CN113895424B

CN113895424B - Starting control method of P2 framework transmission system

Info

Publication number: CN113895424B
Application number: CN202111131668.6A
Authority: CN
Inventors: 赵伟伟; 严鉴铂; 刘义; 王凯峰; 张晨光; 冯浩成; 杨瑄; 郑泽奇; 黄晨晨; 丁斌
Original assignee: Xian Fast Auto Drive Co Ltd
Current assignee: Xian Fast Auto Drive Co Ltd
Priority date: 2021-09-26
Filing date: 2021-09-26
Publication date: 2023-06-13
Anticipated expiration: 2041-09-26
Also published as: CN113895424A

Abstract

According to the starting control method of the transmission system with the P2 framework, the magnitude of a starting load is judged in an algebraic comparison mode of an accelerator opening coefficient and a gradient coefficient, when large-load sliding friction starting or creeping is needed, the rotating speed of the C0 clutch is controlled to be in a certain range through the mode of combining the C0 clutch and the C1 clutch, the sliding friction of the C1 clutch is controlled through controlling the oil pressure of the built-in C1 clutch, the rotating speed of a motor is always kept above the chargeable minimum running rotating speed, the sliding friction rotating speed of the C1 built-in clutch is controlled to be in a certain range, the sliding friction load is further reduced, and the starting/creeping requirements of the hybrid power transmission can be met under the condition that the built-in clutch structure of the transmission body C1 is not changed.

Description

Starting control method of P2 framework transmission system

Technical Field

The invention relates to the technical field of hybrid power transmission control, in particular to a starting control method of a transmission system of a P2 framework.

Background

The traditional starting method of the hybrid power transmission with the P2 framework comprises the following steps that firstly, a hydraulic torque converter is used for starting, and when the hybrid power transmission is started, the hybrid power vehicle is matched with the hydraulic torque converter, but the axial length of the transmission is increased, the transmission efficiency of the hybrid power is reduced, and the cost is increased; the second is pure electric starting, the noise is low, the torque is high, and when the electric quantity is insufficient, the third mode, namely clutch friction starting, is adopted, and a clutch is generally arranged as a friction clutch to carry out friction starting.

The clutch slip starting method is mainly divided into two types, namely a C0 clutch positioned between a motor and a traditional power source (such as an engine) and a C1 clutch built in a transmission body for starting. When the C0 clutch is adopted for starting, the C0 clutch is used as a starting clutch when an engine is started and is also used as a starting clutch when the engine is started, but when a low-power mode vehicle starts or runs in a creeping mode, the rotating speed of a motor at the rear end of the clutch is too low to charge a battery under the working condition of starting or long-time creeping.

When the built-in C1 clutch of the transmission is adopted for starting, a clutch shared by a starting gear or a creeping gear is generally selected as a starting clutch, and the C1 clutch is used as a power transmission unit in the traditional transmission, and the sliding working condition is not considered, so that the re-design of the built-in C1 clutch is required to meet the sliding working condition requirement. However, the C1 clutch is already a mature design, the peripheral expansion space is limited, the optimization design is difficult, the parts around the C1 are required to be redesigned, the cost is high, and the period is long. Moreover, the clutch cannot be combined in the prior art, and the same clutch is used for starting no matter any starting working condition, so that the clutch is single in form.

Based on the above, a starting control method of a hybrid power transmission system with a P2 architecture needs to be designed, and different clutches are adopted as a starting scheme of the starting clutch according to different working conditions.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a starting control method of a transmission system of a P2 framework.

