WO2020025378A1 - Method for controlling the steering ratio of a vehicle provided with wheels based on the moving direction of the vehicle and a system thereof - Google Patents

Method for controlling the steering ratio of a vehicle provided with wheels based on the moving direction of the vehicle and a system thereof Download PDF

Info

Publication number
WO2020025378A1
WO2020025378A1 PCT/EP2019/069651 EP2019069651W WO2020025378A1 WO 2020025378 A1 WO2020025378 A1 WO 2020025378A1 EP 2019069651 W EP2019069651 W EP 2019069651W WO 2020025378 A1 WO2020025378 A1 WO 2020025378A1
Authority
WO
WIPO (PCT)
Prior art keywords
steering ratio
profile
steering
vehicle
backward
Prior art date
Application number
PCT/EP2019/069651
Other languages
French (fr)
Inventor
Phil Brown
Michael GEIRHOFER
Michele MANTOVANI
Giuseppe Panetta
Original Assignee
Cnh Industrial Italia S.P.A.
Cnh Industrial America Llc
Cnh (China) Management Co., Ltd
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 Cnh Industrial Italia S.P.A., Cnh Industrial America Llc, Cnh (China) Management Co., Ltd filed Critical Cnh Industrial Italia S.P.A.
Priority to EP19742373.4A priority Critical patent/EP3829957A1/en
Publication of WO2020025378A1 publication Critical patent/WO2020025378A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D5/00—Power-assisted or power-driven steering
    • B62D5/008—Changing the transfer ratio between the steering wheel and the steering gear by variable supply of energy, e.g. by using a superposition gear
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D6/00—Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits
    • B62D6/007—Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits adjustable by the driver, e.g. sport mode
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D6/00—Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits
    • B62D6/02—Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits responsive only to vehicle speed

