Patent Description:
Personal, assistive robots can include complicated articulation and actuation systems, which can cause such robots to be expensive and difficult to use. As a result, such robots may be financially unattainable for users needing assistive robotic devices and may create a reduced user experience when performing objective tasks. Such robots may be large and heavy due to the complicated articulation, which can limit its ability to provide assistive articulation when accessing, reaching, or otherwise interacting with objects in a particular environment.

<CIT> discloses a method with the features of the preamble of claim <NUM>.

Accordingly, there is a need for actuations systems configured to actuate a telescopic structure in a mobile, assistive robot that can support articulation in multiple degrees of freedom. Benefits of such actuation systems can include lower component and manufacturing costs, less complicated designs, ease of deployment in a wider variety of environments, and increased user experience when performing objective tasks.

Traditional actuation systems often include a series of revolute actuated joints configured to provide articulated reach of a robot arm across a workspace. Each actuated joint must support against gravity the full weight of the structure's distal joints, causing a compounding effect where the proximal joints of the actuation system become large, expensive, and unsafe to actuate around people. A telescopic structure that extends horizontally is self-supporting against gravity and therefore uses much smaller, lower cost, and safer actuators to achieve a comparable reach. In addition, having a slender cross section allows it to reach into cluttered environments not accessible to robot arms that employ traditional actuation system.

The actuation system described herein can provide actuation of a telescopic structure included in a mobile, assistive robot or in non-robotic application. The actuation system provided can achieve articulation through a greater number of degrees of freedom and with greater accuracy of exerted actuation forces compared to traditional actuation systems. As a result, the actuation system described here can provide more robust performance completing user-defined tasks.

According to the presently claimed invention, a method for sensing contact between an actuation system and a use environment and actuating the actuation system is provided. The method includes receiving, by a data processor of an actuation system, a first input corresponding to an interaction force exerted upon at least one segment of a plurality of segments of a telescopic structure of the actuation system. The first input includes a first current value supplied to a first actuator of the actuation system at a time the interaction force was exerted on the at least one segment. The method also includes receiving, by the data processor, a second input associated with a maximum interaction force of the at least one segment. The second input includes a second current value. The method further includes receiving, by the data processor, a third input associated with an actuation force to be exerted by the at least one segment. The third input includes a third current value. The method also includes determining, by the data processor, an actuation signal including a fourth current value less than the second current value and less than or equal to the third current value. The fourth current value causes the first actuator to actuate the at least one segment to exert the actuation force. The method further includes providing, by the data processor, the actuation signal to the first actuator.

In an embodiment, the first current value can be received from a winding current sensor of the first actuator. In another embodiment, the interaction force can be received by a force sensor attached to the telescopic structure. In another embodiment, the method can also include operating the first actuator based on the actuation signal.

In another embodiment, the method can also include receiving, by the data processor, a fourth input corresponding to a first length of the telescopic structure at the time the interaction force was exerted upon the at least one segment. The method can further include receiving, by the data processor, a fifth input corresponding to a second length of the telescopic structure associated with an objective length of the telescopic structure. The method can also include determining an updated third current value based on the fourth input and the fifth input. The updated third current value can cause the first actuator to actuate the telescopic structure to achieve the second length.

In another embodiment, the fifth input can be received programmatically or as a user-provided input. In another embodiment, the first length and the second length can be determined via an encoder coupled to the first actuator. In another embodiment, the actuation signal can cause a drive mechanism coupled to the first actuator to rotate in a first direction extending the at least one segment or in a second direction retracting the at least one segment. The second direction can be opposite the first direction. In another embodiment, the second input can be received programmatically or as a user-provided input.

The actuation system described herein can actuate a telescopic structure to extend or retract in regard to an objective task or interaction forces exerted upon the telescopic structure. The telescopic structure can be actuated horizontally for use as a manipulator and can additionally be actuated to travel vertically along a vertical structure, such as a mast. The actuation system can also include a drive chain including multiple inter-connected links conveying data, power, and/or pneumatic cables or lines therein to a distal end of the telescopic structure. The inter-connected links can flex in one direction and can form a rigid arrangement when an actuation force is applied to the drive chain in a different direction. The actuation system can also include a chain cartridge from which the drive chain can extend from or retract into.

The drive chain can be coupled to a drive mechanism of an actuation source, such as an actuator or a motor. The drive chain can be coupled to the actuator via a drive transmission, which can enable simultaneous or independent actuation of the telescopic structure and vertical travel of the telescopic structure along the vertical structure or mast. In this way, the actuation system can access or reach a larger range of target locations associated with an objective task.

The drive chain can carry within it electrical (e.g., power and data) cables and pneumatic lines to the distal end of the telescopic structure. In traditional robot arms, the routing of these cables through revolute joints to the end of the arm is a significant source of complexity and component failure. In the actuation system described herein, the drive chain configuration provides a simple, compact, and robust solution over the traditional systems.

The telescopic structure can be oriented to reach horizontally. As such, the actuator does not have to support static gravitational loads. This allows the actuator to be small and to not require a high ratio gearbox as is often required in traditional actuator systems. By employing a small motor with a low gear ratio gearbox, the effective inertia of the actuation system is kept low. This has the advantage of allowing the winding current of the actuator to be a good approximation of the forces that the telescopic structure applies to the environment. By being sensitive to interaction forces the telescopic structure can be controlled to react safely around people.

Embodiments of actuation system and corresponding methods for actuating a telescopic structure of an actuation system configured within a mobile robot are discussed herein. However, embodiments of the disclosure can be employed to actuate telescopic structures in stationary or mobile applications which do not include a robot without limit.

<FIG> is a diagram illustrating an exemplary embodiment of an actuation system <NUM> configured to actuate a telescopic structure as described herein. As shown in <FIG>, the actuation system <NUM> can include a chain cartridge <NUM>. The chain cartridge <NUM> can include therein a drive chain <NUM>. The drive chain <NUM> can be coupled to a drive mechanism <NUM>. The drive mechanism <NUM> can be coupled to and actuated by an actuator <NUM> powered by a power supply <NUM>. The power supply <NUM> can include a rechargeable power supply or a non-rechargeable power supply. The drive chain <NUM> can be formed from and include inter-connected links <NUM>. The inter-connected links <NUM> can include an open interior space within each inter-connected link to allow one or more cables <NUM> to be conveyed therein.

