CN115431982A - Hill starting method and system based on automatic continuously variable transmission and vehicle - Google Patents
Hill starting method and system based on automatic continuously variable transmission and vehicle Download PDFInfo
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- CN115431982A CN115431982A CN202211199991.1A CN202211199991A CN115431982A CN 115431982 A CN115431982 A CN 115431982A CN 202211199991 A CN202211199991 A CN 202211199991A CN 115431982 A CN115431982 A CN 115431982A
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- 230000009194 climbing Effects 0.000 claims description 8
- 230000006641 stabilisation Effects 0.000 claims description 6
- 238000011105 stabilization Methods 0.000 claims description 5
- 230000003019 stabilising effect Effects 0.000 claims description 2
- 230000033228 biological regulation Effects 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000006073 displacement reaction Methods 0.000 description 2
- 239000000446 fuel Substances 0.000 description 2
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- 230000000694 effects Effects 0.000 description 1
- 238000004134 energy conservation Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000014509 gene expression Effects 0.000 description 1
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
- B60W30/00—Purposes of road vehicle drive control systems not related to the control of a particular sub-unit, e.g. of systems using conjoint control of vehicle sub-units
- B60W30/18—Propelling the vehicle
- B60W30/18009—Propelling the vehicle related to particular drive situations
- B60W30/18027—Drive off, accelerating from standstill
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
- B60W10/00—Conjoint control of vehicle sub-units of different type or different function
- B60W10/02—Conjoint control of vehicle sub-units of different type or different function including control of driveline clutches
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
- B60W10/00—Conjoint control of vehicle sub-units of different type or different function
- B60W10/04—Conjoint control of vehicle sub-units of different type or different function including control of propulsion units
- B60W10/06—Conjoint control of vehicle sub-units of different type or different function including control of propulsion units including control of combustion engines
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
- B60W2510/00—Input parameters relating to a particular sub-units
- B60W2510/06—Combustion engines, Gas turbines
- B60W2510/0604—Throttle position
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
- B60W2510/00—Input parameters relating to a particular sub-units
- B60W2510/06—Combustion engines, Gas turbines
- B60W2510/0638—Engine speed
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
- B60W2710/00—Output or target parameters relating to a particular sub-units
- B60W2710/02—Clutches
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
- B60W2710/00—Output or target parameters relating to a particular sub-units
- B60W2710/06—Combustion engines, Gas turbines
- B60W2710/0644—Engine speed
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- Control Of Transmission Device (AREA)
Abstract
The application discloses a hill start method, a hill start system and a vehicle based on an automatic continuously variable transmission, wherein the hill start method comprises the following steps: judging whether the vehicle is in a hill starting state or not; if yes, executing a hill starting auxiliary method based on a gearbox electronic control unit, wherein the hill starting auxiliary method comprises the following steps: receiving a current accelerator opening signal, and determining a first target rotating speed of the engine according to the current accelerator opening signal; when the clutch reaches the combination point, controlling the rotating speed of the engine to rise, controlling the load of the clutch to be below a first threshold value, and receiving the rotating speed information of the engine; if the rotating speed of the engine rises to a first target rotating speed, controlling the load of the clutch to increase, simultaneously reducing the rotating speed of the engine, and starting the vehicle to climb a slope; and when the rotating speed of the engine is reduced to the second target rotating speed, controlling the load of the clutch to stop increasing, and finishing hill starting. The problem of automatic continuously variable transmission motorcycle type hill start difficulty has been solved in this application.
Description
Technical Field
The application relates to the technical field of automobiles, in particular to a hill starting method and system based on an automatic continuously variable transmission and a vehicle.
Background
The automobile is a common phenomenon in hill starting, the requirement on the driving technique of a driver is high, and particularly for an automobile with a manual gear, the matching of an accelerator and a clutch pedal needs to be quite skillful. When the vehicle is started on a slope, the vehicle frequently slides and even stalls if the power is insufficient, so that the driver is highly nervous and is easy to cause safety accidents.
The hill start auxiliary function of the existing manual gear shifting gearbox (MT) vehicle type is that an engine Electronic Control Unit (ECU) firstly improves the initial target rotating speed by controlling an electronic throttle valve, then when a driver looses a clutch pedal, the electronic throttle valve is automatically controlled to increase the opening degree in the clutch combination process to perform air inflow compensation, the rotating speed of the engine is controlled, the load resistance of the vehicle when the clutch is combined is increased, and the vehicle is ensured to start smoothly.
