A control method for the catapult start of a hybrid vehicle

Abstract

A control method for the catapult start of a hybrid vehicle, including catapult start enabling judgment, catapult start control, catapult start engine speed control, catapult start wheel side torque control, and hybrid controller signal interaction control. If the vehicle enters the catapult start state after passing the catapult start enabling judgment, the catapult start is controlled through the catapult start control, the engine speed is controlled through the catapult start engine speed control, the wheel side torque is controlled through the catapult start wheel side torque control, and the vehicle control unit VCU performs signal interaction with the motor control unit PCU and the engine management system EMS through the hybrid controller signal interaction control.

Description

Technical Field

[0001] The present invention relates to the technical field of automotive engines, and particularly to a control method for the catapult start of a hybrid vehicle. Background Art

[0002] Catapult start is an acceleration technology that uses a transmission to adjust the engine speed to the output platform of the maximum torque, so that at the moment of vehicle start, the engine outputs the maximum torque immediately to achieve the best acceleration. If catapult start is used, at the moment of vehicle start, the engine can output the maximum torque, and the acceleration is very rapid, which can give users more driving pleasure.

[0003] Currently, most of the common catapult start control methods on the market are complex in operation, may require stepping on the pedal multiple times, or have a certain risk of accidental touch. In addition, since the starting processes of the vehicle's engine and motor during catapult start are different from those in normal driving, a large amount of manual operation and debugging are required, which is time-consuming and laborious. Summary of the Invention

[0004] In view of this, the present invention provides a control method for the catapult start of a hybrid vehicle that is simple in operation and not prone to accidental touch.

[0005] The control method for the catapult start of the hybrid vehicle provided by the present invention includes catapult start enable judgment, catapult start control, catapult start engine speed control, catapult start wheel-side torque control, and hybrid controller signal interaction control. If the vehicle enters the catapult start state after passing the catapult start enable judgment, then the catapult start is controlled through the catapult start control, the engine speed is controlled through the catapult start engine speed control, the wheel-side torque is controlled through the catapult start wheel-side torque control, and the vehicle control unit VCU performs signal interaction with the motor control unit PCU and the engine management system EMS through the hybrid controller signal interaction control.

[0006] Further, the catapult start enable judgment includes the following steps:

[0007] Step S1: Judge whether the gear is in the forward gear and whether the current vehicle speed is less than the vehicle speed threshold. If the gear is in the forward gear and the current vehicle speed is less than the vehicle speed threshold, then enter Step S2;

[0008] Step S2: Judge whether the catapult start switch of the vehicle is pressed. If the vehicle is equipped with a catapult start switch and the catapult start switch is pressed, then enter the catapult start control. If the vehicle is equipped with a catapult start switch and the catapult start switch is not pressed, then enter Step S3;

[0009] Step S3: Determine whether the throttle opening is greater than the throttle opening threshold and whether the brake pedal opening is greater than the brake pedal opening threshold. If the throttle opening is greater than the throttle opening threshold and the brake pedal opening is greater than the brake pedal opening threshold, enter the launch control.

[0010] Further, in the step S2, if the vehicle does not have a launch switch, enter the step S3.

[0011] Further, the launch control includes the following steps:

[0012] Step S4: Send a command to the instrument, and the instrument reminds the user that the launch has been enabled and pay attention to safety;

[0013] Step S5: Control the engine to start and load torque, and enter the launch engine start control and the launch wheel torque control;

[0014] Step S6: Determine whether the opening of the brake pedal is zero within the first preset time. If the opening of the brake pedal reaches zero at any time point within the first preset time, the vehicle starts with a launch.

[0015] Further, in the step S6, the first preset time is a calibrated value. If the opening of the brake pedal does not reach zero within the first preset time, cancel the launch and the engine start.

[0016] Further, the launch engine start control includes the following steps:

[0017] Step S7: The vehicle control unit (VCU) controls the engine to start. After the engine completes fuel injection and ignition, the VCU controls the engine to run at the first engine speed.

[0018] Further, the first engine speed is a calibrated value, and its range is between 1200 rpm and 3000 rpm.

[0019] Further, the launch wheel torque control includes the following steps:

[0020] Step S8: The vehicle control unit (VCU) calculates the wheel torque demand, obtains the motor torque demand and / or the motor torque demand according to the wheel torque demand, and distributes the wheel torque demand to the engine and / or the motor.

[0021] Further, in the step S8, the vehicle control unit (VCU) can calculate the wheel torque demand by looking up a table according to the throttle opening, or use the maximum wheel torque that the system can output as the wheel torque demand.

