Orientation model for a sensor system
A sensor system for arrangement in a vehicle includes a plurality of sensor elements, a satellite navigation system, and a signal processing device. The signal processing device calculates and/or uses a first group of data of physical variables, whose values relate to a vehicle coordinate system, and calculates and/or uses a second group of data of physical variables, whose values relate to a world coordinate system, for describing the orientation and/or dynamic variables of the vehicle in the world.
1. A sensor system for arrangement in a vehicle, the sensor system comprising:
a plurality of sensor elements configured to detect at least partly different primary measured variables and use at least partially different measurement principles,
a satellite navigation system, and
a signal processing device,
the signal processing device is configured to evaluate that it evaluates the sensor signals of the sensor elements and the output signals of the satellite navigation system jointly at least partially directly or indirectly,
the signal processing device calculates and/or uses a first group of data of physical variables, whose values relate to a vehicle coordinate system, and wherein the signal processing device calculates and/or uses a second group of data of physical variables, whose values relate to a world coordinate system, wherein this world coordinate system is suitable at least for describing the orientation and/or dynamic variables of the vehicle in the world,
wherein the vehicle coordinate system is defined as having a longitudinal axis of the vehicle, a transverse axis of the vehicle and a vertical axis of the vehicle,
wherein the world coordinate system defines an orientation and/or dynamic variables of the vehicle in the world.
the sensor system has an orientation model unit, with which the orientation angle between the vehicle coordinate system and the world coordinate system is calculated.
2. The sensor system as claimed in claim 1 , wherein the orientation angle between the vehicle coordinate system and the world coordinate system is calculated in the orientation model unit at least on the basis of the following variables:
the velocity with respect to the vehicle coordinate system,
the velocity with respect to the world coordinate system, and
in particular the steering angle.
3. The sensor system as claimed in claim 1 , wherein the signal processing device comprises a sensor fusion module, which has a fusion filter, which, over the course of the common evaluation of at least the sensor signals and/or signals of the sensor elements derived therefrom, provides a defined fusion data set, wherein this fusion data set has in each case data relating to defined physical variables, wherein the fusion data set relating to at least one physical variable comprises a value of this physical variable and information on the data quality thereof, and
the fusion data set comprises, as the value of the at least one physical variable, a relative value, in particular an offset value and/or change value and/or correction value and/or error value.
4. The sensor system as claimed in claim 3 , wherein the relative values of the respective physical variables of the fusion data set are correction values, and
the information on the data quality of the values of physical variables are variances.
5. The sensor system as claimed in claim 1 , wherein the sensor system has an inertial sensor arrangement, comprising at least one acceleration sensor element and at least one rotation rate sensor element, and the sensor fusion module comprises a strapdown algorithm unit to process at least the sensor signals of the inertial sensor arrangement to provide navigation data and/or driving dynamics data, based on the vehicle in which the sensor system is arranged.
6. The sensor system as claimed in claim 2 , wherein the orientation angle between the vehicle coordinate system and the world coordinate system is calculated in the orientation model unit, in addition at least on the basis of one or more of the following variables:
orientation information of the vehicle based on the world coordinate system,
some or all of the correction values and/or variances of the fusion filter and/or
the acceleration of the vehicle in relation to the vehicle coordinate system and/or the world coordinate system.
7. The sensor system as claimed in claim 5 , wherein the orientation model unit uses some or all of the output data and/or output signals of the strapdown algorithm unit for the calculation.
8. The sensor system as claimed in claim 3 , wherein the orientation model unit is configured to calculate and provide information on data quality of the variance of the orientation angle, wherein the orientation model unit provides the orientation angle between the vehicle coordinate system and the world coordinate system and the information on the data quality of this variable to the fusion filter, and the fusion filter uses this orientation angle in its calculations.
9. The sensor system as claimed in claim 3 , wherein the orientation model unit is configured to calculate and provide information on the data quality of the variance of the orientation angle,
wherein the orientation angle is provided to the strapdown algorithm unit and/or is overwritten therein by the output value of the orientation model unit, and the information on the data quality of this variable is provided to the fusion filter and/or is overwritten therein by the output value of the orientation model unit.
10. The sensor system as claimed in claim 3 , wherein the sensor system comprises a satellite navigation system, which is configured to detect the distance data in each case between the assigned satellite and the vehicle or a variable dependent thereon and velocity information data in each case between the assigned satellite and the vehicle or a variable dependent thereon and provides these data or variables to the fusion filter, and the fusion filter uses these variables in its calculations.
11. The sensor system as claimed in claim 1 , wherein the orientation model unit is configured to take into consideration at least one or more or all of the following model assumptions in its calculations:
a total velocity of the vehicle with respect to at least its longitudinal and/or transverse axis is greater than zero,
an average velocity of the vehicle in the direction of/along its vertical axis is equal to zero,
there is no tire slip and/or the vehicle substantially follows wheel steering angles without any deviations.
12. The sensor system as claimed in claim 2 , wherein the orientation angle between a vehicle coordinate system and a world coordinate system is calculated in an orientation model unit, on the basis of one or more of the following variables:
a wheel rotation speeds of wheel rotation speed sensor elements of the vehicle and the steering angle or the calculated wheel angle, wherein a rotation rate of the vehicle about its vertical axis is determined by the wheel rotation speeds and the steering angle or the wheel angles by means of difference formation and/or the rotation rate of the vehicle about its vertical axis on the basis of the vehicle coordinate system, provided by the strapdown algorithm unit.