Transportation device having multiple axes of rotation and auto-balance based drive control

Abstract

A transportation device that has two or more wheel axes, auto-balance based drive control, and a rider platform which adjusts its auto-balancing neutral pitch to follow the incline of the riding surface based on incline data from sensors located on a non-pivoting part of the device. Possible forms of the transportation device include a scooter, a skateboard-like device, and a device with continuous tracks.

Description

FIELD OF THE INVENTION

The present invention relates to vehicles that use an auto-balancing system to control vehicle drive and, more specifically, to multi-wheel axis vehicles that employ auto-balancing.

BACKGROUND OF THE INVENTION

Various vehicles are known in the art that use auto balancing and they include the Segway, Solowheel and Hovertrax, taught in U.S. Pat. Nos. 6,302,230; 8,807,250; and 8,738,278, respectively, which are hereby incorporated by reference.

In these devices, there is generally one principal axis of rotation. The vehicle performs auto-balancing by speeding up or slowing down in an attempt to bring the platform surface of the vehicle to a steady-state balanced position.

The present invention provides a device with multiple axes of rotation, one forward of the other, such as a front wheel and a rear wheel. A movable rider platform with an associated position sensor permits a user to control the vehicle by leaning forward or rearward. The device is configured to attempt to bring the rider platform into steady state balance, accelerating when the platform is tilted to a greater degree and decelerating as the rider platform is tilted less.

This produces a vehicle where platform movement can be independent of the position of the vehicle (or vehicle frame). Thus, it is the rider balance, not the vehicle balance, that is used in a feedback loop to control speed.

Multiple axes auto-balance driven vehicles have several advantages over single axis auto-balance vehicles. One is that they can travel faster (compare a scooter to a Solowheel or Segway). Another is that they can carry heavier loads. Yet another is that they are generally more stable, easier to ride and safer. However, in auto-balance driven vehicles in which the rider platform can move independently of the main body of the vehicle or the vehicle frame, it is possible for the rider platform to unwantedly come into contact with other parts of the vehicle when the riding surface is inclined. Thus, there is a need in two-axis auto-balance vehicles to provide a rider platform which is configured to continuously its neutral pitch in response to changes in incline of the riding surface so that there is always adequate distance between the rider platform and other parts of the vehicle.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide a transportation device that has two (or more) axes of rotation, auto-balance based speed control, and a rider platform which adjusts its auto-balancing neutral pitch to follow the incline of the riding surface.

It is another object of the present invention to provide scooter- or skateboard-like devices having auto balance based drive control that are designed to enable the rider platform to adjust its neutral pitch according to the incline of the riding surface.

It is also an object of the present invention to provide continuous track transportation devices having auto balance based drive control that are designed, electronically and/or mechanically, to enable the rider platform to adjust its neutral pitch according to the incline of the riding surface.

These and related objects of the present invention are achieved by use of a transportation device having multiple axes of rotation and auto-balance based drive control as described herein.

The attainment of the foregoing and related advantages and features of the invention should be more readily apparent to those skilled in the art, after review of the following more detailed description of the invention taken together with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of an embodiment of a scooter device having an auto-adjusting dynamically balanced rider platform.

FIG. 2 is a perspective view of an embodiment of a skateboard-like device having an auto-adjusting dynamically balanced rider platform.

FIG. 3 is another perspective view of the embodiment of FIG. 2 with front wheels removed.

FIG. 4 is a perspective view of an embodiment of a continuous track device having an auto-adjusting dynamically balanced rider platform.

FIG. 5 is another perspective view of the embodiment of FIG. 4.

FIG. 6 is an embodiment of another continuous track device having an auto-adjusting dynamically balanced rider platform.

FIG. 7 is a perspective view of another embodiment of a scooter device having an auto-adjusting dynamically balanced rider platform.

FIG. 8 is a perspective view of another embodiment of a scooter device having an auto-adjusting dynamically balanced rider platform.

DETAILED DESCRIPTION

Referring to FIG. 1, a two-axis scooter device 10 having auto-balance or “rider-balance” based drive control with an auto-adjusting rider platform in accordance with the present invention is shown. Scooter 10 may include a front wheel 20 and a rear wheel 30 arranged in line, each with an axis of rotation 21,31, respectively. A connecting frame 40 is preferably coupled between the wheels. In the embodiment of FIG. 1, connecting frame 40 has a curved section 41 about a portion of front wheel 20 and a flatter or straighter section 42 extending from the curved section to the rear wheel. A handlebar structure 50 may ascend from the front wheel. It may include forks 51 coupled to the front wheel, a steering shaft 53 and a steering handle 54, as known in the art.

