Controlling dampers in suspension systems

Abstract

Aspects of the present invention relate to a control system (100) for controlling at least one damper (500) of a suspension system (550) of an automotive vehicle (300), a system (310) comprising the control system, a method (400) for controlling at least one damper of a suspension system of an automotive vehicle, an automotive vehicle, and computer readable instructions. The control system is for controlling at least one damper of a suspension system of an automotive vehicle, wherein the suspension system being operable at a plurality of ride heights. The control system comprises one or more processors (120) collectively configured to receive a ride height signal, (165, 210) the ride height signal being indicative of a selected suspension height of the automotive vehicle; determine that an operating damping parameter (212a, 212b, 212c, 212d) has passed a threshold; in dependence on the determination that the operating damping parameter has passed the threshold, determine a damping force in dependence on the received ride height signal; and output, to the at least one damper, a damper signal (155, 215) indicative of the determined damping force.

Description

[0001] CONTROLLING DAMPERS IN SUSPENSION SYSTEMS

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to controlling dampers in suspension systems. Aspects of the invention relate to a control system, to a system, to a vehicle, to a method and to computer program instructions.

[0004] BACKGROUND

[0005] It is known to provide a vehicle with a suspension system that can be adjusted to provide different ride heights and that has adaptive damping. Adaptive damping is a technology which is used to automatically adjust the stiffness of dampers (for example shock absorbers) in response to varying driving conditions. For example, a vehicle can have different drive modes which have associated ride heights and settings for the dampers, and the vehicle is configured to control the level of damping of the dampers in accordance with the settings associated with the selected drive mode. For example in an “off-road mode”, the ride height may be set higher to increase ground clearance and the suspension system may be controlling the dampers to be softer, allowing for more absorption of road imperfections and reducing vibrations transmitted to the cabin, resulting in a smooth and comfortable ride. In contrast, in a “sport mode”, the ride height may be lowered to improve aerodynamics and the suspension system may control the level of damping of the dampers to be stiffer, resulting in a firmer ride where body roll is reduced and the vehicle’s handling is enhanced.

[0006] Additionally, adaptive damping may comprise adjusting the stiffness of the dampers in real-time in response to a durability event where the dampers are displaced into an extreme compression and / or rebound state at a high damper velocity. This adjustment of stiffness is to protect the dampers from being rapidly compressed or extended which may reduce the longevity of the dampers and the suspension system.

[0007] It is an aim of the present invention to address one or more of the disadvantages associated with the prior art.

[0008] SUMMARY OF THE INVENTION

[0009] Aspects and embodiments of the invention provide a control system for controlling at least one damper of a suspension system of an automotive vehicle, a system comprising such a control system, an automotive vehicle, a method for controlling at least one damper of a suspension system of an automotive vehicle, and computer readable instructions as claimed in the appended claims.

[0010] According to an aspect of the present invention there is provided a control system for controlling at least one damper of a suspension system, the control system comprising one or more processors collectively configured to: receive a ride height signal, the ride height signal being indicative of a suspension height; determine that an operating damping parameter has passed a threshold; in dependence on the determination that the operating damping parameter has passed the threshold, determine a damping force in dependence on the received ride height signal; and output, to the at least one damper, a damper signal indicative of the determined damping force. Advantageously, by determining a damping force in dependence on a ride height when a threshold has passed, the damping force is tuned to the ride height such that the dampers are less likely to enter an extreme compressed and / or extended state in a durability event.

[0011] According to an aspect of the present invention there is provided a control system for controlling at least one damper of a suspension system of an automotive vehicle, the suspension system being operable at a plurality of ride heights, the control system comprising one or more processors collectively configured to: receive a ride height signal, the ride height signal being indicative of a selected suspension height of the automotive vehicle; determine that an operating damping parameter has passed a threshold; in dependence on the determination that the operating damping parameter has passed the threshold, determine a damping force in dependence on the received ride height signal; and output, to the at least one damper, a damper signal indicative of the determined damping force.

[0012] Advantageously, by determining a damping force in dependence on a ride height when a threshold has passed, the damping force is tuned to the ride height of the vehicle such that the dampers are less likely to enter an extreme compressed and / or extended state in a durability event.

