[go: up one dir, main page]

CN116164100A - Speed ratio control method and device for continuously variable transmission, storage medium and electronic equipment - Google Patents

Speed ratio control method and device for continuously variable transmission, storage medium and electronic equipment Download PDF

Info

Publication number
CN116164100A
CN116164100A CN202111415334.1A CN202111415334A CN116164100A CN 116164100 A CN116164100 A CN 116164100A CN 202111415334 A CN202111415334 A CN 202111415334A CN 116164100 A CN116164100 A CN 116164100A
Authority
CN
China
Prior art keywords
speed ratio
continuously variable
variable transmission
change rate
target
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202111415334.1A
Other languages
Chinese (zh)
Inventor
刘耀锋
杨智雄
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
SAIC Motor Corp Ltd
Shanghai Automotive Industry Corp Group
Original Assignee
SAIC Motor Corp Ltd
Shanghai Automotive Industry Corp Group
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by SAIC Motor Corp Ltd, Shanghai Automotive Industry Corp Group filed Critical SAIC Motor Corp Ltd
Priority to CN202111415334.1A priority Critical patent/CN116164100A/en
Publication of CN116164100A publication Critical patent/CN116164100A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
    • F16H61/66—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing specially adapted for continuously variable gearings
    • F16H61/662—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing specially adapted for continuously variable gearings with endless flexible members
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H9/00—Gearings for conveying rotary motion with variable gear ratio, or for reversing rotary motion, by endless flexible members
    • F16H9/02—Gearings for conveying rotary motion with variable gear ratio, or for reversing rotary motion, by endless flexible members without members having orbital motion
    • F16H9/04—Gearings for conveying rotary motion with variable gear ratio, or for reversing rotary motion, by endless flexible members without members having orbital motion using belts, V-belts, or ropes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
    • F16H61/66—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing specially adapted for continuously variable gearings
    • F16H61/662—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing specially adapted for continuously variable gearings with endless flexible members
    • F16H2061/66204—Control for modifying the ratio control characteristic

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Control Of Transmission Device (AREA)

Abstract

The invention provides a speed ratio control method and device of a continuously variable transmission, a storage medium and electronic equipment, wherein the method comprises the following steps: acquiring the current target rotating speed of the continuously variable transmission, and determining whether the continuously variable transmission meets a speed ratio control condition based on the target rotating speed; when satisfied, determining a current target speed ratio of the continuously variable transmission; determining a target speed ratio change rate of a target speed ratio, periodically adjusting the change rate of the target speed ratio change rate based on a speed ratio limiting strategy, and adjusting the speed ratio of the continuously variable transmission according to the limited speed ratio change rate obtained after adjustment until the speed ratio of the continuously variable transmission reaches the target speed ratio. The change rate of the target speed ratio change rate is periodically adjusted according to the speed ratio limiting strategy, and the speed ratio of the continuously variable transmission is adjusted according to the adjusted limited speed ratio change rate, so that the speed ratio of the continuously variable transmission can be smoothly switched to the target speed ratio, flow fluctuation of a system can be effectively slowed down, the aging condition of the CVT is delayed, and the service life is prolonged.

