Active Suspension Valve Control for Lag-Free Surface Compensation
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Solution Overview
Problem
Active suspension systems in vehicles face a delay in adjusting the suspension due to the logarithmic relationship between voltage and current in solenoid valves, which can result in the suspension being adjusted after the vehicle has traversed uneven surfaces.
Innovation Solution
The system employs a modified input voltage that is determined based on the inductance and resistance of the solenoid valves, allowing the electrical current to reach the target current instantaneously or near-instantaneously, thereby eliminating the delay in suspension adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If standard input voltage is applied to the solenoid valve, then the valve opens to adjust suspension, but there is a logarithmic delay before the valve actually opens
Solution Approach 1:
The patent modifies the input voltage parameters applied to the solenoid valve. Specifically, it applies a first voltage level to initially open the valve and a second voltage level to maintain the valve in the open position. This parameter change approach eliminates the logarithmic delay by providing sufficient voltage from the start to immediately overcome the spring force and open the valve.
2Force
If minimum current is applied to counteract the spring force, then the valve can open, but the logarithmic relationship causes delayed response
Solution Approach 1:
The patent applies a preliminary high voltage level to the solenoid valve before the actual suspension adjustment is needed. This preliminary action ensures the valve is already open and ready to pass fluid, eliminating any delay that would occur if minimum current were applied only when adjustment is required.
Solution Approach 2:
The system changes the voltage parameter from a standard single level to a two-level voltage scheme. The first voltage level is specifically designed to be high enough to immediately open the valve by overcoming the spring force, while the second level maintains the open state. This parameter transformation resolves the contradiction between sufficient force and rapid response.
3Reliability
If voltage is applied continuously to maintain valve position, then suspension adjustment is maintained, but power consumption increases
Solution Approach 1:
The patent uses periodic or pulsed voltage application rather than continuous voltage. A first voltage level is applied to open the valve, and then a second, potentially lower or maintenance-level voltage is applied to keep it open. This periodic action maintains reliable suspension positioning while reducing overall power consumption compared to continuous high-voltage application.
Solution Approach 2:
The system changes the voltage parameter over time - using a higher first voltage level to open the valve and then switching to a second voltage level to maintain the position. This temporal parameter change allows the system to achieve reliable positioning with lower average power consumption than continuous high-voltage application.
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
This approach enables the active suspension system to proactively adjust the suspension before the vehicle encounters uneven surfaces, improving ride comfort and reducing power consumption by allowing for shorter bursts of voltage application.
Implementation Method 1
When the input voltage is applied to the valve, the current moves at a logarithmic scale. Furthermore, because the valve also generally includes a spring or a similar component which keeps the valve closed when no electricity is applied to the valve, a minimum current level is generally required to be applied to the valve to counteract the force of the spring keeping the valve closed.
Data Source
AI summary
Systems and techniques for operating an active suspension system are discussed herein. The active suspension system can include a first suspension couple to a first wheel and a second suspension coupled to a second wheel, each suspension can include a first valve, a second valve, and an actuator. While a vehicle is traversing an environment, the vehicle can receive sensor data indicating an uneven surface is within a trajectory of at least the first wheel. A vehicle controller can determine a target position for the actuator of the first suspension, a target current to be generated at the first valve or the second valve and associated with moving the actuator from its current position to the target position, and a target voltage to be apply at the first valve or the second valve to generate the target current to compensate for a change in pitch and/or roll of a vehicle induced by the uneven surface. The vehicle controller can further determine a modified input voltage that causes the target current to be generated at a faster time than the input voltage.