Road Slope Estimation Using Gravitational Acceleration Sensor
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Solution Overview
Problem
Existing methods for estimating road slope, particularly using driving torque, face inaccuracies and inability to distinguish between load due to road slope and load from towing or carrying freight, while methods employing gravitational acceleration sensors lack reflection of increased driving resistance.
Innovation Solution
A method and apparatus utilizing a gravitational acceleration sensor to determine whether a vehicle is in a towing or freight carrying mode, calculating a difference value between road slope estimates from the gravitational acceleration sensor and driving torque, and correcting road slope estimates accordingly to reflect increased driving resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If road slope is estimated using driving torque, then additional sensors are not required, but measurement precision deteriorates due to inability to distinguish load from towing or carrying freight
Solution Approach 1:
The patent combines data from multiple sources (gravitational acceleration sensor, driving torque sensor, vehicle speed sensor) to estimate road slope. By merging these different measurement approaches, the system achieves both accurate slope estimation and the ability to distinguish between slope-induced load and load from towing or carrying freight, while avoiding the need for additional specialized sensors.
Solution Approach 2:
The system uses a multi-functional estimation approach where the gravitational acceleration sensor serves multiple purposes: detecting both road slope and driving resistance characteristics. This universal sensor performs dual functions, allowing the system to distinguish between slope effects and load effects without requiring separate specialized sensors for each function.
2Measurement precision
If road slope is estimated using gravitational acceleration sensor, then measurement precision and responsiveness are improved, but driving resistance from towing or carrying freight is not reflected
Solution Approach 1:
The system continuously monitors multiple parameters including gravitational acceleration, driving torque, and vehicle speed, then uses feedback from these measurements to distinguish between slope-induced acceleration changes and resistance-induced acceleration changes. This feedback mechanism allows the system to adapt the road slope estimation based on detected driving resistance patterns.
Solution Approach 2:
The patent changes the approach by not relying on a single parameter (gravitational acceleration) but by analyzing multiple parameters simultaneously (acceleration, torque, speed) and their relationships. By monitoring how these parameters change together, the system can distinguish between slope effects and resistance effects, making the estimation adaptable to different driving conditions.
3Speed
If road slope estimation does not reflect increased driving resistance, then responsiveness is fast, but reliability deteriorates due to inaccurate shift control
Solution Approach 1:
The system performs preliminary analysis of driving patterns and torque characteristics before making shift control decisions. By pre-processing the data from gravitational acceleration sensors and torque sensors to detect patterns indicative of towing or carrying freight, the system prepares accurate road slope estimates in advance, ensuring reliable shift control while maintaining fast responsiveness.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the accuracy of road slope estimation, improves drivability by accounting for increased driving resistance, and prevents frequent shifting, thereby improving vehicle performance.
Implementation Method 1
the method of estimating road slope using the gravitational acceleration sensor involves detecting a longitudinal acceleration when the vehicle is located on a slope
Data Source
AI summary
A method of estimating road slope using a gravitational acceleration sensor, includes determining whether a driving mode of a vehicle is a towing or freight carrying mode, calculating a difference value between road slope measured using the gravitational acceleration sensor and road slope measured using a driving torque when the driving mode of the vehicle is the towing or freight carrying mode, estimating road slope by correcting the road slope measured using the gravitational acceleration sensor based on the difference value, and controlling a shift of the vehicle according to the estimated road slope.