like, wherein in the gear shifting process, the controller is adopted to control the gear shifting executing mechanism to realize the gear shifting driven by the driving motor, and the gear shifting can be realized without arranging a clutch because the rotating speed of the driving motor can be accurately controlled. The gear shifting executing mechanism comprises a gear shifting motor, a gear shifting lead screw assembly, a shifting fork, a synchronizer, a relative position sensor and an absolute position sensor, wherein the gear shifting motor is connected with one end of the gear shifting lead screw assembly, the shifting fork is arranged on the gear shifting lead screw assembly and can axially move along with the gear shifting lead screw assembly, and the synchronizer arranged between the gear gears is shifted to move so as to realize gear shifting.

Under the vehicle normal driving state, when the driving system of rear axle shifts gears, shift motor drives the shift fork through the lead screw subassembly that shifts gears and removes, and relative position sensor (for example, hall sensor) that sets up on shift motor monitors the position of keeping off a position, and shift fork position sensor then only is used for doing the check-up of the initial position of back of electricity and is used as the diagnosis cross check-up of neutral gear, and wherein hall sensor need discern the shift fork initial position and then realize the control of driving motor's position. When the power system of rear axle breaks down and hall sensor can't discern shift fork initial position, the controller of hybrid vehicle can't break off the driving connection of driving motor and the reduction gear that connects among the power system of rear axle, this moment, can cause following consequence: the rotation of the rear wheel can cause the driving motor to be dragged reversely, and the risk that the driving motor is damaged due to the fact that the rotating speed of the driving motor is over-speed exists; the absolute position of the shifting fork cannot be judged, whether the synchronizer is engaged with a gear position cannot be determined, if the combination teeth of the synchronizer are not effectively combined at the moment, the combination teeth or the synchronous conical surface of the synchronizer are damaged due to long-time friction due to rotation of the rear wheel, and therefore the gear shifting function of the hybrid vehicle is damaged. In order to ensure the safety of the vehicle, in the above case, the vehicle is generally stopped, which results in reduced usability of the vehicle.

Disclosure of Invention

In view of the above, the present invention is directed to a driving control method for a hybrid vehicle, so as to control the vehicle to continue to run when a rear axle power system fails, thereby increasing the usability of the vehicle.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

a drive control method of a hybrid vehicle including a front axle power system configured with an engine and a rear axle power system configured with a drive motor and an absolute position sensor, comprising: acquiring a current pulse width modulation signal from the absolute position sensor in real time, wherein the current pulse width modulation signal shows the current position of the shifting fork measured by the absolute position sensor; and determining the current absolute position of the shifting fork according to the current pulse width modulation signal acquired in real time, and controlling the shifting fork to move to a position according to the current absolute position so that the output gear of the driving motor is a neutral gear, wherein when the driving motor is in the neutral gear, the hybrid vehicle limps under the driving of an engine of the front axle power system.

Preferably, the absolute position sensor is provided with a shifting fork sensor and magnetic steel which is arranged on the shifting fork and can generate a magnetic field; the acquiring in real time a current pulse width modulation signal from the absolute position sensor showing a current position of a shift fork comprises: acquiring a current magnetic field signal generated by the shifting fork sensor sensing the magnetic field; and acquiring a current pulse width modulation signal which is converted by the shifting fork sensor into a current magnetic field signal showing the current position of the shifting fork.

Preferably, the determining the current position of the shifting fork according to the current pulse width modulation signal acquired in real time includes: acquiring the duty ratio of the current pulse width modulation signal; and determining the current position of the shifting fork according to the duty ratio of the current pulse width modulation signal and the preset corresponding relation between the duty ratio of each pulse width modulation signal and each absolute position.

Preferably, the controlling the shift fork to move to a position such that the output gear of the driving motor is neutral according to the current position includes: in the process of controlling the shifting fork to move towards a position according to the current position, acquiring a difference value between the duty ratio of the current pulse width modulation signal and a preset duty ratio threshold value in real time, wherein the duty ratio threshold value is configured to be the duty ratio of the pulse width modulation signal corresponding to the neutral gear; and when the difference value is smaller than a preset threshold value, judging that the shifting fork moves to a position so that the output gear of the driving motor is a neutral gear.

