GB2539882A

GB2539882A - Transportation device

Info

Publication number: GB2539882A
Application number: GB1511134.7A
Authority: GB
Inventors: Artemev Timur
Original assignee: Individual
Current assignee: Individual
Priority date: 2015-06-24
Filing date: 2015-06-24
Publication date: 2017-01-04
Also published as: GB201511134D0

Abstract

A powered transportation device comprises: a hubless wheel having an inner rim; a drive arrangement 135 positioned inside the void defined by the inner rim of the hubless wheel and adapted to drive rotation of the hubless wheel; at least one support platform for supporting a load for transportation; and a control system adapted to permit gerbiling (G) of the drive arrangement and further adapted to control the degree of gerbiling (G) of the drive arrangement.

Description

TRANSPORTATION DEVICE

Field of Invention

The present invention relates to powered transportation devices and more particularly to powered transportation devices employing at least one hubless wheel.

Background to the Invention

Powered vehicles employing one or more hubless wheels for transporting loads, such as packages or individuals, are known. Such vehicles include twowheeled vehicles and single-wheeled vehicles (i.e. unicycles).

For example, in a powered self-balancing unicycle, an electronic or mechanical system that controls the wheel in the appropriate direction is typically used to achieve fore-and-aft balance. This type of automatic fore-and-aft balance technology is well known and described, for example, in United States Patent number 6,302,230. A sensor and electronic equipment are typically provided. Information detected by the sensor and the electronics is relayed to a motor. The motor drives the wheel in the appropriate direction and at sufficient speed to maintain fore-and-aft balance.

The market for powered vehicles employing one or more hubless wheels is strongly dependent on the weight of the product, which also influences the cost of manufacture of the device. There is therefore always a need to reduce production costs where possible.

Summary of the invention

According to a first aspect of the invention, there is provided a powered transportation device comprising: a hubless wheel having an inner rim; a drive arrangement positioned inside the void defined by the inner rim of the hubless wheel and adapted to drive rotation of the hubless wheel; at least one support platform for supporting a load for transportation; and a control system adapted to permit gerbiling of the drive arrangement and further adapted to control the degree of gerbiling of the drive arrangement.

Gerbiling is widely known to be an issue in devices (such as “monowheels”) that employ one or more hubless wheels which are driven by/using the inner rim of the hubless wheel(s). In a monowheel, for example, if the driver accelerates or brakes too hard, it is possible that the force applied overcomes the force of gravity keeping the rider at the bottom of the wheel, thus sending the rider spinning around the inside of the wheel. This is therefore referred to as gerbiling because it has some similarity to the situation of a gerbil running too quickly inside of a hamster wheel. The risk of gerbiling in a monowheel is therefore widely regarded as something that is avoided at all costs.

Thus, completely against the grain of unconventional thinking (which is to prevent gerbiling), embodiments propose the unconventional concept of permitting gerbiling of the drive arrangement. In particular, embodiments are adapted to allow gerbiling of the drive arrangement to occur, for example, in response to acceleration or deceleration of the transportation device.

There is proposed a powered transportation device having a drive arrangement that is permitted to undergo gerbiling. In embodiments, the drive arrangement may be permitted to undergo gerbiling so as to alter the centre of gravity of the device. Such gerbiling of the drive arrangement may be permitted when the wheel rapidly or suddenly accelerates or decelerates, for example due to the wheel(s) hitting a small bump or obstacle. Embodiments may therefore transfer a linear momentum (e.g. in the forward or backward direction) of the wheel(s) into movement of the drive arrangement when the device hits a small bump or obstacle. Thus, at least some of the forward running momentum of the device can be translated into movement of the drive arrangement around the inner rim of the hubless wheel(s) so that the drive arrangement moves away from its rest position at the bottom (e.g. lowermost) portion of the inner rim.

Such movement of the drive arrangement around the inner rim away from its rest position at the bottom is commonly referred to as “gerbiling” and may result in the device’s centre of gravity moving. Such movement of the centre of gravity may help, for example, towards propelling and/or lifting the device over an obstacle and thus reduce an amount of torque/power required of the drive arrangement. Embodiments may therefore reduce or alleviate power or torque requirements of the drive arrangement. Such reduction of required torque, for example, may enable a smaller, lighter and/or cheaper motor to be employed, thus reducing the cost and/or weight of the device.

Embodiments may also help improve device safety by reducing (e.g. damping) the effect of hitting a sudden acceleration or deceleration (caused by hitting a bump or obstacle for instance). For example, a sudden deceleration of the device may not be mirrored by the drive arrangement and support platform(s). Instead, gerbiling of the drive arrangement may mean that the load or user experiences more gradual acceleration/deceleration.