At present, energy conservation and environmental protection are more and more emphasized, corresponding national fuel consumption regulations of passenger cars are continuously updated and perfected, and the fourth-stage standard GB27999-2014 of the passenger cars at present also requires that fuel consumption of the passenger cars meet requirements; in order to meet the domestic oil consumption requirement, each automobile manufacturer gradually adopts a small-displacement engine to reduce oil consumption and emission; the power performance of small displacement engines is naturally reduced and the challenge in hill starts will be greater.
For an automatic Continuously Variable Transmission (CVT) vehicle type, in order to ensure that the emission and the oil consumption of the vehicle meet the national regulation requirements, gear shifting lines of the CVT vehicle type are all made by preferentially considering an economic oil consumption area of an engine, and the rotating speed of the gear shifting lines is relatively low; in addition, the target rotational speed for starting is relatively low in consideration of reducing the noise at the time of starting the vehicle as much as possible. When the CVT vehicle is started on a hill, the ECU can not control and increase the engine torque when the CVT vehicle is started like the MT vehicle, but the TCU controls the engine torque by controlling the starting rotating speed, so that the CVT vehicle is easy to have insufficient starting torque due to low rotating speed when the CVT vehicle is started on a hill, and difficult hill starting is caused.
The main flow hill starting auxiliary control scheme of the CVT vehicle type at present is an uphill auxiliary system (HAC) derived based on a vehicle body stabilizing system (ESP), the main control body is the vehicle body stabilizing system (ESP), the main function is to prevent the vehicle from sliding backwards, the HAC does not have the function of strengthening the climbing capacity by increasing the torque of the vehicle, and therefore the problem that the CVT vehicle type is difficult to start on the hill can not be solved by the conventional HAC.
Disclosure of Invention
The application provides a hill start method and system based on an automatic stepless gearbox and a vehicle, wherein a gearbox electronic control unit implements a hill start auxiliary method, the rotating speed of an engine is quickly increased under a smaller clutch load, the clutch load is increased after the engine reaches sufficient torque, so that the start performance and the maximum climbing gradient are improved, and the problem of difficult hill start is solved.
The application provides a hill starting method based on an automatic continuously variable transmission, which comprises the following steps:
judging whether the vehicle is in a hill starting state or not;
if yes, executing a hill start assisting method based on a gearbox electronic control unit, wherein the hill start assisting method comprises the following steps:
receiving a current accelerator opening signal, and determining a first target rotating speed of the engine according to the current accelerator opening signal;
when the clutch reaches the combination point, controlling the rotating speed of the engine to rise, controlling the load of the clutch to be below a first threshold value, and receiving the rotating speed information of the engine;
if the rotating speed of the engine rises to a first target rotating speed, controlling the load of the clutch to increase, simultaneously reducing the rotating speed of the engine, and starting the vehicle to climb a slope;
when the rotating speed of the engine is reduced to a second target rotating speed, controlling the load of the clutch to stop increasing, and finishing hill starting;
wherein the first target rotational speed is greater than the second target rotational speed.
Preferably, the transmission electronic control unit controls the load of the clutch and the rotating speed of the engine through the opening degree of the accelerator.
Preferably, the method further comprises the steps of identifying whether a hill start assisting function switch based on the gearbox electronic control unit is turned on;
and if the vehicle is started and is in a hill-start state, executing a hill-start assisting method based on the gearbox electronic control unit.
Preferably, if the vehicle is on a hill, the brake of the vehicle is in a released state, the vehicle speed is less than the second threshold value, and the current gear of the vehicle is a forward gear, the vehicle is in a hill start state.
Preferably, the hill start assisting method based on the transmission electronic control unit is executed simultaneously with the uphill assisting method based on the vehicle body stabilizing system.
