SURFACE MAINTENANCE MACHNE WITH DUST MITIGATION

RELATED APPLICATIONS

[0001]This application claims priority to U.S. Provisional Patent Application No. 63/745,904, filed Jan. 16, 2025, the entire contents of which are incorporated herein by reference.

FIELD

[0002]This disclosure generally relates to surface maintenance machines. More particularly, the present disclosure relates to controlling side brush speed near obstacles, for use with such machines.

BACKGROUND

[0003]Surface maintenance machines include vehicles and devices that can be self-powered, towed, pushed, and/or manually powered. Surface maintenance machines commonly include a cleaning head having one or more maintenance tools (e.g., one or more rotating brushes) operated by one or more motors. Each maintenance tool is configured to perform a desired treating operation on the surface. For example, in cases where the surface maintenance machine is a floor surface maintenance machine, one or more brushes/brooms sweep dirt and debris from a floor surface and throw loose debris into a hopper. The brush/broom may be housed in a maintenance tool chamber in such cases.

[0004]Typically during the operation of a sweeper, sweeping tools that move and direct debris and generate particulate may cause adverse air currents that can be hard to control. In such cases, a vacuum system directing airflow in a predetermined direction can be commonly used to control the particulate and adverse air currents that are generated during the sweeping process. The surface maintenance machine may also include skirt assemblies comprising a single row of skirts on the front, lateral sides, and/or rear of the machine, under which vacuum may be generated by the vacuum system thereby drawing particulate toward the hopper.

[0005]Surface maintenance machines can include a side brush to maintain a larger footprint and/or coverage of the surface. The side brush can help sweep particulate (especially particulate that is out of reach of the main brush/broom) and draw it towards the main brush/broom, the vacuum system, and the hopper. However, there are some instances where the side brush can generate a particulate cloud proximate to the machine. This particulate can negatively impact sensors, particularly those on the exterior of the surface maintenance machine.

SUMMARY

[0006]In general, this disclosure is directed to surface maintenance machines and, more particularly, to controlling side brush speed near obstacles, for use with such machines. In one example, the present disclosure includes a method for cleaning with a surface maintenance machine. The method can comprise monitoring surroundings of the surface maintenance machine through one or more sensors. The method can also comprise detecting, by the one or more sensors, an obstacle adjacent a first side of the surface maintenance machine, where the first side is a lateral side of the surface maintenance machine directly connected to the side brush. The method can also comprise, in response to detecting the obstacle adjacent the first side of the surface maintenance machine, automatically reducing a rotational speed of the side brush.

[0007]In another example, the present disclosure includes a method for cleaning with a surface maintenance machine. The method can comprise monitoring surroundings of the surface maintenance machine through one or more sensors. The method can also comprise determining that the surface maintenance machine is cleaning adjacent to an obstacle. The method can also comprise detecting, by the one or more sensors, a particulate cloud in the surroundings of the surface maintenance machine, where the detecting is while the surface maintenance machine is cleaning adjacent to the obstacle. The method can also comprise, in response to detecting the particulate cloud, automatically reducing a rotational speed of the side brush.

[0008]In another example, the present disclosure includes a surface maintenance machine comprising a body. The surface maintenance machine can also comprise wheels for supporting the body for movement over a surface. The surface maintenance machine can also comprise a cleaning tool chamber housed towards a bottom portion of the body. The surface maintenance machine can also comprise one or more rotary brooms housed in the cleaning tool chamber. The surface maintenance machine can also comprise a vacuum system adapted to generate vacuum for drawing particulate swept by the one or more rotary brooms, where the vacuum system comprises one or more filters. The surface maintenance machine can also comprise a side brush positioned laterally on the surface maintenance machine to maintain a larger footprint of the surface, where the side brush is connected to a first side of the machine. The surface maintenance machine can also comprise one or more sensors. The surface maintenance machine can also comprise a side brush speed program operatively connected to the side brush, where the side brush speed program is configured to automatically reduce a rotational speed of the side brush in response to detecting an obstacle adjacent the first side of the surface maintenance machine.

[0009]The details of one or more examples are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims.

BRIEF DESCRIPTION OF DRAWINGS

[0010]The following drawings are illustrative of particular embodiments of the present invention and, therefore, do not limit the scope of the invention. The drawings are not necessarily to scale (unless so stated) and are intended for use in conjunction with the explanations in the following detailed description. Embodiments of the invention will hereinafter be described in conjunction with the appended drawings, wherein like numerals denote like elements.

[0011]FIG. 1 is a perspective view of an exemplary surface maintenance machine during edge cleaning, according to an embodiment.

[0012]FIG. 2 is a side perspective view of the surface maintenance machine shown in FIG. 1, according to an embodiment.

[0013]FIG. 3 is a front perspective view of the surface maintenance machine shown in FIG. 1, according to an embodiment.

[0014]FIG. 4 is a bottom perspective view of the surface maintenance machine shown in FIG. 1, according to an embodiment.

[0015]FIG. 5 is a flow diagram of a first exemplary embodiment of a method of automatically reducing side brush speed of a surface maintenance machine, according to an embodiment.

[0016]FIG. 6 is a flow diagram of a second exemplary embodiment of a method of automatically reducing side brush speed of a surface maintenance machine, according to an embodiment.

DETAILED DESCRIPTION

[0017]The following detailed description is exemplary in nature and is not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the following description provides some practical illustrations for implementing exemplary embodiments of the present invention. Examples of constructions, materials, dimensions, and manufacturing processes are provided for selected elements, and all other elements employ that which is known to those of ordinary skill in the field of the invention. Those skilled in the art will recognize that many of the noted examples have a variety of suitable alternatives.