Definitions

  • the present invention relates to a method for controlling the steering ratio of a vehicle provided with wheels based on the moving direction of the vehicle and a system thereof.
  • steering ratio refers to the ratio between the turns of the steering wheel (in degrees ) or handlebars and the turns of the wheels (in degrees ) .
  • the steering ratio is the ratio of the number of degrees of turn of the steering wheel to the number of degrees the wheel (s) turn as a result .
  • a higher steering ratio means that the steering wheel is turned more to get the wheels fully turning, and a lower steering ratio means that the steering wheel is turned less to get the wheels fully turning .
  • the steering ratio may be modified in function of the speed of the vehicle so that the steering ratio is increased with the speed of the vehicle to enhance driving safety .
  • the present invention is focused on the control of the steering wheel ratio that takes into consideration both the speed of the vehicle and the driving direction .
  • the present invention relates to a method for controlling the steering ratio of a vehicle provided with wheels and a system thereof, according to the appended claims.
  • the method according to an embodiment of the invention comprises the steps of: detecting a steering request signal; actuating the movement of the wheels based on the steering request signal and based on a steering ratio that is function of the speed of the vehicle; detecting if the vehicle is configured for moving in a forward or a backward direction; in case of forward direction, automatically selecting a forward steering ratio profile expressing the value of the steering ratio in function of the speed of the vehicle and actuating the turn of wheels based on the steering ratio determined by means of the forward steering ratio profile; in case of backward direction, automatically selecting a backward steering ratio profile expressing the value of the steering ratio in function of the speed of the vehicle and actuating the turn of wheels based on the steering ratio determined by means of backward steering ratio profile; the forward steering ratio profile being independent from the backward steering ratio profile.
  • a customizing step is provided where the one or both forward or backward profiles may be modified by the user based on a driver's request; more specifically, the user may customize the steering ratio profiles by means of an algorithm that modifies some parameters of an existing standard pre-defined profile to create a customized profile.
  • the system comprises a detector for detecting a steering request signal, and an actuator for actuating the movement of the wheels based on the steering request signal and based on a steering ratio that is function of the speed of the vehicle, wherein
  • the detector is configured for detecting if the vehicle is moving in a forward or a backward direction;
  • the selector is configured for automatically selecting, in case of forward direction, a forward steering ratio profile expressing the value of the steering ratio in function of the speed of the vehicle and, in case of backward direction, a backward steering ratio profile expressing the value of the steering ratio in function of the speed of the vehicle;
  • the actuator is configured for actuating the turn of wheels based, in case of forward direction, on the steering ratio determined by means of the forward steering ratio profile and, in case of backward direction, on the steering ratio determined by means of backward steering ratio profile; the forward steering ratio profile being independent from the backward steering ratio profile.
  • the one or both forward or backward profiles may be modified by a user based on a driver's request; more specifically, the user may customize the steering ratio profiles by means of an algorithm that modifies some parameters of an existing standard pre-defined profile to create a customized profile .
  • the steering ratio is always selected to be the most suitable as driving conditions and backward driving conditions are quite different one with respect to the other .
  • the user has moreover the ability to change the steering ratio taking into consideration the specific driving condition, his driving experience and his habits .
  • the steering ratio is thus "tailored" to the driver by the driver himself .
  • Figure 1 represents in a schematic manner the main elements that are involved in the method according to the present invention
  • Figure 2 is a diagram showing a phase of the method of the present invention.
  • FIG. 3 is a diagram showing another phase of the method of the present invention.
  • Figure 4 schematically shows a system according to the present invention .
  • the elements shown in figure 1 are installed on a vehicle provided with wheels , more particularly an agricultural vehicle for instance a tractor .
  • the vehicle is controlled by a system 10 , schematically shown in figure 4.
  • the vehicle is provided with at least one couple of steering wheels (not shown) which is actuated by a hydraulic system (of known kind, not shown) that receives working fluid in pressure (oil for instance) from a steering valve 2 whose disposition concurs in regulating the steering angle actuated by the steering wheels .
  • a hydraulic system of known kind, not shown
  • the steering valve 2 is electrically controlled by a steering valve controller 3 of known kind .
  • a vehicle controller 4 controls the engine and power transmission of the vehicle and cooperates with the steering valve controller 3.
  • a steering command signal St from the steering wheel actuated by the driver may be received by the vehicle controller 4 or alternatively by the steering valve controller 3.
  • the vehicle controller 4 receives control signal from a gear selector 6 that is provided to implement forward gears , backward gears and neutral and parking positions .
  • the vehicle controller 4 (or the steering valve controller 3 ) has to translate the steering command signal St in order to provide a suitable signal for the valve controller 3 by using a memorized value of the steering ratio that defines the ratio between the turn of the steering wheel (in degrees ) and the turn of the wheels (in degrees ) .
