Air suspension control

Abstract

Example embodiments relate to suspension systems and methods for vehicles. In some examples, a controller of a suspension system is configured to determine that the vehicle is in a service environment and set a height accuracy mode of the suspension system based on the determination that the vehicle is in the service environment. In some examples, the controller is configured to detect a suspension operating condition of the vehicle and change a setting associated with the suspension system based on the suspension operating condition. An example method includes detecting, using a controller, a suspension operating condition of a suspension system of a vehicle. The method can also include changing, using the controller, a setting associated with the suspension system based on the suspension operating condition.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. Provisional Patent Application Serial No. 63 / 226,679, filed July 28, 2021, and U.S. Provisional Patent Application Serial No. 63 / 240,689, filed September 3, 2021, the contents of which are expressly incorporated herein by reference in their entirety. Technical Field

[0003] This disclosure relates to a vehicle suspension system, and more specifically to a vehicle suspension system that allows adjustment of the vehicle's ride height. Background Technology

[0004] Some vehicle suspension systems allow manual or automatic adjustment of vehicle height. For example, users may be able to select different ride heights, such as to modify the vehicle's off-road capabilities. In another example, a vehicle may have an automatic leveling system that levels the vehicle in response to changes in vehicle load, such as placing a heavy load in the cargo area at the rear of the vehicle. Rough road surfaces may cause the vehicle to over-perform leveling events, causing the vehicle to attempt to respond to rapid changes in wheel position. Vehicle occupants may notice excessive activity and unnecessary actuation caused by the leveling system. Therefore, in some exemplary instances described herein, a road roughness metric or estimator dynamically estimates a roughness value that can be used to relax acceptable control tolerances of the air suspension system when the road surface is relatively rough. On these relatively rough surfaces, overcorrection by the leveling system can be reduced or completely prevented. Additionally, the tolerance can be changed in response to determining that the road surface is relatively smooth, thereby allowing the leveling system to make leveling adjustments as needed.

[0005] Another problem arises in vehicles with automatic leveling systems when the suspension or other components are incorrectly installed or repaired. For example, if an incorrectly installed or repaired vehicle component causes the vehicle to tilt (e.g., towards one side of the vehicle or at a corner), the vehicle's automatic leveling will inevitably increase the load exerted on the ground by the wheels at that side or corner, resulting in an asymmetric wheel load. Asymmetric angular loads negatively impact vehicle dynamics. Furthermore, the vehicle's level appearance can mask potential conditions for repair or assembly personnel. Therefore, in some exemplary instances, uneven angular loads can be addressed by employing control methods that level the vehicle suspension in a manner that facilitates the identification of incorrect vehicle suspension installation or setup, while responding appropriately under normal conditions or during operation. Summary of the Invention

[0006] In at least some exemplary instances, a suspension system for a vehicle includes a controller configured to determine that the vehicle is in a maintenance environment. The controller may also be configured to set a height accuracy mode for the suspension system based on this determination that the vehicle is in the maintenance environment.

[0007] In at least some exemplary suspension systems, the height accuracy mode includes at least a plurality of height accuracy modes with different corresponding control tolerances. Furthermore, the controller can also be configured to identify the optimal mode among the plurality of height accuracy modes based on the suspension system operating conditions and modify the suspension system to be in the determined height accuracy mode. Additionally, in these examples, setting the height accuracy mode to reduce the control tolerance may disable the vehicle's average axle control leveling.

[0008] In at least some examples, the controller is further configured to determine that the vehicle is outside a maintenance environment before setting a height axle control mode. Furthermore, this height axle control mode includes at least an average axle control method. Suspension height adjustment may be based on the average of two vehicle heights determined at a single axle of the vehicle.

[0009] In at least some exemplary suspension systems, the controller is further configured to determine when the vehicle is outside a maintenance environment before setting a height axle control mode. Additionally, the height axle control mode includes an independent axle control method, wherein a first height adjustment and a second height adjustment are performed independently at the first and second wheels of the vehicle's axle.

[0010] In a subset of these examples, the controller is configured to implement an independent axle control method in response to either the detection of a height error or the detection of incomplete height correction.

[0011] In at least some examples, a suspension system for a vehicle is provided, the suspension system including a controller configured to detect suspension operating conditions of the vehicle. The controller may also be configured to change settings associated with the suspension system based on the suspension operating conditions.

[0012] In at least some exemplary suspension systems, the suspension operating conditions include one of ground angle, vehicle steering angle, vehicle speed, suspension correction conditions, or ambient temperature.

[0013] In at least some examples, settings associated with the suspension system may include height change limit, vehicle speed limit, height change accuracy, independent level of axle height adjustment, height adjustment threshold, or one of the following during suspension activity.

[0014] In at least some exemplary suspension systems, the suspension operating conditions include vehicle ground clearance. Settings associated with the suspension system may include a vehicle speed limit. Additionally, the controller may be configured to implement a vehicle speed limit in response to the vehicle ground clearance exceeding a predetermined vehicle height threshold.

[0015] In at least some examples, the suspension operating conditions include vehicle speed, and the settings associated with the suspension system include a vehicle height limit. Additionally, the controller can be configured to implement the vehicle height limit in response to a vehicle speed exceeding a predetermined vehicle speed threshold.

[0016] In at least some examples, the suspension operating condition can be one of the following: single wheel joint movement exceeding a predetermined relative joint movement threshold, an automatic leveling event, a change in drive mode, or the vehicle's operating environment. In these examples, the setting can include axle height control methods.

[0017] In at least some examples, the axle height control method includes at least an average axle control method. Additionally, the suspension height adjustment may be based on the average of two vehicle heights determined at a single axle of the vehicle. In at least a subset of these examples, the axle height control method also includes an independent axle control method, wherein a first height adjustment and a second height adjustment are performed independently at a first wheel and a second wheel of the vehicle axle.

[0018] In at least some exemplary suspension systems, the controller is configured to implement an independent axle control method in response to one of the following: (a) detecting that the vehicle's operating environment is a maintenance environment, (b) detecting a height error, or (c) detecting incomplete height correction.

[0019] In at least some examples, the controller is configured to implement height changes at two different axles within an axle height difference limit, such that a first height change is initiated at the first of the two axles until the axle height difference limit is reached, and a second height change is initiated at the second of the two axles until either the height difference limit or the total height change is reached. In these examples, a second height change can be initiated until the height difference limit is reached, wherein the controller implements a third height change at the first of the two axles.

[0020] In at least some exemplary suspension systems, suspension operating conditions include the vehicle's ambient temperature. Additionally, the controller can be configured to reduce suspension activity in response to a detected first temperature exceeding a predetermined threshold.

[0021] In at least some examples, the controller can be configured to alter suspension activity across multiple discrete suspension activity categories. In these examples, each of these discrete suspension activity categories includes adjustments to one or more suspension operating parameters.

[0022] In at least some exemplary suspension systems, the controller is configured to equalize the air pressure of a plurality of air springs on a single axle after a height change is performed on that single axle, wherein the plurality of air springs are associated with the opposite wheel of the single axle.

[0023] In at least some examples, the controller is configured to change one or more heights of the vehicle by altering the air pressure of one or more air springs in the vehicle.

[0024] In at least some exemplary instances, a method is provided that includes using a controller to detect suspension operating conditions of a vehicle's suspension system. The method may also include using the controller to change settings associated with the suspension system based on the suspension operating conditions. Attached Figure Description

[0025] Figure 1 A schematic diagram of a vehicle with a suspension system is shown, which allows the vehicle body height to be adjusted via adjustable air springs according to an exemplary method;

[0026] Figure 2 The example is shown. Figure 1 A schematic diagram of a vehicle, showing exemplary pneumatic and electrical connections of the suspension system;

[0027] Figure 3 The example shown is for use with Figure 1 and Figure 2 The user interface for interacting with the suspension system;

[0028] Figure 4 The example shown is for use with Figure 1 and Figure 2 The user interface for interacting with the suspension system;

[0029] Figure 5 A process flowchart illustrating a method for facilitating modifications to a vehicle's suspension system, based on an example, is shown, including estimating the roughness of surfaces traversed by the vehicle.

[0030] Figure 6 A process flowchart illustrating a method for modifying a vehicle's suspension system according to an example is shown, including modifying the vehicle's height adjustment tolerance;

[0031] Figure 7 A flowchart illustrating the process of changing suspension settings according to an example is shown;

[0032] Figure 8 A correction strategy for suspension leveling correction of a vehicle, based on an exemplary method, is shown.

[0033] Figure 9 An exemplary correction strategy for suspension leveling correction of a vehicle is shown, based on an example.

[0034] Figure 10 A flowchart illustrating the process of adjusting the vehicle's suspension system ride height is provided.

[0035] Figure 11 A process flowchart is shown for a method of equalizing the air spring pressure in a vehicle's suspension system according to an exemplary example.

[0036] Figure 12 A control strategy for addressing overcorrection in a vehicle's air suspension system, based on an exemplary method, is shown.

[0037] Figures 13A, 13B and Figure 13C Each illustrates a strategy for reducing (e.g., in a vehicle) the activity of a suspension leveling system, according to a corresponding exemplary method;

[0038] Figure 14 A process flowchart illustrating a method for adjusting the vehicle's suspension system ride height according to an exemplary example is shown.

[0039] Figure 15 A schematic diagram of a vehicle with an over-restrained air suspension system is shown.

[0040] Figure 16A A schematic diagram of a vehicle with unequal load distribution on the front and rear wheels and corresponding air suspension pressures is shown.

[0041] Figure 16B Adjustments based on exemplary examples are shown. Figure 16A A flowchart illustrating the process of determining the vehicle's suspension system body height.

[0042] Figure 17A A graph showing the relationship between vehicle height selection and vehicle speed in "General" vehicle height control mode according to an exemplary method is shown.

[0043] Figure 17B A graph showing the relationship between vehicle height selection and vehicle speed in “energy-saving” vehicle height control mode according to an exemplary method is shown.

[0044] Figure 17C A graph showing the relationship between vehicle height selection and vehicle speed in "Sport" vehicle height control mode according to an exemplary method is shown.

[0045] Figure 17D A graph showing the relationship between vehicle height selection and vehicle speed in "Sport Start" vehicle height control mode according to an exemplary method is shown.

[0046] Figure 17E A graph showing the relationship between vehicle height selection and vehicle speed in "Off-road Auto / Rock Crawling" vehicle height control mode, according to an exemplary method, is shown.

[0047] Figure 17F A graph showing the relationship between vehicle height selection and vehicle speed in "Off-road Drift" vehicle height control mode, according to an exemplary method, is shown.

[0048] Figure 17G A graph showing the relationship between vehicle height selection and vehicle speed in "trailer towing" vehicle height control mode according to an exemplary method is shown.

[0049] Figure 18 A process flowchart illustrating a method for setting a vehicle speed limit in response to a suspension system height input, based on an exemplary example;

[0050] Figure 19 A process flowchart illustrating a method for adjusting vehicle suspension height to facilitate easy access to the vehicle, based on an exemplary example;

[0051] Figure 20 The combination shown is based on an exemplary example. Figure 19 The flowchart illustrates the process of adjusting the vehicle suspension height in an easy-to-access mode.

[0052] Figure 21 A process flowchart illustrating a method for adjusting vehicle suspension height to provide load leveling, according to an exemplary example, is shown; and

[0053] Figure 22 A process flowchart illustrating methods for facilitating modifications to a vehicle's suspension system is shown, including selecting and / or changing control parameters. Detailed Implementation

[0054] As will be further described below, in at least some exemplary methods, the roughness of roads, surfaces, tracks, etc., can be estimated based on the vertical displacement of the wheels away from the expected or neutral position over time or when a vehicle traverses a road, surface, track, etc. When traveling on a very smooth surface (e.g., a paved road), vehicle wheels may tend to experience minimal vertical movement. However, on rough surfaces (e.g., gravel roads, tracks, or any off-road environment), surface / road inputs will drive the wheels to move a larger vertical displacement away from their neutral position. It should be understood that the designation of “road” roughness or surface encompasses not only paved road surfaces but also unpaved roads, gravel, dirt, or any off-road environment.

