Method for creating a gap under a wheel

Abstract

A control system (300) for controlling an active suspension system (104) of a vehicle (100), the control system comprising one or more controllers (301), wherein the control system is configured to: determine (804) that an entry condition is satisfied; in dependence on the entry condition being satisfied, send (806) a request to the active suspension system to create a gap under a first wheel (FL, RR) of the vehicle but not under a plurality of other wheels (FR, RL) of the vehicle.

Description

Technical Field

[0001] This disclosure relates to methods for creating clearance under wheels. In particular, but not exclusively, this disclosure relates to methods for controlling an active suspension system of a vehicle to create clearance at least under the first wheel of the vehicle to help recover a vehicle stuck in terrain. Background Technology

[0002] When driving on a surface containing independently movable particles, such as sand or gravel (or in some cases, snow), a vehicle may get stuck. As an example, this could occur due to excessive wheel spin from a slipping wheel, which displaces particles beneath the wheel, causing the vehicle to "sink" into the surface.

[0003] The buildup of particles around the wheels creates drag, which, if greater than the available traction, will bring the vehicle to a stop. This can be exacerbated when the vehicle is "bellied out." This is because the contact patch on the wheels is reduced, and additional drag is encountered due to friction from the direct contact between the vehicle chassis and the surfaces the vehicle is traveling on.

[0004] Restoring a vehicle without a recovery board, shovel, or winch requires advanced driving skills. The driver can deflate the tires and slowly spin the wheel while moving the steering wheel left and right to try to climb out of the surface. Summary of the Invention

[0005] The purpose of this invention is to address one or more of the disadvantages associated with the prior art.

[0006] According to one aspect of the invention, a control system for controlling an active suspension system of a vehicle is provided, the control system comprising one or more controllers, wherein the control system is configured to: determine that an entry condition is met; and, based on the satisfaction of the entry condition, send a request to the active suspension system to generate clearance under a first wheel of the vehicle but not under a plurality of other wheels of the vehicle. The advantage is that a reasonable body-to-surface clearance is maintained to prevent the vehicle from getting stuck or bottoming out. That is, the vehicle's ride height does not decrease significantly or oscillate.

[0007] In some examples, the request is configured to control the suspension actuators of the first wheel to lift the first wheel. Alternatively, the request is also configured to control the suspension actuators of multiple other wheels to increase the vertical distance by which the first wheel can be lifted above the surface.

[0008] In some examples, the first wheel is located at a first lateral side of the vehicle and at a first longitudinal end of the vehicle, and wherein the plurality of other wheels include at least: a second wheel located at a second lateral side of the vehicle and at a first longitudinal end of the vehicle; and a third wheel located at a first lateral side of the vehicle and at a second longitudinal end of the vehicle.

[0009] In some examples, the request is configured to create a gap under a pair of diagonal wheels, including the vehicle’s first and fourth wheels, wherein the fourth wheel is located at a second lateral side and at a second longitudinal end, diagonally opposite the first wheel.

[0010] In some examples, the request is configured to create a gap under the first wheel of the vehicle but not under the second, third, and fourth wheels, wherein the fourth wheel is located at the second lateral side and at the second longitudinal end, diagonally opposite the first wheel.

[0011] In some examples, the control system is configured to send a second request to the active suspension system to create clearance under the second wheel but not under the first and fourth wheels.

[0012] In some examples, the second request is configured to create a gap under a pair of diagonal wheels, which include a second wheel and a third wheel.

[0013] In some examples, the second request is configured to create a gap under the second wheel but not under the first, third, and fourth wheels, and wherein the control system is configured to: send a third request to the active suspension system to create a gap under the third wheel but not under the first, second, and fourth wheels; and send a fourth request to the active suspension system to create a gap under the fourth wheel but not under the first, second, and third wheels.

[0014] In some examples, the request includes a force request configured to overcome the restoring force associated with the first round to substantially remove the grounding imprint beneath the first round.

[0015] In some examples, the control system is configured to control the active suspension system to reduce the spring stiffness associated with the first wheel when the active suspension system creates a gap.

[0016] In some examples, the fulfillment of the entry condition includes receiving a user-initiated request to create a gap below the first round.

[0017] In some examples, the user-initiated request is configured to identify the first round as the round selected by the user, and / or the control system is configured to control the selection of the first round in response to the user-initiated request.

[0018] In some examples, the entry condition needs to be satisfied to determine that the vehicle has not moved.

[0019] In some examples, the entry conditions require one or more of the following: determining that the vehicle doors are closed; determining that one or more occupants are inside the vehicle; or determining that the vehicle is secured to prevent movement.

[0020] In some examples, the control system is configured to hold the request to maintain the gap below the first round for no more than a set duration or until a second condition is met.

[0021] In some examples, the second condition is: a transition condition configured to create a gap under different wheels of the vehicle; or an exit condition that depends at least on a user-initiated termination request.

[0022] In some examples, the fulfillment of the conversion conditions depends on a request initiated by the user.

[0023] In some examples, the conversion condition needs to be satisfied to determine that the vehicle has not moved.