  • two profiles of steering ratio are memorized in the steering valve controller 3 namely : - a forward steering ratio profile (figure 2) expressing the value of the steering ratio in function of the speed of the vehicle ;
  • the forward steering ratio profile and the backward steering ratio profile are independent one with the other.
  • the steering ratio profiles present different shapes.
  • the forward steering ratio profile is automatically selected if the driver intends to use a forward gear and the backward steering ratio profile is automatically selected if the drivers intends to use a backward gear; this automatic selection may be implemented, for instance, by monitoring the position of the gear selector 6. Such selection between the forward steering ratio profile and the backward steering ration profile is performed, as reported in the in figure 4, through a selector 22.
  • the following steps are implemented according to the method of the present invention: detecting if the vehicle is configured for moving in a forward or a backward direction; in case of forward direction, automatically selecting the forward steering ratio profile expressing the value of the steering ratio in function of the speed of the vehicle and actuating the turn of wheels based on the steering ratio determined by means of the forward steering ratio profile; in case of backward direction, automatically selecting a backward steering ratio profile expressing the value of the steering ratio in function of the speed of the vehicle and actuating the turn of wheels based on the steering ratio determined by means of backward steering ratio profile.
  • system shown in figure 4 comprises:
  • the detector 20 is configured for detecting if the vehicle is moving in a forward or a backward direction
  • the selector 22 is configured for selecting, in case of forward direction, a forward steering ratio profile expressing the value of the steering ratio in function of the speed of the vehicle and, in case of backward direction, a backward steering ratio profile expressing the value of the steering ratio in function of the speed of the vehicle, the selector 22 is further configured to determine the steering ratio value according to the selected profile and the speed of the vehicle
  • the actuator 11 is configured for actuating the turn of wheels based on the value of the steering ratio determined by the selector 22, wherein the forward steering ratio profile being independent from the backward steering ratio profile.
  • the detection of the movement forward/backward may be obtained in a number of different ways for instance by checking the moving direction, by checking the tractor speed or by using a signal from gear selector 6.
  • the steering ratio profiles may be modified by the user based on a driver' s request; more specifically the user may customize the steering ratio profiles by means of an algorithm that modifies some parameters (slope for instance) of an existing standard pre-defined profile to create a customized profile. Also, the customized profiles may be further modified.
  • the algorithm which performs the calculation of the custom steering profiles is based on:
  • the steering pre-defined profile represented in a bi-axial system wherein the first axis (X axis) represents increasing values of speed and the second axis (Y axis) represents increasing values of steering ratio comprises a first straight line Ri extending between a first point A having coordinates X A and Y A and a second point B having coordinates X B and Y B and a second straight line R 2 extending from point B to a C point having coordinates X c and Y c .
  • the second line R 2 has a steep higher than the steep of the first line Ri . Accordingly, for higher speed the driver has to rotate more the steering wheel for obtaining a desired change of the steering wheel position.
  • Curve defined by points A, B, C represents the pre-defined steering profile.
  • the user may input a desired level of steering ratio (InputHMI) .
  • This value may be introduced by means of a touch screen 7 (figure 1) connected with via CAN bus 8 with the vehicle controller 4.
  • Offset represents the offset of the CAN signal from HMI and Range represents range of the CAN signal from HMI.
  • gain is calculated by a calculating block 24, which communicates with the selector 22 and is configured to receive the InputHMI .
  • the InputHMI signal could variate from a minimum to a maximum value.
  • the Offset is equal to the minimum value of the InputHMI signal [it could be even zero] .
  • a modified line Ri a is calculated having coordinate Y,u and Y BI as defined in the following:
  • YB I YB+ (YC ⁇ YB)*K
  • the value along the first axis (X) remain the same, i.e. X A and X B .
  • a modified line R2 a is calculated having coordinates point Y BI and Y c .
  • the vehicle controller uses the calculated values Y Ai and Y B;L to overwrite the values of the custom steering profile, i.e. the curve Ri .
  • the pre-defined points (A, B, C) of the original profile are not overwritten during this operation .
  • KWP2000 Protocol may be used to write values on the steering controller EEPROM. Of course also different protocols may be used) . Accordingly, the original profile may be retrieved if necessary .
  • the calculated values Y Ai and Y Bi and the modified lines Ri a , R2 a are calculated by the calculating block 24 of the system 10 of figure 4. Following, the calculated values Y Ai and Y Bi are used to overwrite the values of the custom steering profile, thus controlling the steering wheels 12 through the customized profile defined as such . From the above the advantages provided by the present invention are clear ⁇
  • the steering ratio is always selected to be the most suitable as forward driving conditions and backward driving conditions are quite different .
  • the user has moreover the ability to change the steering ratio taking into consideration the specific driving condition, his driving experience and his habits .
  • the steering ratio is thus “tailored" to the driver by the driver himself .