[0013] The control system comprises one or more controllers collectively comprising at least one electronic processor having an electrical input for receiving an input signal; and at least one memory device electrically coupled to the at least one electronic processor and having instructions stored therein; and wherein the at least one electronic processor is configured to access the at least one memory device and execute the instructions thereon so as to: receive a ride height signal, the ride height signal being indicative of a selected suspension height of the automotive vehicle; determine that an operating damping parameter has passed a threshold; in dependence on the determination that the operating damping parameter has passed the threshold, determine a damping force in dependence on the received ride height signal; and output, to the at least one damper, a damper signal indicative of the determined damping force.

[0014] Advantageously, by determining a damping force in dependence on a ride height when a threshold has passed, the damping force is tuned to the ride height of the vehicle such that the dampers are less likely to enter an extreme compressed and / or extended state in a durability event.

[0015] Optionally, the determining of the damping force is further in dependence on the operating damping parameter.

[0016] Advantageously, by also determining the damping force based on the operating damping parameter, as well as the ride height, the damping force can be further tuned. For example, if the damping operating parameter comprises an operating damper velocity, then a damping force can be tuned to a higher operating damping velocity which will require a higher damping force than a lower operating damping velocity. Optionally, the operating damping parameter may be an operating damper length and operating damper velocity of the at least one damper. The operating damper length and the operating damper velocity may be considered to be the damper length and damper velocity in real-time.

[0017] Advantageously, by determining the damping force based on the operating damper length and operating damper velocity, as well as the ride height, a more accurate damping force will be determined that protects the damper as well as providing the user with a comfortable driving experience.

[0018] Optionally, the threshold may be considered an operating damping parameter threshold and it may correspond to a damper length or damper velocity. In one embodiment, the passing of the threshold triggers the damping force to be determined. In other words, the passing of the threshold corresponds to a durability event, as described herein, being detected. In an alternative embodiment, a damping force is continuously or repeatedly determined, however the damping force is zero Newtons (N) unless the threshold has been passed at which point the damping force is determined to have a value other than zero N, e.g. a positive or a negative value. The value of the damping force being a value other than zero N is indicative that a durability event, as described herein, has been detected.

[0019] Advantageously, by requiring a threshold to be passed in order for a damping force to be determined as described herein, the damping force is only applied when required. For example, in the event of a durability event.

[0020] Optionally, the determining of the damping force comprises selecting, in dependence on the ride height signal, a mapping between the operating damping parameter and the damping force and determining the damping force using the selected mapping.

[0021] Advantageously, by the mapping matching the operating damping parameter with the damping force, the damping force can be quickly determined by the control system looking it up in the mapping based on the operating damping parameter.

[0022] Optionally, the determining of the damping force comprises selecting a mapping between the operating damping parameter and the damping force out of a plurality of mappings each of which is associated with different ride heights.

[0023] Advantageously, by having a plurality of mappings, each of which is associated with different ride heights, the control system can quickly determine or switch to the correct mapping based on the selected ride height and retrieve the appropriate damping force.

[0024] Optionally, the mapping may comprise an algorithm configured to repeatedly receive the operating damper parameters and repeatedly determine the damping force. Advantageously, by each mapping repeatedly receiving the operating damper parameters and repeatedly determining the damping force, a damping force can be repeatedly outputted. In this example, the damping force may have a value of zero, and change to a positive or negative damping force upon the threshold being passed.

[0025] Optionally, the damping force for each plurality of ride height, or mappings, is determined at least every 2ms.

[0026] Advantageously, by determining the damping force every 2ms, the damping force will counteract forces impacted on the at least one damper in real-time.

[0027] Optionally, the one or more processors are configured to generate a switch value based on the received ride height signal. The switch value is indicative of the determined damping force the one or more processor is to select.

[0028] Advantageously, by having a switch value, the one or more processor can rapidly switch from one mapping to another so as to output the damper signal comprising a damping force suitable for the selected ride height.

