Motorized fitness wheel

Abstract

The systems and methods disclosed herein relate to motorized fitness wheels. The fitness wheel includes a wheel that rotates around an axle with two handles extending outward from each side of the wheel along the axis of rotation. In use, a user grasps the handles with both hands and rolls the wheel back and forth along the floor. The motor is configured to apply torque to the wheel in either a forward or backward direction to provide resistance or assistance and enhance exercise. A position sensor provides motor position information to a microcontroller. Based on the position information, the microcontroller dynamically controls the motor's output torque as a function of one or more torque trajectories. The torque trajectories define the motor's output torque over an exercise cycle as a function of spatial variables (e.g., wheel position) and / or time.

Description

[Technical Field]

[0001] The present invention relates to wheeled exercise devices, and more particularly to motor-assisted wheeled exercise devices used to accomplish core and upper body workouts. [Background technology]

[0002] 1.1 Related technologies Wheel-type exercise devices (also known as fitness wheels, exercise wheels, or abdominal exercisers) are often used to accomplish core and upper body workouts. Such devices typically consist of a wheel approximately 6 to 8 inches in diameter mounted on the center of a shaft, with static handles extending axially from each side of the wheel. The user grasps the device by the handles and rolls the wheel back and forth along the floor or other exercise surface.

[0003] The various types of wheel-type exercise devices are best categorized by their internal mechanisms, which ultimately affect the exercise experience.

[0004] The most common internal mechanism is simply a wheel-bearing-shaft assembly, which is convenient for mass production. Because the user is constrained to perform the exercise by resisting their own body weight, most beginners are unable to complete even a single repetition of the exercise and give up on starting to exercise. Meanwhile, advanced users have difficulty getting a sufficient workout and must compensate by performing many high-rep sets. Existing "abdominal exercisers" do little to correct these problems. Internal mechanisms that provide support and / or resistance to the user include bungee-assisted mechanisms, pneumatic mechanisms, spring-assisted mechanisms, and electric motors.

[0005] Bungee assist mechanisms are an imperfect solution to the above problem because they employ elastic cords, bands, or straps to provide assistance. (Note: In marketing materials, these are often referred to as "resistance bands," but their function is to assist (not "resist") the user in pulling back on the wheel. For the purposes of this invention, we refer to the force pushing against the forward motion as "assistance.") Bungee solutions sacrifice portability and ease of use by requiring additional equipment, especially if the user intends to modify the assistance as progress is made over time. Bungee cord solutions are very limited in the type and amount of assistance they provide. Aside from functional drawbacks, bungee cords can pose significant safety challenges if the user assembles the product incorrectly or lets their hands slip off the handles. If the user reasonably decides to break away during an exercise, large amounts of energy stored in the bungee cord can be dangerously released toward the user.

[0006] Pneumatic mechanisms vary the tire pressure to change the effective friction between the wheel and the ground, thus resisting inertia during exercise. However, pneumatic solutions only offer a limited range of resistance and can only provide a consistent amount of difficulty throughout each repetition of an exercise.

[0007] Spring-assisted mechanisms use an internal torsion spring in the center of the wheel to provide assistance. However, exercisers are limited in the amount of assistance they receive due to the material properties that define the internal spring. Additionally, the geometry of the torsion spring constrains the mechanism to roll in one direction from the exercise's rest position. As a result, only beginners benefit from the mechanism's assistive properties; experienced exercisers are unable to challenge their workouts more than they would with a standard bearing wheel.

[0008] Electric motors have been used to evolve fitness wheels beyond spring-assisted mechanisms. Motor-driven, geared fitness wheels with manual speed control have been developed. Some motor-assisted devices attempt to generate electricity by backdriving the motor as a means of providing exercise. Complementing the above features, the motor control can be adjusted to provide resistance to the user during exercise rollback, increasing exercise difficulty for more experienced users. Prior art motorized fitness wheel devices have not been commercially successful because they use basic motor control methods (e.g., constant speed control), resulting in a subpar exercise experience for users. None of the existing motor-assisted fitness wheels demonstrate the dynamic or real-time control of the motor, a feature of the present invention that enhances usability and promotes exercise progression (i.e., increasing difficulty over time). Furthermore, existing motor-assisted fitness wheels lack effective and practical safety mechanisms that can prevent the motor from operating when exercise is stopped. Finally, existing motor-assisted fitness wheels lack intuitive and engaging user interfaces.

[0009] It is with respect to these and other considerations that the disclosure made herein is presented. Summary of the Invention [Means for solving the problem]

[0010] According to one aspect of the present disclosure, a motorized exercise wheel is provided for performing an exercise having at least one cycle, in which a user rolls a wheeled mechanism (which we will refer to as a "wheel," understanding that it may have two or more wheels) in a forward direction along a surface from a substantially stationary position to an extended position, and then rolls the wheel in a backward direction along the surface from the extended position to a stationary position. The motorized exercise wheel includes a wheel assembly including a ground-contacting component configured to rotate about an axle in either a forward or backward rotational direction to contact the surface and thereby roll along the ground in either a forward or backward direction. The motorized exercise wheel also includes first and second handles configured to receive each hand of a user, the first and second handles extending outward from respective sides of the wheel assembly. The motorized exercise wheel also includes an electric motor coupled to the wheel assembly and configured to apply an output torque to the ground-contacting component in either a forward or backward rotational direction. The motorized exercise wheel also includes a microcontroller that includes one or more processors and is configured to control the output torque of the motor. The motorized exercise wheel also includes a sensor in communication with the microcontroller and configured to determine a movement variable of the exercise wheel. The motorized exercise wheel also includes a non-transitory computer-readable storage medium accessible by the microcontroller. Additionally, the microcontroller is further configured to control the output torque of the motor over an exercise cycle as a function of the determined movement variable.

[0011] According to a further aspect, a method of operating a motorized exercise wheel to perform an exercise is disclosed. The exercise involves at least one cycle in which a user rolls the wheel in a forward direction along a surface from a substantially stationary position to an extended position, and then rolls the wheel in a backward direction along the surface from the extended position to a stationary position, thereby completing the cycle. The wheel includes a wheel assembly including a ground-contacting component, an electric motor coupled to the wheel assembly, first and second handles extending from the wheel assembly and manipulated by a user, and a microcontroller. The method is executed by the microcontroller and includes determining, using a sensor, a motion variable relating to movement of the exercise wheel during exercise, the motion variable being determined using the sensor throughout at least one cycle. The method also includes determining a target output torque of the electric motor based at least in part on the determination of the motion variable. The method also includes controlling the output torque of the electric motor over the exercise cycle as a function of the target output torque.

[0012] These and other aspects, features, and advantages can be understood from the following description of specific embodiments of the invention, as well as from the accompanying drawings and claims. [Brief explanation of the drawings]

[0013] [Figure 1A] FIG. 1 is a perspective view of an exemplary motorized fitness wheel, according to one embodiment. [Figure 1B] 1B is a cross-sectional view of the fitness wheel of FIG. 1A taken along line AA, according to one embodiment. [Figure 2] FIG. 1 is a block diagram illustrating the interconnected and cooperating mechanical, electrical, and software components of a motorized fitness wheel, according to one embodiment. [Figure 3] FIG. 1 is a block diagram illustrating an exemplary configuration of electronics for a motorized fitness wheel, according to one embodiment. [Figure 4] This animation, generated by performing a numerical simulation of an actual exercise using a fitness wheel, illustrates one possible user position at the start of an exercise session, according to one embodiment. [Figure 5] This animation, generated by performing a numerical simulation of a real exercise using a fitness wheel, illustrates one possible user position during early extension, according to one embodiment. [Figure 6] This animation, generated by performing a numerical simulation of a real exercise using a fitness wheel, shows one possible user position at full extension, according to one embodiment. [Figure 7] This animation was generated by performing a numerical simulation of a real exercise using a fitness wheel, showing one possible user posture during flexion, according to one embodiment. [Figure 8] This animation was generated by performing a numerical simulation of a real exercise using a fitness wheel, according to one embodiment, showing one possible user posture as they flex and return to (approximately) the starting position. [Figure 9] 9 illustrates an example of fitness wheel displacement in the x-direction during exercise generated in the simulations shown in FIGS. 4 through 8, according to one embodiment. [Figure 10] 4-8 show examples of torques applied by a simulated fitness wheel for three cases during exercise: (1) no assistance, 0 N·m; (2) maximum assistance, −6 N·m; and (3) maximum obstruction, +6 N·m, according to one embodiment, as input to the simulations shown in FIGS. [Figure 11]FIG. 1 shows an example of hip torque during exercise for three different cases: (1) no assistance, (2) maximum assistance, and (3) maximum resistance, generated in the simulations shown in FIGS. 4 through 8 using a fitness wheel, according to one embodiment. [Figure 12] FIG. 1 shows an example of shoulder torque during exercise for three different cases: (1) no assistance, (2) maximum assistance, and (3) maximum resistance, generated in the simulation shown in FIGS. 4-8 using a fitness wheel, according to one embodiment. [Figure 13] 1 shows three related graphs illustrating an example assist motor torque curve, corresponding wheel speed measurements, and distance measurements for an example exercise cycle, according to one embodiment. [Figure 14] 10 shows two graphs illustrating exemplary resistance torque curves, according to one embodiment. [Figure 15] 1 shows three graphs illustrating exemplary braking torque curves, according to one embodiment. [Figure 16] 1 illustrates an embodiment of a structure for transmitting wrist torque to a user's forearm, according to one embodiment. [Figure 17] 1 illustrates an embodiment of a structure for transferring wrist torque to the floor, according to one embodiment. [Figure 18] 1B is a flowchart of an embodiment of a method for operating the motor controller of the fitness wheel of FIG. 1A, according to one embodiment.

