Electromagnetic Suspension Actuator Stroke Reversal Correction
Solution Overview
Problem
The existing electrically powered suspension systems face a trade-off between vibration isolation performance of sprung members and grounding performance of unsprung members, making it difficult to achieve both at a higher level corresponding to changing vehicle motion conditions.
Innovation Solution
An electrically powered suspension system that includes an electromagnetic actuator, an information acquirer, a damping force calculator, and a drive controller, which acquires time-series information about stroke position and velocity, and corrects the target damping force based on the stroke amount after reversal to optimize both performance levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the target damping force is enhanced over the reference damping force to improve driving stability, then the grounding performance of unsprung members is improved, but the vibration isolation performance of sprung members deteriorates
Solution Approach 1:
The patent applies dynamics by making the damping force adjustable and time-varying based on vehicle motion conditions. The control unit dynamically adjusts the damping force of the electromagnetic actuator according to real-time stroke velocity and stroke amount information, allowing the system to transition between different damping states to simultaneously achieve grounding performance and vibration isolation performance at different moments.
Solution Approach 2:
The patent changes the damping force parameter based on stroke velocity and stroke amount. By using a velocity-damping force map that defines the relationship between stroke velocity and damping force, and by correcting the target damping force based on stroke amount after reverse, the system optimizes both grounding performance and vibration isolation performance under different motion conditions.
2Object-affected harmful factors
If the target damping force is lowered under the reference damping force to improve vibration isolation performance, then the ride quality is improved, but the grounding performance of unsprung members deteriorates
Solution Approach 1:
The system dynamically adjusts damping force based on real-time motion conditions. When vibration isolation is prioritized (e.g., during normal riding), the damping force is lowered under the reference value. When grounding performance is needed (e.g., during braking or cornering), the damping force is enhanced, allowing the system to adapt to different performance requirements.
Solution Approach 2:
The damping force parameter is adjusted based on stroke velocity from the velocity-damping force map and corrected based on stroke amount after reverse. This parameter change strategy allows the system to achieve lower damping forces for vibration isolation when needed, while maintaining the capability to increase damping for grounding performance.
3Device complexity
If the damping force is adjusted based only on stroke velocity using a velocity-damping force map, then the control is simplified, but the system cannot fulfill both vibration isolation performance and grounding performance at a higher level corresponding to changing motion conditions
Solution Approach 1:
The patent introduces feedback by using stroke amount information after reverse to correct the target damping force. The control unit acquires time-series stroke position information, calculates stroke amount after reverse, and uses this feedback to adjust the damping force correction, enabling the system to achieve both vibration isolation and grounding performance without significantly increasing control complexity.
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 system effectively fulfills the vibration isolation and grounding performance requirements simultaneously, enhancing ride quality and driving stability by dynamically adjusting damping forces according to changing motion conditions.
Implementation Method 1
an electromagnetic actuator provided between a vehicle body and a wheel of a vehicle, and which generates a drive force for damping vibration of the vehicle
Data Source
AI summary
Included are an electromagnetic actuator which generates a drive force for damping vibration of a vehicle body; an information acquirer which acquires time-series information about a stroke position of, and information about a stroke velocity of, the electromagnetic actuator, as well as information about reverse of a stroke direction and information about a stroke amount after the reverse; a damping force calculator which calculates a target damping force based on the information about the stroke velocity; and a drive controller which controls drive of the electromagnetic actuator using a target drive force based on the target damping force calculated by the damping force calculator. The damping force calculator corrects the target drive force based on the information about the stroke amount after the reverse acquired by the information acquirer.