Embodiments employ the realisation that traveling momentum of a load may be used to alter the centre of gravity of the device, and the change of centre of gravity may help to pull the device forwards and upwards over a curb for example. It is proposed to convert or translate linear momentum of the device/user into movement of the centre of gravity of the device by enabling or permitting gerbiling of the drive arrangement when the wheel or device suddenly decelerates (due to hitting a bump, small step, obstacle, etc.). The adjustment of the centre of gravity may help to overcome the bump or obstacle so that the amount of torque required by the drive arrangement may be reduced when compared to conventional devices hitting the same bump or obstacle. Embodiments may therefore provide a powered transportation device that employs a smaller, lighter and/or cheaper motor than conventional devices.

Embodiments may further comprise a coupling arrangement adapted to couple the support platform to the drive arrangement and further adapted to allow the support platform to move relative to the drive arrangement in response to gerbiling of the drive arrangement. Movement of the support platform relative to the drive arrangement may be used to alter or manipulate the centre of gravity of the loaded device, and the change of centre of gravity may help to pull the device forwards and upwards over a curb for example. In other embodiments, change of centre of gravity of the load may help to balance the overall. Adjustment of the centre of gravity of the load may alter the centre of gravity of the overall loaded device (i.e. the centre of gravity of the device and its load) so that the stability of the device is improved.

For example, the coupling arrangement may be adapted to slide the support platform relative to the drive arrangement in response to gerbiling of the drive arrangement so as to alter the centre of gravity of the device.

Embodiments may comprise an orientation arrangement adapted to maintain the support platform in a substantially constant orientation when the drive arrangement undergoes gerbiling. Embodiments may therefore maintain an upper (user/load-supporting) surface of the support platform(s) in a substantially horizontal configuration so that the support platform does not tilt when the drive arrangement undergoes gerbiling. This may help to prevent the load from losing its balance, and may therefore improve the safety and/or usability of the device. By way of example, the support platform orientation arrangement may comprise a rotatable mount upon which the support platform is supported such that the support platform is adapted to rotate relative to the drive arrangement. Embodiments may therefore employ a simple and/or cheap arrangement for enabling the support platform(s) to maintain a constant orientation

Embodiments may be adapted to restrict or prevent gerbiling when the acceleration or deceleration of the transportation device does not exceed a predetermined threshold value. In this way, embodiments may prevent the drive arrangement from being free to undergo gerbiling at all times. Instead, embodiments may be adapted such that only acceleration or deceleration of the wheel or device exceeding a certain threshold amount results in gerbiling of the drive arrangement. For such a purpose, a braking or movement-limiting arrangement may be employed. This may help to improve the stability, safety and/or usability of the device.

An embodiment may be adapted to restrict gerbiling of the drive arrangement to within a predetermined allowable range of offset distances or angles from a rest position, wherein, in the rest position, the drive arrangement contacts the inner rim at the lowermost portion of the inner rim. For example, to restrict gerbiling to within an allowable amount, the drive arrangement may adapted to contact the inner rim at two or more differing points when at an end of the allowable range of offset distances or angles. For instance, the drive arrangement may comprise a stopper or brake that is adapted to restrict further gerbiling movement by contacting (e.g. bearing against) a part of the wheel or device.

Embodiments may further comprising an actuation arrangement that is adapt to permit or prevent gerbiling of the drive arrangement, and the actuation arrangement may, for example, in response to an activation signal, and the activation signal may be based on one or more operating characteristics of the unicycle.

The load for transportation may comprise a package. Embodiments may therefore provide a powered transportation device for transporting package or items of stock in an automated manner.

Alternatively, the load for transportation may comprise a person. Embodiments may therefore provide a powered transportation device for transporting a person or individual.

The transportation device may be a self-balancing unicycle device having a single primary wheel adapted to be driven by said motor. Embodiments may therefore provide a powered self-balancing unicycle device that employs a smaller, lighter and/or cheaper motor than conventional devices. Further, in an embodiment, the single primary wheel may be hubless and the device may further comprise a drive wheel adapted to be rotated by a motor and to contact the inner rim of the hubless wheel.

In another embodiment, the transportation device may comprise a pair of wheels. Also, the support platform may be positioned between the pair of wheels. For example, embodiments may include powered self-balancing twowheeled transportation devices having a support platform situated between the two wheels (so that the user is intended to stand between the two-wheels for example). In such embodiments, there may be provided a single support platform for supporting the user or load (between the wheels), and a control system may be provided which is adapted to permit gerbiling of the drive arrangement and further adapted to control the degree of gerbiling of the drive arrangement.

Embodiments may therefore be adapted to cater for various configurations of support platforms, such as: single support platforms that extend through the unicycle device so as to protrude from either side; or separate support platforms (provided for each foot of a user, for example) situated on opposite sides of the device.