The application also provides a hill starting system based on the automatic stepless gearbox, which comprises an engine electric control unit, a vehicle body stabilizing system and a gearbox electric control unit;
the gearbox electric control unit is in signal connection with the engine electric control unit and the vehicle body stabilizing system through a CAN bus;
the gearbox electronic control unit judges whether the vehicle is in a hill starting state or not through a brake signal sent by the engine electronic control unit, a hill signal sent by the vehicle body stabilizing system and a gear signal recognized by the gearbox electronic control unit;
the electronic control unit of the gearbox comprises a hill start assisting module, wherein the hill start assisting module comprises a first target rotating speed determining module, a rotating speed control module, an engine rotating speed receiving module, a judging module and a load control module;
the first target rotating speed determining module is used for determining a first target rotating speed of the engine according to an accelerator opening degree signal sent by the engine electronic control unit;
the rotating speed control module is used for controlling the rotating speed of the engine to rise before the rotating speed of the engine rises to a first target rotating speed and controlling the rotating speed of the engine to fall after the rotating speed of the engine rises to the first target rotating speed;
the engine rotating speed receiving module is used for receiving rotating speed information sent by the engine electronic control unit;
the judging module is used for judging whether the rotating speed of the engine is increased to a first target rotating speed or not and whether the rotating speed of the engine is decreased to a second target rotating speed or not;
the load control module is used for controlling the load of the clutch to be below a first threshold value after the clutch reaches the junction point and before the rotating speed of the engine is increased to a first target rotating speed; the load control device is also used for controlling the load of the clutch to increase after the rotating speed of the engine rises to the first target rotating speed; the clutch is also used for controlling the load of the clutch to stop increasing when the rotating speed of the engine is reduced to a second target rotating speed, and finishing hill starting;
wherein the first target rotational speed is greater than the second target rotational speed.
Preferably, the rotation speed control module controls the load of the clutch and the rotation speed of the engine through the throttle opening.
Preferably, the transmission electronic control unit further comprises a hill start assist function switch.
Preferably, the body stabilising system further comprises an uphill assist module for operating simultaneously with the hill start assist module in a hill start condition.
The application also provides a vehicle based on the automatic continuously variable transmission, and the vehicle is used for executing the hill starting method based on the automatic continuously variable transmission.
Other features of the present application and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the application and together with the description, serve to explain the principles of the application.
FIG. 1 is a block diagram of an automated continuously variable transmission based hill start system as provided herein;
FIG. 2 is a flow chart of a hill start method based on an automatic continuously variable transmission as provided herein;
FIG. 3 is a flowchart of a hill start assist method based on a transmission electronic control unit provided by the present application;
FIG. 4 is a graph comparing engine speed and vehicle speed during hill starts of the present application with the prior art;
FIG. 5 is a graph comparing engine torque and clutch load torque during hill starts of the present application and the prior art;
fig. 6 is a structural diagram of a hill start assist module provided in the present application.
Detailed Description
Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, the numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present application unless specifically stated otherwise.
The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the application, its application, or uses.
Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail, but are intended to be part of the specification where appropriate.
In all examples shown and discussed herein, any particular value should be construed as exemplary only and not as limiting. Thus, other examples of the exemplary embodiments may have different values.
The application provides a hill start method and system based on an automatic stepless gearbox and a vehicle, wherein a gearbox electronic control unit implements a hill start auxiliary method, the rotating speed of an engine is quickly increased under a smaller clutch load, the clutch load is increased after the engine reaches sufficient torque, so that the start performance and the maximum climbing gradient are improved, and the problem of difficult hill start is solved.
As shown in fig. 1, the hill start system based on the automatic continuously variable transmission provided by the present application includes an engine electronic control unit ECU, a vehicle body stabilizing system ESP, and a transmission electronic control unit TCU.
And the transmission electric control unit TCU is in signal connection with the engine electric control unit ECU and the vehicle body stabilizing system ESP through a CAN bus.
The engine electronic control unit ECU detects a brake signal, namely whether the brake is released or not. The ECU of the engine also detects an accelerator signal, namely the opening of the accelerator. And the engine electronic control unit ECU sends a brake signal and an accelerator signal to the transmission electronic control unit TCU.
The body stabilization system ESP detects the ramp signal. As an example, the vehicle body stabilization system ESP sends a switch ramp signal to the transmission electronic control unit TCU via vehicle control unit local area network communication (CAN bus), so that the transmission electronic control unit TCU CAN directly identify whether the vehicle is on a ramp. As another embodiment, the vehicle body stabilizing system ESP sends a gravity acceleration signal to the transmission electronic control unit TCU through the CAN bus, and the internal logic of the transmission electronic control unit TCU calculates and determines whether the vehicle is on a slope.
The transmission electronic control unit TCU itself recognizes the gear signal.
The transmission electronic control unit TCU comprises a hill start assisting module used for assisting a vehicle in hill start.
Based on the hill start system, the hill start method based on the automatic stepless gearbox is executed by the gearbox electronic control unit TCU. It should be noted that the rotation speed control logic in hill start of the present application is independent of the shift line control logic of the transmission electronic control unit TCU.
