Docking assembly and method for leveling a cart

Abstract

The present disclosure relates to a leveling system for robotic surgical carts 200, featuring a docking assembly 408 that integrates a force sensing element 418, a biasing element 422, and a surface contact element 412 arranged to transmit force for leveling on uneven surfaces. The assembly includes a biasing element cap 420, guide pins 412a, 412b, and a locking plate 414 to ensure precise vertical motion facilitated by an actuation mechanism 402 comprising a motor 404 and actuation shaft 406 with integrated dual Hall feedback sensors. Multiple independently controllable docking assemblies 304a-304d are synchronized to detect initial ground contact and uniformly raise the cart, enhancing stability and surgical accessibility.

Description

DOCKING ASSEMBLY AND METHOD FOR LEVELING A CARTTECHNICAL FIELD

[0001] The present disclosure relates generally to a robotic surgical cart designed for minimally invasive surgical procedures. More specifically, the disclosure relates to an auto-leveling mechanism integrated within the robotic surgical cart, configured to automatically stabilize and maintain the surgical cart’s level during surgical operations conducted on uneven or irregular surfaces.BACKGROUND

[0002] This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described below. This disclosure is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not just as admissions of prior art.

[0003] Robotic surgical systems enable surgeons to remotely control surgical instruments via a surgeon console with precise movements transmitted to effect controlled articulation at the surgical site. However, these systems typically comprise heavy, bulky robotic arms mounted on surgical carts that require significant maneuvering effort and present collision risks during transport near sensitive equipment such as operating tables.

[0004] In surgical environments, uneven or irregular floor surfaces present significant challenges in stabilizing and positioning heavy robotic carts. Existing stabilization approaches rely primarily on manual adjustments or static leveling mechanisms that lack dynamic responsiveness to surface variations and necessitate operator intervention. These conventional systems fail to provide real-time feedback and automatic adjustment capabilities, resulting in vibrations and movements during surgical procedures that compromise surgical precision, patient safety, and sterile environment integrity.

[0005] Accordingly, there is a need for a robotic surgical cart integratedwith an intelligent auto-leveling mechanism incorporating real-time surface adaptation and continuous monitoring capabilities to enhance maneuverability, stability, and safety while addressing the shortcomings of current static and manual leveling systems.SUMMARY

[0006] In an aspect, a docking assembly is provided. The docking assembly comprising a force sensing element, a biasing element, and a surface contact element arranged on each other such that the surface contact element is configured to transmit a force exerted on it to facilitate leveling of a cart on an uneven surface.

[0007] In one or more embodiments, the surface contact element is configured to transmit the force exerted on it towards the biasing element and the force sensing element.

[0008] In one or more embodiments, the surface contact element is configured to transmit the force exerted on it sequentially towards the biasing element and the force sensing element along a linear axis substantially perpendicular to the uneven surface.

[0009] In one or more embodiments, the docking assembly further comprises a biasing element cap configured to encapsulate the biasing element, such that the biasing element remains securely positioned when a force from the surface contact element is exerted on the biasing element.

[0010] In one or more embodiments, when the surface contact element touches the surface, it pushes the biasing element, which in turn pushes the force sensing element, thereby generating a force signal that is transmitted to a control system.

[0011] In one or more embodiments, the docking assembly further comprises a housing having a first hole and a second hole formed in opposing sidewalls thereof, wherein the first hole and the second hole are configured to receive a locking pin for mechanical coupling with an actuation shaft.

[0012] In one or more embodiments, the surface contact element comprises a plurality of guide pins configured to rest on a circumference of a locking plate. The surface contact element further comprises a cavity configured to receive thebiasing element. The surface contact element further comprises a contact element cap extending from an opposite side of the cavity, such that the contact element cap protrudes through a locking plate hole toward the surface.

[0013] In one or more embodiments, the docking assembly further comprises a top side, a bottom side, and a locking plate, wherein the locking plate is secured at the bottom side.

[0014] In one or more embodiments, the bottom side of the docking assembly comprises a first cavity configured to accommodate the force sensing element. The bottom side of the docking assembly further comprises a second cavity including a plurality of guide ways. The plurality of guiding ways is configured to accommodate the plurality of guide pins of the surface contact element such that the plurality of guiding ways facilitate stable vertical motion of the surface contact element during leveling of the cart on the uneven surface.

[0015] In one or more embodiments, the second cavity is larger in diameter than the first cavity.

[0016] In one or more embodiments, the docking assembly further comprises an actuation mechanism configured to move the docking assembly in a vertical direction.

[0017] In one or more embodiments, the actuation mechanism comprises an integrated position feedback sensor configured to detect and provide positional feedback of the docking assembly.

[0018] In one or more embodiments, the actuation mechanism comprises a motor and an actuation shaft.

[0019] In one or more embodiments, the actuation shaft includes a first end and second end, wherein the first end is secured to the actuation mechanism, and the second end is secured to the docking assembly, to move the docking assembly in the vertical direction.

[0020] In one or more embodiments, the second end of the actuation shaft includes a hole at which a locking pin is positioned, the locking pin having a first end and a second end.

[0021] In one or more embodiments, the first end of the locking pin ispositioned in the first hole of the docking assembly, and the second end of the locking pin is positioned in the second hole of the docking assembly, the locking pin being configured to move the docking assembly in the vertical direction.

[0022] In another aspect, a cart is provided. The cart comprises a base portion. The cart further comprises a plurality of wheels mounted to the base portion for mobility of the cart. The cart further comprises a plurality of docking assemblies mounted to the base portion. Each docking assembly comprises a force sensing element, a biasing element and a surface contact element arranged on each other such that the surface contact element is configured to transmit a force exerted on it to facilitate leveling of the cart on an uneven surface.

[0023] In one or more embodiments, the leveling of the cart on the uneven surface comprises the steps of configuring the plurality of docking assemblies to move toward the uneven surface such that the surface contact element, coupled to each docking assembly, approaches the uneven surface; detecting, by a control system communicatively coupled to each force sensing element, which surface contact element first contacts the uneven surface, and halting movement of the corresponding docking assembly; continuing to move the remaining docking assemblies toward the surface until each remaining surface contact element contacts the uneven surface, and halting movement of each corresponding docking assembly upon surface contact to ensure that all docking assemblies are engaged with the surface; and synchronously lifting the cart, including the plurality of wheels, using the docking assemblies to a predefined height so as to uniformly level the cart on the uneven surface.

[0024] In one or more embodiments, the robotic surgical cart further comprising a controller configured to, upon successful completion of the docking sequence and synchronous lifting to the predefined height, the controller transitions into an active monitoring mode in which the controller continuously evaluates, in real time, feedback from the force sensing elements to detect whether contact forces remain within predefined nominal ranges indicative of secure docking, and, in response to feedback from any force sensing element indicating an anomaly comprising a deviation from expected force thresholds due to an obstruction,misalignment, or mechanical interference, the controller initiates a closed-loop corrective response that dynamically adjusts the position or orientation of the affected docking assembly using an actuator mechanism until the measured contact force returns to the predefined nominal range so as to ensure mechanical stability, secure engagement of the docking interface, and maintenance of operational integrity.

[0025] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described earlier, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.BRIEF DESCRIPTION OF THE DRAWINGS

[0026] To further clarify advantages and features of the present disclosure, a more particular description of the disclosure will be rendered by reference to specific embodiments thereof, which are illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the disclosure and are therefore not to be considered limiting of its scope. The disclosure will be described and explained with additional specificity and detail with the accompanying drawings in which:

[0027] FIG. 1 illustrates a schematic diagram representation of a multi-arm teleoperated surgical system configured for minimally invasive robotic-assisted surgery, in accordance with one or more embodiments of the present disclosure.

[0028] FIG. 2 illustrates an example robotic cart assembly, in accordance with one or more embodiments of the present disclosure.

[0029] FIG. 3a illustrates a robotic cart assembly in an undocked position with wheels in contact with the ground and docking assemblies in a retracted position, in accordance with one or more embodiments of the present disclosure.

[0030] FIG. 3b illustrates a robotic cart assembly in a docked position with docking assemblies extended and wheels lifted above ground surface, in accordance with one or more embodiments of the present disclosure.

[0031] FIG. 4a illustrates an isolated view of a docking assembly in the docked position showing actuator extension, in accordance with one or moreembodiments of the present disclosure.

