Road disturbance compensation using road preview

Abstract

Road vehicles benefit from information about the upcoming road content by commanding actuation systems to compensate for or at least partially mitigate the expected effects of the road content. The present disclosure discloses methods and systems for utilizing advance information about road content to mitigate the effects of longitudinal and lateral disturbances induced by interactions with a road event.

Description

Attorney Docket No. L0710.70115WQ00ROAD DISTURBANCE COMPENSATION USING ROAD PREVIEWCROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority under 35 U.S.C. § 119(e) of U.S. provisional application serial number 63 / 741,181 filed January 2, 2025, the disclosure of which is incorporated by reference in its entirety.FIELD

[0002] Controlling of road vehicles that have access to road preview.BACKGROUND

[0003] A vehicle typically experiences disturbances induced by the road surface as it travels along a road. Such inputs may impact occupants’ comfort, perception, productivity, safety, and / or the operator’ s ability to effectively operate the vehicle.

[0004] Attempts have been made to implement control strategies the negative impact of road surface disturbances buy using and various actuation methods and systems including steering, braking, and suspension actuators.SUMMARY

[0005] According to aspects of the disclosure, there is provided a method, of operating a vehicle with a multiplicity of wheels, which includes traveling, with the vehicle, along a road surface that includes a road event; interacting with the road event with a first wheel of the multiplicity of wheels; inducing a reaction force on the vehicle in the direction of travel by the road surface, e.g. in the longitudinal direction, as a result of the interaction; generating a command, with an algorithm operating in a microprocessor-based controller, for the vehicle’s propulsion system to change a torque being applied to at least one wheel of the vehicle; implementing the command; and mitigating one or more effects induced by the reaction force. In some embodiments, the torque is applied to the first wheel or to at least a second wheel. In some embodiments, the force may be a retarding force, and the torque applied to the at least one wheel mitigates the effect of the retarding force, or the force may -1- #14746727vlAttorney Docket No. L0710.70115WQ00be a driving force and the torque applied to the at least one wheel mitigates the effect of the driving force. In some embodiments the road event is a bump or a pothole. In some embodiments, the method includes receiving information about the location of the road event relative to the first wheel and the timing of the implementation of the command at least partially based on the information. The information may be at least partially based on data received from on-board non-contact sensor systems such as LiDAR, radar, laser, time-of-flight sensor, a single camera, or stereo camera. Alternatively or additionally, the information may be based at least partially on previously collected road surface data received from a local database in the vehicle or in the cloud.

[0006] According to aspects of the disclosure, there is provided a method, of operating a vehicle with a multiplicity of wheels, which includes traveling along a road surface that includes a road event; interacting with the road event with a first wheel of the multiplicity of wheels of the vehicle; as a result of the interaction, changing a position of the first wheel relative to the vehicle body; as a result of the change of position, applying a steering torque to the first wheel; with an algorithm operating in a microprocessor-based controller, generating a steering command to counteract the steering torque; implementing the steering command with a steering actuator; and mitigating the effects of the steering torque. In some embodiments the road event is a bump or a pothole. In some embodiments the method also includes receiving information about the location of the road event relative to the first wheel and timing the implementation of the command at least partially based on the information. The information may at least partially be based on data received from an onboard non-contact sensor system such as LiDAR, radar, laser, time-of-flight sensor, a single camera, or stereo camera. Alternatively or additionally, the information may be based at least partially on previously collected road surface data received from a database in the vehicle. In some embodiments the first wheel may be a front steering wheel or a rear steering wheel.

[0007] According to aspects of the disclosure, a method is provided for operating a vehicle with two front wheels and two rear wheels, which involves traveling along a road surface that includes a road event; interacting with the road event with a front wheel of the vehicle at a first time; interacting with the road event with a rear wheel of the vehicle, wherein the rear wheel is a steering wheel; as a result of the interaction with the rear wheel,-2- #14746727vlAttorney Docket No. L0710.70115WO00changing a position of the rear wheel relative to the vehicle body; as a result of the change of position, applying a steering torque to the rear wheel; with an algorithm operating in a microprocessor-based controller, generating a steering command to counteract the steering torque; implementing the steering command with a steering actuator associated with the rear wheel; and mitigating an effect of the steering torque on the rear wheel. In some embodiments, the method may also include timing the implementation of the command at least partially based on the first time, a distance between the first wheel and the second wheel, and a speed of the vehicle.