[0014] It is noted that the drawings are illustrative and are not necessarily to scale. DETAILED DESCRIPTION OF THE INVENTION

[0015] 2.1 Overview By way of overview and introduction, the systems and methods disclosed herein relate to motorized fitness wheels. Figure 1A is a perspective view of an exemplary fitness wheel 100 according to one embodiment. Figure 1B is a cross-sectional view of fitness wheel 100 taken along line AA shown in Figure 1A, with the top half of the fitness wheel cut away to reveal the internal components of the fitness wheel.

[0016] As shown in FIGS. 1A and 1B, the hardware of fitness wheel 100 consists of electric motor 9 mounted inside wheel 1. Radially inward of the motor is bearing assembly 10, which is configured to allow the motor to provide torque between a rotating portion 14 of the wheel and a stationary axle shaft 15 coupled to handle 7. The outer radius of the wheel includes ground-contacting elements 21 configured to roll along the ground. Handles 7 extend outward from each side of the wheel, generally along the wheel's axis of rotation, and are intended to be grasped by a user during use. The wheel is closed by two hubcaps 8, which house internal components including battery 11, electronics 12, electric motor 9, and the like.

[0017] A user interface is provided on the outside of one of the hubcaps and comprises a physical interface including a rotatable difficulty selection rotary dial 4, a Bluetooth button 5, and a power button 6. The fitness wheel 100 also includes a visual indicator, such as an exercise difficulty display 3, which displays the difficulty level selected by the user using, for example, the difficulty selection rotary dial 4. The visual indicator also includes an LED 2, which is used to provide feedback to the user regarding the status and progress of the exercise, making the exercise experience more engaging and enjoyable.

[0018] Figure 2 is a block diagram illustrating the interconnected and cooperating mechanical, electrical, and software components of fitness wheel 100, which are configured to provide real-time dynamic control of the motorized fitness wheel in response to user motion, according to one embodiment. Figure 3 is a block diagram illustrating an exemplary configuration of the electronics of fitness wheel 100, according to one embodiment.

[0019] Fitness wheel 100 offers a unique advantage in that it provides both assisted exercise for beginners and resistive exercise for advanced athletes, allowing both athletes to maximize their available time and energy. Fitness wheel 100 is configured to allow a user to interact with the device both physically (arrow 201) by providing input through a physical interface comprising electromechanical hardware, and digitally (arrow 202) by providing input through a digital interface (e.g., a software application running on a smartphone, tablet, personal computer, etc.). Both types of input can be received and processed using microcontroller 210 and used to define the type and difficulty of the exercise, often given the user's strength, fitness, and / or experience level. For example, a user can select a difficulty level using rotary difficulty selection rotary dial 4, which is received at microcontroller 210 (arrow 201). Similarly, a user can select a difficulty level and / or exercise type using smartphone application 250, which is received at microcontroller 210 via a wireless communication connection (e.g., Bluetooth) (arrow 202). In response to user input sent to the microcontroller on board the fitness wheel, the microcontroller initiates a motor feedback loop (arrow numbered 203) as a function of the user input, controlling the motion of the fitness wheel and thereby facilitating exercise.In one embodiment, the motor feedback loop subsystem is configured to operate as follows: sensor 215 measures and relays real-time current data measured from the motor to microcontroller 210; microcontroller 210 calculates the torque-producing portion of the current and identifies any discrepancy between the measured torque-producing current and the target torque-producing current; microcontroller 210 generates correction information as a function of the discrepancy, which is sent as a new voltage command (as a duty cycle) to motor electronics 220, which drives motor 9. As further described herein (see 2.4.2), the "target" torque output depends on specific data derived from the aforementioned user input, among other parameters. Simultaneously, a battery management loop (arrow 204) is provided to ensure that the battery voltage is properly managed, including indicating to the user when the battery needs charging. Alternatively, battery management electronics 230 may control the battery without any additional software input from microcontroller 210. In one embodiment, battery 240 may comprise a single or multiple battery units, referred to herein simply as "batteries," and is managed by electronics, with microcontroller 210 reading the battery voltage for control purposes and battery manager / electronics 230 charging the battery whenever it is plugged in for charging and needs to be charged. The battery provides voltage and current to electronics 220. As shown in FIG. 2, microcontroller 210 may also be configured to output information to a user's digital interface (arrow 206), illustratively via an on-board user interface including rim-mounted LEDs 2, or via a physical interface (arrow 205), such as difficulty display 3.

[0020] 2.2 Mechanical section 2.2.1 Internal mechanism In one embodiment, fitness wheel 100 comprises an outrunner motor 9, in which a stator is the hub of the motor and a rotor (moving part) is on the outside, surrounding the stator. The motor windings are connected to a motor drive (not shown), which energizes the motor. While the illustrated embodiment of FIG. 1B shows motor 9 directly coupled to the rotating part of wheel 1, it should be understood that this is exemplary and not limiting, as the motor can be coupled to the wheel through a suitable transmission (e.g., gears, belt, etc.).

[0021] 2.2.2 External Interface In one embodiment, physical user interface components 255 are located on a hubcap 8 on one side of the fitness wheel. Various features and functionality of the fitness wheel 100 are controlled by the microcontroller 210 as a function of user input provided using the physical tactile components of the interface 255, including the difficulty level selection rotary dial 4, the Bluetooth button 5, and the power button 6. As will be appreciated, the Bluetooth button connects the fitness wheel 100 to a remote device, such as the user's smartphone, via a wireless communication interface (e.g., Bluetooth). A digital exercise interface application running on the smartphone allows the user to interact with the fitness wheel 100 via the smartphone.

[0022] In one embodiment, the microcontroller 210 is configured to display a value representing the selected exercise difficulty on the difficulty display 3. As shown, the difficulty display 3 may comprise various numbers (displayed as 5 4 3 2 1 0 1 2 3 4 5) on the fitness wheel's hubcap. Illustratively, when a difficulty level is selected using the selection rotary dial 4, the microcontroller may cause the selected number to illuminate either red (to the left of zero, signifying a difficult difficulty) or green (to the right of zero, signifying an easy difficulty). While the power function may be controlled automatically via a software application, a mechanical power button 6 may be provided to give the user control and reliability of the fitness wheel 100's status. In one embodiment, rather than integrating Bluetooth into the power button for dual functionality, a Bluetooth control button 5 is provided as a separate button to avoid unnecessary power cycling. In one embodiment, the Bluetooth button may be omitted, and a mobile device may connect to the fitness wheel via Bluetooth Low Energy (BLE). This feature is particularly beneficial in public gyms, personal training, or physical therapy facilities, as users may be able to walk up to the fitness wheel and quickly establish communication.

[0023] Other components of the interface 255 may be visual status communication devices (LEDs 2 on the wheel rim) and tactile feedback (motor control signals that produce movement that the user can feel in the handlebars). Another interactive user interface component may be an exercise digital interface 250 (i.e., a smartphone application) running on the user's smartphone and configured to wirelessly transmit user input and control commands to the microcontroller 210.

[0024] The LEDs 2 attached to the wheel rim can be controlled by the microcontroller 210 to inform the user about various states of the wheel (e.g., low battery, completed iteration, Bluetooth connection status, etc.) through different colors, patterns, and animations (see, e.g., Table 1 below). Table 1. LED Feedback

[0025] [Table 1]

[0026] In one embodiment, LED2 is specifically positioned on the rim of the wheel to maximize its presence in the user's field of view. In one embodiment, as described further herein, the fitness wheel can be configured to provide haptic feedback via a "flutter" command (see 2.4.2.4) to specify wheel state. In one embodiment, smartphone application 250 can also be configured to operate as a digital interface in conjunction with the fitness wheel to communicate exercise progress as well as health statistics in great detail.

[0027] 2.3 Electrical section In one embodiment, the electronics that are mounted on and control the operation of fitness wheel 100 are contained on two circuit boards. It is understood that the two boards may be combined into one or split into more than two boards for any reason, including improved packaging or cost reduction.

[0028] 2.3.1 Microcontrollers 3 and described above, in one embodiment, microcontroller 210 receives user input via selection dial (arrow 301) and digital interface 250 (arrow 302) and controls the operation of the fitness wheel accordingly. Similarly, the microcontroller can be configured to output information related to the operation of the fitness wheel via LED2 (arrow 305) and digital interface 250 (arrow 306).

[0029] A microcontroller 210 connected to the motor 9 is configured to control the motor torque during exercise. References herein to a "microcontroller" may refer to either: a) a single microcontroller or microprocessor that performs one or more functions; b) multiple microcontrollers or microprocessors that collectively perform various functions; or c) a combination of microcontrollers or microprocessors that collectively perform various functions. It should also be understood that references to a microcontroller may encompass other types of custom or preprogrammed logic devices, circuits, or processors, such as programmable logic controllers (PLCs), calculators, software, or other circuits (e.g., ASICs, FPGAs) configured with code or logic to perform assigned tasks.

[0030] As shown in FIG. 3 , in one embodiment, the microcontroller 210 is part of a motor drive circuit identified by the connection labeled 304. More specifically, the microcontroller's motor controller module 214 controls a two- or three-phase bridge, which in turn controls the voltage / current supplied to a brushed or brushless motor 9. A brushless motor may be preferred for smoother operation. The motor drive circuit also includes a feedback loop. As a user exercises using the fitness wheel, a feedback loop comprising a combination of sensors (e.g., Hall sensors, magnetic sensors, current sensors, and encoders) relays motor position and current data to the control microcontroller unit 210. In one embodiment, the motor drive circuit feedback loop may include a current sensor 270 with signal conditioning. This feedback loop is implemented to ensure that the motor follows the correct torque profile along the exercise path.

[0031] 2.3.2 Batteries and Battery Management Chips In a preferred embodiment, the electronics is powered by a battery 240 managed by a battery management electronic component (230, FIG. 2). In one embodiment, the microcontroller 210 comprises two microprocessor units: a motor controller 214 and a supervisor controller 212. The supervisor controller 212 communicates with the motor controller 214 and with peripheral devices including user interface devices (e.g., LED driver 280 for driving LED2), among other electronic hardware components.

