阅读说明：本技术 一种含转角差估计的驻车挂档控制方法 (Parking gear-shifting control method with rotation angle difference estimation ) 是由 卢紫旺 田光宇 黄勇 于 2021-09-07 设计创作，主要内容包括：本发明公开了属于电动汽车换档控制技术领域的一种含转角差估计的驻车挂档控制方法。包括步骤1：通过对换档电机的控制实现接合套到达接合位置时具有小轴向速度；步骤2：若接合套与接合齿圈转角差发生变动,则转向步骤3,若接合套已越过接合齿圈倒角,则转向步骤5,若经过时间t-(chm)后,接合套仍处于接合位置,则转向步骤4；步骤3：估计接合套与接合齿圈转角差；步骤4：通过控制驱动电机转矩实现接合套与接合齿圈“转角对齐”；步骤5：通过对换档电机的控制实现接合套与接合齿圈的接合。本发明方法可以确定驻车状态时接合套与接合齿圈的转角差；可在接合套与接合齿圈接合前实现“零转速差、零转角差”；可实现近乎零冲击挂档。(The invention discloses a parking gear-shifting control method with rotation angle difference estimation, belonging to the technical field of electric automobile gear-shifting control. Comprises the following steps of 1: the small axial speed is realized when the joint sleeve reaches the joint position through the control of the gear shifting motor; step 2: if the difference between the rotational angles of the engaging sleeve and the engaging ring gear fluctuates, the process goes to step 3, if the engaging sleeve has crossed the chamfer of the engaging ring gear, the process goes to step 5, and if the time t elapses chm After that, the joint sleeve is still at the joint position, turning to the step 4; and step 3: estimating a rotation angle difference between the joint sleeve and the joint gear ring; and 4, step 4: the rotation angle alignment between the joint sleeve and the joint gear ring is realized by controlling the torque of the driving motor; and 5: the engagement of the engaging sleeve with the engaging ring gear is achieved by the control of the shifting motor. The method can determine the rotation angle difference between the joint sleeve and the joint gear ring in the parking state;zero rotation speed difference and zero rotation angle difference can be realized before the joint sleeve is jointed with the joint gear ring; nearly zero impact gear shifting can be achieved.)

1. A parking gear control method with rotation angle difference estimation is characterized by comprising the following steps:

step 1: employing Bang-Bang control for a shift motor to ensure a small axial velocity v of the clutch collar when it reaches the engaged position_chm；

Step 2: judging the displacement s of the joint sleeve_slvWhether or not it is equal to or greater than the displacement s of the engaging sleeve to the engaged position_slv1If yes, turning to the step 3; if not, turning to the step 1;

and step 3: determining the difference between the rotation angles of the engaging sleeve and the engaging gear ringIf the change occurs, turning to the step 4; if not, go to step 5;

and 4, step 4: estimating the angular difference between the engaging sleeve and the engaging ring gear by using the circumferential angular difference variation occurring when the engaging sleeve and the engaging ring gear are pressed and the current axial displacement of the engaging sleeveThen go to step 6;

and 5: judging whether the time t required by the joint sleeve to pass through the chamfer is simultaneously met or not is larger than the expected time t required by the joint sleeve to pass through the chamfer_chmAnd displacement of the joint sleeve s_slvLess than or equal to the displacement s of the engaging sleeve to the engaging position_slv1If yes, go to step 6; if not, go to step 8;

step 6: adjusting the difference in the angle of rotation of the sleeve and ring gear using Bang-like four-stage controlTo perform corner alignment; then go to step 7;

and 7: judging whether the difference delta omega between the rotating speeds of the joint sleeve and the joint gear ring is satisfied at the same time_{gr_slv}Is less than or equal to the allowable range delta omega of the rotation speed difference, and the periodical rotation angle difference between the joint ring gear and the joint sleeveIf the allowable range of the rotation angle difference δ θ is smaller than or equal to the allowable range of the rotation angle difference δ θ,go to step 9; if not, go to step 6;