The invention is realized by the following technical scheme:

a starting control method of a P2 framework transmission system comprises a transmission, a motor arranged at the front end of an input shaft of the transmission, a C0 clutch arranged at the front end of the motor, an engine arranged at the front end of the C0 clutch and a C1 clutch arranged in the transmission;

when the vehicle is in a power shortage state, an engine driving mode is adopted, a starting load is obtained to judge the vehicle, and when the load is larger than a preset value A, a front C0 clutch and a built-in C1 clutch are combined to finish starting or creeping of the vehicle, and the specific method is as follows:

regulating the rotating speed of the engine to a set value, and controlling the oil pressure of the C0 clutch and the oil pressure of the C1 clutch to enable the built-in C1 clutch and the built-in C0 clutch to be in a sliding friction state, so that the vehicle starts;

when the slip of the rotating speed of the output end and the rotating speed of the input end of the built-in C1 clutch is in a set range, the oil pressure of the C1 clutch is controlled, so that the locking of the C1 clutch is finished, the slip of the C0 clutch is adopted to continuously reduce the rotating speed difference between the rotating speed of the engine and the rotating speed of the C0 clutch, and when the rotating speed difference is reduced to be in the set range, the C0 clutch is locked, and the starting of the vehicle is completed.

Preferably, when the C0 clutch is in a sliding friction state, the oil pressure of the C0 clutch is controlled to enable the rotating speed of the output end of the C0 clutch to be constant, so that the rotating speed of the motor is always maintained above the lowest running rotating speed of charging.

Preferably, the method for judging the starting load is as follows:

acquiring a throttle opening coefficient and a gradient coefficient;

when the throttle opening coefficient or/and the gradient coefficient is/are larger than the corresponding preset value, algebraic summation of the throttle opening coefficient and the gradient coefficient is carried out, when the result is smaller than the preset value A, an idle starting signal is output, and when the result is larger than the preset value A, starting or creeping of the vehicle is completed by combining a front C0 clutch with a built-in C1 clutch.

Preferably, when the throttle opening coefficient and the gradient coefficient are smaller than the corresponding preset values, the C1 clutch is adopted to start in a sliding mode or to perform creeping.

Preferably, the method for judging when the vehicle is in the power shortage state comprises the following steps:

acquiring electric quantity information of a vehicle storage battery, and when the electric quantity is lower than a preset SOC value, enabling the vehicle to be in a power shortage state;

and when the electric quantity is higher than a preset SOC value, the electric quantity is driven by adopting an EV mode or HEV mode.

Preferably, in the engine driving mode, main oil pressure is established for the hydraulic unit of the hybrid power transmission system through the electronic oil pump, an engine ignition signal is input to the motor, an engine ignition program is entered, the motor is operated, and the engine is started through sliding friction of the C0 clutch.

Preferably, after the engine is started and runs smoothly, the C0 clutch is engaged, power of the engine is transmitted to the motor, and the storage battery is charged through the motor.

Compared with the prior art, the invention has the following beneficial technical effects:

Compared with the existing single clutch for starting or creeping sliding friction operation, the invention provides a theory of limiting the starting power of C1 by combining the C0 clutch and the C1 clutch, and maximally reduces the design change of the transmission, thereby realizing the motor charging operation under creeping and starting working conditions.

Drawings

FIG. 1 is a schematic diagram of a P2 architecture hybrid transmission of the present invention;

FIG. 2 is a control flow chart of the starting method of the present invention

FIG. 3 is a flowchart of a start load determination according to the present invention;

FIG. 4 is a schematic diagram of the rotational speeds of the combined launch of the C0 and C1 clutches of the present invention

In the figure: 01. a vehicle controller; 02. a valve sensor; 03. an engine control unit; 04. a battery controller; 05. a motor controller; 06. an electronic oil pump control unit; 07. a transmission controller; 08. a transmission; 09. a storage battery; 10. an electronic oil pump; 11. a gradient sensor; 12. an engine; 13. a C0 clutch; 14. a motor; 15. a C1 clutch; 16. an output shaft.

Detailed Description

The invention will now be described in further detail with reference to the accompanying drawings, which illustrate but do not limit the invention.

Referring to fig. 1, a transmission system of a P2 architecture includes an engine 12 and a motor 14 as power inputs, the motor 14 is electrically connected with a battery 09 via an inverter, the motor 14 and the battery 09 are respectively in communication with a whole vehicle controller 01 through a motor controller 05 and a battery controller 04, and the engine 12 is in communication with the whole vehicle controller 01 through an engine control unit 03.

