Patent Application
20210269111
Vehicle simulators replicate the experience of riding a human-supported vehicle (e.g., a bicycle or motorcycle) while keeping the vehicle stationary in the longitudinal, or fore/aft, direction. These trainers may be used for exercise, skills development, and physical therapy, and are particularly useful when riding outside is undesirable due to inclement weather. By keeping the vehicle longitudinally stationary, trainers may also be used to teach and develop safety skills before riding the vehicle in a non-stationary manner, such as on public roads and pathways. To aid with these uses, some trainers incorporate a virtual reality system that strives to provide to the rider a realistic experience that replicates the look and feel of riding in the real world.
One type of prior-art vehicle simulator is a bicycle trainer that clamps to a rear axle or frame of a bicycle, thereby providing the forces necessary to keep the bicycle upright without requiring the rider to balance the vehicle. A rear tire of the bicycle contacts a rear drum that is rotated by the rear wheel, when rotating via pedaling. The rear drum may also provide resistance to the rear wheel via magnetic, fluid, centrifugal, or other means, to simulate resistance encountered when riding outside. Typically, the front wheel of the bicycle does not rotate, remaining at rest. This type of indoor trainer may accommodate a wide variety of bicycle types and sizes, such as a bicycle sized according to the rider and to which the rider is accustomed to using.
Another type of prior-art vehicle simulator uses bicycle rollers. Unlike bicycle trainers, rollers do not affix to the bicycle frame or axle, and therefore the rider must actively balance the bicycle while pedaling. Typically, a set of rollers consists of two rear rollers that contact the rear wheel and are rotated by the rear wheel via pedaling, and one front roller that contacts the front wheel of the bicycle. A belt may connect the front roller with one of the rear rollers such that the front roller is rotated by the belt when pedaling. The spacing between the may be adjusted to match the bicycle's wheelbase, thereby accommodating a variety of bicycle types and sizes.
Embodiments described herein are vehicle simulators for human-supported vehicles that help a rider balance the vehicle by laterally displacing two pivot points supporting the vehicle. Advantageously, lateral displacement may be human-controlled, and in some embodiments does not involve a wheel rolling on a belt or roller. Examples presented hereinbelow use a bicycle as the vehicle. However, embodiments may be used with another type of human-supported vehicle without departing from the scope hereof; examples of other such human-supported vehicles include motorcycles, scooters, skateboards, snowboards, surfboards, roller skates, boats (e.g., sculls), and skis.
A bicycle is one example of an inverted pendulum, a classic problem in dynamics and control theory in which the system is unstable, that is, the system will fall over under the influence of gravity. One strategy to stabilize an inverted pendulum (i.e., keep the system upright) affixes a pivot point of the system to a cart that moves laterally to remove a torque, induced by gravity, that tends to rotate the system around the pivot point to topple the system. One example of this strategy is balancing a stick on its end with one's hand: when the stick starts to fall, one may move his or her hand laterally to “catch” the stick such that it stays upright.
One aspect of the present embodiments is the realization that a vehicle may be balanced in a manner analogous to that of the stick, that is, by laterally displacing a pivot point beneath the vehicle to “catch” it when it starts to fall over. A bicycle, for example, has two pivot points, one under each of the front and rear wheels. By steering (e.g., turning the handlebars and fork of the bicycle), the rider introduces a lateral component to the velocity of the front pivot point, causing the front wheel to translate laterally. The lateral motion of the front wheel changes a heading of the bicycle frame, which in turn causes the rear wheel to laterally translate to follow the lateral translation of the front wheel. This series of lateral motions balances the bicycle, preventing it from falling over.
Advantageously, embodiments herein allow the vehicle to be laterally translated such that the rider may balance the vehicle in the same manner as when riding the vehicle without the simulator (e.g., on a road). Embodiments therefore provide a more realistic experience than prior-art simulators that do not allow the vehicle to be laterally translated and therefore do not require the rider to balance the vehicle (e.g., bicycle trainers). Furthermore, certain embodiments allow simulation of wind resistance, inclination, and road surface conditions.
Other prior-art exercise bicycles and motorcycle simulators may allow the rider to lean the vehicle, but include springs and/or actuators to hold and return the vehicle upright. One such simulator was developed in the 1960s by Stassen and Van Lunteren at the Delft University of Technology in the Netherlands. In this system, the pivot points of the vehicle were fixed in location, and hydraulic actuators were used to tilt the bicycle frame left and right. Such motion does not match the actual feel of riding and balancing a bicycle on a road or surface, which is subjected to zero torques about the ground contact line connecting the two pivot points (except in the case of training wheels). Cossalter discloses a tiltable motorcycle frame that is controlled similarly to methods of Stassen and van Lunteren.
U.S. Pat. No. 4,978,300 discloses a roll actuator assembly (see column 5). U.S. Pat. No. 5,547,382 discloses a rolling shaft driven by tilt motor. U.S. Pat. No. 6,733,294 fails to disclose balancing. U.S. Pat. No. 6,030,223 discloses a tilt shaft that is positioned higher up the vehicle (like sitting on a fence) and requires that the rider tip using arms. U.S. Pat. No. 6,234,800 discloses a four-bar linkage rather than pivot shaft; however, it is stable like a pendulum so there is no need for the rider to balance the vehicle.
Embodiments described herein improve on prior-art bicycle rollers, as described above, by supporting each wheel at a single point. Unlike bicycle trainers, bicycle rollers allow the front and rear wheels of the bicycle to laterally translate. However, the use of two rear rollers, needed to longitudinally constrain the motion of the bicycle, also creates double contacts on the rear wheel that do not accurately mimic the forces applied to a single ground contact point of the rear wheel, such as when riding the bicycle on a road. Furthermore, some riders position the front roller to support the front wheel in front of the ground contact point, resulting in a force on the front wheel that differs from the force that would be applied to the ground contact point when riding the bicycle on a road. For these reasons, embodiments described herein provide a more realistic feeling to riders of the vehicle as compared to rollers.
Similar lateral translations may be achieved by riding the bicycle on a moving belt, such as a treadmill. The belt accurately recreates the physics of balancing by contacting each wheel at a single ground contact point. However, the use of a fast-moving belt provides a serious risk of injury to both rider and observer.
In a first aspect, a vehicle simulator to assist balancing of a vehicle includes a front translation mechanism that supports a front portion of the vehicle and laterally translates the front portion to change a heading of a rear portion of the vehicle in response to steering of the vehicle. The vehicle simulator also includes a rear translation mechanism that supports the rear portion and laterally translates the rear portion in response to the change of heading, and a longitudinal restraint mechanism configured to physically couple with the vehicle to longitudinally constrain the vehicle.
In certain embodiments of the first aspect, the front portion of the vehicle includes a front wheel, and the rear portion of the vehicle includes a rear wheel. The front translation mechanism has a front surface longitudinally movable to rotate the front wheel, wherein the rotating front wheel laterally translates along the moving front surface in response to the steering. The rear translation mechanism has a rear surface longitudinally moveable by the rear wheel, when rotating, wherein the rotating rear wheel laterally translates along the moving rear surface in response to the change of heading.