Abstract

Method for controlling the steering ratio of a vehicle provided with wheels comprising the steps of: detecting the movement of a steering wheel or handlebars actuated by the driver to determine a steering request signal and actuating the movement of the wheels based on the steering request signal and based on a steering ratio that is function of the speed of the vehicle. According to the method the following steps are provided: detecting if the vehicle is configured for moving in a forward or a backward direction; in case of forward direction, automatically selecting a forward steering ratio profile linking the steering ratio with the speed of the vehicle and actuating the turn of wheels based on the steering ratio determined by means of the forward steering ratio profile; in case of backward direction, automatically selecting a backward steering ratio profile linking the steering ratio with the speed of the vehicle and actuating the turn of wheels based on the steering ratio determined by means of backward steering ratio profile. The forward steering ratio profile is independent from the backward steering ratio profile. Both profiles are customizable according to operator's request and within specified limits.

Description

"METHOD FOR CONTROLLING THE STEERING RATIO OF A VEHICLE PROVIDED WITH WHEELS BASED ON THE MOVING DIRECTION OF THE VEHICLE AND A
SYSTEM THEREOF"
★★★
Technical field
The present invention relates to a method for controlling the steering ratio of a vehicle provided with wheels based on the moving direction of the vehicle and a system thereof.
Background of the invention
As it is known, steering ratio refers to the ratio between the turns of the steering wheel (in degrees ) or handlebars and the turns of the wheels (in degrees ) . In other words , the steering ratio is the ratio of the number of degrees of turn of the steering wheel to the number of degrees the wheel (s) turn as a result .
A higher steering ratio means that the steering wheel is turned more to get the wheels fully turning, and a lower steering ratio means that the steering wheel is turned less to get the wheels fully turning . In some applications , the steering ratio may be modified in function of the speed of the vehicle so that the steering ratio is increased with the speed of the vehicle to enhance driving safety .
The present invention is focused on the control of the steering wheel ratio that takes into consideration both the speed of the vehicle and the driving direction .
Summary of the invention The present invention relates to a method for controlling the steering ratio of a vehicle provided with wheels and a system thereof, according to the appended claims.
In particular, the method according to an embodiment of the invention comprises the steps of: detecting a steering request signal; actuating the movement of the wheels based on the steering request signal and based on a steering ratio that is function of the speed of the vehicle; detecting if the vehicle is configured for moving in a forward or a backward direction; in case of forward direction, automatically selecting a forward steering ratio profile expressing the value of the steering ratio in function of the speed of the vehicle and actuating the turn of wheels based on the steering ratio determined by means of the forward steering ratio profile; in case of backward direction, automatically selecting a backward steering ratio profile expressing the value of the steering ratio in function of the speed of the vehicle and actuating the turn of wheels based on the steering ratio determined by means of backward steering ratio profile; the forward steering ratio profile being independent from the backward steering ratio profile.
Most preferably a customizing step is provided where the one or both forward or backward profiles may be modified by the user based on a driver's request; more specifically, the user may customize the steering ratio profiles by means of an algorithm that modifies some parameters of an existing standard pre-defined profile to create a customized profile.
The system, according to an embodiment of the present invention, comprises a detector for detecting a steering request signal, and an actuator for actuating the movement of the wheels based on the steering request signal and based on a steering ratio that is function of the speed of the vehicle, wherein The detector is configured for detecting if the vehicle is moving in a forward or a backward direction; the selector is configured for automatically selecting, in case of forward direction, a forward steering ratio profile expressing the value of the steering ratio in function of the speed of the vehicle and, in case of backward direction, a backward steering ratio profile expressing the value of the steering ratio in function of the speed of the vehicle; and the actuator is configured for actuating the turn of wheels based, in case of forward direction, on the steering ratio determined by means of the forward steering ratio profile and, in case of backward direction, on the steering ratio determined by means of backward steering ratio profile; the forward steering ratio profile being independent from the backward steering ratio profile.