[0055] An exemplary roughness metric can be determined using a function or algorithm that typically attempts to quantify road input experienced by the wheel over a distance as a representative of surface roughness. The quantified roughness can be used to influence suspension operation, for example, by setting or changing control tolerances in response to changes in roughness. Therefore, exemplary vehicles, suspension systems, and methods may involve determining a roughness metric of the surface traversed by the vehicle based on vehicle height measurements, and setting height adjustment parameters (e.g., tolerances) of the air suspension system based on this roughness metric. As will be discussed further below, in some exemplary methods, an estimate of surface “flatness” can be used in conjunction with an estimate of roughness to facilitate changes in suspension adjustment parameters adapted to surface conditions. For example, estimates of roughness and flatness can be used to desensitize the vehicle suspension system so that changes in vehicle height are less and / or less significant when the surface traversed by the vehicle is relatively rough or uneven. The vehicle and / or suspension system may have a controller or module configured to facilitate modifications to the suspension system based on the determined height adjustment parameters. For example, height adjustment can be facilitated by changing the tolerance associated with one or more heights or displacements of a control spring (e.g., an air spring in a vehicle). In some exemplary methods, the gain of the controller can be varied to adjust the tolerance, for example, by increasing the tolerance when a rough surface is detected and / or when the surface induces torsion in the vehicle suspension. As will be discussed further below, in situations where corrective actions may be difficult to implement or may lead to errors, such as when the vehicle wheels move rapidly over a relatively rough surface over time, or when an uneven surface induces a relatively large amount of suspension torsion, the vehicle may accordingly reduce or prohibit changes in vehicle height or methods of changing vehicle height.

[0056] In other exemplary approaches, the vehicle suspension system may employ different control methods to attempt to allow visual diagnosis of incorrect installation or repair of the vehicle. For example, as will be further described below, when the vehicle is in a repair or manufacturing setting, a relatively more precise control method may be used, employing independent height control at each corner / wheel / air spring of the vehicle. When the vehicle is not in such repair / assembly conditions, a relatively less precise control method may be used.

[0057] As discussed further below, in some exemplary methods, the vehicle, its controller, or the method may involve detecting the vehicle's suspension operating conditions or operating environment and modifying settings associated with the suspension system based on these conditions / environment. By way of example only, suspension operating conditions may include ground angle, vehicle steering angle, vehicle speed, suspension correction conditions, or ambient temperature, as will be discussed further below. Settings associated with the suspension system may include, for example, height change limits, vehicle speed limits, height change accuracy or tolerance, independent level of axle height adjustment, height adjustment threshold, or suspension activity.

[0058] Turn now Figure 1 and Figure 2 An exemplary vehicle 100 with a suspension system 101 is shown and described in further detail, which allows for control of the vehicle's body height, as can be used in conjunction with various exemplary instances herein. The vehicle 100 may be a battery-electric vehicle, for example, having one or more motor generators driven by electricity supplied by a battery pack (not shown). Figure 1 The diagram illustrates pneumatic and electrical connections between components of vehicle 100, discussed below, according to an exemplary method. Figure 2 In, it is shown that has Figure 1 The same pneumatic connections are shown for the vehicle 100 and suspension system 101, and more specific electrical connections, such as power connections, electrical signal connections, and electrical circuit connections, are also shown. The vehicle 100 includes a vehicle dynamics module 102, which is configured to control the vehicle's body height, for example, via one or more processors. The vehicle dynamics module 102 typically controls one or more air springs 104a, 104b, 104c, 104d (collectively referred to as 104). Typically, each air spring 104 can store aerodynamic energy in a chamber between the corresponding wheel of the vehicle 100 and the body of the vehicle 100 (not shown). Figure 1Each air spring 104 is positioned at a designated corner of the vehicle 100, serving, for example, as a compliant element in the suspension of the vehicle 100. In addition to the compliant nature of the air springs 104, shock absorbers or dampers (not shown) may be provided at each vehicle wheel to absorb the mechanical energy imparted to the wheel by bumps or undulations on surfaces traversed by the vehicle 100. Furthermore, the air springs 104 can be configured to raise or lower the vehicle height of the vehicle 100. More specifically, each air spring 104a, 104b, 104c, and 104d can raise or lower the corresponding corner height of the vehicle 100. As will be seen in further detail below, the vehicle dynamics module 102 can implement changes in vehicle height via the air springs 104, wherein each air spring raises its associated corner height within the vehicle 100. In some cases, the vehicle dynamics module 102 can automatically shift between different vehicle heights in response to vehicle conditions. In other cases, a user, such as the driver of the vehicle 100, can manually select different vehicle heights via a graphical user interface communicating with the vehicle dynamics module 102. Vehicle 100 may include one or more controllers, such as vehicle dynamics module 102. Vehicle dynamics module 102 and other controllers disclosed herein may include a processor and / or memory. Exemplary processors may be hardware processors, software processors (e.g., processors simulated using virtual machines), or any combination thereof. In some embodiments, the combination of processor and memory may be referred to as control circuitry of vehicle 100. In some embodiments, a single processor may be referred to as control circuitry of vehicle 100. Memory may include hardware elements for non-transitory storage of commands or instructions that, when executed by the processor, cause the processor to operate vehicle 100 according to the embodiments described above and below. For example, memory may include computer-readable or machine-readable media. Control circuitry may be communicatively connected to components of vehicle 100 via one or more wires or via a wireless connection.

[0059] The vehicle dynamics module 102 can be electrically communicated with the air compressor assembly 106, which generally controls the system air pressure. More specifically, an air storage volume can be housed within an air reservoir or canister 108. The air reservoir 108 can store pressurized air to maintain a reserve of aerodynamic energy that can assist the compressor 106 in raising the vehicle body height of the vehicle 100. A valve block assembly 110, actuated by the vehicle dynamics module 102, can be positioned between the compressor 106 and the air springs 104 and can be configured to facilitate airflow between components of the vehicle 100's suspension. For example, the valve block 110 can control the supply of air and / or aerodynamic energy from the air reservoir 108 to the air springs 104. The valve block assembly 110 can also facilitate the release of air pressure from the air springs 104. Each air spring 104 can be controlled independently, for example, via the valve block 110. For example, the valve block 110 can have a plurality of valves 111 corresponding to each air spring 104 and canister 108 (see...). Figure 2 The compressor 106 can be controlled by the vehicle dynamics module 102, for example via the compressor relay 114 and via temperature sensing and valve control input to the air compressor assembly 106. As will be described in further detail below, the angular height or displacement of the air spring 104 can be controlled based on any appropriate control parameters. In one exemplary method, displacement control can be used to implement control of the air spring 104, wherein air can be added to / removed from the air spring 104 based on a target displacement of the air spring 104 and / or the corresponding angular height of the vehicle 100. For example, in the case of a desired displacement of the air spring 104, the actual / measured displacement or corresponding angular height of the vehicle 100 is measured and compared with the target displacement / height, wherein air is added to / removed from the air spring 104 accordingly. In another exemplary method, air quality control can be used to control the air spring 104, wherein air can be added to / removed from the air spring 104 based on a target air quantity or mass. For example, in the case of a desired displacement of the air spring 104, the corresponding air mass corresponding to the desired displacement and / or turning angle height of the vehicle 100 is determined, wherein air is added to / removed from the air spring 104 to achieve the target air mass of the air spring 104. In yet another example, depending on the surface and / or vehicle 100 conditions, displacement control and air mass control may be selectively employed, as will be discussed further below.

[0060] Vehicle 100 may also include vehicle height sensors 112a, 112b, 112c, and 112d (collectively referred to as 112), each configured to measure the vertical displacement between the corresponding wheel and vehicle 100. The suspension system of vehicle 100 can typically automatically level vehicle 100 and change the vehicle height via adjustments to the air springs 104, for example, in response to one or more heights measured by the vehicle height sensors 112. Therefore, when vehicle 100 is carrying a relatively heavy load in the rear cargo area, the rear vehicle height sensors 112c and 112d can detect that the vehicle height has decreased. In response, vehicle 100 can increase the internal air pressure in the rear air springs 104c and 104d to level vehicle 100.

[0061] In exemplary instances herein, as will be described in further detail below, vehicle 100 may change height adjustment parameters (e.g., tolerance settings of the auto-leveling system or another suspension parameter, or change vehicle height) in response to, for example, vehicle 100 detecting that it is traversing a relatively rough surface. For example, vehicle dynamics module 102 or other controllers of vehicle 100 may be configured to increase the height adjustment tolerance in response to an increase in a roughness measure of the road surface. Alternatively, vehicle 100 may decrease the height adjustment tolerance in response to a detected decrease in a roughness measure of the road surface. In some exemplary methods, as will be described further below, the surface or roughness measure is based on a change in steering height error. As used herein, steering height error is defined as the difference between the expected vehicle height and the actual / measured vehicle height, which may be determined by sensor 112. Furthermore, in some examples, the roughness measure is a moving average of the steering height error over a given time window or period. While the examples herein generally involve changing the tolerance of the auto-leveling of vehicle 100's suspension system, any other appropriate suspension parameters may also be adjusted in response to a detected change in roughness. Therefore, the suspension parameters can be adjusted by the vehicle 100 and may be affected by changes in the roughness of the surfaces traversed by the vehicle 100, regardless of the degree. The vehicle 100 can adjust these parameters in response to a detected change in roughness. By way of example only, suspension damping settings, such as damper compliance / stiffness, can be adjusted in response to changes in roughness, for example, increasing compliance in response to an increase in roughness and / or decreasing compliance in response to a decrease in roughness.

[0062] Users can select various driving, suspension, or vehicle modes that can affect the performance of air suspension components. For example, ... Figure 3 and Figure 4 As shown, one or more user interfaces are typically available for selecting the drive mode. Figure 3User interface 300 and Figure 4 The user interface 400 can each provide a screen or menu to the driver or other vehicle occupants, for example, via a touchscreen. Figure 3 As shown, vehicle 100 is represented, where the vehicle height is 302 relative to the ground. Similarly, in Figure 4 The image shows vehicle 100, with its body height represented relative to another ground 402. User interfaces 300 and 400 can communicate with vehicle dynamics module 102 to modify vehicle 100 or components of its suspension. For example, various driving modes can affect the air suspension body height, such as by raising or lowering vehicle 100, or by changing the compliance of the air springs 104 or dampers / shock absorbers of vehicle 100. Figure 3 As shown, vehicle 100 includes a general mode, a sport mode, an off-road mode, a traction mode, and a power-saving mode, each of which is displayed in the user interface 300 for selection. After selecting one mode in the user interface 300, multiple sub-modes can be displayed. For example, after selecting the off-road mode in the user interface 300, as shown... Figure 4 As shown, the automatic sub-mode, rock crawling sub-mode, rally sub-mode, and drift sub-mode can be displayed in the user interface 400 for selection. One or more suspension or vehicle parameters can be displayed by combining the modes and sub-modes included in user interfaces 300 and 400. As an example only, different ride heights can be implemented in vehicle modes and sub-modes, as will be discussed further below. Furthermore, as will be further described below, multiple ride heights may be available within each mode and / or sub-mode, and the ride height can be customized for each of a given mode or sub-mode to achieve the desired performance characteristics of vehicle 100.

[0063] Turn now Figure 5An exemplary process 500 for determining a roughness metric is shown and described in further detail. Process 500 can typically be employed while the vehicle is moving; therefore, process 500 can, for example, use the vehicle dynamics module 102 to confirm or query that the vehicle 100 is moving, and then employ process 500 to determine the roughness metric. It should be noted that, alternatively, the previously determined roughness can be stored in the vehicle's non-volatile memory, which can be used as an initial value for the estimator if it has no opportunity to calculate it before the suspension is required to operate. This can be useful, for example, for situations where the vehicle is parked on a rough surface, allowing the roughness to be taken into account during subsequent use of the vehicle, thereby preventing the vehicle suspension from over-operating due to the rough surface. As input to process 500, the angular height error of one or more wheels of the vehicle 100 can be determined. In the exemplary process 500, the measurement is based on signals received from four sensors 112, each of which is positioned at a corresponding wheel of the vehicle 100. In other exemplary methods, other numbers of sensors and wheels are possible. Typically, the steering height error can be determined based on the difference between the expected or target height and the actual height (e.g., as measured by the vehicle height sensor 112). The appropriate expected or target height can be determined in any manner. By way of example only, the target could be the desired vehicle height of the vehicle 100 in off-road mode, for example, 11.5", or the target steering height of one or more air springs 104. The target height for a specific steering angle or position of the vehicle (e.g., where the air springs 104 are positioned) can change dynamically as the vehicle moves. Therefore, the target height can be adjusted to account for factors such as acceleration, deceleration, cornering, pitch, roll, etc. In this example, sensor 112 is a displacement sensor that measures the displacement of the wheels from the vehicle 100, although in other examples, wheel accelerometers, etc., could also be used.

