Heavy-Duty Engine In-Chassis Testing With Drivetrain Loss Correction
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Solution Overview
Problem
Conducting regulatory emissions compliance testing for heavy-duty engines installed in vehicles is challenging due to the difficulty in removing engines from the vehicle chassis and accurately simulating vehicle-based sensor signals, leading to limited and cumbersome testing methods that do not represent real-world usage.
Innovation Solution
A testing apparatus and method using external drive-axle dynamometers and a robotic driver to perform emissions and fuel consumption testing while the engine remains in the vehicle, accounting for drivetrain losses by creating a corrected engine torque map and controlling engine speed and throttle position to achieve equivalent laboratory-based test results.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If engine removal from vehicle chassis is performed for regulatory testing, then testing accuracy is improved, but testing complexity and time consumption increase significantly
Solution Approach 1:
The patent creates a virtual copy of the vehicle chassis environment through software simulation. The chassis control unit replicates the electrical and operational characteristics of the actual chassis, allowing the engine to be tested in isolation while receiving simulated signals that mirror real-world chassis behavior. This copying approach eliminates the need for physical engine removal while preserving testing accuracy.
Solution Approach 2:
The patent introduces a chassis control unit as an intermediary between the engine controller and the testing apparatus. This intermediary component receives commands from the testing system and generates appropriate simulated chassis sensor signals, mediating the interaction between the isolated engine and the test environment without requiring physical connection to an actual vehicle chassis.
2Measurement precision
If engine removal from vehicle chassis is performed for regulatory testing, then testing accuracy is improved, but testing time increases
Solution Approach 1:
The patent performs preliminary configuration of the chassis control unit with pre-programmed vehicle-specific parameters and sensor signal characteristics before the actual engine testing begins. This preliminary setup includes storing chassis electrical characteristics, sensor response patterns, and operational parameters that will be automatically applied during testing, eliminating the need for time-consuming manual configuration during each test procedure.
Solution Approach 2:
By creating a virtual chassis environment through software copying, the system eliminates the time-consuming physical processes of engine removal, installation, and connection that would otherwise be required. The digital replica provides instant access to chassis characteristics without mechanical intervention.
3Ease of operation
If virtual chassis environment with simulated sensor signals is used, then ease of operation is improved, but measurement precision may deteriorate
Solution Approach 1:
The chassis control unit implements feedback mechanisms that continuously monitor the engine's responses to simulated chassis signals and adjust the virtual environment parameters accordingly. This feedback loop ensures that the simulated signals accurately reflect the engine's actual behavior in a real chassis, maintaining measurement precision while preserving ease of operation.
Solution Approach 2:
The virtual chassis environment is designed to be dynamic rather than static, allowing real-time adjustment of sensor signal characteristics based on engine operating conditions. The chassis control unit adapts the simulated signals to match actual chassis behavior across different operating modes, maintaining accuracy while keeping the system easy to operate through automated adaptation.
Data Source
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AI summary
A method for testing an engine in a vehicle includes arranging a bath separate from the vehicle configured to cool a driveline component of the vehicle, adjusting a temperature of the driveline component to a target temperature, and responsive to the driveline component achieving the target temperature, operating the engine according to a mapping procedure, and controlling the bath to maintain the temperature of the driveline component at the target temperature during the operating. The method further includes measuring heat transfer from the driveline component to the bath during the operating, and calculating torque loss or energy loss of the driveline component during the operating based on the heat transfer.