Vehicle Steering Device with Selective Mechanical Decoupling
Solution Overview
Problem
In vehicle steering systems with steer-by-wire technology, the lack of mechanical connection between the upper and lower steering systems leads to a loss of steering function when the lower steering system's power is ineffective, as there is no direct mechanical means to transfer power or control.
Innovation Solution
The introduction of a transmission assembly with clutches between the upper and lower steering systems, allowing the upper steering system to be mechanically decoupled or connected based on power availability, enabling the upper system to provide steering power when the lower system's power is ineffective, and allowing independent control of wheels with different Ackermann angles for improved stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If steer-by-wire technology is used to completely free people from driving behavior, then automation level is improved, but reliability deteriorates because there is no mechanical connection between upper and lower steering systems
Solution Approach 1:
A transmission assembly is introduced as an intermediary mechanical connection between the upper steering system and lower steering system. This transmission assembly includes transmission wheels and transmission belts that can mechanically transfer steering power when the lower steering system fails, while still allowing full automation operation when the lower system is functional.
Solution Approach 2:
The steering system is segmented into independent upper and lower systems with a selective mechanical connection. The clutches divide the power transmission path into separate segments that can be independently engaged or disengaged, allowing the system to operate in fully automated mode or switch to mechanical backup mode when needed.
2Reliability
If mechanical connection is maintained between upper and lower steering systems for backup steering, then reliability is improved, but device complexity increases
Solution Approach 1:
The mechanical connection between upper and lower steering systems is made dynamic rather than static. Clutches are used to selectively engage or disengage the mechanical connection based on system needs, allowing the structure to adapt between fully connected and fully decoupled states, reducing unnecessary mechanical interference during normal operation.
3Ease of operation
If the upper steering system is mechanically decoupled from the lower steering system during normal operation, then ease of operation is improved for automated driving, but reliability deteriorates when lower system power fails
Solution Approach 1:
The transmission assembly is pre-configured and positioned between the upper and lower steering systems during system setup, but remains in a disengaged state during normal automated operation. In the event of lower system failure, the clutches can be quickly engaged to establish the mechanical connection, providing immediate backup without requiring complex real-time adjustments.
4Adaptability or versatility
If clutches are used to connect upper steering system to transmission assembly and lower steering system to transmission assembly, then adaptability is improved for different operating modes, but device complexity increases
Solution Approach 1:
The transmission assembly serves multiple functions: it can transmit power from the lower steering system to the wheels during normal operation, it can transmit power from the upper steering system to the wheels during backup operation, and it can isolate the upper and lower systems when they need to operate independently. This multi-functionality reduces the need for separate dedicated mechanisms for each operating mode.
Data Source
Figure 1~2
Figure 3~5
Figure 6~7
AI summary
A vehicle steering apparatus is disclosed, including an upper steering system (1), a lower steering system (2), transmission assemblies (3, 7), and clutches (4, 5, 6, 8, 9). The upper steering system (1) and the lower steering system (2) are separately connected to the transmission assemblies (3, 7) by using the clutches (4, 5, 6, 8, 9). A vehicle is also disclosed. In the steering apparatus, when power of the lower steering system (2) is effective, the clutches (4, 5, 6, 8, 9) between the upper steering system (1) and the transmission assemblies (3, 7) may be in a disengaged state, and the upper steering system (1) is mechanically decoupled from the lower steering system (2), so that a steering wheel (12) in the upper steering system is idle in an automatic driving state, to improve driving experience. When power of the lower steering system (2) is ineffective, the clutches (4, 5, 6, 8, 9) between the upper steering system (1) and the transmission assemblies (3, 7) and the clutches (4, 5, 6, 8, 9) between the lower steering system (2) and the transmission assemblies (3, 7) are all in an engaged state, and the upper steering system (1) and the lower steering system (2) are mechanically connected by using the transmission assemblies (3, 7), so that a driver can operate the upper steering system (1) to provide power for the lower steering system (2), to implement steering of the vehicle.