A method is provided for steering control of a vehicle by using lateral velocity of two know points (or lateral velocity of one known point and yaw rate), longitudinal velocity and steer angle information. These factors are used to calculate a target steer angle based on the track angle based on yaw decomposition to thus adjust a current steer angle of the vehicle based on the target steer angle.

A method is provided for steering control of a vehicle by using lateral velocity of two know points (or lateral velocity of one known point and yaw rate), longitudinal velocity and steer angle information. These factors are used to calculate a target steer angle based on the track angle based on yaw decomposition to thus adjust a current steer angle of the vehicle based on the target steer angle.

Methods, systems, and vehicles are provided for facilitating control of steering in autonomous vehicles. In accordance with one embodiment, an autonomous vehicle includes one or more wheel sensors and a processor. The one or more sensors are configured to obtain sensor data pertaining to a side slip of the autonomous vehicle. A dual mandate of desired path tracking & stability is achieved by using a combination of two linear controllers. The first controlled facilitates tracking whereas the second controller facilitates vehicle stability. When the stability event occurs a gradual shift towards the second controller occurs and with recovery from stability event gradual shift towards the first controller. Mimicking of driver behavior by changing the desired trajectory and dynamic control gain adaptation are also added.

Methods, systems, and vehicles are provided for facilitating control of steering in autonomous vehicles. In accordance with one embodiment, an autonomous vehicle includes one or more wheel sensors and a processor. The one or more sensors are configured to obtain sensor data pertaining to a side slip of the autonomous vehicle. A dual mandate of desired path tracking & stability is achieved by using a combination of two linear controllers. The first controlled facilitates tracking whereas the second controller facilitates vehicle stability. When the stability event occurs a gradual shift towards the second controller occurs and with recovery from stability event gradual shift towards the first controller. Mimicking of driver behavior by changing the desired trajectory and dynamic control gain adaptation are also added.

A method is for determining a side slip angle during the cornering of a vehicle. The following variables are recorded and interlinked via a mathematical vehicle model with assumptions of the linear single-track model: a predetermined or measured position of the center of gravity between a front and rear axle, the current vehicle velocity, a current vehicle cornering motion variable, the current steering angle on the front axle. To simplify the determination of the side slip angle, it is determined under the assumption that the difference between the side slip angle and the Ackermann side slip angle is proportional to the difference between the Ackermann angle and the steering angle. The actual side slip angle is deduced from the relationship of the measured steering angle and the Ackermann angle based on the proportionality relationship of the Ackermann side slip angle theoretically present when driving through the same curve without slip.

The present invention relates to a method for estimating the side slip angle (β.sup.stim) of a four-wheeled vehicle, comprising: —detecting signals representing the vehicle longitudinal acceleration (Ax), lateral acceleration (Ay), vertical acceleration (Az), yaw rate (formula I), roll rate (formula II), wheels speeds (V.sub.FL, V.sub.FR, V.sub.RL, V.sub.RR); —pre-treating (1) said signals in order to correct measurement errors and/or noises, so to obtain corrected measurements of at least the longitudinal acceleration (a.sub.x), the lateral acceleration (a.sub.y), the yaw rate (formula I) and the wheels speeds (ν.sub.FL, ν.sub.FR, ν.sub.RL, ν.sub.RR), —determining (2) an estimated vehicle longitudinal speed (V.sub.x.sup.stim) on the basis of at least one of the corrected measurements of the wheel speeds (ν.sub.FL, ν.sub.FR, ν.sub.RL, ν.sub.RR); —determining a yaw acceleration (formula III) from the signal representing the yaw rate (formula I); —solving (25) a time-depending parametrical non-linear filter, such as a Kalman filter or a Luenberger filter, describing the vehicle longitudinal and lateral speeds (formula IV) and longitudinal and lateral accelerations (formula V) as a function of the corrected measurements of the longitudinal acceleration (a.sub.x), of the lateral acceleration (a.sub.y), of the yaw rate (formula I) and the estimated vehicle longitudinal speed (V.sub.x.sup.stim) and of a filter parameter (F) depending from depending from at least one of the vehicle yaw acceleration (formula III), yaw rate (formula I) and lateral acceleration (ay) which adds a negative component to the lateral acceleration (formula VI) determined by the filter itself, said filter parameter (F) being selected such that said negative component reaches a maximum value when it is determined that the vehicle is moving straight on the basis of said at least one of the vehicle yaw acceleration (formula III), yaw rate (formula I) and lateral acceleration (ay); —determining the vehicle estimated side slip angle (β.sup.stim) from said longitudinal and lateral vehicle speeds (formula IV) determined by solving the non-linear filter. The present invention further relates to a computer program implementing said method, a control unit having said computer program loaded, and a vehicle comprising said control unit.

