GB2536740A

GB2536740A - A mobile chassis and a wheelchair using the same

Info

Publication number: GB2536740A
Application number: GB1514029.6A
Authority: GB
Inventors: Hainsworth Richard; Lok Wu King
Original assignee: Single Person Transp Design (sptd) Ltd
Current assignee: Single Person Transp Design (sptd) Ltd
Priority date: 2015-03-25
Filing date: 2015-08-07
Publication date: 2016-09-28
Anticipated expiration: 2035-08-07
Also published as: HK1200641A2; GB2536740B; TWM527319U; GB201514029D0; WO2016150299A1

Abstract

A self-balancing mobile chassis with a frame 210 for supporting a load carried by the chassis, a motor assembly for providing a driving force to move the chassis via a plurality of wheels 230/235, the motor assembly connected to the frame. One or more actuators 260a connect the frame and the motor assembly via first and second ends respectively, the lengths between the ends being controllable such that when the wheels are deployed the frame is lifted to suspend from the surface on which the chassis rests, causing the chassis to be self-balanced by the wheels, and when the wheels are not deployed they are suspended from or on the surface so that the frame at least partially supports the chassis, which is held stationary. A wheelchair which comprises a seat mounted on the chassis, as well as a shell for covering the chassis is also disclosed.

Description

A Mobile Chassis and a Wheelchair using the Same

FIELD OF THE INVENTION

100011 The present invention relates to a wheeled mobile chassis, and a wheelchair that uses the chassis where the wheelchair is usable for a physically challenged person.

BACKGROUND

[0002] For physically challenged people who are required to frequently use wheelchairs, increasing mobility for these people enhances their employability, living standards and social interaction. However, traditional powered wheelchairs are large, heavy, clunky in appearance, and badly adapted to work environment. There is a need in the art to have a wheelchair that is small in size, light-weight and agile with high mobility.

SUMMARY OF THE INVENTION

[0003] In the present invention, a multi-wheel mobile chassis with vertical extendibility is provided. A mobile transportation device in the form of a wheelchair is realizable by including the disclosed chassis.

[0004] The chassis comprises a frame configured to support a load carried by the chassis, and a motor assembly for providing driving force to move the chassis. The frame comprises a plurality of legs for supporting the frame when the frame rests on a flat surface. The motor assembly is connected to the frame, and comprises a first wheel and a second wheel both of which are independently driven such that collaborative motions of the first wheel and of the second wheel at least enable the chassis to be rotatable as well as to be linearly movable. The chassis further includes one or more actuators collectively having a first end and a second end. The one or more actuators are configured to vary a length between the first end and the second end in order to adjust a vertical distance between the frame and the two wheels. In particular, the following two results are achieved by varying the aforementioned length when the chassis is on the fiat surface. When the chassis is deployed to be movable, the two wheels are caused to touch the Rat surface so as to lift up the frame without the plurality of legs touching the flat surface, causing the chassis to be self-balanced by maneuvering the first and second wheels. When the chassis is not deployed to be movable, the two wheels are caused Page 1 to be positioned above or on the flat surface so that the plurality of legs at least partially supports the chassis, which is thereby held stationary.

190051 In one embodiment, the motor assembly further comprises a first motor for driving the first wheel, a second motor for driving the second wheel, and a motor assembly arm having plural arm ends each rotatably connected to the frame to thereby connect the motor assembly thereto. In particular, the first motor and the second motor are independently controllable in driving the first wheel and the second wheel to generate the collaborative motions. Furthermore, the first motor and the second motor are affixed to the motor assembly arm such that rotational axes of the first wheel and of the second wheel are substantially aligned.

190061 Desirably, one or more sensors are included in the chassis for measuring orientation and acceleration of the chassis. Measurement results obtained from the one or more sensors arc utilizable to control the collaborative motions of the two wheels so as to achieve self-balancing of the chassis.

190071 By using the disclosed chassis, a wheelchair is realizable by further including a shell covering for covering the chassis to provide an external aesthetic look to the wheelchair, and a scat mounted on the chassis for a user to sit on.

190081 Other aspects of the present invention are disclosed as illustrated by the embodiments hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

190091 FIGS. 1A and 1B depict a perspective view and a bottom view, respectively, of a wheelchair in accordance with one embodiment of the present invention.