As further shown in <FIG>, the actuation system <NUM> can also include a telescopic structure <NUM> including two or more segments <NUM>. The segments <NUM> can be configured to extend from and retract into one another to provide horizontal extension and retraction of the telescopic structure <NUM>. The telescopic structure <NUM> can convey the drive chain <NUM> within the segments <NUM>. The drive chain <NUM> can coupled to the distal segment <NUM> located at a distal end <NUM> of the telescopic structure <NUM>. The distal end <NUM> of the telescopic structure <NUM> can be opposite the proximal end <NUM> of the telescopic structure <NUM>. The drive chain <NUM> can be initially received within the telescopic structure <NUM> at the proximal end <NUM> and can couple to a proximal end of the distal segment <NUM>.

In operation, the actuation system <NUM> can actuate to extend or retract the telescopic structure <NUM>. Upon receiving an actuation signal from a controller <NUM> coupled to the actuator <NUM>, the actuator <NUM> can actuate the drive mechanism <NUM>. The drive mechanism <NUM> can rotate in two directions. In a first direction, the drive mechanism <NUM> can rotate to cause the drive chain <NUM> to exit the chain cartridge <NUM> and to pass into the telescopic structure <NUM> at the proximal end <NUM>. Rotation in this first direction can cause the drive chain <NUM> to exert a linear translation force on the distal segment <NUM> to cause the segments <NUM> to extend from within one another. In a second direction, opposite to the first direction, the drive mechanism <NUM> can rotate to cause the drive chain <NUM> to return into the chain cartridge <NUM> and to exit the telescopic structure <NUM> at the proximal end <NUM>.

<FIG> is a diagram illustrating an exemplary embodiment <NUM> of a drive chain <NUM> of the actuation system <NUM> as described herein. The drive chain <NUM> shown in <FIG> can be formed from a plurality of inter-connected links <NUM>. Each link can include an open interior space <NUM> through which one or more cables or lines <NUM> can pass. In some embodiments, the cables/lines <NUM> can include a data cable, a power cable, and/or a pneumatic line supplying data, power, or pneumatic force, respectively, to a manipulation payload coupled to the distal segment <NUM>. As shown in <FIG>, a first cable/line <NUM> and a second cable/line <NUM> can be configured within the drive chain <NUM>. The distal end <NUM> of the drive chain <NUM> can be coupled to the distal segment <NUM> of the telescopic structure <NUM> shown in <FIG>. This connection is illustrated in <FIG> via the dashed line connecting the distal end <NUM> of the drive chain <NUM> to the distal segment <NUM>.

<FIG> is a diagram illustrating an exemplary embodiment <NUM> of a chain cartridge <NUM> of the actuation system <NUM> as described herein. As shown in <FIG>, the chain cartridge <NUM> can be a self-spooling chain cartridge. The self-guided chain cartridge can include a passively rotating pinion <NUM> configured to receive a proximal end <NUM> of the drive chain <NUM>. The self-guided chain cartridge can include one or more curved guide tracks <NUM> formed on an internal surface <NUM> of the self-guided chain cartridge <NUM>. As shown in <FIG>, the one or more cables/lines <NUM> can exist the chain cartridge <NUM> via a slot or opening in the passively rotating pinion <NUM>. In some embodiments, the one or more cables/lines <NUM> can include a service loop or coiling mechanism to reduce damage to or excessive twisting of the cables/lines <NUM> as the passively rotating pinion <NUM> rotates.

In operation, the drive chain <NUM> is withdrawn from within the chain cartridge <NUM> as the actuator <NUM> actuates the drive mechanism <NUM> in a first direction causing the drive chain <NUM> to form a rigid configuration of the inter-connected links <NUM> and to extend from within the chain cartridge <NUM>. Conversely, as the drive chain <NUM> is pushed into the chain cartridge <NUM> due to rotation of the drive mechanism <NUM> in a second direction (opposite to the first direction), the drive chain <NUM> can form a rigid configuration of the inter-connected links <NUM> causing the passively rotating pinion <NUM> to rotate. The curved guide tracks <NUM> can act with rotation of the pinion <NUM> in response to the drive mechanism <NUM> rotation imparting a linear translation force on the inter-connected links <NUM> to cause the drive chain <NUM> to coil upon itself within the chain cartridge <NUM>.

In some embodiments, the chain cartridge <NUM> can be a guided cartridge including one or more spiral shaped tracks for the drive chain <NUM> to slide into. The spiral shaped tracks can include a smooth surface formed from spring steel or plastic. In this embodiment, the proximal end <NUM> of the drive chain <NUM> is not affixed to the chain cartridge <NUM> and is free to travel within the spiral shaped tracks during extension or retraction of the drive chain <NUM> relative to the chain cartridge <NUM>.

<FIG> is a diagram illustrating another exemplary embodiment <NUM> of the chain cartridge <NUM> of the actuation system <NUM> as described herein. As shown in <FIG>, a cut-away view of the chain cartridge <NUM> is provided. The passively rotating pinion <NUM> can be affixed to the internal surface <NUM> of the chain cartridge <NUM> via a fixed pin or a retaining element <NUM>. The passively rotating pinion <NUM> can include a slot <NUM> through which the one or more cables/lines <NUM> can pass from through a wall <NUM> of the chain cartridge <NUM>.

<FIG> is a diagram illustrating an exemplary embodiment <NUM> of the actuation system <NUM> coupled to a base of a mobile robot as described herein. As shown in <FIG>, the actuation system <NUM> shown and described in relation to <FIG> can be coupled to a base <NUM> of a mobile robot <NUM>. In this embodiment, the actuation system <NUM> can further include a vertical mast <NUM> attached to the base <NUM> of the mobile robot <NUM> and a lift carriage <NUM>. The chain cartridge <NUM>, actuator <NUM>, and telescopic structure <NUM> can be attached to the mast <NUM> via the lift carriage <NUM>. The lift carriage <NUM> can translate the chain cartridge <NUM>, actuator <NUM>, and telescopic structure <NUM> vertically along the mast <NUM>. A power supply <NUM> can be included in the base <NUM> and can be coupled to the actuator <NUM>.

