Systems and methods for evaluating an oscillatory motion regulatory device

Abstract

A system and method for evaluating an oscillatory motion regulating device include a base, an oscillation mechanism, a motion sensor, and one or more processors. The base includes a plate body and an edge beam. The plate body has an upper surface, a lower surface opposite to the upper surface, and three or more edges. The edge beam is extended from one of the edges, the edge beam is configured to be mechanically attached to an oscillatory motion regulating device. The oscillation mechanism is mechanically coupled to the upper surface of the plate body. The motion sensor is operable to monitor an oscillatory motion of the base. The one or more processors are configured to cause the motion sensor to generate an oscillatory motion data of the base.

Description

SYSTEMS AND METHODS FOR EVALUATING AN OSCILLATORY MOTION REGULATORY DEVICECROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to U.S. Provisional Application Serial No. 63 / 549,287, filed February 2, 2024, the entire contents of which are incorporated herein by reference.TECHNICAL FIELD

[0002] The present disclosure relates to evaluating systems, and more particularly, to evaluating systems for devices that regulate oscillatory motion.BACKGROUND

[0003] Several types of vehicles experience oscillatory motions, such as rolling and pitching, including automobiles on rugged roads, ships experiencing heavy waves and winds, and aircraft shaken by turbulence. Such oscillatory motions can make vehicles unstable and dangerous. Efforts to develop a stabilizer that regulates rolling and pitching oscillation have been challenging for a variety of reasons. Sub- or full-scale prototypes for testing stabilizing systems often fail to recapitulate real-world conditions, while evaluating stabilizing systems on real- world vehicles is impractical and expensive. Consequently, there is a demand for a system and method that can effectively test an oscillatory motion regulating device.SUMMARY

[0004] In one embodiment, a system and method for evaluating an oscillatory motion regulating device include a base, an oscillation mechanism, a motion sensor, and one or more processors. The base includes a plate body and an edge beam. The plate body has an upper surface, a lower surface opposite to the upper surface, and three or more edges. The edge beam is extended from one of the edges, the edge beam is configured to be mechanically attached to an oscillatory motion regulating device. The oscillation mechanism is mechanically coupled tothe upper surface of the plate body. The motion sensor is operable to monitor an oscillatory motion of the base. The one or more processors are configured to cause the motion sensor to generate an oscillatory motion data of the base.

[0005] In a second embodiment, a method for evaluating an oscillatory motion regulating device includes causing, using one or more processors, an oscillatory motion regulating device to regulate an oscillatory motion of a base, the base comprising a plate body and an edge beam, wherein the plate body comprises an upper surface, a lower surface opposite to the upper surface, and three or more edges, an oscillation mechanism mechanically coupled to the upper surface of the plate body of the base, a wire mechanically coupled to the lower surface of the plate body of the base, and the edge beam is extended from one of the edges, the oscillatory motion regulating device configured to be mechanically attached to the edge beam, generating, using a motion sensor, an oscillatory motion data of the base, and evaluating a performance of the oscillatory motion regulating device based on the oscillatory motion data of the base.

[0006] These and additional features provided by the embodiments described herein will be more fully understood in view of the following detailed description, in conjunction with the drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The embodiments set forth in the drawings are illustrative and exemplary in nature and not intended to limit the subject matter defined by the claims. The following detailed description of the illustrative embodiments can be understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals and in which:

[0008] FIG. 1 schematically depicts an example system for evaluating oscillatory motion regulation of the present disclosure, according to one or more embodiments shown and described herein;

[0009] FIG. 2 schematically depicts an exploded-view of the example system for evaluating oscillatory motion regulation as in FIG. 1 of the present disclosure, according to one or more embodiments shown and described herein;

[0010] FIG. 3A schematically depicts an example oscillatory motion regulating device of system for evaluating oscillatory motion regulation of the present disclosure, according to one or more embodiments shown and described herein;

[0011] FIG. 3B schematically depicts an example flywheel actuator in the oscillatory motion regulating device of FIG. 3A of the present disclosure, according to one or more embodiments shown and described herein;

[0012] FIG. 4 schematically depicts an example system for evaluating oscillatory motion regulation having an outer frame of the present disclosure, according to one or more embodiments shown and described herein;

[0013] FIG. 5 illustrates a flow diagram of an evaluation process of oscillatory motion regulation devices using the system of the present disclosure, according to one or more embodiments shown and described herein;

[0014] FIG. 6 schematically depicts exemplary non-limiting components of a controller of the present disclosure, according to one or more embodiments shown and described herein;

[0015] FIG. 7 illustrates a flow diagram of the method for evaluating oscillatory motion regulating devices of the present disclosure, according to one or more embodiments shown and described herein;

[0016] FIG. 8 illustrates graphs showing example results of roll angle, velocity, and acceleration comparisons of the present disclosure, according to one or more embodiments shown and described herein; and

[0017] FIG. 9 illustrates graphs showing example results of roll accelerations in the frequency domain of the present disclosure, according to one or more embodiments shown and described herein.DETAILED DESCRIPTION

[0018] Many types of vehicles, including automobiles, ships, and aircraft, experience oscillatory motions such as rolling and pitching due to external forces like road irregularities, ocean waves, and air turbulence. These oscillations can compromise stability, cause undesired performance, and cause discomfort for passengers, ultimately affecting customer satisfaction and operational efficiency. Various stabilization mechanisms have been developed to counteract these oscillations, including active suspension systems for automobiles, fin and gyro stabilizers for ships, and autopilot-controlled adjustments for aircraft. However, these solutions often address only specific aspects of oscillatory motion and may have inherent response time limitations.

[0019] The development and validation of stabilizers designed to regulate oscillatory motion typically require testing on actual vehicles or large-scale prototypes. This approach is often impractical due to high costs, logistical challenges, and the need for repeated modifications. Installing a stabilizer system on a vehicle under real-world conditions is not only expensive, but also time-consuming, making it difficult for manufacturers to efficiently refine their designs and control algorithms.

[0020] To address these challenges, the disclosed system and method provide a platform for evaluating oscillatory motion regulation of a wide range of oscillatory motion regulating devices in a controlled and cost-effective manner. Unlike existing testing methods that require integration with a full vehicle, this system allows developers to test and refine stabilizer performance without the need for full-scale implementation. By simulating various oscillatory conditions, the system and method disclosed herein enable a more efficient evaluation of stabilization mechanisms, improving the development process while reducing costs and time constraints.