[0029] Optionally, the one or more processors are configured select a damping force based on the received switch value, and output the selected damping force to the at least one damper.

[0030] Advantageously, the one or more processor can rapidly select a damping force based on the switch value so as to output the damper signal comprising a damping force suitable for the selected ride height.

[0031] According to another aspect of the present invention, a system is provided comprising the control system described above and further comprising at least one ride height sensor, and the control system is configured to use the at least one ride height sensor to obtain the at least one ride height signal.

[0032] Advantageously, by using a ride height sensor to obtain the ride height signal, the ride height signal can be fed to the control system so as to determine a damping force as described herein.

[0033] Optionally, the system further comprises at least one damper sensor configured to sense a damper length and damper velocity of the at least one damper, and send the sensed length and velocity to the one or more processors as an operating damping parameter.

[0034] Advantageously, by sensing the least one damper length and velocity, the state or configuration of the damper can be continuously monitored and the damping force can be tuned accordingly.

[0035] According to yet another aspect, an automotive vehicle is provided comprising a control system or a system as described in any of the preceding paragraphs. According to a further aspect, there is provided a method for operating at least one damper of a suspension system of an automotive vehicle, the suspension system being operable at a plurality of ride heights, the method comprising: receiving at least one ride height signal, each of the at least one ride height signal being indicative of a wheel displacement of a corresponding wheel of the automotive vehicle compared to a body of the automotive vehicle; determining a damping force for each of the plurality of ride heights when an operating damping parameter exceeds a threshold, selecting a damping force based on the received ride height signal, and outputting the selected damping force to the at least one damper.

[0036] Advantageously, by determining a damping force in dependence on a ride height when a threshold has passed, the damping force is tuned to the ride height of the vehicle such that the dampers are less likely to enter an extreme compressed and / or extended state in a durability event.

[0037] Optionally, the determining of the damping force comprises selecting, in dependence on the ride height signal, a mapping between the operating damping parameter and the damping force and determining the damping force using the selected mapping.

[0038] Advantageously, by the mapping matching the operating damping parameter with the damping force, the damping force can be quickly determined by the control system looking it up in the mapping based on the operating damping parameter.

[0039] Optionally, the determining of the damping force comprises selecting a mapping between the operating damping parameter and the damping force out of a plurality of mappings each of which is associated with different ride heights.

[0040] Advantageously, by having a plurality of mappings, each of which is associated with different ride heights, the control system can quickly determine or switch to the correct mapping based on the selected ride height and retrieve the appropriate damping force.

[0041] According to yet another aspect of this invention, there is provided computer readable instructions which, when executed by one or more processors, cause the one or more processors to perform the method as described herein.

[0042] According to yet another aspect of this invention, there is provided a non-transitory, computer-readable storage medium storing instructions thereon that, when executed by one or more processors of a control cause the one or more electronic processors to carry out a method as described herein.

[0043] Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and / or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and / or features of any embodiment can be combined in any way and / or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and / or incorporate any feature of any other claim although not originally claimed in that manner.

[0044] BRIEF DESCRIPTION OF THE DRAWINGS

[0045] One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0046] Figure 1 shows a block diagram of a control system for a damper in accordance with an embodiment of the invention;

[0047] Figure 2 shows an implementation of the control system of Figure 1 ;

[0048] Figure 3 illustrates a vehicle in accordance with an embodiment of the invention;

[0049] Figure 4 illustrates a method in accordance with an embodiment of the invention; and

[0050] Figure 5 illustrates a suspension system and damper in accordance with an embodiment of the invention.

[0051] DETAILED DESCRIPTION

[0052] As set out in the background section, the height of the suspension system of a vehicle, referred to as ride height, may be varied depending on drive mode. For example, in “sport mode” the ride height may be lowered to improve the vehicle’s aerodynamic properties, whereas in “comfort mode” or “off-road mode” the ride height may be higher to increase ground clearance and shock absorbing capabilities.