<FIG> is a diagram illustrating an exemplary embodiment <NUM> of a lift carriage <NUM> of the actuation system <NUM> as described herein. As shown in <FIG>, the lift carriage <NUM> can include multiple sets of rollers, such as rollers <NUM> and <NUM>. The rollers <NUM> and <NUM> can be coupled to the lift carriage <NUM> and can allow the lift carriage <NUM> to move vertically along the mast <NUM>. In this way, the lift carriage <NUM> can provide vertical positioning of the telescopic structure <NUM> relative to an object or objective task.

<FIG> is a diagram illustrating an exemplary embodiment <NUM> of the lift carriage <NUM> coupled to a second actuator of the actuation system <NUM> as described herein. As shown in <FIG>, the actuation system <NUM> can also include a second actuator <NUM> provided in the base <NUM> of the mobile robot <NUM>. The second actuator <NUM> can be coupled to the lift carriage via a flexible drive element <NUM>, such as timing belt. The flexible drive element <NUM> can be a loop drive structure that is coupled to the lift carriage <NUM>. The second actuator <NUM> can impart a vertical translation force to the left carriage <NUM> to cause the lift carriage <NUM> to travel vertically along the mast <NUM>. In some embodiments, the flexible drive element <NUM> can include a roller chain or a time belt and can convey the vertical translation force from the second actuator <NUM> to the lift carriage <NUM>.

<FIG> is a diagram illustrating an exemplary embodiment <NUM> of a second chain cartridge including a drag chain formed from a second plurality of inter-connected links coupled to the lift carriage <NUM> as described herein. As shown in <FIG>, the actuation system <NUM> can also include a second chain cartridge <NUM> in the base <NUM>. The second chain cartridge <NUM> can include a drag chain <NUM> including second plurality of inter-connected links <NUM> conveying a second one or more cables/lines <NUM> within a second interior space <NUM> of each of the second plurality of inter-connected links <NUM>. The second one or more cables/lines <NUM> can include one or more of a data cable, a power cable, and/or a pneumatic line. As the lift carriage <NUM> is translated vertically along the mast <NUM>, the drag chain <NUM> can wind or spool into the second chain cartridge <NUM> and/or unwind or unspool from within the second chain cartridge <NUM>.

The second chain cartridge <NUM> can also include a curved guide tracks <NUM> formed within the internal surface <NUM> of the second chain cartridge <NUM>. The curved guide tracks <NUM> can guide the drag chain <NUM> when spooling into or unspooling from within the second chain cartridge <NUM>. The second chain cartridge <NUM> can also include a passively-rotating pinion <NUM> coupled to the internal surface <NUM> of the second chain cartridge <NUM>.

In operation, In operation, the drag chain <NUM> is withdrawn from within the second chain cartridge <NUM> as the second actuator <NUM> actuates in a first direction imparting a linear translation force on the lift carriage via the timing belt <NUM> causing the lift carriage <NUM> to ascend upon the mast <NUM>. The drag chain <NUM> is passively withdrawn from within the second chain cartridge <NUM> as the lift carriage <NUM> travels up the mast <NUM>. Conversely, the drag chain <NUM> is pushed into the second chain cartridge <NUM> as the lift carriage <NUM> descends upon the mast <NUM>. The curved guide tracks <NUM> can act with rotation of the pinion <NUM> in response to the second actuator <NUM> imparting a linear translation force on the lift carriage <NUM> via the timing belt <NUM> to cause the lift carriage <NUM> to descend upon the mast so that the drag chain <NUM> spools within the chain cartridge <NUM>.

<FIG> is a diagram illustrating another exemplary embodiment <NUM> of the lift carriage <NUM> of <FIG> as described herein. As shown in <FIG>, the lift carriage <NUM> can include a first portion <NUM> and a second portion <NUM>. The first portion <NUM> and the second portion <NUM> can be detachably coupled to one another so as to surround the mast <NUM>. Each of the first portion <NUM> and the second portion <NUM> can include a plurality of rollers <NUM>, <NUM> configured to aid the lift carriage <NUM> as it translates along the mast <NUM>. In some embodiments, the first portion <NUM> and the second portion <NUM> of the lift carriage <NUM> can include <NUM>, <NUM>, or <NUM> pairs of rollers <NUM>, <NUM>.

As further shown in <FIG>, the lift carriage <NUM> can be coupled to the drag chain <NUM>. The second one or more cables/lines <NUM> can exit the second interior space <NUM> of a distal link <NUM> of the drag chain <NUM> to pass through the lift carriage <NUM>. As shown in <FIG>, the second one or more cables/lines <NUM> pass through the first portion <NUM> of the lift carriage <NUM>, however, in some embodiments, the second one or more cables/lines <NUM> can pass through the second portion <NUM> of the lift carriage <NUM>. The distal link <NUM> of the drag chain <NUM> can couple to an internal guide <NUM> of the lift carriage <NUM>. The internal guide <NUM> can be integrally formed within either of the first portion <NUM> or the second portion <NUM> of the lift carriage <NUM>.

Still referring to <FIG>, the timing belt <NUM> can be secured to the lift carriage <NUM>. For example, the timing belt <NUM> can be secured to the lift carriage via a clamp. The clamp can hold the timing belt <NUM> in place via engagement features configured to engage engagement features (e.g., teeth) of the timing belt <NUM>. The clamp can be loosened from the lift carriage <NUM> via bolts to make it easier to install the timing belt <NUM> or to adjust a position of the lift carriage <NUM> on the timing belt <NUM>.

<FIG> is a diagram illustrating an exemplary embodiment <NUM> of a mast <NUM> of the actuation system <NUM> as described herein. As shown in <FIG>, the mast <NUM> can include a channel <NUM> configured within the mast <NUM>. The channel <NUM> can be formed as a C-shaped channel or a U-shaped channel as shown in <FIG>. A variety of non-limiting channel shapes can envisioned without limitation. The channel <NUM> can guide the drag chain <NUM> linearly within the mast <NUM>. The mast <NUM> can also include a keeper <NUM> to retain the drag chain <NUM> in a rigid linear configuration within the channel <NUM> during retraction into or extension from the second chain cartridge <NUM>. In some embodiments, the keeper <NUM> can include a brush wiper, a rubber gland, a compliant flap or seal, or a spool of metal tape. In some embodiments, the keeper <NUM> can include the flexible drive element <NUM>. For example, the flexible drive element <NUM> can be formed as a loop coupling the second actuator and a pulley coupled atop of the mast <NUM>. Thus, two portions of the flexible drive element <NUM> can be configured to translate within the mast <NUM>, e.g., portions 710A and 710B. In some embodiments, a first portion 710A of the flexible drive element <NUM> can act as the keeper <NUM> to retain the drag chain <NUM> within the channel <NUM>.