[0018]FIG. 1 is a perspective view of an exemplary surface maintenance machine 100 that is cleaning along an edge 105. In the illustrated embodiment shown in FIG. 1, the surface maintenance machine 100 is a ride-on machine 100 used to treat hard surfaces. In other embodiments, the surface maintenance machine 100 can be a walk-behind machine 100 or a towed-behind machine 100, such as the surface maintenance machine 100 described in U.S. Pat. No. 8,584,294 assigned to Tennant Company, the disclosure of each of which is hereby incorporated by reference in its entirety. In some embodiments, surface maintenance machine 100 can be operated in a manually driven mode, an autonomously driven mode, a semi-autonomously driven mode (for example, assisted driving), interchangeably operated between a manually driven mode and an autonomously driven mode, etc.

[0019]The surface maintenance machine 100 can perform maintenance tasks such as sweeping (e.g., removing dust, debris or other particulate from the surface). As referred to herein, particulate may refer to dust as well as large and loose debris). In some cases, the machine 100 is a mechanical sweeper configured for mechanically moving particulate from the surface. Alternatively, the machine 100 can be a combination sweeper-scrubber, or a burnisher. Other operations such as scrubbing, polishing (burnishing) a surface are also contemplated. The surface can be a surface, pavement, road surface, and the like.

[0020]Embodiments of the surface maintenance machine 100 include components that are supported on a mobile body 102. As best seen in FIG. 1, the mobile body 102 comprises a frame 104 supported on wheels 106 for travel over a surface, on which a surface maintenance operation is to be performed. The mobile body 102 may include operator controls (not shown) and a steering control such as a steering wheel 108. In some embodiments, the machine 100 includes a seat 112. The surface maintenance machine 100 can be powered by an on-board power source such as one or more batteries, a fuel-cell, or an internal combustion engine (not shown). The power source can be proximate the front of the surface maintenance machine 100, or it may instead be located elsewhere, such as within the interior of the surface maintenance machine 100, supported within the frame 104, and/or proximate the rear of the surface maintenance machine 100. Alternatively, the surface maintenance machine 100 can be powered by an external electrical source (e.g., a power generator) via an electrical outlet. The interior of the surface maintenance machine 100 can include electrical connections (not shown) for transmission and control of various components.

[0021]The machine 100 can include a maintenance tool for performing one or more cleaning tasks. For instance, the maintenance tool can perform sweeping, scrubbing, polishing/burnishing, striping, dry and wet vacuuming, and the like. Many different types of maintenance tools are used to perform such cleaning operations on the surface. These include sweeping, scrubbing brushes, polishing/burnishing and/or buffing pads. In the embodiments illustrated herein, the machine 100 is a surface maintenance machine 100 wherein the maintenance tool can be one or more rotary brooms 110 (depicted in FIG. 4). Alternatively, the machine 100 can be a combination sweeper-scrubber in which case the machine 100 can include one or more scrub-brushes in addition to the broom 110, or a burnisher in which case the machine 100 can include one or more burnishing/polishing pads. The broom 110 can extend from the underside of the machine 100 and can be supported by an elongated cleaning head (not shown). While not illustrated, the cleaning head can house other maintenance tools (e.g., side brooms, scrubbing brush, and burnishing/polishing pads). The cleaning head assembly can be attached to the body 102 of the machine 100 such that the cleaning head can be lowered to an operating position and raised to a transport position. The cleaning head assembly is connected to the machine 100 using any known mechanism, such as a suspension and lift mechanism such as those illustrated in U.S. Pat. No. 8,584,294 assigned to Tennant Company, the disclosure of each of which is hereby incorporated by reference in its entirety. The rotary broom 110 can be releasably loaded to or unloaded from the surface maintenance machine 100.

[0022]While a rotary broom 110 is depicted (in FIG. 4) and discussed herein, other maintenance tools can also be provided. In cases where the machine 100 is a combination sweeper-scrubber, or a burnisher, the cleaning tool chamber can hold other maintenance tools (e.g., a scrub brush, a burnishing pad and the like) raised and lowered by a cleaning head (not shown).

[0023]In some embodiments, the machine 100 can include a hopper 120 (depicted in FIG. 4) and a vacuum system (not depicted). The vacuum system can comprise a vacuum source, such as a fan housed in a fan housing. In some cases, the vacuum system can include a filtration system including a filter and other components which provide for support and function thereof. In the illustrated embodiment, the hopper 120 is positioned toward the back/rear of the machine 100. Alternatively, the hopper 120 can be positioned toward the front of the machine 100. The filtration system, while not illustrated, can include one or more filters. One example of a filtration system is described in the commonly-assigned U.S. Pat. No. 8,099,828, the disclosure of which is hereby incorporated by reference. In operation, the vacuum source can generate an airflow such that air flows through the hopper 120, the filtration system, and then can exit the machine 100.

[0024]In some cases, the cleaning tool/broom 110 can rotate within and be housed in a cleaning tool chamber 115 (depicted in FIG. 4). In cases where the machine is a combination sweeper-scrubber, or a burnisher, the cleaning tool chamber 115 can hold other cleaning tools (e.g., a scrub brush, a burnishing pad and the like) raised and lowered by a cleaning head (not shown). As an example, the broom 110 can sweep particulate from a surface and push particulate from the surface into the hopper 120 as it rotates within the cleaning tool chamber 115. The cleaning tool chamber 115 can be vacuumized and can communicate with the hopper 120.