and 8: judging the displacement s of the joint sleeve_slvWhether or not it is greater than or equal to the displacement s of the joint sleeve passing through the chamfer_chmDisplacement s of the sleeve to the engaged position_slv1If yes, go to step 9; if not, turning to the step 3;

and step 9: adopting Bang-Bang control to the gear shifting motor to enable the joint sleeve to be directly jointed with the joint gear ring and ensure that the joint sleeve does not collide with the joint gear ring; then, turning to the step 10;

step 10: judging whether the speed v of the joint sleeve is satisfied simultaneously_slvNot more than the allowable range δ v of the sleeve speed, and the sleeve displacement s_slvMore than or equal to l/2- δ s, wherein l is the travel of the engaging sleeve from the original gear to the target gear, and δ s is the displacement allowable range of the engaging sleeve; if yes, ending; if not, go to step 9.

2. Parking gear control method with estimation of the difference in rotation angle according to claim 1, characterized in that said small axial speed v_chmThe determination method of (2) is as follows:

in the formula, s_chmAxial displacement required for the joint sleeve to pass through the chamfer, t_chmThe desired time required for the clutch collar to traverse the chamfer.

3. The method for controlling parking gear according to claim 1, wherein said step 3 is performed based on the difference between the rotation angle of the clutch sleeve at the upper chamfer positionComprises the following steps:

in the formula, h_grTo engage the tooth length of the ring gear, b_grFor engaging the tooth width of the toothed ring, α_grFor engaging gear-ring chamfers, N_grThe number of teeth that engage the ring gear;

difference in angle of rotation of the sleeve in the lower chamfer positionComprises the following steps:

4. the parking gear control method with estimation of rotation angle difference according to claim 1, characterized in that the estimated rotation angle difference of the engaging sleeve and the engaging ring gear in step 4Comprises the following steps:

in the formula, δ θ_{gr_slv}＝θ_gr-θ_slv，θ_grTo engage the angle of rotation of the ring gear, theta_slvIs the corner of the engaging sleeve.

5. The parking gear control method with the estimation of the rotation angle difference according to claim 1, wherein the Bang-Bang control in step 1 and step 9 is controlled according to the law

In the formula (I), the compound is shown in the specification, in order to provide equivalent inertia for the shift actuator,for equivalent damping of the shift actuator, r_aFor the equivalent radius of the shift actuator,in order to shift the maximum torque of the motor,is the target displacement of the engaging sleeve.

6. The method for controlling parking gear according to claim 1, wherein the Bang-like four-stage control in step 6 is controlled according to a control law

In the formula (I), the compound is shown in the specification,in order to drive the motor target torque command,the maximum torque of the driving motor.

Technical Field

The invention relates to the technical field of gear shifting control of pure electric vehicles, extended range electric vehicles and parallel and series-parallel hybrid electric vehicles, in particular to a parking gear shifting control method with rotation angle difference estimation.

Background

The direct connection system of the motor and the mechanical transmission without the synchronizer cancels the clutch and the synchronizer, has high efficiency and low cost, can effectively reduce the comprehensive cost of the electric automobile, is an ideal electric drive system configuration, has attracted wide attention in the industry in recent years, and is increasingly applied to pure electric automobiles and hybrid electric automobiles.

The control of an electrically driven mechanical transmission can be divided mainly into two situations, namely a driving gear shift and a parking gear shift. When the parking gear is engaged, if the new vehicle is engaged for the first time, the initial rotation angle difference between the joint sleeve and the joint gear ring cannot be determined; if the vehicle is dragged due to a fault, the difference between the rotation angles of the joint sleeve and the joint gear ring is uncertain, so that the angle required to be adjusted by the driving motor cannot be determined, and finally, the situation that gear beating is serious or even gear shifting cannot be successfully carried out in the gear shifting process occurs. To address this challenge, the present invention proposes a parking gear control method with a rotational angle difference estimation for an electrically driven mechanical transmission system with chamfers on the sleeve and ring gear to achieve an almost zero impact parking gear.

