阅读说明：本技术 实现新能源电动汽车防溜坡保护控制的方法 (Method for realizing slope-sliding prevention protection control of new energy electric automobile ) 是由 肖浩 郑富辉 刘世猛 王俊 陈斌根 于 2020-06-22 设计创作，主要内容包括：本发明涉及一种实现新能源电动汽车防溜坡保护控制的方法,包括整车控制器获取整车状态信息；判断整车档位信息是否为前进挡；判断转速是否为负且大于阈值；触发电机控制器进入电流环固定转子位置角堵转防溜坡策略；等待1秒,判断转速绝对值是否大于阈值,如果是,则进入转速指令为零的转速环堵转防溜坡策略；否则,继续判断是否到达退出溜坡模式条件；等待1秒,判断是否到达退出溜坡模式条件；判断是否为后退档；判断转速是否为正且大于阈值。采用了本发明的实现新能源电动汽车防溜坡保护控制的方法,能够在不增加硬件成本的前提下,改变传统溜坡模式控制策略,结合转速环堵转以及电流环固定转子位置角堵转的优点,能够最大程度上减小溜坡模式下溜坡距离,保证整车行驶安全。(The invention relates to a method for realizing slope sliding prevention protection control of a new energy electric automobile, which comprises the steps that a vehicle control unit acquires vehicle state information; judging whether the gear information of the whole vehicle is a forward gear; judging whether the rotating speed is negative and is greater than a threshold value; triggering a motor controller to enter a position angle locked-rotor anti-slide strategy of a fixed rotor of a current loop; waiting for 1 second, judging whether the absolute value of the rotating speed is greater than a threshold value, and if so, entering a rotating speed ring-locked rotation slope slipping prevention strategy with a rotating speed instruction of zero; otherwise, continuously judging whether the condition of exiting the slope slipping mode is reached; waiting for 1 second, and judging whether the condition of exiting the slope slipping mode is reached; judging whether the gear is a reverse gear or not; and judging whether the rotating speed is positive and greater than a threshold value. By adopting the method for realizing the slope slipping prevention protection control of the new energy electric automobile, the traditional slope slipping mode control strategy can be changed on the premise of not increasing the hardware cost, and the slope slipping distance under the slope slipping mode can be reduced to the maximum extent by combining the advantages of rotating speed loop blocking and current loop fixed rotor position angle blocking, so that the running safety of the whole automobile is ensured.)

1. A method for realizing slope slipping prevention protection control of a new energy electric automobile is characterized by comprising the following steps:

(1) the vehicle controller acquires vehicle state information and feeds the vehicle state information back to the motor controller through the can bus, and the motor controller acquires current motor speed information and current motor rotor position information at the current moment;

(2) judging whether the gear information of the whole vehicle is a forward gear, if so, continuing to the step (3); otherwise, continuing the step (7);

(3) judging whether the rotating speed is negative and greater than a threshold value, if so, continuing to the step (4); otherwise, continuing the step (9);

(4) triggering the motor controller to enter a current loop fixed rotor position angle locked-rotor anti-slide strategy, and entering the step (5);

(5) waiting for 1 second, judging whether the absolute value of the rotating speed is greater than a threshold value, if so, entering a rotating speed ring blocking rotation anti-slip strategy with a rotating speed instruction of zero, and continuing to the step (6); otherwise, continuously judging whether the condition of exiting the slope slipping mode is reached, if so, continuing the step (9); otherwise, continuing the step (5);

(6) waiting for 1 second, judging whether the condition of exiting the slope slipping mode is reached, if so, continuing the step (9); otherwise, continuing the step (6);

(7) judging whether the gear is a reverse gear or not, if so, continuing to the step (8); otherwise, continuing the step (9);

(8) judging whether the rotating speed is positive and larger than a threshold value, if so, continuing to the step (4); otherwise, continuing the step (9);

(9) and executing according to the current finished automobile instruction, and exiting the step.

2. The method for realizing the slope slipping prevention protection control of the new energy electric automobile as claimed in claim 1, wherein the step (4) specifically comprises the following steps:

(4.1) the motor controller acquires the position information of the motor rotor at the moment through the rotary transformer, and finds the closest position angle information to ensure that the locked-rotor single-phase current is minimum, wherein the angle information is used for the Abc _ dq coordinate transformation and the position information of SVPWM wave-sending input;

and (4.2) switching the output of the torque loop to the output of the current loop by the motor controller, and giving a properly fixed d-axis current to ensure that the whole vehicle has enough torque to enter a locked-rotor working condition so as to keep the vehicle body fixed.