190101 FIGS. 2A-2D depict, in accordance with an exemplary embodiment of the present invention, a bi-wheel self-balancing mobile chassis when the chassis is deployed to be movable with two wheels lowered down to touch a flat surface, where FIGS. 2A, 2B, 2C and 2D show a side view, a front view, a top view and a perspective view, respectively, of the chassis.

190111 FIGS. 3A-3D depict the chassis when the chassis is not deployed to be movable so that the two wheels are elevated above or on the flat surface, where FIGS. 3A, 3B, 3C and 3D show a side view, a front view, a top view and a perspective view, respectively, of the chassis.

Page 2

DETAILED DESCRIPTION OF THE INVENTION

100121 To reduce the weigh( and the size of a wheelchair while increasing its maneuverability, the inventors have observed that a two-wheel self-balancing personal transporter is usable in the design of such wheelchair Examples of the personal transporter can be found in CN203186511U, CN203958471U and US7958961B1, for instance. Since a personal transporter uses only two wheels, the transporter has the potential to be light-weigh( and compact in size. By independently maneuvering the two wheels, it is easy to drive the transporter to linearly move forward and backward as well as to rotate. Despite various advantages of the personal transporter, direct adoption of the personal transporter to a wheelchair has shortcomings Since the wheelchair is normally used by a physically challenged user, using only two wheels to support the wheelchair gives rise to a stability problem, posing a risk to the user. If stability of the wheelchair is to be ensured, continuous execution of a self-balancing process is required at the expense of high power consumption, necessitating increasing the weight of a battery pack to be installed in the wheelchair and thus defeating a goal of keeping a light weight. Inventive modification of the personal transporter to develop the wheelchair disclosed herein is detailed hereinafter.

100131 An aspect of the present invention is to provide a hi-wheel self-balancing mobile chassis. Based on the disclosed chassis, a mobile transportation device in the form of a wheelchair is realizable. Although one application of the chassis is to develop the wheelchair usable by a physically challenged user, it is not intended that the chassis disclosed herein is limited only to building such wheelchair The chassis is also usable to construct other mobile transportation devices that require light weight, small size and high maneuverability.

100141 FIGS. 1A and 1B depict a wheelchair in accordance with an embodiment of the present invention, where FIG. 1A is a perspective view and FIG. 1B is a bottom view. A wheelchair 100 employs an inventive mobile chassis 110, enclosed inside a shell covering 130, for driving the wheelchair 100 to move as well as to rotate and to change movement direction. Specifically, the chassis 110 uses only two wheels and includes a self-balancing mechanism for maintaining balance of the wheelchair 100. The shdl covering 130 is used for covering the chassis 110 to provide an external aesthetic look to the wheelchair 100. The shell covering 130 may be made of, for example, fiber glass, which has an advantage of light weight. In the wheelchair 100, a seat 140 is mounted on the chassis 110 for a user to sit on. The wheelchair 100 may be equipped with optional ancillary components, examples of which include the following: a joystick input device for the user to steer the wheelchair 100; Page 3 additional input devices for communicating steering information to the chassis 110 via wireless connectivity; and extra devices or additional parts attachable to the chassis 110 for providing support to parts of the body or limbs, for example arms, legs or head, of the user when the user has special requirements.

100151 The inventive mobile chassis 110 is exemplarily illustrated as follows with the aid of FIGS. 2A-2D and 3A-3D. The two sets of FIGS. 2A-2D and FIGS. 3A-3D depict a biwheel self-balancing mobile chassis 200: when the chassis 200 is deployed to be movable (FIGS. 2A-2D); and when the chassis 200 is not deployed to move itself (FIGS. 3A-3D). In these two sets of figures, side views of the chassis 200 are shown in FIGS. 2A and 3A, front views in FIGS. 2B and 3B, top views in FIGS. 2C and 3C, and perspective views in FIGS. 2D and 3D.

