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US 5,582,385 AGranted
Method for controlling motion using an adjustable damper
AssigneeThe Lubrizol Corporation
InventorsFrederick P. Boyle, Nicholas K. Petek, Dale P. Smith
Life of this patent
Estimating the term…
Abstract
The relative motion and force between two interconnected elements can be controlled by a semi-active damper to minimize the instances of the motion exceeding acceptable limits, while maximizing isolation between the elements. Applying an algorithm to the control parameters of the damper provides excellent isolation from input vibration and shocks. The dampers and control algorithms are useful in primary vehicle suspension systems, cab mounts, seat mounts, and engine mounts.
Claims66
A method for controlling the relative motion between two elements movably interconnected through a linkage which includes a spring assembly which tends to maintain the elements at an equilibrium position, at least the first element thereof being subjected to externally generated motion inputs and tending to transmit a first force in response thereto to the second element thereof;
- said elements being provided with a means for applying a second, controlled, force therebetween;
- said method comprising:
- (a) measuring the displacement x.sub.rel of the second element relative to the first element, x.sub.rel being defined as zero at the equilibrium position;
- (b) determining the relative velocity v.sub.rel between said first and second elements;
- (c) calculating a force F.sub.applied defined as:
- F.sub.applied =F.sub.calc -F.sub.sys
- where F.sub.calc is a force, calculated from data determined from knowledge of the position and motion of the elements, sufficient to prevent the relative motion of the elements from exceeding predetermined limits, and
- F.sub.sys is a nonzero sum of the forces acting between the first and second elements other than the controlled force applied by the second force means,
- provided that
- F.sub.applied =0 if said force F.sub.applied is in the same direction as the relative velocity v.sub.rel of the elements, or if .vertline.v.sub.rel .vertline..ltoreq.v.sub.db, where v.sub.db is a velocity deadband with a preselected value greater than or equal to zero, and
- F.sub.applied =F.sub.max if said force F.sub.applied is in direction opposite the relative velocity v.sub.rel of the elements, and greater than the maximum force F.sub.max that can be applied by the second force means in the direction of F.sub.applied ;
- and
- (d) applying said force F.sub.applied between the first and second elements;
- whereby the force transmitted from the first element to the second element and the relative displacement between said elements are controlled.
11 more elements
A method for controlling the relative motion between two elements movably interconnected through a linkage which includes a spring assembly which tends to maintain the elements at an equilibrium position, at least the first element thereof being subjected to externally generated motion inputs and tending to transmit a first force in response thereto to the second element thereof;
- said elements being situated within extreme limits of acceptable displacement therebetween of x.sub.+limit in a positively defined direction and x.sub.-limit in a negatively defined direction;
- said elements being provided with a means for applying a second, controlled, force therebetween;
- said method comprising:
- (a) measuring the displacement x.sub.rel of the second element relative to the first element, x.sub.rel being defined as zero at the equilibrium position;
- (b) calculating the (i) relative velocity v.sub.rel and (ii) relative acceleration a.sub.rel of the elements;
- (c) calculating an applied force F.sub.applied, defined as ##EQU23## where:
- v.sub.db is a velocity deadband with a preselected value greater than or equal to zero,
- m is the effective mass of the second element,
- d is the distance from the relative displacement to the acceptable extreme displacement limit x.sub.+limit or x.sub.-limit in the direction of the relative velocity v.sub.rel,
- F.sub.sys is the sum of the forces acting between the first and second elements other than the controlled force applied by the second force means, and
- (d) applying said force F.sub.applied between the first and second elements;
- provided that
- (i) if the direction of said force F.sub.applied is in the same direction as the relative velocity v.sub.rel, then said force F.sub.applied =0,
- (ii) if said force F.sub.applied is in direction opposite the relative velocity v.sub.rel, and greater than the maximum force F.sub.max that can be applied by the second force means in the direction of F.sub.applied, then F.sub.max is applied;
- whereby the force transmitted and the relative displacement between said elements are controlled.