[0025]In some embodiments, the rotary broom 110 extends from a bottom surface of the body 102 of the machine 100 and is rotatable. The rotation of the broom 110 can be driven by a driver (e.g., a motor, not shown). In some cases, the broom 110 can rotate at speeds of between about 500 rotations per minute and about 700 rotations per minute. The rotation of the rotary broom 110 generates air currents within the cleaning tool chamber 115. As the broom rotates, particulate are picked up (e.g., swept) from the floor and acted upon by the vacuum system. In some cases, at certain broom rotation speeds, the debris or particulate is pushed directly into the hopper 120. In sweeping systems known in the art, air currents due to broom rotation can have an associated positive pressure therewith such that particulate may sometimes be thrown off towards the outside of the machine 100. In some cases (not depicted), the machine 100 comprises one or more skirt assemblies for preventing dusting due to air currents generated by the broom 110. In such cases, the skirt assembly can extend around side(s) of the cleaning tool chamber 115.

[0026]As depicted in FIG. 1, the machine 100 can have one or more side brushes 114 positioned laterally on the machine 100 to maintain a larger footprint and/or coverage of the surface. Although a single side brush 114 is depicted and discussed herein, machine 100 may include one or more side brushes 114.

[0027]In some embodiments, the machine 100 can include a controller 130. The controller 130 can be an internal component of the surface maintenance machine 100, in some embodiments. The controller 130 can include processing circuitry and be supported at the body 102, and the controller 130 can be configured, via the processing circuitry, to execute one or more of the various features disclosed herein. For example, controller 130 can be configured to execute a side brush speed program to perform a method of reducing side brush speed (such as method 500 (FIG. 5) and/or method 600 (FIG. 6)). The controller 130 can be, for example, a programmable processor that is configured to execute non-transitory computer-readable instructions stored in a non-transitory memory component (e.g., at the controller 130). Execution of the non-transitory computer-readable instructions at the controller 130 can cause the machine 100 to perform one or more various features disclosed herein. Although the controller 130 may be referred to herein as a singular controller, the controller 130 can include one or more controllers 130.

[0028]In surface maintenance machines (such as machine 100), there may be various sensors 170, 180 (e.g., environmental sensors, cleaning quality sensors, cleaning efficiency sensors, vision sensors, light detection sensors, ranging sensors, etc.) on the exterior of the surface maintenance machine. For example, the various sensors may be on an exterior surface of the body 102 of the surface maintenance machine 100. These sensors 170, 180 can be negatively affected by particulate, particularly if particulate gets too close to the sensors 170, 180. Therefore, if particulate is not contained by the surface maintenance machine, it can negatively impact the various sensors. In some embodiments, the surface maintenance 100 may include at least a front sensor and a rear sensor.

[0029]In an example embodiment, the sensors 170, 180 can include one or more of visible light and/or thermal (infrared) vision cameras, LIDAR sensors, laser beacons, ultrasound and/or ultrasonic sensors, and the like to scan and detect features (such as physical boundaries, obstacles, objects, etc.) in the ambient environment (e.g., the surroundings) of the machine 100. For example, sensors 170 and/or 180 can, in some instances, be LIDAR sensors such as 2D LIDAR sensors, multi-echo LIDAR sensors, etc. In some embodiments, the sensors 180 can be provided at various, spaced apart locations on the machine 100 (e.g., front, lateral sides, rear, and the like) so as to obtain data corresponding to areas at different locations around the machine 100 over a relatively wide field of view. The sensors 170, 180 can be coupled to a controller 130.

[0030]In FIG. 1, machine 100 includes sensors 180 in a front left corner and a back right corner of the machine 100. In some particular embodiments, the field of view of the sensors 180 can correspond to an angle of between about 200 degrees and about 300 degrees, and a radius of between about 50 feet and 150 feet. In one yet more particular embodiment, the field of view of the sensors 180 can be approximately 240 degrees and a radius of approximately 90 feet. By having the sensors 180 at opposite corners of the machine 100, the sensors 180 together can have a full field of view around the machine 100. In some embodiments, sensors 180 are lower on the machine 100 and are at a level/height similar to the wheels 106 of the machine 100.

[0031]When operating a cleaning machine such as machine 100, various particulate (e.g., dust, etc.) can be generated and/or stirred up. This particulate can negatively affect the sensors 180 of the machine. Sensors 180 can be particularly affected when particulate gets near the sensors 180.

[0032]During cleaning operations, there can be instances where the surface maintenance machine 100 is cleaning along an edge, obstacle, object, etc. 105. This is referred to herein as edge cleaning, but can include cleaning along an edge, obstacle, object, or the like. An edge 105, as referred to herein, can be a border, object, obstacle, etc. that is a vertical obstruction/obstacle for the machine 100. Edge 105 can also be referred to herein as an obstacle 105. In some embodiments, edge 105 is a wall and edge cleaning refers to machine 100 cleaning along a wall. Other examples of an edge/obstacle 105 include forklifts, pallets, shelving, people, etc. In some embodiments, edge/obstacle 105 has a height greater than or equal to the height of the sensor(s) (e.g., sensors 180).

[0033]In some embodiments, various components of the machine, such as side brush 114, may generate a small amount of particulate and/or particulate clouds. The particulate, especially if it clouds near the sensors 180, can negatively impact sensor 180 performance and/or machine 100 performance.

[0034]In instances when there is a small amount of space between the particulate and a surrounding vertical surface (such as an object, border, wall, obstacle, etc.), the sensors 180 can be particularly affected by the particulate. An edge/obstacle, such as edge 105, is an example of a vertical surface that can negatively impact the sensors 180. For example, when machine 100 is edge cleaning (i.e., cleaning along edge/obstacle 105), the machine may be very close to the edge 105. Additionally, when machine 100 is edge cleaning, the side brush 114 is susceptible to generating particulate due to its proximity to the edge/obstacle 105, as the side brush 114 can come into contact with the edge 105 which can create particulate clouds. Therefore, when machine 100 is cleaning along edge/obstacle 105, the side brush 114 can generate particulate clouds that are near the edge 105. In some instances, in addition to helping generate particulate, the edge 105 can block the particulate from flowing away from the machine (due to the obstacle/obstruction of the edge 105) and can cause any generated particulate to cloud and remain in areas near the machine 100 and the sensors 180 (due to the edge 105 preventing/limiting particulate from flowing the other direction). This can cause various issues for the machine 100 (as discussed herein).