100161 For illustration, FIGS. 2A and 3A include a flat surface 510 (not part of the chassis 200) as a reference surface on which the chassis 200 rests during operation. A reference vertical direction 500 that is perpendicular to the flat surface 510 is obtained. Herein in the specification and appended claims, positional and directional words such as "above," "below," "rise up" and "lower down" are interpreted with reference to the reference vertical direction 500.

100171 The chassis 200 comprises a frame 210 configured to support a load carried by the chassis 200. For example, the load may be the seat 140 shown in FIG. 1A. The frame 210 comprises a plurality of legs 215a, 215b for supporting the frame 210 when the frame rests on the flat surface 510 (as shown in FIG. 3A). Although two legs 215a, 215b are shown in FIGS. 2D and 3D for illustration, the present invention is not limited to only two legs for the frame 210.

100181 The chassis 200 further comprises a motor assembly for providing driving force to move the chassis 200. The motor assembly is an assembly of motor(s), wheel(s) and other mechanical parts, e.g., power-transferring components, arranged such that the chassis 200 can be moved. The motor assembly comprises a plurality of wheels all of which revolve synchronously or independently of each other. Preferably and advantageously, the plurality of wheels consists of a first wheel 230 and a second wheel 235 both of which are independently driven such that collaborative motions of the first whed 230 and of the second wheel 235 at least enable the chassis 200 to be rotatable as well as to be fi nearly movable. The principle under which the two independently-driven wheels 230, 235 can realize rotation and linear motion of the chassis is similar to the operating principle of a personal transporter (for example, please see U57958961 BI). In one practical implementation of the chassis 200, Page 4 the motor assembly further comprises a first motor 240 for driving the first wheel 230, a second motor 245 for driving the second wheel 235, and a motor assembly arm 220. The first motor 240 and the second motor 245 are independently controllable in driving the first wheel 230 and the second wheel 235 to thereby generate the collaborative motions. In addition, the first motor 240 and the second motor 245 are affixed to the motor assembly arm 220 such that the first wheel 230's rotational axis 231 is substantially aligned with the second wheel 235's rotational axis 236. The motor assembly arm 220 has plural arm ends (one of the arm ends being referenced as 222). Each of the arm ends is rotatably connected to the frame 210 so that the motor assembly is also connected to the frame 210. In one embodiment, each of the arm ends (e.g., the arm end 222) is rotatably connected to the frame 210 via a hinge (e.g., a hinge 223). In another embodiment, the motor assembly arm 220 is a U-shaped tubing (as depicted in FIGS. 2D and 3D) and the number of the arm ends is two.

[00191 In addition, one or more actuators (e.g., actuators 260a, 260b) are arranged to connect the frame 210 and the motor assembly. Although FIGS. 2B and 3B show that two actuators 260a, 260b are used, the present invention is not limited to only two actuators. The one or more actuators collectively have a first end 262 and a second end 263, connected to the frame 210 and the motor assembly arm 220, respectively. In one embodiment, connections between the first end 262 and the frame 210 and between the second end 263 and the motor assembly arm 220 are via hinges and hence rotatable. The one or more actuators enable a length between the first end 262 and the second end 263 to be controllable. In one implementation, each actuator is capable of extending and contracting along such actuator's body, and the one or more actuators are arranged to synchronously extend and contract in one common direction so that the aforementioned length can be varied and made controllable. By varying the aforementioned length, the one or more actuators are configured to adjust a vertical distance between the frame 210 and the two wheels 230, 235 in order to achieve the following outcomes.

* When the chassis 200 is on the flat surface 510 and is deployed to be movable, the first wheel 230 and the second wheel 235 are caused to touch the flat surface 510 so as to lift up the frame 210 without the plurality of legs 215a, 215b touching the flat surface 510 (as shown in FIG. 2A). It causes the chassis 200 to self-balance itself by maneuvering the first wheel 230 and the second wheel 235.

Page 5 * When the chassis 200 is on the flat surface 510 and is not deployed to be movable, the first wheel 230 and the second wheel 235 are caused to be positioned above or on the flat surface 510 so that the plurality of legs 215a, 215b at least partially supports the chassis 200 (as shown in FIG. 3A, where the two wheels 230, 235 are positioned on the flat surface 510 as an example for illustration). Thereby, the chassis 200 is held stationary. In the special case that the two wheels 230, 235 are above the flat surface 510, the chassis 200 is entirely supported by the plurality of legs 215a, 215b.

