초록 ▼

A method and system are provided for generating engine attachment control boundary conditions and corresponding control signals for an exhaust system laboratory test fixture which accurately reproduce both the dynamic behavior of a vehicle powertrain during operation, and the dynamic behavior of the

A method and system are provided for generating engine attachment control boundary conditions and corresponding control signals for an exhaust system laboratory test fixture which accurately reproduce both the dynamic behavior of a vehicle powertrain during operation, and the dynamic behavior of the vehicle frame during operation in the area where the exhaust system is attached to the vehicle frame. Road load data is collected in vertical, lateral, and longitudinal directions on the vehicle frame during vehicle operation at each of the locations where the exhaust system attaches. In addition, temperature and thermal cycling data are also collected during operation of the vehicle. The road load data is used to determine a best fit rigid body model. Accelerometer locations and directions are determined from statistical analysis and ranking to find the measures best fitting the determined rigid body. This information is then used to generate the test boundary conditions and control signals to be input to the test fixture. Thermal profiles are generated based on the collected temperature data to form input control signals to control heating of the exhaust system during testing. The generated thermal profiles allow simulation of real-world thermal stresses caused by hot exhaust gases.

대표청구항 ▼

[ What is claimed is:] [1.]1. A method for generating engine attachment control boundary conditions and corresponding actuator control signals for an exhaust system laboratory test fixture comprising:collecting actual acceleration road load data for both a vehicle frame at each of the locations wher

[ What is claimed is:] [1.]1. A method for generating engine attachment control boundary conditions and corresponding actuator control signals for an exhaust system laboratory test fixture comprising:collecting actual acceleration road load data for both a vehicle frame at each of the locations where the exhaust system attaches to the vehicle frame, and relative displacement or acceleration data for a vehicle powertrain relative to the vehicle frame;obtaining vehicle coordinates for test fixture accelerometer locations by identifying the vehicle coordinates that define the locations and directions on the vehicle frame at which the actual acceleration road load data was collected;performing a rigid body analysis by applying the actual acceleration road load data and the identified vehicle coordinates in a statistical multiple linear regression analysis to define a rigid body that fits the road load acceleration data at the vehicle coordinates;verifying the fit of the defined rigid body;determining boundary conditions on the test fixture by selecting a set of accelerometer locations and directions which best fit the defined rigid body; anddetermining the actuator control signals based on the determined boundary conditions in combination with a first control model arranged to control frame motion relative to a test floor.