Description

Speed ratio control method and device for continuously variable transmission, storage medium and electronic equipment
Technical Field
The present invention relates to the field of engine technologies, and in particular, to a speed ratio control method and apparatus for a continuously variable transmission, a storage medium, and an electronic device.
Background
The stepless speed changer is used as a novel power shift speed changer, has the advantages of comfortable driving, low emission, good fuel economy, stepless gear shift realization and the like, and has good market prospect. In particular, a continuously variable transmission (Continuously Variable Transmission, CVT) dynamically and optimally matches the running resistance of a vehicle with the load of an engine by continuously changing the speed ratio, and the engine is always kept operating in a high-efficiency region, so that the potential of the engine is brought into an optimal state according to the operation intention of a driver.
When the traditional control mode controls the speed ratio of the stepless speed change, the speed ratio of the CVT is suddenly changed, and when the speed ratio of the CVT is suddenly changed, sudden flow fluctuation easily occurs, the aging of the CVT is easily aggravated, and the service life of the CVT is reduced.
Disclosure of Invention
In view of this, the present invention provides a speed ratio control method and apparatus for a continuously variable transmission, a storage medium, and an electronic device, which can smoothly adjust the speed ratio of the continuously variable transmission to a target speed ratio by adjusting the change rate of the target speed ratio, reduce the fluctuation of the flow, delay the aging of the CVT, and prolong the service life of the CVT.
In order to achieve the above object, the embodiment of the present invention provides the following technical solutions:
the first aspect of the application discloses a speed ratio control method of a continuously variable transmission, comprising the following steps:
acquiring the current target rotating speed of the continuously variable transmission, and determining whether the continuously variable transmission meets a preset speed ratio control condition based on the target rotating speed;
when the continuously variable transmission is determined to meet a preset speed ratio control condition, determining a current target speed ratio of the continuously variable transmission;
determining a target speed ratio change rate of the target speed ratio, periodically adjusting the change rate of the target speed ratio change rate based on a preset speed ratio limiting strategy, and adjusting the speed ratio of the continuously variable transmission according to the limited speed ratio change rate obtained after adjustment until the speed ratio of the continuously variable transmission reaches the target speed ratio.
The method, optionally, includes obtaining a current target rotation speed of the continuously variable transmission;
acquiring the current accelerator opening and the current speed of a vehicle to which the continuously variable transmission belongs;
and processing the accelerator opening of the vehicle and the vehicle speed to obtain the target rotating speed of the continuously variable transmission.
In the above method, optionally, the determining whether the continuously variable transmission meets a preset speed ratio control condition based on the target rotation speed includes:
Acquiring the current input shaft rotating speed of the continuously variable transmission;
determining a rotational speed difference between the input shaft rotational speed and the target rotational speed;
determining whether the rotational speed difference is greater than or equal to a preset difference;
and when the rotating speed difference value is larger than or equal to the preset difference value, determining that the continuously variable transmission meets a preset speed ratio control condition.
The above method, optionally, the determining the current target speed ratio of the continuously variable transmission includes:
and processing the target rotating speed and the input shaft rotating speed to obtain the current target speed ratio of the continuously variable transmission.
According to the method, optionally, the step of periodically adjusting the change rate of the target speed ratio change rate based on a preset speed ratio limiting strategy, and adjusting the speed ratio of the continuously variable transmission according to the limited speed ratio change rate obtained after the adjustment until the speed ratio of the continuously variable transmission reaches the target speed ratio, includes:
determining an initial control period, and determining the initial control period as a first control period;
acquiring each first control parameter corresponding to the first control period;
obtaining a first limiting range of the change rate of the target speed ratio change rate corresponding to the first control period based on each first control parameter;
Determining a first limiting parameter corresponding to the first control period, and determining a first limiting value of a change rate of a target speed ratio change rate corresponding to the first control period based on the first limiting parameter and the first limiting range;
determining a first limiting speed ratio change rate corresponding to the first limiting value, and controlling the continuously variable transmission to output a first speed ratio corresponding to the first control period based on the first limiting speed ratio change rate;
judging whether the first speed ratio is equal to the target speed ratio;
if the first speed ratio is not equal to the target speed ratio, determining whether a difference between the first limiting speed ratio change rate and the target speed ratio change rate is zero;
if the difference between the first limiting speed ratio change rate and the target speed ratio change rate is not zero, determining a next control period, taking the next control period as a new first control period, and returning to execute the step of acquiring each first control parameter corresponding to the first control period;
if the difference between the first limiting speed ratio change rate and the target speed ratio change rate is zero, determining whether the difference between the first speed ratio and the target speed ratio is greater than a preset first threshold;
If the difference between the first speed ratio and the target speed ratio is greater than the first threshold, determining a next control period, and determining the next control period as a second control period;
controlling the continuously variable transmission to output a second speed ratio corresponding to the second control period based on the target speed ratio change rate;
judging whether the difference between the second speed ratio and the target speed ratio is larger than the first threshold value;
if the difference between the second speed ratio and the target speed ratio is greater than the first threshold, determining a next control period, determining the next control period as a new second control period, and returning to execute the step of controlling the continuously variable transmission to output a second speed ratio corresponding to the second control period based on the target speed ratio change rate;
if the difference between the second speed ratio and the target speed ratio is not greater than the first threshold, determining a next control period, and determining the next control period as a third control period;
acquiring each second control parameter corresponding to the third control period;
determining a second limit range of a change rate of a target speed ratio change rate corresponding to the third control period based on each of the second control parameters;
Determining a third limiting parameter corresponding to the third control period, and determining a second limiting value of a change rate of a target speed ratio change rate corresponding to the third control period based on the third limiting parameter and the second limiting range;
determining a third limiting speed ratio change rate corresponding to the third limiting value, and controlling the continuously variable transmission to output a third speed ratio corresponding to the third control period based on the third limiting speed ratio change rate;
judging whether the third speed ratio is equal to the target speed ratio;
if the third speed ratio is not equal to the target speed ratio, determining a next control period, determining the next control period as a new third control period, and returning to execute the operation of acquiring each second control parameter corresponding to the third control period;
and if the third speed ratio and the like are equal to the target speed ratio, completing the control of the speed ratio of the continuously variable transmission.
A second aspect of the present application discloses a speed ratio control apparatus of a continuously variable transmission, comprising:
an acquisition unit, configured to acquire a current target rotational speed of a continuously variable transmission, and determine whether the continuously variable transmission meets a preset speed ratio control condition based on the target rotational speed;
A determining unit configured to determine a current target speed ratio of the continuously variable transmission when it is determined that the continuously variable transmission satisfies a preset speed ratio control condition;
the adjusting unit is used for determining a target speed ratio change rate of the target speed ratio, periodically adjusting the change rate of the target speed ratio change rate based on a preset speed ratio limiting strategy, and adjusting the speed ratio of the continuously variable transmission according to the limited speed ratio change rate obtained after adjustment until the speed ratio of the continuously variable transmission reaches the target speed ratio.
The above device, optionally, the acquiring unit includes:
a first obtaining subunit, configured to obtain a current accelerator opening and a current vehicle speed of a vehicle to which the continuously variable transmission belongs;
and the first processing subunit is used for processing the accelerator opening of the vehicle and the vehicle speed to obtain the target rotating speed of the continuously variable transmission.
The above device, optionally, the acquiring unit includes:
the second acquisition subunit is used for acquiring the current input shaft rotating speed of the continuously variable transmission;
a first determination subunit configured to determine a rotation speed difference between the input shaft rotation speed and the target rotation speed;
A second determining subunit, configured to determine whether the rotational speed difference is greater than or equal to a preset difference;
and the third determination subunit is used for determining that the continuously variable transmission meets a preset speed ratio control condition when the rotating speed difference value is larger than or equal to the preset difference value.
The above apparatus, optionally, the determining unit includes:
and the second processing subunit is used for processing the target rotating speed and the input shaft rotating speed to obtain the current target speed ratio of the continuously variable transmission.
The above device, optionally, the adjusting unit includes:
a fourth determination subunit configured to determine an initial control period, and determine the initial control period as a first control period;
a third obtaining subunit, configured to obtain each first control parameter corresponding to the first control period;
a fourth obtaining subunit, configured to obtain, based on each of the first control parameters, a first limit range of a change rate of a target speed ratio change rate corresponding to the first control period;
a fifth determination subunit configured to determine a first limiting parameter corresponding to the first control period, and determine a first limiting value of a change rate of a target speed ratio change rate corresponding to the first control period based on the first limiting parameter and the first limiting range;