100201 Since the chassis 200 is supported by the two wheels 230.235 when it is deployed to be movable, as is mentioned above, self-balancing by controlling the two wheels 230, 235 is required. To achieve self-balancing, the chassis 200 further comprises one or more sensors for measuring orientation and acceleration of the chassis 200. Examples of the one or more sensors include solid-state gyroscopes and accelerometers. Measurement results of the one or more sensors, after processing and analysis, are utilizable to control the collaborative motions of the two wheels 230, 235.

100211 Since it is desired that the chassis 200 is used to build a mobile transportation device in the form of a wheelchair, it is preferable that the first motor 240, the second motor 245 and the one or more actuators are electrically powered by one or more batteries.

100221 In one embodiment, the chassis 200 further comprises one or more electrical circuit boards that include one or more processors for controlling the first motor 240, the second motor 245 and the one or more actuators, and for processing the measurement results obtained by the one or more sensors. Optionally, the one or more electrical circuit boards further include one or more chips for providing wireless (e.g.. Bluetooth) connectivity.

100231 To hold the one or more electrical circuit boards, the chassis 200 may include a metal case 280 that is mounted to the frame 210. The metal case 280 can also be used to hold one or more batteries for powering various elements (such as the two motors 240,245 and the actuators 260a, 260b) in the chassis 200.

100241 As an example of manufacturing the chassis 200, the frame 210, the motor assembly arm 220, or both, are made of stainless steel tubing.

100251 Since the chassis 200 is used for carrying the load such as the seat 140, a means for securing the load on the chassis 200 is desirable and advantageous to be included in the chassis 200. In one embodiment, the frame 210 includes a plurality of posts 281a-d mounted thereon for matching to holes on the load to thereby securely fix the load on the frame 210.

Page 6 [0026] A prototype of the chassis 200 was built, and details thereof are provided as follows as a practical example for illustrating the realization of the chassis 200 disclosed herein. The frame 210 and the motor assembly arm 220 are made of stainless steel tubing of 25.4mm in diameter. The prototype uses two wheels (i.e. the first wheel 230 and the second wheel 235). Each of the two wheels 230, 235 is a solid rubber wheel of 307mm in diameter and 72mm in width, allowing the chassis 200 to rotate in a circle of about 70cm in diameter. As compared to a 150cm turning circle typical for a traditional electric wheelchair, the wheelchair 100 having the chassis 200 as disclosed above enjoys an advantage of elegantly saving space. The first motor 240 and the second motor 245 are direct-current motors. Motor axes of the first motor 240 and of the second motor 245 are directly attached to the first wheel 230 and the second wheel 235, respectively. The prototype uses two actuators (i.e. the actuators 260a, 260b). The actuators 260a, 260b are linear actuators, each of which has a contracted length of approximately 230 mm and an extended length of approximately 370 mm When the actuators 260a, 260b are in a contracted state, the two wheels 230, 235 do not touch the ground. When the actuators 260a, 260b are extended almost to the maximum, the two wheels 230,235 project some 150 mm below the plurality of legs 215a, 215b of the frame 210. The wheelchair 100 that incorporates the prototype as the chassis 110 has a significantly light weight of 40kg as compared to over 80kg for most of existing powered wheelchairs The inventors have also noticed a further advantage of the wheelchair 100. Since the self-balancing control implemented by the chassis 110 ensures that the seat 140 remains level, the user of the wheelchair 100 is automatically in an upright position even when the wheelchair 100 rides on a slope or is used on hills.

[0027] The embodiments disclosed herein may be implemented using general purpose or specialized computing devices, computer processors, or electronic circuitries including but not limited to digital signal processors (DSP), application specific integrated circuits (ASIC), field programmable gate arrays (FPGA), and other programmable logic devices configured or programmed according to the teachings of the present disclosure. Computer instructions or software codes running in the general purpose or specialized computing devices, computer processors, or programmable logic devices can readily be prepared by practitioners skilled in the software or electronic art based on the teachings of the present disclosure.