[0024] In some examples, the conversion condition requires one or more of the following to be satisfied: determining that the vehicle doors are closed; determining that one or more occupants are inside the vehicle; or determining that the vehicle is secured to prevent movement.

[0025] In some examples, the control system is configured to send a request to the torque source to make the first wheel rotate less than one full revolution while maintaining the request for clearance under the first wheel.

[0026] In some examples, the control system is configured to send a time-varying request to the active suspension system to induce oscillations in the first wheel during the first wheel rotation.

[0027] According to another aspect of the present invention, a vehicle including a control system is provided.

[0028] According to another aspect of the present invention, a method for controlling an active suspension system of a vehicle is provided, the method comprising: determining that an entry condition is met; and, based on the satisfaction of the entry condition, sending a request to the active suspension system to generate clearance under a first wheel of the vehicle but not under a plurality of other wheels of the vehicle.

[0029] According to another aspect of the invention, computer software is provided that, when executed, is arranged to perform the method. According to another aspect of the invention, a non-transitory computer-readable medium is provided comprising computer-readable instructions that, when executed by a processor, cause any or more of the methods described herein to be performed.

[0030] The one or more controllers may collectively include: at least one electronic processor having an electrical input for receiving information; and at least one electronic memory device electrically coupled to the at least one electronic processor and having instructions stored in the at least one electronic memory device; and wherein the at least one electronic processor is configured to access the at least one memory device and execute the instructions on the at least one memory device to cause the control system to perform the method.

[0031] Within the scope of this application, it is expressly intended that the various aspects, embodiments, examples, and alternatives set forth in the foregoing paragraphs, claims, and / or the following description and drawings, and in particular their respective features, may be employed independently or in any combination falling within the scope of the appended claims. That is, unless these features are incompatible, all embodiments and / or features of any embodiment may be combined in any manner and / or combination falling within the scope of the appended claims. The applicant reserves the right to amend any originally filed claim or accordingly file any new claim, including the right to modify any originally filed claim to any feature subordinate to and / or incorporated into any other claim, although not initially claimed in this manner. Attached Figure Description

[0032] One or more embodiments of the invention will now be described by way of example only with reference to the accompanying drawings, in which:

[0033] Figure 1 The illustration shows an example vehicle and coordinate system;

[0034] Figure 2A , Figure 2B The illustration shows a wheel that gets stuck in a surface and then recovers from it.

[0035] Figure 3 The illustration shows an example control system;

[0036] Figure 4 An example of a non-transitory computer-readable storage medium is illustrated;

[0037] Figure 5 An example of a vehicle's active suspension system is illustrated.

[0038] Figure 6A , Figure 6B , Figure 6C The illustration shows an example of an active suspension system creating clearance under two pairs of diagonally opposite wheels;

[0039] Figure 7A , Figure 7B , Figure 7C , Figure 7D , Figure 7E The illustration shows an example of how an active suspension system sequentially creates clearances under each wheel; and

[0040] Figure 8 The example method is illustrated. Detailed Implementation

[0041] Figure 1 An example of a vehicle 100 that can implement embodiments of the present invention is illustrated. In some, but not all, examples, vehicle 100 is a passenger vehicle, also referred to as a car or automobile. In other examples, embodiments of the present invention may be implemented for other applications, such as industrial vehicles or commercial vehicles. Vehicle 100 has a body 102 (sprung mass) supported by suspension.

[0042] Figure 1 The diagram also illustrates a coordinate system. The x-axis is the longitudinal axis. Rotation of the vehicle body around the x-axis, indicated by "R", is roll. The y-axis is the lateral axis. Rotation of the vehicle body around the y-axis, indicated by "P", is pitch. The z-axis is the vertical axis. Rotation of the vehicle body around the z-axis, indicated by "Y", is yaw.

[0043] Figure 2A The diagram schematically illustrates a wheel W stuck in the surface of a particle. Due to excessive wheel spin, the wheel displaces the particles below, in front of, and behind it, causing the wheel to settle below the pile of displaced particle material, so that if the wheel is to continue moving forward, it must climb over and over this pile. Figure 2A In the example shown, the angle of the pile in front of the wheel is too steep to climb out, especially since the soft surface provides insufficient traction.

[0044] Figure 2B The illustration schematically depicts a wheel crawling out of the particle surface because the surface angle is much shallower. An effective way to reduce the angle is manually (usually by digging with a shovel, etc.) or by using the swishing motion of the wheel's tire tread to move some of the particles beneath the wheel.

[0045] The obstacle that allows particles to move beneath the wheel is that there is typically no ground clearance beneath the wheel. If the wheel can be lifted at least temporarily to reduce or remove its contact with the ground, a gap is created beneath the wheel into which particles can flow.

[0046] In at least some embodiments of the invention, the suspension of vehicle 100 is an active suspension system configured to lift the wheels toward the vehicle body 102 and push the wheels away from the vehicle body 102. For example, the active suspension system can lift the wheels off the surface while the other wheels do not lower the vehicle's ride height and prevent the vehicle from getting stuck. This provides an opportunity for particles to be kicked out or otherwise displaced or moved under the wheels, allowing the wheels to climb off the surface.