Embodiments may also help improve device safety by reducing (e.g. damping) the effect of hitting a sudden bump or obstacle, etc. For example, a sudden deceleration of the device may not be mirrored by the support platform(s). Instead, relative movement of the support platform(s) to the chassis of the device may mean that the load for transportation experiences less or more gradual deceleration.

For the avoidance of doubt, reference to a single, primary wheel should be taken to mean the generally circular unit that is adapted to rotate about an axis to propel the device in a direction during use. The single wheel may therefore be formed from one or more tyres and/or hubs that are coupled together (via a differential, for example). For example, an embodiment may comprise a single hubless wheel having a single hubless rim with a plurality of separate tyres fitted thereon. Alternatively, an embodiment may comprise a single hubless wheel formed from a plurality of hubless rims (each having a respective tyre fitted thereon), wherein the plurality of hubless rims are coupled together via a differential bearing arrangement.

Embodiments may provide a powered transportation device having a hubless wheel and adapted to permit gerbiling of a drive arrangement for the hubless wheel in a controlled manner. Such control of gerbiling may enable controlled alteration of the centre of gravity of the device. The centre of gravity may therefore be adjusted in a manner which helps to overcome a bump or obstacle for example.

Brief description of the drawings

An example of the invention will now be described with reference to the accompanying diagrams, in which: FIG. 1 is an isometric view of an embodiment of a powered unicycle device in a closed configuration; FIG. 2 is an exploded diagram of components internal to the casing of FIG. 1, FIGS. 3A & 3B are side and front elevations, respectively, of the embodiment of FIG. 1, wherein the casing is moving between a closed and open configuration; FIGS. 4A & 4B are side and front elevations, respectively, of the embodiment of FIG. 1, wherein the casing is in an open configuration and the foot platforms are in a stowed configuration; FIGS. 5A & 5B are side and front elevations, respectively, of the embodiment of FIG. 1, wherein the casing is in an open configuration and the foot platforms are in an active configuration; FIG. 6 is an isometric view of the embodiment of FIG. 1, wherein the casing is in an open configuration and the foot platforms are in an active configuration; FIG. 7 is a schematic side view of the embodiment of FIGS. 1-6, wherein the drive arrangement undergoes gerbiling; FIG. 8 is a schematic side view of another embodiment of a powered unicycle device, wherein the unicycle device is depicted when the drive arrangement undergoes gerbiling; and FIG. 9 depicts a modification to the embodiment of FIG. 9.

Detailed description

Proposed is a powered transportation device employing a hubless wheel and adapted to permit gerbiling of a drive arrangement for the hubless wheel in a controlled manner. By allowing gerbiling (which is normally arranged to be prevented in conventional devices) whilst also controlling its degree, embodiments may alter the centre of gravity of the device, and such alteration of the centre of gravity may be controlled. Such movement of the centre of gravity may help, for example, towards propelling and/or lifting the device over an obstacle and thus reduce an amount of torque/power required of the drive arrangement.

The proposed concept(s) may thus be employed in various types of powered transportation devices that employed at least one hubless wheel driven by a drive arrangement situated in the void defined by the inner rim of the hubless wheel. For instance, embodiments may provide a self-balancing transportation device having one, two, or more wheels. Further, such selfbalancing transportation devices may be adapted to be automated (e.g. for transporting package or items in an automated manner).

The term vertical, as used herein, means substantially orthogonal to the generally horizontal ground surface upon which a transportation device may travel. The term lateral, as used herein, means substantially parallel to the generally horizontal ground surface. Also, terms describing positioning or location (such as above, below, top, bottom, etc.) are to be construed in conjunction with the orientation of the structures illustrated in the diagrams.

The diagrams are purely schematic and it should therefore be understood that the dimensions of features are not drawn to scale. Accordingly, the illustrated thickness of any of the components or features should not be taken as limiting. For example, a first component drawn as being thicker than a second component may, in practice, be thinner than the second component. FIGS. 1-6 show one embodiment of a powered unicycle device 100. FIG. 1 shows the powered unicycle device 100 with a casing 110 in a closed configuration so that it encases a single wheel 120. Here, the casing 110 is formed from a first, upper portion 110A that covers the top (uppermost) half of the wheel 120, and a second, lower portion 11 OB that covers the bottom (lowermost) half of the wheel 120. FIG 2 illustrates an exploded view of components internal to the casing 110, namely a wheel 120 and drive arrangement 135.

Referring back to FIG. 1, the wheel 120 spins about a central axis 125. The first, upper portion 110A of the casing is retained in a fixed position relative to the central axis 125, whereas the second, lower portion 11 OB of the casing is adapted to rotate about the central axis 125. Rotation of the second lower portion 11 OB about the central axis 125 moves the casing between closed and open configurations (as illustrated by FIGS. 3-4). In the closed configuration (shown in FIG. 1), the casing 110 encloses the wheel 120 so that the outer rim 130 of the wheel 120 is not exposed. In the open configuration (shown in FIG. 5), the outer rim 130 of the wheel 120 is exposed so that it can contact a ground surface.