3. The method for realizing the slope slipping prevention protection control of the new energy electric automobile as claimed in claim 1, wherein the condition of detecting whether the slope slipping exiting mode is reached is that the total automobile output command torque is larger than the maximum torque of the current output, or a hand brake signal is effective, or a brake signal is effective, or gear information is changed.

4. The method for realizing the slope slipping prevention protection control of the new energy electric vehicle as claimed in claim 2, wherein the closest position information in the step (4.1) is 30 degrees, 90 degrees, 150 degrees, 210 degrees, 270 degrees or 330 degrees.

5. The method for realizing the slope slipping prevention protection control of the new energy electric automobile as claimed in claim 2, wherein the d-axis current in the step (4.2) is 30% of the peak current of the motor.

6. The method for realizing the slope slipping prevention protection control of the new energy electric automobile according to claim 1, wherein the vehicle state information in the step (1) comprises accelerator pedal information, gear information, hand brake and brake pedal information.

Technical Field

The invention relates to the field of new energy electric automobiles, in particular to the field of slope sliding prevention protection control, and specifically relates to a method for realizing slope sliding prevention protection control of a new energy electric automobile.

Background

When the electric automobile is started on a slope, a driver needs to switch an accelerator pedal and a brake pedal, and the phenomenon that the automobile slips backwards due to the fact that the driver is in different habits and improper operation can occur, so that driving safety is affected.

The traditional slope sliding protection control strategy is as follows: an inclination angle sensor is added, and a rotating speed ring blocking method is adopted:

the slope slipping protection is realized by adding the inclination angle sensor, namely slope slipping control is realized by acquiring the current vehicle elevation angle information, vehicle gear information, accelerator pedal information and brake pedal information, when the inclination angle acquired by the inclination angle sensor exceeds a set threshold value, a vehicle gear is not in a neutral gear, an accelerator pedal signal is lower than the set threshold value, and a brake pedal signal and a hand brake signal are invalid, a slope slipping protection strategy is triggered, the method is high in precision, but hardware equipment needs to be additionally added, so that the hardware cost is increased;

in addition, the slope slipping protection strategy is a rotating speed loop blocking method, compared with the method of increasing an inclination angle sensor, elevation angle information is changed into rotating speed information, the slope slipping protection strategy is triggered when the current rotating speed direction is inconsistent with the gear demand direction and the rotating speed exceeds a threshold value, the method belongs to double closed loop control, although the inclination angle sensor is omitted, the stable time is prolonged, the slope slipping distance is increased, the control stability is influenced by the rotating speed loop and the current loop PI parameter, and the control difficulty is increased.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a method for realizing the slope-sliding prevention protection control of the new energy electric automobile, which has the advantages of low control difficulty, simple and convenient operation and wide application range.

In order to achieve the purpose, the method for realizing the slope slipping prevention protection control of the new energy electric automobile comprises the following steps:

the method for realizing the slope slipping prevention protection control of the new energy electric automobile is mainly characterized by comprising the following steps of:

(1) the vehicle controller acquires vehicle state information and feeds the vehicle state information back to the motor controller through the can bus, and the motor controller acquires current motor speed information and current motor rotor position information at the current moment;

(2) judging whether the gear information of the whole vehicle is a forward gear, if so, continuing to the step (3); otherwise, continuing the step (7);

(3) judging whether the rotating speed is negative and greater than a threshold value, if so, continuing to the step (4); otherwise, continuing the step (9);

(4) triggering the motor controller to enter a current loop fixed rotor position angle locked-rotor anti-slide strategy, and entering the step (5);

(5) waiting for 1 second, judging whether the absolute value of the rotating speed is greater than a threshold value, if so, entering a rotating speed ring blocking rotation anti-slip strategy with a rotating speed instruction of zero, and continuing to the step (6); otherwise, continuously judging whether the condition of exiting the slope slipping mode is reached, if so, continuing the step (9); otherwise, continuing the step (5);

(6) waiting for 1 second, judging whether the condition of exiting the slope slipping mode is reached, if so, continuing the step (9); otherwise, continuing the step (6);

(7) judging whether the gear is a reverse gear or not, if so, continuing to the step (8); otherwise, continuing the step (9);

(8) judging whether the rotating speed is positive and larger than a threshold value, if so, continuing to the step (4); otherwise, continuing the step (9);

(9) and executing according to the current finished automobile instruction, and exiting the step.