[0022] Further, the hybrid controller signal interaction control includes:

[0023] When the vehicle enters the catapult start state, the vehicle control unit (VCU) can send a user reminder instruction to the instrument panel to remind the user that the catapult start has been enabled and to pay attention to safety;

[0024] The vehicle control unit (VCU) can send the motor torque demand to the power control unit (PCU) of the motor. After receiving the motor torque demand, the power control unit (PCU) of the motor controls the motor to output the corresponding torque according to the motor torque demand and feeds back the actual torque of the motor to the vehicle control unit (VCU);

[0025] The vehicle control unit (VCU) can send the engine torque demand to the engine management system (EMS). After receiving the engine torque demand, the engine management system (EMS) controls the engine to output the corresponding torque according to the engine torque demand and feeds back the actual torque of the engine to the vehicle control unit (VCU).

[0026] In summary, the present invention judges and controls the catapult start of the vehicle through catapult start enable judgment, catapult start control, catapult start engine speed control, and catapult start wheel-side torque control. Through the signal interaction control of the hybrid controller, the interaction between the vehicle control unit (VCU), the power control unit (PCU) of the motor, the engine management system (EMS), and the instrument panel is realized. While realizing the catapult start function of the hybrid vehicle and providing stronger starting power performance, it gives users more driving pleasure. The catapult start control method of the hybrid vehicle of the present invention does not require the user to continuously step on the brake pedal multiple times. It can be started as long as the catapult start switch is pressed or the accelerator pedal and the brake pedal are stepped on simultaneously. It is easy to operate and not prone to accidental triggering.

[0027] The above description is only an overview of the technical solution of the present invention. In order to be able to understand the technical means of the present invention more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features, and advantages of the present invention more obvious and understandable, the following specific preferred embodiments are given and described in detail in conjunction with the accompanying drawings. Brief Description of the Drawings

[0028] Figure 1 It is a schematic diagram of the catapult start enable judgment provided by the present invention.

[0029] Figure 2 It is a schematic diagram of the catapult start control provided by the present invention.

[0030] Figure 3 It is a schematic diagram of the catapult start engine speed control provided by the present invention.

[0031] Figure 4 It is a schematic diagram of the catapult start wheel-side torque control provided by the present invention.

[0032] Figure 5Schematic diagram of signal interaction control of the hybrid power controller provided by the present invention. Specific embodiments

[0033] To further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the present invention will be described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0034] The catapult start control method for a hybrid vehicle of the present invention includes catapult start enable judgment, catapult start control, catapult start engine speed control, catapult start wheel side torque control, and hybrid power controller signal interaction control. If the vehicle enters the catapult start state after passing the catapult start enable judgment, the catapult start is controlled through catapult start control, the engine speed is controlled through catapult start engine speed control, the wheel side torque is controlled through catapult start wheel side torque control, and the vehicle control unit VCU performs signal interaction with the motor control unit PCU and the engine management system EMS through hybrid power controller signal interaction control.

[0035] Please refer to Figure 1 , in the present invention, the catapult start enable judgment includes the following steps:

[0036] Step S1: Determine whether the current gear is a forward gear and whether the current vehicle speed is less than the vehicle speed threshold. If the current gear is a forward gear and the current vehicle speed is less than the vehicle speed threshold, then enter Step S2;

[0037] Step S2: Determine whether the catapult start switch of the vehicle is pressed. If the vehicle has a catapult start switch and the catapult start switch is pressed, then enter catapult start control. If the vehicle has a catapult start switch but the catapult start switch is not pressed, then enter Step S3;

[0038] Step S3: Determine whether the throttle opening is greater than the throttle opening threshold and whether the brake pedal opening is greater than the brake pedal opening threshold. If the throttle opening is greater than the throttle opening threshold and the brake pedal opening is greater than the brake pedal opening threshold, then enter catapult start control.

[0039] Specifically, in Step S1, the vehicle speed threshold is a calibrated value. In this embodiment, the vehicle speed threshold is calibrated to 10 km / h; in Step S2, since not all vehicle models will be equipped with a catapult start switch, if the vehicle does not have a catapult start switch, then Step S2 can be skipped and directly enter Step S3; in Step S3, both the throttle opening threshold and the pedal opening threshold are calibrated values. In this embodiment, the throttle opening threshold is calibrated to 80%, and the brake pedal opening threshold is calibrated to 80%. In other embodiments, the brake pedal opening being greater than the brake pedal opening threshold can also be replaced by the brake master cylinder pressure being greater than the brake master cylinder pressure threshold, and the brake master cylinder pressure threshold is calibrated to the brake master cylinder pressure value corresponding to a brake pedal opening of 80%.