[0008] It should be appreciated that the foregoing concepts, and additional concepts discussed below, may be arranged in any suitable combination, as the present disclosure is not limited in this respect. Further, other advantages and novel features of the present disclosure will become apparent from the following detailed description of various nonlimiting embodiments when considered in conjunction with the accompanying figures.BRIEF DESCRIPTION OF DRAWINGS

[0009] The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures may be represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing. In the drawings:

[0010] Fig. 1 illustrates a wheel of a vehicle encountering a bump which may be referred to as a type of road event;

[0011] Fig. 2a illustrates a wheel of a vehicle traversing a road event;

[0012] Fig. 2b shows the vector diagram of forces during the event in Fig. 2a;

[0013] Fig. 3 illustrates a wheel of a vehicle with a suspension component while traversing a road event;

[0014] Fig. 4 illustrates a model of a suspension linkage creating a kinematic relationship between vehicle body motion and wheel motion;

[0015] Fig. 5 shows kinematic wheel recession curves for an example vehicle;-3- #14746727vlAttorney Docket No. L0710.70115WO00

[0016] Fig. 6 shows a block diagram of a method for compensating for the effect of a road event; and

[0017] Fig. 7 shows plots of sample responses of a vehicle interacting with a road event with and without mitigation of the longitudinal effects on the vehicle.DETAILED DESCRIPTION

[0018] When a vehicle travels along a road, the contour, uniformity, regularity, shape, and other properties of the road determine the effect of the road on the vehicle. The vehicle’s occupants and / or operators generally seek to achieve a high level of comfort and safety, and the disturbances induced by interactions between the road surface and the vehicle may have a substantial negative impact on both safety and comfort. Hence, minimizing the adverse effects of road-induced disturbances is generally a goal of vehicle design. As used herein, the term “occupant” refers to a person or animal in the vehicle. As used herein, the term “operator” refers to a person or a microprocessor-based controller that operates the vehicle and controls parameters such as path, speed, or behavior generally in order to guide the vehicle from a starting point to an end point of a trip.

[0019] The effects of the road may be felt in multiple ways and through multiple transmission paths. As the vehicle interacts with the road surface, its suspension may articulate, causing or allowing the wheels to move relative to the vehicle body. This movement can induce lateral, longitudinal, or vertical force inputs that may be felt by the vehicle occupants. The tires may also be affected as they traverse different types of road surfaces, generating sounds that may be objectionable to occupants. Additionally, the vehicle's motion may impair the operator's ability to control the vehicle, especially if the motion does not match expected patterns or exceeds acceptable thresholds for the operator. In order to change the effect of road inputs on the vehicle, a vehicle designer may seek to optimize the vehicle response. Alternatively or additionally, actuators may be used to modify the vehicle’s response to specific road input.

[0020] Various actuators in a vehicle may be used to modify the relative displacement or the relative force between two components in a vehicle. Actuators may include suspension actuators such as active or semi-active dampers, active roll elements, or active springs; they -4- #14746727vlAttorney Docket No. L0710.70115WQ00may include traction elements such as drive motors, brakes, or transmission elements such as differentials or gear boxes; they may include steering actuators such as front or rear steering actuators or power steering elements; and they may include actuators in various other parts of the vehicle such as seat actuators.

[0021] Controlling the motion of an actuator generally requires a control strategy and a computing element to apply this strategy. Computing elements may be micro-processors or processors of any kind, while a control strategy can generally be divided into categories such as adaptive control strategies, feedback control strategies, and preview control strategies, or a combination thereof.

[0022] Preview control strategies utilize advanced knowledge of the upcoming road to create a control strategy for an actuator that modifies the expected response of the vehicle to a particular road input. Preview control generally has several advantages over pure feedback or adaptive control. One advantage of preview control is the ability to compensate for slower than desired actuation elements by applying a command early enough to achieve the desired effect. For example, advanced knowledge of an upcoming bump may allow an algorithm running on a microprocessor controller to effectively respond with an air spring. Such an actuator, which generally operates slowly, can then adjust the desired ride height by the time the bump is encountered. Another benefit of preview controller is the manner in which a controller can respond to nonlinear limits of a system, the environment, or the actuators. Such limits may for example include limited actuator force or actuator stroke. With sufficient preview, a controller may be able to predict when such limits may be reached and act accordingly to identify an optimal response, for example minimizing the effects of such limits.

[0023] Preview control typically relies on accessing information about the upcoming road ahead of the vehicle or a particular wheel. There are multiple methods or systems that may be used to implement such control strategies on vehicle systems, including using vehicle-based non-contact sensors such as radar, LiDAR, or vision sensors like single or stereo cameras. Additionally, cloud-based or vehicle-based preview methods may use stored road information and implement terrain-based localization and navigation techniques to access precise information about the upcoming road surface. Localization may be aided by -5- #14746727vlAttorney Docket No. L0710.70115WO00using global navigation satellites, relative localization using sensors, and / or terrain-based localization. Alternatively or additionally, road preview may be accomplished for a trailing wheel (e.g. rear wheel), by monitoring (with e.g. accelerometers, wheel displacement sensors) the interaction between a leading wheel (e.g. front wheel) and road surface events or anomalies (e.g. bumps, potholes, cracks, expansion joints, manhole covers, storm drain covers).

[0024] Turning to the figures, specific non-limiting embodiments are described in further detail. It should be understood that the various systems, components, features, and methods described relative to these embodiments may be used either individually and / or in any desired combination as the disclosure is not limited to only the specific embodiments described herein.