[0032] FIG. 4b illustrates an isolated view of the docking assembly in the undocked position showing actuator retraction, in accordance with one or more embodiments of the present disclosure.

[0033] FIG. 4c illustrates a transparent view of the docking assembly showing internal components including an actuator shaft and its connection mechanisms, in accordance with one or more embodiments of the present disclosure.

[0034] FIG. 4d illustrates a transparent isolated view of the docking assembly, in accordance with one or more embodiments of the present disclosure.

[0035] FIG. 4e illustrates an exploded view of the docking assembly showing all individual components and their assembly relationships, in accordance with one or more embodiments of the present disclosure.

[0036] FIG. 5a illustrates an isolated view of the docking assembly, in accordance with one or more embodiments of the present disclosure.

[0037] FIG. 5b illustrates an exploded view of a docking assembly showing internal components in their assembly arrangement, in accordance with one or more embodiments of the present disclosure.

[0038] FIG. 5c illustrates another exploded view of the docking assembly from a different angle providing an alternative perspective of internal component arrangement, in accordance with one or more embodiments of the present disclosure.

[0039] FIG. 6 illustrates a schematic and logical flow representation of a control system architecture associated with the docking and auto-leveling assembly of the robotic surgical cart.DETAILED DESCRIPTION OF DISCLOSURE

[0040] For the purpose of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the disclosure isthereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the disclosure as illustrated therein being contemplated as would normally occur to one skilled in the art to which the disclosure relates.

[0041] It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the disclosure and are not intended to be restrictive thereof. Throughout the patent specification, a convention employed is that in the appended drawings, like numerals denote like components.

[0042] Reference throughout this specification to “an embodiment”, “another embodiment”, “an implementation”, “another implementation” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Thus, appearances of the phrase “in an embodiment”, “in another embodiment”, “in one implementation”, “in another implementation”, and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.

[0043] The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such process or method. Similarly, one or more devices or sub-systems or elements or structures proceeded by "comprises... a" does not, without more constraints, preclude the existence of other devices or other sub-systems or other elements or other structures or additional devices or additional sub-systems or additional elements or additional structures.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs. The apparatus, system, and examples provided herein are illustrative only and not intended to be limiting.

[0045] The terms “a” and “an” herein do not denote a limitation of quantity,but rather denote the presence of at least one of the referenced items. Further, the term sterile barrier and sterile adapter denotes the same meaning and may be used interchangeably throughout the description.

[0046] Embodiments of the disclosure will be described below in detail with reference to the accompanying drawings.

[0047] The strategic arrangement of the robotic arm carts ensures optimal access to the surgical site while maintaining stability through the integrated autoleveling mechanism described herein. Each cart is equipped with the auto-leveling system to ensure consistent positioning and stability regardless of floor surface variations in the operating theater. This integration is particularly critical in multicart configurations where relative positioning accuracy between carts directly impacts surgical precision.

[0048] As illustrated in FIG. 1, a multi -arm teleoperated surgical system 100 is disclosed, configured for minimally invasive robotic-assisted surgery. As used herein, the term “multi -arm teleoperated surgical system” may also be referred to simply as the “surgical system”. These terms are used interchangeably throughout the present disclosure and are intended to refer to the same system unless otherwise specified. The system 100 is specifically engineered to enhance surgical precision, efficiency, and safety through the integration of a patient side robotic arm carts SL, PL, CA, PR, SR, a surgeon command center 106, and a vision cart 116. FIG. 1 provides a schematic depiction of the layout and principal components of the system 100, which collectively enables the execution of the robotic surgical procedures.

[0049] Referring now to the arrangement illustrated in FIG. 1, the surgical system 100 comprises five robotic arms 102a, 102b, 102c, 102d, and 102e strategically positioned around an operating table 104. Each robotic arm cart is modular and tailored to perform specific functions during surgery. The robotic arm 102a is designated as a camera arm cart CA and supports an endoscopic camera C to provide real-time visualization of the surgical site to a surgeon 114 operating from the surgeon command center or surgeon console 106. Accordingly, the remaining robotic arms 102b, 102c, 102d, and 102e are each equipped with surgicalinstruments designed to perform tasks such as cutting, suturing, and tissue manipulation. Notably, this strategic arrangement of the robotic arm carts ensures optimal access to the surgical site, while concurrently preserving an unobstructed workspace.

[0050] Thereafter, the surgeon command center 106 is operatively connected to the robotic arm carts and functions as the centralized control hub for the system 100. As shown, the surgeon command center 106 comprises a primary controller 108, a 2D monitor 110, and a 3D monitor 112. Herein, the primary controller 108 is particularly configured to receive precise input from the surgeon 114, thereby enabling accurate manipulation of the robotic arms and surgical instruments. The 2D monitor 110 acts as a graphical user interface to relay realtime feedback and visualization of the surgical site, while the 3D monitor 112 offers a magnified, three-dimensional view that further enhances surgical precision. Additionally, the vision cart 116 is structured to house the imaging and processing equipment necessary for surgery and also display high-resolution images of the surgical area to the patient side staff 118.

[0051] FIG. 2 illustrates an example robotic surgical cart assembly, in accordance with an embodiment of the present disclosure. The robotic surgical cart 200, which may also be referred to as cart 200 throughout this disclosure, represents any mobile cart system in which automated docking and undocking functionality is required for operational stability. The robotic surgical cart 200 as depicted in FIG. 2 shows a base portion of the cart assembly without a set-up joint, robotic manipulator arm, and related surgical instrument components that would typically be mounted on the upper structure of the robotic surgical cart 200. The robotic surgical cart 200 may also be referred to as a patient-side arm cart or patient-side manipulator cart.

[0052] The robotic surgical cart 200 includes a base portion 202 having a generally rectangular or polygonal footprint configuration, wherein a plurality of wheels 204 (which may also be referred to by reference numerals 302a-302d in FIGS. 3a and 3b, is rotatably mounted to facilitate movement and positioning of the robotic surgical cart 200 within the operating theater environment. As used herein,the plurality of wheels 302a, 302b, 302c, 302d may be collectively referred to as wheels 302. For clarity, the terms plurality of wheels 204, wheels 302a, 302b, 302c, 302d, and wheels 302 are used interchangeably throughout the present disclosure. The plurality of wheels 302a-302d, when in contact with the ground surface, represents an undocked or unlocked operational state of the robotic surgical cart 200 suitable for transportation and repositioning. Conversely, when the plurality of wheels 302a-302d is not in contact with the ground surface due to elevation by the docking assemblies, this represents a docked or locked operational state of the robotic surgical cart 200 suitable for surgical procedures requiring absolute stability.

[0053] The plurality of wheels 302a-302d may be configured as swivel casters, fixed-orientation wheels, or a combination thereof to facilitate omnidirectional or constrained movement of the robotic surgical cart 200 from one location to another by manual application of force to a handle 208 or through powered propulsion mechanisms. For example, during surgical setup procedures, the robotic surgical cart 200 may be required to be precisely positioned around a surgical table in specific spatial relationships and approach angles based on the anatomical target and surgical procedure requirements, as illustrated in the multicart arrangement shown in FIG. 1. Furthermore, the robotic surgical cart 200 may require transportation between different operating theaters, storage areas, or maintenance facilities within a healthcare institution.

[0054] The robotic surgical cart 200 incorporates a plurality of interface elements including buttons 210, 212 and a control dashboard 214 for providing user interface functionality to control various operational modes, configurations, and adjustments of the robotic surgical cart 200.

[0055] Referring to FIG. 2, during the docked or locked operational state of the robotic surgical cart 200, a plurality of docking assemblies 206 (which may also be referred to by reference numerals 304a-304d in FIG. 3b, and individually referenced as 408 from FIG. 4a onward) is configured to extend and protrude vertically downward from mounting locations near the four corners of the base portion 202 of the robotic surgical cart 200. As used herein, the plurality of dockingassemblies 304a, 304b, 304c, 304d may be collectively referred to as docking assembly 304 or docking assemblies 304. For clarity, the terms plurality of docking assemblies 206, docking assemblies 304a-304d, and docking assemblies 304 are used interchangeably throughout the present disclosure. The extension of these docking assemblies 304a-304d results in lifting the entire robotic surgical cart 200, including the plurality of wheels 302a-302d, vertically upward from the ground surface so as to secure the robotic surgical cart 200 with absolute mechanical stability during surgical procedures where even minute vibrations or movements could compromise surgical outcomes. The deployment and ground contact of the docking assemblies 304a-304d defines the docked or locked operational state of the robotic surgical cart 200. Significantly, each docking assembly 304a, 304b, 304c, 304d from the plurality of docking assemblies 304a-304d is independently controllable and adjustable to achieve precise leveling of the robotic surgical cart 200 even when positioned on an uneven, irregular, or sloped surface.