In certain embodiments of the first aspect, the vehicle simulator further includes a linear guide that restrains movement of the longitudinal restraint mechanism to a lateral guide axis.
In certain embodiments of the first aspect, the vehicle simulator further includes a drive belt mechanically coupled to move the front surface at a longitudinal speed similar to a longitudinal speed of the rear surface.
In certain embodiments of the first aspect, the vehicle simulator further includes a motor physically coupled to longitudinally move the front surface, a rear speed sensor that outputs a rear longitudinal speed signal in response to the rear surface moving, a front speed sensor that outputs a front longitudinal speed signal in response to the front surface moving, and a controller that receives the front and rear longitudinal speed signals and controls the motor to move the front surface according to the front and rear longitudinal speed signals.
In certain embodiments of the first aspect, the controller is configured to control the motor to move the front surface such that the front longitudinal speed signal follows the rear longitudinal speed signal.
In certain embodiments of the first aspect, the vehicle simulator further includes a resistance generator that resists longitudinal motion of the rear surface.
In certain embodiments of the first aspect, the resistance generator includes an electric motor physically coupled with the rear surface and controllable, by the controller, in a motoring mode and a generator mode.
In certain embodiments of the first aspect, the vehicle simulator further includes a torque sensor that outputs a torque signal in response to a torque of the electric motor, wherein the controller is configured to control the electric motor such that the torque signal follows a torque setpoint.
In certain embodiments of the first aspect, the controller is further configured to algorithmically select the torque setpoint according to a model of a rolling resistance force between the rear wheel and a surface such that the torque simulates the rolling resistance force.
In certain embodiments of the first aspect, the controller is further configured to algorithmically select the torque setpoint according to a model of a drag force such that the torque simulates the drag force.
In certain embodiments of the first aspect, the vehicle is a bicycle and the longitudinal restraint mechanism includes an arm having a variable length, and a top joint coupled with a top end of the arm and configured to physically couple with the bicycle, the top joint having a top axis parallel to a lean axis of the bicycle. The longitudinal restraint mechanism also includes a bottom joint physically coupled with a bottom end of the arm and having a bottom axis parallel to the lean axis, and a turntable that supports the linear guide and the bottom joint, and is rotatable about a vertically-oriented turntable axis in response to the changing heading. When the bicycle leans, the arm pivots at the top axis and the bottom axis, and the length of the arm changes to allow the arm to remain parallel to a plane of the rear wheel.
In certain embodiments of the first aspect, the turntable axis is aligned with a ground contact point of the rear wheel.
In certain embodiments of the first aspect, the top joint is configured to physically couple with an axle of the rear wheel.
In certain embodiments of the first aspect, the top joint is configured to physically couple with a frame of the bicycle.
In certain embodiments of the first aspect, the front surface includes a front roller, and the vehicle simulator further includes an adjustable spacer that longitudinally positions the front roller to support a ground contact point of the front wheel.
In certain embodiments of the first aspect, the vehicle is a bicycle and the longitudinal restraint mechanism includes an arm, and a joint, coupling a first end of the arm with the linear guide, that allows the arm to (a) rotate around the guide axis, (b) pivot about a pivot axis perpendicular to the guide axis, and (c) twist about a longitudinal axis of the arm. The longitudinal restraint mechanism also includes a rolling-element bearing, coupling a second end of the arm with the bicycle, that allows the arm to rotate about a rotation axis of the rear wheel. When the bicycle leans: (a) the arm twists about the longitudinal axis, (b) the second end of the arm rotates about the rotation axis of the rear wheel, and (c) the first end of the arm rotates about the guide axis and pivots at the pivot axis, such that the arm remains parallel to a plane of the rear wheel.
In certain embodiments of the first aspect, the rolling-element bearing is configured to physically couple with an axle of the rear wheel.
In certain embodiments of the first aspect, the rolling-element bearing is configured to physically couple with a frame of the bicycle.
In certain embodiments of the first aspect, the front surface includes a front roller, and the vehicle simulator further includes an adjustable spacer that longitudinally positions the front roller to support a ground contact point of the front wheel.
In certain embodiments of the first aspect, the front translation mechanism includes a front carriage having a front joint configured to support the vehicle at the front portion, rotate about a front lean axis, and rotate about a front heading axis. The front translation mechanism also includes a steering sensor that senses a front heading angle of the front joint about the front heading axis, and a front actuator that laterally translates the front carriage. The rear translation mechanism includes a rear carriage having a rear joint configured to support the vehicle at the rear portion, rotate about a rear lean axis, and rotate about a rear heading axis. The rear translation mechanism also includes a rear actuator that laterally translates the rear translation mechanism. The vehicle simulator further includes a controller that algorithmically determines front and rear lateral velocities based on the front and rear heading angles, respectively, and a nominal forward speed. The controller, in response to the steering of the vehicle, controls the front and rear actuators to laterally translate the respective front and rear carriages according to the respective front and rear lateral velocities.
In certain embodiments of the first aspect, the vehicle simulator further includes a front lean sensor that measures a front lean angle of the front joint around the front lean axis. The controller is further configured to algorithmically determine a front lateral acceleration based on the front lean angle, and to control the front actuator to laterally accelerate the front carriage according to the front lateral acceleration.
In certain embodiments of the first aspect, the vehicle simulator further includes a rear lean sensor that measures a rear lean angle of the rear joint around the rear lean axis. The controller is further configured to algorithmically determine a rear lateral acceleration based on the rear lean angle, and to control the rear actuator to laterally accelerate the rear carriage according to the rear lateral acceleration.
In certain embodiments of the first aspect, the controller includes a switch that responds to an external signal to transition operation of the controller between an acceleration-based control mode and a velocity-based control mode.
In certain embodiments of the first aspect, the vehicle is a bicycle, the front joint is configured to support a front wheel of the bicycle, and the rear joint is configured to support a rear wheel of the bicycle.
In certain embodiments of the first aspect, the vehicle is a bicycle, the front joint is configured to support a front fork of the bicycle, and the rear joint is configured to support the rear portion of the bicycle via dropouts of the bicycle.
In certain embodiments of the first aspect, the vehicle includes a bicycle mounted to a stationary trainer that supports the bicycle and allows a rider to pedal the bicycle, wherein the front portion includes a front wheel of the bicycle. The front translation mechanism includes a front roller that rotates the front wheel of the bicycle such that the front wheel laterally translates along the front roller. The rear translation mechanism includes a rear platform having an upper surface that supports the trainer, a rotatable transfer wheel affixed to a lower surface of the rear platform to support the rear platform, and a turntable to allow the rear platform to rotate about a vertically-oriented turntable axis in response to the change of heading. The rear translation mechanism also includes a rotatable rear drum that supports and rotates the transfer wheel, the rear drum having a rotation axis parallel to a rotation axis of the front roller. The rear translation mechanism includes a linear guide coupled with the rear platform and configured to allow the rear platform to translate laterally without translating longitudinally and vertically. The transfer wheel, in response to the change of heading, laterally translates along the rotating rear drum to translate the rear platform laterally along the linear guide.
In certain embodiments of the first aspect, the rear platform further includes a rolling-element bearing that physically couples the transfer wheel with the lower surface of the rear platform, and allows the rear platform to lean about a lean axis parallel to a lean axis of the bicycle.