A first control subunit configured to determine a first limiting speed ratio change rate corresponding to the first limiting value, and control the continuously variable transmission to output a first speed ratio corresponding to the first control period based on the first limiting speed ratio change rate;
a first judging subunit configured to judge whether the first speed ratio is equal to the target speed ratio;
a sixth determining subunit configured to determine whether a difference between the first limited speed ratio change rate and the target speed ratio change rate is zero if the first speed ratio is not equal to the target speed ratio;
a seventh determining subunit, configured to determine a next control period if it is determined that the difference between the first limiting speed ratio change rate and the target speed ratio change rate is not zero, take the next control period as a new first control period, and return to execute the step of acquiring each first control parameter corresponding to the first control period;
an eighth determining subunit, configured to determine, if it is determined that the difference between the first limited speed ratio change rate and the target speed ratio change rate is zero, whether the difference between the first speed ratio and the target speed ratio is greater than a preset first threshold;
A ninth determining subunit, configured to determine a next control period if a difference between the first speed ratio and the target speed ratio is greater than the first threshold, and determine the next control period as a second control period;
a second control subunit configured to control the continuously variable transmission to output a second speed ratio corresponding to the second control period based on the target speed ratio change rate;
a second judging subunit configured to judge whether a difference between the second speed ratio and the target speed ratio is greater than the first threshold;
a tenth determination subunit configured to determine a next control period if a difference between the second speed ratio and the target speed ratio is greater than the first threshold, determine the next control period as a new second control period, and return to perform the step of controlling the continuously variable transmission to output a second speed ratio corresponding to the second control period based on the target speed ratio change rate;
an eleventh determination subunit configured to determine a next control period if a difference between the second speed ratio and the target speed ratio is not greater than the first threshold, and determine the next control period as a third control period;
A fifth obtaining subunit, configured to obtain each second control parameter corresponding to the third control period;
a twelfth determination subunit configured to determine, based on each of the second control parameters, a second limit range of a change rate of a target speed ratio change rate corresponding to the third control period;
a thirteenth determination subunit configured to determine a third limiting parameter corresponding to the third control period, and determine a second limiting value of a change rate of a target speed ratio change rate corresponding to the third control period based on the third limiting parameter and the second limiting range;
a third control subunit configured to determine a third limiting speed ratio change rate corresponding to the third limiting value, and control the continuously variable transmission to output a third speed ratio corresponding to the third control period based on the third limiting speed ratio change rate;
a third judging subunit configured to judge whether the third speed ratio is equal to the target speed ratio;
a fourteenth determination subunit configured to determine a next control period if the third speed ratio is not equal to the target speed ratio, determine the next control period as a new third control period, and return to perform the operation of acquiring each second control parameter corresponding to the third control period;
And the completion subunit is used for completing the control of the speed ratio of the continuously variable transmission if the third speed ratio and the like are equal to the target speed ratio.
A third aspect of the present application discloses a storage medium including stored instructions, wherein the instructions, when executed, control an apparatus in which the storage medium is located to perform a speed ratio control method of a continuously variable transmission as described above.
A fourth aspect of the present application discloses an electronic device comprising a memory, and one or more instructions, wherein the one or more instructions are stored in the memory and configured to be executed by the one or more processors to perform a speed ratio control method of a continuously variable transmission as described above.
Compared with the prior art, the invention has the following advantages:
the invention provides a speed ratio control method and device of a continuously variable transmission, a storage medium and electronic equipment, wherein the method comprises the following steps: acquiring the current target rotating speed of the continuously variable transmission, and determining whether the continuously variable transmission meets a preset speed ratio control condition based on the target rotating speed; when the continuously variable transmission is determined to meet the preset speed ratio control condition, determining the current target speed ratio of the continuously variable transmission; determining a target speed ratio change rate of a target speed ratio, periodically adjusting the change rate of the target speed ratio change rate based on a preset speed ratio limiting strategy, and adjusting the speed ratio of the continuously variable transmission according to the limited speed ratio change rate obtained after adjustment until the speed ratio of the continuously variable transmission reaches the target speed ratio. When the continuously variable transmission meets the speed ratio control condition, the change rate of the target speed ratio change rate is periodically adjusted according to a preset speed ratio limiting strategy, and the speed ratio of the continuously variable transmission is adjusted according to the adjusted limited speed ratio change rate, so that the speed ratio of the continuously variable transmission can be smoothly switched to the target speed ratio, thereby effectively slowing down the flow fluctuation of a system, delaying the aging condition of the CVT and prolonging the service life of the CVT.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only embodiments of the present invention, and that other drawings can be obtained according to the provided drawings without inventive effort for a person skilled in the art.
FIG. 1 is an exemplary diagram of a CVT shift;
FIG. 2 is a schematic diagram of a CVT master slave cylinder;
FIG. 3 is a graph illustrating various indices of a vehicle when a speed ratio of a continuously variable transmission is controlled using a conventional manner;
FIG. 4 is a flow chart illustrating a method for controlling a speed ratio of a continuously variable transmission according to an embodiment of the present invention;
FIG. 5 is a flowchart of a method of controlling a speed ratio of a continuously variable transmission according to an embodiment of the present invention;
FIG. 6 is a flowchart of another method for controlling a speed ratio of a continuously variable transmission according to an embodiment of the present invention;
FIG. 7 is a graph illustrating various indicators of a vehicle after the present invention is applied according to an embodiment of the present invention;
FIG. 8 is an exemplary plot of various ratio curves provided by an embodiment of the present invention;
FIG. 9 is a schematic diagram of a speed ratio control apparatus for a continuously variable transmission according to an embodiment of the present invention;
fig. 10 is a schematic structural diagram of an electronic device according to an embodiment of the present invention.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
In this application, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
The stepless speed changer is used as a novel power shift speed changer, has the advantages of comfortable driving, low emission, good fuel economy, stepless gear shift realization and the like, and has good market prospect. In particular, a continuously variable transmission (Continuously Variable Transmission, CVT) dynamically and optimally matches the running resistance of a vehicle with the load of an engine by continuously changing the speed ratio, and the engine is always kept operating in a high-efficiency region, so that the potential of the engine is brought into an optimal state according to the operation intention of a driver.
The traditional stepless speed changer control method comprises the following steps: the engine target rotation speed is determined according to the accelerator opening degree and the vehicle speed, and the CVT target speed ratio at this time is calculated for the CVT according to the engine target rotation speed, as shown in fig. 1, which is a CVT shift map when the speed ratio of the continuously variable transmission is controlled using the conventional method. Referring to fig. 2, a schematic diagram of a CVT master-slave cylinder, where the CVT master-slave lever conventionally operates is as follows:
(1) The slave cylinder determines the pressure of the slave cylinder according to the transmission torque of the steel belt and the actual speed ratio, so as to ensure that the steel belt can safely transmit the torque, namely the slave cylinder is responsible for clamping force.
(2) The driving cylinder determines the pressure of the driving cylinder according to the target speed ratio and the oil pressure of the driven cylinder so as to ensure that the actual speed ratio follows the target speed ratio, namely the driving cylinder is responsible for speed ratio control.
When the accelerator of the driver is increased, the target rotation speed and the target speed ratio of the input shaft are also increased, as shown in fig. 3, which is a curve example of each index of the vehicle when the speed ratio of the continuously variable transmission is controlled by using the conventional mode, it can be known from the graph that the speed ratio is changed from the near-steady-speed condition to the fast-speed condition, at this moment, the flow of the whole system is rapidly increased, the sliding valve of the main driven oil cylinder is required to be adjusted to the new large-flow balance state from the original small-flow balance state, and a certain time is required for adjustment, so that the actual hydraulic pit (hydraulic pit) is caused, the clamping force is insufficient, and the risk of steel belt slipping is brought. When the actual rotation speed reaches the target rotation speed, the target speed ratio is changed from quick speed change to slow speed change, at the moment, the flow of the whole system is rapidly reduced, the sliding valve of the main driving oil cylinder is required to be adjusted to a new small flow balance state from an original large flow balance state, and a certain time is required for adjustment, so that the actual hydraulic overshoot (hydraulic bulge) is caused, the excessive clamping force is caused, the lifting of the steel belt stress is brought, the fatigue and aging of the steel belt are aggravated, and the service life of the continuously variable transmission is shortened.
The invention aims to provide a brand-new speed ratio control method, which solves the problems of aggravated aging of CVT and shortened service life caused by hydraulic pit dropping and hydraulic overshoot due to response delay of a hydraulic system when the speed ratio change rate of the CVT changes sharply.
The invention provides a speed ratio control method of a continuously variable transmission, which can be applied to a control system of a vehicle, wherein the control system consists of a computer terminal or a computing type distribution device, such as a microcomputer, a central processor and other intelligent devices with data processing functions.
