KR20220051893A - Dynamic radius of vehicle tire learning method - Google Patents

Abstract

The present invention comprises the following steps of: determining whether a vehicle driving condition required for learning a tire dynamic load radius is satisfied; determining whether the state in which the vehicle driving condition is satisfied is maintained for more than a predetermined standard time; and when the vehicle driving condition is maintained more than the predetermined time, calculating the tire dynamic load radius by using a GPS-based vehicle velocity and a transmission input shaft velocity sensing value and updating the tire dynamic load radius by using the calculated value. According to the present invention, various controls on a vehicle using the dynamic load radius are accurately performed to improve marketability of the vehicle.

Description

Method of learning the dynamic load radius of a vehicle's tire {DYNAMIC RADIUS OF VEHICLE TIRE LEARNING METHOD}

The present invention relates to a technology for varying a tire dynamic load radius of a vehicle according to an actual situation of the vehicle.

The radius of the tire in the state of being mounted on the vehicle and supporting the vertical load due to the weight of the vehicle body is small compared to the radius of the state in which the tire is not mounted on the vehicle. The radius of the tire in the driving situation is called the dynamic radius.

The dynamic load radius is larger than the static load radius, and varies depending on the number of passengers in the vehicle, the load, and air pressure.

On the other hand, in a transmission such as an automatic transmission or DCT (Dual Clutch Transmission) mounted on a vehicle, when shifting, the rotation speed of a power source such as an engine or a motor and the rotation speed of the transmission input shaft are compared to determine whether the clutch connecting them slips and the amount of slip is determined, and accordingly, it is determined whether the shift has been completed.

In general, speed sensors are provided in the engine, motor, and transmission input shaft, respectively, and by comparing the directly sensed rotation speeds, it is possible to calculate whether the clutch connecting the power source and the transmission input shaft slips and the slip amount.

However, since the gear ratio of the transmission changes during shifting, the input shaft speed sensor cannot accurately detect the target speed of the transmission input shaft at the target gear stage. and calculating the transmission input shaft speed using the tire dynamic load radius, and performing shift control while determining whether the clutch slips and the slip amount using the calculated transmission input shaft speed.

Here, the dynamic load radius for calculating the speed of the transmission input shaft continuously changes depending on various factors such as the number of passengers, load amount, air pressure, etc. as described above. The transmission input shaft calculated using the dynamic load radius that does not reflect these changes When shift control is performed using speed, a side effect of a decrease in shift feeling due to shift shock or shift time delay may be accompanied.

The matters described as the background technology of the present invention are only for enhancing the understanding of the background of the present invention, and should not be taken as acknowledging that they correspond to the prior art already known to those of ordinary skill in the art. will be

KR 10-2008-0007701 A

According to the present invention, the dynamic load radius of the tire that changes according to the driving condition of the vehicle can be appropriately learned and updated according to the actual condition of the vehicle. It is an object of the present invention to provide a method for learning the dynamic load radius of a tire of a vehicle so that it can be performed in a manner that can ultimately improve the marketability of the vehicle.

The tire dynamic load radius learning method of the vehicle of the present invention for achieving the object as described above,

determining whether a vehicle driving condition required for tire dynamic load radius learning is satisfied;

determining whether the state satisfying the vehicle driving condition is maintained for a predetermined reference time or longer;

calculating a tire dynamic load radius using the GPS-based vehicle speed and a transmission input shaft speed sensing value when the vehicle driving condition is maintained for more than a reference time, and updating the tire dynamic load radius with the calculated value;

It is characterized in that it comprises a.

The vehicle driving conditions required for learning the dynamic load radius are

If the steering angle is within the predetermined first reference range, it is possible to confirm the straight-line driving of the vehicle;

When the gradient of the driving road is within a predetermined second reference range, it is possible to confirm the vehicle's driving on flat ground;

When the acceleration of the vehicle is within a predetermined third reference range, and it is possible to confirm the constant speed driving of the vehicle, it may be satisfied.