<FIG> is a diagram illustrating an exemplary embodiment <NUM> of a drive transmission of the actuation system <NUM> described herein. As shown in <FIG>, the actuator <NUM> and the chain cartridge <NUM> can be located in the base <NUM> of the mobile robot <NUM> and remotely from the drive mechanism <NUM>. The actuator <NUM> can be coupled to the drive mechanism <NUM> via a drive transmission <NUM>. In some embodiments, the actuator <NUM> can be coupled to the drive mechanism <NUM> via a timing belt, a differential belt, a coupled belt, a gearbox, or a chain drive. By locating the actuator <NUM> and the chain cartridge <NUM> remotely from the drive mechanism <NUM>, the overall footprint, size, and weight of the base <NUM> of the mobile robot <NUM> can be reduced.

<FIG> is a diagram illustrating an exemplary embodiment <NUM> of a differential transmission of the actuation system <NUM> as described herein. As shown in <FIG>, in some embodiments, the drive transmission <NUM> can be configured as a differential transmission <NUM>. The differential transmission <NUM> can include a first differential drive belt <NUM> coupling the first actuator and the drive mechanism <NUM>. The differential transmission <NUM> can also include a second differential drive belt <NUM> coupling the second actuator <NUM> and the drive mechanism <NUM>. As the first actuator <NUM> and the second actuator <NUM> actuate the first differential drive belt <NUM> and the second differential drive belt <NUM> together in the same direction relative to each other, the lift carriage <NUM> can travel vertically on the mast <NUM>. Thus, a net linear force is conveyed to the lift carriage <NUM> due to motion of the first differential drive belt <NUM> and the second differential drive belt <NUM> in the same direction relative to each other (e.g., each of the first differential drive belt <NUM> and the second differential drive belt <NUM> traveling upward together or downward together). When the first actuator <NUM> and the second actuator <NUM> actuate the first differential drive belt <NUM> and the second differential drive belt <NUM> together in an opposite direction relative to each other, the telescopic structure <NUM> can extend or retract. As a result, a net torque can be applied to the drive mechanism <NUM> causing the telescopic structure to extend or retract horizontally relative to the base <NUM> (or a surface on which the base <NUM> is located).

<FIG> is a diagram illustrating the drive mechanism <NUM> of the differential transmission of <FIG> as described herein. As shown in <FIG>, the drive mechanism <NUM> can be configured to couple to the first differential drive belt <NUM> and to the second differential drive belt <NUM>. The drive mechanism <NUM> can include a first pulley <NUM> coupling the first differential drive belt <NUM> to the drive mechanism <NUM> and a second pulley <NUM> coupling the second differential drive belt <NUM> to the drive mechanism.

<FIG> is a diagram illustrating an exemplary embodiment <NUM> of a rotary shaft transmission of the actuation system <NUM> as described herein. In some embodiments, the drive transmission <NUM> can be configured as a rotary shaft transmission <NUM>. As shown in <FIG>, the rotary shaft transmission <NUM> can include a rotary drive shaft <NUM> coupling the actuator <NUM> to a right-angled gear box <NUM>. The right-angled gear box <NUM> can travel vertically along the rotary drive shaft <NUM> as the lift carriage translates vertically along the mast <NUM>. The rotary drive shaft <NUM> can have a square-shaped cross-section and can be configured to pass within the lift carriage <NUM>. In this embodiment, vertical translation of the lift carriage <NUM> and horizontal translation of the telescopic structure <NUM> are not coupled to the same drive transmission.

<FIG> is a diagram illustrating an exemplary embodiment <NUM> of a drive chain guide of the actuation system <NUM> as described herein. As shown in <FIG>, the drive mechanism <NUM> can be configured with a drive chain guide <NUM> to retain the drive chain <NUM> radially with respect to the drive mechanism <NUM>. In some embodiments, the drive chain guide <NUM> can include at least one roller located above or below the drive chain <NUM> at an opening of the chain cartridge <NUM> where the drive chain <NUM> extend from or retracts into the chain cartridge <NUM>.

<FIG> is a diagram illustrating an exemplary embodiment <NUM> of a manipulator payload of the actuation system <NUM> as described herein. As shown in <FIG>, the actuation system <NUM> can include a manipulator payload <NUM> coupled to the distal segment <NUM> of the telescopic structure <NUM>. The manipulator payload <NUM> can be configured with respect to an objective task to be performed using the actuation system <NUM>. In some embodiments, the manipulator payload <NUM> can include a third actuator <NUM>, a sensor <NUM>, or a tool <NUM>. The one or more cables/lines <NUM> conveyed within the drive chain <NUM> can exit the distal segment <NUM> of the telescopic structure <NUM> to couple with the manipulator payload <NUM>.

<FIG> is a diagram illustrating an exemplary embodiment <NUM> of an actuator <NUM> coupled to a drive mechanism <NUM> of the actuation system <NUM> as described herein. The actuator <NUM> can coupled to the drive mechanism <NUM> via a spur gear <NUM>. In some embodiments, the actuator <NUM> can be coupled to the drive mechanism <NUM> via a timing belt, a differential belt, a coupled belt, a gearbox, or a chain drive. The drive mechanism <NUM> can include a plurality of engagement features <NUM> to engageably couple the drive chain <NUM> to the drive mechanism <NUM>. In some embodiments, the engagement features <NUM> can include tooth engagement features, cog engagement features, or friction rollers.

<FIG> is a diagram illustrating an exemplary embodiment <NUM> of a plurality of segments <NUM> of a telescopic structure <NUM> of the actuation system <NUM> as described herein. The telescopic structure <NUM> is shown in <FIG> in a fully retracted configuration such that four segments are nested together. As shown in <FIG>, the plurality of segments <NUM> can include a square-shaped cross-section. In some embodiments, the plurality of segments <NUM> can include a rectangular-shaped cross-section, a circular-shaped cross-section, a curved-shaped cross-section, or a triangular-shaped cross-section. The plurality of segments <NUM> can be formed from injection molded plastic, carbon fiber, extruded aluminum, or ultrasonically welded plastic.