The motor 14 is disposed at the front end of the transmission 08 and is rigidly connected to the input end of the transmission 08, and the engine 12 is connected to the motor 14 via a C0 clutch 13, with the C0 clutch 13 being used to effect power transmission and interruption between the motor 14 and the engine 12.

The inside of the transmission 08 is provided with a C1 clutch 15, the transmission 08 is connected with an output shaft 16 through certain speed change motion and outputs power, the transmission 08 is provided with an electronic oil pump 10, the electronic oil pump 10 is connected with an electronic oil pump control unit 06, the control of the electronic oil pump 10 is realized, the transmission 08 is connected with a transmission controller 07, the electronic oil pump control unit 06 and the transmission controller 07 are both connected with a whole vehicle control system 01, the communication of the whole vehicle control system 01 and the transmission control system 07 is realized, and oil pressure is established for a hydraulic unit of the transmission in a state that the transmission does not operate.

The transmission 08 is integrated with the gradient sensor 11, the gradient sensor 11 and the transmission controller 07 are communicated, and gradient signals of the vehicle are interacted with the transmission controller 07 and the whole vehicle controller 01 in real time through the CAN bus.

The C1 clutch 15 is a necessary clutch required for starting or creeping of the vehicle, and the C0 clutch 13 and the C1 clutch 15 realize linear adjustment of control pressure.

The transmission 08 is a continuously variable transmission, a dual clutch transmission, or an AT transmission.

The clutch C0 is a wet multi-plate clutch or a dry clutch.

The clutch C1 is a wet multi-plate clutch, so that accurate torque transmission is facilitated.

Referring to fig. 2 and 3, a method for controlling start of a transmission system with a P2 architecture, when a battery 09 corresponding to the hybrid power transmission system is in a low power mode and cannot be started purely electrically or is creeping, determines to use the C1 clutch 15 to start by sliding friction, or uses a C0 clutch to start by sliding friction in combination with the C1 clutch, and after determining according to a start strategy, starts a vehicle by sliding friction of the clutch, specifically includes the following steps:

step S101, switching on a power supply, and completing self-checking of the vehicle;

step S102, judging whether the battery electric quantity of the storage battery 09 of the vehicle is lower than a preset SOC value, if so, entering step S103, otherwise, entering step S104;

step S103, the vehicle enters an engine driving mode;

step S104, entering a pure electric mode EV or a hybrid mode HEV mode;

step S105, the electronic oil pump 10 is operated to establish a main oil pressure for the hydraulic unit of the hybrid power transmission system;

in step S106, an engine ignition signal is input to the electric motor 14, the engine ignition program is entered, the electric motor 14 is operated, and the engine is started by the sliding friction of the C0 clutch 13.

Step S107, after the engine runs stably, the C0 clutch 13 is combined, and the motor 14 can receive the power transmitted by the engine 12 to charge the storage battery 09;

step S108, receiving a starting signal, entering a starting load judging program, enabling the starting load to be smaller than a preset value, entering step S109, enabling the starting load to be larger than the preset value, and entering step S110;

step S109, adjusting the oil pressure of a built-in C1 clutch of the transmission;

step S110, oil pressure of the C1 clutch and the C0 clutch is adjusted;

step S111, when the starting load is smaller than a preset value, the C1 clutch 15 is used for sliding friction starting or creeping;

step S112, when the starting load is larger than a preset value, the front C0 clutch 13 and the built-in C1 clutch 15 are combined for use, and starting or creeping of the vehicle is completed;

step S113, which is a step of judging whether the vehicle start is completed, and if the vehicle speed is greater than the vehicle speed when the engine 12 is idling, proceeding to step S114, closing the clutch, and completing the vehicle start, otherwise, proceeding to step S108 to dynamically monitor the load.

In the specific embodiment, step S108 is a program for determining the starting load of the vehicle, and the whole vehicle controller 01 comprehensively determines the starting load of the vehicle by reading the throttle opening signal transmitted by the throttle sensor 02 and the gradient signal transmitted by the gradient sensor 11, and specifically includes the following steps.

