Method and steering assistance system for detecting the contact state of at least one hand of a driver on the steering handle of a vehicle

Abstract

Method for detecting the contact state of at least one hand of a driver on the steering handle of a vehicle, characterized by the steps of 1. the steering movement of the steering handle is detected by means of at least one torque sensor and at least one angle sensor, 2. the free steering movement of the steering handle is modeled using experimental measurement data, taking non-linear friction effects into account, 3. the driver steering torque is determined as a state by means of the state observer, wherein the state is a disturbance variable, 4. a state observer is used to estimate the driver steering torque and the contact state between the hands and the steering handle is detected by means of the estimated driver steering torque, wherein the state observer is a disturbance variable observer.

Claims

[1] Method for detecting the contact state of at least one hand of a driver on the steering handle of a vehicle, characterized by the steps 1. the steering movement of the steering handle is detected by means of at least one torque sensor and at least one angle sensor, 2. the free steering movement of the steering handle is modelled using experimental measurement data, taking non-linear friction effects into account, 3. the driver steering torque is determined as a state by means of the state observer, whereby the state is a disturbance variable, 4. that a state observer is used to estimate the driver steering torque and the contact state between the hands and the steering handle is detected by means of the estimated driver steering torque, wherein the state observer is a disturbance observer. [2] Method according to claim 1, characterized in that the dynamic model which describes the free steering movement of the steering handle is a non-linear differential equation. [3] Method according to claim 1 and 2, characterized in that the non-linear dynamic model of the steering handle is transformed into a linear model by numerical treatment. [4] Method according to one of the preceding claims, characterized in that the detection of the hand-on / off state is carried out by a comparison of the moving average of the amount of the estimated driver steering torque in a predefined time window τ with a predefined threshold value ε1 and a comparison of the moving average of the amount of the quotient |x2 / M s | with a predefined threshold ε2. [5] Method according to one of the preceding claims, characterized in that at a zero crossing of the measured torque M sthe modified quotient |x2 / M̂ s | to calculate the moving average of the quotient |x2 / M s | is used. [6] Method according to one of the preceding claims, characterized in that the estimated driver steering torque in a predefined time window τ is smaller than a predefined threshold value ε1 and the quotient |x2 / M s |, if applicable |x2 / M̂ s |, is greater than a predefined threshold ε2, an active detection of the hand-off state is performed. [7] Steering assistance system for detecting the contact state of at least one hand of a driver on the steering handle of a vehicle, characterized by , that the steering assistance system comprises a steering handle (1), a steering rod (2), means for detecting and determining steering movement signals (3, 4), means for filtering the steering signals (5, 6), means for forming mathematical derivatives (7), an observer for the driving steering torque (8) and a hand-off detector (9).

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