[0032] In one embodiment, a motor controller 214 manages control of the device's brushless DC (BLDC) motor 9. Additionally, the motor controller controls the brushless three-phase motor 9 utilizing a gate drive and a three-phase bridge 260. A supervisor controller 212 processes user input from peripherals such as a rotary dial 4 or input received via Bluetooth from a smartphone application 250. In some embodiments, the supervisor controller 212 communicates with the motor controller via a bus (such as an SPI bus) that communicates information such as requested state changes or exercise measurements. However, it should be noted that this architecture is only an example and that many relevant alternatives are possible, e.g., a single MCU could be used for both motor control and the user interface, and different motor types (e.g., induction, brushed DC, variable reluctance, etc.) could be used without departing from the scope of this disclosure.

[0033] To properly control the motor 9, one or more sensors (e.g., sensor 215, FIG. 2; sensors 270, 275, FIG. 3) can be used to collect information for the microcontroller 210 and its software regarding one or more movement variables. The information measured by the sensors and used by the microcontroller to control the motor can include position information, which represents spatial and / or temporal variables (e.g., displacement, velocity, acceleration, and the like) related to the movement of the fitness wheel 100. For example, in one embodiment, the position sensor 275 can comprise a rotary encoder used to measure the angle of the motor 9. In one embodiment, the position sensor 275 can comprise a Hall-effect sensor or a magnetic sensor that measures the motor angle in phase. From this position information, the motor angle, speed (number of rotations over time), and acceleration (e.g., rate of change of speed) can be calculated by the motor controller 214 and used to commutate the motor and control the exercise. It should be understood that a Hall-effect sensor, a magnetic sensor, or any other suitable position feedback sensor can additionally or alternatively be used for this function. It should be understood that reference to a position sensor is not limited to a sensor device and can include an estimator configured to estimate a given variable based on other measured information. Information collected by the sensor and used to control the electric motor can also include an electric motor output variable, such as torque. A sensor that can be used to measure torque output can be, for example, a current sensor (e.g., sensor 270) configured to measure the torque-producing current of the electric motor, which is representative of torque output.

[0034] 2.3.3 Power electronics 3, the microcontroller 210, and in particular the motor controller 214, can use pulse width modulation (PWM) peripherals to send switching commands to a three-phase inverter comprising three half-bridges 260 using field effect transistors (FETs, not shown), which modulates the voltage to the motor to control it.

[0035] 2.4 Software In the motor feedback loop (connection 203 in FIG. 2 and connection 304 in FIG. 3), software running in microcontroller 210, and particularly motor controller 214, configures microcontroller 210 to generate a "target" torque command (which can be expressed as a fraction of the torque-producing current). The torque command controls the output torque of the motor drive and thus defines the exercise experience for the user. By defining the torque as a function of certain variables (see 2.4.2.2), the resulting characteristic motor response serves to challenge the user to exercise in different ways.

[0036] 2.4.1 Motor Control In one embodiment, the output torque (τ) of a brushed DC motor drive can be expressed as: τ=I a k T , Equation 1.1 Here, I a is the armature current, k T is the torque constant (motor dependent). In the case of vector control of a three-phase motor, I a is the DQ current (I q ) is the torque-producing component of I in Equation 1.1. a The dimensions include: τ max =I a , max k T , τ min =-I a,max k T , Equation 1.2.1~2 where I a,max It is important to note that I is the maximum operating torque producing current and is dependent on the limitations of the electric motor 9, electronics 220, and battery 240. a The size of I a,max or -I a,max Since it may not exceed I a is always I a,max This results in a fraction of the following relationship:

number

[0037] The torque-generating current is expressed as a non-dimensional form (I * a ) and manipulating the variables allows for more precise numerical representations used by the microcontroller / software 210. By controlling the motor using the DQ formulation [1], the motor controller 214 can calculate the current I q The motor torque can be commanded by commanding the components (I q →I a An angle sensor (encoder, Hall effect, magnetic, etc.) is used to calculate the D and Q directions to align the currents.

[0038] 2.4.2 Structure In one embodiment, different algorithms for controlling the motor 9 are assembled to aid in the development and execution of programmed exercises through selective combination of various algorithms. An "exercise" is most generally defined by information such as, but not limited to: 1. The user's "posture" or sequence of movements determined from one or more measured parameters: how far the user moves the wheel and then returns it; whether the movement is forward / backward or side-to-side; whether the user is kneeling or standing, etc. 2. "Trajectory" - in the context of this disclosure, this refers to the torque command (or current) in an exercise wheel. Note that torque trajectories are not necessarily static - wheel torque can, and usually does, vary with respect to one or more spatial / temporal variables, including, for example, displacement, velocity, time, and the like. A trajectory (torque curve of a rep) is constructed from one or more "profiles" and "events." Trajectories are typically implemented algorithmically by combining profile equations and conditions and parameters measured by the wheel. As non-limiting examples, trajectories can be represented in the form of a mathematical table, one or more parameterized equations, and the like, or a combination of the foregoing. a. A "profile" is a function (also called a "curve") that relates torque to a measured parameter such as speed, position, or time. For example, a linear spring could be represented as a profile of torque as a function of distance from an original position. A trajectory can be one continuous profile, or a series of profiles strung together, e.g., a linear spring for some distance (first profile), followed by a non-linear spring for another distance (second profile). By way of non-limiting example, a profile can be represented in the form of a mathematical table, one or more parameterized equations, and the like, or a combination of the foregoing. b. An "event" is a change in torque or profile triggered by some condition. For example, a boost in torque that helps assist the user in returning to a starting position can be an event. Also, a transition between profiles (to avoid abrupt torque changes) can be an event. Events can be used to convey information to the user (e.g., haptic flutter). Events can be juxtaposed with profiles or other events, or superimposed on a profile. For example, haptic flutter (2.4.2.4) can be superimposed on a profile.

[0039] These and other algorithms for controlling the motors may be stored in a non-transitory computer-readable storage medium (not shown) accessible to the microcontroller for execution during use. In one embodiment, the digital interface 250 may also be configured to store exercise, trajectory, profile, event, and other such motor control algorithms, and to provide selected algorithms to the microcontroller for local storage and execution.

[0040] The user's posture plays a vital role in dictating which muscle groups are activated throughout the exercise, regardless of the trajectory or event. In one embodiment, the training software aligns the trajectory with the suggested user posture (movement), so the user can perform the recommended exercise (usually by performing "reps").

[0041] 2.4.2.1 User posture Below we consider user posture and how it is taken into account in motor control.

[0042] For illustrative purposes, a computer simulation of the fitness wheel 100 and a user was used to generate the "tin man" exercise simulation and animation depicted in Figures 4-8. Representative body part lengths, masses, and joint angles correspond to those of a real human subject. The subject was equipped with visual targets and recorded with a camera while using the exercise wheel. The joint angles used in the simulation were obtained from analyzing video footage of the human subject performing the exercise. Figures 4-8 show the user's position in the 3D animation generated by running the exercise simulation using the joint angles based on the video analysis described above. Also shown in Figures 4-8 are dashed lines indicating the paths of the user's hips and shoulders and the center of the wheel during the exercise.

[0043] When the fitness wheel 100 is not activated, the muscle-generated torques acting at the subject's shoulder, hip, and wrist joints 405, 410, 415 during exercise arise primarily from resisting the pull of gravity. These torques vary depending on the user's posture during exercise. Furthermore, when the fitness wheel is activated, the actuation torques present at the subject's joints can be varied by the fitness wheel. The fitness wheel can either assist or hinder (resist) the user's movement.

[0044] Muscles can only generate tension in their tendons, i.e. they can only pull. In the body, different muscle groups are arranged antagonistically to generate positive and negative torques that act at the subject's joints. Thus, as the sign of the torque changes from positive to negative, the dominant muscle group being used changes, for example from the back muscles to the abdominal muscles as an exercise is initiated.

[0045] The displacement (d) of the fitness wheel center during exercise is plotted in Figure 9. This plot can be used to correlate the wheel position (and user posture) during exercise.

[0046] As an example, the torque (τ) that the fitness wheel motor can apply to the wheel is plotted in FIG. 10. Specifically, FIG. 10 illustrates the torque applied by a simulated fitness wheel for three cases: (1) no assistance, 0 N·m (represented by a square); (2) maximum assistance, −6 N·m (represented by a circle); and (3) maximum obstruction, +6 N·m (represented by a triangle). Note that the applied torque also appears as a torque at the user's wrist, with the opposite sign. Furthermore, note that while this example shows a constant torque being applied, the torque applied by fitness wheel 100 under the control of microcontroller 210 can vary anywhere between the values of maximum assistance and maximum obstruction during exercise.

[0047] If the fitness wheel 100 is not activated, the motor applies a torque of 0 N·m; otherwise, the motor can apply anywhere between a positive full torque and a negative full torque. In one embodiment, the maximum torque is between 6 N·m and 16 N·m. In the simulations presented herein, the maximum torque was selected to be only 6 N·m; therefore, the torque in the plot ranges from +6 N·m to −6 N·m, depending on programming. The applied torque of the motor results in opposing reaction torques at the fitness wheel handgrips, −6 N·m and +6 N·m, respectively. In addition to the reaction torque, a horizontal force, e.g., Fx = (−6 N·m / wheel radius), is generated at the wheel-floor interface. The horizontal force also appears at the fitness wheel handgrips and acts on the subject.

[0048] Both torque and force at the fitness wheel hand grips change the joint torques that will be produced by various muscle groups. Varying the radius of the wheel changes the ratio of force to torque at the hand grips. A smaller radius will result in more force for the same torque.