[0025] Fig. 1 illustrates the wheel of a vehicle encountering a bump, also referred to as a type of road event. As used herein, the term "road event" refers to any road surface characteristic or feature that perceptibly influences the behavior of a vehicle traversing it. This includes, for example, the road profile along the path of the vehicle on both the left and right sides, the road camber and slope at points that are currently or will in the future be in contact with a tire of the vehicle, the road roughness and friction, and any other road characteristics that can measurably affect the motion of the vehicle body or one or more wheels as the vehicle traverses a section of road. In Fig. 1, the road event is represented as discrete bump, but road events may also include continuous changes in road characteristics as well as discrete ones as the disclosure is not so limited. A discrete road event may be characterized as a whole, such as defining a speed bump a whole. Alternatively, a road event may be part of a continuous road characteristic that includes, for example, each section of a bump as well as the road both ahead of and behind the bump.

[0026] Even though only a single wheel of a vehicle is shown in Fig. 1 and the subsequent figures, they represent the behavior of the entire vehicle. Similar simplified models, frequently called “quarter-car” models, are used in the art to illustrate the behavior of multi-wheeled vehicles. For example, in such models, a four-wheeled vehicle is conceptually divided into four corners, where the motion of each comer is representative of the behavior of-6- #14746727vlAttorney Docket No. L0710.70115WQ00the other corners of the vehicle. However, this disclosure applies to vehicles supported by any number of wheels, as the disclosure is not so limited.

[0027] Fig. 1 illustrates an idealized vehicle interaction with road 104. Vehicle body 101 is connected to wheel 103 through a suspension element 102. Wheel is in contact with a road 104 that exhibits a certain road profile including a schematically drawn bump 104a ahead of the vehicle. Vehicle 101 in this drawing is assumed to be travelling from left to right. The weight of the vehicle exerts a force indicated by arrow 105 on the tire that pushes toward the ground, and the equal and opposite reaction force from the ground is indicated by arrow 106.

[0028] Fig. 2a shows the vehicle illustrated in Fig. 1 as the wheel starts to climb bump 104a. The ground 104 under wheel 103 has a significant slope in the direction of travel. Fig. 2a illustrates the dynamics of contact between the tire and the ground. The vehicle's weight, represented by arrow 105, aligns with the gravitational field, pointing approximately toward the center of the earth. The ground's reaction force 204 at the tire-ground contact point is normal to the ground at that point. In real- world scenarios, the total force vector at the tire-ground contact patch can vary based on the tire-ground system's state. However, in typical driving situations on most roads, it is approximately normal to the ground as illustrated in the idealized illustration in Fig. 2a.

[0029] Fig. 2b shows a vector diagram illustrating that the force of gravity acting on the vehicle, represented by arrow 105, is counteracted by a force applied by the ground, represented by arrow 204. This ground force is not aligned with arrow 105 and thus has a reaction component aligned with the direction of travel, represented by arrow 205. It is noted that the vector sum of all the forces applied by a wheel on the ground (i.e. the total force F applied by the wheel) is opposed by the total reaction force R by the ground on the wheel which is equal and opposite to F. The total reaction force R 204 applied by the ground can be decomposed into two components: one that is equal and opposite to the force of gravity 105 supported by the vehicle wheel, and another component force 205 that is parallel and opposed to the direction of travel, as well as perpendicular to the force of gravity. Therefore, depending on its shape, a road surface that is not parallel to the direction of travel may: apply a longitudinal force on the vehicle wheel that can either tend to slow the vehicle down or tend -7- #14746727vlAttorney Docket No. L0710.70115WQ00to speed it up; or exert a lateral force (as illustrated in Fig. 3) that tends to push the vehicle to the left or right.

[0030] A vehicle with one or more wheels that encounter a slope (e.g. that is a part of a hill or a bump) will typically tend to decelerate if one or more wheels are caused to travel uphill or accelerate if caused to move downhill. As discussed above in connection to Figs. 2-3, this may be caused by the reaction force applied by the ground on a rolling wheel that has a component parallel to the vehicle’s direction of travel. Similarly, road slope may induce forces in the lateral direction, or the direction normal to both the direction of gravity and the direction of travel of the vehicle. The wheel of a vehicle generally has low resistance to forces that tend to induce rotation about its rolling axis. Therefore, it is difficult for groundwheel interactions to apply a force on the vehicle unless the resulting rotational torque is opposed by moments imparted on the wheel by, for example, a propulsion motor, an engine, or brake pads.

[0031] However, a road surface that slopes laterally away from the wheel can alter the shape of the tire contact patch. Fig. 3 shows a tire 301 in contact with road 302. At the contact point, the combined forces acting on the wheel due to the vehicle's weight and the vertical forces due to the acceleration or deceleration of the vehicle body are represented by force vector 303. The ground reaction force is shown by arrow 304. Because force 303 and force 304 are not aligned, they create a moment on the wheel 301, which may have components in the lateral or longitudinal direction, or manifest as camber (overturning) or caster (steering) moments on the wheel assembly.