Most preferably, in the present system, the one or both forward or backward profiles may be modified by a user based on a driver's request; more specifically, the user may customize the steering ratio profiles by means of an algorithm that modifies some parameters of an existing standard pre-defined profile to create a customized profile .
Accordingly, the steering ratio is always selected to be the most suitable as driving conditions and backward driving conditions are quite different one with respect to the other . The user has moreover the ability to change the steering ratio taking into consideration the specific driving condition, his driving experience and his habits . The steering ratio is thus "tailored" to the driver by the driver himself .
Brief description of the drawings
The invention shall be described with reference to the accompanied drawings that describe a preferred not limiting example of the invention wherein :
Figure 1 represents in a schematic manner the main elements that are involved in the method according to the present invention;
Figure 2 is a diagram showing a phase of the method of the present invention;
Figure 3 is a diagram showing another phase of the method of the present invention; and
Figure 4 schematically shows a system according to the present invention .
Detailed description of the invention
The elements shown in figure 1 are installed on a vehicle provided with wheels , more particularly an agricultural vehicle for instance a tractor . In particular, the vehicle is controlled by a system 10 , schematically shown in figure 4.
The vehicle is provided with at least one couple of steering wheels (not shown) which is actuated by a hydraulic system (of known kind, not shown) that receives working fluid in pressure (oil for instance) from a steering valve 2 whose disposition concurs in regulating the steering angle actuated by the steering wheels .
The steering valve 2 is electrically controlled by a steering valve controller 3 of known kind .
A vehicle controller 4 controls the engine and power transmission of the vehicle and cooperates with the steering valve controller 3.
A steering command signal St from the steering wheel actuated by the driver (or from any suitable control device, handlebars , j oystick, etc . ) may be received by the vehicle controller 4 or alternatively by the steering valve controller 3.
The vehicle controller 4 receives control signal from a gear selector 6 that is provided to implement forward gears , backward gears and neutral and parking positions .
The vehicle controller 4 (or the steering valve controller 3 ) has to translate the steering command signal St in order to provide a suitable signal for the valve controller 3 by using a memorized value of the steering ratio that defines the ratio between the turn of the steering wheel (in degrees ) and the turn of the wheels (in degrees ) .
According to the present invention, two profiles of steering ratio are memorized in the steering valve controller 3 namely : - a forward steering ratio profile (figure 2) expressing the value of the steering ratio in function of the speed of the vehicle ;
- a backward steering ratio profile (figure 3) expressing the value of the steering ratio in function of the speed of the vehicle ;
The forward steering ratio profile and the backward steering ratio profile are independent one with the other. In the example provide the steering ratio profiles present different shapes.
The forward steering ratio profile is automatically selected if the driver intends to use a forward gear and the backward steering ratio profile is automatically selected if the drivers intends to use a backward gear; this automatic selection may be implemented, for instance, by monitoring the position of the gear selector 6. Such selection between the forward steering ratio profile and the backward steering ration profile is performed, as reported in the in figure 4, through a selector 22.
Accordingly, the following steps are implemented according to the method of the present invention: detecting if the vehicle is configured for moving in a forward or a backward direction; in case of forward direction, automatically selecting the forward steering ratio profile expressing the value of the steering ratio in function of the speed of the vehicle and actuating the turn of wheels based on the steering ratio determined by means of the forward steering ratio profile; in case of backward direction, automatically selecting a backward steering ratio profile expressing the value of the steering ratio in function of the speed of the vehicle and actuating the turn of wheels based on the steering ratio determined by means of backward steering ratio profile.
In accordance with the steps of the present method, the system shown in figure 4 comprises:
- a detector 20 for detecting a steering request signal;
