Semi-active shock absorber control system
AssigneeActiveShock, Inc.
InventorsJohn A. LaPlante, William T. Larkins
Life of this patent
Estimating the term…
Abstract
A semi-active control methodology is provided for a spring/mass system, for example a real-time adjustable shock absorber system. The methodology includes defining a plurality of operating zones based on system parameters and user-definable or preset inputs. The methodology also includes processing to account for non-inertial spring/mass system response and multidimensional forces acting on the system, and an acceleration hedge calculation to accurately define system operation at extrema of travel. The methodology is generally directed at producing a plurality of valve control signals, selecting among the valve control signals, and applying the selected control signal to the valve in a closed-loop feedback system to adjust the energy in the spring/mass system.
Claims35
A shock absorber controller for generating a target control signal to adjust the energy in a spring mass system, said spring mass system comprising at least two masses, a spring coupled between said masses and a controllable damper, said shock absorber controller comprising:
- a plurality of inputs configured to receive input signals representing parameters selected from the group consisting of a relative position of said masses, a relative velocity of said masses, accelerations of said masses, a spring constant of said spring mass system, a mass of at least one said masses, a critically damped coefficient of said spring mass system, an upper force threshold for a critically damped force in said spring mass system, and an endstop position of said spring mass system;
- a first processor configured to determine if said spring mass system is compressing or expanding based on at least said relative velocity of said masses with respect to one another;
- at least second and third processors configured to generate control signals to control said controllable damper in said spring mass system in response to at least one of said input signals;
- and
- a fourth processor configured to select one of said control signals based on said spring mass system compressing or expanding and based on a comparison of said control signals and configured to generate a target control signal based on said selected signal, said target signal being proportional to a desired energy in said spring mass system.
A shock absorber controller for generating a target control signal to adjust energy in a spring mass system, said shock absorber controller comprising:
- inputs configured to receive system parameter signals from said spring mass system and to receive a comfort force signal proportional to an upper force threshold for a critical damping force;
- a determination processor configured to determine if said spring mass system is compressing or expanding;
- an endstop processor configured to generate an endstop force signal proportional to an endstop damping force;
- a critically damped processor configured to generate a damped force signal proportional to said critical damping force;
- and
- a selection logic processor configured to select one of said endstop force signal, said damped force signal, or said comfort force signal based on said spring mass system compressing or expanding and based on a comparison of said force signals and to generate a target control signal based on said selected signal, said target signal being proportional to a desired energy in said spring mass system.
A shock absorber control system for adjusting energy in a spring mass system comprising at least two masses, a spring between said masses, and a controllable valve, said shock absorber control system comprising:
- sensors for measuring system parameters in said spring mass system including at least a relative position of said masses;
- a controller configured to receive said system parameters, to generate a plurality of control signals based on said system parameters, and to generate a target control signal based on a selected one of said control signals, said target control signal being proportional to a desired energy in said spring mass system;
- and
- a valve controller configured to control said valve in said spring mass system in response to said target control signal such that said control system operates as a feedback control loop.
A controller for generating a target control signal to adjust the energy in a spring mass system comprising at least two masses, a spring coupled between said masses, and a controllable valve, said selection logic processor comprising:
- means for receiving a quadrant signal, an endstop force signal, a critical damping force signal, a comfort force signal, a valve prepositioning signal, and an acceleration hedge signal;
- means for selecting one of said endstop force signal, said critical damping force signal, said comfort force signal, or said valve prepositioning signal based on said quadrant signal and a comparison of said endstop force signal, said critical damping force signal, and said comfort force signal;
- and
- means for adding said acceleration hedge signal to a selected one of said endstop force signal, said critical damping force signal, or said comfort force signal.
A controller for generating a target inertial and non-inertial energy control signal in a spring/mass shock absorber system comprising two masses coupled together by a spring having a controllable valve to adjust the energy in said system, said controller comprising:
- an inertial endstop processor configured to generate an endstop signal based on the relative velocity and relative position of said two masses, said inertial endstop signal comprising a signal that is proportional to the minimum acceleration necessary for one of said masses to arrive at a position of maximum or minimum travel at approximately zero velocity;
- a non-inertial endstop processor configured to modify said endstop signal with a signal indicative of the absolute velocity and the absolute displacement of said masses with respect to one another;
- and
- a selection processor configured to determine if said endstop signal should be designated as a target control signal for said controllable valve based on the relative velocity of said masses.
A controller for generating a target multidimensional damped energy control signal in a spring/mass shock absorber system comprising two masses coupled together by a spring having a controllable valve to adjust the energy in said system, said controller comprising:
- a critically damped processor configured to generate a damped signal based on a spring force constant, said damped signal comprising a signal proportional to a damped trajectory of at least one of said masses in the z direction, wherein said damped signal is multiplied by a critically damped coefficient;
- a pitch and roll processor configured to modify said critically damped coefficient based on a measured acceleration of at least one of said two masses in the x and/or y direction;
- and
- a selection logic processor configured to determine if said damped signal should be designated as a target control signal for said controllable valve.
A controller for generating a target direct valve control signal in a spring/mass shock absorber system comprising two masses coupled together by a spring and a controllable valve to adjust the energy in said system, said controller comprising:
- a valve prepositioning processor configured to generate a first valve prepositioning signal to bias said valve so that the system anticipates an impulse acceleration that will occur to the system and to generate a second valve prepositioning signal to bias the valve at approximately the open position to allow the mass to freely move apart within the constraints of the system;
- and
- a selection logic processor configured to select between said first or second valve prepositioning signals to be designated as a target control signal for said controllable valve.
A controller for modifying a valve control signal with an acceleration hedge control signal in a spring/mass shock absorber system comprising two masses coupled together by a spring having a controllable valve to adjust the energy in said system, said controller comprising:
- processors configured to generate a plurality of valve control signals based on the relative velocity of said masses;
- an acceleration hedge processor configured to generate an acceleration hedge signal proportional to the addition of the acceleration or force of a first one the masses to that of the second one mass to drive the average acceleration or force of the second mass to approximately equal the actual acceleration or force of the first mass;
- and
- a selection logic processor configured to add said acceleration hedge signal to a selected one of said valve control signals.
Dependencies are inferred from the claim text.