Method for controlling yaw and transversal dynamics in a road vehicle
First Claim
1. A methodfor controlling yaw dynamics and lateral dynamics in a road vehicle having a first axle and a second axle comprising;
- determining a desired steer angle;
calculating a desired front axle value signal for input to a first controller;
calculating a desired rear axle value signal for input to a second controller;
generating a first drive signal via said first controller for driving an electrically drivable front steer-angle actuator;
generating a second drive signal via said second controller for driving an electrically drivable rear steer-angle actuator;
determining a desired value Svsoll for a lateral force Sv to be built up at said front axle in a control process in a control loop assigned to said front axle;
determining for said desired value Svsoll a desired value δ
vsoll of a front axle steering angle by a relationship of a form
wherein lv being a distance from a center of gravity of said vehicle to said front axle, β
being a sideslip angle, {dot over (Ψ
)} being a yaw velocity, α
vsoll being a desired value of a slip angle at said front axle, and Vx being a longitudinal speed of said road vehicle;
determining a desired value Shsoll for a lateral force Sh to be built up at said rear axle in a control process by a relationship of a form
in a control loop assigned to said rear axle, wherein m being a mass of said vehicle, L being a wheelbase of said vehicle, β
hsoll being a desired slideslip angle of said vehicle in a region of said rear axle, and β
h being a slideslip angle of said vehicle in said region of said rear axle, and β
h being a first controller gain; and
determining for said desired value Shsoll a value of a rear axle steering angle δ
hsoll by a relationship of a form
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Accused Products
Abstract
For the purpose of controlling the yaw dynamics and lateral dynamics in a road vehicle with electrically controlled four-wheel steering, in the case of which the setting of the front axle steer angle δv and of the rear axle steer angle δh is performed by means of mutually decoupled control loops, a desired value δvsoll for the lateral force Sv to be built up at the front axle is determined in the control loop assigned to the front axle and, for this desired value Svsoll, the value of the slip angle, linked to the desired value Svsoll, is determined as desired value αvsoll from an Sv(αv) characteristic representing the dependence of the lateral force Sv, to be built up at the front axle, on the slip angle αv. In the control loop assigned to the rear axle, a desired value Shsoll for the lateral force Sh to be built up at the rear axle is determined in a control process in accordance with a controller law of the form
and, for this desired value Shsoll, the value of the slip angle, linked to the desired value Shsoll, is determined as desired value αhsoll from an Sh(αh) characteristic. These desired values αvsoll and αhsoll are used to determine the desired values δvsoll and δhsoll of the steer angle, taking account of an estimated value of the sideslip angle β at the center of gravity of the vehicle, the position of the center of gravity and measured or estimated values of the yaw velocity {dot over (Ψ)} and of the longitudinal speed vx of the vehicle.
24 Citations
17 Claims
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1. A method
for controlling yaw dynamics and lateral dynamics in a road vehicle having a first axle and a second axle comprising; -
determining a desired steer angle;
calculating a desired front axle value signal for input to a first controller;
calculating a desired rear axle value signal for input to a second controller;
generating a first drive signal via said first controller for driving an electrically drivable front steer-angle actuator;
generating a second drive signal via said second controller for driving an electrically drivable rear steer-angle actuator;
determining a desired value Svsoll for a lateral force Sv to be built up at said front axle in a control process in a control loop assigned to said front axle;
determining for said desired value Svsoll a desired value δ
vsoll of a front axle steering angle by a relationship of a form
wherein lv being a distance from a center of gravity of said vehicle to said front axle, β
being a sideslip angle, {dot over (Ψ
)} being a yaw velocity, α
vsoll being a desired value of a slip angle at said front axle, and Vx being a longitudinal speed of said road vehicle;
determining a desired value Shsoll for a lateral force Sh to be built up at said rear axle in a control process by a relationship of a form
in a control loop assigned to said rear axle, wherein m being a mass of said vehicle, L being a wheelbase of said vehicle, β
hsoll being a desired slideslip angle of said vehicle in a region of said rear axle, and β
h being a slideslip angle of said vehicle in said region of said rear axle, and β
h being a first controller gain; and
determining for said desired value Shsoll a value of a rear axle steering angle δ
hsoll by a relationship of a form - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An apparatus for controlling yaw dynamics and lateral dynamics in a road vehicle having a first axle and a second axle comprising:
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a first steering device for said front axle;
a second steering device for said rear axle;
a first steer angle actuator for said front axle;
a second steer angle actuator for said rear axle; and
at least one lateral acceleration sensor;
wherein a first control mode for a desired value Svsoll of a lateral force at said front axle being obtained from a relationship of a form
and a second control mode for said desired value Svsoll being obtained from a relationship of a form
wherein m being a mass of said vehicle, L being a wheelbase of said vehicle, lh being a distance from a center of gravity of said vehicle to said rear axle, β
being a sideslip angle, ay being a lateral acceleration, Jz being a moment of inertia, and Vx being a longitudinal speed of said road vehicle, {dot over (Ψ
)} being a yaw velocity, {dot over (Ψ
)}soll being a desired yaw velocity, k2 being a second controller gain, and k3 being a third controller gain.