Referring to fig. 4, a method flow of a speed ratio control method of a continuously variable transmission according to an embodiment of the present invention is specifically described below:
s101, acquiring the current target rotating speed of the continuously variable transmission, and determining whether the continuously variable transmission meets a preset speed ratio control condition based on the target rotating speed.
Preferably, the continuously variable transmission is a steel belt type and chain type continuously variable transmission, and the specific process of obtaining the current target rotation speed of the continuously variable transmission is as follows:
acquiring the current accelerator opening and the current speed of a vehicle to which the continuously variable transmission belongs; the current accelerator opening and the current vehicle speed of the vehicle can be obtained by special sensors.
Processing the accelerator opening of the vehicle and the vehicle speed to obtain a target rotating speed of the continuously variable transmission; the target rotational speed is the rotational speed that should be achieved in practice in the continuously variable transmission.
The current target rotational speed of the continuously variable transmission can be obtained by processing the current accelerator opening and the vehicle speed of the vehicle to which the continuously variable transmission belongs.
Further, the current target rotational speed of the continuously variable transmission is determined in real time, and preferably, the current target rotational speed of the continuously variable transmission is changed when the accelerator opening of the vehicle is changed.
Referring to fig. 5, a flowchart of a method for determining whether a continuously variable transmission currently satisfies a preset speed ratio control condition is described in detail as follows:
s201, acquiring the current input shaft rotation speed of the continuously variable transmission.
The current input shaft rotational speed of the continuously variable transmission may be obtained by a sensor for detecting the input shaft rotational speed of the continuously variable transmission. The current input shaft speed of the continuously variable transmission is the current actual speed of the continuously variable transmission.
S202, determining a rotation speed difference value between the rotation speed of the input shaft and the target rotation speed.
The rotational speed difference is an absolute value, i.e. the rotational speed difference is a positive number; in other words, the rotational speed difference is the absolute value of the difference between the output shaft and the target rotational speed.
S203, determining whether the rotation speed difference value is larger than or equal to a preset difference value; when it is determined that the rotation speed difference is greater than or equal to the preset difference, S204 is performed; when it is determined that the rotational speed difference is not greater than or equal to the preset difference, S205 is performed.
Comparing the rotating speed difference value with a preset difference value to determine whether the rotating speed difference value is larger than or equal to the preset difference value.
The preset difference is a preset value, which can be set according to actual requirements, and is usually a reasonable value obtained by analyzing a large amount of data, and the value is a positive number.
S204, determining that the continuously variable transmission meets a preset speed ratio control condition.
S205, determining that the continuously variable transmission does not meet a preset speed ratio control condition.
Further, when it is determined that the continuously variable transmission meets the preset speed ratio control condition, the next flow may be entered, and when it is determined that the continuously variable transmission does not meet the preset speed ratio control condition, a new target rotational speed of the continuously variable transmission may be obtained, and based on the new target rotational speed, it is determined again whether the continuously variable transmission meets the preset speed ratio control condition.
When it is determined that the continuously variable transmission satisfies the preset speed ratio control condition, it may be determined that the speed ratio of the continuously variable transmission is stepped, and it is necessary to control the actual speed ratio of the continuously variable transmission to gradually switch to the target speed ratio.
S102, when the continuously variable transmission is determined to meet a preset speed ratio control condition, determining the current target speed ratio of the continuously variable transmission.
When the target speed ratio of the continuously variable transmission is determined, the target speed ratio can be determined through the target speed and the input shaft speed, and the specific process can be that the target speed is divided by the input shaft speed, so that the current target speed ratio of the continuously variable transmission can be obtained.
S103, determining a target speed ratio change rate of the target speed ratio, periodically adjusting the change rate of the target speed ratio change rate based on a preset speed ratio limiting strategy, and adjusting the speed ratio of the continuously variable transmission according to the limited speed ratio change rate obtained after adjustment until the speed ratio of the continuously variable transmission reaches the target speed ratio.
In the method provided by the embodiment of the invention, the target change rate of the target speed ratio can be obtained by carrying out first-order derivation on the speed ratio.
After the target speed ratio change rate of the target speed ratio is obtained, the change rate of the target speed ratio change rate is required to be periodically adjusted based on a speed ratio limiting strategy and the response characteristic of the hydraulic system, a corresponding limiting speed ratio change rate can be obtained by adjusting the change rate of the target speed ratio change rate each time, the speed ratio of the continuously variable transmission is adjusted according to the limiting speed ratio change rate, so that the speed ratio corresponding to the limiting speed ratio change rate can be obtained, the speed ratio corresponding to the limiting speed ratio change rate is compared with the target speed ratio, and when the speed ratio corresponding to the limiting speed ratio change rate is consistent with the target speed ratio, the adjustment of the change rate of the target speed ratio change rate can be stopped, so that the speed ratio control of the continuously variable transmission is completed; and when the speed ratio corresponding to the limited speed ratio change rate is inconsistent with the target speed ratio, continuing to adjust the change rate of the target speed ratio change rate.
In the method provided by the embodiment of the invention, when the change rate of the target speed ratio is adjusted, the change rate of the target speed ratio can be obtained by carrying out second-order derivation on the speed ratio, and the speed ratio of the continuously variable transmission can be gradually and smoothly switched to the target speed ratio in a curve manner in the process of gradually adjusting the speed ratio of the continuously variable transmission to the target speed ratio, so that the smoothness of the speed ratio switching process is ensured, and the drivability of the whole vehicle is improved.
In the method provided by the embodiment of the invention, the current target rotating speed of the continuously variable transmission is obtained, and whether the continuously variable transmission meets the preset speed ratio control condition is determined based on the target rotating speed; when the continuously variable transmission is determined to meet the preset speed ratio control condition, determining the current target speed ratio of the continuously variable transmission; determining a target speed ratio change rate of a target speed ratio, periodically adjusting the change rate of the target speed ratio change rate based on a preset speed ratio limiting strategy, and adjusting the speed ratio of the continuously variable transmission according to the limited speed ratio change rate obtained after adjustment until the speed ratio of the continuously variable transmission reaches the target speed ratio. When the continuously variable transmission meets the speed ratio control condition, the change rate of the target speed ratio change rate is periodically adjusted according to a preset speed ratio limiting strategy, and the speed ratio of the continuously variable transmission is adjusted according to the adjusted limited speed ratio change rate, so that the speed ratio of the continuously variable transmission can be smoothly switched to the target speed ratio, thereby effectively slowing down the flow fluctuation of a system, delaying the aging condition of the CVT and prolonging the service life of the CVT.
In the method provided by the embodiment of the invention, the process of periodically adjusting the change rate of the target speed ratio change rate and controlling the speed ratio of the continuously variable transmission according to the limited speed ratio change rate obtained after adjustment until the speed ratio of the continuously variable transmission reaches the target speed ratio is described, and the specific flow is shown by referring to fig. 6, and the specific description is as follows:
s301, determining an initial control period, and determining the initial control period as a first control period.
When determining the initial control period, the initial control period may be determined according to a preset time step, specifically, if the time step is 0.01 second, the duration of the initial control period is 0.01 second.
The initial control period is the first period in which the change rate of the target speed ratio change rate is adjusted, and is also the first period in which the speed ratio of the continuously variable transmission is adjusted.
S302, acquiring each first control parameter corresponding to the first control period.
The first control parameters include, but are not limited to, oil temperature of the hydraulic system, speed ratio of the current actual output of the continuously variable transmission; further, the first control parameter may also include a current slave cylinder pressure, master cylinder pressure, etc. of the hydraulic system.
S303, obtaining a first limit range of the change rate of the target speed ratio change rate corresponding to the first control period based on each first control parameter.
And carrying out derivative operation based on each first control parameter to obtain a first limiting range of the change rate of the target speed ratio change rate corresponding to the first control period, wherein the first limiting range is a range in which the change rate of the target speed ratio change rate can be adjusted.
S304, determining a first limiting parameter corresponding to the first control period, and determining a first limiting value of the change rate of the target speed ratio change rate corresponding to the first control period based on the first limiting parameter and the first limiting range.
When the first control period is the initial control period, the first limiting parameter is null; when the first control period is not the initial control period, the first limiting parameter is a limiting value of the change rate of the target speed ratio change rate of the previous control period; the specific value of the determined first limit value is within the first limit range.
S305, determining a first limiting speed ratio change rate corresponding to the first limiting value, and controlling the continuously variable transmission to output a first speed ratio corresponding to a first control period based on the first limiting speed ratio change rate.