[0021] One or more specific embodiments of the present disclosure will be described below. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project,numerous implementation-specific decisions must be made to achieve the developers’ specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

[0022] The present disclosed systems and methods can evaluate and / or test vast types of oscillatory motion regulation devices, such as actuators, for an object, such as a vehicle. The disclosed systems and method may further test any actuators and algorithms and validate their performance, which counteracts the oscillation of a targeted system. The present disclosed systems can also function as an oscillation-generating device. The disclosed systems and methods can test not only any configurations of actuators, but also their algorithms installed on a system that has oscillating behavior. Such actuators adjust the system’s oscillation frequency and magnitude (to be a certain target frequency and magnitude or zero). The disclosed systems and methods may include one or more example systems that include one or more actuators and / or control moment gyroscopes (CMGs) to stabilize the system or a target object like a vehicle against undesired oscillation. The present disclosed systems may possess three rotational and / or translational Degrees of Freedom (DOF), such as one DOF, two DOF, or three DOF.

[0023] Throughout the disclosure, the center of gravity refers to a point of an object where the weighted relative position of the distributed mass of the object sums to zero.

[0024] Various embodiments of the methods and systems for evaluating oscillatory motion regulating devices are described in more detail herein. Whenever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts.

[0025] As used herein, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a” component includes aspects having two or more such components unless the context clearly indicates otherwise.

[0026] As used herein, the term “about,” when referring to a value or to an amount of mass, weight, time, volume, size, concentration or percentage is meant to encompass variations of ±20% in some embodiments, ±10% in some embodiments, ±5% in some embodiments, ±1% in some embodiments, ±0.5% in some embodiments, and ±0.1% in some embodiments from the specified amount, as such variations are appropriate to perform the disclosed method.

[0027] As used herein, the term “mechanically coupled to” may refer to various mechanical coupling means used to connect two mechanical components, for example, to transfer motion, power, or both. The mechanical coupling means may include, without limitation, rigid couplings (e.g., sleeve / clamp coupling), flange coupling (e.g., bolted flanged ends), flexible couplings (e.g., jaw coupling, gear couplings, Oldham couplings), magnetic couplings, universal joints (e.g., hooke joint), resilient couplings, bellows couplings, chain and belt couplings, or spline and keyed couplings.

[0028] Turning to the figures, FIGS. 1 and 2 schematically depict a stabilizer evaluating system 100 for one or more oscillatory motion regulating devices 103 for a vehicle or an object of the present disclosure. The stabilizer evaluating system 100 may include a base 101, one or more oscillation mechanisms 105, and a controller 601. Throughout this disclosure, the oscillatory motion regulating device 103 may be referred to as a Control Moment Gyroscope (CMG). The one or more oscillatory motion regulating devices 103 may be mechanically attached to the base 101. In some embodiments, one of the oscillatory motion regulating devices 103 may include a flywheel actuator 301 and a gimbal servo actuator 303. The stabilizer evaluating system 100 may further include one or more oscillation mechanisms 105 mechanically coupled to the base 101. The stabilizer evaluating system 100 may further include a controller 601 (as in FIG. 6), which may include one or more processors 604 (as in FIG. 6).

[0029] In some embodiments, the stabilizer evaluating system 100 may evaluate the stabilization and / or regulation of an oscillatory motion of a vehicle. The vehicle may be an automobile or any other passenger or non-passenger vehicle such as, for example, a terrestrial, aquatic, and / or airborne vehicle. The vehicle may be an autonomous vehicle that navigates its environment with limited human input or without human input. The vehicle may include actuators for driving the vehicle, such as a motor, an engine, or any other powertrain. The vehiclemay move or appear on various surfaces, such as, without limitation, roads, highways, streets, expressway, bridges, tunnels, parking lots, garages, off-road trails, railroads, or any surfaces where the vehicles may operate.

[0030] In some embodiments, the base 101 may include a plate body 201 and one or more edge beams 211. The plate body 201 may have three or more edges 205, an upper surface 203, and a lower surface 204 opposite to the upper surface 203. The edge beam 211 may be extended from one of the edges 205. For example, as illustrated in FIGS. 1 and 2, two edge beams 211 can be extended from a left edge 205a and a right edge 205b of the plate body 201. The one or more oscillatory motion regulating devices 103 may be mechanically attached to one or more edge beams 211. For example, as illustrated in FIGS. 1 and 2, two oscillatory motion regulating devices 103 can be mechanically coupled to the two edge beams 211, for example, through flange coupling with one or more bolts. The oscillation mechanism 105 may be mechanically coupled to the upper surface 203 of the plate body 201 of the base 101, for example, using one or more screw extensions 115. The base 101 may be made of, without limitation, metal (e.g., aluminum, steel, titanium, magnesium alloys), polymer (e.g., polycarbonate, nylon, polylactic acid, rubber), composite, or ceramics. The base 101 may be three-dimensional (3-D) printed. In some embodiments, the base 101 may host various electronics. For example, on the upper surface 203 of the base 101, one or more motion sensors 608 (e.g., an inertial measurement unit sensor (IMU) 628, an angular sensor 638), the controller 601 (e.g., a Micro Controller Unit), and / or a power distribution board 510 (e.g., as in FIG. 4) may be integrated with routed wiring.

[0031] In some embodiments, the stabilizer evaluating system 100 may further include one or more power sources 109. The power sources 109 may further include the power distribution board 510 (as in FIG. 5). The power sources 109 may be operable to provide electric power to various components of the stabilizer evaluating system 100, e.g., oscillatory motion regulating devices 103, such as the flywheel actuator 301 and the gimbal servo actuator 303. The power source may include any wireless (e.g., batteries) and wired source (e.g., power outlet). For example, as illustrated in FIGS. 1 and 2, the power sources 109 may include two lithium-polymer batteries. The power sources 109 may be positioned at opposite ends of the upper surface 203 of the base 101. The power sources 109 may be securely attached to the base101, for example, using robust Velcro straps. The power sources 109 may be arranged according to the center of gravity 113 to maintain a balance of the moment of inertia of the stabilizer evaluating system 100. For example, the two power sources 109 in FIGS. 1 and 2 can be symmetrically arranged about the center of gravity 113.