Referring now to FIG. 2, rotation of the single wheel 120 is driven by a drive arrangement 135 according to an embodiment. The drive arrangement 135 includes guide wheels 140 attached to an outwardly facing side of respective batteries 145. In this embodiment, there are two pairs of angled guide wheels 140, wherein the two guide wheels in each pair share are tapered or conical such that they have a sloped surface which is not perpendicular to the radial plane of the single wheel 120. Put another way, the contact surface of each guide wheel is inclined with respect to the radial plane of the single wheel 120. The guide wheels 140 of each pair are also positioned spaced apart to provide a gap between the two guide wheels of a pair. A rib 150 is provided around the inner rim of the wheel 120 and fits into the gap between the two guide wheels 140 in each pair. The guide wheels 140 are therefore adapted to contact with the inner rim of wheel 120 where they spin along with wheel 120 and hold wheel 120 in place by way of the rib 150. Of course, it will be appreciated that other arrangements, including those with only one guide wheel per battery 145, are possible.

The batteries 145 are mounted on a motor 155 which drives a pair of drive wheels 160 positioned at the lowermost point along the inner rim of the wheel 120. The batteries 145 supply power to motor 155 and, this embodiment, there are two batteries in order to create a balanced distribution of volume and weight. However, it is not necessary to employ two batteries 145. Also, alternative energy storage arrangements may be used, such as a flywheel, capacitors, and other known power storage devices, for example.

The drive wheel 160 is adapted to contact the inner rim of the wheel 120. The drive wheel 160 for example comprises a wide roller with a groove in the center into which the rib 150 fits. By way of contact with the inner rim of the wheel 120, the drive wheel 160 transmits torque from the motor 155 to the wheel 120. It will be understood that this drive system operates by friction and it may be preferable to avoid slippage between the drive wheel 160 and the inner rim of wheel 120. Positioning the drive wheel 160 at the lowermost point enables the weight of a user to provide a force which presses the drive wheel 160 against the inner rim of the wheel 120, thereby helping to reduce or avoid slippage.

Referring to FIGS. 5-6, two foot platforms 165 are coupled to the drive arrangement 135, with one on each side of wheel 120.

In the open configuration, the foot platforms 165 are movable between a stowed configuration, wherein the foot platforms are substantially parallel with the plane of the wheel (as shown in FIG. 4), and an active configuration, wherein the foot platforms are substantially perpendicular to the plane of the wheel (as shown in FIGS. 5-6) so as to support a user’s weight. Thus, in this embodiment, the foot platforms 165 are movable between: (i) a stowed configuration wherein they are flat against the side of the wheel and can be rotated (with the second, lower portion 11 OB of the casing) about the central axis 125 so as to be positioned inside (and covered by) the first, upper portion 110A of the casing; and (ii) an active configuration, wherein they project outwardly from the side of the wheel to provide a support surface for the feet of a user (as shown in FIG. 5). Accordingly, the foot platforms 165 are upwardly foldable into a stowed configuration that narrows the profile of the unicycle 100 to aid in storage and carrying. In use, the foot platforms are moved to the active configuration, and the user stands with one foot on each platform 165.

The drive arrangement 135 includes a gyroscope or accelerometer system 170 which it senses forward and backward tilt of the device in relation to the ground surface and regulates the motor 155 accordingly to keep the device upright. This enables the unicycle to self-regulate its balance in the fore-and-aft plane.

When not in use, the foot platforms 165 are moved to the stowed configuration and then rotated (with the second, lower portion 11 OB of the casing) about the central axis 125 so as to move the casing to the closed configuration. Thus, in the closed configuration, the foot platforms 165 are stored inside the casing (covered by the first, upper portion 110A of the casing).

The example shown also comprises a lifting handle 180 coupled to the drive arrangement 135 via a plurality of rods 185. The lifting handle 180 is positioned at the top of the casing 110, above the wheel 120, and may be used to hold the unicycle 100 above the ground, for example to enable a user to lift, carry, convey or place the unicycle 100. A retractable carrying strap 190 is also provided and attached to the top of the casing 100. The carrying strap 190 may be used to carry the unicycle 100, for example over the shoulder of user. A hook may be provided on the bottom of the case to create rucksack-like belts from the carrying strap 190.

The embodiment of FIGS. 1-6 further comprises an actuator arrangement coupled to the foot platforms 165 and adapted to move the foot platforms between the stowed configuration and active configuration. The actuator arrangement comprises first and second telescoping actuators 195 adapted to move between an extended and retracted configuration so as to move the foot platforms 165 between the stowed position and active position. In FIG. 5, the telescoping actuators 195 are shown in its extended configuration.