12 more elements
A method for controlling the relative motion between two elements movably interconnected through a linkage which includes a spring assembly which tends to maintain the elements at an equilibrium position, at least the first element thereof being subjected to externally generated motion inputs and tending to transmit a first force in response thereto to the second element thereof;
- said elements being situated within extreme limits of acceptable displacement therebetween of x.sub.+limit in a positively defined direction and x.sub.-limit in a negatively defined direction;
- said elements being provided with a means for applying a second, controlled, force therebetween;
- said method comprising:
- (a) measuring the displacement x.sub.rel of the second element relative to the first element, x.sub.rel being defined as zero at the equilibrium position;
- (b) calculating the relative velocity v.sub.rel of the two elements;
- (c) calculating an applied force F.sub.applied, defined as ##EQU24## where:
- v.sub.db is a velocity deadband with a preselected value greater than or equal to zero,
- m is the effective mass of the second element,
- d is the distance from the relative displacement to the acceptable extreme displacement limit x.sub.+limit or x.sub.-limit in the direction of the relative velocity v.sub.rel,
- F.sub.sys is the sum of the forces acting between the first and second elements other than the controlled force applied by the second force means, and
- (d) applying said force F.sub.applied between the first and second elements;
- provided that
- (i) if the direction of said force F.sub.applied is in the same direction as the relative velocity v.sub.rel, then said force F.sub.applied =0
- (ii) if said force F.sub.applied is in direction opposite the relative velocity v.sub.rel, and greater than the maximum force F.sub.max that can be applied by the second force means in the direction of F.sub.applied, then F.sub.max is applied;
- whereby the force transmitted and the relative displacement between said elements are controlled.
12 more elements
A method for controlling the relative motion between two elements movably interconnected through a linkage which includes a spring assembly which tends to maintain the elements at an equilibrium position, at least the first element thereof being subjected to externally generated motion inputs and tending to transmit a first force in response thereto to the second element thereof;
- said elements being situated within extreme limits of acceptable displacement therebetween of x.sub.+limit in a positively defined direction and x.sub.-limit in a negatively defined direction;
- said elements being provided with a means for applying a second, controlled, force therebetween;
- said method comprising:
- (a) measuring the displacement x.sub.rel of the second element relative to the first element, x.sub.rel being defined as zero at the equilibrium position;
- (b) calculating the relative velocity v.sub.rel of the two elements;
- (c) calculating an applied force F.sub.applied, defined as ##EQU25## where:
- v.sub.db is a velocity deadband with a preselected value greater than or equal to zero,
- m is the effective mass of the second element,
- d is the distance from the relative displacement to the acceptable extreme displacement limit x.sub.+limit or x.sub.-limit in the direction of the relative velocity v.sub.rel,
- k is the spring rate of the spring assembly at the relative displacement x.sub.rel
- F.sub.sys is the sum of the forces acting between the first and second elements other than the controlled force applied by the second force means,
- .zeta. is a number greater than or equal to 0 and less than or equal to 1;
- and
- (d) applying said force F.sub.applied between the first and second elements;
- provided that
- (i) if the direction of said force F.sub.applied is in the same direction as the relative velocity v.sub.rel, then said force F.sub.applied =0.
- (ii) if said force F.sub.applied is in direction opposite the relative velocity v.sub.rel, and greater than the maximum force F.sub.max that can be applied by the second force means in the direction of F.sub.applied, then F.sub.max is applied;
- whereby the force transmitted from the first element to the second element and the relative displacement between said elements are controlled.
15 more elements
A method for controlling the relative motion between two elements movably interconnected through a linkage which includes a spring assembly which tends to maintain the elements at an equilibrium position, at least the first element thereof being subjected to externally generated motion inputs and tending to transmit a first force in response thereto to the second element thereof;
- said elements being situated within extreme limits of acceptable displacement therebetween of x.sub.+limit in a positively defined direction and x.sub.-limit in a negatively defined direction;
- said elements being provided with a means for applying a second, controlled, force therebetween;
- said method comprising:
- (a) measuring (i) the displacement x.sub.rel of the second element relative to the first element, x.sub.rel being defined as zero at the equilibrium position, and (ii) the absolute acceleration of the second element;
- (b) calculating (i) the relative velocity v.sub.rel of the elements and (ii) the absolute velocity v.sub.abs of the second element;
- (c) calculating a force F.sub.applied defined as:
- ##EQU26## where:
- v.sub.db is a velocity deadband with a preselected value greater than or equal to zero,
- m is the effective mass of the second element.
- k is the spring rate of the spring assembly at the relative displacement x.sub.rel,
- d is the distance from the relative displacement to the acceptable extreme displacement limit x.sub.+limit of x.sub.-limit in the direction of the relative velocity v.sub.rel,
- F.sub.sys is the sum of the forces acting between the first and second elements other than the controlled force applied by the second force means,
- .zeta. is a number greater than 0.5 and less than 3;
- and
- (d) applying said force F.sub.applied between the first and second elements;
- provided that
- (i) if the direction of said force F.sub.applied is in the same direction as the relative velocity v.sub.rel, then said force F.sub.applied =0,
- (ii) if said force F.sub.applied is in direction opposite the relative velocity v.sub.rel, and greater than the maximum force F.sub.max that can be applied by the second force means in the direction of F.sub.applied, then F.sub.max is applied;
- whereby the force transmitted from the first element to the second element and the relative displacement between said elements are controlled.