Preferably, the rear axle power system is provided with a relative position sensor for determining the current absolute position of the shift fork through the initial position and the relative displacement of the shift fork; before the obtaining the current pulse width modulation signal in real time, the method for controlling the driving of the hybrid vehicle further comprises: and judging whether the relative position sensor is in a normal working state, wherein the normal working state is configured to be capable of identifying the initial position of the shifting fork, and if not, controlling the hybrid vehicle to execute the step of acquiring the current pulse width modulation signal showing the current position of the shifting fork from the absolute position sensor in real time.

Preferably, before the obtaining of the current pwm signal in real time and after the determining whether the relative position sensor is in a normal operating state, the method for controlling driving of a hybrid vehicle further includes: and continuously judging whether the absolute position sensor can work normally, if so, controlling the hybrid vehicle to execute the step of acquiring a current pulse width modulation signal which is from the absolute position sensor and shows the current absolute position of the shifting fork in real time.

Compared with the prior art, the driving control method of the hybrid vehicle has the following advantages:

when a rear axle power system of the hybrid vehicle breaks down and cannot acquire the current absolute position of a shifting fork through a preset relative position sensor, acquiring the current pulse width modulation signal of the current absolute position of the shifting fork of the absolute position sensor in real time, wherein the absolute position sensor is only used for verifying the initial gear after power-on and used for diagnosing and cross-verifying neutral gear, the present embodiment utilizes the characteristic that the absolute position sensor can detect the current pulse width modulation signal showing the current absolute position of the shifting fork to acquire the current absolute position of the shifting fork, and controls the shifting fork to move to a position according to the current absolute position to enable the output gear of the driving motor to be neutral gear, so that the driving force source of the hybrid vehicle is only a front axle power system, the rear axle power system is in the neutral position, and the driving motor cannot be dragged reversely under the condition that a rear wheel rotates, thereby protecting the rear axle power system and increasing the usability of the vehicle by utilizing a limp-home mode.

Another object of the present invention is to provide a drive control system for a hybrid vehicle to control the vehicle to continue traveling when a rear axle power system fails, increasing the usability of the vehicle.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

a drive control system of a hybrid vehicle including a front axle power system configured with an engine and a rear axle power system configured with a drive motor and an absolute position sensor, comprising: the absolute position sensor is used for acquiring the measured current position of the shifting fork in real time; and the actuator control unit is used for controlling the shifting fork to move towards the direction which can enable the output gear of the driving motor to be the position corresponding to the neutral gear according to the current position acquired in real time until the shifting fork reaches the position corresponding to the neutral gear, so that the hybrid vehicle can limp under the driving of the engine.

Preferably, the absolute position sensor includes: the modulation signal acquisition module is used for acquiring a current modulation signal generated by the absolute position sensor sensing the current position of the shifting fork; and the absolute position determining module is used for determining the current position corresponding to the current modulation signal according to the preset corresponding relation between each modulation signal and each position.

Preferably, the actuator control unit includes: the driving control module is used for controlling the shifting fork to move towards the direction of the position corresponding to the neutral gear; the duty ratio acquisition module is used for acquiring the difference value between the duty ratios of the modulation signals of the absolute position sensors corresponding to the position of the shifting fork corresponding to the neutral gear and the current position in real time; and the position judgment module is used for judging that the shifting fork reaches the position corresponding to the neutral gear when the difference value is smaller than a preset threshold value.

In addition, the present embodiment also provides a computer-readable storage medium having stored thereon computer program instructions for causing a machine to execute the above-described drive control method of a hybrid vehicle.

The drive control system of the hybrid vehicle and the drive control method of the hybrid vehicle with the computer readable storage medium have the same advantages over the prior art, and are not described herein again.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention.