Flere, the telescoping actuators 195 each comprise a telescopic cylinder formed from a plurality of nesting, telescoping sections that are adapted to extend and retract like sleeves, one inside another, so as to move between the extended and retracted configuration.

Although the above embodiment has been described as employing telescoping actuators which are formed from a plurality of nesting, telescoping sections that are adapted to extend and retract like sleeves, it will be understood that other embodiments may employ other types of telescoping actuators. For example, other embodiments may employ telescoping actuators which use actuating members that act as rigid linear shafts when extended, but break that line by folding, separating into pieces and/or uncoiling when retracted. Examples of such an alternative telescoping actuator include: a helical band actuator; a rigid belt actuator; a rigid chain actuator; and a segmented spindle.

The embodiment of FIGS. 1-6, also comprises a control system integrated with the gyroscope or accelerometer system 170. The control system a control system is adapted to permit gerbiling of the drive arrangement 135 and further adapted to control the degree of gerbiling of the drive arrangement 135. Thus, the drive arrangement of FIGS. 1-6 is permitted to undergo gerbiling and, as a result of such gerbiling, the centre of gravity of the device may be altered. Movement of the centre of gravity may help, for example. towards propelling and/or lifting the unicycle device over an obstacle and thus reduce an amount of torque/power required of the drive arrangement 135 that would otherwise be required. Furthermore, reduction of required torque, for example, may enable a smaller, lighter and/or cheaper motor 155 to be employed, thus reducing the cost and/or weight of the unicycle device.

By way of example, gerbiling of the drive arrangement 135 may be permitted when the wheel 120 rapidly or suddenly accelerates or decelerates, for example due to the wheel(s) hitting a small bump or obstacle.

Referring now to FIG. 7, there is (schematically) depicted an instance of the embodiment of FIGS. 1-6 wherein the drive arrangement undergoes gerbiling (as indicated by the dashed lines and the arrows labeled “G”), and wherein the foot platform(s) are not shown (for improved clarity).

As the wheel 120 hits an obstacle, for example, it undergoes a sudden deceleration. However, the forward momentum of the supported user or load (not shown) overcomes the force of gravity keeping the drive wheel 160 at its normal/rest position at the bottom (i.e. lowermost) point of the inner rim of the wheel 120. This results in the drive arrangement undergoing gerbiling so that its spins around the inner rim of the wheel 120. In other words, the drive wheel 160 runs along the inner rim of the wheel so that the drive wheel 160 and the drive arrangement 135 is offset from the rest position by an angle or distance as depicted by the arrows labeled “G”. As a result of the gerbiling, the centre of gravity of the device moves from a rest position (as depicted by the dot labeled “C”) to a second position (as depicted by the dot labeled “ C’ ”) which is both horizontally and vertically offset from its rest position C.

The gerbiling movement of the drive arrangement 135 follows a generally circular (or arc-shaped) direction due to the shape of the inner rim of the wheel 120. Thus, linear momentum of the unicycle device in a forward direction may be transferred into a swinging-like movement of the centre of the gravity of the device when the device undergoes gerbiling. Thus, at least part of the forward running momentum of the unicycle device may be translated into swinging movement that has a vertical component. The vertical component of the swinging movement may act towards lifting the device and thus reduce an amount of torque/power required to overcome the bump or obstacle. In other words, the vertical component of the gerbiling movement “G” of the drive arrangement may reduce the effective weight of the unicycle device, thus reducing or alleviating the power or torque required from the drive arrangement that would otherwise be required to overcome the obstacle. Further, alteration of the position of the centre of gravity may help, for example, to slightly destabilise the device in a forward direction thus helping towards propelling and/or lifting the device over an obstacle.

Although gerbiling of the drive arrangement 135 may be permitted in the embodiment of FIGS. 1-6, the control system may be adapted to restrict gerbiling of the drive arrangement 135 to within a predetermined allowable range R of offset distances or angles from a rest position. For instance, the allowable range of gerbiling may be represented by the long dash-dot-dotted lines labelled “R” in FIG. 7. The range of allowable gerbiling angles (wherein the rest position is defined as being at 0°) may, for example, extend between -45° and +45°. In other embodiments, the range of allowable gerbiling angles may be between -90° and +90°. It will be understood that other suitable ranges of allowable gerbiling may be defined, and these may include: -60° to +60°; -30° to +30°.

Also, it may be preferable to arrange the allowable range of gerbiling to not be symmetrical about the rest position (in other words, asymmetrical about 0°). For example, embodiments may be adapted to only permit forward gerbiling of the drive arrangement such that gerbiling is only permitted in the forward running direction of the device. Other embodiments may be adapted to permit forward gerbiling to a greater extent than backward gerbiling.