As further shown in <FIG>, each segment of the plurality of segments <NUM> can include an outer cuff <NUM> attached to a distal end <NUM> of the segment. The proximal segment <NUM> of the telescopic structure <NUM> can include an arm attachment feature <NUM>. The arm attachment feature <NUM> can be bonded or similarly affixed to the proximal segment <NUM>. The arm attachment feature <NUM> can be received within the lift carriage <NUM>. The distal segment <NUM> can include an manipulator payload attachment feature <NUM> that can be bonded or similarly affixed to the distal segment <NUM> and configured to couple the distal segment <NUM> to the manipulator payload <NUM> shown in <FIG>.

<FIG> is a diagram illustrating an exemplary embodiment <NUM> a plurality of rollers of the telescopic structure <NUM> of the actuation system <NUM> as described herein. As shown in <FIG>, the telescopic structure can be formed as a plurality of segments <NUM> in a nested arrangement of individual segments, which can extend or retract from one another along a telescopic axis <NUM>. The telescopic structure <NUM> can translate telescopically in a smooth manner with low friction while supporting a payload, and while providing sufficient rigidity so as not to droop or sag when extended.

As shown in <FIG>, an outer cuff <NUM> can be affixed to a distal end <NUM> of a segment. The outer cuff <NUM> can include one or more cylindrical outer cuff rollers <NUM>. The outer cuff rollers <NUM> can be coupled to the outer cuff <NUM> via a pin <NUM> passing through the cylindrical outer cuff roller <NUM> and secured within the outer cuff <NUM>. The outer cuff rollers <NUM> of a first segment can maintain sufficient contact force with an exterior surface of a second segment extending from within the first segment to maintain the telescopic structure <NUM> in a rigid configuration during extension or retraction. As further shown in <FIG>, an inner cuff <NUM> can be positioned in a proximal end <NUM> of each segment. The inner cuff <NUM> can include one or more cylindrical inner cuff rollers <NUM>. The cylindrical inner cuff rollers <NUM> can be coupled to the inner cuff <NUM> via a pin <NUM> passing through the cylindrical inner cuff roller <NUM> and secured within the inner cuff <NUM>. The inner cuff rollers <NUM> of a first segment can maintain sufficient contact force with an interior surface of a second segment from which the first segment extends to further maintain the telescopic structure <NUM> in a rigid configuration during extension or retraction.

The outer cuffs <NUM> and the inner cuffs <NUM> can be formed from a thermally active material. In this way, any undue preloading in the roller caused by inaccurate clearance tolerances can be reduced by heating the up the telescopic structure <NUM> to an activation point of thermally active material. As the preloading relaxes, the rollers <NUM> and <NUM> can set themselves in a low friction position. This can advantageously increase the performance of the contact sensitivity of the telescopic structure <NUM>.

The outer cuff rollers <NUM> and the inner cuff roller <NUM> can be formed from a non-marring material such as engineered plastic and/or carbon fiber. In some embodiments, sliding bushing surfaces can be configured in place of the outer cuff rollers <NUM> and the inner cuff rollers <NUM>.

<FIG> is a diagram illustrating an exemplary embodiment <NUM> of a drive chain guide <NUM> of the telescopic structure <NUM> of the actuation system <NUM> as described herein. The drive chain guide <NUM> can be located in the proximal end <NUM> of each segment of the plurality of segments <NUM>. The drive chain guide <NUM> can guide the drive chain <NUM> along the telescopic axis <NUM> as the drive chain <NUM> is translated within the telescopic structure <NUM>. The drive chain guide <NUM> can constrain the links of the drive chain <NUM> in a linear arrangement and can allow for more efficient transmission of forces from the drive mechanism <NUM> to the distal segment <NUM>. The drive chain guide <NUM> can also reduce buckling of the drive chain <NUM> during retraction of the drive chain <NUM> as the telescopic structure <NUM> retracts from an extended position.

<FIG> is a diagram illustrating an exemplary embodiment <NUM> of an extension limiter <NUM> of the telescopic structure <NUM> of the actuation system <NUM> as described herein. <FIG> is an exploded view of the telescopic structure and relates to a fully assembled view shown in <FIG>. As shown in <FIG>, the outer cuff <NUM> of the segment <NUM> has been extended away, as shown by dashed lines, from its assembled position on the distal end <NUM> of segment <NUM>. In this way, the outer cuff rollers <NUM> can be seen to abut the extension limiter <NUM>. The outer cuff roller <NUM> and pin <NUM> are secured within the outer cuff <NUM> as described in relation to <FIG>. As shown in <FIG>, the outer cuff roller <NUM> and the pin <NUM> are extended away from the outer cuff <NUM>, as shown by dashed lines.

In the view of the embodiment shown in <FIG>, a first segment <NUM> can extend from within a second segment <NUM>. The extension limiter <NUM> can limit the extension of segment <NUM> from within segment <NUM> as the telescopic structure <NUM> extends away from the mast <NUM>. In some embodiments, one or more of the segments of the plurality of segments <NUM> can include an extension limiter <NUM>. The extension limiter <NUM> can prevent over-extension or hyperextension of a first segment with respect to a second segment. The first segment <NUM> can extend from within the second segment <NUM> until the outer cuff roller <NUM> of the second segment <NUM> contacts the extension limiter <NUM> of the first segment <NUM>. In this way, hyperextension of the telescopic structure <NUM> can be eliminated.

The extension limiter <NUM> can include a thin band of material formed on an external surface of one or more segments <NUM>. In some embodiments, the extension limiter <NUM> can be formed from molded plastic, metal tape, sheet metal, or a portion of the segment itself, such as a protrusion. The extension limiter <NUM> can be affixed or located at a location on a segment to ensure maximal extension of one segment from within another and thus maximal extension of the telescopic structure <NUM>. Locating the extension limiter <NUM> farther away from the distal end <NUM> of a segment or the telescopic structure <NUM> (e.g., close to the proximal end <NUM> of a segment or to the telescopic structure), arm extension can be performed with reduced drooping of the segments <NUM>.

