Vehicle Handwheel Absolute Position Determination via Torque Monitoring
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Solution Overview
Problem
The use of absolute position sensors in vehicles is expensive, necessitating a cost-effective alternative for determining the absolute rotational position of a vehicle handwheel.
Innovation Solution
A method and system that monitor torque and rotational speed of the vehicle handwheel, setting an absolute position value based on threshold levels and storing it in a memory device, utilizing a torque sensor, position sensor, and microprocessor without requiring an absolute rotational position sensor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an absolute position sensor is utilized to measure the position of a vehicle handwheel, then measurement precision is improved, but device cost increases
Solution Approach 1:
The patent creates a virtual copy of absolute position sensing capability through software algorithms that process data from relative position sensors and torque sensors. Instead of using an expensive absolute position sensor, the system computes absolute position information by integrating relative position changes and detecting torque-induced deviations, thereby achieving the measurement function at lower cost
Solution Approach 2:
The patent replaces the mechanical/electrical absolute position sensor with a computational system using microprocessors. The system substitutes physical sensing hardware with algorithmic processing of torque and relative position data, using mathematical models to infer absolute position without direct physical measurement
2Ease of manufacture
If a cost-effective alternative to absolute position sensor is used, then device cost is reduced, but device complexity increases
Solution Approach 1:
The patent makes existing components perform multiple functions. The torque sensor, originally designed for detecting steering torque, is also used for detecting handwheel position deviations. The relative position sensor serves both for position feedback and for computing absolute position through integration. This multi-functionality reduces the need for additional dedicated components
Solution Approach 2:
The patent introduces a microprocessor as an intermediary that mediates between the simple relative position sensor and the complex absolute position determination function. The microprocessor runs algorithms that process sensor data and compute absolute position, acting as a computational bridge that transforms simple sensor inputs into sophisticated position information
Data Source
AI summary
A system and a method for determining an absolute rotational position of the vehicle handwheel are provided. In one exemplary embodiment, a method includes monitoring an amount of torque applied to the vehicle handwheel. The method further includes monitoring a rotational speed of the vehicle handwheel. The method further includes setting an absolute position value indicating the absolute position of the vehicle handwheel equal to a predetermined steering travel limit of the vehicle handwheel when both the amount of torque applied to the vehicle handwheel is greater than or equal to a threshold torque level, and the rotational speed of the vehicle handwheel is less than or equal to a threshold rotational speed. The method further includes storing the absolute rotational position value in a memory device.