[0056] In alternative embodiments, the uneven surface may comprise various configurations including a ground floor surface, a ceiling-mounted surface in inverted cart configurations, or a side wall-mounted surface in specialized vertical mounting arrangements, depending on the specific application requirements and mechanical design of the cart 200. Regardless of the cart orientation or mounting configuration, the force transmission path through the docking assembly 408 is oriented along a linear axis that is substantially perpendicular to the uneven surface, such that forces exerted on the surface contact element 412 are transmitted sequentially through a biasing element 422 (as shown in FIGS. 4e, 5b, 5c) to the force sensing element 418 (as shown in FIGS. 4e, 5b, 5c) along this perpendicular axis. In configurations where the cart 200 is mounted on a horizontal ground surface, this linear axis corresponds to a vertical direction. In configurations where the cart 200 is mounted on a ceiling surface or wall surface, the linear axis remains perpendicular to that mounting surface, which may correspond to a downward vertical direction, an upward vertical direction, or a horizontal direction respectively.

[0057] The robotic surgical cart 200 further comprises a control system 600configured to govern the docking and auto-leveling operation of the robotic surgical cart 200. FIG. 6 illustrates a schematic representation of the control system architecture associated with the docking and leveling assembly of the robotic surgical cart. In particular, FIG. 6 demonstrates the functional interrelationship between a plurality of docking assemblies 304a-304d, each equipped with the force sensing element 418 and the actuation mechanism 402, and a central processor 602 configured to execute closed-loop feedback control algorithms for leveling the cart 200 on an uneven or irregular surface. The control system 602 represented in FIG. 6 operates in conjunction with the structural elements detailed in FIGS. 1 through 5c.

[0058] In one or more embodiments, the central processor 602 may be a microcontroller, microprocessor, or processing unit that is communicatively coupled with the force sensing elements 418 integrated within each docking assembly 304a-304d, wherein the force sensing element 418 transmits force data corresponding to the contact pressure between the surface contact element 412 of the docking assembly 304 and the ground surface. These real-time force signals are processed by the processor to determine the contact condition of each docking assembly 304a-304d and to execute corrective commands for precise height adjustment and stabilization.

[0059] In one or more embodiments, the control system 602 may be implemented using various computational platforms including but not limited to embedded microcontrollers such as ARM Cortex processors, programmable logic controllers (PLCs), field-programmable gate arrays (FPGAs), distributed processing systems, or dedicated embedded processors with real-time operating system capabilities.

[0060] The control system 602 is specifically configured to continuously receive electrical signals from the force sensing elements 418 positioned within each docking assembly 408. These electrical signals are digitized through analog- to-digital converters and continuously analyzed in real-time using signal processing algorithms to detect force variations, force distribution patterns, and force magnitude changes across the plurality of docking assemblies 304a-304d. Based onthis continuous analysis, the control system 602 executes a closed-loop feedback control algorithm, which may be implemented as a proportional-integral-derivative (PID) controller, fuzzy logic controller, adaptive controller, fault detection module, or state-space controller, to independently adjust each actuation mechanism 402 (as shown in FIGS. 4a-4c, 4e) in real-time with update rates that may range from 10 Hz to 1000 Hz depending on system response requirements.

[0061] The PID controller 604 is configured to provide precise positional and force regulation by continuously comparing the actual feedback signals received from the force sensing elements 418 with pre-defined reference values and generating corresponding correction signals to the actuation mechanisms 402 for accurate adjustment. The adaptive control module 606 dynamically modifies the control parameters in real time to compensate for variations arising from surface irregularities, changes in load distribution caused by the movement of robotic arms mounted on the cart 200, or external disturbances encountered during surgical operations. Herein, the adaptive control module 606 may be executed by one or more processors configured to analyze feedback data, adjust control coefficients, and implement real-time parameter tuning to ensure smooth, responsive, and stable operation of the leveling system under dynamic conditions. The fault detection module 608 is further configured to continuously monitor the health and performance of the sensors, actuators, and communication interfaces, thereby detecting anomalies such as excessive deviation in force readings, signal loss, sensor malfunction, or actuator obstruction. Upon detection of such anomalies, the fault detection module 608 initiates predefined safety responses including halting actuator movement, recalibrating sensor outputs, or generating system alerts to prevent instability or mechanical failure. Herein, the fault detection module 608 may be executed by one or more processors configured to monitor, analyze, and evaluate operational parameters of the docking assemblies and associated components in real time, execute diagnostic algorithms to isolate the cause of the fault, and initiate corrective or protective actions to ensure safe and reliable operation of the control system 602.

[0062] The control logic is programmed to ensure that uneven surfaceconditions are automatically compensated through micro-adjustments in actuation mechanism extension or retraction, typically with positional resolution in the range of 0.01 mm to 1 mm, thereby maintaining a precisely level platform orientation throughout surgical procedures that may extend over several hours. In the present context, the term “control logic” refers to the programmed algorithms and decisionmaking processes embedded within the central processor 604 that govern operation of the docking and leveling assembly. It processes real-time feedback from the force sensing elements to command the actuators for precise micro-adjustments, ensuring the cart remains level on uneven surfaces. The control logic also incorporates safety and fault detection routines to identify anomalies and initiate corrective or protective actions for stable and reliable operation. The control system 602 further implements multiple safety functions including an emergency stop function, which may be triggered by detection of abnormal force readings exceeding predetermined thresholds, system mechanical overload detection indicating potential component failure, sensor malfunction detection, communication loss detection, or manual activation of a physical emergency stop switch by the operator.

[0063] When the emergency stop function is triggered through any of these mechanisms, all actuation mechanism 402 movements across all docking assemblies 304a-304d are halted immediately and simultaneously to prevent potential equipment damage, cart instability, or safety hazards. Additionally, the control system 602 is programmed to provide continuous monitoring of cart positioning and orientation during ongoing surgical procedures, making automatic corrective micro-adjustments as needed in response to detected variations to maintain absolute stability over extended operating periods, even in the presence of dynamic loading conditions created by robotic arm movements during surgical maneuvers.

[0064] Referring to FIGS. 3a and 3b, which illustrate the base portion 202 of the robotic surgical cart 200 in an undocked operational state (as shown in FIG. 3a) and a docked operational state (as shown in FIG. 3b), the structural arrangement of the leveling system components is clearly depicted. The base portion 202 includes the plurality of docking assemblies 304a, 304b, 304c, 304d (individuallyreferred to by reference numeral 408 from FIG. 4a onward) configured and mounted at or near the four corners of the base portion 202 of the robotic surgical cart 200, thereby providing a quadrilateral support base with balanced load distribution. Furthermore, the plurality of wheels 302a, 302b, 302c, 302d is also configured proximate to the corners of the base portion 202 of the robotic surgical cart 200, typically positioned radially inward from the docking assemblies to allow clearance for docking assembly extension.

[0065] The specific number of docking assemblies 304a, 304b, 304c, 304d and wheels 302a, 302b, 302c, 302d, as well as the geometric placement of the docking assemblies 304a, 304b, 304c, 304d and wheels 302a, 302b, 302c, 302d as shown in FIGS. 3a and 3b, are provided for illustrative purposes. However, based on specific design requirements, load capacity specifications, cart footprint dimensions, or stability requirements, the number of docking assemblies and wheels, as well as the spatial placement and geometric distribution of the docking assemblies and wheels, may vary. Alternative embodiments may include three docking assemblies arranged in a triangular pattern, five or more docking assemblies arranged in polygonal configurations, or non-symmetrical arrangements optimized for specific load distribution patterns.