[0032] The effects of road events on a vehicle can be determined by modelling the vehicle’s behavior or the behavior of various components of the vehicle. For example, the component of the ground reaction force shown in Figs. 2a and 2b that is aligned with gravity can be determined using Eq. 1 :" <

[0033] Fzis the force 105 that is aligned with gravity, Mcis mass of the vehicle body, Mwis the mass of the wheel, g is the gravitational acceleration, azcis the instantaneous acceleration of the mass of the vehicle body in the vertical direction (i.e. aligned with gravity)-8- #14746727vlAttorney Docket No. E0710.70115WQ00and azwis the acceleration of the wheel in the vertical direction (i.e. aligned with gravity). In the simplified model represented by Eq. 1, the behavior of the mass of the vehicle and the mass of the wheel can be determined in a straightforward manner. However, for a full vehicle, the relevant model would need to be expanded into three dimensions to consider the normal force on each wheel. Such analysis using a full vehicle body model is well known in the art and frequently used.

[0034] The component of the ground reaction force 204 in the direction of travel, as illustrated in Fig. 2a may be approximated by assuming the force 204 is normal to the ground at the point of contact between the wheel and the ground. Force 205 (see Fig. 2b) can then be calculated asFx= -tan (a)Fz(2)

[0035] Where Fxis the component of reaction force 205 in the direction of travel and a is the angle between the road slope 104b and the horizontal 104c. This approximation is often sufficient but does not need to be used in this form if a better model of the force interaction is available. A model can be derived from a multi-body system model of the vehicle and suspension, or from a parametric model, or from a simple geometric calculation depending on the desired accuracy and the complexity of the particular suspension and vehicle.

[0036] Applying Eqs. 1 and 2 for the simplified quarter-car model, the acceleration imparted on the vehicle in the longitudinal direction due to the road slope may be determined by dividing the calculated force 205 by the total vehicle mass. In this approximation, if the vertical vehicle and wheel accelerations are ignored, Eq. 2 yields:the ratioof vertical change of road height over longitudinal road distance, or simply the slope of the road along the direction of travel, at the point of contact.

[0038] Typically, a vehicle’s suspension system at least partially establishes the limits and constraints of the path of one or more wheels relative to the vehicle chassis. This -9- #14746727vlAttorney Docket No. L0710.70115WQ00kinematic link between the two bodies is largely determined by the suspension links and joints and is typically designed to achieve certain goals in the behavior of the vehicle.

[0039] One example where such constraints are imposed is illustrated in Fig. 4, where a wheel 401 is linked to a vehicle body 402 via suspension element 403. As the vehicle moves left to right, element 403 constrains the wheel 401 to move along a straight-line path with respect to vehicle body 402, which in Fig. 4 is shown as inclined forward from the wheel at a predetermined angle. Therefore, when the vehicle encounters road event 404 and the wheel is pushed up, by the road surface 404, with respect to the vehicle body, wheel 401 moves according to the constraints imposed by suspension element 403. Due to the constraints in this example, the wheel needs to move forward in order to be able to move up, and / or the vehicle body 402 needs to move backward in order for the wheel to move up. As the suspension moves along arrow 405, the vehicle will experience a force applied on the vehicle along the direction of arrow 406 that attempts to move it along that direction.

[0040] In a typical vehicle, as a wheel moves relative to the vehicle chassis it follows a kinematic path that creates forces on the chassis that can be predicted if the motion of the wheel can be predicted. Using a model of the vehicle and predicting the vertical motion of the wheel in response to a specific road input (if the wheel remains in contact with the road surface), the resulting forces on the vehicle chassis in the direction of travel and in the direction orthogonal to both the direction of travel and the direction aligned with the gravitational force, along with forces in the vertical direction.

[0041] As an example of this kind of kinematic relationship, Fig. 5 illustrates the measured curves for a given passenger vehicle that relate the “Jounce” motion (relative motion between a wheel and a chassis component, which is generally considered positive if the wheel moves away from the chassis) and the “Longitudinal Motion” (which is measured along the nominal direction of travel of the vehicle and positive forward). In this example, a front and a rear wheel both move backwards with respect to the chassis as they move up, thus imparting a force on the chassis that pushes forward in proportion with the vertical accelerationFx= ~MwaXiW= Mwtan( / ?) q (4)-10- #14746727vlAttorney Docket No. E0710.70115WO00where Fxis the longitudinal force acting on the vehicle, Mwis the mass of the wheel, ax wis the longitudinal acceleration of the wheel, tan( / ?) is the tangent of the kinematic angle determining the longitudinal recession motion of the wheel with respect to the vehicle body, and q is the relative vertical acceleration of the wheel to the vehicle body.

[0042] It should be noted that Eq. 4 can be used to determine an approximate value of Fx. A more accurate model of the suspension motion may include motion of the vehicle itself, motion of multiple wheels, and the instantaneous suspension link forces impacted between the two bodies at any moment at a given position.