A rider platform 60 is preferably mounted on connecting frame 40 and configured for fore-aft rotational movement. rider platform 60 may include a rider platform 61 disposed towards a top surface thereof. The rider platform is preferably mounted about a pivot axis 65 for fore-aft movement as indicated, for example, by arrow B and may include a drive motor 64 comprising a rotor and a stator, the rotor being coupled to a drive head 62. The drive head drives a belt or chain 63 which in turn drives a complementary drive wheel assembly 34, which may be a wheel, sprocket, cassette with gears or other. Rotation of drive wheel assembly 34 turns rear wheel 30. Motor 64 may include a speed reduction system.

Rider platform 60 preferably includes a position sensor 67, which is preferably a gyroscopic sensor, and a control circuit 68. The gyroscopic sensor may detect the fore-aft tilt position of the platform, relatively to horizontal. The control circuit drives the drive motor and hence rear wheel 30 to dynamically balance rider platform 61 based on the fore-aft tilt angle sensed by the position sensor, as known for auto-balancing vehicles such as those disclosed in U.S. Pat. Nos. 8,807,250 and 8,738,278, issued to Chen. Motor 64 may have a drive axis that is collinear with the axis of rotation of the platform, or be otherwise arranged.

Unlike self-balancing vehicles of the prior art having only a single wheel axis wherein the wheel or parallel wheels are driven to balance the entire vehicle, the device of FIG. 1 has two wheel axes, and wheels 20,30 are both in contact with the riding surface. The main body of the vehicle will thus be inclined upward or downward when riding on inclined surfaces. To prevent rider platform 60 from unwantedly coming into contact with other parts of the vehicle when riding on inclines, rider platform 60 may be configured to automatically adjust its neutral pitch to match the incline of the riding surface instead of having a horizontal position as its neutral pitch at all times. In this way, the rider platform is dynamically balanced to an inclined pitch angle whenever the riding surface is inclined, and will therefore maintain adequate distance from other parts of the vehicle. This may be achieved by providing a surface incline position sensor (preferably an accelerometer) on a rigid part of the device which does not undergo fore-aft pitch changes relative to the riding surface, such as connecting frame 40. This surface incline position sensor measures the position of the vehicle as it follows the riding surface, and provides vehicle position data for the control circuit to use as a reference to adjust the neutral pitch angle of the rider platform to follow the incline of the riding surface.

FIGS. 2-3 show an embodiment of a two-axis skateboard-like device 110 having auto-balance or “rider-balance” based drive control in accordance with the present invention. In this embodiment motor 164 is mounted separately from rider platform 160, but the motor is still linked with the rider platform such that the two can pivot together in unison. The pivoting axis of rider platform 160 is centered on a platform pivot point 181 which can slide a short distance forward and backward along a connecting frame 140. The position sensor can be located either on or in the rider platform, or on or in the motor. rider platform 160 is rotatably connected to motor arms 180, which are disposed horizontally, mechanically linking the rider platform to motor 164 so that as the rider platform tilts forward or backward, the change in position is translated through up and down movement of motor arms 180 into a forward or backward pivoting of motor 164. To accommodate changes in the relative angles and distance between different parts of the device during these actions, platform pivot point 181 slides along connecting frame 140 in conjunction with the tilting of rider platform 160.

Low-friction material can be provided at the sliding contact area, or a roller with bearings may be provided on pivot point 181. Alternatively, the pivot point can be pivotably connected to connecting frame 140 instead of being slidable, and rider platform 160 may have a portion which is flexible enough to allow forward and backward motion of motor arms 180 and motor 164 while pivot point 181 remains in place.

Motor 164 can drive the front wheels, the rear wheels, or both through a transmission. In other embodiments there may be a first motor driving the front wheels and a second motor driving the rear wheels, in which case both motors can be pivotably connected to the rider platform.

