GNSS-INS Vehicle Stability Control for Gravity Orientation
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Solution Overview
Problem
Conventional vehicle dynamics control systems fail to accurately measure driving stability in situations with large sideslip angles, loss of ground contact, and steep inclinations, as they cannot determine the direction of gravity, leading to measurement errors and loss of orientation, which compromises safety in critical driving conditions.
Innovation Solution
The integration of Global Navigation Satellite Systems (GNSS) and Inertial Measurement Units (INS) allows for three-dimensional, absolute measurements of a vehicle's position and orientation in earth coordinates, enabling the continuous detection of gravity direction and movement, even when the vehicle is not in contact with the ground, and using this data to enhance driving dynamics control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If classic vehicle dynamics control systems use wheel rotation and slip to determine driving speed, then the system works under normal ground contact conditions, but the system loses measurement capability when wheels lift off the ground or ground contact is insufficient
Solution Approach 1:
The patent combines GNSS (Global Navigation Satellite System) and INS (Inertial Navigation System) to create an integrated navigation system that provides continuous position, velocity, and orientation measurements regardless of wheel-ground contact status. This merging of independent navigation systems ensures reliable measurement even when classic wheel-based sensors fail.
Solution Approach 2:
The patent introduces GNSS and INS as intermediary systems that indirectly measure vehicle motion through satellite positioning and inertial sensors, bypassing the need for direct wheel-ground contact measurement. These intermediaries provide measurement data when traditional direct measurement methods fail.
2Measurement precision
If vehicle dynamics control systems measure only in the vehicle's local coordinate system, then the measurement system remains simple, but the system loses orientation accuracy when the vehicle is heavily inclined or experiences large sideslip angles
Solution Approach 1:
The patent transforms the measurement framework from a two-dimensional vehicle-local coordinate system to a three-dimensional Earth-fixed coordinate system. This dimensional change allows the system to accurately capture vehicle orientation, inclination, and sideslip by referencing absolute Earth coordinates rather than relative vehicle coordinates.
Solution Approach 2:
The GNSS/INS navigation system performs multiple functions simultaneously: it provides position, velocity, orientation, and gravity direction measurements. This multi-functionality allows a single system to handle various measurement needs (orientation, inclination, sideslip angle) that would otherwise require separate specialized sensors.
3Measurement precision
If conventional acceleration sensors are permanently connected to the vehicle, then the measurement system remains simple, but the measurement level deviates from the road surface when the vehicle inclines sharply, causing measurement errors
Solution Approach 1:
The patent replaces the mechanical acceleration sensing system (sensors fixed to the vehicle chassis) with a navigation-based measurement system using GNSS/INS. This substitution eliminates the mechanical coupling between the sensor and vehicle inclination, allowing accurate acceleration measurement regardless of vehicle orientation relative to the road surface.
Solution Approach 2:
The patent changes the reference frame parameters from vehicle-fixed coordinates to Earth-fixed coordinates. By transforming acceleration measurements into the Earth-fixed reference frame, the system compensates for vehicle inclination and maintains measurement accuracy across varying road conditions and vehicle attitudes.
4Reliability
If the vehicle loses ground contact during critical driving situations, then wheel-based braking intervention options are reduced, but the control system should maintain orientation awareness to enable dynamic control after regaining ground contact
Solution Approach 1:
The patent implements preliminary action by continuously maintaining orientation and position awareness through GNSS/INS even during wheel lift-off events. This ensures that when the vehicle regains ground contact, the control system immediately has accurate orientation information available to resume dynamic control without interruption or loss of situational awareness.
Data Source
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AI summary
The invention relates to a method for controlling the driving dynamics of a vehicle, especially of a single-track or dual-track land craft. The driving dynamics of the vehicle are controlled by way of brake and/or engine intervention, notably depending on a change of motion of the vehicle in the three-dimensional space and relative to the earth coordinate system and depending on the effective direction of gravity or the earth's gravitational pull. According to said method, the location or orientation and the position of the vehicle in three-dimensional space and relative to the earth coordinate system is determined by means of a satellite navigation system (GNSS) which comprises a receiver, mounted on/in the vehicle, having at least three antennas for reception of satellite navigation signals and an inertial measuring system (INS), mounted on/in the vehicle, for measuring all changes in motion, position and/or location of the vehicle.