In certain embodiments of the first aspect, the turntable axis coincides with a ground contact point of a rear wheel of the bicycle.
In certain embodiments of the first aspect, the upper surface of the rear platform is configured to position a ground contact point of a rear wheel of the bicycle above the transfer wheel.
In certain embodiments of the first aspect, the vehicle simulator further includes an adjustable spacer that longitudinally positions the front roller such that the front roller contacts a ground contact point of the front wheel.
In certain embodiments of the first aspect, the vehicle simulator further includes a first motor that rotates the front roller, and a second motor that rotates the rear drum.
In certain embodiments of the first aspect, the vehicle simulator further includes a drive belt that mechanically couples the rear drum and the front roller, and a motor that rotates one of the front roller and the rear drum.
In certain embodiments of the first aspect, the vehicle simulator further includes at least one spring positioned to apply a restoring force that returns the rear platform to a horizontal orientation when a leaning force is removed.
In certain embodiments of the first aspect, the at least one spring includes vertically-oriented first and second springs, a top end of each of the first and second springs being affixed to the lower surface of the rear platform, a bottom end of each of the first and second springs being affixed to the turntable, and the first and second springs being laterally positioned equidistant from, and on opposite sides of, a bearing axis.
In a second aspect, a method to assist balancing of a human-supported vehicle includes longitudinally moving a front surface, supporting a front wheel of the vehicle at a ground contact point of the front wheel, to rotate the front wheel such that the rotating front wheel translates laterally along the moving front surface to change a heading of a rear wheel of the vehicle in response to steering of the vehicle. The method also includes supporting the rear wheel with a rear surface at a ground contact point of the rear wheel, wherein the rear surface is moved longitudinally by the rear wheel, when rotating, such that the rear wheel translates laterally along the moving rear surface in response to the change of heading. The method also includes longitudinally constraining the vehicle without lateral constraint.
In certain embodiments of the second aspect, the method further includes sensing a rear longitudinal speed of the rear surface, wherein said longitudinally moving the front surface includes moving the front surface at a front longitudinal speed based at least in part on the rear longitudinal speed.
In certain embodiments of the second aspect, the method further includes resisting the longitudinal motion of the rear surface to simulate resistance forces.
In certain embodiments of the second aspect, said resisting the longitudinal motion includes resisting the longitudinal motion to simulate a rolling resistance force according to a model of the rolling resistance force between the rear wheel and a surface.
In certain embodiments of the second aspect, said resisting the longitudinal motion includes resisting the longitudinal motion to simulate a drag force according to a model of the drag force.
In a third aspect, a method to assist balancing of a human-supported vehicle includes laterally translating a front portion of the vehicle to change a heading of a rear portion of the vehicle in response to steering of the vehicle, and laterally translating the rear portion of the vehicle in response to the change of heading such that the rear portion laterally follows the front portion.
In certain embodiments of the third aspect, the method further includes longitudinally constraining the vehicle.
In certain embodiments of the third aspect, said laterally translating the front portion of the vehicle includes sensing a front heading angle of the front portion of the vehicle, algorithmically determining a front lateral velocity based on the front heading angle and a nominal forward speed, and controlling a front actuator to laterally translate a front carriage at the front lateral velocity, the front carriage supporting the front portion of the vehicle. Said laterally translating the rear portion includes sensing a rear heading angle of the rear portion of the vehicle, algorithmically determining a rear lateral velocity based on the rear heading angle and the nominal forward speed, and controlling a rear actuator to laterally translate a rear carriage at the rear lateral velocity, the rear carriage supporting the rear portion of the vehicle.
In certain embodiments of the third aspect, said algorithmically determining the front lateral velocity includes algorithmically determining the front lateral velocity according to an equation vy=v·sin θf, where vy is the front lateral velocity, v is the nominal forward speed, and θf is the front heading angle. Said algorithmically determining the rear lateral velocity includes algorithmically determining the rear lateral velocity according to an equation vy=v·sin θr, where vy is the rear lateral velocity and θr is the rear heading angle.
In certain embodiments of the third aspect, the vehicle includes a bicycle, and the method further includes determining the nominal forward speed from a pedaling rate of a rider of the bicycle.
In certain embodiments of the third aspect, the front and rear portions of the vehicle include a front fork and a frame of a bicycle, respectively. The method further includes supporting the front fork and the frame.
In certain embodiments of the third aspect, the vehicle includes a bicycle having the rear portion affixed to a stationary trainer. Said laterally translating the front portion of the vehicle includes longitudinally moving a front surface, supporting a front wheel of the bicycle at a ground contact point of the front wheel, to rotate the front wheel such that the rotating front wheel translates laterally along the moving front surface to change a heading of the rear portion. Said laterally translating the rear portion of the vehicle includes longitudinally moving a rear surface supporting a transfer wheel affixed to a lower surface of a platform supporting the stationary trainer, the moving rear surface rotating the transfer wheel to laterally translate the transfer wheel along the moving rear surface in response to the change of heading.
In certain embodiments of the third aspect, the method further includes applying a restoring force to the platform to return the platform to a horizontal orientation when a leaning force is removed.
Balancing an Inverted Pendulum
The above technique to balance inverted pendulum 102 moves cart 104 laterally back-and-forth, according to the direction in which inverted pendulum 102 begins to topple. Thus, a lateral velocity of cart 104 changes in time, resulting in a lateral acceleration. Cart 104 must laterally accelerate to balance inverted pendulum 102.
Wheel 202 is unstable when not rolling and cart 204 is stationary. That is, wheel 202 will be rotated around contact point 206 by a gravitationally-induced torque so as to topple. Wheel 202 may be balanced by laterally moving cart 204 to position contact point 206 beneath a center-of-mass of wheel 202, thereby eliminating the gravitationally-induced torque by eliminating its moment arm. Thus, balancing of wheel 202 is like balancing of inverted pendulum 102 of
Three types of wheel rotation are referred to herein: (1) rotation of a wheel about its axle, (2) rotation of a wheel to change its heading angle, and (3) rotation of a wheel to change its lean angle. Unless otherwise indicated, rotation of a wheel refers the first type. For example, wheel 202 undergoes this first type of rotation when rolling along flat surface 210, as shown in
Bicycle 600 may be balanced by laterally moving (e.g., accelerating) front and rear wheels 602, 604 to position respective contact points 614, 616 beneath the corresponding wheels. Each wheel 602, 604 of bicycle 600 follows the dynamics of wheel 202, as discussed for
In the example of
Bicycle 600 is longitudinally stationary (i.e., vx=0) when used with the embodiments described herein. To balance bicycle 600 with some embodiments, front and rear heading angles θf, θr may be measured to determine the corresponding lateral velocities vy(f)=v×sin θf and vy(r)=v×sin θr, for a given speed v. Front and rear wheels 602, 604 may then be laterally moved according to the corresponding front and rear lateral velocities vy(f) and vy(r). Bicycle 600 can then be balanced by steering handlebars 622 to change the front heading angle θf, in turn (i) generating a front lateral acceleration that laterally moves front wheel 602, and (ii) changing the rear heading angle θr to generate a rear lateral acceleration that laterally moves rear wheel 604. When θf and θr are small (e.g., limited to a range of ±10°), vr(f) may be approximated by v×θf, and vy(f) may be approximated by v×θr.