[0035]In some embodiments, skirting can be used to help funnel and control particulate, however skirting around the side brush 114 could prevent edge cleaning and reduce and/or eliminate machine 100's ability to effectively clean along an edge 105. Similarly, adding a blower and/or vacuum near the side brush 114 to help manage particulate generated by the side brush 114 may be ineffective. For instance, a blower may simply blow/move the particulate cloud but not reduce and/or eliminate it, therefore the sensors 180 still may not be able to filter through the particulate cloud when edge cleaning. Vacuum sources may need to be very close to the ground in order to be effective in eliminating particulate generated by the side brush 114, which can cause the vacuum source to be very susceptible to clogging from even light amounts of particulate or debris.

[0036]Therefore, to prevent particulate from negatively affecting the sensors 180, particularly when cleaning near an obstacle/edge 105, the amount of particulate generated by the machine 100 can be reduced. As discussed herein, the side brush 114 is susceptible to generating particulate when cleaning along an obstacle such as edge 105, thus reducing/eliminating particulate generated by the side brush 114 can help improve sensor 180 performance. To effectively reduce and/or eliminate particulate generated by side brush 114, the side brush 114 speed (i.e., a rotational speed) can be reduced while edge cleaning (i.e., cleaning near an edge, obstacle, object, etc.). By reducing the rotational speed of the side brush 114, the side brush 114 can make fewer passes along the edge 105 (and thus have less side brush 114 contact and/or compression against the edge 105), which can then generate less particulate. Generating less particulate can reduce and/or eliminate the particulate clouds that are in close proximity to and/or picked up by the sensors 180, as the small amount of particulate that may still be generated by the side brush 114 can be collected by the broom 110 and/or vacuum system as intended. In some embodiments, the machine 100 and the side brush 114 are operatively connected to a program, such as a software program, for controlling and reducing side brush speed of the side brush 114. The program (referred to herein as a side brush speed program) can execute methods such as method 500 and/or method 600, in some instances.

[0037]In some embodiments, as the broom 110 rotates and the surface maintenance machine 100 cleans the surface, the one or more filters within the filtration system (that can be part of the vacuum system, as discussed herein) can become clogged. A clogged filter can cause additional particulate and particulate clouds near the sensors 180, which can negatively impact the sensors 180 and/or the machine 100. Additionally, as a filter clogs and becomes loaded with dust, particulate, etc., airflow can reduce from the broom to the hopper, which can also negatively impact the machine 100.

[0038]The one or more filters can be shaken out in order to unclog the filter. The process of shaking out the filter and unclogging it is referred to herein as a shake back. In some embodiments, the shake back can be a manual process. In some embodiments, the filter system (within the vacuum system) can include a shaker motor, and the shake back can occur automatically by running the shaker motor for an amount of time (for example, a number of seconds). The filtration system, the one or more vacuums, and the shaker motor can be connected to the controller 130, in some embodiments. The controller 130 can be configured to execute a program to automatically perform a shake back. In some instances, automatically performing a shake back can be a part of a program such as a side brush speed program to perform a method of reducing side brush speed (such as method 500 (FIG. 5) and/or method 600 (FIG. 6)) in order to further help prevent generation of particulate clouds during edge cleaning.

[0039]In some embodiments, the filtration system can have the capability (for example, through one or more sensors) to measure filter differential pressure. Further, in some instances, there can be a predetermined shake back pressure threshold and if the filter differential pressure drops below the predetermined shake back pressure threshold a shake back can be automatically triggered to unclog the filter.

[0040]In some embodiments, even if the filter pressure has not dropped below the shake back pressure threshold, a shake back can still be automatically triggered when a particulate cloud is detected (for example, by sensors 180). As a clogged filter can cause excess particulate and particulate cloud(s), automatically performing/triggering a shake back once particulate is detected can help reduce and/or prevent further particulate clouds, thus improving the performance of the sensors 180 and the surface maintenance machine.

[0041]As discussed herein, the various brooms and/or brushes of the machine 100 can generate particulate (for example, when the broom and/or brush comes into contact with an object/obstacle). In some embodiments, as the broom 110 rotates and the surface maintenance machine 100 cleans the surface, particulate can be generated due to the cleaning and the broom's (110) contact with the surface. In these instances, to help reduce the particulate being generated by the broom 110, the broom 110 speed and/or the down force of the broom 110 can be reduced. Adjusting the broom 110 speed and/or the down force of the broom 110 can be done by adjusting the settings of the broom 110 (for example, through a program, such as a side brush speed program, executed by the controller 130). In some embodiments, the broom speed and/or the down force are reduced automatically.

[0042]Particulate generated by the machine 100 can also be reduced through increasing vacuum fan voltage, in some embodiments. As discussed herein, machine 100 can include a vacuum system to help direct airflow and particulate flow in a certain direction (for example, into the cleaning tool chamber and/or the hopper). Increasing the voltage of the vacuum fan can help increase the amount of airflow and particulate flow, which can help increase the amount of particulate being picked up by the vacuum and directed to the hopper. This can help contain the particulate and prevent/reduce particulate (for example, the particulate generated by the broom 110) from escaping the machine 100 and being exposed to the sensors 180. In some instances, adjusting the vacuum fan voltage can be done by adjusting the vacuum settings (for example, through a program, such as a side brush speed program, executed by the controller 130. In some embodiments, the vacuum fan voltage is increased automatically.