16 more elements
A method for controlling the relative motion between two elements movably interconnected through a linkage which includes a spring assembly which tends to maintain the elements at an equilibrium position, at least the first element thereof being subjected to externally generated motion inputs and tending to transmit a first force in response thereto to the second element thereof;
- said elements being situated within extreme limits of acceptable displacement therebetween of x.sub.+limit in a positively defined direction and x.sub.-limit in a negatively defined direction;
- said elements being provided with a means for applying a second, controlled, force therebetween;
- said method comprising:
- (a) measuring (i) the displacement x.sub.rel of the second element relative to the first element, x.sub.rel being defined as zero at the equilibrium position, and (ii) the absolute acceleration of the second element;
- (b) calculating (i) the relative velocity v.sub.rel of the elements, (ii) the relative acceleration a.sub.rel of the elements, and (iii) the absolute velocity v.sub.abs of the second element;
- (c) calculating a force F.sub.applied defined as:
- ##EQU27## where:
- v.sub.db is a velocity deadband with a preselected value greater than or equal to zero,
- m is the effective mass of the second element,
- k is the spring rate of the spring assembly at the relative displacement x.sub.rel,
- d is the distance from the relative displacement to the acceptable extreme displacement limit x.sub.+limit or x.sub.-limit in the direction of the relative velocity v.sub.rel,
- F.sub.sys is the sum of the forces acting between the first and second elements other than the controlled force applied by the second force means,
- .zeta. is a number greater than 0.5 and less than 3.
- (d) applying said force F.sub.applied between the first and second elements;
- provided that
- (i) if the direction of said force F.sub.applied is in the same direction as the relative velocity v.sub.rel, then said force F.sub.applied =0,
- (ii) if said force F.sub.applied is in direction opposite the relative velocity v.sub.rel, and greater than the maximum force F.sub.max that can be applied by the second force means in the direction of F.sub.applied, then F.sub.max is applied;
- whereby the force transmitted from the first element to the second element and the relative displacement between said elements are controlled.
15 more elements
A device for controlling the relative motion between two elements movably interconnected through a linkage which includes a spring assembly which tends to maintain the elements at an equilibrium position, at least the first element thereof being subjected to externally generated motion inputs and tending to transmit a first force in response thereto to the second element thereof;
- said elements being provided with a means for applying a second, controlled, force therebetween;
- said device comprising:
- (A) an adjustable damper capable of applying a variable force F.sub.applied between said first and second elements;
- and
- (B) a controller adapted to send a control signal to said damper in response to the condition of the two movably interconnected elements, said control signal corresponding to a value of F.sub.applied ;
- wherein said control signal is determined by:
- (a) measuring the displacement x.sub.rel of the second element relative to the first element, x.sub.rel being defined as zero at the equilibrium position;
- (b) determining the relative velocity v.sub.rel between said first and second elements;
- (c) calculating a force F.sub.applied defined as:
- F.sub.applied =F.sub.calc -F.sub.sys
- where F.sub.calc is a force, calculated from knowledge of the position and motion of the elements, sufficient to prevent the relative motion of the elements from exceeding predetermined limits, and
- F.sub.sys is a nonzero sum of the forces acting between the first and second elements other than the controlled force applied by the second force means,
- provided that
- F.sub.applied =0 if said force F.sub.applied is in the same direction as the relative velocity v.sub.rel of the elements, or if .vertline.v.sub.rel .vertline..ltoreq.v.sub.db, where v.sub.db is a velocity deadband with a preselected value greater than or equal to zero, and
- F.sub.applied =F.sub.max if said force F.sub.applied is in direction opposite the relative velocity v.sub.rel of the elements, and greater than the maximum force F.sub.max that can be applied by the second force means in the direction of F.sub.applied.