Embodiments without Rotating Wheels
Vehicle simulator 800 also includes a rear translation mechanism 812(2) that supports a rear portion of bicycle 850 and laterally translates the rear portion in response to a heading of the rear portion of bicycle 850. Rear translation mechanism 812(2) includes a rail 802(2) aligned such that a rear carriage 804(2) is laterally movable along rail 802(2) in the y direction. In the example of
Each of adapters 806(1) and 806(2) includes a joint that allows bicycle 850 to lean. That is, bicycle 850 is not supported laterally and may topple sideways when not balanced or stabilized. Furthermore, front adapter 806(1) is rotatable about a vertical front support axis parallel to the z direction (e.g., front support axis 610 of
A controller 820 controls front and rear actuators 808(1) and 808(2) to laterally move carriages 804(1) and 804(2) along rails 802(1) and 802(2), respectively. Fork carriage 818 has a front heading sensor 810(1) that senses a front heading angle of fork 814. Rear carriage 804(2) has a rear heading sensor 810(2) that senses a rear heading angle of frame 854. Thus, heading sensors 810 effectively measure the heading angles of front and rear wheels of bicycle 850, as if the front and rear wheels were affixed to bicycle 850 in the conventional manner. That is, the heading angle of fork 814 corresponds to the front heading angle θf of front wheel 602 of
Controller 820 includes a processor, memory, and interface hardware that controls actuators 808 and receives sensed heading angles from sensors 810. An algorithm 822 (e.g., see algorithm 2832 in
As an example of algorithm 822, when handlebars 852 are turned clockwise (about the z-axis, as viewed from above) the heading angle sensed by front heading sensor 810(1) decreases, causing controller 820 to control actuator 808(1) to move front carriage 804(1) in the negative y direction (see coordinate system 120). As front carriage 804(1) moves, the heading angle sensed by rear heading sensor 810(2) also decreases and thus controller 820 controls rear actuator 808(2) to also move rear carriage 804(2) in the negative y direction.
Controller 820 may also store and/or determine the speed v. In one embodiment, a user (e.g., a rider of bicycle 850) enters the speed v to controller 820, where it is stored in memory and used by algorithm 822 to determine the lateral velocities vy(f) and vy(r). The user may enter the speed v to controller 820 via a graphical user interface of controller 820, or wirelessly (e.g., via Bluetooth or Wi-Fi) via a remote computing device (e.g., see remote computing device 2824 of
A scalar distance between where adapters 806(1) and 806(2) affix to bicycle 850 (i.e., front and rear dropouts of bicycle 850) is fixed by a geometry of bicycle 850. A longitudinal distance between rails 802(1) and 802(2) in the x direction is also fixed. In the example of
In one embodiment, front adapter 806(1) includes a flexible material that bends to position front adapter 806(1) longitudinally behind front rail 802(1), wherein front adapter 806(1) connects directly to front carriage 804(1) without longitudinal rail 816 and fork carriage 818. The flexible material may be a vertically-oriented spring that bends longitudinally with the heading angle of frame 854. In another embodiment, rear adapter 806(2) includes a flexible material that bends to position rear adapter 806(2) longitudinally ahead of rear rail 802(2), thereby reconciling the two distance constraints. In another embodiment, both adapters 806(1), (2) include a flexible material to longitudinally shift respective adapters 806(1), (2).
A pin 904 rotatable around a vertical rotation axis (i.e., along the z direction) protrudes from a top surface of fork carriage 818 and includes a pivot 905 that couples with adapter 806(1) and rotates around a horizontal rotation axis. Front heading sensor 810(1) couples with both fork carriage 818 and pin 904 to measure an angle of pin 904 in the x-y plane relative to the positive x direction, thereby measuring the front heading angle θf of fork 814.
Actuators 808 may be any type of linear actuator known in the art. For example, actuators 808 may be pneumatic actuators using a gas (e.g., air), hydraulic actuators using a liquid, or linear motors. In the example of
In one embodiment, front translation mechanism 812(1) includes a front lean sensor 911 that measures a front lean angle (pf of fork 814 with respect to the z direction. That is, lean sensor 911 senses an angle by which pivot 905 rotates. Algorithm 822 of controller 820 may include additional machine-readable instructions that, when executed by the processor of controller 820, control the processor to: (i) determine a front lateral acceleration based on the front lean angle (pf received from front lean sensor 911, and (ii) control front actuator 808(1) to move front carriage 804(1) according to the front lateral acceleration. In another embodiment, rear translation mechanism 812(2) includes a rear lean sensor (not shown) that senses a rear lean angle φr of frame 854 with respect to the z direction. Algorithm 822 may include additional machine-readable instructions that, when executed by the processor of controller 820, control the processor to: (i) determine a rear lateral acceleration based on the sensed rear lean angle φr, and (ii) control rear actuator 808(2) to move rear carriage 804(2) according to the rear lateral acceleration.
In one embodiment, algorithm 822 includes additional machine-readable instructions that, when executed by the processor of controller 820, control front and rear actuators 808(1) and 808(2) to laterally accelerate respective carriages 804(1) and 804(2) according to the respective front and rear lean angles φf, φr, to stabilize the front and rear lean angles φf, φr at zero degrees. That is, algorithm 822 and controller 820 cooperate with actuators 808(1) and 808(2), carriages 804(1) and 804(2), and lean sensors (e.g., front lean sensor 911) to form two feedback loops that balance bicycle 850 without a rider, and therefore without steering. This mode of operation of simulator 800, referred to herein as “acceleration-based control”, is analogous to the balancing of inverted pendulum 102 of
In some embodiments, simulator 800 switches between acceleration-based control and velocity-based control. For example, at the beginning of a simulation, a rider may enable acceleration-based control to assist the rider with balancing bicycle 850 before the rider begins pedaling. After the rider has mounted bicycle 850 and begins pedaling, simulator 800 then switches to velocity-based control to more accurately simulate riding of bicycle 850, for example, on a road. When the rider has finished the simulation, simulator 800 then switches back to acceleration-based control, balancing bicycle 850 to assist the rider with dismounting bicycle 850. In one embodiment, the transition between acceleration-based control and velocity-based control is determined by an action of the rider, such as pedaling. For example, when the rider begins pedaling bicycle 850, controller 820 detects the pedaling (e.g., with a pedaling sensor connected to bicycle 850) and switches from acceleration-control mode to velocity-control mode in response to the pedaling. In another embodiment, controller 820 switches from velocity-control mode to acceleration-control mode when controller 820 detects that the pedaling has stopped. To prevent controller 820 from inadvertently switching to acceleration-based control while the rider is coasting, controller 820 may implement a time delay such that controller 820 switches to velocity-control mode after controller 820 has detected that the pedaling has stopped for a specified time duration (e.g., 10 seconds). In one embodiment, the rider commands controller 820 to switch between acceleration-based and velocity-based modes via a button or switch electrically coupled to controller 820. Alternatively, the rider may command controller 820 to switch between modes via a graphical user interface of a remote computing device (see remote computing device 2824 of
While
While the example of
In one embodiment, method 1200 includes a delay step 1208 to wait for a predefined period. In one example of step 1208, controller 820 waits for 100 milliseconds. In another embodiment, method 1200 repeats steps 1202 through 1210 to periodically control the actuator to laterally move the carriage based on a changing speed v and/or heading angle θ. For example, as a rider changes the heading angle θ, method 1200 may periodically determine the heading angle θ, update the lateral velocity vy according to the determined heading angle θ, and control the actuator according to the updated lateral velocity vy.