[0032] In some embodiments, the stabilizer evaluating system 100 may include one or more oscillatory motion regulating devices 103. The stabilizer evaluating system 100 may include one or more actuators and oscillatory motion regulating algorithms that can be tested to regulate the oscillatory motion. The oscillatory motion regulating device 103 may include any torque and / or force-generating devices, such as, without limitation, the flywheel actuator 301, the gimbal servo actuator 303, electric motors, hydraulic cylinders, pneumatic actuators, piezoelectric actuators, linear actuators, stepper motors, solenoids, or any actuators that can be used to control movement, apply force, or generate torque in the stabilizer evaluating system 100. The oscillatory motion regulating algorithms that can be programmed in the controller 601 (as in FIG. 6) to control the actuators can be used. The oscillatory motion regulating devices 103 and the oscillatory motion regulating algorithms may regulate the oscillatory motion of an object, without limitation, a vehicle, to stabilize or adjust the frequency and magnitude with the desired ones. At least one oscillatory motion regulating device 103 may include one or more motors, such as, without limitation, a brushless direct current (BFDC) motor (e.g., for flywheel rotation), a servo motor (e.g., for controlling gimbal movement), or a combination thereof.

[0033] In some embodiments, the stabilizer evaluating system 100 may include one or more motion sensors 608. The motion sensors 608 may include, without limitation, an IMU sensor, an angular sensor, a vision sensor, a light detection and ranging sensor, a thermal image sensor, an infrared sensor, an ultrasonic sensor, or a combination thereof. For example, the stabilizer evaluating system 100 may include the IMU sensor 628 (e.g., as in FIG. 6) configured to monitor the oscillatory motion of the base 101. In some embodiments, the stabilizer evaluating system 100 may include one or more IMU sensors 628 to monitor the oscillatory motion data of the base 101. The stabilizer evaluating system 100 may include the angular sensor 638 (e.g., as in FIG. 6) configured to monitor a rotation speed of the flywheel actuator 301 and an angular velocity of the gimbal servo actuator 303. In some embodiments, the stabilizer evaluating system 100 may monitor oscillatory motion data of the base 101, such as oscillatory motion data. Theoscillatory motion data may include, without limitation, translational position, velocity, acceleration, orientation, angular velocity, angular acceleration of the vehicle, or a combination thereof.

[0034] In some embodiments, the stabilizer evaluating system 100 may include one or more oscillation mechanisms 105, such as, without limitation, springs, pendulums, vibrating masses, torsional elements, elastic membranes, coupling devices, linkages, gears, belts, levers, or magnetic couplings, an oscillation-generating system or mechanism, or compliant structures designed to store and release energy cyclically. These components can facilitate the efficient transmission of oscillatory energy between the oscillatory motion regulating devices 103 and the stabilizer evaluating system 100, enabling highly accurate oscillation motion control, damping, amplification, or synchronization of oscillations. For example, the stabilizer evaluating system 100 may maintain and / or regulate oscillatory motions of the base via the one or more oscillation mechanisms 105 when the external force or torque is excited on the base. The external force or torque to the vehicle may be applied by a human or any oscillationgenerating system or mechanism. The oscillatory motions of the base 101 of the stabilizer evaluating system 100 may be measured by the motion sensor 608 (e.g., as in FIG. 6) and processed via a microcontroller unit or the controller 601.

[0035] In some embodiments, the oscillation mechanisms 105 may secure the stabilizer evaluating system 100 and induce disturbances. The oscillation mechanisms 105 may be selected based on the capacity of the oscillation mechanism 105 to store energy and release it in the form of oscillations. In some embodiments, parameters of the oscillation mechanisms may be selected to achieve a target vibration frequency of the base 101 (or a projected system, such as a vehicle), such as, without limitation, from about 0.1 Hz to about 3 Hz, from about 0.2 Hz to about 2.5 Hz, from about 0.5 Hz to about 2 Hz, from 0.8 Hz to 1.8 Hz, from 1 Hz to 1.5 Hz, or any value between about 0 Hz to about 3 Hz. The parameters of the oscillation mechanism 105 may include a spring stiffness, a spring mounting point in the stabilizer evaluating system 100 (e.g., the screw extension 115 on the base 101), an inertia of the rotating point, or a combination thereof. For example, as illustrated in FIGS. 1 and 2, and the mounting point of the oscillation mechanisms 105 may be positioned close to the center of gravity 113 of the stabilizer evaluating system 100 to minimize vertical oscillations, horizontal oscillations,or both. The spring stiffness may be selected proportional to a square of a target vibration frequency of the base or a targeted system (e.g., the vehicle) to implant the oscillatory motion regulating devices 103. For example, the spring stiffness of the oscillation mechanisms may be determined using Equation 1 derived from a simple harmonic motion below:kO = ( )E£l-1where kgis the stiffness of the oscillation mechanism 105, fgis the target vibration frequency, lgis the distance between the center of gravity 113 of the stabilizer evaluating system 100 and an oscillation mechanism mounting point (e.g., at or around the screw extension 115), and Igis the inertia of the oscillating body (e.g., the base 101 and the integrated components). For example, in one embodiment, when the stabilizer evaluating system 100 is adapted for a target vibration frequency 1 Hz with an lg30 mm and an Ig0.039 kgm2, a desired kgis 431 N / m. Accordingly, the oscillation mechanism 105 can be selected based on the desired designs.

[0036] In some embodiments, the stabilizer evaluating system 100 may include a wire 107 mechanically coupled to the lower surface 204 of the plate body 201 of the base 101. The wire 107 may be configured to limit a translational movement of the base 101 so that the base 101 can be affixed to an external structure of the object or the vehicle, or an outer frame 401 (as in FIG. 4). The wire 107 may permit rotational oscillations while effectively preventing unintended vertical and horizontal motion of base 101. The wire 107 may be a metal wire, such as, without limitation, a steel wire.

[0037] In some embodiments, the stabilizer evaluating system 100 may include one or more brackets 111 mechanically coupling the one or more oscillatory motion regulating devices 103 to the one or more edge beams 211 of the base 101. For example, as illustrated in FIGS. 1 and 2, two brackets 111 each may have a C shape or a U shape to clamp the oscillatory motion regulating device 103 within and may be mechanically mounted onto the left or the right edgebeam 211 through flange coupling. The brackets 111 may be designed to facilitate adjustments to the vertical center of gravity of the stabilizer evaluating system 100. The brackets 111 may be 3-D printed using Polylactic Acid (PT A).