In the drawings:

FIG. 1 is a schematic structural diagram of a rear axle powertrain according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of an absolute position sensor according to an embodiment of the present invention;

fig. 3 is a flowchart of a drive control method of a hybrid vehicle according to an embodiment of the present invention;

FIG. 4 is a graph of duty cycle and shift fork displacement of a PWM signal according to an embodiment of the present invention;

fig. 5 is a flowchart of a drive control method of a hybrid vehicle before a current absolute position of the shift fork is acquired in real time according to an embodiment of the present invention;

fig. 6 is a flowchart of a drive control method of a preferred hybrid vehicle according to an embodiment of the present invention; and

fig. 7 is a block diagram of a drive control system of a hybrid vehicle according to an embodiment of the present invention.

Description of reference numerals:

701. absolute position sensor 102 and actuator control unit

201. Magnetic steel 202 and shifting fork sensor

703. Position determination module 704 and duty ratio acquisition module

705. Difference value acquisition module 706 and neutral gear judgment module

702. Relative position sensor 104 and shift motor

105. Shifting fork 106 and synchronizer

Detailed Description

In addition, the embodiments of the present invention and the features of the embodiments may be combined with each other without conflict.

The hybrid vehicle comprises a front axle power system and a rear axle power system, wherein the rear axle power system can realize gear shifting without a clutch because the rotating speed of a driving motor can be accurately controlled. In the process of shifting the rear axle power system, as shown in fig. 1, a Hybrid control unit 101 (HCU) is responsible for regulating and controlling the entire Hybrid system, sending a target gear and shifting a permission; the actuator control unit 102 (ACU) is responsible for controlling the shifting motor to drive the shifting fork and the synchronizer to shift the speed reducer; the driving Motor control unit 103 (MCU) is responsible for controlling the driving Motor to cooperate with the speed regulation before shifting and provide power output after shifting is completed.

The HCU and the ACU realize gear shifting by controlling a gear shifting executing mechanism, and as can be seen from the above description, the gear shifting executing mechanism is composed of a gear shifting motor 104, a gear shifting screw assembly, a shifting fork 105, a synchronizer 106, a relative position sensor, an absolute position sensor, and the like. Wherein, relative position sensor for example hall sensor, it is the inside a plurality of subcomponents of circumference equipartition of brushless DC gear shifting motor, and its theory of operation of confirming present absolute position does: the ACU can calculate the rotating angle of a rotor of a driving motor in a sampling period by capturing the output level signal change of a Hall sensor (relative position sensor), and obtain the moving distance of a shifting fork according to the speed ratio relation of a shifting actuating mechanism, the ACU can determine the current absolute position of the shifting fork according to the moving distance, in other words, the relative position sensor controls the shifting fork to execute preset movement to search the initial position of the shifting fork, the value of the current relative position sensor is recorded as the initial value of the relative position sensor to correspond to the searched initial position, and the values of the initial position sensor and the initial relative position sensor are used for calculating the real-time absolute position of the shifting fork. As shown in fig. 2, the absolute position sensor is composed of a magnetic steel 201 and a shifting fork sensor 202, the magnetic steel 201 is installed at the top of the shifting fork 105, the shifting fork sensor 202 is installed on the transmission shell and just faces to the magnetic steel 201 at the top of the shifting fork, and the shifting fork sensor 202 and the magnetic steel 201 are arranged at intervals.

In the prior art, if the relative position sensor successfully searches for the initial position of the shifting fork, the absolute position of the shifting fork in real time is calculated according to the reading of the current relative position sensor, the initial position and the reading of the initial relative position sensor in the calculation mode; if the finding of the initial position of the shifting fork fails and the absolute position sensor works normally, a strategy of disconnecting the power connection from the absolute position sensor is executed, namely the improved strategy of the invention.