[0047] In cases where particles cannot flow beneath the wheel on their own (e.g., snow) or are worn down beneath it by the wheel's rotation, the user (e.g., a driver) can manually move the particles while the wheel is being lifted. Alternatively, the user can insert a recovery plate under the lifted wheel. The recovery plate is a long (e.g., 50-150 cm), narrow (e.g., < 1 m), thin (e.g., < 10 cm), and approximately flat object with a high-friction traction surface, such as a perforated or corrugated surface.

[0048] Once the traction of one wheel has been increased, the other wheels can be lifted in sequence.

[0049] The above concept is referred to in this document as a “recovery mode” (e.g., a grainy surface recovery mode), and in some examples it can be used to help a stuck vehicle 100 get out without assistance.

[0050] The active suspension system 104 and the control system 300 will be described first.

[0051] Figure 3 The control system 300 includes a controller 301. In other examples, the control system 300 may include multiple controllers on and / or outside the vehicle 100. In some examples, the control system 300 or controller 301 may be provided as part of the active suspension system 104.

[0052] Figure 3 The controller 301 includes at least one processor 304; and at least one memory device 306 electrically coupled to the electronic processor 304 and having instructions 308 (e.g., a computer program) stored in the at least one memory device 306. The at least one memory device 306 and the instructions 308 are configured to cause any or more methods described herein to be executed via the at least one processor 304. The processor 304 may have an interface 302, such as electrical input / output I / O or electrical inputs for receiving information and interacting with external components such as the active suspension system 104.

[0053] Figure 4 The illustration shows a non-transitory computer-readable storage medium 400 including instruction 308 (computer software).

[0054] Figure 5 The illustration shows an example implementation of the active suspension system 104.

[0055] The active suspension system 104 includes a left front active suspension 106 for the first wheel FL at the first lateral side (left) and the first longitudinal end (front) of the vehicle 100; a right front active suspension 116 for the second wheel FR at the second lateral side (right) and the first longitudinal end (front) of the vehicle 100; a left rear active suspension 108 for the third wheel RL at the first lateral side (left) and the second longitudinal end (rear) of the vehicle 100; and a right rear active suspension 118 for the fourth wheel RR at the second lateral side (right) and the second longitudinal end (rear). The active suspension for each wheel of the vehicle 100 (e.g., quarter / corner section) can be individually controllable.

[0056] Figure 5 The diagram also shows a torque source 103, such as an internal combustion engine or an electric motor, for driving at least some of the wheels.

[0057] The active suspension for each corner of vehicle 100 includes actuator 502.

[0058] Actuator 502 may be a hydraulic actuator, such as a hydraulic fluid-filled chamber that houses a piston. One end of actuator 502 is connected to a wheel and the other end is connected to vehicle body 102. Spring 504 (e.g., a coil spring or a pneumatic spring) may be in a balanced state and act parallel to actuator 502.

[0059] When the vehicle suspension is undisturbed, the piston of the hydraulic actuator 502 is seated in a specific neutral position in the chamber.

[0060] The piston can move in either direction on the chamber side, for example, due to road disturbances that compress actuator 502. The piston can displace fluid from the chamber into a hydraulic circuit (not shown). The fluid exerts a restoring force to resist the piston's movement. Energy can be added to and / or extracted from actuator 502 by pumping fluid and / or controlling valves to regulate the fluid pressure on both sides of the piston.

[0061] Therefore, the control system 300 can dynamically control the restoring force to resist the displaced piston. This force is equivalent to the spring force of a coil spring resisting displacement. Dynamic control allows the force-displacement relationship to be changed to adapt to driving scenarios. Energy can be added or removed rapidly, for example, within tens of milliseconds. To control the spring force, the control system 300 can output a force request that depends on the sensed wheel travel (displacement / articulation of the wheel to the body).

[0062] The dynamic damping characteristics of actuator 502 can be modified by controlling a fluid valve at the contraction point, which regulates the rate at which fluid is delivered into and out of actuator 502 by the movement of a piston.

[0063] Furthermore, energy can be added to or removed from actuator 502 to cause actuator 502 to extend or retract. Figure 5 This allows the distance from the wheel to the vehicle body to be changed independently at different ends and / or different corners of the vehicle 100.

[0064] The above example relates to a hydraulic actuator 502, and in other embodiments, the actuator may be an electromagnetic actuator or a pneumatic actuator, etc.

[0065] exist Figure 5 In, but not necessarily in all examples, spring 504 includes an active spring, such as a pneumatic spring, which enables control of ride height. Control system 300 can be configured to pump gas (e.g., air) into or out of pneumatic spring 504 to control ride height. The air leveling function of control system 300 attempts to maintain a set ride height regardless of vehicle load, and achieves this by changing the volume of air and thus changing the air pressure to maintain the set ride height.