[0038] The stabilizer evaluating system 100 may include one or more processors 604 (as in FIG. 6). The processor may be included, without limitations, in the controller 601 (as in FIG. 6), a computer, a laptop, a tablet, a smartphone, the vehicle, a server, or a third-party electronic device.

[0039] Referring to FIGS. 3 A and 3B, an example oscillatory motion regulating device 103 to be evaluated by the stabilizer evaluating system 100 is depicted. The oscillatory motion regulating device 103 may include an external cover 207 including one or more frames to host the flywheel actuator 301 and the gimbal servo actuator 303. The flywheel actuator 301 may include a wheel 313 and one or more wheel covers 311 to define a cavity for the wheel 313 to be arranged within. For example, as illustrated in FIG. 3B, the wheel 313 may rotate around an axis in the y-axis. The wheel covers 311 may include one or more front / rear wheel covers that cover the front (positive y-axis) and the back (negative y-axis) of the wheel 313. The wheel covers 311 may include one or more side wheel covers that cover the left (negative x-axis) and right (positive x-axis) of the wheel 313. The wheel covers 311 may be in, without limitation, a ring shape (e.g., a rectangular ring shape in FIGS. 1-3B), a cylindrical shape, in a dome shape, a conical, or a combination. The gimbal servo actuator 303 may be arranged above and / or under the flywheel actuator 301.

[0040] In some embodiments, the oscillatory motion regulating device 103 may include other actuators. The actuators, including the flywheel actuator 301 and the gimbal servo actuator 303, may provide motion energy to adjust the attitude of the vehicle. In some embodiments, the oscillatory motion regulating device 103 may produce the torque and drive the vehicle to induce rotation. In some embodiments, the actuators may be reaction wheels (RWs) or control moment gyroscopes (CMGs). The oscillatory motion regulating device 103 may include one or more flywheels and gimbals such that a cluster of the CMGs may produce the control torque by controlling the rotational velocities of the flywheels and directions of their angular momentum. The oscillatory motion regulating device 103 may include one or more flywheels such that acluster of the RWs may generate the control torque by changing the magnitudes of angular momentum (e.g. proportional to the rotational speed) of the flywheels. The oscillatory motion regulating device 103 may generate control torque to change the attitude, angular velocity, and / or angular acceleration of the vehicle. The control torque can be produced by changing the angular momentum magnitude, direction, or combination thereof. The angular momentum magnitude can be changed by adjusting the rotational speed of the flywheel. The magnitude of the torque can be changed by adjusting the angular momentum magnitude. The angular momentum direction can be changed by adjusting the gimbal angle. The magnitude of the torque can be changed by adjusting the gimbal rate.

[0041] In some embodiments, the oscillatory motion regulating device 103 may encounter situations where it fails to generate the control torque due to hardware limits, such as, without limitations, the flywheel speed, gimbal angle range, or gimbal rate. Each oscillatory motion regulating device 103 may include three axes (pitch axis for tilt that permits the vehicle to tilt up or down, roll axis for roll that permits the vehicle to roll from side to side, yaw axis for pan that permits the vehicle to pan left or right), and one or more sensors, such as, without limitations, an IMU sensor, an accelerometer, a gyroscope, a gimbal encoder, and a tachometer. The IMU sensor may be configured to measure the attitude, angular velocity, and / or angular acceleration of a vehicle. The oscillatory motion regulating device 103 may further include one or more encoders and / or tachometers configured to measure the angular position and angular velocity of the gimbal of the oscillatory motion regulating device 103 and one or more tachometers configured to measure the rotation rate of the flywheel of the oscillatory motion regulating device 103. The oscillatory motion regulating device 103 may be mechanically attached to the vehicle to counteract external torque or movements, allowing the stabilized vehicle to remain level and steady.

[0042] The stabilizer evaluating system 100 may include the one or more motion sensors 608. The motion sensors 608 may include, without limitation, one or more of the IMU sensor 628, the angular sensor 638, accelerometers, gyroscopes, magnetometers, or a combination thereof. The motion sensors 608 may be mechanically coupled to the stabilizer evaluating system 100. In some embodiments, the motion sensors 608 may be mechanically coupled to the base 101 and / or the oscillatory motion regulating device 103. The motion sensors 608 maygenerate state information of the stabilizer evaluating system 100 such as, without limitations, velocity, acceleration, attitude, and rotational rate of the stabilizer evaluating system 100 or the actuators in the oscillatory motion regulating devices 103.

[0043] Referring to FIG. 4, an example stabilizer evaluating system 100 for evaluating oscillatory motion regulation having the outer frame 401 is depicted. In some embodiments, the assemblies of the base 101, the oscillatory motion regulating devices 103 may be mechanically coupled to the outer frame 401 through the oscillation mechanisms 105. The outer frame 401 may be in a form of a polyhedron structure, such as, without limitation, a cube, a tetrahedron, an octahedron, or a dodecahedron, and include a plurality of members 403. The members 403 may include several edge members 403a, each of which serves as an edge of the outer frame 401. The members 403 may further include one or more internal members 403b, which are connected to the edge members 403a at one or both ends of the internal members 403b. The internal members 403b above the base 101 may be mechanically coupled to the oscillation mechanisms 105, for example, through screw extensions 115. In some embodiments, the wire 107 may be mechanically coupled to one of the internal member 403b beneath the base 101. The members 403 may be made of, without limitation, metal (e.g., aluminum, steel, titanium, magnesium alloys), polymer (e.g., polycarbonate, nylon, polylactic acid, rubber), composite, or ceramics.

