Steer-by-Wire Actuator Generator Braking for Wheel Damping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Steer-by-wire steering systems face challenges in ensuring safety, particularly when the steering actuator fails to respond to steering commands, leading to uncontrolled wheel movement and potential accidents.
Innovation Solution
The system operates the electric motor in a generator mode as an electromotive brake to dampen or brake the steerable wheels, converting kinetic energy into electrical energy, which is proportional to the damping effect, and includes features like phase short-circuiting and energy storage to enhance braking and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the electric motor is eliminated from the steering actuator, then reliability is improved in case of motor failure, but the ability to control and dampen wheel movement is lost
Solution Approach 1:
The patent applies preliminary action by pre-configuring the steering actuator with a brake device that can be activated in case of emergency. The brake device is prepared in advance and can immediately dampen or prevent wheel movement when the electric motor fails, without requiring complex additional safety systems.
Solution Approach 2:
The brake device serves as an intermediary between the steering actuator and the wheel. When the electric motor fails, the brake device mediates the connection by providing mechanical damping, preventing uncontrolled wheel movement while maintaining the steer-by-wire architecture.
2Volume of moving object
If mechanical coupling is eliminated between steering input device and steering gear, then installation space is reduced and mechanical stress on components is reduced, but safety in case of actuator failure is compromised
Solution Approach 1:
The patent segments the steering system into distinct functional modules: the steering input device, the steering actuator with electric motor, and the brake device. This segmentation allows the brake device to be integrated into the actuator without requiring additional space elsewhere in the vehicle, maintaining the space efficiency of steer-by-wire while adding safety functionality.
Solution Approach 2:
The steering actuator is designed with multi-functionality, serving both as the primary steering actuator during normal operation and as a brake device during emergency situations. This universal design eliminates the need for separate dedicated emergency braking components, preserving the space advantages of steer-by-wire systems.
3Reliability
If redundancy is increased in steering system components, then safety is improved, but device complexity increases
Solution Approach 1:
The patent merges the brake device functionality into the existing steering actuator structure. The brake device shares the actuator's housing, mounting points, and control electronics, creating a combined unit that provides both steering actuation and emergency braking without requiring separate redundant systems.
Solution Approach 2:
The brake device is designed to be self-activating through the control unit that monitors the electric motor's operational status. When a failure is detected, the control unit automatically activates the brake device without requiring additional sensors or complex control systems, allowing the system to self-manage its safety function.
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 effectively prevents uncontrolled wheel movement, allows for a more controlled stop, and maintains stable straight-line stability, improving safety by utilizing the electric motor's active connection to the wheels for braking and damping.
Implementation Method 1
the electric motor is operated in generator mode in a special operating mode... converting kinetic energy into electrical energy, which is proportional to the damping effect
Implementation Method 2
The system operates the electric motor in a generator mode as an electromotive brake to dampen or brake the steerable wheels
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention relates to a method for operating a steer-by-wire steering system (1) of a motor vehicle with a steering input device (2) via which a steering command can be specified, and with a steering gear (3) comprising a steering actuator (5) driven by an electric motor (4) and a coupling element (6), wherein in a normal operating mode, to convert a steering command into a steering movement of steerable wheels (7) of a motor vehicle, a control signal (11) is sent to the electric motor (4) of the steering actuator (5), the electric motor (4) converts the received control signal (11) into a mechanical movement of the steering actuator (5), the steering actuator (5) acting on the coupling element (6), and wherein the electric motor (4) is operated in generator mode in a special operating mode. The invention further relates to a steer-by-wire steering system (1) configured to be operated according to such a method.