Although simulator 800 assists with balancing bicycle 850, the ease of balancing bicycle 850 is reduced as compared to balancing a bicycle with wheels rolling on a flat surface (e.g., bicycle 600 of
In one embodiment, simulator 800, when used with bicycle 850, includes a spinning mass 910 that produces a torque to replicate the torque produced by a spinning bicycle wheel when the bicycle wheel is affixed to front fork 814 in the conventional manner. In the example of FIG. 9, spinning mass 910 rotates around an axle 912 that connects to one side of adapter 806(1). A motor 914, controllable by controller 820, connects to the axle to rotate spinning mass 910.
Spinning mass 910 may have any diameter, width, weight, and shape to replicate the torque produced by a spinning bicycle wheel. In the example of
While
In another embodiment, simulator 1100, when used with bicycle 600, includes at least one spinning mass, similar to spinning mass 910, that produces a torque to replicate the torque produced by front wheel 602 when front wheel 602 is spinning. The examples, configurations, and usage of spinning mass 910 described above for
As appreciated, actuators 808 may be controlled to simulate various levels of stability and control, far beyond those available on a real bicycle. In one embodiment, algorithm 822 controls actuators 808 to simulate a bicycle with front and/or rear wheel steering.
Embodiments with Moving Surfaces
Simulator 1400 includes a front roller 1402 with a front surface 1420 that supports front wheel 602 of bicycle 600 at front contact point 614. Front roller 1402 rotates about a laterally-oriented front rotation axis 1414 to move front surface 1420 longitudinally at front contact point 614, thereby rotating front wheel 602. When rotating, front wheel 602 laterally translates along moving front surface 1420 in response to steering of bicycle 600. That is, as bicycle 600 is steered (i.e., the front heading angle θf of front wheel 602 is changed), front wheel 602 laterally accelerates to translate laterally along moving front surface 1420.
Simulator 1400 also includes a rear drum 1404 with a rear surface 1422 that supports rear wheel 604 of bicycle 600 at rear contact point 616. Rear drum 1404 is rotatable about a laterally-oriented rear rotation axis 1416 parallel to front rotation axis 1414. When rear wheel 604 is rotated by pedaling, rear wheel 604 longitudinally moves rear surface 1422 at rear contact point 616 by applying a torque to rear surface 1422 at rear contact point 614 that rotates rear drum 1404 around rear rotation axis 1416.
Lateral motion of front wheel 602 moves fork 606 likewise, changing a heading of frame 608 by rotating rear wheel 604 around a vertical support axis that coincides with rear support point 616 (see rear support axis 612 in
In
Simulator 1400 also includes a longitudinal restraint mechanism 1408 that longitudinally restrains bicycle 600 such that front wheel 602 remains in contact with front surface 1420, and rear wheel 604 remains in contact with rear surface 1422. Longitudinal restraint mechanism 1408 prevents bicycle 600 from moving longitudinally off of front roller 1402 and rear drum 1404.
Longitudinal restraint mechanism 1408 includes an arm 1410 having a length extendable along a direction 1418. When bicycle 600 is upright (i.e., rear wheel 604 has a zero lean angle, as shown in
Longitudinal restraint mechanism 1408 also includes a turntable 1436 that supports bottom joint 1430. Turntable 1436 is rotatable in a direction 1438 about a vertical turntable axis parallel to the z direction. In one embodiment, the vertical turntable axis coincides with rear contact point 616 such that the turntable axis and the rear support axis (e.g., rear support axis 612 of
Longitudinal restraint mechanism 1408 also includes first and second carriages 1502(1) and 1502(2) that support turntable 1436 and are moveable along first and second linear guide rails 1406(1) and 1406(2), respectively. Thus, as rear wheel 604 laterally translates along rear surface 1422, longitudinal restraint mechanism 1408 laterally translates along guide rails 1406 likewise (see direction 1424). While the example of
When bicycle 600 is steered by a rider, turntable 1436 rotates in direction 1438 such that bottom rotation axis 1448 of bottom joint 1430 remains parallel to lean axis 702. Furthermore, top joint 1426 rotates along direction 1428, bottom joint 1430 rotates along direction 1432, and arm 1410 changes length along direction 1418, such that arm 1410 rotates about bottom rotation axis 1448. Thus, arm 1410 follows the motion and orientation of rear wheel 604 while preventing bicycle 600 from moving longitudinally (i.e., in the x direction).
Longitudinal restraint mechanism 1708 includes an arm 1714 with a first end having a joint 1716 that couples to linear guide 1706. Linear guide 1706 is a cylindrical bar with a guide axis 1704 oriented parallel to front and rear rotation axes 1414, 1416 such that joint 1716 is laterally moveable along linear guide 1706 in direction 1724 (e.g., the y direction). Joint 1716 allows arm 1714 to (i) rotate in a direction 1722 around guide axis 1704, (ii) twist in a direction 1718 around a longitudinal axis 1802 of arm 1714, and (iii) pivot in a direction 1720 around a pivot axis 1804 lying in the x-z plane. Pivot axis 1804 is perpendicular to longitudinal axis 1802 and guide axis 1704. When bicycle 600 does not lean and rear wheel 604 has a zero heading angle θr, longitudinal axis 1802 and guide axis 1704 are perpendicular. When bicycle 600 leans and/or rear wheel 604 has a non-zero heading angle θr, longitudinal axis 1802 and guide axis 1704 may be not perpendicular.
A second end of arm 1714 has a rolling-element bearing 1710 that connects to bicycle 600 such that arm 1714 is rotatable in a direction 1712 about a rotation axis 1902 of rear wheel 604. In
When bicycle 600 is steered by a rider in response to leaning, arm 1714: (i) laterally translates along linear guide 1706, (ii) twists around longitudinal axis 1802, (iii) rotates around rotation axis 1902 of rear wheel 604, (iv) rotates around guide axis 1704, and (v) pivots around pivot axis 1804, such that arm 1714 remains approximately parallel to a rotation plane of rear wheel 604. Thus, arm 1714 follows the motion and orientation of rear wheel 604 while preventing bicycle 600 from moving longitudinally (i.e., in the x direction).