Step S201, the vehicle receives a starting signal, reads an opening signal of a throttle valve, and starts a distribution range of load from only lifting a brake pedal, not giving the opening signal of the throttle valve until the throttle valve is started fully, wherein a load coefficient can be quantified through a formulated assignment strategy, if the load coefficient is larger than a preset value, the step S202 is entered, otherwise, the step S203 is entered;

step S202, algebraic summation of throttle opening coefficient and gradient coefficient;

step S203, reading a gradient signal value, converting the gradient value into a gradient coefficient through a certain strategy, entering step S204 if the gradient value is smaller than a preset value, and entering step S202 if the gradient coefficient is larger than the preset value;

step S204, judging that the starting load coefficient of the vehicle is smaller than a preset value, outputting an idle starting signal, and ending the starting load judgment;

step S205, if the algebraic sum of the throttle opening coefficient and the gradient coefficient is smaller than a preset value, the step S204 is performed, and if the algebraic sum is larger than the preset value, the step S206 is performed;

step S206, outputting a load signal, and ending the starting load judgment.

The main purpose of starting the C1 clutch 15 and the C0 clutch 13 in step S112 is to reduce the sliding load of the C1 built-in clutch 15 while ensuring that the rotational speed of the motor 14 is always maintained above the chargeable minimum running rotational speed under the vehicle starting or creeping conditions, and the specific implementation method is as follows.

Fig. 4 shows a rotational speed change process of starting by sliding friction between the C0 clutch 13 and the C1 clutch 15, in this embodiment, the starting rotational speed of the engine is set to 2000rpm, and in the first stage, the rotational speed of the engine is rapidly increased to the set target rotational speed, and the rotational speed of the output end of the C0 clutch is constantly maintained above the chargeable minimum running rotational speed by controlling the control oil pressure of the C0 clutch and the C1 clutch, so that the rotational speed of the motor 14 is always maintained, and at this time, both the built-in C1 clutch 15 and the C0 clutch 13 are in a sliding friction state, so that the vehicle is rapidly started.

In the second stage, when the slip between the rotational speed of the output end and the rotational speed of the input end of the built-in C1 clutch is within a certain range delta _r1 When the oil pressure of the C1 clutch 15 is controlled to lock the C1 clutch and finish sliding friction, at the moment, the output end of the C0 clutch and the rotating speed of the engine still have rotating speed difference, and the rotating speed difference delta between the rotating speed of the engine 12 and the rotating speed of the C0 clutch 13 is continuously reduced by virtue of the sliding friction of the C0 clutch 13 _r2 When the rotational speed difference is reduced to be within the set range, the C0 clutch 13 is locked, and the entire starting process ends.

The P2 framework hybrid power transmission system comprises a transmission, a motor arranged at the front end of an input shaft of the transmission, a C0 clutch arranged at the front end of the motor, a power source arranged at the front end of the C0 clutch and a C1 clutch arranged in the transmission. The power source is connected and disconnected with the input end of the transmission and the motor rotor through the C0 clutch, and the motor rotor and the input shaft of the transmission are kept in a fixed connection state. The C1 clutch is a necessary clutch required when the vehicle starts or runs in a creeping condition, and the C0 clutch and the C1 clutch can realize linear adjustment of control pressure.

When the whole vehicle battery corresponding to the hybrid power transmission system is in a low power mode and cannot be started in a pure electric mode or in a creeping mode, the method for starting by adopting the C0 clutch in a sliding mode or the C0+C1 clutch in a sliding mode is judged by judging the size of a starting load, and after a starting strategy is determined, the vehicle is started by the sliding mode of the clutch.

The starting control method is to set a starting clutch C0 arranged in front of the hybrid power motor and a starting clutch C1 arranged behind the hybrid power motor and internally provided with a transmission, and different clutches are adopted as a starting scheme of the starting clutch according to different working conditions. When the vehicle starts steadily or is in a creeping state, namely the starting load is smaller, the vehicle starts in a sliding friction mode or creep mode through the rear-mounted C1 clutch, and when the engine needs to be started or a large accelerator is required to start in the running process of the vehicle, namely the starting load is larger, the inherent defect problem existing in starting operation by adopting a single clutch is solved through the mode of combining the C0 clutch and the built-in C1 clutch.

