Stowable Steering Column Locking for Autonomous-Manual Transition
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Solution Overview
Problem
Current stowable steering systems for autonomous vehicles lack a seamless transition between autonomous and manual steering configurations, often requiring complex mechanical arrangements that compromise ease of use and reliability.
Innovation Solution
A stowable steering column design featuring a static member, a rotatable lower column, and interconnected upper and inner columns, with a motor and powered lock system that allows for automatic switching between autonomous and manual modes, enabling smooth transition and precise control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If a stowable steering wheel system is implemented for autonomous vehicles, then the vehicle can operate in autonomous mode with reduced driver intervention, but the system complexity increases due to multiple columns and locking mechanisms
Solution Approach 1:
The steering column is divided into multiple segments: a static member, a rotatable lower column, a rotatable inner column, and a rotatable upper column. This segmentation allows each component to perform specific functions independently, enabling the complex autonomous/manual transition capability while managing overall system complexity through modular design.
Solution Approach 2:
The patent implements a nested column structure where the inner column is positioned within the lower column, and the upper column is positioned within the inner column. This nesting arrangement allows multiple functional elements to be compactly integrated, reducing spatial requirements while maintaining the complexity needed for autonomous operation.
2Reliability
If multiple locking positions are implemented for the inner column, then reliable mode switching between autonomous and manual steering is achieved, but the device complexity increases
Solution Approach 1:
The powered lock is designed to engage with specific gear teeth at different positions along the inner column's rotation path. By providing localized locking engagement at precisely defined positions (first position for autonomous mode, second position for manual mode), the system achieves reliable mode switching without requiring complex locking mechanisms throughout the entire structure.
Solution Approach 2:
The powered lock acts as an intermediary mechanism between the control system and the steering column components. It mediates the transition between autonomous and manual modes by selectively engaging different gear teeth positions, simplifying the control architecture while ensuring reliable mode switching.
3Ease of operation
If the upper column is made telescopic for retraction, then seamless transition between autonomous and manual modes is achieved, but the manufacturing complexity increases
Solution Approach 1:
The upper column is designed with telescopic capability, allowing it to dynamically extend and retract along its longitudinal axis. This dynamic adjustment enables the steering wheel to move smoothly between retracted (autonomous) and extended (manual) positions, providing seamless transition while the modular telescopic design facilitates manufacturing.
Solution Approach 2:
The telescopic upper column serves multiple functions: it enables the retraction motion for autonomous mode, provides the extended position for manual mode, and acts as a structural support element. This multi-functionality reduces the need for separate components, simplifying manufacturing despite the dynamic capability.
4Measurement precision
If an angular position sensor is integrated into the motor, then precise steering command signal generation is achieved, but the device complexity increases
Solution Approach 1:
The angular position sensor is integrated directly into the motor assembly, merging the sensing function with the actuation function. This integration allows the motor to simultaneously provide rotational motion and generate precise angular position feedback, enabling accurate steering command signal generation without requiring separate sensing components.
Solution Approach 2:
The motor assembly serves itself by incorporating the angular position sensor internally. The motor structure provides the mounting and operational environment for the sensor, and the sensor directly measures the motor's rotational position to generate steering commands, eliminating the need for external sensing systems.
Data Source
AI summary
A steering column for autonomous vehicles includes a powered actuator controlling rotation of a lower column, an inner column, and an upper column that is movable relative to the lower and inner columns. Rotation of the lower column relative to the upper column moves the upper column lengthwise. A powered lock rotatably interconnects the inner and lower columns when in a first position, and locks the inner column to a base when in a second position. In an autonomous mode, the upper column is stowed, the powered lock is in the first position, and the motor inhibits rotation of the lower column. In a manual mode, the upper column is extended, the powered lock is in the second position, and a sensor detects an angular position of the upper column.