A length of arm 1714 remains fixed during operation of simulator 1700. To accommodate different sizes of bicycle 600 and rear wheel 604, the length of arm 1714 may be adjusted. As shown in
In
In
Front surface 1420, whether implemented as a roller or belt, may be longitudinally moved by a motor 1440 controlled by a controller 1434. In the examples of
Controller 1434 includes a processor, memory, and interface hardware that controls motor 1440. Controller 1434 may store a value for the speed v. In one embodiment, a user (e.g., a rider of bicycle 600) enters a value of the speed v to controller 1434, where it is stored in the memory and used to control motor 1440 such that front surface 1420 moves longitudinally according to the speed v. The user may enter the speed v to controller 1434 via a graphical user interface of controller 1434, or wirelessly (e.g., Bluetooth or Wi-Fi) via a remote computing device (e.g., see remote computing device 2824 of
In some embodiments, controller 1434 controls motor 1440 to rotate front roller 1402 such that front surface 1420 moves faster than the speed v when a rider of bicycle 600 begins pedaling, advantageously assisting the rider in balancing bicycle 600 without the use of side rails and/or balance rails. In one such embodiment, where front and rear surfaces 1420, 1422 start at rest, the rider signals to controller 1434 to begin operation of simulator 1400, at which time motor 1440 angularly accelerates front roller 1402. After controller 1434 has detected, via front rotation sensor 1446, that the speed of front surface 1420 has reached the speed v, controller 1434 stops accelerating front roller 1402 to maintain front surface 1420 moving at the speed v. Controller 1434 then indicates to the rider (e.g., audibly with a tone, or visibly with a light) that front surface 1420 has reached the speed v. After receiving the indication, the rider may then begin pedaling bicycle 600 to move rear surface 1422, thereby angularly accelerating rear drum 1404. Thus, the rider begins balancing of bicycle 600 with front wheel 602 already rotating, assisting the rider with steering bicycle 600 while the rider subsequently rotates rear wheel 604 to accelerate rear surface 1422 up to the speed v.
In the above example, motor 1440 accelerates front surface 1420 to the speed v. In other embodiments, motor 1440 accelerates front surface 1420 to a speed greater than v. A rear rotation sensor 1444 may be connected to sense a rotation rate of rear drum 1404; when controller 1434 determines, via rear rotation sensor 1444, that the speed of rear surface 1422 has reached v, controller 1434 may then control motor 1440 to decelerate front surface 1420. When controller 1434 determines that the speed of front surface 1420 has slowed to v, controller 1434 then stops decelerating front roller 1402 to maintain front surface 1420 moving at speed v.
In another embodiment, a drive belt 1504 connects rear drum 1404 with front roller 1402 such that rear drum 1404 rotates front roller 1402 instead of motor 1440. When rear drum 1404 and front roller 1402 have the same diameter, drive belt 1504 rotates front roller 1402 at the same rotation rate as rear drum 1404, thereby ensuring that front and rear surfaces 1420, 1422 move at the same longitudinal speed (i.e., front surface 1420 moves at a longitudinal speed similar to a longitudinal speed of rear surface 1422).
In some embodiments, a resistance generator is used to resist longitudinal motion of rear surface 1422, thereby replicating drag, wind resistance, rolling resistance, and other effects acting on bicycle 600, and/or a rider thereon, when bicycle 600 is ridden outside on a road. In the example of
In another embodiment, electric motor 1442 rotates rear drum 1404 to rotate rear wheel 604 to assist the rider with balancing bicycle 600 while mounting and/or dismounting bicycle 600. For example, at the beginning of a simulation, controller 1434 may operate electric motor 1442 in motoring mode to rotate rear drum 1404 such that the rider mounts bicycle 600 with rear wheel 604 already rotating. After the rider begins pedaling, controller 1434 operates electric motor 1442 in the generator mode to apply a torque to rear drum 1404 that simulates a resistance force when riding bicycle 600 outside on a road. Controller 1434 may detect the pedaling (e.g., with a pedaling sensor connected to bicycle 600) to switch from the motoring mode to the generator mode in response to the pedaling.
Although not shown in
Method 2000 also includes a step 2008 to generate a value of the drag force FD from the speed v. In one example of step 2008, controller 1434 implements the model of drag by (i) squaring the value of the speed v, and (ii) multiplying the squared speed by a value of α. Method 2000 includes a step 2010 to provide a value of α. As one example of step 2010, controller 1434 accesses a value of α stored in the memory of controller 1434.
Method 2000 also includes a step 2012 to generate a value of simulated-drag torque τD from the drag force FD. In one example of step 2012, controller 1434 multiplies the value of drag force FD by the value of the radius rRD of rear drum 1404. Method 2000 includes a step 2014 to provide the value of rRD. As one example of step 2014, controller 1434 accesses the value of rRD stored in the memory of controller 1434.
Method 2000 also includes a step 2016 to control electric motor 1442 according to the value of the simulated-drag torque τD. In one example of step 2016, the processor of controller 1434 controls a digital-to-analog converter of controller 1434 that feeds a motor drive circuit (e.g., a pulse-width modulation (PWM) circuit) of controller 1434, the output of the motor drive circuit being electrically connected to electric motor 1442.
In one embodiment, method 2000 repeats steps 2002 through 2016 to periodically update the simulated-drag torque τD according to a changing speed v. In another embodiment, method 2000 includes a delay step 2018 to wait before repeating steps 2002 through 2016. In one example of step 2018, controller 1434 waits for 100 milliseconds. In other embodiments, step 2008 generates a value of drag force FD according to a model of drag that includes higher-order velocity terms (e.g., v3, v4, etc.), wherein the memory of controller 1434 stores additional coefficients for implementing the model. The user/rider may communicate the values of the friction coefficient α and/or the radius rRD of rear drum 1404 to controller 1434 via a graphical user interface of controller 1434, front panel controls of controller 1434, or a remote computing device wirelessly coupled with controller 1434 (e.g., see remote computing device 2824 of
In another embodiment, method 2000 includes controlling electric motor 1442 to simulate a headwind and/or tailwind. For example, a value for a longitudinal wind speed u may be stored in the memory of controller 1434, a positive value of u corresponding to a tailwind and a negative value of u corresponding to headwind. One model of drag that accounts for a headwind and tailwind represents the drag force FD by FD=α(v−u)2. In one example of step 2008, controller 1434 implements this model by (i) adding the wind speed u to the measured speed v to generate a relative speed, (ii) squaring the relative speed, and (iii) multiplying the squared relative speed by the value of α. In this embodiment, method 2000 includes a step 2020 to provide the value of the wind speed u. As one example of step 2020, controller 1434 accesses a value of u stored in the memory of controller 1434.
Method 2100 includes a step 2102 to generate a value of the rolling resistance force FR. In one example of step 2102, controller 1434 implements the rolling resistance model by multiplying the values of coefficient C and normal force N to generate a value of the rolling resistance force FR. Method 2100 also includes a step 2104 to provide a value of N, and a step 2106 to provide a value of coefficient C. As one example of step 2104, controller 1434 accesses a value of N stored in the memory of controller 1434. As one example of step 2106, controller 1434 accesses a value of C stored in the memory of controller 1434.
Method 2100 includes a step 2108 to generate a value of rolling resistance torque τR from the rolling resistance force FR. In one example of step 2108, controller 1434 multiplies the value of rolling resistance force FR by the value of the radius rRD of rear drum 1404. Method 2100 also includes a step 2110 to provide the value of rRD. As one example of step 2110, controller 1434 accesses the value of rRD stored in the memory of controller 1434.