After the first limiting value is determined, a first limiting speed ratio change rate can be determined according to the first limiting value, and the continuously variable transmission is controlled to output a first speed ratio corresponding to a first control period according to the first limiting speed ratio change rate; the first speed ratio is a speed ratio which is output by the continuously variable transmission in a first control period according to a first limiting speed ratio change rate. The first speed ratio is the actual output speed ratio of the continuously variable transmission.
S306, judging whether the first speed ratio is equal to the target speed ratio; if it is determined that the first speed ratio is not equal to the target speed ratio, S307 is performed; if it is determined that the first speed ratio is equal to the target speed ratio, S321 is performed.
And comparing the first speed ratio with the target speed ratio, and judging whether the first speed ratio is equal to the target speed ratio.
S307, determining whether the difference between the first limiting speed ratio change rate and the target speed ratio change rate is zero; if it is determined that the difference between the first limiting speed ratio change rate and the target speed ratio change rate is not zero, then S308 is performed; if it is determined that the difference between the first limiting speed ratio change rate and the target speed ratio change rate is zero, S309 is performed.
S308, determining the next control period, taking the next control period as a new first control period, and returning to execute S302.
Based on a first control period, the process of adjusting the speed ratio of the continuously variable transmission is a first stage, and the stage can gradually adjust the change rate of the target speed ratio change rate, so that the speed ratio change rate of the continuously variable transmission can be in a curve form and smoothly transited to the target speed ratio change rate, the speed ratio of the continuously variable transmission can be adjusted in a curve, fluctuation of flow can be slowed down, hydraulic pressure is well tracked, aging of the CVT is delayed, and the service life of the CVT is prolonged.
S309, determining whether the difference between the first speed ratio and the target speed ratio is greater than a preset first threshold; if it is determined that the difference between the first speed ratio and the target speed ratio is greater than the first threshold, S310 is performed; if it is determined that the difference between the first speed ratio and the target speed ratio is not greater than the first threshold, S314 is performed.
S310, determining a next control period, and determining the next control period as a second control period.
When the next control period is determined as the second control period, it means that the speed ratio change rate of the continuously variable transmission enters a change phase of the constant speed, at which time the speed ratio of the continuously variable transmission output can be controlled directly according to the target speed ratio change.
S311, controlling the continuously variable transmission to output a second speed ratio corresponding to a second control period based on the target speed ratio change rate.
The process of adjusting the change rate of the target speed ratio change rate is a second stage in which the speed ratio of the continuously variable transmission is changed at a steady speed.
S312, judging whether the difference between the second speed ratio and the target speed ratio is larger than a first threshold value; if the difference between the second speed ratio and the target speed ratio is greater than the first threshold, S313 is performed; if the difference between the second speed ratio and the target speed ratio is not greater than the first threshold, S314 is performed.
S313, determining the next control period, and determining the next control period as a new second control period, and returning to S311.
S314, determining the next control period, and determining the next control period as the third control period.
When the next control period is determined as the third control period, a third stage of adjusting the speed ratio of the continuously variable transmission can be determined, and the speed ratio of the continuously variable transmission can be smoothly transited to the target speed ratio by adjusting the change rate of the target speed ratio in the third stage, so that flow fluctuation is effectively slowed down, the working performance of the CVT is provided, the aging of the CVT is delayed, and the service life of the CVT is prolonged.
When the next control period is determined as the third control period, the time for entering the third stage of adjusting the speed ratio of the continuously variable transmission has been determined, and when the time is determined, the speed ratio of the continuously variable transmission has not yet reached the target speed ratio.
S315, acquiring each second control parameter corresponding to the third control period.
The second control parameters include, but are not limited to, oil temperature, response time of the ratio slide valve, slave and master cylinder pressures, current output ratio of the continuously variable transmission, last cycle output ratio, and the like.
S316, determining a second limit range of the change rate of the target speed ratio change rate corresponding to the third control period based on each second control parameter.
A derivative operation is performed based on each of the second control parameters, whereby a second limit range of the change rate of the target speed ratio change rate corresponding to the third control period can be determined.
S317, determining a third limiting parameter corresponding to the third control period, and determining a second limiting value of the change rate of the target speed ratio change rate corresponding to the third control period based on the third limiting parameter and the second limiting range.
The third limiting parameter is a limiting value of a change rate of a speed ratio change rate of the continuously variable transmission of the previous control period, and a specific value of the second limiting value is within a second limiting range.
S318, determining a third limiting speed ratio change rate corresponding to the third limiting value, and controlling the continuously variable transmission to output a third speed ratio corresponding to a third control period based on the third limiting speed ratio change rate.
S319, judging whether the third speed ratio is equal to the target speed ratio; if it is determined that the third speed ratio is not equal to the target speed ratio, S320 is performed; if it is determined that the third speed ratio is equal to the target speed ratio, S321 is performed.
S320, determining the next control period as a new third control period, and returning to S315.
S321, the control of the speed ratio of the continuously variable transmission is completed.
According to the invention, by considering the characteristic of response delay of the hydraulic system, the change rate of the speed ratio change rate is adjusted, the abrupt change of the system flow is avoided, the normal tracking of the actual hydraulic pressure is ensured, the aging of the CVT is delayed, and the service life of the CVT is prolonged.
The invention divides the speed ratio change rate adjustment into three phases, the first phase is a phase of speed ratio switching from steady speed to rapid speed change, when the speed ratio change rate is adjusted in the phase, the influence characteristic of the oil temperature and the speed ratio on the response time of the slide valve is adjusted; the second phase is a phase of speed-ratio steady speed change, in which the value of the change rate of the speed-ratio change rate is 0, and in which the speed ratio of the continuously variable transmission can be adjusted according to the original speed-ratio change rate (i.e., the target speed-ratio change rate); the third phase is a phase of fast speed ratio switching to steady speed, before entering the phase, the time for entering the phase needs to be determined based on the second phase, and further, the time for entering the third phase is the end time of the second phase; after entering the third stage, the change rate of the speed ratio change rate can be adjusted according to the oil temperature and the influence characteristic of the speed ratio on the delay time of the slide valve, so that the speed ratio of the continuously variable transmission is slowly switched to the target speed ratio.
Fig. 7 is a graph of various indexes of a vehicle, including curves of throttle, vehicle speed, input shaft speed, speed ratio, slave cylinder pressure, master cylinder pressure, and speed ratio change rate, after the speed ratio of the continuously variable transmission is adjusted by applying the present invention. As shown in the figure, the speed ratio of the continuously variable transmission is adjusted by the invention, so that the actual speed ratio of the continuously variable transmission can be smoothly transited to the target speed ratio, and the pressure of the driving cylinder and the pressure of the driven cylinder can be tracked in real time, thereby avoiding abrupt change of flow of the system, further delaying the aging of the CVT and prolonging the service life of the CVT.
Exemplary, FIG. 8 is a graph of an example of various speed ratio curves including a speed ratio curve for adjusting the speed ratio of a continuously variable transmission using different control schemes, including an original target speed ratio curve, a target speed ratio curve after limiting the rate of change of the speed ratio, and a target speed ratio curve after limiting the rate of change of the speed ratio.
The original target speed ratio curve does not pass through the speed ratio curve limiting the speed ratio change rate, and the speed ratio of the continuously variable transmission is directly switched to the speed ratio with larger difference value, and the speed ratio step exists, so that the flow mutation of the system is easy to cause.
The target curve after limiting the speed ratio change rate is a speed ratio curve after limiting the speed ratio change rate, and the continuously variable transmission adjusts the speed ratio according to the limiting change rate, so that the speed ratio is gradually switched to the target curve, wherein the limiting change rate is the speed ratio change rate, the change rate can be obtained by deriving the original target speed ratio, although the speed ratio of the continuously variable transmission can be gradually switched to the target curve through limiting the change rate, and the curve can show that abrupt changes still exist from the beginning of adjustment and the arrival of the speed ratio.
The target speed ratio curve after limiting the change rate of the speed ratio is a curve obtained by deriving the target speed ratio curve after limiting the change rate of the speed ratio, namely the target curve after limiting the change rate of the change rate is a curve obtained by secondarily deriving the original target speed ratio curve, and the curve shows that the continuously variable transmission is switched to the target speed ratio in a curve mode after limiting the change rate of the change rate, so that the continuously variable transmission can be smoothly switched to the target curve, and flow fluctuation can be relieved; the current slope k1 in the graph can understand the speed ratio change rate of the target speed ratio that limits the change rate of the speed ratio change rate
Figure BDA0003375056520000161
It can also be understood that the rate of change of the speed ratio is obtained from the rate of change limiting the rate of change of the speed ratio; the final slope k0 may be understood as the target speed ratio change rate of the target speed ratio, and may be understood as the final speed ratio change rate +.>
Figure BDA0003375056520000162
△i＝i Belt_Raw -i Belt_Limit ，i Belt_Raw For the target speedRatio of; i.e Belt_Limit To a speed ratio obtained from a limited speed ratio change rate.
The limiting change rate in the drawing is a target speed ratio change rate, wherein,
Figure BDA0003375056520000163