[0028] Although a hi-wheeled embodiment is described above, the present invention may be adapted to embodiments with any number of wheels. The present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative Page 7 and not restrictive. The scope oldie invention is indicated by the appended claims rather than by the foregoing description, and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Page 8

Claims

What is claimed is: 1. A mobile chassis, comprising: a frame for supporting a load carried by the chassis; a motor assembly for providing a driving force to move the chassis, wherein the motor assembly is connected to the frame, and comprises a plurality of wheels all of which revolve synchronously or independently of each other such that collaborative motions of the wheels at least enable the chassis to be rotatable as well as to be linearly movable; and one or more actuators collectively having a first. end and a second end, the first end and the second end being connected to the frame and the motor assembly, respectively, wherein a length between the first end and the second end is controllable by the one or more actuators such that: (a) when the chassis is on the flat surface and is deployed to be movable, the wheels are caused to touch the flat surface so as to lift up the frame to suspend from the flat surface, causing the chassis to be self-balanced by maneuvering the wheels; and (b) when the chassis is on the flat surface and is not deployed to be movable, the wheels are caused to be positioned suspending from or on the flat surface so that the frame at least partially supports the chassis, which is thereby held stationary.
2. The chassis of claim 1, wherein the plurality of wheels consists of a first wheel and a second wheel.
3. The chassis of claim 2, wherein the motor assembly further comprises: a first motor for driving the first wheel; a second motor for driving the second wheel, the first motor and the second motor being independently controllable in driving the first wheel and the second wheel to thereby generate the collaborative motions; and a motor assembly arm having plural arm ends each rotatably connected to the frame to thereby connect the motor assembly thereto, the first motor and the second motor being affixed to the motor assembly arm such that rotational axes of the first wheel and of the second wheel are substantially aligned.

Page 9
4. The chassis of claim 3, wherein each of the arm ends is rotatably connected to the frame via a hinge.
5. The chassis of claim 3 or claim 4, wherein the first end and the second end are rotatably connected to the frame and the motor assembly arm, respectively, via hinges.
6. The chassis of any one of claims 3 to 5, wherein the motor assembly arm is a U-shaped tubing and the number of the arm ends is two.
7. The chassis of any one of claims 3 to 6, wherein the motor assembly arm is made of stainless steel tubing.
8. The chassis of any one of claims 3 to 7, wherein the first motor, the second motor and the one or more actuators are electrically powered.
9. The chassis of any one of the preceding claim 1, further comprising: one or more sensors for measuring orientation and acceleration of the chassis, wherein measurement results of the one or more sensors are utilizable to control the collaborative motions of the wheels so as to achieve self-balancing of the chassis.
10. The chassis of claim 9, wherein the one or more sensors include one or more of solid-state gyroscopes and accelerometers.
11 The chassis of any one of claims 3 to 8, further comprising one or more electrical circuit boards that include one or more processors for controlling the first motor, the second motor and the one or more actuators, and for processing the measurement results.
12. The chassis of claim 11, further comprising a metal case, mounted to the frame, for containing one or more batteries, and the one or more electrical circuit boards.