- and actuator 11 for actuating the movement of the wheels based on the steering request signal and on a steering ratio, wherein : the detector 20 is configured for detecting if the vehicle is moving in a forward or a backward direction; the selector 22 is configured for selecting, in case of forward direction, a forward steering ratio profile expressing the value of the steering ratio in function of the speed of the vehicle and, in case of backward direction, a backward steering ratio profile expressing the value of the steering ratio in function of the speed of the vehicle, the selector 22 is further configured to determine the steering ratio value according to the selected profile and the speed of the vehicle; the actuator 11 is configured for actuating the turn of wheels based on the value of the steering ratio determined by the selector 22, wherein the forward steering ratio profile being independent from the backward steering ratio profile.
The detection of the movement forward/backward may be obtained in a number of different ways for instance by checking the moving direction, by checking the tractor speed or by using a signal from gear selector 6.
According to an aspect of the present invention the steering ratio profiles may be modified by the user based on a driver' s request; more specifically the user may customize the steering ratio profiles by means of an algorithm that modifies some parameters (slope for instance) of an existing standard pre-defined profile to create a customized profile. Also, the customized profiles may be further modified.
The algorithm which performs the calculation of the custom steering profiles is based on:
- User's request signal;
Pre-defined steering profiles, that are stored into controller 3 or controller 4. In the example provided (Fig 2 or Fig 3) , the steering pre-defined profile represented in a bi-axial system wherein the first axis (X axis) represents increasing values of speed and the second axis (Y axis) represents increasing values of steering ratio comprises a first straight line Ri extending between a first point A having coordinates XA and YA and a second point B having coordinates XB and YB and a second straight line R2 extending from point B to a C point having coordinates Xc and Yc. The second line R2 has a steep higher than the steep of the first line Ri . Accordingly, for higher speed the driver has to rotate more the steering wheel for obtaining a desired change of the steering wheel position.
Curve defined by points A, B, C, represents the pre-defined steering profile.
In order to modify the pre-defined profile (both forward and backward) the user may input a desired level of steering ratio (InputHMI) . This value may be introduced by means of a touch screen 7 (figure 1) connected with via CAN bus 8 with the vehicle controller 4.
Based on the desired level of steering ratio (InputHMI) a gain is calculated as:
K (InputHMI - Offset) /Range
Wherein Offset represents the offset of the CAN signal from HMI and Range represents range of the CAN signal from HMI. With reference to figure 4, such gain is calculated by a calculating block 24, which communicates with the selector 22 and is configured to receive the InputHMI .
The InputHMI signal could variate from a minimum to a maximum value. The Offset is equal to the minimum value of the InputHMI signal [it could be even zero] . The range is the difference between the maximum and the minimum value of the InputHMI signal Range= [MAX- MIN] ) . Range and Offset are fixed (pre-determined values) .
A modified line Ria is calculated having coordinate Y,u and YBI as defined in the following:
YAI=YA+ (YC~YA) *K
YBI=YB+ (YC~YB)*K
The value along the first axis (X) remain the same, i.e. XA and XB.
A modified line R2a is calculated having coordinates point YBI and Yc.
The value along the first axis (X) remain the same, i.e. XB and
Xc.
The vehicle controller uses the calculated values YAi and YB;L to overwrite the values of the custom steering profile, i.e. the curve Ri . The pre-defined points (A, B, C) of the original profile are not overwritten during this operation . (KWP2000 Protocol may be used to write values on the steering controller EEPROM. Of course also different protocols may be used) . Accordingly, the original profile may be retrieved if necessary .
The calculated values YAi and YBi and the modified lines Ria, R2a are calculated by the calculating block 24 of the system 10 of figure 4. Following, the calculated values YAi and YBi are used to overwrite the values of the custom steering profile, thus controlling the steering wheels 12 through the customized profile defined as such . From the above the advantages provided by the present invention are clear ·
Accordingly the steering ratio is always selected to be the most suitable as forward driving conditions and backward driving conditions are quite different .
The user has moreover the ability to change the steering ratio taking into consideration the specific driving condition, his driving experience and his habits . The steering ratio is thus "tailored" to the driver by the driver himself .