The tire dynamic load radius is calculated by the following formula,

Rd_C = V_G*FGR*GR*60*1000/(IS_S*2*π*3600)

here,

Rd_C: Calculated dynamic load radius [m]

V_G: GPS-based vehicle speed [km/h]

FGR: final reduction ratio

GR: gear ratio

IS_S: Transmission input shaft speed sensed by the sensor [min ^-1 ]

can be calculated by

In addition, the shift control method of the vehicle of the present invention for achieving the object as described above,

determining whether a vehicle driving condition required for tire dynamic load radius learning is satisfied;

determining whether the state satisfying the vehicle driving condition is maintained for a predetermined reference time or longer;

calculating a tire dynamic load radius using the GPS-based vehicle speed and a transmission input shaft speed sensing value when the vehicle driving condition is maintained for more than a reference time, and updating the tire dynamic load radius with the calculated value;

calculating a transmission input shaft speed by using the updated dynamic load radius when a shift command is generated;

performing shifting using the calculated transmission input shaft speed;

It is characterized in that it comprises a.

The vehicle driving conditions required for learning the dynamic load radius are

If the steering angle is within the predetermined first reference range, it is possible to confirm the straight-line driving of the vehicle;

When the gradient of the driving road is within a predetermined second reference range, it is possible to confirm the vehicle's driving on flat ground;

When the acceleration of the vehicle is within a predetermined third reference range, and it is possible to confirm the constant speed driving of the vehicle, it may be satisfied.

The tire dynamic load radius is calculated by the following formula,

Rd_C = V_G*FGR*GR*60*1000/(IS_S*2*π*3600)

here,

Rd_C: Calculated dynamic load radius [m]

V_G: GPS-based vehicle speed [km/h]

FGR: final reduction ratio

GR: gear ratio

IS_S: Transmission input shaft speed sensed by the sensor [min ^-1 ]

It can be calculated by .

Calculation of the transmission input shaft speed is the following formula,

IS_C = V_W*FGR*GR*60*1000/(Rd_C*2*ð*3600)

here,

IS_C: Calculated transmission input shaft speed [min ^-1 ]

V_W: Wheel speed sensor-based vehicle speed [km/h]

FGR: final reduction ratio

GR: gear ratio

Rd_C: Calculated dynamic load radius [m]

It can be calculated by .

According to the present invention, the dynamic load radius of the tire, which changes according to the driving condition of the vehicle, can be appropriately learned and updated according to the actual condition of the vehicle.

In addition, various controls of the vehicle using the dynamic load radius, such as shift control of the vehicle, can be performed more accurately and appropriately, thereby ultimately improving the commercial properties of the vehicle.

1 is a diagram illustrating the configuration of a vehicle equipped with a DCT to which a method for learning a tire dynamic load radius of a vehicle and a shift control method according to the present invention can be applied;
2 is a flowchart illustrating a method for learning a tire dynamic load radius of a vehicle and a shift control method according to the present invention;
3 is a graph illustrating the effects of a method for learning a tire dynamic load radius of a vehicle and a shift control method according to the present invention.

Specific structural or functional descriptions of the embodiments of the present invention disclosed in the present specification or application are only exemplified for the purpose of describing the embodiments according to the present invention, and the embodiments according to the present invention may be implemented in various forms. and should not be construed as being limited to the embodiments described in the present specification or application.

Since the embodiment according to the present invention can have various changes and can have various forms, specific embodiments are illustrated in the drawings and described in detail in the present specification or application. However, this is not intended to limit the embodiment according to the concept of the present invention with respect to a specific disclosed form, and should be understood to include all changes, equivalents or substitutes included in the spirit and scope of the present invention.

Terms such as first and/or second may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one element from another element, for example, without departing from the scope of the present invention, a first element may be called a second element, and similarly The second component may also be referred to as the first component.

When an element is referred to as being “connected” or “connected” to another element, it is understood that it may be directly connected or connected to the other element, but other elements may exist in between. it should be On the other hand, when it is said that a certain element is "directly connected" or "directly connected" to another element, it should be understood that the other element does not exist in the middle. Other expressions describing the relationship between elements, such as "between" and "immediately between" or "neighboring to" and "directly adjacent to", etc., should be interpreted similarly.