the speed ratio change rate is expressed and can be understood as the target speed ratio change rate, wherein the speed ratio change rate is obtained by carrying out first-order derivation on the speed ratio of the steel belt, and i is as follows Belt Is the speed ratio of the steel belt.
Figure BDA0003375056520000164
Wherein Deltat is the time variation of one period, namely the time difference between the time t1 and the time t0, namely the time variation of one period; Δi Belt Is the variation of the speed ratio of the steel belt in one period, namely the speed ratio (i) at the time t1 Belt_t1 ) Speed ratio (i) to time t0 Belt_t0 ) Is a difference in (2); thus, the first and second substrates are bonded together,
Figure BDA0003375056520000165
when the speed ratio is changed +>
Figure BDA0003375056520000166
The speed ratio change rate variable range at a certain moment is defined in a certain range, and when the period is fixed, the speed ratio value and the speed ratio change rate range at the last moment are determined.
Wherein limiting the rate of change may be understood as limiting the rate of change of the target speed ratio rate of change,
Figure BDA0003375056520000167
Wherein (1)>
Figure BDA0003375056520000168
The change rate of the target speed ratio change rate is represented, and further, the change rate of the target speed ratio change rate is obtained by second-order derivation of the speed ratio of the steel belt;
Figure BDA0003375056520000171
Representing the variation of the speed ratio change rate of the steel belt in one period, namely the speed ratio change rate in the process from the time t1 to the time t2
Figure BDA0003375056520000172
Speed ratio change rate +.>
Figure BDA0003375056520000173
Is a difference in (2); the time difference between the time t1 and the time t0 is one period Deltat, and the time difference between the time t2 and the time t0 is also one period Deltat; thus, the first and second substrates are bonded together,
Figure BDA0003375056520000174
the rate of change when the target speed ratio is changed +>
Figure BDA0003375056520000175
The speed ratio variable range at a certain moment is defined in a certain range depending on the speed ratio value of the previous cycle, and the range of variation of the speed ratio change rate when the cycle is fixed.
The invention fully considers the response characteristic of the hydraulic system, ensures good tracking of actual hydraulic pressure during the speed change ratio, avoids the occurrence of pit dropping and overshoot of the actual hydraulic pressure, ensures the real-time clamping of the steel belt, and improves the fatigue life of the steel belt, wherein the change rate of the actual rotating speed is equivalent to the magnitude of moment of inertia.
Corresponding to the method shown in fig. 4, the embodiment of the present invention provides a speed ratio control device of a continuously variable transmission, which is used for supporting the application of the method shown in fig. 4 in real life, and the device provided in the embodiment of the present invention may be disposed in a control system of a vehicle, and the structural schematic diagram of the device is shown in fig. 9, and the specific description is as follows:
an obtaining unit 401, configured to obtain a current target rotational speed of a continuously variable transmission, and determine whether the continuously variable transmission meets a preset speed ratio control condition based on the target rotational speed;
a determining unit 402 configured to determine a current target speed ratio of the continuously variable transmission when it is determined that the continuously variable transmission satisfies a preset speed ratio control condition;
and an adjusting unit 403, configured to determine a target speed ratio change rate of the target speed ratio, periodically adjust the change rate of the target speed ratio change rate based on a preset speed ratio limiting policy, and adjust the speed ratio of the continuously variable transmission according to the limited speed ratio change rate obtained after the adjustment until the speed ratio of the continuously variable transmission reaches the target speed ratio.
In the device provided by the embodiment of the invention, the current target rotating speed of the continuously variable transmission is obtained, and whether the continuously variable transmission meets the preset speed ratio control condition is determined based on the target rotating speed; when the continuously variable transmission is determined to meet the preset speed ratio control condition, determining the current target speed ratio of the continuously variable transmission; determining a target speed ratio change rate of a target speed ratio, periodically adjusting the change rate of the target speed ratio change rate based on a preset speed ratio limiting strategy, and adjusting the speed ratio of the continuously variable transmission according to the limited speed ratio change rate obtained after adjustment until the speed ratio of the continuously variable transmission reaches the target speed ratio. When the continuously variable transmission meets the speed ratio control condition, the change rate of the target speed ratio change rate is periodically adjusted according to a preset speed ratio limiting strategy, and the speed ratio of the continuously variable transmission is adjusted according to the adjusted limited speed ratio change rate, so that the speed ratio of the continuously variable transmission can be smoothly switched to the target speed ratio, thereby effectively slowing down the flow fluctuation of a system, delaying the aging condition of the CVT and prolonging the service life of the CVT.
In the apparatus provided by the embodiment of the present invention, the obtaining unit 401 may be configured to:
a first obtaining subunit, configured to obtain a current accelerator opening and a current vehicle speed of a vehicle to which the continuously variable transmission belongs;
and the first processing subunit is used for processing the accelerator opening of the vehicle and the vehicle speed to obtain the target rotating speed of the continuously variable transmission.
In the apparatus provided by the embodiment of the present invention, the obtaining unit 401 may be configured to:
the second acquisition subunit is used for acquiring the current input shaft rotating speed of the continuously variable transmission;
a first determination subunit configured to determine a rotation speed difference between the input shaft rotation speed and the target rotation speed;
a second determining subunit, configured to determine whether the rotational speed difference is greater than or equal to a preset difference;
and the third determination subunit is used for determining that the continuously variable transmission meets a preset speed ratio control condition when the rotating speed difference value is larger than or equal to the preset difference value.
In the apparatus provided by the embodiment of the present invention, the determining unit 402 may be configured to:
and the second processing subunit is used for processing the target rotating speed and the input shaft rotating speed to obtain the current target speed ratio of the continuously variable transmission.
In the apparatus provided by the embodiment of the present invention, the adjusting unit 403 may be configured to:
a fourth determination subunit configured to determine an initial control period, and determine the initial control period as a first control period;
a third obtaining subunit, configured to obtain each first control parameter corresponding to the first control period;
a fourth obtaining subunit, configured to obtain, based on each of the first control parameters, a first limit range of a change rate of a target speed ratio change rate corresponding to the first control period;
a fifth determination subunit configured to determine a first limiting parameter corresponding to the first control period, and determine a first limiting value of a change rate of a target speed ratio change rate corresponding to the first control period based on the first limiting parameter and the first limiting range;
a first control subunit configured to determine a first limiting speed ratio change rate corresponding to the first limiting value, and control the continuously variable transmission to output a first speed ratio corresponding to the first control period based on the first limiting speed ratio change rate;
a first judging subunit configured to judge whether the first speed ratio is equal to the target speed ratio;
A sixth determining subunit configured to determine whether a difference between the first limited speed ratio change rate and the target speed ratio change rate is zero if the first speed ratio is not equal to the target speed ratio;
a seventh determining subunit, configured to determine a next control period if it is determined that the difference between the first limiting speed ratio change rate and the target speed ratio change rate is not zero, take the next control period as a new first control period, and return to execute the step of acquiring each first control parameter corresponding to the first control period;
an eighth determining subunit, configured to determine, if it is determined that the difference between the first limited speed ratio change rate and the target speed ratio change rate is zero, whether the difference between the first speed ratio and the target speed ratio is greater than a preset first threshold;
a ninth determining subunit, configured to determine a next control period if a difference between the first speed ratio and the target speed ratio is greater than the first threshold, and determine the next control period as a second control period;
a second control subunit configured to control the continuously variable transmission to output a second speed ratio corresponding to the second control period based on the target speed ratio change rate;
A second judging subunit configured to judge whether a difference between the second speed ratio and the target speed ratio is greater than the first threshold;
a tenth determination subunit configured to determine a next control period if a difference between the second speed ratio and the target speed ratio is greater than the first threshold, determine the next control period as a new second control period, and return to perform the step of controlling the continuously variable transmission to output a second speed ratio corresponding to the second control period based on the target speed ratio change rate;
an eleventh determination subunit configured to determine a next control period if a difference between the second speed ratio and the target speed ratio is not greater than the first threshold, and determine the next control period as a third control period;
a fifth obtaining subunit, configured to obtain each second control parameter corresponding to the third control period;
a twelfth determination subunit configured to determine, based on each of the second control parameters, a second limit range of a change rate of a target speed ratio change rate corresponding to the third control period;
a thirteenth determination subunit configured to determine a third limiting parameter corresponding to the third control period, and determine a second limiting value of a change rate of a target speed ratio change rate corresponding to the third control period based on the third limiting parameter and the second limiting range;
A third control subunit configured to determine a third limiting speed ratio change rate corresponding to the third limiting value, and control the continuously variable transmission to output a third speed ratio corresponding to the third control period based on the third limiting speed ratio change rate;
a third judging subunit configured to judge whether the third speed ratio is equal to the target speed ratio;
a fourteenth determination subunit configured to determine a next control period if the third speed ratio is not equal to the target speed ratio, determine the next control period as a new third control period, and return to perform the operation of acquiring each second control parameter corresponding to the third control period;
and the completion subunit is used for completing the control of the speed ratio of the continuously variable transmission if the third speed ratio and the like are equal to the target speed ratio.