Preferably, the step (4) specifically includes the following steps:

(4.1) the motor controller acquires the position information of the motor rotor at the moment through the rotary transformer, and finds the closest position angle information to ensure that the locked-rotor single-phase current is minimum, wherein the angle information is used for the Abc _ dq coordinate transformation and the position information of SVPWM wave-sending input;

and (4.2) switching the output of the torque loop to the output of the current loop by the motor controller, and giving a properly fixed d-axis current to ensure that the whole vehicle has enough torque to enter a locked-rotor working condition so as to keep the vehicle body fixed.

Preferably, the condition of detecting whether the vehicle is in the exit slope slipping mode is that the vehicle output command torque is larger than the maximum torque output by the current, or the hand brake signal is effective, or the gear information is changed.

Preferably, the closest position information in the step (4.1) is 30 degrees, 90 degrees, 150 degrees, 210 degrees, 270 degrees, 330 degrees.

Preferably, the d-axis current in the step (4.2) is 30% of the peak current of the motor.

Preferably, the vehicle state information in step (1) includes accelerator pedal information, gear information, handbrake and brake pedal information.

By adopting the method for realizing the slope slipping prevention protection control of the new energy electric automobile, the traditional slope slipping mode control strategy can be changed on the premise of not increasing the hardware cost, and the slope slipping distance under the slope slipping mode can be reduced to the maximum extent by combining the advantages of rotating speed loop blocking with a rotating speed instruction of zero and current loop fixed rotor position angle blocking, so that the running safety of the whole automobile is ensured.

Drawings

Fig. 1 is a control flow chart of a slope slipping mode of the method for realizing slope slipping prevention protection control of the new energy electric vehicle.

Fig. 2 is a slope signal input block diagram of the method for realizing the slope slide prevention protection control of the new energy electric vehicle.

Fig. 3 is a block diagram of slope slipping and rotation blocking control of the method for realizing slope slipping prevention protection control of the new energy electric vehicle.

Detailed Description

In order to more clearly describe the technical contents of the present invention, the following further description is given in conjunction with specific embodiments.

The invention discloses a method for realizing slope slipping prevention protection control of a new energy electric automobile, which comprises the following steps:

(1) the vehicle controller acquires vehicle state information and feeds the vehicle state information back to the motor controller through the can bus, and the motor controller acquires current motor speed information and current motor rotor position information at the current moment;

(2) judging whether the gear information of the whole vehicle is a forward gear, if so, continuing to the step (3); otherwise, continuing the step (7);

(3) judging whether the rotating speed is negative and greater than a threshold value, if so, continuing to the step (4); otherwise, continuing the step (9);

(4) triggering the motor controller to enter a current loop fixed rotor position angle locked-rotor anti-slide strategy, and entering the step (5);

(4.1) the motor controller acquires the position information of the motor rotor at the moment through the rotary transformer, and finds out the closest position angle information to ensure that the locked-rotor single-phase current is minimum, wherein the angle information is used for the Abc _ dq coordinate transformation and the position information of SVPWM wave-sending input, and is shown in a figure (3);

(4.2) the motor controller is switched from the output of the torque loop to the output of the current loop, and d-axis current which is properly fixed is given, so that the whole vehicle has enough torque to enter a locked-rotor working condition, and the vehicle body is kept fixed

(5) Waiting for 1 second, judging whether the absolute value of the rotating speed is greater than a threshold value, if so, entering a rotating speed ring blocking rotation anti-slip strategy with a rotating speed instruction of zero, and continuing to the step (6); otherwise, continuously judging whether the condition of exiting the slope slipping mode is reached, if so, continuing the step (9); otherwise, continuing the step (5);

(6) waiting for 1 second, judging whether the condition of exiting the slope slipping mode is reached, if so, continuing the step (9); otherwise, continuing the step (6);

(7) judging whether the gear is a reverse gear or not, if so, continuing to the step (8); otherwise, continuing the step (9);

(8) judging whether the rotating speed is positive and larger than a threshold value, if so, continuing to the step (4); otherwise, continuing the step (9);

(9) and executing according to the current finished automobile instruction, and exiting the step.

