# US 10,500,917 B2 · Method and control device for adjusting the damping force of a shock absorber > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,500,917 B2 - Document ID: US10500917B2 - Status: Granted - Kind: B2 - Application number: 15/814,641 - Filed: 2017-11-16 - Published: 2018-06-07 - Granted: 2019-12-10 - Earliest claimed: 2016-12-05 - Assignees: Dr. Ing. h.c. F. Porsche Aktiengesellschaft - Applicants: Dr. Ing. h.c. F. Porsche Aktiengesellschaft - Inventors: Jochen Liebold; David Caredda - Web page: https://patentgrep.com/patent/US10500917B2 ## CPC - B60G 17/06: Characteristics of dampers {, e.g. mechanical dampers}(B60G17/015 takes precedence) - B60G 2400/0511: Roll angle - B60G 2400/0512: Pitch angle - B60G 2400/252: vertical - B60G 2400/60: Load - B60G 2500/10: Damping action or damper - B60G: VEHICLE SUSPENSION ARRANGEMENTS (air-cushion vehicles B60V; {cycle suspensions B62K25/00}) ## Abstract A method for adjusting the damping force of shock absorbers, connected between a vehicle body and a wheel at vehicle corners of a motor vehicle, wherein at least one damping force which is referred to a center of gravity of the vehicle body and which is divided between the shock absorbers of the respective wheels of the motor vehicle is determined as a function of at least one variable which represents the movement of the vehicle body and/or a movement of the respective wheel. For at least one of the lifting, pitching and rolling modal directions, the respective damping force is determined as a function of a predefined, constantly maintained degree of damping of respective modal direction. ## Claims ### Claim 1 A method for adjusting a damping force of shock absorbers connected between a vehicle body and a wheel at vehicle corners of a motor vehicle, the method comprising the steps of: determining at least one damping force (FLIFT, FPITCH, FROLL), which is referred to a center of gravity of a vehicle body, and which is divided between shock absorbers of the respective wheels of the motor vehicle as a function of at least one variable which represents a movement of the vehicle body or a movement of the respective wheel, determining, for at least one of the lifting, pitching and rolling modal directions, the respective damping force (FLIFT, FPITCH, FROLL) as a function of a predefined, constantly maintained degree of damping of the respective modal direction, wherein, for the lifting modal direction, the degree of damping for the lifting modal direction is kept constant, in that a damping constant for the lifting modal direction is adapted as a function of a changing lifting-spring stiffness or changing mass of the motor vehicle, with the result that the degree of damping for the lifting modal direction remains constant, and wherein the damping constant dLIFT for the lifting modal direction is adapted in such a way that the degree of damping DLIFT remains constant according to the equation: D LIFT = d LIFT 2 ⁢ c LIFT ⁢ m , where DLIFT is the degree of damping for the lifting modal direction, dLIFT is the damping constant for the lifting modal direction, cLIFT is the lifting-spring stiffness, and m is the mass. ### Claim 2 (depends on 1) The method as claimed in claim 1, wherein, for all the lifting, pitching and rolling modal directions, the respective damping force (FLIFT, FPITCH, FROLL) is determined as a function of a predefined, constantly maintained degree of damping of the corresponding modal direction. ### Claim 3 (depends on 1) The method as claimed in claim 1, wherein the damping constant for the lifting modal direction is calculated in a continuously updated fashion. ### Claim 4 (depends on 1) The method as claimed in claim 1, wherein for the pitching modal direction, the degree of damping is kept constant in such a way that a damping constant for the pitching modal direction is adapted as a function of a changing pitching-spring stiffness or a changing pitching moment of mass inertia of the motor vehicle, with the result that the degree of damping for the pitching modal direction remains constant. ### Claim 5 (depends on 1) The method as claimed in claim 1, wherein, for the rolling modal direction, the degree of damping is kept constant in such a way that a damping constant for the rolling modal direction is adapted as a function of a changing rolling-spring stiffness or a changing rolling-moment of mass inertia of the motor vehicle, with the result that the degree of damping for the rolling modal direction remains constant. ### Claim 6 A method for adjusting a damping force of shock absorbers connected between a vehicle body and a wheel at vehicle corners of a motor vehicle, the method comprising the steps of: determining at least one damping force (FLIFT, FPITCH, FROLL), which is referred to a center of gravity