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EP-4739518-A1 - CONTROL DEVICE FOR ACTIVATING A SHOCK ABSORBER OF A MOTOR VEHICLE, COMPUTER PROGRAM PRODUCT, AND MOTOR VEHICLE

EP4739518A1EP 4739518 A1EP4739518 A1EP 4739518A1EP-4739518-A1

Abstract

A control device for activating a shock absorber of a motor vehicle is proposed, the control device being configured to activate a single-valve shock absorber in a first operating mode, the single-valve shock absorber having an individual control valve for the joint control of a tension stage and a compression stage of the single-valve shock absorber, and to activate a two-valve shock absorber in a second operating mode, the two-valve shock absorber having a first control valve for controlling a tension stage of the two-valve shock absorber and a second control valve for controlling a compression stage of the two-valve shock absorber. Furthermore, a computer program product for activating a two-valve shock absorber, having a first control valve and a second control valve, for a motor vehicle is proposed, comprising a first software module, which is designed to activate the first control valve of the two-valve shock absorber, and a second software module, which is designed to activate the second control valve of the two-valve shock absorber, characterized in that the first software module and the second software module are constructed identically or are identical, and furthermore comprising a third software module, which is designed to take into consideration a state of the second control valve of the two-valve shock absorber in the activation of the first control valve, and/or to take into consideration a state of the first control valve of the two-valve shock absorber in the activation of the second control valve.

Inventors

  • Schlegel, Jan-Rickmer
  • DE BEER, FRANK
  • KUKLA, STEFAN

Assignees

  • Volkswagen Aktiengesellschaft

Dates

Publication Date
20260513
Application Date
20240611

Claims (9)

  1. 1. Control device (44) for controlling a shock absorber (56, 58) of a motor vehicle (10), wherein the control device (44) is designed to control a single-valve shock absorber (56) in a first operating mode, wherein the single-valve shock absorber (56) has a single control valve (64) for jointly controlling a rebound stage and a compression stage of the single-valve shock absorber (56), and to control a two-valve shock absorber (58) in a second operating mode, wherein the two-valve shock absorber (58) has a first control valve (66) for controlling a rebound stage of the two-valve shock absorber (58) and a second control valve (68) for controlling a compression stage of the two-valve shock absorber (58), wherein a first software module (72) is stored in the control device (44), wherein the control device (44) is designed to use the first software module (72) to control the individual valve (64) of the Single-valve shock absorber (56) in the first operating mode, and wherein the control device (44) is designed to use the first software module (72) or a copy of the first software module (72) in the second operating mode to control a first valve (66) of the two-valve shock absorber (58).
  2. 2. Control device (44) according to claim 1, characterized in that the control device (44) is designed to control/regulate a fluid cross-section of the individual valve (64) of the single-valve shock absorber (56) in the first operating mode depending on an input variable and a fluid cross-section of the first valve (66) of the two-valve shock absorber (58) and a fluid cross-section of the second valve (68) of the two-valve shock absorber (58) in the second operating mode depending on an input variable
  3. 3. Control device (44) according to claim 1, characterized in that a second software module (76) is present in the control device (44), wherein the second software module (76) is a copy of the first software module (72) and wherein the control device (44) is designed to use the second software module (76) in the second operating mode for controlling a second valve (68) of the two-valve shock absorber (58).
  4. 4. Control device (44) according to claim 3, characterized in that a third software module (78) is present in the control device (44), the third Software module (78) is designed to take into account a state of the second control valve (68) of the two-valve shock absorber (58) in the second operating mode when controlling the first control valve (66) of the two-valve shock absorber (58) and/or to take into account a state of the first control valve (66) of the two-valve shock absorber (58) when controlling the second control valve (68) of the two-valve shock absorber (58).
  5. 5. Control device (44) according to claim 4, characterized in that the third software module (78) is configured to limit a difference between a control current of the first control valve (66) of the two-valve shock absorber (58) and a control current of the second control valve (68) of the two-valve shock absorber (58).
  6. 6. Control device (44) according to claim 5 or 5, characterized in that the third software module (78) is set up to take into account a condition of a surface on which the motor vehicle (10) is driving and/or an active driving profile as input variables for controlling the first control valve (66) of the two-valve shock absorber (58) and/or the second control valve (68) of the two-valve shock absorber (58).
  7. 7. Control device (44) according to claim 6, characterized in that the control device (44) is designed to allow an operating state in the second operating mode in which both the first control valve (66) of the two-valve shock absorber (58) and the second control valve of the two-valve shock absorber (58) are at least partially open.
  8. 8. Computer program product for controlling a two-valve shock absorber (58) for a motor vehicle, said two-valve shock absorber having a first control valve (66) and a second control valve (68), comprising a first software module (72) which is designed to control the first control valve (68) of the two-valve shock absorber (58), and a second software module (76) which is designed to control the second control valve of the two-valve shock absorber (58), characterized in that the first software module (72) and the second software module (76) are constructed in the same way or are identical, and further comprising a third software module (78) which is designed to take into account a state of the second control valve (68) of the two-valve shock absorber (58) when controlling the first control valve (66) of the two-valve shock absorber (58) and/or to take into account a state of the first control valve (66) of the two-valve shock absorber (58) must be taken into account.
  9. 9. Motor vehicle with a control device (44) according to one of claims 1 to 7 or with a data storage device on which a computer program product according to claim 8 is stored.