[0066] According to an embodiment, the docking assemblies 304a, 304b, 304c, 304d are specifically configured to provide automatic leveling functionality for the robotic surgical cart 200 in situations where an uneven, irregular, or sloped surface is encountered during the docking operational state of the robotic surgical cart 200. During surgical procedures, the robotic surgical cart 200 must be docked or locked to the ground surface without any residual movement, oscillation, or vibration that could compromise surgical precision. In many real-world scenarios, the floor surface of the operating theater may exhibit uneven characteristics due to flooring material variations, structural settling, tile height variations, presence of floor-mounted equipment interfaces, cable management systems, or cleaning residue accumulation. Such surface irregularities can prevent the robotic surgical cart 200 from being evenly placed in a level orientation, potentially causing the robotic surgical cart 200 to exhibit shaking, rocking, or vibration when the roboticarms execute movements during surgical procedures, which can adversely affect instrument positioning accuracy and surgical outcomes.

[0067] The docking assemblies 304a, 304b, 304c, 304d are engineered and configured such that they automatically adjust their vertical extension heights independently based on the localized surface characteristics and elevation of the ground surface directly beneath each docking assembly to provide absolute stability and precise level orientation of the robotic surgical cart 200 during surgical procedures. Each docking assembly 304a, 304b, 304c, 304d from the plurality of the carts 200 is independently controllable through the control system 602 to achieve precise leveling of the robotic surgical cart 200 on uneven surfaces such as irregular ground floors, sloped surfaces, or surfaces with localized elevation variations.

[0068] The docking assemblies 304a, 304b, 304c, 304d are configured to translate vertically inward (retraction) and outward (extension) along their longitudinal axes and to automatically adjust their extension heights during the docking sequence of the robotic surgical cart 200 based on real-time force feedback from the integrated force sensing elements 418.

[0069] Referring now to FIGS. 4a through 4e, an isolated and detailed view of the docking assembly 304 of FIGS. 3a and 3b is shown, which is hereinafter referred to by reference numeral 408 for consistency. To achieve the automatic leveling functionality of the robotic surgical cart 200, all of the docking assemblies 304a-304d participate cooperatively in a coordinated manner. However, for clarity and ease of technical understanding, only one representative docking assembly 408 is described in detail herein for illustration purposes, with the understanding that the other docking assemblies 304b, 304c, 304d include substantially the same or similar structural configuration and operational characteristics. In the non-limiting embodiment illustrated, four docking assemblies are employed in a quadrilateral arrangement. However, based on specific design requirements, load distribution considerations, or cart geometry, the number of docking assemblies may vary to include three, five, six, or more docking assemblies arranged in appropriate geometric patterns.

[0070] In an embodiment, the docking assembly 408 includes a top side 408a oriented toward the base portion 202 of the cart 200 and a bottom side 408b oriented toward the ground surface. The docking assembly 408 incorporates several key functional components including the force sensing element 418, a biasing element cap 420, the biasing element 422, a surface contact element 412, and a locking plate 414, all arranged in a vertically stacked configuration relative to each other and mounted at the bottom side 408b of the docking assembly 408. More generally, the force sensing element 418, the biasing element 422, and the surface contact element 412 are arranged in a series or collinear configuration along a linear axis, wherein the linear axis is oriented substantially perpendicular to the surface upon which the cart 200 is to be positioned. This perpendicular orientation ensures that contact forces exerted on the surface contact element 412 by the underlying surface are transmitted sequentially and directly along the linear axis through the biasing element 422 to the force sensing element 418 without significant lateral force components. While the term "vertically stacked" is used throughout this description for convenience when referring to the common configuration where the cart 200 is positioned on a horizontal ground surface, it should be understood that the same structural arrangement and force transmission principles apply when the cart is oriented differently, such that the linear force transmission axis remains perpendicular to the contact surface regardless of whether that axis is oriented vertically, horizontally, or at an angle relative to gravitational vertical depending on the mounting configuration of the cart 200. The locking plate 414 is rigidly secured at the bottom side 408b of the docking assembly 408 through mechanical fasteners, welding, adhesive bonding, or integral formation. This precisely engineered arrangement enables the surgical cart 200 to dynamically adjust its support configuration in real time based on detected ground contact forces, thereby enhancing operational stability, reducing vibration transmission, and eliminating the need for time-consuming manual leveling interventions by operating room personnel.

[0071] In an alternative embodiment, the sequence of the primary leveling components may be rearranged along the linear axis without departing from theprinciples of the present disclosure. For example, the biasing element 422 may be positioned between the force sensing element 418 and the biasing element cap 420, such that force is transmitted from the surface contact element 412 first to the biasing element cap 420, then to the biasing element 422, and finally to the force sensing element 418. In other variations, the force sensing element 418 may be disposed adjacent to the surface contact element 412, with the biasing element 422 and biasing element cap 420 arranged proximally above. These alternative stacking configurations maintain a continuous, substantially linear force transmission path along an axis perpendicular to the contact surface.

[0072] The force sensing element 418 may be implemented using various sensing technologies depending on force measurement range requirements, accuracy specifications, response time requirements, and environmental conditions. In various embodiments, the force sensing element 418 may comprise a load cell utilizing strain gauge technology, wherein mechanical deformation of a metal structure under applied load causes resistance changes in bonded strain gauges that are measured through a Wheatstone bridge circuit. Alternative embodiments may employ piezoelectric force sensors that generate electrical charge proportional to applied mechanical stress through the piezoelectric effect in crystalline materials such as quartz or piezoelectric ceramics. In yet other embodiments, the force sensing element 418 may comprise capacitive force sensors where applied force changes the gap distance between capacitor plates, thereby altering capacitance in a measurable manner. Additional alternative embodiments may utilize piezoresistive sensors fabricated from semiconductor materials exhibiting resistance changes under mechanical stress, or magnetoelastic sensors where applied force changes magnetic properties of ferromagnetic materials. The selection of force sensing technology may be optimized based on factors including measurement range (typically 25N to 250N for this application), resolution requirements, temperature stability, long-term reliability, and cost considerations.

[0073] In an embodiment, the docking assembly 408 further includes the actuation mechanism 402 mechanically coupled to the docking assembly 408. The actuation mechanism 402 comprises a motor 404 and an elongated actuation shaft406 configured for controlled linear extension and retraction. The actuation shaft 406 has a first end 406-1 and an opposite second end 406-2 defining the longitudinal extent of the shaft 406. The first end 406-1 of the actuation shaft 406 is mechanically secured to the actuation mechanism 402, specifically to the motor output shaft or transmission system, while the second end 406-2 of the actuation shaft 406 is mechanically secured to the docking assembly 408 through a connection mechanism to translate the linear motion of the actuation shaft 406 into corresponding vertical movement of the docking assembly 408.

[0074] The actuation mechanism 402 may be implemented using various actuation technologies depending on force capacity requirements, speed specifications, positioning accuracy, and control requirements. In various embodiments, the actuation mechanism 402 may comprise an electric linear actuator incorporating a ball screw mechanism for high efficiency and precision, a lead screw mechanism for cost-effective linear motion generation, or a rack-and- pinion mechanism for robust force transmission. Alternative embodiments may employ pneumatic linear actuators utilizing compressed air to generate linear motion with inherent compliance characteristics, or hydraulic linear actuators utilizing pressurized hydraulic fluid to achieve high force capacities. In yet other embodiments, the actuation mechanism 402 may comprise electromechanical actuators with integrated gear reduction systems, direct-drive linear motors for high-speed positioning without mechanical transmission elements, or telescoping actuators providing extended stroke lengths in compact retracted configurations.

[0075] The motor 404 component of the actuation mechanism 402 may similarly be implemented using various motor technologies depending on torque requirements, speed control characteristics, positioning accuracy, and control system 602 compatibility. In various embodiments, the motor 404 may comprise a stepper motor providing precise incremental positioning without requiring feedback sensors, a servo motor incorporating integrated position feedback for closed-loop control, a brushed or brushless DC motor for efficient and controllable rotation, or a linear motor providing direct linear motion without rotary-to-linear conversion mechanisms.

[0076] According to performance specifications, the actuation mechanism 402 provides a load capacity ranging from 500N to 5000N to support the weight of the robotic surgical cart assembly and to apply sufficient ground contact force for stable docking. The actuation mechanism 402 operates at controlled linear speeds ranging from 5 mm / sec to 50 mm / sec to achieve timely docking and undocking operations without excessive mechanical shock or vibration. In specific embodiments, the actuation mechanism 402 incorporates integrated dual Hall effect feedback sensors (not explicitly shown in the figures) configured to detect and provide precise positional feedback regarding the extension position of the docking assembly 408. The Hall effect sensors utilize magnetic field detection to determine the position of magnetic elements attached to moving components, thereby providing non-contact position sensing with high reliability and minimal wear.