[0064] At block 505 of process 500, vehicle dynamics module 102 can convert the steering height error into a Δ or change in the steering height error measurement result over a given time period. Initially, it should be understood that vehicle dynamics module 102 can typically always have a non-zero height error, resulting in DC offset. As described further below, DC offset typically refers to a physical offset error in the measurement result and can be generated by multiple sources (e.g., a bent sensor arm, an asymmetrically loaded vehicle, etc.). To prevent this DC offset from being considered a road / surface input, process 500 can remove the DC offset from the steering height error measurement result. Furthermore, at block 505, it may also be desirable to remove the effects of vehicle pitch or roll, or other generally constant inputs to the suspension not caused by roughness. For example, when vehicle 100 tilts towards the passenger side while traversing a left turn, there may be a steering height error due to vehicle tilt, but this effect is not caused by roughness. In contrast, when vehicle 100 traverses a rough surface, the steering height error at the wheels of vehicle 100 can change rapidly with wheel undulation. Therefore, process 500 can convert the input steering height error into a change in steering height error over time as Δ. In doing so, vehicle dynamics module 102 can typically remove additional static effects caused by non-road roughness effects. Thus, the result of block 505 can be a "steering surface input" at each air spring 104 and / or wheel.

[0065] Proceeding to box 510, process 500 can determine the road or surface input value, for example, by summing the absolute values ​​of the corner surface input determined at box 505. Therefore, process 500 does not know whether the surface / road input is positive or negative (i.e., whether a rough surface drives the wheels up or down), and simplifies the surface input by determining the absolute values ​​of the changes in the individual corner height errors and summing them together. Process 500 can then proceed to box 515.

[0066] At box 515, a velocity-dependent moving average filter can be applied to the input surface input values. Typically, instantaneous measurements of surface input values ​​can be very noisy signals. For example, a velocity-dependent moving average filter can be applied to obtain road surface roughness in an attempt to normalize road length measurements. For instance, the filter time constant can be scaled with vehicle speed to achieve different behavior at low and high speeds. For example, at relatively low speeds, a smaller time constant can be used because at low speeds, the roughness estimate is expected to emphasize the terrain that the vehicle has just traversed. In other words, it might be desirable to interpret a single event (such as curb impact or rock crawl) as a relatively rough surface and reduce the range of possible leveling events. This smaller time constant could be used for rock crawl or stopping on top of a curb in a congested parking lot, just as an example. In contrast, a relatively large time constant can be used at higher speeds because the roughness estimate is likely to have less noise but more closely reflects the general roughness of the road surface (as opposed to discrete low-speed events or inputs, such as rock crawl). A relatively large time constant can be used to reduce the effect of a single input at relatively high speeds, where the effect of a single input may be less significant when the surface is relatively smooth, and therefore leveling events may be more desirable at such higher speeds. Any filter device or filtering method can be used. In the example, a first-order low-pass infinite impulse response (IIR) filter can be used, resulting in an exponentially weighted moving average filter at the output. After block 515, process 500 can have the surface input values ​​within the previous time window.

[0067] Proceeding to box 520, process 500 can apply a speed-dependent gain determination to determine a final roughness estimate, for example, as a percentage. This determined gain can be speed-dependent, where the principle is similar to the filter time constant in box 515. Therefore, a relatively large gain can be used at lower speeds, while a smaller gain can be used at higher speeds. In this way, individual wheel displacements at lower speed events (e.g., driving over a curb) are considered very rough roads. In another example, at a vehicle speed of 20 km / h, a displacement of 40 mm on one wheel can be observed, which is considered a very rough road from the perspective of the vehicle height controller (i.e., vehicle dynamics module 102). In contrast, at higher speeds, a relatively small gain can be applied because it might be expected that the roughness metric captures larger wheel displacement events, but ignores smaller events common even on relatively smooth surfaces at high speeds. After determining the roughness metric, process 500 can terminate.

[0068] In some exemplary instances, vehicle 100 may be configured to select various modes in response to detected conditions. In some examples, vehicle 100 selects a height accuracy mode that facilitates changes to (a) the control tolerance associated with a change in vehicle height and / or (b) the height axle control mode associated with the method used to control the change in vehicle height. For example, the height accuracy mode may be changed to increase or decrease the accuracy of the change in vehicle height. A height accuracy mode may be selected from multiple height modes. Exemplary height modes may include height accuracy modes, such as a nominal accuracy mode and a maintenance accuracy mode, wherein the change in vehicle height is performed with a greater accuracy and / or a smaller control tolerance than the nominal accuracy mode. Alternatively or additionally, the height mode may include multiple height axle control modes that vehicle 100 may employ in response to detected conditions. In the examples herein, the height axle control mode may include an average axle control method, wherein the suspension height adjustment is based on the average of two vehicle heights determined at a single axle of the vehicle. Alternatively, in other cases, vehicle 100 may employ an independent axle control method, wherein a first height adjustment and a second height adjustment are performed independently at the first wheel and the second wheel of the vehicle's axle. Vehicle 100 may select an axle control mode in response to the detection of a maintenance / manufacturing environment or other detected conditions, as will be discussed further below.

[0069] When the vehicle is stationary, as described above and Figure 5 The values ​​of the exemplary roughness measurements shown typically do not change. If the vehicle stops and closes relatively quickly after entering the lane, the process of the vehicle crossing the curb to enter the lane and then stopping almost immediately may cause the vehicle to perceive itself as having parked on a “rough” surface upon restarting. To correct for this potential problem and facilitate appropriate changes to the suspension height adjustment parameters, it may be useful to consider the “flatness” of the surface the vehicle traverses.

[0070] As used herein, "flatness" refers to the absence of torsion between different axles of a vehicle (e.g., between the front and rear axles). Therefore, if the left / right displacements of the front and rear axles are the same—that is, the vehicle "tilts" by the same amount in the same direction at both axles (or when there is zero tilt at both axles)—the surface on which the vehicle is parked can be considered a perfectly "flat" surface. In contrast, a surface with undulations between the front and rear axles causes the front vehicle suspension to "tilt" to one side, and the rear vehicle suspension to induce "torsion" within the vehicle, and the surface is relatively less "flat" relative to the vehicle. Therefore, in some exemplary methods, the suspension system, the vehicle, or associated methods can determine the amount of torsion in the suspension system and determine height adjustment parameters based on the torsion. In at least some examples, torsion can be used in combination with other metrics (e.g., roughness) to determine height adjustment parameters. As further described below, exemplary instances of determining torsion may include determining the difference between a first lateral displacement difference of the front axle of the vehicle and a second lateral displacement difference of the rear axle of the vehicle.

[0071] If a vehicle is on a surface that causes suspension torsion between the front and rear axles / wheels, it can lead to difficulties in adjusting the vehicle's suspension height, especially when using the average axle control method mentioned above. More specifically, if height changes are controlled based on the average displacement of the two air springs 104 on opposite sides of a single axle, when the vehicle is tilted in opposite directions at the front / rear axles, one side of the vehicle will tend to exceed the vehicle height target, while the opposite side will tend to fall below it. Therefore, in some examples, an independent control method (i.e., independently controlling each of the four wheels / air springs) can be used in response to determining that the vehicle is on a relatively uneven surface or that the vehicle suspension is experiencing at least a threshold amount of torsion. Additionally, height changes may be limited when the vehicle is on a surface that causes a threshold amount of torsion in the vehicle suspension. It should be noted that flatness measurements are generally independent of the dynamic movement of the vehicle and / or suspension, and therefore, flatness measurements do not lose relevance when the vehicle is stationary. In contrast, roughness measurements may be less relevant when the vehicle is stationary, as they are determined based on the movement of the suspension / vehicle over time or as the vehicle traverses the surface. Therefore, flatness measurements can provide useful information for the vehicle's suspension system to determine whether / when to reduce height change corrections, especially at very low speeds or when the vehicle is stationary.

[0072] In the example, torsion can be defined as the absence of flatness, and torsion can be quantified by the difference between the lateral or interlateral displacements of the two axles of the vehicle. Torsion in the suspension can be based on (1) the difference between the first lateral displacement of the front axle of the vehicle and (2) the second lateral displacement of the rear axle of the vehicle. In one example, torsion is calculated as follows:

[0073] (FL displacement - FR displacement) - (RL displacement - RR displacement) = Torsion

[0074] in:

[0075] FL displacement = displacement of the left front air spring;

[0076] FR displacement = displacement of the right front air spring;

[0077] RL displacement = displacement of the left rear air spring; and

[0078] RR displacement = displacement of the left front air spring.

[0079] In other words, the displacement difference between the left front and right front air springs and the displacement difference between the left rear and right rear air springs can be compared to determine the torsion. When both the front and rear axles of the vehicle are tilted or rolling the same amount in the same direction (or both are horizontal), the torsion will typically be zero, and the underlying surface can be considered "flat." The above calculations provide a measure of the vehicle's torsion or diagonal load. In the example, a filtered signal can be used for each of the displacement measurement results.

[0080] As will be further described below, the aforementioned flatness or torsion measurements can be used in the context of vehicle 100 in at least several of the ways described herein. First, if the surface induces a certain amount of torsion in the vehicle (or in other words, if the surface is uneven to a certain degree), a height change request can be rejected. Additionally, vehicle 100 can use an independent axle control method (rather than average control) in response to a determined flatness metric. More specifically, if the surface is uneven, average axle control may result in asymmetry of the vehicle during operation, as described above. Furthermore, vehicle 100 can determine desensitizing factors to apply in response to a determined flatness metric to avoid or reduce the effects of vehicle height changes or leveling events.

[0081] In at least some exemplary instances, vehicle 100 can determine surface conditions based on surface flatness and roughness metrics, wherein height adjustment parameters are determined or adjusted according to one or both of these factors. As mentioned above, flatness or torsion can be determined based on static displacement measurements of air spring 104, and therefore flatness or torsion can provide useful information when vehicle 100 is stationary or at very low speeds. In contrast, roughness metrics, as described above, are determined based on the movement of air spring 104 and / or other components of vehicle 100 over time. Thus, in some exemplary methods, flatness and roughness are emphasized or de-emphasized based on the speed of vehicle 100. For example, when vehicle 100 is moving, roughness metrics may be relied upon more heavily (or any consideration of flatness / torsion may be excluded), while when vehicle 100 is stationary or at very low speeds (e.g., below 5 miles per hour (mph)), flatness / torsion may be relied upon more heavily (or any consideration of roughness may be excluded). Therefore, in some exemplary methods, the height adjustment parameters can initially be determined based on roughness, for example, when the vehicle is in motion, and then, for example, when the vehicle speed drops to zero or below a speed threshold, subsequent height adjustment parameters can be determined based on torsion. Furthermore, context switching can be used to determine desensitization factors used relative to the suspension height adjustment parameters. For example, if the height is known to be accurate when the vehicle 100's speed is above zero, desensitization can be applied when the vehicle is stopped / stationary (e.g., to reduce intervention for height change correction). On the other hand, if the known height measurement is less accurate when the vehicle 100 is moving (i.e., the vehicle speed is above zero), desensitization can be applied based on the (only) determined flatness / torsion.

[0082] Now for reference Figure 6 An exemplary process 600 for determining height adjustment parameters, such as to adjust the tolerance of the vehicle suspension of vehicle 100, is shown and described in further detail. Height adjustment parameters can be used to facilitate suspension modifications. Process 600 may begin at block 605, where surface conditions are determined. Surface conditions may include roughness (e.g., as illustrated above by roughness metrics) and / or flatness characteristics (e.g., as illustrated above by suspension torsion). For example, upon detecting that vehicle 100 is moving or engaging a controller, vehicle dynamics module 102 may, for example, determine a roughness metric of the surface traversed by vehicle 100 based on measurements of vehicle height and / or suspension torsion. In the example, block 605 employs process 500 to determine the roughness metric and the measurements of suspension torsion as illustrated above. Process 600 may then proceed to block 610.

[0083] At box 610, process 600 queries whether a change in surface conditions has occurred, for example, based on the roughness metric and / or suspension torsion determined at box 605. In some examples, the query at box 610 only yields a positive result if at least one of the roughness metric or torsion changes by at least a threshold amount or percentage. Therefore, it prevents vehicle 100 from altering suspension settings or ride height adjustment tolerances in response to small changes in terrain. If a positive result is obtained at box 610, process 600 can proceed to box 615, where height adjustment parameters, such as the height adjustment tolerance, can be modified based on the change in surface conditions. Thus, subsequent adjustments to ride height may be affected, for example, via adjustments to air spring 104. Alternatively, if a negative result is obtained at box 610, process 600 returns to box 605. Therefore, process 600 can typically monitor surface conditions continuously during the operation of vehicle 100.