Also, it will be appreciated that a gerbiling angle beyond -90° or +90° may not be preferable because the circular shape of the inner rim would result in the lateral offset of the centre reducing from a maximum value that would occur when the gerbiling angle equals 90°.

For example, to restrict gerbiling to within an allowable amount, the drive arrangement may adapted to contact the inner rim at two or more differing points when at an end of the allowable range of offset distances or angles. For instance, the drive arrangement may comprise a stopper or brake arrangement that is adapted to restrict further gerbiling movement by contacting (e.g. bearing against) a part of the wheel or device. In other examples, the control system may be adapted to control rotation/driving of the drive wheel (e.g. based on one or more signals from the gyroscope or accelerometer system 170) so as to prevent further gerbiling beyond a predetermined offset or angle.

Turning now to FIG. 8, there is depicted a schematic diagram of another embodiment of a self-balancing powered unicycle 800. Like conventional selfbalancing powered unicycles, the embodiment of FIG.9 comprises: a drive arrangement 135 position inside the void of a hubless wheel 120 and adapted to drive rotation of the wheel 120 using a motorized drive wheel 160 that presses against the inner rim of the wheel 120. A balance control system (not visible) is adapted to maintain fore-aft balance of the unicycle 800 by controlling rotation of the wheel 120 (via the drive arrangement 135 for example). First and second platforms 165 are provided proximate to either side of the wheel 120 for supporting a user of the unicycle 800. However, unlike conventional self-balancing powered unicycles, the foot platforms 165 are coupled to the drive arrangement 135 such that the foot platforms 165 can move relative to the drive arrangement 135 in response to (controlled) gerbiling of the drive arrangement 135.

Here, the embodiment of FIG. 8 comprises an orientation arrangement adapted to maintain the support platform in a substantially constant orientation when the drive arrangement 135 undergoes gerbiling. More specifically, the embodiment of FIG. 8 is adapted to maintain an upper (user/load-supporting) surface of the support platform(s) 165 in a substantially horizontal configuration so that the support platform 165 does not tilt when the drive arrangement undergoes gerbiling. This may help to prevent the load from losing its balance, and may therefore improve the safety and/or usability of the device.

In this example, the support platform orientation arrangement of FIG. 8 comprises a rotatable mount upon which the support platform(s) 165 is/are supported so that the support platform(s) 165 can to rotate relative to the drive arrangement 135. FIG. 8 depicts the unicycle 800 at the moment that the drive arrangement 135 has undergone a permitted amount of gerbiling in a forward direction. The forward gerbiling of the drive arrangement 135 has resulted in the drive arrangement being tilted from its normal resting position. This rotational movement of the drive arrangement is guided by the drive wheel 160 travelling along the inner rim of the wheel 120 so that it is offset from the lowermost point of the inner rim (as depicted in FIG. 8). This rotational movement of the drive arrangement would normally result in equivalent rotational movement of the foot platform(s) 165 if the coupling arrangement was not adapted to allow the foot platform(s) to rotate relative to the drive arrangement 135. However, by rotating the foot platform(s) relative to the drive arrangement 135 (as depicted by the arrows labeled “F”) so as to compensate the rotation of the drive arrangement, the foot platforms 165 are maintained in a substantially horizontal configuration.

By maintaining the upper (user/load-supporting) surface of the foot platforms 165 in a substantially horizontal configuration when the drive arrangement undergoes gerbiling, the user/load-supporting-surface of the foot platform(s) 165 does not tilt relative to a ground/supporting surface upon which the device travels, for example. This may help to prevent the user/load from losing balance, and thus improve the safety and/or usability of the device.

Movement of the support platform(s) 165 relative to the drive arrangement 135 may not only be used to maintain an orientation of the foot platform(s), but alternatively (or additionally) movement of the support platform(s) 165 relative to the drive arrangement 135 may be used to alter or manipulate the centre of gravity of the device. Manipulation of the entre of gravity may, for example, help to stabilize the device, dampen sudden movements experienced by the load/user, and/or pull the device forwards and upwards over an obstacle (e.g. a curb).