As a preferred embodiment of the present invention, the condition of detecting whether the vehicle has reached the exit downhill sliding mode is that the vehicle output command torque is larger than the maximum torque of the current output, or the hand brake signal is valid, or the gear information is changed.

In a preferred embodiment of the present invention, the closest position information in the step (4.1) is 30 degrees, 90 degrees, 150 degrees, 210 degrees, 270 degrees, or 330 degrees.

In a preferred embodiment of the present invention, the d-axis current in step (4.2) is 30% of the peak current of the motor.

As a preferred embodiment of the present invention, the vehicle state information in step (1) includes accelerator pedal information, gear information, handbrake and brake pedal information.

In a specific embodiment of the invention, the invention provides a novel slope slipping protection control method, and an improvement strategy is provided on the basis of a rotating speed ring rotation blocking strategy with a rotating speed instruction of zero, so that the slope slipping distance can be reduced to the maximum extent on the premise of not increasing the hardware cost, and the slope slipping safety is improved.

The difficulty of slope sliding protection control is how to ensure that the slope sliding phenomenon does not occur or the slope sliding distance is shortened as much as possible under the conditions that the depth of an accelerator pedal is not enough and a brake pedal and a hand brake signal are invalid under non-neutral gears. The traditional slope slipping control strategy adopts a rotating speed loop control mode with a rotating speed instruction of zero, and after entering a slope slipping mode, the rotating speed loop controls the motor to output at zero rotating speed, which is equivalent to rotating speed loop locked-rotor output.

The locked-rotor mode has the rotating speed ring locked-rotor with a rotating speed instruction of zero and the position angle locked-rotor of the current ring fixed rotor, the rotating speed ring mode locked-rotor with a rotating speed instruction of zero has accurate locked-rotor output torque and can ensure the locked-rotor effect to the maximum extent, but because the vehicle body belongs to a large inertia system and the rotating speed ring control system belongs to double closed-loop regulation (the inner loop is a current ring), the rotating speed ring has slower response and prolongs the slope sliding distance, the current ring locked-rotor has the advantages of short response time and simple control, but the position angle locked-rotor of the current ring fixed rotor belongs to open-loop locked-rotor, the locked-rotor output torque is not only influenced by the input current of the degree rotation but also influenced by the actual position of the rotor, if the vehicle load is larger or the slope is steeper, the locked-rotor fails under the condition of insufficient input locked,

based on the above, the method combines the advantages of the two, the current loop is started to fix the rotor position angle for locked rotor firstly in the slope slipping mode, and if the locked rotor fails (the slope is too large or the vehicle body is too heavy) after a period of time, the rotation speed loop with the rotation speed instruction of zero is started for locked rotor, so that the defect of slow response of the traditional slope slipping prevention control method can be avoided, and the phenomenon of vehicle slipping caused by relatively small output torque of the current loop can be avoided.

As shown in fig. 2 below, the present invention changes the control strategy, after entering into the hill-drop mode, the controller first enters into the current loop fixed rotor position angle locked-rotor strategy, and only gives the fixed d-axis current Id _ l and the fixed rotor position angle Theta _ l, which make the maximum value of the phase current minimum under the d-axis output current, for example, the d-axis current of 100A is given, and the q-axis current is given 0, and according to the current vector relationship, the phase current minimum output is 86.6A under the position information of 0 degree to 360 degrees, and these position information are: the method comprises the steps of measuring the rotation speed of a motor at the moment by 30 degrees, 90 degrees, 150 degrees, 210 degrees, 270 degrees and 330 degrees, ensuring the lowest calorific value of the rotation blockage, detecting the rotation speed of the motor at the moment after a period of time, such as 1s, if the rotation speed is less than 10rpm, successfully blocking the rotation of a current loop, not starting a rotation speed loop blockage strategy with a rotation speed instruction of zero, and if the rotation speed is negative and is greater than a set threshold value of 10rpm, entering the rotation speed loop blockage strategy with the rotation speed instruction of zero.