[0084] For example, the exemplary roughness measure determined using processes 500 and / or 600 can be used to scale or adjust the height adjustment of vehicle 100, such as the height adjustment tolerance of the leveling feature of vehicle 100. Furthermore, tolerance adjustments can be performed based on performance expectations or anticipated performance of vehicle 100. As an example only, vehicle 100 can be adjusted more significantly in the sense that it is designed for off-road use or other non-road surfaces that are expected to be rough. Generally, the degree and / or frequency of height adjustments to the vehicle suspension can be reduced when the roughness measure is relatively large compared to a relatively smooth road or a smaller roughness measure. Furthermore, in the sense that a vehicle occupant or driver requests a change in the suspension, the roughness measure can be used to reduce the degree of requested adjustment of suspension components or to completely suspend adjustment. As an example only, when vehicle 100 determines that the roughness is below a predetermined threshold (i.e., indicating a relatively smooth surface), a relatively tight height adjustment tolerance of 2 mm can be used to control the vehicle body height, while when vehicle 100 determines that the surface it traverses is above the predetermined threshold (i.e., indicating a relatively rough surface), a relatively large height adjustment tolerance of 5 mm can be used.

[0085] Modifications to the suspension system 101 of vehicle 100 can be facilitated, for example, by changing tolerances, control parameters, or control methods, as further described in the exemplary processes or systems herein. By way of example only, modifications can be facilitated by sending instructions controlling various aspects of the suspension system 101 via one or more controllers, electronic control units (ECUs), etc., of vehicle 100. For example, vehicle dynamics module 102 can send software instructions to adjust the value or type of control targets, such as the air mass, displacement, pressure, or other mechanical aspects of air spring 104 and / or other components of suspension system 101. Modifications to the suspension system 101 of vehicle 100 can be performed in any suitable manner. In the example, modifications to the suspension system 101 of vehicle 100 can be performed by implementing height change parameters, for example, to change the tolerance associated with height change, such as by adjusting the gain of the controller. In another example, modifications to the suspension system 101 of the vehicle 100 can be made by changing the height axle control method or mode of the suspension system 101, for example, by switching from an average axle control method to an independent axle control method or vice versa. In yet another example, modifications to the suspension system 101 can be made by changing the control parameters used for height changes, for example, by changing from displacement control to air quality control or vice versa.

[0086] The exemplary roughness metrics identified herein can provide benefits beyond load leveling of a vehicle suspension system. For example, it may be beneficial to record or store roughness observed in a given vehicle over time. Furthermore, in the sense that a roughness metric demonstrates an anomalous event or condition of the vehicle, the metric can be broadcast from the vehicle to provide notification about vehicle conditions. Additionally, as mentioned above, other vehicle systems may also employ roughness metrics, such as an adaptive damping controller that can alter the damping characteristics of the vehicle suspension.

[0087] As described above, in some exemplary methods, vehicle 100 can be configured to facilitate the identification of incorrect vehicle or suspension installation or settings in certain environments. In an example, a controller such as vehicle dynamics module 102 is configured to determine that the vehicle is in a maintenance environment and set the suspension system's height accuracy mode based on this determination. The controller can also be configured to identify the optimal mode among multiple height accuracy modes based on suspension system operating conditions / environment (e.g., detecting that the vehicle is in a maintenance environment) and modify the suspension system to be in the determined height accuracy mode. In the examples herein, the maintenance environment can include maintenance locations, such as manufacturing facilities or vehicle assembly facilities, or vehicle dealerships or service stations. For example, the maintenance environment can be detected using notifications provided to vehicle 100 or its controller by maintenance personnel, such as by setting markers recognized by vehicle dynamics module 102 to indicate that vehicle 100 is in a maintenance environment. In another example, proximity of sensors associated with the maintenance environment can be automatically detected by the vehicle. In yet another example, the vehicle's GPS coordinates can be matched to known maintenance locations associated with the vehicle manufacturer. Therefore, in these examples, the maintenance environment can be automatically notified to vehicle 100. Since the examples in this paper generally involve identifying and correcting suspension system adjustments, in at least some of the examples, the maintenance environment can be identified in the sense that the environment is capable of performing suspension system adjustments, for example, environments with appropriate tools, trained personnel, etc., to correct problems or malfunctions in the suspension system or its components of vehicle 100.

[0088] It should be noted that immediate detection of the maintenance environment is not required for adjustments to the vehicle suspension. For example, adjustments can be made when the vehicle is undergoing maintenance rather than simply being parked in a parking lot (e.g., when a customer initially arrives). In one example, a maintenance worker can put the vehicle into maintenance mode, or the ECU or controller of vehicle 100 can detect that the vehicle is within a threshold proximity to maintenance equipment (e.g., a lift, maintenance computer, etc.) to adjust the vehicle's suspension system 101. In another example, vehicle 100 can detect proximity to a maintenance center, dealership, etc., and in response to said detection, make maintenance mode of vehicle 100 available to the driver or maintenance worker. In other examples, adjustments can be made regardless of whether vehicle 100 is undergoing maintenance. In this way, if vehicle 100 is placed in a maintenance environment, such as at a dealership, for some other reason, the vehicle can automatically initiate adjustments to make potential problems (e.g., faulty suspension components) more apparent to maintenance workers trained to notice and / or correct problems.

[0089] Now for reference Figure 7An exemplary process 700 for changing suspension settings is shown and described in further detail. At box 705, process 700 queries whether a height change is needed. If no height change is needed, process 700 can return to box 705 to monitor for any desired height change. If a height change is needed, process 700 proceeds to box 710.

[0090] At box 710, process 700 queries whether vehicle 100 is in an environment requiring high leveling accuracy, such as a maintenance or manufacturing environment. As described above, in one example, vehicle 100 may set a maintenance or manufacturing flag that is activated by manufacturing or maintenance personnel, detected by vehicle 100 as being in / near a maintenance environment, or otherwise persists for a period of time (e.g., 24 hours) in any manner described herein. If box 710 determines that the vehicle is in a maintenance / manufacturing environment, process 700 may then proceed to box 715.

[0091] At box 715, a high-precision mode of the air suspension leveling system can be achieved by relying on independent control of each air spring 104. In this way, leveling adjustments can typically be made with relatively high precision, thereby facilitating the identification of problems caused by incorrectly installed components. As an example, in the case of excessive torsion of the suspension bushings during installation or maintenance, the vehicle leveling event and the resulting relative increase in vehicle angular load at the associated air springs 104 and / or wheels may demonstrate the problem. By increasing the precision of the suspension control system in such an environment, vehicle 100 may more aggressively perform leveling adjustments, thereby exacerbating any resulting angular load differences caused by leveling and underlying suspension conditions. Alternatively, process 700 can disable average axle control leveling at box 715, allowing the height of each air spring 104 to be adjusted independently. In this way, angular load differences on both sides of the vehicle are more easily observed, in addition to those differences observed between the front and rear wheel angular loads. The increased accuracy of the high-precision mode and the use of independent control over each air spring 104 can help identify the source of potential problems, for example, by isolating specific wheel / air spring 104 for which the cornering load of the vehicle 100 is particularly heavy / light relative to other cornering loads.

[0092] In at least some of the examples in this paper, vehicle 100 includes multiple high-precision modes with different corresponding control tolerances. For example, in addition to the high-precision mode of the air suspension leveling system, a low-precision mode (as opposed to the high-precision mode) can be used for other situations / settings, as will be discussed further below.

[0093] If, at box 710, it is determined that the vehicle is not in a maintenance or manufacturing environment (or, for that matter, in other environments where high-precision leveling control is not necessary), process 700 may proceed to boxes 720-730, where a reduced precision control method is used for height changes. For example, a smaller precision control method (e.g., a 5 mm height adjustment tolerance instead of a 2 mm high-precision height adjustment tolerance) can prevent the vehicle 100 from over-leveling automatically.

[0094] At box 720, process 700 queries whether the desired height change determined at box 705 is the result of an automatic leveling event (i.e., vehicle 100 automatically corrects itself in response to the rear or side of the loaded vehicle) or a high-joint motion event. A high-joint motion event can be defined as the movement or joint movement of a single wheel, i.e., a single wheel joint movement exceeding a predetermined relative joint movement threshold. A relative high-joint motion event can indicate (i.e., in cases where suspension movement exceeds a predetermined minimum or a predetermined relative joint movement threshold) off-road operation or other extreme inputs to the vehicle suspension, as an example only. In either case, independent control of each air spring 104 and / or associated wheel may be desired. More specifically, the conditions that generate the need for an automatic leveling event cannot generally be assumed to apply equally to the driver and passenger sides of vehicle 100, for example, if the vehicle is already heavily loaded on the driver's side in the rear cargo area, and therefore it is desirable to ensure that both sides of vehicle 100 are level. Additionally, high-joint motion events can also guarantee independent control of the air springs 104 and / or wheels. If, at box 720, it is determined that either a leveling event or a high-joint motion event exists, process 700 may proceed to box 725. At box 725, vehicle 100 employs a normal-precision, independent control method, wherein the adjusted control tolerance is within normal parameters. In this example, the relatively lower precision of the normal-precision control method (e.g., within 5 mm of the target position, unlike the 2 mm target position for high-precision control) is configured to prevent overcorrection of vehicle 100 and / or the suspension system when correction may not be necessary. It should be noted that, in response to the reduction in control tolerance, average axle control may be disabled at box 725 (e.g., as described above, at box 715), causing vehicle 100 to employ independent control.

[0095] Alternatively, if process 700 determines at frame 720 that neither the leveling event nor the high joint movement event urgently requires a change in height, vehicle 100 can employ an average axle control method, and the process proceeds to frame 730. Thus, the vehicle height is adjusted based on the required average adjustment measured at each wheel on a given axle. For example, the average axle control method may be useful where a height change is initiated by a newly selected driving mode or a change in drive mode (e.g., selection of an off-road mode that increases vehicle ground clearance). In these cases, inter-lateral changes in vehicle 100 are unlikely to result in a height change. Therefore, the average axle method generally prevents inter-lateral adjustments of vehicle 100 when no adjustment is expected. Typically, equal angular loads can be more easily achieved using the aforementioned average axle control adjustment, which may yield optimal vehicle settings for dynamic behavior. Therefore, in the sense of prioritizing dynamic behavior, the average axle control method can improve the vehicle's ability to adjust to the correct height more quickly when the driver requests a change.

[0096] Turn now Figure 8 and Figure 9 The correction strategies used for leveling and correcting vehicle 100 are shown and described in further detail. Typically, vehicle 100 may attempt to address suspension correction conditions associated with suspension system 101. By way of example only, a change in the distribution of cargo, passengers, etc., in vehicle 100 may cause vehicle 100 to tilt between its sides or pitch towards the rear (“rear end”) or front (“nose end”) of vehicle 100. Suspension correction conditions may include such tilting or pitching of the vehicle, which vehicle 100 attempts to correct by adjusting the pressure of one or more air springs 104. Figure 8 In the method shown, individual steering angle control (i.e., where each air spring 104 is independently controlled to reach a target height) can cause diagonally symmetrical steering loads due to the over-constrained system of vehicle 100. In this example, the over-constrained system is a result of vehicle 100 having four wheels and associated air springs 104. Since three points define a plane, an adjustment to one of the four air springs 104 can affect the measured height and / or wheel load of one or more of the other air springs 104 and / or associated wheels. Figure 15The diagram provides an illustration of an over-constrained vehicle. In the example, different wheel loads and pressures at the four wheel positions can lead to a continuous process where the vehicle adjusts the height of one wheel, thereby changing the wheel load of another wheel and creating a need for height or pressure adjustment at that wheel. In the correction strategy depicted in Figure 8, leveling correction can be performed using individual steering angle control (i.e., an independent axle control method), which is applied in response to pitch correction, excessive, insufficient, or incomplete height correction, and steering angle height correction, while vehicle height changes can be performed using average axle control (i.e., where the correction amount determined for the two wheels of a single axle is averaged, and the correction amount is applied to the air spring 104 associated with each of the two wheels of that axle). However, using individual steering angle control in response to the indicated conditions can cause diagonally symmetrical steering angle loads. Improving control accuracy, for example, by reducing the tolerance for vehicle height error, may exacerbate the problem. In some cases, alignment capability is affected.

