Rear Suspension Damping Control From Front Wheel Obstacle Force
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing control systems for straddle type vehicles, such as motorcycles, struggle to maintain appropriate damping force in the rear suspension due to differences in load between the front and rear wheels, leading to compromised steering stability and riding comfort, especially when the vehicle's state changes like during banking or acceleration.
Innovation Solution
A control system that estimates a second force acting on the rear wheel based on a first force acting on the front wheel, using sensors to detect vehicle states and obstacles, allowing for real-time adjustment of the rear suspension damping force without requiring a stroke sensor on the rear wheel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the damping force of the rear suspension is controlled based on the assumption that load from road surface is the same between front wheel and rear wheel, then the control system is simple, but the steering stability and riding comfort deteriorate when the vehicle state changes (bank angle, acceleration)
Solution Approach 1:
The patent transforms the physical quantity parameter from direct rear wheel stroke detection to front wheel stroke detection combined with vehicle state parameters (bank angle, acceleration). By changing the measurement location and using parameter conversion through the relationship model, the system achieves accurate rear suspension control without direct rear wheel sensors, resolving the contradiction between system simplicity and control reliability.
Solution Approach 2:
The patent introduces vehicle state parameters (bank angle, acceleration) as intermediary variables that mediate between front wheel stroke detection and rear suspension control. These intermediaries capture the load distribution changes between front and rear wheels, enabling accurate rear suspension damping force control without direct rear wheel measurement, thus maintaining reliability while simplifying the system.
2Measurement precision
If a stroke sensor is installed on the rear wheel to directly detect stroke displacement, then the damping force control accuracy is high, but the device complexity and cost increase
Solution Approach 1:
The patent creates a virtual copy of the rear wheel stroke displacement signal by using the front wheel stroke sensor data combined with vehicle state parameters. Instead of installing a physical sensor on the rear wheel, the system generates an equivalent stroke displacement signal through calculation and modeling, achieving the same measurement precision without the additional hardware complexity and cost.
3Ease of manufacture
If the load from road surface is assumed to be the same between front wheel and rear wheel, then the control system is simple, but the damping force control becomes inappropriate when bank angle or acceleration changes
Solution Approach 1:
The patent transitions from a static assumption (equal load between front and rear wheels) to a dynamic model that adapts to changing vehicle states. By incorporating bank angle and acceleration parameters that vary with vehicle operation, the system dynamically adjusts the load distribution calculation, maintaining both implementation simplicity and adaptability to different driving conditions.
Data Source
AI summary
The present invention provides a control system of a straddle type vehicle, estimating a second force acting on a rear wheel of the straddle type vehicle from an obstacle, on a basis of a first force acting on a front wheel of the straddle type vehicle from the obstacle; and controlling a rear suspension mechanism configured to support the rear wheel, on a basis of an estimation result, when the rear wheel is affected by the obstacle, wherein a force converted from the first force according to a difference in a state of the straddle type vehicle between when the front wheel is affected by the obstacle and when the rear wheel is affected by the obstacle is estimated as the second force.