[0049] Figure 11 plots the hip joint torque generated by the muscle groups during the simulated exercise. Three curves are plotted: the middle curve when the applied motor torque is 0 N m, the top curve when the applied motor torque is -6 N m, and the bottom curve when the applied motor torque is +6 N m. For this simulation, the wheel radius was set to 4 inches (8 inch diameter).

[0050] As the curve crosses the zero torque level, the dominant muscle group changes from the back muscles to the abdominal muscles, so at the beginning and end of the exercise the motor torque can be adjusted to modify the exercise for the back muscles, while midway through the exercise the motor torque can be adjusted to modify the exercise for the abdominal muscles.

[0051] Many different modifications are possible with the microcontroller 210 selectively adjusting the motor torque: at the extremes of the exercise cycle (i.e., when the back muscles are the dominant muscle group), back exercise could be minimized or maximized, and separately, but during the same exercise sequence, mid-exercise (i.e., when the abdominal muscles are the dominant muscle group), abdominal exercise could be maximized or minimized.

[0052] As can be seen, minimizing both back and abdominal exercises may make the exercise easier (or perhaps even possible) for beginners; maximizing both back and abdominal exercises may make the exercise the most challenging and beneficial for experienced users; and minimizing only back exercises may be beneficial for users with back concerns.

[0053] In addition to minimizing or maximizing, in one embodiment, the actuation joint torque may be "leveled." More specifically, the microcontroller 210 may be configured to selectively adjust the motor torque to keep the actuation joint torque as close as possible to a set level that is challenging for various users. Thus, users may obtain as much benefit as possible from each cycle of exercise.

[0054] Figure 12 plots the shoulder joint torques that would be generated by the muscle groups during the simulated exercise. Three curves are plotted: the middle curve when the motor torque is 0 N m, the top curve when the motor torque is -6 N m, and the bottom curve when the motor torque is +6 N m.

[0055] In addition to being minimized, maximized, and equalized (as is the case with the actuating hip torque), the actuating shoulder torque can potentially be used as a constraint to limit stress on muscle groups associated with positive and negative actuating shoulder torque.

[0056] Generalizing, the microcontroller 210 can be configured to selectively adjust motor torques to keep hip, shoulder, and wrist actuation joint torques within limits while optimizing exercise benefit for a given user.

[0057] Human subjects tend to adapt to a given physical task that minimizes their muscular energy expenditure. This adaptation takes some time, so it is expected that any program changes will require a period of adaptation by the user.

[0058] 2.4.2.2 Profiles A profile is a component of the torque trajectory that the fitness wheel 100 follows throughout an exercise. Broadly speaking, a profile can define the torque applied by the motor 9 as a function of movement variable data, which can include data determined by position (e.g., displacement, velocity, etc.) or data determined by time.

[0059] The profile may include a spatial profile that defines the torque-producing current of the electric motor as a function of wheel position, and therefore its torque output. As mentioned above, the wheel position input data may be measured using a position sensor (e.g., 275). In one embodiment, the wheel position input data may be differentiated with respect to time (m times) and the resulting quantity raised to a power (n) to obtain different torque curve variations. An overall gain factor (α) is applied to scale the torque curve, resulting in a family of strengths for a given characteristic torque curve:

number

[0060] Equation 2.1 can be expanded (Equation 2.2) to more precisely show the variables and calculations required to obtain the appropriate torque-producing current, and therefore output torque, to be commanded.

number

[0061] The "max" term in the denominator is determined empirically. The numerator in Equation 2.2 is based on sensor data measured throughout the exercise, while the denominator (e.g., maximum position, maximum speed, etc.) is preferably defined before the exercise begins. There are two main ways to provide this information to the microcontroller 210 software: it can be manually entered by the user through a user interface (e.g., via the fitness wheel's 100 digital interface 250 or physical interface 255) (or indirectly calculated from the manual input); and / or it can be programmed into the microcontroller as a default (e.g., a maximum position resulting from an average human rollout distance, a maximum speed resulting from the safest exercise speed, etc.). Data can be collected automatically while the wheel is in use, and an upper limit for that period can be determined.

[0062] Each characteristic torque curve (defined by the constants m and n) is represented by a function β(α,x), where position (x) drives the curve and a scaling factor (α) amplifies the curve. The resulting dimensionless value is the motor's specific maximum torque-producing current, I a,max Scaled in physical units I q The desired torque-producing current at (α,x) is obtained: I q (α,x)=β(α,x)I a,max Equation 2.3

[0063] In one embodiment, the curves generated using the above formulation can be designed to mimic physical phenomena. Table 2 below lists three example spatial profiles, their respective variables, and governing equations. In the example in the table below, the profiles are configured to mimic the properties of a spring and damper. A scaling factor (α) is shown to represent the spring constant (k) and damping constant (c), which are also bounded to the interval [-1, 1]. Table 2. Exemplary position-dependent profiles (positive x direction)

[0064] [Table 2]

[0065] Similar to the position-based profiles, a set of time-based profiles can be generated by defining the torque-producing current as a function of time:

number

[0066] Equation 3.1 can be expanded and rearranged to give the maximum possible torque-producing current (I a , max ) as a fraction of the torque-producing current (I a ) can be solved for:

number

[0067] A temporal profile (torque as a function of time) can be applied, for example, in a situation where a user is guided through a paced exercise.

[0068] 2.4.2.3 Trajectory The human body is composed of a complex system of muscles. A simple torque profile relationship may not always be optimal for consistent muscle activation throughout an exercise as motivated by Section 2.4.2.1 above. At other times, the torque profile may prevent the desired exercise experience from being achieved. Thus, in one embodiment, multiple torque profiles (and / or events) can be combined to optimize the exercise for the user. Trajectories constructed from combinations of torque profiles and events can be preprogrammed into the microcontroller 210 or transmitted to the microcontroller via the digital interface 250.

[0069] In one embodiment, the microcontroller 210 can be configured to use a linear combination of the aforementioned torque profiles and construct a new complex profile through the use of a weighting function:

number

[0070] In one embodiment, torque profiles can be further combined piecewise to give different characteristics to specific aspects of the exercise path. For example, a spring model can be used to smoothly increase torque in the first 10% of the rollout, while an inverse damper model's beginning of the profile prevents the user from experiencing too much sudden torque.

[0071] Because humans are adept at detecting small force perturbations, the feel of the wheel is important. A key aspect of the exercise experience achieved by the microcontroller is developing a torque profile that feels smooth and contributes to the exercise. To generate a smooth profile, the microcontroller 210 is configured to "stitch" from one profile to the next without torque discontinuities. It should be understood that the foregoing is an exemplary methodology implemented by the microcontroller to combine torque profiles to generate complex trajectories and provide a smooth experience, and that variations can be used to achieve similar results that would fall within the scope of the disclosed embodiments. It should be understood that, additionally or alternatively, the exemplary steps of generating simple profiles or complex trajectories by combining or adjusting profiles, events, and the like can be performed by other devices in communication with the microcontroller, such as the digital interface 250, or another remote computing device in direct or indirect communication with the microcontroller 210.

[0072] For example, Table 3 below lists two exemplary simultaneous combination trajectories, including their respective variables and governing equations. Trajectory example (positive x direction)

[0073] [Table 3]

[0074] 2.4.2.4 Events As previously mentioned, an event is a specific event, i.e., a supplemental wheel torque control function, selectively applied by microcontroller 210 on a trajectory in response to detecting a specified condition along the trajectory. Similar to a torque profile, a supplemental torque event (or simply "event") defines a target output torque value as a function of motion variables, such as spatial and / or temporal variables. However, it is intended that the event be applied for a portion of an exercise cycle.

[0075] In one embodiment, boost events that selectively increase torque can be integrated onto the original exercise trajectory, for example, in situations where the user may need an extra kick of torque to progress along the exercise. While the details of boost implementation may vary depending on the type of exercise, all boost variations typically share the same characteristics: one or more threshold conditions required to initiate the boost; an increase in torque from the current torque to a target boost torque, followed by a decrease back to the original profile of the exercise.

[0076] For example, the microcontroller can be configured to initiate a boost event when it determines that the user has passed a certain position threshold in the exercise's outward movement and when the user passes a specified speed threshold. When both conditions are met, a boost event is applied on top of the basic assist torque profile. Illustratively, as shown, the boost event increases torque to a target torque value as the wheel speed approaches zero, which is defined as a function of exercise difficulty. On the way back to the rest position of the exercise, the torque gradually returns to the nominal profile. The boost provides the user with an additional push backward to initiate the return to the original position.

