Vehicle Suspension Damping Control Under Actuator Output Limits
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Solution Overview
Problem
Existing suspension control systems face challenges in optimally distributing damping forces while considering the physical operating limits of suspension actuators, particularly in integrated vehicle control systems, leading to difficulties in calculating damping forces efficiently and quickly.
Innovation Solution
A control device and method that includes a processor to identify the current state of the vehicle, determine the output range of suspension actuators based on damper speed, and adjust the target damping force to account for physical limits, using a sensor unit and memory to optimize damping force distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If optimal control is performed under unconstrained condition, then damping force distribution is simplified, but physical operating limits of suspension actuator are violated
Solution Approach 1:
The patent applies dynamics by transforming the static constrained optimization problem into a dynamic solution process. The controller dynamically adjusts the damping force distribution based on real-time actuator output limits, using a dynamic programming approach that adapts to changing vehicle conditions and actuator capabilities during operation.
Solution Approach 2:
The patent changes parameters by introducing a Lagrange multiplier as an additional parameter to handle the constraint. The optimization problem is transformed from minimizing damping force subject to actuator limits into an unconstrained optimization by incorporating the constraint through the Lagrange multiplier, allowing standard optimization algorithms to be used while respecting physical limits.
2Reliability
If constrained optimal control is performed considering actuator output range, then physical limits are respected, but calculation time increases significantly
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing the relationship between actuator output limits and corresponding damping forces in lookup tables. During real-time operation, the controller quickly retrieves pre-computed values based on current actuator limits rather than performing full optimization calculations, dramatically reducing computation time while maintaining accuracy.
Solution Approach 2:
The patent uses copying by creating simplified models or lookup tables that replicate the complex constrained optimization results. These copied solutions are stored in advance and referenced during real-time control, allowing the system to achieve optimal damping force distribution without repeatedly solving the computationally intensive constrained optimization problem.
3Manufacturing precision
If damping force is optimized for current state, then vehicle comfort is improved, but actuator output limit is exceeded
Solution Approach 1:
The patent applies feedback by continuously monitoring the actual actuator output and comparing it with the desired damping force. When the actuator approaches its output limit, the feedback mechanism detects this condition and adjusts the damping force distribution to remain within feasible bounds, preventing actuator saturation while maintaining optimal vehicle comfort.
Solution Approach 2:
The patent applies preliminary anti-action by proactively preventing actuator saturation before it occurs. The controller predicts when the desired damping force might exceed actuator limits and pre-adjusts the damping force distribution to stay within feasible ranges, avoiding the harmful effects of actuator saturation and the need for corrective actions.
Data Source
AI summary
The present disclosure relates to a suspension control device, a control method therefor, and a vehicle including the same. The control device for controlling each suspension in a vehicle according to some embodiments includes at least: a memory and a processor that controls a damping force provided through each suspension in the vehicle using information stored in the memory. The processor identifies a current state of the vehicle using sensor data of a sensor unit of the vehicle, performs a first process of obtaining a currently damping force for a damper of each suspension according to the identified current state, identifies an output range for an output of an actuator of each damper, which changes according to a damper speed, and performs a second process of determining a target damping force for each damper in consideration of the identified output range.