Cross-Linked Hydraulic Actuators for Vehicle Ride and Roll Control
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Solution Overview
Problem
Existing vehicle suspension systems struggle to effectively isolate the vehicle body from road and acceleration-induced disturbances, such as wheel displacement, lateral and fore-aft accelerations, and roll moments, while also maintaining ride-height adjustments.
Innovation Solution
The implementation of cross-linked hydraulic actuator systems, including primary and secondary actuators, multi-source hydraulic intensifiers, and rotary actuators, which work cooperatively to apply forces on the vehicle body to control motion and counteract disturbances, adjust ride-height, and induce roll moments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple actuators are used to control vehicle body motion and counteract disturbances, then the ability to isolate the vehicle body from road and acceleration-induced disturbances is improved, but the device complexity increases
Solution Approach 1:
The patent combines multiple actuators (primary hydraulic actuators and perch actuators) into integrated actuator systems that work cooperatively. The primary actuator controls ride height while the perch actuator controls wheel travel, and both are hydraulically connected to share fluid supply and return lines. This merging approach allows multiple functions to be achieved with coordinated actuator groups rather than completely independent systems, improving disturbance isolation while managing complexity through integration.
Solution Approach 2:
The hydraulic actuators are designed to perform multiple functions. The primary hydraulic actuators can control both ride height adjustment and contribute to roll moment control. The perch actuators control wheel travel while also contributing to the overall suspension force distribution. This multi-functionality allows the actuator systems to address multiple disturbance types (road-induced, acceleration-induced, roll moments) without requiring separate dedicated actuators for each function, thereby improving reliability while controlling device complexity.
2Manufacturing precision
If cross-linked hydraulic actuator systems with multi-source hydraulic intensifiers are implemented, then the control precision over pitch, roll, and ride-height is improved, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent introduces multi-source hydraulic intensifiers as intermediary devices between the hydraulic power supply and the actuators. These intensifiers receive hydraulic fluid from multiple sources (primary hydraulic circuit and secondary hydraulic circuit) and regulate the fluid distribution to achieve precise control of actuator forces. The intensifiers act as mediators that coordinate the hydraulic flow and pressure distribution, enabling precise control of pitch, roll, and ride-height while managing the complexity of the cross-linked hydraulic system through standardized intermediary components.
Solution Approach 2:
The cross-linked hydraulic actuator systems incorporate feedback mechanisms through the hydraulic intensifiers that monitor and regulate fluid pressure and flow distribution. The intensifiers respond to control signals and adjust the hydraulic fluid distribution to maintain desired actuator positions and forces. This feedback control enables precise motion control of pitch, roll, and ride-height by continuously adjusting the hydraulic parameters based on system state, thereby achieving high manufacturing precision while managing system complexity through closed-loop control.
3Reliability
If actuators are used to adjust ride-height and counteract roll moments, then the vehicle stability and comfort are improved, but the energy consumption increases
Solution Approach 1:
The patent employs actuators to generate counteracting forces that balance disturbance forces. The primary actuators generate forces to counteract gravity and maintain ride height, while the perch actuators generate forces to counteract road-induced disturbances and control wheel travel. During roll events, the actuators on opposite sides of the vehicle generate opposing forces to counteract the roll moment. This anti-weight approach allows the system to maintain vehicle stability and comfort by actively counterbalancing disturbances, with energy consumption optimized through coordinated actuator operation that leverages the vehicle's weight and disturbance characteristics.
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
Enhances the ability of vehicle suspension systems to isolate the vehicle body from disturbances, control pitch, roll, and adjust ride-height, providing improved comfort and stability during various driving conditions.
Implementation Method 1
a first hydraulic device (e.g., a hydraulic machine in a power-pack, a hydraulic motor-pump, a hydraulic pump)
Implementation Method 2
a first multi-source hydraulic intensifier with a first port in fluid communication with the first compression volume, a second port in fluid communication with the first extension volume, and a third port in fluid communication with a first volume of the first perch actuator
Data Source
AI summary
Apparatus and methods are described where multiple linear and/or rotary actuators operate cooperatively in, for example, cross-linked arrangements to control the motion of sprung and unsprung masses in a vehicle. The actuators may include linear primary suspension actuators, spring perch actuators and/or rotary roll-bar actuators that, in some operating modes, are driven directly or indirectly by one or more hydraulic machines.