According to the invention, the magnitude of a starting load is judged by algebraic comparison of the accelerator opening coefficient and the gradient coefficient, when large-load sliding friction starting or creeping is needed, the rotating speed of the C0 clutch is controlled to be in a certain range through the mode of combining sliding friction of the C0 clutch 13 and the C1 clutch 15, the sliding friction of the C1 clutch is controlled through controlling the oil pressure of the built-in C1 clutch, the rotating speed of the motor 14 is always kept above the chargeable minimum running rotating speed, and the sliding friction rotating speed of the C1 built-in clutch 15 is controlled to be in a certain range, so that the sliding friction load is reduced, and the starting/creeping requirement of the hybrid power transmission can be met under the condition that the built-in clutch structure of the transmission body C1 is not changed.

The above is only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited by this, and any modification made on the basis of the technical scheme according to the technical idea of the present invention falls within the protection scope of the claims of the present invention.

Claims

1. The starting control method of the transmission system of the P2 framework is characterized in that the transmission system comprises a transmission, a motor arranged at the front end of an input shaft of the transmission, a C0 clutch arranged at the front end of the motor, an engine arranged at the front end of the C0 clutch and a C1 clutch arranged in the transmission;

when the vehicle is in a power shortage state, an engine driving mode is adopted, a starting load is obtained to judge the vehicle, and when the load is larger than a preset value A, a front C0 clutch (13) and a built-in C1 clutch (15) are combined to finish the starting or creeping of the vehicle, and the specific method is as follows:

regulating the rotation speed of the engine to a set value, and controlling the oil pressure of the C0 clutch and the oil pressure of the C1 clutch to enable the built-in C1 clutch (15) and the built-in C0 clutch (13) to be in a sliding friction state, so that the vehicle starts;

when the slip of the rotating speed of the output end and the rotating speed of the input end of the built-in C1 clutch is in a set range, controlling the oil pressure of the C1 clutch (15) to ensure that the locking of the C1 clutch is finished, adopting the slip of the C0 clutch (13) to continuously reduce the rotating speed difference between the rotating speed of the engine (12) and the rotating speed of the C0 clutch (13), and when the rotating speed difference is reduced to be in the set range, locking the C0 clutch (13) to finish the starting of the vehicle;

when the C0 clutch (13) is in a sliding friction state, the oil pressure of the C0 clutch is controlled to enable the rotating speed of the output end of the C0 clutch to be constant, so that the rotating speed of the motor (14) is always maintained above the lowest running rotating speed of charging.

2. The method for controlling start of a P2 architecture transmission system according to claim 1, wherein the method for determining a start load is as follows:

acquiring a throttle opening coefficient and a gradient coefficient;

when the throttle opening coefficient or/and the gradient coefficient is/are larger than the corresponding preset value, algebraic summation of the throttle opening coefficient and the gradient coefficient is carried out, when the result is smaller than the preset value A, an idle starting signal is output, and when the result is larger than the preset value A, starting or creeping of the vehicle is completed by combining the front C0 clutch (13) and the built-in C1 clutch (15).

3. The start control method of a P2 architecture driveline of claim 1, wherein when the throttle opening coefficient and the gradient coefficient are both less than respective corresponding preset values, a C1 clutch (15) is used to perform a skid start or a creep start.

4. The method for controlling start of a P2 architecture transmission system according to claim 1, wherein the method for determining when the vehicle is in a power shortage state is as follows:

5. A start control method of a P2 architecture driveline as claimed in claim 1, wherein an engine driving mode is employed, wherein a main oil pressure is established for a hybrid driveline hydraulic unit via an electronic oil pump, an engine ignition signal is input to an electric motor (14), an engine ignition program is entered, the electric motor (14) is operated, and the engine is started via sliding friction of a C0 clutch (13).

6. A start control method of a P2 architecture driveline as recited in claim 5, wherein after the engine is started and running smoothly, the C0 clutch (13) is engaged to transfer the power of the engine to the motor (14) and the battery (09) is charged by the motor.