[0043]As discussed herein and depicted in FIG. 2, sensors 180 can be close to the ground/surface. For instance, sensors 180 can be a small distance 225 from the surface, and can be in line (shown by horizontal arrow 215) with the rear tire 106. In some instances, sensor 180 is at a height 225 less than or equal to a height of the top of the rear tire 106. Being so close to the ground gives the sensors 180 the capability to better detect objects and obstructions that are low to the ground and/or within a path of the machine 100. However, as discussed herein, being close to the surface/ground makes the sensors 180 more susceptible to particulate clouds, as the particulate clouds may also be close to the surface/ground.

[0044]Referring to FIG. 3, a front view of the surface maintenance machine 100 is depicted. In some embodiments, side brush 114 is depicted as being lifted in a transport position. Although side brush 114 is depicted in a transport position, side brush 114 may be in other positions. For example, side brush 114 can be in a cleaning position (for example, closer to the ground/surface).

[0045]If the side brush 114 were rotating at a typical rotational speed (e.g., a rotational speed the same/similar to instances when the machine 100 is not along and/or near an edge/obstacle 105), the side brush 114 may generate a particulate cloud such as particulate cloud 350. In some instances, this particulate cloud 350 can be caused by the side brush 114 having contact with the surface and/or the edge 105. For example, side brush 114 can compress against the edge 105, which can cause a particulate cloud 350. This particulate cloud 350 can be at a similar level 380 to the sensors 180, which can increase the chances of the sensors 180 (particularly the front sensor 180 depicted in FIG. 3) being negatively impacted by the particulate cloud 350.

[0046]When the machine 100 is cleaning along edge/obstacle 105, the machine can be very close (i.e., only a small distance 370) away from the edge 105. In some embodiments, this distance 370 can be less than or equal to 0.5 meters. In some embodiments, this distance 370 can be less than or equal to 2 meters. In some embodiments, this distance 370 can be between approximately 1.5 meters-2 meters. When the machine 100 is close to the edge 105 (as occurs during edge cleaning), any generated particulate cloud 350 may also be very close to or even touching the edge 105.

[0047]As discussed herein, when the particulate 350 is close to an obstacle/edge (such as obstacle/edge 105, the sensors 180 and their performance are negatively impacted. For instance, when particulate 350 is close to the sensors 180, the particulate 350 can be detected by and/or come into contact with the sensors 180. In some instances, this can affect sensor 180 performance and/or machine 100 performance. For example, the particulate 350 can contaminate sensor 180 lenses over time which can cause various sensor detection and/or functionality issues. In another example, particulate 350 can impact sensor 180 data and can cause incorrect data to be gathered by the sensors 180, which can cause issues with the sensors 180 and/or the machine 100. In another example, the escaped particulate can be detected by the sensors 180 and perceived as an object/obstacle in the machine's path of motion (which can cause the machine 100 to slow down, stop, generate an operating assist requiring human intervention, and/or other issues). Further, even in instances where sensors (such as sensors 180) could have the capabilities to detect the particulate 350 but then filter it out and/or see through it in order to prevent it from being perceived as an obstacle, the particulate 350 could still be incorrectly detected/perceived due to its proximity to an actual obstacle (such as an edge, object, boundary, border, etc.).

[0048]By reducing the rotational speed of side brush 114 when cleaning in a close proximity to an edge/obstacle 105, particulate cloud 350 may not be formed, and instead any particulate generated and/or picked up by the side brush 114 may be swept into a path of the broom 110, vacuum, and hopper 120. The particulate path when the side brush 114 has a reduced rotational speed is depicted as particulate path 490 in FIG. 4. This can help prevent the sensors 180 and/or the machine 100 from being negatively impacted due to the particulate cloud 350.

[0049]In some embodiments, in order for particulate clouds (such as particulate cloud 350) to be reduced/eliminated and for particulate to follow a path such as particulate path 490, the side brush 114 may need to be reduced to a specific range of rotational speeds. For instance, a faster side brush 114 rotation allows the side brush 114 to pick up more particulate and debris from the surface and can allow for more different types of debris/particulate to be picked up. However, if the side brush 114 rotates too fast, particulate clouds can still form and be detected by the sensors 180. The slower the side brush 114 rotates, the less likely it is that the side brush 114 generates particulate clouds. However, the slower rotational speed can reduce the efficiency of the side brush 114, as the side brush 114 can be less efficient and effective at picking up particulate and debris from the surface.

[0050]Reducing the rotational speed of the side brush 114 to approximately 55% duty cycle reduces and/or eliminates particulate clouds that are generated by the side brush 114 while also maintaining a strong efficiency and effectiveness of the side brush 114. Duty, also referred to as duty cycle, is a ratio of a motor full-power duration to an interval period. Put differently, a duty cycle is a percentage of time that the motor's functionality/output is in its highest state. Therefore, a higher percentage duty cycle equates to a higher rotational speed of the side brush 114. In some embodiments, when machine 100 is operating in an open environment without any nearby obstacles/obstructions, the side brush 114 may have a rotational speed of 95% duty cycle (i.e., 95% of its highest functionality/state). Reducing the rotational speed of the side brush 114 to 55% duty cycle slows the brush speed down such that it is running at 55% of its highest functionality/state.

[0051]In some embodiments, side brush 114 can be reduced to a rotational speed of less than or equal to 55% duty cycle, in order to prevent particulate clouds from being formed by the side brush 114. In some embodiments, side brush 114 can be reduced to a rotational speed equal to, or approximate to 55% duty cycle, but not much less, as reducing the speed to much lower than 55% duty cycle can significantly reduce the effectiveness of the side brush 114. Therefore, in order to minimize dust generation but maintain reasonable cleaning performance of the side brush 114, the rotational speed of the side brush can be reduced to approximately 55% duty cycle. In some embodiments, 55% duty cycle may equate to approximately 40 revolutions per minute (rpm) and 95% duty cycle may equate to approximately 65 rpm. In some embodiments, 55% duty cycle and 95% duty cycle may equate to other rpms.