The terms used herein are used only to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present specification, terms such as “comprise” or “have” are intended to designate that the described feature, number, step, operation, component, part, or a combination thereof exists, and includes one or more other features or numbers. , it should be understood that it does not preclude the existence or addition of steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as meanings consistent with the context of the related art, and unless explicitly defined in the present specification, they are not to be interpreted in an ideal or excessively formal meaning. .

Hereinafter, the present invention will be described in detail by describing preferred embodiments of the present invention with reference to the accompanying drawings. Like reference numerals in each figure indicate like elements.

1 illustrates the configuration of a DCT vehicle to which the present invention can be applied, the power of the engine E is selectively provided to the two input shafts I1 and I2 through the two clutches CL1 and CL2 of the DCT, and the DCT The power for which the shift has been completed is provided to the driving wheels W.

The controller (CLR) is connected to the ECU (Engine Control Unit) to receive information such as engine torque and to make a request such as torque reduction to the engine (E), and a clutch actuator (CA) that controls the two clutches of the DCT It is connected to control the gear actuator (GA) that changes the gear meshing state of the DCT and the DCT.

The controller CLR is configured to receive a signal from the accelerator pedal sensor APS, and is configured to receive the rotational speed of each input shaft I1 and I2 of the DCT.

Here, the two clutches CL1 and CL2 respectively connected to the two input shafts I1 and I2 are connected to the input shaft used to implement the current shift stage during shifting is referred to as a 'release side clutch', and a target shift stage to be shifted is implemented. The one connected to the input shaft used for

Referring to FIG. 2 , an embodiment of a method for learning a tire dynamic load radius of a vehicle according to the present invention includes the steps of determining whether a vehicle driving condition required for learning a tire dynamic load radius is satisfied ( S10 ); determining whether the state satisfying the vehicle driving condition is maintained for more than a predetermined reference time (S20); If the vehicle driving condition is maintained for more than the reference time, calculating the tire dynamic load radius using the GPS-based vehicle speed and the transmission input shaft speed sensing value, and updating the tire dynamic load radius with the calculated value (S30). .

That is, the present invention is to substantially calculate and update a tire dynamic load radius using a GPS-based vehicle speed and a transmission input shaft speed sensing value measured by a sensor when a predetermined vehicle driving condition is stably secured.

Therefore, since the dynamic load radius of the tire is updated in real time by reflecting the driving condition of the vehicle as described above, when controlling the vehicle using the dynamic load radius, the effect of further improving the control accuracy can be obtained. will be.

The vehicle driving condition required for learning the dynamic load radius is that the steering angle is within a predetermined first reference range, so that straight-line driving of the vehicle can be confirmed; When the gradient of the driving road is within a predetermined second reference range, it is possible to confirm the vehicle's driving on flat ground; It is assumed that the vehicle acceleration is satisfied when the vehicle acceleration is within the predetermined third reference range, and the vehicle can confirm the constant speed running.

This is to improve the accuracy of the GPS-based vehicle speed used in the calculation of the dynamic load radius and the transmission input shaft speed sensing value measured by the sensor, so that the dynamic load radius can be accurately calculated.

Accordingly, the first reference range, the second reference range, and the third reference range can determine whether the vehicle is traveling straight ahead, it can be confirmed that the road on which the vehicle is traveling is flat, and the vehicle accelerates. Alternatively, it is set to a level at which it can be confirmed that the vehicle is traveling at a constant speed without deceleration, and may be set, for example, as illustrated in FIG. 2 .

Here, the GPS-based vehicle speed means a vehicle speed calculated based on a signal of a GPS (Global Positioning System) constituting a navigation mounted on a vehicle or a separate GPS sensor.

In addition, the reference time is to check whether the state in which the vehicle driving conditions are satisfied as described above is stable, to exclude the influence of noise, etc., and to enable accurate and stable calculation of the dynamic load radius, for example, 3 seconds, etc. can be set together.