The present invention relates to a method for estimating the side slip angle (β.sup.stim) of a four-wheeled vehicle, comprising: —detecting signals representing the vehicle longitudinal acceleration (Ax), lateral acceleration (Ay), vertical acceleration (Az), yaw rate (formula I), roll rate (formula II), wheels speeds (V.sub.FL, V.sub.FR, V.sub.RL, V.sub.RR); —pre-treating (1) said signals in order to correct measurement errors and/or noises, so to obtain corrected measurements of at least the longitudinal acceleration (a.sub.x), the lateral acceleration (a.sub.y), the yaw rate (formula I) and the wheels speeds (ν.sub.FL, ν.sub.FR, ν.sub.RL, ν.sub.RR), —determining (2) an estimated vehicle longitudinal speed (V.sub.x.sup.stim) on the basis of at least one of the corrected measurements of the wheel speeds (ν.sub.FL, ν.sub.FR, ν.sub.RL, ν.sub.RR); —determining a yaw acceleration (formula III) from the signal representing the yaw rate (formula I); —solving (25) a time-depending parametrical non-linear filter, such as a Kalman filter or a Luenberger filter, describing the vehicle longitudinal and lateral speeds (formula IV) and longitudinal and lateral accelerations (formula V) as a function of the corrected measurements of the longitudinal acceleration (a.sub.x), of the lateral acceleration (a.sub.y), of the yaw rate (formula I) and the estimated vehicle longitudinal speed (V.sub.x.sup.stim) and of a filter parameter (F) depending from depending from at least one of the vehicle yaw acceleration (formula III), yaw rate (formula I) and lateral acceleration (ay) which adds a negative component to the lateral acceleration (formula VI) determined by the filter itself, said filter parameter (F) being selected such that said negative component reaches a maximum value when it is determined that the vehicle is moving straight on the basis of said at least one of the vehicle yaw acceleration (formula III), yaw rate (formula I) and lateral acceleration (ay); —determining the vehicle estimated side slip angle (β.sup.stim) from said longitudinal and lateral vehicle speeds (formula IV) determined by solving the non-linear filter. The present invention further relates to a computer program implementing said method, a control unit having said computer program loaded, and a vehicle comprising said control unit.

Method for the estimation of at least a variable (β; ν.sub.x, ν.sub.y; ψ, μ) affecting a vehicle dynamics (10), including measuring dynamic variables (MQ) of the vehicle (10) during its motion, calculating in real time an estimate (Formula (I)) of said variable (β; ν.sub.x, ν.sub.y; ψ, μ), on the basis of said measured dynamic variables (MQ), The method includes: calculating (230) said estimate of said at least a variable (β; ν.sub.x, ν.sub.y; ψ, μ) by an estimation procedure (DVS.sub.β; DVS.sub.βν; DVS.sub.βνμ) comprising taking in account a set of dynamic variables (MQ) measured during the motion of the vehicle (10) over respective time intervals (n.sub.y, n.sub.w, n.sub.ψ, n.sub.x, n.sub.α) and applying on said set of measured dynamic variables (MQ) at least an optimal nonlinear regression function (ƒ*.sub.β; ƒ*.sub.x, ƒ*.sub.y; ƒ*.sub.β1, ƒ*.sub.β2, ƒ*.sub.ψ1, ƒ.sub.ψ2) calculated with respect to said variable (β; ν.sub.x, ν.sub.y; ψ, μ) to estimate to obtain said estimate of said variable (β; ν.sub.x, ν.sub.y; ψ, μ), said optimal non linear regression function (ƒ*.sub.β; ƒ*.sub.x, ƒ*.sub.y; ƒ*.sub.β1, ƒ*.sub.β2, ƒ*.sub.ψ1, ƒ*.sub.ψ2) being obtained by an optimal calculation procedure (220) including: on the basis of an acquired set of reference data (D.sub.d) and of said set of dynamic variables (MQ) measured during the motion of the vehicle (10), finding, for a desired accuracy level (ε), a regression function (ƒ*.sub.β; ƒ*.sub.x, ƒ*.sub.y; ƒ*.sub.β1, ƒ*.sub.β2, ƒ*.sub.ψ1, ƒ*.sub.ψ2) giving an estimation error lower or equal than said desired accuracy level (ε) in a given set of operative conditions (OC), said acquired set of reference data (D.sub.d) being obtained by acquiring (210) in said given set of operative conditions (OC) a set of reference data (D.sub.d) of variables including variables corresponding to said measured dynamic variables (MQ) of the vehicle (10) and a lateral (v.sub.y) and a longitudinal velocity (v.sub.x) of the vehicle (10).