Claims

1.- Method for controlling a steering ratio of a vehicle provided with wheels comprising the steps of:
- detecting a steering request signal;
- actuating the movement of the wheels based on the steering request signal and based on a steering ratio that is function of the speed of the vehicle, characterized by comprising: detecting if the vehicle is configured for moving in a forward or a backward direction; in case of forward direction, automatically selecting a forward steering ratio profile expressing the value of the steering ratio in function of the speed of the vehicle and actuating the turn of wheels based on the steering ratio determined by means of the forward steering ratio profile; in case of backward direction, automatically selecting a backward steering ratio profile expressing the value of the steering ratio in function of the speed of the vehicle and actuating the turn of wheels based on the steering ratio determined by means of backward steering ratio profile; the forward steering ratio profile being independent from the backward steering ratio profile.
2.- Method as claimed in claim 1 wherein a customizing step is provided where the one or both the forward and the backward profiles are modified by the user; the user customizes the steering ratio profiles by means of an algorithm that modifies some parameters of an existing standard pre-defined profile to create a customized profile .
3.- Method as claimed in claim 2, wherein each profile represented in a bi-axial system wherein the first axis (X) represents increasing values of speed and the second axis (Y) represents increasing values of steering ratio comprises a first straight line Ri extending between a first point A having coordinates XA and YA and a second point B having coordinates XB and YB and a second straight line R2 extending from point B to a C point having coordinates Xc and Yc; the second line R2 has a steep higher than the steep of the first line Ri .
4.- Method as claimed in claim 3, wherein the customizing operation comprises the following steps:
receiving from a user a desired level of steering ratio
( InputHMI ) ;
calculating a gain K based on the desired level of steering ratio (InputHMI) that has been provided by the driver:
calculating a modified line Rla having coordinate Y,u and YBI as defined in the following:
YAI=YA+ (YC~YA) *K
YBI=YB+ ( YC~YB)*K the value along the first axis (X) remain the same, XA and XB. calculating a modified line R2a having coordinates point YBI and Yc; the value along the first axis (X) remain the same, XB and Xc.
5.- Method as claimed in claim 4, wherein the gain K is calculated as:
K = (InputHMI - Offset) /Range wherein Offset represents the offset of the CAN signal from HMI and Range represents range of the CAN signal from HMI.
6.- System (10) for controlling a steering ratio of a vehicle provided with wheels comprising:
- a detector (20) for detecting a steering request signal;
- and actuator (11) for actuating the movement of the wheels based on the steering request signal and on a steering ratio, wherein : the detector (20) is configured for detecting if the vehicle is moving in a forward or a backward direction; the selector (22) is configured for selecting, in case of forward direction, a forward steering ratio profile expressing the value of the steering ratio in function of the speed of the vehicle and, in case of backward direction, a backward steering ratio profile expressing the value of the steering ratio in function of the speed of the vehicle, the selector (22) is further configured to determine the steering ratio value according to the selected profile and the speed of the vehicle; the actuator (11) is configured for actuating the turn of wheels based on the value of the steering ratio determined by the selector
(22) wherein the forward steering ratio profile being independent from the backward steering ratio profile.
7.- System as claimed in claim 6 configured to allow one or both the forward and the backward profiles to be modified by a user; and to allow the user to customize the steering ratio profiles by means of an algorithm that modifies at least one parameter of an existing standard pre-defined profile to create a customized profile .
8.- System as claimed in claims 6-7, wherein each profile being represented in a bi-axial system wherein the first axis (X) represents values of speed and the second axis (Y) represents values of steering ratio, said each profile comprising a first straight line Ri extending between a first point A having coordinates XA and YA and a second point B having coordinates XB and YB and a second straight line R2 extending from point B to a C point having coordinates Xc and Yc; the second line R2 has a steep higher than the steep of the first line Ri .
9.- System as claimed in claims 7-8 further comprising:
a display configured to transmit a desired level of steering ratio (InputHMI) according to a user input;
a calculating block (24) configured for calculating a gain K based on the desired level of steering ratio (InputHMI) that has been provided by the display:
the calculating block (24) configured for calculating a modified line Ria having coordinate Y^i and YB1 as defined in the following:
YAI=YA+ (Yc A ) *K YBI=YB+ ( YC YB)*K wherein the value along the first axis (X) remain the same, XA and XB; the calculating block (24 ) for calculating a modified line ]¾a having coordinates point YBI and Yc, wherein the value along the first axis (X) remain the same, XB and Xc.
10.- System as claimed in claim 9, wherein the gain K is calculated as:
K = (InputHMI - Offset) /Range wherein Offset represents the offset of the CAN signal from HMI and Range represents range of the CAN signal from HMI.
PCT/EP2019/069651 2018-08-01 2019-07-22 Method for controlling the steering ratio of a vehicle provided with wheels based on the moving direction of the vehicle and a system thereof WO2020025378A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP19742373.4A EP3829957A1 (en) 2018-08-01 2019-07-22 Method for controlling the steering ratio of a vehicle provided with wheels based on the moving direction of the vehicle and a system thereof

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT102018000007743A IT201800007743A1 (en) 2018-08-01 2018-08-01 METHOD FOR CHECKING THE STEERING RATIO OF A VEHICLE FITTED WITH WHEELS AS A FUNCTION OF THE DIRECTION OF MOVEMENT OF THE VEHICLE AND RELATED SYSTEM
IT102018000007743 2018-08-01

Publications (1)

Publication Number Publication Date
WO2020025378A1 true WO2020025378A1 (en) 2020-02-06

Family

ID=63762920

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2019/069651 WO2020025378A1 (en) 2018-08-01 2019-07-22 Method for controlling the steering ratio of a vehicle provided with wheels based on the moving direction of the vehicle and a system thereof

Country Status (3)

Country Link
EP (1) EP3829957A1 (en)
IT (1) IT201800007743A1 (en)
WO (1) WO2020025378A1 (en)