The embodiment of the invention also provides a storage medium, which comprises stored instructions, wherein the equipment where the storage medium is controlled to execute the speed ratio control method of the continuously variable transmission when the instructions run.
The embodiment of the invention also provides an electronic device, the structure of which is shown in fig. 10, specifically including a memory 601, and one or more instructions 602, wherein the one or more instructions 602 are stored in the memory 601, and are configured to be executed by the one or more processors 603, where the one or more instructions 602 are the speed ratio control method of the continuously variable transmission.
The specific implementation process and derivative manner of the above embodiments are all within the protection scope of the present invention.
In this specification, each embodiment is described in a progressive manner, and identical and similar parts of each embodiment are all referred to each other, and each embodiment mainly describes differences from other embodiments. In particular, for a system or system embodiment, since it is substantially similar to a method embodiment, the description is relatively simple, with reference to the description of the method embodiment being made in part. The systems and system embodiments described above are merely illustrative, wherein the elements illustrated as separate elements may or may not be physically separate, and the elements shown as elements may or may not be physical elements, may be located in one place, or may be distributed over a plurality of network elements. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art will understand and implement the present invention without undue burden.
Those of skill would further appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the various illustrative elements and steps are described above generally in terms of functionality in order to clearly illustrate the interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. A speed ratio control method of a continuously variable transmission, characterized by comprising:
acquiring the current target rotating speed of the continuously variable transmission, and determining whether the continuously variable transmission meets a preset speed ratio control condition based on the target rotating speed;
when the continuously variable transmission is determined to meet a preset speed ratio control condition, determining a current target speed ratio of the continuously variable transmission;
determining a target speed ratio change rate of the target speed ratio, periodically adjusting the change rate of the target speed ratio change rate based on a preset speed ratio limiting strategy, and adjusting the speed ratio of the continuously variable transmission according to the limited speed ratio change rate obtained after adjustment until the speed ratio of the continuously variable transmission reaches the target speed ratio.
2. The method according to claim 1, wherein the obtaining the current target rotational speed of the continuously variable transmission includes;
acquiring the current accelerator opening and the current speed of a vehicle to which the continuously variable transmission belongs;
and processing the accelerator opening of the vehicle and the vehicle speed to obtain the target rotating speed of the continuously variable transmission.
3. The method according to claim 1, wherein the determining whether the continuously variable transmission satisfies a preset speed ratio control condition based on the target rotational speed includes:
acquiring the current input shaft rotating speed of the continuously variable transmission;
determining a rotational speed difference between the input shaft rotational speed and the target rotational speed;
determining whether the rotational speed difference is greater than or equal to a preset difference;
and when the rotating speed difference value is larger than or equal to the preset difference value, determining that the continuously variable transmission meets a preset speed ratio control condition.
4. The method of claim 3, wherein the determining the current target speed ratio of the continuously variable transmission comprises:
and processing the target rotating speed and the input shaft rotating speed to obtain the current target speed ratio of the continuously variable transmission.
5. The method according to claim 1, wherein the periodically adjusting the change rate of the target speed ratio change rate based on a preset speed ratio limiting strategy, and adjusting the speed ratio of the continuously variable transmission according to the adjusted limited speed ratio change rate until the speed ratio of the continuously variable transmission reaches the target speed ratio, includes:
Determining an initial control period, and determining the initial control period as a first control period;
acquiring each first control parameter corresponding to the first control period;
obtaining a first limiting range of the change rate of the target speed ratio change rate corresponding to the first control period based on each first control parameter;
determining a first limiting parameter corresponding to the first control period, and determining a first limiting value of a change rate of a target speed ratio change rate corresponding to the first control period based on the first limiting parameter and the first limiting range;
determining a first limiting speed ratio change rate corresponding to the first limiting value, and controlling the continuously variable transmission to output a first speed ratio corresponding to the first control period based on the first limiting speed ratio change rate;
judging whether the first speed ratio is equal to the target speed ratio;
if the first speed ratio is not equal to the target speed ratio, determining whether a difference between the first limiting speed ratio change rate and the target speed ratio change rate is zero;
if the difference between the first limiting speed ratio change rate and the target speed ratio change rate is not zero, determining a next control period, taking the next control period as a new first control period, and returning to execute the step of acquiring each first control parameter corresponding to the first control period;
If the difference between the first limiting speed ratio change rate and the target speed ratio change rate is zero, determining whether the difference between the first speed ratio and the target speed ratio is greater than a preset first threshold;
if the difference between the first speed ratio and the target speed ratio is greater than the first threshold, determining a next control period, and determining the next control period as a second control period;
controlling the continuously variable transmission to output a second speed ratio corresponding to the second control period based on the target speed ratio change rate;
judging whether the difference between the second speed ratio and the target speed ratio is larger than the first threshold value;
if the difference between the second speed ratio and the target speed ratio is greater than the first threshold, determining a next control period, determining the next control period as a new second control period, and returning to execute the step of controlling the continuously variable transmission to output a second speed ratio corresponding to the second control period based on the target speed ratio change rate;
if the difference between the second speed ratio and the target speed ratio is not greater than the first threshold, determining a next control period, and determining the next control period as a third control period;
Acquiring each second control parameter corresponding to the third control period;
determining a second limit range of a change rate of a target speed ratio change rate corresponding to the third control period based on each of the second control parameters;
determining a third limiting parameter corresponding to the third control period, and determining a second limiting value of a change rate of a target speed ratio change rate corresponding to the third control period based on the third limiting parameter and the second limiting range;
determining a third limiting speed ratio change rate corresponding to the third limiting value, and controlling the continuously variable transmission to output a third speed ratio corresponding to the third control period based on the third limiting speed ratio change rate;
judging whether the third speed ratio is equal to the target speed ratio;
if the third speed ratio is not equal to the target speed ratio, determining a next control period, determining the next control period as a new third control period, and returning to execute the operation of acquiring each second control parameter corresponding to the third control period;
and if the third speed ratio and the like are equal to the target speed ratio, completing the control of the speed ratio of the continuously variable transmission.
6. A speed ratio control apparatus of a continuously variable transmission, comprising:
an acquisition unit, configured to acquire a current target rotational speed of a continuously variable transmission, and determine whether the continuously variable transmission meets a preset speed ratio control condition based on the target rotational speed;
a determining unit configured to determine a current target speed ratio of the continuously variable transmission when it is determined that the continuously variable transmission satisfies a preset speed ratio control condition;
the adjusting unit is used for determining a target speed ratio change rate of the target speed ratio, periodically adjusting the change rate of the target speed ratio change rate based on a preset speed ratio limiting strategy, and adjusting the speed ratio of the continuously variable transmission according to the limited speed ratio change rate obtained after adjustment until the speed ratio of the continuously variable transmission reaches the target speed ratio.
7. The apparatus of claim 6, wherein the acquisition unit comprises:
a first obtaining subunit, configured to obtain a current accelerator opening and a current vehicle speed of a vehicle to which the continuously variable transmission belongs;
and the first processing subunit is used for processing the accelerator opening of the vehicle and the vehicle speed to obtain the target rotating speed of the continuously variable transmission.
8. The apparatus of claim 6, wherein the acquisition unit comprises:
the second acquisition subunit is used for acquiring the current input shaft rotating speed of the continuously variable transmission;
a first determination subunit configured to determine a rotation speed difference between the input shaft rotation speed and the target rotation speed;
a second determining subunit, configured to determine whether the rotational speed difference is greater than or equal to a preset difference;
and the third determination subunit is used for determining that the continuously variable transmission meets a preset speed ratio control condition when the rotating speed difference value is larger than or equal to the preset difference value.
9. A storage medium comprising stored instructions, wherein the instructions, when executed, control an apparatus in which the storage medium is located to perform the speed ratio control method of the continuously variable transmission according to any one of claims 1 to 5.
10. An electronic device comprising a memory, and one or more instructions, wherein the one or more instructions are stored in the memory and configured to be executed by the one or more processors to perform the ratio control method of the continuously variable transmission of any one of claims 1-5.
CN202111415334.1A 2021-11-25 2021-11-25 Speed ratio control method and device for continuously variable transmission, storage medium and electronic equipment Pending CN116164100A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202111415334.1A CN116164100A (en) 2021-11-25 2021-11-25 Speed ratio control method and device for continuously variable transmission, storage medium and electronic equipment

