EP-4735834-A1 - SYSTEMS AND METHODS FOR INDUCTIVE PULSE FREQUENCY MODULATED POSITION SENSING

Abstract

Systems and methods are disclosed for determining an angular position of a rotary joint using a filter circuit comprising a capacitor, a variable inductor comprising a moveable target, and at least one sensing coil affixed to the rotary joint. A controller coupled to the filter circuit is disclosed. The controller transmits an input signal of varying frequency to the filter circuit, detects a signal corresponding to a response of the filter circuit to the input signal, and characterizes a frequency response of the filter circuit based on a determination that the signal corresponding to the response is corrupted. The controller determines an inductance value of the variable inductor based on the frequency response of the filter circuit, and the angular position of the rotary joint based on the inductance value which is indicative of a positional relationship between the moveable target and the at least one sensing coil.

Inventors

• FAY, DANIEL
• MCCOLLUM, Tyler

Assignees

• Vicarious Surgical Inc.

Dates

Publication Date

20260506

Application Date

20240701

Claims (20)

1. 1. A system for determining an angular position of a rotary joint, the system comprising: a filter circuit comprising: a capacitor; a variable inductor comprising a moveable target, and at least one sensing coil affixed to the rotary joint; and a controller coupled to the filter circuit, the controller programed or configured to: transmit an input signal of varying frequency to the filter circuit; detect a signal corresponding to a response of the filter circuit to the input signal; characterize a frequency response of the filter circuit based at least in part on a determination that the signal corresponding to the response of the filter circuit is corrupted; determine: an inductance value of the variable inductor based at least in part on the frequency response of the filter circuit, and the angular position of the rotary joint based at least in part on the inductance value which is indicative of a positional relationship between the moveable target and the at least one sensing coil.
2. 2. The system of claim 1, wherein the input signal is frequency modulated using the varying frequency.
3. 3. The system of claim 1, wherein the determination that the signal corresponding to the response of the filter circuit is corrupted is based at least in part on the input signal being modulated by a frequency above a certain threshold.
4. 4. The system of claim 3, wherein the controller comprises a Universal Asynchronous Receiver Transmitter (UART) receiver and a Universal Asynchronous Receiver Transmitter (UART) transmitter.
5. 5. The system of claim 1, wherein the filter circuit further comprises a fixed value capacitor.
6. 6. The system of claim 1, wherein the rotary joint is within a robotic arm.
7. 7. A non-transitory computer-readable medium storing computer-executable instructions therein, which when executed by at least one processor in a controller, cause the at least one processor to perform the operations of: transmitting an input signal of varying frequency to a filter circuit; detecting a signal corresponding to a response of the filter circuit to the input signal; characterizing a frequency response of the filter circuit based at least in part on a determination that the signal corresponding to the response of the filter circuit is corrupted; determining: an inductance value of a variable inductor based at least in part on the frequency response of the filter circuit, wherein the variable inductor comprises a moveable target, and at least one sensing coil affixed to a rotary joint, and an angular position of the rotary joint based at least in part on the inductance value which is indicative of a positional relationship between the moveable target and the at least one sensing coil.
8. 8. The non-transitory computer-readable medium of claim 7, wherein the input signal is frequency modulated using the varying frequency.
9. 9. The non-transitory computer-readable medium of claim 7, wherein the determination that the signal corresponding to the response of the filter circuit is corrupted is based at least in part on the input signal being modulated by a frequency above a certain threshold.
10. 10. The non-transitory computer-readable medium of claim 7, wherein the controller comprises a Universal Asynchronous Receiver Transmitter (UART) receiver and a Universal Asynchronous Receiver Transmitter (UART) transmitter.
11. 11. The non-transitory computer-readable medium of claim 8, wherein the filter circuit further comprises a fixed value capacitor.
12. 12. The non-transitory computer-readable medium of claim 7, wherein the rotary joint is within a robotic arm.
13. 13. The non-transitory computer-readable medium of claim 7, wherein the angular position of the rotary joint changes based at least in part on a thickness or the width the moveable target.
14. 14. A method of determining an angular position of a rotary joint, the method comprising: transmitting an input signal of varying frequency to a filter circuit; detecting a signal corresponding to a response of the filter circuit to the input signal; characterizing a frequency response of the filter circuit based at least in part on a determination that the signal corresponding to the response of the filter circuit is corrupted; determining: an inductance value of a variable inductor based at least in part on the frequency response of the filter circuit, wherein the variable inductor comprises a moveable target, and at least one sensing coil affixed to a rotary joint, and an angular position of the rotary joint based at least in part on the inductance value which is indicative of a positional relationship between the moveable target and the at least one sensing coil.
15. 15. The method of claim 14, wherein the input signal is frequency modulated using the varying frequency.
16. 16. The method of claim 14, wherein the determination that the signal corresponding to the response of the filter circuit is corrupted is based at least in part on the input signal being modulated by a frequency above a certain threshold.
17. 17. The method of claim 14, wherein the controller comprises a Universal Asynchronous Receiver Transmitter (UART) receiver and a Universal Asynchronous Receiver Transmitter (UART) transmitter.
18. 18. The method of claim 14, wherein the filter circuit further comprises a fixed value capacitor.
19. 19. The method of claim 14, wherein the rotary joint is within a robotic arm.
20. 20. The method of claim 14, wherein the angular position of the rotary joint changes based at least in part on a thickness or the width the moveable target.