Because the length of motor arm 180 is much shorter than the length of rider platform 160, any angle change of the motor arm relative to connecting frame 140 causes a much lesser angle change of rider platform 160. This allows rider platform 160 to remain substantially parallel to the connecting frame (which is always parallel to the riding surface) when the riding surface is inclined. In general, the distance between the pivoting axis of the rider platform and a point of connection between the rider platform and the stator of the motor is longer than the distance between the pivoting axis of the motor and the same point of connection between the rider platform and the stator of the motor by a difference. The difference must be great enough that when the drive motor is at its neutral balanced pitch angle, the rider platform is substantially parallel to the riding surface. This is a mechanical means for automatically adjustment of the neutral balancing pitch of rider platform 160 to avoid the rider platform unwantedly coming into contact with other parts of the vehicle when riding on an inclined surface.

Another way to achieve auto-adjustment of the neutral balancing pitch of the rider platform in response to inclined riding surfaces is to provide a surface incline position sensor on a non-pivoting and non-sliding part of the device, such as on connecting frame 140, to provide data about the incline of the riding surface for automatically adjusting the neutral pitch of rider platform 160 according to the incline of the riding surface as described for the embodiment of FIG. 1.

FIG. 4 shows an embodiment of a scooter device 210 having rider-balance drive control in accordance with the present invention. Device 210 includes three pairs of wheels 320 arranged in parallel pairs each with an axis of rotation 221. Other embodiments may have a different number of wheels, and although this embodiment has each wheel's axis collinear with an opposing wheel's axis, other embodiments may have wheels which are coaxially arranged.

The wheels on one side of the vehicle are connected by a left continuous track 215, and the wheels on the other side are connected by a right continuous track 216. The device of this embodiment is bidirectional and thus left and right are chosen arbitrarily, but other embodiments may be directional and have a designated forward direction and rearward direction.

Wheels 220 are driven by drive motors 264 and in turn drive the tracks (similar to a tank, bulldozer or tractor). Two drive motors are provided, one to drive at least one of the left-side wheels, and one to drive at least one of the right-side wheels. The motors can drive the wheels through belts, chains, gears or other methods. There may be speed reduction provided between the motors and the wheels. In this manner differential wheel and track driving can be achieved to provide turning. The tracks 215,216 are shown below a platform frame 260.

The platform frame 260 has two movable rider platform sections 291,292 provided therein. These rider platform sections are placed within and pivotably coupled to platform frame 260, and are capable of tilting in the fore-aft dimension independently of each other and of platform frame 260. Each rider platform section 291,292 includes a position sensor. A control circuit and position sensors are provided as discussed elsewhere herein. Each rider platform section includes or is rigidly coupled to one of the two drive motors. In this embodiment the output driving axle of the motor is collinear with the rider platform section's fore-aft pivoting axis. Other embodiments may have alternative configurations in which the motor's driving axle is not collinear with the rider platform section's pivoting axis.

In use, the movable rider platform sections 291,292 may be tilted forward or backward independently and relative to the platform frame 260. The drive motors are configured to independently drive the left and right wheels to achieve independent driving of tracks 215,216 to dynamically balance each rider platform section based on their respective fore-aft tilt angles—the fore-aft tilt position of the left rider platform section controlling the left side and the fore-aft tilt position of the right rider platform section controlling the right side.

FIGS. 5-6 show another embodiment of a scooter device 310 having rider-balance drive control in accordance with the present invention. This embodiment is similar to the device of FIG. 4, except that the platform frame is divided into a left platform frame 361 and a right frame 362, pivotably coupled to one another so that the platform frames may pivot in the fore-aft dimension relative to each other to independently follow the incline of the riding surface on their respective sides of the vehicle. The left wheels 321 are coupled to left platform frame 361 and the right wheels 331 are coupled to right platform frame 362. This configuration allows the left and right continuous tracks 315,316 to accommodate differently angled ground surfaces. The connection between left and right platform frames 361,362 may be achieved with mechanically pivoting joints, or by a slightly flexible connecting structure without discrete joints or pivot points.

Various other motor configurations and wheel arrangements are possible in other embodiments. For instance, the vehicle can have any number and distribution of wheels as long as there are at least two non-collinear wheel axes; the motor or multiple motors may be configured to drive any one or more of the wheels; and the wheels can have continuous tracks or can be without continuous tracks.