[0052]As depicted in FIG. 4, machine 100 can have four sides—a front side 410, two lateral sides 420, 430, and a back/rear side 440. While the side brush 114 may be considered to be connected to both the lateral side 420 and the front 410, lateral side 420 is the side referred to herein as the side brush side that is connected to the side brush 114. Edge/obstacle 105 can be considered adjacent to side 420 of the machine 100.

[0053]Referring to FIG. 5, an exemplary method 500 for automatically reducing side brush speed of a surface maintenance machine is depicted, according to some embodiments. In some embodiments, method 500 is executed by a program (e.g., a side brush speed program) operatively connected to a side brush (e.g., side brush 114) and/or a surface maintenance machine (e.g., surface maintenance machine 100). In some embodiments, side brush speed program is a software program within and/or connected to the surface maintenance machine 100. In some embodiments, the controller 130 (FIG. 1) can execute non-transitory computer-readable instructions to cause the surface maintenance machine 100 to be configured to perform method 500.

[0054]Method 500 can include operation 510 to monitor the surroundings of the surface maintenance machine through one or more sensors. The surroundings can also be referred to herein as the environment and/or ambient environment of the surface maintenance machine. In some embodiments, sensors 170 and/or 180 can be used to monitor the surroundings of the surface maintenance machine 100. As discussed herein, the machine 100 can include various sensors such as environmental sensors, cleaning quality sensors, cleaning efficiency sensors, vision sensors, light detection sensors, ranging sensors, etc. to help with the operations of the machine. In some embodiments, sensors 180 are vision sensors (e.g., 2D LIDAR sensors) that are configured to scan and detect features in the surroundings (e.g., ambient environment) of the surface maintenance machine 100. In some embodiments, the monitoring of the surroundings of the surface maintenance machine is a continuous real-time monitoring.

[0055]Method 500 can include operation 520 to detect an edge/obstacle adjacent a first side of the surface maintenance machine. In some embodiments, while monitoring the surroundings of the surface maintenance machine, the sensors 170 and/or 180 can detect an edge such as edge 105. This edge 105 can be adjacent at least side 420 of the surface maintenance machine. As discussed herein, side 420 can be the lateral side of the surface maintenance machine directly connected to the side brush.

[0056]In some embodiments, in order for an edge/obstacle to be considered adjacent a first side of the surface maintenance machine (such as side 420), the edge should be within a close enough distance of the side 420 and the surface maintenance machine 100. For example, in some instances, detecting the edge adjacent the first side of the surface maintenance machine includes detecting that the obstacle/edge (e.g., edge 105) is within approximately 1.5-2 meters of the first side (e.g., side 420) of the surface maintenance machine (e.g., machine 100). As discussed herein, when a machine is in close proximity to an edge/obstacle, the side brush may be more susceptible to generating particulate (as the side brush may come into contact with the edge/obstacle which can generate particulate). Alternatively or additionally, particulate within close proximity to an edge/obstacle is more likely to negatively impact the sensors 180 as the edge/obstacle can cause the particulate to cloud and/or can block/limit the particulate from flowing away from the machine 100 and the sensors 180. Therefore, when the surface maintenance machine 100 (e.g., side 420 of the surface maintenance machine) is within, for example, 1.5-2 meters of the edge/obstacle 105, particulate generated/swept by the side brush 114 can cloud up (i.e., form a particulate cloud) between the edge 105 and the sensors 180. This can negatively impact the sensors 180 due to the particulate's close proximity to the sensors 180 and the edge 105.

[0057]Method 500 can include operation 530 to automatically reduce a rotational speed of the side brush. In some embodiments, in response to detecting the edge/obstacle (e.g., edge 105) adjacent to the first side (e.g., lateral side 420) of the surface maintenance machine, the rotational speed of the side brush (e.g., side brush 114) can be automatically reduced. By automatically reducing the rotational speed of the side brush as soon as it is detected that the surface maintenance machine is along/near an edge (i.e., edge cleaning), the brush speed can be reduced prior to any particulate clouds being generated. This can prevent the particulate from clouding near the sensors and negatively impacting the sensors.

[0058]In some instances, reducing the side brush speed as soon as an edge is detected can slightly reduce the efficiency and effectiveness of the cleaning, as the slower rotational speed can have less efficiency/effectiveness compared to a faster rotational speed. However, in some instances, when the rotational speed of the side brush is reduced to approximately 55% duty cycle, the side brush 114 can maintain a strong efficiency and effectiveness (for example, only losing approximately 7% efficiency compared to a side brush at 95% duty cycle) while preventing particulate clouds from being formed by the side brush 114. In addition, reducing the rotational speed of the side brush as soon as an edge/obstacle is detected can improve sustainability of the surface maintenance machine 100 and the side brush 114 as the machine can use less energy compared to if it was spinning the side brush at a higher speed.

[0059]In some embodiments, as depicted in FIG. 5, method 500 can include operation 540 to detect that the edge/obstacle is no longer adjacent to the first side of the surface maintenance machine. For instance, a surface maintenance machine (such as machine 100) can stop cleaning along an edge (such as edge 105) and start cleaning in an open area without any nearby obstacles. In this instance, the surface maintenance machine 100, particularly the side 420 connected to the side brush 114, may no longer be adjacent to the edge 105. As discussed herein, in instances where a surface maintenance machine 100 is in an open area without any nearby obstacles, any generated particulate may be less susceptible to clouding near the sensors 180 as there is not an obstacle/edge to block flow of particulate and the particulate may more freely flow throughout the open area (as opposed to clouding near the machine 100 and the sensors 180). Further, side brush 114 may not generate any particulate clouds (or at least significantly smaller particulate clouds/amounts of particulate) as the side brush 114 will not be in contact with the edge 105. Therefore, once the surface maintenance machine 100 is no longer cleaning along an edge 105, the risk of the machine 100 and/or the sensors 180 being negatively impacted by the particulate is much smaller.

