Inertial Sensor Offset Calibration for Vehicle Stability Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Vehicle stability control systems face errors due to inaccurate mounting of inertial sensors, leading to erroneous information transfer to the Electronic Control Unit (ECU), which can result in unintended interventions and reduced sensitivity.
Innovation Solution
A method to quantify and store mounting errors in a non-volatile memory for use by the VSC control algorithm, involving multiple accelerometers to measure true lateral and longitudinal acceleration during manufacturing, and subsequent calibration on a test stand and after vehicle installation, to correct for cross-axis errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If inertial sensors are mounted in the vehicle, then vehicle stability control can be achieved, but mounting errors cause cross-axis measurement errors that lead to erroneous information transfer to the ECU
Solution Approach 1:
The patent applies preliminary action by measuring and storing mounting offset errors during the manufacturing and assembly process, before the vehicle is put into service. The method quantifies the actual mounting orientation of inertial sensors relative to vehicle spatial axes and stores these offset values in non-volatile memory. During vehicle operation, the ECU uses these pre-stored offset values to correct sensor measurements, thereby eliminating cross-axis measurement errors that would otherwise lead to erroneous stability control interventions.
2Reliability
If activation thresholds for VSC are increased to prevent unintended interventions, then false triggering is reduced, but sensitivity of the ECU is reduced
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the activation thresholds for VSC based on the measured mounting offset errors. Instead of using fixed high thresholds that reduce sensitivity, the system modifies the threshold parameters according to the actual sensor mounting orientation. This allows the ECU to maintain high sensitivity for detecting genuine stability issues while compensating for mounting errors through parameter adjustment, thereby preventing false triggering without sacrificing detection capability.
3Manufacturing precision
If multiple accelerometers are used to measure true lateral and longitudinal acceleration, then manufacturing precision can be improved, but device complexity increases
Solution Approach 1:
The patent applies mechanics substitution by replacing the need for mechanically precise accelerometer mounting with an electronic correction system. Instead of requiring multiple accelerometers to be mechanically aligned with extreme precision during manufacturing, the system uses a single or fewer accelerometers combined with electronic offset compensation. The mounting offset errors are measured and stored, then used by the ECU to computationally correct the measurements, thereby achieving high manufacturing precision without the complexity of multiple precisely-aligned sensors.
Data Source
AI summary
A method for calibration of motion sensors included in a vehicle electronic brake control system includes measuring sensor offset errors at different points in the assembly of the system and the vehicle and then combining the offset errors to obtain net offset errors for use with an electronic brake system.