Disclosure of Invention

The invention aims to provide a parking gear control method with a rotation angle difference estimation, which is characterized by comprising the following steps:

step 1: employing Bang-Bang control for a shift motor to ensure a small axial velocity v of the clutch collar when it reaches the engaged position_chm；

Step 2: judging the displacement s of the joint sleeve_slvWhether or not it is equal to or greater than the displacement s of the engaging sleeve to the engaged position_slv1If yes, turning to the step 3; if not, turning to the step 1;

and step 3: determining the difference between the rotation angles of the engaging sleeve and the engaging gear ringIf the change occurs, turning to the step 4; if not, go to step 5;

and 4, step 4: estimating the angular difference between the engaging sleeve and the engaging ring gear by using the circumferential angular difference variation occurring when the engaging sleeve and the engaging ring gear are pressed and the current axial displacement of the engaging sleeveThen go to step 6;

and 5: judging whether the time t required by the joint sleeve to pass through the chamfer is simultaneously met or not is larger than the expected time t required by the joint sleeve to pass through the chamfer_chmAnd displacement of the joint sleeve s_slvLess than or equal to the displacement s of the engaging sleeve to the engaging position_slv1If yes, go to step 6; if not, go to step 8;

step 6: adjusting the difference in the angle of rotation of the sleeve and ring gear using Bang-like four-stage controlTo perform corner alignment; then go to step 7;

and 7: judging whether the difference delta omega between the rotating speeds of the joint sleeve and the joint gear ring is satisfied at the same time_{gr_slv}Is less than or equal to the allowable range delta omega of the rotation speed difference, and the periodical rotation angle difference between the joint ring gear and the joint sleeveIf the rotation angle difference is smaller than or equal to the allowable rotation angle difference range delta theta, turning to the step 9; if not, go to step 6;

and 8: judging the displacement s of the joint sleeve_slvWhether or not it is greater than or equal to the displacement s of the joint sleeve passing through the chamfer_chmDisplacement s of the sleeve to the engaged position_slv1If yes, go to step 9; if not, turning to the step 3;

and step 9: adopting Bang-Bang control to the gear shifting motor to enable the joint sleeve to be directly jointed with the joint gear ring and ensure that the joint sleeve does not collide with the joint gear ring; then, turning to the step 10;

step 10: judging whether the speed v of the joint sleeve is satisfied simultaneously_slvNot more than the allowable range δ v of the sleeve speed, and the sleeve displacement s_slvMore than or equal to l/2- δ s, wherein l is the travel of the engaging sleeve from the original gear to the target gear, and δ s is the displacement allowable range of the engaging sleeve; if yes, ending; if not, go to step 9.

Said small axial velocity v_chmThe determination method of (2) is as follows:

in the formula, s_chmAxial displacement required for the joint sleeve to pass through the chamfer, t_chmThe desired time required for the clutch collar to traverse the chamfer.

The difference of the rotation angle when the joint sleeve is at the upper chamfering position in the step 3Comprises the following steps:

in the formula, h_grTo engage the tooth length of the ring gear, b_grFor engaging the tooth width of the toothed ring, α_grFor engaging gear-ring chamfers, N_grThe number of teeth that engage the ring gear;

difference in angle of rotation of the sleeve in the lower chamfer positionComprises the following steps:

the estimated difference in rotation angle between the engaging sleeve and the engaging ring gear in step 4Comprises the following steps:

in the formula, δ θ_{gr_slv}＝θ_gr-θ_slv，θ_grIn order to engage the corner of the ring gear,θ_slvis the corner of the engaging sleeve.

The control law of Bang-Bang control in the step 1 and the step 9 is

In the formula (I), the compound is shown in the specification,in order to provide equivalent inertia for the shift actuator,for equivalent damping of the shift actuator, r_aFor the equivalent radius of the shift actuator,in order to shift the maximum torque of the motor,is the target displacement of the engaging sleeve.

The control law of the Bang-like four-stage control in the step 6 is

In the formula (I), the compound is shown in the specification,in order to drive the motor target torque command,the maximum torque of the driving motor.