[0043] A different mechanism may apply to kinematic effects that change the rotation in the toe, or steering, direction of a wheel as the wheel moves relative to the vehicle chassis. As in the discussion above, a kinematic path of a wheel may induce steering of the wheel, for example through an inherent parameter called “bump steer.” As used herein, “bump steer” refers to the tendency of a vehicle’s steering wheels to steer themselves as they move up and down through the suspension travel. This phenomenon occurs when the suspension geometry causes the wheels to change direction without any input from the driver, such as when a wheel goes over bumps or dips in the road. Using a model of this relationship, and a model that predicts the motion of the vehicle, this unintended steering effect may be countered or neutralized.

[0044] It should be noted that kinematic relationships connecting wheels and vehicle chassis components may be treated as quasi-static and measured at low force, while compliance effects are the relative motions caused by force inputs as suspension components deform. Both are considered above and need not be separated as they can both be accounted for in the associated models.

[0045] Fig. 6 describes the steps of a process that may be used to mitigate the effects of road events on the vehicle. There are two possible series of steps shown for predicting aspects of an upcoming road segment, which may be used alternatively or in conjunction with each other. Step 601, of the process illustrated Fig. 6, involves measuring road data during previous drive sessions on a given road. The drive sessions may be performed by the same vehicle during multiple trips or multiple vehicles. Various sensors may be used to achieve-11- #14746727vlAttorney Docket No. L0710.70115WQ00this, including for example but not limited to, vehicle motion sensors (e.g. accelerometers, displacement sensors, and IMUs), and / or non-contact sensors, e.g. LiDAR, Laser, radar, or vision. "The process may involve normalization and localization, which includes collecting road content from various locations or focusing on specific subsets of road content.

[0046] At step 602 of the process illustrated in Fig. 6, road content is extracted from the driving data. This may be performed by determining a vertical road profile, by extracting specific road features, or by measuring certain road characteristics or anomalies. The data at this step may also be stored in a database or map and prepared for use by other vehicles. This step may involve using crowd sourced information collected from multiple vehicles and analyzed offline in the cloud. Alternatively, some or all of the analysis may be performed in a target vehicle. In some embodiments, a vehicle may drive over a specific road section one or more times, collect and process the data, and store it for use at another time when traversing the same road. In another embodiment, a vehicle may drive over a specific road section one or more times and send the data, unprocessed, partially processed, or after processing, to a connected processor in the cloud that may process and store it for use by the same or another vehicle traversing the same road at a future time.

[0047] At step 603, the vehicle receives or loads the preview information relative to a road segment it is about to traverse and uses a localization method to align itself within the data in order to have accurate information about the surface of the upcoming road and the timing of when the vehicle is expected to encounter a road event. Alignment methods may include absolute localization methods using GNSS positioning devices of any kind, relative localization methods using terrain information or external sensor information, or combinations thereof.

[0048] Another possible series of steps for acquiring road preview information is to directly use a non-contact sensor on-board the vehicle to characterize or measure aspects of the upcoming road as shown at step 604. Such sensors may include non-contact sensors such as LiDAR, radar, laser, or other time-of-flight sensors, or single or stereo camera systems, or other sensors capable of characterizing or measuring aspects of the upcoming road segment ahead of the vehicle with sufficient precision and in a timely manner. For example, for distances of 1-15 meters, (or 1-20 meters or 1-50 meters) obtaining road preview information -12- #14746727vlAttorney Docket No. L0710.70115WQ00may include measuring vertical excursions in the positive or negative directions from the nominal road surface of 0.5 meters, 0.1 meters or less and a resolution in the direction normal to the plane of the road that is 0.01 meters or better, or 0.05 meters or better. However, measurements outside the ranges indicated above are contemplated as the disclosure is not so limited.

[0049] At step 605 the signal from the sensor is processed to derive road content. This may include steps such as converting output from two individual sensors to create a 3D road profile, or calculating the expected path of each wheel and deriving the road contour along one or more wheel paths, or processing the sensor data to extract specific recognized patterns such as speed bumps or potholes, and may include estimating the properties of such recognized patterns.

[0050] At step 606 the process involves using the information from sensors and / or previous data to calculate at least a partial upcoming road content. This content may be in the form of a vertical road profile, a road camber profile, a road roughness or friction profile, or it may contain more discrete signals related to specific upcoming discrete events such as speed bumps, potholes, or other events as desired.