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12. An apparatus for controlling yaw dynamics and lateral dynamics in a road vehicle having a first axle and a second axle comprising:
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a first steering device for said front axle;
a second steering device for said rear axle;
a first steer angle actuator for said front axle;
a second steer angle actuator for said rear axle; and
at least one lateral acceleration sensor;
wherein a first control mode for a desired value Svsoll of a lateral force at said front axle being obtained from a relationship of a form
and a second control mode for said desired value Svsoll being obtained from a relationship of a formwherein m being a mass of said vehicle, L being a wheelbase of said vehicle, lh being a distance from a center of gravity of said vehicle to said rear axle, β
being a sideslip angle, ay being a lateral acceleration, Jz being a moment of inertia, and Vx being a longitudinal speed of said road vehicle, {dot over (Ψ
)} being a yaw velocity, {dot over (Ψ
)}soll being a desired yaw velocity, k2 being a second controller gain, and k3 being a third controller gain;
wherein said first control mode and second control mode being alternatively selectable. - View Dependent Claims (13)
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14. An apparatus for controlling yaw dynamics and lateral dynamics in a road vehicle having a first axle and a second axle comprising:
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a first steering device for said front axle;
a second steering device for said rear axle;
a first steer angle actuator for said front axle;
a second steer angle actuator for said rear axle;
at least one lateral acceleration sensor;
a reference model, wherein said reference model generating desired values for a front axle steer angle δ
v and a rear axle steer angle δ
h; and
wherein an automatic switchover being performed from a control mode in which a desired value Svsoll of a lateral force at said front axle being determined as a function of a system deviation (β
v−
β
vsoll) of a sideslip angle in a region of said front axle, into a control mode in which a desired value Svsoll of a lateral force at said front axle being determined as a function of a system deviation ({dot over (Ψ
)}−
{dot over (Ψ
)}soll) of a yaw velocity when an ability of a tire to transmit lateral force being exhausted, or virtually exhausted, in an extreme range, or a rear axle steer angle actuator has failed.
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15. An apparatus for controlling yaw dynamics and lateral dynamics in a road vehicle having a first axle and a second axle comprising:
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a first steering device for said front axle;
a second steering device for said rear axle;
a first steer angle actuator for said front axle;
a second steer angle actuator for said rear axle; and
at least one lateral acceleration sensor;
wherein a disturbance estimator is provided for at least one of a plurality control loops provided for setting a front axle steer angle δ
y and a rear axle steer angle δ
h; and
wherein a controller and a disturbance estimator which are assigned to the same controlled variable are designed using the same design model.