The invention has the beneficial effects that:

1. the parking gear shifting control method comprises the steps of estimating the rotation angle difference between the joint sleeve and the joint gear ring, and determining the rotation angle difference between the joint sleeve and the joint gear ring in the parking state;

2. the parking gear-shifting control method comprises the circumferential 'rotation angle alignment' control of the joint sleeve and the joint gear ring, and can realize 'zero rotation speed difference and zero rotation angle difference' before the joint sleeve is jointed with the joint gear ring;

3. the parking gear-shifting control method can realize almost zero-impact gear shifting.

Drawings

FIG. 1 is a flow chart of a parking gear control including an estimation of a rotational angle difference;

FIG. 2 is a schematic view of the relationship between the axial displacement and the angular difference of the engaging sleeve;

FIG. 3 is a diagram of a clutch collar and clutch ring profile;

FIG. 4 is a schematic diagram illustrating an estimation of a variation direction of a rotation angle difference;

fig. 5 is a diagram of a parking gear control case with a rotation angle difference estimation.

Detailed Description

The invention provides a parking gear control method with a rotation angle difference estimation, and the invention is further explained by combining the accompanying drawings and specific embodiments.

Fig. 1 is a flow chart of parking gear control with estimation of the difference of the rotation angle, comprising the following steps:

step 1: employing Bang-Bang control for a shift motor to ensure a small axial velocity v of the clutch collar when it reaches the engaged position_chm；

Step 2: judging the displacement s of the joint sleeve_slvWhether or not it is equal to or greater than the displacement s of the engaging sleeve to the engaged position_slv1If yes, turning to the step 3; if not, turning to the step 1;

and step 3: determining the difference between the rotation angles of the engaging sleeve and the engaging gear ringIf the change occurs, turning to the step 4; if not, go to step 5;

and 4, step 4: estimating the angular difference between the engaging sleeve and the engaging ring gear by using the circumferential angular difference variation occurring when the engaging sleeve and the engaging ring gear are pressed and the current axial displacement of the engaging sleeveThen go to step 6;

and 5: judging whether the time t required by the joint sleeve to pass through the chamfer is simultaneously met or not is larger than the expected time t required by the joint sleeve to pass through the chamfer_chmAnd displacement of the joint sleeve s_slvLess than or equal to the displacement s of the engaging sleeve to the engaging position_slv1If yes, go to step 6; if not, go to step 8;

step 6: adjusting the difference in the angle of rotation of the sleeve and ring gear using Bang-like four-stage controlTo perform corner alignment; then go to step 7;

and 7: judging whether the difference delta omega between the rotating speeds of the joint sleeve and the joint gear ring is satisfied at the same time_{gr_slv}Is less than or equal to the allowable range delta omega of the rotation speed difference, and the periodical rotation angle difference between the joint ring gear and the joint sleeveIf the rotation angle difference is smaller than or equal to the allowable rotation angle difference range delta theta, turning to the step 9; if not, go to step 6;

and 8: judging the displacement s of the joint sleeve_slvWhether or not it is greater than or equal to the displacement s of the joint sleeve passing through the chamfer_chmDisplacement s of the sleeve to the engaged position_slv1If yes, go to step 9; if not, turning to the step 3;

and step 9: adopting Bang-Bang control to the gear shifting motor to enable the joint sleeve to be directly jointed with the joint gear ring and ensure that the joint sleeve does not collide with the joint gear ring; then, turning to the step 10;

step 10: judging whether the speed v of the joint sleeve is satisfied simultaneously_slvNot more than the allowable range δ v of the sleeve speed, and the sleeve displacement s_slvMore than or equal to l/2- δ s, wherein l is the travel of the engaging sleeve from the original gear to the target gear, and δ s is the displacement allowable range of the engaging sleeve; if yes, ending; if not, go to step 9.