[0044] Referring to FIG. 5, a flow diagram of an evaluation process for an oscillatory motion regulating device 103 using the stabilizer evaluating system 100 is depicted. In some embodiments, the power sources 109 may include the power distribution board 510 to supply electricity to various components and devices of the stabilizer evaluating system 100, such as, the controller 601, the oscillatory motion regulating devices 103, the motor drivers 609 driving the actuators of the oscillatory motion regulating devices 103, and / or the motion sensors 608. The controller 601 may receive oscillatory motion data (e.g., speed, vibration amplitude and frequency, attitude data) of the base 101 generated by motion sensors 608 and may determine an oscillatory state of the base 101. The controller 601 may determine whether an oscillatory motion regulation is needed and generate the required adjustment if an oscillatory state deviation is beyond a deviation threshold (e.g., a vibration frequency is beyond an acceptable value, such as, 1.5 Hz, or the vibration frequency is less than a desired value, such as, 0.1 Hz). The controller601 may determine desired operation parameters for the actuators in the oscillatory motion regulating device 103, such as rotating speed for the flywheel actuator 301, and / or angular velocity for the gimbal servo actuator 303. The controller 601 may send commands to the motor drivers 609 (e.g., the BLDC motor driver to control flywheel rotation and / or a servo motor driver to control gimbal movement) to operate the actuators according to the determined parameters. The motion sensors 608 may continuously monitor the oscillatory state of the base 101 and the state of the actuators in the oscillatory motion regulating devices 103, such as, without limitation, actual rotating speed, actual angular velocity, and / or other relevant parameters. The sensor data may be sent back to the controller 601 for comparison against the desired oscillatory parameters, and evaluate a performance of the oscillatory motion regulation of the oscillatory motion regulating devices 103 and related oscillatory motion regulating algorithms in performing the oscillatory motion regulation.

[0045] In some embodiments, the oscillatory motion regulating algorithms may be included in the controller 601, such as in the actuation module 632 (as in FIG. 6). The oscillatory motion regulating algorithms may use oscillatory motion regulating device 103 to generate a control torque to compensate for undesirable torque and enhance the stability of the base 101. The oscillatory motion regulating algorithms may calculate the undesirable torque based on the sensory data generated by the motion sensors 608 (such as the IMU, accelerometers, and gyroscopes). The oscillatory motion regulating algorithms may calculate the control torque based on the undesirable state deviation and control the oscillatory motion regulating device 103 to generate the torque, which results in adjusting the motion of the base 101. To control the oscillatory motion regulating device 103, the oscillatory motion regulating algorithms may monitor the oscillatory motion regulating device 103 by using the gimbal encoders and tachometers to measure the angle and angular velocity of the flywheel actuator 301 and the gimbal servo actuator 303. In some embodiments, the oscillatory motion regulating algorithms may receive input through a user interface to manipulate the attitude of the vehicle. The stabilizer evaluating system 100 may determine a demand torque based on the user input of the motion manipulation. The oscillatory motion regulating algorithms may operate the oscillatory motion regulating device 103 to generate the control torque to regulate the oscillatory motion of the base 101 based on the demand torque.

[0046] Referring to FIG. 6, example non-limiting components of the controller 601 are depicted. The stabilizer evaluating system 100 may include a controller 601. The controller 601 may include various modules. For example, the controller 601 may include a sensing module 622, an actuation module 632, and an estimation module 642. The controller 601 may further comprise various components, such as a memory component 602, a processor 604, an input / output hardware 605, a network interface hardware 606, a data storage component 607, and a local interface 603. The controller 601 may include one or more motion sensors 608 and one or more motor drivers 609.

[0047] The controller 601 may be any device or combination of components comprising a processor 604 and a memory component 602, such as a non-transitory computer-readable memory. The processor 604 may be any device capable of executing the machine-readable instruction set stored in the non-transitory computer-readable memory. Accordingly, the processor 604 may be an electric controller, an integrated circuit, a microchip, a computer, or any other computing device. The processor 604 may include any processing component(s) configured to receive and execute programming instructions (such as from the data storage component 607 and / or the memory component 602). The instructions may be in the form of a machine-readable instruction set stored in the data storage component 607 and / or the memory component 602. The processor 604 is communicatively coupled to the other components of the controller 601 by the local interface 603. Accordingly, the local interface 603 may communicatively couple any number of processors 604 with one another, and allow the components coupled to the local interface 603 to operate in a distributed computing environment. The local interface 603 may be implemented as a bus or other interface to facilitate communication among the components of the controller 601. In some embodiments, each of the components may operate as a node that may send and / or receive data. While the embodiment depicted in FIG. 6 includes a single processor 604, other embodiments may include more than one processor 604.

[0048] The memory component 602 (e.g., a non-transitory computer-readable memory component) may comprise RAM, ROM, flash memories, hard drives, or any non-transitory memory device capable of storing machine-readable instructions such that the machine-readable instructions can be accessed and executed by the processor 604. The machine-readableinstruction set may comprise logic or algorithm(s) written in any programming language of any generation (e.g., 1GL, 2GL, 3GL, 4GL, or 5GL) such as, for example, machine language that may be directly executed by the processor 604, or assembly language, object-oriented programming (OOP), scripting languages, microcode, etc., that may be compiled or assembled into machine readable instructions and stored in the memory component 602. Alternatively, the machine-readable instruction set may be written in a hardware description language (HDL), such as logic implemented via either a field-programmable gate array (FPGA) configuration or an application-specific integrated circuit (ASIC), or their equivalents. Accordingly, the functionality described herein may be implemented in any conventional computer programming language, as pre-programmed hardware elements, or as a combination of hardware and software components. For example, the memory component 602 may be a machine-readable memory (which may also be referred to as a non-transitory processor-readable memory or medium) that stores instructions that, when executed by the processor 604, causes the processor 604 to perform a method or control scheme as described herein. While the embodiment depicted in FIG. 6 includes a single non-transitory computer-readable memory component, other embodiments may include more than one memory module. The memory may be used to store the sensing module 622, the actuation module 632, and the estimation module 642. Each of the sensing module 622, the actuation module 632, and the estimation module 642 during operating may be in the form of operating systems, application program modules, and other program modules. Such program modules may include, but are not limited to, routines, subroutines, programs, objects, components, and data structures for performing specific tasks or executing specific abstract data types according to the present disclosure as described herein.