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16. A method for controlling yaw dynamics and lateral dynamics in a road vehicle having a first axle and a second axle comprising:
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determining a desired steer angle;
calculating a desired front axle value signal for input to a first controller;
calculating a desired rear axle value signal for input to a second controller;
generating a first drive signal via said first controller for driving an electrically drivable front steer-angle actuator;
generating a second drive signal via said second controller for driving an electrically drivable rear steer-angle actuator;
determining a desired value Svsoll for a lateral force Sv to be built up at said front axle in a control process in a control loop assigned to said front axle;
determining a desired value of a slip angle at said front axle α
vsoll from an Sv(α
v) characteristic representing a dependence of said lateral force Sv on a slip angle α
v at said front axle;
determining for said desired value Svsoll a desired value δ
vsoll of a front axle steering angle by a relationship of a form
wherein lv being a distance from a center of gravity of said vehicle to said front axle, β
being a sideslip angle, {dot over (Ψ
)} being a yaw velocity, and Vx being a longitudinal speed of said road vehicle;
determining a desired value Shsoll for a lateral force Sh to be built up at said rear axle in a control process by a relationship of a form
in a control loop assigned to said rear axle, wherein m being a mass of said vehicle, L being a wheelbase of said vehicle, β
hsoll being a desired slideslip angle of said vehicle in a region of said rear axle, and β
h being a slideslip angle of said vehicle in said region of said rear axle, and k1 being a first controller gain;
determining a desired value of a slip angle at said rear axle α
hsoll from an Sh(α
h) characteristic representing a dependence of said lateral force Sh on a slip angle α
h at said rear axle; and
determining for said desired value Shsoll a value of a rear axle steering angle δ
hsoll by a relationship of a formwherein said front steer-angle actuator is individually assigned to said front axle and said rear steer-angle actuator is individually assigned to said rear axle;
wherein said control loop assigned to said front axle and said control loop assigned to said rear axle are decoupled from one another;
wherein said desired front axle value signal and said desired rear axle value signal are generated by a reference model, said reference model being implemented by an electronic computer from a processing of at least one output signal, representing a driver'"'"'s wish, from a steering element position sensor, and of a sensor output signal characteristic of an operating state of said vehicle.
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17. An apparatus for controlling yaw dynamics and lateral dynamics in a road vehicle having a first axle and a second axle comprising:
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a first steering device for said front axle;
a second steering device for said rear axle;
a first steer angle actuator for said front axle;
a second steer angle actuator for said rear axle; and
at least one lateral acceleration sensor;
wherein a desired value Svsoll for a lateral force Sv to be built up at said front axle being determined in a control process in a first control loop assigned to said front axle;
wherein a desired value of a slip angle at said front axle avsoll being determined from an Sv(α
v) characteristic representing a dependence of said lateral force Sv on a slip angle α
v at said front axle;
wherein for said desired value Svsoll a desired value δ
vsoll of a front axle steering angle being determined by a relationship of a form
wherein lv being a distance from a center of gravity of said vehicle to said front axle, β
being a sideslip angle, {dot over (Ψ
)} being a yaw velocity, and Vx being a longitudinal speed of said road vehicle;
wherein a desired value Shsoll for a lateral force Sh to be built up at said rear axle being obtained from a relationship of a form
in a second control loop assigned to said rear axle, wherein β
hsoll being a desired slideslip angle of said vehicle in a region of said rear axle, and β
h being a slideslip angle of said vehicle in said region of said rear axle, and k1 being a first controller gain;
wherein a desired value of a slip angle at said rear axle α
hsoll being determined from an Sh(α
h) characteristic representing a dependence of said lateral force Sh on a slip angle α
h at said rear axle;
wherein for said desired value Shsoll a value of a rear axle steering angle δ
hsoll being determined by a relationship of a formwherein said first steer-angle actuator is individually assigned to said front axle and said second steer-angle actuator is individually assigned to said rear axle;
wherein said first control loop assigned to said front axle and said second control loop assigned to said rear axle are decoupled from one another;
wherein a desired front axle value signal and a desired rear axle value signal are generated by a reference model, said reference model being implemented by an electronic computer from a processing of at least one output signal, representing a driver'"'"'s wish, from a steering element position sensor, and of a sensor output signal characteristic of an operating state of said vehicle.
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Specification