Method 2100 includes a step 2112 to control electric motor 1442 according to the value of the rolling resistance torque τR. In one example of step 2112, the processor of controller 1434 controls a digital-to-analog converter of controller 1434 that feeds a motor drive circuit (e.g., a PWM circuit) of controller 1434, the output of the motor drive circuit being electrically connected to electric motor 1442.
Method 2200 includes a step 2208 that adds the drag force FD and rolling resistance force FR to generate a total resistance force FT. In one example of step 2208, the processor of controller 1434 adds a value of resistance force FR stored in the memory of controller 1434 and a value of the drag force FD stored in the memory of controller 1434. The processor may then store the resulting value of total resistance force FT in the memory of controller 1434.
Method 2200 includes a step 2210 to generate a total resistance torque τT from the total resistance force FT. In one example of step 2210, controller 1434 multiplies the total resistance force FT by the value of the radius rRD of rear drum 1404. Step 2012 of method 2000 and step 2108 of method 2100 are examples of step 2210. Method 2200 also includes a step 2212 to control electric motor 1442 according to the total resistance torque τT. Step 2016 of method 2000 and step 2112 of method 2100 are examples of step 2212.
In one embodiment, method 2200 repeats steps 2202 through 2212 to periodically update the drag force FD according to a changing speed v. When rolling resistance force FR depends neither on the speed v nor any other quantity that changes with time, rolling resistance force FR need not be recalculated with each iteration of method 2200. For example, a value for rolling resistance force FR may be calculated once and stored in the memory of controller 1434; step 2206 may then access the value of rolling resistance force FR from the memory of controller 1434 with each iteration of method 2200. Method 2200 may also include a delay step 2214 to wait before repeating steps 2202 through 2212. In one example of step 2214, controller 1434 waits for 100 milliseconds between iterations of method 2200.
Models of drag, headwind/tailwind, and rolling resistance presented above are representative of the types of physical forces that may act on bicycle 600, and the rider thereon, when bicycle 600 is ridden outside on a road. These models are not intended to be limiting, and models of other physical phenomena may be similarly simulated without departing from the scope hereof. For example, the resistance generator may be used to simulate forces due to cross-winds and/or riding bicycle 600 at an incline. In certain embodiments, when simulating physical forces that would accelerate bicycle 600 (e.g., a tailwind, or riding downhill), controller 1434 may at times operate electric motor 1442 in motoring mode to accelerate rear surface 1422 accordingly. While method 2200 is shown simultaneously simulating a drag force FD and a rolling resistance force FR, method 2200 may simulate any number and/or types of resistance forces, wherein step 2208 sums the resistance forces.
Method 2300 includes a step 2302 to retrieve the next value of the inclination angle. In one example of step 2302, controller 1434 accesses the next value of the inclination angle stored in the memory of controller 1434. Method 2300 also includes a step 2306 to generate a value of a motional force FM according to the inclination angle. In one example of step 2306, controller 1434 multiplies a weight of bicycle 600 and the rider mounted thereon by the sine of the inclination angle. Method 2300 also includes a step 2308 that provides a value of the weight. As one example of step 2308, controller 1434 accesses a value of the weight stored in the memory of controller 1434.
Method 2300 also includes a step 2310 to generate a value of motional torque τM from the motional force FM. In one example of step 2310, controller 1434 multiplies the value of motional force FM by the value of the radius rRD of rear drum 1404. Method 2300 includes a step 2312 to provide the value of rRD. As one example of step 2312, controller 1434 accesses the value of rRD stored in the memory of controller 1434.
Method 2300 also includes a step 2314 to control electric motor 1442 according to the value of the motional torque τM. In one example of step 2314, the processor of controller 1434 controls a digital-to-analog converter of controller 1434 that feeds a motor drive circuit (e.g., a PWM circuit) of controller 1434, the output of the motor drive circuit being electrically connected to electric motor 1442.
In one embodiment, method 2300 repeats steps 2302 through 2314 to periodically update the motional torque τM according to a different value of inclination angle. Method 2300 may also include a delay step 2316 to wait before repeating steps 2302 through 2314. In one example of step 2316, controller 1434 delays for 100 milliseconds. In another example of step 2316, controller 1434 monitors the speed of rear surface 1422 (e.g., the rotation rate of rear drum 1404) and computes a simulated distance traveled by the rider on bicycle 600; controller 1434 delays until the simulated distance has reached a value stored in the memory of controller 1434, wherein controller 1434 delays according to the simulated speed of bicycle 600, as generated by the rider.
Embodiments with Bicycle Trainers
Rear translation mechanism 2504 also includes a turntable 2604 rotatable around a vertical turntable axis 2702, and a rolling-element bearing 2606 rotatable around a lean axis 2608. Turntable 2604 and rolling-element bearing 2606 are laterally centered such that turntable axis 2702 and lean axis 2608 intersect. Furthermore, transfer wheel 2704 is positioned to coincide with turntable axis 2702 beneath lean axis 2608, as shown in
Simulator 2500 includes front roller 1402, described above for simulators 1400 and 1700 of
Lateral motion of front wheel 602 moves fork 606 likewise, changing a heading of frame 608, stationary trainer 2502, and platform 2506 by rotating transfer wheel 2704, via turntable 2604, around turntable axis 2702. Transfer wheel 2704, when rotating about its axle, laterally translates along a longitudinally-moving rear surface 2618 of rear drum 2612 in response to the change of heading. That is, transfer wheel 2704 laterally accelerates along moving rear surface 2618.
Rear translation mechanism 2504 includes carriages 2610 that support turntable 2604 and are moveable along first and second linear guide rails 2602(1) and 2602(2). Thus, as transfer wheel 2704 laterally translates along rear surface 2618, rear translation mechanism 2504 laterally translates likewise along guide rails 2602 while preventing bicycle 600, stationary trainer 2502, and platform 2506 from moving longitudinally.
In one embodiment, rear translation mechanism 2504 includes a plurality of springs 2614 that provide a restoring force to return platform 2506 to a horizontal orientation (i.e., zero lean angle), thereby assisting the rider of bicycle 600 with balancing. In the example of
To accurately replicate riding of bicycle 600 on a surface, stationary trainer 2502 may be positioned on platform 2506 such that a support axis of rear wheel 604 (see rear support axis 612 of
While
In some embodiments, simulator 2500 excludes rear drum 2612 and transfer wheel 2704, advantageously eliminating the need for motor 2616 to rotate rear drum 2612. In these embodiments, rear translation mechanism 2504 is supported only by guide rails 2602 via carriages 2610, and laterally translates along guide rails 2602 due to oscillatory leaning of bicycle 600 caused by pedaling. Specifically, when a rider pedals bicycle 600, the rider may control bicycle 600 to lean left-and-right in an oscillatory way that is synchronized with the rider's cadence. This oscillatory leaning can be observed, for example, when a cyclist rides out of the saddle during a sprint. By changing the amplitude of the oscillatory leaning (i.e., how far to the left and right the rider causes bicycle 600 to lean with each pedal stroke), the rider can control frame 608 to laterally translate, in turn causing the front heading angle of bicycle 600 to change. In response to this change of the front heading angle, rotating front wheel 602 laterally translates along moving front surface 1420. Thus, bicycle 600 can be balanced without steering, similarly to how a rider steers and balances a bicycle when riding without hands.