In order for the rider platform sections to each adjust its neutral pitch according to the incline of the riding surface as described for the device of FIG. 1, left and right surface incline position sensors may be provided for the left and right sides of the platform frame respectively. The same function may alternatively be achieved by configuring the connection between the rider platform sections and the motors similarly to those described in FIGS. 2-3 or below in FIGS. 7-8.

Since the embodiments of FIGS. 4-6 may be heavy, the rider's weight may not provide sufficient force for effectively tilting the rider platform sections forward and backward against the force needed to drive the vehicle. To solve this problem, any motor speed reduction which has been provided (gears for example) may be reduced or eliminated and moved to outside of the rider platform sections. This will reduce the torque needed to tilt the rider platform sections. Different distributions of speed reduction between the rider platform sections and the wheels can increase or decrease the counter-force from the motor. For instance, if more stages of gears are provided in the wheels and less stages of gears are put in the rider platform sections, less rider weight will be required to tilt the rider platform sections. The motors (with or without speed reduction) on the rider platform sections can drive a gearbox 366 placed outside of the rider platform sections through a shaft. The speed reduction can be achieved using gears, a belt (e.g., belt 270 in FIG. 4), friction, or other methods.

FIG. 7 shows an embodiment of a scooter device 410 having rider-balance drive control according to the present invention. Scooter device 410 includes a rider platform 460 disposed between wheels 420,430 and capable of tilting in the fore-aft dimension. A motor 464 drives wheel 420 through a gear speed reduction (inside gearbox 469). rider platform 460 is connected to motor 464 through a motor arm 480 coupled to motor 464, and a platform arm 483 coupled to rider platform 460. Motor arm 480 is coupled to motor 460 at one end and at its other end has a pin 484 which is capable of sliding forward and backward within a slot 485 provided within platform arm 483. This configuration links tilting of the rider platform to the motor so that they always undergo pitch changes in unison, while pin 484 slides within slot 485 to accommodate changes in distance between the rider platform and the motor during tilting. This accomplishes a function similar to the sliding point arrangement of the embodiment of FIG. 2-3.

FIG. 8 shows another embodiment of a scooter device 510 having rider-balance drive control according to the present invention. Scooter device 510 is similar to the embodiment of FIG. 7, but instead of a pin-and-slot design, it has an additional connecting arm 586 coupled at one end to motor arm 580 and at its other end to platform arm 583. This is an alternative to the sliding pin-and-slot design of FIG. 7 and accomplishes the same function of accommodating changes in distance between the motor and the platform during tilting actions.

Suitable batteries and their placement are known in the art, though the battery may be placed under the platform and/or coupled to the frame, etc.

While the invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modification, and this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice in the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth, and as fall within the scope of the invention and the limits of the appended claims.

Claims

1. A transportation device, comprising: a first rotary device with a first axis of rotationa second rotary device with a second axis of rotation that is different from the first axis of rotation;a first drive motor, having a rotor and a stator, that drives the first rotary device;a movable control member, pivotable in fore-aft;a first position sensor that senses a position of the movable control member; anda control circuit that drives the first motor towards auto-balancing the movable control member toward a predetermined neutral balancing angle based on data from the first position sensor;

2. The transportation device of claim 1, further comprising a surface incline position sensor that senses any deviation from horizontal of a line drawn from the first rotary device to the second rotary device, wherein the continuous adjustment of the neutral balancing angle of the movable control member is achieved by continuously setting the neutral balancing angle to be substantially equal to the incline of the riding surface at any given time.

3. The transportation device of claim 1, wherein the distance between the pivoting axis of the movable control member and a point of connection between the movable control member and the stator of the drive motor is longer than the distance between the pivoting axis of the drive motor and the same point of connection between the movable control member and the stator of the drive motor by a difference, the difference being great enough that when the drive motor is at its neutral balanced pitch angle, the movable control member is substantially parallel to the riding surface.

4. The transportation device of claim 3, wherein the difference is at least a factor of 2.

5. The transportation device of claim 3, wherein a line drawn between the pivoting axis of the drive motor and the point of connection between the movable control member and the stator of the drive motor is substantially horizontal when the drive motor is at its neutral balanced pitch.

6. The transportation device of claim 5, wherein a line drawn between the pivoting axis of the drive motor and the point of connection between the movable control member and the stator of the drive motor is within 60 degrees above or below horizontal.

7. The transportation device of claim 1, wherein the movable control member is directly coupled to the stator of the drive motor.