If hall sensor damages to lead to its current absolute position that can't acquire shift fork 105, will cause the unable disconnection of driving motor's drive output, and this embodiment will adopt the absolute position sensor to acquire the current absolute position of shift fork 105. Next, the technical solution of the present invention will be described in detail with reference to a plurality of drawings.

Fig. 3 is a flowchart of a driving control method of a hybrid vehicle according to the present invention, as shown in fig. 3 and described above, the hybrid vehicle includes a front axle power system configured with an engine and a rear axle power system configured with a driving motor and an absolute position sensor, which are not described herein again, and the driving control method includes:

s301, acquiring a current pulse width modulation signal which is from the absolute position sensor and shows the current position of the shifting fork in real time.

S302, determining the current absolute position of the shifting fork according to the current pulse width modulation signal acquired in real time, and controlling the shifting fork to move to a position according to the current absolute position so that the output gear of the driving motor is a neutral gear, wherein when the driving motor is in the neutral gear, the hybrid vehicle limps under the driving of an engine of the front axle power system.

The present invention is characterized in that the present absolute position of the shift fork is obtained by using an absolute position sensor, in the prior art, the absolute position sensor is only used for verifying the initial gear after power-on and for diagnostic cross-checking the neutral gear, and the relative position sensor is used for checking the present absolute position of the shift fork, because the absolute position sensor has a large deviation in measuring the absolute position and has poor interference resistance, for example, the present pulse width modulation signal showing the present absolute position obtained from the absolute position sensor of the present invention cannot reflect the actual present absolute position, wherein the more the measured pulse width deviates from 50%, the larger the error is, the more the system is used for neutral position detection and neutral cross-checking, the specific error is shown in fig. 4, and the present invention only uses the above characteristics, and the position obtained by using the absolute position sensor is only used for subsequently executing the related steps, so that the rear axle power system of the vehicle is driven and driven The output of the motor is neutral. According to the invention, the absolute position sensor is used for acquiring the current pulse width modulation signal which is absolutely related to the current position of the shifting fork, as mentioned above, the current position is not true and is only used for reference of subsequently moving the shifting fork to the position corresponding to the neutral gear, so that the phenomenon that the current absolute position of the shifting fork cannot be acquired through the Hall sensor after a rear axle power system is damaged, and further the disconnection of the power connection between the driving motor and the rear wheel cannot be realized, and the situation that the driving motor is reversely dragged and damaged under the driving of the rear wheel is caused.

Further preferably, as shown in fig. 2, the absolute position sensor is configured with a fork sensor and a magnetic steel capable of generating a magnetic field and disposed on the fork, and the S301 includes:

acquiring a current magnetic field signal generated by the shifting fork sensor sensing the magnetic field; and acquiring a current pulse width modulation signal which is converted by the shifting fork sensor into a current magnetic field signal showing the current absolute position of the shifting fork.

Wherein, can produce the magnetic field on the magnet steel, absolute position sensor is used for the response the magnetic field of magnet steel, because magnet steel and shift fork fixed connection work as the shift fork with during the magnet steel synchronous motion, absolute position sensor response the magnetic field of magnet steel can change, ACU can with current magnetic field signal converts the current pulse width modulation signal that shows the current absolute position of shift fork into, when the magnetic field changes, current pulse width modulation signal also can change.

Further preferably, the determining the current position of the shifting fork according to the current pulse width modulation signal (PWM signal) acquired in real time includes:

acquiring the duty ratio of the current pulse width modulation signal; and determining the current position of the shifting fork according to the duty ratio of the current pulse width modulation signal and the preset corresponding relation between the duty ratio of each pulse width modulation signal and each position.

The absolute position sensor is composed of magnetic steel and a shifting fork sensor, a shifting motor drives a shifting fork to move through a shifting screw rod assembly, the change of the position of the magnetic steel on the shifting fork causes the change of a magnetic field received by the shifting fork sensor, the shifting fork sensor converts a magnetic field signal obtained by the magnetic field into a PWM signal according to the Hall principle and outputs the PWM signal to the ACU, and the ACU determines the current position of the shifting fork corresponding to the duty ratio of the current PWM signal according to the characteristic relation between the duty ratio of a longitudinal coordinate PWM signal and the displacement of a transverse coordinate shifting fork in figure 4, wherein the shifting fork displacement unit is mm.