[0051] At step 607, information about aspects of the upcoming road surface may be used in conjunction with vehicle state parameters, e.g., vehicle speed, lateral acceleration, yaw rate, to calculate a predicted effect on the vehicle. For example, as discussed above, the change in road slope, encountered by a wheel, may be a road event the characteristics of which may have been determined prior to the encounter. This information may be used to calculate an expected: longitudinal acceleration to be imparted to the vehicle when it traverses the road event, the magnitude of the induced steering effect, and / or a lateral force due to expected relative motion between a wheel and a vehicle. This calculation may be performed for each wheel, each axel, or the entire vehicle at any given time. In some cases, these effects may be additive in which case they may be calculated individually and added to determine a total response. However, there may be specific cases where a particular combination of effects is relevant, or where a particular combination of motions is the only possible effect, or where a particular combination of responses is the only controllable option. For example, some types of suspensions can only move connected wheels in concert, such as -13- #14746727vlAttorney Docket No. L0710.70115WQ00solid axle suspensions where the two wheels are connected with an axle cannot move independently from each other and thus the effect of a road input on one wheel of a solid axle may be combined with the effect of the respective road on the other wheel on the same solid axle. As another example, steering systems are not typically able to steer an individual wheel and thus a response that requires steering should be calculated at least for the two wheels connected in a steering system, such that for example the expected steering effect on the left front wheel and the expected steering effect on the right front wheel should both be used as inputs to calculate an appropriate steering response.

[0052] At step 608, the appropriate response is determined based on the predicted effect. For example, the appropriate response may be to counter the expected effect by applying a longitudinal acceleration to one or more wheels of a vehicle in response to an anticipated longitudinal input in order to make the vehicle drive more smoothly. The calculated response may need to consider, e.g., current vehicle states, driver intentions, and other factors to minimize or avoid possible disturbances. The calculated response may also be filtered in advance to select a desired frequency range in which to apply the response, or to remove sensor or estimation noise from the prediction. The calculated response may also need a plausibility calculation to avoid creating unwanted outputs in the case of an erroneous prediction. An important consideration at this step may be to shape the response such that it achieves a desired effect. In some embodiments and for some systems, a desired effect may be the full cancellation of an input, but in other cases a desired effect may be only partial cancellation, or cancellation of only some components, or a simple smoothing out of the vehicle’s response. This desired outcome may also differ in time or with use case scenarios, for example during maneuvers, when the user selects a given drive mode, or at speeds or speed ranges. In some cases, desired outcomes may be correlated with different vehicle states, user selections, and other considerations in a map.

[0053] At step 609, the response may be applied to the vehicle by actuating an actuation system that produces the desired response. There are several important considerations during this step that may be taken into account as desired. In some embodiments, the application of the response may be modified to account for the actuation applying the response. For example, to achieve a desired steering effect it may be important-iq- #14746727vlAttorney Docket No. L0710.70115WQ00to determine the dynamics and response characteristics of the steering system in order to achieve the desired overall effect. This may allow an algorithm operating in a microprocessor-based controller to pre-emptively correct for the behavior of an actuation system and thus may compensate for possible shortcomings due to a predictive nature of the process. As another example, a propulsion motor may be used to correct for an expected longitudinal input from a road event, and the characteristic response time and shape of the propulsion system may be taken into account at this step to achieve the desired effect.

[0054] An actuation system may include steering systems, brake systems, suspension systems, electric propulsion systems, front and rear steering systems, or other systems able to affect the motion of a vehicle. For example, actuation systems may include: propulsion motors in electric and hybrid vehicles, particularly motors that can drive an individual wheel or axle; the steering systems, particularly when they are independently operatable or steer-by-wire, but also when they can be affected through power steering or electric power steering methods, and also rear steering systems where present; and the brake systems, particularly where operated as brake-by-wire and thus independently controllable, but also when operated centrally.

[0055] It is also important at this step to adjust the timing of the actuation such that the desired response aligns with the predicted effect. For example, an actuation system may have a known or predictable response lag, for example 50 milli-seconds or any other measured or calculated time lag, or a phase lag that can be approximated with a time delay. The command to such systems may be anticipated by at least a portion of the lag in order for the resulting effect to fully or at least partially cancel the expected undesirable motion. The actuation system’s dynamics may also be considered and can often be modeled in order to predict the response in time and / or frequency domain such as to compensate for any dynamics that would otherwise negatively affect the response. An example of such a compensation is a system that may have an inherent time delay and respond slowly; if this time delay is expected to affect the desired response, the command signal may be anticipated in order to pre-empt the time delay. Another example may be a response that is able to follow low-frequency commands with some level of accuracy, but higher frequency commands with a lower level of accuracy. For example, a pump system may be considered that has a response-15- #14746727vlAttorney Docket No. L0710.70115WO00that rolls off with frequency, for example after approximately 4 Hz, and thus creates less pressure for high frequency commands. In such cases, below 4Hz; compensation for such behavior may include, for example, increasing the command force for content above 4 Hz and not for content below 4Hz, such that the expected response more faithfully follows the desired response. Accordingly, shortcomings of actuation systems may at least partly be compensated which may allow higher performance from lower cost actuation systems.

[0056] Additionally, any actuation systems that may have an adverse effect on safety may avoided, for example, by imposing limits on the response, and possibly modifying these limits with given use case scenarios such as at elevated speed, during a turn, etc.

[0057] The system may also be set up to learn and improve over time by comparing the outcome once a response was applied in step 609 to the desired outcome used to calculate response 608. This may for example be useful to estimate the response characteristics of an actuation system and adapt them over time, or to improve the estimation of a sensor system used in step 601. It may also be possible to use this learning process to identify system failures of a sensor or actuator.