[0053] Furthermore, the suspension system may comprise adaptive damping. The adaptive damping is used to automatically adjust the stiffness of dampers of the suspension system in response to varying driving conditions. In particular, adaptive damping may comprise adjusting the stiffness of the dampers in real-time in response to a durability event where the dampers are displaced into an extreme compression and / or rebound state at a high damper velocity. This adjustment in stiffness is to protect the dampers from being rapidly compressed or extended into an extreme state which may reduce the longevity of the dampers and / or the wider suspension system. The adjustment in stiffness is only intended to be applied when required, in other words upon detection of a durability event.

[0054] However, the adjustment of stiffness during a durability event is typically based on a single ride height which may not be sufficient for other ride heights.

[0055] Embodiments of the present disclosure relate to determining a damping force of at least one damper during a durability event in dependence on a ride height. The term “durability event” as used herein should be understood to mean when an operating damping parameter of a damper, such as damper length and / or damper velocity, passes a threshold indicative of potential risk of damage to the damper.

[0056] According to an embodiment of the invention, a control system is provided which is for controlling at least one damper of a suspension system of an automotive vehicle. The suspension system is operable at a plurality of ride heights. The control system comprises one or more processors collectively configured to: receive a ride height signal, the ride height signal being indicative of a selected suspension height of the automotive vehicle; determine that an operating damping parameter has passed a threshold; in dependence on the determination that the operating damping parameter has passed the threshold, determine a damping force in dependence on the received ride height signal; and output, to the at least one damper, a damper signal indicative of the determined damping force.

[0057] Figure 1 shows a control system 100 for controlling at least one damper of a suspension system of an automotive vehicle. The automotive vehicle may be a wheeled vehicle, such as an automobile, or may be another type of vehicle. The control system 100 controls the stiffness or damping force of the at least one damper. The at least one damper may form part of a suspension system that has adaptive damping capabilities as described above.

[0058] The control system 100 comprises one controller 110, although in other examples there may be plural controllers. The control system 100 comprises processing means 120 and memory means 130. The processing means 120 may be one or more electronic processing device 120 which operably executes computer-readable instructions. The memory means 130 may be one or more memory device 130. The memory means 130 is electrically coupled to the processing means 120. The memory means 130 is configured to store instructions, and the processing means 120 is configured to access the memory means 130 and execute the instructions stored thereon.

[0059] The control system 100 comprises an input means 140 and an output means 150. The input means 140 may comprise an electrical input of the control system 100. The output means 150 may comprise an electrical output of the control system 100. The input 140 is arranged to receive an input signal 165 comprising a ride height signal from one or more ride height sensors and at least one operating damping parameter from one or more damper sensors. The ride height signal is indicative of a selected suspension height of the automotive vehicle and the operating damping parameter(s) may be an operating damper length and / or damper velocity. The control system 110 is configured to determine if the operating damping parameter(s) has passed a threshold, and in dependence on the determination that the operating damping parameter(s) has passed the threshold, the control system is further configured to determine a damping force in dependence on the received ride height signal 165. The output 150 is arranged to output a damper signal 155 indicative of the determined damping force. The determined damping force is for controlling the stiffness of at least one damper when the received operating damping parameter(s) has passed a threshold.

[0060] Advantageously, by determining a damping force in dependence upon a ride height and an operating damping parameter having passed a threshold, the damping force improves protection of the damper from potential damage compared to a damping force that is not tailored to the ride height.

[0061] As described above, the operating damping parameter(s) may be an operating damper length and / or a operating damper velocity of a damper. That is, a damper length and / or a damper velocity in real-time or near real-time. In one example, the operating damping parameter(s) may be an operating damper length and / or an operating damper velocity of a plurality of dampers in real-time such that a damping force is determined for each damper or a combination of dampers. The threshold may be considered an operating damping parameter threshold and it may correspond to a damper length or damper velocity. In one example, the threshold comprises two thresholds, one for damper length and one for damper velocity, both of which are required to have been passed.

[0062] The passing of the threshold may trigger a damping force to be determined. In other words, the passing of the threshold corresponds to a durability event being detected as described herein. Alternatively, a damping force is continuously or repeatedly determined but it is zero Newtons (N) unless a threshold has been passed. In this case, the passing of the threshold triggers a damping force to be determined which has a value other than zero N. The value of the damping force being a value other than zero N is indicative that a durability event, as described herein, being detected. The threshold described herein may be associated with compression and / or extension of the damper and / or a damper velocity.