As shown in fig. 2, the hill start method includes:
s210: and judging whether the vehicle is in a hill starting state or not. If yes, go to S220; otherwise, execution continues with S210.
Specifically, the transmission electronic control unit TCU receives a brake signal of the engine electronic control unit ECU, a ramp signal of the vehicle body stabilization system ESP, a vehicle speed signal of the vehicle electronic stabilization control system ESC, and a gear signal detected by itself. And if the vehicle is on a slope, the brake of the vehicle is in a release state, the vehicle speed is less than a second threshold value (for example, 2km/h or 1 km/h) and the current gear of the vehicle is a forward gear, determining that the vehicle is in a hill-start state. S220: and executing a hill start assisting method based on the gearbox electronic control unit.
Specifically, as shown in fig. 3, the hill start assisting method based on the transmission electronic control unit comprises the following steps:
s310: and receiving a current accelerator opening signal, and determining a first target rotating speed of the engine according to the current accelerator opening signal.
Specifically, the transmission electronic control unit TCU receives an accelerator opening signal of the engine electronic control unit ECU.
As an example, each throttle opening corresponds to a calibrated value of the first target speed.
S320: and after the clutch reaches the joint point, controlling the rotation speed of the engine to rapidly rise, controlling the load of the clutch to be below a first threshold value, and receiving the rotation speed information of the engine.
Specifically, the transmission electronic control unit TCU controls the load of the clutch and the rotational speed of the engine through the opening degree of the accelerator. The rotation speed and the clutch load are controlled based on the opening degree of the accelerator of the vehicle, the operability is flexible, and the maximum climbing capacity of the vehicle can be improved by adopting the accelerator at 100%.
As an embodiment, in the present application, each accelerator opening corresponds to a calibration value of an oil filling rate of a clutch, and a clutch load is calculated by a transmission electronic control unit TCU according to a first target rotation speed and the oil filling rate corresponding to the accelerator opening. Thus, each accelerator opening corresponds to a clutch load value.
The starting characteristic of the manual gear shifting gearbox MT of the engine is simulated, namely the higher the engine speed is before the engine reaches the rated rotating speed and the higher the torque is, the rotating speed of the engine is quickly increased, and the engine can reach a larger torque point. However, while the hill start assist control main body of the MT is the engine electronic control unit ECU, the hill start assist control main body of the present application is the transmission electronic control unit TCU.
S330: it is determined whether the rotational speed of the engine has increased to a first target rotational speed. If yes, go to S340; otherwise, return to S320.
S340: the load of the clutch is controlled to increase, the rotating speed of the engine is reduced at the same time, the vehicle starts climbing a slope, and the rotating speed information of the engine is received.
S350: it is determined whether the rotational speed of the engine has dropped to a second target rotational speed. If yes, executing S360; otherwise, return to S340.
Wherein the first target rotational speed is greater than the second target rotational speed.
As an embodiment, the second target rotation speed is a calibrated value.
S360: and controlling the load of the clutch to stop increasing to finish hill starting.
As shown in fig. 4 and 5, phase 1, which is an idling phase, i.e., before the clutch reaches the engagement point, the engine speed, the engine torque, and the clutch load in the present application are the same as those in the prior art.
In the prior art, at stages 2 and 3, the torque of the engine is built up and the clutch load is gradually increased while the engine speed and torque are slowly increased to a speed and torque corresponding to the second target speed. In this process, since the clutch load is large, the rotation speed and torque of the engine are difficult to increase, and the rotation speed and torque corresponding to the second target rotation speed are increased at maximum, so that the load torque of the clutch is small, resulting in difficulty in starting.
In phase 2, in the present application, as the accelerator opening increases, the torque of the engine builds up, the rotational speed of the engine rapidly increases while the load of the clutch is maintained at a low point. At this stage, since the load of the clutch is small, the difficulty of increasing the rotational speed of the engine is small, and the final first target rotational speed and the torque corresponding to the first target rotational speed are larger than the rotational speed and the torque corresponding to the second target rotational speed, and the first target rotational speed is used as a trigger condition for the load of the clutch to change. At phase 3, under the condition of larger engine torque, the clutch load is gradually increased, so that the clutch load obtains larger combined power, the load torque of the clutch is rapidly increased, and at the moment, the vehicle obtains sufficient torque and begins to climb the slope (namely, the vehicle speed is greater than 0). Meanwhile, as the load of the clutch rapidly increases, the rotational speed of the engine decreases. When the engine speed drops to the second target speed, the clutch load stops increasing, reaching a steady state, as shown in stage 4.