Method for the estimation of at least a variable (β; ν.sub.x, ν.sub.y; ψ, μ) affecting a vehicle dynamics (10), including measuring dynamic variables (MQ) of the vehicle (10) during its motion, calculating in real time an estimate (Formula (I)) of said variable (β; ν.sub.x, ν.sub.y; ψ, μ), on the basis of said measured dynamic variables (MQ), The method includes: calculating (230) said estimate of said at least a variable (β; ν.sub.x, ν.sub.y; ψ, μ) by an estimation procedure (DVS.sub.β; DVS.sub.βν; DVS.sub.βνμ) comprising taking in account a set of dynamic variables (MQ) measured during the motion of the vehicle (10) over respective time intervals (n.sub.y, n.sub.w, n.sub.ψ, n.sub.x, n.sub.α) and applying on said set of measured dynamic variables (MQ) at least an optimal nonlinear regression function (ƒ*.sub.β; ƒ*.sub.x, ƒ*.sub.y; ƒ*.sub.β1, ƒ*.sub.β2, ƒ*.sub.ψ1, ƒ.sub.ψ2) calculated with respect to said variable (β; ν.sub.x, ν.sub.y; ψ, μ) to estimate to obtain said estimate of said variable (β; ν.sub.x, ν.sub.y; ψ, μ), said optimal non linear regression function (ƒ*.sub.β; ƒ*.sub.x, ƒ*.sub.y; ƒ*.sub.β1, ƒ*.sub.β2, ƒ*.sub.ψ1, ƒ*.sub.ψ2) being obtained by an optimal calculation procedure (220) including: on the basis of an acquired set of reference data (D.sub.d) and of said set of dynamic variables (MQ) measured during the motion of the vehicle (10), finding, for a desired accuracy level (ε), a regression function (ƒ*.sub.β; ƒ*.sub.x, ƒ*.sub.y; ƒ*.sub.β1, ƒ*.sub.β2, ƒ*.sub.ψ1, ƒ*.sub.ψ2) giving an estimation error lower or equal than said desired accuracy level (ε) in a given set of operative conditions (OC), said acquired set of reference data (D.sub.d) being obtained by acquiring (210) in said given set of operative conditions (OC) a set of reference data (D.sub.d) of variables including variables corresponding to said measured dynamic variables (MQ) of the vehicle (10) and a lateral (v.sub.y) and a longitudinal velocity (v.sub.x) of the vehicle (10).

A method for stabilizing a vehicle (100) in which the vehicle (100) has a roll stabilizer (120), which is designed to stabilize a first axle (101) and a second axle (102) as a function of a roll torque distribution between the first axle (101) and the second axle (102). The method comprises a step of determining a sideslip angle index from a difference between a transverse acceleration calculated from a yaw rate of the vehicle (100) and a speed of the vehicle (100), and a detected transverse acceleration of the vehicle (100). The sideslip angle index is related to a sideslip angle of the vehicle (100). The method also comprises a step of generating a control signal (160) using the sideslip angle index. The control signal (160) is suitable for adjusting the roll torque distribution of the roll stabilizer (120) as a function of the determined sideslip angle index.