[0097] Therefore, in Figure 9 The middle provides a solution Figure 8 The illustrated example demonstrates the correction of problems experienced in the strategy shown. Typically, with Figure 8 Compared to the method shown, Figure 9The method shown employs individual steering control only for incomplete steering height correction (e.g., situations where average axle control cannot be used to address the issue during the initial attempt). More specifically, individual steering control is only permitted for subsequent attempts to correct the height. Therefore, average axle control is used to achieve vehicle height changes, pitch correction, over / under height correction, and initial or high-precision steering height correction. In other words, height correction can initially be performed using average axle control, followed by attempts using individual steering control (e.g., if the first attempt using average axle control is insufficient to effectively reduce the error). It should be noted that in some examples, a relatively high-precision control mode is not employed during normal vehicle operation (i.e., a relatively small tolerance for vehicle height errors). Additionally, average axle control can be used when vehicle 100 determines that the vehicle is on a flat surface or has a relatively low torsion level, although individual steering control can also be used. In this way, asymmetry caused by uneven surfaces can be reduced or eliminated. The same approach can be used for pitch correction: average axle control is used when the ground is flat or the torsion level is relatively low, while individual steering angle control is used when the ground is relatively uneven (or the torsion level is above a threshold). Individual steering angle control can also be applied instead of average axle control when correcting for relatively steep inclines or slopes (e.g., inclines or slopes above a predetermined value). Furthermore, in the illustrated example, roll correction can rely on individual steering angle control because if average axle control is used, the vehicle 100 tilting to one side could introduce asymmetry.

[0098] It should be noted that in some examples, because the air pressure on each axle is unequal, the axle height adjustment control is performed independently on the two axles of the vehicle. For example, as shown in Figure 16A, the internal pressure of the air springs 104 on different axles can differ, with a difference greater than the load distribution between the front and rear axles of the vehicle. More specifically, in the illustrated example, the vehicle is shown with a nearly balanced front / rear load distribution, i.e., the load on the front axle is slightly greater than 50%, and the load on the rear axle is slightly less than 50%. However, the air pressures on the front and rear axles are more significantly different. Therefore, it may be beneficial to control the height adjustment of the front and rear axles independently. More specifically, as... Figure 16BAs shown in the exemplary process 1600, the vehicle may initially be in standby mode at block 1605. In response to a height increase request for the vehicle 100, such as a request for automatic height increase by the vehicle or manual height increase by the vehicle driver, process 1600 may proceed to block 1610. At block 1610, the vehicle may initially raise the rear axle until the overall / desired height adjustment is achieved, or the permissible height difference between the axles is reached. If the permissible axle height difference limit is reached as the rear axle is raised, process 1600 may proceed to block 1615, where the axle has previously been raised to a height equal to that of the rear axle. Returning to block 1610, the rear axle can then be raised further. Therefore, process 1600 may iterate between blocks 1610 and 1615 as necessary to complete the height adjustment (i.e., if the permissible height difference between the axles is reached, process 1600 moves to block 1615, and if the front and rear heights are equal and the desired height is not achieved, it returns to block 1610). In this manner, the front and rear axles may be adjusted incrementally in an alternating manner until the height adjustment is complete, and process 1600 then returns to box 1605. Therefore, in some examples, the vehicle dynamics controller 102 can implement height changes at two different axles (i.e., front / rear axles) within an axle height difference limit. More specifically, a first height change is initiated at the first of the two axles (e.g., the rear axle) until the axle height difference limit is reached. Subsequently, a second height change can be initiated at the second of the two axles (e.g., the front axle) until either the height difference limit or the total height change is reached. If the second height change (e.g., a change to the front axle) is insufficient to achieve the desired height change, i.e., if a second height change is initiated until the height difference limit is reached, a third height change can be initiated, for example, at the rear axle. This exemplary alternating axle increment approach can minimize undesirable or extreme height differences between axles. In the example, the permissible height difference between the front and rear axles can be varied depending on vehicle conditions. For example, when the vehicle is in operation or driving, the vehicle may adopt a first permissible height difference (e.g., 20 mm), which is relatively smaller than another permissible height difference (e.g., 40 mm) used during other times when the adjustment is unlikely to be noticed by the vehicle's passengers.

[0099] Turn now Figure 10 and Figure 11 Problems can occur from time to time in air suspension systems, where, for example, the air pressure of the air spring 104 on a single axle may not be equal due to different circuit impedances. Figure 10 As shown, one illustrative method involves opening a valve, such as an air spring 104, to raise or lower the axle. After determining that the axle is within a specified tolerance range of the target height, the valve can be closed. In some cases, using... Figure 10 The methods outlined in the text can result in different internal pressures in the air spring 104 of the wheel axle. Now turn Figure 11 In the exemplary process 1100, Figure 10 One solution to the problem shown is to subsequently equalize the pressure of the air springs 104 at a given axle after a height change is implemented using air springs 104 associated with the opposite wheel (not shown) at the axle. More specifically, process 1100 can begin at box 1105, where one or more valves open to raise or lower the axle of vehicle 100. Proceeding to box 1110, the valves can be closed after detecting that the average axle height is within a target or specification. Proceeding to box 1115, with compressor 106 off and exhaust valve closed, the valves of the associated air springs 104 at each corner of the axle can be opened to allow pressure equalization in each air spring 104 of the axle. Process 1100 can then terminate.

[0100] Turn now Figure 12 An exemplary control strategy 1200 for addressing overcorrection of the air suspension system of vehicle 100 is shown and described in further detail. More specifically, in some cases, slight dynamic maneuvers of vehicle 100 can cause the air suspension system to perform potentially unnecessary leveling corrections to vehicle 100. In this example, a height control target of 5 mm is adopted, i.e., a change greater than 5 mm can cause a leveling response from vehicle dynamics module 102. Slight dynamic maneuvers can induce movement beyond the control target (e.g., 5 mm), which may cause undesirable intervention from vehicle dynamics module 102. Compensation based on vehicle acceleration (e.g., along the vehicle's longitudinal or lateral axles) has been attempted; however, "false alarms" can still occur, i.e., vehicle dynamics module 102 interprets slight dynamic maneuvers as leveling corrections. To further reduce the extent to which the leveling system may attempt to correct in these mild dynamic conditions, the applicable threshold for intervention can be scaled based on other factors as an alternative or additional scheme to scaling based on the acceleration of vehicle 100. Figure 12 In the example shown, the threshold used for leveling intervention can be scaled based on various suspension operating conditions, such as roughness or flatness / torsion.

[0101] exist Figure 12 In the exemplary control 1200 shown, at block 1205, suspension operating conditions may include the steering angle of vehicle 100, longitudinal acceleration of vehicle 100, lateral acceleration of vehicle 100, the slope and gradient of the surface traversed by vehicle 100. These factors can be used in conjunction with roughness and / or flatness / torsion combinations that can be applied at block 1210 to scale the threshold. Therefore, in Figure 12 In the example shown, each of these suspension operating conditions is used to change one or more settings associated with the suspension system. While in this example, the settings may include thresholds scaled according to roughness, flatness / torsion, lateral acceleration, longitudinal acceleration, steering angle, inclination, and slope, they may also depend on any other appropriate factors.

[0102] Typically, suspension operating conditions can be used to provide a calibration relationship between surface conditions (e.g., roughness and / or torsion) and to desensitize the height adjustment of vehicle 100 and / or suspension system 101. Additionally, desensitization can often be used to correct or prevent overcorrection of vehicle height or adjustments as described above. For example, if a single air spring in the air springs 104 goes out of range and is corrected, in a four-wheeled vehicle, this will inevitably cause a redistribution of vehicle load, which in turn will affect the other air springs 104. Therefore, adjusting one air spring 104 of suspension system 101 may create the need for adjustment of another air spring 104. Thus, vehicle 100 can detect the occurrence of these repeated adjustments and can desensitize subsequent adjustments (e.g., to increase the acceptable tolerance / range of height adjustment) to attempt to stop the vehicle or suspension from "seeking" subsequent adjustments more quickly.

[0103] exist Figure 12 In the exemplary control 1200 shown, at block 1215, the adjustment count made by vehicle 100 can be used to track height adjustments of vehicle 100. As the number of height adjustments increases within a given time period, control 1200 can increase the tolerance, thereby reducing the extent to which vehicle 100 attempts to make further height changes. Therefore, this adjustment count can be used to prevent potential "seeking" by vehicle 100, as described above. The adjustment count can be reset or reduced after indicating that vehicle 100 should determine whether a subsequent height adjustment should be made when conditions such as vehicle 100 stopping or otherwise changing occur. In this way, a threshold, such as a height adjustment threshold, can be scaled in response to vehicle 100 detecting that too many adjustments to vehicle height have been made within a given time period to scale the suspension system 101.

[0104] At box 1220, a context switch is used to emphasize or ignore dynamic desensitization. More specifically, if it is known that the height measurement is reliable when vehicle 100 is moving, it can be assumed that the height measurement is still reliable when vehicle 100 is stopped; therefore, all desensitization can be applied when vehicle 100 is stopped. On the other hand, if it is known that the height measurement is unreliable while moving, vehicle 100 may not be able to adjust. Therefore, in this example, vehicle 100 can complete its adjustment when it stops. For example, the vehicle stop indicator at box 1215 can desensitize the vehicle, and flatness is used as the sole scaling factor relative to a threshold.

[0105] The example of threshold scaling described above will now be discussed in further detail. In the following example, the height adjustment tolerance can be approximately 7.5 mm while the vehicle 100 is in motion (i.e., when the vehicle 100's speed is above zero), and the height adjustment tolerance can be relatively large when the vehicle 100 is stationary (e.g., 10 mm). Additionally, a larger tolerance can also be applied when the vehicle 100 has been braked (due to the close contact of the suspension components that may occur during braking).

[0106] In the first example of using roughness to scale the height adjustment threshold, the determined roughness amount can be used to scale the gain associated with the standard input tolerance (e.g., 10 mm when vehicle 100 is stopped). The gain can be applied such that it changes gradually to minimally increase the tolerance in response to relatively low roughness, and then rapidly increase the tolerance when higher roughness is detected. For example, as shown in Table 1 below, when the determined roughness is below 30%, zero gain is applied, making the standard tolerance range of 10 mm usable. Roughness increases to 30% with minimal increase, as reflected below, while roughness above 50% results in a large increase, which effectively reduces or eliminates the height adjustment of vehicle 100.

[0107] Table 1—Roughness

[0108] <![CDATA[ Roughness (%) ]]> <![CDATA[ Gain ]]> 0 0 30 0.1 (e.g., 11mm instead of 10mm) 40 2.0 (e.g., 30mm instead of 10mm) 50 10.0 (e.g., 120mm instead of 10mm)

[0109] It should be noted that, in comparison, the maximum movement of the air spring 104 in both the upward and downward directions of vehicle 100 can be approximately 120 mm to 150 mm. In one example, the maximum movement from the nominal position at standard height allows the air spring 104 to allow the wheel to bounce upward by 150 mm and rebound downward by 120 mm from the nominal position. Therefore, in the examples shown in Table 1 above, the adjustment at higher levels of roughness gradually comes to an almost complete halt.

[0110] The gain associated with the height adjustment threshold can be scaled in response to other factors. For example, the flatness or torsion shown in Table 2 below can be used to scale the height adjustment threshold. Similarly, the gain can be applied such that it changes gradually to minimally increase the tolerance in response to relatively level torsion or a relatively flat surface, and then rapidly increase the tolerance when higher torsion is detected. In the example shown in Table 2 below, zero gain is applied when torsion is determined to be below 20 mm, thus using the standard tolerance range. An increase in torsion to 30 mm results in a minimal increase in gain, as reflected below, while torsion above 100 mm results in a very large increase, which effectively reduces or eliminates 100% of the vehicle's height adjustment.

[0111] Table 2—Torsion / Flatness

[0112]

[0113]

[0114] As another example of scaling the height adjustment threshold in response to detected conditions, lateral acceleration can be used to reduce or eliminate intervention of vehicle 100 and / or suspension system 101 during relatively high lateral acceleration. Examples of scaling the height adjustment threshold are shown in Table 3 below. Similarly, a gain can be applied such that it changes gradually to increase the tolerance in response to relatively low levels of lateral acceleration, and then rapidly increase the tolerance when a higher amount of lateral acceleration is detected. In the example shown in Table 3 below, zero gain is applied when the lateral acceleration is determined to be below 0.5 m / s², thus using the standard tolerance range. An increase in torsion up to 30 mm results in a minimal increase in gain, as reflected below, while torsion above 100 mm results in a very large increase, which effectively reduces or eliminates the height adjustment of vehicle 100.

