Trailer Hitch Force Control for Active Suspension Sway Reduction
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Solution Overview
Problem
Existing vehicle control systems fail to effectively stabilize trailers during towing, particularly in terms of cornering stability and sway reduction, due to inadequate management of hitch forces and yaw rates.
Innovation Solution
A trailer sway control system that utilizes active suspension actuators and electric motors to adjust vertical forces and torque outputs based on hitch forces, yaw rates, and steering angles, minimizing differences between actual and reference forces and rates to enhance stability and reduce sway.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If existing vehicle control systems are used, then the system complexity remains low, but cornering stability and sway reduction are insufficient
Solution Approach 1:
The control system is segmented into multiple independent active suspension actuators (front left, front right, rear left, rear right) that can be controlled individually. Each actuator independently adjusts vertical forces based on its specific wheel's conditions, allowing localized stabilization without requiring complex centralized control of the entire vehicle-trailer system.
Solution Approach 2:
The system employs dynamic control by continuously adjusting suspension forces and wheel torques in real-time based on measured hitch forces and vehicle dynamics. The control module dynamically modifies actuator outputs responding to changing conditions such as lateral hitch forces during cornering or sway events, rather than using fixed mechanical configurations.
2Stability of the object's composition
If active suspension actuators are used to adjust vertical forces, then trailer sway is reduced, but the device complexity increases
Solution Approach 1:
The control module implements feedback control by continuously measuring hitch forces (longitudinal, lateral, and vertical components) and vehicle dynamics (yaw rate, steering angle, wheel speeds), then using this feedback to adjust actuator outputs. This closed-loop feedback mechanism effectively reduces trailer sway by counteracting destabilizing forces in real-time.
Solution Approach 2:
The system changes physical parameters dynamically by adjusting the vertical force output of each active suspension actuator based on measured conditions. When lateral hitch forces indicate sway or cornering instability, the control module modifies suspension stiffness and damping parameters through actuator adjustment, changing the mechanical characteristics of the vehicle-trailer system to restore stability.
3Reliability
If multiple actuators are controlled based on hitch forces, then the stability improves, but the control complexity increases
Solution Approach 1:
The control system applies local quality by treating each wheel-suspension-trailer connection as a distinct control zone. Each active suspension actuator is controlled based on local conditions at its specific wheel position, with the control module independently adjusting forces for front left, front right, rear left, and rear right actuators based on their respective contributions to hitch forces and vehicle dynamics.
Solution Approach 2:
The control module performs multiple functions simultaneously: it controls active suspension actuators for vertical force adjustment, manages electric motor torque outputs for wheel torque control, processes hitch force measurements in three dimensions, and responds to various vehicle dynamics parameters (yaw rate, steering angle, wheel speeds). This multi-functionality is achieved through a unified control architecture that handles diverse control tasks through integrated algorithms.
Data Source
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AI summary
A trailer sway control system for a vehicle includes: a front left active suspension actuator; a front right active suspension actuator; a rear left active suspension actuator; a rear right active suspension actuator; and an actuator control module configured to: based on (a) a first hitch force at a trailer hitch in a longitudinal direction, (b) a second hitch force at the trailer hitch in a lateral direction, and (c) a third hitch force at the trailer hitch in a vertical direction, determine target vertical forces for the front left active suspension actuator, the front right active suspension actuator, the rear left active suspension actuator, and the rear right active suspension actuator, respectively; and selectively adjust the front left active suspension actuator, the front right active suspension actuator, the rear left active suspension actuator, and the rear right active suspension actuator based on the target vertical forces, respectively.