[0077] FIG. 13 illustrates three related graphs of an example assisted torque trajectory / curve implemented by the fitness wheel 100 during an example complete exercise cycle. The trajectory comprises a combination of profiles and events. A first graph 1305 illustrates percent motor torque over time, a second graph 1310 illustrates wheel speed over time, and a third graph 1315 illustrates distance covered over time. The wheel speed vs. distance graph represents spatial and temporal variables measured during the user's execution of the exercise cycle. The percent motor torque graph illustrates the percentage of motor torque output corresponding to the distance vs. speed curve. Positive torque values in this plot represent torque that opposes the wheel's positive forward motion and assists its return motion (assistance in the exercise). At the top of the first graph 1305 are a series of labeled modes (A) through (J) that indicate the operating modes implemented by the microcontroller 210. Mode transition times in graphs 1310 and 1315 are marked (1) through (9). As shown, the wheel starts in Standby mode (A), where microcontroller 210 waits for movement. When microcontroller 210 detects that the wheel's rotational speed exceeds a threshold, e.g., 0.03 revolutions per second in either direction (marked (1) in graph 1310), microcontroller 210 transitions to "Deadband" mode (B). In Deadband mode, no torque is applied, and microcontroller 210 waits to see how far the wheel can be moved. If the user stops moving, microcontroller 210 transitions back to Standby mode (A) and resets. If the user continues moving in the same direction, e.g., past the 0.2 revolution (2) position, microcontroller 210 enters Crossover mode (C). In crossover mode (C), the microcontroller controls the motor torque to increase linearly as the wheel travels a specified distance, e.g., from 0.2 revolutions to 0.4 revolutions.When the wheel distance passes the 0.4 revolution (3) position, the microcontroller 210 enters "Profile" mode (D). In Profile mode, the microcontroller creates a profile, for example, a profile that defines torque as a quadratic function of position (e.g., Torque_Current=overall_gain). * quadratic_gain * Set the motor torque based on (position^2) / max_position^2), vary overall_gain for the selected mode (0.8 in the example shown in Figure 13), quadratic_gain=1.0, and max_position=2.0 (corresponding to a value appropriate for a tall adult). * This quadratic function continues until max_position=1.5 revolutions, simultaneously dropping the speed below a threshold, e.g., 0.05 revolutions per second (4). The deceleration signals the microcontroller 210 that the user is nearing the end of the exercise. At this point, the microcontroller 210 can increase the torque by a specified amount, e.g., 20%, to provide additional assistance to the user as they begin to move backward to the starting position. To achieve "Boost," the microcontroller 210 enters Boost Ramp up mode (E) and linearly increases the torque from its current value to 120% of its current value, e.g., as a linear function of decreasing speed from 0.05 revolutions per second to 0.005 revolutions per second. As shown in FIG. 13, at this point the maximum allowable torque is exceeded, so the torque saturates at its maximum value. When the wheel speed drops below a set value, illustratively 0.005 revolutions per second (5), the microcontroller 210 transitions to Boost Ramp Down mode (F). In Boost Ramp Down mode (F), the torque is linearly scaled between the peak value and a "rejoin" value, at which point wheel movement reverts to the original quadratic torque curve. The rejoin point is 0.75 *max_position=1.5 revolutions (6). At this point, the microcontroller 210 transitions back to the profile mode (G) described above. When the wheel position crosses downward, for example, 0.4 revolutions (7), the wheel transitions back to the crossover mode (H) described above. When the wheel position drops below, for example, 0.2 revolutions (8), the wheel transitions back to the deadband mode (I) described above, where no torque is output by the wheel motor. In deadband mode, the microcontroller waits for the speed to drop below, for example, 0.01 revolutions per second (9), at which point it resets back to standby mode (J). This completes one full cycle of exercise.

[0078] FIG. 14 includes two graphs illustrating exemplary resistance torque curves. In particular, the bottom graph in FIG. 14 represents the distance (in revolutions) traveled by the fitness wheel 100 versus time for one repetition (or "cycle") of exercise. The top graph in FIG. 14 illustrates the percentage of applied motor torque corresponding to the distance versus time curve. Negative torque values in this plot represent torque pulling in the direction of the wheel's motion (resistance to the exercise). FIG. 14 illustrates that torque increases and decreases smoothly at the start and end, eliminating torque discontinuities. In the embodiment shown in FIG. 14, the torque pulling away from the user decreases (becomes less negative) with distance, resulting in a more balanced effort. That is, the user does not have to resist the wheel as much as they are more fully extended because they have less leverage in this position (e.g., the extended position shown in FIG. 6). The effect of reducing torque in this manner is to provide a more balanced effort by the user throughout the exercise.

[0079] FIG. 15 includes three graphs illustrating exemplary braking torque curves. In particular, the bottom graph in FIG. 15 plots the distance traveled (in revolutions) of the fitness wheel 100 versus time for one repetition (or "cycle") of the exercise. More importantly for this exercise, the middle graph in FIG. 15 plots the speed (revolutions per second) of the fitness wheel 100 versus time for one repetition (or "cycle") of the exercise. The top graph in FIG. 15 illustrates the percentage of motor torque applied corresponding to the speed versus time curve. Positive torque values in this plot represent torque that opposes the positive forward motion of the wheel. In the embodiment shown in FIG. 15, the exercise is aerobic because the wheel feels like it is moving through sand to the user. The faster the user tries to move, the more the wheel resists movement. Although the user technically receives "assistance" when moving forward and "resistance" when moving backward, braking exercises are aerobic and difficult because the speed dependency forces the user to actively drive the wheel in both directions. Figure 15 shows an example with torque discontinuities at start and finish. While it is still desirable to increase or decrease torque in these cases, this braking profile is an example where the discontinuities are not particularly noticeable or bothersome to the user. This is because this particular exercise is very stable; the wheel only reacts to the user-controlled speed input, so the user never feels like they are "running away." At start, the user feels the wheel suddenly begin to resist their movement.

[0080] In some embodiments, the microcontroller 210 can be configured to apply ramp events that increase torque at one or more positions or velocities during exercise. One way to increase muscle activity and intensity is to increase stress near the rest position of the exercise, i.e., a region of the exercise that is normally ignored. Thus, at the beginning of the exercise, the user should experience a non-zero torque. Directly commanding a jump in motor torque would impose a jerky movement on the user's wrist, creating discomfort and endangering safety. Instead, it would be much more effective to allow the torque to increase to the desired level, but this is not trivial. In practice, there is a balance between the distance to reach the desired torque and the magnitude of the increase. In one embodiment, a dead band is programmed into the wheel so that no torque is applied for some distance (e.g., 0.2 revolutions), followed by an increase distance (e.g., 0.4 revolutions), over which the torque increases as a linear function of distance in the increase region (see FIG. 14 for an example). The torque is zero at the beginning of the increase region (0.2 revolutions in the example) and matches the profile torque at the end of the increase distance (0.6 = 0.2 revolutions + 0.4 revolutions in the example).

[0081] Additionally, a smooth transition at speed may require an increase in torque. The example boost event in Figure 13 illustrates a linear 20% torque increase as the wheel speed slows below a threshold, reaching full torque near zero speed. Figure 13 marks several points in the increase and decrease: the speed threshold where boost begins, the zero speed point, and the point where the torque curve returns to normal.

[0082] In some embodiments, the microcontroller 210 can be configured to apply a flutter event to provide feedback at one or more points during exercise. Flutter is an event implemented by rapidly switching the motor between two offset values from the nominal torque at any point along the torque profile. This event causes vibrations throughout the wheel and, in one embodiment, is configured as follows: τ wheel =τ nominal +τ flutter , where: τ flutter =A flutter sin(2πf flutter t) Equation 5.1.1-2 is.

[0083] In Equation 5.1.1-2, τ flutter is the output torque as a function of torque-generating current and time, τ nominal is the instantaneous commanded torque, f flutter is the flutter frequency in hertz, A flutter is the amplitude of the flutter, τ wheel is the total torque commanded to the wheel, and t is time. If the flutter event is patterned, a specific message can be conveyed to the user. For example, if the user rolls out and reaches 100% extension, the user may feel a cell phone-like vibration that indicates it is advisable to return to the rest position and complete the exercise repetition.

[0084] Certain exercises may require the user to pause at a particular point along the rollout or rollback (e.g., holding a plank, doing push-ups, etc.). Therefore, in one embodiment, the microcontroller 210 can be configured to apply hold events at one or more locations during the exercise. Hold events are an important way to stop the user in a deliberate yet smooth manner. Such an effect is designed to mimic a wheel in a divot in the ground (e.g., a depression that resists forward or backward movement). A hold is a function of two variables: position and time. In the case of a spatial profile, whether position-based or velocity-based, a hold event is applied to a position (x) on the exercise path. * hold ) as landmarks around which torque is selectively adjusted to create a "divot." In the case of a temporal profile, the hold effect is induced at a specified time within the exercise period. Whether the exercise is based on a spatial or temporal profile, once the hold effect is in effect, it can last for a period of time to smoothly return torque output to nominal. Alternatively, once the user has pushed through the divot, the hold can be turned off and nominal operation can resume. An example formula is as follows:

number

[0085] 2.4.2.5 Exercise The components of the above sections (2.4.2.1-4) are combined and supplemented with exercise posture instruction information (given as a digital product, e.g., in the form of a smartphone app) to obtain the final product: the exercise.

[0086] 2.4.3 Communication In one embodiment, fitness wheel 100 is enabled by Bluetooth connectivity and can be integrated with a software app for a smartphone or watch. The wheel can be configured to function independently of the smartphone app using the input selection rotary dial. However, the smartphone app can enhance the user experience by adding personalized optimization, advanced exercises, and in-app training.

[0087] In one embodiment of fitness wheel 100, a separate Bluetooth and supervisor control microcontroller (e.g., 212) is configured to operate the wheel, with the detailed exercise (i.e., instantaneous motor torque) controlled by a second microcontroller (e.g., 214). However, it should be understood that a single microcontroller could potentially be configured to operate both functions.

[0088] 2.4.4 Safety mechanisms Because the fitness wheel 100 incorporates the use of electric motors, there are some inherent risks, and therefore the fitness wheel is preferably configured to implement safety measures and protocols.

[0089] The main risk of using a motorized fitness wheel is the motor delivering unexpected torque or spinning. This can occur mid-exercise if the user lets go of the wheel, the wheel lifts off the floor, or the wheel skids across the surface. All three of these abnormal events share a single condition: a sudden increase or decrease in wheel speed. Thus, in one embodiment, a specific speed threshold can be defined, and the microcontroller 210 can be configured to stop the wheel if the speed threshold is passed. Alternatively, acceleration can be used as an emergency stop criterion. Alternatively, the microcontroller can stop the wheel if the motor is spinning too fast for this particular exercise.

[0090] In resistance mode, the wheel is pushed away from the user, so special attention must be paid to safety. In one embodiment, if the wheel moves too far (indicating an abnormal event such as the user lifting the wheel, losing grip on the wheel, or excessive wheel slippage), the wheel will brake to a stop. The inertia of the handle 7 and stator assembly is intentionally designed to be less than the inertia of the rotor and wheel assembly, so that if the user lets go of the wheel, the handle may rotate but the wheel may remain in place. This is an important safety feature.