12 more elements
A device for controlling the relative motion between two elements movably interconnected through a linkage which includes a spring assembly which tends to maintain the elements at an equilibrium position, at least the first element thereof being subjected to externally generated motion inputs and tending to transmit a first force in response thereto to the second element thereof;
- said elements having extreme limits of acceptable displacement therebetween of x.sub.+limit in a positively defined direction and x.sub.-limit in a negatively defined direction;
- said device comprising:
- (A) an adjustable damper capable of applying a variable force F.sub.applied between said first and second elements;
- and
- (B) a controller adapted to send a control signal to said damper in response to the condition of the two movably interconnected elements, said control signal corresponding to a value of F.sub.applied ;
- wherein said control signal is determined by:
- (a) measuring the displacement x.sub.rel of the second element relative to the first element, x.sub.rel being defined as zero at the equilibrium position;
- (b) calculating the (i) relative velocity v.sub.rel and (ii) relative acceleration a.sub.rel of the elements;
- and
- (c) calculating an applied force F.sub.applied, defined as ##EQU28## where:
- v.sub.db is a velocity deadband with a preselected value greater than or equal to zero,
- m is the effective mass of the second element,
- d is the distance from the relative displacement to the acceptable extreme displacement limit x.sub.+limit of x.sub.-limit in the direction of the relative velocity v.sub.rel,
- F.sub.sys is the sum of the forces acting between the first and second elements other than the controlled force applied by the second force means;
- provided that
- (i) if the direction of said force F.sub.applied is in the same direction as the relative velocity v.sub.rel, then said force F.sub.applied =0,
- (ii) if said force F.sub.applied is in direction opposite the relative velocity v.sub.rel, and greater than the maximum force F.sub.max that can be applied by the second force means in the direction F.sub.applied, then F.sub.max is applied.
14 more elements
A device for controlling the relative motion between two elements movably interconnected through a linkage which includes a spring assembly which tends to maintain the elements at an equilibrium position, at least the first element thereof being subjected to externally generated motion inputs and tending to transmit a first force in response thereto to the second element thereof;
- said elements having extreme limits of acceptable displacement therebetween of x.sub.+limit in a positively defined direction and x.sub.-limit in a negatively defined direction;
- said device comprising:
- (A) an adjustable damper capable of applying a variable force F.sub.applied between said first and second elements;
- and
- (B) a controller adapted to send a control signal to said damper in response to the condition of the two movably interconnected elements, said control signal corresponding to a value of F.sub.applied ;
- wherein said control signal is determined by:
- (a) measuring the displacement x.sub.rel of the second element relative to the first element, x.sub.rel being defined as zero at the equilibrium position;
- (b) calculating the relative velocity v.sub.rel of the two elements;
- (c) calculating an applied force F.sub.applied, defined as ##EQU29## where:
- v.sub.db is a velocity deadband with a preselected value greater than or equal to zero,
- m is the effective mass of the second element,
- d is the distance from the relative displacement to the acceptable extreme displacement limit x.sub.+limit or x.sub.-limit in the direction of the relative velocity v.sub.rel,
- F.sub.sys is the sum of the forces acting between the first and second elements other than the controlled force applied by the second force means;
- provided that
- (i) if the direction of said force F.sub.applied is in the same direction as the relative velocity v.sub.rel, then said force F.sub.applied =0
- (ii) if said force F.sub.applied is in direction opposite the relative velocity v.sub.rel, and greater than the maximum force F.sub.max that can be applied by the second force means in the direction of F.sub.applied, then F.sub.max is applied.
13 more elements
A device for controlling the relative motion between two elements movably interconnected through a linkage which includes a spring assembly which tends to maintain the elements at an equilibrium position, at least the first element thereof being subjected to externally generated motion inputs and tending to transmit a first force in response thereto to the second element thereof;
- said elements having extreme limits of acceptable displacement therebetween of x.sub.+limit in a positively defined direction and x.sub.-limit in a negatively defined direction;
- said device comprising:
- (A) an adjustable damper capable of applying a variable force F.sub.applied between said first and second elements;
- and
- (B) a controller adapted to send a control signal to said damper in response to the condition of the two movably interconnected elements, said control signal corresponding to a value of F.sub.applied ;
- wherein said control signal is determined by:
- (a) measuring the displacement x.sub.rel of the second element relative to the first element, x.sub.rel being defined as zero at the equilibrium position;
- (b) calculating the relative velocity v.sub.rel of the two elements;
- and
- (c) calculating an applied force F.sub.applied, defined as ##EQU30## where:
- v.sub.db is a velocity deadband with a preselected value greater than or equal to zero,
- m is the effective mass of the second element,
- d is the distance from the relative displacement to the acceptable extreme displacement limit x.sub.+limit or x.sub.-limit in the direction of the relative velocity v.sub.rel,
- F.sub.sys is the sum of the forces acting between the first and second elements other than the controlled force applied by the second force means,
- .zeta. is a number greater than or equal to 0 and less than or equal to 1;
- and
- provided that
- (i) if the direction of said force F.sub.applied is in the same direction as the relative velocity v.sub.rel, then said force F.sub.applied =0,
- (ii) if said force F.sub.applied is in direction opposite the relative velocity v.sub.rel, and greater than the maximum force F.sub.max that can be applied by the second force means in the direction of F.sub.applied, then F.sub.max is applied.