Due to the simple structure of the shift actuator, the Bang-Bang control law obtained by the simplified linear system can be used to control the shift motor to achieve the above-mentioned object in order to quickly reach the engaged position and have a small axial speed. Wherein the control law of Bang-Bang control is

In the formula (I), the compound is shown in the specification,in order to provide equivalent inertia for the shift actuator,for equivalent damping of the shift actuator, r_aFor the equivalent radius of the shift actuator,in order to shift the maximum torque of the motor,is the target displacement of the engaging sleeve.

The specific value of the small axial velocity may be determined based on the desired time and the axial displacement required for the engaging sleeve to traverse the chamfer. E.g. the required displacement for crossing a chamfer is s_chmThe desired time is t_chmThen the small axial velocity is:

if the angular difference between the joint sleeve and the joint gear ring changes, estimating the angular difference between the joint sleeve and the joint gear ring by using the circumferential angular difference change generated when the joint sleeve and the joint gear ring are extruded and the current axial displacement of the joint sleeve; if the joint sleeve has crossed the joint gear ring chamfer, the joint of the joint sleeve and the joint gear ring is realized through the control of the gear shifting motor; if the time t elapses_chmThen, the joint sleeve is still in the joint position, and the joint sleeve is pressed against the tooth tip of the joint gear ring, and the rotation angle difference is pi/N_grThen through controlThe torque of the driving motor realizes the 'rotation angle alignment' of the joint sleeve and the joint gear ring;

if there is a difference in the rotational angle between the engaging sleeve and the engaging ring gear, the engaging sleeve collides with the engaging ring gear when moving at a small axial speed. As shown in fig. 2, when the engaging sleeve abuts the engaging ring gear on the chamfer, it can be displaced s according to the engaging sleeve_slvAnd determining that the position of the joint sleeve, which is abutted against the joint gear ring, is at an upper chamfer position (I) or a lower chamfer position (II), namely that the axial displacement of the same joint sleeve corresponds to two possible rotation angle differences. If the clutch collar is in position (r), the difference in rotation angle is:

in the formula (I), the compound is shown in the specification,for the difference between the angle of rotation of the engaging sleeve and that of the engaging toothed ring, N_grIs the number of teeth that engage the ring gear. Other symbols can be seen in FIG. 3, h_grTo engage the tooth length of the ring gear, b_grFor engaging the tooth width of the toothed ring, α_grFor engaging gear-ring chamfers, s_slvIndicating the axial displacement of the coupling sleeve, s, with neutral position as zero_slv1Indicating a displacement from the neutral position to the engaged position of the engagement sleeve. And l is the stroke of the engaging sleeve from the original gear to the target gear.

If the position is in the position II, the rotation angle difference is as follows:

it can be determined whether the first position or the second position is based on the direction of the variation of the angle difference, as shown in fig. 4. Let the variation of the angle difference be delta theta_{gr_slv}＝θ_gr-θ_slv，θ_grAnd theta_slvThe rotation angles of the engaging ring gear and the engaging sleeve, respectively, the estimated difference in rotation angles of the engaging sleeve and the engaging ring gear is:

after the rotational angle difference between the engaging sleeve and the engaging gear ring is obtained by the estimation method, the torque of the driving motor can be controlled according to the rotational angle difference to realize the 'rotational angle alignment' between the engaging sleeve and the engaging gear ring. For example, to achieve rapid 'angle alignment', the driving motor can utilize Bang-like four-stage control to adjust the angle difference between the engaging sleeve and the engaging gear ring, and the control law is

In the formula (I), the compound is shown in the specification,in order to drive the motor target torque command,the maximum torque of the driving motor.

When the rotation angles of the engaging sleeve and the engaging gear ring are aligned, the gear shifting motor can be controlled to enable the engaging sleeve to be directly engaged with the engaging gear ring without collision between the engaging sleeve and the engaging gear ring, and the successful gear shifting is ensured. For example, to ensure the shortest time clutch sleeve is "angle aligned" with the engaged ring gear, the shift motor may use Bang-Bang control to bring the clutch sleeve to the target gear in the shortest time and at zero speed, the control result of which is shown in fig. 5.

The present invention is not limited to the above embodiments, and any changes or substitutions that can be easily made by those skilled in the art within the technical scope of the present invention are also within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.