Electronics
Controller 2800 includes a first sensor input circuit 2812 that receives a first sensor signal 2813 from a first sensor, and a second sensor input circuit 2814 that receives a second sensor signal 2815 from a second sensor. Each sensor may be an angle sensor (e.g., front and rear heading sensors 810(1), (2), front lean sensor 911), rotation sensor (e.g., rotation sensors 1446 and 1444), torque sensor (e.g., torque sensor 1452), orientation sensor (e.g., accelerometer), or other type of sensor. While
Controller 2800 also includes a first controller circuit 2816 that outputs a first control signal 2817 to a first actuator, and a second control circuit 2818 that outputs a second control signal 2819 to a second actuator. Each actuator may be a linear actuator (e.g., front and rear actuators 808(1), (2) of
Sensor input circuits 2812 and 2814 may amplify, filter, and/or digitize respective sensor signals 2813 and 2815. Depending on the type of sensor, each of sensor input circuits 2812 and 2814 may be configured for two-terminal sensing, four-terminal Kelvin sensing, a Wheatstone bridge, or another type of impedance, voltage, or current measurement technique. Sensor input circuits 2812 and 2814 may include difference amplifiers, instrumentation amplifiers, and/or similar components for analog signal conditioning. In some embodiments, sensor input circuits 2812 and 2814 include filters to reject noise and/or interference from respective sensor signals 2813 and 2815. When sensor signals 2813 and 2815 are analog signals, sensor input circuits 2812 and 2814 may include analog-to-digital converters (ADCs) to digitize respective sensor signals 2813 and 2815. When sensor signals 2813 and 2815 are digital signals, sensor input circuits 2812 and 2814 may include receivers to receive respective digital signals 2813 and 2815.
Depending on the type of actuator, each of controller circuits 2816 and 2818 may be configured to output an analog voltage or current, wherein the corresponding control signals 2817 and 2819 are analog control signals. Each of controller circuits 2816 and 2818 may be configured to output a digital signal, wherein the corresponding control signals 2817 and 2819 are digital control signals. In one embodiment, each of controller circuits 2816 and 2818 is a PWM circuit configured to drive a motor. In another embodiment, when each of controller circuits 2816 and 2818 is configured to output an analog signal, controller circuits 2816 and 2818 include a digital-to-analog converter (DAC) to generate corresponding analog control signals 2817 and 2819.
RF transceiver circuit 2820 may use one or more wireless protocols, such as Bluetooth, Wi-Fi, and ZigBee. In certain embodiments, RF transceiver circuit 2820 transmits wireless communication 2836 to remote device 2824 using any of several protocols that stream data over networks, such as User Datagram Protocol (UDP), Transmission Control Protocol (TCP), Hypertext Transfer Protocol (HTTP), Real-Time Streaming Protocol (RTSP), and Real-Time Transport Protocol (RTP). In certain embodiments, RF transceiver circuit 2820 may implement a Bluetooth profile such as Human Interface Device Profile (HID), Hands-Free Profile (HFP), LAN Access Profile (LAP), and a Bluetooth Advanced Audio Distribution Profile (A2DP). For example, RF transceiver circuit 2820 may use A2DP to stream front and rear heading angles θf and θr via a single wireless channel to remote device 2824.
Microprocessor circuit 2804 may include at least one central processing unit (CPU), graphics processing unit (GPU), digital signal processor (DSP), field-programmable gate array (FPGA), or other type of integrated circuit capable of performing logic, control, and input/output operations. Microprocessor circuit 2804 may include a mixed-signal integrated circuit, such as a System-on-Chip (SoC) or microcontroller unit (MCU), that combines a processor, memory, and input/output interfaces on a single chip. Microprocessor circuit 2804 may also include a memory controller, bus controller, graphics processing unit, and/or other components that manage data flow between microprocessor circuit 2804, memory 2806, and other components communicatively coupled with bus 2802.
Memory 2806 may include both volatile memory (e.g., RAM, SRAM, etc.) and nonvolatile memory (e.g., ROM, FLASH, etc.). Instructions 2808 include machine-readable instructions that, when executed by microprocessor circuit 2804, control operation of controller 2800. Instructions 2808 may include at least one algorithm 2832, as well as operating system instructions. Algorithm 2832 is selected based on desired functionality of controller 2800, as described in further detail below.
In
Microprocessor circuit 2804 executes instructions 2808 (e.g., algorithm 2832) to compute values of front and rear lateral velocities vy(f) and vy(r) from speed v and respective heading angles θf and θr. Microprocessor circuit 2804 then sends values of front and rear lateral velocities vy(f) and vy(r) over bus 2802 to respective controller circuits 2816 and 2818, which output corresponding control signals 2817 and 2819 according to the received values of front and rear lateral velocities vy(f) and vy(r), respectively. In one embodiment, microprocessor circuit 2804 sends values of lateral velocities vy(f) and vy(r) and/or heading angles θf and θr over bus 2802 to RF transceiver circuit 2820 for transmission, via antenna 2822, to remote device 2824 as wireless communication 2836.
Controller 2800 may wirelessly transmit to remote device 2824 data stored in memory 2806. Remote device 2824 receives data in wireless communication 2836 and may display the received data to a user via a display 2838 of remote device 2824. In certain embodiments, remote device 2824 may store the received data for future processing and/or display. For example, controller 2800 may wirelessly transmit to remote device 2824 values of speed v of rear moving surface 1422, and corresponding values of time at which each value of speed v was sensed (e.g., by one of sensor input circuits 2812 and 2814); remote device 2824 may display these values on display 2838 as a rolling chart such that a rider may monitor speed v over time. When controller 2800 operates with a resistance generator, controller 2800 may wirelessly transmit to remote device 2824 values of the torque applied to electric motor 1442, along with corresponding values of time at which each torque was generated by electric motor 1442; remote device 2824 may display these values on display 2838 as a rolling chart such that a rider may observe changes in the simulated resistance force over time, thereby monitoring a level of effort required to overcome the resistance force.
In certain embodiments, RF transceiver circuit 2820 may also wirelessly receive, from remote device 2824 via antenna 2822, instructions and/or data to store in memory 2806. For example, the user may interact with an app running on remote device 2824 to modify values stored in data 2810. For example, when data 2810 includes values for a resistance model (e.g., a model of wind resistance or rolling resistance), the user may enter values for the normal force N, friction coefficient α, and/or coefficient C into remote device 2824, which wirelessly transmits the values to controller 2800 for storage in data 2810.
In some embodiments, controller 2800 is further configured such that a rider may participate in a massively multiplayer online game (MMOG), such as a massively multiplayer online racing (MMOR) game. As shown in the example of
Changes may be made in the above methods and systems without departing from the scope hereof. It should thus be noted that the matter contained in the above description or shown in the accompanying drawings should be interpreted as illustrative and not in a limiting sense. The following claims are intended to cover all generic and specific features described herein, as well as all statements of the scope of the present method and system, which, as a matter of language, might be said to fall therebetween.
This application claims priority to U.S. Provisional Application No. 62/701,291, filed Jul. 20, 2018, which is incorporated herein by reference in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2019/042646 | 7/19/2019 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62701291 | Jul 2018 | US |