of a vehicle body, and which is divided between shock absorbers of the respective wheels of the motor vehicle as a function of at least one variable which represents a movement of the vehicle body or a movement of the respective wheel, determining, for at least one of the lifting, pitching and rolling modal directions, the respective damping force (FLIFT, FPITCH, FROLL) as a function of a predefined, constantly maintained degree of damping of the respective modal direction, wherein for the pitching modal direction, the degree of damping is kept constant in such a way that a damping constant for the pitching modal direction is adapted as a function of a changing pitching-spring stiffness or a changing pitching moment of mass inertia of the motor vehicle, with the result that the degree of damping for the pitching modal direction remains constant, and wherein the damping constant dPITCH for the pitching modal direction is adapted in such a way that the degree of damping DPITCH remains constant and according to the equation: D PITCH = d PITCH 2 ⁢ c PITCH ⁢ J PITCH , where DPITCH is the degree of damping for the pitching modal direction, dPITCH is the damping constant for the pitching modal direction, cPITCH is the pitching-spring stiffness, and JPITCH is the pitching moment of mass inertia. ### Claim 7 (depends on 6) The method as claimed in claim 6, wherein the damping constant for the pitching modal direction is calculated in a continuously updated fashion. ### Claim 8 A method for adjusting a damping force of shock absorbers connected between a vehicle body and a wheel at vehicle corners of a motor vehicle, the method comprising the steps of: determining at least one damping force (FLIFT, FPITCH, FROLL), which is referred to a center of gravity of a vehicle body, and which is divided between shock absorbers of the respective wheels of the motor vehicle as a function of at least one variable which represents a movement of the vehicle body or a movement of the respective wheel, determining, for at least one of the lifting, pitching and rolling modal directions, the respective damping force (FLIFT, FPITCH, FROLL) as a function of a predefined, constantly maintained degree of damping of the respective modal direction, wherein, for the rolling modal direction, the degree of damping is kept constant in such a way that a damping constant for the rolling modal direction is adapted as a function of a changing rolling-spring stiffness or a changing rolling-moment of mass inertia of the motor vehicle, with the result that the degree of damping for the rolling modal direction remains constant, and wherein the damping constant dROLL for the rolling modal direction is adapted in such a way that the degree of damping DROLL remains constant and according to the equation: D ROLL = d ROLL 2 ⁢ c ROLL ⁢ J ROLL , wherein DROLL is the degree of damping for the rolling modal direction, dROLL is the damping constant for the rolling modal direction, cROLL is the rolling-spring stiffness, and JROLL is the rolling moment of mass inertia. ### Claim 9 (depends on 8) The method as claimed in claim 8, wherein the damping constant for the rolling modal direction is calculated in a continuously updated fashion. ### Claim 10 A control device for adjusting a damping force of shock absorbers which are connected between a vehicle body and a respective wheel at vehicle corners of the motor vehicle, wherein said control device is configured to: determine at least one damping force (FLIFT, FPITCH, FROLL), which is referred to a center of gravity of the vehicle body, and which is divided between the shock absorbers of the respective wheels of the motor vehicle as a function of at least one variable which represents a movement of the vehicle body or a movement of the respective wheel, and determine, for at least one of the lifting, pitching and rolling modal directions, the respective damping force (FLIFT, FPITCH, FROLL) as a function of a predefined, constantly maintained degree of damping of the respective modal direction, wherein, for the lifting modal direction, the degree of damping for the lifting modal direction is kept constant, in that a damping constant for the lifting modal direction is adapted as a function of a changing lifting-spring stiffness or changing mass of the motor vehicle, with the result that the degree of damping for the lifting modal direction remains constant, and wherein the damping constant dLIFT for the lifting modal direction is adapted in such a way that the degree of damping DLIFT remains constant according to the equation: D LIFT = d LIFT 2 ⁢ c LIFT ⁢ m , where DLIFT is the degree of damping for the lifting modal direction, dLIFT is the damping constant for the lifting modal direction, cLIFT is the lifting-spring stiffness, and m is the mass.