[0040] Please refer to Figure 2 simultaneously, the launch control includes the following steps:

[0041] Step S4: Send an instruction to the instrument to remind the user that the launch control has been enabled and pay attention to safety;

[0042] Step S5: Control the engine to start and load torque, and enter the launch engine start control and the launch wheel torque control;

[0043] Step S6: Determine whether the opening of the brake pedal is zero within the first preset time. If the opening of the brake pedal reaches zero at any time point within the first preset time, the vehicle will perform a launch.

[0044] Specifically, Step S4 and Step S5 are executed simultaneously after the launch enable judgment; the launch engine start control and the launch wheel torque control in Step S5 can be executed simultaneously, or the execution order can be adjusted according to the vehicle model, as long as they are executed before the vehicle performs a launch; in Step S6, the first preset time is a calibrated value, which is calibrated to 10 seconds in this embodiment, and the time point when the first preset time starts to be timed is the time point when the vehicle control unit (VCU) controls the engine to start. If the opening of the brake pedal reaches zero at any time point within the first preset time, that is, the brake pedal is completely released within 10 seconds, the vehicle will perform a launch; if the opening of the brake pedal does not reach zero within the first preset time, that is, the brake pedal is held down for more than 10 seconds and not completely released, the launch and the engine start will be cancelled, achieving the purpose of saving energy and protecting the engine.

[0045] Please refer to Figure 3 simultaneously, the launch engine start control includes the following steps:

[0046] Step S7: The vehicle control unit (VCU) controls the engine to start. After the engine completes fuel injection and ignition, the vehicle control unit (VCU) controls the engine to operate at the first engine speed.

[0047] Specifically, in Step S7, the first engine speed is a calibrated value. In this embodiment, the first engine speed is calibrated to a value between 1200 rpm and 3000 rpm, which is much higher than the starting engine speed of a conventional vehicle. The conventional vehicle starting method needs to drag the engine to start during driving, and needs to overcome the reverse drag torque of the engine. Therefore, the wheel torque will decrease during the engine starting process, which may cause the vehicle to jerk and affect the driving experience. The launch control starts the engine in place while the driver holds the brake pedal and does not release it, so that there is no engine starting process during the starting and accelerating process, and there is no jerk, which has better power performance. Once the vehicle starts, it will accelerate rapidly.

[0048] Please refer to Figure 4 simultaneously. The in-wheel torque control for launch control includes the following steps:

[0049] Step S8: The vehicle control unit (VCU) calculates the in-wheel torque requirement, obtains the engine torque requirement and / or motor torque requirement based on the in-wheel torque requirement, and distributes the in-wheel torque requirement to the engine and / or motor.

[0050] Specifically, in step S8, the VCU can calculate the in-wheel torque requirement by looking up a table according to the throttle opening, or use the maximum in-wheel torque that the system can output as the in-wheel torque requirement. In a conventional vehicle start, the in-wheel torque usually has an increasing process lasting about several hundred milliseconds from the actual start of the vehicle to reaching the target value, while in launch control, the in-wheel torque is loaded to the target value when the engine starts in place, providing better power performance.

[0051] Please refer to Figure 5 simultaneously. The signal interaction control of the hybrid controller includes:

[0052] When the vehicle enters the launch control state, the VCU can send a user reminder command to the instrument panel to remind the user that the launch control has been enabled and to pay attention to safety;

[0053] The VCU can send the motor torque requirement to the power control unit (PCU) of the motor. After receiving the motor torque requirement, the PCU controls the motor to output the corresponding torque according to the motor torque requirement and feeds back the actual torque of the motor to the VCU;

[0054] The VCU can send the engine torque requirement to the engine management system (EMS). After receiving the engine torque requirement, the EMS controls the engine to output the corresponding torque according to the engine torque requirement and feeds back the actual torque of the engine to the VCU.

[0055] In summary, the present invention judges and controls the vehicle's launch control through launch control enabling judgment, launch control, launch control engine speed control, and in-wheel torque control for launch control, and realizes the interaction between the VCU, the PCU of the motor, the EMS, and the instrument panel through the signal interaction control of the hybrid controller. While realizing the launch control function of the hybrid vehicle and providing stronger starting power performance, it gives users more driving pleasure. The launch control method of the hybrid vehicle of the present invention does not require the user to continuously step on the brake pedal multiple times. It can be activated as long as the launch control switch is pressed or the accelerator pedal and the brake pedal are stepped on simultaneously. It is easy to operate and not easily mis-triggered.