In addition, as shown in fig. 4, line segments with different slopes represent the corresponding relationship between the shift fork displacement (which can be used to represent the absolute position) with different air gap values and the duty ratio of the PWM signal, wherein a shift fork displacement of 0 represents that the shift fork is at the initial position, and the initial position is the position corresponding to the output gear of the driving motor being the neutral gear. The value of the air gap is greatly influenced by the installation and vibration of the absolute position sensor, namely the measured value has poor anti-jamming capability, but it can be seen that the corresponding relation straight line of the plug displacement corresponding to different air gaps and the duty ratio of PWM is intersected at one point (0, 50%), which shows that the measurement accuracy and the anti-jamming capability of the sensor at the neutral position with the displacement of 0 are good, so that whether the shifting fork reaches the neutral position can be monitored by utilizing the characteristic, and further, after the rear axle power system is damaged, the neutral position closed-loop control under the condition that the absolute position of the shifting fork cannot be known through the relative position sensor, namely the Hall sensor, cannot be realized under the condition that the power connection between the driving motor and the rear wheel is disconnected. The corresponding relation between each modulation signal and each position of the absolute position sensor under each air gap is shown in the following table 1:

TABLE 1

Wherein shift fork displacement "-10" indicates that the relative displacement of the shift fork displacement and the position corresponding to the neutral position is "-10". Table 1 shows that the shift fork displacement "0" indicates a position corresponding to the neutral position, and it can be seen that, regardless of the value of the air gap, when the shift fork displacement is 0 (position corresponding to the neutral position), the duty ratio of the PWM is 50%.

Further preferably, the S302 includes: in the process of controlling the shifting fork to move towards a position according to the current absolute position, acquiring a difference value between the duty ratio of the current pulse width modulation signal and a preset duty ratio threshold value in real time, wherein the duty ratio threshold value is configured to be the duty ratio of the pulse width modulation signal corresponding to the neutral gear; and when the difference value is smaller than a preset threshold value, judging that the shifting fork moves to a position so that the output gear of the driving motor is a neutral gear.

When the duty ratio of the pulse width modulation signal corresponding to the neutral gear is known to be 50%, determining that the shifting fork reaches the position corresponding to the neutral gear under the condition that the following formula is satisfied:

|PWM–50％|≤X；

PWM is the duty ratio of the current absolute position sensor feedback actually measured, and X is a preset threshold value within an error allowable range.

For example, when the value range of X is 0.1, if the PWM is 50.1, it is determined that the shift fork has reached the position corresponding to the neutral position.

When the shifting fork is judged to reach the position corresponding to the neutral gear, the ACU reports the completion state that the current shifting fork position moves to the position corresponding to the neutral gear through the CAN bus, and the HCU controls a power system of the whole vehicle to limp according to the state fed back by the ACU.

Further preferably, the rear axle power system is provided with a relative position sensor for determining the current position of the shift fork through the initial position and the relative displacement of the shift fork, fig. 5 is a driving control method of the hybrid vehicle before the current pulse width modulation signal of the shift fork is obtained in real time, and as shown in fig. 5, the driving control method of the hybrid vehicle includes:

s501, judging whether the relative position sensor is in a normal working state or not, wherein the normal working state is configured to be capable of identifying the initial position of the shifting fork;

s502, if the relative position sensor is in an abnormal working state, namely the initial position of the shifting fork cannot be identified, controlling the hybrid vehicle to execute the step of acquiring the current pulse width modulation signal showing the current position of the shifting fork from the absolute position sensor in real time.