[0077] The actuation mechanism 402 may also incorporate mechanical safety features including overload protection mechanisms such as slip clutches, shear pins, or force-limiting devices that prevent mechanical damage in the event of excessive force application or mechanical obstruction. Additional safety features may include mechanical hard stops defining maximum extension and retraction limits, position limit switches providing electrical signals when travel limits are approached, and thermal protection devices preventing motor overheating during extended operation or stall conditions.

[0078] The docking assembly 408 includes a first hole 410a and a second hole 410b formed through opposing sidewall portions of the docking assembly housing structure. These holes are positioned and dimensioned to accommodate a locking pin 416 that mechanically couples the actuation shaft 406 to the docking assembly 408. The second end 406-2 of the actuation shaft 406 includes a transverse hole 406a formed through the shaft diameter, through which the locking pin 416 is inserted to create a mechanical connection. The locking pin 416 is an elongated cylindrical or prismatic element having a first end 416a and an opposite second end 416b.

[0079] During assembly, the locking pin 416 is inserted such that it passes sequentially through the first hole 410a of the docking assembly 408, then throughthe hole 406a in the actuation shaft 406, and finally through the second hole 410b of the docking assembly 408, thereby mechanically coupling these components in a configuration that allows transmission of axial forces while permitting relative rotational motion if required. The locking pin 416 may be secured in position through various retention mechanisms including, but not limited to, cotter pins inserted through holes in the protruding ends of the locking pin, threaded fasteners engaging threaded portions of the locking pin ends, spring clips engaging grooves in the locking pin, press-fit retention through interference fits, or welded or adhesively bonded permanent attachment.

[0080] This mechanical connection arrangement configured through the locking pin 416 enables the docking assembly 408 to translate vertically in upward and downward directions precisely following and corresponding to the linear motion of the actuation shaft 406 when the actuation shaft is extended or retracted by activation of the actuation mechanism 402. The mechanical coupling provides positive force transmission in both extension and retraction directions while maintaining alignment and preventing lateral displacement.

[0081] Now referring to FIGS. 5a through 5c in conjunction with previously described FIGS. 4a through 4e, the detailed internal components and arrangement of the docking assembly 408 are illustrated. The force sensing element 418, the biasing element cap 420, the biasing element 422, the locking plate 414, and the surface contact element 412 are arranged and assembled within the interior volume of the bottom side 408b of the docking assembly 408 housing structure. The docking assembly 408 at its bottom side 408b includes specifically configured cavities, mounting features, and structural provisions to accommodate and properly position the force sensing element 418, the biasing element cap 420, the biasing element 422, the locking plate 414, and the surface contact element 412 to achieve the automatic leveling mechanism functionality of the robotic surgical cart 200.

[0082] According to an embodiment, the bottom side 408b of the docking assembly 408 comprises a first cavity 424 configured with appropriate dimensions and geometry to accommodate the force sensing element 418, and a second cavity 426 positioned adjacent to or surrounding the first cavity 424 and including aplurality of elongated guideways 426a, 426b (as discussed later in detail). The first cavity 424 is dimensioned to provide a secure mounting location for the force sensing element 418 while allowing necessary electrical connections to the control system 602 and protecting the sensitive sensing components from mechanical damage or contamination. The force sensing element 418 is positioned and secured within the first cavity 424 through mounting brackets, adhesive attachment, mechanical fasteners, or press-fit installation depending on the specific sensor configuration.

[0083] As illustrated, the biasing element cap 420 is positioned in mechanical contact with and biased against the force sensing element 418. The biasing element cap 420 is specifically configured and dimensioned to encapsulate, contain, and constrain the biasing element 422 within its interior volume or engagement features, such that the biasing element 422 remains securely positioned, properly aligned, and constrained from lateral displacement when compressive force from the surface contact element 412 is exerted on the biasing element 422 during ground contact and loading. The biasing element cap 420 may be fabricated from rigid materials including metals such as steel, aluminum, or titanium alloys, or from high-strength engineering plastics such as polyetheretherketone (PEEK), polyamide, or fiber-reinforced composites.

[0084] As illustrated, the biasing element 422 is positioned within the biasing element cap 420 and is configured to apply a controlled biasing force to the force sensing element 418, thereby maintaining mechanical preload and ensuring consistent force transmission characteristics. The biasing element 422 is mechanically positioned and constrained inside the biasing element cap 420, biasing against the force sensing element 418 to create a mechanical force transmission path from the surface contact element 412 through the biasing element 422 to the force sensing element 418.

[0085] The biasing element 422 may be implemented using various elastic or resilient element technologies depending on force-deflection characteristics, stroke requirements, fatigue life, and environmental conditions. In various embodiments, the biasing element 422 may comprise a helical coil springmanufactured from spring steel, stainless steel, or other high -fatigue-resistance alloys providing linear or progressive force-deflection characteristics. Alternative embodiments may employ compression springs in various configurations including cylindrical, conical, or barrel-shaped geometries optimized for specific load and deflection requirements. In yet other embodiments, the biasing element 422 may comprise wave springs providing compact axial height with controlled spring force, Belleville washers or disc springs providing high force capacity in minimal axial space with adjustable force-deflection characteristics through series or parallel stacking arrangements, elastomeric elements manufactured from materials such as natural rubber, polyurethane, silicone, or other elastomers providing damping characteristics and non-linear force response, or pneumatic springs utilizing compressed gas to provide compliant force generation with adjustable stiffness through pressure regulation.

[0086] The selection of biasing element technology and specifications is determined based on required force range, deflection range, response characteristics, fatigue life requirements typically exceeding millions of compression cycles, temperature stability across operating theater temperature ranges, and chemical compatibility with cleaning and sterilization procedures commonly employed in surgical environments.

[0087] The surface contact element 412, also referred to as the surface contact element 412, comprises a plurality of guide pins 412a, 412b that are rigidly attached to or integrally formed with the main body of the surface contact element 412. These guide pins are elongated cylindrical or prismatic protrusions configured to rest on, engage with, or interface with the circumference, inner wall surface, or guiding features of the locking plate 414, and specifically to engage with the guideways 426a, 426b formed in the second cavity 426. The guide pins 412a, 412b provide lateral constraint and alignment guidance for the surface contact element 412 during its vertical translation motion.

[0088] The surface contact element 412 further comprises a cavity 412c configured with appropriate geometry to receive, accommodate, and mechanically interface with the biasing element 422. This cavity is dimensioned to allow partialinsertion of the biasing element 422 such that compressive forces applied to the surface contact element 412 are transmitted to the biasing element 422, causing elastic compression or deflection of the biasing element.

[0089] The surface contact element 412 further comprises a contact element cap 412d, which extends from an opposite side or bottom surface of the cavity 412c, forming a protrusion that extends through and beyond the bottom surface of the contact element 412 main body. The contact element cap 412d is specifically positioned and configured such that it protrudes through a locking plate hole 414a formed in the locking plate 414, thereby extending toward and ultimately contacting the ground surface beneath the robotic surgical cart 200 during docking operations. The contact element cap 412d serves as the primary ground contact interface and may be formed integrally with the surface contact element 412 or may be a separate component attached through threading, press-fitting, welding, or adhesive bonding.

[0090] The plurality of guideways 426a, 426b formed within the second cavity 426 comprises elongated channels, slots, or grooves that are specifically configured and dimensioned to accommodate, receive, and guide the plurality of guide pins 412a, 412b of the surface contact element 412. The guideways 426a, 426b establish a linear bearing interface wherein the guide pins can translate freely in the vertical direction while being constrained from lateral or rotational displacement. This guideway arrangement facilitates stable, aligned, and controlled vertical motion of the surface contact element 412 during the automatic leveling process of the robotic surgical cart 200 on the uneven ground surface, preventing binding, misalignment, or jamming that could compromise leveling accuracy or damage components.

[0091] In one embodiment, the second cavity 426 has a diameter, width, or cross-sectional dimension that is larger than the corresponding diameter, width, or cross-sectional dimension of the first cavity 424. This dimensional relationship allows the second cavity 426 to accommodate both the surface contact element 412 components and the guideways 426a, 426b while the smaller first cavity 424 provides a protected mounting location for the more sensitive force sensing element 418. The surface contact element 412 is mechanically biased through contact withone end of the biasing element 422 such that one end portion of the biasing element 422 fits into, engages with, or seats within the cavity 412c of the surface contact element 412, creating a positive mechanical interface for force transmission.