[0056] The above are only the preferred embodiments of the present invention and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the relevant art can make some changes or modifications within the scope of the technical solution of the present invention to form equivalent embodiments with equivalent changes. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A control method for the catapult start of a hybrid vehicle, characterized in that: The hybrid vehicle boost start control method includes boost start enable judgment, boost start control, boost start engine speed control, boost start wheel side torque control, and hybrid controller signal interaction control. If the vehicle enters the boost start state after the boost start enable judgment, the boost start is controlled through the boost start control, the engine speed is controlled through the boost start engine speed control, the wheel side torque is controlled through the boost start wheel side torque control, and the vehicle control unit VCU performs signal interaction with the motor control unit PCU and the engine management system EMS through the hybrid controller signal interaction control. The boost start enable judgment includes the following steps: Step S1: Judge whether the gear is in the forward gear and whether the current vehicle speed is less than the vehicle speed threshold. If the gear is in the forward gear and the current vehicle speed is less than the vehicle speed threshold, go to step S2; Step S2: Judge whether the boost start switch of the vehicle is pressed. If the vehicle is equipped with a boost start switch and the boost start switch is pressed, enter the boost start control. If the vehicle is equipped with a boost start switch and the boost start switch is not pressed, go to step S3; Step S3: Judge whether the throttle opening is greater than the throttle opening threshold and whether the brake pedal opening is greater than the brake pedal opening threshold. If the throttle opening is greater than the throttle opening threshold and the brake pedal opening is greater than the brake pedal opening threshold, enter the boost start control.

2. The control method for the hybrid vehicle's boost start according to claim 1, characterized in that: In step S2, if the vehicle is not equipped with a boost start switch, go to step S3.

3. The control method for the hybrid vehicle's catapult start according to claim 1, characterized in that: The boost start control includes the following steps: Step S4: Send an instruction to the instrument, and the instrument reminds the user that the boost start has been enabled and pay attention to safety; Step S5: Control the engine to start and load torque, and enter the boost start engine start control and the boost start wheel side torque control; Step S6: Judge whether the opening of the brake pedal is zero within the first preset time. If the opening of the brake pedal reaches zero at any time point within the first preset time, the vehicle performs a boost start.

4. The control method for the power-assisted vehicle's catapult start according to claim 3, characterized in that: In step S6, the first preset time is a calibrated value. If the opening of the brake pedal does not reach zero within the first preset time, the boost start and the engine start are cancelled.

5. The method for controlling the catapult start of a hybrid vehicle according to claim 3, characterized in that: The boost start engine start control includes the following steps: Step S7: The vehicle control unit VCU controls the engine to start. After the engine completes fuel injection and ignition, the vehicle control unit VCU controls the engine to run at the first engine speed.

6. The control method for the hybrid vehicle's catapult start according to claim 5, characterized in that: The first engine speed is a calibrated value, and its range is between 1200 rpm and 3000 rpm.

7. The control method for the hybrid vehicle's catapult start according to claim 3, characterized in that: The boost start wheel side torque control includes the following steps: Step S8: The vehicle control unit VCU calculates the wheel side torque demand, obtains the engine torque demand and / or the motor torque demand according to the wheel side torque demand, and distributes the wheel side torque demand to the engine and / or the motor.

8. The control method for the hybrid vehicle's catapult start according to claim 7, characterized in that: In step S8, the vehicle control unit VCU can calculate the wheel side torque demand by looking up a table according to the throttle opening, or use the maximum wheel side torque that the system can output as the wheel side torque demand.

9. The control method for the hybrid vehicle's launch control according to claim 1, characterized in that: The hybrid controller signal interaction control includes: When the vehicle enters the catapult start state, the vehicle control unit (VCU) sends a user reminder command to the instrument panel to remind the user that the catapult start has been enabled and to pay attention to safety; The vehicle control unit (VCU) sends the motor torque demand to the power control unit (PCU) of the motor. After receiving the motor torque demand, the power control unit (PCU) of the motor controls the motor to output the corresponding torque according to the motor torque demand and feeds back the actual torque of the motor to the vehicle control unit (VCU); The vehicle control unit (VCU) sends the engine torque demand to the engine management system (EMS). After receiving the engine torque demand, the engine management system (EMS) controls the engine to output the corresponding torque according to the engine torque demand and feeds back the actual torque of the engine to the vehicle control unit (VCU).

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