[0058] Fig. 7 shows an example response in a simulated multi-body vehicle model. In this model, as the vehicle interacts with a road event, the upcoming road slope is used to predict a longitudinal force input from each wheel, and a propulsion motor adjustment is used to cancel the expected acceleration within a desired frequency band. Fig. 7 shows that a significantly lower longitudinal acceleration 701 is observed using a propulsion motor to counter the expected longitudinal force input 702.

[0059] The above-described embodiments of the technology described herein can be implemented in any of numerous ways. For example, the embodiments may be implemented using hardware, software or a combination thereof. When implemented in software, the software code can be executed on any suitable processor or collection of processors, whether provided in a single computer or distributed among multiple computers. Such processors may be implemented as integrated circuits, with one or more processors in an integrated circuit component, including commercially available integrated circuit components known in the art by names such as CPU chips, GPU chips, microprocessor, microcontroller, or co-processor. Alternatively, a processor may be implemented in custom circuitry, such as an ASIC, or -16- #14746727vlAttorney Docket No. L0710.70115WQ00semicustom circuitry resulting from configuring a programmable logic device. As yet a further alternative, a processor may be a portion of a larger circuit or semiconductor device, whether commercially available, semi-custom or custom. As a specific example, some commercially available microprocessors have multiple cores such that one or a subset of those cores may constitute a processor. Though, a processor may be implemented using circuitry in any suitable format.

[0060] Further, it should be appreciated that a computer may be embodied in any of a number of forms, such as a rack-mounted computer, a desktop computer, a laptop computer, or a tablet computer. Additionally, a computer may be embedded in a device not generally regarded as a computer but with suitable processing capabilities, including a Personal Digital Assistant (PDA), a smart phone or any other suitable portable or fixed electronic device.

[0061] Also, a computer may have one or more input and output devices. These devices can be used, among other things, to present a user interface. Examples of output devices that can be used to provide a user interface include printers or display screens for visual presentation of output and speakers or other sound generating devices for audible presentation of output. Examples of input devices that can be used for a user interface include keyboards, and pointing devices, such as mice, touch pads, and digitizing tablets. As another example, a computer may receive input information through speech recognition or in other audible format.

[0062] Such computers may be interconnected by one or more networks in any suitable form, including as a local area network or a wide area network, such as an enterprise network or the Internet. Such networks may be based on any suitable technology and may operate according to any suitable protocol and may include wireless networks, wired networks or fiber optic networks.

[0063] Also, the various methods or processes outlined herein may be coded as software that is executable on one or more processors that employ any one of a variety of operating systems or platforms. Additionally, such software may be written using any of a number of suitable programming languages and / or programming or scripting tools, and also may be compiled as executable machine language code or intermediate code that is executed on a framework or virtual machine.-17- #14746727vlAttorney Docket No. L0710.70115WQ00

[0064] In this respect, the embodiments described herein may be embodied as a computer readable storage medium (or multiple computer readable media) (e.g., a computer memory, one or more floppy discs, compact discs (CD), optical discs, digital video disks (DVD), magnetic tapes, flash memories, circuit configurations in Field Programmable Gate Arrays or other semiconductor devices, or other tangible computer storage medium) encoded with one or more programs that, when executed on one or more computers or other processors, perform methods that implement the various embodiments discussed above. As is apparent from the foregoing examples, a computer readable storage medium may retain information for a sufficient time to provide computer-executable instructions in a non-transitory form. Such a computer readable storage medium or media can be transportable, such that the program or programs stored thereon can be loaded onto one or more different computers or other processors to implement various aspects of the present disclosure as discussed above. As used herein, the term "computer-readable storage medium" encompasses only a non-transitory computer-readable medium that can be considered to be a manufacture (i.e., article of manufacture) or a machine. Alternatively, or additionally, the disclosure may be embodied as a computer readable medium other than a computer-readable storage medium, such as a propagating signal.

[0065] The terms “program” or “software” are used herein in a generic sense to refer to any type of computer code or set of computer-executable instructions that can be employed to program a computer or other processor to implement various aspects of the present disclosure as discussed above. Additionally, it should be appreciated that according to one aspect of this embodiment, one or more computer programs that when executed perform methods of the present disclosure need not reside on a single computer or processor but may be distributed in a modular fashion amongst a number of different computers or processors to implement various aspects of the present disclosure.

[0066] Computer-executable instructions may be in many forms, such as program modules, executed by one or more computers or other devices. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Typically, the functionality of the program modules may be combined or distributed as desired in various embodiments.-18- #14746727vlAttorney Docket No. L0710.70115WQ00

[0067] Also, data structures may be stored in computer-readable media in any suitable form. For simplicity of illustration, data structures may be shown to have fields that are related through location in the data structure. Such relationships may likewise be achieved by assigning storage for the fields with locations in a computer-readable medium that conveys the relationship between the fields. However, any suitable mechanism may be used to establish a relationship between information in fields of a data structure, including through the use of pointers, tags or other mechanisms that establish relationship between data elements.