[0092] The guide pins 412a, 412b rest on, engage with, or slide within the inner circumference, guiding surfaces, or channel walls of the second cavity 426 specifically via the precision-formed guideways 426a, 426b. The locking plate 414 is rigidly secured with the docking assembly 408 housing structure through mechanical fasteners such as screws or bolts, welding, adhesive bonding, or integral formation as a single monolithic structure. The surface contact element cap 412d protrudes through and extends beyond the locking plate hole 414a formed as a circular, polygonal, or custom-shaped aperture in the locking plate 414, thereby positioning the contact surface in proximity to the ground for initial contact during docking sequences.

[0093] According to an embodiment, the force sensing element 418 provides a measurement or load capacity range spanning from 25N to 250N, encompassing the expected range of contact forces that will be encountered during normal leveling operations. This range is selected to provide adequate sensitivity to detect initial ground contact with forces as low as 25N while providing sufficient capacity to measure the higher forces up to 250N that may be experienced when the full weight of the cart is distributed across the docking assemblies. When the surface contact element cap 412d is pressed against the ground surface during the docking operational state of the robotic surgical cart 200, a compressive load within the sensing range is mechanically transferred and transmitted onto the force sensing element 418 sequentially through the mechanical force transmission path comprising the surface contact element cap 412d, the surface contact element 412 body, the biasing element 422, and the biasing element cap 420.

[0094] The force transmission path is characterized by a substantially linear force vector aligned along a longitudinal axis of the docking assembly 408 that extends perpendicular to the surface being contacted. This perpendicular alignment ensures that the predominant force component is directed along the linear axis through the sequential arrangement of components, minimizing off-axis forces andmaximizing measurement accuracy of the force sensing element 418. The guide pins 412a, 412b and guideways 426a, 426b maintain this perpendicular alignment by constraining the surface contact element 412 to translate exclusively along the linear axis without lateral deviation, thereby ensuring that force transmission remains sequential and unidirectional through the biasing element 422 to the force sensing element 418.

[0095] When the surface contact element 412 initially touches and establishes contact with the ground surface, it mechanically pushes against and compresses the biasing element 422, causing elastic deformation or compression of the biasing element. The biasing element 422, in turn, pushes against and applies force to the force sensing element 418 through the intermediate biasing element cap 420, which creates a measurable force signal in the form of an electrical output voltage, current, resistance change, capacitance change, or digital signal depending on the sensing technology employed. This force signal is electrically communicated and transmitted to the control system 602 through electrical wiring, signal conditioning circuits, analog-to-digital converters, and communication interfaces.

[0096] The surface contact element 412 is further specifically configured to detect, sense, or measure the magnitude of force exerted on it by the ground surface during docking operations and to facilitate and enable the automatic leveling process of the robotic surgical cart 200 on an uneven, irregular, or sloped ground surface through the force feedback mechanism.

[0097] According to an embodiment, the actuation mechanism 402 provides a load capacity ranging from 500N to 5000N, encompassing the forces necessary to lift the mass of the robotic surgical cart assembly and to maintain stable ground contact pressure across varying floor conditions and cart loading scenarios. The actuation mechanism 402 operates at controlled linear extension and retraction speeds ranging from 5 mm / sec to 50 mm / sec, providing a balance between rapid docking and undocking cycle times and smooth motion without excessive mechanical shock, vibration, or audible noise that could be disruptive in the surgical environment.

[0098] The actuation mechanism 402 incorporates integrated dual Halleffect feedback sensors (not explicitly depicted in the figures) that are configured to detect and provide continuous positional feedback signals indicating the realtime extension position, velocity, and direction of movement of the docking assembly 408.

[0099] In a specific implementation embodiment, each robotic surgical cart 200 may be integrated with four independent actuation mechanisms 402, with one dedicated actuation mechanism assigned to and controlling each corresponding docking assembly 304a, 304b, 304c, 304d. This four-actuator configuration provides redundancy, independent height adjustment at each comer, and the ability to compensate for significant surface irregularities through differential extension.

[0100] When the docking sequence is initiated through operator input to the control system 602 of the robotic surgical cart 200, all four actuation mechanisms 402 are simultaneously commanded to begin extending their respective docking assemblies 304a-304d downward toward the floor surface at a controlled rate. All four actuation mechanisms 402 initially move at substantially the same speed in a synchronized manner until their respective surface contact elements 412 progressively reach and establish contact with the surface beneath the robotic surgical cart 200 in the operation theater. Due to surface irregularities, floor slope, or elevation variations, the four surface contact elements 412 will typically not reach the ground surface simultaneously, but rather in a sequential manner with time intervals potentially ranging from milliseconds to several seconds depending on the magnitude of surface irregularities.

[0101] The control system 602, which is communicatively coupled through wired or wireless connections with the force sensing elements 418 in all four docking assemblies, continuously monitors the force signals from each force sensing element 418 and employs signal processing algorithms to detect which of the surface contact elements 412 first establishes contact with the ground surface. This detection is accomplished by identifying when the force signal from a particular force sensing element 418 exceeds a predetermined contact detection threshold, indicating that the corresponding surface contact element 412 has transitioned from a non-contact state to a contact state with the ground surface.Upon detecting first ground contact for a particular docking assembly, the control system 602 immediately halts further extension movement of that corresponding docking assembly by stopping or holding the position of its associated actuation mechanism 402, while allowing the remaining docking assemblies 304a-304d to continue their downward extension movement.

[0102] Once a specific actuation mechanism 402 establishes ground contact via its surface contact element 412, the corresponding docking assembly 408 transmits continuous feedback signals to the control system 602 based on the time-varying force signal generated by the force sensing element 418 as ground contact force increases. The control system 602 employs real-time signal analysis algorithms to analyze the force variations, force rates of change, and force distribution patterns to determine what adjustments are required for each actuation mechanism 402 to achieve a level platform orientation. These adjustments may be calculated using various algorithms including geometric calculations based on known docking assembly positions and measured force distributions, iterative adjustment algorithms that incrementally modify positions until level is achieved, or model-based control algorithms that predict required adjustments based on system models and measured states.

[0103] The remaining docking assemblies 304a-304d, those that have not yet established ground contact, continue to move downward toward the ground surface at the controlled extension rate until their subsequent surface contact elements 412 progressively contact the ground surface in sequential order. As each subsequent surface contact element 412 establishes ground contact, the control system 602 detects this contact event through force signal threshold detection and halts further extension movement of that corresponding docking assembly, thereby ensuring that all docking assemblies 304a-304d ultimately establish contact with the ground surface in a controlled sequential manner without applying excessive initial contact forces.

[0104] Once all four actuation mechanisms 402 have established ground contact and are under active control with force feedback from their respective force sensing elements 418 after the initial contact detection and positionadjustment phase, the control system 602 transitions to a coordinated lifting phase. In this phase, all four actuation mechanisms 402 are commanded to extend further in a synchronized and coordinated manner, operating with controlled force or position targets determined by the control algorithm to progressively lift the entire robotic surgical cart 200, including the plurality of wheels 302a-302d, vertically upward to a predefined height above the floor surface. This coordinated lifting motion is controlled to achieve uniform force distribution or uniform height across all four docking assemblies, thereby ensuring that the robotic surgical cart 200 is uniformly leveled on the uneven ground surface with a horizontal platform orientation typically within angular tolerances of less than 0.5 degrees from true horizontal.

[0105] The predefined lifting height is selected to ensure that the wheels 302a-302d of the robotic surgical cart 200 are completely disengaged from and not in contact with the floor surface, typically with a clearance gap ranging from 2 mm to 20 mm, thereby eliminating any possibility of force transmission through the wheels and ensuring that all support forces are transmitted exclusively through the four docking assemblies 304a-304d for maximum stability and rigidity. This configuration eliminates the compliance and potential rolling motion associated with wheel contact, providing a rigid four-point support base that dramatically enhances stability during surgical procedures.

[0106] In another embodiment, when the robotic surgical cart 200 is initially placed or positioned on an uneven, irregular, or sloped surface, the autoleveling mechanism automatically initiates a detection and adjustment sequence to maintain the cart position in a level orientation without requiring manual intervention. The force sensing element 418 integrated within each docking assembly 408 is configured to detect whether the ground surface exhibits evenness or unevenness characteristics through analysis of the force signal patterns, force distributions, and force variations across the multiple docking assemblies during the initial contact and loading phases.