[0049] The sensing module 622 may operably control the various sensors of the stabilizer evaluating system 100 to receive sensory data, such as the motion sensors 608 (e.g., the IMU sensor 628, the angular sensor 638). The actuation module 632 may operably control the oscillatory motion regulating device 103 to supply the control torque to the base 101. The estimation module 642 may operably estimate the performance of the oscillatory motion regulating devices 103 based on the sensory data. The actuation module 632 and the estimation module 642 may include one or more algorithms for rotation control and estimations. The one or more algorithms may be based on Artificial Intelligence (Al) techniques and are trained toallow the one or more algorithms to learn from prior control data or a range of sample sensory data regarding the torque compensation and adjustments to generate a variety of control signals. The one or more algorithms in the estimation module 642 may be trained and provided with machine-learning capabilities via a neural network as described herein. By way of example, and not as a limitation, the neural network may utilize one or more artificial neural networks (ANNs). In ANNs, connections between nodes may form a directed acyclic graph (DAG). ANNs may include node inputs, one or more hidden activation layers, and node outputs, and may be utilized with activation functions in the one or more hidden activation layers such as a linear function, a step function, logistic (sigmoid) function, a tanh function, a rectified linear unit (ReLu) function, or combinations thereof. ANNs are trained by applying such activation functions to training data sets to determine an optimized solution from adjustable weights and biases applied to nodes within the hidden activation layers to generate one or more outputs as the optimized solution with a minimized error. In machine learning applications, new inputs may be provided (such as the generated one or more outputs) to the ANN model as training data to continue to improve accuracy and minimize error of the ANN model. The one or more ANN models may utilize one to one, one to many, many to one, and / or many to many (e.g., sequence to sequence) sequence modeling. The one or more ANN models may employ a combination of artificial intelligence techniques, such as, but not limited to, Deep Learning, Random Forest Classifiers, Feature extraction from audio, images, clustering algorithms, or combinations thereof. In some embodiments, a convolutional neural network (CNN) may be utilized. For example, a convolutional neural network (CNN) may be used as an ANN that, in a field of machine learning, for example, is a class of deep, feed-forward ANNs applied for audio analysis of the recordings. CNNs may be shift or space invariant and utilize shared-weight architecture and translation.

[0050] The input / output hardware 605 may include a monitor, keyboard, mouse, printer, camera, microphone, speaker, and / or other device for receiving, sending, and / or presenting data. The input / output hardware 605 may further include one or more user interfaces. The network interface hardware 606 may include any wired or wireless networking hardware, such as a modem, LAN port, Wi-Fi card, WiMax card, mobile communications hardware, and / or other hardware for communicating with other networks and / or devices. The data storage component607 may store historical sensory data 627, historical actuator data 637, historical evaluation data 647, the sensory data received from various sensors, operation data of the various sensors and / or actuators.

[0051] The controller 601 may include one or more motion sensors 608. Each of the motion sensors 608 is coupled to the local interface 603 and communicatively coupled to the one or more processors 604. The one or more motion sensors 608 may include a selection of, without limitations, the IMU sensor 628, the angular sensor 638, a vision sensor, a light detection and ranging (EID AR) sensor, a thermal image sensor, an infrared sensor, an ultrasonic sensor, and / or a combination thereof. The controller 601 may include one or more motor drivers 609. The one or more motor drivers 609 may include, such as, without limitation, the BEDC motor driver (e.g., for controlling flywheel rotation speed), the servo motor driver (e.g., for controlling gimbal movement), or a combination thereof.

[0052] Referring to FIG. 7, a flow diagram of a method 700 using the stabilizer evaluating system 100 is illustrated. At block 701, the method 700 may include causing, using one or more processors 604 (as in FIG. 6), an oscillatory motion regulating device 103 (as in FIGS. 1 and 2) to regulate an oscillatory motion of a base 101 (as in FIGS. 1 and 2). The base 101 may include a plate body 201 (as in FIGS. 1 and 2) and an edge beam 211 (as in FIGS. 1 and 2). The plate body 201 may include an upper surface 203 (as in FIGS. 1 and 2), a lower surface 204 (as in FIGS. 1 and 2) opposite to the upper surface 203, and three or more edges 205. An oscillation mechanism 105 may be mechanically coupled to the upper surface 203 of the plate body 201 of the base 101. A wire 107 (as in FIGS. 1 and 2) may be mechanically coupled to the lower surface 204 of the plate body 201 of the base 101. The edge beam 211 may be extended from one of the edges 205 (e.g., the left edge 205a or the right edge 206b, as in FIG. 2). The oscillatory motion regulating device 103 may be configured to be mechanically attached to the edge beam 211.

[0053] At block 702, the method 700 may include generating, using a motion sensor 608 (as in FIG. 6), an oscillatory motion data of the base 101. At block 703, the method 700 may include evaluating a performance of the oscillatory motion regulating device 103 based on the oscillatory motion data of the base.

[0054] In some embodiments, the evaluating the performance of the oscillatory motion regulating device may further include monitoring, using the motion sensor 608, a reference oscillatory motion data of the base 101 in an absence of the oscillatory motion regulation from the oscillatory motion regulating device 103. The evaluating the performance of the oscillatory motion regulating device may further include evaluating the performance of the oscillatory motion regulating device 103 based on the oscillatory motion data and the reference oscillatory motion data.

[0055] In some embodiments, the oscillation mechanism 105 may be attached to the base 103 around a center of gravity of the base 101 and the oscillatory motion regulating device 103. The oscillation mechanism 105 may have a spring stiffness proportional to a square of a target vibration frequency of the base 101. The oscillatory motion data may include, without limitation, translational position, velocity, acceleration, orientation, angular velocity, angular acceleration of the base, or a combination thereof.

[0056] In some embodiments, the base 101, the oscillatory motion regulating device 103, and the oscillation mechanism 105 may be arranged in an inner space of an outer frame 401 (as in FIG. 4). The outer frame 401 may include a plurality of members 403 to define the inner space. The oscillation mechanism 105 may be mechanically coupled to one of the members 403 of the outer frame 401 above the base 101 (in the positive z-axis direction as in FIG. 4). The wire 107 may be mechanically connected to one of the members 403 of the outer frame 401 below the base 101 (in the negative z-axis direction as in FIG. 4).