[0068] Various aspects of the present disclosure may be used alone, in combination, or in a variety of arrangements not specifically discussed in the embodiments described in the foregoing and is therefore not limited in its application to the details and arrangement of components set forth in the foregoing description or illustrated in the drawings. For example, aspects described in one embodiment may be combined in any manner with aspects described in other embodiments.

[0069] Also, the embodiments described herein may be embodied as a method, of which an example has been provided. The acts performed as part of the method may be ordered in any suitable way. Accordingly, embodiments may be constructed in which acts are performed in an order different than illustrated, which may include performing some acts simultaneously, even though shown as sequential acts in illustrative embodiments.

[0070] Further, some actions are described as taken by a “user.” It should be appreciated that a “user” need not be a single individual, and that in some embodiments, actions attributable to a “user” may be performed by a team of individuals and / or an individual in combination with computer-assisted tools or other mechanisms.-19- #14746727vl

Claims

Attorney Docket No. L0710.70115WQ00CLAIMSWhat is claimed:

1. A method of operating a vehicle with a multiplicity of wheels, the method comprising:traveling along a road surface that includes a road event;interacting with the road event with a first wheel of the multiplicity of wheels of the vehicle;as a result of the interaction, inducing a reaction force on the vehicle in the direction of travel;with an algorithm, operating in a microprocessor-based controller, generating a command, for the vehicle’s propulsion system, to change a torque being applied to at least one wheel of the vehicle;implementing the command; andmitigating an effect of the reaction force on the vehicle.

2. The method of claim 1, wherein the torque is applied to the first wheel.

3. The method of claim 1, wherein the torque is applied to at least a second wheel.

4. The method of one of claims 1-3, wherein the reaction force is a retarding force and the torque applied to the at least one wheel mitigates the effect of the retarding force.

5. The method of one of claims 1-3, wherein the reaction force is a driving force and the torque applied to the at least one wheel mitigates the effect of the driving force.

6. The method of one of claims 1-5, wherein the road event is a bump.

7. The method of one of claims 1-5, wherein the road event is a pothole.

8. The method of one of claims 1-7, further comprising receiving information about a location of the road event relative to the first wheel and timing the implementation of the command at least partially based on the information.-20- #14746727vlAttorney Docket No. L0710.70115WQ009. The method of claim 8, wherein the information is based at least partially on data received from an on-board non-contact sensor system selected from the group consisting of a LiDAR sensor, a radar sensor, a laser sensor, a time-of-flight sensor, a single camera, and stereo camera.

10. The method of claim 8, wherein the information is based at least partially on previously collected road surface data received from a database in the vehicle.

11. The method of claim 8, wherein the information is based at least partially on crowd sourced data received from a cloud database.

12. A method of operating a vehicle with a multiplicity of wheels, the method comprising:traveling along a road surface that includes a road event;interacting with the road event with a first wheel of the multiplicity of wheels of the vehicle;as a result of the interaction, changing a position of the first wheel relative to the vehicle body;as a result of the change of position, applying a steering torque to the first wheel; with an algorithm operating in a microprocessor-based controller, generating a steering command to counteract the steering torque;implementing the steering command with a steering actuator; and mitigating an effect of the steering torque.

13. The method of claim 12, wherein the road event is a bump.

14. The method of claim 12, wherein the road event is a pothole.

15. The method of one of claims 12-14, further comprising receiving information about a location of the road event relative to the first wheel and timing the implementation of the command at least partially based on the information.

16. The method of one of claims 12-14, wherein the information is based at least partially on data received from an on-board non-contact sensor system selected from the group -21- #14746727vlAttorney Docket No. L0710.70115WQ00consisting of a LiDAR sensor, a radar sensor, a laser sensor, a time-of-flight sensor, a single camera, and stereo camera.

17. The method of one of claims 12-14, wherein the information is based at least partially on previously collected road surface data received from a database in the vehicle.

18. The method of one of claims 12-14, wherein the information is based at least partially on crowd sourced data received from a cloud database.

19. The method of one of claims 12-18, wherein the first wheel is a front steering wheel.

20. The method of one of claims 12-18, wherein the first wheel is a rear steering wheel.

21. A method of operating a vehicle with four wheels, the method comprising:traveling along a road surface that includes a road event;interacting with the road event with a first wheel at a first time, wherein the first wheel is a front wheel;interacting with the road event with a second wheel, wherein the second wheel is a rear steering wheel;as a result of the interaction with the second wheel, changing a position of the second wheel relative to the vehicle body;as a result of the change of position, applying a steering torque to the second wheel;with an algorithm operating in a microprocessor-based controller, generating a steering command to counteract the steering torque;implementing the steering command with a steering actuator associated with the second wheel; andmitigating an effect of the steering torque on the second wheel.

22. The method of claim 21, further comprising timing the implementation of the command at least partially based on the first time, a distance between the first wheel and the second wheel, and a speed of the vehicle.-22- #14746727vl

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