Description

Description Control device for controlling a shock absorber of a motor vehicle, computer program product and motor vehicle The invention relates to a control device for controlling a shock absorber of a motor vehicle, a computer program product for controlling a shock absorber for a motor vehicle having a first control valve and a second control valve, and a motor vehicle. For reasons of comfort and driving safety, every motor vehicle has a shock absorber system. There are essentially three known shock absorber systems for vehicles, each of which has an actuator connected in parallel to a spring arrangement between the wheel and the body. Passive, semi-active and active shock absorber systems are known. In passive shock absorber systems, a change in the shock absorber force during driving is not provided. In semi-active shock absorber systems, the shock absorber force can be changed by changing an oil fluid flow using a valve. In this way, the damping properties can be changed. Semi-active shock absorber systems work purely by absorbing energy. In active shock absorber systems, a desired shock absorber force can be provided in any direction, both damping and introducing energy. The valves or control valves can be so-called pilot valves. By applying and varying a control current, the fluid flow through the valve and thus also the damper characteristic can be influenced. In particular, the current damper hardness can be set or regulated. The model of a so-called "skyhook" controller is widely used. This approach is based on the idea that the suspension comfort is optimal when the oscillating structure is dampened not against the uneven road but against the sky. In a thought experiment, the vibration damper is not placed between the structure and the wheel but between the structure and a hook in the sky. In this thought experiment, the real shock absorber should then apply the same force as the skyhook damper. If semi-active shock absorbers are used, i.e. shock absorbers that are passive but whose damping constant is adjustable, the aim is to keep the effect of the shock absorber low if, due to the forces of the wheel, the shock absorber is effective on the structure in the same direction in which the structure is currently moving. This is to prevent the movement of the body from being further accelerated by the force acting on the shock absorber. Conversely, if the two directions mentioned are in opposite directions, the shock absorber is set hard to slow down the movement of the body. The Skyhook control minimizes the speed of the body to a large extent and very quickly. The key element of the Skyhook model is the determination of the force required to calm the body. A shock absorber force map is also essential, which estimates a target current from this force, taking into account the current shock absorber speed. These maps must be stored in the control units or control devices so that a target current can be determined at any time from the required target force and the determined actual damper speed. With the Skyhook principle, the controller regulates a force as a manipulated variable at the output. This must be converted into a corresponding current for the shock absorber using a map of characteristics, taking into account the relative speed of the shock absorber in relation to the body of the vehicle. There are shock absorbers with one control valve as well as shock absorbers with two control valves. If there is only one control valve, both the rebound and compression stages are regulated simultaneously using the one control valve. With a shock absorber with two control valves, the rebound and compression stages can be regulated independently of each other. This creates another parameter for active chassis tuning, which can improve roadholding and/or improve comfort for the vehicle occupants. Control software is required to control the control valves, which is usually implemented or stored on a control unit or control device, whereby the control unit is designed to execute the control software. The control software calculates a control current from input variables to set a desired damper hardness. The input variables can be formed from various sensor signals and can in particular include the aforementioned movement states of the so-called structure and the wheels as well as the associated forces acting. The structure can in particular be understood to mean all components carried by the chassis, such as the body and the drive of the motor vehicle. The development and maintenance of such control software is complex and costly. It is therefore the object of the present invention to provide a way of developing and maintenance of a control software for controlling a shock absorber for a motor vehicle and to make it more cost-efficient. The object is achieved by a control device for controlling a shock absorber of a motor vehicle, wherein the control device is designed to control a single-valve shock absorb