[0063] In one example, the control system 100 may determine the damping force not only based on the ride height but also in dependence on at least one operating damping parameter received through input signal 165. This operating damping parameter(s) may be a damper length and / or a damper velocity for a damper or for a plurality of dampers as described above. Furthermore, it may be the same as the operating damper length and / or operating damper velocity used for comparison against the threshold or it may be a different damper length and / or damper velocity. Nevertheless, the operating damping parameter(s) is inputted into a plurality of mappings of the control system 100, wherein each mapping maps an operating damping parameter with a damping force. Furthermore, each mapping is associated with a specific ride height. For example, a first ride height may be associated with a first mapping, a second ride height may be associated with a second mapping and a third ride height may be associated with a third mapping. Thus, a damping force can be determined by looking it up in the mapping based on the operating damping parameter, wherein the mapping used is selected based on the ride height received in the ride height signal 165. The output from the mapping is the damping force that is mapped or associated with the inputted operating damping parameter.

[0064] As described above, each mapping of the plurality of mappings may be continuously or repeatedly receiving inputs comprising operating damping parameter(s) as described herein, and continuously or repeatedly outputting a damping force that is associated with the inputted operating damping parameter(s). This means that a damping force in dependence on each ride height is continuously or repeatedly determined, and the control system 100 can select the relevant damping force based on the received ride height signal 165. In these examples, the threshold relates to an operating damping parameter passing said threshold such that a damping force is generated having a value other than zero N.

[0065] When the damping force is continuously or repeatedly determined, this may occur at least every 10ms, 5ms, 2ms or 1 ms. As described above, in some cases, a zero N damping force is determined which is indicative of that the stiffness of the damper does not need to be adjusted. In one example, a damping force having a value other than zero N is determined which is indicative of that the stiffness of the damper needs to be adjusted to protect the damper. The mappings may comprise a look-up table or an algorithm. If an algorithm, the algorithm receives the operating damping parameter(s), and when executed, determines and outputs a damping force. Each mapping is different to one another and is tailored or bespoke to the ride height that it is associated with.

[0066] As described herein, the control system 100 is configured to receive the input signal 165 comprising at least a ride height signal. In one example, the control system 100 may be configured to determine a switch value based on the received ride height signal. The switch value is indicative of the required mapping associated with the received ride height signal. For example, the ride height signal may comprise information representative of an “off-road mode”. The control system 100 then determines a switch value based on the information, for example, 1 , 2 or 3, wherein each of 1 , 2 and 3 correspond to a specific mapping. The control system then proceeds to select the relevant mapping based on the switch value.

[0067] Example implementations of the control system of Figure 1 will now be described with reference to Figure 2.

[0068] Figure 2 illustrates an control system 200 in accordance with an embodiment of the invention. Although not illustrated in Figure 2, it should be understood that control system 200 comprises an input and an output similar to the control system 100. The control system further comprises a selection means 205 which may be a selection unit and a plurality of mappings 206a, 206b, 206c. The control system may further comprise switching means 207 which may be a switch logic. These features will now be described in more detail.

[0069] The selection means 205 is configured to select a mapping of the plurality of mappings 206a, 206b, 206c based on a received ride height signal 210. Thereafter, based on the selection, receive or fetch a damping force signal 211 a, 211 b, 211 c comprising at least one damping force from the selected mappings 206a, 206b, 206c and output a damper signal 215 comprising the selected damping force to at least one damper of a suspension system. The at least one damping force may comprise a damping force for both compression of the damper and rebound of the damper. According to examples, the damping force for compression and rebound of the damper is the same. In other examples, the damping force for compression and rebound may be different. It should be understood that the ride height signal 210 may form part of the input signal 165 of Figure 1 .