[0057] Referring to FIGS. 8 and 9, graphs showing example results of roll angle, velocity, and acceleration comparisons, roll accelerations for actuator active (Case 2) and deactivated (Case 1) are illustrated. In Case 1, oscillatory motion regulating devices 103 may be deactivated. In Case 2, oscillatory motion regulating devices 103 may be operational, and their stabilizing effects on the base 101 are shown in FIGS. 8 and 9. The controller 601 may continually monitor the attitude and angular rate readings of the base 101 from the motion sensor 608. When disturbances are detected, the oscillatory motion regulating algorithms may activate the oscillatory motion regulating devices 103 to counteract these disturbances, employing desired adjustments to maintain stability of the base 101. As illustrated in FIG. 8, oscillationsdampened more rapidly in Case 2 compared to Case 1. The RMSE values for roll angle, roll velocity, and roll acceleration in Case 1 are 6.2 deg, 0.9 rad / s, and 7.4 rad / s2respectively. In contrast, these values are notably reduced to 2.7 deg, 0.4 rad / s, and 2.6 rad / s2for Case 2. As illustrated in FIG. 9, primary oscillations around the range of 1 to 1.5 Hz generated by the oscillation mechanism 105 are notably reduced.

[0058] Further aspects of the embodiments described herein are provided by the subject matter of the following numbered clauses:

[0059] Clause 1 : A system for evaluating an oscillatory motion regulating device comprising a base comprising a plate body and an edge beam, wherein the plate body has an upper surface, a lower surface opposite to the upper surface, and three or more edges, and the edge beam is extended from one of the three or more edges, the edge beam is configured to be mechanically attached to an oscillatory motion regulating device; an oscillation mechanism mechanically coupled to the upper surface of the plate body; a motion sensor operable to monitor an oscillatory motion of the base; and one or more processors configured to cause the motion sensor to generate an oscillatory motion data of the base.

[0060] Clause 2: The system according to clause 1, wherein the oscillation mechanism is attached to the base around a center of gravity of the system.

[0061] Clause 3 : The system according to any previous clause, wherein the oscillation mechanism has a spring stiffness proportional to a square of a target vibration frequency of the base.

[0062] Clause 4: The system according to any previous clause, wherein the motion sensor is an inertial measurement sensor, an angular sensor, a vision sensor, a light detection and ranging sensor, a thermal image sensor, an infrared sensor, an ultrasonic sensor, or a combination thereof.

[0063] Claus 5 : The system according to any previous clause, wherein the system furthercomprises a wire mechanically coupled to the lower surface of the plate body of the base to prevent a vertical motion, a horizontal motion, or both of the oscillatory motion regulating device.

[0064] Clause 6: The system according to any previous clause, wherein the oscillatory motion data comprises translational position, velocity, acceleration, orientation, angular velocity, angular acceleration of the base, or a combination thereof.

[0065] Clause 7: The system according to any previous clause, wherein the system further comprises a bracket mechanically coupling the oscillatory motion regulating device to the edge beam of the base.

[0066] Clause 8: The system according to any previous clause, wherein the oscillatory motion regulating device comprises a flywheel actuator, a gimbal servo actuator, or both, and the system further comprises a first angular sensor configured to monitor an angular velocity of the gimbal servo actuator; a second angular sensor configured to monitor a rotation speed of the flywheel actuator, or both.

[0067] Clause 9: The system according to any previous clause, wherein the system further comprises an outer frame, wherein the outer frame comprises a plurality of members to define an inner space, and the base, the oscillatory motion regulating device, and wherein the oscillation mechanism are arranged in the inner space.

[0068] Clause 10: The system according to clause 9, wherein the oscillation mechanism comprises a first end and a second end opposite to the first end, the first end of the oscillation mechanism mechanically attached to the base, the second end of the oscillation mechanism mechanically coupled to one of the members of the outer frame.

[0069] Clause 11 : The system according to clause 9, wherein the pluarity of members comprise a plurality of edge members and one or more internal members, and wherein the oscillation mechanism is mechanically coupled to one of the one or more internal members.

[0070] Clause 12: The system according to clause 9, wherein the system further comprises a wire mechanically coupled to the lower surface of the plate body of the base, the wire configured to be mechanically connected to one of the pluarity members.

[0071] Clause 13: A method for evaluating an oscillatory motion regulating device comprising causing, using one or more processors, an oscillatory motion regulating device to regulate an oscillatory motion of a base, the base comprising a plate body and an edge beam, wherein the plate body comprises an upper surface, a lower surface opposite to the upper surface, and three or more edges, an oscillation mechanism mechanically coupled to the upper surface of the plate body of the base, a wire mechanically coupled to the lower surface of the plate body of the base, and the edge beam is extended from one of the edges, the oscillatory motion regulating device configured to be mechanically attached to the edge beam; generating, using a motion sensor, an oscillatory motion data of the base; and evaluating a performance of the oscillatory motion regulating device based on the oscillatory motion data of the base.

[0072] Clause 14: The method according to clause 13, wherein the oscillatory motion regulating device comprises a flywheel actuator, a gimbal servo actuator, or both; and the oscillatory motion regulating device regulates the oscillatory motion of the base through adjusting a rotation speed of the flywheel actuator, an angular velocity of the gimbal servo actuator, or both to generate a torque to the base.

[0073] Clause 15: The method according to any clauses 13-14, wherein the evaluating the performance of the oscillatory motion regulating device further comprises monitoring, using the motion sensor, a reference oscillatory motion data of the base in an absence of the oscillatory motion regulation from the oscillatory motion regulating device; and evaluating the performance of the oscillatory motion regulating device based on the oscillatory motion data and the reference oscillatory motion data.

[0074] Clause 16: The method according to any clauses 13-15, wherein the oscillation mechanism is attached to the base around a center of gravity of an assembly of the base and the oscillatory motion regulating device; and the oscillation mechanism has a spring stiffness proportional to a square of a target vibration frequency of the base.

[0075] Clause 17: The method according to any clauses 13-16, wherein the oscillatory motion data comprises translational position, velocity, acceleration, orientation, angular velocity, angular acceleration of the base, or a combination thereof.

[0076] Clause 18: The method according to any clauses 13-17, wherein the base, the oscillatory motion regulating device, and the oscillation mechanism are arranged in an inner space of an outer frame; and the outer frame comprises a plurality of members to define the inner space.

[0077] Clause 19: The method according to clause 18, wherein the oscillation mechanism is mechanically coupled to one of the plurality members of the outer frame above the base.

[0078] Clause 20: The method according to clause 18, wherein the wire is mechanically connected to one of the plurality of members of the outer frame below the base.