[0107] When the robotic surgical cart 200 is commanded to transition to the docked or locked operational state through user interface input, the pluralityof wheels 302a-302d is progressively lifted above the floor surface by controlled extension of the docking assemblies such that the surface contact element 412 of each docking assembly establishes and maintains contact with the ground surface. When the force sensing element 418 detects indications of surface unevenness through analysis of force signal variations, differential forces between docking assemblies, or deviations from expected force patterns, it transmits electrical signals to the control system 602 to automatically adjust the extension position of one or more docking assemblies 408 in a corrective manner to compensate for the detected unevenness and thereby maintain the overall evenness and level orientation of the robotic surgical cart 200 on the uneven surface.

[0108] This adjustment process may be implemented as a continuous closed-loop control process that operates throughout the duration of the surgical procedure, continuously monitoring force signals and making micro-adjustments to docking assembly positions as needed to compensate for any changes in loading conditions, floor settling, thermal expansion effects, or vibrations. The continuous monitoring and adjustment capability ensures that the level orientation is maintained within specified tolerances even during extended surgical procedures lasting multiple hours and even as the robotic arms move and create time-varying dynamic loads on the cart structure.

[0109] If the robotic surgical cart 200 needs to be returned to a mobile undocked operational state for repositioning or transportation after completion of surgical procedures, then an operator activates a cart unlock button or unlock control input (as illustrated in FIG. 6) provided on the user interface of the robotic surgical cart 200. Upon receiving this unlock command, the control system 602 commands all four actuation mechanisms 402 to retract in a coordinated manner, which results in lowering the entire cart structure and pushing the wheels 302a- 302d downward until the wheels 302a-302d establish contact with and rest on the ground surface, progressively transferring the cart weight from the docking assemblies to the wheels. Once the wheels are in full contact with the floor and supporting the cart weight, the actuation mechanisms 402 continue retracting the docking assemblies 304a-304d to their fully retracted positions, lifting the surfacecontact elements 412 clear of the floor surface. At this point, the robotic surgical cart 200 is fully transitioned to the mobile undocked state and can be freely moved from one position to another position by applying manual force to the handle 208 or through powered propulsion mechanisms if incorporated.

[0110] In one embodiment, the actuation mechanism 402 is configured to include mechanical safety lock mechanisms and overload protection features as described in detail above. These safety features provide multiple layers of protection against mechanical failures, excessive forces, or unsafe operating conditions that could compromise equipment integrity or patient safety.

[0111] Furthermore, the force sensing element 418 is configured to generate electrical output signals that are proportional to applied force magnitude and to transmit these signals in real-time to the control system 602 through wired connections, wireless communication links, or bus-based communication protocols such as CAN bus, Ethernet, or RS-485. The signal transmission may include analog voltage or current signals, digital signals, or packetized data communications depending on system architecture.

[0112] Additionally, the surface contact element 412 includes guide pins 412a, 412b that are configured and positioned to engage with and slide within the guideways 426a, 426b of the docking assembly 408, providing precise linear guidance and preventing lateral displacement, rotation, or binding during vertical translation motion.

[0113] Moreover, the actuation mechanisms 402 may include integrated dual Hall effect feedback sensors, as described previously, which enable precise position monitoring with typical resolutions ranging from 0.01 mm to 0.1 mm depending on sensor configuration and signal processing implementation. These sensors provide real-time position data to the control system 602 enabling closed-loop position control algorithms.

[0114] Additionally, the force sensing element 418 provides a load capacity or measurement range from 25N to 250N as specified previously, encompassing the expected range of contact forces during leveling operations while providing adequate sensitivity and overload margin.

[0115] The control system 602 continuously monitors force sensing element 418 signals from all docking assemblies at high update rates, typically ranging from 10 Hz to 1000 Hz, and performs micro-adjustments to actuation mechanism 402 positions during ongoing surgical procedures to maintain level orientation and stability. These micro-adjustments typically involve positional corrections in the range of 0.01 mm to 1 mm and are executed automatically without operator intervention, ensuring that the cart maintains level orientation even as loading conditions change due to robotic arm movements, instrument exchanges, or other dynamic events during surgery.

[0116] Once all actuation mechanisms 402 have established ground contact and are under control after the initial contact detection and adjustment phase, they may be operated synchronously with coordinated position or force control to lift the robotic surgical cart 200 to the predefined height, ensuring that the wheels 302a-302d are completely disengaged from and not in contact with the floor surface. This configuration provides a stable four-point support base that eliminates compliance and potential motion associated with wheel contact, thereby maximizing stability and rigidity during surgical procedures where even minute vibrations or movements could adversely affect surgical outcomes.

[0117] In an embodiment, the robotic surgical cart 200 is positioned such that one of its wheels, for example wheel 302a, rests on an uneven surface within the operating theater. The uneven surface may be caused by a raised floor tile, a cable channel, or a localized depression in the flooring material. As the cart 200 transitions to the docked or locked operational state, the control system 602 initiates the auto-leveling sequence by commanding the plurality of docking assemblies 304a-304d to extend downward toward the ground.

[0118] Due to the unevenness beneath wheel 302a, the corresponding docking assembly 304a encounters the ground surface at a different elevation compared to the other docking assemblies 304b, 304c, 304d. The force sensing element 418 integrated within docking assembly 304a detects initial contact with the uneven surface and transmits a force signal to the control system 602. Upon receiving this signal, the control system 602 halts further extension of dockingassembly 304a while allowing the remaining docking assemblies 304b, 304c, and 304d to continue extending until their respective surface contact elements 412 establish contact with the ground.

[0119] Once all docking assemblies are engaged with the surface, the control system 602 synchronizes the actuation mechanisms 402 to lift the cart 200 to a predefined height (in the range of 2 mm to 20 mm above the ground surface), ensuring that all wheels, including wheel 302a, are raised above the ground and the cart is uniformly leveled. The control system 602 continuously monitors force signals from each docking assembly and makes micro-adjustments as necessary to maintain a level orientation, compensating for the initial unevenness beneath wheel 302a and providing stable support for the cart 200 throughout the surgical procedure.

[0120] In yet another aspect, a method for leveling a cart 200 on an uneven surface, wherein the cart 200 comprises a plurality of docking assemblies 304a-304d, each docking assembly including a surface contact element 412 and a force sensing element 418, the method comprising the steps of detecting, by a control system 602 operatively connected to each force sensing element 418, which surface contact element 412 of the plurality of docking assemblies 304a-304d first establishes contact with the uneven surface; halting the movement of the docking assembly 304a-304d that first contacts the uneven surface; continuing the movement of the remaining docking assemblies 304a-304d toward the uneven surface until each remaining surface contact element 412 establishes contact with the surface, and halting the movement of each corresponding docking assembly upon such contact; and thereafter, synchronously lifting the cart 200, including the plurality of wheels 302a-302d, by means of the plurality of docking assemblies 304a-304d to a predefined height so as to achieve uniform leveling of the cart 200 on the uneven surface.

[0121] In an embodiment, upon successful completion of the docking sequence and synchronous lifting of the robotic surgical cart 200 to the predefined height, the system controller transitions into an active monitoring mode. In this operational state, the controller continuously evaluates real-time feedback signalsreceived from the force sensing elements 418 integrated within each docking assembly 304a-304d. The force measurements are continuously transmitted to the control system 602 at high update rates, typically ranging from 10 Hz to 1000 Hz, enabling responsive detection of any variations in contact force status across all docking assemblies.

[0122] The force sensing elements 418 provide continuous electrical signals proportional to the contact forces at each docking assembly interface. The control system 602 processes these signals through real-time signal analysis algorithms to establish a baseline force profile indicative of secure, stable docking. The predefined nominal force range for each docking assembly 408 is established during initial docking sequence completion, taking into account the distribution of cart weight across the four docking assemblies and expected equilibrium force values for a level platform orientation.

[0123] When the feedback from any force sensing element 418 indicate an anomaly, such as a deviation from the expected force thresholds, the controller immediately identifies the nature and location of the anomaly. These anomalies may comprise contact force increases or decreases indicative of obstruction, misalignment of the docking assembly relative to the contact surface, mechanical interference caused by foreign objects or debris, shift in load distribution due to movement of robotic arms or instrument exchanges, or surface settling or thermal expansion effects during extended surgical procedures.