<FIG> is a diagram illustrating an exemplary embodiment of a computing architecture <NUM> configured to actuate the telescopic structure <NUM> of the actuation system <NUM> as described herein. As shown in <FIG>, the actuation system <NUM> can be configured within a mobile robot <NUM>. In some embodiments, the actuation system <NUM> may not be configured within a mobile robot and can be configured in an alternate structure suitable for containing or coupling to the actuation system <NUM>.

The actuation system <NUM> can include a first computing device <NUM> including a data processor <NUM>, a memory <NUM> and a communication interface <NUM>. The memory <NUM> can store non-transitory computer-readable, executable instructions, which when executed by the data processor <NUM>, can cause the data processor to perform actuation of the actuation system <NUM> and/or the mobile robot <NUM>. The data processor <NUM> can be configured with one or more controllers. The controllers can be configured to control one or more operational aspects of the actuation system <NUM>. For example, the data processor <NUM> can be configured to include a current controller <NUM>, a force controller <NUM>, and a position controller <NUM>.

The current controller <NUM> can be configured to generate actuation signals in response to input signals received from the force controller <NUM>. The actuation signals can be provided to the actuator <NUM>. The force controller <NUM> can receive inputs associated with a measured interaction force (Fi), a maximum interaction force (Fm), and a desired/objective output force (Fo). The position controller <NUM> can be configured output the desired or objective output force (Fo) based on inputs of measured and desired/ objective position/location data associated with a position/location of the telescopic structure <NUM>.

The actuation signals can be generated in response to sensor data received by the data processor <NUM> from sensors <NUM>. In some embodiments, the sensors <NUM> can include a force sensor coupled to the telescopic structure <NUM>. The sensor data can include the measured position/location data and the measured interaction force (Fi). In some embodiments, the sensor data can be received from the sensor <NUM>. In some embodiments, the sensor data can be received from additional sensors, such as additional sensors coupled to the telescopic structure <NUM>, the mobile robot base <NUM>, the mobile robot <NUM>, and/or the actuator <NUM>. For example, the sensor data can include data received from the encoder <NUM> and the winding current sensor <NUM> configured with respect to the actuator <NUM>. The encoder <NUM> can generate sensor data based on angular position or motion of a rotating shaft of the actuator <NUM>, such as a shaft coupled to the drive mechanism <NUM>. The winding current sensor <NUM> can generate sensor data based on a winding current of the actuator <NUM>.

The actuator <NUM> can be powered by a power supply <NUM> configured in the base <NUM> of the mobile robot <NUM>. The data processor <NUM> can be communicatively coupled to the actuator <NUM> to provide the actuation signals generated by the current controller <NUM>. The actuator <NUM> can actuate in response to the actuation signals to cause the drive mechanism <NUM> to rotate in a desired direction and at a desired speed. The telescopic structure <NUM> can be mechanically coupled to the actuator <NUM> via the drive mechanism <NUM> and the drive chain <NUM>. Responsive to the actuator <NUM> actuating the drive mechanism <NUM>, the actuation system <NUM> can actuate the lift carriage <NUM>, the telescopic structure <NUM>, and/or the manipulation payload <NUM>.

The first computing device <NUM> can be coupled to a second computing device <NUM> via a data/communication network <NUM>. The second computing device <NUM> can include a data processor <NUM>, a memory <NUM> storing non-transitory computer-readable, executable instructions, a communication interface <NUM>, an input device <NUM>, and a display <NUM> configured to provide a graphical user interface (GUI) <NUM>.

The second computing device <NUM> can be configured to receive user inputs via the input device <NUM> and/or the GUI <NUM>. The user inputs can be processed and transmitted via the communication interface <NUM> to the communication interface <NUM> of the first computing device. Once received, the actuation system <NUM> can be configured to generate an actuation signal responsive to the user inputs causing the actuation system <NUM> and/or the mobile robot <NUM> to actuate. In some embodiments, the input device can include a joystick, a microphone, a stylus, a keyboard, a mouse, or a touchscreen. In some embodiments, the display <NUM> can include a touchscreen display and the GUI <NUM> can display sensor data and receive user inputs associated with the sensor data via the GUI <NUM>. The user inputs can be provided to generate actuation signals to cause the actuation system <NUM> to actuate and/or perform an objective task.

It is advantageous that the mobile robot <NUM> and/or the actuation system <NUM> sense and respond to contact, possibly inadvertently, between the mobile robot <NUM> and/or the actuation system <NUM> and the environment. Measuring motor current can be advantageously used as a proxy to determine interaction forces exerted upon the mobile robot <NUM> and/or the actuation system <NUM>. An efficient gear train, such as the mechanical coupling of the actuator <NUM> and the telescopic structure <NUM> via the drive mechanism <NUM> and the drive chain <NUM> of the actuation system <NUM>, can enable interaction force to result in actuator current changes, with a greater degree of sensitivity than inefficient gear trains of traditional actuation systems. Traditional actuation systems can include brushed or rotor-less actuators, which due to the high speed of their operation require higher gear ratios. Actuation systems with lower gear ratios, such as the actuation system <NUM> described herein, can perform better when used in contact sensitive applications where gear rations of less than <NUM>:<NUM> are suitable.

The actuator <NUM> of the actuation system <NUM> can include stepper motors configured with lower gear ratios and closed loop current feedback control for wheels in the base <NUM> of the mobile robot <NUM>, lift carriage <NUM> via actuator <NUM>, and telescopic structure <NUM> via actuator <NUM>. Stepper motors can be configured to generate high torque at low speeds, allowing lower gear ratio transmissions or gear trains to be used. The actuation system <NUM> can control coil current of the actuator <NUM> based on feedback associated with a rotor position of the actuator <NUM>. The rotor position can be measured via a Hall effect sensor and a magnet mounted to the actuator <NUM>. The closed loop current feedback control allows instantaneous actuator current to be determined. In some embodiments, the closed loop current feedback control can be implemented by a position and/or velocity control loop of the actuator <NUM> using a proportional-integral-derivative (PID) control loop mechanism.