[0079] Unless otherwise expressly stated, it is in no way intended that any method set forth herein be construed as requiring that its steps be performed in a specific order, nor that with any apparatus specific orientations be required. Accordingly, where a method claim does not actually recite an order to be followed by its steps, or any apparatus claim does not actually recite an order or orientation to individual components, or it is not otherwise specifically stated in the claims or description that the steps are to be limited to a specific order, or that a specific order or orientation to components of an apparatus is not recited, it is in no way intended that an order or orientation be inferred, in any respect. This holds for any possible non-express basis for interpretation, including matters of logic with respect to the arrangement of steps, operational flow, order of components, or orientation of components; plain meaning derived from grammatical organization or punctuation, and; the number or type of embodiments described in the specification.

[0080] While particular embodiments have been illustrated and described herein, it may be understood that various other changes and modifications may be made without departing from the spirit and scope of the claimed subject matter. Moreover, although various aspects ofthe claimed subject matter have been described herein, such aspects need not be utilized in combination. It is therefore intended that the appended claims cover all such changes and modifications that are within the scope of the claimed subject matter.

[0081] It is noted that the terms “substantially” and “about” may be utilized herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. These terms are also utilized herein to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue.

[0082] It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments described herein without departing from the scope of the claimed subject matter. Thus, it is intended that the specification cover the modifications and variations of the various embodiments described herein provided such modifications and variations come within the scope of the appended claims and their equivalents.

Claims

CLAIMS1. A system for evaluating an oscillatory motion regulating device comprising: a base comprising a plate body and an edge beam, wherein: the plate body has an upper surface, a lower surface opposite to the upper surface, and three or more edges, and the edge beam is extended from one of the three or more edges, the edge beam is configured to be mechanically attached to an oscillatory motion regulating device; an oscillation mechanism mechanically coupled to the upper surface of the plate body; a motion sensor operable to monitor an oscillatory motion of the base; and one or more processors configured to cause the motion sensor to generate an oscillatory motion data of the base.

2. The system of claim 1, wherein the oscillation mechanism is attached to the base around a center of gravity of the system.

3. The system of claim 1, wherein the oscillation mechanism has a spring stiffness proportional to a square of a target vibration frequency of the base.

4. The system of claim 1, wherein the motion sensor is an inertial measurement sensor, an angular sensor, a vision sensor, a light detection and ranging sensor, a thermal image sensor, an infrared sensor, an ultrasonic sensor, or a combination thereof.

5. The system of claim 1, wherein the system further comprises a wire mechanically coupled to the lower surface of the plate body of the base to prevent a vertical motion, a horizontal motion, or both of the oscillatory motion regulating device.

6. The system of claim 1, wherein the oscillatory motion data comprises translational position, velocity, acceleration, orientation, angular velocity, angular acceleration of the base, or a combination thereof.

7. The system of claim 1, wherein the system further comprises a bracket mechanically coupling the oscillatory motion regulating device to the edge beam of the base.

8. The system of claim 1, wherein the oscillatory motion regulating device comprises a flywheel actuator, a gimbal servo actuator, or both, and the system further comprises: a first angular sensor configured to monitor an angular velocity of the gimbal servo actuator; a second angular sensor configured to monitor a rotation speed of the flywheel actuator; or both.

9. The system of claim 1, wherein the system further comprises an outer frame, wherein the outer frame comprises a plurality of members to define an inner space, and wherein the base, the oscillatory motion regulating device, and the oscillation mechanism are arranged in the inner space.

10. The system of claim 9, wherein the oscillation mechanism comprises a first end and a second end opposite to the first end, the first end of the oscillation mechanism mechanically attached to the base, the second end of the oscillation mechanism mechanically coupled to one of the members of the outer frame.

11. The system of claim 9, wherein the plurality of members comprise a plurality of edge members and one or more internal members, and wherein the oscillation mechanism is mechanically coupled to one of the one or more internal members.

12. The system of claim 9, wherein the system further comprises a wire mechanically coupled to the lower surface of the plate body of the base, the wire configured to be mechanically connected to one of the plurality of members.

13. A method for evaluating an oscillatory motion regulating device comprising: causing, using one or more processors, an oscillatory motion regulating device to regulate an oscillatory motion of a base, the base comprising a plate body and an edge beam, wherein: the plate body comprises an upper surface, a lower surface opposite to the upper surface, and three or more edges, an oscillation mechanism mechanically coupled to the upper surface of the plate body of the base, a wire mechanically coupled to the lower surface of the plate body of the base, and the edge beam is extended from one of the edges, the oscillatory motion regulating device configured to be mechanically attached to the edge beam;generating, using a motion sensor, an oscillatory motion data of the base; and evaluating a performance of the oscillatory motion regulating device based on the oscillatory motion data of the base.

14. The method of claim 13, wherein: the oscillatory motion regulating device comprises a flywheel actuator, a gimbal servo actuator, or both; and the oscillatory motion regulating device regulates the oscillatory motion of the base through adjusting a rotation speed of the flywheel actuator, an angular velocity of the gimbal servo actuator, or both to generate a torque to the base.

15. The method of claim 13, wherein the evaluating the performance of the oscillatory motion regulating device further comprises: monitoring, using the motion sensor, a reference oscillatory motion data of the base in an absence of the oscillatory motion regulation from the oscillatory motion regulating device; and evaluating the performance of the oscillatory motion regulating device based on the oscillatory motion data and the reference oscillatory motion data.

16. The method of claim 13, wherein: the oscillation mechanism is attached to the base around a center of gravity of an assembly of the base and the oscillatory motion regulating device; and the oscillation mechanism has a spring stiffness proportional to a square of a target vibration frequency of the base.

17. The method of claim 13, wherein the oscillatory motion data comprises translational position, velocity, acceleration, orientation, angular velocity, angular acceleration of the base, or a combination thereof.

18. The method of claim 13, wherein: the base, the oscillatory motion regulating device, and the oscillation mechanism are arranged in an inner space of an outer frame; and the outer frame comprises a plurality of members to define the inner space.

19. The method of claim 18, wherein the oscillation mechanism is mechanically coupled to one of the plurality of members of the outer frame above the base.

20. The method of claim 18, wherein the wire is mechanically connected to one of the plurality of members of the outer frame below the base.

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