[0066] Energy can be added to or removed from the pneumatic spring 504 to increase or decrease its volume. Increasing the volume can lift the vehicle body 102 along the z-axis. Figure 5 This allows the distance from the wheel to the vehicle body to be changed independently at different ends and / or different corners of the vehicle 100.

[0067] Additionally or alternatively, spring 504 may include a passive spring (e.g., a coil spring) or may be omitted entirely.

[0068] The control of the active suspension system 104 relies on one or more sensors. For example, wheel travel can be sensed by a wheel-to-body displacement sensor 514 (a sensor based on suspension displacement). The wheel-to-body displacement sensor 514 is placed somewhere on the active suspension and can sense the wheel position along an arc defined by the suspension geometry. An example of the wheel-to-body displacement sensor 514 is a rotary potentiometer attached to a rod, wherein one end of the rod is connected to the vehicle body 102 and the other end is connected to a suspension link.

[0069] In some examples, the control system 300 determines the wheel travel and / or its associated derivative more accurately by fusing information from the wheel-to-body displacement sensor 514 with information from the hub accelerometer.

[0070] The pressure in the pneumatic spring 504 can be sensed to indicate the weight on the wheel.

[0071] In at least some examples, the control system 300 is configured to control the active suspension system 104 by sending force requests to the active suspension or the underlying controller of the active suspension. The force request can be an arbitrated force request based on requests from various requesters and information from various sensors.

[0072] Figure 5 The illustration shows other optional features that can interact with the control system 300 to request influence calculations. These features include any one or more of the following:

[0073] - Wheel speed sensor 512 for each wheel. In the example implementation, wheel speed sensor 512 is part of the anti-lock braking system (ABS).

[0074] - A hub-type accelerometer 516 for each wheel, which is connected to the unsprung mass of the vehicle 100.

[0075] - Human-Machine Interface (HMI) 520. This refers to any of the various input devices and input / output devices available to the driver, such as touchscreens, displays, hardware switches / sliders / selectors, etc.

[0076] - At least one body accelerometer 522 is coupled to the body 102 (sprung mass). Specific examples include a 3DOF or 6DOF inertial measurement unit (IMU). The unit may include an accelerometer or a set of multi-axis accelerometers.

[0077] - Tire Pressure Monitoring System (TPMS) 524, which includes tire pressure monitors for each wheel.

[0078] Figures 6A to 7E The illustration shows an example implementation of the "recovery mode". In each of these examples, a reasonable gap between the body and the surface is maintained to prevent the vehicle from getting stuck and bottoming out. That is, the driving height of vehicle 100 does not decrease significantly or fluctuate.

[0079] Figures 6A to 6C The illustration shows a first example of recovery mode. Figure 6A , Figure 6B This is a schematic diagram of the wheels FL, FR, RL, RR and the body 102.

[0080] In this example, actuator 502 is controlled to lift the first set of wheels (pairs) upward at a first diagonal corner of vehicle 100 to create a gap beneath the first set of wheels, and simultaneously push the second set of wheels (pairs) downward at a second diagonal corner of vehicle 100. Thus, one set of wheels is lifted / pulled (unweighted / unloaded), while the other set of wheels is pushed (weighted / loaded). One or both wheels in each set are driven wheels.

[0081] Creating clearance refers to reducing or removing the contact patch between the wheel and the surface (tire and surface). This creates gaps (spaces) in which surface particles can flow. The wheel can maintain a very small contact patch with the surface or can be lifted completely off the surface, depending not only on suspension performance but also on how deeply the wheel is embedded. Therefore, the request to roughly remove the contact patch can be interpreted as a force request high enough to lift the wheel completely off a calibrated, level surface, but this force request may or may not be sufficient when the wheel is partially embedded in a granular surface.

[0082] Lifting a wheel refers to a force request that reduces the wheel-to-body distance relative to a potential / pre-existing target wheel. Pushing a wheel refers to a force request that increases the wheel-to-body distance relative to a potential / pre-existing target. Lifting a wheel may include retracting an actuator 502 of its associated suspension. Pushing a wheel may include extending an actuator 502 of its associated suspension. It should be noted that whether retraction or extension is necessary depends on the type of mechanism that links the actuator 502 to the wheel. If the vehicle has space to pitch slightly around a pair of wheels still pressed against the ground, lifting a pair of diagonal wheels facilitates lifting an additional wheel.

[0083] Figure 6A The diagram illustrates the first state, in which the right front wheel FR and the left rear wheel RL are lifted upwards (towards the vehicle body 102) as a diagonal pair, while the left front wheel FL and the right rear wheel RR are pushed downwards (away from the vehicle body 102) as a diagonal pair. The control system 300 can send a first force request, including the force requests of each wheel, to adopt the first state.

[0084] Figure 6B The diagram illustrates the second state, where the right front wheel FR and the left rear wheel RL are pushed downwards as a diagonal pair, while the left front wheel FL and the right rear wheel RR are lifted upwards as a diagonal pair. The control system 300 can send a second force request, including the force requests for each wheel, to adopt the second state.