[0115] Table 3—Lateral Acceleration

[0116] <![CDATA[ Lateral acceleration (m / s²) 2 ) ]]> <![CDATA[ Gain ]]> 0.5 0 3.0 3.0 (e.g., 40mm instead of 10mm) 10 10.0 (e.g., 120mm instead of 10mm)

[0117] It should be noted that in some examples, when the lateral acceleration of vehicle 100 is above a relatively low threshold (e.g., below 3.0 m / s²), vehicle 100 may interrupt height adjustment to prevent the vehicle from "rolling" out of the turn due to lateral acceleration.

[0118] Now turn to Figure 13A. Figure 13C The document further illustrates and describes exemplary strategies for reducing the activity of a suspension leveling system (e.g., in vehicle 100). Typically, temperature (e.g., the ambient temperature of vehicle 100 or the operating temperature of components of vehicle 100) can be detected as a suspension operating condition, and a controller (e.g., vehicle dynamics module 102) can be configured to reduce suspension activity in response to detecting a temperature above a predetermined threshold. Furthermore, in the following examples, vehicle dynamics module 102 and / or other controllers of vehicle 100 can be configured to alter suspension activity across multiple discrete suspension activity categories, where each discrete suspension activity category includes adjustments to one or more suspension operating parameters.

[0119] In Figures 13A, 13B and Figure 13CEach of the three exemplary strategies shown illustrates that certain functions of vehicle 100, particularly the air suspension, can be reduced in response to an increase in the operating temperature of the compressor or other components (e.g., due to an increase in ambient temperature), and the suspension function level can be changed in response. One exemplary suspension function level includes a “full-function” level of maintenance (e.g., where the vehicle’s air compressor (e.g., compressor 106) is allowed to fill the tank or reservoir at any time the vehicle is not stopped (if the tank is depleted) to lift the vehicle, and speed-based vehicle lifting / lowering can be implemented). The suspension function level can be reduced from the full-function level to other, more reduced suspension function or activity levels in response to detected conditions. In some examples, a reduced suspension function level may typically be used to prioritize a height change requested by the driver, prior to automatic height changes or corrections as the hardware temperature rises. Such reduction of certain functions or activities can prevent damage to components of vehicle 100 (e.g., air compressor 106) due to operation at high temperatures, or conserve power in the vehicle 100’s battery pack. (See Figures 13A, 13B, and...) Figure 13C As shown in each of the accompanying figures, after vehicle 100 or suspension components reach various temperature thresholds, vehicle 100 may limit the functionality of vehicle 100 and / or the air suspension system, as described in the “Limited Functionality” box of other examples providing suspension functionality levels. Therefore, discrete suspension functionality levels may include at least the “Limited” box, and in some examples may include additional categories discussed further below. Upon reaching the aforementioned subsequent temperature thresholds, a first additional function of the air suspension system may be limited, for example, as in… Figure 13C As described in the "Limited Functionality 2" box, the function of the air suspension system can be completely stopped. In the "No Functionality" suspension function level, the vehicle 100 may be operable, but there is no ability to modify the vehicle height or other settings of the air springs 104 and / or the suspension system.

[0120] Turn now Figure 14 An exemplary process 1400 for a vehicle controller or system (e.g., the air suspension system or associated control system of vehicle 100) is illustrated. The exemplary vehicle may employ the determinations discussed above. Therefore, process 1400 may be embodied in vehicle dynamics module 102 or any other suitable controller of vehicle 100.

[0121] Process 1400 can begin at box 1405, where typically, the user altitude request, user drive mode request, and vehicle speed can be inputs to the altitude request arbitration. The target altitude can be output.

[0122] At box 1408, process 1400 can use measurements of torsion or flatness, such as those described above, to determine whether a height change should be rejected. More specifically, based on surface conditions determined at box 1420 as described below, process 1400 sets a marker to allow a height change if the torsion of vehicle 100 is below a threshold amount (e.g., at box 1425). In this way, if no marker is present at box 1425, the supervisory state machine 1430 can selectively reject a height change.

[0123] Proceeding to box 1410, the target height can be used to calculate the target turning height, as well as the slope and / or gradient. Therefore, the effect of the slope and / or gradient on a vehicle crossing the road can be considered for height changes, as demonstrated by vehicle lateral acceleration. Thus, the effect of the slope and / or gradient can be removed. The target turning height can be determined and output to the turning height error calculation. Procedure 1400 can then proceed to box 1415.

[0124] More specifically, at box 1415, the target corner height can be entered together with the measured / actual corner height to determine the corner height error. The corner height error can be used for roughness calculations, such as for roads or any other surface, and for calculating height corrections.

[0125] More specifically, proceeding to box 1420, you can input the vehicle speed along with the cornering height error to determine surface conditions, such as including roughness metrics, as shown above. Figure 5 And as described in exemplary process 500, and as described above, a measure of the flatness or torsion of vehicle 100. Roughness estimation may be input to the calculation of height correction at box 1425, and as described above, may be provided to box 1408 to determine whether subsequent height changes can be limited or prevented. If / when height correction is determined at box 1425, the supervisory state machine at box 1430 may output a lift / lower request based on the input correction and the requested lift / lower received from the height request arbitration. At box 1435, the lift / lower request is output to the hardware control state machine, which outputs hardware commands to implement the lift or lowering, for example, by adjusting the air pressure of a system as described herein. Process 1400 may then terminate.

[0126] In example Figure 14 In the system shown, vehicle height can be changed based on vehicle speed and / or the vehicle / suspension system's operating mode. Vehicle height adjustment can be based on vehicle mode and / or speed, for example, as in... Figures 17A to 17G and Figures 18 to 21Further illustrated and described below. Typically, various modes of vehicle 100 can be used to emphasize the vehicle's energy efficiency (especially in cases where the vehicle is an electric vehicle requiring energy conservation) or other desired performance / vehicle qualities. In some examples, vehicle drag can be rapidly reduced by lowering the height, thereby improving vehicle efficiency and range. In the illustrated example, the vehicle's body height can cause speed limits, for example, such that a relatively high or relatively low body height or ground height can result in a speed limit to prevent exceeding safe speeds when the vehicle has a relatively high center of gravity, just as an example. Furthermore, load leveling can be based on the corner height within a target window. Load leveling can use the exemplary roughness measure described herein and adjust the height to remain within the target window, where additional logic is added for measured height errors, and the fact that the vehicle is on different steep slopes and inclines is also taken into account.

[0127] Table 4 below shows several exemplary vehicle heights with corresponding ground clearance and offset distances (relative to the nominal or standard vehicle height settings). The settings listed in Table 4 include "High," "Standard," "Low," and "Minimum" settings. Typically, the user of vehicle 100 can implement the indicated ground clearance / setting in a given "mode" of the vehicle (e.g., Normal mode, Off-road mode, etc.) and then select one of these multiple vehicle heights. It should be understood that although five different vehicle heights are shown, any number of different settings can be used, and different ground clearances or offsets can be applied to these multiple vehicle heights.

[0128] Table 4—Vehicle Height Offset

[0129] <![CDATA[ Vehicle height ]]> <![CDATA[ Relative to standard offset (mm) ]]> Highest +90 high +40 standard Nominal (0) Low -35 lowest -50

[0130] The ground clearance indicated in Table 1 is measured relative to the height of the front subframe. This ground clearance may be the minimum ground clearance of the vehicle and may be relatively lower than the height of the rear subframe of the vehicle (e.g., to provide a desired vehicle posture where the rear of the vehicle is slightly higher than the front of the vehicle).

[0131] Now for reference Figures 17A to 17G The specific implementation of the vehicle body height in Table 1 is further described under different vehicle modes and according to the vehicle speed of vehicle 100. For example, different modes can be provided in vehicle 100, thereby facilitating the selection of different strategies for changing the body height based on speed. Generally, vehicle stability can be enhanced by speed limits imposed by vehicle 100 in response to body height. In addition, the speed limit imposed by vehicle 100 can be communicated to the driver after selecting a mode or height, giving the driver an opportunity to confirm or reconsider the height / mode request.

[0132] As described above, vehicle modes and sub-modes can be selected and implemented via a user interface or display, for example, as combined above. Figure 3 and Figure 4 As illustrated below, in the subsequent examples, vehicle 100 includes a general mode, a power-saving mode, a sport mode (with a "start" sub-mode), and an "off-road" mode (with sub-modes including "auto," "rock crawl," "drift," and "rally"). As will be further described below, the selection of a mode or sub-mode can result in the imposition of a vehicle height restriction, for example, preventing vehicle 100 from changing its body height above a predetermined height threshold. Various modes and sub-modes can also provide speed limits applicable to certain body heights, modes, or sub-modes; for example, selecting a relatively high body height or vehicle ground clearance above a predetermined vehicle height threshold may result in the imposition of a maximum speed limit on the vehicle and / or the communication of that maximum speed limit to the operator / driver.

[0133] Figure 17A The first example shown pertains to a "General" mode, where vehicle height selection is limited to high / standard / low vehicle heights, as illustrated in Table 1. General mode can typically be used for normal road applications or light off-road applications, and therefore can utilize settings such as vehicle height within the normal range and other vehicle restrictions.

[0134] like Figure 17A As shown, in general mode, vehicle 100 can automatically adjust its ride height in response to changes in vehicle speed, as indicated by arrows 1700, 1702, and 1704. More specifically, when vehicle 100 is in the "high" ride height setting, acceleration exceeding 75 km / h will cause vehicle 100 to immediately lower its ride height to the "standard" ride height, as indicated by arrow 1700. Further acceleration exceeding 82 km / h will cause vehicle 100 to lower its ride height to the "low" setting after maintaining a speed above 82 km / h for 45 seconds, as indicated by arrow 1702. Furthermore, after decelerating to 62 km / h, vehicle 100 will automatically raise its ride height back to the standard ride height, as indicated by arrow 1704. Height changes can also be prevented above 135 km / h, including automatic correction for leveling and height changes requested by the driver / occupant of vehicle 100. Typically, changes in ride height can be communicated to the driver, for example, via a display inside vehicle 100. Figures 17A to 17GThe various restrictions on vehicle height changes shown can be imposed by the vehicle dynamics module 102 and / or other modules or controllers associated with the vehicle 100. In the example, the vehicle dynamics module 102 imposes safety-related restrictions, such as limiting vehicle height selection to certain heights or modes, or preventing all height changes when the vehicle speed exceeds a threshold, while a separate controller or module of the vehicle 100 is responsible for imposing restrictions related to vehicle driving modes, such as limiting vehicle height changes to a manner consistent with the expected user experience in each mode.

[0135] Figure 17B The second exemplary mode shown relates to a "power-saving" mode, in which vehicle 100 typically seeks to conserve power, for example when the vehicle's traction battery has a relatively low state of charge. In power-saving mode, the vehicle height selection may be limited to standard and minimum vehicle heights, as shown in Table 1, for example. The power-saving mode can be appropriately used to reduce or minimize the power consumption of vehicle 100. In the power-saving mode of vehicle 100, the vehicle height selection is limited to between minimum and standard vehicle heights. Furthermore, vehicle 100 may perform automatic height adjustment in response to changes in vehicle speed, as indicated by arrows 1706 and 1708. More specifically, when vehicle 100 is in the standard vehicle height setting, if the vehicle accelerates above 50 km / h and remains above that speed for at least one (1) second, vehicle 100 will lower its vehicle height to the minimum vehicle height, as indicated by arrow 1706. As indicated by arrow 1708, after decelerating to 45 km / h and remaining below that speed for at least one (1) second, vehicle 100 will automatically raise its vehicle height back to the standard vehicle height. At speeds above relatively high levels, such as above 135 km / h, changes in altitude are also prevented. Figure 17B As shown. Energy-saving modes typically aim to reduce power consumption by minimizing wind resistance at higher speeds and reducing the number of lift / lower events by decreasing the number of vehicle height settings.