[0070] The plurality of mappings 206a, 206b, 206c may correspond to the mappings described with reference to Figure 1. Each mapping 206a, 206b, 206c maps received operating damping parameter(s) 212a, 212b, 212c, 212d with a damping force and outputs the damping force through a damping force signal 211a, 211 b, 211 c to the selection means 205. Each damping force signal 211 a, 211 b, 211 c may comprise a damping force for a single damper, some or all dampers. It should be understood that the received operating damping parameter(s) 212a, 212b, 212c, 212d may form part of the input signal 165 of Figure 1 . The operating damping parameter 212a and 212b may correspond to a damper length and a damper velocity, respectively, of a front left and front right damper, and the operating damping parameter 212c and 212d may correspond to a damper length and a damper velocity, respectively, of a back left and back right damper. Each mapping 206a, 206b, 206c may comprise two sub-mappings 230a, 230b. A first sub-mapping 230a of the two submappings may be configured to map the operating damping parameters 212a, 212b with a damping force for the front left and right dampers, and the second sub-mapping 230b may be configured to map the operating damping parameters 212c, 212d with a damping force for the rear left and right dampers.

[0071] The mappings 206a, 206b, 206c may comprise a look-up table or an algorithm. If an algorithm, the algorithm receives the operating damping parameter(s), and when executed, determines and outputs a damping force. Each mapping 206a, 206b, 206c is different to one another and is tailored or bespoke to the ride height that it is associated with.

[0072] The damping force determined through the mapping may occur once a threshold has passed. The threshold may be considered an operating damping parameter threshold and it may correspond to a damper length or damper velocity. In one example, the threshold comprises two thresholds, one for damper length and one for damper velocity, both of which are required to have been passed for a damping force to be determined in dependence on the ride height. Alternatively, the damping force in dependence on the ride height(s) may be continuously or repeatedly determined but it is zero Newtons (N) unless a threshold has been passed. In this case, the passing of the threshold triggers a damping force to be determined, which has a value other than zero N, in dependence on the ride height(s).

[0073] When the damping force is continuously or repeatedly determined, this may occur at least every 10ms, 5ms, 2ms or 1 ms. As described above, in some cases, a zero N damping force is determined which is indicative of that the stiffness of the damper does not need to be adjusted. In one example, a damping force other than zero N is determined which is indicative of that the stiffness of the damper needs to be adjusted to protect the damper.

[0074] The switching means 207 is configured to receive the ride height signal 210 and it is configured to determine a switch value based on the received ride height signal 210. The switch value is indicative of the required mapping associated with the received ride height signal. For example, the ride height signal 210 may comprise information representative of an “off-road mode”. The switch means 207 then determines a switch value based on the information, for example, 1 , 2 or 3, wherein each of 1 correspond to mapping 206a, 2 correspond to mapping 206b and 3 correspond to mapping 206c. The switching means 207 then sends a switching signal 220 comprising the switch value to the selection means 205. The selection means 205 then proceeds with selecting a mapping 206a, 206b, 206c and / or damping force signal 211 a, 211 b, 211 c, based on the switch value as described above.

[0075] In one example, the control system 200 does not comprise switching means 207. Instead, the selection means 205 receives the ride height signal directly, and based on the ride height signal 210 determines or selects a mapping 206a, 206b, 206c and / or damping force signal 211 a, 21 1 b, 211 c.

[0076] An example method performed by the control system 200 will now be described with reference to Figure 2.

[0077] The control system 200 receives the ride height signal 210 indicative of a selected drive mode or a value representative of the height of the suspension system relative to the ground. The ride height signal 210 is forwarded to the switching means 207 which determines a switch value based on the ride height signal 210. The switch means 207 then sends a switching signal 220 to the selection means 205. Based on the switch value, the selection means 205 selects one of the damping force signals 211a, 211 b, 211c outputted from a mapping that corresponds to the received ride height signal 210. The selection means 205 then outputs the damper signal 215 comprising the relevant damping force(s). In one example, the selection means 205 continuously or repeatedly outputs a damper signal 215, regardless if it comprises zero N damping force or a value other than zero N. In this example, a threshold relating to an operating damping parameter needs to have been passed in order for the damping force to have a value other than zero N. In an alternative example, a threshold relating to an operating damping parameter needs to have been passed in order for a damping force to be determined as described herein.