[0091] Another risk of performing wheel-based exercises using a motorized fitness wheel is excessive speed during exercise. For a user, improperly performing an exercise at too great a speed through its range of motion can lead to muscle strain. Therefore, in one embodiment, to prevent excessive speeding, a manual speed limit can be programmed into the software, and the microcontroller is configured to apply a braking effect to the wheel torque if the speed limit is exceeded. Additionally, in one embodiment, if a sensor on the wheel detects that excessive force is still present (indicating tampering), the microcontroller can shut down the motor to prevent overcurrent.

[0092] 2.4.5 Reducing wrist torque The simulation in Section 2.4.2.1 illustrates that the wrists will experience the full torque of the wheel. While this is good for building wrist strength, there are instances where certain users may want or need to reduce wrist stress. In one instance, wrist torque reduction is achieved by modifying the wheel's programming to either reduce the torque or slow the application of torque. In another instance, a wrist torque reduction structure can be optionally added to the fitness wheel 100 to transfer torque from the handles to the forearms in the form of force and shear. By way of illustration, FIG. 16 is a side view of a fitness wheel 100 including an exemplary implementation of a wrist torque reduction structure 1600. While only one structure 1600 is shown in FIG. 16, it should be understood that a second wrist torque reduction structure 1600 could be attached to the other handle (not shown) as well. Structure 1600 comprises two members extending from the handle 7. One member 1605 is joined to the handle near the handle's inner end adjacent the hub, and a second member 1610 is joined to the handle near the handle's free end. Extending between the members is a wrist guard. The wrist guard has a central opening through which a user can insert their hand to grasp the handle. Members 1605, 1610 are joined to the handle in a fixed relationship (i.e., so as not to rotate relative to the handle).

[0093] In another embodiment, the wrist torque structure can comprise wheels and / or glides attached to the handle and configured to interact with the floor to reduce or eliminate torque in response to compliance. Illustratively, FIG. 17 is a side view of a fitness wheel further comprising an exemplary implementation of a wrist torque reduction structure 1700, comprising two ground-contacting components 1710 attached to the handle 7 using mounts 1720 configured to maintain the components 1710 in a fixed relationship relative to the handle 7. Although not shown, a similar wrist reduction structure can be attached to the opposite handle.

[0094] In another embodiment, the wheels may comprise two, three, or four ground-contact wheels spaced apart in at least the anterior / posterior direction to provide stability and eliminate wrist torque.

[0095] 2.4.6 Learning or User Adaptation The microcontroller constantly monitors the ongoing exercise. It can use the collected data to adapt the exercise to a particular user. For example, a wheel can automatically adapt to the user's height by recording the start position of the exercise and the fully extended position. For example, a default setting for a wheel can specify that the user has a given height, e.g., six feet (6'), and as such, the torque trajectory can be implemented according to the average rollout distance for a 6' individual. However, during use, the microcontroller can determine from sensor readings whether the user's actual rollout distance matches the default setting distance. Illustratively, the microcontroller may determine that the actual rollout distance corresponds to a much shorter person, e.g., a five-foot tall individual. As can be appreciated, if the torque trajectory defines torque as a function of distance, the portion of the torque curve near the fully extended position may not be reached unless the torque curve is modified. Thus, the microcontroller can be configured to adaptively adjust the torque curve to more optimally fit the actual distance between the start position and the fully extended position, for example, by rescaling the torque trajectory as a function of the actual distance.

[0096] By recording your speed during exercise, the wheel can change settings to give you better control over your speed. The wheel can use this information in conjunction with a smartphone application to prompt you to extend further or vary the pace of your exercise, among other things, to improve your workout.

[0097] In some cases, one key to a good exercise may be slow repetitions, and a user performing repetitions too quickly may not be reaping the full benefits of the exercise and risk injury. Thus, the microcontroller can be configured to monitor speed, and if the microcontroller determines that an individual is pacing too fast over the course of a cycle (or one or more portions thereof), the microcontroller can be configured to adaptively modulate the output torque to force the user to slow down. This can be achieved by the microcontroller reducing the amount of assistance being provided by the wheel torque (e.g., providing less assistance) or by applying a torque that opposes the user's movement (e.g., providing more resistance). By way of illustration, if the microcontroller is applying an assistance torque trajectory and determines that the user is moving too fast during rollout, the microcontroller can increase the torque that opposes the direction of rotation to force the user to slow down during rollout. Similarly, if it is determined that the user is moving too quickly during rollback, the microcontroller can reduce the amount of assistance (e.g., wheel torque pushing the wheels back toward the starting position) or even provide resistance as needed to encourage the user to slow down appropriately.

[0098] The microcontroller can be configured to adaptively adjust the wheel torque using various methods. Illustratively, the microcontroller can scale the amount of torque by a scaling factor applied to one or more portions of the torque trajectory. Additionally or alternatively, the microcontroller can be configured to change the torque trajectory to another torque trajectory that is more suitable for addressing the condition. In certain embodiments, the microcontroller can be configured to adaptively adjust the torque over the entire cycle, over one or more segments of the cycle, e.g., during rollout, rollback, and / or smaller portions thereof, or over a combination of the foregoing. More generally, the microcontroller can be configured to adaptively adjust the torque trajectory based on one or more various parameters related to the user's posture, including speed, distance, acceleration, torque, and time, among others. Simultaneously, the microcontroller can provide feedback to the user regarding the detected condition or torque adjustment, illustratively by illuminating one or more LEDs or outputting a notification (e.g., the message "Slow down - you're going too fast") via the application interface to notify the user.

[0099] 3 Example configurations and practical scenarios These and other features of fitness wheel 100 will be further understood from the following discussion of exemplary embodiments of the fitness wheel and how the fitness wheel is configured to operate when used in various exemplary scenarios.

[0100] In an exemplary scenario, a user owns a motorized fitness 100 wheel without an associated digital interface 250. As previously described, the fitness wheel 100 can be configured for use without the digital interface 250. In such a situation, the wheel's onboard microcontroller 210 software is configured to default to a pre-programmed set of trajectories / events that can be different for assisted, resisted, and neutral modes. In one embodiment, in assisted mode, the applied trajectory can be a nonlinear spring model trajectory that includes a boost event at the end of the rollout. In resisted mode, for example, the trajectory is configured with a nonlinear spring and constant model and no events are present. In neutral mode, the trajectory is zero torque and no events are present (i.e., no assistance or resistance is provided by the motor). The built-in trajectories / events can be general enough to allow a user to perform a variety of exercises using different sequences of movements (postures) without the need for an app.

[0101] In one embodiment, the user powers on the motorized fitness wheel by pressing the power button 6. The motorized fitness wheel 100 provides power-on feedback via animation on the wheel rim LED 2. After the animation, the LED-backlit numbers on the exercise difficulty display 3 flash in unison, and the wheel rim LED 2 illuminates solid white, prompting the user to select an exercise difficulty level. The number to the left of zero flashes green (indicating assistance), the number to the right of zero flashes red (indicating resistance), and the zero flashes white (indicating neutral). When the user turns the difficulty selection rotary dial 4, the flashing animation stops and the LED behind the selected number lights up alone in the appropriate color. The wheel rim LED 2 emphasizes the selection by matching colors.

[0102] The user rotates the difficulty level selection rotary dial 4 clockwise, e.g., to the number "2"; after a few seconds, the wheel rim LED 2 fades to yellow, indicating that the fitness wheel 100 is ready for use. The user places the motorized fitness wheel in the start / rest position for the exercise and begins a rollout (i.e., the user pushes against the wheel, stretching the body as the wheel rolls forward along the surface). When the wheel's onboard microcontroller 210 determines from sensor data that the wheel has begun to roll, the wheel rim LED (which glows green in the exemplary selected mode) turns off, and the microcontroller 210 initiates the motor 9 to initiate a specified torque trajectory (e.g., the trajectory of FIG. 13).

[0103] Because the user has selected the assistance mode, the motor controller 214 can be configured to default to a prescribed trajectory. By way of illustration, in one embodiment, the trajectory can be based on a quadratic spring profile such that the torque response is proportional to the square of the non-dimensionalized distance from the start / rest position. As a result, as the user pushes off from the start / rest position, the motor pushes in the opposite direction to the direction of displacement. This response ensures that the user is gently nudged to the extended position and then assists the user back to the beginning of the exercise. As wheel torque increases, the microcontroller 210 causes LED2 to glow more brightly. Additionally, when the user reaches a threshold (e.g., exceeding a prescribed displacement from the start / rest position and falling below a prescribed speed), the rim LED reaches full brightness (green) and the microcontroller 210 initiates a boost event. This has the effect of a kickback force, assisting the user in rolling back during the most difficult part of the exercise (extended position). As described in Section 2.4.2.4, boost is generated by rapidly but smoothly increasing torque above the nominal excursion.

[0104] In another embodiment of the fitness wheel 100, the user owns a motorized fitness wheel and an associated digital interface 250. When the motorized fitness wheel is used with the digital interface 250 enabled on the user's mobile device, the digital interface 250 functions as an additional interface with additional features. Most notably, the application running on the digital interface can include a library of exercises and workouts (exercises grouped together) along with instructional videos that increase the effectiveness of the user's exercise experience. During exercise, the digital interface 250 can be configured to provide a live information interface for the user to view repetitions and exercise duration based on information provided in real time by the fitness wheel 100's microcontroller 210. If the user has connected fitness equipment, information such as heart rate and estimated calories burned can also be displayed in the application interface. The application's dashboard can display any data related to fitness or health progress selected by the user. The user also has the option to view recent and favorite exercises directly on the dashboard, allowing for easy revisiting of exercises upon opening the application.