Therefore, in the application, the whole starting process is to realize the staged control of the clutch load through the higher first target rotating speed and the lower second target rotating speed, so that the control of the rotating speed of the engine is realized, and the stable starting of the vehicle is realized. As shown in fig. 4, the hill start assisting method of the present application enables the vehicle to start climbing at an earlier time than that in the prior art, and the vehicle speed of the present application is greater than that in the prior art after the clutch load reaches the steady state, so that the hill start assisting method of the present application reduces the difficulty of hill start and increases the hill start speed.
Preferably, in the hill start process, the transmission electronic control unit TCU calculates the corresponding target rotation speed in real time according to the change of the accelerator opening degree until the accelerator opening degree is stable, and uses the target rotation speed corresponding to the stabilized accelerator opening degree as the first target rotation speed, which is beneficial to smooth start of the vehicle.
Based on the hill start method, the transmission electronic control unit TCU comprises a hill start auxiliary module. As shown in FIG. 6, the hill start assist module includes a first target speed determination module 610, a speed control module 620, an engine speed receiving module 630, a determination module 640, and a load control module 650.
The first target rotation speed determination module 610 is configured to determine a first target rotation speed of the engine according to an accelerator opening degree signal sent by an engine electronic control unit.
The speed control module 620 is used for controlling the speed of the engine to increase before the speed of the engine increases to a first target speed and controlling the speed of the engine to decrease after the speed of the engine increases to the first target speed.
As one example, the speed control module 620 controls the load of the clutch and the speed of the engine via throttle opening.
The engine speed receiving module 630 is used for receiving the speed information sent by the engine electronic control unit.
The determination module 640 is used for determining whether the rotation speed of the engine is increased to a first target rotation speed and whether the rotation speed of the engine is decreased to a second target rotation speed.
The load control module 650 is configured to control a load of the clutch below a first threshold after the clutch reaches the engagement point and before the engine speed increases to a first target speed; the load control device is also used for controlling the load of the clutch to increase after the rotating speed of the engine rises to the first target rotating speed; and when the rotating speed of the engine is reduced to a second target rotating speed, the load of the clutch is controlled to stop increasing, and hill starting is completed.
Preferably, the transmission electronic control unit TCU further comprises a hill start assist function switch. And under the state that the hill start assisting function switch is turned on, the hill start assisting module can work. That is, the hill start assist method based on the transmission electronic control unit is executed when the hill start assist function switch is turned on and the vehicle is in the hill start state.
Preferably, the body stabilisation system further comprises an uphill assist module HAC, the main function of which is to prevent the vehicle from rolling backwards. In a hill starting state, the hill-climbing assisting module HAC and the hill-climbing assisting module work simultaneously, namely, on one hand, the vehicle is ensured not to slide backwards during hill starting, on the other hand, the vehicle is driven to perform hill starting through larger starting torque, and the hill starting effect is better.
Based on the hill start system and the hill start method, the application also provides a vehicle based on the automatic continuously variable transmission, the vehicle comprises the hill start system, and the hill start method is executed.
According to the method, on the basis of not changing a power assembly of the whole vehicle and not reducing the weight of the vehicle, different working conditions of a ramp and a non-ramp are distinguished through optimization of a gearbox control strategy, torque maximization output of the vehicle on the ramp is achieved, and the climbing performance of the vehicle is improved; meanwhile, NVH and driving comfort of the vehicle when too large torque is not needed during non-hill starting are guaranteed.
Although some specific embodiments of the present application have been described in detail by way of example, it should be understood by those skilled in the art that the above examples are for illustrative purposes only and are not intended to limit the scope of the present application. It will be appreciated by those skilled in the art that modifications can be made to the above embodiments without departing from the scope and spirit of the present application. The scope of the application is defined by the appended claims.
Claims (10)
1. A hill starting method based on an automatic stepless gearbox is characterized by comprising the following steps:
judging whether the vehicle is in a hill starting state or not;
if yes, executing a hill starting auxiliary method based on a gearbox electronic control unit, wherein the hill starting auxiliary method comprises the following steps:
receiving a current accelerator opening signal, and determining a first target rotating speed of an engine according to the current accelerator opening signal;
after the clutch reaches a joint point, controlling the rotating speed of the engine to rise, controlling the load of the clutch to be below a first threshold value, and receiving the rotating speed information of the engine;
if the rotating speed of the engine is increased to the first target rotating speed, controlling the load of the clutch to be increased, and simultaneously, reducing the rotating speed of the engine to enable the vehicle to start climbing a slope;
when the rotating speed of the engine is reduced to a second target rotating speed, controlling the load of the clutch to stop increasing, and finishing hill starting;
wherein the first target rotational speed is greater than the second target rotational speed.