As mentioned above, the relative position sensor is a hall sensor, which is dedicated to detect the current absolute position of the shift fork, wherein the current absolute position is configured to reflect the output gear of the driving motor of the rear axle power system, and the current absolute position at which the shift fork cannot be obtained is specifically represented as: when the initial position of the shifting fork is lost or is judged to be unreliable by software logic, the output gear of the driving motor of the rear axle power system needs to be obtained by the ACU through self-learning and identifying the initial position of the shifting fork, the ACU receives HCU self-learning permission, the ACU drives the shifting motor to rotate for self-learning, the Hall sensor for obtaining the reliable source of the position of the shifting fork can only obtain relative displacement, under the condition that the initial position of the shifting fork is unknown, the shifting motor cannot move the shifting fork to a relatively reliable neutral position, and under the condition, self-learning fails.

Further preferably, before the acquiring a current pulse width modulation signal of the shift fork in real time and after the determining whether the relative position sensor is in a normal operating state, the method for controlling driving of a hybrid vehicle further includes: continuously judging whether the absolute position sensor can work normally or not; and when the absolute position sensor can work normally, controlling the vehicle to execute the step of acquiring a current pulse width modulation signal showing the current absolute position of the shift fork from the absolute position sensor in real time.

Wherein, the specific work flow is as follows: after the self-learning fails, the ACU informs the HCU of the current fault state of the ACU, and the HCU determines whether to allow the ACU to enter a limp neutral, that is, executes steps S301 and S302, according to the detection result of the operating state of the absolute position sensor.

In other words, when the operating state of the absolute position sensor is normal, the ACU is caused to perform the steps S301 and S302 for entering the limp neutral, and when the operating state of the absolute position sensor is a failure, the ACU reports the failure to enter the limp neutral, that is, the steps S301 and S302 and the cause of the failure to enter the limp neutral, to the HCU through the CAN bus.

Through the embodiment, whether the absolute position sensor works normally or not can be judged under the condition that the initial position of the shifting fork cannot be identified due to the failure of the rear axle power system and the failure of self-learning of the relative position sensor, the current position of the shifting fork is obtained by using the absolute position sensor when the absolute position sensor works normally, and the shifting fork is controlled to move towards the direction which can enable the output gear of the driving motor to be the position corresponding to the neutral gear according to the current position, for example, as shown in the table 1, the air gap value is 7, when the displacement of the shifting fork is-4, the shifting fork is controlled to move from the-4 position to the 0 position, the moving directions are sequentially-4, -3, -2, -1 and 0, when the 0 position is reached, the shifting fork for shifting is in the neutral position, and at the moment, the rear wheel is disconnected from the driving motor and the speed reducer, the hybrid vehicle limps under drive of an engine of the front axle powertrain.

Fig. 6 is a flowchart of a preferred drive control method of the hybrid vehicle. As shown in fig. 6, the drive control method of the hybrid vehicle includes:

s601, the ACU fails to learn by itself, and the initial position of the shifting fork cannot be obtained;

s602, whether an instruction for allowing the HCU to enter the limp neutral is received or not is judged, and the subsequent steps are not executed until the instruction is received;

s603, judging whether the absolute position sensor works normally or not if the judgment result of the S602 is yes;

s604, reporting a limp neutral failure state if the judgment result of the S603 is negative;

s605, judging whether the judgment result of the S603 is yes, and judging whether the condition that | PWM-50% | is less than or equal to X is met;

s606, when the absolute value of PWM-50% is not larger than X, the shifting fork is controlled to move towards the direction of the position corresponding to the neutral gear of the output gear of the driving motor;

and S607, when the situation that the absolute value of PWM-50 percent is less than or equal to X is met, reporting that the limp neutral gear is finished.

The driving control method of a preferred hybrid vehicle illustrated in fig. 6 has the same advantages as the driving control method of the hybrid vehicle illustrated in fig. 3 and 5 described above with respect to the prior art, and is not described herein again.