[0105] In this exemplary configuration, the system begins by turning on both the motorized fitness wheel 100 and the digital interface 250. The user preferably has previously connected to the wheel, and as long as the Bluetooth setting on the smart device is turned on, the device should automatically connect to the motorized fitness wheel. The motorized fitness wheel notifies the user that the device is connected by sweeping LED2 on the wheel rim with a blue light. After the sweep animation, the LED flashes white, prompting the user to select an exercise on the device.

[0106] On the digital interface 250, the user can navigate to a library of exercises and select, for example, an exercise to train core endurance. The exercise trajectory can be, for example, a simple damping profile, meaning that the torque response is proportional to and inverse to the user's speed in the rollout. Once an exercise is selected, associated information including the trajectory, events, and the like can be transmitted to the fitness wheel 100 for storage in a processor-accessible storage medium and executed by the processor (e.g., microcontroller 210).

[0107] After selecting an exercise, the wheel rim LED 2 changes to solid white and the LED-backlit numbers on the exercise difficulty display 3 flash, prompting the user to select a difficulty level. The user can configure the exercise difficulty by using the selection rotary dial 4 on the wheel or by using the application, the latter configured to allow the user to select non-integer values (e.g., 2.5, 4.2, etc.). The user confirms that the application remembers and highlights the most recently used difficulty level: 4 in resistance mode.

[0108] The user selects within the application to continue at the last used difficulty level, and the wheel rim LED fades to yellow, indicating the wheel is ready for use. The user places the motorized fitness wheel in the start / rest position for the exercise and begins a rollout. When the wheel's onboard microcontroller 210 determines from data received from sensor 215 that the user has initiated a rollout, wheel rim LED2 (which is illuminated yellow) turns off, and the microcontroller 210 causes the motor to begin a specified torque trajectory, such as the braking mode torque shown in FIG. 15.

[0109] As the user pushes outward from the exercise's start / rest point, the fitness wheel 100 responds to speed according to a torque trajectory. Illustratively, the faster the wheel is pushed, the greater the amount of torque commanded in the opposite direction. The resulting effect is as if the ground were muddy or sandy. As the user performs each repetition, the wheel rim LED 2 lights green once the user passes a specified threshold distance representing the maximum range of motion. In one embodiment, this threshold distance can be estimated based on the user's height information provided in the application. If the user decides not to share their information, the microcontroller 210 can be configured to define the threshold distance by default based on average height or a previously defined threshold distance.

[0110] The digital interface 250 allows the user to define the number of repetitions they wish to perform before performing an exercise. If this information is provided, the microcontroller 210 can be configured to perform a flutter event on the penultimate repetition, thereby providing haptic feedback to the user that the exercise is about to end.

[0111] The digital interface 250 is intended to provide a class of exercises that guides the user with ongoing instruction through an exercise routine. The application can be configured to automatically provide input to the microcontroller 210 that serves to change wheel settings such as assistance / resistance level, trajectory, events, and to instruct the wheel to provide timing to the user. For example, one part of the routine might be to instruct the user to hold position (as in the "plank" exercise) and wait until LED2 and / or wheel flutter indicates to continue the exercise. The wheel timing can be synchronized with the software application's instructions, creating a continuous and engaging exercise routine.

[0112] FIG. 18 is a hybrid system and process flow diagram of an exemplary embodiment of a method 1800 for operating an electric motor 9 (shown as electric motor 1801) that may be implemented by an electric motor controller 214 according to the present disclosure. After power-up, the electric motor controller 214 first orients itself by monitoring the transitions of certain Hall-effect sensors. After orienting, the controller enters a current proportional-integral (PI) control loop 1810. The electric motor controller measures and calculates position (1831, 1832, 1833), speed (1835), and measured current of the electric motor (1820). The position (e.g., angle of rotation) and speed (collectively 1834) are used in conjunction with an exercise profile 1850 to determine DQ reference current commands (1836, 1837). The current and position (1820, 1832, respectively) are provided as feedback to the PI current control loop. Specifically, a Clarke transform (1811) performed on the measured currents (1820) followed by a Park transform (1812) performed on the output (1821) converts the real {Ia, Ib, Ic} currents in the stationary reference frame to DQ currents (1822, 1823) in the synchronous reference frame. The DQ currents are provided as inputs to PI controllers 1813, 1814. The PI controllers compare the real DQ currents (1822, 1823) with reference DQ currents (1836, 1837) (e.g., desired torque) and calculate the DQ current error (i.e., the current to approximate our reference current), which is dictated via the PI algorithm. The controllers then output DQ voltage commands (1824, 1825) based on the current errors (and their time integrals). The Q voltages (1825) are corrected for back EMF by a voltage decoupler 1815. The inverse Park transform 1816 and space vector modulator 1817 convert the DQ voltage into a PWM duty cycle (1828) for output to a three-phase inverter 1840. The three-phase inverter 1840 outputs a PWM voltage signal (1830) to the motor 1801.

[0113] The above configurations and features are non-limiting examples and do not encompass all embodiments that conform to the disclosed embodiments. It should be understood that various combinations, alternatives, and modifications of the present disclosure may be devised by those skilled in the art. The present disclosure is intended to encompass all such alternatives, modifications, and variations that fall within the scope of the appended claims.

[0114] The methods described herein may be implemented, in part or in whole, by software or firmware in machine-readable form on a tangible (e.g., non-transitory) storage medium. For example, the software or firmware may be in the form of a computer program containing computer program code adapted to perform some or all of the steps of any of the methods described herein when the program is executed on a computer or suitable hardware device (e.g., FPGA), in which case the computer program may be embodied on a computer-readable medium. Examples of tangible storage media include computer storage devices having computer-readable media such as disks, thumb drives, flash memory, and the like, but do not include propagated signals. While a propagated signal may reside in a tangible storage medium, the propagated signal itself is not an example of a tangible storage medium. The software may be suitable for execution on a parallel or serial processor such that the method steps may be performed in any suitable order or simultaneously.

[0115] It is to be further understood that like or similar numerals in the figures represent like or similar elements throughout the several figures, and that not all components or steps described and illustrated with reference to the figures are required for all embodiments or arrangements.

[0116] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly dictates otherwise. It will be further understood that the terms "comprises" and / or "comprising," as used herein, specify the presence of stated features, components, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, components, steps, operations, elements, components, and / or groups thereof.

[0117] Orientational terms are used herein merely for purposes of convention and reference and are not to be construed as limiting. However, it is recognized that these terms may be used relative to the observer. Therefore, no limitation is suggested or inferred. Additionally, the use of ordinal numbers (e.g., first, second, third) is for purposes of distinction and not for purposes of counting. For example, the use of "third" does not imply a corresponding "first" or "second." Additionally, the phraseology and terminology used herein are for descriptive purposes and should not be considered limiting. The use of "including," "comprising," "having," "containing," "involving," and variations thereof herein is intended to encompass the items listed thereafter and equivalents thereof, as well as additional items.

[0118] As used in this disclosure, the terms "a," "an," and "the" mean "one or more" unless expressly specified otherwise.

[0119] As used in this disclosure, the term "communications device" means any hardware, firmware, or software capable of sending or receiving data packets, command signals, or data signals over a communications link. A communications device may include a computer or a server. A communications device may be portable or stationary.

[0120] As used in this disclosure, the term "communications link" or "communications connection" refers to a wired or wireless medium that conveys data or information between at least two points. A wired or wireless medium may include, for example, a metallic conductor link, a radio frequency (RF) communications link, an infrared (IR) communications link, or an optical communications link. An RF communications link may include, for example, Wi-Fi, WiMAX, IEEE 802.11, DECT, 0G, 1G, 2G, 3G, 4G, or 5G cellular standards, BLE, LoRaWan, or Bluetooth.

[0121] The terms "computing machine" or "computing device" as used in this disclosure mean any machine, apparatus, circuit, component, or module, or any system of machines, apparatus, circuits, components, or modules, that is capable of manipulating data in accordance with one or more instructions, such as, without limitation, a processor, microprocessor, microcontroller, graphics processing unit, central processing unit, general purpose computer, supercomputer, personal computer, laptop computer, palmtop computer, notebook computer, desktop computer, workstation computer, server, server farm, computer cloud, or an array of multiple processors, microprocessors, microcontrollers, central processing units, general purpose computers, supercomputers, personal computer, laptop computer, palmtop computer, notebook computer, desktop computer, workstation computer, or server.

[0122] As used in this disclosure, the term "computer-readable medium" refers to any storage medium that participates in providing data (e.g., instructions) that can be read by a computer. Such media can take many forms, including non-volatile and volatile media. Non-volatile media include, for example, optical or magnetic disks and other persistent memory. Volatile media can be dynamic random access memory (DRAM). Common forms of computer-readable media include, for example, floppy disks, flexible disks, hard disks, magnetic tape, any other magnetic media, CD-ROMs, DVDs, any other optical media, punch cards, paper tape, any other physical media with patterns of holes, RAM, PROMs, EPROMs, FLASH-EEPROMs, any other memory chip or cartridge, carrier waves, or any other medium from which a computer can read. A computer-readable medium can also be a "cloud" containing files distributed across multiple (e.g., thousands) of memory caches on multiple (e.g., thousands) of computers.

[0123] Various forms of computer-readable media may be involved in transmitting the instruction sequences to the computer. For example, the instruction sequences may (i) be delivered to the processor from a RAM, (ii) be conveyed over a wireless transmission medium, or (iii) be formatted according to any of a number of formats, standards, or protocols, including, for example, Wi-Fi, WiMAX, IEEE 802.11, DECT, 0G, 1G, 2G, 3G, 4G, or 5G cellular standards, BLE, LoRaWan, or Bluetooth.