16 more elements
A device for controlling the relative motion between two elements movably interconnected through a linkage which includes a spring assembly which tends to maintain the elements at an equilibrium position, at least the first element thereof being subjected to externally generated motion inputs and tending to transmit a first force in response thereto to the second element thereof;
- said elements having extreme limits of acceptable displacement therebetween of x.sub.+limit in a positively defined direction and x.sub.-limit in a negatively defined direction;
- said device comprising:
- (A) an adjustable damper capable of applying a variable force F.sub.applied between said first and second elements;
- and
- (B) a controller adapted to send a control signal to said damper in response to the condition of the two movably interconnected elements, said control signal corresponding to a value of F.sub.applied ;
- wherein said control signal is determined by:
- (a) measuring (i) the displacement x.sub.rel of the second element relative to the first element, x.sub.rel being defined as zero at the equilibrium position, and (ii) the absolute acceleration of the second element;
- (b) calculating (i) the relative velocity v.sub.rel of the elements and (ii) the absolute velocity v.sub.abs of the second element;
- and
- (c) calculating a force F.sub.applied defined as:
- ##EQU31## where:
- v.sub.db is a velocity deadband with a preselected value greater than or equal to zero,
- m is the effective mass of the second element,
- k is the spring rate of the spring assembly at the relative displacement x.sub.rel,
- d is the distance from the relative displacement to the acceptable extreme displacement limit x.sub.+limit or x.sub.-limit in the direction of the relative velocity v.sub.rel,
- F.sub.sys is the sum of the forces acting between the first and second elements other than the controlled force applied by the second force means,
- .zeta. is a number greater than 0.5 and less than 3;
- provided that
- (i) if the direction of said force F.sub.applied is in the same direction as the relative velocity v.sub.rel, then said force F.sub.applied =0,
- (ii) if said force F.sub.applied is in direction opposite the relative velocity v.sub.rel, and greater than the maximum force F.sub.max that can be applied by the second force means, then F.sub.max is applied.
17 more elements
A device for controlling the relative motion between two elements movably interconnected through a linkage which includes a spring assembly which tends to maintain the elements at an equilibrium position, at least the first element thereof being subjected to externally generated motion inputs and tending to transmit a first force in response thereto to the second element thereof;
- said elements having extreme limits of acceptable displacement therebetween of x.sub.+limit in a positively defined direction and x.sub.-limit in a negatively defined direction;
- said device comprising:
- (A) an adjustable damper capable of applying a variable force F.sub.applied between said first and second elements;
- and
- (B) a controller adapted to send a control signal to said damper in response to the condition of the two movably interconnected elements, said control signal corresponding to a value of F.sub.applied ;
- wherein said control signal is determined by:
- (a) measuring (i) the displacement x.sub.rel of the second element relative to the first element, x.sub.rel being defined as zero at the equilibrium position, and (ii) the absolute acceleration of the second element;
- (b) calculating (i) the relative velocity v.sub.rel of the elements, (ii) the relative acceleration a.sub.rel of the elements, and (iii) the absolute velocity v.sub.abs of the second element;
- and
- (c) calculating a force F.sub.applied defined as:
- ##EQU32## where:
- v.sub.db is a velocity deadband with a preselected value greater than or equal to zero,
- m is the effective mass of the second element,
- k is the spring rate of the spring assembly at the relative displacement x.sub.rel,
- d is the distance from the relative displacement to the acceptable extreme displacement limit x.sub.+limit or x.sub.-limit in the direction of the relative velocity v.sub.rel,
- F.sub.sys is the sum of the forces acting between the first and second elements other than the controlled force applied by the second force means,
- .zeta. is a number greater than 0.5 and less than 3;
- provided that
- (i) if the direction of said force F.sub.applied is in the same direction as the relative velocity v.sub.rel, then said force F.sub.applied =0,
- (ii) if said force F.sub.applied is in direction opposite the relative velocity v.sub.rel, and greater than the maximum force F.sub.max that can be applied by the second force means in the direction of F.sub.applied, then F.sub.max is applied.
17 more elements
Dependencies are inferred from the claim text.