[0060]Thus, in some embodiments, method 500 can include operation 550 to automatically increase the rotational speed of the side brush. This can be in response to detecting that the edge/obstacle is no longer adjacent to the first side of the surface maintenance machine, in some instances. In some embodiments, increasing the rotational speed of the side brush 114 can include returning the side brush 114 to its rotational speed prior to the reduction in operation 530. For instance, the side brush 114 may have a first rotational speed, may be reduced to a second rotational speed, and may be increased back to the first rotational speed. In some instances, the side brush 114 may have been operating at approximately 95% duty cycle and/or a speed greater than 55% duty cycle and less than or equal to 95% duty cycle prior to operation 530, and the side brush 114 may be increased back to this speed in operation 550.

[0061]In some embodiments, the increase and/or decrease in rotational speed of the side brush can be linear (for example, more instantaneous) and can go directly from one speed to the next. In some embodiments, the increase and/or decrease in rotational speed can be more gradual, and the speed can gradually change from one speed to the next. A more gradual speed change can prevent abrupt speed changes, thus helping prolong the reliability/functionality of the side brush 114.

[0062]Referring to FIG. 6, an exemplary method 600 for automatically reducing side brush speed of a surface maintenance machine is depicted, according to some embodiments. In some embodiments, method 600 is executed by a program (e.g., a side brush speed program) operatively connected to a side brush (e.g., side brush 114) and/or a surface maintenance machine (e.g., surface maintenance machine 100). In some embodiments, side brush speed program is a software program within and/or connected to the surface maintenance machine 100. In some embodiments, the controller 130 (FIG. 1) can execute non-transitory computer-readable instructions to cause the surface maintenance machine 100 to be configured to perform method 600.

[0063]Method 600 can include operation 610 to monitor surroundings of the surface maintenance machine through one or more sensors. This operation can be the same/similar as operation 510 (FIG. 5), in some embodiments.

[0064]Method 600 can include operation 620 to determine that the surface maintenance machine is cleaning near an obstacle/edge (e.g., edge 105). In some embodiments, determining that the surface maintenance machine is cleaning near an obstacle/edge can include determining, or detecting, that a side of the machine 100 (such as side 420 connected to the side brush 114) is adjacent to an edge/obstacle 105. Being adjacent to an obstacle/edge 105, in some instances, can include being within a certain distance (such as 1.5-2 meters) of the edge 105.

[0065]Method 600 can include operation 630 to detect a particulate cloud in the surroundings of the surface maintenance machine. In some embodiments, while monitoring the surroundings of the surface maintenance machine, the sensors 170 and/or 180 can detect a particulate cloud, such as particulate cloud 350. In some instances, the sensors can identify the particulate cloud 350 as a particulate cloud. In some instances, the sensors may identify the particulate cloud 350 as an object/obstruction, as discussed herein.

[0066]In some embodiments, the detecting the particulate cloud is while the surface maintenance machine is cleaning near (e.g., adjacent to) an edge/obstacle. In some embodiments, the particulate cloud could be detected using sensors such as sensors 180. In some embodiments, the surface maintenance machine 100 may include additional sensors. In some instances, a sensor such as a multi-echo LIDAR can be used to detect the particulate cloud. In some instances, an additional sensor (such as a dust-immune sensor type (e.g., ultrasonics, a bumper, etc.)) can be added to the machine to differentiate between particulate and an edge/obstacle (and therefore help with the detection of a particulate cloud).

[0067]As discussed herein, the sensors 180 may be more likely to be negatively impacted when the particulate 350 is close to a vertical surface such as edge/obstacle 105. The particulate 350 can be close to edge 105, for example, when the machine 100 is cleaning adjacent to the edge/obstacle 105. Further, a particulate cloud 350 may be more likely to form from side brush 114 during edge cleaning, as that is when the side brush 114 may make contact with the edge 105, thus helping create a particulate cloud 350. Therefore, when the particulate cloud is detected while the surface maintenance machine is cleaning near the edge/obstacle 105, it is likely that the particulate cloud could be caused by the side brush 114 and the edge 105.

[0068]Method 600 can include operation 640 to automatically reduce a rotational speed of the side brush in response to detecting the particulate cloud (in operation 630). The reduction in rotational speed of the side brush can help eliminate the already formed particulate cloud while also helping prevent any additional particulate clouds from forming. In this instance, the rotational speed of the side brush 114 may not be reduced until a particulate cloud is detected. In some instances, the rotational speed of the side brush 114 may not be reduced until it is determined that the surface maintenance machine is edge cleaning, and a particulate cloud is detected. By not reducing the rotational speed of the side brush 114 until (at least) a particulate cloud is detected, the side brush 114 can continue running at a higher rotational speed for a longer period of time (as opposed to reducing the speed as soon as the machine 100 comes close to an edge 105). This can result in higher productivity while cleaning near an edge/obstacle, as the side brush 114 is operated at a higher speed (thus increasing the effectiveness of the side brush 114 and the cleaning) until a particulate cloud is detected. However, while cleaning productivity can increase, the actual formation and detection of the particulate cloud could result in the sensors 180 being affected by the particulate cloud. But by reducing the rotational speed of the side brush 114 as soon as the particulate cloud is detected, the particulate cloud may vanish before it negatively impacts the sensors 180 and/or the negative impact to the sensors 180 may be significantly reduced/mitigated due to the short time the particulate cloud may exist. Further, additional particulate clouds may be prevented from being formed due to the side brush 114 speed reduction, therefore still improving performance of the surface maintenance machine 100 and the sensors 180.