[0124] As used in this disclosure, the term "database" refers to any combination of software or hardware, including at least one application or at least one computing device. A database may include a structured collection of records or data organized according to a database model, such as, but not limited to, a relational model, a hierarchical model, or a network model. A database may include a database management system application (DBMS) as known in the art. The at least one application may include, but is not limited to, an application program capable of accepting connections from clients for service requests by sending responses back to the clients. A database may be configured to run the at least one application unattended and with minimal human direction for extended periods of time, often under heavy workloads.

[0125] As used in this disclosure, "comprising" and variations thereof mean "including, but not limited to," unless expressly specified otherwise.

[0126] The term "network" as used in this disclosure means, for example, but not limited to, at least one of a local area network (LAN), a wide area network (WAN), a metropolitan area network (MAN), a personal area network (PAN), a campus area network, an enterprise area network, a global area network (GAN), a broadband area network (BAN), a cellular network, or the Internet, any of which may be configured to communicate data via wireless or wired communications media. These networks may run a variety of protocols, including, but not limited to, TCP / IP, IRC, and HTTP.

[0127] As used in this disclosure, the term "server" refers to any combination of software or hardware, including at least one application or at least one computer, that performs services for connected clients as part of a client-server architecture. The at least one server application may be, for example, but not limited to, an application program that can accept connections from clients for service requests by sending responses back to the clients. A server may be configured to run at least one application for extended periods of time, often under heavy workloads, unattended, and with minimal human direction. A server may include multiple configured computers, with at least one application divided among the computers depending on the workload. For example, under light loads, at least one application may run on a single computer. However, under heavy loads, multiple computers may be required to run at least one application. A server, or any of its computers, may also be used as a workstation.

[0128] The term "transmission," as used in this disclosure, refers to the transfer of signals via electricity, sound waves, light waves, and other electromagnetic radiation, such as those generated using communications in the radio frequency (RF) or infrared (IR) spectrum. Transmission media for such transmissions can include coaxial cables, copper wiring, and fiber optics, including the wiring that comprises a system bus coupled to a processor.

[0129] Devices that are in communication with each other need not be in continuous communication with each other unless explicitly specified otherwise. In addition, devices that are in communication with each other may communicate directly or indirectly through one or more intermediaries.

[0130] Although process steps, method steps, or algorithms may be described in sequential or parallel order, such processes, methods, and algorithms may be configured to work in alternative orders. In other words, any permutation or order of steps that may be described in sequential order does not necessarily indicate a requirement that the steps be performed in that order, and some steps may be performed simultaneously. Similarly, if a permutation or order of steps is described in parallel (or simultaneous) order, such steps may be performed in sequential order. The steps of processes, methods, or algorithms described herein may be performed in any order practical.

[0131] Where a single device or article is described, it will be readily apparent that multiple devices or articles may be substituted for the single device or article. Similarly, where more than one device or article is described, it will be readily apparent that a single device or article may be substituted for the more than one device or article. The functionality or features of a device may alternatively be embodied by one or more other devices not expressly described as having such functionality or features.

[0132] The above subject matter is provided by way of example only and is not to be construed as limiting. Various modifications and variations can be made to the subject matter described herein without following the exemplary embodiments and applications shown and described, and without departing from the true spirit and scope of the invention, as encompassed by this disclosure and by equivalent structures, functions, or steps to those descriptions.

Claims

1. The user performs an exercise having at least one cycle, which is formed by rolling the wheel forward along the surface from a nearly stationary position to an extended position, and then rolling the wheel backward along the surface from the extended position towards the stationary position: A wheel assembly including a surface contact component configured to contact the aforementioned surface and to rotate either forward or backward around the axle, thereby rolling along the surface either forward or backward; First and second handles, configured to receive the respective hands of the user, and extending outward from the sides of the wheel assembly; A motor coupled to the wheel assembly and configured to apply output torque to the surface contact component in either the forward rotational direction or the backward rotational direction; A microcontroller comprising one or more processors and configured to control the output torque of the electric motor; A first sensor that communicates with the microcontroller and is configured to determine the movement variables of the exercise wheel in real time over at least one cycle, the first sensor measures the rotation angle of the electric motor, and the movement variables include one or more of the position of the exercise wheel, the speed of the exercise wheel, and the acceleration of the exercise wheel; A non-transient, computer-readable storage medium accessible by the microcontroller, wherein the microcontroller is further configured to dynamically control the output torque of the electric motor over the exercise cycle as a function of the rotation angle, the determined movement variable, and one or more torque trajectory parameters, the one or more torque trajectory parameters including a torque profile, the torque profile defining a target output torque value of the electric motor, which varies as a function of one or more of the position, the velocity, and the acceleration; A battery mounted on the exercise wheel, configured to supply power to the electric motor and the microcontroller, Includes an electric motorized exercise wheel.

2. The torque profile is: A spatial torque profile that defines the target output torque value as a function of spatial variables, wherein the spatial variables include one or more of position and velocity information, and A time torque profile in which the target output torque value is defined as a function of time, wherein the time variable is time. An exercise wheel with an electric motor according to claim 1, wherein one or more of the following are present.

3. The motorized exercise wheel according to claim 1, wherein the one or more torque trajectory parameters comprise a combination of torque profiles, the resulting combination of torque profiles define the target output torque value as a function of one or more spatial and temporal variables, the spatial variable comprising position information or velocity information, and the temporal variable being time.

4. The motorized exercise wheel according to claim 3, wherein the plurality of torque profiles are combined with one or more of the following: piecewise coupling and linear coupling based on a weighting function.

5. The motorized exercise wheel according to claim 1, wherein the microcontroller is configured to monitor the movement variable to detect the occurrence of a specified condition, and in response to the detection of such occurrence, to control the output torque of the motor over a portion of the exercise cycle based on the torque profile in combination with an auxiliary torque event, the auxiliary torque event defining the target output torque for the portion of the exercise cycle as a function of one or more of the position, the velocity, and the acceleration.

6. An exercise wheel with an electric motor according to claim 1, further comprising a second sensor operably communicating with the microcontroller, wherein the second sensor is configured to measure information representing the output torque of the electric motor, the second sensor is arranged to feed back the measured information to the microcontroller, and the microcontroller is further configured to control the output torque of the electric motor as a function of the rotation angle, the target output torque value, and the measured information representing the output torque of the electric motor.

7. A user interface that is operationally communicating with the microcontroller and configured to receive user input indicating one or more of several exercise parameters, Multiple torque trajectory parameters stored in the aforementioned storage medium, An exercise wheel with an electric motor according to claim 1, further comprising: The motorized exercise wheel according to claim 1, wherein the microcontroller is configured to select a torque trajectory parameter from a plurality of torque trajectory parameters based on one or more exercise parameters, and to control the output torque of the motor according to the selected torque trajectory parameter.

8. The motorized exercise wheel according to claim 1, wherein the microcontroller is configured to control a first torque trajectory parameter during forward movement of the wheel and a second torque trajectory parameter during reverse movement of the wheel, the first torque trajectory parameter and the second torque trajectory parameter being different.

9. The motorized exercise wheel according to claim 5, wherein the determined movement variables include the position and the speed, the microcontroller monitors the speed to detect specified conditions, the torque profile defines a target output torque as a function of the position during the exercise, and auxiliary torque events define a target output torque for a portion of the exercise cycle as a function of the speed.

10. A method for operating an exercise wheel with an electric motor, wherein the user performs an exercise having at least one cycle formed by rolling the wheel forward along a surface from a substantially stationary position to an extended position, and then rolling the wheel backward along the surface from the extended position to the stationary position, the wheel comprising: a wheel assembly including a surface contact component; an electric motor coupled to the wheel assembly; first and second handles extending from the wheel assembly and operated by the user; a microcontroller; and a battery mounted on the exercise wheel, configured to supply power to the electric motor and the microcontroller, the method being performed by the microcontroller: The rotation angle of the electric motor and the movement variables relating to the movement of the exercise wheel during the exercise are determined using a first sensor, and the rotation angle and the movement variables are determined in real time using the first sensor throughout at least one cycle, wherein the movement variables include one or more of the position of the exercise wheel, the speed of the exercise wheel, and the acceleration of the exercise wheel. Determining a target output torque for the electric motor based on the determination of the moving variables and one or more torque trajectory parameters, wherein the one or more torque trajectory parameters include a torque profile that defines a target output torque value for the electric motor, which varies as a function of one or more of the position, the velocity, and the acceleration. Controlling the output torque of the electric motor over the exercise cycle as a function of the rotation angle and the determined target output torque, A method that includes this.

11. The method according to claim 10, wherein the one or more torque trajectory parameters comprise a plurality of torque profiles, the resulting torque profile defines the target output torque as a function of one or more of the spatial and temporal variables, the temporal variable being time.

12. The aforementioned moving variables are monitored to detect the occurrence of the specified conditions, In response to the detection of the occurrence, the output torque of the electric motor is controlled over a portion of the exercise cycle based on the torque profile combined with the auxiliary torque event. The method according to claim 10, further comprising: A method in which the auxiliary torque event defines the target output torque for a portion of the exercise cycle as a function of one or more of the position, velocity, and acceleration.

13. Receiving a torque measurement result from a second sensor, wherein the torque measurement result represents the output torque of the electric motor, Controlling the output torque of the electric motor as a function of the rotation angle, the target output torque value, and the received measurement result representing the output torque of the electric motor, A method for operating the motorized exercise wheel according to claim 10, further comprising:

14. The method according to claim 10, comprising controlling the output torque of the electric motor according to a first torque trajectory parameter including a first torque profile while the wheel moves forward, and controlling the output torque of the electric motor according to a second torque trajectory parameter including a second torque profile while the wheel moves backward, wherein the first torque profile and the second torque profile are different.

15. The motorized exercise wheel according to claim 12, wherein the determined movement variables include the position and the velocity, the microcontroller monitors the movement variables to detect the occurrence of a specified condition, the torque profile defines the target output torque during the exercise as a function of the velocity, and auxiliary torque events define the target output torque for a portion of the exercise size as a function of the position.

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