[0085] The pushed wheels reduce the force required to lift the first sub-group of wheels by performing some work when lifting vehicle 100. Pushing the unlifted wheels also helps prevent the vehicle body 102 from getting stuck and bottoming out by maintaining the current average ground clearance. In another embodiment, the unlifted wheels are not pushed downwards and are maintained at their pre-existing target wheel distance from the body. In another embodiment, the downward-pushed wheels FL and RR can provide sufficient clearance under wheels FR and RL, even without lifting wheels FR and RL.

[0086] The force request can be configured to lift the wheel off a flat, firm surface, thereby overcoming the weight of the corner and the restoring force from passive components such as springs and bushings. The precise magnitude of the force request depends on the vehicle. The amount of corner weight removed from one pair of diagonal wheels can be added to the other pair of diagonal wheels to maintain overall stability.

[0087] Lifting / pushing the wheels across the diagonal helps maintain vehicle stability because any change in vehicle attitude (angle) is neither pure roll nor pure pitch.

[0088] In one example, the lifted and pushed wheel maintains a distance from its potential / pre-existing wheel-to-body ratio until a switching / exit condition is met, giving the driver / user the opportunity to dig through the particles beneath the lifted wheel. In some examples, the driver may attempt various techniques to excavate the surface without leaving the vehicle (e.g., by slowly spinning the wheel, moving the steering wheel back and forth). In such examples, lifting and pushing may continue until the switching / exit condition is met, or may continue for a set duration (e.g., no more than 1 minute).

[0089] The force request used to lift and push the wheel can include a steady-state displacement of the distance from the neutral / pre-existing target wheel to the body. Alternatively, the force request can cause the wheel to oscillate vertically (pulsate) while it is slowly spinning. Figure 6C The amplitude (A)-time (t) curve illustrates the oscillation, where amplitude is the displacement of the wheel from the vehicle body (positive = further away from the vehicle body 102). The oscillation of the spinning wheel can help compact loose sand and / or feed the recovery plate under the vehicle. The recovery plate will be placed close to the tangent of the wheel, as close as possible to the bottom of the wheel, and the spinning vertical oscillating wheel can further drag the recovery plate under the wheel. The slow rotation of the wheel prevents sand / mud or other debris from being thrown into the air. Wheel rotation can be automatically triggered without driver-actuated accelerators or can be manually triggered.

[0090] If oscillation is used, then Figure 6A and Figure 6B It can represent different points in time. Figure 6C They exhibit the same oscillation pattern, where the sub-groups of wheels pulsate 180 degrees out of phase at a common frequency. Therefore, at any given time, when one group of wheels is lifted, the other group of wheels is also propelled.

[0091] The oscillations between pushing / lifting the wheels maintain a consistent average ground pressure but shift the weight distribution around vehicle 100. Therefore, vehicle 100 is less likely to get stuck, bottom out, or immediately lose traction that could cause it to move unintentionally.

[0092] In some, but not all, examples, the oscillation pattern will be an approximate sine curve for smoothness, as illustrated. In other examples, the waveform is different or a series of discontinuous pulses. The frequency may include a first predetermined frequency between approximately 0.25 Hz and approximately 3 Hz, and / or a second frequency between approximately 8 Hz and approximately 15 Hz to help compact loose sand. In some examples, the two frequencies are superimposed. In some examples, a frequency sweep is performed.

[0093] Figures 7A to 7E Another mode is shown, in which the wheels are raised sequentially or in an oscillating mode. Each wheel can be raised one at a time, allowing the particulate material to move beneath the wheel before proceeding to the next wheel. The next wheel can be shifted after the previous wheel returns to the distance from its neutral / pre-existing target wheel to the body.

[0094] Lifting individual wheels may include lifting the wheel to create a gap, while simultaneously pushing down at least some of the other three wheels to increase the gap beneath the lifted wheel. In some implementations, at least some of the other three wheels are not pushed down.

[0095] The oscillation mode can include a clockwise or counterclockwise rotational universal joint mode around the vehicle. Figures 7A to 7E It can represent the rotation pattern at four time points, and Figure 7E This represents the amplitude-time curve.

[0096] The first wheel (e.g., FR) pulses at the first phase, wherein the first wheel is located at the first lateral side (right) of the vehicle 100 and at the first longitudinal end (front) of the vehicle 100. Figure 7A The first wheel FR is shown in a raised position (with ground clearance), while the other wheels are not raised.

[0097] The second wheel (e.g., FL) pulses at a second phase following the first phase, wherein the second wheel is located at the second lateral side (left) of the vehicle 100 and at the first longitudinal end (front). Figure 7B The second round of FL is shown to be in an elevated state, while the other rounds are not in an elevated state.

[0098] The third wheel (e.g., RL) pulses at the third phase following the second phase, wherein the third wheel is located at the second lateral side (left) of the vehicle 100 and at the second longitudinal end (rear). Figure 7C The third round of RL is shown to be in an elevated state, while the other rounds are not in an elevated state.

[0099] The fourth wheel (e.g., RR) pulsates at the fourth phase following the third phase, wherein the fourth wheel is located at the first lateral side (right) and at the second longitudinal end (rear). Figure 7D The fourth round (RR) is shown to be in an elevated state, while the other rounds are not in an elevated state.

[0100] like Figure 7E As shown, the first to fourth phases can be approximately 90 degrees apart from each other, and their frequencies can be the same to provide a uniformly rotating variation of ground imprint force around the vehicle.

[0101] The movement of the universal joints around the vehicle helps maintain the stability of the vehicle body, so that the movement of the vehicle body is neither pure roll nor pure pitch.

[0102] Figure 8 This is a flowchart illustrating an example control method 800 for recovery mode implemented by control system 300. In this example, but not necessarily in all examples, recovery mode can be manually activated.

[0103] Method 800 begins at operation 802, which enables recovery mode. Enabling recovery mode may optionally require one or more constraints to be unmet.

[0104] The example constraint is that vehicle 100 is moving. The vehicle speed should be approximately zero to allow for the necessary recovery. The vehicle speed can be measured and determined.

[0105] Another example constraint is that vehicle 100 is not secured to prevent movement. Vehicle 100 may be secured to prevent movement in one or more of the following ways: the transmission selector is in "park" or "neutral"; vehicle 100 is held by requesting braking; the parking brake (electronic brake / handbrake) is engaged. The status of these vehicle securing systems can be checked by control system 300.

[0106] Another example constraint is that the torque request is greater than a threshold (e.g., non-zero or some larger value). Torque should not initially be requested. If vehicle 100 includes a creeping powertrain, control system 300 may require that creeping torque not be received by the wheels (e.g., torque source 103 is not engaged with the wheels). In some examples, control system 300 may disengage torque source 103 and / or may send a braking request to keep vehicle 100 stationary.

[0107] Another example constraint is that at least one door is open, as detected by the door open / close sensor.

[0108] Another example constraint is that one or more occupants (e.g., driver / passenger) are leaving the vehicle 100, as detected by seat weight sensors, seat belt sensors, cabin cameras or other devices.

[0109] At operation 804, the entry condition is met. In a manual implementation, meeting the entry condition includes receiving a user-initiated (e.g., driver-initiated) request to enable method 800. An HMI 520 may be provided to enable the request to be provided to the control system 300.

[0110] If the constraints are met, HMI 520 may be unavailable. In some implementations, the user does not need to be inside vehicle 100. For example, HMI 520 may be presented on the user's portable electronic device (e.g., smartphone / key card / wearable device) to enable remote triggering of method 800. For example, the user may be standing next to the affected wheel.

[0111] If the entry conditions are automatic, parameters such as wheel slippage, vehicle speed, and surface detection sensors (e.g., cameras) can help indicate that the vehicle 100's ability to move forward is impeded.

[0112] When the entry conditions are met, the control system 300 can optionally determine which wheels(s) need to be lifted and which wheels(s) need to be pushed to create a gap under the target wheel. These actions may not be necessary if the wheels are to oscillate as described above.

[0113] In the example, a request initiated by the driver can identify (select) one or more wheels that require clearance. Alternatively, the control system 300 can control wheel selection by automatically determining which wheel needs to be lifted, such as the wheel with the least wheel slip compared to the other wheels.

[0114] In some examples, the control system 300 can control wheel selection by limiting which wheels the driver can choose, for example, sensor information (e.g., tilt from accelerometers 516 / 522) indicating that lifting a particular wheel will result in an excessive change in vehicle attitude.

[0115] On a slope, lifting the left front wheel may create clearance under the right rear wheel due to vehicle pitch. Therefore, the control system 300 can determine the appropriate wheel to be lifted and pushed down based on sensor information (e.g., tilt) to create clearance under the target wheel. The control system 300 can be arranged to determine the slope and direction of any slope the vehicle is on and utilize that slope when selecting which wheel to lift first, thereby allowing the system to achieve maximum advantage with minimal effort.

[0116] At operation 806, the active suspension system 104 is controlled to adjust in the first wheel (e.g., Figure 7A ) or the first set of diagonal wheels ( Figure 6A A gap is created below.

[0117] Optionally, the control system 300 may also reduce the spring stiffness of the spring 504 and / or the actuator 502 of the target wheel to increase the clearance, such that the active spring provides less resistance to be overcome to create the clearance under the wheel.

[0118] Alternatively, the oscillation example described above can be used ( Figures 6A to 7E One example of oscillation is used to make the wheel oscillate vertically. While torque is applied automatically or by the driver, the oscillation can help the vehicle 100 climb out of the surface by further increasing the flow of granular material under the wheel.

[0119] When the wheels are lifted / pushed, the control system 300 can enable a torque request to be sent (automatically or manually) to the torque source 103 in an attempt to restore the vehicle 100 from the surface. Optionally, the control system 300 can continue to require all doors to be closed. If operation from the outside is not permitted, the control system 300 can continue to require the occupants to remain inside the vehicle 100.

[0120] In some examples, the overall driving height of vehicle 100 can also be increased depending on the fulfillment of entry conditions, such as the vehicle being stuck and bottomed out.

[0121] Operation 808 includes the control system 300 sending a torque request to the torque source 103 to cause the lifted wheel to rotate by at least a predetermined smaller rotation less than one full revolution. This is to assist in feeding the recovery plate, etc., under the wheel with increased clearance. This can be done simultaneously with wheel oscillation to aid in feeding the recovery plate under the wheel.

[0122] In the example, a predetermined wheel rotation is manually triggered via the HMI 520 once the user has placed the recovery plate in the starting position. Less than one full rotation of the wheel is typically sufficient to feed a recovery plate less than 2.5 meters in length.

[0123] In an alternative implementation, the user manually performs a smaller rotation using the accelerator pedal or other throttle control device.

[0124] If the wheels are lifted sequentially rather than individually in an oscillating mode, the transition conditions of operation 810 can be checked. This controls the transition from increasing the clearance under one wheel or group of wheels to increasing the clearance under another wheel or group of wheels.

[0125] In some examples, once the user has completed the first round of preparation for recovery (e.g., by inserting the recovery board) and is ready for the second round of recovery, the user initiates a transition condition via HMI 520. The user-initiated request can be confirmation that the user is ready to continue to the next predetermined round, or an explicit user identification of which round needs to be recovered next.

[0126] In the example use case, the user must re-enter the cabin and close the doors before the transition can be completed. This ensures that the currently raised wheels will lower when no further operation is required. An initial alarm can also be presented via HMI 520 when the transition conditions are met to ensure that no other vehicles are in the area surrounding vehicle 100.

[0127] If the conversion condition is automatic, the conversion can be triggered, for example, after the ground clearance has been maintained for a predetermined time in the first round, the value of which is no more than 1 minute.

[0128] In addition to controlling the active suspension system 104 to in the second wheel (e.g., Figure 7B ) or the second set of diagonal wheels ( Figure 6B Aside from the time gap below, operation 812 is similar to operation 806. Operation 812 occurs after the transition condition or as part of an ongoing oscillation pattern.

[0129] Operation 814 is similar to operation 808. Torque source 103 rotates the lifted wheel at least a predetermined rotation to feed the recovery plate. If the different driven wheels have different torque sources (e.g., hub motors or "off-road" hybrid powertrains), then torque source 103 may differ from the torque source of operation 808.

[0130] A control loop is provided after operation 814 and before operation 810 in case any other individual wheel needs to increase its clearance (e.g., Figure 7C Then Figure 7D ).

[0131] At operation 816, the exit condition is met. The exit condition can be a manual, user-initiated termination request. Similar to the transition condition, the user can confirm via HMI 520 that they are ready to continue, and the control system 300 determines that no other wheels need to be lifted.

[0132] If the exit condition is automatic, exit can be triggered after the final wheel's ground clearance has been maintained for a predetermined time. Another example of an automatic exit condition is detecting that the vehicle speed exceeds a threshold, meaning that vehicle 100 is no longer stuck.

[0133] Method 800 terminates when the exit conditions are met. Optionally, an alert may be presented to the user to prompt them to check for any obstacles while moving vehicle 100.

[0134] In some examples, the above method 800 can be interrupted by braking requests exceeding a threshold, signals from the HMI, etc. Therefore, if users wish to interrupt the recovery mode, they can do so quickly and intuitively.

[0135] In some examples, method 800 may break in response to changes or rates of change in vehicle body attitude (roll, pitch, and / or yaw) exceeding a threshold.

[0136] In some examples, method 800 can be interrupted in response to the opening of the door when the wheel is oscillating, rotating, or switching between different lifting / pushing modes.

[0137] In some examples, method 800 can be interrupted based on the detection of a person and / or activity / motion near the wheels of vehicle 100. Detection can be achieved by processing data from object detection sensors, such as visible light cameras, radar, lidar, or ultrasonic sensors.

[0138] Interrupting method 800 may include returning the active suspension system 104 to its pre-existing / neutral target wheel-to-body position, and / or presenting an alarm signal (e.g., honking the horn, flashing lights).

[0139] For the purposes of this disclosure, it is to be understood that the controllers described herein may each include a control unit or computing device having one or more electronic processors. A vehicle and / or its systems may include a single control unit or electronic controller, or alternatively, different functions of the controller may be embodied in or hosted in different control units or controllers. A set of instructions may be provided that, when executed, causes the controller or control unit to implement the control techniques (including the methods described herein). This set of instructions may be embedded in one or more electronic processors, or alternatively, may be provided as software executed by one or more electronic processors. For example, a first controller may be implemented in software running on one or more electronic processors, and one or more other controllers may also be implemented in software running on one or more electronic processors, optionally in software running on the same one or more processors as the first controller. However, it will be understood that other arrangements are also useful, and therefore, this disclosure is not intended to be limited to any particular arrangement. In any case, the aforementioned set of instructions may be embedded in a computer-readable storage medium (e.g., a non-transitory computer-readable storage medium), which may include any mechanism for storing information in a form readable by a machine or electronic processor / computing device, including but not limited to: magnetic storage media (e.g., floppy disks); optical storage media (e.g., CD-ROMs); magneto-optical storage media; read-only memory (ROM); random access memory (RAM); erasable programmable memory (e.g., EPROMs and EEPROMs); flash memory; or electrical media or other types of media for storing such information / instructions.