Description

SYSTEMS AND METHODS FOR INDUCTIVE PULSE FREQUENCY MODULATED POSITION SENSING Cross-Reference to Related Applications [0001] This application claims the benefit of U.S. Provisional Patent Application No. 63/524,220, filed June 30, 2023, the entire contents of which are incorporated herein by reference in their entirety. Background of the Disclosure [0002] Surgical robotic systems permit a user (also described herein as an “operator” or a “user”) to perform an operation using robotically-controlled instruments to perform tasks and functions during a procedure. Position sensors are used within one or more robotic arms of the surgical robotic system to output signals to a processor that can be used to resolve the position of the one or more arms within a cavity of a patient during a surgical procedure. [0003] Position sensors allow a user to determine the position of the robotic arm joints. One type of position sensor is known as a Hall effect sensor. [0004] Conventional hardware that is used to determine the positon or angles of rotary joints includes flexible printed circuit boards (PCBs) that bend within the confines of robotic arms, and include a set of four very small hall-effect sensors per joint to determine the joint angles. Summary [0005] A system for determining an angular position of a rotary joint, the system is presented. The system comprises a filter circuit comprising a capacitor, a variable inductor and controller coupled the filter circuit. The variable inductor can comprise a moveable target, and at least one sensing coil affixed to the rotary joint. The controller can be programed or configured to transmit an input signal of varying frequency to the filter circuit. The controller can be further programmed or configured to transmit an input signal of varying frequency to the filter circuit. The controller can be further programmed or configured to detect a signal corresponding to a response of the filter circuit to the input signal. The controller can be further programmed or configured to characterize a frequency response of the filter circuit based at least in part on a determination that the signal corresponding to the response of the filter circuit is corrupted. The controller can be further programmed or configured to determine an inductance value of the variable inductor based at least in part on the frequency response of the filter circuit. The controller can be further programmed or configured to determine the angular position of the rotary joint based at least in part on the inductance value which is indicative of a positional relationship between the moveable target and the at least one sensing coil. Brief Description of the Drawings [0006] These and other features and advantages of the present invention will be more fully understood by reference to the following detailed description in conjunction with the attached drawings in which like reference numerals refer to like elements throughout the different views. The drawings illustrate principals of the invention and, although not to scale, show relative dimensions. [0007] FIG. 1 schematically depicts an example surgical robotic system in accordance with some embodiments. [0008] FIG. 2A is an example perspective view of a patient cart including a robotic support system coupled to a robotic subsystem of the surgical robotic system in accordance with some embodiments. [0009] FIG. 2B is an example perspective view of an example operator console of a surgical robotic system of the present disclosure in accordance with some embodiments. [0010] FIG. 3 A schematically depicts an example side view of a surgical robotic system performing a surgery within an internal cavity of a subject in accordance with some embodiments. [0011] FIG. 3B schematically depicts an example top view of the surgical robotic system performing the surgery within the internal cavity of the subject of FIG. 3 A in accordance with some embodiments. [0012] FIG. 4A is an example perspective view of a single robotic arm subsystem in accordance with some embodiments. [0013] FIG. 4B is an example perspective side view of a single robotic arm of the single robotic arm subsystem of FIG. 4A in accordance with some embodiments. [0014] FIG. 5 is an example perspective front view of a camera assembly and a robotic arm assembly in accordance with some embodiments. [0015] FIG. 6A is an example perspective view of a left hand controller for use in an operator console of a surgical robotic system in accordance with some embodiments. [0016] FIG. 6B is an example perspective view of a right hand controller for use in an operator console of a surgical robotic system in accordance with some embodiments. [0017] FIG. 7A is an example perspective view of a left hand controller for use in an operator console of a surgical robotic system in accordance with some embodiments. [0018] FIG. 7B is an example perspective view of a right hand controller for use in an operator console of a surgical r