On the other hand, the calculation of the tire dynamic load radius is the following formula,

Rd_C = V_G*FGR*GR*60*1000/(IS_S*2*π*3600)

here,

Rd_C: Calculated dynamic load radius [m]

V_G: GPS-based vehicle speed [km/h]

FGR: final reduction ratio

GR: gear ratio

IS_S: Transmission input shaft speed sensed by the sensor [min ^-1 ]

is calculated by

The dynamic load radius calculated in this way is all factors that substantially affect the dynamic load radius of the tire, such as the number of passengers currently in the vehicle, the load capacity, and the air pressure, as well as the wheel's inch up by the user's tuning. As is reflected, it can be seen that it has the most practical and accurate value in vehicle control.

For reference, the dynamic load radius accurately calculated as described above may be utilized for calculating the driving force or braking force of the vehicle, using the same for braking control, vehicle attitude control, and the like.

Hereinafter, in the case of controlling the vehicle using the dynamic load radius accurately calculated as described above, the shift control of the vehicle will be described.

For reference, FIG. 2 shows the method of learning the dynamic load radius of the vehicle and the method of controlling the shift of the vehicle using the same. An embodiment of the method of controlling the shift of the vehicle according to the present invention is a vehicle driving required for learning the radius of dynamic load of a tire. determining whether a condition is satisfied (S10); determining whether the state satisfying the vehicle driving condition is maintained for more than a predetermined reference time (S20); If the vehicle driving condition is maintained for more than a reference time, calculating a tire dynamic load radius using the GPS-based vehicle speed and the transmission input shaft speed sensing value, and updating the tire dynamic load radius with the calculated value (S30); calculating a transmission input shaft speed by using the updated dynamic load radius when a shift command is generated (S40); and performing a shift using the calculated transmission input shaft speed (S50).

That is, the method for calculating the tire dynamic load radius is the same, and it is inappropriate to measure the transmission input shaft speed by a sensor during a shift when a shift command is generated. , by using the calculated transmission input shaft speed to perform shifting, to prevent shift shock and shift delay with more accurate shift control, thereby improving shifting feeling.

Here, the calculation of the transmission input shaft speed is the following formula,

IS_C = V_W*FGR*GR*60*1000/(Rd_C*2*ð*3600)

here,

IS_C: Calculated transmission input shaft speed [min ^-1 ]

V_W: Wheel speed sensor-based vehicle speed [km/h]

FGR: final reduction ratio

GR: gear ratio

Rd_C: Calculated dynamic load radius [m]

can be calculated by

For reference, in the above formula, the wheel speed sensor-based vehicle speed is used as the vehicle speed, so the dynamic load radius is calculated based on the vehicle speed calculated based on the signal output from the wheel speed sensor, but in addition, the speed installed to measure the transmission output shaft speed It will be possible to use the vehicle speed based on the signal from the sensor, and even in the case of the vehicle speed based on the wheel speed sensor, the average vehicle speed may be calculated and used using the signals of the wheel speed sensors of all wheels, and the signals of the wheel speed sensors of the driving wheels It is also possible to use the average vehicle speed using only the

For reference, the shift command of the vehicle is not generated only at the time indicated on the flowchart of FIG. 2 . That is, a shift command of the vehicle may occur regardless of the calculation of the tire dynamic load radius, and in this case, the shift is performed using the previously stored dynamic load radius, where the previously stored dynamic load radius is generally It may be a value updated by the previously performed dynamic load radius learning, but in the case of an initial state in which there is no previous learning, it will be a representative value provided by a tire manufacturer, etc.

FIG. 3 is a graph for explaining the effect of the method for learning the dynamic load radius of a vehicle of a vehicle as described above and a method for controlling a shift of a vehicle using the same, and describes a situation in which a power off/downshift is performed.

When the shift is started, the release-side clutch torque is released to enter an actual shift section in which the speed of the engine, which is a power source connected to the release-side input shaft through the release-side clutch, is different from the release-side input shaft speed, and at this time, the engine torque is increased so that the engine speed is synchronized with the transmission input shaft speed of the target gear stage, that is, the engagement-side input shaft speed, and then the engagement-side clutch is engaged to complete the shift.

In the shift process as described above, since it is impossible to directly measure the speed of the transmission input shaft of the target gear stage as described above, the one calculated using the dynamic load radius is used. The stage input shaft speed can be calculated, and by controlling the engine speed accordingly, the shift can proceed smoothly and smoothly without shift shock or shift delay. For example, as indicated below the target shift stage input shaft speed according to the present invention, When the engine speed is controlled to follow the target shift stage input shaft speed with an error using the dynamic load radius that does not reflect the actual situation of etc. may occur.