Page 10
13. The chassis of claim 11 or claim 12, wherein the one or more electrical circuit hoards further include one or more chips for providing wireless connectivity.
14. The chassis of claim 13, wherein the one or more chips are configured to provide the wireless connectivity based on Bluetooth.
15. The chassis of any one of the preceding claims, wherein the frame further comprises a plurality of posts mounted thereon for matching to holes on the load to thereby securely fix the load onto the frame.
16. The chassis of any one of the preceding claims wherein the frame is made of stainless steel tubing.
17 A wheelchair for transporting a person, comprising: the chassis of any of the preceding claims; a shell covering for covering the chassis to thereby provide an external aesthetic look to the wheelchair; and a seat mounted on the chassis for the person to sit on.
18. The wheelchair of claim 17, further comprising a joystick input device for steering the wheelchair.
19. The wheelchair of claim 17 or claim 18, further comprising additional input devices for conununicating steering information to the chassis via wireless connectivity.
20. The wheelchair of any one of claims 17 to 19, further comprising additional parts attachable to the chassis for providing support to arms, legs, body or head of the person.
21. The wheelchair of any one of claims 17 to 20, wherein the shell covering is made of fiber glass.Page 11 Amendment to the claims have been filed as follows: 12 What is claimed is: 1 A mobile chassis, comprising: a frame for supporting a load carried by the chassis; a motor assembly for providing a driving force to move the chassis, wherein the motor assembly is connected to the frame, and comprises a plurality of wheels all of which revolve synchronously or independently of each other such that collaborative motions of the wheels at least enable the chassis to be rotatable as well as to be linearly movable; and one or more actuators collectively having a first end and a second end, the first end and the second end being connected to the frame and the motor assembly, respectively, wherein a length between the first end and the second end is controllable by the one or more actuators such that: (a) when the chassis is on a flat surface and is deployed to be movable, the wheels are caused to touch the flat surface so as to lift up the frame to suspend from the flat surface, causing the chassis to be self-balanced by maneuvering the wheels; and (b) when the chassis is on the flat surface and is not deployed to be movable, the wheels are caused to be positioned suspending from or on the flat surface so that the frame at least partially supports the chassis, which is thereby held stationary.2. The chassis of claim 1, wherein the plurality of wheels consists of a first wheel and a second wheel.3 The chassis of claim 2, wherein the motor assembly further comprises: a first motor for driving the first wheel; a second motor for driving the second wheel, the first motor and the second motor being independently controllable in driving the first wheel and the second wheel to thereby generate the collaborative motions; and a motor assembly arm having plural arm ends each rotatably connected to the frame to thereby connect the motor assembly thereto, the first motor and the second motor being affixed to the motor assembly arm such that rotational axes of the first wheel and of the second wheel are substantially aligned.4. The chassis of claim 3, wherein each of the arm ends is rotatably connected to the frame via a hinge The chassis of claim 3 or claim 4, wherein the first end and the second end are rotatably connected to the frame and the motor assembly arm, respectively, via hinges.6. The chassis of any one of claims 3 to 5, wherein the motor assembly arm is a U-shaped tubing and the number of the arm ends is two.7. The chassis of any one of claims 3 to 6, wherein the motor assembly arm is made of stainless steel tubing.8 The chassis of any one of claims 3 to 7, wherein the first motor, the second motor and the one or more actuators are electrically powered.o 9 The chassis of any one of the preceding claims, further comprising: one or more sensors for measuring orientation and acceleration of the chassis, wherein measurement results of the one or more sensors are utilizable to control the collaborative motions of the wheels so as to achieve self-balancing of the chassis 10. The chassis of claim 9, wherein the one or more sensors include one or more of solid-state gyroscopes and accelerometers 11. The chassis of any one of claims 3 to 8, further comprising one or more electrical circuit boards that include one or more processors for controlling the first motor, the second motor and the one or more actuators, and for processing the measurement results.12. The chassis of claim 11, further comprising a metal case, mounted to the frame, for containing one or more batteries, and the one or more electrical circuit boards.13. The chassis of claim 11 or claim 12, wherein the one or more electrical circuit boards further include one or more chips for providing wireless connectivity.14. The chassis of claim 13, wherein the one or more chips are configured to provide the wireless connectivity.15. The chassis of any one of the preceding claims, wherein the frame further comprises a plurality of posts mounted thereon for matching to holes on the load to thereby securely fix the load onto the frame.16. The chassis of any one of the preceding claims, wherein the frame is made of stainless steel tubing.17. A wheelchair for transporting a person, comprising: the chassis of any of the preceding claims; a shell covering for covering the chassis to thereby provide an external aesthetic look to the wheelchair, and a seat mounted on the chassis for the person to sit on. a)18. The wheelchair of claim 17, further comprising a joystick input device for steering the wheelchair.19. The wheelchair of claim 17 or claim 18, further comprising additional input devices for communicating steering information to the chassis via wireless connectivity.20. The wheelchair of any one of claims 17 to 19, further comprising additional parts attachable to the chassis for providing support to arms, legs, body or head of the person 21. The wheelchair of any one of claims 17 to 20, wherein the shell covering is made of fiber glass.
22. A mobile chassis substantially as hereinbefore described with reference to the accompanying drawings.
23. A wheelchair for transporting a person substantially as hereinbefore described with reference to the accompanying drawings