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1371541A1 (en) * 2002-06-13 2003-12-17 Renault s.a.s. Procedure for the determination of the transmission ratio of a vehicle steering system
EP1481875A2 (en) * 2003-05-27 2004-12-01 Audi Ag Automotive steering system with speed-dependent transmission ratio
US20050263338A1 (en) * 2004-05-25 2005-12-01 Marcus Turner Driver selectable steering ratios
DE102004026184A1 (en) * 2004-05-28 2005-12-15 Zf Lenksysteme Gmbh steering system
DE102005056462A1 (en) * 2005-11-26 2007-05-31 Zf Lenksysteme Gmbh Method for opeartion of controllable power assisted or power steering system in motor vehicle, involves functional behavior of controllable steering system which are affected due to interaction of driver with man-machine interface
DE102009002743A1 (en) * 2009-04-30 2010-11-04 Ford Global Technologies, LLC, Dearborn Method for operating an active steering system and active steering system
DE102015203864A1 (en) * 2015-03-04 2016-09-08 Ford Global Technologies, Llc Steering system, motor vehicle with such and method for operating a steering system

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1371541A1 (en) * 2002-06-13 2003-12-17 Renault s.a.s. Procedure for the determination of the transmission ratio of a vehicle steering system
EP1481875A2 (en) * 2003-05-27 2004-12-01 Audi Ag Automotive steering system with speed-dependent transmission ratio
US20050263338A1 (en) * 2004-05-25 2005-12-01 Marcus Turner Driver selectable steering ratios
DE102004026184A1 (en) * 2004-05-28 2005-12-15 Zf Lenksysteme Gmbh steering system
DE102005056462A1 (en) * 2005-11-26 2007-05-31 Zf Lenksysteme Gmbh Method for opeartion of controllable power assisted or power steering system in motor vehicle, involves functional behavior of controllable steering system which are affected due to interaction of driver with man-machine interface
DE102009002743A1 (en) * 2009-04-30 2010-11-04 Ford Global Technologies, LLC, Dearborn Method for operating an active steering system and active steering system
DE102015203864A1 (en) * 2015-03-04 2016-09-08 Ford Global Technologies, Llc Steering system, motor vehicle with such and method for operating a steering system

Also Published As

Publication number Publication date
IT201800007743A1 (en) 2020-02-01
EP3829957A1 (en) 2021-06-09

Similar Documents

Publication Publication Date Title
US6148939A (en) Variable gain steering control system for a work machine
EP2969635B1 (en) Vehicle speed control system and method
EP1550803B1 (en) Prime mover controller of construction machine
EP3569475A1 (en) Steering control unit
US6112839A (en) Automatic remote auxiliary implement control
EP2698304B1 (en) System and method to select a steer mode
JP3068082B2 (en) Steering controller for tracked vehicles
JP4443139B2 (en) Automatic instrument control for spreading materials on work machines
JP2020075697A (en) Machine steering angle control system
JP2018108764A (en) Work vehicle and operation system of work vehicle
US10576981B2 (en) Hand operated auxiliary drive and retard torque control
EP3829957A1 (en) Method for controlling the steering ratio of a vehicle provided with wheels based on the moving direction of the vehicle and a system thereof
US7283900B1 (en) Work vehicle steering system with flow-metering curve selection and associated method
US5636119A (en) Downstream rate limiting method in transmission control
JP6821128B2 (en) Work vehicle
US10167614B2 (en) System and method for controlling hydraulic components of a work vehicle based on stored electro-hydraulic settings
US6041867A (en) Hitch initialization control system
JPH04271704A (en) Controlling apparatus for working vehicle
EP2477862B1 (en) Hydraulic fluid supply systems
WO2018179113A1 (en) Work vehicle
JP2018144684A (en) Work vehicle
EP1555462A1 (en) Method and control device to ensure the correct operation of a range selector in a vehicle transmission
JPH04247131A (en) Hydraulic control device for hydraulic construction equipment
JP2001188612A (en) Switching operation for working vehicle
JP2011140991A (en) Working vehicle

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 19742373

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

ENP Entry into the national phase

Ref document number: 2019742373

Country of ref document: EP

Effective date: 20210301