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202111415334.1A CN116164100A (en) 2021-11-25 2021-11-25 Speed ratio control method and device for continuously variable transmission, storage medium and electronic equipment

Publications (1)

Publication Number Publication Date
CN116164100A true CN116164100A (en) 2023-05-26

Family

ID=86411922

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202111415334.1A Pending CN116164100A (en) 2021-11-25 2021-11-25 Speed ratio control method and device for continuously variable transmission, storage medium and electronic equipment

Country Status (1)

Country Link
CN (1) CN116164100A (en)

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4653005A (en) * 1983-09-01 1987-03-24 Toyota Jidosha Kabushiki Kaisha Method and apparatus for controlling continuously variable transmission for vehicle
US4658360A (en) * 1983-09-01 1987-04-14 Toyota Jidosha Kabushiki Kaisha Method and apparatus for controlling continuously variable transmission for vehicle
US4683779A (en) * 1983-09-01 1987-08-04 Toyota Jidosha Kabushiki Kaisha Method and apparatus for controlling continuously variable transmission for vehicle
US20060240942A1 (en) * 2005-04-26 2006-10-26 Jatco Ltd Shift control apparatus and method for continuously variable transmission
CN106062433A (en) * 2014-03-10 2016-10-26 爱信艾达株式会社 Control device and control method for continuously variable transmission
CN108386534A (en) * 2018-04-12 2018-08-10 吉林大学 A kind of clamping force of metal band type stepless speed variator than test method
CN109185449A (en) * 2018-10-16 2019-01-11 吉林大学 A kind of metal band type stepless speed variator goals ratio change rate calculation method

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4653005A (en) * 1983-09-01 1987-03-24 Toyota Jidosha Kabushiki Kaisha Method and apparatus for controlling continuously variable transmission for vehicle
US4658360A (en) * 1983-09-01 1987-04-14 Toyota Jidosha Kabushiki Kaisha Method and apparatus for controlling continuously variable transmission for vehicle
US4683779A (en) * 1983-09-01 1987-08-04 Toyota Jidosha Kabushiki Kaisha Method and apparatus for controlling continuously variable transmission for vehicle
US20060240942A1 (en) * 2005-04-26 2006-10-26 Jatco Ltd Shift control apparatus and method for continuously variable transmission
CN106062433A (en) * 2014-03-10 2016-10-26 爱信艾达株式会社 Control device and control method for continuously variable transmission
CN108386534A (en) * 2018-04-12 2018-08-10 吉林大学 A kind of clamping force of metal band type stepless speed variator than test method
CN109185449A (en) * 2018-10-16 2019-01-11 吉林大学 A kind of metal band type stepless speed variator goals ratio change rate calculation method

Similar Documents

Publication Publication Date Title
EP1394445B1 (en) Hydraulic pressure control for continuously variable transmission
US4872115A (en) Apparatus for controlling continuously variable transmission
JP2003202039A (en) Automatic friction clutch control device
CN110630375B (en) An engine braking power control method and system
JPS60260753A (en) Control device of stepless speed change gear for car
JPH03125032A (en) Control device for automatic take-off clutch
CN114215861B (en) Clutch intelligent adjustment method, device, equipment and storage medium
JP3042684B2 (en) Shift control method for belt-type continuously variable transmission
CN103277507A (en) Shift control of continuously variable transmission
US20020065597A1 (en) Vehicle drive force control
CN112622866A (en) Engine rotating speed adjusting method and device, vehicle electric control device and medium
CN113864441A (en) Vehicle gear shifting control method, vehicle and computer readable storage medium
US5540632A (en) Control process and control arrangement for a continuously variable speed transmission
US8965647B2 (en) Control apparatus for continuously variable transmission
JPH08219244A (en) Controller for continuously variable transmission
CN113442926B (en) Intelligent auxiliary gear shifting method
CN115929899B (en) Vehicle control method and device, vehicle and storage medium
CN103758994A (en) Automatic gearbox self-adaption optimization gear-shifting control method
CN116164100A (en) Speed ratio control method and device for continuously variable transmission, storage medium and electronic equipment
CN109606371A (en) Engine and speed changer control method for coordinating in gearshift procedure
CN114251446B (en) A shift control method and device for an AMT engine
US6409630B1 (en) Power off upshift control method for automatic transmission
JP3591390B2 (en) Transmission control device for continuously variable transmission
JP3427736B2 (en) Transmission control device for continuously variable transmission
JP2000054876A (en) Vehicle driving force control device

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination