System and method for an active suspension of a robotic cleaning device

Abstract

A method of controlling a robotic cleaning apparatus. The method includes detecting, via one or more sensors, a soiled area on a target surface for cleaning. The method includes activating an active suspension system to reduce a distance between a chassis of the robotic cleaning device and a target surface to increase pressure exerted by a cleaning pad mounted to the chassis of the robotic cleaning device. The method includes monitoring, via one or more processors, one or more parameters of the robotic cleaning device to determine whether the one or more parameters are outside a threshold parameter range. The method includes adjusting the active suspension system if the one or more parameters are outside the threshold parameter range, and deactivating the active suspension system when it is detected that the soiled area on the target surface is cleaned.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 424,754, filed on November 11, 2022; U.S. Provisional Application No. 63 / 424,740, filed on November 11, 2022; U.S. Provisional Application No. 63 / 532,266, filed on August 11, 2023, and U.S. Provisional Application No. 63 / 532,269, filed on August 11, 2023, the disclosures of which are incorporated herein by reference in their entireties. Technical Field

[0003] The present disclosure relates generally to the field of robotic cleaners, and more particularly, to suspension systems in robotic cleaners. Background Art

[0004] The background description provided herein is for the purpose of generally presenting the context of the present disclosure. The work of the presently named inventors, to the extent it is described in this background section, and aspects of the description that may not have qualified as prior art at the time of filing, are not admitted, either explicitly or implicitly, as prior art to the present disclosure.

[0005] In the field of robotic cleaning devices, various cleaning functions can be implemented to address a range of cleaning needs. For example, some robotic cleaning devices may include functions for vacuum cleaning, wet cleaning, agitation brushes, etc. Robotic cleaners can operate in a variety of environments, which may include varying terrain, floor types, debris, and other obstacles. Because many robotic cleaning devices can operate in autonomous and / or semi-autonomous modes, there is a need for robotic cleaning devices to automatically adjust to maintain functionality in a variety of environments. Summary of the Invention

[0006] The following presents a simplified overview of the present disclosure to provide a basic understanding of some aspects of the present disclosure. This overview is not an extensive overview of the present disclosure. It is not intended to identify key or important elements of the present disclosure or to describe the scope of the present disclosure. The following overview merely presents some concepts of the present disclosure in a simplified form as a preface to the more detailed description provided below.

[0007] In one embodiment, the present disclosure describes a method for controlling a robotic cleaning device. The method may include detecting a dirty area on a target surface for cleaning via one or more sensors. The method may include activating an active suspension system to reduce the distance between the chassis of the robotic cleaning device and the target surface, thereby increasing the pressure applied by the cleaning pad mounted to the chassis of the robotic cleaning device. The method may include monitoring one or more parameters of the robotic cleaning device via one or more processors to determine whether the one or more parameters are outside a threshold parameter range. The method may include adjusting the active suspension system if the one or more parameters are outside the threshold parameter range, and deactivating the active suspension system when it is detected that the dirty area on the target surface is cleaned.

[0008] In another embodiment, the present disclosure describes a method for controlling a robotic cleaning device. The method may include detecting a location where the mobility of the robotic cleaning device is restricted. The method may include determining that a current draw of a drive motor that controls rotation of one or more wheels of the robotic cleaning device is above a predetermined current range. The method may include, based on determining that the current draw of the drive motor is above the predetermined current range, activating an active suspension system to reduce a distance between a chassis of the robotic cleaning device and a target surface.

[0009] In another embodiment, the present disclosure describes a method for controlling a robotic cleaning device. The method may include detecting a location where the robotic cleaning device is restricted in mobility and determining that a current draw of a drive motor that controls rotation of one or more wheels of the robotic cleaning device is below a predetermined current range. The method may include, based on determining that the current draw of the drive motor is below the predetermined current range, activating an active suspension system to increase a distance between a chassis of the robotic cleaning device and a target surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Non-limiting and non-exhaustive embodiments are described with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, but emphasis is placed on illustrating the principles of the present disclosure. In the drawings, unless otherwise specified, like reference numerals refer to like parts throughout the various figures.

[0011] For a better understanding of the present disclosure, reference is made to the following detailed description read in conjunction with the accompanying drawings, in which:

[0012] Figure 1A is a partial cross-sectional side view of an embodiment of a robotic cleaner according to the present disclosure;

[0013] Figure 1B yes Figure 1A A front view of a robotic cleaner;

[0014] Figure 2A yes Figure 1AA top-down perspective view of a robotic cleaner;

[0015] Figure 2B yes Figure 1A An exploded view of the robot cleaner;

[0016] Figure 3A According to the present disclosure Figure 1A A partial cross-sectional view of a robotic cleaner illustrating an embodiment of an active suspension system in a first position;

[0017] Figure 3B yes Figure 1A A partial cross-sectional view of the robot cleaner showing the second position Figure 3A Active suspension system;

[0018] Figure 4A It is in the first position Figure 3A Detailed view of the active suspension system;

[0019] Figure 4B It is in the second position Figure 3B Detailed view of the active suspension system;

[0020] Figure 5 is a side view of another embodiment of an active suspension system according to the present disclosure;

[0021] Figure 6 is a flow chart of an embodiment of a method for controlling an active suspension system of a robotic cleaner according to the present disclosure;

[0022] Figure 7 is a flow chart of another embodiment of a method for controlling an active suspension system of a robotic cleaner according to the present disclosure;

[0023] Figure 8 is a top cross-sectional view of another embodiment of an active suspension system according to the present disclosure;

[0024] Figure 9 is a top cross-sectional view of another embodiment of an active suspension system according to the present disclosure;

[0025] Figure 10 is a top cross-sectional view of another embodiment of an active suspension system according to the present disclosure;

[0026] Figure 11 is a flow chart of another embodiment of a method for controlling an active suspension system of a robotic cleaner according to the present disclosure;

[0027] Figure 12 is a flow chart of another embodiment of a method for controlling an active suspension system of a robotic cleaner according to the present disclosure; and

[0028] Figure 13 is a flow chart of another embodiment of a method for controlling an active suspension system of a robotic cleaner according to the present disclosure.

[0029] It will be understood by those skilled in the art that the elements in the drawings are illustrated for simplicity and clarity, and therefore not all connections and options are shown to avoid obscuring aspects of the present invention. For example, common but well-understood elements that are useful or necessary in commercially viable embodiments are generally not depicted to facilitate a less obstructed view of these various embodiments of the present disclosure. It will also be understood that certain actions and / or steps can be described or depicted in a specific order of occurrence, and those skilled in the art will understand that such specificity regarding order is not actually required. It will also be understood that the terms and expressions used herein will be defined relative to their corresponding respective areas of investigation and research, unless a specific meaning has been otherwise set forth herein. DETAILED DESCRIPTION

[0030] The present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, which form a part of the present disclosure and which illustrate, by way of illustration, specific exemplary embodiments in which the present disclosure may be practiced. However, the present disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art. Among other things, the present invention may be embodied as a method or an apparatus. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Therefore, the following detailed description should not be taken in a limiting sense.

[0031] Throughout the specification and claims, unless the context clearly dictates otherwise, the following terms have the meanings explicitly associated herein. As used herein, the phrase "in one embodiment" does not necessarily refer to the same embodiment, although it may refer to the same embodiment. Furthermore, as used herein, the phrase "in another embodiment" does not necessarily refer to a different embodiment, although it may refer to a different embodiment. Thus, as described below, various embodiments of the present invention may be readily combined without departing from the scope or spirit of the invention.

[0032] Furthermore, as used herein, the term "or" is an inclusive "or" operator and is equivalent to the term "and / or" unless the context clearly dictates otherwise. The term "based on" is not exclusive and allows for being based on additional factors not described unless the context clearly dictates otherwise. Furthermore, throughout this specification, the meanings of "a," "an," and "the" include plural references. The meaning of "in" includes "in" and includes plural references. The meaning of "in" includes "in" and "on."

[0033] In some embodiments, the present disclosure describes an autonomous or semi-autonomous robot that can be configured to vacuum, wet clean, or otherwise clean floors, carpets, and / or other target surfaces in a home or other suitable location. In some embodiments, an autonomous cleaning robot consistent with the present disclosure may include a chassis and a transport drive system configured to transport cleaning elements autonomously or semi-autonomously on a target surface. The robot may be supported on a target surface by a plurality of wheels in rolling contact with the target surface, and the robot may include control and drive elements configured to guide the robot to roughly traverse the target surface in one or more directions. In some embodiments, the robot may include a drive device controlled by a controller and powered by one or more motors for performing autonomous or semi-autonomous movement on a target surface.

[0034] In some embodiments, the cleaning robot may include one or more cleaning modules. In embodiments with multiple cleaning modules, the cleaning modules may operate individually or in coordination. In some embodiments, the cleaning robot may include a dry cleaning module that may be configured to collect dry debris from a target surface and a wet cleaning module that may be configured to perform wet cleaning by applying a liquid (e.g., a cleaning fluid) to a cleaning pad and scrubbing the target surface with the cleaning pad. The surface cleaning robot may also include at least two containers or compartments that may store debris collected by the dry cleaning module and store cleaning fluid that may be used by the wet cleaning module.

[0035] In some embodiments, a cleaning robot may include an active suspension system that can be configured to adjust the robot's ride height. The active suspension system can provide various benefits to the robot's performance, such as increased cleaning power, efficiency, improved mobility, improved range, and improved energy efficiency and / or battery life. For example, in some embodiments, the active suspension system can help optimize the ride height to improve suction / seal with the target surface and / or maintain desired contact with the target surface and the rotation speed of the agitator brush. In some embodiments, the control method may include maintaining a desired, predetermined, or calculated engagement depth or interference distance between a cleaning robot component (e.g., an agitation member, such as a brush) and the target surface. In some embodiments, the control method may include maintaining a substantially constant torque load on a cleaning robot component, such as an agitator motor or brushroll motor. Additionally, the active suspension system can provide improved mobility for the cleaning robot, for example, by improving or optimizing the ride height on target surfaces with different properties and / or providing improved ability to navigate over thresholds, cables, or other environmental obstacles. In some embodiments, the active suspension system can also provide for selectively lifting the cleaning pad (or other robot features) to reduce or prevent interference with the target surface when not needed. For example, in some embodiments, the active suspension system can provide for lifting a soiled cleaning pad off a target surface, such as an area rug or carpet, to reduce or eliminate the transfer of soiled material to the target surface.

[0036] In some embodiments, the active suspension system described herein can provide hard stops to the wheel modules of the robot, which can allow the robot to change the height above the ground on different types of target surfaces. In some embodiments, this can be achieved without changing other features of the robot's suspension system. In other words, ride damping and other suspension effects can still be utilized via other suspension components (e.g., springs, dampers, etc.), but at variable heights. For example, in some embodiments, the active suspension system can provide a tighter seal to certain target surfaces (e.g., bare floors, low-pile carpets, etc.) while still providing the ability to clear obstacles. In some embodiments, the target surface conditions can be determined by one or more sensors that can inform the optimal height above the ground for given conditions and desired cleaning performance.

[0037] Figure 1A and Figure 1Bis an embodiment of a cleaning robot 50 that may include the active suspension system described herein. The cleaning robot 50 may include a generally circular housing or chassis 52, which may have an upper portion 54 and a lower portion 56. In some embodiments, the upper portion 54 may include a user interface that can be used to initiate cleaning or other operations and / or provide an indication of the robot's status (e.g., mode, battery life, errors, etc.). The cleaning robot 50 may include one or more driven wheel assemblies 59A, 59B, which may include drive wheels 58A, 58B. The robot 50 may also include one or more casters 62 coupled to the lower portion 56 of the chassis 52. In some embodiments, the wheels 58A, 58B may rotate independently about an associated axis of rotation and may be coupled to a corresponding drive motor contained within each driven wheel assembly 59A, 59B. Thus, in some embodiments, each wheel 58A, 58B may generally be described as being independently driven. In some embodiments, both wheels 58A, 58B can be driven by a single drive motor that can distribute power to the wheels via one or more drive shafts and / or differentials, or the wheels can be driven by separate motors (e.g., suction motors) with power distribution to various robot components. In some embodiments, the cleaning robot 50 can be autonomously steered or controlled to maneuver on a target surface, for example, by drive signals from one or more controllers on a control board provided on the robot. The drive signal can steer the cleaning robot 50 by, for example, adjusting the rotational speed of one of the multiple wheels 58A, 58B relative to another of the multiple wheels 58A, 58B.

[0038] Each wheel assembly 59A, 59B can include an arm 60A, 60B and wheels 58A, 58B. Each arm 60A, 60B can have a proximal end that is rotatably coupled to the bottom 56 of chassis 52 or the stationary portion of the wheel assembly. Each wheel 58A, 58B can be rotatably coupled to the distal end substantially opposite to the proximal end of each respective arm 60A, 60B. In certain embodiments, each wheel assembly 59A, 59B can include a drive motor that can be coupled to arm 60A, 60B. In certain embodiments, each wheel assembly 59A, 59B can also include one or more gears that can be configured to transmit power from each drive motor to each respective wheel 58A, 58B. In certain embodiments, each proximal end of each respective arm 60A, 60B can rotate around chassis 52 to raise and / or lower each respective wheel 58A, 58B. As described in more detail below, the active suspension system 100 can pivot each proximal end of each respective arm 60A, 60B, lowering each wheel 58A, 58B, and thereby selectively raising and / or lowering the chassis 52 relative to the floor or other target surface.

[0039] In some embodiments, the cleaning robot 50 may further include a vacuum module 64, which may include a suction duct 69, a dust cup, a suction motor, and other components. The suction duct 69 may be arranged on the lower portion 56 of the chassis 52 relative to the floor or other target surface, and may be fluidically coupled to the dust cup and the suction motor. In some embodiments, the suction motor may be configured to allow debris from the target surface to be sucked into the suction duct 69 and deposited into the dust cup for later disposal. The exhaust port may be fluidically coupled to the suction motor. In various embodiments, the exhaust port may be configured to prevent unwanted debris from stirring, guiding debris, or drying cleaning fluid.

[0040] In some embodiments, the robotic cleaner 50 can include a wet cleaning module 65 that can be permanently or removably secured to the chassis 52. The wet cleaning module 65 can include a cleaning fluid tank and a wet cleaning pad 67. In some embodiments, as the cleaning robot 50 can travel over a floor or other target surface, a suction tube 69 connected to a suction motor can collect dry debris from the floor while a liquid applicator of the wet cleaning module 65 can apply cleaning fluid to the wet cleaning pad 67. In some embodiments, the wet cleaning pad 67 can be raised and / or lowered relative to the target surface, for example, by raising or lowering wheels 58A, 58B having an active suspension system as disclosed herein, to clean the target surface with the wet cleaning pad.

[0041] Figure 2A and Figure 2BAn embodiment of a cleaning robot 50 including an active suspension system 100 is shown. The active suspension system 100 can take various forms to raise and / or lower the wheels 58A, 58B relative to the chassis 52 of the cleaning robot 50. In some embodiments, the active suspension system 100 can be controlled by one or more controllers 74, which can be located in the wheel assemblies 59A, 59B or elsewhere in the cleaning robot 50. In some embodiments, the controller can be a proportional-integral-derivative (PID) controller or another suitable control device. In some embodiments, the controller 74 (e.g., a PID controller) can be partially or entirely software-based and may not require a separate controller device connected to the active suspension system. In some embodiments, the active suspension system 100 can include a closed-loop controller without any direct feedback. For example, such a controller can control the limits of wheel travel (e.g., up or down) without actually directly measuring wheel position. In some embodiments, the controller (e.g., PID) input can be an indirect measurement, such as brush roller current or cliff sensor data. The controller can electronically communicate with one or more sensors 53 on the cleaning robot 50, which can provide information about the cleaning robot's environment, location, obstacles, and / or properties of the floor or other target surface. In some embodiments, those sensors 53 may include proximity sensors, optical sensors, sonar, LIDAR, infrared (IR) sensors, ultrasonic sensors, 2D and / or 3D cameras, photoelectric sensors, and the like. In some embodiments, one or more laser beams emitted from a laser on the robot 50 can continuously or periodically scan the robot's surroundings, and any returning reflections (visible or otherwise) can be detected by a camera on the robot. Using multiple laser beams over time, the camera's detection of laser returns can be constructed into a point cloud of laser returns from obstacles or other environmental features. The point cloud can be analyzed to determine characteristics of the detected objects, such as physical dimensions (e.g., height), which can be used to determine the desired positioning of the active suspension system 100.

[0042] In some embodiments, the operation of other components of the cleaning robot 50 that are in electronic communication with the controller can provide additional information about the robot's environment, obstacles, floor conditions, or performance. In some embodiments, the controller can use such inputs to determine the appropriate response action of the active suspension system 100. For example, the controller can determine the characteristics of the surrounding environment of the cleaning robot 50 by monitoring the current, voltage, and / or power usage of the agitator or brush roller in the vacuum module 64 over time. Based on the current consumption of the brush roller, the controller 74 can determine whether the brush roller may encounter too much or too little resistance and raise / lower the wheels accordingly. In another example, the controller 74 can use the current or other power usage information from the suction motor to determine whether to raise / lower the wheels via the active suspension system to optimize the vacuum's sealing and / or suction performance. Those skilled in the art will recognize that other inputs may also be used or considered when determining and positioning the wheel height and corresponding chassis clearance of the cleaning robot to most effectively perform cleaning tasks or other activities.

[0043] Cam system

[0044] Figure 2 to Figure 5 An embodiment of an active suspension system 100 for a cleaning robot 50 is shown, wherein each wheel assembly 59A, 59B may include a rotatable cam 102 configured to be selectively driven by a cam motor 104 to raise / lower the wheels 58A, 58B relative to the chassis 52 of the cleaning robot 50. In some embodiments, each wheel assembly 59 may include a passive suspension system that may include a spring 71 coupled to a shock absorber. When the wheel 58 encounters debris or an uneven surface, the spring 71 may inhibit movement of the chassis 52. In some embodiments, the cam 102 of the active suspension system 100 may rotate between two or more positions to provide a movable hard stop, which may allow the cleaning robot 50 to change the height at which the chassis 52 rides without changing the other basic functions of the passive suspension system of the cleaning robot.

[0045] Figure 3A and Figure 3B 1 and 2 illustrate an embodiment of how the active suspension system 100 may be part of or may interact with the wheel assembly 59A and / or a passive suspension system. Figure 4A and Figure 4B A more detailed depiction of the active suspension system is shown. For ease of explanation, Figures 3 to Figure 5The description herein relates to wheel assembly 59, which may refer to any one of wheel assemblies 59A, 59B, etc., and their corresponding components. In some embodiments, each wheel assembly 59 may include an arm 60 having a proximal end 61 and a distal end 63. Proximal end 61 of arm 60 may be pivotally coupled to chassis 52 via a pivot joint 70, and distal end 63 may be rotatably coupled to wheel 58 via a wheel axle 72. In some embodiments, wheel 58 and axle 72 may be driven by one or more drive motors via a gear train 57, which may be disposed on or within arm 60.

[0046] As described above, in some embodiments, the active suspension system 100 can selectively enable the hard stops of the wheels 58 to Figure 3A and Figure 4A The first position shown in Figure 3B and Figure 4B . It is contemplated that in some embodiments, the active suspension system 100 can move between the first position and the second position and can also hold the wheel in virtually any position between the first position and the second position. Movement of the active suspension system 100 between the first position and the second position can increase and / or decrease the clearance height between the floor and the chassis 52. For example, when the active suspension system 100 is in the first position ( Figure 3A and Figure 4A ), the chassis 52 may have a first gap height 68A, and when the active suspension system is in the second position ( Figure 3B and Figure 4B ), the chassis 52 may have a second gap height 68B, which may be greater than the first gap height. Figure 4A As shown, the active suspension system 100 can be switched between a first position and a second position due to the rotation of the cam 102. For example, Figure 4A The cam 102 is shown in a first rotational position which may correspond to the first position, and Figure 4B The cam is shown in a second rotational position, which may correspond to the second position.

[0047] The active suspension system 100 may include a cam motor 104 that may be configured to selectively rotate the cam 102 between at least a first rotational position (eg, Figure 4A ) and a second rotational position (e.g., Figure 4B) rotates between. In some embodiments, one or more cam motors 104 can be provided on the cleaning robot 50, for example, within the wheel assembly 59 or elsewhere. In some embodiments, the cam motor 104 can be mounted to the chassis 52 so as to resist rotation or other movement in response to a rotational force applied to the cam 102. In some embodiments, the cam motor 104 can be a stepper motor that can divide its motor rotation into a plurality of steps, which can be equal steps. In some embodiments, the rotational position of such a stepper motor can be rotated and maintained at a specific known position without the need for additional position sensor feedback to determine the position of the cam 102. In some embodiments, other types of motors consistent with the present disclosure can be used.

[0048] In some embodiments, the rotational force generated by one or more cam motors 104 can be transferred to the cam 102 via a camshaft 106. In some embodiments, the camshaft 106 can pass through a portion of the chassis 52 and / or a camshaft ring 108. In some embodiments, the camshaft ring 108 can apply a clamping force to the chassis 52, thereby holding the cam 102 and the cam motor 104 stationary relative to the chassis 52. In some embodiments, the camshaft 106 can be received in a shaft hole 107 formed in the cam 102. The shaft hole 107 can be offset from the center of the cam 102 so as to define a varying radial distance between the camshaft 106 and the curved circumferential edge 109 of the cam. The varying radial distance can be used to provide variable chassis height adjustment via the active suspension system 100.

[0049] The active suspension system 100 may also include a cam follower 110, which may be mounted or otherwise coupled to the arm 60 of the wheel assembly 59. In some embodiments, the cam follower 110 may be mounted on the top 66 of the arm 60 such that a contact surface 111 of the cam follower may slidably contact the circumferential edge 109 of the cam 102. In some embodiments, the top 66 of the arm 60 may function as the cam follower 110 and the contact surface 111 without a cam mounted thereon. In some embodiments, the arm 60 and cam follower 110 may be biased against the cam 102 by a spring or other mechanism, or the weight of the chassis 52 connected to the cam may bias the cam toward the contact surface 111. Thus, in some embodiments, as the cam 102 rotates about the camshaft 106, the circumferential edge 109 of the cam may slide along the contact surface 111 of the cam follower 110. In some embodiments, the cam 102 can push against the cam follower 110 when the cam rotates in the first rotational direction 114 due to the change in the radial distance between the cam shaft 106 and the cam edge 109. Figure 4A1 is indicated as counterclockwise, but one skilled in the art will appreciate that different configurations of the cam 102 and active suspension system 100 may use different directions of rotation with similar results within the scope of the present disclosure.

[0050] In some embodiments, the cam distance 112 may increase as the cam 102 rotates in the first rotational direction 114 relative to the chassis 52 . In some embodiments, the cam distance 112 may be defined as the radial distance between the cam shaft 106 and the contact surface 111 of the cam follower 110 . Figure 4A A non-limiting example of a first rotational position of the cam 102 resulting in a first cam distance 112A is shown. Figure 4B A non-limiting example of a second rotational position of the cam 102 resulting in a second cam distance 112B is shown. In some embodiments, the cam 102 is positioned in the first rotational position ( Figure 4A ) and the second rotation position ( Figure 4B ) may result in the arm 60 being in a first position ( ) of the active suspension system 100 corresponding to the first cam distance 112A and the first gap height 68A. Figure 3A ) and a second position corresponding to the second cam distance 112B and the second gap height 68B ( Figure 3B ) to move between them.

[0051] Those skilled in the art will recognize that the first and second rotational positions and the resulting first and second gap heights are merely exemplary and that a virtually unlimited number of rotational positions and corresponding cam distances and corresponding gap heights may be achieved using the principles of the present disclosure. Additionally, it is contemplated that the illustrated shape of the cam 102 and cam follower 110 shown in Figures 3-4 is merely one example of a cam shape and that numerous other cam shapes may be used consistent with the scope of the present disclosure. For example, Figure 5 An embodiment of an active suspension system 200 is shown that can include a cam follower 210 having a different shape than the cam follower 110, which can result in providing a different range of potential clearance heights 68C between the floor and the chassis 52. The active suspension system 200 can include a cam motor 204 that can selectively rotate the cam 202 by applying torque to a camshaft 206, which can be disposed through a shaft hole 207 in the cam 202. The cam follower 210 can have a larger vertical dimension than the cam follower 110, which can provide a varying clearance height.

[0052] In some embodiments, one or more controllers (e.g., Figure 2AThe controller 74 (shown) can electronically communicate with each cam motor 104 to provide instructions for changing the ride height of the cleaning robot 50 using the active suspension system 100. In some embodiments, the controller 74 can determine the desired ride height 68 in response to sensory input from the cleaning robot 50's sensors 53 regarding the robot's environment or characteristics of other robot components (e.g., current consumption, rotation rate, etc.). For example, a 3D camera or other sensor can identify obstacles on a target surface that the cleaning robot 50 may be cleaning or otherwise traveling over. The 3D camera can send visual data related to the obstacle to the controller 74 (e.g., laser point cloud formation, etc.), and the controller can decipher the visual data to determine the characteristics of the obstacle, such as its height relative to the floor or other target surface. Based on the determined obstacle height, the controller 74 can determine the desired ride height 68 that will allow the robot 50 chassis 52 to clear the obstacle. In some embodiments, based on predetermined data (e.g., a reference table) from the active suspension system 100, the controller can then determine the degree to which rotation of the cam 102 will result in the desired ride height (if any). In other embodiments, the controller 74 may use other logic to calculate the clearance height, such as adding a predetermined clearance distance to the determined height of the obstacle. In response, the controller may transmit instructions to additionally cause the active suspension system 100 (e.g., the cam motor 104) to apply the determined cam rotation, thereby rotating the cam 102 to a rotational position that results in the desired clearance height. In some embodiments, this process may be iteratively repeated as additional obstacles are encountered and / or the robot 50 moves through its environment.

[0053] Active suspension system control

[0054] Figure 61 is a flow chart of an embodiment of a method 300 for adjusting the height above ground of a cleaning robot 50 based on sensed information about the robot's surroundings as environmental data. At 302, the robot's sensors may monitor the robot's surroundings or environment and transmit the environmental data to one or more controllers, such as the controller 74. At 304, the controllers may receive the environmental data from the sensors and analyze the data to determine whether any obstacles or other environmental objects have been sensed or otherwise discovered near the robot, within the robot's planned travel path, on a target surface for cleaning, or the like. At 306, if no objects are detected, the sensors may continue monitoring the environment as at 302. If an object is detected at 306, at 308, the controller may determine one or more physical characteristics and / or dimensions of the detected object, such as height, width, depth, etc., based on the environmental data. At 310, based on the determined physical dimensions (e.g., height) of the detected object, the controller may determine a desired chassis clearance height, such as by adding a predetermined bumper height to the detected object height or other suitable method or logic.

[0055] At 312, the controller may determine whether the desired undercarriage clearance height is less than a maximum clearance height, which may be specific to the physical capabilities and / or characteristics of the cleaning robot and active suspension system. If the desired undercarriage clearance height is greater than the maximum clearance height, then at 314, the controller may determine whether the robot should avoid the detected object or take other alternative actions. If the desired undercarriage clearance height is less than the maximum clearance height, then at 316, the controller may determine what cam motor output may be used to achieve the desired undercarriage clearance height. For example, in embodiments where the cam motor 104 may be a stepper motor, the controller may determine how many steps the motor should rotate to achieve a cam rotation appropriate to achieve the desired undercarriage clearance height. In other embodiments, the active suspension system 100 may include a rotary encoder to provide feedback on how many rotations (e.g., degrees, radians, etc.) the cam motor may have rotated the camshaft, and the controller may determine how many degrees of rotation may be appropriate to achieve the desired undercarriage clearance height. In some embodiments, information for converting the desired undercarriage clearance height into appropriate measurements of motor input / output may be stored in a lookup table or other database accessible to the controller. In some embodiments, the robot sensors can determine the clearance height in real time or substantially real time and feed this information back to the controller for the controller to determine whether the desired chassis clearance height has been achieved. At 318, the controller can send instructions to the cam motor and, at 320, activate the cam motor to rotate the cam to the appropriate rotation angle determined to achieve the desired chassis clearance height. In some embodiments, the cam motor can continue to rotate the cam until the desired clearance height, as sensed by the robot sensors and determined by the controller, is achieved.

[0056] In some embodiments, one or more controllers may receive feedback from other components of the cleaning robot and use that feedback as input for raising and / or lowering the chassis 52 using the active suspension system 100 . Figure 7 is a flow chart illustrating an embodiment of a method 400 for raising / lowering the active suspension system 100 to maintain one or more predetermined cleaning robot performance metrics (e.g., suction level, brush rotation rate, etc.). In some embodiments, this adjustment can provide improved cleaning performance, power efficiency, battery life, etc. In some embodiments, a controller (e.g., controller 74) can electronically communicate with components of the cleaning robot 50 (e.g., suction motor, vacuum sensor, agitator brushroll, etc.). At 402, method 400 can include monitoring performance metrics of one or more components of the cleaning robot 50. For example, the cleaning robot can monitor the brushroll speed of an agitator brush included in a vacuum module, current or power consumption of the brushroll or other components, vacuum sealing and / or suction, etc. In some embodiments, vacuum sealing or suction can be monitored by one or more pressure sensors disposed in the vacuum module in fluid communication with the suction duct. A relatively low pressure sensed by the one or more pressure sensors can correspond to relatively high suction and / or a better seal with the target surface, and vice versa. Thus, monitoring robot component performance metrics may include monitoring various component activities by a controller in electronic communication with those components or sensors measuring performance of those components.

[0057] At 404, the method may include comparing the measured component performance metric to a target performance parameter for the specific component or measurement. For example, the system may store or determine an optimal brushroll rotation rate or range, which may vary based on the characteristics of the target surface, as determined by a sensor (e.g., bare floor, low-pile carpet, high-pile carpet, etc.). In some embodiments, the system may store data or information related to the optimal current or power consumption of a brush motor that can drive the brushroll rotation. In some embodiments, excessive current consumption may be caused by obstructions or high resistance characteristics of the target surface (e.g., high-pile carpet), and it may be desirable to reduce the friction or resistance level encountered by the brushroll by increasing the chassis clearance height, thereby reducing the current consumed by the brush motor to save power and / or help prevent damage to the brush motor or other components. In another example, the system may store or determine an optimal suction level or range of levels, which may vary based on the characteristics of the target surface. In some embodiments, the system may also store an optimal current consumption or range of current consumption for the suction motor and vary the chassis clearance height to save power and / or help prevent damage to the motor. In some embodiments, the robot can continuously or periodically monitor performance parameters while traversing a first surface type (e.g., bare floor). When the robot detects that it has transitioned to a second surface type different from the first (e.g., carpet), the robot can adjust the robot's chassis clearance height to match the performance parameters to their values ​​from the previous floor type or to target performance parameters for the second surface type by detecting a sudden change in the monitored performance parameters or by using one or more sensors configured to detect the type of surface the robot is traversing (e.g., ultrasonic floor type sensors, proximity sensors, optical sensors, sonar, LIDAR, infrared (IR) sensors, ultrasonic sensors, 2D and / or 3D cameras, photoelectric sensors, etc.). In some embodiments, this control method can help mitigate changes in brushroll baseline current over time due to wear of parts, accumulation of debris around the brushes, and / or other robot conditions.

[0058] At 406 , if the measured performance metric falls within the target parameters or within a predetermined error margin, method 400 may include continuing to monitor the mechanical component performance metric. In some embodiments, if it is determined that one or more performance metrics fall outside of the target parameters or parameter ranges, method 400 may include determining, at 408 , whether the off-target metric is a competing metric. In some embodiments, a competing metric may be a performance metric for which an action that brings one of the competing performance metrics within the target parameters may cause another competing performance metric to move further away from its target parameters. For example, in some embodiments, the controller may determine that the brushroll rotation rate may be below the target parameters, which may indicate that the controller should instruct the active suspension system 100 to raise the chassis clearance height (and therefore raise the brushroll) to reduce the drag encountered by the brushroll and increase the brushroll rotation rate. Simultaneously, the controller may determine that the suction level may be below its target parameters, which may indicate that the controller should instruct the active suspension system 100 to lower the chassis clearance height to improve the vacuum seal and increase the suction level. Because remedial action to improve one performance metric (e.g., raising or lowering the chassis clearance height) may worsen another performance metric, these performance metrics may be considered competing metrics. If no competing metrics exist at 408, the controller may instruct the active suspension system 100 to raise / lower the wheels to adjust the ride height based on the performance metrics at 412. For example, if it is determined that the current draw of the brushroll motor is above its corresponding target parameter, the controller may instruct the active suspension system to raise the ride height, thereby reducing the drag encountered by the brushroll and reducing the current draw of the brushroll motor.

[0059] If competing metrics exist at 408, then at 410, in some embodiments, the controller may weigh the competing metrics to determine which, if any, off-target parameters should be addressed. In some embodiments, the weightings of different component performance metrics may be predetermined for any given scenario. For example, in some embodiments, maintaining target current draw for the brushroll motor may be more heavily weighted (i.e., more important) than maintaining optimal vacuum suction (or vice versa). In some embodiments, the weighting of different performance metrics may vary contextually based on various factors, such as remaining battery life, programming mode, flooring characteristics, user preferences, load levels over time, duration of the off-target metric, etc. Once the controller has determined the more heavily weighted performance metric for a given situation, the controller may instruct the active suspension system 100 to raise / lower the wheels to adjust the chassis clearance height based on the performance metric at 412. In some embodiments, when the controller identifies competing performance metrics, in addition to selecting only one performance metric over another, the robot may also initiate an alternative option. For example, if, as in the example above, the controller determines that the brushroll rotation rate may be below target parameters and the suction level may be below its target parameters, the controller may determine that the chassis height should be lowered to increase suction, but the brushroll rotation should be stopped in order to save battery life or reduce wear on the brushroll. Those skilled in the art will recognize that method 400 can be performed in a continuous manner or iteratively at predetermined intervals so that the active suspension system can make near-constant adjustments in an effort to optimize the performance and / or efficiency of the cleaning robot.

[0060] Other active suspension system configurations

[0061] While the embodiment of the active suspension system 100 shown and described with reference to Figures 2-4 is described as including one or more rotatable cams, each driven by a cam motor, other embodiments are contemplated herein to achieve the goal of adjusting the chassis clearance height of the cleaning robot 50 and / or setting hard stops that represent the limits of travel of the suspension system. In each of the embodiments of the active suspension system disclosed herein, it is contemplated that a similar feedback / control relationship can exist between the robot sensors, one or more controllers, and the active suspension system, regardless of the specific components that make up each specific embodiment of the active suspension system.

[0062] Figure 8An embodiment of an active suspension system 500 is shown that can include a single cam motor 504. In such an embodiment, the cam motor 504 can be mounted to the chassis 52 and can be configured to selectively rotate a camshaft 506, which can be coupled to a plurality of cams 502A, 502B. For example, in some embodiments, a first cam 502A can be disposed on a first end of the camshaft 506 and configured to actuate a wheel assembly 59A, and a second cam 502B can be disposed on a second end of the camshaft and configured to actuate a wheel assembly 59B. In some embodiments, the camshaft 506 can include multiple segments that can transmit rotational torque to each other via one or more gears or gear trains.

[0063] Figure 9 An embodiment of an active suspension system 600 is shown that can divert power from one or more drive motors 78 to power the rotation of one or more cams 602. For example, in some embodiments, a clutch 604 can be configured to selectively utilize the power or rotational torque generated by the drive motor 78, which can also be configured to drive the wheels of the cleaning robot 50. The clutch 604 can be disengaged from the camshaft 606 when cam rotation is not required, and can be reengaged with the camshaft when the controller determines that the active suspension system is required to adjust the chassis clearance height. Figure 10 Another embodiment of an active suspension system 700 is shown that can divert power from multiple drive motors 78 to power the rotation of one or more cams 702. Such a system 700 can include multiple clutches 704 that can divert power from multiple drive motors 78. Each clutch 704 can be configured to selectively utilize the power or rotational torque generated by the drive motor 78, which can also be configured to drive the wheels of the cleaning robot 50. When cam rotation is not required, each clutch 704 can be disengaged from the corresponding camshaft 706, and when the controller determines that the active suspension system is required to adjust the chassis clearance height, each clutch 704 can be reengaged with the corresponding camshaft.

[0064] The cleaning robot 50 may alternatively or additionally include other embodiments of active suspension systems that can be used consistent with the present disclosure. For example, in some embodiments, the robot 50 may include a magnetorheological damper system included on one or more cams. The damper can be filled with a magnetorheological fluid, which can be a mixture of easily magnetized iron particles in a synthetic hydrocarbon oil. In some embodiments, one or more damper tubes can be included on each cam. Each single-tube damper can include a piston containing two electromagnetic coils and two small fluid channels passing through the piston. The electromagnet can be configured to generate a variable magnetic field in the fluid channel. When the magnet is off, the fluid can travel freely through the channel. When the magnet is on, the iron particles in the fluid can create a fibrous structure through the channel in the same direction as the magnetic field. The bond strength between the magnetized iron particles can increase the effective viscosity of the fluid, resulting in a stiffer suspension in the wheel assembly. In some embodiments, the stiffer suspension can create a hard stop for the robot's passive suspension system. In some embodiments, varying the intensity of the current can result in a transient change in the force of the piston. If the sensors detect any body roll or surface changes, they transmit this information to the electrical control unit (ECU), which can compensate by changing the current flowing to the appropriate dampers.

[0065] In some embodiments, instead of or in addition to the cam systems described herein, an active suspension system may use a rack and pinion system to move the wheels toward and / or away from the chassis, thereby raising and / or lowering the chassis relative to a target surface. The rack and pinion may include a rotating gear configured to be rotated by one or more motors, and may include a pinion disposed on an arm of the wheel assembly to transmit the rotational input of the motor to the linear vertical motion of the arm and / or corresponding wheel.

[0066] In some embodiments, a linear actuator can be used instead of or in addition to the cam system described herein. In such a system, a motor for the linear actuator can be mounted to the chassis of the robotic cleaner, and an actuatable arm can contact the arm of the wheel assembly. Linear actuation can move the arm and / or wheel away from the chassis, thereby moving the chassis further away from the target surface. In some embodiments, any combination of the actuators described herein can be used in series or according to a given environmental scenario or other situation.

[0067] In some embodiments, one or more casters (such as casters) can also be adjusted vertically via a cam system, a rack and pinion system, a screw jack, or another suitable lifting / lowering mechanism. In some embodiments, the casters can be configured to be raised and / or lowered in conjunction with the driven wheels in the wheel assembly via a drive train and / or gear train that transmits the rotational torque supplied by the cam motor to a similar cam system corresponding to the casters. In some embodiments, independent cam motors, linear actuators, or other motors can be provided on the chassis to vertically adjust the casters in a manner similar to that described herein with respect to the driven wheels. In some embodiments, any combination of the actuators described herein can be used in series or according to a given environmental scenario or other situation.

[0068] Active suspension increases drag pressure

[0069] In some embodiments, the active suspension system can be used to adjust the mopping pressure applied by the cleaning robot 50 in one or more scenarios. For example, in some embodiments, the cleaning robot 50 can include a mopping mode or a wet cleaning mode, in which a cleaning pad (such as from a Figure 1A A cleaning pad 67 is provided to scrub the target surface with a liquid cleaning agent. In some embodiments, the liquid cleaning agent can be applied to the cleaning pad using a liquid applicator, or can be applied directly to the target surface using, for example, a sprayer or other liquid application mechanism. In some embodiments, the liquid cleaning agent can saturate the cleaning pad after being applied from an application point on the top of the cleaning pad.

[0070] In some embodiments, when the cleaning robot 50 is in mopping mode, the active suspension system 100 can reverse the suspension to increase downward pressure from the cleaning pad 67 to the target surface, either by manual selection by the user or by other automated processes. The increased downward pressure applied by the cleaning pad 67 can increase friction between the cleaning pad and the target surface, and thus can increase cleaning effectiveness. In some embodiments, the downward pressure applied by the cleaning pad 67 can be increased by reducing the gap height (e.g., between the bottom of the wheel 58 and the lower surface on the lower portion 56 of the chassis 52 of the cleaning robot 50) between the wheels 58 and the lower surface of the chassis 52. Figures 4A to 4B In other words, when in mopping mode, the active suspension system 100 can retract the wheels 58A, 58B so that a smaller proportion of the cleaning robot's total weight can be supported by the wheels, and a relatively larger proportion of the cleaning robot's total weight can be supported by the cleaning pad 67 itself. This shift in weight distribution can increase friction between the cleaning pad 67 and the target surface, which can increase the cleaning effectiveness of the cleaning pad.

[0071] In some embodiments, the cleaning robot 50 can automatically increase the pressure of the cleaning pad 67 (either manually or through an automated process) when mopping mode is activated. In some embodiments, the cleaning robot 50 can increase the pressure of the cleaning pad 67 based on environmental factors sensed by one or more sensors of the cleaning robot (e.g., sensor 53). For example, in some embodiments, a pressure sensor can determine whether the pressure applied by the cleaning pad 67 to the target surface meets a predetermined or dynamic value of pressure that may be effective for mopping. In some such embodiments, the pressure sensor can be positioned on the cleaning robot 50 between the cleaning pad 67 and the chassis 52 of the cleaning robot. As the cleaning pad presses against the target surface and, in turn, presses upward against the chassis of the cleaning robot, the pressure sensor can experience varying pressure readings. If the pressure read by the pressure sensor and received by a controller (such as controller 74) is less than a predetermined optimal pressure for a particular mode (such as mopping mode), the active suspension system 100 can retract the wheels 58A, 58B to increase the pressure. Conversely, if the controller 74 determines that the pressure read by the pressure sensor is greater than a predetermined optimal value, the active suspension system 100 can extend the wheels 58A, 58B to reduce the pressure between the target surface and the cleaning pad 67. In some embodiments, a similar process can be implemented by detecting the level of slip between the cleaning pad 67 and the target surface. In such embodiments, if it can be determined that the slip is above the optimal slip value, the controller 74 can instruct the active suspension system 100 to retract the wheels 58A, 58B, which can increase the friction between the cleaning pad 67 and the target surface, thereby reducing slip. Similarly, if the controller 74 determines that the detected slip value may be less than the optimal value, the controller can instruct the active suspension system 100 to extend the wheels 58A, 58B to reduce the friction between the cleaning pad 67 and the target surface, thereby reducing friction and potentially increasing slip.

[0072] In some embodiments, other sensors, such as optical sensors or cameras, can detect particularly soiled areas on the target surface that could benefit from increased pressure and agitation from the cleaning pad 67. For example, in some embodiments, the camera may see a portion of the floor with a particular discoloration or texture (e.g., dirt, food stains, etc.), and the controller 74 may interpret the image as a soiled portion of the target surface. In such an embodiment, the active suspension system 100 can retract the wheels 58A, 58B toward the chassis 52 of the cleaning robot 50 to increase the pressure applied by the cleaning pad 67 at or near the soiled portion of the target surface. When the camera or other sensor 53 determines that the soiled area has been sufficiently cleaned and / or the camera or sensor no longer detects the soiled area, the controller 74 can instruct the active suspension system 100 to extend the wheels 58A, 58B away from the chassis 52, thereby reducing the pressure applied by the cleaning pad 67 to the floor.

[0073] In some embodiments, a humidity sensor can sense the humidity level in the cleaning pad 67 and can adjust the wheel height and clearance accordingly. For example, in some embodiments, when the humidity level sensed by the humidity sensor and determined by the controller 74 may exceed a predetermined threshold humidity level, the controller can instruct the active suspension system 100 to extend the wheels 58A, 58B and provide additional clearance due to the increased thickness of the cleaning pad 67.

[0074] Figure 11 A flow chart illustrates an embodiment of a method 800 for increasing mopping pressure using an active suspension system in various operating modes for various reasons. At 802, a sensor on a cleaning robot (e.g., sensor 53) may identify, and a controller (e.g., controller 74) may determine, that an area of ​​a target surface may be particularly dirty. In some embodiments, detection of a dirty area may automatically initiate mopping mode at 804. Alternatively, in some embodiments, mopping mode may be initiated manually, on a schedule, or for other reasons. At 806, in response to mopping mode being activated or a dirty area being detected, the active suspension system 100 may retract the wheels 58A, 58B of the cleaning robot 50 to increase pressure between the cleaning pad 67 and the target surface, as described above. In some embodiments, the increased pressure of the cleaning pad 67 may apply additional cleaning force to the dirty area due to the increased friction between the cleaning pad and the target surface. At 808, the controller 74 may determine, based on input from the sensors or by other suitable methods, whether certain predetermined parameters are within a desired or optimal range. For example, a pressure sensor may detect pressure applied to the target surface to determine whether the sensed pressure is above or below a threshold pressure level. If the parameter detected at 808 may not be within the optimal range, the active suspension system 100 may adjust the suspension and / or wheel height in a direction that may bring the detected parameter closer to or into the preferred optimal range at 810. For example, if the sensed pressure may be below a preferred threshold pressure level, the active suspension system 100 may retract the wheels 58A, 58B to increase the downward force applied to the cleaning pad 67, thereby increasing the cleaning pad pressure.

[0075] If the parameters detected at 808 are within the preferred range, at 812, the cleaning robot 50 may determine, for example, using sensors, whether the dirty area has been sufficiently cleaned. If not, the method may include continuing to monitor the cleaning parameters at 808 until it can be determined that the dirty area is clean. If so, in some embodiments, the cleaning robot 50 may terminate mopping mode at 814, or at 816, the active suspension system 100 may extend the wheels 58A, 58B to reduce the cleaning pad pressure applied to the target area. In some embodiments, terminating mopping mode itself may cause the active suspension system 100 to extend the wheels 58A, 58B to reduce the cleaning pad pressure. In other embodiments, mopping mode may continue, and the pressure may be increased when the cleaning robot 50 detects other dirty areas that may benefit from increased mopping pressure. In some embodiments, detection of a dirty area or initiation of mopping mode may trigger other actions of the robot 50, such as, for example, dispensing cleaning fluid onto the target surface or the cleaning pad 67.

[0076] Active suspension supporting robotic mobility

[0077] In some embodiments, the active suspension system 100 can help free up the cleaning robot 50 in scenarios where its movement may be restricted or otherwise prevented from moving normally. For example, in some cases, the cleaning robot 50 or a portion of the cleaning robot may be restricted from moving, such as between a piece of furniture and a floor or other target surface, which may prevent or limit the cleaning robot from moving across the target surface to clean. In some such embodiments, the upper portion 54 of the cleaning robot 50 may abut a piece of furniture that is pressing down to generate sufficient pressure on the wheels 58A, 58B such that the wheels may be unable to overcome the friction between the chassis 52 of the cleaning robot 50 and the furniture. In other cases, a portion of the cleaning robot 50 may become located on top of elevated furniture, such as a lamp stand, a pet food bowl, a table or chair leg, etc., which may limit the robot's mobility. In this case, one or more of the wheels 58A, 58B may be suspended above the target surface so that the wheels do not provide any driving power to move the cleaning robot 50.

[0078] In some embodiments, the cleaning robot 50, for example, via the controller 74 and one or more sensors, such as sensor 53, can detect that the robot's movement may be restricted and can use the active suspension system 100 to free the cleaning robot 50 for movement. For example, a tilt sensor or other sensor that can detect the tilt angle of the cleaning robot 50 can determine that it may exceed the angle at which one or more wheels 58A, 58B may contact the target surface, or the angle of the chassis 52 itself. It can also be detected that one or more wheels 58A, 58B may rotate with little or no resistance compared to the resistance encountered during travel, or that the pressure encountered by the wheel or suspension system has decreased, so that it can be determined that the wheel has left the floor, or at least that the friction between the floor and the wheel has decreased sufficiently to minimize traction. In some embodiments, wheel resistance can be determined by monitoring the current level of one or more drive motors 78. For example, when the current level of one or more drive motors 78 drops below a threshold current level, it can indicate that the wheels 58A, 58B may be slipping on the target surface or may be completely off the surface.

[0079] In this case, the controller 74 can instruct the active suspension system 100 to extend one or both wheels 58A, 58B in a direction away from the main body of the cleaning robot 50 and toward the floor, thereby effectively increasing the clearance height of the cleaning robot (e.g., 68A, 68B). Extending the wheels 58A, 58B downward can allow the wheels to contact the floor or other surface and can allow them to regain traction. In addition, increasing the chassis clearance can provide the necessary clearance for the chassis 52 to clear previously suspended obstacles and allow the cleaning robot 50 to travel and clear them. In some embodiments, the active suspension system 100 may only extend the clearance of one wheel 58A, 58B, for example, a wheel that has been determined to be slipping or has lost contact with the floor. In some embodiments, the clearance of both wheels 58A, B can be increased to provide additional chassis clearance for the chassis 52 of the cleaning robot 50.

[0080] In embodiments where the cleaning robot 50 detects that its movement may be restricted due to being positioned beneath furniture or wedged between furniture and the floor, the controller 74 may instruct the active suspension system 100 to retract the wheels 58A, 58B toward the chassis 52, which may reduce the chassis clearance 68A, 68B and, in general, reduce the effective clearance of the entire cleaning robot. For example, in some embodiments, the pressure sensors may detect that the downward force on the wheels 58A, 58B may have increased above a force threshold or value range, such that the controller 74 may determine that the movement of the cleaning robot 50 may be restricted or limited. Similarly, if the pressure sensors detect that the downward force on the wheels 58A, 58B may have decreased below a force threshold or value range, the controller 74 may determine that the movement of the cleaning robot 50 may be restricted or limited. In some embodiments, an increase in current in one or more drive motors 78 may be detected, which may indicate that the wheels 58A, 58B may be unable to rotate due to a downward force above a threshold acting on the cleaning robot 50. In this case, the controller 74 may instruct the active suspension system 100 to retract the wheels 58A, 58B in order to reduce the gap 68 of the chassis 52 and free up the cleaning robot 50 for more freedom of movement.

[0081] Figure 12is a flow chart of an embodiment of a method 900 for releasing a cleaning robot 50 from a position where its mobility may be restricted using the active suspension system 100. At 902, a position where mobility may be restricted may be detected via one or more sensors (e.g., sensor 53) on the cleaning robot and / or controller 74. At 904, the method may include determining whether the current used by one or more of the drive motors 78 for wheels 58A, 58B is below a minimum current threshold, which may indicate that one or more of the wheels may be slipping or have lost contact with the floor due to being caught on an object or furniture. If the current is determined to be below the current threshold, at 910, the active suspension system 100 may raise the active suspension height (e.g., chassis clearance 68) of one or more of the wheels 58A, 58B to release the cleaning robot 50 from the obstacle. At 906, the method may include determining whether the current used by one or more of the drive motors 78 is above a maximum current threshold, which may indicate that the cleaning robot 50 may be in a position where mobility may be restricted between an object and the floor. If yes, then at 912, the active suspension system 100 can reduce the active suspension height, which can reduce the overall clearance of the cleaning robot 50 and release it from the mobility-restricted position. At 908, the method can include determining whether any other parameters can be detected that can indicate whether the mobility of the cleaning robot 50 may be limited due to being positioned on top of an object, below an object, or otherwise. If yes, then at 914, the active suspension system 100 can include adjusting the suspension height accordingly in an attempt to release the cleaning robot 50 from the mobility-restricted position. At 916, the method can include detecting whether the cleaning robot 50 remains in the mobility-restricted position. If yes, the method can include iterating the process described in 904-914 to release the cleaning robot from the mobility-restricted position.

[0082] Stop brush roller when not in use

[0083] In some embodiments, the active suspension system 100 can be used to preserve battery life or otherwise reduce power usage, such as by stopping or reducing the use of certain robot components when they may not be in use. For example, as described herein, in various situations, it may be advantageous for the active suspension system 100 of the cleaning robot 50 to increase the chassis clearance height 68 below the chassis 52, for example by extending the wheels 58A, 58B away from the main body of the cleaning robot. In some embodiments, this may be done to avoid obstacles (e.g., wires, toys, etc.), adjust suction power, etc. In some such scenarios, certain components of the cleaning robot 50, such as the brushroll, may no longer be in contact with the target surface or may otherwise not be used in the current cleaning mode. For example, the brushroll may be located on the lower portion 56 of the cleaning vacuum cleaner 50 near the vacuum cleaner and may agitate debris (e.g., dust, dirt, food particles, etc.) that may otherwise adhere to the target surface, allowing the vacuum cleaner to pull it into the cleaning robot, thereby cleaning the target surface. However, in some embodiments where the active suspension system 100 can increase the undercarriage clearance 68 to a height where the brushroll may no longer be effective (e.g., no longer contacting the target surface), the controller 74 can be configured to shut off the brushroll, such as by instructing the brushroll motor to stop rotating the brushroll. By doing so, the cleaning robot 50 can conserve battery life by not consuming power to rotate the brushroll when debris cannot be effectively agitated for cleaning due to the undercarriage clearance height, or if a particular cleaning mode does not actively use the brushroll.