[0136] Figure 17C The third exemplary mode shown relates to a "sport" mode, in which the vehicle can be relatively lowered, suspension components are set to a relatively rigid configuration, etc. Therefore, in sport mode, the vehicle height selection can typically be limited to a lower vehicle height to reduce the vehicle's center of gravity height. For example, as... Figure 17C The sport mode shown restricts the vehicle 100's ride height to the low and minimum ride heights listed in Table 1. Furthermore, automatic ride height adjustment is disabled (i.e., it must be manually entered or requested by the vehicle driver to change between low and minimum ride heights), and ride height adjustment is completely locked above 135 km / h.

[0137] Turn now Figure 17D The exemplary fourth mode involves a "motion-initiated" mode / sub-mode. More specifically, it can be... Figure 3 The "Start" sub-mode can be initiated from the menu of the user interface shown in Figure 4. In Start sub-mode, vehicle settings such as the vehicle height can be set to the lowest / most rigid available settings to further lower the vehicle's center of gravity, which may be useful, for example, for accelerating from a standing stop to maximum acceleration. Figure 17D As shown, in Sport Start mode, vehicle 100 remains at the lowest vehicle height setting, and all other vehicle heights are unavailable.

[0138] Figure 17E The fifth exemplary mode shown relates to an "Auto Off-Road / Rock Crawling" mode, which may be appropriate when the vehicle 100 traverses wilderness or obstacles at a relatively low speed. For example, when the vehicle 100 is in "Off-Road" mode, either an "Auto" or "Rock Crawling" sub-mode can be selected, for example, as described above. Figure 3 and Figure 4 As described. Available vehicle heights are limited to high and maximum vehicle height. The automatic driving height setting is locked. When the vehicle is at its maximum vehicle height, the vehicle speed is limited to 40 km / h. At speeds above 20 km / h, additional requests from the driver to raise the vehicle height from high to maximum are locked. Furthermore, at speeds above 135 km / h, vehicle height adjustment is completely locked.

[0139] Figure 17F The sixth exemplary mode shown relates to the "Off-road Drift" and "Off-road Rally" modes / sub-modes of vehicle 100. For example, when the vehicle is in "Off-road" mode, the "Drift" and "Rally" sub-modes can be selected. In the Off-road Drift and Off-road Rally modes / sub-modes, the vehicle height selection can be limited to standard and high vehicle heights, as shown in Table 1, for example. Furthermore, automatic vehicle height adjustment is disabled, and vehicle height adjustment is completely locked above 135 km / h.

[0140] Figure 17G The seventh exemplary mode shown relates to the "trailer towing mode" of vehicle 100. When the vehicle is moving (i.e., above 0 km / h), all vehicle height adjustments are disabled, and manual vehicle height adjustment options are limited to standard and low vehicle height.

[0141] Now for reference Figure 18The process 1800 for setting a vehicle speed limit in response to a suspension system height input is shown and described in further detail. Process 1800 may begin at block 1805, where the vehicle speed limit is applied and communicated. For example, when the vehicle is raised to a relatively high or maximum vehicle height (e.g., body height) relative to the ground, it may be desirable to limit the speed of vehicle 100 so that higher speeds cannot be achieved. Figures 17A to 17G The exemplary vehicle modes shown herein implement the vehicle heights specified in Table 1, with the maximum vehicle height only available in Off-Road Auto / Rock Crawling modes. Furthermore, as described above... Figure 17E As stated above, after selecting the maximum vehicle height within the off-road automatic / rock crawl mode, the vehicle speed can be limited to 40 km / h. One or more vehicle heights can exceed a predetermined vehicle height threshold applicable to the speed limit, such that when vehicle 100 is at a height exceeding the limit, a speed limit can be applied and / or communicated to the operator / driver. Other maximum speeds, appropriate and applicable to other vehicle / ground heights, can be employed. As described above, in some examples, the speed limit imposed by vehicle 100 in response to the vehicle height selection can be communicated to the driver, giving the driver an opportunity to confirm or reconsider the height / mode request.

[0142] In box 1810 of process 1800, the speed limit on vehicle 100 can initially be maintained, for example, in response to confirmation that the vehicle height selection that caused the speed limit to be applied (e.g., the selection of the maximum vehicle height) has changed in response to the restriction communicated at box 1805 (e.g., the driver changes their mind). Initially, at box 1810, the speed limit is maintained until vehicle 100 confirms that the height reached is less than the height selection that caused the speed limit to be applied. Therefore, whenever the maximum vehicle height is requested, vehicle 100 can monitor the vehicle height selection and maintain the speed limit until it is confirmed that the vehicle has not reached the maximum vehicle height. In response to detecting that the vehicle has reached a vehicle height less than the maximum vehicle height (e.g., in response to driver input), vehicle 100 can remove the speed limit applied at box 1815.

[0143] Turn now Figure 19 and Figure 20 The document further illustrates and describes in detail an exemplary process for providing an "easy access" function in a vehicle (e.g., vehicle 100). Vehicle 100 may have an easy access feature or mode, which may be disabled by default in vehicle 100 but may be selected by the user / driver. Typically, the easy access function may facilitate the lowering of the vehicle to enhance the ease with which vehicle occupants can enter the vehicle. Figure 19An exemplary process 1900 is illustrated. Upon detecting that vehicle 100 has stopped, process 1900 proceeds to box 1905. Typically, at box 1905, process 1900 can change the vehicle height setting to the lowest available vehicle height. In the illustrated example, box 1905 includes a first box 1905a and a second box 1905b. At box 1905a, a target minimum height is set for vehicle 100. In the example, at box 1905a, vehicle 100 can begin to lower to the target minimum height, for example, the minimum vehicle height listed in Table 1. Proceeding to box 1905b, upon detecting that a vehicle door is open, process 1900 can raise the target height to the second highest vehicle height in real time. For example, if the vehicle is between the "minimum" and "low" vehicle heights when lowering, vehicle 100 can raise to the "low" vehicle height (instead of continuing to lower to the "low" height) upon determining that the door is open. Therefore, in the sense that vehicle 100 has not yet reached its minimum vehicle height setting when the door is opened, process 1900 generally avoids the door contacting an obstacle (which would have been possible if vehicle 100 had continued to lower while the door was open). Then, process 1900 can terminate. Now turning... Figure 20 Another exemplary process 2000 associated with the easy-access feature of vehicle 100 is shown and described in more detail. Typically, in process 2000, a previously selected target height may be implemented in response to determining that vehicle 100 is not stopped or otherwise ready to move. Thus, vehicle 100 can be raised from a lowered position to a desired vehicle height (e.g., the height to which vehicle 100 was previously moved) to facilitate exit from vehicle 100. In the illustrated example, at box 2005, the target is set to the previously selected height in response to vehicle 100 moving from a parked position. Vehicle 100 may continue to be raised until the target vehicle height is reached, or until further raising of vehicle 100 is no longer necessary (e.g., vehicle mode or selected vehicle height reduction, vehicle loss of power, etc.). Process 2000 may then terminate.

[0144] Now for reference Figure 21 The exemplary process 2100 for implementing load adjustment of vehicle 100 is further illustrated and described in detail. In the exemplary process 2100, roughness can typically affect changes in the vehicle height of vehicle 100. More specifically, in the illustrated example, an assessment of the surface the vehicle is traversing (e.g., road surface, ground, track, etc.) can be used to determine whether to implement a change in vehicle height.

[0145] Process 2100 may begin at box 2105, where a standby state may be used when vehicle 100 or its components monitor a target corner height of vehicle 100. For example, when moving along a given surface, process 2100 may monitor one or more corner heights of vehicle 100, for example, to determine whether the corner height is within an applicable range. When vehicle 100 detects that the corner height is not within the target window, process 2100 may proceed to box 2110.

[0146] In box 2110, process 2100 can evaluate the ground surface, such as a road, track, or other surface traversed by vehicle 100. For example, process 2100 can determine roughness, such as as described above. Figure 5 As described in [the document]. Box 2110 can classify the results as being above or below a threshold to determine whether the traversed surface is “smooth” or “rough.” If the roughness is determined to be “smooth” at box 2110, process 2100 can proceed to box 2115.

[0147] At box 2115, process 2100 can initiate an adjustment to the corner height that was initially determined to be outside the applicable target window.

[0148] Alternatively, if the roughness is determined to be rough at frame 2110, process 2100 can proceed to frame 2105 to wait. In this way, process 2100 can prevent vehicle 100 from attempting to traverse a relatively rough surface (or the vehicle on a non-horizontal surface, as mentioned above). Figure 5 Leveling is performed during the process described above.

[0149] It should be noted that process 2100 may proceed from box 2105 to box 2115 in response to the detection that the height target has changed, for example, when vehicle 100 has initiated an automatic change in vehicle height, or when the driver / user of vehicle 100 has manually requested a change in vehicle height. Therefore, process 2100 may proceed to adjusting the turning height of vehicle 100. After confirming that the vehicle's turning height is within its applicable target window, process 2100 may proceed to box 2105.

[0150] Turn now Figure 22 An exemplary process 2200 for implementing a change in the height of a vehicle (e.g., vehicle 100) is shown and described in further detail. Typically, process 2200 can facilitate a change in vehicle height based on different control parameters. Using different control parameters may be particularly advantageous in the context of a vehicle such as vehicle 100 with an air suspension system; however, they can also be used in the context of other suspension systems.

[0151] Typically, under nominal operating conditions, vehicle 100 and / or suspension system 101 can close a control loop around a target movement of the suspension (e.g., displacement of one or more air springs 104). However, at other times, controlling vehicle height changes based on target movement or displacement can be difficult. For example, if vehicle 100 is positioned on an uneven surface, rock, etc., such that one wheel is relatively unloaded or "suspended" off the ground, adding / subtracting air to / from the air spring 104 of the unloaded wheel may not cause a detectable displacement of the air spring 104. Therefore, vehicle 100 may not be able to determine whether the air spring 104 has been properly adjusted based on its displacement / position, and using displacement / position as a control parameter to control vehicle height changes may be difficult in such cases.

[0152] Given this limitation of displacement / movement-based control, exemplary process 2200 and / or vehicle 100 can control suspension adjustment based on different parameters when displacement control criteria are not met (e.g., displacement control is infeasible or may be ineffective). In other words, displacement control criteria can be defined to determine which displacement / position can be used as control parameters.

[0153] When process 2200 determines that displacement / position may be invalid under the displacement control criterion, vehicle 100 can control the addition / subtraction of air relative to air spring 104 based on control parameters different from displacement or position. For example, process 2200 can use air mass instead of displacement as the control parameter. In this example, vehicle 100 can determine the target air mass of one or more (and in some examples all) air springs 104 based on a height change request. Vehicle 100 can determine the target air mass based on measurements of the temperature of air spring 104, reservoirs, or other suspension components. Vehicle 100 can also determine the target air mass based on the measured displacement of air spring 104. Based on the known air mass in air spring 104, vehicle 100 can then add / subtract a certain amount of air to / from air spring 104 to achieve the target air mass of air spring 104. Because the air mass associated with the air spring 104 can be more easily measured or detected than displacement / position when, for example, the wheel of the air spring 104 is unloaded or substantially unloaded, an air mass-based control loop may implement changes in vehicle height more effectively than a displacement / position-based control loop. Therefore, even under conditions where adjustments to the air spring 104 may not cause a measurable movement of the air spring 104's displacement (e.g., due to the wheel's suspension being fully extended or relatively unloaded), appropriate adjustments can still be made to achieve changes in vehicle height.

[0154] Process 2200 can begin at box 2205, where a request to change the height of the vehicle suspension is received. Process 2200 can then proceed to box 2210.

[0155] At box 2210, a height control method for implementing the height change can be selected in response to a height change request. In some examples, multiple height controls can be used. One exemplary height control is displacement control, where air is added to or removed from one or more air springs of the vehicle suspension based on a target displacement of those air springs. Another exemplary height control is air mass control, where air is added to or removed from one or more air springs of the vehicle suspension based on a target air mass change.

[0156] As described above, air quality control may be advantageous under certain conditions, such as when displacement control may be ineffective. In the example, vehicle 100 and / or process 2200 may select different controls, such as displacement control or air quality control, based on conditions. More specifically, vehicle 100 may consider conditions that could indicate the possibility of displacement control effectively implementing a height change request. As described above, displacement control may be ineffective when one or more wheel / air springs 104 are relatively unloaded, for example, when the wheels are "suspended" from the vehicle due to uneven surfaces, rocks, etc.