[0069]In some embodiments, method 600 can include an operation (not depicted) to automatically perform a shake back in response to detecting the particulate cloud (in operation 630). As discussed herein, a clogged filter within the vacuum system can cause additional particulate and particulate clouds, which can cause issues for a surface maintenance machine (such as surface maintenance machine 100), particularly during edge cleaning and/or within a close proximity to an obstacle/edge. To help reduce and/or eliminate particulate clouds, once a particulate cloud is detected (in operation 630), a shake back can be triggered/performed to unclog the filter and stop any additional particulate from escaping due to the clogged filter. In some embodiments, automatically performing a shake back includes running the shaker motor (for example, for a number of seconds). Running the shaker motor may shake the filter and dislodge any clogs in the filter. When the shaker motor is run, debris (e.g., the debris causing the clog) falls down into the hopper directly below the filter. In some embodiments, the surface maintenance machine movement is paused (e.g., edge cleaning is paused) while the shake back is performed and movement is resumed once the shake back is completed (e.g., after the shaker motor has been run). In some embodiments, the surface maintenance machine movement is paused and resumed automatically.

[0070]In some embodiments, method 600 can include an operation (not depicted) to automatically reduce the broom speed and/or broom down force (e.g., broom 110). By reducing the broom speed and/or broom down force, the broom may generate less particulate, thus reducing/eliminating the particulate cloud. In some embodiments, the broom speed and/or broom down force is reduced in response to detecting the particulate cloud.

[0071]In some embodiments, method 600 can include an operation (not depicted) to increase voltage of the vacuum fan. In some instances, vacuum fans can include different types of vacuum fans. For example, the vacuum fan can be a hydraulically driven vacuum fan, in some instances. In other instances, the vacuum fan can be a different type of vacuum fan. As discussed herein, increasing the vacuum fan voltage can increase the airflow and/or particulate flow to the cleaning tool chamber and/or the hopper, thus directing particulate (for example, particulate generated by the broom 110) into the hopper and preventing it from escaping. This can prevent/reduce particulate near the sensors 180. In some embodiments, the voltage of the vacuum fan is increased in response to detecting the particulate cloud.

[0072]In some embodiments, as depicted in FIG. 6, method 600 can include operation 645 to determine that the surface maintenance machine is no longer cleaning near, or adjacent to, an edge/obstacle. For instance, a surface maintenance machine (such as machine 100) can stop cleaning along an edge/obstacle (such as edge 105) and start cleaning in an open area without any nearby obstacles. In some instances, determining that the surface maintenance machine is no longer cleaning near an obstacle can include detecting that the edge/obstacle is no longer adjacent to the first side of the surface maintenance machine.

[0073]As discussed herein, in instances where a surface maintenance machine 100 is in an open area without any nearby obstacles, any generated particulate may be less susceptible to clouding near the sensors 180 as there is not an obstacle/edge to block flow of particulate and the particulate may more freely flow throughout the open area (as opposed to clouding near the machine 100 and the sensors 180). Further, side brush 114 may not generate any particulate clouds (or at least significantly smaller particulate clouds/amounts of particulate) as the side brush 114 will not be in contact with the edge 105. Therefore, once the surface maintenance machine 100 is no longer cleaning along an edge 105, the risk of the machine 100 and/or the sensors 180 being negatively impacted by the particulate is much smaller.

[0074]Method 600 can include operation 655 to determine that there is no longer the particulate cloud. When there is no longer a particulate cloud, there is not any particulate clouding near the sensors 180 and/or negatively impacting the sensors 180. In some embodiments, this determination is through monitoring the surroundings of the surface maintenance machine.

[0075]Method 600 can include operation 660 to automatically increase the rotational speed of the side brush. In some embodiments, increasing the rotational speed of the side brush 114 can include returning the side brush 114 to its rotational speed prior to the reduction in operation 640.

[0076]In some embodiments, automatically increasing the rotational speed of the side brush is in response to determining that the surface maintenance machine is not cleaning near and edge/obstacle and/or that an edge/obstacle is no longer adjacent to the first side of the surface maintenance machine. As mentioned herein, once the surface maintenance machine 100 is no longer cleaning along an edge/obstacle 105, the risk of particulate being formed by side brush 114 and/or the sensors 180 being impacted by the particulate is much smaller. Therefore, to increase efficiency and effectiveness of the surface maintenance machine, the rotational speed of the side brush can be increased as soon as it is determined that the surface maintenance machine is not edge cleaning/along an edge 105.

[0077]In some embodiments, automatically increasing the rotational speed of the side brush is in response to determining that there is no longer the particulate cloud. Running the side brush 114 at a higher rotational speed can increase the productivity/effectiveness of the edge cleaning and the side brush 114. Therefore, increasing the rotational speed of the side brush 114 as soon as there is no particulate cloud can allow the side brush 114 to return to a higher rotational speed while edge cleaning. While this may increase the risk of another particulate cloud being formed by the side brush 114 along the edge 105, this risk may be outweighed by the increase in productivity/effectiveness, in some instances.

[0078]Advantages of embodiments disclosed herein include containing particulate and preventing it from interfering with sensor performance. For example, particulate clouds may be reduced and/or prevented from being formed during surface cleaning, especially when near an obstacle, edge, etc. This helps improve surface maintenance machine performance and sensor performance.

[0079]Thus, embodiments of a surface maintenance machine with a side brush speed program for controlling and reducing side brush speed during edge cleaning are disclosed. Although the present invention has been described in considerable detail with reference to certain disclosed embodiments, the disclosed embodiments are presented for purposes of illustration and not limitation and other embodiments of the invention are possible. One skilled in the art will appreciate that various changes, adaptations, and modifications may be made without departing from the spirit of the invention.