[0084] In some embodiments, the controller 74 can instruct the brushroll motor to stop any time the active suspension system 100 may extend the ride height 68 beyond a predetermined threshold height, such that the brushroll may no longer be effective or may interfere with an action (e.g., clearing an object). Such objects for clearance can be identified in various ways using various sensors (such as cameras, LIDAR, etc.). In some embodiments, the brushroll motor can be configured to stop or slow the rotation of the brushroll when the current drawn from the brushroll motor may drop below a minimum threshold current level. In some embodiments, when the brushroll motor current may drop below the minimum level, it may indicate that the brushroll may be encountering very little resistance and may have been lifted off the target surface. In some embodiments, the brushroll motor may then periodically rotate the brushroll to monitor current draw and, for example, with the assistance of the controller 74, determine whether the current draw may have increased beyond the minimum current level and, therefore, the brushroll may have re-engaged with the floor. In some embodiments, the brushroll may not stop, but instead may slow down to a minimum speed so that the motor can detect the increase in current level and, therefore, the brushroll may re-engage with the floor or other target surface. In some embodiments, monitoring of the brush roll current can be used in conjunction with other sensors (e.g., cameras, LIDAR, proximity sensors, etc.) to determine whether the cleaning robot 50 may have encountered an obstacle or may have cleared the obstacle so that the active suspension system 100 can extend or retract the wheels 58A, 58B.

[0085] Figure 13 1 is a flow chart of an embodiment of a method 1000 for maintaining robot battery life and energy efficiency using the active suspension system 100 by stopping or slowing certain robot components in certain scenarios. At 1002, the method may include using the active suspension system 100 to increase the chassis clearance height 68 for one or more scenarios described herein or other scenarios. At 1004, the method may include determining whether the chassis clearance height is above a threshold chassis clearance height. If not, the robot 50 and / or controller 74 may continuously or periodically monitor the chassis clearance. If the chassis clearance height exceeds the threshold, at 1006, the method may include stopping the brushroll to conserve battery power or other wear, for example, while the clearance height may be such that continued rotation of the brushroll may be less effective or efficient. At 1008, the method may include continuously or periodically monitoring the chassis clearance height 68 to determine whether the clearance height remains above the threshold chassis clearance height or has dropped below the threshold. If the chassis clearance height is no longer above the threshold clearance height, the method may include restarting the brushroll.

[0086] In some embodiments, the method may further include, once the chassis clearance height 68 has increased at 1002, monitoring the current used by the brushroll motor to determine, at 1014, whether the current used by the brushroll motor (i.e., "brushroll current") is above or below a minimum threshold current level. If the current is not below the minimum threshold current level, the method may include continuing to monitor the current level continuously or periodically. If the controller or robot otherwise determines that the brushroll current is below the minimum threshold current level, the robot and / or controller may stop the brushroll motor from rotating the brushroll at 1016, for example, to conserve battery power or otherwise improve efficiency. In some embodiments, the method may include, at 1018, periodically rotating or attempting to rotate the brushroll motor to monitor how much current the motor draws to cause these rotations. If, at 1020, it is determined that the brushroll current remains below the minimum threshold current level, the method may include continuing to periodically rotate and monitor the brushroll current. If the brushroll current increases above the minimum threshold current level, the method may include restarting the brushroll at 1010.

[0087] The foregoing description and accompanying drawings merely explain and illustrate the present invention, and the present invention is not limited thereto. Although the description has been described with respect to certain embodiments or examples, many details have been set forth for illustrative purposes. Therefore, the foregoing merely illustrates the principles of the present invention. For example, the present invention may have other specific forms without departing from the spirit or essential features of the present invention. The described arrangements are illustrative and non-restrictive. For those skilled in the art, the present invention is susceptible to additional embodiments or examples, and some of the details described in this application may vary considerably without departing from the basic principles of the present invention. Therefore, it should be understood that those skilled in the art will be able to design various arrangements that, although not explicitly described or shown herein, embody the principles of the present invention and are therefore within the scope and spirit of the present invention.

Claims

1. A method for controlling a robotic cleaning device, the method comprising: detecting, via one or more sensors, a soiled area on a target surface for cleaning; activating an active suspension system to decrease a distance between a chassis of the robotic cleaning device and the target surface, thereby increasing pressure applied by a cleaning pad mounted to the chassis of the robotic cleaning device; monitoring, via one or more processors, one or more parameters of the robotic cleaning device to determine whether the one or more parameters are outside of a threshold parameter range; adjusting the active suspension system if the one or more parameters are outside the threshold parameter range; as well as The active suspension system is deactivated when it is detected that the dirty area on the target surface is cleaned.

2. The method according to claim 1, wherein Deactivating the active suspension system includes returning the distance between the chassis and the target surface to a default distance.

3. The method according to claim 1, wherein The one or more parameters include pressure sensed between the cleaning pad and the chassis.

4. The method according to claim 3, further comprising: When the pressure is below the threshold parameter range, the active suspension system is activated to further reduce the distance between the chassis and the target surface.

5. The method according to claim 3, further comprising: When the pressure is above the threshold parameter range, the active suspension system is activated to increase the distance between the chassis and the target surface.

6. The method according to claim 1, wherein The one or more parameters include slippage detected between the cleaning pad and the chassis.

7. The method according to claim 6, further comprising: When the detected slip is above the threshold parameter range, the active suspension system is activated to further reduce the distance between the chassis and the target surface.

8. The method according to claim 6, further comprising: When the detected slip is below the threshold parameter range, the active suspension system is activated to increase the distance between the chassis and the target surface.

9. A method of controlling a robotic cleaning device, the method comprising: detecting a location where the mobility of the robotic cleaning device is restricted; determining that a current draw of a drive motor controlling rotation of one or more wheels of the robotic cleaning device is above a predetermined current range; Based on determining that the current draw of the drive motor is above the predetermined current range, an active suspension system is activated to reduce a distance between a chassis of the robotic cleaning device and a target surface.

10. The method of claim 9, further comprising detecting whether the angle of the chassis exceeds a threshold angle.

11. The method according to claim 9, wherein Detecting the restricted mobility position may include detecting a downward force on one or more wheels of the robotic cleaning device exceeding a force threshold.

12. The method according to claim 9, wherein The active suspension system reduces the distance to the chassis of the robotic cleaning device by retracting one or more wheels of the robotic cleaning device toward the chassis.

13. A method of controlling a robotic cleaning device, the method comprising: detecting a location where the mobility of the robotic cleaning device is restricted; determining that a current draw of a drive motor controlling rotation of one or more wheels of the robotic cleaning device is below a predetermined current range; Based on determining that the current draw of the drive motor is below the predetermined current range, an active suspension system is activated to increase a distance between a chassis of the robotic cleaning device and a target surface. The method of claim 13 , further comprising detecting whether the angle of the chassis exceeds a threshold angle.

15. The method according to claim 14, further comprising: When the angle of the chassis exceeds a threshold angle, the distance between the chassis and the target surface is increased.

16. The method according to claim 13, wherein: Detecting the restricted mobility position may include detecting a downward force on one or more wheels of the robotic cleaning device below a threshold force range.

17. The method according to claim 13, wherein: The active suspension system reduces the ride height from the chassis of the robotic cleaning device by extending one or more wheels of the robotic cleaning device away from the chassis.

18. The method according to claim 13, wherein The robotic cleaning device includes a first wheel and a second wheel, and wherein increasing the distance between the chassis and the target surface includes extending both the first wheel and the second wheel.

19. The method according to claim 13, wherein The robotic cleaning device includes a first wheel driven by a first drive motor and a second wheel driven by a second drive motor, and wherein increasing the distance between the chassis and the target surface includes extending only the first wheel when the current consumption of the first drive motor is below the predetermined current range.

20. The method according to claim 13, wherein The robotic cleaning device includes a first wheel driven by a first drive motor and a second wheel driven by a second drive motor, and wherein increasing the distance between the chassis and the target surface includes extending only the first wheel and the second wheel when the current consumption of the first drive motor and the second drive motor are both below the predetermined current range.

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