For instance, turning now to FIG. 9, there is illustrated a modification to the embodiment of FIG. 8. More specifically, the embodiment of FIG. 9 is similar to that of FIG. 8, except that the coupling arrangement is adapted to slide the support platform(s) 165 relative to the drive arrangement 135 in response to gerbiling of the drive arrangement, so as to alter the centre of gravity of the device for example. FIG. 9 depicts the unicycle 900 at the moment that the drive arrangement 135 has undergone a permitted amount of gerbiling in a forward direction. The forward gerbiling of the drive arrangement 135 has resulted in the drive arrangement being tilted from its normal resting position. This rotational movement of the drive arrangement is guided by the drive wheel 160 travelling along the inner rim of the wheel 120 so that it is offset by Θ from the lowermost point of the inner rim (as depicted in FIG. 9). This rotational movement of the drive arrangement 135 would normally result in the centre of gravity of the device moving from a rest position to a first modified position (as depicted by the circle labelled “C”) if the coupling arrangement was not adapted to allow the foot platform(s) 165 to slide relative to the drive arrangement 135. Flowever, by sliding the foot platform(s) relative to the drive arrangement 135 (as depicted by the arrows labeled “S”) so as to compensate the rotation of the drive arrangement 135, the centre of gravity can be moved to a second position (as depicted by the dot labelled “ C’ ”) which is both horizontally offset from the first position C.

More specifically, in the example of FIG. 9, the coupling arrangement is adapted to slide the foot platform(s) relative to the drive arrangement 135 (as depicted by the arrows labelled “S”) so that the resulting position C’ of the centre of gravity is vertically aligned with the centre of gravity of the wheel 120. In other words, the sliding of the foot platform(s) is adapted to maintain the centre of gravity in a position C’ that is not laterally offset from the centre of the wheel 120.

By maintaining the centre of gravity vertically in line with the centre of the wheel, and thus vertically above the lowermost point of the wheel (which contact the ground/supporting surface for example), the stability of the device may be maintained while the drive arrangement undergoes gerbiling. This may help to prevent the user/load from losing balance, and thus improve the safety and/or usability of the device, for example.

It will be appreciated that variations of the embodiments described above may employ other arrangements and/or mechanisms.

For instance, embodiments may comprise an actuation arrangement adapted to permit or prevent gerbiling of the drive arrangement under the control of an activation signal. Such an actuation system may, for example, be part of (or provided by) the control system that is adapted to permit gerbiling and to control its extent.

For example, the activation signal may be based on one or more operating characteristics of the transportation device, such as speed, acceleration, torque, deceleration, power, etc. For instance, an algorithm may be adapted to determine if signals from the drive arrangement and/or the balance control system exhibit a predetermined characteristic. The signals from the drive arrangement and/or the balance control system may comprise information relating to at least one of: casing orientation; inclination or angle of a part of the transportation device; value of compressive force applied to at least part of a support platform; accelerometer data; gyroscope data; motor torque; speed of wheel rotation; and a motor drive voltage.

Alternatively, or additionally, transportation device may comprise an entity presence detection system adapted to detect the presence of an entity on, at or near a part of, the transportation device, and the activation signal may then be based on a signal from the entity presence detection system. Thus, an embodiment may provide an indication or signal which is used by the control system to permit, prevent or alter gerbiling of the drive arrangement upon occurrence of one or more predetermined conditions indicating an entity (such as a user) is present or not-present on (or near) the transportation device. Such embodiments may, for example, control gerbiling of the drive arrangement when a user or load alights or loses contact with the support platform(s). Embodiments may therefore enable the control system to automatically stop or maintain a degree of gerbiling if a user alights or dismounts from the device (e.g. by intentionally stepping/jumping off the support platform(s)).

The entity presence detection system may comprise a load sensing system adapted to determine a loading applied to at least one part of the powered unicycle. Further, the load sensing system may be adapted to determine at least one of: a deflection of the wheel axel; a compressive force applied to the wheel axel; a deflection of the support platform(s); a tensile force applied to the support platform(s); and a compressive force applied to the support platform(s), so as determine a loading applied to the support platform(s) of the transportation device. In such embodiments, operation of the control system may be based on a value of the loading applied to one or more parts of the transportation device. In some embodiments, the entity presence detection system may comprise a processing unit adapted to process signals in accordance with an algorithm to determine if an entity is present on, at or near a part of the transportation device. By way of example, such an algorithm may be adapted to determine if the signals from the drive arrangement and/or the balance control system exhibit a predetermined characteristic indicating the presence or non-presence of a user/load on the transportation device. The signals from the drive arrangement and/or the balance control system may comprise information relating to at least one of: casing orientation; inclination or angle of a part of the transportation device; value of compressive force applied to at least part of a support platform; accelerometer data; gyroscope data; motor torque; speed of wheel rotation; and a motor drive voltage.

For instance, embodiments may be adapted to restrict or prevent gerbiling when the acceleration or deceleration of the transportation device does not exceed a predetermined threshold value. In this way, embodiments may prevent the drive arrangement from being free to undergo gerbiling at all times. Instead, embodiments may be adapted such that only acceleration or deceleration of the wheel or device exceeding a certain threshold amount results in gerbiling of the drive arrangement. For such a purpose, a braking or movement-limiting arrangement may be employed. This may help to improve the stability, safety and/or usability of the device.