An algorithm, implemented in non-transitory, computer-readable, executable instructions and stored in memory <NUM> can be used in the actuation system <NUM>. The algorithm can apply low pass filters to the current signal and can determine if the current of the actuator <NUM> exceeds a threshold value stored in the memory <NUM>. The current of the actuator <NUM> can vary in a positive or negative values from the threshold value. Traditional actuation systems can include more complex current feedback control algorithms, however, it can be advantageous to generate a binary signal from the closed loop current feedback control algorithm which is a more reliable signal that interaction forces exerted on the actuation system <NUM> have exceed threshold values. The binary signal can trigger new controller behavior, such as stopping, going into safety mode, or reversing direction. This ability to trigger new behaviors based on interaction forces can allow the actuation system <NUM> and/or the mobile robot <NUM> to exhibit intelligent behavior when working in unstructured environments and/or in the proximity of humans.

<FIG> is a data flow diagram illustrating an exemplary embodiment <NUM> of actuation signal generation of the actuation system <NUM> as described herein. As shown in <FIG>, a measured interaction force (Fi) can be transmitted through the telescopic structure <NUM> to the actuator <NUM>. The position controller <NUM> can receive a measured length (X) of the telescopic structure <NUM> from the encoder <NUM>. The measured length (X) can be received from the encoder <NUM> at the time the interaction force (Fi) was exerted upon the telescopic structure <NUM> and a desired or objective length (Xd) of the telescopic structure <NUM> stored in memory <NUM>. The position controller <NUM> can generate a desired force output (Fo) associated with a desired winding current value to provide to the force controller <NUM> as an input. The force controller <NUM> can further receive a measured interaction force (Fi) from force sensor <NUM> and a maximum interaction force (Fm) stored in memory <NUM>. The force controller <NUM> can process the current winding current value, the measured length (X), and their derivatives to provide an input to the current controller <NUM>. The current controller <NUM> can then determine an actuation signal relevant to the measured interaction force (Fi) and can transmit the actuation signal to actuator <NUM> and/or <NUM>.

<FIG> is a process flow diagram illustrating an exemplary embodiment of a method <NUM> for actuating a telescopic structure <NUM> of the actuation system <NUM> as described herein. In operation <NUM>, a first signal input can be received by a data processor, such as data processor <NUM>. The first signal input can correspond to an interaction force (Fi) exerted upon at least one segment of a plurality of segments <NUM> of a telescopic structure <NUM>. For example, the interaction force (Fi) can be received by a force sensor <NUM> coupled to the telescopic structure <NUM>. The first input can include a first current value supplied to a first actuator <NUM> of the actuation system <NUM> at a time the interaction force (Fi) was exerted upon the at least one segment. In some embodiments, the first current value can be received by a winding current sensor <NUM> of the first actuator <NUM>.

In operation <NUM>, the data processor <NUM> can receive a second input signal associated with a maximum interaction force (Fm) of the at least one segment. The second current input can include a second current value. In some embodiments, the second input can be received programmatically, such as via memory <NUM>, or via user-provided input, such as via the second computing device <NUM>.

In operation <NUM>, the data processor <NUM> can receive a third input signal associated with an actuation force (Fo) to be exerted by the at least one segment. The third input can include a third current value.

In operation <NUM>, the data processor <NUM> can determine an actuation signal including a fourth current value. The fourth current value can be determined to be less than the second current value and less than or equal to the third current value. The fourth current value can cause the first actuator <NUM> to actuate the at least one segment to exert the actuation force (Fo). In some embodiments, the fourth current value can be a positive current value. In some embodiments, the fourth current value can be a negative current value.

In operation <NUM>, the data processor <NUM> can provide the actuation signal to the first actuator. In some embodiments, the method can further include operating the first actuator based on the actuation signal. In some embodiments, the actuation signal can cause the drive mechanism <NUM> coupled to the first actuator <NUM> to rotate in a first direction extending the at least one segment or in a second direction, opposite to the first direction, retracing the at least one segment.

<FIG> is a process flow diagram illustrating an exemplary embodiment of a method <NUM> for determining an actuation signal for actuating a telescopic structure <NUM> of the actuation system <NUM> as described herein. In operation <NUM>, the data processor <NUM> can receive a fourth input corresponding to a first length (X) of the telescopic structure <NUM> at the time the interaction force (Fi) was exerted upon the at least one segment.

In operation <NUM>, the data processor <NUM> can receive a fifth input corresponding to a second length (Xd) of the telescopic structure <NUM> associated with an objective or desired length of the telescopic structure <NUM>. In some embodiments, the fifth input can be received programmatically, such as via memory <NUM>, or via user-provided input, such as via the second computing device <NUM>. In some embodiments, the first length (X) and/or the second length (Xd) can be determined via an encoder <NUM> coupled to the first actuator <NUM>. In some embodiments, the actuation signal can cause the first actuator <NUM> to actuate the telescopic structure <NUM> to achieve the second length (Xd).

In operation <NUM>, the data processor <NUM> can determine an updated third current value based on the fourth input and the fifth input. The updated third current value can cause the actuator <NUM> to actuate the telescopic structure <NUM> to achieve the second length (Xd).

Exemplary technical effects of the, systems and methods described herein include, by way of non-limiting example, an improved actuation system providing increased contact sensitivity in three cartesian planes and rotational directions in response to interaction forces exerted upon the actuation system. The systems and methods described herein further provide closed loop current control of actuators with low gear ratios to provide reliable and efficient actuation responses to the interaction forces.

Certain exemplary embodiments have been described to provide an overall understanding of the principles of the structure, function, manufacture, and use of the systems, devices, and methods disclosed herein. One or more examples of these embodiments have been illustrated in the accompanying drawings. Those skilled in the art will understand that the systems, devices, and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments and that the scope of the present invention is defined solely by the claims. The features illustrated or described in connection with one exemplary embodiment may be combined with the features of other embodiments. Such modifications and variations are intended to be included within the scope of the present invention.

One skilled in the art will appreciate further features and advantages of the invention based on the above-described embodiments. Accordingly, the present application is not to be limited by what has been particularly shown and described, except as indicated by the appended claims. All publications and references cited herein are expressly incorporated by reference in their entirety.