[0078] The damper length used as an operating damping parameter referred to in the present disclosure may be calculated by multiplying the wheel displacements (measured using height sensors) by a damper motion ratio. Damper motion ratio indicates how much leverage the wheel has over the damper and its associated spring. This can vary depending on the vehicle and can also vary front to rear. Furthermore, damper motion ratio depends on how and where the suspension is mounted in relationship to the wheel. As an example, for vehicles with independent suspension, if the damper and / or its associated spring is mounted close to the wheel, then there will be less leverage than if it is mounted further away from the wheel. For example, a 0.7:1 damper motion ratio means that for every 100mm the wheel moves, the spring and / or damper moves 70mm.

[0079] The damper velocity used as an operating damping parameter referred to in the present disclosure may be calculated using accelerations and displacement of the damper and applying a Kalman Filter to remove noise and improve phasing.

[0080] An example of a mapping of the present disclosure will now be described with reference to table 1 shown below. The top row (x-axis) represents damper displacement in meters ranging from -0.076 to 0.104, and the lefthand column (y-axis) represents velocity in meters per second ranging from -2 to 2. The damping force is shown in the table (z-axis) for specific damper displacements and velocities. For example, at a displacement of -0.054 m and at a velocity of -2 m / s, a damping force of 7000 N is applied.

[0081] Table 1 Figure 3 illustrates a vehicle 300 according to an embodiment of the present disclosure. The vehicle 300 shown in Figure 3 comprises a system 310 according to an embodiment of the present disclosure. The system 310 comprises a control system 100, 200 as described herein and illustrated in Figures 1 and 2 and further comprises at least one ride height sensor 312. The control system 100, 200 is configured to use the at least one ride height sensor 312 to obtain the at least one ride height signal 165. The system 310 shown in Figure 3 further comprises at least one damper sensor 314 configured to sense a damper length and damper velocity of the at least one damper, and send the sensed length and value to the one or more processors 120 as an operating damping parameter.

[0082] The vehicle 300 may comprise a control system 100, 200 as illustrated in Figures 1 and 2. The vehicle 300 in the present example is an automobile, such as a wheeled vehicle, but it will be understood that the control systems 100, 200 may be used in other types of suitable vehicles.

[0083] Figure 4 illustrates a method 400 according to an embodiment of the invention. The method 400 is a method of control systems 100, 200 and of a vehicle 300 as illustrated in Figure 3. In particular, the method 400 is a method of operating at least one damper of a suspension system of an automotive vehicle wherein the suspension system is operable at a plurality of ride heights. The method 400 may be performed by the control systems 100, 200 illustrated in Figures 1 and 2, respectively. In particular, the memory 130 may comprise computer-readable instructions which, when executed by the processor 120, perform the method 400 according to an embodiment of the invention.

[0084] The method 400 comprises receiving 401 a ride height signal 165, wherein the ride height signal is indicative of a selected suspension height of an automotive vehicle. The method further comprises determining 402 that an operating damping parameter has passed a threshold. In dependence on the determination that the operating damping parameter has passed the threshold, the method comprises determining 403 a damping force in dependence on the received ride height signal. Thereafter, the method comprises outputting 404, to the at least one damper, a damper signal 155 indicative of the determined damping force.