[0124] Upon detection of such an anomaly, the controller initiates a closed- loop corrective response mechanism. This response involves dynamically adjusting the position or orientation of the affected docking assembly 408 through finegrained command signals to its associated actuation mechanism 402. The adjustment process employs a feedback control algorithm, such as proportional- integral-derivative (PID) control or adaptive control strategies, which calculates the magnitude and direction of the required positional correction based on the measured force deviation.

[0125] The actuation mechanism 402, comprising the motor 404 and actuation shaft 406, executes these corrective commands by extending or retractingthe docking assembly 408 in precise incremental steps. These micro-adjustments typically involve positional corrections in the range of 0.01 mm to 1 mm and are executed without operator intervention. The force feedback is continuously monitored as the adjustment progresses, allowing the control system 602 to verify that the measured contact force is progressively returning toward the predefined nominal range.

[0126] This iterative adjustment process continues until the measured contact force stabilizes within the predefined nominal range, thereby restoring the docking assembly 408 to its proper operating condition. The closed-loop control mechanism ensures that the cart 200 maintains mechanical stability and secure engagement of the docking interface, thereby preserving operational integrity and preventing potential damage or misdocking scenarios. The corrective control operates continuously throughout the entire duration of the surgical procedure, making automatic micro-adjustments as needed to compensate for any changes in loading conditions, surface characteristics, thermal effects, or dynamic loading from robotic arm movements, ensuring that the level orientation and stability of the robotic surgical cart 200 are maintained within specified tolerances throughout the surgical operation.

[0127] The present disclosure is industrially applicable to robotic surgical systems and related medical equipment, particularly in providing stable, automatically leveled mobile platforms in operating theaters, surgical centers, and other medical facilities.

[0128] The foregoing descriptions of exemplary embodiments of the present disclosure have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the disclosure to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiment was chosen and described in order to best explain the principles of the disclosure and its practical application, to thereby enable others skilled in the art to best utilize the disclosure and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions, substitutions of equivalentsare contemplated as circumstance may suggest or render expedient but are intended to cover the application or implementation without departing from the spirit or scope of the claims of the present disclosure.

[0129] Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any components that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature or component of any or all the claims.

[0130] While specific language has been used to describe the disclosure, any limitations arising on account of the same are not intended. As would be apparent to a person in the art, various working modifications may be made to the apparatus in order to implement the inventive concept as taught herein.

Claims

WE CLAIM:

1. A docking assembly 408 comprising: a force sensing element 418, a biasing element 422 and a surface contact element 412 arranged on each other such that the surface contact element 412 is configured to transmit a force exerted on it to facilitate leveling of a cart 200 on an uneven surface.

2. The docking assembly 408 as claimed in claim 1, wherein the surface contact element 412 is configured to transmit the force exerted on it towards the biasing element 422 and the force sensing element 418.

3. The docking assembly 408 as claimed in claim 2, wherein the surface contact element 412 is configured to transmit the force exerted on it sequentially towards the biasing element 422 and the force sensing element 418 along a linear axis substantially perpendicular to the uneven surface.

4. The docking assembly 408 as claimed in claim 1, further comprising a biasing element cap 420 configured to encapsulate the biasing element 422, such that the biasing element 422 remains securely positioned when a force from the surface contact element 412 is exerted on the biasing element 422.

5. The docking assembly 408 as claimed in claim 1, wherein, when the surface contact element 412 touches the surface, it pushes the biasing element 422, which in turn pushes the force sensing element 418, thereby generating a force signal that is transmitted to a control system 602.

6. The docking assembly 408 as claimed in claim 1, further comprising a housing having a first hole 410a and a second hole 410b formed in opposing sidewalls thereof, wherein the first hole 410a and the second hole 410b are configured to receive a locking pin 416 for mechanical coupling with an actuation shaft 406.

7. The docking assembly 408 as claimed in claim 1, wherein the surface contact element 412 comprising: a plurality of guide pins 412a, 412b configured to rest on a circumference of a locking plate 414; a cavity 412c configured to receive the biasing element 422; and a contact element cap 412d extending from an opposite side of the cavity 412c, such that the contact element cap 412d protrudes through a locking plate hole 414a toward the surface.

8. The docking assembly 408 as claimed in claim 1, further comprising: a top side 408a, a bottom side 408b, and a locking plate 414, wherein the locking plate 414 is secured at the bottom side 408b.

9. The docking assembly 408 as claimed in claims 7 and 8, wherein the bottom side 408b of the docking assembly 408 comprising: a first cavity 424 configured to accommodate the force sensing element 418; a second cavity 426 including a plurality of guide ways 426a, 426b, wherein the plurality of guiding ways 426a, 426b is configured to accommodate the plurality of guide pins 412a, 412b of the surface contact element 412 such that the plurality of guiding ways 426a, 426b facilitate stable vertical motion of the surface contact element 412 during leveling of the cart 200 on the uneven surface.

10. The docking assembly 408 as claimed in claim 9, wherein the second cavity 426 is larger in diameter than the first cavity 424.

11. The docking assembly 408 as claimed in claim 1, further comprising an actuation mechanism 402 configured to move the docking assembly 408 in a vertical direction.

12. The docking assembly 408 as claimed in claim 11, wherein the actuation mechanism 402 comprises an integrated position feedback sensor configured to detect and provide positional feedback of the docking assembly 408.

13. The docking assembly 408 as claimed in claim 11, wherein the actuation mechanism 402 comprises a motor 404 and an actuation shaft 406.

14. The docking assembly 408 as claimed in claim 13, wherein the actuation shaft 406 includes a first end 406-1 and second end 406-2, wherein the first end 406-1 is secured to the actuation mechanism 402 and the second end 406-2 is secured to the docking assembly 408, to move the docking assembly 408 in the vertical direction.

15. The docking assembly 408 as claimed in claim 14, wherein the second end 406-2 of the actuation shaft 406 includes a hole 406a at which a locking pin 416 is positioned, the locking pin 416 having a first end 416a and a second end 416b.

16. The docking assembly 408 as claimed in claims 6 and 15, wherein the first end 416a of the locking pin 416 is positioned in the first hole 410a of the docking assembly 408 and the second end 416b of the locking pin 416 is positioned in the second hole 410b of the docking assembly 408, the locking pin 416 being configured to move the docking assembly 408 in the vertical direction.

17. A cart 200, comprising: a base portion 202; a plurality of wheels 302a-302d mounted to the base portion 202 for mobility of the cart 200; a plurality of docking assemblies 304a-304d mounted to the base portion 202, each docking assembly 408 comprising: a force sensing element 418, a biasing element 422 and a surface contact element 412 arranged on each other such that the surface contactelement 412 is configured to transmit a force exerted on it to facilitate leveling of the cart 200 on an uneven surface.

18. The robotic surgical cart 200 as claimed in claim 17, wherein the leveling of the cart 200 on the uneven surface comprises the steps of configuring the plurality of docking assemblies 304a-304d to move toward the uneven surface such that the surface contact element 412, coupled to each docking assembly 408, approaches the uneven surface; detecting, by a control system 602 communicatively coupled to each force sensing element 418, which surface contact element 412 first contacts the uneven surface, and halting movement of the corresponding docking assembly 408; continuing to move the remaining docking assemblies 304a-304d toward the surface until each remaining surface contact element 412 contacts the uneven surface, and halting movement of each corresponding docking assembly 408 upon surface contact to ensure that all docking assemblies 304a-304d are engaged with the surface; and synchronously lifting the cart 200, including the plurality of wheels 302a- 302d, using the docking assemblies 304a-304d to a predefined height so as to uniformly level the cart 200 on the uneven surface.

19. The robotic surgical cart 200 as claimed in claim 18, further comprising a controller configured to, upon successful completion of the docking sequence and synchronous lifting to the predefined height, the controller transitions into an active monitoring mode in which the controller continuously evaluates, in real time, feedback from the force sensing elements 418 to detect whether contact forces remain within predefined nominal ranges indicative of secure docking, and, in response to feedback from any force sensing element 418 indicating an anomaly comprising a deviation from expected force thresholds due to an obstruction, misalignment, or mechanical interference, the controller initiates a closed-loop corrective response that dynamically adjusts the positionor orientation of the affected docking assembly 408 using an actuator mechanism 402 until the measured contact force returns to the predefined nominal range so as to ensure mechanical stability, secure engagement of the docking interface, and maintenance of operational integrity.

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