The invention discloses a method for realizing slope slipping prevention protection control of a new energy electric automobile, which comprises the following steps:

vehicle control unit acquires whole vehicle state information, includes: the method comprises the following steps that information of an accelerator pedal, gear information, a hand brake and a brake pedal is fed back to a motor controller through a can bus, and the motor controller obtains motor rotating speed information and current motor rotor position information at the current moment;

when the gear information of the whole vehicle is a forward gear, the rotating speed of a motor is negative and exceeds a set threshold value, triggering a motor controller to enter a slope slipping mode, or when the gear information of the whole vehicle is that the rotating speed of a reverse gear motor is positive and exceeds the set threshold value, triggering the motor controller to enter the slope slipping mode;

after entering the slope sliding mode, the motor controller acquires the position information of the rotor of the motor at the moment through the rotary transformer, finds the closest position information to ensure that the locked-rotor single-phase current is minimum, and fixes Theta _ ref to 30 degrees if the acquired rotor position is 20 degrees, for example.

The motor controller is switched from torque ring output to current ring output, a proper fixed d-axis current is given, in order to ensure that the whole vehicle has enough torque to enter locked rotor, the given d-axis current is set to be 30% of the peak current of the motor, for example, the given current amplitude is 500A under the condition of outputting the maximum torque, the current of the locked rotor is given to be 150A, the motor enters the locked rotor working condition, and the vehicle body is kept fixed.

And monitoring the rotating speed of the rotor at an interval of 1s, immediately switching to rotating speed ring locked-rotor control if the absolute value of the rotating speed is greater than a threshold value, entering the step 6, maintaining the step 5 if the absolute value of the rotating speed is less than the threshold value, and detecting whether the condition of exiting the slope is met.

Inputting a zero rotating speed reference value to enable the motor to enter a rotating speed ring locked-rotor mode, and detecting whether a condition of exiting a slope slipping mode is met at intervals of 1 s;

and if the depth of the accelerator pedal exceeds the maximum torque value under the current output at the moment, or the brake signal is effective, or the hand brake signal is effective, or the gear information is changed, the hill-sliding mode is exited, and the controller outputs the torque according to the vcu instruction.

The invention discloses a slope slipping protection control method for a new energy electric automobile, which comprises the following steps: A. entering condition signal acquisition in a slope slipping mode; B. current loop and combined slope slip control strategy; C. and exiting the slope slipping control mode.

The invention combines the advantages of two locked-rotor control methods of a rotating speed ring and a current ring, and can avoid the defect of slow response of the traditional slope sliding control method. On the premise of not increasing any hardware cost, a novel slope slipping mode control strategy is realized, and the driving effects of fast slope slipping control and small vehicle slipping distance are achieved.

The specific embodiment of the invention is as follows:

taking a permanent magnet synchronous motor with a peak rotating speed of 8000rpm, a peak torque of 200Nm and a current amplitude of 500A under the output peak torque as an example, if the maximum output torque under the 150A phase current output is 70N.

Firstly, judging whether to enter a slope slipping mode according to gear information and rotating speed information, and triggering the slope slipping mode if the gear is a forward gear and the rotating speed of a motor is-15 rpm at the moment.

After entering a slope slipping mode, acquiring that the current rotor position angle is 20 degrees, firstly entering a current ring fixed rotor position angle blocking strategy, giving d-axis output current 150A, giving a rotor position angle 30 degrees, outputting fixed vector current by a motor at the moment, sucking the rotor, detecting the rotor speed after 1 second, if the rotor speed is-2 rpm after 1 second, determining that the blocking is successful, detecting vcu to send an output torque command and gear information and hand brake and brake pedal signals, if the vcu output torque is more than 70Nm or the gear information is changed or the hand brake signal is effective or the brake pedal signal is effective, exiting the slope slipping mode, outputting according to the whole vehicle command, otherwise, continuing the current ring fixed rotor position angle blocking, and continuously detecting the rotor speed;

if the rotating speed of the rotor is greater than-10 rpm, a rotating speed ring blocking strategy is entered, the rotating speed is controlled to be 0, an output torque command and gear information are continuously detected and sent vcu, if the output torque vcu is greater than the rotating speed ring blocking output torque, or the gear information is changed, or a hand brake signal is effective, or a brake pedal signal is effective, the slope slipping mode is exited, the output is carried out according to the whole vehicle command, otherwise, the rotating speed ring is continuously maintained.

By adopting the method for realizing the slope slipping prevention protection control of the new energy electric automobile, the traditional slope slipping mode control strategy can be changed on the premise of not increasing the hardware cost, and the slope slipping distance under the slope slipping mode can be reduced to the maximum extent by combining the advantages of rotating speed loop blocking with a rotating speed instruction of zero and current loop fixed rotor position angle blocking, so that the running safety of the whole automobile is ensured.

In this specification, the invention has been described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.