Although the present invention has been shown and described with reference to specific embodiments, it is within the art that the present invention can be variously improved and changed without departing from the spirit of the present invention provided by the following claims. It will be obvious to those of ordinary skill in the art.

E; engine
CL1, CL2; clutch
I1, I2; gearbox input shaft
W; drive wheel
CLR; controller
CA; clutch actuator
GA; gear actuator
APS; accelerator pedal sensor

Claims (7)

determining whether a vehicle driving condition required for tire dynamic load radius learning is satisfied;
determining whether the state satisfying the vehicle driving condition is maintained for a predetermined reference time or longer;
calculating a tire dynamic load radius using the GPS-based vehicle speed and a transmission input shaft speed sensing value when the vehicle driving condition is maintained for more than a reference time, and updating the tire dynamic load radius with the calculated value;
Tire dynamic load radius learning method of a vehicle, characterized in that it comprises a. The method according to claim 1,
The vehicle driving conditions required for learning the dynamic load radius are
If the steering angle is within the predetermined first reference range, it is possible to confirm the straight-line driving of the vehicle;
When the gradient of the driving road is within a predetermined second reference range, it is possible to confirm the vehicle's driving on flat ground;
What is satisfied when the vehicle's acceleration is within the predetermined third reference range and the constant speed driving of the vehicle can be confirmed
A method of learning the tire dynamic load radius of a vehicle, characterized in that The method according to claim 1,
The tire dynamic load radius is calculated by the following formula,
Rd_C = V*FGR*GR*60*1000/(IS_S*2*π*3600)
here,
Rd_C: Calculated dynamic load radius [m]
V_G: GPS-based vehicle speed [km/h]
FGR: final reduction ratio
GR: gear ratio
IS_S: Transmission input shaft speed sensed by the sensor [min ^-1 ]
A method of learning the dynamic load radius of a vehicle tire, characterized in that it is calculated by determining whether a vehicle driving condition required for tire dynamic load radius learning is satisfied;
determining whether the state satisfying the vehicle driving condition is maintained for a predetermined reference time or longer;
calculating a tire dynamic load radius using the GPS-based vehicle speed and a transmission input shaft speed sensing value when the vehicle driving condition is maintained for more than a reference time, and updating the tire dynamic load radius with the calculated value;
calculating a transmission input shaft speed by using the updated dynamic load radius when a shift command is generated;
performing shifting using the calculated transmission input shaft speed;
A vehicle shift control method comprising a. 5. The method according to claim 4,
The vehicle driving conditions required for learning the dynamic load radius are
If the steering angle is within the predetermined first reference range, it is possible to confirm the straight-line driving of the vehicle;
When the gradient of the driving road is within a predetermined second reference range, it is possible to confirm the vehicle's driving on flat ground;
What is satisfied when the vehicle's acceleration is within the predetermined third reference range and the constant speed driving of the vehicle can be confirmed
A vehicle shift control method, characterized in that. 6. The method of claim 5,
The tire dynamic load radius is calculated by the following formula,
Rd_C = V_G*FGR*GR*60*1000/(IS_S*2*π*3600)
here,
Rd_C: Calculated dynamic load radius [m]
V_G: GPS-based vehicle speed [km/h]
FGR: final reduction ratio
GR: gear ratio
IS_S: Transmission input shaft speed sensed by the sensor [min ^-1 ]
A shift control method of a vehicle, characterized in that it is calculated by 7. The method of claim 6,
Calculation of the transmission input shaft speed is the following formula,
IS_C = V_W*FGR*GR*60*1000/(Rd_C*2*ð*3600)
here,
IS_C: Calculated transmission input shaft speed [min ^-1 ]
V_W: Wheel speed sensor-based vehicle speed [km/h]
FGR: final reduction ratio
GR: gear ratio
Rd_C: Calculated dynamic load radius [m]
A shift control method of a vehicle, characterized in that it is calculated by

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