According to yet another embodiment, the entity presence detection system may comprise a vibration sensor adapted to detect a frequency of vibration of at least one part of the powered unicycle. The entity presence detection system may be adapted to determine the presence or non-presence of a user based on if a detected frequency of vibration of at least one part of the powered unicycle is within a predetermined range.

Embodiments may be employed in a self-balancing powered transportation device to alleviate power or torque requirements on the drive arrangement. Such reduction of required torque, for example, may enable a smaller, lighter and/or cheaper motor to be employed, thus reducing the cost and/or weight of the device. It may also improve device safety by reducing (e.g. damping) the effect of hitting a sudden bump, obstacle, etc. and/or improving stability of the device.

It is noted that the embodiments described above include two (e.g. left and right foot) support platforms. It is to be understood that proposed embodiments need not be restricted to being employed with two support platforms, but may instead be employed in embodiment with only a single support platform. Also, while specific embodiments have been described with reference to a powered self-balancing unicycles having one or more foot platforms, it is to be understood that embodiments need not be restricted to powered self-balancing unicycles, but may instead be employed in selfbalancing transportation devices having more than one wheel and/or a supporting platform for supporting a user (such as a seat for example). By way of example, embodiments may include powered self-balancing twowheeled transportation devices having a support platform situated between the two wheels (so that the user is intended to stand or sit between the two-wheels for example). In such embodiments, there may be provided a single support platform for supporting the user (between the wheels).

Also, the load for transportation may comprise a package rather than a person or human. Embodiments may therefore provide a powered transportation device for transporting package or items of stock in an automated manner for example.

Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

Accordingly, while specific embodiments have been described herein for purposes of illustration, various modifications will be apparent to a person skilled in the art and may be made without departing from the scope of the invention.

Claims

1. A powered transportation device comprising: a hubless wheel having an inner rim; a drive arrangement positioned inside the void defined by the inner rim of the hubless wheel and adapted to drive rotation of the hubless wheel; at least one support platform for supporting a load for transportation; and a control system adapted to permit gerbiling of the drive arrangement and further adapted to control the degree of gerbiling of the drive arrangement.

2. The device of claim 1, further comprising a coupling arrangement adapted to couple the support platform to the drive arrangement and further adapted to allow the support platform to move relative to the drive arrangement in response to gerbiling of the drive arrangement.

3. The device of claim 2, wherein the coupling arrangement is adapted to slide the support platform relative to the drive arrangement in response to gerbiling of the drive arrangement so as to alter the centre of gravity of the device.

4. The device of claim 2 or 3 wherein the coupling arrangement is adapted to move the support platform relative to the drive arrangement in response to gerbiling of the drive arrangement so as to vertically align the centre of gravity of the device with a predetermined reference position of the device

5. The device of claim 2, 3 or 4, wherein the coupling arrangement is further adapted to maintain the support platform in a substantially constant orientation when the drive arrangement undergoes gerbiling.

6. The device of claim 5, wherein the coupling arrangement comprises a rotatable mount upon which the support platform is supported such that the support platform is adapted to rotate relative to the drive arrangement.

7. The device of any preceding claim, wherein the transportation device is adapted to restrict gerbiling of the drive arrangement to within a predetermined allowable range of offset distances or angles from a rest position, wherein, in the rest position, the drive arrangement contacts the inner rim at the lowermost portion of the inner rim.

8. The device of claim 7, wherein the drive arrangement is adapted to contact the inner rim at two or more differing points when at an end of the allowable range of offset distances or angles.

9. The device of any preceding claim, further comprising a braking arrangement adapted to restrict or prevent gerbiling of the drive arrangement if the acceleration or deceleration of the transportation device is less than a predetermined threshold value.

10. The device of any preceding claim, further comprising an actuation arrangement adapted to permit or prevent gerbiling of the drive arrangement under the control of an activation signal.

11. The device of claim 10, wherein the activation signal is based on at least one of: one or more operating characteristics of the transportation device; and a signal from an entity presence detection system adapted to detect the presence of an entity on, at or near a part of, the transportation device.

12. The device of any preceding claim, wherein the load for transportation comprises a person.

13. The device of any of claims 1 to 11, wherein the load for transportation comprises a package or item for delivery and wherein the drive arrangement is adapted for automated control.

14. The device of any preceding claim, wherein transportation device is a self-balancing unicycle device comprising: a single primary hubless wheel adapted to be driven by said drive arrangement; and a balance control system adapted to maintain fore-aft balance of the unicycle device.

15. The device of claim 14, wherein the drive arrangement comprises a drive wheel adapted to be rotated by a motor and to contact the inner rim of the single primary hubless wheel.

16. The device of any of claims 1 to 13, wherein the self-balancing transportation device comprises a pair of wheels.

17. A powered transportation device substantially as herein described above with reference to the accompanying figures.