[0157] Vehicle 100 and / or process 2200 may consider various factors that could indicate conditions where displacement control may be ineffective or otherwise challenging. In at least some examples, when selecting a control for implementing height changes, vehicle 100 may consider the displacement of one or more springs of vehicle 100. As will be further detailed below, displacement can be used to determine whether the springs of the suspension (e.g., air spring 104) are unlikely to be used as a control parameter to control vehicle height changes. The displacement of air spring 104 can be used to evaluate displacement control criteria, and control parameters / variables for implementing vehicle height changes can be selected based on these criteria. In subsequent examples, various displacement control criteria can be defined to evaluate conditions to determine whether displacement can be used as a control parameter for implementing vehicle height changes.

[0158] In one example, the displacement of a spring (e.g., air spring 104) can be evaluated to determine whether a displacement control criterion is met, thus enabling the use of displacement as a control parameter. Typically, when a wheel of vehicle 100 or an air spring 104 is relatively unloaded, the displacement of the relatively unloaded air spring 104 can be substantially different from that of at least one other air spring 104 in vehicle 100. For example, vehicle 100 may be positioned on an uneven surface such that three wheels (and associated air springs 104) support the load of vehicle 100, with a fourth wheel suspended in the air, causing air spring 104 to extend longer or even fully than the other air springs 104. In this case, the displacement of the air spring 104 of the suspended wheel will be substantially greater than the displacement of the other three air springs 104. Similarly, the displacement of a single air spring 104 can also indicate the relative displacement with respect to the other air springs 104 of the vehicle, which may indicate that displacement control may be infeasible and / or air quality control would be beneficial. For example, if one of the air springs 104 is at its maximum displacement (i.e., the wheel is fully extended from the vehicle), this can generally indicate that the other air springs 104 of the vehicle are not fully extended. In other words, in the sense that one wheel of the vehicle is fully or substantially fully extended, when the vehicle is stationary or at a relatively low speed, this can also indicate that the associated air spring 104 is relatively unloaded. Therefore, the other wheels / air springs 104 of the vehicle must bear a larger proportion of the vehicle load and are relatively less extended. Thus, in some examples, the displacement control criterion indicative of the selection of air quality control can be determined based on the displacement of a single wheel or air spring among the wheels or air springs 104. For example, the displacement of one or more air springs among the air springs 104 can be compared to a displacement threshold (e.g., based on a maximum or minimum displacement or other appropriate threshold) to determine whether the displacement control criterion is met.

[0159] Displacement control criteria that may be beneficial for air quality control can also be indicated by the vehicle's torsional level. As mentioned above, torsion can be defined as the difference between the relative displacement of one wheel of vehicle 100 and that of different axles. If the comparison of the displacement of air spring 104 indicates that the torsional level is above a torsional threshold, this also indicates that at least one wheel / air spring 104 is relatively unloaded, and therefore, air quality control for vehicle height changes may be beneficial.

[0160] In another example, displacement control criteria indicative of potential benefits for air quality control can be determined based on the load of one or more air springs in air spring 104. Air spring 104 may include load sensors that directly measure the load of air spring 104. Alternatively, vehicle dynamics module 102 or other controllers of vehicle 100 may be configured to determine the load based on the measured displacement of air spring 104 and any other measurements (e.g., vehicle load, pitch / roll, air quality, and / or temperature). In this example, if air spring 104 is below a load threshold (e.g., minimum load) or unloaded, this would also indicate that air spring 104 is fully or substantially fully extended, and that the other air springs 104 / wheels of vehicle 100 carry a relatively large share of the vehicle load (and therefore are relatively less extended).

[0161] In another example, multiple of the aforementioned factors (i.e., load, displacement, and torsion) together or in any appropriate subset are considered part of the displacement control criterion.

[0162] It should also be noted that, in the sense that displacement control is not feasible or may be ineffective, this can also indicate that an independent / individual control method relative to the air springs 104 of the vehicle can also be beneficial, at least compared to the average axle height method. As mentioned above, under some operating conditions of the vehicle 100, it may be desirable to control the height / change of the vehicle 100 based on the average of measurements between the two air springs 104 of the vehicle 100. However, as mentioned above, in cases where one wheel of an axle is relatively unloaded or relatively displaced compared to the other wheels of the same axle, an individual or independent axle height control method (i.e., where the control objective is implemented independently at each air spring 104 of a single axle of the vehicle 100) is necessary. Therefore, in at least some exemplary methods, the selection of air quality control at block 2210 also results in the selection of independent axle height control.

[0163] Process 2200 can then proceed to box 2215. At box 2215, adjustments to one or more springs of vehicle 100 can be initiated based on the control selected at box 2210. If displacement control is selected at box 2210, a target displacement or position of one or more air springs 104 of vehicle 100 can be set, and adjustments can be made to air springs 104 (e.g., by adding / subtracting air from air springs 104) to attempt to achieve the target displacement.

[0164] On the other hand, if air quality control has already been selected at box 2210, an air quality target can be set at box 2215. Vehicle 100 (e.g., vehicle dynamics module 102) can identify the target air quality based on measurements associated with suspension system 101. Vehicle dynamics module 102 can determine the target air quality change, i.e., the amount of air to be added to or subtracted from one or more air springs 104. Vehicle dynamics module 102 can also determine the action to implement the target air quality change based on one or more of the displacement of the air springs or the temperature of the air reservoirs or suspension components. Therefore, by way of example only, vehicle 100 can set the target air quality based on the temperature (e.g., in the sense that temperature affects the expansion / contraction of air within air springs 104) or position of suspension components (e.g., air springs 104).

[0165] After completing the adjustment at box 2215, process 2200 can proceed to box 2220. At box 2220, process 2200 can query whether the control target setting at box 2215 has been achieved. In the example, the determined control target (e.g., displacement target or air quality target) is compared with the actual measurement result. If process 2200 determines that the target has been achieved, or the actual measurement result is within a predetermined acceptable range, process 2200 can terminate. Alternatively, if the target has not been achieved, process 2200 can return to box 2210, where process 2200 can again determine the appropriate control parameters and proceed to adjust the components of the air suspension 101 of vehicle 100. In the sense that the first type of control parameter (e.g., displacement) was selected and determined to be invalid, process 2200 can select a different control parameter (e.g., air quality) in subsequent attempts.

[0166] The systems and processes discussed above are intended to be illustrative and not restrictive. Those skilled in the art will recognize that the actions of the processes discussed herein can be omitted, modified, combined, and / or rearranged, and any additional actions can be performed without departing from the scope of this disclosure. More generally, the above disclosure is intended to be exemplary and not restrictive. Therefore, the limits of the claimed invention should be determined by the claims and are not limited by this disclosure. Furthermore, it should be noted that the features and limitations described in any embodiment are applicable to any other embodiment herein, and flowcharts or examples associated with one embodiment can be combined with any other embodiment in a suitable manner, performed in a different order, or in parallel. Moreover, the systems and methods described herein can be performed in real time. It should also be noted that the above systems and / or methods can be applied to or used according to other systems and / or methods.

[0167] While some parts of this disclosure may refer to "convention" or examples, any such references are merely for providing context to this disclosure and do not constitute any admission that constitutes prior art.

[0168] The foregoing description includes exemplary embodiments according to this disclosure. These examples are provided for illustrative purposes only and not for limiting purposes. It should be understood that this disclosure may be implemented in different forms than those expressly described and shown herein, and various modifications, optimizations, and variations accorded to the following claims can be implemented by those skilled in the art.

Claims

1. A suspension system for a vehicle, the suspension system comprising: The controller is configured to: It is determined that the vehicle is in a maintenance environment; and Based on the determination that the vehicle is in the maintenance environment, the height accuracy mode of the suspension system is set, and Detect the suspension operating conditions of the vehicle; and Based on the changes in suspension operating conditions, the settings associated with the suspension system, The height accuracy mode is selected from multiple height modes with different corresponding control tolerances. The height accuracy mode includes a nominal accuracy mode and a maintenance accuracy mode. The maintenance accuracy mode changes the vehicle height with a greater accuracy and / or a smaller control tolerance than the nominal accuracy mode.

2. The suspension system of claim 1, wherein the controller is configured to identify the optimal mode among the plurality of height modes based on the determination that the vehicle is in the maintenance environment, and to modify the suspension system to be in the determined height accuracy mode; wherein the controller is further configured to disable the average axle control leveling of the vehicle based on the determination that the vehicle is in the maintenance environment.

3. The suspension system of claim 1, wherein the controller is further configured to determine that the vehicle is outside the maintenance environment to set a height axle control mode, wherein the height axle control mode includes at least an average axle control method, wherein the height adjustment of the suspension system is based on an average of two vehicle heights determined at a single axle of the vehicle.

4. The suspension system of claim 1, wherein the controller is further configured to determine that the vehicle is outside the maintenance environment to set a height axle control mode, wherein the height axle control mode further includes an independent axle control method, wherein a first height adjustment and a second height adjustment are performed independently at the first wheel and the second wheel of the axle of the vehicle.

5. The suspension system of claim 4, wherein the controller is configured to implement the independent axle control method in response to one of the following: An altitude error was detected; or Incomplete height correction was detected.

6. The suspension system according to claim 1, wherein the suspension operating conditions include one of ground angle, vehicle steering angle, vehicle speed, suspension correction conditions, or ambient temperature.

7. The suspension system of claim 1, wherein the settings associated with the suspension system include one of height change limit, vehicle speed limit associated with vehicle height, height change accuracy, independent level of axle height adjustment, height adjustment threshold, or suspension function level.

8. The suspension system of claim 1, wherein the suspension operating conditions include vehicle ground clearance, wherein the settings associated with the suspension system include a vehicle speed limit, and wherein the controller is configured to implement the vehicle speed limit in response to the vehicle ground clearance being higher than a predetermined vehicle height threshold.

9. The suspension system of claim 1, wherein the suspension operating conditions include vehicle speed, wherein the settings associated with the suspension system include a vehicle height limit, and wherein the controller is configured to implement the vehicle height limit in response to the vehicle speed exceeding a predetermined vehicle speed threshold.

10. The suspension system of claim 1, wherein the suspension operating condition is one of the following: single wheel joint movement above a predetermined relative joint movement threshold, an automatic leveling event, a change in drive mode, or the operating environment of the vehicle, and wherein the setting includes a wheel axle height control method.

11. The suspension system of claim 10, wherein the axle height control method comprises at least an average axle control method, wherein the height adjustment of the suspension system is based on the average of two vehicle heights determined at a single axle of the vehicle.

12. The suspension system of claim 11, wherein the axle height control method further comprises an independent axle control method, wherein a first height adjustment and a second height adjustment are performed independently at the first wheel and the second wheel of the axle of the vehicle.

13. The suspension system of claim 12, wherein the controller is configured to implement the independent axle control method in response to one of the following: The vehicle's operating environment is detected to be either a manufacturing environment or a maintenance environment; An altitude error was detected; or Incomplete height correction was detected.

14. The suspension system of claim 1, wherein the controller is configured to implement a height change at two different axles within an axle height difference limit, such that a first height change is initiated at a first axle of the two axles until the axle height difference limit is reached, and a second height change is initiated at a second axle of the two axles until one of the height difference limit or a total height change is reached, wherein the second height change is initiated until the height difference limit is reached, and wherein the controller implements a third height change at the first axle of the two axles.

15. The suspension system of claim 1, wherein the suspension operating conditions include the ambient temperature of the vehicle, wherein the controller is configured to reduce suspension activity in response to a detected first temperature exceeding a predetermined threshold.

16. The suspension system of claim 1, wherein the controller is configured to change suspension activity among a plurality of discrete suspension activity categories, each of the discrete suspension activity categories including one or more suspension operating parameter adjustments.

17. The suspension system of claim 1, wherein the controller is configured to equalize the air pressure of a plurality of air springs associated with the opposite wheel of the single axle after a height change is performed at the single axle.

18. The suspension system of claim 1, wherein the controller is configured to change one or more heights of the vehicle by altering the amount of air contained in one or more air springs of the vehicle.

19. A method for controlling a vehicle's suspension system, the method comprising: The controller is used to determine that the vehicle is in a maintenance environment; and The controller sets the height accuracy mode of the suspension system based on the determination that the vehicle is in the maintenance environment, and The controller is used to detect the suspension operating conditions of the vehicle's suspension system. and The controller is used to change the settings associated with the suspension system based on the suspension operating conditions. The height accuracy mode is selected from multiple height modes with different corresponding control tolerances. The height accuracy mode includes a nominal accuracy mode and a maintenance accuracy mode. The maintenance accuracy mode changes the vehicle height with a greater accuracy and / or a smaller control tolerance than the nominal accuracy mode.

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