[0140] It will be understood that various changes and modifications can be made to the invention without departing from the scope of this application.

[0141] Figure 8 The boxes illustrated may represent steps in the method and / or code portions in computer program 308. The description of a specific order of boxes does not necessarily imply a desired or preferred order, and the order and arrangement of boxes may be changed. Furthermore, some steps may be omitted.

[0142] Although embodiments of the invention have been described with reference to various examples in the preceding paragraphs, it should be understood that modifications may be made to the given examples without departing from the scope of the claimed invention. For example, the wheel may be lifted for inspection and maintenance purposes rather than for restoring the vehicle from the particle surface.

[0143] The features described above can be used in combinations other than those explicitly described.

[0144] Although the functions have been described with reference to certain features, these functions may be able to be performed by other features, whether or not other features are described.

[0145] Although features have been described with reference to certain embodiments, these features may also exist in other embodiments, whether or not other embodiments are described.

[0146] While the foregoing description focuses on those features of the invention that are considered particularly important, it should be understood that the applicant reserves the right to claim protection for any patentable features or combinations thereof mentioned above and / or shown in the drawings, whether or not they are specifically emphasized.

Claims

1. A control system for controlling an active suspension system of a vehicle, the control system comprising one or more controllers, wherein, The control system is configured to: Determine that the entry conditions are met; and Based on the satisfaction of the entry condition, a request is sent to the active suspension system to create clearance under the first wheel of the vehicle, but not under the other wheels of the vehicle. The first wheel is located at a first lateral side of the vehicle and at a first longitudinal end of the vehicle, and the plurality of other wheels include at least: a second wheel located at a second lateral side of the vehicle and at the first longitudinal end of the vehicle; and a third wheel located at the first lateral side of the vehicle and at the second longitudinal end of the vehicle. The request is configured to create a gap under the first wheel of the vehicle but not under the second, third, and fourth wheels, wherein the fourth wheel is located at the second lateral side and the second longitudinal end, diagonally opposite the first wheel. The control system is configured to send a second request to the active suspension system to create clearance under the second wheel but not under the first and fourth wheels.

2. The control system according to claim 1, wherein, The request is configured to control the suspension actuators of the first wheel to lift the first wheel.

3. The control system according to claim 1, wherein, The request is configured to create a gap under a pair of diagonally opposite wheels, the pair of diagonally opposite wheels including the first wheel and the fourth wheel of the vehicle, wherein the fourth wheel is located at the second lateral side and at the second longitudinal end, diagonally opposite the first wheel.

4. The control system according to claim 1, wherein, The second request is configured to create a gap beneath a pair of diagonal wheels, the pair of diagonal wheels including the second wheel and the third wheel, or Wherein, the second request is configured to create a gap under the second wheel but not under the first wheel, the third wheel, and the fourth wheel, and wherein the control system is configured to: Send a third request to the active suspension system to create clearance under the third wheel but not under the first, second, and fourth wheels; and A fourth request is sent to the active suspension system to create clearance under the fourth wheel, but not under the first, second, and third wheels.

5. The control system according to any of the preceding claims, wherein, The request includes a force request configured to overcome a restoring force associated with the first wheel to remove a grounding imprint beneath the first wheel.

6. The control system according to any of the preceding claims, wherein the control system is configured to control the active suspension system to reduce the spring stiffness associated with the first wheel when the active suspension system generates the clearance.

7. The control system according to any of the preceding claims, wherein, The fulfillment of the entry condition includes receiving a user-initiated request to create the gap below the first round.

8. The control system according to any of the preceding claims, wherein, The entry condition must be met if it is determined that the vehicle is not moving.

9. The control system according to claim 2, wherein, The request is configured to control the suspension actuators of the plurality of other wheels to increase clearance under the first wheel.

10. The control system according to claim 7, wherein, The user-initiated request is configured to identify the first round as the round selected by the user.

11. A vehicle comprising a control system according to any of the preceding claims.

12. A method for controlling an active suspension system of a vehicle, the method comprising: The entry conditions are confirmed to be met; as well as Based on the satisfaction of the entry condition, a request is sent to the active suspension system to create clearance under the first wheel of the vehicle, but not under the other wheels of the vehicle. The first wheel is located at a first lateral side of the vehicle and at a first longitudinal end of the vehicle, and the plurality of other wheels include at least: a second wheel located at a second lateral side of the vehicle and at the first longitudinal end of the vehicle; and a third wheel located at the first lateral side of the vehicle and at the second longitudinal end of the vehicle. The request is configured to create a gap under the first wheel of the vehicle but not under the second, third, and fourth wheels, wherein the fourth wheel is located at the second lateral side and the second longitudinal end, diagonally opposite the first wheel. The method further includes sending a second request to the active suspension system to create clearance under the second wheel but not under the first and fourth wheels.

13. A computer program product, which, when executed, is configured to perform the method according to claim 12.

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