Fig. 7 is a block diagram of a drive control system of a hybrid vehicle including a front axle power system equipped with an engine and a rear axle power system equipped with a drive motor and an absolute position sensor, the drive control system of the hybrid vehicle including: the absolute position sensor 701 is used for sending a current pulse width modulation signal showing the current position of the shifting fork measured by the absolute position sensor in real time; and the actuator control unit 102 is configured to determine a current position of the shift fork according to the acquired current pulse width modulation signal sent by the absolute position sensor 701 in real time, and control the shift fork to move to a position according to the current position so that an output gear of the driving motor is a neutral gear, wherein when the driving motor is in the neutral gear, the hybrid vehicle limps under the driving of an engine of the front axle power system.

The rear axle power system is provided with a driving motor and a two-gear reduction box, and the two-gear reduction box is provided with an absolute position sensor, a gear shifting motor and a gear shifting actuating mechanism.

Preferably, the absolute position sensor 701 comprises a fork sensor 202 and a magnetic steel 201 which is arranged on the fork and can generate a magnetic field, wherein the fork sensor 202 is used for sensing a current magnetic field signal generated by the magnetic field and converting the current magnetic field signal into a current pulse width modulation signal showing the current position of the fork.

Preferably, the actuator control unit 102 includes: a duty ratio obtaining module 704, configured to obtain a duty ratio of the current pulse width modulation signal; and a position determining module 703, configured to determine the current position of the shifting fork according to the duty ratio of the current pwm signal and a preset corresponding relationship between the duty ratios of the pwm signals and the absolute positions.

Preferably, the actuator control unit 102 includes: a difference obtaining module 705, configured to obtain, in real time, a difference between a duty ratio of the current pwm signal and a preset duty ratio threshold in a process of controlling the shift fork to move to a position according to the current position, where the duty ratio threshold is configured to be a duty ratio of the pwm signal corresponding to the neutral gear; and a neutral determination module 706, configured to determine that the shift fork has moved to a position to enable the output gear of the driving motor to be a neutral gear when the difference is smaller than a preset threshold.

Preferably, the rear axle power system further includes a relative position sensor 702 determining a current position of the shift fork by an initial position and a relative displacement of the shift fork; the actuator control unit 102 is further configured to determine whether the relative position sensor 702 is in a normal operating state, where the normal operating state is configured to be able to identify an initial position of the shift fork, and if not, control the hybrid vehicle to perform the step of acquiring, in real time, a current pulse width modulation signal indicating a current position of the shift fork from the absolute position sensor 701.

Preferably, the actuator control unit 102 is further configured to continue to determine whether the absolute position sensor 701 can normally operate before the real-time obtaining of the current pwm signal and after the determining of whether the relative position sensor 702 is in the normal operating state, and if so, control the hybrid vehicle to perform the step of obtaining the current pwm signal showing the current position of the shift fork from the absolute position sensor 701 in real time.

The driving control system of the hybrid vehicle shown in fig. 7 has the same advantages as the driving control method of the hybrid vehicle described above with respect to the prior art, and is not described herein again.

In addition, an embodiment of the present invention provides a computer-readable storage medium having stored thereon computer program instructions for causing a machine to execute the above-described method of drive control of a hybrid vehicle.

The embodiment of the invention provides a processor for running a program, wherein the program is used for executing the method for driving and controlling the hybrid vehicle when running.

The present application also provides a computer program product adapted to perform a program of initializing the steps of the drive control method of a hybrid vehicle in an embodiment when executed on a data processing device.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

In a typical configuration, a computing device includes one or more processors (CPUs), input/output interfaces, network interfaces, and memory.

The memory may include forms of volatile memory in a computer readable medium, Random Access Memory (RAM) and/or non-volatile memory, such as Read Only Memory (ROM) or flash memory (flash RAM). The memory is an example of a computer-readable medium.

Computer-readable media, including both non-transitory and non-transitory, removable and non-removable media, may implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), Digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information that can be accessed by a computing device. As defined herein, a computer readable medium does not include a transitory computer readable medium such as a modulated data signal and a carrier wave.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in the process, method, article, or apparatus that comprises the element.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.