[0085] Figure 5 shows an example damper 500 in accordance with an embodiment of the invention. The damper 500 shown in Figure 5 is part of a suspension system 550, which can comprise other dampers 500 as shown in Figure 5, as well as other components of a suspension system. The damper 500 comprises a piston rod 510 and a piston 512 attached to the piston rod 510. The damper 500 also comprises a cylinder 520. The piston rod 510 of Figure 5 goes through both ends of the cylinder 520. In other examples, the piston rod 510 only goes through one end of the cylinder 520, and the piston rod 510 may end at the piston 512. The piston rod 510 shown in Figure 5 may have a mount at each end to mount on one end to the body of the vehicle and at the other end to the wheel associated with the damper. In other examples, for example where the piston rod 510 only goes through one end of the cylinder 520, the piston rod 510 may have a mounting to mount on one of the body of the vehicle and the wheel, and the cylinder 520 may have a mounting to mount on the other of the body of the vehicle and the wheel. The piston 512 is configured to travel within the volume of the cylinder 520. Hydraulic fluid, air or another fluid may be provided within the cylinder to provide resistance to the movement of the piston 512 within the cylinder 520. The piston 512 comprises a compression valve 530 and a rebound valve 540. The compression valve 530 and the rebound valve 540 are configured to be controlled to vary the amount of fluid allowed through from one side of the piston 512 to the other side, which varies the damping force and therefore the damping level provided by the damper 500. According to examples, the compression valve 530 controls compression damping of the damper according to the damping force indicated by the damper signal 155, 215. The rebound valve 540 controls rebound damping of the damper according to damping force indicated by the damper signal 155, 215. In some examples, the rebound valve 540 and the compression valve 530 are part of the same valve.

[0086] It will be appreciated that various changes and modifications can be made to the present invention without departing from the scope of the present application.

Claims

CLAIMS1 . A control system for controlling at least one damper of a suspension system of an automotive vehicle, the suspension system being operable at a plurality of ride heights, the control system comprising one or more processors collectively configured to: receive a ride height signal, the ride height signal being indicative of a selected suspension height of the automotive vehicle; determine that an operating damping parameter has passed a threshold; in dependence on the determination that the operating damping parameter has passed the threshold, determine a damping force in dependence on the received ride height signal; and output, to the at least one damper, a damper signal indicative of the determined damping force.

2. A control system according to claim 1 , wherein determining the damping force is further in dependence on the operating damping parameter .

3. A control system according to any preceding claim, wherein the operating damping parameter comprises at least one of: an operating damper length; and an operating damper velocity, of the at least one damper.

4. A control system according to any preceding claim , wherein: the determining of the damping force comprises selecting, in dependence on the ride height signal, a mapping between the operating damping parameter and the damping force and determining the damping force using the selected mapping.

5. A control system according to claim 4, wherein the determining of the damping force comprises selecting a mapping between the operating damping parameter and the damping force out of a plurality of mappings each of which is associated with different ride heights.

6. A control system according to claim 4 or 5, wherein the mapping comprises an algorithm configured to repeatedly receive the operating damper parameters and repeatedly determine the damping force.

7. A control system according to any preceding claim, wherein the one or more processors are configured to generate a switch value based on the received ride height signal, the switch value being indicative of the determined damping force the one or more processor is to select.

8. A control system according to claim 7, wherein the one or more processors are configured select a damping force based on the received switch value, and output the selected damping force to the at least one damper.

9. A system comprising the control system of any preceding claim and at least one ride height sensor, wherein the system is configured to use the at least one ride height sensor to obtain the at least one ride height signal.

10. A system according to claim 9, comprising at least one damper sensor configured to sense a damper length and damper velocity of the at least one damper, and send the sensed length and velocity to the one or more processors as an operating damping parameter.

11. An automotive vehicle comprising a control system according to any one of claims 1 to 8 or a system of claims 9 or 10.

12. A method for operating at least one damper of a suspension system of an automotive vehicle, the suspension system being operable at a plurality of ride heights, the method comprising: receiving at least one ride height signal, each of the at least one ride height signal being indicative of a wheel displacement of a corresponding wheel of the automotive vehicle compared to a body of the automotive vehicle; determining a damping force for each of the plurality of ride heights when an operating damping parameter exceeds a threshold, selecting a damping force based on the received ride height signal, and outputting the selected damping force to the at least one damper.

13. A method according to claim 12, wherein: the determining of the damping force comprises selecting, in dependence on the ride height signal, a mapping between the operating damping parameter and the damping force and determining the damping force using the selected mapping.

14. A method according to claim 13, wherein the determining of the damping force comprises selecting a mapping between the operating damping parameter and the damping force out of a plurality of mappings each of which is associated with different ride heights.

15. Computer readable instructions which, when executed by one or more processors, cause the one or more processors to perform the method according to any of claims 12-14.

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