2. The hill start method based on an automatic continuously variable transmission as claimed in claim 1, wherein said transmission electronic control unit controls the load of said clutch and the revolution speed of said engine by the opening degree of an accelerator.
3. The hill start method based on the automatic continuously variable transmission as claimed in claim 1, further comprising identifying whether a hill start assist function switch based on a transmission electronic control unit is turned on;
and if the vehicle is started and the vehicle is in a hill start state, executing the hill start assisting method based on the gearbox electronic control unit.
4. The method of claim 1 wherein the vehicle is in a hill start condition if the vehicle is on a hill, the vehicle's brakes are released, the vehicle speed is less than a second threshold, and the vehicle's current gear is forward.
5. The hill start method based on an automatic continuously variable transmission according to claim 3, wherein the hill start assist method based on the transmission electronic control unit is executed simultaneously with the hill start assist method based on the vehicle body stabilization system.
6. A hill start system based on an automatic stepless gearbox is characterized by comprising an engine electric control unit, a vehicle body stabilizing system and a gearbox electric control unit;
the transmission case electric control unit is in signal connection with the engine electric control unit and the vehicle body stabilizing system through a CAN bus;
the gearbox electronic control unit judges whether the vehicle is in a hill starting state or not through a brake signal sent by the engine electronic control unit, a ramp signal sent by the vehicle body stabilizing system and a gear signal recognized by the gearbox electronic control unit;
the electronic control unit of the gearbox comprises a hill start assisting module, wherein the hill start assisting module comprises a first target rotating speed determining module, a rotating speed control module, an engine rotating speed receiving module, a judging module and a load control module;
the first target rotating speed determining module is used for determining a first target rotating speed of the engine according to an accelerator opening degree signal sent by the engine electronic control unit;
the rotating speed control module is used for controlling the rotating speed of the engine to rise before the rotating speed of the engine rises to the first target rotating speed and is also used for controlling the rotating speed of the engine to fall after the rotating speed of the engine rises to the first target rotating speed;
the engine rotating speed receiving module is used for receiving rotating speed information sent by the engine electronic control unit;
the judging module is used for judging whether the rotating speed of the engine is increased to the first target rotating speed or not and whether the rotating speed of the engine is reduced to a second target rotating speed or not;
the load control module is used for controlling the load of the clutch to be below a first threshold value after the clutch reaches a junction point and before the rotating speed of the engine is increased to the first target rotating speed; further for controlling the load of the clutch to increase after the rotational speed of the engine has risen to the first target rotational speed; the clutch is also used for controlling the load of the clutch to stop increasing when the rotating speed of the engine is reduced to the second target rotating speed, and hill starting is completed;
wherein the first target rotational speed is greater than the second target rotational speed.
7. The automated continuously variable transmission-based hill start system of claim 6 wherein the speed control module controls a load of a clutch and a speed of the engine through throttle opening.
8. The automated continuously variable transmission-based hill start system of claim 6 wherein the transmission electronic control unit further comprises a hill start assist function switch.
9. An automated continuously variable transmission-based hill start system as claimed in claim 8, wherein the body stabilising system further comprises an uphill assist module for operating simultaneously with the hill start assist module in a hill start condition.
10. An automated continuously variable transmission based vehicle for performing a hill start method based on an automated continuously variable transmission according to any of claims 1-5.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211199991.1A CN115431982A (en) | 2022-09-29 | 2022-09-29 | Hill starting method and system based on automatic continuously variable transmission and vehicle |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211199991.1A CN115431982A (en) | 2022-09-29 | 2022-09-29 | Hill starting method and system based on automatic continuously variable transmission and vehicle |
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| Publication Number | Publication Date |
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| CN115431982A true CN115431982A (en) | 2022-12-06 |
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| CN202211199991.1A Pending CN115431982A (en) | 2022-09-29 | 2022-09-29 | Hill starting method and system based on automatic continuously variable transmission and vehicle |
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| Country | Link |
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| CN (1) | CN115431982A (en) |
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