Vehicle Motion Planning Around Future Actuator Limits
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle motion control methods fail to consider the future limits of actuators, such as temperature rise and power source exhaustion, leading to sudden loss of ride quality and handling stability.
Innovation Solution
A vehicle motion control device and method that calculates future actuator limits, particularly suspension actuator temperature rise, to maintain optimal vehicle attitude and stability by planning vehicle motion within achievable actuator ranges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If damping force of shock absorber is adjusted to maintain ride quality and handling stability, then vehicle control performance is improved, but temperature rise of hydraulic oil inside the shock absorber occurs
Solution Approach 1:
The control device performs preliminary actions by predicting future actuator limits before they are reached. It calculates predicted actuator output values based on planned vehicle motion and compares them with predicted actuator limit values, allowing the system to adjust control strategies in advance to prevent temperature rise and power source exhaustion, rather than reacting after the problem occurs.
Solution Approach 2:
The system dynamically adjusts the vehicle motion plan based on real-time actuator state. When the predicted actuator output approaches the predicted limit, the control device modifies the vehicle motion plan to reduce the demand on the actuator, creating a dynamic adaptation that maintains ride quality while preventing actuator failure.
2Measurement precision
If actuator operation is increased to maintain vehicle attitude control, then vehicle motion control accuracy is improved, but actuator limit is reached sooner
Solution Approach 1:
The control device performs preliminary actions by predicting future actuator limits before they are reached. It calculates predicted actuator output values based on planned vehicle motion and compares them with predicted actuator limit values, allowing the system to adjust control strategies in advance to prevent temperature rise and power source exhaustion, rather than reacting after the problem occurs.
Solution Approach 2:
The system uses feedback from the actuator's current state (temperature, remaining power) to continuously adjust the vehicle motion plan. The control device monitors the actuator output value against the limit value and modifies the motion plan in real-time to maintain control accuracy while extending actuator operational duration.
3Reliability
If vehicle motion plan is optimized for ideal conditions, then ride quality is improved, but actuator limits are exceeded
Solution Approach 1:
The control device applies preliminary anti-action by predicting actuator limits before they are exceeded and adjusting the vehicle motion plan in advance to prevent the harmful outcome. It calculates the difference between predicted actuator output and predicted limit values, and modifies the motion plan proactively to ensure actuator limits are not exceeded, thereby preventing ride quality degradation.
4Temperature
If damping amount is adjusted to suppress temperature rise, then hydraulic oil temperature control is improved, but ride quality and handling stability deteriorate
Solution Approach 1:
The system dynamically adjusts the vehicle motion plan based on real-time actuator state. When the predicted actuator output approaches the predicted limit, the control device modifies the vehicle motion plan to reduce the demand on the actuator, creating a dynamic adaptation that maintains ride quality while preventing actuator failure.
Solution Approach 2:
The system uses feedback from the actuator's current state (temperature, remaining power) to continuously adjust the vehicle motion plan. The control device monitors the actuator output value against the limit value and modifies the motion plan in real-time to maintain control accuracy while extending actuator operational duration.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Provided is a vehicle motion control device capable of performing highly accurate vehicle motion control in consideration of limits that will occur in actuators in the future. The vehicle motion control device includes: an actuator characteristic change estimation unit configured to estimate a characteristic change of an actuator at a future time from a current time; a controllable range estimation unit configured to calculate a controllable range of a vehicle motion from a characteristic change calculated by the actuator characteristic change estimation unit, a target track of a vehicle, and a current vehicle state; a vehicle motion planning unit configured to create a motion plan within a controllable range calculated by the controllable range estimation unit; an evaluation value calculation unit configured to calculate an evaluation value based on a motion plan created by the vehicle motion planning unit; and a determination unit configured to determine whether or not an evaluation value calculated by the evaluation value calculation unit is minimum. The controllable range estimation unit refers to a target track of the vehicle and calculates a controllable vehicle motion range at a future time in consideration of a characteristic including at least an output range of an actuator regarding a vehicle motion from a current time. The vehicle motion planning unit creates a motion plan with reference to a predetermined evaluation function within the controllable vehicle motion range calculated by the controllable range estimation unit.