An actuation system comprises a first chain cartridge including a drive chain engageably coupled to a drive mechanism actuated by a first actuator coupled to a power supply, the drive chain including a first plurality of inter-connected links conveying at least one first cable within a first interior space of each of the first plurality of inter-connected links; and a telescopic structure including a plurality of segments configured to extend and retract telescopically with respect to one another and conveying the drive chain therein. A first end of the drive chain is coupled to a distal segment of the plurality of segments, the distal segment located at a first end of the telescopic structure. The drive mechanism imparts a linear translation force on the first plurality of interconnected links to cause the distal segment to extend from or retract into the first end of the telescopic structure.

Optionally, rotation of the drive mechanism in a first direction causes the drive chain to extend from within the first chain cartridge so as to actuate an extension of the telescopic structure and rotation of the drive mechanism in a second direction causes the drive chain to retract into the first chain cartridge so as to cause a retraction of the telescopic structure.

Optionally, the at least one first cable includes a data cable, a power cable, or a pneumatic line.

Optionally, the first chain cartridge is a self-spooling chain cartridge including a passively rotating pinion coupled to a second end of the drive chain and one or more curved guide tracks formed on an internal surface of the self-spooling chain cartridge, wherein motion of the drive mechanism causes the drive chain to spool into and unspool from the first chain cartridge.

Optionally, the passively rotating pinion is affixed to the internal surface of the self-spooling chain cartridge via a retaining element and includes a slot where the first plurality of cables exit the self-spooling chain cartridge.

Optionally, the actuation system is coupled to a base of a mobile robot, the actuation system further comprising a mast attached to the base of the mobile robot and a lift carriage coupled to the mast, the lift carriage including a plurality of lift carriage rollers, wherein the lift carriage and the telescoping structure translates vertically on the mast.

Optionally, the actuation system further comprises a second actuator in the base, the second actuator coupled to the lift carriage via at least one of a timing belt, a roller chain, or a flexible drive element, wherein the second actuator imparts vertical motion on the lift carriage.

Optionally, the actuation system further comprises a second chain cartridge in the base, the second chain cartridge including a drag chain including a second plurality of inter-connected links coupled to the lift carriage and conveying at least one second cable within a second interior space of each of the second plurality of inter-connected links, wherein vertical motion of the lift carriage causes the drag chain to spool into and unspool from the second chain cartridge.

Optionally, the at least one second cable includes a data cable, a power cable, or a pneumatic line.

Optionally, the mast includes a channel guiding the drag chain linearly within the mast and a keeper retaining the drag chain in a rigid linear arrangement within the channel during retraction into or extension from the second chain cartridge, wherein the keeper includes at least one of a brush wiper, a rubber gland, a compliant flap or seal, a spool of metal tape, or a flexible drive element of the lift carriage.

Optionally, the first actuator and first chain cartridge are located remotely from the drive mechanism in the base of the mobile robot, the first actuator coupled to the drive mechanism via a drive transmission.

Optionally, the drive transmission includes a differential transmission including a first differential drive belt coupling the first actuator to the drive mechanism and a second differential drive belt coupling the second actuator to the drive mechanism, wherein concurrent motion of the first differential drive belt and the second differential drive belt in a first direction or a second direction causes the lift carriage to translate vertically on the mast, and wherein motion of the first differential drive belt in the first direction occurring concurrently with motion of the second differential drive belt in the second direction causes the telescopic structure to translate horizontally relative to a surface on which the base of the mobile robot is located, the first direction opposite the second direction.

Optionally, the drive transmission includes a rotary shaft transmission including a rotary drive shaft and a right-angled gear box coupling the first actuator to the drive shaft, wherein the right-angled gear box travels along the rotary drive shaft as the lift carriage travels vertically on the mast.

Optionally, the drive mechanism includes a drive chain guide retaining the drive chain radially with respect to the drive mechanism.

Optionally, the distal segment of the telescopic structure is coupled to at least one manipulator payload, wherein the at least one manipulator payload includes a sensor, a tool, or a third actuator, and wherein the at least one first cable couples to the manipulator payload.

Optionally, the first actuator is coupled to the drive mechanism via at least one of a timing belt, differential belt, a coupled belt, a gearbox, a spur gear, or a chain drive.

Optionally, the drive chain is engageably coupled to the drive mechanism via a plurality of engagement features of the drive mechanism, the plurality of engagement features including at least one of a plurality of tooth engagement features, a plurality of cog engagement features, or a plurality of friction rollers.

Optionally, each segment of the plurality of segments includes a rectangular-shaped cross-section, a curved-shaped cross-section, or a triangular-shaped cross-section, and wherein the plurality of segments are injection molded plastic segments, carbon fiber segments, extruded aluminum segments, or ultrasonically welded plastic segments.

Optionally, each segment of plurality of segments of the telescopic structure includes a first plurality of rollers coupled to an outer cuff of each segment and a second plurality of rollers coupled to an inner cuff of each segment, the outer cuff located opposite the inner cuff.

Optionally, the inner cuff of each segment includes a drive chain guide inserted into the inner cuff, the drive chain guide including an opening configured to align the first plurality of inter-connected links within the plurality of segments in parallel with a telescopic axis of the telescopic structure along which the plurality of segments telescopically travel.

Claim 1:
A method for sensing contact between an actuation system (<NUM>) and a use environment and actuating the actuation system (<NUM>), the method comprising:
receiving, by a data processor (<NUM>) of an actuation system (<NUM>), a first input corresponding to an interaction force exerted upon at least one segment (<NUM>) of a plurality of segments (<NUM>) of a telescopic structure (<NUM>) of the actuation system (<NUM>) , the first input including a first current value supplied to a first actuator (<NUM>) of the actuation system (<NUM>) at a time the interaction force was exerted upon the at least one segment (<NUM>);
characterised by
receiving, by the data processor (<NUM>), a second input associated with a maximum interaction force of the at least one segment (<NUM>), the second input including a second current value;
receiving, by the data processor (<NUM>), a third input associated with an actuation force (Fo) to be exerted by the at least one segment (<NUM>), the third input including a third current value;
determining, by the data processor (<NUM>), an actuation signal including a fourth current value less than the second current value and less than or equal to the third current value, the fourth current value causing the first actuator (<NUM>) to actuate the at least one segment (<NUM>) to exert the actuation force; and
providing, by the data processor (<NUM>), the actuation signal to the first actuator (<NUM>).